Electroplating of thick film circuitry

Abstract

The improved circuit composite of the present invention is of the thick film type, but is readily solderable, weldable and bondable to wire without oxidizing. The composite comprises a refractory substrate such as alumina, beryllia or zirconia, a thick printed film pattern of oxidizable electrically conductive metal such as copper, nickel, or silver bonded to the substrate, and a thin electroplated film of non-oxidizable electrically conductive metal, such as gold or platinum, enclosing and adhering to the thick film pattern. The then-electroplated film allows wires and contacts to be soldered, welded or bonded to the pattern, as by ultrasonic or thermocompression bonding, without degrading the quality of the contact area and while permitting removal and subsequent reattachment of such wires and contacts. The method is simple, inexpensive and efficient. It calls for forming the thick film on the substrate and then electroplating the thin film thereover. The method results in durable circuit composites, particularly microcircuit composites of high quality and improved utility.

Dependencies are inferred from the claim text.