Optimized welding of conductive metals using pulse shaping and closed-loop control Available to Purchase

Low-power Nd:YAG lasers have been widely used for welding applications in batteries, small electrical components, and medical devices. In most cases, the welds are made in conduction mode. Some of the commonly used materials such as copper, aluminum, nickel, and platinum are highly reflective and are difficult to weld. One method to improve the absorption or reduce the reflection during welding is to use high peak energy. However, use of the high peak energy pulses leads to overheating; excess heat could be detrimental to the adjacent components, such as in medical devices and electronic enclosures. An alternative is to use shaped YAG pulses to improve energy coupling into the materials while simultaneously reducing the total energy input to the weld. In this paper, we report the results of laser-material interaction studies on commonly used reflective alloys such as copper and aluminum. Infrared (IR) sensors were used to identify specific phenomenon such as nugget initiation, size, melting, and splatter. The laser profile was manually tuned to enhance coupling. The combination of IR sensors and pulse shaping has the potential to significantly improve the weld quality of conductive metals.