_________________________________

_________________________________

(MARK ONE)

x ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the fiscal year ended June 30, 2015

OR

o TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

FOR THE TRANSITION PERIOD FROM              TO             

Commission file number 001-34717

__________________________

(Exact name of Registrant as Specified in its Charter)

Clarendon House, 2 Church Street

Hamilton HM 11, Bermuda

(Address of Principal Registered

Offices including Zip Code)

(408) 830-9742

(Registrant's Telephone Number, Including Area Code)

__________________________________________

Securities registered pursuant to Section 12(b) of the Act:

Securities registered pursuant to Section 12(g) of the Act:

None

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act.    Yes   o     No   x

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act.    Yes   o     No   x

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months, (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.    Yes   x     No   o

Indicate by check mark whether the registrant has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§ 232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files).    Yes   x    No   o

Indicate by check mark if disclosure of delinquent filers pursuant to Item 405 of Regulation S-K is not contained herein, and will not be contained, to the best of registrant's knowledge, in definitive proxy or information statements incorporated by reference in Part III of this Form 10-K, or any amendment to this Form 10-K.    o

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer or smaller reporting company. See definitions of "large accelerated filer," "accelerated filer" and "smaller reporting company" in Rule 12b-2 of the Exchange Act. (Check one):

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).    Yes   o     No   x

The aggregate market value of the voting shares held by non-affiliates of the registrant as of December 31, 2014 was approximately $196 million based on the closing price of the registrant's common share as reported on the NASDAQ Global Market on December 31, 2014 (the last business day of the registrant's most recently completed second fiscal quarter). The common shares of the registrant held by each executive officer and director and certain affiliated shareholders who beneficially owned 10% or more of the outstanding common stock of the registrant have been excluded in such calculation as such persons and entities may be deemed to be affiliates. This determination of affiliate status is not necessarily a conclusive determination for other purposes.

There were 22,921,346 shares of the registrant's common shares outstanding as of July 31, 2015 .

DOCUMENTS INCORPORATED BY REFERENCE

Portions of the registrant's Proxy Statement for the registrant's 2015 Annual Meeting of Shareholders are incorporated by reference into Part III of this Form 10-K to the extent stated herein. The Definitive Proxy Statement is expected to be filed within 120 days of the registrant's fiscal year ended June 30, 2015 .

Alpha and Omega Semiconductor Limited

Form 10-K

For the Year Ended June 30, 2015

TABLE OF CONTENTS

(This page intentionally left blank.)

PART I

Forward Looking Statements

This Annual Report on Form 10-K and the documents incorporated herein by reference contains forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended, which are subject to the "safe harbor" created by those sections. Forward-looking statements are based on our management's beliefs and assumptions and on information currently available to our management. In some cases, you can identify forward-looking statements by terms such as "may," "will," "should," "could," "intend," "would," "expect," "plan," "anticipate," "believe," "estimate," "project," "predict," "potential" and similar expressions intended to identify forward-looking statements. These statements involve known and unknown risks, uncertainties and other factors, which may cause our actual results, performance, time frames or achievements to be materially different from any future results, performance, time frames or achievements expressed or implied by the forward-looking statements. We discuss many of these risks, uncertainties and other factors in this Annual Report on Form 10-K in greater detail in Item 1A."Risk Factors." Given these risks, uncertainties and other factors, you should not place undue reliance on these forward-looking statements. Also, these forward-looking statements represent our estimates and assumptions only as of the date of this filing. You should read this Annual Report on Form 10-K in its entirety and with the understanding that our actual future results may be materially different from what we expect. We hereby qualify our forward-looking statements by these cautionary statements. Except as required by law, we assume no obligation to update these forward-looking statements publicly, or to update the reasons actual results could differ materially from those anticipated in these forward-looking statements, even if new information becomes available in the future.

Overview

We are a designer, developer and global supplier of a broad portfolio of power semiconductors. Our portfolio of power semiconductors includes approximately 1,500 products, and has grown significantly with the introduction of over 100 new products during each of the fiscal years ended June 30, 2015 , 2014 and 2013 . Our teams of scientists and engineers have developed extensive intellectual properties and technical knowledge that encompass major aspects of power semiconductors, which we believe enables us to introduce and develop innovative products to address the increasingly complex power requirements of advanced electronics. We have an extensive patent portfolio that consists of 517 patents and 193 patent applications in the United States as of June 30, 2015 . We differentiate ourselves by integrating our expertise in technology, design, manufacturing capability and advanced packaging to optimize product performance and cost. Our portfolio of products targets high-volume applications, including personal computers, flat panel TVs, LED lighting, smart phones, battery packs, consumer and industrial motor controls and power supplies for TVs, computers, servers and telecommunications equipment.

During the fiscal year ended June 30, 2015, we continued our diversification program by developing new silicon and packaging platforms to expand our serviceable available market, or SAM and offer higher performance products. Our metal-oxide-semiconductor field-effect transistors, or MOSFET, portfolio expanded significantly across a full range of voltage applications. We also developed new technologies and products designed to penetrate into markets beyond our MOSFET computing base, including the consumer, communications and industrial markets as well as power IC for the next generation computing applications.

Our business model leverages global resources, including research and development and manufacturing in the United States and Asia. Our sales and technical support teams are localized in several growing markets primarily in Asia. We operate a 200mm wafer fabrication facility located in Hillsboro, Oregon, or the Oregon fab, which enables us to accelerate proprietary technology development, new product introduction and improve our financial performance. To meet the market demand for the more mature high volume products, we also utilize the wafer manufacturing capacity of selected third party foundries. For assembly and test, we primarily rely upon our in-house facilities in China. In addition, we utilize subcontracting partners for industry standard packages. We believe our in-house packaging and testing capability provides us with a competitive advantage in proprietary packaging technology, product quality, costs and sales cycle time.

We were incorporated in Bermuda on September 27, 2000 as an exempted limited liability company. The address of our registered office is Clarendon House, 2 Church Street, Hamilton HM 11, Bermuda. Our agent for service of process in the U.S. for the purpose of our securities filings is our Chief Executive Officer, Mike F. Chang, c/o Alpha and Omega Semiconductor Incorporated, 475 Oakmead Parkway, Sunnyvale, CA 94085. Telephone number of our agent is (408) 830-9742.

We have incorporated various wholly-owned subsidiaries in different jurisdictions. Please refer to Exhibit 21.1 for a complete list of our subsidiaries.

Our industry

Semiconductors are electronic devices that perform a variety of functions, such as converting or controlling signals, processing data and delivering or managing power. With advances in semiconductor technology, the functionality and performance of semiconductors have generally increased over time, while size and cost have generally decreased. These advances have led to a proliferation of more complex semiconductors being used in a wide variety of consumer, computing, communications and industrial markets and have contributed to the growth of the semiconductor industry.

Analog semiconductors

The semiconductor industry is segmented into analog and digital. Analog semiconductors process light, sound, motion, radio waves and electrical currents and voltages. In contrast, digital semiconductors process binary signals represented by a sequence of ones and zeros.

As a result of these fundamental differences, the analog semiconductor industry is distinct from the digital semiconductor industry in terms of the complexity of design and the length of product cycle. Improper interactions between analog circuit elements can potentially render an electronic system inoperable. Experienced engineers engaged in the design process are necessary because computer-aided design cannot fully model the behavior of analog circuitry. Therefore, experienced analog engineers with requisite knowledge are in great demand but short supply worldwide. In addition, analog semiconductors tend to have a longer product life cycle because original design manufacturers, or ODMs and original equipment manufacturers, or OEMs typically design the analog portions of a system to span multiple generations of their products. Once designed into an application, the analog portion is rarely modified because even a slight change to the analog portion can cause unexpected interactions with other components, resulting in system instability.

Power semiconductors

Power semiconductors are a subset of the analog semiconductor sector with their own set of characteristics unique to power architecture and function. Power semiconductors transfer, manage and switch electricity to deliver the appropriate amount of voltage or current to a broad range of electronic systems and also protect electronic systems from damage resulting from excessive or inadvertent electrical charges.

Power semiconductors can be either discrete devices, which typically comprise only a few transistors or diodes, or ICs, which incorporate a greater number of transistors.  The function of power discretes is power delivery by switching, transferring or converting electricity.  Power transistors comprise the largest segment of the power discretes market. Power ICs, sometimes referred to as power management ICs, perform power delivery and power management functions, such as controlling and regulating voltage and current and controlling power discretes.

The growth of the power semiconductor market in recent years has several key drivers. The proliferation of computer and consumer electronics, such as desktop computers, notebooks, tablets, smart phones, flat panel displays and portable media players created the need for sophisticated power management to improve power efficiency and extend battery life. The evolution of these products is characterized by increased functionality, thinner or smaller form factors and decreasing prices. Our Power IC and low voltage (5V-40V) MOSFET products address this market. In the area of AC-DC power supplies for electronic equipment, data centers and servers, the market is characterized by a continuous demand for energy conservation through higher efficiency, which is driving the need for our medium voltage (40V-400V) and high voltage (500V-1000V) MOSFET products. The increased application of power semiconductors to control motors in white goods and industrial applications, is driving demand for Insulated Gate Bipolar Transistors, or IGBTs. IGBTs are also being used in renewable energy and automotive applications.

The evolution toward smaller form factors and complex power requirements in the low voltage areas has driven further integration in power semiconductors, resulting in power ICs that incorporate the functionalities of both power management and power delivery functions in a single device. Power ICs can be implemented by incorporating all necessary power functions either on one piece of silicon or multiple silicon chips encapsulated into a single device. Additionally, the advancement in semiconductor packaging technology enables increased power density and shrinking form factors.

Power semiconductor suppliers develop and manufacture their products using various approaches which tend to fall across a wide spectrum of balancing cost savings with proprietary technology advantages. At one end of the spectrum are

integrated design manufacturers, or IDMs, which own and operate the equipment used in the manufacturing process and design and manufacture products at their in-house facilities. IDMs exercise full control over the implementation of process technologies and have maximum flexibility in setting priorities for their production and delivery schedules. At the other end of the spectrum are completely-outsourced fabless semiconductor companies, which rely entirely on off-the-shelf technologies and processes provided by their manufacturing partners. These companies seek to reduce or eliminate fixed costs by outsourcing both product manufacturing and development of process technologies to third parties. The "fab-lite" model seeks to achieve the best balance between technological advancement and cost effectiveness by using a dedicated in-house technology laboratory to drive rapid new product developments, while utilizing third-party foundry capacity for mature products. This is particularly important in the development of power semiconductor products due to the unique nature of their technology. While digital technologies are highly standardized in leading foundries, power semiconductor technologies tend to be more unique as they seek to accommodate a wider range of voltage applications. Accordingly, third-party foundries, which are primarily setup for digital technologies, can be limited when it comes to the development of new power semiconductor technologies.

Our strategies

Our strategy is to advance our position as a designer, developer and global supplier of a broad portfolio of power semiconductors utilizing a fab-lite business model.

The fab-lite business model allows us to accelerate the development of our proprietary technology at our Oregon fab, bring new products to market faster, and improve our financial performance in the long run. We also expect this "fab-lite" model to provide quicker response to our customer demands, enhance relationships with strategic customers, provide flexibility in capacity management and geographic diversification of our wafer supply chain. This approach allows us to retain a higher level of control over the development and application of our proprietary process technology, thereby reducing certain operational risks and costs associated with utilizing third-party foundries.

In recent years, the global PC market has experienced a significant decline primarily due to continued growth of demand in tablets and smart phones. Because a significant portion of our revenue was dependent upon the PC market, such decline resulted in lower utilization of our Oregon fab and packaging facilities in China, which negatively impacted our financial performance. In response to this trend, we have been and are continuing to execute our strategies to diversify our product portfolio, penetrate into other market segments, including the consumer, communications and industrial markets, improve gross margin and profit by implementing cost control measures. We are making progress in reducing our reliance on the computing market, we are also committed to continue to support our computing business and capitalize on the opportunity with a more focused and competitive PC product strategy.

We plan to further expand the breadth of our product portfolio to increase our total bill-of-materials within an electronic system and to address the power requirements of additional electronic systems. Our product portfolio currently consists of approximately 1,500 products and we have introduced over 100 new products in this past fiscal year. We will continue to leverage our expertise to further increase our product lines, including higher performance power ICs, IGBTs and high and medium voltage MOSFETs, in order to expand our addressable market and improve our margin profile. We also believe that our expanding product offerings will allow us to penetrate new end-market applications and provide us with an important competitive advantage. OEMs and ODMs generally prefer to limit their supplier base to a smaller set of vendors capable of providing a comprehensive menu of products across multiple electronic platforms.

Leverage our power semiconductor expertise to drive new technology platforms

We believe that the ever-increasing demand for power efficiency in power semiconductors requires expertise in and a deep understanding of the interrelationship among device physics, process technologies, design and packaging. We also believe that engineers with experience and understanding of these multiple disciplines are in great demand but short supply. Within this context, we believe that we are well positioned to be a leader in providing total power management solutions due to our extensive pool of experienced scientists and engineers and our strong IP portfolio. Accordingly, we intend to leverage our expertise to increase the number of power discrete technology platforms and power IC designs to expand our product offerings and deliver complete power solutions for our targeted applications.

Increase direct relationships and product penetration with OEM and ODM customers

We have developed direct relationships with key OEMs who are responsible for branding, designing and marketing a broad array of electronic products, as well as ODMs who have traditionally been responsible for manufacturing these products. While OEMs typically focus their design efforts on their flagship products, as the industry has evolved, ODMs are increasingly responsible for designing portions, or entire systems, of the products they manufacture for the OEMs. In addition, several

ODMs are beginning to design, manufacture and brand their own proprietary products which they sell directly to consumers. We intend to strengthen our existing relationships and form new ones with both OEMs and ODMs by aligning our product development efforts with their product requirements, increasing the number of our products used within their systems, and leveraging our relationships to penetrate their other products. In addition, we are refocusing our research and development efforts to respond more directly to the market demand by designing and developing new products based on feedback from our customers, which also allows us to reduce time-to-market and sales cycles.

Leverage global business model for cost-effective growth

We intend to continue to leverage our global resources and regional strengths. We will continue to deploy marketing, sales and technical support teams in close proximity to our end customers. We plan to further expand and align our technical marketing and application support teams along with our sales team to better understand and address the needs of our end customers and their end-market applications, in particular for those with the new technology platforms developed in this past year and in the future. This will assist us in identifying and defining new technology trends and products and to help us gain additional design wins.

Our products

To serve the large and diverse analog market for power semiconductors, we have created a broad product portfolio consisting of two major categories: power discretes and power ICs.

Our power discretes products consist primarily of low, medium and high voltage power MOSFETs. Our low-voltage MOSFET series is based on our proprietary technology, which offers increased efficiency and performance by reducing on-resistance and switching losses. We also introduced the XSFET packaging technology platform to provide a high thermal performance solution for advanced computing and high efficiency telecommunications and industrial applications. Our mid-voltage MOSFET portfolio offers high efficiency solutions for advanced telecommunications and industrial power supply applications. Our high-voltage portfolio includes our proprietary insulated-gate bipolar transistor ("IGBT") technology, which we developed highly robust and easy-to-use solutions designed for industrial motor control and white goods applications.

Our power ICs deliver power as well as control and regulate the power management variables, such as the flow of current and level of voltage. We continued to expand our EZBuck power IC family with products that feature lower on-resistance, small footprint and thermally enhanced packages. While we derive the majority of our revenue from the sales of power discretes products, sales of power ICs have been gaining traction during the past years.

The following table lists our product families and the principal end uses of our products:

Power discrete products

Power discretes are used across a wide voltage and current spectrum, requiring them to operate efficiently and reliably under harsh conditions. Due to this wide applicability across diverse end-market applications, we market general purpose MOSFETs that are used in multiple applications as well as MOSFETs targeted for specific applications.

Our current power discrete product line includes industry standard trench MOSFETs, SRFETs, XSFET, electrostatic discharge, protected MOSFETs, high and mid-voltage MOSFETs and IGBTs.

Power IC products

In addition to the traditional monolithic or single chip design, we employ a multi-chip approach for the majority of our power ICs. This multi-chip technique leverages our proprietary MOSFET and advanced packaging technologies to offer integrated solutions to our customers. This allows us to update a product by interchanging only the MOSFETs without changing the power management IC, thereby reducing the time required for new product introduction. We believe that our power IC products improve our competitive position by enabling us to provide higher power density solutions to our end customers than our competitors.

The incorporation of both power delivery and power management functions tends to make power ICs more application specific because these two functions have to be properly matched to a particular end product. We have local technical marketing and applications engineers who closely collaborate with our end customers to help ensure that power IC specifications are properly defined at the beginning of the design stage.

New Product Introduction

We introduced several new products based on our proprietary technology platform and continue to expand the product family by introducing new solutions to computing and LED back lighting for LCD-TV during past fiscal year. During the three months ended June 30, 2015, we introduced the new 1200V/1350V E-series IGBTs optimized for soft-switching applications which delivers high performance by lower switching loss. We also expanded our IGBT product portfolio with the release of the 650V M-Series. This platform optimizes for superior performance with higher robustness in addition to fast and soft turn-off switching in motor drives. During the three months ended March 31, 2015, we released two new MOSFETs optimized for battery protection applications which are the latest additions to our state-of-the-art AlphaDFN™ package portfolio. These

devices are specifically targeting one and two cells portable battery pack applications. During the three months ended December 31, 2014, we launched new generation EZBuck(TM) regulator in a thermally enhanced package. The device offers a low on-resistance power stage in a thermally enhanced 3mm x 3mm DFN package, allowing cooler power conversion for a variety of consumer electronics applications such as LCD TVs, set-top-boxes, as well as DVD players and recorders. We also introduced new 40V 0.99mOhm MOSFET in a DFN5x6 package during the three months ended December 31, 2014. The device is to address a wide range of applications including primary-side and secondary-side switching in telecom and industrial DC/DC converters, secondary-side synchronous rectification in DC/DC and AC/DC converters, as well as POL modules for telecom systems. During the three months ended September 30, 2014, we rolled out new family of 25-V and 30-V high performance MOSFETs in compact 3 x 3mm DFN packages. These devices are ideally suited for a variety of DC/DC step-down conversion solutions for personal computing, gaming, servers, and telecom/datacom applications. We also enhanced the EZPower(TM) smart load switch portfolio with rapid turn-off fault protection and current monitoring. The device has an operating input voltage range from 5-V to 16-V and is capable of supplying up to 6A of continuous current. A low on-resistance of 23mΩ in a thermally enhanced 3mm x 3mm DFN package makes the AOZ1363 optimal for space-constrained applications that require circuit protection such as the latest notebook PCs, hot swap supplies and micro servers.

Distributors and customers

We have developed direct relationships with key OEMs, including Dell Inc., Hewlett-Packard Company, LG Electronics, Inc. and Samsung Group, most of which we serve through our distributors and ODMs. We sell to Samsung Group directly which accounted for 11.7% , 11.6% and 13.0% of our revenue for the fiscal years ended June 30, 2015 , 2014 and 2013 , respectively. In addition, based on our historical design win activities, our power semiconductors are also incorporated into products sold to certain OEMs.

Through our distributors, we provide products to ODMs who traditionally are contract manufacturers for OEMs. As the industry has evolved, ODMs are increasingly responsible for designing portions, or entire systems, of the products they manufacture for the OEMs. In addition, several ODMs are beginning to design, manufacture and brand their own proprietary products, which they sell directly to consumers. Our ODM customers include Compal Electronics, Inc., Foxconn, Quanta Computer Incorporated, Pegatron,Wistron Corporation and AOC International.

In order to take advantage of the expertise of end-customer fulfillment logistics and shorter payment cycles, we sell most of our products to distributors. In general, under the agreements with our distributors, they have limited rights to return unsold merchandise, subject to time and volume limitations. As of June 30, 2015 and June 30, 2014 , the two largest distributors of our products were WPG Holdings Limited, or WPG, and Promate Electronic Co. Ltd., or Promate. Sales to WPG and Promate accounted for 36.1% and 25.4% of our revenue, respectively, for the fiscal year ended June 30, 2015 , 43.1% and 21.6% of our revenue, respectively, for the fiscal year ended June 30, 2014 , and 41.6% and 24.4% of our revenue, respectively, for fiscal year ended June 30, 2013 , respectively.

Sales and marketing

Our marketing division is responsible for identifying high growth markets and applications where we believe our technology can be effectively deployed. We believe that the technical background of our marketing team, including application engineers, helps us better define new products and identify potential end customers and geographic and product market opportunities. For example, as part of our market diversification strategy, we have deployed and plan to recruit more for our new market segments, field application engineers, or FAEs, who provide real-time and on-the-ground responses to our end customer needs, work with our end customers to understand their requirements, resolve technical problems, strive to anticipate future customer needs and facilitate the design-in of our products into the end products of our customers. We believe this strategy increases our share of revenue opportunities within the applications we currently serve, as well as in new end-market applications.

Our sales team consisted of sales persons, field application engineers, customer service representatives and customer quality engineers who are responsible for key accounts. We strategically position our team near our end customers through our offices in Taipei, Hong Kong, Shenzhen, Shanghai, Tokyo, Seoul and Sunnyvale, California, complemented by our applications centers in Sunnyvale and Shanghai. In addition, our distributors and sales representatives assist us in our sales and marketing efforts by identifying potential customers, sourcing additional demand and promoting our products, in which case we may pay a sales commission to these distributors.

Our sales cycle varies depending on the types of products and can range from six to eighteen months.  In general, our traditional power discrete products in the PC and TV applications are moving more rapidly through the design and marketing processes, therefore they generally have shorter sales cycle.  In contrast, our newer Power IC and IGBT products, mostly in the

power supply, home appliance and industrial applications, require a more extended design and marketing timeline and thus have longer sales cycle.  Typically, our sales cycle for all products comprises of the following steps:

Competition

The power semiconductor industry is characterized by fragmentation with many competitors. We compete with different power semiconductor suppliers, depending on the type of product lines and geographical area. Our key competitors in power discretes and power ICs are primarily headquartered in the United States, Japan, Europe and Taiwan. Our major competitors in power discretes include Fairchild Semiconductor International, Inc., Infineon Technologies AG, MagnaChip Semiconductor Corporation, ON Semiconductor Corp., STMicroelectronics N.V., Toshiba Corporation, Diodes Incorporated and Vishay Intertechnology, Inc. Our major competitors for our power ICs include Global Mixed-mode Technology Inc., Monolithic Power Systems, Inc., Richtek Technology Corp., Semtech Corporation and Texas Instruments Inc.

Our ability to compete depends on a number of factors, including:

Some of our competitors have longer operating histories, more brand recognition, and significantly greater financial, technical, research and development, sales and marketing, manufacturing and other resources. However, we believe that we can compete effectively through our integrated and innovative technology platform and design capabilities, including our multi-chip approach to power IC products, strategic global business model, expanding portfolio of products, diversified and broad customer base, and excellent on-the-ground support and quick time to market for our products.

Seasonality

As we provide power semiconductors used in consumer electronic products, our business is subject to seasonality. Our sales seasonality is affected by a number of factors, including global and regional economic conditions as well as the PC market conditions, revenue generated from new products, changes in distributor ordering patterns in response to channel inventory adjustments and end customer demand for our products and fluctuations in consumer purchase patterns prior to major holiday seasons. In recent periods, broad fluctuations in the semiconductor markets and the global and regional economic conditions, in particular the decline of the PC market conditions, have had a more significant impact on our results of operations than seasonality, and have made it difficult to assess the impact of seasonal factors on our business.

Backlog

Our sales are made primarily pursuant to standard purchase orders from distributors and direct customers. The amount of backlog to be shipped during any period depends on various factors, and all orders are subject to cancellation or modification,

usually with no penalty to customers. The quantities actually purchased by customers, as well as shipment schedules, are frequently revised to reflect changes in both the customers' requirements and in manufacturing availability. Therefore, our backlog at any point in time is not a reliable indicator of our future revenue.

Research and development

Because we view technology as a competitive advantage, we invest significant time and capital into research and development to address the technology intensive needs of our end customers. Our research and development expenditures for the fiscal years of 2015 , 2014 and 2013 were $27.1 million , $24.4 million and $27.8 million , respectively. Our research and development expenditures primarily consist of staff compensation, prototypes, engineering materials, simulation and design tools and test and analyzer equipment. Our new product development efforts continue to focus on developing products with higher speed, higher efficiency and reliability, higher power density, greater performance and lower costs. We have research and development teams in Silicon Valley (Sunnyvale, California), Oregon, Taipei, Taiwan, and Shanghai, China. We believe that these diverse research and development teams enables us to develop leading edge technology platforms and new products. Our areas of research and development focus include:

Packaging technologies : Consumer demand for smaller and more compact electronic devices with higher power density is driving the need for advanced packaging technology. Our group of dedicated packaging engineers focuses on smaller form factor, higher power output with efficient heat dissipation and cost-effectiveness. We have invested significant resources to develop and enhance our proprietary packaging technologies, including the establishment of our in-house packaging and testing facilities. We believe that our efforts to develop innovative packaging technologies will continue to provide new and cost-effective solutions with higher power density to our customers. During the fiscal year ended June 30, 2015, we continued our diversification program by developing new silicon and packaging platforms to expand our SAM and offer higher performanced products.

Process technology and device physics: We focus on specialized process technology in the manufacturing of our products, including vertical DMOS, Shielded Gate Trench, Trench field stop IGBTs, charge-balance high voltage MOSFETs, Schottky Diode and BCDMOS processes. Our process engineers work closely with our design team to deploy and implement our proprietary manufacturing processes at our Oregon fab as well as the third-party foundries that fabricate our wafers. To improve our process technology, we continue to develop and enhance our expertise in device physics in order to better understand the physical characteristics of materials and the interactions among these materials during the manufacturing process.

New products and new technology platforms: We also invest significantly in the development of new technology platforms and introduction of new products. Because power management affects all electronic systems, we believe that developing a wide portfolio of products enables us to target new applications in addition to expanding our share of power management needs served within existing applications.

As a technology company, we will continue our significant investment in research and development in our low voltage and high voltage power discretes and power ICs by developing new technology platforms and new products that allow for better product performance, more efficient packages and higher levels of integration.

Operations

The manufacture of our products is divided into two major steps: wafer fabrication and packaging and testing.

Wafer fabrication

Our Oregon fab allows us to accelerate the development of our technology and products, as well as to provide better services to our customers. We allocate our wafer production between our in-house facility and third-party foundries, although in the past three years, we have gradually reduced our reliance on third-party foundries following the acquisition and integration of the Oregon fab. Currently our main third-party foundry is Shanghai Hua Hong Grace Electronic Company Limited, ("HHGrace"), or formerly HHNEC, located in Shanghai. HHGrace has been manufacturing wafers for us since 2002. HHGrace manufactured 25.0% , 28.6% and 37.7% of the wafers used in our products for the fiscal years ended June 30, 2015 , 2014 and 2013 , respectively.

Packaging and testing

Completed wafers from the foundries are sent to our in-house packaging and testing facilities or to our subcontractors, where the wafers are cut into individual die, soldered to lead frames, wired to terminals and then encapsulated in protective packaging. After packaging, all devices are tested in accordance with our specifications and substandard or defective devices

are rejected. We have established quality assurance procedures that are intended to control quality throughout the manufacturing process, including qualifying new parts for production at each packaging facility, conducting root cause analysis, testing for lots with process defects and implementing containment and preventive actions. The final tested products are then shipped to our distributors or customers.

Our in-house packaging and testing facilities are located in Shanghai, China which handle most of our packaging and testing requirements for our products, and we continuously increase outsourcing portion of our packaging and testing requirements to other contract manufacturers to minimize the effect of market fluctuation. Our facilities have the combined capacity to package and test over 500 million parts per month and have available floor space for new package introductions. We believe our ability to package and test our products internally represents a strategic advantage as it protects our proprietary packaging technology, increases the rate of new package introductions, reduces operating expenses and ultimately improves our profit margins.

Quality assurance

Our quality assurance practices aim to consistently provide our end customers with products that are reliable, durable and free of defects. We strive to do so through continuous improvement in our product design and manufacturing and close collaboration with our manufacturing partners. Our manufacturing operations in China and our manufacturing facility in Oregon are certified to the ISO9001 and ISO/TS16949:2009. These Quality Management System certifications are in recognition of our quality assurance standards. Both ISO9001and ISO/TS16949:2009 are sets of criteria and procedures established by International Organization of Standardization for developing a fundamental quality management system and focusing on continuous improvement, defect prevention and the reduction of variation and waste. Our products are also in compliance with Restrictions on the use of Hazardous Substances, or RoHS 2.0.

We maintain a supplier management and process engineering team in Shanghai that works with our third-party foundries and packaging and testing subcontractors to monitor the quality of our products, which is designed to ensure that manufacturing of our products, is in strict compliance with our process control, monitoring procedures and product requirements. We also conduct periodic reviews and annual audits to ensure supplier performance. For example, we examine the results of statistical process control systems, implement preventive maintenance, verify the status of quality improvement projects and review delivery time metrics. In addition, we rate and rank each of our suppliers every quarter based on factors such as their quality and performance. Our facility in Oregon integrates manufacturing process controls through our manufacturing execution system coupled with wafer process controls that include monitoring procedures, preventative maintenance, statistical process control, and testing to ensure that finished wafers delivered will meet and exceed quality and reliability requirements. All materials used to manufacture wafers are controlled through a strict qualification process.

Our manufacturing processes use many raw materials, including silicon wafers, gold, copper, molding compound, petroleum and plastic materials and various chemicals and gases. We obtain our raw materials and supplies from a large number of sources. Although supplies for the raw materials used by us are currently adequate, shortages could occur in various essential materials due to interruption of supply or increased demand in the industry.

Intellectual property rights

Intellectual property is a critical component of our business strategy, and we intend to continue to invest in the growth, maintenance and protection of our intellectual property portfolio. We own significant intellectual property in many aspects of power semiconductor technology, including device physics and structure, wafer processes, circuit designs, packaging, modules and subassemblies. We have also entered into intellectual property licensing agreements with other companies, including Fairchild Semiconductor International, Inc. and Giant Semiconductor Corporation, to use selected third-party technology for the development of our products, although we do not believe our business is dependent to any significant degree on any individual third-party license agreement.

While we focus our patent efforts in the United States, we file corresponding foreign patent applications in other jurisdictions, such as China and Taiwan, when filing is justified by cost and strategic importance. The patents are increasingly important to remain competitive in our industry, and a strong patent portfolio will facilitate the entry of our products into new markets. As of June 30, 2015 , we had 517 patents issued in the United States, of which 39 were acquired, 2 were licensed and 476 were based on our research and development efforts, and these patents are set to expire between 2015 and 2033. We also had a total of 457 foreign patents, including 237 Chinese patents, 202 Taiwanese patents, 10 Korean patents, 4 Hong Kong patents and 4 Japanese patents as of June 30, 2015 . Substantially all of our foreign patents were based on our research and development efforts. These foreign patents expire in the years between 2015 and 2032. In addition, as of June 30, 2015 , we

had a total of 583 patent applications, of which 193 patents were pending in the United States, 231 patents were pending in China, 147 patents were pending in Taiwan and 12 patents were pending in other countries.

As our technologies are deployed in new applications and as we diversify our product portfolio based on new technology platforms, we may be subject to new potential infringement claims. Patent litigation, if and when instituted against us, could result in substantial costs and a diversion of our management's attention and resources. However, we are committed to vigorously defending and protecting our investment in our intellectual property. Therefore, the strength of our intellectual property program, including the breadth and depth of our portfolio, will be critical to our success in the new markets we intend to pursue.

In addition to patent protection, we also rely on a combination of trademark, copyright (including mask work protection), trade secret laws, contractual provisions and similar laws in other jurisdictions. We also enter into confidentiality and invention assignment agreements with our employees, consultants, suppliers, distributors and customers and seek to control access to, and distribution of, our proprietary information.

Environmental matters

The semiconductor production process, including the semiconductor wafer manufacturing and packaging process, generates air emissions, liquid wastes, waste water and other industrial wastes. We have installed various types of pollution control equipment for the treatment of air emissions and liquid waste and equipment for recycling and treatment of water in our packaging and testing facilities in China and wafer manufacturing facility in Oregon, USA. Waste generated at our manufacturing facilities, including but not limited to acid waste, alkaline waste, flammable waste, toxic waste, oxide waste and self-igniting waste, is collected and sorted for proper disposal. Our operations in China are subject to regulation and periodic monitoring by China's State Environmental Protection Bureau, as well as local environmental protection authorities, including those under the Shanghai Municipal Government, which may in some cases establish stricter standards than those imposed by the State Environmental Protection Bureau. Our operation in Oregon is subject to Oregon Department of Environmental Regulations, Federal Environmental Protection Agency laws and regulations, and local jurisdictional regulations. We believe that we have been in material compliance with applicable environmental regulations and standards and have not had a material or adverse effect on our results of operations from complying with these regulations.

We have implemented an ISO 14001 environmental management system in our manufacturing facilities in China and Oregon. We also require our subcontractors, including foundries and assembly houses, to meet ISO14001 standards. We believe that we have adopted pollution control measures for the effective maintenance of environmental protection standards consistent with the requirements applicable to the semiconductor industry in China and the U.S..

Our products sold in Europe are subject to RoHS in Electrical and Electronic Equipment, which requires that the products do not contain more than agreed levels of lead, cadmium, mercury, hexavalent chromium, polybrominated biphenyl and polybrominated diphenyl ether flame retardants. Our manufacturing facilities in China also obtained QC080000 certification, which is an IECQ Certificate of Conformity Hazardous Substance Process Management for European Directive 2002/95/EC requirements and a Certificate of Green Partner for Sony Green Partner Program. We avoid using these restricted materials to the extent possible when we design our products.

We are also subject to SEC rules that require diligence, disclosure and reporting on whether certain minerals and metals, known as conflict minerals, used in our products originate from the Democratic Republic of Congo and adjoining countries. As of June 30, 2015 and 2014, we are in compliance with the related conflict minerals rule.

Employees

As of June 30, 2015 , we had approximately 2,780 employees, of which approximately 380 were located in the United States, 2,300 were located in China, and 100 were located in other parts of Asia. Of the total employees, approximately 2,360 were in operations and manufacturing, 150 were in research and development, 150 were in sales and marketing and 120 were in general and administrative. None of our employees are represented by a collective bargaining agreement and we have never experienced a work stoppage due to labor issues. We consider our relationships with our employees to be good.

Executive Officers

The following table lists the names, ages and positions of our executive officers as of July 31, 2015 . There are no family relationships between any executive officer.

Mike F. Chang, Ph.D ., is the founder of our company and has served as our Chairman of the Board and Chief Executive Officer since the incorporation of our company. Dr. Chang has extensive experience in both technology development and business operations in the power semiconductor industry. Prior to establishing our company, Dr. Chang served as the Executive Vice President at Siliconix Incorporated, a subsidiary of Vishay Intertechnology Inc., a global manufacturer and supplier of discrete and other power semiconductors, or Siliconix, from 1998 to 2000. Dr. Chang also held various management positions at Siliconix from 1987 to 1998. Earlier in his career, Dr. Chang focused on product research and development in various management positions at General Electric Company from 1974 to 1987. Dr. Chang received his B.S. in electrical engineering from National Cheng Kung University, Taiwan, and M.S. and Ph.D. in electrical engineering from the University of Missouri.

Yueh-Se Ho, Ph.D ., is a co-founder of our company and has served as our Chief Operating Officer since January 2006 and our director since March 2006. Dr. Ho has held various operational management positions in our company since our inception, including the Vice President of Worldwide Operations from 2003 to 2006 and the Vice President of Back End Operations from 2000 to 2003. Prior to co-founding our company, Dr. Ho served as the Director of Packaging Development and Foundry Transfer at Siliconix from 1998 to 2000. Dr. Ho received his B.S. in chemistry from Tamkang University, Taiwan, and Ph.D. in chemistry from the University of Pittsburgh.

Yifan Liang is currently serving as our Chief Financial Officer since August 2014 and Corporate Secretary since November 2013. Mr. Liang was previously our Interim Chief Financial Officer from November 2013 to August 2014, our Chief Accounting Officer since October 2006, and our Assistant Corporate Secretary from November 2009 to November 2013. Mr. Liang joined our company in August 2004 as our Corporate Controller. Prior to joining us, Mr. Liang held various positions at PricewaterhouseCoopers LLP, or PwC, from 1995 to 2004, including Audit Manager in PwC's San Jose office. Mr. Liang received his B.S. in management information system from the People's University of China and M.A. in finance and accounting from the University of Alabama.

Available Information

Our filing documents and information with the Securities and Exchange Commission (the "SEC") are available free of charge electronically through our Internet website, www.aosmd.com. as soon as reasonably practicable after we electronically file such material with, or furnish it to, the SEC. Additionally, these filings may be obtained by visiting the Public Reference Room of the SEC at 100 F Street, NE, Washington, DC 20549 or by calling the SEC at 1-800-SEC-0330, by sending an electronic message to the SEC at publicinfo@sec.gov. In addition, the SEC maintains a website (www.sec.gov) that contains reports, proxy statements, and other information that we file electronically.

Risks Related to Our Business

The decline of personal computing ("PC") markets may have a material adverse effect on our results of operations.

A significant amount of our revenue is derived from sales of products in the PC markets such as notebooks, motherboards and notebook battery packs.  Our revenue from the PC markets accounted for approximately 47.1%, 45.2% and 50.0% of our total revenue for the years ended 2015 , 2014 and 2013 , respectively. The increasing popularity of smaller, mobile computing devices such as tablets and smartphones with touch interfaces is rapidly changing the PC markets both in the United States and abroad.  Recently, we experienced a significant reduction in the demand for our products due to the declining PC markets, which have negatively impacted our revenue, profitability and gross margin. The decline of the PC markets also adversely affected our ability to adjust inventory levels in response to the lower shipments, which have negatively impacted our gross margins. During the quarter ended March 31, 2013, we recorded a non-cash, non-recurring inventory valuation charge of $5.7 million primarily related to excess and obsolete inventory consisting of PC-related products that were not compatible with a particular OEM's applications and were deemed not saleable. Moreover, the continuing decline of the PC markets may reduce the capacity utilization of our manufacturing facilities or impair the value of our long-lived assets, including equipment and machinery used for the manufacturing and packaging of our products, which could have a material adverse effect on our results of operations.

Our diversification into different market segments may not succeed according to our expectations and may expose us to new risks and place significant strains on our management, operational, financial and other resources.

As part of the growth strategy to diversify our product portfolio and in response to the rapid decline of the PC markets, we have been developing new technologies and products designed to penetrate into other markets and applications, including merchant power supplies, flat panel TVs, smart phones, tablets, gaming consoles, lighting, datacom, home appliances and industrial motor controls. However, there is no guarantee that these diversification efforts will be successful. As a new entrant to some of these markets, we may face intense competition from existing and more established providers and encounter other unexpected difficulties, any of which may hinder or delay our efforts to achieve success. In addition, our new products may have long design and sales cycles, therefore if our diversification efforts fail to keep pace with the declining PC markets, we may not be able to alleviate its negative impact on our results of operations.

Our diversification into different market segments may place a significant strain on our management, operational, financial and other resources. To manage this diversification effectively, we will need to take various actions, including:

Our failure to execute any of the above actions successfully or timely may have an adverse effect on our business and financial results.

Our operating results may fluctuate from period to period due to many factors, which may make it difficult to predict our future performance.

Our periodic operating results may fluctuate as a result of a number of factors, many of which are beyond our control. These factors include, among others:

Any one or a combination of the above factors and other risk factors described in this section may cause our operating results to fluctuate from period to period, making it difficult to predict our future performance. Therefore, comparing our operating results on a period-to-period basis may not be meaningful, and you should not rely on our past results as an indication of our future performance.

Our revenue may fluctuate significantly from period to period due to ordering patterns from our distributors and seasonality.

Demand for our products from our end customers fluctuates depending on their sales outlooks and market and economic conditions. Accordingly, our distributors place purchase orders with us based on their forecasts of end customer demand. Because these forecasts may not be accurate, channel inventory held at our distributors may fluctuate significantly due to the difference between the forecasts and actual demand. As a result, distributors adjust their purchase orders placed with us in response to changing channel inventory levels, as well as their assessment of the latest market demand trends. A significant decrease in our distributors' channel inventory in one period may lead to a significant rebuilding of channel inventory in subsequent periods, or vice versa, which may cause our quarterly revenue and operating results to fluctuate significantly.

In addition, because our power semiconductors are used in consumer electronics products, our revenue is subject to seasonality. Our sales seasonality is affected by a number of factors, including global and regional economic conditions as well as the PC market conditions, revenue generated from new products, changes in distributor ordering patterns in response to channel inventory adjustments and end customer demand for our products and fluctuations in consumer purchase patterns prior to major holiday seasons. In recent year, broad fluctuations in the semiconductor markets and the global economic conditions, in particular the decline of the PC market conditions, have had a more significant impact on our results of operations, than seasonality, and have made it difficult to assess the impact of seasonal factors on our business.

If we are unable to introduce or develop new and enhanced products that meet or are compatible with our customer's product requirements in a timely manner, it may harm our business, financial position and operating results.

Our success depends upon our ability to develop and introduce new and enhanced products that meet or are compatible with our customer's specifications, performance standards and other product requirements in a timely manner. The development of new and enhanced products involves highly complex processes, and at times we have experienced delays in the introduction of new products. Successful product development and introduction of new products depends on a number of factors, including the accurate product specification; timely completion of design; achievement of manufacturing yields; timely response to changes in customers' product requirements; quality and cost-effective production; and effective marketing. Since many of our products are designed for specific applications, we must frequently develop new and enhanced products jointly with our customers. In the past, we have encountered product compatibility issues with a major OEM that has negatively impacted our financial results, and although we have resolved fully such issues with the OEM, there is no guarantee that the same compatibility issues will not occur in the future with other OEMS. If we are unable to develop or acquire new products that meet or are compatible with our customer's specification and other product requirements in a timely manner, we may lose revenue or market shares with our customers, which could have a material adverse effect on our business, financial position and operating results.

We may not win sufficient designs, or our design wins may not generate sufficient revenue for us to maintain or expand our business.

We invest significant resources to compete with other power semiconductor companies to obtain winning competitive bids for our products in selection processes, known as "design wins." Our effort to obtain design wins may detract us from or delay the completion of other important development projects, impair our relationships with existing end customers and negatively impact sales of products under development. In addition, we cannot be assured that these efforts would result in a design win, that our product would be incorporated into an end customer's initial product design, or that any such design win would lead to production orders and generate sufficient revenue. Furthermore, even after we have qualified our products with a customer and made sales, subsequent changes to our products, manufacturing processes or suppliers may require a new qualification process, which may result in delay and excess inventory. If we cannot achieve sufficient design wins in the future, or if we fail to generate production orders following design wins, our ability to grow our business and improve our financial results will be harmed.

Our success depends upon the ability of our OEM end customers to successfully sell products incorporating our products.

The consumer end markets, in particular the PC market, in which our products are used are highly competitive. Our OEM end customers may not successfully sell their products for a variety of reasons, including:

Our success depends on the ability of our OEM end customers to sell their products incorporating our products. In addition, we have expanded our business model to include more OEMs in our direct customer base. The failure of our OEM end customers to achieve or maintain commercial success for any reason could harm our business, results of operations, and financial condition and prospects.

The operation of our Oregon fab may subject us to additional risks and the need for additional capital expenditures which may negatively impact our results of operations.

The operation of the Oregon fab requires significant fixed manufacturing cost. In order to manage the capacity of the wafer fabrication facility efficiently, we must perform a forecast of long-term market demand and general economic conditions for our products. Because market conditions may vary significantly and unexpectedly, our forecast may change significantly at any time, and we may not be able to make timely adjustments to our fabrication capacity in response to these changes. During periods of continued decline in market demand, in particular the decline of the PC market, we may not be able to absorb the excess inventory and additional costs associated with operating the facility at higher capacity, which may adversely affect our operating results. Similarly, during periods of unexpected increase in customer demand, we may not be able to ramp up production quickly to meet these demands, which may lead to the loss of significant revenue opportunities. The

manufacturing processes of a fabrication facility are complex and subject to interruptions. We may experience production difficulties, including lower manufacturing yields or products that do not meet our or our customers' specifications, and problems in ramping production and installing new equipment. These difficulties could result in delivery delays, quality problems and lost revenue opportunities. Any significant quality problems could also damage our reputation with our customers and distract us from the development of new and enhanced product which may have a significant negative impact on our financial results.

In addition, semiconductor manufacturing has historically required an upgrading of process technology from time to time to remain competitive, as new and enhanced semiconductor processes are developed which permit smaller, more efficient and more powerful semiconductor devices. Accordingly, we may have to make substantial capital expenditures and install significant production capacity at our in-house fabrication facility to support new technologies and increased production volume, which may cause delay in our ability to deliver new products or negatively impact our results of operations.

Defects and poor performance in our products could result in loss of customers, decreased revenue, unexpected expenses and loss of market share, and we may face warranty and product liability claims arising from defective products.

Our products are complex and must meet stringent quality requirements. Products as complex as ours may contain undetected errors or defects, especially when first introduced or when new versions are released. Errors, defects or poor performance can arise due to design flaws, defects in raw materials or components or manufacturing anomalies, which can affect both the quality and the yield of the product. It can also be potentially dangerous as defective power components, or improper use of our products by customers, may lead to power overloads, which could result in explosion or fire. As our products become more complex, we face higher risk of undetected defects, because our testing protocols may not be able to fully test the products under all possible operating conditions. In the past, we have experienced defects in our products and these products were returned to us and subsequently scrapped or sold at a discount. Any actual or perceived errors, defects or poor performance in our products could result in the replacement or recall of our products, shipment delays, rejection of our products, damage to our reputation, lost revenue, diversion of our engineering personnel from our product development efforts in order to address or remedy any defects and increases in customer service and support costs, all of which could have a material adverse effect on our business and operations.

Furthermore, as our products are typically sold at prices much lower than the cost of the equipment or other devices incorporating our products, any defective, inefficient or poorly performing products, or improper use by customers of power components, may give rise to warranty and product liability claims against us that exceed any revenue or profit we receive from the affected products. Historically, we have received claims from our customers for charges such as their labor and other costs replacing defective parts, their lost profit, and/or penalty. We could incur significant costs and liabilities if we are sued and if damages are awarded against us. There is no guarantee that our insurance policies will be available or adequate to protect against such claims. Costs or payments we may make in connection with warranty and product liability claims or product recalls may adversely affect our financial condition and results of operations.

If we do not forecast demand for our products accurately, we may experience product shortages, delays in product shipment, excess product inventory, or difficulties in planning expenses, which will adversely affect our business and financial condition.

We manufacture our products according to our estimates of customer demand. This process requires us to make multiple forecasts and assumptions relating to the demand of our end customers, channel inventory, and general market conditions. Because we sell most of our products to distributors, who in turn sell to our end customers, we have limited visibility as to end customer demand. Furthermore, we do not have long-term purchase commitments from our distributors or end customers, and our sales are generally made by purchase orders that may be cancelled, changed or deferred without notice to us or penalty. As a result, it is difficult to forecast future customer demand to plan our operations.

The utilization of our manufacturing facilities and the provisions for inventory write-downs are important factors in our profitability. If we overestimate demand for our products, or if purchase orders are canceled or shipments delayed, we may have excess inventory, which may result in adjustments to our production plans. These adjustments to our productions may affect the utilization of our own wafer fabrication and packaging facilities. If we cannot sell certain portion of the excess inventory, it will affect our provisions for inventory write-downs. Our inventory write-down provisions are subject to adjustment based on events that may not be known at the time the provisions are made, and such adjustments could be material and impact our financial results negatively.

If we underestimate demand, we may not have sufficient inventory to meet end-customer demand, and we may lose market share and damage relationships with our distributors and end customers and we may have to forego potential revenue

opportunities. Obtaining additional supply in the face of product shortages may be costly or impossible, particularly in the short term, which could prevent us from fulfilling orders in a timely manner or at all.

In addition, we plan our operating expenses, including research and development expenses, hiring needs and inventory investments, base in part on our estimates of customer demand and future revenue. If customer demand or revenue for a particular period is lower than we expect, we may not be able to proportionately reduce our fixed operating expenses for that period, which would harm our operating results.

We face intense competition and may not be able to compete effectively which could reduce our revenue and market share.

The power semiconductor industry is highly competitive and fragmented. If we do not compete successfully against current or potential competitors, our market share and revenue may decline. Our main competitors are primarily headquartered in the United States, Japan, Taiwan and Europe. Our major competitors for our power discretes include Diodes Incorporated, Fairchild Semiconductor International, Inc., Infineon Technologies AG, MagnaChip Semiconductor Corporation, ON Semiconductor Corporation, STMicroelectronics N.V., Toshiba Corporation and Vishay Intertechnology, Inc. Our major competitors for our power ICs include Global Mixed-mode Technology Inc., Monolithic Power Systems, Inc., Richtek Technology Corp., Semtech Corporation and Texas Instruments Inc. We expect to face competition in the future from our competitors, other manufacturers, designers of semiconductors and start-up semiconductor design companies. Many of our competitors have competitive advantages over us, including:

If we are unable to compete effectively for any of the foregoing or other reasons, our business, results of operations, and financial condition and prospects will be harmed.

We depend partly on third-party semiconductor foundries to manufacture our products and implement our fabrication processes, and any failure to maintain sufficient foundry capacity and control the cost of production could significantly delay our ability to ship our products, damage our relationships with customers, reduce our sales and increase expenses.

The allocation of our wafer production between in-house facility and third-party foundries may fluctuate from time to time. We expect to continue to rely in part on third party foundries to meet our wafer requirements. Although we use several independent foundries, our primary third-party foundry is HHGrace, which manufactured 25.0% , 28.6% and 37.7% of the wafers used in our products for the fiscal years ended June 30, 2015 , 2014 and 2013 , respectively.

We place our purchase orders with foundries based on sales forecasts for our products. If any third-party foundry does not provide competitive pricing or is not able to meet our required capacity for any reason, we may not be able to obtain the required capacity to manufacture our products timely or efficiently. If we cannot maintain sufficient capacity or control pricing with our existing third-party foundries, we may need to increase our own manufacturing capacity, and there is no assurance that we can ramp up the production of the Oregon fab timely to meet the increased demand. If not, we may need to seek alternative foundries, which may not be available on commercially reasonable terms, or at all. In addition, the process for qualifying a new foundry is time consuming, difficult and may not be successful, particularly if we cannot integrate our proprietary process technology with the process used by the new foundry. Using a foundry with which we have no established relationship could expose us to potentially unfavorable pricing, unsatisfactory quality or insufficient capacity allocation.

In addition, even though we have been transferring more new product developments to our Oregon fab, we still rely on third-party foundries significantly to effectively implement certain of our proprietary technology and processes and also

require their cooperation in developing new fabrication processes. Any failure to do so may impair our ability to introduce new products and on time delivery of wafers for our existing products. In order to maintain our profit margins and to meet our customer demand, we need to achieve acceptable production yields and timely delivery of silicon wafers. As is common in the semiconductor industry, we have experienced, and may experience from time to time, difficulties in achieving acceptable production yields and timely delivery from third-party foundry vendors. Minute impurities in a silicon wafer can cause a substantial number of wafers to be rejected or cause numerous die on a wafer to be defective. Low yields often occur during the production of new products, the migration of processes to smaller geometries or the installation and start up of new process technologies.

We face a number of other significant risks associated with outsourcing fabrication, including:

Any of the foregoing risks could delay shipment of our products, result in higher expenses and reduced revenue, damage our relationships with customers and otherwise adversely affect our business and operating results.

Our operation of two in-house packaging and testing facilities are subject to risks that could adversely affect our business and financial results.

We have two in-house packaging and testing facilities located in Shanghai, China that handle most of our packaging and testing requirements. The operation of high-volume packaging and testing facilities and implementation of our advanced packaging technology are complex and demand a high degree of precision and may require modification to improve yields and product performance. We have committed substantial resources to ensure that our packaging and testing facilities operate efficiently and successfully, including the acquisition of equipment and raw materials, and training and management of a large number of technical personnel and employees. Due to the fixed costs associated with operating our own packaging and testing facilities, if we are unable to utilize our in-house facilities at a desirable level of production, our gross margin and results of operations may be adversely affected. For example, a significant decline in our market share or sales orders may negatively impact our factory utilization and reduce our ability to achieve profitability.

In addition, the operation of our packaging and testing facilities is subject to a number of risks, including the following:

Any of the foregoing risks could adversely affect our capacity to package and test our products, which could delay shipment of our products, result in higher expenses, reduce revenue, damage our relationships with customers and otherwise adversely affect our business, results of operations, financial condition and prospects.

Our reliance on distributors to sell a substantial portion of our products subjects us to a number of risks.

We sell a substantial portion of our products to distributors, who in turn sell to our end customers. Our distributors typically offer power semiconductor products from several different companies, including our direct competitors. The distributors assume collection risk and provide logistical services to end customers, including stocking our products. Two distributors, WPG and Promate, collectively accounted for 61.5% , 64.7% and 66.0% of our revenue for the fiscal years ended June 30, 2015 , 2014 and 2013 , respectively. Our agreement with WPG has an one-year term but is automatically renewed for an additional one-year period continuously unless terminated earlier pursuant to the provisions in the agreement. Our agreement with Promate was renewed in July 2015 and will be automatically renewed for each one-year period continuously unless terminated earlier pursuant to the provisions in the agreement. We believe that our success will continue to depend upon these distributors. Our reliance on distributors subjects us to a number of risks, including:

If any significant distributor becomes unable or unwilling to promote and sell our products, or if we are not able to renew our contracts with the distributors on acceptable terms, we may not be able to find a replacement distributor on reasonable terms or at all and our business could be harmed.

We have made and may continue to make strategic acquisitions of other companies, assets or businesses and these acquisitions introduce significant risks and uncertainties, including risks related to integrating the acquired assets or businesses, incurring additional debt, assuming contingent liabilities or diluting our existing shareholders.

In order to position ourselves to take advantage of growth opportunities, we have made, and may continue to make, strategic acquisitions, mergers and alliances that involve significant risks and uncertainties. Successful acquisitions and alliances in the semiconductor industry are difficult to accomplish because they require, among other things, efficient integration and aligning of product offerings and manufacturing operations and coordination of sales and marketing and research and development efforts. The difficulties of integration and alignment may be increased by the necessity of coordinating geographically separated organizations, the complexity of the technologies being integrated and aligned and the necessity of integrating personnel with disparate business backgrounds and combining different corporate cultures.

In addition, we may also issue equity securities to pay for future acquisitions or alliances, which could be dilutive to existing shareholders. We may also incur debt or assume contingent liabilities in connection with acquisitions and alliances, which could impose restrictions on our business operations and harm our operating results.

If we are unable to obtain raw materials in a timely manner or if the price of raw materials increases significantly, production time and product costs could increase, which may adversely affect our business.

Our fabrication and packaging processes depend on raw materials such as silicon wafers, gold, copper, molding compound, petroleum and plastic materials and various chemicals and gases. From time to time, suppliers may extend lead times, limit supplies or increase prices due to capacity constraints or other factors. If the prices of these raw materials rise significantly, we may be unable to pass on the increased cost to our customers. Our results of operations could be adversely affected if we are unable to obtain adequate supplies of raw materials in a timely manner or at reasonable price. In addition, from time to time, we may need to reject raw materials because they do not meet our specifications or the sourcing of such materials do not comply with our conflict mineral policies, resulting in potential delays or declines in output. Furthermore, problems with our raw materials may give rise to compatibility or performance issues in our products, which could lead to an

increase in customer returns or product warranty claims. Errors or defects may arise from raw materials supplied by third parties that are beyond our detection or control, which could lead to additional customer returns or product warranty claims that may adversely affect our business and results of operations.

Our operations may be delayed or interrupted and our business may be adversely affected as a result of our efforts to comply with environmental regulations applicable to our in-house wafer manufacturing, packaging and testing facility.

Our in-house manufacturing operations, including wafer manufacturing, packaging and testing, are subject to a variety of environmental regulations relating to the use, handling, discharge and disposal of toxic or otherwise hazardous materials. See "Item 1. Business - Environmental matters." Compliance with environmental regulations could require us to acquire expensive pollution control equipment or to incur other substantial expenses or investigate and remediate contamination at our current facilities. Any failure, or any claim that we have failed, to comply with these regulations could cause delays in our production and capacity expansion and affect our public image, either of which could harm our business. In addition, any failure to comply with these regulations could subject us to substantial fines or other liabilities, result in the suspension of our operating permit, or require us to terminate or adversely modify our in-house manufacturing operations.

We may not be able to accurately estimate provisions at fiscal period end for price adjustment and stock rotation rights under our agreements with distributors, and our failure to do so may impact our operating results.

We sell a majority of our products to distributors under arrangements allowing price adjustments and returns under stock rotation programs, subject to certain limitations. As a result, we are required to estimate allowances for price adjustments and stock rotation for our products as inventory at distributors at each reporting period end. Our ability to reliably estimate these allowances enables us to recognize revenue upon delivery of goods to distributors instead of upon resale of goods by distributors to end customers.

We estimate the allowance for price adjustment based on factors such as distributor inventory levels, pre-approved future distributor selling prices, distributor margins and demand for our products. Our estimated allowances for price adjustments, which we offset against accounts receivable from distributors, were $19.4 million and $14.6 million at June 30, 2015 and 2014 , respectively.

Our accruals for stock rotation are estimated based on historical returns and individual distributor agreement, and stock rotation rights, which are recorded as accrued liabilities on our consolidated balance sheets, are contractually capped based on the terms of each individual distributor agreement. Our estimated liabilities for stock rotation at June 30, 2015 and 2014 were $1.9 million and $1.6 million, respectively.

Our estimates for these allowances and accruals may be inaccurate. If we subsequently determine that any allowance and accrual based on our estimates is insufficient, we may be required to increase the size of our allowances and accrual in future periods, which would adversely affect our results of operations and financial condition.

We depend on the continuing efforts of our senior management team and other key personnel, and if we lose a member of our senior management or are unable to successfully retain, recruit and train key personnel, our ability to develop and market our products could be harmed.

Our success depends upon the continuing services of members of our senior management team and various engineering and other technical personnel. In particular, our engineers and other sales and technical personnel are critical to our future technological and product innovations. Our industry is characterized by high demand and intense competition for talent and the pool of qualified candidates is limited. We have entered into employment agreements with certain senior executives, but we do not have employment agreements with most of our employees. Many of these employees could leave our company with little or no prior notice and would be free to work for a competitor. If one or more of our senior executives or other key personnel are unable or unwilling to continue in their present positions, we may not be able to replace them easily or at all and other senior management may be required to divert attention from other aspects of our business. In addition, we do not have "key person" life insurance policies covering any member of our management team or other key personnel. The loss of any of these individuals or our inability to attract or retain qualified personnel, including engineers and others, could adversely affect our product introductions, overall business growth prospects, results of operations and financial condition.

If we fail to maintain an effective system of internal control over financial reporting, we may not be able to accurately report our financial results or prevent fraud.

Our management may conclude that our internal control over financial reporting is not effective. Moreover, even if our management concludes that our internal control over financial reporting is effective, our independent registered public

accounting firm may decline to issue an opinion as to the effectiveness of our internal control over financial reporting, or may issue a report that is qualified or adverse. During the course of the initial evaluation of internal control over financial reporting, we or our independent registered public accounting firm may identify control deficiencies that we may not be able to remediate prior to the date of our first assessment of internal control over financial reporting. Our failure to achieve and maintain effective internal control over financial reporting could result in the loss of investor confidence in the reliability of our financial statements or prevent fraud, which in turn could harm our business and negatively impact the trading price of our shares.

Failure to protect our patents and our other proprietary information could harm our business and competitive position.

Our success depends, in part, on our ability to protect our intellectual property. We rely on a combination of patent, copyright (including mask work protection), trademark and trade secret laws, as well as nondisclosure agreements, license agreements and other methods to protect our intellectual property rights, which may not be sufficient to protect our intellectual property. As of June 30, 2015 , we owned 517 issued U.S. patents expiring between 2015 and 2033 and had 193 pending patent applications with the United States Patent and Trademark Office. In addition, we own additional patents and have filed patent applications in several jurisdictions outside of the U.S, including China, Taiwan, Japan and Korea.

Our patents and patent applications may not provide meaningful protection from our competitors, and there is no guarantee that patents will be issued from our patent applications. The status of any patent or patent application involves complex legal and factual determinations and the breadth of a claim is uncertain. In addition, our efforts to protect our intellectual property may not succeed due to difficulties and risks associated with:

We also rely on customary contractual protections with our customers, suppliers, distributors, employees and consultants, and we implement security measures to protect our trade secrets. We cannot assure you that these contractual protections and security measures will not be breached, that we will have adequate remedies for any such breach or that our suppliers, employees, distributors or consultants will not assert rights to intellectual property arising out of such contracts.

In addition, we have a number of third-party patent and intellectual property license agreements, one of which requires us to make ongoing royalty payments. In the future, we may need to obtain additional licenses, renew existing license agreements or otherwise replace existing technology. We are unable to predict whether these license agreements can be obtained or renewed or the technology can be replaced on acceptable terms, or at all.

Intellectual property disputes could result in lengthy and costly arbitration, litigation or licensing expenses or prevent us from selling our products.

As is typical in the semiconductor industry, we or our customers may receive claims of infringement from time to time or otherwise become aware of potentially relevant patents or other intellectual property rights held by other parties that may cover some of our technology, products and services or those of our end customers. The semiconductor industry is characterized by vigorous protection and pursuit of intellectual property rights which has resulted in protracted and expensive arbitration and litigation for many companies. Patent litigation has increased in recent years due to increased assertions made by intellectual property licensing entities or non-practicing entities and increasing competition and overlap of product functionality in our markets.

Any litigation or arbitration regarding patents or other intellectual property could be costly and time consuming and could divert our management and key personnel from our business operations. We have in the past and may from time to time

in the future become involved in litigation that requires our management to commit significant resources and time. In addition, as part of our strategy to diversify our serviceable markets, we launched several key product families and technologies to enable high efficiency power conversion solutions and we plan to develop and commercialize new products in other power semiconductor markets. Our entry into the commercial markets for high-voltage power semiconductors and other markets as a result of our diversification strategy may subject us to additional and increased risk of disputes or litigation relating to these products.

Because of the complexity of the technology involved and the uncertainty of litigation generally, any intellectual property arbitration or litigation involves significant risks. Any claim of intellectual property infringement against us may require us to:

Any intellectual property claim or litigation could harm our business, results of operations, financial condition and prospects.

Global or regional economic, political and social conditions could adversely affect our business and operating results.

External factors such as potential terrorist attacks, acts of war, financial crises, such as the global or regional economic recession, or geopolitical and social turmoil in those parts of the world that serve as markets for our products could have significant adverse effect on our business and operating results in ways that cannot presently be predicted. Any future economic downturn or recession in the global economy in general and, in particular, on the economies in China, Taiwan and other countries where we market and sell our products, will have an adverse effect on our results of operations. Recently, we experienced a significant reduction in the demand for our products due to the declining PC markets, particularly from our distributors and customers in Taiwan, which have negatively impacted our revenue and profitability.

Our business operations could be significantly harmed by natural disasters or global epidemics.

We have research and development facilities located in Taiwan and the Silicon Valley in Northern California. Historically, these regions have been vulnerable to natural disasters and other risks, such as earthquakes, fires and floods, which may disrupt the local economy and pose physical risks to our property. We also have sales offices located in Taiwan and Japan where similar natural disasters and other risks may disrupt the local economy and pose physical risks to our operations. We are not currently covered by insurance against business disruption caused by earthquakes. In addition, we currently do not have redundant, multiple site capacity in the event of a natural disaster or other catastrophic event. In the event of such an occurrence, our business would suffer.

Our business could be adversely affected by natural disasters such as epidemics, outbreaks or other health crisis. An outbreak of avian flu or H1N1 flu in the human population, or another similar health crisis, could adversely affect the economies and financial markets of many countries, particularly in Asia. Moreover, any related disruptions to transportation or the free movement of persons could hamper our operations and force us to close our offices temporarily.

The occurrence of any of the foregoing or other natural or man-made disasters could cause damage or disruption to us, our employees, operations, distribution channels, markets and customers, which could result in significant delays in deliveries or substantial shortages of our products and adversely affect our business results of operations, financial condition or prospects.

Our insurance may not cover all losses, including losses resulting from business disruption or product liability claims.

We have limited product liability, business disruption or other business insurance coverage for our operations. In addition, we do not have any business insurance coverage for our operations to cover losses that may be caused by litigation or natural disasters. Any occurrence of uncovered loss could harm our business, results of operations, financial condition and prospects.

We may be adversely affected by any disruption in our information technology systems.

Our operations are dependent upon our information technology systems, which encompass all of our major business functions across offices internationally. We rely upon such information technology systems to manage and replenish inventory, complete and track customer orders, coordinate sales activities across all of our products and services, maintain vital data and information, perform financial and accounting tasks and manage and perform various administrative and human resources functions. A substantial disruption in our information technology systems for any extended time period (arising from, for example, system capacity limits from unexpected increases in our volume of business, outages or delays in our service) could result in delays in receiving inventory and supplies or filling customer orders and adversely affect our customer service and relationships. Our systems might be damaged or interrupted by natural or man−made events or by computer viruses, physical or electronic break−ins, cyber attacks and similar disruptions affecting the global Internet. There can be no assurance that such delays, problems, or costs will not have a material adverse effect on our cash flows, results of operations and financial condition.

Our international operations subject our company to risks not faced by companies without international operations.

We have adopted a global business model under which we maintain significant operations and facilities through our subsidiaries located in the U.S., China, Taiwan and Hong Kong. Our main research and development center is located in Silicon Valley, and our manufacturing and supply chain is located in China. We also have sales offices and customers throughout Asia, the U.S. and elsewhere in the world. Our international operations may subject us to the following risks:

We are subject to the risk of increased income taxes and changes in existing tax rules.

We conduct our business in multiple jurisdictions, including Hong Kong, Macau, the U.S., China, Taiwan, South Korea and Japan. The calculation of our tax liabilities involves dealing with uncertainties in the application of complex tax laws and regulations in various taxing jurisdictions. Any of these jurisdictions may assert that we have unpaid taxes. Our effective tax rates have fluctuated significantly in recent years. Our effective tax rate was (105.3)% , (887.5)% and (254.2)% for the fiscal years ended June 30, 2015 , 2014 and 2013 , respectively. Any tax rate changes in the tax jurisdictions in which we operate could result in adjustments to our deferred tax assets, if applicable, which would affect our effective tax rate and results of operations. We base our tax position upon the anticipated nature and conduct of our business and upon our understanding of the tax laws of the various countries in which we have assets or conduct activities. However, our tax position is subject to review and possible challenge by tax authorities and to possible changes in law, which may have a retroactive effect. In particular, various proposals over the years have been made to change certain U.S. tax laws relating to foreign entities with U.S. connections. In addition, the U.S. government has proposed various other changes to the U.S. international tax system, certain of which could adversely impact foreign-based multinational corporate groups, and increased enforcement of U.S. international tax laws. It is possible that these or other changes in the U.S. tax laws or proposed actions by international bodies such as the Organization of Economic Cooperation and Development (OECD) could significantly increase our U.S. or foreign income tax liability in the future.

In addition, our subsidiaries provide products and services to, and may from time to time undertake certain significant transactions with, us and other subsidiaries in different jurisdictions. We have adopted transfer pricing arrangements for transactions among our subsidiaries. Related party transactions are generally subject to close review by tax authorities, including requirements that transactions be priced at arm's length and be adequately documented. If any tax authorities were successful in challenging our transfer pricing policies or other tax judgments, our income tax expense may be adversely

affected and we could also be subject to interest and penalty charges which may harm our business, financial condition and operating results.

The imposition of U.S. corporate income tax on our Bermuda parent and non-U.S. subsidiaries could adversely affect our results of operations.

We believe that our Bermuda parent and non-U.S. subsidiaries each operate in a manner that they would not be subject to U.S. corporate income tax because they are not engaged in a trade or business in the United States. Nevertheless, there is a risk that the U.S. Internal Revenue Service may successfully assert that our Bermuda parent and non-U.S. subsidiaries are engaged in a trade or business in the United States. If our Bermuda parent and non-U.S. subsidiaries were characterized as being so engaged, we would be subject to U.S. tax at regular corporate rates on our income that is effectively connected with U.S. trade or business, plus an additional 30% "branch profits" tax on the dividend equivalent amount, which is generally effectively connected income with certain adjustments, deemed withdrawn from the United States. Any such tax could materially and adversely affect our results of operations.

We may be classified as a passive foreign investment company, which could result in adverse U.S. federal income tax consequences for U.S. holders.

Based on the current and anticipated valuation of our assets and the composition of our income and assets, we do not expect to be considered a passive foreign investment company, or PFIC, for U.S. federal income tax purposes for the foreseeable future. However, we must make a separate determination for each taxable year as to whether we are a PFIC after the close of each taxable year and we cannot assure you that we will not be a PFIC for our 2015 taxable year or any future taxable year. Under current law, a non-U.S. corporation will be considered a PFIC for any taxable year if either (1) at least 75% of its gross income is passive income or (2) at least 50% of the value of its assets, generally based on an average of the quarterly values of the assets during a taxable year, is attributable to assets that produce or are held for the production of passive income. PFIC status depends on the composition of our assets and income and the value of our assets, including, among others, a pro rata portion of the income and assets of each subsidiary in which we own, directly or indirectly, at least 25% by value of the subsidiary's equity interests, from time to time. Because we currently hold and expect to continue to hold a substantial amount of cash or cash equivalents, and because the calculation of the value of our assets may be based in part on the value of our common shares, which may fluctuate considerably given that market prices of technology companies historically often have been volatile, we may be a PFIC for any taxable year. If we were treated as a PFIC for any taxable year during which a U.S. holder held common shares, certain adverse U.S. federal income tax consequences could apply for such U.S. holder.

Risks Related to Our Industry

The average selling prices of products in our markets have historically decreased rapidly and will likely do so in the future, which could harm our revenue and gross margins.

As is typical in the semiconductor industry, the average selling price of a particular product has historically declined significantly over the life of the product. In the past, we have reduced the average selling prices of our products in anticipation of future competitive pricing pressures, new product introductions by us or our competitors and other factors. We expect that we will have to similarly reduce prices in the future for older generations of products. Reductions in our average selling prices to one customer could also impact our average selling prices to all customers. A decline in average selling prices would harm our gross margins for a particular product. If not offset by sales of other products with higher gross margins, our overall gross margins may be adversely affected. Our business, results of operations, financial condition and prospects will suffer if we are unable to offset any reductions in our average selling prices by increasing our sales volumes, reducing our costs and developing new or enhanced products on a timely basis, with higher selling prices or gross margins.

We may be adversely affected by the cyclicality of the semiconductor industry.

Our industry is highly cyclical and is characterized by constant and rapid technological change such as the introduction of smartphones and tablets that contributed to the decline in the PC market, product obsolescence and price erosion, evolving standards, uncertain product life cycles and wide fluctuations in product supply and demand. The industry has, from time to time, experienced significant and sometimes prolonged, downturns, and often connected with or in anticipation of, maturing product cycles and declines in general economic conditions. These downturns have been characterized by diminished product demand, production overcapacity, high inventory levels and accelerated erosion of average selling prices. Any future downturns, in particular the PC markets, may reduce our revenue and result in us having excess inventory. By contrast, any

upturn in the semiconductor industry could result in increased competition for access to limited third-party foundry and packaging and testing capacity, which could prevent us from benefiting from such an upturn or reduce our profit margins.

Changes in industry standards, technology, customer requirements and government regulation could limit our ability to sell our products.

The semiconductor industry is characterized by changing demand for new and advanced functions, long design and sales cycles, rapid product obsolescence and price erosion, intense competition, evolving industry standards and wide fluctuations in product supply and demand. Changes in industry standards, or the development of new industry standards, or, when applicable, government approval or disapproval of industry standards may make our products obsolete or negate the cost advantages we believe we have in our products. We may be required to invest significant effort and to incur significant expense to redesign our products in order to address relevant standards, technological developments, customer requirements or regulations but may not have the financial resources to respond to these changes effectively or in a timely manner. Any inability to meet these standards, regulations and requirements could harm our business, results of operations, financial condition and prospects.

Risks Related to Doing Business in China

China's economic, political and social conditions, as well as government policies, could affect our business and growth.

Our financial results have been, and are expected to continue to be, affected by the economy in China. A slowdown of economic growth in China or other adverse developments could harm our business, results of operations, financial condition and prospects.

The China economy differs from the economies of most developed countries in many respects, including:

The Chinese economy has been transitioning from a planned economy to a more market-oriented economy. Although in recent years the China government has implemented measures emphasizing the utilization of market forces for economic reform, the reduction of state ownership of productive assets and the establishment of corporate governance in business enterprises, the China government continues to retain significant control over the business and productive assets in China. Any changes in China's government policy or China's political, economic and social conditions, or in relevant laws and regulations, may adversely affect our current or future business, results of operation or financial condition. These changes in government policy may be implemented through various means, including changes in laws and regulations, implementation of anti-inflationary measures, change of basic interest rate, changes in the tax rate or taxation system and the imposition of additional restrictions on currency conversion and imports. Furthermore, given China's largely export-driven economy, any changes in the economies of the China's principal trading partners and other export-oriented nations may adversely affect our business, results of operations, financial condition and prospects.

Our ability to successfully expand our business operations in China depends on a number of factors, including macroeconomic and other market conditions, and credit availability from lending institutions. In response to the recent global and Chinese economic recession, the China government has promulgated several measures aimed at expanding credit and stimulating economic growth. We cannot assure you that the various macroeconomic measures, monetary policies and economic stimulus package adopted by the China government to guide economic growth will be effective in maintaining or sustaining the growth rate of the Chinese economy. If measures adopted by the China government fail to achieve further growth in the Chinese economy, it may adversely affect our growth, business strategies and operating results. In addition, changes in political and social conditions of China may adversely affect our ability to conduct our business in the region. For example, geopolitical disputes and increased tensions between China and its neighboring countries in which we conduct business could make it more difficult for us coordinate and manage our international operations in such countries.

Changes in China's laws, legal protections or government policies on foreign investment in China may harm our business.

Our business and corporate transactions are subject to laws and regulations applicable to foreign investment in China as well as laws and regulations applicable to foreign-invested enterprises. These laws and regulations frequently change, and their interpretation and enforcement involves uncertainties that could limit the legal protections available to us. Regulations and rules on foreign investments in China impose restrictions on the means that a foreign investor like us may apply to facilitate corporate transactions we may undertake. In addition, the Chinese legal system is based in part on government policies and internal rules, some of which are not published on a timely basis or at all, that may have a retroactive effect. As a result we may not be aware of our violation of these policies and rules until some time after the violation. If any of our past operations are deemed to be non-compliant with Chinese law, we may be subject to penalties and our business and operations may be adversely affected. For instance, under the catalogue for the Guidance of Foreign Investment Industries, some industries are categorized as sectors which are encouraged, restricted or prohibited for foreign investment. As the catalogue for the Guidance of Foreign Investment Industries is updated every few years, there can be no assurance that the China government will not change its policies in a manner that would render part or all of our business to fall within the restricted or prohibited categories. If we cannot obtain approval from relevant authorities to engage in businesses which become prohibited or restricted for foreign investors, we may be forced to sell or restructure a business which has become restricted or prohibited for foreign investment. Furthermore, the China government has broad discretion in dealing with violations of laws and regulations, including levying fines, revoking business and other licenses and requiring actions necessary for compliance. In particular, licenses and permits issued or granted to us by relevant governmental bodies may be revoked at a later time by higher regulatory bodies. If we are forced to adjust our corporate structure or business as a result of changes in government policy on foreign investment or changes in the interpretation and application of existing or new laws, our business, financial condition, results of operations and prospects may be harmed. Moreover, uncertainties in the Chinese legal system may impede our ability to enforce contracts with our business partners, customers and suppliers, or otherwise pursue claims in litigation to recover damages or loss of property, which could adversely affect our business and operations.

Limitations on our ability to transfer funds to our China subsidiaries could adversely affect our ability to expand our operations, make investments that could benefit our businesses and otherwise fund and conduct our business.

The transfer of funds from us to our China subsidiaries, either as a shareholder loan or as an increase in registered capital, is subject to registration with or approval by the China's governmental authorities, including the State Administration of Foreign Exchange, or SAFE, or the relevant examination and approval authority. Our subsidiaries may also experience difficulties in converting our capital contributions made in foreign currencies into RMB due to changes in the China's foreign exchange control policies. Therefore, it may be difficult to change capital expenditure plans once the relevant funds have been remitted from us to our China subsidiaries. These limitations and the difficulties our China subsidiaries may experience on the free flow of funds between us and our China subsidiaries could restrict our ability to act in response to changing market situations in a timely manner.

China's currency exchange control and government restrictions on investment repatriation may impact our ability to transfer funds outside of China.

A significant portion of our business is conducted in China where the currency is the Renminbi. Regulations in China permit foreign owned entities to freely convert the Renminbi into foreign currency for transactions that fall under the "current account," which includes trade related receipts and payments, interest and dividends. Accordingly, our Chinese subsidiaries may use Renminbi to purchase foreign exchange for settlement of such "current account" transactions without pre-approval. However, pursuant to applicable regulations, foreign‑invested enterprises in China may pay dividends only out of their accumulated profits, if any, determined in accordance with Chinese accounting standards and regulations. In calculating accumulated profits, foreign investment enterprises in China are required to allocate at least 10% of their accumulated profits each year, if any, to fund certain reserve funds, including mandated employee benefits funds, unless these reserves have reached 50% of the registered capital of the enterprises.

Other transactions that involve conversion of Renminbi into foreign currency are classified as "capital account" transactions; examples of "capital account" transactions include repatriations of investment by or loans to foreign owners, or direct equity investments in a foreign entity by a China domiciled entity. "Capital account" transactions require prior approval from China's State Administration of Foreign Exchange (SAFE) or its provincial branch to convert a remittance into a foreign currency, such as U.S. dollars, and transmit the foreign currency outside of China.

As a result of these and other restrictions under PRC laws and regulations, our China subsidiaries are restricted in their abil ity to transfer a portion of their net assets to the parent; such restricted portion amounted to approximately $86.8 million, or 31.4% of our total consolidated net assets as of June 30, 2015 . We have no assurance that the relevant Chinese governmental authorities in the future will not limit further or eliminate the ability of our China subsidiaries to purchase foreign currencies and transfer such funds to us to meet our liquidity or other business needs. Any inability to access funds in

China, if and when needed for use by the Company outside of China, could have a material and adverse effect on our liquidity and our business.

Our result of operations may be negatively impacted by fluctuations in foreign currency exchange rates between U.S. dollars and Chinese Yuan, or RMB.

While U.S. dollars is our main functional currency and our revenue and a significant portion of our operating expenses are denominated in U.S. dollars, we are required to maintain local currencies, primarily the RMB, in our cash balances in connection with the funding of our oversea operations.  As a result, our costs and operating expenses may be exposed to adverse movements in foreign currency exchange rates between the U.S. dollars and RMB.  We also do not utilize any financial instruments to hedge or reduce potential losses due to the fluctuation of foreign currency exchange rates.  In general, any appreciation of U.S. dollars against a weaker RMB could reduce the value of our cash and cash equivalent balance, which could increase our operating expenses and negatively affect our cash flow, income and profitability.  The value of RMB against the U.S. dollars may fluctuate and is affected by many factors outside of our control, including changes in political and economic conditions, implementation of new monetary policies by the Chinese government and changes in banking regulations, and there is no guarantee that we will be able to mitigate or recoup any losses due to a significant fluctuation in the U.S. dollars/RMB exchange rates.

Controversies affecting China's trade with the United States could harm our business.

While China has been granted permanent most favored nation trade status in the United States through its entry into the World Trade Organization, controversies between the United States and China may arise that threaten the trading relationship between the two countries. At various times during recent years, the United States and China have had disagreements over political and economic issues. In addition, disagreements between the United States and China with respect to their political, military or economic policies toward Taiwan may contribute to further controversies. These controversies and trade frictions could have a material adverse effect on our business by, among other things, making it more difficult for us to coordinate our operations between the United States and China or causing a reduction in the demand for our products by customers in the United States or China.

Relations between Taiwan and China could negatively affect our business, financial condition and operating results and, therefore, the market value of our common shares.

Taiwan has a unique international political status. China does not recognize the sovereignty of Taiwan. Although significant economic and cultural relations have been established during recent years between Taiwan and China, relations have often been strained. A substantial number of our key customers and some of our essential sales and engineering personnel are located in Taiwan, and we have a large number of operational personnel and employees located in China. Therefore, factors affecting military, political or economic relationship between China and Taiwan could have an adverse effect on our business, financial condition and operating results.

Risks Related to Our Corporate Structure and Our Common Shares

Our share price may be volatile and you may be unable to sell your shares at or above the purchase price, if at all.

Limited trading volumes and liquidity of our common shares on the NASDAQ Global Market may limit the ability of shareholders to purchase or sell our common shares in the amounts and at the times they wish.  In addition, the financial markets in the United States and other countries have experienced significant price and volume fluctuations, and market prices of technology companies have been and continue to be extremely volatile. The trading price of our common shares on The NASDAQ Global Market ranged from a low of $6.83 to high of $17.91 from the commencement of the public trading of our common shares on April 29, 2010, to July 31, 2015 and from a low of $8.16 to high of $10.82 from July 1, 2014 to June 30, 2015 . Volatility in the price of our shares may be caused by factors outside our control and may be unrelated or disproportionate to our operating results.

The market price for our common shares may be volatile and subject to wide fluctuations in response to factors, including:

In the past, securities class action litigation has often been brought against a company following periods of volatility in such company's share price.  This type of litigation could result in substantial costs and divert our management's attention and resources which could negatively impact our business and financial conditions.

If securities or industry analysts do not publish research or reports about our business, or if they adversely change their recommendations regarding our common shares or if our operating results do not meet their expectations, the trading price of our common shares could decline.

The market price of our common shares is influenced by the research and reports that industry or securities analysts publish about us or our business. There is no guarantee that these analysts will understand our business and results, or that their reports will be accurate or correctly predict our operating results or prospects. If one or more of these analysts cease coverage of our company or fail to publish reports on us regularly, we could lose visibility in the financial markets, which in turn could cause the market price of our common shares or its trading volume to decline. Moreover, if one or more of the analysts who cover our company downgrade our common shares or if our operating results or prospects do not meet their expectations, the market price of our common shares could decline significantly.

Anti-takeover provisions in our bye-laws could make an acquisition of us more difficult and may prevent attempts by our shareholders to replace or remove our current management.

Certain provisions in our bye-laws may delay or prevent an acquisition of us or a change in our management. In addition, by making it more difficult for shareholders to replace members of our board of directors, these provisions also may frustrate or prevent any attempts by our shareholders to replace or remove our current management because our board of directors is responsible for appointing the members of our management team. These provisions include:

These provisions could make it more difficult for a third-party to acquire us, even if the third-party's offer may be considered beneficial by many shareholders. As a result, shareholders may be limited in their ability to obtain a premium for their shares.

Insiders have substantial control over us, which could adversely affect the market price of our shares.

Our Chief Executive Officer, certain members of our management and directors, beneficially owned, in the aggregate, approximately 19.9% of our outstanding common shares as of June 30, 2015 . As a result, these shareholders will be able to exert significant control over all matters requiring shareholder approval, including the election of directors and approval of significant corporate transactions, such as a merger, consolidation, takeover or other business combination involving us. This concentration of ownership may also discourage, delay or prevent a change in control of our company, which could deprive our shareholders of an opportunity to receive a premium for their shares as part of a sale of our company and may reduce the trading price of our shares. Furthermore, the interests of these insiders could conflict with the interests of our other shareholders and, accordingly, any of them may take actions that favor their own interests and which may not be in the best interests of our other shareholders. These actions may be taken even if they are opposed by our other shareholders.

Item 1B.     Unresolved Staff Comments

None.

Item 2.    Properties

As of July 31, 2015 , our primary U.S. facility, which houses our research and design function, as well as elements of marketing and administration, is located in Sunnyvale, California. We conduct our manufacturing, research and development, sales and marketing and administration in Asia and North America. We lease all properties used in our business except the wafer fabrication facility in Oregon acquired in January 2012. The following table sets forth the location, size and primary use of our properties:

We believe that our current facilities are adequate and that additional space will be available on commercially reasonable terms for the foreseeable future.

We are currently not a party to any material legal proceedings. We have in the past, and may from time to time in the future, become involved in legal proceedings arising from the normal course of business activities.  The semiconductor industry is characterized by frequent claims and litigation, including claims regarding patent and other intellectual property rights as well as improper hiring practices. Irrespective of the validity of such claims, we could incur significant costs in the defense thereof or could suffer adverse effects on our operations.

Item 4.         Mine Safety Disclosures

Not Applicable.

PART II

Market Price of Our Common Shares

Our common shares have traded on the NASDAQ Global Market since April 29, 2010 under the symbol AOSL. The following table sets forth, for the periods indicated, the high and low sales prices of our common share as reported by the NASDAQ Global Market.

Holders of Our Common Shares

As of July 31, 2015 , there were approximately 102 holders of record of our common shares, not including those shares held in street or nominee name.

Dividend Policy

We have never declared or paid cash dividends on our common shares. We currently intend to retain all available funds and any future earnings for use in the operation of our business and do not anticipate paying any dividends on our common share in the foreseeable future. Any future determination to declare dividends will be made at the discretion of our board of directors and will depend on our financial condition, operating results, capital requirements, general business conditions and other factors that our board of directors may deem relevant.

Securities Authorized for Issuance Under Equity Compensation Plans

See Item 12 of Part III of this report regarding information about securities authorized for issuance under our equity compensation plans.

Share Performance Graph

The following graph compares the total cumulative shareholder return on our common shares with the total cumulative return of the NASDAQ Composite Index and the Philadelphia Semiconductor Index for the period from April 29, 2010 (the date our common share commenced trading on the NASDAQ Global Market) through June 30, 2015 , the end of our last fiscal year. The graph assumes an investment of $100 on April 29, 2010 and the reinvestment of any dividends for NASDAQ Composite Index and Philadelphia Semiconductor Index.

The comparisons in the graph below are required by the SEC and are not intended to forecast or be indicative of possible future performance of our common shares.

The above Stock Performance Graph and related information shall not be deemed "soliciting material" or to be "filed" with the Securities and Exchange Commission, nor shall such information be incorporated by reference into any future filing under the Securities Act of 1933 or Securities Exchange Act of 1934, each as amended, except to the extent that the Company specifically incorporates it by reference into such filing.

Purchases of Equity Securities by the Issuer and Affiliated Purchasers

On May 8, 2014, our Board of Directors approved to reactivate the share repurchase program which was originally authorized on October 22, 2010 for a total amount of $25.0 million. In April 2015, our Board of Directors approved an increase in the remaining available amount under our share repurchase program from approximately $17.8 million to $50.0 million. The repurchases may be made from the open market or through privately negotiated transactions. Open market repurchases will be made pursuant to a pre-established 10b5-1 trading plan with specified amount of shares and price for the repurchases. The amount and timing of any repurchases will depend on a number of factors, including but not limited to, the trading price, volume and availability of our common shares, applicable legal requirements, our business and financial conditions and general market environment. We account for treasury stock under the cost method. Shares repurchased are accounted for as treasury shares and the total cost of shares repurchased is recorded as a reduction of shareholders' equity.

The following table sets for the share repurchases under this program during the fiscal quarter ended June 30, 2015:

In June 2015, we commenced a modified Dutch auction tender offer (the "Tender Offer") to repurchase an aggregate of $30.0 million of our outstanding common shares with a price range between $8.50 and $9.20 per share. In July 2015, we

completed the Tender Offer in which we purchased 3,296,703 shares of its common shares, at a purchase price of $9.10 per share, for an aggregate purchase price of $30.0 million, excluding fees and expenses relating to the Tender Offer. These shares represent approximately 12.53% of the total number of the Company's common shares issued and outstanding as of June 30, 2015. The Tender Offer was part of the $50.0 million share repurchase program approved by the Board in April 15, 2015. Immediately following the completion of the Tender Offer, approximately $18.2 million remained available under such share repurchase program.

Item 6. Selected Financial Data

We have derived the selected consolidated statements of operations data for the fiscal years ended June 30, 2015 , 2014 and 2013 and selected consolidated balance sheet data as of June 30, 2015 and 2014 from our audited consolidated financial statements and related notes included elsewhere in this report. We have derived the selected consolidated statements of operations data for the fiscal years ended June 30, 2012 and 2011 and selected consolidated balance sheets as of June 30, 2013 , 2012 and 2011 from consolidated financial statements not included in this report. The information set forth below is not necessarily indicative of results of future operations, and should be read in conjunction with Item 7, "Management's Discussion and Analysis of Financial Condition and Results of Operations" in this Annual Report on Form 10-K.

You should read the following discussion of the financial condition and results of our operations in conjunction with our consolidated financial statements and the notes to those statements included elsewhere in this annual report. Our consolidated financial statements contained in this annual report are prepared in accordance with U.S. GAAP.

Overview

We are a designer, developer and global supplier of a broad portfolio of power semiconductors. Our portfolio of power semiconductors includes approximately 1,500 products, and has grown significantly with the introduction of over 100 new products during each of the fiscal years ended June 30, 2015 , 2014 and 2013 . Our teams of scientists and engineers have developed extensive intellectual properties and technical knowledge that encompass major aspects of power semiconductors, which we believe it enables us to introduce and develop innovative products to address the increasingly complex power requirements of advanced electronics. We have an extensive patent portfolio that consists of 517 patents and 193 patent applications in the United States as of June 30, 2015 . We differentiate ourselves by integrating our expertise in technology, design and advanced manufacturing and packaging to optimize product performance and cost. Our portfolio of products targets high-volume applications, including personal computers, flat panel TVs, LED lighting, smart phones, battery packs, consumer and industrial motor controls and power supplies for TVs, computers, servers and telecommunications equipment.

During the fiscal year ended June 30, 2015 , we continued our diversification program by developing new silicon and packaging platforms to expand our serviceable available market, or SAM and offer higher performance products. Our metal-oxide-semiconductor field-effect transistors, or MOSFET, portfolio expanded significantly across a full range of voltage applications. For example, during the three months ended June 30, 2015, we introduced the new 1200V/1350V E-series IGBTs optimized for soft-switching applications which delivers high performance by lower switching loss. We also expanded our IGBT product portfolio with the release of the 650V M-Series. This platform optimizes for superior performance with higher robustness in addition to fast and soft turn-off switching in motor drives. During the three months ended March 31, 2015, we released two new MOSFETs optimized for battery protection applications which are the latest additions to our state-of-the-art AlphaDFN™ package portfolio. These devices are specifically targeting one and two cells portable battery pack applications. During the three months ended December 31, 2014, we launched new generation EZBuck(TM) regulator in a thermally enhanced package. The device offers a low on-resistance power stage in a thermally enhanced 3mm x 3mm DFN package, allowing cooler power conversion for a variety of consumer electronics applications such as LCD TVs, set-top-boxes, as well as DVD players and recorders. We also introduced new 40V 0.99mOhm MOSFET in a DFN5x6 package during the three months ended December 31, 2014. The device is to address a wide range of applications including primary-side and secondary-side switching in telecom and industrial DC/DC converters, secondary-side synchronous rectification in DC/DC and AC/DC converters, as well as POL modules for telecom systems. During the three months ended September 30, 2014, we rolled out new family of 25-V and 30-V high performance MOSFETs in compact 3 x 3mm DFN packages. These devices are ideally suited for a variety of DC/DC step-down conversion solutions for personal computing, gaming, servers, and telecom/datacom applications. We also enhanced the EZPower(TM) smart load switch portfolio with rapid turn-off fault protection and current monitoring. The device has an operating input voltage range from 5-V to 16-V and is capable of supplying up to 6A of continuous current. A low on-resistance of 23mΩ in a thermally enhanced 3mm x 3mm DFN package makes the AOZ1363 optimal for space-constrained applications that require circuit protection such as the latest notebook PCs, hot swap supplies and micro servers.

Our business model leverages global resources, including research and development and manufacturing in the United States and Asia. Our sales and technical support teams are localized in several growing markets. We operate a 200mm wafer fabrication facility located in Hillsboro, Oregon, or the Oregon fab, which is critical for us to accelerate proprietary technology development, new product introduction and improve our financial performance in the long run. To meet the market demand for the more mature high volume products, we also utilize the wafer manufacturing capacity of selected third party foundries. For assembly and test, we primarily rely upon our in-house facilities in China. In addition, we utilize subcontracting partners for industry standard packages. We believe our in-house packaging and testing capability provides us with a competitive advantage in proprietary packaging technology, product quality, cost and sales cycle time.

Factors affecting our performance

Our performance is affected by several key factors, including the following:

The global, regional economic and PC market conditions : Because our products primarily serve consumer electronic applications, a deterioration of the global and regional economic conditions could materially affect our revenue and results of operations. In particular, because a significant amount of our revenue is derived from sales of products in the personal

computer, or PC markets, such as notebooks, motherboards and notebook battery packs, a significant decline or downturn in the PC markets can have a material adverse effect on our revenue and results of operations.  Our revenue from the PC markets accounted for approximately 47.1%, 45.2% and 50.0% of our total revenue for the years ended June 30, 2015 , 2014 and 2013 , respectively.

Since the beginning of calendar year 2013, we have experienced a significant global decline in the PC markets due to continued growth of demand in tablets and smart phones, worldwide economic conditions and the industry inventory correction which had and may continue to have a material negative impact on the demand for our products, revenue, factory utilization, gross margin, our ability to resell excess inventory, and other performance measures. In response to this trend, we have been and are continuing to execute our strategies to diversify our product portfolio, penetrate into other market segments, including the consumer, communications and industrial markets, improve gross margin and profit by implementing cost control measures. We are making progress in reducing our reliance on the computing market, and we are also committed to continue to support our computing business and capitalize on the opportunity with a more focused and competitive PC product strategy. However, as we develop and sell new products that serve more diversified markets, we expect that sales based on the PC markets, as a percentage of the total revenue, will continue to decline. If the rate of decline in the PC markets is faster than we expected, or if we cannot successfully diversify or introduce new products to keep pace with the declining PC markets, we may not be able to alleviate its negative impact, which will adversely affect our results of operations.

Manufacturing Costs :  Our gross margin may be affected by our manufacturing costs, including utilization of our own manufacturing facilities, pricing of wafers from other foundries and semiconductor raw materials, which may fluctuate from time to time largely due to the market demand and supply.  Capacity utilization affects our gross margin because we have certain fixed costs associated with our in-house packaging and testing facilities and our Oregon fab.  If we are unable to utilize the capacity of our in-house manufacturing facilities at a desired level, our gross margin may be adversely affected. For example, we may experience lower capacity utilization at our factories as a result of declining PC markets, which could adversely affect our gross margin and profitability. 

Erosion of average selling price: Erosion of average selling prices of established products is typical in our industry. Consistent with this historical trend, we expect that average selling prices of our existing products will continue to decline in the future. However, as a normal course of business, we seek to offset the effect of declining average selling prices by introducing new and higher value products, expanding existing products for new applications and new customers, and reducing manufacturing cost of existing products.

Product introductions and customers' product requirements: Our success depends on our ability to introduce products on a timely basis that meet or are compatible with our customers' specifications and performance requirements. Both factors, timeliness of product introductions and conformance to customers' requirements, are equally important in securing design wins with our customers. As we accelerate the development of new technology platforms, we expect to increase the pace at which we introduce new products and obtain design wins. Our failure to introduce products on a timely basis that meet customers' specifications and performance requirements, particularly those products with major OEM customers, and our inability to continue to expand our serviceable markets, could adversely affect our financial performance, including loss of market shares with customers.

Distributor ordering patterns and seasonality : Our distributors place purchase orders with us based on their forecasts of end customer demand, and this demand may vary significantly depending on the sales outlooks and market and economic conditions of end customers. Because these forecasts may not be accurate, channel inventory held at our distributors may fluctuate significantly, which in turn may prompt distributors to make significant adjustments to their purchase orders placed with us. As a result, our revenue and operating results may fluctuate significantly from quarter to quarter. In addition, because our products are used in consumer electronics products, our revenue is subject to seasonality. Our sales seasonality is affected by numerous factors, including global and regional economic conditions as well as the PC market conditions, revenue generated from new products, changes in distributor ordering patterns in response to channel inventory adjustments and end customer demand for our products and fluctuations in consumer purchase patterns prior to major holiday seasons. In recent periods, broad fluctuations in the semiconductor markets and the global and regional economic conditions, in particular the decline of the PC market conditions, have had a more significant impact on our results of operations than seasonality.

Principal line items of statements of income

The following describes the principal line items set forth in our consolidated statements of operations:

Revenue

We generate revenue primarily from the sale of power semiconductors, consisting of power discretes and power ICs. Historically, a majority of our revenue was derived from power discrete products and a smaller amount was derived from power IC products. Because our products typically have three-year to five-year life cycles, the rate of new product introduction is an important driver of revenue growth over time. We believe that expanding the breadth of our product portfolio is important to our business prospects, because it provides us with an opportunity to increase our total bill-of-materials within an electronic system and to address the power requirements of additional electronic systems. In addition, a small percentage of our total revenue is generated by providing packaging and testing services to third-parties through one of our subsidiaries.

Our product revenue includes the effect of the estimated stock rotation returns and price adjustments that we expect to provide to our distributors. Stock rotation returns are governed by contract and are limited to a specified percentage of the monetary value of products purchased by the distributor during a specified period. At our discretion or upon our direct negotiations with the original design manufacturers ("ODMs") or original equipment manufacturers ("OEMs"), we may elect to grant special pricing that is below the prices at which we sold our products to the distributors. In these situations, we will grant price adjustments to the distributors reflecting such special pricing. We estimate the price adjustments for inventory at the distributors based on factors such as distributor inventory levels, pre-approved future distributor selling prices, distributor margins and demand for our products.

Cost of goods sold

Our cost of goods sold primarily consists of costs associated with semiconductor wafers, packaging and testing, personnel, including share-based compensation expense, overhead attributable to manufacturing, operations and procurement, and cost associated with yield improvements, capacity utilization, warranty and inventory reserves. As the volume of sales increases, we expect cost of goods sold to increase. We implemented a process to improve our factory capacity utilization rates by transferring more wafer production to our Oregon fab and reducing our reliance on outside foundries. While our utilization rates cannot be immune to the market conditions, our goal is to make them less vulnerable to market fluctuations. We believe our market diversification strategy and product growth will drive higher volume of manufacturing which will improve our factory utilization rates and gross margin in the long run.

Operating expenses

Our operating expenses consist of research and development, selling, general and administrative expenses and impairment of long-lived assets. We expect that our total operating expenses will generally increase over time due to our belief that our business will continue to grow. However, our operating expenses as a percentage of revenue may fluctuate from period to period.

Research and development expenses.  Our research and development expenses consist primarily of salaries, bonuses, benefits, share-based compensation expense, expenses associated with new product prototypes, travel expenses, fees for engineering services provided by outside contractors and consultants, amortization of software and design tools, depreciation of equipment and overhead costs for research and development personnel. As we continue to invest significant resources in developing new technologies and products, we expect our research and development expenses to increase.

Selling, general and administrative expenses.  Our selling, general and administrative expenses consist primarily of salaries, bonuses, benefits, share-based compensation expense, product promotion costs, occupancy costs, travel expenses, expenses related to sales and marketing activities, amortization of software, depreciation of equipment, maintenance costs and other expenses for general and administrative functions as well as costs for outside professional services, including legal, audit and accounting services. We expect our selling, general and administrative expenses to increase as we expand our business.

Impairment of Long-Lived Assets: Long-lived assets or asset groups are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset might not be recoverable. The recoverability of an asset or asset group is assessed by determining if the carrying value of the asset or asset group exceeds the sum of the projected undiscounted cash flows expected to result from the use and eventual disposition of the assets over the remaining economic life.  The impairment loss is measured based on the difference between the carrying amount and estimated fair value.

Income tax expense

We are subject to income taxes in various jurisdictions. Significant judgment and estimates are required in determining our worldwide income tax expense. The calculation of tax liabilities involves dealing with uncertainties in the application of complex tax regulations of different jurisdictions globally. We establish accruals for potential liabilities and contingencies based on a more likely than not threshold to the recognition and de-recognition of uncertain tax positions. If the recognition

threshold is met, the applicable accounting guidance permits us to recognize a tax benefit measured at the largest amount of tax benefit that is more than likely to be realized upon settlement. If the actual tax outcome of such exposures is different from the amounts that were initially recorded, the differences will impact the income tax and deferred tax provisions in the period in which such determination is made. Changes in the location of taxable income (loss) could result in significant changes in our income tax expense.

We record a valuation allowance against deferred tax assets if it is more likely than not that a portion of the deferred tax assets will not be realized, based on historical profitability and our estimate of future taxable income in a particular jurisdiction. Our judgments regarding future taxable income may change due to changes in market conditions, changes in tax laws, tax planning strategies or other factors. If our assumptions and consequently our estimates change in the future, the deferred tax assets may increase or decrease, resulting in corresponding changes in income tax expense. Our effective tax rate is highly dependent upon the geographic distribution of our worldwide profits or losses, the tax laws and regulations in each geographical region where we have operations, the availability of tax credits and carry-forwards and the effectiveness of our tax planning strategies.

Operating results

The following tables set forth our results of operations and as a percentage of revenue for the fiscal years ended June 30, 2015 , 2014 and 2013 . Our historical results of operations are not necessarily indicative of the results for any future period.

(1) Includes share-based compensation expense allocated as follows:

Revenue

The following is a summary of revenue by product type:

Fiscal 2015 vs 2014

Total revenue was $327.9 million for fiscal year 2015 , an increase of $9.8 million , or 3.1% , as compared to $318.1 million for fiscal year 2014 . The increase consisted of $2.7 million and $9.5 million in sales of power discrete products and sales of power IC products, respectively, partially offset by a $2.4 million decrease in sales of packaging and testing services. The increase in power discrete and power IC products was primarily due to an 11.0% increase in unit shipments, partially offset by a 6.3% decrease in average selling price as compared to the same period of last year mainly due to selling price erosion in the computing and consumer markets and to a lesser extent, a shift in product mix. The decrease in revenue of packaging and testing services as compared to last year was primarily due to reduced demand as a result of the declining PC market. In response to the declining PC market, we have been executing and are continuing to execute strategies to diversify our product portfolio and penetrate into other market segments, which we believe would mitigate and eventually overcome the reduced demand resulting from the declining PC market. During fiscal year 2015, we accelerated the development of new technology platforms which allowed us to introduce 61 medium and high voltage MOSFET products, targeting the consumer, power supply and industrial markets, as well as 32 low voltage MOSFET products for the computing and communication markets. In addition, we introduced 15 Power IC new products for consumer, communication and computing applications.

Fiscal 2014 vs 2013

Total revenue was $318.1 million for fiscal year 2014, a decrease of $19.3 million, or 5.7%, as compared to $337.4 million for fiscal year 2013. The decrease consisted of $19.1 million and $1.4 million decrease in sales of power discrete products and packaging and testing services, respectively, partially offset by an increase in sales of power IC products of $1.2 million. The net decrease in product revenue, including power discrete and power IC products was mainly a result of a 7.0% decrease in average selling price primarily due to selling price erosion in the computing and consumer markets as compared to fiscal year 2013, partially offset by a 1.2% increase in unit shipments and to a lesser extent, a shift in product mix as a result of reduced demand for our products related to PC applications. The decrease in revenue of packaging and testing services as compared to last year was primarily due to reduced demand as a result of the declining PC market.

Fiscal 2015 vs 2014

Cost of goods sold was $267.5 million for fiscal year 2015 , an increase of $8.4 million , or 3.2% , as compared to $259.1 million for fiscal year 2014 , primarily due to increased unit shipments. The increase was partially offset by overall manufacturing cost reduction due to continued cost control efforts and improved factory utilization as compared to last fiscal year. Gross margin decreased by 0.2 percentage points to 18.4% for fiscal year 2015 , as compared to 18.6% for fiscal year 2014 . The slight decrease in gross margin was primarily due to reduced average selling price as a result of price erosion during the current year, partially offset by the positive impact of improved factory utilization and continued cost reduction efforts during the current fiscal year. We expect our gross margin to continue to fluctuate in the future as a result of variations in our

product mix, factory utilization, semiconductor wafer and raw material pricing, manufacturing labor cost and general economic and PC market conditions.

Fiscal 2014 vs 2013

Cost of goods sold was $259.1 million for fiscal year 2014, a decrease of $13.8 million, or 5.1%, as compared to $272.9 million for fiscal year 2013, primarily as a result of the overall manufacturing cost reduction due to continued cost control efforts and factory utilization improvement during fiscal year 2014 as well as the impact of the $7.7 million non-recurring inventory write-down during fiscal year 2013 for certain excess and obsolete inventory consisting of developed products for PC applications for a major OEM that were not compatible with its particular applications, which had subsequently been fully resolved. Gross margin decreased by 0.5 percentage points to 18.6% for fiscal year 2014, as compared to 19.1% for fiscal year 2013. The decrease in gross margin was primarily due to reduced average selling price mainly as a result of lower demand in the declining PC market during the current year, despite the $7.7 million non-recurring inventory write-down in fiscal year 2013, partially offset by the positive impact of improved factory utilization and continued factory cost reduction efforts during the fiscal year 2014.

Research and development expenses

Fiscal 2015 vs 2014

Research and development expenses were $27.1 million for fiscal year 2015 , an increase of $2.7 million , or 10.9% , as compared to $24.4 million for fiscal year 2014 . The increase was primarily attributable to a $3.4 million increase in product prototyping engineering expenses, partially offset by a $0.1 million decrease in employee compensation and benefit expenses primarily due to reduction of headcount and less bonus during current year, a $0.1 million decrease in depreciation and amortization expense as a result of increased fully depreciated assets, a $0.2 million decrease in facilities and utilities related costs primarily due to continued operational and cost control effort, and a $0.2 million decrease in legal and consulting expense due to reduced consulting activities. We continue to evaluate and invest resources in developing new technologies and products utilizing our own fabrication and packaging facilities. However, we expect that our research and development expenses will fluctuate from time to time.

Fiscal 2014 vs 2013

Research and development expenses were $24.4 million for fiscal year 2014, a decrease of $3.4 million, or 12.3%, as compared to $27.8 million for fiscal year 2013. The decrease was primarily attributable to a $2.6 million decrease in product prototyping engineering expenses mainly due to temporary shut downs of the Company as cost control measures, $0.6 million decrease in shared-based compensation expense primarily due to increased cancellations of stock options and rewards, $0.2 million decrease in depreciation and amortization expenses as a result of certain assets were fully amortized in fiscal year of 2013.

Selling, general and administrative expenses

Fiscal 2015 vs 2014

Selling, general and administrative expenses were $37.2 million for fiscal year 2015 , an increase of $2.3 million , or 6.7% , as compared to $34.9 million for fiscal year 2014 . The increase was primarily due to a $1.8 million increase in employee

compensation and benefits expense as a result of increased headcount during current year, a $1.1 million increase in share-based compensation expense primarily as a result of an increase of stock awards granted and a decrease of cancellation during the current year, and a $0.4 million in recovery of doubtful accounts in last fiscal year as a result of continued effort in collection from a service customer. These increases were partially offset by a $0.7 million decrease in unrealized foreign exchange losses mainly due to recent depreciation of USD against RMB and a $0.3 million decrease in depreciation and amortization expense as a result of certain assets being fully depreciated in fiscal year of 2015.

Selling, general and administrative expenses were $34.9 million for fiscal year 2014, a decrease of $0.6 million, or 1.7%, as compared to $35.5 million for fiscal year 2013. The decrease was primarily due to a $0.7 million decrease in share-based compensation due to increased cancellations of stock options and awards during the current year, a $0.7 million decrease in depreciation and amortization expenses primarily due to certain assets that were fully amortized in fiscal year 2013 and less acquisitions of fixed assets during the current year, a $0.3 million decrease in marketing and commission expenses due to reduced sales and marketing activities, a $0.4 million in recovery of doubtful accounts as a result of continued effort in collection from a service customer in current fiscal year, as well as a $0.4 million decrease in audit and tax consulting fees due to reduced related consulting activities. These decreases were partially offset by a $0.8 million increase in unrealized foreign exchange losses related to our cash and cash equivalents denominated in Renminbi or RMB, held by our subsidiaries in China, caused by the recent appreciation of USD against RMB, and a $0.8 million increase in employee compensation and benefits due to headcount increase, as well as a $0.3 million of business tax refunds of a subsidiary in China during fiscal year 2013

Impairment of long-lived assets

During the third quarter of fiscal year 2013, in light of the unfavorable market conditions particularly related to the accelerated decline of the PC market, we conducted an in-depth analysis of our strategic plan. In our review, we reconsidered the key assumptions in our overall strategic business and manufacturing capacity plans in light of the continued declines in the PC market. As a result, we revised our PC related revenue and volume outlook as well as our manufacturing capacity requirements. These material changes in our outlook and plans, which we were able to determine in the third quarter of fiscal 2013, triggered an impairment review of our long-lived assets.

We determined that the related estimated undiscounted cash flows were not sufficient to recover the carrying value of certain manufacturing machinery and equipment primarily for the packaging of our PC-related products due to the accelerated decline of the PC markets. The average remaining useful life of those impaired assets was approximately two years. We estimated the fair values of those long-lived assets based on net realizable values of similar machinery and equipment recently transacted by third-party used-machine brokers and recorded an asset impairment charge of approximately $2.6 million to reduce the related carrying amount to its estimated fair value as of March 31, 2013.

During the fourth quarter of fiscal year 2015 and 2014, we evaluated our amortizable intangible assets for impairment and determined that the related estimated undiscounted cash flows exceeded the carrying value of the intangible assets and no impairment charge was recorded. During the same period, we also evaluated our goodwill for impairment and determined that the fair value of the reporting unit, estimated based on the market capitalization approach, was more than its carrying value and no impairment charge was recorded.

Interest income and expenses

Interest income was primarily related to interest earned from cash and cash equivalents. The decrease in interest income for fiscal year 2015 as compared to fiscal year 2014 was primarily due to decrease in average interest rate. The increase in interest income for fiscal year 2014 as compared to fiscal year 2013 was primarily due to increase in average cash balances.

Interest expense was primarily related to bank borrowings. The decrease in interest expenses since fiscal year 2013 was primarily due to decreases in bank borrowings related to the $20.0 million term loan obtained in May 2012 for our Oregon fab. The term loan was fully repaid in May 2015.

Income tax expense

Fiscal 2015 vs 2014

Income tax expense for fiscal years 2015 and 2014 was $4.1 million and $3.0 million , respectively. Income tax expense increased by $1.1 million , or 36.9% , in fiscal year 2015 as compared to fiscal year 2014 primarily due to the changes in the mix of earnings in various geographic jurisdictions as well as a decrease in the recognition of previously unrecognized tax benefits following the lapse of the applicable statue of limitations between the respective periods.

Fiscal 2014 vs 2013

Income tax expense for fiscal years 2014 and 2013 was $3.0 million and $4.0 million, respectively. Income tax expense decreased by $1.0 million, or 25.7%, in fiscal year 2014 as compared to fiscal year 2013 primarily due to a reduction in our uncertain tax positions offset partially by a change in the mix of earnings in various geographic jurisdictions.

Liquidity and Capital Resources

Our principal need for liquidity and capital resources is to maintain sufficient working capital to support our operations and to invest adequate capital expenditures to fuel the growth of our business. Currently, we primarily financed our operations and capital expenditures through funds generated from operations.

On May 11, 2012, we entered into a loan agreement with a financial institution that provides a term loan of $20.0 million for general purposes and a $10.0 million non-revolving credit line for the purchase of equipment. Both the term loan and equipment credit line was fully repayable in May 2015. The borrowings may be made in the form of either Eurodollar loans or Base Rate loans. Eurodollar loans accrued interest based on an adjusted London Interbank Offer Rate ("LIBOR") as defined in the agreement, plus a margin of 1.00% to 1.75% . Base Rate loans accrued interest at the highest of (a) the lender's Prime Rate, (b) the Federal Funds Rate plus 0.5% and (c) the Eurodollar Rate (for a one-month interest period) plus 1% ; plus a margin of -0.5% to 0.25% . The applicable margins for both Eurodollar loans and Base Rate loans varied from time to time in the foregoing ranges based on the cash and cash equivalent balances maintained by us and our subsidiaries with the lender. In May 2013, the equipment credit line expired and there was no outstanding balance. In May 2015, we repaid the term loan in full and there was no outstanding balance as at June 30, 2015.

The obligations under the loan agreement were secured by substantially all assets of two of our subsidiaries, including but not limited to, certain real property and related assets located at the Oregon fab. In addition, we and certain of our subsidiaries had agreed to guarantee full repayment and performance of the obligations under the loan agreement. The loan agreement contained customary restrictive covenants and included certain financial covenants that required us to maintain on a consolidated basis specified financial ratios including total liabilities to tangible net worth, fixed charge coverage and current assets to current liabilities. We were in compliance with these covenants in the fiscal year 2015 and 2014.

During July 2012, we entered into a loan agreement with the State of Oregon for an amount of $0.3 million. The loan was required to be used for training new and re-training existing employees of the Oregon fab. The loan bore a compound annual interest rate of 5.0% and was to be repaid in April 2014 if the required conditions were not met. In September 2014, the State of Oregon forgave the outstanding balance in full as we had satisfied the conditions. The $0.3 million loan forgiven was recorded as a reduction of costs of goods sold in our condensed consolidated statements of operations.

Our Board of Directors periodically considers various options to utilize our cash reserve to enhance the value of our shareholders. On May 8, 2014, our Board of Directors approved to reactivate our $25.0 million share repurchase program which was originally authorized on October 22, 2010. The Board authorized management to repurchase, subject to oversight by the Board, our common shares up to the remaining balance of the program, or $22.7 million. In April 2015, our Board of Directors of the Company approved an increase in the remaining available amount under the Company's share repurchase program from approximately $17.8 million to $50.0 million . The repurchases were made from the open market pursuant to a pre-establised Rule 10b5-1 trading plan (as amended, the "Repurchase Trading Plan") or through privately negotiated transactions. The amount and timing of any repuchases depend on a number of factors, including but not limited to, the trading price, volume and availability of our common shares, applicable legal requirements, our business and financial conditions an general market environment. There is no guarantee that any repurchases under the Program will be made or that such repurchases would enhance the value of our shares. During fiscal year 2015 we repurchased an aggregate of 666,230 shares from the open market under the Repurchase Trading Plan for a total cost of $5.8 million, at an average price of $8.70 per share. As of June 30, 2015 , we repurchased an aggregate of 1,027,594 shares from the open market under the Repurchase Trading Plan for a total cost of $9.0 million , at an average price of $8.74 per share, since inception of the program. Shares repurchased are accounted for as treasury shares and the

total cost of shares repurchased is recorded as a reduction of shareholders' equity. As of June 30, 2015 , of the 1,027,594 repurchased shares, 29,675 shares with a weighted average repurchase price of $13.84 per share, were reissued at an average price of $2.19 per share for option exercises and vested restricted share units.    

In June 2015, we commenced a modified Dutch auction tender offer (the "Tender Offer") to repurchase an aggregate of $30.0 million of our outstanding common shares with a price range between $8.50 and $9.20 per share. In July 2015, we completed the Tender Offer in which we purchased 3,296,703 shares of its common shares, at a purchase price of $9.10 per share, for an aggregate purchase price of $30.0 million, excluding fees and expenses relating to the Tender Offer. These shares represent approximately 12.53% of the total number of the Company's common shares issued and outstanding as of June 30, 2015. The Tender Offer was part of the $50.0 million share repurchase program approved by the Board in April 15, 2015. Immediately following the completion of the Tender Offer, approximately $18.2 million remained available under the share repurchase program.

The Chinese government imposes certain currency exchange controls on cash transfers out of China. Regulations in China permit foreign owned entities to freely convert the Renminbi into foreign currency for transactions that fall under the "current account," which includes trade related receipts and payments, and interests. Accordingly, our Chinese subsidiaries may use Renminbi to purchase foreign exchange currency for settlement of such "current account" transactions without pre-approval.

Other transactions that involve conversion of Renminbi into foreign currency are classified as "capital account" transactions. Examples of "capital account" transactions include repatriations of investments by or dividends to foreign owners. Pursuant to applicable regulations, foreign-invested enterprises in China may pay dividends only out of their accumulated profits, if any, determined in accordance with Chinese accounting standards and regulations. In calculating accumulated profits, foreign investment enterprises in China are required to allocate at least 10% of their profits each year, if any, to fund the equity reserve account unless the reserve has reached 50% of the registered capital of the enterprises. "Capital account" transactions require prior approval from China's State Administration of Foreign Exchange (SAFE) or its provincial branch to convert a remittance into a foreign currency, such as U.S. dollars, and transmit the foreign currency outside of China. As a result of this and other restrictions under PRC laws and regulations, our China subsidiaries are restricted in their ability to transfer a portion of their net assets to the parent.  As of June 30, 2015 and 2014 , such restricted portion amounted to approximately $86.8 million and $85.6 million, or 31.4% and 30.3% , of our total consolidated net assets, respectively.

We believe that our current cash and cash equivalents and cash flows from operations will be sufficient to meet our anticipated cash needs, including working capital and capital expenditures, for at least the next twelve months. In the long-term, we may require additional capital due to changing business conditions or other future developments, including any investments or acquisitions we may decide to pursue. If our cash is insufficient to meet our needs, we may seek to raise capital through equity or debt financing. The sale of additional equity securities could result in dilution to our shareholders. The incurrence of indebtedness would result in increased debt service obligations and may include operating and financial covenants that would restrict our operations. We cannot be certain that any financing will be available in the amounts we need or on terms acceptable to us, if at all.

Cash and cash equivalents

As of June 30, 2015 and 2014 , we had $106.1 million and $117.8 million of cash and cash equivalents, respectively. Our cash and cash equivalents primarily consist of cash on hand and short-term bank deposits with original maturities of three months or less. Of the $106.1 million and $117.8 million cash and cash equivalents, $60.0 million and $77.0 million, respectively, are deposited with financial institutions outside the United States.

The following table shows our cash flows from operating, investing and financing activities for the periods indicated:

Cash flows from operating activities

Net cash provided by operating activities of $27.1 million for fiscal year 2015 resulted primarily from net loss of $7.9 million , non-cash charges of $32.6 million and net change in assets and liabilities providing net cash of $2.4 million . The non-cash charges of $32.6 million included depreciation and amortization expenses of $27.5 million , share-based compensation expense of $4.5 million , and net deferred income taxes of $1.0 million , partially offset by a $0.3 million of forgiveness of the loan from the State of Oregon and a $0.1 million of gain on disposal of property and equipment during the fiscal year 2015 . The net change in assets and liabilities providing net cash of $2.4 million was primarily due to $2.4 million decrease in inventories as we reduced our inventories, $3.3 million increase in accounts payable primarily due to timing of payment, and 0.7 million increase in accrued and other liabilities, partially offset by $2.2 million increase in accounts receivable due to the timing of billings and collection of payments, $1.3 million decrease in income taxes payable, and $0.5 million increase in other current and long-term assets primarily due to increase in advance payments to suppliers.

Net cash provided by operating activities of $37.6 million for fiscal year 2014 resulted primarily from net loss of $3.3 million, non-cash charges of $31.5 million and net change in assets and liabilities providing net cash of $9.4 million. The non-cash charges of $31.5 million included depreciation and amortization expenses of $27.9 million, share-based compensation expense of $3.4 million, and net deferred income taxes of $0.8 million, partially offset by allowance for doubtful account of $0.4 million and gain on disposal of property and equipment of $0.2 million during the fiscal year 2014. The net change in assets and liabilities providing net cash of $9.4 million was primarily due to $1.8 million decrease in inventories as we reduced our inventories, $2.1 million decrease in accounts receivable due to the timing of billings and collection of payments, $5.5 million increase in accounts payable primarily due to increase in inventory purchase and timing of payment, and $2.4 million increase in accrued and other liabilities primarily related to employee compensation and performance bonuses, partially offset by $0.9 million decrease in income taxes payable, and $1.4 million increase in other current and long-term assets primarily due to increase in advance payments to suppliers.

Net cash provided by operating activities of $28.0 million for fiscal year 2013 resulted primarily from net loss of $5.6 million, non-cash charges of $37.8 million and net change in assets and liabilities using net cash of $4.2 million. The non-cash charges of $37.8 million included $29.4 million in depreciation and amortization expenses, $4.8 million in share-based compensation expense, $1.0 million in net deferred income taxes, and $2.6 million in impairment charges of long-lived assets during the third quarter. The net change in assets and liabilities using net cash of $4.2 million was primarily due to $0.7 million decrease in income taxes payable, $2.6 million increase in inventories as we built up our inventories for the Oregon fab ramp up, and $5.4 million decrease in accrued and other liabilities primarily related to payment of performance bonuses, partially offset by $0.6 million decrease in accounts receivable due to the timing of billings and collection of payments, $1.8 million increase in accounts payable primarily due to increase in inventory purchase and timing of payment, and $2.1 million decrease in other current and long-term assets primarily due to decrease in advance payments to suppliers.

Cash flows from investing activities

Net cash used in investing activities of $21.3 million for the fiscal year 2015 was primarily attributable to $21.5 million purchase of property and equipment to increase our in-house production capacity, partially offset by $0.3 million proceeds from sale of certain equipment.

Net cash used in investing activities of $9.2 million for the fiscal year 2014 was primarily attributable to $9.4 million purchase of property and equipment to increase our in-house production capacity, partially offset by $0.2 million proceeds from sale of certain equipment.

Net cash used in investing activities of $17.3 million for the fiscal year 2013 was primarily attributable to $17.6 million purchase of property and equipment to increase our in-house production capacity, partially offset by $0.3 million proceeds from sale of certain equipment.

Cash flows from financing activities

Net cash used in financing activities of $17.4 million for the fiscal year 2015 was primarily attributable to $13.6 million of repayment to our borrowings, $5.8 million for repurchase of our common shares under the repurchase program, and $1.1 million in payment of capital lease obligations; partially offset by a $3.0 million of proceeds from exercises of share options and issuance of shares under the ESPP.

Net cash used in financing activities of $3.1 million for the fiscal year 2014 was primarily attributable to $3.6 million of repayment to our borrowings, $1.0 million for repurchase of our common shares under the repurchase program, and $1.3 million in payment of capital lease obligations; partially offset by a $2.7 million of proceeds from exercises of share options and issuance of shares under the ESPP.

Net cash used in financing activities of $0.5 million for the fiscal year 2013 was primarily attributable to $2.6 million of net repayment to our borrowings and $1.0 million in payment of capital lease obligations; partially offset by a $3.1 million of proceeds from exercises of share options and issuance of shares under the ESPP.

Contractual Obligations

Our contractual obligations as of June 30, 2015 are as follows:

As of June 30, 2015 , we had recorded liabilities of $1.4 million for uncertain tax positions and $0.2 million for potential interest and penalties, which are not included in the above table because we are unable to reliably estimate the amount of payments in individual years that would be made in connection with these uncertain tax positions.

Off-Balance Sheet Arrangements

As of June 30, 2015 , we had no material off-balance sheet arrangements as defined in Item 303(a)(4)(ii) of Regulation S-K.

Critical Accounting Policies and Estimates

The preparation of our consolidated financial statements requires us to make estimates, judgments and assumptions that affect the reported amounts of assets, liabilities, revenue and expenses. To the extent there are material differences between these estimates and actual results, our consolidated financial statements will be affected. On an ongoing basis, we evaluate the estimates, judgments and assumptions including those related to revenue recognition, inventory reserves, warranty accrual, income taxes, share-based compensation, and useful lives for property and equipment and for goodwill and intangible assets.

Revenue recognition

We recognize revenue when there is persuasive evidence that an arrangement exists, delivery has occurred, the price to the buyer is fixed or determinable and when collectability is reasonably assured. We recognize revenue when product is shipped to the customer, net of estimated stock rotation returns and price adjustments to certain distributors.

We sell our products primarily to distributors, who in turn sell our products globally to various end customers. Our revenue is net of the effect of the estimated stock rotation returns and price adjustments that we expect to provide to certain distributors. Stock rotation returns are governed by contract and are limited to a specified percentage of the monetary value of the products purchased by distributors during a specified period. We estimate provision for stock rotation returns based on historical returns and individual distributor agreements. We also provide special pricing to certain distributors primarily based on volume, to encourage resale of our products. We estimate the expected price adjustments at the time the revenue is recognized based on distributor inventory levels, pre-approved future distributor selling prices, distributor margins and demand for our products. If actual stock rotation returns or price adjustments differ from our estimates, adjustments may be recorded in the period when such actual information is known. Allowance for price adjustments is recorded against accounts receivable and provision for stock rotation is recorded in accrued liabilities on the consolidated balance sheets.

Revenue from certain distributors is deferred until the distributor resells the products to end customers due to price protection adjustments and right of returns that cannot be reliably measured. The deferred revenue, net of the associated deferred cost of the inventory, is recorded as deferred margin on the consolidated balance sheets.

Packaging and testing services revenue is recognized upon shipment of serviced products to the customer.

Inventory reserves

We carry inventories at the lower of cost (determined on a first-in, first-out basis) or market value. Cost primarily consists of semiconductor wafers and raw materials, labor, depreciation expenses and other manufacturing expenses and overhead, and packaging and testing fees paid to third parties if subcontractors are used. Inventory reserves are made based on our periodic review of inventory quantities on hand as compared with our sales forecasts, historical usage, aging of inventories, production yield levels and current product selling prices. If actual market conditions are less favorable than those forecasted by us, additional future inventory write-downs may be required that could adversely affect our operating results. Inventory reserves once established are not reversed until the related inventory has been sold or scrapped. If actual market conditions are more favorable than expected and the products that have previously been written down are sold, our gross margin would be favorably impacted.

Product warranty

We provide a standard one-year warranty for the products we sell. We accrue for estimated warranty costs at the time revenue is recognized. Our warranty obligation is affected by product failure rates, labor and material costs for replacing defective parts, related freight costs for failed parts and other quality assurance costs. We monitor our product returns for warranty claims and maintain warranty reserve based on our historical experiences and anticipated warranty claims known at the time of estimation. If actual warranty costs differ significantly from our estimates, revisions to the estimated warranty accrual would be required and any such adjustments could be material.

Accounting for income taxes

We are subject to income taxes in a number of jurisdictions. We must make certain estimates and judgments in determining income tax expense for financial statement purposes. These estimates and judgments occur in the calculation of tax credits, benefits and deductions, and in the calculation of certain tax assets and liabilities which arise from differences in the timing of recognition of revenue and expense for tax and financial statement purposes, as well as interest and penalties related to uncertain tax positions. There are many transactions and calculations for which the ultimate tax determination is uncertain during the ordinary course of business. We establish accruals for certain tax contingencies based on estimates of whether additional taxes may be due. While the final tax outcome of these matters may differ from the amounts that were initially recorded, such differences will impact the income tax and deferred tax provisions in the period in which such determination is made.  As a result, significant changes to these estimates may result in an increase or decrease to our tax provision in a subsequent period.

Significant management judgment is also required in determining whether deferred tax assets will be realized in full or in part. When it is more likely than not that all or some portion of specific deferred tax assets such as net operating losses or foreign tax credit carryforwards will not be realized, a valuation allowance must be established for the amount of the deferred tax assets that cannot be realized. We consider all available positive and negative evidence on a jurisdiction-by-jurisdiction basis when assessing whether it is more likely than not that deferred tax assets are recoverable. We consider evidence such as our past operating results, the existence of cumulative losses in recent years and our forecast of future taxable income. We intend to maintain a partial valuation allowance equal to the state research and development credit carryfowards until sufficient positive evidence exists to support reversal of the valuation allowance.

We have not provided for withholding taxes on the undistributed earnings of our foreign subsidiaries because we intend to reinvest such earnings indefinitely. As of June 30, 2015 , the cumulative amount of undistributed earnings of our foreign subsidiaries considered permanently reinvested was $67.1 million . The determination of the unrecognized deferred tax liability on these earnings is not practicable. Should we decide to remit this income to the Bermuda parent company in a future period, our provision for income taxes may increase materially in that period.

The Financial Accounting Standards Board, or FASB, has issued guidance which clarifies the accounting for income taxes by prescribing a minimum probability threshold that a tax position must meet before a financial statement benefit is recognized. The minimum threshold is defined as a tax position that is more likely than not to be sustained upon examination by the applicable taxing authority, including resolution of any related appeals or litigation processes, based on the technical merits of

the position. The tax benefit to be recognized is measured as the largest amount of benefit that is greater than fifty percent likely to be realized upon ultimate settlement. The calculation of our tax liabilities involves dealing with uncertainties in the application of complex tax law and regulations in a multitude of jurisdictions. Although the guidance on the accounting for uncertainty in income taxes prescribes the use of a recognition and measurement model, the determination of whether an uncertain tax position has met those thresholds will continue to require significant judgment by management. If the ultimate resolution of tax uncertainties is different from what is currently estimated, a material impact on income tax expense could result.

Our provision for income taxes is subject to volatility and could be adversely impacted by changes in earnings or tax laws and regulations in various jurisdictions. We are subject to the continuous examination of our income tax returns by the Internal Revenue Service and other tax authorities. We regularly assess the likelihood of adverse outcomes resulting from these examinations to determine the adequacy of our provision for income taxes. There can be no assurance that the outcomes from these continuous examinations will not have an adverse effect on our operating results and financial condition. To the extent that the final tax outcome of these matters is different than the amounts recorded, such differences will impact the provision for income taxes in the period in which such determination is made. The provision for income taxes includes the impact of changes to reserves, as well as the related net interest and penalties.

Share-based compensation expense

We recognize share-based compensation expense based on the estimated fair value of the awards determined by the Black-Scholes option valuation model, using the accelerated vesting attribution method. Share-based compensation expense is significant to the consolidated financial statements and is calculated using our best estimates, which involve inherent uncertainties and the application of management's judgment.

We determined the weighted average valuation assumptions as follows:

Estimated Useful Lives for Property, Plant and Equipment and Intangible Assets

Property, plant and equipment are recorded at cost and are depreciated using the straight-line method over estimated useful lives of the assets. Patents and exclusive technology rights purchased from third parties are amortized on a straight-line basis over their estimated useful lives of three to seven years. Trade name and customer relationships acquired in a business combination are recognized at fair values at the acquisition date and amortized on a straight-line basis over their estimated economic lives of three years and four years, respectively.

Goodwill

Goodwill and intangible assets with indefinite useful lives are not amortized, but are tested for impairment at least annually, or whenever changes in circumstances indicate that the carrying amount of goodwill or intangible assets may not be recoverable. These tests are performed at the reporting unit level using a two-step, fair-value based approach. In testing for a potential impairment of goodwill, we first compare the carrying value of assets and liabilities to the estimated fair value. If estimated fair value is less than carrying value, then potential impairment exists. The amount of any impairment is then

calculated by determining the implied fair value of goodwill using a hypothetical purchase price allocation, similar to that which would be applied if it were an acquisition and the purchase price was equivalent to fair value as calculated in the first step. Impairment is equivalent to any excess of goodwill carrying value over its implied fair value. The process of evaluating the potential impairment of goodwill requires significant judgment at many points during the analysis, including calculating fair value of each reporting unit based on estimated future cash flows and discount rates to be applied.

Recently Issued Accounting Pronouncements

See Note 1 of the Notes to the consolidated financial statements under Item 15 in this Annual Report on Form 10-K for a full description of recent accounting pronouncements, including the expected dates of adoption and estimated effects on results of operations and financial condition.

Foreign currency risk

We and our principal subsidiaries use U.S. dollars as our functional currency because most of the transactions are conducted and settled in U.S. dollars. All of our revenue and a significant portion of our operating expenses are denominated in U.S. dollars. The functional currency for our in-house packaging and testing facilities in China is U.S. dollars and a significant portion of our capital expenditures are denominated in U.S. dollars. However, foreign currencies are required to fund our overseas operations, primarily in Taiwan and China. Operating expenses of overseas operations are denominated in their respective local currencies. In order to minimize exposure to foreign currencies, we maintained cash and cash equivalent balances in foreign currencies, including Chinese Yuan ("RMB") as operating funds for our foreign operating expenses. Our management believes that our exposure to foreign currency translation risk is not significant based on a 10% sensitivity analysis in foreign currencies due to the fact that the net assets denominated in foreign currencies pertaining to foreign operations, principally in Taiwan and China, are not significant to our consolidated net assets.

Interest rate risk

Our interest-bearing assets comprise mainly interest-bearing short-term bank balances. We manage our interest rate risk by placing such balances in instruments with various short-term maturities. Borrowings expose us to interest rate risk. Borrowings are drawn down after due consideration of market conditions and expectation of future interest rate movements. In the past, our borrowings have been subject to floating interest rates, and future borrowings may expose us to cash-flow interest rate risk. We had no outstanding borrowings at June 30, 2015 as the term loan was repaid in full in May 2015.

Commodity Price Risk

We are subject to risk from fluctuating market prices of certain commodity raw materials, particularly gold, that are used in our manufacturing process and incorporated into our end products. Supplies for such commodities may from time-to-time become restricted, or general market factors and conditions may affect the pricing of such commodities. Over the past few years, the price of gold increased significantly and certain of our supply chain partners assess surcharges to compensate for the rising commodity prices. We have been converting some of our products to use copper wires instead of gold wires. Our results of operations may be materially and adversely affected if we have difficulty obtaining these raw materials, the quality of available raw materials deteriorates, or there are significant price changes for these raw materials. For periods in which the prices of these raw materials are rising, we may be unable to pass on the increased cost to our customers which would result in decreased margins for the products in which they are used and could have a material adverse effect on our net earnings. We also may need to record losses for adverse purchase commitments for these materials in periods of declining prices. We do not enter into formal hedging arrangements to mitigate against commodity risk. We estimate that a 10% increase or decrease in the costs of raw materials subject to commodity price risk, such as gold, would decrease or increase our current year's net earnings by $0.9 million, assuming that such changes in our costs have no impact on the selling prices of our products and that we have no pending commitments to purchase metals at fixed prices.

See Part IV, Item 15 "Exhibits and Financial Statement Schedules" for our consolidated financial statements and the notes and schedules thereto filed as part of this annual report.

Selected Quarterly Consolidated Financial Data

The following tables present our unaudited consolidated financial information for each of the eight quarters in the period ended June 30, 2015 . Net income per share for the four quarters of each fiscal year may not sum to the total for the fiscal year because of difference in the number of shares outstanding during each period. The operating results for any quarter should not be relied upon as necessarily indicative of results for any future period. We expect our quarterly operating results to fluctuate in future periods due to a variety of reasons, including those discussed in Item 1A. "Risk Factors."

Not applicable.

Evaluation of Disclosure Controls and Procedures

Our management, with the participation of our Chief Executive Officer and Chief Financial Officer, evaluated the effectiveness of our disclosure controls and procedures (as defined in Rules 13a-15(e) and 15d-15(e) under the Securities Exchange Act of 1934, as amended, (the "Exchange Act")), as of the end of the period covered by this report. Based on that evaluation, the Chief Executive Officer and Chief Financial Officer concluded that our disclosure controls and procedures as of June 30, 2015 have been designed and are functioning effectively to provide reasonable assurance that the information required to be disclosed in the reports that we file or submit under the Exchange Act is recorded, processed, summarized and reported, within the time periods specified in the SEC's rules and forms, and that such information is accumulated and communicated to our management, including our Chief Executive Officer and Chief Financial Officer, or persons performing similar functions, as appropriate to allow timely decisions regarding required disclosure.

Management's Annual Report on Internal Control over Financial Reporting

Our management, including our Chief Executive Officer and Chief Financial Officer, is responsible for establishing and maintaining adequate internal control over financial reporting, as such term is defined in Exchange Act Rule 13a-15(f) and Rule 15d-15(f). Our internal control over financial reporting is a process designed to provide reasonable assurance regarding the reliability of financial reporting and the preparation of our financial statements for external purposes in accordance with generally accepted accounting principles, and includes those policies and procedures that (1) pertain to the maintenance of records that, in reasonable detail, accurately and fairly reflect the transactions and dispositions of our assets; (2) provide reasonable assurance that transactions are recorded to permit preparation of financial statements in accordance with generally accepted accounting principles, and that our receipts and expenditures are made only in accordance with authorizations of our management and directors; and (3) provide reasonable assurance regarding prevention or timely detection of unauthorized acquisition, use or disposition of our assets that could have a material effect on our financial statements.

On May 14, 2013, the Committee of Sponsoring Organizations of the Treadway Commission (COSO) issued an updated version of its Internal Control - Integrated Framework, referred to as the 2013 COSO Framework and has indicated that after December 15, 2014, the 1992 Framework would be considered superseded. The 2013 Framework helps organizations design and implement internal control in light of many changes in business and operating environments since the issuance of the original Framework, broadens the application of internal control in addressing operations and reporting objectives, and clarifies the requirements for determining what constitutes effective internal control. The 2013 Framework was adopted in the quarter ended December 31, 2014. Our management, including our Chief Executive Officer and Chief Financial Officer, assessed the effectiveness of our internal control over financial reporting, and has concluded that, as of June 30, 2015 , our internal control over financial reporting was effective.

The effectiveness of the Company's internal control over financial reporting as of June 30, 2015 has been audited by Grant Thornton LLP, an independent registered public accounting firm, as stated in their report, included on the following page.

Limitation on the Effectiveness of Controls    

While our disclosure controls and procedures and internal control over financial reporting are designed to provide reasonable assurance that their respective objectives will be met, we do not expect that our disclosure controls and procedures or our internal control over financial reporting are or will be capable of preventing or detecting all errors and all fraud. Any control system, no matter how well designed and operated, can provide only reasonable, not absolute, assurance that the control system's objectives will be met.

Changes in Internal Control Over Financial Reporting

There were no changes in our internal control over financial reporting that occurred during the quarter ended June 30, 2015 that have materially affected or are reasonably likely to materially affect, our internal control over financial reporting.

REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

Board of Directors and Stockholders

Alpha and Omega Semiconductor Limited

We have audited the internal control over financial reporting of Alpha and Omega Semiconductor Limited (a Bermuda corporation) and subsidiaries (the "Company") as of June 30, 2015, based on criteria established in the 2013 Internal Control-Integrated Framework issued by the Committee of Sponsoring Organizations of the Treadway Commission (COSO). The Company's management is responsible for maintaining effective internal control over financial reporting and for its assessment of the effectiveness of internal control over financial reporting, included in the accompanying Management's Annual Report on Internal Control over Financial Reporting. Our responsibility is to express an opinion on the Company's internal control over financial reporting based on our audit.

We conducted our audit in accordance with the standards of the Public Company Accounting Oversight Board (United States). Those standards require that we plan and perform the audit to obtain reasonable assurance about whether effective internal control over financial reporting was maintained in all material respects. Our audit included obtaining an understanding of internal control over financial reporting, assessing the risk that a material weakness exists, testing and evaluating the design and operating effectiveness of internal control based on the assessed risk, and performing such other procedures as we considered necessary in the circumstances. We believe that our audit provides a reasonable basis for our opinion.

A company's internal control over financial reporting is a process designed to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles. A company's internal control over financial reporting includes those policies and procedures that (1) pertain to the maintenance of records that, in reasonable detail, accurately and fairly reflect the transactions and dispositions of the assets of the company; (2) provide reasonable assurance that transactions are recorded as necessary to permit preparation of financial statements in accordance with generally accepted accounting principles, and that receipts and expenditures of the company are being made only in accordance with authorizations of management and directors of the company; and (3) provide reasonable assurance regarding prevention or timely detection of unauthorized acquisition, use, or disposition of the company's assets that could have a material effect on the financial statements.

Because of its inherent limitations, internal control over financial reporting may not prevent or detect misstatements. Also, projections of any evaluation of effectiveness to future periods are subject to the risk that controls may become inadequate because of changes in conditions, or that the degree of compliance with the policies or procedures may deteriorate.

In our opinion, Alpha and Omega Semiconductor Limited and subsidiaries maintained, in all material respects, effective internal control over financial reporting as of June 30, 2015, based on criteria established in the 2013 Internal Control-Integrated Framework issued by COSO.

We also have audited, in accordance with the standards of the Public Company Accounting Oversight Board (United States), the consolidated financial statements of the Company as of and for the year ended June 30, 2015, and our report dated August 27, 2015 expressed an unqualified opinion on those consolidated financial statements and schedules.

/s/ GRANT THORNTON LLP

San Francisco, California

August 27, 2015

None

PART III

Certain information required by Part III is omitted from this Annual Report on Form 10-K because we intend to file our definitive proxy statement for our next annual meeting of shareholders, pursuant to Regulation 14A of the Securities Exchange Act of 1934, as amended (the " 2015 Proxy Statement"), no later than 120 days after the end of fiscal year 2015 , and certain information to be included in the 2015 Proxy Statement is incorporated herein by reference.

The information required by this item concerning our directors, executive officers, Section 16 compliance and corporate governance matters is contained in part under the caption "Business - Executive Officers" in Part I of this report, and the remainder is incorporated by reference to the information set forth in the sections titled "Election of Directors" and "Section 16(a) Beneficial Ownership Reporting Compliance" in the 2015 Proxy Statement.

The information required by this item regarding executive compensation is incorporated by reference from the information set forth under the captions "Compensation of Non-Employee Directors" and "Executive Compensation," in the 2015 Proxy Statement.

The information required by this item regarding security ownership of certain beneficial owners and management is incorporated by reference to the information set forth in the section titled "Security Ownership of Certain Beneficial Owners and Management" and "Equity Compensation Plan Information" in the 2015 Proxy Statement.