Loading rate response on shear mechanical properties of conductive adhesive with different silver contents

Epoxy-based isotropic conductive adhesives (ICA) have become the dominant materials in the microelectronic packaging field due to their advantages of low technological temperature, ultrafine line printing, and easy interconnection. During the service of electronic products, the ICA joints are subjected to shear loads induced by mechanical mismatch between packaging chip and substrate. In this work, the joint specimens with different contents of silver flakes (50 wt% and 70 wt%) prepared using pure copper plate adherend in the form of single-lap were used for the tensile-shear tests under different loading rates. The relationship between shear stress and location of the adhesive layer was theoretically derived. The interface fracture energy, shear strength, and fracture displacement of ICA, as well as concentration of shear stress in the adhesive layer, increase with the increase in loading rate. The shear stress concentration is relatively greater for the ICA with higher content of silver flakes.