Amkor Technology is the world's largest U.S.-headquartered outsourced semiconductor assembly and test (OSAT) company. Amkor does not design or fabricate chips — it provides the packaging and testing services that come after wafer fabrication, turning bare silicon wafers into finished, tested semiconductor devices. Semiconductor packaging physically protects the chip, provides electrical connections to a circuit board, and manages heat dissipation. Amkor's customers — fabless chip designers, integrated device manufacturers, OEMs, and foundries — send Amkor their fabricated wafers, and Amkor handles bumping, dicing, assembly, and testing. Apple and Qualcomm are Amkor's two largest customers. Amkor organizes its services into two categories: Advanced Products (~83% of revenue), which uses flip chip interconnect technology for higher-performance packages including flip chip BGA, wafer-level packages, and System-in-Package (SiP) modules; and Mainstream Products (~17% of revenue), which uses simpler wirebond technology for analog, power, and automotive devices. Amkor charges fees for packaging and test services, with revenue driven by volume, product mix, and pricing. The business is capital-intensive and highly sensitive to factory utilization — margins compress sharply when volumes fall below capacity. Amkor's growth strategy centers on its proprietary HDFO (high-density fan-out) advanced packaging platform, which targets AI and high-performance compute applications, geographic expansion including a new advanced packaging campus in Chandler, Arizona, and deep partnerships with foundries and fabless customers to co-develop next-generation packaging technologies.