EDS analysis on effect of low dosage gamma radiation and micromechanical properties of SnAg₃Cu_0.5 solder

Electronic applications are now driving packaging technology that is equivalent to primary computer packages for the past 25 years. The electronic application currently shows an ascending market demand due to rapid development of smart and wireless component with mixed technologies that include digital microprocessors. In ensuring the quality of the devices, the reliability of the solder joint is very vital. Attributable to their common uses, radiation particles including gamma ray is considered as one of the primary factors that could degrade the performance of the electronic devices. Thus, in this study, both mechanical and microstructure properties of lead-free solder joints radiated with gamma were investigated. Prior to the evaluation, the solder pastes of tin–silver–copper (SnAg₃Cu_0.5; SAC305) was manually deposited on the printed circuit board using a stencil printing method and reflow soldering process. Subsequently, the solder was exposed to low doses of gamma radiation. The current finding showed that as the radiation dose increased, the solder sample became softer and more plastic. FESEM and EDS analysis signified that intermetallic layer in the tin (Sn) matrix was dominated by Cu₆Sn₅ and Ag₂Sn compound. According to micromechanical investigation, both hardness and reduced modulus of the solder decreased with increasing the radiation dose that was due to microstructure change and the formation of voids.