Chip embedding - The key for efficient power electronics solutions

In most of these packages the power semiconductors are connected by bond wires, resulting in large resistances and parasitic inductances. Power chip packages have to carry semiconductors with increasing current densities. Conventional wire bonds are limiting their performance. Today's power modules are based on DCB (Direct Copper bonded) ceramic substrates. IGBT switches are mounted onto the ceramic and their top side contacts are connected by thick Al wires. This allows one wiring layer only and makes an integration of driver chips very difficult. Additionally bond wires result in a high stray inductance which limits the switching frequency. Especially the use of ultra-fast switching wide-bandgap semiconductors, like SiC and GaN, is very difficult. The embedding of chips offers a solution for many of the problems in power chip packages and power modules. While chip embedding was an academic exercise a decade ago, it is now an industrial solution. This paper will show today's available power packages and power modules realized in industrial production as well as in European research projects. The presentation try to show what concrete form such systems may take in the industrial reality, what requirements these package types will be subjected to and where the development trends may lead in the future. This presentation addresses the impact of the IC´s, materials, processes and end product requirements on packaging, interconnect technology, and assembly.