Corrosion study of SN-BI lead-free solder in alkaline solution

This thesis study describes the corrosion analysis of Sn-Bi solder lead-free solder in alkaline solution which is potassium hydroxide (KOH). The corrosion potential and current of Sn-Bi in 6 M KOH solution was investigated. The potential sharply increases with increased immersion time before saturation at -1125 mV. Morphological and elemental analyses reveal the formation of oxides on the surface after immersion after using scanning electron microscope (SEM), energy dispersive X-ray (EDX) and X-ray diffraction (XRD). The result of morphology is mostly same as actual shape which are Sn matrix in plateau (dark contrast) meanwhile Bi-rich in lamellar eutectic structure (light contrast). In addition, phase and elemental analyses revealed the formation of mixed corrosion products of SnO, Sn02 and Bi203 on the surface after testing.