Semiconductor device, substrate for producing semiconductor device and method of producing them

Abstract

A semiconductor device P includes a die pad, a semiconductor elementwhich is loaded on the die pad, and a sealing resin. A plurality of electrically conductive portionseach having a layered structure including a metal foilcomprising copper or a copper alloy, and electrically conductive portion plating layersprovided at both upper and lower ends of the metal foilare arranged around the die pad. The die padhas a lower die pad plating layer, and the semiconductor elementis loaded on the die padcomprising such a die pad plating layer. Electrodesprovided on the semiconductor elementare electrically connected with top ends of the electrically conductive portionsvia wires, respectively. The lower electrically conductive portion plating layersof the electrically conductive portionsand the die pad plating layerof the die padare exposed outside from the sealing resinon their back faces.