Method and device for laser-assisted separation of a portion from a sheet glass element

Patent metadata

Field	Value
Publication number	US-2023141696-A1
Application number	US-202318150122-A
Country	US
Kind code	A1
Filing date	Jan 4, 2023
Priority date	Jul 15, 2015
Publication date	May 11, 2023
Grant date	—

Abstract

A method for separating a portion from a sheet glass element having a thickness of at least 2 millimeters along an intended separation line that divides the sheet glass element into the portion and a remaining main part is provided. The method includes producing filamentary damages comprising sub-micrometer hollow channels in a volume of the glass sheet element adjacently aligned along the separation line; and heating and/or cooling the glass sheet element to cause expansion and/or contraction so that the portion detaches from the main part along the separation line. The portion and the remaining main part each remain intact as a whole. The step of producing the filamentary damages includes generating a plasma within the volume with laser pulses of an ultrashort pulse laser; and displacing points of incidence of the laser pulses over a surface of the glass sheet element along the separation line.

First claim

What is claimed is:

1 . A method for separating a portion from a sheet glass element along an intended separation line that divides the sheet glass element into the portion and a remaining main part, the method comprising:
producing filamentary damages comprising sub-micrometer hollow channels in a volume of the glass sheet element adjacently aligned along the separation line; and heating and/or cooling the glass sheet element to cause expansion and/or contraction so that the portion detaches from the main part along the separation line, wherein the portion and the remaining main part each remain intact as a whole, wherein the step of producing the filamentary damages comprises:
generating a plasma within the volume with laser pulses of an ultrashort pulse laser, wherein the sheet glass element comprises a material that is transparent to the laser pulses, and
displacing points of incidence of the laser pulses over a surface of the glass sheet element along the separation line.

2 . A method for separating a portion from a sheet glass element, the method comprising:
producing filamentary damages in a volume of the glass sheet element adjacently aligned along a non-rectilinear separation line, the non-rectilinear separation line dividing the sheet glass element into the portion and a remaining main part; causing thermal expansion and/or contraction so that the portion and the remaining main part change size differently from each other to produce local tensile stresses sufficient such that the portion detaches from the main part along the non-rectilinear separation line, wherein the portion and the remaining main part each remain intact as a whole; and coordinating an adjustment of L, ΔT, and α such that a minimal gap width (S) between the portion and the remaining main part is greater than a mean roughness (R), wherein L is a minimum extension of the portion in a plane of the glass sheet element, ΔT is a temperature difference in Kelvin between an average temperature of the remaining main part and an average temperature of the portion during the heating and/or cooling step, α is a coefficient of thermal expansion of the material of the glass sheet element, and R is an average roughness of an edge surface of the portion along which the portion separates from the remaining main part, wherein the step of producing the filamentary damages comprises:
generating a plasma within the volume with laser pulses of an ultrashort pulse laser, wherein the sheet glass element comprises a material that is transparent to the laser pulses, and
displacing points of incidence of the laser pulses over a surface of the glass sheet element along the non-rectilinear separation line.

Assignees

• Schott Ag

Inventors

• Wagner Fabian
• Ortner Andreas
• Seidl Albrecht
• Lentes Frank-Thomas
• Gerban Jörn
• Schmitt Simon

Classifications

• C03B33/04

  Cutting or splitting in curves, especially for making spectacle lenses · CPC title

• C03B33/0222 Primary

  Scoring using a focussed radiation beam, e.g. laser · CPC title

• C03B33/091 Primary

  using at least one focussed radiation beam, e.g. laser beam (C03B33/0955 takes precedence) · CPC title

• B23K2103/54

  Glass · CPC title

• B23K26/53

  for modifying or reforming the material inside the workpiece, e.g. for producing break initiation cracks · CPC title