Antenna device and IC card provided with same

Abstract

The technical problem of the present invention is to provide an antenna device having improved communication characteristics. This antenna device (1) is provided with a magnetic body (30) having a through-hole (35), and a coil pattern (100). The coil pattern (100) includes: a first encircling portion (110) encircling a plurality of turns along an outer edge of the magnetic body; and a second encircling part (120) that is connected to each turn of the first encircling part (110) and that encircles a plurality of turns in the opposite direction of the first encircling part (110) so as to overlap the through-hole (35) of the magnetic body (30). The second surrounding portion (120) includes an inner peripheral turn (1201) surrounding from a first inner peripheral edge (351) of the through hole (35) along a fourth inner peripheral edge (354), and an outer peripheral turn (1202) surrounding from a second inner peripheral edge (352) along the fourth inner peripheral edge (354) without along the first inner peripheral edge (351) of the through hole (35).

Description

Technical Field

[0001] The present disclosure relates to an antenna device and an IC card having the same. Background Art

[0002] In Patent Document 1 Figure 4 A discloses an antenna device including: a boost antenna having a plurality of turns, and a coupler coil connected to each turn of the boost antenna and having a plurality of turns in a direction opposite to the boost antenna.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: U.S. Patent Application Publication No. 2015 / 0235122 Summary of the invention

[0006] Problem that the invention aims to solve

[0007] However, in the configuration of Patent Document 1, magnetic coupling between the coupling coil and the module antenna included in the chip module is insufficient.

[0008] An object of the present disclosure is to provide an antenna device having improved communication characteristics.

[0009] Means used to solve problems

[0010] An antenna device of one embodiment of the present disclosure comprises: a magnetic body having a through hole; and a coil pattern, the coil pattern including: a first surrounding portion, which is wound around a plurality of turns along an outer edge of the magnetic body; and a second surrounding portion, which is connected to each turn of the first surrounding portion and is wound around a plurality of turns along a direction opposite to the first surrounding portion in a manner overlapping with the through hole of the magnetic body, the through hole of the magnetic body including: a first inner periphery and a third inner periphery, which include a section extending in a first direction and are located on opposite sides to each other; and a second inner periphery and a fourth inner periphery, which include a section extending in a second direction orthogonal to the first direction and are located on opposite sides to each other, the second surrounding portion including: inner peripheral side turns, which are wound around along the first inner peripheral edge, the second inner peripheral edge, the third inner peripheral edge and the fourth inner peripheral edge; and outer peripheral side turns, which are located on the outer side of the inner peripheral side turns and are wound around not along the first inner peripheral edge but along the second inner peripheral edge, the third inner peripheral edge and the fourth inner peripheral edge.

[0011] Effects of the Invention

[0012] According to the present disclosure, it is possible to provide an antenna device having improved communication characteristics. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1It is a schematic perspective view showing the appearance of an IC card 3 including an antenna device according to one embodiment of the present disclosure.

[0014] Figure 2 It is a schematic exploded perspective view for explaining the structure of the IC card 3.

[0015] Figure 3 It is a schematic cross-sectional view for explaining the structure of the IC card 3.

[0016] Figure 4 (a) is Figure 3 A schematic enlargement of region B is shown. Figure 4 (b) shows a state where a substrate 71 is attached. Figure 4 (c) shows a state where the adhesive layer 62 and the base materials 71 and 72 are added.

[0017] Figure 5 yes Figure 3 A schematic enlarged view of a modified example of region B is shown.

[0018] Figure 6 It is a schematic plan view for explaining the structure of the antenna device 1 .

[0019] Figure 7 This is a schematic perspective view of the IC module 50 as viewed from the back side.

[0020] Figure 8 1 is a schematic diagram showing a state in which the IC card 3 and the card reader 6 communicate with each other.

[0021] Fig. 9 It is a schematic plan view for explaining the structure of an antenna device 1A according to a first modification.

[0022] Fig.10 It is a schematic plan view for explaining the structure of an antenna device 1B according to a second modification.

[0023] Fig.11 It is a schematic plan view for explaining the structure of an antenna device 1C according to a third modification.

[0024] Fig.12 2 is a schematic cross-sectional view for explaining a mechanism by which capacitance is obtained by the capacitor electrode pattern 200 .

[0025] Fig.13 It is a schematic plan view for explaining the structure of an antenna device 1D according to a fourth modification.

[0026] Description of Reference Numerals

[0027] 1. 1A~1D Antenna Device

[0028] 3 IC card

[0029] 3a The upper surface of the IC card

[0030] 3b The back of the IC card

[0031] 6 Card reader

[0032] 10 Plastic board

[0033] 30 Magnetic body

[0034] 31 1st outer edge

[0035] 32 2nd outer edge

[0036] 33 The 3rd outer edge

[0037] 34 4th outer edge

[0038] 35 Through hole

[0039] 40 Metal Plate

[0040] 41 Through hole

[0041] 50 IC modules

[0042] 51 Module base plate

[0043] 52 IC chips

[0044] 53 coupling coil

[0045] 54 Protective resin

[0046] 61, 62 Adhesive layer

[0047] 63 Through hole

[0048] 71, 72 Base material

[0049] 100 Coil Pattern

[0050] 101 Outer end of coil pattern

[0051] 102 Inner end of coil pattern

[0052] 110 The first surrounding part

[0053] 110a Opening

[0054] 111 Section 1

[0055] 112 Section 2

[0056] 113 Section 3

[0057] 114 Section 4

[0058] 120 Second Surrounding Part

[0059] 121 Section 1

[0060] 122 Section 2

[0061] 123 Section 3

[0062] 124 Section 4

[0063] 130 The third surrounding part

[0064] 140 The 4th Surrounding Part

[0065] 200 Capacitor electrode pattern

[0066] 201, 202 Linear Pattern

[0067] 351 1st inner periphery

[0068] 352 2nd inner periphery

[0069] 353 3rd inner periphery

[0070] 354 4th inner periphery

[0071] 1001 Main body

[0072] 1002 Seed

[0073] 1003 Bottom

[0074] 1004 Upper surface

[0075] 1111~1114 interval

[0076] 1201 Inner side turn

[0077] 1202 outer side turn

[0078] 1211 1st connection section

[0079] 1212 Second connection section

[0080] C1~C3 Capacitor components

[0081] E terminal electrode DETAILED DESCRIPTION

[0082] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0083] Figure 1 It is a schematic perspective view showing the appearance of an IC card 3 including an antenna device according to one embodiment of the present disclosure.

[0084] like Figure 1As shown, the IC card 3 of this embodiment is a plate-like body with the Y direction as the long side direction, the X direction as the short side direction, and the Z direction as the thickness direction, and has an upper surface 3a and a back surface 3b constituting the XY plane. The IC card 3 is built with an IC module described later, and the terminal electrodes E of the IC module are exposed on the upper surface 3a of the IC card 3.

[0085] Figure 2 and Figure 3 They are respectively a schematic exploded perspective view and a schematic cross-sectional view for explaining the structure of the IC card 3 including the antenna device 1 according to the present embodiment.

[0086] Figure 2 and Figure 3 The IC card 3 shown has a structure in which a plastic plate 10, an adhesive layer 61 and a coil pattern 100 embedded therein, a magnetic body 30, an adhesive layer 62, and a metal plate 40 are stacked in order from the back surface 3b side to the upper surface 3a side. The antenna device 1 of this embodiment is composed of a coil pattern 100 and a magnetic body 30 covering it. Through holes 35, 41, and 63 are respectively provided in the magnetic body 30, the metal plate 40, and the adhesive layer 62. These through holes 35, 41, and 63 have overlaps in the stacking direction, that is, the Z direction.

[0087] The plastic plate 10 is made of a resin material that does not hinder magnetic flux. The outer surface of the plastic plate 10 constitutes the back surface 3b of the IC card 3. The metal plate 40 is made of a metal material such as stainless steel and titanium. The outer surface of the metal plate 40 constitutes the upper surface 3a of the IC card 3. The metal plate 40 is provided with a through hole 41, and an IC module 50 is arranged inside the through hole 41. In this way, the IC card 3 is a card using a metal plate as a main body. The plane position of the inner peripheral edge of the through hole 41 can also be roughly consistent with the plane position of the inner peripheral edge of the through holes 35, 63.

[0088] The plastic plate 10 is covered by the magnetic body 30 via the adhesive layer 61 and the coil pattern 100 embedded therein. The coil pattern 100 has a first surrounding portion 110 and a second surrounding portion 120, which will be described in detail later. As the material of the adhesive layer 61, an acrylic adhesive resin, a material obtained by mixing a ceramic material in an acrylic adhesive resin, etc., etc. can be used. In addition, as the material of the adhesive layer 62, an acrylic double-sided tape, an acrylic adhesive resin, a thermosetting resin, a thermoplastic resin, etc. can be listed, and a material obtained by mixing a ceramic material in an acrylic adhesive resin, etc. can also be used.

[0089] Figure 4 (a) is Figure 3 The schematic enlarged view of the region B shown shows a state before the antenna device 1 of the present embodiment is bonded to the plastic plate 10 and the metal plate 40 .

[0090] exist Figure 4In the example shown in (a) of FIG. 1 , the coil pattern 100 is composed of a main body portion 1001 made of a good conductor such as copper (Cu) and a seed portion 1002 made of a conductive resin material. The coil pattern 100 having such a structure is as shown in FIG. Figure 4 As shown in (b), the main body 1001 can be formed by forming a seed portion 1002 on the surface of a substrate 71 composed of PET (polyethylene terephthalate), PI (polyimide), etc., and then forming the main body 1001 by electroplating the seed portion 1002 as a power supply. Then, an adhesive layer 61 is formed on the surface of the substrate 71 in a manner that the coil pattern 100 is embedded, and the magnetic body 30 is bonded. After that, the substrate 71 is peeled off, and the Figure 4 The magnetic body 30 may be a sheet-like member or may be applied to the surface of the adhesive layer 61. The base material 71 may be peeled off just before the antenna device 1 of this embodiment is bonded to the plastic plate 10. Thus, the handling of the antenna device 1 becomes easy.

[0091] exist Figure 4 In the example shown in (a), the pattern width of the coil pattern 100 becomes narrower as it approaches the magnetic body 30. Therefore, the pattern width P2 of the upper surface 1004 located on the opposite side of the bottom surface 1003 is narrower than the pattern width P1 of the bottom surface 1003 of the coil pattern 100 exposed from the adhesive layer 61. If the coil pattern 100 is set to such a cross-sectional shape, the filling property of the adhesive layer 61 between the patterns is improved.

[0092] Furthermore, if Figure 4 As shown in (c), another base material 72 may be provided on the upper surface of the magnetic body 30 via the adhesive layer 62, and the base materials 71 and 72 may be peeled off just before the antenna device 1 of this embodiment is bonded to the plastic plate 10 and the metal plate 40. Thus, the handling of the antenna device 1 becomes easy, and the assembly of the IC card 3 including the antenna device 1 becomes easy.

[0093] Figure 5 yes Figure 3 The schematic enlarged view of the modified example of the region B shown shows a state before the antenna device 1 of the present embodiment is bonded to the plastic plate 10 and the metal plate 40 .

[0094] exist Figure 5In the example shown, the bottom surface 1003 of the coil pattern 100 is entirely composed of the seed portion 1002, and the main body 1001 is not exposed, which is different from the structure shown in FIG4 (a). That is, the seed portion 1002 is exposed from the surface of the adhesive layer 61, while the main body 1001 is not exposed from the surface of the adhesive layer 61 and is buried in the adhesive layer 61. According to this structure, by using a colored (for example, black) conductive resin material as the material of the seed portion 1002, even if the main body 1001 composed of a good conductor such as copper (Cu) is assumed to be discolored, it is shielded by the colored seed portion 1002, and therefore, there is an advantage that the appearance is not obvious.

[0095] Figure 6 1 is a schematic plan view for explaining the structure of the antenna device 1 according to the present embodiment. Figure 6 The AA line shown indicates Figure 3 The cross-sectional position.

[0096] like Figure 6 As shown, the coil pattern 100 included in the antenna device 1 of the present embodiment includes: a first surrounding portion 110 that surrounds the outer edge of the magnetic body 30 with multiple turns in a manner overlapping the magnetic body 30; and a second surrounding portion 120 that is connected to each turn of the first surrounding portion 110 and surrounds the through hole 35 of the magnetic body 30 with multiple turns. The second surrounding portion 120 overlaps the IC module 50 arranged in the through hole 41 of the metal plate 40 in the Z direction via the through hole 35 of the magnetic body 30.

[0097] exist Figure 6 In the example shown, the first surrounding portion 110 and the second surrounding portion 120 each have approximately 4 turns. The second surrounding portion 120 is a portion that surrounds so as to protrude toward the opening 110a of the first surrounding portion 110. That is, each turn of the coil pattern 100 is composed of the first surrounding portion 110 having less than 1 turn and the second surrounding portion 120 having less than 1 turn.

[0098] The first surround 110 functions as an antenna coil coupled to an external card reader when actually used. The second surround 120 functions as a coupling coil coupled to the IC module 50. The second surround 120 may also function as a part of the antenna coil coupled to the external card reader. The pattern width W11 of the first surround 110 may also be greater than the pattern width W12 of the second surround 120. Thus, the DC resistance of the first surround 110 can be reduced, and the opening size of the second surround 120 can be sufficiently ensured. Here, in the case where the pattern width of the first surround 110 is uneven, the pattern width W11 may be defined according to the maximum pattern width, the minimum pattern width or the average pattern width of the first surround 110. Similarly, in the case where the pattern width of the second surround 120 is uneven, the pattern width W12 may be defined according to the maximum pattern width, the minimum pattern width or the average pattern width of the second surround 120.

[0099] In addition, when the outer peripheral end 101 of the coil pattern 100 is the starting point and the inner peripheral end 102 of the coil pattern 100 is the end point, if Figure 6 When viewed from the direction shown, the first surrounding portion 110 surrounds to the left (counterclockwise), and the second surrounding portion 120 surrounds to the right (clockwise). That is, the first surrounding portion 110 and the second surrounding portion 120 surround in opposite directions.

[0100] The magnetic body 30 includes a first outer edge 31 and a third outer edge 33 extending in the X direction and located on opposite sides to each other, and a second outer edge 32 and a fourth outer edge 34 extending in the Y direction and located on opposite sides to each other. Furthermore, the first encircling portion 110 of the coil pattern 100 includes a first section 111 extending in the X direction along the first outer edge 31 of the magnetic body 30, a second section 112 extending in the Y direction along the second outer edge 32 of the magnetic body 30, a third section 113 extending in the X direction along the third outer edge 33 of the magnetic body 30, and a fourth section 114 extending in the Y direction along the fourth outer edge 34 of the magnetic body 30. Here, with the outer peripheral end 101 of the coil pattern 100 as a starting point and the inner peripheral end 102 of the coil pattern 100 as an end point, the first encircling portion 110 encircles the first section 111, the second section 112, the third section 113, and the fourth section 114 in sequence. Among them, the second section 112 , the third section 113 , and the fourth section 114 are all composed of a continuous conductor pattern extending in a straight line, whereas the first section 111 is cut off in the middle and passes through the second surrounding portion 120 .

[0101] The through hole 35 of the magnetic body 30 is roughly rectangular, and has: the first inner periphery 351 and the third inner periphery 353 extending in the X direction and located on opposite sides to each other, and the second inner periphery 352 and the fourth inner periphery 354 extending in the Y direction and located on opposite sides to each other. However, it is not necessary that the through hole 35 of the magnetic body 30 is roughly rectangular, and it can also be circular, for example. In this case, it can also be that the first inner periphery 351 and the third inner periphery 353 are defined by the interval of the portion extending in the X direction, and the second inner periphery 352 and the fourth inner periphery 354 are defined by the interval of the portion extending in the Y direction. Moreover, the second surrounding portion 120 of the coil pattern 100 has: a first section 121 extending in the X direction along the first inner edge 351 of the magnetic body 30, a second section 122 extending in the Y direction along the second inner edge 352 of the magnetic body 30, a third section 123 extending in the X direction along the third inner edge 353 of the magnetic body 30, and a fourth section 124 extending in the Y direction along the fourth inner edge 354 of the magnetic body 30.

[0102] like Figure 6 As shown in FIG. 1 , the second surrounding portion 120 includes an inner circumferential side turn 1201 located on the inner circumferential side, and an outer circumferential side turn 1202 located on the outer circumferential side relative to the inner circumferential side turn 1201. Figure 6 In the example shown, the inner circumferential side turns 1201 and the outer circumferential side turns 1202 are each about 2 turns. In addition, with the outer circumferential end 101 of the coil pattern 100 as the starting point and the inner circumferential end 102 of the coil pattern 100 as the end point, the inner circumferential side turns 1201 of the second surrounding portion 120 follow the first inner circumferential edge 351 of the through hole 35 along half, the second inner circumferential edge 352, the third inner circumferential edge 353, the fourth inner circumferential edge 354, and the remaining half of the first inner circumferential edge 351, and sequentially surround the first half of the first section 121, the second section 122, the third section 123, the fourth section 124, and the second half of the first section 121. In contrast, when the outer peripheral end 101 of the coil pattern 100 is the starting point and the inner peripheral end 102 of the coil pattern 100 is the end point, the outer peripheral side turn 1202 of the second surrounding portion 120 does not follow the first inner peripheral edge 351 of the through hole 35, but follows the second inner peripheral edge 352, the third inner peripheral edge 353, and the fourth inner peripheral edge 354, and sequentially surrounds the second section 122, the third section 123, and the fourth section 124. In this way, the outer peripheral side turn 1202 of the second surrounding portion 120 does not have the first section 121.

[0103] Here, the direction of the current flowing in the first section 111 of the first surround portion 110 and the direction of the current flowing in the first section 121 of the second surround portion 120 are opposite to each other. Therefore, if the first section 111 of the first surround portion 110 and the first section 121 of the second surround portion 120 are close to each other in the Y direction, magnetic field cancellation occurs, and communication characteristics may be deteriorated due to reduced inductance. However, in this embodiment, compared with including the first section 121 in the inner circumferential side turn 1201 of the second surround portion 120, the first section 121 is not included in the outer circumferential side turn 1202 of the second surround portion 120, so that the distance in the Y direction between the first section 111 of the first surround portion 110 and the first section 121 of the second surround portion 120 can be ensured. As a result, it is possible to suppress the degradation of communication characteristics due to the cancellation of magnetic fields.

[0104] In addition, the coil pattern 100 further includes: a first connection section 1211 extending in the Y direction and connecting the first surrounding portion 110 and the inner peripheral side turn 1201 of the second surrounding portion 120; and a second connection section 1212 extending in the Y direction and connecting the first surrounding portion 110 and the outer peripheral side turn 1202 of the second surrounding portion 120. The first connection section 1211 is densely arranged near the center portion of the through hole 35 in the X direction in a manner that crosses the first inner peripheral edge 351 of the through hole 35. In contrast, the position of the second connection section 1212 in the X direction is located near the second inner peripheral edge 352 or the fourth inner peripheral edge 354 of the through hole 35. Therefore, a space width S2 between the first connection section 1211 and the second connection section 1212 adjacent in the X direction along the first inner peripheral edge 351 of the through hole 35 is larger than a space width S1 between the first connection sections 1211 adjacent in the X direction along the first inner peripheral edge 351 of the through hole 35 .

[0105] Here, the magnetic field intensity is high near the inner periphery of the through hole 41 of the metal plate 40. In this embodiment, since the interval width S2 between the first connection interval 1211 and the second connection interval 1212 is fully ensured, the interference between the magnetic field near the inner periphery of the through hole 41 of the metal plate 40 and the coil pattern 100 is reduced, thereby improving the communication characteristics.

[0106] Figure 7 This is a schematic perspective view of the IC module 50 as viewed from the back side.

[0107] like Figure 7 As shown, the IC module 50 includes a module substrate 51, an IC chip 52 mounted or built in the module substrate 51, and a coupling coil 53. The IC chip 52 is protected by being covered with a dome-shaped protective resin 54. The protective resin 54 is made of an insulating member. Figure 1The terminal electrode E shown. The IC module 50 having such a structure is accommodated in the through hole 41 provided in the metal plate 40. When the IC module 50 is accommodated in the through hole 41, the coupling coil 53 is electromagnetically coupled with the second surrounding portion 120 of the coil pattern 100. Moreover, the second surrounding portion 120 is connected to the first surrounding portion 110 functioning as an antenna coil, so that the IC module 50 can communicate with the outside through the coil pattern 100.

[0108] Therefore, if Figure 8 As shown, if the back side 3b of the IC card 3 faces the card reader 6, the card reader 6 can communicate with the IC chip 52. That is, the card reader 6 is coupled to the coupling coil 53 of the IC module 50 via the coil pattern 100, thereby achieving communication with the IC chip 52.

[0109] As described above, in the antenna device 1 of the present embodiment, the inner peripheral side turns 1201 in the second surrounding portion 120 of the coil pattern 100 are sequentially wound from the first inner peripheral edge 351 of the through hole 35 of the magnetic body 30 along the fourth inner peripheral edge 354, so that the inductance can be improved, and the outer peripheral side turns 1202 are not along the first inner peripheral edge 351 of the through hole 35 of the magnetic body 30 but are sequentially wound from the second inner peripheral edge 352 along the fourth inner peripheral edge 354, so that the reduction of communication characteristics caused by the cancellation of the magnetic field can be suppressed. Moreover, in the present embodiment, since a plurality of turns of the outer peripheral side turns 1202 are provided, the cancellation of the magnetic field can be fully suppressed. In addition, in the present embodiment, since a plurality of inner peripheral side turns 1201 are provided, the coupling with the coupling coil 53 of the IC module 50 can be improved.

[0110] Fig. 9 It is a schematic plan view for explaining the structure of an antenna device 1A according to a first modified example of the present embodiment.

[0111] like Fig. 9 As shown, the antenna device 1A of the first modified example of the present embodiment is different from the antenna device 1 of the above embodiment in that the pattern width W112 of the innermost circumferential turn of the first surrounding portion 110 of the coil pattern 100 is narrower than the pattern width W111 of the other turns of the first surrounding portion 110. Since the other basic structures are the same as those of the antenna device 1 of the above embodiment, the same reference numerals are given to the same elements and repeated descriptions are omitted.

[0112] Here, when the pattern width of the innermost turn of the first surround portion 110 is uneven, the pattern width W112 may be defined according to the maximum pattern width, the minimum pattern width, or the average pattern width of the innermost turn of the first surround portion 110. Similarly, when the pattern width of turns other than the innermost turn of the first surround portion 110 is uneven, the pattern width W111 may be defined according to the maximum pattern width, the minimum pattern width, or the average pattern width of turns other than the innermost turn of the first surround portion 110.

[0113] As in the antenna device 1A of the first modified example, if the pattern width W112 of the innermost turn of the first surround portion 110 of the coil pattern 100 is selectively narrowed, the inductance of the coil pattern 100 can be adjusted without significantly changing other parameters. In the first modified example, the pattern width W112 of the second section 112, the third section 113, and the fourth section 114 of the innermost turn of the first surround portion 110 is narrower than the pattern width of the turns other than the innermost turn of the first surround portion 110.

[0114] Fig.10 It is a schematic plan view for explaining the structure of an antenna device 1B according to a second modified example of the present embodiment.

[0115] like Fig.10 As shown, the antenna device 1B of the second modified example of the present embodiment is different from the antenna device 1 of the above embodiment in that the coil pattern 100 further includes a third surrounding portion 130 and a fourth surrounding portion 140. Since the other basic structures are the same as those of the antenna device 1 of the above embodiment, the same reference numerals are used for the same elements and repeated descriptions are omitted.

[0116] The third surrounding portion 130 is located on the outer peripheral side of the first surrounding portion 110 and is a pattern that surrounds without passing through the second surrounding portion 120. Fig.10 In the example shown, the number of turns of the third surrounding portion 130 is approximately 1 turn. The fourth surrounding portion 140 is located on the inner circumference side of the first surrounding portion 110 and is a pattern that surrounds without passing through the second surrounding portion 120. Fig.10 In the example shown, the number of turns of the fourth winding portion 140 is approximately 5.5 turns.

[0117] The pattern width W13 of the third surrounding portion 130 and the pattern width W14 of the fourth surrounding portion 140 are narrower than the pattern width W11 of the first surrounding portion 110. Here, when the pattern width of the third surrounding portion 130 is uneven, the pattern width W13 may be defined based on the maximum pattern width, the minimum pattern width, or the average pattern width of the third surrounding portion 130. Similarly, when the pattern width of the fourth surrounding portion 140 is uneven, the pattern width W14 may be defined based on the maximum pattern width, the minimum pattern width, or the average pattern width of the fourth surrounding portion 140.

[0118] The third surrounding portion 130 and the fourth surrounding portion 140 of the coil pattern 100 function as a part of the antenna coil, and mainly play a role in adjusting characteristics such as inductance. As shown in the antenna device 1B of the second modified example, if the third surrounding portion 130 and the fourth surrounding portion 140 are added to the coil pattern 100, the inductance can be adjusted more significantly. In addition, since the pattern width W13 of the third surrounding portion 130 and the pattern width W14 of the fourth surrounding portion 140 are narrower than the pattern width W11 of the first surrounding portion 110, the pattern width W11 of the first surrounding portion 110 can be sufficiently ensured, and the number of turns of the third surrounding portion 130 and the fourth surrounding portion 140 can be sufficiently ensured.

[0119] In addition, Fig.10 In the example shown, both the third surrounding portion 130 and the fourth surrounding portion 140 are added to the coil pattern 100, but only one of the third surrounding portion 130 and the fourth surrounding portion 140 may be added to the coil pattern 100. However, by adding both the third surrounding portion 130 and the fourth surrounding portion 140 to the coil pattern 100, the first surrounding portion 110 and the second surrounding portion 120 are located more centrally in the line length of the coil pattern 100, and thus the current density of the current flowing in the first surrounding portion 110 and the second surrounding portion 120 can be increased.

[0120] Moreover, in Fig.10 In the example shown, the interval width S14 between the turns of the fourth surround portion 140 is wider than the interval width S11 between the turns of the first surround portion 110. As a result, the pattern width W11 of the first surround portion 110 can be sufficiently ensured, and the inductance of the coil pattern 100 can be adjusted. The parasitic capacitance generated between the turns of the fourth surround portion 140 can be reduced. Here, in the case where the interval width between the turns of the fourth surround portion 140 is uneven, the interval S14 can also be defined based on the maximum interval width, the minimum interval width, or the average interval width between the turns of the fourth surround portion 140. Similarly, in the case where the interval width between the turns of the first surround portion 110 is uneven, the interval S11 can also be defined based on the maximum interval width, the minimum interval width, or the average interval width between the turns of the first surround portion 110.

[0121] In addition, Fig.10 In the example shown, the number of turns of the inner circumference side turns 1201 of the second surrounding portion 120 is about 3 turns, and the number of turns of the outer circumference side turns 1202 of the second surrounding portion 120 is about 2 turns. In this way, if the number of turns of the inner circumference side turns 1201 is greater than the number of turns of the outer circumference side turns 1202, the coupling between the second surrounding portion 120 and the coupling coil 53 can be further improved.

[0122] Fig.11 It is a schematic plan view for explaining the structure of an antenna device 1C according to a third modified example of the present embodiment.

[0123] like Fig.11 As shown, the antenna device 1C of the third modified example of the present embodiment is different from the antenna device 1 of the above embodiment in that it further includes a capacitor electrode pattern 200 connected to the inner peripheral end 102 of the coil pattern 100. Since the other basic structures are the same as those of the antenna device 1 of the above embodiment, the same reference numerals are used for the same elements and repeated descriptions are omitted.

[0124] The capacitor electrode pattern 200 is arranged in the opening 110a of the first surrounding portion 110 and is connected to the inner peripheral end 102 of the coil pattern 100. The capacitor electrode pattern 200 has: a linear pattern 201 extending in the Y direction and a plurality of linear patterns 202 branching from the linear pattern 201 and extending parallel to the X direction. The extension direction of the linear pattern 202 does not need to be strictly the X direction. In addition, the extension direction of the linear pattern 202 does not need to be a straight line, and it can also be bent midway, or it can be a winding shape in which the extension direction changes periodically. Furthermore, a plurality of linear patterns 202 do not need to be strictly parallel to each other. The capacitor electrode pattern 200 is embedded in the bonding layer 61 in the same manner as the coil pattern 100. Between the capacitor electrode pattern 200 and the magnetic body 30, other conductor patterns that are opposite to the capacitor electrode pattern 200 across an insulating material are not provided. That is, the capacitor electrode pattern 200 overlaps with the magnetic body 30 without being separated by other conductor patterns.

[0125] Fig.12 2 is a schematic cross-sectional view for explaining a mechanism by which capacitance is obtained by the capacitor electrode pattern 200 .

[0126] like Fig.12As shown, although the linear pattern 202 of the capacitor electrode pattern 200 does not have a relative electrode facing each other in the Z direction, capacitance is generated between the linear patterns 202 adjacent to each other in the Y direction. Such capacitance includes not only the component C1 directly generated by the proximity in the Y direction, but also the component C2 generated via the magnetic body 30. Here, when the pattern width of the linear pattern 202 in the X direction is set to W21 and the distance between the linear patterns 202 adjacent to each other in the X direction is set to W22, W21>W22, and the relative area with the magnetic body 30 is fully ensured. The thickness H of the linear pattern 202 in the Z direction is sufficiently small compared to the distance W22 between the patterns, and thus the component C1 directly generated is small.

[0127] However, since the linear pattern 202 overlaps with the magnetic body 30 via the adhesive layer 61, the capacitance is increased by the component C2 generated by the magnetic body 30. The thinner the thickness T61 of the adhesive layer 61, the larger the component C2 of the capacitance, and, in a state where the dielectric constant of the adhesive layer 61 is lower than the dielectric constant of the magnetic body 30, the higher the dielectric constant of the adhesive layer 61, the larger the component C2 of the capacitance. Therefore, the thickness T61 of the adhesive layer 61 may be thinner than the thickness T30 of the magnetic body 30. In addition, the dielectric constant of the magnetic body 30 may be tens to hundreds of times the dielectric constant of the adhesive layer 61. As an example, when the dielectric constant ε of the adhesive layer 61 is less than 10, the dielectric constant ε of the magnetic body 30 may also be about 1000. As described above, the magnetic body 30 may be a sheet-like member or may be coated on the adhesive layer 61. In any case, a material obtained by mixing a magnetic metal powder composed of a Fe-Si-Cr alloy magnetic body, a Fe-Si-Al-Cr alloy magnetic body, or a Fe-Al-Cr alloy magnetic body with a binder resin can be used. Here, in order to further increase the component C2, it is preferred that the magnetic metal powder contained in the magnetic body 30 has a flat shape that is flat in the XY plane direction and thin in the Z direction.

[0128] Furthermore, in the present embodiment, the metal plate 40 is present on the opposite side of the capacitor electrode pattern 200 as viewed from the magnetic body 30, and thus a component C3 is generated via the metal plate 40. The capacitance component C3 is increased by suppressing the expansion of the electric field by the metal plate 40, and the electric field applied to the adhesive layer 61 and the magnetic body 30 that function as a dielectric forming the component C2 is increased, and the electric field expands within the surface of the linear pattern 202, and thus the component C2 becomes larger.

[0129] Due to such a mechanism, although the linear pattern 202 does not have a counter electrode facing each other in the Z direction, it is covered by the magnetic body 30 and the metal plate 40 via the adhesive layer 61 , so that a large capacitance can be obtained by the component C2 .

[0130] Thus, in the antenna device 1C of the third modified example, the capacitor electrode pattern 200 connected to the inner peripheral end 102 of the coil pattern 100 includes a plurality of linear patterns 202, and the linear patterns 202 are covered by the magnetic body 30 and the metal plate 40 via the adhesive layer 61, so that a large capacitance can be obtained without providing a counter electrode. Therefore, the resonant frequency of the antenna device 1C can be easily adjusted even without increasing the number of turns of the coil pattern, and thus, the characteristic degradation caused by the increase in resistance and excessive increase in inductance when the number of turns of the coil pattern is increased can be suppressed.

[0131] In the antenna device 1C of the third modified example, the pattern width in the Y direction of the linear pattern 202 extending in the X direction is reduced at the connection portion with the linear pattern 201 extending in the Y direction. Thus, any linear pattern 202 can be easily cut off from the linear pattern 201 by trimming, so that the capacitance can be finely adjusted.

[0132] Fig.13 It is a schematic plan view for explaining the structure of an antenna device 1D according to a fourth modification.

[0133] like Fig.13 As shown, in the antenna device 1D of the fourth variant of the present embodiment, the first section 111 of the first surrounding portion 110 of the coil pattern 100 includes four sections 1111 to 1114 from the outer peripheral side to the inner peripheral side. The section 1111 includes the outer peripheral end 101 of the coil pattern 100. In addition, the interval width S111 between the radially adjacent sections 1111 and 1112 is larger than the interval width S112 between the radially adjacent sections 1112 and 1113, and the interval width S113 between the radially adjacent sections 1113 and 1114. In addition, in Fig.13 In the example shown, the number of turns of the inner circumference side turns 1201 of the second surrounding portion 120 is about 3 turns, and the number of turns of the outer circumference side turns 1202 of the second surrounding portion 120 is about 1 turn. As the other basic structures are the same as those of the antenna device 1 of the above-mentioned embodiment, the same reference numerals are attached to the same elements, and repeated descriptions are omitted.

[0134] If used Figure 3As described above, the antenna device 1D of the present embodiment is bonded to the plastic plate 10. Here, when the antenna device 1D is bonded to the plastic plate 10, the outer peripheral end 101 of the coil pattern 100 moves from its original position due to the pressure during bonding, and may contact the section 1112 in some cases. However, the antenna device 1D of the present embodiment has a larger spacing width S111 between the section 1111 including the outer peripheral end 101 and the section 1112 located on the inner peripheral side thereof, so that even if the outer peripheral end 101 moves due to the pressure during bonding, a short circuit failure with the section 1112 can be prevented. In addition, with respect to the inner peripheral end 102 of the coil pattern 100, since there is no other part of the coil pattern 100 in the direction (Y direction) that can be moved due to the pressure during bonding, a short circuit failure does not occur even if the vicinity of the inner peripheral end 102 moves due to the pressure during bonding.

[0135] In addition, as illustrated in the antenna device 1D according to the fourth modification, the number of turns of the outer peripheral side turn 1202 may be approximately one turn.

[0136] As mentioned above, although the preferred embodiment of the present disclosure is described, the present disclosure is not limited to the above-mentioned embodiment, and various modifications can be made without departing from the gist of the present disclosure. Such modifications are naturally included in the scope of the present disclosure.

[0137] The technology according to the present disclosure includes the following configuration examples, but the present disclosure is not limited thereto.

[0138] An antenna device of one embodiment of the present disclosure comprises: a magnetic body having a through hole; and a coil pattern, the coil pattern including: a first surrounding portion, which is wound around a plurality of turns along an outer edge of the magnetic body; and a second surrounding portion, which is connected to each turn of the first surrounding portion and is wound around a plurality of turns along a direction opposite to the first surrounding portion in a manner overlapping with the through hole of the magnetic body, the through hole of the magnetic body including: a first inner periphery and a third inner periphery, which include a section extending in a first direction and are located on opposite sides to each other; and a second inner periphery and a fourth inner periphery, which include a section extending in a second direction orthogonal to the first direction and are located on opposite sides to each other, the second surrounding portion including: inner peripheral side turns, which are wound around along the first inner peripheral edge, the second inner peripheral edge, the third inner peripheral edge and the fourth inner peripheral edge; and outer peripheral side turns, which are located on the outer side of the inner peripheral side turns and are wound around not along the first inner peripheral edge but along the second inner peripheral edge, the third inner peripheral edge and the fourth inner peripheral edge. This can suppress the mutual cancellation of magnetic fields in the proximity portion between the first surrounding portion and the second surrounding portion.

[0139] In the above antenna device, the second surround portion may include a plurality of outer peripheral turns. This can more effectively suppress the cancellation of magnetic fields at the close portion of the first surround portion and the second surround portion.

[0140] In the above antenna device, the second surround portion may include a plurality of inner circumference side turns. This can increase the inductance of the second surround portion.

[0141] In the above antenna device, the number of turns of the inner circumference side may be greater than the number of turns of the outer circumference side. This can further increase the inductance of the second surround portion.

[0142] In the above antenna device, the first inner periphery and the third inner periphery may extend in parallel along the first direction, and the second inner periphery and the fourth inner periphery may extend in parallel along the second direction. Thereby, a sufficient area of ​​the through hole can be ensured.

[0143] In the above antenna device, the coil pattern may further include: a first connection section extending in the second direction and connecting the inner peripheral turns of the first surround portion and the second surround portion; and a second connection section extending in the second direction and connecting the outer peripheral turns of the first surround portion and the second surround portion, wherein the spacing width along the first inner peripheral edge of the through hole between the first connection section and the second connection section adjacent in the first direction is greater than the spacing width along the first inner peripheral edge of the through hole between the first connection sections adjacent in the first direction. Thus, when the metal plate and the magnetic body are overlapped, the interference between the magnetic field near the inner peripheral edge of the through hole of the metal plate and the coil pattern can be reduced.

[0144] In the antenna device, the pattern width of at least a portion of the innermost turns of the first surround portion may be narrower than the pattern widths of other turns of the first surround portion. This allows the inductance of the coil pattern to be adjusted without significantly changing other parameters.

[0145] In the above antenna device, the coil pattern may further include: a third surrounding portion, which is located on the outer peripheral side of the first surrounding portion and surrounds without passing through the second surrounding portion. Thus, the inductance of the coil pattern can be increased. In this case, the pattern width of the third surrounding portion may be narrower than the pattern width of at least a part of the pattern of the first surrounding portion. Thus, the pattern width of the first surrounding portion can be sufficiently ensured, and the number of turns of the third surrounding portion can be sufficiently ensured.

[0146] In the above-mentioned antenna device, the coil pattern may also include: a fourth surround portion, which is located on the inner peripheral side than the first surround portion and surrounds without passing through the second surround portion. Thereby, the inductance of the coil pattern can be improved. In this case, the pattern width of the fourth surround portion may be narrower than the pattern width of at least a part of the pattern of the first surround portion. Thereby, the pattern width of the first surround portion can be fully ensured, and the number of turns of the fourth surround portion can be fully ensured. Furthermore, the interval width between the turns of the fourth surround portion may be wider than the interval width between the turns of the first surround portion. Thereby, the pattern width of the first surround portion can be fully ensured, and the inductance of the coil pattern can be adjusted.

[0147] Alternatively, the antenna device may further include: an adhesive layer for bonding the magnetic body and the coil pattern, the coil pattern including: a seed portion formed of a colored conductive resin material; and a main body portion formed of a metal located on the seed portion, the seed layer is exposed from the surface of the adhesive layer, and the main body portion is not exposed from the surface of the adhesive layer but is buried in the adhesive layer. Thus, even if the main body portion is assumed to be discolored, the appearance is not noticeably defective.

[0148] Alternatively, the antenna device may further include: a capacitor electrode pattern connected to the inner peripheral end of the coil pattern, the capacitor electrode pattern including a plurality of linear patterns extending parallel to each other. Thus, the capacitance of the coil pattern can be adjusted. In this case, no other conductor pattern is provided between the capacitor electrode pattern and the magnetic body and opposite to the capacitor electrode pattern via an insulating material. Thus, the manufacturing cost can be suppressed and the capacitance of the coil pattern can be adjusted.

[0149] In the antenna device, the width of the interval between the first section having the outer peripheral end of the coil pattern and the second section adjacent to the first section may be greater than the width of the interval between the second section and the third section adjacent to the second section. Thus, even if the outer peripheral end of the coil pattern moves slightly, a short circuit failure with the second section can be prevented.

[0150] An IC card of one embodiment of the present disclosure comprises: any of the above-mentioned antenna devices; and an IC module, which overlaps with the second surrounding portion of the coil pattern via the through hole of the magnetic body. Thus, the second surrounding portion of the coil pattern can be coupled with the IC module. In this case, the IC card may also comprise: a metal plate covering the magnetic body from the opposite side of the coil pattern, the metal plate having: a through hole on which the IC module is arranged. Thus, an IC card using a metal plate for the main body can be provided.

Claims

1. An antenna device, wherein: have: a magnetic body having a through hole; and Coil pattern, The coil pattern includes: a first surrounding portion, which is wound around a plurality of turns along the outer edge of the magnetic body; and a second surrounding portion, which is connected to each turn of the first surrounding portion and is wound around a plurality of turns in the opposite direction of the first surrounding portion in a manner overlapping with the through hole of the magnetic body. The through hole of the magnetic body includes: a first inner periphery and a third inner periphery, which include a section extending in a first direction and are located on opposite sides to each other; and a second inner periphery and a fourth inner periphery, which include a section extending in a second direction orthogonal to the first direction and are located on opposite sides to each other, The second surrounding portion includes: an inner side turn, which surrounds along the first inner periphery, the second inner periphery, the third inner periphery and the fourth inner periphery; and an outer side turn, which is located closer to the outer periphery than the inner side turn, and surrounds not along the first inner periphery but along the second inner periphery, the third inner periphery and the fourth inner periphery.

2. The antenna device according to claim 1, wherein: The second surrounding portion has a plurality of outer peripheral side turns.

3. The antenna device according to claim 1, wherein: The second surrounding portion has a plurality of inner circumference side turns.

4. The antenna device according to claim 3, wherein: The number of turns of the inner circumference side turns is greater than the number of turns of the outer circumference side turns.

5. The antenna device according to claim 1, wherein: The first inner periphery and the third inner periphery extend parallel to the first direction. The second inner peripheral edge and the fourth inner peripheral edge extend in parallel along the second direction.

6. The antenna device according to claim 1, wherein: The coil pattern further includes: a first connection section extending in the second direction and connecting the inner circumferential side turns of the first surrounding portion and the second surrounding portion; and a second connecting section extending in the second direction and connecting the outer peripheral turns of the first surrounding portion and the second surrounding portion, The spacing width of the first connection section and the second connection section adjacent in the first direction along the first inner peripheral edge of the through hole is larger than the spacing width of the first connection sections adjacent in the first direction along the first inner peripheral edge of the through hole.

7. The antenna device according to claim 1, wherein: A pattern width of at least a portion of the patterns of the innermost turns of the first surrounding portion is narrower than a pattern width of other turns of the first surrounding portion.

8. The antenna device according to claim 1, wherein: The coil pattern further includes a third surrounding portion that is located on the outer peripheral side of the first surrounding portion and surrounds the coil without passing through the second surrounding portion.

9. The antenna device according to claim 8, wherein: The pattern width of the third surrounding portion is narrower than the pattern width of at least a portion of the pattern of the first surrounding portion.

10. The antenna device according to claim 1, wherein: The coil pattern further includes a fourth surrounding portion that is located on an inner peripheral side than the first surrounding portion and surrounds the coil without passing through the second surrounding portion.

11. The antenna device according to claim 10, wherein: The pattern width of the fourth surrounding portion is narrower than the pattern width of at least a portion of the pattern of the first surrounding portion.

12. The antenna device according to claim 10, wherein: The interval width between turns of the fourth surrounding portion is wider than the interval width between turns of the first surrounding portion.

13. The antenna device according to claim 1, wherein: It also includes: a capacitor electrode pattern connected to the inner peripheral end of the coil pattern, The capacitor electrode pattern includes a plurality of linear patterns extending parallel to each other.

14. The antenna device according to claim 13, wherein: No other conductor pattern is provided between the capacitor electrode pattern and the magnetic body so as to face the capacitor electrode pattern via an insulating material.

15. The antenna device according to claim 1, wherein: A width of a gap between a first section including an outer peripheral end of the coil pattern and a second section adjacent to the first section is larger than a width of a gap between the second section and a third section adjacent to the second section.

16. The antenna device according to claim 1, wherein: It also includes: an adhesive layer for bonding the magnetic body and the coil pattern, The coil pattern includes: a seed portion formed of a colored conductive resin material; and a main body portion formed of a metal located on the seed portion. The seed layer is exposed from the surface of the bonding layer, The main body portion is not exposed from the surface of the adhesive layer but is buried in the adhesive layer.

17. An IC card, wherein: have: The antenna device according to any one of claims 1 to 16; and The IC module overlaps the second surrounding portion of the coil pattern via the through hole of the magnetic body.

18. The IC card according to claim 17, wherein: It also includes: a metal plate covering the magnetic body from the opposite side of the coil pattern, The metal plate has a through hole in which the IC module is arranged.

Images