Mechanical properties of Cu3Sn/Cu interface under thermo-mechanical coupling:A molecular dynamics study
The Cu3Sn/Cu interface is an important component of the solder joints.The Kirkendall voids gathered near the interface are likely to generate microcracks under tensile loading,leading to the failure of the solder joints.The effects of the strain rate and temperature on the mechanical properties of the Cu3Sn/Cu interface under thermodynamic coupling field were investigated by molecular dynamics.The results show that the plastic deformation of the Cu3Sn/Cu interface is obvious when the strain rate is low.The elastic deformation dominates in the high strain rate range,and there is no obvious yield point in the tensile process.The equivalent modulus of elasticity,yield strength,and tensile strength all increase with the strain rate at temperatures from 300 to 450 K.The Cu3Sn/Cu interface exhibits plastic deformation at high temperatures,and more likely exhibits elastic deformation at low temperatures.The equivalent modulus of elasticity,yield strength and tensile strength all decrease approximately linearly with increasing temperature at the strain rates from 0.0005 to 0.05 ps-1.