Transparent substrate with invisible electrodes and device incorporating the same

• US 20050116343A1
• Filed: 11/30/2004
• Published: 06/02/2005
• Est. Priority Date: 12/01/2003
• Status: Active Grant

• Current Assignee: The Swatch Group Research And Development Ltd
• Original Assignee: Asulab SA (The Swatch Group AG)
• Inventors: Grupp, Joachim, Poli, Gian-Carlo, Baroni, Pierre-Yves
• Granted Patent: US 7,843,061 B2
• Time in Patent Office: Days
• US Class Current: 257/749
• CPC Class Codes: G02F 1/13439 characterised by their electrical, optical, physical properties; materials therefor; method of making
• CPC Class Codes: G06F 3/041 Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: Y02E 10/50 Photovoltaic [PV] energy
• CPC Class Codes: Y10S 977/781 Possessing nonosized surface openings that extend partially into or completely through the host material
• CPC Class Codes: Y10S 977/784 Electrically conducting, semi-conducting, or semi-insulating host material

Abstract

The electrodes (7) and the contact zones (15) are structured in a film of a transparent conductive oxide (TCO), deposited on a transparent support (1) possibly coated with an intermediate film (3), while being separated by dielectric spaces (9) formed by nano fissures (11) obtained by UV radiation and passing through the TCO film.

A protective film (13) can coat the electrodes (7) and the dielectric spaces (9).

Claims

1. A transparent substrate with invisible electrodes including a transparent support on which there is deposited a transparent conductive film wherein electrodes and their contact zones are structured with contours separated by non-conductive spaces, wherein the conductive film located at the site of said non-conductive spaces includes nano fissures for interrupting the electrical conductivity between neighbouring electrodes, without altering the path of a light ray in a manner perceptible to the naked eye.

2. The substrate according to claim 1, wherein the transparent conductive film is a transparent conductive oxide (TCO), selected from the group comprising tin and indium oxide (ITO), In₂O₃ and SnO₂ doped with Sb.

3. The substrate according to claim 1, wherein the transparent conductive film is a doped conductive polymer with conjugated double bonds selected from among a polyacetylene and polyanilines.

4. The substrate according to claim 1, wherein an intermediate layer made of a transparent hard non-conductive material or hardcoating is inserted between the support and the conductive film.

5. The substrate according to claim 4, wherein the intermediate layer is formed of a resin incorporating SiO₂ and having a thickness at least equal to 20 μ

m.

6. The substrate according to claim 1, wherein the majority of the nano fissures pass through the entire conductive film.

7. The substrate according to claim 2, wherein the conductive film is an ITO film having a thickness comprised between 50 and 100 nm, preferably between 65 and 75 nm.

8. The substrate according to claim 1, wherein the support is made of a material selected from among polymethylene methacrylate (PMMA) and polycarbonate (PC).

9. The substrate according to claim 1, wherein the electrodes and the non-conductive spaces are further coated with a protective film also able to have anti-reflective properties.

10. The substrate according to claim 9, wherein the protective film does not cover the contact zones of the electrodes.

11. The substrate according to claim 1, wherein it forms a touch-type control screen for an electronic apparatus in which it is integrated.

12. The substrate according to claim 1, wherein it forms at least one closing plate for a liquid crystal display cell or a photovoltaic cell for an electronic apparatus.

13. A method of manufacturing a transparent substrate with invisible electrodes including a transparent support on which there is deposited a transparent conductive film wherein electrodes are structured with contours separated by non-conductive spaces, by UV radiation by means of a radiation source, wherein it comprises of the following steps:

placing the substrate, formed of the support and the conductive film possibly deposited on an intermediate layer made of a transparent hard non-conductive material, in a sealed enclosed space having a gaseous fluid supply inlet and a pump outlet;

inserting, between the UV radiation source and the substrate, a mask including windows transparent to UV radiation, said windows corresponding to the dielectric non-conductors, and

adjusting, as a function of the choice of materials used for the substrate and the emitting source, the UV radiation features to cause nano fissures to be created in the conductive film in the radiated zone, without removing any matter.

14. The method according to claim 13, wherein it includes an additional step of depositing a conductive film, which may be anti-reflective, from a precursor gas with the same UV source, but replacing the mask used by another mask corresponding to the desired useful surface of the transparent substrate, while leaving the contact zones of the electrodes visible.

15. The method according to claim 13, wherein the transparent conductive film is a transparent conductive oxide (TOC) selected from the group comprising tin and indium oxide (ITO), In₂O₃ and SnO₂ doped with Sb.

16. The method according to claim 13, wherein the transparent conductive film is a doped conductive polymer selected from among a polyacetylene and polyanilines.

17. The method according to claim 13, wherein the source is formed by an excimer laser selected from among XeF long pulse lasers and KrF short pulse lasers.