SK Hynix has entered normal mass production of its 12-hi HBM4 product and advanced the 16-hi version to customer qualification, providing concrete milestones for its next-generation high-bandwidth memory roadmap. At the Hot Chips 2026 conference at Stanford University on Aug. 24, Lee Jae-sik, vice president of packaging engineering at SK Hynix America, said hybrid bonding will be central to stacking 20 layers or more. The company is also developing localized hotspot cooling, higher data I/O, faster per-I/O speeds and additional TSVs in logic dies to address bandwidth, power and thermal constraints. Nvidia CEO Jensen Huang said in June that Samsung Electronics, SK Hynix and Micron had all passed HBM4 qualification testing, countering earlier reports of redesigns and certification delays. SK Hynix shares in South Korea were up 1.71% as of publication.