Laser cutting of display glass compositions

Patent metadata

Field	Value
Publication number	US-9850160-B2
Application number	US-201414529520-A
Country	US
Kind code	B2
Filing date	Oct 31, 2014
Priority date	Dec 17, 2013
Publication date	Dec 26, 2017
Grant date	Dec 26, 2017

Abstract

The present invention relates to a laser cutting technology for cutting and separating thin substrates of transparent materials, for example to cutting of display glass compositions mainly used for production of Thin Film Transistors (TFT) devices. The described laser process can be used to make straight cuts, for example at a speed of >1 m/sec, to cut sharp radii outer corners (<1 mm), and to create arbitrary curved shapes including forming interior holes and slots. A method of laser processing an alkaline earth boro-aluminosilicate glass composite workpiece includes focusing a pulsed laser beam into a focal line. The focal line is directed into the glass composite workpiece, generating induced absorption within the material. The workpiece and the laser beam are translated relative to each other to form a plurality of defect lines along a contour, with adjacent defect lines have a spacing of 0.1-20 microns.

First claim

What is claimed is:

1. A method of laser processing an alkaline earth boro-aluminosilicate glass composite workpiece, the method comprising:
focusing a pulsed laser beam provided by a pulsed laser into a laser beam focal line oriented along the beam propagation direction and is directed into the alkaline earth boro-aluminosilicate glass composite workpiece, the laser beam focal line generating an induced absorption within the material of the alkaline earth boro-aluminosilicate glass composite workpiece, and the induced absorption producing a defect line along the laser beam focal line within the alkaline earth boro-aluminosilicate glass composite workpiece; and
translating the alkaline earth boro-aluminosilicate glass composite workpiece and the laser beam relative to each other along a contour, thereby laser forming a plurality of defect lines along the contour within the alkaline earth boro-aluminosilicate glass composite workpiece, wherein a periodicity between adjacent defect lines is between 0.1 micron and 20 microns, wherein the alkaline earth boro-aluminosilicate glass composite workpiece is in the form of a glass sheet, and wherein focusing the pulsed laser beam and translating the workpiece and the laser beam relative to each other along the contour are performed with the glass sheet at an online draw, wherein the glass sheet comprises at least two layers having at least two different respective annealing temperatures, and wherein focusing and translating are performed with the glass sheet at a temperature between the at least two different respective annealing temperatures.

2. The method of claim 1 , wherein the pulsed laser has laser power of 10 W-150 W.

3. The method of claim 2 , wherein the pulsed laser has laser power of 10 W-100 W and produces pulse bursts with 2-25 pulses per pulse burst.

4. The method of claim 2 , wherein the pulsed laser has laser power of 25 W-60 W, and produces pulse bursts with at least 2-25 pulses per burst and the periodicity between the defect lines is 2-10 microns.

5. The method of claim 4 , wherein the periodicity is between 0.5 micron and 3 microns.

6. The method of claim 2 , wherein the pulsed laser has laser power of 10 W-100 W and the alkaline earth boro-aluminosilicate glass composite workpiece or the laser beam is translated relative to one another at a rate of at least 0.25 m/sec.

7. The method of claim 2 , wherein (i) the pulsed laser has laser power of 10 W-100 W; and (ii) the alkaline earth boro-aluminosilicate glass composite workpiece or the laser beam is translated relative to one another at a rate of at least 0.4 m/sec.

8. The method of claim 1 , wherein the periodicity is between 0.5 micron and 3 microns.

9. The method of claim 1 , wherein the periodicity is between 2 micron and 20 microns.

10. The method of claim 1 , further comprising separating the alkaline earth boro-aluminosilicate glass composite workpiece along the contour.

11. The method of claim 10 , wherein separating the alkaline earth boro-aluminosilicate glass composite workpiece along the contour includes applying a mechanical force to facilitate separation along the contour.

12. The method of claim 10 , wherein separating the alkaline earth boro-aluminosilicate glass composite workpiece along the contour includes directing a carbon dioxide (CO2) laser beam into the alkaline earth boro-aluminosilicate glass composite workpiece along or near the contour to facilitate thermal stress induced separation of the alkaline earth boro-aluminosilicate glass composite workpiece along the contour.

13. The method of claim 1 , wherein a pulse duration is in a range of between greater than about 1 picosecond and less than about 100 picoseconds.

14. The method of claim 13 , wherein the pulse duration is in a range of between greater than about 5 picoseconds and less than about 20 picoseconds.

15. The method of claim 1 , wherein a burst repetition rate of the pulsed laser beam is in a range of between about 1 kHz and about 4 MHz.

16. The method of claim 15 , wherein the burst repetition rate is in a range of between about 10 kHz and about 650 kHz.

17. The method of claim 1 , wherein each pulse of the pulsed laser beam has an average laser burst energy measured at the alkaline earth boro-aluminosilicate glass composite workpiece greater than 40 microJoules per mm thickness of alkaline earth boro-aluminosilicate glass composite workpiece.

18. The method of claim 1 , wherein pulses of the pulsed laser beam are produced in bursts of at least two pulses separated by a duration in a range of between about 1 nsec and about 50 nsec, and wherein burst repetition rate of the pulsed laser beam is in a range of between about 1 kHz and about 650 kHz.

19. The method of claim 18 , wherein the pulses produced in bursts are separated by a duration of about 20 nsec.

20. The method of claim 1 , wherein the pulsed laser beam has a wavelength selected such that the alkaline earth boro-aluminosilicate glass composite workpiece is substantially transparent at this wavelength.

21. The method of claim 1 , wherein the laser beam focal line has a length in a range of between about 0.1 mm and about 10 mm.

22. The method of claim 1 , wherein the laser beam focal line has a length in a range of between about 0.1 mm and about 1 mm.

23. The method of claim 1 , wherein the laser beam focal line has an average spot diameter in a range of between about 0.1 micron and about 5 microns.

24. The method of claim 1 , wherein the induced absorption produces subsurface damage up to a depth less than or equal to about 100 microns within the alkaline earth boro-aluminosilicate glass composite workpiece.

25. The method of claim 1 , wherein laser forming the plurality of defect lines along the contour within the alkaline earth boro-aluminosilicate glass composite workpiece facilitates separating the alkaline earth boro-aluminosilicate glass composite workpiece along a surface defined by the contour to form a separated surface, and wherein the induced absorption produces an Ra surface roughness of the cut and separated edge of less than or equal to about 0.5 micron.

26. The method of claim 1 , wherein laser forming the plurality of defect lines along the contour within the alkaline earth boro-aluminosilicate glass composite workpiece facilitates separating the alkaline earth boro-aluminosilicate glass composite workpiece along a surface defined by the contour to form a separated surface, and wherein the induced absorption produces particles on the separated surface with an average diameter of less than 3 microns.

27. The method of claim 1 , wherein the alkaline earth boro-aluminosilicate glass composite workpiece has a thickness in a range of between about 0.01 mm and about 5 mm.

28. The method of claim 1 , wherein the alkaline earth boro-aluminosilicate glass composite workpiece and pulsed laser beam are translated relative to each other at a speed in a range of between about 1 mm/sec and about 3400 mm/sec.

29. The method of claim 1 , further comprising applying at least one of a heat source, a tensile stress, or a bending stress to the glass sheet in the region of the contour to facilitate separation of the glass sheet from the draw along the contour.

30. The method of claim 1 , wherein the contour is adjacent to a bead of the glass sheet, and wherein laser forming the plur

Assignees

• Corning Inc

Inventors

• Marjanovic Sasha
• Nieber Albert Roth
• Piech Garrett Andrew
• Schillinger Helmut
• Tsuda Sergio
• Wagner Robert Stephen

Classifications

• Y10T428/249921

  Web or sheet containing structurally defined element or component · CPC title

• B23K26/53

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

• C03B17/064

  by the overflow downdraw fusion process; Isopipes therefor · CPC title

• C03B33/0215

  the ribbon being in a substantially vertical plane · CPC title

• Y10T428/24777

  Edge feature · CPC title