GlobalFoundries has secured a $2 billion order from TSMC and will establish the first CoWoS interposer manufacturing capacity in the United States, according to a report from BigGo Finance. The deal marks an unusual instance of TSMC placing advanced packaging work with a direct foundry competitor — and it puts a critical component of AI-accelerator production on US soil for the first time.

CoWoS (Chip-on-Wafer-on-Substrate) is TSMC's 2.5D advanced packaging platform that stacks high-bandwidth memory (HBM) and logic dies on silicon interposers. Interposers are the passive silicon bridges that carry thousands of connections between a GPU or AI accelerator and its HBM stacks. They are the choke point of the entire AI supply chain: demand for CoWoS capacity has outstripped supply, and TSMC has been racing to expand output across Taiwan for years.

Why would TSMC order from GlobalFoundries?

Three pressures explain the move.

• Capacity scarcity: TSMC cannot build CoWoS capacity fast enough to satisfy AI chip customers, making outsourced interposer supply a pragmatic stopgap.
• Geography: US-based AI chip designers face pressure — from customers and from Washington — to secure more of their supply chain domestically. A US interposer source changes the commercial calculus for onshoring arguments.
• Geopolitical risk: Taiwan-concentrated advanced packaging is a single point of failure. Distributing even the interposer layer reduces exposure.

Interposers, unlike the leading-edge logic dies they connect, do not require the most advanced process nodes. That makes GlobalFoundries a credible supplier: its US fabs already run mature and specialty processes suited to interposer fabrication, and it has prior experience in silicon photonics and wafer-level packaging technologies.

What does this change for the market?

For GlobalFoundries, the $2 billion order represents one of its largest publicly reported customer commitments and validates its push up the value chain beyond its traditional specialty and mature-node business. The company exited the leading-edge race years ago, abandoning 7nm development in 2018; advanced packaging gives it a route into AI-driven demand without competing at the bleeding edge.

For TSMC, the arrangement is pragmatic rather than strategic retreat. Outsourcing interposers to GlobalFoundries frees internal CoWoS lines for the most demanding integration work while adding incremental capacity it could not otherwise capture quickly.

The BigGo Finance report did not specify production volumes, timing of the capacity ramp, or which GlobalFoundries site will host the interposer lines. Details on process qualification and customer qualifications also remain unconfirmed.

If the reported capacity ramps on schedule, the deal could establish a template for further cross-foundry packaging cooperation in the US — and intensify competition among states and fabs to host the next wave of advanced packaging investment.