JP2013206198A - Touch sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a touch sensor having electrode pattern crossing areas in which a dot-like or linear high-luminance part is not generated and a dot-like or linear black part where liquid crystal screen display is hardly viewed is less conspicuous.SOLUTION: A touch sensor includes plural transparent first electrode patterns and plural transparent second electrode patterns formed on one surface of a transparent substrate and extending in mutually crossing directions. The first electrode patterns include plural first island-shaped electrode parts formed with spaces therebetween in a first direction on the substrate and first bridge wiring parts formed and electrically connected between adjacent first island-shaped electrode parts. The second electrode patterns include plural second island-shaped electrode parts formed with spaces therebetween in a second direction crossing the first direction. Second bridge wiring parts electrically connected between adjacent second island-shaped electrode parts of the second electrode patterns are formed so as to straddle transparent insulator films formed on the first bridge wiring parts of the first electrode patterns. Thin metallic wires of the second bridge wiring parts are blackened.

Description

  The present invention relates to a projection-type capacitive touch sensor disposed on the front surface of a display device or the like.

  Conventionally, electrostatic capacitance touch sensors and other devices employed in mobile phones and the like are stacked as shown in FIG. 4, for example (Patent Document 1).

  The example shown in FIG. 4 shows an example of a liquid crystal display device 70, a projection-type capacitive touch sensor 71 disposed on the front surface thereof, and a cover glass 72 disposed on the front surface thereof. In FIG. 4, a pair of transparent substrates 81, 82 constituting the display device 70 sandwich a liquid crystal 83 in a space sealed with a sealing material 84. In addition, a liquid crystal display electrode 85 is formed on the transparent substrates 81 and 82, and a polarizing plate 86 is provided. Reference numeral 87 denotes a driving IC. The driving IC 87 is connected to a control board (not shown) serving as a transmission source of image data via a flexible board 88.

  A capacitive touch sensor 71 including a transparent substrate 91 provided with a sensor electrode 92 is disposed on the front surface of the liquid crystal display device 70. In the projected capacitive touch sensor 71, a touch position is detected by detecting a change in electrostatic capacitance that occurs when a conductor such as a human finger approaches the sensor electrode 92 provided on the transparent substrate 91. . More specifically, when a finger approaches the sensor electrode 92, a capacitance is formed between the finger and the sensor electrode 92, and the change is connected via the flexible substrate 95. IC (not shown) detects. FIG. 4 shows an example in which the sensor electrode 92 is formed as a column electrode extending in two directions intersecting each other. For this reason, an insulating film 93 is provided between the first electrode pattern extending in one direction and the first electrode pattern extending in the other direction so as to be in an electrically non-contact state. The capacitive touch sensor 71 is provided with a protective layer 96 for protecting the sensor electrode 92.

  In the example shown in FIG. 4, an example is shown in which a cover glass 72 is further disposed on the capacitive touch sensor 71 via an optical adhesive layer 99. In many cases, the cover glass 72 is decorated such that a black print 97 or a hole is formed on the periphery.

By the way, in Patent Document 1, a plurality of first electrode patterns extending in the first direction and a plurality of second electrode patterns extending in the second direction as sensor electrodes 92 are formed on one surface of the transparent substrate 1. The second electrode pattern is formed in a divided shape (in FIG. 5, two or more first island-shaped electrode portions 201 _c and 201 _d formed at intervals in the first direction and formed therebetween) First bridge wiring portion 202 and two or more second island-shaped electrode portions 201 _a and 201 _b ) spaced apart in the second direction, and further formed without being divided at the intersecting region. The insulating film 9 that covers one electrode pattern in the intersection region and the second island-shaped electrode portion of the second electrode pattern that is divided and formed in the intersection region are formed in a connected state in the intersection region. Wiring, the insulating film 9 being A second bridge wiring portion 4 formed so as to straddle (see FIG. 6), the second bridge wiring portion 4 is formed of a metal material, and the insulating film is formed of a material having shielding properties and insulating properties. Are disclosed.

  In this way, by forming the insulating film 9 provided between the first bridge wiring portion 202 and the second bridge wiring portion 4 of the first electrode pattern formed without being divided in the intersecting region with a shielding material, Deterioration of visibility due to reflection of the bridge wiring 4 made of a metal material, that is, a high-brightness portion that becomes dazzling occurs in the intersection region of the first electrode pattern and the second electrode pattern, and the user views the liquid crystal screen. In this case, it is possible to suppress the occurrence of a malfunction or visual discomfort.

  In Patent Document 1, the capacitive touch sensor having the above-described configuration is manufactured as follows. First, a first electrode pattern extending in a first direction and a second electrode pattern extending in a second direction that intersects the first direction by patterning a transparent conductive film on one surface of the transparent substrate. And forming a transparent electrode pattern having a shape in which the second electrode pattern is divided at an intersection region of the first electrode pattern and the second electrode pattern. Next, by providing an insulating shielding layer made of a material having shielding properties and insulating properties at the intersection region between the first electrode pattern and the second electrode pattern, the first electrode formed without being divided at the intersection region. An insulating film covering the electrode pattern is used. Next, a second bridge wiring portion is formed on the same surface of the transparent substrate on which the insulating shielding layer is formed by patterning with a metal film in which a metal conductive material is formed.

JP 2011-90443 A

  However, in the invention described in Patent Document 1, the insulating film 9 having a shielding property is formed wider than the second bridge wiring portion 4 made of a metal material formed so as to straddle the insulating film 9. In order to prevent the contact between the second bridge wiring portion 4 and the first bridge wiring portion 202 of the first electrode pattern intersecting with the second bridge wiring portion 4 in consideration of the positional deviation tolerance of each layer laminated in the intersecting region. is there. As a result, the visibility of the insulating film 9 having the shielding property is deteriorated due to the wide light shielding, that is, a black portion that always shields the lit pixel in a crossing region of the transparent electrode pattern is generated in a dot shape or a line shape. A new problem arises that hinders.

  Therefore, an object of the present invention is to solve the above-mentioned problem, and a point-like or linear high-luminance portion that becomes dazzling occurs in a crossing region of the transparent electrode pattern, or a liquid crystal screen display becomes difficult to see. Another object is to provide a touch sensor in which a linear black portion does not stand out.

According to the first aspect of the present invention, there is provided a touch sensor having a plurality of transparent first electrode patterns and a plurality of transparent second electrode patterns formed on one surface of a transparent substrate and extending in directions intersecting each other. There,
The first electrode pattern is:
A plurality of first island-shaped electrode portions formed at intervals in a first direction on the substrate;
A first bridge wiring portion electrically connected and formed between the adjacent first island-shaped electrode portions,
The second electrode pattern is:
A plurality of second island-shaped electrode portions formed on the substrate and spaced apart in a second direction intersecting the first direction;
Furthermore, an electrical connection is made between the second island electrode portions adjacent to the second electrode pattern so as to straddle at least the transparent insulating film formed on the first bridge wiring portion of the first electrode pattern. A touch sensor is provided in which a second bridge wiring portion connected to is formed, and the second bridge wiring portion is a black metal fine wire.

  Moreover, according to the 2nd aspect of this invention, the blackening of the said metal fine wire provides the touch sensor of a 1st aspect which is based on black plating.

  According to a third aspect of the present invention, there is provided the touch sensor according to the first aspect, wherein the blackening of the fine metal wire is due to electrodeposition coating.

  According to a fourth aspect of the present invention, there is provided the touch sensor according to the first aspect, wherein the blackening of the thin metal wire is due to a chemical conversion treatment.

  According to a fifth aspect of the present invention, there is provided the touch sensor according to any one of the first to fourth aspects, wherein the thin metal wire is any one of copper, aluminum, and nickel.

  Moreover, according to the 65th aspect of the present invention, there is further provided the touch sensor according to any one of the 1st to 5th aspects, wherein a polarizing plate is provided on the front surface.

  In the touch sensor of the present invention, the bridge wiring portion formed between the island-shaped electrode portions of the divided electrode pattern is formed by blackening the metal thin wire, and is formed so as to straddle the transparent insulating film. Configure. Therefore, since the bridge wiring portion made of the metal material is not reflected by blackening, a dotted or linear high-luminance portion that is dazzled in the intersecting region of the transparent electrode pattern does not occur. Further, since the light is shielded not by the width of the insulating film but by the width of the blackened bridge wiring portion, the dot-like or linear black portion that makes it difficult to see the liquid crystal screen display does not stand out in the intersecting region of the transparent electrode pattern.

It is a fragmentary top view which shows the structure of the touch sensor which concerns on 1st Embodiment. It is the elements on larger scale near an intersection area. FIG. 3 is a cross-sectional view taken along line AA ′ in FIG. 2. It is explanatory drawing which shows the structural example of the electronic device containing an electrostatic capacitance touch sensor. It is explanatory drawing which shows the example of the patterning of a transparent electrode. It is explanatory drawing which expands and shows the state in which the transparent electrode, the insulating film, and the bridge | bridging wiring were formed in the transparent substrate in a prior art.

[Embodiment 1]
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram illustrating an example of a touch sensor. FIG. 2 is a partially enlarged view near the intersection region. FIG. 3 is a partially enlarged sectional view taken along line II in FIG. A projection capacitive touch sensor 101 shown in FIG. 1 includes a single transparent substrate 1 and a sensor electrode 14 formed on the transparent substrate 1. A touch position is detected by detecting a change in capacitance that occurs when a conductor such as a human finger approaches the sensor electrode 14 provided on the transparent substrate 1. Since the approach of the finger is detected by the capacitance change, it is not necessary for the finger to touch the sensor electrode 14 directly.

  More specifically, when the finger approaches the sensor electrode 14, a capacitance is formed between the finger and the sensor electrode 14, and the change is electrostatically connected via a flexible substrate (not shown). The touch position is detected by detecting the capacitance sensor IC (not shown). The sensor electrode 14 and the flexible substrate are connected by the lead wiring 5. The capacitance sensor IC may be mounted on the flexible substrate or may be mounted on the transparent substrate 1.

  In the example shown in FIG. 1, the sensor electrode 14 has an X electrode pattern 10 as a plurality of first electrode patterns and a Y electrode pattern 20 as a plurality of second electrode patterns on one surface of the transparent substrate 1.

  The X electrode patterns 10 extend along the X-axis direction as the first direction in the drawing, and a plurality of X-electrode patterns 10 are arranged at intervals in the Y-axis direction. The Y electrode patterns 20 extend along the Y-axis direction as the second direction in the drawing, and a plurality of Y electrode patterns 20 are arranged at intervals in the X-axis direction. In addition, since the X electrode pattern 10 and the Y electrode pattern 20 intersect, the Y electrode pattern 20 is formed in a divided shape in the intersecting region.

  The X electrode pattern 10 integrally includes a plurality of first island electrode portions 12 arranged at intervals in the X-axis direction and a first bridge wiring portion 11 that connects adjacent first island electrode portions 12 to each other. It has a film. The first island-like electrode portion 12 is formed in a rectangular shape in plan view, and is arranged so that one diagonal line is along the X axis.

  The Y electrode pattern 20 has a plurality of second island-shaped electrode portions 22 arranged at intervals in the Y-axis direction. The second island-shaped electrode portion 22 is formed in a rectangular shape in plan view, and is arranged so that one diagonal line is along the Y axis. The first island-like electrode portion 12 and the second island-like electrode portion 22 are alternately arranged (checkered arrangement) in the X-axis direction and the Y-axis direction, and are rectangular first and second island-like electrode portions. 12 and 22 are arranged in a matrix in a plan view.

  Further, in the transparent X electrode pattern 10 formed in a shape that is not divided at the intersecting region, the transparent insulating film 3 is provided so as to cover the first bridge wiring portion 11. Further, in the transparent second electrode pattern formed by being divided at the intersecting region, the wiring is formed to connect the adjacent second island-shaped electrode portions 22 in the intersecting region, A second bridge wiring portion 30 is provided so as to straddle the transparent insulating film 3 (see FIGS. 2 and 3). That is, the second island-shaped electrode portions 22 adjacent to each other in the second electrode pattern 20 are electrically connected by the second bridge wiring portion 30 that is separate from the transparent electrode pattern. In the present invention, the second bridge wiring portion 30 crosses the transparent insulating film 3 so that the upper surface of the insulating film 3 is completely traversed by the second bridge wiring portion 30 longer than the width of the insulating film 3. Means that.

  In addition, the routing wiring 5 is formed on the peripheral portion of the transparent substrate 1, and one end thereof is connected to the X electrode pattern 10 and the Y electrode pattern 20, and signals sensed by the X electrode pattern 10 and the Y electrode pattern 20 are externally transmitted. It can be sent. The other end of the routing wiring 5 is connected to a driving unit and an electric signal conversion / calculation unit (both not shown) provided in the touch sensor or in an external device.

  The transparent substrate 1 is an electrically insulating substrate, such as a glass substrate, a PET (polyethylene terephthalate) film, a PC (polycardnate) film, a COP (cycloolefin polymer) film, or a PVC (polyvinyl chloride) film. Etc. In particular, the COP film is preferable because it not only has excellent optical isotropy, but also has excellent dimensional stability and, in turn, processing accuracy. In addition, when the transparent substrate 1 is a glass substrate, what is necessary is just a thickness of 0.3 mm-3 mm. Moreover, when the transparent substrate 1 is a resin film, the thickness should just be 20 micrometers-3 mm.

  As a material constituting the transparent X electrode pattern 10 and the Y electrode pattern 20, a transparent conductive film, for example, metal oxide such as indium tin oxide (ITO), zinc oxide aluminum (AZO), indium oxide zinc (IZO), etc. It is a thing. Further, the transparent conductive film is formed with a thickness of about several tens to several hundreds of nanometers, and it is necessary that the transparent conductive film is not easily etched with an etching solution used for patterning formation of the second bridge wiring portion 30 made of a thin metal wire described later. It is. And it is preferable to show a light transmittance of 80% or more and a surface resistance value of several mΩ to several hundred Ω.

  As the transparent electrical insulating substance constituting the transparent insulating film 3, for example, an inorganic material such as SiO2 or an organic resin material such as photolithography resin can be used.

  In the present embodiment, the second bridge wiring portion 30 and the routing wiring 5 are formed by blackening metal thin wires. As the material of the fine metal wire, a metal such as copper, aluminum, nickel, iron, gold, silver, chromium, titanium, or an alloy obtained by combining these metals can be used. Of these, it is desirable to use copper, aluminum, nickel, etc. from the viewpoint of high conductivity, easy processing, and low cost.

  These fine metal wires can be blackened by black plating. For example, black nickel plating treatment, chromate plating treatment, black ternary alloy plating treatment using tin, nickel, and copper, black ternary alloy plating treatment using tin, nickel, and molybdenum may be performed.

  Further, the blackening of the fine metal wires can be performed by electrodeposition coating. In black electrodeposition coating, a black paint in which a black pigment is dispersed in an electrodeposition resin is used. Examples of the black pigment include carbon black, and a conductive black pigment is preferable. Further, the electrodeposition resin may be an anionic resin or a cationic resin, and specifically, an acrylic resin, a polyester resin, an epoxy resin, etc., these electrodeposition resins are respectively It is used alone or in combination of two or more.

  Further, the blackening of the fine metal wires can be performed by chemical conversion treatment such as sulfurization treatment or oxidation treatment. Sulfurization treatment and oxidation treatment can be performed by a known method.

In the present specification, the blackening “black” is preferably one having a lightness of L ^* of 1 to 20 and a chromaticity of a ^* and b ^* of +5 to −5, respectively. The lightness and chromaticity are measured by a color difference meter. In this specification, the lightness and chromaticity are also adopted in the L ^* a ^* b ^* color system (JIS Z 8729) defined by the International Commission on Illumination (CIE). Stipulated). The lightness means that the smaller the value is, the more black it is and it is hard to see without reflecting light, and the theoretical minimum value is zero. Chromaticity represents coordinates on the chromaticity diagram, and represents hue and saturation. In the L ^* a ^* b ^* color system, coordinates where the values of a ^* b ^* are both 0 represent a theoretical achromatic color. When the brightness is in the range of 1 to 20 with L ^* , the surface of the fine metal wire is black and it is difficult to distinguish the difference with the naked eye. The lightness is preferably as low as L ^* , but the desired effect is usually obtained even at 10-20. On the other hand, if the chromaticity is a ^* and b ^* from +5 to −5, it is difficult to identify the hue with the naked eye. When a ^* exceeds +5, the fine metal wire looks red, when it is less than −5, it appears green, when b ^* exceeds +5, it appears yellow, and when it is less than −5, it appears blue. A more preferable range of a ^* is +4 to −2, and a more preferable range of b ^* is +2 to −5.

  By configuring the second bridge wiring portion 30 made of the fine metal wire and the routing wiring 5 with the black metal fine wire, the second bridge wiring portion 30 made of the fine metal wire does not reflect, so the X electrode pattern 10 And the dotted | punctate or linear high-intensity part which becomes dazzling in the cross | intersection area | region of the Y electrode pattern 20 does not arise. Further, as shown in FIG. 2, since the light is shielded not by the width of the insulating film but by the width of the second bridge wiring portion 30 made of a thin metal wire, a liquid crystal screen display can be seen in the intersection region of the X electrode pattern 10 and the Y electrode pattern 20. The point-like or linear black part which becomes difficult does not stand out.

  Next, an example of a method for manufacturing the touch sensor 101 of this embodiment will be described.

  First, a transparent conductive film is formed on one surface of the transparent substrate 1 using a sputtering method or the like, and the formed transparent conductive film is patterned using a photolithographic technique or the like to extend in the X-axis direction. The sensor electrode 14 is formed by processing the X electrode pattern 10 having a shape and the Y electrode pattern 20 having a divided shape extending in the Y-axis direction.

  Next, a transparent insulating material is formed on the same surface of the transparent substrate 1 on which the sensor electrode 14 is formed (the surface on which the sensor electrode 14 is formed) using a spin coating method or the like, By patterning using a lithography technique, the transparent insulating film 3 is patterned and formed in a region where the X electrode pattern 10 and the Y electrode pattern 20 of the sensor electrode 14 intersect.

  Next, a conductive material made entirely of a metal material is formed on the same surface of the transparent substrate 1 on which the transparent insulating film 3 is formed (the surface on which the insulating film 3 is formed) using a sputtering method or the like. Then, after blackening the metal film by black plating, electrodeposition coating, or chemical conversion treatment, the blackened metal film is formed into a predetermined pattern shape using a photolithography technique. That is, the second bridge wiring portion 30 made of a thin metal wire that is electrically connected between the adjacent second island-like electrode portions 22 of the second electrode pattern so as to straddle over the respective insulating films 3, and the lead wiring 5 And at the same time. Since the second bridge wiring portion 30 and the routing wiring 5 are simultaneously formed in this way, the number of processes can be reduced.

[Embodiment 2]
In the second embodiment, the material of the routing wiring 5 is not the same material as the second bridge wiring portion 30 made of a thin metal wire as in the first embodiment, but a different material. For example, the lead wiring 5 can be formed by screen printing such as silver paste. In this case, compared with the first embodiment, even a material unsuitable for the second bridge wiring portion 30 can be used for the routing wiring 5, and there is an advantage that the range of material selection is widened. Moreover, thickness adjustment, such as forming thickly, is also possible.

[Example of changes]
The present invention is not limited to the above embodiments. For example, when the transparent substrate 1 is a resin film, it may give a phase difference of λ / 4. Here, giving a phase difference of λ / 4 ideally means giving a phase difference of λ / 4 to all wavelengths in the visible light region. However, if the phase difference at a wavelength of 550 nm is λ / 4, there is no practical problem even if the phase difference at other wavelengths is slightly deviated from λ / 4. The retardation value (Δnd) at a wavelength of 550 nm is preferably 125 to 150 nm, and more preferably 131 to 145 nm.

  Further, the resin film of the transparent substrate 1 is not limited to a λ / 4 retardation film single layer. For example, a laminate in which a λ / 4 retardation film and an optical isotropic film are bonded may be used. As an optically isotropic film, for example, a retardation (Δnd) value is 30 nm or less. Furthermore, the transparent substrate 1 may use the laminated body which adhere | attached (lambda) / 2 phase difference film and (lambda) / 4 phase difference film for the resin film.

  In addition to the above-described film obtained by sputtering the metal oxide, the transparent conductive film includes a conductive polymer film such as PEDOT: poly (3,4-ethylenedioxythiophene), carbon nanotube, carbon nanohorn, carbon nanowire, carbon nanofiber, graphite. A film in which ultrafine conductive carbon fibers such as fibrils or ultrafine conductive fibers made of a silver material are dispersed in a polymer material functioning as a binder may be formed by various printing methods, coating methods, ink jets, or the like. These are excellent in flexibility, and when the transparent substrate 1 is a resin film, the capacitive touch sensor 10 can be attached along a 2.5-dimensional curved surface or a 3-dimensional curved surface.

  The lead wiring 5 may be made of the same material as the sensor electrode 14. In this case, the sensor electrode 14 and the lead wiring 5 can be formed simultaneously. Furthermore, the routing wiring 5 may be a multilayer film including a layer made of the same material as the sensor electrode 14 and a layer made of a different material.

  Further, a protective layer (not shown) may be further formed on the surface of the transparent substrate 1 on which the sensor electrode 14, the insulating film 3, the second bridge wiring portion 30 made of a thin metal wire, and the routing wiring 5 are formed. . For example, a film of SiO2 material may be formed by a sputtering method using a mask. For example, the SiO 2 film is formed on the entire surface excluding the connection portion where the routing wiring 5 and the flexible substrate are connected.

  Further, the projected capacitive touch sensor of the present invention may be either a self-capacitance (Self Capacitance) method or a mutual capacitance (Mutual Capacitance) method. Further, the touch sensor 101 of each of the above embodiments is configured to have the X electrode pattern 10 as the first electrode pattern and the Y electrode pattern 20 as the second electrode pattern, but conversely as the first electrode pattern. The Y electrode pattern and the X electrode pattern 20 as the second electrode pattern may be provided.

  In addition, the projected capacitive touch sensor of the present invention may further include a polarizing plate on the front surface. When the touch sensor having this configuration is arranged on the color filter, a so-called “On-Cell type” liquid crystal display device in which a touch panel function is built in between the polarizing plate and the color filter is obtained.

  The technical contents and technical features of the present invention have been disclosed as described above. However, those skilled in the art to which the present invention belongs will not depart from the technical idea of the present invention based on the teachings and disclosure of the present invention. Various substitutions and additions can be made. Accordingly, the scope of protection of the present invention is not limited to that disclosed in the examples, and includes various substitutions and additions that are not different from the present invention, and is included in the scope of the appended claims. is there.

1 Transparent substrate 3 Insulating film (transparent)
4 Second bridge wiring part (reflection)
9 Insulation film (shielding)
14, 92 Sensor electrode 5 Lead-out wiring 10 X electrode pattern 11, 202 First bridge wiring part 12, 201 _c , 201 _d First island electrode part 13, 23 Connection part 20 Y electrode pattern 22, 201 _a , 201 _b 2nd island electrode part 30 2nd bridge wiring part (blackening)
71,101 Touch sensor

Claims (6)

A touch sensor having a plurality of transparent first electrode patterns and a plurality of transparent second electrode patterns formed on one surface of a transparent substrate and extending in directions intersecting each other,
The first electrode pattern is:
A plurality of first island-shaped electrode portions formed at intervals in a first direction on the substrate;
A first bridge wiring portion electrically connected and formed between the adjacent first island-shaped electrode portions,
The second electrode pattern is:
A plurality of second island-shaped electrode portions formed on the substrate and spaced apart in a second direction intersecting the first direction;
Furthermore, an electrical connection is made between the second island electrode portions adjacent to the second electrode pattern so as to straddle at least the transparent insulating film formed on the first bridge wiring portion of the first electrode pattern. A touch sensor, characterized in that a second bridge wiring portion connected to the substrate is formed, and the second bridge wiring portion is a black metal fine wire.   The touch sensor according to claim 1, wherein the metal fine wire is blackened by black plating.   The touch sensor according to claim 1, wherein the blackening of the thin metal wire is due to electrodeposition coating.   The touch sensor according to claim 1, wherein the blackening of the thin metal wire is performed by chemical conversion treatment.   The touch sensor according to claim 1, wherein the thin metal wire is any one of copper, aluminum, and nickel.   The touch sensor according to claim 1, further comprising a polarizing plate on the front surface.

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