Influence of corrosion properties on electrochemical migration susceptibility of SnPb solders for PCBs

• Published in: Metals and materials international Vol. 13; no. 2; pp. 129 - 137
• Main Authors: Yoo, Y. R., Kim, Y. S.
• Format: Journal Article
• Language: English
• Published: Seoul Springer Nature B.V 01.04.2007; 대한금속·재료학회
• Subjects: Alloys; Current density; Electric potential; Electrodes; Electronics; Failure; Lead (metal); Metallurgy; Migration; Solders; 재료공학
• ISSN: 1598-9623; 2005-4149; 1234-4320
• DOI: 10.1007/BF03027563

Electrochemical migration is caused by the adsorption of water and the bias voltages between the electrodes or pads which form an electric circuit or in the solders used to connect the parts. This work focused on the elucidation of the mechanisms of electrochemical migration of pure Sn, Sn37Pb, and Sn55Pb solders in electronics. The electrochemical migration behavior was discussed on the basis of the polarization behavior of SnPb solders. After the water drop test, the time to failure decreased with increasing Pb content in Cl^sup -^ solution and increased with increasing Pb content in SO^sub 4^ ^sup 2-^ solution. In the case of the SnPb solder alloys, the pitting potential, the passive current density, the cathodic current density and the efficiency of cathodic deposition of the alloying elements were closely related to the resistance of the electrochemical migration.[PUBLICATION ABSTRACT]