JPWO2019215963A1 - Wireless communication device and article equipped with the same - Google Patents

Abstract

The wireless communication device (10) includes a top plate portion (12a) having a back surface (12d) facing the metal surface (Wa) with a space between the top surface portion (12a) and a top surface standing from the top plate portion (12a) to the back surface side. A casing member (12) including a plate support portion (12b), a main body portion (14a) provided on the back surface (12d) of the top plate portion (12a) of the casing member (12), and a metal surface from the main body portion (14a). An antenna (14) having a connecting portion (14b) extending toward (Wa) and connected to the metal surface (Wa) in a direct current manner or capacitively coupled, and a top plate portion (of the casing member (12) ( It has an RFIC chip (16) provided on the back surface (12d) of 12a) and connected to the antenna (14). The casing member (12) further includes an antenna support portion (12e) that supports the main body portion (14a) with a space provided between the top plate portion (12a) and the main body portion (14a) of the antenna (14). Prepare

Description

  The present invention relates to a wireless communication device capable of wireless communication even when attached to a metal surface, and an article including the wireless communication device.

  For example, in Patent Document 1, a wireless communication device (RFID (Radio-Frequency Integrated Circuit) chip) and a conductor pattern connected thereto are protected by a resin protective case (RFID (Radio-Frequency Integrated Circuit) chip). IDentification) tag) is disclosed. The RFIC chip and the conductor pattern are provided on the surface of the dielectric block, and the dielectric block is housed in the protective case. The conductor pattern is provided on the first main surface of the dielectric block and on the second main surface facing the first main surface and the radiation conductor (antenna) connected to one terminal of the RFIC chip. And a ground conductor connected to the other terminal of the RFIC chip, and a short-circuit conductor connecting the radiation conductor and the ground conductor. By attaching the RFID tag to the metal surface of the article so that the ground conductor faces the metal surface (by capacitively coupling the ground conductor and the metal surface through the protective case), attach the RFID tag to the metal surface. Can also perform wireless communication.

JP, 2012-253700, A

  However, in the case of the RFID tag described in Patent Document 1, the manufacturing cost is high due to the large number of necessary components and the complicated structure. For example, a dielectric block is needed to hold the RFIC chip, the radiation conductor, and so on. Further, it is necessary to provide the RFIC chip, the radiation conductor, and the ground conductor on different surfaces of the dielectric block.

  Therefore, the present invention has an object to protect an RFIC chip and an antenna connected thereto while enabling wireless communication even when attached to a metal surface of an article by a simple structure in a wireless communication device such as an RFID tag. ..

In order to solve the above technical problems, according to one aspect of the present invention,
A wireless communication device that can be used while attached to a metal surface of an article,
A casing member including a top plate portion having a back surface opposed to the metal surface with a space therebetween, and a top plate support portion standingly provided on the back surface side from the top plate portion,
An antenna including a main body portion provided on the back surface of the top plate portion of the casing member, and a connecting portion that extends from the main body portion toward the metal surface and is DC-connected or capacitively coupled to the metal surface. When,
Provided on the back surface of the top plate of the casing member, and having an RFIC chip connected to the antenna,
The casing member further includes an antenna support portion that supports the main body portion of the antenna with a space provided between the top plate portion and the main body portion of the antenna,
A wireless communication device is provided.

According to another aspect of the present invention,
An article having a metal surface on at least a part thereof, wherein the wireless communication device is attached to the metal surface,
The wireless communication device,
A casing member including a top plate portion having a back surface opposed to the metal surface with a space therebetween, and a top plate support portion standingly provided on the back surface side from the top plate portion,
An antenna including a main body portion provided on the back surface of the top plate portion of the casing member, and a connecting portion that extends from the main body portion toward the metal surface and is DC-connected or capacitively coupled to the metal surface. When,
Provided on the back surface of the top plate of the casing member, and having an RFIC chip connected to the antenna,
The casing member further includes an antenna support portion that supports the main body portion of the antenna with a space provided between the top plate portion and the main body portion of the antenna,
Articles are provided.

  According to the present invention, in a wireless communication device such as an RFID tag, it is possible to protect the RFIC chip and the antenna connected thereto while enabling wireless communication even when attached to a metal surface of an article by a simple structure.

1 is a perspective view of a wireless communication device according to an embodiment of the present invention attached to a metal surface of an article. Exploded perspective view of wireless communication device Cross section of wireless communication device FIG. 3 is a perspective view showing an antenna support portion of a cap-shaped member before supporting an antenna Perspective view showing connection between antenna and conductor plate Bottom view of the RFID tag before attaching the seal member Equivalent circuit diagram of RFID tag RFIC module exploded perspective view RFIC module equivalent circuit diagram The exploded perspective view of the wireless-communications device concerning another embodiment of the present invention.

  A wireless communication device according to an aspect of the present invention is a wireless communication device that can be used in a state of being attached to a metal surface of an article, and includes a top plate portion having a back surface facing the metal surface with a space left between them. And a casing member including a top plate support portion standing upright from the top plate portion on the back surface side, a main body portion provided on the back surface of the top plate portion of the casing member, and extending from the main body portion toward the metal surface. An antenna having a connecting portion that is presently connected or capacitively coupled to the metal surface, and an RFIC chip that is provided on the back surface of the top plate portion of the casing member and that is connected to the antenna. The casing member further includes an antenna support portion that supports the main body portion of the antenna with a space provided between the top plate portion and the main body portion of the antenna.

  According to such an aspect, in a wireless communication device such as an RFID tag, it is possible to protect the RFIC chip and the antenna connected thereto while enabling wireless communication even when attached to a metal surface of an article by a simple structure. ..

  The antenna support part may include a spacer part that projects from the back surface of the top plate part of the casing member and has a contact surface that contacts the main body part of the antenna. The spacer portion provides a space between the top plate portion of the casing member and the main body portion of the antenna.

  Preferably, the area of the contact surface of the spacer portion with respect to the main body portion of the antenna is half of the total area of the main body portion of the antenna when viewed from the facing direction of the top plate portion of the casing member and the main body portion of the antenna. Small compared. This suppresses dielectric loss.

  The connection part of the antenna may extend along the top plate support part with a space provided between the connection part of the antenna and the top plate support part of the casing member. This suppresses dielectric loss.

  The main body of the antenna may include a through hole, and the antenna supporting portion may include an engaging pin portion that engages with the through hole. Thereby, the antenna can be fixed to the casing member.

  For example, the casing member may be a cap-shaped member.

  The wireless communication device may include a conductor plate provided on the cap-shaped member so as to close the internal space of the cap-shaped member and attached to the metal surface. In this case, the connecting portion of the antenna may be connected to the conductor plate.

  The antenna may be an inverted F antenna. In this case, the feeder line portion and the short-circuit line portion of the inverted F antenna may be connected to the conductor plate as the connecting portion.

  An article according to another aspect of the present invention is an article having a metal surface on at least a part thereof, and a wireless communication device attached to the metal surface, wherein the wireless communication device is spaced from the metal surface. A casing member including a top plate portion having opposite back surfaces, and a top plate support portion standing from the top plate portion to the back surface side, a main body portion provided on the back surface of the top plate portion of the casing member, and the main body Provided on the back surface of the top plate portion of the casing member, and an antenna provided with a connecting portion extending from the portion toward the metal surface and connected to the metal surface in a direct current manner or capacitively coupled, An RFIC chip to be connected, and the casing member further includes an antenna support portion that supports the main body portion of the antenna with a space provided between the top plate portion and the main body portion of the antenna.

  According to this aspect, in an article including a wireless communication device such as an RFID tag, a simple structure enables wireless communication even when attached to a metal surface of the article while protecting the RFIC chip and the antenna connected thereto. it can.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a perspective view of a wireless communication device according to an embodiment of the present invention attached to an article, and FIG. 2 is an exploded perspective view of the wireless communication device. 3 is a cross-sectional view of the wireless communication device. In the drawings, the XYZ coordinate system is for facilitating the understanding of the invention and does not limit the invention. The X-axis direction indicates the longitudinal direction of the RFID tag, the Y-axis direction indicates the width direction, and the Z-axis direction indicates the thickness direction.

  As shown in FIG. 1, the wireless communication device 10 according to the present embodiment is a so-called RFID (Radio-Frequency IDentification) tag, and is used in a state of being attached to a metal surface Wa of an article W such as a metal plate. It is possible RFID tag 10.

  As shown in FIGS. 2 and 3, in the case of the present embodiment, the RFID tag 10 includes a cap-shaped member 12, an antenna 14 and an RFIC (Radio-Frequency Integrated Circuit) module 16 provided in the cap-shaped member 12. And a conductor plate 18 that closes the internal space R of the cap-shaped member 12, and a seal member 20 provided on the conductor plate 18.

  The cap-shaped member 12 is a cap-shaped casing member that protects the antenna 14 and the RFIC module 16, and is made of, for example, a resin material such as polycarbonate, polypropylene, polyester, or polyether ether ketone. In the case of the present embodiment, the cap-shaped member 12 is provided with a flat plate-shaped top plate portion 12a and a cylindrical side wall portion 12b that stands upright from the outer peripheral edge of the top plate portion 12a. As shown in FIGS. 1 and 2, in the RFID tag 10, the flange-shaped tip surface (flange portion) 12c of the side wall portion 12b, that is, the opening edge portion 12c of the cap-shaped member 12 is attached to the metal surface Wa of the article W. It is attached via the seal member 20.

  By attaching the RFID tag 10 to the metal surface Wa of the article W via the side wall portion 12b as described above, the back surface 12d of the top plate portion 12a of the cap-shaped member 12 becomes the metal surface Wa, as shown in FIG. Face each other with a space in between. In the case of the present embodiment, the back surface 12d of the top plate portion 12a is parallel to the metal surface Wa. That is, the side wall portion 12b is erected from the top plate portion 12a to the back surface 12d side, and functions as a top plate support portion that supports the top plate portion 12a with a space left between the metal surface Wa.

  As shown in FIGS. 2 and 3, in the case of the present embodiment, the antenna 14 is provided on the back side of the cap-shaped member 12 (the surface of the cap-shaped member 12 that defines the internal space R). The antenna 14 is made of a conductor material such as brass plated with nickel/tin. The antenna 14 is produced, for example, by press-molding a metal sheet or a metal thin plate (punching and bending with a pressing machine).

  Further, the antenna 14 includes a main body 14a and a connecting portion 14b extending from the main body 14a. In the case of the present embodiment, the connecting portion 14b is connected to the metal surface Wa of the article W via the conductor plate 18. Note that further details of the antenna 14 will be described later.

  The RFIC module 16 is a module including an RFIC chip and a matching circuit for matching between the antenna 14 and an RFIC (Radio-Frequency Integrated Circuit) chip, and is connected to the antenna 14. The RFIC module 16 is provided on the back surface 12d of the top plate portion 12a of the cap-shaped member 12 via the antenna 14. Note that further details of the RFIC module 16 will be described later.

  The conductor plate 18 is a plate-shaped member made of a conductor material, is provided in the cap-shaped member 12, and closes the internal space R of the cap-shaped member 12 to form a closed space. The conductor plate 18 is also provided on the cap-shaped member 12 in parallel with the back surface 12d of the top plate portion 12a of the cap-shaped member 12. As a result, the antenna 14 and the RFIC module 16 are covered and protected by the cap-shaped member 12 and the conductor plate 18. Since the conductor plate 18 is connected to the connecting portion 14b of the antenna 14, it is preferably made of the same material as the antenna 14.

  The seal member 20 is a so-called double-sided tape, and is a member for attaching the RFID tag 10 to the metal surface Wa of the article W. One adhesive surface 20a of the seal member 20 is attached to the flange portion 12c of the cap-shaped member 12 and the conductor plate 18. The other adhesive surface 20b is attached to the metal surface Wa of the article W.

  From here, the features of the antenna 14, the RFIC module 16, and the RFID tag 10 related thereto will be described in detail.

  As shown in FIG. 3, the main body portion 14 a of the antenna 14 is attached to the back surface 12 d of the top plate portion 12 a of the cap-shaped member 12. Therefore, the cap-shaped member 12 is provided with a plurality of antenna support portions 12e on the back surface 12d of the top plate portion 12a.

  The antenna support portion 12e of the cap-shaped member 12 is configured to support the main body portion 14a of the antenna 14 with a space provided between the top plate portion 12a of the cap-shaped member 12 and the main body portion 14a of the antenna 14. Has been done.

  FIG. 4 is a perspective view showing the antenna support portion before supporting the antenna.

  As shown in FIGS. 3 and 4, in the case of the present embodiment, each of the plurality of antenna support portions 12e projects from the back surface 12d of the top plate portion 12a of the cap-shaped member 12 and contacts the main body portion 14a of the antenna 14. It includes a spacer portion 12g having a contact surface 12f. The protruding height of the spacer portion 12g (the distance from the back surface 12d of the top plate portion 12a to the contact surface 12f) is, for example, 0.2 mm.

  The main body portion 14a of the antenna 14 comes into contact with the contact surface 12f of the spacer portion 12g in each of the plurality of antenna support portions 12e, so that a space, that is, a dielectric, is formed between the main body portion 14a and the top plate portion 12a of the cap-shaped member 12. A layer of air with a rate of 1 is provided. Further, the main body portion 14b is provided parallel to the back surface 12d of the top plate portion 12a. The reason for providing such a space will be described later.

  In order to maintain the contact between the body portion 14a of the antenna 14 and the spacer portion 12g of the antenna support portion 12e, that is, to fix the antenna 14 to the cap-shaped member 12, in the case of the present embodiment, a plurality of antenna support portions are provided. Each 12e includes an engagement pin portion 12h. A plurality of through holes 14c engaged with the engagement pin portions 12h are formed in the main body portion 14a of the antenna 14.

  Specifically, in the case of the present embodiment, the engagement pin portion 12h has a pin shape protruding from the spacer portion 12g and passes through the through hole 14c formed in the main body portion 14a of the antenna 14. As shown in FIG. 3, the portion (head) of the engagement pin portion 12h that has passed through the through hole 14c is heated and deformed like the head of a rivet, so that the main body portion 14a of the antenna 14 is cap-shaped. It is fixed to the member 12. As a result, as shown in FIG. 3, the main body portion 14a of the antenna 14 is maintained in a posture parallel to the back surface 12d of the top plate portion 12a of the cap-shaped member 12 and also parallel to the conductor plate 18. To be done. The shape of the head of the engaging pin portion 12h after the deformation is preferably tapered so that the width becomes narrower as it goes away from the main body portion 14a of the antenna 14, and further, as shown in FIG. It is preferably head-shaped. Furthermore, it is preferable that the thickness of the head (the distance from the top of the head to the main body 14a of the antenna 14) is large. The reason for these is that, for example, when an external force is applied to the engagement pin portion 12h, the possibility that the head portion is damaged can be reduced (the external force can be dispersed). As a result, the main body portion 14a of the antenna 14 can be reliably fixed to the cap-shaped member 12, and the variation in frequency can be reduced.

  As shown in FIG. 4, in the case of the present embodiment, a columnar portion 12j is provided on the back surface 12d of the top plate portion 12a of the cap-shaped member 12 in addition to the antenna support portion 12e. The columnar portion 12j penetrates the main body portion 14a of the antenna 14, and its tip comes into contact with the conductor plate 18. As a result, the top plate portion 12 a of the cap-shaped member 12 is suppressed from bending toward the conductor plate 18.

  The conductor plate 18 is also fixed to the cap-shaped member 12 similarly to the main body portion 14a of the antenna 14. Therefore, as shown in FIG. 2, the conductor plate 18 is formed with a plurality of through holes 18a. Engaging pin portions (not shown) that engage with these through holes 18 a are provided in the cap-shaped member 12.

  As shown in FIGS. 2 and 3, in the case of the present embodiment, the connecting portion 14b of the antenna 14 is a portion for connecting the main body portion 14a and the conductor plate 18. That is, the connecting portion 14 b of the antenna 14 is connected to the metal surface Wa of the article W via the conductor plate 18 and the seal member 20. When the seal member 20 has conductivity, the antenna 14 is DC-connected to the metal surface Wa of the article W. On the other hand, when the seal member 20 has an insulating property, the antenna 14 is capacitively coupled to the metal surface Wa of the article W.

  In the case of the present embodiment, as shown in FIG. 2, the connection portion 14b of the antenna 14 extends from one end of the main body portion 14a in the longitudinal direction (X-axis direction) toward the metal surface Wa, that is, toward the conductor plate 18. It has been extended. Further, as shown in FIG. 3, the connecting portion 14b extends along the side wall portion 12b of the cap-shaped member 12. Specifically, the connection portion 14b extends along the side wall portion 12b with a space provided between the connection portion 14b and the side wall portion 12b. The reason for providing such a space will be described later.

  FIG. 5 is a perspective view showing the connection between the antenna and the conductor plate.

  As shown in FIG. 5, in the case of the present embodiment, the connecting portion 14b of the antenna 14 is provided on the conductor plate 18 via the strip-shaped terminal portion 14d extending in the width direction (Y-axis direction) of the RFID tag 10. It is provided on one end in the longitudinal direction (X-axis direction) and connected to a strip-shaped contact portion 18b extending in the width direction. A through hole 14e is formed in the terminal portion 14d of the antenna 14, and a through hole 18c is also formed in the contact portion 18b of the conductor plate 18. By engaging the engaging pin portions (not shown) formed in the cap-shaped member 12 with the through holes 14e and 18c overlapping each other, the contact between the terminal portion 14d of the antenna 14 and the contact portion 18b of the conductor plate 18 is made. Maintained. Alternatively, the terminal portion 14d of the antenna 14 and the contact portion 18b of the conductor plate 18 may be joined by soldering, for example. When these are joined by solder, the through hole 14e of the terminal portion 14d of the antenna 14 and the through hole 18c of the contact portion 18b of the conductor plate 18 may be omitted.

  Further, in the case of the present embodiment, in order to suppress the variation of the contact resistance between the terminal portion 14d of the antenna 14 and the contact portion 18b of the conductor plate 18 in the plurality of RFID tags 10, the contact portion 18b of the conductor plate 18 is suppressed. A plurality of convex portions 18d protruding toward the terminal portion 14d of the antenna 14 are formed on the. The contact portion 18b of the conductor plate 18 contacts the terminal portion 14d of the antenna 14 through the plurality of convex portions 18d. That is, by making point contact at a plurality of points, it is possible to suppress variations in contact resistance as compared with the case where the terminal portion 14d and the contact portion 18b are in surface contact. The convex portion may be provided on the antenna 14 instead of the conductor plate 18. Further, as described above, when the terminal portion 14d of the antenna 14 and the contact portion 18b of the conductor plate 18 are joined by solder, the convex portion may be omitted.

  Note that, as shown in FIG. 5, the length L1 of the terminal portion 14d of the antenna 14 is longer than the length L2 of the contact portion 18b of the conductor plate 18. As a result, as shown in FIG. 6, which is a bottom view of the RFID tag 10 before the seal member 20 is attached, part of the terminal portion 14d of the antenna 14 is exposed to the outside. The resistance between the terminal portion 14d of the antenna 14 and the contact portion 18b of the conductor plate 18 can be measured by bringing the probe of the tester into contact with the exposed portion of the terminal portion 14d of the antenna 14 and the conductor plate 18, respectively. it can. As a result, a contact failure between the antenna 14 and the conductor plate 18 can be detected.

  In the case of the present embodiment, the antenna 14 is a so-called inverted F antenna.

  FIG. 7 is an equivalent circuit diagram of the RFID tag according to this embodiment.

  FIG. 7 shows an equivalent circuit in the RFID tag 10 in a state where the seal member 20 has an insulating property and the conductor plate 18 and the metal surface Wa of the article W are capacitively coupled. As shown in FIG. 7, since the antenna 14 functions as an inverted F antenna, the radiating portion 14f that radiates radio waves, the feeding line portion 14g that connects the radiating portion 14f and the metal surface Wa of the article W, and the short-circuit wire. And a portion 14h.

  Specifically, as shown in FIG. 2, the radiating portion 14f of the antenna 14 is configured by the free end side portion (that is, the non-connecting portion side portion) of the main body portion 14a.

  As shown in FIGS. 5 and 7, the feeder line portion 14g of the antenna 14 includes a radiation side conductor wire portion 14j extending from the radiation portion 14f and a connection side conductor wire portion extending from the terminal portion 14d toward the radiation portion 14f. 14k, and the RFIC module 16 connected to the radiation side conductor portion 14j and the connection side conductor portion 14k. The connection side conductor portion 14k includes the connection portion 14b.

  The short-circuit wire portion 14h of the antenna 14 extends between the radiation portion 14f and the terminal portion 14d and connects them. The short-circuit wire portion 14h includes the connection portion 14b.

  Further, in the case of the present embodiment, two short-circuit wire portions 14h are provided with the power supply wire portion 14g sandwiched therebetween. The reason why there are two short-circuit wire portions 14h is that when the antenna 14 is press-molded, the connecting-side conductor wire portion 14k in the feeder line portion 14g is appropriately bent. Specifically, before the antenna 14 is bent, the connection-side conductor wire portion 14k is in the shape of an elongated strip extending linearly. If one of the two short-circuit wire portions 14h does not exist, the connecting-side conductor wire portion 14k may be twisted without being properly bent when the antenna 14 is bent. If twisted, the terminal portion 14d and the connection-side conductor portion 14k may be separated. Alternatively, there is a possibility that the connection-side conductive wire portion 14k and the RFIC module 16 will not be properly electrically connected in a later step. In order to suppress such twisting, the two short-circuit wire portions 14h sandwich the power supply wire portion 14g.

  Details of the RFIC module 16 included in the feeder line portion 14g of the antenna 14 will be described.

  FIG. 8 is an exploded perspective view of the RFIC module. FIG. 9 is an equivalent circuit diagram of the RFID module.

  As shown in FIGS. 8 and 9, the RFIC module 16 is a device that performs wireless communication at a communication frequency of 900 MHz band, that is, UHF band, for example.

  As shown in FIG. 8, in the case of the present embodiment, the RFIC module 16 is composed of a multi-layer substrate composed of three layers. Specifically, the RFIC module 16 is configured by laminating insulating sheets 32A, 32B, and 32C that are made of a resin material such as polyimide or liquid crystal polymer and have flexibility.

  As shown in FIG. 8, the RFIC module 16 includes an RFIC (Radio-Frequency Integrated Circuit) chip 34, a plurality of inductance elements 36A, 36B, 36C, and 36D, and external connection terminals 38 and 40. In the case of the first embodiment, the inductance elements 36A to 36D and the external connection terminals 38 and 40 are formed on the insulating sheets 32A to 32C and are composed of a conductor pattern made of a conductive material such as copper.

  As shown in FIG. 8, the RFIC chip 34 is mounted on the central portion of the insulating sheet 32C in the longitudinal direction (X-axis direction). The RFIC chip 34 has a structure in which various elements are built in a semiconductor substrate made of a semiconductor such as silicon. Further, the RFIC chip 34 includes a first input/output terminal 34a and a second input/output terminal 34b. Further, as shown in FIG. 9, the RFIC chip 34 includes an internal capacitance (capacitance: self capacitance of the RFIC chip itself) C1.

  As shown in FIG. 8, the inductance element (first inductance element) 36A is formed on one side in the longitudinal direction (X-axis direction) of the insulating sheet 32C from a conductor pattern provided in a spiral coil shape on the insulating sheet 32C. It is configured. Further, as shown in FIG. 9, the inductance element 36A includes an inductance L1. A land 36Aa connected to the first input/output terminal 34a of the RFIC chip 34 is provided at one end (end outside the coil) of the inductance element 36A. The land 36Ab is also provided at the other end (end on the coil center side).

  As shown in FIG. 8, the inductance element (second inductance element) 36B is formed on the other side of the insulating sheet 32C in the longitudinal direction (X-axis direction) from a conductor pattern provided in a spiral coil shape on the insulating sheet 32C. It is configured. Further, as shown in FIG. 9, the inductance element 36B includes an inductance L2. A land 36Ba connected to the second input/output terminal 34b of the RFIC chip 34 is provided at one end (end outside the coil) of the inductance element 36A. The land 36Bb is also provided at the other end (the end on the coil center side).

  As shown in FIG. 8, the inductance element (third inductance element) 36C is formed from a conductor pattern provided in a spiral coil shape on the insulating sheet 32B on one side in the longitudinal direction (X-axis direction) of the insulating sheet 32B. It is configured. The inductance element 36C faces the inductance element 36A in the stacking direction (Z-axis direction). Further, as shown in FIG. 9, the inductance element 36C includes an inductance L3. A land 36Ca is provided at one end (end on the coil center side) of the inductance element 36C. The land 36Ca is connected to the land 36Ab of the inductance element 36A on the insulating sheet 32C via an interlayer connecting conductor 42 such as a through-hole conductor penetrating the insulating sheet 32B.

  As shown in FIG. 8, the inductance element (fourth inductance element) 36D is formed on the other side in the longitudinal direction (X-axis direction) of the insulating sheet 32B from a conductor pattern provided in a spiral coil shape on the insulating sheet 32B. It is configured. The inductance element 36D faces the inductance element 36B in the stacking direction (Z-axis direction). Further, as shown in FIG. 9, the inductance element 36D includes an inductance L4. A land 36Da is provided at one end (end on the coil center side) of the inductance element 36D. The land 36Da is connected to the land 36Bb of the inductance element 36B on the insulating sheet 32C via an interlayer connecting conductor 44 such as a through-hole conductor penetrating the insulating sheet 32B.

  The inductance elements 36C and 36D on the insulating sheet 32B are integrated as one conductor pattern. That is, the other ends (ends outside the coil) are connected to each other. Further, the insulating sheet 32B is formed with a through hole 32Ba in which the RFIC chip 34 mounted on the insulating sheet 32C is accommodated.

  As shown in FIG. 8, the external connection terminals 38 and 40 are composed of a conductor pattern provided on the insulating sheet 32A. In addition, the external connection terminals 32 and 40 face each other in the longitudinal direction (X-axis direction) of the insulating sheet 32A.

  One external connection terminal 38 is connected to the land 36Ca of the inductance element 36C on the insulating sheet 32B via an interlayer connecting conductor 46 such as a through-hole conductor that penetrates the insulating sheet 32A.

  The other external connection terminal 40 is connected to the land 36Da of the inductance element 36D on the insulating sheet 32B via an interlayer connecting conductor 48 such as a through-hole conductor penetrating the insulating sheet 32A.

  One of the external connection terminals 38 is connected to the connection-side conductor wire portion 14k in the feeder wire portion 14g of the antenna 14 via, for example, solder. Similarly, the other external connection terminal 40 is connected to the radiation side conductor portion 14j via, for example, solder.

  The RFIC chip 34 is composed of a semiconductor substrate. The RFIC chip 34 exists between the inductance elements 36A and 36B and between the inductance elements 36C and 36D. By the RFIC chip 34 functioning as a shield, magnetic field coupling and capacitive coupling between the spiral coil-shaped inductance elements 36A and 36B provided on the insulating sheet 32C are suppressed. Similarly, magnetic field coupling and capacitive coupling between the spiral coil-shaped inductance elements 36C and 36D provided on the insulating sheet 32B are suppressed. As a result, narrowing of the pass band of the communication signal is suppressed.

  As shown in FIG. 9, a matching circuit for matching between the RFIC chip 34 and the antenna 14 at the communication frequency by the capacitance C1 (internal capacitance of the RFIC chip 34) and the inductances L1 to L4 (inductances of four inductance elements). Is configured.

  According to the configurations described so far, when the RFID tag 10 is not attached to the metal surface Wa of the article W, the RFID tag 10 is attached to the one metal surface Wa substantially through the radiation portion 14f of the antenna 14. When it is present, radio waves are exchanged with an external wireless communication device (for example, a reader/writer device) substantially through the radiator 14f and the metal surface Wa.

  For example, when a radio wave is received via the radiating portion 14f of the antenna 14 or the metal surface Wa, an electromotive force is generated in these and the RFIC chip 34 of the RFIC module 16 is driven by the electromotive force. The driven RFIC chip 34 transmits the data stored in the storage unit via the radiation unit 14f or the metal surface Wa.

  Further, as shown in FIG. 3, since the main body portion 14a of the antenna 14, particularly the radiation portion 14f faces each other via the air layer in the internal space R of the cap-shaped member 12, the radiation portion 14f and the conductor plate 18 are separated from each other. The capacity formed between them is sufficiently small and does not substantially affect the communication characteristics, particularly the communication distance and communication frequency. Thereby, the distance between the radiating part 14f and the conductor plate 18 can be made as small as possible within a range that does not substantially affect the communication characteristics. Thereby, the RFID tag 10 can be thinned.

  Further, as shown in FIG. 3, even when the RFID tag 10 is attached to the metal surface Wa of the article W, the radiating portion 14f of the antenna 14 faces the metal surface Wa with the conductor plate 18 in between, so the RFID tag 10 The communication characteristics of (1) and (2) in particular are substantially the same as those before attachment to the metal surface Wa. By electrically connecting or capacitively coupling the metal surface Wa and the conductor plate 18 to each other, radio waves can be transmitted and received through the metal surface Wa.

  Furthermore, as shown in FIG. 3, the main body portion 14a and the connecting portion 14b of the antenna 14 are provided on the cap-shaped member 12 with a space provided between the main body portion 14a and the connection portion 14b. That is, an air layer is provided between the main body portion 14a of the antenna 14 and the top plate portion 12a of the cap-shaped member 12, and an air layer is provided between the connection portion 14b and the side wall portion 12b. This suppresses the dielectric loss, that is, a part of the current flowing through the antenna 14 is converted into heat and lost (compared to the case where there is no space). By suppressing the dielectric loss, it is possible to suppress the deterioration of communication characteristics. For example, the reduction of the communication distance and the shift of the peak of the communication frequency are suppressed. For example, the peak of 920 MHz is suppressed from shifting to 900 MHz.

  In order to further suppress the dielectric loss, it is preferable that the contact area of the cap-shaped member 12 with the main body portion 14a of the antenna 14 is small. In the case of the present embodiment, when the top plate portion 12a of the cap-shaped member 12 and the main body portion 14a of the antenna 14 are viewed in the facing direction (Z-axis direction), the contact surface 12f of the spacer portion 12g with respect to the main body portion 14a of the antenna 14 is formed. The area (total area) is preferably smaller than half the total area of the main body 14a of the antenna 14.

  However, if the contact area of the cap-shaped member 12 with respect to the main body portion 14a of the antenna 14 is made too small, the main body portion 14a of the antenna 14 is insufficiently supported, and as a result, the main body portion 14a is bent, and as a result, the conductor plate 18 is not supported. The main body 14a of the antenna 14 may not be maintained in parallel.

  According to the present embodiment as described above, in the RFID tag 10, the RFIC chip 34 (RFIC module 16) and the antenna 14 connected to the RFID tag 10 (RFIC module 16) can be wirelessly communicated even when attached to the metal surface Wa with a simple structure. Can be protected.

  Specifically, the RFIC module 16 including the RFIC chip 34 and the antenna 14 connected to the RFIC module 16 are directly provided on the cap-shaped member 12 for protecting them. That is, the cap-shaped member 12 is a member that protects the RFIC module 16 and the antenna 14 as well as a member that holds them. Therefore, for example, it is not necessary to provide the RFIC chip 34 and the antenna 14 on a substrate, a block, etc., and to protect the substrate, the block, etc. with a protective case.

  Further, since the main body portion 14a (radiating portion 14f) of the antenna 14 is provided in the cap-shaped member 12 with a space provided between the main body portion 14a and the cap-shaped member 12, the dielectric loss is suppressed, and as a result, the communication characteristic The decrease is suppressed.

  Although the present invention has been described with reference to the above embodiment, the embodiment of the present invention is not limited to this.

  For example, in the case of the above-described embodiment, the RFIC chip 34 is installed in the RFIC module 16 together with the matching circuits (four inductance elements 36A to 36D) that match the RFIC chip 34 and the antenna 14, and the antenna 14 It is connected to the. However, the embodiment of the present invention is not limited to this.

  FIG. 10 is an exploded perspective view of an RFID tag according to another embodiment. The constituent elements substantially the same as those in the above-described embodiment are designated by the same reference numerals. Therefore, an RFID tag according to another embodiment will be described with reference to FIG. 10 focusing on the points different from the above-described embodiment.

  As shown in FIG. 10, in the RFID tag 110 according to another embodiment, the RFIC chip 34 is provided in the main body 114a of the inverted F antenna-shaped antenna 114 without being modularized. Specifically, the first input/output terminal of the RFIC chip 34 is connected to the connection-side conductor portion 114k in the feeder line portion of the antenna 114, and the second input/output terminal is connected to the radiation-side conductor portion 114j. The antenna 114 and the RFIC chip 34 can be matched with each other by setting the connecting-side conductor portion 114k to an appropriate length, that is, by adjusting the inductance of the connecting-side conductor portion 114k.

  Further, as shown in FIG. 4, in the case of the above-described embodiment, in the antenna supporting portion 12e of the cap-shaped member 12, a spacer portion for providing a space between the main body portion 14a of the antenna 14 and the cap-shaped member 12. 12g and an engaging pin portion 12h for fixing the antenna 14 to the cap-shaped member 12 are integrated. Instead of this, in the antenna support portion, the spacer portion 12g and the engagement pin portion 12h may be provided at different places and separated from each other. Further, the numbers of the spacer portions 12g and the engaging pin portions 12h may be different. The number of engaging pin portions 12h that can be fixed to the cap-shaped member 12 is such that the entire main body portion 14a of the antenna 14 is maintained parallel to the back surface 12d of the top plate portion 12a of the cap-shaped member 12. It may be any number, and may be six, for example. That is, the antenna support may be of any form as long as a space can be provided between the main body of the antenna and the top plate of the casing member.

  Further, as shown in FIG. 3, in the case of the above-described embodiment, in the RFID tag 10, the connecting portion 14b of the antenna 14 is DC-connected to the metal surface Wa of the article W via the conductor plate 18. Or capacitively couple. Alternatively, the antenna connection may be galvanically or capacitively coupled to the metal surface of the article without the intermediary of a conductor plate. In this case, the RFID tag can omit the conductor plate.

  Furthermore, as shown in FIG. 1, in the case of the above-described embodiment, the casing member that protects and holds the RFIC chip 34 (RFIC module 16) and the antenna 14 has a cap shape that defines a sealed internal space R. Not limited to For example, the casing member may include a hole that connects the internal space and the outside when attached to a metal surface. For example, the top plate supporting portion of the casing member may be two flat plate-shaped side wall portions that are parallel to each other. Further, for example, the top plate supporting portion may be four pillar portions (in this case, the casing member has a table shape).

  In addition, although the metal surface Wa of the article W to which the RFID tag 10 is attached is a flat surface as shown in FIG. 1, the embodiment according to the present invention is not limited to this. For example, the metal surface may be a curved surface such as a gas cylinder. In this case, the casing member has flexibility. Alternatively, when the casing member is a cap-shaped member, its opening edge portion has a shape capable of engaging with the curved surface.

  That is, the wireless communication device according to the embodiment of the present invention can be used even when attached to various articles provided with a metal surface of an arbitrary shape, for example, a metal surface such as an office desk or a drum can, and a non-metal surface. It can also be used by attaching to.

  In addition, as shown in FIG. 7, in the above-described embodiment, the antenna 14 is in the form of an inverted F antenna, but is not limited to this. For example, an inverted L antenna may be used.

  For example, the wireless communication device may be configured to detect at least one of the ambient temperature and humidity and output the detection result to the outside. For example, a temperature sensor and a humidity sensor are incorporated in the RFIC chip. Alternatively, a temperature sensor and a humidity sensor are provided in the RFIC module together with the RFIC chip.

  Since the RFIC module with the temperature sensor is provided on the back surface of the top plate portion of the cap-shaped member, the temperature sensor can detect the temperature outside the cap-shaped member with high accuracy. More specifically, the temperature sensor indirectly detects the outside temperature by substantially detecting the temperature of the cap-shaped member that is in contact with the outside air. Therefore, unlike this, even if the external temperature changes drastically in a short time, the temperature sensor is higher than when the module with the temperature sensor is installed away from the cap-shaped member through the space. The external temperature can be detected accurately.

  When the humidity sensor is provided in the RFIC module, the cap-shaped member is provided with a communication hole for communicating the internal space with the outside.

  That is, the wireless communication device according to the embodiment of the present invention is, in a broad sense, a wireless communication device that can be used while being attached to a metal surface of an article, and is opposed to the metal surface with a space. And a casing member including a top plate portion provided with a back surface, and a top plate support portion standing from the top plate portion to the back surface side, a main body portion provided on the back surface of the top plate portion of the casing member, and the main body portion. From the antenna provided with a connecting portion extending from the above toward the metal surface for direct current connection or capacitive coupling to the metal surface, and provided on the back surface of the top plate portion of the casing member and connected to the antenna. And an RFIC chip, and the casing member further includes an antenna support portion that supports the main body portion of the antenna with a space provided between the top plate portion and the main body portion of the antenna.

  It should be noted that although some embodiments of the present invention are mentioned, a further embodiment according to the present invention can be obtained by combining at least one embodiment with another embodiment in whole or in part. It is obvious to those skilled in the art that it is possible to do so.

  INDUSTRIAL APPLICABILITY The present invention is applicable to wireless communication devices such as RFID tags that can be attached to a metal surface and used.

10 Wireless communication device (RFID tag)
12 Casing member (cap-shaped member)
12a Top plate part 12b Top plate support part (side wall part)
12e Antenna support part 14 Antenna 14a Main body part 14b Connection part 16 RFIC chip (RFIC module)
W article Wa metal surface

Claims (9)

A wireless communication device that can be used while attached to a metal surface of an article,
A casing member including a top plate portion having a back surface opposed to the metal surface with a space, and a top plate support portion standingly provided on the back surface side from the top plate portion,
An antenna including a main body portion provided on the back surface of the top plate portion of the casing member, and a connecting portion that extends from the main body portion toward the metal surface and is DC-connected or capacitively coupled to the metal surface. When,
Provided on the back surface of the top plate of the casing member, and having an RFIC chip connected to the antenna,
The casing member further includes an antenna support portion that supports the main body portion of the antenna with a space provided between the top plate portion and the main body portion of the antenna,
Wireless communication device. The antenna support portion includes a spacer portion that protrudes from the back surface of the top plate portion of the casing member and has a contact surface that contacts the main body portion of the antenna.
The wireless communication device according to claim 1. The area of the contact surface of the spacer portion with respect to the main body portion of the antenna is smaller than half the total area of the main body portion of the antenna when viewed from the opposite direction of the top plate portion of the casing member and the main body portion of the antenna. ,
The wireless communication device according to claim 2. The connecting portion of the antenna extends along the top plate supporting portion with a space provided between the antenna member and the top plate supporting portion of the casing member,
The wireless communication device according to any one of claims 1 to 3. The body of the antenna includes a through hole,
The antenna support portion includes an engagement pin portion that engages with the through hole,
The wireless communication device according to any one of claims 1 to 4. The casing member is a cap-shaped member,
The wireless communication device according to claim 1. A conductor plate that is provided on the cap-shaped member so as to close the internal space of the cap-shaped member, and is attached to the metal surface;
The connecting portion of the antenna is connected to the conductor plate,
The wireless communication device according to claim 6. The antenna is an inverted F antenna,
The wireless communication device according to claim 7, wherein the feed line portion and the short-circuit line portion of the inverted F antenna are connected to the conductor plate as the connection portion. An article having a metal surface on at least a part thereof, wherein the wireless communication device is attached to the metal surface,
The wireless communication device,
A casing member including a top plate portion having a back surface opposed to the metal surface with a space therebetween, and a top plate support portion standingly provided on the back surface side from the top plate portion,
An antenna including a main body portion provided on the back surface of the top plate portion of the casing member, and a connecting portion that extends from the main body portion toward the metal surface and is DC-connected or capacitively coupled to the metal surface. When,
Provided on the back surface of the top plate of the casing member, and having an RFIC chip connected to the antenna,
The casing member further includes an antenna support portion that supports the main body portion of the antenna with a space provided between the top plate portion and the main body portion of the antenna,
Goods.

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