INTEGRATED PASSIVE CIRCUIT ELEMENTS FOR SENSING DEVICES

• US 20110260741A1
• Filed: 04/27/2010
• Published: 10/27/2011
• Est. Priority Date: 04/27/2010
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Weaver, Billy L., Frey, Matthew H., Moran, Cristin E., Zu, Lijun
• Granted Patent: US 8,941,395 B2
• Time in Patent Office: Days
• US Class Current: 324/686
• CPC Class Codes: C23F 1/02 Local etching
• CPC Class Codes: C23F 1/14 Aqueous compositions
• CPC Class Codes: G01B 7/003 for measuring position, not involving coordinate determination coordinate measuring G01B7/004
• CPC Class Codes: G01R 27/2605 Measuring capacitance capacitive sensors G01D5/24
• 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 2203/04112 Electrode mesh in capacitive digitiser: electrode for touch sensing is formed of a mesh of very fine, normally metallic, interconnected lines that are almost invisible to see. This provides a quite large but transparent electrode surface, without need for ITO or similar transparent conductive material
• CPC Class Codes: G06F 3/0418 for error correction or compensation, e.g. based on parallax, calibration or alignment
• CPC Class Codes: G06F 3/04182 Filtering of noise external to the device and not generated by digitiser components
• CPC Class Codes: G06F 3/044 by capacitive means
• 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 2017/9602 characterised by the type or shape of the sensing electrodes
• CPC Class Codes: Y10T 29/49124 On flat or curved insulated base, e.g., printed circuit, etc.

Abstract

Capacitive sensing devices are provided that include a sensing pattern of conductive traces disposed upon the surface of a substrate and a first passive circuit element that includes a metallic conductor disposed upon the same surface of the substrate. In some embodiments, the first passive circuit element is a component of an electronic circuit that can be, for example, a low pass filter. Provided capacitive sensing devices are useful, for example, when incorporated into projected touch screen display panels for use on electronic devices.

Claims

1. A capacitive sensor comprising:

a substrate having a surface;

a touch-sensing pattern of metallic conductive traces disposed upon the surface of the substrate; and

a first passive circuit element comprising a metallic conductor disposed upon the same surface of the substrate.

2. A capacitive sensor according to claim 1, wherein the substrate comprises a visible light transparent substrate.

3. A capacitive sensor according to claim 2, wherein the substrate comprises a transparent polymer.

4. A capacitive sensor according to claim 1, wherein the sensing pattern of metallic conductive traces and the metallic conductor of the first passive circuit element comprise the same material.

5. A capacitive sensor according to claim 1, wherein the thickness of the sensing pattern of metallic conductive traces and the thickness of the metallic conductor of the first passive circuit element are substantially the same.

6. A capacitive sensor according to claim 1, wherein the first passive circuit element comprises a resistor, a capacitor, or an inductor comprising metal traces.

7. A capacitive sensor according to claim 6, wherein the first passive circuit element comprises a resistor that comprises a mesh of metallic traces.

8. A capacitive sensor according to claim 7, wherein the mesh comprises metallic traces having a width of less than about 2 microns.

9. A capacitive sensor according to claim 6, wherein the resistor has a resistance of from about 1 ohm to about 1,000 ohms.

10. A capacitive sensor according to claim 6, wherein the capacitor has a capacitance value of from about 1 picofarad to about 200 picofarads.

11. A capacitive sensor according to claim 6, wherein the inductor has an inductance value from about 0.01 henry to about 1.00 henry.

12. A capacitive sensor according to claim 1, further comprising one or more additional passive circuit elements comprising metallic conductor disposed upon the same surface of the substrate.

13. A capacitive sensor according to claim 12 wherein the one or more additional passive circuit elements form at least a portion of an electronic circuit.

14. A capacitive sensor according to claim 13, wherein the electronic circuit functions as a low-pass filter, a high-pass filter, or a band-pass filter.

15. A capacitive sensor according to claim 4, wherein the low-pass substantially filters out high frequencies above about 100 kHz.

16. A capacitive sensor according to claim 1, wherein the metallic conductive traces, the metallic conductor of the passive circuit element, or both comprise copper, silver, gold, or combinations thereof.

17. A method of making a capacitive sensor comprising:

providing a substrate comprising a metal coating disposed thereon; and

etching the metal to form a touch-sensing pattern of conductive metal traces disposed upon the substrate; and

at least one passive circuit element comprising a metallic conductor disposed upon the same surface of the substrate.

18. A method of making a capacitive sensor according to claim 17, further comprising contacting the raised features of an inked stamp to the metal coating before etching the metal coating.

19. A method of making a capacitive sensor according to claim 18 wherein the inked stamp comprises a self-assembled monolayer-forming molecule.