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

Abstract

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.

Keywords:

• Conductive adhesives
• lap-shear
• loading rate
• shear stress distribution
• shear properties

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The authors gratefully acknowledge financial support from the National Natural Science Foundation of China [Grant nos. 11802198 and 11772217], and the Fundamental Research Funds for the Central Universities [Grant no. xzy022019016].