TSMC's Arizona Fab 21 has begun mass production of NVIDIA Blackwell wafers using the custom 4NP process, but these wafers must be shipped to Taiwan for CoWoS-L advanced packaging. This highlights a critical gap in the US semiconductor supply chain: while advanced logic fabrication is now possible domestically, the US still lacks high-volume advanced packaging and HBM memory capabilities, creating ongoing reliance on Taiwanese facilities and delaying full supply chain independence until at least 2028-2029. The 4NP process is a customized 4nm-class node for NVIDIA, and CoWoS-L combines chip-on-wafer-on-substrate with an RDL interposer and local silicon interconnect. Amkor, TSMC, and SK Hynix are building packaging and HBM capacity in the US, but these facilities are not yet operational.
Background
Advanced packaging, such as TSMC's CoWoS-L, is essential for high-performance AI chips like NVIDIA Blackwell, as it integrates multiple dies and memory stacks into a single package. US semiconductor policy has focused on expanding domestic fabrication, but packaging and memory supply chains remain concentrated in Asia, particularly Taiwan and South Korea.