An apparatus includes a base plate including a plurality of depressions, and a power electronics printed circuit board including a plurality traces and a plurality of high voltage components. The plurality of high voltage components is located at a plurality of locations corresponding to the plurality of depressions in the base plate. A plurality of fasteners secures the printed circuit board to the base plate with the plurality of high voltage components received at the corresponding plurality of depressions. A thermally conductive and electrically isolating interface between the base plate and the printed circuit board is made of a gap filler material conforming to the base plate and to the plurality of depressions in the base plate, and conforming to the printed circuit board and to the plurality of high voltage components.