A model of Three Dimensional (3-D) shape of solder joint in optical fiber attachment soldering and the energy boundary condition were established.The 3-D shape of solder joint was predicted by employing Finite Element Method (FEM)

and the influence of various factors

which include material and manufacture parameters

on 3-D shape of solder joint was discussed.Based on the minimum potential energy theorem and the data from shape simulation

the influence of solder volume and pad size on the stand-off height (SOH) between optical fiber and pad was analyzed

the effects of y-offset on the restoring force were investigated.The results show that the minimum stand-off height increases linearly with the increase of solder volume for certain pad size when solder volume is larger than the critical value.The restoring force increases linearly with the increase of y-offset when the y-offset is smaller than certain value.The above results are of great importance and can be used to control the offset of alignment by modifying the design and manufacture parameters.