A housing cover to cause electrical components to engage with at least one component pad of a heat sink, the cover including a projection integrally formed from the housing cover and positioned on the cover for biasing the electrical component against the component pad, and a mechanism that permits a vertical displacement of the projection relative to the vertical displacement of the housing cover. In one example, a slot extends around at least part of the projection so as to substantially decouple a vertical displacement of the projection from a vertical displacement of the housing cover.