RFID tags

Abstract

This RFID tag comprises: a substrate that includes a first surface and a second surface; a coil conductor that includes first and second spiral conductors respectively provided on the first surface and second surface of the substrate; an RFIC chip that is provided on the substrate so as to be positioned in an opening in the coil conductor in a plan view of the substrate; and first and second connection conductors that are respectively provided on the first surface and second surface of the substrate and electrically connect the first and second spiral conductors to the RFIC chip. The first connection conductor and the second connection conductor at least partially overlap each other in a plan view of the substrate.

Description

[Technical Field]

[0001] The present disclosure relates to RFID tags. [Background technology]

[0002] For example, as described in Patent Document 1, there is known an RFID tag that includes an RFIC chip and a coil conductor that is electrically connected to the RFIC chip and used as an antenna. The RFIC chip is disposed within an opening in the coil conductor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-244740 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the RFID tag described in Patent Document 1, a first connecting conductor electrically connecting one end of the coil conductor to the RFIC chip and a second connecting conductor electrically connecting the other end of the coil conductor to the RFIC chip extend in opposite directions from the RFIC chip. Therefore, the magnetic flux generated by current flowing through the first connecting conductor, RFIC chip, and second connecting conductor cancels out a portion of the magnetic flux generated by current flowing through the coil conductor and passing through its opening. As a result, the communication distance of the RFID tag is shortened.

[0005] Therefore, an object of the present disclosure is to electrically connect a coil conductor and an RFIC chip placed within an opening of the coil conductor in an RFID tag while suppressing a decrease in communication distance. [Means for solving the problem]

[0006] In order to solve the above technical problem, according to one aspect of the present disclosure, a substrate having a first surface and a second surface opposite the first surface; a coil conductor including a first spiral conductor provided on the first surface of the substrate, a second spiral conductor provided on the second surface of the substrate, and an interlayer connection conductor that penetrates the substrate and electrically connects one end of the first spiral conductor and one end of the second spiral conductor; an RFIC chip provided on the substrate so as to be positioned within the opening of the coil conductor in a plan view of the substrate, the RFIC chip having first and second terminals; a first connecting conductor provided on a first surface of the substrate, electrically connecting the other end of the first spiral conductor and the first terminal of the RFIC chip; a second connecting conductor provided on a second surface of the substrate and electrically connecting the other end of the second spiral conductor and the second terminal of the RFIC chip; The RFID tag is provided such that, in a plan view of the base material, the first connecting conductor and the second connecting conductor at least partially overlap each other. [Effects of the Invention]

[0007] According to the present disclosure, in an RFID tag having a coil conductor and an RFIC chip placed within an opening of the coil conductor, the coil conductor and the RFIC chip can be electrically connected while suppressing a decrease in communication distance. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view of an RFID tag according to a first embodiment of the present disclosure; [Figure 2] 1 is a top view of an RFID tag according to a first embodiment; [Figure 3] FIG. 1 is an exploded perspective view of an RFID tag according to a first embodiment; [Figure 4] Schematic diagram of RFID tag in Comparative Example 1 [Figure 5] Schematic diagram of an RFID tag according to Example 1 [Figure 6] Top view of RFID tag of Comparative Example 2 [Figure 7] Exploded perspective view of an RFID tag of Comparative Example 2 [Figure 8] Top view of the RFID tag of Example 2 [Figure 9] FIG. 10 is an exploded perspective view of an RFID tag according to a second embodiment of the present invention; [Figure 10] FIG. 10 is a perspective view of an RFID tag according to a second embodiment of the present disclosure. [Figure 11] 10 is a top view of an RFID tag according to a second embodiment. [Figure 12] FIG. 10 is an exploded perspective view of an RFID tag according to a second embodiment. [Figure 13] FIG. 10 is a perspective view of an RFID tag according to a third embodiment of the present disclosure. [Figure 14] 10 is a top view of an RFID tag according to a third embodiment. [Figure 15] 10 is an exploded perspective view of an RFID tag according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0010] (Embodiment 1) Fig. 1 is a perspective view of an RFID tag according to a first embodiment of the present disclosure. Fig. 2 is a top 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. Note that the XYZ Cartesian coordinate system in the figures is intended to facilitate understanding of the present disclosure and does not limit the present disclosure. The X-axis direction indicates the width direction of the RFID tag, the Y-axis direction indicates the depth direction, and the Z-axis direction indicates the thickness direction.

[0011] As shown in Figures 1 to 3, an RFID (Radio Frequency IDentification) tag 10 according to the first embodiment has a substrate 12, an RFIC (Radio Frequency integrated circuit) chip 14 provided on the substrate 12, and a coil conductor 16 electrically connected to the RFIC chip 14.

[0012] The substrate 12 is a sheet-like member made of an insulating material, and has a first surface 12a and a second surface 12b opposite to the first surface 12a.

[0013] 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 that are electrically connected to the coil conductor 16.

[0014] In the first embodiment, the RFIC chip 14 is provided on the first surface 12a of the substrate 12. Specifically, first, a first land conductor 18 electrically connected to one end of the coil conductor 16 and a second land conductor 20 electrically connected to the other end of the coil conductor 16 are provided on the first surface 12a of the substrate 12. These first and second land conductors 18, 20 are, for example, conductor patterns.

[0015] The first terminal 14a of the RFIC chip 14 faces the first land conductor 18 and is fixed and electrically connected to the first land conductor 18 via, for example, a solder material. The second terminal 14b of the RFIC chip 14 faces the second land conductor 20 and is fixed and electrically connected to the second land conductor 20 via, for example, a solder material.

[0016] The coil conductor 16 functions as an antenna when the RFIC chip 14 performs wireless communication with an external device.

[0017] In the first embodiment, the coil conductor 16 includes a first spiral conductor 22 provided on the first surface 12a of the substrate 12 and a second spiral conductor 24 provided on the second surface 12b of the substrate 12. In a plan view of the substrate 12 (viewed in the Z-axis direction), the first spiral conductor 22 and the second spiral conductor 24 partially overlap each other. These first and second spiral conductors 22, 24 are, for example, conductor patterns.

[0018] In addition, in this embodiment 1, the coil conductor 16 includes an interlayer connection conductor portion 26, such as a through-hole conductor, that penetrates the substrate 12 in the thickness direction (Z-axis direction) and electrically connects one end 22a of the first spiral conductor 22 and one end 24a of the second spiral conductor 24.

[0019] 2, in a plan view (viewed in the Z-axis direction) of the substrate 12, the RFIC chip 14, the first land conductor 18, and the second land conductor 20 are arranged in the opening 16a of the coil conductor 16. In particular, the RFIC chip 14 is arranged in the center of the opening 16a.

[0020] A first connecting conductor 28 is provided on the first surface 12a of the substrate 12 to electrically connect the other end 22b of the first spiral conductor 22 of the coil conductor 16 to the first land conductor 18. The first connecting conductor 28 is, for example, a conductor pattern.

[0021] Furthermore, a second connecting conductor 30 is provided on the second surface 12b of the substrate 12 to electrically connect the other end 24b of the second spiral conductor 24 of the coil conductor 16 to the second land conductor 20. The second connecting conductor 30 is, for example, a conductor pattern.

[0022] The RFIC chip 14 and the coil conductor 16 are electrically connected by the first and second connection conductors 28, 30.

[0023] 2, the first connecting conductor 28 and the second connecting conductor 30 are provided on the first and second surfaces 12a, 12b of the base material 12, respectively, so as to at least partially overlap each other in a plan view of the base material 12 (as viewed in the Z-axis direction). More preferably, the first and second connecting conductors 28, 30 are provided on the base material 12 so as to overlap each other in as large a portion as possible. In the case of the first embodiment, the overlapping portions 28a, 30a of the first connecting conductor 28 and the second connecting conductor 30 extend linearly in the same direction. The reason why the first connecting conductor 28 and the second connecting conductor 30 partially overlap each other will be described later.

[0024] In the present embodiment, a land support conductor 34 that supports the first land conductor 18 and the second land conductor 20 is provided on the second surface 12b of the substrate 12. In the present embodiment, the land support conductor 34 is a part of the second connecting conductor 30.

[0025] The land support conductor 34 overlaps both the first land conductor 18 and the second land conductor 20 in a plan view (viewed in the Z-axis direction) of the substrate 12. In other words, the first land conductor 18 and the second land conductor 20 are located within the outline of the land support conductor 34 in a plan view of the substrate 12.

[0026] Such land support conductor 34 prevents the electrical connection between the first and second land conductors 18, 20 and the RFIC chip 14 from being cut off. This is because the second spiral conductor 24 exists on the front surface 12b side of the substrate 12, and the first and second land conductors 18, 20 would be floating in the air due to the conductor thickness (e.g., 20 μm) of this spiral conductor 24, but the presence of the land support conductor 34 keeps the first and second land conductors 18, 20 at the same height and prevents them from floating in the air. Therefore, in the case of solder connection, the solder is applied without bending the substrate 12 due to the pressure conditions of the solder squeegee, so poor connection between the RFIC chip 14 and the first and second land conductors 18, 20 does not occur.

[0027] Furthermore, for example, when the RFID tag 10 is attached to the surface of an object via the second surface 12b of the substrate 12, the distance from the first land conductor 18 to the object is the same as the distance from the second land conductor 20 to the object due to the presence of the land support conductor 34. Therefore, the RFID tag 10 can be attached to the object without tilting the RFIC chip 14.

[0028] On the other hand, when the land support conductor 34 is not present, the second spiral conductor 24 is present on the front surface 12b of the substrate 12, but due to the conductor thickness of this spiral conductor 24, the first and second land conductors 18, 20 are connected to the RFIC chip 14 in a floating state. For this reason, the height of the first and second land conductors 18, 20 is unstable, and in the case of solder connection, the solder is applied as the substrate 12 bends depending on the pressure conditions of the solder squeegee, making the amount of solder unstable and causing connection failures between the RFIC chip 14 and the first and second land conductors 18, 20. Similar connection failures can occur even when connecting ICs while applying a load, such as in ACP connection or ultrasonic welding.

[0029] Furthermore, when the RFID tag 10 is attached to the surface of an object via the second surface 12b of the substrate 12, if there is no conductor on the second surface 12b of the substrate 12 facing the first land conductor 18 and the second land conductor 20 faces the second connecting conductor 30, the RFIC chip 14 will tilt when the RFID tag 10 is attached to the surface of the object. This is because, due to the absence of the land support conductor 34, the distance from the first land conductor 18 to the object is shorter than the distance from the second land conductor 20 to the object. If the RFIC chip 14 tilts, for example, the electrical connection between the second terminal 14b and the second land conductor 20 may be broken.

[0030] So far, we have explained the configuration of the RFID tag 10 according to the present embodiment 1. From here, we will explain why the first connecting conductor 28 and the second connecting conductor 30 at least partially overlap each other in a plan view of the base material 12 (viewed in the Z-axis direction) as shown in Fig. 2.

[0031] Fig. 4 is a schematic diagram of an RFID tag of Comparative Example 1. Fig. 5 is a schematic diagram of an RFID tag of Example 1. The RFID tag shown in Fig. 5 corresponds to a simplified version of the RFID tag 10 according to the first embodiment shown in Figs. 1 to 3.

[0032] 4, the RFID tag 110 of Comparative Example 1 has a coil conductor 116 and an RFIC chip 114 disposed in an opening 116a of the coil conductor 116. The RFID tag 110 also has a first connecting conductor 128 that electrically connects one end of the coil conductor 116 to the RFIC chip 114, and a second connecting conductor 130 that electrically connects the other end of the coil conductor 116 to the RFIC chip 114. In the RFID tag 110 of Comparative Example 1, the first and second connecting conductors 128 and 130 extend in opposite directions from the RFIC chip 114 and do not overlap in a plan view.

[0033] 4, in the RFID tag 110 of the comparative example, a magnetic flux f1 is generated when a current i1 flows through the coil conductor 116. A magnetic flux f2 is generated when a current i2 flows through the first connecting conductor 128, the RFIC chip 114, and the second connecting conductor 130. The current i1 and the current i2 are the same current.

[0034] 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 cancels out part of the magnetic flux f1 passing through the opening 116a of the coil conductor 116. As a result, the communication distance of the RFID tag 110 that communicates wirelessly using the coil conductor 116 is shortened.

[0035] On the other hand, in the RFID tag 210 of Example 1 shown in Figure 5, the first connecting conductor 228 and the second connecting conductor 230 extend linearly in the same direction from the RFIC chip 214 and partially overlap each other (note that in Figure 5, the first connecting conductor 228 and the second connecting conductor 230 are shown in a non-overlapping state because they would be indistinguishable if they overlapped).

[0036] As shown in FIG. 5 , in the RFID tag 210 of the first embodiment, a magnetic flux f1 is generated by a current i1 flowing through the coil conductor 216. A magnetic flux is also generated by a current i2 flowing through the first connecting conductor 228, the RFIC chip 214, and the second connecting conductor 230. However, because the direction of the current i2 flowing through the first connecting conductor 228 and the direction of the current i2 flowing through the second connecting conductor 230 are opposite to each other, the magnetic flux generated in the first connecting conductor 228 and the magnetic flux generated in the second connecting conductor 230 cancel each other out. As a result, the magnetic flux f1 passing through the opening 216a of the coil conductor 216 is not substantially canceled out by the magnetic flux generated in the first and second connecting conductors 228 and 230. As a result, the communication distance of the RFID tag 210 of the first embodiment is longer than that of the RFID tag 110 of the first comparative example.

[0037] The inventors have verified this effect through simulations.

[0038] Fig. 6 is a top view of the model of the RFID tag of Comparative Example 2 used in the simulation. Fig. 7 is an exploded perspective view of the model of the RFID tag of Comparative Example 2. Fig. 8 is a top view of the model of the RFID tag of Example 2 used in the simulation. And Fig. 9 is an exploded perspective view of the model of the RFID tag of Example 2.

[0039] 6 and 7, in the RFID tag 310 of Comparative Example 2, the coil conductor 316 includes a first spiral conductor 322 provided on the first surface 312a of the substrate 312 and a second spiral conductor 324 provided on the second surface 312b. The coil conductor 316 also includes an interlayer connection conductor 326 that electrically connects the outer end of the first spiral conductor 322 to the outer end of the second spiral conductor 324. The RFIC chip 314 is disposed at the center of the opening 316a of the coil conductor 316 in a plan view of the substrate 312 (as viewed in the Z-axis direction). A first terminal 314a of the RFIC chip 314 is electrically connected to the inner end of the first spiral conductor 322 via a first connection conductor 328. The second terminal 314 b of the RFIC chip 314 is electrically connected to the inner end of the second spiral conductor 324 via a second connecting conductor 330 and an interlayer connecting conductor 332 .

[0040] Furthermore, as shown in FIG. 6, in the RFID tag 310 of Comparative Example 2, the first connecting conductor 328 and the second connecting conductor 330 do not overlap when the substrate 312 is viewed from above (as viewed in the Z-axis direction).

[0041] 8 and 9, in the RFID tag 410 of Example 2, the coil conductor 416 includes a first spiral conductor 422 provided on the first surface 412a of the substrate 412 and a second spiral conductor 424 provided on the second surface 412b. The coil conductor 416 also includes an interlayer connection conductor 426 that electrically connects the outer end of the first spiral conductor 422 to the outer end of the second spiral conductor 424. The RFIC chip 414 is disposed at the center of the opening 416a of the coil conductor 416 in a plan view of the substrate 412 (as viewed in the Z-axis direction). A first terminal 414a of the RFIC chip 414 is electrically connected to the inner end of the first spiral conductor 422 via a first connection conductor 428. The second terminal 414 b of the RFIC chip 414 is electrically connected to the inner end of the second spiral conductor 424 via a second connecting conductor 430 and an interlayer connecting conductor 432 .

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

[0043] The substrate 312 and RFIC chip 314 of Comparative Example 2 are the same as the substrate 412 and RFIC chip 414 of Example 2. The material of the conductors such as coil conductor 316 of Comparative Example 2 is the same as the material of the conductors such as coil conductor 416 of Example 2. Under these conditions, the inventors simulated the communication distances of the RFID tag 310 of Comparative Example 2 and the RFID tag 410 of Example 2.

[0044] As a result of the simulation, the communication distance of the RFID tag 310 of Comparative Example 2 was 10.5 mm, and the communication distance of the RFID tag 410 of Example 2 was 12.5 mm. This simulation result shows that the communication distance of the RFID tag is improved if the first connecting conductor and the second connecting conductor at least partially overlap in a plan view of the substrate.

[0045] According to the above-described first embodiment, in an RFID tag 10 having a coil conductor 16 and an RFIC chip 14 arranged in the opening 16a of the coil conductor 16, the coil conductor 16 and the RFIC chip 14 can be electrically connected while suppressing a decrease in communication distance.

[0046] (Embodiment 2) Fig. 10 is a perspective view of an RFID tag according to embodiment 2 of the present disclosure, Fig. 11 is a top view of the RFID tag according to embodiment 2, and Fig. 12 is an exploded perspective view of the RFID tag according to embodiment 2.

[0047] 10 to 12, an RFID tag 510 according to the second embodiment has a substrate 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 substrate 512, a second spiral conductor 524 provided on a second surface 512b of the substrate 512, and an interlayer connection conductor 526 that electrically connects the outer circumferential ends of the first spiral conductor 522 and the second spiral conductor 524.

[0048] Furthermore, a first connecting conductor 528 is provided on the first surface 512a of the substrate 512, electrically connecting the inner end of the first spiral conductor 522 and the first terminal 514a of the RFIC chip 514. The first connecting conductor 528 is electrically connected to the first terminal 514a of the RFIC chip 514 via the first land conductor 518.

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

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

[0051] Like the RFID tag 10 of the first embodiment, the RFID tag 510 of the second embodiment can also electrically connect the coil conductor 516 and the RFIC chip 514 while suppressing a decrease in the communication distance.

[0052] The number of turns in the coil conductor 516 of the RFID tag 510 of the second embodiment is greater than the number of turns in the coil conductor 16 of the RFID tag 10 of the first embodiment. This is because the RFID tag 10 of the first embodiment and the RFID tag 510 of the second embodiment differ in communication frequency, and therefore the required inductance of the coil conductor differs. In addition, in the case of the second embodiment, the first spiral conductor 522 of the coil conductor 516 has corners that are curved convexly toward the center, unlike the second spiral conductor 524, in order to finely adjust the inductance of the coil conductor 516 to an appropriate value.

[0053] (Embodiment 3) Fig. 13 is a perspective view of an RFID tag according to embodiment 3 of the present disclosure, Fig. 14 is a top view of the RFID tag according to embodiment 3, and Fig. 15 is an exploded perspective view of the RFID tag according to embodiment 3.

[0054] 13 to 15, an RFID tag 610 according to the third embodiment has a substrate 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 substrate 612, a second spiral conductor 624 provided on a second surface 612b of the substrate 612, and an interlayer connection conductor 626 that electrically connects one end of the first spiral conductor 622 and one end of the second spiral conductor 624.

[0055] Furthermore, a first connecting conductor 628 is provided on the first surface 612a of the substrate 612, electrically connecting the other end of the first spiral conductor 622 to a first terminal 614a of the RFIC chip 614. The first connecting conductor 628 is electrically connected to the first terminal 614a of the RFIC chip 614 via a first land conductor 618.

[0056] Furthermore, a second connection conductor 630 is provided on the second surface 612b of the substrate 612, electrically connecting the other end of the second spiral conductor 624 to a second terminal 614b of the RFIC chip 614. The second connection conductor 630 is electrically connected to the second terminal 614b of the RFIC chip 614 via the interlayer connection conductor 632 and the second land conductor 620.

[0057] The first connecting conductor 628 and the second connecting conductor 630 overlap each other in a plan view (viewed in the Z-axis direction) on the substrate 612. Furthermore, unlike the first connecting conductor 28 and the second connecting conductor 30 in the first embodiment described above, the first connecting conductor 628 and the second connecting conductor 630 intersect each other. Therefore, a gap is generated between the portion of the first connecting conductor 628 and the portion of the second connecting conductor 630 that extend between the intersection and the RFIC chip 614. Due to this gap, the magnetic fields generated in the portion of the first connecting conductor 628 and the portion of the second connecting conductor 630 cannot cancel each other out. However, because the magnetic fields generated at the intersection can cancel each other out, the communication distance is longer than when the first connecting conductor and the second connecting conductor do not overlap at all (for example, in the cases of the above-described comparative examples 1 and 2).

[0058] Like the RFID tag 10 of the first embodiment, the RFID tag 610 of the third embodiment can also electrically connect the coil conductor 616 and the RFIC chip 614 while suppressing a decrease in the communication distance.

[0059] Although the present disclosure has been described above with reference to a number of embodiments, the present disclosure is not limited to these embodiments.

[0060] For example, in the case of the above-described first embodiment, as shown in Fig. 3, the coil conductor 16 is composed of a first spiral conductor 22 provided on the first surface 12a of the substrate 12 and a second spiral conductor 24 provided on the second surface 12b of the substrate 12. However, the embodiments of the present disclosure are not limited to this. For example, the coil conductor may be composed of a spiral conductor formed on only one of the first and second surfaces of the substrate.

[0061] That is, various aspects of the present disclosure are as follows.

[0062] The first aspect is a substrate having a first surface and a second surface opposite the first surface; a coil conductor including a first spiral conductor provided on the first surface of the substrate, a second spiral conductor provided on the second surface of the substrate, and an interlayer connection conductor that penetrates the substrate and electrically connects one end of the first spiral conductor and one end of the second spiral conductor; an RFIC chip provided on the substrate so as to be positioned within the opening of the coil conductor in a plan view of the substrate, the RFIC chip having first and second terminals; a first connecting conductor provided on a first surface of the substrate, electrically connecting the other end of the first spiral conductor and the first terminal of the RFIC chip; a second connecting conductor provided on a second surface of the substrate and electrically connecting the other end of the second spiral conductor and the second terminal of the RFIC chip; In the RFID tag, the first connecting conductor and the second connecting conductor at least partially overlap each other when the substrate is viewed from above.

[0063] The second aspect is In the RFID tag of the first aspect, in a plan view of the base material, the overlapping portions of the first connecting conductor and the second connecting conductor extend in the same direction.

[0064] The third aspect is In the RFID tag of the first aspect, the first connecting conductor and the second connecting conductor cross each other in a plan view of the base material.

[0065] The fourth aspect is a first land conductor provided on the first surface of the base material, facing and electrically connected to the first terminal of the RFIC chip; a second land conductor provided on the first surface of the substrate, facing and electrically connected to the second terminal of the RFIC chip; the first connecting conductor is electrically connected to the first land conductor; In the RFID tag according to any one of the first to third aspects, the second connection conductor is electrically connected to the second land conductor.

[0066] The fifth aspect is A fourth aspect of the RFID tag further includes a land support conductor that is provided on the second surface of the substrate so as to face both the first land conductor and the second land conductor in a planar view of the substrate, and that supports the first and second land conductors.

[0067] The sixth aspect is In the RFID tag of a fifth aspect, the land support conductor is a part of the second connecting conductor.

[0068] In the RFID tag according to the above-described embodiment of the present disclosure, the first connecting conductor and the second connecting conductor at least partially overlap each other in a planar view of the substrate, thereby canceling out the magnetic fields generated by the first connecting conductor and the second connecting conductor. However, it is possible to cancel out the magnetic fields of the first connecting conductor and the second connecting conductor without overlapping each other. That is, if the first connecting conductor and the second connecting conductor each include at least a portion extending parallel to each other in the same direction with a predetermined distance therebetween, and if this predetermined distance is small, the magnetic fields generated by the first connecting conductor and the second connecting conductor will essentially cancel out each other. The predetermined distance is, for example, a distance smaller than the width of the first and second connecting conductors. However, as in the above-described first embodiment, when the first connecting conductor and the second connecting conductor overlap each other in a planar view of the substrate, a capacitance is formed between them. This capacitance can reduce the inductance of the coil conductor, i.e., the number of turns of the coil conductor, which has the advantage of allowing the RFID tag to be made smaller. [Industrial Applicability]

[0069] The present disclosure is applicable to RFID tags having a coil conductor and an RFIC chip disposed within an opening in the coil conductor.

Claims

1. a substrate having a first surface and a second surface opposite the first surface; a coil conductor including a first spiral conductor provided on the first surface of the substrate, a second spiral conductor provided on the second surface of the substrate, and an interlayer connection conductor that penetrates the substrate and electrically connects one end of the first spiral conductor and one end of the second spiral conductor; an RFIC chip provided on the substrate so as to be positioned within the opening of the coil conductor in a plan view of the substrate, the RFIC chip including first and second terminals; a first land conductor provided on the substrate so as to overlap the first terminal of the RFIC chip in a plan view of the substrate and electrically connected to the first terminal; a second land conductor provided on the substrate so as to overlap the second terminal of the RFIC chip in a plan view of the substrate and electrically connected to the second terminal; a first connecting conductor provided on a first surface of the substrate and electrically connecting the other end of the first spiral conductor and the first land conductor; a second connecting conductor provided on a second surface of the substrate and electrically connecting the other end of the second spiral conductor and the second land conductor; a land support conductor that is provided on the second surface of the substrate so as to face at least a portion of the first land conductor, the second land conductor, the first terminal, and the second terminal in a plan view of the substrate, and that supports the first and second land conductors; An RFID tag, wherein the first connecting conductor and the second connecting conductor at least partially overlap each other when viewed in a plan view of the substrate.

2. The RFID tag according to claim 1 , wherein, in a plan view of the base material, the overlapping portions of the first connecting conductor and the second connecting conductor extend in the same direction.

3. The RFID tag according to claim 1 , wherein the first connecting conductor and the second connecting conductor intersect with each other in a plan view of the base material.

4. The RFID tag of claim 1 , wherein the land support conductor is a part of the second connecting conductor.

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