Fatigue life prediction of solder joints with consideration of frequency, temperature and cracking energy density

• A fatigue life prediction equation as a function of temperatures, frequencies and CED was proposed.
• The fatigue life prediction equation represented test data very well.
• CED was shown to be a good physical quantity in fatigue life prediction.
• The fatigue life of BMS(Battery Monitoring System) could be predicted.
• In the fatigue life prediction of BMS, the confidence level and prediction level were obtained as well.

Solder joints between semiconductors and a printed circuit board may fail due to temperature change or vibration. To assess the durability of solder joints a mechanical fatigue test was conducted instead of a thermal cycling test, and a resistance change was monitored to detect a failure at real time. Fatigue tests were conducted for five different semiconductors at three different frequencies, temperatures and displacements, and a fatigue life prediction equation with consideration of frequency, temperature and cracking energy density was proposed. It was shown that all the fatigue test data could be represented appropriately by the prediction equation.