Packaging material issues in high temperature power electronics

Current developments in the automotive and aerospace industries frequently result in increasing temperatures, reliability and lifetime requirements for power electronic components, modules, and systems. In this context, a key aspect with enormous potential for improvement is the packaging. This includes the required implementation of new advanced materials for high temperature applications of up to 300 °C. This paper outlines power-electronic packaging issues, focusing on latest developments concerning substrate-, die attach- and chip contacting materials. An exemplarily discussion of substrate advancement is conducted by comparing commonly used Direct Copper Bonded (DCB) substrates with relatively new Direct Aluminum Bonded (DAB) substrates. The second main focus lies in the substitution of soft solder by more enhanced, temperature stable and lead-free technologies for attachment. Three promising new processes are silver sintering, diffusion soldering and reactive multilayer bonding. Finally, the adoption of new wire bond materials, as well as other concepts as an alternative to aluminum heavy-wire bonding, will be discussed.