A lead frame sheet of flat no-lead lead frames having a semiconductor die on a die pad, terminals, and plastic encapsulation except on a back side of the sheet to provide an exposed thermal die pad, exposed side walls, and exposed back sides of the terminals. A solder wetable metal or metal alloy plating layer is on the back side and on the exposed the walls of the terminals. The exposed thermal pad and the back side of the terminals each include a contact region which lacks the plating layer.