WO2011155401A1

WO2011155401A1 - Film antenna and manufacturing method thereof

Info

Publication number: WO2011155401A1
Application number: PCT/JP2011/062781
Authority: WO
Inventors: 隆司松川; 禎倫佐藤; 大助寺師
Original assignee: 株式会社フジクラ
Priority date: 2010-06-07
Filing date: 2011-06-03
Publication date: 2011-12-15
Also published as: JPWO2011155401A1

Abstract

The disclosed film antenna manufacturing method involves: a step for bonding a temporary fixing film to one side of a resin film substrate which has on the other side a first conductive layer; a step for bonding on the surface of said other side of the film substrate a masking film formed having plating treatment holes so as to cover the first conductive layer but not the power source for plating treatment; a step for applying a voltage to the first conductive film by means of the power source for plating treatment and forming by plating a second conductive layer on the first conductive layer exposed through the plating treatment holes; a step for peeling the masking film from the film substrate; a step for cutting the film substrate into the shape of an antenna circuit unit which includes the second conductive layer; a step for peeling from the temporary fixing film the resin film and the first conductive layer in at least the portion around the antenna circuit unit; a step for bonding a cover film to the aforementioned other side of the film substrate; a step for peeling the temporary fixing film from the film substrate; and a step for bonding the cover film and a base film such that at least the portion of the antenna circuit unit around the first conductive layer is sandwiched between the cover film and the base film so as to be tightly surrounded.

Description

Film antenna and manufacturing method thereof

The present invention relates to a film antenna and a manufacturing method thereof, and more particularly to a film antenna used in a small wireless electronic device such as a mobile phone and a portable information terminal and a manufacturing method thereof.
This application claims priority based on Japanese Patent Application No. 2010-130393 for which it applied to Japan on June 07, 2010, and uses the content here.

In recent years, further downsizing, weight reduction, and multifunctionalization of small wireless electronic devices such as mobile phones and personal digital assistants (PDAs) have been rapidly progressing. As these small wireless electronic devices, mobile phones having a wireless communication function such as Bluetooth (registered trademark) and wireless LAN have been commercialized. This type of small wireless electronic device incorporates a small antenna for realizing a wireless communication function.

An example of this small antenna is disclosed in Patent Document 1. In the small antenna disclosed in Patent Document 1, a configuration in which a radiation conductor pattern, a feed line, and a ground line are integrally formed on one surface of a plastic sheet is employed. In paragraph [0030] of Patent Document 1, it is described that it is preferable to apply gold plating to the power supply line and the ground line for supplying power via other components in order to reduce electric resistance.

There is an electroplating method as one of plating methods when circuit formation is performed by etching (see, for example, Patent Document 2). For example, paragraph [0007] of Patent Document 2 describes that a plating lead for applying a voltage is indispensable for the use of the electroplating method, following the description regarding the necessity of the plating treatment. Yes.

However, if a plating lead as described above is present in an antenna (especially a small film antenna), it will have a metallic unique shape by this plating lead, that is, a shape that is not effective for exhibiting the function as an antenna. Since the shape itself becomes an antenna with a resonance frequency, the antenna transmission / reception characteristics may be deteriorated.

Also, since the plating lead extends to the end of the film, as a result, the metallic circuit layer is exposed to the outside, and corrosion may occur in that portion.

Japanese Patent Laid-Open No. 11-168316 Japanese Unexamined Patent Publication No. 2003-347699

The present invention has been made in view of the circumstances as described above, and provides a film antenna capable of preventing corrosion of an antenna circuit portion without deteriorating transmission / reception characteristics, and a method for manufacturing the same. Objective.

In order to solve the above problems and achieve the object, the present invention adopts the following.
(1) A method for producing a film antenna according to an aspect of the present invention includes: a step of attaching a temporarily fixing film to the other surface of a film substrate in which a first conductive layer is provided on one surface of a resin film; Bonding a masking film having a plating process hole formed on the one surface side of the film substrate so as to cover the first conductive layer except for the plating process power supply part; and the plating process power supply part Applying a voltage to the first conductive layer to form a second conductive layer on the first conductive layer exposed from the plating hole; and peeling the masking film from the film substrate; Cutting the film substrate into the shape of an antenna circuit portion including the second conductive layer; and the first conductive layer and the resin film at least around the antenna circuit portion. Peeling the film from the temporarily fixed film; bonding the cover film to the one surface side of the film substrate; peeling the temporarily fixed film from the film substrate; and the cover film and the base And a step of sandwiching and bonding the film so that at least the periphery of the first conductive layer of the antenna circuit portion is tightly enclosed between them.

(2) In the method for manufacturing a film antenna according to (1), the temporary fixing film, the cover film, and the base film may have a surface area larger than that of the film substrate.
(3) The method for manufacturing a film antenna according to (1) may further include a step of bonding a reinforcing plate to a surface of the base film opposite to a surface to be bonded to the film substrate. .

(4) A film antenna according to an aspect of the present invention includes: a first conductive layer laminated on one surface of a resin film; and a second conductive layer laminated on at least a part of the first conductive layer. A film substrate provided with an antenna circuit portion; a cover film attached to the one surface of the film substrate with an adhesive; and a film substrate attached to the other surface of the film substrate with an adhesive A base film; and at least the periphery of the first conductive layer of the antenna circuit portion is sandwiched between the cover film and the base film to be tightly surrounded.

(5) The film antenna according to (4) may further include a reinforcing plate that is bonded to a surface of the base film that is opposite to a surface that is bonded to the resin film.

According to the method for manufacturing a film antenna and the film antenna according to the above aspect of the present invention, since the plating lead as in the conventional configuration is not necessary, the antenna transmission / reception characteristics are not deteriorated, and at least the first conductive layer is formed. Since the periphery is tightly surrounded by being sandwiched between the cover film and the base film, corrosion of the antenna circuit portion can be prevented.

It is a flowchart which shows each process of the manufacturing method of the film antenna which concerns on one Embodiment of this invention. 2 is a perspective view of a masking film 1 for explaining one process of the embodiment. FIG. It is a fragmentary sectional view at the time of seeing the same masking film 1 in the cross section of the thickness direction. 2 is a partially enlarged plan view of the masking film 1. FIG. It is a figure for demonstrating the next process of FIG. 2A, Comprising: It is a perspective view which shows bonding with the plastic film (film substrate) 2 with copper foil, and the slightly adhesive plastic film (temporary fixing film) 3. FIG. It is a fragmentary sectional view at the time of seeing the plastic film 2 with copper foil in the cross section of the thickness direction. It is a fragmentary sectional view at the time of seeing the slightly adhesive plastic film 3 in the cross section of the thickness direction. It is a figure for demonstrating the next process of FIG. 3A, Comprising: It is a perspective view which shows the state after bonding the plastic film 2 with copper foil, and the slightly adhesive plastic film 3. FIG. It is a figure which shows the laminated structure of the plastic film 2 with copper foil shown in FIG. 4A, and the slightly adhesive plastic film 3, Comprising: It is a fragmentary sectional view at the time of seeing in the cross section of these thickness directions. It is a perspective view for demonstrating the next process of FIG. 4A. It is a fragmentary sectional view for demonstrating the next process of FIG. 4A. It is a top view for demonstrating the next process of FIG. 5A and 5B. It is a perspective view for demonstrating the next process of FIG. It is a fragmentary sectional view for demonstrating the next process of Drawing 7A. It is a fragmentary sectional view for demonstrating the next process of Drawing 7B. It is a perspective view for demonstrating the next process of FIG. 7B. It is a perspective view for demonstrating the next process of FIG. 8B. It is a perspective view for demonstrating the next process of FIG. 8C. 3 is a partial cross-sectional view of a cover film 4. FIG. It is a perspective view for demonstrating the next process of FIG. 9A. It is a fragmentary sectional view for demonstrating the next process of FIG. 9A. It is a figure for demonstrating the next process of FIG. 9A, Comprising: It is a fragmentary sectional view in the position of the gold plating 33. FIG. It is a perspective view for demonstrating the next process of FIG. 10A. It is a perspective view for demonstrating the next process of FIG. 11A. It is a fragmentary sectional view in the position of antenna circuit part 35 of Drawing 11B. It is a fragmentary sectional view in the position of the gold plating 33 of the antenna circuit part 35 of FIG. 11B. It is a perspective view for demonstrating the next process of FIG. 11B. 2 is a partial cross-sectional view of a base film 5. FIG. It is a fragmentary sectional view for demonstrating the next process of FIG. 12A. 12B is a diagram for explaining the next step of FIG. 12A, and is a partial cross-sectional view of the antenna circuit unit 35 at the position of the gold plating 33. FIG. It is a perspective view for demonstrating the next process of FIG. 12C and FIG. 12D. 3 is a partial cross-sectional view of a reinforcing plate 6. FIG. It is a perspective view for demonstrating the next process of FIG. 13A. It is a back surface perspective view of Drawing 13C. It is a perspective view for demonstrating the next process of FIG. 13C. FIG. 14B is a perspective view of FIG. 14A. FIG. 14B is a rear perspective view of FIG. 14A. It is a top view for demonstrating the characteristic of the film antenna manufactured by the manufacturing method of the embodiment. It is a disassembled side view for demonstrating the characteristic of the film antenna. It is a disassembled perspective view for demonstrating the characteristic of the film antenna. It is a figure for demonstrating the characteristic of the film antenna, Comprising: It is the B section enlarged view of FIG. 15A. It is a figure for demonstrating the characteristic of the film antenna, Comprising: It is the C section enlarged view of FIG. 15C. It is a back view for demonstrating the characteristic of the film antenna. It is the elements on larger scale for demonstrating the conventional film antenna. It is a partial expansion perspective view of the film antenna.

Hereinafter, an embodiment of a film antenna and a manufacturing method thereof according to the present invention will be described in detail with reference to the drawings.
FIG. 1 is a flowchart showing each step in the film antenna manufacturing method according to the present embodiment. 2A to 14C are diagrams for explaining each of the above steps. Hereinafter, each process will be described with reference to these drawings.

First, as shown in FIG. 2A, a plurality of plating processing holes 11 are formed by punching a plurality of locations in a plating processing masking film 1 having a substantially rectangular shape into a desired shape (step S1 in FIG. 1). In the example shown, it is formed at 8 locations). At this time, as shown in FIG. 2C, the hole 11 is formed in consideration of the positional deviation when the masking film 1 is applied in the process described later. That is, in a later-described process, the hole 11 that is about 0.5 mm larger in the radial direction than the edge of the region A where the gold plating is exposed through the hole 42 corresponding to the antenna feeding portion formed in the cover film 4. I can make it. At this time, in addition to the holes 11, positioning holes 11 a are simultaneously formed at the four corners of the masking film 1 for positioning in a later step.
Further, the masking film 1 is provided with two notches 12 in order to form a plating treatment power supply portion 32 used in the later-described electroplating treatment.

The masking film 1 is a film that can be once peeled off after being applied, and as shown in the partial cross-sectional view of FIG. 2B, a base material 1a and an adhesive 1b applied to one surface of the base material 1a It has. Although PET is mainly used as the substrate 1a, polyvinyl chloride (PVC), polypropylene (PPC), or polyethylene (PE) may be used instead of PET.

Next, separately from the masking film 1 obtained in step S1, a plastic film with copper foil (film substrate) 2 and a slightly adhesive plastic film (temporary fixing film) 3 shown in FIG. 3A are prepared.
As shown in the partial cross-sectional view of FIG. 3B, the plastic film 2 with copper foil includes a copper foil film (first conductive layer) 2a and a plastic sheet (resin film) 2b attached to one surface of the copper foil film 2a. And an adhesive 2c applied to the surface of the plastic sheet 2b opposite to the surface to which the copper foil film 2a is attached.
As shown in the partial cross-sectional view of FIG. 3C, the slightly adhesive plastic film 3 includes a plastic sheet substrate 3a and an adhesive 3b applied to one surface of the plastic sheet substrate 3a.

The thickness of the copper foil film 2a is, for example, 6 μm to 18 μm. As the plastic sheet 2b, it is preferable to employ a PET film having a thickness of, for example, 6 μm to 25 μm. The adhesive 2c is preferably a thermoplastic adhesive, but this is not an essential component.
As the plastic sheet substrate 3a, it is preferable to use PET, but polyethylene or polypropylene may be used. The pressure-sensitive adhesive 3b only needs to have a slight pressure-sensitive adhesive property, and preferably has a low adhesive strength of about 0.1 N / cm to 1 N / cm.

Therefore, for the purpose of temporarily adhering the plastic film 2 with copper foil to the slightly adhesive plastic film 3, as shown in the perspective view of FIG. 3A, the adhesive 2c of the plastic film 2 with copper foil is used as the slightly adhesive plastic film 3. Is attached to the adhesive 3b (step S2 in FIG. 1).
In this step S2 described above, the temporary fixing film (slightly adhesive plastic film 3) is provided on the other side of the film substrate (plastic film 2 with copper foil) provided with the first conductive layer on one side of the resin film. A bonding process is performed.

Next, as shown in the perspective view of FIG. 4A, positioning holes 21 for determining the positional relationship with the masking film 1 are formed on the laminated plastic film 2 with copper foil and the slightly adhesive plastic film 3. A plurality (four in the four corners in the illustrated example) are opened (step S3 in FIG. 1). In addition, in the state which bonded the plastic film 2 with a copper foil, and the slightly adhesive plastic film 3, the both ends of the plastic film 3 have protruded from the longitudinal direction both ends of the plastic film 2 with a copper foil, and these are a pair of glues It has become generations 31. These margins 31 are used in the subsequent laminating process.
In order to more clearly show the laminated structure when the plastic film with copper foil 2 and the slightly adhesive plastic film 3 are bonded together, FIG. 4B shows a partial cross-sectional view.

Next, as shown in FIG. 5A, with respect to the copper foil film 2a of the plastic film 2 with copper foil and the plastic film 3 (hereinafter referred to as bonded films 2 and 3) which are bonded together and perforated in step S3 Then, the masking film 1 produced in step S1 is pasted while being aligned so that the positioning holes 21 and the positioning holes 11a are aligned with the adhesive 1b facing each other (see FIG. Step S4). This pasting is performed by the adhesive force of the pair of adhesive margins 31.
In this step S4 described above, the masking film 1 is formed so as to cover the first conductive layer (copper foil film 2a) on one surface of the film substrate (copper foil-attached plastic film 2) except for the power supply portion 32 for plating treatment. The process of bonding is performed.

In addition, the laminated structure of the masking film 1 and the laminated structure of the

bonding films

2 and 3 are shown in the fragmentary sectional view of FIG. 5B. By laminating the masking film 1 on the

laminated films

2 and 3 as shown in FIG. 5B, the base material 1a, the adhesive 1b, the copper foil film 2a, the plastic sheet 2b, the adhesive 2c, and the adhesive are arranged from above. 3b and a laminated structure in which the plastic sheet base material 3a overlaps in this order.

As shown in FIG. 6, when the masking film 1 and the

bonding films

2 and 3 are bonded together, the pair of the notches 12 described above is formed in the masking film 1, so that the copper foil film 2a is exposed from these. By doing so, a pair of plating process power supply portions 32 is formed.
By applying a voltage between the plating processing power supply portions 32 and supplying gold to the portions excluding the plating processing power supply portions 32, the entire copper foil film 2a serves as a plating lead, and the copper foil film 2a Of these, gold plating is applied only to the portions exposed through the respective plating processing holes 11 (electroplating processing, step S5). That is, in this step S5, a voltage is applied to the first conductive layer 2a, and the second conductive layer 33 is formed by plating on the first conductive layer 2a exposed from each plating processing hole 11 of the masking film 1. Become.

Next, as shown in the perspective view of FIG. 7A, the masking film 1 is peeled off from the bonded films 2 and 3 (step S6). When the masking film 1 is peeled off, the gold plating (second conductive layer) 33 is formed at a desired location on the copper foil film (first conductive layer) 2a of the bonded

films

2 and 3. 7B shows the laminated structure of the gold plating 33 portion after the masking film 1 is peeled off.

Next, as shown in the partial cross-sectional view of FIG. 8A, by half-cutting (half-cutting) from the copper foil film 2a side of the bonded

films

2 and 3 using a blade type (for example, pinnacle type) or a laser. As shown in the perspective view of FIG. 8B, slits (notches) 34 for forming an antenna circuit portion 35 described later and a frame-like body 35a around them are formed. As shown in FIG. 8A, half-cutting here means that the copper foil film 2a, the plastic sheet 2b, and the adhesive 2c are completely cut, and further the adhesive 3b is cut to a certain depth. The material 3a is not cut at all. By performing this half-cutting, the plastic film 2 with copper foil is held by the adhesive 3b so as not to be displaced between the cut portions, but the holding force of the adhesive 3b is guaranteed. If possible, the plastic sheet substrate 3a may be cut to a certain depth.

Then, as shown in the perspective view of FIG. 8C, only the plurality of antenna circuit portions (antenna circuit shape portions) 35 are left, and the copper foil film 2a, the plastic sheet 2b, and the adhesive 2c are integrated to form a slightly adhesive plastic film 3 (Step S7). That is, in this step S7, after half cutting, the first conductive layer (copper foil film 2a) and the resin film (plastic sheet 2b) around at least the antenna circuit-shaped part (antenna circuit part 35) are bonded together with the adhesive 2c. It becomes the process of peeling.
In addition, since heat is not applied at this stage, the adhesive 2c can be peeled from the slightly adhesive plastic film 3. By performing this peeling, the adhesive 3b is exposed around each antenna circuit portion 35. By performing the above, as shown in FIG. 8C, on the slightly adhesive plastic film 3, a plurality (eight in the illustrated example) of antenna circuit portions 35 and a frame-like body surrounding the antenna circuit portions 35 are surrounded. 35a will be formed.

Next, a rectangular cover film 4 composed of a plastic sheet 4a and a thermoplastic adhesive 4b as shown in the partial cross-sectional view of FIG. 9B is prepared. Then, the positioning holes 41 arranged at the four corners of the cover film 4 and a plurality (eight places in the illustrated example) of the holes 42 arranged at positions corresponding to the antenna feeding portion 32 of the final product are formed by punching. .
9A, the surface of the adhesive 4b of the cover film 4 is the copper foil film 2a side of the component shown in FIG. 8C obtained in step S7 (that is, the surface on which each antenna circuit portion 35 is formed). Pasted on the other side) and thermally laminated (step S8). That is, in this step S8, the process of bonding the cover film 4 to one surface side of the film substrate (the plastic film with copper foil 2) is performed. Since the adhesive 4b has thermoplasticity, each antenna circuit part 35 is fixed to the cover film 4 by performing the thermal lamination. In addition, when affixing the cover film 4, it affixes so that each positioning hole 41 and each positioning hole 11a may mutually correspond.
What was obtained by the above process is shown to FIG. 10A. Further, FIG. 10B shows a stacked configuration in the vicinity of the antenna circuit unit 35. In addition, since the adhesive 2c and the adhesive 3b are not fixed by heat lamination, the slightly adhesive plastic film 3 can be peeled at room temperature as will be described later.

As described in step S1 with reference to FIG. 2C, the gold plating 33 is formed in the same shape as the hole 11 of the masking film, which is about 0.5 mm larger than the hole 42 of the cover film 4. Therefore, as shown in FIG. 10C, even if the cover film 4 is slightly misaligned, portions other than the gold plating 33 are not exposed from the hole 42.

In addition, the said thermal lamination can be performed using heating sources, such as an iron, for example. As the plastic sheet 4a, for example, polyethylene terephthalate (PET), polyimide, polypropylene, or polyethylene naphthalate can be employed, and the thickness is preferably 20 μm to 100 μm.

Next, as shown in FIG. 11A, each antenna circuit portion 35 is formed from a laminate sandwiched between the slightly adhesive plastic film 3 and the cover film 4 as shown in FIGS. 10B and 10C. Is peeled off (step S9). At this time, the plastic film with copper foil 2 including the antenna circuit portion 35 and the cover film 4 are completely fixed to each other by the thermal lamination performed in step S8, so that they are not peeled off. The laminated body thus obtained is shown in FIG. 11B, and the laminated structure at the position of the antenna circuit unit 35 is shown in FIG. 11C. In addition, FIG. 11D shows a stacked configuration of the antenna circuit portion 35 at the position of the gold plating 33.

Next, a rectangular base film 5 as shown in FIGS. 12A and 12B is prepared. It should be noted that FIG. 12A is the reverse of FIG. 11B. As shown in FIG. 12A, the base film 5 has positioning holes 51 formed at the four corners thereof, and a plastic sheet alone (preferably PET) or with a plastic sheet as shown in FIG. 12B. It is composed of an adhesive sheet.
As shown in FIGS. 12A, 12C, and 12D, the base film 5 is attached to the adhesive 2c side of the laminate obtained in step S9. At that time, the positioning holes 41 and the positioning holes 51 are pasted while being positioned so as to coincide with each other. After pasting in this way, thermal lamination is performed (step S10). Thereby, the base film 5 is fixed to the cover film 4. Accordingly, the periphery of the antenna circuit portion 35 including the gold plating 33 portion is sandwiched between the cover film 4 and the base film 5 so as to be tightly surrounded. The laminated structure of the obtained laminated body is shown in FIGS. 12C and 12D. Note that FIGS. 12C and 12D are upside down from FIGS. 11C and 11D.

Next, as shown in FIG. 13A, the pair of reinforcing plates 6 is attached to the surface of the laminate obtained in step S10 on the side of the base film 5 while being positioned by the positioning holes 6h (step S11).
As shown in the partial cross-sectional view of FIG. 13B, these reinforcing plates 6 are obtained by applying an adhesive 6b to one surface of a plastic sheet (PET is preferable) 6a, and are elongated along one direction as shown in FIG. 13A. Positioning holes 6h for having the above-mentioned positioning are formed at the both ends of the same shape. FIG. 13C shows a state where these reinforcing plates 6 are attached, and FIG.
The reason why the reinforcing plates 6 are attached in this manner is to reinforce them in consideration of using a spring probe (not shown) when connecting to the substrate. That is, it is to reinforce the power feeding portion (the gold plating 33 portion) that becomes the connection portion of the film antenna 7 and improve the strength so that the power feeding portion does not bend. In addition, as the adhesive 6b, what has the adhesive force of about 5 N / cm can be used.

Finally, by using each

positioning hole

21, 41, 51 formed in the laminate obtained in step S11 and set in a cutting device (not shown), press cutting or laser cutting is performed. 14A to 14C, a plurality of film antennas 7 (eight in the illustrated example) having the same shape are completed (step S12).
14A is a perspective view seen from the cover film 4 side, FIG. 14B is a perspective view seen from the same side, and FIG. 14C is a perspective view seen from the base film 5 side. In FIG. 14C, the reinforcing plate 6 is disposed in the uppermost layer and reinforces the power feeding portion.

Below, it demonstrates further focusing on the characteristic of the film antenna 7 manufactured by the manufacturing method of this embodiment.
FIG. 15A is a plan view of the film antenna 7 manufactured by the manufacturing method of the present embodiment as viewed from the cover film 4 side. FIG. 15B is a diagram schematically showing a laminated configuration of the film antenna 7, and FIG. 15C is a perspective view thereof. As shown in FIGS. 15B and 15C, the film antenna 7 is laminated in the order of the cover film 4, the antenna circuit unit 35 (plastic film with copper foil 3), and the base film 5. The reinforcing plate 6 is further laminated below them.

FIG. 15E is a partially enlarged perspective view of a portion C in FIG. 15C. Conventionally, this portion requires the plating lead 2aa as shown in FIG. 16B, but the film antenna 7 manufactured by the manufacturing method of the present embodiment does not need it as shown in FIG. 15E. . In other words, in the film antenna 7 of the present embodiment, the copper foil film 2a does not extend to the end of the antenna as the plating lead 2aa as shown in FIG. 16B, and includes the copper foil film 2a as shown in FIG. 15D. The antenna circuit unit 35 is surrounded and sealed by the cover film 4 and the base film 5. Therefore, the antenna characteristics are not deteriorated and corrosion can be prevented. As shown in FIG. 15D, the gold plating 33 is exposed to the outside only from the antenna power supply portion corresponding hole 42.

Further, as can be seen from FIG. 15D, the area of the gold plating 33 is larger than the size of the antenna feeding portion corresponding hole 42 of the cover film 4, so that a slight displacement of the cover film 4 can be allowed. On the other hand, according to the conventional manufacturing method, as shown in FIGS. 16A and 16B, the size of the region of the gold plating 33 is the same as the size of the hole of the cover film 4 and cannot cope with a large positional deviation.
In the embodiment described above, it has been described that generally inexpensive PET is suitable as the plastic sheet used for the reinforcing plate 6, but of course, the same effect can be obtained even if polyimide is used although it is somewhat expensive. it can.

In the above-described embodiment, the antenna is used for a small wireless electronic device such as a mobile phone or a PDA. However, the present invention is not limited to this, and the television, facsimile, video deck, digital having a wireless function is not limited thereto. You may employ | adopt this invention to the antenna used for a camera, a video camera, etc. Further, the present invention may be applied to an antenna in a card used for RFID (Radio Frequency IDentification).

The outline of the film antenna of the present embodiment described above and the manufacturing method thereof will be summarized below.
(1) The film antenna manufacturing method according to the present embodiment is: a film substrate (a plastic film 2 with a copper foil) provided with a first conductive layer (a copper foil film 2a) on one surface of a resin film (plastic sheet 2b). A step of attaching a temporarily fixing film (slightly adhesive plastic film 3) to the other surface of the film (step S2); and removing the plating power supply unit (power supply unit 32) on the one surface side of the film substrate. A step of bonding the masking film 1 formed with the plating process holes 11 so as to cover the first conductive layer (step S4); and applying a voltage to the first conductive layer from the power supply part for the plating process, Forming a second conductive layer (gold plating 33) by plating on the first conductive layer exposed from the plating hole (step S5); A step of peeling the king film (step S6); a step of cutting the film substrate into the shape of the antenna circuit portion 35 including the second conductive layer (step S7); and at least the periphery of the antenna circuit portion A step of peeling the first conductive layer and the resin film from the temporarily fixed film (step S7); a step of bonding a cover film 4 to the one surface side of the film substrate (step S8); and the antenna A step of fixing the circuit portion to the cover film (step S8); a step of peeling the temporary fixing film from the film substrate (step S9); and the cover film 4 and the base film 5 between them, The antenna circuit part is sandwiched and bonded so that at least the periphery of the first conductive layer is surrounded tightly. Process (step S10); comprises.

(2) In the method for manufacturing a film antenna according to (1), the temporary fixing film, the cover film, and the base film have a surface area larger than that of the film substrate. That is, the area of the slightly adhesive plastic film 3, the cover film 4, and the base film 5 is larger than that of the plastic film 2 with copper foil by two paste margins 31.
(3) The method for manufacturing a film antenna according to (1) further includes a step of bonding a reinforcing plate 6 to a surface of the base film opposite to a surface to be bonded to the film substrate.

(4) The film antenna according to the present embodiment: a first conductive layer (copper foil film 2a) laminated on one surface of a resin film (plastic sheet 2b), and at least a part of the first conductive layer A film substrate (plastic film 2 with copper foil) provided with an antenna circuit portion 35 having a second conductive layer (gold plating 33) laminated thereon; affixed to the one surface of the film substrate with an adhesive A cover film 4; and a base film 5 attached to the other surface of the film substrate via an adhesive; and at least the periphery of the first conductive layer of the antenna circuit portion is the cover film. And is tightly enclosed between the base films.

(5) The film antenna according to (4), further including a reinforcing plate 6 bonded to a surface of the base film opposite to a surface bonded to the resin film.

The present invention can be suitably applied to antennas of small wireless electronic devices such as mobile phones and portable information terminals, and antennas in information devices such as televisions, facsimiles, video decks, digital cameras, and video cameras.

DESCRIPTION OF SYMBOLS 1 Masking film 1a Base material 1b Adhesive 11 Plating hole 12 Notch 2 Plastic film with copper foil (film substrate)
2a Copper foil film (first conductive layer)
2b Plastic sheet (resin film)
2c Adhesive 3 Slightly adhesive plastic film (temporary fixing film)
3a Plastic sheet base material 3b Adhesive 21 Positioning hole 31 Paste allowance 32 Power supply part for plating process 33 Gold plating (second conductive layer)
34 Slit 35 Antenna Circuit Part 4 Cover Film 4a Plastic Sheet 4b Adhesive 41 Positioning Hole 42 Antenna Feeder Corresponding Hole 5 Base Film 51 Positioning Hole 6 Reinforcement Plate 6a Plastic Sheet 6b Adhesive 7 Film Antenna

Claims

Bonding the temporary fixing film to the other surface of the film substrate provided with the first conductive layer on one surface of the resin film;
Bonding a masking film having a plating treatment hole formed on the one surface side of the film substrate so as to cover the first conductive layer except for the plating treatment power supply portion;
Applying a voltage to the first conductive layer from the power supply unit for plating, and forming a second conductive layer by plating on the first conductive layer exposed from the hole for plating;
Peeling the masking film from the film substrate;
Cutting the film substrate into the shape of an antenna circuit portion including the second conductive layer;
Peeling the first conductive layer and the resin film at least around the antenna circuit portion from the temporary fixing film;
Bonding a cover film to the one surface side of the film substrate;
Peeling the temporary fixing film from the film substrate;
Sandwiching and bonding the cover film and the base film so that at least the periphery of the first conductive layer of the antenna circuit portion is tightly enclosed between them;
A method of manufacturing a film antenna, comprising:
The method for manufacturing a film antenna according to claim 1, wherein the temporarily fixed film, the cover film, and the base film have a surface area larger than that of the film substrate.
The method for manufacturing a film antenna according to claim 1, further comprising a step of bonding a reinforcing plate to a surface of the base film opposite to a surface to be bonded to the film substrate.
A film substrate provided with an antenna circuit portion having a first conductive layer laminated on one surface of the resin film and a second conductive layer laminated on at least a part of the first conductive layer;
A cover film affixed to the one surface of the film substrate via an adhesive;
A base film attached to the other surface of the film substrate via an adhesive;
With
A film antenna, wherein at least the periphery of the first conductive layer of the antenna circuit portion is sandwiched and tightly surrounded by the cover film and the base film.
The film antenna according to claim 4, further comprising a reinforcing plate bonded to a surface of the base film opposite to a surface bonded to the resin film.