Mie Fujitsu Semiconductor Limited

Mie Fujitsu Semiconductor Limited (MIFS) is a Japanese semiconductor manufacturing company that originated as a spin-off of Fujitsu's semiconductor fabrication operations at its Mie plant in Mie Prefecture, Japan. It operates as a foundry-style chipmaker, producing logic and other semiconductor devices on a contract basis for customers rather than only for its parent group. The company emerged from Fujitsu Semiconductor's restructuring of its manufacturing footprint, in which the Mie fab was carved out into a dedicated foundry entity. This allowed Fujitsu to keep advanced wafer capacity available while shifting toward a fab-lite model and opening the plant to external customers. MIFS later became part of Taiwan-based United Microelectronics Corporation (UMC), which acquired a majority stake in the company and integrated it into its global foundry network. Through this ownership, the Mie facility has been positioned as UMC's manufacturing base in Japan, serving Japanese and international chip customers. As a brand, MIFS is a business-to-business semiconductor foundry name rather than a consumer-facing label. Its identity is tied to Japanese wafer manufacturing capability, the Fujitsu semiconductor heritage, and its later role within UMC's foundry operations. Detailed public information on its founding date, executives, and product mix is limited, and the entry should be treated as a concise identity record.

Mie Fujitsu Semiconductor Limited (MIFS) traces its origin to Fujitsu's semiconductor manufacturing operations at its Mie plant in Mie Prefecture, Japan. As part of Fujitsu Semiconductor's broader restructuring toward a fab-lite strategy, the Mie fabrication facility was separated into a dedicated foundry company, allowing the plant to serve external customers in addition to Fujitsu's own needs. The spin-off reflected a common pattern in the Japanese semiconductor industry, where integrated device manufacturers carved out wafer fabs into independent or semi-independent foundry entities to improve capacity utilization and attract third-party business. MIFS subsequently drew the interest of Taiwan's United Microelectronics Corporation (UMC), one of the world's major pure-play foundries. UMC acquired a majority stake in MIFS, bringing the Mie facility into its global manufacturing network and positioning it as a Japanese production base for UMC's foundry customers. Publicly documented details on MIFS's exact founding date, leadership, and product portfolio remain sparse, and the brand is best understood as a B2B foundry identity rooted in Fujitsu's semiconductor heritage and later absorbed into UMC's operations.

• Fujitsu's Mie semiconductor fabrication facility is separated into a dedicated foundry company, Mie Fujitsu Semiconductor Limited (MIFS).

• United Microelectronics Corporation (UMC) acquires a majority stake in MIFS, integrating the Mie fab into its global foundry network.

Business-to-business semiconductor foundry tied to Japanese wafer manufacturing and later UMC's global foundry network.

• Contract wafer fabrication (foundry services)

• Logic semiconductor devices

• 2019-09-25

  UMC announced acquisition of MIFS[1]联电宣布收购三重富士通半导体finance.sina.com.cn

  Reported: 2019-09-26

  United Microelectronics Corporation announced that it had received approval to purchase the remaining 84.1% equity stake in Mie Fujitsu Semiconductor, making it a wholly owned subsidiary. Completion was scheduled for October 1, 2019.

• 2019-09-25

  UMC receives final approval to acquire MIFS[2]联电获准收购三重富士通半导体finance.sina.com.cn

  Reported: 2019-09-25

  UMC announced that it had received final approval from the relevant government agencies to acquire all shares of Mie Fujitsu Semiconductor (MIFS), with completion planned for October 1, 2019.

1. 1联电宣布收购三重富士通半导体finance.sina.com.cn
2. 2联电获准收购三重富士通半导体finance.sina.com.cn