Amkor Technology, Inc. (AMKR)

Amkor packages and tests chips that other companies design and make. It describes itself as the world's largest US-headquartered outsourced semiconductor assembly and test provider, or OSAT. Customers send it finished wafers, which generally remain their property, and Amkor bumps, probes, thins, packages and tests the chips and ships them on. It works for integrated device makers, fabless chip designers, electronics makers and contract foundries. 17181920

How it operates

Amkor packages and tests chips that other companies design and make. It describes itself as the world's largest US-headquartered outsourced semiconductor assembly and test provider, or OSAT. Customers send it finished wafers, which generally remain their property, and Amkor bumps, probes, thins, packages and tests the chips and ships them on. It works for integrated device makers, fabless chip designers, electronics makers and contract foundries. 17181920

Its customers include most of the world's largest chip companies, and the ten largest took 72% of 2025 net sales. Direct sales to Apple made up 29.8% of net sales and to Qualcomm 11.1%. By end market, communications (smartphones and tablets) made up 46%, computing (data center, infrastructure, PCs and storage) 20%, automotive, industrial and other 19%, and consumer devices 15%. By the location of customers' headquarters, the United States accounted for 65.6% of net sales, Europe, the Middle East and Africa 12.7%, the rest of Asia-Pacific 10.9% and Japan 10.8%. 21222324

It makes everything in its own plants, almost all in Asia: factories in Korea, the Philippines, Japan, China, Taiwan, Malaysia and Vietnam, plus one in Portugal, 12,633,000 square feet in all, with executive offices in Arizona and Singapore. Korea is the core, with 4,481,000 square feet, its main research and development center and more than half its plant and equipment by value. A factory in Vietnam opened in 2024, and in 2025 construction began on the first phase of a facility in Arizona of about 1.8 million square feet, where manufacturing is expected to begin in the first half of 2028. 25262728293031

Materials are its largest cost, 55.2% of net sales in 2025, against 10.4% for labor and 8.7% for depreciation. The main ones are laminate substrates, ICs, capacitors, leadframes and bonding wires, mostly from a limited group of suppliers; its core machines are wire bonders, die bonders, chip shooters and die attach, with testers, handlers and probers for test. It reports in US dollars, the functional currency of all its subsidiaries except those in Japan, which use the yen. 323334353637

The specifics

Its technology lies in how chips are joined and stacked: flip chip, wafer-level packaging, high-density fan-out (its SWIFT and S-Connect), and 2.5D packages that use silicon interposers to put high-bandwidth memory and graphics processors in one package. It also builds advanced system-in-package modules, several chips and components in one small package for phones, wearables and cars, which brought in about 3,080 million dollars in 2025, and it is developing co-packaged optics and copper hybrid bonding. It holds patents but says it is not materially dependent on any one patent or technology. 383940414243

It names its main rivals as ASE Technology, JCET Group and Powertech Technology, along with contract foundries and electronics manufacturers that offer some advanced packaging and its own customers' in-house capacity. It says trade tensions have increased competition from Chinese firms supporting a China-for-China supply chain. 4445

Governments shape where it builds and what it keeps. The Commerce Department awarded up to 407 million dollars of CHIPS Act funding for the Arizona Facility, tied to construction and production milestones and restrictions on certain activities, and its subsidiaries in Korea, Singapore and Vietnam run under conditional reduced tax rates that rise as they expire. Past deals still surface: in 2025 it received 72.8 million dollars from insolvency payments tied to its May 2017 purchase of Nanium, and remitted 40.4 million of it to the former owners. 464748

What drives growth, line by line

Advanced Products. 5.6 billion dollars, 82.8% of 2025 net sales, up 7.4%. The line covers flip chip, memory and wafer-level packaging and the tests that go with them, where data center, AI and premium phone work sits; its share of sales has risen from 77.4% in 2023. 244950

Mainstream Products. 1.2 billion dollars, 17.2% of net sales, up 0.8%: wirebond packages, power device packaging and their tests, down from 22.6% of sales in 2023. 244950

Net sales rose 6.2% to 6.7 billion dollars. The filing credits higher sales in all end markets: computing up 16% on AI-related PC devices and networking infrastructure, automotive and industrial up 8% on advanced content for driver-assistance systems, consumer up 9% and communications up 1% on wearables and premium smartphones. Gross margin slipped to 14.0% from 14.8% on higher overhead and pay, and the ramp of the Vietnam factory held it back. 5152535455

The quarterly report for the three months to June 30, 2026 shows a faster pace: net sales up 25.6% on a year earlier, with communications up 32%, automotive and industrial up 35% and computing up 23% on data center strength, and gross margin up to 16.8% from 12.0% on fuller factories. 565758

What comes next, in the company's own words: capital spending of about 2.5 billion to 3.0 billion dollars in 2026, up from 2025 mainly for the Arizona Facility. 59

The read's section on the people who run it is on the People tab.

What the desk infers Inferred

1. Inferred

   Much of Amkor's advanced system-in-package business is most likely done for Apple, so its largest product family and its largest customer largely overlap.

   Because

   • Direct sales to Apple made up 29.8% of 2025 net sales. 21
   • Advanced system-in-package modules brought in about 3,080 million dollars in 2025, close to half of net sales. 4149
   • Those modules are found in smartphones and tablets, wearables and other devices. 42
   • Communications (smartphones and tablets) made up 46% of sales, and the company claims a strong position across multiple device functions in premium and high-tier smartphones. 2360
   Confidence 55 of 100Wrong if A filing showing that Apple buys mainly flip chip or wafer-level packages rather than system-in-package modules, or that most system-in-package sales go to other customers.
2. Inferred

   Amkor is American by headquarters and by customers but Korean by plant: its manufacturing weight sits in Korea while most of its sales are booked with US-headquartered companies.

   Because

   • Korea holds more than half of its net plant and equipment by value and 4,481,000 of its 12,633,000 square feet. 2725
   • Its main research and development center is in Korea. 28
   • Only about 1% of its 30,800 employees are in the United States. 16
   • Customers headquartered in the United States accounted for 65.6% of net sales. 2422
   Confidence 85 of 100Wrong if A year-end filing showing Korea with less than half of Amkor's net plant and equipment, or US-headquartered customers below half of net sales.
3. Inferred

   Amkor's margins turn on how full its factories run: with much of its cost fixed, strong sales growth lifts gross margin quickly, while slow growth and a new factory's ramp pull it down.

   Because

   • The company says a substantial portion of its factory costs is fixed, so revenue and gross margin move together. 61
   • In the second quarter of 2026 net sales rose 25.6% and gross margin rose 4.8 points to 16.8%, which the filing puts down to higher factory utilization. 565862
   • In 2025, with sales up 6.2%, gross margin fell to 14.0% from 14.8%, held back by the ramp of the Vietnam factory. 535455
   Confidence 75 of 100Wrong if A period in which Amkor's net sales rise sharply while its gross margin falls for reasons other than start-up costs at new factories.