Fabrication and calibration of Pt/Au thin-film thermocouple based on a modified screen printing technology

Abstract

The purpose of the current study is to find a low-cost and rapid-fabrication approach for producing Thin-film thermocouples (TFTCs) with different junction thicknesses. Nowadays, the popular TFTC fabrication methods are usually based on physical vapour deposition technology. They are high time cost and poor economy. In order to improve the production efficiency, a modified screen printing technology which is combining with wet grinding technology was employed in this article. First, the uniform thickness Pt/Au TFTCs were fabricated based on the regular screen printing technology. Then, the different junction thickness TFTCs were obtained through polished by an automatic high precision lapping machine. With this step, the junction thickness of TFTC is no longer limited to the viscosity and fineness of the ink in the present method. Through the calibration experiments, the static and dynamic performance of the fabricated Pt/Au TFTCs were estimated. The results show that the Seebeck coefficient of these TFTCs have no significant degradation compared with wire-style thermocouples in the temperature from 50 °C to 620 °C. The repeatability and consistency of these TFTCs are satisfying the requirements of the wire-style thermocouples. The pulse laser heating experiments results show the response time constant of these TFTCs are less than 12.33 μΞ. Compared with other screen-printed TFTCs, the Pt/Au TFTC presented in this study has a wider temperature measurement range. This implied that this rapidly and economically fabricated TFTCs can satisfy the requirements in many transient surface temperature measurement applications.