TSMC and Amkor have announced a long-term partnership to expand advanced chip packaging in the United States, the two companies said.

Advanced packaging is the step that comes after a chip is manufactured: it's how individual pieces of silicon are assembled, connected, and tested before they end up inside the products people actually use. As chips get harder to shrink, how they are packaged together has become just as important to performance as how they are made.

The agreement runs for 10 years and covers advanced packaging and test services, according to The Business Journals. The deal links two large investments already taking shape in Arizona. The Business Journals reports that TSMC has poured money into the north Phoenix area, building a sprawling $165 billion semiconductor campus, while Amkor continues to grow its own advanced packaging and test campus nearby in Peoria.

The companies frame the tie-up as a way to keep more of the chip supply chain on American soil. According to Dataquest, the collaboration is expected to enable a more integrated and resilient semiconductor supply chain that benefits customers across a broad range of end markets.

For years, the most advanced packaging work has happened largely in Asia, even for chips designed by U.S. firms. By pairing TSMC's manufacturing presence with Amkor's packaging expertise in the same region, the partnership aims to close that gap.

Why it matters: chips now sit at the center of everything from smartphones to AI data centers, and building out U.S. packaging capacity reduces reliance on overseas facilities for a critical, easily overlooked stage of production.