Method for severing brittle materials by lasers with asymmetric radiation density distribution
AssigneeJENOPTIK Automatisierungstechnik GmbH
InventorsGabriele Eberhardt, Hans-Ulrich Zuehlke, Uwe Weinzierl, Vladimir Kondratenko
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Abstract
In accordance with the method of the invention, flat workpieces of brittle material, e.g., sapphire, glass ceramic, or glass, can be severed by inducing thermomechanical stresses, particularly along severing lines of the same direction, with a laser beam having a beam spot with asymmetric radiation density distribution on the workpiece by a relative movement in different directions in that a mirror-symmetric change in radiation density is brought about exclusively by changing the method parameters.
Claims5
A method for severing a flat workpiece of brittle material by inducing thermomechanical stresses along severing lines by use of lasers, comprising the following steps:
- adjusting a predetermined output E1 at a first laser and adjusting an output E2 differing from E1 at a second laser, each laser generating a laser beam bundle;
- directing the two laser beam bundles to the surface of the workpiece to be severed, where each of them has an elliptic beam spot geometry which is determined in each instance by a major semiaxis and a minor semiaxis so that their major semiaxes both lie on a severing line so as to partially overlap, so that the two beam spots of the two laser beam bundles form a common elliptic beam spot whose radiation density distribution is asymmetric to its minor semiaxis;
- moving the laser beam bundles relative to the workpiece in the direction determined by the severing line;
- and
- directing a coolant flow to the workpiece behind the laser beam spot with respect to the movement direction.
Dependencies are inferred from the claim text.