a hybrid fem–weibull framework for vibration-induced fatigue life prediction and reliability enhancement of solder joints in space-grade pcb

The reliability of space-grade electronic boards is significantly compromised by vibration loads experienced during launch and orbital operations. these mechanical loads accelerate fatigue damage in printed circuit boards (pcbs) and their solder joints. most existing studies address individual factors and rely on simplified uniaxial analyses, which fail to capture the complex, multidirectional mechanical conditions present in real space environments. this study proposes a unified framework for vibration–fatigue prediction that integrates finite element modeling, frequency-domain stress analysis, and weibull-based life estimation. the proposed method enables the simultaneous evaluation of loading direction, package type, and solder alloy behavior. a multilayer pcb containing bga, lccc, and leaded packages was modeled, and both sinusoidal and random vibration loads were applied. simulations were conducted under both uniaxial and triaxial excitations. the results reveal key findings. triaxial loading significantly increases stress levels and uncovers failure modes not identified through uniaxial analysis. leaded packages demonstrate longer fatigue life due to the compliance of their leads. among the solder alloys, sac305 exhibits superior performance compared to pb90sn10 and sn100c. the finite element model directly correlates stress data with statistical life predictions, offering a realistic and quantitative understanding of vibration-induced fatigue. overall, the proposed method provides a practical and robust tool for designing more reliable space electronics.