Founded in 1935, TDK has its origin in magnetic materials, being the first company to commercialize ferrite in the world, and it used to be known as one of the major cassette-tape manufacturers. TDK is now the only external supplier for magnetic recording heads for hard disk drives, and the company intends to expand its magnetic sensor business for handsets and automobiles by leveraging its expertise. It is also one of the global top suppliers of passive components for autos and polymer rechargeable batteries for smartphones. The company acquired InvenSense in 2017, making it one of the largest MEMS sensor companies in the world.