Patent ID: 8584490

Claim:
A process for cutting a sheet of brittle material having a thickness of at most 400 μm defined by a first major surface and a second major surface opposing the first major surface, comprising the following steps: (I) providing the sheet having a temperature T 1 ; (II) providing an electromagnetic wave beam having a wavelength absorptive by the brittle material; (III) projecting the electromagnetic wave beam onto the first major surface to have a footprint on the first major surface at a given time; (IV) providing an initiation defect on the first surface and/or the second surface; (V) scanning the electromagnetic wave beam along a predetermined path on the first major surface to heat the brittle material along the path to a temperature T 2 without using a cooling jet trailing the electromagnetic wave beam, said predetermined path having a distance from the initiation defect in the range of from 10 μm to 5 mm; and (VI) allowing the initiation defect to propagate into the path and extend along the path such that a portion of the brittle material sheet separates from the remainder of the sheet into a separated sheet with an edge defined by the predetermined path and wherein the initiation defect as formed during step (IV) does not extend along a length of the predetermined path that forms a corresponding length of the edge of the separated sheet.