Solder interconnect failure is a known life limitingfailure mechanism that is induced by cyclic temperatureexcursions. Thermal fatigue reliability of solderinterconnects is conventionally assessed by simpletemperature cycling test, which applies a constanttemperature range, fixed dwell times and ramp ratesduring the test. However, due to the user controlled powercycles, non-constant workloads, and changes in thesurrounding environment, electronics in the field oftenexperience a complex combination of temperature andpower cycling.In this study, the effect of power cycling superposed on asimple temperature cycling is experimentally examined.Furthermore, a scheme for modeling the solderinterconnect fatigue life of Plastic Ball Grid Array (PBGA)parts under the concurrent power and temperature cycling.Damage, defined as the number of applied cycles over thenumber of survivable cycles, from the simple temperaturecycle and the power cycle are linearly added using Miner’srule, and compared with the concurrent temperature andpower cycling test. Cycles to failure of each condition isderived by life testing conducted on Plastic Ball Grid Array(PBGA) assembled with eutectic and SAC305 solder.
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