JP4080606B2 - Wireless information storage medium manufacturing method and wireless information storage medium manufactured by the manufacturing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to, for example, a wireless information storage medium thus be manufactured in the production process and this method of manufacturing a suitable wireless information storage medium as an article form used for performing predetermined information processing with respect to the article.
[0002]
[Prior art]
Next-generation information is a card-like wireless information storage medium that performs control to read information written to the information storage component or control writing information to the information storage component by communicating with the information storage component wirelessly via an antenna. It is attracting attention as a career.
[0003]
For example, IC chips can be used as stand-alone RFID tags attached to articles and used in shoplifting prevention systems, as ski lift tickets at ski resorts, and as pass cards for wireless processing automatic ticket gate systems. Yes.
[0004]
Such a card-shaped wireless information storage medium (hereinafter referred to as a card antenna) includes a module substrate on which an information storage component, which is an electronic component, is mounted, and a coil-shaped antenna (hereinafter referred to as an antenna coil) attached to the module substrate. Called).
[0005]
In particular, the antenna coil uses a three-layered conductor wire in which a metal wire material such as copper is covered with an insulating layer such as a polyimide material, and the outside is covered with an adhesive layer. The conductive wire is wound around a heated bobbin that is a mold to melt the adhesive layer on the surface, and the conductive wires are changed into a welded state before being cooled and solidified.
[0006]
Then, the antenna coil is sandwiched between the information storage component and the module substrate with a vinyl chloride sheet and hot pressed to obtain a card antenna. Therefore, the antenna coil is wound in parallel with the card surface.
[0007]
[Problems to be solved by the invention]
By the way, as shown in FIG. 8, the conventional molded card antenna has irregularities on the card surface a and the flatness is impaired. Therefore, when printing on the card surface a, there is an adverse effect such as distortion of the printed image.
[0008]
As a cause, the characteristic of the conducting wire c which comprises the antenna coil b, and its winding shape can be considered.
That is, the conductive wire c is wound in parallel to the card surface a while a so-called high-temperature welding wire is used in which the melting temperature of the adhesive layer covering the surface is set higher than the heating temperature at the time of hot pressing. Overall, it has a rectangular cross section.
[0009]
Therefore, even if the antenna coil b portion is heated during hot press processing, the adhesive layer does not melt, and even when an external force is applied, it does not lose its shape and maintains the wound state. On the other hand, the portion other than the antenna coil b is heated and pressurized and thinly extended.
[0010]
Eventually, the surface of the obtained card antenna D becomes uneven. In addition, since the antenna coil b is wound in parallel with the card surface a, if an external force such as bending is applied during use, the antenna coil b is difficult to absorb and may be deformed.
[0011]
In addition, the conducting wire c may be a conducting wire having a rectangular cross section as well as a circular cross section. In this case, since there is no gap in the wound state, there is a problem that if the molded card antenna is bent, wrinkles are likely to occur on the surface of the antenna coil portion.
[0012]
The present invention has been made on the basis of the above circumstances, and its purpose is to prevent the occurrence of surface irregularities to improve flatness, to withstand external forces of bending during use, and to prevent wrinkles. An object of the present invention is to provide a highly reliable wireless information storage medium that does not occur and a method for manufacturing the same.
[0013]
[Means for Solving the Problems]
In order to solve the above problems, the invention described in claim 1 is characterized in that a low-temperature welding line whose surface is covered with an adhesive layer that melts at a temperature lower than the heating temperature at the time of hot pressing is gradually thinned from the outer peripheral portion toward the central portion. A coil process for obtaining an antenna coil by winding it in a shape in which the central part is constricted, a sheet process for applying sheets to both sides of the antenna coil, and bonding the above-mentioned conductors by pressing and heating the sheet from both sides The layer is melted, and the thickness of the antenna coil is reduced, and a hot pressing step for integrating with the sheet is provided .
[0019]
According to the present invention, it is possible to prevent unevenness on the surface and improve the flatness, to withstand the external force of bending during use, and to be formed without wrinkling.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a configuration of a card-like wireless information storage medium (hereinafter referred to as a card antenna).
[0021]
In the figure, reference numeral 1 denotes a module substrate, on which an information storage component 2 which is an electronic component composed of an LSI, a chip capacitor, and the like, and a coiled antenna (hereinafter referred to as an antenna coil) 3 are mounted. These both surfaces are covered with a vinyl chloride sheet not shown here.
[0022]
The information storage component 2 and the antenna coil 3 are electrically connected, and the antenna coil 3 transmits and receives signals without contact with an external device. The information storage component 2 receives a signal from the antenna coil 3 and sends a necessary information processing signal to an external device via the antenna coil 3.
[0023]
Hereinafter, the antenna coil 3 will be described in detail.
The antenna coil 3 is formed using the conducting wire 4 shown in FIG. That is, there is a metal wire material 5 such as copper as a core material, and this metal wire material 5 is covered with an insulating layer 6 such as a urethane material or a polyimide material, and further this outer side is covered with an adhesive layer 7 to form a three-layer structure.
[0024]
The adhesive layer 7 is made of a material that melts at a lower temperature (155 ° C.) than a heating temperature (160 ° C.) at the time of hot press processing, which will be described later, and a so-called low-temperature welding wire is used as the conductive wire 4.
[0025]
In order to form a card antenna, it is necessary to perform the following steps.
First, as a coil process, the conductive wire 4 is tightly wound around a heated bobbin that is a mold and heated for a predetermined time. The adhesive layer 7 on the surface is melted to some extent, and the contact portions of the conductive wires 4 are welded to each other.
[0026]
And a bobbin is extracted from the wound conducting wire 4, and cooling by leaving is made. The wound conducting wire 4 is solidified to obtain an antenna formed into a coil shape, that is, the antenna coil 3.
[0027]
FIG. 3 shows a cross section of the antenna coil 3 portion of the molded card antenna 10. For convenience of explanation, the module substrate and the information storage component described above are omitted.
[0028]
Next, as a sheet process, for example, the surface sheet 8 on which the printed white PVC sheet 8a (thickness 100 μm) and the transparent PVC sheet 8b (thickness 50 μm) are bonded together is used for the antenna coil 3 and the spacer 9. Put it on both sides.
[0029]
Thereafter, a hot press process is performed.
As described above, during hot pressing, press bonding is performed at 160 ° C., whereas the adhesive layer 7 on the surface of the conductor 4 constituting the antenna coil 3 is a low-temperature welding wire that melts at 155 ° C. The adhesive layer 7 between the conductors 4 solidified at the time of molding is melted again, and the binding between the conductors 4 is once loosened.
[0030]
As shown in FIG. 4A, since the antenna coil conductor 4 has a circular cross section, a gap 11 is formed between the conductors 4 even when a plurality of windings are wound. In this state, hot pressing is performed and external force is received from both sides.
[0031]
As shown in FIG. 4 (B), the antenna coil conductor 4 that has received an external force due to press pressing is crushed in the pressing direction and deformed to a certain degree of flatness, and the gap 11 between the conductors 4 has been reduced. Remain in state.
[0032]
Since the antenna coil 3 is configured by winding the conducting wire 4 having a low-temperature welding wire and a circular cross section, the gap 11 absorbs the press external force at the time of pressing and does not affect the card surface 12. .
[0033]
If the above hot pressing process is completed and natural cooling is performed by leaving the card, the card antenna 10 in which the antenna coil 3 and the surface sheet 8 are integrated is obtained.
In this way, the card antenna 10 which is thinner than the conventional card antenna can be molded, and the surface 12 is not uneven, and high flatness is obtained and the printability is good.
[0034]
Since the molded antenna coil 3 extends thinly while being crushed during the hot pressing process, no stress is left inside.
The gap 11 of the antenna coil 3 remains as it is. Therefore, even when an external bending force is applied to the card antenna 10 during actual use, the external force is absorbed by bending deformation for the gap 11.
[0035]
That is, the obtained card antenna 10 has characteristics such as being strong against bending external force during actual use and having a characteristic that it is difficult to break, and that there is no generation of wrinkles on the surface.
[0036]
In addition, if the antenna coil is thinly formed from the beginning, warping or the like tends to occur by itself. However, since the antenna coil 3 formed here is initially thick, it is handled from the coil process to the sheet process. Alternatively, when handling from the sheet process to the hot press process, it is easy to work and advantageous.
[0037]
FIG. 5 shows a state of a coil process in which a bobbin 20 having a cross-sectional shape inclined toward the central axis is prepared, and a conductive wire 4 is wound around the bobbin 20 to form an antenna coil 3A.
The molded antenna coil 3A gradually becomes thinner from the outer periphery toward the center according to the shape of the bobbin 20, and has a shape in which the center is constricted.
[0038]
FIG. 6 shows an example of a card antenna 10A formed through a sheet process and a hot press process using the antenna coil 3A previously formed in the coil process shown in FIG.
[0039]
Also here, the conductive wire 4 constituting the antenna coil 3A employs a low-temperature welding wire in which the melting temperature of the adhesive layer covering the surface is lower than the heating temperature at the time of hot pressing.
[0040]
In the case of the antenna coil 3A using the conductive wire 4 of such a low temperature welding wire, the adhesive layer of the conductive wire 4 is melted by the influence of the heating temperature at the time of hot pressing, and the gap 11 between the conductive wires is reduced. As described above.
[0041]
In addition, the antenna coil 3A is gradually thinned from the outer peripheral portion toward the central portion in the coil process, and is crushed as a whole by receiving a press external force from a shape in which the central portion is constricted.
[0042]
Eventually, the antenna coil 3A is thinly crushed, and a card antenna 10A having a thinner thickness is obtained.
FIG. 7 is an example of a card antenna 10B formed through a sheet process and a hot press process using the antenna coil 3A previously formed in the coil process shown in FIG.
[0043]
However, here, a high-temperature welding wire in which the melting temperature of the adhesive layer covering the surface is higher than the heating temperature at the time of hot pressing is adopted as the conductive wire 4a constituting the antenna coil 3A.
[0044]
In the case of the antenna coil 3B formed using such a high-temperature welding wire 4a, the adhesive layer does not melt at the heating temperature at the time of hot press processing.
[0045]
The molded card antenna 10B has a thickness dimension that is almost the same as the thickness of the antenna coil 3A.
However, since the antenna coil 3A has a shape in which the central portion is constricted in the coil process, only the outer peripheral portion substantially receives the press external force, and the card surface 12 can be hardly uneven.
[0046]
Since the gap 11 between the conductors 4a in the antenna coil 3A remains as it is, even if an external force of bending is applied to the card antenna 10B during actual use, the external force is absorbed by bending deformation by the amount of the gap 11 described above.
[0047]
That is, the obtained card antenna 10B has characteristics such as being strong against bending external force during actual use and having a characteristic that it is difficult to break, and the surface is free from wrinkles.
[0048]
【The invention's effect】
As described above, according to the present invention, it is possible to improve the flatness by preventing the occurrence of unevenness on the surface, and to improve the reliability withstanding the external force of bending during use and without the occurrence of wrinkles. There is an effect.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a card antenna according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view of a conductor constituting an antenna coil, showing an embodiment of the present invention.
FIG. 3 is a cross-sectional view of a card antenna showing an embodiment of the present invention.
FIGS. 4A and 4B are diagrams for explaining a change in an antenna coil during and after a hot press process according to an embodiment of the present invention. FIGS.
FIG. 5 is a cross-sectional view of a bopin and an antenna coil formed by being wound around the bobbin according to an embodiment of the present invention.
FIG. 6 is a cross-sectional view of a card antenna showing an embodiment of the present invention.
FIG. 7 is a cross-sectional view of a card antenna showing an embodiment of the present invention.
FIG. 8 is a cross-sectional view of a card antenna showing a conventional configuration.
[Explanation of symbols]
2 Information storage component,
4, 4a ... Lead wire,
3, 3A ... Antenna coil,
8 ... surface sheet,
7: Adhesive layer.

Claims (3)

The antenna coil is wound by winding a low-temperature welding wire whose surface is covered with an adhesive layer that melts at a temperature lower than the heating temperature during hot pressing, gradually thinning from the outer periphery toward the center, and constricting the center. A coiling process to obtain ;
A sheet process for applying sheets to both sides of the antenna coil ;
A hot pressing step of pressing and heating the sheet from both sides to melt the adhesive layer of the conducting wire, reducing the thickness of the antenna coil and integrating with the sheet ;
A method of manufacturing a wireless information storage medium, comprising: An information storage medium manufactured by the manufacturing method according to claim 1 . The wireless information storage medium according to claim 2 , wherein the conducting wire has a circular cross section .

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