Method for making touch panel

• US 20090159188A1
• Filed: 09/29/2008
• Published: 06/25/2009
• 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: Fan, Shou-Shan, Jiang, Kai-Li, Liu, Liang
• Granted Patent: US 8,585,855 B2
• Time in Patent Office: Days
• US Class Current: 156/235
• CPC Class Codes: G06F 3/045 using resistive elements, e.g. a single continuous surface or two parallel surfaces put in contact

Abstract

A method for making a touch panel includes the steps of: (a) providing a flexible substrate; (b) applying at least one carbon nanotube layer on the flexible substrate; (c) heat-pressing the carbon nanotube layer on the flexible substrate; (d) locating two electrodes on opposite ends of the flexible substrate; (e) placing an insulative layer on edges of a first surface of the flexible substrate, the first surface having the carbon nanotube layer formed thereon; and (f) securing the first electrode plate to a second electrode plate, with the insulative layer located between the first electrode plate and the second electrode plate, and wherein the carbon nanotube layer of the first electrode plate is adjacent to a carbon nanotube layer of the second electrode plate.

Claims

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

(a) providing a flexible substrate;

(b) applying at least one carbon nanotube layer on the flexible substrate;

(c) heat-pressing the carbon nanotube layer on the flexible substrate;

(d) locating two electrodes on opposite ends of the flexible substrate;

(e) placing an insulative layer on edges of a first surface of the flexible substrate, the first surface having the carbon nanotube layer formed thereon; and

(f) securing the first electrode plate to a second electrode plate, with the insulative layer located between the first electrode plate and the second electrode plate, and wherein the carbon nanotube layer of the first electrode plate is adjacent to a carbon nanotube layer of the second electrode plate.

2. The method as claimed in claim 1, further comprising the steps of:

(g) fabricating at least one carbon nanotube film;

wherein fabricating includes the following steps;

(g1) providing an array of carbon nanotubes; and

(g2) pulling out the carbon nanotube film from the array of carbon nanotubes by using a tool.

3. The method as claimed in claim 1, wherein before step (b), a step of cleaning the flexible substrate and coating the flexible substrate with low melting material is executed.

4. The method as claimed in claim 3, wherein an organic solvent is used to clean the flexible substrate, and the organic solvent comprises of ethanol, acetone or a combination thereof.

5. The method as claimed in claim 3, wherein the low melting material is coated on the flexible substrate by sputtering or spraying, and the melting point of the low melting material is lower than that of the flexible substrate and the at least one carbon nanotube layers.

6. The method as claimed in claim 1, wherein step (b) comprises one of the process of laying a first carbon nanotube film and a at least one more carbon nanotube film on a surface of the flexible substrate, so as to form the at least one carbon nanotube layer.

7. The method as claimed in claim 1, wherein (b) comprises the steps of:

(b1) laying one ore more carbon nanotube films on a surface of a supporter;

(b2) removing the supporter to form a free-standing carbon nanotube film structure; and

(b3) placing the carbon nanotube film structure on a surface of the flexible substrate, so as to form the at least one carbon nanotube layer.

8. The method as claimed in claim 7, wherein in step (b), a step of using an organic solvent to treat the carbon nanotube film, the carbon nanotube film structure, or the carbon nanotube layer.

9. The method as claimed in claim 1, wherein in step (b), at least two carbon nanotube layers is formed by at least two stacked carbon nanotube films, each carbon nanotube film comprises of carbon nanotubes, the carbon nanotubes are substantially oriented along a direction, and two adjacent carbon nanotube layers are arranged with an angle defined between the two adjacent carbon nanotubes'"'"' directions.

10. The method as claimed in claim 9, wherein the angle is in a range from above 0°

to less than or equal to 90°

.

11. The method as claimed in claim 1, wherein the step (c) comprises the substeps of:

(c1) locating the flexible substrate with the at least one carbon nanotube layers formed thereon in a hot-pressed device;

(c2) heating a pressing device of the hot-pressed device; and

(c3) squeezing the flexible substrate by the pressing device.

12. The method as claimed in claim 11, wherein the hot-pressed device comprises two rollers.

13. The method as claimed in claim 1, wherein step (d) further comprises the steps of:

(d1) applying a conductive silver paste on the substrate by means of screen printing or spraying; and

(d2) baking the substrate in an oven for 10-60 minutes at a temperature in an approximate range from 100°

C. to 120°

C. to solidify the conductive silver paste.

14. The method as claimed in claim 1, wherein step (e) is executed by applying a layer of insulative adherent agent.

15. The method as claimed in claim 1, further comprising the steps of applying a slurry comprising of a plurality of dot spacers on one of the electrode plates;

and drying the layer of slurry.

16. The method as claimed in claim 1, further comprising adhering a transparent protective layer on a first surface of the touch panel by an adhesive, and the adhesive is a silver-based slurry.

17. The method as claimed in claim 16, wherein the material of the transparent protective layer is selected from a group consisting of silicon nitride, silicon dioxide, benzocyclobutenes, polyester film, and polyethylene terephthalate.

18. The method as claimed in claim 16, further comprising placing a shielding layer on a second surface of the touch panel, and the material of the shielding layer is selected from a group consisting of indium tin oxides, antimony tin oxides, and carbon nanotube films.

19. The method as claimed in claim 18, wherein the shielding layer is adhered to the second surface of the touch panel by an adhesive, and the adhesive is a silver-based slurry.