JP2016218913A - Conductive substrate, and method for producing conductive substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a conductive substrate comprising a copper layer and a blackened layer which can be etched simultaneously, and has excellent visibility, and a method for producing a conductive substrate.SOLUTION: A conductive substrate comprises a transparent base material 11, a copper layer 12 formed on at least one side of the transparent base material 11, and a blackened layer 13 that is formed on at least one side of the transparent base material 11 and comprises oxygen, copper, nickel and tungsten.SELECTED DRAWING: Figure 1

Description

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

  In recent years, as one of input devices for inputting data to a computer main body in a personal computer, a portable terminal, etc., a transparent touch panel that can input data by simply applying a load to the input surface with a finger or a pen ( (Including touch screens) have come to be used frequently.

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

  By the way, in recent years, the display screen including a touch panel has been increased in screen size. Correspondingly, a conductive substrate such as a transparent conductive film for a touch panel is required to have a large area.

  For example, Patent Document 2 includes, instead of an ITO film, an insulating transparent sheet and a plurality of conductive pattern layers that are arranged on the opposite surface of the transparent sheet and adhere to the insulating adhesive layer. A sensor panel for a large display is described in which the pattern layer has a mesh structure made of metal such as copper.

  Patent Document 3 describes an electrode substrate for a touch panel having a transparent substrate and a conductor mesh such as copper that is formed on at least one surface of the transparent substrate and defines a large number of opening regions. .

JP 2003-151358 A JP 2011-018194 A JP 2013-0669261 A

  As described above, when an ITO film is used for the touch panel, 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. Patent Document 1 does not describe a layer using, for example, copper other than the ITO film.

  Further, even when copper is used for the wiring layer, since copper has a metallic luster, there is a problem that the visibility of the display is lowered due to reflection.

  Therefore, in order to improve both the conductivity and visibility characteristics, 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 has been studied. ing.

  However, in order to obtain a conductive substrate having a wiring pattern, it is necessary to form a desired pattern by etching the wiring layer and the blackened layer after forming the wiring layer and the blackened layer. There is a problem that the reactivity to the liquid is different between the wiring layer and the blackened layer.

  That is, if the wiring layer and the blackened layer are simultaneously etched, one of the layers cannot be etched into the target shape. In addition, when the wiring layer etching and the blackening layer etching are performed in separate steps, there is a problem that the number of steps increases. Patent Documents 2 and 3 do not describe means for improving etching properties when a copper layer is provided as a wiring layer.

  The present invention has been proposed in view of such circumstances, and has a copper layer that can be etched at the same time, and a blackened layer. An object is to provide a method for manufacturing a substrate.

  One aspect of the present invention for solving the above problems is formed on a transparent substrate, a copper layer formed on at least one surface of the transparent substrate, and at least one surface of the transparent substrate. And a blackening layer containing oxygen, copper, nickel and tungsten.

  According to one embodiment of the present invention, by including copper, nickel, and tungsten in the blackened layer, an etching process can be performed simultaneously when the wiring layer has a copper layer.

  In one embodiment of the present invention, the blackened layer has a tungsten content of 2 atomic% or more and 25 atomic% or less when the content of copper, nickel, and tungsten in the blackened layer is 100 atomic%. It is preferable that the ratio of copper is 5 atomic% or more and 60 atomic% or less.

  By setting the ratio of copper, nickel, and tungsten contained in the blackened layer within the above numerical range, the etching property of the etching process performed simultaneously with the copper layer can be improved.

  In one embodiment of the present invention, the copper layer preferably has a thickness of 100 nm or more, and the blackened layer preferably has a thickness of 20 nm or more and 50 nm or less.

  By setting the thicknesses of the copper layer and the blackened layer in the above numerical range, a conductive substrate excellent in etching property and visibility of the etching process performed simultaneously with the copper layer can be obtained.

  In one embodiment of the present invention, the reflectance of light with a wavelength of 550 nm is preferably 40% or less.

  Thereby, it becomes an electroconductive board | substrate excellent in visibility.

  In one embodiment of the present invention, a conductive substrate including mesh wiring can be provided.

  According to one embodiment of the present invention, a copper layer and a blackened layer can be etched at the same time, so that a conductive substrate on which a desired pattern is easily formed like a mesh-like wiring can be obtained. .

  In one embodiment of the present invention, the sheet resistance of the blackened layer is preferably 0.2Ω / □ or less.

  Thereby, for example, a contact portion with an electric member such as a wiring can be formed in the blackened layer.

  Another aspect of the present invention includes a copper layer forming step of forming a copper layer on at least one surface side of the transparent substrate, and oxygen, copper, nickel, and tungsten on at least one surface side of the transparent substrate. And a blackened layer forming step of forming a blackened layer to be manufactured.

  According to another aspect of the present invention, by forming a blackened layer containing copper, nickel, and tungsten, a conductive substrate having a blackened layer having good etching properties in an etching process performed simultaneously with the copper layer is manufactured. can do.

  At this time, in another aspect of the present invention, the blackening layer forming step uses a copper-nickel-tungsten mixed sintered target or a copper-nickel-tungsten molten alloy target, and oxygen is 3 volume% or more and 45 volume% or less. The blackening layer is preferably formed by a sputtering method while supplying a gas contained in a ratio of

  By setting such a condition, it is possible to form a blackened layer that can make the blackened layer sufficiently black and can particularly increase the reactivity with the etching solution.

  Moreover, in the other aspect of this invention, you may have further the etching process which performs an etching process simultaneously about a copper layer and a blackening layer.

  According to another aspect of the present invention, since a copper layer and a blackened layer can be etched simultaneously, a conductive substrate on which a desired pattern is easily formed like a mesh-like wiring is manufactured. Can do.

  ADVANTAGE OF THE INVENTION According to this invention, the electroconductive board | substrate provided with the copper layer which can be etched simultaneously, and the blackening layer, and was excellent also in visibility can be provided.

It is sectional drawing which shows the structure of the electroconductive board | substrate which concerns on one Embodiment of this invention, (A) is sectional drawing at the time of forming a copper layer and a blackening layer in the single side | surface of a transparent base material, (B) is It is sectional drawing at the time of forming a copper layer and a blackening layer on both surfaces of a transparent base material. It is sectional drawing which shows the structure of the electroconductive board | substrate which concerns on other one Embodiment of this invention, (A) is sectional drawing at the time of forming a copper layer and a blackening layer in the single side | surface of a transparent base material, (B ) Is a cross-sectional view when a copper layer and a blackening layer are formed on both surfaces of a transparent substrate. In the conductive substrate concerning one embodiment of the present invention, it is an upper surface figure showing the outline of the conductive substrate at the time of forming mesh-like wiring. It is sectional drawing in the AA line of the electroconductive board | substrate which concerns on FIG. 3, (A) is a case where wiring is each arrange | positioned on the upper and lower surfaces of a transparent base material, (B) is a set of transparent base materials. Used, wiring is arranged on the upper and lower surfaces across one transparent base material, and one wiring is arranged between the transparent base materials. It is a flowchart which shows the outline of the manufacturing method of the electroconductive board | substrate which concerns on one Embodiment of this invention.

Hereinafter, the conductive substrate according to the present invention and the method for manufacturing the conductive substrate will be described in detail in the following order. Note that the present invention is not limited to the following embodiments, and various modifications can be made without departing from the gist of the present invention.
1. 1. Conductive substrate 1-1. Configuration example of conductive substrate 1-2. Transparent substrate 1-3. Copper layer 1-4. Blackening layer 1-5. 1. Conductive substrate with mesh-like wiring 2. Manufacturing method of conductive substrate 2-1. Copper layer formation process 2-2. Blackening layer forming step 2-3. Etching process

<1. Conductive substrate>
First, a configuration example of a conductive substrate according to an embodiment of the present invention will be described. The conductive substrate according to one embodiment of the present invention is formed of a transparent base material, a copper layer formed on at least one surface side of the transparent base material, at least one surface side of the transparent base material, oxygen, A blackening layer containing copper, nickel, and tungsten (hereinafter, also simply referred to as “blackening layer”) can be used.

  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 blackened layer having a low sheet resistance is included as described above, the blackened 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.

  Here, the conductive substrate according to one embodiment of the present invention includes a substrate having a copper layer or a blackened layer on the surface of the transparent base material before patterning the copper layer, etc., and a copper layer or blackened layer. It includes a substrate patterned into a wiring shape, that is, a wiring substrate.

(1-1. Configuration Example of Conductive Substrate)
A more specific configuration example of the conductive substrate according to one embodiment of the present invention will be described with reference to FIGS. 1 and 2 are cross-sectional views showing a configuration of a conductive substrate according to an embodiment of the present invention, and (A) is a cross-sectional view when a copper layer and a blackened layer are formed on one side of a transparent substrate. (B) has shown the example of sectional drawing at the time of forming a copper layer and a blackening layer on both surfaces of a transparent base material.

  A conductive substrate according to an embodiment of the present invention includes, for example, a copper layer 12 and a blackened layer on one surface 11a side of the transparent base material 11 as in the conductive substrate 10A illustrated in FIG. 13 can be stacked one by one in that order. Alternatively, for example, like the conductive substrate 10B shown in FIG. 1B, the copper layer 12A on one side 11a side of the transparent base material 11 and the other side (the other side) 11b side, 12B and the blackening layers 13A and 13B can be stacked one by one in that order. In addition, the order which laminates | stacks the copper layer 12 (12A, 12B) and the blackening layer 13 (13A, 13B) is not limited to the example of FIG. 1 (A) and (B), From the transparent base material 11 side. The blackening 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 one surface 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 the one surface 11a side of the transparent substrate 11. 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. 2 (B), the first surface 11a side of the transparent base material 11 and the other surface (the other surface) 11b side are respectively first. Blackening layers 131A and 131B, copper layers 12A and 12B, and second blackening layers 132A and 132B can be stacked in that order.

  In FIGS. 1B and 2B, when a copper layer and a blackening layer are laminated on both surfaces of the transparent base material, the transparent base material 11 is used as a symmetrical surface, and above and below the transparent base material 11. Although the example which arrange | positioned so that the laminated | stacked layer might become symmetrical was shown, it is not limited to this form. For example, in FIG. 2 (B), the configuration on the one surface 11a side of the transparent substrate 11 is the same as the configuration of FIG. 1 (A), in which the copper layer 12 and the blackening layer 13 are laminated in that order. The layers laminated on the top and bottom of the transparent substrate 11 may be asymmetrical.

  Hereinafter, each member which comprises the electroconductive board | substrate which concerns on one Embodiment of this invention is demonstrated.

(1-2. Transparent substrate)
It does not specifically limit as a transparent base material, The insulator film which permeate | transmits visible light, a glass substrate etc. can be used preferably.

  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.

  Moreover, it does not specifically limit about the thickness of a transparent base material, It can select arbitrarily according to the intensity | strength, electrostatic capacitance, light transmittance, etc. which are required when it is set as an electroconductive board | substrate.

(1-3. Copper layer)
Next, the copper layer will be described. Although it does not specifically limit about a copper layer, In order not to reduce the transmittance | permeability of light, it is preferable not to arrange | position an adhesive agent between a copper layer and a transparent base material, or between a blackening layer. That is, the copper layer is preferably formed directly on the upper surface of another member.

  In order to directly form the copper layer on the upper surface of the other 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 base material 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.

  Moreover, when the film thickness of the copper layer is thick, the copper thin film layer can be used as a power feeding layer, and a copper plating layer can be formed by a wet plating method to form a copper layer having a copper thin film layer and a copper plating layer. it can. 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.

(1-4. Blackening layer)
Next, the blackening layer containing oxygen, copper, nickel and tungsten will be described.

  As described above, since the copper layer has a metallic luster, the copper reflects light only by forming a wiring obtained by etching the copper layer on a transparent base material. For example, when used as a conductive substrate for a touch panel, There was a problem that visibility was lowered. Therefore, a method of providing a blackened layer has been studied, but the blackened layer may not have sufficient reactivity with the etching solution, and the copper layer and the blackened layer are simultaneously etched into a desired shape. It was difficult.

  Therefore, the inventors of the present invention have studied, and the layer containing oxygen, copper, nickel and tungsten is black, so it can be used as a blackening layer, and further exhibits sufficient reactivity with the etching solution. Therefore, it has been found that the etching process can be performed simultaneously with the copper layer.

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

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

  Further, the blackening layer can be formed by, for example, a binary simultaneous sputtering method using a copper and nickel alloy target and a tungsten target while supplying oxygen into the chamber.

  Here, one structural example of the manufacturing method of the copper-nickel-tungsten mixed sintering target and the copper-nickel-tungsten molten alloy target for forming the blackening layer will be described.

  The copper-nickel-tungsten mixed sintered target is made of a sintered body of copper, nickel and tungsten powder by hot pressing or hot isostatic pressing (HIP), and is attached to a backing plate. can do.

  In addition, since the copper-nickel-tungsten melt alloy target is difficult to melt, it is difficult to melt copper and tungsten. A tungsten alloy can be produced, hot-rolled, externally processed into a disk, and attached to a backing plate to be a target.

  In addition, the manufacturing method of the copper-nickel-tungsten mixed sintered target and the copper-nickel-tungsten molten alloy target is not limited to the above-described manufacturing method, and is manufactured so as to be a target having a desired composition. The method is not particularly limited as long as it can be used, and can be used.

  In addition, the oxygen content in the gas supplied into the chamber during sputtering is not particularly limited, but the blackened layer is formed while supplying a gas having an oxygen content of 3% to 45% by volume to the chamber. It is preferable to form a film.

  As described above, by setting the ratio of oxygen supply to the chamber to 3% by volume or more, the color of the blackened layer can be sufficiently black, and the function as the blackened layer can be sufficiently exhibited. preferable. The supply ratio of oxygen into the chamber is more preferably 5% by volume or more.

Moreover, the reactivity with respect to the etching liquid of a blackening layer can be improved especially by making the supply amount of oxygen in the gas supplied into a chamber into 40 volume% or less. For this reason, when etching with a copper layer, a copper layer and a blackening layer can be easily made into a desired pattern, and it is preferable. Furthermore, the reflectance, lightness (L ^* ), and chromaticity (a ^* , b ^* ) of the optical properties are all preferable as a blackened layer.

In particular, from the viewpoint of making the chromaticity (a ^* , b ^* ) particularly good as a blackened layer, the oxygen supply ratio into the chamber is more preferably 15% by volume or less.

  Note that 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, 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 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, it is necessary to select the composition of a target according to the composition of the target blackening layer, and the easiness of the element in a target to fly.

  As a target used when performing sputtering, for example, a mixed sintered target of copper-nickel-tungsten or a molten alloy target of copper-nickel-tungsten can be used as described above. The composition of the target is not particularly limited, but the component constituting the target preferably contains tungsten in a proportion of 2 atomic percent to 30 atomic percent, and contains tungsten in a proportion of 5 atomic percent to 25 atomic percent. It is more preferable. Copper is preferably contained at a ratio of 2 atomic% to 60 atomic%, and more preferably copper is contained at a ratio of 5 atomic% to 55 atomic%. In these cases, the balance can be made of nickel.

  The formed blackening layer contains oxygen, copper, nickel, and tungsten. When the total of copper and the metal elements of nickel and tungsten is 100 atomic%, tungsten is 2 atomic% or more and 25 atomic%. The following is preferable. If the tungsten content is less than 2 atomic%, the reflectance is not lowered sufficiently, which is not preferable. If the tungsten content exceeds 25 atomic%, the etching property is deteriorated. Further, copper is preferably 5 atomic% or more and 60 atomic% or less. If the copper content is less than 5 atomic%, the etching property is not sufficient, which is not preferable. If the copper content exceeds 60 atomic%, it is not preferable because the color easily changes due to moisture in the atmosphere. The balance is nickel.

Oxygen, copper, nickel and tungsten may be contained in any form. Copper, nickel, or tungsten generates, for example, copper oxide (Cu ₂ O, CuO, Cu ₂ O ₃ ), nickel oxide (NiO), tungsten oxide (WO ₃ , WO ₂ ), or a composite oxide thereof, and the compound May be contained in the blackened layer.

  The blackening layer may be a layer composed of only one kind of substance containing oxygen, copper, nickel and tungsten simultaneously, such as a copper-nickel-tungsten mixture containing oxygen. For example, it may be a layer containing one or more kinds of substances selected from the above-described copper-nickel-tungsten mixture containing oxygen, copper oxide, nickel oxide, and tungsten oxide. .

  Although the thickness of a blackening layer is not specifically limited, For example, it is preferable that it is 20 nm or more, and it is more preferable to set it as 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 blackening layer is not particularly limited, but even if it is thicker than necessary, the time required for film formation and the time required for etching when forming the wiring are increased, resulting in an increase in cost. Will be invited. For this reason, the thickness of the blackened layer is preferably 50 nm or less, and more preferably 45 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.

  Further, in order to form a contact portion with an electric member such as wiring in the blackened layer, the sheet resistance of the blackened layer is preferably 0.2Ω / □ or less. According to the study of the inventors of the present invention, the sheet resistance of the blackened layer has a correlation with the oxygen concentration in the atmosphere when the blackened layer is formed. The lower the oxygen concentration in the atmosphere when forming the blackened layer, the lower the sheet resistance of the blackened layer, which is preferable. In particular, when the sheet resistance of the blackened layer is sufficiently low, the oxygen concentration when forming the blackened layer is preferably 50% by volume or less, and more preferably 35% by volume or less.

  So far, the conductive substrate according to one embodiment of the present invention has been described for each configuration. However, in the conductive substrate according to one embodiment of the present invention, a copper layer, oxygen, copper on a transparent substrate. In addition, since the blackening layer containing nickel and tungsten is provided, reflection of light by the copper layer can be suppressed.

  The degree of light reflection of the conductive substrate according to the embodiment of the present invention is not particularly limited. For example, the conductive substrate according to the embodiment of the present invention has a light reflectance of 550 nm. It is preferably 40% or less, more preferably 30% or less, and particularly preferably 20% or less. This is preferable when the reflectance of light having a wavelength of 550 nm is 40% or less, for example, even when used as a conductive substrate for a touch panel, since the display visibility hardly deteriorates.

  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, when the copper layer 12 and the blackened layer 13 are laminated in this order on one surface 11a of the transparent substrate 11 as shown in FIG. It can be measured from the surface side A of the conductive substrate 10A.

  In addition, 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 substrate 11, the blackened The reflectance can be measured from the surface 11b side of the transparent substrate 11, which is the side on which the 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.

(1-5. Conductive substrate with mesh wiring)
As described above, the conductive substrate according to an embodiment of the present invention can be preferably used as a conductive substrate for a touch panel, for example. In this case, the conductive substrate can be configured to have mesh-like wiring.

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

  For example, a two-layer wiring can be used as a mesh wiring. A specific configuration example is shown in FIG. FIG. 3 shows a top 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 blackened layer. The conductive substrate 30 shown in FIG. 3 has a transparent base material 11, a plurality of wirings 31A parallel to the X-axis direction in the drawing, and a plurality of wirings 31B parallel to the Y-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 in the same shape as the wirings 31A and 31B.

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

  First, as shown to FIG. 4 (A), as for the electroconductive board | substrate 30A, wiring 31A, 31B may be arrange | positioned at 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, the conductive substrate 30B uses a pair of transparent base materials 11A and 11B, 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 may be arrange | positioned between 11 A of transparent base materials, and the transparent base material 11B. Also in this case, blackened layers 32A and 32B etched in the same shape as the wiring are disposed on the upper surfaces of the wirings 31A and 31B. As described above, the arrangement of the blackened layer and the copper layer is not limited. For this reason, in either case of FIGS. 4A and 4B, the arrangement of the blackening layers 32A and 32B and the wirings 31A and 31B can be reversed. For example, a plurality of blackening layers can be provided.

  However, the blackening layer is preferably disposed on the surface of the copper layer surface where light reflection is particularly desired to be suppressed. Therefore, in the conductive substrate 30B shown in FIG. 4B, for example, when it is necessary to suppress the reflection of light from the lower surface side in the figure, the position of the blackening layer 32B and the position of the wiring 31B Are preferably reversed. Further, in addition to the blackening layer 32B, a blackening layer may be further provided between the wiring 31B and the transparent substrate 11B.

  The conductive substrate having the mesh-like wiring shown in FIGS. 3 and 4A is, for example, copper layers 12A and 12B on both surfaces of the transparent substrate 11 as shown in FIGS. 1B and 2B. , And a blackened layer 13A (131A, 132A), 13B (131B, 132B) can be formed from a conductive substrate.

  The case where it is formed using the conductive substrate of FIG. 1B 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 shown in FIG. Etching is performed so that a plurality of linear patterns parallel to the X-axis direction are arranged at predetermined intervals. The X-axis direction in FIG. 1B means a direction parallel to the width direction of each layer in FIG.

  A plurality of linear patterns parallel to the Y-axis direction in FIG. 1B are arranged at predetermined intervals on the copper layer 12B and the blackening layer 13B on the other surface 11b side of the transparent substrate 11. Etching is performed so that Note that the Y-axis direction in FIG. 1B means a direction perpendicular to the paper surface.

  Through 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.

  The conductive substrate having mesh-like wirings shown in FIG. 3 can be formed by using two conductive substrates shown in FIG. 1A or FIG. 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 parallel to the X-axis direction, respectively. Etching is performed so that a plurality of linear patterns are arranged at predetermined intervals. 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 the two conductive substrates are bonded is not particularly limited, and the surface A in FIG. 1A in which the copper layer 12 and the like are laminated as shown in FIG. The surface 11b in FIG. 1A on which the layer 12 and the like are not stacked may be bonded.

  In addition, it is preferable that the blackening layer is arrange | positioned in the surface which wants to suppress especially reflection of light among the copper layer surfaces. 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 position of the blackened layer 32B and the position of the wiring 31B are reversed. It is preferable to arrange in. Further, in addition to the blackening layer 32B, a blackening layer may be further provided between the wiring 31B and the transparent substrate 11B.

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

  Note that the width of the wiring and the distance between the wirings in the conductive substrate having the mesh-like wiring shown in FIG. 3, FIG. 4 (A), and FIG. 4 (B) are not particularly limited. It can be selected according to the amount of current flowing in the current.

  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.

<2. Manufacturing method of conductive substrate>
Next, a configuration example of the method for manufacturing the conductive substrate according to the present embodiment will be described.

  The method for producing a conductive substrate according to an embodiment of the present invention includes a copper layer forming step S11 for forming a copper layer on at least one surface side of a transparent substrate, oxygen on at least one surface side of the transparent substrate, A blackening layer forming step S12 for forming a blackening layer containing copper, nickel and tungsten.

  Hereinafter, a method for manufacturing a conductive substrate according to an embodiment of the present invention will be described more specifically with reference to FIG. FIG. 5 is a flowchart showing an outline of a method for manufacturing a conductive substrate according to an embodiment of the present invention. In addition, since it can be set as the structure similar to the case of the above-mentioned electroconductive board | substrate except the point demonstrated below, description is abbreviate | 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 arranged on the transparent substrate 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 S11 and the blackened layer forming step S12 and the number of times of execution are not particularly limited, and can be performed at an arbitrary number of times according to the structure of the conductive substrate to be formed. can do.

  Here, the transparent base material is not particularly limited, and is formed of, for example, an insulating film that transmits visible light, a glass substrate, or the like. Moreover, the transparent base material can be cut into any size as required.

(2-1. Copper layer forming step)
The copper layer forming step S11 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 process of forming a copper thin film layer, for example with a dry plating method. Further, the copper layer forming step may include a step of forming a copper thin film layer by a dry plating method and a step of forming a copper plating layer by a wet plating method using the copper thin film layer as a power feeding layer.

  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 on which a transparent base material or a blackened layer is formed 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, while conveying the substrate from the unwinding roll at a speed of, for example, about 1 to 20 m per minute, power is supplied from the DC power supply for sputtering connected to the cathode, and sputtering discharge is performed, and the desired material is applied on the substrate. The copper thin film layer can be continuously formed.

  The conditions in the step of forming the copper plating layer by the wet plating method, that is, the conditions for 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.

(2-2. Blackening layer forming step)
Next, the blackening layer forming step S12 will be described. The blackening layer forming step S12 is not particularly limited, but as described above, the blackening layer can be formed by a sputtering method.

  In this case, a target of copper, nickel, tungsten mixed sintered body or an alloy target of copper, nickel, tungsten can be used as the target. Further, as described above, a copper target and a nickel-tungsten alloy target can also be used. When a target of copper, nickel, tungsten mixed sintered body or an alloy target of copper, nickel, tungsten is used as the target, the target of copper tungsten mixed sintered body is 100 and the total of the metal elements of copper and nickel and tungsten is 100. In the case of atomic percent, it is preferable that tungsten is 2 atomic percent or more and 25 atomic percent or less. Copper is preferably 5 atomic% or more and 60 atomic% or less. The balance is nickel.

  Further, it is preferable to perform sputtering while supplying oxygen into the chamber at a ratio of 3 volume% or more and 45 volume% or less. In particular, the supply ratio of oxygen into the chamber is more preferably 5% by volume or more and 40% by volume or less.

  Note that 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, argon or helium can be supplied.

  And as for the electroconductive board | substrate obtained by the manufacturing method of the electroconductive board | substrate which concerns on one Embodiment of this invention, it is preferable that the thickness of a copper layer is 100 nm or more similarly to the above-mentioned electroconductive board | substrate, 150 nm or more More preferably. Moreover, although the upper limit of the thickness of a copper layer is not specifically limited, It is preferable that it is 3 micrometers or less, and it is more preferable that it is 300 nm or less.

  Also in the conductive substrate obtained by the method for manufacturing a conductive substrate according to an embodiment of the present invention, the thickness of the blackening layer is not particularly limited, but is preferably 20 nm or more, for example. More preferably, it is 25 nm or more. The upper limit of the thickness of the blackening layer is not particularly limited, but is preferably 50 nm or less, and more preferably 45 nm or less.

  The blackening layer contains oxygen, copper, nickel, and tungsten. When the total of copper and the metal elements of nickel and tungsten is 100 atomic%, tungsten is 2 atomic% or more and 25% atomic or less. preferable. Copper is preferably 5 atomic% or more and 60% or less. The balance is nickel.

  If the tungsten content is less than 2 atomic%, the reflectance is not lowered sufficiently, which is not preferable. If the tungsten content exceeds 25 atomic%, the etching property is deteriorated. Less than 5 atomic% of copper is not preferable because the etching property is not sufficient. If it exceeds 60 atomic%, it is not preferable because the color easily changes due to moisture in the atmosphere.

Oxygen, copper, nickel and tungsten may be contained in any form. For example, copper nickel and tungsten may form mixed sintering, and copper-nickel-tungsten mixed sintering containing oxygen may be contained in the blackened layer. Further, copper, nickel, or tungsten produces, for example, copper oxide (Cu ₂ O, CuO, Cu ₂ O ₃ ), nickel oxide (NiO), tungsten oxide (WO ₃ , WO ₂ ), or a composite oxide thereof, A compound may be contained in the blackened layer.

  The blackening layer may be a layer composed of only one kind of substance containing oxygen, copper, nickel and tungsten simultaneously, such as a mixture of copper, nickel and tungsten containing oxygen. Further, for example, it is a layer containing one or more substances selected from copper-nickel-tungsten mixed sintering containing oxygen, copper oxide, tungsten oxide, nickel and tungsten oxide described above. May be.

  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. Even when the blackened layer is located on the outermost surface, the copper layer Is preferable because it is not necessary to expose the film.

  And in order to form a contact part with electric members, such as wiring, in a blackening layer, it is preferred that sheet resistance of a blackening layer is 0.2 ohms / square or less. According to the study of the inventors of the present invention, the sheet resistance of the blackened layer has a correlation with the oxygen concentration in the atmosphere when the blackened layer is formed. The lower the oxygen concentration in the atmosphere when forming the blackened layer, the lower the sheet resistance of the blackened layer, which is preferable. In particular, when the sheet resistance of the blackened layer is sufficiently lowered, the oxygen concentration when forming the blackened layer is preferably 20% by volume or less, and more preferably 16% by volume or less.

(2-3. Etching process)
And the conductive substrate obtained by the manufacturing method of the conductive substrate which concerns on one Embodiment of this invention can be used as the conductive substrate provided with the mesh-shaped wiring. In this case, in addition to the above-described steps, an etching step S13 for forming a wiring by etching the copper layer and the blackened layer can be further included.

  In the etching step S13, for example, a resist having an opening corresponding to a portion to be removed by etching is first formed on the outermost surface of the conductive substrate. In the case of the conductive substrate 10A shown in FIG. 1A, a resist can be formed on the exposed surface A of the blackening layer 13 disposed on the conductive substrate 10A. 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 the copper layers 12A and 12B and the blackening layers 13A and 13B are arranged on both surfaces of the transparent base material 11 as shown in FIG. 1B, predetermined surfaces are respectively provided on the outermost surfaces A and B of the conductive substrate 10B. A resist having an opening having a shape may be formed, and the copper layers 12A and 12B and the blackening layers 13A and 13B formed on both surfaces of the transparent substrate 11 may be etched simultaneously.

  In addition, the copper layers 12A and 12B and the blackening layers 13A and 13B formed on both sides of the transparent base material 11 can be etched 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.

  In the conductive substrate according to one embodiment of the present invention, the blackening layer exhibits reactivity to the etching solution similar to that of the copper layer. Therefore, the etching solution used in the etching step is not particularly limited, and is generally used. In addition, an etchant used for etching the copper layer can be preferably used. As an etchant, 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.

  Although the etching solution can be used at room temperature, it is preferably heated to increase the reactivity. For example, it is preferably heated to 40 ° C. or higher and 50 ° C. or lower.

  Note that a specific form of the mesh-like wiring obtained by the above-described etching process is as described above, and thus description thereof is omitted here.

  In addition, as described above, two conductive substrates having a copper layer and a blackened layer are bonded to one surface side of the transparent base material 11 shown in FIGS. 1A and 2A and meshed. In the case where the conductive substrate is provided with a conductive wiring, 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 according to one embodiment of the present invention have been described above. According to such a conductive substrate, since the copper layer and the blackened layer show substantially the same reactivity with the etching solution, a desired wiring can be easily formed. Further, since the blackened layer is black, reflection of light by the copper layer can be suppressed, and for example, when a conductive substrate for a touch panel is used, a reduction in visibility can be suppressed.

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

(Evaluation method)
First, the evaluation method of the sample produced in each experiment example mentioned later is demonstrated.
(1) Optical characteristics (reflectance, brightness, chromaticity)
Optical properties (reflectance) of the conductive substrates prepared in Experimental Examples 2 and 3 below are measured, and lightness (L ^* ), chromaticity (a ^* , b ^* ) was calculated.

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

  In Experimental Example 2 and Experimental Example 3 below, conductive substrates having a cross-sectional shape similar to that shown in FIG. Therefore, with respect to the outermost surface A in FIG. 1A on the side where the copper layer and blackening layer of the produced conductive substrate are formed, an incident angle of 12 ° and a light receiving angle of 12 ° are in the range of wavelengths from 350 nm to 780 nm. Then, the light whose wavelength was changed every 1 nm was irradiated, and the reflectance for each wavelength was measured.

  And the average value of the reflectance with respect to the light whose wavelength is 350 nm or more and 780 nm or less was made into the visible light average reflectance. Moreover, the measured value of the reflectance with respect to light having a wavelength of 550 nm was defined as the reflectance with respect to light having 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 irradiated with 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 having a thickness of 300 nm formed on a transparent substrate, which was prepared in Experimental Example 1 and Experimental Example 3 below, was immersed in an etching solution, and a dissolution test of the blackened layer was performed.

  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 method for evaluating the dissolution test will be described. In order to define the evaluation of the dissolution test, the thickness of the transparent base material used in Experimental Example 1 is 5 cm in length, 5 cm in width, 0.05 mm in thickness on the entire surface on one surface of polyethylene terephthalate resin (PET resin). A preliminary experiment was performed in which a sample on which a 300 nm copper layer was formed was immersed in an etching solution. In this case, it was confirmed that the copper layer was dissolved within 10 seconds.

  Therefore, after the samples in which the blackened layer was formed on the transparent substrate prepared in each experimental example were immersed in the etching solution, evaluation was performed as follows according to the time required until the entire blackened layer was dissolved.

  A sample in which the entire blackened layer was dissolved within 10 seconds after being immersed in the etching solution was evaluated as ◎. In addition, after immersion in the etchant, the time required for dissolution of the entire blackened layer is longer than 10 seconds and within 30 seconds is marked with ◯, and when it is longer than 30 seconds and within 1 minute, ◇ is marked with ◇. Those with a length of 3 minutes or less were evaluated as Δ. And after immersion in etching liquid, even if it exceeded 3 minutes, the blackened layer did not melt | dissolve the whole quantity, but evaluated what was left as x.

  In the dissolution test, when the blackened layer dissolves within 1 minute, it can be said that it has the same reactivity as the copper layer with respect to the etching solution, and includes the blackened layer and the copper layer. The conductive substrate can be said to be a conductive substrate including a copper layer and a blackened layer that can be etched simultaneously.

(3) EDS analysis The EDS analysis is the same except that the conductive substrate production conditions shown in Experimental Examples 1 and 3 were set, the thickness of the blackened layer was 300 nm, and the copper layer was not formed. SEM-EDS apparatus (SEM: JEOL Ltd. Model: JSM-7001F, EDS: Thermo Fisher Scientific Co., Ltd. Model: Detector UltraDry analysis system NORAN System 7).

(4) Sheet resistance Regarding samples prepared in Experimental Example 2 and Experimental Example 3 on which a copper layer and a blackened layer are formed on a transparent substrate, a sample (hereinafter, the same sample is also referred to as “sample for measuring sheet resistance”). And the sheet resistance of the blackened layer was evaluated.

  Sheet resistance was measured using a four-probe method. In the four-probe method, four needle-shaped electrodes are arranged on the same line on the surface of the sample to be measured, a constant current is passed between the two outer probes, and the potential difference between the two inner probes is measured. This is a method of measuring resistance. In the measurement, the measurement was performed using a four-point probe (Mitsubishi Chemical Corporation model: Loresta IP).

Then, according to the following formula (1), the sheet resistance Rs was calculated by multiplying the resistance value (V / I) measured using the four-probe method by a correction coefficient RCF (Resistency Correction Factor).
Rs = V / I × RCF Formula (1)

  The sample manufacturing conditions and the evaluation results in each experimental example will be described below.

[Experiment 1]
In Experimental Example 1, nine types of samples (Experimental Examples 1-1 to 1-9) of conductive substrates in which only an oxide film of copper-nickel-tungsten was formed on a PET substrate to evaluate the blackened film were prepared. Then, an EDS analysis on the composition of the blackened layer and a dissolution test 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.

(Experimental Example 1-1 to Experimental Example 1-9)
In order to evaluate the blackened layer, samples (Experimental Examples 1-1 to 1-9) in which a blackened layer containing oxygen, copper, nickel, and tungsten was formed on a polyethylene terephthalate substrate were prepared. The specific procedure is described below.

  First, a transparent substrate made of polyethylene terephthalate resin (PET, trade name “Lumirror U48”, manufactured by Toray Industries, Inc.) having a length of 6 cm, a width of 6 cm, and a thickness of 0.05 mm was prepared.

  Next, a blackening layer was formed by direct current sputtering. The blackening layer was formed using a sputtering apparatus (Model: SIH-450, manufactured by ULVAC, Inc.).

  Specific conditions for sputtering when forming the blackening layer will be described. Two targets, a nickel-7 at% tungsten alloy and a copper target, were used as targets for forming the blackening layer. The nickel-7 at% tungsten alloy target means an alloy target composed of 7 at% tungsten and the balance being nickel.

  When the blackening layer was formed by sputtering, oxygen gas and argon gas were supplied into the chamber so that the total amount was 10 SCCM.

  Specifically, the ratio of argon gas to oxygen gas supplied into the chamber is changed from 8.5: 1.5, 7: 3, 6: 4 to the ratios shown in Table 1 (argon gas, oxygen gas). Sputtering was performed while supplying at each volume% of gas).

A specific procedure for forming the blackening layer will be described. First, the prepared transparent base material was set on a substrate holder, and the inside of the chamber was evacuated. In addition, the ultimate vacuum in the chamber before sputtering was 1.5 × 10 ⁻⁴ Pa.

  And about each experiment example, argon gas and oxygen gas were supplied in the chamber so that the conditions of the gas component ratio of Table 1 might be satisfy | filled. The substrate holder was rotated at a speed of 30 rpm.

  The DC power calculated in advance so that the metal ratio (Cu: Ni: W, at%) of copper, nickel, and tungsten supplied from the target becomes the predetermined composition ratio shown in Table 1 for each experimental example. It applied to each target and the blackening layer (film thickness of 300 nm) was produced by binary simultaneous sputtering.

  In addition, the magnitude | size of DC electric power for making the metal ratio of the copper supplied from a copper target, a nickel-7at% tungsten alloy target, and a nickel-tungsten alloy into a desired value was computed by the following preliminary tests.

  A copper film and a nickel-tungsten film were formed on a glass plate with a DC power of 400 W and a sputtering time of 20 minutes under the gas conditions in each experimental example, and the film thickness was measured to form a film formation rate (Va: nm / (W · min), a = Cu, Ni—W) was determined.

  From this, the DC power (Pai) applied to each target was calculated from the following formula, assuming that the metal ratio of the target composition of copper and nickel-tungsten alloy was m: n, the film thickness was 300 nm, and the sputtering time was 20 minutes.

As described above, a nickel-7 at% tungsten alloy is used as the nickel-tungsten alloy. For this reason, the specific target composition of nickel and tungsten is calculated with 7% of the metal ratio m of the target composition being tungsten and the balance being nickel.
P _Cu = 300 × m / (m + n) / (20 × V _Cu )
P _Ni-W = 300 × n / (m + n) / (20 × V _Ni-W )

  Table 1 summarizes the manufacturing conditions of the nine types of blackened layers and the numbers of the experimental examples. Samples manufactured under the conditions shown in Table 1 were designated as Experimental Example 1-1 to Experimental Example 1-9, respectively.

For example, in Experiment 1-1, the gas ratio (SCCM ratio) of oxygen, nitrogen, and argon supplied into the chamber is condition 1 (Ar: O ₂ = 8.5: 1.5). Further, for example, in Experimental Example 1-1, the charged metal composition ratio (Cu: Ni: W, each at%), which is the target composition ratio of the metal component supplied from the nickel-7 at% tungsten alloy target and the copper target, is 50. 0.0: 46.5: 3.5 DC power was applied to each target. Specifically, as shown in Table 1, DC power is applied to the nickel-7 at% tungsten alloy target and the copper target at a ratio of 50:50.

(Evaluation of composition of blackened layer: EDS analysis result)
An EDS analysis of the blackened layer of each experimental example was performed. The results are shown in Table 2. From the EDS analysis shown in Table 2, it was confirmed that all the blackened layers formed in Experimental Examples 1-1 to 1-9 contained copper, nickel, tungsten, and oxygen.

  That is, it can be confirmed that a blackened layer containing oxygen, copper, nickel, and tungsten can be formed by a binary simultaneous sputtering method using a copper target and a nickel-7 at% tungsten alloy target while supplying oxygen. It was.

(Dissolution test results)
A dissolution test was performed at 25 ° C. using an aqueous solution containing 10% by mass of ferric chloride, 10% by mass of hydrochloric acid, and the balance water as an etching solution. Table 3 shows the results based on the evaluation described in (2) Dissolution Test.

  According to the results shown in Table 3, when the blackened films of the samples of Experimental Examples 1-1 to 1-9 are etched, Experimental Example 1-1 and Experimental Example 1 where the amount of copper is high and the amount of oxygen is low. 4, it was confirmed that the blackened layer was dissolved within 10 seconds as in the case of copper alone. Under other conditions, it was confirmed that the dissolution time tends to be longer when there is less copper and more oxygen.

[Experiment 2]
Next, a conductive substrate was produced with reference to the result of the preliminary experiment conducted in Experimental Example 1, and the evaluation was performed.

  In this experimental example, a conductive substrate having the structure shown in FIG. 1A, that is, a structure in which a copper layer and a blackening layer were formed on one surface of a transparent base material was produced. As the conductive substrate, as shown in Table 4, 20 types of samples with different film formation conditions for the blackened layer were prepared. In Experimental Example 2-1 to Experimental Example 2-20, the blackened layer is formed under the same conditions as Experimental Example 1-1 to Experimental Example 1-9 except that the film thickness is different.

  Below, the preparation procedure of the electroconductive board | substrate of Experimental example 2-1 to Experimental example 2-20 is demonstrated. First, a transparent substrate 11 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.

  Next, the copper layer 12 was formed on the entire surface of one surface of the transparent substrate 11 (copper layer forming step). The copper layer 12 formed a copper thin film layer by a sputtering method, and then formed a copper plating layer by a wet plating method using the copper thin film layer as a power feeding layer. Specifically, a copper thin film layer having a thickness of 100 nm was first formed on one surface of the transparent substrate 11 by a direct current sputtering method using a Cu target (manufactured by Sumitomo Metal Mining Co., Ltd.). Thereafter, a copper plating layer was laminated by 0.5 μm by electroplating to form a copper layer 12.

  Next, a blackening layer 13 was formed on the entire surface of the copper layer 12 by a binary simultaneous sputtering method in the same manner as in Experimental Example 1 (blackening layer forming step). In Experimental Example 2-1 to Experimental Example 2-20, a blackened layer was formed under the same conditions and procedures except that the film thickness was different from Experimental Example 1-1 to Experimental Example 1-9.

  By the sputtering method, as shown in Table 4, the blackened layer was formed by changing the thickness of the blackened layer between 20 nm and 40 nm. The conductive substrate obtained by the above steps was evaluated for optical property evaluation (reflectance measurement, brightness calculation).

(Optical characteristics: Evaluation of reflectance and brightness)
The reflectance of the produced conductive substrate was measured. From the measurement results of the reflectance, the visible light average reflectance and the reflectance with respect to light having a wavelength of 550 nm were obtained. The results are shown in Table 4.

Moreover, the value of the lightness L ^* calculated from the reflectance obtained by the measurement was calculated. The results are also shown in Table 4. From the results shown in Table 4, the experiment numbers 2-4, 2-6, 2-10, 2-14, 2-15, and 2-17 have an average visible light reflectance of 40% and reflectivity with respect to light having a wavelength of 550 nm. The brightness L ^* value was as low as less than 40, and it was confirmed that the blackened layer had good optical characteristics.

(Sheet resistance)
About each sample for sheet resistance etc. measurement of Experimental Example 2-1 to Experimental Example 2-20, the sheet resistance was measured by the above-described sheet resistance evaluation method. In any sample, the sheet resistance was 0.2Ω / □ or less, and the sheet resistance value was sufficiently low when used as a wiring material.

[Experiment 3]
In Experimental Example 3, a Cu—Ni—W alloy target (Ni-7 at% W-10 at% Cu) was produced, and film formation was performed using the alloy target. First, the manufacturing method of a Cu-Ni-W alloy target is demonstrated.

  As raw materials, a Ni-7 at% W target made by Sumitomo Metal Mining, a Cu target made by Sumitomo Metal Mining, and tungsten were prepared. And these were weighed so that it might become Cu: Ni: W = 10: 71: 19 by mass ratio, and it melt | dissolved in the vacuum melting furnace, and produced the ingot. Next, a 3-inch sputter target was cut out from the ingot by wire cutting to produce a Cu—Ni—W alloy target.

  As a result of analyzing the composition of the produced Cu—Ni—W alloy target, it was Ni-7 at% W-10 at% Cu. In addition, Ni-7at% W-10at% Cu means that 7 at% W and 10 at% Cu are contained in the Cu-Ni-W alloy, and the balance is nickel. Such a composition is also indicated as Ni7W10Cu.

  Conductivity having a structure shown in FIG. 1A using the produced Cu—Ni—W alloy target, that is, a structure in which a copper layer and a blackening layer are formed on one surface of a transparent substrate. A substrate was produced. As the conductive substrate, as shown in Table 7, ten types of samples having different blackening layer deposition conditions were prepared.

  The procedure for producing the conductive substrate of Experimental Example 3-1 to Experimental Example 3-10 will be described in detail below. First, a transparent substrate 11 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.

  Next, the copper layer 12 was formed on the entire surface of one surface of the transparent substrate 11 (copper layer forming step). The copper layer 12 formed a copper thin film layer by a sputtering method, and then formed a copper plating layer by a wet plating method using the copper thin film layer as a power feeding layer. Specifically, a copper thin film layer having a thickness of 100 nm was first formed on one surface of the transparent substrate 11 by a direct current sputtering method using a Cu target (manufactured by Sumitomo Metal Mining Co., Ltd.). Thereafter, a copper plating layer was laminated by 0.5 μm by electroplating to form a copper layer 12.

  Next, a blackened layer 13 was formed on the entire surface of the copper layer 12 by sputtering using the above-described Cu—Ni—W alloy target (blackened layer forming step). The blackening layer was formed in the same procedure as in Experimental Examples 1 and 2.

First, the prepared transparent base material was set on a substrate holder, and the inside of the chamber was evacuated. In addition, the ultimate vacuum in the chamber before sputtering was 1.5 × 10 ⁻⁴ Pa.

  And about each experiment example, argon gas and mixed gas were supplied in the chamber so that the conditions of the gas component ratio of Table 7 might be satisfy | filled. The substrate holder was rotated at a speed of 30 rpm.

  Then, DC power was applied to the Cu—Ni—W alloy target, and a blackened layer was formed so as to have the film thicknesses shown in Table 7, respectively, to produce a conductive substrate.

  Further, the same applies except that the sample for EDS analysis and solubility test is the same as the conductive substrate production condition described above, except that the copper layer is not formed and the blackened layer is directly formed on the transparent substrate with a film thickness of 300 nm. An evaluation sample was prepared under the conditions described above. The evaluation results are shown in Tables 5 and 6.

  About each sample for sheet resistance etc. measurement of Experimental example 3-1 to Experimental example 3-10, sheet resistance was measured with the above-mentioned sheet resistance evaluation method. In any sample, the sheet resistance was 0.2Ω / □ or less, and the sheet resistance value was sufficiently low when used as a wiring material.

10A, 10B, 20A, 20B, 30, 30A, 30B 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 (copper layer)

Claims (9)

A transparent substrate;
A copper layer formed on at least one surface of the transparent substrate;
And a blackened layer formed on at least one surface side of the transparent base material and containing oxygen, copper, nickel and tungsten. The blackening layer is
When the content of copper, nickel and tungsten in the blackened layer is 100 atomic%, the ratio of tungsten is 2 atomic% or more and 25 atomic% or less, and the ratio of copper is 5 atomic% or more and 60 atomic%. The conductive substrate according to claim 1, which is at most atomic%. The copper layer has a thickness of 100 nm or more,
The conductive substrate according to claim 1, wherein the blackened layer has a thickness of 20 nm to 50 nm.   The conductive substrate according to any one of claims 1 to 3, wherein a reflectance of light having a wavelength of 550 nm is 40% or less.   The electroconductive board | substrate as described in any one of Claims 1 thru | or 4 provided with the mesh-shaped wiring.   The conductive substrate according to claim 1, wherein the blackened layer has a sheet resistance of 0.2Ω / □ or less. A copper layer forming step of forming a copper layer on at least one surface side of the transparent substrate;
A blackened layer forming step of forming a blackened layer containing oxygen, copper, nickel and tungsten on at least one surface side of the transparent base material. The blackening layer forming step includes
Using a copper-nickel-tungsten mixed sintered target or a copper-nickel-tungsten molten alloy target,
The method for manufacturing a conductive substrate according to claim 7, wherein the blackened layer is formed by a sputtering method while supplying a gas containing oxygen at a ratio of 3% by volume to 45% by volume into the chamber.   Furthermore, the manufacturing method of the conductive substrate of Claim 7 or 8 which has an etching process which etches simultaneously about the said copper layer and the said blackening layer.

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