Laser source independent basic parameters in micro-cutting

During the last four decades laser beam machining has been used as a powerful tool in rapid prototyping. Nd:YAG lasers are most widely used in machining of engineering materials, especially silicon for Micro-Electro-Mechanical-Systems (MEMS). Apart from laser micro-welding or laser micro-drilling, laser micro-cutting is one of the most important processes in rapid prototyping. In recent years the researchers have focused on the parameters of the laser beam, such as the pulse duration, the wavelength, the laser power, and the repetition rate. All these parameters depend on the laser system and can be varied in a wide range. The basic parameters - the focus position, the pulse overlap, the track overlap, the number of tracks, and the influence of wobbling - were mostly neglected, although their effect on laser micro-cutting is essential and independent of the above mentioned parameters of the laser system. This research work investigated laser micro-cutting holes in silicon wafers with a nanosecond Nd:YAG UV laser and determines for each parameter the number of scans, the required manufacturing time, the diameter on the laser beam output side as well as on the input side, and the corresponding flank angle.