Power modules with embedded components

Power electronics for automotive applications has strong demands regarding reliability and cost. Especially the upcoming hybrid cars and fully electrical vehicles need compact and efficient power modules. Conventionally components like IGBTs and diodes are soldered to DCB (Direct Copper Bond) ceramics and their top contacts are connected by thick Al wires. These ceramic modules are soldered to water-cooled base plates. Embedding of power switches and controllers into compact modules using PCB (Printed Circuit Board) technologies offers the potential to further improve the thermal management by double-sided cooling and to reduce the thickness of the module. In order to replace DCB ceramics a structure of thermal laminate material between thick Cu layers has been developed and the capability for thermal conduction and electrical insulation has been evaluated. For the assembly of large power IGBTs of more than 100 mm² size new silver sintering pastes have been evaluated. They enable a low-pressure sintering at temperatures below 200°C, compatible to PCB materials. In this paper the realization of a 10 kW inverter module with embedded components will be described and results of first electrical tests will be shown.