Abstract
In recent years, the decrease in fatigue life of solder joints at high temperatures has been a major problem in semiconductor packages for automotive applications. In this paper, to improve the accuracy of predicting the fatigue life of solder joints when considering high-temperature degradation, we studied the correlation between high-temperature holding conditions and the decrease in fatigue life by using the mechanical fatigue test results of solder joints after high-temperature holding. The decrease in the fatigue life of solder joints after high-temperature holding was explained by the change in the fatigue ductility coefficient of Coffin-Manson’s law, and this fatigue life decrease can be quantitatively estimated using Arrhenius’ law with the holding time and holding temperature. We found that the fatigue life predicted by Miner’s law using the fatigue ductility coefficient under the test conditions of thermal cyclic tests agreed well with the experimental results.
