WO2022097682A1

WO2022097682A1 - Container provided with rfid module

Info

Publication number: WO2022097682A1
Application number: PCT/JP2021/040609
Authority: WO
Inventors: 亮平大森; 登加藤; 浩和矢▲崎▼; 幹子齋藤
Original assignee: 株式会社村田製作所
Priority date: 2020-11-09
Filing date: 2021-11-04
Publication date: 2022-05-12
Also published as: JP7201137B2; JPWO2022097682A1

Abstract

Provided is a container provided with: an insulating base material forming the outer shape of the container; a metal film formed on the base material; a slot formed in the base material in the region in which the metal film is formed; and an RFID module. The RFID module is provided with: an RFIC element; a filter circuit which transmits an electric current resulting from electromagnetic waves having a unique resonant frequency, which is a communication frequency, to the RFIC element; and first and second electrodes connected to the filter circuit. The first electrode of the RFID module and the metal film are electrically connected to one another, and the second electrode of the RFID module and the metal film are electrically connected to one another with the RFID module straddling the slot.

Description

Container with RFID module

The present invention relates to a container equipped with an RFID module, particularly a container equipped with an RFID module using RFID (Radio Frequency Identification) technology for non-contact data communication by an induced electromagnetic field or radio waves.

Conventionally, it has been considered to manage products in a container by attaching an RFID tag, which is a wireless communication device, to the container. In RFID tags, along with RFIC (Radio-Frequency Integrated Circuit), metal materials such as antenna patterns are formed on insulating substrates such as paper materials and resin materials. However, if a metal film is formed on the outer surface of the container, the RFID tag is affected and communication becomes impossible.

In the above-mentioned container with an RFID tag, Patent Document 1 proposes a configuration in which an RFID tag compatible with a metal formed in a part of the container is provided so as not to impair the design.

International Publication No. 2019-039484

The RFID tag disclosed in Patent Document 1 has an RFID chip and an antenna pattern, and a metal film cannot be formed on the container in these regions. Therefore, there is a demand for a container having an RFID module that suppresses a reduction in the degree of freedom in design.

An object of the present invention is to provide a container having an RFID module in which a reduction in design is suppressed in a container on which a metal film is formed.

The container of one aspect of the present invention is a container provided with an RFID module, in which an insulating base material forming the outer shape of the container, a metal film formed on the base material, and a region in which the metal film is formed are formed. The RFID module is provided with a slot formed on a base material, and the RFID module is connected to the RFID element, a filter circuit that transmits a current generated by an electromagnetic wave having a unique resonance frequency, which is a communication frequency, to the RFID element, and a filter circuit. The first and second electrodes are provided, the first electrode of the RFID module and the metal film are electrically connected, the RFID module straddles the slot, and the second electrode of the RFID module and the metal film are electrically connected. To.

According to the present invention, it is possible to provide a container having an RFID module in which a reduction in design is suppressed in a container on which a metal film is formed.

Overall perspective view of the container having the RFID module of the first embodiment. II-II arrow cross-sectional view in FIG. Development view of the container in FIG. Perspective plan view of RFID module Sectional view of arrow V in FIG. A plan view of the conductor pattern formed on the substrate of the RFID module is shown, FIG. 6a is a plan view of the conductor pattern formed on the upper surface of the substrate of the RFID module, and FIG. 6b is a plan view of the conductor pattern formed on the lower surface of the substrate. Perspective plan seen from above Sectional view of arrow VII in FIG. Equivalent circuit diagram of RFID module Overall perspective view of the container in the modified example of the first embodiment Overall perspective view of the container in the modified example of the first embodiment Development view of the container in the modified example of the first embodiment Cross-sectional view of the container in the modified example of the first embodiment Cross-sectional view in which the containers of the modified example of the first embodiment are arranged in an overlapping manner. Overall perspective view of the container in the modified example of the first embodiment Cross-sectional view of the RFID module in the modified example of the first embodiment Development view of the container in the modified example of the first embodiment Development view of the container in the modified example of the first embodiment Development view of the container in the modified example of the first embodiment Overall perspective view of the container in the modified example of the first embodiment Cross-sectional view in which the containers of the modified example of the first embodiment are arranged in an overlapping manner. Overall perspective view of the container in the modified example of the first embodiment Overall perspective view of the container in the modified example of the first embodiment Overall perspective view of the container in the modified example of the first embodiment A graph showing the communication characteristics of the RFID module of the second embodiment.

The container of one aspect according to the present invention is a container provided with an RFID module, and has an insulating base material forming the outer shape of the container, a metal film formed on the base material, and a region where the metal film is formed. The RFID module is provided with a slot formed on a substrate inside, and the RFID module is connected to the RFID element, a filter circuit that transmits a current generated by an electromagnetic wave having a unique resonance frequency, which is a communication frequency, to the RFID element, and a filter circuit. The first and second electrodes are provided, the first electrode of the RFID module and the metal film are electrically connected, the RFID module straddles the slot, and the second electrode of the RFID module and the metal film are electrically connected. Will be done.

Since the container of this embodiment uses the metal film formed on the base material of the container as an antenna, the RFID module is attached to the container in which the metal film is formed while suppressing the reduction in the degree of freedom in design. Can be done.

Further, when the metal film is irradiated with an electromagnetic wave having a communication frequency, a current may flow in the direction of orbiting the slot. As described above, since the metal film functions as a slot antenna, communication characteristics as a slot antenna can be obtained.

The length of the slot may have a physical length of half the wavelength of the electromagnetic wave of the communication frequency. In this case, the maximum communication distance as a slot antenna is often obtained.

The container equipped with the RFID module may be a prefabricated box.

The side surface of the box may have a recess extending in the longitudinal direction of the side surface, and a slot may be formed in the recess. This prevents the slot from coming into contact with the metal film even if multiple containers are arranged in the same orientation, and the metal film of the other container causes the slot to short-circuit and conduct without passing through the RFID module. not. Therefore, it is possible to communicate with a plurality of containers at once. Further, since the concave portion is formed, a gap is formed between the containers when the containers are arranged, and electromagnetic waves for communication are easily transmitted.

Slots may be formed at the corners between the first and second sides of the box.

The slot may be formed in a tapered portion formed between the first side surface and the second side surface of the box. This prevents the slot from coming into contact with the metal film even if multiple containers are arranged in the same orientation, and the metal film of the other container causes the slot to short-circuit and conduct without passing through the RFID module. not. Therefore, it is possible to communicate with a plurality of containers at once. Further, since the tapered portion is formed, a gap is formed between the containers when the containers are arranged, and electromagnetic waves for communication are easily transmitted.

The metal film may be formed on the entire surface of the base material except for the slots. It is also possible to realize a design in which a metal film is formed on the entire outer surface of the container.

The filter circuit may be an LC parallel resonant circuit. As a result, a current having a frequency matching the RFIC can be passed through the RFIC.

The filter circuit has a coil formed on the substrate, and the coil may be covered with a protective layer. As a result, the dielectric constant of the coil can be fixed, and it is possible to prevent the influence of the dielectric material in the container.

The coil of the filter circuit may have a figure eight shape. As a result, the magnetic field of the coil can be made difficult to leak to the outside, and the inductance value of the coil can be made difficult to change due to an external factor.

The sheet resistance of the metal film may be 0.5Ω / □ or more. Even with this configuration, since the RFID module has a filter circuit, the eddy current generated in the metal film can be used to flow through the RFID.

The thickness of the metal film may be 1 nm or more and 1 μm or less. Even with this configuration, since the RFID module has a filter circuit, the eddy current generated in the metal film can be used to flow through the RFID.

Note that all of the embodiments described below show a specific example of the present invention, and the present invention is not limited to this configuration. Further, the numerical values, shapes, configurations, steps, the order of steps, etc. specifically shown in the following embodiments are only examples, and do not limit the present invention. Among the components in the following embodiments, the components not described in the independent claim indicating the highest level concept are described as arbitrary components. Further, in all the embodiments, the configuration in each modification is the same, and the configurations described in each modification may be combined.

When the relative permittivity εr> 1, the electrical length of the antenna pattern and the conductor pattern is longer than the physical length. In the present specification, the electrical length is a length considering the shortening or extension of the wavelength due to the relative permittivity and the parasitic reactance component.

(Embodiment 1)
Next, a schematic configuration of the container 1 provided with the RFID module 5 according to the present invention will be described. FIG. 1 is an overall perspective view of a container 1 having an RFID module 2 according to the first embodiment of the present invention. FIG. 2 is a cross-sectional view taken along the line II-II in FIG. 1, and FIG. 3 is a developed view of the container 1 in FIG.

The container 1 of the first embodiment is formed in the base material 3, the RFID module 5 attached to the base material 3, the metal film 7 formed on the first main surface 3s of the base material 3, and the metal film 7. The slot 9 is provided.

The container 1 is, for example, an assembly-type box formed into a three-dimensional shape by assembling a flat base material 3 as shown in FIG. The container 1 has a rectangular parallelepiped shape, for example, and the base material 3 is made of, for example, paper, resin, or plastic.

The base material 3 includes a first surface 3a, a second surface 3b, a third surface 3c, a fourth surface 3d, a fifth surface 3e, a sixth surface 3f, and a first flap 3g, a second flap 3h, and a third flap. Equipped with 3k. For example, the first surface 3a to the fourth surface 3d become a side surface when assembled, the fifth surface 3e becomes an upper surface when assembled, and the sixth surface 3f becomes a lower surface when assembled. The first main surface 3s of the base material 3 is a surface to be the outer surface (front surface) of the container 1, and the second main surface 3t of the base material 3 is a surface to be the inner surface (back surface) of the container 1.

The first main surface 3s of the first flap 3g is attached to the second main surface 3t of the second surface 3b via an adhesive layer (not shown) when assembled. The first main surface 3s of the second flap 3h is attached to the second main surface 3t of the first surface 3a via an adhesive layer when assembled. The first main surface 3s of the third flap 3k is attached to the second main surface 3t of the first surface 3a via an adhesive layer when assembled.

The metal film 7 is formed on the entire surface of the first main surface 3s of the base material 3 except for the slot 9. The metal film 7 is made of a film body of a conductive material of a metal foil such as an aluminum foil or a copper foil, and is formed by, for example, attaching a metal sheet. By using a metal having a small resistance value such as aluminum or copper as the metal film 7, the communication distance can be increased. The thickness of the metal film 7 is, for example, larger than 5 μm and 40 μm or less. The metal film 7 may not be formed on the entire surface of the base material 3, and may be partially formed on the third surface 3c on which the slot 9 is formed and another surface, for example.

When the length Lg of the slot 9 is the length of the half wavelength of the electromagnetic wave of the communication frequency, the communication distance becomes the maximum. When the container 1 is irradiated with an electromagnetic wave having a communication frequency, communication is performed in a direction that orbits the slot 9 so as to reciprocate from the RFID module 5 located at the center of the longitudinal direction of the slot 9 to the ends of the two slots 9. It resonates with the frequency and the current Ir flows (see FIG. 1).

The slot 9 is a groove formed in the region of the metal film 7. The width W of the slot 9 is, for example, 1 mm. The slot 9 may be formed by forming the metal film 7 on the entire first main surface 3s of the base material 3 and then scraping the metal film 7 with, for example, sandpaper, or two metal sheets are slotted. It may be formed by attaching it to the first main surface 3S of the base material 3 with a width of 9. The slot 9 is not limited to the third surface 3c of the base material 3, but may be formed on another surface.

The RFID module 5 of the first embodiment is a wireless communication device configured to perform wireless communication (transmission / reception) with a high frequency signal having a communication frequency (carrier frequency). The RFID module 5 is configured to perform wireless communication with, for example, a high frequency signal having a frequency for communication in the UHF band. Here, the UHF band is a frequency band from 860 MHz to 960 MHz.

Next, the configuration of the RFID module 5 will be described with reference to FIGS. 4 to 7. FIG. 4 is a perspective plan view of the RFID module, and FIG. 5 is a cross-sectional view taken along the line V in FIG. FIG. 6 shows a plan view of a conductor pattern formed on the substrate of the RFID module, FIG. 6a is a plan view of the conductor pattern formed on the upper surface of the substrate of the RFID module, and FIG. 6b is a plan view of the conductor pattern formed on the lower surface of the substrate. It is a perspective plan view seen from the top of the conductor pattern. FIG. 7 is a cross-sectional view taken along the line VII in FIG. In the figure, the XYZ coordinate system facilitates the understanding of the invention and does not limit the invention. The X-axis direction indicates the longitudinal direction of the RFID module 5, the Y-axis direction indicates the depth (width) direction, and the Z-axis direction indicates the thickness direction. The X, Y, and Z directions are orthogonal to each other.

As shown in FIG. 4, the RFID module 5 is attached to the upper surface of the metal film 7 across the slot 9 via a pressure-sensitive adhesive 15 such as double-sided tape or synthetic resin.

As shown in FIG. 5, the RFID module 5 includes a substrate 21 and an RFID 23 mounted on the substrate 21. The substrate 21 is a flexible substrate such as polyimide. A protective film 25 is formed on the upper surface of the substrate 21 on which the RFIC 23 is mounted. The protective film 25 is, for example, an elastomer such as polyurethane or a hot melt agent such as ethylene vinyl acetate (EVA). A protective film 27 is also attached to the lower surface of the substrate 21. The protective film 27 is, for example, a coverlay film such as a polyimide film (Kapton tape).

Refer to FIG. On the upper surface of the substrate 21, a third electrode 33, a fourth electrode 35, a conductor pattern L1a of the main portion of the first inductance element L1 and a conductor pattern L2a of the main portion of the second inductance element L2 are formed. The third electrode 33 is connected to one end of the conductor pattern L1a, and the fourth electrode 35 is connected to one end of the conductor pattern L2a. These conductor patterns are, for example, a copper foil patterned by photolithography.

On the lower surface of the substrate 21, the first electrode 29 and the second electrode 31 are capacitively coupled to the metal film 7, respectively. Further, on the lower surface of the substrate 21, a part of the conductor pattern L1b of the first inductance element L1 and the conductor patterns L3a, L3b (conductor pattern surrounded by the alternate long and short dash line) and L3c of the third inductance element L3 are formed. These conductor patterns are also, for example, a copper foil patterned by photolithography.

One end of a part of the conductor pattern L1b of the first inductance element L1 and one end of the conductor pattern L3a of the third inductance element L3 are connected to the first electrode 29. Similarly, one end of the conductor pattern L2b of the second inductance element L2 and one end of the conductor pattern L3c of the third inductance element L3 are connected to the second electrode 31. A conductor pattern L3b is connected between the other end of the conductor pattern L3a of the third inductance element L3 and the other end of the conductor pattern L3c.

The other end of the conductor pattern L1b of the first inductance element L1 and the other end of the conductor pattern L1a of the first inductance element L1 are connected via the via conductor V1. Similarly, the other end of the conductor pattern L2b of the second inductance element L2 and the other end of the conductor pattern L2a of the second inductance element L2 are connected via the via conductor V2.

The RFIC 23 is mounted on the third electrode 33 and the fourth electrode 35 formed on the upper surface of the substrate 21. That is, the terminal 23a of the RFIC 23 is connected to the third electrode 33, and the terminal 23b of the RFIC 23 is connected to the fourth electrode 35.

The conductor patterns L3a of the first inductance element L1 and the third inductance element L3 are formed in different layers of the substrate 21, and are arranged so that their coil openings overlap each other. Similarly, the conductor patterns L3c of the second inductance element L2 and the third inductance element L3 are formed in different layers of the substrate 21, and the coil openings are arranged so as to overlap each other. Further, the RFIC 23 is positioned on the surface of the substrate 21 between the conductor pattern L3c of the second inductance element L2 and the third inductance element L3 and the conductor pattern L3a of the first inductance element L1 and the third inductance element L3. do. The conductor patterns L1a, L1b, and L3a form the first coil Cr1, and the conductor patterns L2a, L2b, and L3c form the second coil Cr2.

In the RFID module 5, a first current path CP1 passing through the upper surface and the lower surface of the substrate 21 and a second current path CP2 passing through the lower surface of the substrate 21 are formed. The first current path CP1 reaches the second electrode 31 from the first electrode 29 through the branch point N1, the conductor pattern L1b, the conductor pattern L1a, RFIC23, the conductor pattern L2a, the conductor pattern L2b, and the branch point N2. The second current path CP2 reaches the second electrode 31 from the first electrode 29 through the branch point N1, the conductor pattern L3a, the conductor pattern L3b, the conductor pattern L3c, and the branch point N2. Here, it is composed of a first inductance element L1 composed of a conductor pattern L1b connected via a conductor pattern L1a and a via conductor V1, and a conductor pattern L2b connected via a conductor pattern L2a and a via conductor V2. The winding directions of the current flowing through the second inductance element L2 are opposite to each other, and the magnetic field generated by the first inductance element L1 and the magnetic field generated by the second inductance element L2 cancel each other out. The first current path CP1 and the second current path CP2 are formed in parallel with each other between the first electrode 29 and the second electrode 31, respectively.

Conventionally, when a slot antenna is provided in a container, the slot antenna may be affected by the contents in the container and communication may be hindered. This is because the physical length of the slot is fixed, and if the electrical length of the slot is affected by the contents such as liquid and changes, communication may not be possible. Therefore, the slot antenna is not suitable as an antenna to be formed in the container.

When a dielectric such as a liquid is stored in a container, the dielectric constant of the RFID tag changes and the electrical length of the slot becomes shorter than the half wavelength of the electromagnetic wave of the communication frequency. The change in permittivity also changes depending on the distance between the contents and the slot antenna. Therefore, each time the position of the contents changes in the box, the communication characteristics also change.

In the first embodiment, in order to avoid the wavelength change (frequency change) due to the change in the permittivity, the resonance frequency is fixed by the RFID module 5 instead of designing the frequency by the length of the slot 9, so that the slot 9 is used. It can respond to frequency changes due to length.

Further, the RFIC 23 is a small chip, and each coil pattern is wound so that the first coil Cr1 and the second coil Cr2 having a laminated structure cancel the magnetic field. As a result, the periphery of the RFID module 23 is fixed by the dielectric constant of the RFID module 5 and is not affected by the dielectric (contents) contained in the container 1, so that the frequency matching with the RFID module 23 does not change. Referring to FIG. 7, the permittivity of the substrate 21 between the conductor patterns L1a and L2a and the conductor patterns L3a and L3c is fixed, and there is no change between the line capacitances. Further, the conductor patterns L1a and L2a and the conductor patterns L3a and L3c are covered with a protective film 25 and a protective film 27 as a protective layer having a fixed dielectric constant, respectively. In this way, the dielectric constant of the RFID module 5 is fixed.

Further, in order to reduce the influence of the dielectric constant of the dielectric in the container 1, a figure eight coil is formed by the first coil Cr1 and the second coil Cr2 of the RFID module 5, and the magnetic field of the RFID module 5 is formed. Is a configuration that does not easily leak to the outside. Since the magnetic field of the RFID module 5 is less likely to leak, the inductance value is less likely to change due to external factors.

Further, since the magnetic flux of the RFID module 5 is also closed, the change in the frequency matching with the RFID 23 is small even when the metal is housed in the container 1.

Next, the circuit configuration of the RFID module 5 will be described with reference to FIG. FIG. 8 is an equivalent circuit diagram of the RFID module 5.

In the RFID module 5, the first current path CP1 is a part of the parallel resonant circuit RC1 which is an LC parallel resonant circuit, and matches the radio wave of the communication frequency. Therefore, the radio wave of the communication frequency is transmitted to the metal film 7. Is received, a current flows through the RFIC 23.

The RFID module 5 is formed with a parallel resonant circuit RC1. The parallel resonant circuit RC1 is a loop circuit composed of a first inductance element L1, an RFIC23, a second inductance element L2, and a third inductance element L3.

Capacity C1 is composed of a metal film 7, a first electrode 29, an adhesive 15, and a protective film 27. The capacitance C2 is composed of a metal film 7, a second electrode 31, an adhesive 15, and a protective film 27. The fourth inductance element L4 is an inductance component of one metal film 7, and the fifth inductance element L5 is an inductance component of the other metal film 7. Since the RFID module 5 is electrically coupled to the metal film 7 forming the slot 9 via the capacitance C1 and the capacitance C2, the current flowing around the slot 9 is both the fourth inductance element L4 of the metal film 7. A current diverges and flows through the RFID module 5 through the fifth inductance element L5 of the other metal film 7 via the end of the slot 9 and through the capacitance C2.

The parallel resonance circuit RC1 is designed to perform LC parallel resonance by impedance matching with radio waves at the communication frequency. As a result, the RFID module is matched with the RFID in the communication frequency, and the communication distance of the RFID module 5 in the communication frequency can be secured.

As described above, the container 1 of the first embodiment is the container 1 provided with the RFID module 5, the insulating base material 3 forming the outer shape of the container 1 and the metal film 7 formed on the base material 3. And a slot 9 formed on the base material 3 in the region where the metal film 7 is formed. The RFID module 5 includes an RFIC 23, a parallel resonance circuit RC1 as a filter circuit for transmitting a current due to an electromagnetic wave having a unique resonance frequency which is a communication frequency to the RFIC 23, and a first electrode 29 and a second electrode connected to the parallel resonance circuit RC1. 31 and. The first electrode 29 of the RFID module 5 and the metal film 7 are electrically connected, and the RFID module 5 straddles the slot 9 and the second electrode 31 of the RFID module 5 and the metal film 7 are electrically connected.

Since the RFID module 5 is arranged across the slot 9 formed in the metal film 7 formed on the base material 3 of the container 1, the slot 9 can be used as a slot antenna, and the current is applied to the RFID 23 by series resonance. Can be shed. Therefore, even if the container 1 is formed with the metal film 7, wireless communication is possible, and it is possible to provide the container 1 having the RFID module 5 in which the reduction in design is suppressed. Further, the container 1 of the first embodiment can be provided at a lower cost than the container to which the conventional metal-compatible RFID module is attached.

When the metal film 7 is irradiated with an electromagnetic wave having a communication frequency, a current flows in the direction around the slot 9. As described above, since the metal film 7 around the slot 9 functions as a slot antenna, the container 1 can obtain communication characteristics as a slot antenna.

Further, the length of the slot 9 has a physical length of half the wavelength of the electromagnetic wave of the communication frequency. As a result, the maximum communication distance as a slot antenna is often obtained.

The metal film 7 is formed on the entire surface of the first main surface 3s of the base material 3 except for the slot 9. As described above, a design in which the metal film 7 is formed on the entire surface of the first main surface 3s of the container 1 can be realized.

Next, a modification 1 of the first embodiment will be described with reference to FIG. FIG. 9 is an overall view of the container 1A in the first modification of the first embodiment. The container 1A in the first modification of the first embodiment has a configuration in which the slot 9 of the container 1 of the first embodiment is formed over the second surface 3b and the third surface 3c. In this way, the slot 9 may extend over a plurality of side surfaces in a direction that orbits the container 1A in the lateral direction. Other configurations of the first modification of the first embodiment are substantially the same as those of the container 1 of the first embodiment.

Next, a modification 2 of the first embodiment will be described with reference to FIGS. 10 and 11. FIG. 9 is an overall view of the container 1B in the second modification of the first embodiment. FIG. 10 is a developed view of the container 1B in the second modification of the first embodiment. The container 1B in the second modification of the first embodiment has a configuration in which the slot 9 of the container 1 of the first embodiment is formed along the long side of the third surface 3c. Other configurations of the second modification of the first embodiment are substantially the same as those of the container 1 of the first embodiment.

As shown in FIG. 10, the container 1B in the second modification has a current Ir flowing so as to orbit along the slot 9, and supplies electric power to the RFID module 5. A part of the current Ir passes through the fifth surface 3e and the sixth surface 3f.

Further, as shown in FIG. 12, the third surface 3c may have a recess 3v extending in the vertical direction. FIG. 12 is a cross-sectional view of the container 1C in the modified example 3 of the first embodiment. Other configurations of the third modification of the first embodiment are substantially the same as those of the container 1 of the first embodiment. The metal film 7 is also formed along the recess 3v, and the slot 9 is formed at the bottom of the recess 3v.

As shown in FIG. 13, since the container 1C has a recess 3v extending in the longitudinal direction on the third surface 3c which is the side surface of the container 1C, even if a plurality of containers 1C are brought into contact with each other and arranged, the slot 9 in the recess 3v Since the metal film 7 of the other container 1c does not come into contact with the container 1, the slot 9 is not short-circuited. Therefore, it is possible to perform wireless communication with a plurality of containers 1C only by aligning the heights of the containers 1C. Further, since the concave portion 3v is formed, a gap is formed between the container 1C and the container 1C when the containers 1C are arranged, and the electromagnetic wave for communication is easily transmitted.

Further, as shown in FIG. 14A, the slot 9 may be formed at a corner between one side surface and the other side surface of the box. For example, a slot 9 is formed at a corner between the second surface 3b and the third surface 3c. By making a cut that reaches the second surface 3b and the third surface 3c in the expanded state of the box-shaped container 1D, this cut becomes the slot 9 when the container 1D is assembled. When the RFID module 5 is composed of a flexible member as shown in FIG. 14B, the RFID module starts from between the inner end of the metal film 7, the first electrode 29 and the second electrode 31, and the conductor pattern L3b. By bending the module 5, the portions of the first electrode 29 and the second electrode 31 used for the capacitive coupling at both ends of the RFID module 5 can be arranged on a plane different from the RFID 23 so as to follow the corner of the container 1D. Further, in the state where the container 1D is already attached to the metal film 7 across the cut which becomes the slot 9, since the cut is closed, the slot 9 is in a short-circuited state, so that it cannot communicate with the RFID module 5. However, when the container 1D is assembled, the slot 9 is formed so that the RFID module 5 can communicate. Therefore, it is possible to determine whether or not the assembly of the box-shaped container 1D is completed by communicating with the RFID module 5.

Next, a modification 4 of the first embodiment will be described with reference to FIG. FIG. 15 is a developed view of the container 1E in the modified example 4 of the first embodiment. In the container 1E in the modified example 4 of the first embodiment, the shape of the slot 9 is not a linear shape but a corrugated shape in the container 1 of the first embodiment. Even with such a configuration, the communication characteristics do not change, so that the container 1E of the modified example 4 of the first embodiment can obtain the same effect as the container 1 of the first embodiment.

Next, a modification 5 of the first embodiment will be described with reference to FIG. FIG. 16 is a developed view of the container 1F in the modified example 5 of the first embodiment. In the container 1F in the modified example 5 of the first embodiment, the shape of the slot 9 is not a linear shape but a corrugated shape in the container 1 of the first embodiment. Further, both ends of the slot 9 have a rectangular shape having a planar extension. As described above, even if the slot 9 has a combined shape of a corrugated shape and a rectangular shape, the communication characteristics do not change. Therefore, the container 1F of the modified example 5 of the first embodiment is the same as the container 1 of the first embodiment. A similar effect can be obtained.

Next, a modification 6 of the first embodiment will be described with reference to FIG. FIG. 17 is a developed view of the container 1G in the modified example 6 of the first embodiment. In the container 1 of the first embodiment, the container 1G in the modified example 6 of the first embodiment is inclined with respect to the long side of the third surface 3c on which the slot 9 is a side surface and extends in the vertical direction, and both ends thereof are second. It bends and extends along the short sides of the three sides and 3c. Even with such a shape of the slot 9, the communication characteristics do not change, so that the container 1G of the modification 6 of the first embodiment can obtain the same effect as the container 1 of the first embodiment.

Next, a modification 7 of the first embodiment will be described with reference to FIG. FIG. 18 is an overall perspective view of the container 1H in the modified example 7 of the first embodiment. The container 1H in the modified example 7 of the first embodiment has a tapered portion 3u having a tapered portion between the second surface 3b and the third surface 3c in the container 1 of the first embodiment, and is on the tapered portion 3u. This is a configuration in which the slot 9 is formed. A metal film 7 is continuously formed at the end of the tapered portion 3u in the width direction. Therefore, it is possible to arrange the RFID module 5 on the tapered portion 3u without bending it.

FIG. 19 shows a cross-sectional view in which the containers 1H of the modified example 7 of the first embodiment are arranged in an overlapping manner. Since the container 1H has a slot 9 formed in the tapered portion 3u, even if a plurality of containers 1H are brought into contact with each other and arranged, the metal film 7 of the other container 1H may come into contact with the slot 9 of the tapered portion 3u. not. As a result, the slot 9 of the container 1H is not short-circuited. Therefore, it is possible to perform wireless communication with a plurality of containers 1H only by aligning the heights of the containers 1H. Further, since the tapered portion 3u is formed in the container 1H, a gap is formed between the container 1H and the container 1H when the containers 1H are arranged, and the electromagnetic wave for communication is easily transmitted.

Next, a modification 8 of the first embodiment will be described with reference to FIG. 20. FIG. 20 is an overall perspective view of the container 1K in the modified example 8 of the first embodiment. The container 1K in the modified example 8 of the first embodiment has a configuration in which the container 1 of the first embodiment has two intersecting slots 9. Other configurations are substantially the same as the container 1 of the first embodiment. The RFID module 5 is arranged at the intersection of the intersecting slots 9. In this way, the degree of freedom in the design of the container 1H by the slot 9 can be improved. Further, as shown in FIGS. 20 and 21, the RFID module 5 is arranged with respect to the intersecting slots 9 so that the current flows in the lateral direction of the container 1K with respect to the RFID module 5, and flows in the vertical direction. Since it is possible to arrange the RFID module 5 in two ways, the communication characteristics of the RFID module 5 can be selected.

In the case of the container 1K shown in FIG. 20, the RFID module 5 has the first region 3ca and the second region 3cc as the radiation region in the third surface 3c. On the other hand, in the case of the container 1K shown in FIG. 21, the RFID module 5 has the third region 3cc and the fourth region 3cd as the radiation region in the third surface 3c.

Next, a modification 9 of the first embodiment will be described with reference to FIG. 22. FIG. 22 is a developed view of the container 1L in the modified example 9 of the first embodiment. In the container 1L in the modified example 9 of the first embodiment, the slot 9 is formed on the fifth surface 3e which is the upper surface of the container 1L of the modified example 9 of the first embodiment. As described above, even if the RFID module 5 is arranged on the upper surface of the container 1, the communication characteristics do not change. Therefore, the container 1L of the modified example 9 of the first embodiment has the same effect as the container 1 of the first embodiment. Can be obtained.

(Embodiment 2)
Hereinafter, the container 1 of the second embodiment according to the present invention will be described.

The difference between the container 1 of the second embodiment and the container 1 of the first embodiment is the difference in the sheet resistance of the metal film 7. This difference will be mainly described below. In the description of the second embodiment, the description may be omitted for the elements having the same configuration, operation, and function as those of the first embodiment, in order to avoid duplicate description. The container 1 of the second embodiment has the same configuration as the RFID module 5 of the first embodiment except for the points described below.

The sheet resistance of the metal film 7 of the container 1 of the second embodiment is larger than the sheet resistance of the metal film 7 of the container 1 of the first embodiment. When the sheet resistance of the metal film 7 is large, the following problems that did not occur in the container 1 of the first embodiment occur.

In the container 1 of the first embodiment, a resonance phenomenon occurred in the entire metal film 7 around the slot 9 as an antenna electrode, and electromagnetic waves were radiated. The thickness of the metal film 7 in the first embodiment is, for example, larger than 5 μm and 40 μm or less, and the sheet resistance of the metal film 7 is 0.05 Ω / □ or less.

The metal film of the container is usually formed to prevent food oxidation and improve the design, but even if the thickness of the metal film is a single digit value in μm units such as 5 μm, the metal film is further formed. In addition, when printing by gravure printing or offset printing as a design, the printing thickness becomes about 1 μm. In this case, a step is generated in the printed matter due to the thickness of the metal film as the antenna foil, which causes printing misalignment (blurring or bleeding). For this reason, it was not possible to print directly as a design on a container with a conventional antenna foil attached.

When the metal film as an antenna is formed by the vapor deposition method, the thickness of the metal film is further reduced to about 10 Å (= 1 nm) to 10000 Å (= 1 μm). If the metal film is of this thickness, printing bleeding due to steps does not occur even if gravure printing is performed on it, but a metal film (deposited film) of this thickness, for example, aluminum foil, has a small film thickness. The sheet resistance becomes large, for example, about 0.5Ω to 50Ω / □.

When the sheet resistance of the metal film increases, even if a series resonance phenomenon that creates a stationary wave in the entire antenna electrode due to the metal film occurs, the radiation power becomes almost heat due to the resistance of the metal foil, so electromagnetic wave radiation as an antenna. Can't do.

Also, since the resistance value of the matching circuit section between the RFIC and the antenna will be the same thickness as the metal film, the resistance value of the matching circuit section will increase, the matching loss will increase, and the RFID module will not operate.

In this way, an antenna electrode made of a thin metal film cannot generate electromagnetic wave radiation due to the (series) resonance phenomenon, but when an electromagnetic wave is received by the metal film, a current flows through the metal film so as to cancel the electromagnetic wave. To shield. This current is also called an eddy current. When an eddy current flows, the current component flowing through the metal film is not due to the resonance phenomenon of the antenna electrode, so that it can correspond to all frequency components regardless of the electrode pattern shape. This eddy current is known as an effect of the metal shield, but it is not usually used as an antenna.

Since the RFID module 5 has a parallel resonant circuit RC1 as a filter circuit that transmits only a current having a unique resonance frequency to the RFID 23, the eddy current is frequency-selected and the current flows through the RFID 23 to transmit energy. Only a specific frequency is selected between the metal film 7 as an antenna electrode and the RFID module 5, impedance matching is performed, and energy transfer between the RFID 23 and the metal film 7 becomes possible. In this way, it is considered that communication with the RFIC 23 becomes possible.

Therefore, in the case of the container 1 of the second embodiment, even when the sheet resistance of the metal film 7 is high, communication can be enabled by using an eddy current which has not been used in the past.

FIG. 23 is a graph showing the communication characteristics of the container 1 provided with the RFID module 5 in the second embodiment. Even in the UHF band of 830 MHz to 960 MHz, it has a communication distance of 100 cm or more, and in particular, it has a communication distance of 200 cm or more in 850 MHz to 895 MHz.

Further, the state where the sheet resistance of the metal film 7 is high occurs not only by the thickness of the metal film 7 but also by the manufacturing method of the metal film 7. For example, when the metal film 7 is formed of a conductive paste such as Ag paste, the sheet resistance may be 0.5Ω or more. Even in such a case, wireless communication can be performed if the container 1 of the second embodiment is used.

The present invention is not limited to those of each of the above embodiments, and can be modified as follows.

(1) In each of the above embodiments, the container 1 is an assembly type, but the present invention is not limited to this. The container 1 may be a bottle or a PET bottle.

(2) In each of the above embodiments, the communication frequency band is the UHF band, but the frequency band is not limited to this. It may be configured to perform wireless communication with a high frequency signal having a frequency (carrier frequency) for communication in the HF band. In this case, the total length of the metal film 7 orthogonal to the slot 9 is designed to receive a high frequency signal in the HF band. The HF band is a frequency band of 13 MHz or more and 15 MHz or less.

(3) In each of the above embodiments, the RFID module 5 is attached to the metal film 7, but the present invention is not limited to this. The RFIC 23 may be electrically connected to the metal film 7 via an inductor. In this case, the inductor is formed on the metal film 7 side that functions as an antenna pattern. When the inductor is formed on the metal film 7 side, the metal film 7 may have a low sheet resistance by attaching a metal foil as in the first embodiment.

(4) In each of the above embodiments, in the metal film 7, a paint may be applied on a region other than the portion where the RFID module 5 is attached to form a pattern to enhance the design of the container 1. .. Further, the metal film 7 and the slot 9 may be formed on the second main surface 3t which is the inner surface instead of the first main surface 3S which is the outer surface of the base material 3. That is, the metal film 7 and the slot 9 may be formed inside the container 1.

Although the present invention has been described in each embodiment with some detail, the disclosure content of these embodiments should vary in the details of the configuration, and the combination and order of the elements in each embodiment. Changes can be realized without departing from the claimed scope and ideas of the invention.

1 Container 3 Base material 3a 1st surface 3b 2nd surface 3c 3rd surface 3ca 1st area 3cc 2nd area 3cc 3rd area 3cd 4th area 3d 4th surface 3e 5th surface 3f 6th surface 3g 1st flap 3h 2nd flap 3k 3rd flap 3s 1st main surface 3t 2nd main surface 3u Tapered part 3v recess 5 RFID module 5a front surface 5b back surface 7 metal film
9 Slots 15 Adhesive 21 Module Board 23 RFIC
23a Terminal 23b Terminal 25 Protective film 27 Protective film 29 1st electrode 31 2nd electrode 33 3rd electrode 35 4th electrode 37, 39 Conductor pattern L1 1st conductor pattern L1a Conductor pattern L2a Conductor pattern L2 2nd conductor pattern L2a Conductor pattern L2b Conductor pattern L3 Third inductance element L3a Conductor pattern L3b Conductor pattern L3c Conductor pattern L4 Fourth inductance element L5 Fifth inductance element Lg Length CP1 First current path CP2 Second current path Cr1 First coil Cr2 Second coil C1 Capacity C2 capacity Ir current

Claims

A container with an RFID module
An insulating base material that forms the outer shape of the container,
A metal film formed on the first main surface of the base material and
A slot formed on the substrate is provided in the region where the metal film is formed.
The RFID module includes an RFID element, a filter circuit for transmitting a current due to an electromagnetic wave having a unique resonance frequency which is a communication frequency to the RFID element, and first and second electrodes connected to the filter circuit.
The first electrode of the RFID module and the metal film are electrically connected to each other.
The RFID module straddles the slot, and the second electrode of the RFID module and the metal film are electrically connected.
A container with an RFID module.
When the metal film is irradiated with an electromagnetic wave having a communication frequency, a current flows in a direction orbiting the slot.
A container comprising the RFID module according to claim 1.
The length of the slot has a physical length of half the wavelength of the electromagnetic wave of the communication frequency.
A container provided with the RFID module according to claim 2.
The container with the RFID module is a prefabricated box.
A container comprising the RFID module according to any one of claims 1 to 3.
The side surface of the box has a recess extending in the longitudinal direction of the side surface, and a slot is formed in the recess.
A container comprising the RFID module according to claim 4.
The slot is formed at the corner between the first side surface and the second side surface of the box.
A container comprising the RFID module according to claim 4.
The slot is formed in a tapered portion formed between the first side surface and the second side surface of the box.
A container comprising the RFID module according to claim 4.
The metal film is formed on the entire surface of the first main surface of the base material except for the slot.
A container comprising the RFID module according to any one of claims 1 to 7.
The filter circuit is an LC parallel resonant circuit.
A container comprising the RFID module according to any one of claims 1 to 8.
The filter circuit has a coil formed on a substrate and has a coil.
The coil is covered with a protective layer,
A container comprising the RFID module according to claim 9.
The coil of the filter circuit has a figure eight shape.
A container comprising the RFID module according to claim 10.
The sheet resistance of the metal film is 0.5 Ω / □ or more.
A container comprising the RFID module according to any one of claims 1 to 11.
The thickness of the metal film is 1 nm or more and 1 μm or less.
A container comprising the RFID module according to claim 12.