A housing that can be used for a power module in a power system is disclosed. The housing includes features to improve the insulating properties and to reduce or eliminate a mechanical stress on a housing that could crack or break a substrate contained within the housing. The insulating properties are improved by protrusions that surround apertures for press-fit pins. Each protrusion can increase a creepage for the housing by extending the surface of the housing along a press-fit pin. The mechanical stress is reduced by a mounting flange that includes a wedge surface and a flexible structure that react to a force applied when the mounting flange is fastened to a surface by a fastener.