MEMS热电堆芯片固晶工艺参数的优化

The die-bonding process is one of the key steps to ensure accurate temperature measurement by MEMS thermopile sensors. However, there remains no effective method to accurately optimize the process parameters of MEMS thermopile die-bonding. In this paper, the working principle of the thermopile sensor was introduced, and the requirements of the die-bonding process parameters-thickness and fillet height were proposed. Guided by the die-bonding process requirements, the influence of the pressure parameters on the process was initially explored, and the pressure parameters were optimized. Under optimized pressure parameters, the influence of the dispensing height and patch height on the die-bonding process was explored, and the range of choices for the two parameters was narrowed. On this basis, the finite element software package ANSYS was used to analyze the thermal stress distribution of different silver paste and chip thicknesses at the same temperature to determine the optimal die-bonding thickness and accurately optimize the dispensing height and patch height. Finally, through the experimental verification method, the test results were given for the die-bonding strength of MEMS thermopiles under these parameters. The experimental results indicate that when the pressure is 0.3 MPa, the patch height is 460 μm, and the dispensing height is 140 μm, the MEMS thermopile chip achieves average solid crystal thrust of 43.14 N. These parameters ensure the highest quality of the solid crystal, satisfy the die-bonding strength requirements, and help improve the reliability and yield of MEMS thermopile chip packages.