Abstract: The present invention relates to a semiconductor device in which inner leads of a lead frame are electrically connected to a semiconductor chip, a method for producing thereof and a lead frame used therein. The object of the present invention is to improve a strength of the lead frame and a heat release efficiency in a small-size multi-pin type semiconductor device. In the inner lead of the lead frame, a thin plate portion is formed. The thin plate portions are secured on a heat spreader. A semiconductor chip is mounted on the heat spreader. The semiconductor chip is bonded to the thin plate portions of the inner leads through wires.

Abstract: A thin semiconductor device in which a strength of a lead frame and a heat dissipation efficiency can be improved. The semiconductor device has a semiconductor chip, a lead having an inner lead and an a outer lead continuing to the inner lead, said inner lead having a thin plate portion thinner than the other portion therof, said thin plate portion being electrically connected to said semiconductor chip through a wire and said outer lead serving as an outer connecting terminal, and a sealing resin sealing said semiconductor chip and at least a part of said lead, wherin said inner lead of said lead is positioned on said semiconductor chip.