Capacitive sensor having electrodes arranged on the substrate and the flex circuit

• US 8,816,967 B2
• Filed: 09/25/2008
• Issued: 08/26/2014
• Est. Priority Date: 09/25/2008
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Lyon, Benjamin, Fisher, Joseph, Rathnam, Lakshman
• Primary Examiner(s): Cheng, Joe H
• Assistant Examiner(s): CRAWLEY, KEITH L
• Application Number:
  US12/237,687
• Publication Number:
  US 20100073319A1
• Time in Patent Office: 2,161 Days
• Field of Search: 345173-178, 178 1801- 1811, 341/5, 341/20, 323/904
• US Class Current: 345/173
• 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 3/0445 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 17/9622 using a plurality of detectors, e.g. keyboard
• CPC Class Codes: H03K 2217/960755 Constructional details of capacitive touch and proximity switches
• CPC Class Codes: Y10T 29/43 Electric condenser making

Abstract

A capacitive sensor may include a flex circuit, a substrate facing the flex circuit, and conductive electrodes configured to sense an input applied to the substrate. At least one of the conductive electrodes is associated with a surface of the substrate and an at least one of the electrodes is associated with a surface of the flex circuit.

Claims

1. A capacitive sensor comprising:

a flex circuit,

a substrate, and

a plurality of conductive electrodes configured to sense an input associated with the substrate, the plurality of conductive electrodes comprising at least one electrode associated with a surface of the substrate and at least one electrode associated with a surface of the flex circuit,

a notch defined in the flex circuit, the notch establishing a physical gap in the flex circuit and a discontinuity in the at least one electrode associated with a surface of the flex circuit,

the at least one electrode associated with a surface of the substrate being configured so that the at least one electrode associated with a surface of the substrate fills at least a portion of the physical gap in the flex circuit and is continuous with and electrically coupled to the at least one electrode associated with a surface of the flex circuit when the substrate and the flex circuit are in a facing relationship.

2. The capacitive sensor of claim 1, wherein the substrate comprises at least one of a glass, plastic, ceramics, or polyethylene terephthalate (PET) material.

3. The capacitive sensor of claim 2, wherein the electrode associated with the surface of the substrate is formed via at least one of painting, printing or sputtering.

4. The capacitive sensor of claim 3, wherein a sensing area of the flex circuit is smaller than a total area of the substrate.

5. The capacitive sensor of claim 1, wherein the substrate comprises material having a sheet resistance less than 100 ohms/square area.

6. The capacitive sensor of claim 1, wherein the plurality of conductive electrodes comprises:

a first plurality of electrodes associated with the flex circuit in a first linear arrangement, the first plurality of electrodes being electrically coupled to each other, and

a second plurality of electrodes associated with the flex circuit in a second linear arrangement substantially perpendicular to the first linear arrangement, the second plurality of electrodes being electrically coupled to each other.

7. The capacitive sensor of claim 6, wherein the first plurality of electrodes are electrically coupled on the surface of the flex circuit and the second plurality of electrodes are electrically coupled on an opposite surface of the flex circuit using vias through which the second plurality of electrodes are connected to corresponding electrical patterns associated with the opposite surface of the flex circuit.

8. The capacitive sensor of claim 6, wherein the first plurality of electrodes are electrically coupled to each other on the surface of the flex circuit and the second plurality of electrodes are electrically coupled to each other, overlapping areas between adjacent ones of the second plurality of electrodes on the substrate, via a plurality of conductive patterns associated with the substrate.

9. The capacitive sensor of claim 6, wherein the electrode associated with the surface of the substrate comprises conductive material overlapping a portion of at least one of the first plurality of electrodes to electrically connect to the first plurality of electrodes.

10. The capacitive sensor of claim 6, wherein at least one of the first plurality of electrodes forms a mutual capacitance with at least one surrounding electrode of the second plurality of electrodes, an application of the input to the substrate causing a change in an electric charge of the at least one surrounding electrode indicative of the location of the application of the input.

11. The capacitive sensor of claim 6, wherein the plurality of conductive electrodes operate based on self-capacitance and both the first and second plurality of electrodes are sensed, an application of the input to the substrate creating a capacitance with at least one of the first plurality of electrodes and at least one of the plurality of second electrodes indicative of the location of the application of the input.

12. The capacitive sensor of claim 1, comprising a plurality of traces, at least one of the traces being coupled individually to one of the plurality of conductive electrodes.

13. The capacitive sensor of claim 12, wherein the plurality of conductive electrodes are arranged in a circular pattern.

14. A capacitive sensor comprising:

a flex circuit,

a substrate, and

a plurality of conductive electrodes configured to sense an input associated with the substrate, the plurality of conductive electrodes comprising a first plurality of electrodes having a first linear arrangement on a surface of the flex circuit and a second plurality of electrodes having a second linear arrangement on a surface of the substrate, an application of the input to the substrate causing a change in an electric charge of at least one electrode indicative of the location of an application of the input,

a notch defined in the flex circuit, the notch establishing a physical gap in the flex circuit and a discontinuity in at least one electrode associated with a surface of the flex circuit,

at least one electrode associated with a surface of the substrate being configured so that the at least one electrode associated with a surface of the substrate is continuous with and electrically coupled to the at least one electrode associated with a surface of the flex circuit and fills at least a portion of the physical gap in the flex circuit when the substrate and the flex circuit are in a facing relationship.

15. A capacitive sensor of claim 14, comprising an insulating layer arranged between the first and second plurality of electrodes.

16. The capacitive sensor of claim 14, wherein the substrate comprises at least one of a glass, plastic, ceramics, or polyethylene terephthalate (PET) material and the second plurality of electrodes are formed via at least one of painting, printing or sputtering.

17. A capacitive sensor comprising:

a flex circuit,

a substrate,

multiple conductive electrodes formed on and defining an electrode pattern on the flex circuit and configured to sense an input associated with the substrate, the multiple conductive electrodes comprising first electrodes and second electrodes, the first and second electrodes being mutually perpendicular and having an insulating layer therebetween, and

at least one electrode associated with a surface of the substrate and electrically connected to the first electrodes, wherein the substrate faces the flex circuit and the electrode associated with the substrate overlaps an area of the flex circuit that comprises a notch, wherein the notch prohibits placement of a portion of at least one of the first electrodes in a continuous pattern, the electrode associated with the substrate being configured to duplicate at least a portion of the electrode pattern on the flex circuit when the substrate and the flex circuit are in a facing relationship.

18. The capacitive sensor of claim 17, wherein the notch also displaces a pattern of the second plurality of electrodes, the capacitive sensor comprising:

at least one electrode associated with the surface of the substrate and coupled to the second plurality of electrodes, and

a layer of insulating material formed between the at least one electrode associated with the surface of the substrate and coupled to the first plurality of electrodes and the at least one electrode associated with the surface of the substrate and coupled to the second plurality of electrodes.

19. The capacitive sensor of claim 17, wherein the substrate comprises at least one of a glass, plastic, ceramics, or polyethylene terephthalate (PET) material, and the first electrode is formed on the surface of the substrate via at least one of painting, printing or sputtering.

20. A media player comprising a capacitive sensor, the capacitive sensor comprising:

a flex circuit,

a substrate, and

a plurality of conductive electrodes configured to sense an input associated with the substrate, the plurality of conductive electrodes comprising at least one electrode associated with a surface of the substrate and at least one electrode associated with a surface of the flex circuit,

a notch defined in the flex circuit, the notch establishing a physical gap in the flex circuit and a discontinuity in the at least one electrode associated with a surface of the flex circuit,

the at least one electrode associated with a surface of the substrate being configured to fill at least a portion of the physical gap in the flex circuit so that the at least one electrode associated with a surface of the substrate is continuous with and electrically coupled to the at least one electrode associated with a surface of the flex circuit when the substrate and the flex circuit are in a facing relationship.

21. A method of manufacturing a capacitive sensor, comprising:

forming at least one electrode associated with a surface of a substrate,

forming at least one electrode associated with a surface of a flex circuit, and

arranging the substrate and the flex circuit such that the electrode associated with the surface of the substrate and the electrode associated with the surface of the flex circuit are positioned between the substrate and the flex circuit,

a notch defined in the flex circuit, the notch establishing a physical gap in the flex circuit and a discontinuity in the at least one electrode associated with a surface of the flex circuit,

the at least one electrode associated with a surface of the substrate being configured to fill at least a portion of the physical gap in the flex circuit so that the at least one electrode associated with a surface of the substrate is continuous with and electrically coupled to the at least one electrode associated with a surface of the flex circuit when the substrate and the flex circuit are in a facing relationship.

22. The method of claim 21, comprising forming an insulating layer between the electrode associated with the surface of the substrate and the electrode associated with the surface of the flex circuit.

23. The method of claim 21, wherein the substrate comprises at least one of a glass, plastic, ceramics, or polyethylene terephthalate (PET) material and the step of forming the electrode associated with the surface of the substrate comprising at least one of painting, printing or sputtering a conductive material on the substrate.

24. The method of claim 21, wherein a sensing area of the flex circuit is smaller than the area of the substrate, the step of forming the electrode associated with the surface of the substrate comprising:

identifying an area of the substrate overlapping a notch of the flex circuit, and

forming the electrode associated with the surface of the substrate within the identified area.

25. The method of claim 21, further comprising:

forming a first plurality of electrodes on the flex circuit in a first linear arrangement, the first plurality of row electrodes being electrically coupled to each other, and

forming a second plurality of electrodes on the flex circuit in a second linear arrangement substantially perpendicular to the first linear arrangement, the second plurality of electrodes being electrically coupled to each other.

26. The method of claim 25, wherein the electrode associated with the surface of the substrate comprises conductive material overlapping a portion of at least one of the first plurality of electrodes to electrically connect to the first plurality of electrodes.

27. The method of claim 25, wherein at least one of the first plurality of electrodes forms a mutual capacitance with at least one adjacent electrode of the second plurality of electrodes, an application of an input to the substrate causing a change in an electric charge of the at least one adjacent electrode indicative of the location of the application of the input.

28. The method of claim 25, wherein the plurality of conductive electrodes operate based on self-capacitance, an application of an input to the substrate causing a change in electric charges of at least one of the first plurality of electrode and at least one of the plurality of second electrodes indicative of the location of the application of the input.

29. A capacitive sensor comprising:

a flex circuit comprising a surface,

a substrate comprising a surface,

multiple conductive electrodes configured to sense input, the multiple conductive electrodes comprising at least a first electrode and a second electrode, the first electrode being associated with the substrate surface and the second electrode defining an electrode pattern and being associated with the flex circuit surface,

a notch defined in the flex circuit, the notch establishing a discontinuity in the second electrode,

the first electrode being configured to duplicate at least a portion of the electrode pattern of the second electrode and electrically couple to the second electrode and eliminate the discontinuity when the substrate and the flex circuit are in a facing relationship.

30. A capacitive sensor comprising:

a flex circuit having a surface,

a substrate having a surface,

a first plurality of electrodes associated with the surface of the flex circuit,

a second plurality of electrodes defining an electrode pattern and being associated with the surface of the substrate,

at least one electrode associated with the surface of the substrate and at least one electrode associated with the surface of the flex circuit being electrically coupled when the substrate and the flex circuit are in a facing relationship, wherein both the first and second plurality of electrodes are configured to sense input associated with the substrate, the first plurality of electrodes being configured to duplicate at least a portion of the electrode pattern of the second plurality of electrodes when the substrate and the flex circuit are in a facing relationship.

31. The capacitive sensor of claim 30, wherein the substrate comprises at least one of glass, plastic, ceramics or polyethylene terephthalate (PET).

32. The capacitive sensor of claim 31, wherein the second plurality of electrodes are formed by at least one of painting, printing or sputtering.

33. The capacitive sensor of claim 30, wherein the substrate is characterized by a sheet resistance of less than 100 ohms/square area.

34. The capacitive sensor of claim 30, wherein

the first plurality of electrodes are electrically coupled to one another,

the second plurality of electrodes are electrically coupled to one another, and

the first plurality of electrodes and the second plurality of electrodes are mutually perpendicular when the substrate and the flex circuit are in a facing relationship.

35. The capacitive sensor of claim 30, comprising an insulating layer between the first and second plurality of electrodes.

36. A method of manufacturing a capacitive sensor, comprising:

forming a first plurality of electrodes on a surface of a flex circuit,

forming a second plurality of electrodes defining an electrode pattern on a surface of a substrate,

arranging the substrate and the flex circuit in a facing relationship wherein the first and second plurality of electrodes are positioned between the substrate and the flex circuit,

electrically coupling at least one of the first plurality of electrodes and at least one of the second plurality of electrodes,

wherein both the first and second plurality of electrodes are configured to sense input associated with the substrate, and wherein the first plurality of electrodes is configured to duplicate at least a portion of the electrode pattern of the second plurality of electrodes when the substrate and the flex circuit are in a facing relationship.

37. A capacitive sensor comprising:

a flex circuit comprising a surface,

a substrate comprising a surface,

multiple conductive electrodes, the multiple conductive electrodes comprising at least a first electrode and a second electrode, the first electrode being associated with the substrate surface and the second electrode defining an electrode pattern and being associated with the flex circuit surface,

the first and second electrodes being configured to be electrically coupled when the substrate and the flex circuit are in a facing relationship, wherein both the first and second plurality of electrodes are configured to sense input associated with the substrate, the first electrode being configured to duplicate at least a portion of the electrode pattern of the second electrode when the substrate and the flex circuit are in a facing relationship.