JP2000048154A - Method for forming antenna for non-contact ic module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make simply formable an antenna for a non-contact IC module at a low cost and with high sensitivity by providing a metallic thin layer on a holding substrate through an adhesive and irradiating the metallic thin layer with laser beams so as to sublimate and remove the metallic thin layer except in an antenna forming area to form the antenna. SOLUTION: A metallic foil 6 is adhered to one surface of the holding substrate 2 through an adhesive layer 7a consisting of an adhesive 7 to form the metallic thin layer 9 on the one surface of this substrate 2. After the adhesive 7 is hardened, the layer 9 obtained by sticking the foil 6 to one surface of the substrate 2 is irradiated with laser beams by the negative pattern of the antenna 4 to sublimate and remove the unnecessary part of the layer 9 to form the antenna 4 on one surface of the substrate 2 by this sublimation obtained by irradiating with laser beams. Then, a coating member 5 is fitted through an adhesive 10 to obtain the antenna for the noncontact IC module.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for forming an antenna for a non-contact IC module.

[0002]

In recent years, as disclosed in JP-A-5-166018 and JP-A-8-216570, a transmission medium is provided between a holding base and a covering member. 2. Description of the Related Art A non-contact type IC card has been proposed in which an antenna for transmitting and receiving electromagnetic wave data and a module including an IC chip having a function of writing, holding, rewriting and erasing the data are sandwiched. In this non-contact type IC card, it is necessary to make the antenna connected to the IC module thin. In forming the antenna, a vapor deposition method of directly performing metal vapor deposition on the holding base of the IC module, An etching method in which a thin metal layer is formed in advance and etched, a coil bonding method in which a separately formed coil is bonded to a holding base, and a conductive ink printed on the holding base in an antenna shape to form an antenna. The antenna was formed by a conductive ink printing method or the like.

[0003] However, among the above-described antenna forming methods, the sensitivity of the formed antenna is relatively high by the metal deposition method. If the unevenness is present, the unevenness is formed on the metal-deposited surface directly under the influence of the surface condition, so that the disturbance of the electromagnetic field distribution is increased and the sensitivity of the antenna is reduced. In addition, the above-mentioned etching method is a method for easily forming an antenna shape arbitrarily, but involves many work steps such as application of a resist agent, pattern formation on the resist agent, and etching with an etching solution, which requires expensive equipment work. The environment is also required, raising the production cost. Then, it is necessary to safely treat a large amount of waste liquid generated during the etching step. Although the antenna formed by the coil bonding method has excellent sensitivity, the workability is poor because the metal coil is directly bonded to the surface of the holding base. In addition, there is a problem that there are many difficulties in securely bonding the metal coil to the holding base, and the productivity is poor. In the conductive ink printing method, the antenna shape can be arbitrarily formed using a printing method and the workability is good, but there is a problem that the antenna sensitivity is inferior because a non-conductive substance such as an ink vehicle is mixed. Was. Therefore, the present inventors have paid attention to the fact that by irradiating a thin metal layer with laser light, the thin metal layer at the irradiated portion can be sublimated and removed in a pattern. It is an object to easily form an antenna for a contact IC module, and to obtain a low-cost and highly sensitive antenna.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has a thin metal layer provided on a holding base for disposing a non-contact IC module via an adhesive. A method for forming an antenna for a non-contact IC module, which comprises forming an antenna by sublimating and removing a thin metal layer other than an antenna forming region by irradiating a laser beam to the antenna to solve the above problem. is there. In the present invention, the metal thin layer can be a metal vapor-deposited layer formed on a transfer substrate by vapor deposition and transferred from the transfer substrate to the holding substrate side,
It can be formed by vapor deposition on a transfer base material and transferred from the transfer base material to the holder side. Further, it is preferable to apply a laser light absorber to the surface of the thin metal layer.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described in detail with reference to the embodiments shown in FIGS. In the drawing, reference numeral 1 denotes a non-contact type IC card, in which a non-contact type IC module 3 and an antenna 4 connected to the non-contact type IC module 3 are arranged on the surface of a holding base 2, and a covering member 5 is superposed thereon. Have been. The antenna 4 in the non-contact type IC card 1 is formed as follows. As shown in FIG. 2A, first, an adhesive 7 is applied to the back surface of the metal foil 6 which is the base material of the antenna 4,
A laser light absorber 8 is applied to the surface of the metal foil 6 by a spray method. Then, as shown in FIG.
A metal foil 6 is adhered to one side of the holding base 2 via an adhesive layer 7a made of the adhesive 7 on one side of the holding base 2,
A thin metal layer 9 is formed on one side of the holding base 2. Since the holding substrate 2 is adhered to one surface of the holding base 2 via the adhesive 7, even if there is unevenness on one surface of the holding base 2 on which the metal foil 6 is stuck, the flexible adhesive 7 is used. The adhesive layer 7a having a certain thickness (application thickness) is made of the same, so that the shape of the unevenness is leveled, and the shape of the unevenness of the holding base 2 may break the smoothness of the thin metal layer 9. Absent. Of course, the metal foil 6 itself is manufactured in advance and has a uniform thickness and flat front and back surfaces.

After the adhesive 7 is cured, as shown in FIG. 2C, a laser beam is applied to the thin metal layer 9 having the metal foil 6 adhered to one surface of the holding base 2 in a negative pattern of the antenna 4. The antenna 4 is formed on one surface of the holding base material 2 by sublimation of the unnecessary metal thin layer 9 by irradiating the laser light. The sublimation of the thin metal layer also removes the laser light absorber applied thereon. After that, a non-contact IC module is arranged on one side of the holding base 2 on which the antenna 4 is formed, and connection with the antenna 4 is made. Then, as shown in FIG. By sticking the member 5 via the adhesive 10, a non-contact IC card can be obtained.

[0007] The thickness of the thin metal layer 9 using the metal foil 6 is larger than the thickness of the thin metal layer formed by using a metal vapor deposition technique. The laser light absorbing agent 8 is applied so as not to cause sublimation, so that sublimation occurs efficiently in the metal foil portion of the negative pattern to be sublimated and removed. Therefore, when the thickness of the metal foil for obtaining the thin metal layer is small and pattern formation by laser beam irradiation can be performed with high resolution, the application of the laser light absorber is not necessary. The laser light absorber 8 depends on the conditions of the laser light to be applied. For example, a material obtained by mixing a near infrared absorber with a binder component such as OP varnish or PVA is preferable. In this case, the near-infrared absorbing agent includes a myanine dye, a thionyl nickel complex, a bis-
Metal complexes such as [miss 1,2-toluyl] ethylene-1,2 dithiolate nickel, bis- [1 chloro-3,4 dithiolate] nickel / tetrabutylammonium, or squarylium dyes, polymethine dyes,
Various dyes such as (di) immonium dye, phthalocyanine dye, triallylmethane dye, and naphthoquinone dye are exemplified.

FIG. 3 shows another example. In the example shown in FIG. 3, the antenna 4 is obtained by metal deposition. In this example, as shown in FIG. 3A, first, a metal-deposited layer transfer sheet 13 having a metal-deposited layer 12 as a transfer base material 11 is used. The adhesive 7 is applied to the surface of the metal deposition layer 12. Then, a metal-deposited layer transfer sheet 13 is adhered to one surface of the holding base 2 via an adhesive layer 7a made of the adhesive 7, and as shown in FIG. The substrate 11 is peeled off, the metal deposition layer 12 is transferred, and a thin metal layer 9 is formed on one surface of the holding base 2. In this example, as in the above-described embodiment, the metal deposition layer 12 is disposed on one side of the holding base 2 with the adhesive 7 interposed therebetween. Even if there is unevenness on one surface on the side where the transfer is performed, the shape of the unevenness is leveled by the adhesive layer 7a when the metal vapor deposition layer transfer sheet 13 is bonded, and the shape of the unevenness of the holding base 2 is reduced. The smoothness of the thin metal layer 9 is not lost. Furthermore, in the transferred metal deposition layer 12, the transfer base material 11 is formed by vapor deposition in advance, and when the transfer base material 11 is peeled, the peeled surface on the transfer base material 11 side appears as a smooth surface. become,
The surface of the metal deposition layer 12 transferred to the holding substrate 2, that is,
The surface of the thin metal layer 9 is much smoother.

Thereafter, the metal thin layer 9 on one side of the holding base 2 is irradiated with a laser beam in the negative pattern of the antenna 4 to remove unnecessary portions of the metal foil 6 by sublimation.
As shown in (c), the antenna 4 is formed on one surface of the holding substrate 2 by sublimation by irradiating the laser beam.
Then, a non-contact IC module is arranged on one side of the holding base 2 on which the antenna 4 is formed, and connection with the antenna 4 is performed. As shown in FIG. A non-contact IC card is obtained by adhering 5 through the adhesive 10.

Examples of irradiation conditions of laser light for sublimating and removing the negative pattern portion of the antenna in the thin metal layer and the resistance value of the deposited layer are shown below.

[0011]

[Table 1] ● Laser irradiation conditions ・ Use carbon dioxide laser transmitter and galvanometer with output of 50W and 100W ・ Scanning speed: 500-1000mm / sec (for metal foil) Metal foil thickness (μm) Laser output (W) Scan Speed (mm / sec) 10 50 800 (in the case of a metal deposition layer) Metal deposition layer thickness (μm) Laser output (W) Scanning speed (mm / sec) 0.5 100 500 0.1 50 500 0.01 50 800 ● Evaporation layer resistance value Metal evaporation layer thickness (μm) Width (mm) Length (m) Resistance value (Ω) 0.2 1 1 100 0.25 1 20 0.2 1 0.5 50 0.02 1 1 1000 0.02 5 1 200 0.02 5 0.5 100

[0012]

As described above, the non-contact I of the present invention
According to the method of forming the antenna for the C module, the non-contact I
Forming an antenna by providing a thin metal layer on a holding base for arranging the C module via an adhesive and irradiating the thin metal layer with laser light to remove the thin metal layer other than the antenna formation region by sublimation. It is a feature. As described above, since the thin metal layer for forming the antenna is provided on the holding base via the adhesive, the unevenness on the surface of the holding base is absorbed by the adhesive, and the influence of the unevenness is reduced by the thin metal layer. Since it does not appear on the side and it is easy to form the thin metal layer itself with a uniform thickness, a holding base provided with the thin metal layer having a smooth surface can be easily formed. Become like Then, it is easy to irradiate the thin metal layer with a laser beam in a pattern, and unnecessary portions in the thin metal layer are removed by sublimation, so that the antenna can be formed efficiently and the antenna surface can be efficiently formed. However, it is possible to form an antenna which is smooth and does not easily cause disturbance of the electromagnetic field distribution at low cost. If the metal thin layer is formed as a metal deposited layer which is formed by vapor deposition on the transfer base material and transferred from the transfer base material to the holder, or if a thin metal layer is obtained from a metal foil, the metal disposed on the holding base may be used. The surface of the thin layer can be made even smoother. Furthermore, if a laser light absorber is applied to the surface of the thin metal layer,
Even if the thickness of the thin metal layer is large, there is an effect that pattern formation by laser beam irradiation can be performed with high resolution.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing an example of a non-contact type IC card in an exploded state.

FIG. 2 is an explanatory view showing an example of a method for forming an antenna for a non-contact IC module according to the present invention using a metal foil.

FIG. 3 is an explanatory diagram showing an example of the present invention using a metal deposition transfer sheet.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Non-contact IC card 2 ... Holding base 4 ... Antenna 6 ... Metal foil 7, 10 ... Adhesive 7a ... Adhesive layer 8 ... Laser light absorber 9 ... Thin metal layer 11 ... Transfer base material 12 ... Metal deposition layer 13 ... Transfer sheet for metal deposition layer

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2C005 MA18 NA09 PA14 PA18 PA27 RA30 TA22 5B035 AA04 BA05 BB09 CA01 CA08 CA23

Claims (4)

[Claims] 1. A thin metal layer is provided on a holding base for arranging a non-contact IC module via an adhesive, and the thin metal layer other than the antenna forming area is sublimated and removed by irradiating the thin metal layer with laser light. A method for forming an antenna for a non-contact IC module, comprising: 2. The non-contact IC module antenna according to claim 1, wherein the thin metal layer is a metal deposition layer formed by vapor deposition on a transfer substrate and transferred from the transfer substrate to the holding substrate side. Forming method. 3. The method for forming an antenna for a non-contact IC module according to claim 1, wherein said thin metal layer is a metal foil. 4. The non-contact I according to claim 1, wherein a laser light absorbing agent is applied to the surface of the thin metal layer.
A method for forming an antenna for a C module.