Precision laser scoring

Patent metadata

Field	Value
Publication number	US-9302346-B2
Application number	US-201013257059-A
Country	US
Kind code	B2
Filing date	Mar 19, 2010
Priority date	Mar 20, 2009
Publication date	Apr 5, 2016
Grant date	Apr 5, 2016

Abstract

Method and apparatus for laser scoring a sheet material. An elongated laser beam having S-mode intensity profile in the width direction and a flat-top-mode profile in the length direction is used to achieve high precision scoring. The invention can be used for scoring large-size glass substrates for LCD displays.

First claim

What is claimed is:

1. A process for splitting a sheet, comprising the following steps:
(I-1) providing a circular laser beam having a diameter D(CLB) and an energy distribution in S-mode along any diameter thereof;
(I-2) converting the circular laser beam into an elongated laser beam having a width W(LB) and a length L(LB) where intercepted by a surface of the sheet by passing the circular laser beam through an optical assembly adapted for maintaining the energy distribution in S-mode along the width, and transforming the energy distribution in S-mode to a flat-top-mode profile along the length;
(II) exposing part of the surface of the sheet along a scoreline to the laser beam and causing the temperature of the exposed area to rise, wherein the total exposed area has a width W(EA), a length L(EA), W(EA)≈W(LB), and the scoreline is within the exposed area and is essentially parallel to L(LB); and
(III) splitting the sheet substantially linearly along the scoreline,

wherein the laser beam is generated by a continuous wave CO 2 laser.

2. A process according to claim 1 , wherein step (II) comprises the following steps:
(II-1) translating the laser beam in a direction essentially parallel to L(LB) along a scoreline in the exposed area on the surface of the sheet.

3. A process according to claim 2 , wherein in step (II-1), the translation speed of the laser beam is at least 750 mm/s.

4. A process according to claim 1 , wherein in step (I), the laser beam provided has an aspect ratio of at least 30.

5. A process according to claim 1 , wherein in step (I), the laser beam provided has a width in the range of from 0.5 mm to 3 mm.

6. process according to claim 1 , wherein the sheet consists essentially of an inorganic glass material, glass-ceramic material or ceramic material.

7. A process according to claim 6 , wherein in step (III), the edge of the split glass sheets along the scoreline has a total waviness of not more than 50 μm.

8. A process according to claim 6 , wherein L(EA)≧2000 mm.

9. A process according to claim 1 , further comprising the following step (IIa) between step (II) and step (III):
(IIa) cooling at least part of the exposed area by a fluid immediately upon exposure.

10. A process according to claim 9 , further comprising the following step (IIb) between step (II) and step (III):
(IIb) bending the glass sheet along the scoreline.

11. A process according to claim 1 , wherein in step (I-2), the optical assembly is chosen such that W(LB)<D(CLB).

12. A process according to claim 1 , wherein in step (I-2), the optical assembly comprises a first lens operating to (a) elongate the dimension of the beam in the direction of L(LB) and (b) transform the energy distribution profile from S-mode to flat-top-mode in the direction of L(LB), and a second lens operating to decrease the dimension of the circular laser beam in the direction of W(LB).

13. A process according to claim 12 , wherein in step (I-2), the first lens is a diverging modified cylindrical lens, and the second lens is a focusing cylindrical lens.

14. A process according to claim 1 , wherein in step (I-2), the optical assembly comprises a single lens operating to (i) decrease the dimension of the circular laser beam in the direction of W(LB), and (ii) increase the dimension of and transform the energy distribution from S-mode to flat-top-mode the circular laser beam in the direction of L(LB).

Assignees

• Abramov Anatoli Anatolyevich
• Wu Qi
• Zhou Naiyue
• Corning Inc

Inventors

• Abramov Anatoli Anatolyevich
• Wu Qi
• Zhou Naiyue

Classifications

• B23K2203/50

  Operations & Transport · mapped topic

• B23K26/364

  for making a groove or trench, e.g. for scribing a break initiation groove · CPC title

• B23K26/361

  for deburring or mechanical trimming (B23K26/351 takes precedence) · CPC title

• B23K26/703

  Cooling arrangements (by using a fluid stream B23K26/14) · CPC title

• B23K26/0869

  Devices involving movement of the laser head in at least one axial direction · CPC title