Effect of relative humidity on the corrosion behavior of Sn–0.7Cu solder under polyvinyl chloride fire smoke atmosphere

Abstract

AbstractThe effect of environment relative humidity (RH) on the corrosion behavior of Sn–0.7Cu solder was investigated by the weight loss method and surface characterization techniques. In this study, RH ranging from 50% to 98% was researched. The results show that the corrosion degree is getting worse from 50% RH to 90% RH. However, the corrosion rate at 98% RH is lower than that at 90% RH, which may be ascribed to the degree of oxygen diffusion in electrolyte layers of different thicknesses. The microstructure characterization proved that the corrosion products exhibit a superimposed growth and present the same corrosion degree variation trend as the corrosion kinetics. The compositions of corrosion products are examined, and Sn21Cl16(OH)14O6, SnO, and SnO2 are the main corrosion products.