RFID tag

• US 20080040913A1
• Filed: 10/10/2007
• Published: 02/21/2008
• Est. Priority Date: 03/22/2005
• Status: Abandoned Application

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Baba, Shunji
• Application Number:
  US11/907,289
• Publication Number:
  US 20080040913A1
• Time in Patent Office: Days
• US Class Current: 29/601
• 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 manufacturing method, comprising:

providing an antenna pattern on a base, the antenna pattern forming a communication antenna and having an end portion for connection, the end portion having a shape that narrows in width toward an end providing a terminal for connection to the antenna;

placing an electric conductor onto the end portion for connection of the antenna pattern, the electrical conductor being smaller than the end portion for connection, between the end portion for connection of the antenna pattern and a circuit chip, which is electrically connected to the antenna pattern via the electric conductor and performs a radio communication by using the antenna; and

contacting the circuit chip against the base with the electric conductor put between the circuit chip and the antenna pattern, so that the electric conductor is pressed and sinks into the base along with a part of the antenna pattern.

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

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

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

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

7. The RFID tag manufacturing method 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 and inversely proportional to a gap between the circuit chip and the connection end portion of the antenna pattern.