Quantitative characterization of optical fiber solder bond joints on silicon

Stress analysis of optical fiber solder bond joints on silicon substrates under thermal cycle loadings was investigated using 2-D and 3-D finite element analyses. Finite element simulations were carried out to investigate the effect of the distance between the fiber and the silicon wall for planar and v-groove solder attachment geometries. It was found that the maximum stress-strain along the interface of the solder and silicon substrate increases as the distance between the fiber and substrate decreases for both geometries. The solder bond strength under thermal loading was also examined to determine the influence of alternative solder material. Favorable results were obtained for 96.5Sn3.5Ag solder as compared to 80Au20Sn solder. Additionally, the reliability of the v-groove geometry is projected to be significantly less than an optimally designed planar bond geometry.