JP2008236525A - Wireless ic device and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a wireless IC device in which an electromagnetic coupling module and a radiation plate are easily assembled and which is superior in radiation properties and is suitable for a RFID (radio frequency identification system), and to provide its manufacturing method. <P>SOLUTION: In the wireless IC device, an electromagnetic coupling module 1 comprising a power feed circuit board 10, on which a wireless IC chip 5 is mounted is stuck onto the surface of a board 20, and the rear face of the board 20 is stuck to a radiation plate 25. The power feed circuit board 10 includes a resonance circuit which has an inductance element and has a predetermined resonance frequency. The radiation plate 25 couples electromagnetically the power feeding circuit board 10 and transmits/receives a high-frequency signal. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a wireless IC device, and more particularly, to a wireless IC device having a wireless IC chip used in an RFID (Radio Frequency Identification) system and a manufacturing method thereof.

  In recent years, as an article management system, a reader / writer that generates an induction electromagnetic field and an IC chip (also referred to as an IC tag or a wireless IC chip) that stores predetermined information attached to an article or a container are communicated in a non-contact manner. RFID systems that transmit information have been developed. Conventionally, as described in Patent Documents 1 and 2, as a wireless IC device mounted with an IC chip, a radiation plate (antenna) is formed on a large-area film and the IC is brought into contact with the radiation plate. A chip was placed.

By the way, in the IC device, the radiation plate and the IC chip need to be superposed and placed in an electrically conductive state, and if the superposition is shifted, signal transmission / reception is hindered, so high accuracy is required for superposition. It had been. However, since the IC chip is very small (0.4 mm × 0.4 mm), it is difficult to handle, and it is extremely difficult to position it with high precision and mount it on the radiation plate. The resonance frequency characteristics change even with a slight misalignment. The problem was. In addition, since the radiation plate is small, there is a problem that radiation characteristics at the time of transmission and reception are not sufficient.
JP 2005-136528 A JP 2005-244778 A

  Accordingly, an object of the present invention is to provide a wireless IC device suitable for an RFID system and a method for manufacturing the same, in which an electromagnetic coupling module and a radiation plate can be easily assembled and radiation characteristics are good.

In order to achieve the above object, a wireless IC device according to the present invention comprises:
An electromagnetic coupling module comprising: a wireless IC chip; and a power supply circuit board on which the wireless IC chip is mounted and including a resonance circuit including an inductance element and having a predetermined resonance frequency;
A radiation plate electromagnetically coupled to the feeder circuit board;
A wireless IC device comprising:
A mount having a first main surface and a second main surface;
The mount on which the electromagnetic coupling module is attached to the first main surface side is attached to the radiation plate on the second main surface side;
It is characterized by.

  In the wireless IC device according to the present invention, an electromagnetic coupling module is configured by the wireless IC chip and the power supply circuit board, and the power supply circuit board and the radiation plate are electromagnetically coupled via a mount. Since the electromagnetic coupling module is attached to the radiation plate in a state of being attached to the mount, the handling of the electromagnetic coupling module is extremely easy. In addition, since the feeder circuit board and the radiation plate are electromagnetically coupled without being directly electrically connected, the electromagnetic coupling module operates even when provided close to the radiation plate. Further, it is not necessary to combine the electromagnetic coupling module with the radiation plate with high accuracy, and the mounting process is greatly simplified.

  The frequency of the transmission signal radiated from the radiation plate and the frequency of the reception signal supplied to the wireless IC chip are substantially determined by the resonance frequency of the resonance circuit in the power supply circuit board, and the radiation plate can adopt various shapes, and Since stable frequency characteristics can be obtained, radiation characteristics are good.

  In the wireless IC device according to the present invention, a metal plate may be provided on the first main surface or the second main surface of the mount, and this metal plate also functions as a radiator. The metal plate and the feeder circuit board may be directly opposed, or may be opposed via a mount. When the metal plate is provided on the first main surface of the mount, the radiation plate and the metal plate are capacitively coupled, and the metal plate functions as an antenna integrally with the radiation plate.

A method of manufacturing a wireless IC device according to the present invention includes:
An electromagnetic coupling module including a wireless IC chip and a power supply circuit board that includes the inductance element and includes a resonance circuit having a predetermined resonance frequency, the first main surface and the second main surface being mounted on the wireless IC chip. A step of adhering to the first main surface of the long mount having a predetermined interval;
Cutting the mount into blocks each including one electromagnetic coupling module;
Attaching the second main surface of the cut mount to the radiation plate;
It is provided with.

  The method of manufacturing a wireless IC device according to the present invention may further include a step of providing a metal plate at a predetermined interval on the first main surface or the second main surface of the long mount.

  The wireless IC chip may be rewritable and may have an information processing function other than the RFID system in addition to storing various types of information related to the article to which the electromagnetic coupling module is attached. .

  According to the present invention, assembly is easy without requiring high accuracy in joining the radiation plate and the electromagnetic coupling module. In addition, the feeder circuit board and the radiation plate are electromagnetically coupled, and the frequency is substantially determined by the resonance frequency of the resonance circuit in the feeder circuit board, and a stable frequency characteristic can be obtained. Various shapes can be adopted for the radiation plate, and a large gain can be obtained by increasing the shape of the radiation plate.

  Embodiments of a wireless IC device and a manufacturing method thereof according to the present invention will be described below with reference to the accompanying drawings. In each figure, common parts and portions are denoted by the same reference numerals, and redundant description is omitted.

(Refer 1st Example and FIGS. 1-6)
FIG. 1 shows a first embodiment of a wireless IC device. The wireless IC device includes an electromagnetic coupling module 1 including a wireless IC chip 5 and a power supply circuit board 10 on which the wireless IC chip 5 is mounted, a mount 20 and a radiation plate 25. The feeder circuit board 10 is attached to the surface of the mount 20 via an adhesive 18 (see FIG. 2), and the back surface of the mount 20 is attached to the radiation plate 25 via an adhesive 19.

  The mount 20 is made of paper, preferably a dielectric, and may be a resin film as long as it is a dielectric. The radiation plate 25 is obtained by providing a metal plating film such as an aluminum foil, a copper foil, Al, Cu, or Ag on a thin metal plate or a resin film made of a conductive material. The adhesives 18 and 19 are desirably insulating and have a high dielectric constant.

  As shown in detail in FIG. 2, the electromagnetic coupling module 1 includes a wireless IC chip 5 and a power supply circuit board 10 on which the wireless IC chip 5 is mounted. The wireless IC chip 5 includes a clock circuit, a logic circuit, a memory circuit, and the like, and stores necessary information. The wireless IC chip 5 is electrically connected to the resonance circuit 16 built in the power supply circuit board 10 via the metal bumps 6. ing. As a material for the metal bump 6, Au, solder, or the like can be used.

  The resonant circuit 16 selects a reception signal having a predetermined frequency from a circuit for supplying a transmission signal having a predetermined frequency to the radiation plate 25 and / or a signal received by the radiation plate 25, and the wireless IC chip 5. Is a circuit for supplying power to the power supply, and resonates at a predetermined frequency. As shown in FIGS. 2 and 3, the resonance circuit 16 is configured by a lumped constant LC series resonance circuit including a helical inductance element L and capacitance elements C1 and C2.

  Specifically, as shown in FIG. 4, the power supply circuit board 10 is obtained by laminating, pressing and firing ceramic sheets 11A to 11G made of a dielectric, and a sheet 11A in which a connection electrode 12 and a via-hole conductor 13a are formed, a capacitor Sheet 11B with electrode 14a, sheet 11C with capacitor electrode 14b and via-hole conductor 13b, sheet 11D with via-hole conductor 13c, sheet 11E with conductor pattern 15a and via-hole conductor 13d, sheet with via-hole conductor 13e 11F (one sheet or a plurality of sheets) and a sheet 11G on which a conductor pattern 15b is formed. Each of the ceramic sheets 11A to 11G may be a sheet made of a magnetic ceramic material, and the feeder circuit board 10 may be manufactured by a multilayer board manufacturing process such as a conventionally used sheet lamination method or thick film printing method. Can be easily obtained.

  By laminating the above sheets 11A to 11G, the inductance element L whose helical winding axis is parallel to the radiation plate 25, the capacitor electrode 14b is connected to both ends of the inductance element L, and the capacitor electrode 14a is a via hole. Capacitance elements C1 and C2 connected to the connection electrode 12 through the conductor 13a are formed. Then, the connection electrode 12 which is the substrate side electrode pattern is electrically connected to the terminal (see FIG. 5) of the wireless IC chip 5 through the metal bump 6.

  That is, among the elements constituting the resonance circuit, a transmission signal is fed from the inductance element L, which is a coiled electrode pattern, to the radiation plate 25 via a magnetic field, and the reception signal from the radiation plate 25 is a magnetic field. Power is supplied to the inductance element L. Therefore, it is desirable that the feeder circuit board 10 be laid out so that the inductance element L of the resonance circuit 16 and the capacitance elements C1 and C2 are close to the radiation plate 25.

  FIG. 5 shows a connection form between the wireless IC chip 5 and the power supply circuit board 10. In FIG. 5A, a pair of antenna (balance) terminals 7a and 17a are provided on the back surface of the wireless IC chip 5 and the front surface of the feeder circuit board 10, respectively. FIG. 5B shows another connection form. In addition to a pair of antenna (balance) terminals 7a and 17a, ground terminals 7b and 17b are provided on the back surface of the wireless IC chip 5 and the front surface of the feeder circuit board 10, respectively. It is provided. However, the ground terminal 17b of the power feeding circuit board 10 is terminated and is not connected to other elements of the power feeding circuit board 10.

  FIG. 3 shows an equivalent circuit of the electromagnetic coupling module 1. The electromagnetic coupling module 1 receives a high-frequency signal (for example, UHF frequency band) radiated from a reader / writer (not shown) by a radiation plate 25, and a resonance circuit 16 (inductance element) mainly magnetically coupled to the radiation plate 25. LC series resonance circuit comprising L and capacitance elements C1 and C2) is resonated, and only the received signal in a predetermined frequency band is supplied to the wireless IC chip 5. On the other hand, a predetermined energy is extracted from the received signal, information stored in the wireless IC chip 5 is matched with a predetermined frequency by the resonance circuit 16 using this energy as a driving source, and then the magnetic field is applied from the inductance element L. A transmission signal is transmitted to the radiation plate 25 through the coupling, and is transmitted and transferred from the radiation plate 25 to the reader / writer.

  Incidentally, the size of the wireless IC chip 5 is 0.4 to 0.9 mm × 0.4 to 0.9 mm, the thickness is 50 to 100 μm, and the size of the feeder circuit board 10 is 3 mm × larger than the size of the wireless IC chip 5. The thickness is about 200 to 500 μm up to about 3 mm. The sizes listed here are merely examples.

  The resonance circuit 16 and the radiation plate 25 are mainly coupled via a magnetic field, but may be coupled via an electric field. In the present invention, “electromagnetic field coupling” means coupling via an electric field and / or a magnetic field.

  In the resonance circuit 16, the resonance frequency characteristic is determined by a resonance circuit composed of an inductance element L and capacitance elements C1 and C2. The resonance frequency of the signal radiated from the radiation plate 25 is substantially determined by the self-resonance frequency of the resonance circuit 16. Therefore, the radiation plate 25 can be used in any shape, and the relative position of the electromagnetic coupling module 1 with respect to the radiation plate 25 is arbitrary. Therefore, it is not necessary to manage the attachment position of the electromagnetic coupling module 1 with high accuracy.

  Further, the coiled electrode pattern constituting the inductance element L has an advantage that the center frequency does not fluctuate because the winding axis is formed in parallel with the radiation plate 25. Further, since the capacitance elements C1 and C2 are inserted in the subsequent stage of the wireless IC chip 5, a low frequency surge can be cut by the elements C1 and C2, and the wireless IC chip 5 can be protected from the surge.

  By the way, the resonance circuit 16 also serves as a matching circuit for matching the impedance of the wireless IC chip 5 and the impedance of the radiation plate 25. The power supply circuit board 10 may include a matching circuit that is configured by an inductance element and a capacitance element and is provided separately from the resonance circuit 16. If an attempt is made to add a function of a matching circuit to the resonance circuit 16, the design of the resonance circuit 16 tends to be complicated. If a matching circuit is provided separately from the resonance circuit 16, the resonance circuit and the matching circuit can be designed independently.

  According to the first embodiment described above, since the frequency of the transmission / reception signal is substantially determined by the resonance frequency of the resonance circuit 16 of the power supply circuit board 10, high accuracy can be achieved in joining the radiation plate 25 and the electromagnetic coupling module 1. It is easy to assemble without being required. Moreover, since the electromagnetic coupling module 1 is attached to the radiation plate 25 in a state of being attached to the mount 20, the electromagnetic coupling module 1 is extremely easy to handle. Further, the electromagnetic coupling module 1 and the radiation plate 25 are electromagnetically coupled via the mount 20 and the adhesives 18 and 19, and the radiation plate 25 can adopt any shape, has good radiation characteristics and is stable. Frequency characteristics can be obtained.

  Here, a method of manufacturing the wireless IC device according to the first embodiment will be described. First, as shown in FIG. 6A, a long mount (taping film) 20 is prepared, and as shown in FIG. 6B, the power supply circuit board 10 on which the wireless IC chip 5 is mounted is mounted on the mount 20. Affix at a predetermined interval.

  Next, the mount 20 is cut along the dotted line a for each block including one electromagnetic coupling module 1 to obtain the electromagnetic coupling module 1 with a mount shown in FIG. After that, if the mount 20 is attached to the radiation plate 25 provided in the article used in the RFID system, the wireless IC device is completed.

(Refer to the second embodiment, FIGS. 7 and 8)
FIG. 7 shows a second embodiment of the wireless IC device. This wireless IC device includes the electromagnetic coupling module 1 including the power supply circuit board 10 on which the wireless IC chip 5 is mounted, as in the first embodiment, and a pair of metal plates 26 and 26 are provided on the surface of the mount 20. Is provided, and the power supply circuit board 10 is attached with the metal plates 26 and 26 interposed therebetween. Furthermore, the back surface of the mount 20 is stuck on the radiation plate 25 with an insulating and high dielectric constant adhesive. The material of the mount 20 and the radiation plate 25 is the same as that of the first embodiment, and an adhesive having an insulating property and a high dielectric constant is used for each sticking.

  In the second embodiment, the radiation plate 25 and the metal plates 26 and 26 are capacitively coupled, and the metal plates 26 and 26 function integrally with the radiation plate 25 as an antenna for a high frequency signal. Therefore, the operational effects of the second embodiment are the same as those of the first embodiment.

  Here, a method of manufacturing the wireless IC device according to the second embodiment will be described. First, as shown in FIG. 8A, metal plates 26 are provided on a long mount (taping film) 20 at predetermined intervals. The metal plates 26 and 26 may be metal thin films made of a conductive material, or may be metal plating films such as aluminum foil, copper foil, and Al.

  Next, as shown in FIG. 8B, the power supply circuit board 10 on which the wireless IC chip 5 is mounted is pasted on the surface of the mount 20 across the pair of metal plates 26 and 26. Thereafter, the mount 20 is cut along a dotted line a for each block including one electromagnetic coupling module 1 to obtain a wireless IC device shown in FIG. 8C, and the mount 20 is attached onto the radiation plate 25.

  In the second embodiment, a pair of metal plates 26 are not necessarily required for one electromagnetic coupling module 1 and may be one. Further, as shown in FIG. 9, the electromagnetic coupling module 1 may be attached to the front surface of the mount 20, and the metal plates 26 and 26 may be provided on the back surface of the mount 20. The mount 20 is attached to the radiation plate 25 with an insulating and high dielectric constant adhesive with the metal plates 26 sandwiched therebetween. In this case, the metal plates 26 and 26 are also electromagnetically coupled via the feeder circuit board 10 and the mount 20 in the same manner as the radiation plate 25.

(Other examples)
The wireless IC device and the manufacturing method thereof according to the present invention are not limited to the above-described embodiments, and can be variously modified within the scope of the gist.

  In particular, in each embodiment, the details of the internal configuration of the feeder circuit board and the details of the radiation plate are arbitrary, and the feeder circuit board may be formed of a flexible material. Furthermore, processing other than metal bumps may be used to connect the wireless IC chip on the power supply circuit board.

1 shows a first embodiment of a wireless IC device according to the present invention, wherein (A) is a plan view and (B) is an XX cross-sectional view. It is sectional drawing which shows an electromagnetic coupling module. It is an equivalent circuit diagram of an electromagnetic coupling module. It is a disassembled perspective view which shows a feeder circuit board. (A), (B) is a perspective view which shows the connection state of a radio | wireless IC chip and a feeder circuit board. It is explanatory drawing which shows the manufacturing process of 1st Example. The 2nd Example of the radio | wireless IC device which concerns on this invention is shown, (A) is a top view, (B) is YY sectional drawing. It is explanatory drawing which shows the manufacturing process of 2nd Example. It is sectional drawing which shows the modification of 2nd Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Electromagnetic coupling module 5 ... Wireless IC chip 10 ... Feeding circuit board 16 ... Resonance circuit 20 ... Mount 25 ... Radiation plate 26 ... Metal plate L ... Inductance element

Claims (5)

An electromagnetic coupling module comprising: a wireless IC chip; and a power supply circuit board on which the wireless IC chip is mounted and including a resonance circuit including an inductance element and having a predetermined resonance frequency;
A radiation plate electromagnetically coupled to the feeder circuit board;
A wireless IC device comprising:
A mount having a first main surface and a second main surface;
The mount on which the electromagnetic coupling module is attached to the first main surface side is attached to the radiation plate on the second main surface side;
A wireless IC device characterized by the above.   The wireless IC device according to claim 1, wherein a metal plate is provided on the first main surface or the second main surface of the mount.   The wireless IC device according to claim 2, wherein the metal plate is provided on a first main surface of the mount, and the metal plate and the radiation plate are capacitively coupled. An electromagnetic coupling module including a wireless IC chip and a power supply circuit board that includes the inductance element and includes a resonance circuit having a predetermined resonance frequency, the first main surface and the second main surface being mounted on the wireless IC chip. A step of adhering to the first main surface of the long mount having a predetermined interval;
Cutting the mount into blocks each including one electromagnetic coupling module;
Attaching the second main surface of the cut mount to the radiation plate;
A method of manufacturing a wireless IC device, comprising:   5. The method of manufacturing a wireless IC device according to claim 4, further comprising a step of providing a metal plate at a predetermined interval on the first main surface or the second main surface of the elongated mount.

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