An Efficient Response Spectrum Method for Fatigue Life Prediction of Electronic Packaging Solder Joints

Abstract

This paper presents an efficient response spectrum method for the fatigue evaluation of electronic packaging solder joints subjected to random excitations. Firstly, a particular modal expression for the stress power spectral density is derived to deal with the coupling of multiaxial stresses and the stress singularities in solder joints. Secondly, the stress spectral moment is rapidly evaluated by summing the modal contributions. The procedure decouples the spatial and frequency information inherent in the spectral moment. Then, a fatigue damage response spectrum, independent of structural characteristics, is defined using the single-moment method. Finally, two new combination formulas are formulated to simplify the fatigue assessment into the weighted combination of modal damage responses. Compared to traditional frequency-domain methods, the proposed method avoids the calculation of the stress power spectral density and the spectral moments, significantly enhancing the efficiency of fatigue life assessment while maintaining excellent accuracy and stability.