Process induced residual stresses in isotropically conductive adhesive joints

Mechanical and thermomechanical tests were conducted to characterize conductive adhesives in terms of dimensional stability and viscoelastic properties. Dynamic testing results were converted from the frequency domain into the time domain. Those results were then incorporated into the ABAQUS finite element (FE) code, in which a finite element analysis (FEA) was conducted to investigate the stress development and stress relaxation process in the conductive adhesive joints by taking into account the viscoelastic properties of the conductive adhesive. Experimental results showed that the stresses in the conductive adhesive can relax significantly at elevated temperatures. Based on the experimental data and FEA result, a new cure schedule is proposed for the conductive adhesive studied.