Board Level Power Cycling and Thermal Cycling Fatigue Reliability 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 reliability of a thin profile and fine pitch ball grid array (TFBGA) chip-scale package 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 with similar low and high temperature extremes, power cycling results in a much longer fatigue life than thermal cycling, which indicates that thermal cycling is a more conservative criterion than power cycling is in evaluating the fatigue resistance of the electronic packages.