RFID tag

• US 7,277,017 B2
• Filed: 09/22/2005
• Issued: 10/02/2007
• Est. Priority Date: 04/05/2005
• Status: Expired due to Fees

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Kai, Manabu, Baba, Shunji, Maniwa, Toru, Yamagajo, Takashi
• Primary Examiner(s): Hofsass; Jeffery
• Assistant Examiner(s): Walk; Samuel J.
• Application Number:
  US11/232,035
• Publication Number:
  US 20060220871A1
• Time in Patent Office: 740 Days
• Field of Search: 340/572.1, 340/572.7, 340/572.8, 235/492
• US Class Current: 340/572.7
• 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 19/07381 with deactivation or otherwise incapacitation of at least a part of the circuit upon detected tampering
• CPC Class Codes: G06K 19/0739 the incapacitated circuit being part of an antenna
• 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 19/0775 arrangements for connecting the integrated circuit to the antenna
• CPC Class Codes: H01L 2224/16 of an individual bump connector
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/16227 the bump connector connecting to a bond pad of the item
• CPC Class Codes: H01L 2924/01004 Beryllium [Be]

Abstract

The present invention relates to an RFID tag and is provided with a function of detecting peeling while maintaining a good antenna characteristic. A first conductive pattern includes two extending sections extending from an IC chip, each end of which is connected to the IC chip, and a correction pattern for antenna characteristic correction which bypasses the IC chip and connects the two extending sections, and a peeling detection pattern is formed in an area enclosed by the two extending sections and the correction pattern.

Claims

1. An RFID tag comprising:

a base;

a first conductive pattern provided on the base, which operates as a communication antenna;

a second conductive pattern for peeling detection provided on the base, which is destroyed when peeled off the base;

a circuit chip electrically connected to both the first conductive pattern and the second conductive pattern, which carries out a radio communication using the first conductive pattern as an antenna and detects the destruction of the second conductive pattern; and

a cover covering the first conductive pattern, the second conductive pattern and the circuit chip, which is bonded to the base in a detachable manner and peeled off the base with the whole or part of the second conductive pattern remaining bonded,

wherein the first conductive pattern includes two extending sections extending from the circuit chip, each end of which is connected to the circuit chip and a correction pattern for antenna characteristic correction which bypasses the circuit chip and connects the two extending sections, and

the second conductive pattern is formed within an area enclosed by the two extending sections and the correction pattern.

2. The RFID tag according to claim 1, wherein the first conductive pattern comprises a pattern of a loop antenna, both ends of which are connected to the circuit chip.

3. The RFID tag according to claim 1, wherein the first conductive pattern comprises a pattern of a dipole antenna made up of two mono pole patterns, each end of which is connected to the circuit chip.

4. The RFID tag according to claim 1, wherein the correction pattern is an inductor which cancels out a parasitic capacitance produced between the circuit chip and the ends of the first conductive pattern connected to the circuit chip.

5. The RFID tag according to claim 1, wherein the second conductive pattern is a loop pattern, both ends of which are connected to the circuit chip, provided with peeling detection points at a plurality of locations on the loop of the second conductive pattern, which are peeled while remaining bonded to the cover when the cover is peeled off the base.