Abstract An interconnection substrate is disclosed for use in hybrid microelectronic systems interconnecting transistors, resistive elements, semiconductor-integrated circuits, and other microelectronic circuit elements. The substrate consists of an insulative base and three metal films, for example, a first chromium film, a second gold film metallurgically bonded to the chromium film, and a third nickel film bonded to the gold. The interconnection substrate is prepared by (sequential) deposition of chromium, gold, and nickel onto a ceramic wafer. Alternatively the nickel film may be plated by other conventional methods. The desired circuit is then etched photolithographically to produce nickel pads for tin-lead soldered or welded connections. A second etching is made to produce gold pads suitable for thermal compression bonding, ultrasonic wire bonding and gold-silicon eutectic bonding. Circuits elements in the form of chips are then connected to the connection substrate and the entire unit encapsulated in a suitable protective material.
The interconnection substrate of claim 1 wherein said films are divided into a plurality of separate pads having at least two of said films, the pads being electrically insulated from each other.
Claim 2
Dependent Claim
19 words
The interconnection substrate of claim 2 including microcircuit elements connected to said pads and interconnected in a predetermined pattern.
Claim 3
Dependent Claim
18 words
The interconnection substrate of claim 1 wherein said noble metal is gold and said weldable film is nickel.
Claim 4
Dependent Claim
15 words
The interconnection substrate of claim 3 wherein said substrate is encapsulated in a protective coating.