JP5699474B2 - Film antenna manufacturing method - Google Patents

Description

  The present invention relates to a film antenna, and more particularly to a flexible film antenna that can be mounted on an electronic device such as a mobile communication terminal, a vehicle, and the like, and a method for manufacturing the same.

  Currently, in a small electronic device having a communication function such as a mobile communication terminal, a small antenna is mounted as a device for performing wireless communication. Further miniaturization is required for small antennas that are mounted as electronic devices are miniaturized, and antennas that are miniaturized and thinned by various methods are used.

  Conventionally, a telescopic whip antenna or the like has been used as a small antenna, but in recent years, it has been increasingly built in a housing of an electronic device or the like with the help of a higher communication frequency. As such a small built-in andena, for example, a miniaturized antenna combining a resin molded body and a bent sheet metal, a thin film antenna, or the like is used.

  For example, as a flexible antenna which is an example of a thin film antenna, an antenna formed in a spiral shape or a zigzag shape on a flexible substrate is provided separately as a transmitting antenna and a receiving antenna inside the housing of an electronic device. A technique to be mounted is known (see, for example, Patent Document 1).

  In recent years, various designs have been given to electronic devices. From the viewpoint of design and the like, sometimes a casing or component having transparency is required.

  For example, as a transparent antenna as a part having transparency or transparency, the hole diameter is used on one side or both sides of a sheet-like substrate such as a transparent or substantially transparent synthetic resin film or sheet glass to make use of the transparency of the substrate. A transparent antenna formed by laminating thin conductive layers that form an antenna pattern in which a large number of fine through holes of about 400 to 500 μm and a line width of about 80 μm are provided with an aperture ratio of about 70 to 75% in area ratio. It is known (see, for example, Patent Document 2).

JP 05-007109 A Japanese Utility Model Publication No. 03-039911

  However, when the film antenna disclosed in Patent Document 1 described above is used by being attached to a resin molded body or housing having a large curvature or a complicated shape, a conductor pattern as an antenna pattern formed on the film is obtained. It may break. In particular, when a film-like antenna using a conductor pattern having fine through holes is attached to a resin molded body or housing having a large curvature or a complicated shape, the conductor pattern is likely to be disconnected.

  Therefore, an object of the present invention is to provide a film antenna in which an antenna conductor pattern is not easily disconnected even if it is used by being attached to a resin molded body or a casing having a complicated shape, and a manufacturing method thereof.

  The film antenna of the present invention includes a carrier film that has been subjected to a release treatment, an adhesive layer that is provided on an upper part of the carrier film, a base film that is provided with the adhesive layer on a lower surface, and an upper surface of the base film. And an overcoat layer that covers the conductor pattern and has an opening in a part thereof. The carrier film is removed when the film is used as a film antenna.

  According to the film antenna of the present invention, by forming the overcoat layer on the conductor pattern, the effect of relieving the tensile stress of the conductor pattern provided on the surface of the base film can be obtained, and the conductor pattern is hardly broken. Can do. In addition, it is possible to reduce the deterioration of antenna performance by suppressing scratches due to external factors and suppressing an increase in the resistance value of the conductor pattern due to oxidation and corrosion of the pattern surface. .

  The film antenna of the present invention uses a transparent adhesive that transmits visible light as the adhesive layer, a transparent synthetic resin film that transmits visible light as the base film, and the base film as the conductor pattern. A transparent synthetic resin that uses a conductor pattern layer composed of a lattice pattern having a line width of 10 to 50 μm and a line-to-line pitch of 100 to 500 μm so as not to hinder the transparency of the film, and further transmits visible light as the overcoat layer It is characterized by comprising a made overcoat layer.

  According to such a film antenna, by forming the film antenna using a material having transparency or transparency, a transparent antenna as a part can be realized, and the overcoat layer is formed on the conductor pattern. By forming the conductive pattern, the tensile stress of the conductive pattern provided on the surface of the base film is relaxed, and even when the line width is narrow, it is possible to make it difficult to disconnect the conductive pattern. Further, it is possible to reduce the loss in the antenna by suppressing damages due to external factors and suppressing the increase in the resistance value of the conductor pattern due to oxidation and corrosion of the pattern surface.

  The film antenna of the present invention further includes a gold plating portion provided in the opening of the overcoat layer.

  According to such a film antenna, by forming the overcoat layer on the conductor pattern, the tensile stress of the conductor pattern provided on the surface of the base film can be relaxed and the conductor pattern can be made difficult to break. Further, it is possible to reduce the loss in the antenna by suppressing damages due to external factors and suppressing the increase in the resistance value of the conductor pattern due to oxidation and corrosion of the pattern surface. Furthermore, by applying gold plating only to the opening of the overcoat layer, the film antenna as a component is suppressed by suppressing oxidation of the exposed metal surface, and a transmission path for transmitting a signal from the electronic device on which the film antenna is mounted. Connection is good.

  The film antenna of the present invention includes a carrier film that has been subjected to a release treatment, an adhesive layer, a base film, a conductor pattern provided on the surface of the base film, and an overcoat layer that has an opening in part. The laminate of the adhesive layer, the base film, the conductor pattern, and the overcoat layer is punched into a desired shape leaving the carrier film, to obtain an antenna component, Only the base film other than the antenna component is removed first, and the carrier film is removed and used as a film antenna immediately before use as an antenna component.

  According to such a film antenna, by removing the carrier film just before using it as an antenna component and using it as a film antenna, workability when handling the antenna as a component can be improved, and the film antenna is mounted. As a result, it is possible to reduce the assembly work time for the electronic device.

  Moreover, in the film antenna of this invention, it is preferable that the thickness of the said base film is 16 micrometers or more and 75 micrometers or less.

  According to such a film antenna, by reducing the thickness of the base film to 16 μm or more and 75 μm or less, the tensile stress of the conductor pattern provided on the surface of the base film is reduced while maintaining the handleability as a film antenna component. The effect to do is acquired and it can make it hard to disconnect a conductor pattern.

  Moreover, in the film antenna of this invention, it is preferable that the thickness of the said carrier film is 75 micrometers or more and 200 micrometers or less.

  According to such a film antenna, when the thickness of the carrier film is 75 μm or more and 200 μm or less, the carrier film is punched through when the base film is punched into a desired antenna shape while maintaining the handling property. The effect to avoid is acquired, the workability | operativity at the time of handling an antenna as components can be improved, and it becomes possible to reduce the assembly operation time of an electronic device.

  The method for producing a film antenna according to the present invention includes a step of bonding a conductor layer on a base film having a thickness of 75 μm or less, a pressure-sensitive adhesive is applied to the lower side of the base film, and an adhesive layer is formed. A step of affixing the carrier film, a step of processing the conductor layer to form a conductor pattern, and a step of forming an overcoat layer partially having an opening on the conductor pattern. It is characterized by. In particular, the film antenna according to the present invention has a structure suitable for a manufacturing method by a roll-to-roll method.

  According to the manufacturing method of the present invention, the pre-annealing step is not necessarily required when the conductor layer is bonded onto the base film, so that the cost of the film antenna can be reduced.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the film antenna which has a conductor pattern in which a conductor pattern is hard to disconnect, or a film-like antenna which has transparency, even if it affixes and uses on the resin molded object and housing of a complicated shape. Further, by avoiding the surface of the conductor pattern from being exposed to the outside air, it is possible to suppress surface oxidation and suppress an increase in the resistance value of the conductor pattern.

It is a figure which shows the example of application of the film antenna which concerns on each embodiment of this invention. (A) is sectional drawing which shows the cross-section of the film antenna which concerns on 1st and 2nd embodiment of this invention, (b) is the outline of the film antenna which concerns on 1st and 2nd embodiment of this invention. FIG. (A) is sectional drawing which shows the cross-section of the film antenna which concerns on 3rd Embodiment of this invention, (b) is a transparent top view which shows the outline of the film antenna which concerns on 3rd Embodiment of this invention. is there. (A) is sectional drawing which shows the cross-section of the film antenna which concerns on 4th Embodiment of this invention, (b) is a transparent top view which shows the outline of the film antenna which concerns on 4th Embodiment of this invention. is there. (A), (b), (c) is a figure which shows the example of the conductor pattern in the film antenna which concerns on the 1st thru | or 4th embodiment of this invention. (A) thru | or (H) is a figure explaining the manufacturing method of the film antenna which concerns on the 1st thru | or 4th embodiment of this invention. It is a figure which shows the relationship between the thickness of the base film (PET base material) in the film antenna of one Example by this invention, and the fracture | rupture rate of a conductor pattern. It is a figure which shows the relationship between the thickness of the carrier film in the film antenna of one Example by this invention, and the shrinkage | contraction rate (pattern shrinkage | contraction rate) of a conductor pattern.

  Hereinafter, embodiments of a film antenna according to the present invention will be described in detail with reference to the drawings.

  First, the film antenna according to the present invention has been devised so that the conductor pattern is not easily broken even if it is used by being attached to a resin molded body or housing having a complicated shape. For example, as shown in FIG. Thus, it is intended to be used by being attached to the surface of an arbitrary housing 1 having a large curvature or a complicated shape. For example, the conductor of the film antenna with respect to GND on the housing 1 side A film antenna is configured by supplying power to the conductor pattern 14 through an opening 15 a provided in a part of the overcoat layer 15 that protects the pattern 14 so as to cover the pattern 14.

(First embodiment)
2A is a cross-sectional view showing a cross-sectional structure of the film antenna according to the first embodiment of the present invention, and FIG. 2B is a perspective top view showing an outline of the film antenna according to the first embodiment of the present invention. FIG.

  As shown in FIGS. 2A and 2B, the film antenna 10 includes a carrier film 11 that has been subjected to a release treatment, an adhesive layer 12, a base film 13, and a conductor pattern provided on the surface of the base film 13. 14 and an overcoat layer 15 having an opening 15a in part.

  The carrier film 11 is removed when the antenna film is used as an antenna.

  The carrier film 11 is made of a flexible resin film or paper having a surface coating as a release treatment on one side or both sides. The resin film is not particularly limited as long as it is flexible, but PE (polyethylene), PP (polypropylene), PVC (polyvinyl chloride), PET (polyethylene terephthalate), PC (polycarbonate), PI (polyimide) ) And the like.

  The adhesive layer 12 only needs to have an adhesive strength that does not peel off when the film antenna 10 is attached to a housing such as a resin molded body or an electronic device, and any adhesive can be used. An adhesive diluted with a solvent may be applied to the carrier film 11 or the base film 13 by any existing method such as roll coating, grapia coating, cup coating, etc., or a baseless double-sided adhesive tape may be used. Good.

  The base film 13 is made of a flexible resin film. The resin film is not particularly limited as long as it is flexible, but PE (polyethylene), PP (polypropylene), PVC (polyvinyl chloride), PET (polyethylene terephthalate), PC (polycarbonate), PI Examples thereof include a film made of a resin such as (polyimide).

  The conductor pattern 14 is made of a thin metal foil or metal film, and examples of the metal include copper, silver, nickel, and aluminum. From the viewpoint of functioning as an antenna element, the conductive pattern 14 is made of conductive material such as copper and silver. It is preferable to use a material with a high rate.

  As a pattern forming method for the conductor pattern 14, a thin metal foil is attached to the base film 13, and then an antenna conductor pattern is formed by exposure, development, and etching, or a photosensitive agent is applied to the base film 13 and exposed. An existing pattern forming method such as a method of forming an antenna conductor pattern by plating a metal after development can be used.

  The overcoat layer 15 having an opening 15a in part is made of a thermosetting resin or a photocurable resin. The thermosetting resin is not particularly limited as long as it is flexible, and examples thereof include an epoxy resin, a phenol resin, a urethane resin, an amino resin, and an unsaturated polyester resin. The photocurable resin is not particularly limited as long as it is flexible, and is a composition composed of a monomer, an oligomer, and a photopolymerization initiator. Various additives include stabilizers, fillers, pigments, and the like. You may go out.

  Here, the opening 15a is provided so that a part of the conductor pattern 14 is exposed in order to make an electrical connection with a transmission line for transmitting an RF signal in the electronic device.

  According to the film antenna 10 of the present embodiment, by forming the overcoat layer 15 on the conductor pattern 14, the effect of relaxing the tensile stress of the conductor pattern 14 provided on the surface of the base film 13 can be obtained. It becomes possible to make it difficult to disconnect 14. Further, it is possible to reduce the loss in the antenna by suppressing damages due to external factors and suppressing the increase in the resistance value of the conductor pattern due to oxidation and corrosion of the pattern surface. In addition, as will be described in detail later, by defining the carrier film 11 and the base film 13 to have a predetermined thickness, the effect of preventing the disconnection of the conductor pattern 14 at the time of manufacture and use of the film antenna 10 is further enhanced. Can do.

(Second embodiment)
A film antenna according to a second embodiment of the present invention will also be described with reference to FIG. It should be noted that the same constituent elements will be described with the same reference numerals.

  In the film antenna according to the second embodiment, a transparent adhesive that transmits visible light is used as the adhesive layer 12, and a transparent synthetic resin film that transmits visible light is used as the base film 13. A conductor pattern made of a lattice pattern with a predetermined line width w and a predetermined inter-line pitch p is used, and a transparent synthetic resin film that transmits visible light is used as the overcoat layer 15. Several types of lattice patterns are assumed, and for example, a square shape shown in FIG. 5A, a circle shape shown in FIG. 5B, and a honeycomb shape lattice pattern shown in FIG. . In order to have a substantially transparent function as the conductor pattern 14, it is preferable to use a lattice pattern in which the line width w is 10 to 50 μm and the line pitch p is 100 to 500 μm.

  Also in the second embodiment, the carrier film 11 can be made of the same material as that of the first embodiment.

  The pressure-sensitive adhesive 12 is a transparent pressure-sensitive adhesive that transmits visible light, and may have any adhesive strength that does not peel off when the film antenna 10 is attached to a resin molded body or housing such as an electronic device. The transparent adhesive can be used. A transparent adhesive diluted with a solvent may be applied to the carrier film 11 or the base film 13 by any existing method such as roll coating, gravure coating, cup coating, or a transparent double-sided adhesive tape without a substrate is used. May be.

  The base film 13 is made of a transparent resin film that is flexible and transmits visible light. The resin film is not particularly limited as long as it is flexible and transparent, but PE (polyethylene), PP (polypropylene), PVC (polyvinyl chloride), PET (polyethylene terephthalate), PC (polycarbonate), transparent The film which consists of resin, such as a polyimide, is mentioned.

  The conductor pattern 14 is made of a thin metal foil or metal film having a lattice pattern so as not to hinder the transparency of the base film 13, and examples of the metal include any metal such as copper, silver, nickel, and aluminum. Examples of the transparent conductive material that does not hinder the transparency can include conductive oxides such as ITO (indium tin oxide), but from the viewpoint of functioning as a flexible antenna element, the resistance value of the material is slightly high. A lattice pattern using a metal material having a high conductivity such as copper or silver is more preferable than a transparent conductive oxide in which cracks are generated by bending the film and the resistance is further increased. Furthermore, from the viewpoint of the balance between the visible light transmittance and the wavelength of the radio wave, a square or honeycomb lattice pattern having a line width w of 10 to 50 μm and a line pitch p of 100 to 500 μm is more preferable (see FIG. 5). .

  The pattern forming method of the conductor pattern 14 in the second embodiment can be the same forming method as the pattern forming method shown in the first embodiment.

  The overcoat layer 15 having a part of the opening 15a is made of a transparent thermosetting resin or a photocurable resin that transmits visible light. The thermosetting resin or the photocurable resin is not particularly limited as long as it is a flexible material that is transparent and transmits visible light, and the same material as that shown in the first embodiment can be used.

  According to the film antenna of the present embodiment, a transparent antenna as a component can be realized by configuring the film antenna using a material having transparency or transparency, and the overcoat layer 15 is formed on the conductor pattern 14. By forming the antenna conductor pattern on the surface of the base film 13 so as to ease the tensile stress of the conductor film 14 and ensure the transparency, the line width w is narrowed and the antenna conductor pattern is easily broken. In addition, it is possible to suppress damage due to external factors, and to suppress an increase in the resistance value of the conductor pattern 14 due to oxidation or corrosion of the pattern surface, thereby reducing the loss in the antenna. It becomes possible.

(Third embodiment)
FIG. 3A is a sectional view showing a sectional structure of a film antenna according to the third embodiment of the present invention, and FIG. 3B shows an outline of the film antenna according to the third embodiment of the present invention. FIG. It should be noted that the same constituent elements will be described with the same reference numerals.

  As shown in FIGS. 3A and 3B, the film antenna 30 according to the third embodiment includes a carrier film 11 that has been subjected to a release treatment, an adhesive layer 12, a base film 13, and a base film 13. A conductor pattern 14 provided on the surface, an overcoat layer 15 having an opening 15a in part, and a gold plating part 36 provided in the opening 15a of the overcoat layer 15 are provided.

  The opening 15a is provided so that a part of the conductor pattern 14 is exposed in order to establish an electrical connection with a transmission line for transmitting an RF signal in an electronic device. In some cases, contact failure may occur due to oxidation of the conductor.

  Therefore, the gold plating part 36 is formed only by the opening 15a by electrolytic plating. By adopting such a method, it is possible to suppress the amount of gold, which is an expensive material, to the minimum, and to avoid poor electrical connection with the transmission line at low cost.

  According to the film antenna 30 of the present embodiment, by forming the overcoat layer on the conductor pattern, the tensile stress of the conductor pattern provided on the surface of the base film can be relieved to make it difficult to disconnect the antenna conductor pattern. it can. Further, it is possible to reduce the loss in the antenna by suppressing damages due to external factors and suppressing the increase in the resistance value of the conductor pattern due to oxidation and corrosion of the pattern surface. Furthermore, by performing gold plating only on the opening of the overcoat layer, it is possible to suppress the oxidation of the exposed metal surface and improve the connection with a communication device or the like on which a film antenna as a component is mounted.

(Fourth embodiment)
FIG. 4A is a cross-sectional view showing a cross-sectional structure of a film antenna according to the fourth embodiment of the present invention, and FIG. 4B shows an outline of the film antenna according to the fourth embodiment of the present invention. FIG. It should be noted that the same constituent elements will be described with the same reference numerals.

  As shown in FIGS. 4A and 4B, the film antenna 40 according to the fourth embodiment includes a carrier film 41, a pressure-sensitive adhesive layer 12, a base film 13, and a base film 13 that have been subjected to a release treatment. A conductor pattern 14 provided on the surface and an overcoat layer 15 having an opening 15a in part are provided.

  This film antenna 40 is formed as an antenna component 40b by punching a laminate composed of the adhesive layer 12, the base film 13, the conductor pattern 14, and the overcoat layer 15 into a desired shape, leaving the carrier film 41, A carrier film 41 having a wider area both vertically and horizontally than the antenna component 40b is provided. For example, FIG. 4B shows that the vertical length D2 of the carrier film 41 is longer than the vertical length D1 of the antenna component 40b, and the horizontal length of the carrier film 41 is also longer than the horizontal length of the antenna component 40b. I did it.

  Here, the carrier film 41 can use the same material and the same formation method as the material and the formation method shown in the first embodiment.

As a method of forming a laminate (antenna component 40b) composed of the adhesive layer 12, the base film 13, the conductor pattern 14, and the overcoat layer 15 by punching into a desired shape while leaving the carrier film 41, the first method is as follows. After forming the film antenna in the same manner as the embodiment, after half-cutting to a thickness of about half of the carrier film 41 using a punching die such as an engraving blade, a Pinnacle (registered trademark) blade, a Thomson blade, etc., other than the antenna component 40b This can be realized by removing the laminated body part (unnecessary part).

For example, when the film antenna 40 according to the fourth embodiment is manufactured by a roll-to-roll manufacturing method, for example, a large base film (PET) 13 having a length of several hundreds m and a width of 1 m is wound in a roll shape. After the conductor pattern 14, the overcoat layer 15 and the carrier film 11 are formed, the film can be wound again on a roll. Further, the antenna component 40b is punched out while leaving the carrier film 41 to form a large number. The handling property can be improved and the cost of the film antenna 40 can be reduced accordingly.

  Further, for example, in the present embodiment, the method of removing the laminated body part (unnecessary part) other than the antenna component 40b is illustrated, but the present invention is not limited to this, and the unnecessary part of the laminated body is left without being removed. Then, the carrier film 41 and unnecessary portions of the laminated body may be removed immediately before use as the antenna component 40b and used as the film antenna 40b.

  Hereinafter, a specific example of the roll-to-roll manufacturing method will be described with reference to FIG. 6 regarding the method for manufacturing the film antenna according to the first to fourth embodiments.

  First, in a process (A), the conductor layer (copper foil) for forming the conductor pattern 14 on the base film 13 (PET) is bonded. The base film 13 has a predetermined thickness in consideration of handling when using a film antenna (details will be described later). Also, in this bonding process, pre-annealing treatment can be applied to suppress thermal deformation of the conductor layer (copper foil) in the subsequent process, but it is manufactured in terms of temperature control and process time of the pre-annealing process. Cost can increase. Therefore, in the film antenna according to the first to fourth embodiments, the pre-annealing process is not necessarily required by attaching the carrier film 11 having a predetermined thickness or more.

  In the step (B), an adhesive is applied to the lower side of the base film 13 (PET) to form the adhesive layer 12, and a carrier film 11 having a predetermined thickness or more is attached (details will be described later).

  Next, in step (C), the conductor layer is processed to form the conductor pattern 14. The conductor pattern 14 is formed by applying a photosensitive agent to the base film 13 without exposing or developing the conductor pattern of the antenna by exposure / development / etching, or bonding the copper foil in the step (A). After that, an existing pattern forming method such as a method of plating a metal to form an antenna conductor pattern can be used.

  Next, in step (D), an overcoat layer 15 having a part of the opening 15 a is formed as a transparent cover layer on the conductor pattern 14.

  Next, in step (E) performed as necessary, in order to define a roll width of a desired size, cutting with a slit is performed.

  Next, in the step (F), a partial gold plating process is performed on a part of the opening 15 a to form a gold plating layer 36.

  Next, in the step (G), a half cut is performed to a thickness of about half of the carrier film 11 using a punching die such as an engraving blade, a pinnacle blade, and a Thomson blade (the carrier film 41 remains). Through the steps so far, the film antenna according to the first to third embodiments can be manufactured.

Next, in the step (H), the laminated body part (unnecessary part) other than the antenna component 40b is removed. Through the steps so far, the film antenna according to the fourth embodiment can be manufactured.

  As described above, the film antenna according to the first to fourth embodiments has a structure and a manufacturing method suitable for preventing the antenna conductor pattern from being broken during its manufacture and use.

  In the film antennas of the first to fourth embodiments, the thickness of the base film 13 is preferably 16 μm or more and 75 μm or less.

  For example, if the thickness of the base film 13 is 15 μm or less, when using the film antenna (when the carrier film is removed and used as an antenna component), handling becomes poor and workability when assembling an electronic device is poor. turn into. On the other hand, if the thickness of the base film 13 exceeds 75 μm, the tensile stress in the conductor pattern 14 increases and cracks in the conductor pattern 14 are likely to occur.

  Thus, by making the thickness of the base film 16 μm or more and 75 μm or less, the effect of alleviating the tensile stress of the conductor pattern provided on the surface of the base film can be obtained while maintaining the handleability when using the film antenna. The antenna conductor pattern can be made difficult to break.

  In the film antennas of the first to fourth embodiments, the thickness of the carrier film 11 is preferably 75 μm or more and 200 μm or less.

  For example, if the thickness of the carrier film 11 is less than 75 μm, the handling property in roll-to-roll manufacturing is deteriorated, and the carrier film is punched through when half-cutting the base film into a desired antenna shape. It becomes easy. Further, if the thickness of the carrier film 11 exceeds 200 μm, the tensile stress of the conductor layer for forming the conductor pattern 14 in the roll-to-roll manufacturing increases, and the crack of the conductor pattern 14 is likely to occur during the manufacturing. turn into.

  Thus, when the thickness of the carrier film is 75 μm or more and 200 μm or less, the carrier film can be punched into a desired antenna shape while maintaining the handleability in roll-to-roll manufacturing. The effect of avoiding through punching is obtained, the workability when handling the antenna as a part can be increased, and the assembly work time of the electronic device can be reduced.

  The example which confirmed the effect on specific conditions about the thickness of the base film 13 and the thickness of the carrier film 11 is described below.

(Base film thickness)
FIG. 7 is a diagram showing the relationship between the thickness of the base film (PET substrate) and the breaking rate of the conductor pattern in the film antenna of one example according to the present invention.
<Prerequisites>
Overcoat layer: 10 μm thick Copper body layer (copper foil): 10 μm thick, 10 μm wide 10 lines Adhesive layer: 30 μm thick Base film (PET substrate) thickness: variable from 12 to 125 μm <Results>
FIG. 7 shows the number of fractures when 10 lines of 10 μm thickness and 10 μm width are wound around a part of curvature 1 for each of the base film (PET substrate) thicknesses 12, 25, 50, 75, 100, and 125 μm. FIG. From FIG. 7, it can be seen that there is a certain relationship between the thickness of the base film (PET base material) and the breaking rate of the conductor pattern. In particular, in view of mass production efficiency, the base film (PET base material) having a thickness of 75 μm or less It is preferable to use a base film (PET base material) having a thickness of 50 μm or less.

(Carrier film thickness)
FIG. 8 is a diagram showing the relationship between the thickness of the carrier film and the contraction rate of the conductor pattern (pattern contraction rate) in the film antenna of one example according to the present invention.
<Prerequisites>
Overcoat layer: 10 μm thick Copper body layer (copper foil): 10 μm thick, 10 μm wide 10 lines Adhesive layer: 30 μm thick Base film (PET substrate) thickness: 25 μm Processing condition: 150 ° C, 30 to 60 sec. Carrier film thickness: variable from 25 to 200 μm <Result>
FIG. 8 shows that the carrier film thicknesses 25, 50, 75, 100, 125, 150, 175, and 200 μm are each 5 m / min in a drying furnace 5 m that is a processing process condition (150 ° C., 30 to 60 seconds). It is the figure which plotted the pattern shrinkage rate from the dimensional change of the copper foil pattern at the time of flowing. FIG. 8 shows that there is a certain relationship between the thickness of the carrier film and the contraction rate of the conductor pattern. In particular, when the contraction rate at the use limit (peeling limit) is 1.2%, the carrier having a thickness of 75 μm or more. A film is preferred.

  The present invention has been described above by taking the first to fourth embodiments as examples. The present invention is not limited to these embodiments, and can be applied to various conductor patterns, for example.

  Moreover, although the range of the preferable thickness in a carrier film and a base film was described, it is not restricted to these ranges, You may use out of this range depending on the manufacturing process and the situation used as an antenna component.

  According to the present invention, there are provided a film antenna, a transparent film antenna having transparency, and a method for manufacturing the same, in which an antenna conductor pattern is not easily disconnected even when used by being attached to a resin molded body or a casing having a complicated shape. In particular, it is possible to contribute to the production of small and light electronic devices and electronic devices rich in design.

DESCRIPTION OF SYMBOLS 1 Housing 10, 30, 40 Film antenna 11, 41 Carrier film 12 Adhesive layer 13 Base film 14 Conductor pattern 15 Overcoat layer 36 Gold plating part 15a Opening part 40b Antenna component

Claims (3)

A method of manufacturing a film antenna by a roll-to-roll method,
Bonding a conductor layer on a base film having a thickness of 75 μm or less;
Applying a pressure-sensitive adhesive to the lower side of the base film to form an adhesive layer, and further affixing a carrier film having a thickness of 100 μm or more and 200 μm or less;
Processing the conductor layer to form a conductor pattern;
Forming an overcoat layer having an opening in part on the conductor pattern;
A method of manufacturing a film antenna, comprising: The method further comprises a step of forming a laminate comprising the adhesive layer, the base film, the conductor pattern, and the overcoat layer into an antenna component by punching into a predetermined shape while leaving the carrier film. The method for manufacturing a film antenna according to claim 1 . A step of punching the laminate comprising the adhesive layer, the base film, the conductor pattern, and the overcoat layer into an antenna component by punching into a predetermined shape, leaving the carrier film; further comprising the step of removing the laminate portion than the antenna part (unnecessary portion) after the method of manufacturing a film antenna according to claim 1 or 2.

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