Silicon diode thermometers have become established as accurate and reproducible thermometers for the temperature range 1–400 K. However the diodes need to be carefully selected for reliable performance; they are consequently expensive, and they also have a relatively large thermal mass. This paper describes the development of fast response (∼1 μs at 4 K), low cost, light weight (5 mg) miniature silicon diode thermometers which may be directly mounted using soft solder.