JP6365422B2 - Method for manufacturing conductive substrate - Google Patents

Description

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

  As disclosed in Patent Document 1, a transparent conductive film for a touch panel in which an ITO film is formed as a transparent conductive film on a polymer film has been conventionally used.

  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 instead of the ITO film has been studied. However, 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, a conductive substrate in which a blackening layer made of a black material is formed together with a wiring layer made of a metal foil such as copper has been studied. 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 with respect to 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 above-described problems of the related art, an object of one aspect of the present invention is to provide a method for manufacturing a conductive substrate including a copper layer and a blackened layer that can be etched simultaneously.

In order to solve the above problems, one embodiment of the present invention provides:
A transparent substrate preparation step of preparing a transparent substrate;
A copper layer forming step of forming a copper layer on at least one surface side of the transparent substrate;
A blackened layer forming step of forming a blackened layer on at least the one surface side of the transparent substrate,
In the blackening layer forming step, using a target containing nickel oxide and tungsten oxide, containing tungsten oxide in a proportion of 10% by mass or more and 30% by mass or less, and the balance being the nickel oxide, Provided is a method for manufacturing a conductive substrate in which the blackening layer is formed in an atmosphere containing nitrogen .

According to one embodiment of the present invention, a method for manufacturing a conductive substrate including a copper layer and a blackened layer that can be etched simultaneously 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.

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 surface side of the transparent base material, and a blackening layer formed on at least one surface side of the transparent base material. Can be configured.

  The blackening layer can contain oxygen, nitrogen, nickel, and tungsten. The blackening layer can be formed using a target containing nickel oxide and tungsten oxide and containing tungsten oxide in a proportion of 5% by mass to 30% by mass.

  In addition, the conductive substrate in the present embodiment is a substrate in which a substrate having a copper layer or a blackened layer on the surface of the transparent base material before patterning the copper layer or the like and a copper layer or the like are patterned into a wiring shape, That is, a wiring board is included.

  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 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. The copper layer is not particularly limited. However, in order not to reduce the light transmittance, the copper layer and the transparent substrate or the copper layer and a layer containing oxygen, nitrogen, nickel, and tungsten (hereinafter simply referred to as “black”). It is desirable that no adhesive be placed between the adhesive layer and the layer. That is, the copper layer is preferably formed directly on the upper surface of another member.

  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. That is, the copper layer may have a copper thin film layer and a copper plating layer. 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 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 blackened layer will be described. Since the copper layer has a metallic luster, the copper reflects light as described above 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, the display is visually recognized. There was a problem that the performance decreased.

  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 since the layer containing oxygen, nitrogen, nickel, and tungsten is black, 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, which is a layer containing oxygen, nitrogen, nickel, and tungsten, 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 can be formed by a sputtering method using a target containing nickel oxide and tungsten oxide, which is made from a mixture of nickel oxide and tungsten oxide.

  When the blackening layer is formed by sputtering, it can be formed while supplying oxygen and nitrogen, or only nitrogen, as reactive gases in the chamber. The supply ratio of oxygen and nitrogen supplied into the chamber is not particularly limited, but a gas containing oxygen in a ratio of 0 to 20% by volume and nitrogen in a ratio of 30 to 70% by volume is contained in the chamber. It is preferable to form a film by a sputtering method while supplying to the substrate.

  This is because when the oxygen supply ratio in the gas supplied into the chamber is 20% by volume or less, the reactivity of the blackening layer with respect to the etching solution can be particularly improved. This is because the desired pattern can be more easily formed between the layer and the blackened layer. As described above, since the target containing nickel oxide and tungsten oxide when forming the blackened layer contains oxygen, the target into the chamber when forming the blackened layer is contained. The oxygen supply ratio is more preferably 0% by volume to 10% by volume.

  Supplying nitrogen into the chamber when depositing the blackened layer makes it easier to etch the blackened layer, but if the supply ratio increases too much, the blackened layer becomes darker and blackened. There is a possibility that the performance as a layer is lowered. Moreover, when the supply ratio of nitrogen increases too much, the sputtering rate from the target may be reduced. For this reason, the supply ratio of nitrogen in the gas supplied into the chamber during sputtering is preferably 30% by volume to 70% by volume, and more preferably 35% by volume to 40% by volume.

  A nitrogen supply ratio of 30% by volume or more is preferable because the formed blackened layer is more easily etched.

  Moreover, the sputtering rate of the target containing nickel oxide and tungsten oxide can be secured by setting the nitrogen supply ratio to 70% by volume or less, and reflection of light can be sufficiently suppressed for the formed blackened layer. It is preferable because it can be colored. Further, it is more preferable to supply nitrogen into the chamber so that the supply ratio of nitrogen is 40% by volume or less because the sputtering rate is particularly improved.

  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, argon or helium can be supplied.

  So far, the method for forming a layer containing oxygen, nitrogen, nickel, and tungsten using a target containing nickel oxide and tungsten oxide has been described; however, the present invention is not limited to such a mode. For example, a layer containing oxygen, nitrogen, nickel, and tungsten can be formed by a sputtering method using a nickel-tungsten alloy target while supplying nitrogen and oxygen into the chamber.

  By the way, it is preferable that the blackening layer has both characteristics of reflectance and etching. That is, it is preferable that the blackened layer has a low reflectance and has a high etching property. According to the study by the inventors of the present invention, the reflectance and the etching property are affected by the contents of oxygen and nitrogen in the formed blackened layer. The contents of oxygen and nitrogen in the blackened layer are affected by the amount of gas supplied into the chamber during sputtering.

  When forming a blackening layer using a nickel-tungsten alloy target as described above, the content of oxygen and nitrogen in the blackening layer is controlled in order to obtain a blackening layer that is uniform and has both the above characteristics. In this case, it is necessary to control the ratio of nitrogen and oxygen in the chamber with high accuracy.

  On the other hand, in the case of a target containing nickel oxide and tungsten oxide, the target contains oxygen. For this reason, in order to obtain a blackened layer that is uniform and has both of the above characteristics using such a target, when controlling the contents of oxygen and nitrogen in the blackened layer, the inside of the chamber during sputtering is substantially nitrogen. Can be controlled. Therefore, when forming a blackening layer using a target containing nickel oxide and tungsten oxide, the ratio of oxygen and nitrogen in the blackening layer can be controlled relatively easily, A blackened layer having excellent reflectance and etching property can be produced.

  Therefore, as described so far, the blackening layer that is a layer containing oxygen, nitrogen, nickel, and tungsten is preferably formed using a target containing nickel oxide and tungsten oxide.

  The composition of the target containing nickel oxide and tungsten oxide is not particularly limited. For example, it is preferable to contain tungsten oxide in a proportion of 5 wt% to 30 wt%, and tungsten oxide is 15 wt% or more. More preferably, it is contained in a proportion of 25% by weight or less. In these cases, for example, the remainder can be made of nickel oxide. For this reason, the target containing nickel oxide and tungsten oxide can be a target made of nickel oxide and tungsten oxide. However, even in these cases, it is not excluded that unavoidable components such as a binder used for producing the target are included.

  Note that a target containing nickel oxide and tungsten oxide can be manufactured by sintering a mixture of nickel oxide and tungsten oxide. However, when the content of tungsten oxide increases, the sinterability of the target may decrease. That is, it may be difficult to target. However, when the tungsten oxide content is 30% by weight or less, it is preferable because the sinterability is sufficiently high and can be easily targeted.

  Moreover, according to examination of the inventors of this invention, the adhesiveness of a transparent base material, a copper layer, and a blackening layer can be improved as content of the tungsten oxide in a target increases. And by making content of the tungsten oxide in a target into 5 weight% or more, the adhesiveness of the blackening layer produced using this target and a transparent base material or a copper layer can fully be improved. Therefore, it is preferable.

In the formed blackened layer, oxygen, nitrogen, nickel and tungsten may be contained in any form. Nickel or tungsten is, for example, oxide or nitride such as nickel oxide (NiO), nickel nitride (Ni ₃ N), tungsten oxide (WO ₃ , WO ₂ , W ₂ O ₃ ) or tungsten nitride (W ₂ N, WN). And the compound may be contained in the blackened layer.

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

  In particular, in the blackened layer, the main phase identified from the diffraction pattern obtained by X-ray diffraction is preferably nickel nitride.

  The thickness of the blackened layer is not particularly limited, but is preferably 20 nm or more, and more preferably 30 nm or more. This is because light reflection may not be sufficiently suppressed when the blackening layer is thin. On the other hand, it is preferable to make the thickness of the blackened layer in the above range because reflection of light on the surface of the copper layer can be more reliably suppressed.

  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.

  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. 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.

  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.

  Thus, the blackening layer 13 (13A, 13B) and the copper layer 12 (12A, 12B) can be laminated in this order from the transparent substrate 11 side. Thus, when the blackening layer 13 is arrange | positioned between the transparent base material 11 and the copper layer 12, since the adhesiveness of the transparent base material 11 and the copper layer 12 can be improved with the blackening layer 13, it is preferable. For example, also in the case of having the structure shown in FIG. 2A described later, the first blackening layer 131 can improve the adhesion between the transparent base material 11 and the copper layer 12 for the same reason.

  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, a copper layer on the transparent substrate, and a blackened layer that can suppress reflection of light on the surface of the copper layer; Therefore, reflection of light by the copper layer can be suppressed.

  The degree of light reflection of the conductive substrate of the present embodiment is not particularly limited, but for example, the conductive substrate of the present embodiment preferably has a reflectance of light having a wavelength of 550 nm of 40% or less. 30% or less is more preferable, and 20% or less is particularly preferable. 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 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.

  Further, in the case of FIG. 1A, the arrangement of the copper layer 12 and the blackened layer 13 is changed, and when 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 blackened layer 13 is located on the outermost surface except for the material 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 blackening layer remains 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 have a 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, 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.

  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 base materials 11A and 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.

  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. 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 blackened layer forming step of forming a blackened layer on at least one surface side of the transparent substrate.

  In the blackening layer forming step, an atmosphere containing nitrogen using a target containing nickel oxide and tungsten oxide and containing tungsten oxide in a proportion of 5% by mass to 30% by mass. The blackening layer can be formed therein.

  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 of the copper layer forming step and the blackened layer forming step and the number of times of execution are not particularly limited, and are performed at an arbitrary number of times according to the structure of the conductive substrate to be formed. be able to.

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

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

  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 more preferable to use the sputtering method because the film thickness can be easily controlled.

  The process of forming a copper thin film layer will be described taking the case of using a winding type sputtering apparatus as an example. First, a copper target is mounted on a sputtering cathode, and a base material, specifically a transparent base material, a transparent base material with a blackened layer, or the like is set in a vacuum chamber. After evacuating the inside of the vacuum chamber, Ar gas is introduced to maintain the inside of the apparatus at about 0.13 Pa to 1.3 Pa. In this state, 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.

  At this time, a target containing nickel oxide and tungsten oxide can be used as the target. The composition of the target containing nickel oxide and tungsten oxide is not particularly limited. For example, it is preferable to contain tungsten oxide in a proportion of 5% by mass to 30% by mass, and tungsten oxide is 15% by mass or more. More preferably, it is contained in a proportion of 25% by mass or less. In these cases, the balance can be composed of nickel oxide.

  Further, in forming the blackened layer by sputtering in the blackened layer forming step, the blackened layer can be formed while supplying nitrogen and oxygen or only nitrogen into the chamber as a reactive gas. The supply ratio of oxygen and nitrogen supplied into the chamber is not particularly limited, but a gas containing oxygen in a ratio of 0 to 20% by volume and nitrogen in a ratio of 30 to 70% by volume is contained in the chamber. It is preferable to form a film by a sputtering method while supplying to the substrate.

  In particular, since oxygen is contained in the target when forming the blackened layer, the supply ratio of oxygen into the chamber when forming the blackened layer is 0% by volume or more and 10% by volume or less. More preferably. Further, the supply ratio of nitrogen supplied into the chamber at the time of sputtering is more preferably 35% by volume or more and 40% 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, argon or helium can be supplied.

In the formed blackened layer, oxygen, nitrogen, nickel and tungsten may be contained in any form. Nickel or tungsten is, for example, oxide or nitride such as nickel oxide (NiO), nickel nitride (Ni ₃ N), tungsten oxide (WO ₃ , WO ₂ , W ₂ O ₃ ) or tungsten nitride (W ₂ N, WN). And the compound may be contained in the blackened layer.

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

  In particular, in the blackened layer, the main phase identified from the diffraction pattern obtained by X-ray diffraction is preferably nickel nitride.

  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.

  Furthermore, the conductive substrate obtained by the conductive substrate manufacturing method described herein preferably has a light reflectance of 550 nm of 40% or less, more preferably 30% or less, and 20% or less. It is particularly preferred that

  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 wt% to 50 wt%, and preferably 10 wt%. More preferably, it is contained in a proportion of 30% by weight or less. Further, for example, the etching solution preferably contains hydrochloric acid in a proportion of 1 wt% or more and 50 wt% or less, and more preferably contains 1 wt% or more and 20 wt% 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 to 50 ° C.

  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.

  3 and 4 show examples of mesh-like wirings in which wirings patterned in a linear shape are combined. However, the present invention is not limited to such a form. The wiring constituting the wiring pattern, that is, the shape of the patterned copper layer can be 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.

  The conductive substrate and the method for manufacturing the conductive substrate of the present embodiment 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. In addition, since the layer containing oxygen, nitrogen, nickel, and tungsten is black, it functions as a blackened layer and can suppress reflection of light by the copper layer. For example, when a conductive substrate for a touch panel is used. , Visibility can be suppressed.

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

First, the evaluation method of the sample produced in each Example mentioned later and a comparative example is demonstrated.
(Evaluation method)
(1) Reflectance Measurement was performed by installing a reflectance measurement unit in an ultraviolet-visible light spectrophotometer (manufactured by Shimadzu Corporation, model number: UV-2550).

In the following Examples 1 to 6 and Comparative Examples 1 and 2, the cross-sectional shape has the same structure as FIG. 1A except that the stacking order of the copper layer 12 and the blackened layer 13 is reversed. A conductive substrate was produced. That is, a conductive substrate was prepared by laminating the blackened layer 13 and the copper layer 12 in this order from the transparent base material 11 side. Therefore, in the produced conductive substrate, the blackening layer 13 is located on the outermost surface side excluding the transparent base material 11, and the incident angle is 5 ° with respect to the blackening layer 13 and the light receiving angle 5. The reflectance when irradiated with light having a wavelength of 550 nm was measured.
(2) Dissolution test The conductive substrate produced in each Example and the comparative example was immersed in etching liquid, and the dissolution test of the copper layer and the blackening layer was done. Etching liquid is 10% by weight of ferric chloride and 10% by weight of hydrochloric acid. An aqueous solution of the balance was used, and the temperature of the etching solution was room temperature (25 ° C.).

After immersing 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 and only a transparent substrate 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 only the transparent substrate was used, it was evaluated as Δ. When the copper layer or the blackened layer remained even after the second immersion in the etching solution, it was evaluated as x.
(Sample preparation conditions)
The manufacturing conditions of the conductive substrate in each example and comparative example are shown below.
[Example 1]
A conductive substrate having a structure equivalent to the structure shown in FIG. 1A was produced except that the stacking order of the copper layer 12 and the blackened layer 13 was reversed. That is, the stacking order of each layer is the order of the blackening layer 13 and the copper layer 12 from the transparent substrate 11 side.

  A specific procedure for manufacturing a conductive substrate will be described below.

  First, a transparent substrate made of polyethylene terephthalate resin (PET) having a length of 5 cm, a width of 5 cm, and a thickness of 0.02 mm was prepared (transparent substrate preparation step).

  A blackened layer was formed on one surface of the transparent substrate using a target composed of nickel oxide and tungsten oxide in an atmosphere containing oxygen and nitrogen (blackened layer forming step).

  The blackening layer forming step was performed using a sputtering apparatus (Model: CFS-4ES-2 manufactured by Shibaura Mechatronics Co., Ltd.). Moreover, the target which contains tungsten oxide 10 mass% as a target and the remainder consists of nickel oxide was used.

  First, the transparent base material was installed in the chamber so as to face the target and the distance between the target and the transparent base material was 85 mm.

Next, after setting the transparent substrate in the chamber, the chamber was evacuated. The ultimate vacuum in the chamber before sputtering was 1 × 10 ⁻³ Pa.

  Then, sputtering was performed while rotating the transparent substrate at 15 rpm.

  During sputtering, nitrogen and argon were supplied into the chamber so that the total amount was 15 sccm. Each gas was supplied to the chamber so that nitrogen was 30% by volume, oxygen was 20% by volume, and the balance was argon, and sputtering was performed. Further, when the blackening layer was formed by sputtering, a current of 0.42 A and a voltage of 476 V (power value of about 200 W) were applied to the target by a DC power source.

  A blackened layer having a thickness of 30 nm was formed according to the above procedure and conditions.

  After forming the blackened layer, the main phase of the blackened layer was confirmed by an X-ray diffractometer (manufactured by Bruker AXS, model number: D8 DISCOVER μ-HR). The results are shown in Table 1.

  Next, a copper layer was formed on one surface of the transparent substrate, here the upper surface of the blackened layer (copper layer forming step).

  The copper layer was formed by sputtering using a copper target so that the film thickness of the copper thin film layer was 200 nm on the substrate on which the blackened layer was formed. When forming the copper thin film layer, 100% by volume of argon was supplied to the chamber, the substrate rotation speed was 15 rpm, and sputtering was performed with a DC power source.

The conductive substrate obtained through the above steps was subjected to reflectance and dissolution tests. The results are shown in Table 1.
[Example 2]
The blackening layer was formed in the same manner as in Example 1 except that each gas was supplied so that the volume of nitrogen was 50 vol% and the balance was argon. Note that the gas is supplied into the chamber so that the total gas is 15 sccm.

The results are shown in Table 1.
[Example 3]
When forming the blackening layer, each gas was supplied into the chamber so that nitrogen was 40% by volume, oxygen was 5% by volume, and the balance was argon, and 20% by mass of tungsten oxide was used as the target, and the balance was oxidized. It implemented similarly to Example 1 except the point which used the target which consists of nickel. Note that the gas is supplied into the chamber so that the total gas is 15 sccm.
The results are shown in Table 1.
[Example 4]
When forming the blackened layer, except that the gas was supplied into the chamber so that nitrogen was 40% by volume, oxygen was 2% by volume, and the balance was argon, and the thickness of the blackened layer was 20 nm. The same operation as in Example 3 was performed. Note that the gas is supplied into the chamber so that the total gas is 15 sccm.

The results are shown in Table 1.
[Example 5]
When the blackening layer is formed, the gas is supplied in a volume of 70% by volume of nitrogen, 10% of oxygen, and the balance is argon, and 30% by mass of tungsten oxide is used as a target, and the remainder is made of nickel oxide. This was carried out in the same manner as in Example 1 except that the target to be used was used. Note that the gas is supplied into the chamber so that the total gas is 15 sccm.

The results are shown in Table 1.
[Example 6]
The blackening layer was formed in the same manner as in Example 5 except that each gas was supplied so that the volume of nitrogen was 50 vol% and the balance was argon. Note that the gas is supplied into the chamber so that the total gas is 15 sccm.
The results are shown in Table 1.
[Comparative Example 1]
When the blackening layer is formed, nitrogen is 20% by volume, oxygen is 3% by volume, each gas is supplied so that the balance is argon, and 40% by mass of tungsten oxide is used as the target, and the balance is nickel oxide. It implemented like Example 1 except the point which used the target which consists of. Note that the gas is supplied into the chamber so that the total gas is 15 sccm.

The results are shown in Table 1.
[Comparative Example 2]
When forming the blackening layer, nitrogen contained 50% by volume, oxygen 20% by volume, each gas was supplied so that the balance was argon, and 40% by mass of tungsten oxide as a target, the balance being nickel oxide It implemented like Example 1 except the point which used the target which consists of. Note that the gas is supplied into the chamber so that the total gas is 15 sccm.

  The results are shown in Table 1.

表１に示した結果によると、実施例である実施例１〜実施例６については、波長５５０ｎｍの光の反射率は４０％以下であることが確認できた。また、溶解試験において評価が○または△となっており、銅層及び黒化層が同時に溶解することを確認できた。

According to the results shown in Table 1, it was confirmed that the reflectance of light having a wavelength of 550 nm was 40% or less for Examples 1 to 6 as examples. Moreover, evaluation was (circle) or (triangle | delta) in the dissolution test, and it has confirmed that a copper layer and a blackening layer melt | dissolved simultaneously.

  On the other hand, in Comparative Examples 1 and 2, the reflectance of light having a wavelength of 550 nm is lower than those in Examples 1 to 6, but the blackened layer remained undissolved in the dissolution test. .

This is because the tungsten oxide concentration contained in the target used for forming the blackened layer exceeded 30% by mass, and therefore tungsten oxide was present in the blackened layer in addition to Ni ₃ N. This is thought to be due to the lower reactivity to.

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 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;
And a blackened layer forming step of forming a blackened layer on at least the one surface side of the transparent substrate,
In the blackening layer forming step contains a nickel oxide and tungsten oxide, look-containing tungsten oxide at a ratio of less than 30 wt% to 10 wt%, using a target balance being said nickel oxide A method for producing a conductive substrate, wherein the blackened layer is formed in an atmosphere containing nitrogen. The method for producing a conductive substrate according to claim 1 , wherein the black phase is nickel nitride as a main phase identified from a diffraction pattern obtained by X-ray diffraction. In the blackening layer forming step, the blackening layer is formed by a sputtering method while supplying a gas containing oxygen in a ratio of 0% by volume to 20% by volume and nitrogen in a ratio of 30% by volume to 70% by volume. The manufacturing method of the electroconductive board | substrate of Claim 1 or 2 which forms a film. The copper layer has a thickness of 100 nm or more,
Method for producing a conductive substrate according to any one of claims 1 to 3 wherein the blackening layer is the 20nm or more in thickness. The method for producing a conductive substrate according to any one of claims 1 to 4 , wherein the obtained conductive substrate has a light reflectance of 40% or less at a wavelength of 550 nm. Etching the copper layer and the blackened layer further to form a wiring,
The method for producing a conductive substrate according to any one of claims 1 to 5 , wherein the obtained conductive substrate includes a mesh-like wiring.

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