A new creep–fatigue life model of lead-free solder joint

• Creep and fatigue damage are accumulated in different loading stage.
• A new life prediction model was proposed under high strain rate.
• Bilinear interaction diagram modification can improve the new model accuracy.

Life prediction plays an important role in reliability design of electronic product. Solder joint failure is one of the most common failure modes for electronic packaging structure. Current creep–fatigue life models of solder joints are unable to distinguish the creep damage and fatigue damage. In this work, a new creep–fatigue life model was proposed for solder joint tested under high strain rate, where the creep damage was based on Monkman–Grant equation and the fatigue damage was evaluated employing the Coffin–Manson model. Then, linear damage rule was utilized to build the new model. Creep test, fatigue test and creep–fatigue test were conducted respectively in order to determine the parameter in the new model. At last, the experimental result was compared with the predicted result, which shows that the calculation life meets well with the experimental life under high strain rate.