Thin Dielectric Layer For Touch Sensor Stack

• US 20130194198A1
• Filed: 02/01/2012
• Published: 08/01/2013
• Est. Priority Date: 02/01/2012
• Status: Abandoned Application

• Current Assignee: Atmel Corporation (Microchip Technology Incorporated)
• Original Assignee: David Brent Guard, Jalil Shaikh
• Inventors: Guard, David Brent, Shaikh, Jalil
• Application Number:
  US13/364,057
• Publication Number:
  US 20130194198A1
• 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 3/0443 using a single layer of sensing electrodes
• 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

Abstract

In one embodiment, a method for forming a touch sensor is provided. The method includes forming a substrate and a plurality of electrodes comprising one or more conductive materials on a first surface of the substrate. The method further includes forming a dielectric layer that is less than 40 microns thick over the plurality of electrodes and at least a portion of the first surface of the substrate, with no adhesive layer placed between the dielectric layer and the plurality of electrodes.

Claims

1. A touch sensor comprising:

a substrate comprising a first surface;

a plurality of electrodes comprising one or more conductive materials formed on the first surface of the substrate;

a dielectric layer formed on the plurality of electrodes and at least a portion of the first surface of the substrate, with no adhesive layer between the dielectric layer and the plurality of electrodes; and

a substantially transparent cover panel disposed on the dielectric layer through an in-mold lamination process.

2. The touch sensor of claim 1, wherein the dielectric layer has a thickness that is between about 0.5 microns and about 4 microns.

3. The touch sensor of claim 1, wherein the dielectric layer has a thickness that is between about 10 microns and about 50 microns.

4. The touch sensor of claim 1, wherein the dielectric layer comprises substantially transparent lacquer, poly(methyl methacrylate), or polycarbonate.

5. The touch sensor of claim 1, wherein the dielectric layer is formed by:

screen printing a dielectric material on the substrate and the plurality of electrodes;

applying a first segment of a first roll to a second segment of a second roll in a roll-to-roll process, the first segment of the first reel comprising the dielectric material and the second segment of the second reel comprising the substrate and the plurality of electrodes;

spraying the dielectric material on the substrate and the plurality of electrodes;

inkjet printing the dielectric material on the substrate and the plurality of electrodes;

or

immersing the substrate and the plurality of electrodes in the dielectric material.

6. The touch sensor of claim 1, the one or more conductive materials comprising indium tin oxide, a plurality of fine lines of metal, or a plurality of carbon nanotubes.

7. The touch sensor of claim 1, wherein the plurality of electrodes is a first plurality of electrodes, the substrate is a first substrate, and the dielectric layer is a first dielectric layer, the touch sensor further comprising:

a second plurality of electrodes comprising one or more conductive materials formed on a second surface of the first substrate or a second substrate; and

a second dielectric layer formed over at least a portion of the second surface of the first or second substrate and the second plurality of electrodes with no adhesive layer between the second dielectric layer and the second plurality of electrodes.

8. The touch sensor of claim 7, the second dielectric layer having a thickness that is approximately equal to a thickness of the first dielectric layer.

9. The touch sensor of claim 7, wherein the second dielectric layer faces the electronic display panel with an air gap between the second dielectric layer and the electronic display panel.

10. The touch sensor of claim 7, the second dielectric layer shaped such that it does not contact a plurality of connection pads formed on the second surface of the first or second substrate, the plurality of connection pads configured to couple a plurality of drive lines or sense lines of the touch sensor to a touch-sensor controller comprising one or more computer-readable non-transitory storage media embodying logic that is configured when executed to control the touch sensor.

11. The touch sensor of claim 10, the second dielectric layer having a thickness that is between about 2 microns and about 50 microns.

16. The touch sensor of claim 10, the one or more conductive materials comprising indium tin oxide, a plurality of fine lines of metal, or a plurality of carbon nanotubes.

12. A touch sensor comprising:

a substrate comprising a first surface;

a plurality of electrodes comprising one or more conductive materials formed on the first surface of the substrate; and

a dielectric layer formed over the plurality of electrodes and at least a portion of the first surface of the substrate, with no adhesive layer between the dielectric layer and the plurality of electrodes, the dielectric layer configured to face an electronic display panel with an air gap between the dielectric layer and the electronic display panel.

13. The touch sensor of claim 12, the dielectric layer comprising substantially clear lacquer, poly(methyl methacrylate), or polycarbonate.

14. The touch sensor of claim 12, wherein:

the dielectric layer has a thickness that is between about 2.0 microns and about 50 microns; and

a surface of the dielectric layer that does not contact the substrate is substantially flat.

15. The touch sensor of claim 12, wherein the plurality of electrodes is a first plurality of electrodes, the substrate is a first substrate, and the dielectric layer is a first dielectric layer, the touch sensor further comprising:

a second plurality of electrodes comprising one or more conductive materials formed on a second surface of the first substrate or a second substrate; and

a substantially transparent cover panel affixed to the second surface of the first or second substrate with a layer of optically clear adhesive.

17. A method for forming a touch sensor, the method comprising:

providing a substrate comprising a first surface;

forming a plurality of electrodes comprising one or more conductive materials on the first surface of the substrate; and

forming a dielectric layer on the plurality of electrodes and at least a portion of the first surface of the substrate, with no adhesive layer between the dielectric layer and the plurality of electrodes.

18. The method of claim 17, further comprising injecting a liquid resin into an in mold lamination tool, which forces the liquid resin against the dielectric layer to form a substantially transparent cover panel.

19. The method of claim 17, further comprising attaching a display panel to the substrate such that an electronic display panel faces the dielectric layer, with an air gap disposed between the dielectric layer and the display panel.

20. The method of claim 17, wherein the plurality of electrodes is a first plurality of electrodes, the substrate is a first substrate, and the dielectric layer is a first dielectric layer, the method further comprising:

forming a second plurality of electrodes comprising one or more conductive materials on a second surface of the first substrate or a second substrate; and

applying a second dielectric layer over the second plurality of electrodes and at least a portion of the second surface of the first or second substrate, with no adhesive layer between the second dielectric layer and the second surface of the first or second substrate.

21. A device comprising:

a touch sensor comprising;

a substrate comprising a first surface;

a plurality of electrodes comprising one or more conductive materials formed on the first surface of the substrate;

a dielectric layer formed on the plurality of electrodes and at least a portion of the first surface of the substrate, with no adhesive layer between the dielectric layer and the plurality of electrodes; and

a transparent cover panel disposed on the dielectric layer through an in-mold lamination process; and

one or more computer-readable non-transitory storage media coupled to the touch sensor and embodying logic that is configured when executed to control the touch sensor.