RFID tag manufacturing method and RFID tag

A method of manufacturing RFID tags. A base sheet member is formed by fixedly attaching unit base substrates to a belt-like first sheet member at predetermined space intervals. Each unit base substrate is formed with an antenna pattern and has a non-contact communication-type IC chip mounted thereon. An upper-layer sheet member is formed by arranging reinforcing members between elastic, belt-like second and third sheet members, and is laminated on a surface of the first sheet member toward the unit base substrates such that each IC chip and each reinforcing member overlap each other in plan view. Regions each containing one unit base substrate are sequentially cut out from a laminate of the upper-layer sheet member and the base sheet member, thereby making RFID units.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority of the prior Japanese Patent Application No. 2008-255891, filed on Oct. 1, 2008, the entire contents of which are incorporated herein by reference.

FIELD

The embodiments discussed herein are related to a method of manufacturing an RFID tag including a circuit chip for noncontact communication with an external device, and the RFID tag.

BACKGROUND

Recently, attention has come to be paid to IC (Integrated Circuit) chips that are capable of contactlessly transferring and receiving information to and from external devices. For example, IC cards having such non-contact IC chips provided in card substrates thereof are widely used in electronic money, season tickets for transit systems, admission cards, and so forth.

Further, it has been proposed to cause such an IC chip to store an ID to thereby use the IC chip for identification and management of a commercial article or the like. A Non-contact IC chip thus used is referred to as an “RFID (Radio Frequency ID) tag”. In general, the RFID tag generates driving power based on radio waves or electromagnetic waves from a reader, and performs wireless communication with the reader, to transmit information, such as an ID stored in a memory of the IC chip, to the reader. Further, examples of the RFID tag include one which is capable of writing information in the memories of the IC chips, and one which is capable of executing processing, such as authentication processing with external devices, using received information or information stored therein.

By the way, many IC cards having non-contact IC chips installed therein are configured such that IC chips and antennas for communication are provided between card substrates made of resin. Further, as an IC card configured as above, to enhance the mechanical strength of the IC card, there has been proposed an IC card which is configured to sandwich both surfaces of the IC chip using a reinforcing member such as metal (see e.g. Japanese Laid-open Patent Publication No. 2003-141486). Further, it has been proposed that a reinforcing plate, which opens in portions thereof corresponding to electrodes of an IC chip, is directly joined to a main surface of the IC chip to thereby reduce the thickness of an IC card (see e.g. Japanese Laid-open Patent Publication No. 2000-200333). Further, there has been proposed an IC card which has a fiber material provided as a reinforcing material between a module package and a card substrate that have an IC chip and coils installed therein (see e.g. Japanese Laid-Open Patent Publication No. H10-181261).

On the other hand, in general, RFID tags as well are provided in a form in which an IC chip is integrally modularized e.g. with a communication antenna. Such a RFID tag as well is required to enhance the strength thereof with respect to a bending force and the like. Furthermore, it is designed to attach a RFID tag e.g. to clothing. Such RFID tags are further required to have resistance to liquids or chemicals. To solve these problems, it is proposed to manufacture RFID tags each by laminating reinforcing members and an IC chip one upon another and sealing a module having the IC chip integrated therein with a protective sheet.

However, it takes labor and time to manufacture the RFID tags each having reinforcing members arranged therein and an internal circuit sealed with a protective sheet, which results in an increase in manufacturing costs thereof.

For example, when a RFID tag is made, although a sheet-like substrate itself, which is formed with antenna patterns in advance, can be prepared with such a small thickness that enables the same to be wound around a roll or the like. However, when an IC chip is attached to the sheet-like substrate, and reinforcing members are mounted on the IC chip, both the IC chip and the reinforcing members have large bending resistances, which makes it difficult to cause the sheet-like substrate to be taken up by a roll again. Therefore, for example, a sealing process using a protective sheet is required to be performed by batch processing after the sheet-like substrate is cut in units of one or a plurality of IC chips. As described above, when it is impossible to continuously laminate reinforcing members and protective sheets in a state where a sheet-like substrate is wound around a roll, it is difficult to manufacture a large number of RFID tags at low cost.

SUMMARY

According to an aspect of the invention, a method of manufacturing an RFID tag includes forming a base sheet member that includes unit base substrates each of which is formed with a conductive pattern functioning as an antenna, and has a non-contact communication-type circuit chip mounted thereon which is connected to the conductive pattern, and a first sheet member in a belt-like form, the unit base substrates being fixedly attached to the first sheet member at predetermined space intervals along a direction of length of the first sheet member, laminating a second sheet member and a third sheet member each in a belt-like form and having elastic properties, one upon another, in a state where reinforcing members for reinforcing the circuit chips are arranged between the second sheet member and the third sheet member at the same space intervals as the space intervals at which the circuit chips are arranged, thereby forming an upper-layer sheet member, and laminating the upper-layer sheet member on a side of the base sheet member formed by the forming where each unit base substrate is laminated, in a state where each circuit chip and each reinforcing member overlap upon each other in plan view of the sheet members, and cutting out regions each including one of the unit base substrates sequentially from a sheet laminate formed by the laminating.

DESCRIPTION OF EMBODIMENT(S)

Embodiments of the present invention will be explained below with reference to the accompanying drawings, wherein like reference numerals refer to like elements throughout.

In the following embodiments, a noncontact IC chip has e.g. the functions of generating driving power based on electric waves or electromagnetic waves from an external device, communicating with the external device, and transmitting information stored in a storage circuit provided in the noncontact IC chip to the external device. Further, the IC chip may be one which is capable of storing information transmitted from an external device in an internal storage circuit thereof or one which is capable of carrying out various processes, such as an authentication process between the same and the external device, using received information and stored information.

FIG. 1is a cross-sectional view of an RFID tag according to a first embodiment.

The RFID tag illustrated inFIG. 1is realized in a state in which a circuit component that serves as an RFID tag is sealed with seat members. In the following description, the RFID tag is referred to as the “RFID unit”.

Referring toFIG. 1, the RFID unit1comprises three sheet members11to13, which are laminated one upon another. Although a resin material, elastomer, or the like is used as a material for the above sheet members11to13, for example, it is desirable that at least one of the sheet member12and the sheet member13has elastic properties.

A unit base substrate22having a noncontact IC chip21mounted thereon is disposed between the sheet member11and the sheet member12. The unit base substrate22is formed with a conductor pattern (not shown) serving as an antenna, and the IC chip21is connected to the conductor pattern. Here, the sheet members11and12have a larger area than that of the unit base substrate22, and are brought into contact with each other in regions surrounding the unit base substrate22, and fixedly attached to each other. With this configuration, the IC chip21and the conductor pattern are sealed with the sheet members11and12. Therefore, even when a liquid or a chemical is attached to the RFID unit1, it is possible to positively protect the IC chip21and the conductor pattern.

Further, the sheet members12and13form an upper sheet member14which is laminated on the sheet member11, and a reinforcing member23for reinforcing the IC chip21is disposed between the sheet members12and13at a location corresponding to the IC chip21. In the example illustrated inFIG. 1, the reinforcing member23is completely sealed with the sheet members12and13. With this configuration, when an external force, such as a bending force, is applied to the RFID unit1, it is possible to prevent the IC chip21from being broken. In the case of this configuration, a hard material, such as a resin material, a ceramic material, or a metal material, is used as the reinforcing member23.

FIG. 2explains a method of manufacturing the RFID tag according to the first embodiment.

FIG. 2is a plan view illustrating part of a process for manufacturing the RFID tag in the present embodiment. In the present embodiment, belt-like sheet materials corresponding to the respective sheet members11to13are laminated one upon another, and a plurality of circuit components, such as IC chips21, each of which forms an RFID tag, are arranged in parallel between the sheet materials. Then, after the sheet materials are laminated and fixedly attached to each other, predetermined regions of the resulting laminate are cut out. By carrying out such process steps, a large number of RFID units1are efficiently manufactured.FIG. 1corresponds to a cross-sectional view of a cut-out region “A” taken on line X-X ofFIG. 2.

A process for manufacturing the RFID unit1is roughly classified into a first process step for fixedly attaching the unit base substrate22having the IC chip21mounted thereon to the sheet member11, a second process step for laminating the upper sheet member14on the sheet member11to fixedly attach the sheet members11and14to each other, and a third process step for cutting out respective regions of RFID tags from the sheet member laminate.

In the first process step, the belt-like sheet material corresponding to the sheet member11is provided e.g. in a state wound up around a roll. Then, the unit base substrates22having the respective IC chips21mounted thereon are fixedly attached to the belt-like sheet material side by side along the direction of the length thereof. The belt-like sheet material having the unit base substrates22fixedly attached thereto can be taken up by a roll.

In the second process step, the belt-like sheet materials corresponding to the respective sheet members12and13are provided e.g. in a state wound up around rolls. Here, the reinforcing members23are fixedly attached to one of the sheet members12and13at the same intervals as the intervals at which the unit base substrates22are arranged. Then, the above-described belt-like sheet materials corresponding to the sheet members11to13are sequentially pulled out from the rolls, for being laminated one upon another, and adjacent ones of the belt-like sheet materials are fixedly attached to each other e.g. by thermocompression bonding. At this time, the belt-like sheet materials are placed in the state illustrated inFIG. 2.

In the third process step, each cut-out region “A” corresponding to one RFID tag is cut out from the laminate formed by laminating the belt-like sheet materials one upon another in the second process step, using e.g. a punching die. This manufactures the RFID units1.

According to the above-mentioned manufacturing process, the unit base substrates22each having the IC chip21and the conductor pattern24mounted thereon are fixedly attached in advance to the belt-like sheet material corresponding to the sheet member11, and the reinforcing members23are arranged in advance between the belt-like sheet materials corresponding to the respective sheet members12and13, whereafter these belt-like sheet materials are subjected to the above-mentioned second process step.

More specifically, conventionally, a protective sheet has to be laminated onto a sheet-like substrate in a state where both IC chips21and reinforcing members23are mounted thereon, and hence the bending resistances of the IC chips21and the reinforcing members23make it impossible to roll up the sheet-like substrate in advance. In contrast, according to the present embodiment, while the IC chips21are mounted on a belt-like sheet corresponding to the sheet member11, the reinforcing members23are disposed between belt-like sheets corresponding to the sheet members12and13. That is, a set of IC chips21and a set of reinforcing members23can be arranged separately in respective different belt-like sheets. As a consequence, the bending resistances of the respective sheet members become lower than when both the IC chip21and the reinforcing member23are mounted on the sheet-like substrate, whereby it is possible to roll up the belt-like sheets around a roll.

Then, after the above sheet members have been laminated one upon another, a final form of RFID tags before being cut out is completed. Therefore, if a final product is cut out in this state, it becomes unnecessary to roll up the belt-like sheets around a roll, in the state in which both the IC chip21and the reinforcing member23are mounted.

Thus, it is possible to employ the manufacturing method in which all the belt-like sheet materials to be laminated are rolled around rolls, and are sequentially pulled out from the rolls, for being laminated one upon another. This makes it possible to efficiently manufacture a large number of RFID units1.

As a method of manufacturing the unit base substrates22, it is possible to employ e.g. a method of preparing a belt-like base substrate which has a large number of conductor patterns24arranged side by side in a longitudinal direction, mounting the IC chips21on the respective conductor patterns24, and then cutting the respective regions of the unit base substrates22off the belt-like base substrate.

Further, as a method different from the above method, it is also possible to employ a method of directly manufacturing a belt-like sheet material corresponding to the sheet member11and having a large number of unit base substrates22arranged thereon in the direction of the length thereof, without cutting off the individual unit base substrates22. More specifically, first, a belt-like sheet material having an adhesive agent attached to one surface thereof is affixed to a belt-like base substrate corresponding to the unit base substrates22. At this time, the belt-like sheet material is affixed to a surface of the belt-like base substrate, opposite to a surface thereof on which the IC chips21are mounted. Next, peripheral edges of regions of the belt-like base substrate, each including one IC chip21and the conductor pattern24connected thereto, is cut through together with a layer of the adhesive agent. At this time, the belt-like sheet material corresponding to the sheet member11is not cut through. Then, only an outer portion of the belt-like base substrate surrounding the cut-off regions thereof is removed from the belt-like sheet material. As a consequence, only the respective regions of the unit base substrates22are left behind on the belt-like sheet material.

If the above method is employed, after the sheet-like substrate having a large number of unit base substrates22affixed thereto is once taken up by a roll, it is possible submit the belt-like sheet material to the above-described lamination process step, thereby making it possible to further enhance manufacturing efficiency.

Although in the examples illustrated inFIGS. 1 and 2, the reinforcing member23is disposed only above the IC chip21, it is possible to dispose the same reinforcing member also below the IC chip21. In this case, it suffices that with a reinforcing member attached to a lower surface of the sheet member11, another sheet member is laminated thereon in a manner sandwiching the reinforcing member, and is fixedly attached to the sheet member11. In this case, however, at least one of the sheet member11and the sheet member provided thereunder is formed in advance using an elastic material.

Further, although in the examples illustrated inFIGS. 1 and 2, the reinforcing members23are separately arranged for reinforcing the individual IC chips21, respectively, mesh-like reinforcing members may be used in place of the above reinforcing members23. In this case, between belt-like sheet materials corresponding to the sheet members12and13, each belt-like reinforcing member in a mesh extending in the direction of the length of the sheet members12and13is sandwiched in advance. Then, after the belt-like sheet materials are laminated and fixedly attached by the same method as described above, regions corresponding to the RFID units1are cut out. According to this method, it is possible to further enhance the efficiency of the process step for arranging the reinforcing members.

Further, as described hereinafter, when the mesh-like reinforcing members are used, a method may be employed which omits the process step for fixedly attaching the unit base substrates22in advance to the belt-like sheet material corresponding to the sheet member11. In this case, openings are formed in advance through the belt-like base substrate having the conductor patterns24formed side by side thereon, and after the IC chips21are connected to the respective conductor patterns24, laminating members each including the two layers of the belt-like sheet materials which sandwich the mesh-like reinforcing member are laminated on the respective opposite surfaces of the belt-like base substrate, whereafter the laminating members are fixedly attached to each other via the openings.

Next, a more detailed description will be given of an embodiment of the method of manufacturing the RFID tag. In the following description, first, to facilitate comparison between the method of manufacturing the RFID tag according to the embodiments and the prior art, an example of a general process for manufacturing the RFID tag will be described with reference toFIGS. 3A and 3BtoFIGS. 8A and 8B. Then, examples of the RFID tag-manufacturing process which solve the problems of the general RFID tag-manufacturing process will be described as second to fifth embodiments.

FIGS. 3A and 3BtoFIGS. 8A and 8Bexplain a process step for mounting IC chips in the general RFID tag-manufacturing process.FIG. 3Ais a side view illustrating how this process step is carried out, andFIG. 3Bis a plan view illustrating the same.

Referring toFIGS. 3A and 3B, an antenna substrate101is a sheet-like or film-like substrate having a large number of antenna patterns102formed at predetermined space intervals. The antenna patterns102are formed on a surface of the substrate using an electrically conductive material, such as aluminum, e.g. by a printing technique or a thin film-forming technique. In the examples illustrated inFIGS. 3A and 3B, each antenna pattern102is linearly formed with a gap at an approximately central portion thereof. Further, as another example of the shape of the antenna pattern102, there may be mentioned a loop-like or spiral-like shape.

In a process step for mounting noncontact IC chips103, the antenna substrate101formed with the antenna patterns102, as described above, is provided in a state wound around a roll121. By rotating the roll121, the antenna substrate101is sequentially pulled out onto a stage122, and the IC chips103are sequentially mounted to the antenna substrate101on the stage122.

The IC chips103are mounted e.g. by flip chip bonding using a bonding tool123. Each IC chip103has a lower surface or a side surface formed with two antenna terminals, not illustrated, and these antenna terminals are connected to respective portions of each antenna pattern102, separated by the gap. The antenna substrate101having the IC chips103mounted through the above-described process step are taken up by the roll again.

FIG. 4explains a process step for mounting the reinforcing members on the antenna substrate101in the general RFID tag-manufacturing process.

After the IC chips103are mounted on the antenna substrate101, and the antenna substrate101is wound around a roll131, reinforcing members104for reinforcing the IC chips103are attached to the antenna substrate101in the next process step. As the reinforcing member104, there can be used a resin material, such as FRP (Fiber-reinforced Plastic), a ceramic material or a metal material. In the example illustrated inFIG. 4, the reinforcing member104is formed to have a shape of a flat plate.

When the antenna substrate101is pulled out from the roll131onto a stage132, first, an adhesive agent is applied to the IC chips103on the antenna substrate101by a dispenser133. Next, the reinforcing members104are placed on the upper surfaces of the IC chips103coated with the adhesive agent, by a bonding tool134, and further the adhesive agent is cured by heat from a heat source135.

When the reinforcing members104are fixedly attached to upper portions of the IC chips103, as described above, projections formed by the IC chips103, the adhesive agent and the reinforcing members104come to exist on the antenna substrate101, which makes it difficult to take up the antenna substrate101by a roll. To solve the above problem, the antenna substrate101is cut by a cutter136in units of a single or a plurality of IC chips103. Then, cut-off parts of the antenna substrate101are conveyed to a device used in the next process step. In the example illustrated inFIG. 4, the antenna substrate101is cut into units of regions each with three IC chips103mounted thereon.

FIGS. 5A and 5Bexplain a process step for cutting out RFID inlets in the general RFID tag-manufacturing process.FIG. 5Ais a side view illustrating how this process step is carried out, andFIG. 5Bis a plan view illustrating the same.

After being placed on a stage141, the antenna substrate101cut as described above is punched by a punching die142along dotted lines inFIG. 5B, whereby a group of electronic components constituting an RFID tag are packaged whereby an RFID inlet105is formed.

FIGS. 6A and 6BandFIG. 7explain an RFID inlet-sealing process step in the general RFID tag-manufacturing process.

First, as illustrated inFIGS. 6A and 6B, a plurality of RFID inlets105manufactured in the above-described process step are placed side by side on a lower protective sheet106aas a lower packaging material. A resin material, such as PET (Polyethylene Terephthalate), EPDM (Ethylene Propylene Diene Terpolymer) or silicone rubber is used as a material for the lower protective sheet106a.FIG. 6Ais a plan view illustrating how eight RFID inlets105are arranged side by side, by way of example, andFIG. 6Bis a side view illustrating the same.

Next, as illustrated inFIG. 7, on a table151, an intermediate protective sheet106band an upper protective sheet106care further placed on an upper surface of the lower protective sheet106ahaving the RFID inlets105placed thereon. The intermediate protective sheet106bhas a thickness equal to or larger than the thickness of the RFID inlet105, and is configured such that regions corresponding to respective locations of the RFID inlets105are hollowed.

Next, the above-mentioned protective sheets are pressurized by a press head152from above the upper protective sheet106cdownward, and are heated. Here, when the lower protective sheet106a, the intermediate protective sheet106b, and the upper protective sheet106care made of the above-mentioned resin material, the protective sheets are fixedly attached to each other by being pressurized and heated, whereby the RFID inlets105are sealed.

FIGS. 8A and 8Bexplain a final product-cutting process step for cutting out a final product, in the general RFID tag-manufacturing process.FIG. 8Ais a side view illustrating how this process step is carried out, andFIG. 8Bis a plan view illustrating the same.

InFIGS. 8A and 8B, a protective sheet106indicates a region in a state in which the lower protective sheet106a, the intermediate protective sheet106band the upper protective sheet106c, described above, are fixedly attached to each other. In the process step illustrated inFIGS. 8A and 8B, regions each including one RFID inlet105are punched out by a punching die161, whereby RFID units107, which are final products, are manufactured.

Through the above-described process steps illustrated inFIGS. 3A and 3BtoFIGS. 8A and 8B, there are manufactured the RFID units107in each of which the whole of the RFID inlet105having the IC chip103and the antenna pattern102reinforced by the reinforcing member104mounted thereon is sealed with the protective sheet106. The RFID unit107is resistant to external forces, such as a bending force and a pressing force, and at the same time even when the RFID unit107is placed in a liquid or a chemical, the inside of the RFID unit107is prevented from being corroded.

However, in the above general manufacturing method, after the process step for mounting the IC chips103and the reinforcing members104on the antenna substrate101, it becomes difficult to take up the antenna substrate101by a roll, and hence it is necessary to proceed to the remaining process steps after the RFID inlets105are cut out from the antenna substrate101. Although the method of manufacturing the RFID tag using rolls is very efficient since a continuous antenna substrate can be easily carried and be sequentially pulled out from a roll for continuously mounting component parts thereon, the above-mentioned manufacturing method suffers from the problem that the method of manufacturing the RFID tag using rolls can be applied only up to an intermediate process step, which degrades manufacturing efficiency.

Further, in the process step for sealing the cut-out RFID inlets105, to make flat the upper surface of the protective sheet106, it is necessary to use the intermediate protective sheet106bhaving a shape matching the respective locations of the RFID inlets105. Therefore, in the process step for sealing the RFID inlets105, it is necessary to convey the cut-out RFID inlets105to respective predetermined locations for accurately positioning the same. This makes the process step complicated.

In the embodiments of the present invention, it is an object to manufacture products having approximately the same specifications as those of the above-mentioned RFID unit107, from start to finish, by the manufacturing method using rolls, thereby making it possible to manufacture a large number of products at low costs.

Although in the embodiments of the present invention, the antenna pattern is linearly formed, it is possible to use an antenna pattern having a loop-like or spiral-like shape.

Second Embodiment

FIG. 9is a flowchart illustrating the outline of a process for manufacturing RFID units according to a second embodiment.

[Step S21] In the second embodiment, a mesh-like sheet material is used as an IC chip-reinforcing member. First, a sheet laminate is prepared by sandwiching a mesh-like reinforcing member by elastic protective members. The prepared sheet laminate is rolled up around rolls.

[Step S22] On the other hand, an antenna substrate formed with an antenna pattern is prepared by the same method as used in the above-described general RFID tag-manufacturing process. The prepared antenna substrate is taken up by a roll.

[Step S23] IC chips are mounted on the antenna substrate by the same method as used in the above-described general RFID tag-manufacturing process. The antenna substrate having the IC chips mounted thereon can also be taken up by a roll.

[Step S24] Slits are formed in respective predetermined locations of the antenna substrate having the IC chips mounted thereon. The antenna substrate formed with the slits is taken up by a roll.

[Step S25] The antenna substrate having the slits formed in the step S24is sandwiched from opposite sides by the sheet laminates prepared in the step S21, and the sheet laminates are fixedly attached to each other. Further, the member formed by fixedly attaching the sheet laminates is cut out in units of regions of respective RFID tags to thereby complete RFID units. In this process step, by pulling out the antenna substrate and the sheet laminates from the respective rolls thereof at the same speed, it is possible to fixedly attach the sheet laminates to each other and further cut out the RFID units.

Next, a more detailed description will be given of the above-mentioned process steps.

FIGS. 10A and 10Bexplain a sheet laminate-preparing process step according to the second embodiment.FIG. 10Ais a side view illustrating how this process step is carried out, andFIG. 10Bis a plan view illustrating the same.

The process step illustrated inFIGS. 10A and 10Bcorresponds to the step S21inFIG. 9. In this process step, a sheet-like nylon mesh201and rubber sheets202aand202bare provided in states wound around rolls221,222aand222b, respectively, and a sheet laminate is prepared by laminating the sheet-like nylon mesh201and the rubber sheets202aand202b.

Here, the nylon mesh201is used as a reinforcing member for noncontact IC chips, and has a width at least large enough to cover the whole of each IC chip. The material for the reinforcing member is not limited to nylon but any of resin materials and metal materials, including metal nets, may be used as the material for the reinforcing member insofar as it is in the form of a mesh. However, it is desirable that the material has a certain degree of rigidity, and is difficult to extend and at the same time bendable to a certain degree. Further, to maintain an excellent communication performance of the IC chips, it is desirable that the material is non-conductive.

On the other hand, as described hereinafter, the rubber sheets202aand202bare sheet members in contact with the IC chips or a substrate on which the IC chips are mounted, and are provided for protecting the IC chips or the substrate. Although the material for the protective sheet members may be a resin material or one of other materials, such as elastomer, it is desirable that when the IC chips are pressed against the material, the material has elastic properties large enough for the IC chips to sink. Further, as described hereinafter, it is desirable that the material can be thermocompression-bonded.

The nylon mesh201and the rubber sheets202aand202bare pulled in between rollers223aand223bfrom the rolls221,222aand222b, and are laminated one upon another. At this time, the nylon mesh201is vertically sandwiched between the rubber sheets202aand202b, and the resulting laminate is taken up by a roll224.

In the above process step, it is not particularly necessary to attach the nylon mesh201to the laminated rubber sheets202aand202b. However, for example, the opposite surfaces of the nylon mesh201, or respective surfaces of the rubber sheets202aand202b, opposed to the nylon mesh201, are coated with an adhesive agent such that the opposed surfaces thereof are attached to each other.

FIGS. 11A and 11Bexplain a slit-forming process step according to the second embodiment.FIG. 11Ais a side view illustrating how this process step is carried out, andFIG. 11Bis a plan view illustrating the same.

As described above in the step S22inFIG. 9, the antenna substrate formed with the antenna pattern is prepared, separately from the sheet laminate. Next, as described above in the step S23inFIG. 9, the IC chips are mounted on the prepared antenna substrate. This process step is the same as the IC chip-mounting process step in the general RFID tag-manufacturing process, described above with reference toFIGS. 3A and 3B, and illustration thereof is omitted. It is assumed here that an antenna substrate203, antenna patterns204and IC chips205illustrated inFIGS. 11A and 11Bcorrespond to the antenna substrate101, the antenna patterns102and the IC chips103illustrated inFIGS. 11A and 11B, respectively.

The antenna substrate203having the IC chips205mounted thereon is once taken up e.g. by a roll231, and then is subjected to the slit-forming process step illustrated inFIGS. 11A and 11B. Now, the size of the IC chips205is small e.g. with respect to the width of the antenna substrate203, and further the height thereof is low with respect to the height of e.g. the above-described reinforcing members104, so that the antenna substrate203having only the IC chips205mounted thereon can be relatively easily wound around the roll231.

Next, slits are formed in the antenna substrate203using a punching die233while the roll231is rotated to sequentially pull out the antenna substrate203onto a stage232. In the examples illustrated inFIGS. 11A and 11B, slits203aare formed in regions between the antenna patterns204arranged in parallel with each other, and slits203bare formed in regions on the opposite longitudinal ends of each antenna pattern204.

These slits are formed to bring rubber sheets on opposite ends of the antenna substrate203into contact with each other and cause them to be fixedly attached to each other by thermocompression bonding in a sheet-attaching process step, described hereinafter. Therefore, the size of the slits and locations for forming the slits are determined such that a sufficient attaching force is caused by thermocompression bonding. Further, basically, the regions for forming the slits are not limited insofar as they do not include the IC chips205and the antenna patterns204. However, as described hereinafter, the size of a portion of the antenna substrate203, exposed from a side surface of a completed RFID unit can be reduced depending on the locations where the slits are formed and the size of the slits.

The antenna substrate203formed with the slits are taken up by a roll again. As this roll, there may be used the original roll231around which the antenna substrate203has been wound, or another roll provided toward the other end of the antenna substrate203.

The formation of the slits as described above may be performed in the step S23immediately before or immediately after the IC chips205are mounted on the antenna substrate203. Alternatively, in the step S21, the slits may be formed in advance in the antenna substrate203provided for forming the antenna patterns102.

FIGS. 12A and 12Bexplain a sheet-attaching/unit-cutting process step according to the second embodiment.FIG. 12Ais a side view illustrating how this process step is carried out, andFIG. 12Bis a plan view illustrating the same.

The process step illustrated inFIGS. 12A and 12Bcorresponds to the step S25inFIG. 9. In this process step, first, sheet laminates206aand206bformed in the step S21, respectively, are arranged on opposite surfaces of the antenna substrate203having the slits formed in the step S24. Referring toFIGS. 12A and 12B, the antenna substrate203and the sheet laminates206aand206bare pulled out from rolls241,242aand242b, respectively, and are conveyed while being vertically pressurized by rollers243aand243b. In accordance therewith, heat is applied e.g. by the rollers243aand243b, or from a heat source, not illustrated, other than the rollers243aand243b.

Thus, a rubber sheet as a lower layer of the sheet laminate206a, i.e. on a side opposed to the antenna substrate203and a rubber sheet as an upper layer of the sheet laminate206bare thermocompression-bonded to each other via the slits formed in the antenna substrate203, whereby the IC chips205and the antenna patterns204are sealed with the rubber sheets. Further, a rubber sheet as an upper layer of the sheet laminate206aand the rubber sheet as the lower layer of the sheet laminate206aare thermocompression-bonded to each other via gaps of the nylon mesh201between the rubber sheets. Similarly, the rubber sheet as the upper layer of the sheet laminate206band a rubber sheet as a lower layer of the sheet laminate206bare thermocompression-bonded to each other via gaps of the nylon mesh201between the rubber sheets.

Now, the rubber sheet as the lower layer of the sheet laminate206ahas elastic properties, so that when press-fitted into the antenna substrate203, the rubber sheet is contracted only by the height of the IC chip205. This holds the upper surface of the sheet laminate206aapproximately flat. To make flat the upper surface of the sheet laminate206a, recesses may be formed in advance in the rubber sheet e.g. according to the shape of the IC chip205. However, in this case, in the process step for fixedly attaching the sheet laminates206aand206bthat have the antenna substrate203therebetween, it is possible to position the recesses on the sheet laminate206ato the locations of the IC chips205.

The sheet members thermocompression-bonded to each other as described above are cut out by a punching die244in units of regions each including one IC chip205and one antenna pattern204connected to the IC chip205. The units cut out in this process step become RFID units, which are final products. InFIG. 12B, the regions cut out by the punching die244are indicated as cut-out regions207. In the present embodiment, the cut-out regions207are configured to pass through the insides of the respective slits203aand203bformed in the antenna substrate203.

In the present embodiment, the sheet laminates206aand206bprepared in advance in the step S21are subjected to the step S25. However, for example, in the step S25, the laminating and fixedly attaching of each of the sheet laminates206aand206bmay be performed simultaneously with the laminating and fixedly attaching of the sheet laminates206aand206band the antenna substrate203.

FIGS. 13A and 13Billustrate the RFID unit made in the second embodiment.FIG. 13Ais a plan view illustrating the same, andFIG. 13Bis a side view illustrating the same.

Referring toFIGS. 13A and 13B, in the RFID unit prepared in the present embodiment, the IC chip205and the antenna pattern204are sealed with the rubber sheets as protective members. Therefore, even when a liquid or a chemical is attached to the RFID unit, it is possible to cause the IC chip205to normally operate while preventing the liquid or the chemical from touching the IC chip205and the antenna pattern204within the RFID unit.

Further, the layers of the nylon mesh201are formed above and below the IC chip205. Therefore, even when pressure or a bending force is applied to the RFID unit from the outside, the IC chip205is protected. The reinforcing effects of the nylon mesh201will be described in more detail with reference toFIGS. 14A and 14B.

Further, end faces of the nylon mesh201are exposed from side surfaces of the RFID unit. However, since the nylon mesh201, the IC chip205and the antenna substrate203are completely separated from each other by the rubber sheets, the operation of the IC chip205is not influenced by the exposure of the nylon mesh201.

In the RFID unit, however, end faces of the antenna substrate203are partially exposed from the side surface of the RFID unit. Therefore, it is desirable to determine the locations and size of the slits formed in the antenna substrate203before being cut, and the respective locations of regions from which the RFID units are cut out, such that the exposed portion of the antenna substrate203is minimized.

In the present embodiment, in the process step for cutting out the RFID units, illustrated inFIGS. 12A and 12B, the cut-out regions207are configured to pass through the insides of the respective slits203aand203bformed in the antenna substrate203. As a consequence, the portion of the antenna substrate203, exposed from the side surface of each RFID unit becomes only a region located between the slit203aand the slit203badjacent to the slit203a. InFIGS. 13A and 13B, this region is indicated as an exposed region208.

Therefore, in the present embodiment, in the antenna substrate203yet to be cut, it is desirable to maximize the length of the slits203adisposed between the antenna patterns204arranged side by side, in a direction parallel to each antenna pattern204(left-right direction inFIGS. 13A and 13B). In addition, it is desirable to configure the size of the slit203band the location of the cut-out region207such that the length of the RFID unit in a direction orthogonal to the antenna pattern204(vertical direction inFIG. 13A) becomes not larger than the length of the slits203bin the same direction which are formed at the opposite longitudinal ends of each antenna pattern204.

For example, inFIGS. 12A and 12B, the width of the antenna substrate203may be made smaller than the width of the sheet laminates206aand206b, while the length of the cut-out region207in the direction of the width thereof may be made larger than the width of the antenna substrate203. In this case, the slits203bare not formed, and the opposite ends of the antenna substrate203in the direction of the length of the antenna pattern204are prevented from being exposed from the opposite ends of the RFID unit.

FIGS. 14A and 14Bexplain the reinforcing effects of the nylon mesh.

FIG. 14Aillustrates the cross-section of a protective member used in the above-described RFID unit, i.e. a rubber sheet. When such a sheet member is bent such that an upper half thereof with respect to the center line of the sheet member, as viewed inFIG. 14A, becomes convex, in general, as illustrated on the right side inFIG. 14A, a tensile stress acts on the upper half of the sheet member, and a compressive stress acts on a lower half of the same.

In the RFID unit prepared in the present embodiment, the layers of the nylon mesh201are formed above and below the IC chip205. Now, when nylon meshes201having a low elongation are used, as illustrated inFIG. 14B, if the RFID unit is bent such that an upper half thereof, as viewed inFIG. 14A, becomes convex, an upper nylon mesh201is less elongated, whereby the rubber sheet in the region of the upper nylon mesh201is difficult to be bent. Inversely, if the RFID unit is bent such that a lower half thereof, as viewed inFIG. 14B, becomes convex, a lower nylon mesh201is less elongated, and hence the rubber sheet in the region of the lower nylon mesh201is difficult to be bent, similarly to the above case. This makes it possible to positively protect the IC chip205from the bending force.

In the above-described second embodiment, the process step is employed in which a mesh-like material is used for making reinforcing members of the IC chips, and sheet laminates are prepared by arranging the mesh-like reinforcing members on a protective sheet member. This makes it possible to manufacture the RFID units from start to finish, by using rolls. Further, since a material that can be thermocompression-bonded is used for making the protective sheet member, it is possible to efficiently carry out the process step for laminating the above-mentioned sheet laminates and the antenna substrate having the IC chips mounted thereon and fixedly attaching the same. Furthermore, an elastic material is used as the protective sheet member, whereby when the sheet laminates and the antenna substrate are fixedly attached, it is possible to make flat the upper surface of the sheet laminate without performing particular positioning (of the sheet laminates and the IC chips) in the conveying direction of the sheet laminates and the antenna substrate. This makes it possible to manufacture a large number of RFID units, which are resistant to external forces, liquids or chemicals, at low costs.

Third Embodiment

By the way, the RFID unit manufactured in the above-described second embodiment is configured such that part of the reinforcing members or the antenna substrate is exposed from the side surface of the RFID unit. In contrast, according to the present embodiment, it is possible to efficiently manufacture an RFID unit which is configured to prevent reinforcing members or an antenna substrate from being exposed to the outside.

FIG. 15is a flowchart illustrating the outline of a process for manufacturing RFID units according to the third embodiment.

[Step S31] In the third embodiment, the same reinforcing members as used in the above-described general RFID tag-manufacturing process are used. First, the reinforcing members are mounted on protective sheet members, which serve as exteriors. At this time, sprocket holes for use in positioning in later process steps are formed in advance. The protective sheet members having the reinforcing members mounted thereon are taken up by respective rolls.

[Step S32] On the other hand, noncontact IC chips are mounted on the above-described antenna substrate, and the antenna substrate is cut in units of the IC chip and the antenna pattern, whereby RFID inlets are prepared.

[Step S33] The RFID inlets are mounted on a sheet member, which serves as an intermediate layer. At this time, sprocket holes for use in positioning in later process steps are formed in advance in the sheet member. The sheet member having the RFID inlets mounted thereon are taken up by a roll.

[Step S34] The protective sheet members that have the reinforcing members mounted thereon and are to form an uppermost layer and a lowermost layer, respectively, the sheet member having the RFID inlets mounted thereon, and a sheet member serving as a spacer are laminated one upon another, and are fixedly attached to each other. Further, the members fixedly attached are cut out in units of respective regions of the RFID tags, whereby RFID units are completed. In this process step, by pulling out all the sheet members from the respective rolls thereof at the same speed, it is possible to fixedly attach the sheet members to each other and then cut out the RFID units.

Next, a more detailed description will be given of the above-described process steps.

FIGS. 16A and 16Bexplain a reinforcing member-mounting/hole-machining process step.FIG. 16Ais a side view illustrating how this process step is carried out, andFIG. 16Bis a plan view illustrating the same.

The process step illustrated inFIGS. 16A and 16Bcorresponds to the step S31inFIG. 15. In this process step, a rubber sheet301, which is a protective sheet member, is provided in a state wound around a roll331. This protective sheet member forms the exterior of the RFID unit as a final product, and has the function of sealing the IC chip, the antenna pattern, the reinforcing members, and so forth, within each RFID unit. It suffices that this protective sheet member is made of the same material as that of the protective sheet members arranged on the nylon mesh201in the first embodiment.

In this process step, the rubber sheet301is pulled out from the roll331onto a stage332, and reinforcing members302of the IC chips are mounted on an upper surface of the rubber sheet301at predetermined space intervals P, by a mounting tool333. It suffices that as the reinforcing members302, there are used ones made of the same material and having the same shape as that of the reinforcing members104used in the aforementioned general RFID tag-manufacturing process. Further, in the present embodiment, an adhesive agent303is attached to a lower surface of each reinforcing member302. In the present embodiment, a double-faced tape is affixed as the adhesive agent303to the lower surface of the reinforcing member302, by way of example. The reinforcing members302as described above are conveyed to predetermined positions on the rubber sheet301and are pressed against the rubber sheet301, by the mounting tool333. Alternatively, after the adhesive agent303is attached to the rubber sheet301, the reinforcing member302may be affixed thereto.

Further, in this process step, positioning sprocket holes304are formed by a hole-making tool334at predetermined space intervals through the rubber sheet301. It suffices that the space intervals at which the sprocket holes304are formed are equal to space intervals P at which the reinforcing members302are mounted.

The rubber sheet301, which has the reinforcing members302mounted thereon and the sprocket holes304formed therethrough by the above process step, is taken up by a roll again. As this roll, there may be used the original roll331around which the rubber sheet301has been wound, or another roll provided on the side of the other end of the rubber sheet301.

FIGS. 17A and 17Bexplain an RFID inlet-preparing process step.FIG. 17Ais a side view illustrating how this process step is carried out, andFIG. 17Bis a plan view illustrating the same.

The process step illustrated inFIGS. 17A and 17Bcorresponds to the step S32inFIG. 15. In this process step, first, noncontact IC chips312are mounted on a antenna substrate311by the same procedure as employed in the IC chip-mounting process step in the general RFID tag-manufacturing process, described above with reference toFIGS. 3A and 3B. More specifically, as illustrated inFIGS. 17A and 17B, the antenna substrate311formed with antenna patterns313is pulled out from a roll341onto a stage342. Then, the IC chips312are mounted on the antenna substrate311e.g. by flip chip bonding using a bonding tool343, and terminals of the IC chips312are connected to associated ones of the antenna patterns313. The materials and shapes of the antenna substrate311and the antenna patterns313may be the same as employed in the above-described general RFID tag-manufacturing process.

Next, on the stage342, a region corresponding to a pair of one IC chip312and one antenna pattern313is punched by a punching die344along dotted lines inFIG. 17B, whereby a group of electronic components constituting an RFID tag is packaged, whereby the RFID inlet is prepared.

FIGS. 18A and 18Bexplain an RFID inlet-mounting/hole-machining process step.FIG. 18Ais a side view illustrating how this process step is carried out, andFIG. 18Bis a plan view illustrating the same.

The process step illustrated inFIGS. 18A and 18Bcorresponds to the step S33inFIG. 15. In this process step, first, the RFID inlets prepared in the step S32are mounted on a sheet member which serves as an intermediate layer of the RFID units. In the present embodiment, a rubber sheet321is used as the sheet member. It suffices that as the material of this sheet member, the same material as that of the protective sheet member serving as the exterior of the RFID unit may be used.

The rubber sheet321is provided in a state wound around a roll351. When the rubber sheet321is pulled out from the roll351onto a stage352, RFID inlets322are mounted on an upper surface of the rubber sheet321at predetermined space intervals, by a mounting tool353. In the present embodiment, the RFID inlets322are mounted on the rubber sheet321at the same space intervals as the space intervals P at which the reinforcing members302are mounted on the rubber sheet301in the step S31.

Further, in the present embodiment, an adhesive agent323is applied to a lower surface of each RFID inlet322. In the present embodiment, similarly to the process step in the step S31, a double-faced tape is affixed to the lower surface of the RFID inlet322as the adhesive agent323, by way of example. The RFID inlets322as described above are conveyed to predetermined positions on the rubber sheet321, pressed against the rubber sheet321, and affixed thereto, by the mounting tool353. Alternatively, after the adhesive agent323is attached to the rubber sheet321, the RFID inlets322may be affixed to the adhesive agent323.

Further, in this process step, positioning sprocket holes324are formed by a hole-making tool354at predetermined space intervals in the rubber sheet321. It is necessary that the space intervals at which the sprocket holes324are formed are made equal to the space intervals P at which the sprocket holes304are formed in the step S31. Further, space intervals at which the sprocket holes324are formed in the direction of the width of the rubber sheet321are also made equal to the space intervals at which the sprocket holes304are formed in the step S31.

The rubber sheet321having the RFID inlets322mounted thereon and the sprocket holes324formed therethrough by the above process step, is taken up by a roll again. At this time, since the RFID inlets322mounted on the rubber sheet321have a relatively small thickness, it is possible to wind the above-described rubber sheet321around a roll relatively easily. As this roll, there may be used the original roll351around which the rubber sheet321has been wound, or another roll provided on the side the other end of the rubber sheet321.

FIGS. 19A and 19Bexplain a sheet-attaching/unit-cutting process step.FIG. 19Ais a side view illustrating how this process step is carried out, andFIG. 19Bis a plan view illustrating the same.

The process step illustrated inFIGS. 19A and 19Bcorresponds to the step S34inFIG. 15. In this process step, a rubber sheet301ahaving the reinforcing members302mounted thereon in the step S31is laminated to a lower side of the rubber sheet321having the RFID inlets322mounted thereon in the step S33. Further, to an upper side of the rubber sheet321, a rubber sheet301bhaving the reinforcing members302mounted thereon in the step S31is laminated, with a spacer sheet330provided between the rubber sheet321and the rubber sheet301b.

Here, the rubber sheets301aand301bare arranged with the reinforcing members302mounted thereon facing inward, respectively. Further, the spacer sheet330is a sheet member formed of the same material as that of the rubber sheets301a,301band321. Let it be assumed that the spacer sheet330has sprocket holes formed at the same space intervals as the space intervals at which the sprocket holes are formed through the rubber sheets301a,301band321.

As illustrated inFIGS. 19A and 19B, the rubber sheets301a,301band321and the spacer sheet330are pulled out from rolls361a,361b,362and363, respectively, and are conveyed to a location between sprocket wheels364aand364b. The sprocket wheels364aand364bhave protrusions formed on outer peripheral surfaces thereof at the same space intervals, and the rubber sheets301a,301band321and the spacer sheet330are conveyed while the above protrusions are sequentially inserted into sprocket holes formed in the rubber sheets301a,301band321and the spacer sheet330, respectively. This positions the IC chips and the reinforcing members302such that the reinforcing members302mounted on the rubber sheets301aand301b, respectively, are accurately arranged above and below the IC chips mounted on the rubber sheet321.

Further, rollers365aand365bare provided on downstream sides of the respective sprocket wheels364aand364b, and the rubber sheets301a,301band321and the spacer sheet330are conveyed while being vertically pressurized by the rollers365aand365b. At this time, for example, the rubber sheets301a,301band321and the spacer sheet330are heated by the rollers365aand365bor by heat sources, not illustrated, other than the rollers365aand365b. This causes the adjacent sheets to be fixedly attached to each other by thermocompression bonding, whereby the RFID inlets322and the reinforcing members302are sealed.

Further, the sheets laminated one upon another, particularly the rubber sheet321and the spacer sheet330have elastic properties, and hence when the sheet members are heated by the rollers365aand365b, regions of the respective sheet members, brought into contact with the RFID inlets322and the reinforcing members302, are contracted only by the heights of the RFID inlets105and the reinforcing members302. This holds the upper surface of the whole sheet laminate approximately flat. To make flat the upper surface of the sheet laminate, e.g. recesses may be formed in advance in the rubber sheet321and the spacer sheet330in accordance with the shapes of the RFID inlets322and the reinforcing members302.

The sheet members thermocompression-bonded to each other as described above are cut out on a stage366by a punching die367in units of regions each including one RFID inlet105. The units cut out in this process step become RFID units, which are final products. InFIG. 19B, the region cut out by the punching die367is indicated as a cut-out region370. Each cut-out region370is configured to be larger in area than the region of the RFID inlet105and the reinforcing members302associated therewith, whereby the RFID inlet105and the reinforcing member302are completely sealed with the upper and lower sheet members.

Although in the present embodiment, the sprocket holes are provided in the respective sheet members so as to position the RFID inlets105and the reinforcing members302during lamination of the sheet members, this is not limitative, but instead of such hole-like members, positioning cutouts may be provided in the lateral side portions of the sheet members. In this case, it suffices that in the lamination process step, the sheet members are conveyed with members, which correspond to the protrusions of the sprocket wheels, engaged with the cutouts of the sheet members. Further, any other suitable positioning method may be employed.

In the examples illustrated inFIGS. 19A and 19B, all of the rubber sheets301a,301band321and the spacer sheet330are laminated one upon another at a time. However, a procedure may be employed in which adjacent ones of the sheet members are laminated in advance, and e.g. after taking up the sheet laminates by respective rolls, all the sheet members are finally laminated one upon another. In this case, the sheet members may be fixedly attached each time the adjacent ones of the sheet members are laminated one upon another, when the final lamination process step is executed.

FIGS. 20A and 20Billustrate an RFID unit prepared according to a third embodiment.FIG. 20Ais a plan view illustrating the same, andFIG. 20Bis a side view illustrating the same.

Referring toFIGS. 20A and 20B, in the RFID unit prepared in the present embodiment, the reinforcing members302are disposed above and below the IC chip312mounted on the RFID inlet105, respectively. Now, a hard material can be used for the reinforcing member302, as described hereinabove, so that it is possible to enhance the strength of the RFID unit compared with the case where a mesh-like material is used as in the second embodiment.

Further, the IC chip312, the antenna pattern313and the antenna substrate311are all sealed within protective sheet members such that they are not exposed from the outer surfaces of the RFID unit. As a consequence, even when a liquid or a chemical is attached to the RFID unit, it is possible to prevent the liquid or the chemical from touching the IC chip312and the antenna pattern313within the RFID unit, thereby making it possible to cause the IC chip312to normally operate. Further, since the reinforcing members302as well are completely sealed within the protective sheet members, it is also possible to prevent the reinforcing members302from being corroded.

According to the above-described third embodiment, it is possible to manufacture the RFID units from start to finish, by using rolls. Further, since a material that can be thermocompression-bonded is used for the protective sheet members, it is possible to efficiently carry out the process step for laminating the protective sheet members and fixedly attaching the same. Furthermore, the positioning holes are formed through the laminated protective sheet members, whereby when the protective sheet members are laminated and fixedly attached to each other, it is possible to easily position the IC chips and the reinforcing members. This makes it possible to mass-produce the RFID units having the above-mentioned features, at low costs.

Although in the above-described third embodiment, the reinforcing members302are arranged above and below the IC chip312, the RFID unit may be configured such that the reinforcing member302is disposed only above the IC chip312. In this case, it suffices that in the sheet-attaching process step illustrated inFIGS. 19A and 19B, the arranging and fixedly attaching of the rubber sheet301abelow the IC chip312is omitted. That is, in this case, the rubber sheet321functions as a protective sheet, as an exterior, which protects the RFID inlet322.

Fourth Embodiment

In the fourth embodiment, part of the manufacturing process according to the second embodiment is replaced by part based on another method. More specifically, the method of forming slits in the antenna substrate having IC chips mounted thereon for fixedly attaching the protective sheet members to each other is replaced by a method of mounting RFID inlets, each of which includes one IC chip and an antenna substrate, on an intermediate protective sheet member, thereby making it possible to fixedly attach the protective sheet members to each other.

FIG. 21is a flowchart illustrating the outline of a process for manufacturing RFID units according to the fourth embodiment.

[Step S41] In this process step, the same method as employed in the step S21inFIG. 9is used to prepare a sheet laminate by sandwiching a mesh-like reinforcing member between protective sheet members. The prepared sheet laminate is taken up by a roll.

[Step S42] Separately from the step S41for the above-described sheet laminate, a process step for mounting IC chips on a sheet member is performed. First, by the same method as employed in the steps S22and S23inFIG. 9, an antenna substrate formed with antenna patterns is prepared, and the IC chips are mounted on the antenna substrate.

[Step S43] A base sheet member is disposed on the antenna substrate having the IC chips mounted thereon. In this process step, the base sheet member having an adhesive agent attached thereto is fixedly attached to a lower surface of the antenna substrate, i.e. a surface of the antenna substrate where no IC chips are mounted.

[Step S44] Regions each including one IC chip and one antenna pattern connected thereto are punched from the protective sheet member whereby RFID inlets are prepared. In this process step, out of the laminated members, only the antenna substrate and a layer of the adhesive agent as a layer under the antenna substrate, are cut, and the antenna substrate except for the regions thereof corresponding to the RFID inlets is peeled off. Thus, a protective sheet member having only the RFID inlets mounted thereon is produced, and taken up by a roll.

[Step S45] The same method as employed in the step S25inFIG. 9is employed to sandwich the base sheet member having the RFID inlets mounted thereon between the sheet laminates prepared in the step S41on the opposite sides thereof, whereby the adjacent sheet members are fixedly attached to each other. Further, the members fixedly attached are cut out in units of regions each including a RFID tag, whereby RFID units are completed.

Next, a more detailed description will be given of the above-described process steps.

First, the process step in the step S41is the same as described above with reference toFIGS. 10A and 10B. Further, the process step in the step S42is the same as the IC chip-mounting process step in the general RFID tag-manufacturing process, described above with reference toFIGS. 3A and 3B. Therefore, illustrations of these process steps are omitted.

The process step illustrated inFIG. 22corresponds to the step S43inFIG. 21. Referring toFIG. 22, IC chips402are mounted on an antenna substrate401in the step S42, and the antenna substrate401is subjected to theFIG. 22process step in a state wound around a roll431. On the other hand, a rubber sheet412having one surface coated with an adhesive agent411is taken up by a roll432. The rubber sheet412is wound around the roll432in a state in which a release paper413is affixed to a surface of the adhesive agent411. This rubber sheet412is a sheet member which functions as a base substrate for mounting RFID inlets, and is made of the same material as that of the protective sheet member used in the step S41.

As illustrated inFIG. 22, the antenna substrate401and the rubber sheet412are pulled out from the rolls431and432, respectively, and are conveyed to a location between rollers433aand433b. At this time, the release paper413affixed to the rubber sheet412is removed from the rubber sheet412, and is taken up by a roller434. Thus, a surface of the adhesive agent411of the rubber sheet412is brought into contact with the antenna substrate401, whereby the rubber sheet412and the antenna substrate401are pressure-bonded to each other by the pressure between the rollers433aand433b. The rubber sheet412and the antenna substrate401pressure-bonded to each other are conveyed to a stage435, and subjected to the next process step without being taken up by a roller.

It is desirable that the roller433athat is brought into contact with the antenna substrate401is made of a material soft enough not to damage the IC chips402with its pressure.

FIGS. 23A and 23Bexplain an RFID inlet-punching process step.FIG. 23Ais a side view illustrating how this process step is carried out, andFIG. 23Bis a plan view illustrating the same.

The process step illustrated inFIGS. 23A and 23Bcorresponds to the step S44inFIG. 21. The rubber sheet412and the antenna substrate401pressure-bonded by the above-described process step are subjected to the punching process step on the stage435. In this process step, only the antenna substrate401and the layer of the adhesive agent411coated on the rubber sheet412are cut by a punching die436, but the rubber sheet412is not cut.

After that, at the location of a roller437, a portion of the antenna substrate401, outside regions thereof cut by the punching die436, is peeled off the rubber sheet412, and is taken up e.g. by a roll438. On the other hand, the rubber sheet412is taken up by a roll439.

The region of the antenna substrate401, cut by the punching die436, is indicated by dotted lines in FIG.23B. As illustrated inFIG. 23B, a region corresponding to a pair of the IC chip402and an antenna pattern403is cut by the punching die436. Therefore, when only the outside of the regions cut by the punching die436is peeled off the rubber sheet412, in the rubber sheet412taken up by the roll439, only regions each including the IC chip402and the antenna pattern403remain affixed. That is, on this rubber sheet412, RFID inlets404each having a group of electronic components constituting an RFID tag packaged therein are prepared.

The rubber sheet412to which the RFID inlets404prepared at this time are affixed has approximately the same configuration as that of the rubber sheet prepared in the RFID inlet-mounting process step (step S33inFIG. 15) in the third embodiment. In the present embodiment, however, no sprocket holes are formed.

FIGS. 24A and 24Bexplain a sheet-attaching/unit-cutting process step.FIG. 24Ais a side view illustrating how this process step is carried out, andFIG. 24Bis a plan view illustrating the same.

The process step illustrated inFIGS. 24A and 24Bcorresponds to the step S45inFIG. 21. The basic procedure employed in this process step is approximately the same as that employed in the sheet-attaching/unit-cutting process step in the step S25inFIGS. 10A and 10B. Further, since the process step has been described with reference toFIGS. 12A and 12B, inFIGS. 24A and 24B, component parts and elements which are identical to those appearing inFIGS. 12A and 12Bare denoted by identical reference numerals.

The process step illustrated inFIGS. 24A and 24Bemploys the rubber sheet412provided with the RFID inlets404that are prepared in the steps S42to S44inFIG. 21, in place of the antenna substrate203illustrated inFIGS. 12A and 12B. That is, the rubber sheet412and the sheet laminates206aand206bare pulled out from rolls439,242aand242b, respectively, and are conveyed while being vertically pressurized by the rollers243aand243b. In accordance therewith, heat is applied e.g. by the rollers243aand243b, or from a heat source, not illustrated, other than the rollers243aand243b.

Thus, a rubber sheet as a lower layer of the sheet laminate206aand an upper surface of the rubber sheet412are thermocompression-bonded to each other, whereby the IC chips402and the antenna patterns403are sealed with the rubber sheets. Further, a rubber sheet as an upper layer of the sheet laminate206band a lower surface of the rubber sheet412are also thermocompression-bonded to each other. Then, similarly to the second embodiment, the two rubber sheets within each of the sheet laminates206aand206bare also thermocompression-bonded to each other.

When all the above sheet members are pressure-bonded, the sheet laminate206ais contracted according to the height of the RFID inlet404, and therefore the upper surface of the sheet laminate206ais held approximately flat. To make flat the upper surface of the sheet laminate206a, e.g. recesses may be formed in advance in the rubber sheet e.g. according to the shape of each RFID inlet404. However, in this case, in the process step for fixedly attaching the sheet laminates206aand206bthat have the rubber sheet412therebetween, it is necessary to position the recesses on the sheet laminate206ato the locations of the RFID inlet404.

The sheet members thermocompression-bonded to each other as described above are cut out by the punching die244in units of regions each including one RFID inlet404. The units cut out in this process step become RFID units, which are final products. InFIG. 24B, the region cut out by the punching die244is indicated as a cut-out region405.

In the present embodiment, the sheet laminates206aand206bprepared in advance in the step S41are subjected to the step S45. However, for example, in the step S45, the laminating and fixedly attaching of the sheet laminates206aand206bmay be performed simultaneously with the laminating and fixedly attaching of the sheet laminates206aand206band the rubber sheet412.

Further, in the process step illustrated inFIGS. 24A and 24B, out of the sheet laminates206aand206b, as for the sheet laminate206bfixedly attached to the lower surface of the rubber sheet412, a rubber sheet thereof toward the rubber sheet412may be omitted such that the nylon mesh is brought into direct contact with the rubber sheet412. However, by employing such a process step as illustrated inFIGS. 24A and 24B, it is possible to use the sheet laminates206aand206bmanufactured for the opposite surfaces of the rubber sheet412by quite the same manufacturing process step, which makes it possible to simplify the manufacturing process step.

FIGS. 25A and 25Billustrate an RFID unit prepared according to the fourth embodiment.FIG. 25Ais a plan view illustrating the same, andFIG. 25Bis a side view thereof.

Referring toFIGS. 25A and 25B, in the RFID unit prepared in the present embodiment, similarly to the second embodiment, layers of the nylon mesh201are formed above and below the IC chips402. This protects the IC chips402from external forces. Further, similarly to the second embodiment, end faces of the nylon mesh201are exposed from side surfaces of the RFID unit.

Further, in the RFID unit, the RFID inlet404including the IC chip402and the antenna patterns403is completely sealed with rubber sheets as protective members. That is, differently from the second embodiment, the whole antenna substrate401included in the RFID inlet404is sealed with the rubber sheets. This makes it possible to more firmly protect the IC chip205even when a liquid or a chemical is attached to the RFID unit.

According to the above-described fourth embodiment, a rubber sheet provided with an adhesive agent is used as a base sheet member of the RFID inlet, whereby it is unnecessary to cut off the RFID inlet once from a sheet member that can be taken up by a roll. This makes it possible to employ the manufacturing method which uses rolls from start to finish in the process for manufacturing the RFID units. Moreover, it is possible to manufacture RFID units which are configured such that RFID inlets therein are completely sealed with protective sheet members. This makes it possible to mass-produce RFID units, which resistant to external forces, liquids, and chemicals, at low costs.

Although in the above-described fourth embodiment, the nylon meshes201as reinforcing members are arranged above and below the IC chip402, the nylon mesh201may be disposed only above the IC chip402, for example. In this case, in the sheet-attaching process step illustrated inFIGS. 24A and 24B, the arranging and fixedly attaching of the sheet laminate206bbelow the IC chip402are omitted. However, as described above with reference toFIGS. 14A and 14B, to ensure strength against a bending force, it is desirable to arrange the nylon meshes201both above and below the IC chip402.

Fifth Embodiment

In the fifth embodiment, part of the manufacturing process according to the third embodiment is replaced by the process for manufacturing RFID inlets, according to the fourth embodiment.

FIG. 26is a flowchart illustrating the outline of an RFID unit-manufacturing process according to the fifth embodiment.

[Step S51] In this process step, by the same method as employed in the step S31inFIG. 15, a hard reinforcing member is mounted on a protective sheet member, and positioning sprocket holes are formed. The protective sheet member having the reinforcing member mounted thereon is taken up by a roll.

[Steps S52to S54] In these process steps, by the same method as employed in the steps S42to S44inFIG. 21, a protective sheet member provided with the RFID inlets is prepared. However, differently from the above method, in the step S54, a process step for forming sprocket holes in the protective sheet member is added.

[Step S55] By the same method as employed in the step S34inFIG. 15, the protective sheet member provided with the RFID inlets, the protective sheet members each having the reinforcing member mounted therein, for forming the upper most layer and the lowermost layer, and a sheet member as a spacer are laminated one upon another, and are fixedly attached to each other. Further, the members fixedly attached are cut out in units of regions each including an RFID tag, whereby RFID units are completed.

Next, a more detailed description will be given of the above-described process steps.

First, the process step in the step S51is the same as described above with reference toFIGS. 16A and 16B. Further, the process step in the step S52is the same as the IC chip-mounting process step in the general RFID tag-manufacturing process, described above with reference toFIGS. 3A and 3B. Furthermore, the process step in the step S53is the same as described above with reference toFIG. 22. Therefore, illustrations of these process steps are omitted.

FIGS. 27A and 27Bexplain a hole-machining/RFID inlet-punching process step.FIG. 27Ais a side view illustrating how this process step is carried out, andFIG. 27Bis a plan view illustrating the same.

The process step illustrated inFIGS. 27A and 27Bcorresponds to the step S54inFIG. 26. The basic procedure of this process step is approximately the same as the procedure of the RFID inlet-punching process step illustrated in the step S44inFIG. 21. Further, this process step has also already been described with reference toFIGS. 23A and 23B, and hence inFIGS. 27A and 27B, component parts and elements which are identical to the component parts and elements appearing inFIGS. 23A and 23Bare denoted by identical reference numerals. However, an antenna substrate401a, a rubber sheet412aand a roll439ainFIGS. 27A and 27Bcorrespond to the antenna substrate401, the rubber sheet412and the roll439inFIGS. 23A and 23B, respectively.

The process step illustrated inFIGS. 27A and 27Bis obtained by adding a process step for forming sprocket holes501to the process step described above with reference toFIGS. 23A and 23B. The sprocket holes501are formed by a hole-making tool511at predetermined space intervals in the antenna substrate401aand the rubber sheet412a. Now, the space intervals at which the sprocket holes501are formed are the same as the space intervals at which the sprocket holes are formed in the step S51. The process step for forming the sprocket holes501is not limitatively performed before the process step for cutting the antenna substrate401aby the punching die436but it may be performed after the cutting process step. For example, after removing an unwanted region of the antenna substrate401afrom the rubber sheet412a, the sprocket holes501may be formed through the rubber sheet412a.

By carrying out the above process steps, the rubber sheet412ataken up by the roll439ahas only regions affixed thereto each of which include the IC chip402and the antenna pattern403. That is, on this rubber sheet412a, there are formed the RFID inlets404in each of which a group of electronic components constituting an RFID tag are packaged. The rubber sheet412ato which the RFID inlets404formed at this time are affixed has approximately the same configuration as that of the rubber sheet prepared in the RFID inlet-mounting process step (step S33inFIG. 15) in the third embodiment.

FIGS. 28A and 28Bexplain a sheet-attaching/unit-cutting process step.FIG. 28Ais a side view illustrating how this process step is carried out, andFIG. 28Bis a plan view illustrating the same.

The process step illustrated inFIGS. 28A and 28Bcorresponds to the step S55inFIG. 26. The basic procedure employed in this process step is the same as that employed in the sheet-attaching/unit-cutting process step in the step S34inFIG. 15in the third embodiment. Further, since the process step has been described with reference toFIGS. 19A and 19B, inFIGS. 28A and 28B, component parts and elements which are identical to those appearing inFIGS. 19A and 19Bare denoted by identical reference numerals.

The process step illustrated inFIGS. 28A and 28Bemploys the rubber sheet412aprovided with the RFID inlet404that is prepared in the step S54inFIG. 26, in place of the rubber sheet321provided with the RFID inlet322illustrated inFIGS. 19A and 19B. The rubber sheet412ais pulled out from the roll439, and is conveyed by the sprocket wheels364aand364b. The rubber sheet412a, the rubber sheets301aand301bas the lower layer and the upper layer, and the spacer sheet330are laminated one upon another, and are thermocompression-bonded to each other.

When all the above sheet members are pressure-bonded, the spacer sheet330is contracted according to the height of the RFID inlet404, whereby the upper surface of the sheet laminate is held approximately flat. To make flat the upper surface of the sheet laminate, e.g. recesses may be formed in advance in the spacer sheet330according to the shape of the RFID inlet404.

The sheet members thermocompression-bonded to each other as described above are cut out on the stage366by the punching die367in units of regions each including one RFID inlet404. The units cut out in this process step become RFID units, which are final products. InFIG. 28B, the region cut out by the punching die367is indicated as a cut-out region370. The cut-out region370is configured to be larger in area than the region of the RFID inlet404and the reinforcing members302associated therewith, whereby the RFID inlet404and the reinforcing members302are completely sealed with the upper and lower sheet members.

Although in the present embodiment, the sprocket holes are provided through the respective sheet members so as to position the RFID inlets404and the reinforcing members302during lamination of the sheet members, this is not limitative, but similarly to the above-described third embodiment, instead of such hole-like members, positioning cutouts may be provided in the lateral side portions of the sheet members. Further, any other positioning suitable method may be employed.

In the examples illustrated inFIGS. 28A and 28B, all of the rubber sheets301a,301band412aand the spacer sheet330are laminated one upon another at a time. However, a procedure may be employed in which adjacent ones of the sheet members are laminated in advance, and e.g. after taking up the sheet laminates by respective rolls, all the sheet members are finally laminated one upon another. In this case, the sheet members may be fixedly attached each time the adjacent ones of the sheet members are laminated one upon another or which a final lamination process step is executed.

FIGS. 29A and 29Billustrate an RFID unit prepared according to the fifth embodiment.FIG. 29Ais a plan view of the RFID unit, whereasFIG. 29Bis a side view of thereof. InFIGS. 29A and 29B, component parts and elements which are identical to those appearing inFIGS. 20A and 20Bare denoted by identical reference numerals.

Referring toFIGS. 29A and 29B, the RFID unit prepared in the present embodiment has approximately the same configuration as that of the RFID unit prepared in the third embodiment and illustrated inFIGS. 20A and 20B. That is, the reinforcing members302are arranged above and below the IC chip402mounted on the RFID inlet404, respectively. Further, the IC chip402, the antenna patterns403, the antenna substrate401and the reinforcing members302are all sealed within the protective sheet member, and are prevented from being exposed from the RFID unit.

According to the above-described fifth embodiment, it is possible to more efficiently manufacture the RFID units having the same features as those of the RFID unit made in the third embodiment. More specifically, in the fifth embodiment, a rubber sheet provided with an adhesive agent is used as a base sheet member for the RFID inlets, whereby it is unnecessary to cut off the RFID inlets once from a sheet member that can be taken up by a roll. This makes it possible to employ the manufacturing method which uses rolls from start to finish in the RFID unit-manufacturing process.

Although in the above-described fifth embodiment, the reinforcing members302are arranged above and below each IC chip, similarly to the above-described third embodiment, the reinforcing member302may be disposed only above the IC chip, for example. In this case, it is possible that in the sheet-attaching process step illustrated inFIGS. 28A and 28B, the arranging and fixedly attaching of the lower rubber sheet301aare omitted.

Further, in the above-described second to fifth embodiments, in the respective sheet-attaching process steps in the step S25inFIGS. 6A and 6B, the step S34inFIG. 15, the step S45inFIG. 21, and the step S55inFIG. 26, the sheet members may be fixedly attached by using e.g. ultrasonic waves, in place of by thermocompression bonding. Alternatively, the sheet members may be fixedly attached by using an adhesive agent. However, when the adhesive agent is used, a process step for applying the adhesive agent to required surfaces of the antenna substrate or the sheet member is necessitated. In contrast, if a method using no adhesive agent is used, as in the above-described embodiments, it is possible to fixedly attach a plurality of sheet members at a time, which makes it possible to enhance manufacturing efficiency. Further, if the method of fixedly attaching sheet members directly to each other without using any adhesive agent, sheet members in layers become difficult to be peeled off, thereby making it possible to seal the inside of each RFID unit more positively. Furthermore, whichever attaching method may be used, it is desirable to pressurize sheet members such that the surface of a sheet laminate is made flat.

As described hereinabove, since a circuit chip and reinforcing members are arranged in respective different sheet members, the bending resistances of the respective sheet members becomes lower than when the circuit chip and the reinforcing members are mounted on the same sheet member, which makes it possible to take up the sheet members. Further, at the stage where the above sheet members are laminated one upon another, there are formed RFID tags in a final form before being cut out. Therefore, it is possible to cut out final products in this state, and hence the sheet member laminate is not wound around a roll in a state in which both the circuit chips and the reinforcing members are mounted thereon.