Method for working-life enhancement of epoxy-based adhesive

Abstract

For one-part adhesive systems, a long working-life adhesive, which can be cured rapidly at processing temperature, is required in industrial applications because it provides assembly process versatility. The aim of this research was to study the methods for extending the working-life of an epoxy-based adhesive with anhydride curing agent. This adhesive formulation is used as an underfill material in electronic industry. The scope of this study was divided into two parts: 1) modification of adhesive formulation process, 2) determination of the component in adhesive which causes the adhesive viscosity increased at ambient temperature. The results showed that the adhesive working-life extended from 2 hours to 6 hours with reducing formulation process time, removing the moisture in filler and reducing fluxing precursor loading in adhesive. In addition, the fluxing precursor loading also affects the thermo-mechanical properties of adhesive. For characterization, the working-life and thermo-mechanical properties of this formulation were investigated using rheological technique and dynamic mechanical analysis (DMA), respectively.