RFID tag

Abstract

Provided is an RFID tag including a multilayer substrate, a coil antenna, and an RFIC chip connected to the coil antenna and provided in a first layer of the multilayer substrate. The coil antenna includes: a first spiral conductor pattern provided in the first layer and connected to the RFIC chip; a second spiral conductor pattern provided in a second layer of the multilayer substrate; and a non-spiral intermediate conductor pattern which is provided in a third layer of the multilayer substrate between the first and second layers and connects the first spiral conductor pattern and the second spiral conductor pattern to each other. The first spiral conductor pattern is closer to the intermediate conductor pattern than the second spiral conductor pattern in the layering direction of the multilayer substrate.

Description

RFID tag

[0001] The present disclosure relates to RFID tags.

[0002] Patent Document 1 discloses a wireless IC tag (RFID tag) equipped with a coil antenna.

[0003] Patent No. 5630166

[0004] Incidentally, in the case of an RFID tag equipped with a coil antenna such as the RFID tag described in Patent Document 1, changing the antenna length (electrical length) to adjust the resonant frequency (i.e., communication frequency) may shorten the communication distance.

[0005] Therefore, an object of the present disclosure is to realize a structure in an RFID tag equipped with a coil antenna that allows the resonance frequency of the coil antenna to be adjusted without affecting the communication distance of the coil antenna.

[0006] In order to solve the above technical problems, according to one aspect of the present disclosure, there is provided an RFID tag comprising: a multilayer substrate; a coil antenna provided on the multilayer substrate; and an RFIC chip connected to the coil antenna and provided on a first layer of the multilayer substrate, wherein the coil antenna includes: a first spiral conductor pattern provided on the first layer and connected to the RFIC chip; a second spiral conductor pattern provided on a second layer of the multilayer substrate; and a non-spiral intermediate conductor pattern provided on a third layer of the multilayer substrate between the first layer and the second layer, connecting the first spiral conductor pattern and the second spiral conductor pattern, wherein the first spiral conductor pattern is closer to the intermediate conductor pattern in the stacking direction of the multilayer substrate than the second spiral conductor pattern.

[0007] According to the present disclosure, in an RFID tag equipped with a coil antenna, it is possible to realize a structure that allows the resonant frequency of the coil antenna to be adjusted without affecting the communication distance of the coil antenna.

[0008] 6A and 6B. FIG. 6C is a schematic diagram of an RFID tag according to an embodiment of the present disclosure. FIG. 6A is an exploded perspective view of an RFID tag. FIG. 6C is a perspective view showing electrical connections in an RFID tag. FIG. 6B is a schematic diagram of an RFID tag according to an embodiment of the present disclosure.

[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 an embodiment of the present disclosure. Fig. 2 is an exploded perspective view of the RFID tag. Fig. 3 is a perspective view showing electrical connections in the RFID tag. Note that the X-Y-Z 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 FIGS. 1 to 3, an RFID (Radio Frequency Identification) tag 10 according to the first embodiment includes a multilayer substrate 12, a coil antenna 14 provided on the multilayer substrate 12, and an RFIC (Radio Frequency integrated circuit) chip 16 connected to the coil antenna 14.

[0012] The multilayer substrate 12 is a stack of substrates made of an insulating material such as resin. In this embodiment, the multilayer substrate 12 includes a first substrate 20, a second substrate 22, and a third substrate 24. The multilayer substrate 12 is formed by bonding these substrates 20, 22, and 24 together via adhesive layers (not shown). The second substrate 22 is disposed between the first substrate 20 and the third substrate 24.

[0013] Coil antenna 14 is an antenna that extends helically and is provided on multilayer substrate 12. Specifically, coil antenna 14 is composed of conductor patterns provided on first substrate 20, second substrate 22, and third substrate 24, respectively.

[0014] In this embodiment, the coil antenna 14 includes a first spiral conductor pattern 30 provided on a first layer of the multilayer substrate 12, a second spiral conductor pattern 32 provided on a second layer of the multilayer substrate 12 different from the first layer, and an intermediate conductor pattern 34 provided on a third layer of the multilayer substrate 12 between the first layer and the second layer.

[0015] 2 and 3, the first spiral conductor pattern 30 is a conductor pattern that extends in a spiral shape and is provided on the first layer of the multilayer substrate 12, specifically, formed on one surface 20a of the first substrate 20. The first spiral conductor pattern 30 is made of a conductive material such as copper.

[0016] The first spiral conductor pattern 30 also includes a first electrode portion 30a connected to the first input / output terminal 16a of the RFIC chip 16 and a second electrode portion 30b connected to the second input / output terminal 16b. The first and second input / output terminals 16a, 16b are electrically connected to the first and second electrode portions 30a, 30b via, for example, solder. The first spiral conductor pattern 30 also includes a first land portion 30c and a second land portion 30d provided on both ends, respectively. The first land portion 30c is located on the inner side, and the second land portion 30d is located on the outer side.

[0017] The first spiral conductor pattern 30 extends spirally with one or more turns from the inner first land portion 30c to the outer second land portion 30d, so as to surround the first and second electrode portions 30a, 30b. Strictly speaking, the first and second electrode portions 30a, 30b are electrically connected via the RFIC chip 16, so that the first spiral conductor pattern 30 establishes a current path extending spirally with one or more turns.

[0018] 2, the first spiral conductor pattern 30 is covered with a resist layer 36. Also, in this embodiment, one surface 20a of the first substrate 20 is covered with a mold resin 38. The resist layer 36 and the mold resin 38 protect the RFIC chip 16 and the first spiral conductor pattern 30 provided on the one surface 20a of the first substrate 20.

[0019] The second spiral conductor pattern 32 is a spiral conductor pattern provided on the second layer of the multilayer substrate 12, specifically, formed on the other surface 24b of the third substrate 24. The second spiral conductor pattern 32 is made of a conductive material such as copper.

[0020] The second spiral conductor pattern 32 includes a first land 32a and a second land 32b, each located at one end. The first land 32a is located on the inside, and the second land 32b is located on the outside. The second spiral conductor pattern 32 extends in a spiral shape with one or more turns, from the first land 32a on the inside to the second land 32b on the outside.

[0021] In this embodiment, the second spiral conductor pattern 32 is covered and protected by a resist layer 40 as shown in FIG.

[0022] 2 and 3, the intermediate conductor pattern 34 is a conductor pattern provided on the third layer of the multilayer substrate 12, specifically formed on one surface 22a of the second substrate 22 opposite the other surface 20b of the first substrate 20. The intermediate conductor pattern 34 is made of a conductive material such as copper.

[0023] The intermediate conductor pattern 34 includes a first land 34a and a second land 34b provided on each end. The first land 34a is electrically connected to the first land 30c of the first spiral conductor pattern 30 via an interlayer connection conductor 42, such as a through-hole conductor, that penetrates the first substrate 20. The second land 34b is electrically connected to the first land 32a of the second spiral conductor pattern 32 via an interlayer connection conductor 44, a land 46, and an interlayer connection conductor 48. The interlayer connection conductor 44 is a conductor that penetrates the second substrate 22. The land 46 is a conductor pattern formed on the other surface 22b of the second substrate 22. The interlayer connection conductor 48 is a conductor that penetrates the third substrate 24.

[0024] Unlike the first and second spiral conductor patterns 30, 32, the intermediate conductor pattern 34 does not extend in a spiral shape with one or more turns. That is, the intermediate conductor pattern 34 is a non-spiral conductor pattern. In the present embodiment, the intermediate conductor pattern 34 extends from a first land 34a provided near one end of the second substrate 22 in the width direction (X-axis direction) to a second land 34b provided near the other end of the second substrate 22.

[0025] In this embodiment, as shown in FIG. 2, the intermediate conductor pattern 34 is protected by being covered by the first substrate 20 .

[0026] As shown in Figures 2 and 3, the second land portion 30d of the first spiral conductor pattern 30 and the second land portion 32b of the second spiral conductor pattern 32 are electrically connected via the interlayer connection conductor 50, the land 52, the interlayer connection conductor 54, the land 56, and the interlayer connection conductor 58. The interlayer connection conductor 50, like the interlayer connection conductor 42, is a conductor that penetrates the first substrate 20. The land 52, like the intermediate conductor pattern 34, is a conductor pattern provided on one surface 22a of the second substrate 22. The interlayer connection conductor 54, like the interlayer connection conductor 44, is a conductor that penetrates the second substrate 22. The land 56, like the land 46, is a conductor pattern provided on the other surface 22b of the second substrate 22. The interlayer connection conductor 58, like the interlayer connection conductor 48, is a conductor that penetrates the third substrate 24.

[0027] 4 is a top view of the first and second spiral conductor patterns, in which the second spiral conductor pattern 32 is indicated by dashed-dotted hatching.

[0028] 4, the first spiral conductor pattern 30 and the second spiral conductor pattern 32 at least partially overlap when viewed in the stacking direction (Z-axis direction) of the multilayer substrate 12. In this embodiment, the first spiral conductor pattern 30 and the second spiral conductor pattern 32 have substantially the same width.

[0029] Furthermore, in this embodiment, as shown in FIG. 2 , the first layer of the multilayer substrate 12 on which the first spiral conductor pattern 30 is provided is the outer surface on one side of the stacking direction (Z-axis direction) of the multilayer substrate 12 (one surface 20a of the first substrate 20 in this embodiment). The second layer on which the second spiral conductor pattern 32 is provided is the outer surface on the other side of the stacking direction of the multilayer substrate 12 (the other surface 24b of the third substrate 24 in this embodiment). That is, the first spiral conductor pattern 30 and the second spiral conductor pattern 32 are provided on the multilayer substrate 12 with as much space between them as possible in the stacking direction. This prevents strong electromagnetic field coupling between the first spiral conductor pattern 30 and the second spiral conductor pattern 32, allowing the electromagnetic field to spread over a wide area from the coil antenna 14. As a result, the communication distance of the coil antenna 14 is extended.

[0030] Furthermore, in this embodiment, the first spiral conductor pattern 30 and the second spiral conductor pattern 32 are substantially equal in electrical length and number of turns. In this embodiment, the first spiral conductor pattern 30 and the second spiral conductor pattern 32 extend spirally with approximately 1.75 turns. This allows the outer surface on one side of the multilayer substrate 12 in the stacking direction (Z-axis direction) (one surface 20a of the first substrate 20 on which the first spiral conductor pattern 30 is provided) and the outer surface on the other side (the other surface 24b of the third substrate 24 on which the first spiral conductor pattern 32 is provided) to thermally expand in the same manner. As a result, warping of the multilayer substrate 12 is suppressed.

[0031] The RFIC chip 16 is an electronic component configured to perform wireless communication with an external device (e.g., a reader / writer device) at a predetermined communication frequency using the coil antenna 14. To electrically connect to the coil antenna 14, the RFIC chip 16 includes first and second input / output terminals 16a and 16b.

[0032] In this RFID tag 10, when the coil antenna 14 receives a signal from a reader / writer device at a predetermined communication frequency, a current corresponding to the signal flows from the coil antenna 14 to the RFIC chip 16. This activates the RFIC chip 16, which supplies a current corresponding to a response signal to the received signal to the coil antenna 14. When a current flows through the coil antenna 14, the coil antenna 14 transmits a response signal to the reader / writer device.

[0033] The coil antenna 14 has a corresponding predetermined resonant frequency for transmitting and receiving signals at a predetermined communication frequency. To achieve the predetermined resonant frequency, the electrical length and the inter-conductor distance of the coil antenna 14 are adjusted.

[0034] Specifically, the lengths (electrical lengths) of the first spiral conductor pattern 30, the second spiral conductor pattern 32, and the intermediate conductor pattern 34 are adjusted so that the coil antenna 14 has a predetermined resonant frequency. In addition, the distance between the first spiral conductor pattern 30 and the intermediate conductor pattern 34 in the stacking direction (Z-axis direction) of the multilayer substrate 12 is adjusted.

[0035] 2, the intermediate conductor pattern 34 is provided to adjust the resonant frequency of the coil antenna 14 without reducing the communication distance of the coil antenna 14. This will be described below.

[0036] First, the intermediate conductor pattern 34 is disposed between the first spiral conductor pattern 30 and the second spiral conductor pattern 32. Furthermore, the intermediate conductor pattern 34 is disposed close to the first spiral conductor pattern 30 and far from the second spiral conductor pattern 32. In other words, the first spiral conductor pattern 30 is closer to the intermediate conductor pattern 34 than the second spiral conductor pattern 32.

[0037] 3, the distance D1 in the stacking direction (Z-axis direction) between the first spiral conductor pattern 30 and the intermediate conductor pattern 34 is smaller than the distance D2 in the product direction between the second spiral conductor pattern 32 and the intermediate conductor pattern 34. These distances D1 and D2 are achieved by the thickness t1 of the first substrate 20 being smaller than the sum of the thickness t2 of the second substrate 22 and the thickness t3 of the third substrate 24, as shown in FIG.

[0038] As a result, the capacitance formed between the first spiral conductor pattern 30 and the intermediate conductor pattern 34 contributes more to the resonant frequency of the coil antenna 14 than the capacitance formed between the second spiral conductor pattern 32 and the intermediate conductor pattern 34. In other words, the capacitance between the first spiral conductor pattern 30 and the intermediate conductor pattern 34 essentially determines the resonant frequency of the coil antenna 14.

[0039] 5 is a top view of the first spiral conductor pattern and the intermediate conductor pattern 34. In FIG. 5, the intermediate conductor pattern 34 is indicated by dashed hatching.

[0040] As shown in Figure 5, in this embodiment, the intermediate conductor pattern 34 at least partially overlaps the first spiral conductor pattern 30 when viewed in the stacking direction (Z-axis direction) of the multilayer substrate 12. The first spiral conductor pattern 30 and the intermediate conductor pattern 34, which are flat and parallel to each other, partially overlap in the stacking direction, forming a capacitance between them. The capacitance between them can be easily adjusted by adjusting the amount of overlap between them. As a result, the resonant frequency of the coil antenna 14 can be adjusted without substantially changing the electrical length of the coil antenna 14.

[0041] Fig. 6A is a top view of the first spiral conductor pattern and the intermediate conductor pattern in a state where the overlap amount is greater than in Fig. 5. Fig. 6B is a top view of the first spiral conductor pattern and the intermediate conductor pattern in a state where the overlap amount is less than in Fig. 5.

[0042] 6A and 6B , the positions in the depth direction (Y-axis direction) of both the first land portion 30c of the first spiral conductor pattern 30 and the first land portion 34a of the intermediate conductor pattern 34, which are electrically connected via the interlayer connection conductor 42, are adjusted. This makes it possible to adjust the amount of overlap between the first spiral conductor pattern 30 and the intermediate conductor pattern 34. By adjusting the amount of overlap between them, i.e., the capacitance between them, it is possible to adjust the resonant frequency of the coil antenna 14 without substantially changing its electrical length.

[0043] For example, as shown in Fig. 6A, when the overlap amount between the first spiral conductor pattern 30 and the intermediate conductor pattern 34 increases compared to the state shown in Fig. 5, the resonant frequency of the coil antenna 14 decreases compared to the resonant frequency in the state shown in Fig. 5. Also, as shown in Fig. 6B, when the overlap amount decreases compared to the state shown in Fig. 5, the resonant frequency of the coil antenna 14 increases compared to the resonant frequency in the state shown in Fig. 5.

[0044] As shown in Figures 6A and 6B, instead of or in addition to adjusting the depth direction (Y-axis direction) positions of both the first land portion 30c of the first spiral conductor pattern 30 and the first land portion 34a of the intermediate conductor pattern 34, it is also possible to adjust the resonant frequency of the coil antenna 14.

[0045] FIG. 6C is a top view of the first spiral conductor pattern and the intermediate conductor pattern in a state where the overlap amount has been adjusted by a method different from the method of adjusting the overlap amount shown in FIGS. 6A and 6B.

[0046] As shown in Figure 6C, it is also possible to adjust the amount of overlap between the first spiral conductor pattern 30 and the intermediate conductor pattern 34 by adjusting the depth direction (Y-axis direction) positions of the second land portion 34b of the intermediate conductor pattern 34 and the first land portion 32a of the second spiral conductor pattern 32 electrically connected thereto.

[0047] FIG. 6D is a top view of the first spiral conductor pattern and the intermediate conductor pattern in a state where the overlap amount has been adjusted by a method different from the method of adjusting the overlap amount shown in FIGS. 6A, 6B, and 6C.

[0048] As shown in Fig. 6D , the intermediate conductor pattern 34 may overlap the first spiral conductor pattern 30 while being shifted in the width direction relative to the first spiral conductor pattern 30. In the case of Fig. 5 , most of the intermediate conductor pattern 34 overlaps the outer portion of the first spiral conductor pattern 30 over the entire width. In contrast, in Fig. 6D , a portion of the intermediate conductor pattern 34 overlaps the outer portion of the first spiral conductor pattern 30 while being shifted in the width direction. Furthermore, another portion of the intermediate conductor pattern 34 overlaps the inner portion of the first spiral conductor pattern 30 while being shifted in the width direction.

[0049] Therefore, in order to form a capacitance between the first spiral conductor pattern 30, when viewed in the stacking direction (Z-axis direction) of the multilayer substrate 12, the intermediate conductor pattern 34 (excluding the first and second land portions 34a, 34b) only needs to be located between the inner peripheral edge of the inner portion and the outer peripheral edge of the outer portion of the first spiral conductor pattern 30.

[0050] As shown in FIG. 3, the reason why the intermediate conductor pattern 34 is closer to the first spiral conductor pattern 30 than the second spiral conductor pattern 32 is because the molding resin 38 covers the first spiral conductor pattern 30.

[0051] In this embodiment, the reader / writer device of the RFID tag 10, while in close proximity to the coil antenna 14, performs wireless communication with the RFIC chip 16 via the coil antenna 14. At this time, the reader / writer device cannot approach the first spiral conductor pattern 30 of the coil antenna 14 due to the presence of the molded resin 38. Therefore, the reader / writer device performs wireless communication with the RFIC chip 16 via the coil antenna 14 while in close proximity to the second spiral conductor pattern 32.

[0052] In this case, if the intermediate conductor pattern 34 is closer to the second spiral conductor pattern 32 rather than the first spiral conductor pattern 30, there will be strong electromagnetic field coupling between the intermediate conductor pattern 34 and the second spiral conductor pattern 32, weakening the electromagnetic field radiated from the second spiral conductor pattern 32. Therefore, the intermediate conductor pattern 34 is provided at a position away from the second spiral conductor pattern 32, which is brought close to the reader / writer device, and close to the first spiral conductor pattern 30. The intermediate conductor pattern 34 forms a capacitance with the first spiral conductor pattern 30.

[0053] Furthermore, by providing the RFIC chip 16 on the same layer of the multilayer substrate 12 as the first spiral conductor pattern 30, i.e., on a different layer from the second spiral conductor pattern 34, the second spiral conductor pattern 34 can radiate a stronger electromagnetic field without being obstructed by the RFIC chip 16.

[0054] This positional relationship between the RFIC chip 16, the first spiral conductor pattern 30, the second spiral conductor pattern 32, and the intermediate conductor pattern 34 realizes a coil antenna 14 that emits an electromagnetic field mainly from the second spiral conductor pattern 32.

[0055] According to the present embodiment as described above, in the RFID tag 10 equipped with the coil antenna 14, a structure can be realized in which the resonant frequency of the coil antenna 14 can be adjusted without affecting the communication distance of the coil antenna 14.

[0056] That is, by adjusting the amount of overlap of the intermediate conductor pattern 34 with the first spiral conductor pattern 30, the capacitance therebetween is adjusted, thereby adjusting the resonant frequency of the coil antenna 14 without reducing the communication distance.

[0057] Here, for the sake of supplementary explanation, a reduction in the communication distance that may occur when the electrical length of the coil antenna is adjusted to adjust the resonant frequency of the coil antenna will be described.

[0058] FIG. 7 is a schematic diagram of a comparative example RFID tag equipped with a coil antenna.

[0059] 7 , in the RFID tag 110 of the comparative example, when the electrical length of the coil antenna 114 electrically connected to the RFIC chip 116 is adjusted to adjust the resonant frequency, a loop Lp that is smaller than the coil opening Co of the coil antenna 114 may be formed. When such a loop Lp is formed, a portion of the magnetic field Mc passing through the coil opening Co and a portion of the magnetic field Mp passing through the loop Lp cancel each other out. As a result, the communication distance of the coil antenna 114 is reduced.

[0060] Although the present disclosure has been described above with reference to the above-described embodiment, the present disclosure is not limited to this embodiment.

[0061] For example, in the case of the first embodiment described above, as shown in FIG. 2 , the first layer of the multilayer substrate 12 on which the first spiral conductor pattern 30 is provided is provided on one outer surface in the stacking direction (Z-axis direction) of the multilayer substrate 12 (one surface 20a of the first substrate 20). The second layer on which the second spiral conductor pattern 32 is provided is the outer surface on the other side in the stacking direction of the multilayer substrate 12 (the other surface 24b of the second substrate 24). However, the embodiments of the present disclosure are not limited to this. The positions of the first and second layers within the multilayer substrate are not limited as long as there is a third layer between them on which the intermediate conductor pattern 34 is provided.

[0062] That is, various aspects of the present disclosure are as follows.

[0063] A first aspect is an RFID tag having: a multilayer substrate; a coil antenna provided on the multilayer substrate; and an RFIC chip connected to the coil antenna and provided on a first layer of the multilayer substrate, wherein the coil antenna includes: a first spiral conductor pattern provided on the first layer and connected to the RFIC chip; a second spiral conductor pattern provided on a second layer of the multilayer substrate; and a non-spiral intermediate conductor pattern provided on a third layer of the multilayer substrate between the first layer and the second layer and connecting the first spiral conductor pattern and the second spiral conductor pattern, wherein the first spiral conductor pattern is closer to the intermediate conductor pattern in the stacking direction of the multilayer substrate than the second spiral conductor pattern.

[0064] A second aspect is the RFID tag of the first aspect, wherein the intermediate conductor pattern at least partially overlaps the first spiral conductor pattern when viewed in the stacking direction of the multilayer substrate.

[0065] A third aspect is the RFID tag of the second aspect, in which, when viewed in the product direction, the intermediate conductor pattern is located between the inner peripheral edge of the inner portion and the outer peripheral edge of the outer portion of the first spiral conductor pattern.

[0066] A fourth aspect is an RFID tag according to any one of the first to third aspects, wherein the first layer is an outer surface of the multilayer substrate on one side in the stacking direction, and the third layer is an outer surface of the multilayer substrate on the other side in the stacking direction.

[0067] A fifth aspect is the RFID tag of the fourth aspect, wherein the first spiral conductor pattern and the second spiral conductor pattern are equal in electrical length and number of turns.

[0068] A sixth aspect is an RFID tag according to any one of the first to fifth aspects, wherein the multilayer substrate includes: a first substrate having the RFIC chip and the first spiral conductor pattern on one surface; a second substrate having the intermediate conductor pattern on one surface opposite the other surface of the first substrate; and a third substrate having the second spiral conductor pattern on the other surface opposite the one surface opposite the other surface of the second substrate, and wherein the thickness of the first substrate is smaller than the sum of the thicknesses of the second substrate and the third substrate.

[0069] A seventh aspect is the RFID tag of the sixth aspect, wherein a molding resin is provided on one surface of the first substrate to cover and protect the RFIC chip and the first spiral conductor pattern.

[0070] The present disclosure is applicable to RFID tags that include a coil antenna.

Claims

1. A multilayer substrate; a coil antenna provided on the multilayer substrate; an RFIC chip connected to the coil antenna and provided on a first layer of the multilayer substrate; The coil antenna is a first spiral conductor pattern provided on the first layer, surrounding a first electrode portion connected to a first input / output terminal of the RFIC chip and a second electrode portion connected to a second input / output terminal of the RFIC chip, and connected to the RFIC chip; a second spiral conductor pattern provided on a second layer of the multilayer substrate; a non-spiral intermediate conductor pattern provided on a third layer of the multilayer substrate between the first layer and the second layer, the intermediate conductor pattern connecting the first spiral conductor pattern and the second spiral conductor pattern; An RFID tag, wherein the first spiral conductor pattern is closer to the intermediate conductor pattern in the stacking direction of the multilayer substrate than the second spiral conductor pattern.

2. An RFID tag as described in claim 1, wherein the first spiral conductor and the second spiral conductor extend in a spiral shape with one or more turns.

3. An RFID tag as described in claim 1, wherein the intermediate conductor does not extend in a spiral shape with more than one turn.

4. The first spiral conductor and the second spiral conductor extend in a spiral shape with one or more turns, The RFID tag according to claim 1 , wherein the intermediate conductor does not extend in a spiral shape with one or more turns.

5. The RFID tag according to claim 1 , wherein the intermediate conductor pattern at least partially overlaps the first spiral conductor pattern when viewed in the stacking direction of the multilayer substrate.

6. The RFID tag according to claim 5 , wherein the intermediate conductor pattern is located between an inner peripheral edge of an inner portion and an outer peripheral edge of an outer portion of the first spiral conductor pattern when viewed in the stacking direction.

7. the first layer is an outer surface on one side of the multilayer substrate in the stacking direction, The RFID tag according to claim 1 , wherein the third layer is an outer surface of the multilayer substrate on the other side in the stacking direction.

8. The RFID tag according to claim 7 , wherein the first spiral conductor pattern and the second spiral conductor pattern are equal in electrical length and number of turns.

9. The multilayer substrate is a first substrate having the RFIC chip and the first spiral conductor pattern provided on one surface thereof; a second substrate having the intermediate conductor pattern provided on one surface opposite to the other surface of the first substrate; a third substrate having one surface facing the other surface of the second substrate and the second spiral conductor pattern provided on the other surface opposite the other surface of the second substrate, The RFID tag according to claim 7 , wherein the thickness of the first substrate is smaller than the sum of the thickness of the second substrate and the thickness of the third substrate.

10. 10. The RFID tag according to claim 9, wherein a molding resin is provided on one surface of the first substrate to cover and protect the RFIC chip and the first spiral conductor pattern.