Processing and shape effects on silver paste electrically conductive adhesives (ECAs)

Various amounts of silver flakes and dendrites were used as conductive fillers in an electrically conductive adhesive (ECA) resin with DPM, BCA and xylene as diluent to help uniform distribution of filler particles in the matrix. Due to the fact that the higher the temperature, the higher the shrinkage rate of the polymer resin and, consequently, the larger the connecting area in-between fillers, a better curing condition for processing silver filled ECA was found to be a relatively higher curing temperature. The mechanism of conductivity achievement in conductive adhesives was analyzed by comparing processing conditions, resistivity and microstructures. In addition, the influence of adding nano-sized silver particles on the resistivity of the conductive adhesives was also investigated and the addition of nano-sized silver particles resulted in a lower percolation threshold for ECAs.