WO2017130866A1

WO2017130866A1 - Blackening plating solution and method for manufacturing conductive substrate

Info

Publication number: WO2017130866A1
Application number: PCT/JP2017/001987
Authority: WO
Inventors: 下地　匠; 志賀　大樹
Original assignee: 住友金属鉱山株式会社
Priority date: 2016-01-29
Filing date: 2017-01-20
Publication date: 2017-08-03
Also published as: JPWO2017130866A1; KR102611763B1; KR20180103072A; TW201739966A; CN108603301A; TWI791427B; JP6806093B2

Abstract

Provided is a blackening plating solution containing nickel ions and copper ions, and having a pH value of 4.0-5.8, inclusive.

Description

Method for producing blackening plating solution, conductive substrate

The present invention relates to a method for producing a blackening plating solution and a conductive substrate.

The capacitive touch panel converts information on the position of the adjacent object on the panel surface into an electrical signal by detecting a change in capacitance caused by the object in proximity to the panel surface. Since the conductive substrate used in the capacitive touch panel is disposed on the surface of the display, the material of the conductive layer of the conductive substrate is required to have a low reflectance and be hard to be recognized.

Therefore, as a material of the conductive layer used in the capacitive touch panel, a material having a low reflectance and which is hard to be recognized is used, and a wiring is formed on a transparent substrate or a transparent film.

For example, Patent Document 1 discloses a transparent conductive film including a polymer film and a transparent conductive film comprising a metal oxide provided thereon by a vapor deposition method, as a transparent conductive film comprising a metal oxide The use of indium oxide-tin oxide (ITO) films is disclosed.

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

Therefore, using a metal such as copper instead of ITO as a material of the conductive layer has been studied. However, since metal has a metallic luster, there is a problem that the visibility of the display is reduced by reflection. For this reason, a conductive substrate subjected to a blackening treatment in which a layer made of a black material is formed by a dry method on the surface of the conductive layer has been studied.

However, it takes time to fully blacken the surface of the conductive layer by the dry method, and the productivity is low.

Therefore, the inventors of the present invention have examined the blackening treatment by the wet method because the equipment can be simplified and the productivity is excellent without requiring the vacuum environment required by the dry method. The Specifically, it has been studied to form a blackened layer by a wet method using a plating solution containing Ni and Zn as main components.

Japanese Patent Application Laid-Open No. 2003-151358

However, when performing a blackening treatment to form a blackened layer by a wet method, that is, a wet plating method using a plating solution containing Ni and Zn as main components, the blackened layer to be formed is formed as a conductive layer In some cases, the reactivity to the etching solution is higher than that of the copper layer. And when producing the conductive substrate which has a desired wiring pattern, after forming the copper layer which is a conductive layer, and a blackening layer, it will pattern by etching, but the copper layer to etching liquid, Due to the difference in reactivity with the blackened layer, it has been difficult in some cases to pattern the blackened layer into a desired shape.

In view of the problems of the prior art described above, an object of the present invention is to provide a blackening plating solution capable of forming a blackening layer which can be patterned into a desired shape when etched together with a copper layer. I assume.

In one aspect of the present invention to solve the above problems,
Containing nickel ions and copper ions,
Provided is a blackening plating solution having a pH of 4.0 or more and 5.8 or less.

According to one aspect of the present invention, it is possible to provide a blackening plating solution capable of forming a blackening layer that can be patterned into a desired shape when etched together with a copper layer.

BRIEF DESCRIPTION OF THE DRAWINGS Sectional drawing of the electroconductive substrate which concerns on embodiment of this invention. BRIEF DESCRIPTION OF THE DRAWINGS Sectional drawing of the electroconductive substrate which concerns on embodiment of this invention. BRIEF DESCRIPTION OF THE DRAWINGS Sectional drawing of the electroconductive substrate which concerns on embodiment of this invention. BRIEF DESCRIPTION OF THE DRAWINGS Sectional drawing of the electroconductive substrate which concerns on embodiment of this invention. The top view of the conductive substrate provided with the mesh-like wiring concerning the embodiment of the present invention. FIG. 4 is a cross-sectional view taken along line AA ′ of FIG. 3; FIG. 4 is a cross-sectional view taken along line AA ′ of FIG. 3;

Hereinafter, one embodiment of the blackening plating solution and the conductive substrate of the present invention will be described.
(Blackening plating solution)
The blackening plating solution of the present embodiment contains nickel ions and copper ions and can have a pH of 4.0 or more and 5.8 or less.

As described above, for example, a blackened layer formed by a wet method using a plating solution containing Ni and Zn as main components has higher reactivity to the etching solution than the copper layer and is etched together with the copper layer It was difficult to pattern it into the desired shape. Therefore, the inventors of the present invention conducted intensive studies on a blackening plating solution capable of forming a blackening layer which can be patterned into a desired shape when etched together with a copper layer.

And while proceeding with the study on the blackening plating solution, the inventors of the present invention suppress the reactivity of the blackening layer to the etching solution by using the blackening layer as a layer containing nickel and copper. It has been found that the desired shape can be obtained even when etching is performed simultaneously with the copper layer. In addition, it was also found that the blackening layer can be made to have a color that can suppress the reflection of light on the surface of the copper layer by containing nickel and copper. The desired shape in the case where the copper layer and the blackening layer are simultaneously etched means, for example, a shape or pattern including a wiring having a wiring width of 10 μm or less.

Therefore, the blackening plating solution of the present embodiment is preferably a plating solution capable of forming a layer containing nickel and copper as a metal component, and the blackening plating solution of the present embodiment includes nickel ions and copper ions. And can be contained.

The concentration of each component in the blackening plating solution is not particularly limited, but the nickel ion concentration in the blackening plating solution is preferably 2.0 g / l or more, and 3.0 g / l or more. It is more preferable that This is because the nickel ion concentration in the blackening plating solution is 2.0 g / l or more to make the blackening layer a color particularly suitable for suppressing the light reflection on the copper layer surface, and the conductive substrate It is because the reflectance of can be suppressed.

The upper limit value of the nickel ion concentration in the blackening plating solution is not particularly limited either, but is preferably 20.0 g / l or less, and more preferably 15.0 g / l or less. This controls the nickel ion concentration in the blackening plating solution to be 20.0 g / l or less, thereby suppressing the excess of the nickel component in the formed blackening layer, and the blackening layer surface has a bright nickel. It is because it can prevent that it becomes a surface like plating and can control the reflectance of a conductive board.

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 makes the blackening layer a color particularly suitable for suppressing light reflection on the copper layer surface when the copper ion concentration in the blackening plating solution is 0.005 g / l or more, and etching the blackening layer This is because the reactivity to the solution is made particularly appropriate, and even when the blackened layer is etched together with the copper layer, it can be patterned more reliably to the desired shape.

The upper limit value of the copper ion concentration in the blackening plating solution is not particularly limited, but is preferably 1.02 g / l or less, and more preferably 0.5 g / l or less. This controls the copper ion concentration in the blackening plating solution to be 1.02 g / l or less, thereby preventing the reactivity of the formed blackening layer with respect to the etching solution from becoming too high, thereby making the blackening layer copper. This is because the color is particularly suitable for suppressing the reflection of light on the layer surface, and the reflectance of the conductive substrate can be suppressed.

When preparing a blackening plating solution, the supply method of nickel ion and copper ion is not specifically limited, For example, it can supply in the state of a salt. For example, sulfamate and 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 simultaneously. Specifically, a blackening plating solution can also be prepared using, for example, the same type of salt as nickel sulfate and copper sulfate. Also, it is possible to prepare a blackening plating solution by simultaneously using different types of salts such as, for example, nickel sulfate and copper sulfamate.

The blackening plating solution of the present embodiment may further contain an amidosulfuric acid which functions as a complexing agent, in addition to the nickel ion and the copper ion. By containing amidosulfuric acid, it is possible to make a blackening layer of a color particularly suitable for suppressing the reflection of light on the surface of the copper layer.

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

For example, the concentration of amidosulfuric acid in the blackening plating solution is not particularly limited, but is preferably, for example, 1 g / l to 50 g / l, and more preferably 5 g / l to 20 g / l. This is because, by setting the concentration of amidosulfuric acid to 1 g / l or more, the blackened layer can be made a color particularly suitable for suppressing light reflection on the surface of the copper layer, and the reflectance of the conductive substrate can be suppressed. It is. Further, even if the amidosulfuric acid is added in excess of 50 g / l, the effect of suppressing the reflectance of the conductive substrate is not significantly changed, so that it is preferably 50 g / l or less as described above.

And, the blackening plating solution of this embodiment can have a pH of, for example, 4.0 or more and 5.8 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 it is possible to form a blackened layer having a color that can particularly suppress the reflection of light. Further, by setting the pH of the blackening plating solution to 5.8 or less, in particular, to 5.3 or less, precipitation of part of components of the blackening plating solution can be suppressed.

In order to make the pH of the blackening plating solution fall in the above range, the blackening plating solution of the present embodiment can contain, for example, an alkaline substance. Examples of the alkaline substance include ammonia (ammonia water) and alkali metal hydroxides such as potassium hydroxide, sodium hydroxide and lithium hydroxide.

And since an alkaline substance functions as a pH adjuster as mentioned above, it is preferable that the blackening plating solution of this embodiment contains an alkaline substance so that the pH may become the said range.

The blackening plating solution of the present embodiment may contain any component other than the components described above. As a component which can be contained optionally, the pit inhibiting agent for nickel plating is mentioned, for example. Examples of the pit prevention agent for nickel plating include Pitless S (trade name) manufactured by Nippon Kagaku Sangyo Co., Ltd., and Nickel Grime NAW 4 (trade name) manufactured by Rohm and Haas.

According to the blackening plating solution of the present embodiment described above, it is possible to form a blackening layer which can be patterned into a desired shape when it is etched together with a copper layer.

Moreover, the blackening plating solution of this embodiment can be suitably used when forming the blackening layer which can fully suppress reflection of the light in the copper layer surface of a conductive substrate. Furthermore, by using the blackening plating solution of the present embodiment, the blackening layer can be formed into a film by a wet method such as electrolytic plating, so that it is compared with the blackening layer conventionally formed by the dry method. Thus, the blackened layer can be formed with good productivity.
(Conductive substrate)
Next, a configuration example of a conductive substrate including a blackening layer formed using the blackening plating solution of the present embodiment will be described.

The conductive substrate of the present embodiment includes a transparent substrate, a copper layer disposed on at least one surface of the transparent substrate, and a blackening layer formed using a blackening plating solution on the copper layer. You can have

The conductive substrate in the present embodiment means a substrate having a copper layer and a blackening layer on the surface of a transparent base before patterning a copper layer or the like, and a substrate having the copper layer or the like patterned, ie, And the wiring board.

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

The transparent substrate is not particularly limited, and a transparent substrate such as a resin substrate (resin film) which transmits visible light or a glass substrate can be preferably used.

As a material of the resin substrate which transmits visible light, for example, resins such as polyamide resin, polyethylene terephthalate resin, polyethylene naphthalate resin, cycloolefin resin, polyimide resin, and polycarbonate resin 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 resin substrate that transmits visible light.

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

The total light transmittance of the transparent substrate is preferably high. For example, the total light transmittance is preferably 30% or more, more preferably 60% or more. When the total light transmittance of the transparent substrate is in the above range, the visibility of the display can be sufficiently ensured, for example, when used for a touch panel application.

The total light transmittance of the transparent substrate can be evaluated by the method defined in JIS K 7361-1.

Next, the copper layer will be described.

The method for forming the copper layer on the transparent substrate is not particularly limited, but it is preferable not to dispose an adhesive between the transparent substrate and the copper layer in order not to reduce the light transmittance. That is, the copper layer is preferably formed directly on at least one surface of the transparent substrate. When the adhesion layer is disposed between the transparent substrate and the copper layer as described later, the copper layer is preferably formed directly on the upper surface of the adhesion layer.

In order to form a copper layer directly on the upper surface of a transparent substrate or the like, the copper layer preferably has a copper thin film layer. Also, the copper layer may have a copper thin film layer and a copper plating layer.

For example, a copper thin film layer can be formed on a transparent substrate by a dry plating method, and the copper thin film layer can be used as a copper layer. Thus, the copper layer can be formed directly on the transparent substrate without the use of an adhesive. As the dry plating method, for example, a sputtering method, a vapor deposition method, an ion plating method and the like can be preferably used.

Moreover, when making the film thickness of a copper layer thick, a copper thin film layer and a copper plating layer are formed by forming a copper plating layer by electroplating which is 1 type of the wet plating method by using a copper thin film layer as a feed layer. It can also be a copper layer having. Since the copper layer has a copper thin film layer and a copper plating layer, the copper layer can be formed directly on the transparent substrate without an adhesive.

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

However, if the copper layer is thick, side etching tends to occur because etching takes time to perform the wiring pattern formation, which may cause problems such as difficulty in forming fine lines. Therefore, the thickness of the copper layer is preferably 5 μm or less, more preferably 3 μm or less.

Further, in particular, in view of lowering the resistance value of the conductive substrate and supplying a sufficient current, for example, the thickness of the copper layer is preferably 50 nm or more, more preferably 60 nm or more, and 150 nm It is more preferable that it is more than.

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

Although the thickness of the copper thin film layer is not particularly limited in any case where the copper layer is constituted of a copper thin film layer or in the case of having a copper thin film layer and a copper plating layer, for example, 50 nm or more and 500 nm It is preferable to set it as the following.

The copper layer can be used as a wiring by patterning it into a desired wiring pattern as described later. And since a copper layer can make electrical resistance value lower than ITO conventionally used as a transparent conductive film, the electrical resistance value of a conductive substrate can be made small by providing a copper layer.

Next, the blackening layer will be described.

The blackening layer can be formed using the blackening plating solution described above. Therefore, for example, after forming a copper layer, it can be formed on the upper surface of the copper layer by a wet method such as electrolytic plating.

The blackening plating solution has already been described, and thus the description thereof is omitted here.

The thickness of the blackening layer is not particularly limited, but is preferably, for example, 30 nm or more, and more preferably 50 nm or more. This is because the reflection of light on the surface of the copper layer can be particularly suppressed by setting the thickness of the blackening layer to 30 nm or more.

The upper limit of the thickness of the blackening layer is not particularly limited, but even if it is thicker than necessary, the time required for film formation and the time required for etching when forming a wiring become longer, and the cost rises Will lead to Therefore, the thickness of the blackening layer is preferably 120 nm or less, and more preferably 90 nm or less.

In addition, when a blackening layer is formed into a film by blackening plating solution as stated above, a blackening layer can be made into the layer containing nickel and copper. Moreover, the component derived from the various addition components contained in the already mentioned blackening plating solution can also be included collectively.

In addition to the above-mentioned transparent base material, copper layer and blackening layer, the conductive substrate may be provided with any layer. For example, an adhesive layer can be provided.

A configuration example of the adhesion layer will be described.

Although the copper layer can be formed on the transparent substrate as described above, when the copper layer is formed directly on the transparent substrate, the adhesion between the transparent substrate and the copper layer may not be sufficient. . For this reason, when a copper layer is directly formed on the upper surface of the transparent substrate, the copper layer may peel off from the transparent substrate during the manufacturing process or during use.

So, in the conductive substrate of this embodiment, in order to improve the adhesiveness of a transparent base material and a copper layer, an adhesion layer can be arranged on a transparent base material. That is, it can also be set as a conductive substrate which has an adhesion layer between a transparent substrate and a copper layer.

By arranging the adhesion layer between the transparent base and the copper layer, the adhesion between the transparent base and the copper layer can be enhanced, and peeling of the copper layer from the transparent base can be suppressed.

The adhesion layer can also function as a blackening layer. For this reason, it becomes possible to suppress also the reflection of the light of the copper layer by the light from the lower surface side of a copper layer, ie, the transparent base material side.

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

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

The adhesion layer can also 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 can further contain one or more elements selected from carbon, oxygen, hydrogen, and nitrogen. At this time, as 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, 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.

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

When the adhesion layer contains one or more elements selected from carbon, oxygen, hydrogen, and nitrogen, the atmosphere for forming the adhesion layer includes one or more elements selected from carbon, oxygen, hydrogen, and nitrogen. Can be added to the adhesive layer by adding a gas containing. For example, carbon monoxide gas and / or carbon dioxide gas when carbon is added to the adhesion layer, oxygen gas when oxygen is added, hydrogen gas and / or water when hydrogen is added, When nitrogen is added, nitrogen gas can be added to the atmosphere at the time of performing dry plating.

A gas containing one or more elements selected from carbon, oxygen, hydrogen, and nitrogen is preferably added to an inert gas and used as an atmosphere gas at the time of dry plating. The inert gas is not particularly limited but, for example, argon can be preferably used.

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

The thickness of the adhesion layer is not particularly limited, but is 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 is also made to function as a blackening layer, that is, when the reflection of light in the copper layer is suppressed, the thickness of the adhesion layer is preferably 3 nm or more as described above.

The upper limit of the thickness of the adhesion layer is not particularly limited, but even if it is thicker than necessary, the time required for film formation and the time required for etching when forming a wiring become longer, and the cost increases. It will incur. Therefore, as described above, the thickness of the adhesive layer is preferably 50 nm or less, more preferably 35 nm or less, and still more 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 copper layer, and a blackening layer. Moreover, layers, such as an adhesion layer, can also be provided optionally.

A specific configuration example will be described below with reference to FIGS. 1A, 1B, 2A, and 2B. FIG. 1A, FIG. 1B, FIG. 2A, and FIG. 2B have shown the example of sectional drawing in the surface parallel to the lamination direction of a transparent base material, a copper layer, and a blackening layer of the conductive substrate of this embodiment.

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

Specifically, for example, as in the conductive substrate 10A shown in FIG. 1A, the copper layer 12 and the blackening layer 13 may be sequentially laminated one by one on one surface 11a side of the transparent substrate 11 it can. Further, as in the case of the conductive substrate 10B shown in FIG. 1B,

copper layers

12A and 12B and black are respectively provided on one surface 11a side of the transparent substrate 11 and the other surface (the other surface) 11b side. And the barrier layers 13A and 13B can be stacked one by one in that order.

Furthermore, for example, an adhesion layer may be provided as an arbitrary layer. In this case, for example, an adhesion layer, a copper layer, and a blackening layer can be formed 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 20A shown in FIG. 2A, the adhesion layer 14, the copper layer 12, and the 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, the adhesion layer, the copper layer, and the blackening layer may be laminated on both sides of the transparent substrate 11. Specifically, as in the case of the conductive substrate 20B shown in FIG. 2B, the adhesion layers 14A and 14B and the

copper layers

12A and 12B are formed on one surface 11a side and the other surface 11b side of the transparent substrate 11, respectively. And the blackening

layers

13A and 13B can be stacked in that order.

In addition, in FIG. 1B and FIG. 2B, when a copper layer, a blackening layer, etc. are laminated on both sides of a transparent substrate, layers laminated on the upper and lower sides of the transparent substrate 11 with the transparent substrate 11 as a symmetry plane become symmetrical. Although the example arrange | positioned as shown was shown, it is not limited to the form which concerns. For example, in FIG. 2B, the configuration on one surface 11a side of the transparent substrate 11 is the same as the configuration of FIG. 1B, in which the copper layer 12A and the blackening layer 13A are laminated in that order without providing the adhesion layer The layers stacked on the upper and lower sides of the transparent substrate 11 may be asymmetric.

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

The degree of reflectance of the conductive substrate of the present embodiment is not particularly limited, but for example, in order to enhance the visibility of the display when used as a conductive substrate for a touch panel, one having a low reflectance Is good. For example, the average reflectance of light with a wavelength of 400 nm or more and 700 nm or less is preferably 60% or less, and more preferably 56% or less.

The measurement of reflectance can be performed by irradiating light to the blackened layer of the conductive substrate. Specifically, for example, when the copper layer 12 and the blackening layer 13 are laminated in this order on one surface 11a side of the transparent substrate 11 as shown in FIG. 1A, the blackening layer 13 is irradiated so as to irradiate light. The surface A of the light can be irradiated with light and measured. In the measurement, light having a wavelength of 400 nm or more and 700 nm or less is irradiated to the blackened layer 13 of the conductive substrate at an interval of 1 nm as described above, for example, and the average value of the measured values is 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 can be configured to have mesh-like wiring.

The conductive substrate provided with the mesh-like wiring can be obtained by etching the copper layer and the blackening layer of the conductive substrate of the present embodiment described above.

For example, a two-layer wiring can be used to form a mesh-like wiring. A specific configuration example is shown in FIG. FIG. 3 is a view of the conductive substrate 30 provided with the mesh-like wiring as viewed from the upper surface side in the stacking direction of the copper layer or the like, and the transparent base material and the copper layer are patterned Layers other than the

interconnections

31A and 31B formed by the formation are omitted. Moreover, the wiring 31B seen through the transparent base material 11 is also shown.

The conductive substrate 30 shown in FIG. 3 has a transparent base 11, a plurality of wirings 31A parallel to the Y-axis direction in the drawing, and a wiring 31B parallel to the X-axis direction. The

wirings

31A and 31B are formed by etching a copper layer, and a blackening layer (not shown) is formed on the upper surface or the lower surface of the

wirings

31A and 31B. The blackening layer is etched to 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. The structural example of arrangement | positioning with the transparent base material 11 and wiring is shown to FIG. 4A and FIG. 4B. 4A and 4B correspond to cross-sectional views taken along the line AA 'of FIG.

First, as shown in FIG. 4A, the

wirings

31A and 31B may be disposed on the upper and lower surfaces of the transparent substrate 11, respectively. In FIG. 4A, blackened

layers

32A and 32B etched in the same shape as the wiring are arranged on the upper surface of the wiring 31A and the lower surface of the wiring 31B.

Moreover, as shown to FIG. 4B, using one set of transparent base materials 11,

wiring

31A, 31B is arrange | positioned on the up-and-down side on both sides of one transparent base material 11, and one wiring 31B is a transparent base material. It may be disposed between the eleven. Also in this case, blackened

layers

32A and 32B etched in the same shape as the wirings are disposed on the top surfaces of the

wirings

31A and 31B. As described above, an adhesion layer may be provided in addition to the copper layer and the blackening layer. For this reason, in any case of FIG. 4A and FIG. 4B, for example, an adhesion layer can be provided between the wiring 31A and / or the wiring 31B and the transparent base material 11. When the adhesion layer is provided, the adhesion layer is also preferably etched to the same shape as the

wirings

31A and 31B.

The conductive substrate having the mesh-like wiring shown in FIGS. 3 and 4A is, for example, a conductive substrate provided with

copper layers

12A and 12B and blackening

layers

13A and 13B on both sides of the transparent substrate 11 as shown in FIG. 1B. Can be formed from a flexible substrate.

The copper layer 12A and the blackening layer 13A on the side of one surface 11a of the transparent substrate 11 are parallel to the Y-axis direction in FIG. 1B. The etching is performed such that a plurality of linear patterns are arranged at predetermined intervals along the X-axis direction. The X-axis direction in FIG. 1B means a direction parallel to the width direction of each layer. Also, the Y-axis direction in FIG. 1B means a direction perpendicular to the paper surface 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 with the copper layer 12B and the blackening layer 13B on the other surface 11b side of the transparent substrate 11 Do the etching to be placed.

By the above operation, the conductive substrate having the mesh-like wiring shown in FIG. 3 and FIG. 4A can be formed. In addition, the etching of both surfaces of the transparent base material 11 can also be performed simultaneously. That is, the etching of the

copper layers

12A and 12B and the blackening layers 13A and 13B may be performed simultaneously. Further, in FIG. 4A, the conductive substrate having an adhesive layer patterned in the same shape as the

wires

31A and 31B between the

wires

31A and 31B and the transparent substrate 11 is the conductive substrate shown in FIG. 2B. It can produce by performing etching similarly using.

The conductive substrate having the mesh-like wiring shown in FIG. 3 can also be formed by using two conductive substrates shown in FIG. 1A or FIG. 2A. A case where two conductive substrates shown in FIG. 1A are formed will be described by way of example. For the two conductive substrates shown in FIG. 1A, a plurality of copper layers 12 and blackening layers 13 are respectively formed in parallel with the X axis direction The etching is performed such that the linear patterns of are arranged at predetermined intervals along the Y-axis direction. Then, by aligning two conductive substrates in a direction such that the linear patterns formed on the conductive substrates by the above etching process intersect with each other, a conductive substrate provided with a mesh-like 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 in which the copper layer 12 and the like are laminated and the other surface 11b in FIG. 1A in which the copper layer 12 and the like are not laminated are bonded to obtain the structure shown in FIG. It can also be done.

Further, for example, the other surfaces 11b in FIG. 1A where the copper layer 12 and the like of the transparent base material 11 are not laminated may be bonded to each other to have a cross section shown in FIG. 4A.

In FIGS. 4A and 4B, a conductive substrate 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 shown in FIG. 1A. It can manufacture by using the conductive substrate shown to FIG. 2A instead of a conductive substrate.

The width of the wires and the distance between the wires in the conductive substrate having the mesh-like wires shown in FIGS. 3, 4A and 4B are not particularly limited, and, for example, according to the amount of current flowing in the wires It can be selected.

However, according to the conductive substrate of the present embodiment, the blackening layer formed using the above-described blackening plating solution is provided, and the blackening layer and the copper layer are simultaneously etched and patterned In some cases, the blackening layer and the copper layer can be patterned into the desired shape. Specifically, for example, a wire having a wire width of 10 μm or less can be formed. For this reason, the conductive substrate of the present embodiment preferably includes a wire having a wire width of 10 μm or less. The lower limit of the wiring width is not particularly limited, but can be, for example, 3 μm or more.

Moreover, although the example which formed mesh-like wiring (wiring pattern) combining the wiring of linear shape in FIG. 3, FIG. 4 A and FIG. 4B is shown, it is not limited to the form which concerns, A wiring pattern The wiring which comprises can be made into arbitrary shapes. For example, the shapes of the wires forming the mesh-like wiring pattern may be various shapes such as lines (zigzag straight lines) bent in a jagged manner so as not to generate moire (interference fringes) with the image of the display.

Thus, the conductive substrate having mesh-like wiring composed of two layers of wiring can be preferably used, for example, as a conductive substrate for a projected capacitive touch panel.

According to the conductive substrate of the present embodiment described above, the blackening layer is laminated on the copper layer formed on at least one surface of the transparent substrate. And, since the blackening layer is formed using the blackening plating solution described above, as described above, when patterning the copper layer and the blackening layer by etching, the blackening layer is easily formed. It can be patterned into a desired shape.

Moreover, the blackening layer contained in the conductive substrate of this embodiment can fully suppress reflection of the light in the copper layer surface, and can be used as the conductive substrate which suppressed the reflectance. Also, for example, when used for applications such as touch panels, the visibility of the display can be enhanced.

Furthermore, since the blackening layer can be formed by the wet method using the blackening plating solution described above, the conductive substrate can be produced with high productivity as compared with the case where the blackening layer is formed using the conventional dry method. It can be produced.
(Method of manufacturing conductive substrate)
Next, one configuration example of the method of manufacturing the conductive substrate of the present embodiment will be described.

The method for producing a conductive substrate of the present embodiment can have the following steps.
Copper layer formation process of forming a copper layer on at least one side of a transparent substrate.
Blackening layer formation process which forms a blackening layer using a blackening plating solution on a copper layer.

As the blackening plating solution, it is possible to use the blackening plating solution described above, specifically, a blackening plating solution containing nickel ions and copper ions and having a pH of 4.0 to 5.8. it can.

The method of manufacturing the conductive substrate of the present embodiment will be specifically described below.

In addition, the electroconductive substrate as stated above can be suitably manufactured with the manufacturing method of the electroconductive substrate of this embodiment. For this reason, since it can be set as the structure similar to the case of a conductive substrate as stated above except for the point demonstrated below, one part description is abbreviate | omitted.

The transparent substrate to be subjected to the copper layer forming step can be prepared in advance. The kind of transparent substrate to be used is not particularly limited, but as described above, a transparent substrate such as a resin substrate (resin film) that transmits visible light, a glass substrate, etc. can be preferably used. The transparent substrate can be cut into any size in advance, if necessary.

And as mentioned above, it is preferable that a copper layer has a copper thin film layer. The copper layer can also have a copper thin film layer and a copper plating layer. For this reason, a copper layer formation process can have a process of forming a copper thin film layer by dry plating, for example. In the copper layer forming step, a step of forming a copper thin film layer by dry plating, a step of forming a copper plating layer by electroplating, which is a kind of wet plating, using the copper thin film as a feeding layer, May be included.

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

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

Next, the blackening layer forming step will be described.

In the blackening layer forming step, the blackening layer can be formed using a blackening plating solution containing a nickel ion and a copper ion as described above and having a pH of 4.0 to 5.8.

The blackened layer can be formed by a wet method. Specifically, for example, using a copper layer as a feed layer, a blackening layer can be formed on the copper layer by electrolytic plating in a plating tank containing the above-described blackening plating solution. By thus forming the blackening layer by electrolytic plating using the copper layer as the feeding layer, the blackening layer can be formed on the entire surface of the copper layer opposite to the side facing the transparent base.

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

In the method of manufacturing a conductive substrate of the present embodiment, an arbitrary step can be further performed in addition to the above-described steps.

For example, when forming an adhesion layer between a transparent base material and a copper layer, an adhesion layer formation process which forms an adhesion layer on the field which forms a copper layer of a transparent base material can be carried out. When the adhesion layer formation step is carried out, the copper layer formation step can be carried out after the adhesion layer formation step, and in the copper layer formation step, copper is formed on the substrate on which the adhesion layer is formed on the transparent substrate in this step. A thin film layer can be formed.

In the adhesion layer forming step, the film formation method of the adhesion layer is not particularly limited, but it is preferable to form a film by a dry plating method. As the dry plating method, for example, a sputtering method, an ion plating method, a vapor deposition method and the like can be preferably used. In the case where the adhesion layer is formed by a dry method, it is more preferable to use a sputtering method because control of the film thickness is easy. As described above, one or more elements selected from carbon, oxygen, hydrogen and nitrogen can be added to the adhesion layer, and in this case, reactive sputtering 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 example, in various applications such as a touch panel. And when using for various uses, it is preferable that the copper layer contained in the conductive substrate of this embodiment, and a blackening layer are patterned. When the adhesion layer is provided, it is preferable that the adhesion layer is also patterned. The copper layer and the blackening layer, and optionally also the adhesion layer, can be patterned, for example, according to the desired wiring pattern, and the copper layer and the blackening layer, optionally also the adhesion layer, are patterned in the same shape It is preferable that the

For this reason, the manufacturing method of the conductive substrate of this embodiment can have a patterning step of patterning a copper layer and a blackening layer. When the adhesion layer is formed, the patterning step can be a step of patterning the adhesion layer, the copper layer, and the blackening layer.

The specific procedure of the patterning step is not particularly limited, and can be performed by any procedure. For example, in the case of the conductive substrate 10A in which the copper layer 12 and the blackening layer 13 are stacked on the transparent substrate 11 as shown in FIG. 1A, first, a resist having a desired pattern is disposed on the surface A on the blackening layer 13. A resist placement step can be performed. Then, an etching step can be performed in which the etchant is supplied to the surface A on the blackening layer 13, that is, the side on which the resist is disposed.

The etchant used in the etching step is not particularly limited. However, the blackening layer formed by the method of manufacturing a conductive substrate of the present embodiment exhibits the same reactivity to the etching solution as the copper layer. Therefore, the etching solution used in the etching step is not particularly limited, and an etching solution generally used for etching the copper layer can be preferably used.

For example, a mixed aqueous solution containing one or more selected from sulfuric acid, hydrogen peroxide (hydrogen peroxide water), hydrochloric acid, cupric chloride and ferric chloride can be preferably used as the etching solution. The content of each component in the etching solution is not particularly limited.

The etching solution can be used at room temperature, but can also be used by heating to enhance the reactivity, for example, it can be used by heating to 40 ° C. or more and 50 ° C. or less.

In addition, as shown in FIG. 1B, the patterning process is performed to pattern the conductive substrate 10B in which the

copper layers

12A and 12B and the blackening layers 13A and 13B are laminated on one surface 11a and the other surface 11b of the transparent substrate 11. 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. Then, an etching step may be performed in which the etching solution is supplied to the surface A and the surface B on the blackened

layers

13A and 13B, that is, the surface on which the resist is disposed.

The pattern to be formed in the etching step is not particularly limited, and may have an arbitrary shape. For example, in the case of the conductive substrate 10A shown in FIG. 1A, as described above, the copper layer 12 and the blackening layer 13 should be patterned to include a plurality of straight lines and lines (zigzag straight lines) bent into jagged lines. Can.

Further, in the case of the conductive substrate 10B shown in FIG. 1B, the copper layer 12A and the copper layer 12B can form a pattern so as to form a mesh-like wiring. In this case, the blackening layer 13A is preferably patterned to have the same shape as the copper layer 12A, and the blackening layer 13B is preferably patterned to have the same shape as the copper layer 12B.

Further, for example, after the copper layer 12 or the like is patterned on the above-described conductive substrate 10A in the patterning step, a stacking step may be performed in which two or more patterned conductive substrates are stacked. When laminating, for example, by laminating so that the patterns of copper layers of the respective conductive substrates intersect, it is possible to obtain a laminated conductive substrate provided with a mesh-like wiring.

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

The conductive substrate obtained by the method for producing a conductive substrate of the present embodiment described above has a structure in which a blackening layer is laminated on a copper layer formed on at least one surface of a transparent substrate. . And, since the blackening layer is formed using the above-described blackening plating solution, when patterning the copper layer and the blackening layer by etching, the blackening layer is easily patterned into a desired shape. can do.

In addition, the blackening layer contained in the conductive substrate obtained by the method of manufacturing a conductive substrate according to the present embodiment sufficiently suppresses the reflection of light on the surface of the copper layer to provide a conductive substrate in which the reflectance is suppressed. Can. For this reason, when it uses, for example for uses, such as a touch panel, the visibility of a display can be improved.

Furthermore, since the blackening layer can be formed by the wet method using the blackening plating solution described above, the conductive substrate can be produced with high productivity as compared with the case where the blackening layer is formed using the conventional dry method. It can be produced.

The present invention will be described by way of specific examples and comparative examples, but the present invention is not limited to these examples.
(Evaluation method)
First, an evaluation method of the obtained conductive substrate will be described.
(1) Reflectance Measurement was performed by installing a reflectance measurement unit in an ultraviolet-visible spectrophotometer (manufactured by Shimadzu Corporation, model: UV-2600).

As described later, in each of the experimental examples, a conductive substrate having a structure shown in FIG. 1A was produced. For this reason, the reflectance measurement is performed with light having a wavelength of 400 nm or more and 700 nm or less at an interval of 1 nm with an incident angle of 5 ° and a light receiving angle of 5 ° The specular reflectance was measured by irradiation, and the average value was taken as the reflectance (average reflectance) of the conductive substrate.
(2) Etching Properties First, a dry film resist (Hitachi Chemical RY 3310) 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. Thus, a sample having a pattern in which the resist width differs every 0.5 μm in the range of 3.0 μm to 10.0 μm was produced. That is, 15 different linear patterns were formed every resist width of 3.0 μm, 3.5 μm, 4.0 μm,... 9.5 μm, 10.0 μm and 0.5 μm.

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

The obtained sample was observed with a 200 × microscope to determine the minimum value of the wiring width of the metal wiring remaining on the conductive substrate. The metal wiring here includes a blackened layer patterned in a linear shape having a wiring width corresponding to a resist width, and a copper layer, that is, a wiring.

As the minimum value of the wiring width of the metal wiring remaining on the conductive substrate is smaller after stripping the resist, it means that the reactivity of the copper layer and the blackening layer to the etching solution is closer to the same, which remains When the minimum value of the wiring width of the metal wiring is 10 μm or less, it was evaluated as 合格 in Table 2 as a pass. Further, when a metal wiring having a wiring width of 10 μm could not be formed, it was evaluated as x in Table 2 as a rejection.
(Sample preparation conditions)
In each of the following experimental examples, a conductive substrate was produced under the conditions described below, and evaluated by the above-described evaluation method.

Experimental Examples 1 to 12 are Examples, and Experimental Examples 13 to 25 are Comparative Examples.
[Experimental Example 1]
(1) Blackening Plating Solution In Experimental Example 1, a blackening plating solution containing nickel ions, copper ions, amidosulfuric acid and ammonia was prepared. In addition, nickel ions and copper ions were supplied to the blackening plating solution by adding nickel sulfate hexahydrate and copper sulfate pentahydrate.

Then, each component was added and prepared so that the concentration of nickel ion in the blackening plating solution was 8.9 g / l, the concentration of copper ion was 0.05 g / l, and the concentration of amidosulfuric acid was 11 g / l.

Further, ammonia water was added to the blackening plating solution to adjust the pH of the blackening plating solution to 4.0.
(2) Conductive substrate (copper layer forming process)
A copper layer was formed on one side of a transparent base made of a long polyethylene terephthalate resin (PET) having a length of 100 m, a width of 500 mm, and a thickness of 100 μm. The total light transmittance of the transparent substrate made of polyethylene terephthalate resin used as the transparent substrate was evaluated by the method defined in JIS K 7361-1 and found to be 97%.

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

First, the copper thin film layer forming process will be described.

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

In the copper thin film layer forming step, first, the above-mentioned transparent substrate from which water was removed by heating in advance to 60 ° C. was placed in the chamber of the sputtering apparatus.

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

Electric power was supplied to a copper target previously set at the cathode of the sputtering apparatus, and a copper thin film layer was formed to a thickness of 0.2 μm on one surface of the transparent substrate.

Next, in the copper plating layer forming step, a copper plating layer was formed. 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-described copper thin film layer forming step and the copper plating layer forming step, a copper layer having a thickness of 0.5 μm was formed as a copper layer.

The substrate having the 0.5 μm thick copper layer formed on the transparent substrate, which was prepared in the copper layer forming step, was immersed in 20 g / l sulfuric acid for 30 seconds and washed, and the following blackening layer forming step was carried out. .
(Blackening layer formation process)
In the blackening layer forming step, a blackening layer was formed on one surface of the copper layer by electrolytic plating using the blackening plating solution of the above-mentioned experimental example. In the blackening layer forming step, electroplating was performed under the conditions of a blackening plating solution temperature of 40 ° C., a current density of 0.2 A / dm ² , and a plating time of 100 seconds to form a blackening layer.

The film thickness of the formed blackened layer was 70 nm.

With respect to the conductive substrate obtained by the above steps, the evaluation of the reflectance and the etching characteristic described above was performed. The results are shown in Tables 2 and 3. Table 2 shows the evaluation results of the etching characteristics, and Table 3 shows the evaluation results of the reflectance.
[Experimental Example 2 to Experimental Example 25]
When preparing the blackening plating solution, it is the same as the case of Experimental example 1 except that the concentration of copper ions in the blackening plating solution and the pH are changed to the values shown in Table 1 for each experimental example. The blackening plating solution was prepared.

In the case of Experimental Example 2, for example, the concentration of copper ions is 0.10 g / l, and the pH is 4.0.

Further, a conductive substrate was produced and evaluated in the same manner as in Experimental Example 1 except that the blackening plating solution prepared in each of the experimental examples was used when forming the blackening layer.

The results are shown in Tables 2 and 3.

In Tables 2 and 3, locations corresponding to the numbers of the experimental examples shown in Table 1 indicate the results of the respective experimental examples. For example, the places where the copper ion concentration shown as Experimental Example 2 in Table 1 is 0.10 g / l and the pH is 4.0 show the results of Experimental Example 2 also in Tables 2 and 3.

From the results shown in Table 2, using the blackening plating solution of Experimental Example 1 to Experimental Example 12 containing a nickel ion and a copper ion and having a pH of 4.0 or more and 5.8 or less, It was confirmed that the minimum value of the wiring width of the metal wiring pattern formed and left after etching was 10 μm or less. Therefore, in the conductive substrate having the blackened layer formed by using these blackening plating solutions, it can be confirmed that the blackened layer can be patterned into a desired shape when the blackened layer is etched together with the copper layer. Further, from the results shown in Table 3, the conductive substrate having the blackening layer formed using the blackening plating solution of Experimental Example 1 to Experimental Example 12 has an average specular reflectance of light having a wavelength of 400 nm or more and 700 nm or less. It could be confirmed that the value (reflectance) was also 60% or less.

On the other hand, in the experimental examples 13 and 18 to 20 which are comparative examples, it was confirmed that no pattern of metal wiring having a wiring width of 10 μm remains after etching. Therefore, it has been confirmed that it is difficult to pattern the blackened layer into a desired shape when the blackened layer is formed using these blackening plating solutions and etched together with the copper layer.

Further, in Experimental Examples 21 to 25, a precipitate was generated in the plating solution, and a blackened layer could not be formed.

Then, in Experimental Examples 14 to 17, although it was confirmed that the minimum value of the wiring width of the pattern of the metal wiring remaining after etching is 10 μm or less, uneven plating occurs in the formed blackened layer. , Could not be used as a conductive substrate.

Although the method for manufacturing the blackening plating solution and the conductive substrate has been described above in the embodiments and examples and the like, the present invention is not limited to the embodiments and the examples and the like. Various changes and modifications are possible within the scope of the present invention as set forth in the claims.

This application claims the priority of Japanese Patent Application No. 2016-016592 filed on Jan. 29, 2016 based on Japanese Patent Office, and the entire contents of Japanese Patent Application No. 2016-016592 I will use it.

Claims

Containing nickel ions and copper ions,
A blackening plating solution having a pH of 4.0 to 5.8.
The blackening plating solution according to claim 1, further comprising amidosulfuric acid.
The blackening plating solution according to claim 1 or 2, wherein the nickel ion concentration is 2.0 g / l or more and 20.0 g / l or less and the copper ion concentration is 0.005 g / l or more and 1.02 g / l or less.
A copper layer forming step of forming a copper layer on at least one surface of the transparent substrate;
A method for producing a conductive substrate, comprising: forming a blackening layer on the copper layer using the blackening plating solution according to any one of claims 1 to 3.