In this paper, a new and dedicated phase change cooling concept is discussed, following the goal to buffer periodic overload operations of electric power modules and thus keeping junction temperatures constant. A top-mounted latent heat storage material (LHSM) buffer is applied, to soak the overload heat in conjunction with thermo-electric coolers (TECs), which control the temperature and phase change process. The cooling system is going to be realized within an IGBT converter module, undergoing repeated overload situations. The concept features double-sided cooling and assembling as well as new materials and joining technologies such as transient liquid phase bonding/soldering and silver sintering. One-dimensional equivalent circuit estimations and transient electro-thermal FE simulations were used to calculate the cooling performance, extract optimization guidelines and discuss potential difficulties of the concept. Furthermore, the simulations are successively refine d and brought into agreement with various test stands and characterization methods of reduced complexity