Antenna circuit constituent body for IC card/tag and IC card

• US 8,297,517 B2
• Filed: 04/28/2009
• Issued: 10/30/2012
• Est. Priority Date: 05/09/2008
• Status: Active Grant

• Current Assignee: Toyo Aluminium Kabushiki Kaisha (Nippon Light Metal Holdings Co., Ltd.)
• Original Assignee: Toyo Aluminium Kabushiki Kaisha (Nippon Light Metal Holdings Co., Ltd.)
• Inventors: Shingu, Akira, Egashira, Kiyoji
• Primary Examiner(s): Franklin, Jamara
• Application Number:
  US12/988,210
• Publication Number:
  US 20110036914A1
• Time in Patent Office: 1,281 Days
• Field of Search: 235/487, 235/492, 257/678, 257/679
• US Class Current: 235/492
• 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: H01Q 1/38 formed by a conductive layer on an insulating support patch antennas H01Q9/0407; microstrip dipole antennas H01Q9/065; microstrip slot antennas H01Q13/106; transmission line microstrip antennas H01Q13/206; manufacturing reflecting surfaces using insulating material for supporting the reflecting surface H01Q15/142
• CPC Class Codes: H01Q 7/00 Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop
• CPC Class Codes: H05K 1/162 incorporating printed capacitors
• CPC Class Codes: H05K 1/165 incorporating printed inductors
• CPC Class Codes: H05K 2201/0116 Porous, e.g. foam
• CPC Class Codes: H05K 2201/0355 Metal foils
• CPC Class Codes: H05K 2201/0382 Continuously deformed conductors
• CPC Class Codes: H05K 3/4685 Manufacturing of cross-over conductors

Abstract

Provided are an antenna circuit constituent body for an IC card/tag, which enhances a Q value by reducing a permittivity of a resin film of which a base material is made; and an IC card. The antenna circuit constituent body includes the base material made of resin film; and circuit pattern layers formed on each of both sides of the base material and made of aluminum foil. The circuit pattern layer includes a coiled pattern layer. Parts of the circuit pattern layers, which mutually face each other; and a part of the base material, which is interposed between the parts of the circuit pattern layers, constitute a capacitor. The circuit pattern layers are electrically connected by crimping parts. The base material includes a plurality of void-state-air layers. A relative density of the base material with respect to a density of a resin is less than or equal to 0.9.

Claims

1. An antenna circuit constituent body for an IC card/tag, comprising:

a base material made of a resin film;

a first circuit pattern layer formed on one of surfaces of the base material and made of an electrically conductive body including metal as a main component; and

a second circuit pattern layer formed on the other of the surfaces of the base material and made of an electrically conductive body including metal as a main component, wherein

at least either of the first circuit pattern layer and the second circuit pattern layer includes a coiled pattern layer,

a part of the first circuit pattern layer;

a part of the second circuit pattern layer, the part of the second circuit pattern layer facing the part of the first circuit pattern layer with the base material interposed; and

a part of the base material, the part of the base material interposed between the parts of the first circuit pattern layer and the second circuit pattern layer constitute a capacitor,

the first circuit pattern layer and the second circuit pattern layer are electrically connected so as to allow electrical continuity therebetween, and

the base material includes a plurality of void-state-air layers, a relative density of the base material with respect to a density of the resin is less than or equal to 0.9, an average volume of the void-state-air layers is greater than or equal to 2 μ

m³ and less than or equal to 90 μ

m³.

2. The antenna circuit constituent body for an IC card/tag, according to claim 1, wherein the resin film is made of polyethylene terephthalate.

3. The antenna circuit constituent body for an IC card/tag, according to claim 1, wherein the resin film is a biaxially-drawn film.

4. The antenna circuit constituent body for an IC card/tag, according to claim 1, wherein the first circuit pattern layer and the second circuit pattern layer are made of aluminum foil.

5. The antenna circuit constituent body for an IC card/tag, according to claim 1, wherein each of the first circuit pattern layer and the second circuit pattern layer and the base material are thermally bonded with each adhesive layer interposed therebetween, respectively.