IC card and method for manufacturing the same

Abstract

This invention provides a dual-interface IC card that improves the reliability of the electrical connection between the IC module and the antenna. [Solution] The IC card 1 comprises a card base 2 with a recess 9, an IC module, and an antenna 80. The IC module comprises a substrate, an IC chip, antenna connection terminals 73a, 73b, and an external connection terminal 71. The antenna 80 comprises an antenna wire 83 and a conductive plate 100. Multiple antenna connection terminals and multiple conductive plates are electrically connected so that the IC chip and antenna constitute a contactless communication circuit. In a cross-sectional view, with respect to a first point where the upper end of the conductive plate connects to the antenna connection terminal and a second point where the lower end of the conductive plate connects to the antenna wire 83, the lower end position of the conductive plate corresponding to the second point is displaced lower than the lower end position corresponding to the first point.

Description

Technical Field

[0001] The present invention relates to a dual interface IC card capable of contact communication and non-contact communication with an external device and a method for manufacturing the same.

Background Art

[0002] Conventionally, as IC cards, contact IC cards that input and output electrical signals through external connection terminals on the card surface, and non-contact IC cards that input and output electrical signals by electromagnetic induction or the like via an antenna are used. In addition to these, contact and non-contact shared IC cards, that is, dual interface IC cards that can realize both the functions of a contact IC card and a non-contact IC card with a single IC chip provided in the card are also used. Among them, the dual interface IC card can be used as a contact IC card effective in suppressing external leakage of input / output data during financial settlement, and can be used as a highly convenient non-contact IC card for data exchange in a proximity state when entering or leaving a room or for ticket gates at stations. For this reason, the dual interface IC card is also becoming more widespread in the market.

[0003] By the way, the manufacture of the dual interface IC card is carried out as follows. First, as described in Patent Document 1, a card base material including one or more core sheets is formed, and an embedding planned area for embedding an IC module is cut from the surface of the card base material. Then, the IC module is embedded in the embedding planned area. Here, a conducting wire is arranged in one of the one or more core sheets, and the conducting wire forms a winding antenna part for providing a non-contact communication function and a contact terminal part that is in electrical contact with the terminals of the IC module, and the contact terminal part is arranged, for example, in a meander shape.

[0004] To expose the contact terminal portion, which is formed by shaping the conductor into a meander shape, from the card substrate, cutting is performed using an end mill. However, due to variations in the thickness of the core sheet that makes up the substrate and the thermal pressure conditions when embedding the conductor into the core sheet, the embedding depth of the conductor from the surface of the card substrate varies. Therefore, it is difficult to reliably expose conductors of about 0.2 mm or less from the card substrate without damaging them, which can lead to a decrease in yield due to breakage of the wound antenna caused by conductor damage, and a decrease in productivity due to a reduction in processing speed.

[0005] On the other hand, to avoid such problems, instead of exposing the contact terminal portion, which has a meander-shaped wire, from the card substrate, it is conceivable to expose the antenna-side connection portion, which consists of conductive plates connected to both ends of the antenna, from the card substrate. Patent Document 2 describes a combination IC card including a card substrate, an antenna wire embedded in the card substrate, an IC module embedded in the card substrate, and a metal plate. The metal plate is embedded in the card substrate and electrically connected to the antenna wire and the IC module. The metal plate also has a plurality of cavities opening on at least one of the first and second main surfaces that define the thickness direction of the plate.

[0006] However, when using a rectangular plate-shaped antenna-side connection part like the one in Patent Document 2, the following problems arise. For example, the metal plate 4 is usually made of copper or stainless steel with a thickness of 0.05 mm or more and 0.10 mm or less. Also, although paste-type solder is exemplified as the joining member 12, even if it were replaced with ACF or the like, the layer thickness would likely be around 0.05 mm or less. On the other hand, the thickness of the module substrate 9 of the IC module 2 is thought to be at most around 0.1 mm to 0.15 mm, even including the antenna connection terminal 11 on the bottom surface of the module substrate 9.

[0007] If the metal plate 4 is thicker than the above, the heat capacity of the metal plate 4 will increase, and there is a risk that the card substrate will deform due to the heat generated when heat-pressing the laminate of card substrates or when connecting the joining members 12. Also, if the rigidity of the metal plate 4 becomes too high, stress will concentrate on the card substrate at both ends of the metal plate 4 when the card is bent, making the card more prone to breakage. On the other hand, if the thickness of the module substrate 9 of the IC module 2 is thicker than the above, the total thickness including the molded part 8 containing the IC chip will exceed 0.6 mm, and there is a risk that the total thickness of the card will exceed the standard thickness of 0.84 mm.

[0008] Here, assuming the thickness of the metal plate 4 is 0.1 mm, the thickness of the joining member 12 is 0.05 mm, and the thickness of the IC module 2 is 0.15 mm, the depth from the card surface to the back side of the metal plate 4 to which the antenna coil 3 is electrically connected will be approximately 0.3 mm. This depth is shallower than half of the total card thickness of 0.84 mm. Incidentally, the thickness direction of the card is the Z-axis direction, the long side direction is the X-axis direction, and the short side direction is the Y-axis direction, and the length and width of the cross-section of the card cut by a plane parallel to the Z-axis and Y-axis are h and b, respectively.

[0009] Here, we assume that the card is bent around the Y-axis. In this case, according to the formulas of material mechanics, the neutral plane of the card in the cross-section cut by the XZ plane lies along a line passing through the center in the thickness direction. Considering the card as a beam along its long side (X-axis direction), and with E as Young's modulus and I as the second moment of area, we can calculate the moment M acting on the beam: M=EI, I=bh 3 This becomes / 12. Also, if the displacement in the Z direction from the neutral plane is z (with the upper side being positive and the lower side being negative), then the bending stress σ(z) is σ(z) = Mz / I.

[0010] From this, it can be seen that the bending stress when the card is bent is smallest near the neutral plane, i.e., the center in the thickness direction of the card, and increases as you approach the front or back surface of the card. However, in the above card configuration, the depth of the back surface of the metal plate 4 is about 1 / 4 of the total card thickness, closer to the surface. At this point, the antenna coil 3, which is electrically connected to the metal plate 4, may detach from the metal plate 4 due to external forces such as repeated bending of the card. Alternatively, the antenna coil 3 may break. This is because the depth position of the antenna coil 3 connected to the metal plate 4 is far from the neutral plane.

[0011] On the other hand, suppose the embedding position of the metal plate 4 is made deeper so that the electrical connection point between the antenna coil 3 and the metal plate 4 is closer to the neutral plane of the card, i.e., the center in the thickness direction. In this case, for the reasons mentioned above, the overall thickness of the metal plate 4 cannot be made extremely thick, so the distance between the module substrate 9 of the IC module 2 and the metal plate 4 increases. As a result, the volume of the bonding member 12 used for the electrical connection between the two increases, making the bonding member 12 more susceptible to damage from external forces such as bending of the card, and thus compromising the reliability of the connection between the IC chip and the antenna. [Prior art documents] [Patent Documents]

[0012] [Patent Document 1] Japanese Patent Publication No. 2019-219732 [Patent Document 2] Japanese Patent Publication No. 2005-50326 [Overview of the Initiative] [Problems that the invention aims to solve]

[0013] This disclosure is made in view of the above circumstances and aims to provide a dual-interface IC card and a method for manufacturing the same that can improve the reliability of the electrical connection between the IC module and the antenna. [Means for solving the problem]

[0014] The first configuration of a dual-interface IC card capable of contact and contactless communication according to this embodiment comprises a card base having a recess, an IC module embedded in the recess, and an antenna disposed inside the card base, wherein the IC module comprises a substrate, an IC chip disposed on one side of the substrate and a plurality of antenna connection terminals electrically connected to the IC chip, and an external connection terminal disposed on the other side of the substrate, electrically connected to the IC chip and exposed on the side of the card base where the recess is formed, and the antenna comprises an antenna wire and a plurality of conductive plates disposed at the end of the antenna wire and electrically connected to the antenna wire. The plurality of antenna connection terminals and the plurality of conductive plates are electrically connected by a conductive adhesive layer, thereby constituting a contactless communication circuit between the IC chip and the antenna. In a cross-sectional view including the thickness direction and the long side direction of the card base, the end of the recess of the conductive plate along the thickness direction is defined as the upper end, the end opposite to the upper end is defined as the lower end, the point where the upper end of the conductive plate is electrically connected to the antenna connection terminal is defined as the first point, and the point where the lower end of the conductive plate is electrically connected to the antenna wire is defined as the second point. In this case, the position of the lower end of the conductive plate corresponding to the second point is displaced lower than the position of the lower end corresponding to the first point.

[0015] Furthermore, in an IC card relating to a second configuration according to another form of this embodiment, in the first configuration, when the thickness of the conductive plate at the first point is defined as the first thickness and the thickness of the conductive plate at the second point is defined as the second thickness in a cross-sectional view including the thickness direction and the long side direction of the card base, the position of the lower end of the conductive plate corresponding to the second point may be displaced downward from the position of the lower end corresponding to the first point because the second thickness is greater than the first thickness.

[0016] Furthermore, in an IC card relating to a third configuration according to another form of this embodiment, in the first configuration, in a cross-sectional view including the thickness direction and the long side direction of the card base, the conductive plate of a predetermined thickness is bent in a region other than the second point, so that the position of the lower end of the conductive plate corresponding to the second point is displaced downward from the position of the lower end corresponding to the first point.

[0017] Furthermore, in the IC card relating to the fourth configuration according to another form of this implementation, in the third configuration, the conductive plate may be arranged along the long side direction at the first and second points in a cross-sectional view including the thickness direction and the long side direction of the card base.

[0018] Furthermore, in an IC card relating to a fifth configuration according to another form of this implementation, in any of the first to fourth configurations, the plurality of conductive plates may consist of a first plate and a second plate, and in a cross-sectional view including the thickness direction and the long side direction of the card base, the first plate and the second plate may be arranged symmetrically with respect to the thickness direction.

[0019] A method for manufacturing a dual-interface IC card capable of contact and contactless communication with external devices, according to the sixth configuration of this embodiment, comprises: an antenna forming step of bonding a plurality of conductive plates to a first substrate, then embedding an antenna wire in the first substrate while welding it to the plurality of conductive plates and applying heat and pressure, thereby forming an antenna on one side of the first substrate where both ends of the antenna wire are electrically connected to the plurality of conductive plates; a lamination step of laminating a second substrate on the first substrate with the antenna formed thereon, sandwiching the antenna; a punching step of punching out a laminate formed by at least the first substrate and the second substrate into a card-sized card base; a recess forming step of forming a recess in the card base for embedding an IC module, the opening of the recess on the surface of the card base on the side of the card base closer to the first substrate than to the second substrate; and a substrate, an IC chip and a plurality of antenna connection terminals electrically connected to the IC chip arranged on one side of the substrate, and a front The present invention provides an IC module preparation step of preparing an IC module comprising an IC chip and an external connection terminal that is electrically connected to the surface of the card base in which the recess is formed, and an antenna connection step of electrically connecting a plurality of antenna connection terminals and a plurality of conductive plates facing each other via a conductive adhesive layer so that the IC chip and the antenna constitute a contactless communication circuit, and an IC module bonding step of bonding the IC module to the recess of the card base, wherein in a cross-sectional view including the thickness direction and the long side direction of the card base, the end of the conductive plate on the opening side of the recess along the thickness direction is defined as the upper end, the end opposite to the upper end is defined as the lower end, the point where the upper end of the conductive plate is electrically connected to the antenna connection terminal is defined as the first point, and the point where the lower end of the conductive plate is electrically connected to the antenna wire is defined as the second point, the position of the lower end of the conductive plate corresponding to the second point is displaced downward from the position of the lower end corresponding to the first point. [Effects of the Invention]

[0020] According to the present embodiment, it is possible to provide a dual-interface IC card and a method for manufacturing the same that can improve the reliability of the electrical connection between an IC module and an antenna.

Brief Description of Drawings

[0021] [Figure 1] FIG. 1 is a plan view for explaining the structure of a dual-interface IC card according to an embodiment of the present disclosure and an enlarged plan view of the vicinity of a recess of a card substrate with an IC module removed. [Figure 2] FIG. 1(b) is a cross-sectional view of line A-A including an IC module in FIG. 1(a), an enlarged view of part B of the cross-sectional view, and an explanatory view of a conductive plate viewed in cross-section. [Figure 3] FIG. 2(a) is a cross-sectional view corresponding to FIG. 2(a) for explaining a method for manufacturing a dual-interface IC card according to an embodiment of the present disclosure. [Figure 4] FIG. 2(a) is a cross-sectional view corresponding to FIG. 2(a) for explaining a method for manufacturing a dual-interface IC card according to an embodiment of the present disclosure. [Figure 5] FIG. 2(d) is a view of an IC module as seen from the front and back, respectively, and an enlarged view of part C of FIG. 2(b). [Figure 6] FIG. 2(c) is an explanatory view of a conductive plate viewed in cross-section corresponding to FIG. 2(c) for explaining a modified example of the conductive plate.

Embodiments for Carrying Out the Invention

[0022] Hereinafter, an example of the IC card of the present disclosure will be described with reference to the drawings and the like. However, the IC card of the present disclosure is not limited to the embodiments and examples described below.

[0023] The following figures are schematic representations. Therefore, the size and shape of each part have been exaggerated as appropriate for ease of understanding. Furthermore, hatching indicating cross-sections of members has been omitted in each figure as appropriate. The dimensions and other numerical values ​​and material names of each member described herein are examples of embodiments and are not limiting; they can be selected and used as appropriate. In this specification, terms specifying shape and geometric conditions, such as parallel, orthogonal, and perpendicular, are used not only in their strict sense but also to include substantially equivalent states.

[0024] 1. Embodiments relating to this disclosure An example of an embodiment of the IC card of this disclosure will be described. The IC card 1 of the embodiment of this disclosure is a dual-interface IC card. Here, for the sake of explanation, an XYZ coordinate system is set for the IC card 1. First, as shown in Figures 1(a), 2(a), and 2(b), the Z axis is taken in the direction of the normal to the main surface of the IC card 1. Then, the direction from the main surface on which the external connection terminals 71 of the IC module 70 are not located toward the main surface on which the external connection terminals 71 are located is defined as the +Z direction or upward in the thickness direction, and the opposite direction is defined as the -Z direction or downward in the thickness direction.

[0025] Furthermore, when viewing IC card 1 from the +Z direction, the line perpendicular to both short sides of IC card 1 and the Z axis is defined as the X axis. Also, the direction from one short side closer to the external connection terminal 71 to the other short side is defined as the +X direction or right direction, and the opposite direction is defined as the -X direction or left direction. In addition, the axis perpendicular to the X and Z axes is defined as the Y axis, and the direction from one long side farther from the external connection terminal 71 to the other long side is defined as the +Y direction or upward, and the opposite direction is defined as the -Y direction or downward.

[0026] Figure 1(a) is a plan view of IC card 1 as seen from the +Z direction. Figure 1(b) is an enlarged plan view showing the configuration of card base 2 with the IC module 70 removed from Figure 1(a). Figure 2(a) is a cross-sectional view of IC card 1 from Figure 1(a) as seen from the -Y direction, cut along line AA parallel to the X axis. Figure 2(b) is an enlarged view of section B, enclosed by a dashed line and centered on the left half of IC module 70, in the cross-sectional view of IC card 1 from Figure 2(a). Figure 2(c) is a diagram illustrating the details of the configuration of the first plate 110 in Figure 2(b).

[0027] On the other hand, Figures 3(a), 3(b), 3(c), and 4(a), 4(b), 4(c) are diagrams illustrating the manufacturing method and process of the IC card 1, and correspond to the cross-sectional view shown in Figure 2(a). Figure 5(a) is a view of the IC module 70 from the +Z direction, looking from the external connection terminal 71 side, similar to Figure 1(a). Figure 5(b) is a view of the IC module 70 from the -Z direction, opposite to that of Figure 5(a). Here, most of the molded portion 74b of the IC chip body 74 is omitted in order to allow visibility of the interior. Figure 5(c) is an enlarged cross-sectional view of section C enclosed by a solid line near the antenna connection terminal 73a in Figure 2(b).

[0028] As shown in Figure 1(a), the IC card 1 has the form of a thin, roughly rectangular plate with rounded corners when viewed from the +Z direction in a plan view. Furthermore, on the +Z-side surface of the dual-interface IC card, an IC module 70 including an external connection terminal 71 is positioned slightly to the upper left of the center, i.e., closer to the -X direction and closer to the +Y direction than the center. As shown in Figures 1(a), 2(a), and 2(b), the IC module 70 is embedded in a recess 9 formed in the card base 2, and is positioned so that the +Z-side surface of the external connection terminal 71 is substantially flush with the +Z-side surface of the card base 2. This form of the IC card 1 conforms to the international IC card standard ISO / IEC 7816-1. Additionally, as shown in Figure 1, the external connection terminal 71 has defined sections as defined by the ISO / IEC 7816-2 and ISO / IEC 7816-3 standards.

[0029] This standard specifies the following external terminals: C1 (supply voltage input terminal), C2 (reset signal input terminal), C3 (clock signal input terminal), C5 (signal ground terminal), and C7 (series data input or output terminal). C6 is a standard or individually-use terminal and is not normally used. C4 and C8 are unused terminals reserved for future use. C1, C2, C3, C5, and C7 can be abbreviated as VCC, RST, CLK, GND, and I / O, respectively.

[0030] The detailed configuration will be described later, but as shown in Figure 5(b), the IC chip 74a has multiple pads 74p formed on it. Each of the multiple pads 74p on the IC chip 74a is electrically connected to each terminal of the external connection terminal 71 (not shown, but for example, terminals C1, C2, C3, C5, and C7) via conductive wires 75. In addition, two of the other pads 74p on the IC chip 74a are electrically connected to antenna connection terminals 73a and 73b formed on the side of the substrate 72 opposite to the external connection terminal 71, respectively, via conductive wires 75.

[0031] As shown in Figures 1(a) and 2(b), the antenna connection terminal 73a is electrically connected to the first plate 110, which is a conductive plate 100, via the conductive adhesive layer 11. The first plate 110 is welded to one end of the antenna wire 83. Furthermore, although not shown in Figure 2(b), the antenna connection terminal 73b is also electrically connected to the second plate 120 via the conductive adhesive layer 11, and the second plate 120 is welded to the other end of the antenna wire 83. Thus, the antenna connection terminals 73a and 73b are electrically connected to both ends of the antenna wire 83.

[0032] As a result, multiple pads 74p on the IC chip 74a and the antenna connection terminals 73a and 73b are electrically connected via wires 75, with the antenna connection terminal 73a electrically connected to one end of the antenna 80 via the conductive adhesive layer 11 and the first plate 110. The antenna connection terminal 73b is electrically connected to the other end of the antenna 80 via the conductive adhesive layer 11 and the second plate 120. Consequently, the IC chip 74a and the antenna 80 form a closed, contactless communication circuit.

[0033] On the other hand, Figure 1(b) shows the planned placement areas for the antenna connection terminals 73a and 73b when the IC module 70 is embedded in the recess 9 of the card base 2, indicated by roughly rectangular dashed lines. As shown in Figure 1(b), the card base 2 is assumed to be viewed from above with the IC module 70 removed from the side where the recess 9 is formed, or with the IC module 70 visible through it. In other words, Figure 1(b) is an enlarged plan view showing the configuration of the card base 2 with the IC module 70 removed as in Figure 1(a). Also, Figure 1(b) can be said to be a plan view of the card base 2 near the recess 9 of the card base 2 with the IC module 70 mounted on it, with the IC module 70 visible through it.

[0034] In the cross-sectional view of Figure 2(b), in a cross-sectional view including the thickness direction (Z-axis direction) and the long side direction (X-axis direction) of the card base 2, the first plate 110 has a relatively thin flat plate along the long side direction of the card base 2, with a flat portion 111 extending in a plane (XY plane) that is aligned with the main surface direction of the card base 2. Furthermore, the first plate 110 has a displacement portion 112 with increasing thickness on the lower side relative to the flat portion 111, such that its lower end is displaced below the lower end of the flat portion 111 as it moves away from the center of the recess 9 provided in the card base 2.

[0035] To rephrase the above, it is as follows: In the cross-sectional view of the card base 2 in Figure 2(b), including the thickness direction and the long side direction, the end on the opening side of the recess 9 of the conductive plate 100 (first plate 110) along the thickness direction is defined as the upper end, and the end opposite to the upper end is defined as the lower end. The upper end of the conductive plate 100 is the end on the +Z direction side of the conductive plate 100, and the lower end of the conductive plate 100 is the end on the -Z direction side of the conductive plate 100. The point where the upper end of the first plate 110 is electrically connected to the antenna connection terminal 73a is defined as the first point, and the point where the lower end of the first plate 110 is electrically connected to the antenna wire 83 is defined as the second point. The first point refers to the location P1 shown by the dashed line in Figure 2(b), and the second point refers to the location P2 shown by the dashed line.

[0036] In this case, the lower end of the first plate 110 corresponding to the second point P2 is displaced lower than the lower end corresponding to the first point P1. That is, when comparing the lower end positions of the first plate 110, the lower end of the second point P2 is displaced lower than the lower end corresponding to the first point P1 (the lower end along the Z-axis direction passing through the first point P1) because the first plate 110 is configured in such a way. In this embodiment, the thickness of the first plate 110 along the long side is greater on the side farther from the center of the recess 9 than on the side closer to the center of the recess 9, and it is configured to protrude downwards. The second plate 120 is also configured to be symmetrical with respect to a straight line parallel to the Z-axis passing through the center of the recess 9.

[0037] In a cross-sectional view including the thickness direction and the long side direction of the card base 2, the thickness of the conductive plate 100 at the first point P1 is defined as the first thickness, and the thickness of the conductive plate at the second point P2 is defined as the second thickness. In this case, because the second thickness is greater than the first thickness, the position of the lower end of the conductive plate 100 corresponding to the second point P2 is displaced lower than the position of the lower end corresponding to the first point P1.

[0038] By providing the conductive plate 100 having the above configuration in the IC card 1 of this embodiment, the following can be achieved without making the overall thickness of the conductive plate 100 unnecessarily thick. Specifically, the first point P1 where the conductive plate 100 and the antenna connection terminals 73a and 73b are electrically connected can be positioned higher, and the second point P2 where the conductive plate 100 and the antenna wire 83 are electrically connected can be positioned lower. This suppresses thermal deformation of the surrounding substrate during electrical connection between the conductive plate 100 and the antenna connection terminals 73a and 73b of the IC module 70, which would occur if the overall thickness of the conductive plate 100 were increased.

[0039] Furthermore, in the conductive plate 100, the lower end corresponding to the second point P2 is displaced lower than the lower end corresponding to the first point P1. This reduces the thickness and volume of the conductive adhesive layer 11 used for the electrical connection between the IC module 70 and the conductive plate 100, thereby suppressing a decrease in the reliability of the electrical connection between the IC module and the antenna due to the destruction of the conductive adhesive layer 11. Moreover, since the electrical connection point between the conductive plate 100 and the antenna wire 83 can be displaced near the center in the thickness direction of the card base 2, the risk of the antenna wire 83 detaching from the conductive plate 100 due to external forces such as bending, or the risk of the antenna wire 83 breaking, can be reduced. As a result, this embodiment provides a dual-interface IC card and a method for manufacturing the same that can improve the reliability of the electrical connection between the IC module and the antenna.

[0040] The configuration of the IC card 1 of this embodiment and the details of its manufacturing method are described below.

[0041] (a) Card base The card base 2 refers to the card body of the IC card 1, excluding the IC module 70. As shown in Figures 2(a) and 2(b), the card base 2 typically has a structure in which an oversheet layer 8, core layers 7 and 6, antenna holding layers 5 and 4, and an oversheet layer 3 are stacked in this order from one end on the -Z side in the thickness direction. An antenna 80, including an antenna wire 83 formed from a covered conductor or the like and wound in a loop shape, and a conductive plate 100, is arranged between the antenna holding layers 5 and 4.

[0042] The card base 2 may refer to both the card base 2 before the recess 9 is formed and the card base 2 after the recess 9 is formed, and may refer to both the card base 2 without the antenna 80 and the card base 2 with the antenna 80. The ends of both antenna wires 83 of the antenna 80 are electrically connected to the first plate 110 on the -X side and the second plate 120 on the +X side, which are arranged along the X-axis relative to each other. The first plate 110 and the second plate 120 are elements of the conductive plate 100. In this disclosure, the center of the recess 9 refers to the center of the recess 9 (the recess formed by the first recess 91 and the second recess 92) when the card base 2 is viewed from the +Z side, i.e., the centroid of the figure formed by the contour line of the recess 9 or a straight line parallel to the Z axis passing through the centroid.

[0043] In this embodiment, for the sake of explanation, the antenna wire 83 of the antenna 80 is described as a single conductor wound in a loop without any branches, but this disclosure is not limited to this, and also includes cases where the antenna wire 83 is appropriately branched and has three or more ends. In addition, three or more conductive plates 100 can be arranged according to the number of ends of the antenna wire 83.

[0044] Furthermore, the layer configuration of the card substrate 2 is not limited to those described above; it may also be a three-layer configuration of an oversheet layer, an antenna retaining layer, and another oversheet layer, or a two-layer configuration of an antenna retaining layer and another antenna retaining layer. Alternatively, the layer configuration of the card substrate 2 may be a multilayer configuration of eight or more layers, such as an oversheet layer, a core layer, an inner layer, an antenna retaining layer, an antenna retaining layer, an inner layer, a core layer, and an oversheet layer. In addition, printing or embedding of a magnetic stripe may be applied to the surface of the oversheet layer 3 or 8 of the card substrate 2 that is opposite to the antenna retaining layer 4 or core layer 7, or printing may be applied to the surface of the antenna retaining layer 4 or core layer 7 adjacent to the oversheet layer 3 or 8.

[0045] From the standpoint of conforming to standards such as ISO / IEC 7816-1, the thickness of the card base 2 is preferably 0.76 mm or more and 0.84 mm or less, but it may be outside this range.

[0046] (i) Core layer The core layer is also called the inner layer. A wide variety of white or colored plastic sheets can be used for core layers 6 and 7, and the following single films or composite films thereof can be used. For example, polyethylene terephthalate (PET), PET-G (terephthalic acid-cyclohexanedimethanol-ethylene glycol copolymer), polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polycarbonate, polyamide, polyimide, cellulose diacetate, cellulose triacetate, polystyrene-based materials, ABS, polyacrylic acid ester, polypropylene, polyethylene, polyurethane, etc. The thickness of core layers 6 and 7 can be appropriately selected considering the overall thickness of the card, but for example, it can be between 0.10 mm and 0.38 mm.

[0047] (ii) Antenna holding layer The antenna retaining layer is also called the inner layer, similar to the core layer. The antenna retaining layers 4 and 5 have the function of sandwiching and holding the antenna 80, and a wide range of plastic sheets similar to those used for the core layers 6 and 7 can be used. The antenna retaining layers 4 and 5 may be made of the same material as the core layers 6 and 7, or they may be made of different materials. The thickness of the antenna retaining layers 4 and 5 can be appropriately selected considering the overall thickness of the card, but for example, it can be between 0.10 mm and 0.38 mm.

[0048] (iii) Oversheet layer For the oversheet layers 3 and 8, the same material as the core layer and antenna holding layer is usually used, but transparent materials with a thickness of approximately 0.05 mm or more and 0.18 mm or less are often used. From the viewpoint of preventing curling when the laminate of the core layer, antenna holding layer and oversheet layer is integrated by heat pressing or the like, it is preferable that the thicknesses of the oversheet layers 3 and 8 are the same, but they do not necessarily have to be the same. This point also applies to the core layers 6 and 7 and the antenna holding layers 4 and 5 mentioned above.

[0049] The material of the oversheet layer can be any material that is heat-adherent. However, even if the oversheet layer itself is not heat-adherent, the two can be integrated by adding a layer of a known adhesive that generates adhesive force when heated between the core layer and the oversheet layer. Furthermore, when the IC card 1 is used as a magnetic card, a magnetic stripe may be pre-embedded in either or both of the oversheet layers 3 and 8 on the main surface side opposite to either or both of the antenna holding layer 4 and the core layer 7 by thermal transfer or the like.

[0050] (iv) Antenna sheet In this embodiment, as will be described later, an antenna 80 is formed on one surface of the antenna holding layer 4 or 5, and both ends of the antenna wires 83 constituting the antenna 80 are electrically connected to the first plate 110 and the second plate 120. The formation of the antenna 80 on the antenna holding layer 4 or 5 is carried out, for example, as follows. First, the first plate 110 and the second plate 120 are bonded and fixed to the surface of the antenna holding layer 4 facing the antenna holding layer 5 by applying heat and pressure or the like. At this time, adhesive may be applied to the surface of the antenna holding layer 4 before placing the first plate 110 and the second plate 120. The first plate 110 and the second plate 120 are arranged side by side in the left-right direction at the planned mounting position of the IC module 70, and a portion of them is positioned to overlap with the antenna connection terminals 73a and 73b of the IC module 70 when mounted.

[0051] Here, when bonding and fixing the first plate 110 and the second plate 120 to the surface of the antenna holding layer 4 facing the antenna holding layer 5, it is preferable to arrange the first plate 110 and the second plate 120 as follows. That is, the first plate 110 and the second plate 120 are arranged such that the displacement portions 112 at both ends of the first plate 110 and the second plate 120 protrude in the direction from the antenna holding layer 4 toward the antenna holding layer 5. By doing so, bonding and fixing the first plate 110 and the second plate 120 to the antenna holding layer 4 becomes easier compared to the case where the displacement portions 112 at both ends of the first plate 110 and the second plate 120 protrude in the direction from the antenna holding layer 5 toward the antenna holding layer 4.

[0052] Assume that the first plate 110, etc., is placed on the antenna retaining layer 4 such that the displacement portions 112 at both ends of the first plate 110, etc., protrude in the direction from the antenna retaining layer 4 toward the antenna retaining layer 5. In this case, when forming the recess 9 for embedding the IC module 70 in the card base 2, the opening of the recess 9 will be formed on the surface closer to the antenna retaining layer 4 than to the antenna retaining layer 5.

[0053] Conversely, when bonding and fixing the first plate 110 and the second plate 120 to the surface of the antenna holding layer 5 facing the antenna holding layer 4, the displacement portions 112 at both ends of the first plate 110, etc., are oriented to protrude in the direction from the antenna holding layer 4 toward the antenna holding layer 5. The first plate 110 and the second plate 120 will henceforth be referred to as the first plate, etc. In this case, the flat portion 111 of the first plate 110, etc., may lift up from the antenna holding layer 5, making it difficult to bond and fix the first plate 110, etc., to the antenna holding layer 5.

[0054] However, it is also possible to bond and fix the first plate 110, etc., to the antenna holding layer 5 by applying heat and pressure to firmly embed the displacement portion 112 of the first plate 110, etc., into the antenna holding layer 5. Alternatively, as will be described later, it is also possible to bond and fix the first plate 110, etc., to the antenna holding layer 5 by providing recesses or through holes in a part of the antenna holding layer 5 in advance to accommodate the displacement portion 112.

[0055] Subsequently, the tip of the antenna wire 83 is welded to either the tip of the displacement portion 112 of the first plate 110 or the second plate 120. Then, starting from this point, a predetermined heat pressure is applied to the antenna wire 83, and the insulated conductor antenna wire 83, which is covered with an insulating material, is embedded into the surface of the antenna holding layer 4 by a winding forming machine. That is, while applying a predetermined heat pressure to the antenna wire 83, the antenna supply head is drawn in a loop shape as shown in Figure 1(a), and the antenna wire 83 supplied from the antenna supply head is sequentially embedded into the antenna holding layer 4. The embedded antenna wire 83 is cut, and the tip of the cut antenna wire 83 is welded to the other of the first plate 110 or the second plate 120, using the cut tip as the endpoint.

[0056] The starting and ending ends of the antenna wire 83 are electrically connected to either the first plate 110 or the second plate 120 by welding. In this way, an antenna holding layer 4 (antenna sheet 12) with the antenna 80 formed is obtained. The intermediate product in which the antenna 80 is embedded in the antenna holding layer 4 or 5 is sometimes referred to as the antenna sheet 12. The antenna sheet 12 can be distributed to the market as a component for manufacturing the IC card 1 on its own. Alternatively, a business model may exist in which sheet material such as the antenna holding layer is supplied to a processing company, which processes it into an antenna sheet 12 and delivers it to the supplier.

[0057] (v) antenna In the antenna 80 formed on the antenna holding layer 4, the antenna connection terminals 73a and 73b of the IC module 70 are electrically connected to a pair of first plates 110 and second plates 120 to which multiple ends of the antenna wire 83 are electrically connected. The antenna holding layer 4 may be replaced with an antenna holding layer 5. As a result, the IC chip 74a and antenna 80 of the IC module 70 constitute a contactless communication circuit. This communication circuit may perform proximity communication using, for example, the 13.56 MHz HF frequency band specified in ISO / IEC 18092 or ISO / IEC 144443. Alternatively, it may perform communication using other frequencies, such as the 920 MHz UHF frequency band, the 125 kHz LF frequency band, or the 2.45 GHz microwave frequency band.

[0058] When the IC card 1 is held over an external device such as a reader / writer, the communication circuit generates an electromotive force and current due to the magnetic field and radio waves formed by the reader / writer, supplying power to the IC chip 74a. This enables the IC chip 74a to be driven, allowing for contactless transmission and reception of information with the reader / writer, and enabling reading and rewriting of information in the memory.

[0059] The antenna wire 83 constituting the antenna 80 is typically formed from a coated conductor, in which a copper wire is covered with an insulating material. In addition, copper alloy wires such as Cu-Ni, Cu-Cr, Cu-Zn, Cu-Sn, and Cu-Be, or various metal wires and metal alloy wires such as iron, stainless steel, and aluminum can also be selected. The IC card 1 can be manufactured at a lower cost compared to methods such as copper foil etching by using coated conductors. However, the IC card 1 of this disclosure may also use antenna wires formed by copper foil etching or metal foil punching methods.

[0060] The diameter of the antenna wire 83 is not particularly limited as long as it ensures the characteristics of a non-contact communication circuit, but for example it can be 0.03 mm or more and 0.30 mm or less, preferably 0.05 mm or more and 0.15 mm or less. By using the latter range, durability against heat and pressure from embedding and external forces from cutting can be improved, and good communication characteristics can be ensured.

[0061] (vi) Conductive plates (first plate and second plate) Next, the details of the first plate 110 and the second plate 120 that constitute the conductive plate 100 will be described. As shown in Figure 1(b), both the first plate 110 and the second plate 120 have a substantially rectangular shape in a plan view along the Z-axis direction, which is the normal direction to the main surface of the IC card 1.

[0062] On the other hand, as shown in Figure 2(b), the first plate 110 and the second plate 120 have the following shapes when viewed in cross-section along a plane that includes the Z-axis direction, which is the normal direction to the main surface of the IC card 1, and the long side direction (X-axis direction) of the card base 2. Specifically, the first plate 110 comprises a flat portion 111 along the long side direction (X-axis direction) of the card base 2, and a displacement portion 112 extending from one end of the flat portion 111, which is thicker than the thickness of the flat portion 111 and protrudes downward (towards the -Z direction). The displacement portion 112 is provided at one end of the flat portion 111 that moves away from the center of the recess 9 toward the end of the card base 2.

[0063] As shown in Figure 2(a), the first plate 110 and the second plate 120 constituting the conductive plate 100 are arranged symmetrically with respect to the Z axis. This ensures that the first plate 110 and the second plate 120 have uniform durability and connection reliability against external loads such as bending of the card. The first plate and the second plate are each composed of a relatively thin flat portion 111 and a relatively thick displacement portion 112, respectively, and have a cross-sectional shape that is approximately L-shaped or approximately inverted L-shaped. The conductive plate 100 may be formed by integrally creating the flat portion 111 and the displacement portion 112, or it may be formed by combining the flat portion 111 and the displacement portion 112, which are separate components.

[0064] In a cross-sectional view of the card base 2 including the thickness direction and the long side direction, the end on the opening side of the recess 9 of the conductive plate 100 along the thickness direction is defined as the upper end, and the end on the opposite side of the upper end is defined as the lower end. The end on the opening side of the recess 9 (upper end) is the upper end portion on the +Z direction side of the conductive plate 100 in the cross-sectional view, and the lower end is the lower end portion on the -Z direction side of the conductive plate 100 in the cross-sectional view. Taking the first plate 110 as an example, the point where the upper end of the first plate 110 is electrically connected to the antenna connection terminal 73a is defined as the first point P1, and the point where the lower end of the first plate 110 is electrically connected to the antenna wire 83 is defined as the second point P2. At this time, the position of the lower end of the first plate 110 corresponding to the second point P2 is displaced downward (towards the -Z direction) compared to the position of the lower end corresponding to the first point P1.

[0065] In this embodiment, the downward displacement of the lower end position corresponding to the second point P2 relative to the lower end position corresponding to the first point P1 is achieved by the following configuration. That is, the thickness of the displacement portion 112 is greater than the thickness of the flat portion 111 of the first plate 110, and the upper end of the displacement portion 112 is substantially flush with the upper end of the flat portion 111, while the lower end of the displacement portion 112 protrudes downward from the lower end of the flat portion 111. These points remain the same even if the first plate 110, antenna connection terminal 73a, and antenna wire 83 are replaced with the second plate 120, antenna connection terminal 73b, and antenna wire 83, respectively.

[0066] The shape of the conductive plate 100 in cross-section will be described in detail using the first plate 110, which is one of the conductive plates 100, as an example. As shown in Figure 2(c), the portion of the first plate 110 extending from near the center to the right along the X-axis is a flat portion 111. The surface of the flat portion 111 on the +Z side is substantially flush with the bottom surface 91a of the first recess 91 of the card base 2. However, the front and back surfaces of the flat portion 111 do not need to be perfectly flat; it is sufficient if they are substantially approximate to be flat. Also, the flat portion 111 does not need to be perfectly parallel to the Y-axis, which is the short side direction; it may have an inclination of about 5° or less with respect to the X-axis.

[0067] The lateral length of the flat portion 111 in a cross-sectional view can be expressed as L11, and the thickness of the flat portion 111 can be expressed as H11. Similarly, the lateral length of the displacement portion 112 in a cross-sectional view can be expressed as L12, and the thickness of the displacement portion 112 can be expressed as H12. Furthermore, the lateral length of the entire first plate 110 in a cross-sectional view can be expressed as L1, and its thickness can be expressed as H1. These dimensions may be arbitrary values, but for example, L1 is preferably between 4 mm and 10 mm. Also, the ratio of L12 / L1 is preferably between 0.4 and 0.8, and the ratio of H12 / H1 is preferably between 0.25 and 0.75. The first thickness described above is H11, and the second thickness is H1. In this case, because the second thickness H1 is thicker than the first thickness H11, the position of the lower end of the conductive plate 100 corresponding to the second point P2 can be displaced downward from the position of the lower end corresponding to the first point P1.

[0068] By keeping the L12 / L1 ratio within the above range, the width of the conductive plate 100 can be kept within a certain range, thereby suppressing an increase in heat capacity. Furthermore, by increasing the distance between the connection point between the conductive plate 100 and the antenna connection terminal 73a and the displacement part 112, adverse effects from the displacement part 112, such as heat transfer and internal stress due to the increase in heat capacity, can be suppressed. In addition, by keeping the H12 / H1 ratio within the above range, the connection point in the thickness direction between the conductive plate 100 and the antenna wire 83 can be brought as close as possible to the center in the thickness direction of the card base 2, which is the neutral plane. Furthermore, the distance between the conductive plate 100 and the antenna connection terminal 73a can be appropriately reduced, improving the electrical connection reliability between the two.

[0069] Incidentally, as shown in Figure 1(b), the first plate 110 and the second plate 120 have, in a plan view, a region that overlaps with the first recess 91, that is, a region exposed from the card base 2, and a region that is located outside the first recess 91 and embedded inside the card base 2.

[0070] As shown in Figure 1(b), in the plan view, the lines that overlap the -X-direction side 93a and the +X-direction side 93b of the outer circumference 93 of the recess 9 are denoted as lines m1 and m2, respectively. In this case, the region of the first plate 110 on the +X-direction side of line m1 is exposed from the card base 2 in the first recess 91, and the region on the -X-direction side of line m1 is covered by the card base 2. Similarly, the region of the second plate 120 on the -X-direction side of line m2 is exposed from the card base 2 in the first recess 91, and the region on the +X-direction side of line m2 is covered by the card base 2.

[0071] Taking the first plate 110 as an example, the width of the first plate 110 exposed from the card base 2 in the first recess 91 along the X-axis direction is the same as the width of the first recess 91, and is narrower than the width including the covering portion by the card base 2. Here, in a plan view from the +Z direction, it is preferable that the area of ​​the antenna connection terminal 73a when the IC module 70 is mounted is included in the area exposed on the bottom surface 91a of the first recess 91 of the first plate 110. This is because a stable contact area for electrical connection between the antenna connection terminal 73a and the first plate 110 can be obtained. The same applies to the second plate 120. In this way, the multiple antenna connection terminals 73a and 73b are electrically connected to the conductive plates, the first plate 110 and the second plate 120, on the surface facing the opening side of the recess 9 of the card base 2.

[0072] Furthermore, because a portion of the first plate 110 and the second plate 120 are covered by the card base 2 in this manner, the holding effect of the first plate 110 and the second plate 120 against external forces such as the cutting resistance of the end mill blade when forming the recess 9 is enhanced. Therefore, it is possible to suppress the plates from unintentionally peeling off from the card base 2 and shifting their position.

[0073] The first plate 110 and the second plate 120 may have a laminated structure including at least two layers: a first member and a second member laminated on the +Z side of the first member. In this case, it is preferable that the second member is less susceptible to oxidation than the first member. A member that is less susceptible to oxidation can be rephrased as, for example, if both the first and second members are metals, the second member being a metal with a lower ionization tendency than the first member. As an example of such metals, the first member may be aluminum, iron, nickel, or copper, and the second member may be silver, palladium, platinum, or gold.

[0074] Considering the ease of material procurement, cost, processability, and electrical properties, it is preferable to use highly conductive copper as the first component and silver plating as the second component among those listed above. By using copper, which can ensure sufficient conductivity, as the first component, and silver, which is resistant to oxidation and easily exposes the metal interface when cutting the resin layer with an end mill, as the second component, good electrical properties and processability can be obtained while suppressing cost increases.

[0075] On the other hand, the first plate 110 and the second plate 120 may not have the laminated structure of two or three or more layers described above, but may be made of only a single material. In this case, the single material is limited to a conductive material, and for example, the materials described above as the first and second materials, or their alloys, can be used. Preferably, highly conductive materials such as copper, aluminum, or stainless steel can be selected. Using a single material makes material procurement and processing easier and leads to cost reduction.

[0076] In this embodiment, the conductive plate 100, consisting of the first plate 110 and the second plate 120, is configured with similar shapes and is arranged symmetrically along the Y-axis with respect to a straight line parallel to the Z-axis passing through the center of the recess 9. However, the disclosure is not limited to this embodiment, and the first plate 110 and the second plate 120 may be configured with different shapes, and they do not have to be arranged symmetrically along the Y-axis with respect to a straight line parallel to the Z-axis passing through the center of the recess 9. Furthermore, the values ​​of L1, L11, L12 and H1, H11, H12 of the first plate 110 and the second plate 120 may be different.

[0077] (b) IC module Next, the main components of the IC module 70 will be described, primarily based on Figures 1(a), 2(b), 5(a), 5(b), and 5(c). The IC module 70 is embedded in a recess 9 formed in the card base 2, and the antenna connection terminals 73a and 73b of the IC module 70 are electrically connected to the first plate 110 and the second plate 120 of the antenna 80, respectively, via a conductive adhesive layer 11. This allows the IC card 1 to form a contactless communication circuit.

[0078] Furthermore, the IC chip 74a can communicate with a contact-type reader / writer or the like through the external connection terminal 71 provided on the IC module 70.

[0079] The substrate 72 is formed by bonding copper foil to both sides of a flexible insulating resin film, such as glass epoxy resin or polyimide resin, via adhesive, and leaving the copper foil bonded to the front and back surfaces of the resin film to form a predetermined pattern. Specifically, an external connection terminal 71 is formed on one copper foil surface of the resin film, and antenna connection terminals 73a and 73b are formed on the other copper foil surface. Specifically, the process involves sequentially applying a photosensitive material to one and the other copper foil surfaces of the resin film, placing a film plate with the predetermined pattern formed on it, exposure, and etching away the non-photosensitive areas.

[0080] This results in the formation of a substrate 72 in which a predetermined pattern of copper foil remains partially on both the front and back surfaces of the resin film. In addition, the substrate 72 is pre-formed with multiple bonding holes 76, which are through holes for wire bonding to external connection terminals 71.

[0081] As shown in Figures 1(a) and 5(a), the external connection terminal 71 has defined sections for each external terminal as defined by the ISO / IEC 7816-2 standard. Specifically, as mentioned above, the external connection terminal 71 is defined as having terminal C1 (supply voltage input terminal), terminal C2 (reset signal input terminal), terminal C3 (clock signal input terminal), terminal C5 (signal ground terminal), and terminal C7 (series data input or output terminal). Terminal C6 is a standard or individually used terminal and is not normally used, while terminals C4 and C8 are reserved as unused terminals for future use. Each of these terminal areas is demarcated by an insulating groove. Specifically, the external connection terminal 71 has terminal areas of a predetermined pattern formed on one surface of an insulating substrate 72 using copper foil or the like, and the insulating groove is the area where the copper foil is interrupted and the substrate 72 is exposed.

[0082] Figure 5(b) shows the outline of the molded portion 74b with a dashed line. The outlines of the IC chip 74a, bonding holes 76, wires 75, pads 74p, and antenna connection terminals 73a and 73b, which are hidden inside the molded portion 74b, should ideally also be shown with dashed lines. However, for the sake of clarity, these are all shown with solid lines, assuming that the molded portion 74b does not exist.

[0083] The side of the IC chip 74a facing away from the substrate 72 is the circuit side, and a circuit pattern and multiple pads 74p, which are electrodes, are provided on this surface. The back surface of the external connection terminals 71 can be seen from the -Z direction through bonding holes 76 formed in the substrate 72 at locations corresponding to each section of the external connection terminals 71. In other words, the pads 74p of the IC chip 74a and the predetermined sections of the external connection terminals 71 can be made electrically connected by connecting them with a wire 75 such as a gold wire through the bonding holes 76.

[0084] In this embodiment, the IC chip 74a used in the IC module 70 is described on the premise that it is connected to each terminal by wire bonding technology. However, the IC module used in the IC card 1 of this disclosure is not limited to this type. For example, an IC module employing a flip-chip method may be used in which the side of the IC chip 74a facing the same side as the substrate 72 is the circuit side, and the pads of the IC chip 74a and the wiring pattern formed on the substrate 72 are facing each other. In the flip-chip method, the pads of the IC chip 74a and the wiring pattern formed on the substrate 72 are directly connected via metal bumps or the like without using wires.

[0085] On the side of the substrate 72 opposite to the external connection terminal 71, a pair of antenna connection terminals 73a and 73b are arranged on both the left and right sides of the IC chip 74a, forming conductive regions that are roughly T-shaped or H-shaped in plan view. The multiple antenna connection terminals 73a and 73b are electrically connected to the corresponding multiple conductive plates 100 (first plate 110 and second plate 120) on the sides of the conductive plates 100 (first plate 110 and second plate 120) that face the opening side of the recess 9 of the card base 2.

[0086] Taking Figure 5(b) as an example, multiple pads 74p of the IC chip 74a are connected to each section of the external connection terminal 71 (sections C1, C2, C3, C5, and C7, though not shown) by wires 75. In addition, the other pads 74p of the IC chip 74a are connected to the antenna connection terminals 73a and 73b by wires 75. These bonding holes 76 and wires 75 are covered and protected by the molded portion 74b. In this embodiment, seven pads 74p are provided on the IC chip 74a, but the number and arrangement are merely an example, and any number and arrangement may be used.

[0087] The IC chip body 74 is positioned on the side of the substrate 72 opposite to the surface where the external connection terminals 71 are formed. The IC chip body 74 consists of an IC chip 74a bonded and fixed to the substrate 72 via adhesive, bonding wires 75 for connection, and a molded part 74b which is a sealing resin to protect them. The IC chip 74a includes a CPU for controlling the operation of both contact and contactless communication, and a storage device such as RAM, ROM, EEPROM, or flash memory. Furthermore, the IC chip 74a includes various circuits such as an interface circuit and a power generation circuit for decoding input signals and generating output signals for contact and contactless communication. Note that these various circuits may be provided as separate elements from the IC chip 74a.

[0088] The molded portion 74b is provided as a protruding part that covers the IC chip 74a and wire 75 in order to protect them from external forces and environmental loads. A UV-curable resin or a thermosetting resin is used for the molded portion 74b.

[0089] The thickness of the IC chip body 74 depends on the thickness of the IC chip 74a inside and the shape of the bonded wires, but can be, for example, 0.45 mm or more and 0.75 mm or less. The total thickness of the IC module 70 can be, for example, 0.35 mm or more and 1.0 mm or less, preferably 0.40 mm or more and 0.65 mm or less. By being within the latter range, the maximum depth of the recess 9 can be reduced to 0.7 mm or less, and the overall thickness of the IC card 1 can be kept to 0.84 mm or less as defined in the ISO / IEC 7816-1 standard.

[0090] Electrical signals input through the external connection terminal 71 are converted into information that the IC chip 74a can interpret by the contact interface unit and input to the IC chip 74a. The IC chip 74a uses the memory while the CPU reads, writes, and performs calculations on data, and as a result of these processes, outputs some information to the contact interface unit. The contact interface unit converts this information into predetermined electrical signals directed to external devices such as contact-type reader / writers and outputs them from the external connection terminal 71. As described above, the memory consists of rewritable non-volatile memory such as EEPROM, volatile memory such as RAM for temporary storage, and non-rewritable non-volatile memory such as ROM. EEPROM may be replaced with flash memory or the like.

[0091] Furthermore, electrical signals input through the antenna 80 are converted into information that the IC chip 74a can interpret by the contactless interface unit and input to the IC chip 74a. The IC chip 74a uses memory while the CPU reads, writes, and performs calculations on data, and as a result of these processes, outputs some information to the contactless interface unit. The contactless interface unit converts this information into predetermined electrical signals directed to external devices such as contactless readers / writers and outputs them from the antenna 80.

[0092] (c) Conductive adhesive layer The following describes the conductive adhesive layer 11 used to electrically and mechanically connect the IC module 70 to the card base 2 after forming a recess 9 for embedding the IC module 70 by cutting with an end mill or the like, and then embedding and fixing the IC module 70 in the recess 9. As shown in Figure 5(c), the conductive adhesive layer 11 is a liquid or tape-like material that is placed between the first plate 110 or a second plate 120 (not shown), the substrate 72 of the IC module 70, and the antenna connection terminals 73a or 73b (not shown) formed on the substrate 72.

[0093] It is not necessary for the conductive adhesive layer 11 sandwiched between the first plate 110, the second plate 120 and the antenna connection terminals 73a and 73b, and the adhesive layer sandwiched between the IC module 70 and the card base 2 in areas where the antenna connection terminals 73a and 73b are not present, to be made of the same material. For example, the former may be made of a tape-like material and the latter of a liquid material, and the components of the conductive adhesive layers may be different. However, by making the components and composition of the conductive adhesive layers the same, the burden of material preparation and formation processes for the conductive adhesive layers can be reduced.

[0094] The conductive adhesive layer 11 may be applied or attached in advance to the side of the substrate 72 of the IC module 70 opposite to the external connection terminals 71, or it may be applied or attached to the bottom surface of the recess 9 of the card base 2 after cutting.

[0095] A typical conductive adhesive layer 11 may be applied to the entire back surface of the substrate 72 or to the portion corresponding to the first recess 91 of the recesses 9, as it also serves as the mechanical connection between the IC module 70 and the pre-cut card substrate 2. This allows the electrical connection of the IC chip 74a and the antenna 80, and the mechanical connection of the IC module 70 and the card substrate 2, to be made with the same type of conductive adhesive layer 11, contributing to the simplification of the process.

[0096] However, the conductive adhesive layer 11 may be applied and attached so as to cover only the area of ​​the antenna connection terminals 73a and 73b on the back surface of the substrate 72, and a different adhesive that does not have conductivity may be applied and attached to the rest of the back surface of the substrate 72. Since conductivity does not need to be considered for this other adhesive, it is easier to select an adhesive that is advantageous for mechanical connection.

[0097] As the conductive adhesive layer 11 that can be used for both electrical and mechanical connections, anisotropic conductive film (ACF) or anisotropic conductive paste (ACP) can be used. Alternatively, a conductive paste or solder paste in which silver particles are dispersed as a filler in epoxy resin may also be used. In particular, if ACF is used, the ACF can be heat-laminated over the entire back surface of the substrate 72 of the IC module 70, and after embedding the IC module 70 in the recess 9 of the cut card base 2, it can be heat-pressed at a predetermined temperature and load. This makes it easy to electrically connect the IC chip 74a and the antenna 80. Furthermore, since a mechanical connection of the IC module 70 to the card base 2 can be made at the same time, the mounting process of the IC module 70 to the card base 2 can be simplified.

[0098] When ACF is used as the conductive adhesive layer 11, the electrical connection between the IC chip 74a and the antenna 80, and the mechanical connection between the IC module 70 and the card base 2 can be explained as follows based on Figure 5(c). The conductive adhesive layer 11 has a structure in which conductive particles 11a, in which a metal film is formed around a spherical resin or spherical metal, are dispersed in an adhesive 11b, which is a binder containing adhesive components. The conductive particles 11a may be resin coated with nickel or gold, or they may be solder particles. Various types of solder particles can be used, such as SnPb-based, SnAgCu-based, SnCu-based, SnZnBi-based, SnAgInBi-based, SnZnAl-based, or alloys of these with other metals. These configurations are the same even when ACP is used.

[0099] Here, thermal pressure is applied to the substrate 72 from the +Z direction to the -Z direction so that the conductive adhesive layer 11, which is positioned between the first plate 110 electrically connected to the tip of the antenna wire 83, the substrate 72 of the IC module 70, and the antenna connection terminal 73a formed on the substrate 72, is compressed.

[0100] As a result, strong heat and pressure are applied to the portion of the conductive adhesive layer 11 that is particularly close together, sandwiched between the antenna holding layer 5 and the antenna connection terminal 73a. The conductive particles 11a of the conductive adhesive layer 11 in this portion are then pressed against both the first plate 110 and the antenna connection terminal 73a, which are exposed from the antenna holding layer 5, along the thickness direction of the conductive adhesive layer 11. Furthermore, if the conductive particles 11a are small, they overlap in a chain-like fashion from the first plate 110 to the antenna connection terminal 73a along the thickness direction of the conductive adhesive layer 11. In other words, electrical conductivity is established between the exposed first plate 110 and the antenna connection terminal 73a via the conductive particles 11a.

[0101] On the other hand, between the antenna holding layer 5 and the substrate 72 in the area where the antenna connection terminal 73a is absent, the conductive particles 11a are not compressed to the extent that they are pressed against the first plate 110 and the antenna connection terminal 73a along the thickness direction of the conductive adhesive layer 11, or to the extent that they overlap in a chain-like fashion. However, the adhesive force of the adhesive 11b generated by this heat and pressure mechanically connects the antenna holding layer 5 and the substrate 72. One possible explanation for the adhesive force of the adhesive 11b is the wedge effect caused by the adhesive 11b penetrating into minute irregularities on the surface of the antenna holding layer 5 and the substrate 72.

[0102] As described above, the IC module 70 has opposing antenna connection terminals 73a and 73b and the first plate 110 and second plate 120 that are electrically connected, for example, via an ACF. The ACF is positioned in a region along the outer circumference 93 of the recess 9 so as to overlap with the first recess 91 in a plan view along the Z-axis.

[0103] (d) Method of manufacturing an IC card Next, an example of a manufacturing method for the IC card 1, which is a dual-interface IC card, using the card base 2, IC module 70, and conductive adhesive layer 11 described above, will be explained mainly based on Figures 2(a), 3, and 4. Figures 3(a), 3(b), 3(c), and 4(a), 4(b), and 4(c) are diagrams that explain the manufacturing method and manufacturing process of the IC card 1, and correspond to the cross-sectional view shown in Figure 2(a).

[0104] First, typically as shown in Figure 3(a), a first plate 110 and a second plate 120, which are conductive plates 100, are bonded to one surface of the antenna retaining layer 4. The one surface of the antenna retaining layer 4 is the surface that faces the antenna retaining layer 5 when laminated. The flat surfaces of the flat portions 111 and 121 of the first plate 110 and the second plate 120 are in contact with one surface of the antenna retaining layer 4, and the displacement portions 112 and 122 are positioned approximately perpendicular to the one surface of the antenna retaining layer 4. Here, the displacement portions 112 and 122 are positioned to extend in the direction from the antenna retaining layer 4 toward the antenna retaining layer 5.

[0105] Now, let's consider the case where a conductive plate 100 is bonded to one surface of the antenna retaining layer 5. One surface of the antenna retaining layer 5 is the surface that faces the antenna retaining layer 4 when laminated. In this case, the displacement portions 112 and 122 formed at one end of the flat portions 111 and 112 of the first plate 110 and the second plate 120 are arranged to extend in a direction away from the antenna retaining layer 4 from one surface of the antenna retaining layer 5.

[0106] In other words, the displacement parts 112 and 122 are positioned to extend in a direction that sinks into the interior of the antenna retaining layer 5 from one surface of the antenna retaining layer 5. Therefore, it may be difficult to firmly adhere the displacement parts 112 and 122 to one surface of the antenna retaining layer 5. For this reason, when bonding the conductive plate 100 to one surface of the antenna retaining layer 5, it is desirable to form recesses in advance on one surface of the antenna retaining layer 5 to accommodate the displacement parts 112 and 122.

[0107] Next, as shown in Figure 3(b), a covered conductor covered with an insulating material is used as the antenna wire 83 and is embedded by a winding machine into the forming surface of the antenna holding layer 5 on which the conductive plate 100 is formed, with either the first plate 110 or the second plate 120 as the starting point and the other as the ending point. Here, at the starting and ending points of the antenna wire 83, the winding machine welds the ends of the antenna wire 83 to the first plate 110 and the second plate 120. The parts of the first plate 110 and the second plate 120 to which the ends of the antenna wire 83 are welded become the tip portions that protrude in the +Z direction of the displacement portions 112 and 122.

[0108] Typically, while applying a predetermined amount of heat and pressure to the antenna retaining layer 4, an antenna supply head is drawn in a loop shape as shown in Figure 1(a), and the antenna wires 83 supplied from the antenna supply head are sequentially embedded in the antenna retaining layer 4. At this time, the antenna retaining layer 4 may also be referred to as the first substrate. In Figure 3(b), the conductive plate 100 and the antenna wires 83 are arranged on the +Z side of the antenna retaining layer 4, but in the state shown in Figure 2(a) after lamination is complete, the antenna retaining layer 4 is laminated upside down. The antenna retaining layer 4 on which the first plate 110, the second plate 120 and the antenna wires 83 are arranged constitutes the antenna sheet 12.

[0109] Next, as shown in Figure 3(c), an antenna retaining layer 5 is prepared to face the antenna sheet 12. In Figure 3(c), holes 51 are pre-formed in the antenna retaining layer 5 to absorb the protruding portions from one side of the antenna retaining layer 4, such as the flat portions 111 and 121 and the displaced portions 112 and 122 of the first plate 110 and the second plate 120. However, this step is not essential. Alternatively, recesses may be formed instead of holes.

[0110] Next, as shown in Figure 4(a), the antenna retaining layer 5 is placed on one side of the antenna retaining layer 4. If the antenna retaining layer 5 has holes 51, it is placed on top of the first plate 110 and the second plate 120 in an aligned position so that the holes 51 fit with the protruding portions of the first plate 110 and the second plate 120. In this state, the laminate of antenna retaining layers 4 and 5 may be sandwiched between stainless steel plates and heat-pressed from above and below. This ensures that the antenna retaining layers 4 and 5 are in close contact, which prevents the internal arrangement of the first plate 110, the second plate 120, and the antenna wire 83 from shifting during subsequent processes. The antenna retaining layer 5, which is laminated on the first base material so as to sandwich the antenna 80 including the conductive plate 100 and the antenna wire 83, may be referred to as the second base material.

[0111] In this embodiment, the intermediate stage described above is omitted. Instead, as shown in Figure 4(b), the oversheet layer 8, core layers 7 and 6, antenna holding layers 5 and 4, and oversheet layer 3 are stacked in this order from the bottom in the thickness direction. That is, the laminate with antenna holding layers 4 and 5 stacked as shown in Figure 4(a) is inverted, and the necessary base materials are added and stacked on top of and below it. After that, the laminate of large sheets with cards arranged in multiple directions is sandwiched between stainless steel plates from above and below in the thickness direction, and heat pressure is applied to the laminate through the stainless steel plates.

[0112] By going through this hot pressing process, a large-format sheet-type card base can be obtained in which each layer of the laminate, including the first and second substrates, is integrated. Furthermore, if any of the oversheet layer, core layer, or antenna holding layer has heat resistance that prevents heat fusion at a predetermined temperature, an adhesive sheet that heats together at a predetermined temperature is sandwiched between each layer, or an adhesive is applied. Then, by subjecting these to a hot pressing process, an integrated large-format sheet-type card base can be obtained.

[0113] The large sheet of card base material obtained as described above, in which cards are arranged in multiple rows vertically and horizontally, is punched out using a punching machine as card base material 2 with a card size of ISO / IEC 7816-1. Next, as shown in Figure 4(c), recesses 9 for embedding the IC module 70 are formed in the card base material 2 by cutting with an end mill. This gives the cut card base material 2. The recesses 9 for embedding the IC module 70 in the card base material 2 are formed on the surface of the card base material 2 on the side where the opening of the recess 9 is closer to the first substrate than to the second substrate.

[0114] As shown in Figures 2(a) and 2(b), the recess 9 is composed of two stages: a first recess 91 with a first depth for housing the flat substrate 72 of the IC module 70, and a second recess 92 with a second depth that is deeper than the first recess 91 for housing the convex IC chip body 74.

[0115] Typically, the machining sequence for the recess 9 involves first cutting the entire surface of the recess 9 to create a first recess 91 with a first depth. Then, a second recess 92 with a second depth and a slightly smaller area is additionally cut near the center of the roughly rectangular first recess 91. This creates a two-tiered recess 9. Furthermore, the surfaces of the first plate 110 and the second plate 120 are exposed on the bottom surface of the first recess 91 of the card base 2.

[0116] On the other hand, separate from the manufacturing of the card base 2 and the cutting process to form the recess 9, the conductive adhesive layer 11 is attached to the IC module 70. As the IC module 70, a module tape is used in which the IC module 70 is formed continuously on a long tape, usually in one or two rows. The tape-shaped ACF is attached to the side of this module tape opposite to the side where the external connection terminals 71 are formed, while applying a certain amount of heat and pressure. Then, the module tape with the ACF attached is punched out with a punching machine as a roughly rectangular IC module 70 with rounded corners, thereby obtaining an IC module 70 with the conductive adhesive layer 11 attached.

[0117] Subsequently, the IC module 70, to which the conductive adhesive layer 11 is attached, is embedded in the card base 2 in which the recess 9 is formed. A predetermined heat block is pressed against the external connection terminal 71, and predetermined heat and pressure are applied toward the card base 2 for a predetermined time. By melting the conductive adhesive layer 11, which is made of ACF, an electrical connection is made between the antenna connection terminals 73a and 73b of the IC module 70 and the first plate 110 and the second plate 120.

[0118] Along with this, a mechanical connection is made between the IC module 70 and the card base 2. Although the time and thermal pressure conditions applied to the ACF vary depending on its type and composition, as an example, the time can be 0.5 seconds or more and 10.0 seconds or less, the temperature 150°C or more and 250°C or less, and the pressure 20 MPa or more and 100 MPa or less. By going through this series of processes, an IC card 1 as shown in Figure 2(a) can be manufactured.

[0119] (e) IC card of the embodiment relating to this disclosure The manufacturing process for IC card 1, a dual-interface IC card capable of contact and contactless communication with external devices, is summarized as follows: Multiple conductive plates 100 are bonded to the antenna holding layer 4, which is the first substrate. Then, while welding the antenna wire 83 to the multiple conductive plates 100 and applying heat and pressure, an antenna 80 is embedded in the first substrate, with both ends of the antenna wire 83 electrically connected to the multiple conductive plates 100, forming an antenna 80 on one side of the first substrate. This is called the antenna formation process.

[0120] Next, the second substrate, exemplified by the antenna holding layer 5, and other necessary substrates are laminated on the first substrate on which the antenna 80 is formed, sandwiching the antenna 80. This is called the lamination process. Next, the laminate formed by laminating the first substrate, the second substrate, and other necessary substrates is punched out into a card-sized card base. This is called the punching process. Furthermore, a recess 9 for embedding the IC module 70 is formed in the card base 2, on the surface of the card base 2 on the side where the opening of the recess 9 is closer to the first substrate than to the second substrate. This is called the recess formation process.

[0121] On the other hand, an IC module 70 is prepared, comprising a substrate 72, an IC chip 74a and a plurality of antenna connection terminals 73a, 73b electrically connected to the IC chip 74a, and an external connection terminal 71 electrically connected to the IC chip 74a and exposed on the side of the card base 2 where the recess 9 is formed. This is referred to as the IC module preparation step. The IC chip 74a and the plurality of antenna connection terminals 73a, 73b are arranged on one side of the substrate 72. The external connection terminal 71 is arranged on the other side of the substrate 72.

[0122] Next, the multiple antenna connection terminals 73a, 73b and the multiple conductive plates 100, which face each other, are electrically connected via the conductive adhesive layer 11 so that the IC chip 74a and the antenna 80 constitute a contactless communication circuit. This is called the antenna connection process. The IC module 70 is then bonded to the recess 9 of the card base 2. This is called the IC module bonding process. Typically, the antenna connection process and the IC module bonding process are carried out simultaneously or in a single step.

[0123] Here, in a cross-sectional view including the thickness direction and the long side direction of the card base 2, the end on the opening side of the recess 9 of the conductive plate 100 along the thickness direction is defined as the upper end, and the end opposite to the upper end is defined as the lower end. Furthermore, the point where the upper end of the conductive plate 100 is electrically connected to the antenna connection terminals 73a and 73b is defined as the first point P1. Furthermore, the point where the lower end of the conductive plate 100 is electrically connected to the antenna wire 83 is defined as the second point P2. At this time, the position of the lower end of the conductive plate 100 corresponding to the second point P2 is displaced downward (towards the -Z direction) compared to the position of the lower end corresponding to the first point P1.

[0124] By having the above configuration, the IC card 1 can achieve the following without increasing the overall thickness of the conductive plate 100 unnecessarily: the first point P1 where the conductive plate 100 and the antenna connection terminals 73a and 73b are electrically connected can be positioned higher, and the second point P2 where the conductive plate 100 and the antenna wire 83 are electrically connected can be positioned lower. This suppresses thermal deformation of the surrounding substrate during electrical connection between the conductive plate 100 and the antenna connection terminals 73a and 73b of the IC module 70, which would occur if the overall thickness of the conductive plate 100 were increased.

[0125] Furthermore, in the conductive plate 100, the lower end corresponding to the second point P2 is displaced lower than the lower end corresponding to the first point P1. This reduces the thickness and volume of the conductive adhesive layer 11 used for the electrical connection between the IC module 70 and the conductive plate 100, thereby suppressing a decrease in the reliability of the electrical connection between the IC module and the antenna due to the destruction of the conductive adhesive layer 11. Moreover, since the electrical connection point between the conductive plate 100 and the antenna wire 83 can be displaced near the center in the thickness direction of the card base 2, the risk of the antenna wire 83 detaching from the conductive plate 100 due to external forces such as bending, or the risk of the antenna wire 83 breaking, can be reduced. As a result, this embodiment provides a dual-interface IC card and a method for manufacturing the same that can improve the reliability of the electrical connection between the IC module and the antenna.

[0126] 2. Modified examples of embodiments of this disclosure Next, modifications of the embodiment of the IC card of the present disclosure will be described. In the embodiment described above, in a cross-sectional view including the thickness direction and the long side direction of the card base 2, the conductive plate 100 has a flat portion and a displacement portion with the following configuration. That is, the flat portion is a relatively thin flat plate that extends along the long side direction of the card base 2 to a surface along the main surface direction of the card base 2. The displacement portion 112 is configured such that its thickness increases downwards as it moves away from the center of the recess 9 provided in the card base 2 relative to the flat portion 111, the lower end of the displacement portion 112 is displaced downwards from the lower end of the flat portion 111. However, the embodiment of the present disclosure is not limited thereto, and various modifications are permitted.

[0127] (a) Variation 1 Figure 6(a) is a diagram corresponding to Figure 2(c), showing the cross-sectional configuration of the first plate 110a as an example of a conductive plate according to Modification 1 of the embodiment of this disclosure. Unlike the configuration of the embodiment described above, the first plate 110a is not configured such that the thickness of the displacement portion 112a increases downward so that the lower end of the flat portion 111a is displaced further downward. The displacement portion 112a is formed by bending one end on the -X direction side of a plate material of the same thickness as the flat portion 111a so as to overlap the flat portion 111a and be positioned parallel to the flat portion 111a.

[0128] In other words, the displacement portion 112a is formed by first bending one end of a plate material of the same thickness as the flat portion 111a on the -X side at approximately a right angle toward the -Z direction, and then bending it at approximately a right angle toward the +X direction along the X axis so that it is approximately parallel to the flat portion 111b. The bending point avoids the second point P2, that is, the point where the first plate 110a and the antenna wire 83 are electrically connected.

[0129] In other words, in the first plate 110a, in a cross-sectional view including the thickness direction and the long side direction of the card base 2, the first plate 110a of a predetermined thickness is bent in a region other than the second point P2. At this time, the position of the lower end of the first plate 110a corresponding to the second point P2 is displaced downwards from the position of the lower end corresponding to the first point P1.

[0130] As shown in this modified example, by partially bending a plate of the same thickness and arranging a displacement portion 112a that is bent downwards and approximately parallel to the flat portion 111a, the material of the conductive plate can be standardized, making material procurement easier and reducing costs. In addition, although the displacement portion 112 in the embodiment has a larger heat capacity than the flat portion 111 due to its increased thickness, in this modified example, as shown in Figure 6(a), the displacement portion 112a has a roughly C-shaped cross-section, and the increase in heat capacity can be suppressed by providing an internal void. Therefore, thermal deformation of the surrounding substrate during electrical connection between the conductive plate and the antenna connection terminal of the IC module, which occurs when the heat capacity of the conductive plate increases, can be further suppressed.

[0131] In this modified example, the lateral length of the flat portion 111a in cross-sectional view can be expressed as L11, and the thickness of the flat portion 111a can be expressed as H11. Similarly, the lateral length of the displacement portion 112a in cross-sectional view can be expressed as L12, and the thickness of the displacement portion 112a can be expressed as H12. Furthermore, the lateral length of the entire first plate 110a in cross-sectional view can be expressed as L1, and its thickness can be expressed as H1. The preferred range for these dimensions is the same as the range shown for the first plate 110 in the embodiment. Although this modified example has only described the first plate 110a, it goes without saying that the same can be applied to the configuration of the second plate. This also applies to subsequent modified examples.

[0132] (b) Variation 2 Next, a conductive plate of modified example 2 according to this embodiment will be described. Figure 6(b) is a diagram corresponding to Figure 2(c), showing the cross-sectional configuration of the first plate 110b as an example of the conductive plate of modified example 2. The first plate 110b is similar to modified example 1 described above, and the displacement portion 112b is formed by bending one end on the -X side of a plate material of the same thickness as the flat portion 111b. However, the way it is bent is different from modified example 1. In modified example 2, the displacement portion 112b is formed by first bending one end on the -X side of a plate material of the same thickness as the flat portion 111b at approximately a right angle to the -Z side, then bending it at approximately a right angle to the -X side along the X axis so that it is approximately parallel to the flat portion 111b, and then bending it at approximately a right angle to the +Z side.

[0133] In other words, the first plate 110b has a displaced portion 112b that is bent so that one end of the flat portion 111b on the -X side has an upward opening, forming a roughly C-shape or U-shape. In this modified example, the bending points avoid the second point P2, i.e., the point where the first plate 110b and the antenna wire 83 are electrically connected. As a result, with respect to the first plate 110b, in a cross-sectional view including the thickness direction and the long side direction of the card base 2, the first plate 110b of a predetermined thickness is bent in a region other than the second point P2. As a result, the lower end of the first plate 110b corresponding to the second point P2 is displaced lower than the lower end corresponding to the first point P1.

[0134] In this modified version, as in Modified Version 1, the material of the conductive plate can be standardized, making material procurement easier and reducing costs. Furthermore, the displacement section 112b has a roughly C-shaped cross-section, and by providing an internal void, the increase in heat capacity can be suppressed. As a result, thermal deformation of the surrounding substrate during electrical connection between the conductive plate and the antenna connection terminal of the IC module, which occurs when the heat capacity of the conductive plate increases, can be further suppressed.

[0135] In this modified example, the lateral length of the flat portion 111b in cross-sectional view can be expressed as L11, and the thickness of the flat portion 111b can be expressed as H11. Similarly, the lateral length of the displacement portion 112b in cross-sectional view can be expressed as L12, and the thickness of the displacement portion 112b can be expressed as H12. Furthermore, the lateral length of the entire first plate 110b in cross-sectional view can be expressed as L1, and its thickness can be expressed as H1. The preferred ranges for these dimensions are the same as those shown for the first plate 110 according to the embodiment.

[0136] (c) Modification 3 Next, a conductive plate of modified example 3 according to this embodiment will be described. Figure 6(c) is a diagram corresponding to Figure 2(c) showing the cross-sectional configuration of the first plate 110c as an example of the conductive plate of modified example 3. The first plate 110c is similar to modified examples 1 and 2 described above, and the displacement portion 112c is formed by bending one end on the -X side of a plate material of the same thickness as the flat portion 111c. However, the way it is bent is different from modified examples 1 and 2. In modified example 3, the displacement portion 112c is formed by first bending one end on the -X side of a plate material of the same thickness as the flat portion 111c diagonally toward the -Z and -X directions, and then bending it diagonally toward the -X direction along the X axis so that it is substantially parallel to the flat portion 111c.

[0137] In other words, the first plate 110c is bent so that one end of the flat portion 111c on the -X direction side has two diagonal bends so that it is roughly S-shaped or roughly Z-shaped, and has a displacement portion 112c that is roughly parallel to the flat portion 111c. In this modified example, the diagonally positioned portion is described as the inclined portion 113, but the inclined portion 113 and the portion roughly parallel to the flat portion 111c may be collectively called the displacement portion 112c. Also, although the inclined portion 113 is described as being positioned diagonally, the inclined portion 113 may be positioned in a direction roughly perpendicular to the flat portion 111c and the displacement portion 112c.

[0138] In this modified example, the bending point avoids the second point P2, that is, the point where the first plate 110c and the antenna wire 83 are electrically connected. As a result, with respect to the first plate 110c, in a cross-sectional view including the thickness direction and the long side direction of the card base 2, the first plate 110c of a predetermined thickness is bent in a region other than the second point P2. As a result, the position of the lower end of the first plate 110c corresponding to the second point P2 is displaced lower than the position of the lower end corresponding to the first point P1.

[0139] In this modified example, as in Modification Example 1, the material of the conductive plate can be standardized, making material procurement easier and reducing costs. Furthermore, the overall cross-sectional shape of the first plate 110c, including the flat portion 111c and the displacement portion 112c, becomes roughly S-shaped or roughly Z-shaped, which keeps the volume small and suppresses the increase in heat capacity. As a result, thermal deformation of the surrounding substrate during electrical connection between the conductive plate and the antenna connection terminal of the IC module, which occurs when the heat capacity of the conductive plate increases, can be further suppressed.

[0140] In this modified example, the lateral length of the flat portion 111c in cross-sectional view can be expressed as L11, and the thickness of the flat portion 111c can be expressed as H11. Similarly, the lateral length of the displacement portion 112c in cross-sectional view can be expressed as L12, and the thickness of the displacement portion 112c can be expressed as H12. Furthermore, the lateral length of the entire first plate 110c in cross-sectional view can be expressed as L1, and its thickness can be expressed as H1. The preferred ranges for these dimensions are the same as those shown for the first plate 110 according to the embodiment.

[0141] In addition, as a configuration common to this embodiment and its variations, it is preferable that the conductive plate is arranged along the long side direction at the first and second points in a cross-sectional view including the thickness direction and the long side direction of the card base. That is, it is preferable that the upper end of the flat portion and the lower end of the displacement portion are both substantially parallel to the long side direction of the card base 2. With this configuration, the electrical connection between the conductive plate and the antenna connection terminal is made more stable, and the electrical connection between the conductive plate and the antenna wire is made more stable.

[0142] Furthermore, as a configuration common to the modified examples of this embodiment, it is preferable that the first plate and the second plate constituting the conductive plate are arranged symmetrically with respect to the Z axis in a cross-sectional view including the thickness direction and the long side direction of the card base. This is expected to ensure that the first plate and the second plate have uniform durability and connection reliability against external loads such as bending of the card. [Explanation of symbols]

[0143] 1 IC card 2 card bases 3.8 Oversheet layer 4, 5 Antenna holding layer 6, 7 Core Layers 9 recesses 11. Conductive adhesive layer 11a Conductive particles 11b Adhesive 12 Antenna Sheets 51 holes 70 IC modules 71 External connection terminals 72 circuit boards 73a, 73b Antenna connection terminals 74 IC chip units 74a IC chip 74b Molding section 74p pad 75 wires 76 Bonding Holes 80 Antenna 83 Antenna wire 91 First recess 91a Bottom 92 Second recess 93 Outer circumference 93a, 93b sides 100 conductive plates 110, 110a, 110b, 110c First Plate 111, 111a, 111b, 111c flat part 112, 112a, 112b, 112c Displacement section 113 Slope 120 Second Plate

Claims

1. A dual-interface IC card capable of contact and contactless communication with external devices, A card base with a recess, An IC module embedded in the aforementioned recess, The card base comprises an antenna disposed inside the card base, The IC module comprises a substrate, an IC chip disposed on one side of the substrate and a plurality of antenna connection terminals electrically connected to the IC chip, and an external connection terminal disposed on the other side of the substrate, electrically connected to the IC chip and exposed on the side of the card base where the recess is formed. The antenna comprises an antenna wire and a plurality of conductive plates positioned at the end of the antenna wire and electrically connected to the antenna wire. The plurality of antenna connection terminals and the plurality of conductive plates are electrically connected by a conductive adhesive layer, thereby the IC chip and the antenna constitute a contactless communication circuit. A dual-interface IC card in which, in a cross-sectional view of the card base including the thickness direction and the long side direction, the end of the recess of the conductive plate along the thickness direction is defined as the upper end, the end opposite to the upper end is defined as the lower end, the point where the upper end of the conductive plate is electrically connected to the antenna connection terminal is defined as the first point, and the point where the lower end of the conductive plate is electrically connected to the antenna wire is defined as the second point, the position of the lower end of the conductive plate corresponding to the second point is displaced lower than the position of the lower end corresponding to the first point.

2. The dual interface IC card according to claim 1, wherein, in a cross-sectional view of the card base including the thickness direction and the long side direction, when the thickness of the conductive plate at the first point is defined as the first thickness and the thickness of the conductive plate at the second point is defined as the second thickness, the position of the lower end of the conductive plate corresponding to the second point is displaced downward from the position of the lower end corresponding to the first point because the second thickness is greater than the first thickness.

3. The dual interface IC card according to claim 1, wherein, in a cross-sectional view of the card base including the thickness direction and the long side direction, the conductive plate of a predetermined thickness is bent in a region other than the second point, so that the position of the lower end of the conductive plate corresponding to the second point is displaced downward from the position of the lower end corresponding to the first point.

4. The dual interface IC card according to claim 3, wherein, in a cross-sectional view including the thickness direction and the long side direction of the card base, the conductive plate is arranged along the long side direction at the first and second points.

5. The plurality of conductive plates are composed of a first plate and a second plate, The dual interface IC card according to any one of claims 1 to 4, wherein in a cross-sectional view including the thickness direction and the long side direction of the card base, the first plate and the second plate are arranged symmetrically with respect to the thickness direction.

6. A method for manufacturing a dual-interface IC card that enables contact and contactless communication with external devices, An antenna forming step is to bond a plurality of conductive plates to a first substrate, and then embed an antenna wire into the first substrate while welding it to the plurality of conductive plates and applying heat and pressure, thereby forming an antenna on one side of the first substrate in which both ends of the antenna wire are electrically connected to the plurality of conductive plates. A lamination step of laminating a second substrate onto the first substrate on which the antenna is formed, such that the second substrate sandwiches the antenna, A punching step in which a laminate in which the first substrate and the second substrate are at least laminated is punched out onto a card-sized card base, A recess forming step is to form a recess in the card base for embedding an IC module on the surface of the card base on the side where the opening of the recess is closer to the first substrate than to the second substrate, An IC module preparation step of preparing an IC module comprising a substrate, an IC chip disposed on one side of the substrate and a plurality of antenna connection terminals electrically connected to the IC chip, and an external connection terminal disposed on the other side of the substrate, electrically connected to the IC chip and exposed on the side of the card base where the recess is formed, An antenna connection step involves electrically connecting a plurality of antenna connection terminals and a plurality of conductive plates facing each other via a conductive adhesive layer, such that the IC chip and the antenna constitute a contactless communication circuit. The process includes an IC module bonding step of bonding the IC module to the recess of the card base, A method for manufacturing a dual-interface IC card, wherein, in a cross-sectional view of the card base including the thickness direction and the long side direction, the end of the conductive plate on the opening side of the recess along the thickness direction is defined as the upper end, the end opposite to the upper end is defined as the lower end, the point where the upper end of the conductive plate is electrically connected to the antenna connection terminal is defined as the first point, and the point where the lower end of the conductive plate is electrically connected to the antenna wire is defined as the second point, the position of the lower end of the conductive plate corresponding to the second point is displaced lower than the position of the lower end corresponding to the first point.

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