RFID tag

• US 7,298,273 B2
• Filed: 06/02/2005
• Issued: 11/20/2007
• Est. Priority Date: 03/22/2005
• Status: Expired due to Fees

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Baba, Shunji
• Primary Examiner(s): Trieu; Van T.
• Application Number:
  US11/142,356
• Publication Number:
  US 20060214793A1
• Time in Patent Office: 901 Days
• Field of Search: 340/572.1, 340/572.4, 340/572.5, 340/572.7, 340/10.34, 340/10.42, 340/572.8, 343/700.MS, 343/793
• US Class Current: 340/572.7
• 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 2924/01055 Cesium [Cs]
• CPC Class Codes: H01L 2924/3011 Impedance
• CPC Class Codes: H01Q 1/2225 used in active tags, i.e. provided with its own power source or in passive tags, i.e. deriving power from RF signal
• CPC Class Codes: Y10T 29/49016 Antenna or wave energy "plumbing" making
• CPC Class Codes: Y10T 29/49018 with other electrical component

Abstract

An RFID tag, including: a base; an antenna pattern that is provided on the base to form a communication antenna and has a tapered connection end portion which provides a connection terminal to the antenna; an electric conductor that is attached onto the connection end portion of the antenna pattern and is smaller than the connection end portion; and a circuit chip that is electrically connected to the antenna pattern via the electric conductor and performs radio communication by use of the antenna.

Claims

1. An RFID tag, comprising:

a base;

an antenna pattern that is provided on the base to form a communication antenna and has a connection end portion which has a shape that narrows in width toward an end and provides a connection terminal to the antenna;

an electric conductor that is attached onto the connection end portion of the antenna pattern and is smaller than the connection end portion; and

a circuit chip that is electrically connected to the antenna pattern via the electric conductor and performs radio communication by use of the antenna;

wherein at least a tip of the connection end portion is provided under the circuit chip; and

the electric conductor is sandwiched between the connection end portion and the circuit chip.

2. The RFID tag according to claim 1, wherein the antenna pattern has an inductance generation portion that generates an inductance suited to a capacitance between the connection end portion and the circuit chip and prevents performance deterioration of the antenna due to the capacitance.

3. The RFID tag according to claim 1, wherein the shape that narrows in width is tapered.

4. The RFID tag according to claim 1, wherein the shape that narrows in width is triangular.

5. The RFID tag according to claim 1, wherein the shape that narrows in width is tapered with a rounded end.

6. The RFID tag according to claim 1, wherein the shape that narrows in width is a shape that narrows by stages.

7. The RFID tag according to claim 1, wherein a parasitic capacity, which occurs in an overlapping portion where the circuit chip and the connection end portion of the antenna pattern overlap each other is proportional to the area of the overlapping portion end inversely proportional to a gap between the circuit chip and the connection end portion of the antenna pattern.

8. An RFID tag, comprising:

an antenna portion; and

a circuit chip coupled to the antenna portion by a conductor sandwiched between the antenna portion and the circuit chip;

wherein a surface area of the antenna portion in an overlapping portion of the antenna portion and circuit chip decreases in a direction of the circuit chip.

9. The RFID tag according to claim 8, wherein a gap between the antenna portion and the circuit chip is proportional to the overlapping portion.

10. An RFID tag, comprising:

an antenna portion; and

a circuit chip coupled to the antenna portion by a conductor sandwiched between the antenna portion and the circuit chip;

wherein a width of the antenna portion in an overlapping portion of the antenna portion and circuit chip is smaller than a width of the antenna portion outside the overlapping portion.