Effect of silver nanostructures on the resistivity of electrically conductive adhesives composed of silver flakes

Silver flakes are the most widely applied conductive fillers in electrically conductive adhesives (ECAs) because of their high conductivity and stable chemical properties. It is expected that there are advanced ECAs with both high electrical conductance and good adhesive strength. The high filler loadings can improve the conductance of ECAs, whereas the adhesive strength is decreased. Silver nanostructures are incorporated for the purpose of electrical conductance and adhesive strength improvement of ECAs. A simple method has enabled the synthesis of silver nanostructures by reducing silver nitrate with ethylene glycol in the presence of poly(N-vinylpyrrolidone). They are added to ECAs by dispersing them in ethanol while it is used as the diluent to adjust the volatility of ECAs, preventing them from the aggregation. This proposed process offers the possibility to effectively use silver nanostructures for improving the conductivity of ECAs at the low content of conductive fillers while good adhesive strength may be obtained.