In this work, a sinusoidal vibration test method with resonance tracking is employed for reliability testing of circuit assemblies. The system continuously monitors for changes in the resonant frequency of the circuit board and adjusts the excitation frequency to match the resonant frequency. The test setup includes an electrodynamic shaker with a real-time vibration control, resistance monitoring for identifying electrical failures of interconnects, and vibration logging for monitoring changes in the dynamic response of the assembly over time. Reliability tests were performed using the resonance tracking sinusoidal test method for assemblies, each consisting of a centrally mounted ball grid array (BGA) device assembled with 63Sn37Pb and SAC105 solder alloys. These tests show that the resonance tracking method gives more consistent failure times. Failure analysis for the tested devices shows the primary failure mode is “input” trace crack first, followed by fatigue through the solder for complete failure. A finite element (FE) model, correlated with experimental modal analysis, is shown to accurately estimate the circuit board deflection estimated from the harmonic vibration data. This provides a means of estimating the stresses in the electronic interconnections while accounting for the variability between test parts. These fine-tuned vibration measurement techniques and related FE models provide the building blocks for high cycle solder fatigue plots (i.e., S–N curves).

Purpose This paper aims to investigate and compare the reliability performance of land grid array (LGA) and ball grid array (BGA) solders, as well as the SAC105 and 63Sn37Pb solder alloys, in vibration loading conditions. Design/methodology/approach Reliability tests were conducted using a sine dwell with resonance tracking vibration experiment. Finite element simulations were performed to help in understanding the observed failure trends. Findings Reliability results showed that the tin-lead solders out-perform lead-free solders in vibrations loading. Additionally, the LGA solder type could provide a better vibration reliability performance than BGA solders. Failure analysis results showed that in LGAs, the crack is initiated at the printed circuit board side and at the component side in BGAs. In both types, the crack is propagated throughout in the intermetallic compound layer. Originality/value In literature, there is a lack of published data in the comparison between LGA and BGA reliability performance in vibration loadings. This paper provides useful insights in the vibration reliability behavior of the two common solder joint types.

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