The study of problems of epoxy adhesive on head gimbals assembly process

Abstract

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