WIRING BOARD

摘要

A wiring board having a reliable and cheaply fabricated wiring circuit which can be easily formed in a fine form enabling the semiconductor devices to be more densely integrated in further reduced thickness, reduced size and at reduced cost, the wiring board capable of being sealed in a plastic package. A thin dielectric film (2) is formed on the surface of a metal plate (1), and a semiconductor element (8) is mounted on the surface of the dielectric (2) or on the exposed surface of the metal plate (1). On the dielectric (2), thin multilayered wiring films (3), (4) and (5) are formed by sequential vapor deposition of a conductor layer of aluminum; an adhesive layer of chromium, or titanium or a laminate thereof; a diffused barrier layer of nickel, or copper or laminate thereof; and a corrosion preventing/wire-bonding layer of gold. The wiring may comprise an adhesive layer of any one of chromium, aluminum or titanium, or a laminate thereof, a conductor layer of copper and a gold layer that are formed in the order mentioned, or may comprise a conductor layer of aluminum, a barrier layer of nickel and a gold layer formed in the order mentioned. The thin-film wiring can be finely formed with ease enabling the wiring conductors to be highly densely fabricated. Moreover, the wiring composed of aluminum or copper can be cheaply formed.