Stress Analysis of Thin Film Thermocouple Sensor Based on Finite Element Simulation

Abstract

As a new type of micro device, the reliability of thin film thermocouple sensor is very important in actual work. Aiming at a thin-film thermocouple sensor with NiCr as the functional layer, three main stresses of the thin-film sensor in actual work are analyzed: thermal stress, vibration stress and centrifugal stress. Various stress analyses have been verified through theoretical calculations or finite element simulations. The results show that thermal stress is the main influence stress, and the critical areas of reliability have been obtained. The prepared thin film sensor samples were tested through high temperature experiments, and the analysis results were verified. When a thermal load of 700 degrees Celsius is applied, the stress environment of the protective layer, the functional layer and the insulating layer of the structure is severe, and it is vulnerable to severe damage, and cracks are found in the insulating layer, which becomes a weak area of reliability.