ASE Technology

日月光投控 / 日月光投資控股股份有限公司

Taiwan's largest outsourced semiconductor assembly and test provider, delivering the advanced packaging and testing services required to commercialize AI accelerators and high-performance computing chips.

TWSE: 3711
NYSE: ASX (ADR)
Profile as of September 13, 2026
#7 in the AsiaAI Tech Index
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ASE is a major beneficiary of AI's shift toward complex packages and intensive semiconductor testing, driving strong growth in its core ATM business. However, it operates in a capital-intensive, competitive, and geopolitically exposed supply chain where customer concentration is high but specific identities remain undisclosed.

Key figures

Revenue FY2025: NT$645.388 billion
Revenue growth FY2025: 8.4%
Operating margin FY2025: 7.9%
Net income FY2025: NT$40.658 billion
R&D spend FY2025: NT$32.852 billion (5.1% of revenue)
Capital expenditure FY2025: US$3.396 billion for equipment and US$2.1 billion for facilities
Market capitalization 2026-09-11: NT$2.72 trillion (US$85.78 billion) Estimate
LEAP advanced packaging revenue FY2025: US$1.6 billion
ATM segment revenue FY2025: NT$385.314 billion
Testing revenue growth FY2025: 32% year over year
EMS segment revenue FY2025: NT$257.193 billion

Overview

ASE Technology Holding Co., Ltd. is Taiwan's largest outsourced semiconductor assembly and test (OSAT) group and a major electronics manufacturing services provider through Universal Scientific Industrial. Formed in 2018 through the combination of Advanced Semiconductor Engineering and Siliconware Precision Industries, it operates separate legal entities for its ATM and EMS businesses.

It provides wafer bumping, flip-chip packaging, wafer-level packaging, fan-out, system-in-package, and leading-edge advanced packaging (LEAP) services. These services sit after wafer fabrication and before the packaged chip or electronics system reaches server, device, or equipment manufacturers.

The AI angle

ASE benefits from AI because AI accelerators and high-performance computing chips require complex advanced packaging and intensive testing. Its LEAP services, which cover leading-edge advanced packaging, reached US$1.6 billion in 2025, representing 13% of ATM revenue, and are expected by management to double to US$3.2 billion in 2026.

Testing revenue grew 32% in 2025, driven by turnkey and leading-edge test demand. ASE captures value from AI computing by converting customer wafers into deployable high-performance semiconductors, without fabricating the logic wafers itself. Computing represented 25% of ATM revenue in the fourth quarter of 2025.

Technology and moat

ASE's moat is its high-volume industrial execution, broad process portfolio, and established advanced-package qualification. It combines wafer bumping, flip-chip, system-in-package, substrate design, probe, test, and final assembly, allowing customers to use one group for multiple back-end processes.

Its scale supports a massive installed base of over 25,000 wirebonders and 7,300 testers. Furthermore, its Taiwan cluster proximity connects it closely to foundries and semiconductor design firms, creating a tightly integrated supply chain that is difficult for competitors to replicate quickly. Advanced packaging remains competitive, but customer qualification is product-specific, making established volumes sticky.

Five-pillar assessment

Scale and market position: Taiwan's largest OSAT group with massive installed capacity, generating NT$645.388 billion in 2025 revenue across its ATM and EMS businesses.
Technology and R&D: Broad portfolio spanning wafer-level packaging, flip-chip, system-in-package, and LEAP advanced packaging, supported by extensive testing capabilities.
Supply-chain centrality: Deeply integrated into the Taiwan semiconductor cluster, though specific upstream suppliers and downstream AI-chip customers remain undisclosed.
Financial momentum: Strong growth in ATM and testing revenue driven by AI demand, with LEAP services expected to double in 2026, offsetting EMS segment declines.
Governance and quality: Independent, professionally managed public company with transparent SEC reporting, though exposed to Taiwan cross-strait and export-control risks.

Supply chain and relationships

ASE depends on upstream suppliers for assembly, test, automation, materials, and facility equipment, though specific names are not publicly disclosed. Its output relies on customer-designed wafers and components.

Downstream, its top five ATM customers accounted for about 41% of ATM revenue in the fourth quarter of 2025, and its top five EMS customers represented about 70% of EMS revenue. Customer names are not publicly disclosed, but the concentration indicates reliance on major semiconductor designers and electronics brands.

Customers

Top five ATM customersApproximately 41% of ATM revenue in 4Q25
Top five EMS customersApproximately 70% of EMS revenue in 4Q25

Competitors

Amkor TechnologyInferredCompetes in outsourced semiconductor assembly, advanced packaging, and test
JCET GroupInferredCompetes in outsourced semiconductor assembly, advanced packaging, and test
Tongfu MicroelectronicsInferredCompetes in outsourced semiconductor assembly and test
Powertech TechnologyInferredCompetes in semiconductor assembly and testing
ChipMOS TechnologiesInferredCompetes in testing and packaging for selected semiconductor markets

Geopolitics and risk

ASE's headquarters and a substantial portion of its advanced packaging and testing capacity are in Taiwan, exposing it to cross-strait disruption risks. It is also subject to evolving United States and allied-country export controls on advanced chips and equipment, which can constrain customer demand, equipment deliveries, or China-linked operations.

While it has a global manufacturing footprint across Asia, the Americas, and Europe, its most advanced capabilities remain concentrated in Taiwan.

Risk matrix
Risk	Severity	Why it matters
Taiwan cross-strait disruption	High	A substantial portion of advanced packaging and testing capacity is in Taiwan.
Export controls on advanced chips	High	U.S. and allied controls can constrain customer demand and equipment deliveries.
Customer concentration	High	The top five ATM customers represent approximately 41% of ATM revenue.
Advanced-package capacity execution	High	Doubling LEAP revenue requires timely equipment, yield ramp, and customer qualification.
Semiconductor-cycle exposure	Medium	Exposed to cyclicality in communications, computing, automotive, and consumer markets.
Competitive pricing and qualification	Medium	Competitors and customer internal operations can pressure margins outside the leading edge.
EMS margin dilution	Medium	The EMS segment earns a much lower operating margin than the ATM business.
Debt-funded capacity expansion	Medium	Expanding facilities and equipment requires significant interest-bearing debt.

Governance and ownership

ASEH is an independent public holding company listed on the Taiwan Stock Exchange and the New York Stock Exchange. It is founder-led and professionally managed, with Jason C.S. Chang serving as chairman and principal executive officer.

The company files audited financial statements with the U.S. SEC and is not identified as state-influenced. It operates with substantial institutional ownership and transparent reporting, though specific beneficial ownership concentration is not detailed in the cited materials.

What to watch

Whether LEAP advanced packaging and test revenue reaches management's US$3.2 billion 2026 target.
Whether ATM revenue continues to outgrow the logic semiconductor market without sacrificing margins.
Whether ASE can add advanced packaging and leading-edge test equipment fast enough to support LEAP demand.
Whether EMS revenue stabilizes after the 5% FY2025 decline.
Whether the proportion of ATM revenue from computing continues to rise beyond 25%.
Whether export-control changes affect customer demand or China-linked manufacturing.

Recent developments

April 1, 2026Filed its FY2025 Form 20-F annual report with the U.S. Securities and Exchange Commission.
February 5, 2026Reported FY2025 consolidated revenue of NT$645.388 billion and net income of NT$40.658 billion.
February 5, 2026Management guided for LEAP services to double to US$3.2 billion in 2026.
December 31, 2025Ended FY2025 with 105,955 employees, 25,001 wirebonders, and 7,359 testers.

Coverage on AsiaAI.FYI

Infineon’s GaN Surge: How AI Data Centres Are Reshaping the Power Chip Supply Chain September 7, 2026
FaCTz’s 60GB/s GPU Compression: Why High-Performance Computing Sites Are Eyeing the Taiwan Tech August 23, 2026
ASE’s Silicon Valley Expansion: How a $29M Building Buy Secures U.S. Chip Packaging August 23, 2026

Guides that cover ASE Technology

About this profile

Compiled with AI-assisted research from company filings, market data, and published reporting as of September 13, 2026, then reviewed by AsiaAI.FYI. Figures marked Estimate are not company-reported. Check primary filings before relying on any number.

Confidence: B. Financial operating results, capacity figures, and segment performance are directly supported by company filings, while customer identity, specific upstream supplier identity, and exact AI-derived revenue rely on broader market context.

Main sources: FY2025 Form 20-F annual-report filing; SEC Form 6-K quarterly and full-year earnings releases; Company earnings presentation; Market-data sources.

All 59 sources

Position in the AI stack

The back-end manufacturing layer that packages and tests fabricated silicon into deployable AI accelerators and high-performance computing chips.

Legal name: ASE Technology Holding Co., Ltd.
Headquarters: Kaohsiung, Taiwan
Founded: 2018
Leadership: Jason C.S. Chang / 張虔生, Chairman and principal executive officer
Tien Wu / 吳田玉, Director and chief operating officer
Joseph Tung, Chief financial officer
Employees: 105,955 (2025-12-31)
Ownership: Publicly listed
Listings: TWSE: 3711
NYSE: ASX (ADR)
Business: Outsourced semiconductor assembly, test, and electronics manufacturing services
Sector: Electronic Components
Packaging, Test & Substrates
Website: aseglobal.com