US 12,304,005 B2
Sacrificial layers to enable laser cutting of textured substrates
Garrett Andrew Piech, Corning, NY (US); and Sergio Tsuda, Horseheads, NY (US)
Assigned to CORNING INCORPORATED, Corning, NY (US)
Filed by CORNING INCORPORATED, Corning, NY (US)
Filed on Jan. 28, 2022, as Appl. No. 17/587,430.
Claims priority of provisional application 63/144,165, filed on Feb. 1, 2021.
Prior Publication US 2022/0241902 A1, Aug. 4, 2022
Int. Cl. B23K 26/40 (2014.01); B23K 26/04 (2014.01); B23K 103/00 (2006.01)
CPC B23K 26/40 (2013.01) [B23K 26/04 (2013.01); B23K 2103/54 (2018.08)] 17 Claims
OG exemplary drawing
 
1. A method of separating a transparent workpiece, the method comprising:
depositing a sacrificial layer onto a textured surface of the transparent workpiece, the transparent workpiece having a thickness between the textured surface and a second surface of the transparent workpiece, the sacrificial layer comprising a refractive index that is less than or equal to a refractive index of the transparent workpiece and greater than or equal to a refractive index of air, the textured surface having an Sa value of greater than or equal to 0.1 μm;
generating a defect-forming laser beam via an optical assembly;
forming a plurality of defects comprising an ablated region in the transparent workpiece by directing the defect-forming laser beam directly onto an impingement surface of the sacrificial layer from the optical assembly such that the laser beam propagates through the transparent workpiece via the sacrificial layer and translating the transparent workpiece and the laser beam relative to each other along a contour, wherein the defect forming laser beam comprises:
a pulsed laser beam forming a laser beam focal line at the textured surface or within the transparent workpiece, and
an optical power of greater than or equal to a critical power level to induce Kerr effect self-focusing throughout the entirety of the thickness; and
separating the transparent workpiece along the contour.