WO2017030026A1

WO2017030026A1 - Electroconductive substrate, and method for manufacturing electroconductive substrate

Info

Publication number: WO2017030026A1
Application number: PCT/JP2016/073145
Authority: WO
Inventors: 高塚　裕二; 山岸　浩一; 恵理子佐藤; 渡辺　宏幸
Original assignee: 住友金属鉱山株式会社
Priority date: 2015-08-20
Filing date: 2016-08-05
Publication date: 2017-02-23
Also published as: CN107924248A; CN107924248B; KR20180044891A; JP6528597B2; TWI715609B; TW201723774A; JP2017041115A; KR102601854B1

Abstract

Provided is an electroconductive substrate provided with: a transparent base material; a copper layer disposed on at least one surface side of the transparent base material; and a blackened layer disposed on at least one surface side of the transparent base material, the blackened layer containing oxygen, copper, nickel, and molybdenum. The atomic percentage of oxygen in the blackened layer is 43-60 at%, and when the total amount of the copper, nickel, and molybdenum contained in the blackened layer is defined as 100 at%, the content of the molybdenum in the blackened layer is 5 at% or more.

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.

Conventionally, a transparent conductive film for a touch panel in which an ITO (indium tin oxide) film is formed as a transparent conductive film on a polymer film has been used. (See Patent Document 1)
By the way, in recent years, a display panel with a touch panel has been increased in screen size, and in response thereto, a conductive substrate such as a transparent conductive film for a touch panel is required to have a large area. However, since ITO has a high electric resistance value, there is a problem that it cannot cope with an increase in the area of the conductive substrate.

For this reason, for example, as disclosed in Patent Documents 2 and 3, the use of a metal foil such as copper having excellent conductivity instead of the ITO film has been studied. However, for example, when copper is used for the wiring layer, since copper has a metallic luster, there is a problem that the visibility of the display decreases due to reflection.

Therefore, in order to realize improvement of both the above-described characteristics of conductivity and visibility, a conductive substrate in which a blackened layer made of a black material is formed together with a wiring layer made of a metal foil such as copper is provided. It is being considered.

Japanese Unexamined Patent Publication No. 2003-151358 Japanese Unexamined Patent Publication No. 2011-018194 Japanese Unexamined Patent Publication No. 2013-0669261

By the way, a display panel with a touch panel is often used outdoors such as a vending machine or a guidance display board.

However, the conventional blackening layer, which has been studied for use with a conductive substrate, has a problem that the environment resistance is not sufficient, discoloration occurs during long-term use, and the effect of improving visibility is reduced. In particular, a conductive substrate for a touch panel having a blackened layer formed on the surface is greatly affected by discoloration of the blackened layer, and a conductive substrate provided with a blackened layer having excellent environmental resistance has been demanded.

In view of the various problems of the prior art described above, an object of one aspect of the present invention is to provide a conductive substrate including a blackened layer having excellent environmental resistance.

In order to solve the above problems, in one aspect of the present invention,
A transparent substrate;
A copper layer disposed on at least one side of the transparent substrate;
A blackening layer disposed on at least one surface side of the transparent substrate and containing oxygen, copper, nickel and molybdenum, and
The blackening layer contains the oxygen in an amount of 43 atomic% to 60 atomic%,
Provided is a conductive substrate in which the content of molybdenum in the blackening layer is 5 atomic% or more when the total content of copper, nickel, and molybdenum in the blackening layer is 100 atomic%. .

According to one aspect of the present invention, it is possible to provide a conductive substrate including a blackened layer having excellent environmental resistance.

Sectional drawing of the electroconductive board | substrate which concerns on embodiment of this invention. Sectional drawing of the electroconductive board | substrate which concerns on embodiment of this invention. Sectional drawing of the electroconductive board | substrate which concerns on embodiment of this invention. Sectional drawing of the electroconductive board | substrate which concerns on embodiment of this invention. The top view of the electroconductive board | substrate provided with the mesh-shaped wiring which concerns on embodiment of this invention. Sectional drawing in the AA 'line of FIG. Sectional drawing in the AA 'line of FIG.

Hereinafter, an embodiment of a conductive substrate and a method for manufacturing the conductive substrate of the present invention will be described.
(Conductive substrate)
The conductive substrate of this embodiment includes a transparent base material,
A copper layer disposed on at least one surface side of the transparent substrate;
A blackening layer (hereinafter, also simply referred to as “blackening layer”) containing oxygen, copper, nickel, and molybdenum is disposed on at least one surface side of the transparent substrate. .
The blackening layer contains 43 atomic percent or more and 60 atomic percent or less of oxygen, and the total content of copper, nickel, and molybdenum in the blackening layer is 100 atomic percent. The molybdenum content is preferably 5 atomic% or more.

The conductive substrate in this embodiment is a substrate having a copper layer or a blackened layer on the surface of a transparent substrate before patterning a copper layer or the like, and a wiring shape by patterning the copper layer or blackened layer. And a wiring board.

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

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

As the insulator film that transmits visible light, for example, a polyamide film, a polyethylene terephthalate film, a polyethylene naphthalate film, a resin film such as a cycloolefin film, a polycarbonate film, or the like can be preferably used.

In particular, PET (polyethylene terephthalate), PEN (polyethylene naphthalate), COP (cycloolefin polymer), polyamide, polycarbonate, and the like can be more preferably used as a material for an insulating film that transmits visible light.

The thickness of the transparent base material is not particularly limited, and can be arbitrarily selected according to the strength, capacitance, light transmittance, and the like required for a conductive substrate.

The thickness of the transparent substrate can be, for example, 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. In the case of use for touch panel applications, for example, particularly in applications where it is required to reduce the thickness of the entire display, the thickness of the transparent substrate is preferably 20 μm or more and 50 μm or less.

Moreover, about a transparent base material, the adhesiveness with a copper layer or a blackening layer is improved, and the copper layer etc. of a transparent base material are formed from a viewpoint which prevents that the copper layer etc. which were formed on the transparent base material peel. The surface is preferably subjected to easy adhesion treatment such as disposing an easy adhesion layer.

The method for the easy adhesion treatment is not particularly limited, and any treatment that can improve the adhesion to the copper layer or the like is sufficient.

Specifically, for example, there is a method of making the surface of the transparent substrate hydrophilic by applying p-methyl methacrylate or the like on the surface on which the copper layer or the like of the transparent substrate is formed to form an easy adhesion layer. . In addition, as another method for easy adhesion treatment, a method of performing atmospheric pressure plasma treatment on the surface of the transparent substrate forming the copper layer or the like, or irradiating Ar ion on the surface of the transparent substrate forming the copper layer or the like Methods and the like.

For example, when the wettability of a PET (polyethylene terephthalate) base material surface that has not been subjected to easy adhesion treatment is evaluated by a wet tension test method, it is usually about 31 mN / m. For this reason, the adhesiveness to a copper layer etc. may not be enough.

On the other hand, for example, by irradiating the surface of the PET substrate with Ar ions for 5 to 15 minutes by sputtering and performing easy adhesion treatment, the wet tension on the surface of the PET substrate is 35 mN / m or more, for example, 40 mN. / M to 55 mN / m. For this reason, adhesiveness with a copper layer etc. can be improved especially, and it is preferable.

When the easy adhesion treatment is performed on the transparent substrate, the degree of the easy adhesion treatment is not particularly limited. However, from the viewpoint of sufficiently increasing the adhesion to the copper layer or the like, the transparent base material preferably has a wet tension of 35 mN / m or more on the surface of the transparent base on which the copper layer is disposed, for example, 40 mN. / M or more is more preferable.

The wettability of the transparent substrate can be evaluated by a wet tension test method (JIS K6768 (1999)). In addition, the surface on the side where the copper layer of the transparent substrate is disposed is not only the surface where the copper layer is directly formed on the transparent substrate, but also the copper layer via the blackening layer on the transparent substrate. Can be included.

Note that the easy adhesion treatment is not limited to the surface on the side of the transparent substrate on which the copper layer is disposed, and may be performed on the surface on which the copper layer is not disposed. However, it is preferable from the viewpoint of productivity and the like that the easy adhesion treatment is performed only on the surface on which the copper layer that is required to improve the adhesion with the copper layer or the like is disposed.

Next, the copper layer will be described.

Although not particularly limited for the copper layer, in order not to reduce the light transmittance, when placing a blackening layer between the copper layer and the transparent substrate, or between the transparent substrate and the copper layer, It is preferable not to arrange an adhesive between the copper layer and the blackening layer. That is, the copper layer is preferably formed directly on the upper surface of another member.

In order to directly form a copper layer on the upper surface of another member, the copper layer preferably has a copper thin film layer. Moreover, 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 or a blackened layer by a dry plating method to form the copper thin film layer. Thereby, a copper layer can be formed directly on a transparent base material or a blackening layer, without passing an adhesive agent.

When the copper layer is thick, the copper thin film layer is used as a power feeding layer, and a copper plating layer is formed by a wet plating method to form a copper layer having a copper thin film layer and a copper plating layer. You can also. Since the copper layer has the copper thin film layer and the copper plating layer, the copper layer can be directly formed on the transparent substrate or the blackening layer without using an adhesive.

The thickness of the copper layer is not particularly limited, and when the copper layer is used as a wiring, it can be arbitrarily selected according to the magnitude of the current supplied to the wiring, the wiring width, and the like. In particular, the thickness of the copper layer is preferably 100 nm or more, and more preferably 150 nm or more so that sufficient current can be supplied. The upper limit value of the thickness of the copper layer is not particularly limited, but if the copper layer becomes thick, side etching occurs because etching takes time when performing etching to form a wiring, and the resist peels off during the etching. Etc. are likely to occur. For this reason, it is preferable that the thickness of a copper layer is 3 micrometers or less, and it is more preferable that it is 700 nm or less.

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.

Next, the blackening layer containing oxygen, copper, nickel and molybdenum will be described.

Since the copper layer has a metallic luster, the copper reflects light as described above only by forming the wiring obtained by etching the copper layer on the transparent substrate. For example, when used as a conductive substrate for a touch panel, There was a problem that visibility was lowered. Therefore, methods for providing a blackened layer have been studied.

However, as described above, a display panel with a touch panel is often used outdoors such as a vending machine or a guidance display board. The conventional blackening layer, which has been studied for use with a conductive substrate, is not sufficiently resistant to the environment, causing problems such as discoloration when used for a long period of time and a reduction in visibility. In particular, a conductive substrate for a touch panel having a blackened layer formed on the surface is greatly affected by discoloration of the blackened layer, and a blackened layer excellent in environmental resistance has been demanded.

In addition, the environmental resistance here means a characteristic that can suppress the reflection of light on the surface of the copper layer without significant change in the color of the blackened layer even when placed in a high temperature and high humidity environment. is doing.

Accordingly, the inventors of the present invention have studied, and the layer containing oxygen, copper, nickel and molybdenum is black, so it can be used as a blackening layer, and the content of oxygen and molybdenum is within a predetermined range. As a result, it was found that high environmental resistance can be exhibited, and the present invention was completed.

The method for forming the blackened layer is not particularly limited, and the film can be formed by any method. However, since the blackening layer can be formed relatively easily, it is preferable to form the film by sputtering.

For example, the blackening layer may be a mixed sintering target of copper, nickel and molybdenum (hereinafter also referred to as “copper-nickel-molybdenum mixed sintering target”) or a molten alloy target of copper-nickel-molybdenum. A film can be formed by a sputtering method while supplying oxygen therein.

When a black / black layer deposition target is a copper / nickel / molybdenum mixed sintering target or a copper / nickel / molybdenum molten alloy target, these targets are used alone to form a blackened layer. Can be membrane.

In addition, when using a target of copper-nickel-molybdenum mixed sintering or a molten alloy target of copper-nickel-molybdenum as a target for film formation of the blackened layer, it is combined with other targets, for example, a dual simultaneous sputtering method. A blackened layer may be formed by the above. Specifically, for example, a combination of a copper-nickel-molybdenum mixed sintering target or a copper-nickel-molybdenum molten alloy target and a target containing one or more components selected from copper, nickel, and molybdenum Can also be used.

In addition, the blackening layer is formed by, for example, using a copper-nickel alloy target and a molybdenum target, or using a copper target and a nickel-molybdenum alloy target by a dual co-sputtering method while supplying oxygen into the chamber. A film can also be formed.

A configuration example of a method for manufacturing a copper-nickel-molybdenum mixed sintering target will be described. Since copper and molybdenum are difficult to melt and do not dissolve, the molybdenum / nickel ratio is 25/75 or less so that nickel and molybdenum can be dissolved in the melting method. Note that the molybdenum / nickel ratio of 25/75 or less means that when the total substance amount of molybdenum and nickel is 100, the molybdenum substance amount ratio is 25 or less.

Therefore, when the molybdenum / nickel ratio exceeds 25/75, it is preferable to prepare and use a copper-nickel-molybdenum mixed sintering target.

As a method for producing a target for copper-nickel-molybdenum mixed sintering, it is preferable to first produce a sintered body from a mixed powder of copper, nickel and molybdenum by hot pressing or hot isostatic pressing (HIP). . The obtained sintered body is processed into a predetermined shape, and then attached to a backing plate to be a target for copper-nickel-molybdenum mixed sintering.

The sintering temperature when producing a sintered body from a mixed powder of copper, nickel and molybdenum is preferably 850 ° C. or higher and 1083 ° C. or lower, more preferably 950 ° C. or higher and 1050 ° C. or lower.

This is because the sintering does not proceed sufficiently at a temperature lower than 850 ° C., so the density of the sintered body is low, and there is a problem that cooling water may remain in the pores of the sintered body in the planar processing to be targeted. . Moreover, when it exceeds 1083 degreeC, since it exceeds melting | fusing point of copper, since copper flows out, it is unpreferable.

Note that the method of manufacturing a target for mixed sintering of copper-nickel-molybdenum is not limited to the above-described manufacturing method, and is not particularly limited as long as it can be manufactured so as to be a target having a desired composition. And can be used.

The oxygen content in the gas supplied into the chamber during sputtering is not particularly limited. The amount of oxygen taken into the blackened layer varies depending on the growth rate (deposition rate) of the blackened layer, and the oxygen content in the gas supplied into the chamber affects the growth rate of the blackened layer. For this reason, it is preferable to arbitrarily select the content ratio of oxygen in the gas supplied into the chamber during sputtering according to the composition of the target blackening layer and the growth rate of the blackening layer.

The growth rate of the blackened layer is not particularly limited, but it is preferable to set it to about 4 nm / min or more and 20 nm / min or less in consideration of productivity and the like.

Then, in order to form a blackened layer at such a growth rate to obtain a blackened layer containing a desired amount of oxygen, a gas having an oxygen content of 25% by volume to 55% by volume is supplied to the chamber. However, it is preferable to form a blackened layer. The content ratio of oxygen in the gas supplied to the chamber is more preferably 30% by volume or more and 45% by volume or less.

In addition, the oxygen partial pressure in the chamber when forming the blackened layer is preferably 0.1 Pa or more, and more preferably 0.15 Pa or more.

As described above, by setting the content ratio of oxygen in the gas supplied to the chamber to 25% by volume or more, the blackened layer can be sufficiently oxidized, and discoloration of the blackened layer due to atmospheric oxygen or moisture can be prevented. This is preferable because it can be prevented and environmental resistance can be improved. The oxygen content in the gas supplied into the chamber is more preferably 30% by volume or more.

However, if the oxygen content in the gas supplied into the chamber exceeds 55% by volume, the growth rate of the blackened layer is slow, which is not preferable. For this reason, as described above, the oxygen content in the gas supplied into the chamber is preferably 55% by volume or less. In particular, the content ratio of oxygen in the gas supplied into the chamber is more preferably 45% by volume or less from the viewpoint of maintaining a high growth rate of the blackened layer and increasing productivity.

In addition, when performing sputtering, the gas supplied into the chamber is preferably an inert gas for the remainder other than oxygen. For the remainder other than oxygen, for example, one or more gases selected from argon, xenon, neon, and helium can be supplied.

The composition of the target used for sputtering is not particularly limited, and can be arbitrarily selected according to the composition of the blackening layer to be formed. Note that the easiness of element flight from the target during sputtering varies depending on the type of element. For this reason, the composition of a target can be selected according to the composition of the target blackening layer, and the easiness of the element in a target to fly.

As described above, for example, a copper-nickel-molybdenum mixed sintering target can be used as a target used for sputtering. In this case, the composition of the target is not particularly limited as described above, but the target of the mixed sintering of copper-nickel-molybdenum preferably contains molybdenum at a ratio of 5 atomic% to 75 atomic%, preferably 7 atomic%. More preferably, it is contained at a ratio of 65 atomic% or less. Nickel is preferably 10 atomic percent or more and 50 atomic percent or less. In these cases, the balance can be made of copper.

As described above, the formed blackened layer can contain oxygen, copper, nickel, and molybdenum. Although the content ratio of each component in the blackened layer is not particularly limited, the total content of copper, nickel, and molybdenum in the blackened layer, that is, the total content of metal elements contained in the blackened layer is 100 atoms. %, The molybdenum content is preferably 5 atomic% or more. That is, the content ratio of molybdenum in the metal element contained in the blackened layer is preferably 5 atomic% or more.

This is because the reflectance of light on the surface of the blackened layer can be particularly lowered by setting the content ratio of molybdenum in the metal element contained in the blackened layer to 5 atomic% or more. In addition, by setting the content of molybdenum in the metal element contained in the blackened layer to 5 atomic% or more, the amount of oxygen taken into the blackened layer can be increased, and the environmental resistance can be improved. become.

However, if the molybdenum content in the metal element contained in the blackened layer is too high, the reactivity of the blackened layer to the etching solution is lowered, and it may be difficult to form a desired wiring pattern. . Therefore, the content of molybdenum in the blackened layer when the total content of copper, nickel, and molybdenum in the blackened layer is 100 atomic%, that is, the molybdenum content in the metal element contained in the blackened layer. The content ratio is preferably 40 atomic% or less.

Further, when the total content of copper, nickel and molybdenum in the blackened layer, that is, the total content of metal elements contained in the blackened layer is 100 atomic%, the content of copper in the blackened layer Is preferably 30 atomic% or more and 70 atomic% or less. That is, the content ratio of copper in the metal element contained in the blackened layer is preferably 30 atomic% or more and 70 atomic% or less. The content ratio of copper in the metal element contained in the blackened layer is more preferably 40 atom% or more and 60 atom% or less.

This is because if the copper content in the metal element contained in the blackened layer is less than 30 atomic%, the etching property may deteriorate. Moreover, it is because environmental resistance may fall when the content rate of copper in the metal element contained in a blackening layer exceeds 70 atomic%.

Furthermore, when the total content of copper, nickel and molybdenum in the blackened layer, that is, the total content of metal elements contained in the blackened layer is 100 atomic%, the content of nickel in the blackened layer Is preferably 15 atomic% or more and 65 atomic% or less. That is, the content ratio of nickel in the metal element contained in the blackened layer is preferably 15 atomic% or more and 65 atomic% or less. The content ratio of nickel in the metal element contained in the blackened layer is more preferably 25 atomic% or more and 55 atomic% or less.

This is because if the nickel content in the metal element contained in the blackened layer is less than 15 atomic%, the environmental resistance may deteriorate. Moreover, it is because etching property may worsen when the content rate of nickel in the metal element contained in the blackened layer exceeds 65 atomic%.

Further, the oxygen contained in the blackened layer is preferably 43 atom% or more and 60 atom% or less, and more preferably 45 atom% or more and 55 atom% or less.

This is because the blackening layer is sufficiently oxidized by containing 43 atomic% or more of oxygen, and can be maintained sufficiently black without being oxidized by oxygen or moisture in the atmosphere. This is because the environmental resistance can be improved. Further, when the oxygen content in the blackened layer exceeds 60 atomic%, the blackened layer becomes transparent and the reflection of the copper film on the short wavelength side shorter than 600 nm increases, so that the blackened layer has no sheet resistance. Since it becomes high, it is preferable that it is 60 atomic% or less.

In the formed blackening layer, oxygen, copper, nickel and molybdenum may be contained in any form. For example, copper and molybdenum may form a mixed sintered body, and a copper-molybdenum mixed sintered body containing oxygen may be contained in the blackened layer. Further, copper, nickel or molybdenum is, for example, copper oxide (Cu ₂ O, CuO, Cu ₂ O ₃ ), nickel oxide (NiO), molybdenum oxide (MoO ₃ , MoO ₂ , Mo ₂ O ₃ ), copper-molybdenum oxide. One or more types selected from the products (CuMoO ₄ , Cu ₂ MoO _5, Cu ₆ Mo ₄ O ₁₅ , Cu ₃ Mo ₂ O ₉ , Cu ₂ Mo ₃ O ₁₀ , Cu ₄ Mo ₃ O _12, etc.) It may be contained in the blackening layer.

The blackening layer may be a layer composed of only one kind of substance containing oxygen, copper, nickel and molybdenum simultaneously, such as a copper-nickel-molybdenum mixture containing oxygen. Further, for example, it contains one or more kinds of substances selected from the above-mentioned copper-molybdenum mixed sintered body containing oxygen, copper oxide, nickel oxide, molybdenum oxide, copper-molybdenum oxide, etc. It may be a layer.

The thickness of the blackening layer is not particularly limited, but is preferably 20 nm or more, for example, and more preferably 25 nm or more. The blackening layer is black as described above and functions as a blackening layer that suppresses reflection of light by the copper layer. However, when the thickness of the blackening layer is thin, sufficient blackness is obtained. In some cases, reflection of light by the copper layer cannot be sufficiently suppressed. On the other hand, since the reflection of a copper layer can be suppressed more by making the thickness of a blackening layer into the said range, it is preferable.

The upper limit of the thickness of the blackened layer is not particularly limited, but when the thickness of the blackened layer is increased, the reflectance, lightness (L ^* ), and chromaticity (a ^* , b ^* ) of the optical characteristics are increased. May be inferior in characteristics as a blackened layer, which is not preferable. For this reason, the thickness of the blackened layer is preferably 45 nm or less, and more preferably 40 nm or less.

Further, when the sheet resistance of the blackened layer is sufficiently small, a contact portion with an electric member such as a wiring can be formed on the blackened layer, and the copper layer is exposed even when the blackened layer is located on the outermost surface. This is preferable because it is unnecessary.

In order to form a contact portion with an electric member such as a wiring in the blackened layer, the sheet resistance of the blackened layer is preferably less than 1 kΩ / □.

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

As described above, the conductive substrate of this embodiment includes a transparent substrate, a copper layer, and a blackening layer containing oxygen, copper, nickel, and molybdenum. Under the present circumstances, the order of lamination | stacking at the time of arrange | positioning a copper layer and a blackening layer on a transparent base material is not specifically limited. Further, a plurality of copper layers and blackening layers can be formed. In order to suppress the reflection of light on the surface of the copper layer, it is preferable that the blackening layer is disposed on the surface of the copper layer on which the reflection of light is particularly desired to be suppressed. More preferably, the copper layer has a structure sandwiched between blackening layers.

Furthermore, when a blackening layer having a low sheet resistance is included as described above, the blackening layer having a low sheet resistance is preferably disposed on the outermost surface of the conductive substrate. This is because the blackened layer having a low sheet resistance can be connected to an electric member such as a wiring, and is preferably disposed on the outermost surface of the conductive substrate so as to be easily connected.

Specific configuration examples will be described below with reference to FIGS. 1A, 1B, 2A, and 2B. 1 and 2 show examples of cross-sectional views of the conductive substrate of this embodiment on a plane parallel to the lamination direction of the transparent base material, the copper layer, and the blackening layer.

For example, like the conductive substrate 10A shown in FIG. 1A, the copper layer 12 and the blackened layer 13 can be laminated one layer at a time on the one surface 11a side of the transparent substrate 11. Moreover, like the electroconductive board | substrate 10B shown to FIG. 1B,

copper layer

12A, 12B and black layer are respectively provided in the one surface 11a side of the transparent base material 11, and the other surface (other surface) 11b side. The

layers

13A and 13B can be stacked one by one in that order. The order in which the copper layer 12 (12A, 12B) and the blackened layer 13 (13A, 13B) are stacked is not limited to the example of FIGS. 1A and 1B, and the blackened layer 13 ( 13A, 13B) and the copper layer 12 (12A, 12B) can be laminated in this order.

Further, for example, a configuration in which a plurality of blackening layers are provided on the one surface 11a side of the transparent substrate 11 may be employed. For example, like the conductive substrate 20A shown in FIG. 2A, the first blackened layer 131, the copper layer 12, and the second blackened layer 132 are formed on one surface 11a side of the transparent base material 11. They can be stacked in that order.

In this case as well, a configuration in which a copper layer, a first blackened layer, and a second blackened layer are laminated on both surfaces of the transparent substrate 11 can be adopted. Specifically, like the conductive substrate 20B shown in FIG. 2B, the first blackening layer is formed on one surface 11a side of the transparent base material 11 and on the other surface (the other surface) 11b side. 131A, 131B, copper layers 12A, 12B, and second blackening layers 132A, 132B can be stacked in that order.

In FIG. 1B and FIG. 2B, when a copper layer and a blackening layer are laminated on both sides of a transparent substrate, the layers laminated on the upper and lower sides of the transparent substrate 11 are symmetrical with the transparent substrate 11 as a symmetry plane. Although the example which arranged in this way was shown, it is not limited to the form which concerns. For example, in FIG. 2B, the configuration on the one surface 11a side of the transparent base material 11 is a form in which a copper layer 12 and a blackening layer 13 are laminated in that order, similarly to the configuration of FIG. The layers stacked above and below may be asymmetrical.

In addition, when forming a copper layer etc. in the one surface 11a side of the transparent base material 11 like FIG. 1A and FIG. 2A, it is easy adhesiveness about the one surface 11a of the transparent base material 11 as already stated. It is preferable to perform the treatment. Moreover, when forming a copper layer etc. in the one surface 11a side of the transparent base material 11 and the other surface 11b side like FIG. 1B and FIG. 2B, about both surfaces of the one surface 11a and the other surface 11b It is preferable to perform easy adhesion treatment.

Up to this point, the conductive substrate of the present embodiment has been described. However, in the conductive substrate of the present embodiment, the copper layer and the blackened layer are provided on the transparent base material. Reflection can be suppressed.

The degree of light reflection of the conductive substrate of this embodiment is not particularly limited. For example, the conductive substrate of this embodiment preferably has a light reflectance of 550 nm of 30% or less, and 20% or less. More preferably, it is more preferably 10% or less.

In the conductive substrate of this embodiment, the average visible light reflectance, which is the average reflectance of light having a wavelength in the range of 350 nm to 780 nm, is preferably 30% or less, and preferably 20% or less. More preferably, it is 10% or less.

In addition, the average value of the reflectance (visible light average reflectance) with respect to light in the wavelength range of 350 nm or more and 780 nm or less is such that light in the wavelength range of 350 nm or more and 780 nm or less is changed at a predetermined interval, for example, 1 nm interval, It means the average value when the reflectance is measured by irradiating the blackened layer.

This is because, when at least one of the reflectance of light having a wavelength of 550 nm and the average reflectance of visible light is 30% or less, for example, even when used as a conductive substrate for a touch panel, the visibility of the display is hardly lowered. is there. From the viewpoint of particularly suppressing the deterioration of the visibility of the display, both the reflectance of light having a wavelength of 550 nm and the average reflectance of visible light are more preferably 30% or less.

The reflectance can be measured by irradiating the blackened layer with light. That is, measurement can be performed from the blackened layer side of the copper layer and the blackened layer included in the conductive substrate.

Specifically, for example, as shown in FIG. 1A, when the copper layer 12 and the blackened layer 13 are laminated in this order on one surface 11 a of the transparent substrate 11, the blackened layer 13 can be irradiated with light. Can be measured by irradiating the surface A with light.

Further, when the arrangement of the copper layer 12 and the blackened layer 13 is changed from that in the case of FIG. 1A and the blackened layer 13 and the copper layer 12 are laminated in this order on one surface 11a of the transparent base material 11, the transparent base material 11 is The reflectance can be measured by irradiating the surface of the blackened layer 13 with light from the surface 11b side of the transparent substrate 11, which is the side where the blackened layer 13 is located on the outermost surface.

As will be described later, the conductive substrate can form wiring by etching the copper layer and the blackened layer, but the reflectance is arranged on the outermost surface when the transparent substrate is removed from the conductive substrate. The reflectance of the blackened layer on the surface on the light incident side is shown. For this reason, if it is before an etching process or after performing an etching process, it is preferable that the measured value in the part in which the copper layer and the blackening layer remain satisfy | fills the said range.

Further, lightness (L ^* ) and chromaticity (a ^* , b ^* ) can be calculated from the measured reflectance. The lightness (L ^* ) and chromaticity (a ^* , b ^* ) are not particularly limited, but the lightness (L ^* ) is preferably 60 or less, and more preferably 55 or less. Further, at least one of the chromaticities (a ^* , b ^* ) is preferably less than 0, that is, negative, and more preferably, both a ^* and b ^* are less than 0.

This is because when the lightness (L ^* ) is 60 or less, the color tone becomes dark, so that reflection of light can be particularly suppressed. Further, when at least one of the chromaticities (a ^* , b ^* ) is less than 0, the blackened layer becomes a color particularly suitable for suppressing light reflection.

The conductive substrate of this embodiment can be preferably used as a conductive substrate for a touch panel, for example, as described above. 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 so far.

For example, a mesh-like wiring can be formed by two-layer wiring. A specific configuration example is shown in FIG. FIG. 3 shows a view of the conductive substrate 30 provided with the mesh-like wiring as viewed from the upper surface side in the stacking direction of the copper layer and the blackening layer, and also shows the wiring 31B visible through the transparent substrate 11. . The conductive substrate 30 shown in FIG. 3 has a transparent base material 11, a plurality of wirings 31A parallel to the Y-axis direction in the drawing, and wirings 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 and / or the lower surface of the

wirings

31A and 31B. The blackened layer is etched so as to have the same pattern 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 are cross-sectional views taken along line AA ′ of FIG.

First, as shown in FIG. 4A, wirings 31A and 31B may be arranged on the upper and lower surfaces of the transparent base material 11, respectively. In this case, blackening

layers

32A and 32B etched in the same shape as the wiring are disposed on the upper surfaces of the

wirings

31A and 31B.

Further, as shown in FIG. 4B, a pair of

transparent base materials

11A and 11B are used, and

wirings

31A and 31B are arranged on the upper and lower surfaces with one transparent base material 11A interposed therebetween, and one wiring 31B is transparent. You may arrange | position between 11 A of base materials and the transparent base material 11B. Also in this case, blackened

layers

wirings

31A and 31B. As described above, the arrangement of the blackened layer and the copper layer is not limited. Therefore, the arrangement of the blackening layers 32A and 32B and the

wirings

31A and 31B can be reversed in either case of FIG. 4A or FIG. 4B. For example, a plurality of blackening layers can be provided.

However, the blackened layer is preferably disposed on the surface of the copper layer surface where light reflection is particularly desired to be suppressed.

For this reason, for example, in the conductive substrate shown in FIG. 4A, the positions of the wiring 31A and the blackened layer 32A and / or the wiring 31B and the blackened layer 32B can be reversed. Further, a blackening layer may be further provided between the wiring 31 </ b> A and the transparent base material 11 and / or between the wiring 31 </ b> B and the transparent base material 11.

In the case of the conductive substrate shown in FIG. 4B, for example, when it is necessary to suppress the reflection of light from the lower surface side in the drawing, the positions of the blackening layers 32A and 32B, the wiring 31A, It is preferable to reverse the positions of 31B. Further, in addition to the blackening layers 32A and 32B, a blackening layer may be further provided between the wiring 31A and the transparent base material 11A and / or between the wiring 31B and the transparent base material 11B.

4A and 4B as described above, when a blackening layer is further provided, the blackening layer further provided is patterned so as to have the same pattern as the wiring in contact with the blackening layer. It is preferable.

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

copper layers

12A and 12B and blackening

layers

13A and 13B (131A) on both surfaces of the transparent base 11 as shown in FIGS. 1B and 2B. 132A, 131B, 132B).

A case where the conductive substrate of FIG. 1B is used will be described as an example. First, the copper layer 12A and the blackened layer 13A on the one surface 11a side of the transparent base material 11 are parallel to the Y-axis direction in FIG. 1B. Etching is performed so that a plurality of linear patterns are arranged at predetermined intervals along the X-axis direction. The Y-axis direction in FIG. 1B means a direction perpendicular to the paper surface in FIG. 1B.

Then, the copper layer 12B and the blackening layer 13B on the other surface 11b side of the transparent substrate 11 are arranged such that a plurality of linear patterns parallel to the X-axis direction in FIG. Etching is performed. Note that the X-axis direction in FIG. 1B means a direction parallel to the width direction of each layer included in the conductive substrate 10B shown in FIG. 1B.

By the above operation, the conductive substrate having the mesh-like wiring shown in FIGS. 3 and 4A can be formed. Note that the etching of both surfaces of the transparent substrate 11 can 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.

In addition, when a conductive substrate having mesh-like wiring is similarly formed using the conductive substrate 20B shown in FIG. 2B, the wiring between the

wirings

31A and 31B and the transparent substrate 11 in FIG. A blackened layer patterned so as to have the same pattern as 31A and 31B is disposed.

3 can also be formed by using two conductive substrates shown in FIG. 1A or FIG. 2A. The case where the conductive substrate of FIG. 1A is used will be described as an example. For the two conductive substrates shown in FIG. 1A, the copper layer 12 and the blackened layer 13 are respectively formed in a plurality of linear shapes parallel to the X-axis direction. Etching is performed so that the patterns are arranged at predetermined intervals in the Y-axis direction. Then, the conductive substrate having mesh-like wiring is obtained by bonding the two conductive substrates so that the linear patterns formed on the respective conductive substrates intersect with each other by the etching process. be able to. The surface to be bonded when two conductive substrates are bonded is not particularly limited, and the surface A in FIG. 1A in which the copper layer 12 or the like is stacked as shown in FIG. 4B and the copper layer 12 or the like are stacked. The surface 11b in FIG. 1A that is not present may be bonded.

In addition, it is preferable that the blackening layer is disposed on the surface of the copper layer surface where light reflection is particularly desired to be suppressed. Therefore, in the conductive substrate shown in FIG. 4B, when it is necessary to suppress the reflection of light from the lower surface side in the figure, the positions of the blackening layers 32A and 32B and the positions of the

wirings

31A and 31B are set. It is preferable to arrange them in reverse. Further, in addition to the blackening layers 32A and 32B, a blackening layer may be further provided between the wiring 31A and the transparent base material 11A and / or between the wiring 31B and the transparent base material 11B.

Further, for example, the surfaces 11b in FIG. 1A where the copper layer 12 or the like of the transparent substrate 11 is not laminated may be bonded together so that the cross section has the structure shown in FIG. 4A.

In addition, the width of the wiring in the conductive substrate having the mesh-like wiring shown in FIGS. 3, 4A, and 4B, and the distance between the wirings are not particularly limited. Can be selected accordingly.

3, 4 </ b> A, and 4 </ b> B show examples in which a mesh-like wiring (wiring pattern) is formed by combining linear wirings, but the present invention is not limited to such a form. The wiring that constitutes can be of any shape. For example, the shape of the wiring constituting the mesh-like wiring pattern can be changed to various shapes such as jagged lines (zigzag straight lines) so that moire (interference fringes) does not occur between the images on the display.

Thus, a conductive substrate having a mesh-like wiring composed of two layers of wiring can be preferably used as a conductive substrate for a projected capacitive touch panel, for example.
(Method for producing conductive substrate)
Next, a configuration example of the method for manufacturing the conductive substrate according to the present embodiment will be described.

The manufacturing method of the conductive substrate of this embodiment is as follows:
A transparent substrate preparation step of preparing a transparent substrate;
A copper layer forming step of forming a copper layer on at least one surface side of the transparent substrate;
A blackening layer forming step of forming a blackening layer containing oxygen, copper, nickel and molybdenum on at least one surface side of the transparent substrate.
The blackening layer contains 43 atomic percent or more and 60 atomic percent or less of oxygen, and the total content of copper, nickel, and molybdenum in the blackening layer is 100 atomic percent. The molybdenum content is preferably 5 atomic% or more.

Hereinafter, the manufacturing method of the conductive substrate according to the present embodiment will be described. However, since the configuration can be the same as that of the conductive substrate described above except for the points described below, a part of the description will be omitted.

As described above, in the conductive substrate of the present embodiment, the order of stacking when the copper layer and the blackened layer are disposed on the transparent base material is not particularly limited. Further, a plurality of copper layers and blackening layers can be formed. For this reason, the order of the copper layer forming step and the blackened layer forming step and the number of times of execution are not particularly limited, and are performed at an arbitrary number of times according to the structure of the conductive substrate to be formed. be able to.

The transparent substrate preparation step for preparing a transparent substrate is a step of preparing a transparent substrate composed of, for example, an insulating film that transmits visible light, a glass substrate, or the like, and the specific operations are particularly limited. It is not a thing. For example, in order to use for each process of a back | latter stage, it can cut | disconnect etc. to arbitrary sizes as needed.

Note that since a film that can be particularly suitably used as an insulating film that transmits visible light has already been described, description thereof is omitted here.

In addition, for the transparent substrate, from the viewpoint of enhancing the adhesion with the copper layer or the blackened layer and preventing the copper layer or the like formed on the transparent substrate from peeling off, in the transparent substrate preparation step, the transparent substrate Of these, it is preferable to perform easy adhesion treatment on the surface on which the copper layer is formed (easy adhesion treatment step).

Specifically, for example, there is a method of making the surface of the transparent substrate hydrophilic by applying p-methyl methacrylate or the like on the surface on which the copper layer or the like of the transparent substrate is formed to form an easy adhesion layer. .

In addition, as another method for easy adhesion treatment, a method of performing atmospheric pressure plasma treatment on the surface of the transparent substrate forming the copper layer or the like, or irradiating Ar ion on the surface of the transparent substrate forming the copper layer or the like Methods and the like.

Although it does not specifically limit about the grade which performs an easily-adhesive process, For example, it is preferable that the wetting tension of the surface at the side which forms the copper layer of a transparent base material is 35 mN / m or more, and is 40 mN / m or more. More preferably.

The wettability of the transparent substrate can be evaluated by a wet tension test method (JIS K6768 (1999)).

In addition, the surface on the side where the copper layer of the transparent substrate is formed is not only the surface on which the copper layer is directly formed on the transparent substrate, but also the copper layer on the transparent substrate via the blackening layer. The surface to be formed can be included.

Further, the easy adhesion treatment is not limited to the surface on the side of forming the copper layer of the transparent substrate, and may be performed on the surface on which the copper layer is not disposed. However, it is preferable from the viewpoint of productivity and the like that the easy adhesion treatment is performed only on the surface on the side where the copper layer that is required to improve the adhesion with the copper layer or the like is required.

Next, the copper layer forming process will be described.

As described above, the copper layer preferably has a copper thin film layer. Moreover, it can also have a copper thin film layer and a copper plating layer. For this reason, a copper layer formation process can have a copper thin film layer formation process which forms a copper thin film layer, for example with a dry-type plating method. The copper layer forming step includes a copper thin film layer forming step for forming a copper thin film layer by a dry plating method, and a copper plating layer forming step for forming a copper plating layer by a wet plating method using the copper thin film layer as a power feeding layer. , May be included.

The dry plating method used for forming the copper thin film layer is not particularly limited, and for example, a vacuum deposition method, a sputtering method, an ion plating method, or the like can be used. In particular, as the dry plating method used for forming the copper thin film layer, it is more preferable to use the sputtering method because the film thickness can be easily controlled.

The process of forming a copper thin film layer will be described taking the case of using a winding type sputtering apparatus as an example. First, a copper target is mounted on a sputtering cathode, and a base material, specifically a transparent base material, a transparent base material with a blackened layer, or the like is set in a vacuum chamber. After evacuating the inside of the vacuum chamber, Ar gas is introduced to maintain the inside of the apparatus at about 0.13 Pa to 1.3 Pa. In this state, the substrate is conveyed from the unwinding roll at a speed of, for example, about 1 to 20 m / min, and power is supplied from the sputtering direct current power source connected to the cathode, and sputtering discharge is performed. The copper thin film layer can be continuously formed.

In addition, the specific operation method in a copper thin film layer formation process is not specifically limited, It can implement by arbitrary methods and operation.

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 according to ordinary methods may be adopted. For example, a copper plating layer can be formed by supplying a base material on which a copper thin film layer is formed in a plating tank containing a copper plating solution and controlling the current density and the conveyance speed of the base material.

The thickness of the copper layer formed in the copper layer forming step is not particularly limited, but as described above for the conductive substrate, the copper layer preferably has a thickness of 100 nm or more, and is 150 nm or more. It is more preferable. The upper limit value of the thickness of the copper layer is not particularly limited, but is preferably 3 μm or less, and more preferably 700 nm or less.

Next, the blackening layer forming process will be described.

The blackening layer forming step is not particularly limited, but as described above, the blackening layer can be formed by sputtering.

In this case, as the target, for example, a copper-nickel-molybdenum mixed sintered target or a copper-nickel-molybdenum molten alloy target can be used.

As described above, a copper-nickel-molybdenum mixed sintering target or a copper-nickel-molybdenum molten alloy target can be used alone, but one or more selected from copper, nickel, and molybdenum can be used. It can also be used in combination with a target containing a component.

Further, as described above, the film can be formed by a binary simultaneous sputtering method using a copper-nickel alloy target and a molybdenum target, or using a copper target and a nickel-molybdenum alloy target.

The composition of the target used for sputtering is not particularly limited, and can be arbitrarily selected according to the composition of the blackened layer to be formed. Note that the easiness of element flight from the target during sputtering varies depending on the type of element. For this reason, the composition of a target can be selected according to the composition of the target blackening layer, and the easiness of the element in a target to fly.

For example, a copper-nickel-molybdenum mixed sintering target preferably contains molybdenum in a proportion of 5 atomic percent to 75 atomic percent and nickel in a proportion of 10 atomic percent to 50 atomic percent. Moreover, it is more preferable to contain molybdenum at a ratio of 7 atomic% to 65 atomic%. The remainder can be made of copper.

Further, when forming the blackened layer by sputtering, the blackened layer can be formed while supplying a gas containing oxygen into the chamber. The supply ratio of oxygen in the gas supplied into the chamber is not particularly limited, and the ratio of oxygen in the gas supplied into the chamber during sputtering depends on the composition of the target blackening layer and the growth rate of the blackening layer. It is preferable to arbitrarily select the oxygen content.

When forming the blackening layer, the oxygen content in the gas supplied into the chamber is preferably 25% by volume to 55% by volume, more preferably 30% by volume to 45% by volume. preferable.

As described above, in the blackening layer forming step, for example, a copper-nickel-molybdenum mixed sintered target can be used. Therefore, in the blackening layer forming step, for example, a copper-nickel-molybdenum mixed sintered target is used, and a sputtering method is performed while supplying a gas containing oxygen in a ratio of 25 volume% to 55 volume% in the chamber. A blackening layer can be formed.

In addition, when performing sputtering, the gas supplied into the chamber is preferably an inert gas for the remainder other than oxygen. For the remainder other than oxygen, for example, one or more selected from argon, xenon, neon, and helium can be supplied.

The formed blackening layer can contain oxygen, copper, nickel and molybdenum. The content ratio of each component in the blackened layer is not particularly limited, but the total content of copper, nickel and molybdenum in the blackened layer, that is, the total content of metal elements contained in the blackened layer When the content is 100 atomic%, the molybdenum content is preferably 5 atomic% or more. That is, the content ratio of molybdenum in the metal element contained in the blackened layer is preferably 5 atomic% or more.

This is because the reflectance of light on the surface of the blackened layer can be particularly lowered by setting the content ratio of molybdenum in the metal element contained in the blackened layer to 5 atomic% or more. In addition, by setting the content of molybdenum in the metal element contained in the blackened layer to 5 atomic% or more, the amount of oxygen taken into the blackened layer can be increased, and the environmental resistance can be improved. Because it becomes.

However, if the molybdenum content in the metal element contained in the blackened layer is too high, the reactivity of the blackened layer to the etching solution is lowered, and it may be difficult to form a desired wiring pattern. . Therefore, when the total content of copper, nickel, and molybdenum in the blackened layer is 100 atomic%, the molybdenum content in the blackened layer, that is, molybdenum in the metal element contained in the blackened layer The content ratio of is preferably 40 atomic% or less.

In addition, when the total content of copper, nickel, and molybdenum in the blackened layer, that is, the total content of metal elements contained in the blackened layer is 100 atomic%, the content of copper in the blackened layer The amount is preferably 30 atomic% or more and 70 atomic% or less. That is, the content ratio of copper in the metal element contained in the blackened layer is preferably 30 atomic% or more and 70 atomic% or less. The content ratio of copper in the metal element contained in the blackened layer is more preferably 40 atom% or more and 60 atom% or less.

When the formed blackened layer has a sufficiently low sheet resistance, a contact portion with an electric member such as a wiring can be formed on the blackened layer, and the copper layer is formed even when the blackened layer is located on the outermost surface. This is preferable because it is not necessary to expose.

The thickness of the blackened layer formed in the blackened layer forming step is not particularly limited, but as described above for the conductive substrate, for example, preferably 20 nm or more, more preferably 25 nm or more. preferable. The upper limit value of the thickness of the blackening layer is not particularly limited, but is preferably 45 nm or less, and more preferably 40 nm or less.

And the conductive substrate obtained by the manufacturing method of the conductive substrate demonstrated here can be made into the conductive substrate provided with the mesh-shaped wiring. In this case, in addition to the above-described steps, an etching step of forming a wiring by etching the copper layer and the blackening layer can be further included.

In this etching step, for example, first, a resist having an opening corresponding to a portion to be removed by etching is formed on the outermost surface of the conductive substrate. In the case of the conductive substrate shown in FIG. 1A, a resist can be formed on the exposed surface A of the blackening layer 13 disposed on the conductive substrate. Note that a method for forming a resist having an opening corresponding to a portion to be removed by etching is not particularly limited. For example, the resist can be formed by a photolithography method.

Next, the copper layer 12 and the blackened layer 13 can be etched by supplying an etching solution from the upper surface of the resist.

In addition, when a copper layer and a blackening layer are disposed on both surfaces of the transparent substrate 11 as shown in FIG. 1B, a resist having openings of predetermined shapes is formed on the surfaces A and B of the conductive substrate, You may etch the copper layer and blackening layer which were formed in both surfaces of the transparent base material 11 simultaneously.

In addition, the copper layer and the blackened layer formed on both sides of the transparent substrate 11 can be subjected to an etching process on one side. That is, for example, after the copper layer 12A and the blackened layer 13A are etched, the copper layer 12B and the blackened layer 13B can be etched.

The blackened layer formed by the method for manufacturing a conductive substrate according to the present embodiment exhibits almost the same reactivity to the etching solution as the copper layer. For this reason, the etching liquid used in an etching process is not specifically limited, The etching liquid generally used for the etching of a copper layer can be used preferably. As the etching solution, for example, a mixed aqueous solution of ferric chloride and hydrochloric acid can be used more preferably. The contents of ferric chloride and hydrochloric acid in the etching solution are not particularly limited. For example, ferric chloride is preferably contained in a proportion of 5% by mass to 50% by mass, and 10% by mass. More preferably, it is contained at a ratio of 30% by mass or less. Further, for example, the etching solution preferably contains hydrochloric acid in a proportion of 1% by mass or more and 50% by mass or less, and more preferably contains 1% by mass or more and 20% by mass or less. The remainder can be water.

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

Since the specific form of the mesh-like wiring obtained by the above-described etching process is as described above, the description thereof is omitted here.

In addition, as described above, two conductive substrates having a copper layer and a blackened layer were bonded to one surface side of the transparent base material 11 shown in FIGS. 1A and 2A to provide a mesh-like wiring. In the case of using a conductive substrate, a step of bonding the conductive substrate can be further provided. At this time, a method for bonding the two conductive substrates is not particularly limited, and the bonding can be performed using, for example, an adhesive.

The conductive substrate and the method for manufacturing the conductive substrate of the present embodiment have been described above. Such a conductive substrate includes a blackened layer having excellent environmental resistance. For this reason, discoloration of the blackened layer can be suppressed even in an environment exposed to high temperature and high humidity such as outdoors, and the effect of improving the visibility by the blackened layer can be maintained. Become.

Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples of the present invention, but the present invention is not limited to these examples.

First, the evaluation method of the sample produced in each experiment example mentioned later is demonstrated.
(Evaluation methods)
(1) Optical characteristics (reflectance, brightness, chromaticity)
The conductive substrate produced in the following experimental example was measured for optical characteristics (reflectance), and the lightness (L ^* ) and chromaticity (a ^* , b ^* ) were determined from the measured optical characteristics (reflectance) as necessary ^. ) Was calculated.

The reflectance was measured by installing a reflectance measurement unit in an ultraviolet-visible spectrophotometer (manufactured by Hitachi High-Technologies Corporation, model: U-4000).

In Experimental Example 2 below, a conductive substrate having a cross-sectional shape similar to that shown in FIG. 1A was produced. Therefore, the surface A in FIG. 1A on the side where the copper layer and the blackening layer of the conductive substrate are formed is irradiated with light in the wavelength range of 350 nm to 780 nm with an incident angle of 5 ° and a light receiving angle of 5 °. The reflectivity when measured was measured. In the measurement, light having a wavelength changed every 1 nm was irradiated in a wavelength range of 350 nm or more and 780 nm or more, and the reflectance for each wavelength was measured.

And the measured value of the reflectance with respect to the light with a wavelength of 550 nm was defined as the reflectance with respect to the light with a wavelength of 550 nm.

In the measurement, in order to correct the warp of the PET film, the sample of each experimental example was placed on a glass substrate, fixed with a clamp, and measured by irradiating light from the blackened layer side.

Calculate coordinates in the CIE 1976 (L ^* , a ^* , b ^* ) color space from the measured reflectance using a color calculation program based on JIS Z8781-4: 2013 under conditions of light source A and field of view of 2 degrees. did.
(2) Dissolution test A sample having a blackened layer formed on a transparent substrate prepared in Experimental Example 1 below was immersed in an etching solution to perform a blackened layer dissolution test.

As an etching solution, an aqueous solution containing 10% by mass of ferric chloride and 10% by mass of hydrochloric acid used as an etching solution for the copper layer and the balance consisting of water is used, and the temperature of the etching solution is room temperature (25 ° C.). Carried out.

A copper layer having a thickness of 300 nm was formed on the entire surface of one surface of a polyethylene terephthalate resin (PET resin) having a length of 5 cm, a width of 5 cm, and a thickness of 0.05 mm, which is the transparent substrate used in Experimental Example 1. A preliminary experiment was performed in which the sample was immersed in an etching solution. In this case, it was confirmed that the copper layer was dissolved within 10 seconds.

For this reason, when the blackening layer dissolves within 1 minute in the dissolution test, it can be said that the etching layer has the same reactivity as the copper layer. The conductive substrate included can be said to be a conductive substrate including a copper layer and a blackened layer that can be etched simultaneously.
(3) EDS Analysis Regarding the composition of the blackened layer of the sample produced in Experimental Example 1 and having the blackened layer formed on the transparent substrate, SEM-EDS apparatus (SEM: JEOL Ltd. Model: JSM-7001F, EDS: manufactured by Thermo Fisher Scientific Co., Ltd. Model: Detector UltraDry analysis system Noran System 7) was used for EDS analysis.
(4) Environmental resistance test In Experimental Example 2, a sample in which a copper layer and a blackened layer were formed on a transparent substrate was placed in a constant temperature and humidity chamber at a temperature of 60 ° C and a humidity of 90% for 100 hours. A test was conducted.

The optical characteristics of the samples before and after the environmental resistance test were measured and evaluated by changes in L ^* , a ^* and b ^* before and after the environmental resistance test.

For each sample, ΔL ^* , Δa ^* , Δb ^* obtained by subtracting the value after the environmental resistance test from the value before the environmental resistance test is calculated, and ΔL ^* , Δa ^* , Δb ^* ≧ −5 is calculated. ○, −5> ΔL ^* , Δa ^* , Δb ^* ≧ −10 were evaluated as Δ, and −10> ΔL ^* , Δa ^* , Δb ^* were evaluated as ×. Of the ΔL ^* , Δa ^* , and Δb ^* , the lowest evaluation was taken as the evaluation result of the conductive substrate. For example, when ΔL ^* is ◯, Δa ^* is Δ, and Δb ^* is ◯, Δ that is the evaluation result of the lowest evaluation Δa ^{* is} the evaluation of the conductive substrate. In addition, ◯ and Δ were accepted, and x was rejected.

Moreover, after the end of the environmental resistance test, it was evaluated whether or not the copper layer was peeled off from the transparent substrate. Specifically, SEM observation was performed on those in which holes of about 100 μm to 300 μm were observed, and the presence or absence of peeling of the copper layer was evaluated. The case where peeling was observed was evaluated as “Yes”, and the case where peeling was not observed was evaluated as “no”.

The sample manufacturing conditions and the evaluation results in each experimental example will be described below.
[Experimental Example 1]
In Experimental Example 1, 28 samples of Experimental Example 1-1 to Experimental 1-28 shown below were prepared, and an EDS analysis and a dissolution test on the composition of the blackened layer were performed.

In addition, this experiment example was implemented as a preliminary experiment for the experiment example 2 mentioned later, and becomes a reference example.
(About the target)
In this experimental example, as described later, a sample in which a blackened layer was formed on a transparent substrate was prepared, but seven types of targets shown in Table 1 below were used when the blackened layer was formed. When the blackening layer is formed, the target shown in Table 1 below is used alone or in two, and the film is formed by the sputtering method. The film is formed by sputtering.

First, the target No. 5, no. 6, a method for producing a copper-nickel-molybdenum mixed sintered target, that is, a copper-nickel-molybdenum mixed sintered target having target compositions of Cu25Ni15Mo and Cu42Ni16Mo will be described.

As starting material powders, Cu powder (3N CUE13PB <43 μm made by high purity chemical), Ni powder (3N NIE08PB made by high purity chemical 63 μm), Mo powder (manufactured by Nippon Steel, secondary particle size of about 200 μm to 500 μm) Was weighed in a predetermined amount and mixed in a mortar. Under the present circumstances, it measured and mixed so that the mixing ratio of the starting raw material powder might become the value (atomic%) shown in the following Table 2 about each target.

Next, the obtained mixed powder of starting raw material powders was put into a graphite mold having an inner diameter of 3 inches and sintered by a hot pressing method, and five types of sintered bodies No. 1 to No. 5 having different compositions were sintered. A ligature was prepared. The surface pressure during sintering by the hot press method was 136 kgf / cm ² , the hot press temperature (HP temperature) was 900 ° C. or 1000 ° C. shown in Table 2, and the holding time was 1 hour. The relative density of the obtained sintered body was 82% to 93% as shown in Table 2, and it was confirmed that it could be used as a sputtering target.

Therefore, the sintered body No. in which the relative density is particularly high. 3. Sintered body No. 4 was used as a sputtering target. Specifically, the sintered body No. 3 is the target No. 3 in Table 1 described above. 6, the sintered body no. 4 is the target No. 4 in Table 1 described above. Hit 5 respectively.

The target No. shown in Table 1 1-No. 4, no. For No. 7, a sputtering target was produced using a single metal, an alloy, or a molten alloy.
(Sample preparation conditions and evaluation results)
In this experimental example, a total of 28 samples of Experimental Example 1-1 to Experimental Example 1-28 in which a blackening layer containing oxygen, copper, nickel, and molybdenum was formed on a PET substrate that was a transparent substrate. Was made. A specific procedure will be described below by taking the case of Experimental Example 1-1 as an example.

First, a transparent substrate made of polyethylene terephthalate resin (PET, trade name “Lumirror U48”, manufactured by Toray Industries, Inc.) having a length of 5 cm, a width of 5 cm, and a thickness of 0.05 mm was prepared.

And the prepared transparent base material was set to the substrate holder of the sputtering device, and the inside of the chamber was evacuated. The ultimate vacuum in the chamber before sputtering was 1.5 × 10 ⁻⁴ Pa.

After the chamber was evacuated, a blackened layer was formed by sputtering. The blackening layer was formed using a sputtering apparatus (Model: SIH-450, manufactured by ULVAC, Inc.).

When forming the blackened layer, the target No. shown in Table 1 is used as the target as shown in Table 3A. No. 3 Cu40Ni was used, and 200 W was supplied to the target for film formation. When the blackening layer was formed, the substrate holder on which the transparent base material was set was rotated at a speed of 30 rpm.

Further, while the blackening layer was formed by sputtering, argon gas was supplied to the chamber at 5 SCCM and oxygen gas was supplied to 5 SCCM as shown in Table 3A.

In forming the blackened layer, first, a power of 200 W was applied to the target and sputtering was performed for 20 minutes, and the film formation rate was measured. Then, the film formation time until the film thickness reaches 300 nm is calculated from the measured film formation speed, and 200 W DC power is again applied to the target and sputtering is performed for a predetermined time to form a 300 nm thick black layer. .

After film formation until the thickness of the blackened layer reached 300 nm, the film was taken out from the chamber.

A portion of the obtained sample was cut out and subjected to a dissolution test, and the remaining portion was subjected to EDS analysis. The results are shown in Table 3A.

In Experimental Examples 1-2 to 1-28, when the blackening layer was formed, the flow rates of oxygen gas and argon gas in the gas supplied to the target and the chamber are shown in Table 3A for each experimental example. A sample was prepared in the same manner as in Experimental Example 1-1 except that the test was performed under the conditions shown in Table 3B.

As described above, depending on the experimental example, a blackened layer was formed by performing two-way simultaneous sputtering using two targets. For example, in Experimental Example 1-2, as shown in Table 3, a Cu40Ni alloy target and a Mo metal target were used as targets, and a blackened layer was formed by supplying power of 160 W and 130 W to each target. ing.

Evaluation results for Experimental Example 1-2 to Experimental Example 1-28 are also shown in Tables 3A and 3B.

[Experiment 2]
According to the following procedure, a copper layer and a blackened layer are formed on a transparent substrate, and a conductive substrate having a configuration similar to that of FIG. An evaluation of the test was performed.

The procedure for manufacturing a conductive substrate will be described using the case of Experimental Example 2-1.

As the transparent substrate, the same PET substrate as in Experimental Example 1 was used.

Then, the prepared transparent base material was set on a substrate holder of a sputtering apparatus (model name: SIH-450 manufactured by ULVAC, Inc.) equipped with a copper target as a target, and the inside of the chamber was evacuated. The ultimate vacuum in the chamber before sputtering was 1.5 × 10 ⁻⁴ Pa.

Once the inside of the chamber is evacuated, Ar gas is introduced into the chamber at 0.55 Pa, and a 200 W power is supplied to the copper target to form a 300 nm thick copper layer on the transparent substrate. Filmed.

Next, a blackened layer was formed on the upper surface of the copper layer under the same conditions as in Experimental Example 1-1. The film thickness of the blackening layer was formed such that the optical characteristics, particularly L ^*, was minimized, that is, the film thickness was 30.3 nm shown in Table 4A.

In Experimental Examples 2-2 to 2-28, the copper layer was formed in the same manner as in Experimental Example 2-1, and then a blackened layer was formed on the upper surface of the copper layer. The blackening layer is formed on each sample of Experimental Example 2 under the same conditions as in the corresponding Experimental Example of Experimental Example 1, and the film thicknesses are set to the film thicknesses shown in Tables 4A and 4B. did.

For each sample of Experimental Example 2, the experimental example corresponding to Experimental Example 1 is the number after Experimental Example 1 in Experimental Example 1, as shown in Tables 4A and 4B, and Experimental Example 2- The latter number refers to the same experimental example. Specifically, for example, Experimental Example 1-5 and Experimental Example 2-5 are corresponding experimental examples, and the blackening layer was formed under the same conditions.

Experimental Example 2-2 to Experimental Example 2-14, Experimental Example 2-18 to Experimental Example 2-20, Experimental Example 2-23 to Experimental Example 2-27 are examples, and Experimental Example 2-1 and Experimental Example 2- 15 to Experimental Example 2-17, Experimental Example 2-21, Experimental Example 2-22, and Experimental Example 2-28 are comparative examples.

An environmental resistance test was performed on the obtained conductive substrate.

The above evaluation results are shown in Table 4A and Table 4B.

As described above, the blackened layer of each sample of Experimental Example 2 forms a blackened layer under the same conditions as the corresponding sample of Experimental Example 1. For this reason, the composition of the blackening layer and the etching characteristics of each sample of Experimental Example 2 have the same characteristics as the corresponding sample of Experimental Example 1. For this reason, the results of EDS analysis of the blackened layer evaluated in Experimental Example 1 are also shown in Tables 4A and 4B.

According to Table 4, in Example 2-28, the reflectance of light having a wavelength of 550 nm was very high before and after the environmental resistance test, and did not function as a blackened layer.

For Experimental Examples 2-1 to 2-27 other than Experimental Example 2-28, the reflectance of light having a wavelength of 550 nm is 30% or less in both cases before and after the environmental resistance test, and functions as a blackening layer. It was confirmed that it was made.

And according to Table 4A and Table 4B, the blackened layer contains oxygen at 43 atomic% to 60 atomic%, and the total content of copper, nickel, and molybdenum in the blackened layer is 100 atomic%. In this case, it was confirmed that the experimental example in which the molybdenum content was 5 atomic% or more had an evaluation of environmental resistance of ◯ or Δ. That is, it has been confirmed that it has sufficient environmental resistance.

Specifically, for Experimental Example 2-2 to Experimental Example 2-14, Experimental Example 2-18 to Experimental Example 2-20, and Experimental Example 2-23 to Experimental Example 2-27, the evaluation of environmental resistance is ◯ or Δ It was confirmed that

However, for Experimental Example 2-4, in the dissolution test of the blackened layer of Experimental Example 1, it was confirmed that the etching time was as extremely long as 180 seconds. This is because the content of molybdenum in the blackened layer was as high as 63 atomic%, and according to the study of the inventors of the present invention, the Mo content in all metal elements in the blackened layer was 40 atoms. In the case of% or less, the etching time can be set to 1 minute or less, which is preferable.

And when the presence or absence of peeling of the copper layer after the environmental resistance test was evaluated, as shown in Table 4, peeling of the copper layer was observed from the transparent substrate in some experimental examples.

Therefore, in order to suppress peeling of the copper layer, the surface of the transparent substrate on the side where the copper layer or the like is formed is subjected to easy adhesion treatment by irradiating Ar ions with high-frequency plasma to improve the wettability of the substrate. A conductive substrate was produced and evaluated using the base material.

The surface of the transparent substrate was evaluated for the wetting tension based on JIS K6768 (1999), and the samples of Experimental Example 2-1 to Experimental Example 2-28 described above were prepared before Ar ion irradiation. The transparent substrate used here had a wetting tension of 31 mN / m. On the other hand, when Ar ions were irradiated, it was confirmed that the wetting tension was 44 mN / m on the surface irradiated with Ar ions.

As described above, Experimental Example 2 described above except that the surface of the transparent substrate on which the copper layer or the like is formed is irradiated with Ar ions and the transparent substrate having a wet tension of 44 mN / m is used. The conductive substrates of Experimental Example 3-1 to Experimental Example 3-28 were fabricated in the same manner as in Experimental Example 2-1 to Experimental Example 2-28, respectively.

That is, in Experimental Example 3-1 to Experimental Example 3-28, each sample of Experimental Example 3-1 to Experimental Example 3-28 is an experimental example, except that the transparent substrate was previously subjected to easy adhesion treatment. Conductive substrates were fabricated in the same manner as the corresponding experimental examples of 2-1 to Experimental Example 2-28.

Note that the experimental examples corresponding to the experimental examples 2-1 to 2-28 for the samples of the experimental examples 3-1 to 3-28 are the same as the experimental examples 2- The latter number is the same as the experiment example 3 in which the latter number is the same.

Experimental Example 3-2 to Experimental Example 3-14, Experimental Example 3-18 to Experimental Example 3-20, Experimental Example 3-23 to Experimental Example 3-27 are examples, and Experimental Example 3-1 and Experimental Example 3- 15 to Experimental Example 3-17, Experimental Example 3-21, Experimental Example 3-22, and Experimental Example 3-28 are comparative examples.

The obtained conductive substrate was evaluated for the environmental resistance test and the presence or absence of peeling of the copper layer.

Results are shown in Tables 5A and 5B.

According to the results shown in Tables 5A and 5B, it was confirmed that no peeling of the copper layer was observed in any of the experimental examples. This is considered to be because the adhesion between the transparent substrate and the copper layer was increased by applying the easy adhesion treatment to the transparent substrate.

Although the conductive substrate and the method for manufacturing the conductive substrate have been described in the embodiments and examples, the present invention is not limited to the above-described embodiments and examples. Various modifications and changes are possible within the scope of the gist of the present invention described in the claims.

This application claims priority based on Japanese Patent Application No. 2015-162520 filed with the Japan Patent Office on August 20, 2015. The entire contents of Japanese Patent Application No. 2015-162520 are incorporated herein by reference. Incorporate.

10A, 10B, 20A, 20B, 30

Conductive substrate

11, 11A, 11B

Transparent base material

12, 12A,

12B Copper layer

13, 13A, 13B, 131, 132, 131A, 131B, 132A, 132B, 32A,

32B Blackening Layer

31A, 31B wiring

Claims

A transparent substrate;
A copper layer disposed on at least one side of the transparent substrate;
A blackening layer disposed on at least one surface side of the transparent substrate and containing oxygen, copper, nickel and molybdenum, and
The blackening layer contains the oxygen in an amount of 43 atomic% to 60 atomic%,
A conductive substrate in which the content of molybdenum in the blackening layer is 5 atomic% or more when the total content of copper, nickel, and molybdenum in the blackening layer is 100 atomic%.
The content of the molybdenum in the blackening layer is 40 atomic% or less when the total content of copper, nickel, and molybdenum in the blackening layer is 100 atomic%. Conductive substrate.
When the total content of copper, nickel, and molybdenum in the blackened layer is 100 atomic%,
The copper content in the blackened layer is 30 atomic% or more and 70 atomic% or less,
3. The conductive substrate according to claim 1, wherein a content of the nickel in the blackened layer is 15 atomic% or more and 65 atomic% or less.
The copper layer has a thickness of 100 nm or more,
The conductive substrate according to any one of claims 1 to 3, wherein the blackened layer has a thickness of 20 nm or more and 40 nm or less.
The conductive substrate according to any one of claims 1 to 4, wherein a wet tension of a surface of the transparent base on which the copper layer is disposed is 35 mN / m or more.
The conductive substrate according to claim 1, wherein the reflectance of light having a wavelength of 550 nm is 30% or less.
The electroconductive board | substrate as described in any one of Claims 1 thru | or 6 provided with the mesh-shaped wiring.
A transparent substrate preparation step of preparing a transparent substrate;
A copper layer forming step of forming a copper layer on at least one surface side of the transparent substrate;
A blackening layer forming step of forming a blackening layer containing oxygen, copper, nickel and molybdenum on at least one surface side of the transparent substrate;
The blackening layer contains the oxygen in an amount of 43 atomic% to 60 atomic%,
A method for producing a conductive substrate, wherein the content of molybdenum in the blackening layer is 5 atomic% or more when the total content of copper, nickel, and molybdenum in the blackening layer is 100 atomic% .
The content of the molybdenum in the blackening layer is 40 atomic% or less when the total content of copper, nickel, and molybdenum in the blackening layer is 100 atomic%. A method for manufacturing a conductive substrate.
When the total content of copper, nickel, and molybdenum in the blackened layer is 100 atomic%,
The copper content in the blackened layer is 30 atomic% or more and 70 atomic% or less,
The method for producing a conductive substrate according to claim 8 or 9, wherein the nickel content in the blackened layer is 15 atomic% or more and 65 atomic% or less.
The blackening layer forming step includes
Using a copper-nickel-molybdenum mixed sintered target,
11. The conductivity according to claim 8, wherein the blackened layer is formed by a sputtering method while supplying a gas containing oxygen in a ratio of 25 volume% to 55 volume% into the chamber. A method for manufacturing a substrate.
The said transparent base material preparatory process WHEREIN: An easy-adhesion process is implemented to the surface at the side which forms the said copper layer among the said transparent base materials, and wetting tension shall be 35 mN / m or more. The manufacturing method of the electroconductive board | substrate as described in a term.