ALPHA & OMEGA SEMICONDUCTOR Ltd (AOSL) Business

Item 1.Business

Forward Looking Statements

This Annual Report on Form 10-K and the documents incorporated herein by reference contain 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 2,800 products, and has grown with the introduction of over 100 new products in the fiscal year ended June 30, 2025, and over 100 and 60 new products in the fiscal years ended June 30, 2024 and 2023, respectively. 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 949 issued patents and 64 pending patents in the United States as of June 30, 2025. We also have a total of 961 foreign patents, which were based primarily on our research and development efforts through June 30, 2025. 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, graphic cards, game consoles, home appliances, power tools, smart phones, battery packs, consumer and industrial motor controls and power supplies for computers, servers and telecommunications equipment.

During the fiscal year ended June 30, 2025, we continued our diversification strategy 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, Insulated Gate Bipolar Transistors, or IGBTs and integrated power modules for the home appliance market, as well as power integrated circuits (“ICs”) for personal computing (“PC ”), advanced computing and gaming 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. We operate an 8-inch 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. 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 provide us with a competitive advantage in proprietary packaging technology, product quality, cost and sales cycle time.

As of June 30, 2025, we owned approximately 39.2% of outstanding equity interest in a joint venture company (the “JV Company”) that operates a power semiconductor packaging, testing and 12-inch wafer fabrication facility (“Fab”, “Chongqing Fab” ) in the LiangJiang New Area of Chongqing, China, and the JV Company is an important supplier of wafers and assembly and test services to us. On December 30, 2024, the JV Company signed an investment agreement with an investor, pursuant to which the investor agreed to invest RMB 500 million (or $68.5 million based on the currency exchange rate between RMB and

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U.S. Dollar on December 31, 2024) in the JV Company in exchange for a 7.09% interest. This transaction closed on January 15, 2025, at which time, the percentage of outstanding JV Company’s equity interest owned by the Company was reduced to approximately 39.2%. We recorded a gain of $0.5 million on the change of equity interest in the JV Company, which was included in the equity method investment loss line in the consolidated statements of operations. The funding of the investment was agreed to be made in three installments. The JV Company received the first installment of RMB 40 million (or $5.5 million) on December 31, 2024. However, the JV Company has not received the remaining two installments as of the filing date.

On July 14, 2025, we entered into an equity transfer agreement (“Agreement”) with the investor to sell approximately 20.3% of outstanding equity interest in the JV Company for an aggregate cash consideration of $150 million. We identified the negotiations of the equity transfer agreement throughout the fourth quarter of fiscal year 2025 as an impairment indicator and performed a quantitative impairment test as of June 30, 2025. Based on the implied valuation of the JV Company per the transaction price in the equity transfer agreement, the fair value of the equity method investment was determined to be lower than its carrying value, and a $76.8 million other-than-temporary impairment of the equity method investment was recognized as of June 30, 2025. We believe this sale will provide additional and significant capital for us to continue investment in technology, research and development projects and acquisition of assets complimentary to our business operations, which will facilitate and accelerate our efforts to develop and distribute innovative and diverse power semiconductor products to customers worldwide. In addition, the JV Company will continue to provide us with a significant level of foundry capacity to enable us to develop and manufacture our products. Pursuant to an agreement with the JV Company and other shareholders of the JV Company, the JV Company is committed to provide us with a specified level of monthly wafer production capacity.

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. 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. Regulations governing energy efficiency have accelerated this process in many applications.

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 products. Once designed into an application, the analog portion is rarely modified because even small changes to the analog portion can trigger unanticipated consequences in 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 system 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 discrete devices is power delivery by switching, transferring or converting electricity.  Power transistors comprise the largest portion of the power discrete device 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 discrete devices.

The power semiconductor market has been driven by several key factors in recent years. The proliferation of computer and consumer electronics, such as notebooks, tablets, smart phones, and portable media players created the need for sophisticated power management that increases power efficiency and extends battery life. The evolution of these products is characterized by increased functionality, thinner and smaller form factors and decreasing prices. Our Power IC and low voltage

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(5V-40V) MOSFET products address these markets. 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 drives the market 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 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 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, advancements in semiconductor packaging technology enable increased power density and shrinking form factors.

Our business and operational model is based on achieving a balance between technological advancement and cost effectiveness by using a dedicated in-house technology research and development team to drive rapid new product developments, while utilizing both in-house and third-party foundry capacity for our products. This is particularly important in the development of power semiconductor products due to the unique nature of their technology.

Our strategies

We seek to advance our position as a designer, developer and global supplier of a broad portfolio of power semiconductors. We have adopted strategies that allow us to balance the development of proprietary technology at in-house fabrication and packaging facilities and also utilize the capacity and manufacturing capability of third-party foundries and subcontractors. This enables us to bring new products to market faster, and improve our financial performance in the long run. This model also allows us to respond more quickly to our customer demands, enhances relationships with strategic customers, provides flexibility in capacity management, and enables geographic diversification of our supply chain. Our in-house manufacturing capability allows us to retain a higher level of control over the development and application of our proprietary process technology, thereby reducing certain supply chain and operational risks. In addition, we enhanced the manufacturing capability and capacity of our Oregon Fab by investing in new equipment and expanding factory facilities, which we expect will have a positive impact on our future new product development and revenue. We intend to continue exploring opportunities to expand our manufacturing capabilities, including acquisition of existing facilities, formation of joint ventures or partnerships with third parties or applying for government funding or grants available in the semiconductor industry.

Although our largest end-market is the Computing market, we have successfully diversified our business by expanding into other markets, including consumer, communications, and power supply and industrial markets. While we have made progress in our diversification and expansion into additional applications, we continue to support and grow our computing business by expanding bill-of-material content, gaining market share, acquiring new customers, and expanding into new application areas such as AI.

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 2,800 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, medium and low voltage MOSFETs, in order to broaden our addressable market and improve our margin profile. This includes expanding our power IC portfolio with multiphase controllers and smart power stages to address advanced System on Chip (SoC) products used in personal computing, AI, graphics cards, and gaming.

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 because of 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, including multiphase controller products to expand our product offerings and deliver complete power solutions for our targeted applications. In addition, our ability to develop new technology is enhanced by the operation of our own manufacturing facilities in Oregon and our close partnership with the JV Company.

Increase direct relationships and product penetration with OEM and ODM customers

We have developed direct relationships with key OEMs that are responsible for branding, designing and marketing a broad array of electronic products, as well as ODMs that have traditionally been responsible for manufacturing these products.

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We are also focusing on developing and solidifying relationships with certain Tier 1 customers, whose reputation, resources and market share may enable us to generate more significant sales and design wins, and we believe long-term relationships with Tier 1 customers will be a critical factor in our strategy to grow and expand our business operations. While OEMs typically focus design efforts on flagship products, ODMs are increasingly responsible for designing portions, or entire systems, of the products they manufacture for OEMs. In addition, several ODMs are beginning to design, manufacture and brand their own proprietary products which are sold 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, thereby increasing the number of our products used within their systems, and leveraging relationships to penetrate other products. In addition, we are focusing our research and development efforts to respond more directly to 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 will further expand and align our technical marketing and application support teams along with our sales team to better understand and address the needs of end customers and 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. While we no longer retain a controlling interest in the JV Company, we continue our strong relationship with the JV Company to support our manufacturing capacity. Also, we entered into an agreement with the JV Company, pursuant to which the JV Company agrees to provide us with a monthly wafer production capacity guarantee, subject to future increase when the JV Company’s production capacity reaches certain specified levels. In addition, we continue to seek potential partners and collaborators to develop new technologies and products, as well as to explore other strategic transactions that will enable us to expand our manufacturing capacity and establish a global footprint.

Our products

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

Our power discrete products consist of low, medium and high voltage power MOSFETs. Our low voltage MOSFET series is based on our proprietary silicon and package technologies, with deep application know-how in various markets. We have precisely defined technology platforms to address different requirements from various applications. Our medium voltage MOSFETs provide optimized performance with high efficiency, high robustness and high reliability, and are widely used in applications such as TV backlighting, telecom power supplies, and industrial applications. We expanded our high voltage 600V and 700V MOSFET portfolio based on our aMOS5 technology platform in order to address demanding consumer and industrial applications. Our high-voltage portfolio includes our proprietary IGBT technology, which we provide highly robust and easy-to-use solutions for industrial motor control and white goods applications. We have also deployed our 1200V SiC (Silicon carbide) products based on our AlphaSiC platform, designed to address high efficiency, high density industrial applications such as solar inverters, UPS, and battery management systems.

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. Our DrMOS and smart power stage (SPS) family of products continue to grow as we paired our latest high performance MOSFET silicon with our latest Driver IC and smart driver technologies. We continue to expand our EZBuck power IC family with products that feature lower on-resistance, less power consumption, smaller footprint and thermally enhanced packages as well. Our smart load switch products have expanded beyond basic load switched to include specialized applications like Type C and eFuse. Success has been driven by increased power density and protection to discrete solutions. Sale of power ICs continued to gain traction during the past years especially with the expansion of our driver and multiphase controller product lines. We introduced higher voltage drivers to expand success beyond PCs to motor drive applications such as power tools and garden equipment. We have also made a major investment in R&D to enter the multiphase controller market in 2020 with the introduction of the Intel IMVP 9.1 controller for notebooks. Since then, AOS has released or is designing in several multiphase controller families serving Intel, AMD and NVIDIA. Introduction of these multiphase controllers has enabled AOS to become a complete solution level provider, across multiple compute platforms from PCs, graphics cards to AI and datacenter.

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

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Power discrete products

Power discretes are used across a wide voltage and current spectrum, requiring high efficiency and reliability under harsh conditions. Due to the diverse nature of end-market applications, we market both general purpose MOSFETs that are used in multiple applications as well as application specific MOSFETs.

Our current power discrete product line includes industry standard trench MOSFETs, Shielded-Gate low voltage and mid-voltage MOSFETs, SuperJunction high voltage MOSFETs, and trench-stop IGBTs, as well as application specific MOSFETs for smartphone battery management, dual MOSFETs for CPU power conversion, and high-power density MOSFETs for IBC power modules in AI data centers.

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 product portfolios by interchanging only the MOSFETs without changing the power management IC, thereby reducing the time required for new product introduction and providing optimal solutions to our customers. 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 some of 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 our product families.

During the fourth quarter of fiscal year of 2025, we unveiled mega IPM-7 series intelligent power modules engineered to improve application performance and deliver increased power density. These new series are optimized for brushless DC (BLDC) motor drive-based designs, including home appliance applications such as air-conditioners, refrigerators, dishwashers, and power tools. We announced AOTL66935 utilizes AOS’ 100V AlphaSGT™ proprietary MOSFET technology which combines the advantages of trench technology for low on-resistance with high safe operating area (SOA) capability that meets 48V hot swap requirements in AI server and telecom applications. We introduced Gen3 1200V αSiC MOSFETs designed to maximize efficiency in high power applications. These Gen3 MOSFETs provide up to 30 percent improved switching figure-of-merit (FOM) compared to AOS’ previous generation while maintaining low conduction losses at high load conditions. We also introduced AMD SVI3 multiphase controller with low quiescent power for graphics and desktop systems. In addition, we introduced 25V MOSFET in DFN3.3x3.3 source-down packaging that meets power demands in AI servers. The source-down

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packaging technology offers a larger source contact to the PCB, and its center gate pin layout allows easier routing on the PCB, so the gate driver connection can be minimized.

During the third quarter of fiscal year of 2025, we unveiled a 16-phase controller that supports further AI server and graphic card innovation. This control scheme delivers a highly efficient, flexible power solution when paired with AOS' power stages. We also added two new advanced MOSFET package options for high-current applications. These devices provide low ohmic and high current capabilities, critical to reducing the number of parallel MOSFETs needed in high current designs such as in next-generation e-mobility and industrial applications.

During the second quarter of fiscal year of 2025, we announced our new application-specific EZBuck™ Regulator. The highly integrated, compact, and high-power-density AOZ23567QI constant on-time buck converter offers an upgraded solution that is designed to support VCCPRIM_VNNAON rails in the Intel Arrow Lake platform. Also, we unveiled our AOZ73004CQI, the world’s first 4-phase controller for blackwell GPUs. Its advanced design has received full OpenVReg (Open Voltage Regulator) OVR4-22 compliance.

During the first quarter of fiscal year of 2025, we announced new highly robust power MOSFET LFPAK 5x6 package for high performance and high-reliability requirements. It is designed to withstand harsh environments while maintaining MOSFET. In addition, we introduced an ideal diode protection switch with limited power source feature as a safeguard for multiport USB-C applications. The new device has advanced features that substantially reduce voltage drop and power loss compared to a discrete implementation.

Distributors and customers

We have established direct relationships with key OEMs, including Dell Inc., Hewlett-Packard Company, Samsung Group, and Stanley Black & Decker, Inc., most of whom we serve through our distributors and ODMs. In addition, based on our historical design win activities, our power semiconductors are also incorporated into products sold to many other leading 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, Wistron Corporation and Delta Electronics.

In order to take advantage of the expertise of end-customer fulfillment logistics and shorter payment cycles, we sell most of our products through distributors. In general, under our agreements with distributors, they have limited rights to return unsold merchandise, subject to time and volume limitations. As of June 30, 2025, 2024 and 2023, our two largest distributors were WPG Holdings Limited, or WPG, and Promate Electronic Co. Ltd., or Promate. Sales to WPG and Promate accounted for 51.3% and 22.1% of our revenue, respectively, for the fiscal year ended June 30, 2025, 46.0% and 25.0% of our revenue, respectively, for the fiscal year ended June 30, 2024, and 35.6% and 21.6% of our revenue, respectively, for fiscal year ended June 30, 2023, 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, field application engineers, or FAEs, for our new product offerings, providing real-time and local response to our end customers' needs. FAEs work with our end customers to understand their requirements and resolve technical problems. FAEs also 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 consists of sales personnel, 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, Qingdao, Suzhou, Tokyo, Seoul, Heilbronn, 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, creating additional demand and promoting our products, in which case we may pay a sales commission.

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Our sales cycle varies depending on the types of products and can range from six to eighteen months. In general, our power discrete products and Power IC products in Computing and Consumer segments progress more rapidly through the customer's design and marketing processes, and therefore they generally have a shorter sales cycle. In contrast, our IGBT and Module products, used mostly in the power supply, home appliance and industrial applications, require a more extended design and marketing timeline and thus have a longer sales cycle. Typically, our sales cycle for all products comprises the following steps:

•identification of a customer design opportunity;

•qualification of the design opportunity by our FAEs through comparison of the power requirements against our product portfolio;

•delivery of a product sample to the end customer to be included in the customer's pre-production model with the goal of being included in the final bill of materials; and

•placement by the customer, or through its distributor, of a full production order as the end customer transitions to full volume production.

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, China and Taiwan. Our major competitors in power discretes include Infineon Technologies AG, ON Semiconductor Corp., STMicroelectronics N.V., Toshiba Corporation, Diodes Incorporated and Vishay Intertechnology, Inc. Our major competitors for our power ICs include Monolithic Power Systems, Inc., ON Semiconductor Corp., Richtek Technology Corp., Semtech Corporation, Texas Instruments Inc. and Vishay Intertechnology, Inc.

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

•success in expanding and diversifying our serviceable markets, and our ability to develop technologies and product solutions for these markets;

•capability to quickly develop and introduce proprietary technology and best-in-class products;

•performance and cost-effectiveness of our products relative to that of our competitors;

•ability and capacity to manufacture, package and deliver products in large volume on a timely basis at a competitive price;

•success in utilizing new and proprietary technologies to offer products and features previously not available in the marketplace;

•ability to recruit and retain analog semiconductor designers and application engineers; and

•ability to protect our intellectual property.

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 strong and extensive patent portfolio, strategic global business model, expanding suites of new products, diversified and broad customer base, and excellent on-the-ground support and quick time to market for our products.

Seasonality

Our business is subject to seasonal fluctuations, primarily due to our involvement in the power semiconductor market for consumer electronic products. Sales seasonality is influenced by various factors, including global and regional economic conditions, trends within the personal computer (PC) market, revenue contributions from newly introduced products, variations in distributor ordering behavior driven by channel inventory adjustments, and end-customer demand. Additionally, fluctuations in consumer purchasing patterns—particularly leading up to major holiday seasons—also contribute to the seasonal nature of our revenue. Our revenue is subject to some seasonal variation. Historically, our sequential revenue growth rate tends to be weaker in the March and December quarters when compared with other quarters.

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Research and development

We view technology as a competitive advantage, and we invest significant time and capital in research and development to address the technology-intensive needs of our end customers. Our research and development expenditures for the fiscal years of 2025, 2024 and 2023 were $94.3 million, $89.9 million and $88.1 million, respectively. We continue to invest in developing new technologies and products utilizing our own fabrication and packaging facilities as it is critical to our long-term success. We also evaluate appropriate investment levels and stay focused on new product introductions to improve our competitiveness. We have research and development teams in Silicon Valley (Sunnyvale, California), Oregon, Texas, Arizona, Korea, Taiwan, and China. We believe that these diverse research and development teams enable 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 factors, and higher power output with efficient heat dissipation and cost-effectiveness. We have invested resources in developing and enhancing our proprietary packaging technologies, including the establishment of our in-house packaging and testing facilities. Our efforts to develop innovative packaging technologies continues to provide new and cost-effective solutions with higher power density to our customers. During the fiscal year ended June 30, 2025, we continued our diversification strategies by developing new silicon and packaging platforms to expand our SAM and offer higher performance 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, the Chongqing 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 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 within existing applications.

As a technology company, we will continue our significant investment in research and development in our low voltage, medium voltage, and high voltage power discretes, IGBT and power modules and power ICs by developing new technology platforms and new products that allow for improved product performance, higher efficiency 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 service to our customers. We allocate our wafer production between our in-house facility and third-party foundries. Currently wafers from our third-party accounts for around 30% of AOS’s total wafer supply.

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 and wholly-owned packaging and testing facilities are located in Shanghai, China which handle most of our packaging and testing requirements for our products. In addition, the JV Company handles a portion of our packaging and testing requirement. We continuously increase the outsourcing portion of our packaging and testing requirements to other

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contract manufacturers to improve our ability to respond to changes in market demand. Our facilities have the combined capacity to package and test over 600 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 design for manufacturing, and 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 IATF16949:2016. These Quality Management System certifications represent a recognition of our high quality assurance standards. Both ISO9001 and IATF16949:2016 are sets of criteria and procedures established by the 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 3.0.

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 controls, 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 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 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. In February 2023, the Company entered into a license agreement with a customer, pursuant to which the Company agreed to license its proprietary Silicon Carbide (SiC) technology to the customer and engineering and development services for 24 months for a total fee of $45.0 million, consisting of an upfront fee and various milestone payments over the 24 months. As of June 30, 2025, all revenue has been recognized and all consideration has been received associated with the license agreement and we have no further obligations under this 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, 2025, we had 949 patents issued in the United States, which were based on our research and development efforts, of the 949 issued patents, 855 are active and these patents are set to expire between 2025 and 2043. We also had a total of 961 foreign patents, including 392 Chinese patents, 520 Taiwanese patents, 29 Korean patents, 5 Philippine patents, 8 Japanese patents, 3 Europe patents and 4 India patents as of June 30, 2025. Substantially all of our foreign patents were based on our research and development efforts. These foreign patents will expire in the years between 2025 and 2043. In addition, as of June 30, 2025, we had a total of 165 patent applications, of which 64 patents were pending in the United States, 68 patents were pending in China, 31 patents were pending in Taiwan and 2 patents were pending in India.

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 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

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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.

Human Capital Resources

As of June 30, 2025, we had 2,428 employees, of whom 770 were located in the United States, 1,475 were located in China, and 183 were located in other parts of the world. None of our employees is represented by a collective bargaining agreement. Notwithstanding our global footprint and various geographical locations, we have created an integrated workforce where employees worldwide work and collaborate as a team to advance our common business objectives, while retaining local and regional practices and cultures.

We are committed to providing a work environment in which our employees can realize fully their talents and develop successful careers. As our strength is in our people, we invest significantly in our employees by providing a wide range of training and development opportunities, including mentoring, coaching, tuition reimbursement, attendance at external seminars and professional conferences, and regular in-house training sessions on specific topics. We train our managers to become good stewards for our employees, balancing the need for quality of life with performance results. We believe that these efforts contribute to the growth, well-being and loyalty of our employees, as more than 50% of our managerial positions are filled through promotions of existing employees.

We also keep our employees engaged and informed by providing periodic all-staff communications, and semi-annual performance reviews to ensure that efforts and results are aligned with our business and strategic corporate objectives. We value feedback from our employees and promote an open-door policy which encourages employees to have regular conversations with their managers to share feedback and express concerns. We also solicit employee feedback informally through regular employee interactions such as one on one or functional team staff meetings. In addition, we conduct employee satisfaction surveys at certain locations to help management identify areas that may require improvement. As part of the AOS tradition, we organize regular and seasonal social events, such as team building activities, annual appreciation picnics, and holiday parties, inviting both employees and their families to join. We believe these efforts enable us to build a strong and solid group of dedicated and happy employees who form the core of our human capital resource.

We are committed to providing an environment where employees from all walks of life are treated with respect, care and dignity. We adhere strictly to the Company’s Code of Business Conduct and Ethics and other policies, and ensure that our employment practices respect human rights and comply with national, state and local regulatory requirements at all locations where we conduct business. To recruit new talent, we reach out to a broad range of sources, including employee referrals, on-line advertising, recruitment agencies, and other social media platforms to seek out the best qualified candidates regardless of their backgrounds. We are also focused on ensuring a diverse workforce, including our management team. Our Nominating and Corporate Governance Committee leads the effort in recruiting qualified directors to serve on our Board. Our employees appreciate and value the strength of our people-oriented culture and the benefits our workplace diversity brings.

We commit to a fair and living wage for all employees. We offer competitive compensation and benefits packages for our employees that include a combination of base salary, annual bonus, discretionary bonus for outstanding achievements, an employee stock purchase plan, time-based and performance-based long-term equity compensation. Our equity related compensation programs are designed to motivate and incentivize our employees and align their rewards to financial and other business performance goals, while increasing our shareholder value. We have an established Employee Recognition Award program which is regularly utilized to recognize the outstanding achievements of employees and teams that go above and beyond to achieve AOS business goals. In addition, we have engaged nationally-recognized outside independent compensation consulting firms to independently evaluate the appropriateness and effectiveness of compensation for our executives and other officers and to provide benchmarks for executive compensation as compared to peer companies.

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

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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 ISO 14001 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 worldwide 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, 2025, 2024 and 2023, we were in compliance with the related conflict minerals rule.

Export Control

We are subject to export and import control laws, trade regulations and other trade requirements that limit which products we sell and where and to whom we sell our products. Because we are committed to complying with all applicable export control laws, regulations, and requirements, we have reviewed and revised our processes and procedures to ensure that our shipments to our customers remain compliant with applicable export laws. As part of the enhanced process, we have also conducted extensive risk assessment on export control compliance and implemented training programs for our employees.

Executive Officers

The following table lists the names, ages and positions of our executive officers as of August 15, 2025. There are no family relationships between any executive officers, except that Mr. Stephen C. Chang is a son of Dr. Mike F. Chang.

Stephen C. Chang has served as our Chief Executive Officer since March 2023 and as a director since November 2022. Mr. Chang previously served as the Company’s President from January 2021 to February 2023. Prior to that, Mr. Chang served in various management positions, including Executive Vice President of Product Line Management, Senior VP of Marketing, VP of the MOSFET Product Line, and Senior Director of Product Marketing. Mr. Chang has over 20 years of industry experience and leads the Company’s business strategies, product and technology development, sales and marketing functions, manufacturing operation and supply chain management, and other managerial responsibilities. Mr. Chang received his B.A. in Electrical Engineering from University of California, Berkeley, and M.B.A. from Santa Clara University.

Mike F. Chang, Ph.D., is the founder of our company and serves as our Chairman of the Board and Executive Vice President of Strategic Initiatives. Dr. Chang previously served as Executive Chairman from March 2023 to March 2025. He served as Chief Executive Officer since the founding of our company until March 2023. 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.

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Yifan Liang has been serving as our Chief Financial Officer since August 2014 and Corporate Secretary since November 2013. Mr. Liang served as our Interim Chief Financial Officer from November 2013 to August 2014, our Chief Accounting Officer from October 2006 to November 2013, and our Assistant Corporate Secretary from November 2009 to November 2013. Mr. Liang became our company's corporate controller in August 2004. 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.

Wenjun. Li, Ph.D., has been serving as our Chief Operating Officer since August 2021. Prior to that, Dr. Li served in various management positions in our Company since 2012, including Executive Vice President of World-Wide Manufacturing, Senior Vice President of World-Wide Manufacturing, Vice President of Front-End Operation, the director of Process Integration and Senior Manager of Process Integration. Dr. Li holds a B.S. in Chemistry and a M.S. in Chemical Engineering from Taiyuan University of Technology, and a Ph.D. in Microelectronics & Solid-State Electronics from the Research Institute of Micro-Nanometer Technology at Shanghai Jiao Tong University.

Bing Xue, Ph.D., has been serving as our Executive Vice President of Worldwide Sales and Business Development since January 2021. Prior to that, Dr. Xue held various managerial positions in our company since 2003, including Senior Vice President of Global Sales, Vice President of Global Sales, Vice President of Worldwide Manufacturing, and General Manager of China Operation. Prior to joining us, Dr. Xue served as the Director of Engineering in Dowslake Microsystem from 2001 to 2003. Dr. Xue received his B.S. in Physics from Xiamen University, and Ph.D. in Physical Chemistry from University of Pennsylvania.

Corporate Information

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. The address of our U.S. office is Alpha and Omega Semiconductor Incorporated, 475 Oakmead Parkway, Sunnyvale, CA 94085. The telephone number of our U.S. office is (408) 830-9742. We have incorporated various wholly-owned subsidiaries in different jurisdictions. Please refer to Exhibit 21.1 to this Form 10-K for a complete list of our subsidiaries.

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. In addition, the SEC maintains a website (www.sec.gov) that contains reports, proxy statements, and other information that we file electronically.