CoWoS ☆

Chip-on-Wafer-on-Substrate mounts GPU dies and HBM stacks side by side on a silicon interposer. Every NVIDIA and AMD flagship uses it, and during 2023–24 CoWoS capacity — not wafer supply — was the binding constraint on global GPU output, forcing TSMC to multiply capacity several-fold. CoWoS-L, with local silicon bridges in an organic interposer, carries Blackwell and Rubin's ever-larger assemblies.