Touchscreen using both carbon nanoparticles and metal nanoparticles

• US 20090046073A1
• Filed: 08/14/2007
• Published: 02/19/2009
• Est. Priority Date: 08/14/2007
• Status: Active Grant

• Current Assignee: Elo Touch Solutions, Inc.
• Original Assignee: Tyco Electronics Corporation (TE Connectivity Limited)
• Inventors: Pennington, Brian D., Kent, Joel C.
• Granted Patent: US 8,199,118 B2
• Time in Patent Office: Days
• US Class Current: 345/173
• CPC Class Codes: G06F 3/045 using resistive elements, e.g. a single continuous surface or two parallel surfaces put in contact
• CPC Class Codes: Y10T 428/24994 Fiber embedded in or on the surface of a polymeric matrix

Abstract

A cover sheet assembly is provided for a touchscreen system. The cover sheet assembly includes an insulating layer having a surface configured to be disposed over an electrically conductive area of a substrate of the touchscreen system, and an electrically conductive material disposed on at least a portion of the surface of the insulating layer. The electrically conductive material includes a plurality of carbon nanoparticles and a plurality of metal nanoparticles.

Claims

1. A cover sheet assembly for a touchscreen system, said cover sheet assembly comprising:

an insulating layer having a surface configured to be disposed over an electrically conductive area of a substrate of the touchscreen system; and

an electrically conductive material disposed on at least a portion of the surface of the insulating layer, the electrically conductive material comprising a plurality of carbon nanoparticles and a plurality of metal nanoparticles.

2. The cover sheet assembly according to claim 1, wherein the electrically conductive material comprises first and second layers, the first layer being disposed directly on the surface of the insulating layer and the second layer being disposed directly on a surface of the first layer, the first layer comprising the plurality of the metal nanoparticles, the second layer comprising the plurality of carbon nanoparticles.

3. The cover sheet assembly according to claim 1, wherein the electrically conductive material comprises a single layer having a mixture of the plurality of carbon nanoparticles and the plurality of metal nanoparticles.

4. The cover sheet assembly according to claim 1, wherein at least one of the plurality of carbon nanoparticles and the plurality of metal nanoparticles are arranged in a pattern that is oriented with respect to a direction of a polarization of light such that at least a portion of the electrically conductive material has a predetermined transparency with respect to the polarization of light.

5. The cover sheet assembly according to claim 1, wherein at least one of the plurality of carbon nanoparticles and the plurality of metal nanoparticles are arranged in a pattern that is oriented in an alignment direction that is more aligned with a first direction than with a polarization direction of a polarization of light, the first direction being approximately perpendicular to the polarization direction of the polarization of light.

6. The cover sheet assembly according to claim 5, wherein the pattern of at least one of the plurality of carbon nanoparticles and the plurality of metal nanoparticles is oriented in an alignment direction that is approximately aligned with the first direction.

7. The cover sheet assembly according to claim 5, wherein the first direction is approximately perpendicular to the surface of the insulating layer.

8. The cover sheet assembly according to claim 1, wherein the metal nanoparticles comprise at least one of silver, bismuth, gold, nickel, tin, copper, and zinc nanoparticles.

9. The cover sheet assembly according to claim 1, wherein the plurality of metal nanoparticles and at least a portion of the plurality of carbon nanoparticles are at least partially contained by a polymer matrix.

10. The cover sheet assembly according to claim 1, wherein the plurality of carbon nanoparticles comprise at least one of carbon nanotubes, carbon nanospheres, carbon nanofibers, and carbon nanowires, the plurality of metal nanoparticles comprising at least one of metal nanofibers, metal nanospheres, metal nanotubes, and metal nanowires.

11. A substrate assembly for a touchscreen system, said substrate assembly comprising:

a substrate; and

an electrically conductive material disposed on at least a portion of a surface of the substrate to provide an electrically conductive touch area on the substrate, the electrically conductive material comprising a plurality of carbon nanoparticles and a plurality of metal nanoparticles.

12. The substrate assembly according to claim 11, wherein the electrically conductive material comprises first and second layers, the first layer being disposed directly on the substrate surface and the second layer being disposed directly on a surface of the first layer, the first layer comprising the plurality of the metal nanoparticles, the second layer comprising the plurality of carbon nanoparticles.

13. The substrate assembly according to claim 11, wherein the electrically conductive material comprises a single layer having a mixture of the plurality of carbon nanoparticles and the plurality of metal nanoparticles.

14. The substrate assembly according to claim 11, wherein at least one of the plurality of carbon nanoparticles and the plurality of metal nanoparticles are arranged in a pattern that is oriented in an alignment direction that is more aligned with a first direction than with a polarization direction of a polarization of light, the first direction being approximately perpendicular to the polarization direction of the polarization of light.

15. The substrate assembly according to claim 14, wherein the pattern of at least one of the plurality of carbon nanoparticles and the plurality of metal nanoparticles is oriented in an alignment direction that is approximately aligned with the first direction.

16. The substrate assembly according to claim 14, wherein the first direction is approximately perpendicular to the surface of the substrate.

17. The substrate assembly according to claim 11, further comprising a cover sheet positioned over the touch area on the substrate, the cover sheet comprising an insulating layer and a second electrically conductive material disposed on at least a portion of a surface of the insulating layer that generally faces the substrate.

18. The substrate assembly according to claim 17, wherein the plurality of carbon nanoparticles is a first plurality of carbon nanoparticles, and the plurality of metal nanoparticles is a first plurality of metal nanoparticles, the second electrically conductive material comprising a second plurality of carbon nanoparticles and a second plurality of metal nanoparticles.

19. An electrically conductive material comprising a plurality of carbon nanoparticles and a plurality of metal nanoparticles.

20. The electrically conductive material according to claim 19, wherein the electrically conductive material has a contact resistance of less than about 2000 Ohms and a sheet resistance of less than about 2000 Ohms/square when the electrically conductive material is used as a coversheet of a resistive touchscreen system.