JP6595766B2 - Conductive substrate and method for manufacturing conductive substrate - Google Patents

Description

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

  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 conventionally used. (See Patent Document 1)

  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. 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.

  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.

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

  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 copper layer and a blackening layer that can be etched simultaneously.

In order to solve the above problems, in one aspect of the present invention,
A transparent substrate;
A copper layer formed on at least one surface of the transparent substrate;
It is formed on at least one surface side of the transparent base material and is composed of oxygen, nitrogen, copper, nickel and tungsten, and contains tungsten when the content of copper, nickel and tungsten is 100 atomic%. the amount to provide a conductive substrate and a blackening layer is not more than 1 0 atomic% or more 1 atomic%.

  ADVANTAGE OF THE INVENTION According to this invention, the electroconductive board | substrate provided with the copper layer which can perform an etching process simultaneously, and the blackening layer can be provided.

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. The figure which shows the wavelength dependence of the reflectance of the electroconductive board | substrate of Experimental example 3-1.

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 formed on at least one side of the transparent substrate;
A structure including a blackened layer (hereinafter also simply referred to as “blackened layer”) formed on at least one surface side of the transparent substrate and containing oxygen, nitrogen, copper, nickel, and tungsten. it can.

  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.

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

  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.

  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.

  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 copper layer and 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 substrate or a blackened layer by a dry plating method, and the copper thin film layer can be used as a copper 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, the thickness of the copper layer is preferably 3 μm or less, more preferably 700 nm or less, and even more preferably 200 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, nitrogen, copper, nickel and tungsten 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, 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. Accordingly, the inventors of the present invention have studied, and the layer containing oxygen, nitrogen, copper, nickel and tungsten is black, so it can be used as a blackening layer, and has sufficient reactivity with the etching solution. Thus, the inventors have 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. However, since the blackening layer can be formed relatively easily, it is preferable to form the film by sputtering.

  The blackening layer is, for example, a mixed sintered target of copper, nickel and tungsten, or a target of a copper-nickel-tungsten alloy (hereinafter, these ternary metal targets are also referred to as “copper-nickel-tungsten targets”). The film can be formed by sputtering while supplying oxygen and nitrogen into the chamber.

  Alternatively, a copper-nickel alloy target and a tungsten target may be used, or a copper target and a nickel-tungsten alloy target may be used to form a film by a dual simultaneous sputtering method while supplying oxygen and nitrogen into the chamber. You can also.

  Here, one structural example of the manufacturing method of a copper-nickel-tungsten mixed sintering target is demonstrated. Since copper and tungsten are difficult to melt and do not dissolve, it is preferable to produce a sintered body of a mixed powder of copper, nickel and tungsten by hot pressing or hot isostatic pressing (HIP). And after processing the obtained sintered compact into a predetermined shape, it can affix on a backing plate and can be used as a target.

  The sintering temperature is preferably 850 ° C. or higher and 1083 ° C. or lower, more preferably 950 ° C. or higher and 1050 ° C.

  This is because if the temperature is lower than 850 ° C., the sintering does not proceed sufficiently, so the density of the sintered body is low, and 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.

  A configuration example of a method for producing a copper-nickel-tungsten alloy target will be described. The copper-nickel-tungsten alloy target can be produced, for example, by dissolving a mixed powder of copper, nickel, and tungsten to produce an ingot, and processing the obtained ingot into a desired shape. . In addition, as a raw material, it is not limited to a single metal, The alloy containing each component, such as a nickel-copper alloy, can also be used.

  In addition, the manufacturing method of a copper-nickel-tungsten mixed sintering target or a copper-nickel-tungsten alloy target is not limited to the above manufacturing method. Any method can be used as long as it can be produced so as to be a target having a desired composition.

  Although the supply ratio of oxygen and nitrogen supplied into the chamber is not particularly limited, oxygen is supplied into the chamber at a rate of 5% to 35% by volume and nitrogen is supplied at a rate of 30% to 70% by volume. However, it is preferable to form a film by a sputtering method.

  As described above, by setting the ratio of oxygen supply to the chamber to 5% 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 7% by volume or more. In addition, the reactivity of the blackening layer with respect to the etching solution can be particularly increased by setting the oxygen supply amount to 35% by volume or less. When etching is performed together with the copper layer, the copper layer and the blackening layer are obtained. A desired pattern can be easily formed, which is preferable. The supply ratio of oxygen into the chamber is more preferably 20% by volume or less.

  Nitrogen can be easily etched by adding it to the atmosphere when forming the blackened layer, but if the amount added is too large, the black may become thin and the performance as a blackened layer may be reduced. is there. For this reason, the supply ratio of nitrogen during sputtering is preferably 30% by volume or more and 70% by volume or less, and more preferably 35% by volume or more and 45% by volume or less. Note that it is preferable to set the nitrogen supply ratio to 70% by volume or less because the sputtering rate of the blackened layer can be secured.

  Note that when sputtering is performed, the gas supplied into the chamber is preferably an inert gas for the remainder other than oxygen and nitrogen. For the remainder other than oxygen and nitrogen, 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 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.

  Further, as described above, for example, a copper-nickel-tungsten target can be used as a target used when performing sputtering. Although the composition of the target is not particularly limited as described above, the copper-nickel-tungsten target preferably contains copper in a proportion of 5 atomic% to 50 atomic%, and tungsten is 2 atomic% to 10 atomic%. It is preferable to contain in the ratio. In these cases, the balance can be made of nickel.

The formed blackening layer contains oxygen, nitrogen, copper, nickel, and tungsten. When the total content of copper, nickel, and tungsten is 100 atomic%, the tungsten content is it is preferable 1 atomic% or more 1 is 0 atomic% or less.

  This is because the reflectance of light can be particularly reduced when the content of tungsten in the metal element contained in the blackened layer is 1 atomic% or more. In addition, when the content of tungsten in the metal element contained in the blackened layer is 10 atomic% or less, a high etching property is exhibited and a conductive substrate having a desired pattern can be easily manufactured. .

In the formed blackened layer, oxygen, nitrogen, copper, nickel and tungsten may be contained in any form. For example, copper and tungsten may form a mixed sintered body, and a copper tungsten mixed sintered body containing oxygen and / or nitrogen may be contained in the blackened layer. Further, copper, nickel or tungsten is, for example, copper oxide (Cu ₂ O, CuO, Cu ₂ O ₃ ), copper nitride (Cu ₃ N), nickel oxide (NiO), nickel nitride (Ni ₃ N), tungsten oxide (WO ₃ , WO ₂ , W ₂ O ₃ ), tungsten nitride (W ₂ N, WN), CuWO ₄ , Cu ₂ WO _{5 and} other oxides or nitrides are produced, and the compound is contained in the blackening layer. Also good.

  The blackening layer may be a layer composed of only one kind of material containing oxygen, nitrogen, copper, nickel and tungsten simultaneously, such as a copper-nickel-tungsten mixture containing oxygen and nitrogen. Good. Also, for example, the above-described copper tungsten mixed sintered body containing oxygen and / or nitrogen, copper oxide, copper nitride, nickel oxide, nickel nitride, tungsten oxide, tungsten nitride It may be a layer containing one or more substances selected from

  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 that it is 30 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 60 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.

Then, in order to form the contact portion of the electrical member of a circuit such as a blackening layer, the sheet resistance of the black layer is preferably 2.00 × 10 ^-1 Ω / □ or less.

  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 base material, a copper layer, and a blackening layer containing oxygen, nitrogen, copper, nickel, and tungsten. 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.

  A specific configuration example will be described below with reference to FIGS. 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, as in the conductive substrate 10A shown in FIG. 1A, the copper layer 12 and the blackening layer 13 can be laminated one layer at a time on the one surface 11a side of the transparent base material 11. . Moreover, like the electroconductive board | substrate 10B shown in FIG.1 (b), copper layer 12A, 12B on the one surface 11a side of the transparent base material 11, and the other surface (other surface) 11b side, respectively. 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), (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, as in the conductive substrate 20B shown in FIG. 2B, 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 serves as a symmetrical surface and the top and bottom of the transparent base material 11 are aligned. Although the example which arrange | positioned so that the laminated | stacked layer might become symmetrical 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 substrate 11 is formed by laminating the copper layer 12 and the blackening layer 13 in that order, similarly to the configuration of FIG. The layers laminated on the top and bottom of the transparent substrate 11 may be asymmetrical.

  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 the present embodiment is not particularly limited. For example, the conductive substrate of the present embodiment has a reflectivity when irradiated with light having a wavelength in the range of 350 nm to 780 nm. The average reflectance of visible light, which is an average value of is preferably 35% or less, more preferably 20% or less, and particularly preferably 10% or less. This is preferable when the average reflectance of the visible light is 35% or less, for example, even when used as a conductive substrate for a touch panel, 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. 1A, the blackened layer 13 can be irradiated with light. It can be measured from the surface side indicated by middle A.

  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 base material 11, The reflectance can be measured from the surface 11b side of the transparent substrate 11, which is the side where the layer 13 is located on the outermost surface excluding the transparent substrate 11.

  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.

  As described above, the conductive substrate of this embodiment 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.

  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 two-layer wiring can be used as a mesh wiring. A specific configuration example is shown in FIG. FIG. 3 shows a view of the conductive substrate 30 provided with 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 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. An example of the arrangement of the transparent substrate 11 and the wiring is shown in FIGS. 4A and 4B correspond to cross-sectional views taken along line AA ′ of FIG.

  First, as shown to Fig.4 (a), 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, 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 may be disposed between the transparent substrate 11A and the transparent substrate 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 any of FIGS. 4A and 4B, the arrangement of the blackening layers 32A and 32B and the wirings 31A and 31B can be reversed upside down. 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. For this reason, in 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 figure, 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.

  The conductive substrate having the mesh-like wiring shown in FIG. 3 and FIG. 4A includes, for example, copper layers 12A and 12B on both surfaces of the transparent substrate 11 as shown in FIG. 1B and FIG. , And blackened layers 13A and 13B (131A, 132A, 131B, and 132B).

  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. 1 (b) means a direction parallel to the width direction of each layer in FIG. 1 (b).

  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 blackened layer 13B on the other surface 11b side of the transparent substrate 11. Etching is performed so that In addition, the Y-axis direction in FIG.1 (b) means the direction perpendicular | vertical to a 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 the mesh-like wiring shown in FIG. 3 can also be formed by using two conductive substrates shown in FIG. 1 (a) or FIG. 2 (a). 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. The surface A in FIG. 1A in which the copper layer 12 or the like is 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 positions of the blackening layers 32A and 32B and the wirings 31A and 31B It is preferable to arrange the positions 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 on which 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. .

  Note that the width of the wiring and the distance between the wirings in the conductive substrate having the mesh-like wiring shown in FIGS. 3 and 4 are not particularly limited, and are selected according to, for example, the amount of current flowing through the wiring. can do.

  3 and 4 show an example in which a mesh-like wiring (wiring pattern) is formed by combining linear wirings, but the present invention is not limited to such a configuration, and a wiring pattern is configured. The wiring can have 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 can have the following processes.

A transparent base material preparation step for preparing a transparent base material.
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, nitrogen, copper, nickel and tungsten on at least one surface side of the transparent substrate.

  Although the manufacturing method of the electroconductive board | substrate of this embodiment is demonstrated below, 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 this 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 in which the copper layer forming step and the blackened layer forming step are performed and the number of times to carry out are not particularly limited, and any number of times and timings may be selected according to the structure of the conductive substrate to be formed. Can be implemented.

  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.

  In addition, since the film which can be used especially suitably as an insulator film which permeate | transmits visible light is already stated, description is abbreviate | omitted here.

  Next, the copper layer forming step 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. Moreover, 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 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.

  Next, the blackening layer forming process will be described.

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

  In the blackening layer forming step, when the blackening layer is formed by sputtering, a copper-nickel-tungsten mixed sintered target or a copper-nickel-tungsten alloy target can be used. Further, as described above, a film can also be formed by a binary simultaneous sputtering method using a copper-nickel alloy target and a tungsten target. Alternatively, a copper target and a nickel-tungsten alloy target can be used to form a film by a binary simultaneous sputtering method.

  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, when a copper-nickel-tungsten target such as a copper-nickel-tungsten mixed sintered target is used as the target, the copper-nickel-tungsten target is tungsten in an amount of 2 atomic% to 10 atomic%, and copper is 5 atomic% or more. It is preferable to contain it in the ratio of 50 atomic% or less. The balance can be made of nickel.

  Further, it is preferable to form a blackened layer by a sputtering method while supplying oxygen in the chamber at a rate of 5% by volume to 35% by volume and nitrogen at a rate of 30% by volume to 70% by volume.

  In particular, the supply ratio of oxygen into the chamber is more preferably 7% by volume or more and 20% by volume or less. Further, the supply ratio of nitrogen into the chamber is more preferably 35% by volume or more and 45% by volume or less.

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

  And as for the electroconductive board | substrate obtained by the manufacturing method of the electroconductive board | substrate demonstrated here, it is preferable that the copper layer is 100 nm or more like the conductive board | substrate mentioned above, and it shall be 150 nm or more. More preferred. The upper limit value of the thickness of the copper layer is not particularly limited, but is preferably 3 μm or less, more preferably 700 nm or less, and further preferably 200 nm or less.

  Also in the conductive substrate obtained by the conductive substrate manufacturing method described here, the thickness of the blackening layer is not particularly limited, but is preferably 20 nm or more, for example, 30 nm or more. It is more preferable. 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 formed blackened layer can contain oxygen, nitrogen, copper, nickel, and tungsten. The content ratio of each component in the blackened layer is not particularly limited, but when the total of copper, nickel and tungsten, which are metal elements contained in the blackened layer, is 100 atomic%, the content of tungsten The amount is preferably 1 atomic% or more and 10 atomic% or less.

  This is because the reflectance of light can be particularly reduced when the content of tungsten in the metal element contained in the blackened layer is 1 atomic% or more. In addition, when the content of tungsten in the metal element contained in the blackened layer is 10 atomic% or less, a high etching property is exhibited and a conductive substrate having a desired pattern can be easily manufactured. .

In the formed blackened layer, oxygen, nitrogen, copper, nickel, and tungsten may be contained in any form. For example, copper and tungsten may form a mixed sintered body, and a copper tungsten mixed sintered body containing oxygen and / or nitrogen may be contained in the blackened layer. Further, copper, nickel or tungsten is, for example, copper oxide (Cu ₂ O, CuO, Cu ₂ O ₃ ), copper nitride (Cu ₃ N), nickel oxide (NiO), nickel nitride (Ni ₃ N), tungsten oxide (WO ₃ , WO ₂ , W ₂ O ₃ ), tungsten nitride (W ₂ N, WN), CuWO ₄ , Cu ₂ WO _{5 and} other oxides or nitrides are produced, and the compound is contained in the blackening layer. Also good.

  The blackening layer may be a layer composed of only one kind of material containing oxygen, nitrogen, copper, nickel and tungsten simultaneously, such as a copper-nickel-tungsten mixture containing oxygen and nitrogen. Good. Also, for example, the above-described copper tungsten mixed sintered body containing oxygen and / or nitrogen, copper oxide, copper nitride, nickel oxide, nickel nitride, tungsten oxide, tungsten nitride It may be a layer containing one or more substances selected from

  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.

Then, in order to form the contact portion of the electrical member of a circuit such as a blackening layer, the sheet resistance of the black layer is preferably 2.00 × 10 ^-1 Ω / □ 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 the 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 on the outermost surfaces A and B of the conductive substrate. The copper layer and the blackened layer formed on both surfaces of the transparent substrate 11 may be etched simultaneously.

  In addition, the copper layer and the blackened layer formed on both sides of the transparent substrate 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.

  Since the blackening layer exhibits the same reactivity to the etching solution as the copper layer, the etching solution used in the etching step is not particularly limited, and an etching solution generally used for etching the copper layer is preferably used. be able to. 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.

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

  The specific form of the mesh-like wiring obtained by the above-described etching process is as described above, and the 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 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 of the present embodiment have been described above. In such a conductive substrate or a conductive substrate obtained by the method for manufacturing a conductive substrate, the copper layer and the blackened layer have substantially the same reactivity with the etching solution, and can be etched at the same time. For this reason, wiring of a desired shape 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.

  EXAMPLES The present invention will be described in more detail below with reference to 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)

(Evaluation methods)
(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 measurement was performed by installing a reflectance measurement unit in an ultraviolet-visible spectrophotometer (manufactured by Hitachi High-Technologies Corporation: U-4000).

  In Experimental Examples 2 and 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, the incident angle is 5 ° and the light receiving angle is 5 °, and the wavelength ranges from 350 nm to 780 nm. The reflectance when irradiated with light 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 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 average 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 samples of each experimental example and comparative example were placed on a glass substrate and fixed with a clamp, and the measurement was performed by irradiating light from the blackened layer side.

In addition, using the measured reflectance, conforming to JIS Z8781-4: 2013 “Using the color calculation program, the condition of the light source A field of view of 2 degrees on the CIE 1976 (L ^* , a ^* , b ^* ) color space Coordinates were calculated.
(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.

  Moreover, the conductive substrate produced in Experimental Examples 2 and 3 was immersed in an etching solution, and a dissolution test of the copper layer and the blackened layer was performed.

  As an etching solution, an aqueous solution containing 10% by mass of ferric chloride, 10% by mass of hydrochloric acid, and the balance water was used in any dissolution test, and the temperature of the etching solution was room temperature (25 ° C.).

  Next, 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 in any of the above etching solutions.

  For this reason, in Experimental Example 1, the case where the entire blackened layer was dissolved within 10 seconds after immersion in the etching solution was ◎, the case where the entire blackened layer was dissolved within 30 seconds was ○, and the blackened within 1 minute. The case where the entire layer was dissolved ◇, the case where the entire blackened layer was dissolved within 3 minutes, the case where the entire blackened layer was not dissolved even after 3 minutes, and the case where a part remained was evaluated as x. .

In Experimental Examples 2 and 3, after immersing the conductive substrate in the etching solution for 1 minute, the conductive substrate was taken out of the etching solution, and the copper layer and the blackened layer were completely dissolved. When it was, it was evaluated as ◎. If the copper layer or blackened layer remains when removed from the etchant, immerse in the same etchant for another minute and completely dissolve the copper layer and blackened layer when removed from the etchant. However, when it was only a transparent substrate, it was evaluated as ◯. When the copper layer or the blackened layer remained even after the second immersion in the etching solution, it was evaluated as x.
(3) EDS analysis About the sample which formed the blackening layer on the transparent base material produced in Experimental example 1, and the electroconductive board | substrate produced in Experimental example 3, SEM-EDS apparatus (SEM: JEOL Co., Ltd. make 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) Sheet resistance The sheet resistance was evaluated for the sample in which only the blackened layer was formed on the transparent substrate prepared in Experimental Examples 2 and 3.

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, a four-probe measuring device (Mitsubishi Chemical Co., Ltd. model: Loresta IP) was used, and the measurement was performed by arranging four needle-shaped electrodes on the surface of the blackened layer.
(Sample preparation conditions)
The sample manufacturing conditions and the evaluation results in each experimental example will be described below.
[Experimental Example 1]
In Experimental Example 1, five samples of Experimental Example 1-1 to Experimental Example 1-5 were prepared under the conditions shown in Table 1 below, and an EDS analysis and a dissolution test were performed on the composition of the blackened layer. did.

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 1-5)
In order to evaluate the blackened layer, samples (Experimental Examples 1-1 to 1-5) in which a blackened layer containing oxygen, nitrogen, copper, nickel, and tungsten was formed on a polyethylene terephthalate substrate were prepared. A specific procedure will be 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 5 cm, a width of 5 cm, and a thickness of 0.05 mm was prepared.

  Next, a blackening layer was formed by direct current sputtering.

  The blackening layer 13 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 below.

  Two targets, a copper target and a nickel-7 at% tungsten alloy 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, argon gas, nitrogen gas, and oxygen gas were supplied into the chamber so that the total amount became 10 SCCM. Sputtering was performed while supplying each volume% of argon, nitrogen, and oxygen of the gas supplied into the chamber at the ratio shown in Table 1.

  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, nitrogen 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 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 (Pa) 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 n of the target composition as tungsten and the balance as 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 five 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 1-5, 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: N ₂ : O ₂ = 5.0: 4.0: 1.0). is there.

  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. : 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 of the blackened layers formed in Experimental Examples 1-1 to 1-5 contained copper, nickel, tungsten, nitrogen, and oxygen.

  That is, a blackening layer containing oxygen, nitrogen, copper, nickel, and tungsten is formed by a binary co-sputtering method using a copper target and a nickel-7 at% tungsten alloy target while supplying nitrogen and oxygen. It was confirmed that the film could be formed.

(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. The results are shown in Table 2.

表２に示した結果によれば、いずれの実験例においても溶解試験の結果は◎となっており、１０秒以内に黒化層が溶解することを確認できた。すなわち、これらの実験例の黒化層は、銅層と同等の溶解性を示すことが確認できた。

According to the results shown in Table 2, the result of the dissolution test was “◎” in any of the experimental examples, and it was confirmed that the blackened layer was dissolved within 10 seconds. That is, it was confirmed that the blackened layer of these experimental examples showed the same solubility as the copper layer.

  From the above results, when the blackened layer produced in Experimental Example 1-1 to Experimental Example 1-5 is formed on a copper layer to form a conductive substrate, the copper layer and the blackened layer are formed when patterning is performed. It was confirmed that the etching process can be performed simultaneously. For this reason, the conductive substrates of Experimental Example 2-1 to Experimental Example 2-5 prepared in Experimental Example 2 to be described later have a conductive layer including a copper layer that can be etched simultaneously and a blackening layer. It was confirmed that the substrate was a conductive substrate.

[Experimental example 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 substrate was produced. As the conductive substrate, as shown in Table 3, seven types of samples with different film formation conditions for the blackened layer were prepared. In Experimental Example 2-1 to Experimental Example 2-5, the blackened layer is formed under the same conditions as Experimental Example 1-1 to Experimental Example 1-5 except that the film thickness is different.

  Experimental Examples 2-1 to 2-7 described below are examples.

  Below, the preparation procedure of the electroconductive board | substrate of Experimental example 2-1 to Experimental example 2-7 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 (transparent substrate preparation step).

  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 a binary simultaneous sputtering method (blackened layer forming step).

  In Experimental Example 2-1 to Experimental Example 2-5, 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 1-5. In addition, the blackening layer was formed so that it might become the film thickness shown in Table 3 about each experiment example.

  Moreover, about Experimental example 2-6 and Experimental example 2-7, when performing sputtering, the ratio of the DC power applied to each target, the ratio of the gas component supplied into the chamber, and the thickness of the blackening layer are set. A blackened layer was formed in the same manner as in Experimental Example 2-1, except that the values shown in Table 2 were changed.

  As shown in Table 3, the blackening layer 13 having a thickness of about 30 nm to 60 nm was formed by the sputtering method.

  Moreover, the sample for sheet resistance measurement was produced about each experiment example on the same conditions except the point which formed the blackening layer directly on the transparent base material, without forming a copper layer.

About the electroconductive board | substrate obtained by the above process, the dissolution test and evaluation of optical characteristic evaluation (reflectance measurement, lightness calculation) were implemented. Moreover, sheet resistance was evaluated about the sample for sheet resistance measurement. The evaluation result will be described.
(Evaluation of dissolution test)
A dissolution test of the produced conductive substrate was performed.

  About the dissolution test, it evaluated by the above-mentioned method and evaluation criteria.

The dissolution test results are summarized in Table 4.
(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 shown in Table 4.
(Evaluation of sheet resistance)
Sheet resistance was evaluated for a sheet resistance measurement sample prepared in each experimental example, that is, a sample in which only a blackened layer was formed on the transparent base material under the same conditions as when the conductive substrate was manufactured. The results are shown in Table 4.

  From Table 4, the dissolution test result of any sample of Experimental Example 2-1 to Experimental Example 2-7 is ◎, and it can be confirmed that this is a conductive substrate capable of simultaneously etching the blackened layer and the copper layer. It was. It was confirmed that this result was consistent with the result of the dissolution test of Experimental Example 1.

  Further, from Table 4, from the optical property evaluation results of any sample of Experimental Example 2-1 to Experimental Example 2-7, the reflectance at 550 nm is approximately 30% or less and the visible light average reflectance is also sufficiently small at 35% or less. I understood that.

  That is, it was confirmed that reflection on the copper layer surface could be suppressed even when the copper layer and the blackened layer were patterned and used for applications such as a touch panel.

  From Table 4, it was confirmed that the surface resistance (sheet resistance) of the blackened layer was sufficiently small in any of the experimental examples 2-1 to 2-7.

[Experiment 3]
In Experimental Example 3, a Cu—Ni—W alloy target was prepared, 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. In Table 5, this composition is shown as Ni7W10Cu.

  Conductivity having the 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 5, two types of samples having different film formation conditions for the blackened layer were prepared. Experimental Example 3-1 and Experimental Example 3-2 described below are examples.

  The procedure for producing the conductive substrates of Experimental Example 3-1 and Experimental Example 3-2 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 (transparent substrate preparation step).

  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 5 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 to have the film thickness shown in Table 5 for each experimental example, and a conductive substrate was manufactured.

  Moreover, the sample for sheet resistance measurement was produced about each experiment example on the same conditions except the point which formed the blackening layer directly on the transparent base material, without forming a copper layer.

  Table 5 shows the results of EDS analysis performed on the surface of the produced conductive substrate on the blackened layer side.

  About the electroconductive board | substrate obtained by producing on above-mentioned conditions, the dissolution test and evaluation of optical characteristic evaluation (reflectance measurement, brightness, chromaticity calculation) were implemented. Moreover, sheet resistance was evaluated about the sample for sheet resistance measurement. The results are shown in Table 6.

  Moreover, the graph of the wavelength dependence of a reflectance about the electroconductive board | substrate of Experimental example 3-1 is shown in FIG.

  As is apparent from the results of FIG. 5 and Table 6, it was confirmed that Experimental Example 3-1 had a particularly low reflectance in the entire visible light region. Also in Experimental Example 3-2, it was confirmed that the entire visible light region had a low reflectance and the reflectance with respect to light having a wavelength of 550 nm was also low.

In addition, as shown in Table 6, Experimental Example 3-1 and Experimental Example 3-2 have low lightness L ^* values, negative chromaticity a ^* values and b ^* values, and are good as blackening layers. It was confirmed that the optical properties were excellent. It was confirmed that the etching property (dissolution test) and the conductivity (sheet resistance) both showed good evaluation results as a blackened layer.

From the above, the conductive substrate provided with the copper layer and the blackening layer containing oxygen, nitrogen, copper, nickel, and tungsten on at least one surface side of the transparent base material of the present invention is etched simultaneously. It was confirmed that the substrate was a conductive substrate provided with a copper layer capable of performing the above and a blackened layer. That is, it has been confirmed that the conductive substrate is superior in etching property than the conventional one. Moreover, since the electroconductive board | substrate which concerns is low brightness, it has confirmed that it could be used conveniently as an electroconductive board | substrate for touchscreens.

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 (6)

A transparent substrate;
A copper layer formed on at least one surface of the transparent substrate;
It is formed on at least one surface side of the transparent base material and is composed of oxygen, nitrogen, copper, nickel and tungsten, and contains tungsten when the content of copper, nickel and tungsten is 100 atomic%. And a blackened layer having an amount of 1 atomic% or more and 10 atomic% or less. 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 or more.   The conductive substrate according to claim 1 or 2, wherein a visible light average reflectance in a wavelength range of 350 nm or more and 780 nm or less is 35% or less.   The electroconductive board | substrate as described in any one of Claims 1 thru | or 3 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;
At least one surface side of the transparent substrate is composed of oxygen, nitrogen, copper, nickel, and tungsten, and when the content of copper, nickel, and tungsten is 100 atomic%, the content of tungsten is A blackening layer forming step of forming a blackening layer of 1 atomic% or more and 10 atomic% or less. The blackening layer forming step includes
Using a copper-nickel-tungsten alloy target,
6. The conductivity according to claim 5, wherein the blackened layer is formed by a sputtering method while supplying oxygen in a ratio of 5% by volume to 35% by volume and nitrogen in a ratio of 30% by volume to 70% by volume in the chamber. A method for manufacturing a substrate.

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