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Item 1. Business

2026-02-20 compared with 2025-02-21 · 103 added, 132 removed, 250 unchanged (48% of the section changed)

Amkor is the world’s largest U.S.

headquartered OSAT (outsourced semiconductor assembly and test) service provider.

Since its founding in 1968, Amkor has pioneered the outsourcing of integrated circuit (“IC”) packaging and test services and is a strategic manufacturing partner for the world’s leading semiconductor companies, foundries, and electronics original equipment manufacturers (“OEMs”).

Amkor provides turnkey manufacturing services for the communication, computing, automotive and industrial and consumer markets, including smartphones, data centers, artificial intelligence, electric vehicles and wearables.

Amkor’s operational base includes production facilities, research and development centers and sales and support offices located in key electronics manufacturing regions in Asia, Europe and the United States.

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 high growth markets, including artificial intelligence;

• 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;

• Providing a geographically diverse operating base with manufacturing facilities in multiple countries across Asia and in Europe;

• Developing a competitive cost structure through disciplined capital investment.

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and electrical, mechanical and thermal performance.

We provide turnkey packaging and test services including wafer bump, wafer probe, wafer back-grind, package design, packaging, system-level and final test and drop shipment services.

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, OEMs and contract foundries.

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.

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INDUSTRY BACKGROUND

Semiconductor devices are essential building blocks used in most electronic products.

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:

• Adoption of artificial intelligence applications within data centers and edge devices such as smartphones, autonomous vehicles and consumer and industrial devices.

• Growing demand for 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.

• 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.

• 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 expansion of 5G infrastructure and 5G enabled devices.

• The proliferation of semiconductor devices into well-established end products such as automotive systems for automation and driver assist, electrification and infotainment systems.

• An increase in mobility and connectivity capabilities, driving demand for new broadband wired and wireless networking equipment.

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

• Digitalization, driving expansion of data generation and storage.

• The adoption of heterogeneous integration (diverse dies positioned close to each other within the same package) to reduce cost, improve yields and deliver required performance in data center computing, artificial intelligence and similar end uses.

• The increase in digital format in our environment, from sensors for automobiles (e.g., pressure, radar, LiDAR and image recognition), mobile devices (e.g., 3D motion, temperature, acceleration and imaging), and IoT (e.g., in-home sensing from temperature to weather and wearables).

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.

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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 more sophisticated, complex, capital intensive and customized.

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.

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STRATEGY AND COMPETITIVE STRENGTHS

Amkor is a leader in advanced packaging technology in the outsourced semiconductor assembly and test market.

Growth in the semiconductor industry is being driven primarily by advanced packaging within the secular growth markets of high-performance computing (“HPC”), automotive, IoT and mobile communications.

We believe Amkor is well positioned in each of these end markets.

• HPC supporting 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.

• Increasing semiconductor content in automobiles is driving increased demand for advanced packaging to enable the proliferation of safety features such as advanced driver assistance systems (“ADAS”) and radar and digital cockpit features such as infotainment displays and telematics.

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.

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.

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 wearables within the consumer end market are evolving in multiple applications, such as hearables, watches and augmented reality and virtual reality devices.

Integration of multiple functions into small form factors, such as processors, sensors and connectivity devices, relies on innovation in advanced packaging.

• Within the communications end market, 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, integration of a broad range of applications, enhanced features, and higher performance requirements to support increased data processing.

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.

Our primary financial objective is profitable sales growth.

We believe that we will continue to achieve that goal and create long-term shareholder value by building on our strength in advanced packaging and executing on the following strategies.

Leverage Our Leadership in Services for Advanced Technologies

We are an industry leader in developing and commercializing advanced packaging and test technologies, which we believe provide substantial value to our customers.

We have dedicated employees engaged in research and development for new semiconductor packaging and test technologies, making us a technology leader in areas such as 2.5D, advanced flip chip, fine pitch bumping, wafer-level processing, advanced SiPs and power modules.

We work closely with our customers to develop cost-effective leading-edge packages for the next generation of devices.

These include integrated technologies such as advanced SiP, wafer-level fan-out (“WLFO”), Silicon Photonics (“SiPh”) and Co-Package Optics (“CPO”), Silicon Wafer Integrated Fan-out Technology (“SWIFT”), High Density Fan-Out (“HDFO”) and redistribution layer (“RDL”) solutions which enable very thin, very small products that combine application processors, memory, baseband and other peripheral ICs.

Our advanced packages may utilize Through Silicon Via (“TSV”) interconnects and silicon interposers, which enable the integration of high-performance chips such as high bandwidth memory and graphics processors into a single package, such as 2.5D.

In addition, we co-develop with customers high power modules incorporating gallium nitride (“GaN”) and silicon carbide (“SiC”) based devices.

Our approach is to work with lead customers to develop processes that will enable volume manufacturing with high yields and reliability.

We believe that demand for advanced packaging services will continue to grow as our customers and leading electronics OEMs strive for smaller device geometries, higher levels of integration and performance and lower power consumption.

We intend to continue to leverage our investment in advanced technology to meet the demand for these services in high growth markets.

Selectively Grow Our Geographically Diverse Footprint through Strategic Investments

We aim to strengthen our leadership position and market share through strategic investment in our geographically diverse manufacturing footprint.

We believe our broad geographic footprint provides customers with multiple options to mitigate risk and diversify their supply chains.

For example, in 2024, we began delivering advanced SiP and memory packages from the Vietnam Facility and acquired the land for our planned Arizona Facility, where construction is expected to begin in the second half of 2025.

In addition, our manufacturing presence in Portugal and our headquarters in the United States are key differentiators for us and position us to participate in initiatives to regionalize supply chains.

We believe that selective growth through these strategic actions can further strengthen customer relationships, help to maintain and enhance our technological leadership, diversify our revenue streams and improve our profits.

Optimize Utilization of Existing Assets

Another key factor in our success is the optimization of asset utilization.

We build and utilize manufacturing lines which support multiple customers, and we increase factory utilization through sophisticated planning processes and intensive efficiency improvement activities.

Competitive Strengths

The outsourced semiconductor packaging and test market is very competitive.

We also compete with the internal semiconductor packaging and test capabilities of many of our customers, foundries and contract manufacturers.

We believe we are well-positioned in the outsourced packaging and test services market.

The following competitive strengths support our strategy to build upon our industry position and remain a preferred provider of semiconductor packaging and test services.

Advanced Packaging Technology Leadership

We are a leader in developing and deploying advanced semiconductor packaging and test solutions.

We have designed and developed several state-of-the-art package formats and technologies such as Double-Sided, Molded Ball Grid Array (“DSMBGA”) SiP and 2.5D.

2.5D technology 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.

In addition, we believe that as semiconductor technology continues to achieve smaller device geometries with higher levels of integration, speed and performance, packages will increasingly require wafer-level Chip Scale Packaging (“CSP”),

WLFO, SWIFT and flip chip interconnect solutions, advanced SiP products and medium and higher power density packages and modules.

We are committed to advancing our key processes and packages, as well as developing innovative test solutions, required for our customers to deliver advanced integrated and modular solutions to their respective markets.

We are also committed to environmental responsibility by creating more sustainable IC packaging.

This involves minimizing the use of harmful materials like lead and optimizing energy and water usage.

Broad Offering of Semiconductor Package Design, Packaging and Test Services

Creating successful interconnect solutions for advanced semiconductor devices often poses unique thermal, electrical and mechanical design challenges, and we employ a large number of engineers to solve these challenges.

This wide variety of packaging offerings is necessary to meet the diverse needs of our customers for the optimal combination of performance, size and cost.

Utilizing Amkor for its innovative packaging, test and design services enables our customers to focus their resources on semiconductor design and wafer fabrication.

We also offer an extensive line of advanced probe and final test services for analog, digital, logic, mixed signal, memory, sensors and radio frequency-semiconductor devices.

We believe that the breadth of our design, packaging and test services is important to customers who seek to limit the number of their suppliers.

Geographically Diversified Manufacturing Base

We have a broad and geographically diverse manufacturing footprint strategically located in eight of the world’s important electronics manufacturing regions.

We believe that our scale and scope allow us to provide a flexible supply chain and cost-effective solutions to our customers by:

• Being located in key regions where customers are actively seeking to develop localized supply chains;

• Qualifying production of customer devices at multiple manufacturing sites with geographical diversity to mitigate the risks of supply disruptions;

• Providing capabilities and solutions for customer-specific requirements;

• Offering capacity to absorb large orders and accommodate quick turn-around times;

• Obtaining favorable pricing and supply agreements on materials and equipment by using our purchasing power and leading industry position.

Long-Standing Relationships and Collaboration with Prominent Semiconductor Companies

Our customers include most of the world’s largest semiconductor companies, and over the last five decades we have developed long-standing relationships with many of these companies.

We believe that our production excellence, including high quality, reliability and predictability, has been a key factor in our success in attracting and retaining customers.

We work with our customers and our suppliers to develop proprietary process technologies to enhance our existing capabilities, reduce time-to-market, improve quality and lower costs.

We believe that our focus on research and product development will enable us to enter new markets early, capture market share and promote the adoption of new package formats.

We collaborate with customers and leading OEMs to develop comprehensive packaging solutions that make it easier for next-generation semiconductors to be designed into next-generation end products.

By collaborating with leading semiconductor companies, foundries and OEM electronics companies, we are able to focus resources on developing new packages that will meet the requirements of new products.

The traditional delineation between front-end semiconductor manufacturing and packaging is starting to converge.

Foundries, and in some cases IDMs, are integrating some packaging activities closer to front-end wafer processes.

We work closely with foundry partners to complement these offerings by offering similar wafer-based technologies as well as downstream processing.

PACKAGING AND TEST SERVICES

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We offer a broad range of advanced and mainstream packaging and test services to our customers.

We refer to our flip chip, 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.

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.

For the Year Ended December 31,

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Advanced Products

Our Advanced Products include flip chip chip scale packages (“FC CSP”), wafer-level packages and flip chip ball grid array (“FCBGA”) packages.

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 Products :

FC CSP Package Products :

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

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FC SCSP is frequently used to stack memory on top of digital baseband and applications processors for use in mobile devices.

We continue to drive thinner package solutions for our Package on Package (“PoP”) technology through the development of ultra-thin substrates and enhancing our pre-stacking and thin die handling capabilities.

We developed fine pitch copper pillar flip chip interconnect technology, which creates interconnections at finer pitches using a plating process to reduce the number of substrate layers to facilitate very thin packages.

This innovative solution is also an enabling technology for package stacking with TSVs.

• 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:

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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 needs of the end product.

We offer FCBGA packaging in a variety of product formats to fit a wide range of end application requirements, including networking, storage, computing, automotive and consumer applications.

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, PoP and

other state-of-the-art packaging technologies.

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.

Wafer-level Package Products :

We offer three types of wafer-level packages:

We offer various types of wafer-level packages:

wafer-level CSP;

SiPh and CPO;

Wafer-level CSP and WLFO are complementary technologies.

Customers can choose between the two package types as their die sizes shrink or grow.

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.

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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.

• SWIFT, also known as high-density fan-out, can either replace the laminate substrate with a thinner structure or reduce the complexity of the substrate by housing the dense interconnects in the SWIFT structure, allowing for a less expensive substrate that provides a high level of performance with a balanced cost structure.

SWIFT solutions enable high performance in a compact form factor that combines tiled processors, memory, I/O (input/output) die and other peripheral ICs.

• 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

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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.

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.

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• System Level Test:

System level test identifies defective SiP 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 SiP grows, system level testing becomes more important.

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:

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We believe that technology development is one of the keys to success in the semiconductor packaging and test industry.

Our research efforts focus on developing new packaging solutions and test services, as well as improving the efficiency and capabilities of our existing production processes.

By concentrating our research and development on our customers’ needs for innovative packaging solutions for increased performance, higher density, smaller size and lower cost, we gain opportunities to enter markets early and compete for new business.

A significant area of focus is on integrated multi-die solutions, including 2.5D, SWIFT and S-Connect.

These multi-chip modules and high-density WLFO solutions 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 and other chiplets into one packaged module.

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.

Another important priority is the development of wafer-level and panel-level packages for 2D and 3D implementations.

These 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.

Our development of Panel Level Fan Out (“PLFO”) technology will permit higher economies of scale for fan-out package devices manufactured on a panel versus wafer basis.

Another key area is developing highly integrated SiP modules, such as DSMBGA or double-sided molded land grid array packages, to reduce material and processing costs and minimize form factor for wearables and mobile devices.

We are also developing new applications for the automotive market using existing and 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.

• 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.

• 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.

Our research and development employees are based in Korea, Portugal, the United States and other locations in Asia.

• 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.

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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 office locations to ensure that we are aligned with their global operational and business requirements.

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.

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 U.S., Europe and Asia and the timing of flagship mobile device launches.

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.

Our customers include many of the largest semiconductor companies in the world.

Our customers include most of the world’s largest semiconductor companies.

Our ten largest customers accounted for 72% of our net sales in 2025.

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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 gold wire.

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.

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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.

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 gold wire, from a limited group of suppliers.

We work closely with our primary material suppliers to ensure consistent quality, availability and timely delivery.

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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 wirebonders, 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.

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.

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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.

The outsourced semiconductor packaging and test market is highly competitive, geopolitical trade tensions have increased competition from Chinese firms supporting a China-for-China supply chain.

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, such as TSMC, and electronic manufacturing service providers or contract electronics manufacturers, including Universal Scientific Industrial and Luxshare, which offer certain types of advanced packaging.

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.

10 unchanged sentences

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 U.S.

and other countries, and their durations vary depending on the jurisdiction in which each patent is filed.

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.

19 unchanged sentences

Our global workforce spans 12 countries, reflecting various cultures, backgrounds, ages, genders and ethnicities.

Our employees in France, Germany, the Philippines, Singapore, Taiwan and the United States are not represented by any union.

Certain employees at our factories in China, Japan, Korea, Malaysia, Portugal and Vietnam are members of a union, and we operate subject to collective bargaining agreements that we have entered into with these unions.

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.

8 unchanged sentences

current reports on Form 8-K;

Forms 3, 4 and 5 filed on behalf of directors and executive officers;

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 and Compensation Committee of our Board of Directors, our Code of Business Conduct, our Code of Ethics for Directors and other information and materials.

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.

Compared sentence by sentence after normalising whitespace, quotation marks, case and digits, so re-formatting and restated figures do not read as changed language. Wording changes appear as one removal and one addition. The current filing and the prior one are authoritative.

What changed 10-K

Item 1. Business