IC card and method for manufacturing the same

Abstract

This invention provides a dual-interface IC card and a method for manufacturing the same, which suppress deformation of the conductive plate and improve electrical connection reliability. [Solution] The IC card 1 comprises a card base 2 with a recess 9, an IC module 70, and an antenna 80. The IC module 70 comprises a substrate 72, an IC chip, an antenna connection terminal 73a, and an external connection terminal 71. The antenna 80 comprises an antenna wire 83 and a conductive plate 100. Multiple antenna connection terminals 73a and multiple conductive plates 100 are electrically connected, and the IC chip and antenna 80 constitute a contactless communication circuit. In a cross-sectional view, with respect to a first point P1 where the upper end of the conductive plate 100 is connected to the antenna connection terminal 73a, and a second point P2 where the lower end of the conductive plate 100 is connected to the antenna wire 83, the upper end of the conductive plate 100 corresponding to the second point is displaced upward from the upper end corresponding to the first point, with the side surface 91b of the recess 9 as the boundary.

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 through 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 for entering and leaving a room or for ticket gates at stations. Therefore, the dual interface IC card is also becoming more popular in the market.

[0003] By the way, the manufacturing of the dual interface IC card is performed as follows. First, as described in Patent Document 1, a card substrate 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 substrate. Then, the IC module is embedded in the embedding planned area. Here, a conductive wire is arranged on one of the one or more core sheets, and the conductive wire forms a winding antenna portion for providing a non-contact communication function and a contact terminal portion that is in electrical contact with the terminals of the IC module, and the contact terminal portion 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] Here, the thickness direction of the card is defined as the Z-axis direction, the long side direction as the X-axis direction, and the short side direction as the Y-axis direction. Let the lengths of the cross-section of the card cut by planes parallel to the Z-axis and Y-axis be h and b, respectively. 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 extending along the long side direction (X-axis direction), and calculating the moment M acting on the beam with Young's modulus E and the second moment of area I, we get M=EI and 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.

[0008] 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. For this reason, the welded portion where the antenna coil 3 is welded to the lower surface of the metal plate 4 is relatively close to the center in the thickness direction of the card, so the effect of the bending stress when the card is bent can be kept small regardless of the thickness of the metal plate 4. On the other hand, the joining member 12 placed on the upper surface of the metal plate 4 is far from the center in the thickness direction of the card, so the effect of the bending stress when the card is bent is large.

[0009] Here, if the thickness of the metal plate 4 is thick, the rigidity of the metal plate 4 will increase, and when the card is bent, stress will concentrate at the interface between the metal plate 4 and the joining member 12, which may cause the joining member 12 to break or peel off from the metal plate 4. Furthermore, the heat capacity of the metal plate 4 will increase, which may make the card base material more susceptible to thermal deformation due to the heat generated when the laminate of the card base material is heat-pressed or when the joining member 12 is connected.

[0010] Therefore, in order to reduce (disperse) the bending stress at the connection between the metal plate 4 and the joining member 12 and to suppress thermal deformation of the card base material, it is necessary to make the metal plate 4 as thin as possible. However, such metal plates 4 are usually formed by punching, and the thinner the metal plate, the more easily the punched metal plate deforms due to the external force during punching. [Prior art documents] [Patent Documents]

[0011] [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]

[0012] 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 while suppressing deformation of the conductive plate. [Means for solving the problem]

[0013] 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, wherein 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, and the plurality of antennas The antenna connection terminal and the plurality of conductive plates are electrically connected by a conductive adhesive layer, thereby forming 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 conductive plate on the opening side of the recess 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 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 upper end of the conductive plate corresponding to the second point is displaced upward from the position of the upper end corresponding to the first point, with the side surface of the recess as the boundary.

[0014] Furthermore, in a dual-interface IC card relating to a second configuration according to another form of this implementation, with respect to the first configuration, the position of the lower end corresponding to the second point and the position of the lower end corresponding to the first point may be aligned along the long side direction in the conductive plate.

[0015] Furthermore, in a dual-interface IC card relating to a third configuration according to another form of this embodiment, in the first or second configuration, 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.

[0016] A method for manufacturing a dual-interface IC card capable of contact and contactless communication with external devices, according to a fourth 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 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, with both ends of the antenna wire 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 on the surface of the card base for embedding an IC module; a substrate, an IC chip and a plurality of antenna connection terminals electrically connected to the IC chip disposed on one side of the substrate, and a terminal disposed on the other side of the substrate, electrically connected to the IC chip, forming the recess in the card base. The recess forming process includes an IC module preparation step of preparing an IC module having external connection terminals exposed on the surface side, 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 conductive plate is cut in the recess forming step such that the position of the upper end corresponding to the second point is displaced above the position of the upper end corresponding to the first point, with the side surface of the recess as the boundary. [Effects of the Invention]

[0017] According to the present embodiment, it is possible to provide a dual interface IC card and a manufacturing method thereof that can improve the reliability of electrical connection between an IC module and an antenna while suppressing deformation of a conductive plate.

Brief Description of Drawings

[0018] [Figure 1] It 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] It 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] It is a cross-sectional view corresponding to FIG. 2(a) for explaining a manufacturing method of a dual interface IC card according to an embodiment of the present disclosure. [Figure 4] It is a cross-sectional view corresponding to FIG. 2(a) for explaining a manufacturing method of a dual interface IC card according to an embodiment of the present disclosure. [Figure 5] It is a view of an IC module seen from the front and back respectively and an enlarged view of part C of FIG. 2(b).

Embodiments for Carrying Out the Invention

[0019] 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.

[0020] Note that the figures shown below are schematic. Therefore, the sizes and shapes of each part are exaggerated as appropriate for easy understanding. Also, in each figure, the hatching indicating the cross-section of the member is omitted as appropriate. The numerical values such as the dimensions of each member described in this specification and the material names are examples as an embodiment, and are not limited thereto, and can be appropriately selected and used. In this specification, terms specifying shapes and geometric conditions, such as terms like parallel, orthogonal, perpendicular, etc., shall include not only the strictly defined meaning but also substantially the same state.

[0021] 1. Embodiments according to the present disclosure An example of an embodiment of the IC card according to the present disclosure will be described. The IC card 1 according to the embodiment of the present disclosure is a dual interface IC card. Here, for convenience of explanation, an XYZ coordinate system is set for the IC card 1. First, as shown in FIGS. 1(a), 2(a), and 2(b), the Z-axis is taken in the normal direction of the main surface of the IC card 1. Then, from the main surface on the side where the external connection terminal 71 of the IC module 70 is not arranged, the direction from the main surface on the side where the external connection terminal 71 is arranged is taken as the +Z direction or the upper direction in the thickness direction, and the opposite direction is taken as the -Z direction or the lower direction in the thickness direction.

[0022] Also, when the IC card 1 is viewed from the +Z direction, the X-axis is a straight line perpendicular to both short sides of the IC card 1 and the Z-axis. Also, the direction from one short side closer to the external connection terminal 71 to the other short side is taken as the +X direction or the right direction, and the opposite direction is taken as the -X direction or the left direction. Further, an axis perpendicular to the X-axis and the Z-axis is taken as the Y-axis, and the direction from one long side farther from the external connection terminal 71 to the other long side is taken as the +Y direction or the upper direction, and the opposite direction is taken as the -Y direction or the lower direction.

[0023] 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).

[0024] 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).

[0025] 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.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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 flat portion 111 that is a relatively thin flat plate extending along the long side direction of the card base 2 to 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 whose thickness increases upward in the portion that moves away from the recess 9 in the long side direction with the side surface 91b of the recess 9 as the boundary, such that its upper end is displaced upward from the upper end of the flat portion 111.

[0032] 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 on the opposite side of 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 P1 shown by the dashed line in Figure 2(b), and the second point refers to P2 shown by the dashed line.

[0033] In this case, the upper end of the first plate 110 corresponding to the second point P2 is displaced upwards from the upper end of the first point P1, with the side surface 91b of the recess 9 as the boundary. In other words, when comparing the upper end positions of the first plate 110, the upper end of the second point P2 is displaced further upwards than the upper end of the first point P1 (the upper end along the Z-axis direction passing through the first point P1), as the first plate 110 is configured to be displaced upwards.

[0034] In this embodiment, the thickness of the first plate 110 along its long side is greater on the side further 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 upward. 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. In Figure 1(b), the second plate 120 is shown with a flat portion 121 and a displacement portion 122 similar to those of the first plate 110.

[0035] 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 upper end of the conductive plate 100 corresponding to the second point P2 is displaced upwards compared to the upper end corresponding to the first point P1.

[0036] The IC card 1 of this embodiment, by comprising a conductive plate 100 having the above configuration, can achieve the following. First, in order to obtain a conductive plate 100 with such a configuration, a metal plate of uniform thickness is initially embedded as a conductive plate preparation 100a in a predetermined position in the card base 2. Then, in the process of forming a recess 9 in the card base 2, the conductive plate preparation 100a is cut in accordance with the cutting process of the recess 9 so that it has the flat portion and displacement portion described above, thereby obtaining the desired conductive plate 100. As a result of this manufacturing process, the conductive plate 100 can have a flat portion and a displacement portion arranged with the side surface 91b of the recess 9 as the boundary.

[0037] Therefore, according to this disclosure, a relatively thick metal plate can be used to form the conductive plate 100, making it relatively easy to obtain materials and suppressing the risk of deformation of the conductive plate due to punching or other processes. Furthermore, since the conductive plate 100 having the desired flat portion and displacement portion can be cut in conjunction with the cutting of the recess 9, a conductive plate 100 with a thin flat portion can be processed without increasing the number of processes. As a result, stress distribution can be achieved by allowing a part of the conductive plate 100 to follow bending stress such as bending of the card, and in particular, material breakage and peeling of the conductive adhesive layer can be suppressed. Thus, 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 the IC module and the antenna.

[0038] The configuration of the IC card 1 of this embodiment and the details of its manufacturing method are described below.

[0039] (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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] (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.

[0045] (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.

[0046] (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.

[0047] 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.

[0048] (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. Details of the method for forming the antenna 80 on the antenna holding layer 4 or 5 will be described later, but an overview will be given below.

[0049] First, as shown in Figure 3(a), the first plate preparation 110a and the second plate preparation 120a, which are the base materials for 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 before lamination by applying heat and pressure. The first plate preparation 110a and the second plate preparation 120a, which are conductive plate preparation 100a, are conductive plates of approximately the same thickness throughout, and are intermediate members that will be partially cut away to become the first plate 110 and the second plate 120 during the subsequent cutting process of the recess 9.

[0050] At this time, adhesive may be applied to the surface of the antenna holding layer 4 before placing the first plate preparation 110a and the second plate preparation 120a. The first plate preparation 110a and the second plate preparation 120a are arranged side by side in the left-right direction at the planned mounting position of the IC module 70, with a portion of them overlapping with the antenna connection terminals 73a and 73b of the IC module 70 when mounted.

[0051] Here, the cross-sectional shapes of the first plate 110 and the second plate 120, which are formed by appropriately cutting the first plate preparation 110a and the second plate preparation 120a after machining the recess 9, are as shown in Figure 4(c), for example. A magnified view of the first plate 110 is shown in Figure 2(b). Thus, in the first plate preparation 110a, the area that overlaps with the recess 9 (first recess 91) in a plan view from the Z-axis direction is the area that becomes a flat portion 111 after additional machining, and the area that does not overlap with the recess 9 (first recess 91) is the area that becomes a displaced portion 112 without additional machining.

[0052] This also applies to the second plate preparation 120a, where the area overlapping with the recess 9 (first recess 91) in a plan view from the Z-axis direction is the area that becomes the flat portion 121 after additional cutting, and the area that does not overlap with the recess 9 (first recess 91) is the area that becomes the displaced portion 122 without additional cutting. In other words, the first plate preparation 110a and the second plate preparation 120a are attached to the antenna holding layer 4 by selecting a position that spans both the area overlapping with the recess 9 (first recess 91) and the area that does not overlap, in a plan view from the Z-axis direction. Note that in both the first plate preparation 110a and the second plate preparation 120a, the area overlapping with the second recess 92 in a plan view from the Z-axis direction is completely cut when the recess 9 is cut.

[0053] Now, let's return to the stage before cutting the recess 9, which is after the placement of the first plate preparation 110a and the second plate preparation 120a on the antenna holding layer 4. Next, as shown in Figure 3(b), the tip of the antenna wire 83 is welded to either the tip of the first plate preparation 110a or the tip of the second plate preparation 120a. 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 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 preparation 110a or the second plate preparation 120a, using the cut tip as the endpoint.

[0054] The starting and ending ends of the antenna wire 83 are electrically connected by welding to either the first plate preparation 110a or the second plate preparation 120a, respectively. In this way, an antenna holding layer 4 (antenna sheet 12) on which the antenna 80 is 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 commercial 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.

[0055] (v) antenna In the antenna 80 formed on the antenna holding layer 4, a pair of first plate preparations 110a and second plate preparations 120a, to which multiple ends of the antenna wires 83 are electrically connected, then undergo the lamination process of antenna holding layers 4 and 5 as shown in Figure 4(a). Furthermore, through the lamination process of the other layers shown in Figure 4(b), a large laminate is formed by laminating multiple layers. Moreover, as described above, the first plate preparation 110a and second plate preparation 120a are cut in conjunction with the cutting of the recess 9, as shown in Figure 4(c), to obtain the conductive plate 100, which is the first plate 110 and second plate 120.

[0056] The first plate 110 and the second plate 120, which are conductive plates 100, are electrically connected to the antenna connection terminals 73a and 73b of the IC module 70, respectively. The above description may be replaced with an antenna holding layer 5 instead of an antenna holding layer 4. 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.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] (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.

[0061] 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 upward (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.

[0062] 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. Furthermore, the first plate and the second plate are each composed of a relatively thin flat portion 111 and a relatively thick displacement portion 112, resulting in a cross-sectional shape that is approximately L-shaped or approximately inverted L-shaped.

[0063] As described above, the conductive plate 100 is formed by embedding a thick conductive plate, which originally has a uniform thickness throughout, into a predetermined position on the card base 2, and then cutting it in accordance with the cutting process of the recess 9 to form the flat portions 111, 121 and the displaced portions 112, 122. The original conductive plate, which has a uniform thickness throughout, is the first plate preparation 110a and the second plate preparation 120a. The areas that are thinned by cutting during the cutting of the recess 9 become the flat portions 111 and 121, and the areas that remain uncut become the displaced portions 112 and 122.

[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. In this case, the position of the upper end of the first plate 110 corresponding to the second point P2 is displaced upward (towards the +Z direction) compared to the position of the upper end corresponding to the first point P1.

[0065] In this embodiment, the upward displacement of the upper end position corresponding to the second point P2 relative to the upper 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, the lower end of the displacement portion 112 is substantially flush with the lower end of the flat portion 111, and the upper end of the displacement portion 112 protrudes upward from the upper 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 that extends from slightly to the left of the center toward the right along the X-axis is the flat portion 111. The +Z side surface of the flat portion 111 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] In a cross-sectional view, the lateral length of the flat portion 111 can be expressed as L11, and the thickness of the flat portion 111 can be expressed as H11. Similarly, in a cross-sectional view, the lateral length of the displacement portion 112 can be expressed as L12, and the thickness of the displacement portion 112 can be expressed as H1. The difference in thickness between the displacement portion 112 and the flat portion 111 can be expressed as H12 = H1 - H11. Furthermore, in a cross-sectional view, the lateral length of the entire first plate 110 can be expressed as L1, and its thickness can be expressed as H1.

[0068] These dimensions can be any values, but for example, L1 is preferably 4 mm or more and 10 mm or less. Also, the ratio of L12 / L1 is preferably 0.4 or more and 0.8 or less, and the ratio of H12 / H1 is preferably 0.25 or more and 0.75 or less. 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 conductive plate 100 has a relatively thick second thickness near the connection point of the antenna wire 83 welded at the second point P2, thereby enhancing the reinforcing effect near the connection point of the antenna wire 83.

[0069] Because the L12 / L1 ratio is 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. Also, because the H12 / H1 ratio is within the above range, the conductive plate 100 near the conductive adhesive layer 11 that electrically connects the conductive plate 100 and the antenna wire 83 becomes a relatively thin flat section 111, 121. Since the flat sections 111, 121 deform flexibly in response to bending stress of the card, stress is distributed near the conductive adhesive layer 11, reducing the risk of localized material failure or peeling of the conductive adhesive layer 11. This improves the electrical connection reliability between the conductive plate 100 and the antenna connection terminals 73a, 73b.

[0070] Incidentally, as shown in Figure 1(b), the first plate 110 and the second plate 120 have, in plan view, a region that overlaps with the first recess 91, that is, a region exposed from the card base 2, and a region located outside the first recess 91 and embedded inside the card base 2. The former region is the flat portion 111, 121, and the latter region is the displaced portion 112, 122.

[0071] As shown in Figure 1(b), in the plan view, the straight 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 straight lines m1 and m2, respectively. In this case, the first plate 110 has a flat portion 111 in the area on the +X-direction side of straight line m1 that is exposed from the card base 2 in the first recess 91, and a displacement portion 112 in the area on the -X-direction side of straight line m1 that is covered by the card base 2. Similarly, the second plate 120 has a flat portion 121 in the area on the -X-direction side of straight line m2 that is exposed from the card base 2 in the first recess 91, and a displacement portion 122 in the area on the +X-direction side of straight line m2 that is covered by the card base 2.

[0072] 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 portion covered by the card base 2. The width including the portion covered by the card base 2 is L1 as described above, and the width of the first plate 110 exposed from the card base 2 along the X-axis direction is L11.

[0073] 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 within the area of ​​the flat portion 111 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.

[0074] 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 of the card base 2 facing the opening side of the recess 9.

[0075] Furthermore, since the displacement portions 112 and 122, which are part of the first plate 110 and the second plate 120, are covered by the card base 2, 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.

[0076] The first plate 110 and the second plate 120 can be made of metals such as aluminum, stainless steel, or copper, or alloys of multiple such metals. Alternatively, non-metallic conductive materials such as graphite may be used.

[0077] 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.

[0078] (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.

[0079] 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.

[0080] 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.

[0081] This results in the formation of a substrate 72 in which a portion of copper foil with a predetermined pattern remains 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.

[0082] 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.

[0083] It should be noted that the above explanation uses the example of the external connection terminals 71 of the IC module 70 being composed of eight terminals C1 to C8, but the layout of the external connection terminals 71 of the IC module 70 in this disclosure is not limited to such eight terminals, and it goes without saying that it may also be a six-terminal layout without terminals C4 and C8.

[0084] 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.

[0085] 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.

[0086] 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 ACF, etc., without using wires.

[0087] 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 surfaces 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. The location of the conductive plate 100 that is electrically connected to the antenna connection terminals 73a and 73b via the conductive adhesive layer 11 is the first point P1 in the aforementioned flat portions 111 and 121.

[0088] 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.

[0089] 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.

[0090] 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.

[0091] 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.

[0092] 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.

[0093] 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.

[0094] (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.

[0095] 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.

[0096] 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.

[0097] 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.

[0098] 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.

[0099] 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.

[0100] 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.

[0101] Here, the conductive adhesive layer 11 is positioned between the flat portion 111 of the first plate 110, which is 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. Thermal pressure is applied to the substrate 72 from the +Z direction to the -Z direction so that the conductive adhesive layer 11 is compressed from both sides.

[0102] 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.

[0103] 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.

[0104] 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.

[0105] (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).

[0106] First, typically as shown in Figure 3(a), the first plate 110 and the second plate 120, which are conductive plates 100, are bonded to one side of the antenna holding layer 4. More precisely, the first plate preparation 110a and the second plate preparation 120a, which are conductive plate preparations 100a before they become the completed conductive plates 100, the first plate 110 and the second plate 120, are bonded to the antenna holding layer 4. The first plate preparation 110a and the second plate preparation 120a are cut during the process of machining the recess 9 of the card base 2, becoming the final first plate 110 and second plate 120, which have flat parts 111 and 121 and displacement parts 112 and 122.

[0107] However, for the sake of clarity, in this disclosure, conductive plate preparation 100a, first plate preparation 110a, and second plate preparation 120a may be referred to as conductive plate 100, first plate 110, and second plate 120, respectively. One side of the antenna holding layer 4 is the side that faces the antenna holding layer 5 when laminated. Both the first plate preparation 110a and the second plate preparation 120a are made of conductive plates of uniform thickness.

[0108] Next, as shown in Figure 3(b), a coated conductor covered with an insulating material is used as the antenna wire 83, and this is embedded in the forming surface of the antenna holding layer 4 on which the conductive plate preparation 100a is formed, using a winding machine. That is, the winding machine embeds the antenna wire 83 in the antenna holding layer 4, starting from either the first plate preparation 110a or the second plate preparation 120a and ending at the other. 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 preparation 110a and the second plate preparation 120a. The parts of the first plate preparation 110a and the second plate preparation 120a where the ends of the antenna wire 83 are welded become the parts that will become the displacement parts 112 and 122 in the subsequent cutting process of the recess 9.

[0109] Typically, while applying a predetermined 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 preparation 100a 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.

[0110] Next, as shown in Figure 3(c), the antenna retaining layer 5 facing the antenna sheet 12 is prepared. In Figure 3(c), holes 51 are pre-formed in the antenna retaining layer 5 to absorb the protruding portions of the first plate preparation 110a and the second plate preparation 120a from one side of the antenna retaining layer 4, but this step is not essential. Alternatively, recesses may be formed instead of holes.

[0111] 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 a hole 51, it is placed on top of the antenna retaining layer 5 in a position where the hole 51 fits with the protruding portions of the first plate preparation 110a and the second plate preparation 120a. 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 preparation 110a, the second plate preparation 120a, 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 preparation 100a and the antenna wire 83, may be referred to as the second base material.

[0112] 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.

[0113] 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.

[0114] 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.

[0115] As shown in Figure 2(b), the recess 9 consists 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.

[0116] Typically, the machining sequence for the recess 9 involves first cutting the entire surface of the recess 9 to form 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-stage recess 9. At this point, in conjunction with the machining of the recess 9, the first plate preparation 110a is appropriately cut to form a first plate 110 with the desired flat portion 111 and displacement portion 112. Similarly, in conjunction with the machining of the recess 9, the second plate preparation 120a is appropriately cut to form a second plate 120 with the desired flat portion 121 and displacement portion 122.

[0117] 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 (+Z direction side), and the end opposite to the upper end is defined as the lower end (-Z direction side). 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, and 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. Then, in the recess formation process, the conductive plate preparation 100a is machined so that the position of the upper end corresponding to the second point P2 is displaced upward from the position of the upper end corresponding to the first point P1, with the side surface 91b of the recess 9 (first recess 91) as the boundary. The position of the upper end corresponding to the second point P2 is the position where a straight line parallel to the Z axis passing through the second point P2 intersects the upper end.

[0118] As a result, as shown in Figure 2(b), a thin flat portion 111 is formed by cutting the area of ​​the first plate preparation 110a (not shown) that overlaps with the first recess 91 in a cross-sectional view in the XZ plane. In addition, the area that was not cut, with the side surface 91b of the first recess 91 as the boundary, remains as a thick displacement portion 112. As a result, the first plate 110 is formed as a combination of the cut flat portion 111 and the uncut displacement portion 112. This is also true for the second plate 120, which is formed by cutting the second plate preparation 120a and combining the cut flat portion 121 and the uncut displacement portion 122. Consequently, the surfaces of the first plate 110 and the second plate 120 are exposed on the bottom surface 91a of the first recess 91 of the card base 2.

[0119] 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.

[0120] 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.

[0121] 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.

[0122] (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. More precisely, the conductive plates 100 at this stage are conductive plate preparations 100a. Subsequently, while welding the multiple conductive plates 100 and applying heat and pressure, the antenna wire 83 is embedded in the first substrate, and an antenna 80 is formed on one side of the first substrate, with both ends of the antenna wire 83 electrically connected to the multiple conductive plates 100. This is called the antenna formation process.

[0123] 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.

[0124] Meanwhile, an IC module 70 is prepared, comprising a substrate 72, an IC chip 74a, a plurality of antenna connection terminals 73a, 73b, and an external connection terminal 71. The antenna connection terminals 73a, 73b are electrically connected to the IC chip 74a. The external connection terminal 71 is also electrically connected to the IC chip 74a and is exposed on the side of the card base 2 where the recess 9 is formed. This is referred to as the IC module preparation process. 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.

[0125] 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.

[0126] 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 upper end of the conductive plate 100 corresponding to the second point P2 is displaced upward from the position of the upper end corresponding to the first point P1, with the side surface 91b of the recess 9 as the boundary.

[0127] The fact that IC card 1 has the above-described configuration is a feature obtained as a result of undergoing the manufacturing process of IC card 1 as described above. Therefore, a conductive plate 100 with such a configuration can be obtained by first embedding a metal plate of uniform thickness as a conductive plate preparation 100a in a predetermined position on the card base 2. Subsequently, in the process of forming the recess 9 in the card base 2, the conductive plate preparation 100a is cut in accordance with the cutting process of the recess 9 so that it has the flat portions 111, 121 and displacement portions 112, 122 described above, thereby obtaining the desired conductive plate 100. As a result of going through this manufacturing process, the conductive plate 100 can have the flat portions 111, 121 and displacement portions 112, 122 arranged with the side surface 91b of the recess 9 as the boundary.

[0128] Therefore, according to this disclosure, a relatively thick metal plate can be used to form the conductive plate 100, making it relatively easy to obtain materials and suppressing the risk of deformation of the conductive plate due to punching or other processes. Furthermore, since the conductive plate 100 having the desired flat portion and displacement portion can be cut in conjunction with the cutting of the recess 9, a conductive plate 100 with a thin flat portion can be processed without increasing the number of steps. As a result, stress distribution can be achieved by allowing a part of the conductive plate 100 to follow bending stress such as bending of the card, and in particular, material breakage and peeling of the conductive adhesive layer can be suppressed. Thus, 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 the IC module and the antenna. [Explanation of Symbols]

[0129] 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 91b Side 92 Second recess 93 Outer circumference 93a, 93b sides 100 conductive plates 100a Conductive plate preparation 110 Plate 1 110a First plate preparation 111, 121 flat area 112, 122 Displacement section 120 Second Plate 120a Second plate preparation

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 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 upper end of the conductive plate corresponding to the second point is displaced upward from the position of the upper end corresponding to the first point, with the side surface of the recess as the boundary.

2. The dual interface IC card according to claim 1, wherein the position of the lower end corresponding to the second point and the position of the lower end corresponding to the first point are aligned along the long side direction in the conductive plate.

3. The plurality of conductive plates are composed of a first plate and a second plate, The dual interface IC card according to claim 1, 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.

4. 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, The card base comprises a recess forming step, in which a recess for embedding an IC module is formed on the surface of the card base, 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 conductive plate is cut in the recess formation step such that the position of the upper end corresponding to the second point is displaced upward from the position of the upper end corresponding to the first point, with the side surface of the recess as the boundary.

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