Method and device for inserting separating cracks into a substrate using a fixed blade with a fixed opening

Device for introducing separating cracks in a substrate, comprises: a workpiece holder (1) for receiving the substrate; a laser source (3) for emitting a laser beam (31); a laser head (32) with an optic (33); an optical axis; a moving device for moving the laser head in a direction of movement along the separating crack with a crack initiation and crack end; and a standing screening device with an aperture, perpendicular to the optical axis. The aperture opening of the aperture is variable in its position and/or in its size, to shade the laser beam over the beam spot length. Device for introducing separating cracks in a substrate, under the influence of a laser beam with an elliptical beam cross-section, comprises: a workpiece holder (1) for receiving the substrate; a laser source (3) for emitting a laser beam (31); a laser head (32) with an optic (33), downstream to the laser source, in a beam exit direction; an optical axis, where the optical axis and the laser beam is directed perpendicularly on the surface of the recorded substrate, and the optic is adapted to control the laser beam to mold such that it has an elliptical beam cross-section and forms an elliptical beam spot with a beam spot length and beam spot width on the surface of the substrate; a moving device for moving the laser head in a direction of movement along the separating crack with a crack initiation and crack end, introduced in the recorded substrate; and a standing screening device with an aperture, associated with the laser head, perpendicular to the optical axis, and is arranged between the optic and the workpiece holder in an aperture plane. The aperture opening of the aperture is variable in its position and/or in its size, along the direction of movement, to shade the laser beam over the beam spot length in a continuously decreasing or increasing manner. The exposure of the substrate with the laser beam is avoided before the crack initiation and beyond the crack end. An independent claim is also included for introducing the separating cracks in the substrate, comprising: receiving and positioning the substrate in the workpiece holder; generating the laser beam with the elliptical beam cross-section to form the elliptical beam spot with the beam spot length and the beam spot width on the surface of the recorded substrate; and directing the laser beam on the recorded substrate. The beam spot length is aligned in the direction comprising the introduced separation crack, the crack in