Patent ID: 7193328

Claim:
A semiconductor device comprising: (a) a semiconductor element, which is provided with a plurality of electrodes for input and output of an electric signal on the periphery of a bottom surface of the semiconductor element; and (b) a wiring substrate which is provided with: a film substrate, a wiring pattern formed on the film substrate and having at least one inner lead as a terminal portion, and a reinforcing film, made of material having smaller thermal expansion than the film substrate, and formed on at least one surface of the film substrate in a region of the wiring substrate where the wiring pattern is not formed and capable of substantially preventing the film substrate from expanding, wherein the semiconductor element is connected to the wiring pattern, and the semiconductor element and the wiring substrate are sealed with a resin, wherein said connection between the semiconductor element and the wiring pattern is a thermo-compressed bonded connection formed by thermo-compression bonding the electrodes of the semiconductor element to inner leads of the wiring pattern, the inner leads are aligned at positions corresponding to the respective electrodes, wherein said bonded connection is such that at least one inner lead of the wiring pattern directly contacts an electrode of the semiconductor element, wherein said reinforcing film is bonded onto the film substrate, and has sides, at least one of which extends along a direction in which the inner leads are provided, and wherein the height of the reinforcing film, measured from the surface of the film substrate on which the reinforcing film is formed, is one-third to two-thirds of the height of the wiring pattern.