ASE Technology Holding Co., Ltd.

Overview

ASE Technology Holding Co., Ltd. is a Taiwan-headquartered semiconductor manufacturing services company. Its core business includes semiconductor assembly and packaging, testing, wafer sort and final testing, and substrate design and manufacturing; its broader operations also include electronics manufacturing services (EMS). Its packaging portfolio spans technologies such as flip-chip, chip-scale, 3D and stacked-die packages, serving applications that include IoT, servers and automotive.[1]+2

The company has a broad international footprint, with operations and subsidiaries across Taiwan, China, Japan, Korea, Malaysia, Singapore, the Philippines and the United States. ASE Technology Holding states a mission of combining the strengths of its member companies to strengthen research and development and competitiveness, integrate the supply chain, and expand its global market presence.[1]+2

For 2025, operating revenue was NT$645.4 billion (US$20.57 billion); ASE’s official inclusive-workplace page reports 86,000 employees. ASE Inc., a key operating company, was established in 1984.[6]+2 [1]+6

Products & services

ASE Technology Holding’s packaging products include wafer-level chip-scale packages (aCSP), flip-chip CSP/BGA packages, flip-chip PiP/PoP, hybrid flip-chip and wire-bond packages, advanced single-sided substrate (aS3), high-bandwidth PoP, integrated passive devices and SESUB. Its flip-chip and wafer-bumping processes use solder bumps across the die surface in place of wire-bond interconnects, supporting higher I/O density.[8][9]

Advanced packaging offerings include fan-out wafer-level packaging (FOWLP), fan-out PoP, fan-out SiP, FOCoS and FOCoS-Bridge, 2.5D/3D IC packaging, and co-packaged optics. FOCoS integrates a fan-out flip-chip package with a high-pin-count BGA substrate; FOCoS-Bridge embeds silicon bridges in fan-out redistribution layers for chiplet interconnects. The company also describes side-by-side dies on silicon interposers for 2.5D packaging and stacked active dies for 3D packaging.[10]+3

Testing services span wafer probing, engineering and final testing, and customized system-level testing. Disclosed capabilities include testing for high-performance computing, millimeter-wave, SiP, silicon photonics and optical sensor modules, as well as high-power cooling/package test handlers and burn-in. Its electronics manufacturing services include PCBA/SMT, system assembly, and box-build, module and finished-product assembly.[14]+4

For 2025, external-customer revenue was NT$308.3 billion from Packaging (47.8%), NT$71.9 billion from Testing (11.1%), and NT$257.2 billion from EMS (39.9%); Others contributed NT$8.0 billion (1.2%). These are segment-level figures, not revenue shares for individual products.[3] [8]+15

Geographic presence

ASE Technology Holding’s 2025 filing identifies semiconductor packaging and testing operations in Taiwan, South Korea, China, Singapore and Malaysia, with Japan operations also covering marketing and sales, and U.S. subsidiaries providing testing and sales-related support [19][20]. Its wider group footprint includes EMS and related manufacturing or design operations in China, Taiwan, the United States, Mexico, Japan and Vietnam, as well as automotive-electronics operations in Germany and Hungary and entities in France [21]. The company’s facilities information also identifies sites in Taiwan, China, Korea, Japan, Malaysia and Singapore [22].

ASE reported more than 100,000 employees worldwide as of December 2025 [5]. Its published workforce information says over 70% are based in Taiwan and nearly 20% in China [23]. The 2025 filing reports revenue by business line rather than geography, so it does not provide a country or regional revenue mix in the cited segment disclosure [24]. [19]+9

Business segments

ASE Technology Holding Co., Ltd. reports four business segments: Packaging, Testing, EMS, and Others. For FY2025, the latest completed fiscal year, their shares of external-customer revenue were approximately 47.8%, 11.1%, 39.9%, and 1.2%, respectively. The percentages are calculated from the reported segment revenues; “Adjustments and Eliminations” is a reconciliation category, not a business segment.[3] Packaging focuses on semiconductor packaging, while Testing includes wafer sort and final testing.[1] EMS includes module, board, and system assembly and testing activities.[25] The cited segment disclosures do not specify a separate business focus for Others.

As a current-year reference, ASE’s Q2 2026 results reported rounded revenue mix of 52% Packaging, 13% Testing, 34% EMS, and 1% Others; these are quarterly, not full-year, proportions.[26] [3]+6

Company history

ASE Technology Holding traces its roots to two semiconductor companies founded in Taiwan in 1984: Advanced Semiconductor Engineering (ASE), established by brothers Jason and Richard Chang, and Siliconware Precision Industries (SPIL), established in May. ASE listed in Taiwan in 1989 and expanded its packaging and testing operations over the following decades, including through the acquisition of NEC Electronics’ packaging and testing operation in Japan in 2004.[27]+2

ASE acquired Universal Scientific Industrial (USI) in 2010, broadening its operations into electronics manufacturing services. After earlier takeover efforts, ASE and SPIL combined under ASE Technology Holding: the holding company acquired all outstanding shares of both businesses on April 30, 2018, when their shares were delisted and the new company began trading in Taiwan.[27][29] In 2020, USI Shanghai completed its acquisition of Asteelflash, extending the group’s electronics manufacturing operations.[30] [1]+4

Sources

• ASE Technology Holding Co., Ltd. — Full financial report (2025 Y)
  18 citations

  [1][2][3][4][6][8][9][10][14][15][16][17][19][20][21][24][25][29]
• www.aseglobal.com[5]
• www.aseglobal.com[7]
• ase.aseglobal.com[11]
• ase.aseglobal.com[12]
• ase.aseglobal.com[13]
• ase.aseglobal.com[18]
• ase.aseglobal.com[22]
• www.aseglobal.com[23]
• www.sec.gov[26]
• ase.aseglobal.com[27]
• www.spilglobal.com[28]
• ir.aseglobal.com[30]