Kumamoto’s Magnitude-7 Quake Renews Chip Risk 10 Years After 2016 Disaster

Sony, Renesas Halt Production

TSMC Continues Equipment Checks and Recalibration

Liquefaction and Ground Subsidence Hit Yatsushiro Port

Fears Rise Over Disruption to Chip-Material Shipments

A magnitude-7 earthquake struck Kumamoto Prefecture in Japan’s Kyushu region for the second time in a decade, renewing concern over the vulnerability of the area’s concentrated semiconductor and auto manufacturing belt. Damage has also been confirmed at key infrastructure including ports, raising fears that supply-chain disruptions could persist. The Japanese government warned that another major quake is possible because part of the fault has yet to rupture.

Chip Plants Shut for a Third Day

Yomiuri Shimbun and Nikkei reported on July 30 that many semiconductor- and auto-related companies in the Kumamoto area had suspended factory operations for a third straight day after the July 28 earthquake.

Sony Semiconductor Solutions, a Sony Group unit, halted operations at its image-sensor plant in Kikuyo, Kumamoto Prefecture. After the 2016 Kumamoto earthquake, it took three months for all processes to resume.

Renesas Electronics also suspended operations at its Kawashiri and Nishiki plants, which make automotive semiconductors and other products. TSMC’s first Kumamoto plant has resumed production, but the company is continuing to inspect and recalibrate manufacturing equipment after the strong shaking. It said the work will take considerable time.

Semiconductor plants produce fine circuits through hundreds of processing steps. It typically takes about three months from wafer input to shipment, and even a microscopic scratch on products in process can force them to be discarded. Even when buildings suffer no major structural damage, restoring equipment precision and verifying quality can take time.

Key infrastructure used to transport semiconductor raw materials was also damaged. Japan’s Ministry of Land, Infrastructure, Transport and Tourism said liquefaction, cracking and ground subsidence were found at Yatsushiro Port in Yatsushiro, Kumamoto Prefecture.

The Yatsushiro city government said the port is the only one in southern Kyushu authorized to handle hazardous materials such as high-pressure gas and chemical products essential for chipmaking. Nippon Express Holdings, which handles logistics operations at the port, said repairs could drag on.

Water, Land and Supply Chains Helped Kyushu Become ‘Silicon Island’

Japanese companies chose Kyushu despite earthquake risk because no region in Japan is fully insulated from natural disasters, and the area offers abundant water, large tracts of land, industrial labor, customers and supply chains.

Kumamoto has abundant groundwater formed as rainfall around Mount Aso passes through volcanic strata. That gives it an advantage in semiconductor production, which requires massive volumes of ultrapure water.

Those strengths drew Japanese electronics companies to build factories across Kyushu from the 1960s onward, helping the region earn the nickname “Silicon Island.” More recently, TSMC’s arrival has made the area a symbol of Japan’s effort to rebuild its semiconductor industry.

The auto industry followed a similar path. As Nissan Motor, Toyota Motor and Daihatsu Motor set up production bases there, parts suppliers clustered nearby, accelerating industrial concentration. Easy port access for exports and proximity to Asian markets including South Korea, China and Taiwan also bolstered Kyushu’s competitiveness.

But after another major earthquake, following the 2016 disaster, concern is growing that the industrial clustering that boosts efficiency in normal times can turn into supply-chain concentration risk during disasters. A shutdown at a single factory or port can spread quickly across multiple companies and industries.

Kumamoto Castle Damaged Again as Officials Warn of Unruptured Fault Section

Kumamoto Prefecture’s tourism industry is also set to take a hit. Kumamoto Castle, the region’s best-known landmark with a 400-year history, sustained fresh damage. The Kumamoto Castle General Office said at least 28 locations inside the castle were found damaged in the latest quake.

Kumamoto Castle is considered one of Japan’s three great castles, alongside Nagoya Castle, Osaka Castle and Himeji Castle. It was completed by Kato Kiyomasa, the Japanese warlord who invaded Korea during the Imjin War and captured Prince Imhae and Prince Sunhwa, sons of King Seonjo. The castle had already been undergoing long-term restoration after stone walls and parts of the main keep’s roof collapsed in the 2016 earthquake. It was hit again before that recovery was complete.

Japan’s Earthquake Research Committee also raised the possibility of another major quake. Chairman Kazushige Obara told a news conference that part of the fault in the Kumamoto area remains unruptured and could generate an earthquake in the future.

The committee puts the probability of a magnitude-7.3 earthquake in the Yatsushiro Sea section within the next 30 years at as high as 16%. It has classified the area in its highest-alert S category.

Tokyo

Choi Man-su, correspondent

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