Abstract: A semiconductor package having heat sink at the outer surface is constructed on a lead frame. The package comprises a chip, a die pad, a plurality of leads, a plurality of bonding wires, and a molding compound. The die pad has a first surface and a second surface, and the chip has its active surface bonded to the first surface of the die pad. The area of the die pad is smaller than the area of the chip in order to expose the bonding pads on the active surface of the chip. The leads having an inner lead portions and an outer lead portions are disposed at the periphery of the die pad, and the inner lead portions are electrically connected to the bonding pads by a plurality of bonding wires. The molding compound encapsulates the chip, the die pad, the inner lead portions of the leads, and the bonding wires. The second surface of the die pad is exposed on the top surface of the package structure while the outer lead portion of the leads is exposed at the side edge of the package structure.