Power module integrated cooling design using CFD simulation

Thermal grease used in classical power module water-cooling takes 40 percent of the water-cooled heat sink thermal resistance. This part which belong to conduction phenomena can be suppressed using a direct cooling method. In this paper, the basic conduction term provided by the component packaging is firstly determined, using several methods. Then mini water-cooled channels are directly machined in a standard power module baseplate, taking into account mechanical and technological constraints. In the same way a CFD tool, FLOTHERM from Flomerics is used in order to improve equipment performances such as a low junction to ambient thermal resistance, that approaches the power module's own thermal resistance, a low pressure drop, a high dissipated power and a low gradient in coolant temperature. The equipment thermal and electrical behaviors are finally compared to a typical equipment including a power module and a cooling device mounted with thermal grease utilisation.