Method for making surveillance devices with multiple capacitors

• US 8,296,943 B2
• Filed: 05/15/2009
• Issued: 10/30/2012
• Est. Priority Date: 05/15/2008
• Status: Active Grant

• Current Assignee: Ensurge Micropower ASA
• Original Assignee: Kovio Incorporated (Ensurge Micropower ASA)
• Inventors: Smith, Patrick, Choi, Criswell, Cleeves, James Montague, Subramanian, Vivek, Kamath, Arvind, Molesa, Steven
• Primary Examiner(s): Nguyen, Donghai D.
• Application Number:
  US12/467,121
• Publication Number:
  US 20100123582A1
• Time in Patent Office: 1,264 Days
• Field of Search: 29/250.1, 29/250.2, 296/00, 296/011, 298/30, 298/31, 298/46, 298/47, 298/51, 174/257, 361/751, 361/765, 361/766, 361/795, 361/811, 428/210, 438/149, 438/190, 438/240
• US Class Current: 29/846
• 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 method for making a surveillance and/or identification device, comprising:

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

b) forming a first dielectric film on the substrate and on 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 (i) is capacitively coupled to the lower capacitor electrode and (ii) forms a first capacitor and a second capacitor connected in parallel, wherein the first capacitor includes the relatively thin capacitor dielectric film and the second capacitor includes the relatively thick dielectric film and the second capacitor has a greater capacitance than the first capacitor; and

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

2. The method of claim 1, wherein forming the strap comprises printing a conductor ink on the substrate.

3. The method of claim 1, 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.

4. The method of claim 3, wherein forming the first dielectric film comprises printing a dielectric precursor ink.

5. The method of claim 1, wherein forming the upper capacitor electrode comprises printing a metal ink on the capacitor dielectric film and the first dielectric film.

6. The method of claim 1, wherein forming the antenna and/or inductor comprises printing a continuous metal or conductor ink pattern on the upper capacitor electrode and the strap.

7. The method of claim 1, wherein forming the first 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 dielectric.

8. The method of claim 1, wherein the second capacitor has a greater area than that of the first capacitor.

9. The method of claim 1, wherein forming the electrically conducting strap and the lower capacitor electrode comprises printing a conductive seed layer, and electroplating or electrolessly plating a bulk conductor thereon.

10. The method of claim 1, wherein (i) the strap and the lower capacitor electrode are formed in a single processing step, and (ii) the lower capacitor electrode is shared by the first and second capacitors.

11. The method of claim 1, wherein forming the upper capacitor electrode and/or the lower capacitor electrode comprises printing a metal precursor ink, and drying and curing the metal precursor ink.

12. The method of claim 11, wherein printing comprises inkjet printing, microspotting, screen printing, gravure printing, offset printing, flexography, laser forward transfer, and/or local laser chemical vapor deposition.

13. The method of claim 11, wherein the metal precursor ink comprises titanium, tungsten, nickel, palladium, platinum, aluminum, gold, chromium, molybdenum, or a combination thereof.

14. The method of claim 11, wherein the metal precursor ink comprises one or more metal precursors selected from the group consisting of metal nanoparticles, organometallic compounds, and metal salts, in a solvent in which the metal precursor(s) are soluble.

15. The method of claim 1, wherein forming the upper capacitor electrode and/or the lower capacitor electrode comprises printing an ink comprising a metal nitride and/or a metal silicide.

16. The method of claim 15, wherein the ink comprises titanium nitride, titanium silicide, tantalum nitride, cobalt silicide, molybdenum silicide, tungsten silicide, platinum silicide, and/or palladium silicide.

17. The method 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.

18. The method of claim 1 wherein the relatively thin capacitor dielectric film comprises a corresponding oxide of a metal forming the lower capacitor electrode and/or the strap.

19. The method of claim 1, wherein forming the relatively thin capacitor dielectric film comprises thermally and/or chemically oxidizing an exposed surface of the lower capacitor electrode.

20. The method of claim 1, wherein forming the upper capacitor electrode and/or the lower capacitor electrode comprises depositing an element precursor ink comprising one or more Group IVA elements, a Group III, a Group IV, or a Group V material, and/or an organic or polymeric semiconductor at a thickness of from 50 to 200 nm to form a semiconductor layer and/or component.

21. The method of claim 20, wherein the element precursor ink comprises a dopant.

22. The method of claim 1, wherein forming the upper capacitor electrode and/or the lower capacitor electrode comprises priming a semiconductor layer.

23. The method of claim 22, further comprising doping the semiconductor layer.

24. The method of claim 23, wherein doping the semiconductor layer comprises implanting a dopant or diffusing the dopant into the semiconductor layer from a solid or a vapor dopant source.