Method of manufacturing a touch screen panel

• US 6,488,981 B1
• Filed: 06/20/2001
• Issued: 12/03/2002
• Est. Priority Date: 06/20/2001
• Status: Expired due to Term

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Bottari, Frank J., Richter, Paul J., Kardauskas, Michael J.
• Primary Examiner(s): BARR, MICHAEL E
• Application Number:
  US09/885,144
• Publication Number:
  US 20020197455A1
• Time in Patent Office: 531 Days
• Field of Search: 427/58, 427/126.2, 427/126.3, 427/123, 427/557, 427/376.1, 427/376.2, 427/376.3, 427/376.6, 427/383.1, 427/404, 427/419.2, 427/419.3, 427/248.1, 427/255.28, 427/430.1, 427/428, 427/258, 427/284, 427/264, 427/271, 427/162, 204/192.1
• US Class Current: 427/58
• CPC Class Codes: G06F 3/041 Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
• CPC Class Codes: G06F 3/0444 using a single conductive element covering the whole sensing surface, e.g. by sensing the electrical current flowing at the corners
• CPC Class Codes: Y10T 428/24777 Edge feature
• CPC Class Codes: Y10T 428/24917 including metal layer

Abstract

A method of manufacturing a touch screen panel, the method including applying a resistive coating to one surface of an insulative substrate, applying an insulative protective coating to the resistive coating, depositing a conductive edge electrode pattern including a plurality of edge electrodes on the protective coating, and firing the panel until the edge electrodes etch through the protective coating and make electrical contact with the resistive coating.

Claims

1. A method of manufacturing a touch screen panel, the method comprising:

applying a resistive coating to one surface of an insulative substrate;

applying an insulative protective coating to the resistive coating;

depositing a conductive edge electrode pattern including a plurality of edge electrodes on the protective coating; and

firing the panel until the edge electrodes etch through the protective coating and make electrical contact with the resistive coating.

2. The method of claim 1 in which the material of the edge electrodes includes conductive paste mixed with an additive.

3. The method of claim 2 in which the insulative protective coating includes silicon dioxide and the additive includes a chemical compound which is converted into a molten alkali hydroxide at elevated temperatures which dissolves the silicon dioxide of the protective coating.

4. The method of claim 3 in which the chemical compound is selected from the group consisting of sodium carbonates and sodium formates.

5. The method of claim 2 in which the conductive paste is a silver/frit composition.

6. The method of claim 2 in which the additive comprises 1-25% by weight of the conductive paste.

7. The method of claim 1 in which applying the resistive coating includes methods selected from the group consisting of sputtering, evaporation, chemical vapor deposition, meniscus coating, dip coating, screen printing, and pad printing.

8. The method of claim 1 in which the step of applying the insulative protective coating is a method selected from the group consisting of dip coating, meniscus coating, sputtering, evaporation, chemical vapor deposition, screen printing, and pad printing.

9. The method of claim 1 further including curing the insulative protective coating before the conductive edge electrode pattern is deposited thereon.

10. The method of claim 1 in which firing includes subjecting the panel to an elevated temperature.

11. The method of claim 10 in which firing further includes subjecting the panel to infrared radiation.

12. The method of claim 11 in which the infrared radiation has a wavelength of between 2.5 and 6.0 microns.

13. The method of claim 1 further including depositing a wire trace pattern on the protective coating and firing the panel until the wire trace pattern etches through the protective coating and makes electrical contact with the resistive coating.

14. The method of claim 13 in which the material of the wire trace pattern includes conductive paste mixed with an additive.

15. The method of claim 14 in which the insulative protective coating includes silicon dioxide and the additive includes a chemical compound which is converted into a molten alkali hydroxide at elevated temperatures which dissolves the silicon dioxide of the protective coating.

16. The method of claim 13 further including the step of providing electrical isolation between the wire trace pattern and the edge electrodes.

17. The method of claim 16 in which the step of providing electrical isolation includes using a laser to etch the protective material and the resistive material between the edge electrodes and the wire traces.

18. The method of claim 1 further including placing a wire trace pattern on the panel.

19. The method of claim 18 further including providing electrical isolation between the wire traces and the edge electrodes.

20. The method of claim 19 in which providing electrical isolation includes incorporating a dielectric layer between the wire trace pattern and the protective coating.

21. The method of claim 19 in which providing electrical isolation includes incorporating a dielectric layer between the edge electrodes and the wire traces.

22. The method of claim 19 in which providing electrical isolation includes not adding an additive to the material of the wire traces so they do not etch through the protective coating.

23. A method of manufacturing a touch screen panel, the method comprising:

applying a resistive coating to one surface of an insulative substrate;

applying an insulative protective coating to the resistive coating;

mixing a conductive paste with an additive;

depositing the mixture in the form of a conductive edge electrode pattern including a plurality of edge electrodes on the protective coating; and

firing the panel until the edge electrodes etch through the protective coating and make electrical contact with the resistive coating.

24. The method of claim 23 in which the insulative protective coating includes silicon dioxide and the additive includes a chemical compound which is converted into a molten alkali hydroxide at elevated temperatures which dissolves the silicon dioxide of the protective coating.

25. The method of claim 24 in which the chemical compound is selected from the group consisting of sodium carbonates and sodium formates.

26. The method of claim 23 in which the conductive paste is a silver/frit composition.

27. The method of claim 23 in which the additive comprises 1-25% by weight of the conductive paste.

28. The method of claim 23 further including depositing a wire trace pattern on the protective coating and firing the panel until the wire trace pattern etches through the protective coating and makes electrical contact with the resistive coating.

29. The method of claim 28 in which the material of the wire trace pattern includes conductive paste fixed with an additive.

30. The method of claim 29 in which the insulative protective coating includes silicon dioxide and the additive of the material of the wire trace pattern includes a chemical compound which is converted into a molten alkali hydroxide at elevated temperatures which dissolves the silicon dioxide of the protective coating.

31. The method of claim 28 further including the step of providing electrical isolation between the wire trace pattern and the edge electrodes.

32. The method of claim 31 in which the step of providing electrical isolation includes using a laser to etch the protective material and the resistive material between the edge electrodes and the wire traces.

33. The method of claim 23 further including placing a wire trace pattern on the panel.

34. The method of claim 33 further including providing electrical isolation between the wire traces and the edge electrodes.

35. The method of claim 34 in which providing electrical isolation includes incorporating a dielectric layer between the wire trace pattern and the protective coating.

36. The method of claim 34 in which providing electrical isolation includes incorporating a dielectric layer between the edge electrodes and the wire traces.

37. The method of claim 34 in which providing electrical isolation includes not adding an additive to the material of the wire traces so they do not etch through the protective coating.