Effects of reflow time on the interfacial microstructure and shear behavior of the SAC/FeNi-Cu joint

Abstract

Effects of reflow time on the interfacial microstructure and shear strength of the SAC/FeNi-Cu connections were investigated. It was found that the amount of Cu6Sn5 within the solder did not have a noticeable increase after a long time period of reflowing, indicating that the electro-deposited FeNi layer blocked the Cu atoms effectively into the solder area during a long period under liquid-conditions. The ball shear test results showed that the SAC/FeNi-Cu joint had a comparable strength to the SAC/Cu joint after reflowing, and the strength drop after reflowing for 210 s was less than that of the SAC/Cu joint.