IC card

Abstract

To provide an IC card which can be easily selectively used by a user and is superior in durability and can be prevented from skimming.SOLUTION: An IC card 1 capable of non-contact communication comprises a card substrate 2, an IC chip and antenna 80, and an optical switch circuit 200 which is disposed in series to a communication circuit formed of the IC chip and antenna 80 and can select whether or not to close the communication circuit. The optical switch circuit 200 comprises: a photoelectric element 210 which converts prescribed incident light to a voltage corresponding to a level of the incident light; and a switch element which sets the communication circuit to an open state to disable communication when the generated voltage is lower than a prescribed value, and sets the communication circuit to a closed state to enable communication when the generated voltage is equal to or higher than the prescribed value. The photoelectric element 210 is arranged in the card substrate 2 so that it is at least partially exposed to a surface of the card substrate 2 or it can receive incident light from the outside through a layer having transparency.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an IC card capable of non-contact communication with an external device.

Background Art

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

[0003] By the way, non-contact IC cards and dual interface IC cards have a coil antenna electrically connected to an IC chip inside the card substrate. When an electromagnetic wave of a predetermined frequency is emitted from the outside, this antenna excites an induced electromotive force by crossing the magnetic field formed by this electromagnetic wave. When the current generated by the induced electromotive force flows into the IC chip, the IC chip operates and can perform non-contact communication with an external reader or the like. However, this non-contact communication is performed regardless of the user's intention. Therefore, for example, when a newly issued card is mailed from a card company to a user, there is a possibility that the card may be read by using a non-contact communication reader / writer from the outside of the envelope by a malicious person, and personal information or the like may be stolen (skimming).

[0004] Furthermore, if a user carries a contactless IC card in their wallet when going out, there is a possibility that the information on the contactless IC card may be read or a payment processed against the user's will, for example, at a train station ticket gate or a store exit. Therefore, it is preferable that the IC card can only be used when the user intends to.

[0005] Incidentally, Reference 1 describes a contactless IC card in which the conductive parts and wiring of each contact point of the switching unit are electrically connected, and these wirings are connected to each terminal of the antenna, so that one of several IC chips can be electrically connected to the antenna via the switching unit. A light-shielding part is attached around the switching unit body to block the light from the light-emitting element (EL element). This light-shielding part is attached concentrically around the switching unit body and extends perpendicular to the axis of rotation. The light-shielding part has a shape in which a part of the disc is cut out, and when this cutout is located below the light-emitting element provided inside the card substrate, it blocks the light emitted from the light-emitting element. In other words, by rotating the switching unit, the amount of light passing through the light-shielding part can be adjusted, thereby adjusting the output voltage from the solar cell and selecting the IC chip. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2006-127483 [Overview of the project] [Problems that the invention aims to solve]

[0007] While a configuration that enables contactless communication only when the user intentionally uses the IC card is preferable, those with mechanical switches have a complex structure, are prone to failure, and require cumbersome user operation. Therefore, the challenge is to provide an IC card that allows for easy user selection, is highly durable, and can suppress skimming. [Means for solving the problem]

[0008] The IC card according to this embodiment, which has a first configuration capable of contactless communication with an external device, comprises a card base, an IC chip disposed inside the card base and an antenna electrically connected to the IC chip, and an optical switch circuit disposed in series with the communication circuit formed by the IC chip and the antenna, and capable of selecting whether or not to close the communication circuit, wherein the optical switch circuit comprises a photoelectric element that converts a predetermined incident light into a voltage corresponding to the level of the incident light, and a switch element that puts the communication circuit into an open state where communication is impossible when the voltage generated by the photoelectric element is lower than a predetermined value, and into a closed state where communication is possible when the voltage generated by the photoelectric element is equal to or greater than a predetermined value, wherein the photoelectric element is disposed on the card base such that at least a part of it is exposed on the surface of the card base, or so that it can receive incident light from the outside through a transparent layer.

[0009] Furthermore, in a second configuration of an IC card according to another form of this implementation, the photoelectric element and the switching element in the first configuration may each include a solar cell and a MOSFET.

[0010] Furthermore, the third configuration of the IC card in another form of this implementation may be a dual-interface IC card in the first or second configuration.

[0011] Furthermore, in a fourth configuration of an IC card in another form of this implementation, in any of the first to third configurations, a light-shielding label may be affixed to the surface of the card base so as to cover the photoelectric element when not in use or unused.

[0012] Furthermore, in a fifth configuration of an IC card according to another form of this embodiment, in any of the first to fourth configurations, the optical switch circuit is composed of a first optical switch circuit and a second optical switch circuit arranged in series with the communication circuit, and the communication circuit may become able to communicate when both the first switch element, which is the switch element of the first optical switch circuit, and the second switch element, which is the switch element of the second optical switch circuit, are in a closed state.

[0013] Furthermore, in a sixth configuration of an IC card according to another form of this embodiment, in the fifth configuration, the first photoelectric element, which is a photoelectric element of the first optical switch circuit, and the second photoelectric element, which is a photoelectric element of the second optical switch circuit, may be arranged on the card substrate such that at least a portion of them are exposed to the surface of the card substrate with respect to opposite surfaces of the card substrate, or so that they can receive incident light from the outside through a transparent layer. [Effects of the Invention]

[0014] According to this embodiment, it is possible to provide an IC card that allows users to easily select which type to use, has excellent durability, and can suppress skimming. [Brief explanation of the drawing]

[0015] [Figure 1] These are a plan view and a cross-sectional view illustrating the structure of an IC card according to the first embodiment. [Figure 2] This is an enlarged view of the area around the IC module mounting position in Figure 1(a), with the IC module removed. [Figure 3] This diagram illustrates the configuration of the IC module and the details of its connection to the card base. [Figure 4] This is a cross-sectional view illustrating the configuration of an optical switch circuit, including a modified example. [Figure 5] This is a circuit diagram illustrating an optical switch circuit. [Figure 6] It is a plan view for explaining the structure of an IC card according to the second embodiment. [Figure 7] It is a plan view for explaining the structure of an IC card according to the third embodiment.

Modes for Carrying Out the Invention

[0016] Hereinafter, an example of an IC card of the present disclosure will be described with reference to the drawings and the like. However, the IC card of the present disclosure is not limited to the embodiments and examples described below.

[0017] In addition, each of the drawings shown below is schematically shown. Therefore, the size and shape of each part are exaggerated as appropriate for easy understanding. Also, in each drawing, the hatching showing the cross section of the member is appropriately omitted. The numerical values and material names of the dimensions and the like of each member described in this specification are examples as embodiments, and are not limited thereto, and can be appropriately selected and used. In this specification, terms specifying shapes and geometric conditions, such as terms like parallel, orthogonal, and perpendicular, include not only the strictly meant state but also substantially the same state.

[0018] 1. First Embodiment An example of the first embodiment of the IC card of the present disclosure will be described. The IC card 1 according to the first embodiment is a dual interface IC card. Here, for convenience of explanation, an XYZ coordinate system is set for the IC card 1. First, as shown in FIGS. 1(a) and 1(b) and the like, the Z axis is taken in the normal direction of the main surface of the IC card 1. Then, from the main surface on the side where the external connection terminal 71 of the IC module 70 is not arranged, the direction from the main surface on the side where the external connection terminal 71 is arranged is taken as the +Z direction or the upper direction in the thickness direction, and the opposite direction is taken as the -Z direction or the lower direction in the thickness direction.

[0019] When viewing the IC card 1 from the +Z direction, take the two short sides of the IC card 1 and the straight line perpendicular to the Z axis as the X axis. Also, take the direction from one short side closer to the external connection terminal 71 to the other short side as the +X direction or the right direction, and the opposite direction as the -X direction or the left direction. Further, take the axis perpendicular to the X axis and the Z axis as the Y axis, and take the direction from one long side farther from the external connection terminal 71 to the other long side as the +Y direction or the upward direction, and the opposite direction as the -Y direction or the downward direction.

[0020] Here, Fig. 1(a) is a plan view of the IC card 1 viewed from the +Z direction, and Fig. 1(b) is a view of the cross-section cut along the A-A line parallel to the X axis in the vicinity of the IC module 70 of the IC card 1 in Fig. 1(a), viewed from the -Y direction. Fig. 2 is a view showing the state of the card substrate 2 side in an enlarged state near the IC module 70 of the IC card 1 in Fig. 1(a) and with the IC module 70 removed. Also, Fig. 4(a) is a view of the cross-section cut along the B-B line parallel to the X axis in the vicinity of the optical switch circuit 200 of the IC card 1 in Fig. 1(a), viewed from the -Y direction, and Fig. 4(b) is a view showing a variation thereof.

[0021] As shown in Fig. 1(a), the IC card 1 has a form of a substantially rectangular thin plate with rounded corners in a plan view from the +Z direction side. Also, on the surface of the IC card 1 on the +Z direction side, the IC module 70 including the external connection terminal 71 can be visually recognized slightly above and to the left of the center, that is, closer to the -X direction and closer to the +Y direction than the center. As shown in Fig. 1(b), the IC module 70 is embedded in the recess 9 formed in the card substrate 2 and is arranged such that the surface on the +Z direction side of the external connection terminal 71 is substantially flush with the surface on the +Z direction side of the card substrate 2. Such a form of the IC card 1 conforms to ISO / IEC7816, which is an international standard for IC cards.

[0022] On the other hand, on the surface of the IC card 1 on the +Z side, a portion of the optical switch circuit 200 is visible, with the photoelectric element 210 exposed slightly to the lower right of the center, i.e., closer to the +X and -Y directions than the center. The optical switch circuit 200, like the IC module 70, is embedded in a recess 94 formed in the card base 2, and is positioned so that the surface of the photoelectric element 210 on the +Z side is substantially flush with the surface of the card base 2 on the +Z side. However, the optical switch circuit 200 is not limited to this configuration, and as will be described later, the entire surface of the optical switch circuit 200, including the photoelectric element 210, may be covered with a transparent substrate. Furthermore, the arrangement of the optical switch circuit 200 when the IC card 1 is viewed from above can be any location as long as it does not overlap with the IC module 70.

[0023] As shown in Figure 1(b), the card base 2 constituting the card body of the IC card 1 is formed by laminating and integrating an oversheet layer 8, an inner layer 7, antenna holding layers 6 and 5, an inner layer 4, and an oversheet layer 3 in that order from the -Z direction. Typically, the oversheet layers 8 and 3 are made of transparent substrates, and the inner layers 7 and 4 and antenna holding layers 6 and 5 are made of white substrates, but this is not limited to this. In addition, the antenna wire 83 constituting the antenna 80 is positioned between the antenna holding layers 5 and 6 so as to be sandwiched between them.

[0024] At both ends of the antenna wire 83 constituting the antenna 80, a first plate 110 and a second plate 120 are welded as end plates 100, which are rectangular metal conductive plates. The substrate 72 of the IC module 70 is mounted in the first recess 91 of the card base 2, which is cut relatively shallowly, and the lower surface of the substrate 72 is in contact with the upper surface of the first recess 91. Furthermore, in the first recess 91, the first plate 110 and the second plate 120, which are electrically connected to the antenna 80, are exposed toward the opening side of the recess 9. By forming a conductive adhesive layer 11 containing conductive particles, for example, in the first recess 91, the electrical contacts of the IC module 70 can be electrically connected to the first plate 110, etc. As a result, the IC module 70 and the antenna 80 can form a contactless communication circuit.

[0025] On the other hand, as shown in Figures 1(a) and 4(a), an optical switch circuit 200 is connected in series with the non-contact communication circuit formed by the IC module 70 and the antenna 80, and can select whether or not to close the communication circuit. The optical switch circuit 200 has a switching function that allows it to transition to either a closed state in which the communication circuit can communicate or an open state in which the communication circuit cannot communicate, depending on predetermined conditions of incident light. The optical switch circuit 200 includes a photoelectric element 210 that converts predetermined incident light into a voltage corresponding to the level of the incident light. The photoelectric element 210 controls the circuit to open when the voltage generated is lower than a predetermined value, and to close when the generated voltage is equal to or greater than the predetermined value. Since the switching operation of such an optical switch circuit 200 can be realized by a non-contact device such as a MOSFET or a phototransistor, durability can be obtained compared to mechanical contacts, and a configuration that is less prone to failure can be made.

[0026] Let's assume that the predetermined incident light conditions for the photoelectric element 210 to perform such switching operations in the optical switch circuit 200 are, for example, an amount of incident light in a predetermined frequency range in the visible light region. In this case, in the IC card 1 of the first embodiment, if the amount of predetermined incident light irradiating the photoelectric element 210 of the optical switch circuit 200 is small, for example, if the IC card 1 is sealed in an envelope and being sent to the user, or if the user has the IC card 1 in their wallet, the IC card 1 will not perform contactless communication. On the other hand, if the user takes the IC card out of their wallet in a store or the like, and the photoelectric element 210 is sufficiently irradiated with the predetermined incident light, the IC card 1 will perform contactless communication normally. Therefore, in this embodiment, it is possible to provide an IC card that allows for easy selection of use by the user, has excellent durability, and can suppress skimming.

[0027] The configuration of the IC card 1 of this embodiment and the details of its manufacturing method are described below.

[0028] (a) Card base Card base 2 refers to the card body excluding the IC module 70, which constitutes the IC card 1, a dual-interface IC card. As described above, card base 2 typically has a configuration in which an oversheet layer 8, an inner layer 7, antenna holding layers 6 and 5, an inner layer 4, and an oversheet layer 3 are stacked in this order from one end on the -Z direction side in the thickness direction. An antenna 80, formed from a covered conductor or the like and wound in a loop shape, is positioned between the antenna holding layers 6 and 5. Card base 2 may refer to both the card before the recess 9 is formed and the card base after the recess 9 is formed, and may refer to both the card without the antenna 80 and the card with the antenna 80. In addition, a first plate 110 and a second plate 120 are welded to the start and end points of the antenna 80 as plate-shaped ends 100.

[0029] However, the layer configuration of the card base 2 is not limited to this, and may consist of three layers: an oversheet layer, an inner layer, and another oversheet layer, or six layers: an oversheet layer, four inner layers, and another oversheet layer. The inner layer may also consist of multiple layers as appropriate. Furthermore, printing or a magnetic stripe may be embedded on the surface of the oversheet layer 3 or 6 of the card base 2 that is opposite to the inner layer 4 or 5, and printing may be applied to the surface of the inner layer 4 or 5 adjacent to the oversheet layer 3 or 6.

[0030] From the standpoint of conforming to standards such as ISO / IEC 7810, the thickness of the card base 2 is preferably 0.76 mm or more and 0.84 mm or less, but it may be outside this range.

[0031] (i) Inner layer The inner layer is also called the core layer. A wide variety of white or colored plastic sheets can be used for inner layers 4 and 7, and the following single films or composite films thereof can be used. For example, polyethylene terephthalate (PET), PET-G (terephthalic acid-cyclohexanedimethanol-ethylene glycol copolymer), polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polycarbonate, polyamide, polyimide, cellulose diacetate, cellulose triacetate, polystyrene-based materials, ABS, polyacrylic acid ester, polypropylene, polyethylene, polyurethane, etc. The thickness of inner layers 4 and 7 can be appropriately selected considering the overall thickness of the card, but for example, it can be between 0.10 mm and 0.38 mm.

[0032] (ii) Antenna holding layer The antenna retaining layer is also called the core layer, similar to the inner layer. The antenna retaining layers 5 and 6 have the function of sandwiching and holding the antenna 80, and a wide range of plastic sheets similar to those used for the inner layers 4 and 7 can be used. The antenna retaining layers 5 and 6 may be made of the same material as the inner layers 4 and 7, or they may be made of different materials. The thickness of the antenna retaining layers 5 and 6 can be appropriately selected considering the overall thickness of the card, but for example, it can be between 0.10 mm and 0.38 mm.

[0033] (iii) Oversheet layer For the oversheet layers 3 and 8, the same material as the inner layer and antenna retaining layer is usually used, but transparent materials with a thickness of approximately 0.05 mm or more and 0.10 mm or less are often used. From the viewpoint of preventing curling when the laminate of the inner layer, antenna retaining layer and oversheet layer is integrated by heat pressing or the like, it is preferable that the thicknesses of the oversheet layers 3 and 8 are the same, but they do not necessarily have to be the same. This point also applies to the inner layers 4 and 7 and the antenna retaining layers 5 and 6 mentioned above.

[0034] The material of the oversheet layer can be any material that adheres when heated, but even if the oversheet layer itself does not adhere when heated, the two can be integrated by adding a layer of a known adhesive that generates adhesive force when heated between the inner layer and the oversheet layer. Furthermore, when the IC card 1 is used as a magnetic card, a magnetic stripe may be pre-embedded in either or both of the oversheet layers 3 and 8 on the main surface side opposite to either or both of the inner layers 4 and 7 by thermal transfer or the like.

[0035] (iv) Antenna sheet In this embodiment, as will be described later, an antenna 80 is formed on one surface of the antenna holding layer 5 or 6, and both ends of the antenna wire 83 constituting the antenna 80 are electrically connected to the first plate 110 and the second plate 120, which are plate-shaped conductive end portions 100. The formation of the antenna 80 on the antenna holding layer 5 or 6 is carried out, for example, as follows. First, the first plate 110 and the second plate 120 are bonded and fixed to the surface of the antenna holding layer 6 facing the antenna holding layer 5 by applying heat and pressure or the like. At this time, adhesive may be applied to the surface of the antenna holding layer 6 before placing the first plate 110 and the second plate 120. The first plate 110 and the second plate 120 are arranged side by side in the left-right direction at the planned mounting position of the IC module 70, and a portion of them is positioned to overlap with the terminals 73a and 73b of the IC module 70 when mounted.

[0036] Subsequently, the tip of the antenna wire 83 is welded to either the first plate 110 or the second plate 120. Then, starting from this point, a predetermined heat pressure is applied to the antenna wire 83, and the insulated conductor, the antenna wire 83, covered with an insulating material, is embedded into the surface of the antenna holding layer 6 by a winding machine. That is, while applying a predetermined heat pressure to the antenna wire 83, the antenna supply head is drawn in a loop shape as shown in Figure 1(a), and the antenna wire 83 supplied from the antenna supply head is sequentially embedded into the antenna holding layer 6. The embedded antenna wire 83 is cut, and the tip of the cut antenna wire 83 is welded to the other of the first plate 110 or the second plate 120, using the cut tip as the endpoint. For the sake of simplicity, the process of connecting the optical switch circuit 200 and the antenna wire 83, which will be described later, is not mentioned here.

[0037] The starting and ending ends of the antenna wire 83 are electrically connected to either the first plate 110 or the second plate 120 by welding. In this way, an antenna holding layer 6 (antenna sheet 12) on which the antenna 80 is formed is obtained. The intermediate product in which the antenna 80 is embedded in the antenna holding layer 5 or 6 is sometimes referred to as the antenna sheet 12. The antenna sheet 12 can be distributed to the market as a component for manufacturing the IC card 1 on its own. Alternatively, a business model may exist in which sheet material such as the antenna holding layer is supplied to a processing company, which processes it into an antenna sheet 12 and delivers it to the supplier.

[0038] (v) antenna In the antenna 80 formed in the antenna holding layer 5 or 6, the terminals 73a and 73b of the IC module 70 are electrically connected to the first plate 110 and the second plate 120, which are a pair of ends 100 to which multiple ends of the antenna wire 83 are electrically connected. In this way, the IC chip and antenna 80 of the IC module 70 constitute a contactless communication circuit. This communication circuit may perform proximity communication using, for example, the 13.56 MHz HF frequency band specified in ISO / IEC 18092 or ISO / IEC 144443. Alternatively, it may perform communication using other frequencies, such as the 920 MHz UHF frequency band, the 125 kHz LF frequency band, or the 2.45 GHz microwave frequency band.

[0039] When IC card 1 is held over an external device such as a reader / writer, the communication circuit generates an electromotive force or current due to the magnetic field or radio waves formed by the reader / writer, supplying power to the IC chip. This enables the IC chip to be driven, allowing for contactless transmission and reception of information with the reader / writer, and enabling reading and writing of information to and from the memory.

[0040] The antenna wire 83 constituting the antenna 80 is typically formed from a coated conductor, in which a copper wire is covered with an insulating material. In addition, copper alloy wires such as Cu-Ni, Cu-Cr, Cu-Zn, Cu-Sn, and Cu-Be, or various metal wires and metal alloy wires such as iron, stainless steel, and aluminum can also be selected. By using coated conductors, the IC card 1 can be manufactured at a lower cost compared to methods such as copper foil etching. However, the IC card 1 of this disclosure may also use antenna wires formed by copper foil etching or metal foil punching.

[0041] The diameter of the antenna wire 83 is not particularly limited as long as it ensures the characteristics of a non-contact communication circuit, but for example it can be 0.03 mm or more and 0.30 mm or less, preferably 0.05 mm or more and 0.15 mm or less. By using the latter range, durability against heat and pressure from embedding and external forces from cutting can be improved, and good communication characteristics can be ensured.

[0042] (vi) Ends (first plate and second plate) Next, the details of the configuration of the conductive end portion 100, consisting of the first plate 110 and the second plate 120, will be described. Both the first plate 110 and the second plate 120 are substantially rectangular plate-shaped members in a plan view along the Z-axis direction, which is the normal direction to the main surface of the IC card 1. As shown in Figure 1(b), the first plate 110 and the second plate 120 have, in this plan view, a region that overlaps with the first recess 91, that is, a region exposed from the card base 2, and a region located outside the first recess 91 and embedded inside the card base 2.

[0043] In other words, as shown in Figure 2, in the plan view, the lines that overlap the -X-direction side 93a and the +X-direction side 93b of the outer circumference 93 of the recess 9 along the Y-axis are denoted as lines m1 and m2, respectively. In this case, the region of the first plate 110 on the +X-direction side of line m1 is exposed from the card base 2 in the first recess 91, and the region on the -X-direction side of line m1 is covered by the card base 2. Similarly, the region of the second plate 120 on the -X-direction side of line m2 is exposed from the card base 2 in the first recess 91, and the region on the +X-direction side of line m2 is covered by the card base 2.

[0044] Taking the first plate 110 as an example, the width of the first plate exposed from the card base 2 in the first recess 91 along the X-axis direction is W12, the same as the width of the first recess 91, and is narrower than the width W11 including the covering portion by the card base 2. Also, the height of the first plate exposed from the card base 2 in the first recess 91 along the Y-axis direction is W2. The sizes and ratios of W12, W11, and W2 are arbitrary, but it is preferable that the area of ​​the terminals 73a when the IC module 70 is mounted is included within the area of ​​the first plate 110 with a height of W2 and a width of W12. This is because a stable contact area for electrical connection between the terminals 73a and the first plate 110 can be obtained. The same applies to the second plate 120.

[0045] Furthermore, because a portion of the first plate 110 and the second plate 120 are covered by the card base 2 in this manner, the holding effect of the first plate 110 and the second plate 120 against external forces such as the cutting resistance of the end mill blade when forming the recess 9 is enhanced. Therefore, the plates are less likely to detach from the card base 2 and become misaligned.

[0046] Furthermore, as mentioned above, the first plate 110 and the second plate 120 have a laminated structure including at least two layers: a first member 111 and a second member 112 laminated on the +Z side of the first member 111. In this case, it is preferable that the second member 112 is a material that is less susceptible to oxidation than the first member 111. A material that is less susceptible to oxidation can be rephrased as, for example, if both the first member 111 and the second member 112 are metals, then the second member 112 is a metal with a lower ionization tendency than the first member 111. As an example of such metals, the first member 111 can be aluminum, iron, nickel, or copper, and the second member 112 can be silver, palladium, platinum, or gold.

[0047] Considering the ease of material procurement, cost, processability, and electrical properties, it is preferable to use highly conductive copper as the first component 111 and silver plating as the second component 112 among those listed above. This is because by using copper, which can ensure sufficient conductivity, as the first component 111, and using silver, which is resistant to oxidation and easily exposes the metal interface when cutting the resin layer with an end mill, as the plating for the second component 112, it is possible to obtain good electrical properties and processability while suppressing cost increases.

[0048] On the other hand, the first plate 110 and the second plate 120 do not have the laminated structure of two or three or more layers described above, and may be made of only a single material. In this case, the single material is limited to a conductive material, and for example, the materials described above as the first material 111 and the second material 112, or their alloys, can be used. Preferably, highly conductive materials such as copper, aluminum, or stainless steel can be selected. Using a single material makes material procurement and processing easier and leads to cost reduction.

[0049] In this embodiment, as described above, the configuration in which multiple ends of the antenna wire 83 are welded to a pair of end plates 100, namely the first plate 110 and the second plate 120, is explained. However, it is not necessarily required that the ends of the antenna wire 83 be connected to such plates. For example, the multiple ends of the antenna wire can be folded back multiple times in a zigzag, meander, or bellows shape, thereby performing the same function as the plates described above. Alternatively, the IC module and the antenna wire on the card side may not be physically joined, and a first coil electrically connected to the IC chip may be formed on the IC module side, and a second coil opposite to it may be formed on the card base side, with the second coil connected to the antenna of the card base. In this case, the first coil and the second coil are electromagnetically coupled, enabling contactless communication of the IC card using a booster method in which the antenna of the card base operates as a booster antenna.

[0050] (b) IC module Next, the main components of the IC module 70 will be explained, primarily based on Figures 1(b) and 3. Figure 3(a) is a view of the IC module 70 from the +Z direction, towards the external connection terminal 71, similar to Figure 1(a). Figure 3(b) is a view of the IC module 70 from the -Z direction, opposite to that of Figure 3(a). Here, most of the molded portion 74b of the IC chip body 74 is omitted in order to allow for a view of the interior. Figure 3(c) is an enlarged cross-sectional view of section C near terminal 73a in Figure 1(b).

[0051] The IC module 70 is embedded in a recess 9 formed in the card base 2, and terminals 73a and 73b of the IC module 70 are electrically connected to the first plate 110 and the second plate 120 of the antenna 80, respectively, thereby forming a contactless communication circuit. At this time, contact communication with a contact-type reader / writer, etc., can be performed through the external connection terminal 71 provided on the IC module 70.

[0052] The substrate 72 is formed by bonding copper foil to both sides of a flexible insulating resin film, such as glass epoxy resin or polyimide resin, via an adhesive, and leaving some of the copper foil bonded to the resin film to form a predetermined pattern. Specifically, the process involves sequentially applying a photosensitive material, placing a film plate with the predetermined pattern, exposure, and etching away the non-photosensitive areas, so that an external connection terminal 71 is formed on one copper foil surface of the resin film and terminals 73a and 73b are formed on the other copper foil surface. This forms a substrate 72 in which some of the copper foil with the predetermined pattern remains on both sides of the resin film. In addition, the substrate 72 is pre-provided with multiple bonding holes 76, which are through holes for wire bonding to the external connection terminal 71.

[0053] As shown in Figure 3(a), the external connection terminal 71 has defined sections for each external terminal as defined by the ISO / IEC 7816-2 standard. Each of these sections and the IC chip 74a are connected by wires 75, such as gold wire, through the bonding holes 76 provided in the substrate 72, as shown in Figure 3(b). Similarly, terminals 73a and 73b are connected to the IC chip 74a by wires 75. These bonding holes 76 and wires 75 are covered and protected by the molded section 74b.

[0054] The IC chip body 74 is positioned on the side of the substrate 72 opposite to the surface where the external connection terminals 71 are formed. The IC chip body 74 consists of an IC chip 74a bonded and fixed to the substrate 72 via adhesive, bonding wires 75 for connection, and a molded part 74b which is a sealing resin to protect them. The IC chip 74a includes a CPU for controlling the operation of both contact and contactless communication, and a storage device such as RAM, ROM, EEPROM, or flash memory. Furthermore, the IC chip 74a includes various circuits such as an interface circuit and a power generation circuit for decoding input signals and generating output signals for contact and contactless communication. Note that these various circuits may be provided as separate elements from the IC chip 74a.

[0055] The molded portion 74b is provided as a protruding part that covers the IC chip 74a and wire 75 in order to protect them from external forces and environmental loads. A UV-curable resin or a thermosetting resin is used for the molded portion 74b.

[0056] (c) Conductive adhesive layer After forming a recess 9 in the card base 2 for embedding the IC module 70 by cutting with an end mill or the like, the IC module 70 is embedded and fixed in the recess 9, and a conductive adhesive layer 11 for electrical and mechanical connection will be described. As shown in Figure 3(c), the conductive adhesive layer 11 is a liquid or tape-like material that is placed between the first plate 110 and the substrate 72 of the IC module 70 and the terminals 73a formed on the substrate 72.

[0057] The conductive adhesive layer 11 may be applied and attached in advance to the side of the substrate 72 of the IC module 70 opposite to the external connection terminals 71, or it may be applied and attached to the bottom surface of the recess 9 of the card base 2 after cutting.

[0058] A typical conductive adhesive layer 11 may be applied to the entire back surface of the substrate 72 or to the portion corresponding to the first recess 91 of the recesses 9, as it also serves as the mechanical connection between the IC module 70 and the pre-cut card substrate 2. This allows the electrical connection of the IC chip 74a and the antenna 80, and the mechanical connection of the IC module 70 and the card substrate 2, to be made with the same type of conductive adhesive layer 11, contributing to the simplification of the process.

[0059] However, the conductive adhesive layer 11 may be applied and attached to cover only the areas of terminals 73a and 73b on the back surface of the substrate 72, while another adhesive that does not have conductivity may be applied and attached to the rest of the back surface of the substrate 72. Since conductivity does not need to be considered for this other adhesive, it is easier to select an adhesive that is advantageous for mechanical connection.

[0060] As the conductive adhesive layer 11 that can be used for both electrical and mechanical connections, anisotropic conductive film (ACF) or anisotropic conductive paste (ACP) can be used. Alternatively, a conductive paste or solder paste in which silver particles are dispersed as a filler in epoxy resin may also be used. In particular, if ACF is used, the ACF can be heat-laminated over the entire back surface of the substrate 72 of the IC module 70, and after embedding the IC module 70 in the recess 9 of the cut card base 2, it can be heat-pressed at a predetermined temperature and load. This makes it easy to electrically connect the IC chip 74a and the antenna 80. Furthermore, since a mechanical connection of the IC module 70 to the card base 2 can be made at the same time, the mounting process of the IC module 70 to the card base 2 can be simplified.

[0061] When ACF is used as the conductive adhesive layer 11, the electrical connection between the IC chip 74a and the antenna 80, and the mechanical connection between the IC module 70 and the card base 2 can be explained as follows based on Figure 3(c). The conductive adhesive layer 11 has a structure in which conductive particles 11a, in which a metal film is formed around a spherical resin or spherical metal, are dispersed in an adhesive 11b, which is a binder containing adhesive components. The conductive particles may be resin coated with nickel or gold, or solder particles. Various types of solder particles such as SnPb, SnAgCu, SnCu, SnZnBi, SnAgInBi, SnZnAl, etc., or alloys of these with other metals can be used. These configurations are the same when ACP is used.

[0062] Here, thermal pressure is applied to the substrate 72 from the +Z direction to the -Z direction so that the conductive adhesive layer 11, which is positioned between the first plate 110 electrically connected to the tip of the antenna wire 83, the substrate 72 of the IC module 70, and the terminal 73a formed on the substrate 72, is compressed. This ensures both the mechanical connection between the IC module 70 and the card base 2 via the conductive adhesive layer 11, and the electrical connection between the IC chip 74a and the antenna 80.

[0063] (d) Optical switch circuits Next, the optical switch circuit 200 will be explained mainly based on Figures 1(a), 4, and 5. Figures 5(a) and 5(b) are schematic circuit diagrams showing the electrical configuration of the IC card 1 and the optical switch circuit 200.

[0064] The optical switch circuit 200 comprises a roughly rectangular prism housing on which a photoelectric element 210 and electrical terminals 220a and 220b for signal exchange with the outside are exposed on one of its surfaces. Similar to the IC module 70, the optical switch circuit 200 is embedded in a recess 94 formed in the card base 2, and the electrical terminals 220a and 220b of the optical switch circuit 200 are electrically connected to plates 130 and 140, which are the ends of the antenna 80, respectively. Plates 130 and 140 can have a configuration substantially the same as the first plate 110 and second plate 120 described above. Thus, the optical switch circuit 200 forms a switch structure for opening and closing the communication circuit for contactless communication. That is, when the switch element of the optical switch circuit 200 is in a closed state, contactless communication is possible, but when the switch element of the optical switch circuit 200 is in an open state, the communication circuit is disconnected, making contactless communication impossible.

[0065] Similar to the IC module 70, the optical switch circuit 200 is constructed by forming a recess 94 in the card base 2 for embedding the optical switch circuit 200 through cutting with an end mill or the like, and then embedding and fixing the optical switch circuit 200 in the recess 94. At this time, the entire optical switch circuit 200 is mechanically fixed to the recess 94 of the card base 2 by interposing a conductive adhesive layer 13, which has the same configuration as the conductive adhesive layer 11. In addition, the terminals 220a and 220b of the optical switch circuit 200 are electrically connected to the plates 130 and 140, respectively, via the conductive adhesive layer 13. Similar to the conductive adhesive layer 11, the conductive adhesive layer 13 has a configuration in which conductive particles 13a, in which a metal film is formed around a spherical resin or spherical metal, are dispersed in an adhesive 13b, which is a binder containing adhesive components.

[0066] As a result, if terminals 220a and 220b of the optical switch circuit 200 are short-circuited, the antennas 80 connected to plates 130 and 140 will conduct to each other, closing the communication circuit. Plates 130 and 140 may have a laminated configuration including at least two layers, similar to the first plate 110 and second plate 120 described above, consisting of first members 131 and 141 and second members 132 and 142 stacked on the +Z side of the first members 131 and 141.

[0067] The structure of the optical switch circuit 200 is arbitrary, but it comprises at least a photoelectric element 210 and a switch element, with the ends of the antenna 80 electrically connected to both ends of the switch element. Furthermore, at least a portion of the photoelectric element 210 is exposed on the surface of the card base 2 as shown in Figure 4(a), or is embedded in the card base 2 so that it can receive incident light from the outside through a transparent layer such as an oversheet layer as shown in Figure 4(b). As a result, when the IC card 1 is irradiated with a predetermined amount of incident light, the photoelectric element 210 of the optical switch circuit 200 can effectively receive this light, enabling the switching operation of the communication circuit to function smoothly.

[0068] The electrical equivalent circuit of IC card 1, including the arrangement of the optical switch circuit 200, is shown in Figure 5(a). Figure 5(b) shows a schematic circuit diagram of the optical switch circuit 200. IC card 1 can be broadly divided into the IC chip portion, the antenna L outside of it, and the optical switch circuit 200. The IC chip has various circuits that connect to both ends of the antenna L and the rectifier circuit RC, an internal capacitance C connected in parallel to the circuit consisting of the wiring at both ends of the antenna L and the various circuits, and the rectifier circuit RC. The optical switch circuit 200 is connected in series to the circuit consisting of the wiring at both ends of the antenna L and the various circuits.

[0069] The various circuits of the IC chip include a constant voltage circuit and a charging circuit that convert the AC voltage received by antenna L into a DC voltage through a rectifier circuit RC. Furthermore, the various circuits of the IC chip include a demodulation circuit that demodulates the analog signal received by antenna L and converts it into digital data, and a modulation circuit that modulates the digital data into an analog signal and transmits it to an external device through antenna L. It also includes a reset circuit, a clock circuit, digital circuits, and the like.

[0070] On the other hand, the optical switch circuit 200 comprises at least a photoelectric element 210 and a switch element. These two elements do not necessarily have to be physically different; they may be an integrated element that combines both functions. Referring to the circuit in Figure 5(b), a predetermined amount of incident light irradiated from the outside causes the photoelectric element, which includes a solar cell and a photodiode, to generate a predetermined voltage in accordance with the amount of incident light irradiated onto the semiconductor PN junction. The generated voltage is applied to the gate of the switch element, which is composed of a MOSFET or the like, through a control circuit provided inside the photoelectric element. When this applied voltage exceeds a predetermined threshold, the switch element turns on, and the load circuit turns on. As a result, terminals 220a and 220b, which are the connection points between the optical switch circuit 200 and the end of the antenna 80, are short-circuited, and the communication circuit is closed.

[0071] The optical switch circuit 200 described above may be specially designed and manufactured, but it is also effective to use a semiconductor relay that combines a light-emitting element (LED), a photoelectric element, and a switch element (solar cell, control circuit, and MOSFET), which are general-purpose components. Such components are commercialized under names such as PhotoMOS (registered trademark). By removing the light-emitting element from these relay components and incorporating them into the IC card 1 so that the photoelectric element is exposed, it is possible to easily form the optical switch circuit 200 of this embodiment without going through complex design and manufacturing. When the switch element is a MOSFET, the gate voltage is V GS Therefore, V GSIf a MOSFET with a voltage of 10V is used, when the voltage applied to the gate of the switch element becomes 10V or higher, the switch element turns on and the load circuit turns on, and when the voltage applied to the gate falls below 10V, the switch element turns off and the load circuit turns off. In other words, when the voltage generated by the photoelectric element 210 is lower than 10V, the switch element is in an open state where communication is impossible for the communication circuit, and when the voltage generated by the photoelectric element 210 is 10V or higher, the switch element is in a closed state where communication is possible for the communication circuit. GS Standard voltages such as 10V, 5V, 2.7V, and 1.5V are readily available as commercially sold products.

[0072] Furthermore, the photoelectric element 210 that generates voltage according to the amount of incident light is preferably a solar cell rather than a photodiode or phototransistor. This is because solar cells have improved PN junctions to enhance current output due to light irradiation compared to photodiodes and phototransistors, and thus stabilize the switching operation of the optical switch circuit 200 even when there are fluctuations in incident light.

[0073] Furthermore, semiconductor relays that combine a common light-emitting element (LED), a photoelectric element (solar cell), and a switch element (MOSFET) often have the light-emitting element (LED) in the infrared wavelength range. However, from the viewpoint of using the optical switch circuit 200 in this embodiment, it is preferable that the photoelectric element 210 reacts to incident light in the so-called visible light region with a wavelength of 380 nm or more and 780 nm or less. By enabling the opening and closing operation of the optical switch circuit 200 in response to incident light in the visible light region, the communication conditions of the IC card 1 depend only on the intensity of the surrounding visible light, making it easier for the user to predict the opening and closing operation of the optical switch circuit 200 and improving usability.

[0074] On the other hand, the optical switch circuit 200 of the IC card 1 in this embodiment may be configured such that the photoelectric element 210 reacts to the amount of incident light of invisible light such as ultraviolet or infrared light. By enabling the opening and closing operation of the optical switch circuit 200 in response to such incident light in the invisible light region, the communication conditions of the IC card 1 can be made dependent on the use of special devices such as infrared lamps or ultraviolet lamps, resulting in a usage pattern that differs from the usual predictions. As a result, although the predictability of the user's opening and closing operation of the optical switch circuit 200 is reduced, this predictability from the perspective of a third party is also reduced, thus improving security. The wavelength range of invisible light can be, for example, a range with wavelengths shorter than 380 nm or a range with wavelengths longer than 780 nm.

[0075] (e) Method of manufacturing an IC card Next, an example of a method for manufacturing an IC card 1 using the card base 2, IC module 70, optical switch circuit 200, and conductive adhesive layers 11 and 13 described above will be explained.

[0076] First, the first plate 110 and the second plate 120, which are plate-shaped ends 100, are bonded to the surface of either the antenna holding layer 5 or 6 on the side not adjacent to the inner layer 4 or 7, and the plates 130 and 140, which are also plate-shaped ends, are bonded to it.

[0077] Next, the insulated conductor covered with an insulating material is used as the antenna wire 83, and is embedded by a winding machine into the forming surface of the antenna holding layer 5 or 6 where the end 100 is formed, starting from either the first plate 110 or the second plate 120 and ending at the other. At the start and end points of the antenna wire 83, the winding machine welds the ends of the antenna wire 83 to the first plate 110 and the second plate 120. However, the antenna wire 83 is cut at the point where it is welded to either the plate 130 or 140, and then resumes from where it was welded to the other plate, and is embedded to the end.

[0078] Specifically, for example, while applying a predetermined heat and pressure to the antenna holding layer 6, the antenna supply head is drawn in a loop shape as shown in Figure 1(a), and the antenna wires 83 supplied from the antenna supply head are sequentially embedded in the antenna holding layer 6. At this time, the antenna holding layer 6 may also be referred to as the first substrate.

[0079] Next, as shown in Figure 1(b), the oversheet layer 8, inner layer 7, antenna holding layers 6 and 5, inner layer 4, and oversheet layer 3 are stacked in this order from the bottom in the thickness direction. Then, the laminate of large sheets in which the cards are arranged in multiple directions is sandwiched between stainless steel plates from above and below in the thickness direction, and heat and pressure are applied to the laminate through the stainless steel plates. At this time, the antenna 80 is formed in advance on the surface of, for example, the antenna holding layer 6 so as to be sandwiched between the antenna holding layers 5 and 6. At this time, the antenna holding layer 5, which is positioned opposite the antenna holding layer 6, which is the first base material, and is laminated to the first base material so as to sandwich the antenna 80, may be referred to as the second base material.

[0080] By going through this hot pressing process, a large-format sheet-type card base can be obtained in which each layer of the laminate, including the first and second substrates, is integrated. Furthermore, if any of the oversheet layer, inner layer, or antenna holding layer has heat resistance that prevents heat fusion at a predetermined temperature, an adhesive sheet that heats together at a predetermined temperature is sandwiched between each layer, or an adhesive is applied. Then, by subjecting these to a hot pressing process, an integrated large-format sheet-type card base can be obtained.

[0081] The large sheet of card base material obtained as described above, in which cards are arranged in multiple rows vertically and horizontally, is punched out using a die-cutting machine to form card base material 2 that conforms to the ISO / IEC 7816 card size. Furthermore, recesses 9 for embedding the IC module 70 and recesses 94 for embedding the optical switch circuit 200 are formed in the card base material 2 by cutting with an end mill. This yields the cut card base material 2. As previously mentioned, the recess 9 consists of two stages: a first recess 91 with a first depth for housing the flat substrate 72 of the IC module 70, and a second recess 92 with a second depth deeper than the first recess 91 for housing the convex IC chip body 74. The bottom surface of the first recess 91 of the card base material 2 exposes the surfaces of the first plate 110 and the second plate 120. On the other hand, the bottom surface of the recess 94 of the card base material 2 exposes the surfaces of plates 130 and 140.

[0082] On the other hand, separate from the manufacturing of the card base 2 and the cutting process to form the recess 9, conductive adhesive layers 11 and 13 are attached to the IC module 70 and optical switch circuit 200. Typically, module tape is used for the IC module 70 and optical switch circuit 200, in which these components are formed continuously on a long tape in one or two rows. Tape-shaped ACF is attached to the side of this module tape opposite to the side where the external connection terminals 71 are formed, while applying a certain amount of heat and pressure. Then, the module tape with the ACF attached is punched out in a punching machine as a roughly rectangular IC module 70 or optical switch circuit 200 with rounded corners, thereby obtaining the IC module 70 or optical switch circuit 200 with the conductive adhesive layers 11 and 13 attached.

[0083] Subsequently, the IC module 70 and optical switch circuit 200, to which conductive adhesive layers 11 and 13 are attached, are embedded in the card base 2, which has recesses 9 and 94 formed therein. Then, a predetermined heat block is pressed against the external connection terminals 71 and photoelectric element 210, and predetermined heat and pressure are applied toward the card base 2 for a predetermined time. This melts the conductive adhesive layers 11 and 13, which are made of ACF, thereby establishing electrical connections between the terminals 73a, 73b and 220a and 220b of the IC module 70 and optical switch circuit 200 and the first plate 110, the second plate 120 and plates 130 and 140. At the same time, mechanical connections are established between the IC module 70 and optical switch circuit 200 and the card base 2. While the application time and heat / pressure conditions for ACF vary depending on its type and composition, as an example, the application time can be between 0.5 seconds and 10.0 seconds, the temperature between 150°C and 250°C, and the pressure between 20 MPa and 100 MPa.

[0084] (f) Regarding the IC card of the first embodiment In summary, the IC card 1 of the first embodiment is a dual-interface IC card capable of contactless communication with external devices. The IC card 1 comprises a card base 2, an IC chip 74a disposed inside the card base 2, and an antenna 80 electrically connected to the IC chip 74a. Furthermore, the IC card 1 includes an optical switch circuit 200 arranged in series with the communication circuit formed by the IC chip 74a and the antenna 80, which can select whether or not to close the communication circuit. The optical switch circuit 200 includes a photoelectric element 210 that converts a predetermined incident light into a voltage corresponding to the level of the incident light. The optical switch circuit 200 also includes a switch element that sets the communication circuit to an open state, making communication impossible, when the voltage generated by the photoelectric element 210 is lower than a predetermined value, and to a closed state, making communication possible, when the voltage generated by the photoelectric element 210 is equal to or greater than a predetermined value.

[0085] In the IC card 1 of the first embodiment, if the amount of predetermined incident light irradiating the photoelectric element 210 of the optical switch circuit 200 is insufficient, for example, if the IC card 1 is sealed in an envelope and being sent to the user, or if the user has the IC card 1 in their wallet, the IC card 1 will not perform contactless communication. On the other hand, if the user takes the IC card out of their wallet in a store or the like, and the photoelectric element 210 is sufficiently irradiated with the predetermined incident light, the IC card 1 will perform contactless communication normally. Therefore, in this embodiment, it is possible to provide an IC card that allows for easy selection of usage by the user, has excellent durability, and can suppress skimming.

[0086] In this embodiment, IC card 1 was described as a dual-interface IC card. However, this disclosure is not limited to this, and it goes without saying that it is also applicable to contactless IC cards in which the IC module does not have external connection terminals and is completely embedded inside the card base. In this case as well, the effect obtained by suitably controlling the on / off state of the communication circuit formed by the IC chip and antenna in response to predetermined incident light is the same. This point is also true for other embodiments and modifications described later.

[0087] 2. Modified form of the first embodiment (a) Variation 1 A modified version of the IC card 1 of the first embodiment will now be described. In the IC card 1 of the first embodiment, the photoelectric element 210 of the optical switch circuit 200 is exposed on one side. However, before the user starts using the card and when it is not in use, an adhesive light-shielding label 300 that covers the entire photoelectric element 210 may be attached to the side of the IC card 1 where the photoelectric element 210 is exposed, as shown by the dashed line in Figure 4(a). The material of the light-shielding label 300 is not limited as long as it has adequate light-shielding properties, but it is preferable to use a label that is removable and re-adhesive, or a label that is removable and non-re-adhesive.

[0088] If the light-blocking label 300 is configured as described above, the user can repeatedly attach and detach the light-blocking label 300 to cover the entire photoelectric element 210 as needed. This improves the user's convenience in distinguishing between use and non-use. If the light-blocking label 300 is configured as described above, after the user has removed the light-blocking label 300, it cannot be reattached to cover the entire photoelectric element 210, effectively preventing use only when the element is unused until the user's first use.

[0089] In this way, by attaching a light-shielding label 300 that covers the entire photoelectric element 210 to the IC card 1 when not in use, the risk of unnecessary skimming during mailing or when not intended for use can be further reduced. Conversely, by attaching a transparent label with lens function that covers the entire photoelectric element 210, the incident light is focused by the transparent label, increasing the amount of light incident on the photoelectric element 210. As a result, the sensitivity of the photoelectric element 210 to incident light is improved, and the opening and closing operation of the optical switch circuit 200 can be selected more clearly.

[0090] (b) Variation 2 Another modification of the IC card 1 of the first embodiment will now be described. As partially mentioned in the description of the first embodiment, the photoelectric element 210 of the optical switch circuit 200 may not be directly exposed on one side of the IC card 1, and the optical switch circuit 200 may be arranged on the card base 2 so that it can receive incident light from the outside through a transparent layer. A cross-sectional view of this example IC card 1a, corresponding to Figure 4(a), is shown in Figure 4(b).

[0091] The optical switch circuit 200 is positioned on the card base 2 such that it can receive incident light from the outside via a transparent layer, i.e., an oversheet layer 3, that covers the entire photoelectric element 210 on the side of the IC card 1a where the optical switch circuit 200 is located. Here, transparency means that there should be enough light transmittance to allow a predetermined amount of incident light, which is visible light from the outside, to reach the photoelectric element 210 and cause the switch element to open and close. Specifically, for example, the transmittance for visible light in the wavelength range of 380 nm to 780 nm in the vertical direction is preferably 50% or more, more preferably 70% or more, and even more preferably 90% or more. The higher the transmittance, the better the responsiveness of the switch element to the level of incident light.

[0092] In this method of manufacturing IC card 1a, for example, cutouts for housing the optical switch circuit 200 are made in the antenna holding layer 5 and inner layer 4 before each layer is laminated. Then, when the layers from the oversheet layer 8 to the inner layer 4 are laminated, the optical switch circuit 200 is housed within the laminate, and the oversheet layer 3 is placed on top of it and the entire assembly is heat-pressed. This results in an IC card 1a in which the optical switch circuit 200 is embedded and covered by the oversheet layer 3.

[0093] 3. Second Embodiment Next, the IC card 1b of the second embodiment of this disclosure will be described. Figure 6 is a plan view of the IC card 1b as seen from the +Z direction, corresponding to Figure 1(a). The IC card 1b of the second embodiment differs from the IC card 1 of the first embodiment in that, in addition to the optical switch circuit 200, an optical switch circuit 200a with a similar configuration is further provided in series with the contactless communication circuit consisting of the antenna 80 and the IC chip 74a.

[0094] In other words, the IC card 1b of the second embodiment consists of an optical switch circuit, which is a first optical switch circuit 200, and an optical switch circuit, which is a second optical switch circuit, which is an optical switch circuit, arranged in series with the communication circuit. Here, the communication circuit becomes capable of communication when both the first switch element, which is a switch element of the first optical switch circuit, and the second switch element, which is a switch element of the second optical switch circuit, are in a closed state. Conversely, as long as either the first optical switch circuit or the second optical switch circuit is in a closed state but the other is in an open state, the communication circuit becomes incapable of communication.

[0095] As shown in Figure 4(a), terminals 220a and 220b for electrical connection are provided at the lower end of the optical switch circuit 200. Conductive plates 130 and 140, welded to the end of the antenna wire 83, are positioned opposite these terminals 220a and 220b in the Z-axis direction, with a portion of them exposed on the bottom surface of the recess 94. A conductive adhesive layer 13 is interposed between terminal 220a and plate 130, and between terminal 220b and plate 140, ensuring conductivity between terminal 220a and plate 130, and between terminal 220b and plate 140. As a result, when the switch element of the optical switch circuit 200 is in a closed state, terminals 220a and 220b are short-circuited, and when the switch element of the optical switch circuit 200 is in an open state, terminals 220a and 220b are insulated.

[0096] On the other hand, terminals 220c and 220d for electrical connection are similarly provided on the lower end of the optical switch circuit 200a. Although not specifically shown as it is the same as in Figure 4(a), conductive plates 150 and 160, welded to the tip of the antenna wire 83, are positioned opposite these terminals 220c and 220d in the Z-axis direction, with a portion of them exposed on the bottom surface of the recess. A conductive adhesive layer 13 is interposed between terminal 220c and plate 150, and between terminal 220d and plate 160, ensuring conductivity between terminal 220c and plate 150, and between terminal 220d and plate 160. As a result, when the switch element of the optical switch circuit 200a is in the closed state, terminals 220c and 220d are short-circuited, and when the switch element of the optical switch circuit 200a is in the open state, terminals 220c and 220d are insulated.

[0097] The optical switch circuit 200 is positioned on the +Z side surface of the IC card 1a where the external connection terminal 71 is located, such that the photoelectric element 210 is exposed slightly to the lower right of the center, i.e., closer to the +X and -Y directions than the center. On the other hand, the optical switch circuit 200a is positioned on the same surface as the optical switch circuit 200, such that the photoelectric element 210a is exposed slightly to the lower left of the center, i.e., closer to the -X and -Y directions than the center. However, the arrangement of the optical switch circuits 200 and 200a is not limited to these positions, and they may be positioned at any position on the +Z side surface where the external connection terminal 71 is located.

[0098] In this way, by providing two optical switch circuits, the likelihood of contactless communication becoming impossible even when incident light is locally irradiated onto the IC card 1a is increased, while the likelihood of contactless communication becoming possible under conditions where the entire area around the IC card 1a is uniformly lit is increased. In other words, operational instability such as frequent switching of communication capability in response to temporary changes in incident light can be suppressed, and stable operation can be expected. Furthermore, ensuring operational stability is made easier by positioning the two optical switch circuits far apart from each other. Specifically, it is preferable that the two optical switch circuits be positioned on one side and the other side of a straight line along the Y-axis that equally divides the area of ​​the IC card 1a into left and right halves, along the long side of the IC card 1a.

[0099] Furthermore, it is preferable that the two optical switch circuits be positioned along the short side of the IC card 1a, on one side above and the other side above a straight line along the X-axis that divides the area of ​​the IC card 1a equally vertically. Moreover, it is preferable that the two optical switch circuits be positioned along the short and long sides of the IC card 1a, on the other side of each of the four divided quadrants with respect to straight lines along the X-axis and Y-axis that divide the area of ​​the IC card 1a equally vertically and horizontally. In this embodiment, the arrangement of two optical switch circuits is illustrated, but this disclosure is not limited to this, and three or more optical switch circuits may be arranged in series with respect to the communication circuit.

[0100] 4. Third Embodiment Next, the IC card 1c of the third embodiment of this disclosure will be described. Figure 7(a) is a plan view of the IC card 1c viewed from the +Z direction, corresponding to Figure 1(a). Figure 7(b) is a similar plan view of the IC card 1c viewed from the opposite direction, the -Z direction. The IC card 1c of the third embodiment is similar to the IC card 1b of the second embodiment in that, in addition to the optical switch circuit 200, an optical switch circuit 200a with a similar configuration is further provided in series with the contactless communication circuit consisting of the antenna 80 and the IC chip 74a. However, it differs from the IC card 1b of the second embodiment in that the photoelectric element 210a of the optical switch circuit 200a is exposed on the side of the IC card 1c opposite to the photoelectric element 210 of the optical switch circuit 200.

[0101] In other words, in the IC card 1b of the third embodiment, the first photoelectric element, which is the photoelectric element 210 of the optical switch circuit 200, which is the first optical switch circuit, and the second photoelectric element, which is the photoelectric element 210a of the optical switch circuit 200a, which is the second optical switch circuit, are arranged differently. That is, the two are arranged on the card substrate 2 such that at least a portion of them is exposed to the surface of the card substrate 2 on opposite surfaces of the card substrate 2, or so that they can receive incident light from the outside through a transparent layer.

[0102] Regarding the arrangement of the optical switch circuits 200 and 200a, as in the second embodiment, it is preferable that their positions be somewhat separated when viewed from above, and the reason for this is the same as explained in the second embodiment.

[0103] In this embodiment, two optical switch circuits are provided on the front and back surfaces of the IC card 1c such that their photoelectric elements are exposed on opposite sides, or that the photoelectric elements can receive light through a transparent layer. This increases the likelihood that contactless communication will become impossible even if incident light is locally shone on one side of the IC card 1c. Furthermore, it increases the likelihood that contactless communication will be possible under conditions where the entire area surrounding the IC card 1c, including both sides, is uniformly lit. In other words, operational instability such as frequent switching of communication capability in response to temporary changes in incident light can be further suppressed, and more stable operation can be expected. In addition, by positioning the two optical switch circuits far apart from each other, including their relationship to the front and back surfaces, ensuring operational stability becomes even easier.

[0104] Furthermore, the embodiments and modifications described herein also include combinations of these embodiments to the extent that they do not contradict each other. For example, the embodiment of attaching a light-shielding label to cover the photoelectric element is also applicable to the second and third embodiments. Similarly, the same applies to arranging the photoelectric element on the card substrate so that it can receive incident light from the outside through a transparent layer, rather than directly exposing it on the card surface. [Explanation of Symbols]

[0105] 1, 1a, 1b, 1c IC cards 2 card bases 3.8 Oversheet layer 4, 7 Inner layer 5, 6 Antenna holding layer 9 recesses 11, 13 Conductive adhesive layer 11a, 13a conductive particles 11b, 13b Adhesives 12 Antenna Sheets 70 IC modules 71 External connection terminals 72 circuit boards 73a, 73b terminal 74 IC chip units 74a IC chip 74b Molding section 74p pad 75 wires 76 Bonding Holes 80 Antenna 83 Antenna wire 91 First recess 92 Second recess 93 Outer circumference 93a, 93b sides 100 end 110 Plate 1 111 First Member 112 Second Member 120 Second Plate 130, 140, 150, 160 plates 131 First Member 132 Second Member 200, 200a Optical Switch Circuit 210, 210a Photoelectric element 220a, 220b, 220c, 220d terminals 300 Light-blocking labels

Claims

1. An IC card that enables contactless communication with external devices, Card base and, An IC chip disposed inside the card base and an antenna electrically connected to the IC chip, The system includes an optical switch circuit arranged in series with the communication circuit formed by the IC chip and the antenna, which can select whether or not to close the communication circuit. The optical switch circuit comprises a photoelectric element that converts a predetermined incident light into a voltage corresponding to the level of the incident light, The system includes a switch element that, when the voltage generated by the photoelectric element is lower than a predetermined value, puts the communication circuit into an open state where communication is impossible, and when the voltage generated by the photoelectric element is equal to or greater than a predetermined value, puts the communication circuit into a closed state where communication is possible. An IC card in which the photoelectric element is arranged on the card substrate such that at least a portion of it is exposed on the surface of the card substrate, or so that it can receive incident light from the outside through a transparent layer.

2. The IC card according to claim 1, wherein the photoelectric element comprises a solar cell and the switch element comprises a MOSFET.

3. The IC card according to claim 1, which is a dual-interface IC card.

4. The IC card according to claim 1, wherein when not in use or unused, a light-shielding label is affixed to the surface of the card base so as to cover the photoelectric element.

5. The optical switch circuit is composed of a first optical switch circuit and a second optical switch circuit arranged in series with respect to the communication circuit. The IC card according to any one of claims 1 to 4, wherein the communication circuit becomes capable of communication when both the first switch element, which is the switch element of the first optical switch circuit, and the second switch element, which is the switch element of the second optical switch circuit, are in a closed state.

6. The IC card according to claim 5, wherein the first photoelectric element, which is a photoelectric element of the first optical switch circuit, and the second photoelectric element, which is a photoelectric element of the second optical switch circuit, are arranged on the card substrate such that at least a portion of each is exposed to the surface of the card substrate, or so that incident light from the outside can be received through a transparent layer, with respect to opposite surfaces of the card substrate.

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