Heat analysis on insulated metal substrates [power electronics]

Applications of insulated metal substrates (IMS) for high-density and high-power mounting are rapidly extending with the miniaturization of electronic devices. The recent progress in insulation reliability and thermal conductivity of IMS has been making applications as substitutes for alumina DBC substrates possible. However, customers and/or potential customers are not satisfied with performance of conventional IMS for high-powered applications and an improved IMS equipping higher thermal conductive insulating layers is desired to widen the applications for high-powered devices. The influence of materials of which the IMS consists, i.e. base metals, insulating layers and copper conductors, were analyzed theoretically using FEM, and experimental data measured with a temperature distribution measuring instrument "Thermoviewer" were compared with the analytical data. The influence of the materials have been clarified through the analysis. In addition, an alumina DBC substrate and "GPS", which is a special IMS developed newly for large-current and high-powered devices, were also investigated comparatively by simulation and experiments.