PTC linear positive temperature coefficient thermistor is made of PTC material and physical process. It has excellent stability and complex linearity. The characteristic curve remains unchanged after millions of repetitions. The resistance value increases with the temperature, changes linearly, and has good linearity. Compared with the thermistor synthesized by PTC polymer ceramics, it has good linearity and does not require linear compensation measures to simplify the circuit design. It also has good resistance consistency, strong interchangeability, and standardized appearance and specifications. The temperature sensing speed is fast, 1-2 seconds in air medium, and has high sensitivity. It is small in size, sturdy in structure, and standardized in appearance, suitable for automated installation of printed circuit boards.