POSITION-SENSING PANEL AND METHOD

• US 20120013544A1
• Filed: 07/16/2010
• Published: 01/19/2012
• Est. Priority Date: 07/16/2010
• Status: Active Grant

• Current Assignee: Neodrón Limited (Atlantic IP Services Limited)
• Original Assignee: Atmel Corporation (Microchip Technology Incorporated)
• Inventors: Philipp, Harald
• Granted Patent: US 9,081,427 B2
• Time in Patent Office: Days
• US Class Current: 345/173
• CPC Class Codes: G06F 2203/04103 Manufacturing, i.e. details related to manufacturing processes specially suited for touch sensitive devices
• CPC Class Codes: G06F 2203/04112 Electrode mesh in capacitive digitiser: electrode for touch sensing is formed of a mesh of very fine, normally metallic, interconnected lines that are almost invisible to see. This provides a quite large but transparent electrode surface, without need for ITO or similar transparent conductive material
• CPC Class Codes: G06F 3/041 Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• 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: H03K 17/962 Capacitive touch switches
• CPC Class Codes: H05K 2203/0709 Catalytic ink or adhesive for electroless plating catalyst filler H05K2201/0236
• CPC Class Codes: H05K 3/182 characterised by the patterning method
• CPC Class Codes: H05K 3/185 by making a catalytic pattern by photo-imaging

Abstract

An exemplary touch position sensing panel includes an opaque electrode layer and a transparent electrode layer separated from the opaque electrode layer by a substrate. The electrodes are arranged such that nodes are formed in areas where the electrodes cross over each other. The transparent electrode layer shields the opaque layer from electric field noise from electric field sources underlying the position-sensing panel, such as a display, while at the same time providing transparency to light emitted from the underlying display. Techniques are also discussed for forming the transparent electrode layer and/or the opaque electrode layer.

Claims

1. A touch position-sensing panel comprising:

a sensing area;

a substrate;

a plurality of first electrodes formed of a transparent conductive material, provided on a first side of the substrate; and

a plurality of second electrodes formed of an opaque material, provided on a second side of the substrate, opposite the first side, wherein;

the plurality of first electrodes are arranged in a first direction,

the plurality of second electrodes are arranged in a second direction different from the first direction such that the first and second electrodes cross over each other to form touch sensing nodes in the sensing area,

the transparent conductive material of the first electrode extends across substantially the entire sensing area, and

the second electrodes formed of the opaque conductive material are sized and patterned to provide gaps between the second electrodes to allow visible transmission of light through the panel.

2. The touch position-sensing panel of claim 1, wherein said first electrodes cover 90% or more of the node area.

3. The touch position-sensing panel of claim 1, wherein said plurality of first electrodes are comprised of indium tin oxide.

4. The touch position-sensing panel of claim 1, wherein the plurality of second electrodes are comprised of metal.

5. The touch position-sensing panel of claim 4, wherein the plurality of second electrodes are comprised of at least one metal selected from the group consisting of copper, silver, gold, aluminum, and tin.

6. The touch position-sensing panel of claim 1, further comprising a plurality of third electrodes arranged on the first surface.

7. The touch position-sensing panel of claim 6, wherein the plurality of third electrodes are comprised of metal.

8. The touch position-sensing panel of claim 7, wherein the plurality of third electrodes are comprised of at least one selected from the group consisting of copper, silver, gold, aluminum, and tin.

9. The touch position-sensing panel of claim 1, wherein the first electrodes are configured to shield the second electrodes from electrical noise.

10. The touch position-sensing panel of claim 1, wherein the plurality of second electrodes are arranged in anti-moire pattern.

11. The touch position-sensing panel of claim 6, wherein the plurality of third electrodes are arranged in anti-moire pattern.

12. The position-sensing panel of claim 1, wherein a gap between the plurality of first electrodes is 200 microns or less.

18. The touch position-sensing panel of claim 1, wherein the first electrode is on a first surface of the substrate and the second electrode is on a second surface of the substrate opposite the first surface.

13. A process of patterning electrodes of a touch position-sensing panel comprises steps of:

depositing a positive or negative resist over an unpatterned indium-tin-oxide (ITO) electrode on a substrate;

exposing the resist to UV light through a mask of the appropriate pattern;

developing the resist;

etching exposed ITO using an etching liquid; and

removing the resist using a removal liquid.

14. The process according to claim 13, further comprising a step of

depositing a metal electrode on a side of the substrate opposite the indium tin oxide electrode.

15. The process according to claim 14, wherein said metal electrode is comprised of at least one metal selected from the group consisting of copper, silver, gold, aluminum and tin.

16. A touch sensitive display device, comprising

a node area;

a substrate;

a plurality of first electrodes formed of a transparent conductive material provided on a first side of the substrate;

a plurality of second electrodes formed of an opaque conductive material; and

a display panel arranged adjacent to the first electrodes, wherein;

the plurality of first electrodes are arranged in a first direction,

the plurality of second electrodes are arranged in a second direction different from the first direction such that the first and second electrodes cross over each other to form touch sensing nodes in the sensing area,

the transparent conductive material extends across substantially the entire node area,

the second conductive electrodes formed of the opaque conductive material are sized and patterned to provide gaps between the second electrodes to allow visible transmission of light from the display through the panel, and

the plurality of first electrodes are arranged between the substrate and the touch-sensitive display panel.

17. The touch sensitive display device of claim 16, wherein the first electrodes are configured to shield the second electrodes from at least some noise from the display panel.

19. The touch sensitive display device of claim 16, wherein the first electrode is on a first surface of the substrate and the second electrode is on a second surface of the substrate opposite the first surface.