Encapsulated semiconductor device having a hanging heat spreading plate electrically insulated from the die pad

Claim 1

A packaged semiconductor device comprising: an electrically conducting lead frame including a plurality of connecting leads, each connecting lead having a first end and a second end, the first ends of the connecting leads lying substantially in a first plane, a die pad having an area and lying in a second plane generally parallel to and spaced from the first plane, and a plurality of first hanging leads extending from the first plane to the second plane and supporting the die pad; a semiconductor chip having opposed first and second surfaces and a plurality of electrodes disposed on the first surfaces wherein the second surface of the semiconductor chip is bonded to the die pad and the first ends of at least some of the connecting leads are electrically connected to corresponding electrodes; heat spreading plate spaced from, directly opposite, and electrically insulated from the die pad, having an area larger than the area of the die pad for dispersing heat produced by the semiconductor chip, and including a plurality of second hanging leads connected to the heat spreading plate, supporting and extending from the heat spreading plate to and terminating substantially in the first plane, the second hanging leads being respectively disposed between and electrically insulated from pairs of the connecting leads; and a resin package encapsulating the semiconductor chip, the die pad, the second ends of the connecting leads, the heat spreading plate, and the second hanging leads wherein a portion of the resin package is disposed between and separates the heat spreading plate from the die pad.