ABSTRACT
This chapter is concerned with electrically conductive adhesives. There were already formulations on the books at Hughes Aircraft Company for silver-filled rigid epoxy adhesives. It was a simple matter of adding DuPont's V-9 silver powder to an epoxy mixture in sufficient quantity to get electrical conductivity. The electrically conductive adhesive National Center for Manufacturing Science (NCMS) 7430 is the result of a very extensive formulation development effort. The early part of the NCMS effort involved evaluation of 25 commercially available electrically conductive adhesives. If formulators are formulating to meet a new set of property requirements, a practical approach would be to first optimize the flexible epoxy or other rubbery polymer adhesive, and second to find the optimum silver particle for that polymeric adhesive. Patent 5,575,956 covers the technology behind formulating a room temperature-stable, one-component, electrically conductive flexible epoxy adhesive. Although the feasibility of such an adhesive was proven, minimal characterization was done.
