Method for producing a glass ceramic element with patterned coating

Patent metadata

Field	Value
Publication number	US-2016169531-A1
Application number	US-201514966403-A
Country	US
Kind code	A1
Filing date	Dec 11, 2015
Priority date	Dec 12, 2014
Publication date	Jun 16, 2016
Grant date	—

Abstract

A method is provided for producing a glass ceramic element with a patterned coating is provided. The method includes: providing a glass ceramic element with a coating which is at least partially light-blocking and preferably opaque in the visible spectral range; irradiating the glass ceramic element with a pulsed laser beam on the face provided with the coating so that the coating is removed by ablation; during irradiating the laser beam is directed over the surface of the glass ceramic element so that a portion of the coating is removed which has a greater lateral extent than the diameter of the laser beam; and once the coating has been removed, irradiating the glass ceramic with the laser in the region where the coating has been removed, thereby optically modifying the glass ceramic in the irradiated region.

First claim

What is claimed is:

1 . A method for producing a glass ceramic element with a patterned coating, comprising the steps of:
providing a side of a glass ceramic element with a coating, the coating being least partially light-blocking; directing a pulsed laser beam from a laser over a surface of the glass ceramic element to irradiate the surface so that a portion of the coating is removed by ablation in a region; and irradiating, once the coating has been removed from the region, the glass ceramic element with the same laser in the region to optically modifying the glass ceramic element in the region.

2 . The method as claimed in claim 1 , wherein the coating is opaque in a visible spectral range.

3 . The method as claimed in claim 1 , wherein the pulsed laser beam is directed on the side of the glass ceramic element on which the coating is provided.

4 . The method as claimed in claim 3 , wherein the pulsed laser beam comprises laser radiation of a wavelength of less than 800 nm.

5 . The method as claimed in claim 3 , wherein the pulsed laser beam comprises laser radiation comprises a pulse length of less than 1000 ps.

6 . The method as claimed in claim 1 , wherein the step of irradiating the glass ceramic element optically modifies the region by lowering a light transmittance of the region.

7 . The method as claimed in claim 1 , wherein the step of irradiating the glass ceramic element comprises maintaining an intensity of the laser below an ablation threshold of the glass ceramic element.

8 . The method as claimed in claim 1 , wherein the step of irradiating the glass ceramic element comprises setting a distance of a focus plane of the laser relative to the surface of the glass ceramic element to between 2 and 10 mm.

9 . The method as claimed in claim 1 , wherein the step of irradiating the glass ceramic element comprises setting a focus plane of the laser above or below the surface of the glass ceramic element.

10 . The method as claimed in claim 1 , further comprising providing the glass ceramic element as an element that is volume-colored by coloring metal ions, and wherein the step of irradiating the glass ceramic element to optically modify the glass ceramic element in the region comprises lowering an absorption coefficient of the region.

11 . The method as claimed in claim 1 , wherein the step of irradiating the glass ceramic element comprises:
selecting a power density of the pulsed laser beam so that the region of the glass ceramic is locally heated; and heating at least until a transmittance of the glass ceramic element is increased in a volume of the region; and allowing the region to cool.

12 . The method as claimed in claim 1 , wherein the step of irradiating the glass ceramic element comprises:
focusing the pulsed laser beam to an interior of the glass ceramic element; and setting an intensity of the laser above an ablation threshold of the glass ceramic element at the interior but not at the surface so that the glass ceramic element is optically modified by producing local dot-like light-scattering defects in the interior of the glass ceramic element without ablating the surface.

13 . The method as claimed in claim 1 , wherein the step of irradiating the glass ceramic element comprises maintaining an intensity of the laser abive an ablation threshold of the glass ceramic element at the surface so that the surface is ablated.

14 . The method as claimed in claim 1 , wherein the side of the glass ceramic element provided with the coating comprises a knobbed face, and wherein the step of directing the pulsed laser beam over the surface comprises removing the coating from the knobbed face.

15 . A plate-shaped glass ceramic element, comprising:
a glass ceramic with two opposite faces; a coating on at least one of the two opposite faces, the coating is at least partially light-blocking; and a pattern feature defined by a portion of the coating that has been removed, wherein the glass ceramic includes a first region having an optical property that has been modified relative to an adjacent region, wherein the first region and the adjacent region are monolithic so that the first region and the adjacent region merge into each other without joint, the first region having a contour that is offset from a contour of the pattern feature by not more than 20 μm.

16 . The glass ceramic element as claimed in claim 15 , wherein the coating is opaque in the visible spectral range.

17 . The glass ceramic element as claimed in claim 15 , wherein the coating comprises a plurality of layers.

18 . The glass ceramic element as claimed in claim 15 , wherein the optical property is light transmittance, and wherein the light transmittance of the first region is lowered with respect to the adjacent region.

19 . The glass ceramic element as claimed in claim 18 , further comprising a difference in light transmittances, (τ 1 −τ 2 )/(τ 1 +τ 2 ), with τ 1 being the light transmittance of the first region for a specific wavelength and τ 2 being the light transmittance of the adjacent region for the specific wavelength, that varies by not more than 30%.

20 . The glass ceramic element as claimed in claim 19 , wherein the difference in light transmittances varies by not more than 20%.

21 . The glass ceramic element as claimed in claim 19 , wherein the specific wavelength is a wavelength in a spectral range from 400 nm to 780 nm.

22 . The glass ceramic element as claimed in claim 15 , wherein the optical property is light absorption coefficient.

23 . The glass ceramic element as claimed in claim 22 , further comprising a difference in absorption coefficiences, (α 1 (λ)−α 2 (λ))/(α 1 (λ)+α 2 (λ)), with α 1 (λ) being the absorption coefficient of the first region and α 2 (λ) being the absorption coefficient of the adjacent region, that varies by not more than 30% in a range of wavelengths from 400 nm to 780 nm.

24 . The glass ceramic element as claimed in claim 23 , wherein the difference in absorption coefficiences varies by not more than 20%.

25 . The glass ceramic element as claimed in claim 15 , wherein the glass ceramic comprises an element selected from the group consisting of titanium, tin, iron, vanadium, chromium, cerium, neodymium, europium, manganese, cobalt, nickel, zinc, arsenic, antimony, copper, silver, gold, and any combinations thereof.

26 . The glass ceramic element as claimed in claim 15 , wherein the glass ceramic is volume-colored by vanadium oxide, and wherein the optical property in the first region that has been modified relative to the adjacent region comprises light transmittance in the visible spectral range, and wherein the light transmittance of the first region is increased as compared to the light transmittance of the adjacent region.

27 . The glass ceramic element as claimed in claim 15 , wherein the first region comprises local dot-like light scattering defects in the glass ceramic, the defects being sufficient to modify the optical property.

28 . The glass ceramic element as claimed in claim 15 , wherein the first region comprises a matt surface on the glass ceramic, the matt surface being sufficient to modify the optical property.

29 . The glass ceramic element as claimed in claim 15 , wherein the glass ceramic element is configured for use as a glass ceramic cooking pl

Assignees

• Schott Ag

Inventors

• Wagner Fabian
• Waldschmidt Holger

Classifications

• Y10T428/24942

  including components having same physical characteristic in differing degree · CPC title

• B32B2310/0843

  using laser · CPC title

• B32B18/00

  Layered products essentially comprising ceramics, e.g. refractory products · CPC title

• B41M5/24

  Ablative recording, e.g. by burning marks; Spark recording {(marking by high energetic means, e.g. by laser otherwise than burning or ablative removal B41M5/26; materials or methods for recording or reproduction by optical means G11B7/00)} · CPC title

• B23K26/36 Primary

  Removing material (B23K26/55, B23K26/57 take precedence) · CPC title