JP6476578B2 - Touch panel - Google Patents

Description

  The present invention relates to a touch panel provided with a transparent conductive film formed on a transparent substrate.

  In recent years, a transparent touch panel has been used as an input device on displays of various electronic devices. Examples of the touch panel method include a resistive film type and a capacitance type. In the resistance film type, the touch position is detected by the contact of the upper and lower electrodes. Further, in the electrostatic capacitance type, the touch position is detected by the change in the electrostatic capacitance of the surface when the finger touches or the like.

  The drive electrode and the sense electrode constituting the sensor unit of the capacitive touch panel are formed of a transparent conductive film (transparent electrode), and are usually connected to a metal wiring (wiring unit). Patent Document 1 describes a touch panel of this type. In the touch panel described in Patent Document 1, dummy lead-out lines are provided at both ends of the lead-out line, and the dummy lead-out lines are connected so as to have a predetermined potential of the non-selected detection lines.

JP, 2010-257178, A

  In this type of touch panel, it is general to cover the wiring portion from above or below, or to provide a ground electrode outside the wiring portion, in order to shield the wiring portion and the sensor portion from being affected by external noise. When the ground electrode is disposed in the same layer as the drive electrode, the ground electrode is formed to overlap with the wiring of the sense electrode or to be located at the outer peripheral portion. In addition, when the ground electrode is disposed in the same layer as the sense electrode, the ground electrode is formed to overlap with the wiring of the drive electrode or to be located at the outer peripheral portion.

In such a case, since an electric field in a certain direction is generated between the ground electrode and the drive electrode or sense electrode, the transparent conductive film may be broken due to ion migration depending on the material of the transparent conductive film used for the drive electrode or sense electrode. Or there is a problem of shorting between the transparent conductive film and the ground electrode. Ion migration may occur particularly under high temperature and high humidity.
Then, this invention is made in view of such a subject, and it aims at providing the touch panel which can control generating an electric field of a fixed direction between a drive electrode or a sense electrode, and a grand electrode. .

According to a first aspect of the present invention, there is provided a plurality of transparent conductive films each including a transparent substrate, a patterned transparent conductive film, and a metal wiring connected to the transparent conductive film, the plurality of patterned conductive conductive films extending in a predetermined direction. and drive electrodes, formed of a transparent conductive film is patterned, a touch panel and a plurality of sense electrodes are disposed in different layers extending in a direction intersecting with the drive electrode, the one of the drive electrodes or sense electrodes A ground electrode disposed in the same layer as the electrodes, and a ground electrode formed to extend in the same direction as one of the electrodes outside the sensor area where the one electrode is arranged, and a drive electrode disposed in the same layer as the ground electrode or out of the sense electrodes, and the electrode closest to the ground electrode, between the ground electrode, most ground electrode and the ground electrode It is a touch panel which is characterized in that comprises a gastric electrode and the electrode closest to the ground electrode formed of a conductive material so as to extend in the same direction and always an auxiliary electrode located in equipotential.

  The second invention is characterized in that the auxiliary electrode is located outside the outermost part of the transparent conductive film forming the drive electrode or sense electrode provided in a layer different from the auxiliary electrode. It is.

  According to a third aspect of the invention, a drive electrode is formed in an area where a sensor area in which the auxiliary electrode is disposed in the same layer as the auxiliary electrode and a sensor area in which a drive electrode or sense electrode arranged in a layer different from the auxiliary electrode is arranged The touch panel according to the first or second aspect of the invention is characterized in that the touch panel is located outside the touch sensor effective area which is an area obtained by adding half of the arrangement pitch of the sense electrodes.

  According to a fourth aspect of the invention, the auxiliary electrode is connected to the drive electrode or sense electrode provided in a layer different from the auxiliary electrode outside the drive electrode provided in the layer different from the auxiliary electrode or the sensor area where the sense electrode is arranged. It is a touch panel according to any one of the first to third inventions characterized in that it intersects with the metal wiring.

  The fifth invention is any of the first to fourth, wherein a width of a drive electrode, a sense electrode, or a metal wiring provided at a position overlapping the auxiliary electrode and a layer different from the auxiliary electrode is smaller than 500 μm. It is a touch panel of one invention.

  A sixth invention is the touch panel according to any one of the first to fifth inventions, wherein the width of the auxiliary electrode is smaller than 1 mm.

  A seventh invention is the touch panel according to any one of the first to sixth inventions, wherein the auxiliary electrode includes at least metal nanowires.

  An eighth invention is the touch panel according to the seventh invention, characterized in that the metal nanowires are covered with a resin layer.

  A ninth invention is the touch panel according to any one of the first to eighth inventions, wherein the auxiliary electrode includes a metal electrode.

  A tenth invention is the touch panel according to any one of the first to ninth inventions, wherein the drive electrode and / or the sense electrode is covered with a metal material at an end not connected to the metal wiring. It is.

  According to the present invention, among the transparent conductive films constituting the sensor of the touch panel, the drive electrode and / or sense electrode located at the outermost between the drive electrode (transparent electrode) and / or the sense electrode (transparent electrode) and the ground electrode The auxiliary electrode which is always at the same potential is formed, and the problem of the touch sensor operation due to the ion migration of the transparent electrode is eliminated.

  According to the present invention, ion migration between the transparent electrode and the ground electrode is suppressed by adopting an electrode structure of the touch sensor that prevents generation of an electric field in a certain direction between the transparent electrode and the ground electrode, A highly reliable touch panel can be provided.

Cross-sectional view of the configuration of the touch panel according to an embodiment of the present invention and Example 1 The top view of the structure of the touch panel of embodiment concerning this invention, and Example 1 Cross-sectional view of the configuration of the touch panel according to an embodiment of the present invention and Example 2 Top view of the configuration of the touch panel according to the embodiment of the present invention and Example 2 Cross-sectional view of the configuration of the touch panel of Comparative Example 1 Top view of the configuration of the touch panel of Comparative Example 1

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention can not be limited to the embodiments described below, and it is also possible to add a design change or the like based on the knowledge of those skilled in the art, and an embodiment in which such a change is added. Forms are also included within the scope of the present invention.

  FIG.1 and FIG.3 is an example of the cross section of the touch panel of this invention. FIG. 1 shows a cross section of the position of line A of FIG. 2 showing a plan view of the touch panel of the present invention. FIG. 3 shows a cross section at the position of line B in FIG. 4 showing a plan view of the touch panel of the present invention. 1 to 4 are drawings showing a part of the touch panel.

The touch panel 100, 200 includes a transparent substrate 1, a plurality of drive electrodes 3 formed of a patterned transparent conductive film, a plurality of sense electrodes 4 formed of a patterned transparent conductive film, and a transparent conductive film And a transparent adhesive layer 10 and a sensor cover 11 at least. The drive electrode 3 and the sense electrode 4 are disposed in different layers and intersect with each other with the transparent substrate 1 interposed therebetween. Each drive electrode 3 is formed in a linear shape, and is connected to each metal wire 8 provided in the same layer. Each sense electrode 4 is linearly formed, and connected to each metal wire 9 provided in the same layer.
In the touch panel 100 shown in FIG. 1, the drive electrode 3 and the sense electrode 4 are formed on the same side (upper side in FIG. 1) of different transparent substrates 1. In the touch panel 200 shown in FIG. 3, the drive electrode 3 and the sense electrode 4 are formed on different sides of the same transparent substrate 1.
In the touch panels 100 and 200, the area in which all the drive electrodes 3 are arranged is the first sensor area, and the area in which all the sense electrodes 4 are arranged is the second sensor area. In addition, an area obtained by adding half of the arrangement pitch of the drive electrodes or the sense electrodes to the area where the first sensor area and the second sensor area overlap when viewed from the thickness direction of the touch panel 100, 200 is the touch sensor effective area. Become.

The touch panel 100, 200 further includes a ground electrode 6 and an auxiliary electrode 5.
The ground electrode 6 has a ground potential. The ground electrode 6 is disposed in the same layer as one of the drive electrode 3 and the sense electrode 4 and is formed outside the sensor area in which one of the electrodes is arranged. As shown in FIGS. 2 and 4, the ground electrode 6 is disposed on one side of the transparent substrate 1 along the outer periphery thereof.
The auxiliary electrode 5 is formed in a linear shape. Auxiliary electrode 5 is disposed between ground electrode 6 and an electrode closest to ground electrode 6 (a transparent conductive film located at the outermost position) of drive electrode 3 or sense electrode 4 arranged in the same layer as ground electrode 6. It is formed. The auxiliary electrode 5 is made of a conductive material and is always at the same potential as the electrode 3 or 4 closest to the ground electrode 6 described above. In the touch panels 100 and 200, the auxiliary electrode 5 is provided outside the sense electrode 4 and connected so as to be equipotential when the outermost sense electrode 4 is selected and not selected.

  The auxiliary electrode 5 may be located outside the outermost portion of the transparent conductive film constituting the drive electrode 3 or the sense electrode 4 provided in a layer different from the auxiliary electrode 5. In addition, the auxiliary electrode 5 is located outside the touch sensor effective area. Auxiliary electrode 5 is provided on drive electrode 3 or sense electrode 4 provided in a layer different from auxiliary electrode 5 outside the sensor area where drive electrode 3 or sense electrode 4 provided in a layer different from auxiliary electrode 5 is arranged. Crosses the connected metal wires 8 or 9. Width of drive electrode 3, sense electrode 4, or metal wiring 8, 9 provided at a position overlapping with auxiliary electrode 5 in a layer different from auxiliary electrode 5 (width of transparent conductive film formed outside touch sensor effective area) May be smaller than 500 μm. The width of the auxiliary electrode 5 may be smaller than 1 mm. In addition, the auxiliary electrode 5 may include at least metal nanowires, and the metal nanowires may be covered with a resin layer. In addition, the auxiliary electrode 5 may include a metal electrode. Further, the end of the drive electrode 3 and / or the sense electrode 4 not connected to the metal wiring may be covered with a metal material.

  Glass, a plastic plate, or a plastic film is used for the transparent substrate 1 used by this invention. The material of the transparent substrate 1 is not particularly limited as long as it has sufficient strength in the film forming step and the subsequent step and the surface smoothness is good, but for example, soda lime glass, PMMA, polyethylene terephthalate film, polybutylene terephthalate A film, a polyethylene naphthalate film, a polycarbonate film, a polyethersulfone film, a polysulfone film, a polyarylate film, a cyclic polyolefin film, a polyimide film or the like can be used. The thickness of the transparent substrate 1 is about 50 μm or more and 1 mm or less for glass, and about 10 μm or more and 200 μm or less for a plastic film in consideration of thinning of members and flexibility of a laminate. When the touch panel of the present invention is disposed on the front of a display, the transparent substrate 1 is required to have high transparency, and one having a total light transmittance of 85% or more is suitably used.

  As materials contained in the transparent substrate 1, various well-known additives and stabilizers such as an antistatic agent, a plasticizer, a lubricant, an adhesive and the like may be used. In order to improve the adhesion to each layer, corona treatment, low temperature plasma treatment, ion bombardment treatment, chemical treatment or the like may be applied as pretreatment of the surface of the transparent substrate 1.

  The resin layer 2 may be formed on one side or both sides of the transparent substrate 1 of the present invention. The resin layer 2 used in the present invention is formed particularly when a plastic material is used for the transparent substrate 1, and is provided in order to provide the transparent substrate 1 and the transparent conductive film 3 with mechanical strength. The resin used for the resin layer 2 is not particularly limited, but a resin having transparency, appropriate hardness and mechanical strength is preferable. Specifically, a photocurable resin such as a monomer or a crosslinkable oligomer containing a trifunctional or higher functional acrylate capable of three-dimensional crosslinking as a main component is preferable.

  As trifunctional or higher acrylate monomers, trimethylolpropane triacrylate, isocyanuric acid EO modified triacrylate, pentaerythritol triacrylate, dipentaerythritol triacrylate, dipentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate It is preferable to use ditrimethylolpropane tetraacrylate, pentaerythritol tetraacrylate, polyester acrylate and the like. Particularly preferred are isocyanuric acid EO modified triacrylates and polyester acrylates. These may be used alone or in combination of two or more. In addition to these trifunctional or higher functional acrylates, so-called acrylic resins such as epoxy acrylate, urethane acrylate and polyol acrylate can be used in combination.

  As the crosslinkable oligomer, it is preferable to use an acrylic oligomer such as polyester (meth) acrylate, polyether (meth) acrylate, polyurethane (meth) acrylate, epoxy (meth) acrylate and silicone (meth) acrylate. Specifically, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, bisphenol A epoxy acrylate, polyurethane diacrylate, cresol novolac epoxy (meth) acrylate, etc. can be used.

  The resin layer 2 may further contain additives such as particles and a photopolymerization initiator.

  As particles to be added to the resin layer 2, organic or inorganic particles can be used, but in consideration of transparency, it is preferable to use organic particles. As the organic particles, particles made of acrylic resin, polystyrene resin, polyester resin, polyolefin resin, polyamide resin, polycarbonate resin, polyurethane resin, silicone resin, fluorine resin and the like can be used.

  The average particle size of the particles varies depending on the thickness of the resin layer 2, but due to the appearance such as haze, the lower limit is 2 μm or more, more preferably 5 μm or more, and the upper limit 30 μm or less, preferably 15 μm or less Do. In addition, the content of the particles is also preferably 0.5% by weight or more and 5% by weight or less based on the resin for the same reason.

  When a photopolymerization initiator is added, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin such as benzyl methyl ketal and its alkyl ethers, acetophenone, and the like as a radical generating photopolymerization initiator Acetophenones such as -dimethoxy-2-phenylacetophenone and 1-hydroxycyclohexyl phenyl ketone, anthraquinones such as methyl anthraquinone, 2-ethyl anthraquinone and 2-amyl anthraquinone, thioxanthone, 2,4-diethyl thioxanthone, 2, 4 -Thioxanthones such as diisopropyl thioxanthone, Ketals such as acetophenone dimethyl ketal, benzyl dimethyl ketal, benzophenone, 4, 4-bisme Le benzophenones such aminobenzophenone and azo compounds, and the like. These can be used alone or as a mixture of two or more, and further, triethanolamine, tertiary amines such as methyldiethanolamine, 2-dimethylaminoethylbenzoic acid, benzoic acid derivatives such as ethyl 4-dimethylaminobenzoate, etc. It can be used in combination with a photo-starting aid etc.

  The addition amount of the photopolymerization initiator is 0.1% by weight or more and 5% by weight or less, preferably 0.5% by weight or more and 3% by weight or less based on the resin of the main component. If it is less than the lower limit value, curing of the resin layer 2 (hard coat layer) becomes insufficient, which is not preferable. Moreover, when exceeding an upper limit, since it causes yellowing in the resin layer 2 (hard coat layer), or a weather resistance falls, it is unpreferable. The light used to cure the photocurable resin is ultraviolet light, electron beam, gamma ray or the like, and in the case of electron beam or gamma ray, it is not always necessary to contain a photopolymerization initiator or a photoinitiation aid. As these radiation sources, high pressure mercury lamps, xenon lamps, metal halide lamps, accelerated electrons and the like can be used.

  The thickness of the resin layer 2 is not particularly limited, but is preferably in the range of 0.5 μm to 15 μm. Further, the refractive index of the resin layer 2 is more preferably the same as or similar to the refractive index of the transparent substrate 1, and about 1.45 to 1.75.

  In the method for forming the resin layer 2, in order to apply a coating liquid in which a resin as a main component is dissolved in a solvent, a die coater, a curtain flow coater, a roll coater, a reverse roll coater, a gravure coater, a knife coater, a bar A known coating method using a coating machine such as a coater, a spin coater or a microgravure coater can be used.

  The solvent is not particularly limited as long as it dissolves the above-mentioned main component resin and the like. Specifically, as a solvent, ethanol, isopropyl alcohol, isobutyl alcohol, benzene, toluene, xylene, acetone, methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, n-butyl acetate, isoamyl acetate, ethyl lactate, methyl cellosolve, ethyl cellosolve, Butyl cellosolve, methyl cellosolve acetate, propylene glycol monomethyl ether acetate, etc. may be mentioned. One of these solvents may be used alone, or two or more thereof may be mixed.

  A transparent conductive film can be used for each of the drive electrode 3, the sense electrode 4, the auxiliary electrode 5, and the ground electrode 6 of the present invention. For the transparent conductive film, use is made of indium oxide, zinc oxide or tin oxide as an oxide, or a mixed oxide of two or three of them, as well as those to which other additives are added, etc. However, various materials can be used depending on the purpose and application, and are not particularly limited. At present, the most reliable and most proven material is indium tin oxide (ITO).

  When indium tin oxide (ITO), which is the most common transparent conductive film, is used as the material of the transparent conductive film, the content ratio of tin oxide doped in indium oxide is an arbitrary ratio according to the specifications required for the device. Choose For example, in the case where the transparent substrate 1 (transparent resin substrate) is a plastic film, the sputtering target material used to crystallize a thin film for the purpose of enhancing mechanical strength has a tin oxide content ratio of less than 10% by weight The content ratio of tin oxide is preferably 10% by weight or more in order to make the thin film amorphous and to have flexibility. When low resistance is required for the thin film, the content ratio of tin oxide is preferably in the range of 2% by weight to 20% by weight.

  When the transparent conductive film is an oxide, any film forming method may be used as long as the film thickness can be controlled, and among them, the dry method is excellent. For this, a physical vapor deposition method such as vacuum deposition or sputtering, or a chemical vapor deposition method such as CVD can be used. In particular, in order to form a thin film of uniform film quality over a large area, a sputtering method in which the process is stable and the thin film is densified is preferable.

  Moreover, when the transparent conductive film is patterned by a method such as etching, the optical adjustment layer can be formed so that the pattern is difficult to visually recognize. The optical adjustment layer is formed of a thin film in a single layer or multiple layers using an inorganic oxide or an organic compound having a predetermined refractive index as a material. The optical adjustment layer can impart pattern invisibility by adjusting the transmittance, reflectance, color and the like of the region where the transparent conductive film is present and the region where the transparent conductive film is absent.

  Further, an adhesion layer of metal, metal oxide, resin, silane coupling agent or the like can be provided under the transparent conductive film or the optical adjustment layer.

  For the transparent conductive film, materials such as metal nanoparticles, metal nanowires, carbon nanotubes, graphene, and conductive polymers can be used. The transparent conductive film can be formed by applying and drying a coating liquid in which such a material is dissolved or dispersed in an organic solvent, alcohol, water or the like. In view of sheet resistance and transparency as a transparent conductive film, metal nanowires are more preferably used.

  The coating solution is prepared by mixing the metal nanowires with a resin or the like and dispersing the mixture in water, an alcohol, an organic solvent or the like. The coating solution is applied and then dried to form a transparent conductive film in which the metal nanowires are intertwined with each other to form a mesh, and a good electric conduction path is obtained even with a small amount of conductive material. It can form and the resistance value of a transparent conductive film (conductive layer) can be reduced more. Furthermore, when such a net-like transparent conductive film is formed, the opening of the interstices of the net is large, so even if the fibrous conductive substance itself is not transparent, the transparent conductive film ( It is possible to achieve good transparency as a coating).

  Specifically, iron, cobalt, nickel, copper, zinc, aluminum, titanium, ruthenium, rhodium, palladium, silver, cadmium, osmium, iridium, platinum, gold can be used as the metal of the metal nanowire, and it is conductive. Gold, silver, copper and platinum are preferred from the viewpoint of

  As a method of forming a transparent conductive film on the transparent substrate 1 using the metal nanowires and the like, it is possible to use known coating methods such as spray coating, bar coating, roll coating, die coating, ink jet coating, screen coating, dip coating Can.

  When the film thickness is too thin, the transparent conductive film tends to be unable to achieve sufficient conductivity as a conductor, and when the film thickness is too thick, the transparency is impaired due to an increase in haze value and a decrease in total light transmittance. There is a tendency. The film thickness of the transparent conductive film is appropriately adjusted between 10 nm and 10 μm, but when the conductive substance itself is not transparent like metal nanowires, the transparency tends to be lost due to the increase in film thickness, A thinner transparent conductive film may be formed. In this case, the transparent conductive film has an extremely large number of openings, but when measured with a contact-type film thickness meter, a film thickness range of 10 nm to 500 nm is preferable as an average film thickness, 30 nm to 300 nm is more preferable, and 50 nm to 150 nm. Is most preferred.

  A cured film can be provided to protect the transparent conductive film and to provide mechanical strength. In particular, when metal nanoparticles, metal nanowires, carbon nanotubes, graphene, conductive polymers, etc. are used as the transparent conductive film, it is preferable to form a cured film in order to obtain environmental test resistance. The resin used for the cured film is not particularly limited, but a resin having transparency, appropriate hardness and mechanical strength is preferable. Specifically, a photocurable resin such as a monomer or a crosslinkable oligomer mainly composed of a trifunctional or higher functional acrylate capable of three-dimensional crosslinking is preferable, and it is possible to form it using the same material as the resin layer 2 it can. As a method of forming a cured film, the same method as the resin layer 2 can be used.

  When the drive electrode 3 is formed on one side of one transparent substrate 1 as shown in FIG. 3 and the sense electrode 4 is formed on the other side, the protective layer 13 on the opposite side of the transparent substrate 1 to the sensor cover 11 side. May be provided. Protective layer 13 has mechanical strength to protect drive electrode 3 or sense electrode 4 and metal interconnection 8 connected to drive electrode 3 or metal interconnection 9 connected to sense electrode 4 or is environmentally resistant. Form for the purpose of obtaining The resin used for the protective layer 13 is not particularly limited, but a resin having transparency is preferable. Specifically, a photocurable resin such as a monomer or a crosslinkable oligomer mainly composed of a trifunctional or higher functional acrylate capable of three-dimensional crosslinking is preferable, and it is possible to form it using the same material as the resin layer 2 it can. The method of forming the protective layer 13 can also be the same as that of the resin layer 2.

  The transparent conductive film constituting the drive electrode 3 and the sense electrode 4 is used as a rectangular or diamond pattern when used as a touch panel sensor. The conductive pattern area is connected to the metal wire 8 or 9, and is connected via the metal wire 8 or 9 to a voltage change detection circuit capable of detecting a voltage change. When a human finger or the like approaches the sense electrode 4 which is a detection electrode through the sensor cover 11, the entire electrostatic capacitance changes, so the voltage of the circuit fluctuates, and the contact position can be determined. . The pattern of the transparent conductive film is composed of a series of drive electrode 3 rows and a sense electrode 4 row. Two-dimensional position information can be obtained by electrically connecting each row of drive electrodes 3 and each row of sense electrodes 4 with the voltage change detection circuit.

  As a method of forming a pattern of the transparent conductive film constituting the drive electrode 3 and the sense electrode 4, a resist is applied or bonded on the transparent conductive film, and the pattern is formed by exposure and development to dissolve the transparent conductive film chemically. A method by photolithography, a method of vaporizing by a chemical reaction in vacuum, a method of sublimating a transparent conductive film by a laser, or the like can be used. The pattern formation method can be appropriately selected depending on the shape of the pattern, accuracy, etc., but in consideration of pattern accuracy and thinning, a method by photolithography is preferable. Between the electrode and the electrode, a dummy electrode having no function as a sense electrode may be formed.

  A metal can be used for each of the drive electrode wiring 8, the sense electrode wiring 9, the auxiliary electrode 5, and the ground electrode 6 of the present invention. As the metal, iron, cobalt, nickel, copper, zinc, molybdenum, aluminum, titanium, ruthenium, rhodium, palladium, silver, osmium, iridium, platinum, gold can be used, but from the viewpoint of conductivity, copper, silver Molybdenum, aluminum, titanium or laminates thereof are suitably used.

The same method as the transparent conductive film of oxide can be used for the method of forming the metal electrodes 5 and 6 or the wirings 8 and 9 and the patterning method. As a dry method, physical vapor deposition such as vacuum deposition or sputtering, or chemical vapor deposition such as CVD can be used, and metal nanoparticles can be formed by coating and firing. You can also. For patterning, methods such as etching and lift-off, screen printing in which metal paste or metal ink is directly printed, inkjet, gravure offset printing, letterpress printing, gravure printing, imprinting, or the like can be used.
In any method, conditions suitable for process suitability such as heat resistance and chemical resistance of the transparent substrate 1 are appropriately selected.

  According to the present invention, the auxiliary electrode 5 made of a conductive material is provided between the transparent conductive film forming the drive electrode 3 or the sense electrode 4 and the ground electrode 6 formed in the same layer as the transparent conductive film. It is characterized by Since the auxiliary electrode 5 is located outside the drive electrode 3 or the sense electrode 4, the auxiliary electrode 5 is placed outside the touch sensor effective area. That is, in the normal use method, the auxiliary electrode 5 is disposed under the frame of the sensor cover 11. The auxiliary electrode 5 is made of a transparent conductive material or a metal material, and is electrically short-circuited with the outermost electrode of the sensor panel among the drive electrode 3 or sense electrode 4 in the same layer, and the outermost drive It is always equipotential with the electrode or sense electrode. As the wiring design, as shown in FIG. 2 and FIG. 4, the method of connecting the metal wiring 9 and the auxiliary electrode 5 is most suitably used, but the method is not limited to this. And the auxiliary electrode 5 may be connected to the LSI chip, and a signal may be transmitted from the LSI chip so as to be equipotential.

In FIGS. 1 and 3, the ground electrode 6 and the auxiliary electrode 5 are formed in the same layer as the sense electrode 4. The auxiliary electrode 5 is disposed between the sense electrode 4 closest to the ground electrode 6 among the plurality of sense electrodes 4 and the ground electrode 6 along the same direction as the electrodes 4 and 6. And are spaced apart.
When ground electrode 6 and auxiliary electrode 5 are formed in the same layer as drive electrode 3, auxiliary electrode 5 is located between drive electrode 3 closest to ground electrode 6 among ground electrodes 6 and ground electrode 6. The electrodes 3 and 6 are spaced apart from each other along the same direction as the electrodes 3 and 6.

  According to the present invention, the auxiliary electrode 5 is always at the same potential with the drive electrode 3 or sense electrode 4 located at the outermost part of the sensor panel, whereby a certain direction between the ground electrode 6 and the drive electrode 3 or sense electrode 4 is obtained. It can suppress that an electric field arises. As a result, the occurrence of ion migration that has occurred from the drive electrode 3 or the sense electrode 4 toward the ground electrode 6 can be suppressed, and the touch panels 100 and 200 can be provided with better environmental resistance. In particular, the effect is large when using a transparent conductive film made of silver or copper which easily causes ion migration.

  The auxiliary electrode 5 may be disposed overlapping with the metal wiring 8 or 9 located in a layer different from the auxiliary electrode 5 as shown in FIGS. 1 and 3 or a drive located in a layer different from the auxiliary electrode 5 It may be disposed overlapping with the electrode 3 or the sense electrode 4. However, since the auxiliary electrode 5 forms a capacitance with the electrodes 3 and 4 or the wirings 8 and 9 located in different layers, it is necessary to reduce the overlapping area as much as possible in order to minimize the influence. Therefore, the width of the auxiliary electrode 5 is preferably smaller than 1 mm, and the widths of the metal wires 8 and 9, the drive electrode 3, and the sense electrode 4 which are disposed overlapping with the auxiliary electrode 5 and located in different layers from the auxiliary electrode 5 are And preferably less than 500 μm.

  The touch panel of the present invention may form an end covering electrode 12 in which the end not connected to the metal wires 8 and 9 among the ends of the drive electrode 3 and the sense electrode 4 is coated with metal. In FIG. 4, the end of the sense electrode 4 not connected to the metal wire 9 is covered with the end covering electrode 12. For the end covering electrode 12, a metal material such as copper, silver, molybdenum, aluminum, titanium or a laminate thereof can be used, and a transparent conductive material such as ITO can also be used.

  The drive electrode 3 and the sense electrode 4 of the touch panel of the present invention function as a capacitance detection sensor. As shown in FIG. 3, the drive electrode 3 and the sense electrode 4 may be disposed on both sides of one transparent substrate 1 or may be provided on separate transparent substrates 1 as shown in FIG. You may bond together through the adhesive layer 10, and may arrange | position up and down. The drive electrode 3 and the sense electrode 4 formed of a transparent conductive film are connected to the metal wires 8 and 9, respectively, and are connected to a circuit for detecting a capacitance change between the upper electrode and the lower electrode by the transparent conductive film. Operates as a capacitive touch sensor. By finally bonding the touch sensor to the sensor cover 11 via the transparent adhesive layer 10, a touch panel can be manufactured. The sensor cover 11 may be made of glass or a sheet of resin or plastic material whose surface is hard-coated. When glass is used, it is preferable to use a tempered glass which is chemically strengthened by ion exchange of sodium ions in soda glass.

  EXAMPLES Hereinafter, the present invention will be described in detail by way of specific examples, but these examples are for the purpose of illustration and the present invention is not limited thereto.

Example 1
A touch panel 100 having the same layer configuration as that of FIG. 1 was produced. FIG. 2 is a plan view showing an electrode portion of the touch panel 100, and a schematic view of a cross section taken along a line A is FIG. After forming a UV curable transparent acrylic resin by microgravure coating on one side of each transparent substrate 1 using PET (125 μm) as each transparent substrate 1, the resin layer 2 is formed to a thickness of 3 μm by drying and UV curing did. On the surface of each transparent substrate 1 opposite to the resin layer 2, a UV curable acrylic resin containing zirconia particles was formed with a thickness of 90 nm as an optical adjustment layer. At this time, the refractive index of the optical adjustment layer was 1.70. A thin film is formed with a thickness of 22 nm by DC magnetron sputtering of ITO (tin content 5 wt%) as a material of a transparent conductive film on the obtained optical adjustment layer in vacuum at 150 ° C., 60 ° C. By annealing in minutes, a transparent conductive film having a sheet resistance of 150 Ω / □ was obtained. After exposing and developing each of the obtained substrates with a transparent conductive film with a dry film photoresist by photolithography, the transparent conductive film was patterned by etching and resist peeling. Two types of transparent conductive film patterns were prepared, one having a rectangular electrode corresponding to the drive electrode 3 and the other having a rectangular electrode corresponding to the sense electrode 4. The inter-electrode pitch of the drive electrode 3 and the sense electrode 4 was 5 mm. In the same layer as the sense electrode 4, the auxiliary electrode 5 formed of a transparent conductive film and the ground electrode 6 were simultaneously formed. The width of the auxiliary electrode 5 was 500 μm.

  During photolithography, development of the photoresist was carried out with an aqueous solution of sodium carbonate, the ITO was etched with an aqueous solution of salted nitric acid, and the resist was peeled off with an aqueous solution of sodium hydroxide.

  A silver paste pattern is formed by screen printing as drive electrode wiring 8 and sense electrode wiring 9 on the transparent conductive films of drive electrode 3 and sense electrode 4 obtained above, and heated at 90 ° C. for 30 minutes. Therefore, it was made a pattern with wiring. The sense electrode wiring 9 connected to the outermost electrode of the sense electrode 4 was also connected to the auxiliary electrode 5 as shown in FIG. The outermost electrode of the sense electrode 4 was electrically connected to the auxiliary electrode 5. These drive electrode-attached PET substrates and sense electrode-attached PET substrates are pasted together using the 75 μm-thick transparent adhesive layer 10 as shown in FIG. 1, and the outermost surface is chemically strengthened by 0.55 mm. Similarly, the touch panel 100 was obtained by bonding the cover glass 11 using the transparent adhesive layer 10.

  The operation check of the touch panel 100 was performed by connecting the silver wires 8 and 9 to the drive LSI via the flexible printed circuit. As a result, it was possible to detect finger contact and coordinate position well. The obtained touch panel 100 is operated in an environment of 60 ° C. and 90% Rh for 1,500 hours, and then taken out from the environmental testing machine, and the operation check is performed similarly to the above. Was detected.

Example 2
A touch panel 200 having the same layer configuration as that of FIG. 3 was produced. FIG. 4 is a plan view showing the electrode part of the touch panel 200, and FIG. 3 is a schematic view of a cross section taken along the line B. As shown in FIG. After microgravure coating of a UV curable transparent acrylic resin using PET (125 μm) as the transparent substrate 1 and adding 20 wt% of a UV absorber on both sides, the resin layer 2 is made 5 μm thick by drying and UV curing Each formed. A transparent conductive film is formed by coating a silver nanowire as a material of the transparent conductive film on both sides of the obtained substrate by slot die coating so as to have a sheet resistance of 100 Ω / □, and similarly a UV curable transparent acrylic resin To a thickness of 130 nm to form a cured film.

The obtained double-sided transparent conductive film-attached substrate is exposed and developed with a dry film photoresist by photolithography in the same manner as in Example 1, and then the etching and the resist are peeled off to form the drive electrode 3 of the transparent conductive film on one side. The transparent conductive film on the other side was patterned as the sense electrode 4. During photolithography, development of the photoresist was carried out with an aqueous solution of sodium carbonate, the silver nanowires were etched with a ferric chloride solution, and the resist was peeled off with an aqueous solution of sodium hydroxide. In addition, silver wires 8 and 9 were also formed on both sides in the same manner as in Example 1. At this time, the auxiliary electrode 5 was formed of silver paste in the same layer as the sense electrode 4 as in FIG. The width of the auxiliary electrode 5 is 100 μm. Further, the ground electrode 6 was also formed in the same layer as the sense electrode 4. Further, the end covering electrode 12 was formed in the same manner as in FIG. 4 so as to cover the end of the sense electrode 4.
The touch panel 200 was obtained by bonding the chemically strengthened cover glass 11 having a thickness of 0.55 mm to the outermost surface using the transparent adhesive layer 10 having a thickness of 75 μm and the base material with a double-sided transparent conductive film obtained above.

  The operation check of the touch panel was performed by connecting the silver wires 8 and 9 to the driving LSI via the flexible printed circuit. As a result, it was possible to detect finger contact and coordinate position well. The obtained touch panel is operated in an environment of 60 ° C. and 90% Rh for 240 hours, and then taken out of the environmental testing machine, and the operation check is performed similarly to the above. It could be detected.

Comparative Example 1
A touch panel 300 having the same layer configuration as that of FIG. 5 was produced. FIG. 6 is a plan view showing the electrode part of the touch panel 300, and FIG. 5 is a schematic view of a cross section taken along the line C. As shown in FIG.
A touch panel 300 was produced in the same manner as in Example 2 except that the auxiliary electrode 5 was not provided in the same layer as the sense electrode 4.

  The touch panel 300 immediately after the preparation worked well, and was able to detect a finger touch and a coordinate position. However, after operating the obtained touch panel 300 in an environment of 60 ° C. and 90% Rh for 240 hours, it is taken out from the environmental testing machine and the operation check is performed in the same manner as described above. It was down. The silver nanowires of the transparent conductive film constituting the sense electrode 4 between the sense electrode 4 and the ground electrode 6 had undergone ion migration.

  As mentioned above, although the example of this invention and the comparative example were represented representatively with the touch panel in which the shape of the drive electrode 3 and the sense electrode 4 is a rectangle, it is not this limitation about an electrode shape, It is diamond type or other shapes. It does not matter.

  The touch panel of the present invention is used as a capacitive touch panel, and can be used as a user interface or the like disposed on the front surface of a smartphone, a tablet, a notebook PC or the like.

1 ... transparent substrate 2 ... resin layer 3 ... drive electrode (transparent conductive film)
4 ... sense electrode (transparent conductive film)
5 ... auxiliary electrode 6 ... ground electrode (same layer as sense electrode)
8 ... drive electrode wiring 9 ... sense electrode wiring 10 ... transparent adhesive layer 11 ... sensor cover 12 ... end covering electrode 13 ... protective layer 100 ... touch panel 200 ... touch panel 300 ... touch panel of comparative example

Claims (10)

A plurality of drive electrodes including at least a transparent substrate, a patterned transparent conductive film, and a metal wiring connected to the transparent conductive film, wherein the plurality of drive electrodes are formed of the patterned transparent conductive film and extend in a predetermined direction ; wherein it is constituted by patterned transparent conductive film, a plurality of sense electrodes extending in a direction intersecting with the drive electrode is a touch panel disposed on different layers,
A ground electrode disposed in the same layer as one of the drive electrode or the sense electrode and extending in the same direction as the one electrode outside the sensor area in which the one electrode is arranged. When,
Of the drive electrode or sense electrode disposed in the same layer as the ground electrode, the electrode closest to the ground electrode and the ground electrode in the same direction as the ground electrode and the electrode closest to the ground electrode is composed of a conductive material so as to extend, a touch panel, characterized in that an auxiliary electrode is always equal potential closest electrode to the ground electrode.   The touch panel according to claim 1, wherein the auxiliary electrode is positioned outside the outermost portion of a transparent conductive film forming a drive electrode or a sense electrode provided in a layer different from the auxiliary electrode.   The drive electrode or the sense electrode is located in an area where the auxiliary electrode overlaps the sensor area in the same layer as the auxiliary electrode and the sensor area in which the drive electrode or sense electrode arranged in a layer different from the auxiliary electrode is arranged. The touch panel according to claim 1, wherein the touch panel is located outside the touch sensor effective area which is an area obtained by adding half of the arrangement pitch of the electrodes.   A metal connected to a drive electrode or sense electrode provided in a layer different from the auxiliary electrode, outside the sensor area where the auxiliary electrode is provided in a layer different from the auxiliary electrode or the drive electrode or sense electrode is arranged The touch panel according to any one of claims 1 to 3, characterized in that it intersects with a wiring.   The width of a drive electrode, a sense electrode, or a metal wiring provided at a position overlapping with the auxiliary electrode in a layer different from the auxiliary electrode is smaller than 500 μm. Touch panel described.   The touch panel according to any one of claims 1 to 5, wherein the width of the auxiliary electrode is smaller than 1 mm.   The touch panel according to any one of claims 1 to 6, wherein the auxiliary electrode includes at least metal nanowires.   The touch panel according to claim 7, wherein the metal nanowires are covered with a resin layer.   The touch panel according to any one of claims 1 to 8, wherein the auxiliary electrode comprises a metal electrode.   The touch panel according to any one of claims 1 to 9, wherein an end of the drive electrode and / or the sense electrode not connected to the metal wiring is covered with a metal material.

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