Copper-based conductive polymers: A new concept in conductive resins

The history of making plastic materials conductive to both electric currents and to the transfer of thermal energy has traditionally been accomplished by the addition of metallic particles into a resin matrix. Principally, such metals as aluminum, silver, gold, nickel and copper have been used. Copper has had a limited success due to its tendency to form a non-conductive oxide surface layer and currently such adhesives depend primarily on silver for high conductivity. An intense research effort to eliminate the problems associated with copper-filled conductive polymers resulted in a treatment and preparation of copper Rake that allows the stable formation of a conductive structure within a polymer matrix. Once the activated copper particles are in the resin, the formulation is stable. Most of the resins evaluated have been epoxy resins although certain thermoplastic resins have also been made conductive. Volume resistivities as low as 10(-5) ohm-cm have been achieved.