The concept of relative damage stress and its application to electronic packaging solder joint reliability

A new mechanical concept, relative damage stress, which can mechanically reflect the failure mechanism of solder joints used in electronic packaging in full-scale, has been proposed. Based upon the new mechanical concept, the thermal fatigue life data of surface mount solder joints have been reasonably analyzed, something that traditional mechanical concepts, such as Mises equivalent stress, can not do. Some suggestions have been provided for the design of accelerated thermal fatigue tests of PCB-level electronic assembly.