Dual interface IC card and IC module

Abstract

To provide a dual interface IC card with which a reduction in reliability of contactless communication can be suppressed, and an IC module used for the same.SOLUTION: An IC card 1 comprises: a card base body 2 provided with a recess 9; an IC module 70 buried in the recess 9; and an antenna 80 arranged in the card base body 2 and provided with a conductive plate 100 which is a capacitance-forming unit electrically connected to an antenna line 83. The IC module 70 includes: a substrate 72; and an external connection terminal 71 composed of an IC chip 74a and an electrically connected terminal 73a for antenna connection, a first terminal electrically connected with an IC chip 74, and an electrically unconnected second terminal. The terminal 73a for antenna connection and the capacitance forming unit are electrically connected to 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. A capacitance forming unit 100 is superimposed with the second terminal and not superimposed with the first terminal in a plan view.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] A typical conventional dual interface IC card is as follows: Patent Document 1 describes a contact and non-contact type IC card having an external device connection terminal and an antenna coil and antenna coil connection terminal embedded inside the card base. In this contact and non-contact type 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 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 connected and bonded to the contact surface of the IC module using a conductive adhesive material.

[0004] Here, the shape of the antenna coil connection terminal in the IC module mounting recess is preferably a rectangle with its long sides parallel to the short sides of the card, and the total area of ​​the antenna coil connection terminal in the IC module mounting recess is 3 mm 2 It also states that this is because the IC card is susceptible to bending stress in the long side direction, whereas if the connection is made parallel to the short side, the connection will be subjected to less stress and will be more likely to be prevented from breaking.

[0005] Incidentally, the conductive plate formed at the tip of such an antenna (antenna coil connection terminal in Patent Document 1) is usually overlapped with an external connection terminal (external device connection terminal in Patent Document 1) when the IC card is viewed in plan, as shown in Figure 1 of Patent Document 1. The external connection terminal is a multi-section terminal for supplying power and exchanging signals and data when the IC card makes contact and communicates with an external device, and the layout and function of each terminal are specified in the ISO / IEC 7816-2:2007 standard.

[0006] A plan view of an IC card 1p, a more common dual-interface IC card, is shown in Figure 5(a). Figures 6(a) and 6(b) show the IC module 70p used in the IC card 1p, viewed from the front and rear sides of the card, respectively. An antenna 80p embedded in the card base 2p has conductive plates 100p at both ends. These conductive plates 100p are arranged along the long side of the IC card so as to overlap the external connection terminal 71 and antenna connection terminals 73a and 73b of the IC module 70p. The four terminals located vertically to the left of the external connection terminal 71 are designated C1, C2, C3, and C4 as specified in the above standard. The functions of each terminal are specified as follows: C1 is a supply voltage input terminal, C2 is a reset signal input terminal, C3 is a clock signal input terminal, and C4 is an unused terminal.

[0007] Here, from the viewpoint of stress relaxation of the connection portion described in Patent Document 1, it is preferable that each conductive plate is rectangular along the short side direction of the IC card and has a certain size or more, and therefore it is considered that the conductive plates are often arranged so as to overlap with multiple terminals in a plan view of the IC card. However, when the conductive plates are arranged so as to overlap with terminals that perform contact communication between the IC card and external devices, such as supply voltage input terminals and clock signal input terminals, contactless communication may be hindered.

[0008] That is, although the detailed mechanism is not limited to this, for example, as shown in the equivalent circuit diagram of FIG. 5(b), specific terminals of the external connection terminal 71 overlapping each conductive plate and the two conductive plates form parasitic capacitances CD2 and CD3, respectively. These specific terminals are connected to the IC chip 74a via terminals T1 and T2. Therefore, when the IC card 1p is used for contactless communication, a closed circuit is formed that includes not only the inductance L1 due to the antenna 80p, the capacitance CD1 and resistance R1 due to the IC chip 74a, but also the parasitic capacitances CD2 and CD3. As a result, current may flow through specific terminals, such as the reset signal input terminal, during contactless communication, potentially causing the IC chip 74a to malfunction. Furthermore, such power consumption by the IC chip 74a may reduce the current available for contactless communication, potentially impeding contactless communication. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-182017 Summary of the Invention [Problem to be solved by the invention]

[0010] The present disclosure has been made in view of the above circumstances, and aims to provide a dual interface IC card that can suppress a decrease in the reliability of contactless communication, and an IC module used therefor. [Means for solving the problem]

[0011] A first configuration of a dual interface IC card according to this embodiment, which is capable of contact communication and contactless communication with an external device, comprises a card base having a recess, an IC module embedded in the recess, and an antenna disposed inside the card base, wherein the IC module comprises a substrate, an IC chip disposed on one side of the substrate and a plurality of antenna connection terminals electrically connected to the IC chip, and an external connection terminal disposed on the other side of the substrate and consisting of a plurality of first terminals electrically connected to the IC chip and a plurality of second terminals not electrically connected to the IC chip, wherein the antenna comprises an antenna wire and a plurality of capacitance forming portions disposed at the ends of the antenna wire and electrically connected to the antenna wire, wherein the plurality of antenna connection terminals and the plurality of capacitance forming portions are electrically connected to each other by a conductive adhesive, 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.

[0012] 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.

[0013] In addition, a third configuration of a dual interface IC card according to another embodiment of the present invention is the first or second configuration, wherein the conductive adhesive is an anisotropic conductive film.

[0014] In addition, a fourth configuration of a dual interface IC card according to another embodiment of the present invention is such that in any one of the first to third configurations, the capacitance forming portion may be a conductive plate.

[0015] In addition, a fifth configuration of a dual interface IC card according to another embodiment of the present invention is any one of the first to third configurations, in which the capacitance forming portion is a bellows wiring portion in which the tip of the antenna wire has a repeated folded structure.

[0016] In addition, a sixth configuration of a dual interface IC card according to another form of this embodiment may be any of the first to fifth configurations, in which a conductive lead wire is arranged on one surface of the substrate, one end of the lead wire is provided with the antenna connection terminal, and the other end is electrically connected to a metal bump or an end of a metal wire that is electrically connected to an electrode of the IC chip, and when viewed in a plane from the surface, the lead wire may overlap the first terminal and the second terminal.

[0017] In a seventh configuration of an IC module used in a dual interface IC card capable of contact 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 a plurality of antenna connection terminals electrically connected to the IC chip, and an external connection terminal arranged on the other side of the substrate and consisting of a plurality of first terminals electrically connected to the IC chip and a plurality of second terminals not electrically connected to the IC chip, and when viewed in a plane from the other side, the antenna connection terminals at least partially overlap with the second terminals but do not overlap with the first terminals.

[0018] In addition, an eighth configuration of an IC module according to another embodiment of the present invention is the seventh configuration, wherein a conductive lead wire is arranged on one side of the substrate, one end of the lead wire is provided with the antenna connection terminal, and the other end is electrically connected to a metal bump or an end of a metal wire that is electrically connected to an electrode of the IC chip, and when viewed in a plane from the other side, the lead wire may at least partially overlap with the first terminal. [Effects of the Invention]

[0019] According to this embodiment, it is possible to provide a dual interface IC card that can suppress a decrease in reliability of contactless communication, and an IC module used therefor. [Brief explanation of the drawings]

[0020] [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(b) and 2(a) are cross-sectional and plan views illustrating the structure of a dual-interface IC card according to a second embodiment of the present invention. [Figure 5] 1A and 1B are a plan view and an equivalent circuit diagram illustrating the structure of a dual-interface IC card according to the prior art. [Figure 6] FIG. 4 is a diagram corresponding to FIG. 3 and illustrating the configuration of an IC module according to the prior art. [Figure 7] 1(a) and 1(b) are plan and cross-sectional views illustrating the structure of a dual-interface IC card according to a third embodiment. [Figure 8] 10 is a plan view of the vicinity of the recess corresponding to FIG. 2(a) for explaining the arrangement of the bellows wiring section of the dual interface IC card according to the third embodiment. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0021] 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.

[0022] 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.

[0023] 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.

[0024] 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.

[0025] 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.

[0026] 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 view corresponding to Fig. 3(b) showing variations of the IC module.

[0027] 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.

[0028] 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, the antenna wire 83 constituting the antenna 80 and a first conductive plate 110 as a conductive plate 100 at its end are sandwiched between the two. As shown in FIG. 1(a), the conductive plate 100 is arranged as the first conductive plate 110 and the second conductive plate 120 near the bottom end of the recess 9 along the X-axis direction in a plan view from the +Z direction.

[0029] The conductive plate 100 is one form of the capacitance-forming portion in the present disclosure. As described below, the capacitance-forming portion functions as a predetermined capacitance element in conjunction with terminals not electrically connected to the IC chip, such as the C4 and C8 terminals, among the sections of the external connection terminals 71 of the IC module 70. A capacitance-forming portion having such a function is not limited to a conductive plate. For example, the capacitance-forming portion may be a so-called bellows-shaped portion in which the antenna wire 83 is repeatedly folded back along the Y-axis direction and continuously aligned in the X-axis direction. This is referred to as a bellows-shaped wiring portion. In other words, the capacitance-forming portion may be either a conductive plate or a bellows-shaped wiring portion. In the latter case, the bellows-shaped antenna wire functions as a pseudo-capacitive element similar to a conductive plate. In the present disclosure, the first and second embodiments mainly exemplify a capacitance-forming portion that is a conductive plate, while the third embodiment mainly exemplifies a capacitance-forming portion that is a bellows-shaped wiring portion.

[0030] 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.

[0031] As will be described later, antenna connection terminals 73a and 73b, which are electrically connected to the IC chip contained therein, are provided on the surface of the substrate 72 of the IC module 70 facing the card base 2. As shown in Fig. 1(b) , the antenna connection terminal 73a of the IC module 70 is electrically connected to the conductive plate 100 via a conductive adhesive such as conductive paste 12. As a result, the plurality of antenna connection terminals 73a, 73b are electrically connected to the plurality of conductive plates 100, i.e., the first conductive plate 110 and the second conductive plate 120, respectively, via the conductive adhesive, and the IC chip 74a and the antenna 80 form a closed circuit.

[0032] At this time, the external connection terminals 71 are exposed on the surface of the card base 2 on which the recesses 9 are formed. Also, 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 with 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 with terminals used for contact communication according to the standard, such as the C1 terminal, C2 terminal, C3 terminal, C5 terminal, and C7 terminal.

[0033] As described above, 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 suppresses the generation of parasitic capacitance between the conductive plate 100 and the external connection terminals 71, as occurs in the IC card 1p of the prior art. In a plan view from the +Z direction, the conductive plate 100 and the external connection terminals 71 overlap only unused terminals of the external connection terminals 71 that are not electrically connected to the IC chip 74a. This is because such unused terminals are isolated from the circuit, making it difficult for electric charge to accumulate and for AC current to flow.

[0034] By overlapping the conductive plate 100 with unused terminals of the external connection terminal 71, the conductive plate 100 can be safely placed in an area that overlaps with the external connection terminal 71 in plan view without worrying about a decrease in communication characteristics. This makes it possible to minimize the distance between the antenna connection terminals 73a, 73b of the IC module 70 and the conductive plate 100, improving the reliability of the electrical connection therebetween.

[0035] As described above, the IC card 1 of this embodiment can prevent current from unintentionally flowing between the external connection terminal 71 and the IC chip 74a during contactless communication, and can prevent a decrease in the reliability of contactless communication.

[0036] 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.

[0037] (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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] (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.

[0043] (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.

[0044] (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.

[0045] 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 layers themselves are not adhesive when heated, they can be integrated by additionally forming a layer of a known adhesive that generates adhesive force when heated between the core layer and the over-sheet layer. 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.

[0046] (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 the 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 adhered and fixed to the surface of the antenna support layer 6 facing the antenna support layer 5 before lamination 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 placed. The first conductive plate 110 and the second conductive plate 120 are aligned in the left-right direction at the intended position for mounting the IC module 70 so that portions of them overlap the antenna connection terminals 73a and 73b of the IC module 70 when placed.

[0047] 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.

[0048] 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.

[0049] (v) Antenna In the antenna 80 formed on the antenna support layer 6, the antenna connection terminals 73a and 73b of the IC module 70 are electrically connected to a pair of conductive plates 100, to which the multiple tips of the antenna wire 83 are electrically connected, via a conductive adhesive such as conductive paste 12. The pair of conductive plates 100 is a first conductive plate 110 and a second conductive plate 120. As a result, the IC chip 74a and the antenna 80 provided in the IC module 70 form a communication circuit for contactless communication. 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] At this time, the first conductive plate 110 has an area on the +X side of the line m1 and an area on the +Y side of the line m3 that overlaps with the first recess 91, and is exposed from the card base 2 at a third recess 94 that is formed deeper than the first recess 91 within the area of ​​the first recess 91. Similarly, the second conductive plate 120 has an area on the -X side of the line m2 and an area on the +Y side of the line m3 that overlaps with the first recess 91, and is exposed from the card base 2 at a third recess 94 that is formed deeper than the first recess 91 within the area of ​​the first recess 91.

[0056] It is preferable that the area of ​​the third recess 94 encompasses the areas of the antenna connecting terminals 73a and 73b when the IC module 70 is placed in the plan view, because this ensures stable contact areas for the electrical connection between the antenna connecting terminal 73a and the first conductive plate 110 and the electrical connection between the antenna connecting terminal 73b and the second conductive plate 120.

[0057] Meanwhile, 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. That is, 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.

[0058] 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.

[0059] By arranging and sizing the first conductive plate 110 and the second conductive plate 120 in this manner, the contact area with the antenna connection terminals 73a, 73b of the IC module 70 can be reliably secured even if 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. Also, 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.

[0060] The first conductive plate 110 and the second conductive plate 120 may have a laminated structure including at least two layers: a first conductive member and a second conductive member laminated on the +Z direction side of the first conductive member. In this case, the second conductive member is a member that is less susceptible to oxidation than the first conductive member. A member that is less susceptible to oxidation can be rephrased as a metal that has a lower ionization tendency than the first conductive member, for example, when both the first conductive member and the second conductive member are metals. Examples of such metals include aluminum, iron, nickel, or copper for the first conductive member, and silver, palladium, platinum, or gold for the second conductive member.

[0061] Furthermore, the first conductive member and the second conductive member are not limited to members made of a single metal, but may be alloys or non-metallic members such as carbon. In such cases, the relative resistance to oxidation of the first conductive member and the second conductive member may be evaluated by calculation or experimentation based on the compounding ratio of the metals in each member.

[0062] Furthermore, the first conductive plate 110 and the second conductive plate 120 may have a laminated structure of three or more layers, including a layer of a different conductive material other than the first conductive material and the second conductive material. For example, the first conductive material, the third conductive material, and the second conductive material may be laminated in this order from the -Z direction to the +Z direction. In this case, it is preferable that the second conductive material is a material that is less susceptible to oxidation than either the first conductive material or the third conductive material. As a suitable example of such a structure, for example, the first conductive material may be copper, the third conductive material may be nickel-plated, and the second conductive material may be gold-plated.

[0063] Considering the ease of material procurement, cost, processability, electrical properties, etc., it is preferable to use copper, which has high conductivity, as the first conductive member and silver plating as the second conductive member among the above listed materials. By using copper, which can ensure sufficient conductivity, as the first conductive member and silver plating, which is resistant to oxidation and easily exposes the metal interface when the resin layer is cut with an end mill, as the second conductive member, it is possible to obtain good electrical properties and processability while suppressing increases in cost.

[0064] 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 in a plan view from the +Z direction are arbitrary, but the overlapping area with the unused terminals, the C4 terminal and the C8 terminal, is preferably 50% or more, and more preferably 70% or more, of the area of ​​the C4 terminal and the C8 terminal. 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, and more preferably 0.7 times or more, of S2.

[0065] If the above condition is 0.5 times or more, the first conductive plate 110 can be arranged in a region as close as possible to the IC chip 74a. This makes it easier to electrically connect the antenna connection terminal 73a and the first conductive plate 110 with the conductive paste 12 after the third recess 94 is formed, improving connection reliability. This is because even if the formation position of the third recess 94 or the arrangement position of the antenna connection terminal 73a is shifted, the first conductive plate 110 is arranged over a wide range, so this positional shift can be absorbed. If the above condition is 0.7 times or more, this effect is further enhanced.

[0066] As shown in FIG. 2(b), when the IC card 1 is viewed from above in the +Z direction, the first conductive plate 110 has 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 a terminal not electrically connected to the IC chip 74a. 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. Similarly, the second conductive plate 120 at least partially overlaps the C8 terminal, which is a terminal not electrically connected to the IC chip 74a. 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.

[0067] 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. Since the terminals of the external connection terminals 71 overlapped by the first conductive plate 110 and the second conductive plate 120 may be unused terminals, they may be C6 terminals instead of C4 terminals or C8 terminals. Details of the external connection terminals 71 will be described later.

[0068] (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). In Figure 3(b), the molded portion 74b of the IC chip body 74 is shown only by outline so that the interior can be seen through.

[0069] The IC module 70 is embedded in a recess 9 formed in the card base 2. Antenna connection terminals 73a and 73b of the substrate 72 of the IC module 70 are electrically connected to the first conductive plate 110 and the second conductive plate 120, which are the conductive plate 100 of the antenna 80, respectively. This allows the IC card 1 to form a communication circuit for contactless communication. Furthermore, the IC card 1 can perform contact communication with a contact-type reader / writer or the like through the external connection terminal 71 provided on the IC module 70.

[0070] Substrate 72 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, and leaving the copper foil on the front and back of the resin film so as to form a predetermined pattern. Specifically, a photosensitive material is applied, a film plate with a predetermined pattern is placed, exposed, and the non-photosensitive portion is etched away to form external connection terminals 71 on one copper foil surface of the resin film and antenna connection terminals 73a and 73b on the other copper foil surface. This sequential process forms substrate 72, with copper foil remaining in the predetermined pattern on the front and back of the resin film. Substrate 72 also has a plurality of bonding holes 76, which are through-holes for wire bonding to external connection terminals 71, pre-formed in the substrate.

[0071] 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 pads 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). Similarly, the antenna connection 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 portion 74b.

[0072] The antenna connection terminals 73a and 73b are formed outside the contour of the molded portion 74b. Therefore, approximately linear lead wires 73c and 73d are provided as conductive regions from the bonding region of one end of a wire 75, the other end of which is connected to a pad 74p of the IC chip 74a, to the antenna connection terminals 73a and 73b, respectively. As shown in FIG. 3(b), the IC module 70 is provided with an approximately linear lead wire 73c extending from the antenna connection terminal 73a along the X-axis direction. Furthermore, an approximately linear lead wire 73d extending from the antenna connection terminal 73b along the X-axis direction is also provided.

[0073] An antenna connection terminal 73a is provided at one end of lead wire 73c on the -X direction side, and a wire 75 is connected from pad 74p of IC chip 74a to one end of lead wire 73c on the +X direction side as a bonding region, and a wire 75 is connected from pad 74p, which is an electrode of IC chip 74a, to one end of lead wire 73d on the +X direction side as a bonding region, and a wire 75 is connected from pad 74p, which is an electrode of IC chip 74a, to one end of lead wire 73c on the +X direction side as a bonding region, and a metal bump is also usable as the electrical connection between the other end of lead wire 73c or 73d and pad 74p of IC chip 74a, however, is not limited to a metal wire.

[0074] In the IC module 70 shown in Figure 3(b), when viewed from above along the Z axis, the other ends of the lead wires 73c and 73d connected to the pads 74p overlap C5, and the opposite ends overlap C4 and C8. This is because the layout of the external connection terminals 71 defines the C5 terminal over a wide area that includes the mounting area of ​​the IC chip 74a of the external connection terminals 71. Meanwhile, as a modified IC module, an IC module 70a as shown in Figure 3(c) can also be used. Figure 3(c) is a view of the IC module 70a viewed from the -Z direction, and corresponds to Figure 3(b).

[0075] Here, the lead wires 73e and 73f have a different shape and arrangement from the lead wires 73c and 73d of the IC module 70. That is, as shown in Fig. 3(c), the lead wires 73e and 73f are generally L-shaped lead wires in which a substantially linear portion extending from the antenna connecting terminal 73a along the Y-axis direction is connected to a substantially linear portion extending along the X-axis direction toward the bonding area for connecting to the pad 74p. Also, the lead wires 73e and 73f are generally L-shaped lead wires in which a substantially linear portion extending from the antenna connecting terminal 73b along the Y-axis direction is connected to a substantially linear portion extending along the X-axis direction toward the bonding area for connecting to the pad 74p.

[0076] Specifically, antenna connection terminal 73a is provided at one end of lead wire 73e on the -Y direction side, and when it extends in the +Y direction, it bends in the +X direction and extends further to the other end, which serves as a bonding region where wire 75 is connected from pad 74p of IC chip 74a. Also, antenna connection terminal 73b is provided at one end of lead wire 73f on the -Y direction side, and when it extends in the +Y direction, it bends in the -X direction and extends further to the other end, which serves as a bonding region where wire 75 is connected from pad 74p of IC chip 74a.

[0077] Thus, an IC module 70 used in a dual-interface IC card capable of contact and contactless communication with an external device includes a substrate 72, an IC chip 74a disposed on one side of the substrate 72, and multiple antenna connection terminals 73a and 73b electrically connected to the IC chip 74a. The IC module 70 also includes an external connection terminal 71 disposed on the other side of the substrate, the external connection terminal 71 consisting of multiple first terminals electrically connected to the IC chip 74a and multiple second terminals not electrically connected to the IC chip 74a. When viewed from the other side, the antenna connection terminals 73a and 73b at least partially overlap the second terminals but not the first terminals. The first terminal refers to any of the C1, C2, C3, C5, and C7 terminals, and the second terminal refers to any of the C4, C6, and C8 terminals.

[0078] In the IC module 70a shown in FIG. 3(c), as viewed in a plan view along the Z axis, lead wire 73e overlaps with C2, C3, and C4 as it moves from the other end of lead wire 73e connected to pad 74p to the other end on the opposite side. Similarly, lead wire 73f overlaps with C6, C7, and C8 as it moves from the other end of lead wire 73f connected to pad 74p to the other end on the opposite side. Thus, in both IC modules 70 and 70a, the lead wire overlaps with both terminals electrically connected to the IC chip 74a and terminals not electrically connected to the IC chip 74a. However, because the overlapping area between the terminals electrically connected to the IC chip 74a and each lead wire is very small, the effect of parasitic capacitance generated in this area is virtually negligible.

[0079] In IC module 70a, conductive lead wires 73e and 73f are arranged on one surface of substrate 72, and antenna connection terminals 73a and 73b are provided at one ends of lead wires 73e and 73f. The other ends of lead wires 73e and 73f are electrically connected to ends of metal bumps or metal wires that are electrically connected to electrodes of IC chip 74a, and when viewed from above from the other surface, lead wires 73e and 73f at least partially overlap with first terminals.

[0080] To suppress the effects of parasitic capacitance, the lead wire width is preferably 500 μm or less and the lead wire length is preferably 2.5 mm or less. Furthermore, 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 vertically and 2.0 mm horizontally, as required by the ISO / IEC 7816-2 standard. Furthermore, the thickness of the copper foil that makes up the external connection terminals 71 is typically 0.01 mm or more and 0.1 mm or less. In relation to this and the thickness of the conductive plate 100 described above, it is believed that if the lead wire width and length are within the above ranges, the effect of parasitic capacitance due to the lead wire will be almost nonexistent.

[0081] 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.

[0082] 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 as shown in FIGS. 2(b) and 3(b). On the other hand, the C4, C6, and C8 terminals are not connected to the IC chip 74a by wires 75.

[0083] 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.

[0084] 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 for the molded portion 74b.

[0085] (c) Conductive adhesive A recess 9 for embedding the IC module 70 is formed in the card base 2 by cutting using an end mill or the like, and then the IC module 70 is embedded and fixed in the recess 9 for electrical connection. The conductive adhesive used in this embodiment is a liquid conductive paste 12. As shown in FIG. 1(b), the conductive paste 12 is a liquid material that is sandwiched between the first conductive plate 110 and the antenna connection terminal 73a formed on the substrate 72 of the IC module 70. An adhesive layer 11 for mechanically connecting the IC module 70 to the card base 2 is provided between the antenna support layer 5 and the substrate 72 of the IC module 70, where the conductive paste 12 is not provided.

[0086] The adhesive layer 11 is a liquid or tape-like adhesive, and may be applied and stuck in advance to the surface of the substrate 72 of the IC module 70 opposite the external connection terminal 71, or may be applied and stuck on the bottom surface of the recess 9 of the card base 2 after cutting.

[0087] A typical conductive paste 12 is applied and filled into a third recess 94, which is deeper than the first recess 91 and is located in a different position from the second recess 92 among the recesses 9 provided in the card base 2. The first and second conductive plates 120 of the antenna 80, which have been embedded in the card base 2 beforehand, are partially exposed on the bottom surface of the third recess 94. In this case, the conductive paste 12 is, for example, a so-called silver paste in which silver particles are dispersed as a filler in an epoxy resin. In addition to the silver paste, the conductive paste 12 may also be a solder paste.

[0088] Conductive paste 12, which is a liquid adhesive, is applied and filled into third recess 94 of card base 2, and IC module 70 is placed on top of it and pressed down by applying heat and pressure. As a result, antenna connection terminals 73a and 73b of IC module 70 are electrically connected to first conductive plate 110 and second conductive plate 120 of antenna 80, respectively, via conductive paste 12. As a result, IC chip 74a and antenna 80 built into IC module 70 are electrically connected, forming a communication circuit that enables contactless communication.

[0089] Furthermore, in a plan view of the IC card 1 from the +Z direction, the conductive plate 100 is positioned so as to at least partially overlap the C4 terminal and the C8 terminal that are not electrically connected to the IC chip 74a. The conductive plate 100 is also positioned so as not to overlap the C1, C2, C3, C5, or C7 terminal that are electrically connected to the IC chip 74a. This prevents the occurrence of parasitic capacitance between the conductive plate 100 and the external connection terminal 71 in the IC card 1 of this embodiment. As a result, it is possible to prevent unintended current from flowing between the external connection terminal 71 and the IC chip 74a while the IC card 1 is performing contactless communication, thereby preventing a decrease in the reliability of the contactless communication.

[0090] (d) Manufacturing method of dual interface IC card 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 conductive paste 12 described above will be described.

[0091] 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.

[0092] 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.

[0093] 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 heat-seal at a predetermined temperature, an adhesive sheet that heat-seals 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 obtained above, in which the cards are arranged in a multi-faceted manner vertically and horizontally, is then punched out using a punching machine to form card base 2, which is the card size specified in ISO / IEC 7816.

[0094] 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.

[0095] Thereafter, a recess 9 for embedding the IC module 70 is formed in the card base 2 by cutting using an end mill. This results in a machined card base 2. The recess 9 is composed of a first recess 91 with a first depth for accommodating the flat substrate 72 of the IC module 70, a second recess 92 with a second depth deeper than the first recess 91 for accommodating the convex IC chip body 74, and a third recess 94. The third recess 94 is filled with a conductive adhesive, which is conductive paste 12, and is used to electrically connect antenna connection terminals 73a and 73b formed on the substrate 72 of the IC module 70 to the first conductive plate 110 and the second conductive plate 120, respectively. The third recess 94 is formed deeper than the first recess 91.

[0096] A predetermined conductive paste 12 is applied to and filled into the third recess 94 of the card base 2 in which the recess 9 is formed. Then, the IC module 70 with the adhesive layer 11 attached is embedded, 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.

[0097] This causes the conductive paste 12 to undergo an appropriate curing reaction, establishing an electrical connection between the IC chip 74a and the conductive plate 100. At the same time, the melting of the adhesive layer 11 establishes 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 application time and heat and 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.

[0098] (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 and contactless communication with external devices, is as follows: The IC card 1 comprises a card base 2 having a recess 9, and an IC module 70 embedded in the recess 9.

[0099] The IC module 70 includes a substrate 72, an IC chip 74a disposed on one surface of the substrate 72, and a plurality of antenna connection terminals 73a, 73b electrically connected to the IC chip 74a. The IC module 70 also includes an external connection terminal 71 disposed on the other surface of the substrate 72 and consisting of a plurality of first terminals electrically connected to the IC chip 74a and a plurality of second terminals not electrically connected to the IC chip 74a. The first terminal refers to any of the above-mentioned C1, C2, C3, C5, and C7 terminals, and the second terminal refers to any of the above-mentioned C4, C6, and C8 terminals.

[0100] 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 antenna connection terminals 73a, 73b and the plurality of conductive plates 100 are electrically connected to each other by a conductive adhesive such as a conductive paste 12. This allows the IC chip 74a and the antenna 80 to form a closed circuit.

[0101] Furthermore, the external connection terminals 71 are exposed on the surface of the card base 2 where the recesses 9 are formed, and when viewed from above, the conductive plate 100 is arranged so that it at least partially overlaps the second terminals but does not overlap the first terminals. By overlapping the conductive plate 100 with the unused second terminals of the external connection terminals 71, the conductive plate 100 can be safely arranged in an area that overlaps with the external connection terminals 71 in the above-mentioned plan view without worrying about a deterioration in communication characteristics. This makes it possible to minimize the distance between the antenna connection terminals 73a and 73b of the IC module 70 and the conductive plate 100, improving the reliability of the electrical connection therebetween.

[0102] The IC card 1 of this embodiment has the above-described configuration, which suppresses the occurrence of parasitic capacitance between the conductive plate 100 and the external connection terminal 71. As a result, it is possible to suppress the unintended flow of current between the external connection terminal 71 and the IC chip 74a while the IC card 1 is performing contactless communication, thereby suppressing a decrease in the reliability of contactless communication.

[0103] 2. Second embodiment of the present disclosure Next, a second embodiment of the present disclosure will be described. Note that in the following embodiments, components similar to those in the first embodiment will be assigned the same reference numerals, and detailed descriptions thereof will be omitted. FIG. 4(a) is a cross-sectional view similar to FIG. 1(b) showing an IC card 1a according to the second embodiment of the present disclosure. FIG. 4(b) is a plan view similar to FIG. 2(a) showing an enlarged view of the recess 9 and its vicinity in the card base 2 of the IC card 1a with the IC module 70 removed. The card base 2 of the IC card 1a according to this embodiment has a similar configuration to that of the IC card 1 according to the first embodiment. However, unlike the IC card 1 according to the first embodiment, the conductive adhesive for electrically connecting the conductive plate 100 and the antenna connection terminals 73a, 73b of the IC module 70 is ACF 13, rather than liquid conductive paste 12. That is, in the IC card 1a, instead of the conductive paste 12 and adhesive layer 11, ACF 13, which has both electrical and mechanical connection functions, is used.

[0104] ACF is an abbreviation for Anisotropic Conductive Film, also known as anisotropic conductive film. ACF 13 is composed of conductive particles 13a, consisting of spherical resin or metal spheres surrounded by a metal film, dispersed in binder resin 13b containing an adhesive component. The conductive particles may be resin coated with nickel or gold, or solder particles. Various solder particles, such as SnPb, SnAgCu, SnCu, SnZnBi, SnAgInBi, and SnZnAl, as well as alloys of these with other metals, can be used.

[0105] The ACF 13 is disposed so as to be sandwiched between a first conductive plate 110 electrically connected to the tip of the antenna wire 83 and an antenna connection terminal 73a formed on the substrate 72 of the IC module 70. At this time, thermal pressure is applied to the substrate 72 from the +Z direction to the -Z direction so as to compress the ACF 13 in the vertical direction.

[0106] As a result, strong thermal pressure is applied to the ACF 13 at a portion sandwiched between the first conductive plate 110 and the antenna connecting terminal 73a, where the gap is particularly narrow, and the conductive particles 13a of the ACF 13 at this portion are pressed from above and below along the thickness direction of the ACF 13. Furthermore, if the conductive particles 13a are small, the conductive particles 13a overlap in a daisy chain manner along the thickness direction of the ACF 13 from the first conductive plate 110 to the antenna connecting terminal 73a. In other words, the first conductive plate 110 and the antenna connecting terminal 73a are electrically connected via the conductive particles 13a.

[0107] On the other hand, between the first conductive plate 110 and the substrate 72 in the region where the antenna connection terminals 73a are not present, the conductive particles 13a are not compressed to the extent that they are pressed from above and below along the thickness direction of the ACF 13, or to the extent that they overlap in a daisy chain fashion. However, the adhesive force of the binder resin 13b generated by the thermal pressure mechanically connects the antenna support layer 6 and the first conductive plate 110 to the substrate 72.

[0108] When ACF 13 is used as the conductive adhesive as in this embodiment, ACF 13 also provides a mechanical connection between the IC module 70 and the card base 2. Therefore, ACF 13 is arranged to cover the entire surface of the first recess 91 of the recess 9. To ensure good conductivity between the antenna connection terminal 73a of the IC module 70 and the first conductive plate 110, the distance between the antenna connection terminal 73a and the first conductive plate 110 must be slightly smaller than the diameter of the conductive particles 13a. The diameter of the conductive particles 13a is typically 10 μm or more and 100 μm or less. Therefore, when viewed in the thickness direction of the card base 2, the first conductive plate 110 must be positioned close to the back surface, i.e., the lower surface, of the substrate 72.

[0109] The same applies to the electrical and mechanical connection between the second conductive plate 120 and the terminal 73b by the ACF 13 as described above for the electrical and mechanical connection between the first conductive plate 110 and the antenna connecting terminal 73a formed on the substrate 72 by the ACF 13. Also, although the ACF 13 is tape-shaped, ACP (Anisotropic Conductive Paste) can be used instead.

[0110] The first conductive plate 110 and the second conductive plate 120, which are the conductive plate 100, are both substantially rectangular plate-like 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, the IC card 1. As shown in Fig. 4(b) , the first conductive plate 110 and the second conductive plate 120 have a region that overlaps with the first recess 91 in the plan view, i.e., a region that is exposed from the card base 2, and a region that is located outside the first recess 91 and is embedded inside the card base 2.

[0111] In the plan view, lines overlapping an edge 93a on the −X direction side along the Y axis and an edge 93b on the +X direction side of the outer periphery 93 of the recess 9 are defined as lines m1 and m2, respectively. Also, in the plan view, a line overlapping an edge 93c on the −Y direction side along the X axis of the outer periphery 93 of the recess 9 is defined as line m3. In this case, a region of the first conductive plate 110 on the +X direction side of line m1 and on the +Y direction side of line m3 is exposed from the card base 2 in the first recess 91.

[0112] On the other hand, the area on the −X side of line m1 and the area on the −Y side of line m3 are covered by the card base 2. Similarly, the area of ​​second conductive plate 120 on the −X side of line m2 and on the +Y side of line m3 is exposed from the card base 2 in first recess 91. On the other hand, the area on the +X side of line m2 and the area on the −Y side of line m3 are covered by the card base 2.

[0113] Taking the first conductive plate 110 as an example, the width along the X-axis direction of the first conductive plate 110 exposed from the card base 2 in the first recess 91 is W12, the same as the width of the first recess 91, and is narrower than the width W11 including the width of the portion covered by the card base 2. Furthermore, the vertical width along the Y-axis direction of the first conductive plate 110 exposed from the card base 2 in the first recess 91 is W22, the same as the width of the first recess 91, and is narrower than the width W21 including the width of the portion covered by the card base 2. While the sizes and ratios of W12, W11, W22, and W21 are arbitrary, it is preferable that the area of ​​the antenna connection terminal 73a when the IC module 70 is mounted be included within the area surrounded by the vertical width W22 and horizontal width W12 of the first conductive plate 110. This ensures a stable contact area for electrical connection between the antenna connection terminal 73a and the first conductive plate 110. The same applies to the second conductive plate 120.

[0114] The first conductive plate 110 and the second conductive plate 120 are partially covered by the card base 2, which enhances the effect of holding the conductive plates against external forces such as the cutting resistance of the end mill blade when forming the recesses 9. As a result, the conductive plates can be prevented from accidentally shifting position or peeling off from the card base 2.

[0115] The IC card 1a of this embodiment also suppresses the occurrence of parasitic capacitance between the conductive plate 100 and the external connection terminal 71. As a result, it is possible to suppress the unintended flow of current between the external connection terminal 71 and the IC chip 74a while the IC card 1a is performing contactless communication, thereby suppressing a decrease in the reliability of contactless communication.

[0116] It goes without saying that an IC module having a configuration similar to that of IC module 70a described as a modified example of the first embodiment can also be applied to this embodiment. Furthermore, as will be described in detail in the third embodiment below, the same effects as those described above can be obtained by providing a bellows wiring section having a repeated folded structure (a so-called bellows shape or zigzag shape) at each end of antenna wire 83 instead of conductive plate 100 in IC cards 1 and 1a of the first and second embodiments. This is because such a bellows wiring section functions as a pseudo-conductive plate.

[0117] 3. Third embodiment of the present disclosure Next, a third embodiment of the present disclosure will be described. Fig. 7(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. 7(b) is a cross-sectional view corresponding to Fig. 1(b) of the IC card 1b of Fig. 7(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. 8 is a plan view corresponding to Fig. 2(a), enlarging the vicinity of the recess 9 of the card base 2 with the IC module 70 removed.

[0118] 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 line in FIG. 7(a). The antenna wire 83 is wound one or more times around the periphery of the substantially rectangular card, and both ends thereof each form a bellows wiring section 100a having a repeated folded structure. When the bellows wiring section 100a 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.

[0119] Antenna connection terminals 73a and 73b are provided on the surface of the substrate 72 of the IC module 70 facing the card base 2, and are electrically connected to the IC chip 74a contained therein. As shown in FIG. 7B, the antenna connection terminal 73a of the IC module 70 is electrically connected to the first bellows wiring portion 130 exposed from the third recess 94 via a conductive adhesive such as conductive paste 12. This electrically connects the antenna connection terminals 73a and 73b to the multiple bellows wiring portions 100a, i.e., the first bellows wiring portion 130 and the second bellows wiring portion 140, respectively, via the conductive adhesive, thereby forming a closed circuit between the IC chip 74a and the antenna 80b. The bellows wiring portion 100a is embedded deeper than the bottom surface of the first recess 91. When forming the third recess 94, which is deeper than the first recess 91, by cutting or the like, cutting the upper end of a portion of the bellows wiring portion 100a allows a portion of the bellows wiring portion 100a to be properly exposed.

[0120] At this time, the external connection terminals 71 are exposed on the surface of the card base 2 on which the recesses 9 are formed. Also, when viewed in a plan view from the +Z direction, the bellows wiring portion 100a is positioned so as to at least partially overlap with the C4 terminal or C8 terminal, which is an unused terminal according to the standard, as with the conductive plate 100. Furthermore, the bellows wiring portion 100a is positioned so as not to overlap with terminals used for contact communication according to the standard, such as the C1 terminal, C2 terminal, C3 terminal, C5 terminal, and C7 terminal.

[0121] As described above, the IC card 1b 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 suppresses the generation of parasitic capacitance between the bellows wiring section 100a, which has the same function as the conductive plate 100, and the external connection terminals 71. When viewed from a plane in the +Z direction, the bellows wiring section 100a and the external connection terminals 71 overlap only with unused terminals of the external connection terminals 71 that are not electrically connected to the IC chip 74a. This is because such unused terminals are isolated from the circuit, making it difficult for electric charge to accumulate and for AC current to flow.

[0122] By overlapping the bellows wiring portion 100a with the unused terminals of the external connection terminal 71, the bellows wiring portion 100a can be safely arranged in an area where it overlaps with the external connection terminal 71 in the plan view, without worrying about a deterioration in communication characteristics. This makes it possible to minimize the distance between the antenna connection terminals 73a, 73b of the IC module 70 and the bellows wiring portion 100a, improving the reliability of the electrical connection therebetween.

[0123] As described above, the IC card 1b of this embodiment can prevent current from unintentionally flowing between the external connection terminal 71 and the IC chip 74a during contactless communication, and can prevent a decrease in the reliability of contactless communication.

[0124] Note that, when the bellows wiring portion 100a is viewed in a plan view along the Z-axis direction, the ratio of the area of ​​the bellows wiring portion 100a to the area of ​​the third recess 94 visible from the third recess 94 is preferably 30% or more, and more preferably 50% or more. The former condition allows the bellows wiring portion 100a to form a good capacitance component together with the C4, C8 terminals, etc. The latter condition not only allows the bellows wiring portion 100a and the C4, C8 terminals, etc. to form a good capacitance component, but also improves the reliability of the electrical connection with the antenna connection terminals 73a, 73b via conductive paste, etc.

[0125] In this embodiment as well, the means for electrically connecting the IC module 70 and the antenna 80b is not limited to conductive paste, and needless to say, ACF may also be used. [Explanation of symbols]

[0126] 1, 1a, 1b, 1p IC card 2, 2p card base 3, 8 oversheet layers 4, 7 Core layer 5, 6 Antenna support layer 9 Recess 11 Adhesive layer 12 Conductive paste 13 ACF 13a Conductive particles 13b Binder resin 14 Antenna sheet 70, 70a, 70p IC modules 71 External connection terminal 72 PCB 73a, 73b Antenna connection terminals 73c, 73d, 73e, 73f lead wires 74 IC chip body 74a IC chip 74b molded part 74p Pad 75 wire 76 Bonding Hole 80, 80b, 80p antennas 83 Antenna Wire 91 First recess 92 Second recess 93 Outer circumference Areas 93a, 93b, and 93c 94 Third recess 100, 100p conductive plate 100a bellows wiring section 110 First conductive plate 120 Second 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; an IC module embedded in the recess; an antenna disposed inside the card base, The IC module comprises a substrate, an IC chip disposed on one surface of the substrate and a plurality of antenna connection terminals electrically connected to the IC chip, and an external connection terminal disposed on the other surface of the substrate and consisting of a plurality of first terminals electrically connected to the IC chip and a plurality of second terminals not electrically connected to the IC chip; 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 antenna connection terminals and the plurality of capacitance forming portions are electrically connected to each other by a conductive adhesive, 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 the conductive adhesive is an anisotropic conductive film.

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

5. 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.

6. a conductive lead wire is disposed on the one surface of the substrate; The antenna connection terminal is provided at one end of the lead wire, and the other end is electrically connected to a metal bump or an end of a metal wire that is electrically connected to an electrode of the IC chip, 2. The dual interface IC card according to claim 1, wherein the lead wires overlap the first terminals and the second terminals when viewed from the surface.

7. An IC module used in a dual interface IC card capable of contact communication and contactless communication with an external device, The IC module comprises a substrate, an IC chip disposed on one surface of the substrate and a plurality of antenna connection terminals electrically connected to the IC chip, and an external connection terminal disposed on the other surface of the substrate and consisting of a plurality of first terminals electrically connected to the IC chip and a plurality of second terminals not electrically connected to the IC chip; When viewed from the other surface, the antenna connection terminal at least partially overlaps the second terminal but does not overlap the first terminal.

8. a conductive lead wire is disposed on the one surface of the substrate; The antenna connection terminal is provided at one end of the lead wire, and the other end is electrically connected to a metal bump or an end of a metal wire that is electrically connected to an electrode of the IC chip, 8. The IC module according to claim 7, wherein the lead wires at least partially overlap the first terminals when viewed from the other surface.

Images