Antenna device and IC card provided with same

Abstract

In the antenna device capable of being used for the IC card, a through hole formed in a metal plate is miniaturized. An antenna device (1) is provided with: a metal plate having a first through-hole (43); a first coil pattern (110) having an opening (110a) overlapping the first through-hole (43) and surrounding the first through-hole (43); and a second coil pattern (120) connected to the first coil pattern (110) and surrounding the outer edge (49) of the metal plate (40). The first through-hole (43) has a first edge (431) located in the + Y direction when viewed from the center of the first through-hole (43), and a second edge (432) located in the-Y direction when viewed from the center of the first through-hole (43). The first and second edges (431, 432) respectively have first and second protruding parts (431A, 432A) that protrude toward the center of the first through hole (43) and that have tips overlapping a winding region of the first coil pattern (110).

Description

Technical Field

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

[0002] Patent Document 1 discloses an IC card having a metal plate provided with a through hole and an IC module housed in the through hole.

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: US Patent Application Publication No. 2018 / 0341846 Summary of the Invention

[0006] Technical Problem to be Solved by the Invention

[0007] However, in the IC card described in Patent Document 1, since the IC module is mounted on the stepped portion of the metal plate provided around the through hole, there is a problem that the communication performance is degraded due to the influence of the stepped portion.

[0008] In the present disclosure, a technique for suppressing a decrease in communication performance caused by a metal plate in an antenna device applicable to an IC card will be described.

[0009] Means for Solving the Technical Problem

[0010] An antenna device according to an embodiment of the present disclosure includes: a metal plate having a first through hole; a coil including a first coil having an opening overlapping the first through hole and wound around the first through hole, and a second coil connected to the first coil and wound around the outer edge of the metal plate, the edge of the first through hole having a first edge on one side in a first direction when viewed from the center of the first through hole and a second edge on the other side in the first direction when viewed from the center of the first through hole, the first edge having a first protrusion that protrudes toward the second edge and has a portion overlapping the winding region of the first coil, and the second edge having a second protrusion that protrudes toward the first edge and has a portion overlapping the winding region of the first coil.

[0011] Advantageous Effects of the Invention

[0012] According to the present disclosure, a technique for suppressing a decrease in communication performance caused by a metal plate in an antenna device applicable to an IC card can be provided. Brief Description of the Drawings

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

[0014] Figure 2 It is a schematic exploded perspective view for explaining the structure of the IC card 3 equipped with the antenna device 1.

[0015] Figure 3 It is a schematic cross-sectional view for explaining the structure of the IC card 3 equipped with the antenna device 1.

[0016] Figure 4 It is a schematic top view for explaining the shape of the metal plate 40.

[0017] Figure 5 It is a schematic top view of the conductor pattern formed on one surface 21 of the base material 20.

[0018] Figure 6 It is a schematic top view of the conductor pattern formed on the other surface 22 of the base material 20.

[0019] Figure 7 It is an equivalent circuit diagram of the antenna device 1.

[0020] Figure 8 It is an equivalent circuit diagram of the antenna device of the modified example.

[0021] Figure 9 It is a schematic top view showing the state where the base material 20, the magnetic body 30, and the metal plate 40 are overlapped.

[0022] Figure 10 It is a schematic perspective view of observing the IC module 70 from the back side.

[0023] Figure 11 It is a schematic diagram showing the state where the IC card 3 and the card reader 6 communicate.

[0024] Figure 12 It is a schematic top view for explaining the shape of the metal plate 40 of the first modified example.

[0025] Figure 13 It is a schematic top view for explaining the shape of the metal plate 40 of the second modified example.

[0026] Figure 14 It is a schematic top view for explaining the shape of the metal plate 40 of the third modified example.

[0027] Symbol Explanation

[0028] 1... Antenna device

[0029] 3... IC card

[0030] 3a... Upper surface of the IC card

[0031] 3b... Back side of the IC card

[0032] 6……Card reader

[0033] 10……Plastic plate

[0034] 20……Base material

[0035] 21、22……Surfaces of the base material

[0036] 22……Surface

[0037] 30……Magnetic body

[0038] 31……Second through-hole

[0039] 40……Metal plate

[0040] 41、42……Surfaces of the metal plate

[0041] 43……First through-hole

[0042] 45~48……Corner parts

[0043] 49……Outer edge of the metal plate

[0044] 50……Protective sheet

[0045] 51……Third through-hole

[0046] 61~64……Adhesive layer

[0047] 70……IC module

[0048] 71……Module substrate

[0049] 72……IC chip

[0050] 73……Coupling coil

[0051] 74……Protective resin

[0052] 75……Hot melt tape

[0053] 110……First coil pattern

[0054] 110a……Opening of the first coil pattern

[0055] 111……Inner periphery of the first coil pattern

[0056] 112……Outer periphery of the first coil pattern

[0057] 120……Second coil pattern

[0058] 120a……Opening of the second coil pattern

[0059] 121……Inner periphery of the second coil pattern

[0060] 122... The outer peripheral edge of the second coil pattern

[0061] 131 - 134... Capacitor patterns

[0062] 141, 142... Connection patterns

[0063] 151 - 155... Through - hole conductors

[0064] 431 - 434... The edges of the first through - holes

[0065] 431A - 434A... Protrusions

[0066] C... Capacitor

[0067] E... Terminal electrode Detailed implementation mode

[0068] Next, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0069] Figure 1 is a schematic perspective view showing the appearance of the IC card 3 equipped with the antenna device according to an embodiment of the present disclosure.

[0070] As Figure 1 shown, the IC card 3 of the present 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 that constitute the XY plane. An IC module described later is built in the IC card 3, and the terminal electrode E of the IC module is exposed on the upper surface 3a of the IC card 3.

[0071] Figure 2 and Figure 3 are respectively a schematic exploded perspective view and a schematic cross - sectional view for explaining the structure of the IC card 3 equipped with the antenna device 1 according to the present embodiment.

[0072] Figure 2 and Figure 3The IC card 3 shown has a structure in which a plastic plate 10, a coil including a film-like base material 20 and a first coil pattern 110 and a second coil pattern 120 supported thereon, a magnetic body 30, a metal plate 40, and a protective sheet 50 are laminated in this order from the back surface 3b side toward the upper surface 3a side. The antenna device 1 of the present embodiment is composed of the first coil pattern 110, the second coil pattern 120, and the metal plate 40. The plastic plate 10, the base material 20, and the first coil pattern 110 and the second coil pattern 120 supported on the base material 20 are bonded via an adhesive layer 61. The base material 20 and the magnetic body 30 are bonded via an adhesive layer 62. The magnetic body 30 and the metal plate 40 are bonded via an adhesive layer 63. The metal plate 40 and the protective sheet 50 are bonded via an adhesive layer 64. Examples of the materials for the adhesive layers 61 to 64 include acrylic double-sided tapes, thermosetting resins, and thermoplastic resins.

[0073] 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.

[0074] The base material 20 is a film made of an insulating resin material, and conductor patterns are formed on one surface and the other surfaces 21 and 22 thereof. The conductor pattern provided on the surface 21 of the base material 20 includes the first coil pattern 110 and the second coil pattern 120. Examples of the conductive material constituting the conductor pattern include copper, aluminum, or their alloys. Examples of the insulating resin material constituting the base material 20 include PET (polyethylene terephthalate) or PI (polyimide). In Figure 3 the example shown, the surface 21 of the base material 20 faces the plastic plate 10 side, and the surface 22 of the base material 20 faces the magnetic body 30 and the metal plate 40 side, but the front and back of the base material 20 may be reversed.

[0075] The magnetic body 30 is made of a high magnetic permeability material. The magnetic body 30 may be a sheet-like member or a member coated on the surface 22 of the base material 20. In the case where the magnetic body 30 is a sheet-like member, as Figure 3 shown, the magnetic body 30 and the base material 20 are bonded to each other via the adhesive layer 62. In the case where the magnetic body 30 is a member coated on the surface 22 of the base material 20, the magnetic body 30 and the base material 20 are in direct contact without passing through the adhesive layer. A second through-hole 31 is provided in the magnetic body 30.

[0076] The metal plate 40 is made of a metal material such as stainless steel or titanium. On one surface 41 side of the metal plate 40, a plastic plate 10, a base material 20, a first coil pattern 110 and a second coil pattern 120 formed on its surface, and a magnetic body 30 are arranged. On the other surface 42 side of the metal plate 40, a protective sheet 50 and an IC module 70 are arranged. In the metal plate 40, a first through hole 43 is provided at a position overlapping with the second through hole 31 of the magnetic body 30. The entire first through hole 43 may also overlap with the second through hole 31. In this way, the IC card 3 is a card that uses the metal plate 40 in a part of the main body.

[0077] The protective sheet 50 is made of a material such as resin, and its outer surface constitutes the upper surface 3a of the IC card 3. In the protective sheet 50, a third through hole 51 is provided at a position overlapping with the first through hole 43 of the metal plate 40. The entire first through hole 43 may also overlap with the third through hole 51. The IC module 70 is arranged inside the third through hole 51. A part of the IC module 70 overlaps with the metal plate 40, and the remaining part of the IC module 70 overlaps with the first through hole 43 of the metal plate 40. Thus, the IC module 70 and the first coil pattern 110 face each other via the first through hole 43. The surfaces 41 and 42 of the metal plate 40 may also be flat. For example, the area of the surface 42 of the metal plate 40 that overlaps with the IC module 70 and the area that does not overlap with the IC module 70 form the same plane. That is, no step or the like is provided between the area of the surface 42 of the metal plate 40 that overlaps with the IC module 70 and the area that does not overlap with the IC module 70. Therefore, in the production of the metal plate 40, no complex processing is required.

[0078] Figure 4 It is a schematic top view for explaining the shape of the metal plate 40.

[0079] As Figure 4 shown, the first through hole 43 provided in the metal plate 40 has: a first edge 431 located in the +Y direction (one side of the Y direction) when viewed from the center of the first through hole 43, a second edge 432 located on the opposite side of the +Y direction, that is, the -Y direction (the other side in the Y direction) when viewed from the center of the first through hole 43, a third edge 433 located in the +X direction (one side of the X direction) intersecting with the +Y direction when viewed from the center of the first through hole 43, and a fourth edge 434 located on the opposite side of the +X direction, that is, the -X direction (the other side in the X direction) when viewed from the center of the first through hole 43.

[0080] The first edge 431 is not straight in the X direction and has a first protrusion 431A that protrudes in the -Y direction toward the center of the first through-hole 43 or the second edge 432. The front end of the first protrusion 431A extends in the X direction. The second edge 432 is not straight in the X direction and has a second protrusion 432A that protrudes in the +Y direction toward the center of the first through-hole 43 or the first edge 431. The front end of the second protrusion 432A extends in the X direction. The third edge 433 is not straight in the Y direction and has a third protrusion 433A that protrudes in the -X direction toward the center of the first through-hole 43 or the fourth edge 434. The front end of the third protrusion 433A extends in the Y direction. The fourth edge 434 is not straight in the Y direction and has a fourth protrusion 434A that protrudes in the +X direction toward the center of the first through-hole 43 or the third edge 433. The front end of the fourth protrusion 434A extends in the Y direction.

[0081] No first protrusion 431A and third protrusion 433A are provided at the corner 45 formed by the first edge 431 and the third edge 433. No first protrusion 431A and fourth protrusion 434A are provided at the corner 46 formed by the first edge 431 and the fourth edge 434. No second protrusion 432A and third protrusion 433A are provided at the corner 47 formed by the second edge 432 and the third edge 433. No second protrusion 432A and fourth protrusion 434A are provided at the corner 48 formed by the second edge 432 and the fourth edge 434.

[0082] As a result, the width W2 of the first through-hole 43 in the Y direction is reduced at the portions where the first protrusion 431A and the second protrusion 432A exist, and the width W1 of the first through-hole 43 in the X direction is reduced at the portions where the third protrusion 433A and the fourth protrusion 434A exist. In Figure 4 the example shown, the distance in the Y direction, i.e., the width W2, between the first protrusion 431A and the second protrusion 432A is larger than the distance in the X direction, i.e., the width W1, between the third protrusion 433A and the fourth protrusion 434A. In addition, it is assumed that the planar shape of the first through-hole 43 when the first protrusion 431A to the fourth protrusion 434A do not exist is substantially rectangular.

[0083] In Figure 4In the figure, the position of the IC module 70 is indicated by a dashed line. A part of the IC module 70 overlaps with the first protrusion 431A to the fourth protrusion 434A when viewed from above in the Z direction. That is, in the present embodiment, the planar dimension of the first through-hole 43 is smaller than that of the IC module 70. Accordingly, the IC module 70 is not inserted into the first through-hole 43, but is supported on the surface 42 side of the metal plate 40 by the first protrusion 431A to the fourth protrusion 434A. The corner portion of the IC module 70 overlaps with the corner portions 45 to 48 of the first through-hole 43.

[0084] In Figure 4 the example shown, the widths of the first protrusion 431A and the second protrusion 432A in the X direction exceed 1 / 2 of the widths of the first edge 431 and the second edge 432 in the X direction. Similarly, in Figure 4 the example shown, the widths of the third protrusion 433A and the fourth protrusion 434A in the Y direction exceed 1 / 2 of the widths of the third edge 433 and the fourth edge 434 in the Y direction. Accordingly, the IC module 70 can be stably supported by the surface 42 of the metal plate 40.

[0085] In addition, in Figure 4 the example shown, the protruding amounts of the first protrusion 431A and the second protrusion 432A are larger than the protruding amounts of the third protrusion 433A and the fourth protrusion 434A. Accordingly, the IC module 70 with the Y direction as the long side direction can be supported more stably.

[0086] The first protrusion 431A is disposed substantially at the center in the X direction of the first edge 431, and the position of its front end in the Y direction does not overlap with the third protrusion 433A and the fourth protrusion 434A. The second protrusion 432A is disposed substantially at the center in the X direction of the second edge 432, and the position of its front end in the Y direction does not overlap with the third protrusion 433A and the fourth protrusion 434A. The third protrusion 433A is disposed substantially at the center in the Y direction of the third edge 433, and the position of its front end in the X direction does not overlap with the first protrusion 431A and the second protrusion 432A. The fourth protrusion 434A is disposed substantially at the center in the Y direction of the fourth edge 434, and the position of its front end in the X direction does not overlap with the first protrusion 431A and the second protrusion 432A.

[0087] Accordingly, in the case of a hypothetical quadrilateral along the front ends of the first protrusion 431A, the second protrusion 432A, the third protrusion 433A, and the fourth protrusion 434A, the corner portions are located at the corner portions 45 to 48 of the first through-hole 43 where there are no protrusions 431A to 434A. In Figure 4In the example shown, the planar shape of the first through-hole 43 is point-symmetrical with respect to the center of the first through-hole 43. Accordingly, the IC module 70 can be stably supported by the first protrusion 431A to the fourth protrusion 434A. In addition, in Figure 4 In the example shown, the corner portions at the front ends of the first protrusion 431A to the fourth protrusion 434A have a rounded shape. Accordingly, the electric field concentration at the corner portions at the front ends of the first protrusion 431A to the fourth protrusion 434A can be suppressed, and damage to the IC module 70 caused by sharp corner portions can be prevented.

[0088] In Figure 4 In the example shown, the first protrusion 431A to the fourth protrusion 434A are provided on the first edge 431 to the fourth edge 434, respectively, but it is not necessary to provide protrusions on all the edges, and some of the protrusions can also be omitted. For example, the third protrusion 433A and the fourth protrusion 434A can be omitted, and only the first protrusion 431A and the second protrusion 432A can be provided. In this case, the third edge 433 and the fourth edge 434 extend substantially linearly in the Y direction.

[0089] Figure 5 It is a schematic plan view of a conductor pattern formed on one surface 21 of the base material 20.

[0090] In Figure 5 In the example shown, a first coil pattern 110, a second coil pattern 120, and capacitor patterns 131 and 133 are provided on one surface 21 of the base material 20. In Figure 5 In it, the position of the second through-hole 31 provided on the magnetic body 30 is indicated by a dotted line. The first coil pattern 110 is arranged at a position overlapping the second through-hole 31 of the magnetic body 30. In Figure 5 In the example shown, the number of turns of the first coil pattern 110 is about 9 turns. The width of the first coil pattern 110 in the X direction is W6, and the width of the first coil pattern 110 in the Y direction is W7. The width W6 is smaller than the width W4 of the second through-hole 31 in the X direction. The width W7 is smaller than the width W5 of the second through-hole 31 in the Y direction. In Figure 5 In the example shown, the entire first coil pattern 110 overlaps the second through-hole 31 of the magnetic body 30.

[0091] The second coil pattern 120 is a pattern that surrounds the outer edge of the base material 20 for about 3 turns, and the first coil pattern 110 and the capacitor patterns 131 and 133 are arranged in the opening 120a surrounded by the second coil pattern 120. Since the outer shape of the base material 20 is substantially the same as the outer shape of the metal plate 40, when the base material 20 and the metal plate 40 are overlapped, in a plan view, the second coil pattern 120 surrounds the outer edge 49 of the metal plate 40.

[0092] The capacitor pattern 131 is a pattern branched in the X direction from the innermost turn of the second coil pattern 120. In Figure 5 the example shown, seven capacitor patterns 131 are branched from the innermost turn of the second coil pattern 120, but the number of capacitor patterns 131 is not particularly limited. In addition, a plurality of capacitor patterns 133 are branched from one capacitor pattern 131. The capacitor patterns 133 all extend in the Y direction. In Figure 5 the example shown, twelve capacitor patterns 133 are branched from one capacitor pattern 131, but the number of capacitor patterns 133 is not particularly limited.

[0093] Figure 6 is a schematic plan view of a conductor pattern formed on the other surface 22 of the substrate 20, showing a state observed through the substrate 20 from the one surface 21 side.

[0094] As Figure 6 shown, capacitor patterns 132, 134 and connection patterns 141, 142 are arranged on the other surface 22 of the substrate 20. The planar positions of the capacitor patterns 132, 134 coincide with those of the capacitor patterns 131, 133 respectively. That is, the capacitor patterns 131, 132 face each other via the substrate 20, and the capacitor patterns 133, 134 face each other via the substrate 20. Thus, the capacitor C is constituted by the capacitor patterns 131, 133 provided on one surface 21 of the substrate 20, the capacitor patterns 132, 134 provided on the other surface 22 of the substrate 20, and the substrate 20 located therebetween. The capacitance of the capacitor C having such a pattern shape can be finely adjusted by trimming and removing several capacitor patterns 133.

[0095] As Figure 5 and Figure 6 shown, the outer peripheral ends of the second coil pattern 120 are connected to the capacitor patterns 132, 134 via through-hole conductors 151 provided through the substrate 20. In addition, a part of the second turn (the second turn counted from the innermost turn) among the turns constituting the second coil pattern 120 is cut off. One end and the other end of the cut-off part are connected to through-hole conductors 152, 153 provided through the substrate 20 respectively. The through-hole conductor 152 is connected to one end of the connection pattern 141, and the through-hole conductor 153 is connected to one end of the connection pattern 142. The other ends of the connection patterns 141, 142 are connected to through-hole conductors 154, 155 provided through the substrate 20 respectively. The through-hole conductors 154, 155 are connected to the inner peripheral end and the outer peripheral end of the first coil pattern 110 respectively.

[0096] According to this structure, the first coil pattern 110 and the second coil pattern 120 are connected in series, and as Figure 7As shown, the capacitor C is connected in series with respect to the first and second coil patterns 110 and 120. The resonant circuit composed of the first and second coil patterns 110 and 120 and the capacitor C forms a closed circuit not connected to an external circuit. The capacitor C functions to improve communication performance by adjusting the resonant frequency. Moreover, by setting the resonant frequency of this closed circuit to 13.56 MHz or a frequency band around 13.56 MHz, short-range wireless communication (NFC) can be performed. Or, as Figure 8 shown, the capacitor C may also be connected in parallel with respect to the first and second coil patterns 110 and 120. In this case, by designing the line length of the first coil pattern 110 to be longer than the line length of the second coil pattern 120, the same resonant characteristics as those in the case where the capacitor C is connected in series with respect to the first and second coil patterns 110 and 120 can be obtained.

[0097] Figure 9 is a schematic top view showing a state in which the base material 20, the magnetic body 30, and the metal plate 40 are overlapped.

[0098] As Figure 9 shown, when the base material 20, the magnetic body 30, and the metal plate 40 are overlapped, the first coil pattern 110 provided on the base material 20, the second through-hole 31 of the magnetic body 30, and the first through-hole 43 of the metal plate 40 are overlapped in the Z direction. The opening 110a surrounded by the first coil pattern 110 also overlaps with the second through-hole 31 and the first through-hole 43. The width of the opening 110a in the X direction is W8, and the width of the opening 110a in the Y direction is W9. The width W8 is smaller than the widths W1 and W4 (refer to Figure 4 , Figure 5 ), and the width W9 is smaller than the widths W2 and W5 (refer to Figure 4 , Figure 5 ). That is, the area of the opening 110a is smaller than the areas of the through-holes 31 and 43. The opening 110a of the first coil pattern 110 may also entirely overlap with the through-holes 31 and 43. Accordingly, interference between the magnetic flux passing through the opening 110a of the first coil pattern 110 and the magnetic body 30 and the metal plate 40 can be prevented.

[0099] The width W6 (refer to Figure 5 ) of the first coil pattern 110 in the X direction is larger than the width W1 (refer to Figure 4 ) of the first through-hole 43 of the metal plate 40 in the X direction. The width W7 (refer to Figure 5 ) of the first coil pattern 110 in the Y direction is larger than the width W2 (refer to Figure 4)。Thus, when the base material 20 and the metal plate 40 are overlapped, the front ends of the first protruding portions 431A to the fourth protruding portions 434A of the first through-hole 43 overlap with the winding region of the first coil pattern 110. The winding region of the first coil pattern 110 is the region between the inner peripheral edge 111 and the outer peripheral edge 112 of the first coil pattern 110. As a result, there are portions of the first coil pattern 110 that overlap with the metal plate 40 and portions that overlap with the first through-hole 43 instead of overlapping with the metal plate 40. The outer peripheral edge 112 of the first coil pattern 110 has a portion located between the edge of the second through-hole 31 of the magnetic body 30 and the edge of the first through-hole 43 of the metal plate 40. In addition, the winding region of the second coil pattern 120 is the region between the inner peripheral edge 121 and the outer peripheral edge 122 of the second coil pattern 120.

[0100] In Figure 9 the example shown, the front ends of the first protruding portions 431A to the fourth protruding portions 434A are located at positions outside the center in the radial direction of the winding region of the first coil pattern 110. Accordingly, since the overlapping area of the winding region of the first coil pattern 110 and the metal plate 40 is reduced, more magnetic flux can pass through the first through-hole 43. In addition, since the magnetic flux density directly above and directly below the winding region of the first coil pattern 110 is lower than that near the opening 110a or the outer peripheral edge 112, by arranging the edges 431 to 434 of the first through-hole 43 in this region, deterioration of the antenna characteristics caused by the reverse magnetic field can be suppressed.

[0101] In Figure 9 the example shown, since the protruding amounts of the first and second protruding portions 431A and 432A are larger than those of the third and fourth protruding portions 433A and 434A, the front ends of the first and second protruding portions 431A and 432A are located closer to the center side in the radial direction of the winding region of the first coil pattern 110 than the front ends of the third and fourth protruding portions 433A and 434A.

[0102] Figure 10 is a schematic perspective view of the IC module 70 viewed from the back side.

[0103] As Figure 10 shown, the IC module 70 includes a module substrate 71, an IC chip 72 mounted on or built in the module substrate 71, and a coupling coil 73. The IC chip 72 is protected by being covered with a dome-shaped protective resin 74. The protective resin 74 is composed of an insulating member. When the IC module 70 is arranged on the surface 42 of the metal plate 40, as Figure 3 shown, the coupling coil 73 and the adhesive layer 64 are bonded via a heat-melt tape 75. In this state, a part of the protective resin 74 may also be arranged in the first through-hole 43 of the metal plate 40. On the back side of the module substrate 71,Figure 1 The terminal electrode E shown. The IC module 70 having such a structure can be arranged on the other surface 42 side of the metal plate 40. As described above, a part of the protective resin 74 can also be arranged in the first through hole 43 of the metal plate 40, but the module substrate 71 itself is not arranged in the first through hole 43 of the metal plate 40. Thus, the size of the first through hole 43 of the metal plate 40 can be made smaller than the size of the module substrate 71.

[0104] When the IC module 70 is arranged on the other surface 42 side of the metal plate 40, the coupling coil 73 and the first coil pattern 110 provided on the base material 20 are electromagnetically coupled through the first through hole 43 of the metal plate 40. The planar position of the winding area of the coupling coil 73 can also be substantially the same as the planar position of the winding area of the first coil pattern 110. In this case, the front ends of the first protrusion 431A to the fourth protrusion 434A of the first through hole 43 of the metal plate 40 overlap the winding area of the coupling coil 73. Moreover, since the first coil pattern 110 and the second coil pattern 120 are connected in series, when current flows through the first coil pattern 110, current also flows through the second coil pattern 120, and a magnetic field is generated from the second coil pattern 120. Thus, as Figure 11 shown, when the back surface 3b of the IC card 3 faces the card reader 6, communication can be performed between the card reader 6 and the IC chip 72.

[0105] In the present embodiment, the number of turns of the first coil pattern 110 is about 9 turns, the number of turns of the second coil pattern 120 is about 3 turns, and the number of turns of the first coil pattern 110 is more than that of the second coil pattern 120. Thus, the coupling between the first coil pattern 110 and the coupling coil 73 of the IC module 70 can be improved. On the other hand, for the second coil pattern 120, since the number of turns is less than that of the first coil pattern 110 and the pattern width is larger than the pattern width of the first coil pattern 110, the resistance value of the second coil pattern 120 is reduced.

[0106] Thus, the antenna device 1 of the present embodiment includes a metal plate 40 having a first through hole 43, and a first coil pattern 110 is arranged such that the opening 110a overlaps with the first through hole 43 and surrounds the first through hole 43. Therefore, the IC module 70 disposed on the other surface 42 of the metal plate 40 and the first coil pattern 110 disposed on one surface 41 of the metal plate 40 can be coupled. Moreover, since the first edge 431 to the fourth edge 434 of the first through hole 43 respectively have first protrusions 431A to 434A, the IC module 70 having a planar size larger than that of the first through hole 43 can be supported on the surface 42 of the metal plate 40 by the first protrusions 431A to 434A. In addition, since the planar size of the first through hole 43 is smaller than the planar size of the IC module 70, the strength of the metal plate 40 can also be improved. In addition, since the corner portions of the IC module 70 overlap with the corner portions 45 to 48 of the first through hole 43 and the metal plate 40 does not support the entire periphery of the IC module 70, the area of the metal plate 40 covering the coupling region between the coupling coil 73 of the IC module 70 and the first coil pattern 110 of the antenna device 1 is reduced. Therefore, a decrease in the coupling between the coupling coil 73 of the IC module 70 and the first coil pattern 110 of the antenna device 1 can be suppressed. Thus, since the first edge 431 to the fourth edge 434 of the first through hole 43 respectively have first protrusions 431A to 434A, a decrease in communication performance caused by the metal plate 40 can be suppressed.

[0107] Figure 12 It is a schematic top view for explaining the shape of the metal plate 40 of the first modification.

[0108] Figure 12 The shown metal plate 40 and Figure 4 The difference between the shown metal plate 40 and the metal plate 40 shown is that the width of the first protrusion 431A and the second protrusion 432A in the X direction is about 1 / 2 of the width of the first edge 431 and the second edge 432 in the X direction, and the width of the third protrusion 433A and the fourth protrusion 434A in the Y direction is about 1 / 2 of the width of the third edge 433 and the fourth edge 434 in the Y direction. Thus, if the widths of the first protrusions 431A to 434A are reduced, the area of the first through hole 43 is enlarged. Therefore, more magnetic flux can pass through the first through hole 43.

[0109] Figure 13 It is a schematic top view for explaining the shape of the metal plate 40 of the second modification.

[0110] Figure 13 In the shown metal plate 40, the first protrusions 431A to 434A are all divided into a plurality of parts, which is different from Figure 4The metal plate 40 shown is different. In this way, a plurality of first protruding portions 431A to fourth protruding portions 434A can also be provided on the first edge 431 to the fourth edge 434 respectively. Accordingly, the IC module 70 can be stably supported, and more magnetic flux can pass through the first through hole 43.

[0111] Figure 14 It is a schematic top view for explaining the shape of the metal plate 40 of the third modification.

[0112] Figure 14 In the metal plate 40 shown, the first protruding portion 431A has a first connecting portion 81 and a first wide portion 91, the second protruding portion 432A has a second connecting portion 82 and a second wide portion 92, the third protruding portion 433A has a third connecting portion 83 and a third wide portion 93, and the fourth protruding portion 434A has a fourth connecting portion 84 and a fourth wide portion 94, which is different from the metal plate 40 shown in Figure 4 The metal plate 40 shown. The first connecting portion 81 to the fourth connecting portion 84 are portions connected to the main body portion of the metal plate 40. The first wide portion 91 to the fourth wide portion 94 are portions located closer to the center side of the first through hole 43 than the first connecting portion 81 to the fourth connecting portion 84. That is, the first wide portion 91 is located on the -Y direction side with respect to the first connecting portion 81, the second wide portion 92 is located on the +Y direction side with respect to the second connecting portion 82, the third wide portion 93 is located on the -X direction side with respect to the third connecting portion 83, and the fourth wide portion 94 is located on the +X direction side with respect to the fourth connecting portion 84. In the example shown in Figure 14 The metal plate 40 shown, the first wide portion 91 to the fourth wide portion 94 respectively constitute the front ends of the first edge 431 to the fourth edge 434. Moreover, the width in the X direction of the first wide portion 91 and the second wide portion 92 is larger than the width in the X direction of the first connecting portion 81 and the second connecting portion 82. Similarly, the width in the Y direction of the third wide portion 93 and the fourth wide portion 94 is larger than the width in the Y direction of the third connecting portion 83 and the fourth connecting portion 84.

[0113] When using the metal plate 40 having such a shape, the planar position of the outer peripheral edge of the first coil pattern 110 or the coupling coil 73 can be configured to overlap with the space between the first wide portion 91 to the fourth wide portion 94 and the main body portion of the metal plate 40. Accordingly, since most of the outer peripheral edge of the first coil pattern 110 or the coupling coil 73 does not overlap with the metal plate 40 but overlaps with the first through hole 43, more magnetic flux can pass through the first through hole 43.

[0114] Above, the embodiments of the present disclosure have been described, but the present disclosure is not limited to the above embodiments, and various changes can be made without departing from the gist of the present disclosure, and these changes are of course included in the scope of the present disclosure.

[0115] For example, the conductor patterns provided on the surfaces 21 and 22 of the base material 20 may also be provided on the surfaces 21 and 22 of the base material 20 via other material layers containing resin therebetween. In addition, the coil may also be a coil formed by winding a wire.

[0116] In addition, the first coil pattern 110 and the second coil pattern 120 constituting the coil are not limited to Figure 5 the pattern shapes shown. For example, it may also be a pattern in which each turn of the second coil pattern 120 protrudes toward the opening 120a, and the protruding portion surrounds in a direction opposite to that of the second coil pattern 120 as the first coil pattern 110. In this case, the first coil pattern 110 and the second coil pattern 120 can be formed only on one surface of the base material 20.

[0117] The technology of the present disclosure includes the following structural examples, but is not limited thereto.

[0118] An antenna device provided by an embodiment of the present disclosure includes: a metal plate having a first through hole; and a coil including a first coil whose opening overlaps with the first through hole and which surrounds the first through hole, and a second coil connected to the first coil and surrounding the outer edge of the metal plate. The edge of the first through hole has a first edge on one side in a first direction when viewed from the center of the first through hole, and a second edge on the other side in the first direction when viewed from the center of the first through hole. The first edge has a first protrusion that protrudes toward the second edge and has a portion overlapping with the winding area of the first coil. The second edge has a second protrusion that protrudes toward the first edge and has a portion overlapping with the winding area of the first coil. Accordingly, an IC module or the like can be supported on the surface of the metal plate, and a decrease in communication performance caused by the metal plate can be suppressed.

[0119] In the antenna device described above, the planar shape of the first through hole may be point-symmetrical with respect to the center of the first through hole. Accordingly, an IC module or the like can be stably supported on the surface of the metal plate.

[0120] In the antenna device described above, the tips of the first and second protrusions may also be located at positions outside the radial center of the winding area of the first coil. Accordingly, the overlapping area of the first coil and the metal plate can be reduced.

[0121] In the antenna device described above, it may also be that the first edge has a plurality of first protrusions and the second edge has a plurality of second protrusions. Accordingly, an IC module or the like can be stably supported on the surface of the metal plate, and more magnetic flux can pass through the first through hole.

[0122] In the above-described antenna device, the corners at the front ends of the first and second protrusions may also have a rounded shape. Accordingly, it is possible to suppress the electric field concentration at the corners at the front ends of the first and second protrusions.

[0123] In the above-described antenna device, it may also be that the edge of the first through-hole has a third edge located on one side in a second direction intersecting the first direction when viewed from the center of the first through-hole, and a fourth edge located on the other side in the second direction when viewed from the center of the first through-hole. The third edge has a third protrusion that protrudes toward the fourth edge and has a portion overlapping with the winding region of the first coil. The fourth edge has a fourth protrusion that protrudes toward the third edge and has a portion overlapping with the winding region of the first coil. Accordingly, it is possible to more stably support an IC module or the like on the surface of the metal plate.

[0124] In the above-described antenna device, it may also be that the first edge has a plurality of first protrusions, the second edge has a plurality of second protrusions, the third edge has a plurality of third protrusions, and the fourth edge has a plurality of fourth protrusions. Accordingly, it is possible to stably support an IC module or the like on the surface of the metal plate and allow more magnetic flux to pass through the first through-hole.

[0125] In the above-described antenna device, it may also be that the first protrusion has a first connecting portion and a first wide portion located on the other side in the first direction relative to the first connecting portion, the second protrusion has a second connecting portion and a second wide portion located on the side in the first direction relative to the second connecting portion, and the widths of the first and second wide portions in a second direction intersecting the first direction are larger than the widths of the first and second connecting portions in the second direction. Accordingly, it is possible to reduce the overlap between the outer edge portion of the first coil and the metal plate.

[0126] In the above-described antenna device, it may also be that the pattern width of the second coil is larger than the pattern width of the first coil, and the number of turns of the second coil is less than the number of turns of the first coil. Accordingly, it is possible to increase the magnetic flux density generated by the first coil and reduce the resistance value of the second coil.

[0127] In the above-described antenna device, it may also be that a magnetic body is further provided, the magnetic body has a second through-hole overlapping with the first through-hole, the area of the second through-hole is larger than the area of the first through-hole, and the entire first through-hole overlaps with the second through-hole. Accordingly, it is possible to eliminate the overlap between the first coil and the magnetic body.

[0128] An IC card provided by an embodiment of the present disclosure includes the antenna device according to any one of the above and an IC module overlapping with the first coil via a first through-hole. Accordingly, it is possible to provide an IC card including a metal plate.

[0129] In the above IC card, it is also possible that the IC module has a coupling coil that overlaps with the first coil when viewed from above, and the first and second protrusions overlap with the winding area of the coupling coil. Accordingly, the edge of the first through-hole of the metal plate can be disposed in a region with a low magnetic flux density.

[0130] In the above IC card, it is also possible that the first coil is disposed on one surface side of the metal plate, the IC module is disposed on the other surface side of the metal plate, the IC module has a module substrate, an IC chip mounted on the module, and a protective resin covering the IC chip, and at least a part of the protective resin is located in the first through-hole. Accordingly, the IC module can be coupled to the first coil without disposing the module substrate in the first through-hole of the metal plate.

Claims

1. An antenna device, wherein: have: a metal plate having a first through hole; and The coil includes: a first coil having an opening overlapping with the first through hole and surrounding along the first through hole, and a second coil connected to the first coil and surrounding along the outer edge of the metal plate, The edge of the first through hole has a first edge located on one side in a first direction when viewed from the center of the first through hole, and a second edge located on the other side in the first direction when viewed from the center of the first through hole. The first edge has a first protrusion, which protrudes toward the second edge and has a portion overlapping with a winding area of ​​the first coil. The second edge has a second protrusion that protrudes toward the first edge and has a portion that overlaps with a winding region of the first coil.

2. The antenna device according to claim 1, wherein: The planar shape of the first through hole is point-symmetrical with respect to the center of the first through hole.

3. The antenna device according to claim 1, wherein: The front ends of the first and second protruding portions are located outside the center of the winding region of the first coil in the radial direction.

4. The antenna device according to claim 1, wherein: The first edge has a plurality of the first protrusions, The second edge has a plurality of the second protrusions.

5. The antenna device according to claim 1, wherein: Corners of the front ends of the first and second protrusions have rounded shapes.

6. The antenna device according to claim 1, wherein: The edge of the first through hole has a third edge located on one side in a second direction intersecting the first direction when viewed from the center of the first through hole, and a fourth edge located on the other side in the second direction when viewed from the center of the first through hole. The third edge has a third protrusion, which protrudes toward the fourth edge and has a portion overlapping with the winding area of ​​the first coil. The fourth edge has a fourth protrusion that protrudes toward the third edge and has a portion that overlaps with a winding region of the first coil.

7. The antenna device according to claim 6, wherein: The first edge has a plurality of the first protrusions, The second edge has a plurality of the second protrusions, The third edge has a plurality of third protrusions, The fourth edge has a plurality of the fourth protrusions.

8. The antenna device according to claim 1, wherein: The first protrusion has a first connection portion and a first wide portion located on the other side of the first connection portion in the first direction. The second protrusion has a second connection portion and a second wide portion located on one side of the second connection portion in the first direction. The widths of the first and second wide portions in a second direction intersecting the first direction are larger than the widths of the first and second connecting portions in the second direction.

9. The antenna device according to claim 1, wherein: The pattern width of the second coil is larger than the pattern width of the first coil, The number of turns of the second coil is smaller than the number of turns of the first coil.

10. The antenna device according to claim 1, wherein: further comprising a magnetic body having a second through hole overlapping the first through hole, The area of ​​the second through hole is larger than the area of ​​the first through hole, The first through hole entirely overlaps with the second through hole.

11. An IC card, wherein: have: The antenna device according to any one of claims 1 to 10; and The IC module overlaps with the first coil via the first through hole.

12. The IC card according to claim 11, wherein: The IC module has a coupling coil overlapping the first coil in a plan view, The first and second protrusions overlap with a winding region of the coupling coil.

13. The IC card according to claim 11, wherein: The first coil is arranged on one surface side of the metal plate. The IC module is arranged on the other surface side of the metal plate. The IC module includes a module substrate, an IC chip mounted on the module, and a protective resin covering the IC chip. At least a portion of the protective resin is located in the first through hole.

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