Dual interface IC card and IC module

Abstract

To provide a dual interface IC card in which a composition can be simplified while securing durability as an IC card, and an IC module used for the same.SOLUTION: An IC card 1 comprises: a card base body 2 in which a recess 9 is formed; an IC module 70; and an antenna 80. The IC module 70 includes: a substrate 72; an IC chip 74a; and an external connection terminal 71 composed of a first terminal used for contact communication and a second terminal used for contactless communication. The antenna 80 includes: an antenna line 83; and a conductive plate 100 which is a capacitance forming unit located at the tip and electrically connected to the antenna line 83. The second terminal and the capacitance forming unit are respectively capacitance coupled, and thereby the IC chip 74a and the antenna 80 form a closed circuit. The external connection terminal 71 is exposed to a face where the recess 9 of the card base body 2 is formed. The capacitance forming unit is superimposed at least in part with the second terminal, and not superimposed with the first terminal.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a dual interface IC card capable of contact and non-contact communication with an external device, and an IC module used therefor. [Background technology]

[0002] Conventional IC cards include contact IC cards, which input and output electrical signals through an external connection terminal on the card surface, and contactless IC cards, which input and output electrical signals through an antenna via electromagnetic induction, etc. In addition to these, dual-interface IC cards, which combine the functions of both contact and contactless IC cards with a single IC chip, are also in use. Dual-interface IC cards, in particular, can be used as contact IC cards, which are effective in preventing external leakage of input and output data during financial transactions, and as highly convenient contactless IC cards, which allow data to be exchanged in close proximity when entering and exiting a room or using a ticket gate at a station. For this reason, dual-interface IC cards are becoming increasingly popular in the market.

[0003] Incidentally, typical conventional dual interface IC cards are exemplified, for example, in Patent Document 1 and Patent Document 2 below. Patent Document 1 describes a contact and contactless IC card having an external device connection terminal, an antenna coil embedded in the card base, and an antenna coil connection terminal. In this contact and contactless IC card, the contact surface of the IC module in the IC module mounting recess formed in the card base is cut so that the antenna coil connection terminal is exposed. Furthermore, the connection between the IC module-side antenna coil connection terminal, which is fitted into the recess from outside the base and mounted therein, and the base-side antenna coil connection terminal are bonded to the contact surface of the IC module using only a conductive adhesive material.

[0004] When the connection between the antenna coil connection terminal on the IC module side and the antenna coil connection terminal on the card base side is made with a conductive adhesive material, external forces, such as repeated bending of the IC card, can cause the connection portion of the conductive adhesive material to break or the adhesive interface to peel off. To improve durability against such external forces, booster antenna technology is sometimes used, which establishes an electrical connection between the IC module and the antenna on the card base side without a physical connection between them. This technology establishes an electrical connection by arranging a coil connected to the IC chip on the IC module side and a coil connected to the antenna on the card base side facing each other but at a distance from each other.

[0005] As an example of such a communication medium, Patent Document 2 describes a communication medium including a predetermined IC module including an IC chip having a communication terminal and a first coupling coil, and a substrate on which the IC module is mounted, the IC chip including a second coupling coil and an antenna connected in series with the second coupling coil. The IC chip includes a non-contact communication unit and a contact communication unit, both having communication terminals. The second coupling coil is disposed outside the first coupling coil so as to be electromagnetically coupled to the first coupling coil.

[0006] The IC card described in Patent Document 2 is expected to have improved durability and reliability against external forces such as bending, compared to Patent Document 1. However, in an IC card using a booster antenna system such as that described in Patent Document 2, it is necessary to provide a coil for contactless communication on the IC module side as well, which complicates the structure of the IC module. Furthermore, the antenna configuration also becomes complicated, as it requires a coil facing the coil on the IC module side for the antenna on the card base side, which may lead to an increase in component costs and manufacturing costs for the entire IC card. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-182017 [Patent Document 2] Japanese Patent Application Laid-Open No. 2016-12255 Summary of the Invention [Problem to be solved by the invention]

[0008] The present disclosure has been made in consideration of these circumstances, and aims to provide a dual interface IC card and an IC module for use with the IC card that can simplify the configuration of the IC module and card base compared to conventional technology while ensuring the durability of the IC card. [Means for solving the problem]

[0009] A first configuration of a dual interface IC card according to this embodiment, capable of contact communication and contactless communication with an external device, comprises a card base having a recess formed therein, 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 an external connection terminal disposed on the other side of the substrate, electrically connected to the IC chip, and consisting of a plurality of first terminals used for the contact communication and a plurality of second terminals used for the contactless communication, wherein the antenna comprises an antenna wire and a plurality of capacitance forming portions disposed at the tip of the antenna wire and electrically connected to the antenna wire, wherein the plurality of second terminals and the plurality of capacitance forming portions are capacitively coupled to each other, thereby forming a closed circuit between the IC chip and the antenna, and the external connection terminal is exposed on the surface of the card base where the recess is formed, and when viewed in plan from that surface, the capacitance forming portion at least partially overlaps the second terminal but does not overlap the first terminal.

[0010] In addition, a second configuration of a dual interface IC card according to another embodiment of the present invention is such that, in the first configuration described above, the second terminal may be any of a C4 terminal, a C8 terminal, or a C6 terminal as specified in ISO / IEC 7816-2.

[0011] Furthermore, a third configuration of a dual interface IC card according to another embodiment of the present invention may be such that, in the first or second configuration described above, the capacitance generating portion is a conductive plate.

[0012] In addition, a fourth configuration of a dual interface IC card according to another form of this embodiment may be such that, in the first configuration or the second configuration, the capacitance forming portion is a bellows wiring portion in which the tip of the antenna wire has a repeated folded structure.

[0013] In addition, a fifth configuration of a dual interface IC card according to another form of this embodiment is the third configuration, wherein the plurality of conductive plates are composed of a first conductive plate that is arranged at one end of the antenna line and electrically connected to the antenna line, and a second conductive plate and a third conductive plate that are arranged at the other branched end of the antenna line and electrically connected to the antenna line, and when viewed in a plane from the surface, the first conductive plate, the second conductive plate, and the third conductive plate may at least partially overlap with the second terminal, which is any one of a C4 terminal, a C8 terminal, and a C6 terminal defined in ISO / IEC 7816-2 that are different from each other.

[0014] In a sixth configuration of an IC module used in a dual interface IC card capable of contact communication and contactless communication with an external device according to this embodiment, the IC module comprises a substrate, an IC chip arranged on one side of the substrate, and an external connection terminal arranged on the other side of the substrate, electrically connected to the IC chip, and consisting of a plurality of first terminals used for the contact communication and a plurality of second terminals used for the contactless communication, and when viewed in a plane from the other side, a plurality of capacitance forming portions corresponding to the second terminals are arranged in an area that at least partially overlaps with the second terminals but does not overlap with the first terminals, and when an antenna is arranged in which the plurality of capacitance forming portions are electrically connected to each other by an antenna wire, the plurality of second terminals and the plurality of capacitance forming portions are each capacitively coupled, causing the IC chip and the antenna to form a closed circuit. [Effects of the Invention]

[0015] According to this embodiment, it is possible to provide a dual interface IC card and an IC module for use with the IC card, which can simplify the configuration of the IC module and card base compared to conventional technology while ensuring the durability of the IC card. [Brief explanation of the drawings]

[0016] [Figure 1] 1A and 1B are a plan view and a cross-sectional view illustrating the structure of a dual-interface IC card according to a first embodiment. [Figure 2] 1 is a plan view of the vicinity of a recess, illustrating the arrangement of conductive plates in the dual interface IC card according to the first embodiment. FIG. [Figure 3] FIG. 2 is a diagram illustrating the configuration of an IC module. [Figure 4] 1 is an equivalent circuit diagram of a dual-interface IC card according to a first embodiment. [Figure 5] 10A and 10B are plan views illustrating the structure of a dual-interface IC card according to a second embodiment and a plan view of the vicinity of a recessed portion illustrating the arrangement of a conductive plate. [Figure 6] 10A and 10B are a plan view and a cross-sectional view illustrating the structure of a dual-interface IC card according to a third embodiment. [Figure 7] FIG. 11 is a plan view of the vicinity of a recess, illustrating the arrangement of a bellows wiring section of a dual interface IC card according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0017] An example of a dual interface IC card according to the present disclosure will be described below with reference to the drawings, etc. However, the dual interface IC card according to the present disclosure is not limited to the embodiments and examples described below.

[0018] The figures shown below are schematic illustrations. Therefore, the size and shape of each part are appropriately exaggerated to facilitate understanding. Furthermore, hatching indicating the cross section of a member is omitted as appropriate in each figure. The numerical values ​​such as dimensions of each member and the names of materials described in this specification are examples of embodiments and are not limited to these, and may be selected and used as appropriate. In this specification, terms specifying shapes or geometric conditions, such as parallel, orthogonal, and perpendicular, are intended to include not only their strict meanings but also substantially the same state.

[0019] 1. First embodiment of the present disclosure An example of a typical first embodiment of a dual interface IC card of the present disclosure will be described. Here, for convenience of explanation, an XYZ coordinate system is set for IC card 1. IC card 1 is a dual interface IC card. As shown in FIGS. 1(a) and 1(b), the Z axis is taken as the normal direction to the main surface of IC card 1. The direction from the main surface on which external connection terminals 71 of IC module 70 are not arranged to the main surface on which external connection terminals 71 are arranged 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.

[0020] When the IC card 1 is viewed from the +Z direction, the line perpendicular to both short sides of the IC card 1 and the Z axis is defined as the X axis, 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 rightward direction, and the opposite direction is defined as the -X direction or leftward direction. Furthermore, the axis perpendicular to the X and Z axes is defined as the Y axis, 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 direction, and the opposite direction is defined as the -Y direction or downward direction.

[0021] Here, Figure 1(a) is a plan view of the IC card 1 as viewed from the +Z direction, and Figure 1(b) is a cross-sectional view of the IC card 1 of Figure 1(a) taken along line AA along the X-axis near the bottom end of the IC module 70 as viewed from the -Y direction.

[0022] Fig. 2(a) is an enlarged plan view of the vicinity of recess 9 of card base 2 with IC module 70 removed, and Fig. 2(b) is an enlarged plan view of the vicinity of recess 9 of IC card 1 with IC module 70 embedded. Fig. 3 is an explanatory diagram of IC module 70, with Fig. 3(a) being an enlarged view of the vicinity of IC module 70 when IC card 1 is viewed from the +Z direction, and Fig. 3(b) being a view of IC module 70 when viewed from the -Z direction opposite to Fig. 3(a). Fig. 3(c) is a diagram corresponding to Fig. 3(b) and explaining the configuration of an IC module 70p according to the prior art.

[0023] As shown in FIG. 1(a), IC card 1 has the form of a thin, generally rectangular plate with rounded corners in a plan view from the +Z direction. Furthermore, on the surface of the dual-interface IC card on the +Z direction side, an IC module 70 including external connection terminals 71 is disposed 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 FIG. 1(b), IC module 70 is embedded in a recess 9 formed in card base 2, and is disposed so that the surface on the +Z direction side of external connection terminals 71 is exposed on approximately the same plane as the surface on the +Z direction side of card base 2. This form of IC card 1 complies with ISO / IEC 7816, the international IC card standard.

[0024] As shown in FIG. 1(b), the card base 2 constituting the card body of the IC card 1 is formed by laminating and integrating, in order from the -Z direction, an over-sheet layer 8, a core layer 7, antenna support layers 6 and 5, a core layer 4, and an over-sheet layer 3. Typically, the over-sheet layers 3 and 8 are transparent substrates, and the core layers 4 and 7 and the antenna support layers 5 and 6 are white substrates, but this is not limited thereto. Between the antenna support layers 6 and 5, a first conductive plate 110 is disposed as a conductive plate 100, which serves as an antenna wire 83 and an end portion of the antenna 80, sandwiched between the two. As shown in FIG. 1(a), the conductive plate 100 is disposed near the bottom end of the recess 9 along the X-axis direction as the first conductive plate 110 on the -X direction side and the second conductive plate 120 on the +X direction side, in a plan view from the +Z direction.

[0025] The conductive plate 100 is one form of the capacitance forming portion in the present disclosure. As will be described later, the capacitance forming portion is a section of the external connection terminal 71 of the IC module 70 that is not used for contact communication and functions as a predetermined capacitance element in combination with a terminal c electrically connected to the IC chip. In this embodiment, examples of terminals that are not used for contact communication and electrically connected to the IC chip include the C4 terminal and the C8 terminal.

[0026] The capacitance-forming portion having such a function is not limited to being a conductive plate, and may be, for example, a portion having a so-called bellows structure in which the antenna line 83 has a structure in which it is repeatedly folded along the Y-axis direction and continuously arranged in the X-axis direction. This is called a bellows wiring portion. In other words, the capacitance-forming portion may be a conductive plate or a bellows wiring portion. In the latter case, the bellows structure of the antenna line allows it to function as a pseudo-capacitance element similar to a conductive plate. In this disclosure, the first and second embodiments exemplify a capacitance-forming portion that is a conductive plate, and the third embodiment exemplifies a capacitance-forming portion that is a bellows wiring portion.

[0027] 1(a) , the antenna wire 83 constituting the antenna 80 is disposed inside the card base 2. The antenna wire 83 is wound one or more times around the periphery of the substantially rectangular card, and a pair of conductive plates 100, a first conductive plate 110 and a second conductive plate 120, are formed on both ends of the antenna wire 83. In other words, the antenna wire 83 and the pair of conductive plates 100 are electrically connected to each other.

[0028] As shown in FIG. 1(b), an adhesive layer 11, which is a liquid or tape-like adhesive, is disposed between the substrate 72 of the IC module 70 and the card base 2 on which the recess 9 is formed. The IC module 70 and the card base 2 are bonded to each other via the adhesive layer 11. The external connection terminals 71 of the IC module 70 are exposed on the surface of the card base 2 on which the recess 9 is formed. As shown in FIG. 2(b), when viewed in plan from the +Z direction, the conductive plate 100 is positioned so as to at least partially overlap the C4 terminal or C8 terminal, which is an unused terminal according to the standard. Furthermore, the conductive plate 100 is positioned so as not to overlap terminals used for contact communication according to the standard, such as the C1 terminal, C2 terminal, C3 terminal, C5 terminal, and C7 terminal.

[0029] In this embodiment, as shown in Fig. 2(b), the first conductive plate 110 of the conductive plate 100 overlaps with a portion of the C4 terminal in the section of the external connection terminal 71 of the IC module 70. Furthermore, the second conductive plate 120 of the conductive plate 100 overlaps with a portion of the C8 terminal in the section of the external connection terminal 71 of the IC module 70. In other words, the C4 terminal of the external connection terminal 71 and the first conductive plate 110 form an electrostatic capacitance (hereinafter simply referred to as capacitance) component shown as capacitance CD2 in the equivalent circuit diagram of Fig. 4. Furthermore, the C8 terminal of the external connection terminal 71 and the second conductive plate 120 form a capacitance component shown as capacitance CD3.

[0030] As a result, the IC chip 74a built into the IC module 70 and the antenna 80 built into the card base 2 form a closed circuit as shown in Fig. 4. The equivalent circuit diagram in Fig. 4 shows that the IC card 1 forms a closed circuit in which the resistance R1 and capacitance CD1 in the IC chip 74a are connected in parallel to a series circuit of inductance L1 and capacitances CD2 and CD3 formed by the antenna 80. As a result, if each element is set so that the inductance, capacitance, and resistance have appropriate values, the IC card 1 will be able to communicate contactlessly with external devices.

[0031] Furthermore, conductive plate 100 is positioned so as not to overlap with terminals C1, C2, C3, C5, and C7 used in contact communication. This prevents parasitic capacitance from accidentally occurring between conductive plate 100 and the terminals used in contact communication while IC card 1 is performing contactless communication, which could result in unexpected power consumption for contact communication and cause problems in contactless communication.

[0032] The IC card 1 of this embodiment, which is a dual-interface IC card capable of contact and contactless communication with external devices, has the above-described configuration. This allows electrical connection between the IC module 70 and the antenna 80 without a physical connection, ensuring the durability of the IC card. Furthermore, since there is no need to provide any additional coils on the IC module 70 or the card base 2, the configurations of the IC module 70 and the card base 2 can be simplified compared to the conventional booster antenna type technology.

[0033] The configuration of an IC card 1, which is a dual interface IC card according to this embodiment, and a method for manufacturing the same will be described in detail below.

[0034] (a) Card base The card base 2 refers to the card body excluding the IC module 70 that constitutes the IC card 1. As described above, the card base 2 typically has a configuration in which an over-sheet layer 8, a core layer 7, antenna support layers 6 and 5, a core layer 4, and an over-sheet layer 3 are laminated in this order from one end on the −Z direction side in the thickness direction.

[0035] Furthermore, a first conductive plate 110 and a second conductive plate 120 are arranged between the antenna support layers 6 and 5, sandwiched between the antenna wire 83 that constitutes the antenna 80 and the plate-shaped end portion of the conductive plate 100. The card base 2 may refer to both the card before the recess 9 is formed and the card after the recess 9 is formed, and may refer to both the card without the antenna 80 and the card with the antenna 80. The first conductive plate 110 and the second conductive plate 120 that constitute the pair of conductive plates 100 are arranged along the X-axis direction when viewed from the recess 9 as a reference, and are electrically connected to both ends of the antenna wire 83 of the antenna 80, respectively.

[0036] For ease of explanation, in this embodiment, the antenna wire 83 of the antenna 80 is described as a single conductor wire wound in a loop shape without branches, but the present disclosure is not limited to this and includes antenna wires 83 that are appropriately branched and have three or more ends. Also, three or more conductive plates 100 can be arranged depending on the number of ends of the antenna wires 83.

[0037] The layer structure of the card base 2 is not limited to the above, and may be a three-layer structure of an oversheet layer, a core layer, and an oversheet layer, or a two-layer structure of a core layer and a core layer. Alternatively, the layer structure of the card base 2 may be a multi-layer structure of seven or more layers, such as an oversheet layer, a core layer, a second antenna support layer, a first antenna support layer, a second antenna support layer, a core layer, and an oversheet layer. In this case, the antenna 80 may be disposed at the interface between any of the core layers, the first antenna support layer, and the second antenna support layer and another layer. Furthermore, printing or an embedded magnetic stripe may be provided on the surface of the oversheet layer 3 or 8 of the card base 2 opposite the core layer 4 or 7, or printing may be provided on the surface of the core layer 4 or 7 adjacent to the oversheet layer 3 or 8.

[0038] 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 may be outside this range.

[0039] (i) Core layer A wide variety of white or colored plastic sheets can be used for the core layers 4 and 7, including the following single films or composite films: 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, ABS, polyacrylic ester, polypropylene, polyethylene, polyurethane, etc. The thickness of the core layers 4 and 7 can be selected appropriately taking into account the overall thickness of the card, but can be, for example, approximately 0.10 mm or more and 0.38 mm or less.

[0040] (ii) Antenna support layer The antenna support layer is a layer made of the same material as the core layer and is located closer to the center in the thickness direction than the core layer. Antenna support layers 5 and 6 can be made of a wide variety of plastic sheets, similar to those used for core layers 4 and 7. Antenna support layers 5 and 6 may be made of the same material as core layers 4 and 7, or may be made of a different material. The thickness of antenna support layers 5 and 6 can be selected appropriately taking into account the overall thickness of the card, and can be, for example, approximately 0.10 mm or more and 0.38 mm or less.

[0041] (iii) Oversheet layer The over-sheet layers 3 and 8 are typically made of the same material as the core layer and antenna support layer, but a transparent material with a thickness of approximately 0.05 mm to 0.10 mm is often used. From the viewpoint of preventing curling when the laminate of the antenna support layer, core layer, and over-sheet layer is integrated by heat pressing or the like, it is preferable that the over-sheet layers 3 and 8 have the same thickness, but they do not necessarily have to be the same. This also applies to the core layers 4 and 7 and the antenna support layers 5 and 6 described above.

[0042] The material of the over-sheet layers 3 and 8 may be any material that is adhesive when heated, but even if the over-sheet layer itself is not easily adhesive when heated, the core layer and the over-sheet layer can be integrated by additionally forming a layer of a known adhesive that generates adhesive force when heated between them. Furthermore, when the IC card 1 is used as a magnetic card, a magnetic stripe may be embedded in advance by thermal transfer or the like on the main surface opposite to both or one of the core layers 4 and 7 for either or both of the over-sheet layers 3 and 8.

[0043] (iv) Antenna sheet In this embodiment, the antenna 80 is formed on one surface of the antenna support layer 6 facing the antenna support layer 5, and both ends of an antenna wire 83 constituting the antenna 80 are electrically connected to the conductive plate 100. The formation of the antenna 80 on the antenna support layer 6 is performed, for example, as follows. First, the first conductive plate 110 and the second conductive plate 120 are adhesively fixed to the surface of the antenna support layer 6 before lamination, facing the antenna support layer 5, by applying heat and pressure or the like. At this time, an adhesive may be applied to the surface of the antenna support layer 6 before the first conductive plate 110 and the second conductive plate 120 are arranged.

[0044] The first conductive plate 110 and the second conductive plate 120 are arranged side by side in the left-right direction corresponding to the intended mounting position of the IC module 70. At least a portion of the first conductive plate 110 and the second conductive plate 120 are arranged to overlap the C4 terminal and the C8 terminal, respectively, which are sections of the external connection terminal 71 of the IC module 70 when mounted. However, the first conductive plate 110 and the second conductive plate 120 are arranged so as not to overlap the C1 terminal, C2 terminal, C3 terminal, C5 terminal, and C7 terminal, which are sections of the external connection terminal 71.

[0045] Thereafter, the tip of the antenna wire 83 is welded to either the first conductive plate 110 or the second conductive plate 120. Then, starting from this point, a predetermined heat pressure is applied to the antenna wire 83, and the antenna wire 83, which is a coated conductor covered with an insulating material, is embedded in the surface of the antenna support layer 6 using a wire winding former. That is, while applying a predetermined heat pressure to the antenna wire 83, an antenna supply head is drawn into a loop shape as shown in FIG. 1( a), and the antenna wire 83 supplied from the antenna supply head is sequentially embedded in the antenna support layer 6. After embedding, the antenna wire 83 is cut, and the tip of the cut antenna wire 83 is welded to the other of the first conductive plate 110 or the second conductive plate 120, with the end point being used.

[0046] In this way, an antenna support layer 6 (antenna sheet 14) on which the antenna 80 is formed is obtained. The intermediate product in which the antenna 80 is embedded in the antenna support layer 6 is sometimes referred to as an antenna sheet 14. The antenna sheet 14 can be distributed on the market by itself as a component for manufacturing an IC card 1, which is a dual interface IC card. Alternatively, a commercial model may exist in which a sheet material such as the antenna support layer 6 is supplied to a processor, who processes it into an antenna sheet 14 and delivers it to the supplier.

[0047] (v) Antenna In the antenna 80 formed on the antenna support layer 6, a pair of conductive plates 100 to which multiple tips of the antenna wire 83 are electrically connected form a capacitance component with the external connection terminal 71 of the IC module 70, which is disposed at a predetermined distance apart along the thickness direction of the card body 2. Specifically, the first conductive plate 110 and the C4 terminal, which is a section of the external connection terminal 71, are disposed to face each other and are separated by a predetermined distance. The first conductive plate 110, which is a conductive plate disposed opposite to each other, and the C4 terminal of the external connection terminal 71 form a type of capacitor. The same applies to the second conductive plate 120 and the C8 terminal, which is a section of the external connection terminal 71.

[0048] As a result, the IC chip 74a and antenna 80 included in the IC module 70 form a closed circuit in which the capacitance component formed by the first conductive plate 110 and the C4 terminal and the capacitance component formed by the second conductive plate 120 and the C8 terminal are connected in series between them. As a result, the IC card 1 forms a communication circuit for contactless communication using the IC chip 74a and the antenna 80. The communication circuit may be one that performs close-proximity communication using, for example, the 13.56 MHz HF frequency band specified in ISO / IEC 18092 or ISO / IEC 144443. Alternatively, it may be one that performs communication using other frequency bands, such as the 920 MHz UHF frequency band, the 125 kHz LF frequency band, or the 2.45 GHz microwave frequency band.

[0049] When IC card 1, which is a dual interface IC card, is held over an external device such as a reader / writer, an electromotive force or current is generated in the communication circuit by the magnetic field or radio waves generated by the reader / writer, and power is supplied to IC chip 74a. This enables IC chip 74a to be driven, enabling contactless transmission and reception of information with the reader / writer, and enabling information to be read from and rewritten to the memory.

[0050] The antenna wire 83 constituting the antenna 80 is typically formed of a coated conductor wire in which the periphery of a copper wire is coated with an insulating material. Other than this, 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. By using a coated conductor wire, the IC card 1 can be manufactured more inexpensively than, for example, copper foil etching methods. However, the IC card 1 of the present disclosure may also use an antenna wire formed by copper foil etching methods, metal foil punching methods, or the like.

[0051] The diameter of the antenna wire 83 is not particularly limited as long as it can ensure the characteristics as a contactless communication circuit, but it can be, for example, 0.03 mm or more and 0.30 mm or less, and preferably 0.05 mm or more and 0.15 mm or less. By setting the diameter in the latter range, durability against heat pressure during embedding and external forces due to cutting can be improved, and good communication characteristics can be ensured.

[0052] Next, a detailed description will be given of the configuration of the conductive plate 100, which is a conductive plate-like portion, namely the first conductive plate 110 and the second conductive plate 120. The first conductive plate 110 and the second conductive plate 120 are both formed of plate-like members that are substantially rectangular in plan view along the thickness direction of the IC card 1. As shown in FIGS. 2(a) and 2(b), the first conductive plate 110 and the second conductive plate 120 have an area that overlaps with the first recess 91 and an area that is located outside the first recess 91 in the plan view.

[0053] 2(a), in the plan view, of the outer periphery 93 of the recess 9, the straight lines overlapping the side 93a on the −X direction side along the Y axis and the side 93b on the +X direction side along the Y axis are designated as lines m1 and m2, respectively. Also, in the plan view, the straight line overlapping the side 93c on the −Y direction side along the X axis is designated as line m3.

[0054] In this case, the region of the first conductive plate 110 on the +X direction side of the line m1 and the region on the +Y direction side of the line m3 overlap with the first recess 91. However, since the first conductive plate 110 is buried at a position deeper than the bottom surface of the first recess 91, it is not exposed in the first recess. However, the first conductive plate 110 may be arranged so that it is exposed in the first recess 91.

[0055] Taking the first conductive plate 110 as an example, the width along the X-axis of the region of the first conductive plate 110 that overlaps with the first recess 91 in a plan view is W12, the same as the width of the first recess 91, and is narrower than the width W11 of the entire first conductive plate 110. Furthermore, the vertical width along the Y-axis of the region of the first conductive plate 110 that overlaps with the first recess 91 is W22, the same as the vertical width of the first recess 91, and is narrower than the vertical width W21 of the entire first conductive plate 110. While the sizes and ratios of W12, W11, W22, and W21 can be determined arbitrarily, by making W11 and W21 larger than W12 and W22, respectively, a satisfactory overlap area with the specific terminal of the external connection terminal 71 can be ensured even if the recess 9 is misaligned or the first conductive plate 110 is misaligned. The same is true for the second conductive plate 120.

[0056] The positions of the +X direction end of the first conductive plate 110 and the -X direction end of the second conductive plate 120 are the same as the positions of the +X direction and -X direction ends of the overlapping first recess 91. In other words, before the recess 9 is formed, the +X direction end of the first conductive plate 110 and the -X direction end of the second conductive plate 120 are arranged so as to extend into the second recess 92 in a plan view from the +Z direction.

[0057] As will be described later, the second recess 92 is a recessed region that is cut deeper than the surrounding first recess 91 and is used to house the IC chip body 74. When the recess 9 is formed, the protruding portion of the conductive plate 100 in the region of the second recess 92 is cut and removed. In other words, in the plan view, the first conductive plate 110 and the second conductive plate 120 after cutting the recess 9 are disposed in the region outside the second recess 92.

[0058] The first conductive plate 110 and the second conductive plate 120 are arranged and sized as described above. This ensures that the overlapping area with the C4 terminal and the C8 terminal, which are the external connection terminals 71 of the IC module 70, can be maximized even if the arrangement positions of the first conductive plate 110 and the second conductive plate 120 are misaligned along the X-axis direction. However, the +X-direction end of the first conductive plate 110 may be offset toward the −X-direction from the +X-direction end of the overlapping first recess 91. Furthermore, the −X-direction end of the second conductive plate 120 may be offset toward the +X-direction from the −X-direction end of the overlapping first recess 91. If the thickness of the IC chip body 74 is sufficiently thin, the second recess 92 may have the same depth as the first recess 91, and it is not necessary to provide the second recess 92 with a depth different from that of the first recess 91.

[0059] The first conductive plate 110 and the second conductive plate 120 may be made of aluminum, iron, nickel, copper, silver, palladium, platinum, or gold, or may be made of an alloy of multiple metals or multiple metal layers among these. They may also be made of a non-metallic material such as carbon.

[0060] The thickness of the first conductive plate 110 and the second conductive plate 120 is typically 0.05 mm or more and 0.3 mm or less. The size and shape of the first conductive plate 110 and the second conductive plate 120 when viewed in a plan view from the +Z direction are arbitrary. However, the overlapping area with the unused terminals, the C4 terminal and the C8 terminal, is preferably 50% or more of the area of ​​the C4 terminal and the C8 terminal, and more preferably 70% or more. That is, when the first conductive plate 110 overlaps with the C4 terminal, if the overlapping area is S1 and the area of ​​the C4 terminal is S2, S1 is preferably 0.5 times or more of S2, and more preferably 0.7 times or more.

[0061] If the above condition is 0.5 times or more, the amount of stored electricity in the capacitance component formed by the first conductive plate 110 and the C4 terminal increases, contributing to good contactless communication performance of the IC card 1. If the above condition is 0.7 times or more, this effect is further enhanced. Furthermore, even if the formation position of the second recess 92 or the arrangement position of the conductive plate 100 or the IC module 70 is slightly misaligned, by increasing the overlapping area between the conductive plate 100 and the C4 terminal and the C8 terminal, it is possible to suppress an extreme decrease in capacitance due to such misalignment.

[0062] 4, the capacitance CD2 formed by the first conductive plate 110 and the C4 terminal, the capacitance CD3 formed by the second conductive plate 120 and the C8 terminal, and the internal capacitance CD1 of the IC chip 74a are combined to form Ct. Furthermore, the inductance of the antenna 80 is L1. The resonant frequency f of the equivalent circuit can be calculated as f=1 / (2π×√(L1×Ct)). Therefore, it is necessary to maximize the overlap area S1 and adjust it to achieve the desired resonant frequency f.

[0063] As shown in FIG. 2(b), when the IC card 1 is viewed from above in the +Z direction, the first conductive plate 110 and the second conductive plate 120 have the following positional relationship with the external connection terminals 71 of the IC module 70. That is, the first conductive plate 110 at least partially overlaps the C4 terminal, which is electrically connected to the IC chip 74a and used for contactless communication. The first conductive plate 110 does not overlap the C1, C2, C3, C5, and C7 terminals, which are electrically connected to the IC chip 74a and used for contact communication. Similarly, the second conductive plate 120 at least partially overlaps the C8 terminal, which is electrically connected to the IC chip 74a and used for contactless communication. The second conductive plate 120 does not overlap the C1, C2, C3, C5, and C7 terminals, which are electrically connected to the IC chip 74a and used for contact communication.

[0064] However, the terminals of the external connection terminals 71 overlapped by the first conductive plate 110 and the second conductive plate 120 are not necessarily limited to the C4 terminal and the C8 terminal. The terminals of the external connection terminals 71 overlapped by the first conductive plate 110 and the second conductive plate 120 may be terminals used for non-contact communication. Therefore, the candidate terminals to be used for non-contact communication may be the C6 terminals instead of the C4 terminals or the C8 terminals, as they are terminals not used for contact communication. The external connection terminals 71 will be described in detail later.

[0065] (b) IC module Next, each of the main components of the IC module 70 will be described mainly with reference to Figure 3 and Figure 2(b). Note that Figure 3(b) shows the molded portion 74b of the IC chip body 74 only by outline so that the interior can be seen through.

[0066] The IC module 70 is embedded in a recess 9 formed in the card base 2. The substrate 72 of the IC module 70 is formed by bonding copper foil to the front and back of a flexible insulating resin film, such as glass epoxy resin or polyimide resin, with an adhesive. The copper foil on the front and back of the resin film is left to form a predetermined pattern. Specifically, to form external connection terminals 71 on one copper foil surface of the resin film, a photosensitive material is applied, a film plate with a predetermined pattern is placed, exposed, and the non-photosensitive portion is etched away, in this order. This results in a substrate 72 with a portion of the copper foil remaining in the predetermined pattern on the surface of the resin film. The substrate 72 is also provided with a plurality of bonding holes 76, which are through-holes for wire bonding to the external connection terminals 71.

[0067] This configuration differs from the IC module used in a dual-interface IC card that does not use a booster antenna, as shown in Patent Document 1. In the IC module 70p of the prior art, as shown in FIG. 3(c), the following steps are sequentially performed: applying a photosensitive material, placing a film plate with a predetermined pattern, exposing it to light, and etching away the non-photosensitive portions. Specifically, these steps are sequentially performed to form an external connection terminal 71 on one copper foil surface of a resin film that serves as a substrate 72, and antenna connection terminals 73a and 73b on the other copper foil surface. This results in a substrate 72 with a portion of the copper foil of the predetermined pattern remaining on both surfaces of the resin film. Unlike the IC module 70, the IC module 70p requires additional materials and processes because the antenna connection terminals 73a and 73b are formed on the surface of the substrate 72 opposite the external connection terminal 71.

[0068] As shown in Figures 3(a) and 2(b), the external connection terminal 71 has each section of the external terminal defined by the ISO / IEC 7816-2 standard. Each of these sections is connected to the pad 74p of the IC chip 74a by wires 75, such as gold wires, through the bonding holes 76 provided in the substrate 72, as shown in Figure 3(b). These bonding holes 76 and wires 75 are covered and protected by a molded portion 74b. Here, the bonding hole 76 corresponding to the C4 terminal will be referred to as bonding hole 76a, and the bonding hole 76 corresponding to the C8 terminal will be referred to as bonding hole 76b.

[0069] On the other hand, while not present in the IC module 70 of this embodiment, in the prior art IC module 70p, antenna connection terminals 73a and 73b are similarly connected to the IC chip 74a by wires 75, as shown in Figure 3(c). Furthermore, these connection points and wires 75 are covered and protected by a molded portion 74b. Instead, there are no bonding holes 76a and 76b as in this embodiment, and no wires 75 are connected between the C4 and C8 terminals and the pads 74p of the IC chip 74a.

[0070] As described above, the first conductive plate 110, the second conductive plate 120, and the C4 terminal and C8 terminal, which are sections of the external connection terminal 71, are arranged to face each other while being spaced a predetermined distance apart. The first conductive plate 110 and the second conductive plate 120, which are arranged facing each other, and the C4 terminal and C8 terminal of the external connection terminal 71, each form a capacitance component. As a result, the IC chip 74a and the antenna 80 included in the IC module 70 form a closed circuit incorporating these capacitance components in series. As a result, the IC card 1 forms a communication circuit for contactless communication using the IC chip 74a and the antenna 80.

[0071] Thus, IC module 70 used in a dual interface IC card capable of contact and contactless communication with an external device includes substrate 72 and IC chip 74a disposed on one side of substrate 72. IC module 70 further includes external connection terminal 71 disposed on the other side of substrate 72, electrically connected to IC chip 74a, and composed of a plurality of first terminals used for contact communication and a plurality of second terminals used for contactless communication. IC chip 74a and antenna 80 form a communication circuit for contactless communication.

[0072] Here, when viewed from the other side, assume that a plurality of capacitance-forming portions corresponding to the second terminals are arranged in an area that at least partially overlaps the second terminals but does not overlap the first terminals. Also assume that an antenna is arranged, electrically connecting the plurality of capacitance-forming portions to each other via an antenna wire. In this case, the plurality of second terminals and the plurality of capacitance-forming portions, i.e., conductive plates 100, are capacitively coupled to each other, thereby forming a closed circuit between IC chip 74a and antenna 80. The first terminal refers to any of terminals C1, C2, C3, C5, and C7, and the second terminal refers to any of terminals C4, C6, and C8.

[0073] The unused terminals C4, C8, and C6 of the external connection terminals 71 of the IC module 70 each have a section of at least 1.7 mm in height and 2.0 mm in width in accordance with the ISO / IEC 7816-2 standard. The thickness of the copper foil that makes up the external connection terminals 71 is usually 0.01 mm or more and 0.1 mm or less.

[0074] The layout of each terminal formed in the external connection terminal 71 defines each section of the external terminal as defined by the ISO / IEC 7816-2 and ISO / IEC 7816-3 standards. These standards define the following external terminals: C1 terminal (supply voltage input terminal), C2 terminal (reset signal input terminal), C3 terminal (clock signal input terminal), C5 terminal (signal ground terminal), and C7 terminal (serial data input or output terminal). Note that the C6 terminal is a standard or individual use terminal that is not normally used, and the C4 and C8 terminals are unused terminals reserved for future use.

[0075] The C1, C2, C3, C5, and C7 terminals may be abbreviated as VCC, RST, CLK, GND, and I / O, respectively. Therefore, in the external connection terminal 71 of the IC module 70 used in the IC card 1 of this embodiment, the C1, C2, C3, C5, and C7 terminals are connected to the IC chip 74a by wires 75, such as gold wires, through the above-mentioned bonding holes 76 provided in the substrate 72. This is shown in FIGS. 2(b) and 3(b). On the other hand, the C4, C6, and C8 terminals are unused for contact communication, but may be used as capacitive components for contactless communication in this disclosure. Therefore, some or all of these terminals are connected to the IC chip 74a by wires 75 through the bonding holes 76 provided in the substrate 72. In this embodiment, the C4 and C8 terminals are connected to pads 74p of the IC chip 74a by wires 75 through bonding holes 76a and 76b, respectively.

[0076] An IC chip body 74 is disposed on the surface of the substrate 72 opposite to the surface on which the external connection terminals 71 are formed. The IC chip body 74 is composed of an IC chip 74a adhered and fixed to the substrate 72 with an adhesive, bonding wires 75 for connection, and a molded portion 74b made of sealing resin for protecting these. The IC chip 74a includes a CPU for controlling both contact and contactless communication operations, and storage devices such as RAM, ROM, EEPROM, and flash memory. The IC chip 74a also includes various circuits, such as an interface circuit for decoding input signals and generating output signals for contact and contactless communication, and a power generation circuit. Note that these various circuits may be provided as elements separate from the IC chip 74a.

[0077] The molded portion 74b is provided as a protruding portion that covers the IC chip 74a and the wires 75 to protect them from external force loads and environmental loads. An ultraviolet curable resin, a thermosetting resin, or the like is used as the molded portion 74b.

[0078] (c) Adhesive layer After forming a recess 9 for embedding an IC module 70 in the card base 2 by cutting or the like using an end mill, the adhesive layer 11 is described below, which embeds and fixes the IC module 70 in the recess 9 and mechanically connects it to the recess 9. The adhesive layer 11 of this embodiment is a liquid or tape-like adhesive, and may be applied or affixed in advance to the surface of the substrate 72 of the IC module 70 opposite the external connection terminals 71, or may be applied or affixed to the bottom surface of the recess 9 of the card base 2 after cutting. Various types of adhesives can be used as the adhesive layer 11, such as thermosetting, thermoplastic, pressure-sensitive, ultraviolet-curing, and moisture-curing adhesives, but in this embodiment, a heat-reactive (thermoplastic or thermosetting) adhesive is used.

[0079] (d) Dual interface IC card manufacturing method Next, an example of a method for manufacturing the IC card 1, which is a dual interface IC card, using the card base 2, IC module 70, and adhesive layer 11 described above will be described.

[0080] First, the first conductive plate 110 and the second conductive plate 120 are adhered to one surface of the antenna support layer 6 facing the antenna support layer 5. Both may be adhered and fixed to the surface of the antenna support layer 6 using an adhesive. Next, a coated conductor covered with an insulating material is embedded as the antenna wire 83 on the surface of the antenna support layer 6 on which the conductive plate 100 is formed, using a winding machine, with one of the first conductive plate 110 and the second conductive plate 120 as the starting point and the other as the end point. Here, the winding machine welds the tip of the antenna wire 83 to the first conductive plate 110 and the second conductive plate 120 at the starting point and end point of the antenna wire 83.

[0081] Next, as shown in Figure 1(b), from the bottom in the thickness direction, over-sheet layer 8, core layer 7, antenna support layers 6 and 5, core layer 4, and over-sheet layer 3 are stacked in this order. After that, each large-sheet laminate with cards arranged vertically and horizontally in multiple faces is sandwiched between stainless steel plates from above and below in the thickness direction, and heat and pressure are applied to the laminate via the stainless steel plates. At this time, antenna 80 is formed so that it is sandwiched between antenna support layers 6 and 5.

[0082] By undergoing this heat pressing process, a large-sized sheet-unit card base can be obtained in which the layers of the laminate are integrated. Furthermore, if any of the oversheet layer, core layer, and antenna support layer has heat resistance such that they do not thermally fuse at a predetermined temperature, an adhesive sheet that thermally fuses at a predetermined temperature is sandwiched between the layers, or an adhesive is applied. These are then subjected to a heat pressing process to obtain an integrated large-sized sheet-unit card base. The large-sized sheet-unit card base, in which the cards obtained above are arranged in multiple rows and columns, is then punched out using a punching machine to form card base 2, which is the size of an ISO / IEC 7816 card.

[0083] Meanwhile, separately from the manufacturing of the card base 2 and the cutting process for forming the recess 9, the adhesive layer 11 is optionally attached to the IC module 70. The IC module 70 is typically a module tape in which the IC module 70 is continuously formed on a long tape in one or two rows. A certain amount of heat and pressure is applied to the surface of the module tape opposite the surface on which the external connection terminals 71 are formed of the substrate 72. The module tape with the adhesive layer 11 attached is then punched out with a punching machine into a roughly rectangular IC module 70 with rounded corners, thereby obtaining the IC module 70 with the adhesive layer 11 attached.

[0084] Thereafter, a recess 9 for embedding the IC module 70 is formed in the card base 2 by cutting using an end mill, thereby obtaining the cut card base 2. The recess 9 is composed of a first recess 91 of a first depth for accommodating the flat substrate 72 of the IC module 70, and a second recess 92 of a second depth deeper than the first recess 91 for accommodating the convex IC chip body 74.

[0085] An IC module 70 with an adhesive layer 11 attached is embedded in a card base 2 with a recess 9 formed therein, and a predetermined heat block is pressed against the external connection terminal 71, and a predetermined heat pressure is applied toward the card base 2 for a predetermined time.

[0086] This causes the adhesive layer 11 to melt, etc., thereby achieving a mechanical connection between the IC module 70 and the card base 2. The heating conditions for the external connection terminals 71 vary depending on the type and composition of the terminals, such as the time and heat pressure conditions, 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.

[0087] (e) Dual Interface IC Card of the First Embodiment To summarize the above, the IC card 1 of the first embodiment, which is a dual-interface IC card capable of contact communication and contactless communication with external devices, is as follows: The IC card 1 includes a card base 2 having a recess 9 formed therein, and an IC module 70 embedded in the recess 9.

[0088] The IC module 70 includes a substrate 72 and an IC chip 74a disposed on one side of the substrate 72. The IC module 70 further includes an external connection terminal 71 disposed on the other side of the substrate 72, electrically connected to the IC chip 74a, and configured with a plurality of first terminals used for contact communication and a plurality of second terminals used for contactless communication. The first terminals refer to any of the above-mentioned C1, C2, C3, C5, and C7 terminals, and the second terminals refer to any of the above-mentioned C4, C6, and C8 terminals.

[0089] The IC card 1 further includes an antenna 80 disposed inside the card base 2, the antenna 80 including an antenna wire 83 and a plurality of conductive plates 100 disposed at the ends of the antenna wire 83 and electrically connected to the antenna wire 83. The plurality of conductive plates 100 refers to a first conductive plate 110 and a second conductive plate 120. The plurality of second terminals and the plurality of conductive plates 100 are respectively capacitively coupled, so that the IC chip 74a and the antenna 80 form a closed circuit.

[0090] The external connection terminals 71 are exposed on the surface of the card base 2 on which the recesses 9 are formed. When viewed from above, the conductive plate 100 at least partially overlaps the second terminals but does not overlap the first terminals.

[0091] As a result, the IC chip 74a built into the IC module 70 and the antenna 80 built into the card base 2 form a closed circuit, enabling the IC card 1 to communicate contactlessly with external devices. In this way, the IC card 1 can achieve electrical connection between the IC module 70 and the antenna 80 without a physical connection, ensuring the durability of the IC card. Furthermore, since there is no need to provide any additional coils on the IC module 70 side or the card base side, the configuration of the IC module and card base can be simplified compared to conventional technologies using a booster antenna system.

[0092] 2. Second embodiment of the present disclosure Next, a second embodiment of the present disclosure will be described. In the following embodiments, components similar to those in the first embodiment will be assigned the same reference numerals, and detailed description thereof will be omitted. Fig. 5(a) is a plan view similar to Fig. 1(a) showing an IC card 1a according to the second embodiment of the present disclosure. Fig. 5(b) is a plan view corresponding to Fig. 2(b) that shows an enlarged view of the vicinity of the recess 9 of the IC card 1a in which the IC module 70a is embedded. The card base 2 of the IC card 1a according to this embodiment has a configuration similar to that of the card base 2 of the IC card 1 according to the first embodiment.

[0093] However, unlike the first embodiment, the tip of antenna wire 83 of antenna 80a, to which second conductive plate 120 is electrically connected, branches into a Y-shaped fork and is electrically connected to second conductive plate 120 and third conductive plate 121, respectively. These conductive plates are collectively referred to as conductive plate 100a. Also, as shown in FIG. 5(b), a bonding hole 76c is provided that corresponds to terminal C6, which is a section of external connection terminal 71 of IC module 70a that third conductive plate 121 at least partially overlaps. Wire 75 connects terminal C6 to pad 74p of IC chip 74a.

[0094] As shown in FIG. 5(b), when the IC card 1a is viewed from above in the +Z direction, the first conductive plate 110, the second conductive plate 120, and the third conductive plate 121 have the following positional relationship with the external connection terminals 71 of the IC module 70a: The first conductive plate 110 at least partially overlaps the C4 terminal, which is electrically connected to the IC chip 74a and used for contactless communication. The first conductive plate 110 does not overlap the C1, C2, C3, C5, and C7 terminals, which are electrically connected to the IC chip 74a and used for contact communication. Similarly, the second conductive plate 120 at least partially overlaps the C8 terminal, which is electrically connected to the IC chip 74a and used for contactless communication. The second conductive plate 120 does not overlap the C1, C2, C3, C5, and C7 terminals, which are electrically connected to the IC chip 74a and used for contact communication.

[0095] Furthermore, the third conductive plate 121 at least partially overlaps with the C6 terminal, which is electrically connected to the IC chip 74a and used for contactless communication, and does not overlap with the C1, C2, C3, C5, and C7 terminals, which are electrically connected to the IC chip 74a and used for contact communication.

[0096] As described in the first embodiment, the first conductive plate 110, the second conductive plate 120, the third conductive plate 121, and the C4 terminal, C8 terminal, and C6 terminal that are sections of the external connection terminal 71 are arranged to face each other while being spaced a predetermined distance apart. The first conductive plate 110, the second conductive plate 120, and the third conductive plate 121 that are arranged to face each other, and the C4 terminal, C8 terminal, and C6 terminal of the external connection terminal 71 each form a capacitance component. Here, the capacitance formed by the second conductive plate 120 and the C8 terminal and the capacitance formed by the third conductive plate 121 and the C6 terminal form a parallel circuit, and a circuit is formed in which these combined circuits and the capacitance formed by the first conductive plate 110 and the C4 terminal are combined in series.

[0097] As a result, the IC chip 74a and antenna 80 included in the IC module 70 form a closed circuit incorporating these capacitance components. As a result, the IC card 1 forms a communication circuit for contactless communication using the IC chip 74a and antenna 80.

[0098] Here, pad 74p of IC chip 74a, which is connected by wire 75 to bonding hole 76c corresponding to the C6 terminal, and pad 74p, which is connected by wire 75 to bonding hole 76b corresponding to the C8 terminal, may be electrically connected to each other in the internal circuit of IC chip 74a. That is, both pads 74p may be configured to be electrically shorted to each other internally. In this case, although second conductive plate 120 and third conductive plate 121 appear separate, in the circuit of IC card 1a, second conductive plate 120 and third conductive plate 121 are considered to be a single combined conductive plate, and can be considered to have a configuration similar to that of IC card 1 of the first embodiment.

[0099] Alternatively, instead of the above configuration, bonding holes 76b and 76c may be connected by separate wires 75, and pad 74p of IC chip 74a may be connected to only one of bonding holes 76b and 76c by wire 75. Even in this case, the second conductive plate 120 and third conductive plate 121 are considered to be combined into one conductive plate on the circuit of IC card 1a, and the configuration can be considered to be similar to that of IC card 1 of the first embodiment.

[0100] As described above, the IC card 1a, which is a dual interface IC card of this embodiment, has the following configuration. That is, in the IC card 1a, compared to the configuration of the IC card 1 of the first embodiment, the plurality of conductive plates 100a includes a first conductive plate 110 that is arranged at one end of the antenna line 83 and electrically connected to the antenna line 83. The plurality of conductive plates 100a also includes a second conductive plate 120 and a third conductive plate 121 that are arranged at the other branched ends of the antenna line 83 and electrically connected to the antenna line 83.

[0101] Here, when viewed in a plan view from the surface of the card base 2 on which the recess 9 is formed, the first conductive plate 110, the second conductive plate 120 and the third conductive plate 121 at least partially overlap with any one of the C4 terminal, the C8 terminal and the C6 terminal that are different from each other.

[0102] In this embodiment, the total overlap area of ​​the conductive plate 100a and the second terminals in a plan view of the IC card 1a can be made larger than that of the IC card 1 of the first embodiment. In the IC card 1, the second terminals that can overlap the conductive plate 100 are limited to two of the terminals C4, C6, and C8. However, in the IC card 1a of this embodiment, all of the terminals C4, C6, and C8 can be used as second terminals. This allows for a relatively large capacitance component formed by the conductive plate 100a and the second terminals. This allows for greater design freedom with regard to the thickness and area of ​​the copper foil of the external connection terminals 71, the thickness and size of each conductive plate 100a, and the layout in the planar and thickness directions of the card base 2.

[0103] In the present embodiment, the tip of the antenna wire 83 of the antenna 80a, to which the second conductive plate 120 is electrically connected, is bifurcated into a Y-shape and electrically connected to the second conductive plate 120 and the third conductive plate 121, respectively. It has also been described that the opposing first conductive plate 110, second conductive plate 120, and third conductive plate 121, and the C4 terminal, C8 terminal, and C6 terminal of the external connection terminal 71, respectively, form a capacitance component. However, this embodiment is not limited to this. The external terminal sections that form capacitance components with the first conductive plate 110, second conductive plate 120, and third conductive plate 121 may be the C8, C6, and C4 terminals, respectively. Alternatively, they may be the C6, C4, and C8 terminals, respectively, or other combinations may be used.

[0104] Furthermore, as will be described in detail in the third embodiment below, instead of the conductive plate 100 in the IC cards 1 and 1a of the first and second embodiments, both ends of the antenna wire 83 may be provided with a bellows wiring section having a repeated folded structure (so-called bellows shape or zigzag shape). Even in this case, the same effects as those described above can be obtained, because such a bellows wiring section functions as a pseudo conductive plate.

[0105] 3. Third embodiment of the present disclosure Next, a third embodiment of the present disclosure will be described. Fig. 6(a) is a plan view similar to Fig. 1(a) showing an IC card 1b according to the third embodiment of the present disclosure. Fig. 6(b) is a cross-sectional view corresponding to Fig. 1(b) of the IC card 1b of Fig. 6(a) taken along line BB along the X-axis near the bottom end of the IC module 70, as viewed from the -Y direction. Fig. 7(a) is a plan view corresponding to Fig. 2(a) showing an enlarged view of the recess 9 and its vicinity in the card base 2 with the IC module 70 removed, and Fig. 7(b) is a plan view corresponding to Fig. 2(b) showing an enlarged view of the recess 9 and its vicinity in the IC card 1b with the IC module 70 embedded.

[0106] The IC card 1b of this embodiment has a configuration basically similar to that of the IC card 1 of the first embodiment, but the configuration of the antenna 80b is different from that of the antenna 80 of the IC card 1. That is, the antenna wire 83 constituting the antenna 80b is disposed inside the card base 2, as shown by the dashed lines in FIGS. 7(a) and 7(b). The antenna wire 83 is wound one or more times around the periphery of the substantially rectangular card, and both ends thereof form a bellows wiring section 100b having a repeated folded structure. When the bellows wiring section 100b is matched to the conductive plate 100 of the IC card 1 of the first embodiment, the first bellows wiring section 130 is disposed at a position corresponding to the position of the first conductive plate 110, and the second bellows wiring section 140 is disposed at a position corresponding to the position of the second conductive plate 120.

[0107] 6(b), the bellows wiring portion 100b is embedded deeper than the bottom surface of the first recess 91. Therefore, when forming the first recess 91 by cutting or the like, there is a low risk of accidentally cutting off a part of the bellows wiring portion 100b and causing a break.

[0108] 7(b), when IC card 1b is viewed from above in the +Z direction, first bellows wiring portion 130 and second bellows wiring portion 140 have the following positional relationship with external connection terminal 71 of IC module 70. That is, first bellows wiring portion 130 at least partially overlaps with C4 terminal, which is electrically connected to IC chip 74a and used for contactless communication. Furthermore, first bellows wiring portion 130 does not overlap with C1, C2, C3, C5, and C7 terminals, which are electrically connected to IC chip 74a and used for contact communication. Similarly, second bellows wiring portion 140 at least partially overlaps with C8 terminal, which is electrically connected to IC chip 74a and used for contactless communication. Furthermore, second bellows wiring portion 140 does not overlap with C1, C2, C3, C5, and C7 terminals, which are electrically connected to IC chip 74a and used for contact communication.

[0109] In this embodiment, first bellows wiring portion 130 of bellows wiring portion 100b overlaps with a portion of the C4 terminal of the section of external connection terminal 71 of IC module 70. Also, second bellows wiring portion 140 of bellows wiring portion 100b overlaps with a portion of the C8 terminal of the section of external connection terminal 71 of IC module 70. In other words, the C4 terminal of external connection terminal 71 and first bellows wiring portion 130 form a capacitance component shown as capacitance CD2 in the equivalent circuit diagram of FIG. 4. Also, the C8 terminal of external connection terminal 71 and second bellows wiring portion 140 form a capacitance component shown as capacitance CD3.

[0110] As a result, the IC chip 74a built into the IC module 70 and the antenna 80b built into the card base 2 form a closed circuit as shown in Fig. 4. The contents of the equivalent circuit diagram of Fig. 4 explained in the first embodiment can also be applied to the IC card 1b of this embodiment. In other words, if each element is set so that the inductance, capacitance, and resistance have appropriate values, the IC card 1b can communicate contactlessly with external devices.

[0111] Furthermore, bellows wiring section 100b is positioned so as not to overlap with terminals C1, C2, C3, C5, and C7 used in contact communication. This prevents a parasitic capacitance from accidentally occurring between bellows wiring section 100b and the terminals used in contact communication while IC card 1b is performing contactless communication, which can result in unexpected power consumption for contact communication and malfunction of contactless communication.

[0112] Note that the ratio of the area of ​​the bellows wiring portion 100b to the area of ​​the region overlapping with the second terminal when the bellows wiring portion 100b is viewed in a plan view along the Z-axis direction is preferably 30% or more, and more preferably 50% or more. The former condition allows the bellows wiring portion 100b to form a good capacitance component in combination with the C4, C8, and other terminals. The latter condition allows the bellows wiring portion 100b to form a sufficient capacitance component in combination with the C4, C8, and other terminals, improving design freedom with regard to the thickness and compartment area of ​​the copper foil of the external connection terminals 71, the line width, arrangement pitch, and number of arrangements of the bellows wiring portion 100b, and the arrangement in the planar and thickness directions of the card base 2.

[0113] In this embodiment, the ratio of the area of ​​the bellows wiring portion 100b to the area of ​​the region overlapping with the second terminal may be, for example, the ratio of the area of ​​the first bellows wiring portion 130 to the area of ​​the region overlapping with the C4 terminal. Alternatively, it may be the ratio of the area of ​​the second bellows wiring portion 140 to the area of ​​the region overlapping with the C8 terminal. Furthermore, both of these conditions may be satisfied.

[0114] Furthermore, the concept of this embodiment may be applied to the second embodiment, and the tips of antenna wire 83 may be configured as a first bellows wiring portion, a second bellows wiring portion, and a third bellows wiring portion, instead of first conductive plate 110, second conductive plate 120, and third conductive plate 121 in the second embodiment. Even in this case, the same effects as in the second embodiment can be obtained. [Explanation of symbols]

[0115] 1, 1a, 1b IC card 2 Card Base 3, 8 oversheet layers 4, 7 Core layer 5, 6 Antenna support layer 9 Recess 11 Adhesive layer 14 Antenna sheet 70, 70a, 70p IC modules 71 External connection terminal 72 PCB 74 IC chip body 74a IC chip 74b molded part 74p Pad 75 wire 76, 76a, 76b, 76c Bonding holes 80, 80a, 80b antennas 83 Antenna Wire 91 First recess 92 Second recess 93 Outer circumference Areas 93a, 93b, and 93c 100, 100a conductive plate 100b Bellows wiring section 110 First conductive plate 120 Second conductive plate 121 Third conductive plate 130 First bellows wiring section 140 Second bellows wiring section

Claims

1. A dual interface IC card capable of contact communication and contactless communication with an external device, a card base having a recess formed therein; an IC module embedded in the recess; an antenna disposed inside the card base, the IC module includes a substrate, an IC chip disposed on one surface of the substrate, and an external connection terminal disposed on the other surface of the substrate, electrically connected to the IC chip, and including a plurality of first terminals used for the contact communication and a plurality of second terminals used for the contactless communication; the antenna includes an antenna wire and a plurality of capacitance forming portions disposed at a tip of the antenna wire and electrically connected to the antenna wire; the plurality of second terminals and the plurality of capacitance forming portions are respectively capacitively coupled, so that the IC chip and the antenna form a closed circuit; the external connection terminals are exposed on the surface of the card base where the recesses are formed, When viewed from above, the capacitance forming portion at least partially overlaps the second terminal and does not overlap the first terminal.

2. 2. The dual interface IC card according to claim 1, wherein the second terminal is any one of a C4 terminal, a C8 terminal, and a C6 terminal specified in ISO / IEC 7816-2.

3. 2. The dual interface IC card according to claim 1, wherein said capacitance forming portion is a conductive plate.

4. 2. The dual interface IC card according to claim 1, wherein said capacitance forming portion is a bellows wiring portion in which the tip of said antenna wire has a repeated folded structure.

5. the conductive plate is composed of a first conductive plate that is arranged at one end of the antenna line and is electrically connected to the antenna line, and a second conductive plate and a third conductive plate that are arranged at the other branched end of the antenna line and are electrically connected to the antenna line, 4. The dual interface IC card of claim 3, wherein when viewed in a plane from the surface, the first conductive plate, the second conductive plate, and the third conductive plate at least partially overlap with one of the second terminals, which are different from each other, selected from a C4 terminal, a C8 terminal, and a C6 terminal defined in ISO / IEC 7816-2.

6. An IC module used in a dual interface IC card capable of contact communication and contactless communication with an external device, the IC module includes a substrate, an IC chip disposed on one surface of the substrate, and an external connection terminal disposed on the other surface of the substrate, electrically connected to the IC chip, and including a plurality of first terminals used for the contact communication and a plurality of second terminals used for the contactless communication; an IC module in which, when viewed in a plane from the other surface, a plurality of capacitance forming portions corresponding to the second terminals are arranged in an area that at least partially overlaps with the second terminals but does not overlap with the first terminals, and when an antenna is arranged in which the plurality of capacitance forming portions are electrically connected to each other by an antenna wire, the plurality of second terminals and the plurality of capacitance forming portions are capacitively coupled, respectively, thereby causing the IC chip and the antenna to form a closed circuit.

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