OSAT companies
As of 2026-10-04, wafergraph tracks 22 OSAT companies across 6 countries; ASE Technology hold monopoly or leader positions. The largest by market cap is ASE Technology at $123.5B, and the 16 priced companies total $214.3B. By revenue, the largest is ASE Technology at $20.6B, as of FY2025 (source: SEC).
Data as of 2026-10-04 · market caps from the daily wafergraph pipeline; unpriced companies are listed but not summed
22 companies in the OSAT part of the semiconductor & AI value chain — Outsourced semiconductor assembly and test (OSAT) companies package finished dies into the chips and modules that go into end products. As advanced packaging — chiplets, CoWoS, HBM stacking, and fan-out technologies — moves from niche to mainstream, OSATs have become strategic partners rather than commodity handlers. ASE Technology (which includes SPIL) is the world's largest OSAT; Amkor is a major player in advanced packaging in the Americas and Korea. TSMC and Samsung also offer advanced packaging in-house, competing directly with OSATs at the leading edge.
Subsegments
Market share
Top 13 OSAT companies by revenue
Ranked by whole-company revenue, most recent fiscal year reported by each company's own source. Companies with no sourced revenue figure are listed separately below, never estimated.
| Rank | Company | Revenue | FY & source | Market cap |
|---|---|---|---|---|
| 1 | ASE TechnologyNYSE:ASX | $20.6B | FY2025 · SEC | $123.5B as of 2026-10-04 |
| 2 | Amkor TechnologyNASDAQ:AMKR | $6.7B | FY2025 · SEC | $13.9B as of 2026-10-04 |
| 3 | JCET GroupSSE:600584 | $5.8B | FY2025 · Yahoo Finance | $17.2B as of 2026-10-04 |
| 4 | Tongfu MicroelectronicsSZSE:002156 | $4.2B | FY2025 · Yahoo Finance | $13.5B as of 2026-10-04 |
| 5 | Huatian TechnologySZSE:002185 | $2.6B | FY2025 · Yahoo Finance | $8.2B as of 2026-10-04 |
| 6 | Powertech Technology (PTI)TWSE:6239 | $2.4B | FY2025 · Yahoo Finance | $7.1B as of 2026-10-04 |
| 7 | King Yuan Electronics (KYEC)TWSE:2449 | $1.1B | FY2025 · Yahoo Finance | $11.9B as of 2026-10-04 |
| 8 | ChipMOS TechnologiesTWSE:8150 | $755M | FY2025 · Yahoo Finance | $2.8B as of 2026-10-04 |
| 9 | Chipbond TechnologyTPEx:6147 | $677M | FY2025 · Yahoo Finance | $5.2B as of 2026-10-04 |
| 10 | Orient Semiconductor (OSE)TWSE:2329 | $526M | FY2023 · Yahoo Finance | $930M as of 2026-10-04 |
| 11 | Greatek ElectronicsTWSE:2441 | $503M | FY2022 · Yahoo Finance | $2.2B as of 2026-10-04 |
| 12 | UnisemKLSE:5005 | $460M | FY2025 · Yahoo Finance | $1.8B as of 2026-10-04 |
| 13 | SFA SemiconKOSDAQ:036540 | $271M | FY2025 · Yahoo Finance | $1.4B as of 2026-10-04 |
Also in OSAT (revenue not disclosed)
Tracked, but no sourced revenue figure — never estimated.
- Deca Technologies — revenue not disclosed
- Hana Micron — revenue not disclosed
- Integra Technologies — revenue not disclosed
- LB Semicon — $250M market cap (as of 2026-10-04), revenue not disclosed
- Lingsen Precision — revenue not disclosed
- Nepes — $540M market cap (as of 2026-10-04), revenue not disclosed
- Sigurd Microelectronics — $3.9B market cap (as of 2026-10-04), revenue not disclosed
- UTAC Holdings — revenue not disclosed
- Walton Advanced Engineering — revenue not disclosed
Open the interactive OSAT view →
Cite as: wafergraph, “OSAT companies — list, suppliers & market position”, https://wafergraph.com/segment/osat/ (data as of 2026-10-04).
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