Electrochemical Corrosion Behavior of Sn–1.0Ag–0.5Cu and Sn–3.8Ag–0.7cu Lead Free Solder Alloys During Storage and Transportation Under Chloride Working Condition

The Continuous miniaturization of electronics set stringent requirements of corrosion resistance as imposed by high-density packaging. The present work elucidates electrochemical corrosion behaviours of two conventional lead-free solder alloys, i.e., Low-Ag (Sn–1.0Ag–0.5Cu, SAC105) and High-Ag (Sn–3.8Ag–0.7Cu, SAC387) solder alloys. The Electrochemical Impedance Spectroscopy and Potentiodynamic polarization performed in naturally aerated 0.5 M NaCl solution for 1 h, 24 h, 168 h, 336 h, 504 h and 672 h suggest that SAC387 solder offers higher corrosion resistance than SAC105 solder. The SAC105 solder is sparsely cover with fine-fibrous corrosion product, while platelet-like and fibrous mass entirely covers SAC387 solder. Microstructural and elemental characterization of corrosion product revealed the presence of tin oxide, Cu and Ag containing products as several pit, cracks and pore-like structures.