JP5098478B2 - Wireless IC device and manufacturing method thereof - Google Patents

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.

  Patent Document 1 describes an IC card including an IC and an antenna. In this IC card, an antenna is formed by screen-printing conductive ink on a plastic film, and the IC is mounted on the antenna using an anisotropic conductive film.

However, in this IC card, it is necessary to mount the IC so as to be conductive between the conductor forming the antenna and the other conductor formed so as to surround the conductor, and high mounting accuracy is required. Further, since the IC is bonded with an anisotropic conductive film after the conductive ink serving as the antenna is dried and cured, it takes time to manufacture and the cost of the IC card increases. Furthermore, since the IC is only mounted on the antenna, there is a problem that the IC is dropped or damaged when an impact is applied to the card.
JP-A-8-216571

  Accordingly, an object of the present invention is to provide a wireless IC device which can be mounted on a substrate with a small number of steps and can be manufactured at low cost, and a method for manufacturing the same.

In order to achieve the above object , the wireless IC device according to the first aspect is:
A wireless IC chip for processing transmission and reception signals;
Including an inductance element, a power supply circuit board that said inductance element is connected to the wireless IC chip,
A radiation plate arranged to be coupled to the inductance element;
A base material provided with the radiation plate;
With
Configure the module by mounting the wireless IC chip on the feeder circuit board,
Said motor at least a portion of the Joule is embedded in the radiation plate,
The upper surface and the back surface of the feeder circuit board and at least one side surface are in contact with the radiation plate;
It is characterized by.
The wireless IC device which is the second form is
A wireless IC chip for processing transmission and reception signals;
A feeder circuit board including an inductance element, the inductance element being connected to the wireless IC chip;
A radiation plate arranged to be coupled to the inductance element;
A base material provided with the radiation plate;
With
The wireless IC chip is mounted on the power supply circuit board to constitute a module,
At least a portion of the module is embedded in the radiation plate;
A resonance circuit and / or a matching circuit is formed on the power supply circuit board,
A plurality of the radiation plates are arranged at a predetermined interval,
The resonance circuit and / or the matching circuit of the feeder circuit board are arranged to be electromagnetically coupled to the plurality of radiation plates;
It is characterized by.

Wherein in the wireless IC device, is operated continuously line IC chip by the received signal in the radiation plate, the response signal from the wireless IC chip is radiated to the outside from the discharge morphism plate. Since module that at least a portion is embedded in the radiation plate, becomes tight coupling between the feeder circuit board and the radiation plate, mechanical fixing strength is improved and radiation characteristics, impact resistance is improved. Further, it is possible to implement the module while maintaining the viscosity before the radiation plate is cured, the mounting step of the forming process and modules of the radiation plate can be carried out simultaneously, the manufacturing process is reduced, a low-cost Can be manufactured. Moreover, not the distance tolerance serious problem of the radiation plate and the module may be a substantially constant coupling between the radiating plate and the inductance element.

Further, in the above wireless IC device, since constituting the module by mounting the wireless IC chip on the feeder circuit board can be easily mounted a small wireless IC device in a small feeder circuit board . When the wireless IC chip is changed in accordance with the operating frequency of the RFID system, it is only necessary to change the design of the resonance circuit and / or the matching circuit of the power supply circuit board. It is not necessary to change the coupling state with the power supply circuit board.

In the wireless IC device according to the first embodiment, since the upper surface, the rear surface, and at least one side surface of the power supply circuit board are in contact with the radiation plate, the coupling degree between the radiation plate and the resonance circuit and / or the matching circuit is improved. To do .

  The radiation plate may be directly joined to the surface of the power supply circuit board. However, an external electrode that electromagnetically couples to the resonance circuit and / or the matching circuit is formed on the surface of the power supply circuit board, and the external electrode is connected to the radiation plate. It is preferable to be electrically connected. Since the external electrode and the radiation plate are connections between metals, the bonding strength is improved. It is preferable that the wireless IC chip and / or the power supply circuit substrate is covered with a protective film. Environmental resistance is improved.

Further, in the wireless IC device according to the second embodiment, the plurality of radiation plates are arranged with a predetermined interval, and the resonance circuit and / or the matching circuit of the feeder circuit board are electromagnetically coupled to the plurality of radiation plates. that it has been placed in. By providing a plurality of radiation plates and electromagnetically coupling the resonance circuit and / or the matching circuit, radiation characteristics and directivity are improved.

  The power supply circuit board may be formed of a multilayer board made of a resin such as ceramic or liquid crystal polymer. If the multilayer substrate is used, an inductance element and a capacitance element can be incorporated with high accuracy, and the degree of freedom in forming electrodes is improved.

  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 wireless IC device is attached. .

The manufacturing method of the wireless IC device which is the third form is as follows.
Preparing a base material for forming the radiation plate;
A step of the feeder circuit board including an inductance element, equipped with a wireless IC chip that processes transmission and reception signals in a connected state with the inductance element to form a module,
Forming a radiation plate with a viscous conductive material on the substrate;
A step of mounting the module to at least one side surface and the upper surface and the back surface of the feeder circuit board is embedded in the radiation plate,
Curing the conductive material;
It is provided with.
A method for manufacturing a wireless IC device according to the fourth embodiment is as follows.
Preparing a base material for forming the radiation plate;
Mounting a wireless IC chip for processing transmission / reception signals in a connected state with the inductance element on a power supply circuit board including the inductance element, and configuring a module;
Forming a radiation plate with a viscous conductive material on the substrate;
Mounting the module such that at least a portion of the module is embedded in the radiation plate;
Curing the conductive material;
A method of manufacturing a wireless IC device comprising:
A resonance circuit and / or a matching circuit is formed on the power supply circuit board,
A plurality of the radiation plates are arranged at a predetermined interval,
The resonance circuit and / or the matching circuit of the feeder circuit board are arranged to be electromagnetically coupled to the plurality of radiation plates;
It is characterized by.

According to the manufacturing method, the viscosity can implement the module by embedding a module into the radiation plate formed on a substrate by a conductive material having a manufacturing process can be simplified, the cost Can be planned. Further, the coupling between the feeder circuit board and the radiation plate becomes dense, the radiation characteristics and the fixing strength are improved, and the variation in the coupling degree is reduced.

According to the present invention, can simplify the manufacturing process, it is possible to reduce the cost, the coupling between the feeder circuit board and the radiation plate can be tightly, also reduced variation in coupling degree, and the module Bonding strength with the radiation plate is also improved. In addition, since the power supply circuit board is configured in a small size, even a small wireless IC chip can be easily mounted on the power supply circuit board using a conventional mounting machine, and the mounting cost is reduced. Moreover, when changing the used frequency band, it is only necessary to change the design of the resonant circuit and / or the matching circuit.

  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.

(Electromagnetic coupling module, see FIGS. 1 and 2)
First, an electromagnetic coupling module constituting a wireless IC device according to the present invention will be described with reference to FIG. 1 and FIG. As shown in FIGS. 1A, 1B, and 1C, the electromagnetic coupling module 1 includes a wireless IC chip 5 that processes transmission / reception signals of a predetermined frequency, and a power supply circuit board 10 on which the wireless IC chip 5 is mounted. It consists of.

  The wireless IC chip 5 includes a clock circuit, a logic circuit, a memory circuit, and the like, and stores necessary information. As shown in FIG. 2, input / output terminal electrodes 6, 6 and mounting terminal electrodes 7, 7 is provided. The input / output terminal electrodes 6 and 6 are electrically connected to the electrodes 12a and 12b (see FIG. 8) provided on the surface of the feeder circuit board 10 via the metal bumps 8. Further, the mounting terminal electrodes 7 and 7 are electrically connected to the electrodes 12c and 12d through the metal bumps 8. As a material for the metal bump 8, Au, solder, or the like can be used.

  A protective film 9 is provided between the front surface of the power supply circuit board 10 and the back surface of the wireless IC chip 5.

  The feeder circuit board 10 has a built-in resonance circuit (not shown in FIG. 1) having an inductance element, and connection electrodes 12a to 12d (FIG. 8) are formed on the surface. In the module 1 shown in FIG. 1A, the resonance circuit is electromagnetically coupled to the radiation plates 21a and 21b (see FIG. 3) disposed on the surface of the feeder circuit board 10.

  In the module 1 shown in FIG. 1B, the external electrodes 19a and 19b provided on the back surface of the power supply circuit board 10 are electromagnetically coupled to the resonance circuit. In the module 1, the radiation plates 21a and 21b (see FIG. 3) are electrically connected to the external electrodes 19a and 19b through a conductive adhesive, solder, or the like. The external electrodes 19a and 19b may be formed from the back surface of the substrate 10 to both sides and further to the top surface.

  The module 1 shown in FIG. 1C is provided with a protective film 23 made of resin such as epoxy or polyimide covering the wireless IC chip 5 on the surface of the power supply circuit board 10. By providing the protective film, the environmental resistance is improved.

  The power supply circuit board 10 includes a resonance circuit having a predetermined resonance frequency, and a transmission signal having a predetermined frequency transmitted from the wireless IC chip 5 is transmitted via the external electrodes 19a and 19b or directly. A reception signal having a predetermined frequency is selected from signals transmitted to the radiation plates 21a and 21b (see FIG. 3) and received by the radiation plates 21a and 21b, and supplied to the wireless IC chip 5. Therefore, in this wireless IC device, the wireless IC chip 5 is operated by signals received by the radiation plates 21a and 21b, and a response signal from the wireless IC chip 5 is radiated to the outside from the radiation plates 21a and 21b.

  Further, when the external electrodes 19a and 19b are provided, the external electrodes 19a and 19b and the radiation plates 21a and 21b are metal-to-metal connections, so that the bonding strength is improved.

(Refer to the first embodiment, FIGS. 3 and 4)
FIG. 3 shows a first embodiment of a wireless IC device according to the present invention. In this wireless IC device, the radiation plates 21a and 21b are provided on the surface of a base material 50 such as a resin film by applying a conductive paste having viscosity, and the electromagnetic coupling module 1 is configured such that the conductive paste has viscosity. While being held, the side surface from the back surface of the feeder circuit board 10 is embedded in the conductive paste.

The wireless IC device according to the first embodiment is manufactured by the following steps shown in FIG.
(1) The process of preparing the base material 50 (refer FIG. 4 (A)).
(2) A step of configuring the electromagnetic coupling module 1 by mounting the wireless IC chip 5 on the power supply circuit board 10 in an electrically conductive state with a resonance circuit built in the board 10.
(3) A step of forming (applying) the radiation plates 21a and 21b with a conductive material having viscosity on the substrate 50 (see FIG. 4B).
(4) A step of mounting the electromagnetic coupling module 1 so that approximately 2/3 of the power supply circuit board 10 is embedded in the radiation plates 21a and 21b (see FIG. 4C).
(5) A step of curing the conductive material.

  In the above manufacturing method, the formation of the radiation plates 21a and 21b and the mounting of the electromagnetic coupling module 1 are performed simultaneously. Therefore, the manufacturing process is simplified, and manufacturing at low cost becomes possible. Even if the accuracy of embedding the electromagnetic coupling module 1 is not so high, the radiation plate and the resonance circuit can be electromagnetically coupled to each other with a predetermined value, and the radiation characteristics are good. In addition, the bonding strength between the power supply circuit board 10 and the radiation plates 21a and 21b is high, and the impact resistance of the electromagnetic coupling module 1 is improved.

(Refer to the second embodiment, FIG. 5)
FIG. 5 shows a second embodiment of the wireless IC device according to the present invention. The wireless IC device extends from the back surface to the side surface and the top surface of the power supply circuit board 10, in other words, the electromagnetic coupling module in a state where the wireless IC chip 5 other than the wireless IC chip 5 is brought into contact with the radiation plates 21a and 21b and embedded in the radiation plates 21a and 21b. 1 is mounted on a substrate 50. The coupling between the radiation plates 21a and 21b and the resonance circuit is increased, and the mechanical bonding strength is also improved.

(Refer to the third embodiment, FIG. 6)
FIG. 6 shows a third embodiment of the wireless IC device according to the present invention. As shown in FIG. 1C, this wireless IC device uses the electromagnetic coupling module 1 in which the wireless IC chip 5 and the power feeding circuit board 10 are covered with a protective film 23. In the third embodiment, the radiation plates 21 a and 21 b are also in contact with the upper surface of the electromagnetic coupling module 1.

(Refer to the fourth embodiment, FIG. 7)
FIG. 7 shows a fourth embodiment of the wireless IC device according to the present invention. As in the third embodiment, this wireless IC device uses the electromagnetic coupling module 1 provided with the protective film 23, and the radiation plates 21 a and 21 b are in contact with the entire upper surface of the electromagnetic coupling module 1.

(An example of a resonant circuit, see FIG. 8)
An example of the resonance circuit built in the feeder circuit board 10 is shown in FIG. This power supply circuit board 10 is obtained by laminating, pressing and firing ceramic sheets 11A to 11H made of a dielectric, and connection electrodes 12a and 12b, electrodes 12c and 12d, and via-hole conductors 13a and 13b are formed on the sheet 11A. The sheet 11B is formed with capacitor electrodes 18a, conductor patterns 15a and 15b, and via-hole conductors 13c to 13e, and the sheet 11C is formed with capacitor electrodes 18b and via-hole conductors 13d to 13f. Furthermore, conductor patterns 16a and 16b and via-hole conductors 13e, 13f, 14a, 14b, and 14d are formed on the sheet 11D, and conductor patterns 16a and 16b and via-hole conductors 13e, 13f, 14a, 14c, and 14e are formed on the sheet 11E. Then, the capacitor electrode 17, conductor patterns 16a and 16b, and via-hole conductors 13e, 13f, 14f, and 14g are formed on the sheet 11F, and the conductor patterns 16a and 16b and the via-hole conductors 13e, 13f, 14f, and 14g are formed on the sheet 11G. In the sheet 11H, conductor patterns 16a and 16b and via-hole conductors 13f are formed.

  By laminating the above sheets 11A to 11H, the inductance element L1 is configured by the conductor pattern 16a spirally connected by the via-hole conductors 14c, 14d, and 14g, and spiral by the via-hole conductors 14b, 14e, and 14f. An inductance element L2 is configured by the conductor pattern 16b connected to the capacitor element, a capacitance element C1 is configured by the capacitor electrodes 18a and 18b, and a capacitance element C2 is configured by the capacitor electrodes 18b and 17.

  One end of the inductance element L1 is connected to the capacitor electrode 18b via the via-hole conductors 14c and 13d, the conductor pattern 15a, and the via-hole conductor 13c, and one end of the inductance element L2 is connected to the capacitor electrode 17 via the via-hole conductor 14a. The other ends of the inductance elements L1 and L2 are combined together on the sheet 11H and connected to the connection electrode 12a via the via-hole conductor 13e, the conductor pattern 15b, and the via-hole conductor 13a. Further, the capacitor electrode 18a is electrically connected to the connection electrode 12b through the via-hole conductor 13b.

  The connection electrodes 12a and 12b are electrically connected to the terminal electrodes 6 and 6 (see FIG. 2) of the wireless IC chip 5 through the metal bumps 8 (see FIG. 1). The electrodes 12 c and 12 d are connected to the terminal electrodes 7 and 7 of the wireless IC chip 5.

  Further, external electrodes 19a and 19b are provided on the back surface of the power supply circuit board 10 by applying a conductive paste, the external electrode 19a is coupled to the inductance elements L (L1 and L2) by an electromagnetic field, and the external electrode 19b is a via-hole conductor. It is electrically connected to the capacitor electrode 18b through 13f.

  In this resonance circuit, the inductance elements L1 and L2 have a structure in which two conductor patterns 16a and 16b are arranged in parallel. The two conductor patterns 16a and 16b have different line lengths, can have different resonance frequencies, and can widen the band of the wireless IC device.

  Each of the ceramic sheets 11A to 11H may be a sheet made of a magnetic ceramic material, and the feeder circuit board 10 may be manufactured by a multilayer substrate manufacturing process such as a conventionally used sheet lamination method or thick film printing method. Can be easily obtained.

  Further, the sheets 11A to 11H are formed as a flexible sheet made of a dielectric material such as polyimide or liquid crystal polymer, and electrodes and conductors are formed on the sheet by a thick film forming method, and the sheets are laminated. Then, a laminated body may be formed by thermocompression bonding or the like, and inductance elements L1 and L2 and capacitance elements C1 and C2 may be incorporated.

  In the feeder circuit board 10, the inductance elements L1, L2 and the capacitance elements C1, C2 are provided at different positions in plan view, and the inductance elements L1, L2 are magnetically coupled to the external electrode 19a (radiating plate 21a), The capacitance elements C1 and C2 are electrically connected to the external electrode 19b (radiating plate 29b).

  Therefore, the electromagnetic coupling module 1 in which the wireless IC chip 5 is mounted on the power supply circuit board 10 receives a high-frequency signal (for example, UHF frequency band) radiated from a reader / writer (not shown) by the radiation plates 21a and 21b. A resonance circuit that is magnetically coupled and electric field coupled to the electrodes 19 a and 19 b is resonated, and only a reception signal in a predetermined frequency band is supplied to the wireless IC chip 5. On the other hand, a predetermined energy is extracted from this received signal, and information stored in the wireless IC chip 5 is matched with a predetermined frequency by a resonance circuit using this energy as a drive source, and then passed through the external electrodes 19a and 19b. Is transmitted to the radiation plates 21a and 21b, and transmitted and transferred from the radiation plates 21a and 21b to the reader / writer.

  In the feeder circuit board 10, the resonance frequency characteristic is determined by a resonance circuit composed of inductance elements L 1 and L 2 and capacitance elements C 1 and C 2. The resonance frequency of the signal radiated from the radiation plates 21a and 21b is substantially determined by the self-resonance frequency of the resonance circuit.

  Incidentally, the resonance circuit also serves as a matching circuit for matching the impedance of the wireless IC chip 5 and the impedance of the radiation plates 21a and 21b. The power feeding circuit board 10 may include a matching circuit provided separately from a resonance circuit composed of an inductance element and a capacitance element (in this sense, the resonance circuit is also referred to as a matching circuit). If an attempt is made to add a function of a matching circuit to the resonance circuit, the design of the resonance circuit tends to be complicated. If a matching circuit is provided separately from the resonance circuit, the resonance circuit and the matching circuit can be designed independently.

  Moreover, the structure provided only with the matching circuit may be sufficient. Furthermore, a circuit in the feeder circuit board may be configured only by the inductance element. In this case, the inductance element has a function of matching the impedance between the radiation plates 21a and 21b, which are antennas, and the wireless IC chip 5.

  In the power supply circuit board 10 shown in FIG. 8, the external electrodes 19a and 19b are not necessarily required, and the radiation plates 21a and 21b are directly joined to the back surface of the power supply circuit board 10 in place of the external electrodes 19a and 19b. Also good.

(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.

  For example, the resonance circuit may have various configurations, and the radiation plates 21a and 21b may be continuous. In addition, the materials of the external electrodes and the power supply circuit board shown in the above embodiments are merely examples, and any materials can be used as long as they have necessary characteristics. Furthermore, processing other than metal bumps may be used to mount the wireless IC chip on the power supply circuit board.

It is sectional drawing which shows the various electromagnetic coupling modules which comprise the radio | wireless IC device which concerns on this invention. It is a perspective view which shows a wireless IC chip. 1 shows a first embodiment of a wireless IC device according to the present invention, where (A) is a plan view and (B) is a cross-sectional view. It is explanatory drawing which shows the manufacturing process of a wireless IC device. It is sectional drawing which shows 2nd Example of the radio | wireless IC device which concerns on this invention. It is sectional drawing which shows the principal part of 3rd Example of the radio | wireless IC device which concerns on this invention. It is sectional drawing which shows the principal part of 4th Example of the wireless IC device which concerns on this invention. It is a disassembled perspective view which shows the electric power feeding circuit board incorporating an example of a resonant circuit.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Electromagnetic coupling module 5 ... Wireless IC chip 10 ... Power feeding circuit board 19a, 19b ... External electrode 21a, 21b ... Radiation plate 23 ... Protective film 50 ... Base material L1, L2 ... Inductance element C1, C2 ... Capacitance element

Claims (10)

A wireless IC chip for processing transmission and reception signals;
Including an inductance element, a power supply circuit board that said inductance element is connected to the wireless IC chip,
A radiation plate arranged to be coupled to the inductance element;
A base material provided with the radiation plate;
With
Configure the module by mounting the wireless IC chip on the feeder circuit board,
Said motor at least a portion of the Joule is embedded in the radiation plate,
The upper surface and the back surface of the feeder circuit board and at least one side surface are in contact with the radiation plate;
A wireless IC device characterized by the above.   The wireless IC device according to claim 1, wherein a resonance circuit is formed on the power supply circuit board.   3. The wireless IC device according to claim 1, wherein a matching circuit is formed on the power supply circuit board. A wireless IC chip for processing transmission and reception signals;
A feeder circuit board including an inductance element, the inductance element being connected to the wireless IC chip;
A radiation plate arranged to be coupled to the inductance element;
A base material provided with the radiation plate;
With
The wireless IC chip is mounted on the power supply circuit board to constitute a module,
At least a portion of the module is embedded in the radiation plate;
A resonance circuit and / or a matching circuit is formed on the power supply circuit board,
A plurality of the radiation plates are arranged at a predetermined interval,
The resonance circuit and / or the matching circuit of the feeder circuit board are arranged to be electromagnetically coupled to the plurality of radiation plates;
A wireless IC device characterized by the above. The wireless IC device according to claim 3 or 4 , wherein the matching circuit has a function of matching impedance between the radiation plate and the wireless IC chip. 3. An external electrode that is electromagnetically coupled to the resonance circuit and / or the matching circuit is formed on a surface of the feeder circuit board, and the external electrode is electrically connected to the radiation plate. The wireless IC device according to claim 5 . The wireless IC device according to any one of claims 1 to 6 , wherein the wireless IC chip and / or the power feeding circuit board is covered with a protective film. The feeder circuit board wireless IC device according to any one of claims 1 to 7, characterized in that it is constituted by a multilayer substrate. Preparing a base material for forming the radiation plate;
A step of the feeder circuit board including an inductance element, equipped with a wireless IC chip that processes transmission and reception signals in a connected state with the inductance element to form a module,
Forming a radiation plate with a viscous conductive material on the substrate;
A step of mounting the module to at least one side surface and the upper surface and the back surface of the feeder circuit board is embedded in the radiation plate,
Curing the conductive material;
A method of manufacturing a wireless IC device, comprising: Preparing a base material for forming the radiation plate;
Mounting a wireless IC chip for processing transmission / reception signals in a connected state with the inductance element on a power supply circuit board including the inductance element, and configuring a module;
Forming a radiation plate with a viscous conductive material on the substrate;
Mounting the module such that at least a portion of the module is embedded in the radiation plate;
Curing the conductive material;
A method of manufacturing a wireless IC device comprising:
A resonance circuit and / or a matching circuit is formed on the power supply circuit board,
A plurality of the radiation plates are arranged at a predetermined interval,
The resonance circuit and / or the matching circuit of the feeder circuit board are arranged to be electromagnetically coupled to the plurality of radiation plates;
A method for manufacturing a wireless IC device.

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