Packaged semiconductor die including heat sink with locking feature

Claim 1

Structure comprising: a semicondcutor die, the die having a first surface on which electrically conductive traces and a plurality of electrically conductive bond pads are formed, and a second surface, the second surface being opposite the first surface; a plurality of electrically conductive package leads, a lead tip of each of the package leads in proximity to the die; a plurality of electrically conductive bond wires, each bond wire connecting the lead tip of one of the package leads to a bond pad on the die; a heat sink, a first surface of the heat sink attached to the second surface of the die and to an inner portion of the leads, wherein a locking moat is formed in a locking surface of the heat sink between the die and the lead tips of the package leads, the locking moat having a cross-sectional shape, in a plane perpendicular to the locking surface, that has, at a first distance from the locking surface, a width that is larger than a width at a second distance from the locking surface, the second distance being smaller than the first distance; encapsulant encapsulating the die, the bond wires, the heat sink and the inner portion of the package leads such that the encapsulant interlocks with the locking moat to prevent the encapsulant from separating from the heat sink; a second plurality of electrically conductive bond wires, each bond wire of the second plurality connecting the lead tip of one of the package leads to a bonding location on the heat sink; and a third plurality of electrically conductive bond wires, each bond wire of the third plurality connecting a bonding location on the heat sink to a bond pad on the die.