Method of changing the surface of a glass substrate containing silver, by using a laser beam

• US 6,220,058 B1
• Filed: 09/22/1998
• Issued: 04/24/2001
• Est. Priority Date: 03/25/1996
• Status: Expired due to Fees

• Current Assignee: Nippon Sheet Glass Company Limited
• Original Assignee: Nippon Sheet Glass Company Limited
• Inventors: Hamanaka, Kenjiro, Koyama, Tadashi, Tsunetomo, Keiji, Oikawa, Masahiro
• Primary Examiner(s): HOFFMANN, JOHN M
• Application Number:
  US09/155,125
• Time in Patent Office: 945 Days
• Field of Search: 653/92, 653/86, 654/00, 65/301.3, 651/02, 651/06
• US Class Current: 65/392
• CPC Class Codes: B23K 26/032 using optical means
• CPC Class Codes: B23K 26/06 Shaping the laser beam, e.g. by masks or multi-focusing
• CPC Class Codes: B23K 26/064 by means of optical elements, e.g. lenses, mirrors or prisms
• CPC Class Codes: B23K 26/0648 comprising lenses
• CPC Class Codes: B23K 26/066 by using masks
• CPC Class Codes: B23K 26/0665 by beam condensation on the workpiece, e.g. for focusing
• CPC Class Codes: B23K 26/18 using absorbing layers on the workpiece, e.g. for marking or protecting purposes
• CPC Class Codes: B23K 26/389 of fluid openings, e.g. nozzles, jets laser machining of inkjet nozzles B41J2/1634
• CPC Class Codes: C03B 2201/58 doped with metals in non-oxide form, e.g. CdSe
• CPC Class Codes: C03B 23/006 by fusing, e.g. for flame sealing C03B9/42, C03B21/06, C03B23/02, C03B23/04, C03B23/18, C03B33/08 take precedence
• CPC Class Codes: C03B 23/02 Re-forming glass sheets
• CPC Class Codes: C03B 29/00 Reheating glass products for softening or fusing their surfaces; Fire-polishing; Fusing of margins
• CPC Class Codes: C03B 29/025 Glass sheets
• CPC Class Codes: C03C 23/0025 by a laser beam
• CPC Class Codes: G02B 3/0012 characterised by the manufacturing method
• CPC Class Codes: G02B 3/0056 arranged along two different directions in a plane, e.g. honeycomb arrangement of lenses G02B3/0043 takes precedence; miniaturised objectives for electronic devices employing wafer level optics G02B13/0085
• CPC Class Codes: G02B 6/32 having lens focusing means positioned between opposed fibre ends with lens being an integral part of the single fibre end G02B6/262
• CPC Class Codes: G02B 6/3644 the coupling means being through-holes or wall apertures
• CPC Class Codes: G02B 6/3664 2D cross sectional arrangements of the fibres
• CPC Class Codes: Y02P 40/57 Improving the yield, e-g- reduction of reject rates

Abstract

A laser processing method for removing glass by melting, evaporation or ablation from sheet-like glass substrate for forming microscopic concavities and convexities. Diffraction grating and planar microlens array obtained thereby.

Claims

1. A laser processing method for a glass substrate, comprising radiating the laser beam on the glass substrate, absorbing energy of the laser beam into the glass substrate, and altering a surface of the glass by melting, evaporation or ablation due to the energy, wherein microscopic concavities and convexities are formed on a surface of the glass substrate, by varying the spacial distribution of the intensity of the laser beam applied upon the surface of the glass substrate, thereby removing a greater amount of glass where the intensity is stronger, and less where the intensity is weaker, and wherein said glass substrate contains silver in the form of Ag atoms, Ag colloid or Ag ions to a predetermined depth with a concentration slope of the silver showing the highest concentration at the side surface to be processed and gradually decreasing to the predetermined depth.

2. A laser processing method for a glass substrate as defined in claim 1, wherein said laser beam comprises a laser beam having a periodical distribution in the intensity thereof to provide periodical concavities and convexities on said surface of the glass substrate.

3. A laser processing method for a glass substrate as defined in claim 2, wherein said laser beam having a periodical distribution in intensity is obtained by means of a phase mask.

4. A laser processing method for a glass substrate as defined in claim 2, wherein said laser beam having a periodical distribution in intensity is obtained by interference between two laser beams.

5. A laser processing method for a glass substrate as defined in claim 2, wherein the cross-sectional configuration of the periodical concavities and convexities is controlled by varying the pulse energy of the laser beam.

6. A laser processing method for a glass substrate, comprising radiating the laser beam on the glass substrate, absorbing energy of the laser beam into the glass substrate, and altering a surface of the glass by melting, evaporation or ablation due to the energy, wherein microscopic concavities and convexities are formed on a surface of the glass substrate, by varying the spacial distribution of the intensity of the laser beam applied upon the surface of the glass substrate, thereby removing a greater amount of glass where the intensity is stronger, and less where the intensity is weaker, and wherein said glass substrate contains silver in the form of Ag atoms, Ag colloid or Ag ions throughout the glass substrate with a concentration slope of the silver showing the highest concentration at the side surface to be processed and gradually decreasing to the other side surface.

7. A laser processing method for a glass substrate as defined in claim 6, wherein said laser beam comprises a laser beam having a periodical distribution in the intensity thereof to provide periodical concavities and convexities on said surface of the glass substrate.

8. A laser processing method for a glass substrate as defined in claim 6, wherein the cross-sectional configuration of the periodical concavities and convexities is controlled by varying the pulse energy of the laser beam.