Preparation of Ag-Cu solid solution nanoparticles and the properties of low temperature sintered interconnect joint

Ag-Cu solid solution nanoparticles were prepared by liquid phase chemical reduction, and sandwich joints were prepared by low temperature hot pressing sintering process. The phase characterization of Ag-Cu solid solution nanoparticles and sinter was detected by X-ray diffraction. The elements of Ag-Cu solid solution nanoparticles prepared were characterized by energy disperse spectroscopy. The particle size of Ag-Cu solid solution nanoparticles was characterized by nanometer. The sintering structure and shear section morphology of the interconnect joints were observed by scanning electron microscopy, and the particle sintering situation and fracture mode of the interconnect joints were analyzed. The results showed that the supersaturated solid solution of Cu in Ag at room temperature was realized by liquid phase chemical reduction, in which the percentage of Ag atoms and Cu atoms was 62.29% and 37.71%, far exceeding the solid solution of conventional block materials at room temperature. The solid solution phase remained relatively stable within 250 ℃, and phase separation occurred at 260 ℃.When the sintering temperature is 300 ℃ and the sintering pressure is 20 MPa, the interconnect joints obtained have excellent mechanical properties, the average shear strength reaches 105 MPa, the sintered structure shows a complete vein shape, and the shear sections are all dimpled, which belong to ductile fracture.