JP4043842B2 - Non-contact IC card - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a non-contact IC card including an antenna sheet.
In particular, in a non-contact IC card manufactured by press laminating a plurality of sheets including an antenna sheet, the present invention relates to a non-contact IC card excellent in smoothness and appearance quality and a substrate used for the manufacture.
Therefore, the application field of the present invention relates to the manufacture and application field of non-contact IC cards.
[0002]
[Prior art]
The non-contact IC card includes an antenna sheet (generally referred to as “inlay”) in which a coil is formed inside the card in order to obtain electric power and signals from the outside in a non-contact manner based on the principle of electromagnetic induction. An IC chip that processes and stores signals to be transmitted / received is connected to a coil and used as an integral part of an antenna sheet, or an IC module with a substrate is mounted on the card surface, and the IC module and antenna sheet are connected. There is a case to do.
In the former case, since the IC chip (which may be modularized) and the coil antenna are both embedded in the card base, the surface smoothness is particularly likely to deteriorate.
The base material of the conventional non-contact IC card is manufactured by press-laminating PVC or PET or PET-G, or by bonding with an adhesive sheet, but in order to improve smoothness, Attempts have been made to absorb irregularities on the card surface caused by IC chips and coil antennas by foaming an adhesive sheet.
[0003]
For example, Japanese Patent Laid-Open No. 6-183190 describes that a foamed resin layer is formed by injection molding a foamed resin on an outer peripheral portion of an IC module, but a limited range of only the outer peripheral portion of the IC module. Therefore, it is considered difficult to smooth the entire surface of the IC card.
Japanese Patent Laid-Open No. 2001-109863 inserts and heat-presses a spacer sheet having a size that fits inside a circle formed by the coil of the coil antenna with the IC chip, in order to remove air traps contained in the antenna coil. A non-contact type IC card and a method for manufacturing the same have been proposed, but it is considered difficult to absorb the uneven shape of the IC chip.
[0004]
[Problems to be solved by the invention]
The thickness of the IC module or IC chip mounted on the antenna sheet is 150 μm to 300 μm, and the coil antenna forms a protrusion of 20 μm to 40 μm from the surface of the antenna sheet.
These protrusions caused distortion in the printed pattern when the card base material was press-laminated, and produced irregularities on the card surface, which significantly deteriorated the appearance quality.
It has been confirmed that any of the above conventional methods for reducing the influence of the protrusions is insufficient to achieve the required appearance and smoothness.
[0005]
Therefore, in the present invention, a spacer sheet and an adhesive sheet or only an adhesive sheet are used on at least the surface of the antenna sheet on which the protrusions are provided, and a sheet having fine cavities of a certain volume ratio or more is used as a printed sheet. Thus, the present invention has been completed through research to solve such problems.
[0006]
[Means for Solving the Problems]
The first of the gist of the present invention for solving the above-mentioned problems is that an amorphous aromatic polyester is provided via an adhesive sheet having a melt viscosity of 1500 to 2500 poise on the front and back sides of an antenna sheet on which an IC chip is mounted. In a non-contact IC card in which a spacer sheet made of a resin is inserted, the front and back surfaces of the spacer sheet are sandwiched between printed sheets, and hot-pressed to form an integrated base, A biaxially stretched polyethylene terephthalate resin sheet having a fine cavity of 20 to 30% is used, and through-holes that absorb the thickness of the IC chip are formed in the front and back adhesive sheets and spacer sheets. The contactless IC card.
[0007]
The second of the gist of the present invention is a spacer made of an amorphous aromatic polyester resin through an adhesive sheet having a melt viscosity of 1500 ° C. to 1500 ° C. on the front and back of an antenna sheet on which an IC chip is mounted. Insert the sheet, sandwich the front and back of the spacer sheet between the printed sheets, place a transparent rewritable sheet capable of thermal recording on the printing surface of the front side printed sheet, and hot press to form an integral substrate In the non-contact IC card, a biaxially stretched polyethylene terephthalate resin sheet having fine cavities of 20 to 30% by volume is used as the base front and back printed sheets, and the front and back adhesive sheets and spacer sheets are A non-contact IC card, wherein a through-hole that absorbs the thickness of the IC chip is formed .
[0009]
DETAILED DESCRIPTION OF THE INVENTION
There are various types of non-contact IC cards, but in order to make the card thickness stipulated by JIS and ISO and to make the card surface smooth, the antenna sheet with the IC chip mounted is sandwiched between the card substrates on the front and back sides. It is common to have a form.
Even if a metal thin film is formed by etching without using a wire, the antenna forms a protrusion of 20 μm to 40 μm from the sheet surface as described above. Since the IC chips attached to both ends of the antenna further have a thickness (projection) of about 150 μm to 300 μm, the antenna sheet has unavoidable protrusions or irregularities, and is press-laminated between ordinary front and back substrates as it is. Therefore, an IC card with sufficiently excellent smoothness cannot be obtained.
[0010]
The present invention intends to solve this problem by using a card substrate having fine cavities inside as front and back printed sheets. Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is an exploded sectional view showing a layer structure of a card of the present invention, and FIG. 2 is a plan view of an antenna sheet used in the present invention. In FIG. 1, the scale in the thickness direction is enlarged for easy understanding.
[0011]
As shown in FIG. 2, the antenna sheet 10 has a planar coil antenna 11 on a sheet of polyethylene terephthalate (PET) or the like, and IC modules 12 are mounted on both ends 111 and 112 of the coil antenna.
Although not limited to an IC module, an IC chip that is not sealed with resin may be used.
[0012]
When the card bases are stacked, as shown in FIG. 1, adhesive sheets 13 and 14 and spacer sheets 15 and 16 are inserted between the antenna sheet 10 and the front and back printed sheets 20 and 30, respectively. For the spacer sheets 15 and 16, an amorphous polyester (PET-G) resin is preferably used. This is because the adhesiveness between the front and back printed sheets 20 and 30 can be secured. The reason why the adhesive sheets 13 and 14 are used is that the PET film as the antenna sheet does not have heat-fusibility, and serves to firmly bond the antenna sheet 10 and the spacer sheets 15 and 16. For this, a hot-melt adhesive sheet can be suitably used.
The adhesive sheet is preferably one having relatively low meltability and low melt viscosity. This is because, in the present invention, since the hot pressing is performed at a relatively low temperature, it is preferable that the melt viscosity is low in order to fill the through holes and smooth the unevenness. Empirically, it has been recognized that a melt viscosity of 190 ° C. can be sufficiently used if it is about 1500 to 2500 poise.
[0013]
Through holes 131, 141, 151, and 161 are formed in portions where the IC modules 12 of the adhesive sheets 13 and 14 and the spacer sheets 15 and 16 abut or are positioned so that the thickness of the IC module can be absorbed. ing.
In the drawing, the IC module 12 does not have protrusions on the surface-side printed sheet 20 side, but when press laminating, the surface that is not on the protrusion side is affected even if there is a difference in degree. It is preferable to form through holes in the spacer sheet 15.
[0014]
For the front and back printed sheets 20 and 30, a biaxially stretched white PET sheet that has a fine cavity in the sheet layer is used. The fine cavities can absorb the unevenness of the antenna sheet 10 when hot pressing.
The fine cavities of the front and back printed sheets preferably have 20 to 30% voids in volume ratio. Thereby, when hot-pressing, 10 to 15% of the sheet thickness can be contracted by a compressive load. However, there is a feature that the displacement hardly occurs due to the influence of biaxial stretching in the lateral direction. This is in contrast to an adhesive sheet or a spacer sheet that flows laterally by heating.
[0015]
The vertical (thickness) direction displacement due to the printed sheet and the lateral (planar) direction displacement due to the adhesive sheet or spacer sheet absorb the protrusions of the antenna sheet, thereby preventing distortion of the pattern and forming a smooth card surface. Play. Thereby, even if it is a case where printing is given to the sheet | seat before the hot press, there exists an advantage by which the shift | offset | difference and distortion of a pattern do not arise.
In general, the front side print sheet 20 is often provided with a decorative front side print 21 before pressing, and the back side print sheet 30 is often provided with a back side print 31 such as letters after pressing. It is not limited.
[0016]
In the case of transportation use or the like, a rewritable sheet 22 capable of thermal recording is attached to a part or the entire surface of the surface printing sheet. The rewrite sheet is transparent and does not interfere with the visual recognition of the surface print 31.
The rewritable sheet is capable of thermal recording, and the thermal head can clearly print the riding section and the effective period, and can be erased and reused after use. In addition, although not shown, it is also possible to provide an image receiving layer for sublimation transfer recording and to emboss characters.
[0017]
As shown in FIG. 2, the antenna sheet 10 has a planar coil antenna. The coil antenna 11 is formed of a resist on an aluminum foil or the like laminated on the sheet, and is coiled by a well-known photo-etching technique. It is what left only. The coil antenna 11 is formed so as to be wound about several turns on the card surface.
The inner end 111 of the coil can be directly connected to the IC module, but the outer coil 112 is connected to the IC module through the back surface of the sheet.
[0018]
As described above, the printing sheets 20 and 30 used for the non-contact IC card of the present invention are characterized by using a biaxially stretched polyethylene terephthalate resin sheet having fine cavities of 20 to 30% by volume.
The cavity usually has a fine disk shape centered on fine particles and parallel to the sheet surface. In such a sheet, since the cavity in the portion subjected to the strong pressure is strongly compressed, as a result, the protrusion and the uneven shape can be absorbed.
The reason why the void content is 30% or less is that when it exceeds 30%, the strength is insufficient and the card substrate is insufficient. Also, the reason why it is 20% or more is that if it is less than 20%, the content of the cavities is so small that the unevenness and the protrusion shape cannot be sufficiently absorbed.
It is about 20% lighter than a normal PET sheet, and the density is about 1.1 g / m ² . Moreover, since it has a cavity, it is white and opaque, and has excellent printability and good embossability by surface treatment.
[0019]
As described in JP-A-2001-342273 and the like, such cavities can be formed around the particles by mixing inorganic fine particles in the polyester and stretching in the sheet forming process, There is known a method in which thermoplastic resin microspheres and the like that are incompatible with a resin are mixed and dispersed in polyester, used as a core for forming cavities, and similarly stretched.
Examples of the latter cavity forming agent include polyolefin resins and polystyrene resins typified by polypropylene resins and polymethylpentene resins.
[0020]
The non-crystalline polyester resin (PETG) sheet used for the spacer sheet is generally a dehydration condensation product of an aromatic dicarboxylic acid and a diol, and has a particularly low crystallinity among the copolyesters. And a sheet made of an amorphous aromatic polyester resin.
Examples of the dicarboxylic acid include terephthalic acid, isophthalic acid, adipic acid, and naphthalenedicarboxylic acid. Examples of the diol include ethylene glycol, diethylene glycol, triethylene glycol, and 1,4-cyclohexanedimethanol.
A combination of a dicarboxylic acid component and a diol component is appropriately performed. For example, a non-crystalline aromatic polyester resin in which 30 mol% of an ethylene glycol component in polyethylene terephthalate is substituted with 1,4-cyclohexanedimethanol is a trade name. It is commercially available from Eastman Chemical Co. as “PETG”.
[0021]
【Example】
An embodiment of the present invention will be described with reference to FIGS. This is an example of manufacturing a contactless IC card for use in a ticket gate for transportation.
(Example)
<Preparation of antenna sheet>
A coil antenna 11 was formed by bonding an aluminum foil having a thickness of 20 μm to an PET film having a thickness of 50 μm via an adhesive and etching the aluminum foil. Furthermore, the IC module 12 having a thickness of 300 μm was mounted by being electrically connected to both ends of the coil, thereby completing the antenna sheet 10 included in the card.
[0022]
<Manufacture of card base>
The card substrate has a layer structure in which the adhesive sheet 13 and 14 having a thickness of 50 μm is formed on the front and back of the antenna sheet 10, the spacer sheet 15 and 16 made of PET-G having a thickness of 100 μm on the outside, and a printing having a thickness of 200 μm on the outside. Sheets 20 and 30 (manufactured by Toyobo Co., Ltd. “Chrisper”) were arranged so that the front and back sides were symmetrical.
Also, because it is used for ticket gates, the rewrite sheet 22 is placed only on the front side of the card so that the date using the card can be displayed when the card is used. Therefore, the layer structure is 8 layers.
[0023]
For the adhesive sheets 13 and 14, a polyester hot melt adhesive (melt viscosity 2000 poise: 190 ° C.) was adopted in consideration of the adhesion suitability between the PET film of the antenna sheet and the PET-G of the spacer sheets 15 and 16. .
The adhesive sheets 13 and 14 and the spacer sheets 15 and 16 on both sides of the antenna sheet 10 have the same size (about 5 mm × 5 mm) as the IC module 12 in advance so that the IC module mounted on the antenna sheet penetrates. The through holes 131, 141, 151, 161 were provided by being punched.
[0024]
In addition, on the print sheet 20 on the front side of the card, a pattern 21 that matches the arrangement of the antenna sheet was printed 21 in advance. The printing was performed by printing silk screen printing and offset printing.
As the rewritable sheet, a thermosensitive coloring type sheet having a thickness of 70 μm was used.
The antenna sheet 10 and the adhesive sheet provided with the through hole and the spacer sheet were aligned by fitting the antenna sheet, each adhesive sheet, and the spacer sheet with a hole provided in the pin.
The laminate composed of the eight layers was placed on a hot plate of a press machine and press laminated. The conditions of the pressing process were as follows: hot plate temperature 120 ° C, pressure 2.0 MPa, molding (heating) time 20 min. I went to set.
[0025]
The pattern printing 31 was performed on the back side of the card base integrated by the press, and finally it was punched into a card shape according to the pattern. In the same manner as the front side, printing was performed by printing offset printing on silk screen printing.
In this way, a non-contact IC card having a total thickness of 0.78 mm was completed. Since the total thickness of the materials used was 820 μm (not including the thickness of the coil antenna and the IC module), the printed sheets on the front and back sides contracted in the thickness direction by about 10%.
[0026]
(Comparative example)
The antenna sheet 10, the adhesive sheets 13 and 14, the spacer sheets 15 and 16, and the rewrite sheet 22 were made of the same material and thickness as in the examples, but the printed sheets 20 and 30 had a thickness of 180 μm without a cavity. Using a normal PET sheet, a non-contact IC card of a comparative example was completed under the same production conditions as in the examples.
The total thickness of this non-contact IC card was 0.78 mm.
[0027]
When the smoothness of the contactless IC cards of the example and the comparative example was measured with a surface roughness meter, the comparative example had a protrusion of a coil antenna of 10 to 15 μm, but the IC card of the example had a thickness of 5 μm. It was the following.
Further, the IC card of the example was a card having no distortion in the pattern and excellent in appearance quality.
[0028]
In the above embodiment, the front and back printed sheets have cavities and compression-shrinkable PET sheets are used, but the PET sheet has a certain smoothing effect even when used only on the projecting surface side of the antenna sheet. Thus, the present invention belongs to the technical scope of the present invention as in the second aspect of the present invention. In addition , it is obvious to those skilled in the art that the thickness and the like of each constituent layer can be freely changed within the scope of achieving the object of the present invention.
[0029]
【The invention's effect】
As described above, the non-contact IC card of the present invention uses a PET sheet having fine cavities as a surface printed sheet and having compressive shrinkage. A contactless IC card with excellent characteristics.
Since the non-contact IC card substrate of the present invention has fine cavities and has compression and shrinkage properties, a smooth flat surface can be provided even if the antenna sheet having protrusions is hot-pressed. Further, since the dimensional stability in the planar direction is excellent, there is an advantage that the distortion of the pattern does not occur.
[Brief description of the drawings]
FIG. 1 is an exploded sectional view showing a layer structure of a card according to the present invention.
FIG. 2 is a plan view of an antenna sheet used in the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Non-contact IC card 10 Antenna sheet 11 Coil antenna 12 IC module 13 and 14 Adhesive sheet 15 and 16 Spacer sheet 20 and 30 Printing sheet 21 Front surface printing 22 Rewrite sheet 31 Back surface printing

Claims (2)

A spacer sheet made of an amorphous aromatic polyester resin is inserted between the front and back surfaces of the antenna sheet on which the IC chip is mounted via an adhesive sheet having a melt viscosity of 190 ° C to 1500-2500 poise , and the spacer sheet. In a non-contact IC card in which the front and back surfaces of the substrate are sandwiched between printing sheets and pressed into a single substrate by hot pressing, biaxially stretched polyethylene having fine cavities of 20 to 30% by volume as the front and back printed sheets of the substrate A non-contact IC card, wherein a terephthalate resin sheet is used, and through-holes that absorb the thickness of the IC chip are formed in the front and back adhesive sheets and spacer sheets . A spacer sheet made of an amorphous aromatic polyester resin is inserted between the front and back surfaces of the antenna sheet on which the IC chip is mounted via an adhesive sheet having a melt viscosity of 190 ° C to 1500-2500 poise , and the spacer sheet. In a non-contact IC card in which a transparent rewritable sheet capable of heat-sensitive recording is placed on the printing surface of the front side printing sheet, and pressed into a single substrate, As the front and back printed sheets, a biaxially stretched polyethylene terephthalate resin sheet having fine cavities of 20 to 30% in volume ratio is used, and through-holes that absorb the thickness of the IC chip are used in the front and back adhesive sheets and spacer sheets A non-contact IC card characterized in that is formed .

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