Hangzhou Changchuan Technology — AI supply-chain exposure

Changchuan makes back-end semiconductor test equipment — the testers, handlers and sorters that check whether a finished chip actually works before it ships. This is the last gate in manufacturing: every die is exercised and sorted, and demanding parts are burned in to weed out early failures. Changchuan serves China's OSAT assembly-and-test houses and integrated device makers as a domestic alternative to the Advantest- and Teradyne-class tools that dominate the high end.

Its hook is import substitution at the lower and middle tiers. As China builds out domestic capacity under export limits, test-and-burn-in capacity becomes a bottleneck that has to be filled locally, and Changchuan is one of the few home suppliers able to do it. It competes below the frontier tools rather than against them, so its pricing power tracks the pace of Chinese localization more than the sophistication of any given chip. The model places it as a supplier to test capacity — a link that caps how many chips reach customers if it tightens.