The Coaxial Optoelectronic Devices Laser Welding System Errors Analysis And Welding Process Research

Optoelectronic devices support the development of optical fiber communication technology, their cost mostly lie in the packaging process, the package costs about70%to90%of the total cost. At present, the industrialization of optoelectronic devices is still backward in our country, packaging technologies and equipments mostly depend on imports. Laser welding has been widely used in optoelectronic device packaging, the selection of laser welding parameters plays an important role on improving welding quality, increasing welding strength and reducing residual stress. This research is focused on how to implement automation package and improve welding quality, the main contents are as follow:(1) Based on the structure and packaging technology of SC TOSA component, the coaxial optoelectronic devices laser welding equipment design ideas were proposed, the coupling alignment and welding platforms for laser diode and single mode fiber were built, laser welding equipment and control systems for coaxial optoelectronic devices were designed. The manufacturing result showed that:This equipment was relatively simple, reasonable, easy to control, miniature, successfully achieved automation package.(2) Non-strictly orthogonal properties between different platforms in the alignment of laser diode and single mode fiber, the optical channels were coupled interfered in the dimensional position adjustments, and the alignment platforms are also affected by many errors, which increase the difficulties of alignment. Based on the multi-body system theory and combined with homogeneous coordinate transformation, the motion error models of alignment system were established, and error sensitivity analysis were did, the theoretical basis and technical guidance were offered for the compensation of motion errors, the improvements for machining accuracy and assembly accuracy of platforms. The results showed that:the motion precision of platforms have an important effect on motion errors, and must be strictly controlled, the influence extent of axis orientation errors were smaller than the former, but them could cause errors in the other error sensitive direction of coupling alignment, and should be properly controlled.(3) Based on the finite element method, a laser welding finite element mode on SC TOSA component was established, a transient thermal analysis was did, and influence rules of laser welding parameters on the welding quality were obtained, based on the orthogonal test, the influence extent of various parameters on the welding quality were received, laser welding tests were did, the weld break tension on various parameters were obtained, the theoretical basis and technical guidance were offered for the selection of laser welding parameters, the molten pool characteristics of the welding spot section were analyzed, and were compared with the finite element results, the accuracy of the laser welding finite element model was verified. The results showed that: the peak power has the maximum influence extent on the molten pool size and shape, followed by the pulse width, defocusing distance is least; with the peak power, pulse width and number of solder joints increase, the weld break tension increase, while with the defocusing distance increase, it decreases, we could evaluate the weld break tension by the ratio of the weld pool depth to width and depth to length.