Fiber Laser Welding of High Integrity Implantable Medical Devices

Medical implantable devices like pacemakers, ICDs and leads are progressively becoming more compact and lighter. Some of the components used for hermetic and structural welding are still large and thick enough for conventional Nd:YAG pulsed lasers. However, some of the welded components, particularly used for electrical connections, have become so small and thin that the conventional Nd:YAG laser performs like a big and rough tool. The greatest challenge for welding is that the miniature components have limited heat sink ability, particularly if the components contain heat sensitive elements, such as electronic chips, lower melting point plastics, and organic materials. Properly selected laser beam characteristics, such as diameter of the beam and energy distribution within the focused spot in welding area, may significantly improve welding process increasing yield during production. The results of this study have identified three fundamental criteria relating to the laser beam welding of the miniature components. First is a comparable diameter of the beam in welding area. Second is the consistency of energy output. Third is the minimization of the component heat input. The presentation discusses the analysis made on the application of the FiberStar® portable laser workstation, which incorporates the SPI High Power 1090 nm 100W air-cooled fiber laser engine, to production components such as super thin Pt, Cu-Ni, Cu and MP35N conductors, cables, electrodes and compact electronic subassemblies.