Characterization and Optimization of Sn-Cu TLPS Interconnects for High Temperature Power Electronics through In-Situ-X-Ray Investigations

The production of reliable power modules capable of achieving higher power densities and higher junction temperatures is limited by the present assembly and packaging methods, mostly in the areas of the die-attach and the top level interconnections. The resultant bondline consists of intermetallic compounds with higher melting point than the used interlayer material, thus making this technique applicable to high temperature applications. This work gives an overview and compares the methodologies used to realize interconnections with respect to materials, processes and customization prospects. This work investigates the diffusion soldering process with In-situ X-Ray-analysis and provides a deeper understanding of the process conditions and the materials used. The growth of intermetallic phases (IMPs) was analyzed as well. Based on the investigations and production results, a combination of vacuum and over-pressure profile is introduced for a reliable TLPS interconnection with acceptable void percentages.