Antenna device and IC card

The antenna device achieves strength and adhesion by using a conductor pattern with varying wire widths and heights, addressing visibility and durability issues in IC cards.

JP2026061934APending Publication Date: 2026-04-09TDK CORP
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Patent Information

Authority / Receiving Office
JP · JP
Patent Type
Applications
Current Assignee / Owner
Filing Date
2024-09-30
Publication Date
2026-04-09

AI Technical Summary

Technical Problem

Existing antenna devices face challenges in maintaining conductor line strength while reducing thickness and improving adhesion to other members, particularly in applications like IC cards where visibility and durability are crucial.

Method used

The antenna device incorporates a conductor pattern with wide and narrow portions in conductive wires, where the wide portions have increased height from the support, ensuring strength and adhesion, while the narrow portions maintain thinness.

Benefits of technology

This design allows for maintaining strength and adhesion of conductive wires, enabling thinner conductor lines that are less visible and more durable in IC cards.

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Abstract

The present invention provides an antenna device and an IC card that can maintain strength while reducing the thickness of conductive wires and improve the adhesion strength of conductive wires to other components. [Solution] In the antenna device 1, the conductive wires 30 and 31 have a wide section 60 in which the wire width is maximum and a narrow section 61 in which the wire width is minimum, within a predetermined range in the first extending direction in which the conductive wires 30 and 31 extend. In this way, by providing a narrow section 61 with a small wire width within a predetermined range, the conductive wires can be made thinner and visibility can be reduced. Furthermore, rather than making the entire conductive wire 30 and 31 thinner, the strength of the conductive wires 30 and 31 themselves can be increased by providing a wide section 60 with a large wire width. In addition, the wide section has a portion in which its height from the support is greater than that of the narrow section.
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Description

Technical Field

[0001] The present disclosure relates to an antenna device and an IC card.

Background Art

[0002] Conventionally, an antenna device including a mesh-shaped conductor pattern has been known (for example, Patent Document 1). This antenna device has a support and a conductor pattern formed by arranging a plurality of conductive lines in a mesh shape on the support.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Here, in the antenna device as described above, in order to suppress the visibility of the conductor pattern, it has been required to make the conductive lines thinner. On the other hand, it has also been required to ensure the strength of the conductive lines. Furthermore, when the antenna device is applied to an IC card or the like, it has been required to improve the adhesion strength of the conductive lines to other members.

[0005] Therefore, an object of the present disclosure is to provide an antenna device and an IC card that can ensure strength while making the conductive lines thinner and improve the adhesion strength of the conductive lines to other members.

Means for Solving the Problems

[0006] An antenna device relating to one aspect of the present disclosure comprises a support and a conductor pattern formed by arranging a plurality of conductive wires in a mesh-like manner on the support, wherein each conductive wire has a wide portion in which the wire width is maximum and a narrow portion in which the wire width is minimum within a predetermined range in a first extending direction in which the conductive wire extends, and the wide portion has a portion in which the height from the support is greater than that of the narrow portion.

[0007] An IC card relating to one aspect of this disclosure comprises the above-described antenna device and an IC module. [Effects of the Invention]

[0008] According to one aspect of this disclosure, it is possible to provide an antenna device and an IC card that can maintain strength while reducing the thickness of the conductive wires and improve the adhesion strength of the conductive wires to other components. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic perspective view showing the appearance of an IC card incorporating an antenna device according to one embodiment of the present disclosure. [Figure 2] This is an exploded perspective view of an IC card as seen from the bottom. [Figure 3] This is a cross-sectional view along the line III-III shown in Figure 1. [Figure 4] This is a plan view of the antenna device. [Figure 5] This is a magnified view of the area around the slit. [Figure 6] This is a magnified view of the area around the slit. [Figure 7] This is a magnified view of the area around the slit. [Figure 8] This is a magnified view of the area around the slit. [Figure 9] Figure 8 shows an overall view of the antenna pattern with slits. [Figure 10] This is a magnified cross-sectional view of the antenna device. [Figure 11] This is a plan view of the conductor pattern 14. [Figure 12] Figure 12(a) is a cross-sectional view of the wide section, and Figure 12(b) is a cross-sectional view of the narrow section. [Figure 13] This figure shows an example of an enlarged conductor pattern. [Figure 14] This is an enlarged plan view showing the shape of the conductive wires at various points in the conductor pattern. [Figure 15] The cross-sectional outlines of the conductive wires corresponding to each figure in Figure 14 are shown. [Figure 16] This is a diagram to explain how to set inflection points. [Modes for carrying out the invention]

[0010] Several embodiments of this disclosure are described in detail below. However, this disclosure is not limited to the embodiments described below.

[0011] Figure 1 is a schematic perspective view showing the external appearance of an IC card 100 incorporating an antenna device according to one embodiment of the present disclosure. The IC card 100 shown in Figure 1 is a plate-like body with the Y-axis direction as the short side, the X-axis direction as the long side, and the Z-axis direction as the thickness side, and has an upper surface a and a lower surface b that constitute the XY plane. The IC card 100 incorporates an IC module 50 and an antenna device, which will be described later, and the terminal electrodes E of the IC module are exposed on the upper surface a of the IC card 100. The IC card 100 can communicate via the antenna device by bringing it close to a card reader 110. The application examples of the IC card 100 are not particularly limited, but it may be applied to a transparent IC card that enables contactless communication in which the wires and conductor patterns constituting the antenna are not visible, for example, a transparent dual-interface card such as a bank card or credit card.

[0012] FIG. 2 is an exploded perspective view of the IC card 100 as viewed from the lower surface b side. FIG. 3 is a cross-sectional view taken along the line III-III shown in FIG. 1. FIG. 3 shows the structure near the IC module 50. As shown in FIGS. 2 and 3, the IC card 100 includes a card body 80, an antenna device 1, and an IC module 50. The card body 80 has an upper layer 5, a card base material 2, and a lower layer 3. The IC card 100 has a structure in which the upper layer 5, the card base material 2, the antenna device 1, and the lower layer 3 are laminated in this order from the upper surface a side to the lower surface b side. Further, the IC card 100 includes an IC module 50. In the present embodiment, the IC module 50 is arranged in a region on the negative side in the X-axis direction and closer to the positive side in the Y-axis direction of the IC card 100. However, the position of the IC module 50 is not particularly limited.

[0013] The card base material 2 is a plate-like member that covers the main surface 1b on the negative side in the Z-axis direction of the antenna device 1. The card base material 2 is joined to the main surface 1b on the negative side in the Z-axis direction of the antenna device 1. The upper layer 5 is joined to the main surface on the negative side in the Z-axis direction of the card base material 2 via an adhesive layer 12. The main surface on the negative side in the Z-axis direction of the upper layer 5 constitutes the upper surface a of the IC card 100. A substantially rectangular IC mounting opening 4A is provided in the upper layer 5. The IC mounting opening 4A penetrates the upper layer 5 in the thickness direction (Z-axis direction). A substantially rectangular IC mounting opening 4B is provided in the card base material 2. The IC mounting opening 4B penetrates the card base material 2 in the thickness direction (Z-axis direction). The IC module 50 is arranged inside the IC mounting openings 4A and 4B (see FIG. 3). The lower layer 3 is a plate-like member that covers the main surface 1a on the positive side in the Z-axis direction of the antenna device 1. The main surface on the negative side in the Z-axis direction of the lower layer 3 constitutes the lower surface b of the IC card 100. The card base material 2 is joined to the antenna device 1 via an adhesive layer 12. The lower layer 3 is joined to the antenna device 1 via an adhesive layer 12.

[0014] The card substrate 2, the lower layer 3, and the upper layer 5 may be transparent resin substrates. The card substrate 2, the lower layer 3, and the upper layer 5 may be composed of, for example, cellulose propionate (CP), polyvinyl chloride (PVD), polycarbonate (PC), tempered glass, etc. The thicknesses of the card substrate 2, the lower layer 3, and the upper layer 5 are not particularly limited, but may be 100 to 500 μm. The total light transmittance of the card substrate 2, the lower layer 3, and the upper layer 5 may be 90 to 100%. In the form shown in FIG. 3, the thickness of the card substrate 2 is formed to be larger than the thicknesses of the lower layer 3 and the upper layer 5.

[0015] As the adhesive layer 12, an adhesive sheet of a highly transparent thermoplastic resin or thermosetting resin may be employed. As the material of the adhesive sheet, acrylic-based, urethane-based, epoxy-based, or phenolic-based materials may be employed. The adhesive layer 12 may have no substrate, have a high total light transmittance, and have a low haze. The thickness of the adhesive layer 12 is not particularly limited, but may be 10 to 100 μm. The total light transmittance of the adhesive layer 12 may be 90 to 100%.

[0016] FIG. 4 is a plan view of the antenna device 1. As shown in FIG. 4, the antenna device 1 is a rectangular plate-like member. The antenna device 1 has an edge 1c on the negative side in the X-axis direction, an edge 1d on the positive side in the X-axis direction, an edge 1e on the negative side in the Y-axis direction, and an edge 1f on the positive side in the Y-axis direction. In the present embodiment, the edges 1c and 1d are the short sides, and the edges 1e and 1f are the long sides.

[0017] The antenna device 1 includes a mesh-like conductor pattern 14 having a plurality of mesh sections 17 (see Figure 5). The conductor pattern 14 is a mesh-like pattern that includes a plurality of regularly arranged mesh sections 17 (see Figure 5) formed by a plurality of conductive wires that intersect each other. Details of the pattern configuration of the conductor pattern 14 will be described later. The conductor pattern 14 is formed on substantially the entire surface of the main surface 1a of the antenna device 1. The conductor pattern 14 has a rectangular shape corresponding to the shape of the main surface 1a. The conductor pattern 14 has a negative edge 14c in the X-axis direction, a positive edge 14d in the X-axis direction, a negative edge 14e in the Y-axis direction, and a positive edge 14f in the Y-axis direction.

[0018] The conductor pattern 14 has an opening 20 and a slit 21 extending from the opening 20 to the edge 14c of the conductor pattern 14, which are areas where the mesh portion 17 and conductive wires (the first conductive wire and the second conductive wire described later) are not formed. The opening 20 and the slit 21 are areas of the conductor pattern 14 where conductive wires are omitted. Note that the support 13 remains without penetrating in the areas corresponding to the opening 20 and the slit 21. The opening 20 is formed at the position where the IC module 50 is placed. The opening 20 has a rectangular shape corresponding to the shape of the IC module 50. The slit 21 extends from the opening 20 to the edge 14c. The slit 21 extends from the negative side of the opening 20 in the X-axis direction to the negative edge 14c of the conductor pattern 14 in the X-axis direction. The slit 21 extends parallel to the X-axis direction with a constant width. The width of the slit 21 and the width of the opening 20 are dimensions in the direction perpendicular to the extending direction of the slit 21 and the penetrating direction of the opening 20, that is, the distance between the edges extending along the extending direction of the slit 21. The width of the slit 21 (dimension in the Y-axis direction) is smaller than the width of the opening 20 (dimension in the Y-axis direction).

[0019] As shown in Figure 3, the antenna device 1 comprises a support 13, a conductor pattern 14 (antenna pattern 19) provided on one of the first main surfaces 13a of the support 13, and the conductor pattern 14 extending in a direction along the first main surface 13a of the support 13 and having a plurality of mesh portions 17 (see Figure 5). The conductor pattern 14 has conductor portions 18 (see Figure 5) that form the mesh portions 17. Details of the characteristics of the support 13 will be described later.

[0020] In the opening 20, a through-hole is formed that penetrates the conductor pattern 14 in the Z-axis direction. Therefore, the opening 20 is a region where the conductor pattern 14 does not exist.

[0021] The conductor pattern 14 is placed on the lower layer 3 via the adhesive layer 12. In the example shown in Figure 3, the conductor pattern 14 is placed on the support 13. Within the IC card 100, the support 13 is located on the negative side in the Z-axis direction, and the conductor pattern 14 is located on the positive side in the Z-axis direction. Therefore, the layers are stacked in the order of upper layer 5, card substrate 2, support 13, conductor pattern 14, and lower layer 3, from the negative side to the positive side in the Z-axis direction.

[0022] The IC module 50 comprises a module substrate 51 and an IC chip 52 mounted or embedded therein. A coupling coil 53 is formed on the positive side of the module substrate 51 in the Z-axis direction (see also Figure 2). Terminal electrodes E, as shown in Figure 1, are provided on the surface side of the module substrate 51.

[0023] The IC module 50 is placed within the IC mounting openings 4A and 4B. The inner surfaces of the IC mounting openings 4A and 4B are positioned to surround the IC module 50 from the outer side. The IC module 50 is positioned opposite the opening 20 of the antenna device 1 at a position on the negative side in the Z-axis direction. The size of the opening 20 in the Y-axis and X-axis directions is smaller than that of the IC module 50. Also, the size of the opening 20 in the Y-axis and X-axis directions is smaller than the outer edge of the coupling coil 53 and larger than the inner edge of the coupling coil 53. Therefore, when viewed from the Z-axis direction, the four inner surfaces of the opening 20 are positioned to overlap with the four sides of the coupling coil 53. The IC mounting opening 4A of the upper layer 5 is larger than that of the module substrate 51. The IC mounting opening 4B of the card substrate 2 is smaller than that of the module substrate 51 and smaller than that of the coupling coil 53. The coupling coil 53 is joined to the stepped portion of the card substrate 2 via hot melt tape 46. Note that the IC card 100 is not limited to the structure shown in Figure 3.

[0024] Next, the function of the antenna device 1 will be explained with reference to Figure 4. A current CA flows through the coupling coil 53 (see Figure 2) of the IC module 50. In Figure 4, the current CA is assumed to flow counterclockwise. At this time, the magnetic flux B (see Figure 2) of the coupling coil 53 acts on the edge of the opening 20. As a result, a clockwise eddy current CB flows through the conductor pattern 14 near the edge of the opening 20. In this way, the conductor pattern 14 near the edge of the opening 20 functions as a coupling coil that magnetically couples with the coupling coil 53 of the IC module 50. Here, the conductor pattern 14 at the negative edge in the X-axis direction of the opening 20 is divided by the slit 21 up to the edge 14c. Therefore, the eddy current CB is divided by the slit 21, and currents CCa and CCb flow along the slit 21 in the X-axis direction. A current CCa flows through the conductor pattern 14 at the negative edge in the Y-axis direction of the slit 21, from the opening 20 toward the edge 14c. As a result, a counterclockwise current CD flows throughout the entire conductor pattern 14. A current CCb flows through the conductor pattern 14 at the positive edge of the slit 21 in the Y-axis direction, returning from the edge 14c side to the opening 20. In this way, the antenna device 1 can function as an antenna because a current flows through the entire conductor pattern 14 in the same direction as the IC module 50.

[0025] Next, the conductor pattern 14 will be described in detail with reference to Figure 5(a). Figure 5 is an enlarged view of the area near the slit 21. As shown in Figure 5(a), the conductor pattern 14 includes a plurality of first conductive wires 30 and a plurality of second conductive wires 31. The first conductive wires 30 are linear conductive portions 18 extending parallel to the X-axis direction. The plurality of first conductive wires 30 are arranged to be spaced apart from each other in the Y-axis direction. The plurality of first conductive wires 30 are arranged to be spaced apart at equal intervals. The second conductive wires 31 are linear conductive portions 18 extending parallel to the Y-axis direction. The plurality of second conductive wires 31 are arranged to be spaced apart from each other in the X-axis direction. The plurality of second conductive wires 31 are arranged to be spaced apart at equal intervals. The line width of the conductive wires 30,31 is not particularly limited, but may be set to, for example, 10 to 50 μm. Furthermore, the pitch of the conductive wires 30 and 31 is not particularly limited, but may be set to, for example, 50 to 1000 μm. The first conductive wire 30 and the second conductive wire 31 have a wire thickness greater than their wire width. The wire thickness of the conductive wires 30 and 31 is the dimension in the Z-axis direction. Therefore, the cross-sectional shape of the conductive wires 30 and 31 has a shape that extends in the Z-axis direction (see Figure 3). The wire thickness of the conductive wires 30 and 31 is not particularly limited, but may be set to, for example, 1 to 10 μm.

[0026] In this embodiment, the first conductive wire 30 is substantially parallel to the X-axis direction, which is the direction in which the slit 21 extends. The other second conductive wire 31 is substantially perpendicular to the X-axis direction, which is the direction in which it extends. Note that the first conductive wire 30 does not have to be parallel to the X-axis direction as long as it extends in the X-axis direction, and the second conductive wire 31 does not have to be parallel to the Y-axis direction as long as it extends in the Y-axis direction.

[0027] The normal mesh portions 17 other than those near the slits 21 and the openings 20 will now be described. Each mesh portion 17 is composed of a pair of adjacent first conductive wires 30 and a pair of adjacent second conductive wires 31. In this embodiment, each mesh portion 17 has a square shape. However, if the pitch of the first conductive wires 30 and the pitch of the second conductive wires 31 are different, the mesh portion 17 will be rectangular. The pitch of the mesh portion 17 in the Y-axis direction is equal to the pitch of the first conductive wires 30. The pitch of the mesh portion 17 in the X-axis direction is equal to the pitch of the second conductive wires 31. The width of the slit 21 (dimension in the Y-axis direction) may be greater than the pitch of the mesh portion 17 in the Y-axis direction. The width of the slit 21 may be greater than, equal to, or less than the pitch of the mesh portion 17 in the X-axis direction. In the mesh section 17, the first conductive wire 30 and the second conductive wire 31 only need to intersect, and do not necessarily need to be perpendicular. That is, a mesh section 17 in which the first conductive wire 30 and the second conductive wire 31 intersect at an angle may be used.

[0028] In the example shown in Figure 5(a), first conductive wires 30 extending in the X-axis direction are formed at both ends of the slit 21 in the Y-axis direction. Thus, a slit 21 with a border is formed. Alternatively, as shown in Figure 5(b), the ends of the slit 21 in the Y-axis direction may not have the first conductive wires 30, and the mesh portion may be open to the slit 21. In Figures 5(a) and 5(b), the slit 21 has a shape that extends in a straight line in the X-axis direction (see trajectory TL).

[0029] Furthermore, as shown in Figure 5(c), the slit 21 may be formed by extending the broken portion 40, where the second conductive wire 31 is broken, from the opening 20 to the edge 14c (see Figure 4). The method of forming the broken portion 40 is not limited; the second conductive wire 31 may originally exist, and a portion may be removed to form the broken portion 40, or the broken portion 40 may be formed by not providing a conductive wire in the area corresponding to the broken portion 40 during the stage of forming the second conductive wire 31. The state of continuous broken portions 40 means that at least two conductive wires constituting one mesh portion 17 have broken portions 40, and adjacent cells of the mesh portion 17 are connected by the broken portions 40. In this case, when viewed from the extending direction of the slit 21, there may be portions where adjacent broken portions 40 in the extending direction do not overlap. In this embodiment, the extending direction of the slit 21 is the X-axis direction. For example, the row of mesh portion 17 in which the slit 21 is formed is defined as region E1. A break portion 40 is formed in a part of each second conductive wire 31 within region E1. The second conductive wire 31A has a break portion 40a near its positive end in the Y-axis direction within region E1. The break portion 40a is formed from the first conductive wire 30 on the positive side in the Y-axis direction within region E1 to a position spaced away from the first conductive wire 30 toward the negative side in the Y-axis direction. The second conductive wire 31B adjacent to the second conductive wire 31A has a break portion 40b near its negative end in the Y-axis direction within region E1. The break portion 40b is formed from the first conductive wire 30 on the negative side in the Y-axis direction within region E1 to a position spaced away from the first conductive wire 30 toward the positive side in the Y-axis direction. When viewed from the X-axis direction, adjacent break portions 40a and 40b are arranged so as not to overlap and do not have any overlapping portions. The patterns of the broken sections 40a and 40b are repeated in the X-axis direction. As a result, the slit 21 has a shape that extends in a zigzag trajectory TL along the X-axis direction. Thus, the trajectory TL drawn in the slit 21 that passes through each broken section 40 does not extend in a straight line, but rather extends while curving.

[0030] The configuration in which the trajectory TL of the slit 21 extends while curving is not limited to the example shown in Figure 5(c), and Figures 6 to 8 may also be adopted. For example, as shown in Figure 6(a), the broken sections 40a and 40b may be positioned closer to the center of region E1 than in Figure 5(c). In this case, the broken sections 40a and 40b are positioned at a distance from the first conductive wire 30 at the edge of the slit 21.

[0031] In the example shown in Figure 5(c), the zigzag trajectory TL formed by the broken section 40 was continuously formed for each second conductive wire 31. Alternatively, as shown in Figure 6(b), the zigzag trajectory TL formed by the broken section 40 does not have to be continuous for each second conductive wire 31. The second conductive wire 31A has a broken section 40a near its positive end in the Y-axis direction in region E1. The second conductive wire 31B adjacent to the second conductive wire 31A has a broken section 40b near its positive end in the Y-axis direction within region E1. The second conductive wire 31C adjacent to the second conductive wire 31B has a broken section 40c near its negative end in the Y-axis direction within region E1. The second conductive wire 31D adjacent to the second conductive wire 31C has a broken section 40d near its negative end in the Y-axis direction within region E1. The second conductive wire 31E adjacent to the second conductive wire 31D has a break 40e near its positive end in the Y-axis direction within region E1. The trajectory TL between the break 40a and the break 40b extends in the X-axis direction on the positive side of the Y-axis direction. The trajectory TL between the break 40b and the break 40c extends in the X-axis direction, inclined toward the negative side of the Y-axis direction with respect to the X-axis direction. The trajectory TL between the break 40c and the break 40d extends in the X-axis direction on the negative side of the Y-axis direction. The trajectory TL between the break 40d and the break 40e extends in the X-axis direction, inclined toward the positive side of the Y-axis direction with respect to the X-axis direction. In this way, the breaks 40a, 40b, 40c, 40d, and 40e form a zigzag pattern in the trajectory TL, and this pattern is repeated in the X-axis direction.

[0032] An example shown in Figure 6(c) may be adopted. The second conductive wire 31A has a break 40a near the positive end in the Y-axis direction in region E1. The second conductive wire 31B adjacent to the second conductive wire 31A has a break 40b near the central position in the Y-axis direction within region E1. The second conductive wire 31C adjacent to the second conductive wire 31B has a break 40c near the negative end in the Y-axis direction within region E1. The second conductive wire 31D adjacent to the second conductive wire 31C has a break 40d near the central position in the Y-axis direction within region E1. The second conductive wire 31E adjacent to the second conductive wire 31D has a break 40e near the positive end in the Y-axis direction within region E1. The trajectory TL, which is two pitches between the break 40a and the break 40c, extends so as to be inclined toward the negative side in the Y-axis direction. The trajectory TL between the broken section 40c and the broken section 40e extends inclined toward the positive side in the Y-axis direction. In this way, the broken sections 40a, 40b, 40c, 40d, and 40e form a zigzag pattern in the trajectory TL, and this pattern is repeated in the X-axis direction. Furthermore, the zigzag pattern is inclined over a distance of two pitches. Thus, the pitch of the zigzag pattern shown in Figure 6(c) is longer than the pitch of the zigzag pattern shown in Figure 5(c).

[0033] The example shown in Figure 7(a) may also be adopted. The broken sections 40a and 40b shown in Figure 7(a) are located further towards the center than the broken sections 40a and 40b shown in Figure 6(a). When viewed from the X-axis direction, the adjacent broken sections 40a and 40b are arranged so that they do not overlap in some parts, but do overlap in others.

[0034] An example shown in Figure 7(b) may be adopted. The second conductive wire 31A has a break 40a near the positive end in the Y-axis direction in region E1. The second conductive wire 31B adjacent to the second conductive wire 31A has a break 40b near the central position in the Y-axis direction within region E1. The second conductive wire 31C adjacent to the second conductive wire 31B has a break 40c near the negative end in the Y-axis direction within region E1. The second conductive wire 31D adjacent to the second conductive wire 31C has a break 40d near the positive end in the Y-axis direction within region E1. The break 40d is located at the same position as the break 40a. The trajectory TL, which is two pitches long, between the break 40a and the break 40c extends so as to be inclined toward the negative side in the Y-axis direction. The trajectory TL for one pitch between the broken section 40c and the broken section 40d extends inclined toward the positive side in the Y-axis direction. In this way, the broken sections 40a, 40b, 40c, and 40d form a zigzag pattern in the trajectory TL, and this pattern is repeated in the X-axis direction. Furthermore, the zigzag pattern has an asymmetrical shape. That is, when the second conductive wire 31C is used as the reference axis, the pattern on the positive side of the X-axis and the pattern on the negative side of the X-axis are asymmetrical.

[0035] An example shown in Figure 7(c) may be adopted. The conductive wires 30 and 31 are inclined at 45° with respect to the X-axis and Y-axis directions. Of the rows of mesh portions 17 arranged in the X-axis direction, half of the region in the Y-axis direction is defined as region E1. The first conductive wire 30A has a break 40a near the negative end in the Y-axis direction within region E1. The second conductive wire 31B intersecting the first conductive wire 30A has a break 40b near the positive end in the Y-axis direction within region E1. The first conductive wire 30C intersecting the second conductive wire 31B has a break 40c near the negative end in the Y-axis direction within region E1. The second conductive wire 31D intersecting the first conductive wire 30C has a break 40d near the positive end in the Y-axis direction within region E1. Viewed from the X-axis direction, adjacent broken sections 40a and 40b are arranged so as not to overlap, and there are no overlapping portions between them. The patterns of broken sections 40a and 40b are repeated in the X-axis direction. As a result, the slit 21 has a shape that extends in a zigzag trajectory TL along the X-axis direction. Therefore, the trajectory TL of the slit 21 extends in a curved manner.

[0036] The example shown in Figure 8 may also be adopted. In the example shown in Figure 8, unlike the example in Figure 7(c), the slit 21 extends from the opening 20 in the direction of the arrangement of the mesh portion 17. That is, the slit 21 extends at an angle of 45° with respect to the X-axis and Y-axis directions. As shown in Figure 8(a), the slit 21 extends from the opening 20 toward the edge portion 14c at an angle toward the positive side in the Y-axis direction. The example shown in Figure 8(b) has a zigzag pattern of the disconnected portion 40, which is the same as the configuration in Figure 5(c) but at an angle of 45° with respect to the X-axis and Y-axis directions.

[0037] Next, the layer structure of the conductive wires 30 and 31 will be described with reference to Figure 10. Figure 10 shows a schematic cross-sectional shape of the conductive wires 30 and 31. Details of the cross-sectional shape of the conductive wires 30 and 31 will be described later. As shown in Figure 10(a), the conductive wires 30 and 31 have a main body portion 33, a first blackened layer 34, and a second blackened layer 36. The conductive wires 30 and 31 have a surface F1 on the side facing the support 13 and a surface F2 on the opposite side from the support 13. The surface F1 on the side facing the support 13 is placed on the first main surface 13a of the support 13.

[0038] The main body 33 may contain a metal. The main body 33 may contain at least one metal selected from copper, nickel, cobalt, palladium, silver, gold, platinum, and tin, and may contain copper. The main body 33 may further contain nonmetallic elements such as phosphorus, to the extent that appropriate conductivity is maintained.

[0039] The first blackening layer 34 is a layer provided on the surface F1 on the support 13 side. The first blackening layer 34 is provided between the main body 33 and the support 13. The second blackening layer 36 is provided on the surface F2 opposite to the support 13. The second blackening layer 36 is provided on the main body 33. The blackening layers 34 and 36 are darker than the main body 33. The thickness of the blackening layers 34 and 36 may be thinner than the thickness of the main body 33. The thickness of the main body 33 may be 1 to 10 μm. In contrast, the thickness of the blackening layers 34 and 36 may be 0.001 to 5 μm. The first blackening layer 34 may be made of a conductive resin. Specifically, the conductive resin may contain conductive particles, an organic polymer resin, and a black pigment. The conductive particles may be made of the same materials as those listed for the main body 33. The organic polymer resin may be made of materials such as polyester, acrylic, or urethane. For example, when forming conductive wires 30 and 31, a first blackened layer 34 is formed on the support 13 by screen printing. A metal body 33 is grown on this first blackened layer 34 by plating. The material of the second blackened layer 36 may be metal. The second blackened layer 36 may be a black plating layer such as a black nickel plating layer, a black chromium plating layer, or a nickel-tin alloy plating layer, or a palladium substitution layer formed on the body 33. The second blackened layer 36 may also be formed by a blackening treatment in which a part of the surface of the body 33 is replaced with a compound containing another metal. Due to the difference in materials of each blackened layer 34 and 36, the conductivity of the second blackened layer 36 may be higher than that of the first blackened layer 34.

[0040] The configuration shown in Figure 10(b) may be adopted. The conductive wires 30 and 31 shown in Figure 10(b) have metal layers 37 and 38 instead of the second blackened layer 36. The metal layers 38 and 37 are layers provided on the surface F2 opposite to the support 13. The metal layer 37 is formed on the main body 33 by plating or the like. The metal layer 38 is formed on the metal layer 37 by plating or the like. The metal layer 38 has the surface F2 of the conductive wires 30 and 31. Unlike the second blackened layer 36, the metal layers 37 and 38 are metals that do not contain black pigment. For example, gold, nickel, silver, etc. may be used as the metals of the metal layers 37 and 38. The surface side of the metal layers 37 and 38 may be gold, silver, or titanium. The metal layers 37 and 38 contain different metals from each other. For example, the metal of metal layer 38 may be gold, and the metal of metal layer 37 may be nickel. The reflectivity of the metal layers 37 and 38 may be high in the main body 33.

[0041] Furthermore, as shown in Figure 10(c), the metal layers 37 and 38 may be omitted from Figure 10(b). In this case, the main body 33 has the surface F2 of the conductive wires 30 and 31.

[0042] The method for manufacturing the antenna device 1 is not limited to the method described above. For example, an antenna pattern 19 may be formed on a separate sheet, and the antenna pattern 19 may be transferred to the support 13 via an adhesive or the like.

[0043] Next, the support 13 will be described. The support 13 has a degree of light transmittance required for the antenna device 1. The total light transmittance of the antenna device 1, in which a conductor pattern 14 having a plurality of mesh portions 17 is provided on the support 13, may be 80% or more, and specifically, the total light transmittance of the support 13 may be 90 to 100%. The haze of the support 13 may be 0 to 5%.

[0044] The support 13 may be, for example, a transparent resin film, such as polyethylene terephthalate (PET), polycarbonate (PC), polyethylene naphthalate (PEN), cycloolefin polymer (COP), or polyimide (PI) films. Alternatively, the support 13 may be a glass substrate.

[0045] The thickness of the support 13 may be 10 μm or more, 20 μm or more, or 35 μm or more, and may be 500 μm or less, 200 μm or less, or 100 μm or less.

[0046] Furthermore, the support 13 possesses the infrared absorption properties required for an IC card 100, while also having the light transmittance properties required for a transparent IC card 100. The following descriptions of the light transmittance density and total light transmittance characteristics of the support 13 describe the properties inherent in the support 13 material itself. In other words, the support 13 described below is distinct from, for example, a material on which an infrared absorbent ink is coated onto a substrate that does not possess infrared absorption properties.

[0047] Support 13 has the characteristic that the maximum light transmission density is higher in the infrared region than in the visible light region. Support 13 may have the characteristic that the light transmission density in the infrared region is higher than the light transmission density in the visible light region. However, there may be parts near the boundary between the visible light region and the infrared region where the light transmission density is locally higher in the visible light region. Support 13 may also have the characteristic that the peak of the light transmission density is located in a region above the lower limit of the wavelength range in the infrared region. The region above the lower limit of the wavelength range in the infrared region is the infrared region and the region with wavelengths longer than the infrared region. Therefore, the peak of the light transmission density may be located in the infrared region or in a region with wavelengths longer than the infrared region. In addition, there may be multiple peaks of light transmission density, some of which may be located in the infrared region. The wavelength of the visible light region is 380 to 780 nm, and the wavelength of the infrared region is 780 nm to 1 mm. Support 13 may have a region where the light transmission density in the infrared region is greater than 0.7, and may have a region where it is greater than 1. The support 13 may have a region in the visible light region where the light transmission density is less than 0.1.

[0048] The total light transmittance is the transmittance at a wavelength of 550 nm, measured using a haze meter (NDH8000) manufactured by Nippon Denshoku Industries Co., Ltd. This transmittance is the total light transmittance including diffusely transmitted light, determined using an integrating sphere. The light transmission density is the light transmission density measured using a spectrophotometer with an aperture of 8 mm, a spectral range of 400 nm to 1000 nm, and a built-in integrating light diffusion chamber.

[0049] Furthermore, the support 13 may have a light transmission density greater than 1.3 in the wavelength range of 800 nm to 950 nm, and a light transmission density greater than 1.1 in the wavelength range of 950 nm to 1000 nm. This allows the IC card 100, including the antenna device 1, to satisfy the characteristics of an IC card as defined in "ISO / IEC 7810".

[0050] The total light transmittance of the support 13 in the visible light region may be 80% or more, and may be 90% or more. There is no particular upper limit set for the total light transmittance; for example, it may be 100% or less.

[0051] The thickness of the support 13 is not particularly limited, but may be, for example, 10 μm or more, 20 μm or more, or 35 μm or more, and may be 500 μm or less, 200 μm or less, or 100 μm or less.

[0052] The material of the support 13 may be one that satisfies the above-mentioned light transmission density and total light transmittance.

[0053] Figure 11 is a plan view of the conductor pattern 14. Figure 11 is a schematic diagram showing a typical wave-shaped pattern of the conductive wires 30 and 31. The shape of the conductive wires 30 and 31 may be composed of an irregular pattern, as will be described later. As shown in Figure 11, the first conductive wire 30 has a wide section 60 in which the line width is maximum and a narrow section 61 in which the line width is minimum, within a predetermined range in the extending direction (x-axis direction, first extending direction) of the first conductive wire 30.

[0054] The edges 30a and 30b of the first conductive wire 30 in the width direction (y-axis direction) have a wave-like shape in plan view. The edges 30a and 30b have a first curved edge 63 and a second curved edge 64. The first curved edge 63 is the portion that curves outward in the width direction. The second curved edge 64 is the portion that curves inward in the width direction. The first curved edge 63 of one edge 30a and the first curved edge 63 of the other edge 30b are arranged to face each other in the width direction. In the example shown in Figure 11, the wide portion 60 is provided at the point where the distance in the width direction between the first curved edge 63 of one edge 30a and the first curved edge 63 of the other edge 30b is greatest.

[0055] The second curved edge 64 of one edge 30a and the second curved edge 64 of the other edge 30b are arranged to face each other in the width direction. In the example shown in Figure 11, the narrow section 61 is provided at the point where the distance in the width direction between the second curved edge 64 of one edge 30a and the second curved edge 64 of the other edge 30b is smallest.

[0056] In Figure 11, the peak position of the first curved edge 63 of one edge 30a and the peak position of the first curved edge 63 of the other edge 30b are opposite each other in the width direction. A wide section 60 is formed at the position where these peaks face each other. However, the positions of the peaks in the direction of extension of each edge 30a and 30b may be offset from each other. The wide section 60 is the point where the width is greatest, including this offset. The peak position of the second curved edge 64 of one edge 30a and the peak position of the second curved edge 64 of the other edge 30b are opposite each other in the width direction. A narrow section 61 is formed at the position where these peaks face each other. However, the positions of the peaks in the direction of extension of each edge 30a and 30b may be offset from each other. The narrow section 61 is the point where the width is smallest, including this offset. Furthermore, the first curved edge portion 63 of one edge portion 30a, 30b does not have to face the first curved edge portion 63 of the other edge portion, and may face a substantially straight portion that does not form a curve, or may face the second curved edge portion 64. Also, the second curved edge portion 64 of one edge portion 30a, 30b does not have to face the second curved edge portion 64 of the other edge portion, and may face a substantially straight portion that does not form a curve, or may face the first curved edge portion 63.

[0057] Here, a unit region UE is set as a predetermined range. The size of the unit region UE is set such that, when set at any position in the y-axis direction of the first conductive wire 30, the edges 30a and 30b have at least one first curved edge 63 and at least one second curved edge 64. The size of the unit region UE may be set such that the edges 30a and 30b have multiple curved edges 63 and 64. If there are multiple first curved edges 63 within the unit region UE, the widest portion 60 within the unit region UE is set for the first curved edge 63 with the largest line width. If there are multiple second curved edges 64 within the unit region UE, the narrowest portion 61 within the unit region UE is set for the second curved edge 64 with the smallest line width. The first curved edge 63 with the widest portion 60 and the second curved edge 64 with the narrowest portion 61 within the unit region UE may be adjacent to each other in the direction of extension. However, within the unit region UE, other curved edges 63 and 64 may exist between the first curved edge 63 where the wide portion 60 is set and the second curved edge 64 where the narrow portion 61 is set. The size of such a unit region UE in the extending direction (here, the size in the x-axis direction) may be set to 10 to 40 μm, depending on the average value of the line width, etc. The size of the unit region UE in the width direction (here, the size in the y-axis direction) only needs to be larger than the line width of the first conductive wire 30. Multiple such unit regions UE are set in line with respect to the first conductive wire 30 in the extending direction, as shown in Figure 11. Note that a unit region UE does not need to be set at the intersection of the first conductive wire 30 and the second conductive wire 31, as the line width cannot be defined there.

[0058] The second conductive wire 31 has a wide portion 60 in which the line width is maximum and a narrow portion 61 in which the line width is minimum, within a predetermined range in the y-axis direction (first extending direction) along which the second conductive wire 31 extends. The edges 31a and 31b of the second conductive wire 31 in the width direction (x-axis direction) have a wave-like shape in plan view. The description of the wide portion 60 and narrow portion 61 of the second conductive wire 31 is the same as that of the first conductive wire 30 described above, except that the extending direction is the y-axis direction and the width direction is the x-axis direction. Therefore, the description is omitted.

[0059] Figure 12(a) is a cross-sectional view of the wide portion 60. Figure 12(b) is a cross-sectional view of the narrow portion 61. Figure 12 is a schematic diagram showing a typical cross-sectional shape of the first conductive wire 30. The same explanation applies to the cross-sectional shape of the second conductive wire 31 as to the cross-sectional shape of the first conductive wire 30. Figure 12 shows a cross-sectional view of the first conductive wire 30 in the yz plane, that is, a cross-section perpendicular to the extension direction of the first conductive wire 30 (x-axis direction, first extension direction).

[0060] As shown in Figure 12, the first conductive wire 30 has a rising portion 70 (base) on the support 13 side and a curved portion 71 provided above the rising portion 70. The rising portion 70 is the part that rises from the support 13 side in the height direction (z-axis direction). In a cross-sectional view, the rising portion 70 is the part that extends from the support 13 side toward the positive side in the z-axis direction. The rising portion 70 shown in Figure 12 extends in a substantially straight line parallel to the z-axis direction. However, as shown in Figure 15 described later, the rising portion 70 may be inclined with respect to the z-axis direction. Also, the rising portion 70 has a shape that extends in the z-axis direction overall while bending randomly. The curved portion 71 is a part that has a dome shape that extends along the width direction (y-axis direction) while curving upwards in a cross-sectional view. The curved portion 71 shown in Figure 12 draws a smoothly curved line. However, as shown in Figure 15 described later, the curved portion 71 has a shape that curves randomly, forming an overall dome-shaped curve.

[0061] Furthermore, the first conductive wire 30 has a conductive resin layer 72 and a conductive layer 73, in that order from the support 13 side. The conductive resin layer 72 is a layer containing a conductive resin. The conductive resin layer 72 corresponds to the first blackened layer 34 described above. Therefore, the material, dimensions, etc. of the conductive resin layer 72 are the same as those of the first blackened layer 34. The conductive layer 73 is a layer made of a conductive material such as a metal material. The conductive layer 73 corresponds to the main body 33 described above. Therefore, the material, dimensions, etc. of the conductive layer 73 are the same as those of the main body 33. The rising portion 70 is made up of the conductive resin layer 72 and a part of the lower end side of the conductive layer 73. The conductive layer 73 has a curved portion 71. The curved portion 71 is made up of a part of the upper end side of the conductive layer 73. An inflection point P is set at the point where the rising portion 70 switches to the curved portion 71. The method for setting the inflection point P will be described later.

[0062] As shown in Figure 12(a), the height of the curved portion 71 of the wide portion 60 from the support 13 is defined as "height Ha1". The height of the rising portion 70 of the wide portion 60 from the support 13 is defined as "height Hb1". The line width of the wide portion 60 is defined as "width W1". As shown in Figure 12(b), the height of the curved portion 71 of the narrow portion 61 from the support 13 is defined as "height Ha2". The height of the rising portion 70 of the narrow portion 61 from the support 13 is defined as "height Hb2". The line width of the narrow portion 61 is defined as "width W2".

[0063] The height Ha1 of the curved portion 71 of the wide portion 60 is higher than the height Ha2 of the curved portion 71 of the narrow portion 61. That is, the wide portion 60 has a portion where its height from the support 13 is higher than that of the narrow portion 61. For example, the height Ha1 of the curved portion 71 of the wide portion 60 is set to 4 to 10 μm. In contrast, the height Ha2 of the curved portion 71 of the narrow portion 61 may be set to about 50 to 80% of the height Ha1.

[0064] The height Hb1 of the rising portion 70 of the wide portion 60 may be higher than the height Hb2 of the rising portion 70 of the narrow portion 61, but may also be approximately the same. For example, the height Hb1 of the rising portion 70 of the wide portion 60 is set to 2 to 5 μm. In contrast, the height Hb2 of the rising portion 70 of the narrow portion 61 may be set to about 50 to 100% of the height Hb1. Thus, the ratio of the height Hb2 of the rising portion 70 of the narrow portion 61 to the height Hb1 is greater than the ratio of the height Ha2 of the curved portion 71 of the narrow portion 61 to the height Ha1.

[0065] The width W1 of the wide section 60 is greater than the width W2 of the narrow section 61. For example, the width W1 of the wide section 60 is set to 20-50 μm. In contrast, the width W2 of the narrow section 61 may be set to about 50-80% of the width W1.

[0066] Within a unit region UE set for a certain location of the first conductive wire 30, the wide portion 60 has a part where the height Ha1 from the support 13 is higher than the height Ha2 of the narrow portion 61. This relationship is called the "Ha1 > Ha2" relationship. The range of the first conductive wire 30 corresponding to one side of a single mesh portion 17 is defined as range EX (see Figure 11). Multiple unit regions UE are set for the entire range EX. In Figure 12, four unit regions UE are set for range EX, but since Figure 12 is a schematic diagram, the pitch of the wave pattern may be even smaller and even more unit regions UE may be set. The "Ha1 > Ha2" relationship may hold for all unit regions UE in range EX. In this case, the proportion of unit regions UE that satisfy the "Ha1 > Ha2" relationship within range EX is set to 100%. However, the "Ha1 > Ha2" relationship may not hold for some unit regions UE within range EX. In range EX, the proportion of unit regions UE where the relationship "Ha1 > Ha2" holds may be 50% or more. The same relationship may also hold for the second conductive wire 31. Furthermore, this relationship may hold for the entire conductor pattern 14 shown in Figure 4, or only for a part of it.

[0067] Figures 13 to 15 show an example of an enlarged conductor pattern 14. As shown in Figure 13, the edges 30a and 30b of the first conductive wire 30 both have an irregular wave-like pattern. The edges 31a and 31b of the second conductive wire 31 both have an irregular wave-like pattern. Figure 14 is an enlarged plan view showing the shape of the first conductive wire 30 at various locations in the conductor pattern 14. Figure 14(a) shows the first conductive wire 30 in the conductor pattern 14 near the opening 20 (see Figure 4). Figure 14(b) shows the first conductive wire 30 in the conductor pattern 14 near the center in the x-axis direction. Figure 14(c) shows the first conductive wire 30 in the conductor pattern 14 near the positive end in the x-axis direction. Figure 15 shows the cross-sectional outline of the first conductive wire 30 corresponding to each figure in Figure 14. Figure 15(a) shows the cross-sectional outline of the first conductive wire 30 shown in Figure 14(a). Figure 15(b) shows the cross-sectional outline of the first conductive wire 30 shown in Figure 14(b). Figure 15(c) shows the cross-sectional outline of the first conductive wire 30 shown in Figure 14(c). Note that Figure 15(a) shows the cross-section of the first conductive wire 30 shown in Figure 14(a) at the narrow portion 61. Figure 15(b) shows the cross-section of the first conductive wire 30 shown in Figure 14(b) at the wide portion 60. Figure 15(c) shows the cross-section of the first conductive wire 30 shown in Figure 14(c) at the narrow portion 61.

[0068] Next, the method for setting the inflection point P will be explained with reference to Figure 16. Figure 16(a) shows line L1, which represents the outer shape of the cross-section in region "A" of Figure 15(a). The y-axis and z-axis coordinates are set for this line. Here, line L1 is considered as a graph in yz coordinates. First, line L1 is transformed into an approximation line L2 as shown in Figure 16(b) using a known approximation method. Next, tangent lines TGL are set for each position of the approximation line L2. The angle θ of the tangent line TGL with respect to the y-axis is also measured. At this time, the angle θ is measured from the bottom and the point where the angle θ is less than or equal to a predetermined threshold is set as the inflection point P. An inflection point P is set on line L1 at the point corresponding to the inflection point P set on the approximation line L2. At this time, the region below the inflection point P is set as the rising portion 70, and the region above the inflection point P is set as the curved portion 71. The threshold angle at which the rising section 70 transitions to the curved section 71 can be appropriately changed depending on the material and the amount of conductor, but it can be set in the range of 10 to 45 degrees, for example.

[0069] Next, the operation and effects of the antenna device 1 and the IC card 100 according to this embodiment will be described.

[0070] In the antenna device 1, the conductive wires 30 and 31 have a wide section 60 where the wire width is maximum and a narrow section 61 where the wire width is minimum, within a predetermined range in the first extending direction in which the conductive wires 30 and 31 extend. In this way, by providing a narrow section 61 with a smaller wire width within a predetermined range, the conductive wires can be made thinner, and their visibility can be reduced. Furthermore, instead of making the entire conductive wire 30 and 31 thinner, the strength of the conductive wires 30 and 31 themselves can be increased by providing a wide section 60 with a larger wire width. In addition, the wide section has a portion where its height from the support is greater than that of the narrow section. As a result, it is possible to ensure strength while making the conductive wire thinner and to improve the adhesion strength of the conductive wire to other components.

[0071] When the conductive wires 30 and 31 are viewed in cross-section perpendicular to the first extending direction, they may have a rising portion 70 that rises in the height direction from the support 13 side, and a curved portion 71 provided above the rising portion 70. In this case, by positioning the rising portion 70 on the outer part in the width direction, the visibility near the edges of the conductive wires 30 and 31 can be reduced. Furthermore, by making the upper end portion of the conductive wires 30 and 31 a curved portion 71, the adhesion strength to other members can be improved.

[0072] The edges 30a and 30b of the first conductive wire 30 in the width direction, and the edges 31a and 31b of the second conductive wire 31 in the width direction, may have a wavy shape in plan view. This allows for the regular arrangement of wide portions 60 and narrow portions 61 along the first extending direction. As a result, a good balance can be achieved between the effect of thinning the wires and the effect of ensuring strength.

[0073] The conductive wires 30 and 31 have a conductive resin layer 72 and a conductive layer 73, respectively, from the support 13 side, and the conductive layer 73 may have a curved portion 71. In this case, the conductive resin layer 72 is provided on the support 13, and the conductive layer 73 can be grown on the conductive resin layer 72 by plating. At this time, the shape of the conductive layer 73 having the curved portion 71 can be adjusted by adjusting the shape of the conductive resin layer 72 on the support 13.

[0074] The antenna pattern 19 has a conductor pattern 14 formed by arranging multiple conductive wires 30, 31 in a mesh-like manner. The conductor pattern 14 may have an opening 20 in which the conductive wires 30, 31 are not formed, and a slit 21 extending from the opening to the edge of the conductor pattern 14. In this case, an antenna capable of magnetic coupling with the IC chip 52 can be realized while ensuring transparency.

[0075] The slit 21 is formed by extending the broken sections 40 where the conductive wires 30 and 31 are disconnected from the opening 20 to the edge, and the trajectory TL drawn in the slit 21 passing through each broken section 40 may extend in a curved manner. Here, a slit 21 in which the trajectory TL extends in a straight line (such as in Figures 5(a) and 5(b)) is easily visible because the area where the conductive wires 30 and 31 are absent has a certain shape. On the other hand, if the slit 21 extends in a zigzag pattern and the trajectory TL extends in a curved manner, the area where the conductive wires 30 and 31 are absent is dispersed, making it difficult to see. Therefore, the visibility of the slit 21 can be suppressed. For example, Figure 9 shows the antenna pattern 19 when the slit 21 in Figure 8 is minimized. By drawing a zigzag pattern as shown in Figure 8(b), the position of the slit 21 is difficult to see in Figure 9. This effect of suppressing visibility can also be obtained when using the slits 21 shown in Figures 5(c), 6, and 7, in addition to Figure 8.

[0076] The conductive wires 30 and 31 may have a first blackened layer 34 that constitutes the surface F1 on the side facing the support 13, and a second blackened layer 36 that constitutes the surface F2 opposite to the support 13. In this case, the blackened layers 34 and 36 are less visible than the surface of the main body 33, which has light reflectivity. Therefore, the first blackened layer 34 can suppress the visibility of the conductive wires 30 and 31 when the antenna device 1 is viewed from the surface F1 side. The second blackened layer 36 can suppress the visibility of the conductive wires 30 and 31 when the antenna device 1 is viewed from the surface F2 side.

[0077] The conductivity of the second blackening layer 36 may be higher than that of the first blackening layer 34. Since the second blackening layer 36 does not need to function as a base for forming the main body 33, unlike the first blackening layer 34, increasing its conductivity can improve the conductivity of the entire antenna pattern 19.

[0078] The conductive wires 30 and 31 constituting the antenna pattern 19 each have a main body 33 and metal layers 37 and 38 provided on the surface F2 opposite to the support 13, and the surface of the metal layers 37 and 38 may be gold or silver. In this case, if a specific color is to be given to the antenna pattern 19, the color can be adjusted by adjusting the material of the metal layers 37 and 38 provided on the surface F2.

[0079] The thickness of the metal layers 37 and 38 may be thinner than that of the main body. In this case, the amount of metal in the metal layers 37 and 38 can be reduced to the amount necessary for adjusting the color.

[0080] The IC card 100 comprises the antenna device 1 described above and the IC module 50.

[0081] The IC card 100 can achieve the same functions and effects as the antenna device 1 described above.

[0082] This disclosure is not limited to the embodiments described above.

[0083] For example, the IC card configuration shown in Figure 3 is just one example and may be modified as needed.

[0084] [Form 1] Support and An antenna device comprising a conductor pattern formed by arranging a plurality of conductive wires in a mesh-like manner on the support, The conductive wire has a wide portion where the wire width is maximum and a narrow portion where the wire width is minimum, within a predetermined range in the first extending direction in which the conductive wire extends. The antenna device wherein the wider portion has a portion whose height from the support is greater than that of the narrower portion. [Form 2] When the conductive wire is viewed in cross-section in a cross-section perpendicular to the first extending direction, The antenna device according to Embodiment 1, wherein the conductive wire has a base portion on the support side and a curved portion provided above the base portion. [Form 3] The antenna device according to embodiment 1 or 2, wherein the edge of the conductive wire in the width direction has a wave-shaped form in a plan view. [Form 4] The conductive wire has, in order from the support side, a conductive resin layer and a conductive layer. The antenna device according to Embodiment 2, wherein the conductive layer has the curved portion. [Form 5] The conductor pattern has an opening which is a region where the conductive wire is not formed, and a slit which extends from the opening to the edge of the conductor pattern. The antenna device according to any one of embodiments 1 to 4, wherein the slit is formed by extending the broken portion of the conductive wire from the opening to the edge, and the trajectory drawn in the slit to pass through each broken portion extends in a curved manner. [Form 6] The antenna device according to any one of embodiments 1 to 5, wherein the conductive wire has a first blackened layer constituting the surface on the support side and a second blackened layer constituting the surface on the opposite side of the support. [Form 7] The antenna device according to Embodiment 6, wherein the conductivity of the second blackened layer is higher than that of the first blackened layer. [Form 8] The conductive wire comprises a main body and a metal layer provided on the surface opposite to the support, and the surface of the metal layer is gold or silver, according to any one of embodiments 1 to 7. [Form 9] The antenna device according to Embodiment 8, wherein the thickness of the metal layer is thinner than that of the main body. [Form 10] An antenna device according to any one of Forms 1 to 9, An IC card equipped with an IC module. [Explanation of Symbols]

[0085] 1...Antenna device, 13...Support, 14...Conductor pattern, 20...Opening, 21...Slit, 30...First conductive wire, 31...Second conductive wire, 33...Main body, 34...First blackened layer, 36...Second blackened layer, 37,38...Metal layer, 40...Broken wire section, 50...IC module, 60...Wide layer, 61...Narrow section, 70...Rising section (base), 71...Bent section, 72...Conductive resin layer, 73...Conductive layer, 100...IC card.

Claims

1. Support and An antenna device comprising a conductor pattern formed by arranging a plurality of conductive wires in a mesh-like manner on the support, The conductive wire has a wide portion where the wire width is maximum and a narrow portion where the wire width is minimum, within a predetermined range in the first extending direction in which the conductive wire extends. The antenna device wherein the wider portion has a portion whose height from the support is greater than that of the narrower portion.

2. When the conductive wire is viewed in cross-section in a cross-section perpendicular to the first extending direction, The antenna device according to claim 1, wherein the conductive wire has a base portion on the support side and a curved portion provided above the base portion.

3. The antenna device according to claim 1, wherein the edge portion of the conductive wire in the width direction has a wave-shaped form in a plan view.

4. The conductive wire has, in order from the support side, a conductive resin layer and a conductive layer. The antenna device according to claim 2, wherein the conductive layer has the curved portion.

5. The conductor pattern has an opening which is a region where the conductive wire is not formed, and a slit which extends from the opening to the edge of the conductor pattern. The antenna device according to claim 1, wherein the slit is formed by extending the broken portion of the conductive wire from the opening to the edge, and the trajectory drawn in the slit to pass through each broken portion extends in a curved manner.

6. The antenna device according to claim 1, wherein the conductive wire has a first blackened layer that constitutes the surface on the support side and a second blackened layer that constitutes the surface on the opposite side of the support.

7. The antenna device according to claim 6, wherein the conductivity of the second blackened layer is higher than that of the first blackened layer.

8. The antenna device according to claim 1, wherein the conductive wire comprises a main body and a metal layer provided on the surface opposite to the support, and the surface of the metal layer is gold or silver.

9. The antenna device according to claim 8, wherein the thickness of the metal layer is thinner than that of the main body.

10. An antenna device according to any one of claims 1 to 9, An IC card equipped with an IC module.

Citation Information

Patent Citations

  • Conductive mesh structure and antenna element including same

    JP2023539841A