Finite element analysis on transient post-welding shift of opto-electronic pigtail package

We study the transient post-welding shift (PWS) of a TO-can pigtail package by three-dimensional finite element modeling (FEM) with thermo-mechanical coupling. The numerical approach provides a well-controlled welding configuration and helps us understand the scattering of experimental data. In our model we observe post-welding deformation for perfectly aligned welding structure while structural tilting occurs when we introduce weld spot offset. We also carry out experiment to measure transient PWS by noncontact displacement sensors. Simulation and experiment reveal that PWS of TO-can structure involves dynamical processes of multiple time scales.