Dual-interface IC card and method for manufacturing the same

Abstract

To provide a dual interface IC card and a manufacturing method thereof which improve reliability of an electric connection between an IC module and an antenna line, widen a selection range of a conductive member for the electric connection, and facilitate machining.SOLUTION: A dual interface IC card 1 comprises: a card substrate 2 comprising a concave part 9; an antenna 80 which is arranged inside the card substrate, and comprises an antenna line and a plate-like end part 100, and with which a tip end of the antenna line and the plate-like end part 100 are electrically connected, respectively; and an IC module 70 having an IC chip. In the concave part 9, the plate-like end part 100 is at least partially exposed from the card substrate 2. The antenna 80 is arranged at an opening side of the concave part 9 with respect to the center of the card substrate 2, in a thickness direction of the card substrate 2. The tip end is electrically connected with the plate-like end part 100, on a surface to be turned to the opening side of the plate-like end part 100.SELECTED DRAWING: Figure 1

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.

Background Art

[0002] Conventionally, as an IC card, a contact IC card that inputs and outputs an electrical signal through an external connection terminal on the card surface, or a non-contact IC card that inputs and outputs an electrical signal by electromagnetic induction or the like through an antenna, has been used. In addition to these, a contact and non-contact shared IC card, that is, a dual interface IC card, which can realize both the function of a contact IC card and the function of a non-contact IC card with a single IC chip provided in the card, has also been used. Among them, the dual interface IC card can be used as a contact IC card effective for suppressing external leakage of input / output data during financial settlement, and can be used as a highly convenient non-contact IC card for data exchange in a proximity state when entering or leaving a room or for a ticket gate at a station. Therefore, the dual interface IC card is also becoming more popular in the market.

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

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

[0005] On the other hand, to avoid such problems, the contact terminal portion that electrically contacts the terminals of the IC module can be made of a metal plate, as described in Patent Document 2. This document describes a communication medium including a card substrate, an antenna wire embedded in the card substrate, an IC module embedded in the card substrate, and a metal plate embedded in the card substrate and electrically connected to the antenna wire and the IC module. In this case, the metal wire abuts against the first main surface, which is the lower surface of the metal plate, and extends along the first main surface, which is one of the first and second main surfaces that define the thickness direction of the metal plate. By making an electrical connection between the IC module and the antenna via such a metal plate, improvements in yield and workability can be expected compared to directly exposing the conductor.

[0006] Patent Document 2 describes connecting the antenna coil and metal plate by welding or the like before placing and attaching them to an intermediate sheet. However, this method results in an unstable loop shape for the antenna, making it difficult to obtain the desired electrical characteristics. Therefore, it is usually manufactured as follows: First, a metal plate is attached to one side of the base substrate of the antenna sheet. Next, the insulated conductor is embedded into the base substrate by heat and pressure, drawing a loop circuit and embedding the antenna wire. After that, both ends of the antenna wire are welded to the metal plate to complete the antenna sheet. To use this as a communication medium as described in Patent Document 2, it is necessary to position the antenna sheet so that one side of the base substrate of the antenna sheet faces downwards, that is, the antenna mounting surface of the base substrate faces away from the contact terminals of the IC module in the thickness direction of the communication medium, and then laminate it with other substrates.

[0007] Therefore, the depth from the surface of the card substrate on the side where the IC module is exposed to the metal plate is difficult to make shallower than a predetermined depth due to the constraint of the thickness of the antenna sheet. This is because, although it is possible to make the depth from the surface of the card substrate to the metal plate shallower by making the antenna sheet thinner, it becomes more difficult to stably embed the antenna wires into the base material as the base material becomes thinner. Consequently, since the distance in the thickness direction between the IC module and the metal plate cannot be shortened below a predetermined length, the reliability of the electrical connection between the IC module and the antenna depends heavily on the physical properties of the conductive adhesive or other material used to join them. As a result, it is difficult to improve the reliability of the electrical connection, and there is a problem in that the options for conductive adhesives and other materials are limited. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 2019-219732 [Patent Document 2] Japanese Patent Publication No. 2005-50326 [Overview of the project] [Problems that the invention aims to solve]

[0009] 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 improve the reliability of the electrical connection between the IC module and the antenna wire, broaden the range of selectable conductive materials for said electrical connection, and facilitate processing. [Means for solving the problem]

[0010] The dual-interface IC card according to this embodiment, which enables contact and contactless communication with external devices, comprises a card base having a recess, an antenna having an antenna wire and a plate-shaped end, the tip of the antenna wire and the plate-shaped end being electrically connected, and an IC module having an IC chip, wherein in the recess facing the IC module, the plate-shaped end is at least partially exposed from the card base toward the IC module, the antenna is positioned in the thickness direction of the card base toward the opening of the recess rather than the center of the card base, and the tip is electrically connected to the plate-shaped end on the surface of the end facing the opening.

[0011] Furthermore, in a dual-interface IC card according to another embodiment of this invention, the recess includes a first recess having a depth from the surface of the card base to a first depth, and a second recess formed closer to the center than the first recess and having a second depth greater than the first depth, wherein in a plan view, the plate-shaped end may be positioned in the region outside the second recess.

[0012] Furthermore, in a dual-interface IC card according to another embodiment of this invention, the recess further comprises a third recess adjacent to the first recess and located in an area outside the second recess, having a third depth that is deeper than the first recess and shallower than the second recess, wherein the plate-shaped end of the third recess is at least partially exposed from the card base.

[0013] Furthermore, a dual-interface IC card in another form of this implementation may have through holes provided at the plate-shaped ends.

[0014] Furthermore, in a dual-interface IC card according to another embodiment of this invention, the through-hole may be provided so as to avoid the portion of the plate-shaped end that faces the terminals of the IC chip.

[0015] Furthermore, in a dual-interface IC card according to another embodiment of this invention, the IC module may be electrically connected to each other via an anisotropic conductive film, with the terminals and plate-shaped ends facing each other being electrically connected.

[0016] Furthermore, in a dual-interface IC card according to another form of this implementation, the anisotropic conductive film may contain solder as conductive particles.

[0017] Furthermore, in a dual-interface IC card according to another embodiment of this invention, the plate-shaped end portion has a configuration in which a second member having conductivity and forming a surface facing the opening side, and a first member having insulating properties and forming a surface facing away from the opening side of the second member are stacked, and both the tip and the terminal may be electrically connected to the second member.

[0018] A method for manufacturing a dual-interface IC card capable of contact and contactless communication with external devices according to this embodiment comprises the steps of: preparing a first substrate, a second substrate, and an IC module having an IC chip and terminals electrically connected to the IC chip; forming an antenna consisting of an antenna wire and a plate-shaped end on one surface of the first substrate, and electrically connecting the tip of the antenna wire and the plate-shaped end, respectively; forming a laminate by laminating the first substrate and the second substrate by heat fusion or via adhesive so as to sandwich the antenna; forming a card base by punching the laminate to card size; forming a recess in the card base for embedding the IC module such that the plate-shaped end is at least partially exposed; and embedding the IC module in the recess and electrically connecting the terminals and the plate-shaped end facing each other, wherein the antenna is positioned in the thickness direction of the card base toward the opening side of the recess rather than the center of the card base, and the tip and the terminals are electrically connected to the plate-shaped end on the surface of the plate-shaped end facing the opening side.

Advantages of the Invention

[0019] According to the present embodiment, it is possible to improve the reliability of the electrical connection between the IC module and the antenna wire, expand the selection range of the conductive member for the electrical connection, and provide a dual interface IC card and a manufacturing method thereof that are easy to process.

Brief Description of the Drawings

[0020] [Figure 1] It is a plan view and a cross-sectional view for explaining the structure of the dual interface IC card according to the first embodiment. [Figure 2] It is a plan view and a cross-sectional view of the recess for embedding the IC module. [Figure 3] It is a diagram for explaining the connection of the IC module and the connection of the IC module and the antenna. [Figure 4] It is a cross-sectional view for explaining the structure of the dual interface IC card according to the second embodiment and a plan view of the recess for embedding the IC module. [Figure 5] It is a plan view for explaining the structure of the dual interface IC card according to the third embodiment. [Figure 6] It is a plan view for explaining the structure of the dual interface IC card according to the fourth embodiment. [Figure 7] It is a cross-sectional view for explaining the layer structure of the card substrate of the dual interface IC card according to the first embodiment.

Modes for Carrying Out the Invention

[0021] Hereinafter, an example of the dual interface IC card of the present disclosure will be described with reference to the drawings and the like. However, the dual interface IC card of the present disclosure is not limited to the embodiments and examples described below.

[0022] 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.

[0023] 1. First Embodiment An example of a first embodiment of the dual-interface IC card of this disclosure will be described. For the sake of explanation, an XYZ coordinate system will be set for the dual-interface IC card 1. First, as shown in Figures 1 and 2, the Z axis will be taken in the direction normal to the main surface of the dual-interface 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 will be defined as the +Z direction or upward in the thickness direction, and the opposite direction will be defined as the -Z direction or downward in the thickness direction.

[0024] Furthermore, when the dual interface IC card 1 is viewed from the +Z direction, the line perpendicular to both short sides of the dual interface 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 toward 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 toward the other long side is defined as the +Y direction or upward, and the opposite direction is defined as the -Y direction or downward.

[0025] Here, Figure 1(a) is a plan view of the dual interface IC card 1 as seen from the +Z direction. Figure 1(b) is a cross-sectional view of the dual interface IC card 1 of Figure 1(a), taken by cutting the area near the center of the external connection terminal 71 along the Y-axis with line AA along the X-axis, and viewed from the -Y direction. Figure 2(a) is an enlarged plan view of the recessed area 9 when the IC module 70 is removed from the dual interface IC card 1 of Figure 1(a). Figure 2(b) is a cross-sectional view similar to Figure 1(b), without the IC module 70 and conductive adhesive layer 11. For reference, the IC module 70 is shown with a dashed line to indicate its placement.

[0026] As shown in Figure 1(a), the dual-interface IC card 1 has the form of a thin, roughly rectangular plate with rounded corners when viewed from the +Z direction. On the surface of the dual-interface IC card on the +Z direction side, 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(b), 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 surface of the external connection terminal 71 on the +Z direction side is substantially flush with the surface of the card base 2 on the +Z direction side. This form of the dual-interface IC card 1 conforms to the international standard for IC cards, ISO / IEC 7816.

[0027] As shown in Figures 1(b) and 2(b), the card base 2 constituting the card body of the dual-interface IC card 1 is formed by stacking and integrating, in order when viewed from the -Z direction, an oversheet layer 8, an inner layer 7, antenna retaining layers 6 and 5, an inner layer 4, and an oversheet layer 3. Typically, the oversheet layers 8 and 3 are made of transparent substrates, and the inner layers 7 and 4, and the antenna retaining layers 6 and 5 are made of white substrates, but this is not limited to these. In addition, between the antenna retaining layers 6 and 5, the antenna wire 83 constituting the antenna 80 and the plate-shaped end 100, consisting of a first plate 110 and a second plate 120, are arranged so as to be sandwiched between them. The plate-shaped end is also simply referred to as the end.

[0028] The antenna wire 83 constituting this antenna 80 is embedded inside the card base 2, as shown by the dashed lines in Figures 1(a) and 2(a), and is not exposed from the recess 9. The antenna wire 83 is wound around the outer circumference of the roughly rectangular card, slightly inward, and both ends are electrically connected to the first plate 110 and the second plate 120, which are a pair of conductive plate-shaped ends 100. As shown in Figure 2(b), the first plate 110 has a structure in which a first member 111 and a second member 112 are stacked, and the surface of the second member 112 is exposed at the bottom surface 91a of the recess 9. However, this is just one example, and the first plate 110 and the second plate 120 may both be made of a single member, or they may both have a stacked structure of three or more different members.

[0029] In this embodiment, the first member 111 and the second member 112 are made of different metals, with the second member 112 being made of a metal that is less susceptible to oxidation than the first member 111. For example, the first member 111 may be made of copper and the second member 112 may be silver-plated, but this is not limited to this. The configuration of the second plate 120 is the same.

[0030] On the side of the IC module 70 facing the card base 2, terminals 73a and 73b are provided, which are electrically connected to the enclosed IC chip, as will be described later. As shown in Figure 1(b), terminal 73a is electrically connected to the first plate 110 via the conductive adhesive layer 11, and the IC module 70 is also mechanically joined to the card base 2 via the conductive adhesive layer 11. The conductive adhesive layer 11 is composed of a material containing conductive particles 11a such as solder and adhesive 11b. Here, the first plate 110 and the second plate 120 are arranged on the card base 2 such that the second member 112 faces the opening side of the recess 9, and the first member 111 faces the opposite side from the opening side of the recess 9. The opening side of the recess 9 is the +Z direction side in Figure 2(b).

[0031] The tip of the antenna wire 83 is in contact with the second member 112 on the +Z side of the first plate 110, thereby achieving an electrical connection with the first plate 110. Similarly, the terminal 73a of the IC module 70 is also in contact with the second member 112 of the first plate 110 via the conductive adhesive layer 11, thereby achieving an electrical connection with the first plate 110. As a result, the first plate 110 only needs to have the necessary conductivity on the side facing the second member 112, thus expanding the range of materials that can be selected for the first plate 110. These details regarding the first plate 110 and terminal 73a also apply to the second plate 120 and terminal 73b.

[0032] Furthermore, as shown in Figures 1(b) and 2(b), the antenna wire 83 and the first plate 110 constituting the antenna 80 are positioned in the thickness direction of the card base 2 on the +Z direction side, which is the opening side of the recess 9, relative to the straight line c1 parallel to the X-axis passing through the center of the card base 2. In other words, the antenna 80 is positioned in the thickness direction of the card base 2 on the opening side of the recess 9 relative to the center of the card base 2.

[0033] This reduces the internal stress on the antenna 80 when the card base 2 is subjected to external forces such as bending, compared to the case where the antenna 80 is positioned across the center of the card base 2 in the thickness direction, thereby improving the reliability of the dual-interface IC card 1. Furthermore, the first plate 110 can be positioned closer to the IC module 70 in the thickness direction of the card base 2. As a result, the distance of the conductive adhesive layer 11 in the thickness direction can be shortened, improving the reliability of the electrical connection between the IC module 70 and the antenna 80, simplifying the formation process and quality control process of the conductive adhesive layer 11, and making processing easier. The same can be said for the second plate 120.

[0034] As described above, the dual-interface IC card 1 of this embodiment, which is capable of contact and contactless communication with external devices, comprises a card base 2 having a recess 9, and an antenna wire 83 and a plate-shaped end 100 disposed inside the card base 2. The dual-interface IC card 1 also comprises an antenna 80 to which the tip of the antenna wire 83 and the plate-shaped end 100 are electrically connected, and an IC module 70 having an IC chip 74a and terminals 73a and 73b electrically connected to the IC chip 74a. The plate-shaped end 100 consists of a first plate 110 and a second plate 120.

[0035] In this configuration, the dual-interface IC card 1 has a plate-shaped end portion 100 that is at least partially exposed from the card base 2 toward the IC module 70 in a recess 9 facing the IC module 70. Furthermore, the IC module 70 is housed in the recess 9 such that the terminals 73a, 73b and the plate-shaped end portion 100, which face each other, are electrically connected. The antenna 80 is positioned in the thickness direction of the card base 2, on the opening side of the recess 9 rather than the center of the card base 2. In addition, the tip of the antenna wire 83 and the terminals 73a, 73b are electrically connected to the plate-shaped end portion 100 on the surface facing the opening side of the plate-shaped end portion 100.

[0036] The dual-interface IC card 1 has such a configuration, which improves the reliability of the electrical connection between the IC module and the antenna wire, expands the range of conductive materials that can be selected for the electrical connection, and simplifies manufacturing. The configuration of the dual-interface IC card 1 of this embodiment and the details of its manufacturing method are described below.

[0037] (a) Card base The card base 2 refers to the card body of the dual-interface IC card 1, excluding the IC module 70. As described above, the card base 2 typically has a structure in which an oversheet layer 8, an inner layer 7, antenna holding layers 6 and 5, an inner 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, wound in a loop shape and formed from a covered conductor or the like, is positioned between the antenna holding layers 6 and 5.

[0038] 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.

[0039] 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 the 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 plate-shaped end pieces 100 can be arranged depending on the number of ends of the antenna wire 83.

[0040] Furthermore, the layer configuration of the card base 2 is not limited to those described above; it may also be a three-layer configuration consisting of an oversheet layer, an antenna holding layer, and another oversheet layer, or a two-layer configuration consisting of an antenna holding layer and another antenna holding layer. Alternatively, the layer configuration of the card base 2 may be a multilayer configuration of seven or more layers, such as an oversheet layer, an antenna holding layer, a second inner layer, a first inner layer, a first inner layer, a second inner layer, an antenna holding layer, and an oversheet layer. In this case, the antenna 80 is positioned between the two first inner layers.

[0041] Furthermore, printing or a magnetic stripe may be embedded on the surface of the oversheet layer 3 or 8 or the inner layer 4 or 7 of the card base 2, and printing may also be applied to the adjacent surface between the inner layer 4 or 7 and the oversheet layer 3 or 8. Figure 7 is a cross-sectional view of the dual interface IC card 1 of Figure 1(a) when it is equipped with a magnetic stripe and a printed layer. The cross-section is cut along the CC line along the Y axis near the center in the direction along the X axis, and this cross-section is viewed from the -X direction. Thus, the dual interface IC card 1 may, for example, have a magnetic stripe 14 embedded on the surface of the oversheet layer 3 of the card base 2 opposite to the inner layer 4, and a printed layer 15 provided on the adjacent surface of the inner layer 4 to the oversheet layer 3. This enhances the design of the card and allows it to be used as a credit card that reads information from the magnetic stripe.

[0042] From the standpoint of conforming to standards such as ISO / IEC 7816, 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.

[0043] (i) Inner layer The inner layer is also called the core layer. A wide variety of white or colored plastic sheets can be used for inner 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 inner 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.

[0044] (ii) Antenna holding layer The antenna retaining layer is also called the core layer, similar to the inner 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 inner layers 4 and 7 can be used. The antenna retaining layers 5 and 6 may be made of the same material as the inner 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.

[0045] (iii) Oversheet layer For the oversheet layers 3 and 8, the same material as the inner layer and antenna retaining layer is usually used, but transparent materials with a thickness of approximately 0.05 mm or more and 0.10 mm or less are often used. From the viewpoint of preventing curling when the laminate of the inner layer, antenna retaining 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 inner layers 4 and 7 and the antenna retaining layers 5 and 6 mentioned above.

[0046] The material of the oversheet layer can be any material that adheres when heated, but even if the oversheet layer itself does not adhere when heated, the two can be integrated by adding a layer of a known adhesive that generates adhesive force when heated between the inner layer and the oversheet layer. Furthermore, when the dual interface 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 inner layers 4 and 7 by thermal transfer or the like.

[0047] (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 wire 83 constituting the antenna 80 are electrically connected to the first plate 110 and the second plate 120, which are plate-shaped conductive end portions 100. 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 6 facing the antenna holding layer 5 by applying heat and pressure or the like. At this time, adhesive may be applied to the surface of the antenna holding layer 6 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 terminals 73a and 73b of the IC module 70 when mounted.

[0048] 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 6 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 6. 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.

[0049] 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 6 (antenna sheet 12) on which the antenna 80 is formed is obtained. The intermediate product in which the antenna 80 is embedded in the antenna holding layer 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 dual interface 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.

[0050] (v) antenna In the antenna 80 formed in the antenna holding layer 5 or 6, the terminals 73a and 73b of the IC module 70 are electrically connected to the first plate 110 and the second plate 120, which are a pair of ends 100 to which multiple ends of the antenna wire 83 are electrically connected. In this way, the IC chip and antenna 80 of the IC module 70 constitute a contactless communication circuit. This communication circuit may perform proximity communication using, for example, the 13.56 MHz HF frequency band specified in ISO / IEC 18092 or ISO / IEC 144443. Alternatively, it may perform communication using other frequencies, such as the 920 MHz UHF frequency band, the 125 kHz LF frequency band, or the 2.45 GHz microwave frequency band.

[0051] When the dual-interface IC card 1 is held over an external device such as a reader / writer, the communication circuit generates an electromotive force or current due to the magnetic field or radio waves formed by the reader / writer, supplying power to the IC chip. This enables the IC chip 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.

[0052] 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 dual-interface IC card 1 can be manufactured at a lower cost compared to methods such as copper foil etching by using coated conductors. However, the dual-interface IC card 1 of this disclosure may also use antenna wires formed by copper foil etching or metal foil punching methods.

[0053] 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.

[0054] (vi) Ends (first plate and second plate) Next, the details of the configuration of the first plate 110 and the second plate 120, which are the conductive end portion 100, will be described. Both the first plate 110 and the second plate 120 are substantially rectangular plate-shaped members in a plan view along the Z-axis direction, which is the normal direction to the main surface of the dual interface IC card 1. As shown in Figure 2(a), the first plate 110 and the second plate 120 have, in this plan view, a region that overlaps with the first recess 91, that is, a region exposed from the card base 2, and a region located outside the first recess 91 and embedded inside the card base 2.

[0055] In other words, 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 with respect to the Y-axis 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.

[0056] Taking the first plate 110 as an example, the width of the first plate exposed from the card base 2 in the first recess 91 along the X-axis direction is W12, the same as the width of the first recess 91, and is narrower than the width W11 including the covering portion by the card base 2. Also, the height of the first plate exposed from the card base 2 in the first recess 91 along the Y-axis direction is W2. The sizes and ratios of W12, W11, and W2 are arbitrary, but it is preferable that the area of ​​the terminals 73a when the IC module 70 is mounted is included within the area of ​​the first plate 110 with a height of W2 and a width of W12. This is because a stable contact area for electrical connection between the terminals 73a and the first plate 110 can be obtained. The same applies to the second plate 120.

[0057] 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, the plates are less likely to detach from the card base 2 and become misaligned.

[0058] On the other hand, the positions of the +X-direction end of the first plate 110 and the -X-direction end of the second plate 120 are the same as the positions of the +X-direction and -X-direction ends of the first recess 91 that overlap them, respectively. That is, the +X-direction end of the first plate 110 and the -X-direction end of the second plate 120 before the formation of the recess 9 are positioned so as to extend into the inside of the second recess 92 in a plan view from the +Z direction. As will be described later, the second recess is a recessed area for housing an IC chip body, which is cut deeper than the first recess 91 that surrounds it. When the recess 9 is formed, the plate portion of the area of ​​the second recess 92 is cut away. In other words, in the plan view, the first plate 110 and the second plate 120 after the cutting of the recess 9 are positioned in the area outside the second recess 92.

[0059] To put it another way, the recess 9 includes a first recess 91 whose depth from the surface of the card base 2 is a first depth, and a second recess 92 which is formed closer to the center than the first recess 91 and has a second depth that is deeper than the first depth. In a plan view along the Z-axis, the multiple ends 100 are located in the region outside the second recess 92.

[0060] By having the first plate 110 and the second plate 120 in this arrangement and size, even if there is a misalignment of the plate's position along the X-axis, the contact area with the terminals 73a and 73b of the IC module 70 can be reliably secured. However, the +X-side end of the first plate 110 may be shifted to the -X-side than the +X-side end of the overlapping first recess 91, and the -X-side end of the second plate 120 may be shifted to the +X-side than the -X-side end of the overlapping first recess 91. However, if the thickness of the IC chip body is sufficiently thin, the second recess 92 may be the same depth as the first recess, and it is not necessarily required to provide a second recess with a different depth than the first recess.

[0061] Furthermore, as mentioned above, the first plate 110 and the second plate 120 have a laminated structure including at least two layers: a first member 111 and a second member 112 laminated on the +Z side of the first member 111. In this case, it is preferable that the second member 112 is a material that is less susceptible to oxidation than the first member 111. A material that is less susceptible to oxidation can be rephrased as, for example, if both the first member 111 and the second member 112 are metals, then the second member 112 is a metal with a lower ionization tendency than the first member 111. As an example of such metals, the first member 111 can be aluminum, iron, nickel, or copper, and the second member 112 can be silver, palladium, platinum, or gold.

[0062] Furthermore, the first member 111 and the second member 112 are not limited to members composed of a single metal, but may also be alloys or non-metallic members such as carbon. In such cases, the relative resistance to oxidation of the first member 111 and the second member 112 may be calculated from the mixing ratio of the metals of each member, or it may be determined experimentally.

[0063] Furthermore, the first plate 110 and the second plate 120 may have a laminated structure of three or more layers, further comprising layers of different materials other than the first member 111 and the second member 112. For example, the first member, the third member, and the second member may be laminated in this order from the -Z direction to the +Z direction. In this case, it is preferable that the second member is less susceptible to oxidation than either the first member or the third member. This is because if the second member is more susceptible to oxidation than either the first member or the third member, it becomes difficult to achieve the effects of this disclosure. As a suitable example of such a material, for instance, the first member may be made of copper, the third member may be nickel-plated, and the second member may be gold-plated.

[0064] Considering the ease of material procurement, cost, processability, and electrical properties, it is preferable to use highly conductive copper as the first component 111 and silver plating as the second component 112 among those listed above. This is because by using copper, which can ensure sufficient conductivity, as the first component 111, and using silver, which is resistant to oxidation and easily exposes the metal interface when cutting the resin layer with an end mill, as the plating for the second component 112, it is possible to obtain good electrical properties and processability while suppressing cost increases.

[0065] On the other hand, the first plate 110 and the second plate 120 do not have the laminated structure of two or three or more layers described above, and 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 material 111 and the second material 112, 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.

[0066] Furthermore, in the case of the two-layer configuration of the first member 111 and the second member 112 described above, the second member may be a conductive material such as metal, and the first member may be an insulating material. In other words, the plate-shaped end portion 100 may have a configuration in which a conductive second member 112, which forms a surface facing the opening side of the recess 9, and an insulating first member 111, which forms a surface facing the opposite side of the opening side of the second member 112, are laminated together. For example, the first member 111 may be a heat-resistant flexible material such as glass epoxy or polyimide, and the second member 112 may be formed from the aforementioned metal as metal foil or metal plating. Alternatively, the second member 112 may be formed from a conductive non-metallic film such as graphite film.

[0067] By arranging the first plate 110 and the second plate 120 in a two-layer structure consisting of an insulating first member 111 and a conductive second member 112, the following effects can be considered. First, compared to the case where the entire first plate 110 and the second plate 120 are composed of materials with high conductivity and thermal conductivity, their heat capacity can be reduced. Therefore, when the IC module 70 is heated from the side of the external connection terminal 71 to electrically connect the IC module 70 to the antenna 80 and mechanically connect it to the card base 2, thermal deformation of the card base 2, etc., can be suppressed.

[0068] Furthermore, compared to the case where the entire first plate 110 and second plate 120 are made of metal, the range of material selection is expanded, and it is easier to impart the necessary conductivity only to the necessary parts. Moreover, compared to the case where the entire first plate 110 and second plate 120 are made of metal, the flexibility of the card base 2 when bent can be increased, so the internal stress due to bending of the card can be distributed, and damage to the card base 2 can be suppressed.

[0069] In this embodiment, the first plate 110 and the second plate 120 are constructed as a laminate of a first member 111 and a second member 112 that is less susceptible to oxidation than the first member 111. Furthermore, the tip and terminals 73a and 73b of the antenna wire 83 are electrically connected to the first plate 110 and the second plate 120, facing the second member 112. While we do not wish to be constrained by theory, the following can be considered as an example of the effects of this configuration.

[0070] For example, if the second member 112 is made of a material that is less susceptible to oxidation than the first member 111, the amount of oxide film formed on the surface of the second member 112 will be less than when the surface of the first member 111 is exposed. Therefore, when the second member 112 and the tip of the antenna wire 83 are joined by welding, the amount of impurities interposed between them is small, resulting in good welding. Also, if both the first member 111 and the second member 112 were made of copper, when welding the second member 112 and the antenna wire 83, the heat from welding would escape to the copper of the second member 112, which has high thermal conductivity, potentially leading to welding defects or longer welding times. However, by providing the second member 112, which has lower thermal conductivity than the copper of the first member 111, with silver plating or the like, welding efficiency and welding yield can be improved.

[0071] On the other hand, consider sandwiching the first plate 110 and the second plate 120 between resin substrates such as antenna holding layers 5 and 6 and heat-pressing them. In this case, depending on the type of resin substrate, if a sufficient oxide film is formed on the surface of the first plate 110 and the second plate 120, hydrogen bonds are more easily formed between the resin substrate and the oxide film. As a result, the first plate 110 and the second plate 120 become more strongly bonded to the resin substrate. Conversely, if almost no oxide film is formed on the surface of the first plate 110 and the second plate 120, and the metal surface is almost completely exposed, the adhesive strength between the resin substrate and the first plate 110 and the second plate 120 is considered to be very weak. Furthermore, regarding the wettability of the surface of the first plate 110 and the second plate 120, the wettability tends to be higher if there are no foreign substances such as oxide films attached to the surface.

[0072] When solder is applied to the surfaces of the first and second plates, the residual state of the solder, i.e., the wettability, will differ depending on whether the surface is made of copper, which easily forms an oxide film, or silver plating, which does not easily form an oxide film. This also applies when an anisotropic conductive film (ACF) or anisotropic conductive paste (ACP) containing solder or other metal particles is interposed between the terminals 73a and 73b of the IC module 70 and the first and second plates 110 and 120, which are the ends 100 of the antenna 80. In other words, the less oxide film there is on the surfaces of the first and second plates 110 and 120, and the higher the wettability, the more reliable the electrical connection between the IC chip and the antenna 80 can be when the IC module 70 is embedded in the recess 9 of the card base 2 via the ACF or ACP.

[0073] Furthermore, as shown in Figures 1(b) and 2(b), the antenna wire 83 and the first plate 110 constituting the antenna 80 are positioned in the thickness direction of the card base 2 on the +Z direction side, which is the opening side of the recess 9, relative to the straight line c1 parallel to the X-axis passing through the center of the card base 2. In other words, the antenna 80 is positioned in the thickness direction of the card base 2 on the opening side of the recess 9 relative to the center of the card base 2.

[0074] This reduces the internal stress on the antenna 80 when the card base 2 is subjected to external forces such as bending, compared to the case where the antenna 80 is positioned across the center of the card base 2 in the thickness direction of the card base 2. This can be explained as follows. In Figure 1(b), assume that the cross-section of the dual interface IC card 1 has a nearly uniform density distribution overall. Here, assume that the dual interface IC card 1 is bent along an axis parallel to the Y-axis such that its left and right ends flex in the -Z direction.

[0075] In this case, the cross-section of the dual-interface IC card 1 cut in the YZ plane is a rectangle of the same area regardless of the X coordinate. Therefore, when bent, the bending stress is distributed such that, on the +Z side of the line c1, the tensile stress along the X axis increases as you move away from the line c1, and on the -Z side of the line c1, the compressive stress along the X axis increases as you move away from the line c1.

[0076] Therefore, if the antenna wire 83 and end portion 100 are positioned across the straight line c1, which is the center of the card base 2, in the thickness direction of the card base 2, the antenna wire 83 and conductive adhesive layer 11 will be divided into parts that receive tensile stress and parts that receive compressive stress. In other words, the antenna wire 83 and conductive adhesive layer 11 will be subjected to different types of stress internally, making them prone to deformation and cohesive failure. However, in this embodiment, the antenna wire 83 and end portion 100 are positioned off-center to the +Z direction from the straight line c1, which is the center of the card base 2, in the thickness direction of the card base 2. Therefore, the antenna wire 83 and conductive adhesive layer 11 will only receive the same type of tensile stress, and the difference in stress between each part can be reduced. Thus, deformation and cohesive failure can be made less likely to occur in the antenna wire 83 and conductive adhesive layer 11.

[0077] Furthermore, with the configuration described above, the antenna wire 83 in the dual-interface IC card 1 is positioned closer to the opening side of the recess 9 in the thickness direction of the card base 2. Therefore, when the dual-interface IC card 1 performs contactless communication using proximity technology (such as NFC), the distance between the antenna wire 83 and the reader / writer is reduced, improving communication sensitivity. Moreover, because the antenna wire 83 is positioned further away, the smoothness of the surface where the external connection terminal 71 of the dual-interface IC card 1 is not exposed is increased, improving the quality of thermal transfer printing of facial images, text, etc., onto that surface.

[0078] Incidentally, in the prior art, as described in Patent Document 2 above, the tip of the antenna wire and the end of the antenna (metal plate) are electrically connected on the side of the end of the antenna that faces away from the opening side of the recess provided in the card base. Also, the terminals of the IC module and the end of the antenna are electrically connected on the side of the end of the antenna that faces the opening side of the recess provided in the card base. In this case, the antenna is generally positioned in the center of the card base in the thickness direction of the card base.

[0079] This stems from the fact that, in conventional technology, it was considered preferable to position foreign objects such as antenna wires and ends as close to the center of the card base as possible in the thickness direction of the card base. In other words, it was thought that by positioning the foreign objects at the center in the thickness direction of the card base and laminating the other resin substrates symmetrically from top to bottom, symmetry in the thickness direction of the components could be ensured, and warping of the card due to heating processes, etc., could be suppressed.

[0080] However, while card warping can be suppressed to some extent by adjusting the material composition and thickness of the laminated resin substrate, the electrical connection between the IC module and the antenna end is the most important factor in terms of card manufacturing load and quality assurance, yet the design prioritized the former. Therefore, as mentioned above, the design of connecting the antenna to the lower side of the plate makes it difficult to shorten the distance from the surface of the card base to the plate beyond a certain limit. Reducing the burden of controlling the formation conditions and quality control of the conductive adhesive layer that makes an electrical connection between the IC module and the end of the antenna had become difficult.

[0081] In the conventional method of manufacturing the card, as described above, first a metal plate is attached to one side of the base substrate of the antenna sheet, and then a loop circuit is drawn while embedding the insulated wires into the base substrate by heat and pressure, thereby embedding the antenna wires. After that, the antenna sheet is completed by welding both ends of the antenna wires to the metal plate. Next, the antenna sheet is positioned so that one side of the base substrate of the antenna sheet faces downwards, that is, the antenna mounting surface of the base substrate faces away from the external connection terminals of the IC module in the thickness direction of the communication medium, and then laminated with other substrates.

[0082] Therefore, the depth from the surface of the card substrate on the side where the IC module is exposed to the metal plate is difficult to make shallower than a predetermined depth due to the constraint of the thickness of the antenna sheet. This is because, although it is possible to make the depth from the surface of the card substrate to the metal plate shallower by making the antenna sheet thinner, it becomes more difficult to stably embed the antenna wires into the base material as the base material becomes thinner.

[0083] In contrast, this disclosure deliberately removes the constraint of placing the antenna near the center of the card base, and instead places the antenna on the opening side of the recess rather than the center of the card base in the thickness direction. Furthermore, the tip of the antenna wire and the terminals of the IC module are electrically connected to the plate-shaped end of the antenna on the surface of the plate-shaped end of the antenna facing the opening side of the recess of the card base.

[0084] This reduces the internal stress on the antenna when the card base is subjected to external forces such as bending, compared to when the antenna is positioned across the center of the card base in the thickness direction, thereby improving the reliability of the electrical connection. Furthermore, the edges of the card base can be positioned closer to the IC module in the thickness direction. As a result, the distance of the conductive adhesive layer in the thickness direction can be shortened, improving the reliability of the electrical connection between the IC module and the antenna, simplifying the formation process and quality control process of the conductive adhesive layer, and making processing easier.

[0085] In this embodiment, the antenna 80 is positioned on the opening side of the recess 9 rather than the center of the card base 2 in the thickness direction of the card base 2. However, for the reasons mentioned above, it is preferable that the plate-shaped end portion 100 and antenna wire 83 constituting the antenna 80 be positioned as close as possible to the opening side of the recess 9 rather than the center of the card base 2. For example, when the thickness of the card base 2 is t, the distance of the antenna 80 from the surface on the opening side of the recess 9 of the card base 2 is preferably 0.05t or more and 0.4t or less, and more preferably 0.1t or more and 0.3t or less. The former range expands the range of materials that can be used for the conductive adhesive layer 11. The latter range allows relatively thin materials such as ACF to be used for the conductive adhesive layer 11, enabling both electrical and mechanical connections with the same adhesive layer, thereby reducing the burden on manufacturing and quality control.

[0086] (b) IC module Next, the main components of the IC module 70 will be described, primarily based on Figures 1(b) and 3. Figure 3(a) is a view of the IC module 70 from the +Z direction, towards the external connection terminal 71, similar to Figure 1(a). Figure 3(b) is a view of the IC module 70 from the -Z direction, opposite to that of Figure 3(a). Here, most of the molded portion 74b of the IC chip body 74 is omitted in order to allow for a view of the interior. Figure 3(c) is an enlarged cross-sectional view of section B near terminal 73a in Figure 1(b).

[0087] The IC module 70 is embedded in a recess 9 formed in the card base 2, and 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, thereby forming a contactless communication circuit. At this time, contact communication with a contact-type reader / writer, etc., can be performed through the external connection terminal 71 provided on the IC module 70.

[0088] 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 an adhesive, and leaving some of the copper foil bonded to the resin film to form a predetermined pattern. Specifically, the process involves sequentially applying a photosensitive material, placing a film plate with the predetermined pattern, exposure, and etching away the non-photosensitive areas, so that an external connection terminal 71 is formed on one copper foil surface of the resin film and terminals 73a and 73b are formed on the other copper foil surface. This forms a substrate 72 in which some of the copper foil with the predetermined pattern remains on both sides of the resin film. In addition, the substrate 72 is pre-provided with multiple bonding holes 76, which are through holes for wire bonding to the external connection terminal 71.

[0089] As shown in Figure 3(a), the external connection terminal 71 has defined sections for each external terminal as defined by the ISO / IEC 7816-2 standard. Each of these sections and the IC chip 74a are connected by wires 75, such as gold wire, through the bonding holes 76 provided in the substrate 72, as shown in Figure 3(b). Similarly, terminals 73a and 73b are connected to the IC chip 74a by wires 75. These bonding holes 76 and wires 75 are covered and protected by the molded section 74b.

[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] (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 3(c), the conductive adhesive layer 11 is a liquid or tape-like material that is placed between the first plate 110 and the substrate 72 of the IC module 70 and the terminals 73a formed on the substrate 72.

[0093] The conductive adhesive layer 11 may be applied and 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 and attached to the bottom surface 91a of the card base 2 after cutting the recess 9.

[0094] 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.

[0095] However, the conductive adhesive layer 11 may be applied and attached to cover only the areas of 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.

[0096] 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 entire back surface of the substrate 72 of the IC module 70 can be heat-laminated with ACF, 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.

[0097] 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 3(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 may be resin coated with nickel or gold, or solder particles. Various types of solder particles such as SnPb, SnAgCu, SnCu, SnZnBi, SnAgInBi, SnZnAl, etc., or alloys of these with other metals can be used. These configurations are the same even when ACP is used.

[0098] 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 terminals 73a formed on the substrate 72, is compressed.

[0099] 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 first plate 110 and the terminal 73a, and the conductive particles 11a of the conductive adhesive layer 11 in this portion are pressed against the first plate 110 and the terminal 73a along the thickness direction of the conductive adhesive layer 11. Furthermore, if the conductive particles 11a are small, the conductive particles 11a overlap in a chain-like fashion from the first plate 110 to the terminal 73a along the thickness direction of the conductive adhesive layer 11. In other words, electrical conductivity is established between the first plate 110 and the terminal 73a via the conductive particles 11a.

[0100] On the other hand, in the areas of the substrate 72 where terminals 73a are not present, the conductive particles 11a are not compressed to the extent that they are pressed against the first plate 110 and terminals 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.

[0101] (d) Method for manufacturing a dual interface IC card Next, an example of a method for manufacturing a dual-interface IC card 1 using the card base 2, IC module 70, and conductive adhesive layer 11 described above will be explained.

[0102] First, the plate-shaped end portions 100, namely the first plate 110 and the second plate 120, are bonded to the surface of either the antenna retaining layer 5 or 6, on the side not adjacent to the inner layer 4 or 7. Both may be bonded and fixed to the surface of the antenna retaining layer 5 or 6 via adhesive. Next, a covered 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 retaining layer 5 or 6 where the end portion 100 is formed, starting from one of the first plate 110 and the second plate 120 and ending at the other. At the start and end 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.

[0103] Specifically, for example, while applying a predetermined heat and pressure to the antenna holding layer 6, 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 6. At this time, the antenna holding layer 6 may also be referred to as the first substrate.

[0104] Next, as shown in Figures 1(b) and 2(b), the oversheet layer 8, inner layer 7, antenna holding layers 6 and 5, inner 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 vertically and horizontally 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 surface of, for example, the antenna holding layer 6 so as to be sandwiched between the antenna holding layers 5 and 6. At this time, the antenna holding layer 5, which is positioned opposite the antenna holding layer 6, 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.

[0105] 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, inner 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.

[0106] 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 to form card base material 2 that conforms to the ISO / IEC 7816 card size. A recess 9 for embedding the IC module 70 is then formed in the card base material 2 by cutting with an end mill. This results in the cut card base material 2. As previously mentioned, the recess 9 consists of two stages: a first recess 91 with a first depth for housing the flat substrate 72 of the IC module 70, and a second recess 92 with a second depth deeper than the first recess 91 for housing the convex IC chip body 74. The bottom surface 91a of the first recess 91 of the card base material 2 exposes the surfaces of the first plate 110 and the second plate 120.

[0107] 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. Typically, a module tape is used as the IC module 70, in which the IC modules 70 are formed continuously on a long tape 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.

[0108] 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. This melts the conductive adhesive layer 11 made of ACF, thereby establishing an electrical connection between the terminals 73a and 73b of the IC module 70 and the first plate 110 and the second plate 120, as well as a mechanical connection between the IC module 70 and the card base 2. Depending on the type and composition of the ACF, there are differences in the time and heat and pressure conditions to be applied, but as an example, the time can be 0.5 seconds or more and 10.0 seconds or less, the temperature can be 150°C or more and 250°C or less, and the pressure can be 20 MPa or more and 100 MPa or less.

[0109] (e) Regarding the dual interface IC card of the first embodiment In summary, in the dual-interface IC card 1 of the first embodiment, which is capable of contact and contactless communication with external devices, the plate-shaped end portion 100 is composed of a first plate 110 and a second plate 120. The antenna 80 can be configured in a relatively simple manner, with both ends of the antenna wire 83 electrically connected to the end portion 100 of the said layer configuration, and the manufacturing of the card base 2 with this embedded inside is also relatively easy.

[0110] Furthermore, the dual-interface IC card 1 includes an IC module 70 having an IC chip 74a and terminals 73a and 73b electrically connected to the IC chip 74a. In the recess 9 of the card base 2 facing the IC module 70, the plate-shaped end portion 100 is at least partially exposed from the card base 2 toward the IC module, and the antenna 80 is positioned in the thickness direction of the card base 2 toward the opening of the recess 9 rather than the center of the card base 2. In addition, the tip of the antenna 80 and terminals 73a and 73b are electrically connected to the plate-shaped end portion 100 on the surface of the plate-shaped end portion 100 facing the opening side of the plate-shaped end portion 100.

[0111] This reduces the internal stress on the antenna 80 when the card base 2 is subjected to external forces such as bending, thereby improving the reliability of the dual-interface IC card 1. Furthermore, since the plate-shaped end portion 100 can be positioned close to the IC module 70 in the thickness direction of the card base 2, the distance of the conductive adhesive layer 11 in the thickness direction can be shortened. As a result, the reliability of the electrical connection between the IC module 70 and the antenna 80 can be improved, the range of selectable conductive materials for the electrical connection can be expanded, and processing can be simplified.

[0112] 2. Second Embodiment Next, a dual-interface IC card according to the second embodiment of this disclosure will be described.

[0113] Figure 4(a) is a cross-sectional view of the dual-interface IC card 1a of the second embodiment, corresponding to Figure 1(b). Figure 4(b) is a plan view corresponding to Figure 2(a). In this embodiment, the configuration of the antenna 80, including the configuration of the end portion 100, is the same as in the first embodiment, but the configuration of the recess 9a is different from that of the first embodiment. Specifically, in a plan view from the +Z direction, the recess 9a is adjacent to the first recess 91b and located in the area outside the second recess 92, and further comprises a third recess 94 which has a third depth that is deeper than the first depth of the first recess 91b and shallower than the second depth of the second recess 92.

[0114] In the plan view, the third recess 94 is separated into a third recess 94a that overlaps with the first plate 110 and a third recess 94b that overlaps with the second plate 120. Furthermore, in the third recess 94a facing the IC module 70, the first plate 110a facing the terminals 73a of the IC module 70 when mounted is at least partially exposed from the card base 2a toward the IC module 70. The same applies to the third recess 94b, where the second plate 120 facing the terminals 73b of the IC module 70 when mounted is at least partially exposed from the card base 2a.

[0115] In this embodiment, in the plan view, the widths of the third recesses 94a and 94b along the Y-axis are formed to be approximately the same as, or greater than, the widths of the first plate 110 and the second plate 120 along the Y-axis. In other words, the first plate 110 and the second plate 120 are exposed throughout the entire area of ​​the third recesses 94a and 94b. In this way, even if the positions of the third recesses 94a and 94b and the positions of the first plate 110 and the second plate 120 are misaligned, it is expected that the first plate 110 and the second plate 120 will be exposed with approximately the same area throughout the entire area of ​​the third recesses 94a and 94b. As a result, a decrease in the reliability of the electrical connection between the IC module 70 and the antenna 80 can be suppressed. However, the widths of the third recesses 94a and 94b along the Y-axis may be formed to be smaller than the widths of the first plate 110 and the second plate 120 along the Y-axis.

[0116] The dual-interface IC card 1a of this embodiment has the following advantages. Specifically, the distance between the substrate 72 (excluding terminals 73a and 73b) and the card base 2a can be determined independently of the distance between terminals 73a and 73b of the IC module 70 and the first plate 110 and the second plate 120. Therefore, the distance setting for optimal electrical connection between terminals 73a and 73b of the IC module 70 and the first plate 110 and the second plate 120, and the distance setting for optimal mechanical connection between the IC module 70 and the card base 2a can be optimized individually.

[0117] For example, in this embodiment, the third recesses 94a and 94b are filled with a conductive adhesive layer 11, which is a conductive paste or solder paste in which silver particles are dispersed as a filler in epoxy resin. In the first recess 91b, an adhesive layer 13 is used between the card base 2a and the substrate 72 of the IC module 70, which is a thermoplastic, thermosetting, or other adhesive that does not have conductivity. Since the third recesses 94a and 94b are formed deeper than the first recess 91, even if a liquid conductive adhesive is used in the third recesses 94a and 94b, it is possible to suppress it from overflowing into the first recess 91b.

[0118] However, the disclosure is not limited thereto, and an anisotropic conductive film (ACF) may be used as a common conductive adhesive layer 11 spanning the first recess 91b and the third recesses 94a and 94b, similar to the first embodiment. In this case as well, the distance setting for optimal electrical connection between the terminals 73a and 73b of the IC module 70 and the first plate 110 and the second plate 120, and the distance setting for optimal mechanical connection between the IC module 70 and the card base 2a can be changed. As a result, both optimal electrical connection and optimal mechanical connection can be achieved with the same conductive adhesive layer 11.

[0119] 3. Third Embodiment Next, a dual-interface IC card according to a third embodiment of this disclosure will be described.

[0120] Figure 5 is a plan view showing the configuration near the recess 9 corresponding to Figure 2(a) for the dual interface IC card 1b of the third embodiment. The dual interface IC card 1b of this embodiment differs from the first and second embodiments in the configuration of the first plate 110a and the second plate 120a that constitute the end 100a of the antenna 80a. Specifically, the first plate 110a and the second plate 120a have a plurality of through holes 113, 114, 123, and 124 along the X axis direction at their +Y direction end and -Y direction end, respectively, in the area exposed by the first recess 91.

[0121] However, the first plate 110a and the second plate 120a may have only one through hole, and the shape of the through hole is not limited to a circle in plan view, but can be any shape such as an oval, ellipse, square, or star. Furthermore, the positions of the through holes formed in the first plate 110a and the second plate 120a may be arranged one or more times along the Y axis at the -X side end and the +X side end, respectively, within the area exposed by the first recess 91.

[0122] In this configuration, the dual-interface IC card 1b of this embodiment melts during lamination processes such as heat pressing, and the resin substrates such as the antenna holding layer 6 beneath the first plate 110a and the second plate 120a enter the through-hole. As a result, the first plate 110a and the second plate 120a are strongly supported by the antenna holding layers 5 and 6 that sandwich them, and by the anchoring effect through the through-hole. Consequently, problems such as the first plate 110a and the second plate 120a detaching from the antenna holding layer or becoming misaligned during machining of the recess 9 can be suppressed.

[0123] There are no particular restrictions on the arrangement or size of the through holes 113 at the +Y direction end and 114 at the -Y direction end of the exposed area of ​​the first plate 110a, and the through holes 123 at the +Y direction end and 124 at the -Y direction end of the exposed area of ​​the second plate 120a. However, it is preferable that these through holes be provided in a plan view from the +Z direction, avoiding the portions of the first plate 110a and the second plate 120a that face the terminals 73a and 73b of the IC module 70 when mounted.

[0124] This suppresses the reduction in the electrical contact area between the end portion 100a and the terminals 73a and 73b, improving the reliability of their electrical connection. Furthermore, it prevents the resin substrate above the through hole from coming into close contact with the first plate 110a and the second plate 120a during machining. As a result, even when the cutting is performed slightly shallower than the surface of the first plate 110a and the second plate 120a, the surface of the first plate 110a and the second plate 120a can be expected to be well exposed.

[0125] In this embodiment, the conductive paste 11c described above may be used as the conductive adhesive layer 11, and a non-conductive adhesive layer 13 may be used for bonding between the card base 2b and the substrate 72 of the IC module 70. Alternatively, an anisotropic conductive film (ACF) may be used as the conductive adhesive layer 11.

[0126] 4. Fourth Embodiment Next, a dual-interface IC card according to the fourth embodiment of this disclosure will be described.

[0127] Figure 6 is a plan view showing the configuration near the recess 9 corresponding to Figure 2(a) for the dual interface IC card 1c of the fourth embodiment. In this embodiment, the configuration of the antenna 80a, including the configuration of the end portion 100a, is the same as in the third embodiment, but the configuration of the recess 9b is similar to that of the second embodiment. That is, in a plan view from the +Z direction side, the recess 9b is adjacent to the first recess 91c and located in the area outside the second recess 92, and further comprises a third recess 95 which has a third depth that is deeper than the first depth, which is the depth of the first recess 91c, and shallower than the second depth, which is the depth of the second recess 92.

[0128] In the plan view, the third recess 95 is separated into a third recess 95a that overlaps with the first plate 110a and a third recess 95b that overlaps with the second plate 120a. Furthermore, in the third recess 95a facing the IC module 70, the first plate 110a facing the terminals 73a of the IC module 70 when mounted is at least partially exposed from the card base 2c toward the IC module 70. However, the +Y side end and the -Y side end of the first plate 110a are covered by the card base 2c, forming covered areas 84a and 84b, respectively.

[0129] In other words, the two opposing ends of the first plate 110a along the Y-axis are embedded in the card base 2c at the first recess 91c, and the portion of the first plate 110a sandwiched between these ends is exposed from the card base 2c at the third recess 95a. The second plate 120a is the same as described above, except that terminal 73a is replaced with terminal 73b, the third recess 94a is replaced with the third recess 95a, and covering areas 84a and 84b are replaced with covering areas 85a and 85b.

[0130] This embodiment assumes that the +Y-direction end and the -Y-direction end of the first plate 110a are covered by the card base 2c. However, the disclosure is not limited to this, and the two opposing ends of the first plate 110a along the X-axis may be embedded in the card base 2c in the first recess 91c, and the portion of the first plate 110a sandwiched between these ends may be exposed from the card base 2c in the third recess 95a. Alternatively, both the two opposing ends of the first plate 110a along the X-axis and the two opposing ends along the Y-axis may be embedded in the card base 2c in the first recess 91c. In this case, the portion of the first plate 110a sandwiched between both ends may be exposed from the card base 2c in the third recess 95a.

[0131] In either case, the first plate 110a and the second plate 120a in the region overlapping with terminals 73a and 73b in a plan view from the +Z direction only need to be exposed by the third recesses 95a and 95b. Therefore, even if the first plate 110a and the second plate 120a are covered by the card base 2c in the first recess 91c in any other region, the effects and advantages of this embodiment can be obtained similarly.

[0132] In this embodiment, in the plan view, the widths of the third recesses 95a and 95b along the Y-axis are shorter than the widths of the first plate 110a and the second plate 120a along the Y-axis. In other words, both ends of the first plate 110a and the second plate 120a extend further along the Y-axis than the areas exposed in the third recesses 95a and 95b of the first plate 110a and the second plate 120a. These extended portions are embedded in the card base 2c on the -Z direction side of the first recess 91c, forming covered areas 84a, 84b, 85a, and 85b. Within the embedded areas, the first plate 110a and the second plate 120a are provided with a plurality of through holes 113, 114, 123, and 124, similar to those in the third embodiment.

[0133] As a result of the configuration of the dual-interface IC card 1c of this embodiment, the following effects can be obtained in addition to the points described in the third embodiment. Specifically, both ends of the first plate 110a and the second plate 120a along the Y-axis are embedded in the card base 2c. Therefore, the first plate 110a and the second plate 120a, sandwiched between the antenna holding layers 5 and 6, are firmly supported at both ends by the resin substrate. Thus, problems such as the first plate 110a and the second plate 120a detaching from the antenna holding layers and becoming misaligned can be further suppressed.

[0134] In this embodiment, a conductive paste 11c may be used as the conductive adhesive layer 11 for the third recesses 94a and 94b, and a non-conductive adhesive layer 13 may be used for the first recess 91b. Alternatively, an anisotropic conductive film (ACF) may be used as the common conductive adhesive layer 11 spanning the first recess 91b and the third recesses 94a and 94b.

[0135] The embodiments and their modifications described herein can be combined in whole or in part, as long as they do not create a contradiction, and such combinations are naturally included in this disclosure. [Explanation of symbols]

[0136] 1, 1a, 1b, 1c Dual Interface IC Card 2, 2a, 2b, 2c Card base 3.8 Oversheet layer 4, 7 Inner layer 5, 6 Antenna holding layer 9, 9a recess 11. Conductive adhesive layer 11a Conductive particles 11b Adhesive 11c conductive paste 12 Antenna Sheets 13 Adhesive layer 14 Magnetic Stripe 15 Printing layer 70 IC modules 71 External connection terminals 72 circuit boards 73a, 73b terminal 74 IC chip units 74a IC chip 74b Molded section 74p pad 75 wires 76 Bonding Holes 80, 80a antenna 83 Antenna wire Covered areas 84a, 84b, 85a, 85b 91, 91b, 91c First recess 91a Bottom 92 Second recess 93 Outer circumference 93a, 93b sides 94, 94a, 94b Third recess 95, 95a, 95b Third recess 100, 100a end 110, 110a First Plate 111 First Member 112 Second Member 113, 114, 123, 124 through holes 120, 120a Second Plate

Claims

1. A dual-interface IC card capable of contact and contactless communication with external devices, A card base with a recess, Antenna wire and plate-shaped end, The tip of the antenna wire and the plate-shaped end are electrically connected to an antenna, An IC module having an IC chip, In the recess facing the IC module, the plate-shaped end is at least partially exposed from the card base toward the IC module. The antenna is positioned in the thickness direction of the card base on the side of the opening of the recess that is closer to the center of the card base. The plate-shaped end has a structure in which a second member having conductivity and forming a surface facing the opening side and a first member having conductivity and forming a surface facing away from the opening side of the second member are laminated together, and the second member is less susceptible to oxidation than the first member. A dual-interface IC card in which the tip contacts the second member, thereby electrically connecting with the plate-shaped end on the surface of the end facing the opening side.

2. The recess includes a first recess having a depth from the surface of the card base having a first depth, and a second recess formed closer to the center than the first recess and having a second depth that is deeper than the first depth. In a plan view, the plate-shaped end is positioned in the region outside the second recess, as described in claim 1, for the dual interface IC card.

3. The recess further comprises a third recess adjacent to the first recess and located in the region outside the second recess, having a third depth that is deeper than the first recess and shallower than the second recess. The dual interface IC card according to claim 2, wherein in the third recess, the plate-shaped end is at least partially exposed from the card base.

4. A dual interface IC card according to any one of claims 1 to 3, wherein a through hole is provided at the end.

5. The dual interface IC card according to claim 4, wherein the through-hole is provided so as to avoid the portion of the plate-shaped end that faces the terminals of the IC module.

6. The dual interface IC card according to any one of claims 1 to 5, wherein the terminals and plate-shaped ends of the IC modules facing each other are electrically connected via an anisotropic conductive film.

7. The dual interface IC card according to claim 6, wherein the anisotropic conductive film includes solder as conductive particles.

8. A method for manufacturing a dual-interface IC card that enables contact and contactless communication with external devices, A step of preparing a first substrate, a second substrate, and an IC module having an IC chip and a plurality of terminals electrically connected to the IC chip, The process involves forming an antenna on one surface of the first substrate, comprising an antenna wire and a plate-shaped end, and electrically connecting the tip of the antenna wire and the plate-shaped end, respectively. A step of forming a laminate by laminating the first substrate and the second substrate so as to sandwich the antenna, either by heat fusion or via an adhesive, The process of punching out the laminated material to card size to form a card base, The steps include forming a recess in the card base for embedding the IC module such that the plate-shaped end is at least partially exposed, The process includes embedding the IC module in the recess and electrically connecting the terminals of the IC module and the plate-shaped end to each other, The antenna is positioned in the thickness direction of the card base on the side of the opening of the recess that is closer to the center of the card base. A method for manufacturing a dual interface IC card, comprising a configuration in which a second member having conductivity and forming a surface facing the opening side of the second member is laminated, and the tip of the second member is brought into contact with the second member, thereby electrically connecting the surface of the end facing the opening side of the plate-shaped end which is less susceptible to oxidation than the first member.

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