Study on high temperature reliability of electrical interconnection material of SiC pressure sensor

In this paper, the effects of the composition and sintering process of the conductive silver paste on the packaging and electrical interconnection performance of the silicon carbide high temperature pressure sensor are studied in detail. At the same time, a self-built high temperature reliability test platform is used to test the electrical interconnection reliability of the conductive silver paste under high temperature environments. The results show that flake silver powder can not only effectively promote the density of the conductive silver paste, but also improve the grain boundary migration behavior of the conductive silver paste, thereby improving the electromigration resistance of the sintered silver. The prepared conductive silver paste has good compatibility with high temperature pressure sensor materials such as SiC, AlN, and Pt, and the adhesion strength reach 23.12 MPa, 26.35 MPa, and 19.22 MPa, respectively. When the silver paste does not contain flake silver, the sheet resistance of the sintered silver paste is the lowest at 650 °C, which is only 2.58 mΩ/□, and there is still room for improvement. The high temperature stability test shows acceptable performance, but in the high current test with a current density of 125 A/mm², the failure time is only 105 min. After adding 20 wt% of flake silver powder, the sheet resistance of the silver paste can be further reduced to 1.50 mΩ/□ by 41.9%, and the failure time can be extended to 158 min, with a 50.5% increase.