AMKOR TECHNOLOGY, INC. (AMKR) Business

Item 1.Business

OVERVIEW

Amkor is the world’s largest U.S. headquartered outsourced semiconductor assembly and test service provider (“OSAT”) and is a global leader in outsourced semiconductor packaging and test services. With a strong track record of innovation, a broad and diverse geographic footprint and solid partnerships with lead customers, Amkor delivers high-quality solutions that enable the world’s leading semiconductor and electronics companies to bring advanced technologies to market. The company’s comprehensive portfolio includes advanced packaging, wafer-level processing and system-in-package solutions targeting applications for smartphones, data centers, artificial intelligence, automobiles and wearables. Amkor has built a leading position by:

•Designing and developing innovative packaging and test technologies focused on advanced packaging solutions in key markets, including artificial intelligence;

•Building expertise in high-volume manufacturing processes and developing a reputation for high quality and solid execution;

•Providing a geographically diverse operating base with manufacturing facilities in multiple countries, including in the United States, where the Arizona Facility is under construction;

•Cultivating long-standing relationships with our customers and industry partners;

•Focusing on strategic end markets that offer solid growth potential; and

•Developing a competitive cost structure through disciplined capital investment.

Our packaging and test services are designed to meet application and chip-specific requirements, including: the required type of interconnect technology; size; thickness; and electrical, mechanical and thermal performance. We provide turnkey packaging and test services including wafer bump, wafer probe, wafer back-grind, package design, packaging, burn-in, system level and final test and drop shipment services. Our customers use us for one or more of these services.

We provide our services to integrated device manufacturers (“IDMs”), “fabless” semiconductor companies, original equipment manufacturers (“OEMs”) and contract foundries. IDMs generally design, manufacture, package and test semiconductors in their own facilities. However, the availability of technologically advanced outsourced manufacturing services has encouraged IDMs to outsource a portion of their manufacturing. By offering a broad package portfolio, Amkor allows IDMs to outsource packaging and test services and focus their investments on core competencies such as silicon fabrication. Fabless semiconductor companies do not have factories. They focus exclusively on semiconductor design and outsource virtually every step of the manufacturing process, utilizing contract foundries to manufacture their semiconductors in wafer form and companies such as Amkor for their packaging and test needs. Some companies will engage a contract foundry to manage the complete semiconductor manufacturing process, and, in turn, the contract foundry will outsource some of its packaging and test needs.

INDUSTRY BACKGROUND

Semiconductor devices are essential building blocks in most electronic products. As electronic and semiconductor devices have evolved, several important trends have emerged that have fueled the growth of the overall semiconductor industry, as well as the market for outsourced semiconductor packaging and test services. These trends include:

•Accelerating adoption of artificial intelligence applications by both enterprises and consumers, which has increased demand for computing power at data centers and in edge computing devices such as smartphones, autonomous vehicles and consumer and industrial devices.

•Growing demand for smart mobile and connected devices, including the worldwide adoption of smartphones, tablets and other Internet-of-Things (“IoT”) devices that can access the internet and provide multimedia capabilities.

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•The proliferation of semiconductor devices into well-established end products such as automotive systems for advanced driver assistance systems (“ADAS”), electrification and infotainment.

•The increased demand for new broadband wired and wireless networking equipment.

•The adoption of heterogeneous integration (diverse dies positioned close to each other within the same package) for scaling performance beyond Moore’s Law to achieve improved power efficiency, design flexibility and scalability in data center computing, artificial intelligence and similar end uses.

•The growth of advanced system-in-package (“SiP”) modules (combining multiple semiconductor and other electronic components in a single package) to meet the demand for miniaturization and higher functionality at competitive cost.

•An increase in the semiconductor content within electronic products to provide greater functionality and higher levels of performance.

•The continued build out of 5G infrastructure and 5G enabled devices.

•Digitalization, driving expansion of data generation and storage.

As a supplier in the semiconductor industry, our business is cyclical and impacted by broad economic factors, such as worldwide gross domestic product and consumer spending. With the exception of 2020, when the Covid-19 pandemic caused worldwide gross domestic product levels to decline during a period of strong growth in the semiconductor industry, there has generally been a strong correlation between worldwide gross domestic product levels, consumer spending and semiconductor industry cycles. The semiconductor industry has experienced significant and sometimes prolonged cyclical upturns and downturns in the past. We cannot predict the timing, strength or duration of any correction, economic slowdown, recession or subsequent economic recovery.

Outsourcing Trends in Semiconductor Manufacturing

Semiconductor companies outsource their packaging and test needs to service providers such as Amkor for the following reasons:

Packaging and test service providers have developed expertise in advanced technologies.

The increasing demands for miniaturization, greater functionality, lower power consumption and improved thermal and electrical performance are driving the continuous development of semiconductor packaging and test technologies that are increasingly complex, capital intensive and customized. This trend has led many semiconductor companies and OEMs to view packaging and test as enabling technologies that can benefit from the technological innovation expertise found in the leading outsourced assembly and test companies. At the same time, these companies are often looking to reduce their internal manufacturing and research and development costs for packaging and test solutions. As a result, many of these companies are increasingly relying on packaging and test service providers as key sources for new package designs and advanced interconnect technologies.

Packaging and test service providers can facilitate a more efficient supply chain and help shorten time-to-market for new products.

We believe that semiconductor companies, together with their customers, are seeking to shorten the time-to-market for new products and that an efficient supply chain is a critical factor in facilitating timely and successful product introductions. Packaging and test service providers have the resources and expertise to timely develop and implement new packaging technology in high volume. For this reason, semiconductor companies and OEMs are leveraging the capabilities of outsourced packaging and test service providers to bring new high quality products to market more quickly.

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High quality packaging and test service providers enable semiconductor manufacturers to focus their resources on semiconductor design and wafer fabrication.

As semiconductor process technology migrates to larger wafers and smaller feature sizes, the cost of building a state-of-the-art wafer fabrication factory has risen significantly. The high cost of investing in next generation silicon technology and equipment is causing many semiconductor companies to adopt or maintain a “fabless” or “fab-lite” strategy to reduce or eliminate their investment in wafer fabrication and associated packaging and test operations. As a result, these companies are increasing their reliance on outsourced providers of semiconductor manufacturing services, including high quality packaging and test solutions.

Packaging and test service providers offer a cost-effective solution in a cyclical, capital intensive industry.

The semiconductor industry is cyclical by nature and impacted by broad economic factors, such as changes in worldwide gross domestic product and consumer spending. Semiconductor packaging and test are complex processes requiring substantial investment in specialized equipment, factories and human capital. As a result of this cyclicality and the large investments required, manufacturing facilities must operate at consistently high levels of utilization to be cost-effective. Shorter product life cycles, coupled with the need to update or replace packaging and test equipment to accommodate new package types, make it more difficult for IDMs to maintain cost-effective utilization of their packaging and test assets throughout semiconductor industry cycles. Packaging and test service providers, on the other hand, can typically use their assets to support a broad range of customers and multiple end markets, potentially generating more efficient use of their production assets and a more cost-effective solution.

STRATEGY AND COMPETITIVE STRENGTHS

Amkor’s primary financial objective is profitable sales growth. Our strategy is built on providing industry-leading packaging and test technologies, expanding our global manufacturing footprint, including new investments in the U.S, and deepening strategic partnerships with leading semiconductor companies. These strategic pillars enable us to deliver innovative, reliable and cost-effective solutions, strengthen customer relationships and diversify our revenue streams, which position Amkor for sustainable, profitable growth and create long-term value for our shareholders.

We believe that the following three pillars position us well to capture growth across high-value markets:

Elevate Technology Leadership

Amkor is a global leader in advanced semiconductor packaging and test technologies, enabling next-generation devices across key markets such as high-performance computing (“HPC”) and artificial intelligence (“AI”), automotive, IoT and mobile communications. Our technology leadership encompasses areas such as high density fan-out (“HDFO”), including SWIFT and S-Connect packaging technologies, 2.5D integration, advanced flip chip, fine pitch bumping, wafer-level processing and advanced system-in-package (“SiP”) solutions, which support the industry’s drive toward smaller form factors, higher integration, improved performance and lower power consumption.

We collaborate closely with leading semiconductor companies and OEMs to co-develop innovative solutions, including wafer-level fan-out (“WLFO”), Silicon Photonics (“SiPh”), Co-Packaged Optics (“CPO”) and high-power modules incorporating gallium nitride (“GaN”) and silicon carbide (“SiC”) devices. Our advanced packages may incorporate Through Silicon Via (TSV) interconnects and silicon interposers, enabling the integration of high-bandwidth memory and graphics processors into a single package.

Amkor’s broad offering of semiconductor package design, packaging and test services addresses the diverse needs of our customers. We provide turnkey solutions that include package design, wafer bump, wafer probe, wafer back-grind, packaging, burn-in, system level and final test and drop shipment services. Our extensive line of packaging and test services covers analog, digital, logic, mixed signal, memory, sensors and radio frequency devices. This breadth of services allows customers to streamline their supply chains, limit the number of suppliers and focus their resources on semiconductor design and wafer fabrication.

Our commitment to technology leadership is reinforced by ongoing investment in research and development, environmental responsibility and sustainable manufacturing practices. We continually advance our processes and package designs to meet evolving customer needs, minimize the use of harmful materials and optimize energy and water usage.

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Expand our Geographic Footprint

Amkor’s broad and strategically located manufacturing footprint is a key differentiator, enabling us to deliver flexible, resilient and cost-effective solutions to customers worldwide. With facilities located in key manufacturing regions in Asia and Europe, we provide customers with multiple options to mitigate risk, diversify supply chains and support regionalization initiatives.

As a U.S. headquartered OSAT, we are expanding our manufacturing footprint with the construction of a new facility in Arizona. Construction began in the second half of 2025, and we believe that this investment will strengthen our ability to serve customers seeking to regionalize their supply chains and will enhance our participation in U.S. semiconductor initiatives. In addition, we continue to scale production in our Vietnam facility, which opened in 2024, further increasing our capacity and operational flexibility in Asia. Our scale and geographic diversity allow us to qualify production at multiple sites, optimize asset utilization and absorb large orders that require quick turnaround. By leveraging our purchasing power and operational expertise, we look to secure favorable pricing and supply agreements for materials and equipment, further enhancing our competitive position.

Our global presence not only strengthens customer relationships and diversifies our revenue streams but also enables us to meet customer-specific requirements and support localized supply chains.

Enhance Strategic Partnerships in Key Markets

Amkor has built long-standing relationships with most of the world’s leading semiconductor companies over the last five decades. Our operational excellence, high quality, reliability and predictability have been key to attracting and retaining customers. Our collaborative approach enables us to work closely with customers and suppliers to co-develop proprietary process technologies, accelerate time-to-market, improve quality and lower costs. We work closely with lead customers in the following key markets to deliver advanced packaging solutions tailored to evolving industry needs.

•HPC and AI: Artificial intelligence and increasing demand for improved networking speed and storage within data centers, cloud computing, PCs and laptops are driving demand for more semiconductors and advanced packaging in the computing end market.

•Automotive: Increasing semiconductor content in automobiles is driving demand for advanced packaging to enable safety features such as ADAS, in-car computing, radar and digital cockpit features such as infotainment displays and telematics. Increasing battery voltage, higher voltage power converters, onboard chargers, automotive inverter components and microcontrollers also require innovative power packaging solutions.

•IoT: Hearables, watches and augmented and virtual reality devices integrate multiple functions, such as processors, sensors and connectivity devices, into small form factors, which requires innovation in advanced packaging.

•Mobile communications: We have a strong position across multiple device functionalities within premium and high-tier smartphones. We are collaborating with industry leaders as smartphones transition to include artificial intelligence and drive semiconductor growth through the adoption of new wireless standards, the integration of a broadening range of applications, enhanced features and higher performance requirements to support increased data processing. The trend to greater functionality drives miniaturization and innovation enabled by advanced packaging.

PACKAGING AND TEST SERVICES

In general, the semiconductor manufacturing process consists of IC design, wafer fabrication, wafer probe, packaging and final test. The packaging and test services we provide occur subsequent to wafer fabrication, and the wafers that we receive from our customers are generally consigned to us.

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Advanced Products and Mainstream Products

We offer a broad range of advanced and mainstream packaging and test services to our customers. We refer to our flip chip, memory, wafer-level processing and related test services as “Advanced Products” and to our wirebond packaging, power device packaging and related test services as “Mainstream Products.” The following table sets forth, for the periods indicated, net sales for Advanced Products and Mainstream Products and the percentage of total net sales for each service offering.

Advanced Products

Our Advanced Products include the following packaging types: flip-chip chip-scale packages (“FC CSP”), flip chip ball grid array (“FCBGA”), memory and wafer-level packages. These package families use flip chip interconnect technology so that the die can be connected to a substrate package carrier or, in the case of wafer-level chip scale packages, directly to a printed circuit board.

FC CSP Package Products: FC CSP packages are small form factor packages where the substrate size is not much larger than the die itself.

•FC CSP can be a single die or multi die format. The size advantage provided by CSP technologies has made FC CSP an attractive choice for a wide variety of applications that require very small form factors, such as smartphones, tablets and other mobile consumer electronic devices.

•Flip chip stacked chip scale packages (“FC SCSP”) stack a second die on top of the original flip-chip die. The top die is typically a memory device, and wirebond interconnects are used to attach the top die to the substrate. FC SCSP is frequently used to stack memory on top of digital baseband and applications processors for use in mobile devices.

•Package on Package (“PoP”) technology innovations drive thinner package solutions through the development of ultra-thin substrates and enhanced pre-stacking and thin die handling capabilities.

•Fine pitch copper pillar flip chip interconnect technology creates interconnects at finer pitches using a plating process to reduce the number of substrate layers to facilitate very thin packages. This innovative technology also enables package stacking with TSVs.

FCBGA Products: FCBGA packages are large form factor substrate-based packages which are used where processing power and speed are a higher priority than a small form factor. Our FCBGA packages are assembled using state-of-the-art substrates. Utilizing multiple high density routing layers, laser drilled vias and ultra-fine line and space metallization, FCBGA substrates have the highest routing density available. The variety of FCBGA package options, from large single die to multi-chip packages with memory, allows package selection to be tailored to the specific thermal requirements of the end product. We offer FCBGA packaging in a variety of product formats to fit a wide range of applications, including networking, storage, computing, automotive and consumer. Some FCBGA products incorporate 2.5D technology, which utilizes high density silicon interposers to enable the integration of high-performance chips, such as high bandwidth memory and graphics processors, into a single package.

Memory Products: Memory packages consist of either standalone packaging and testing or a combination of NAND Flash, DRAM or a memory controller IC using a variety of packaging technologies, including FC, SCSP, SiP and other advanced packaging technologies. These products are used as system memory or platform data storage in all of our end markets.

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Wafer-level Package Products: We offer various types of wafer-level packages: wafer-level CSP; WLFO; SiPh and CPO; and HDFO. Wafer-level CSP and WLFO are complementary technologies and customers can choose between these package types as their die sizes shrink or grow.

•Wafer-level CSP packages (also known as fan-in wafer-level packages) do not utilize a package carrier. The bumped wafer is singulated into individual die, and the wafer-level package is then attached directly to the system board. Wafer-level CSP offers one of the lowest total system costs, enabling higher semiconductor content while leveraging the smallest form factor and one of the highest performing, most reliable semiconductor package platforms on the market today. Applications for wafer-level CSP include power management, transceivers, sensors, wireless charging, codecs and specialty silicon for new or unique functionality.

•WLFO packages (also known as low-density fan-out packages) are utilized for ICs where the die surface area is too small to accommodate all of the required bond pads. The fan-out package enlarges the bondable surface area by building a border around the die using low-cost molding compound. These packages can include multiple die. Applications for WLFO packages include power management, transceivers, radar and specialty silicon.

•SiPh and CPO allow for the integration of fiberoptic interconnects both within a package and within the server architecture to reduce power consumption, heat generation and improve performance. Amkor has supported previous generations of SiPh packaging needs and is aligned with the market to support its future needs, through chip on wafer, chip on chip and other advanced packaging solutions.

•HDFO can either replace the laminate substrate with a thinner structure or reduce the complexity of the substrate by housing the dense interconnects and bridges in the redistribution layer structure, allowing for a less expensive substrate that provides a high level of performance with a balanced cost structure. HDFO solutions enable high performance in a compact form factor that combines tiled processors, memory, I/O (input/output) die and other peripheral ICs.

Mainstream Products

Our Mainstream Products use wirebond interconnect technology to connect a die to a leadframe or substrate package carrier and include leadframe packages, substrate-based wirebond packages and micro-electro-mechanical systems (“MEMS”) packages.

Leadframe Packages: Leadframe packages use wirebond or flip chip technology to connect a die to a leadframe package carrier. Leadframe packages are used in many electronic devices and remain the most practical and cost-effective solution for many low to medium pin count analog and mixed signal applications.

•Traditional leadframe packages support a wide variety of device types and applications. Two of our most popular traditional leadframe package types are small outline IC and quad flat package, commonly known as “dual” and “quad” products, respectively, based upon the number of sides from which the leads extend. The traditional leadframe package family has evolved from “through hole design,” where the leads are plugged into holes on the circuit board to “surface mount design,” where the leads are soldered to the surface of the circuit board. We offer a wide range of lead counts and body sizes to satisfy variations in the size of customers’ semiconductor devices.

•Through a process of continuous engineering and customization, we have designed several leadframe package types that are thinner and smaller than traditional leadframe packages and can accommodate more leads on the perimeter of the package. These leadframe packages typically have superior thermal and electrical characteristics, which allow them to dissipate heat generated by high-powered semiconductor devices while providing enhanced electrical connectivity. We are developing increasingly smaller versions of these packages to keep pace with continually shrinking semiconductor device sizes and demand for miniaturization of portable electronic products. One of our more successful leadframe package offerings is the MicroLeadFrame family of quad flat no lead packages. These packages offer cost effective, miniaturized solutions for multiple analog power and signal chain applications.

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•Power discrete devices use a leadframe as the package carrier and primarily use wirebond interconnect technology. However, power applications that require improved thermal and electrical performance will use packaging with copper clip interconnect technology that creates multi die power modules with wafers from silicon carbide and other wide band gap materials.

Substrate-based Wirebond Packages: Substrate-based wirebond packages use wirebond technology to connect a die to a substrate. Some of our packages in this category include stacked CSP, wirebond ball grid array packages and plastic ball grid array (“PBGA”) packages.

•Stacked CSP technology enables the stacking of a wide range of different semiconductor devices to deliver high levels of silicon integration and area efficiency. Stacked CSP utilizes high density thin core substrates and advanced materials, along with leading-edge wafer thinning, die attach and molding capabilities, to stack multiple die on a substrate. Stacked CSP is ideal for memory and mixed signal applications.

•Wirebond ball grid array packages offer a broad selection of ball array pitches, ball counts and body sizes, single and multi-die layouts, stacked die and passive component integration together with thermal management solutions. They are applicable for a wide range of semiconductors requiring a smaller package size than conventional PBGAs or leadframe packages.

•PBGA packages are used in applications requiring higher pin count than leadframe packages but typically have lower pin counts than flip chip. PBGA packages are designed for low inductance, improved thermal operation and enhanced surface-mount technology ability. Custom performance enhancements, like ground and power planes, are also available.

Micro-Electro-Mechanical Systems Packages: MEMS are miniaturized mechanical and electro-mechanical devices that can sense and provide information about the physical world and sometimes trigger a response. Examples of MEMS devices include microphones, accelerometers, airbag deployment sensors, gyrometers, magnetometers and humidity, temperature and pressure sensors. We also specialize in sensor fusion products which utilize our cavity MEMS platform and combine multiple sensors into a single package. MEMS packages leverage our expertise in wafer thinning, die stacking, wirebonding and flip chip interconnect to deliver sophisticated products with a very small form factor.

Advanced System-in-Package Modules

Advanced SiP modules combine multiple semiconductor and other electronic components with different functionalities into a single package. These modules use wirebond, flip chip or wafer-level interconnect technologies. Components can include ICs, passive devices (inductors, capacitors, resistors, filters and diplexers), antennas and mechanical parts.

The increasing demand for miniaturization and higher functionality at competitive cost is driving the adoption of advanced SiP in new products. Advanced SiP modules are used for many applications such as radio frequency (“RF”) and front-end modules, basebands, connectivity, fingerprint sensors, display and touch screen drivers, sensors and MEMS, NAND memory and solid state drives. Advanced SiP modules are found in many products including smartphones and tablets, automobiles, IoT wearables, high-performance gaming systems, computers and network systems.

In 2025, 2024 and 2023, we had net sales of approximately $3,080 million, $3,085 million and $2,955 million, respectively, from our advanced SiP modules, which are mostly included in Advanced Products, depending upon the interconnect technology used in the module.

Test Services

Our Test Services complement our wafer and packaging services across our Advanced and Mainstream Products. Our test services offer customers the cycle time and cost advantages of co-located turn-key services and are differentiated by our geographically diverse locations, high quality execution and delivery and our expertise, particularly for wafer level test. Our test services are used as both an interim step or as the final testing step to ensure screening and rejection of defects, performance grading and overall outgoing quality and reliability. Interim testing eliminates the manufacturing costs of assembling the defective chips. Below is a description of our test services:

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•Wafer Level Test: Wafer level test is a manufacturing step performed while a wafer is still in its full form and before being singulated for further package processing.

•Package Level Test: Package level test is performed on a product or products that have been assembled in a package.

•Burn-In Test: Burn-in test is a process in which components of a system are exercised, monitored and measured in extreme operational conditions such as high temperature, voltage and frequency over time. The purpose of the environmental and operational stress conditions of burn-in testing is to accelerate and screen early life failures and estimate and monitor long-term degradation and ultimate lifetime.

•System Level Test: System level test identifies defective products that may not otherwise be screened by traditional wafer level, package level or burn-in testing. As advanced packaging proliferates and the integration of more individual components into a package grows, system level testing becomes more important.

•Test Development Services: Prior to mass production, an integrated manufacturing ready test solution must be developed and deployed. Amkor’s test development services offer both co-development and full development of complete test software and hardware solutions to our customers. These services also enable early engagement with our customers in the product design phases for maximum compatibility with manufacturing. Our test development teams are experienced in a full suite of test engineering disciplines for Memory, Power, RF, Mixed Signal, Analog and digital test solution development.

End Markets

The following table lists the end markets that use our products and sets forth, for the periods indicated, the percentage of net sales in each end market:

RESEARCH AND DEVELOPMENT

We believe that technology development is one of the keys to success in the semiconductor packaging and test industry. Our research and development efforts focus on developing new packaging technologies and test solutions to meet evolving customer needs for higher performance, greater integration, smaller form factors and lower costs. Key areas of focus include:

•Heterogeneous integration: Developing multi-chip module solutions, including 2.5D and HDFO with and without bridges to provide high-bandwidth die-to-die interconnects, that enable package level integration of different types and levels of silicon technologies for high performance computing, networking and data center applications. This is accomplished by combining processors, chiplets or integrated passive devices into one packaged module. Through die partitioning and heterogeneous integration, these modules provide higher functionality at lower total product cost.

•Wafer-level and panel-level packaging: Innovating 2D and 3D wafer-level chip-scale packages and WLFO packages are increasingly the preferred package type for many applications in IoT and mobile devices, including processors, power management integrated circuits (“PMICs”), display drivers and antenna package products. We believe that our development of Panel Level Fan Out (“PLFO”) technology will permit greater economies of scale for fan-out package devices manufactured on a panel versus wafer basis.

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•Copper hybrid bonding: Developing an emerging 3D integration technique that directly joins copper interconnects between stacked chips or wafers, enabling extremely dense, ultra fine pitch interconnects to provide performance and power advantages over traditional microbump interconnects.

•Highly integrated SiP modules: Creating compact, cost efficient modules such as DSMBGA and DSMLGA packages to minimize form factor and reduce material and processing costs for wearables and mobile devices.

•Advanced automotive packaging: Developing new package technologies as higher performance computing, energy efficiency, power distribution and sensor content are used to support new automotive features including ADAS, infotainment, optical sensors and electric vehicles. In addition, we are developing high power modules involving SiC-based devices.

•Co-Packaged Optics: Advancing CPO technologies to participate in the scaling of the datacenter and artificial intelligence industries. We believe that our CPO packaging technology developments will permit ever increasing interface bandwidth improvements between processors, artificial intelligence accelerators, memory and other support components, all coupled together through our CPO solutions.

Our research and development teams are located across our facilities with the primary Center of Excellence based in Korea. In 2025, 2024 and 2023, we incurred $166.7 million, $163.0 million and $177.5 million, respectively, of research and development expense.

SALES AND MARKETING

Our sales offices are located throughout Asia, Europe and the United States. Our support personnel manage and promote our packaging and test services and provide key customer and technical support. To provide comprehensive sales and customer service, we typically assign our customers a direct support team consisting of a sales manager, assembly and test technical program managers and both field and factory customer support representatives. We also support our largest multinational customers from multiple geographic office locations to ensure that we are aligned with their global operational and business requirements.

Our direct support teams are further supported by an extended staff of product, process, quality and reliability engineers, as well as marketing and advertising specialists, information systems technicians and factory personnel. Together, these direct and extended support teams deliver an array of services to our customers.

SEASONALITY

Our sales have generally been higher in the second half of the year than in the first half due to consumer buying patterns in the United States, Europe and Asia and the timing of flagship mobile device launches. In addition, semiconductor companies generally reduce their production during the holidays at the end of December, which generally results in a decrease in packaging and test services during the first quarter. General economic conditions, changes in our product mix or overall demand in any of our end markets can impact our seasonality.

CUSTOMERS

Our customers include most of the world’s largest semiconductor companies. Our ten largest customers accounted for 72% of our net sales in 2025. Direct sales to Apple and Qualcomm accounted for 29.8% and 11.1% of our net sales, respectively, for the year ended December 31, 2025.

MATERIALS AND EQUIPMENT

Materials

Our materials are used primarily for packaging activities. Our packaging operations depend upon obtaining adequate supplies of materials on a timely basis. The principal materials used in our packaging process are laminate substrates, ICs, capacitors, leadframes and bonding wires. The silicon wafer is generally consigned from our customer. We generally do not take ownership of the customer consigned wafer, and title and risk of loss remains with the customer for these materials. Test materials constitute a very small portion of our total test cost. Generally, we purchase materials based on Amkor’s commitments to customer forecasts, and our customers are generally responsible for any unused materials we purchase based on such commitments.

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We obtain the materials required for packaging services from various suppliers and source most of our materials, including critical materials such as leadframes, laminate substrates and bonding wires, from a limited group of suppliers. We work closely with our primary material suppliers to ensure consistent quality, availability and timely delivery. We also negotiate worldwide pricing agreements with our major suppliers to take advantage of the scale of our operations.

Equipment

Our ability to meet the changing demand from our customers for manufacturing capacity depends upon obtaining packaging and test equipment in a timely manner. We work closely with our main equipment suppliers to coordinate the ordering and delivery of equipment to meet our expected capacity needs.

The primary types of equipment used in providing our packaging services are wire bonders, die bonders, chip shooters and die attach. In addition, we maintain a variety of other packaging equipment, including mold, singulation, ball attach and wafer backgrind, along with numerous other types of manufacturing equipment. A substantial portion of our packaging equipment base can generally be used and adapted to support the manufacture of many of our packages.

We also purchase wafer bumping equipment to facilitate our flip chip and wafer level packaging services such as 2.5D and HDFO, which is used for HPC and artificial intelligence systems. Wafer bumping equipment includes sputter and spin coaters, electroplating equipment, reflow ovens and other types of equipment. This equipment tends to have longer lead times for delivery and installation than other packaging equipment and is sold in relatively larger increments of capacity.

The primary equipment used in the testing process includes testers, handlers and probers. Handlers are used to transfer individual or small groups of packaged ICs to a tester. Test equipment is generally a more capital-intensive activity than packaging, and test equipment tends to have longer delivery lead times than most types of packaging equipment. We focus our capital expenditures on standardized tester platforms to maximize test equipment utilization where possible. In some cases, our customers will consign test equipment to us.

GOVERNMENTAL REGULATIONS

As a public company with global operations, we are subject to various federal, state, local and foreign laws, and our products and services are governed by a number of rules and regulations. These regulations, which differ among jurisdictions, include financial and other external reporting disclosure rules, accounting standards and environmental, corporate governance, intellectual property, tax, trade, antitrust, employment, immigration and travel, privacy and anti-corruption laws. Costs and accruals incurred to comply with these governmental regulations are presently not material to our capital expenditures, results of operations and competitive position. Although there is no assurance that existing or future government laws applicable to our operations, services or products will not have a material adverse effect on our capital expenditures, results of operations and competitive position, we do not currently anticipate material expenditures for compliance with government regulations.

Environmental Matters

We use chemicals and materials in the semiconductor packaging process that generate byproducts such as wastewater, solid waste and flue gas. For example, water used for rinsing or cooling wafers being sawed or used in the etching or solder deposition process produces wastewater. Scrap from metal lead-frame or substrate processing or excessive molding resin produces solid waste. Emissions from solvents used for coating produce flue gases. In addition to byproducts, semiconductor packages have historically contained lead, a naturally occurring element that can be toxic. The use of lead in our packages has decreased over time due to the use of lead-free alternatives. The use and storage of chemicals and materials are subject to various laws and regulations governing waste disposal, water discharge, emissions into the atmosphere and employee health and safety. We make continuous efforts to comply with these environmental laws and regulations, including environmental management systems, safety training for employees and pollution control at our factories.

In the future, we may be subject to changes to existing environmental regulations or new green initiatives required by our customers, investors, governments or other stakeholders. We do not believe that capital expenditures or other costs attributable to compliance with environmental laws and regulations or green initiatives will have a material adverse effect on our business, liquidity, results of operations, financial condition or cash flows.

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COMPETITION

The outsourced semiconductor packaging and test market is highly competitive, and geopolitical trade tensions have increased competition from Chinese firms supporting a China-for-China supply chain. We face competition from established packaging and test service providers primarily located in Asia, including ASE Technology, JCET Group and Powertech Technology.

Additionally, we compete with contract foundries and electronic manufacturing service providers or contract electronics manufacturers, which offer certain types of advanced packaging. Our IDM customers also evaluate our services and scale against their own in-house capabilities.

The key competitive factors in the outsourced semiconductor packaging and test services market are:

•Advanced packaging technology

•Geographic location of services

•Manufacturing scale and expertise

•Customer co-development and innovation

•Investment in new technology and capacity

•Quality and reliability

•Price

•Cycle time

We believe we are competitive in these areas.

INTELLECTUAL PROPERTY

We maintain an active program to protect and derive value from our investment in technology and the associated intellectual property rights. Intellectual property rights that apply to our various products and services include patents, copyrights, trade secrets and trademarks. We have filed and obtained a number of patents in the United States and other countries, and their durations vary depending on the jurisdiction in which each patent is filed. Although our patents are an important element of our intellectual property strategy, we are not materially dependent on any one patent or any one technology. We expect to continue to file patent applications when appropriate to protect our proprietary technologies, but we cannot provide assurances that we will receive patents from pending or future applications. In addition, any patents we obtain could be challenged, invalidated or circumvented and may not provide meaningful protection or other commercial advantage to us. Nonetheless, we believe that our patents afford an important means of protection for our technologies. Further, to distinguish our products from our competitors’ products, we have obtained certain trademarks and service marks and may promote our particular brands through advertising and other marketing techniques.

We also protect and maintain the confidentiality of certain information about our processes, products and strategies which we believe provides us with a competitive advantage. We have ongoing programs designed to maintain the confidentiality of such information. As part of these efforts, all employees who have access to Amkor’s information systems are required to participate in cybersecurity training within the first 15 days of employment, after which recurring mandatory training is required on an annual basis.

HUMAN CAPITAL RESOURCES

Amkor believes that its future success is highly dependent upon our continued ability to attract, retain and motivate qualified employees. As part of our effort to attract and motivate employees, Amkor is committed to providing competitive and comprehensive benefits that are designed to enable our employees and their families to live healthier and more secure lives. Additionally, Amkor has implemented various retention programs to incentivize and retain high-performing employees. We regularly evaluate such retention programs and our compensation practices generally to ensure they remain competitive and are aligned with local market practices. We look to promote our management-level employees from within Amkor, and we believe that we have been successful in this effort. Factory locations also maintain training and development programs that enable the continued learning and growth of our employees, and senior management regularly meets to share and implement best practices among our various facilities.

Amkor also uses human capital initiatives to support our broad geographic footprint. For career development and advancement, we may provide employees with the opportunity to move between factories, often in support of new factories or the introduction of new packaging offerings. We believe that these initiatives are efficient for training new local employees and allow existing employees to continue to develop in their careers.

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We believe that our efforts to motivate, retain and support the growth of qualified employees is reflected in the long average tenure of many of our key employees.

As of December 31, 2025, Amkor employed 30,800 employees, of whom approximately 95%, 4% and 1% resided in the Asia-Pacific region, Europe and the United States, respectively. Our global workforce spans 12 countries, reflecting various cultures, backgrounds, ages, genders and ethnicities. Our employees in France, Germany, the Philippines, Singapore and the United States are not represented by any union. Certain employees at our factories in China, Japan, Korea, Malaysia, Portugal, Taiwan and Vietnam are members of a union, and we operate subject to collective bargaining agreements that we have entered into with these unions. We believe that our relations with our employees are good, and we have not experienced a work stoppage in any of our factories.

AVAILABLE INFORMATION

Amkor files annual, quarterly and current reports, proxy statements and other information with the SEC. The SEC maintains a website that contains annual, quarterly and current reports, proxy statements and other information that issuers (including Amkor) file electronically with the SEC. The SEC’s website is www.sec.gov.

Amkor’s website is www.amkor.com. Amkor makes available, free of charge, through its website: our annual reports on Form 10-K; quarterly reports on Form 10-Q; current reports on Form 8-K; Forms 3, 4 and 5 filed on behalf of directors, executive officers and certain stockholders; and any amendments to those reports filed or furnished pursuant to the Securities Exchange Act of 1934, as amended (the “Exchange Act”), as soon as reasonably practicable after such material is electronically filed with, or furnished to, the SEC. We also make available, free of charge, through our website, our Corporate Governance Guidelines, the charters of the Audit Committee, Nominating and Governance Committee, Compensation Committee and Finance Committee of our Board of Directors, our Code of Business Conduct, our Code of Ethics for Directors and other information and materials. The information on Amkor’s website is not incorporated by reference into this Form 10-K.