Touch panel and method for fabricating the same

• US 9,298,322 B2
• Filed: 03/11/2011
• Issued: 03/29/2016
• Est. Priority Date: 05/04/2010
• Status: Active Grant

• Current Assignee: Winsky Technology Limited
• Original Assignee: Winsky Technology Limited
• Inventors: Chan, Winston
• Primary Examiner(s): Sheikh, Humera
• Assistant Examiner(s): COLGAN, LAUREN ROBINSON
• Application Number:
  US13/046,244
• Publication Number:
  US 20110273386A1
• Time in Patent Office: 1,845 Days
• Field of Search: 428/426, 428/428, 428/432, 428/688, 428/689, 428/699, 428/701, 428/702, 428/410, 65/301.3, 65/301.4, 427/446, 427/559
• US Class Current: 1/1
• CPC Class Codes: G06F 2203/04103 Manufacturing, i.e. details related to manufacturing processes specially suited for touch sensitive devices
• CPC Class Codes: G06F 3/044 by capacitive means

Abstract

A touch panel and a method for fabricating the same are presented. The method includes the following steps. A glass substrate is strengthened through a chemical method. The glass substrate includes alkali oxide. An indium tin oxide (ITO) layer is formed below the glass substrate. A sensing circuit, a driving circuit, and an interconnection circuit therebetween are formed in the ITO layer.

Claims

1. A touch panel, comprising:

a glass substrate having a first surface serving as a touched surface and a second surface opposite to the first surface, strengthened through a chemical method, and comprising 60 wt % to 80 wt % silicon oxide, 1 wt % to 15 wt % aluminum oxide, and 0.1 wt % to 15 wt % alkali oxide, wherein the glass substrate has a compressive stress greater than 8 GPa measured by a 4 point-bending test; and

an indium tin oxide (ITO) layer formed on the second surface of the glass substrate, wherein a sensing circuit, a driving circuit, and an interconnection circuit therebetween are formed in the ITO layer.

2. The touch panel according to claim 1, wherein the glass substrate further comprises at least one of calcium oxide, magnesium oxide, iron oxide, boron oxide, and sulfur oxide.

3. The touch panel according to claim 1, wherein the sensing circuit, the driving circuit, and the interconnection circuit are formed by laser printing or ink jet printing.

4. The touch panel according to claim 1, wherein a light absorption rate of the radiation by the glass substrate is about 15%.

5. The touch panel according to claim 1, wherein a range of the light absorption rate of the radiation by the ITO layer is between about 8% and about 10%.

6. The touch panel according to claim 1, wherein no other substrate is present on or above the first surface of the glass substrate.

7. A method for fabricating a touch panel, comprising:

strengthening a glass substrate through a chemical method, wherein the glass substrate has a first surface serving as a touched surface and a second surface opposite to the first surface and wherein the glass substrate comprises 60 wt % to 80 wt % silicon oxide, 1 wt % to 15 wt % aluminum oxide, and 0.1 wt % to 15 wt % alkali oxide, and wherein the glass substrate has a compressive stress greater than 8 GPa measured by a 4 point-bending test;

forming an indium tin oxide (ITO) layer below the glass substrate; and

forming a sensing circuit, a driving circuit, and an interconnection circuit therebetween in the ITO layer.

8. The method according to claim 7, wherein the chemical method comprises:

immersing the glass substrate in a high temperature nitrous acid or nitric acid solution.

9. The method according to claim 7, wherein the sensing circuit, the driving circuit, and the interconnection circuit therebetween are formed by laser printing.

10. The method according to claim 9, wherein conditions of the laser printing comprise UV radiation of a Q-switch continuous wave laser having a radiation wavelength of 355 nm, a linear scanning velocity of about 1000 mm/sec, and energy smaller than 3 W.

11. The method according to claim 9, wherein conditions of the laser printing comprise pulse UV radiation having a radiation wavelength of 532 nm, a linear scanning velocity of about 120 mm/sec, and energy smaller than 120 mW.

12. The method according to claim 9, wherein conditions of the laser printing comprise infrared radiation having a wavelength of about 1064 nm, a frequency of 20 kHz, a linear scanning velocity of about 100 mm/sec to 500 mm/sec, and energy of about 100 mW to 800 mW.

13. The method according to claim 9, wherein a light absorption rate of the radiation by the glass substrate is about 15%.

14. The method according to claim 13, wherein a range of the light absorption rate of the radiation by the ITO is from about 8% to about 10%.

15. The method according to claim 7, wherein the sensing circuit is formed by printing conductive ink onto the glass substrate in an ink jet manner.

16. The method according to claim 15, further comprising an annealing process, wherein the temperature is lower than 205°

C.

17. The method according to claim 7, wherein the glass substrate has a surface stress of about 9 GPa.

18. The method according to claim 7, wherein the glass substrate comprises aluminum oxide, and the alkali oxide comprises lithium oxide (Li₂O) and/or sodium oxide (Na₂O).