Laser micro-welding of 40G optoelectronic butterfly package with submicron post weld shift

The effects of material selection, laser power, weld diameter/penetration, and beam balancing on post-weld-shift (PWS) during pigtailing of 40G optoelectronic modules have been numerically modeled and experimentally studied. The simulated welded joints were in very good agreement with measured results and were implemented into the process development phase to achieve the minimal laser energy required for a good quality weld. The 3-D finite element model qualitatively assess vertical and horizontal post weld shifts resulting from the unbalanced laser beam energy input. This work has led to an understanding of the effects of package construction and laser energy variation on the PWS, which may provide the design guidelines to reproduce a reliable, high yield laser module with high performance.