Mechanical test assessment for electronic modules able to function in harsh conditions

The transition from through-hole technology to surface mount technology has increased the requirement for the reliability of the solder joint shear strength. The transition from lead to lead-free technology had issued new materials, but the most used alloy (SAC) offers an weaker shear strength to the solder joints than SnPb. The solder joints cannot fulfill the electrical and thermal functions if the mechanical function fails. The present paper focuses on some mechanical properties of the lead free solder joints, which have influence on joint reliability, as consequences of the process parameters and pad finishes.