Innovative Approach of efficient low-temperature silver sintering on an industrial series scale for simultaneous die top and bottom level interconnections of power electronic applications

Abstract

In recent years, the number of power electronic assemblies has increased significantly both in products and machines for the end user and in products and machines for industry. Above all, however, power electronics is becoming more and more important in drive technology and the generation of renewable energies. Power electronic modules, such as inverters and rectifiers or DC converters, are required to provide more and more power in the advancing field of electromobility, while the installation space is constantly being reduced. At the same time, however, these assemblies must have the longest possible and most reliable lifetime. Previous power electronic modules have a maximum junction temperature of 150 °C due to the materials used in assembly and connection technology. New types of wide band gap semiconductors, however, already offer the possibility of enabling junction temperatures of 200 °C and above. The aim of the investigations in this paper is to qualify a sintering process that is suitable for efficient series production for an all-in-one joining process in assembly and interconnection technology. By replacing the solder layer with a silver sinter paste, operation at junction temperatures significantly above 150 °C is possible. However, if the maximum junction temperature is maintained at the current level of 150 °C, higher reliability and longer lifetime of the power electronic modules are expected. In active power cycling tests, the reliability of the demonstrators produced in the series sintering process is compared with the service life of soldered reference samples.