Radio frequency identification transponder having integrated antenna

• US 6,268,796 B1
• Filed: 12/12/1997
• Issued: 07/31/2001
• Est. Priority Date: 12/12/1997
• Status: Expired due to Fees

• Current Assignee: Hipoint Technology Incorporated
• Original Assignee: Hipoint Technology Incorporated
• Inventors: Linder, Stefan, Gnadinger, Alfred
• Primary Examiner(s): MULLEN, THOMAS J
• Application Number:
  US08/989,255
• Time in Patent Office: 1,327 Days
• Field of Search: 340/572.5, 340/572.7, 340/572.1, 343/741, 343/866, 428/901, 296/00, 296/01, 296/021, 257/673
• US Class Current: 340/572.5
• CPC Class Codes: G06K 19/0726 the arrangement including a circuit for tuning the resonance frequency of an antenna on the record carrier
• CPC Class Codes: G06K 19/07749 the record carrier being capable of non-contact communication, e.g. constructional details of the antenna of a non-contact smart card
• CPC Class Codes: G06K 19/07758 arrangements for adhering the record carrier to further objects or living beings, functioning as an identification tag
• CPC Class Codes: G06K 19/07775 the antenna being on-chip
• CPC Class Codes: G06K 19/07779 the inductive antenna being a coil
• CPC Class Codes: G06K 19/07781 the coil being fabricated in a winding process
• CPC Class Codes: G08B 13/2414 using inductive tags
• CPC Class Codes: G08B 13/2417 having a radio frequency identification chip
• 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: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01Q 7/06 with core of ferromagnetic material H01Q7/02 takes precedence

Abstract

A radio frequency identification device (RFID) has an antenna formed on a chip. The chip has backside and a front side coated with conductive traces, which are connected through conductive traces on the sides of two elongate through-hole slots formed on the chip to form an operative coil having the chip as a core. In one embodiment, the antenna chip may be stacked above an integrated circuit. In another embodiment, the integrated circuit may be formed on the antenna chip. The antenna chip may include a high magnetic permeability layer to increase the inductance of the coil, a capacitor to tune the coil to a desired frequency, and a coupling capacitor to power the integrated circuit. As well as the specific application disclosed, an inductance useful in numerous applications can be formed according to the above structure.

Claims

1. A Radio Frequency Identification (RFID) device comprising:

an antenna chip having a chip core, a chip front side, a chip backside, and conductive traces on the chip front side and chip backside, at least some of the traces on the chip front side being in electrical communication with at least some of the traces on the chip backside so that the conductive traces form an operative coil around the chip core;

an integrated circuit chip having an integrated circuit formed thereon, the integrated circuit having at least one of electronic memory and logic, integrated circuit being in electrical communication with the coil;

the integrated circuit chip being stacked in relation to the antenna chip and being mechanically attached thereto.

2. The RFID device of claim 1, wherein the antenna chip has two elongate through-hole slots, and some of the traces on the chip front side are connected to some of the traces on the chip backside through conductive material deposited on a portion of the slots.

3. The RFID device of claim 2, wherein:

the integrated circuit chip has electrical interconnect bumps electrically communicating with the integrated circuit;

the antenna chip has at least two contact pads, the at least two contact pads being electrically attached to some of the conductive traces so that one contact pad is electrically connected to a beginning of the coil and one contact pad is electrically connected to an end of the coil; and

the beginning and ending contact pads are mechanically and electrically connected to the interconnect bumps.

4. The RFID device of claim 3, further comprising stabilizing means for mechanically connecting the antenna chip and the integrated circuit chip in addition to the contact pads and interconnect bumps.

5. The RFID device of claim 4, wherein the stabilizing means comprise an antenna chip stabilizing contact pad and an integrated circuit chip stabilizing contact pad connected to the antenna chip contact pad.

6. The RFID device of claim 2, wherein the antenna chip includes a high magnetic permeability layer therewithin, such that the high magnetic permeability layer forms at least part of a core for the coil.

7. The RFID device of claim 6, wherein the high magnetic permeability layer is formed on the antenna chip backside.

8. The RFID device of claim 6, wherein the high magnetic permeability layer is formed on the antenna chip front side.

9. The RFID device of claim 2, further comprising a capacitor formed on the antenna chip.

10. The RFID device of claim 9, wherein the capacitor is a coupling capacitor for providing power to the integrated circuit.

11. The RFID device of claim 9, wherein the capacitor is a tuning capacitor.

12. The RFID device of claim 9, further comprising an additional capacitor formed on the antenna chip, one capacitor being a coupling capacitor and the other capacitor being a tuning capacitor.

13. The RFID device of claim 2, wherein the antenna chip is formed of intrinsic silicon.

14. A Radio Frequency Identification (RFID) device comprising:

an RFID chip having a chip core, a chip front side, a chip backside, and conductive traces on the chip front side and chip backside, some of the traces on the chip front side being in electrical contact with some of the traces on the chip backside so that the conductive traces form a coil around the chip core; and

an integrated circuit formed on the chip front side, the integrated circuit having at least one of electronic memory and logic, the integrated circuit being in electrical communication with the coil.

15. The RFID device of claim 14, wherein the chip has two elongate through-hole slots, and some of the traces on the chip front side are connected to some of the traces on the chip backside through conductive material deposited on a portion of the slots.

16. The RFID device of claim 15, wherein the chip has two contact pads formed on the chip front side, one of the contact pads being in electrical communication with at least one of the traces and the other contact pad being in electrical communication with at least another of the traces so that the one contact pad corresponds to a beginning of the coil and the other contact pad corresponds to an end of the coil;

and the integrated circuit has at least two bond pads, one bond pad being electrically connected to one of the contact pads and the other bond pad being electrically connected to the other contact pad.

17. The RFID device of claim 15, wherein the chip includes a high magnetic permeability layer therewithin, such that the high magnetic permeability layer forms at least part of a core for the coil.

18. The RFID device of claim 17, wherein the high magnetic permeability layer is disposed within a groove formed on the chip backside.

19. The RFID device of claim 17, wherein the high magnetic permeability layer is deposited in a damascene process.

20. The RFID device of claim 17, wherein the high magnetic permeability layer is deposited by physical vapor deposition.

21. The RFID device of claim 15, further comprising a capacitor formed on the chip.

22. The RFID device of claim 21, wherein the capacitor is a coupling capacitor for providing power to the integrated circuit.

23. The RFID device of claim 21, wherein the capacitor is a tuning capacitor.

24. The RFID device of claim 21, further comprising an additional capacitor on the chip, one capacitor being a coupling capacitor and the other capacitor being a tuning capacitor.

25. The RFID device of claim 15, further comprising a capacitor and a high magnetic permeability layer formed on the chip.

26. The RFID device of claim 25, wherein the capacitor and the high magnetic permeability layer are formed on the same chip side.

27. The RFID device of claim 26, wherein the capacitor and the high magnetic permeability layer are formed on the chip front side.

28. The RFID device of claim 26, wherein the capacitor and the high magnetic permeability layer are formed on the chip backside.

29. The RFID device of claim 25, wherein the capacitor and the high magnetic permeability layer are formed on opposite sides of the chip.