SEMICONDUCTOR CASING

摘要

A hermetic semiconductor casing for an electrical component has a metal or metal alloy leadframe with first and second opposite surfaces each having a first refractory oxide layer thereon, which leadframe is adapted to have the electrical component connected thereto. The leadframe is bonded by means of a fired glass or ceramic to a metal or metal alloy base member. The base member has a relatively thin metal or metal alloy coating on at least the top surface and the sides thereof, with the coating having a desirable refractory oxide layer on the outer surface thereof. The leadframe is also bonded by means of a fired glass or ceramic to a metal or metal alloy cap member having a refractory oxide layer on the lower surface thereof. The coating on the base member allows use of a base member that has undesirable oxide forming characteristics. Its thinness improves heat transfer over the use of cladding and its oxide layer on the sides of the base member provides for bonding to any glass that may flow over the edge of the base during firing that could otherwise break or spall off and cause faults in the dielectric separation of the base and the leadframe and destroy the hermetic seal of the casing.