JPWO2018193940A1 - Conductive substrate - Google Patents

Abstract

A transparent substrate, a metal layer formed on at least one surface of the transparent substrate, and a blackening layer formed on the metal layer, the blackening layer is a simple substance of nickel, Provided is a conductive substrate which is a roughened plating layer containing nickel oxide, nickel hydroxide, and copper.

Description

  The present invention relates to a conductive substrate.

  The capacitance-type touch panel converts information on the position of a nearby object on the panel surface into an electric signal by detecting a change in capacitance caused by an object near the panel surface. Since the conductive substrate used for the capacitive touch panel is provided on the surface of the display, the material of the conductive layer of the conductive substrate is required to have low reflectance and to be hardly visible.

  For this reason, as a material of a conductive layer used for a conductive substrate for a touch panel, a material having low reflectance and being hardly visible is used, and is formed on a transparent substrate or a transparent film.

  For example, as disclosed in Patent Literature 1, a transparent conductive film for a touch panel in which an ITO (indium tin oxide) film is formed as a transparent conductive film on a polymer film has been conventionally used.

  By the way, in recent years, the size of the screen provided with the touch panel has been increased, and correspondingly, a conductive substrate such as a transparent conductive film for the touch panel has been required to have a larger area. However, since ITO has a high electric resistance value, there is a problem that it is not possible to cope with an increase in the area of the conductive substrate.

  Therefore, in order to suppress the electric resistance of the conductive substrate, a method has been proposed in which a copper mesh wiring is used as the conductive layer and the surface of the copper mesh wiring is blackened.

  For example, Patent Document 2 discloses a step of forming a resist layer on a copper thin film supported by a film, a step of processing at least the resist layer into a striped wiring pattern and a drawing wiring pattern by a photolithography method, There is disclosed a method of manufacturing a film-shaped touch panel sensor including a step of forming a striped copper wiring and a lead-out copper wiring by removing the etched copper thin film by etching, and a step of blackening the copper wiring.

  However, in Patent Literature 2, a method of forming a striped copper wiring by etching and then blackening the copper wiring is adopted, and there is a problem in productivity because the number of manufacturing steps is increased.

  Therefore, the inventors of the present invention, with respect to a conductive substrate having a metal layer and a blackening layer formed on a transparent substrate, etching the metal layer and the blackening layer, a conductive substrate having a desired wiring pattern and By doing so, the manufacturing process was reduced, and a method of manufacturing a conductive substrate capable of obtaining high productivity was studied.

JP-A-2003-151358 JP 2013-206315 A

  However, the reactivity of the metal layer and the blackening layer with respect to the etchant may be significantly different. Therefore, if the metal layer and the blackening layer are simultaneously etched, any of the layers may not be etched into a desired shape, or may not be uniformly etched in a plane, resulting in dimensional variation. There was a problem that the blackening layer and the blackened layer could not be etched at the same time.

  In view of the above problems of the related art, an aspect of the present invention is to provide a conductive substrate including a metal layer and a blackening layer that can be simultaneously etched.

In order to solve the above-described problems, in one aspect of the present invention,
A transparent substrate,
A metal layer formed on at least one surface of the transparent substrate,
Having a blackening layer formed on the metal layer,
The blackening layer provides a conductive substrate that is a roughened plating layer containing nickel alone, nickel oxide, nickel hydroxide, and copper.

  According to one aspect of the present invention, a conductive substrate provided with a metal layer and a blackening layer that can be simultaneously etched can be provided.

FIG. 2 is a cross-sectional view of the conductive substrate according to the embodiment of the present invention. FIG. 2 is a cross-sectional view of the conductive substrate according to the embodiment of the present invention. FIG. 2 is a cross-sectional view of the conductive substrate according to the embodiment of the present invention. FIG. 2 is a cross-sectional view of the conductive substrate according to the embodiment of the present invention. FIG. 2 is a top view of a conductive substrate provided with a mesh wiring according to the embodiment of the present invention. FIG. 4 is a configuration example of a cross-sectional view taken along line AA ′ of FIG. 3. FIG. 4 is another configuration example of a cross-sectional view taken along line AA ′ of FIG. 3. FIG. 4 is an explanatory diagram of a side etching amount.

Hereinafter, an embodiment of a conductive substrate and a method of manufacturing the conductive substrate of the present invention will be described.
(Conductive substrate)
The conductive substrate of the present embodiment can include a transparent substrate, a metal layer formed on at least one surface of the transparent substrate, and a blackening layer formed on the metal layer. The blackening layer can be a roughened plating layer containing nickel alone, nickel oxide, nickel hydroxide, and copper.

  Note that the conductive substrate in the present embodiment refers to a substrate having a metal layer and a blackening layer on the surface of a transparent substrate before patterning the metal layer and the like, and a substrate having the metal layer and the like patterned, that is, a wiring A substrate. The conductive substrate after the patterning of the metal layer and the blackening layer can transmit light because the transparent base material includes a region not covered by the metal layer or the like, and is a transparent conductive substrate.

  Here, first, each member included in the conductive substrate of the present embodiment will be described below.

  The transparent substrate is not particularly limited, and an insulating film that transmits visible light, a glass substrate, or the like can be preferably used.

  As the insulating film that transmits visible light, for example, resin films such as polyamide-based films, polyethylene terephthalate-based films, polyethylene naphthalate-based films, cycloolefin-based films, polyimide-based films, and polycarbonate-based films can be preferably used. . In particular, PET (polyethylene terephthalate), COP (cycloolefin polymer), PEN (polyethylene naphthalate), polyamide, polyimide, polycarbonate, and the like can be more preferably used as the material of the insulating film that transmits visible light.

  The thickness of the transparent substrate is not particularly limited, and can be arbitrarily selected according to the strength, capacitance, light transmittance, and the like required for a conductive substrate. The thickness of the transparent substrate can be, for example, not less than 10 μm and not more than 200 μm. In particular, when used for touch panel applications, the thickness of the transparent substrate is preferably from 20 μm to 120 μm, more preferably from 20 μm to 100 μm. When used for touch panel applications, for example, especially in applications where the thickness of the entire display is required to be reduced, the thickness of the transparent substrate is preferably 20 μm or more and 50 μm or less.

  The total light transmittance of the transparent substrate is preferably higher. For example, the total light transmittance is preferably 70% or more, and more preferably 80% or more. When the total light transmittance of the transparent substrate is in the above range, for example, when used for touch panel applications, the visibility of the display can be sufficiently ensured.

  The total light transmittance of the transparent substrate can be evaluated by a method specified in JIS K7361-1.

  Next, the metal layer will be described.

  The material constituting the metal layer is not particularly limited, and a material having an electric conductivity suitable for the use can be selected. However, copper is used as the material constituting the metal layer because of its excellent electrical properties and ease of etching. Is preferred. That is, the metal layer preferably contains copper.

  When the metal layer contains copper, the material constituting the metal layer is, for example, at least one selected from the group consisting of Cu (copper) and metals such as Ni, Mo, Ta, Ti, V, Cr, Fe, Mn, Co, and W. It is preferable that the material be a copper alloy of one or more metals or a material containing copper and one or more metals selected from the above metal group. Further, the metal layer may be a copper layer made of copper.

  That is, when the metal layer contains copper, the metal layer can be one or more layers selected from copper, a metal containing copper, and a copper alloy. When the metal layer contains copper, the metal layer is preferably a copper or copper alloy layer. This is because the copper or copper alloy layer has particularly high electric conductivity (conductivity), and wiring can be easily formed by etching. Further, the copper or copper alloy layer is particularly apt to undergo side etching, which will be described later, and the conductive substrate of the present embodiment can suppress side etching.

  The method of forming the metal layer is not particularly limited, but in a portion where the transparent base material of the patterned conductive substrate is exposed, an adhesive is provided between another member and the metal layer in order not to reduce light transmittance. It is preferable to form them without disposing them. That is, the metal layer is preferably arranged directly on the upper surface of another member. In addition, the metal layer can be formed and arranged, for example, on an adhesion layer described later or on the upper surface of the transparent substrate. For this reason, the metal layer is preferably formed and arranged directly on the adhesion layer or on the upper surface of the transparent substrate.

  In order to directly form a metal layer on the upper surface of another member, the metal layer preferably has a metal thin film layer formed by using a dry plating method. Although there is no particular limitation on the dry plating method, for example, a vapor deposition method, a sputtering method, an ion plating method, or the like can be used. In particular, a sputtering method is preferably used because the thickness can be easily controlled.

  In the case where the metal layer is made thicker, a metal thin film layer can be formed by dry plating, and then the metal plating layer can be laminated by wet plating. Specifically, for example, on a transparent substrate or an adhesion layer, a metal thin film layer is formed by a dry plating method, the metal thin film layer is used as a power supply layer, and a metal plating layer is formed by electrolytic plating, which is a type of wet plating method. Can be formed.

  When the metal layer is formed only by the dry plating method as described above, the metal layer can be constituted by a metal thin film layer. When a metal layer is formed by combining a dry plating method and a wet plating method, the metal layer can be constituted by a metal thin film layer and a metal plating layer.

  Forming and disposing a metal layer directly on a transparent substrate or an adhesion layer without using an adhesive by forming a metal layer only by a dry plating method or a combination of a dry plating method and a wet plating method as described above. be able to.

  The thickness of the metal layer is not particularly limited, and can be arbitrarily selected according to the magnitude of the current supplied to the wiring, the wiring width, and the like when the metal layer is used as the wiring.

  However, when the metal layer becomes thicker, it takes time to perform etching for forming a wiring pattern, so that side etching is liable to occur, which may cause problems such as difficulty in forming a fine line. Therefore, the thickness of the metal layer is preferably 5 μm or less, more preferably 3 μm or less.

  In addition, from the viewpoint of lowering the resistance value of the conductive substrate and supplying a sufficient current, for example, the metal layer preferably has a thickness of 50 nm or more, more preferably 60 nm or more, and more preferably 150 nm or more. More preferably, it is the above.

  When the metal layer has a metal thin film layer and a metal plating layer as described above, the total of the thickness of the metal thin film layer and the thickness of the metal plating layer is preferably within the above range.

  In any case where the metal layer is composed of the metal thin film layer or the case where the metal layer is composed of the metal thin film layer and the metal plating layer, the thickness of the metal thin film layer is not particularly limited. The thickness is preferably not less than 700 nm and not more than 700 nm.

  Next, the blackening layer will be described.

  Since the metal layer has a metallic luster, the wiring reflects light only when the wiring is formed by etching the metal layer on the transparent base material. For example, when used as a wiring substrate for a touch panel, the visibility of the display is reduced. There was a problem of doing. Therefore, a method of providing a blackening layer has been studied. However, the reactivity of the metal layer and the blackening layer with the etchant may be significantly different. If the metal layer and the blackening layer are simultaneously etched, the metal layer and the blackening layer cannot be etched into a desired shape. And there are problems such as dimensional variations. For this reason, in the case of a conductive substrate that has been conventionally studied, it is necessary to etch the metal layer and the blackening layer in separate steps, and it is difficult to etch the metal layer and the blackening layer simultaneously, that is, in one step. Met.

  Therefore, the inventors of the present invention provide a blackened layer that can be etched simultaneously with a metal layer, that is, excellent reactivity with an etchant, and can be patterned into a desired shape even when etching is performed simultaneously with a metal layer. A blackening layer capable of suppressing the occurrence was examined. The black layer contains nickel alone, nickel oxide, nickel hydroxide, and copper, so that the reactivity of the black layer with respect to the etchant can be made substantially equal to that of the metal layer. Was found.

  As described above, the blackened layer of the conductive substrate of the present embodiment can include a simple substance of nickel, nickel oxide, nickel hydroxide, and copper.

  Here, the state of copper contained in the blackening layer is not particularly limited, but copper can be contained as one or more types selected from, for example, a simple substance of copper and a copper compound. Examples of the copper compound include copper oxide and copper hydroxide.

  For this reason, the blackening layer contains, for example, a simple substance of nickel, nickel oxide, and nickel hydroxide, and is further selected from a simple substance of copper, that is, metallic copper, copper oxide, and copper hydroxide. One or more types can be contained.

  Since the blackening layer contains nickel oxide and nickel hydroxide as described above, the blackening layer has a color that can suppress light reflection on the surface of the metal layer, and exhibits a function as a blackening layer. be able to.

  In addition, since the blackening layer also contains one or more types selected from copper, for example, a simple substance of copper and a compound of copper, the reactivity of the blackening layer with respect to the etching solution can be made equal to that of the metal layer. For this reason, even when the metal layer and the blackening layer are simultaneously etched, both layers can be etched into a desired shape, and can be uniformly etched in a plane, thereby suppressing the occurrence of dimensional variation. Become. That is, it is possible to simultaneously etch the metal layer and the blackening layer.

  The proportion of each component contained in the blackening layer is not particularly limited, and may be arbitrarily determined according to the degree of suppression of light reflection required for the conductive substrate, the degree of reactivity to the etchant, and the like. You can choose. However, from the viewpoint of sufficiently increasing the reactivity with respect to the etching solution, for example, regarding the blackened layer, the number of nickel atoms determined from the Ni 2P spectrum and the Cu LMM spectrum measured by X-ray photoelectron spectroscopy (XPS) is 100. In this case, the ratio of the number of copper atoms is preferably 5 or more and 90 or less. That is, it is preferable that the nickel and copper contained in the blackening layer have a ratio of the number of atoms, where nickel is 100 and copper is 5 or more and 90 or less. The ratio of the number of copper atoms when the number of nickel atoms is 100 is more preferably 7 or more and 90 or less, and even more preferably 7 or more and 65 or less.

  Here, the number of nickel atoms means the number of all nickel atoms contained in the blackening layer, and forms not only nickel existing alone but also a compound such as nickel oxide. Including nickel.

  In addition, the peak separation analysis of the Ni 2P spectrum measured by XPS for the blackened layer was performed, and the calculated nickel simplex contained in the blackened layer, that is, nickel oxide when the number of atoms of metal nickel was 100, was calculated. The number of atoms of nickel is preferably 15 or more and 280 or less, and the number of nickel atoms of nickel hydroxide is preferably 10 or more and 220 or less. This is because the blackening layer contains nickel oxide and nickel hydroxide in a predetermined ratio with respect to the metal nickel, thereby suppressing the blackening layer from reflecting light on the surface of the metal layer. This is because the color can be made particularly suitable for

  When measuring the blackened layer by XPS as described above, for example, it is necessary to remove 10 nm from the outermost surface of the blackened layer by Ar ion etching or the like so that the internal state can be analyzed. preferable.

  Furthermore, the blackening layer of the conductive substrate of the present embodiment has a surface, specifically, a surface opposite to the surface of the blackening layer facing the transparent substrate, that is, when performing patterning as described later. It is preferable that the surface on which the resist is disposed is a roughened plating layer (roughened layer) having a roughened surface.

  A conductive substrate in which a metal layer and a blackening layer are laminated in that order on a transparent base material, a resist having a shape corresponding to a wiring pattern to be formed is arranged on the blackening layer, and the metal layer is etched. , And the blackening layer can have a desired pattern.

  However, when etching the metal layer and the blackening layer, side etching may occur in which etching proceeds not only in the thickness direction of the metal layer but also in the plane direction. Therefore, it is conceivable that the resist pattern is corrected to be thicker than the pattern derived from the desired wiring pattern in consideration of the amount of side etching so that a desired shape can be obtained for the wiring in which the metal layer is patterned. . However, making the resist pattern thicker in consideration of the side etching amount has been an obstacle to miniaturization of the wiring pattern.

  Therefore, the inventors of the present invention have studied and found that the blackened layer is a roughened plating layer in which the surface of the blackened layer, that is, the surface opposite to the surface facing the transparent substrate is a roughened surface. , The occurrence of side etching can be suppressed. This is because the surface of the blackened layer is roughened so that the adhesion between the blackened layer and the resist can be improved when the resist is disposed, and the blackened layer and the resist can be etched when etching is performed. It is considered that it is possible to suppress the etching liquid from entering between these two.

  From the viewpoint of particularly suppressing the occurrence of side etching, the blackened layer preferably contains one or more types of crystals selected from granular crystals and needle-like crystals.

  When the blackening layer contains granular crystals, the blackening layer preferably contains granular crystals having an average crystal grain size of 50 nm or more and 150 nm or less.

  This is because the blackened layer contains granular crystals, and the average crystal grain size is 50 nm or more, so that the surface of the blackened layer is roughened to increase the adhesion between the blackened layer and the resist, and the side etching is performed. This is because generation can be particularly suppressed. In addition, the blackening layer contains granular crystals, and by setting the average crystal grain size to 150 nm or less, the blackening layer can have a color that is particularly suitable for suppressing light reflection on the surface of the metal layer. Because you can. When the blackening layer contains granular crystals, the average grain size is more preferably 70 nm or more and 150 nm or less.

  When the blackening layer contains granular crystals, the standard deviation σ of the grain size of the granular crystals is preferably 10 nm or more, more preferably 15 nm or more. This means that by setting the standard deviation σ to 10 nm or more, the granular crystals contained in the blackening layer have a certain degree of variation or more, and the adhesion between the blackening layer and the resist can be particularly enhanced. Because. The upper limit of the standard deviation σ of the grain size of the granular crystals is not particularly limited, but may be, for example, 100 nm or less.

  The grain size of the granular crystal is defined as a circle having a minimum size that completely covers the granular crystal to be measured when the roughened surface of the blackened layer is observed with a scanning electron microscope or the like as described below. Means the diameter of

  When the blackened layer contains needle-like crystals, the blackened layer has an average length of 100 nm to 300 nm, an average width of 30 nm to 80 nm, and an average aspect ratio of 2.0 to 4.5. It is preferable to include a morphological crystal.

  This is because the blackened layer contains needle-shaped crystals, the average length of which is 100 nm or more, the average width is 30 nm or more, and the aspect ratio is 2.0 or more. This is because the adhesion between the chemically treated layer and the resist can be enhanced, and the occurrence of side etching can be particularly suppressed. In addition, the blackening layer contains needle-like crystals, the average length of which is 300 nm or less, the average width is 80 nm or less, and the average aspect ratio is 4.5 or less. This is because a color suitable for suppressing the reflection of light can be obtained.

  When the blackening layer contains needle-like crystals, it is more preferable that the average length is 120 nm or more and 260 nm or less, the average width is 40 nm or more and 70 nm or less, and the average aspect ratio is 2.5 or more and 4.5 or less.

  When the blackening layer contains needle-like crystals, the standard deviation σ of the length, width, and aspect ratio of the needle-like crystals is preferably 10 nm or more, 5 nm or more, and 0.5 or more, respectively. This means that the standard deviation σ of the length, width, and aspect ratio of the needle-like crystal is in the above-described range, so that the needle-like crystal contained in the blackened layer has a certain degree of variation or more. This is because the adhesion between the activated layer and the resist can be particularly enhanced. The upper limit of the standard deviation σ of the length, width, and aspect ratio of the needle-shaped crystal is not particularly limited, but may be, for example, 100 nm or less, 50 nm or less, and 5 or less, respectively.

  Note that the length and width of the needle-shaped crystal are the length and length of the long side of the needle-shaped crystal, respectively, when the roughened surface of the blackened layer is observed with a scanning electron microscope or the like as described below. It means the length of the side. The aspect ratio is a value obtained by dividing the length by the width.

  The average grain size, the average length, the average width, the average aspect ratio, and the standard deviation σ of the crystals contained in the blackening layer are determined by, for example, roughening the blackening layer by using a scanning electron microscope (SEM). It can be measured and calculated from the observation image when the surface is observed.

  The specific conditions for observing the roughened surface of the blackening layer are not particularly limited, but it is preferable to magnify 50,000 times at an arbitrary position, for example. When the blackened layer contains granular crystals, the grain size of 20 arbitrarily selected granular crystals is measured in one visual field, and the average value of the grain sizes of the 20 granular crystals is calculated as the average crystal size. It can be of a grain size. Further, the standard deviation of the crystal grain size can be calculated from the measured value of the crystal grain size of the 20 granular crystals and the calculated average crystal grain size.

  When the blackening layer contains needle-like crystals, the length and width of the arbitrarily selected 20 needle-like crystals in one visual field can be similarly measured to calculate the aspect ratio. Then, the average value of the length, width, and aspect ratio of the 20 needle-like crystals can be used as the average length, average width, and average aspect ratio. Further, the standard deviation can be calculated from the measured values of the length and width of the 20 needle-shaped crystals, the calculated values of the aspect ratio, and the calculated average length, average width, and average aspect ratio.

  In addition, it is preferable to select the position of the observation visual field so that 20 or more granular crystals or needle-like crystals are included in one visual field. The average crystal grain size, or the average length, the average width, and the average aspect ratio may be calculated using crystals or needle-like crystals.

  As described above, since the size of crystals such as granular crystals can be calculated for the roughened surface of the blackened layer by a scanning electron microscope or the like, the above-described granular crystals and needle-like crystals are not included in the roughened surface of the blackened layer. It can also be said to be a contained crystal.

  The method for forming the blackened layer is not particularly limited, and any method can be selected as long as it contains each of the above-described components and can be formed into a roughened plating layer. However, it is preferable to use a wet method since the composition of the blackening layer can be relatively easily controlled so as to contain the above-described components.

  As the wet method, it is particularly preferable to use an electrolytic plating method.

  The black plating solution used when forming the black layer by the electrolytic plating method may be prepared so that the black layer having the above composition can be formed, and the composition is not particularly limited. Absent. For example, a black plating solution containing nickel ions, copper ions, and a pH adjuster can be preferably used.

  The concentration of each component in the blackening plating solution is not particularly limited, and may be arbitrarily selected according to the degree of suppressing light reflection on the metal layer surface required for the formed blackening layer. Can be.

  For example, the nickel ion concentration in the black plating solution is preferably 2.0 g / L or more, and more preferably 3.0 g / L or more. This is because, by setting the nickel ion concentration in the black plating solution to 2.0 g / L or more, the black layer becomes a color particularly suitable for suppressing the reflection of light on the surface of the metal layer. This is because the reflectivity of the light can be suppressed.

  The upper limit of the nickel ion concentration in the black plating solution is not particularly limited, but is preferably, for example, 20.0 g / L or less, and more preferably 15.0 g / L or less. This is because by controlling the nickel ion concentration in the blackening plating solution to 20.0 g / L or less, the nickel component in the formed blackening layer is suppressed from becoming excessive, and the surface of the blackening layer becomes bright nickel. This is because it is possible to prevent the surface from becoming plating-like and to suppress the reflectance of the conductive substrate.

  Further, the copper ion concentration in the black plating solution is preferably 0.005 g / L or more, and more preferably 0.008 g / L or more. This is because when the copper ion concentration in the black plating solution is 0.005 g / L or more, the black layer is made to have a color particularly suitable for suppressing the reflection of light on the surface of the metal layer, and the black layer is etched. This is because the reactivity to the liquid can be increased, and even when the blackening layer is etched together with the metal layer, it can be patterned into a desired shape.

  The upper limit of the copper ion concentration in the black plating solution is not particularly limited, but is preferably, for example, 4.0 g / L or less, more preferably 1.02 g / L or less. This is because by controlling the concentration of copper ions in the blackening plating solution to 4.0 g / L or less, the reactivity of the formed blackening layer with respect to the etching solution is suppressed from becoming too high, and the blackening layer is formed of metal. This is because a color that is particularly suitable for suppressing the reflection of light on the layer surface can be used, and the reflectance of the conductive substrate can be suppressed.

  When preparing the blackening plating solution, the method of supplying nickel ions and copper ions is not particularly limited, and for example, they can be supplied in a salt state. For example, a sulfamate or a sulfate can be suitably used. The type of salt may be the same type of salt for each metal element, or different types of salts may be used at the same time. Specifically, for example, a black plating solution can be prepared using the same kind of salt, such as nickel sulfate and copper sulfate. Further, a black plating solution can be prepared by simultaneously using different types of salts such as nickel sulfate and copper sulfamate.

  And as a pH adjuster, alkali metal hydroxide can be preferably used. This is because by using an alkali metal hydroxide as a pH adjuster, the reflectance of a conductive substrate having a blackening layer formed using the blackening plating solution can be particularly reduced. When an alkali metal hydroxide is used as the pH adjuster, it is not clear why the reflectance of a conductive substrate having a blackened layer formed using the blackening plating solution can be suppressed to be low. It is considered that hydroxide ions supplied into the plating solution can promote precipitation of nickel oxide. By promoting the precipitation of nickel oxide, the blackened layer can be made a color particularly suitable for suppressing light reflection on the surface of the metal layer. Therefore, it is presumed that the reflectance of the conductive substrate having the blackening layer can be particularly suppressed.

  As the alkali metal hydroxide serving as a pH adjuster, for example, one or more kinds selected from sodium hydroxide, potassium hydroxide, and lithium hydroxide can be used. In particular, it is more preferable that the alkali metal hydroxide serving as the pH adjuster is at least one selected from sodium hydroxide and potassium hydroxide. This is because sodium hydroxide and potassium hydroxide are particularly easily available and are excellent in cost.

  Although the pH of the black plating solution of the present embodiment is not particularly limited, it is preferably, for example, 4.0 or more and 5.2 or less, and more preferably 4.5 or more and 5.0 or less.

  This is because, by setting the pH of the blackening plating solution to 4.0 or more, when the blackening layer is formed using the blackening plating solution, the occurrence of color unevenness in the blackening layer is more reliably suppressed. This is because a blackened layer having a color that can particularly suppress light reflection can be formed. Further, by setting the pH of the black plating solution to 5.2 or less, it is possible to suppress precipitation of a part of components of the black plating solution.

  Further, the blackening plating solution may further contain a complexing agent. As the complexing agent, for example, amidosulfuric acid can be preferably used. When the blackening plating solution contains amide sulfuric acid, it is possible to form a blackening layer having a color particularly suitable for suppressing light reflection on the surface of the metal layer.

  The content of the complexing agent in the blackening plating solution is not particularly limited, and can be arbitrarily selected according to the degree of suppression of the reflectance required for the blackening layer to be formed.

  For example, when using amidosulfuric acid as a complexing agent, the concentration of amidosulfuric acid in the black plating solution is not particularly limited, but is preferably, for example, 1 g / L or more and 50 g / L or less, and 5 g / L or more and 20 g / L. The following is preferred. This is because when the concentration of amidosulfuric acid is 1 g / L or more, the blackening layer can be made a color particularly suitable for suppressing the reflection of light on the surface of the metal layer, and the reflectance of the conductive substrate can be suppressed. It is. Further, even if an amide sulfuric acid is excessively added, the effect of suppressing the reflectance of the conductive substrate is not increased. Therefore, the amount is preferably 50 g / L or less as described above.

  The shape and size of the crystals contained in the blackening layer can be selected by adjusting the pH of the plating solution and the current density when forming the blackening layer. For example, by increasing the pH of the plating solution or increasing the current density during film formation, needle-like crystals are likely to be generated, and by reducing the pH of the plating solution or decreasing the current density during film formation, the granularity is increased. Crystals tend to form.

  For this reason, for example, a preliminary test is performed, and conditions can be selected so as to obtain a blackened layer containing crystals of a desired shape and size.

  The thickness of the blackening layer is not particularly limited, and can be arbitrarily selected according to the degree of suppression of light reflection required for the conductive substrate.

  The thickness of the blackening layer is preferably, for example, 50 nm or more, and more preferably 70 nm or more. The blackening layer has a function of suppressing light reflection by the metal layer. However, when the thickness of the blackening layer is small, light reflection by the metal layer may not be sufficiently suppressed. On the other hand, it is preferable to set the thickness of the blackening layer to 50 nm or more because reflection on the surface of the metal layer can be more reliably suppressed.

  The upper limit of the thickness of the blackening layer is not particularly limited. However, if the thickness is larger than necessary, the time required for etching when forming the wiring becomes longer, which leads to an increase in cost. For this reason, the thickness of the blackening layer is preferably 350 nm or less, more preferably 200 nm or less, and even more preferably 150 nm or less.

  Further, the conductive substrate may be provided with any layer other than the above-mentioned transparent substrate, metal layer and blackening layer. For example, an adhesion layer can be provided.

  A configuration example of the adhesion layer will be described.

  As described above, the metal layer can be formed on the transparent substrate, but when the metal layer is formed directly on the transparent substrate, the adhesion between the transparent substrate and the metal layer may not be sufficient. . Therefore, when the metal layer is formed directly on the upper surface of the transparent substrate, the metal layer may peel off from the transparent substrate during the manufacturing process or during use.

  Therefore, in the conductive substrate of the present embodiment, an adhesion layer can be disposed on the transparent substrate in order to increase the adhesion between the transparent substrate and the metal layer. That is, a conductive substrate having an adhesion layer between the transparent substrate and the metal layer can be used.

  By arranging the adhesion layer between the transparent substrate and the metal layer, the adhesion between the transparent substrate and the metal layer can be enhanced, and the separation of the metal layer from the transparent substrate can be suppressed more reliably.

  Further, the adhesion layer can also function as a blackening layer. For this reason, it is also possible to suppress the reflection of light from the metal layer due to light from the lower surface side of the metal layer, that is, from the transparent substrate side.

  The material constituting the adhesion layer is not particularly limited, and the adhesion strength between the transparent substrate and the metal layer, the required degree of suppression of light reflection on the surface of the metal layer, and the use of a conductive substrate It can be arbitrarily selected according to the degree of stability to the environment (for example, humidity or temperature).

  The adhesion layer preferably contains, for example, at least one or more metals selected from Ni, Zn, Mo, Ta, Ti, V, Cr, Fe, Co, W, Cu, Sn, and Mn. Further, the adhesion layer may further include one or more elements selected from carbon, oxygen, hydrogen, and nitrogen.

  The adhesion layer may include a metal alloy containing at least two or more metals selected from Ni, Zn, Mo, Ta, Ti, V, Cr, Fe, Co, W, Cu, Sn, and Mn. Also in this case, the adhesion layer may further include one or more elements selected from carbon, oxygen, hydrogen, and nitrogen. At this time, the metal alloy containing at least two or more metals selected from Ni, Zn, Mo, Ta, Ti, V, Cr, Fe, Co, W, Cu, Sn, and Mn is a Cu-Ti-Fe alloy. Alternatively, Cu-Ni-Fe alloy, Ni-Cu alloy, Ni-Zn alloy, Ni-Ti alloy, Ni-W alloy, Ni-Cr alloy, Ni-Cu-Cr alloy can be preferably used.

  The method for forming the adhesion layer is not particularly limited, but is preferably formed by a dry plating method. As the dry plating method, for example, a sputtering method, an ion plating method, an evaporation method, or the like can be preferably used. When the adhesion layer is formed by a dry method, it is more preferable to use a sputtering method because the thickness can be easily controlled. As described above, one or more elements selected from carbon, oxygen, hydrogen, and nitrogen can be added to the adhesion layer. In this case, a reactive sputtering method can be more preferably used.

  When the adhesion layer contains one or more elements selected from carbon, oxygen, hydrogen, and nitrogen, one or more elements selected from carbon, oxygen, hydrogen, and nitrogen are contained in the atmosphere when the adhesion layer is formed. Can be added to the adhesion layer by adding a gas containing For example, when adding carbon to the adhesion layer, at least one selected from carbon monoxide gas and carbon dioxide gas, oxygen gas when adding oxygen, hydrogen gas and hydrogen gas when adding hydrogen. In the case of adding nitrogen, one or more selected from water can be added with nitrogen gas in an atmosphere for performing dry plating.

  A gas containing one or more elements selected from carbon, oxygen, hydrogen, and nitrogen is preferably added to an inert gas to provide an atmosphere gas for dry plating. Although it does not specifically limit as an inert gas, For example, argon can be preferably used.

  By forming the adhesion layer by the dry plating method as described above, the adhesion between the transparent substrate and the adhesion layer can be improved. And since an adhesion layer can contain a metal as a main component, for example, adhesion with a metal layer is also high. For this reason, peeling of a metal layer can be suppressed by arrange | positioning an adhesion layer between a transparent base material and a metal layer.

  Although the thickness of the adhesion layer is not particularly limited, it is, for example, preferably 3 nm to 50 nm, more preferably 3 nm to 35 nm, and still more preferably 3 nm to 33 nm.

  When the adhesion layer also functions as a blackening layer, that is, when the reflection of light on the metal layer is suppressed, the thickness of the adhesion layer is preferably 3 nm or more as described above.

  Although the upper limit of the thickness of the adhesion layer is not particularly limited, the time required for film formation and the time required for etching when forming wiring are increased even if the thickness is more than necessary, which leads to an increase in cost. Will be invited. For this reason, as described above, the thickness of the adhesion layer is preferably set to 50 nm or less, more preferably 35 nm or less, and further preferably 33 nm or less.

  Next, a configuration example of the conductive substrate will be described.

  As described above, the conductive substrate of the present embodiment can have a transparent substrate, a metal layer, and a blackening layer. Further, a layer such as an adhesion layer can be optionally provided.

  A specific configuration example will be described below with reference to FIGS. 1A and 1B. 1A and 1B show examples of cross-sectional views of the conductive substrate of the present embodiment in a plane parallel to a laminating direction of a transparent base material, a metal layer, and a blackening layer.

  The conductive substrate of the present embodiment can have a structure in which, for example, a metal layer and a blackening layer are laminated in this order on at least one surface of the transparent substrate from the transparent substrate side.

  Specifically, for example, as in the case of the conductive substrate 10A shown in FIG. 1A, the metal layer 12 and the blackening layer 13 may be laminated one by one on the one surface 11a side of the transparent base material 11 in that order. it can. The surface A of the blackening layer 13 which is the surface of the blackening layer 13 opposite to the surface facing the transparent substrate 11 can be a roughened surface. Further, like the conductive substrate 10B shown in FIG. 1B, the metal layers 12A and 12B and the black layer are provided on one surface 11a side and the other surface (the other surface) 11b side of the transparent substrate 11, respectively. Layers 13A and 13B can be laminated one by one in that order. Also in this case, in the blackening layers 13A and 13B, the surface A and the surface B which are opposite to the surface facing the transparent substrate 11 can be roughened.

  Further, as an arbitrary layer, for example, a configuration in which an adhesion layer is provided may be employed. In this case, for example, a structure in which an adhesion layer, a metal layer, and a blackening layer are formed in this order on at least one surface of the transparent substrate from the side of the transparent substrate can be employed.

  Specifically, for example, as in a conductive substrate 20A shown in FIG. 2A, an adhesion layer 14, a metal layer 12, and a blackening layer 13 are laminated in this order on one surface 11a side of the transparent substrate 11. be able to.

  Also in this case, a configuration in which an adhesion layer, a metal layer, and a blackening layer are laminated on both surfaces of the transparent substrate 11 can be adopted. Specifically, like the conductive substrate 20B shown in FIG. 2B, the adhesion layers 14A and 14B and the metal layers 12A and 12B are respectively formed on one surface 11a side and the other surface 11b side of the transparent base material 11. And the blackening layers 13A and 13B can be laminated in that order.

  1B and FIG. 2B, when a metal layer, a blackening layer, and the like are laminated on both surfaces of the transparent substrate, the layers laminated above and below the transparent substrate 11 with the transparent substrate 11 as a symmetry plane are symmetrical. Although an example in which they are arranged is shown, the present invention is not limited to such an embodiment. For example, in FIG. 2B, the configuration on the one surface 11a side of the transparent substrate 11 is the same as the configuration in FIG. 1B, in which the metal layer 12A and the blackening layer 13A are laminated in this order without providing the adhesion layer 14A. The layers laminated on and under the transparent substrate 11 may have an asymmetric configuration.

  By the way, in the conductive substrate of the present embodiment, by providing a metal layer and a blackening layer on a transparent substrate, the reflection of light by the metal layer is suppressed, and the reflectance of the conductive substrate is suppressed. Can be.

  The degree of reflectance of the conductive substrate of the present embodiment is not particularly limited. For example, in order to enhance the visibility of a display when used as a conductive substrate for a touch panel, the reflectance is preferably lower. Is good. For example, the average reflectance of light having a wavelength of 400 nm or more and 700 nm or less is preferably 15% or less, and more preferably 10% or less.

  The reflectance can be measured by irradiating the blackened layer of the conductive substrate with light. Specifically, for example, as shown in FIG. 1A, when the metal layer 12 and the blackening layer 13 are stacked in this order on one surface 11a side of the transparent base material 11, the blackening layer 13 is irradiated with light. The surface A is irradiated with light and can be measured. In the measurement, light having a wavelength of 400 nm or more and 700 nm or less is applied to the blackening layer 13 of the conductive substrate at a wavelength of 1 nm, for example, as described above, and the average of the measured values is defined as the reflectance of the conductive substrate. be able to.

  The conductive substrate of the present embodiment can be preferably used as a conductive substrate for a touch panel. In this case, the conductive substrate may be provided with a mesh wiring.

  The conductive substrate provided with the mesh-shaped wiring can be obtained by etching the metal layer and the blackening layer of the conductive substrate of the present embodiment described above, and in some cases, the adhesion layer.

  For example, a mesh-like wiring can be formed by two-layer wiring. FIG. 3 shows a specific configuration example. FIG. 3 shows a view of the conductive substrate 30 provided with the mesh-like wiring as viewed from the upper surface side in the laminating direction of the metal layer or the like. The transparent substrate and the metal layer are patterned so that the wiring pattern is easy to understand. Layers other than the formed wirings 31A and 31B are omitted. The wiring 31B seen through the transparent substrate 11 is also shown.

  The conductive substrate 30 shown in FIG. 3 has the transparent base material 11, a plurality of wirings 31A parallel to the Y-axis direction in the figure, and wirings 31B parallel to the X-axis direction. The wirings 31A and 31B are formed by etching a metal layer, and a blackening layer (not shown) is formed on the upper or lower surface of the wirings 31A and 31B. The blackening layer is etched in the same shape as the wirings 31A and 31B.

  The arrangement of the transparent substrate 11 and the wirings 31A and 31B is not particularly limited. 4A and 4B show configuration examples of the arrangement of the transparent substrate 11 and the wiring. 4A and 4B correspond to cross-sectional views taken along line AA 'in FIG.

  First, as shown in FIG. 4A, wirings 31A and 31B may be arranged on the upper and lower surfaces of the transparent base material 11, respectively. In FIG. 4A, on the upper surface of the wiring 31A and the lower surface of the wiring 31B, blackening layers 32A and 32B etched in the same shape as the wiring are arranged.

  Also, as shown in FIG. 4B, one set of transparent base materials 11 is used, and wirings 31A and 31B are arranged on the upper and lower surfaces with one transparent base material 11 interposed therebetween. 11 may be arranged. Also in this case, the blackened layers 32A and 32B etched in the same shape as the wiring are arranged on the upper surfaces of the wirings 31A and 31B. As described above, an adhesion layer may be provided in addition to the metal layer and the blackening layer. For this reason, in either case of FIGS. 4A and 4B, for example, an adhesive layer can be provided between one or both of the wiring 31 </ b> A and the wiring 31 </ b> B and the transparent substrate 11. When the adhesion layer is provided, it is preferable that the adhesion layer is also etched into the same shape as the wirings 31A and 31B.

  The conductive substrate having mesh-shaped wirings shown in FIGS. 3 and 4A is, for example, a conductive substrate having metal layers 12A and 12B and blackening layers 13A and 13B on both surfaces of a transparent substrate 11 as shown in FIG. 1B. It can be formed from a conductive substrate.

  Describing as an example the case of forming using the conductive substrate of FIG. 1B, first, the metal layer 12A and the blackening layer 13A on one surface 11a side of the transparent base material 11 are parallel to the Y-axis direction in FIG. 1B. Etching is performed so that a plurality of linear patterns are arranged at predetermined intervals along the X-axis direction. Note that the X-axis direction in FIG. 1B means a direction parallel to the width direction of each layer. The Y-axis direction in FIG. 1B means a direction perpendicular to the plane of the paper in FIG. 1B.

  Then, a plurality of linear patterns parallel to the X-axis direction in FIG. 1B are formed along the Y-axis direction at predetermined intervals by forming the metal layer 12B and the blackening layer 13B on the other surface 11b side of the transparent substrate 11 at predetermined intervals. Etching is performed so as to be arranged.

  Through the above operation, the conductive substrate having the mesh-shaped wirings shown in FIGS. 3 and 4A can be formed. In addition, the etching of both surfaces of the transparent substrate 11 can be performed simultaneously. That is, the etching of the metal layers 12A and 12B and the blackening layers 13A and 13B may be performed simultaneously. Further, in FIG. 4A, the conductive substrate further having an adhesion layer patterned in the same shape as the wirings 31A and 31B between the wirings 31A and 31B and the transparent substrate 11 is the conductive substrate shown in FIG. 2B. It can be manufactured by performing etching in the same manner using.

  The conductive substrate having the mesh wiring shown in FIG. 3 can also be formed by using two conductive substrates shown in FIG. 1A or 2A. The case where two conductive substrates of FIG. 1A are formed will be described as an example. For each of the two conductive substrates shown in FIG. 1A, a metal layer 12 and a blackening layer 13 are formed by a plurality of layers parallel to the X-axis direction. The etching is performed so that the linear patterns are arranged at predetermined intervals along the Y-axis direction. Then, by bonding the two conductive substrates in such a manner that the linear patterns formed on the respective conductive substrates by the above-mentioned etching process cross each other, a conductive substrate having mesh wiring is obtained. be able to. The surface to be bonded when bonding the two conductive substrates is not particularly limited. For example, the surface A in FIG. 1A on which the metal layer 12 and the like are stacked and the other surface 11b in FIG. 1A on which the metal layer 12 and the like are not stacked are bonded to form the structure shown in FIG. 4B. You can also.

  Further, for example, the other surfaces 11b in FIG. 1A where the metal layer 12 and the like of the transparent base material 11 are not laminated may be attached to each other so that the cross section has the structure shown in FIG. 4A.

  4A and 4B, the conductive substrate further having an adhesion layer patterned between the wirings 31A and 31B and the transparent substrate 11 in the same shape as the wirings 31A and 31B is shown in FIG. 1A. It can be manufactured by using the conductive substrate shown in FIG. 2A instead of the conductive substrate.

  The width of the wiring and the distance between the wirings in the conductive substrate having the mesh wirings shown in FIGS. 3, 4A, and 4B are not particularly limited. You can choose.

  However, according to the conductive substrate of the present embodiment, it has a blackening layer containing a simple substance of nickel, nickel oxide, nickel hydroxide, and copper, and has a blackening layer and a metal layer. Are simultaneously etched and patterned, the blackening layer and the metal layer can be patterned into a desired shape. Further, occurrence of side etching can be suppressed. Specifically, for example, a wiring having a wiring width of 10 μm or less can be formed. For this reason, it is preferable that the conductive substrate of the present embodiment include a wiring having a wiring width of 10 μm or less. The lower limit of the wiring width is not particularly limited, but may be, for example, 3 μm or more.

  Further, FIGS. 3, 4A, and 4B show examples in which mesh-shaped wirings (wiring patterns) are formed by combining linear wirings, but the present invention is not limited to such an embodiment. Can be formed in any shape. For example, each of the wirings constituting the mesh wiring pattern may be formed into various shapes such as a jagged line (a zigzag straight line) so that moire (interference fringes) does not occur between the image and the display.

  Such a conductive substrate having a mesh-like wiring composed of two layers of wirings can be preferably used, for example, as a conductive substrate for a projection-type capacitive touch panel.

  The conductive substrate of the present embodiment has a structure in which a blackening layer is stacked on a metal layer formed on at least one surface of a transparent base material. Since the blackened layer contains a simple substance of nickel, nickel oxide, nickel hydroxide, and copper, when the metal layer and the blackened layer are patterned by etching, the blackened layer is formed. Can be easily patterned into a desired shape.

  Further, the blackened layer is a roughened plating layer in which the surface opposite to the surface facing the transparent substrate is a roughened surface. Therefore, the adhesion to the resist is high, and the occurrence of side etching can be suppressed.

Further, the blackening layer included in the conductive substrate of the present embodiment can sufficiently suppress the reflection of light on the surface of the metal layer, and can be a conductive substrate in which the reflectance is suppressed. Further, for example, when used for a touch panel or the like, the visibility of the display can be improved.
(Method of manufacturing conductive substrate)
Next, a configuration example of the method for manufacturing a conductive substrate according to the present embodiment will be described.

The method for manufacturing a conductive substrate according to the present embodiment can include the following steps.
Forming a metal layer on at least one surface of the transparent substrate;
A blackening layer forming step of forming a blackening layer on the metal layer.

  Then, in the blackening layer forming step, a blackening layer containing nickel alone, nickel oxide, nickel hydroxide, and copper can be formed.

  Hereinafter, the method for manufacturing the conductive substrate of the present embodiment will be specifically described.

  The above-described conductive substrate can be suitably manufactured by the method for manufacturing a conductive substrate according to the present embodiment. Therefore, except for the points described below, the configuration can be the same as that of the above-described conductive substrate, and the description is partially omitted.

  The transparent substrate used for the metal layer forming step can be prepared in advance. The kind of the transparent substrate to be used is not particularly limited, but as described above, a transparent substrate such as an insulating film (resin film) that transmits visible light or a glass substrate can be preferably used. The transparent substrate can be cut in advance to an arbitrary size if necessary.

  The metal layer preferably has a metal thin film layer as described above. Further, the metal layer may include a metal thin film layer and a metal plating layer. For this reason, the metal layer forming step can include a step of forming a metal thin film layer by, for example, a dry plating method. Further, the metal layer forming step is a step of forming a metal thin film layer by a dry plating method, and a step of forming a metal plating layer by an electroplating method, which is a kind of a wet plating method, using the metal thin film layer as a power supply layer, May be provided.

  The dry plating method used in the step of forming the metal thin film layer is not particularly limited, and for example, a vapor deposition method, a sputtering method, an ion plating method, or the like can be used. Note that a vacuum evaporation method can be preferably used as the evaporation method. As the dry plating method used in the step of forming the metal thin film layer, it is more preferable to use a sputtering method because the control of the film thickness is particularly easy.

  Next, a step of forming a metal plating layer will be described. The conditions in the step of forming the metal plating layer by the wet plating method, that is, the conditions of the electroplating treatment are not particularly limited, and various conditions according to a conventional method may be employed. For example, a metal plating layer can be formed by supplying a substrate on which a metal thin film layer is formed to a plating tank containing a metal plating solution and controlling the current density and the transport speed of the substrate.

  Next, the blackening layer forming step will be described.

  In the blackening layer forming step, a blackening layer containing nickel alone, nickel oxide, nickel hydroxide, and copper can be formed.

  The blackening layer can be formed by a wet method. Specifically, for example, using a metal layer as a power supply layer, a blackening layer can be formed on a metal layer by an electrolytic plating method in a plating tank containing the above-described blackening plating solution. By forming the blackening layer by the electrolytic plating method using the metal layer as the power supply layer in this way, the blackening layer can be formed on the entire surface of the metal layer opposite to the surface facing the transparent substrate.

  As described above, the blackening layer is preferably a roughened plating layer that is a roughened surface on the surface opposite to the surface facing the transparent substrate. By adjusting the pH and current density of the blackening plating solution when forming the blackening layer, the shape and size of the crystal contained in the blackening layer can be selected. For example, by increasing the pH of the plating solution or increasing the current density during film formation, needle-like crystals are likely to be generated, and by reducing the pH of the plating solution or decreasing the current density during film formation, the granularity is increased. Crystals tend to form.

  For this reason, for example, a preliminary test is performed, and conditions can be selected so as to obtain a blackened layer containing crystals of a desired shape and size.

  The description of the blackening plating solution is omitted because it has already been given.

  In the method for manufacturing a conductive substrate according to the present embodiment, an optional step can be further performed in addition to the above steps.

  For example, when an adhesion layer is formed between a transparent substrate and a metal layer, an adhesion layer forming step of forming an adhesion layer on the surface of the transparent substrate on which the metal layer is to be formed can be performed. When performing the adhesion layer formation step, the metal layer formation step can be performed after the adhesion layer formation step. A thin film layer can be formed.

  In the step of forming the adhesion layer, the method of forming the adhesion layer is not particularly limited, but is preferably formed by a dry plating method. As the dry plating method, for example, a sputtering method, an ion plating method, an evaporation method, or the like can be preferably used. When the adhesion layer is formed by a dry method, it is more preferable to use a sputtering method because the thickness can be easily controlled. Note that one or more elements selected from carbon, oxygen, hydrogen, and nitrogen can be added to the adhesion layer as described above. In this case, a reactive sputtering method can be more preferably used.

  The conductive substrate obtained by the method for manufacturing a conductive substrate according to the present embodiment can be used for various applications such as a touch panel. When used for various applications, it is preferable that the metal layer and the blackening layer included in the conductive substrate of the present embodiment are patterned. When an adhesion layer is provided, it is preferable that the adhesion layer is also patterned. The metal layer, and the blackening layer, and in some cases, the adhesion layer can be patterned according to a desired wiring pattern, for example, and the metal layer, and the blackening layer, and in some cases, the adhesion layer can be patterned in the same shape. It is preferable that it is formed.

  Therefore, the method for manufacturing a conductive substrate according to the present embodiment can include a patterning step of patterning the metal layer and the blackening layer. When the adhesion layer is formed, the patterning step can be a step of patterning the adhesion layer, the metal layer, and the blackening layer.

  The specific procedure of the patterning step is not particularly limited, and can be performed by an arbitrary procedure. For example, in the case of a conductive substrate 10A in which a metal layer 12 and a blackening layer 13 are laminated on a transparent base material 11 as shown in FIG. 1A, first, a resist having a desired pattern is arranged on the surface A on the blackening layer 13. A resist placement step can be performed. Next, an etching step of supplying an etching solution to the surface A on the blackening layer 13, that is, the surface on which the resist is disposed can be performed.

  The etchant used in the etching step is not particularly limited. However, the blackened layer formed by the method for manufacturing a conductive substrate according to the present embodiment exhibits almost the same reactivity to an etchant as the metal layer. For this reason, the etchant used in the etching step is not particularly limited, and an etchant generally used for etching a metal layer can be preferably used.

  As the etchant, for example, a mixed aqueous solution containing at least one selected from sulfuric acid, hydrogen peroxide (hydrogen peroxide solution), hydrochloric acid, cupric chloride, and ferric chloride can be preferably used. The content of each component in the etching solution is not particularly limited.

  The etchant can be used at room temperature, but it can be used after being heated to increase reactivity, for example, it can be used by heating it to 40 ° C. or more and 50 ° C. or less.

  Further, as shown in FIG. 1B, a patterning step for patterning a conductive substrate 10B in which metal layers 12A and 12B and blackening layers 13A and 13B are laminated on one surface 11a and the other surface 11b of the transparent base material 11 is performed. it can. In this case, for example, a resist disposing step of disposing a resist having a desired pattern on the surface A and the surface B on the blackening layers 13A and 13B can be performed. Next, an etching step of supplying an etching solution to the surface A and the surface B on the blackening layers 13A and 13B, that is, the surface on which the resist is disposed can be performed.

  The pattern formed in the etching step is not particularly limited, and may have any shape. For example, in the case of the conductive substrate 10A shown in FIG. 1A, as described above, the pattern is formed so that the metal layer 12 and the blackening layer 13 include a plurality of straight lines or a line that is bent in a zigzag manner. Can be.

  In the case of the conductive substrate 10B shown in FIG. 1B, a pattern can be formed by the metal layer 12A and the metal layer 12B so as to form a mesh wiring. In this case, it is preferable that the blackening layer 13A is patterned so as to have the same shape as the metal layer 12A, and the blackening layer 13B is preferably patterned so as to have the same shape as the metal layer 12B.

  Further, for example, after the metal layer 12 and the like are patterned on the conductive substrate 10A in the patterning step, a laminating step of laminating two or more patterned conductive substrates can be performed. When laminating, for example, by laminating the conductive layers so that the metal layer patterns of the conductive substrates cross each other, it is also possible to obtain a laminated conductive substrate provided with mesh wiring.

  The method for fixing the two or more conductive substrates stacked is not particularly limited, but can be fixed by, for example, an adhesive.

  The conductive substrate obtained by the above-described method for manufacturing a conductive substrate of the present embodiment has a structure in which a blackening layer is laminated on a metal layer formed on at least one surface of a transparent base material. . Since the blackened layer contains a simple substance of nickel, nickel oxide, nickel hydroxide, and copper, the metal layer and the blackened layer are patterned by etching as described above. In this case, the blackening layer can be easily patterned into a desired shape.

  Further, the blackened layer is a roughened plating layer in which the surface opposite to the surface facing the transparent substrate is a roughened surface. Therefore, the adhesion to the resist is high, and the occurrence of side etching can be suppressed.

  In addition, the blackened layer included in the conductive substrate obtained by the method for manufacturing a conductive substrate of the present embodiment is a conductive substrate in which the reflection of light on the surface of the metal layer is sufficiently suppressed and the reflectance is suppressed. Can be. For this reason, for example, when used for applications such as touch panels, the visibility of the display can be improved.

Hereinafter, the present invention will be described with reference to specific examples and comparative examples, but the present invention is not limited to these examples.
(Evaluation method)
The samples prepared in the following experimental examples were evaluated by the following methods.
(1) Component Analysis of Blackening Layer The component analysis of the blackening layer was performed by an X-ray photoelectron spectrometer (manufactured by PHI, type: QuantaSXM). In addition, monochromatic Al (1486.6 eV) was used for the X-ray source.

  As described below, in each of the following experimental examples, a conductive substrate having the structure of FIG. 1A was manufactured. Therefore, the surface A exposed to the outside of the blackening layer 13 in FIG. 1A was subjected to Ar ion etching, and a Ni 2P spectrum and a Cu LMM spectrum within 10 nm from the outermost surface were measured. From the obtained spectrum, the ratio of the number of copper atoms was calculated when the number of nickel atoms contained in the blackening layer was 100. In Table 1, the results are shown as ratios of metal components.

In addition, according to the peak separation analysis of the Ni 2P spectrum, the number of nickel atoms and the number of nickel atoms contained in the blackened layer, which are nickel oxide when the number of metal nickel atoms is 100, and nickel hydroxide are obtained. The number of nickel atoms was calculated. In Table 1, the results are shown as nickel component ratios.
(2) Reflectance measurement Measurement was performed by installing a reflectance measurement unit on an ultraviolet-visible spectrophotometer (model: UV-2600, manufactured by Shimadzu Corporation).

As described later, in each experimental example, a conductive substrate having the structure shown in FIG. 1A was manufactured. For this reason, in the reflectance measurement, light having a wavelength of 400 nm or more and 700 nm or less with respect to the surface A of the blackening layer 13 of the conductive substrate 10A shown in FIG. Irradiation measured the regular reflectance, and the average value was defined as the reflectance (average reflectance) of the conductive substrate.
(3) Etching Characteristics First, a dry film resist (Hitachi Chemical RY3310) was attached to the surface of the blackened layer of the conductive substrate obtained in the following experimental example by a lamination method. Then, ultraviolet exposure was performed through a photomask, and the resist was dissolved and developed with a 1% aqueous solution of sodium carbonate. As a result, a sample having a pattern in which the resist width was changed every 0.5 μm in the range of 3.0 μm to 10.0 μm was prepared. That is, 15 types of linear patterns having a resist width of 3.0 μm, 3.5 μm, 4.0 μm... 9.5 μm, 10.0 μm and different for each 0.5 μm were formed.

  Next, the sample was immersed in an etching solution containing 30% by weight of sulfuric acid and 3% by weight of hydrogen peroxide at 30 ° C. for 40 seconds. Thereafter, the dry film resist was stripped and removed with an aqueous sodium hydroxide solution.

  The obtained sample was observed with a microscope of 200 times, and the minimum value of the wiring width of the metal wiring remaining on the conductive substrate was obtained.

  After the resist is stripped, the smaller the minimum value of the wiring width of the metal wiring remaining on the conductive substrate, and the smaller the remaining amount of the metal wiring remaining around the formed metal wiring, the more the copper layer and the blackening layer are exposed to the etchant. It means that the reactivity is closer to the same. Therefore, when the minimum value of the wiring width of the remaining metal wiring was 3 μm or more and 10 μm or less, and no melting residue was found around the formed metal wiring, it was evaluated as Δ. Further, when the minimum value of the remaining metal wiring was 3 μm or more and 10 μm or less, but there was no practical problem around the formed metal wiring, but a part of the metal wiring remained undissolved, it was evaluated as Δ. When a metal wiring having a wiring width of 10 μm or less could not be formed because the metal wiring was not dissolved in the etching solution, it was evaluated as “Fail”. In the case of ○ or △, it can be said that it is a conductive substrate having a metal layer and a blackening layer that can be etched simultaneously, and can be evaluated as passing.

Table 2 shows the evaluation results, △, Δ, and ×.
(4) Shape and Size of Crystal Contained in Blackening Layer Scanning is performed on the surface opposite to the surface facing the transparent substrate, specifically surface A in FIG. 1A, which is the roughened surface of the blackening layer. Observation was performed using a scanning electron microscope to evaluate the shape and size of the crystal contained in the blackening layer.

  In the evaluation, first, the area was magnified 50,000 times at an arbitrary position on the roughened surface of the blackening layer. Then, the shape of the crystal present in the observation region was observed. When a granular crystal is observed, it is shown as a granular shape, and when a needle-like crystal is observed, it is shown as a needle shape in the column of crystal shape in Table 2.

  Then, when granular crystals were observed, 20 granular crystals to be evaluated were selected, and the average crystal grain size and the standard deviation σ were measured and calculated. The grain size of the granular crystal means the diameter of a circle having the minimum size that completely covers the granular crystal for which the granular crystal is measured.

  When needle-like crystals were observed, 20 needle-like crystals to be evaluated were selected, and the average length, average width, average aspect ratio, and standard deviation σ were measured and calculated.

  When the granular crystal was evaluated, the average value and the standard deviation of the crystal grain size are described in the column of “Grain Size / Length” in Table 2.

  When the needle-shaped crystal was evaluated, the average value and standard deviation of its length are described in the column of “crystal grain size / length” in Table 2, and the average value and standard deviation of the width and the aspect ratio are as follows: These are described in the columns of “width” and “aspect ratio” in Table 2, respectively.

Since each parameter has already been described, the description is omitted here.
(5) Amount of Side Etching First, a dry film resist (Hitachi Kasei RY3310) was attached to the surface of the blackened layer of the conductive substrate obtained in the following experimental example by a laminating method. Then, ultraviolet exposure was performed through a photomask, and the resist was dissolved and developed with a 1% aqueous solution of sodium carbonate. As a result, a sample having a plurality of resists in a linear pattern parallel to each other was prepared on the blackening layer.

  Next, the sample was immersed in a 30 ° C. etching solution containing 10% by weight of sulfuric acid and 3% by weight of hydrogen peroxide.

  About the obtained sample, the cross section parallel to the lamination direction of each layer of the conductive substrate and perpendicular to the linear pattern of the resist was observed without stripping the resist. In this case, as shown in FIG. 5, a cross-sectional shape in which a patterned metal layer 52, a patterned blackening layer 53, and a resist 54 are stacked on a transparent base material 51 is observed. Then, the distance L between the widthwise end 54a of the resist and the widthwise end 52a of the patterned metal layer 52 was measured as the side etching amount.

The conductive substrate was taken out of the etchant 60 seconds, 120 seconds, and 180 seconds after the start of the immersion in the etchant, and after washing, the side etching amount was evaluated as described above. Was.
(Sample preparation conditions)
A conductive substrate was prepared under the conditions described below, and evaluated by the above-described evaluation method. All of Experimental Examples 1 to 10 are examples.
[Experimental example 1]
A conductive substrate having the structure shown in FIG. 1A was manufactured.
(Metal layer forming step)
A copper layer was formed as a metal layer on one surface of a long transparent substrate made of polyethylene terephthalate resin (PET) having a length of 300 m, a width of 250 mm, and a thickness of 100 μm. The transparent substrate made of polyethylene terephthalate resin used as the transparent substrate was evaluated for the total light transmittance according to the method specified in JIS K7361-1 and found to be 97%.

  In the metal layer forming step, a metal thin film layer forming step and a metal plating layer forming step were performed.

  First, the metal thin film layer forming step will be described.

  In the metal thin film layer forming step, the above-mentioned transparent base material was used as the base material, and a copper thin film layer was formed as a metal thin film layer on one surface of the transparent base material.

  In the metal thin film layer forming step, first, the above-mentioned transparent substrate, which was previously heated to 60 ° C. to remove moisture, was placed in a chamber of a sputtering apparatus.

Next, after the inside of the chamber was evacuated to 1 × 10 ⁻³ Pa, an argon gas was introduced, and the pressure in the chamber was set to 1.3 Pa.

  Electric power was supplied to a copper target previously set on the cathode of the sputtering apparatus, and a copper thin film layer was formed on one surface of the transparent substrate so as to have a thickness of 0.7 μm.

  Next, in the metal plating layer forming step, a copper plating layer was formed as the metal plating layer. The copper plating layer was formed by electroplating so that the thickness of the copper plating layer was 0.3 μm.

  By performing the above metal thin film layer forming step and metal plating layer forming step, a copper layer having a thickness of 1.0 μm was formed as a metal layer.

The substrate formed in the metal layer forming step, on which the copper layer having a thickness of 1.0 μm was formed on the transparent substrate, was immersed in 20 g / L sulfuric acid for 30 seconds, washed, and then subjected to the following blackening layer forming step. .
(Blackening layer forming step)
In the blackening layer forming step, a blackening layer was formed on one surface of the copper layer by an electrolytic plating method using a blackening plating solution.

  In addition, a plating solution containing nickel ions, copper ions, amidosulfuric acid, and sodium hydroxide was prepared as a blackening plating solution. Nickel ions and copper ions were supplied to the blackening plating solution by adding nickel sulfate hexahydrate and copper sulfate pentahydrate.

  Each component was added and adjusted so that the concentration of nickel ions in the blackening plating solution was 5 g / L, the concentration of copper ions was 0.03 g / L, and the concentration of amidosulfuric acid was 11 g / L.

  Further, an aqueous solution of sodium hydroxide was added to the black plating solution to adjust the pH of the black plating solution to 4.9.

In the blackening layer forming step, electrolytic plating was performed under the conditions that the temperature of the blackening plating solution was 40 ° C., the current density was 0.10 A / dm ² , and the plating time was 400 seconds, to form a blackening layer.

  The thickness of the formed blackening layer was 110 nm.

With respect to the conductive substrate obtained by the above steps, the component analysis, the reflectance, and the etching characteristic of the blackening layer described above were evaluated. The results are shown in Tables 1 and 2.
[Experimental Examples 2 to 10]
In each experimental example, the nickel ion concentration and the copper ion concentration in the blackening plating solution when forming the blackening layer, the current density when forming the blackening layer, and the plating time were changed as shown in Table 1. Except for this point, a conductive substrate was prepared and evaluated in the same manner as in Experimental Example 1. The results are shown in Tables 1 and 2.

表２に示した結果によると、実験例１〜実験例１０はいずれも、黒化層は、ニッケルの単体と、ニッケル酸化物と、ニッケル水酸化物と、銅とを含有することが確認できた。

According to the results shown in Table 2, in all of Experimental Examples 1 to 10, it was confirmed that the blackened layer contained a simple substance of nickel, nickel oxide, nickel hydroxide, and copper. Was.

  According to the results shown in Table 1, the evaluation results of the etching characteristics were also 〇 or △, and it was confirmed that the conductive substrate was provided with a metal layer and a blackening layer that can be etched simultaneously.

  In particular, when the nickel and copper contained in the blackening layer are in a ratio of the number of atoms of nickel to 100, the etching characteristics of Experimental Examples 1 to 8 in which copper is 7 or more and 90 or less are 〇. It was confirmed that the reflectance was 10% or less. For this reason, the conductive substrates of Experimental Examples 1 to 8 have particularly close reactivity to the etchant between the metal layer and the blackening layer, and the blackening can particularly suppress the reflection of light on the surface of the metal layer. It was confirmed that the layer was provided.

  Furthermore, in Experimental Examples 1 to 10, it was confirmed that the blackened layer had granular or needle-like crystals, and that the occurrence of side etching was also suppressed. That is, the blackened layer was a roughened plating layer in which the surface opposite to the surface facing the transparent substrate was a roughened surface, and it was confirmed that the blackened layer had high adhesion to the resist.

  Although the conductive substrate has been described in the embodiments and the examples, the present invention is not limited to the embodiments and the examples. Various modifications and changes are possible within the scope of the present invention described in the claims.

  This application claims the priority based on Japanese Patent Application No. 2017-081591 filed with the Japan Patent Office on April 17, 2017, and incorporates the entire contents of Japanese Patent Application No. 2017-081591 into this international application. Invite.

10A, 10B, 20A, 20B, 30 Conductive substrate 11, 51 Transparent substrate 12, 12A, 12B, 52 Metal layer 13, 13A, 13B, 32A, 32B, 53 Blackening layer

Claims (7)

A transparent substrate,
A metal layer formed on at least one surface of the transparent substrate,
Having a blackening layer formed on the metal layer,
A conductive substrate, wherein the blackening layer is a roughened plating layer containing a simple substance of nickel, nickel oxide, nickel hydroxide, and copper. Nickel and copper contained in the blackening layer are in a ratio of the number of atoms,
2. The conductive substrate according to claim 1, wherein copper is 5 or more and 90 or less when nickel is 100. 3.   The conductive substrate according to claim 1, further comprising an adhesion layer between the transparent substrate and the metal layer.   The conductive substrate according to any one of claims 1 to 3, wherein the blackening layer includes a granular crystal having an average crystal grain size of 50 nm or more and 150 nm or less.   The blackening layer includes needle-like crystals having an average length of 100 nm or more and 300 nm or less, an average width of 30 nm or more and 80 nm or less, and an average aspect ratio of 2.0 or more and 4.5 or less. The conductive substrate according to any one of the above.   The conductive substrate according to claim 1, wherein a thickness of the blackening layer is 50 nm or more and 350 nm or less.   The conductive substrate according to claim 1, wherein the metal layer is a copper or copper alloy layer.

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