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.

Head gimbals assembly (HGA) an important part in hard disk drive is made by assembling slider on suspension by using an epoxy adhesive. In production process there are three main problems originated from epoxy adhesive which are the instability of adhesive’s viscosity while it is in an operation air bubble in adhesive and low degree of curing which is not enough to adhere slider on suspension. The instability of adhesive’s viscosity was solved by preheating the adhesive at 60oC for two hours before use but it may be unsuitable because the viscosity increased due to curing reaction and adhesive’s properties are changed. Air bubble in the adhesive was removed by the supplier using a degassing method and vacuum centrifuge. Contamination from a surfactant for decationization on surface of suspension and a cleansing agent for cleaning slider before assembling HGA process they could act as inhibitors of curing reaction which is evidenced by the Differential Scanning Calorimetry (DSC) pr