Projected capacitive touch sensor with asymmetric bridge pattern

• US 10,126,898 B2
• Filed: 02/28/2017
• Issued: 11/13/2018
• 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, Kent, Joel C.
• Primary Examiner(s): Ketema, Benyam
• Application Number:
  US15/445,885
• Publication Number:
  US 20170235393A1
• Time in Patent Office: 623 Days
• Field of Search: 345174
• 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 17/962 Capacitive touch switches
• CPC Class Codes: H03K 2217/960705 Safety of capacitive touch and proximity switches, e.g. increasing reliability, fail-safe

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 capacitive touch sensitive device, comprising:

drive electronics;

sense electronics;

a matrix of pads patterned in a first electrically conductive material on a substrate or multiple substrates, wherein horizontally adjacent pads in even rows of the matrix are electrically coupled to one another via channels to form a plurality of horizontally arranged electrodes; and

conductive links formed over respective channels configured to electrically couple vertically adjacent pads between odd rows of the matrix to form a plurality of vertically arranged electrodes,

wherein dimensions of the channels and the conductive links vary based upon respective positions of each electrode in the plurality of horizontally and vertically arranged electrodes, the respective positions being relative to a longest signal path in the matrix of pads, wherein distance traveled by a signal from the drive electronics to the sense electronics along the horizontally and vertically arranged electrodes is longest on the longest signal path.

2. The capacitive touch sensitive device of claim 1, further comprising:

a touch area defined by the matrix of pads and conductive links, wherein the touch area has at least a first region and a second region, the first region including a first width ratio between widths of channels and widths of their respective conductive links within the first region and the second region including a second width ratio between widths of channels and widths of their respective conductive links within the second region.

3. The capacitive touch sensitive device of claim 2, wherein the first width ratio is greater than the second width ratio.

4. The capacitive touch sensitive device of claim 2, wherein values of respective overlap areas between the channels and the respective conductive links vary over the touch area.

5. The capacitive touch sensitive device of claim 1, wherein a width ratio between widths of the channels and widths of their respective conductive links increases along the longest signal path.

6. The capacitive touch sensitive device of claim 1, wherein the plurality of horizontally arranged electrodes are disposed on a first surface of the substrate, and

wherein the plurality of vertically arranged electrodes are disposed on an opposing second surface of a second substrate.

7. The capacitive touch sensitive device of claim 1, further comprising one or more insulators positioned between the channels and their respective conductive links.

8. The capacitive touch sensitive device of claim 1, wherein a ratio of a total number of vertically arranged electrodes to a total number of horizontally arranged electrodes is approximately 16:

9.

9. The capacitive touch sensitive device of claim 1, wherein the channels are patterned in a transparent conductive material with a sheet resistance of approximately 150 Ω

/sq.

10. The capacitive touch sensitive device of claim 1, wherein the conductive links are formed from a transparent conductive material that has a sheet resistance of approximately 200 Ω

/sq.

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

patterning a matrix of pads in a first electrically conductive material on a substrate or multiple substrates, wherein horizontally adjacent pads in even rows of the matrix are electrically coupled to one another via channels to form a plurality of horizontally arranged electrodes; and

forming conductive links over respective channels configured to electrically couple vertically adjacent pads between odd rows of the matrix to form a plurality of vertically arranged electrodes,

wherein dimensions of the channels and the conductive links vary based upon respective positions of each electrode in the plurality of horizontally and vertically arranged electrodes, the respective positions being relative to a longest signal path in the matrix of pads, wherein distance traveled by a signal from drive electronics of the capacitive touch sensitive device to sense electronics of the capacitive touch sensitive device along the horizontally and vertically arranged electrodes is longest on the longest signal path.

12. The method of claim 11, wherein the matrix of pads and the conductive links define a touch area, wherein the touch area has at least a first and second region, the first region including a first width ratio between widths of channels and widths of their respective conductive links within the first region and the second region including a second width ratio between widths of channels and widths of their respective conductive links within the second region.

13. The method of claim 12, wherein the first width ratio is greater than the second width ratio.

14. The method of claim 11, wherein a width ratio between widths of the channels and widths of their respective conductive links increases along the longest signal path.

15. The method of claim 11, further comprising:

disposing the plurality of horizontally arranged electrodes on a first surface of the substrate; and

disposing the plurality of vertically arranged electrodes on an opposing second surface of a second substrate.

16. The method of claim 11, further comprising forming one or more insulators between the channels and their respective conductive links.

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

9.

18. The method of claim 11, wherein the channels are patterned in a transparent conductive material with a sheet resistance of approximately 150 Ω

/sq.

19. The method of claim 11, wherein the conductive links are formed from a transparent conductive material that has a sheet resistance of approximately 200 Ω

/sq.

20. A capacitive touch sensitive device, comprising:

drive electronics;

sense electronics;

a matrix of pads, defining a touch area, patterned in a first electrically conductive material on a substrate or multiple substrates, wherein horizontally adjacent pads in even rows of the matrix are electrically coupled to one another via channels to form a plurality of horizontally arranged electrodes; and

conductive links formed over respective channels configured to electrically couple vertically adjacent pads between odd rows of the matrix to form a plurality of vertically arranged electrodes;

wherein at least one resistor-capacitor time constant (RCtc) of the matrix is different from at least one other RCtc of the matrix, and

wherein dimensions of the channels and the conductive links vary based upon electrode position relative to a longest signal path in the matrix of pads, wherein distance traveled by a signal from the drive electronics to the sense electronics along the horizontally and vertically arranged electrodes is longest on the longest signal path.