Method of manufacturing insulated lead frame for integrated circuits

Abstract

An insulated lead frame for a semiconductor packaged device and a method of manufacturing both the insulated lead frame and the semiconductor packaged device are disclosed. The insulated lead frame has a first plurality of lead fingers and a second plurality of lead fingers. It also has the face of a power supply bus lying between the pluralities of lead fingers. An insulator covers the face of the power supply bus. An example of an insulator is a cured liquid polyimide. In a semiconductor packaged device using a lead on chip lead frame, such as a dynamic random access memory, DRAM, wire bonding that connects the power supply busses of the lead frame may first occur and the liquid insulator may afterwards be applied to the power supply busses. Alternatively, by knowing where the wire bonds will bond to the power supply busses, the liquid insulator may be applied to the power supply busses before wire bonding occurs. The bonding spots on the power supply busses are not covered with the liquid insulator. Both methods serve to reduce the possibility of shorting between the power supply busses and the crossing wire bonds that connect the lead fingers of the lead frame to the bonding pads of the integrated circuit.