JP5918614B2 - Conductive substrate, touch panel, and method of manufacturing conductive substrate - Google Patents

Description

  The present invention relates to a conductive substrate, a touch panel, and a method for manufacturing a conductive substrate, and more particularly to a technique for preventing oxidation of a wiring layer in a conductive substrate used for a current collecting electrode of a touch panel or a solar cell.

2. Description of the Related Art Conventionally, touch panels capable of inputting information by directly touching a display screen have been widely used in display units of electronic devices such as mobile phones, car navigation systems, personal computers, ticket vending machines, and bank ATM terminals.
The capacitive touch panel described in Patent Document 1 as an example of such a touch panel has a structure in which two conductive substrates are bonded together, and each conductive substrate is made of a metal oxide on a transparent substrate. The formed transparent conductive layer and the wiring layer made of metal or alloy have a structure in which they are stacked in that order. And the said transparent conductive layer has the electrode part for position detection in the center area | region of a transparent base material, and the said wiring layer was electrically connected with the said electrode part in the peripheral area | region surrounding the said center area | region. It has a wiring part.

JP 2007-18226 A

  In the conductive substrate having the above structure, for example, in order to improve the detection sensitivity of the touch panel, it is conceivable to form the wiring layer with copper having a low electrical resistance. However, since copper is a metal that is relatively easy to oxidize, the wiring layer formed of copper is easily corroded by copper oxidation and easily increases in resistance. Such an increase in resistance of the wiring layer is not preferable because it causes a decrease in detection sensitivity of the touch panel.

  In view of the above problems, an object of the present invention is to provide a conductive substrate, a touch panel, and a solar cell having a wiring layer that has a low electrical resistance and is difficult to increase in resistance. Another object of the present invention is to provide a method for manufacturing such a conductive substrate.

  In order to achieve the above object, a conductive substrate according to the present invention is a conductive substrate having a laminated structure in which a transparent conductive layer and a wiring layer are laminated in that order on a transparent substrate, and the wiring layer is made of copper. And a first coating layer covering a main surface of the wiring body opposite to the transparent base material, the first coating layer comprising a copper and nickel alloy as a main component. The nickel content of the coating layer is 30 wt% to 70 wt%.

  In the method for producing a conductive substrate according to the present invention, a transparent conductive layer and a wiring layer are laminated in this order on a transparent base material, and the wiring layer includes a wiring main body mainly composed of copper, and an alloy containing copper and nickel. And the main body of the wiring main body on the transparent substrate side of the wiring main body, the first coating layer covering the main surface of the wiring main body opposite to the transparent substrate, and an alloy containing copper and nickel. A conductive substrate having a second coating layer covering the surface, wherein the first coating layer and the second coating layer have a nickel content of 30 wt% to 70 wt%, A transparent substrate, a solid film made of a constituent material of the transparent conductive layer (a state where the entire surface is formed), a solid film made of a constituent material of the second coating layer, a solid film made of a constituent material of the wiring body, And a solid film made of the constituent material of the first coating layer. In by stacking a stack forming step of forming a laminate consisting solid film, etching the laminate, characterized in that it comprises a and a patterning step of patterning into a predetermined shape.

  Since the conductive substrate and the touch panel according to the present invention have a wiring body mainly composed of copper, the electrical resistance of the wiring layer is low. In addition, since the main component is an alloy containing copper and nickel, and the first cover layer that covers the main surface of the wiring body opposite to the transparent substrate is provided, the wiring layer is difficult to increase in resistance. If the nickel content of the first coating layer is not 30 wt% or more, it cannot be said that the resistance of the wiring layer is hardly increased, and the nickel content of the first coating layer must be 70 wt% or less. For example, since it is difficult to form the first coating layer by DC magnetron sputtering, it cannot be said that the conductive substrate is practically suitable for production.

  The method for producing a conductive substrate according to the present invention includes a transparent substrate, a solid film made of a constituent material of a transparent conductive layer, a solid film made of a constituent material of a second coating layer, and a solid film made of a constituent material of a wiring body. And a laminated body forming step of laminating a solid film made of the constituent material of the first coating layer in that order to form a laminated body made of the solid films, and etching the laminated body to obtain a predetermined shape Therefore, a wiring layer having low electrical resistance and difficult to increase in resistance can be formed.

1 is a schematic cross-sectional view illustrating a touch panel according to one embodiment of the present invention. 1 is a plan view illustrating a conductive substrate according to one embodiment of the present invention. 1 is a schematic cross-sectional view illustrating a conductive substrate according to one embodiment of the present invention. It is process drawing for demonstrating the manufacturing method of the electroconductive board | substrate which concerns on 1 aspect of this invention. It is a cross-sectional schematic diagram which shows the laminated structure of the electroconductive board | substrate which concerns on an Example. It is a cross-sectional schematic diagram which shows the laminated structure of the electroconductive board | substrate which concerns on a comparative example. It is a graph which shows the measurement result of the spectral reflectance of the surface of a wiring layer. It is a graph which shows the measurement result of the spectral reflectance of the surface of a wiring layer. It is a graph which shows the measurement result of the spectral reflectance of the surface of a wiring layer. It is a graph which shows the measurement result of the spectral reflectance of the surface of a wiring layer. It is a graph which shows the measurement result of the amount of side etching. It is a graph which shows the measurement result of the amount of side etching. It is a table | surface which shows the measurement result of the number of pinholes. It is a table | surface which shows the measurement result of the maximum width of a pinhole. It is a cross-sectional schematic diagram which shows the electroconductive board | substrate which concerns on a modification.

Hereinafter, a conductive substrate, a touch panel, and a method for manufacturing a conductive substrate according to one embodiment of the present invention will be described with reference to the drawings. Note that the scale of each layer in each drawing is different from the actual scale.
<Conductive substrate and touch panel>
(Touch panel)
FIG. 1 is a schematic cross-sectional view illustrating a touch panel according to one embodiment of the present invention. 2A and 2B are plan views illustrating a conductive substrate according to one embodiment of the present invention, in which FIG. 2A illustrates a first conductive substrate and FIG. 2B illustrates a second conductive substrate. Show. 2 is the cutting position of the cross section of FIG.

  A touch panel 1 according to one embodiment of the present invention illustrated in FIG. 1 is a capacitive touch panel, and a first conductive substrate 10 and a second conductive substrate 20 are bonded to each other with an adhesive layer 30 interposed therebetween. It has a structure. The touch panel 1 is used by being disposed on a display surface (not shown) of a display device (not shown) such as a liquid crystal display device, a field emission display device, a plasma display device, an electroluminescent display, or a vacuum fluorescent display device. The touch panel according to the present invention is not limited to the capacitance type, and may be a resistance film type, an optical type, an ultrasonic type, or the like.

  Each of the first conductive substrate 10 and the second conductive substrate 20 is a conductive substrate according to one embodiment of the present invention, and as shown in FIGS. On one main surface side, undercoat layers 12 and 22, transparent conductive layers 13 and 23, and wiring layers 14 and 24 are laminated in that order. The conductive substrates 10 and 20 are arranged so that the laminating directions are opposite to each other, that is, the surfaces on the one main surface side of each other face each other. The conductive substrates 10 and 20 may be arranged so that the stacking direction is the same.

The adhesive layer 30 is made of, for example, an epoxy, acrylic, silicone, polyester, or other transparent adhesive or pressure-sensitive adhesive. The adhesive layer 30 may include a core material such as a transparent film.
For each of the conductive substrates 10 and 20, the undercoat layers 12 and 22 are formed as a so-called solid film that is not patterned or partially patterned. On the other hand, the transparent conductive layers 13 and 23 and the wiring layers 14 and 24 are patterned.

  The transparent conductive layers 13 and 23 include, for example, a plurality of electrode portions 13a and 23a for position detection in the central region of the transparent base materials 11 and 21, and the electrode portion 13a in a peripheral region surrounding the central region. , 23a and connecting portions 13b, 23b electrically connected to the wiring layers 14, 24. Specifically, the electrode portions 13a and 23a are formed in the region with the wavy pattern in FIG. 2, and the connection portions 13b and 23b are formed in the region with the dot pattern in FIG. (In FIG. 2, the connection portions 13b and 23b are not visible behind the wiring layers 14 and 24).

  Each electrode part 13a, 23a is a strip shape in which a plurality of rhombuses are linearly connected, and is arranged so that the longitudinal directions of all the electrode parts 13a, 23a are aligned in parallel for each transparent conductive layer 13, 23. Yes. And the 1st conductive substrate 10 and the 2nd conductive substrate 20 are the longitudinal direction of the electrode part 13a of the 1st transparent conductive layer 13, and the longitudinal direction of the electrode part 23a of the 2nd transparent conductive layer 23 Are stuck together in a state of being orthogonal to each other. In addition, the first conductive substrate 10 and the second conductive substrate 20 are configured such that the electrode portion 13a of the first transparent conductive layer 13 and the electrode portion 23a of the second transparent conductive layer 23 are in a plan view. It is pasted so that the diamonds do not overlap.

  The wiring layers 14 and 24 have, for example, a plurality of line-shaped wiring portions 14a and 24a in the peripheral region of the transparent base materials 11 and 21, and a plurality of wiring portions 14a and 24a that extend to one end of each wiring portion 14a and 24a. Terminal portions 14b and 24b are provided. Specifically, the wiring layers 14 and 24 are formed in a region with a dot pattern in FIG. 2, and the shapes of the wiring layers 14 and 24 are the same as the shapes of the connection portions 13b and 23b. The wiring layers 14 and 24 and the connection portions 13b and 23b overlap in a plan view. The wiring layers 14 and 24 and the connection portions 13b and 23b are in surface contact, and the wiring layers 14 and 24 and the transparent conductive layers 13 and 23 are electrically connected by the surface contact. Furthermore, the wiring layers 14 and 24 are electrically connected to an external circuit (not shown).

The pattern shapes of the transparent conductive layers 13 and 23 and the wiring layers 14 and 24 are not limited to the above, and can be any shape as long as a contact point such as a finger can be detected.
The first conductive substrate 10 and the second conductive substrate 20 have the same configuration except that the pattern shapes of the transparent conductive layers 13 and 23 and the wiring layers 14 and 24 are different. Therefore, in the following, only the first conductive substrate 10 will be described, and the description of the second conductive substrate 20 will be omitted. However, the following description regarding the first conductive substrate 10 also applies to the second conductive substrate 20.

In addition, although the structure using the two transparent base materials 11 and 21 was demonstrated here, electrode part 13a, 23a is formed in both surfaces of the one transparent base material 11, respectively, A configuration in which the electrode portions 13a and 23a are formed on one surface (the overlapping portions of the electrode portions 13a and 23a are insulated) is also possible.
(Transparent substrate)
The transparent substrate 11 is made of PET (polyethylene terephthalate), PEN (polyethylene naphthalate), PES (polyethersulfone), PC (polycarbonate), PE (polyethylene), PP (polypropylene), COP depending on the use of the touch panel. (Cycloolefin polymer), COC (cycloolefin copolymer), PMMA (polymethyl methacrylate), acrylic, siloxane cross-linked acrylic silicone resin, nylon, urethane and other organic materials, soda glass, alkali-free glass, borosilicate glass, quartz It can be formed of an inorganic material such as glass or a hybrid material of these organic material and inorganic material. The material is not particularly limited.

The material of the transparent substrate 11 is preferably an organic material from the viewpoint of light weight and high impact resistance. In view of flexibility and productivity in a roll-to-roll system, a resin film is preferable.
Since the transparent base material 11 is employed, the first conductive substrate 10 is a transparent conductive substrate. In the present application, the term “transparent” includes not only colorless and transparent but also colored and transparent. Moreover, not only perfect transparency but translucency with high transparency is also included.

(Undercoat layer)
The undercoat layer 12 is a layer that has the effect of making the pattern shape of the transparent conductive layer 13 difficult to see and improving the visibility. The undercoat layer 12 is composed of a low refractive index layer (only one layer) made of a material having a lower refractive index than the transparent base material 11 and the transparent conductive layer 13, or a low refractive index layer and a high refractive index layer (from a low refractive index layer). And a layer composed of a material having a high refractive index). The structure of the undercoat layer 12 that improves the visibility is disclosed in JP-T-2007-508639, JP-A-2008-98169, and the like.

Hereinafter, a configuration having a low refractive index layer and a high refractive index layer having a higher optical refractive index than the low refractive index layer will be exemplified.
The undercoat layer 12 is interposed between the transparent base material 11 and the transparent conductive layer 13 in a state where the low refractive index layer is located closer to the transparent conductive layer 13 than the high refractive index layer.
The thickness of the low refractive index layer is preferably 2 nm to 20 nm from the viewpoint of improving visibility. The material of the low refractive index layer includes inorganic oxides such as silicon tin oxide, silicon oxide and aluminum oxide, compositions composed of a combination of two or more of these inorganic oxides, fluorine-based organic materials, silicon oxide-based materials Examples thereof include sol-gel materials, silicon oxide-based and fluorine-based microporous materials. From the viewpoint of improving visibility and productivity, those having an optical refractive index of 1.3 to 1.5 are particularly preferable. The low refractive index layer can be formed by sputtering, resistance vapor deposition, electron beam vapor deposition, wet coating, or the like.

  The high refractive index layer preferably has an optical refractive index of 1.60 to 1.80, more preferably more than 1.65 and not more than 1.80. If the photorefractive index is less than 1.60, it becomes difficult to approximate the optical characteristics of the portion where the transparent conductive layer 13 is present and the portion where the transparent conductive layer 13 is not present, and the pattern shape of the transparent conductive layer 13 becomes conspicuous, and thus good visibility Is difficult to obtain. When the optical refractive index exceeds 1.65, very good visibility can be obtained. Further, when the optical refractive index exceeds 1.80, the optical refractive index difference with the transparent substrate 11 becomes large, and the reflected light at the interface between the transparent substrate 11 and the high refractive index layer, the high refractive index layer and the low refractive index layer are low. As a result of strong occurrence of interference spots due to optical interference with reflected light at the interface with the refractive index layer, the pattern shape of the transparent conductive layer 13 becomes easy to see and visibility is deteriorated, which is not preferable. On the other hand, if the photorefractive index exceeds 1.8, it is difficult to obtain a material or method capable of industrially and efficiently forming a high refractive index layer having hardness and thickness that can improve scratch resistance.

  As a material for forming a high refractive index layer having an optical refractive index of more than 1.65 and not more than 1.80, an acrylic ultraviolet curable resin or a thermosetting resin, an optical refractive index of titanium oxide, zirconium oxide, etc. And high metal oxide fine particles added. In this case, it is necessary that the metal oxide fine particles to be added have a particle size of about several tens of nanometers so as not to disturb the transparency. The thickness of the high refractive index layer is preferably 3 μm or more, and if it is less than 3 μm, light reflected by the interface with the transparent substrate 11 and light reflected by the interface between the high refractive index layer and the low refractive index layer Since interference spots due to interference are strongly generated, the pattern shape of the transparent conductive layer 13 becomes easy to see and visibility is deteriorated.

(Transparent conductive layer)
The transparent conductive layer 13 is a layer for detecting coordinates based on a change in capacitance between the transparent conductive layers 13 and 23, and is made of a metal oxide. Examples of the metal oxide constituting the transparent conductive layer 13 include indium tin oxide (ITO), indium oxide tin monoxide, titanium monoxide (InTiTO), titanium oxide (TiO), indium zinc oxide (IZO), and oxide. Indium (In ₂ O ₃ ), tungsten-doped indium oxide (IWO), titanium-doped indium oxide (ITiO), zinc oxide (ZnO), tin oxide (SnO ₂ ), tin fluoride (SnF ₂ ), aluminum-doped zinc oxide ( AZO), gallium doped zinc oxide (GZO), gallium aluminum doped zinc oxide (GAZO) and the like.

(Wiring layer)
FIG. 3 is a schematic cross-sectional view illustrating a conductive substrate according to one embodiment of the present invention. Specifically, FIG. 3 is a schematic diagram illustrating the cross-section of the first conductive substrate 10 illustrated in FIG. 1 in more detail. is there. As shown in FIG. 3, the wiring layer 14 includes a wiring body 15, a first covering layer 16 that covers the main surface of the wiring body 15 opposite to the transparent substrate 11, and a transparent substrate of the wiring body 15. And a second covering layer 17 covering the main surface on the side. Each wiring portion 14 a of the wiring body 14 includes a wiring body portion 15 a that is a part of the wiring body 15, a first coating layer portion 16 a that is a part of the first coating layer 16, and a second coating layer 17. And a second coating layer portion 17a which is a part of the above.

The wiring body 15 is made of a material mainly composed of copper. Since the wiring layer 14 includes the wiring body 15 mainly composed of copper, the electrical resistance is low. As the material mainly composed of copper, pure copper metal is preferable because of its low electrical resistance.
In addition, in this application, a main component is a component contained most abundantly, and is a component contained normally 70 wt% or more, Preferably it is 80 wt% or more, More preferably, it is 90 wt% or more. The term pure metal is used for differentiation from an alloy, and does not mean 100 wt% copper. Therefore, pure copper metal may contain an element other than copper in an impurity level.

  The material containing copper as a main component may be an alloy of copper and another metal other than copper other than pure copper metal. Other metals include aluminum (Al), nickel (Ni), molybdenum (Mo), silver (Ag), gold (Au), platinum (Pt), palladium (Pd), titanium (Ti), manganese (Mn) Mg (magnesium), Si (silicon), Cr (chromium), Zn (zinc), V (vanadium), Fe (iron), Co (cobalt), Sn (tin), Sb (antimony) and other metals One or more metals selected from

  The first coating layer 16 is formed so as to cover the entire main surface of the wiring body 15 on the side opposite to the transparent base material 11. Accordingly, there is no exposed portion, that is, a portion that comes into contact with air, on the main surface of the wiring body 15 opposite to the transparent substrate 11. Therefore, the wiring body 15 is not easily oxidized, and as a result, the wiring layer 14 is difficult to increase in resistance. The first covering layer 16 does not necessarily strictly cover the entire main surface of the wiring main body 15 opposite to the transparent base material 11, but at least the side of the wiring main body 15 opposite to the transparent base material 11. It is preferable to cover 90% or more of the main surface.

  The second coating layer 17 is formed so as to cover the entire main surface of the wiring body 15 on the transparent base material side. Therefore, the main surface on the transparent base material side of the wiring body 15 does not have an exposed portion, that is, a portion that comes into contact with air. Thus, since the wiring main body 15 is also covered with the 2nd coating layer 17 and the main surface by the side of a transparent base material is also covered, it is hard to oxidize and as a result, the wiring layer 14 is hard to make resistance higher. The second coating layer 17 does not necessarily strictly cover the entire main surface of the wiring body 15 on the transparent substrate side, but at least 90% or more of the main surface of the wiring body 15 on the transparent substrate side is not necessarily covered. It is preferable to cover.

  The first coating layer 16 and the second coating layer 17 are made of a material whose main component is an alloy containing copper and nickel. As an alloy containing copper and nickel, Cu—Ni as an example of an alloy composed of two kinds of metals, Cu—Ni—Ti, Cu—Ni—Fe, Cu—Ni— as examples of an alloy composed of three kinds of metals, Mn, Cu-Ni-Co, Cu-Ni-Nb, Cu-Ni-Mn, Cu-Ni-Cr, etc. are mentioned.

In particular, Cu—Ni is preferable as a constituent material of the first coating layer 16 and the second coating layer 17 because it is difficult to rust (it is difficult to oxidize). Each alloy may contain an element other than the target to the extent of impurities.
Furthermore, the alloy containing copper and nickel preferably has a nickel content of 30 wt% to 70 wt%.

  Unless the nickel content is 30 wt% or more, it cannot be said that the resistance of the wiring layer is hardly increased. That is, since the copper content is relatively increased, the first covering layer 16 is easily corroded by copper oxidation, and the wiring layer 14 is easily increased in resistance. In order to obtain a wiring layer 14 in which the wiring layer is less likely to have a high resistance, the nickel content is preferably 50 wt% or more, and more preferably 60 wt% or more.

  Further, if the nickel content is not less than 70 wt%, it is difficult to form the first coating layer by DC magnetron sputtering, which is not practically suitable for production. That is, since nickel is a magnetic substance, if the nickel content exceeds 70 wt%, it is difficult to form the first coating layer by DC magnetron sputtering, and it is necessary to form the first coating layer by RF magnetron sputtering. This is because the rate cannot be obtained and productivity is poor. In order to make the material more suitable for DC magnetron sputtering, the nickel content is preferably 70 wt% or less.

The first coating layer 16 and the second coating layer 17 are preferably made of the same alloy. In that case, since the number of materials can be reduced, the manufacturing process can be simplified.
Since the second covering layer 17 is formed on the transparent conductive layer 13, it is preferable that the second covering layer 17 is made of a material having high adhesion to the transparent conductive layer 13. In that respect, Cu—Ni—Ti is preferable because it is a material having high adhesion to the metal oxide forming the transparent conductive layer 13.

  As described above, since the wiring layer 14 is covered with the first covering layer 16 on the main surface of the wiring main body 15 opposite to the transparent base material 11, the wiring main body 15 is composed mainly of copper. Despite this, the wiring layer is difficult to increase in resistance due to corrosion. Furthermore, since the wiring layer 14 is also covered with the second coating layer 17 on the main surface of the wiring body 15 on the transparent substrate side, the wiring layer 14 is unlikely to have a high resistance. In addition, since the second covering layer 17 is provided, as will be described later, when the wiring layer 14 is patterned by etching, side etching hardly occurs, and in addition, pin holes are hardly generated in the wiring body 15.

(Method for producing conductive substrate)
A method for manufacturing the conductive substrate 10 will be described. FIG. 4 is a process diagram for describing the method for manufacturing a conductive substrate according to one embodiment of the present invention.
First, as shown to Fig.4 (a), the undercoat layer 12 is formed on the prepared transparent base material 11. FIG. The undercoat layer 12 can be formed by sputtering, resistance vapor deposition, electron beam vapor deposition, or the like.

  Next, the solid film 13A made of the constituent material of the transparent conductive layer 13 and the solid film 14A made of the constituent material of the wiring layer 14 are laminated in that order to form a laminated body 10A made of these solid films (lamination). Body formation step). The solid film 14A made of the constituent material of the wiring layer 14 includes the solid film made of the constituent material of the second coating layer, the solid film made of the constituent material of the wiring body, and the solid film made of the constituent material of the first coating layer. Are laminated bodies formed in that order. Each solid film is formed by sputtering, for example. Note that the method for forming each solid film is not limited to the sputtering method, and may be a PVD method other than the sputtering method such as a vacuum deposition method or an ion plating method, a CVD method, a coating method, or the like.

  Next, the stacked body 10A is etched and patterned into a predetermined shape (patterning step). For patterning, for example, a resist 31 having a predetermined pattern shape is formed on the stacked body 10A as shown in FIG. 4C by photolithography, and then the stacked body as shown in FIG. 4D. This is performed by etching an exposed portion that is not covered with the resist 31 of 10A. Note that the patterning of the solid films 13A and 14A may be performed simultaneously or separately. For the etching of the solid film 13A, an inorganic acid containing at least one of hydrochloric acid and ferric chloride is used. For etching the solid film 14A, an inorganic acid containing at least one or more of ferric chloride, copper chloride, copper sulfate, ammonium peroxodisulfate (ammonium persulfate), nitric acid, phosphoric acid, acetic acid, hydrochloric acid, sulfuric acid, hydrogen peroxide, etc. Is used.

By this etching, the transparent conductive layer 13 is completed. On the other hand, the wiring layer 14 is incomplete because an unnecessary portion still remains in the central region. After the above patterning is completed, the resist 31 is removed from the unfinished wiring layer 14B made of the constituent material of the wiring layer 14, as shown in FIG.
When the constituent material of the second covering layer 17 is Cu—Ni, the constituent material of the wiring body 15 is Cu, and the constituent material of the first covering layer 16 is Cu—Ni, ferric chloride is used. It is preferable to etch the solid film 14A using it as an etchant. If ferric chloride is used, the wiring main body 15 is hardly side-etched. In recent years, in order to increase the size of the touch panel 1 and improve the position detection accuracy, the number of wiring parts 14 a of the wiring layer 14 has increased, and in addition, the peripheral area where the wiring parts 14 a are formed is narrower than the touch panel 1. Since the frame is narrowed to make a frame, there is a situation in which the width of each wiring portion 14a must be narrowed. When the narrow wiring portion 14a is formed, if side etching occurs in the wiring main body portion 15a of the wiring portion 14a, the wiring portion 14a may be electrically disconnected. In order to solve such a problem, it is preferable to etch the solid film 14A using ferric chloride as an etchant as described above, because the wiring body 15 is hardly side-etched. Examples of the etchant include an aqueous ammonium peroxodisulfate solution and an aqueous hydrogen peroxide solution in addition to ferric chloride.

  Next, the wiring layer 14 is completed by etching the incomplete wiring layer 14B. For example, after a resist 32 is formed on the unfinished wiring layer 14B so as to cover the peripheral region by photolithography as shown in FIG. 4F, the resist 32 is formed as shown in FIG. The central region not covered with 32 is etched to complete the wiring layer 14. In this etching, only the unfinished wiring layer 14B is etched, and the transparent conductive layer 13 is not etched. After the etching is completed, the resist 32 on the wiring layer 14 is removed as shown in FIG.

Thus, the conductive substrate 10 is completed.
<Experiment>
Hereinafter, the characteristics of the wiring layer according to the present invention will be described based on experimental results.
[Composition of experimental sample]
FIG. 5 is a schematic cross-sectional view showing the laminated structure of the conductive substrate according to the example. FIG. 6 is a schematic cross-sectional view showing a laminated structure of conductive substrates according to a comparative example. In the experiment, conductive substrates of Examples 1 and 2 as shown in FIG. 5 and conductive substrates of Comparative Examples 1 to 3 as shown in FIG. 6 were prepared as experimental samples.

Each sample has the same configuration for the transparent substrate, the undercoat layer, and the transparent conductive layer. Specifically, the transparent substrate is made of PET. In the undercoat layer, the low refractive index layer is made of silicon oxide, and the high refractive index layer is made of an acrylic resin having zirconia particles. The transparent conductive layer is made of ITO.
The wiring layer has a different configuration depending on each sample. Specifically, the point that the wiring body is made of Cu is common in all the samples, but the first coating layer and the second coating layer are different in configuration. Regarding the first coating layer, Examples 1 and 2 are made of Ni-Cu, Comparative Example 1 is not formed, Comparative Example 2 is made of CuN, and Comparative Example 3 is made of Ni. As for the second coating layer, the second coating layer composed of Ni—Cu is formed only in Example 2, and the second coating layer is formed in Example 1 and Comparative Examples 1 to 3. Not. In addition, Ni-Cu which comprises the 1st coating layer of Example 1, 2 is Ni: Cu = 65: 35 (nickel content is 65 wt%) of the composition ratio of nickel and copper. In each sample, the wiring body has a thickness of 120 nm, the first coating layer has a thickness of 20 nm, and the second coating layer has a thickness of 20 nm.

[Corrosive evaluation method]
The corrosivity of the wiring layer of each sample was evaluated based on the change in reflectance on the surface of the wiring layer (the main surface opposite to the transparent substrate). When the surface layer of the wiring layer (the vicinity of the main surface of the wiring layer on the side opposite to the transparent substrate) is oxidized to produce an oxide film, the refractive index of the surface of the wiring layer changes and the reflectance decreases. This phenomenon is called corrosion of the wiring layer in the present application. If the wiring layer corrodes, that is, if an oxide film is formed on the surface layer of the wiring layer, the resistance of the wiring layer is increased by the oxide film, which is not preferable. When the decrease in reflectance is small, it can be evaluated that an oxide film is hardly formed on the surface layer, that is, the wiring layer is hardly corroded.

The change in reflectance is measured in advance by measuring the spectral reflectance of the surface of the wiring layer of each sample, leaving it for 240 hours under conditions of a temperature of 60 ° C. and a humidity of 90% RH, and then again on the upper surface of the wiring layer of each sample. Spectral reflectance was measured and confirmed by the difference in spectral reflectance before and after the wet heat test.
7 to 10 are graphs showing the measurement results of the spectral reflectance of the surface of the wiring layer. FIG. 7 is the measurement result of Example 1, FIG. 8 is the measurement result of Comparative Example 1, and FIG. 2 is a measurement result. FIG. 10 shows the measurement results of Comparative Example 3. In each figure, “10 nm”, “20 nm”, “30 nm”, and “40 nm” indicate that the thickness of the first coating layer is 10 nm, 20 nm, 30 nm, and 40 nm. “Ini.” Indicates the spectral reflectance before the wet heat test. “Aft.” Indicates the spectral reflectance after the wet heat test.

  As shown in FIG. 7, for Example 1 in which the first coating layer is made of Ni—Cu, the spectral reflectance before the wet heat test is compared with the spectral reflectance after the wet heat test. No significant change was observed in the spectral reflectance regardless of the thickness of the layer. That is, the first coating layer was hardly oxidized. Thus, it was found that when the first coating layer is made of Ni—Cu, the wiring layer is hardly corroded regardless of the thickness of the first coating layer.

  As shown in FIG. 8, when the spectral reflectance before the wet heat test and the spectral reflectance after the wet heat test are compared for Comparative Example 1 that does not have the first coating layer, there is a clear decrease in the spectral reflectance. occured. That is, the first coating layer was clearly oxidized. Thus, when the 1st coating layer was not formed and the wiring main body comprised with Cu was exposed, it turned out that a wiring layer tends to corrode.

  As shown in FIG. 9, for Comparative Example 2 in which the first coating layer is made of CuN, when the spectral reflectance before the wet heat test is compared with the spectral reflectance after the wet heat test, the first coating layer is In any case, a large change was observed in the spectral reflectance. That is, the first coating layer was clearly oxidized. Thus, it was found that even when the first coating layer is made of CuN, the wiring layer is easily corroded regardless of the thickness of the first coating layer.

  As shown in FIG. 10, for Comparative Example 3 in which the first coating layer is made of Ni, when the spectral reflectance before the wet heat test is compared with the spectral reflectance after the wet heat test, the first coating layer is In any case, no significant change was observed in the spectral reflectance. That is, the first coating layer was hardly oxidized. Thus, it was found that when the first coating layer is made of Ni—Cu, the wiring layer is hardly corroded regardless of the thickness of the first coating layer.

  From the above results, it was found that when the first coating layer made of Ni—Cu or Ni was formed, the wiring layer was hardly corroded. By the way, from the viewpoint that the wiring layer is hardly corroded, Ni is also suitable as a constituent material of the first coating layer. However, when the first coating layer is made of Ni, a production problem occurs. Specifically, since Ni is a magnetic material, the first coating layer made of Ni is difficult to form by DC magnetron sputtering and must be formed by RF magnetron sputtering, so that a sufficient film formation rate is obtained. Cannot be obtained, and there is a problem that the productivity of the conductive substrate is poor. Therefore, it is not realistic to employ the first coating layer made of Ni. In addition, since Ni-Cu which comprises the 1st coating layer of Example 1, 2 is non-magnetic whose nickel content is 70 wt% or less and whose Curie temperature is room temperature or less, DC magnetron sputtering is possible. .

[Side etching suppression effect]
Next, the side etching suppression effect of the second coating layer was examined using the samples of Example 1 and Example 2. Specifically, the samples of Examples 1 and 2 were etched with three types of etchants, and the actual line width of the wiring body of the wiring layer was changed to the designed line width (resist line width) by side etching. On the other hand, it was confirmed how narrow it was.

  11 and 12 are graphs showing measurement results of the side etching amount. The X axis shows the line width of the designed wiring body, and the Y axis shows the difference between the designed line width and the actual line width, that is, the side etching amount. The position of “0” on the Y axis is a case where side etching does not occur. When side etching occurs, the Y axis becomes a positive value, and the value of the Y axis increases as the side etching amount increases.

As the etchant, an ammonium peroxodisulfate aqueous solution (20 wt%), an aqueous ferric chloride solution (2.5 wt%), and an aqueous hydrogen peroxide solution (10 wt%) were used.
As a result, first, the results of Example 1 and Example 2 were compared. As shown in FIGS. 11 and 12, any one of ammonium peroxodisulfate aqueous solution, ferric chloride aqueous solution, and ferric chloride was used. Even in the case, Example 2 having the second coating layer had a smaller amount of side etching than Example 1 having no second coating layer. That is, it was found that the side etching of the wiring body can be suppressed by forming the second coating layer. Next, in both Examples 1 and 2, ferric chloride had the smallest amount of side etching and was suitable as an etchant.

(Pinhole prevention effect)
Next, the pinhole prevention effect by the 2nd coating layer was confirmed using the sample of Example 1 and Example 2. FIG.
First, the number of pinholes in the second coating layer was counted to evaluate the ease of occurrence of pinholes. The number of pin poles is measured in the condition of 50 mm □ (area 2.5 × 10 ⁻³ m ² ) in each sample in a state where light is applied from the back side of the sample using a fluorescent lamp. The number of parts that permeate was determined by visual counting.

  FIG. 13 is a table showing the measurement results of the number of pinholes. As shown in FIG. 13, in Example 2 having the second coating layer, the number of pinholes generated in the wiring body was smaller than that in Example 1 having no second coating layer. This is because the layered structure of Example 2 forms a layer composed of Cu on a layer composed of Cu—Ni, and therefore composed of Cu on a layer composed of ITO. It is considered that the fixing of Cu was better at the time of film formation and pinholes were less likely to occur than in Example 1 having a laminated structure in which layers were formed.

Next, the pinhole having the maximum width was extracted from the pinholes generated in the second coating layer, and the maximum width of the pinhole was measured. The maximum width was measured by observing a pinhole with a laser microscope at a magnification of 1000 times.
FIG. 14 is a table showing the measurement results of the maximum pinhole width. As shown in FIG. 14, in Example 2 having the second coating layer, the maximum pinhole width was smaller than that in Example 1 having no second coating layer, that is, a large pinhole was generated. It was difficult. The reason why large pinholes were difficult to occur is considered to be the same reason as that in Example 2 where the number of pinholes was small.

<Modification>
As described above, the conductive substrate, the touch panel, and the method for manufacturing the conductive substrate according to one embodiment of the present invention have been specifically described, and these are the manufacture of the conductive substrate, the touch panel, and the conductive substrate according to the present invention. It is an example for demonstrating the structure of a method and an effect easily, Comprising: The manufacturing method of the electroconductive board | substrate, touchscreen, and electroconductive board | substrate which concerns on this invention is not limited to those content. For example, the above materials, numerical values, and the like are merely preferable examples and are not limited thereto. In addition, modifications as described below are also conceivable.

  FIG. 15 is a schematic cross-sectional view showing a conductive substrate according to a modification. In the conductive substrate 40 according to the modification shown in FIG. 15, an undercoat layer 42, a transparent conductive layer 43, and a wiring layer 44 are laminated in this order on a transparent base material 41. The wiring layer 44 is entirely formed of a solid film. The wiring layer 44 has a structure in which a wiring body 45, a first coating layer 46, and a second coating layer 47 are laminated in this order, and the wiring body 45, the first coating layer 46, and the second coating layer are stacked. 47 is also a solid film. Thus, the transparent conductive layer and the wiring layer according to the present invention are not necessarily patterned, and the patterning for each layer is arbitrary. The conductive substrate 40 in which the transparent conductive layer 43 and the wiring layer 44 are not patterned is distributed as, for example, a semi-finished product, and a necessary layer is patterned according to the intended use.

The electroconductive board | substrate which concerns on this invention should just be equipped with the 3 layers of a transparent base material, a transparent conductive layer, and a wiring layer at least. Whether or not it has an undercoat layer is arbitrary. Another layer may be included instead of the undercoat layer, or another layer may be included in addition to the undercoat layer. Another layer may be a single layer or a plurality of layers.
The wiring layer which concerns on this invention should just be equipped with the wiring main body and the 1st coating layer at least. It is arbitrary whether or not the second covering layer is provided. Another layer may be included instead of the second coating layer, or another layer may be included in addition to the second coating layer. Another layer may be a single layer or a plurality of layers. Moreover, another layer may be arrange | positioned at the transparent base material side with respect to the wiring main body, and may be arrange | positioned at the opposite side to a transparent base material.

  The conductive substrate according to the present invention includes a sensor such as a touch panel of an electronic device such as a mobile phone, a car navigation system, a personal computer, a ticket machine, and an ATM terminal of a bank, a display device such as an organic EL display and electronic paper, and a light control mirror. It can be widely used for surrounding wiring such as glass and current collecting wiring for solar cells.

DESCRIPTION OF SYMBOLS 1 Touch panel 10,20,40 Conductive board | substrate 11,21,41 Transparent base material 12,22,42 Undercoat layer 13,23,43 Transparent conductive layer 14,24,44 Wiring layer 15,25,45 Wiring main body 16, 26, 46 1st coating layer 17, 27, 47 2nd coating layer

Claims (9)

A conductive substrate having a laminated structure in which a transparent conductive layer and a wiring layer are laminated in that order on a transparent substrate,
The wiring layer includes a wiring main body mainly composed of copper, and a first coating layer that is composed mainly of an alloy containing copper and nickel and covers a main surface of the wiring main body opposite to the transparent base material. Have
The conductive substrate, wherein the nickel content of the first coating layer is 60 wt% to 70 wt%. The transparent conductive layer has an electrode part in the central region of the transparent substrate and is patterned to have a connection part extending from the electrode part in a peripheral region surrounding the central region,
The conductive substrate according to claim 1, wherein the wiring layer is patterned to have a wiring portion in contact with the connection portion in the peripheral region.   The conductive substrate according to claim 1, wherein the first covering layer is made of an alloy of copper and nickel. The wiring layer has a second coating layer that mainly contains an alloy containing copper and nickel and covers a main surface of the wiring body on the transparent base material side;
4. The conductive substrate according to claim 1, wherein the nickel content of the second coating layer is 60 wt% to 70 wt%.   The conductive substrate according to claim 4, wherein the second coating layer is made of an alloy of copper and nickel. The conductive substrate according to claim 4, wherein the first coating layer and the second coating layer are made of an alloy of copper, nickel, and titanium. Touch panel characterized by comprising a conductive substrate according to any one of claims 1 to 6. A transparent conductive layer and a wiring layer are laminated in that order on a transparent substrate, and the wiring layer is composed of a wiring main body mainly composed of copper and an alloy containing copper and nickel as main components, and the transparent base material of the wiring main body. A first coating layer covering the main surface opposite to the main surface, and a second coating layer mainly composed of an alloy containing copper and nickel and covering the main surface of the wiring body on the transparent substrate side. A method for producing a conductive substrate, wherein the nickel content of the first coating layer and the second coating layer is 60 wt% to 70 wt%,
A solid film made of a constituent material of the transparent conductive layer, a solid film made of a constituent material of the second coating layer, a solid film made of a constituent material of the wiring body, and the first coating A laminated body forming step of laminating solid films made of the constituent materials of the layers in that order to form a laminated body made of the solid films;
A patterning step of etching the laminate and patterning the laminate into a predetermined shape;
The manufacturing method of the electroconductive board | substrate characterized by the above-mentioned. A step of further laminating an undercoat layer between the transparent base material and the transparent conductive layer, wherein the undercoat layer is made of a material having a lower refractive index than the transparent base material or the transparent conductive layer. The method for manufacturing a conductive substrate according to claim 8 , wherein the conductive layer is formed of a refractive index layer or two or more layers obtained by combining the low refractive index layer and the high refractive index layer.

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