Microstructure and Mechanical Properties of Brazed Joints Used in Electronic Devices

Abstract：The microstructure and mechanical properties of brazed joints of oxygen-free copper and oxygen-free copper, nickel-plated kovar, monel, nickel-plated stainless steel were respectively studied by using AgCu28 and AuCu20 filler metal. Effects of different filler metal on microstructure of the brazed joints were analyzed through metallurgical microscope, SEM, EPMA. The brazed joints tensile strengths were analyzed through tensile test. The results indicate that the brazing process of oxygen-free copper and nickel content alloy used AgCu28 filler metal, nickel element is easy to diffused into AgCu28, AgCu28 filler metal with nickel element wetting spreadability along grain boundary of the oxygen- free copper, resulting in the penetration of the grain boundary of the oxygen-free copper. The joints brazed by AuCu20 filler metal have the better performance than the joints brazed by AgCu28 filler metal