Effect of temperature on vibration fatigue of SAC105 solder material after extended room temperature aging

Electronic products are often exposed to combined stress loading conditions (both thermal excursions and vibration) during their service life. In order to assess the performance and durability under these conditions, it is important to use temperature dependent fatigue data to assess or more accurately predict vibration damage under more realistic life-cycle conditions. This paper focuses on finding the temperature dependent vibration durability of aged SAC105 solder material. This is accomplished by using a combination of harmonic vibration tests at different temperatures and nonlinear dynamic FEA. The fatigue durability is found to decrease significantly with increasing temperature, in part due to the increase in solder strain, and in part due to degradation of the solder cyclic fatigue properties. Additionally, the room temperature fatigue results were fitted with the Basquin-Coffin-Manson fatigue model to produce the temperature-dependent model constants for the S-N curves.