Thermal cycling aging effects on Sn–Ag–Cu solder joint microstructure, IMC and strength

Abstract Thermal cycling aging studies on a lead-free 95.5Sn–3.8Ag–0.7Cu solder joint were investigated. Soldered lap joint specimens were fabricated by a solder reflow process using a 95.5Sn–3.8Ag–0.7Cu solder sphere, no-clean flux on FR4 substrate parts. Characterization of the solder joint microstructure, intermetallic compound (IMC) and shear strength was conducted. Studies on the effects of thermal aging on IMC thickness and residual shear strength properties before and after exposure to thermal cycling aging are presented. Temperature cycling aging experiments based on standard thermal cycling (TC) and thermal shock (TS) tests were conducted on the lap joint specimens. IMC growth behavior and shear test results for specimens subject to thermal cycling aging.