WIRELESS IC DEVICE

• US 20100314455A1
• Filed: 08/20/2010
• Published: 12/16/2010
• Est. Priority Date: 03/26/2008
• Status: Active Grant

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: KATO, Noboru, ISHINO, Satoshi
• Granted Patent: US 8,668,151 B2
• Time in Patent Office: Days
• US Class Current: 235/492
• CPC Class Codes: H01F 17/0013 with stacked layers
• CPC Class Codes: H01L 2224/0401 Bonding areas specifically adapted for bump connectors, e.g. under bump metallisation [UBM]
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• 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 2924/00012 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 2924/15174 in different layers of the multilayer substrate
• CPC Class Codes: H01L 2924/181 Encapsulation
• 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 1/2283 mounted in or on the surface of a semiconductor substrate as a chip-type antenna or integrated with other components into an IC package
• CPC Class Codes: H01Q 1/50 Structural association of antennas with earthing switches, lead-in devices or lightning protectors
• CPC Class Codes: H01Q 21/29 Combinations of different interacting antenna units for giving a desired directional characteristic H01Q25/00 takes precedence
• 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 1/0239 Signal transmission by AC coupling
• CPC Class Codes: H05K 1/0243 Printed circuits associated with mounted high frequency components
• CPC Class Codes: H05K 2201/10098 Components for radio transmission, e.g. radio frequency identification [RFID] tag, printed or non-printed antennas
• CPC Class Codes: H05K 2201/10727 Leadless chip carrier [LCC], e.g. chip-modules for cards
• CPC Class Codes: H05K 3/305 Affixing by adhesive

Abstract

A wireless IC device improves radiation characteristics or directivity of signals and reliably communicates with a reader/writer. The wireless IC device includes an electromagnetically coupled module includes a wireless IC device and a feed circuit substrate, a protective layer, a first radiation plate, and a second radiation plate. The feed circuit substrate includes a feed circuit including inductance elements. The feed circuit is electrically connected to the wireless IC chip and coupled to the radiation plates. Signals received by the radiation plates are provided to the wireless IC chip via the feed circuit. Signals from the wireless IC chip are provided to the radiation plates via the feed circuit and then radiated to the outside.

Claims

1. A wireless IC device comprising:

a wireless IC device;

a feed circuit substrate that is coupled to the wireless IC and includes a feed circuit including a resonant circuit and/or a matching circuit, the resonant circuit and/or the matching circuit including at least one inductance element;

first and second radiation plates arranged to radiate a transmission signal provided from the feed circuit and/or provide a received signal to the feed circuit; and

a protective layer or a metal case covering the wireless IC device and provided on one main surface of the feed circuit substrate;

wherein

the first radiation plate is an electrode disposed on the protective layer or the metal case, and the second radiation plate is disposed on another main surface of the feed circuit substrate.

2. The wireless IC device according to claim 1, wherein the feed circuit is electromagnetically coupled to the second radiation plate and matches an inductance of the wireless IC chip and inductances of the first and second radiation plates.

3. The wireless IC device according to claim 1, wherein a resonant frequency of signals radiated from the first and second radiation plates is substantially equivalent to a self-resonant frequency of the feed circuit.

4. The wireless IC device according to claim 1, wherein the feed circuit includes at least two inductance elements that have different inductance values and that are coupled to each other.

5. The wireless IC device according to claim 1, wherein the first radiation plate is disposed on a surface of the protective layer or inside the protective layer.

6. The wireless IC device according to claim 1, wherein the second radiation plate is disposed on a surface of a print substrate or inside the print substrate.

7. The wireless IC device according to claim 1, wherein the first radiation plate is an inverted-F antenna or an inverted-L antenna.

8. The wireless IC device according to claim 1, wherein a mounting external electrode is disposed on the other main surface of the feed circuit substrate.