Verfahren zum Trennen flacher Werkstücke aus Keramik mit einer berechneten Strahlflecklänge

摘要

The invention is directed to a method for splitting a flat ceramic workpiece through provocation of a separation crack due to stresses occurring as a result of temporal and local application of heat by means of laser along a desired splitting line and, following this, a temporal and local removal of heat by means of a coolant, wherein the beam spot length is calculated from the following formula l=8xdx24/WLF, where l is the length of the beam spot, WLF is the thermal conductivity of the ceramic to be split, and d is the thickness of the ceramic to be split, so that the length of the beam spot generated on the workpiece by the laser is selected depending upon the thermal conductivity of the ceramic and upon the thickness of the workpiece. Particularly with workpieces with high internal stress, process parameters such as the laser power or the forward feed speed are changed over the course of the process in order to influence the magnitude of the induced thermal stresses.