AI Power Pushes Thermal Limits as Materials Take Center Stage in Advanced Packaging - EE Times Asia

When a single AI accelerator crosses 1,000W, thermal management becomes a materials science problem, not an engineering one. That is the real chokepoint. Organic-silicon TIMs cap at 8-10 W/mK; next-gen heterogeneous integration demands above 20. The physics wall is here. Materials cost in advanced packaging BOM will jump from roughly 15% to over 30%, restructuring OSAT margins across ASE, Amkor, and TSMC's CoWoS ecosystem. Upstream, Ibiden and Unimicron must redesign thermal pathway topology. Downstream, NVIDIA's CoWoS-L expansion is a thermal-budget game, not a capacity game. AMD's UCIe small-die strategy dilutes heat density, but inference workloads will not cooperate. The wildcard: diamond and liquid-metal TIMs. Diamond Foundry's Cerebras deal signals a shift from passive conduction to active thermal management. Covestro and Shin-Etsu's TIM monopoly faces structural disruption by 2026. Geopolitically, indium and rare-earth thermal fillers are becoming the next export-control flashpoint. US CHIPS-subsidized packaging lines still dependent on Asian material supply chains will see subsidy efficiency erode. 12-24 month call: immersion liquid cooling migrates from HPC to enterprise AI servers. TIM migration from organic to inorganic composites is irreversible. OSATs that do not extend upstream into materials will shed another 5-8 points of gross margin by 2026.