Critical semiconductor maker Renesas Electronics Corp. said it had resumed partial test-run production at two of three plants near the quake zone. Those plants, its Naka and Takasaki factories, should reach full pre-earthquake production capacity on March 23.
The third Renesas plant that was affected, its Yonezawa factory, restarted all production processes on March 18 and expects to return to normal operational levels on March 20.
All three plants, which make chips for the automotive sector, were automatically shut down when the quake struck. Any long-term interruption at Renesas could have broadsided a global automotive industry already reeling from the worldwide semiconductor shortage.
Renesas emerged as a weak link in the 2011 earthquake, when its Naka plant was thrown offline for months.
And in February 2021, the Naka plant was hit by another earthquake and was down again for several days as Renesas raced to confirm the status of its fragile clean room operations.
Separately, Toyota supplier Denso Corp. said some of its factories in the quake zone were damaged and are still being checked out. Other facilities are slowly coming back online.
A Denso spokeswoman said the company could not say when full production would resume.
Meanwhile, Hitachi Astemo, the Honda-affiliated supplier, has suspended operations at five factories in the disaster area as teams assess damage to the facilities.
A Hitachi Astemo spokesman said some factories were damaged but the company doesn’t foresee major interruptions.
The company is monitoring its own intake of components from lower-tier suppliers and aims to begin a phased-in restart of its factories sometime next week.