Analytical Modeling of Through-PCB Thermal Vias and Heat-Sinks for Integrated Power Electronics

This work proposes analytical thermal models for through-PCB thermal vias and passive heat-sinks, two key components of the overall junction-to-ambient thermal resistance in modern integrated power electronics circuits based on advanced wide-band-gap semiconductor technology. The proposed models aim to support the thermal design of PCB and cooling system by the quick estimation of their thermal resistances. The models are scalable in that they fully include the geometry, material properties and boundary conditions. As a case-study, reference is made to the cooling of last generation gallium nitride HEMTs in SMD type package. Here, only the static behavior is considered. The models accuracy is evaluated by comparison with accurate FEM simulations performed exploiting the commercial software COMSOL Multiphysics aided by a MATLAB routine developed by the authors.