Amkor Triples Its Arizona Packaging Bet to $12 Billion

Amkor Technology said Sept. 8 it would build a second phase at its Peoria, Arizona chip-packaging campus, raising the project's total planned investment to approximately $12 billion, according to Amkor's own announcement. Phase 2 adds 60,000 square meters of cleanroom space, bringing the full campus to roughly 93,000 square meters once both phases are built.

Kevin Engel, Amkor's president and chief executive, said in the announcement that "customers need a trusted partner that can deliver at scale with the quality, technology leadership and operational discipline" the expansion is meant to provide. Amkor said the additional capacity responds to customer commitments that had already outgrown the 33,000 square meters it planned for Phase 1.

From $2 billion to $12 billion in three years

The figure has moved every time Amkor has spoken about this site. Apple's Jeff Williams, then the company's chief operating officer, said in a Dec. 5, 2023 announcement that "Apple silicon will soon be produced and packaged in Arizona," according to Chamber Business News, when the project was pitched at roughly $2 billion and 2,000 jobs. By the Oct. 8, 2025 start of construction, Manufacturing Dive reported the figure had more than tripled to $7 billion and 3,000 jobs, with Nvidia CEO Jensen Huang praising an "end-to-end silicon supply chain in America." Eleven months later, the number is $12 billion and more than 3,500 jobs.

Date	Investment total	Jobs promised
Nov./Dec. 2023 announcement	$2 billion	~2,000
Oct. 8, 2025 construction start	$7 billion	~3,000
Sept. 8, 2026 Phase 2	$12 billion	3,500+

What $407 million in CHIPS Act money actually covers

The U.S. Commerce Department awarded Amkor up to $407 million in direct CHIPS Act funding in December 2024, per Manufacturing Dive's reporting, a figure that has not changed since. Measured against the original $2 billion plan, that subsidy covered 20.4 percent of the project. Against the $7 billion construction-start figure, it fell to 5.8 percent. Against $12 billion today, the same $407 million covers 3.4 percent. The federal government's dollar commitment is fixed; Amkor's own share of the bill has grown six times over while Washington's has not grown at all.

1. Share of $2 billion (2023)20.4 %
2. Share of $7 billion (2025)5.8 %
3. Share of $12 billion (2026)3.4 %

Source: U.S. Commerce Department CHIPS award (Dec. 2024) against Amkor's 2023, 2025 and 2026 investment announcements

Who is actually paying for the capacity

Apple is the plant's first and largest customer, packaging Apple silicon chips that TSMC fabricates at its nearby Phoenix wafer fabs before Amkor finishes them. Nvidia is also named as a customer of the site, tying its own supply chain to the same Arizona campus rather than to Amkor's much larger existing operations in Asia. Amkor calls the facility its first high-volume advanced-packaging site in the United States. Its existing production, per Amkor's own overview page, otherwise runs through Asia and Europe, in Korea, Taiwan, Japan, China, Malaysia, the Philippines, Vietnam, France, Germany and Portugal.

Why the chip that gets fabricated isn't the chip that ships

A finished processor is not just the silicon wafer TSMC etches. After fabrication, a die has to be cut, bonded to a substrate, wired, tested and sealed into a package before it can go into a phone or a server, and that packaging step is what Amkor, Peoria and this $12 billion figure are actually about. For nearly the entire history of Apple silicon, that step happened outside the United States even when the wafer itself was made in Arizona, because no domestic OSAT could run it at the volume Apple needed. The Peoria campus is the first attempt to close that specific gap, not the wafer-fabrication gap TSMC's own Arizona expansion already addresses.

The gap Manufacturing Dive flagged

Manufacturing Dive's own reporting on that construction start raised a caveat Amkor's press materials do not address: TSMC had to import workers from Taiwan to staff its own nearby Arizona fab, and the outlet questioned whether Amkor's promised jobs will be as easy to fill locally as the announcements assume. Amkor has not said what fraction of its projected 3,500 positions require packaging-specific experience that does not yet exist in Arizona's labor market, or how that compares to the roughly 300,000-square-meter capacity Oracle and other cloud operators are racing to fill with GPUs elsewhere in the same national buildout.

What would change this read is a fourth investment revision before Phase 2 breaks ground in late 2027. Two revisions in three years is a pattern; a third, before a single new building is poured, would say the number was never really $12 billion so much as it was whatever the last customer commitment required at the time Amkor felt the need to announce it.

The production calendar, at least, has not moved as much as the price tag. Phase 1 is still due to start production in early 2028, the same window Amkor gave when construction started in 2025. Phase 2 construction begins late 2027 and is due to finish by the end of 2029, a full six years after Jeff Williams first said Apple silicon would be packaged in Arizona. Whether the jobs Amkor keeps promising arrive on that same schedule, in a state where the last major chip employer had to fly in workers from Taiwan, is the harder number to check, and Amkor's Sept. 8 announcement did not revisit it.