Novel conductive adhesives with stable conductivity and high impact resistance

Surface Mount Conductive Adhesives (SMCAs) provide an environmentally friendly solution for interconnections in electronic applications. In addition, SMCAs offer other attractive technical advantages over conventional Sn/Pb metal solders including low temperature processing and fine pitch capability. Two shortcomings of current commercial SMCA products are unstable electrical conductivity (contact resistance), under elevated temperature and humidity conditions, and inferior impact resistance of the adhesive interconnections. Systematic studies in the past have identified the fundamental mechanisms contributing to unstable contact resistance and poor impact strength of these SMCA materials. This paper will compare and contrast mechanical and electrical properties of several novel SMCAs that were developed utilizing two distinctly different material science approaches.