TW201806754A - Conductive substrate and method for producing conductive substrate - Google Patents

Abstract

Provided is a conductive substrate which comprises a transparent base and metal wiring lines that are formed on at least one surface of the transparent base, and wherein: each metal wiring line has a structure in which a copper wiring layer and a blackened wiring layer containing nickel and copper are laminated; and the transparent base exposed between the metal wiring lines has a visible light transmittance of 90% or more and a b* value of 1.0 or less.

Description

Conductive substrate and method for manufacturing conductive substrate

The present invention relates to a conductive substrate and a method for manufacturing a conductive substrate.

The electrostatic capacitive touch panel detects a change in electrostatic capacity caused when an object approaches the surface of the panel, and converts position information of the approaching object on the surface of the panel into an electrical signal. The conductive substrate used in the capacitive touch panel is provided on the surface of the display. Therefore, the material of the conductive layer of the conductive substrate is required to have a low reflectance and be difficult to identify.

Therefore, as a material of a conductive layer used in a capacitive touch panel, a material having a low reflectance and difficult to identify is currently used to form wiring 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. The transparent conductive film is made of a metal oxide formed on the polymer film by a vapor-phase film forming method. The film is characterized in that the transparent conductive film made of a metal oxide includes a transparent conductive film made of a first metal oxide and a transparent conductive film provided on the first metal oxide and made of a second metal oxide. In addition, the film formation conditions of the transparent conductive film made of the second metal oxide are different from the film formation conditions of the transparent conductive film made of the first metal oxide. It is also disclosed that the transparent conductive film made of a metal oxide is an indium oxide-tin oxide (ITO) film.

However, in recent years, displays equipped with a touch panel have continued to increase the screen size and performance, and as a material for the conductive layer, the use of metals such as copper instead of high-resistance materials has been studied. ITO (for example, refer to Patent Documents 2 and 3). However, since metal has metallic luster, there is a problem that the visibility of the display is reduced due to reflection. Therefore, while studying a metal layer having copper or the like as a conductive layer, a conductive substrate having a blackened layer made of a black material is also studied.

<Prior Art Literature>

<Patent Literature>

Patent Document 1: (Japanese Patent Laid-Open No. 2003-151358

Patent Document 2: (Japanese Patent Laid-Open No. 2011-018194)

Patent Document 3: (Japanese Patent Application Publication No. 2013-069261)

In order to produce a conductive substrate including a metal layer such as copper and a blackened layer as the metal wiring constituting the wiring pattern as described above, it is necessary to prepare a multilayer substrate in which a metal layer and a blackened layer are previously laminated on a base material, and the In the pattern of the wiring, the metal layer and the blackened layer are etched.

However, metal layers such as copper and blackening layers have different reactivity to the etching solution, so the blackening layer cannot be completely removed, and residues of the blackening layer may remain in the openings between the metal wirings, resulting in exposure of the openings. The visible light transmittance of the transparent substrate is reduced.

In view of the above-mentioned problems of the prior art, an object of one aspect of the present invention is to provide a conductive substrate having a high visible light transmittance of a transparent base material exposed between metal wirings.

In order to achieve the above object, an aspect of the present invention provides a conductive substrate including a transparent substrate and metal wiring formed on at least one surface of the transparent substrate, the metal wiring having a copper wiring layer and a blackened wiring layer layer The blackened wiring layer contains nickel and For copper, the visible light transmittance of the transparent substrate exposed between the metal wirings is 90% or more, and b * is 1.0 or less.

According to one aspect of the present invention, it is possible to provide a conductive substrate with high visible light transmittance of a transparent substrate exposed between metal wirings.

10A, 10B, 20A, 20B ‧‧‧ laminated substrate

30, 40‧‧‧ conductive substrate

11, 11A, 11B ‧‧‧ transparent substrate

12, 12A, 12B‧‧‧ Copper

13, 13A, 13B, 131, 132, 131A, 132A, 131B, 132B‧‧‧ Blackened layer

14, 14A, 14B, 24, 24A, 24B ‧‧‧ metal laminate

32, 42A, 42B, 62‧‧‧ copper wiring layers

33, 431A, 432A, 431B, 432B, 631, 632‧‧‧blackened wiring layer

34, 44A, 44B‧‧‧ metal wiring

FIG. 1A is a cross-sectional view of a multilayer substrate according to an embodiment of the present invention.

FIG. 1B is a cross-sectional view of a multilayer substrate according to an embodiment of the present invention.

2A is a cross-sectional view of a multilayer substrate according to an embodiment of the present invention.

2B is a cross-sectional view of a multilayer substrate according to the embodiment of the present invention.

3 is a cross-sectional view of a conductive substrate according to an embodiment of the present invention.

FIG. 4 is a plan view of a conductive substrate having a grid-like wiring according to an embodiment of the present invention.

Fig. 5A is a sectional view taken along the line A-A 'in Fig. 4.

Fig. 5B is a sectional view taken along the line A-A 'in Fig. 4.

FIG. 6A is an explanatory diagram of an etching step.

FIG. 6B is an explanatory diagram of an etching step.

FIG. 6C is an explanatory diagram of an etching step.

FIG. 6D is an explanatory diagram of an etching step.

Hereinafter, an embodiment of the conductive substrate and the method for manufacturing a conductive substrate according to the present invention will be described with reference to the drawings.

Here, the same reference numerals are given to the same members, and the description of the parts is omitted.

The conductive substrate of this embodiment may have a transparent base material and a metal wiring formed on at least one surface of the transparent base material.

In addition, the metal wiring may have a structure of a copper wiring layer and a blackened wiring laminated layer including nickel and copper. The visible light transmittance of the transparent substrate exposed between the metal wirings is 90% or more, and b * is 1.0 or less.

In addition, the laminated body substrate in this embodiment means a substrate of a metal laminated body in which a copper layer and a blackened layer are provided on the surface of a transparent base material before a copper layer or the like is patterned. The conductive substrate means a substrate on which a copper layer and a blackened layer have been patterned into a desired wiring pattern, that is, a wiring substrate. Since the conductive substrate includes a region where the transparent substrate is not covered by a copper layer or the like, light can be transmitted to become a transparent conductive substrate.

The conductive substrate according to this embodiment can be produced by using a metal laminate including a transparent substrate and at least one surface formed on the transparent substrate, and the metal laminate having a copper layer and a layer including nickel and copper. A multilayer substrate having a structure in which a laminated layer is blackened "is used to pattern the copper layer and the blackened layer. Therefore, a configuration example of the multilayer substrate of this embodiment will be described first.

(Laminate substrate)

First, each member included in the multilayer substrate of this embodiment will be described.

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

As the insulator film that can transmit visible light, for example, a polyamine film, a polyethylene terephthalate film, and polyethylene 2,6 naphthalate can be preferably used. One or more resin films selected from naphthalate) films, cycloolefin-based films, polyimide-based films, polycarbonate-based films, and the like. In particular, as a material of the insulator film that can transmit visible light, it is more preferable to use PET (polyethylene terephthalate), COP (cycloolefin polymer), and PEN (polyethylene 2,6 naphthalate). ), Polyimide, polyamidine, polycarbonate, and the like selected from one or more.

The thickness of the transparent substrate is not particularly limited, and can be arbitrarily selected according to the strength, capacitance, light transmittance, and the like required as a conductive substrate. The thickness of the transparent substrate may be, for example, 10 μm or more and 200 μm or less. In particular, when it is used for a touch panel application, 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. In the case of use for a touch panel application, for example, an application in which the thickness of the entire display is particularly required to be reduced, the thickness of the transparent substrate is more preferably 20 μm or more and 50 μm or less.

The transparent substrate preferably has a high visible light transmittance. For example, the visible light transmittance is preferably 90% or more. The reason is that when the visible light transmittance of the transparent substrate is 90% or more, for example, when it is used for a touch panel application, the visibility of the display can be sufficiently ensured.

The visible light transmittance of the transparent substrate can be evaluated in accordance with a method prescribed by JIS K 7361-1.

Next, a metal laminate will be described. The metal laminate may have a structure including a copper layer and a blackened layer including nickel and copper.

First, the copper layer will be described.

The copper layer may be composed of copper. In addition, it may contain unavoidable components caused by mixing in a manufacturing process, such as a target or a plating solution.

The method for forming the copper layer is not particularly limited, but in order to avoid a decrease in light transmittance, it is preferable not to arrange an adhesive between other members and the copper layer. That is, it is preferably on The copper layer is directly formed on the surface. A copper layer may be formed on the blackened layer or the transparent substrate. Therefore, the copper layer is preferably formed directly on the blackened layer or the transparent substrate.

In order to form a copper layer directly on other members, it is preferable that the copper layer has a copper thin film layer formed by a dry plating method. The dry plating method is not particularly limited, and for example, a vapor deposition method, a sputtering method, an ion plating method, or the like can be used. In particular, since the sputtering method is easy to control the film thickness, the sputtering method is preferably used.

In the case of further thickening the copper layer, a wet plating method may be adopted after the dry plating method, and the copper plating layer may be laminated on the copper film layer. Specifically, for example, a copper thin film layer can be formed on a transparent substrate or a blackened layer by a dry plating method, and then the copper thin film layer can be used as a power supply layer, and a copper plating can be formed by using a plating method as one of the wet plating methods. Floor.

When the copper layer is formed only by the dry plating method as described above, the copper layer may be composed of a copper thin film layer. When a copper layer is formed by combining a dry plating method and a wet plating method, the copper layer may be composed of a copper thin film layer and a copper plating layer.

As described above, by using only a dry plating method, or a combination of a dry plating method and a wet plating method to form a copper layer, a copper layer can be directly formed on a transparent substrate or a blackened layer without using an adhesive.

The thickness of the copper layer is not particularly limited. In the case where the copper layer is patterned to form a copper wiring layer, it can be arbitrarily selected according to the magnitude of the current provided to the copper wiring layer, the wiring width, and the like.

However, if the copper layer is thickened, when etching is performed to form a wiring pattern, since more etching time is required, side etching is likely to occur, and problems such as difficulty in forming fine lines may occur. Therefore, the thickness of the copper layer is preferably 5 μm or less, and more preferably 1 μm or less.

In addition, in particular, from the viewpoint of reducing the resistance value of the conductive substrate and capable of sufficiently supplying current, for example, the thickness of the copper layer is preferably 50 nm or more, more preferably 60 nm or more, and even more preferably 150 nm or more.

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

The thickness of the copper thin film layer is not particularly limited in the case where the copper layer is composed of a copper thin film layer or the copper thin film layer and the copper plating layer, but it is preferably 50 nm to 500 nm, for example.

The blackening layer will be described below.

The copper layer has a metallic luster. Therefore, if the metal wiring layer is formed by only etching the copper layer on a transparent substrate, the wiring will reflect light. For example, when a wiring substrate for a touch panel is used, there is a display. Reduced recognition issues. Therefore, a method of providing a blackened wiring layer on the surface of the metal wiring layer where light reflection is to be suppressed is being studied.

However, the reactivity of the copper layer and the blackening layer with respect to the etching solution is different, and the blackening layer cannot be completely removed in some cases. The residue of the blackening layer may remain in the opening portion between the metal wirings, so that the opening portion is transparent. A problem that the visible light transmittance of the substrate is reduced.

Therefore, the inventors of the present invention have found that by providing a blackening layer as a layer containing nickel and copper and using a predetermined etching solution, a transparent substrate having a high visible light transmittance exposed at an opening portion of a metal wiring can be produced. A conductive substrate has completed the present invention.

The blackened layer of the conductive substrate of this embodiment may include nickel and copper, and may further include, for example, oxygen. In particular, the blackened layer of the conductive substrate of this embodiment may be made of nickel, copper, and oxygen.

As described above, by including nickel and copper in the blackening layer, light reflection on the surface of the copper layer can be sufficiently suppressed, and even when the copper layer and the blackening layer are patterned, the blackness on the surface of the transparent substrate can be suppressed. Residue of the coating.

The method for forming the blackened layer is not particularly limited, and any method can be selected as long as it can form a layer containing nickel and copper. However, the blackened layer is preferably formed directly on the transparent substrate and / or other members such as the copper layer without transmitting the adhesive. Specifically, as a method for forming a blackened layer, for example, a wet plating method or a dry plating method can be used. In the case of a wet plating method, for example, an electroplating method can be used, and in the case of a dry plating method, for example, a vapor deposition method, a sputtering method, or an ion plating method can be used. When a dry plating method is used, since the thickness control is particularly easy, it is preferable to use a sputtering method.

In addition, when a plurality of blackening layers are arranged in a multilayer substrate, the plurality of blackening layers included in the same multilayer substrate may be formed by the same film forming method or may be formed by different film forming methods.

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

The thickness of the blackened layer is, for example, preferably 15 nm or more, and more preferably 20 nm or more. The blackening layer has a function of suppressing the light reflection of the copper layer. However, when the thickness of the blackening layer is thin, the light reflection of the copper layer may not be sufficiently suppressed in some cases. In view of this, by setting the thickness of the blackened layer to 15 nm or more, it is possible to more reliably suppress reflection on the surface of the copper layer.

The upper limit of the thickness of the blackened layer is not particularly limited. However, if it exceeds the necessary thickness, the time required for etching when forming the metal wiring is extended, and the cost is increased. Therefore, the thickness of the blackened layer is preferably 70 nm or less, and more preferably 50 nm or less.

Hereinafter, a configuration example of the multilayer substrate will be described.

As described above, the multilayer substrate of the present embodiment may include a transparent substrate, a copper layer, and a blackened layer. In this case, the order of laminating a copper layer and a blackening layer on a transparent base material is not specifically limited. Moreover, a copper layer and a blackening layer may be formed in multiple layers, respectively. However, in order to suppress light reflection on the surface of the copper layer, it is preferable to arrange a blackening layer on the surface of the copper layer, in particular, on the surface where the light reflection is to be suppressed. When it is required to particularly suppress light reflection on the surface of the copper layer, a laminated structure in which a blackened layer is formed above and below the copper layer, that is, a structure in which the blackened layer sandwiches the copper layer, may be used.

A specific configuration example will be described below with reference to FIGS. 1A, 1B, 2A, and 2B. FIG. 1 and FIG. 2 show examples of cross-sectional views of a laminated substrate of the present embodiment on a plane parallel to the lamination direction of the transparent substrate, the copper layer, and the blackened layer.

The multilayer substrate of this embodiment may have a structure in which a copper layer and a blackened layer are laminated on at least one surface of a transparent substrate, for example.

Specifically, for example, in the multilayer substrate 10A shown in FIG. 1A, each of the copper layer 12 and the blackened layer 13 may be sequentially laminated on one surface 11 a side of the transparent base material 11. In this case, the metal layer 14 is constituted by the copper layer 12 and the blackened layer 13.

In addition, as shown in FIG. 1B, the multilayer substrate 10B can sequentially stack copper layers 12A, 12B, and black on one surface 11a side and the other surface 11b side of the transparent substrate 11 respectively. Each of the chemical conversion layers 13A and 13B is one layer. In this case, the copper layer 12A and the blackened layer 13A constitute a metal laminate 14A on one surface 11a side, and the copper layer 12B and the blackened layer 13B constitute a metal laminate 14B on the other surface 11b side.

In addition, the lamination order of the copper layers 12 (12A, 12b) and the blackened layer 13 (13A, 13B) is not limited to the example shown in FIGS. 1A and 1B, and may be sequentially started from the transparent substrate 11 side. A blackened layer 13 (13A, 13B) and a copper layer 12 (12A, 12B) are laminated.

Further, for example, a configuration may be adopted in which a plurality of blackening layers are provided on one surface side of the transparent base material 11. In this case, a structure in which a blackened layer, a copper layer, and a blackened layer are sequentially formed on at least one surface of the transparent substrate from the transparent substrate side may be employed.

Specifically, for example, in the multilayer substrate 20A shown in FIG. 2A, the first blackened layer 131, the copper layer 12, and the second blackened layer 132 may be sequentially laminated on one surface 11 a side of the transparent base material 11. In this case, the metal laminate 24 is configured by the first blackened layer 131, the copper layer 12, and the second blackened layer 132.

It should be noted that when the first blackening layer and the second blackening layer are collectively displayed without being individually distinguished, they are only described as blackening layers.

Moreover, it is good also as a structure which laminated | stacked the copper layer, the 1st blackening layer, and the 2nd blackening layer on both surfaces of the transparent base material 11. Specifically, as shown in FIG. 2B, the multilayer substrate 20B may sequentially laminate the first blackened layers 131A, 131A, and 1b on the one surface 11a side and the other surface (the other surface) 11b side of the transparent substrate 11. 131b, copper layers 12A and 12B, and second blackening layers 132A and 132B. In this case, the first blackened layer 131A, the copper layer 12A, and the second blackened layer 132A constitute a metal laminate 24A on one surface 11a side, and the first blackened layer 131B, the copper layer 12B, and the second black The formation layer 132B constitutes a metal laminate 24B on the other surface 11b side.

In addition, FIG. 1B and FIG. 2B show that when the copper layer and the blackened layer are laminated on both sides of the transparent substrate, the transparent substrate 11 is used as a plane of symmetry, and the layers laminated above and below the transparent substrate 11 are symmetrical to each other. An example of arrangement is not limited to this form. For example, the structure of the one surface 11a side of the transparent base material 11 in FIG. 2B may be provided in a form in which the copper layer 12 and the blackened layer 13 are sequentially laminated in the same manner as the structure of FIG. 1A, and the transparent base material 11 may be formed. The upper and lower layers are set in an asymmetric structure.

The laminated body substrate of this embodiment has been described so far. In the laminated body substrate of this embodiment, since the copper layer and the blackened layer are provided on the transparent substrate, light reflection of the copper layer can be suppressed.

(Conductive substrate)

The conductive substrate of this embodiment will be described below.

The conductive substrate of the present embodiment has a form in which the metal laminate of the laminate substrate described above is patterned to form a metal wiring having a predetermined wiring pattern. Therefore, as the transparent substrate, the copper wiring layer, and the blackened wiring layer included in the conductive substrate of this embodiment, the same materials as the transparent substrate, the copper layer, and the blackened layer described in the laminate substrate, or each of them can be used. The appropriate thickness of the member can also be set in the same range. Therefore, with regard to what has been described above, the redundant description will be omitted in the laminated substrate.

Here, FIG. 3 shows a configuration example of a cross-sectional view of each layer of the conductive substrate according to the present embodiment on a plane parallel to the lamination direction.

As shown in FIG. 3, the conductive substrate according to this embodiment includes a transparent substrate 11 and metal wirings 34 formed on at least one surface of the transparent substrate 11. The metal wirings 34 may include a copper wiring layer 32, A structure in which a copper blackened wiring layer 33 is laminated.

The conductive substrate 30 shown in FIG. 3 can be formed by, for example, patterning the metal laminate 14 of the laminate substrate 10A shown in FIG. 1A.

Although FIG. 3 shows an example in which the copper wiring layer 32 and the blackened wiring layer 33 are sequentially laminated from the transparent substrate 11 side, the metal wiring 34 is not limited to this embodiment. For example, a configuration in which a blackened wiring layer 33 and a copper wiring layer 32 are sequentially laminated from the transparent substrate 11 side may be adopted. The conductive substrate according to the present embodiment may be formed by, for example, laminating the substrate shown in FIG. 1B, FIG. 2A, or FIG. 2B. The metal laminate of the base substrate is patterned to be produced. When the laminated substrate shown in FIG. 1B or FIG. 2B is used, the metal laminated body 14A (24A) and the metal laminated body 14B (24B) can be patterned to form both sides of the transparent substrate 11 A conductive substrate having metal wiring. Moreover, when using the laminated body substrate shown to FIG. 2A and FIG. 2B, for example, the conductive substrate which has the metal wiring in which the copper wiring layer was arrange | positioned between the blackened wiring layers can be formed.

In the conductive substrate of the present embodiment, the visible light transmittance of the transparent substrate 11 exposed from between the metal wirings 34 is preferably 90% or more.

The reason is that when the visible light transmittance of the transparent base material 11 exposed between the metal wirings 34 is 90% or more, it means that the surface of the transparent base material in the openings between the metal wirings formed by patterning the metal laminate is formed. , Almost no residue of the blackened layer remains. In addition, when the visible light transmittance of the transparent substrate 11 exposed from between the metal wirings 34 is 90% or more, for example, when it is used as a conductive substrate for a touch panel, the visibility of the display can be significantly improved. Therefore, the visible light transmittance is preferred. More than 90%.

The visible light transmittance of the transparent substrate exposed from between the metal wirings herein refers to, for example, the visible light transmittance of the transparent substrate 11 exposed from the opening 35 between the metal wirings 34 in FIG. 3. In addition, when a conductive substrate is produced using a multilayer substrate in which a metal laminate is provided on one side and the other side of the transparent substrate as shown in FIG. 1B or 2B, the transparent substrate is referred to as a transparent substrate. The visible light transmittance of the part of one side and the other side of which is not covered by the metal wiring.

The visible light transmittance means, for example, that light having a wavelength of 400 nm to 700 nm is changed at a predetermined interval, specifically, for example, at an interval of 1 nm, and is irradiated to a transparent substrate exposed from a metal wiring space, and The average value of light transmission.

In the conductive substrate of this embodiment, b * of the transparent substrate 11 exposed from between the metal wirings 34, that is, the color of the transmitted light of the transparent substrate 11 exposed from between the metal wirings 34 is converted into CIE (L * a * b *) The b * value in the color system is preferably 1.0 or less. In addition, b * of the transparent base material 11 exposed from between the metal wirings 34 is the same as the above-mentioned case of visible light transmittance. For example, b * of the transparent base material 11 exposed from the opening 35 between the metal wirings 34 in FIG. 3 .

The reason is that when b * of the transparent base material 11 exposed from between the metal wirings 34 is 1.0 or less, it means that the transparent base material surface of the opening portion between the metal wirings 34 formed by patterning the metal laminate is formed. Hardly any residue of the blackened layer remains. In addition, when b * of the openings 35 between the metal wirings 34 is 1.0 or less, for example, when it is used as a conductive substrate for a touch panel, the visibility of the display can be significantly improved. Therefore, b * is preferably 1.0 or less.

The lower limit value of b * is not particularly limited, and may be, for example, 0.1 or more.

For example, b * of the transparent base material 11 exposed from between the metal wirings 34 can be measured based on JIS Z 8722 (revised in 2009) for the transparent base material 11 exposed from the openings 35 between the metal wirings 34.

When a conductive substrate is produced using a multilayer substrate in which a metal laminate is provided on one surface and on the other surface of the transparent substrate as shown in FIG. 1B or FIG. 2B, the conductive substrate is formed on one surface of the transparent substrate. And b * measurement was performed on the two sides of the other side which were not covered by the metal wiring.

The conductive substrate of the present embodiment may be, for example, a conductive substrate having a grid-shaped metal wiring. Hereinafter, a case where the conductive substrate is formed as a grid-shaped metal wiring will be described as an example.

For example, a two-layer metal wiring can be used to form a grid-shaped wiring. Figure 4 shows Specific configuration examples. FIG. 4 shows a view when the conductive substrate 40 having a grid-like wiring is viewed from the upper surface side in the lamination direction of the copper wiring layer and the blackened wiring layer. The conductive substrate 40 shown in FIG. 4 includes a transparent substrate 11, a plurality of metal wirings 44A parallel to the Y-axis direction in the figure, and metal wirings 44B parallel to the X-axis direction. The metal wirings 44A and 44B include a copper wiring layer and a blackened wiring layer, and the copper wiring layer and the blackened wiring layer are preferably etched to have the same shape in cross section on a surface parallel to the surface on which the metal wiring is arranged on the transparent substrate 11 .

The arrangement of the transparent base material 11 and the metal wirings 44A and 44B is not particularly limited. 5A and 5B show examples of the arrangement configuration of the transparent substrate 11 and the metal wiring. 5A and 5B correspond to cross-sectional views taken along line A-A 'in FIG. 4.

First, as shown in FIG. 5A, copper wiring layers 42A and 42B may be arranged on the upper and lower surfaces of the transparent substrate 11, respectively. In addition, in FIG. 5A, the first blackened wiring layers 431A and 431B may be respectively disposed between the copper wiring layers 42A and 42B and the transparent substrate 11, and the first blackened wiring layers 431A and 431B are etched to be transparent with The cross-section of the plane parallel to the plane on which the metal wiring is disposed on the base material 11 has the same shape as that of the copper wiring layer. In addition, second blackened wiring layers 432A and 432B may be disposed on opposite sides of the copper wiring layers 42A and 42B, which are opposite to the surface facing the transparent substrate 11, respectively. The second blackened wiring layers 432A and 432B are etched on The cross-section of the surface of the transparent base material 11 on which the metal wiring is arranged is parallel to the shape of the copper wiring layer.

As shown in FIG. 5B, one set of transparent substrates 11A and 11B may be used, and copper wiring layers 42A and 42B may be arranged above and below one transparent substrate 11A, and one copper wiring layer 42B may be arranged on a transparent substrate. Material 11A, 11B. In the case of FIG. 5B as well, the first blackened wiring layers 431A and 431B may be disposed between the copper wiring layers 42A and 42B and the transparent base materials 11A and 11B. The first blackened wiring layers 431A and 431B are etched into Gold is placed on transparent substrates 11A and 11B A cross section of a plane parallel to the plane of the wiring has the same shape as that of the copper wiring layers 42A and 42. Further, second blackened wiring layers 432A and 432B may be disposed on the opposite sides of the copper wiring layers 42A and 42B on the opposite sides of the surfaces facing the transparent base materials 11A and 11B, respectively. The second blackened wiring layers 432A and 432B are etched into A cross section of a surface parallel to a surface where the metal wirings are arranged on the transparent base materials 11A and 11B has the same shape as the copper wiring layers 42A and 42B.

In any of FIGS. 5A and 5B, the metal wiring 44A is configured by the copper wiring layer 42A, the first blackened wiring layer 431A, and the second blackened wiring layer 432A, and the copper wiring layer 42B and the first blackened wiring layer 431B and the second blackened wiring layer 432B constitute a metal wiring 44B.

5A and 5B show examples in which the first blackened wiring layers 431A and 431B and the second blackened wiring layers 432A and 432B are arranged. However, the present invention is not limited to this configuration and may not include any of them. Structure of the blackened wiring layer. However, it is preferable to arrange the blackened wiring layer on the surface of the copper wiring layer, in particular, to suppress light reflection. Therefore, it is preferable to provide a blackened wiring layer on a surface required to suppress light reflection.

The conductive substrate with grid-shaped wiring shown in FIGS. 4 and 5A can have copper layers 12A and 12B and blackened layers 131A, 132A, 131B, and 132B on both sides of the transparent substrate 11 as shown in FIG. 2B, for example. The laminate substrate is formed.

If a case where the multilayer substrate 20B of FIG. 2B is used as an example is described, first, the copper layer 12A and the blackened layers 131A and 132A of the transparent substrate 11 on the one surface 11a side are etched to Y as in FIG. 2B. A plurality of linear patterns parallel to the axial direction are arranged at predetermined intervals along the X-axis direction. The X-axis direction in FIG. 2B refers to a direction parallel to the width direction of each layer. The Y-axis direction in FIG. 2B refers to a direction perpendicular to the paper surface in FIG. 2B.

Then, the copper layer 12B and the blackened layer on the other surface 11b side of the transparent base material 11 131B and 132B are etched so that a plurality of linear patterns parallel to the X-axis direction in FIG. 2B are arranged along the Y-axis direction with a predetermined pitch.

Through the above operations, a conductive substrate having a grid-like wiring as shown in FIGS. 4 and 5A can be formed. In addition, etching of both surfaces of the transparent base material 11 may be performed simultaneously. That is, the etching of the copper layers 12A and 12B and the blackened layers 131A, 132A, 131B, and 132B may be performed simultaneously.

In addition, if a conductive substrate without the first blackened wiring layers 431A and 431B in FIG. 5A is to be prepared, the multilayer substrate 10B shown in FIG. 1B may be used instead of the multilayer substrate 20B in FIG. 2B. Etching is performed in the same manner to fabricate.

The conductive substrate having a grid-like wiring shown in FIG. 4 can also be formed by using two laminated substrates shown in FIG. 1A or FIG. 2A. Taking a case where a conductive substrate is formed using two laminate substrates 20A of FIG. 2A as an example, the copper laminate 12 and the blackened layers 131 and 132 are respectively used for the two laminate substrates shown in FIG. 2A. A plurality of linear patterns etched parallel to the X-axis direction are arranged along the Y-axis direction with a predetermined pitch. Then, the two patterned laminated substrates are bonded to each other in a uniform direction so that the linear patterns formed on the respective laminated substrates are intersected with each other by the above-mentioned etching process. Conductive substrate. There are no particular limitations on the bonding surface when the two patterned laminated substrates, that is, the conductive substrates are bonded. For example, the surface 132 a of the second blackening layer 132 in FIG. 2A and the surface 11 b of the transparent substrate 11 without the copper layer 12 or the like may be bonded together to form a structure shown in FIG. 5B.

In addition, for example, the surfaces 11 b in FIG. 2A of the non-laminated copper layer 12 and the like of the transparent base material 11 may be bonded to each other so that the cross-section has the structure shown in FIG. 5A.

In addition, the wiring width and the distance between wirings in the conductive substrate having grid-like wiring as shown in FIGS. 4, 5A, and 5B are not particularly limited. The amount of current of the wire is selected.

In addition, FIG. 4, FIG. 5A, and FIG. 5B show an example of forming a grid-like wiring (wiring pattern) by combining linear metal wirings, but the invention is not limited to this form, and the metal wirings constituting the wiring pattern may have any shape. For example, in order to prevent ripples (interference lines) from occurring between the images of the display, the shapes of the metal wirings constituting the grid-shaped wiring pattern may be various shapes such as zigzag curved lines (zigzag straight lines).

As described above, the conductive substrate having the grid-shaped wiring composed of the two-layer metal wiring can be preferably used as a conductive substrate for a touch panel of a projection type, for example.

(Manufacturing method of conductive substrate)

Next, a configuration example of a method for manufacturing a conductive substrate according to this embodiment will be described.

The method for manufacturing a conductive substrate according to this embodiment may include an etching step of performing a metal laminate on a multilayer substrate having a transparent substrate and a metal laminate formed on at least one surface of the transparent substrate. The metal wiring is formed by etching, and the metal laminate has a structure of a copper layer and a blackened layer including nickel and copper.

In addition, the etching step may have the following steps in order.

First etching step: Etching is performed using a first etchant containing one or more kinds selected from ferric chloride, hydrogen peroxide water, sulfuric acid, and hydrochloric acid.

Water washing step: The laminated substrate is washed with water.

Second etching step: Etching is performed using a second etching solution composed of hydrochloric acid and water with a pH of 2.5 or less.

(Etching step)

Regarding the etching steps of the method for manufacturing a conductive substrate according to this embodiment, referring to FIGS. 6A to 6 below FIG. 6D is described.

As shown in FIG. 6A, a laminate substrate having a transparent substrate 11 and a metal laminate 24 formed on at least one surface of the transparent substrate 11 is prepared. The metal laminate 24 may include a copper layer 12 and blackened layers 131 and 132. Here, an example using the laminated substrate 20A shown in FIG. 2A described above is shown in FIG. 6A, but the structure of the laminated substrate is not limited to this form. It is also possible to use a laminate substrate having another structure described above, such as the laminate substrate shown in FIGS. 1A, 1B, and 2B.

In addition, as shown in FIG. 6A, a resist layer having a shape corresponding to the formed metal wiring pattern may be formed on the other surface 24b of the metal laminated body 24 opposite to the one surface 24a opposite to the transparent substrate. 61 (resistor layer forming step).

The method for forming the resist layer 61 is not particularly limited. For example, a photosensitive dry film resist is adhered to the other surface 24 b of the metal laminate 24 by a lamination method to form a photosensitive resist layer. Then, it is irradiated with ultraviolet rays through a photo mask having a wiring pattern of metal wirings formed on the photosensitive resist layer to make it photosensitive.

Then, the photosensitive resist layer can be brought into contact with the developing solution, and a portion not irradiated with ultraviolet rays can be dissolved to form a resist layer 61 having an opening portion 611. The developer is not particularly limited, and for example, an aqueous sodium carbonate solution can be used.

In addition, unlike the case of FIG. 6A, for example, when a laminate substrate provided with metal laminates on both sides of a transparent substrate as shown in FIG. 1B is used as the laminate substrate, the A resist is formed on the opposite side of the opposite surface of the substrate, and the following etching steps are performed.

Then, as shown in FIG. 6B, the first etching step can be performed using the resist layer 61.

In the first etching step, the metal laminate 24 can be etched using a first etching solution containing one or more substances selected from ferric chloride, hydrogen peroxide water, sulfuric acid, and hydrochloric acid. In the first etching step, for example, a first etching solution can be supplied from the upper surface of the resist layer 61 to perform etching. Alternatively, the laminated substrate may be immersed in the first etching solution and etched.

By performing the first etching step, as shown in FIG. 6B, the metal wiring 64 can be formed with the copper wiring layer 62 and the blackened wiring layers 631 and 632 having a shape corresponding to the pattern of the resist layer 61 formed as described above.

However, only in the first etching step, as shown in FIG. 6B, residues 65 such as blackened layers 131 and 132 may be generated in the openings 641 between the metal wirings 64. If a residue 65 is generated in the opening 641 of the metal wiring 64, the transparent substrate 11 cannot be directly exposed in the opening 641, and the transparent substrate 11 is colored due to the residue 65. The conductive substrate is used for touch control. In the case of panel use, the visibility of the display may be reduced.

In contrast, in the etching step of this embodiment, a second etching step can be performed after the first etching step is performed. However, in order to remove the first etching solution used in the first etching step remaining on the laminated substrate, it is preferable to perform the second etching step after the water washing step of washing the laminated substrate with water.

The specific conditions of the water washing step are not particularly limited, and the conductive substrate may be supplied into a water washing tank filled with water and washed with water. Moreover, you may wash | clean by spraying water on the surface of a conductive substrate, for example.

After the water washing step and before the second etching step is performed, a dehydration step, a drying step, or the like may be performed as necessary to remove water adhering to the conductive substrate.

Next, a second etching step will be described.

In the second etching step, the residue 65 between the metal wirings 64 can be etched and removed by using a second etching solution composed of hydrochloric acid and water with a pH value of 2.5 or less.

In the first etching step, the metal laminate 24 can be etched to form a conductive substrate having metal wirings 64 having a shape corresponding to a desired wiring pattern. However, as described above, when the residues 65 are generated in the openings 641 between the metal wirings 64 and the residues 65 remain in the openings between the metal wirings 64, when the conductive substrate is used for a touch panel application. , Will cause the display visibility to be reduced and become a problem.

Therefore, in the method for manufacturing a conductive substrate according to this embodiment, it is possible to etch and remove residues generated between the metal wirings 64 using the second etching solution.

As described above, the second etching solution is preferably composed of hydrochloric acid and water. The reason is that the residue 65 mainly originates from the blackened layers 131 and 132 containing nickel and copper, and the residue 65 also contains nickel and copper as the main components, and in particular, the nickel content is large. Therefore, by using an etching solution composed of hydrochloric acid and water as the second etching solution, the residue 65 can be removed more reliably. Further, by setting the pH value of the second etching solution to 2.5 or less, the reactivity with the residue 65 can be improved, and the residue 65 can be removed more reliably, which is preferable.

When the pH value of the second etching solution is low, an extremely high effect can be exerted when removing the residue. Therefore, the lower limit value is not particularly limited, but in order to suppress the metal formed by the first etching step in the second etching step, Damage to the wiring can be set to a pH of 1.0 or higher, for example.

As described above, by making the blackening layer a layer containing nickel and copper, and using an etching solution composed of hydrochloric acid and water and having a pH value of 2.5 or less as the second etching solution, the openings between the metal wirings can be removed more reliably. The resulting residue. Therefore, a conductive substrate having a good visible light transmittance at the opening can be obtained.

In addition, if a residue remains in the opening portion of the metal wiring room, the transparent base material becomes yellow, and b * of the transparent base material 11 exposed from the metal wiring room may be greater than 1.0. However, by using the predetermined second etching solution, it is possible to more reliably remove the residue generated in the opening portion between the metal wiring rooms. Therefore, b * of the transparent base material 11 exposed from the metal wiring can be made 1.0 or less.

The second etching step can be performed in the same manner as in the case of the first etching step, except that the second etching solution is used as the etching solution. Specifically, for example, the second etching solution may be provided from the upper surface of the resist 61 and implemented. Alternatively, the laminated substrate having completed the first etching step may be immersed in a second etching solution. Thereby, as shown in FIG. 6C, a conductive substrate having metal wiring 64 on the transparent substrate 11 can be formed. The metal wiring 64 has a copper wiring layer 62 and a blackened wiring layer 631 having a pattern corresponding to the resist layer 61. , 632, and the residue 65 existing in the opening portion 641 between the metal wirings 64 can be removed.

After the second etching step is completed, the resist can be removed (resistor removing step).

The method of removing the resist is not particularly limited, and for example, a photosensitive resist can be peeled off and removed using an aqueous sodium hydroxide solution or the like. As a result, as shown in FIG. 6D, a conductive substrate having metal wirings 64 provided on the transparent substrate 11 can be obtained. The metal wirings 64 include blackened wiring layers 631 and 632 and a copper wiring layer 62.

Moreover, in the manufacturing method of the conductive substrate of this embodiment, you may further have an arbitrary process as needed. For example, there may be a laminated substrate manufacturing step of manufacturing a laminated substrate provided to the etching step described above.

(Laminate substrate manufacturing steps)

The laminated substrate manufacturing step may include the following steps. In addition, the manufacturing method of a laminated body substrate corresponds to the manufacturing method of the laminated body substrate of this embodiment mentioned above.

Step of forming a copper layer: forming a copper layer on at least one surface of a transparent substrate.

Step of forming a blackened layer: forming a blackened layer on at least one surface of a transparent substrate.

Moreover, in a laminated body substrate, the order of lamination when a copper layer and a blackening layer are arrange | positioned on a transparent base material is not specifically limited. Moreover, a copper layer and a blackening layer may be formed in multiple layers, respectively. Therefore, there is no particular limitation on the implementation order and the number of times of the steps of forming the copper layer and the blackened layer, and the structure can be carried out at any number of times in accordance with the structure of the laminated substrate to be formed.

Each step is described below.

First, a copper layer forming step is explained.

In the copper layer forming step, a copper layer may be formed on at least one side of the transparent substrate.

The type of the transparent substrate provided to the copper layer forming step or the blackening layer forming step is not particularly limited. As described above, a resin substrate (resin film) or a glass substrate that can transmit visible light can be preferably used. If necessary, the transparent substrate may be cut into any size in advance.

As described above, the copper layer preferably has a copper thin film layer. The copper layer may include a copper thin film layer and a copper plating layer. Therefore, the copper layer forming step may include, for example, a copper thin film layer forming step of forming a copper thin film layer by a dry plating method. The copper layer forming step may include a "copper thin film layer forming step of forming a copper thin film layer by a dry plating method" and "the copper thin film layer is used as a power supply layer and is formed by an electroplating method which is one of the wet plating methods. Copper plating layer forming step ".

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

Next, a copper plating layer forming step for forming a copper plating layer will be described. Regarding the conditions for performing the copper plating layer forming step by the wet plating method, that is, for example, the conditions for the electroplating treatment are not particularly limited, and various conditions in common methods can be adopted. For example, the base material on which the copper thin film layer is formed is placed in a plating bath containing a copper plating solution, and the current density and the transfer speed of the base material are controlled to form a copper plating layer.

Next, a blackening layer forming step is explained.

As described above, the blackening layer forming step is a step of forming a blackening layer film on at least one side of the transparent substrate. The method for forming the blackening layer is not particularly limited, and any method can be selected as long as it can be formed to include nickel and copper. However, it is preferable to directly form a blackened layer on a transparent substrate and / or other members such as a copper layer without using an adhesive. Therefore, the film formation method can be selected according to the configuration of the base layer and the like when the blackened layer is formed. For example, a wet plating method or a dry plating method can be adopted as the film formation method of the blackened layer. In the case of a wet plating method, for example, an electroplating method can be used, and in the case of a dry plating method, for example, a vapor deposition method, a sputtering method, an ion plating method, or the like can be used. When a dry plating method is used, since the thickness control is particularly easy, it is preferable to use a sputtering method. The blackened layer may include oxygen, for example. When a blackened layer containing not only nickel and copper but also oxygen is formed by a dry plating method, the blackened layer can be formed by, for example, a reactive sputtering method. When forming an oxygen-containing blackening layer, oxygen may be added to the film-forming atmosphere of the blackening layer, for example, in an inert gas. As the inert gas, argon or the like can be used.

In addition, when a plurality of blackening layers are arranged in a multilayer substrate, the plurality of blackening layers included in the same multilayer substrate may be formed by the same film formation method, or may be formed by different film formation methods. form.

(Laminating step)

Further, as described above, two laminated substrates having a copper layer and a blackened layer on one surface side of the transparent base material 11 as shown in FIGS. 1A and 2A may be prepared, for example, and a metal laminated body may be patterned. After obtaining a desired metal wiring, bonding is performed to form a conductive substrate having a grid-like wiring.

As described above, when the two patterned laminated substrates are bonded, there may be a bonding step of bonding the two patterned laminated substrates.

The method of bonding two patterned laminated substrates in the bonding step is not particularly limited, and for example, bonding can be performed using an adhesive or the like.

The manufacturing method of the conductive substrate of this embodiment has been described above. According to the manufacturing method of the conductive substrate of this embodiment, it is possible to reduce the residue in the opening portion between the metal wirings. Therefore, it is possible to provide a conductive substrate having a high visible light transmittance and a b * of 1.0 or less from the transparent substrate exposed from the metal wiring. Therefore, for example, when the conductive substrate of the present embodiment is used as a conductive substrate for a touch panel, and it is arranged on the display surface of a display, it is possible to produce a conductive substrate that suppresses a decrease in the visibility of the display.

[Example]

Specific examples and comparative examples will be described below, but the present invention is not limited to these examples.

(Evaluation method)

The samples produced in the examples and comparative examples were evaluated by the following methods.

(1) Visible light transmittance of a transparent substrate exposed in an opening portion between metal wirings

In each of the following examples and comparative examples, the metal laminates 24A and 24B of the laminate substrate having the structure of FIG. 2B were patterned to produce conductive materials having the cross-sectional structure shown in FIG. 5A. Substrate. Therefore, in the conductive substrate shown in FIG. 5A, the opening portion 51 of the metal wiring 44A, that is, a portion of the lower surface of the transparent substrate 11 that is not covered by the metal wiring 44B, is subjected to measurement of visible light transmittance. That is, the visible light transmittance was measured on the upper and lower portions of the transparent substrate 11 that were not covered by the metal wirings 44A and 44B.

The measurement is performed with a spectrophotometer (manufactured by Shimadzu Corporation, model: UV-2600). The transparent substrate 11 is irradiated with light having a wavelength of 400 nm to 700 nm so that its wavelength is changed in units of 1 nm, and the transmittance is measured. The average value was calculated as the visible light transmittance of the transparent substrate exposed at the opening between the transparent substrates.

(2) b * value of the transparent substrate exposed at the opening of the metal wiring room

Using a spectrophotometer, the b * value of the transparent substrate exposed at the opening portion of the metal wiring room was measured in accordance with JIS Z 8722.

(Sample preparation conditions)

As examples and comparative examples, conductive substrates were produced under the conditions described below, and evaluated according to the above-mentioned evaluation methods.

[Experimental Example 1]

The conductive substrates of Experimental Examples 1-1 to Experimental Examples 1-6 shown below were produced and evaluated.

Experimental examples 1-1 to 1-3 are examples, and experimental examples 1-4 to 1-6 are comparative examples.

(Experimental Example 1-1)

According to the following procedure, a conductive substrate having a cross-sectional structure shown in FIG. 5A was produced.

(1) Laminate substrate manufacturing steps

(1-1) First blackening layer forming step

First, a first blackened layer was formed on one surface of a transparent substrate made of polyethylene terephthalate resin (PET) with a thickness of 100 μm and on the other surface on the opposite side of the one surface.

In addition, the transparent substrate made of polyethylene terephthalate resin used as the transparent substrate was evaluated for visible light transmittance according to the method specified in JIS K 7361-1, and the result was 97%.

The first blackening layer was formed by a sputtering method using a nickel-copper alloy target containing 70% by mass of nickel and 30% by mass of copper. At the time of film formation, first, the above-mentioned transparent substrate from which moisture was removed, which was preheated to 60 ° C., was set in a chamber of a sputtering apparatus. Next, the chamber was evacuated to 1 × 10 ^-4 Pa, and then a mixed gas of argon and oxygen was introduced into the chamber to 0.3 Pa, and film formation was performed. In addition, argon and oxygen are mixed and used so that the oxygen content in the mixed gas becomes 30% by volume.

A first blackening layer 131 having a thickness of 20 nm was formed.

(1-2) Copper layer forming step (copper thin film layer forming step)

Next, a copper thin film layer was formed as a copper layer on each of the first blackened layers of the transparent substrate on which the first blackened layer was formed.

Regarding the copper layer, except that a copper target was used as the target, and argon gas was used instead of the mixed gas of argon and oxygen, the other methods were the same as those of the first blackened layer. A copper layer having a thickness of 500 nm was formed on the blackened layer.

(1-3) Second blackening layer forming step

Next, a second blackening layer was formed on each copper layer.

The second blackening layer forming step is performed under the same conditions as in the case of the first blackening layer forming step, and a second blackening layer having a thickness of 20 nm is formed on the copper layer.

Through the above steps, as shown in FIG. 2B, a laminate in which the metal laminates 24A and 24B are respectively arranged on two surfaces of one surface 11 a and the other surface 11 b of the transparent substrate 11 is prepared. Substrate 20B. The metal laminates 24A and 24B are sequentially laminated with first blackened layers 131A and 131B, copper layers 12A and 12B, and second blackened layers 132A and 132B, respectively.

The produced multilayer substrate was cut into 100 mm squares and provided to the following etching steps.

(2) Etching step

(2-1) Resistor layer forming step

Next, in the multilayer substrate 20B shown in FIG. 2B, the shapes and formations are formed on the other surfaces A and B of the metal laminates 24A and 24B on the opposite side of the surface opposite to the transparent substrate 11. Resist layer corresponding to the metal wiring pattern.

In this embodiment, a conductive substrate shown in FIG. 4 and FIG. 5A is produced. A plurality of linear metal wirings 44A parallel to the Y axis are formed on one surface 11a side of the transparent base material 11 and on the other surface 11b side. A plurality of linear metal wirings 44B that are parallel to the X axis are formed. Therefore, a resist layer was formed in a shape corresponding to the metal wiring.

When the resist layer is formed, first, a photosensitive dry film resist is adhered to the surface A and the surface B of the metal laminates 24A and 24B of the multilayer substrate 20B shown in FIG. 2B by a lamination method to form a photosensitive layer. Resistor layer. Then, it is irradiated with ultraviolet rays through a mask having a wiring pattern of metal wirings formed on the photosensitive resist layer to make it photosensitive. Then, the photosensitive resist layer was brought into contact with a 1% by mass sodium carbonate aqueous solution, and a portion not irradiated with ultraviolet rays was dissolved to form a resist pattern.

(2-2) First etching step

Then, the first etching step was performed using the prepared resist layer.

In the first etching step, a first etching solution composed of 5 mass% of ferric chloride, 3 mass% of hydrochloric acid, and the remainder being ion-exchanged water was used to apply a metal laminate 24A, 24B is etched.

In the first etching step, the metal laminates 24A and 24B are etched by immersing the laminated substrate on which the resist is disposed in the first etching solution heated to 30 ° C. for 30 seconds. A transparent substrate is exposed between the metal wiring rooms.

(2-3) Washing steps

After the first etching step is completed, in order to remove the adhered first etching solution, the patterned laminate substrate is washed with flowing water in a water washing tank containing a sufficient amount of ion-exchanged water for 10 seconds. After washing with water, the attached moisture is dehydrated, dried, and supplied to the second etching step.

(2-4) Second etching step

After the water washing step was completed, the residue between the metal wirings was etched using a second etching solution composed of hydrochloric acid and ion-exchanged water and having a pH of 2.5.

In the second etching step, the patterned laminate substrate after the completion of the water washing step is immersed in the second etching solution at room temperature (23 ° C.) for 10 seconds.

(2-5) Resist removal step

After the second etching step is completed, the resist is peeled off and removed using a 4% by mass sodium hydroxide aqueous solution. After removing the resist, the obtained conductive substrate was cleaned, dehydrated, and dried again by ion-exchanged water in the same manner as in the case of the water washing step.

Regarding the conductive group obtained by performing the above steps, the visible light transmittance and b * of the transparent substrate exposed at the opening portion of the metal wiring room were evaluated. The results are shown in Table 1.

(Experimental Example 1-2, Experimental Example 1-3)

In addition to adjusting the amount of hydrochloric acid, the pH of the second etching solution used in the second etching step is adjusted. Except for the values of each experimental example shown in Table 1, a conductive substrate was produced and evaluated in the same manner as in Experimental Example 1-1. The results are shown in Table 1.

(Experimental Examples 1-4)

A conductive substrate was produced and evaluated in the same manner as in Experimental Example 1-1 except that the second etching step was not performed and only the processing up to the water washing step was performed. The results are shown in Table 1. .

(Experimental Examples 1-5, Experimental Examples 1-6)

Except that the amount of hydrochloric acid was adjusted so that the pH value of the second etching solution used in the second etching step was the value of each experimental example shown in Table 1, the other conductive materials were produced in the same manner as in Experimental Example 1-1. Substrates were evaluated. The results are shown in Table 1.

[Experimental Example 2]

The conductive substrates of Experimental Examples 2-1 to 2-5 shown below were produced and evaluated.

Experimental Examples 2-1 to 2-5 are comparative examples.

(Experimental Example 2-1 to Experimental Example 2-5)

As the second etching solution used in the second etching step, an etching solution composed of sulfuric acid and ion-exchanged water was used, and the amount of sulfuric acid added was adjusted so that the pH value of the etching solution is each experimental example shown in Table 2. The other values were evaluated in the same manner as in Experimental Example 1-1 until a conductive substrate was made. The results are shown in Table 2.

Based on the results shown in Table 1, it was confirmed that the visible light transmittance of the transparent substrate in the opening portion of the metal wiring room in Experimental Example 1-4 in which the second etching step was not performed was higher than that in the other experimental examples in which the second etching step was performed. low.

Furthermore, by comparing Experimental Examples 1-1 to 1-3, Experimental Examples 1-5, and Experimental Examples 1-6, it was confirmed that by using the second etching solution having a pH of 2.5 or less in the second etching step, The visible light transmittance of the transparent substrate between the metal wirings can be 90.0% or more. In contrast, when a second etching solution having a pH value of more than 2.5 was used, it was confirmed that the visible light transmittance was reduced to About 89%.

In addition, regarding b * of the transparent base material between metal wirings, it was confirmed that b * can be made 1.0 or less by using a second etching solution having a pH of 2.5 or less in the second etching step. In contrast, when an etching solution having a pH value of more than 2.5 was used, it was confirmed that b * of the transparent substrate between the metal wirings exceeded 1.0.

Furthermore, when comparing Experimental Example 1-1 to Experimental Example 1-3 with Experimental Example 2-1 to Experimental Example 2-5, it can be confirmed that the second etching solution can be removed by using an etching solution composed of hydrochloric acid and water. Residues in metal wiring closets. On the other hand, when an etching solution made of sulfuric acid and water was used as the second etching solution, it was confirmed that the residue could not be removed regardless of the pH value.

As mentioned above, although the conductive substrate and the manufacturing method of a conductive substrate were demonstrated by embodiment, an Example, etc., this invention is not limited to the said embodiment, Example, etc. Various modifications and changes can be made within the scope of the gist of the present invention described in the patent application scope.

This application claims priority based on Japanese Patent Application No. 2016-083180 filed with the Japan Patent Office on April 18, 2016, and refers to the entire contents of Japanese Patent Application No. 2016-083180 to this international application.

Claims (2)

A conductive substrate includes a transparent substrate, and a metal wiring formed on at least one surface of the transparent substrate. The metal wiring has a structure in which a copper wiring layer and a blackened wiring layer are laminated. The blackened wiring The layer contains nickel and copper, the visible light transmittance of the transparent substrate exposed between the metal wirings is 90% or more, and b * is 1.0 or less. A method for manufacturing a conductive substrate, comprising: an etching step: etching the metal laminate in a laminate substrate including a transparent substrate and a metal laminate to form a metal wiring, and the metal laminate is formed on At least one surface of the transparent substrate has a structure including a copper layer and a blackened layer. The blackened layer includes nickel and copper. The etching step includes: a first etching step: using Etching of one or more first etching solutions selected from iron, hydrogen peroxide water, sulfuric acid, and hydrochloric acid: a water washing step: washing the laminated substrate, and a second etching step: using hydrochloric acid and water, and The second etching solution having a pH of 2.5 or less is etched.