Micro joining of dissimilar metals with a pulsed Nd: YAG laser

Majority of applications in electronics and medical devices industry requires micro joining of dissimilar materials. In principle, a laser can weld any material, which can be joined by conventional processes. In the welding of dissimilar metals, good solid solubility is essential for sound weld properties. The trends of joining dissimilar metals and miniaturisation of components are offering high challenges for welding methods. The weldability of dissimilar metals depends on many different factors. The physical properties have a high influence on the amount of energy coupled in and the heat transfer. The pulsed laser beam welding process is controlled by a variety of parameters. These include average power, peak power, power density, pulse width, pulse frequency and temporal pulse shape. This paper presents micro joining results achieved with a low average power pulsed laser for a range of materials used in electronic and medical industry.