EFFECT OF WELDING SEQUENCE ON WELDING-INDUCED-ALIGNMENT-DISTORTION IN FIBER-OPTIC DEVICE PACKAGING: PACKAGING OF BUTTERFLY LASER DIODE MODULE

摘要

The welding-induced-alignment-distortion (WIAD) is a serious issue in fiber-optic packaging using laser welding, which may significantly affect the packaging yield. An elimination or minimization of WIAD is expected to be possible if the welding process and other packaging parameters can be optimized. This work attempts to evaluate the contribution of laser welding sequence to the WIAD for butterfly laser diode packages. A realistic physics based laser welding model incorporating the spatial and temporal characteristic of laser beam and thermophysical material properties and absorptivity was developed and incorporated in the 3-D finite element model for the thermal induced stresses/strains and the resulting fiber alignment distortion as a function of welding sequence. An experiment study was conducted and the results agreed well with the finite element model in the way welding sequence affects WIAD. Both numerical simulation and experimental investigation suggest that WIAD reduction can be significant if an appropriate welding sequence is employed in the packaging of butterfly laser diode packages.