Who makes air-cooled heatsinks & vapor chambers for AI data centers

Heatsinks and vapor chambers sit directly on chips that aren't covered by a liquid cold plate (layer 5.01) — memory, networking silicon, VRMs, and, in air-cooled server configurations, the CPU or GPU itself — spreading heat across a larger surface area for fans (4.13) to carry away. As rack-scale AI systems move the highest-power chips to liquid cooling, this part's role narrows to the components liquid cooling doesn't reach and to the segment of the market still running air-cooled GPU servers rather than rack-scale liquid systems. That narrowing role doesn't mean the part disappears — it means the design problem shifts toward smaller, more thermally demanding heatsinks squeezed into a chassis that also has to route liquid-cooling plumbing, rather than large heatsinks free to use as much airflow and space as needed. For investors, this tier's growth is more tied to the air-cooled and hybrid segment of the server market than to the highest-end liquid-cooled racks, so its trajectory diverges somewhat from the rest of this layer as liquid cooling adoption increases.