WIRELESS IC DEVICE

• US 20080143630A1
• Filed: 03/05/2008
• Published: 06/19/2008
• Est. Priority Date: 04/14/2006
• Status: Active Grant

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: KATO, Noboru, ISHINO, Satoshi
• Granted Patent: US 7,518,558 B2
• Time in Patent Office: Days
• US Class Current: 343/795
• 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 2224/16225 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: 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: 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 1/50 Structural association of antennas with earthing switches, lead-in devices or lightning protectors
• CPC Class Codes: H01Q 9/285 Planar dipole H01Q9/065 takes precedence; patch antenna H01Q9/0407

Abstract

A wireless IC device includes a flexible sheet provided with a wireless IC chip and radiation plates. The wireless IC chip is connected by an Au bump to a feeder circuit which is located on the sheet and which has a predetermined resonant frequency and a predetermined impedance. The feeder circuit includes electrode patterns, and the feeder circuit and the radiation plates are capacitively coupled with each other through the flexible sheet.

Claims

1. A wireless IC device comprising:

a flexible sheet including a wireless IC chip, radiation plates, and a feeder circuit provided thereon;

wherein

the feeder circuit has a predetermined resonant frequency and a predetermined impedance;

the wireless IC chip is connected to the feeder circuit; and

the feeder circuit and the radiation plates are coupled with each other.

2. The wireless IC device according to claim 1, wherein the feeder circuit includes an electrode pattern, and a cutout arranged to adjust the resonant frequency and the impedance is provided in the electrode pattern of the feeder circuit.

3. The wireless IC device according to claim 1, wherein the radiation plates are defined by flexible metal films on the flexible sheet.

4. The wireless IC device according to claim 1, wherein

the wireless IC chip and the feeder circuit are provided on a first main surface of the flexible sheet, and the radiation plates are provided on a second main surface of the flexible sheet opposite to the first main surface;

and

the feeder circuit and the radiation plates are capacitively coupled with each other through the flexible sheet.

5. The wireless IC device according to claim 1, wherein

the flexible sheet includes a flexible first sheet and a flexible second sheet;

the wireless IC chip and the feeder circuit are provided on a first main surface of the flexible first sheet, and the radiation plates are provided on a first main surface of the flexible second sheet; and

the flexible first and second sheets are bonded to each other so that the first main surface of the flexible first sheet and the first main surface of the flexible second sheet oppose each other, and the feeder circuit and the radiation plates are coupled with each other.

6. The wireless IC device according to claim 5, wherein the feeder circuit and the radiation plates are directly electrically coupled with each other.

7. The wireless IC device according to claim 5, wherein the feeder circuit and the radiation plates are capacitively coupled with each other through an adhesive layer disposed between the flexible first and second sheets.

8. The wireless IC device according to claim 1, wherein

the flexible sheet includes a flexible first sheet and a flexible second sheet;

the wireless IC chip and the feeder circuit are provided on a first main surface of the flexible first sheet, and the radiation plates are provided on a first main surface of the flexible second sheet, and

the flexible first and second sheets are bonded to each other so that the first main surface of the flexible first sheet and a second main surface opposite to the first main surface of the flexible second sheet oppose each other, and the feeder circuit and the radiation plates are capacitively coupled with each other through the flexible second sheet.

9. The wireless IC device according to claim 1, wherein the wireless IC chip is connected to the feeder circuit via at least one Au bump.