Georgia Tech is testing conductive adhesives as a potential alternative to tin-lead solder. Electronics Weekly reports that Georgia Tech professor C.P. Wong who is working on adhesive technology believes the Georgia Tech team is making progress on improving the properties of conductive adhesives.
Conductive adhesive consists of glue filled with metal powder. One technology Wong is working on involves self-assembling molecular conductors that provide a direct connection through the adhesive. Wong admits that the adhesives by themselves do not measure up to metallic solders, but he notes that when the adhesive is incorporated in self-assembled mono-layers the electrical conductivity and current-carrying capability compares well with traditional solder joints.
Another issue Wong is working on is the decreasing performance of adhesives when exposed to high humidity over an extended period of time. He blames oxidation for the decreased performance. He is currently testing materials such as acid that may inhibit the oxidation.