Of the seven semiconductor fabs completed in Japan during fiscal 2023–2024 (April 2023 to March 2025), only three had begun mass production by April 2025. New facilities from Kioxia, Renesas Electronics, Rohm Semiconductor, and Sanken Electric remain inactive, while Sony has launched production but is moving forward conservatively.
Kioxia completed its second fab at the Kitakami (K2) site in Iwate Prefecture in July 2024, according to Nikkei. The company is delaying production until market conditions for NAND flash improve. Mass production is now scheduled for fall 2025, targeting advanced 8th-generation NAND to meet rising AI-driven demand.
EE Times Japan and The Yomiuri Shimbun report that Renesas reopened its Kofu plant in Kai City, Yamanashi Prefecture, in April 2024—nine years after shutting it down. The fab was scheduled to begin production in early 2025, but the plan has been postponed due to falling demand for EV power semiconductors. A revised timeline has not been disclosed.
Rohm began converting a 400,000-square-meter site in Kunitomi, Miyazaki Prefecture, in 2023 to combine SiC wafer production with power semiconductor manufacturing. Trial production began in November 2024 as scheduled, but the company has not announced a mass production start. Weaker EV demand has led to rare losses, prompting Rohm to scale back investments and initiate layoffs.
Sanken Electric has also postponed mass production at its new facility in Ojiya, Niigata Prefecture, which was acquired to boost power semiconductor output. Production is now expected to begin after 2026, about two years later than originally planned.
Article edited by Jack Wu
