Micron breaks ground on ¥1.5T Hiroshima HBM fab; first shipments targeted for summer 2028

Micron Technology broke ground on July 4, 2026, on a ¥1.5 trillion (~$9.3–$9.6 billion) expansion of its Hiroshima, Japan facility to produce high-bandwidth memory (HBM) chips. Construction kicks off in May 2026, with initial HBM shipments projected for summer 2028. The Japanese government, through the Ministry of Economy, Trade and Industry (METI), is providing subsidies in the range of ¥500–536 billion (~$3.2–$3.5 billion), making Japan's total public support for Micron's Hiroshima operations roughly ¥774.5 billion (~$5B). The new fab will use advanced extreme ultraviolet (EUV) lithography; Micron deployed its first EUV system at Hiroshima in May 2026.

This is Micron's first major capacity expansion since 2019 and signals the company's determination to challenge SK Hynix's 55%+ global HBM market share. Micron's HBM capacity was fully allocated through 2025 and on track for sell-out in 2026; the Hiroshima project addresses structural demand from hyperscalers and AI chip vendors. Competing chipmakers SK Hynix and Samsung are also ramping HBM capacity at pace: SK Hynix is targeting 20–30% HBM capacity growth from its M15X fab starting 2026 and the 600 trillion won Yongin mega-cluster through decade's end; Samsung is ramping 1c-process DRAM to 200k wafers/month by 2026 toward HBM4 mass production.

For AI infrastructure architects tracking HBM supply: Micron's 2028 timeline puts volume shipments 1–2 years behind Korean competitors, extending SK Hynix's near-term dominance. However, the Hiroshima project diversifies supply away from Taiwan and secures US policy support via Japan-US alliance terms—a geopolitical hedge as tariff and export-control uncertainty rises. Watch for design-win announcements with Nvidia and AMD, capex timing on packaging tech (CoWoS/EMIB), and how subsidies track against project milestones.