Design and qualitative thermographic comparison of different power inverter packaging

The effect of mechanical packaging optimization for a low power three phase inverter is investigated and measured in this paper. Furthermore, the effect of source pin thermal modification is fully verified using qualitative thermographic measurement. It is shown that a proper assembly technique which takes the appropriate heat distribution into account leads to a significant improvement of the inverter´s thermal characteristic. Consequently, the power density of the inverter can distinctly be increased. Two electrically almost identical but mechanically different inverters, using TO-247 package Power-MOSFETs, are constructed and compared. The results of thermographic measurements reveal remarkable improvement in current capability of the inverter.