The phenomenon of tin pest: A review

This paper presents a comprehensive review of the tin pest phenomenon research and focuses on new experimental data regarding the formation of tin pest effects. The data presented and analyzed here enable manufacturers to make the right decisions when choosing a tin-based alloy for low-temperature applications. Suggestions on how this information affects the lead-free industry and recommendations for future work to clarify and evaluate the occurrence of tin pest for electronic circuits are presented. Common arguments about the risks of using tin, especially whether tin alloys are acceptable for low-temperature applications and whether lead-free solders should be exempt from regulations, are also discussed. The common assumptions are: (1) lead-free alloys can be safely used in low-temperature applications if solder paste joining technology is used, and (2) joints from solder paste benefit from both the presence of flux residues and tin oxide particles, which combined make the allotropic transformation extremely unlikely. Based on the data discussed in this review, an appendix summarizes the tin-pest-retarding effects on lead-free alloying metals.