Advanced packaging capacity is the current supply chain constraint for AI accelerators and high-performance chips. [[CoWoS and 2.5D Packaging]] from TSMC is tight. [[HBM and Package Integration]] requires specialized assembly lines that take 18-24 months to build and qualify. You can have wafers but can't ship chips without packaging capacity. This bottleneck creates the investment opportunity. [[OSATs - Outsourced Semiconductor Assembly and Test]] like [[Amkor - AMKR]] and [[ASE Technology - ASX]] are racing to add capacity, but it takes time and capital. Why the bottleneck persists: - Advanced packaging is harder to scale than traditional assembly - Yield learning curves are steep ([[Wright’s Law]] applies but slowly) - Equipment lead times are long ([[Advanced Packaging Equipment]] has its own constraints) - Customer qualification adds 6-12 months to ramp timelines The investment thesis: if AI demand stays structural, packaging capacity will remain tight for years. That supports utilization, pricing, and returns on incremental capex. The risk: if everyone builds at once, overcapacity hits and margins collapse. Watch for divergence between orders and actual end demand. Links: [[Advanced Packaging MOC]], [[Why Advanced Packaging Matters Now]], [[The infrastructure layer and AI capex]] --- #semiconductors #investing