RFID Label

Abstract

An RFID tag that has the following features: a base material comprising a first surface and a second surface opposite the first surface; a coil conductor comprising a first spiral conductor provided on the first surface of the base material, a second spiral conductor provided on the second surface of the base material, and an interlayer connection conductor extending through the base material and electrically connecting one end of the first spiral conductor and one end of the second spiral conductor; an RFIC chip provided on the base material such that the RFIC chip is positioned in an opening of the coil conductor in a plan view of the base material, and comprising a first terminal and a second terminal; a first connecting conductor provided on the first surface of the base material and electrically connecting another end of the first spiral conductor and the first terminal of the RFIC chip; and a second connecting conductor provided on the second surface of the base material and electrically connecting another end of the second spiral conductor and the second terminal of the RFIC chip, wherein the first connecting conductor and the second connecting conductor at least partially overlap in a plan view of the base material.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to an RFID tag. TECHNICAL BACKGROUND

[0002] For example, as described in Patent Document 1, an RFID tag is known that includes an RFIC chip and a coil conductor electrically connected to the RFIC chip and used as an antenna. The RFIC chip is arranged in an opening of the coil conductor. PRIOR ART DOCUMENT PATENT DOCUMENT

[0003] Patent Document 1: JP-A-2008-244740 SUMMARY OF THE INVENTION PROBLEM TO BE SOLVED BY THE INVENTION

[0004] In the RFID tag described in Patent Document 1, a first connecting conductor that electrically connects one end of the coil conductor and the RFIC chip, and a second connecting conductor that electrically connects another end of the coil conductor and the RFIC chip, respectively, extend in opposite directions with respect to the RFIC chip. In this case, a magnetic flux generated by a current flowing through the first connecting conductor, the RFIC chip, and the second connecting conductor, as well as a part of a magnetic flux generated by a current flowing through the coil conductor and passing through the opening of the coil conductor, cancel each other out. Consequently, a communication distance of the RFID tag is shortened.

[0005] Therefore, the present disclosure provides an RFID tag comprising a coil conductor and an RFIC chip disposed in an opening of the coil conductor. The RFID tag prevents a communication distance from decreasing while the coil conductor and the RFIC chip are electrically connected. SOLUTION TO THE PROBLEM

[0006] To solve the above problem, according to one aspect of the present invention, an RFID tag is provided which comprises the following features: a base material comprising a first surface and a second surface opposite the first surface; a coil conductor comprising a first spiral conductor provided on the first surface of the base material, a second spiral conductor provided on the second surface of the base material, and an interlayer connection conductor extending through the base material and electrically connecting one end of the first spiral conductor and one end of the second spiral conductor; an RFIC chip provided on the base material such that the RFIC chip is positioned in an opening of the coil conductor in a plan view of the base material, and comprising a first terminal and a second terminal; a first connecting conductor provided on the first surface of the base material and electrically connecting another end of the first spiral conductor and the first terminal of the RFIC chip; and a second connecting conductor provided on the second surface of the base material and electrically connecting another end of the second spiral conductor and the second terminal of the RFIC chip, wherein the first connecting conductor and the second connecting conductor at least partially overlap in a plan view of the base material. EFFECTS OF THE INVENTION

[0007] According to the present disclosure, with the RFID tag including the coil conductor and the RFIC chip arranged in the opening of the coil conductor, a communication distance can be prevented from decreasing while the coil conductor and the RFIC chip are electrically connected. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view of an RFID tag according to a first embodiment of the present disclosure. Fig. 2 is a plan view of the RFID tag according to the first embodiment. Fig. 3 is an exploded perspective view of the RFID tag according to the first embodiment. Fig. 4 is a schematic view of an RFID tag of a first comparative example. Fig. 5 is a schematic view of an RFID tag of a first example. Fig. 6 is a plan view of an RFID tag of a second comparative example. Fig. 7 is an exploded perspective view of the RFID tag of the second comparative example. Fig. 8 is a plan view of an RFID tag of a second example. Fig. 9 is an exploded perspective view of the RFID tag of the second example. Fig. 10 is a perspective view of an RFID tag according to a second embodiment of the present disclosure. Fig. 11 is a plan view of the RFID tag according to the second embodiment. Fig. 12 is an exploded perspective view of the RFID tag according to the second embodiment. Fig. 13 is a perspective view of an RFID tag according to a third embodiment of the present disclosure. Fig. 14 is a plan view of the RFID tag according to the third embodiment. Fig. 15 is an exploded perspective view of the RFID tag according to the third embodiment. DETAILED DESCRIPTION

[0008] In the following, embodiments of the present disclosure will be described with reference to the drawings. First embodiment

[0009] Fig. 1 is a perspective view of an RFID tag according to a first embodiment of the present disclosure. Fig. 2 is a plan view of the RFID tag according to the first embodiment. Fig. Figure 3 is an exploded perspective view of the RFID tag according to the first embodiment. Note that an orthogonal XYZ coordinate system is provided in the drawings to facilitate understanding of the present disclosure and does not limit the present disclosure. An X-axis direction indicates a width direction of an RFID tag, a Y-axis direction indicates a depth direction, and a Z-axis direction indicates a thickness direction.

[0010] As in Fig. 1 to 3, a radio frequency identification (RFID) tag (or an RFID tag) 10 according to the first embodiment includes a base material 12, a radio frequency integrated circuit (RFIC) chip 14 provided on the base material 12, and a coil conductor 16 electrically connected to the RFIC chip 14.

[0011] The base material 12 is a sheet-like member made of an insulating material and including a first surface 12a and a second surface 12b, which is a surface opposite to the first surface 12a.

[0012] The RFIC chip 14 is configured to perform wireless communication with an external device using the coil conductor 16. The RFIC chip 14 includes first and second terminals 14a and 14b electrically connected to the coil conductor 16.

[0013] In the case of the first embodiment, the RFIC chip 14 is provided on the first surface 12a of the base material 12. Specifically, the first surface 12a of the base material 12 is provided with a first pad conductor 18 electrically connected to one end of the coil conductor 16 and a second pad conductor 20 electrically connected to another end of the coil conductor 16. These first and second pad conductors 18 and 20 are, for example, conductor structures (or conductor patterns).

[0014] The first terminal 14a of the RFIC chip 14 points to the first pad conductor 18 and is fixed while being electrically connected to the first pad conductor 18, for example, via a solder material. The second terminal 14b of the RFIC chip 14 points to the second pad conductor 20 and is fixed while being electrically connected to the second pad conductor 20, for example, via a solder material.

[0015] The coil conductor 16 acts as an antenna when the RFIC chip 14 performs wireless communication with an external device.

[0016] In the case of the first embodiment, the coil conductor 16 includes a first spiral conductor 22 provided on the first surface 12a of the base material 12 and a second spiral conductor 24 provided on the second surface 12b of the base material 12. When viewed from a plan view (when viewed in the Z-axis direction) of the base material 12, the first spiral conductor 22 and the second spiral conductor 24 partially overlap each other. These first and second spiral conductors 22 and 24 are, for example, conductor patterns (conductor structures).

[0017] In the case of the first embodiment, the coil conductor 16 includes an interlayer connection conductor 26, such as a through-hole conductor, which extends in the thickness direction (Z-axis direction) through the base material 12 and which electrically connects one end 22a of the first spiral conductor 22 and one end 24a of the second spiral conductor 24.

[0018] As in Fig. As illustrated in Figure 2, the RFIC chip 14, the first land conductor 18, and the second land conductor 20 are arranged in an opening 16a of the coil conductor 16 in a plan view (as viewed in the Z-axis direction) of the base material 12. Specifically, the RFIC chip 14 is arranged at a center of the opening 16a.

[0019] A first connecting conductor 28 is provided on the first surface 12a of the base material 12 to electrically connect another end 22b of the first spiral conductor 22 in the coil conductor 16 and the first pad conductor 18. The first connecting conductor 28 is, for example, a conductor pattern.

[0020] A second connecting conductor 30 is provided on the second surface 12b of the base material 12 to electrically connect another end 24b of the second spiral conductor 24 in the coil conductor 16 and the second pad conductor 20. The second connecting conductor 30 is, for example, a conductor pattern.

[0021] These first and second connecting conductors 28 and 30 enable the RFIC chip 14 and the coil conductor 16 to be electrically connected.

[0022] As in Fig. 2, the first connection conductor 28 and the second connection conductor 30 are provided on the first and second surfaces 12a and 12b of the base material 12, respectively, so as to at least partially overlap each other in a plan view (as viewed in the Z-axis direction) of the base material 12. More preferably, the first and second connection conductors 28 and 30 are provided on the base material 12 so that as many portions as possible overlap each other. In the case of the first embodiment, respective portions 28a and 30a that overlap each other of the first connection conductor 28 and the second connection conductor 30 extend linearly in an identical direction. The reason why the first connection conductor 28 and the second connection conductor 30 at least partially overlap each other will be described later.

[0023] In the case of the first embodiment, a land holding conductor 34, which holds the first land conductor 18 and the second land conductor 20, is provided on the second surface 12b of the base material 12. In the case of the first embodiment, the land holding conductor 34 is part of the second connection conductor 30.

[0024] The land holding conductor 34 overlaps the first land conductor 18 and the second land conductor 20 in a plan view (as viewed in the Z-axis direction) of the base material 12. That is, the first land conductor 18 and the second land conductor 20 are positioned in an outline of the land holding conductor 34 in a plan view of the base material 12.

[0025] This land holding conductor 34 serves to prevent the occurrence of electrical disconnection between the first and second land conductors 18 and 20 and the RFIC chip 14. The reason for this is as follows: The second spiral conductor 24 provided on the surface 12b of the base material 12 has a certain conductor thickness (for example, a thickness of 20 μm), and this thickness causes the first and second land conductors 18 and 20 to float in the air. However, with the presence of the land holding conductor 34, the first and second land conductors 18 and 20 are aligned with each other, thus preventing them from floating in the air.In the case of a solder connection, a solder is applied without diverting the base material 12 depending on a pressure condition of a solder squeegee, so that no connection failure occurs between the RFIC chip 14 and the first and second land conductors 18 and 20.

[0026] For example, when the RFID tag 10 is attached to a surface of an object on the second surface 12b of the base material 12, if the land support conductor 34 is present, a distance from the first land conductor 18 to the object is equal to the distance from the second land conductor 20 to the object. Thus, the RFID tag 10 can be attached to the object without the RFIC chip 14 tilting.

[0027] In contrast, when the land holding conductor 34 is not present, the first and second land conductors 18 and 20 are connected to the RFIC chip 14 while floating in the air due to the conductor thickness of the second spiral conductor 24 provided on the surface 12b of the base material 12. Thus, the heights of the first and second land conductors 18 and 20 cannot be maintained constant. In the case of a solder connection, a solder is applied while the base material 12 is deflected depending on a pressure condition of a soldering squeegee, so that an amount of solder becomes uneven, and consequently, a connection failure occurs between the RFIC chip 14 and the first and second land conductors 18 and 20. A similar connection failure may occur in the case of an IC connection under load, such as an ACP connection and ultrasonic welding.

[0028] Furthermore, when the RFID tag 10 is attached to a surface of an object on the second surface 12b of the base material 12, the second pad conductor 20 points to the second connection conductor 30, while no conductor pointing to the first pad conductor 18 is present on the second surface 12b of the base material 12. This causes the RFIC chip 14 to tilt when the RFID tag 10 is attached to the surface of the object. The reason for this is that, due to the absence of the pad support conductor 34, the distance from the first pad conductor 18 to the object is smaller than the distance from the second pad conductor 20 to the object. The tilt of the RFIC chip 14 may, for example, sever the electrical connection between the second terminal 14b and the second pad conductor 20.

[0029] The configuration of the RFID tag 10 according to the first embodiment has been described above. The following describes the reasons why the first connection conductor 28 and the second connection conductor 30 are arranged in a plan view (as viewed in the Z-axis direction) of the base material 12 as shown in FIG. Fig. 2, at least partially overlap.

[0030] Fig. 4 is a schematic view of an RFID tag of a first comparative example. Fig. Figure 5 is a schematic view of an RFID tag of a first example. Fig. The RFID label shown in Figure 5 corresponds to a simplified form of the RFID label 10 according to the first embodiment shown in Fig. 1 to Fig. 3 is shown.

[0031] As in Fig. As shown in Figure 4, an RFID tag 110 of the first comparative example includes a coil conductor 116 and an RFIC chip 114 disposed in an opening 116a of the coil conductor 116. The RFID tag 110 also includes a first connecting conductor 128 that electrically connects one end of the coil conductor 116 and the RFIC chip 114, and a second connecting conductor 130 that electrically connects another end of the coil conductor 116 and the RFIC chip 114. In the RFID tag 110 of the first comparative example, the first and second connecting conductors 128 and 130 extend from the RFIC chip 114 in opposite directions and do not overlap each other in a plan view.

[0032] As in Fig. As shown in Figure 4, in the RFID tag 110 of the comparative example, a current i1 flows through the coil conductor 116 to generate a magnetic flux f1. In addition, a magnetic flux f2 is generated by a current i2 flowing through the first connection conductor 128, the RFIC chip 114, and the second connection conductor 130. Note that the current i1 and the current i2 are the same current.

[0033] The magnetic flux f2 generated by the current i2 flowing through the first connecting conductor 128, the RFIC chip 114, and the second connecting conductor 130, and a portion of the magnetic flux f1 passing through the opening 116 of the coil conductor 16, cancel each other out. Consequently, the communication distance of the RFID tag 110, which performs wireless communication using the coil conductor 116, is shortened.

[0034] For an RFID label 210 of the first example, which is Fig. 5, on the other hand, a first connection conductor 228 and a second connection conductor 230 extend linearly from an RFIC chip 214 in an identical direction and partially overlap each other (since the first connection conductor 228 and the second connection conductor 230 cannot be distinguished when overlapped, Fig. 5 a non-overlapping state).

[0035] As in Fig. As shown in Figure 5, in the RFID tag 210 of the first example, a current i1 flows through a coil conductor 216 to generate a magnetic flux f1. In addition, a magnetic flux is generated by a current i2 flowing through the first connection conductor 228, the RFIC chip 214, and the second connection conductor 230. However, since a direction of the current i2 flowing through the first connection conductor 228 and a direction of the current i2 flowing through the second connection conductor 230 are opposite, a magnetic flux generated by the first connection conductor 228 and a magnetic flux generated by the second connection conductor 230 cancel each other.

[0036] Consequently, the magnetic flux f1 flowing through an opening 216a of the coil conductor 216 is substantially not canceled by the magnetic fluxes generated by the first and second connecting conductors 228 and 230. Therefore, a communication distance of the RFID tag 210 of the first example increases compared to the communication distance of the RFID tag 110 of the first comparative example.

[0037] The inventor verified this effect through simulation.

[0038] Fig. 6 is a plan view showing a model of an RFID tag of a second comparative example used for the simulation. Fig. 7 is an exploded perspective view showing the model of the RFID tag of the second comparative example. Fig. 8 is a plan view showing a model of an RFID tag of a second example used for the simulation. Fig. 9 is an exploded perspective view showing the model of the RFID tag of the second example.

[0039] As in Fig. 6 and Fig. 7, in an RFID tag 310 of the second comparative example, a coil conductor 316 includes a first spiral conductor 322 provided on a first surface 312a of the base material 312 and a second spiral conductor 324 provided on a second surface 312b. The coil conductor 316 also includes an interlayer connection conductor 326 that electrically connects an outer end of the first spiral conductor 322 and an outer end of the second spiral conductor 324. An RFIC chip 314 is arranged at a center of an opening 316a of the coil conductor 316 in a plan view (as viewed in the Z-axis direction) of the base material 312. A first terminal 314a of the RFIC chip 314 is electrically connected to an inner end of the first spiral conductor 322 via a first connection conductor 328.A second terminal 314b of the RFIC chip 314 is electrically connected to an inner end of the second spiral conductor 324 via a second connection conductor 330 and an interlayer connection conductor 332.

[0040] As in Fig. 6, in the RFID tag 310 of the second comparative example, the first connection conductor 328 and the second connection conductor 330 do not overlap each other in a plan view (as viewed in the Z-axis direction) of the base material 312.

[0041] As in Fig. 8 and Fig. On the other hand, as shown in FIG. 9, in an RFID tag 410 of the second example, a coil conductor 416 includes a first spiral conductor 422 provided on a first surface 412a of a base material 412, and a second spiral conductor 424 provided on a second surface 412b. The coil conductor 416 includes an interlayer connection conductor 426 that electrically connects an outer end of the first spiral conductor 422 and an outer end of the second spiral conductor 424. An RFIC chip 414 is arranged at a center of an opening 416a of the coil conductor 416 in a plan view (as viewed in the Z-axis direction) of the base material 412. A first terminal 414a of the RFIC chip 414 is electrically connected to an inner end of the first spiral conductor 422 via a first connection conductor 428.A second terminal 414b of the RFIC chip 414 is electrically connected to an inner end of the second spiral conductor 424 via a second interconnect conductor 430 and an interlayer interconnect conductor 432.

[0042] As in Fig. 8, in the RFID tag 410 of the second example, the first connection conductor 428 and the second connection conductor 430 partially overlap each other in a plan view (as viewed in the Z-axis direction) of the base material 412.

[0043] Note that the base material 312 and the RFIC chip 314 of the second comparative example are the same as the base material 412 and the RFIC chip 414 of the second comparative example. In addition, the material of the conductor, such as the coil conductor 316, of the second comparative example is the same as the material of the conductor, such as the coil conductor 416, of the second comparative example. Under these conditions, the inventors conducted the simulation to obtain the respective communication distances of the RFID tag 310 of the second comparative example and the RFID tag 410 of the second comparative example.

[0044] As a result of the simulation, the communication distance of the RFID tag 310 of the second comparative example was 10.5 mm, and the communication distance of the RFID tag 410 of the second example was 12.5 mm. This simulation result shows that the communication distance of the RFID tag is improved when the first connection conductor and the second connection conductor at least partially overlap each other in a plan view of the base material.

[0045] According to the first embodiment described above, with the RFID tag 10 including the coil conductor 16 and the RFIC chip 14 arranged in the opening 16a of the coil conductor 16, it is possible to prevent the communication distance from decreasing while the coil conductor 16 and the RFIC chip 14 are electrically connected. Second embodiment

[0046] Fig. 10 is a perspective view of an RFID tag according to a second embodiment of the present disclosure. Fig. 11 is a plan view of the RFID tag according to the second embodiment. Fig. 12 is an exploded perspective view of the RFID tag according to the second embodiment.

[0047] As in Fig. 10 to Fig. 12, the RFID tag 510 according to the second embodiment includes a base material 512, an RFIC chip 514, and a coil conductor 516. The coil conductor 516 includes a first spiral conductor 522 provided on a first surface 512a of the base material 512, a second spiral conductor 524 provided on a second surface 512b of the base material 512, and an interlayer connection conductor 526 electrically connecting an outer end of the first spiral conductor 522 and an outer end of the second spiral conductor 524.

[0048] A first connection conductor 528, which electrically connects an inner end of the first spiral conductor 522 and a first terminal 514a of the RFIC chip 514, is provided on the first surface 512a of the base material 512. The first connection conductor 528 is electrically connected to the first terminal 514a of the RFIC chip 514 via a first pad conductor 518.

[0049] A second connection conductor 530, which electrically connects an inner end of the second spiral conductor 524 and a second terminal 514b of the RFIC chip 514, is provided on the second surface 512b of the base material 512. The second connection conductor 530 is electrically connected to the second terminal 514b of the RFIC chip 514 via an interlayer connection conductor 532 and a second land conductor 520.

[0050] The first connecting conductor 528 and the second connecting conductor 530 overlap each other on the base material 512 in a plan view (when viewed in the Z-axis direction). In the case of the second embodiment, the first connecting conductor 528 and the second connecting conductor 530 overlap each other in many sections.

[0051] With the RFID tag 510 of the second embodiment, as with the RFID tag 10 of the first embodiment, it is also possible to prevent the communication distance from decreasing while the coil conductor 516 and the RFIC chip 514 are electrically connected to each other.

[0052] The number of turns of the coil conductor 516 in the RFID tag 510 according to the second embodiment is greater than the number of turns of the coil conductor 16 in the RFID tag 10 of the first embodiment. This is because the communication frequencies of the RFID tag 10 of the first embodiment and the RFID tag 510 of the second embodiment differ, and thus the required inductances of the coil conductors differ. In the case of the second embodiment, the first spiral conductor 522 in the coil conductor 516, unlike the second spiral conductor 524, has curved corner portions protruding toward a center to precisely adjust the inductance of the coil conductor 516 to a suitable value. Third embodiment

[0053] Fig. 13 is a perspective view of an RFID tag according to a third embodiment of the present disclosure. Fig. 14 is a plan view of the RFID tag according to the third embodiment. Fig. 15 is an exploded perspective view of the RFID tag according to the third embodiment.

[0054] As in Fig. 13 to Fig. 15, an RFID tag 610 according to the third embodiment includes a base material 612, an RFIC chip 614, and a coil conductor 616. The coil conductor 616 includes a first spiral conductor 622 provided on a first surface 612a of the base material 612, a second spiral conductor 624 provided on a second surface 612b of the base material 612, and an interlayer connection conductor 626 electrically connecting one end of the first spiral conductor 622 and one end of the second spiral conductor 624.

[0055] A first connecting conductor 628, which electrically connects another end of the first spiral conductor 622 and a first terminal 614a of the RFIC chip 614, is provided on the first surface 612a of the base material 612. The first connecting conductor 628 is electrically connected to the first terminal 614a of the RFIC chip 614 via a first pad conductor 618.

[0056] A second connection conductor 630, which electrically connects another end of the second spiral conductor 624 and a second terminal 614b of the RFIC chip 614, is provided on the second surface 612b of the base material 612. The second connection conductor 630 is electrically connected to the second terminal 614b of the RFIC chip 614 via an interlayer connection conductor 632 and a second pad conductor 620.

[0057] The first connection conductor 628 and the second connection conductor 630 overlap each other on the base material 612 in a plan view (when viewed in the Z-axis direction). Unlike the first connection conductor 28 and the second connection conductor 30 of the first embodiment, the first connection conductor 628 and the second connection conductor 630 further cross each other. Thus, a gap is formed between a portion of the first connection conductor 628 and a portion of the second connection conductor 630, extending between a crossover part and the RFIC chip 614. Due to this gap, magnetic fields generated by the respective portions of the first connection conductor 628 and the second connection conductor 630 cannot cancel each other.However, since magnetic fields generated in the crossover part cancel each other, the communication distance is longer than in the case where the first connection conductor and the second connection conductor do not overlap each other at all (for example, in the case of the first and second comparative examples described above).

[0058] With the RFID tag 610 of the third embodiment, as with the RFID tag 10 of the first embodiment, it is also possible to prevent the communication distance from decreasing while the coil conductor 616 and the RFIC chip 614 are electrically connected.

[0059] The present disclosure has been described above with reference to a plurality of embodiments, but the embodiments of the present disclosure are not limited thereto.

[0060] In the case of the first embodiment, as for example in Fig.As shown in FIG. 3, the coil conductor 16 is composed of the first spiral conductor 22 provided on the first surface 12a of the base material 12 and the second spiral conductor 24 provided on the second surface 12b of the base material 12. However, embodiments of the present disclosure are not limited thereto. For example, the coil conductor may be composed of a spiral conductor formed on only one of the first and second surfaces of the base material. Specifically, various aspects of the present disclosure are as follows.

[0061] A first aspect is an RFID tag comprising: a base material having a first surface and a second surface opposite to the first surface; a coil conductor comprising a first spiral conductor provided on the first surface of the base material, a second spiral conductor provided on the second surface of the base material, and an interlayer connection conductor extending through the base material and electrically connecting one end of the first spiral conductor and one end of the second spiral conductor; an RFIC chip provided on the base material such that the RFIC chip is positioned in an opening of the coil conductor in a plan view of the base material, and comprising a first terminal and a second terminal;a first connecting conductor provided on the first surface of the base material and electrically connecting another end of the first spiral conductor and the first terminal of the RFIC chip; and a second connecting conductor provided on the second surface of the base material and electrically connecting another end of the second spiral conductor and the second terminal of the RFIC chip. The first connecting conductor and the second connecting conductor at least partially overlap in a plan view of the base material.

[0062] A second aspect is the RFID tag according to the first aspect, wherein overlapping portions of the first connecting conductor and the second connecting conductor extend in an identical direction in the plan view of the base material.

[0063] A third aspect is the RFID tag according to the first aspect, wherein the first connecting conductor and the second connecting conductor cross each other in the plan view of the base material.

[0064] A fourth aspect is the RFID tag according to any one of the first to third aspects, further comprising: a first pad conductor provided on the first surface of the base material and electrically connected to the first terminal of the RFIC chip while pointing thereto; and a second pad conductor provided on the first surface of the base material and electrically connected to the second terminal of the RFIC chip while pointing thereto, wherein the first connection conductor is electrically connected to the first pad conductor, and the second connection conductor is electrically connected to the second pad conductor.

[0065] A fifth aspect is the RFID tag according to the fourth aspect, further comprising a land holding conductor provided on the second surface of the base material such that the land holding conductor faces both the first land conductor and the second land conductor in the plan view of the base material, and holding the first land conductor and the second land conductor

[0066] A sixth aspect is the RFID tag according to the fifth aspect, wherein the pad holding conductor is a part of the second connecting conductor.

[0067] In the RFID tags according to the embodiment of the present disclosure, the first connection conductor and the second connection conductor overlap each other at least partially in a plan view of the base material, so that the magnetic field generated by the first connection conductor and the magnetic field generated by the second connection conductor cancel each other. However, the magnetic fields may cancel each other without the first connection conductor and the second connection conductor overlapping each other. Specifically, when the first connection conductor and the second connection conductor include at least portions extending in an identical direction parallel to each other with a predetermined distance, and the predetermined distance is small, the magnetic field generated by the first connection conductor and the magnetic field generated by the second connection conductor substantially cancel each other.The predetermined distance is, for example, a distance smaller than the widths of the first and second connecting conductors. In the first embodiment, when the first connecting conductor and the second connecting conductor overlap each other in a plan view of the base material, a capacitance is formed between the first and second connecting conductors. This capacitance can reduce the inductance of the coil conductor, thus reducing the number of turns of the coil conductor. This allows the RFID tag to be downsized, which is advantageous. INDUSTRIAL APPLICABILITY

[0068] The present disclosure may be applied to an RFID tag having a coil conductor and an RFIC chip disposed in an opening of the coil conductor. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] JP-A-2008-244740

[0003]

Claims

[1] An RFID tag that has the following features: a base material comprising a first surface and a second surface opposite the first surface; a coil conductor comprising a first spiral conductor provided on the first surface of the base material, a second spiral conductor provided on the second surface of the base material, and an interlayer connection conductor extending through the base material and electrically connecting one end of the first spiral conductor and one end of the second spiral conductor; an RFIC chip provided on the base material such that the RFIC chip is positioned in an opening of the coil conductor in a plan view of the base material, and comprising a first terminal and a second terminal; a first connecting conductor provided on the first surface of the base material and electrically connecting another end of the first spiral conductor and the first terminal of the RFIC chip; and a second connecting conductor provided on the second surface of the base material and electrically connecting another end of the second spiral conductor and the second terminal of the RFIC chip, wherein the first connecting conductor and the second connecting conductor at least partially overlap in a plan view of the base material. [2] The RFID tag according to claim 1, wherein overlapping portions of the first connecting conductor and the second connecting conductor extend in an identical direction in the plan view of the base material. [3] The RFID tag according to claim 1, wherein the first connection conductor and the second connection conductor cross each other in the plan view of the base material. [4] The RFID tag according to any one of claims 1 to 3, further comprising: a first pad conductor disposed on the first surface of the base material and electrically connected to the first terminal of the RFIC chip while pointing thereto; and a second pad conductor provided on the first surface of the base material and electrically connected to the second terminal of the RFIC chip while pointing thereto, wherein the first connecting conductor is electrically connected to the first pad conductor, and the second connecting conductor is electrically connected to the second connection surface conductor. [5] The RFID tag according to claim 4, further comprising a land holding conductor provided on the second surface of the base material such that the land holding conductor faces both the first land conductor and the second land conductor in the plan view of the base material, and holds the first land conductor and the second land conductor. [6] The RFID tag according to claim 5, wherein the pad holding conductor is a part of the second connection conductor.

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