Sacrificial cover layers for laser drilling substrates and methods thereof

• US 9,758,876 B2
• Filed: 11/27/2013
• Issued: 09/12/2017
• Est. Priority Date: 11/29/2012
• Status: Expired due to Fees

• Current Assignee: Corning Incorporated
• Original Assignee: Corning Incorporated
• Inventors: Shorey, Aric Bruce, Piech, Garrett Andrew, Li, Xinghua, Thomas, John Christopher, Keech, John Tyler, Domey, Jeffrey John, Shustack, Paul John
• Primary Examiner(s): Duclair, Stephanie
• Application Number:
  US14/092,536
• Publication Number:
  US 20140147623A1
• Time in Patent Office: 1,385 Days
• Field of Search: None
• CPC Class Codes: B23K 2103/50 Inorganic material, e.g. metals, not provided for in B23K2103/02 – B23K2103/26
• CPC Class Codes: B23K 2103/54 Glass
• CPC Class Codes: B23K 26/0622 by shaping pulses
• CPC Class Codes: B23K 26/18 using absorbing layers on the workpiece, e.g. for marking or protecting purposes
• CPC Class Codes: B23K 26/386 of blind holes
• CPC Class Codes: B23K 26/389 of fluid openings, e.g. nozzles, jets laser machining of inkjet nozzles B41J2/1634
• CPC Class Codes: B23K 26/40 taking account of the properties of the material involved
• CPC Class Codes: C03B 33/0222 Scoring using a focussed radiation beam, e.g. laser
• CPC Class Codes: C03B 33/102 involving a focussed radiation beam, e.g. lasers
• CPC Class Codes: C23F 4/04 by physical dissolution
• CPC Class Codes: H05K 3/0026 by laser ablation
• CPC Class Codes: Y10T 428/24322 Composite web or sheet

Abstract

A method for forming a plurality of precision holes in a substrate by drilling, including affixing a sacrificial cover layer to a surface of the substrate, positioning a laser beam in a predetermined location relative to the substrate and corresponding to a desired location of one of the plurality of precision holes, forming a through hole in the sacrificial cover layer by repeatedly pulsing a laser beam at the predetermined location, and pulsing the laser beam into the through hole formed in the sacrificial cover layer. A work piece having precision holes including a substrate having the precision holes formed therein, wherein a longitudinal axis of each precision hole extends in a thickness direction of the substrate, and a sacrificial cover layer detachably affixed to a surface of the substrate, such that the sacrificial cover layer reduces irregularities of the precision holes.

Claims

1. A method for forming a plurality of precision holes in a glass substrate by drilling, the method comprising:

affixing a sacrificial cover layer to a surface of the glass substrate;

positioning a laser beam in a predetermined location relative to the glass substrate and corresponding to a desired location of one of the plurality of precision holes;

forming a through hole in the sacrificial cover layer by repeatedly pulsing the laser beam at the predetermined location; and

pulsing the laser beam into the through hole formed in the sacrificial cover layer at the predetermined location thereby creating the one of the plurality of precision holes, wherein a number of pulses applied to the glass substrate is determined by a desired depth of the one of the plurality of precision holes,

wherein the sacrificial cover layer comprises glass and has a different composition than the glass substrate.

2. The method of claim 1, wherein the sacrificial cover layer is removed after the plurality of precision holes is formed in the glass substrate.

3. The method of claim 1, further comprising etching the glass substrate with an etching solution.

4. The method of claim 1, further comprising applying an electrically conductive material to one or more precision holes of the plurality of precision holes.

5. The method of claim 1, further comprising applying a fluid to at least one of the sacrificial cover layer and the surface of the glass substrate before attaching the sacrificial cover layer to the surface of the glass substrate.

6. The method of claim 1, wherein the sacrificial cover layer is affixed to the surface of the glass substrate by applying a liquid polymer material to the surface of the glass substrate.

7. The method of claim 6, further comprising removing the sacrificial cover layer from the surface of the glass substrate by applying a solvent to the sacrificial cover layer.

8. The method of claim 1, wherein the sacrificial cover layer is affixed to the surface of the glass substrate by applying a polymer tape to the surface of the glass substrate.

9. The method of claim 1, wherein the sacrificial cover layer is affixed to the surface of the glass substrate by Van der Waals attraction.

10. The method of claim 9, wherein a bonding energy provided by the Van der Waals attraction is between about 30 mJ/m² to about 100 mJ/m².

11. The method of claim 9, further comprising removing the sacrificial cover layer from the surface of the glass substrate by heating the sacrificial cover layer and the glass substrate such that the sacrificial cover layer separates from the glass substrate.

12. The method of claim 1, further comprising, after affixing the sacrificial cover layer to the glass substrate, positioning the sacrificial cover layer and the glass substrate into a carrier ring.

13. The method of claim 1, wherein the laser beam has a wavelength of about 355 nm, the laser beam is has a pulse width between about 5 ns and about 75 ns, the laser beam is pulsed at a repetition rate between about 1 kHz and about 30 kHz, and the laser beam has a pulse energy between about 25 μ

J and about 175 μ

J.

14. The method of claim 1, wherein the laser beam has a wavelength of about 355 nm, the laser beam has a numerical aperture between about 0.02 and about 0.4, and a focus position of the laser beam is within about 100 μ

m of a surface of the sacrificial cover layer.