Thermal fatigue test of electronic packages under temperature cycles

Abstract

Equipment has been developed with which almost rectangle temperature cycles can be carried out. The drop‐down of electric voltage for each chip in an electronic package is recorded for the thermal cycles. From the SEM observation of the specimens cut from the chips endured different temperature cycles, it is found that there is a strong interrelation between the fatigue damage and the drop‐down value of electric voltage. It is also noticed that when the fatigue crack initiates from the interface edges, the drop‐down value will increase dramatically. An experimental criterion for the evaluation of chip’s fatigue life based on the drop‐down of electric voltage is proposed. The fatigue life of different chips is obtained under different temperature cycles from the criterion.

Keywords:

• Power module
• Thermal shock
• Thermal fatigue
• Electronic package
• Interface
• Damage

The research work was supported by the National Natural Science Foundation of China (NSFC) (grant no. 10772116, no. 10772115, no. 10932007).