Accelerating the Temperature Cycling Tests of FBGA Memory Components with Lead-free Solder Joints without Changing the Damage Mechanism

摘要

The paper reports a comprehensive study on accelerated temperature cycling tests. Based on a DoE test plan, multiple accelerated temperature cycling tests were performed on different SMT soldered 512Mb FBGA daisy chain packages. The thermo-mechanical behavior of two SnAgCu solder alloys was studied. A sensitivity analysis assessed the effects of the TC stress tests factors on the characteristic lifetime. No change in failure mode was seen. The solder interconnect fracture due to solder creep is most sensitive to the magnitude of extreme temperatures and the temperature difference only. Dwell time and ramp rate may be chosen to minimize test time to failure. Applying a log-linear response surface analysis, a quantitative correlation between all factors has been established. In addition, three acceleration factor models have been assessed. They are all applicable to transform the TC test result among the parameter space of different thermal profiles but show slightly different accuracy.