The research and development of Soldering materials applied in IGBT modules packaging

Abstract

Power modules have attracted much attention in the market, especially for high-voltage applications like switch mode power, automotive powertrain. As the requirement of high reliability, high-temperature operation improves, the packaging materials should develop to meet the applications with high properties. In this paper, the soldering materials such as Sn based lead free solder, SnPb solder, Ag-sinter are demonstrated. Soldering materials reliability is described on reliability testing especially for power cycling, temperature cycling testing, thermal shock testing. The concept is based on different applications and soldering process on Si power modules and SiC power modules. Important materials properties of thermal conductivity, CTE (coefficient of thermal expansion), elastic modulus, melting point are discussed. By comparison, Ag sintering process has a good application in high power modulus especially for SiC. SnAg solder also has the potential application in SiC modulus by IMC diffusion soldering technology.