In the European funded project E3Car (ENIAC) the available power module technologies for Electric Vehicles (EV) are evaluated and tested. Up to now there are some automotive qualified power modules mostly for Hybrid electric vehicle applications on the market with rated blocking voltage up to 600V. But there are almost no 1200V automotive power modules available. This paper describes the optimization of an industrial power module by using the Finite-Elements-Method (FEM) for an improved thermal management. Starting with existing industrial power modules in this paper the baseplate design was investigated in general with simulations and thermal measurements. Then the baseplate thickness was varied in simulation in order to get a thermal optimum due to e.g. heatspreading. Then power modules with optimized baseplate design were realized and thermally investigated. Finally power cycling tests have shown that the lifetime compared to an original industrial power module was almost doubled.