Projected Capacitive Touch Sensor With Asymmetric Bridge Pattern

• US 20150363025A1
• Filed: 08/26/2015
• Published: 12/17/2015
• Est. Priority Date: 04/19/2012
• Status: Active Grant

• Current Assignee: Elo Touch Solutions, Inc.
• Original Assignee: Elo Touch Solutions, Inc.
• Inventors: SON, Kyu-Tak
• Granted Patent: US 10,082,914 B2
• Time in Patent Office: Days
• 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 2203/04111 Cross over in capacitive digitiser, i.e. details of structures for connecting electrodes of the sensing pattern where the connections cross each other, e.g. bridge structures comprising an insulating layer, or vias through substrate
• CPC Class Codes: G06F 3/0443 using a single layer of sensing electrodes
• 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 17/9622 using a plurality of detectors, e.g. keyboard
• CPC Class Codes: Y10T 29/49155 Manufacturing circuit on or in base

Abstract

A capacitive touch sensitive device includes a matrix of pads patterned in a first electrically conductive material on a substrate. Horizontally adjacent pads within each even row of the matrix are electrically coupled to one another via channels to form a plurality of horizontally arranged electrodes. Insulators are positioned over respective channels. Conductive links are formed over respective insulators and are configured to electrically couple vertically adjacent pads between odd rows of the matrix to form a plurality of vertically arranged electrodes. The dimensions of the channels and the conductive links are configured such that an RC time-constant (RCtc) of each of the vertically arranged electrodes substantially matches an RCtc of each of the horizontally arranged electrodes.

Claims

1. A method of manufacturing a capacitive touch sensitive device, comprising:

patterning a matrix of pads in a first electrically conductive material on a substrate, wherein horizontally adjacent pads within each even row of the matrix of pads are electrically coupled to each other via channels to form a plurality of horizontally arranged electrodes;

positioning insulating material over the channels; and

forming conductive links over respective channels configured to electrically couple vertically adjacent pads between odd rows of the matrix of pads to form a plurality of vertically arranged electrodes, wherein dimensions of channels and the conductive links are configured such that an RC time constant (RCtc) of each of the vertically arranged electrodes substantially matches an RCtc of each of the horizontally arranged electrodes.

2. The method of claim 1, wherein the dimensions of the channels and the conductive links are configured such that electronic settling times are reduced to expedite touch location acquisition.

3. The method of claim 1, wherein the channels are patterned in a second conductive material.

4. The method of claim 3, wherein the second conductive material is a transparent conductive material having a sheet resistance of about 150 Ω

/sq.

5. The method of claim 1, wherein the conductive links are patterned in a second conductive material.

6. The method of claim 5, wherein the second conductive material is a transparent conductive material having a sheet resistance of about 200 Ω

/sq.

7. The method of claim 1, wherein positioning the insulating material over the channels comprises forming insulators positioned between respective channels and conductive links.

8. The method of claim 1, wherein the RCtc of each of the vertically arranged electrodes and the horizontally arranged electrodes is less than 6.5 μ

S.

9. The method of claim 1, wherein the RCtc of each of the vertically arranged electrodes is within ±

50% of the RCtc of each of the horizontally arranged electrodes.

10. The method of claim 1, wherein a total number of the vertically arranged electrodes is different than a total number of the horizontally arranged electrodes.

11. The method of claim 10, wherein a ratio of the total number of the vertically arranged electrodes to the total number of the horizontally arranged electrodes is about 16:

9.

12. The method of claim 1, further comprising:

patterning a pad in the matrix of pads into a diamond-shape having an area of about 18 mm².

13. A method of manufacturing a capacitive touch sensitive device, comprising:

patterning a matrix of pads in a conductive material, wherein horizontally adjacent pads within each even row of the matrix of pads are configured to form horizontally arranged electrodes in the conductive material, and vertically adjacent pads between odd rows of the matrix of pads are configured to form vertically arranged electrodes in the conductive material;

coupling the horizontally adjacent pads using channels, wherein each of the channels comprises a first dimension of about 0.4 mm in a horizontal direction, and a second dimension of about 1.0 mm in a vertical direction;

positioning an insulating material over the channels; and

forming conductive links over the channels to electrically couple the vertically adjacent pads, each of the conductive links comprising;

a third dimension of about 0.2 mm in the horizontal direction; and

a fourth dimension of about 1.2 mm in the vertical direction,

wherein the first, second, third, and fourth dimensions are configured such that a resistor-capacitor time constant (RCtc) of each of the vertically arranged electrodes substantially matches an RCtc of each of the horizontally arranged electrodes.

14. The method of claim 13, wherein the conductive material is a transparent conductive material having a sheet resistance of about 150 Ω

/sq.

15. The method of claim 13, wherein the conductive links are formed from a transparent conductive material having a sheet resistance of about 200 Ω

/sq.

16. The method of claim 13, wherein positioning the insulating material over the channels comprises forming insulators positioned between respective channels and conductive links.

17. The method of claim 13, wherein the RCtc of each of the vertically arranged electrodes and the horizontally arranged electrodes is less than 6.5 μ

S.

18. The method of claim 13, wherein the RCtc of each of the vertically arranged electrodes is within ±

50% of the RCtc of each of the horizontally arranged electrodes.

19. The method of claim 13, wherein a ratio of a total number of vertically arranged electrodes to a total number of horizontally arranged electrodes is about 16:

9.

20. The method of claim 13, wherein the horizontally arranged electrodes in the conductive material determine a vertical coordinate of a touch and the vertically adjacent electrodes determine a horizontal coordinate of the touch.