The Substrate Duopoly — Why the H100 Shortage Was Not a Silicon Problem

Forgotten Monopolies #3 · Playlist:    • Forgotten Monopolies   When NVIDIA's H100 ramp slipped through 2024, the bottleneck was not silicon. TSMC had the wafers ready. It was not ASML. The bottleneck was a paper-thin glass-resin sheet a few centimeters across, made by a Japanese chemistry company that started life selling food seasoning. Two companies — Ibiden of Japan and AT&S of Austria — produce the high-end ABF substrates that every CoWoS-L AI accelerator depends on. Combined market share at the most advanced layer counts: ~50%. After them, the next three substrate makers are Taiwanese. This is episode 3 of Forgotten Monopolies — the companies that almost nobody outside the supply chain talks about, but that decide what the industry can actually build. Chapters: 00:00 Hook — the H100 was throttled by paper, not silicon 00:50 Two companies, every AI accelerator 02:32 Ibiden: 80 years, Intel anchor, NVIDIA pivot 04:17 AT&S: the Austrian #2 nobody saw coming 06:05 ABF — the food company that invented the only material that works 07:53 CoWoS-L — why AI substrates throttle the build-out 09:42 Verdict — two layers, three risks 11:54 Next episode tease Topics covered: • Ibiden Co., Ltd. — Gifu, Japan • AT&S AG — Leoben, Austria · Kulim, Malaysia • Ajinomoto Build-up Film (ABF) and the MSG connection • CoWoS-L silicon bridge interposer and substrate yield • Substrate supply chain — CCL, ABF, laser drilling, plating • Asian alternatives: Unimicron, Nan Ya PCB, SEMCO • Intel glass-substrate transition Subscribe for the actual semiconductor industry view of the AI race. #Semiconductor #ABFSubstrate #Ibiden #ATS #CoWoS #AIChips #VLSI #ChipSupplyChain