The Reliability of the Complex Components under Temperature Cycling, Random Vibration, and Combined Loading for Airborne Applications

Abstract

The electronic devices suffer great vibration and temperature fluctuation in an airborne environment, which has been always a big challenge for reliability design. In this paper, the reliability of the complex electronic components for airborne applications under a thermal cycling test, random vibration and combined loading has been investigated by experiment tests and finite element simulation. The fatigue life and failure location under different loadings have been compared and discussed, respectively. The results indicated that the combined fatigue life was much shorter than a single-factor experiment. The failed solder joints mostly appeared at the interface between the solder and the copper pad on the component side and the location was at the corner for all three harsh environment tests. Nevertheless, several differences could be observed. For temperature cycling, all the specimens failed due to the increase in daisy chain resistance rather than the open circuit for the combined loading test. That is because the degeneration of the solder caused by temperature variation led to lower stress levels and fatigue life. Moreover, the pins fractured at the welding regions have been observed. The modified Coffin—Manson model, Miner’s linear fatigue damage criterion and Steinberg’s model and rapid life-prediction approach were used to predict the fatigue life under temperature cycling, random vibration and combined loading, respectively. With these methods, the accurate numerical models could be developed and validated by experiment results. Thanks to the simulation, the design time could be effectively shortened and the weak point could be determined.