[AI Infrastructure Dissection] ASE Technology Holding: Advanced Packaging, LEAP Strategy, and the AI Infrastructure Cycle

AI Infrastructure Briefing Series

ASE TECHNOLOGY HOLDING CO., LTD. (NYSE: ASX / TWSE: 3711)

Advanced packaging, the LEAP strategy, and the AI infrastructure cycle — Sources: SEC EDGAR (Form 20-F FY2025 · Form 6-K Q4 2025) · Amkor Technology 8-K FY2025 · SEMI WWSEMS · Reuters · S&P Dow Jones Indices · April 2026

 

The Five Things That Matter

A finished chip isn't a product yet. Before it can go into a server or a phone, someone has to cut it out of the wafer, protect it, wire it up, and test it. ASE Technology Holding does more of that job than any other company on Earth, and the AI boom just turned that once-boring corner of the chip business into one of its biggest bottlenecks. Here's what's actually going on.

 

1. ASE is the company that finishes the chip after the fab is done with it. A wafer full of chips isn't sellable on its own — it has to be diced, packaged, and tested first. That's ASE's whole business, done at a scale nobody else matches: $20.8 billion in revenue in 2025, up 11.8% from the year before.

 

2. Its advanced-packaging unit almost tripled in a year. ASE calls this business LEAP. What it actually does is glue an AI chip and its memory together into one tightly packed unit, which is what lets GPUs talk to memory fast enough to keep up with today's AI models. Revenue from that unit went from $0.6 billion in 2024 to $1.6 billion in 2025, and management wants to double it again, to $3.2 billion, in 2026.

 

3. It's spending heavily to stay ahead of everyone else. ASE put roughly $5.5 billion into new equipment and facilities in 2025 alone — about 1.4 times what the business earned in cash that year — which is roughly double what its closest rival, Amkor, plans to spend in all of 2026.

 

4. Somehow, profit margins are going up while spending is too. The core packaging-and-testing business earned a 23.8% gross margin in 2025, and management expects 24–25% in the first quarter of 2026 — normally the slowest quarter of the year. The shift toward AI work is more than making up for the usual seasonal dip.

 

5. Three risks are worth watching. About two-thirds of ASE's employees, and nearly all of its most advanced packaging capacity, are in Taiwan. A handful of AI customers probably account for most of the LEAP boom, so if one of them changes its order, ASE feels it. And all this spending assumes chip demand keeps climbing through 2027 — but the industry's own forecasters expect growth to slow down from here, not speed up.

 

Key Metrics at a Glance

FY2025 Revenue

$20.8B

 

+11.8% year-over-year

Packaging & Test Revenue

$12.3B

 

+20.0% year-over-year

LEAP Revenue FY2025

$1.6B

 

vs $0.6B in FY2024

FY2025 Total Capex

~$5.5B

 

vs ~$1.9B in FY2024

Packaging & Test Margin

23.8%

 

up from 22.9% in FY2024

FY2026 LEAP Target

$3.2B

 

double FY2025, per guidance

Sources: ASE Technology Holding Co., Ltd., Form 6-K, Q4 2025, filed February 5, 2026; Form 20-F, FY2025. SEC EDGAR CIK 0001122411. The headline $20.8B figure uses the exchange rate from the 6-K filing (NT$31.06 = US$1); a slightly different figure appears elsewhere in ASE's own reporting because the 20-F uses a different rate (NT$31.37 = US$1) from an earlier point in the year. Both numbers are correct — the gap is just currency math, not a correction to the business.

I. Three Years of Rebuilding the Business

ASE has spent the last three years moving away from lower-margin contract manufacturing and toward the harder, more technical work of packaging and testing chips — especially the advanced kind that AI accelerators need. The 2025 numbers show that shift paying off. (ASE Technology Holding 2026b, Item 5)

 

ASE actually runs two different businesses side by side. One is packaging and testing chips, which the company calls ATM (short for Assembly, Test and Measurement) — this is the core, high-margin business this briefing is mostly about. The other is EMS, contract manufacturing of finished circuit boards and electronics, run through a subsidiary called USI Group. It's a lower-margin, more commoditized business, and it's shrinking as a share of ASE's total revenue.

 

Segment Performance — FY2025 vs FY2024

 

Segment	FY2025 Revenue	YoY Growth	Share of Total
ATM (Packaging & Test)	NT$385,314M	+20.0%	59.7%
— of which Packaging	NT$308,342.6M (US$9,829.2M)	+17.8%	—
— of which Testing	NT$71,900.2M (US$2,292.0M)	+31.8%	18.5% of ATM
EMS (Electronics Manufacturing)	NT$257,192.7M	−5.2%	39.9%

Source: ASE Technology Holding Co., Ltd., Form 20-F FY2025, Item 5. SEC EDGAR. ATM's share of total company revenue rose from 53.5% in 2023 to 59.7% in 2025.

In total, ASE brought in NT$645.4 billion (about US$20.6 billion) in 2025, up 8.4% from the year before in Taiwan-dollar terms. (ASE Technology Holding 2026b, Item 5) Testing was the standout: its share of ATM revenue climbed from 15.8% in 2023 to 18.5% in 2025. That's a sign customers aren't just paying ASE to assemble chips anymore — they're paying more for the testing that catches a flaw before it ends up in a data center. (ASE Technology Holding 2026a; 2026b, Item 5)

 

Margins Climbed Even With All This Spending

Gross margin — what's left of revenue after paying for materials and direct production costs — rose 140 basis points (a basis point is a hundredth of a percentage point) to 17.7% companywide, and to 23.8% within ATM alone, up from 22.9% the year before. That improvement came from selling a richer mix of higher-value work and running factories more efficiently. (ASE Technology Holding 2026b, Item 5)

 

Operating margin went from 6.6% to 7.9%. Net income attributable to shareholders rose 25.3% to NT$40,658 million, which works out to NT$9.37 per share, or US$0.601 for every American depositary share — the U.S.-listed certificate that stands in for shares of a foreign company, since ASE's own shares trade in Taiwan rather than New York. (ASE Technology Holding 2026b, Item 5)

 

None of this was a fluke — it's just what happens when the product mix shifts toward LEAP. Raw material costs dropped from 51.5% to 48.4% of revenue, easily covering the higher labor costs (10.8% to 11.3%) and depreciation (9.1% to 9.6%) that come with the massive equipment spending described in Section III. (ASE Technology Holding 2026b, Item 5)

 

ASE also spent NT$32,851.5 million (US$1,047.2 million) on R&D in 2025 — 5.1% of revenue — and employs 14,258 people in R&D roles. The customer mix shows where that money is going: computing customers, the ones building AI chips and memory, went from 18.1% to 24.0% of ATM revenue in three years, while telecom customers slipped from 50.8% to 45.8%. (ASE Technology Holding 2026b, Item 4 & Item 6)

 

By year-end, ASE's EBITDA — the cash a business earns before interest, taxes, and depreciation are subtracted, a common way to compare how much a capital-heavy company like this actually generates — reached NT$126,011 million, against total assets of NT$889,333 million and a net debt-to-equity ratio of 0.46. That's a conservative balance sheet for a company spending this aggressively. (ASE Technology Holding 2026a)

 

II. What "Packaging" Actually Means, and Why It's Suddenly a Big Deal

Most people picture chipmaking as etching circuits into silicon — that's the "front end," and it's what gets all the attention because that's TSMC's job. But a finished wafer isn't a product. The chips on it are still fragile, unprotected, and unable to connect to anything. Turning them into something you can actually put in a server is a separate industry, called back-end packaging and testing, or OSAT (Outsourced Semiconductor Assembly and Test). ASE is the biggest company in the world that does this.

 

From bare silicon to a working AI chip: the four steps

 

1. The chip arrives bare. ASE receives finished, unpackaged chips straight from a foundry like TSMC — just raw silicon, with no protective shell and no way to connect to anything yet.

 

2. It gets packaged. This is the part that matters most for AI: stacking a GPU and its memory chips vertically, packed as close together as possible, so data doesn't have to travel far. That short distance is the whole point — it's what lets an AI chip actually use the memory bandwidth it needs.

 

3. Several parts become one system. Multiple components get combined into a single sealed package, which helps with both power efficiency and getting rid of heat.

 

4. Everything gets tested. Before shipping, the finished chip goes through exhaustive testing to make sure it works perfectly — a single bad chip in a data center full of them is an expensive problem to find later.

 

ASE calls its advanced-packaging business LEAP, short for Leading-Edge Advanced Packaging and Testing. Under that one brand sit a few different techniques: combining chips that do different jobs into a single package, stacking chips vertically instead of laying them flat, and testing high-bandwidth memory (HBM) — the fast, stacked memory that sits right next to an AI accelerator.

 

LEAP Revenue, 2023 to 2026 (USD billions)

 

Sources: ASE Technology Holding 6-K Q4 2025, "2025 Recap" (Feb 5, 2026); Reuters (Lee 2026), Feb 5, 2026. The 2026 figure is company guidance, not an actual result yet.

Three years ago, LEAP was a rounding error — about $250 million, or roughly 2% of ATM revenue. It grew to $600 million in 2024, still just 6% of ATM. Then in 2025 it jumped to $1.6 billion, 13% of ATM revenue, nearly tripling in twelve months. (ASE Technology Holding 2026a, "2025 Recap") Management isn't slowing down: the guidance for 2026 is to double that again, to $3.2 billion, split roughly 75% packaging and 25% testing. That figure was confirmed directly on the February 5, 2026 earnings call. (Lee 2026)

 

"LEAP services reached US$1.6 billion, accounting for 13% of ATM revenue, up from US$0.6 billion in 2024. Testing business grew 36% YoY in 2025, supported by expanding turnkey and leading-edge test. Machinery capex totalled US$3.4 billion, whereas buildings, facilities and automation capex was US$2.1 billion in 2025, mainly driven by LEAP services and testing investments."

 

— ASE Technology Holding Co., Ltd., Form 6-K Q4 2025 Earnings Release, "2025 Recap," February 5, 2026 (ASE Technology Holding 2026a)

 

The Work Itself Is Getting Harder — and Better Paid

Type of Packaging Work	Q1 2024	Q4 2025
Advanced packaging (AI/HBM-related)	43%	49%
Standard wire bonding (older, simpler method)	30%	24%

Source: ASE Technology Holding 6-K Q4 2025. SEC EDGAR.

For decades, the industry made chips faster mainly by shrinking transistors. That approach is running out of room, so the new gains come from a different place: combining several chips — a CPU, a GPU, HBM memory — into one tightly integrated package. The Semiconductor Industry Association put total worldwide chip sales at $791.7 billion in 2025, and a growing share of that value now depends on exactly the kind of assembly work ASE has been refining for decades. (ASE Technology Holding 2026b, Item 4, citing SIA)

 

ASE's relationship with TSMC is complicated. TSMC is both a partner and, increasingly, a rival: ASE's own filings call TSMC a "strategic alliance," but they also flag TSMC's in-house packaging technology, called InFO, as a genuine competitive threat. That makes sense — TSMC is the largest, richest foundry in the world, and it has every incentive to move into packaging itself rather than hand that revenue to ASE. (ASE Technology Holding 2026b, Item 4, "Competition") ASE's answer is to stay too far ahead to catch: $1.05 billion in R&D in 2025, joint development work with top Asian suppliers, and the spending spree covered next.

 

III. Betting Big on Equipment — and the Data Backing That Bet

ASE spent $3.4 billion on new machinery in 2025, up from about $1.9 billion the year before, plus another $2.1 billion on buildings, facilities, and automation — roughly $5.5 billion total, or about 1.4 times the cash the company generated that year. (ASE Technology Holding 2026a) Spending built up gradually and then eased off: $228 million in the first quarter of 2024, climbing to $992 million by the second quarter of 2025, then settling back to $733 million by the fourth quarter as the new equipment came online. That pattern — a spending peak followed by a pullback as capacity ramps up — usually marks a company moving from "building the factory" to "running the factory," and it lines up with ATM's operating margin hitting 14.7% in the fourth quarter, the best of the whole period.

 

Management isn't done spending, either — its 2026 guidance explicitly promises to keep "stepping up capital expenditure… to support the multi-year growth." For comparison, Amkor Technology, ASE's closest publicly traded rival, has guided to just $2.5–3.0 billion in capex for all of 2026, despite running a packaging business roughly one-third ASE's size. (ASE Technology Holding 2026a; Amkor Technology 2026)

 

This Isn't Just ASE Talking Its Own Book

SEMI, the industry association that tracks chip-equipment sales across the whole world, backs up the story independently. Global equipment billings hit $135.1 billion in 2025, up 15% from $117.1 billion the year before. Back-end equipment — the machines used for packaging and testing, ASE's world — grew even faster: test equipment sales jumped 55%, and packaging equipment rose 21%. (SEMI 2026)

 

Taiwan alone spent $31.5 billion on equipment, up 90% year-over-year and the biggest single-country jump anywhere, which SEMI credited to "AI- and HPC-driven capacity expansion." SEMI's president and CEO, Ajit Manocha, put it plainly: the numbers show "the scale and urgency of the industry's buildout as AI accelerates demand for leading-edge logic, advanced memory and high-bandwidth architectures." (SEMI 2026)

 

Global Semiconductor Equipment Spending, Actual and Forecast (USD billions)

 

Sources: SEMI WWSEMS Annual Report, April 2026 (actuals); SEMI Year-End Equipment Forecast, December 2025 (2026–2027 projections).

Looking further out, SEMI expects total equipment spending to reach $145 billion in 2026 and $156 billion in 2027, with packaging equipment growing 9.2% and 6.9% in those two years — slower than 2025's 21%, but still growing. (SEMI 2025a) That's a useful sanity check on ASE's own spending: an outside forecaster, using its own data, expects roughly the same kind of growth ASE is betting on. When a company's spending plan matches what independent analysts already expect the whole industry to do, that's a much safer bet than a company spending ahead of where the market is actually going.

 

IV. The Competition, the Customers, and the Sustainability Scorecard

ASE vs. Amkor — Most Recent Full Year

 

ASE's figure covers its ATM (packaging & test) segment only, which is the fair comparison to Amkor's whole business. Sources: ASE Technology Holding 6-K Q4 2025; Amkor Technology 8-K FY2025.

The clearest yardstick for ASE's packaging business is Amkor Technology (Nasdaq: AMKR), which calls itself the largest U.S.-headquartered OSAT company. Amkor made $6.71 billion in 2025, up 6% from the year before, with a 14.0% gross margin and R&D spending of $166.7 million — about 2.5% of sales. (Amkor Technology 2026)

 

Put the two side by side using nothing but their own SEC filings, and ASE's packaging business alone (about $12.3 billion) is roughly 1.8 times Amkor's entire company. ASE's gross margin, at 23.8%, beats Amkor's by nearly 10 percentage points — a gap big enough to fund ASE's much larger R&D and equipment budgets on its own. (ASE Technology Holding 2026a; Amkor Technology 2026)

 

Why Customers Don't Switch Suppliers Easily

A handful of customers drive most of ASE's business — five of them made up 46.5% of 2025 revenue, and one has been above 10% for three years running. (ASE Technology Holding 2026b, Item 4) That's not an accident of scale; it's built into how the business works. Before a customer can place large orders at a given ASE facility, its chips have to go through a qualification process — testing chips also need a separate step called correlation testing — that typically takes several weeks and sometimes longer. Once a customer has gone through that with ASE, repeating the whole process somewhere else means real delays and real risk to their supply chain. Most customers just don't bother switching mid-production. (ASE Technology Holding 2026b, Item 4)

 

Spreading Out Beyond Taiwan, Slowly

Where ASE's customers are based tells you where the LEAP demand is coming from. U.S. customers went from 63.6% of revenue in 2023 to 56.7% in 2025, while Taiwan-based customers grew from 12.1% to 18.0% — mostly fabless AI chip designers plugged into TSMC's supply chain. ASE calls its diversification effort "Taiwan Plus One": between 2023 and 2025 it added 1,559 jobs in Vietnam, going from 746 employees to 2,305, and it also runs facilities in Korea, Malaysia, Mexico, and Europe. (ASE Technology Holding 2026b, Item 4 & Item 6)

 

Sustainability: One of the Chip Industry's Better Report Cards

On the environmental and governance side, ASE has made the Dow Jones Sustainability Index World list for nine years straight — one of just 8 out of 71 companies assessed in the semiconductor equipment category in 2024. It also holds an "A" rating from MSCI, eight years of CDP climate recognition, a 2050 net-zero emissions target, and already runs 84% of its manufacturing sites on renewable power. (ASE Technology Holding 2024; S&P Dow Jones Indices 2024)

 

V. Five Things That Could Go Wrong

1. Almost everything important sits in Taiwan

64% of ASE's 105,947 employees — 67,870 people — work in Taiwan, and its two most advanced facilities, in Kaohsiung and Taichung, would take years to rebuild anywhere else. ASE's own risk disclosures name cross-strait tension and shifting U.S. trade policy as real threats. The "Taiwan Plus One" plan is still small: Vietnam accounts for just 2.2% of the workforce, and no other country has anything close to LEAP-level advanced packaging yet. (ASE Technology Holding 2026a; 2026b, Item 6)

2. The LEAP boom probably rests on a handful of customers

Five customers already make up 46.5% of ASE's revenue, and LEAP's demand — driven by AI accelerators and HBM — almost certainly comes from an even smaller group of hyperscalers and chip designers than that. If one big LEAP customer redesigns its chip on a different timeline, or moves work elsewhere, the hit to ASE's revenue and margins would be outsized compared to how the rest of the business is spread out. (ASE Technology Holding 2026b, Item 4)

3. The spending has to keep paying off

ASE's factory and equipment base grew 34.8% in a single year, to NT$421,115 million, funded by cash from operations plus new borrowing — and management wants to spend even more in 2026. But SEMI's own forecast has packaging-equipment growth slowing from 21% in 2025 to 9.2% in 2026 and 6.9% in 2027. That's the industry's own experts saying the boom is normalizing. If demand comes in even softer than that, ASE would be stuck with a much bigger cost base and not enough orders to fill it — the kind of mismatch that hits margins hard. (ASE Technology Holding 2026a; SEMI 2025a)

4. China is coming for the easier work

China spent $49.3 billion on chip equipment in 2025 — the single biggest national market in the world — much of it flowing to government-backed domestic packaging companies. They haven't shown they can do LEAP-level advanced work yet, so ASE's top-end business looks safe for now. But in ordinary packaging — plain wire bonding, basic flip-chip work, the stuff that's still most of ASE's volume — Chinese competitors are already undercutting on price, and that pressure is only going to grow. (SEMI 2026)

5. The other half of the business is shrinking and politically exposed

ASE's EMS business — contract manufacturing, run through USI Group — shrank 5.2% in 2025 to $8.2 billion, still nearly 40% of total revenue but earning only a 9.2% margin. It employs 19,020 people in mainland China and serves telecom and consumer-electronics customers who are directly in the path of U.S.–China trade friction. ASE's own filings list export controls and tariffs as material risks to this part of the business. (ASE Technology Holding 2026a; 2026b, Item 5, Safe Harbor Notice)

VI. What Comes Next

Management expects revenue to dip 5–7% quarter-over-quarter in the first quarter of 2026, from Q4 2025's NT$177,915 million — a normal seasonal slowdown, nothing unusual. Gross margin should shrink 50–100 basis points and operating margin 100–150 basis points, also typical for the season. The one number that stands out: ATM gross margin is guided at 24–25%, actually higher than the 23.3% ASE posted in the first quarter of 2025. That's the clearest evidence yet that the shift toward LEAP is strong enough to beat the usual winter slowdown. (ASE Technology Holding 2026a, "First Quarter 2026 Outlook")

 

• The slow season isn't hurting like it used to. Revenue will dip a bit in Q1 2026, as it always does, but margins are guided to stay above where they've historically been thanks to the mix shift toward LEAP. (ASE Technology Holding 2026a)
• LEAP is supposed to double again. Management wants to take LEAP from $1.6 billion to $3.2 billion in 2026 — about three-quarters packaging, one-quarter testing. (Lee 2026)
• This isn't just ASE being optimistic about itself. SEMI's independent forecast for the whole industry points the same direction through 2027, which backs up ASE's guidance from outside the company. (SEMI 2025a)

Management's own words sum up the pitch: it expects the "revenue uptrend to continue into 2026 and beyond, driven by leading-edge solutions and broad-based semiconductor demand related to AI proliferation and general market recovery." (ASE Technology Holding 2026a, "2026 Outlook")

 

Source Credibility and Verification

Source	Grade	Evidentiary Note
ASE Technology Holding, Form 20-F FY2025	Tier 1 — A+	Annual statutory filing under the Securities Exchange Act; IFRS; SOX 404(b) attested; user-supplied document
ASE Technology Holding, Form 6-K Q4 2025	Tier 1 — A+	Statutory foreign-issuer reporting; signed by CFO Joseph Tung; fetch-verified from SEC EDGAR
Amkor Technology, Form 8-K FY2025	Tier 1 — A+	Mandatory 8-K earnings disclosure; U.S. GAAP; fetch-verified from SEC EDGAR
SEMI, WWSEMS Annual Report, April 2026	Tier 1-equivalent — A	Primary institutional statistical series compiled from OEM and SEAJ member submissions; fetch-verified via PRNewswire
SEMI, Year-End Equipment Forecast, Dec 2025	Tier 1-equivalent — A	Semi-annual OEM-perspective forecast; same WWSEMS methodology; fetch-verified via PRNewswire
Reuters (Lee, Wen-Yee), February 5, 2026	Tier 2 — A	Named byline and editor credit; relay-verified via Global Banking & Finance Review
ASE Technology Holding, DJSI Press Release, Dec 2024	Primary Corporate — A-	Official company press release; fetch-verified from aseglobal.com
S&P Dow Jones Indices, DJSI World Components List 2024	Tier 3 — A-	Official index constituent list; ASE named explicitly; search-retrieved, direct fetch not performed

Disclaimer. This briefing is an informational analysis based on publicly available primary sources and does not constitute investment advice. All figures are sourced from the referenced SEC disclosures and are subject to revision by subsequent filings. NT$-to-US$ translations use the exchange rates stated in the respective source filings.

Sources: SEC EDGAR (ASX / 3711, AMKR) · SEMI WWSEMS · Reuters · S&P Dow Jones Indices · Published April 2026

Bibliography

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ASE Technology Holding Co., Ltd. 2024. "ASE's Sustainability Efforts Receive International Recognition with a Ranking on the Dow Jones Sustainability Indices for the Ninth Year in a Row." Press Release, December 24, 2024. aseglobal.com/press-room/2024-djsi

ASE Technology Holding Co., Ltd. 2026a. Form 6-K: Fourth Quarter and Full Year 2025 Earnings Release. Filed February 5, 2026. Commission File No. 001-16125. Signed: Joseph Tung, CFO. sec.gov/Archives/edgar/data/0001122411/000095010326001662/dp241167_6k.htm

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SEMI. 2025a. "Global Semiconductor Equipment Sales Projected to Reach a Record of $156 Billion in 2027, SEMI Reports." Year-End Total Semiconductor Equipment Forecast — OEM Perspective, December 16, 2025. prnewswire.com (SEMI 2027 forecast)

SEMI. 2026. "SEMI Reports Global Semiconductor Equipment Billings Reached $135 Billion in 2025, Up 15% Year-on-Year." WWSEMS Annual Report, April 7, 2026. prnewswire.com (SEMI WWSEMS 2026)