WO2017149941A1

WO2017149941A1 - Capacitance sensor, manufacturing method therefor, and molded article equipped with capacitance sensor

Info

Publication number: WO2017149941A1
Application number: PCT/JP2017/000731
Authority: WO
Inventors: 橋本　孝夫
Original assignee: 日本写真印刷株式会社
Priority date: 2016-03-01
Filing date: 2017-01-12
Publication date: 2017-09-08

Abstract

[Problem] To provide a bendable capacitive touch sensor wherein the electrodes have low resistance and an excellent visual property, a method for manufacturing this capacitive touch sensor, and a molded article equipped with this capacitive touch sensor. [Solution] A capacitance sensor characterized by being equipped with a transparent base film, a first conductive part formed on a first primary surface of the base film, and a second conductive part formed on a second primary surface of the base film, wherein the first conductive part has two or more first electrode patterns, which comprise black conductive thin wires that are opaque and have a reflectance of 2% or less, and blank parts partitioned by the black conductive thin wires, and which extend in a first direction and are arranged in a second direction orthogonal to the first direction, the second conductive part has two or more second electrode patterns, which comprise black conductive thin wires that are opaque and have a reflectance of 2% or less, and blank parts partitioned by the black conductive thin wires, and which extend in the second direction and are arranged in the first direction, and the black conductive thin wires are configured by including metal particles and a conductive blacking agent in a photosensitive resin.

Description

Capacitance sensor and manufacturing method thereof, molded product with capacitance sensor

The present invention relates to a bendable electrostatic capacitance touch sensor having a low resistance and excellent visibility, and a method of manufacturing the same.

A film sensor used for a capacitive touch panel (hereinafter referred to as a capacitive sensor) is a sensor that senses a change in capacitance (charge) between X and Y electrodes that occurs when a finger touches the surface of the touch panel. This is a mechanism for recognizing the position.

Conventionally, in a capacitance sensor, the electrodes are made of ITO (indium tin oxide) so that the X and Y electrodes arranged in a matrix are not conspicuous. However, electronic devices equipped with touch panels are currently mainly applied to small sizes of mobile devices such as smartphones (high-function mobile terminals), but are applied to digital signage (electronic signage) etc. It is thought that the increase in size will progress. In such future trends, conventional ITO (Indium Tin Oxide) electrodes have a large resistance, and as the application size increases, the current transfer speed between the electrodes decreases, and the response speed (contact the fingertip). The time until the position is detected after that is delayed.

Therefore, in order to solve this problem, a technology (so-called metal mesh electrode) of a technique (so-called metal mesh electrode) in which a metal thin film such as gold, silver, or copper having a low resistance is finely processed and a metal thin wire having a line width that is not visually recognized by the toucher. Development is underway. For example, Patent Documents 1 to 3 are known as capacitance sensors using metal fine wires as electrodes.

Special table 2011-530112 gazette JP 2012-079238 A JP 2011-175628 A

However, when a metal mesh electrode is used for the capacitance sensor, the metal color reflectance of the metal thin wire constituting the electrode is high, and visibility becomes a problem.
In order to suppress reflection of the metal mesh electrode, there is a measure to attach a black oxide film to the surface of the metal mesh electrode, but in this case, the price is expensive. Further, a black mesh electrode made of chromium and provided with an oxide film is not only expensive, but is also not easily etched during patterning. Furthermore, since an oxide film can also be attached to the wiring from the electrode, the terminal surface is poor in conductivity and is not suitable for taking out the terminal.

The above digital signage is a tool that sends information and images to many people at once in complex commercial facilities, public facilities, etc., but the installation area has been limited due to the recent increase in screen size. With the development of curved displays, digital signage that can replace printed materials such as posters attached to cylinders has become possible. However, when a metal mesh electrode formed by finely processing a metal thin film is used for the capacitance sensor, it has been difficult to apply it to a curved display or a foldable display because of fear of disconnection or the like. For the same reason, it has been difficult to apply to curved molded products such as automobile interiors.

Therefore, the present invention has been made in consideration of such problems, and the electrode has a low resistance, excellent visibility, a foldable capacitance touch sensor, a manufacturing method thereof, and a molded product with the capacitance sensor. The purpose is to provide.
In the present specification, “bendable” includes any meaning of being bent (bendable) and capable of being folded in two (foldable).

In order to achieve the above object, the present invention is configured as follows.

The capacitance sensor of the present invention includes a transparent base film, a first conductive portion formed on the first main surface of the base film, a second conductive portion formed on the second main surface of the base film, Each of the first conductive portions is made of a black conductive thin wire that is opaque and has a reflectance of 2% or less, and a blank portion partitioned by the black conductive thin wire, and extends in the first direction. Two or more first electrode patterns arranged in a second direction orthogonal to the first conductive pattern, and the second conductive part is opaque and divided by the black conductive thin line and the black conductive thin line each having a reflectance of 2% or less It consists of a blank portion, extends in the second direction, and has two or more second electrode patterns arranged in the first direction, and the black conductive fine wire is formed of metal particles and conductive black in the photosensitive resin. It has a gist in that it contains an agent.
As described above, the first electrode pattern and the second electrode pattern are made of opaque black conductive wires having a reflectance of 2% or less and blank portions partitioned by the black conductive wires, so that the reflection of the conductive wires can be suppressed. And has excellent visibility. Moreover, since the black electroconductive thin wire is comprised including the metal particle and the electroconductive black agent in photosensitive resin, it is low resistance and can be bent.

The metal particles are preferably one or more metal particles selected from silver, copper, and aluminum. These are suitable for industrial production in terms of conductivity and cost.

The conductive black agent is preferably one or more conductive black agents selected from carbon nanotubes, fullerenes, graphene, graphite, and doped amorphous carbon. These are suitable for opacifying the conductive thin wires.

The photosensitive resin is preferably a photosensitive resin containing a photopolymerization initiator. This is because the photosensitive resin containing the photopolymerization initiator is excellent in flexibility.

It is preferable that the first electrode pattern formed on the first main surface of the base film and the second electrode pattern formed on the second main surface of the base film are respectively covered with a flexible protective film. By forming a flexible protective film on both sides, the bendability of the capacitance sensor is improved.

In the capacitance sensor of the present invention, the first conductive portion further includes a black conductive fine wire made of the same material as that of the first electrode pattern and a blank portion partitioned by the black conductive thin wire. Black conductive material having a plurality of first dummy patterns arranged in a gap between the one electrode patterns and electrically insulated from the first electrode pattern, wherein the second conductive portion is the same material as the second electrode pattern It has a plurality of second dummy patterns which are composed of a fine line and a blank portion partitioned by the black conductive fine line and are arranged in a gap between adjacent second electrode patterns and are electrically insulated from the second electrode pattern. It is preferable.
The first dummy pattern and the second dummy pattern can be complemented so that the gap between the first electrode patterns and the gap between the second electrode patterns are not conspicuous. That is, it can appear as if the blank portion partitioned by the black conductive thin wire in the first electrode pattern or the second electrode pattern is continuously present in the gap.

The first electrode pattern and the first dummy pattern formed on the first main surface of the base film, and the second electrode pattern and the second dummy pattern formed on the second main surface of the base film are formed by a flexible protective film. Each is preferably coated. Even in the case of having a dummy pattern, the bendability of the capacitance sensor is improved by forming a flexible protective film on both sides.

The molded product with a capacitance sensor of the present invention is summarized in that it includes a resin molded product having a curved surface and the above-described capacitance sensor integrated along the curved surface of the molded product. Have.
In the molded article with a capacitance sensor of the present invention, the first electrode pattern and the second electrode pattern of the capacitance sensor are separated by a black conductive thin wire having a reflectance of 2% or less and the black conductive thin wire. Since it consists of a blank part, reflection of the electroconductive fine wire of an electrostatic capacitance sensor can be suppressed, and it is excellent in visibility. In addition, since the black conductive thin wire of the capacitance sensor is configured by containing metal particles and a conductive black agent in the photosensitive resin, it can be bent with low resistance and has a curved surface. Suitable for integration.

In addition, the method for producing a capacitance sensor of the present invention includes a support film having releasability, and a photosensitive conductive material provided on the support film and containing metal particles and a conductive black agent in a photosensitive resin. A photosensitive conductive resin laminate including a resin layer is used, and the photosensitive conductive resin layer surface of the photosensitive conductive resin laminate is laminated on the first main surface and the second main surface of the transparent base film, respectively. Laminating step, exposure step of exposing both sides of the double-sided laminate obtained in the previous step through a photomask, and developing the photosensitive conductive resin layer after exposure and after peeling of the support film, And a developing step for forming the first conductive portion and the second conductive portion of the capacitance sensor.
The method for manufacturing a capacitance sensor according to the present invention includes a first electrode pattern and a second electrode pattern that are capable of suppressing reflection of a conductive thin wire, have excellent visibility, and have low resistance and bendability. Since it can be formed by a simple method of forming by a photo process using the above photosensitive conductive resin laminate, it is suitable for industrial production.

As described above, according to the capacitance sensor, the method for manufacturing the same, and the molded product with the electrostatic sensor according to the present invention, the first electrode pattern and the second electrode pattern are opaque and have a black conductivity of 2% or less. Since it consists of the blank part partitioned off by a conductive fine wire and the said black conductive fine wire, reflection of a conductive thin wire can be suppressed and it is excellent in visibility.
Moreover, since the said black electroconductive fine wire is comprised including the metal particle and the electroconductive black agent in photosensitive resin, it is low resistance and can be bent.

It is a disassembled perspective view which abbreviate | omits and shows some examples of the capacitive sensor for capacitive touch panels which concerns on this invention. It is sectional drawing which abbreviate | omits and shows an example of the electrostatic capacitance sensor which concerns on this invention. It is explanatory drawing which expanded and showed a part about an example of a mesh pattern. It is explanatory drawing which expanded and showed the part about the other example of a mesh pattern. It is explanatory drawing which expanded and showed the part about the other example of a mesh pattern. It is a disassembled perspective view which abbreviate | omits and shows the other example of the electrostatic capacitance sensor which concerns on this invention. It is a disassembled perspective view which abbreviate | omits and shows the other example of the electrostatic capacitance sensor which concerns on this invention. It is sectional drawing which abbreviate | omits and shows a part other than the electrostatic capacitance sensor which concerns on this invention. It is sectional drawing which shows an example of the photosensitive conductive resin laminated body used for the manufacturing method of the electrostatic capacitance sensor which concerns on this invention. It is sectional drawing which shows an example of the lamination process in the manufacturing method of the electrostatic capacitance sensor which concerns on this invention. It is sectional drawing which shows an example of the exposure process in the manufacturing method of the electrostatic capacitance sensor which concerns on this invention. It is sectional drawing which shows an example of the image development process in the manufacturing method of the electrostatic capacitance sensor which concerns on this invention. It is a figure which shows the usage example (surface cover of the digital signage for cylinders) of the electrostatic capacitance sensor which concerns on this invention. It is a figure which shows the usage example (automobile interior molded product) of the electrostatic capacitance sensor which concerns on this invention. It is explanatory drawing which expanded and showed the part about the other example of a mesh pattern. It is sectional drawing which shows an example in which the flexible protective film was formed on both surfaces of the electrostatic capacitance sensor. It is sectional drawing which shows another example which formed the flexible protective film on both surfaces of the electrostatic capacitance sensor.

Hereinafter, embodiments according to the present invention will be described in more detail with reference to the drawings. It should be noted that the dimensions, materials, shapes, relative positions, etc. of the parts and portions described in the embodiments of the present invention are not intended to limit the scope of the present invention only to those unless otherwise specified. This is just an illustrative example.

[First Embodiment]
<Configuration of capacitance sensor>
As shown in FIGS. 1 and 2, the capacitance sensor 1 according to the first embodiment includes a transparent base film 12, a first conductive portion 14 a formed on the first main surface 12 a of the base film 12, and And a second conductive portion 14b formed on the second main surface 12b of the base film 12.

(Base film)
The base film 12 is a resin film having a transmittance of 90% or more. Examples of the resin include polyesters such as polyethylene terephthalate (PET), polylactic acid (PLA), and polyethylene naphthalate (PEN), polyethylene (PE), polypropylene (PP), polystyrene, EVA, cycloolefin polymer (COP), Polyolefins such as cyclic olefin copolymer (COC), vinyl resin, polycarbonate (PC), polyamide, polyimide (PI), acrylic resin (PMMA), triacetyl cellulose (TAC), and the like can be used.

The thickness of the base film 12 is preferably 5 to 350 μm, and more preferably 30 to 150 μm. If it is in the range of 5 to 350 μm, a desired visible light transmittance can be obtained, and handling is easy. Moreover, the base film 12 may be a single layer or a laminate in which two or more layers are bonded. Furthermore, the base film 12 may have a 1 / 4λ phase difference film, for example, a stretched COP in its configuration. The base film 12 can also be a piezoelectric film that is uniaxially stretched from the polylactic acid film described above and does not generate pyroelectricity.
Further, the base film 12 may be coated with a resin on one or both of the first main surface 12a and the second main surface 12b. For example, it is a coating of a transparent film that does not transmit the exposure wavelength.

(First conductive part and second conductive part)
As shown in FIG. 1, the first conductive portion 14 a and the second conductive portion 14 b include a portion that requires perspective (first sensor portion 24 a and second sensor portion 24 b) and a portion that does not require perspective (first terminal). Wiring portion 34a and second terminal wiring portion 34b). The external shape of the capacitance sensor 1 has a rectangular shape in plan view, and the external shapes of the first sensor unit 24a and the second sensor unit 24b also have a rectangular shape.

The first sensor portion 24a of the first conductive portion 14a is composed of a black conductive thin wire 16 which is opaque and has a reflectance of 2% or less, and a blank portion 17 partitioned by the black conductive thin wire 16 in a first direction (FIG. 1). And two or more first electrode patterns 25a arranged in a second direction (Y direction in FIG. 1) orthogonal to the first direction. FIG. 2 is a cross-sectional view of one first electrode pattern 25a in the capacitance sensor of FIG. 1 cut in the length direction.

The second sensor portion 24b of the second conductive portion 14b is composed of a black conductive thin wire 16 which is opaque and has a reflectance of 2% or less and a blank portion 17 partitioned by the black conductive thin wire 16 in the second direction (FIG. 1). And two or more second electrode patterns 25b extending in the first Y direction and arranged in the first direction (X direction in FIG. 1). The second conductive portion 14 b is in a state where it is electrically insulated from the first conductive portion 14 a by the base film 12.

In the present embodiment, the pattern composed of the black conductive fine wires 16 and the blank portions 17 partitioned by the black conductive fine wires 16 is specifically a mesh pattern. That is, the outline of each mesh pattern is constituted by the black conductive thin wires 16, and the opening portion of each mesh pattern is constituted by the blank portion 17 surrounded by the black conductive fine wires 16 (see FIG. 1). Further, the first electrode pattern 25a and the second electrode pattern 25b are formed in such a pattern, thereby obtaining transparency.

By the way, it is preferable that the mesh pattern applied to the first electrode pattern 25a and the second electrode pattern 25b of the capacitance sensor 1 form an opening with a quadrangle as shown in FIG. 1 or other polygons. For non-polygonal ones, such as those with circular or elliptical openings, even if the openings are arranged as closely as possible, a thick outline is formed between the openings. This is because the thick part is noticeable and the light transmittance is reduced. Further, it can be configured by one type or a combination of a plurality of types among figures such as a triangle, a quadrangle, and a hexagon.

FIGS. 3 to 5 are enlarged views of examples of mesh patterns applicable to the present invention.
The mesh pattern shown in FIG. 3 has a quadrangular shape as a nucleus and is continuous in the X direction and the Y direction, and corresponds to the first electrode pattern 25a and the second electrode pattern 25b shown in FIG. However, although both the first electrode pattern 25a and the second electrode pattern 25b shown in FIG. 1 have a quadrangle as a nucleus, the dimensions of the nucleus are different. More specifically, the size in which a plurality of nuclei of the first electrode pattern 25a are arranged in the Y direction corresponds to one nucleus of the second electrode pattern 25b. The mesh pattern shown in FIG. 4 has a hexagonal core and is continuous in the X direction, Ya direction, and b direction. The mesh pattern shown in FIG. 5 has a ladder shape as a nucleus and is continuous in the X and Y directions.

Of the quadrangular shapes, those having a square as a core are particularly preferable because the mesh pattern is less likely to be recognized as a streak compared to other polygonal shapes. That is, when a regularly continuous pattern with a certain shape as a nucleus is seen, the outline (black conductive thin line 16) tends to appear as a continuous streak along the continuous direction of the nucleus. For example, in the case of a hexagonal core, the line of black conductive thin wires 16 along the continuous direction becomes zigzag, so that it appears thicker by the amplitude of the zigzag, and as a result, the black conductive thin wires It appears that the line width of 16 is expanded. In this respect, in the case where the square is continuous as a nucleus, since the linear shape of the black conductive thin wire 16 along the continuous direction is straight, there is no concern that it may appear thicker than the original width, so its existence is recognized. It is hard to be done and the mesh pattern is not conspicuous.

Also, in the case where the rectangle is continuous as a nucleus, the long side direction and the short side direction of this rectangle have different pitches, so when looking at the whole, the short side direction with a shorter pitch is darker than the long side direction. It appears and flickers and tends to appear flickering. However, when the square is continuous as a nucleus, such streaks do not appear and are not noticeable. The square is not limited to a completely square, but includes a chamfered square.

The “polygon” in the present specification includes not only a geometrically perfect polygon but also a “substantial polygon” in which a slight change is made to the perfect polygon. And Examples of minor changes include the addition of minute point elements / line elements as compared to the mesh, and partial loss of each side (black conductive fine wire 16) constituting the mesh. For example, in the example shown in FIG. 1, the presence of the linear protrusion 40 facing the gap 20 between the first electrode patterns 25a obscures the boundary between the gap 20 and the first electrode pattern 25a and does not stand out. I am doing so.

As for the outline width of the mesh pattern, the lower limit is preferably 1 μm or more, 3 μm or more, 4 μm or more, or 5 μm or more, and the upper limit is preferably 15 μm, 10 μm or less, 9 μm or less, or 8 μm or less. When the line width is less than the above lower limit value, the conductivity becomes insufficient, so that the detection sensitivity of the touch panel becomes insufficient. On the other hand, if the upper limit is exceeded, the transparency may deteriorate.

The aperture ratio of the mesh pattern is preferably 85% or more from the viewpoint of visible light transmittance, more preferably 90% or more, and most preferably 95% or more. An aperture ratio is the ratio which a translucent part accounts to the whole.

The black conductive fine wires 16 of the first electrode pattern 25a and the second electrode pattern 25b are configured by containing metal particles and a conductive black agent in a photosensitive resin. Therefore, while being lower in resistance than the ITO electrode, it is possible to bend, which is difficult with the conventional metal mesh due to the possibility of disconnection or the like.

The metal particles used for the black conductive fine wire 16 are made of metal such as silver, copper, aluminum, nickel, gold, tin, zinc, stainless steel, aluminum based on titanium oxide, zinc oxide, indium oxide, tin oxide, etc. Metal oxide systems doped with nickel, antimony oxide, insulating and inexpensive mica, calcium carbonate, metal coated systems in which glass beads are coated with a metal such as aluminum or nickel, etc., but particularly silver, copper and aluminum One or more metal particles selected from the above are preferable from the viewpoint of conductivity and cost.

By using a conductive black agent for the black conductive fine wire 16, the conductive fine wire can be made opaque. As a result, the reflection of the conductive thin wire can be suppressed, and the visibility is excellent.
Examples of the conductive blacking agent used for the black conductive thin wire 16 include carbon black, carbon nanotube, fullerene, graphene, graphite, doped amorphous carbon, and a mixture thereof. In particular, carbon nanotube, fullerene, graphene, graphite And at least one conductive black agent selected from doped amorphous carbon. The size of the conductive black agent is preferably 0.5 μm or less. More preferred are graphene, carbon nanotubes, and fullerenes having high electrical conductivity.
In addition, as general black agents, there are organic colorants such as reactive dyes, azo dyes, nigrosines, perylene pigments, mixed phase pigments, etc. that have no electrical conductivity. There is a risk of impairing the conductivity obtained with the particles.

Examples of the photosensitive resin used for the black conductive fine wire 16 include photosensitive resins such as acrylic, alicyclic epoxy, acrylic acrylate, urethane acrylate, epoxy acrylate, polyester acrylate, vinyl ether, and novolac. Among them, a photosensitive resin containing a photopolymerization initiator is particularly preferable from the viewpoint of excellent flexibility. As the photopolymerization initiator, photopolymerization initiators such as benzophenone, acetophenone, thioxanthone, benzyl, and azo can be used. A sensitizer may be added.

(Other configurations)
As described above, the first conductive portion 14a and the second conductive portion 14b include a portion that requires perspective (the first sensor portion 24a and the second sensor portion 24b) and a portion that does not require perspective (the first terminal wiring portion). 34a and second terminal wiring portion 34b) (see FIG. 1).

A plurality of first terminals (not shown) are arranged in the central portion in the longitudinal direction on the peripheral portion of one side of the capacitance sensor 1 in the first terminal wiring portion 34a. The first terminal wiring pattern 35a is led out from one end of each first electrode pattern 25a, routed toward the first terminal, and electrically connected to the corresponding first terminal 64a. Yes. In addition, a plurality of second terminals (not shown) are arranged in the center in the longitudinal direction at the peripheral portion of one side of the capacitance sensor 1 in the second terminal wiring portion 34b. And the 2nd terminal wiring pattern 35b is derived | led-out from either one end of each 2nd electrode pattern 25b, it was drawn around toward the said 2nd terminal, and it electrically connected to the corresponding 2nd terminal, respectively. Yes.

The first terminal wiring pattern 35a and the second terminal wiring pattern 35b can be formed of the same material as the first electrode pattern 25a and the second electrode pattern 25b. The first terminal wiring pattern 35a and the second terminal wiring pattern 35b are configured to have a width of 25 μm or more and 500 μm or less, a length of 10 mm or more, and a resistance of 300 ohms or less per 10 mm, preferably 100 ohms or less.

And when this electrostatic capacitance sensor 1 is comprised as a touch panel, the cover member laminated | stacked on either main surface side of the electrostatic capacitance sensor 1 other than the above-mentioned electrostatic capacitance sensor 1, and electrostatic capacitance An FPC electrically connected to the sensor 1 and an IC circuit arranged on the FPC are provided. By bringing the fingertip into contact with the cover member, signals from the first electrode pattern 25a and the second electrode pattern 25b facing the fingertip are transmitted to the IC circuit. The IC circuit calculates the position of the fingertip based on the supplied signal.

<Molded product with capacitance sensor>
As a use of the capacitance sensor 1 as described above, the capacitance sensor 1 has a large size and is suitable for a use in which it is bent. For example, the surface cover 201a (see FIG. 13) of the digital signage 201 attached to the column 200 of a public facility or the like as shown in the column of the problem, or the automobile interior molded product 300 (see FIG. 14).
These are molded products with a capacitance sensor including resin molded

products

201a and 300 having curved surfaces and a capacitance sensor 1 integrated along the curved surfaces of the molded

products

201a and 300.

In order to integrate the capacitance sensor 1 into the resin molded

products

201a and 300 having curved surfaces, an insert molding method may be used. Specifically, the electrostatic capacitance sensor 1 is inserted and arranged in a molding die so that the surface on the touch side is integrated with the molding resin, and vacuum suction is performed through a suction hole provided in the die. After placing the capacitance sensor 1 along the cavity surface, the mold is closed, and the mold resin in a molten state is injected and filled in the cavity. As a result, a resin molded product is obtained, and at the same time, the capacitance sensor 1 is coated along the surface thereof.

Examples of the molding resin include general-purpose resins such as polystyrene resin, polyolefin resin, ABS resin, and AS resin. General engineering resins such as polyphenylene oxide / polystyrene resins, polycarbonate resins, polyacetal resins, acrylic resins, polycarbonate-modified polyphenylene ether resins, polyethylene terephthalate resins, polybutylene terephthalate resins, ultrahigh molecular weight polyethylene resins, and polysulfone resins, Super engineering resins such as polyphenylene sulfide resins, polyphenylene oxide resins, polyacrylate resins, polyetherimide resins, polyimide resins, liquid crystal polyester resins, and polyallyl heat-resistant resins can also be used.

Further, an adhesive layer may be provided on the surface of the capacitance sensor 1 that is in close contact with the resin molded product. As the adhesive layer, a heat-sensitive or pressure-sensitive resin suitable for the material of the resin molded product is appropriately used. For example, when the material of the resin molded product is a polyacrylic resin, a polyacrylic resin may be used. In addition, when the material of the resin molded product is a polyphenylene oxide / polystyrene resin, a polycarbonate resin, a styrene copolymer resin, or a polystyrene blend resin, a polyacrylic resin, a polystyrene resin having an affinity for these resins, A polyamide resin or the like may be used. Furthermore, when the material of the resin molded product is a polypropylene resin, chlorinated polyolefin resin, chlorinated ethylene-vinyl acetate copolymer resin, cyclized rubber, and coumarone indene resin can be used.

<Manufacturing method of capacitance sensor>
Hereinafter, a method for manufacturing the capacitance sensor according to the present embodiment will be described.
This production method is a photosensitive film comprising a support film 22 having peelability and a photosensitive conductive resin layer 23 provided on the support film 22 and containing metal particles and a conductive black agent in the photosensitive resin. The surface of the photosensitive conductive resin layer 23 of the photosensitive conductive resin laminate 60 is formed on the first main surface 12a and the second main surface 12b of the transparent base film 12 using the conductive conductive resin laminate 60 (see FIG. 9). Laminating step (see FIG. 10), and an exposure step (see FIG. 11) in which double-sided laminate 110 obtained in this step is exposed on both sides through

photomasks

117a and 117b, and after exposure and And a developing step (see FIG. 12) for developing the photosensitive

conductive resin layers

123a and 123b after the

support films

122a and 122b are peeled off.

(Photosensitive conductive resin laminate)
As shown in FIG. 9, the photosensitive conductive resin laminate 60 has a photosensitive conductive resin layer 23 on a support film 22 having releasability. If necessary, a support film for the photosensitive conductive resin layer 23 is used. You may have further a protective film on the surface on the opposite side to 22 side.

The support film 22 is preferably transparent so as to transmit light emitted from the exposure light source. Examples of such a support film 22 include a polyethylene terephthalate film, a polyvinyl alcohol film, a polyvinyl chloride film, a vinyl chloride copolymer film, a polyvinylidene chloride film, a vinylidene chloride copolymer film, and a polymethyl methacrylate copolymer film. , Polystyrene film, polyacrylonitrile film, styrene copolymer film, polyamide film, cellulose derivative film and the like. As these films, those stretched as necessary can be used. The support film preferably has a haze of 5 or less. The thinner the support film is, the more advantageous in terms of image formation and economy, but it is preferably 10 μm to 30 μm in order to maintain the strength.

The photosensitive conductive resin layer 23 is for forming the black conductive fine wires 16 of the capacitance sensor 1, and the material thereof is as described in the description of the black conductive fine wires 16.

In the case of providing a protective film, a protective film that is sufficiently smaller than the support film 22 in terms of adhesion to the photosensitive conductive resin layer 23 and that can be easily peeled is selected. For example, a polyethylene film or a polypropylene film is preferable as the protective film.

As the method for producing the photosensitive conductive resin laminate 60 by sequentially laminating the support film 22, the photosensitive conductive resin layer 23 and, if necessary, a protective film, a known method can be adopted. For example, a composition used for forming the photosensitive conductive resin layer 23 is mixed with a solvent for dissolving the composition to obtain a uniform mixed solution. Next, the preparation liquid is applied onto the support film 22 using a bar coater or a roll coater, and then dried to laminate the photosensitive conductive resin layer 23 on the support film 22. Next, a protective film is laminated on the photosensitive conductive resin layer 23 as necessary. As described above, the photosensitive conductive resin laminate 60 can be manufactured.

(Lamination process)
First, as shown in FIG. 10, the photosensitive conductive resin laminate 60 is used, and the photosensitive properties of the photosensitive conductive resin laminate 60 are respectively formed on the first main surface 12 a and the second main surface 12 b of the transparent base film 12. The surfaces of the conductive resin layer 23 are stacked and stacked.
The resulting double-sided laminate 110 includes a transparent base film 12, an opaque first photosensitive conductive resin layer 123a and a first support film 122a formed by sequentially laminating on the first main surface of the base film 12, It has the opaque 2nd photosensitive conductive resin layer 123b and the 2nd support film 122b which were formed by laminating on the 2nd principal surface of base film 12 one by one.

The film thickness of the first photosensitive conductive resin layer 123a and the second photosensitive conductive resin layer 123b depends on the line width and resistance value of the black conductive thin wires 16 constituting the first electrode pattern 25a and the second electrode pattern. It is determined in the range of 0.5 to 10 μm.

(Exposure process)
Next, the double-sided laminate 110 is exposed. In this exposure processing, as shown in FIG. 11, the first photosensitive conductive resin layer 123a is irradiated with light toward the base film 12 so that the first photosensitive conductive resin layer 123a follows the first exposure pattern. First exposure processing to be exposed, and second photosensitive conductive resin layer 123b is irradiated with light toward the base film 12 to expose the second photosensitive conductive resin layer 123b along the second exposure pattern. Exposure processing is performed (simultaneous double-side exposure).

In the example of FIG. 11, while conveying the long double-sided laminate 110 in one direction, the first photosensitive conductive resin layer 123a is irradiated with the first light 111a (parallel light) through the first photomask 117a. The second photosensitive conductive resin layer 123b is irradiated with the second light 111b (parallel light) through the second photomask 117b. The first light 111a is obtained by converting the light emitted from the first light source 118a into parallel light by the first collimator lens 120a, and the second light 111b is emitted from the second light source 118b. It is obtained by converting the light into parallel light by the second collimator lens 120b in the middle. In the example of FIG. 11, the case where two light sources (the first light source 118a and the second light source 118b) are used is shown, but the light emitted from one light source is divided through the optical system to generate the first light. You may irradiate the 1st photosensitive conductive resin layer 123a and the 2nd photosensitive conductive resin layer 123b as 111a and the 2nd light 111b.

Exposure wavelength is semiconductor laser, metal halide lamp, g-line (wavelength 436 nm), h-line (wavelength 405 nm) i-line (wavelength 365 nm), broad (three wavelengths such as g, h, and i-line) high-pressure mercury lamp, KrF excimer laser Excimer laser such as (wavelength 248 nm), ArF excimer laser (wavelength 193 nm), F2 excimer laser (wavelength 157 nm), extreme ultraviolet light (wavelength 13.6 nm), electron beam, etc. are used.

In the first exposure process, as shown in FIG. 11, a first photomask 117a is disposed in close contact with the first photosensitive conductive resin layer 123a, for example, and a first light source disposed opposite to the first photomask 117a. The first photosensitive conductive resin layer 123a is exposed by irradiating the first light 111a from 118a toward the first photomask 117a. The first photomask 117a is composed of a glass substrate made of transparent soda glass and a mask pattern (first exposure pattern) formed on the glass substrate. Accordingly, the first exposure process exposes a portion of the first photosensitive conductive resin layer 123a along the first exposure pattern formed on the first photomask 117a.

Similarly, in the second exposure process, the second photomask 117b is disposed in close contact with the second photosensitive conductive resin layer 123b, for example, and the second light source 118b disposed opposite to the second photomask 117b is used for the second exposure. The second photosensitive conductive resin layer 123b is exposed by irradiating the second light 111b toward the photomask 117b. Similar to the first photomask 117a, the second photomask 117b includes a glass substrate formed of transparent soda glass and a mask pattern (second exposure pattern) formed on the glass substrate. . Accordingly, the second exposure process exposes a portion of the second photosensitive conductive resin layer 123b along the second exposure pattern formed on the second photomask 117b.

In the first exposure process and the second exposure process, the emission timing of the first light 111a from the first light source 118a and the emission timing of the second light 111b from the second light source 118b may be made simultaneously or differently. Also good. At the same time, the first photosensitive conductive resin layer 123a and the second photosensitive conductive resin layer 123b can be exposed simultaneously by one exposure process, and the processing time can be shortened.

And the 1st light 111a from the 1st light source 118a irradiated to the 1st photosensitive conductive resin layer 123a is interrupted by the opaque 1st photosensitive conductive resin layer 123a, and becomes the 2nd photosensitive conductive resin layer 123b. The second light 111b from the second light source 118b irradiated to the second photosensitive conductive resin layer 123b, which has not substantially reached, is blocked by the opaque second photosensitive conductive resin layer 123b, and the first photosensitive. The conductive resin layer 123a is not substantially reached. Therefore, different exposure patterns can be formed on both surfaces (front and back) of the transparent base film 12 arbitrarily and with high positional accuracy by the exposure process. Here, “substantially does not reach” indicates the case where the light does not reach or the amount of light that has reached the light but does not form an image by development. Therefore, “light arrives” indicates that light of a light amount reaching an image formed by development arrives.

(Development process)
Next, the photosensitive

conductive resin layers

123a and 123b after the

support films

122a and 122b are peeled are developed (see FIG. 12). In the development processing, when the photosensitive resin is a negative type, the solubility in the developer 140 is lowered when exposed, so that an exposed portion (the portion shown dark in the drawing) remains after development. On the other hand, when the photosensitive resin is a positive type, since the solubility in the developer 140 is increased when exposed, the exposed portion (the portion shown dark in the figure) is removed. Therefore, the first electrode pattern 25a is formed on the first main surface of the transparent base film 12 by removing a part of the first conductive film 115a, and the second electrode pattern 25b is formed by the second conductive film. By removing the exposed portion of 115b, the second main surface of the transparent base film 12 is formed.
As the developer 140 to be used, an alkaline solution, for example, an aqueous solution of sodium hydroxide, potassium hydroxide, sodium carbonate or the like can be used.

As mentioned above, although 1st Embodiment of this invention was described, this invention is not limited to 1st Embodiment. For example, each embodiment described below is possible. In addition, description is abbreviate | omitted about the structure which is common in 1st Embodiment.

[Second Embodiment]
In the first embodiment, both the first electrode pattern 25a and the second electrode pattern 25b are mesh patterns. However, the first electrode pattern 25a and the second electrode pattern 25b of the present invention include the black conductive thin wires 16 and the black conductive wires. The pattern is not limited to the mesh pattern as long as it is composed of the blank portions 17 partitioned by the fine thin lines. For example, the second electrode pattern 25b may be not a mesh pattern but a comb-like pattern in which teeth are arranged in the X direction as in the capacitance sensor 10 shown in FIG.

Other points are the same as in the first embodiment.

[Third Embodiment]
In the first embodiment, nothing is provided in the gap 20 between the adjacent first electrode patterns 25a and the gap 21 between the adjacent second electrode patterns 25b in the first conductive portion 14a and the second conductive portion 14b. However, the present invention is not limited to this. For example, as in the capacitance sensor 100 shown in FIG. 7, the first conductive portion 14a is made of the black conductive thin wire 18 made of the same material as the first electrode pattern 25a, and the gap between the adjacent first electrode patterns 25a. 20 and two or more first dummy patterns 55a electrically insulated from the first electrode pattern 25a, and the second conductive portion 14b is a black conductive thin wire 18 made of the same material as the second electrode pattern 25b. And may be provided in the gap 21 between the adjacent second electrode patterns 25b, and may have two or more second dummy patterns 55b that are electrically insulated from the second electrode patterns 25b. FIG. 8 is a cross-sectional view of one first electrode pattern 25a in the capacitance sensor 100 of FIG. 7 cut in the length direction.

The first dummy pattern 55a and the second dummy pattern 55b complement each other so that the gap 20 between the first electrode patterns 25a and the gap 21 between the second electrode patterns 25b are not conspicuous. That is, whether the blank portion 17 (the opening portion in the first embodiment) partitioned by the black conductive thin wires 16 in the first electrode pattern 25a and the second electrode pattern 25b is continuously present in the

gaps

20 and 21 as well. It looks like this.
Further, the first dummy pattern 55a is formed simultaneously with the first electrode pattern 25a when the first electrode pattern 25a is formed. Similarly, the second dummy pattern 55b is formed simultaneously with the second electrode pattern 25b when the second electrode pattern 25b is formed.

Other points are the same as in the first embodiment.

[Other changes]
Furthermore, the first electrode pattern 25a and the second electrode pattern 25b are preferably designed so that a moire pattern does not appear due to interference with the pixels of the display device. For example, in order to suppress the occurrence of moire, the arrangement direction of the first electrode pattern 25a and the arrangement direction of the second electrode pattern 25b may be inclined with respect to the pixel arrangement direction of the display device. The tilted first electrode pattern 25a and second electrode pattern 25b cause a shift in the detected position information, but a position correction circuit that corrects the position information according to the set tilt angle may be incorporated in the IC circuit. .
As another moire countermeasure, the first electrode pattern 25a and the second electrode pattern 25b may be designed so that the pitch between adjacent black conductive thin wires is not constant. Alternatively, the black conductive thin wire may be designed in a curved shape.

In addition, the first electrode pattern 25a and the second electrode pattern 25b may be configured such that the intersections of the black conductive thin wires 16 do not overlap each other. For example, as shown in FIG. 15, the intersection point of the black conductive thin wires 16 of the first electrode pattern 25a is located in the blank portion 17 of the second electrode pattern 25b (for the sake of convenience, light color representation), and the second electrode pattern The intersection of the black conductive thin wires 16 of 25b is positioned in the blank portion 17 of the first electrode pattern 25a.

In each embodiment, the first terminal wiring pattern 35a and the second terminal wiring pattern 35b are formed using the same material for the first electrode pattern 25a and the second electrode pattern 25b. However, the present invention is not limited to this. The first terminal wiring pattern 35a and the second terminal wiring pattern 35b may be formed using a material different from that of the first electrode pattern 25a and the second electrode pattern 25b. For example, since it is formed at the periphery, it is not always necessary to make it opaque. Accordingly, the conductive black agent can be omitted.

Further, in the manufacturing process of the capacitance sensor 1, after the development process, in order to improve the adhesion of the first conductive portion 14 a and the second conductive portion 14 b to the base film 12, further post-processing such as exposure and baking is performed. You may give it.

In the capacitance sensor, the first main surface of the base film 12 on which the first electrode pattern 25a is formed and the second main surface on which the second electrode pattern 25b is formed are used as touch panels on the touch panel. It is not specified whether to include it. Therefore, “first” and “second” may be interchanged in this specification.

(Flexible protective layer)
As shown in FIG. 16, the capacitance sensor 101 includes a first electrode pattern 25 a formed on the first main surface of the base film 12 and a second electrode pattern formed on the second main surface of the base film 12. 25b is preferably covered with a flexible protective film (the first protective film 180a and the second protective film 180b in FIG. 16).

By forming flexible protective films on both sides, the first electrode pattern 25a is sandwiched between the base film 12 and the first protective film 180a, and the second electrode pattern 25b is formed between the base film 12 and the second protective film 180b. It is in a state of being sandwiched between. By sandwiching the electrode pattern from both sides, the first electrode pattern 25a and the second electrode pattern 25b are entirely pressed against the base film 12 by the protective film even when the capacitance sensor 101 is bent. As a result, it is possible to suppress local stress from acting on the black conductive thin wires 16 of the first electrode pattern 25a and the second electrode pattern 25b, so that these black conductive thin wires 16 are broken or wrinkled. It becomes difficult to occur.

The protective film may cover not only the first electrode pattern 25a and the first electrode pattern 25a but also the first terminal wiring pattern 35a and the second terminal wiring pattern 35b. However, for the first terminal wiring pattern 35a and the second terminal wiring pattern 35b, one end of the side opposite to the side connected to the first electrode pattern 25a or the first electrode pattern 25a is exposed for external connection such as FPC. Let

Further, as in the third embodiment, when the capacitance sensor 1 has the first dummy pattern 55a and the second dummy pattern 55b, the protective film covers the first dummy pattern 55a and the second dummy pattern 55b. (See FIG. 17).

By forming a flexible protective film on both sides, the first electrode pattern 25a and the first dummy pattern 55a are sandwiched between the base film 12 and the first protective film 180a, and the second electrode pattern 25b and the second dummy film are formed. The pattern 55b is sandwiched between the base film 12 and the second protective film 180b. Even when the capacitance sensor 102 is bent by sandwiching the electrode pattern and the dummy pattern from both sides, not only the first electrode pattern 25a and the second electrode pattern 25b but also the first dummy pattern 55a and the second dummy pattern 55b The whole is pressed against the base film 12 by the protective film. As a result, local stress can be suppressed from acting on the black conductive thin wires 16 of the first electrode pattern 25a and the second electrode pattern 25b, and the black conductive thin wires 18 of the first dummy pattern 55a and the second dummy pattern 55b. These black conductive thin wires 16 and black conductive thin wires 18 are less likely to break or wrinkle.

The protective film is a flexible resin film. As the resin, for example, urethane resin, polyamic acid resin, acrylic rubber, or the like can be used. In the present specification, being flexible means that the protective film does not peel, crack, or bend even when it is repeatedly bent.

The protective film can be formed by screen printing using ink made of the above-described materials. Further, the protective film is a photosensitive resin made of the above-described material on both surfaces of the base film 12 in which the first conductive portion 14a is formed on the first main surface and the second conductive portion 14b is formed on the second main surface. The layer can be formed by a photo process in which both sides are exposed and developed through a photo mask. The photosensitive resin layer in the photo process may be formed by coating, or may be formed by laminating a dry film resist.

Further, when the direction in which the capacitance sensor 102 can be bent is always determined, that is, when the outer surface and the inner surface are always determined when the capacitance sensor 102 is bent, the first protective film 180a and the second protective film 180a. The material used for the protective film 180b may be different. That is, it is preferable to use a material that can easily follow the tension for the outer protective film, and a material that is less likely to cause wrinkles to the compression for the inner protection. For example, a urethane resin is used for the protective film material on the outer side and a polyamic acid resin is used for the protective film material on the inner side.

1, 10, 100, 101, 102 Capacitance sensor 12 Base film 14a First conductive portion 14b Second

conductive portion

16, 18 Black conductive thin wire 17

Blank portion

20, 21 Gap 22 Support film 23 Photosensitive conductive resin layer 24a First sensor unit 24b Second sensor unit 25a First electrode pattern 25b Second electrode pattern 34a First terminal wiring unit 34b Second terminal wiring unit 35a First terminal wiring pattern 35b Second terminal wiring pattern 40 Linear protrusion 55a First Dummy pattern 55b Second dummy pattern 60 Tourism conductive resin layer laminate 110 Double-sided laminate 111a First light 111b Second light 117a First photomask 117b Second photomask 118a First light source 118b Second light source 122a First support film 122b 2 support film 123a first photosensitive conductive resin layer 123b second photosensitive conductive resin layer 140 developer 180a first protective layer 180b second protective layer 200 columnar 201 digital signage 201a front cover 300 automobile interior moldings

Claims

A transparent base film, a first conductive portion formed on the first main surface of the base film, and a second conductive portion formed on the second main surface of the base film,
Each of the first conductive portions includes a black conductive thin wire that is opaque and has a reflectance of 2% or less, and a blank portion partitioned by the black conductive thin wire, and extends in the first direction. Having two or more first electrode patterns arranged in a second direction perpendicular to each other;
The second conductive portion is composed of a black conductive thin wire that is opaque and has a reflectance of 2% or less, and a blank portion partitioned by the black conductive thin wire, extends in the second direction, and the first direction. Two or more second electrode patterns arranged in a
The black conductive fine wire is configured to contain metal particles and a conductive black agent in a photosensitive resin.
Capacitance sensor characterized by that.
The capacitance sensor according to claim 1, wherein the metal particles are one or more metal particles selected from silver, copper, and aluminum.
The capacitance sensor according to claim 1 or 2, wherein the conductive black agent is one or more conductive black agents selected from carbon nanotubes, fullerenes, graphene, graphite, and doped amorphous carbon. .
The capacitance sensor according to any one of claims 1 to 3, wherein the photosensitive resin is a photosensitive resin containing a photopolymerization initiator.
The first electrode pattern formed on the first main surface of the base film and the second electrode pattern formed on the second main surface of the base film are respectively covered with a flexible protective film. Item 5. The capacitance sensor according to any one of Items 1 to 4.
The first conductive portion is further composed of a black conductive thin wire made of the same material as the first electrode pattern and a blank portion partitioned by the black conductive thin wire, and is disposed in a gap between the adjacent first electrode patterns. A plurality of first dummy patterns electrically insulated from the first electrode pattern,
The second conductive portion is further composed of a black conductive thin wire made of the same material as the second electrode pattern and a blank portion partitioned by the black conductive thin wire, and is disposed in a gap between the adjacent second electrode patterns. 5. The capacitance sensor according to claim 1, further comprising a plurality of second dummy patterns electrically insulated from the second electrode pattern.
The first electrode pattern and the first dummy pattern formed on the first main surface of the base film, and the second electrode pattern and the second dummy pattern formed on the second main surface of the base film are flexible. The electrostatic capacitance sensor according to claim 6, wherein each of the capacitance sensors is covered with a protective film.
A molded product with a capacitance sensor, comprising: a resin molded product having a curved surface; and the capacitance sensor according to claim 1 integrated along the curved surface of the molded product.
A photosensitive conductive resin laminate comprising a support film having peelability and a photosensitive conductive resin layer provided on the support film and containing metal particles and a conductive black agent in the photosensitive resin is used. A laminating step of laminating the photosensitive conductive resin layer surface of the photosensitive conductive resin laminate on the first main surface and the second main surface of the transparent base film,
An exposure step of performing double-sided exposure through a photomask on the double-sided laminate obtained in the above step,
The development for forming the first conductive portion and the second conductive portion according to any one of claims 1 to 4 and claim 6 by developing the photosensitive conductive resin layer after exposure and after peeling of the support film. Process,
A method for manufacturing a capacitance sensor, comprising: