JP2007280426A - Ic module, ic label, and ic card - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an IC label for preventing reduction in a service area even when it is stuck to a commodity and the like in comparison with that in single use. <P>SOLUTION: This IC label has an IC module 31, an adhesive layer 7 laminated on the IC module 31, a skin layer 4 laminated on the adhesive layer 7, a tacky layer 5 laminated on the reverse side of a circuit board 1, and a peeling layer 6 laminated on the reverse surface of the tacky layer 5. The IC module has a circuit base material 1, an IC chip 3 which is arranged on the circuit base material 1 and has a capacitor inside, and an antenna coil 2 electrically connected to the IC chip 3 on the circuit base material 1. A resonance frequency f0 of an LC resonance circuit composed of the capacitor and the antenna coil 2 to a free space is set to shift to a higher frequency side than an oscillation frequency fosc of an external information recording and reproducing device. The decrease in a resonance frequency fop, which is caused when the IC label is stuck, is canceled by setting the resonance frequency f0 to be higher than the oscillation frequency fosc. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an information recording medium for exchanging information in a non-contact manner, and more particularly to a non-contact type IC label, an IC card, and an IC module used therefor.

  In recent years, an information recording medium has been devised in which an IC chip is incorporated and information is exchanged via an external information recording / reproducing apparatus (hereinafter referred to as “reader / writer”). This information recording medium is called an IC label, IC card, IC tag or the like (hereinafter referred to as “IC label or the like”) depending on its shape. In a non-contact type IC label or the like, a current flows in a resonance circuit built in the IC label or the like due to an electromagnetic wave emitted from a reader / writer, and information is written to or read from the IC chip. By using electromagnetic waves, the reader / writer and the IC label can exchange information without bringing them into contact with each other. Therefore, simple information exchange is possible without making the information recording medium come into contact with the reading device like a barcode, and there is no inconvenience such as failure in reading information due to poor contact. Further, an IC label or the like has an advantage that a power source is not required for the IC label or the like because a current flows due to an electromagnetic wave emitted from a reader / writer. Furthermore, since the IC chip can easily update information and has a large capacity, it can record a larger amount of information than a magnetic tape or the like. Further, since the information written on the IC chip cannot be confirmed by visual observation or the like, the contents of the information can be hidden unless a dedicated reader / writer is used. Further, since the IC chip and the resonance circuit can be reduced in size, the IC label or the like can be made thin and light. It has been proposed to use this medium as, for example, an ID card, a membership card, a commuter pass, a pass ticket event numbered ticket, a delivery tag, an identification tag, or the like. In addition, by attaching an IC label to a book, inventory management can be easily performed in, for example, a bookstore or a library. In the future, an information recording medium containing an IC chip will be affixed to the product and used together with electronic money, so that the buyer can simply pass the product through the gate containing the reader / writer. A system for performing settlement has been proposed.

  In order to increase the value of current flowing in the mounted resonance circuit, the non-contact type IC label or the like conventionally has a resonance frequency of a resonance circuit built in a single IC label or the like and an oscillation frequency of an electromagnetic wave emitted from a reader / writer. And was designed to match. However, it is assumed that the IC label is originally used in a state where it is affixed to a book, a product arranged in a store, or the like, not a single state. Further, it is assumed that the IC card is usually used in a state of being stored in a wallet or in an inner pocket of clothes. In such a usage mode, the communicable distance between the IC label and the reader / writer is shorter than that in the case of the IC label alone. This is because when an IC label is affixed to a product or the like, the product or the like functions as a dielectric, so that the resonance frequency fop during operation of the circuit included in the IC label deviates from the resonance frequency f0 when the IC label alone is used. Because it ends up. When the IC card is stored in a wallet or the like, the wallet or the like functions as a dielectric, so that the resonance frequency fop during operation shifts. In order to eliminate the disadvantage that the resonance frequency fop during operation shifts, if the IC label is peeled off from the product or the IC card is taken out and information is exchanged with the reader / writer, the advantages of the IC label etc. are fully utilized. I can't.

  Also, when a product or the like with an IC label is laminated, since there are a plurality of IC labels, they are electrically coupled to each other, and together with the presence of the dielectric, the resonance frequency fop during operation of the IC label. Has a disadvantage that it is greatly deviated from that of the IC label alone. Also in this case, the communicable distance is very short as compared with the IC label alone.

  IC labels and the like are disclosed in Japanese Patent Application Laid-Open No. 6-243358 (hereinafter referred to as “prior art 1”) and Japanese Patent Application Laid-Open No. 11-134460 (hereinafter referred to as “prior art 2”). However, although the prior art 1 discloses the basic structure of the ID tag, there is no recognition of the problem of a decrease in the maximum communicable distance in actual use. Although the prior art 2 discloses a general-purpose IC label, the basic IC label structure is the same as that described in the prior art 1, and there is no mention of setting the resonance frequency. On the contrary, when the IC label is affixed to a product or when the product is laminated, there is no examination of how much the resonance frequency fop at the time of operation of the resonance circuit included in the IC label specifically changes. is the current situation.

  The present invention has been made to solve such problems of the prior art, and an object thereof is to provide an IC module in which the maximum communicable distance does not decrease despite the presence of a dielectric. .

  Another object of the present invention is to provide an IC label that does not reduce the maximum communicable distance even if it is attached to an object.

  Still another object of the present invention is to provide an IC label that does not reduce the distance at which a plurality of IC labels attached to a plurality of objects can be identified and information can be exchanged.

  Still another object of the present invention is to provide an IC card in which the maximum communicable distance does not decrease even when stored in a dielectric.

  In order to achieve the above object, a first feature of the present invention includes a circuit base, a semiconductor memory disposed on the circuit base, and a resonant circuit electrically connected to the semiconductor memory on the circuit base. And the resonance frequency of the resonance circuit with respect to the free space is an IC module set so as to be shifted to a higher frequency side than the oscillation frequency of the external information recording / reproducing apparatus for recording and reproducing information in the semiconductor memory. is there. Here, as the “resonance circuit”, an LC resonance circuit including a capacitor and an inductor (coil) can be used. The capacitor may be built in the same IC chip as the semiconductor memory, or may be mounted as a circuit element outside the IC chip. The “free space” is a space where the relative dielectric constant εr satisfies εr = 1, and specifically refers to a space where no dielectric exists in the region, that is, a vacuum. An “external information recording / reproducing device” is a device that reads out the contents of information recorded in a semiconductor memory, an IC chip or the like or writes new information by oscillating electromagnetic waves to the IC module.

  In the first feature of the present invention, by setting the resonance frequency for the free space of the resonance circuit included in the single IC module to be shifted to the higher frequency side than the oscillation frequency of the external information recording / reproducing apparatus, The resonance frequency shift due to the influence of the dielectric existing around can be effectively eliminated. Since the resonant frequency during operation shifts in the direction of decreasing the frequency due to the presence of the dielectric, setting the resonant frequency for the free space of the resonant circuit of the IC module in advance increases the resonant frequency in the surroundings to operate. Even if the resonance frequency at that time decreases, the difference from the oscillation frequency of the external information recording / reproducing apparatus can be kept low.

  A second feature of the present invention includes a circuit substrate, an IC chip containing a capacitor disposed on the circuit substrate, and an antenna coil electrically connected to the IC chip on the circuit substrate. An IC module in which the resonance frequency with respect to the free space of the LC resonance circuit composed of the capacitor and the antenna coil is set to be higher than the oscillation frequency of the external information recording / reproducing apparatus that records and reproduces information on the IC chip. It is a point.

  In the second feature of the present invention, similarly to the first feature of the present invention, even when an IC module is used, even if a dielectric is present in the vicinity and the resonance frequency during operation is lowered, the oscillation frequency of the external information recording / reproducing apparatus It is possible to keep the difference between and low. Further, by using an IC chip with a built-in capacitor, it is not necessary to place a capacitor on a circuit substrate separately from the semiconductor memory, and the IC module can be downsized. Further, since the capacitor is built in the IC chip, the number of parts to be connected by bonding or the like can be reduced, so that the risk of disconnection or the like can be reduced.

  The third feature of the present invention is the IC module according to the second feature of the present invention, the adhesive layer laminated on the IC module, the skin layer laminated on the adhesive layer, and the IC module. The gist of the invention is an IC label comprising an adhesive layer laminated on the lower surface of the circuit substrate and a release layer laminated on the lower surface of the adhesive layer.

  In general, since it is assumed that an IC label is used by being attached to an object, an influence of a dielectric on a resonance circuit included in the IC label inevitably occurs. Therefore, it is effective to set a single resonance frequency higher than the oscillation frequency of the external information recording / reproducing apparatus in advance as in the IC label according to the third feature of the present invention. Even if the resonance frequency during the operation of the circuit included in the IC label is lowered due to the influence of the dielectric, the resonance frequency of the IC label alone is set to a high value in advance. The difference can be kept low. Therefore, the IC label according to the third feature of the present invention can maintain the communication distance of the IC label attached to the dielectric at a level comparable to that of a single IC label. Further, in many cases, dielectrics with IC labels are exchanged with an external information recording / reproducing apparatus in combination with a plurality of dielectrics. In this case, the resonance frequency of the IC label during operation is further smaller than the resonance frequency of the IC label alone. Therefore, it is effective to set the resonance frequency of the single IC label higher than the oscillation frequency of the electromagnetic wave emitted by the external information recording / reproducing apparatus.

  It is desirable that the resonance frequency of the resonance circuit included in the IC label with respect to the free space is shifted to the high frequency side by a frequency shift amount in the range of 2% to 12% of the oscillation frequency. This is because if the resonance frequency for the free space of the resonance circuit included in the IC label is increased within this range, the resonance frequency shift during operation due to the influence of the dielectric can be eliminated more effectively.

  According to a fourth aspect of the present invention, there is provided an IC module according to the second aspect of the present invention, a first adhesive sheet laminated on the IC module, and a first oversheet laminated on the first adhesive sheet. And a second adhesive sheet laminated on the lower surface of the circuit substrate constituting the IC module, and a second oversheet laminated on the lower surface of the second adhesive sheet. Is the gist.

  IC cards are usually used in a state where they are stored in something. Therefore, there is a dielectric around the IC card, and as in the case of the first, second and third features of the present invention, resonance occurs when the IC card is actually used compared to the case of a single unit. The resonant frequency during the operation of the circuit is lowered. Therefore, by setting the resonance frequency of the resonance circuit included in the IC card high in advance as in the fourth feature of the present invention, the decrease in the communicable distance is suppressed.

  It is desirable that the resonance frequency of the resonance circuit included in the IC card with respect to the free space is shifted to the high frequency side by a frequency shift amount in the range of 2% to 12% of the oscillation frequency. This is because if the resonance frequency for the free space of the resonance circuit included in the IC card is increased within this range, the resonance frequency shift during operation due to the influence of the dielectric can be eliminated more effectively.

  As described above, according to the present invention, it is possible to provide an IC module in which the maximum communicable distance does not decrease despite the presence of a dielectric.

  Further, according to the present invention, it is possible to provide an IC label in which the maximum communicable distance does not decrease even if it is attached to an object.

  Furthermore, according to the present invention, it is possible to provide an IC label that does not reduce the distance at which a plurality of IC labels attached to a plurality of objects can be identified and information can be exchanged.

  Furthermore, according to the present invention, it is possible to provide an IC card in which the maximum communicable distance does not decrease even when stored in a dielectric.

  Embodiments of the present invention will be described below with reference to the drawings. In the description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic, and the relationship between the thickness and width of the layers, the ratio of the thicknesses of the layers, and the like are different from the actual ones. In addition, it goes without saying that portions with different dimensional relationships and ratios are also included in the drawings.

(First embodiment)
As shown in FIG. 1, the IC label according to the first embodiment of the present invention includes an IC module 31, an adhesive layer 7 laminated on the IC module 31, a skin layer 4 laminated on the adhesive layer 7, The adhesive layer 5 laminated | stacked on the lower surface of the circuit base material 1 and the peeling layer 6 laminated | stacked on the lower surface of the adhesive layer 5 are provided. Here, the IC module 31 is electrically connected to the IC chip 3 on the circuit substrate 1, the IC chip 3 fixed on the circuit substrate 1 with the anisotropic conductive adhesive 8, and the circuit substrate 1. The antenna coil 2 is provided.

  The IC chip 3 includes a semiconductor memory and a capacitor, and the capacitor and the antenna coil 2 constitute a resonance circuit. The resonance frequency f0 of the resonance circuit in free space is given by the following equation using the inductance L0 of the coil in free space and the capacitance C of the capacitor.

f0 = 1 / (2π * (L0 * C) ^1/2 ) (1)
Since the IC label has a resonance circuit, an induced electromotive force is generated in the antenna coil 2 by the electromagnetic wave sent from the reader / writer, and a current flows through the resonance circuit. With this current, information can be written to and read from the semiconductor memory in the IC chip 3.

  Here, in order to have a high sensitivity as an IC label for calculation, it is necessary to efficiently pass a current through the resonance circuit. Therefore, the oscillation frequency fosc of the electromagnetic wave emitted by the reader / writer and the operation of the circuit in the IC label It is necessary to match the resonance frequency fop.

fosc = fop (2)
In order to maintain good sensitivity of the IC label even when it does not completely match, the deviation of the resonance frequency fop during the operation of the IC label from the oscillation frequency fosc of the reader / writer:
Δf = fop−fosc (3)
Is required to be kept within Δf = ± 300 kHz. By changing the inductance L0 of the antenna coil 2 or the capacitance C of the capacitor built in the IC chip 3 from the equation (1), the resonance frequency f0 in the free space of the IC label can be changed. In order to maintain good sensitivity, the conventional method is to match the oscillation frequency fosc of the reader / writer, that is,
f0 = fosc (4)
The shape of the antenna coil and capacitor was designed so that However, when an IC label is actually affixed to a book, the affixed book functions as a dielectric, so that the inductance Lop of the antenna coil 2 during operation changes from the value L0 for free space. In other words, the resonance frequency fop during operation is
fop = 1 / (2π * (Lop * C) ^1/2 ) (5)
Given in. Therefore, the resonance frequency fop at the time of the operation of the IC label changes from the equation (5), and takes a value different from the oscillation frequency fosc of the reader / writer. Therefore, the sensitivity of the IC label is lowered, and the communicable distance between the IC label attached to the book and the reader / writer is also shorter than that of the IC label alone.

  The curve in FIG. 7 is a graph obtained by measuring how much the resonance frequency fop at the time of operation of the IC label changes when the IC label is attached to the book using a network analyzer (RX mode). According to FIG. 7, the resonance frequency f0 of the IC label alone is about 13.6 MHz, whereas the resonance frequency fop of the IC label decreases to about 12.9 MHz when the thickness of the book to which the IC label is attached exceeds 20 mm. I understand that. On the other hand, in order to maintain good sensitivity of the IC label, as described above, it is necessary to suppress the deviation Δf of the resonance frequency fop during the operation of the IC label with respect to the oscillation frequency fosc of the reader / writer within ± 300 kHz. On the other hand, the resonance frequency deviation Δf when an IC label is attached to a book having a thickness of 20 mm or more is about 700 kHz as compared with the resonance frequency f0 of the IC label alone from the graph of FIG. Therefore, even if the IC label is manufactured by matching the resonance frequency f0 in the free space of the circuit included in the IC label with the oscillation frequency fosc of the reader / writer at the design stage, the IC label is markedly attached to the book. It can be seen that the sensitivity is lowered and the communicable distance is shortened.

  Therefore, in the IC label according to the first embodiment, the antenna is set so that the resonance frequency f0 in the free space of the circuit included in the single IC label in advance is 2% to 8% higher than the oscillation frequency fosc of the reader / writer. The coil cross-sectional area and number of turns are designed. When the resonance frequency f0 in the free space of a single IC label is shifted in advance and actually attached to a book, the book functions as a dielectric, reducing the resonance frequency fop of the IC label during operation. Even in this case, the resonance frequency can be kept within the required range Δf. The oscillation frequency fosc of the reader / writer is usually several MHz to several tens of MHz. Therefore, when the IC label according to the first embodiment is attached to a book by using a resonance frequency f0 for the free space of the circuit 2% to 8% higher than the oscillation frequency fosc of the reader / writer, The difference Δf between the resonance frequency fop at the time and the oscillation frequency fosc of the reader / writer can be suppressed to within ± 300 kHz. As described above, when the IC label according to the first embodiment is attached to a book and used, it is possible to suppress a decrease in the maximum communicable distance.

  Further, according to the graph of FIG. 7, it can be seen that the resonance frequency deviation Δf hardly changes for a book having a thickness of 20 mm or more. Therefore, if the resonance frequency f0 for the free space of the circuit included in the IC label is increased by 2 to 8% higher than the oscillation frequency fosc of the reader / writer, the maximum communicable distance is reduced for books of all thicknesses of 20 mm or more. It can be seen that it can be suppressed. Since the thickness of a normal book is 20 mm or more, the IC label according to the first embodiment can be used for almost any kind of book. Therefore, the IC label according to the first embodiment also has an advantage of high versatility.

  Furthermore, although the first embodiment is described mainly from the point of suppressing the decrease in the communicable distance, the resonance frequency f0 with respect to the free space of the circuit included in the IC label is set to 2 to less than the oscillation frequency fosc of the reader / writer. Decreasing the sensitivity of the IC label can be suppressed by increasing it by 8%. Therefore, when the IC label is attached to the book, there is an advantage that reading or writing can be performed with good sensitivity without increasing the output of the reader / writer as compared with the case of the IC label alone.

  The circuit substrate 1 is made of a thin plastic plate. By being made of a thin plastic plate, the IC label according to the first embodiment can be easily bent, and is applied not only on a flat surface such as a book cover but also on a curved surface such as a side surface of a bottle. be able to. Specifically, a polyethylene terephthalate film is used as the material of the circuit substrate 1. If the thickness of the circuit base material 1 is reduced to 30 μm or less, the strength of the circuit base material 1 becomes low and it becomes difficult to hold the IC chip on the circuit base material 1, which is not preferable. On the other hand, when the thickness of the circuit substrate 1 is 125 μm or more, it is difficult to apply the IC label on the curved surface, and the weight itself becomes heavy, which is inconvenient to handle. Therefore, the thickness of the circuit substrate 1 is preferably in the range of 30 μm to 125 μm.

  The antenna coil 2 is formed by screen-printing a conductive paint on the circuit substrate 1. The pattern of the antenna coil 2 is shown in FIG. The antenna coil 2 is formed of a coil pattern in which one wiring electrically connected at one end to the IC chip 3 forms a two-dimensional spiral shape toward the center direction. This spiral is a square spiral. Moreover, the insulation part 9 is formed so that a coil may be crossed on the one part area | region which comprises a coil. A wiring from the inside of the coil pattern passes over the insulating portion 9 and is taken out of the coil and electrically connected to the IC chip 3. Unlike the coil used for the conventional IC label, in the IC label according to the first embodiment, the antenna coil 2 has a two-dimensional pattern formed on the same plane as described above. In the case of a three-dimensional shape, the thickness of the IC label is increased by the thickness of the antenna coil 2, so that the IC label is difficult to bend and it is difficult to stick it on a curved surface. From the viewpoint of improving the sensitivity of the antenna coil 2, it is preferable to increase the cross-sectional area of the wiring and increase the number of turns of the coil.

  As the IC chip 3, for example, an I · CODE chip manufactured by Philips Semiconductors is used. The skin layer 4 is made of a flexible paper base material. The skin layer 4 protects the antenna coil 2 and the IC chip 3 from impact and can print characters and illustrations. The IC label according to the first embodiment can also be used as a normal label. . The adhesive layer 5 is made of an adhesive material such as rubber or acrylic. Normally, the adhesive layer 5 has a structure that is not exposed to the outside due to the presence of the release layer 6, but the release layer 6 and the adhesive layer 5 have a structure that can be easily separated. Therefore, when used, it is possible to attach an IC label by peeling the release layer 6 and bringing the adhesive layer 5 exposed to the outside into contact with a book or the like. The pressure-sensitive adhesive material forming the pressure-sensitive adhesive layer 5 is made of a material having a weaker adhesive force than the material used for the adhesive layer 7. This is to prevent the IC label from being broken due to separation of the skin layer 4 when the IC label once pasted is peeled off.

  Next, the manufacturing method of the IC label according to the first embodiment will be described with reference to FIG. 3 which is a cross-sectional view seen from the III-III direction of FIG.

  (A) First, the circuit substrate 1 is prepared, and the antenna coil 2 is formed on the circuit substrate 1 as shown in FIG. A spiral circuit pattern as shown in FIG. 2 is printed on the circuit substrate 1 using a conductive paint. Thereafter, the insulating portion 9 is printed on the partial area of the circuit pattern using an insulating paint as shown in FIG. Further, a wiring pattern for connecting the inside of the antenna coil 2 and the IC chip 3 is printed on the insulating portion 9.

  (B) Next, as shown in FIG. 3B, the IC chip 3 is mounted on the circuit substrate 1 with the anisotropic conductive adhesive 8. As shown in FIG. 2, both ends of the antenna coil 2 are pre-printed in the area where the IC chip 3 is mounted, and an anisotropic conductive adhesive 8 is applied on both ends of the antenna coil 2 to The antenna coil 2 is electrically connected. In the anisotropic conductive adhesive 8, conductive fine particles made of carbon, silver, copper or the like having a predetermined particle size distribution are uniformly dispersed in a base resin made of a thermosetting resin. Since most of the fine particles are dispersed independently, it has electrical insulation properties in the thickness direction and in the in-plane direction. However, by locally pressing the anisotropic conductive adhesive 8 in the thickness direction, the conductive fine particles come into contact with each other so that only the pressed portion has conductivity in the thickness direction, and the in-plane direction is It has a function of maintaining electrical insulation. Further, the anisotropic conductive adhesive 8 sandwiched between the IC chip 3 and both ends of the antenna coil 2 is thermally cured, so that the IC chip 3 can be firmly fixed on the circuit substrate 1 and anisotropic conductive adhesion is achieved. The compressed state of the agent 8 can be maintained as it is. In addition, when the anisotropic conductive adhesive 8 is used, the connecting portion between the antenna coil 2 and the IC chip 3 is thinner than when connected by wire bonding or the like, so that it can be easily applied to a curved surface. A functionally superior IC label can be manufactured.

  (C) Next, as shown in FIG. 3C, the skin layer 4 is formed on the circuit substrate 1 including the antenna coil 2 and the IC chip 3 via the adhesive layer 7. Specifically, the skin layer 4 is formed by sticking a paper base material coated with an adhesive on the circuit base material 1. For the adhesive layer 7, an acrylic resin is used alone or in the form of a solution, an aqueous solution or an emulsion. Characters, patterns, etc. are printed in advance on the paper base material used for the skin layer 4.

  (D) Next, an adhesive layer made of an acrylic ester resin, a vinyl chloride resin or the like is used in the form of a solution or an emulsion, whereby an adhesive layer is formed on the lower surface of the circuit substrate 1 as shown in FIG. 5 is formed.

  (E) Finally, the release layer 6 is attached to the lower surface of the adhesive layer 5. The release layer 6 is formed by coating one surface of a paper base material in order to reduce friction. As described above, as shown in FIG. 3E, the IC label according to the first embodiment is completed.

  Note that the method of manufacturing the IC label according to the first embodiment is not necessarily performed as described above. For example, the step of forming the adhesive layer 5 and the release layer 6 on the lower surface of the circuit substrate 1 may be performed in advance, and then the antenna coil 2 and the IC chip 3 may be formed on the circuit substrate 1. In addition to printing using a conductive paint as a method of forming the antenna coil 2, a copper foil or an aluminum foil is previously bonded to the surface of the circuit substrate 1, and unnecessary portions of the copper foil or the aluminum foil are etched. There is also a method of forming the film by removing the film.

  In addition, it can be used even if it is other than the above-mentioned polyethylene terephthalate as a material of the circuit base material 1 of the IC label according to the first embodiment. For example, as the material of the circuit substrate 1, a plate using a curable resin or a plate using a thermoplastic resin can be used. For thermosetting resins, phenol resin, urea resin, melamine resin, alkyd resin, acrylic resin, unsaturated polyester resin, diallyl phthalate resin, epoxy resin, silicone resin, resin synthesized from cyclopentadiene, tris (2-hydroxyethyl) Resin containing isocyanurate, resin synthesized from aromatic nitrile, trimerized aromatic dicyanamide resin, resin containing triallyl trimetallate, furan resin, ketone resin, xyle resin, thermosetting containing condensed polycyclic aromatics Resin or the like can be used as the material of the circuit substrate 1. Examples of the thermoplastic resin include polyolefin resins such as polyethylene, polypropylene, 4-methylpentene-1 resin, polybutene-1 resin, and high-pressure ethylene copolymer, styrene resin, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, poly Acrylonitrile, polyacrylic plastic, diene plastic, polyimide, polyester, polycarbonate, polyacetal, fluororesin, polyurethane plastic, polystyrene thermoplastic elastomer, polyolefin thermoplastic elastomer, polyurethane thermoplastic elastomer, polyester Thermoplastic elastomer, polyamide thermoplastic elastomer, low crystalline 1,2-polybutadiene, chlorinated polymer thermoplastic elastomer, It can be used system thermoplastic elastomer, or a thermoplastic elastomer, such as ion crosslinked thermoplastic elastomers, and the like as the material of the circuit substrate 1. Furthermore, these resins are impregnated with cloth or paper woven with insulating fibers such as glass fibers or cell sources, mixed with short fibers such as glass chopped strands or insulating whiskers, or film-like What was shape | molded in can be used.

  Further, the antenna coil 2 is not limited to the circuit pattern shown in FIG. 2, but may be other patterns such as meander lines. If the circuit pattern is such that the resonance frequency f0 for the free space of the resonance circuit included in the IC label is 2 to 8% higher than the oscillation frequency fosc of the reader / writer, which is a feature of the first embodiment, FIG. Any resonance circuit can be used for the IC label according to the first embodiment regardless of the circuit pattern of FIG.

  As for the IC chip 3, the I · CODE chip manufactured by Philips Semiconductors is used in the first embodiment, but the material of the IC chip 3 is naturally not limited to this. An IC chip having a capacitor and a semiconductor memory capable of writing and reading can be used as the IC chip 3 in the first embodiment. Furthermore, a capacitor is prepared separately and only the semiconductor memory is mounted. It is also possible to adopt a conventional IC chip.

For the skin layer 4, it is also preferable to use high-quality paper or a resin having writing ability. When the skin layer 4 is formed of a resin, the surface of the skin layer 4 can be provided with writing ability by applying surface coating with various resins or conductive materials, for example, in order to have toner printing ability. This is because not only information such as books is recorded in the IC chip, but also by directly writing characters and symbols, the information can be confirmed not only by the reader / writer but also visually.

  Further, as the material for the adhesive layer 7, in addition to the above-mentioned materials, resins such as styrene / butadiene copolymer, polyvinyl acetate, starch, silicone compounds, glue, casein, polyvinyl alcohol, and polyurethane can be used alone or in solution or aqueous solution. Can be used in the form of an emulsion.

  In addition to the materials described above, the adhesive layer 5 may be made of an adhesive base polymer such as natural rubber, modified natural rubber, styrene-butadiene rubber, acrylonitrile-butadiene rubber, or other synthetic rubber, or ethylene-vinyl acetate copolymer resin. Vinylidene chloride resin and the like can be used in the form of a solution or an emulsion.

Furthermore, in the IC label according to the first embodiment, a material having a lower adhesive strength than the adhesive layer 7 is used as the material of the adhesive layer 5, but the adhesive strength of the adhesive layer 5 is higher than that of the adhesive layer 7. Strong materials may be used. In this case, when the IC label once attached is peeled off, the IC label is separated between the skin layer 4 and the circuit substrate 1, and the antenna coil 2 or the IC chip 3 is damaged. Therefore, for example, when the information recorded on the IC label is highly confidential, there is an advantage that the content of the information cannot be easily known because the IC label is damaged.
As described above, according to the first embodiment of the present invention, the maximum communicable distance does not decrease even when a non-contact IC label is attached to a book. Further, it is possible to provide a non-contact type IC label that does not reduce the maximum communicable distance for almost all kinds of books having different thicknesses. Furthermore, since the sensitivity of the IC label does not decrease when a non-contact IC label is attached to a book, reading or writing can be performed without increasing the output of the reader / writer.

  Next, an IC label according to a modification of the first embodiment will be described. The structure of the IC label according to the modification of the first embodiment is similar to the IC label shown in FIGS. 1 and 2, and will be described with reference to FIGS. In the IC label according to the modification, an IC module is formed by arranging the antenna coil 2 and the IC chip 3 on the circuit substrate 1, and the upper surface of the circuit substrate 1 including the antenna coil 2 and the IC chip 3 is an adhesive layer. 7 is covered by the skin layer 4. In addition, the IC label according to this modification has the multilayer structure in which the adhesive layer 5 is formed under the circuit substrate 1 and the release layer 6 is formed under the adhesive layer 5. Same as chip. Then, the antenna coil 2 is set so that the resonance frequency f0 with respect to the free space of the resonance circuit including the capacitor included in the antenna coil 2 and the IC chip 3 is 8% to 12% higher than the oscillation frequency fosc of the reader / writer. Is configured.

  FIG. 8 shows the maximum distance that can be written and read by the reader / writer by distinguishing each IC chip when the IC chips having resonance frequencies f0 for various free spaces are attached to the book and the books are stacked. It is a graph. A solid line indicates a communicable distance when a single IC chip is used as a comparative example. The thin broken line shows only one book, the thick broken line shows two books stacked, and the alternate long and short dash line shows the resonance frequency f0 for the IC label free space and the reader / writer when the books are stacked. 3 shows the relationship of the maximum distance at which the IC chip can be identified and read and written. In addition, this 20 mm thick thing is used and the measurement is performed with the network analyzer (RX mode).

  According to FIG. 8, when the IC label is attached to one book (thin broken line) as compared with the case of the IC label alone (solid line), the peak frequency of the graph is higher than the peak frequency of the IC label alone. Shift about 0.9MHz. In addition, when IC labels are attached to two books and stacked on each other (thick broken line), the peak frequency of the IC label alone is shifted by about 0.5 MHz higher than when only one book is measured. To do. This is a shift of 8 to 12% with respect to the resonance frequency f0 of the IC label alone. When three books are stacked and measured (one-dot chain line), there is no peak frequency in the graph, and the maximum communicable distance does not decrease at a high resonance frequency f0. In addition, although measurement is not performed for four or more books, the peak frequency does not exist even when four or more books are stacked because the full width at half maximum increases and the peak intensity tends to weaken as the number of books stacked increases. It is thought that it becomes a flat graph.

  From the above results, when two or more books are stacked and an IC label is attached to each book, the frequency f0 (= reader / writer oscillation frequency at which the communication distance is maximum with the IC label alone is the maximum. By setting the resonance frequency f0 for free space 8-12% higher than fosc), it is possible to identify the IC label attached to each book and increase the communicable distance. . Even when three or more books are stacked, the maximum communicable distance does not decrease by setting the resonance frequency f0 for the free space of the IC label higher than the oscillation frequency fosc. Therefore, the IC label according to the modification of the first embodiment is set so that the resonance frequency f0 for the free space is set to 8 to 12% higher than the oscillation frequency fosc of the reader / writer, so that the IC labels attached to the stacked books are each It is possible to suppress a decrease in the maximum communicable distance with respect to.

  This makes it possible to read or write the information on each IC label affixed to the book without reducing the communication distance even when books are received in a piled-up state, for example, in a bookstore purchase. Advantages such as easy product management.

(Second Embodiment)
As shown in FIG. 4, the IC card according to the second embodiment includes an IC module 31, a first adhesive sheet 15 laminated on the IC module 31, and a first laminated on the first adhesive sheet 15. The oversheet 16 includes a second adhesive sheet 13 laminated on the lower surface of the circuit substrate 10, and a second oversheet 14 laminated on the lower surface of the second adhesive sheet 13.

  Here, the IC module 31 includes a circuit substrate 10, an IC chip 12 disposed on the circuit substrate 10, and an antenna coil 11 electrically connected to the IC chip 12 on the circuit substrate 10. . A resonance circuit is composed of the capacitor included in the IC chip 12 and the antenna coil 11. This resonance circuit is designed so that the resonance frequency f0 is higher than the oscillation frequency of the reader / writer.

  The IC card according to the second embodiment has an advantage that the strength against external impact is strong as compared with the IC label according to the first embodiment and its modification. The circuit substrate 10 is thicker than the IC label according to the first embodiment and its modification, and the first and second oversheets 16 and 14 are made of polyethylene terephthalate. This is because the thickness is larger than that when used as a material for the circuit substrate of the IC label in the form. Further, by providing the second oversheet 14 not only on the upper surface but also on the lower surface of the circuit base material 10, the structure can withstand an external impact.

  It is also effective that the IC card according to the second embodiment adopts a modified example structure as shown in FIG. The IC card shown in FIG. 6 is similar to the IC card shown in FIG. 4 in that the antenna coil 11 and the IC chip 12 are arranged on the circuit substrate 10. The oversheet structure is different. The oversheet 20 has a small thickness at a portion in contact with a region where the antenna coil 11 and the IC chip 12 are disposed, and is not in close contact with the circuit base material 10. The circuit base material 10 and the oversheet 20 are adhesive sheets. It adheres only through 19a, 19b, 19c. Therefore, the antenna coil 11 and the IC chip 12 are not in contact with the adhesive sheet and the oversheet 20, and the antenna coil 11 and the IC chip 12 are not directly affected even when an impact is applied from the top of the IC card. The possibility that the connection between the antenna coil 11 and the IC chip 12 is broken or the IC chip 12 is damaged due to an external impact is reduced. Further, since the antenna coil 11 and the IC chip 12 are not in contact with the oversheet 20 at all, there is an advantage that the flatness of the surface of the oversheet 20 is improved. In FIG. 6, the oversheet is not provided on the back surface of the circuit substrate 10 via an adhesive sheet, but it is also preferable to provide the same as the IC card shown in FIG. 4.

  In addition, as described above, the IC card according to the second embodiment has a resonance frequency f0 with respect to the free space of the circuit constituted by the antenna coil 11 and the IC chip 12 larger than the oscillation frequency fosc of the reader / writer. Takes a value. An IC card is used as, for example, an ID card. In this case, the IC card is mainly stored in an inner pocket or a wallet of clothes. Since these containers function as a dielectric as well as the book, the inductance L of the antenna coil included in the IC card changes as in the case where the IC label is attached to the book, and the resonance frequency fop during operation of the circuit is changed. It deviates greatly from the oscillation frequency fosc of the reader / writer. Therefore, in the past, even if the resonance frequency f0 for the free space of the resonance circuit included in the IC card is set so as to match the oscillation frequency fosc of the reader / writer at the design stage, the resonance frequency fop during operation is actually large. There has been a disadvantage that the maximum communicable distance of the IC card is lowered due to the deviation. Therefore, in the IC card according to the second embodiment, the resonance frequency f0 for the free space of the resonance circuit included in the IC card is designed in advance higher than the oscillation frequency fosc of the reader / writer. Therefore, even if the resonance frequency fop at the time of operation becomes small due to the presence of the dielectric, the resonance frequency fop at the time of operation can be kept within the range of ± 300 kHz of the oscillation frequency fosc of the reader / writer. As a result, the sensitivity of the IC card according to the second embodiment does not decrease despite the presence of the dielectric, and the maximum communicable distance can be maintained at the same level as that of the IC card alone.

  Next, an IC card manufacturing method according to the second embodiment will be described with reference to FIG. Note that not only the IC card shown in FIG. 4 but also the IC card shown in FIG. 6 can be manufactured by the following method.

  (A) First, a circuit substrate 10 having a copper foil 15 attached to the entire surface is prepared. Such a circuit substrate 10 may be commercially available, or may be formed by vapor-depositing copper on a substrate made of plastic or the like. As shown in FIG. 5A, resist patterns 17 a and 17 b corresponding to the connection terminals 18 for the antenna coil 11 and the IC chip 12 to be formed are formed on the copper foil 15. First, a resist is spin-coated on the entire surface of the copper foil 15, and then resist patterns 17a and 17b are formed by photolithography.

  (B) Next, the copper foil in regions other than the resists 17a and 17b is removed by chemical etching using the resist patterns 17a and 17b as etching masks. As a result, the antenna coil 11 and the connection terminal 18 are formed as shown in FIG.

  (C) Next, the IC chip 12 is electrically connected to the connection terminal 18 as shown in FIG. The connection method may be wire bonding or TAB (Tape Automated Bonding). Since the IC card itself has a certain thickness, even if it is connected by such a method, the problem does not arise as in the case of the IC label. Of course, the IC chip 12 and the connection terminal 18 may be connected using an anisotropic conductive adhesive as in the first embodiment.

  (D) Next, the first and second oversheets 16 and 14 are prepared. An overcoat (protective layer) is formed on the surfaces of the first and second oversheets 16 and 14 in advance, although printing and illustration of a pattern for decorating the card and necessary display are omitted. Further, the first and second adhesive sheets 15 and 13 are applied to the front surface and the back surface of the circuit substrate 10. In the case of the modification shown in FIG. 6, the adhesive sheets 19a, 19b, 19c are applied only to the portions where the oversheet 20 and the circuit substrate 10 are in contact. Then, the first oversheet 16 is adhered to the front surface of the circuit substrate 10, and the second oversheet 14 is adhered to the back surface of the circuit substrate 10. Next, an appropriate location in the region where the first and second adhesive sheets 15 and 13 are present is heated and temporarily fixed by an ultrasonic sealer. This is to prevent the circuit substrate 10 and the first and second oversheets 16 and 14 from being displaced when compressed by a press. After temporarily fixing, the substrate is set between the mirror plates, introduced into a press machine, and compressed. Thus, the IC card according to the second embodiment is completed as shown in FIG.

  In the IC card according to the second embodiment, the second adhesive sheet 13 and the second oversheet are formed on the back surface of the circuit substrate 10 when the purpose is to use in an environment where impact from the outside is weak. 14 may not be provided. Further, for the first and second adhesive sheets 13, 15 and the adhesive sheets 19a, 19b, 19c, the circuit board 10, the first and second oversheets 16, 14, and the oversheet 20 are made of vinyl chloride or PET- In the case of the G sheet, the adhesive sheet is unnecessary because it is self-fused by being compressed by a press. Further, the antenna coil 11 and the connection terminal 18 may be printed on the circuit substrate 10 with a conductive paint.

(Other embodiments)
As described above, the present invention has been described according to the first and second embodiments. However, it should not be understood that the description and drawings constituting a part of this disclosure limit the present invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

  For example, it is described that the IC label according to the first and its modified examples is attached to a book and used, but the application of the IC label according to the present invention is not limited to this. Even if it is not a book, the product to be attached functions as a dielectric, so when the oscillation frequency fosc of the reader / writer and the resonance frequency f0 for the free space of the circuit included in the single IC label are matched, By attaching the IC label to the product, the resonance frequency fop during operation is reduced, and the maximum communicable distance of the IC label is reduced. On the other hand, if the IC label according to the first embodiment is used, it is possible to suppress a decrease in the maximum communicable distance.

  It is also effective to attach and read the IC label according to the modification of the first embodiment to each of a large number of boxed products in the distribution process of the products and to perform writing and reading by a reader / writer. Further, when an IC label is used in an environment where water droplets are likely to adhere, the resonance frequency f0 for the free space of the circuit is set higher than the oscillation frequency fosc of the reader / writer in advance in consideration of the function as a water dielectric. It is also effective.

  Further, when the resonance frequency f0 for the free space of the resonance circuit included in the IC label is set to 8% higher than the oscillation frequency fosc of the reader / writer, each effect described in the first embodiment and its modification is 1 It can be realized with a single IC label. In that case, as an IC label to be attached to a book, even if the target of reading or writing information is one book or a plurality of books, there is an effect that the maximum communicable distance is not lowered and the sensitivity is not lowered. Will have.

  Further, the IC label or the IC card according to any one of the first and second embodiments has a configuration in which a resonance circuit including an IC chip and an antenna coil is disposed not only on the front surface of the circuit substrate but also on the back surface. It is also effective. In this case, a single IC label or IC card can be used for a plurality of reader / writers that oscillate at different frequencies fosc and obtain different information. Thereby, for example, the ID card and the commuting period can be combined into one IC card.

  Thus, it should be understood that the present invention includes various embodiments and the like not described herein. Therefore, the present invention is limited only by the invention specifying matters according to the scope of claims reasonable from this disclosure.

It is sectional drawing of the IC label which concerns on 1st Embodiment and its modification. It is a top view which shows the circuit pattern of the IC label which concerns on 1st Embodiment and its modification. It is a figure which shows the manufacturing method of the IC label which concerns on 1st Embodiment and its modification. It is sectional drawing of the IC card which concerns on 2nd Embodiment. It is a figure which shows the manufacturing method of the IC card which concerns on 2nd Embodiment. It is sectional drawing of the IC card of another structure concerning 2nd Embodiment. It is a graph which shows the relationship between the thickness of the book which affixes an IC label, and the resonant frequency fop at the time of operation | movement of an IC label. It is a graph which shows the relationship between the resonant frequency f0 with respect to the free space of an IC label, and the maximum communicable distance by using the number of books to which the IC label is attached as a parameter.

Explanation of symbols

1, 10 Circuit base material 2, 11 Antenna coil 3, 12 IC chip
4 Skin layer 5 Adhesive layer 6 Release layer 7 Adhesive layer 8 Anisotropic conductive adhesive 9 Insulating part
13, 15, 19a, 19b, 19c Adhesive sheets 14, 16, 20 Oversheets 17a, 17b, 17c Resist 18 Connection terminal 31 IC module

Claims (3)

A circuit substrate;
An IC chip containing a capacitor disposed on the circuit substrate;
An IC module comprising an antenna coil electrically connected to the IC chip on the circuit substrate. A circuit substrate;
A semiconductor memory disposed on the circuit substrate;
An IC module having a resonant circuit electrically connected to the semiconductor memory on the circuit substrate. The semiconductor memory is an IC chip,
The IC module according to claim 2, wherein the resonance circuit is an LC resonance circuit including a capacitor and an antenna coil.

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