TWI762618B - conductive substrate - Google Patents

Abstract

Provided is a conductive substrate comprising: a transparent substrate; a metal layer formed on at least one surface of the transparent substrate; and a blackened layer formed on the metal layer, wherein the blackened layer is composed of elemental nickel, nickel oxide Coatings, nickel hydroxide, and copper roughening.

Description

conductive substrate

The present invention relates to a conductive substrate.

A capacitive touch panel detects a change in electrostatic capacitance caused by an object approaching the panel surface, and converts information on the position of the approaching object on the panel surface into an electrical signal. Since the conductive substrate used in the capacitive touch panel is provided on the surface of the display, the material of the conductive layer of the conductive substrate needs to have a low reflectivity and is difficult to be visually recognized.

Therefore, as a material of the conductive layer used in the conductive substrate for a touch panel, a material having a low reflectivity and being difficult to be visually recognized is used, and is formed on a transparent substrate or a transparent film.

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

In addition, in recent years, displays having a touch panel have tended to increase in size, and accordingly, an increase in the area of conductive substrates such as transparent conductive films for touch panels has been demanded. However, since ITO has a high resistance value, there is a problem that it cannot cope with an increase in the area of the conductive substrate.

Therefore, in order to suppress the resistance of the conductive substrate, a method of blackening the surface of the copper mesh wiring by using a copper mesh wiring as a conductive layer has been proposed.

For example, Patent Document 2 discloses a method of manufacturing a film-like touch panel sensor, which includes the steps of: forming a resist layer on a copper thin film supported on a film; (photolithography), at least a step of processing the resist layer into a stripe wiring pattern and a wiring pattern for extraction; a step of removing the exposed copper thin film by etching to form a stripe copper wiring and a copper wiring for extraction ; and the step of blackening the copper wiring.

However, in Patent Document 2, after the strip-shaped copper wiring is formed by etching, a method of blackening the copper wiring is adopted, which increases the number of manufacturing steps, and thus has a problem in productivity.

Therefore, the inventors of the present invention have studied a method for producing a conductive substrate, that is, for a conductive substrate in which a metal layer and a blackened layer are formed on a transparent substrate, the metal layer and the blackened layer are Etching is performed as a conductive substrate having a desired wiring pattern, whereby manufacturing steps can be reduced, and a method of manufacturing a conductive substrate with high productivity can be obtained.

[Patent Document 1] Japanese Patent Laid-Open No. 2003-151358

[Patent Document 2] Japanese Patent Application Laid-Open No. 2013-206315

However, there are cases where the reactivity with respect to the etching solution is greatly different between the metal layer and the blackened layer. For this reason, if it is attempted to etch the metal layer and the blackened layer at the same time, there are cases in which either layer cannot be etched into the target shape, and/or uniform etching cannot be performed in the plane, resulting in dimensional non-uniformity. In this case, there is a problem that the metal layer and the blackened layer cannot be etched at the same time.

In view of the above-mentioned problems of the prior art, one aspect of the present invention aims to provide a conductive substrate having a metal layer and a blackened layer that can be etched at the same time.

In order to solve the above-mentioned problems, in one aspect of the present invention, there is provided a conductive substrate comprising: a transparent substrate; a metal layer formed on at least one surface of the transparent substrate; and a blackened layer formed on the metal layer The above-mentioned blackened layer is a roughened plating layer containing elemental nickel, nickel oxide, nickel hydroxide, and copper.

According to an aspect of the present invention, it is possible to provide a conductive substrate having a metal layer and a blackened layer that can be etched at the same time.

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

[FIG. 1A] A cross-sectional view of a conductive substrate according to an embodiment of the present invention.

[FIG. 1B] A cross-sectional view of the conductive substrate according to the embodiment of the present invention.

[FIG. 2A] A cross-sectional view of the conductive substrate according to the embodiment of the present invention.

[FIG. 2B] A cross-sectional view of the conductive substrate according to the embodiment of the present invention.

[FIG. 3] A plan view of a conductive substrate having mesh wiring according to an embodiment of the present invention.

[Fig. 4A] A configuration example of a cross-sectional view taken along the line A-A' in Fig. 3.

[Fig. 4B] Another configuration example of a cross-sectional view taken along the line A-A' in Fig. 3.

[Fig. 5] An explanatory diagram of the amount of side etching.

Hereinafter, one Embodiment of the electroconductive board|substrate and the manufacturing method of the electroconductive board|substrate of this invention is demonstrated.

(conductive substrate)

The conductive substrate of this embodiment may have a transparent base material, a metal layer formed on at least one surface of the transparent base material, and a blackened layer formed on the metal layer. In addition, the blackened layer may be a roughened plating layer containing elemental nickel, nickel oxide, nickel hydroxide, and copper.

It should be noted that the conductive substrate in this embodiment includes a substrate having a metal layer and a blackened layer on the surface of a transparent base material before patterning a metal layer or the like, and a substrate in which the metal layer or the like is subjected to patterning. The patterned substrate, that is, the wiring substrate. The conductive substrate after patterning the metal layer and the blackened layer includes a region of the transparent base material that is not covered by the metal layer or the like, so that light can pass therethrough and is a transparent conductive substrate.

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

Although it does not specifically limit as a transparent base material, An insulator film, a glass substrate, etc. which can transmit (permeate|transmit) visible light can be used suitably.

As an insulator film that transmits visible light, for example, a polyamide-based film, a polyethylene terephthalate (PET)-based film, a polyethylene naphthalate (PEN)-based film, and a cycloolefin-based film can be preferably used. , Polyimide (PI) film, polycarbonate (PC) film and other resin films, etc. In particular, as a material of an insulator film that transmits visible light, PET (polyethylene terephthalate), COP (cycloolefin polymer), PEN (polyethylene naphthalate), polyethylene amide, polyimide, polycarbonate, etc.

The thickness of the transparent base material is not particularly limited, and can be arbitrarily selected according to the strength, electrostatic capacity, light transmittance, and the like required as a conductive substrate. The thickness of the transparent base material may be, for example, 10 μm or more and 200 μm or less. In particular, in the case of use for a touch panel, the thickness of the transparent base material is preferably 20 μm or more and 120 μm or less, and more preferably 20 μm or more and 100 μm or less. In the case of using for a touch panel, for example, in a case where the thickness of the entire display needs to be reduced, for example, the thickness of the transparent base material 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, preferably 80% or more. By setting the total light transmittance of the transparent base material in the above-mentioned range, for example, when it is used for a touch panel, the visibility of the display can be sufficiently ensured.

In addition, the total light transmittance of a transparent base material can be evaluated by the method prescribed|regulated by JISK7361-1.

Next, the metal layer will be described.

The material constituting the metal layer is not particularly limited, and a material having conductivity suitable for the application can be selected, but the material constituting the metal layer is preferable from the viewpoint of superior electrical properties and ease of etching. Use copper. That is, the metal layer preferably contains copper.

When the metal layer contains copper, the material constituting the metal layer is preferably Cu (copper) and at least one selected from the metal group of Ni, Mo, Ta, Ti, V, Cr, Fe, Mn, Co, and W, for example. A copper alloy of one or more metals, or a material containing copper and one or more metals selected from the above-mentioned metal group. In addition, the metal layer may be a copper layer composed of copper.

That is, when the metal layer contains copper, the metal layer may 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 layer of copper or a copper alloy. The reason for this is that, in the layer of copper or copper alloy, the electrical conductivity (conductivity) is high in particular, and wiring can be easily formed by etching. Further, in the layer of copper or copper alloy, side etching (side etching), which will be described later, is particularly likely to occur, but in the conductive substrate of the present embodiment, the side etching can be suppressed.

The method of forming the metal layer is not particularly limited, but in the exposed portion of the transparent base material of the patterned conductive substrate, in order not to reduce the transmittance of light, it is preferable not to arrange an adhesive between other members and the metal layer. Formed in the form of an agent. That is, the metal layer is preferably directly arranged on the upper surface of the other member. In addition, a metal layer can be formed and arrange|positioned on the upper surface of the adhesive layer or transparent base material mentioned later, for example. For this reason, the metal layer is preferably directly formed and arranged on the upper surface of the adhesive layer or the transparent substrate.

In order to directly form the metal layer on the upper surface of the other member, the metal layer preferably has a metal thin film layer formed by a dry plating method. Although it does not specifically limit as a dry plating method, For example, a vapor deposition method, a sputtering method, an ion plating method, etc. can be used. In particular, the sputtering method is preferably used from the viewpoint of easy control of the film thickness.

Moreover, when making a metal layer thicker, after forming a metal thin film layer by a dry plating method, you may laminate|stack a metal plating layer using a wet plating method. Specifically, for example, a metal thin film layer can be formed on a transparent base material or an adhesive layer by a dry plating method, and then the metal thin film layer can be used as a power supply layer by electrolytic plating, which is a type of wet plating method. A metal coating is formed.

In addition, when the metal layer is formed into a film only by the dry plating method as described above, the metal layer may be constituted by a metal thin film layer. In addition, in the case where the metal layer is formed using a dry plating method and a wet plating method in combination, the metal layer may be composed of a metal thin film layer and a metal plating layer.

As described above, by forming the metal layer using only the dry plating method or using a combination of the dry plating method and the wet plating method, the metal layer can be directly formed and arranged on the transparent substrate or the adhesive layer without using an adhesive.

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

However, when the metal layer is thicker, the etching time required for etching to form a wiring pattern is long, so that side etching is likely to occur, and there may be a problem that it is difficult to form thin lines. For this reason, the thickness of the metal layer is preferably 5 μm or less, more preferably 3 μm or less.

In addition, in particular, from the viewpoint of reducing the resistance value of the conductive substrate and enabling sufficient current supply, for example, the thickness of the metal layer is preferably 50 nm or more, preferably 60 nm or more, and more preferably 150 nm or more.

In addition, when a metal layer has a metal thin film layer and a metal plating layer as mentioned above, it is preferable that the sum total of the thickness of a metal thin film layer and the thickness of a metal plating layer exists in the said range.

The thickness of the metal thin film layer is not particularly limited, but is preferably 50 nm or more and 700 nm or less, for example.

Next, the blackened layer will be described.

The metal layer has metallic luster, and when wiring is formed only by etching the metal layer on a transparent substrate, the wiring will reflect light. The problem of reduced visibility. Therefore, a method of providing a blackening layer has been studied. However, the reactivity of the metal layer and the blackened layer to the etchant may be greatly different. If the metal layer and the blackened layer are to be etched at the same time, the metal layer and/or the blackened layer cannot be etched. Problems such as etching into a desired shape or dimensional non-uniformity occur. For this reason, in the previously studied conductive substrate, the metal layer and the blackened layer need to be etched separately in different steps, and it is difficult to etch the metal layer and the blackened layer simultaneously, that is, in one step.

Therefore, the inventors of the present invention have obtained a blackened layer that can be etched at the same time as the metal layer, that is, has excellent reactivity to an etchant, and can be patterned as desired even when it is etched at the same time as the metal layer. The shape and the blackened layer that can also suppress the occurrence of dimensional non-uniformity were studied. From this, it was found that by including elemental nickel, nickel oxide, nickel hydroxide, and copper in the blackened layer, the reactivity of the blackened layer with respect to the etching solution can be made substantially the same as that in the case of the metal layer.

The blackened layer of the conductive substrate of the present embodiment may contain elemental nickel, nickel oxide, nickel hydroxide, and copper as described above.

Here, the state of copper contained in the blackened layer is not particularly limited, but copper may include, for example, one or more kinds selected from copper simple substances and copper compounds. As a copper compound, a copper oxide, a copper hydroxide, etc. are mentioned, for example.

For this purpose, the blackened layer may contain, for example, elemental nickel, nickel oxide, and nickel hydroxide, and may also contain at least one selected from the group consisting of metallic copper, copper oxide, and copper hydroxide, which are elemental copper.

As described above, by including nickel oxide and nickel hydroxide in the blackened layer, the blackened layer can be made into a color that can suppress the reflection of light on the surface of the metal layer, and can function as a blackened layer.

In addition, by further containing copper in the blackened layer, for example, at least one selected from copper simple substance and copper compound, the reactivity of the blackened layer with respect to the etching solution can be made the same as that of the metal layer. For this reason, even when the metal layer and the blackened layer are etched at the same time, both layers can be etched into a target shape, uniform etching can be performed in a plane, and the occurrence of dimensional unevenness can be suppressed. . That is, the metal layer and the blackened layer can be etched at the same time.

The ratio of each component contained in the blackened 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 degree of reactivity with respect to an etching solution, and the like. However, from the viewpoint of sufficiently improving the reactivity with the etching solution, for example, in the case of the blackened layer, it is determined based on the Ni 2P spectrum and the Cu LMM spectrum measured by X-ray photoelectron spectroscopy (XPS). When the atomic number of nickel is 100, the ratio of the atomic number of copper is preferably 5 or more and 90 or less. That is, when nickel and copper contained in a blackened layer are made into 100 in the ratio of the atomic number, copper is preferably 5 or more and 90 or less. When the atomic number of nickel is set to 100, the ratio of the atomic number of copper is preferably 7 or more and 90 or less, and more preferably 7 or more and 65 or less.

In addition, the atomic number of nickel here means the atomic number of all nickel contained in a blackening layer, and not only the nickel which exists as a simple substance but also the nickel which forms compounds, such as nickel oxide, is included.

In addition, peak separation analysis of the Ni 2P spectrum measured on the blackened layer by XPS was also performed, and the calculated number of atoms of elemental nickel contained in the blackened layer, that is, metallic nickel, was 100. The atomic number of nickel which becomes nickel oxide is preferably 15 or more and 280 or less, and the atomic number of nickel which becomes nickel hydroxide is preferably 10 or more and 220 or less. The reason for this is that the blackened layer can be particularly suitable for suppressing the reflection of light on the surface of the metal layer by including nickel oxide and nickel hydroxide in a specific ratio with respect to the metal nickel. color.

In addition, when the blackened layer is measured by XPS as described above, in order to analyze the internal state, for example, it is preferable to remove 10 nm from the outermost surface of the blackened layer by Ar ion etching or the like before measuring. .

In addition, the blackened layer of the conductive substrate of the present embodiment is preferably the surface, specifically, the surface on the opposite side of the surface of the blackened layer facing the transparent substrate, that is, as described later. The surface on which the resist is arranged at the time of patterning is a roughened plating layer (roughened layer) for roughening the surface.

In the case of a conductive substrate in which a metal layer and a blackened layer are sequentially laminated on a transparent substrate, etching is performed by arranging a resist having a shape corresponding to the wiring pattern to be formed on the blackened layer. , the metal layer and the blackened layer can be made into a desired pattern.

In addition, when the metal layer and the blackened layer are etched, not only the thickness direction of the metal layer is etched, but also the side etching is also performed in the surface direction. Therefore, in order to obtain the desired shape of the wiring formed by patterning the metal layer, it is also necessary to consider the amount of undercut in advance, so that the pattern of the resist needs to be corrected to be smaller than the pattern derived from the desired wiring pattern. thick. However, correction to thicken the pattern of the resist based on the undercut amount hinders the miniaturization of the wiring pattern.

Therefore, the inventors of the present invention have studied and found that, by making the blackened layer the surface of the blackened layer, that is, the surface on the opposite side of the surface opposite to the transparent substrate, the roughened surface can be used. The occurrence of side erosion is suppressed. The reason for this is considered to be as follows, that is, by making the surface of the blackened layer roughened, when the resist is arranged, the adhesion between the blackened layer and the resist can be improved, and when etching is performed, the entry of the etching solution can be prevented. between the blackened layer and the resist.

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

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

The reason for this is that when the blackened layer contains granular crystals and the average crystal grain size is 50 nm or more, the adhesion between the blackened layer and the resist can be improved when the surface of the blackened layer is used as a roughened surface, In particular, the occurrence of undercuts can be suppressed. In addition, by including granular crystals in the blackened layer and making the average crystal grain size 150 nm or less, the blackened layer can be particularly suitable for suppressing the reflection of light on the surface of the metal layer. s color. When the blackened layer contains granular crystals, the average crystal grain size is preferably 70 nm or more and 150 nm or less.

In addition, when the blackened 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. The reason for this is that when the standard deviation σ is set to 10 nm or more, the granular crystals contained in the blackened layer have a certain degree of inhomogeneity, and in particular, the adhesion between the blackened layer and the resist can be improved. sex. 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.

It should be noted that the grain size of the granular crystals means that when the roughened surface of the blackened layer is observed with a scanning electron microscope or the like as described later, it completely includes (subsume) all The diameter of the circle of the smallest size of the granular crystals that were measured.

Further, when the blackened layer contains needle-like crystals, the blackened layer preferably contains 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 (aspect ratio) of 2.0 or more and 4.5. The following needle crystals.

The reason for this is that when the blackened layer contains needle-like crystals, and has an average length of 100 nm or more, an average width of 30 nm or more, and an aspect ratio of 2.0 or more, the surface of the blackened layer can be improved when the surface is roughened. The adhesion between the blackened layer and the resist can suppress the occurrence of side etching in particular. Furthermore, by making the blackened layer contain needle-like crystals, and having an average length of 300 nm or less, an average width of 80 nm or less, and an average aspect ratio of 4.5 or less, the blackened layer can be made particularly suitable for The color that suppresses the reflection of light on the surface of the metal layer.

When the blackened layer contains needle-like crystals, the average length is preferably 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.

In addition, when the blackened 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. The reason for this is that by setting the standard deviation σ of the length, width, and aspect ratio of the needle-like crystals in the above-mentioned ranges, the needle-like crystals contained in the blackened layer have unevenness to a certain degree or more. , in particular, the adhesion between the blackened layer and the resist can be improved. The upper limit of the standard deviation σ of the length, width, and aspect ratio of the needle-like crystals is not particularly limited, but may be, for example, 100 nm or less, 50 nm or less, and 5 or less, respectively.

It should be noted that the length and width of the needle-shaped crystals respectively mean the lengths of the long sides of the needle-shaped crystals when the roughened surface of the blackened layer is observed with a scanning electron microscope or the like as described later. and the length of the short side. Also, the aspect ratio is the length divided by the width.

The average grain size, average length, average width, average aspect ratio, and standard deviation σ of the crystals contained in the blackened layer can be measured by, for example, a scanning electron microscope (SEM: Scanning Electron Microscope). The observation image when the roughened surface of the layer was observed was measured and calculated.

The specific conditions for observing the roughened surface of the blackened layer are not particularly limited, but for example, it is preferable to magnify 50,000 times at an arbitrary position. In addition, when the blackened layer contains granular crystals, the grain size of 20 granular crystals arbitrarily selected in one field of view (field of view) can be measured, and the 20 granular crystals can be measured. The average value of the grain size of the granular crystals was taken as the average grain size. In addition, the standard deviation of the crystal grain size can also be calculated from the measured value of the crystal grain size of 20 granular crystals and the calculated average crystal grain size.

When the blackened layer contains needle-like crystals, the length and width of 20 needle-like crystals arbitrarily selected in one field of view can be measured similarly, and the aspect ratio can be calculated. In addition, the average value of the length, width, and aspect ratio of 20 needle-shaped crystals can be used as the average length, average width, and average aspect ratio. In addition, the respective standard deviations can be calculated from the measured values of the length and width of the 20 needle-like crystals, the calculated value of the aspect ratio, and the calculated average length, average width, and average aspect ratio.

It should be noted that, for granular crystals or needle-like crystals, it is preferable to select the position of the observation field so that 20 or more are included in one field of view. However, when such (20) fields of view cannot be selected In the case of , the average crystal grain size, average length, average width, and average aspect ratio may be calculated using less than 20 granular crystals or needle-like crystals.

As described above, the size of crystals such as granular crystals can be calculated with a scanning electron microscope or the like for the roughened surface of the blackened layer. Therefore, it can also be said that the granular crystals and/or needle-like crystals are blackened. Crystals contained in the roughened surface of the layer.

The method for forming the blackened layer is not particularly limited, and any method can be selected as long as it can form a rough plating layer containing each of the components described above. However, the wet method is preferably used from the viewpoint that the composition of the blackened layer can be controlled relatively easily so as to contain the above-mentioned components.

As the wet method, the electrolytic plating method is particularly preferably used.

The blackening plating solution used when the blackening layer is formed by electrolytic plating is not particularly limited as long as the blackening layer having the above-mentioned composition can be formed by preparing a film. . For example, a blackening 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 can be arbitrarily selected according to the degree of suppression of light reflection on the surface of the metal layer required for the blackening layer to be formed into a film.

For example, the nickel ion concentration in the blackening bath is preferably 2.0 g/L or more, more preferably 3.0 g/L or more. The reason for this is that when the concentration of nickel ions in the blackening plating solution is 2.0 g/L or more, the blackened layer can be made into a color particularly suitable for suppressing the reflection of light on the surface of the metal layer, and the conductive substrate can be formed. reflectivity is suppressed.

The upper limit of the nickel ion concentration in the blackening plating solution is not particularly limited, but, for example, it is preferably 20.0 g/L or less, more preferably 15.0 g/L or less. The reason for this is that when the nickel ion concentration in the blackening plating solution is 20.0 g/L or less, the excess of the nickel component in the formed blackening layer can be suppressed, and the surface of the blackening layer can be prevented from becoming glossy plating. A surface such as nickel can thereby suppress the reflectivity of the conductive substrate.

In addition, the copper ion concentration in the blackening plating solution is preferably 0.005 g/L or more, more preferably 0.008 g/L or more. This is because, when the copper ion concentration in the blackening plating solution is 0.005 g/L or more, the blackened layer can be made into a color particularly suitable for suppressing the reflection of light on the surface of the metal layer, and the blackening can be improved. According to the reactivity of the blackened layer with respect to the etching solution, even when the blackened 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 blackening plating solution is not particularly limited, but, for example, it is preferably 4.0 g/L or less, more preferably 1.02 g/L or less. The reason for this is that when the copper ion concentration in the blackening plating solution is 4.0 g/L or less, the reactivity of the formed blackening layer to the etching solution can be suppressed from being too high, and the blackening layer can be particularly The color suitable for suppressing the reflection of light on the surface of the metal layer can suppress the reflectivity of the conductive substrate.

When preparing a blackening plating solution, the method for supplying nickel ions and copper ions is not particularly limited, but may be supplied in a salt state, for example. For example, sulfamic acid salts and/or sulfates can preferably be used. It should be noted that, regarding the type of salt, each metal element may be the same type of salt, or different types of salt may be used simultaneously. Specifically, for example, a blackening plating solution can be prepared using the same type of salt as nickel sulfate and copper sulfate. In addition, for example, different kinds of salts such as nickel sulfate and copper sulfamate can be used together to prepare a blackening plating solution.

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

As the pH adjuster, that is, the alkali metal hydroxide, for example, at least one selected from sodium hydroxide, potassium hydroxide, and lithium hydroxide can be used. In particular, as the pH adjuster, that is, the alkali metal hydroxide, at least one selected from sodium hydroxide and potassium hydroxide is preferred. The reason for this is that sodium hydroxide and potassium hydroxide are readily available and cost is low.

Although the pH value of the blackening plating solution of this embodiment is not specifically limited, For example, it is preferable that it is 4.0 or more and 5.2, and it is more preferable that it is 4.5 or more and 5.0 or less.

The reason for this is that by setting the pH of the blackening plating solution to be 4.0 or more, when the blackening layer is formed using the blackening plating solution, the occurrence of color unevenness (color irregularity) in the blackening layer can be more reliably prevented. A blackened layer having a color that can suppress reflection of light in particular can be formed. Furthermore, by making the pH value of the blackening plating solution 5.2 or less, precipitation of a part of the components of the blackening plating solution can be suppressed.

In addition, the blackening plating solution may also contain a complexing agent. As the complexing agent, for example, amide sulfuric acid can be preferably used. By containing amide sulfuric acid in the blackening plating solution, a blackened layer of a color particularly suitable for suppressing the reflection of light on the surface of the metal layer can be formed.

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, and the like.

For example, when amide sulfuric acid is used as the complexing agent, the concentration of amide sulfuric acid in the blackening plating solution is not particularly limited, but is preferably 1 g/L or more and 50 g/L or less, preferably 5 g, for example. /L or more and 20 g/L or less. The reason for this is that by setting the concentration of amide sulfuric acid to be 1 g/L or more, the blackened layer can be made into 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 improved. inhibition. Further, even if amide sulfuric acid is added too much, the effect of suppressing the reflectance of the conductive substrate is not high, so it is preferably 50 g/L or less as described above.

It should be noted that the shape and/or size of crystals contained in the blackened layer can be selected by adjusting the pH value and/or the current density of the plating solution at the time of forming the blackened layer. For example, by increasing the pH value of the plating solution or increasing the current density during film formation, needle-like crystals can be easily formed, and by reducing the pH value of the plating solution or lowering the current density during film formation, granular crystals can be easily formed. .

For this purpose, conditions can be selected so as to obtain a blackened layer including crystals of a desired shape and size by, for example, preliminary experiments.

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

The thickness of the blackened layer is, for example, preferably 50 nm or more, more preferably 70 nm or more. Although the blackened layer has a function of suppressing the reflection of light by the metal layer, when the thickness of the blackened layer is thin, the reflection of light by the metal layer may not be sufficiently suppressed. On the other hand, by setting the thickness of the blackened layer to be 50 nm or more, the reflection on the surface of the metal layer can be suppressed more reliably, which is preferable.

In addition, the upper limit of the thickness of the blackening layer is not particularly limited, but if the thickness is too thick, the time required for etching at the time of wiring formation becomes long, which leads to an increase in cost. For this reason, the thickness of the blackened layer is preferably 350 nm or less, preferably 200 nm or less, and more preferably 150 nm or less.

In addition, arbitrary layers other than the above-mentioned transparent base material, metal layer, and blackening layer may be provided on the conductive substrate. For example, an adhesive layer may be provided.

A configuration example of the adhesion layer will be described.

The metal layer can be formed on the transparent substrate as described above, but when the metal layer is directly formed on the transparent substrate, the adhesiveness between the transparent substrate and the metal layer may be insufficient. For this reason, when the metal layer is directly formed on the upper surface of the transparent base material, the metal layer may peel off from the transparent base material during production or use.

Therefore, in the conductive substrate of the present embodiment, in order to improve the adhesiveness between the transparent substrate and the metal layer, an adhesive layer may be arranged on the transparent substrate. That is, it may be an electroconductive board|substrate which has an adhesive layer between a transparent base material and a metal layer.

By arranging the adhesive layer between the transparent base material and the metal layer, the adhesiveness between the transparent base material and the metal layer can be improved, and thereby the peeling of the metal layer from the transparent base material can be more reliably prevented.

In addition, the adhesion layer can also function as a blackening layer. For this reason, light reflection by the metal layer of light from the lower surface side of the metal layer, that is, the transparent substrate side, can also be suppressed.

The material constituting the adhesive layer is not particularly limited, and may be determined according to the adhesive force with the transparent substrate and the metal layer, the desired degree of suppression of light reflection on the surface of the metal layer, and the use environment (for example, humidity and/or humidity) of the conductive substrate. or temperature), the degree of stability, etc. can be arbitrarily selected.

The adhesion layer preferably contains at least one metal selected from Ni, Zn, Mo, Ta, Ti, V, Cr, Fe, Co, W, Cu, Sn, and Mn, for example. In addition, the adhesive layer may contain at least one element selected from carbon, oxygen, hydrogen, and nitrogen.

In addition, the adhesive layer may further contain a metal alloy containing at least two or more kinds of metals selected from Ni, Zn, Mo, Ta, Ti, V, Cr, Fe, Co, W, Cu, Sn, and Mn . In this case, the adhesive layer may further contain at least one element selected from carbon, oxygen, hydrogen, and nitrogen. In this case, as a metal alloy containing at least two kinds of metals selected from Ni, Zn, Mo, Ta, Ti, V, Cr, Fe, Co, W, Cu, Sn, and Mn, Cu- Ti-Fe alloy, Cu-Ni-Fe alloy, Ni-Cu alloy, Ni-Zn alloy, Ni-Ti alloy, Ni-W alloy, Ni-Cr alloy, or Ni-Cu-Cr alloy.

The film formation method of the adhesive layer is not particularly limited, but it is preferably formed by a dry plating method. As the dry plating method, for example, a sputtering method, an ion plating method, a vapor deposition method, or the like can be preferably used. When forming a film by a dry method for the adhesion layer, the sputtering method is preferably used from the viewpoint of easy control of the film thickness. In addition, one or more elements selected from carbon, oxygen, hydrogen, and nitrogen may be added to the adhesive layer as described above, and in this case, the reactive sputtering method is more preferably used.

When the adhesive layer contains one or more elements selected from carbon, oxygen, hydrogen, and nitrogen, the elements selected from carbon, oxygen, hydrogen, and nitrogen are added in advance in the environment at the time of film formation of the adhesive layer. The gas of one or more elements can be added to the adhesion layer. For example, in the case of adding carbon to the adhesion layer, one or more types selected from carbon monoxide gas and carbon dioxide gas may be added in advance to the atmosphere during dry plating, and in the case of adding oxygen, oxygen may be added in advance to In the environment during dry plating, in the case of adding hydrogen, one or more selected from hydrogen and water may be added in advance to the environment during dry plating, and in the case of adding nitrogen, nitrogen may be added in advance to the atmosphere during dry plating. environment during dry plating.

The gas containing one or more elements selected from carbon, oxygen, hydrogen, and nitrogen is preferably added to an inert gas as an environment during dry plating. Although it does not specifically limit as an inert gas, For example, it is preferable to use argon gas.

The adhesiveness between the transparent base material and the adhesive layer can be improved by forming a film by the above-mentioned dry plating method on the adhesive layer. Moreover, since an adhesive layer can contain a metal as a main component, for example, the adhesiveness with a metal layer is also high. Therefore, peeling of the metal layer can be suppressed by disposing the adhesive layer between the transparent base material and the metal layer.

The thickness of the adhesion layer is not particularly limited, but is preferably, for example, 3 nm or more and 50 nm or less, preferably 3 nm or more and 35 nm or less, and more preferably 3 nm or more and 33 nm or less.

When the adhesive layer is made to function also as a blackening layer, that is, when the reflection of light by the metal layer is suppressed, the thickness of the adhesive layer is preferably 3 nm or more as described above.

The upper limit of the thickness of the adhesive layer is not particularly limited, but if it is too thick, the time required for film formation and/or the time required for etching at the time of wiring formation becomes long, which leads to an increase in cost. Therefore, the thickness of the adhesive layer is preferably 50 nm or less as described above, preferably 35 nm or less, and more preferably 33 nm or less.

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

As described above, the conductive substrate of this embodiment may have a transparent base material, a metal layer, and a blackened layer. In addition, layers such as an adhesive layer may be arbitrarily provided.

A specific configuration example will be described below with reference to FIGS. 1A and 1B . FIGS. 1A and 1B show an example of a cross-sectional view of a surface of the conductive substrate of the present embodiment, which is parallel to the lamination direction of the transparent base material, the metal layer, and the blackened layer.

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

Specifically, for example, in the conductive substrate 10A shown in FIG. 1A , the metal layer 12 and the blackened layer 13 may be sequentially laminated on one surface 11 a side of the transparent substrate 11 . In the blackened layer 13 , the surface on the opposite side of the surface of the blackened layer 13 facing the transparent substrate 11 , that is, the surface A can be a roughened surface. In addition, in the conductive substrate 10B shown in FIG. 1B , the metal layers 12A, 12B, the blackened layer 13A, the blackened layer 13A, Each of 13B is a one-layer buildup. In this case, the surfaces of the blackened layers 13A and 13B on the opposite side to the surface facing the transparent substrate 11 , that is, the surface A and the surface B may be roughened surfaces.

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

Specifically, for example, as shown in the conductive substrate 20A shown in FIG. 2A , the adhesive layer 14, the metal layer 12, and the blackened layer 13 can be laminated in this order on the one surface 11a side of the transparent substrate 11.

In this case, the adhesive layer, the metal layer, and the blackening layer may be laminated on both surfaces of the transparent substrate 11 . Specifically, in the conductive substrate 20B shown in FIG. 2B , the adhesive layers 14A, 14B, the metal layers 12A, 12B, and the blackened layers can be sequentially formed on the one surface 11 a side and the other surface 11 b side of the transparent substrate 11 , respectively. The layers 13A and 13B are laminated.

1B and 2B show that when a metal layer, a blackened layer, etc. are laminated on both surfaces of a transparent base material, the transparent base material 11 is used as a symmetrical plane, and the transparent base material The layers stacked on the upper and lower sides of 11 are arranged symmetrically, but are not limited to this form. For example, in FIG. 2B , the configuration on the side of one surface 11 a of the transparent substrate 11 may be the same as the configuration in FIG. 1B , without providing the adhesion layer 14A, but in which the metal layer 12A and the blackened layer 13A are laminated in this order. In this way, the layers laminated on the upper and lower sides of the transparent substrate 11 can have an asymmetric structure.

In addition, in the conductive substrate of the present embodiment, by providing the metal layer and the blackened layer on the transparent base material, the reflection of light by the metal layer can be suppressed, thereby suppressing the reflectance of the conductive substrate. .

The degree of reflectance of the conductive substrate of the present embodiment is not particularly limited, but for example, in order to improve the visibility of a display when used as a conductive substrate for a touch panel, the reflectance is preferably low. 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, more preferably 10% or less.

The reflectance can be measured by irradiating light to the blackened layer of the conductive substrate. Specifically, for example, as shown in FIG. 1A , when the metal layer 12 and the blackened layer 13 are laminated in this order on the one surface 11 a side of the transparent substrate 11 , the surface A of the blackened layer 13 is irradiated with light. The measurement can be performed by irradiating light to the blackened layer 13 . During the measurement, light having a wavelength of 400 nm or more and 700 nm or less can be irradiated to the blackened layer 13 of the conductive substrate as described above at intervals of, for example, a wavelength of 1 nm, and the average value of the measured values can be used as the conductive substrate. reflectivity.

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 have a structure including mesh wiring.

The conductive substrate provided with the mesh wiring can be obtained by etching the metal layer, the blackened layer, and sometimes the adhesion layer of the conductive substrate of the present embodiment described so far.

For example, two layers of wiring may be used to form mesh wiring. A specific configuration example is shown in FIG. 3 . FIG. 3 shows a view of the conductive substrate 30 provided with the mesh wiring when viewed from the upper surface side in the lamination direction of the metal layers and the like. In order to facilitate understanding of the wiring pattern, the transparent substrate and the metal layer are patterned by The illustration of the layers other than the wirings 31A and 31B formed by forming them is omitted. In addition, the wiring 31B visible through the transparent base material 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. In addition, the wiring 31A, 31B is formed by etching a metal layer, and the blackening layer which is not shown in figure is formed in the upper surface or the lower surface of this wiring 31A, 31B. In addition, the blackened layer is etched into the same shape as the wirings 31A and 31B.

The arrangement of the transparent base material 11 and the wirings 31A and 31B is not particularly limited. A configuration example of the arrangement of the transparent base material 11 and the wiring is shown in FIGS. 4A and 4B . 4A and 4B are cross-sectional views taken along the line A-A' in FIG. 3 .

First, as shown in FIG. 4A , wirings 31A and 31B may be arranged on the upper and lower surfaces of the transparent substrate 11 , respectively. Note that, in FIG. 4A , blackened layers 32A and 32B etched into the same shape as the wiring are further arranged on the upper surface of the wiring 31A and the lower surface of the wiring 31B.

Alternatively, as shown in FIG. 4B , one set of transparent substrates 11 may be used, wirings 31A and 31B may be arranged on the upper and lower surfaces of one transparent substrate 11 sandwiched therebetween, and wiring 31B may be arranged between the transparent substrates 11 . In this case, blackened layers 32A and 32B etched into the same shape as the wirings may be arranged on the upper surfaces of the wirings 31A and 31B. In addition, as mentioned above, you may provide an adhesive layer in addition to a copper layer and a blackening layer. For this reason, in both the case of FIG. 4A and FIG. 4B , for example, an adhesive layer may be provided between the wiring 31A and/or the wiring 31B and the transparent base material 11 . When an adhesive layer is provided, it is also preferable that the adhesive layer is etched into the same shape as the wirings 31A and 31B.

For example, as shown in FIG. 1B , the conductive substrate having the mesh wiring shown in FIGS. 3 and 4A can utilize the conductive substrate having copper layers 12A and 12B and blackened layers 13A and 13B on both surfaces of the transparent substrate 11 . formed on the substrate.

The case of forming using the conductive substrate of FIG. 1B will be described as an example. First, the metal layer 12A and the blackened layer 13A on the one surface 11a side of the transparent base material 11 are etched so as to match the Y-axis direction in FIG. 1B . A plurality of parallel linear patterns are arranged at predetermined intervals along the X-axis direction. In addition, the X-axis direction in FIG. 1B means the direction parallel to the width direction of each layer. In addition, the Y-axis direction in FIG. 1B means the direction perpendicular|vertical to the paper surface in FIG. 1B.

Next, the metal layer 12B and the blackening layer 13B on the other surface 11b side of the transparent base material 11 are etched so that a plurality of linear patterns parallel to the X-axis direction in FIG. 1B are spaced apart along the Y-axis direction at a specific interval And configure.

Through the above operations, the conductive substrate having the mesh wiring shown in FIGS. 3 and 4A can be formed. In addition, you may etch both surfaces of the transparent base material 11 at the same time. That is, the copper layers 12A, 12B and the blackened layers 13A, 13B may be etched at the same time. In addition, the conductive substrate shown in FIG. 4A further having an adhesive layer patterned in the same shape as the wirings 31A and 31B between the wirings 31A and 31B and the transparent base material 11 can be used as shown in FIG. 2B . The conductive substrate is also produced by the same etching.

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 FIG. 2A . A case of forming using two conductive substrates shown in FIG. 1A will be described as an example, and the metal layer 12 and the blackened layer 13 of the two conductive substrates shown in FIG. A plurality of linear patterns whose directions are parallel are arranged along the Y-axis direction at predetermined intervals. Then, by bonding the two conductive substrates so that the directions of the linear patterns formed on the respective conductive substrates by the above-described etching process intersect with each other, a conductive substrate provided with mesh wiring can be formed. When bonding two conductive substrates, the bonding surface is not particularly limited. For example, the surface A in FIG. 1A on which the metal layer 12 and the like are laminated may be bonded to the other surface 11b in FIG. 1A on which the copper layer 12 and the like are not laminated, thereby obtaining as shown in FIG. 4B . Structure.

In addition, for example, the other surfaces 11b of the transparent base material 11 in FIG. 1A on which the metal layer 12 and the like are not laminated may be bonded to each other to have a structure as shown in cross section in FIG. 4A .

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

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

However, according to the conductive substrate of the present embodiment, it can be seen that it has a blackened layer containing elemental nickel, nickel oxide, nickel hydroxide, and copper, and even if the blackened layer and the metal layer are simultaneously etched for patterning In the case of blackening, the blackening layer and the metal layer can also be patterned into a desired shape. In addition, the occurrence of undercuts can be suppressed. Specifically, for example, a wiring having a wiring width of 10 μm or less can be formed. For this reason, the conductive substrate of the present embodiment preferably includes wirings 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.

3 , 4A, and 4B illustrate an example in which a linear-shaped wiring is used in combination to form a meshed wiring (wiring pattern), but it is not limited to this form, and the wiring constituting the wiring pattern may be for any shape. For example, in order not to generate moiré with the image of the display, the shapes of the wirings constituting the mesh wiring pattern may be designed in various shapes such as zigzag lines (zigzag straight lines), etc. .

It is preferable that a conductive substrate having such a mesh wiring composed of two layers of wiring can be used as a conductive substrate for a touch panel of a projection type electrostatic capacitance system, for example.

As can be seen from the above-described conductive substrate of the present embodiment, the metal layer formed on at least one surface of the transparent base material has a structure in which the blackened layer is laminated. In addition, since the blackened layer contains elemental nickel, nickel oxide, nickel hydroxide, and copper, when patterning the metal layer and the blackened layer by etching, the blackened layer can be easily patterned as desired shape.

In addition, the blackened layer is a roughened plating layer in which the surface on the opposite side of the surface facing the transparent base material is a roughened surface. Therefore, the adhesiveness with the resist is high, and the occurrence of side etching can be suppressed.

In addition, in the conductive substrate of the present embodiment, the blackened layer contained therein can sufficiently suppress the reflection of light on the surface of the metal layer, so that it can be a conductive substrate capable of suppressing reflectance. In addition, when applied to applications such as touch panels, for example, the visibility of the display can be improved.

(Manufacturing method of conductive substrate)

Next, a configuration example of the method of manufacturing the conductive substrate of the present embodiment will be described.

The manufacturing method of the electroconductive board|substrate of this embodiment may have the following steps.

A metal layer forming step of 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.

Further, in the blackening layer forming step, a blackening layer containing elemental nickel, nickel oxide, nickel hydroxide, and copper may be formed.

Hereinafter, the manufacturing method of the electroconductive board|substrate of this embodiment is demonstrated concretely.

In addition, it is preferable to manufacture the said electroconductive board|substrate by the manufacturing method of the electroconductive board|substrate of this embodiment. For this reason, the parts other than the parts to be described below can have the same configuration as in the case of the above-described conductive substrate, and therefore a part of the description is omitted.

The transparent substrate used in the metal layer forming step may be prepared in advance. The type of the transparent base material to be used is not particularly limited, however, as described above, a transparent base material such as an insulator film (resin film) that transmits visible light, a glass substrate, and the like can be preferably used. In addition, if necessary, the transparent base material may be cut into any size or the like in advance.

In addition, the metal layer preferably has a copper thin film layer as described above. In addition, the metal layer may also have a metal thin film layer and a metal plating layer. To this end, the metal layer forming step may have, for example, a step of forming a metal thin film layer using a dry plating method. In addition, the metal layer forming step may include 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 type of wet plating method using the metal thin film layer as a power supply layer.

It does not specifically limit as a dry plating method used in the process of forming a metal thin film layer, For example, a vapor deposition method, a sputtering method, an ion plating method, etc. can be used. In addition, as a vapor deposition method, a vacuum vapor deposition method can be used preferably. As the dry plating method used in the step of forming the metal thin film layer, the sputtering method is preferably used because it is particularly easy to control the film thickness.

Next, the step of forming the 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 in conventional methods can be employed. For example, the metal plating layer can be formed by supplying the base material on which the metal thin film layer is formed into a plating tank having a metal plating solution, and controlling the current density and/or the conveyance speed of the base material.

Next, the blackened layer forming step will be described.

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

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

The blackened layer is preferably a roughened plating layer in which the surface on the opposite side of the surface opposed to the transparent substrate is a roughened surface as described above. In addition, the shape and/or size of the crystals contained in the blackened layer can also be selected by adjusting the pH value and/or the current density of the blackening plating solution when the blackening layer is formed. For example, by increasing the pH value of the plating solution or increasing the current density during film formation, needle-like crystals can be easily formed, and by decreasing the pH value of the plating solution or lowering the current density during film formation, granular crystals can be easily formed. crystallization.

For this purpose, conditions can be selected so as to obtain a blackened layer including crystals of a desired shape and size by, for example, preliminary experiments.

Since the blackening plating solution has already been described, the description thereof is omitted.

In the manufacturing method of the electroconductive board|substrate of this embodiment, you may implement arbitrary steps other than the above-mentioned steps.

For example, in the case of forming an adhesive layer between a transparent substrate and a metal layer, an adhesive layer forming step of forming an adhesive layer on the surface of the transparent substrate on which the metal layer is to be formed may be performed. In the case of performing the step of forming an adhesive layer, the step of forming a metal layer may be performed after the step of forming an adhesive layer, and in this case, in the step of forming a metal layer, the transparent substrate may be formed on the substrate on which the adhesive layer is formed in this step. A metal thin film layer is formed.

In the adhesion layer forming step, the film forming method of the adhesion layer is not particularly limited, however, it is preferable to form the film by a dry plating method. As the dry plating method, for example, a sputtering method, an ion plating method, a vapor deposition method, or the like can be preferably used. When forming a film by a dry method for the adhesion layer, the sputtering method is preferably used from the viewpoint of easy control of the film thickness. In addition, one or more elements selected from carbon, oxygen, hydrogen, and nitrogen may be added to the adhesive layer as described above, and in this case, the reactive sputtering method can be more preferably used.

The conductive substrate obtained by the method for producing a conductive substrate of the present embodiment can be used for various applications such as a touch panel, for example. In addition, when used in various applications, the metal layer and the blackened layer included in the conductive substrate of the present embodiment are preferably patterned. In addition, when providing an adhesive layer, it is preferable that an adhesive layer is also patterned. The metal layer, the blackened layer, and, if necessary, the adhesion layer, for example, can be patterned according to a desired wiring pattern, and the metal layer, the blackened layer, and the adhesion layer, if necessary, are preferably patterned as follows. same shape.

For this reason, the manufacturing method of the conductive substrate of the present embodiment may include a patterning step of patterning the metal layer and the blackened layer. In addition, when an adhesive layer is formed, the patterning step may be a step of patterning the adhesive layer, the metal layer, and the blackened layer.

The specific steps of the patterning step are not particularly limited, and any steps can be employed. For example, in the case of the conductive substrate 10A in which the metal layer 12 and the blackened layer 13 are laminated on the transparent base material 11 as shown in FIG. 1A , first, the surface A of the blackened layer 13 may be arranged with a desired The resist configuration step of the patterned resist. Then, an etching step of supplying an etchant to the surface A of the blackened layer 13, that is, to the surface side where the resist is arranged, can be performed.

The etching solution used in the etching step is not particularly limited. However, the blackening layer formed by the manufacturing method of the electroconductive board|substrate of this embodiment has the reactivity with respect to an etching liquid substantially the same as that of a metal layer. For this reason, the etching solution used in the etching step is not particularly limited, and an etching solution used for general metal layer etching can be preferably used.

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

The etching solution can be used at room temperature, however, in order to increase the reactivity, it may be heated, for example, it may be heated to 40° C. or higher and 50° C. or lower before use.

In addition, as shown in FIG. 1B, the conductive substrate 10B in which the metal layers 12A and 12B and the blackened layers 13A and 13B are laminated on the one surface 11a and the other surface 11b of the transparent substrate 11 can also be applied. A patterning step in which patterning is performed. In this case, for example, first, a resist arrangement step of disposing a resist having a desired pattern on the surfaces A and B of the blackened layers 13A and 13B may be performed. Then, an etching step of supplying an etchant to the surfaces A and B of the blackened layers 13A and 13B, that is, to the surface side where the resist is arranged, can be performed.

The pattern formed in the etching step is not particularly limited, and any shape may be used. For example, in the case of the conductive substrate 10A shown in FIG. 1A , the metal layer 12 and the blackened layer 13 can be formed to include a plurality of straight lines and/or zigzag lines (“zigzag straight lines”) as described above. picture of.

In addition, in the case of the conductive substrate 10B shown in FIG. 1B , a pattern such as mesh wiring may be formed on the metal layer 12A and the metal layer 12B. In this case, the blackened layer 13A is preferably patterned in the same shape as the metal layer 12A, and the blackened layer 13B is preferably patterned in the same shape as the metal layer 12B.

Moreover, after patterning the metal layer 12 etc. of the above-mentioned electroconductive board|substrate 10A in a patterning process, for example, the lamination process of laminating|stacking two or more patterned electroconductive board|substrates may be performed. In the case of lamination, for example, the patterns of the metal layers of the respective conductive substrates can be laminated so as to intersect each other, whereby a laminated conductive substrate provided with mesh wiring can be obtained.

The method of fixing the laminated two or more conductive substrates is not particularly limited, however, for example, it can be fixed by an adhesive or the like.

The conductive substrate obtained by the above-described method for producing a conductive substrate of the present embodiment has a structure in which a blackened layer is laminated on the metal layer formed on at least one surface of the transparent substrate. In addition, since the blackened layer contains elemental nickel, nickel oxide, nickel hydroxide, and copper, when the metal layer and the blackened layer are patterned by etching as described above, the blackened layer can be easily patterned to the desired shape.

In addition, the blackened layer is a roughened plating layer in which the surface on the opposite side of the surface facing the transparent base material is a roughened surface. Therefore, the adhesiveness with the resist is high, and the occurrence of side etching can be suppressed.

In addition, in the conductive substrate obtained by the method for producing a conductive substrate of the present embodiment, the blackened layer included in the conductive substrate can sufficiently suppress the reflection of light on the surface of the metal layer, so that the reflectance can be suppressed. conductive substrate. Therefore, when used for applications such as touch panels, the visibility of the display can be improved.

[Example]

Specific examples and comparative examples are given and described below, 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) Composition analysis of blackened layer

The component analysis of the blackened layer was performed using an X-ray photoelectron spectrometer (manufactured by "PHI Corporation", model: QuantaSXM). In addition, monochromatic Al (1486.6eV) was used as an X-ray source.

As will be described later, in each of the following experimental examples, a conductive substrate having the structure shown in FIG. 1A was produced. Therefore, Ar ion etching was performed on the exposed surface A of the blackened layer 13 in FIG. 1A , and the Ni 2P spectrum and the Cu LMM spectrum were measured from the outermost surface to a depth of 10 nm. From the obtained spectrum, the ratio of the atomic number of copper when the atomic number of nickel contained in the blackened layer was set to 100 was calculated. In addition, in Table 1, the result was shown as the ratio of a metal component.

In addition, by peak separation analysis of the Ni 2P spectrum, the atomic number of nickel, which has become nickel oxide, and the number of nickel hydroxide, which are contained in the blackened layer, when the atomic number of metallic nickel is set to 100, was calculated. atomic number of nickel. In addition, in Table 1, the result was shown as the ratio of a nickel component.

(2) Measurement of reflectance

The measurement was performed by installing a reflectance measuring unit on an ultraviolet-visible spectrophotometer (manufactured by "Shimadzu Corporation", model: UV-2600).

As will be described later, in each experimental example, a conductive substrate having the structure shown in Fig. 1A was produced. Therefore, in the reflectance measurement, under the conditions of an incident angle of 5° and a light-receiving angle of 5°, the surface of the blackened layer 13 of the conductive substrate 10A shown in FIG. A is irradiated with light having a wavelength of 400 nm or more and 700 nm or less, and the regular reflectance is measured, and the average value thereof is used 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 laminating. Then, UV exposure was performed through a photo mask, and the resist was dissolved in a 1% sodium carbonate aqueous solution for development. According to this, samples having patterns in which the width of the resist differs every 0.5 μm in the range of 3.0 μm or more and 10.0 μm or less were produced. That is, 15 kinds of linear patterns with different resist widths at every 0.5 μm of 3.0 μm, 3.5 μm, 4.0 μm, . . . , 9.5 μm, and 10.0 μm were formed.

Next, the sample was immersed in an etching solution at 30° C. containing 10% by weight of sulfuric acid and 3% by weight of hydrogen peroxide, and after 40 seconds, the dry film resist was peeled off and removed using an aqueous sodium hydroxide solution.

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

After the resist is peeled off, if the minimum value of the wiring width of the metal wiring remaining on the conductive substrate is smaller, and the dissolved residual amount around the formed metal wiring is smaller, it means that the copper layer and blackening are The reactivity of the layers to the etchant is closer (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 residual amount of dissolution was observed around the formed metal wiring, it was evaluated as ◯. When the minimum value of the remaining metal wiring was 3 μm or more and 10 μm or less, but a part of the dissolved residual amount that did not affect the actual use was observed around the formed metal wiring, it was evaluated as Δ. In addition, when the metal wiring with a wiring width of 10 m or less was not able to be dissolved in the etching solution and could not be formed, it was evaluated as unacceptable, that is, x. In the case of (circle) or (triangle|delta), it can be said that it is an electroconductive board|substrate which has a metal layer and a blackening layer which can be etched at the same time, and can be evaluated as a pass.

In addition, Table 2 shows ○, △, and × as evaluation results.

(4) Shape and size of crystals contained in the blackened layer

The roughened surface of the blackened layer, that is, the surface on the opposite side of the surface facing the transparent substrate, specifically, the surface A in FIG. 1A, was observed with a scanning electron microscope, and the blackened layer was observed with a scanning electron microscope. The shape and size of the crystals contained in it were evaluated.

In the evaluation, the region was first magnified by a factor of 50,000 at an arbitrary position on the roughened surface of the blackened layer. Then, the shape of the crystals present in the observation area was observed. When granular crystals were observed, they were shown as granular in the column of crystal shape in Table 2, and when needle-shaped crystals were observed, they were shown as needles in the column of crystal shape in Table 2.

Next, when granular crystals were observed, 20 granular crystals to be evaluated were selected, and the average grain size and standard deviation σ were measured and calculated. In addition, the crystal grain size of a granular crystal means the diameter of a circle which completely includes the smallest size of the granular crystal for which the measurement of the granular crystal is performed.

In addition, 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 evaluating granular crystals, the average value and standard deviation of the grain size are described in the column of "grain size/length" in Table 2.

When evaluating needle-like crystals, the average value and standard deviation of the length are described in the column of "grain size/length" in Table 2, and the average value and standard deviation of the width and aspect ratio are respectively recorded. Described in the columns of "width" and "aspect ratio" in Table 2.

Each parameter has already been described, so its description is omitted here.

(5) Side erosion amount

First, a dry film resist (Hitachi Chemicals RY3310) was attached to the surface of the blackened layer of the conductive substrate obtained in the following experimental example by laminating. Then, UV exposure was performed through a photomask, and the resist was dissolved in a 1% aqueous sodium carbonate solution for development. Accordingly, a sample of a resist having a plurality of linear patterns parallel to each other on the blackened layer was produced.

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

With respect to the obtained sample, the cross section of the conductive substrate parallel to the lamination direction of each layer and perpendicular to the linear pattern of the resist was observed without peeling off the resist. In this case, as shown in FIG. 5 , it was observed that the patterned metal layer 52 , the patterned blackened layer 53 , and the resist 54 were laminated on the transparent substrate 51 . Moreover, the distance L between the edge part 54a of the width direction of a resist and the edge part 52a of the width direction of the patterned metal layer 52 was also measured as the undercut amount.

In addition, after 60 seconds, 120 seconds, and 180 seconds after the start of the immersion in the etching solution, the conductive substrate was taken out from the etching solution, and after cleaning, the side was carried out as described above. Erosion evaluation.

(Conditions for making samples)

A conductive substrate was produced under the conditions described below, and evaluated by the above-mentioned evaluation method. Experiment 1 to Experiment 10 are all examples.

[Experimental Example 1]

A conductive substrate having the structure shown in FIG. 1A was produced.

(Metal layer forming step)

The metal layer was formed into a film on one surface of a long transparent base material made of polyethylene terephthalate resin (PET) having a length of 300 m, a width of 250 mm, and a thickness of 100 μm. In addition, the total light transmittance of the transparent base material made of polyethylene terephthalate resin used as a transparent base material was evaluated by the method prescribed|regulated by JIS K 7361-1, and it was 97%.

In the metal layer forming step, a metal thin film layer forming step and a metal plating layer forming step are 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 a 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 heated to 60° C. in advance to remove moisture was set in the cavity of the sputtering apparatus.

Then, after evacuating the inside of the chamber to 1×10 ⁻³ Pa, argon gas was introduced to adjust the pressure inside the chamber to 1.3 Pa.

By supplying electric power to a copper target set in advance on the cathode of the sputtering apparatus, a copper thin film layer with a thickness of 0.7 μm was formed on one surface of the transparent substrate.

Next, the metal plating layer is formed in the metal plating layer forming step. The metal plating layer was formed by plating a metal plating layer with a thickness of 0.3 μm.

By carrying out the above-described 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 with the copper layer having a thickness of 1.0 μm formed on the transparent substrate produced in the metal layer forming step was immersed in 20 g/L sulfuric acid for 30 sec, and after washing, the following blackening layer forming step was performed.

(Blackening layer forming step)

In the blackening layer forming step, a blackening layer is formed on one surface of the copper layer by an electrolytic plating method using a blackening plating solution.

In addition, as a blackening plating liquid, the plating liquid containing nickel ion, copper ion, amide sulfuric acid, and sodium hydroxide was prepared. In the blackening plating solution, nickel ions and copper ions were supplied by adding nickel sulfate hexahydrate and copper sulfate pentahydrate.

Next, each component was added and prepared 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 amide sulfuric acid was 11 g/L.

In addition, an aqueous sodium hydroxide solution was also added to the blackening plating solution, and the pH of the blackening plating solution was adjusted to 4.9.

In the blackening layer forming step, the blackening layer was formed by electroplating 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 sec.

The film thickness of the formed blackened layer was 110 nm.

The component analysis of the blackened layer described above, and the evaluation of reflectance and etching characteristics were performed on the conductive substrate obtained by the above steps. The results are shown in Table 1 and Table 2.

[Experimental Example 2 to Experimental Example 10]

In each experimental example, except that the nickel ion concentration and copper ion concentration in the blackening plating solution when forming the blackening layer, the current density when the blackening layer is formed, and the plating time are as shown in Table 1 Except having changed this point, a conductive substrate was produced and evaluated in the same manner as in Experimental Example 1. The results are shown in Table 1 and Table 2.

From the results shown in Table 2, it was confirmed that in any of Experimental Examples 1 to 10, the blackened layer contained elemental nickel, nickel oxide, nickel hydroxide, and copper.

In addition, from the results shown in Table 1, even in terms of etching properties, the evaluation results were all ○ or Δ, that is, it was confirmed that it was a conductive substrate having a metal layer and a blackened layer that can be etched at the same time.

In particular, when the ratio of the atomic number of nickel and copper contained in the blackened layer was 100, it was confirmed that in the experimental examples 1 to 8 in which the copper content was 7 or more and 90 or less , the etching characteristics are ○, and the reflectivity is also 10% or less. Therefore, in the conductive substrates of Experimental Examples 1 to 8, it was confirmed that the reactivity of the metal layer and the blackened layer to the etching solution was very close, and the reflection of light on the surface of the metal layer was particularly suppressed. blackened layer.

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

The conductive substrate has been described above based on the embodiments, examples, and the like, but the present invention is not limited to the above-mentioned embodiments, examples, and the like. Various modifications and changes can be made within the scope of the gist of the present invention described in the claims.

This application claims priority based on Japanese Patent Application No. 2017-081591 filed with the Japan Patent Office on April 17, 2017, and the entire contents of Japanese Patent Application No. 2017-081591 are incorporated herein by reference.

10A, 10B‧‧‧Conductive substrate

11‧‧‧Transparent substrate

11a‧‧‧One surface

11b‧‧‧Another surface

12, 12A, 12B‧‧‧Metal layer

13, 13A, 13B‧‧‧Blackening layer

A, B‧‧‧surface

X, Y‧‧‧X axis, Y axis

Claims (6)

A conductive substrate comprising: a transparent base material; a metal layer formed on at least one surface of the transparent base material; and a blackened layer formed on the metal layer, the blackened layer containing elemental nickel and nickel oxide , nickel hydroxide, and roughened plating of copper, in terms of the ratio of the atomic number of nickel and copper contained in the blackened layer, when nickel is set to 100, copper is 5 or more and 90 or less . The conductive substrate according to claim 1, wherein an adhesive layer is provided between the transparent substrate and the metal layer. The conductive substrate according to claim 1 or 2, wherein the blackened layer includes granular crystals having an average grain size of 50 nm or more and 150 nm or less. The conductive substrate according to claim 1 or 2, wherein the blackened layer includes needles 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. crystals. The conductive substrate according to claim 1 or 2, wherein the thickness of the blackened layer is 50 nm or more and 350 nm or less. The conductive substrate according to claim 1 or 2, wherein the metal layer is a layer of copper or copper alloy.

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