IC card and method for manufacturing the same

Abstract

This invention provides a dual-interface IC card in which the IC module can be properly embedded in the recess of the card base, thereby improving the reliability of the electrical connection between the IC module and the antenna. [Solution] The IC card 1 comprises a card base 2 with a recess 9, an IC module 70, and an antenna 80. The IC module 70 comprises a substrate 72, an IC chip body 74, an antenna connection terminal 73a, and an external connection terminal 71. The antenna 80 comprises an antenna wire 83 and a conductive plate. Multiple antenna connection terminals 73a and multiple conductive plates are electrically connected so that the IC chip body 74 and the antenna 80 constitute a contactless communication circuit. In cross-sectional view, the conductive plate comprises a flat portion 111 along the short side direction, and inclined portions 112 extending from one or both ends of the flat portion 111 and inclined toward the interior of the card base 2 from the bottom surface of the recess 9 relative to the flat portion 111.

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 perform input / output of electrical signals through external connection terminals on the card surface and non - contact IC cards that perform input / output of electrical signals by electromagnetic induction or the like through an antenna have been 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, dual - interface IC cards can be used as contact IC cards effective in suppressing external leakage of input / output data during financial settlement, and can be used as highly convenient non - contact IC cards for data exchange in a proximity state when entering or leaving a room or for ticket gates at stations. Therefore, the dual - interface IC cards are also becoming more popular in the market.

[0003] By the way, the manufacturing of a dual - interface IC card is carried out as follows. First, as described in Patent Document 1, a card base material including one or more core sheets is formed, and an embedding planned area for embedding an IC module is cut from the surface of the card base material. Then, the IC module is embedded in the embedding planned area. Here, a conductor is arranged on one of the one or more core sheets, and the conductor forms a winding antenna portion for providing a non - contact communication function and a contact terminal portion that is electrically in contact with the terminals of the IC module, and the contact terminal portion is, for example, arranged 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 dual-interface IC card characterized by using an inlay that includes a coil-shaped antenna made of a covered wire provided inside the inlay, and an antenna-side connection portion made of conductive plates connected to both ends of the antenna.

[0006] Now, let me explain the problems that arise when using a rectangular plate-shaped antenna-side connection part like the one in Patent Document 2. Figure 3 is an enlarged view of the area around the recess 9 for embedding the IC module in a card base 2p of a dual-interface IC card equipped with a substantially rectangular conductive plate 100p similar to that in Patent Document 2. The conductive plate 100p is composed of a first plate 110p on the left and a second plate 120p on the right. First, let's assume that the conductive plate 100p is positioned approximately in the center of the ring-shaped portion of the shallowly cut first recess 91 within the recess 9, in the left and right vertical directions (along the Y-axis direction).

[0007] Here, Figure 3(a) is an enlarged plan view showing the configuration of the card base 2p with the IC module removed. The area indicated by the dashed-dotted rectangle is the planned location for the antenna connection terminals 73a and 73b of the IC module. In plan view, the antenna connection terminals 73a and 73b and the conductive plate 100p are in a superimposed positional relationship, which allows the IC chip embedded in the IC module and the antenna wire 83 connected to the conductive plate 100p to be electrically connected via the conductive adhesive layer.

[0008] Figure 3(b) is a cross-sectional view of the card base 2p of Figure 3(a), taken from the -X direction, of a plane along the DD line parallel to the Y axis at the left side of the ring-shaped portion of the first recess 91. When viewed in this cross-section, the shape of the first plate 110p, which is the conductive plate 100p, is a flat plate along the Y axis, and its left and right ends are approximately perpendicular to the flat plate shape. In other words, the cross-sectional shape of the first plate 110p is a horizontally elongated, approximately rectangular shape. Such a card base 2p is manufactured as follows. First, the conductive plate 100p is bonded to the upper surface of the antenna holding layer 6, and after arranging the predetermined antenna wire, the antenna holding layer 5 is placed on top of the antenna holding layer 6. Then, the oversheet layer 8, core layer 7, antenna holding layers 6 and 5, core layer 4, and oversheet layer 3 are stacked in this order and pressed with heat and pressure to obtain a laminate in which each layer is integrated.

[0009] As shown in Figure 4(a), a relatively shallow first recess 91 is first formed by cutting the above laminate by changing the position of the XYZ coordinates while rotating the milling tool 300 at high speed, creating a predetermined recess 9. This is because if the first plate 110p, which is the conductive plate 100p, is not exposed in the first recess 91, an electrical connection between the antenna wire connected to the conductive plate 100p and the IC module cannot be made. Here, the state of the milling tool 300 and the first plate 110p is shown by a dashed line at the point where the milling tool 300 begins to overlap with the first plate 110p in a plan view from above.

[0010] As shown in Figure 4(a), assume that the milling tool 300 contacts the end face of the first plate 110p. At this time, the cutting resistance load of the milling tool 300 acts in a direction that lifts the first plate 110p upward, and depending on the thickness and rigidity of the first plate 110p, there is a possibility that the first plate 110p may curl up upward. This situation is shown by the dashed line portion of the first plate 110p. If the conductive plate 100p deforms upward in this way, the IC module will not be able to be fixed to the appropriate depth in the recess 9 of the card base. As a result, the IC module may pop out from the surface of the card base, or the adhesive strength between the IC module and the card base may decrease. In addition, there is a concern that the heat and pressure when embedding the IC module will concentrate on the deformed portion of the conductive plate 100p, damaging or deforming the IC module. [Prior art documents] [Patent Documents]

[0011] [Patent Document 1] Japanese Patent Publication No. 2019-219732 [Patent Document 2] Japanese Patent Publication No. 2020-91637 [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 allows the IC module to be well embedded in the recess of the card base and improves the reliability of the electrical connection between the IC module and the antenna. [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, wherein 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 constituting a contactless communication circuit, wherein in a cross-sectional view including the thickness direction and the short-side direction of the card base, the conductive plate comprises a flat portion along the short-side direction of the card base and an inclined portion extending from one or both ends of the flat portion and inclined relative to the flat portion from the bottom surface of the recess toward the interior of the card base.

[0014] Furthermore, in the IC card relating to the second configuration according to another form of this implementation, in the first configuration, the inclined portion may extend so as to be inclined at a certain angle with respect to the flat portion in a cross-sectional view including the thickness direction and the short side direction of the card base.

[0015] Furthermore, in the third configuration of an IC card according to another form of this implementation, in the first configuration, the inclined portion may extend in a substantially arc shape relative to the flat portion in a cross-sectional view including the thickness direction and the short side direction of the card base.

[0016] Furthermore, in the fourth configuration of an alternative form of this embodiment, the IC card in the first configuration may have a trapezoidal shape in a cross-sectional view including the thickness direction and the short side direction of the card base, with the contour line on the side closer to the recess as the upper base and the contour line opposite to the contour line on the side closer to the recess as the lower base.

[0017] Furthermore, in the IC card relating to the fifth configuration according to another form of this implementation, in the second configuration, when the inclination angle of the inclined portion with respect to the flat portion is θ in a cross-sectional view including the thickness direction and the short side direction of the card base, and the distance from the straight line passing through the side of the flat portion closest to the recess to the end of the side of the inclined portion closest to the recess is d, then θ may be 5° or more and 45° or less, and d may be 0.03 mm or more and 0.10 mm or less.

[0018] Furthermore, in an IC card relating to a sixth configuration according to another form of this embodiment, in any of the first to fifth configurations, the inclined portion may extend to both ends of the flat portion in a cross-sectional view including the thickness direction and the short side direction of the card base, and the shape of the conductive plate may be symmetrical with respect to the thickness direction.

[0019] Furthermore, in an IC card relating to the seventh configuration according to another form of this embodiment, in any of the first to sixth configurations, a through hole may be formed in the inclined portion in a cross-sectional view including the thickness direction and the short side direction of the card base.

[0020] A method for manufacturing a dual-interface IC card capable of contact and contactless communication with external devices, according to the eighth configuration of this embodiment, includes: an antenna forming step of bonding a plurality of conductive plates to a first substrate, then embedding antenna wires into the first substrate while welding them to the plurality of conductive plates and applying heat and pressure, thereby forming an antenna on one side of the first substrate where both ends of the antenna wires are electrically connected to the plurality of conductive plates; a lamination step of laminating a second substrate on the first substrate with the antenna formed thereon, sandwiching the antenna; a punching step of punching out the laminate formed by the first substrate and the second substrate into a card-sized card base; a recess forming step of forming a recess in the card base for embedding an IC module, with the opening of the recess being on the surface of the card base on the side closer to the first substrate than to the second substrate; and a substrate and an IC chip arranged on one side of the substrate. The present invention provides an IC module, comprising: an IC module preparation step of preparing an IC module comprising: a plurality of antenna connection terminals electrically connected to the IC chip; 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 of electrically connecting a plurality of the antenna connection terminals and a plurality of the 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 short side direction of the card base, the conductive plate comprises a flat portion along the short side direction of the card base and an inclined portion extending from one or both ends of the flat portion and inclined toward the interior of the card base from the bottom surface of the recess relative to the flat portion. [Effects of the Invention]

[0021] According to this embodiment, it is possible to provide a dual-interface IC card and a method for manufacturing the same, in which the IC module can be well embedded in the recess of the card base and the reliability of the electrical connection between the IC module and the antenna can be improved. [Brief explanation of the drawing]

[0022] [Figure 1] A plan view for explaining the structure of a dual-interface IC card according to the first embodiment of the present disclosure and an enlarged plan view of the vicinity of a recess of a card substrate with the IC module removed. [Figure 2] A cross-sectional view of lines A-A and B1-B1 including the IC module in FIG. 1(b). [Figure 3] An enlarged plan view of the vicinity of a recess of a card substrate when the IC module is removed and a cross-sectional view of line D-D for explaining a conductive plate according to the prior art. [Figure 4] A cross-sectional view for explaining the formation of the recess. [Figure 5] An enlarged view of the conductive plate in cross-section. [Figure 6] Views of the IC module from the front and back respectively and an enlarged view of part C in FIG. 2(a). [Figure 7] An enlarged plan view of the vicinity of a recess of a card substrate with the IC module removed and a cross-sectional view of line B2-B2 including the IC module for a dual-interface IC card according to the second embodiment of the present disclosure. [Figure 8] A cross-sectional view for explaining the structure of a dual-interface IC card according to the third embodiment of the present disclosure and an enlarged view of the conductive plate in cross-section. [Figure 9] A cross-sectional view for explaining the structure of a dual-interface IC card according to the fourth embodiment of the present disclosure and an enlarged view of the conductive plate in cross-section.

Embodiments for Carrying out the Invention

[0023] 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.

[0024] The following figures are schematic representations. Therefore, the size and shape of each part have been exaggerated as appropriate for ease of understanding. Furthermore, hatching indicating cross-sections of members has been omitted in each figure as appropriate. The dimensions and other numerical values ​​and material names of each member described herein are examples of embodiments and are not limiting; they can be selected and used as appropriate. In this specification, terms specifying shape and geometric conditions, such as parallel, orthogonal, and perpendicular, are used not only in their strict sense but also to include substantially equivalent states.

[0025] 1. First Embodiment of the Disclosure An example of an embodiment of the IC card of this disclosure will be described. The IC card 1 of the first embodiment is a dual-interface IC card. Here, for the sake of explanation, an XYZ coordinate system is set for the IC card 1. First, as shown in Figures 1(a), 2(a), and 2(b), the Z axis is taken in the direction of the normal to the main surface of the IC card 1. Then, the direction from the main surface on which the external connection terminals 71 of the IC module 70 are not located toward the main surface on which the external connection terminals 71 are located is defined as the +Z direction or upward in the thickness direction, and the opposite direction is defined as the -Z direction or downward in the thickness direction.

[0026] Furthermore, when viewing IC card 1 from the +Z direction, the line perpendicular to both short sides of IC card 1 and the Z axis is defined as the X axis. Also, the direction from one short side closer to the external connection terminal 71 to the other short side is defined as the +X direction or right direction, and the opposite direction is defined as the -X direction or left direction. In addition, the axis perpendicular to the X and Z axes is defined as the Y axis, and the direction from one long side farther from the external connection terminal 71 to the other long side is defined as the +Y direction or upward, and the opposite direction is defined as the -Y direction or downward.

[0027] 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 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 a cross-sectional view of IC card 1 from Figure 1(a) as seen from the -X direction, cut along line B1-B1 parallel to the Y axis. Figures 2(a) and 2(b) are cross-sectional views with IC module 70 mounted to show the relationship with IC module 70.

[0028] On the other hand, Figure 3(a), like Figure 1(b), is an enlarged plan view showing the configuration of the card base 2p with the IC module 70 removed from Figure 1(a), but it shows the case where the conductive plate is the conventional conductive plate 100p. Figure 3(b) is a cross-sectional view of the card base 2p of Figure 3(a) as seen from the -X direction, cut along a plane parallel to the Y axis and the DD line. Unlike Figure 2(b), the IC module 70 is not shown.

[0029] Figure 4(a) is a diagram illustrating the process of forming a recess 9 in the card base 2p with a milling tool 300. Figure 4(b) is a diagram illustrating the process of forming a recess 9 in the card base 2 of this disclosure with a milling tool 300, in comparison with Figure 4(a). Figure 5 is an enlarged view illustrating the details of the configuration of the first plate 110 in Figure 2(b).

[0030] Figure 6(a) is a view of the IC module 70 from the +Z direction, looking towards the external connection terminal 71, similar to Figure 1(a). Figure 6(b) is a view of the IC module 70 from the -Z direction, opposite to that of Figure 6(a). Here, most of the molded portion 74b of the IC chip body 74 is omitted in order to allow a view of the interior. Figure 6(c) is an enlarged cross-sectional view of section C near the antenna connection terminal 73a in Figure 2(a).

[0031] 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.

[0032] 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.

[0033] The detailed configuration will be described later, but as shown in Figure 6(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.

[0034] As shown in Figures 1(a) and 2(a), 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(a), 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, respectively.

[0035] 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.

[0036] 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.

[0037] In the cross-sectional view of Figure 2(b), the first plate 110, which is the conductive plate 100, has a flat portion 111 along the short side direction of the card base 2, in a cross-sectional view including the thickness direction (Z-axis direction) and the short side direction (Y-axis direction) of the card base 2. Furthermore, the first plate 110 has inclined portions 112 that extend from both ends of the flat portion 111 and inclined toward the interior of the card base 2 from the bottom surface 91a of the first recess 91, which is a relatively shallow recess among the recesses 9 of the flat portion 111. Note that the inclined portions 112 may extend from only one end of the flat portion 111.

[0038] As shown in Figure 4(b), the milling tool 300 is rotated at high speed, and its position in the XYZ coordinate system is changed to first form a relatively shallow first recess 91 as a predetermined recess 9 by cutting. In this process, it is necessary to expose the first plate 110, which is the conductive plate 100, in the first recess 91 so that an electrical connection with the IC module 70 can be made. Here, the state of the milling tool 300 at the point where it begins to overlap with the first plate 110 in a plan view from above is shown by a dashed line.

[0039] As shown in Figure 4(b), even if the milling tool 300 moves parallel to the -Y direction, the possibility of it directly contacting the end face of the first plate 110 is low. The reason for this is as follows. Unlike the case of the first plate 110p according to the prior art shown in Figure 4(a) above, an inclined portion 112 is arranged at one end of the flat portion 111 of the first plate 110 on the +Y direction side, inclined so as to move away from the bottom surface 91a of the first recess 91 toward the -Z direction inside the card base 2 relative to the flat portion 111. One end of the inclined portion 112 is embedded toward a deeper position in the card base 2 relative to the flat portion 111, resulting in a positional relationship that makes it difficult for the tip of the milling tool 300 to make contact.

[0040] Therefore, the tip of the milling tool 300 makes contact with the first plate 110 at a point closer to the flat portion 111, rather than at one end of the inclined portion 112, thereby minimizing the upward curling of the first plate 110 as described in Figure 4(a). As a result, the IC card 1 allows the IC module 70 to be properly embedded in the recess 9 of the card base 2, providing a dual-interface IC card and a manufacturing method thereof that improves the reliability of the electrical connection between the IC module 70 and the antenna 80.

[0041] The configuration of the IC card 1 of this embodiment and the details of its manufacturing method are described below.

[0042] (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, a core layer 7, antenna holding layers 6 and 5, a core layer 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 6 and 5.

[0043] The card base 2 may refer to both the form before the recess 9 is formed and the form after the recess 9 is formed, and may refer to both the form without the antenna 80 and the form with the antenna 80. In addition, both ends of the antenna wire 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 toward each other along the X axis. The first plate 110 and the second plate 120 are elements of the conductive plate 100.

[0044] 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.

[0045] 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 core layer 4 or 7, and printing may be applied to the surface of the core layer 4 or 7 adjacent to the oversheet layer 3 or 8.

[0046] 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.

[0047] (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 4 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 4 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.

[0048] (ii) Antenna holding layer The antenna retaining layer is also called the inner layer, similar to the core layer. The antenna retaining layers 5 and 6 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 4 and 7 can be used. The antenna retaining layers 5 and 6 may be made of the same material as the core layers 4 and 7, or they may be made of different materials. The thickness of the antenna retaining layers 5 and 6 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.

[0049] (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 4 and 7 and the antenna holding layers 5 and 6 mentioned above.

[0050] 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 core layers 4 and 7 by thermal transfer or the like.

[0051] (iv) Antenna sheet In this embodiment, as will be described later, an antenna 80 is formed on one surface of the antenna holding layer 5 or 6, and both ends of the antenna wires 83 constituting the antenna 80 are electrically connected to the first plate 110 and the second plate 120. The formation of the antenna 80 on the antenna holding layer 5 or 6 is carried out, for example, as follows. First, the first plate 110 and the second plate 120 are bonded and fixed to the surface of the antenna holding layer 5 facing the antenna holding layer 6 before lamination by applying heat and pressure or the like. At this time, adhesive may be applied to the surface of the antenna holding layer 5 before placing the first plate 110 and the second plate 120. The first plate 110 and the second plate 120 are arranged side by side in the left-right direction at the planned mounting position of the IC module 70, and a portion of them is positioned to overlap with the antenna connection terminals 73a and 73b of the IC module 70 when mounted.

[0052] Here, when bonding and fixing the first plate 110 and the second plate 120 to the surface of the antenna holding layer 5 facing the antenna holding layer 6, it is preferable to arrange the first plate 110 and the second plate 120 as follows. That is, the first plate 110 and the second plate 120 are arranged such that the inclined portions 112 at both ends of the first plate 110 and the second plate 120 are inclined in the direction from the antenna holding layer 5 toward the antenna holding layer 6. By doing so, bonding and fixing the first plate 110 and the second plate 120 to the antenna holding layer 5 becomes easier compared to the case where the inclined portions 112 at both ends of the first plate 110 and the second plate 120 are inclined in the direction from the antenna holding layer 6 toward the antenna holding layer 5.

[0053] Assume that the first plate 110, etc., is placed on the antenna retaining layer 5 such that the inclined portions 112 at both ends of the first plate 110, etc., are inclined in the direction from the antenna retaining layer 5 to the antenna retaining layer 6. In this case, when forming the recess 9 for embedding the IC module 70 in the card base 2, the opening of the recess 9 will be formed on the surface closer to the antenna retaining layer 5 than to the antenna retaining layer 6.

[0054] Conversely, when bonding and fixing the first plate 110 and the second plate 120 (hereinafter also referred to as the first plate, etc.) to the surface of the antenna holding layer 6 facing the antenna holding layer 5, assume that the inclined portions 112 at both ends of the first plate 110, etc. are oriented in a direction toward the antenna holding layer 6 from the antenna holding layer 5. In this case, the flat portion 111 of the first plate 110, etc. may lift up from the antenna holding layer 5, making it difficult to bond and fix the first plate 110, etc. to the antenna holding layer 6. However, if the inclined portions 112 of the first plate 110, etc. are pressed firmly into the antenna holding layer 6 while applying heat and pressure, it is possible to bond and fix the first plate 110, etc. to the antenna holding layer 6.

[0055] Subsequently, the tip of the antenna wire 83 is welded to either the first plate 110 or the second plate 120. Then, starting from this point, a predetermined heat pressure is applied to the antenna wire 83, and the insulated conductor, the antenna wire 83, which is covered with an insulating material, is embedded into the surface of the antenna holding layer 5 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 5. The embedded antenna wire 83 is cut, and the tip of the cut antenna wire 83 is welded to the other of the first plate 110 or the second plate 120, using the cut tip as the endpoint.

[0056] The starting and ending ends of the antenna wire 83 are electrically connected to either the first plate 110 or the second plate 120 by welding. In this way, an antenna holding layer 5 (antenna sheet 12) with the antenna 80 formed is obtained. The intermediate product in which the antenna 80 is embedded in the antenna holding layer 5 or 6 is sometimes referred to as the antenna sheet 12. The antenna sheet 12 can be distributed to the market as a component for manufacturing the IC card 1 on its own. Alternatively, a business model may exist in which sheet material such as the antenna holding layer is supplied to a processing company, which processes it into an antenna sheet 12 and delivers it to the supplier.

[0057] (v) antenna In the antenna 80 formed on the antenna holding layer 5 (or antenna holding layer 6), the antenna connection terminals 73a and 73b of the IC module 70 are electrically connected to a pair of first plates 110 and second plates 120 to which multiple ends of the antenna wire 83 are electrically connected. As a result, the IC chip 74a and antenna 80 of the IC module 70 constitute a contactless communication circuit. This communication circuit may, for example, perform proximity communication using the 13.56 MHz HF frequency band specified in ISO / IEC 18092 or ISO / IEC 144443. Alternatively, it may perform communication using other frequencies, such as the 920 MHz UHF frequency band, the 125 kHz LF frequency band, or the 2.45 GHz microwave frequency band.

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

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

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

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

[0062] On the other hand, as shown in Figure 2(b), the first plate 110 and the second plate 120 have the following shapes when viewed in cross-section along a plane that includes the Z-axis direction, which is the normal direction to the main surface of the IC card 1, and the short-side direction (Y-axis direction) of the card base 2. Specifically, the first plate 110 includes a flat portion 111 along the short-side direction (Y-axis direction) of the card base 2, and inclined portions 112 that extend from both ends of the flat portion 111 and inclined relative to the flat portion 111 so as to move away from the bottom surface 91a of the first recess 91, which is a recess 9, toward the interior of the card base 2. Similarly, the second plate 120 includes a flat portion 121 along the short-side direction of the card base 2, and inclined portions 122 that extend from both ends of the flat portion 121 and inclined relative to the flat portion 121 so as to move away from the bottom surface 91a of the first recess 91 toward the interior of the card base 2.

[0063] In other words, the first plate 110 comprises a flat portion 111 along the short side direction of the card base 2, and inclined portions 112 bent in the -Z direction from both ends so as to sink towards the card base 2. The second plate 120 comprises a flat portion 121 along the short side direction of the card base 2, and inclined portions 122 bent in the -Z direction from both ends so as to sink towards the card base 2.

[0064] 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 5, the area near the center of the first plate 110 is a flat portion 111 along the Y-axis direction. The surface of the flat portion 111 on the +Z side is substantially flush with the bottom surface 91a of the first recess 91 of the card base 2. However, the front and back surfaces of the flat portion 111 do not need to be perfectly flat; it is sufficient if they are substantially approximate to be flat. Also, the flat portion 111 does not need to be perfectly parallel to the Y-axis, which is the short side direction; it may have an inclination of about 5° or less with respect to the Y-axis. In cross-section, the axis of the inclined portion 112 intersects the axis of the flat portion 111, and the angle of intersection between them is θ11. The inclined portion 112 extends from the flat portion 111 such that its axis follows a straight line that is inclined in the -Z direction by an inclination angle θ11 with respect to the axis of the flat portion 111.

[0065] Similarly, the axis of the inclined portion 122 intersects the axis of the flat portion 121 in a cross-sectional view, and the angle of intersection between them is θ21. The inclined portion 122 extends from the flat portion 121 such that its axis follows a straight line that is inclined by an angle θ21 in the -Z direction relative to the axis of the flat portion 121. The inclination angle θ11 is referred to as the inclination angle of the inclined portion 112 with respect to the flat portion 111, and the angle θ21 is referred to as the inclination angle of the inclined portion 122 with respect to the flat portion 121. In a cross-sectional view including the thickness direction and the short side direction of the card base 2, the inclined portions 112 and 122 extend from the flat portions 111 and 121, respectively, at a constant angle.

[0066] Also, in the same cross-sectional view, d11 is defined as the distance from the line passing through the edge of the flat portion 111 closest to the first recess 91 (recess 9) to the end of the edge of the inclined portion 112 on the +Y direction side closest to the first recess 91. Furthermore, d21 is defined as the distance from the line passing through the edge of the flat portion 111 closest to the first recess 91 (recess 9) to the end of the edge of the inclined portion 112 on the -Y direction side closest to the first recess 91. This distance may be referred to as the predetermined distance. In this case, it is preferable that θ11 is 5° or more and 45° or less, and d11 is 0.03 mm or more and 0.10 mm or less, and it is even more preferable that θ11 is 10° or more and 30° or less, and d11 is 0.05 mm or more and 0.07 mm or less.

[0067] The former allows the first plate 110 to adhere well to the antenna holding layers 5 and 6, suppressing the peeling of the flat portion 111 or inclined portion 112 from either substrate. In addition to the above, since the inclined portion 112 is reliably separated by a predetermined distance from the bottom surface 91a of the recess 9, shape defects of the first plate 110 during machining of the recess 9 can be suppressed. On the other hand, the latter further enhances the above effect, and since the uneven shape of the first plate 110 in the thickness direction of the card base 2 falls within a certain range, the surface smoothness of the card base 2 can be further improved. The above also applies when the first plate 110 is replaced with the second plate 120, θ11 is replaced with θ21, and d11 is replaced with d21.

[0068] On the other hand, it is preferable that the inclination angles θ11 and θ21 and the predetermined distances d11 and d21 be the same in at least one of the first plate and the second plate 120. However, the inclination angles being the same includes the difference in angle being 5° or less, and the predetermined distances being the same includes the difference in predetermined distance being 0.01 mm or less. In other words, in a cross-sectional view including the thickness direction and the short side direction of the card base 2, the inclined portions 112 and 122 extend from both ends of the flat portions 111 and 121, respectively, and the shapes of the first plate 110 and the second plate 120 are symmetrical with respect to the thickness direction.

[0069] By doing this, when machining the first recess 91, the conditions for approaching the conductive plate 100 are almost the same whether the milling tool approaches the conductive plate 100 from the +Y direction or from the -Y direction. This increases the degree of freedom of the milling tool's machining program and allows the quality of the conductive plate 100 to be consistently stable regardless of the content of the milling tool's machining program.

[0070] In this embodiment, the conductive plate was described as having a flat portion along the short side direction of the card base and inclined portions extending from both ends of the flat portion, which are inclined relative to the flat portion from the bottom surface of the recess toward the interior of the card base. However, the disclosure is not limited thereto, and the conductive plate may also have a flat portion along the short side direction of the card base and an inclined portion extending only from one end of the flat portion, which is inclined relative to the flat portion from the bottom surface of the recess toward the interior of the card base. In this case, when machining the first recess, if the milling tool's machining program is created and set so that the milling tool approaches the conductive plate from the side with the inclined portion, the quality of the conductive plate can be stabilized.

[0071] Incidentally, as shown in Figure 1(b), the first plate 110 and the second plate 120 have, in a plan view, a region that overlaps with the first recess 91, that is, a region exposed from the card base 2, and a region that is located outside the first recess 91 and embedded inside the card base 2.

[0072] As shown in Figure 1(b), in the plan view, the lines that overlap the -X-direction side 93a and the +X-direction side 93b of the outer circumference 93 of the recess 9 are denoted as lines m1 and m2, respectively. In this case, the region of the first plate 110 on the +X-direction side of line m1 is exposed from the card base 2 in the first recess 91, and the region on the -X-direction side of line m1 is covered by the card base 2. Similarly, the region of the second plate 120 on the -X-direction side of line m2 is exposed from the card base 2 in the first recess 91, and the region on the +X-direction side of line m2 is covered by the card base 2.

[0073] 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. Of the vertical width of the first plate 110 exposed from the card base 2 in the first recess 91 along the Y-axis direction, the vertical width of the flat portion 111 having a surface along the bottom surface 91a of the first recess 91 is W21. In addition, the vertical width of the first plate 110 along the Y-axis direction, including the inclined portions 112 in the +Y and -Y directions, is W22, which is greater than W21.

[0074] 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 exposed on the bottom surface 91a of the first recess 91 of the first plate 110. This is because a stable contact area for electrical connection between the antenna connection terminal 73a and the first plate 110 can be obtained. The same applies to the second plate 120. In this way, the multiple antenna connection terminals 73a and 73b are electrically connected to the conductive plates, the first plate 110 and the second plate 120, on the surfaces of the card base 2 facing the opening side of the recess 9.

[0075] Furthermore, because a portion of the first plate 110 and the second plate 120 are covered by the card base 2 in this manner, the holding effect of the first plate 110 and the second plate 120 against external forces such as the cutting resistance of the end mill blade when forming the recess 9 is enhanced. Therefore, it is possible to suppress the plates from unintentionally peeling off from the card base 2 and shifting their position.

[0076] The first plate 110 and the second plate 120 may have a laminated structure including at least two layers: a first member and a second member laminated on the +Z side of the first member. In this case, it is preferable that the second member is less susceptible to oxidation than the first member. A member that is less susceptible to oxidation can be rephrased as, for example, if both the first and second members are metals, the second member being a metal with a lower ionization tendency than the first member. As an example of such metals, the first member may be aluminum, iron, nickel, or copper, and the second member may be silver, palladium, platinum, or gold.

[0077] Considering the ease of material procurement, cost, processability, and electrical properties, it is preferable to use highly conductive copper as the first component and silver plating as the second component among those listed above. By using copper, which can ensure sufficient conductivity, as the first component, and silver, which is resistant to oxidation and easily exposes the metal interface when cutting the resin layer with an end mill, as the second component, good electrical properties and processability can be obtained while suppressing cost increases.

[0078] On the other hand, the first plate 110 and the second plate 120 may not have the laminated structure of two or three or more layers described above, but may be made of only a single material. In this case, the single material is limited to a conductive material, and for example, the materials described above as the first and second materials, or their alloys, can be used. Preferably, highly conductive materials such as copper, aluminum, or stainless steel can be selected. Using a single material makes material procurement and processing easier and leads to cost reduction.

[0079] 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 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 passing through the center of the recess 9. Furthermore, the inclination angles and predetermined distances of the first plate 110 and the second plate 120 may be different values.

[0080] (b) IC module Next, the main components of the IC module 70 will be described, primarily based on Figures 1(a), 6(a), 6(b), and 6(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 the conductive adhesive layer 11. This allows the IC card 1 to form a contactless communication circuit.

[0081] 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.

[0082] 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.

[0083] 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.

[0084] As shown in Figures 1(a) and 6(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.

[0085] Figure 6(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.

[0086] 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.

[0087] 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 and directly connected without wires.

[0088] On the side of the substrate 72 opposite to the external connection terminal 71, a pair of antenna connection terminals 73a and 73b are arranged on both the left and right sides of the IC chip 74a, forming conductive regions that are roughly T-shaped or H-shaped in plan view. The multiple antenna connection terminals 73a and 73b are electrically connected to the corresponding multiple conductive plates 100 (first plate 110 and second plate 120) on the sides of the conductive plates 100 (first plate 110 and second plate 120) that face the opening side of the recess 9 of the card base 2.

[0089] Taking Figure 6(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.

[0090] 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.

[0091] 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.

[0092] 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.

[0093] 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.

[0094] 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.

[0095] (c) Conductive adhesive layer After forming a recess 9 in the card base 2 for embedding the IC module 70 by cutting with an end mill or the like, the IC module 70 is embedded and fixed in the recess 9, and a conductive adhesive layer 11 for electrical and mechanical connection will be described. As shown in Figure 6(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) and the substrate 72 of the IC module 70 and the antenna connection terminals 73a or 73b (not shown) formed on the substrate 72.

[0096] 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.

[0097] 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.

[0098] 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.

[0099] However, the conductive adhesive layer 11 may be applied and attached to cover only the area of ​​the antenna connection terminals 73a and 73b on the back surface of the substrate 72, while another adhesive that does not have conductivity may be applied and attached to the rest of the back surface of the substrate 72. This is because, since conductivity does not need to be considered for the other adhesive, it is easier to select an adhesive that is advantageous for mechanical connection.

[0100] 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.

[0101] 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 6(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.

[0102] Here, thermal pressure is applied to the substrate 72 from the +Z direction to the -Z direction so that the conductive adhesive layer 11, which is positioned between the first plate 110 electrically connected to the tip of the antenna wire 83, the substrate 72 of the IC module 70, and the antenna connection terminal 73a formed on the substrate 72, is compressed.

[0103] 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 6 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 6, 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.

[0104] On the other hand, between the antenna holding layer 6 and the substrate 72 in the area where the antenna connection terminal 73a is not present, 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 the heat and pressure mechanically connects the antenna holding layer 6 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.

[0105] 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.

[0106] (d) Method of manufacturing an IC card Next, an example of a manufacturing method for an 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.

[0107] First, the conductive plates 100, namely the first plate 110 and the second plate 120, are bonded to the surface of either the antenna holding layer 5 or 6, on the side not adjacent to the core layer 4 or 7. Both plates may be bonded and fixed to the surface of the antenna holding layer 5 or 6 via adhesive. The first plate 110 and the second plate 120 are bent in advance to have predetermined inclination angles exemplified as θ11 and θ21, and predetermined distances exemplified as d11 and d21, as described above.

[0108] Typically, the first plate 110 and the second plate 120 are positioned on the surface of the antenna retaining layer 5 facing the antenna retaining layer 6 such that the inclined portions 112 and 122 at both ends of the first plate 110 and the second plate 120 are inclined in the direction from the antenna retaining layer 5 toward the antenna retaining layer 6. In other words, the first plate 110 and the second plate 120 are positioned on the antenna retaining layer 5 such that the inclined portions 112 and 122 are bent in a direction away from the antenna retaining layer 5, i.e., away from the antenna retaining layer 5. By doing so, the adhesion and fixing of the first plate 110 and the second plate 120 to the antenna retaining layer 5 becomes easier compared to the case where the inclined portions 112 at both ends of the first plate 110 and the second plate 120 are inclined in the direction from the antenna retaining layer 6 toward the antenna retaining layer 5.

[0109] Next, the insulated conductor covered with an insulating material is used as the antenna wire 83 and is embedded by a winding machine into the surface of the antenna holding layer 5 on which the conductive plate 100 is formed, with either the first plate 110 or the second plate 120 as the starting point and the other as the ending point. At the starting and ending points of the antenna wire 83, the winding machine welds the ends of the antenna wire 83 to the first plate 110 and the second plate 120.

[0110] Specifically, for example, while applying a predetermined amount of heat and pressure to the antenna holding layer 5, the 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 holding layer 5. At this time, the antenna holding layer 5 may also be referred to as the first substrate. The conductive plate 100 and the antenna wires 83 are arranged on the back side of the antenna holding layer 5, i.e., on the -Z direction side.

[0111] Next, as shown in Figures 2(a) and 2(b), the oversheet layer 8, core layer 7, antenna holding layers 6 and 5, core layer 4, and oversheet layer 3 are stacked in this order from the bottom in the thickness direction. Then, the laminate of large sheets in which the cards are arranged in multiple directions is sandwiched between stainless steel plates from above and below in the thickness direction, and heat and pressure are applied to the laminate through the stainless steel plates. At this time, the antenna 80 is formed in advance on the back side of, for example, the antenna holding layer 5 so as to be sandwiched between the antenna holding layers 5 and 6. At this time, the antenna holding layer 6, which is positioned opposite the antenna holding layer 5, which is the first base material, and is laminated to the first base material so as to sandwich the antenna 80, may be referred to as the second base material.

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

[0113] The large sheet of card base material obtained as described above, in which cards are arranged in multiple rows vertically and horizontally, is punched out using a die-cutting machine as card base material 2 with a card size conforming to ISO / IEC 7816-1. In addition, a recess 9 for embedding the IC module 70 is formed in the card base material 2 by cutting with an end mill. This results in cut card base material 2. The recess 9 for embedding the IC module 70 in the card base material 2 is 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 base material than to the second base material.

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

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

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

[0117] Subsequently, an IC module 70 with a conductive adhesive layer 11 attached is embedded in the card base 2 where the recess 9 is formed, and a predetermined heat block is pressed against the external connection terminal 71, applying predetermined heat and pressure toward the card base 2 for a predetermined time. By melting the conductive adhesive layer 11 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. At the same time, a mechanical connection is made between the IC module 70 and the card base 2. Although the time and heat and pressure conditions applied vary depending on the type and composition of the ACF, 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.

[0118] 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 5, which is the first substrate. Then, while welding the antenna wire 83 to the multiple conductive plates 100 and applying heat and pressure, an antenna 80 is embedded in the first substrate, with both ends of the antenna wire 83 electrically connected to the multiple conductive plates 100, forming an antenna 80 on one side of the first substrate. This is called the antenna formation process.

[0119] Next, the second substrate 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.

[0120] On the other hand, an IC module 70 is prepared, comprising a substrate 72, an IC chip 74a and a plurality of antenna connection terminals 73a, 73b electrically connected to the IC chip 74a, and an external connection terminal 71 electrically connected to the IC chip 74a and exposed on the side of the card base 2 where the recess 9 is formed. This is referred to as the IC module preparation step. The IC chip 74a and the plurality of antenna connection terminals 73a, 73b are arranged on one side of the substrate 72. The external connection terminal 71 is arranged on the other side of the substrate 72.

[0121] 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.

[0122] Here, in a cross-sectional view including the thickness direction and the short-side direction of the card base 2, the first plate 110, which is the conductive plate 100, comprises a flat portion 111 and an inclined portion 112. The second plate 120, which is also the conductive plate 100, comprises a flat portion 121 and an inclined portion 122. The flat portions 111 and 121 are arranged along the short-side direction of the card base 2. The inclined portions 112 and 122 extend from one or both ends of the flat portions 111 and 121 and are inclined toward the interior of the card base 2 from the bottom surface 91a of the recess 9 with respect to the flat portions 111 and 121, respectively.

[0123] (e) IC card of the first embodiment relating to this disclosure In summary, the IC card 1 of the first embodiment of the present disclosure is a dual-interface IC card capable of contact and contactless communication. The IC card 1 comprises a card base 2 having a recess 9, an IC module 70 embedded in the recess 9, and an antenna 80 disposed inside the card base 2. The IC module 70 comprises a substrate 72, an IC chip 74a and a plurality of antenna connection terminals 73a, 73b, and an external connection terminal 71 electrically connected to the IC chip 74a and exposed on the side of the card base 2 where the recess 9 is formed. The IC chip 74a and the plurality of antenna connection terminals 73a, 73b are located on one side of the substrate 72. The external connection terminal 71 is located on the other side of the substrate 72.

[0124] The antenna 80 comprises an antenna wire 83 and a plurality of conductive plates 100 positioned at the end of the antenna wire 83 and electrically connected to the antenna wire 83. The plurality of conductive plates 100 are, for example, a first plate 110 and a second plate 120. The plurality of antenna connection terminals 73a, 73b and the plurality of conductive plates 100 are electrically connected by a conductive adhesive layer 11, so that the IC chip 74a and the antenna 80 constitute a contactless communication circuit. Here, in a cross-sectional view including the thickness direction and the short side direction of the card base 2, the conductive plate 100 comprises a flat portion along the short side direction of the card base 2 and an inclined portion extending from one or both ends of the flat portion and inclined toward the interior of the card base 2 from the bottom surface 91a of the recess 9 relative to the flat portion. The first plate 110 comprises a flat portion 111 and an inclined portion 112, and the second plate 120 comprises a flat portion 121 and an inclined portion 122.

[0125] The IC card 1 has the above configuration, which reduces the possibility of the milling tool directly contacting the upper or lower end of the conductive plate 100, i.e., the end on the +Y direction or the end on the -Y direction, when moving along the Y-axis direction during machining of the recess 9, particularly the first recess 91. The upper or lower end of the conductive plate 100 is an inclined portion 112 and 122 that extends to the flat portion 111 and 121, respectively. This is because the inclined portions 112 and 122 are bent so that they escape from the bottom surface 91a of the recess 9 into the interior of the card base 2. Therefore, even if the milling tool were to directly contact the conductive plate 100, the contact point could be shifted closer to the center than to the edge of the conductive plate 100. As a result, the load that would cause the edge of the conductive plate 100 to be lifted away from the card base 2 due to the cutting resistance of the milling tool can be effectively suppressed.

[0126] As a result, the IC card 1 allows the IC module 70 to be properly embedded in the recess 9 of the card base 2, and improves the reliability of the electrical connection between the IC module 70 and the antenna 80. This provides a dual-interface IC card and a method for manufacturing the same.

[0127] 2. Second Embodiment of the Present Disclosure Next, as another example of an embodiment of the IC card of this disclosure, an IC card 1a of a second embodiment will be described. This embodiment will be described focusing on the differences from the IC card 1 according to the first embodiment. Figure 7(a) is a diagram corresponding to Figure 1(b) showing the conductive plate 100a positioned approximately in the center of the first recess 91, along the left and right vertical directions of the ring-shaped portion of the first recess 91 of the recess 9, that is, along the Y-axis direction, which is the short side direction of the card base 2. Specifically, the conductive plate 100a consists of a first plate 110a and a second plate 120a. Figure 7(b) is a cross-sectional view taken from the -X direction of the IC card 1a of Figure 7(a) cut along the line B2-B2 parallel to the Y-axis.

[0128] The IC card 1a of the second embodiment differs from the IC card 1 of the first embodiment in that, as shown in Figures 7(a) and 7(b), substantially circular through holes 200 are formed in the inclined portions 112a and 122a on the +Y and -Y directions of the first plate 110a and the second plate 120a, respectively. Conversely, aside from this point, the configuration of IC card 1a is the same as that of IC card 1.

[0129] As shown in Figure 7(a), all through-holes 200 are substantially circular in shape and are formed in four locations on the inclined portion 112a at the upper end (+Y direction end) of the first plate 110a, and also in four locations on the inclined portion 112a at the lower end (-Y direction end). Of the four through-holes 200, three are formed in the region overlapping with the first recess 91, and one is formed in a position that does not overlap with the first recess 91 and is hidden by the card base 2a. The second plate 120a is also configured symmetrically, similar to the first plate 110a. However, the position and number of through-holes 200 in the inclined portions 112a and 122a are not limited to these, and may be in any location and number within the region of the inclined portions 112a and 122a. For example, there may be only one through-hole instead of four, or there may be five or more. Furthermore, the shape of the through-holes 200 may be any shape, such as a rectangle, polygon, or ellipse, and the size and area of ​​each through-hole 200 may differ from one another.

[0130] The IC card 1a of this embodiment, like the IC card 1 of the first embodiment, has inclined portions 112a and 122a on the conductive plate 100a that are bent relative to the flat portions 111a and 121a in cross-section. In the lamination process, such a conductive plate 100a is first bonded and fixed to the antenna holding layer 5 as described above, and then the antenna holding layer 5 and the antenna holding layer 6 are stacked on top of each other so as to sandwich the conductive plate 100a, and then pressed with heat and pressure. At this time, since the antenna holding layer 5 and the antenna holding layer 6 are subjected to compressive force along the thickness direction, it is conceivable that the inclined portions 112a and 122a of the conductive plate 100a are subjected to strong external force in a direction parallel to the flat portions 111a and 121a.

[0131] Here, if the rigidity of the conductive plate is low or the thickness is insufficient, the inclined portion of the conductive plate may be corrected, potentially reducing the inclination angle relative to the flat portion. However, in the conductive plate 100a of the IC card 1a of this embodiment, through holes 200 are appropriately provided in the inclined portions 112a and 122a. Therefore, when the antenna holding layer 5 and the antenna holding layer 6 are stacked and pressed with heat and pressure, the molten substrate can flow from the antenna holding layer 6 to the antenna holding layer 5 through the through holes 200. As a result, the external force acting on the inclined portions 112a and 122a of the conductive plate 100a in the direction parallel to the flat portions 111a and 121a is mitigated, and unintended deformations such as a decrease in the inclination angle of the inclined portions 112a and 122a of the conductive plate 100a during pressing can be suppressed.

[0132] As mentioned above, the shape and size of the through-holes provided in the conductive plate 100a are arbitrary, but if the outline of the through-hole is approximately circular, its diameter is preferably 0.3 mm or more and 1.0 mm or less, and if it is polygonal, it is preferable that the length of the longest part of the diagonal passing through its center is within the same range as above. By having the diameter of the through-hole and the length of the diagonal within the above range, when the antenna holding layer 5 and the antenna holding layer 6 are overlapped and pressed with heat and pressure, the molten substrate can be flowed smoothly from the antenna holding layer 6 to the antenna holding layer 5 through the through-hole 200.

[0133] As a result, the conductive plate 100a and the like can be laminated sandwiched between the antenna holding layer 5 and the antenna holding layer 6 while the inclined portions 112a and 122a maintain an appropriate inclination angle relative to the flat portions 111a and 121a. Therefore, in this embodiment, even if the milling tool approaches the conductive plate 100a, it is possible to reliably shift the contact point towards the center rather than the edge of the conductive plate 100a. This further improves the effect of suppressing the load that lifts the edge of the conductive plate 100a away from the card base 2a due to the cutting resistance of the milling tool.

[0134] 3. Third Embodiment of the Present Disclosure Next, as another example of an embodiment of the IC card of this disclosure, a third embodiment of IC card 1b will be described. This embodiment will also be described focusing on the differences from IC card 1 according to the first embodiment. Figure 8(a) is a diagram corresponding to Figure 2(b) that illustrates the cross-sectional shape of the conductive plate 100b (first plate 110b). Figure 8(b) is an enlarged view corresponding to Figure 5 that illustrates the details of the configuration of the first plate 110b in Figure 8(a).

[0135] As shown in Figures 8(a) and 8(b), in the third embodiment, the IC card 1b does not have inclined portions 112b on the +Y and -Y sides of the first plate 110b in a cross-sectional view including the thickness direction and the short side direction of the card base 2b, which is not inclined at a constant angle with respect to the flat portion 111b. The IC card 1b differs from the IC card 1 of the first embodiment in that the inclined portions 112b of the first plate 110b are inclined in a gentle curve with respect to the flat portion 111b according to a predetermined curvature. Conversely, except for this point, the configuration of the IC card 1b is the same as that of the IC card 1.

[0136] As shown in Figure 8(b), the inclined portion 112b at the upper end (+Y direction end) of the first plate 110b has an axis that is approximately arc-shaped. In other words, in a cross-sectional view including the thickness direction and the short side direction of the card base 2b, the inclined portion 112b extends in an approximately arc shape relative to the flat portion 111b. The radius of curvature of the arc of the axis of the inclined portion 112b is R1. Similarly, the inclined portion 112b at the lower end (-Y direction end) of the first plate 110b also has an axis that is approximately arc-shaped, and the radius of curvature of the arc of the axis is R2.

[0137] In this embodiment as well, as described in the first embodiment, in a cross-sectional view, the distance from the line passing through the edge of the flat portion 111b closest to the first recess 91 (recess 9) to the end of the edge of the inclined portion 112b closest to the first recess 91 in the +Y direction is defined as d12. Furthermore, the distance from the line passing through the edge of the flat portion 111b closest to the first recess 91 (recess 9) to the end of the edge of the inclined portion 112b closest to the first recess 91 in the -Y direction is defined as d22. The appropriate ranges for d12 and d22 in this case can be the same as the appropriate ranges for d11 and d21 in the first embodiment, because the same effects and advantages as in the first embodiment can be expected.

[0138] The IC card 1b of this embodiment, like the IC card 1 of the first embodiment, has an inclined portion 112b on the conductive plate 100b that is smoothly sloped in a substantially arc shape relative to the flat portion 111b in cross-sectional view. In the lamination process, such a conductive plate 100b is first bonded and fixed to the antenna holding layer 5 as described above, and then the antenna holding layer 5 and the antenna holding layer 6 are stacked on top of each other so as to sandwich the conductive plate 100b, and then pressed with heat and pressure. At this time, the antenna holding layer 5 and the antenna holding layer 6 are subjected to compressive force along the thickness direction, so the inclined portion 112b of the conductive plate 100b is subjected to an external force in a direction parallel to the flat portion 111b.

[0139] Here, if the conductive plate bends and tilts at a sharp angle between the flat portion and the inclined portion, it is conceivable that the influence of external forces on the inclined portion will be greater compared to when it is tilted at a shallower angle. In this case, if the rigidity of the conductive plate is low or the thickness is insufficient, the inclined portion of the conductive plate may be corrected, and the tilt angle with respect to the flat portion may decrease. However, in the conductive plate 100b of the IC card 1b of this embodiment, the change in the axis from the flat portion 111b to the inclined portion 112b is a gentle, approximately arc-shaped change, and the inclined portion 112b has a smooth, approximately arc-shaped incline with respect to the flat portion 111b. Therefore, it is possible to suppress the concentration of large external forces on the entire inclined portion 112b, and to uniformly distribute internal stress throughout the entire inclined portion 112b and the flat portion 111b. Thus, unintended deformation of the inclined portion 112b of the conductive plate 100b during pressing can be suppressed.

[0140] As a result, the conductive plate 100b and the like can be laminated sandwiched between the antenna holding layer 5 and the antenna holding layer 6 while the inclined portion 112b maintains an appropriate inclination relative to the flat portion 111b. Therefore, in this embodiment as well, when the milling tool approaches the conductive plate 100b, it is possible to reliably shift the contact point towards the center of the conductive plate 100b rather than the edge. This further improves the effect of suppressing the load that lifts the edge of the conductive plate 100b away from the card base 2b due to the cutting resistance of the milling tool. Although the configuration of the second plate is not mentioned in this embodiment, it goes without saying that the configuration of the second plate may be the same as that of the first plate 110b, as in the previous embodiments. This also applies to the fourth embodiment which will be described later.

[0141] 4. Fourth Embodiment of the Present Disclosure Next, as another example of an embodiment of the IC card of this disclosure, the IC card 1c of the fourth embodiment will be described. This embodiment will also be described focusing on the differences from the IC card 1 according to the first embodiment. Figure 9(a) is a diagram corresponding to Figure 2(b) that illustrates the cross-sectional shape of the conductive plate 100c (first plate 110c). Figure 9(b) is an enlarged view corresponding to Figure 5 that illustrates the details of the configuration of the first plate 110c in Figure 9(a).

[0142] As shown in Figures 9(a) and 9(b), in the fourth embodiment, the IC card 1c has inclined portions 112c on the +Y and -Y sides of the first plate 110c that are not bent and extended to be inclined relative to the flat portion 111c, in a cross-sectional view including the thickness direction and the short side direction of the card base 2c. The IC card 1c differs from the IC card 1 of the first embodiment in that the thickness of the inclined portion 112c is configured to gradually decrease as it moves away from the flat portion 111c. Conversely, except for this point, the configuration of the IC card 1c is the same as that of the IC card 1.

[0143] As shown in Figure 9(b), the inclined portion 112c at the upper end (+Y direction end) of the first plate 110c represents approximately right-angled triangular regions formed on both sides of the approximately rectangular region with a constant thickness, which is the region of the flat portion 111c. In other words, in a cross-sectional view including the thickness direction and the short side direction of the card base 2c, the conductive plate 100c, i.e., the first plate 110c, is a horizontally elongated trapezoid. This trapezoid has the contour line on the side closer to the recess 9 as the upper base and the contour line opposite to the contour line on the side closer to the recess 9 as the lower base. The flat portion 111c is the part that has the upper and lower bases as contour lines, and the inclined portion 112c is the part that has the hypotenuses excluding the upper and lower bases as contour lines. The other sides that form the contour line of the flat portion 111c can be considered in any way, but for example, they may be line segments along perpendicular lines drawn from the left and right ends of the upper base in the thickness direction. In this case, the inclined portion 112c may be considered as having its contour lines as the line segment and the left and right portions of the lower base that do not overlap with the flat portion 111c.

[0144] In the first plate 110c, one inclined portion 112c is extended such that the contour line of the inclined portion 112c on the +Y side, closer to the first recess 91, is formed along a straight line that is inclined in the -Z direction by an angle θ12 with respect to the axis of the flat portion 111c in a cross-sectional view. The other inclined portion 112c is extended such that the contour line of the inclined portion 112c on the -Y side, closer to the first recess 91, is formed along a straight line that is inclined in the -Z direction by an angle θ22 with respect to the axis of the flat portion 111c in a cross-sectional view.

[0145] On the other hand, in a cross-sectional view, d13 is defined as the distance from the straight line passing through the edge of the flat portion 111c closest to the first recess 91 to the end of the inclined portion 112c in the +Y direction. Furthermore, d23 is defined as the distance from the straight line passing through the edge of the flat portion 111c closest to the first recess 91 to the end of the inclined portion 112c in the -Y direction. The appropriate ranges for the inclination angles θ21 and θ22, and the appropriate ranges for the predetermined distances d13 and d23, can be the same as the appropriate ranges for θ11 and θ21, and d11 and d21, respectively, in the first embodiment. This is because the same effects and advantages as in the first embodiment can be expected.

[0146] The IC card 1c of this embodiment, like the IC card 1 of the first embodiment, has an inclined portion 112c on the conductive plate 100c, which is linearly inclined in cross-sectional view with respect to the flat portion 111c, with the thickness gradually decreasing as it moves away from the flat portion 111c. In other words, in the IC card 1c, the conductive plate 100c has a trapezoidal structure with the contour line on the side closer to the recess 9 as the upper base and the contour line opposite to the contour line on the side closer to the recess 9 as the lower base. Such a conductive plate 100c is bonded and fixed to the antenna holding layer 5 as described above, and then the antenna holding layer 5 and the antenna holding layer 6 are stacked on top of each other so as to sandwich the conductive plate 100c, etc., and pressed with heat and pressure. At this time, the antenna holding layer 5 and the antenna holding layer 6 are subjected to compressive force along the thickness direction, so the inclined portion 112c of the conductive plate 100c is subjected to an external force in a direction parallel to the flat portion 111c.

[0147] However, in the conductive plate 100c of the IC card 1c of this embodiment, the inclined portion 112c is not formed by bending relative to the flat portion 111c, and the thickness of both ends gradually decreases. Therefore, it is possible to suppress the concentration of a large external force on the entire inclined portion 112c. Thus, it is possible to suppress unintended deformation of the inclined portion 112c of the conductive plate 100c during pressing.

[0148] As a result, the conductive plate 100c and the like can be laminated sandwiched between the antenna holding layer 5 and the antenna holding layer 6 while the inclined portion 112c maintains an appropriate inclination relative to the flat portion 111c. Therefore, even in this embodiment, even if the milling tool approaches the conductive plate 100c, it is possible to reliably shift the contact point towards the center rather than the edge of the conductive plate 100c. This further improves the effect of suppressing the load that lifts the edge of the conductive plate 100c away from the card base 2c due to the cutting resistance of the milling tool.

[0149] Furthermore, embodiments that combine all or part of the above-described embodiments are also within the scope of this disclosure. For example, in the conductive plate 100b of the third embodiment and the conductive plate 100c of the fourth embodiment, through holes may be provided in the inclined portion, as in the conductive plate 100a of the second embodiment. This is because the effects of providing the through holes 200 in the conductive plate 100a of the second embodiment also apply to the third and fourth embodiments. Also, as is common to the conductive plates of the second to fourth embodiments, the inclined portion may be provided not only at both ends along the short side direction of the flat portion, but also at only one end. Moreover, when inclined portions are provided at both ends along the short side direction of the flat portion, it goes without saying that the shape of the conductive plate in cross-sectional view may or may not be symmetrical with respect to a straight line in the thickness direction. [Explanation of Symbols]

[0150] 1, 1a, 1b, 1c IC cards 2, 2a, 2b, 2c Card base 2p card base 3.8 Oversheet layer 4.7 Core Layer 5, 6 Antenna holding layer 9 recesses 11. Conductive adhesive layer 11a Conductive particles 11b Adhesive 12 Antenna Sheets 70 IC modules 71 External connection terminals 72 circuit boards 73a, 73b Antenna connection terminals 74 IC chip units 74a IC chip 74b Molding section 74p pad 75 wires 76 Bonding Holes 80 Antenna 83 Antenna wire 91 First recess 91a Bottom 92 Second recess 93 Outer circumference 93a, 93b sides 100 conductive plates 110, 110a, 110b, 110c First Plate 110p Plate 1 111, 111a, 111b, 111c flat part 112, 112a, 112b, 112c Slope 120, 120a Second Plate 120p Plate 2 121, 121a flat part 122, 122a Slope section 200 through holes 300 Milling Tools

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 wherein, in a cross-sectional view including the thickness direction and the short-side direction of the card base, the conductive plate comprises a flat portion along the short-side direction of the card base and an inclined portion extending from one or both ends of the flat portion and inclined toward the interior of the card base from the bottom surface of the recess relative to the flat portion.

2. The dual interface IC card according to claim 1, wherein, in a cross-sectional view including the thickness direction and the short side direction of the card base, the inclined portion extends so as to be inclined at a certain angle with respect to the flat portion.

3. The dual interface IC card according to claim 1, wherein in a cross-sectional view including the thickness direction and the short side direction of the card base, the inclined portion extends in a substantially arc shape relative to the flat portion.

4. The dual interface IC card according to claim 1, wherein in a cross-sectional view of the card base including the thickness direction and the short side direction, the conductive plate has a trapezoidal shape with the contour line on the side closer to the recess as the upper base and the contour line opposite to the contour line on the side closer to the recess as the lower base.

5. In a cross-sectional view of the card base including the thickness direction and the short side direction, when the inclination angle of the inclined portion with respect to the flat portion is θ, and the distance from the line passing through the side of the flat portion closest to the recess to the end of the side of the inclined portion closest to the recess is d, The dual interface IC card according to claim 2, wherein θ is 5° or more and 45° or less, and d is 0.03 mm or more and 0.10 mm or less.

6. A dual interface IC card according to any one of claims 1 to 5, wherein, in a cross-sectional view including the thickness direction and the short side direction of the card base, the inclined portion extends to both ends of the flat portion, and the shape of the conductive plate is symmetrical with respect to the thickness direction.

7. A dual interface IC card according to any one of claims 1 to 5, wherein, in a cross-sectional view including the thickness direction and the short side direction of the card base, a through hole is formed in the inclined portion.

8. 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 process in which the laminate formed by stacking the first substrate and the second substrate is punched out onto a card-sized card base, A recess forming step is to form a recess in the card base for embedding an IC module on the surface of the card base on the side where the opening of the recess is closer to the first substrate than to the second substrate, An IC module preparation step of preparing an IC module comprising a substrate, an IC chip disposed on one side of the substrate and a plurality of antenna connection terminals electrically connected to the IC chip, and an external connection terminal disposed on the other side of the substrate, electrically connected to the IC chip and exposed on the side of the card base where the recess is formed, An antenna connection step involves electrically connecting a plurality of antenna connection terminals and a plurality of conductive plates facing each other via a conductive adhesive layer, such that the IC chip and the antenna constitute a contactless communication circuit. The process includes an IC module bonding step of bonding the IC module to the recess of the card base, A method for manufacturing a dual-interface IC card, wherein, in a cross-sectional view including the thickness direction and the short-side direction of the card base, the conductive plate comprises a flat portion along the short-side direction of the card base and an inclined portion extending from one or both ends of the flat portion and inclined toward the interior of the card base from the bottom surface of the recess relative to the flat portion.

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