ASE Group is the world's largest outsourced semiconductor assembly and test (OSAT) company, providing the packaging and testing services that convert fabricated silicon wafers into finished chips. After a wafer leaves a foundry, each die must be separated, mounted on a substrate, connected to external contacts, and tested. ASE performs this across packaging types from standard wire-bond and flip chip to advanced 2.5D and 3D configurations that integrate multiple dies on a shared substrate.

AI chips have made advanced packaging one of the most constrained steps in the semiconductor supply chain. AI accelerators like Nvidia Blackwell and AMD MI300 require 2.5D packaging that bonds high-bandwidth memory directly to the compute die using a silicon interposer. TSMC performs much of this in-house through CoWoS, but CoWoS capacity has remained fully booked as AI chip demand has grown faster than TSMC's ability to expand. ASE has absorbed overflow from this constraint, taking packaging work for AI chip designs that cannot be served within TSMC's own facilities.

Q3 2025 revenue reached approximately $5B, up ~20% YoY. ASE is developing CoWoP as an alternative 2.5D packaging solution, giving customers an option outside TSMC's CoWoS process. As AI chip architectures continue integrating more chiplets—compute dies, memory stacks, networking tiles—the value and complexity of each packaging engagement grows.