Abstract In this thesis, we have studied the post-weld-shift (PWS) in laser welding technique for laser module packaging. The joining method for packaging of laser module by laser welding technique can offer a number of significant advantages. It provides strong joint strength, therefore, the packaging has good long-term stability. It also provides high-speed and high-volume production, and hence the packaging is potential low cost. However, the laser welding process has caused PWS of laser module, would decay the coupling efficiency of laser module. We investigate the weld-spot by using metallographic method. The PWS in stainless steel (SS304L) plate is studied experimentally and numerically. The metallographic results are in good agreement with the Finite-Element-Method (FEM) results that the PWS in x-y plane can be neglected. Based on the experimentally and numerically results of PWS in SS304L, we investigate the yield improvement of laser module packaging. The laser hammer technique was used to improve the coupling efficiency of laser module. The results show displacement of the z-axis is from 1 to 9 (£gm) that equals to the angle changes of upper parts of laser module from 0.38¡Ñ10-2 to 3.4¡Ñ10-2 (degree). Therefore, the coupling efficiency of laser module can be improved from 4 to 20 (%).

The fiber clips is a device for holding an optical fiber which is enclosed in the ferrule, adjustment it to the optimum aligning position with respect to the laser diode and fixing it on the substrate of the butterfly-type laser module by the laser welding. It is hard for the extant saddle shaped clips to be manufactured and the result causes the unable mass production and the high cost. Otherwise, the packaging process has caused PWS of laser module, would decay the coupling efficiency of laser module. Aim at the shortcomings, the purpose of this study proceeds to the creative design of the fiber clips with the systematic engineering design and make a set of the manufacturing method by the pressing die to cause automatic mass production in the future. First, identify the basic characteristics based on an analysis of the patents and then get the conditions and trend. Second, find the function needs and elaborate the specification of design. Third, the use of morphological analysis method and design process is formulated to synthesize and evaluate the improving structure. Finally, taking the design cases will develop the embodiment design and prove the propose approach for the design process. Otherwise, it develops an improvement technique and adjustment method for PWS and wishes can reduce or improve the effects of it.