CAPACITIVE TOUCH PANEL HAVING DUAL RESISTIVE LAYER

• US 20100139955A1
• Filed: 12/02/2009
• Published: 06/10/2010
• Est. Priority Date: 12/05/2008
• Status: Active Grant

• Current Assignee: New Vision Display (Hong Kong) Limited (New Vision Display, Inc.)
• Original Assignee: New Vision Display (Hong Kong) Limited (New Vision Display, Inc.)
• Inventors: Yu, Ying, Zhang, Hai Long, Long, Ding Hua
• Granted Patent: US 8,209,861 B2
• Time in Patent Office: Days
• US Class Current: 174/257
• CPC Class Codes: G06F 3/0445 using two or more layers of sensing electrodes, e.g. using two layers of electrodes separated by a dielectric layer
• CPC Class Codes: G06F 3/0446 using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes
• 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: G06F 3/047 using sets of wires, e.g. crossed wires
• CPC Class Codes: H05K 1/144 Stacked arrangements of planar printed circuit boards
• CPC Class Codes: H05K 2201/2036 Permanent spacer or stand-off in a printed circuit or printed circuit assembly pattern for applying drops or paste H05K2203/0545
• CPC Class Codes: H05K 2203/1572 Processing both sides of a PCB by the same process; Providing a similar arrangement of components on both sides; Making interlayer connections from two sides
• CPC Class Codes: H05K 3/323 by applying an anisotropic conductive adhesive layer over an array of pads
• CPC Class Codes: H05K 3/361 Assembling flexible printed circuits with other printed circuits
• CPC Class Codes: Y10T 29/49002 Electrical device making
• CPC Class Codes: Y10T 29/49117 Conductor or circuit manufacturing
• CPC Class Codes: Y10T 29/49124 On flat or curved insulated base, e.g., printed circuit, etc.
• CPC Class Codes: Y10T 29/49155 Manufacturing circuit on or in base
• CPC Class Codes: Y10T 29/49156 with selective destruction of conductive paths
• CPC Class Codes: Y10T 428/24802 Discontinuous or differential coating, impregnation or bond [e.g., artwork, printing, retouched photograph, etc.]
• CPC Class Codes: Y10T 428/24926 including ceramic, glass, porcelain or quartz layer

Abstract

A patterned substrate for a touch screen sensor assembly that includes a plurality of electrodes that are formed from a first transparent conductive layer that has a first surface resistivity. The substrate also has a plurality of traces that may be used to couple the electrodes controller associated with the touch screen sensor assembly. The traces are formed from a second conductive layer that has a second surface resistivity that is less than the surface resistivity of the first conductive layer. The first and second conductive layers may be formed from indium tin oxide (ITO) having different surface resistivities. A second, similarly configured substrate can be provided and may be spaced apart from the first substrate by a dielectric spacer.

Claims

1. A patterned substrate for use in a touch screen sensor assembly, the patterned substrate comprising;

a substrate;

a first non-metallic conductive layer disposed on the substrate, the first non-metallic conductive layer forming a pattern of electrodes; and

a second non-metallic conductive layer disposed on the substrate, the second non-metallic conductive layer forming a pattern of traces that are each electrically coupled to at least one of the electrodes;

wherein the second non-metallic conductive layer has a surface resistivity that is less than the first non-metallic conductive layer.

2. The patterned substrate of claim 1, wherein the second non-metallic conductive layer includes indium tin oxide.

3. The patterned substrate of claim 1, wherein the substrate is formed from a plastic material.

4. The patterned substrate of claim 1, wherein the substrate is formed from a glass material.

5. The patterned substrate of claim 1, wherein the first non-metallic conductive layer and the second non-metallic conductive layer include indium tin oxide.

6. The patterned substrate of claim 1, wherein the second non-metallic conductive layer has a surface resistivity of less than 20 ohms.

7. The patterned substrate of claim 1, wherein the first non-metallic conductive layer is disposed in a viewing portion of the substrate, wherein the viewing portion corresponds to an area of the substrate that is to be aligned with a display when the patterned substrate is configured as part of a touch screen sensor assembly, and wherein the second non-metallic conductive layer is on a portion of the substrate that does not include the viewing portion.

8. A method for manufacturing a patterned substrate for a touch screen sensor assembly, the method comprising:

providing a substrate;

depositing a first non-metallic conductive layer onto the substrate, wherein the first non-metallic conductive layer has a surface resistivity;

removing the first non-metallic conductive layer from the substrate in a viewing portion of the substrate, wherein the viewing portion corresponds to an area of the substrate that is to be aligned with a display when the patterned substrate is configured as part of a touch screen sensor assembly;

depositing a second non-metallic conductive layer onto the viewing portion of the substrate, wherein the second non-metallic conductive layer has a surface resistivity that is higher than that of the first non-metallic conductive layer;

removing portions of the second non-metallic conductive layer to form a pattern of electrodes; and

removing portions of the first non-metallic conductive layer to form a plurality of traces, wherein each trace is electrically coupled to at least one electrode.

9. The method of claim 8, wherein the second non-metallic conductive layer includes indium tin oxide.

10. The method of claim 8, wherein the substrate is formed from a plastic material.

11. The method of claim 8, wherein a vacuum sputtering process is used for depositing the first non-metallic conductive layer and the second non-metallic conductive layer.

12. The method of claim 8, wherein a photo etching process is used for removing portions of the first non-metallic conductive layer and the second non-metallic conductive layer.

13. The method of claim 8, wherein a photo etching process is used for removing portions of the first non-metallic conductive layer.

14. The method of claim 8, wherein the depositing of the first non-metallic conductive layer occurs prior to the depositing of the second non-metallic conductive layer.

15. A touch screen sensor assembly, comprising:

first and second substrates disposed in parallel with each other with a space therebetween, each of the first and second substrates including;

a first non-metallic conductive layer disposed on the substrate, the first non-metallic conductive layer forming a pattern of electrodes; and

a second non-metallic conductive layer disposed on the substrate, the second non-metallic conductive layer forming a pattern of traces that are each electrically coupled to at least one of the electrodes, wherein the second non-metallic conductive layer has a surface resistivity that is less than the first non-metallic conductive layer.

16. The touch screen sensor assembly of claim 15, wherein the second non-metallic conductive layer disposed on the first and second substrates includes indium tin oxide.

17. The touch screen sensor assembly of claim 15, further comprising:

a flexible printed circuit having a plurality of traces that are electrically coupled to the traces of the first and second substrates formed by the respective second non-metallic conductive layers.

18. The touch screen sensor assembly of claim 17, further comprising:

a first electrically conductive adhesive layer disposed between a first set of the plurality of traces of the flexible printed circuit and traces of the first substrate; and

a second electrically conductive adhesive layer disposed between a second set of the plurality of traces of the flexible printed circuit and traces of the second substrate.

19. The touch screen sensor assembly of claim 18, wherein the first and second electrically conductive adhesive layers include an anisotropic conductive adhesive (ACA).

20. The touch screen sensor assembly of claim 15, wherein each of the first and second substrates further include an optically clear adhesive layer disposed over the first non-metallic conductive layer.

21. The touch screen sensor assembly of claim 15, wherein the first and second substrates are separated by a dielectric adhesive layer.

22. The touch screen sensor assembly of claim 15, wherein, for each of the first and second substrates, the first and second non-metallic conductive layers are disposed in substantially the same plane.

23. The touch screen sensor assembly of claim 15, wherein, for each of the first and second substrates, the first non-metallic conductive layer is disposed in a viewing portion of the substrate, wherein the viewing portion corresponds to an area of the substrate that is to be aligned with a display, and wherein the second non-metallic conductive layer is disposed on a portion of the substrate that does not include the viewing portion.

24. A patterned substrate for use in a touch screen sensor assembly, the patterned substrate comprising;

a substrate;

a first ITO layer disposed on the substrate, the first ITO layer forming a pattern of electrodes; and

a second ITO layer disposed on the substrate, the second ITO layer forming a pattern of traces that are each electrically coupled to at least one of the electrodes;

wherein the second ITO layer has a surface resistivity that is less than that of the first ITO layer.

25. A method for manufacturing a touch screen sensor assembly, the method comprising:

providing a first transparent substrate;

depositing a first non-metallic conductive layer onto the first transparent substrate, wherein the first non-metallic conductive layer has a surface resistivity;

removing the first non-metallic conductive layer from the first transparent substrate in a viewing portion of the first transparent substrate, wherein the viewing portion corresponds to an area of the first transparent substrate that is to be aligned with a display;

depositing a second non-metallic conductive layer onto the viewing portion of the first transparent substrate, wherein the second non-metallic conductive layer has a surface resistivity that is higher than that of the first non-metallic conductive layer;

removing portions of the second non-metallic conductive layer from the first transparent substrate to form a first pattern of electrodes;

removing portions of the first non-metallic conductive layer from the first transparent substrate to form a plurality of traces;

providing a second transparent substrate;

depositing a third non-metallic conductive layer onto the viewing portion of the second transparent substrate, wherein the third non-metallic conductive layer has a surface resistivity that is substantially equal to that of the second non-metallic conductive layer;

removing portions of the third non-metallic conductive layer from the second transparent substrate to form a second pattern of electrodes; and

bonding the first transparent substrate to the second transparent substrate using an optically clear adhesive;

wherein each trace on the first transparent substrate formed from the first non-metallic conductive layer is electrically coupled to at least one electrode of either the first pattern of electrodes or the second pattern of electrodes.

26. The method of claim 25, further comprising:

providing a flexible printed circuit (FPC) connector having a plurality of electrical contacts; and

bonding the FPC connector to the first transparent substrate such that each trace is electrically coupled to at least one of the electrical contacts of the FPC connector.

27. The method of claim 26, wherein the FPC connector is bonded to the first transparent substrate using an anisotropic conductive film (ACF).

28. The method of claim 25, wherein at least one of the first, second, and third non-metallic conductive layers include indium tin oxide.