Patent ID: 8212180

Claim:
A method for severing a brittle flat material, comprising heating said flat material along dividing lines below the fusing temperature by means of lasers, said dividing lines thereby having only length and width characteristics, subsequently shocking said material by a coolant jet so that a thermally-induced mechanical stress difference effects a material separation, wherein traces having length, width and depth characteristics, are previously produced in the flat material along the dividing lines so that the flat material has a smaller breaking stress along the traces than in the unprocessed material wherein said traces are produced by a material modification, whereby the material structure of the material is changed by the addition of a depth component to said dividing lines, said depth being less than one-tenth the thickness of said flat material, and no less than 3 μm, and the critical breaking stress is reduced along the traces, and wherein the separation with the laser takes place along said traces.