Surveillance Devices with Multiple Capacitors

• US 20100123582A1
• Filed: 05/15/2009
• Published: 05/20/2010
• Est. Priority Date: 05/15/2008
• Status: Active Grant

• Current Assignee: Ensurge Micropower ASA
• Original Assignee: Kovio Incorporated (Ensurge Micropower ASA)
• Inventors: Molesa, Steven, Kamath, Arvind, Smith, Patrick, Subramanian, Vivek, Cleeves, James Montague, Choi, Criswell
• Granted Patent: US 8,296,943 B2
• Time in Patent Office: Days
• US Class Current: 340/572.300
• CPC Class Codes: B31D 1/025 Applying patches, washers or reinforcements
• CPC Class Codes: G06K 19/07783 the coil being planar
• CPC Class Codes: G06K 19/07798 part of the antenna or the integrated circuit being adapted for rupturing or breaking, e.g. record carriers functioning as sealing devices for detecting not-authenticated opening of containers electronic seals G09F3/03
• CPC Class Codes: G08B 13/2414 using inductive tags
• CPC Class Codes: G08B 13/242 Tag deactivation
• CPC Class Codes: G08B 13/2431 Tag circuit details
• CPC Class Codes: G08B 13/2437 Tag layered structure, processes for making layered tags
• CPC Class Codes: G08B 13/2442 Tag materials and material properties thereof, e.g. magnetic material details
• CPC Class Codes: H01G 4/18 of synthetic material, e.g. derivatives of cellulose H01G4/16 takes precedence
• CPC Class Codes: Y10T 29/435 Solid dielectric type
• CPC Class Codes: Y10T 29/49016 Antenna or wave energy "plumbing" making
• CPC Class Codes: Y10T 29/49128 Assembling formed circuit to base
• CPC Class Codes: Y10T 29/49155 Manufacturing circuit on or in base

Abstract

The present invention relates to surveillance and/or identification devices having capacitors connected in parallel or in series, and methods of making and using such devices. Devices with capacitors connected in parallel, where one capacitor is fabricated with a relatively thick capacitor dielectric and another is fabricated with a relatively thin capacitor dielectric achieve both a high-precision capacitance and a low breakdown voltage for relatively easy surveillance tag deactivation. Devices with capacitors connected in series result in increased lateral dimensions of a small capacitor. This makes the capacitor easier to fabricate using techniques that may have relatively limited resolution capabilities.

Claims

1. A surveillance and/or identification device, comprising:

a) an electrically conducting strap on a substrate;

b) a lower capacitor electrode on or over the substrate, electrically connected to the strap;

c) a first dielectric film on the substrate and on or over a portion of the strap, the first dielectric film exposing a portion of the strap and having an opening over a portion of the lower capacitor electrode;

d) a capacitor dielectric film on the lower capacitor electrode in the opening, the capacitor dielectric film having a significantly smaller thickness than the first dielectric film;

e) an upper capacitor electrode on the first dielectric film and the capacitor dielectric film, the upper capacitor electrode capacitively coupled to the lower capacitor electrode; and

f) an antenna and/or inductor electrically connected to the upper capacitor electrode and the strap.

2. The device of claim 1, wherein the strap and the lower capacitor electrode comprise the same material.

3. The device of claim 1, wherein the capacitor dielectric film has a thickness of from 20 to 1000 Å

.

4. The device of claim 3, wherein the first dielectric film has a thickness of from 5000 to 20,000 Å

.

5. The device of claim 1, wherein the opening in the first dielectric film has an area not greater than 20% of the area between the upper and lower capacitor electrodes containing the first dielectric film.

23. A method of detecting items, comprising the steps of:

a) causing or inducing a current in the device of claim 1 sufficient for the device to radiate, absorb, or backscatter detectable electromagnetic radiation;

b) detecting the detectable electromagnetic radiation; and

c) optionally, selectively deactivating the device.

6. A method for making a surveillance and/or identification device, comprising the steps of:

a) forming an electrically conducting strap and a lower capacitor electrode on or over a substrate;

b) forming a first dielectric film on the substrate and on or over a portion of the strap, the first dielectric film exposing a portion of the strap and having an opening over a portion of the lower capacitor electrode;

c) forming a capacitor dielectric film in the opening, the capacitor dielectric film having a significantly smaller thickness than the first dielectric film;

d) forming an upper capacitor electrode on the first dielectric film and the capacitor dielectric film, such that the upper capacitor electrode is capacitively coupled to the lower capacitor electrode; and

e) forming an antenna and/or inductor on, or attaching the antenna and/or inductor to, the upper capacitor electrode and the strap.

7. The method of claim 6, wherein forming the strap comprises printing a conductor ink on the substrate.

8. The method of claim 6, wherein forming the first dielectric film comprises selectively depositing a first dielectric material on the strap and the lower electrode such that predetermined regions of the strap and the lower electrode are exposed.

9. The method of claim 8, wherein forming the first dielectric film comprises printing a dielectric precursor ink.

10. The method of claim 6, wherein forming the lower capacitor electrode comprises printing a metal ink on the capacitor dielectric film and the first dielectric film.

11. The method of claim 6, wherein forming the antenna and/or inductor comprises printing a continuous metal/conductor ink pattern on the upper capacitor electrode and the strap.

12. The method of claim 6, wherein forming the first dielectric film comprises the steps of (1) depositing a liquid-phase dielectric precursor ink, and (ii) drying and/or curing the dielectric precursor to form the dielectric film.

13. A surveillance and/or identification device, comprising:

a) an antenna and/or an inductor on a substrate;

b) a lower capacitor electrode, on or over the substrate and in electrical contact with the antenna and/or inductor;

c) a first dielectric film on or over the antenna and/or inductor and the lower capacitor electrode, the first dielectric film having a hole therein exposing a portion of the antenna and/or inductor and an opening therein over the lower capacitor electrode;

d) a relatively thin capacitor dielectric film on the lower capacitor electrode, in the opening in the first dielectric film and having a thickness significantly less than that of the first dielectric film;

e) an upper capacitor electrode, capacitively coupled to the lower capacitor electrode; and

f) an electrically conducting strap configured to provide electrical communication between the upper capacitor electrode and the antenna and/or inductor.

14. The device of claim 13, wherein the thin capacitor dielectric film comprises a corresponding oxide of a metal forming the lower capacitor electrode.

15. A method for making a surveillance and/or identification device, comprising the steps of:

a) forming an antenna and/or inductor on a substrate and a lower capacitor electrode in electrical communication with a first end of the antenna/inductor;

b) forming a relatively thin capacitor dielectric film on at least a first part of the lower capacitor electrode;

c) forming a relatively thick capacitor dielectric on or over a second part of the lower capacitor electrode, the second part of the lower capacitor electrode not overlapping with the first part thereof;

d) forming an upper capacitor electrode on the thin and thick capacitor dielectric films, capacitively coupled to the lower capacitor electrode; and

e) forming an electrically conducting strap configured to provide electrical communication between the upper capacitor electrode and a second end of the antenna/inductor.

16. The method of claim 15, further comprising forming a first dielectric film on the antenna/inductor prior to forming the lower capacitor electrode, wherein the first dielectric film has a contact hole therein exposing a portion of the antenna/inductor.

17. The method of claim 15, wherein forming the relatively thin capacitor dielectric film comprises thermally and/or chemically oxidizing an exposed surface of the lower capacitor electrode.

18. The method of claim 15, wherein forming the relatively thick capacitor dielectric film comprises selectively depositing a dielectric material on part of the lower capacitor electrode.

19. The method of claim 15, wherein forming the relatively thick capacitor dielectric film comprises printing a dielectric precursor ink, and drying and curing the dielectric precursor ink.

20. The method of claim 16, wherein forming the lower capacitor electrode comprises printing a metal ink in an opening in the first dielectric film exposing the first end of the antenna/inductor.

21. The method of claim 15, wherein forming the antenna and/or inductor comprises printing a metal/conductor ink.

22. The method of claim 15, wherein forming the relatively thick dielectric film comprises the steps of (1) depositing a liquid-phase dielectric precursor ink, and (ii) drying and/or curing the dielectric precursor.

24. A method for making a surveillance and/or identification device, comprising the steps of:

a) forming a first dielectric film on an electrically functional substrate;

b) forming a plurality of capacitor electrodes on the first dielectric film, the capacitor electrodes being capacitively coupled to the substrate and physically isolated from each other;

c) forming a second dielectric film on or over the capacitor electrodes, the second dielectric film having holes therein to facilitate electrical connection to the capacitor electrodes; and

d) forming an inductor electrically connected to each of the capacitor electrodes.

25. The method of claim 24, wherein the substrate, the first dielectric film, and the plurality of capacitor electrodes form a plurality of capacitors connected in series.

26. The method of claim 25, further comprising forming a third dielectric film on the first dielectric film, having openings therein for forming the capacitor electrodes.

27. The method of claim 24, wherein the second dielectric film is thicker than the first dielectric film.

28. The method of claim 26, wherein forming the capacitor electrodes comprises printing a metal ink into openings in the third dielectric film.

29. The method of claim 26, comprising forming the second dielectric film by selective deposition on the substrate such that openings are formed therein.

30. The method of claim 29, wherein forming the second dielectric film comprises printing a dielectric precursor ink.

31. The method of claim 26, wherein forming the third dielectric film comprises printing a dielectric precursor ink.

32. The method of claim 24, wherein the electrically functional substrate comprises a metal sheet or metal foil.

33. The method of claim 32, wherein the capacitor electrodes share the metal sheet or metal foil as a common electrode.

34. The method of claim 24, wherein forming the capacitor electrodes comprises depositing a metal/conductor onto at least part of the first dielectric film, and etching the metal/conductor.

35. The method of claim 24, wherein forming the second dielectric film comprises the steps of (i) depositing a liquid-phase dielectric precursor ink, and (ii) drying and/or curing the dielectric precursor to form the second dielectric film.

36. A surveillance and/or identification device, comprising:

a) an electrically conductive substrate;

b) a first dielectric film on the electrically conductive substrate;

c) a plurality of capacitor electrodes on the first dielectric film, capacitively coupled to the substrate and physically isolated from each other;

d) a second dielectric film on or over the capacitor electrodes, the second dielectric film having holes therein; and

e) an inductor electrically connected to the plurality of capacitor electrodes through the holes.

37. The device of claim 36, wherein the substrate, the first dielectric film, and the plurality of capacitor electrodes form a plurality of capacitors connected in series.

38. The device of claim 36, wherein the second dielectric film is thicker than the first dielectric film.

39. The device of claim 36, further comprising a third dielectric film on the first dielectric film, having openings therein for forming the capacitor electrodes.

40. The device of claim 36, wherein the first dielectric film comprises a corresponding oxide of a metal that forms the inductor.

41. The device of claim 36, wherein the second dielectric film comprises an oxide and/or nitride of a second Group IVA element.

42. The device of claim 36, wherein the electrically functional substrate comprises a metal sheet or metal foil.

43. The method of claim 42, wherein the capacitor electrodes share the metal sheet or metal foil as a common electrode.

44. A method of detecting items, comprising the steps of:

causing or inducing a current in the device of claim 36 sufficient for the device to radiate, absorb, or backscatter detectable electromagnetic radiation;

b) detecting the detectable electromagnetic radiation; and

c) optionally, selectively deactivating the device.