Thesis (M.S., Chemical and Materials Science Engineering) -- University of Idaho, 2017 | Power conversion units are used any time there is an electrical energy conversion or a nominal voltage change, which makes them a crucial part of everyday modern life. The thermal management of these devices can be difficult with the push toward higher density electronics. In this work, heat sink sizing techniques are used to evaluate the required cooling needs of a multi-stage, multi-phase, high-efficiency power conversion unit. Traditional parallel plate finned heat sinks in both forced and natural convection environments are evaluated using finite element analysis, and analytical correlations, and further compared to experimental results. The feasibility of heat recovery within the realm of power electronic devices, specifically with thermoelectric generation is also presented. With the use of a thermal core heat sink design, a compact thermal solution is developed and modeled using analytical correlations and finite element simulations.