RFID tag assembly methods

• US 8,661,652 B1
• Filed: 04/26/2012
• Issued: 03/04/2014
• Est. Priority Date: 03/11/2008
• Status: Active Grant

• Current Assignee: Impinj, Inc.
• Original Assignee: Impinj, Inc.
• Inventors: Koepp, Ronald L., Oliver, Ronald A., Colleran, William T., Ma, Yanjun, Fassett, Jay M., Moretti, Vincent C.
• Primary Examiner(s): TRINH, MINH N
• Application Number:
  US13/456,653
• Time in Patent Office: 677 Days
• Field of Search: 29600-601, 29830-832, 295/921, 298/55, 343/700.MS, 343/868, 3405722-5727
• US Class Current: 29/600
• CPC Class Codes: G06K 19/073 Special arrangements for circuits, e.g. for protecting identification code in memory protection against unauthorised use of computer memory G06F12/14
• CPC Class Codes: G06K 19/07754 the connection being galvanic
• CPC Class Codes: G06K 19/07756 the connection being non-galvanic, e.g. capacitive
• CPC Class Codes: H01P 11/00 Apparatus or processes specially adapted for manufacturing waveguides or resonators, lines, or other devices of the waveguide type
• CPC Class Codes: H01Q 1/2208 associated with components used in interrogation type services, i.e. in systems for information exchange between an interrogator/reader and a tag/transponder, e.g. in Radio Frequency Identification [RFID] systems methods or arrangements for sensing record carriers, e.g. for reading patterns G06K7/00; record carrier for use with machines and with at least a part designed to carry digital markings G06K19/00
• CPC Class Codes: H01Q 23/00 Antennas with active circuits or circuit elements integrated within them or attached to them
• CPC Class Codes: Y10T 29/49002 Electrical device making
• CPC Class Codes: Y10T 29/49016 Antenna or wave energy "plumbing" making

Abstract

RFID tags are assembled through affixing an antenna to an integrated circuit (IC) by forming one or more capacitors coupling the antenna and the IC with the dielectric material of the capacitor(s) including a non-conductive covering layer of the IC, a non-conductive covering layer of the antenna such as an oxide layer, and/or an additionally formed dielectric layer. Top and bottom plates of the capacitor(s) are formed by the antenna traces and one or more patches on a top surface of the IC.

Claims

1. A method for assembling a Radio Frequency Identification (RFID) tag, the method comprising:

affixing an integrated circuit (IC) to an antenna of the tag by forming a plurality of distinct conductive patches on the IC for coupling electrical circuitry of the IC to the antenna through a dielectric material, wherein;

the dielectric material includes at least one of a covering layer of the IC and a covering layer of the antenna; and

the plurality of distinct conductive patches are capacitively coupled to a rectifier circuit, a demodulator circuit, and a modulator circuit.

2. The method of claim 1, wherein the covering layer of the antenna includes an oxide layer formed on a conductive trace layer of the antenna.

3. The method of claim 2, wherein the covering layer of the antenna includes one from a set of:

a naturally occurring aluminum oxide, an enhanced growth of aluminum oxide, and a grown layer of aluminum nitride on a conductive trace layer of the antenna formed substantially from aluminum.

4. The method of claim 1, further comprising:

forming an additional dielectric layer between the covering layer of the antenna and the covering layer of the IC.

5. The method of claim 4, wherein the additional dielectric layer comprises adhesive material with controlled dielectric characteristics such that a capacitance between the antenna and the electrical circuitry of the IC is greater than a predetermined value.

6. A method for assembling a Radio Frequency Identification (RFID) tag, the method comprising:

affixing an integrated circuit (IC) to an antenna of the tag by forming a plurality of distinct conductive patches on the IC for coupling electrical circuitry of the IC to the antenna through a dielectric material, wherein;

the plurality of distinct conductive patches cover substantially an entire surface of the IC adjacent to the antenna;

the dielectric material includes at least one of a covering layer of the IC and a covering layer of the antenna; and

the plurality of distinct conductive patches are capacitively coupled to a rectifier circuit, a demodulator circuit, and a modulator circuit.

7. The method of claim 6, wherein a terminal of the antenna is affixed to a first surface of the IC, and the method further comprises:

affixing another antenna terminal to a second surface of the IC opposite the first surface, wherein at least one of the plurality of distinct conductive patches is on the first surface of the IC and another one of the plurality of distinct conductive patches is on the second surface of the IC.

8. The method of claim 6, wherein affixing the antenna to the IC includes:

terminating a metal deposition and patterning process of the IC before a passivation layer is deposited;

depositing on the IC a passivation material comprising the dielectric material; and

pressing together the antenna, the dielectric material, and the IC.

9. The method of claim 6, wherein the covering layer of the antenna includes an oxide layer formed on a conductive trace layer of the antenna.

10. The method of claim 9, wherein the covering layer of the antenna includes one from a set of:

a naturally occurring aluminum oxide, an enhanced growth of aluminum oxide, and a grown layer of aluminum nitride on a conductive trace layer of the antenna formed substantially from aluminum.

11. The method of claim 6, further comprising:

forming an additional dielectric layer between the covering layer of the antenna and the covering layer of the IC.

12. The method of claim 11, wherein the additional dielectric layer comprises adhesive material with controlled dielectric characteristics such that a capacitance between the antenna and the electrical circuitry of the IC is greater than a predetermined value.

13. The method of claim 6, wherein affixing the antenna to the IC includes:

terminating a metal deposition and patterning process of the IC before a passivation layer is deposited;

depositing on the IC a passivation material comprising the dielectric material; and

pressing together the antenna, the dielectric material, and the IC.