Mechanical property evaluation of nano‐silver paste sintered joint using lap‐shear test

Purpose The purpose of this paper is to evaluate the mechanical properties of nano‐silver paste sintered lap shear structures and to discuss the effects of loading rate and ambient temperature on shear strength and fracture mechanism. Design/methodology/approach Single lap shear joints with an area of 2 mm 2 and thickness of 50 μm were fabricated by joining two copper substrates with nano‐silver paste. The lap shear tests were carried out under strain control mode on a micro uniaxial fatigue testing system with four loading rates and temperatures. The fracture sections were analyzed by SEM observation to determine the effect of temperature on the fracture mechanism. Findings Results from the study highlighted that the shear strain rate and temperature can have a significant impact on the shear behaviour of nano‐silver paste sintered lap shear joints. The shear strength increased with shear strain rate, but decreased with increasing ambient temperature. The lap shear joints displayed excellent ductility at higher temperatures due to the grain plastic flow. Originality/value So far, the investigation of the mechanical behaviour of low‐temperature sintered nano‐silver paste was restricted to a film form. No work had been done on nano‐silver paste connected structures. The findings presented in this paper give a basic understanding of the mechanical properties of nano‐silver sintered joints when sheared under different loading rates and temperatures.