Effect of temperature on the corrosion behavior of lead-free solders under polyvinyl chloride fire smoke atmosphere
Qian Li, Mengke Zhao, Jin Lin, Shouxiang Lu
Abstract
Fire smoke could induce serious corrosion damage to electronic equipment away from the fire, causing significant economic losses. And lead-free solders used for chip package is the key to ensure the reliability of electronic equipment, which is vulnerable to corrosion. Therefore, it is very important to explore the corrosion hazard of fire smoke on lead-free solders for evaluating the reliability of electronic equipment after a fire. In this work, the effect of temperature on corrosion behavior of SAC305, Sn-0.7Cu, and Sn-37Pb solders under polyvinyl chloride fire smoke atmosphere was performed with the weight-loss method. The corrosion kinetics, corrosion morphology, and corrosion products were analyzed in the temperature range of 10 °C–50 °C. The corrosion kinetics results showed that the corrosion degree of all three solders aggravated linearly with rising temperature in that order: SAC305 > Sn-0.7Cu > Sn-37Pb. The corrosion of lead-free solder was more susceptible to temperature variation, and Sn-0.7Cu solder was the most serious. The corrosion morphology analysis exhibited that obvious corrosion traces had presented at 10 °C, and a great deal of large and thick corrosion products appeared at 50 °C. All solders presented galvanic corrosion under polyvinyl chloride fire smoke atmosphere. The corrosion products of lead-free solders were Sn 21 Cl 16 (OH) 14 O 6 , SnO, and SnO 2 , but those of Sn-37Pb solder contained Sn 21 Cl 16 (OH) 14 O 6 , PbCl 2 , SnO, and SnO 2 . The results could guide the formulation and implementation of rescue measures for electronic equipment post-fire.