Method for making touch panel

• US 8,574,393 B2
• Filed: 09/29/2008
• Issued: 11/05/2013
• Est. Priority Date: 12/21/2007
• Status: Active Grant

• Current Assignee: Hon Hai Precision Industry Co., Ltd., Tsinghua University
• Original Assignee: Hon Hai Precision Industry Co., Ltd., Tsinghua University
• Inventors: Jiang, Kai-Li, Liu, Liang, Fan, Shou-Shan
• Primary Examiner(s): Gupta, Yogendra
• Assistant Examiner(s): Patel, Vishal I
• Application Number:
  US12/286,195
• Publication Number:
  US 20090160799A1
• Time in Patent Office: 1,863 Days
• Field of Search: 156/281, 156/247, 156/305, 156/298, 156/311, 977/742, 445/24, 345/174, 345/173
• US Class Current: 156/311
• CPC Class Codes: G06F 3/044 by capacitive means
• CPC Class Codes: G06F 3/045 using resistive elements, e.g. a single continuous surface or two parallel surfaces put in contact

Abstract

An exemplary method for making a touch panel includes the steps of: providing a flexible substrate; fabricating a carbon nanotube film; laying the carbon nanotube film to form a carbon nanotube layer stacked on the flexible substrate; heat-pressing the carbon nanotube layer of the flexible substrate; and separately forming at least two electrodes on a surface of the carbon nanotube layer, thereby forming the touch panel.

Claims

1. A method for making a touch panel, the method comprising:

providing a flexible substrate of the touch panel;

placing at least one previously fabricated free-standing carbon nanotube film consisting of carbon nanotubes on the flexible substrate of the touch panel to form a carbon nanotube layer on the flexible substrate of the touch panel;

heat-pressing the carbon nanotube layer on the flexible substrate of the touch panel; and

forming at least two electrodes in contact with the carbon nanotube layer to achieve the touch panel.

2. The method as claimed in claim 1, wherein the placing the at least one previously fabricated carbon nanotube film on the flexible substrate of the touch panel comprises at least one step of:

contactingly laying at least two previously fabricated free-standing carbon nanotube films on the flexible substrate of the touch panel, and

stacking at least two previously fabricated free-standing carbon nanotube films on each other on the flexible substrate of the touch panel.

3. The method as claimed in claim 2, wherein each of the at least two previously fabricated free-standing carbon nanotube films comprises carbon nanotubes with a primary orientation and adjacent two previously fabricated free-standing carbon nanotube films are placed with an angle α

between their primary orientations, the angle α

is greater than 0° and

up to 90°

.

4. The method as claimed in claim 1, wherein before the placing the at least one previously fabricated free-standing carbon nanotube film on the flexible substrate of the touch panel, the method further comprises coating a low melting point material on a surface of the flexible substrate of the touch panel to have the at least one previously fabricated free-standing carbon nanotube film placed thereon.

5. The method as claimed in claim 4, wherein a melting point of the low melting point material is lower than a melting point of the flexible substrate of the touch panel and a melting point of the carbon nanotube layer.

6. The method as claimed in claim 1, further comprising using an organic solvent to treat one of the at least one carbon nanotube film and the carbon nanotube layer.

7. The method as claimed in claim 1, wherein the heat-pressing the carbon nanotube layer comprises:

disposing the flexible substrate of the touch panel with the carbon nanotube layer in a hot-pressed device;

heating a pressing device of the hot-pressed device; and

applying heat and pressure to the flexible substrate of the touch panel by the pressing device.

8. The method as claimed in claim 7, wherein the hot-pressed device is a hot-pressed machine, and the pressing device is two rollers.

9. The method as claimed in claim 1, further comprising applying a transparent protective film on a surface of the carbon nanotube layer.

10. The method as claimed in claim 9, wherein the transparent protective film is adhered to the surface of the carbon nanotube layer by an adhesive, and the adhesive is a silver-based slurry.

11. The method as claimed in claim 9, wherein the material of the transparent protective film is selected from silicon nitride, silicon dioxide, benzocyclobutenes, polyester film, and polyethylene terephthalate.

12. The method as claimed in claim 1, further comprising disposing a shielding layer on the flexible substrate of the touch panel.

13. The method as claimed in claim 12, wherein the material of the shielding layer is selected from the group consisting of indium tin oxide, antimony tin oxide, and carbon nanotube film.

14. The method as claimed in claim 12, wherein the shielding layer is adhered to a surface of the flexible substrate of the touch panel away from the carbon nanotube layer.

18. The method as claimed in claim 1, wherein the at least one previously fabricated free-standing carbon nanotube film is fabricated by:

providing an array of carbon nanotubes; and

pulling out a carbon nanotube film from the array of carbon nanotubes by using a tool.

15. A method for making a touch panel, the method comprising:

providing a flexible substrate of the touch panel;

drawing at least one carbon nanotube film from a carbon nanotube array, the at least one carbon nanotube film consisting of untreated carbon nanotubes;

laying the at least one carbon nanotube film on a surface of the flexible substrate of the touch panel to form a carbon nanotube layer on the flexible substrate of the touch panel;

heat-pressing the carbon nanotube layer on the surface of the flexible substrate of the touch panel; and

forming at least two electrodes in contact with the carbon nanotube layer to achieve the touch panel.

16. The method as claimed in claim 15, wherein the forming the at least two electrodes comprises forming four electrodes in directly contact with the carbon nanotube layer.

17. A method for making a touch panel, the method comprising:

providing a flexible substrate of the touch panel and at least two previously fabricated free-standing carbon nanotube films consisting of carbon nanotubes, each of the at least two previously fabricated free-standing carbon nanotube films comprising a plurality of carbon nanotubes aligned along a same direction;

stacking the at least two previously fabricated free-standing carbon nanotube films along different directions on the flexible substrate of the touch panel to form a carbon nanotube layer having the plurality of carbon nanotubes in adjacent two of the at least two previously fabricated carbon nanotube films aligned along different directions;

heat-pressing the carbon nanotube layer on the flexible substrate of the touch panel; and

forming at least two electrodes in contact with the carbon nanotube layer to achieve the touch panel.