The present invention relates generally to wire bonded integrated circuit packages and, more particularly, to methods and arrangements for isolation and reinforcement of individual bonding wires in integrated circuit packages.
In a wire bonded integrated circuit package, a die is attached and wire bonded to a lead frame (or other substrate) and then molded. During the molding process, the flow of the mold may displace some bonding wires, a phenomenon commonly referred to as “wire sweep”. As a result of wire sweep, some displaced bonding wires may come in contact with other bonding wires and produce short circuits. Wire sweep generally causes a decrease in package yields, since packages with shorts are rejected (“short rejects”). In other situations, wire sweep may push adjacent bonding wires closer together than is desired even though they do not actually touch. This can lead to increased inductive coupling and/or crosstalk interference between adjacent bonding wires, which can decrease the performance of the resulting packaged integrated circuit and lead to further reductions in package yields.
One approach to addressing the wire sweep problem has been to insulate the bonding wires before molding. By way of example, U.S. Pat. Nos. 5,455,745 and 5,527,742 describe methods of insulating bonding wires. Although the existing wire insulation techniques work well, in the semiconductor industry, there are continuing efforts to improve packaging techniques and/or reduce costs.