Hidden beneath AI chips, Chinese-made circuit boards raise national security concerns in U.S.

Printed circuit boards sit underneath almost every chip, a necessity in nearly every electronic. They make up a quiet but crucial piece of the booming artificial intelligence market, and represent a growing problem for the U.S., because nearly all AI circuit boards, for Nvidia and others, are made in China. Circuit boards present all sorts of opportunities for adversaries to sneak through malicious components. That vulnerability has created national security concerns so significant that the U.S. Defense Department is requiring most of its purchases to come from the dwindling number of domestic factories. "Chips, substrates, PCBs represent multiple avenues of attack for a potential malicious actor," said Mike Cadenazzi, U.S. assistant secretary of war for industrial base policy, in an interview with CNBC. Worst case scenario, he said, a compromised PCB could mean a "missile malfunctions in flight." Some 30% of the world's supply of printed circuit boards, or PCBs, used to come from the U.S. That number has dropped to just 4%, according to the Printed Circuit Board Association of America, or PCBAA. Domestic capacity can't keep up with state-sponsored manufacturers in China, where material and labor costs are also lower. PCBAA executive director David Schild said six of 10 PCBs are now made in mainland China, which he described as a "risky dependency." Former U.S. …