A semiconductor chip package generally comprises a lead frame, a semiconductor die and a plastic package body. The lead frame includes a plurality of leads and a window pad. The window pad is connected to the lead frame by connecting bars. The inner ends of the plurality of leads defines a central area. The window pad is disposed in the central area and has an opening defined therein. The semiconductor die is disposed in the opening of the window pad and has a plurality of bonding pads formed on the active surface thereof. The inner ends of the leads are interconnected to the bonding pads on the semiconductor die through a plurality of bonding wires. The lead frame, the semiconductor die and the bonding wires are encapsulated in the plastic package body wherein the lower surface of the lead frame and the backside surface of the semiconductor die are exposed through the plastic package body.