SEMICONDUCTOR DEVICE

PURPOSE:To restrain the deterioration in the reliability upon a semiconductor device during the circuit substrate packaging step while enhancing the heat dissipation effect in operation time for improving the productivity in relation to the semiconductor device using a semiconductor chip mounting substrate. CONSTITUTION:After wire-connecting the connection electrode of a semiconductor chip mounted on the stage 11a of a chip mounting substrate to the corresponding inner lead part on the mounting substrate, at least the stage 11a on one surface and a multitude of wiring patterns 11b whose one end is connected to the inner lead part 11b-1 positioned around the stage 11a while the other lead parts 11b-2 are arranged on the other end positioned around the periphery of the substrate are pattern-formed. On the other hand, the rear surface of the substrate is coated with a metallic layer lid while the outer lead parts 11b-2 are bent on the wiring pattern formation surface side in the wiring pattern formation region so that the end sides of the outer lead parts 11b-2 may be aligned on the same surface.