RFID tag with thermal conductive cover

• US 7,199,718 B2
• Filed: 03/22/2005
• Issued: 04/03/2007
• Est. Priority Date: 12/16/2004
• Status: Expired due to Fees

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Kikuchi, Shunichi, Suzuki, Masumi, Aoki, Michimasa
• Primary Examiner(s): Hofsass; Jeffery
• Assistant Examiner(s): Fan; Hongmin
• Application Number:
  US11/085,491
• Publication Number:
  US 20060145867A1
• Time in Patent Office: 742 Days
• Field of Search: 340/572.8, 235/492, 257/796, 257/679, 257/787, 358/1.15
• US Class Current: 340/572.8
• CPC Class Codes: B31D 1/028 Applying RFID chips
• CPC Class Codes: G06K 19/0773 the record carrier comprising means to protect itself against external heat sources
• 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: H01L 2224/0401 Bonding areas specifically adapted for bump connectors, e.g. under bump metallisation [UBM]
• CPC Class Codes: H01L 2224/16 of an individual bump connector
• CPC Class Codes: H01L 2924/00011 Not relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/15153 the die mounting substrate comprising a recess for hosting the device
• CPC Class Codes: H01L 2924/1517 Multilayer substrate
• CPC Class Codes: H01L 2924/3025 Electromagnetic shielding
• CPC Class Codes: Y10T 156/10 Methods of surface bonding and/or assembly therefor
• CPC Class Codes: Y10T 156/1056 Perforating lamina
• CPC Class Codes: Y10T 156/1062 Prior to assembly
• CPC Class Codes: Y10T 29/49117 Conductor or circuit manufacturing

Abstract

The present invention provides an RFID tag excellent in the diffusion of heat. The RFID tag includes a base, an antenna pattern that is provided on the base and forms a communication antenna, a circuit chip that is electrically connected to the antenna pattern and performs radio communication via the antenna, a cover that is provided in close contact with the base in such a manner as to cover the antenna pattern except a prescribed region including the circuit chip, and an insulating thermal diffusion material that covers the prescribed region and is in thermal contact with the circuit chip. The insulating thermal diffusion material has thermal conductivity higher than the thermal conductivity of the cover.

Claims

1. An RFID tag, comprising:

a base;

an antenna pattern that is provided on the base and forms a communication antenna;

a circuit chip that is electrically connected to the antenna pattern and performs radio communication via the antenna;

a cover that is provided in close contact with the base in such a manner as to cover the antenna pattern except a prescribed region including the circuit chip; and

an insulating thermal diffusion material that covers the prescribed region and is in thermal contact with the circuit chip, the insulating thermal diffusion material having thermal conductivity higher than the thermal conductivity of the cover.

2. The RFID tag according to claim 1, wherein the thermal diffusion material has a center part on the circuit chip and a protective part that encloses the center part, the height of the protective part being larger than the height of the center part.

3. The RFID tag according to claim 1, wherein the thermal diffusion material is formed by bonding a seat-like member to the prescribed region.

4. The RFID tag according to claim 1, wherein the thermal diffusion material is a liquid material that is applied to the prescribed region and has solidified.

5. The RFID tag according to claim 1, wherein the thermal diffusion material is an insulating material into which a thermally conductive granule having thermal conductivity higher than the thermal conductivity of the insulating material is mixed.

6. The RFID tag according to claim 1, wherein the thermal diffusion material has a lamellar structure including a first layer and a second layer that has thermal conductivity higher than the thermal conductivity of the first layer.