TDK Corp

TDK Corporation (TDK株式会社, TDK Kabushiki-gaisha), commonly known as TDK, is a Japanese multinational electronics company headquartered in Tokyo. Founded in 1935 to commercialize ferrite, a key magnetic material, the company is publicly traded on the Tokyo Stock Exchange (TYO: 6762). For its fiscal year ending in March 2025, TDK reported revenues of approximately ¥2.2 trillion and employs over 100,000 people globally across more than 250 sites.

TDK is an operating company that manufactures a broad portfolio of electronic components. While historically known for magnetic recording media like cassette tapes, TDK sold that business in 2007 to focus on its core operations. Today, its products are organized into several segments: passive components (such as ceramic capacitors, inductors, and protection devices), sensor application products (including temperature, pressure, magnetic, and MEMS sensors), magnetic application products (HDD heads and magnets), and energy application products (lithium-ion batteries and power supplies). These components are critical for the automotive, industrial, consumer electronics, and information and communication technology markets.

Based on tracked U.S. patent litigation, TDK’s posture is that of an operating company defending against patent assertions. It has been named as a defendant in one tracked case and has not appeared as a plaintiff. That case, Mems Innovations LLC v. TDK Corp et al., was filed in the Northern District of California in April 2026. The plaintiff, Mems Innovations LLC, is a non-practicing entity that asserts patents related to piezoelectric microspeakers originally developed by the Electronics and Telecommunications Research Institute (ETRI), a Korean research company. The litigation targets TDK's ultrasonic sensor products that incorporate microelectromechanical systems (MEMS) technology.