Abstract: At hypersonic speeds, the instantaneous temperature of spacecraft can reach higher than 1 600 ℃. To ensure the reliability and safety of the aircraft, it is critical to accurately measure the surface temperature of the thermal protection system in real time. In view of the technical problems of real-time temperature measurement in high temperature environments, and combining magnetron sputtering technology and ceramic sintering technology, this paper proposes a small thin film temperature sensor structure which integrates the lead wire and the sensor substrate. High temperature insulation of the ceramic insulating substrate of the sensor is tested by high temperature verification furnace. The main structural materials of the sensor are screened by various microscopic morphology characterization methods to obtain the best material combination needed for the preparation of the thin film temperature sensor. The static calibration and comprehensive performance test of the thin film temperature sensor at high temperature are conducted. The results show that the sensitivity and repeatability of the sensor are basically consistent with the standard thermocouple, with the high temperature measurement error no larger than 4‰ when the actual ambient temperature is lower than 1 500 ℃. Additionally, it can continuously and accurately measure temperature for more than 6 h at 1 200 ℃, and the upper limit of the temperature measurement is up to 1 800 ℃, verifying the feasibility and practicability of the sensor in measuring the surface temperature in high temperature environments, thereby providing scientific basis for spacecraft surface temperature measurement and thermal protection system optimization.

Key words: thin film thermocouple, temperature sensors, magnetron sputtering, ceramic sintering, static calibration, high temperature assessment