A Flexible Film Thermocouple Temperature Sensor

This article introduces a thin-film thermocouple temperature sensor with symmetrical electrode structure. It uses PI film as a flexible substrate. Cu film and CuNi film made by MEMS manufacturing process as positive and negative electrodes. The device itself has the advantages of miniature, bendable and fast response speed. In order to reduce the resistance value of the film, an experiment was conducted to optimize the thickness of the metal film and the temperature of the sputtering substrate. The critical dimensions of Cu/CuNi film are 650 nm and 400 nm respectively. The best sputtering substrate temperature for Cu/CuNi films are 100 ℃ and 150 ℃. Testing the adhesion of thin film thermocouples using the peel-off method. The test result is 9.4 N. Finally, the film thermocouple temperature sensor is subjected to a temperature static calibration experiment. The result shows that the actual potential difference error is within ± 1 ℃. It belongs to the second class standard in the formulation of thermocouple standards in China. Through curve fitting, the corresponding relationship between temperature and potential difference is more accurate.