Electromigration damage mechanics of lead-free solder joints under pulsed DC: A computational model

► Vacancy, stress and damage evolution of solder joints under PDC is investigated. ► An electromigration and thermomigration damage model is proposed. ► Frequency, duty cycle and current density dependence of damage is investigated. ► SEM images show that vacancy accumulates only at skin layer of solders. ► A mean time to failure equation is proposed for solder joints under PDC loadings.