Temperature Dependent Mechanical Properties of Sintered Silver-Copper Joints

The focus of this work is investigation of the mechanical properties of low-temperature Ag-sintered large area joints which were prepared by using silver coated and blank copper substrates. Shear tests and stress relaxation experiments were conducted at various temperatures by using a micro tensile testing machine equipped with a thermal chamber. Fatigue behavior was studied by using a high frequency three point cyclic bending testing system. In order to compare the relaxation behavior at higher temperatures the stress exponents were deduced from measured data according to the creep law. Failure probability curves of sintered silver interconnections were plotted and compared with those of solder joints prepared with lead-tin-silver alloy. It was found that the sintering parameters, Ag-sinter layer thickness and the substrate material strongly affect the shear strength and fatigue response of the joints. Using scanning electron microscopy (SEM) and 3D-microscopy techniques allowed to obtain an insight into the failure mechanisms of the Ag-sinter joints subjected to static shear test and fatigue loading.