In October 1937, the Toho Industrial Research Laboratory was established, and started a prototype study of selenium rectifiers.
Tetsuji Kotani, who was chief of the semiconductor laboratory of the Toho Industrial Research Laboratory, took over the engineers and facilities of the laboratory when it was dissolved at the end of World War II, and established Toho Sanken Electric Co., Ltd. in 1946.
In June 1962, the company adopted its current name, Sanken Electric Co., Ltd.
Company History
| 1946 | - Established Toho Sanken Electric Co., Ltd. at Shikimachi (present Shikishi), Saitamaken |
|---|---|
| 1952 | - Transferred the Headquarters and plant to Owadamachi (present Niizashi), Saitamaken |
| 1954 | - Opened Tokyo Office in Toshimaku, Tokyo |
| 1961 | - Listed in the Second Section of the Tokyo Stock Exchange |
| 1962 | - Changed its company name to Sanken Electric Co., Ltd. |
| 1963 | - Opened its Osaka Branch in Osakashi, Osaka - Completed Kawagoe Plant in Kawagoeshi, Saitamaken |
| 1968 | - Established SankenAirpax Co., Ltd., a joint venture company with Airpax Corporation of the U.S.A. |
| 1969 | - Listed in the Second Section of the Osaka Stock Exchange |
| 1970 | - Established Kashima Sanken Co., Ltd. - Completed Niiza Plant in Niizashi, Saitamaken - Listed in the First Sections of the Tokyo and Osaka Stock Exchanges |
| 1973 | - Opened Kyusyu Sales Office in Fukuokashi, Fukuokaken - Established Korea Sanken Co., Ltd. in Korea |
| 1974 | - Established Sanken Densetsu Co., Ltd. |
| 1977 | - Opened Hiroshima Sales Office in Hiroshimashi, Hiroshimaken |
| 1978 | - Established Ishikawa Sanken Co., Ltd. by merging five affiliates in Ishikawaken |
| 1979 | - Opened Sendai Sales Office in Sendaishi, Miyagiken |
| 1981 | - Established Yamagata Sanken Co., Ltd. |
| 1982 | - Established Sanken Kosan Co., Ltd. |
| 1984 | - Issued Swiss francs convertible bonds (50 million Swiss francs) |
| 1985 | - Issued Swiss francs notes with warrants (50 million Swiss francs) |
| 1986 | - Opened Nagoya Sales Office in Nagoyashi, Aichiken - Issued Swiss francs notes with warrants (80 million Swiss francs) |
| 1988 | - Issued US dollars bonds with warrants (US$100 million) - Established Fukushima Sanken Co., Ltd. - Opend Kanazawa Sales Office in Kanagawashi, Ishikawaken - Established Sanken Electric Hong Kong Co., Ltd. in Hong Kong |
| 1989 | - Issued US dollars bonds with warrants (US$150 million) - Opened Sapporo Sales Office in Sapporoshi, Hokkaido - Established Gooding Sanken Limited in the UK (present Sanken Power Systems (UK) Limited) |
| 1990 | - Established Sanken Electric Singapore Pte. Ltd. in Singapore - Established Allegro MicroSystems, Inc. in the U.S.A. |
| 1991 | - Issued Swiss francs notes with warrants (100 million Swiss francs) |
| 1992 | - Invested in Shimoda Electric Co., Ltd. (present Sanken Transformer Co., Ltd.), and made it an affiliate company |
| 1994 | - Opened Seoul Engineering Center in the Seoul Sales Office (present) |
| 1995 | - Issued Swiss franc notes with warrants (130 million Swiss francs) - Issued the first unsecured convertible bonds (10 billion yen) |
| 1997 | - Established Sanken TechnoResearch Co., Ltd. - Invested in Sanken L.D. Co., Ltd. and made it an affiliate company - Established P.T. Sanken Indonesia in Indonesia |
| 1998 | - Opened Takamatsu Sales Office in Takamatsushi, Kagawaken - Issued the first unsecured bonds (10 billion yen |
| 1999 | - Established Sanken Logistics Co., Ltd. - Issued the second unsecured bonds (10 billion yen) |
| 2000 | - Established Sanken Electric Korea Co., Ltd.in Korea |
| 2001 | - Established Taiwan Sanken Electric Co., Ltd.in Taiwan |
| 2003 | - Corporate Officer system introduced - Sanken Electric (Shanghai) Co., Ltd. Established in Shanghais - Investment in Sanken L.D. Electric (Jiangyin) Co., Ltd. To make it an affiliate company |
| 2005 | - Sanken Business Service Co., Ltd. (formerly Sanken Kosan, Co., Ltd.) and two other affiliates merged into a single entity - Polar Semiconductor, Inc. established in U.S.A. - Sanken Optoproducts Co., Ltd. established |
| 2007 | - Sanken Logistics Co., Ltd. established after Sanken Business Service Co., Ltd. separated its logistics business. |
| 2009 | - henzhen Office of Sanken Electric (Shanghai) Co., Ltd. opened in Shenzhen, China |
| 2010 | - Investment in Dalian Sanken Electric Co., Ltd. to make it an affiliate company - Investment in Sanken Electric (Malaysia) Sdn. Bhd. to make it an affiliate company |
| 2013 | - Established Sanken North America, Inc. (controlling company in North America region). |
| 2020 | - Allegro MicroSystems, Inc Listed on NASDAQ Global Select Market |
| 2022 | - Listed on Tokyo Stock Exchange Prime Market |
| 2023 | - Established Niigata Sanken Co., Ltd.in Japan |