Water Jet Guided Laser Cutting: a Powerful Hybrid Technology for Fine Cutting and Grooving

Material laser cutting is well known and widely used in industrial processes, including micro fabrication. An increasing number of applications require nevertheless a superior machining quality than can be achieved using classical laser cutting. An efficient possibility to increase the cut quality is to opt for the water-jet guided laser technology. In this technique the laser is conducted to the work piece by total internal reflection in a thin stable water-jet, comparable to the core of an optical fiber. The water jet guided laser technique was developed originally in order to reduce the heat affected zone near the cut, but in fact many other advantages were observed due to the use of a water-jet rather than an assist gas stream applied in classical laser cutting. In brief, the advantages are threefold: absence of divergence due to light guiding, efficient melt expulsion, and extremely efficient work piece cooling. This paper gives an overview of industrial applications of the water-jet guided laser technique. These applications range from the cutting of CBN or ferrite cores to the dicing of thin wafers and the manufacturing of stencils; each illustrates the significant impact of using the water-jet.