A method of forming a semiconductor device includes providing a semiconductor package comprising an electrically insulating mold compound body, a semiconductor die that is encapsulated by the mold compound body, a plurality of electrically conductive leads that each protrude out of the mold compound body, and a metal heat slug, the metal heat slug comprising a rear surface that is exposed from the mold compound body, coating outer portions of the leads that are exposed from the mold compound body with a metal coating, and after completing the coating of the outer portions of the leads, providing a planar metallic heat sink interface surface on the semiconductor device which is exposed from the mold compound body, and substantially devoid of the metal coating.