TDK

Set up in 1935 in Tokyo by Kenzo Saito to commercialise ferrite — a magnetic ceramic invented at the Tokyo Institute of Technology a few years earlier. The name is short for Tokyo Denki Kagaku (Tokyo Electric Chemical). To consumers TDK meant audio cassettes through the 1970s and 80s, but its core has always been components: MLCCs, inductors and sensors.

Through its subsidiary ATL it now supplies the lithium-polymer batteries in devices like the iPhone — a quiet journey from tape deck to the inside of a handset.