Aktivlöten von Kupfer mit Aluminiumnitrid- und Siliziumnitridkeramik

Copper-AlN- and copper-Si3N4-composites are used as substrates for semiconductor modules in power electronics. Silver-based active brazing alloys are used for the fabrication of composites from copper foils and nitride ceramics. In this study the mechanisms during AMB (active metal brazing) of aluminium nitride and silicon nitride in combination with copper foils were investigated. Therefore the melting process of the braze filler metal, the chemical interactions between the braze filler metal and the raw materials and the influence of the processing parameters were studied in detail using thermo analytic and microscopic methods. Additionally, the fabrication process was tested under close to production conditions and application like samples were fabricated. The combination of lab experiments with low volume productions in industrial relevant processing equipment ensures the transferability of the developed processing models from lab into production. An increase of the AMB process reliability and an associated quality improvement as well as a significant reduction of the rejection rate during fabrication was achieved by optimisation of the active brazing alloys and the processing conditions during the active metal brazing