Ultra-high-precision helical laser cutting of sapphire Available to Purchase

High-precision laser cutting of thin sapphire and glass between 0.3 mm and 1 mm thickness gains more importance in industrial applications every month. Besides process speed, quality aspects such as edge-geometry and parallel cutting-edges are highly demanded. During a helical process the laser beam is moved on a helical path with a certain helical diameter where the beam itself is rotated relatively to the helical path position around the beam axis itself. With this imaging process the hole and cutting-geometry is independent of the beam shape. The optical rotational-speed is double as high as the mechanical rotational-speed of the hollow shaft engine. This is realized by a rotating Dove-prism. In addition a balancing holder compensates the geometrical error. Three optical elements are installed within the balancing holder and ensure that the geometrical error is below 5µm. As a result perfect roundness of entrance and exit can be achieved during drilling processes. If the material is mounted on a moving two-axes system helical cutting can be performed. A high understanding of the combination between repetition rate, feed motion speed, pulse duration and laser output power is essential in order to obtain the advantages of a helical operation. The studies published in this papers contains process evaluation and parameter research such as gas pressure, nozzle work-piece-distance, laser parameters and feed motion speed. The experiments are performed using a Trumpf TruMicro 5270 laser source.