Optimizing Power Modules by Enhancing Power Density, Ease of Implementation and Supporting Automotive Reliability Requirements

Abstract:
Increasing power density, enabling compact systems and a high vehicle range are key success factors for power semiconductor solutions within electric vehicles. At the same time, it is necessary to fulfill their lifetime requirements and ensure the respective level of reliability and safety across high production volumes. With the second generation of the Hybrid-PACKTM Drive Infineon Technology AG has developed an automotive power module meeting all these targets. Perfor-mances up to 300 kW are possible within the HybridPACKTM Drive footprint thanks to an increased operating temperature in combination with the latest generations of SiC MOSFETs and Si IGBTs. To ensure vehicle lifetime despite the resulting increased temperature stress within the modules, its power cycling robustness was improved accordingly. In this paper, the benefits of new functionalities, like the integration option for a next-generation phase current sensor, on-chip temperature sensors for IGBT products and single chip temperature diodes for SiC products, are presented. Furthermore, new materials (frame, isolation gel) and interconnection technologies and their impact on reliability are introduced. In detail we'll demonstrate: - Infineon has elaborated a solution that allows significant Power Cycling improvements with Aluminium based bond wires of more than 100 k Cycles @dT =100 K at Tvj=175deg C (PCsec) - The introduction of new materials allows operation at higher temperature up to 200deg C without sacrificing reliability - Press-fit pin are qualified in an automotive power module according to IPC-9797 for the first time - The reliable implementation of an integrated hall based current sensor together with our partner Swoboda into the power module’s frame