Assessment of Accrued Damage and Remaining Useful Life in Leadfree Electronics Subjected to Multiple Thermal Environments of Thermal Aging and Thermal Cycling

Convergence of the damage mapping to a common solution from data based on the two separate leading indicators has been demonstrated. Assemblies subjected to sequential stresses have been prog- nosticated for accrued damage from sequential overlapping stresses of thermal aging and thermal cycling. Correlation between the prognosticated damage and the actual accrued damage demonstrates that the proposed approach can be used to assess damage accrued under overlapping thermo- mechanical stresses of thermal aging and thermal cycling.

In addition, prognostics metrics have been used to quantitatively evaluate the performance of the prognostic algorithms using both the leading indicators. Results demonstrate that both damage proxies work well in estimating accrued damage and estimating residual life.