WIRING BOARD

摘要

A wiring board having a wiring circuit which is reliable and which can be easily miniaturized, which is used for the production of a highly integrated, lighter, thinner, shorter, smaller and low-cost semiconductor device. This wiring board can be sealed in a plastic package. It comprises a metal plate (1) and a thin-film dielectric layer (2) formed on the surface of the metal plate. A semiconductor device (8) is mounted on the surface of the dielectric layer (2) or the exposed surface of the metal plate (1). Film wirings (3), (4) and (5) are formed on the dielectric layer (2). Each film wiring is in the form of a laminate formed by laminating, by vapor phase deposition or by plating, an aluminum conductive layer, an adhesive layer of chromium, titanium or a laminate thereof, a diffusion barrier layer of nickel, copper or a laminate thereof, and a corrosion-preventive and wire bonding layer of gold. Such wirings may be in the form of a laminate formed by laminating an adhesive layer of chromium, aluminum, titanium or a laminate comprising at least two of them, a copper conductive layer, and a gold layer or a laminate formed by laminating an aluminum conductive layer, a barrier layer of nickel, and a gold layer. Since the film wirings can be miniaturized easily, the density of wirings can be increased. Also, since the wirings are made of aluminum or copper, they are cheap.