For high-speed laser modules in lightwave communication systems, the butterfly laser modules are widely used. When laser welding is applied to assemble a butterfly package, it is usually necessary to have mechanical elements such as substrates, fiber ferrule, and clips of house materials to facilitate fiber handing and retention within the package. One of the greatest challenges for packaging these optoelectronic components by employing laser welding is to pursue the reliable and accurate joint. However, during the welding process, rapid solidification of the welded region and the associated material shrinkage often cause a post-weld-shift (PWS) of fiber. The PWS can never be completely eliminated in the laser welding process, and significantly affects the package yield. The PWS induced fiber alignment shifts of fiber ferrule-clip (FFC) joints in high-speed butterfly laser packaging by laser welding technique has been studied experimentally. There are two types of clip design in the FFC joint: the type I design is without a gap between clip and fiber ferrule and type II is a 5