Renesas Electronics has decided to phase out production at its Takasaki Factory in Gunma Prefecture, citing structural change across the semiconductor supply chain for 6-inch wafer lines. The chipmaker will wind down manufacturing over the next two to three years while maintaining and strengthening research and development functions at the site.

Production materials and maintenance support for the ageing equipment needed to run Takasaki’s 6-inch line are being discontinued industry-wide, Renesas said, making continued output of certain products increasingly difficult. The company will assess customer demand and build up inventory to maintain a stable supply before manufacturing ends and the factory closes.

Renesas plans to reposition the site’s R&D work, which covers analog ICs and discrete power semiconductors, toward developing chips for data centre and automotive applications, both strategic priorities for the company. The current Takasaki location and nearby sites are being considered as the primary candidates for these retained functions.

Employees affected by the closure will be offered reassignment and career support within and outside the company, Renesas said, as part of its policy to preserve jobs. The decision reflects wider pressure on legacy wafer-fabrication lines as chipmakers redirect capital toward advanced nodes serving automotive and data centre demand.

Why this matters:

• 6-inch wafer line obsolescence is a supply chain signal, not just a factory decision.As production materials and equipment support for older wafer geometries are discontinued industry-wide, any automotive customer still dependent on legacy analog ICs and discrete power semiconductors faces a shrinking supplier base—and a narrowing window to qualify replacements before the lines disappear.
• Repositioning R&D toward data centre and automotive power semiconductors confirms where Renesas sees its structural growth.The same analog and power device expertise that served legacy automotive is now directly applicable to AI infrastructure power management—a demand driver that makes the pivot commercially logical rather than merely defensive.