ISC Co., Ltd. — AI supply-chain exposure

ISC makes the test sockets that hold a chip in place during final test and burn-in — the mechanical interface that presses hundreds of contacts against a device so a tester can prove it works before it ships. Its silicone-rubber and pogo-pin sockets sit at the very end of the chip line, and the company is a recognised leader in that niche, supplying sockets used to test HBM stacks, server CPUs and AI accelerators.

The structural point is that a socket is a consumable: it wears, it is specific to each package, and every unit built has to pass through one. As AI chips grow more complex and test times lengthen, socket volumes rise with them. It is a small link, which is why the model places it modestly, but it is a genuine chokepoint — no working test socket, no verified shipment. That gives specialised makers durable, recurring demand tied directly to accelerator and memory output.