IC-tag-bearing wiring board and method of fabricating the same

• US 20060001138A1
• Filed: 02/18/2005
• Published: 01/05/2006
• Est. Priority Date: 06/30/2004
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Sakama, Isao, Ashizawa, Minoru
• Granted Patent: US 7,586,446 B2
• Time in Patent Office: Days
• US Class Current: 257/678
• 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 19/24 the primary active element being centre-fed and substantially straight, e.g. H-antenna
• CPC Class Codes: H01Q 9/285 Planar dipole H01Q9/065 takes precedence; patch antenna H01Q9/0407
• CPC Class Codes: H05K 1/0266 Marks, test patterns or identification means
• CPC Class Codes: H05K 1/16 incorporating printed electric components, e.g. printed resistor, capacitor, inductor
• CPC Class Codes: H05K 1/184 Components including terminals inserted in holes through the printed circuit board and connected to printed contacts on the walls of the holes or at the edges thereof or protruding over or into the holes
• 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 2201/10446 Mounted on an edge soldering edge mounted components H05K3/3405; edge terminals H05K2201/1034
• CPC Class Codes: H05K 2201/10651 Component having two leads, e.g. resistor, capacitor
• CPC Class Codes: H05K 3/403 Edge contacts; Windows or holes in the substrate having plural connections on the walls thereof H05K3/4092 takes precedence

Abstract

To improve electronic part packaging efficiency without sacrificing the transmission distance of a radio IC tag, a recess is formed in the front side surface of a printed wiring board. An IC chip is placed in the recess so that the IC chip does not protrude from the front side surface, a first major surface 1a and a second major surface of the printed wiring board. Antenna elements of an antenna are formed on the front side surface on the opposite sides, respectively, of the IC chip, and the antenna is connected to the IC chip. The antenna is a dipole antenna of a length equal to half the wavelength of radio waves to be radiated by the antenna.

Claims

1. An IC tag-bearing printed circuit wiring board comprising:

a radio IC (integrated circuit) tag and an antenna coupled to the IC tag, the IC tag having stored thereon information to be transmitted, the antenna serving to radiate radio waves representative of the stored information to be transmitted, the antenna being disposed on the surface of an edge of the printed circuit wiring board, the edge connecting a first major surface of the printed circuit wiring board and a second major surface of the printed circuit wiring board; and

a recess formed in the edge of the printed circuit wiring board, the IC chip being disposed in the recess and being flush with or disposed below the surface of the edge of the printed circuit wiring board.

2. The IC tag-bearing wiring board of claim 1 wherein the antenna is a dipole antenna having a length equal to about one half the nominal wavelength of the radio waves to be radiated.

3. The IC tag-bearing wiring board of claim 1 wherein the antenna includes a portion that extends at least partially to and is disposed on the first major surface or to the second major surface.

4. The IC tag-bearing wiring board of claim 1 wherein the antenna includes segments disposed on the opposite sides of the IC chip, each segment being connected to the IC chip by dc short-circuiting.

11. A method of fabricating the IC tag-bearing wiring board of claim 1 comprising:

forming a slotted opening on a workpiece, the slotted opening having a long axis;

forming a layer of conductive material on the edge surfaces of the slotted opening,

cutting the workpiece along a line that is parallel to the long axis and located within the slotted opening, thus dividing the workpiece into first and second boards;

forming a recess on the edge of the first board in the region of the slotted opening, thereby dividing the conductive layer in the slotted region into first and second segments;

disposing the IC tag in the recess; and

providing an electrical connection between the IC tag and each of the segments, the segments thereby serving as the antenna.

12. The method of claim 11 wherein the first and second segments are adjusted depending on the wavelength of the radio waves.

5. An IC tag-bearing printed circuit wiring board comprising:

a radio IC (integrated circuit) tag and an antenna coupled to the IC tag, the IC tag having stored thereon information to be transmitted, the antenna serving to radiate radio waves representative of the stored information to be transmitted, the antenna being disposed on the surface of an edge of the printed circuit wiring board, the edge connecting a first major surface of the printed circuit wiring board and a second major surface of the printed circuit wiring board; and

an auxiliary antenna disposed on the first major surface or the second major surface, wherein the radiated radio waves are directed based on position of the auxiliary antenna relative to the antenna.

6. The IC tag-bearing wiring board of claim 5 wherein the auxiliary antenna has a length dependent on the wavelength of the radiated radio waves.

7. An IC tag-bearing wiring board comprising an IC tag having information stored thereon and a dipole antenna for radiating radio waves representing the stored information,

the antenna being disposed on the surface of an edge of the wiring board, the antenna having a length equal to about one half the nominal wavelength of radio waves to be radiated, a central region of the antenna having a slit formed therethrough, thereby defining a first terminus and a second terminus,

the first terminus including a first terminal that extends to and is disposed on a first major surface of the wiring board,

the second terminus including a second terminal that extends to and is disposed on the first major surface of the wiring board proximate the first terminal,

the IC tag straddling the first and second terminals and contacting the first and second terminals.

8. An IC tag-bearing wiring board comprising an IC tag having information stored thereon and an antenna for radiating radio waves representing the stored information,

the IC tag having a first terminal and a second terminal,

the antenna being disposed on the surface of an edge of the wiring board, the edge connecting a first major surface of the wiring board to a second major surface of the wiring board, the antenna having a length equal to about a quarter of the nominal wavelength of the radio waves to be transmitted,

the IC tag being mounted on the first or the second major surface proximate the antenna,

the antenna connected to the first terminal of the IC tag,

the wiring board having a ground, the second terminal of the IC tag being connected to the ground.

9. The IC tag-bearing wiring board of claim 8 wherein the ground is a ground plane disposed in the wiring board.

10. The IC tag-bearing wiring board of claim 8 wherein the ground is a ground plane disposed on the first major surface or the second major surface of the wiring board.