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

Abstract

A semiconductor device includes a die pad, a semiconductor element which is loaded on the die pad, and a sealing resin. A plurality of electrically conductive portions each having a layered structure including a metal foil comprising copper or a copper alloy, and electrically conductive portion plating layers provided at both upper and lower ends of the metal foil are arranged around the die pad. The die pad has a lower die pad plating layer, and the semiconductor element is loaded on the die pad comprising such a die pad plating layer. Electrodes provided on the semiconductor element are electrically connected with top ends of the electrically conductive portions via wires, respectively. The lower electrically conductive portion plating layers of the electrically conductive portions and the die pad plating layer of the die pad are exposed outside from the sealing resin on their back faces.