Abstract: Tensile properties and fracture mechanism of Sn3.0Ag0.5Cu/Cu solder joints aged at 150℃ for different time were investigated at the strain rates of 2×10^-4,2 × 10^-2 and 2s^-1.Experimental results show that the strain rate plays a significant role in the strength and the fracture behavior of the solder joints.The tensile strength of the solder joints increases with increasing of strain rate.The solder joints fail in a ductile mode within the solder at the low strain rate,but fail in a brittle mode inside the IMC layer at the high strain rate.