A rapid chemical method for improving peel strength at Cu–epoxy interfaces

The effect of a chemical treatment of a Cu surface on the interfacial strength between a thermoset polymer and that Cu surface has been determined. Spray technology was used to apply fixed amounts of a silane surface modifier to the cleaned Cu surface using three different plain-orifice atomizer hand-pump sprayers. The amount of spray coverage was determined for each sprayer as a function of the number of sprays and the peel strength was found to increase with the spray coverage for each sprayer. Substantial improvements to 340% in peel strength were achieved compared to the as-received condition, indicating good chemical bonding between Cu and epoxy. These results compare favorably with the results from a more complicated cleaning and oxidizing treatment which produced nano-scale features which mechanically interlock with the epoxy.