Method of manufacture of solderable thin film microcircuit with stabilized resistive films

Abstract

Abstract A metalization process for the manufacture of hybrid integrated circuit elements including boards and semiconductors to be attached thereto involves applying to a substrate of insulating material such as aluminum oxide, successive layers of sputtered nickel-chromium and nickel, an electroless deposit of nickel-boron and, frequently, an electro-deposited layer of gold. The assembly is then normally heat-treated to stabilize the resistive layer. The addition of the nickel-boron layer provides many advantages in that reliable low-temperature solder connections may be made to it, ultrasonic wire bonds of high reliability may be accomplished with the usual aluminum wire supplied with most discrete components, the heat-treating step is considerably shortened in time with greater stability of resistance values, and the assemblies thus manufactured are capable of operating in comparatively high-temperature environments. The same metalization process applied to semiconductors renders them easily solderable and avoids using high temperature eutectic bonding with the accompanying exposure of the semiconductors to elevated temperatures, often for prolonged periods. As a result, circuit assemblies thus manufactured are readily repairable, in most instances, since no high-temperature bonds are required.

Inventors

• 👤 Gordon J. Estep
• 👤 Bernard Lee Burton

Bibliographic Details