Method and apparatus for scoring thin glass and scored thin glass

Patent metadata

Field	Value
Publication number	US-9896372-B2
Application number	US-201514956153-A
Country	US
Kind code	B2
Filing date	Dec 1, 2015
Priority date	Dec 1, 2014
Publication date	Feb 20, 2018
Grant date	Feb 20, 2018

Abstract

A method and apparatus for scoring thin glass for the purpose of score and break separation as well as an accordingly prepared scored thin glass are provided. The scoring tool is pressed onto the thin glass and drawn along the scoring line with an adjusted scoring contact pressure force as a vertical scoring force component. This permits to production of prescored ultrathin glass of Knoop hardness from 350 to 650 with a score depth from 1/20 to ⅘ of the material thickness.

First claim

What is claimed is:

1. A method for scoring a sheet of thin glass along an intended score line for the purpose of score and break separation, comprising the steps of:
providing the sheet of thin glass on a worktable of a machine tool, the machine tool comprising a scoring tool, a drivable feed slide, and a parallel rocker, the parallel rocker comprising biasing leaf springs having first ends connected to the drivable feed slide and second ends connected to the scoring tool, the parallel rocker being deflected by displacement of the drivable feed slide along an axis that is perpendicular to the sheet of thin glass;
placing the scoring tool on the sheet of thin glass with a scoring force component along the axis;
drawing the scoring tool on the sheet of thin glass along the intended score line;
measuring, while drawing the scoring tool, the scoring force component by an extent of deflection of the parallel rocker; and
adjusting the scoring force component, while drawing the scoring tool, based on the measured scoring force component.

2. A method for scoring thin glass along an intended score line for the purpose of score and break separation, comprising the steps of:
providing a sheet of thin glass on a worktable of a machine tool that includes a scoring drive mechanism which is equipped with a driveable feed slide, a parallel rocker fixed to the driveable feed slide and a scoring tool mounted in a tool housing, the tool housing being secured to the parallel rocker;
approaching the scoring tool to the sheet of thin glass and vertically placing the scoring tool on the sheet of thin glass;
biasing leaf springs that are arranged in form of a parallelogram forming the parallel rocker and that have leaf spring ends clamped at a first component of the drivable feed slide on one end, and on the other end at a second component to which the tool housing of the scoring tool is secured, wherein upon deflection of the parallel rocker by parallel displacement of the drivable feed slide relative to an axis of the scoring tool, a vertical scoring force component perpendicular to the sheet of thin glass is adjustable without interference by any frictional force component;
drawing the scoring tool on the sheet of thin glass along the intended score line with an adjusted vertical scoring force component, and
measuring, while drawing the scoring tool, a vertical scoring force component by an extent of deflection of the parallel rocker.

3. The method as claimed in claim 2 , wherein the machine tool comprises a control loop including a target value memory for the feed slide, from which target values of the vertical scoring force component along the intended score line are taken and compared to measured actual values of the vertical scoring force component, in a comparison circuit, to obtain a respective control signal in case of a deviation, to drive the feed slide so as to offset the deviation.

4. The method as claimed in claim 2 , wherein the scoring is effected by applying a uniform force of 2 N and less.

5. The method as claimed in claim 2 , wherein the scoring is effected by applying a uniform force of less than 0.5 N.

6. The method as claimed in claim 2 , wherein the scoring is effected with a constant scoring force with a uniformity in a range of ±0.05 N.

7. The method as claimed in claim 2 , wherein the scoring is effected under a controlled atmosphere.

8. The method as claimed in claim 2 , wherein the scoring is effected in an environment specifically conditioned by a fluid phase.

9. The method as claimed in claim 8 , wherein the fluid phase comprises a fluid selected from the group consisting of alcohols, absolute alcohols, and absolute ethanol.

10. The method as claimed in claim 8 , wherein the scoring tool is at least partially enclosed by the fluid phase.

11. The method as claimed in claim 8 , wherein the scoring tool is completely enclosed by the fluid phase.

12. The method as claimed in claim 2 , wherein the step of providing the sheet of thin glass comprises providing the sheet of thin glass with a material thickness in a range between 350 μm and 3 μm.

13. The method as claimed in claim 2 , wherein the step of providing the sheet of thin glass comprises providing the sheet of thin glass with a Knoop hardness in a range from 350 to 650.

14. The method as claimed in claim 2 , wherein the step of providing the sheet of thin glass comprises providing the sheet of thin glass with a glass composition of:

Composition
(wt %)

SiO 2
57-66;

Al 2 O 3
18-23;

Li 2 O
 3-5;

Na 2 O + K 2 O
 3-25;

MgO + CaO + SrO + BaO
 1-4;

ZnO
 0-4;

TiO 2
 0-4;

ZrO 2
 0-5;

TiO 2 + ZrO 2 + SnO 2
 2-6;

P 2 O 5
 0-7;

F
 0-1; and

B 2 O 3
 0-2.

15. The method as claimed in claim 2 , wherein the step of providing the sheet of thin glass comprises providing the sheet of thin glass with a glass composition of:

Composition
(wt %)

SiO 2
 57-63;

Al 2 O 3
 18-22;

Li 2 O
3.5-5;

Na 2 O + K 2 O
  5-20;

MgO + CaO + SrO + BaO
  0-5;

ZnO
  0-3;

TiO 2
  0-3;

ZrO 2
  0-5;

Assignees

• Schott Ag

Inventors

• Vogt Juergen
• Jotz Matthias

Classifications

• C03C3/097

  containing phosphorus, niobium or tantalum · CPC title

• C03B33/105

  Details of cutting or scoring means, e.g. tips · CPC title

• C03C3/091

  containing aluminium · CPC title

• C03B33/027 Primary

  Scoring tool holders; Driving mechanisms therefor · CPC title

• C03B33/033

  Apparatus for opening score lines in glass sheets · CPC title