Antenna device and IC card including the same

Abstract

To provide an antenna device having improved communication characteristics.SOLUTION: An antenna device 1 comprises a magnetic body 30 having a through hole 35, and a coil pattern 100. The coil pattern 100 includes: a first circulation portion 110 that circulates along an outer edge of the magnetic body for multiple turns; and a second circulation portion 120 that is connected to each turn of the first circulation portion 110 and circulates in an opposite direction of the first circulation portion 110 for multiple turns so as to overlap with the through hole 35 of the magnetic body 30. The second circulation portion 120 includes: an inner circumferential side turn 1201 that circulates along a fourth inner circumferential edge 354 from a first inner circumferential edge 351 of the through hole 35; and an outer circumferential side turn 1202 that circulates along the fourth inner circumferential edge 354 from the second inner circumferential edge 352 without following along the first inner circumferential edge 351 of the through hole 35.SELECTED DRAWING: Figure 6

Description

[Technical field]

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

[0002] FIG. 4A of Patent Document 1 discloses an antenna device including a booster antenna that makes multiple turns and a coupler coil that is connected to each turn of the booster antenna and makes multiple turns in the opposite direction to the booster antenna. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] US Patent Application Publication No. 2015 / 0235122 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the configuration of Patent Document 1, the magnetic coupling between the coupler coil and the module antenna included in the chip module is not sufficient.

[0005] An object of the present disclosure is to provide an antenna device with improved communication characteristics. [Means for solving the problem]

[0006] An antenna device according to one embodiment of the present disclosure includes a magnetic body having a through hole and a coil pattern, the coil pattern including a first winding portion that winds multiple turns along an outer edge of the magnetic body, and a second winding portion that is connected to each turn of the first winding portion and winds multiple turns in a direction opposite to the first winding portion so as to overlap with the through hole of the magnetic body, the through hole of the magnetic body includes a section extending in a first direction and includes a first inner circumferential edge and a third inner circumferential edge that are located opposite to each other, and a section extending in a second direction perpendicular to the first direction and includes a second inner circumferential edge and a fourth inner circumferential edge that are located opposite to each other, the second winding portion including an inner circumferential turn that winds along the first inner circumferential edge, the second inner circumferential edge, the third inner circumferential edge, and the fourth inner circumferential edge, and an outer circumferential turn that is located outer than the inner circumferential turn and winds along the second inner circumferential edge, the third inner circumferential edge, and the fourth inner circumferential edge without following the first inner circumferential edge. Effect of the Invention

[0007] According to the present disclosure, it is possible to provide an antenna device with improved communication characteristics. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic perspective view showing the appearance of an IC card 3 equipped with an antenna device according to an embodiment of the present disclosure. [Diagram 2] FIG. 2 is a schematic exploded perspective view for explaining the structure of the IC card 3. As shown in FIG. [Diagram 3] FIG. 3 is a schematic cross-sectional view for explaining the structure of the IC card 3. As shown in FIG. [Figure 4] Fig. 4(a) is a schematic enlarged view of region B shown in Fig. 3. Fig. 4(b) shows a state in which substrate 71 has been added, and Fig. 4(c) shows a state in which adhesive layer 62 and substrates 71 and 72 have been added. [Diagram 5] FIG. 5 is a schematic enlarged view of a modified example of the region B shown in FIG. [Figure 6] FIG. 6 is a schematic plan view for explaining the configuration of the antenna device 1. As shown in FIG. [Figure 7]FIG. 7 is a schematic perspective view of the IC module 50 as viewed from the rear side. [Figure 8] FIG. 8 is a schematic diagram showing a state in which the IC card 3 and the card reader 6 are communicating with each other. [Figure 9] FIG. 9 is a schematic plan view for illustrating the configuration of an antenna device 1A according to a first modified example. [Figure 10] FIG. 10 is a schematic plan view for illustrating the configuration of an antenna device 1B according to a second modified example. [Figure 11] FIG. 11 is a schematic plan view illustrating the configuration of an antenna device 1C according to a third modified example. [Figure 12] FIG. 12 is a schematic cross-sectional view for explaining the mechanism by which capacitance is obtained by the capacitor electrode pattern 200. As shown in FIG. [Figure 13] FIG. 13 is a schematic plan view for illustrating the configuration of an antenna device 1D according to a fourth modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

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

[0010] FIG. 1 is a schematic perspective view showing the appearance of an IC card 3 equipped with an antenna device according to an embodiment of the present disclosure.

[0011] 1, the IC card 3 according to this embodiment is a plate-like body with the Y direction as the longitudinal direction, the X direction as the lateral direction, and the Z direction as the thickness direction, and has an upper surface 3a and a back surface 3b that form an XY plane. An IC module, which will be described later, is built into the IC card 3, and terminal electrodes E of the IC module are exposed on the upper surface 3a of the IC card 3.

[0012] 2 and 3 are a schematic exploded perspective view and a schematic cross-sectional view, respectively, for explaining the structure of an IC card 3 including the antenna device 1 according to this embodiment.

[0013] 2 and 3 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 laminated in this order from the back surface 3b side to the top surface 3a side. The antenna device 1 according to this embodiment is composed of the coil pattern 100 and the magnetic body 30 covering it. The magnetic body 30, the metal plate 40, and the adhesive layer 62 are provided with through holes 35, 41, and 63, respectively. These through holes 35, 41, and 63 overlap in the Z direction, which is the lamination direction.

[0014] The plastic plate 10 is made of a resin material that does not impede 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 or titanium. The outer surface of the metal plate 40 constitutes the top surface 3a of the IC card 3. A through hole 41 is provided in the metal plate 40, and an IC module 50 is disposed inside the through hole 41. In this manner, the IC card 3 is a card whose main body uses a metal plate. The planar position of the inner peripheral edge of the through hole 41 may be substantially the same as the planar position of the inner peripheral edges of the through holes 35 and 63.

[0015] The plastic plate 10 is covered with the magnetic body 30 via the adhesive layer 61 and the coil pattern 100 embedded therein. The coil pattern 100 includes a first winding portion 110 and a second winding portion 120, which will be described in detail later. The adhesive layer 61 may be made of an acrylic binder resin or a material obtained by mixing an acrylic binder resin with a ceramic material or the like. The adhesive layer 62 may be made of an acrylic double-sided tape, an acrylic binder resin, a thermosetting resin, a thermoplastic resin, or the like, or may be made of a material obtained by mixing an acrylic binder resin with a ceramic material or the like.

[0016] FIG. 4(a) is a schematic enlarged view of region B shown in FIG. 3, and shows the state before the antenna device 1 according to this embodiment is bonded to the plastic plate 10 and the metal plate 40. As shown in FIG.

[0017] In the example shown in FIG. 4(a), the coil pattern 100 is composed of a main body 1001 made of a good conductor such as copper (Cu) and a seed part 1002 made of a conductive resin material. The coil pattern 100 having such a configuration can be produced by forming the seed part 1002 on the surface of a substrate 71 made of PET (polyethylene terephthalate) or PI (polyimide) as shown in FIG. 4(b), and then forming the main body 1001 by electrolytic plating using the seed part 1002 as a power feeder. Then, an adhesive layer 61 is formed on the surface of the substrate 71 so that the coil pattern 100 is embedded, and after the magnetic body 30 is bonded, the substrate 71 is peeled off to obtain the structure shown in FIG. 4(a). The magnetic body 30 may be a sheet-like member or may be applied to the surface of the adhesive layer 61. The substrate 71 may be peeled off immediately before the antenna device 1 according to this embodiment is bonded to the plastic plate 10. This makes it easier to handle the antenna device 1.

[0018] 4(a), the pattern width of the coil pattern 100 becomes narrower as it approaches the magnetic body 30. For this reason, the pattern width P2 on the top surface 1004 located opposite the bottom surface 1003 of the coil pattern 100 exposed from the adhesive layer 61 is narrower than the pattern width P1 on the bottom surface 1003 of the coil pattern 100 exposed from the adhesive layer 61. If the coil pattern 100 has such a cross-sectional shape, the filling ability of the adhesive layer 61 between the patterns can be improved.

[0019] 4(c), another base material 72 may be provided on the upper surface of the magnetic body 30 via an adhesive layer 62, and the base materials 71, 72 may be peeled off immediately before the antenna device 1 according to this embodiment is bonded to the plastic plate 10 and the metal plate 40. This makes it easier to handle the antenna device 1 and to assemble the IC card 3 including the antenna device 1.

[0020] FIG. 5 is a schematic enlarged view of a modified example of region B shown in FIG. 3, and shows the state before the antenna device 1 according to this embodiment is bonded to the plastic plate 10 and the metal plate 40. As shown in FIG.

[0021] 5, the entire bottom surface 1003 of the coil pattern 100 is formed by the seed portion 1002, and the main body portion 1001 is not exposed, which is different from the structure shown in FIG. 4(a). In other words, the seed portion 1002 is exposed from the surface of the adhesive layer 61, whereas the main body portion 1001 is embedded in the adhesive layer 61 without being exposed from the surface of the adhesive layer 61. This configuration has the advantage that by using a colored (e.g., black) conductive resin material as the material of the seed portion 1002, even if the main body portion 1001 made of a good conductor such as copper (Cu) becomes discolored, the discoloration is concealed by the colored seed portion 1002, making the appearance defect less noticeable.

[0022] 6 is a schematic plan view for explaining the configuration of the antenna device 1 according to this embodiment. Note that the line AA shown in FIG. 6 indicates the cross-sectional position of FIG.

[0023] 6, the coil pattern 100 included in the antenna device 1 according to this embodiment includes a first winding part 110 that winds multiple turns along the outer edge of the magnetic body 30 so as to overlap with the magnetic body 30, and a second winding part 120 that is connected to each turn of the first winding part 110 and winds multiple turns so as to overlap with the through hole 35 of the magnetic body 30. The second winding part 120 overlaps in the Z direction with the IC module 50 arranged in the through hole 41 of the metal plate 40 via the through hole 35 of the magnetic body 30.

[0024] 6, the first winding portion 110 and the second winding portion 120 each have about four turns. The second winding portion 120 is a portion that winds around so as to protrude toward the opening 110a of the first winding portion 110. In other words, each turn of the coil pattern 100 is made up of the first winding portion 110 having less than one turn and the second winding portion 120 having less than one turn.

[0025] The first winding part 110 functions as an antenna coil that is coupled to an external card reader during actual use. The second winding part 120 functions as a coupling coil that is coupled to the IC module 50. The second winding part 120 may function as a part of an antenna coil that is coupled to an external card reader. The pattern width W11 of the first winding part 110 may be larger than the pattern width W12 of the second winding part 120. This reduces the direct current resistance of the first winding part 110 and allows the opening size of the second winding part 120 to be sufficiently secured. Here, when the pattern width of the first winding part 110 is not uniform, the pattern width W11 may be defined by the maximum pattern width, minimum pattern width, or average pattern width of the first winding part 110. Similarly, when the pattern width of the second winding part 120 is not uniform, the pattern width W12 may be defined by the maximum pattern width, minimum pattern width, or average pattern width of the second winding part 120.

[0026] In addition, when the outer circumferential end 101 of the coil pattern 100 is taken as the starting point and the inner circumferential end 102 of the coil pattern 100 is taken as the end point, the first winding part 110 winds left (counterclockwise) and the second winding part 120 winds right (clockwise) when viewed from the direction shown in Fig. 6. In other words, the winding directions of the first winding part 110 and the second winding part 120 are opposite to each other.

[0027] The magnetic body 30 has a first outer edge 31 and a third outer edge 33 that extend in the X direction and are located opposite to each other, and a second outer edge 32 and a fourth outer edge 34 that extend in the Y direction and are located opposite to each other. The first winding part 110 of the coil pattern 100 has a first section 111 that extends in the X direction along the first outer edge 31 of the magnetic body 30, a second section 112 that extends in the Y direction along the second outer edge 32 of the magnetic body 30, a third section 113 that extends in the X direction along the third outer edge 33 of the magnetic body 30, and a fourth section 114 that extends in the Y direction along the fourth outer edge 34 of the magnetic body 30. Here, when the outer circumferential end 101 of the coil pattern 100 is taken as the starting point and the inner circumferential end 102 of the coil pattern 100 is taken as the end point, the first winding part 110 winds in the order of the first section 111, the second section 112, the third section 113, and the fourth section 114. Of these, 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 divided midway and passes through the second winding portion 120.

[0028] The through hole 35 of the magnetic body 30 is substantially rectangular, and has a first inner peripheral edge 351 and a third inner peripheral edge 353 that extend in the X direction and are located on opposite sides to each other, and a second inner peripheral edge 352 and a fourth inner peripheral edge 354 that extend in the Y direction and are located on opposite sides to each other. However, it is not essential that the through hole 35 of the magnetic body 30 is substantially rectangular, and it may be, for example, circular. In this case, the first inner peripheral edge 351 and the third inner peripheral edge 353 may be defined by a section including a portion extending in the X direction, and the second inner peripheral edge 352 and the fourth inner peripheral edge 354 may be defined by a section including a portion extending in the Y direction. The second winding portion 120 of the coil pattern 100 has a first section 121 extending in the X direction along the first inner peripheral edge 351 of the magnetic body 30, a second section 122 extending in the Y direction along the second inner peripheral edge 352 of the magnetic body 30, a third section 123 extending in the X direction along the third inner peripheral edge 353 of the magnetic body 30, and a fourth section 124 extending in the Y direction along the fourth inner peripheral edge 354 of the magnetic body 30.

[0029] As shown in Fig. 6, the second winding part 120 has 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 of the inner circumferential side turn 1201. In the example shown in Fig. 6, the inner circumferential side turn 1201 and the outer circumferential side turn 1202 each have about two turns. When the outer circumferential end 101 of the coil pattern 100 is taken as the starting point and the inner circumferential end 102 of the coil pattern 100 is taken as the end point, the inner circumferential side turn 1201 of the second winding part 120 winds along half of the first inner circumferential edge 351 of the through hole 35, 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, in the order of 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 circumferential turn 1202 of the second winding part 120 starts from the outer circumferential end 101 of the coil pattern 100 and ends at the inner circumferential end 102 of the coil pattern 100, it winds along the second inner circumferential edge 352, the third inner circumferential edge 353, and the fourth inner circumferential edge 354, in that order, through the second section 122, the third section 123, and the fourth section 124, without following the first inner circumferential edge 351 of the through hole 35. In this way, the outer circumferential turn 1202 of the second winding part 120 does not have the first section 121.

[0030] Here, the direction of the current flowing in the first section 111 of the first winding section 110 and the direction of the current flowing in the first section 121 of the second winding section 120 are opposite to each other. Therefore, when the first section 111 of the first winding section 110 and the first section 121 of the second winding section 120 approach each other in the Y direction, the magnetic fields cancel each other out, and the communication characteristics may deteriorate due to a decrease in inductance. However, in this embodiment, the first section 121 is included in the inner circumference side turn 1201 of the second winding section 120, whereas the first section 121 is not included in the outer circumference side turn 1202 of the second winding section 120, so that the distance in the Y direction between the first section 111 of the first winding section 110 and the first section 121 of the second winding section 120 is secured. This makes it possible to suppress the deterioration of the communication characteristics caused by the cancellation of the magnetic fields.

[0031] The coil pattern 100 further includes a first connection section 1211 extending in the Y direction and connecting the inner circumferential turn 1201 of the first winding part 110 and the second winding part 120, and a second connection section 1212 extending in the Y direction and connecting the outer circumferential turn 1202 of the first winding part 110 and the second winding part 120. The first connection sections 1211 are densely arranged near the center of the through hole 35 in the X direction so as to cross the first inner circumferential 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 circumferential edge 352 or the fourth inner circumferential edge 354 of the through hole 35. Therefore, the space width S2 along the first inner edge 351 of the through hole 35 between the first connection section 1211 and the second connection section 1212 adjacent in the X direction is larger than the space width S1 along the first inner edge 351 of the through hole 35 between the first connection sections 1211 adjacent in the X direction.

[0032] Here, the magnetic field strength is high near the inner peripheral edge of the through hole 41 of the metal plate 40. In this embodiment, the space width S2 between the first connection section 1211 and the second connection section 1212 is sufficiently secured, so that interference between the magnetic field near the inner peripheral edge of the through hole 41 of the metal plate 40 and the coil pattern 100 is reduced, thereby improving communication characteristics.

[0033] FIG. 7 is a schematic perspective view of the IC module 50 as viewed from the rear side.

[0034] As shown in FIG. 7, 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 material. A terminal electrode E shown in FIG. 1 is provided on the front surface side of the module substrate 51. The IC module 50 having such a configuration is accommodated in a through hole 41 provided in a metal plate 40. When the IC module 50 is accommodated in the through hole 41, the coupling coil 53 and the second winding part 120 of the coil pattern 100 are electromagnetically coupled. The second winding part 120 is connected to the first winding part 110 that functions as an antenna coil, and therefore the IC module 50 can communicate with the outside via the coil pattern 100.

[0035] 8, when the back surface 3b of the IC card 3 is faced to the card reader 6, communication can be performed between the card reader 6 and the IC chip 52. In other words, the card reader 6 is coupled to the coupling coil 53 of the IC module 50 via the coil pattern 100, thereby realizing communication with the IC chip 52.

[0036] As described above, in the antenna device 1 according to this embodiment, the inner circumferential turn 1201 of the second winding portion 120 of the coil pattern 100 winds in this order from the first inner circumferential edge 351 to the fourth inner circumferential edge 354 of the through hole 35 of the magnetic body 30, thereby increasing the inductance, and the outer circumferential turn 1202 winds in this order from the second inner circumferential edge 352 to the fourth inner circumferential edge 354 without following the first inner circumferential edge 351 of the through hole 35 of the magnetic body 30, thereby suppressing the deterioration of communication characteristics due to cancellation of magnetic fields. Moreover, in this embodiment, the outer circumferential turn 1202 is provided with a plurality of turns, thereby making it possible to sufficiently suppress cancellation of magnetic fields. Also, in this embodiment, the inner circumferential turn 1201 is provided with a plurality of turns, thereby enhancing the coupling with the coupling coil 53 of the IC module 50.

[0037] FIG. 9 is a schematic plan view for explaining the configuration of an antenna device 1A according to a first modified example of this embodiment.

[0038] 9, antenna device 1A according to a first modified example of this embodiment differs from antenna device 1 according to the above embodiment in that the pattern width W112 of the innermost turn of first winding part 110 of coil pattern 100 is narrower than the pattern width W111 of the other turns of first winding part 110. As the other basic configuration is the same as that of antenna device 1 according to the above embodiment, the same elements are given the same reference numerals and redundant explanations will be omitted.

[0039] Here, when the pattern width of the innermost turn of the first winding part 110 is not uniform, the pattern width W112 may be defined by the maximum pattern width, minimum pattern width, or average pattern width of the innermost turn of the first winding part 110. Similarly, when the pattern widths of turns other than the innermost turn of the first winding part 110 are not uniform, the pattern width W111 may be defined by the maximum pattern width, minimum pattern width, or average pattern width of turns other than the innermost turn of the first winding part 110.

[0040] As in the antenna device 1A according to the first modification, by selectively narrowing the pattern width W112 of the innermost turn of the first winding part 110 of the coil pattern 100, it is possible to adjust the inductance of the coil pattern 100 without significantly changing other parameters. In the first modification, the pattern widths W112 of the second section 112, the third section 113, and the fourth section 114 of the innermost turn of the first winding part 110 are narrower than the pattern widths of the turns of the first winding part 110 other than the innermost turn.

[0041] FIG. 10 is a schematic plan view for explaining the configuration of an antenna device 1B according to a second modified example of this embodiment.

[0042] 10, antenna device 1B according to a second modification of this embodiment differs from antenna device 1 according to the above embodiment in that coil pattern 100 further includes a third winding portion 130 and a fourth winding portion 140. Since other basic configurations are the same as those of antenna device 1 according to the above embodiment, the same elements are denoted by the same reference numerals and redundant explanations will be omitted.

[0043] The third winding portion 130 is located on the outer periphery side of the first winding portion 110, and has a winding pattern without passing through the second winding portion 120. In the example shown in Fig. 10, the number of turns of the third winding portion 130 is about 1 turn. The fourth winding portion 140 is located on the inner periphery side of the first winding portion 110, and has a winding pattern without passing through the second winding portion 120. In the example shown in Fig. 10, the number of turns of the fourth winding portion 140 is about 5.5 turns.

[0044] The pattern width W13 of the third winding part 130 and the pattern width W14 of the fourth winding part 140 are narrower than the pattern width W11 of the first winding part 110. Here, when the pattern width of the third winding part 130 is not uniform, the pattern width W13 may be defined by the maximum pattern width, the minimum pattern width, or the average pattern width of the third winding part 130. Similarly, when the pattern width of the fourth winding part 140 is not uniform, the pattern width W14 may be defined by the maximum pattern width, the minimum pattern width, or the average pattern width of the fourth winding part 140.

[0045] Although the third winding part 130 and the fourth winding part 140 of the coil pattern 100 function as a part of the antenna coil, they mainly play a role in adjusting characteristics such as inductance. As exemplified by the antenna device 1B according to the second modified example, by adding the third winding part 130 and the fourth winding part 140 to the coil pattern 100, it becomes possible to adjust the inductance to a larger extent. Moreover, since the pattern width W13 of the third winding part 130 and the pattern width W14 of the fourth winding part 140 are narrower than the pattern width W11 of the first winding part 110, it becomes possible to ensure a sufficient number of turns of the third winding part 130 and the fourth winding part 140 while ensuring a sufficient pattern width W11 of the first winding part 110.

[0046] 10, both the third winding portion 130 and the fourth winding portion 140 are added to the coil pattern 100, but only one of the third winding portion 130 and the fourth winding portion 140 may be added to the coil pattern 100. However, by adding both the third winding portion 130 and the fourth winding portion 140 to the coil pattern 100, the first winding portion 110 and the second winding portion 120 are positioned closer to the center of the line length of the coil pattern 100, and the current density of the current flowing through the first winding portion 110 and the second winding portion 120 is increased.

[0047] Further, in the example shown in FIG. 10, the space width S14 between the turns of the fourth winding part 140 is wider than the space width S11 between the turns of the first winding part 110. This makes it possible to adjust the inductance of the coil pattern 100 while sufficiently securing the pattern width W11 of the first winding part 110. It is possible to reduce the parasitic capacitance generated between the turns of the fourth winding part 140. Here, if the space width between the turns of the fourth winding part 140 is not uniform, the space S14 may be defined by the maximum space width, minimum space width, or average space width between the turns of the fourth winding part 140. Similarly, if the space width between the turns of the first winding part 110 is not uniform, the space S11 may be defined by the maximum space width, minimum space width, or average space width between the turns of the first winding part 110.

[0048] 10, the number of turns of the inner circumference side turn 1201 of the second winding part 120 is about 3 turns, and the number of turns of the outer circumference side turn 1202 of the second winding part 120 is about 2 turns. In this way, by making the number of turns of the inner circumference side turn 1201 greater than the number of turns of the outer circumference side turn 1202, it is possible to further enhance the coupling between the second winding part 120 and the coupling coil 53.

[0049] FIG. 11 is a schematic plan view for explaining the configuration of an antenna device 1C according to a third modified example of this embodiment.

[0050] 11, the antenna device 1C according to the third modification of this embodiment differs from the antenna device 1 according to the above embodiment in that it further includes a capacitor electrode pattern 200 connected to the inner circumferential end 102 of the coil pattern 100. Since the other basic configurations are the same as those of the antenna device 1 according to the above embodiment, the same elements are denoted by the same reference numerals and redundant explanations will be omitted.

[0051] The capacitor electrode pattern 200 is disposed in the opening 110a of the first winding part 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 have to be strictly the X direction. In addition, the extension direction of the linear pattern 202 does not have to be linear, and it may be bent midway, or may be a meandering shape in which the extension direction changes periodically. Furthermore, the plurality of linear patterns 202 do not have to be strictly parallel to each other. The capacitor electrode pattern 200 is embedded in the adhesive layer 61, similar to the coil pattern 100. Between the capacitor electrode pattern 200 and the magnetic body 30, no other conductor pattern is provided that faces the capacitor electrode pattern 200 via an insulating material. In other words, the capacitor electrode pattern 200 overlaps with the magnetic body 30 without any other conductor pattern therebetween.

[0052] FIG. 12 is a schematic cross-sectional view for explaining the mechanism by which capacitance is obtained by the capacitor electrode pattern 200. As shown in FIG.

[0053] 12, although the linear patterns 202 of the capacitor electrode pattern 200 do not have opposing electrodes facing each other in the Z direction, capacitance occurs between the linear patterns 202 adjacent in the Y direction. Such capacitance includes not only a component C1 that occurs directly due to the adjacency in the Y direction, but also a component C2 that occurs via the magnetic body 30. Here, if the pattern width of the linear patterns 202 in the X direction is W21 and the distance between the linear patterns 202 adjacent in the X direction is W22, W21>W22, and the opposing area with the magnetic body 30 is sufficiently secured. The thickness H of the linear patterns 202 in the Z direction is sufficiently smaller than the distance W22 between the patterns, and therefore the component C1 that occurs directly is small.

[0054] 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 via the magnetic body 30. The capacitance component C2 increases as the thickness T61 of the adhesive layer 61 becomes thinner, and also increases as the dielectric constant of the adhesive layer 61 becomes higher in a state in which the dielectric constant of the adhesive layer 61 is lower than that of the magnetic body 30. For this reason, the thickness T61 of the adhesive layer 61 may be thinner than the thickness T30 of the magnetic body 30. The dielectric constant of the magnetic body 30 may be several tens to several hundreds times that of the adhesive layer 61. As an example, when the dielectric constant ε of the adhesive layer 61 is 10 or less, the dielectric constant ε of the magnetic body 30 may 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 either case, a material obtained by mixing a magnetic metal powder made of a Fe-Si-Cr based magnetic alloy, a Fe-Si-Al-Cr based magnetic alloy, or a Fe-Al-Cr based magnetic alloy, etc. with a binder resin can be used. Here, in order to further increase component C2, it is desirable that the magnetic metal powder contained in the magnetic body 30 has a flat shape that is flattened in the XY plane direction and has a small thickness in the Z direction.

[0055] Furthermore, in this embodiment, since the metal plate 40 is present on the opposite side of the capacitor electrode pattern 200 as viewed from the magnetic body 30, a component C3 is generated via the metal plate 40. The electric field applied to the adhesive layer 61 and the magnetic body 30, which function as a dielectric forming the component C2, is increased by the capacitive component C3 increased by the metal plate 40 as a result of the spread of the electric field being suppressed, and the electric field spreads within the plane of the linear pattern 202, so that the component C2 becomes large.

[0056] Due to this mechanism, although the linear pattern 202 does not have an opposing electrode facing in the Z direction, it is covered by the magnetic body 30 and the metal plate 40 via the adhesive layer 61, making it possible to obtain a large capacitance due to the component C2.

[0057] In this way, in the antenna device 1C according to the third modification, the capacitor electrode pattern 200 connected to the inner circumferential end 102 of the coil pattern 100 includes a plurality of linear patterns 202, and the linear patterns 202 are covered with the magnetic body 30 and the metal plate 40 via the adhesive layer 61, so that it is possible to obtain a large capacitance without providing a counter electrode. Therefore, since the resonant frequency of the antenna device 1C can be easily adjusted without increasing the number of turns of the coil pattern, it is possible to suppress characteristic degradation due to an increase in resistance and an excessive increase in inductance when the number of turns of the coil pattern is increased.

[0058] In addition, in the antenna device 1C according to the third modification, 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. This makes it possible to easily separate any number of linear patterns 202 from the linear pattern 201 by trimming, thereby enabling fine adjustment of the capacitance.

[0059] FIG. 13 is a schematic plan view for illustrating the configuration of an antenna device 1D according to a fourth modified example.

[0060] As shown in FIG. 13, in the antenna device 1D according to the fourth modification of this embodiment, the first section 111 of the first winding part 110 of the coil pattern 100 includes four sections 1111 to 1114 from the outer periphery side to the inner periphery side. The section 1111 includes the outer periphery end 101 of the coil pattern 100. The space width S111 between the section 1111 and the section 1112 adjacent in the radial direction is larger than the space width S112 between the section 1112 and the section 1113 adjacent in the radial direction, and the space width S113 between the section 1113 and the section 1114 adjacent in the radial direction. In the example shown in FIG. 13, the number of turns of the inner periphery side turn 1201 of the second winding part 120 is about 3 turns, and the number of turns of the outer periphery side turn 1202 of the second winding part 120 is about 1 turn. Other basic configurations are the same as those of the antenna device 1 according to the above embodiment, so the same elements are given the same reference numerals and redundant explanations are omitted.

[0061] The antenna device 1D according to this embodiment is bonded to the plastic plate 10 as described with reference to FIG. 3. Here, when the antenna device 1D is bonded to the plastic plate 10, the outer peripheral end 101 of the coil pattern 100 may move from its original position due to pressure during bonding, and may possibly come into contact with the section 1112. However, in the antenna device 1D according to this embodiment, the space width S111 between the section 1111 including the outer peripheral end 101 and the section 1112 located on the inner periphery side thereof is enlarged, so that even if the outer peripheral end 101 moves due to pressure during bonding, it is possible to prevent a short circuit failure with the section 1112. Also, with regard 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) in which it may move due to pressure during bonding, no short circuit failure occurs even if the vicinity of the inner peripheral end 102 moves due to pressure during bonding.

[0062] As exemplified by antenna device 1D according to a fourth modified example, the number of turns of outer periphery turn 1202 may be approximately one turn.

[0063] Although the above describes preferred embodiments of the present disclosure, the present disclosure is not limited to the above-described embodiments, and various modifications are possible without departing from the spirit of the present disclosure, and it goes without saying that these modifications are also included within the scope of the present disclosure.

[0064] The technology according to the present disclosure includes the following configuration examples, but is not limited to these.

[0065] An antenna device according to one embodiment of the present disclosure includes a magnetic body having a through hole and a coil pattern, the coil pattern including a first winding portion that winds multiple turns along an outer edge of the magnetic body, and a second winding portion that is connected to each turn of the first winding portion and winds multiple turns in a direction opposite to the first winding portion so as to overlap with the through hole of the magnetic body, the through hole of the magnetic body includes a section extending in a first direction and includes a first inner circumferential edge and a third inner circumferential edge that are located opposite to each other, and a section extending in a second direction perpendicular to the first direction and includes a second inner circumferential edge and a fourth inner circumferential edge that are located opposite to each other, the second winding portion including an inner circumferential turn that winds along the first inner circumferential edge, the second inner circumferential edge, the third inner circumferential edge, and the fourth inner circumferential edge, and an outer circumferential turn that is located outer than the inner circumferential turn and winds along the second inner circumferential edge, the third inner circumferential edge, and the fourth inner circumferential edge without following the first inner circumferential edge. This makes it possible to suppress cancellation of magnetic fields in the adjacent portions of the first winding portion and the second winding portion.

[0066] In the above antenna device, the second winding part may have a plurality of outer circumferential turns, which makes it possible to more effectively suppress the cancellation of magnetic fields in the adjacent portions of the first winding part and the second winding part.

[0067] In the above antenna device, the second winding portion may have a plurality of inner turns, which makes it possible to increase the inductance of the second winding portion.

[0068] In the above antenna device, the number of turns of the inner circumferential turn may be greater than the number of turns of the outer circumferential turn, which makes it possible to further increase the inductance of the second winding portion.

[0069] In the above antenna device, the first and third inner circumferential edges may extend parallel to each other in the first direction, and the second and fourth inner circumferential edges may extend parallel to each other in the second direction, thereby making it possible to ensure a sufficient area for the through hole.

[0070] In the above antenna device, the coil pattern further includes a first connection section extending in the second direction and connecting the inner turns of the first winding part and the second winding part, and a second connection section extending in the second direction and connecting the outer turns of the first winding part and the second winding part, and the space width along the first inner edge of the through hole between the first connection section and the second connection section adjacent in the first direction may be larger than the space width along the first inner edge of the through hole between the first connection sections adjacent in the first direction. This makes it possible to reduce interference between the magnetic field near the inner edge of the through hole of the metal plate and the coil pattern when a metal plate is placed on the magnetic body.

[0071] In the above antenna device, the pattern width of at least a part of the pattern of the innermost turn of the first winding part may be narrower than the pattern width of the other turns of the first winding part, which makes it possible to adjust the inductance of the coil pattern without significantly changing other parameters.

[0072] In the above antenna device, the coil pattern may further include a third winding portion that is located on the outer periphery side of the first winding portion and winds around without passing through the second winding portion. This makes it possible to increase the inductance of the coil pattern. In this case, the pattern width of the third winding portion may be narrower than the pattern width of at least a part of the pattern of the first winding portion. This makes it possible to ensure a sufficient number of turns of the third winding portion while ensuring a sufficient pattern width of the first winding portion.

[0073] In the above antenna device, the coil pattern may further include a fourth winding portion located on the inner periphery side of the first winding portion and winding without passing through the second winding portion. This makes it possible to increase the inductance of the coil pattern. In this case, the pattern width of the fourth winding portion may be narrower than the pattern width of at least a part of the pattern of the first winding portion. This makes it possible to ensure a sufficient number of turns of the fourth winding portion while ensuring a sufficient pattern width of the first winding portion. Furthermore, the space width between the turns of the fourth winding portion may be wider than the space width between the turns of the first winding portion. This makes it possible to adjust the inductance of the coil pattern while ensuring a sufficient pattern width of the first winding portion.

[0074] The antenna device further includes an adhesive layer that bonds the magnetic body and the coil pattern, the coil pattern having a seed portion made of a colored conductive resin material and a body portion made of a metal located on the seed portion, the seed layer being exposed from the surface of the adhesive layer, and the body portion being embedded in the adhesive layer without being exposed from the surface of the adhesive layer. In this way, even if the body portion is discolored, the appearance defect is not noticeable.

[0075] The antenna device may further include a capacitor electrode pattern connected to an inner peripheral end of the coil pattern, and the capacitor electrode pattern may include a plurality of linear patterns extending parallel to each other. This makes it possible to adjust the capacitance of the coil pattern. In this case, it is not necessary to provide another conductor pattern facing the capacitor electrode pattern via an insulating material between the capacitor electrode pattern and the magnetic body. This makes it possible to adjust the capacitance of the coil pattern while suppressing manufacturing costs.

[0076] In the above antenna device, the space between the first section including the outer circumferential end of the coil pattern and the second section adjacent to the first section may be larger than the space between the second section and the third section adjacent to the second section. This makes it possible to prevent short circuit defects with the second section even if the outer circumferential end of the coil pattern moves slightly.

[0077] An IC card according to an embodiment of the present disclosure includes any one of the antenna devices described above and an IC module that overlaps with the second winding part of the coil pattern via a through hole in the magnetic body. This makes it possible to couple the second winding part of the coil pattern with the IC module. In this case, the IC card further includes a metal plate that covers the magnetic body from the side opposite to the coil pattern, and the metal plate may have a through hole in which the IC module is disposed. This makes it possible to provide an IC card in which a metal plate is used in the main body. [Explanation of symbols]

[0078] 1,1A~1D Antenna device 3. IC Card 3a Top of IC card 3b Back of IC card 6. Card Reader 10 Plastic Plates 30 Magnetic material 31 First Outer Edge 32 Second Outer Edge 33 Third Outer Edge 34 Fourth Outer Edge 35 Through hole 40 Metal Plate 41 Through hole 50 IC Module 51 Module Board 52 IC chip 53 Coupling coil 54 Protective resin 61,62 Adhesive layer 63 Through hole 71,72 Base material 100 coil pattern 101 Outer end of coil pattern 102 Inner end of coil pattern 110 1st Lap 110a aperture 111 First Section 112 Second Section 113 Section 3 114 Section 4 120 2nd lap section 121 First Section 122 Second Section 123 Third Section 124 Section 4 130 3rd lap section 140 4th lap section 200 Capacitor electrode pattern 201,202 Linear Pattern 351 First inner edge 352 2nd inner edge 353 3rd inner edge 354 4th inner edge 1001 Main body 1002 Seed Section 1003 Bottom 1004 Top surface 1111~1114 section 1201 Inner Turn 1202 Outer Turn 1211 First connecting section 1212 2nd connecting section C1~C3 Capacity component E terminal electrode

Claims

1. A magnetic body having a through hole; The coil pattern, Equipped with the coil pattern includes a first winding portion that winds around an outer edge of the magnetic body for a plurality of turns, and a second winding portion that winds around the magnetic body for a plurality of turns in a direction opposite to the direction of the first winding portion and that is connected to each turn of the first winding portion and overlaps with the through hole of the magnetic body; the through hole of the magnetic body includes a section extending in a first direction, and includes a first inner peripheral edge and a third inner peripheral edge located opposite each other, and includes a section extending in a second direction perpendicular to the first direction, and includes a second inner peripheral edge and a fourth inner peripheral edge located opposite each other, the second winding portion includes an inner circumferential side turn that winds along the first inner circumferential edge, the second inner circumferential edge, the third inner circumferential edge, and the fourth inner circumferential edge, and an outer circumferential side turn that is located outer than the inner circumferential side turn and winds along the second inner circumferential edge, the third inner circumferential edge, and the fourth inner circumferential edge without following the first inner circumferential edge, Antenna device.

2. The second winding portion has a plurality of turns of the outer circumferential side turn.

2. The antenna device according to claim 1.

3. The second winding portion has a plurality of turns on the inner circumferential side.

2. The antenna device according to claim 1.

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

5. the first inner peripheral edge and the third inner peripheral edge extend parallel to each other along the first direction, The second inner peripheral edge and the fourth inner peripheral edge extend parallel to each other along the second direction.

2. The antenna device according to claim 1.

6. the coil pattern further includes a first connection section extending in the second direction and connecting the inner circumferential turn of the first winding portion and the inner circumferential turn of the second winding portion, and a second connection section extending in the second direction and connecting the outer circumferential turn of the first winding portion and the outer circumferential turn of the second winding portion, a space width along the first inner peripheral edge of the through hole between the first connection section and the second connection section adjacent to each other in the first direction is larger than a space width along the first inner peripheral edge of the through hole between the first connection sections adjacent to each other in the first direction; 2. The antenna device according to claim 1.

7. a pattern width of at least a part of the pattern of the innermost turn of the first winding portion is narrower than a pattern width of other turns of the first winding portion; 2. The antenna device according to claim 1.

8. The coil pattern further includes a third winding portion that is located on an outer circumferential side of the first winding portion and winds without passing through the second winding portion.

2. The antenna device according to claim 1.

9. A pattern width of the third winding portion is narrower than a pattern width of at least a part of the pattern of the first winding portion.

9. The antenna device according to claim 8.

10. The coil pattern further includes a fourth winding portion that is located on the inner circumferential side of the first winding portion and winds without passing through the second winding portion.

2. The antenna device according to claim 1.

11. A pattern width of the fourth winding portion is narrower than a pattern width of at least a part of the pattern of the first winding portion. The antenna device according to claim 10.

12. A space width between the turns of the fourth winding portion is wider than a space width between the turns of the first winding portion. The antenna device according to claim 10.

13. A capacitor electrode pattern connected to an inner peripheral end of the coil pattern is further provided. The capacitor electrode pattern includes a plurality of linear patterns extending parallel to each other.

2. The antenna device according to claim 1.

14. Between the capacitor electrode pattern and the magnetic body, no other conductor pattern is provided that faces the capacitor electrode pattern via an insulating material.

14. An antenna device according to claim 13.

15. a space width between a first section including an outer circumferential end of the coil pattern and a second section adjacent to the first section is larger than a space width between the second section and a third section adjacent to the second section; 2. The antenna device according to claim 1.

16. An adhesive layer is further provided to adhere the magnetic body and the coil pattern, the coil pattern has a seed portion made of a colored conductive resin material and a main body portion made of a metal located on the seed portion, the seed layer is exposed from a surface of the adhesion layer; The main body portion is embedded in the adhesive layer without being exposed from the surface of the adhesive layer.

2. The antenna device according to claim 1.

17. An antenna device according to any one of claims 1 to 16, an IC module overlapping the second winding portion of the coil pattern via the through hole of the magnetic body; An IC card comprising:

18. Further, a metal plate is provided which covers the magnetic body from the side opposite to the coil pattern. the metal plate has a through hole in which the IC module is placed; 18. An IC card according to claim 17.

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