Laser butt welding of copper and gold wire

A method was developed for butt welding .010″ diameter gold wire to 32 gauge stranded copper with teflon insulations. The copper is silverplated. Both soldering and welding were considered. A brief investigation of appropriate solder alloys and fluxes left doubts as to the suitability of this technique. Even with precise control, solder joints of this type are often subject to degradation at elevated storage or use temperature. Several welding techniques were considered, among which were percussive welding, plasma arc welding, and laser welding. Initial feasibility experiments indicated that while each of these welding techniques showed promise, laser welding results were so outstanding that the balance of the study concentrated on laser welding exclusively.