Plastic encapsulated semiconductor device and method of manufacturing

Abstract

A plastic encapsulated semiconductor device comprises a die pad, die pad support pins suspending the die pad, a semiconductor chip mounted on the die pad, thin metal wires for connecting the electrode of the semiconductor chip to leads, and a sealing resin sealing the foregoing components, while the respective bottom faces of the leads forming terminal portions are exposed. An upset process is performed with respect to the die pad support pins of a lead frame to form stepped portions such that the die pad is positioned higher in level than the leads. Since the lower portion of the sealing resin also underlies the die pad, enhanced adhesion is achieved between the die pad and the sealing rein, resulting in higher reliability. With the die pad positioned higher in level than the leads, there is no possibility of interference between the leads and the semiconductor chip even when the size of the semiconductor chip is freely changed. This enables the scaling up of a semiconductor chip and increases a packaging density in mounting semiconductor devices on a mother substrate.