WIAD Minimization in Butterfly Laser Module Packages: Clip Design

Welding-induced alignment distortion (WIAD) is a serious issue in photonics packaging using laser welding, which may significantly affect the packaging yield. An elimination or minimization of the WIAD in butterfly laser module packaging is possible if process parameters or laser parameters are optimized. This work reports the attempt in WIAD reduction by design of the packaging weld clip. Seven types of weld clips were designed and implemented in the butterfly laser module packaging process. The WIADs with different weld clips were analyzed by means of numerical simulations by the finite-element method. It was concluded that the weld clip design affects the WIAD through the weld pattern distribution, and that the distortion can be controlled within a minimal range by proper design of the weld clip and the laser welding sequence.