Corrosion mitigation for metal traces

• US 9,236,202 B2
• Filed: 12/10/2012
• Issued: 01/12/2016
• Est. Priority Date: 09/10/2012
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Mohapatra, Siddharth, Kang, Sunggu, Zhong, John Z.
• Primary Examiner(s): LEE, KYUNG S
• Application Number:
  US13/710,417
• Publication Number:
  US 20140069785A1
• Time in Patent Office: 1,128 Days
• Field of Search: 200/600
• 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 2203/04107 Shielding in digitiser, i.e. guard or shielding arrangements, mostly for capacitive touchscreens, e.g. driven shields, driven grounds
• CPC Class Codes: G06F 3/041 Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
• CPC Class Codes: G06F 3/04164 Connections between sensors and controllers, e.g. routing lines between electrodes and connection pads
• 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: H01H 1/58 Electric connections to or between contacts; Terminals for high tension switches H01H33/025; for electromagnetic relays H01H50/14; for circuit breakers H01H71/08
• CPC Class Codes: H01H 11/04 of switch contacts
• CPC Class Codes: Y10T 29/49105 Switch making

Abstract

Processes for manufacturing touch sensors with one or more guard traces to reduce the effect of moisture damage are provided. One example process can include forming one or more guard traces between an edge of the touch sensor and the metal traces that route the drive and sense lines to bond pads. The one or more guard traces can be uncoupled from the drive lines and sense lines to protect the inner metal traces from moisture damage. In some examples, ends of the one or more guard traces can be coupled to ground by copper. In other examples, ends of the one or more guard traces can be coupled to ground by indium tin oxide or the one or more guard traces can be coupled to ground by a strip of indium tin oxide. In yet other examples, the guard trace can be floating (e.g., not coupled to ground).

Claims

1. A touch sensor comprising:

a plurality of sense lines;

a plurality of drive lines;

one or more bond pads;

a plurality of metal traces that couple together the one or more bond pads with the plurality of sense lines and the plurality of drive lines; and

a guard trace positioned between edges of the touch sensor and the plurality of conductive traces, wherein the guard trace is coupled to a sense line of the plurality of sense lines or a drive line of the plurality of drive lines, and wherein the guard trace is coupled to drive circuitry or sense circuitry operable to detect an open circuit in the guard trace.

2. The touch sensor of claim 1, wherein the guard trace is uncoupled from the plurality of sense lines and the plurality of drive lines.

3. The touch sensor of claim 1, wherein the touch sensor comprises a plurality of guard traces positioned between edges of the touch sensor and the plurality of conductive traces.

4. The touch sensor of claim 1, wherein the guard trace is coupled to a metal trace of the plurality of metal traces.

5. A touch sensor comprising:

a plurality of conductive traces that couple together one or more bond pads with a plurality of sense lines and a plurality of drive lines; and

a conductive guard trace positioned between an edge of the touch sensor and the plurality of conductive traces, wherein the conductive guard trace is coupled to one or more outer traces of the plurality of conductive traces and the conductive guard trace is coupled to drive circuitry or sense circuitry operable to detect an open circuit in the conductive guard trace.

6. The touch sensor of claim 5, wherein the conductive guard trace is coupled to the one or more outer traces of the plurality of conductive traces by copper.

7. The touch sensor of claim 5, wherein the conductive guard trace is coupled to the one or more outer traces of the plurality of conductive traces by indium tin oxide.

8. The touch sensor of claim 6, wherein the indium tin oxide is positioned along the conductive guard trace and between the conductive guard trace and the one or more outer traces of the plurality of conductive traces.

9. The touch sensor of claim 6, wherein the indium tin oxide is coupled between ends of the conductive guard trace and the one or more outer traces of the plurality of conductive traces.

10. A touch sensor comprising:

a plurality of sense lines;

a plurality of drive lines;

one or more bond pads; and

a plurality of conductive traces, wherein a first subset of the plurality of conductive traces is uncoupled from the plurality of sense lines and the plurality of drive lines, and wherein a second subset of the plurality of conductive traces couple together the one or more bond pads with the plurality of sense lines and the plurality of drive lines and ends of the first subset of the plurality of conductive traces are coupled to one or more outer traces of the second subset of the plurality of conductive traces by copper.

11. The touch sensor of claim 10, wherein the touch sensor comprises an indium tin oxide connector coupled between ends of the first subset of the plurality of conductive traces and one or more outer traces of the second subset of the plurality of conductive traces.

12. The touch sensor of claim 10, wherein the touch sensor comprises a strip of indium tin oxide along the first subset of the plurality of conductive traces and between the first subset of the plurality of conductive traces and the second subset of the plurality of conductive traces.

13. The touch sensor of claim 10, wherein the first subset of the plurality of conductive traces comprises copper.

14. The touch sensor of claim 10, wherein the first subset of the plurality of conductive traces is positioned between an edge of the touch sensor and the second subset of the plurality of conductive traces.

15. A method for manufacturing a touch sensor, the method comprising:

forming a plurality of sense lines;

forming a plurality of drive lines;

forming one or more bond pads; and

forming a plurality of conductive traces, wherein a first subset of the plurality of conductive traces is uncoupled from the plurality of sense lines and the plurality of drive lines, and wherein a second subset of the plurality of conductive traces couple together the one or more bond pads with the plurality of sense lines and the plurality of drive lines and a conductive trace of the first subset of the plurality of conductive traces is coupled to an outer trace of the second subset of the plurality of conductive traces.

16. The method of claim 15, wherein the first subset of the plurality of conductive traces is positioned between an edge of the touch sensor and the second subset of the plurality of conductive traces.

17. The method of claim 15, wherein the first subset of the plurality of conductive traces is coupled to an outer trace of the second subset of the plurality of conductive traces.

18. The method of claim 15, wherein the plurality of conductive traces comprise a metal.

19. A method for manufacturing a touch sensor, the method comprising:

forming a plurality of conductive traces that couple together one or more bond pads with a plurality of sense lines and a plurality of drive lines; and

forming a conductive guard trace positioned between edges of the touch sensor and the plurality of conductive traces, wherein the conductive guard trace is coupled to a sense line of the plurality of sense lines or a drive line of the plurality of drive lines, and the conductive guard trace is coupled to drive circuitry or sense circuitry operable to detect an open circuit in the conductive guard trace.

20. The method of claim 19, wherein the conductive guard trace is coupled to ground.

21. The method of claim 20, wherein the conductive guard trace is coupled to ground by copper or indium tin oxide.

22. The touch sensor of claim 19, wherein the guard trace is uncoupled from the plurality of sense lines and the plurality of drive lines.