Fabrication and Calibration of Cu-Ni Thin Film Thermocouples

Abstract

Thin film thermocouples (TFTCs) have vast vistas owing to their advantages, such as thin junction, small volume, fast response rate, high sensitivity and so on. In this investigation, a transient temperature sensor of TFTCs was fabricated to measure the surface transient temperature by vacuum coating technology. Silicon dioxide was selected as insulating substrate, the overall dimension of which was 8 mm long, 8 mm wide, and 0.1 mm thick. Two different metal layers were sandwiched between silicon dioxide 2 insulating substrate and silicon dioxide protective layer: cuprum and nickel films, which were 0.08 μm thick. TFTCs consist of 13 Cu-Ni junctions, which are connected in series. The whole TFTCs area is 4.6mm × 4.6 mm. The aggregate thickness of the transient temperature sensor is 0.17 μm. To protect Cu and Ni films, a silicon dioxide layer thickness of 0.01 μm was evaporated on metal layers excluding terminal points. This research carried out static and dynamic calibration to TFTCs. The Seebeck coefficient of the thin film thermocouple is 0.83843 μV/°C. The dynamic performance of TFTCs exhibited dynamic behavior corresponding to the heat flux change on the surface of thin film thermocouple.