Correlation between power cycling and thermal cycling fatigue reliabilities of chip-scale packages

In this paper, the sequential thermal-mechanical coupling analysis, which solves in turn the transient temperature field and subsequent thermomechanical deformations, was carried out to investigate board-level fatigue reliabilities of TFBGA under accelerated power cycling test conditions. Experiments for steady state and transient thermal dissipations were conducted to verify the thermal analysis. Comparing between numerical results for power cycling and thermal cycling, it is noticed that for the tests similar low and high temperature extremes, power cycling leads to a much longer fatigue life than thermal cycling does, which indicates that thermal cycling is a more conservative criterion than power cycling is in evaluating the fatigue resistance of the electronic packages.