US 12,311,469 B2
Methods and devices for introducing separation lines into transparent brittle fracturing materials
Andreas Ortner, Gau-Algesheim (DE); Clemens Kunisch, Arnsheim (DE); Frank-Thomas Lentes, Bingen (DE); Jens Ulrich Thomas, Mainz (DE); Kurt Nattermann, Ockenheim (DE); and Michael Kluge, Offenbach am Main (DE)
Assigned to SCHOTT AG, Mainz (DE)
Filed by SCHOTT AG, Mainz (DE)
Filed on Aug. 17, 2020, as Appl. No. 16/994,724.
Application 16/994,724 is a continuation of application No. PCT/EP2019/053344, filed on Feb. 11, 2019.
Claims priority of application No. 10 2018 103 456.3 (DE), filed on Feb. 15, 2018; and application No. 10 2018 126 381.3 (DE), filed on Oct. 23, 2018.
Prior Publication US 2020/0376603 A1, Dec. 3, 2020
Int. Cl. B23K 26/359 (2014.01); B23K 26/06 (2014.01); B23K 26/0622 (2014.01); B23K 26/067 (2006.01); B23K 103/00 (2006.01)
CPC B23K 26/359 (2015.10) [B23K 26/0622 (2015.10); B23K 26/067 (2013.01); B23K 26/0648 (2013.01); B23K 2103/52 (2018.08); B23K 2103/54 (2018.08)] 6 Claims
OG exemplary drawing
 
1. A method for preparing a workpiece for separation, comprising:
providing a workpiece that is transparent for light of a pulsed laser beam and having a surface;
splitting the pulsed laser beam into two partial beams having separate paths using an optical system comprising at least one truncated axicon selected from the group consisting of plano-convex axicon, convex-concave axicon, biconvex axicon, concentric ring grating, and any combination thereof, wherein the pulsed laser beam is split by the truncated axicon, wherein the two partial beams comprise a first partial beam having a ring shape with a first diameter and a second partial beam being a central beam with a second diameter propagating centrally along the optical axis, and wherein the paths of the two partial beams are separate and distinct from one another;
directing the two separate partial beams onto the surface of the workpiece incident at different angles to a normal of the surface so that the focal points of the two separate partial beams are superimposed on one another inside the workpiece so that the partial beams intersect and form a linear sequence of intensity maxima separated by intensity minima, wherein the intensity of the minima is close to zero in the interior of the workpiece in the z direction, and wherein the z-direction extends 90° away from the surface, the sequence of intensity maxima being lined up one after another along an overlapping area of the two partial beams, the intensity maxima modifying a material of the workpiece so that a chain-like periodic pattern of material modifications is formed by the intensity maxima lined up one after another; and
moving the workpiece and the two partial beams relative to one another so that the sequence of intensity maxima form the chain-like periodic pattern into a separation line.