The Sintering Behavior of Electrically Conductive Adhesives Filled with Surface Modified Silver Nanowires

摘要

Electrically conductive adhesives (ECAs) filled with sintered silver nanowires were prepared and the effect of different curing conditions on the electrical property of the ECAs was discussed. Silver nanowires with a diameter of 50-60 nm and a length of 2-3 um were successfully synthesized through a polyol process and surface functionalized with dicarboxylic acid. Morphology studies showed that surface modified silver nanowires began to sinter at 200° C and became shorter and thicker, and eventually formed large chunks at higher temperatures. The conductive adhesives filled with 75 wt% of silver flakes and nanowires (3:2 weight ratio) were cured at different temperatures using two kinds of catalysts. The volume resistivity of the conductive adhesives cured at 300°C without a catalyst reached 5.8 x 10~(-6) Ω cm. The dramatic improvement in the conductivity of the ECA is due to the sintering of silver nanowires and the high solid content resulting from the partial evaporation of polymer components.