JPWO2013176155A1 - Patterned conductive substrate manufacturing method, patterned conductive substrate and touch panel thereby - Google Patents

Abstract

A step of forming a resist layer on a part of the outermost layer of the conductive substrate in which at least the substrate, the inorganic oxide layer and the conductive layer are formed in this order; and contacting the conductive substrate with an aqueous solution containing fluoride ions, A method for producing a patterned conductive substrate, comprising a step of patterning the conductive layer by removing the conductive layer together with the inorganic oxide layer in a portion where a resist is not formed. Provided is a novel method for patterning a conductive film, which is excellent in handleability and applicable to existing equipment.

Description

  In the present invention, at least a base material, an inorganic oxide layer and a conductive layer are formed in this order, and a resist is formed by bringing a conductive base material having a resist layer as a part of the outermost layer into contact with an aqueous solution containing fluoride ions. The present invention relates to a method for producing a patterned conductive substrate in which the conductive layer is removed together with the inorganic oxide layer in a portion that is not present, a conductive substrate patterned by this production method, and a touch panel using the patterned conductive substrate It is.

  Transparent conductive films are widely used in electronic display devices such as flat panel displays and touch panels. The transparent conductive material is typified by tin-doped indium oxide (hereinafter referred to as ITO), and the demand and usage of ITO continue to increase. However, since indium is a rare metal, it replaces indium, or it is a novel that compensates for the disadvantages inherent in ITO transparent conductive films, such as weakness to bending and difficult to reduce costs due to vacuum film formation. As conductive materials, carbon nanotubes (hereinafter referred to as CNT), conductive polymers, metal nanoparticles, metal nanowires, and the like have been actively developed. These new materials are of a type that can be applied under atmospheric pressure, and a method of applying a dispersion in which ITO is also made into fine particles has been developed. Therefore, there are high expectations for the development of new conductive materials.

As a novel conductive material, for example, it has been proposed to apply CNT or silver nanowire as a transparent conductive laminate to a touch panel (for example, see Patent Document 1). Moreover, applying a conductive polymer to electronic paper as a transparent conductive layer is proposed (for example, refer patent document 2). It has also been proposed to use ITO powder together with a binder resin (see, for example, Patent Document 3).

  In general, many conductive films are used by forming a pattern like a line electrode. On the other hand, there are products that are used on the entire surface of the substrate, that is, without patterning, but the types of the products are limited. Therefore, the patterning method of the conductive film is important. The conductive film is required to have a uniform surface resistance. Further, in the case of a transparent conductive film, the light transmittance is also required to be uniform. For this reason, it is indispensable that the patterned conductive base material is formed by uniformly forming a conductive material on the entire surface of the base material and then removing unnecessary portions to form a pattern.

  A method of patterning a CNT film applicable as a conductive film by dry etching has been proposed (see, for example, Patent Document 4). An etchant that improves the etching properties of an existing ITO conductive film has been proposed (see, for example, Patent Document 5).

Further, as one method for forming an elongated CNT electrode, a method of forming a pattern by etching a CNT film using a resist has been proposed (for example, see Patent Document 6).
JP 2011-167848 A JP 2011-69993 A Japanese Patent Laying-Open No. 2005-078986 JP 2002-234000 A JP 2008-270458 A US Pat. No. 7,285,198

  In addition to ITO and metal thin films, materials used for conductive films are diversifying, such as CNT, silver nanowires, and conductive polymers. In order to pattern them using a wet process, search for etchants each time. There was a need to develop or develop. Also, existing etchants for ITO and metal thin films are often strong acids, mixed acids, oxidizing or corrosive chemicals, and strong alkalis, and careful handling and handling equipment design was required. .

  The conductive film described in Patent Documents 1 to 3 can be patterned using the dry etching process described in Patent Document 4 depending on the layer configuration. However, the general ITO wet etching process described in Patent Document 5 cannot be applied, and the difference in the etching process becomes a barrier to cost competitiveness when developing a new conductive film.

  In addition, iron chloride used in the etchant of Patent Document 5 is a general chemical, but it is highly corrosive and can be used as an anti-corrosion measure for etching equipment, ancillary equipment such as rooms where the equipment is installed, and exhaust ducts. This included factors that would increase the cost of the equipment, such as being necessary. Even in Patent Document 6, hydrofluoric acid, which is dangerous to handle, was used.

  In view of the above-described problems of the prior art, an object of the present invention is to provide a novel method for patterning a conductive film, which is excellent in handleability and to which existing equipment can be applied.

In order to solve the above-described problems, a method for producing a patterned conductive substrate of the present invention has the following configuration. That is,
A step of forming a resist layer on a part of the outermost layer of the conductive substrate in which at least the substrate, the inorganic oxide layer and the conductive layer are formed in this order; and contacting the conductive substrate with an aqueous solution containing fluoride ions, It is a manufacturing method of the patterned conductive base material including the process of patterning the said conductive layer by removing the said conductive layer with the said inorganic oxide layer in the part in which the resist is not formed.
The patterned conductive substrate of the present invention has the following configuration. That is,
The conductive layer contains carbon nanotubes, and the conductive layer removed portion is a conductive base material patterned by the above manufacturing method in which the base material surface is exposed.
The touch panel of the present invention has the following configuration. That is,
A touch panel using the patterned conductive substrate.
In the method for producing a patterned conductive substrate of the present invention, the aqueous solution containing fluoride ions is preferably an aqueous solution of at least one of alkali metal fluorides and fluoride ammonium salts.
In the method for producing a patterned conductive substrate of the present invention, the pH of the aqueous solution containing fluoride ions is preferably 1-7.
In the method for producing a patterned conductive substrate of the present invention, the inorganic oxide layer is preferably a layer containing silica and / or alumina.
In the method for producing a patterned conductive substrate according to the present invention, the conductive layer preferably contains carbon nanotubes.

  The patterning method of the present invention is excellent in handleability and corrosion resistance, and the conductive film can be patterned with high resolution using existing equipment.

It is the schematic which shows the layer structure of the electrically conductive base material in this invention. It is the schematic which shows the example of the conductive layer pattern formation method in this invention.

  In the present invention, at least a base material, an inorganic oxide layer and a conductive layer are formed in this order, and a resist is formed by bringing a conductive base material having a resist layer as a part of the outermost layer into contact with an aqueous solution containing fluoride ions. This is a method for producing a patterned conductive substrate in which the conductive layer is removed together with the inorganic oxide layer in a portion that is not. In particular, by providing an inorganic oxide layer, various required characteristics such as the performance as a conductive substrate, lamination processability, patternability, conductive characteristics after patterning, stability of optical characteristics and physical durability characteristics, etc. are balanced. Can be achieved. Furthermore, with respect to patterning property, patterning process stability can be obtained by specifically etching and patterning when the conductive substrate is in contact with an aqueous solution containing fluoride ions.

  The substrate in the present invention includes polyethylene terephthalate (hereinafter referred to as PET), polyethylene naphthalate (hereinafter referred to as PEN), polycarbonate (hereinafter referred to as PC), polymethyl methacrylate (hereinafter referred to as PMMA), polyimide, polyphenylene sulfide (hereinafter referred to as PPS), Aramid, polypropylene (hereinafter referred to as PP), polyethylene (hereinafter referred to as PE), polylactic acid (hereinafter referred to as PLA), polyvinyl chloride (hereinafter referred to as PVC), alicyclic acrylic resin, cycloolefin, triacetylcellulose, and other polymers A substrate made of a material can be used. These substrates may be a film having a thickness of 200 μm or less, or a thick film substrate having a thickness greater than that. Moreover, a metal substrate, metal foil, a glass substrate, a flexible thin film sheet-like glass base material etc. can be used as a base material. In order to facilitate the formation of an oxide layer on these substrate surfaces or to ensure adhesion after formation, glow discharge treatment, corona discharge treatment, plasma treatment, UV ozone treatment, flame treatment, acid cleaning treatment Further, surface treatment such as alkali cleaning treatment, and in addition to these, self-assembled monomolecular (SAM) layer treatment may be performed, and a resin layer may be provided separately.

  As the inorganic oxide constituting the inorganic oxide layer in the present invention, silica, alumina, titania, zirconia and the like are used, and polysiloxane is also used. Alternatively, a glass material mainly composed of silicon dioxide is also used, and boron oxide, phosphorus oxide, sodium oxide, magnesium oxide, calcium oxide and the like may be included as subcomponents. For the formation of the inorganic oxide layer, a dry process such as sputtering or chemical vapor deposition (hereinafter referred to as CVD) can also be applied. However, a coating solution containing an inorganic oxide or a precursor thereof and a solvent is applied to the substrate. A wet process is preferably used in which an inorganic oxide layer is formed by coating on top and drying and heating. There is a sol-gel method as a method of forming by a wet process. An inorganic oxide layer can be obtained by applying a sol dispersion obtained by hydrolyzing a metal alkoxide or the like, followed by dehydration condensation after forming a coating film. In addition, a metal alkoxide or a metal chelate compound may be mixed in the sol dispersion described above or used alone. Tetraalkoxy such as tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetra-i-propoxysilane, and tetra-n-butoxysilane are used as raw materials for forming the silica-based inorganic oxide layer. Silanes, methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, i-propyltrimethoxysilane, i-propyltriethoxysilane N-butyltrimethoxysilane, n-butyltriethoxysilane, n-pentyltrimethoxysilane, n-pentyltriethoxysilane, n-hexyltrimethoxysilane, n-heptyltrimethoxysilane, n-octyltrimethoxysilane , Vinyltrimethoxysilane, vinyltriethoxysilane, cyclohexyltrimethoxysilane, cyclohexyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, 3-chloropropyltrimethoxysilane, 3-chloropropyltriethoxysilane, 3,3 , 3-trifluoropropyltrimethoxysilane, 3,3,3-trifluoropropyltriethoxysilane, 2-hydroxyethyltrimethoxysilane, 2-hydroxyethyltriethoxysilane, 2-hydroxypropyltrimethoxysilane, 2-hydroxy Propyltriethoxysilane, 3-hydroxypropyltrimethoxysilane, 3-hydroxypropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxyp Pyrtriethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltriethoxysilane, 3- (meth) acryloxypropyltrimethoxysilane, 3- ( Organalkoxys such as trialkoxysilanes such as (meth) acryloxypropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, allyltrimethoxysilane, vinyltriacetoxysilane, methyltriacetyloxysilane, methyltriphenoxysilane Silane is used. These raw materials are used by being dissolved or dispersed in alcohol, water, or an organic solvent, and are used by appropriately mixing an acid catalyst or a base catalyst. Furthermore, the above-mentioned silane-based material is polymerized in advance in a molecular weight range that is soluble in a solvent, and the resulting polysiloxane is mixed with a solvent and an acid, applied and dried, and then subjected to a hydrolysis and polymerization reaction by heating. May be formed.

  Further, the inorganic oxide layer preferably contains silica fine particles, alumina fine particles, titania fine particles, zirconia fine particles, polymer fine particles and the like. The particle diameter of these fine particles is preferably in the range of several nm to several μm.

  The composition that is the main component of the inorganic oxide layer, the presence or absence of fine particles, and the type and content of fine particles when they are included are determined by the optical properties, conductive properties, physical properties, and process during layer coating. It can be selected in consideration of sex. For example, when the conductive layer is formed on the conductive layer, when the solvent of the coating solution is aqueous, the inorganic oxide layer contains hydrophilic fine particles to improve the wettability of the conductive coating solution. Further, it is possible to make the film thickness uniform, and in turn, make the conductivity uniform. Thus, the fine particles are useful for controlling the properties of the inorganic oxide layer.

  In addition, since the inorganic oxide layer contains fine particles, irregularities are formed on the surface of the inorganic oxide layer, and an insulating component such as a dispersant contained in the conductive layer coating liquid is selectively adsorbed. It is also possible. By carrying out like this, since an electroconductive component can be collected on a surface layer and the contact resistance of electroconductive parts can be reduced, an electroconductive characteristic can be improved. At this time, the conductive layer film obtained has a smaller amount of dispersant component than the composition in the coating solution, so that the re-solubility of the conductive layer in the dispersion medium can be reduced and laminated on the conductive layer by wet coating. In doing so, it is possible to prevent the elution of the components of the conductive layer.

  Physical durability can also be controlled by changing the type of inorganic oxide and the type or content of particles. If the content of fine particles is increased, the sol-gel hydrolysis conditions are moderated, or the polysiloxane curing conditions are moderated to reduce the crosslink density of the inorganic oxide layer, a flexible material should be used for the substrate. When used, the bending durability can be improved. On the other hand, the hardness of the surface can be improved by reducing the amount of fine particles added and increasing the curing conditions.

  The thickness of the inorganic oxide layer is preferably 1 nm to 10 μm, and more preferably 10 nm to 500 nm. By being in this range, optical characteristics, physical strength characteristics, patterning properties, and the like can be improved in a balanced manner.

  When the inorganic oxide layer is formed by a coating process, any of dip coater, bar coater, gravure coater, die coater, spin coater, screen printing, ink jet coating and the like can be preferably used. Alternatively, the inorganic oxide layer can be formed by a dry process such as a sputtering method or a CVD method.

For the conductive layer used in the present invention, a material having a volume resistivity of 10 ⁻⁶ to 10 ⁸ Ωcm can be used. Generally, metals are classified as 10 ⁻⁶ to 10 ⁻³ Ωcm, and semiconductors are classified as 10 ⁻³ to 10 ⁸ Ωcm, and any of them can be used. When conductive fine particles or conductive fibrous materials are used for the conductive layer, they are mixed with a dispersant for dispersing them or used with a binder resin for forming a coating film. Sometimes. In that case, the mixture is referred to as a conductive layer. Specific examples of the conductive layer used in the present invention include CNT, graphene, fullerene, fullerene whisker, carbon fine particle, metal fine particle, metal nanowire, conductive polymer, metal thin film, metal oxide thin film, metal oxide fine particle, metal There are oxide nanowires. Among them, those capable of forming a conductive layer by coating are more preferable, and conductive formed using a CNT dispersion, graphene dispersion, metal colloid dispersion, metal nanowire dispersion, conductive polymer, metal oxide fine particle dispersion, or the like. A layer is preferred. In particular, CNT is preferred when used for transparent conductive applications. CNTs are particularly preferable in that they have low surface reflection, excellent flexibility, high stability against environmental changes, and high reliability even when a micropattern is formed by forming a fine network of microfibers. There are single-walled CNTs, double-walled CNTs, thin-walled CNTs of 3-5 layers, multi-walled CNTs, etc., but it is preferable to use these because double-walled CNTs can achieve both higher transmittance and higher conductivity. .

  The conductive layer of the present invention is preferably a thin film. Here, the thin film refers to a film having a thickness of 10 μm or less, and usually has a thickness of 100 nm or less. The thickness can be determined according to the required sheet resistance, light transmittance, and the like. For example, when CNT is used as the transparent conductive layer, the thickness is preferably 5 to 50 nm.

  A protective layer can be provided on the outermost layer of the conductive substrate in the present invention. The material used for the protective layer may be an inorganic oxide used for the base layer of the conductive layer, or a normal polymer, and needs the friction resistance, flex resistance, light resistance, hardness, etc. required for the substrate. It can be appropriately selected according to the characteristics. The thickness of the protective layer is preferably about 10 nm to 5 μm, but is not limited thereto. When the contact resistance on the surface of the conductive layer is reduced as in a resistive film type touch panel, the protective layer thickness is preferably 10 to 100 nm, and when used for a capacitive touch panel or electromagnetic shield, it is formed thicker than this. be able to.

  FIG. 1 shows an example of a conductive substrate in the present invention. An inorganic oxide layer 102, a conductive layer 103, and a protective layer 104 are provided over the substrate 101.

  Next, the manufacturing method of the patterned electrically conductive base material of this invention is demonstrated.

  The conductive base material in which the base material, the inorganic oxide layer, and the conductive layer are formed in this order can be removed together with the inorganic oxide layer by contacting the strong acid aqueous solution or the strong alkaline aqueous solution. At this time, by providing a patterned resist layer on the outermost layer, it is possible in principle to selectively remove and pattern the conductive layer and inorganic oxide layer in the portion where the resist layer does not exist. It is. However, it is difficult to remove the conductive layer and the inorganic oxide layer according to the pattern of the resist actually provided on the outermost layer. For example, when immersed in a strong alkaline aqueous solution, the conductive layer tends to be completely removed including the portion where the resist is provided. Since the inorganic oxide is easily attacked by the strong alkaline aqueous solution and the entire inorganic oxide layer is easily peeled off from the substrate, it is difficult to selectively remove it according to the resist pattern. Further, when immersed in an aqueous solution of strong acid, the conductive layer can be removed according to an approximate resist pattern, but poor removal and excessive removal are mixed, resulting in poor pattern precision. The inorganic oxide layer is peeled off from the substrate by permeation of a strong acid, but the inorganic oxide layer itself is not decomposed and is therefore selectively removed by tearing along the resist pattern shape. Therefore, it becomes difficult to precisely control the pattern shape.

  Therefore, as a result of intensive studies, the inventors have found that the conductive layer can be removed according to the resist pattern provided on the outermost layer by bringing the conductive substrate as described above into contact with an aqueous solution containing fluoride ions. I found it. The method for producing a patterned conductive substrate according to the present invention utilizes this wet etching method. That is, the method for producing a patterned conductive substrate of the present invention includes a step of forming a resist layer on a part of the outermost layer of the conductive substrate in which at least the substrate, the inorganic oxide layer, and the conductive layer are formed in this order; It is a method of patterning the conductive layer by bringing the conductive base material into contact with an aqueous solution containing fluoride ions and removing the conductive thin film layer where the resist is not formed together with the inorganic oxide layer. In this method, the aqueous solution containing fluoride ions penetrates from the outermost layer into the inorganic oxide layer that is the base of the conductive layer, and the inorganic oxide layer is peeled off from the base material, so that the conductive layer is separated from the inorganic oxide layer. By being removed, patterning is performed. It is known that an aqueous solution containing fluoride ions is used for surface etching of a silicon substrate or quartz glass. The present inventors have found that an aqueous solution containing fluoride ions permeates the conductive layer and penetrates to the inorganic oxide layer which is the base layer, and have reached the present invention. Furthermore, the method of the present invention also has an effect that a desired pattern can be obtained without side etching due to penetration into the lower portion of the remaining resist portion.

  FIG. 2 is a process diagram showing an example of a conductive layer pattern forming method in the present invention. In the conductive substrate, an inorganic oxide layer 102, a conductive layer 103, and a protective layer 104 are provided on a substrate 101, and a resist 105 is provided on the outermost layer. After patterning the resist 105, the conductive substrate is brought into contact with an aqueous solution containing fluoride ions. Accordingly, the protective layer 104, the conductive layer 103, and the inorganic oxide layer 102 are all peeled from the base material 101. Finally, if the resist 105 is removed, a patterned conductive substrate is obtained.

Although there is no restriction | limiting in particular as aqueous solution containing a fluoride ion, The aqueous solution of the compound illustrated below can be mentioned. Alkali metal fluorides such as lithium fluoride (LiF), sodium fluoride (NaF), potassium fluoride (KF), AlF ₃ , BiF ₃ , CaF ₂ , CrF ₂ , MgF ₂ , PtF ₂ , RhF ₂ , ThF ₄ , fluorides of metals other than alkali metals such as UF ₄ , sodium hydrogen fluoride (NaHF ₂ ), potassium hydrogen fluoride (KHF ₂ ), ammonium fluoride (NH ₄ F), ammonium hydrogen fluoride (NH ₄ HF ₂ ), N, N, N-trimethylmethane fluoride ((CH ₃ ) ₄ NF), benzyltrimethylammonium fluoride (C ₆ H ₅ CH ₂ (CH ₃ ) ₃ NF), tetraethylammonium fluoride ((C ₂ H _{5) 4} NF), tetrapropylammonium fluoride, tetrabutylammonium fluorous , Methyltriethylammonium fluoride, methyltributylammonium fluoride, dimethyldiethylammonium fluoride, dodecyltrimethylammonium fluoride, tetradecyltrimethylammonium fluoride, hexadecyltrimethylammonium fluoride, octadecyltrimethylammonium fluoride, benzyltriethylammonium fluoride Such as fluoride, ammonium salt of fluoride such as benzyltripropylammonium fluoride, benzyltributylammonium fluoride, phenyltrimethylammonium fluoride, phenyltriethylammonium fluoride, phenyltripropylammonium fluoride, phenyltributylammonium fluoride, etc. . Buffered hydrofluoric acid can also be used. In addition, hardly soluble fluorides such as AlF ₃ , BiF ₃ , CaF ₂ , CrF ₂ , MgF ₂ , PtF ₂ , RhF ₂ , ThF ₄ , UF _4, etc. can be dissolved and used at high temperatures together with strong acids. . These hydrates or a mixture of two or more of these may be used. Among these, an ammonium salt of fluoride or an alkali metal fluoride is preferable. Specifically, ammonium fluoride, sodium fluoride, or potassium fluoride is preferably used. Two or more of these may be mixed, but it is more preferable to use one alone. Although the production method of the present invention can be carried out using hydrofluoric acid, it is used only in a strictly controlled environment only when the concentration of hydrogen fluoride in water is 1% by mass or less. be able to. Using an aqueous solution with a hydrogen fluoride concentration of several percent by mass or more increases the possibility of workers being exposed to hydrogen fluoride gas and reacts with calcium in the body to cause hypocalcemia. Rise. For this reason, when hydrofluoric acid is used, it is necessary to carry out it within a dedicated draft or chamber, and careful handling is required for handling.

  The aqueous solution containing fluoride ions is preferably controlled in pH by mixing other acid or base. Thereby, process stability at the time of removing a conductive film can be improved. Known acids and bases can be used. Examples of acids include sulfuric acid, hydrochloric acid, nitric acid, oxalic acid, acetic acid, phosphoric acid, benzenesulfonic acid, and toluenesulfonic acid. Examples of bases include sodium hydroxide and potassium hydroxide. Sodium carbonate, sodium hydrogen carbonate, tetramethylammonium hydroxide, 2-aminoethanol and the like are used. Of course, the acid and base used are not limited to these. The pH of the aqueous solution containing fluoride ions is preferably in the range of 1-7, more preferably in the range of pH1-6. By setting the pH in the range of 1 to 7, the conductive layer can be stably removed in a desired pattern with good reproducibility, and the concentration of fluoride ions required for removing the conductive layer can be reduced. In addition, the processing time can be shortened.

  The aqueous solution containing fluoride ions may further contain an organic solvent having affinity for water, a surfactant, and the like. An organic solvent and a surfactant can be appropriately selected according to each purpose such as control of wettability to a conductive substrate, control of permeability to a conductive film, and suppression of bubbles in an etching tank.

The concentration of fluoride ions in the aqueous solution containing fluoride ions is determined according to the type of the conductive layer of the conductive substrate, the thickness of each layer, and the tact time of the patterning equipment, and is 1 × 10 ⁻⁵ to 10 mol / L. A range is preferable. In consideration of solubility of fluoride ions in water and patterning properties of the conductive layer, 0.0001 to 0.1 mol / L is more preferable.

  The concentration of acid or alkali contained in the aqueous solution containing fluoride ions is preferably 1/1000 to 1,000 times, more preferably 1/10 to 10 times the molar concentration of fluoride ions. is there. In terms of molar concentration, it is preferably 0.0001 to 0.1 mol / L. More preferably, patterning can be performed more stably using an acid than an alkali.

  When the conductive substrate is removed by bringing the conductive substrate into contact with an aqueous solution containing fluoride ions, the temperature of the aqueous solution is preferably 25 to 80 ° C. Although it is possible to use it outside this range, it is more preferably 30 to 60 ° C. in order to control with a heater higher than room temperature and suppress moisture volatilization.

  In the step of removing the conductive layer from the conductive substrate, a method of immersing the conductive substrate in the aqueous solution, a method of showering the aqueous solution on the conductive substrate, a method of passing the conductive substrate through the water flow by the aqueous solution, etc. Either method can be used. After contacting the conductive substrate with the aqueous solution, it is preferable to drain the water once and then wash with water. For this washing step, any method such as dipping, showering or passing through a water stream can be used.

  As a resist provided in a part of the outermost layer of the conductive base material, a screen printing resist or a photoresist can be used. As the photoresist, a dry film resist that is used by transferring a photoresist already formed into a sheet shape onto a substrate, or a coating type photoresist that is used by applying a resist solution with a spin coater or the like can be used. . These resists can be used properly according to the required definition. It is preferable to use a screen printing resist if the accuracy is 100 μm or more, a dry film resist if the accuracy is 20 μm or more, and a coating type photoresist if the accuracy is 20 μm or less. When a photoresist is used, a development process using an alkaline aqueous solution is performed after exposure. At this time, fluoride ions are dissolved in the alkaline aqueous solution, and the conductive layer is removed along with the development and removal of the photoresist. It is also possible to do. However, from the viewpoint of process control, it is more preferable that the development of the photoresist is performed with a normal alkaline aqueous solution, and the conductive layer is removed with an aqueous solution containing fluoride ions.

The conductive layer removed portion of the conductive base material patterned by the above-described method is preferably exposed at the base material surface. Here, “the substrate surface is exposed” means that the inorganic oxide layer is almost completely removed and the substrate surface is not damaged. By using the wet etching method described above, the substrate surface can be easily and cleanly exposed. On the other hand, for example, when laser etching is performed, if the conditions are excessive, the surface of the base material is swollen, and conversely, if the conditions are weak, the conductive layer or the oxide layer remains and the base material surface is exposed cleanly. It is difficult to let In addition, problems such as an increase in haze value due to surface roughness also occur. In laser etching, care should be taken because the ablated conductive layer waste or oxide layer waste is likely to be scattered on the surface of the conductive base material to cause foreign matter defects. Furthermore, when the waste of the conductive layer is scattered in the conductive layer removal portion, conductivity is generated in an unintended portion, and for example, when used as a conductive base material such as a touch panel described later, it causes a malfunction.
However, these problems can be solved by using the above-described wet etching method. The surface of the exposed substrate after removing the conductive layer can be confirmed using an optical microscope, a laser microscope, an atomic force microscope, etc., and the transmittance and reflectance are measured with a spectrophotometer. The haze meter can be confirmed using elemental composition using X-ray photoelectron spectroscopy (XPS), and functional group information using microscopic infrared spectroscopy.

Two examples of patterning procedures A and B using the wet etching method described above are shown below. However, the method of the present invention is not limited to these.
[Patterning procedure A]
(A-1) A coating type photoresist is spin-coated on the outermost layer of the conductive substrate and dried.
(A-2) Ultraviolet rays are irradiated to a portion where the conductive layer is to be removed through a photomask to solubilize the photoresist with alkali.
(A-3) A resist pattern is formed by alkali development and washing with water.
(A-4) After the water washing, drying and heat treatment are performed in an oven or hot plate at about 50 to 120 ° C.
(A-5) Immerse in an aqueous solution containing fluoride ions.
(A-6) Unnecessary portions of the conductive layer are removed by shower water washing.
(A-7) The photoresist on the conductive layer is removed by dipping in an organic solvent or a strong alkaline aqueous solution.
(A-8) Washing with water, air blowing, and drying at 50 to 120 ° C.
[Patterning procedure B]
(B-1) A dry film resist is laminated on the conductive substrate using a laminator equipped with a hot roller on the outermost layer of the conductive substrate.
(B-2) An ultraviolet ray is irradiated to the part which wants to obtain a conductive layer through a photomask, and a photoresist is photocured.
(B-3) A resist pattern is formed by alkali development and water washing.
(B-4) Immerse in an aqueous solution containing fluoride ions.
(B-5) Unnecessary portions of the conductive layer are removed by shower water washing.
(B-6) The photoresist on the conductive layer is removed by dipping in an organic solvent or a strong alkaline aqueous solution.
(B-7) Wash with water, air blow, and dry at 50-120 ° C.

  In addition, said drying and heat processing of (A-4) are performed as needed. When the adhesion between the conductive layer and the inorganic oxide layer is reduced due to the permeation of the alkaline developer, the adhesion can be improved by performing this treatment, and the subsequent steps can be performed stably. .

  The pattern shape of the conductive layer in the present invention is determined by the application. For example, a pattern that removes only the periphery of a rectangular conductive substrate, a pattern that forms a line electrode, a pattern that leaves a pseudo electrode between line electrodes, a pattern that provides a triangular or rhombus pad on the line electrode, etc. However, the present invention is not limited to these, and various patterns can be formed.

  The conductive substrate in the present invention can be used for transparent electrodes or line electrodes of touch panels, electronic paper, photovoltaic elements, organic EL elements, liquid crystal display elements and the like. For example, in a capacitive touch panel, two conductive substrates are used. An X electrode base material and a Y electrode base material are formed, both are bonded, and used by being laminated on the upper layer of a screen such as a liquid crystal display. In addition, at least two conductive substrates are used for passive electronic paper.

Hereinafter, the conductive film pattern forming method using the present invention will be specifically described based on examples. However, the present invention is not limited to the following examples.
(1) Method of measuring pH of etchant The pH of the etchant was measured at 20 ° C. using a pH tester (Checker / HI90103, manufactured by Hanna Instruments Inc.).
(2) Evaluation method of pattern shape after patterning The evaluation of the substrate on which the pattern forming operation was performed was performed using a microscope observation (manufactured by Keyence Co., Ltd., surface shape measuring microscope VF7500) with a magnification of 250 to 1,250 times. And the line width of the pattern was measured.
[Production Example of Inorganic Oxide Layer 1]
40 g of n-butyl silicate and 20 g of ethanol were placed in a 100 mL plastic container and stirred for 30 minutes, 10 g of 0.1N hydrochloric acid aqueous solution was added, stirred for 2 hours, and allowed to stand at 4 ° C. for 12 hours. The solution was prepared by diluting with a mixed solution of isopropyl alcohol and methyl ethyl ketone so that the solid concentration was 0.1% by mass. This liquid is applied onto the conductive layer using a wire bar # 8, dried in a 125 ° C. dryer for 1 minute, dehydrated and condensed, and an inorganic oxide layer 1 mainly composed of silica via a sol-gel method. Formed.
[Production Example of Inorganic Oxide Layer 2]
A suitable amount of polysilicate solution (manufactured by Ryowa Co., Ltd., Mega Aqua Hydrophilic DM Coat: DM-30-26G-N1) is dropped on the base material, applied using wire bar # 8, and dried in an 80 ° C. dryer. The inorganic oxide layer 2 mainly composed of silica was formed by allowing the mixture to stand for 1 minute for dehydration condensation.
[Production Example of Inorganic Oxide Layer 3]
Alumina particles having a diameter of about 40 nm are added and dispersed in the solution described in the preparation example of the inorganic oxide layer 1, and an appropriate amount of this liquid is dropped on the base material, and applied using a wire bar # 8. It left still for 1 minute in a 80 degreeC drying machine, and formed the inorganic oxide layer 3 which contains an alumina particle which has a silica as a main component.
[Production Example of Carbon Nanotube Conductive Layer 1]
The conductive layer of CNT was produced by the following operation.

  First, a catalyst for CNT synthesis was prepared. About 24.6 g of iron (III) ammonium citrate (manufactured by Wako Pure Chemical Industries, Ltd.) was dissolved in 6.2 kg of ion-exchanged water, and magnesium oxide (manufactured by Iwatani Chemical Industry Co., Ltd., MJ-) was dissolved in this solution. About 1,000 g of 30) was added, vigorously stirred for 60 minutes with a stirrer, and the resulting suspension was introduced into a 10 L autoclave vessel. At this time, 0.5 kg of ion exchange water was used as a washing solution, and both were added to the autoclave container. The autoclave was sealed and heated to 160 ° C. and held for 6 hours. Thereafter, the autoclave container was allowed to cool, the slurry-like cloudy substance was taken out from the container, excess water was filtered off by suction filtration, and a small amount of water contained in the filtered product was dried in a 120 ° C. drier. The obtained solid was finely divided in a mortar, and a sieve having a particle size in the range of 20 to 32 mesh was collected using a sieve to obtain a catalyst for CNT synthesis. In addition, iron contained in this catalyst was 0.39 mass% from the EDX analysis result.

  CNTs were then synthesized by chemical vapor deposition.

  The catalyst 132g was introduced onto a quartz sintered plate at the center of a cylindrical reactor installed in the vertical direction. While heating the catalyst layer until the temperature in the reaction tube reaches about 860 ° C., nitrogen gas is supplied from the bottom of the reactor toward the top of the reactor using a mass flow controller at 16.5 L / min. Circulated to pass through. Thereafter, while supplying nitrogen gas, methane gas was further introduced at 0.78 L / min for 60 minutes using a mass flow controller, and the gas was passed through the catalyst body layer for reaction. The contact time (W / F) obtained by dividing the mass of the solid catalyst body by the flow rate of methane at this time was 169 min · g / L, and the linear velocity of the gas containing methane was 6.55 cm / sec. While the introduction of methane gas was stopped and nitrogen gas was passed through 16.5 L / min, the quartz reaction tube was cooled to room temperature, and the catalyst-attached carbon nanotube composition on the quartz sintered plate was recovered.

  Next, the catalyst was removed. 115 g of the catalyst-attached carbon nanotube composition was put in 2,000 mL of a 4.8N hydrochloric acid aqueous solution, and stirred for 1 hour to dissolve iron as a catalyst metal and MgO as its support. The obtained black suspension was filtered, and the filtered product was again put into 400 mL of a 4.8N hydrochloric acid aqueous solution, stirred and filtered, and subjected to de-MgO treatment. This operation was repeated three times to obtain a carbon nanotube composition from which the catalyst was removed. This carbon nanotube composition was put into concentrated nitric acid (manufactured by Wako Pure Chemical Industries, Ltd., grade 1, Assay 60-61 mass%) having a mass of about 300 times. Thereafter, the mixture was heated to reflux with stirring in an oil bath at about 140 ° C. for 25 hours. After heating to reflux, a nitric acid solution containing the carbon nanotube-containing composition was diluted with ion-exchanged water three times and suction filtered. After washing with ion-exchanged water until the suspension of the filtered material became neutral, the carbon nanotube composition in a wet state containing water was stored. When this carbon nanotube composition was observed with a high-resolution transmission electron microscope, the ratio of double-walled carbon nanotubes was 90%.

  Next, a carbon nanotube dispersion was prepared. Carbon nanotube-containing composition in the above wet state (25 mg in terms of dry mass), 5 g of sodium carboxymethylcellulose aqueous solution (Daicel Finechem Co., Ltd., Daicel 1140, weight average molecular weight 450,000, concentration 1% by mass, solid content 50 mg ), 6.7 g of zirconia beads (manufactured by Toray Industries, Inc., Treceram, bead size: 0.8 mm) was added to the container, and the pH was adjusted to 10 using a 28% by mass aqueous ammonia solution (manufactured by Kishida Chemical Co., Ltd.). This container was shaken for 2 hours using a vibration mill to obtain a carbon nanotube paste. Ion exchange water was added to the carbon nanotube paste to dilute the carbon nanotube concentration to 0.15% by mass, and the aqueous solution was adjusted to pH 10 by adding 28% by mass aqueous ammonia again to 10 g of the diluted solution. The aqueous solution was ice-cooled and kept at 10 ° C. or lower, and dispersion treatment was performed for 1.5 minutes at an output of 20 W using an ultrasonic homogenizer. The obtained liquid was centrifuged at 10,000 G for 15 minutes with a high-speed centrifuge to obtain 9 g of a carbon nanotube dispersion.

Next, a carbon nanotube layer was formed. Ion exchange water is added to the carbon nanotube dispersion to adjust to 0.04% by mass, dropped onto the substrate with the inorganic oxide layer, and coated using a wire bar # 8 at 80 ° C. The carbon nanotube conductive layer 1 was formed by allowing it to stand for 1 minute.
[Production Example of Tin Oxide Conductive Layer 2]
An aqueous dispersion of antimony oxide-doped tin oxide (manufactured by Mitsubishi Materials Electronics Chemical Co., Ltd., TDL-1, antimony oxide-doped tin oxide concentration 17% by mass) is dropped on the substrate with the inorganic oxide layer, It apply | coated using the wire bar, and left still for 1 minute to 80 degreeC drying machine, and the antimony dope tin oxide electrically conductive layer 2 was formed.
[Production Example of Graphene Conductive Layer 3]
An aqueous dispersion of graphene (NanoIntegris, PureSheetsMONO, solid content concentration: 0.005% by mass) is dropped onto the substrate with the inorganic oxide layer, applied using a wire bar, and dried at 80 ° C. The graphene conductive layer 3 was formed by leaving it in the machine for 1 minute and repeating this 10 times.
[Preparation Example of Conductive Polymer Conductive Layer 4]
An aqueous dispersion of PEDOT / PSS, which is a conductive polymer (manufactured by Nagase Chemtex Co., Ltd., Denatron P-502S, solid content concentration 3% by mass) is dropped on the substrate with an inorganic oxide layer, It apply | coated using the wire bar and left still for 1 minute in a 80 degreeC drying machine, and the conductive polymer conductive layer 4 was formed.
[Production Example of Silver Nanocolloid Conductive Layer 5]
An aqueous dispersion of silver nanocolloid (manufactured by Mitsubishi Materials Electronics Chemical Co., Ltd., A-1, silver nanocolloid concentration 10% by mass) is dropped onto the substrate with the inorganic oxide layer, and a wire bar is used. The silver nanocolloid conductive layer 5 was formed by leaving it to stand in a dryer at 80 ° C. for 1 minute.
[Example of preparation of sol-gel silica protective layer]
40 g of n-butyl silicate and 20 g of ethanol were placed in a 100 mL plastic container and stirred for 30 minutes, 10 g of 0.1N hydrochloric acid aqueous solution was added, stirred for 2 hours, and allowed to stand at 4 ° C. for 12 hours. A protective layer solution was prepared by diluting with a mixed solution of isopropyl alcohol and methyl ethyl ketone so that the solid concentration was 0.1% by mass. This liquid was applied onto the conductive layer using a wire bar # 8 and dried in a 125 ° C. dryer for 1 minute to form a protective layer.
[L / S resolution evaluation pattern shape]
A pattern in which 5 to 10 straight lines having the same line width (L) and space width (S) were arranged in parallel was formed. L / S scales are 200 μm / 200 μm, 150 μm / 150 μm, 100 μm / 100 μm, 50 μm / 50 μm, 40 μm / 40 μm, 30 μm / 30 μm, 25 μm / 25 μm, 20 μm / 20 μm, 15 μm / 15 μm, 10 μm / 10 μm, 6 μm / 6 μm. It was.
[Dry film resist pattern formation example]
A dry film resist (manufactured by Asahi Kasei E-Materials Co., Ltd., SUNFORT / AQ209A) is placed on the surface of the conductive substrate with an inorganic oxide layer, passed through a hot roll press set at 105 ° C., and the dry film resist is laminated. did. This was cut to a size of 4 cm square, exposed to 80 mJ / cm ² through the photomask having the above-mentioned L / S resolution evaluation pattern, and immersed in an aqueous solution of 1% by mass of sodium carbonate to obtain a resist pattern. Since the dry film resist is a photo-curing type, a photomask having a shape that exposes the pattern forming portion and shields the development removed portion is used.
[Formation example of coating type positive resist pattern]
A conductive substrate with an inorganic oxide layer is cut into 4 cm square, and a positive photoresist (Rohm and Haas Co., Ltd., LC100) is dropped on this surface, and a spin coater (Mikasa Co., Ltd., Spin The coating was carried out with a coater 1H-D3) at 1,000 rpm for 30 seconds, and allowed to stand on a hot plate set at 100 ° C. for 30 minutes to dry. This is exposed to 100 mJ / cm ² through the above-described counter electrode pattern or photomask having an L / S resolution evaluation pattern, and immersed in an aqueous solution of 2.38% by mass of tetramethylammonium hydride (hereinafter, TMAH) to form a resist. Got a pattern. Since the positive resist is a light solubilizing type, a photomask having a shape in which the pattern forming portion is shielded from light and the development removed portion is exposed is used.

[Risk level assessment]
The risk of impact on the human body when handling an etchant was evaluated by dividing it from level I with a low level of risk to level III with a high level of risk. The evaluation items were three items: (1) whether it was larger or smaller than pH 1 and smaller than pH 12, (2) the volatility of acid gas or basic gas, and (3) the magnitude of acute toxicity. Etchants on the low risk side for all three items were assigned a risk level I. An etchant with only one item on the high risk side was assigned a risk level II. Etchants that apply to two or more items are designated as Danger Level III. The risk level of the etchant preferably used in the present invention was set to level I.
Example 1
An inorganic oxide layer 1 mainly composed of silica and a carbon nanotube conductive layer 1 are formed in this order on a PET film (Toray Industries, Inc., U46, thickness 125 μm) via a sol-gel method. A conductive substrate with an object underlayer was obtained. A resist pattern corresponding to the L / S resolution evaluation pattern was formed on this conductive substrate in accordance with the above-mentioned [Dry Film Resist Pattern Formation Example]. Here, the conductive substrate was placed on a hot plate and dried after development at 100 ° C. for 3 minutes. Next, an etchant having a concentration of 0.1% by mass of sulfuric acid and 0.1% by mass of ammonium fluoride was prepared. The pH of this etchant was 2.5. The conductive substrate was immersed in an etchant heated to 40 ° C. for 60 seconds, immersed in pure water for 5 seconds, and washed with shower water using a sprayer. Next, the resist was peeled off by immersing in methyl cellosolve acetate (hereinafter referred to as MCA) for 60 seconds, immersed in pure water and washed with water.

When the obtained conductive pattern was observed with a microscope, the L / S resolution evaluation pattern was L / S = 20 μm / 20 μm and a pattern coarser than this was well formed. The risk level of the etchant was in the range at pH 2.5, the volatility was small, and the acute toxicity was small, so the risk level was I.
(Example 2)
A protective layer using an inorganic oxide layer 1, a carbon nanotube conductive layer 1, and an inorganic oxide layer 1 is formed in this order on a PET film (Toray Industries, Inc., U46, thickness 125 μm). A conductive substrate with a base layer was obtained. A resist pattern corresponding to the L / S resolution evaluation pattern was formed on this conductive substrate in accordance with the above-mentioned [Dry Film Resist Pattern Formation Example]. Here, the conductive substrate was placed on a hot plate and dried after development at 100 ° C. for 3 minutes. Next, an etchant having a concentration of 1% by mass of sulfuric acid and 0.1% by mass of ammonium fluoride was prepared. The pH of this etchant was 1.8. The conductive substrate was immersed in an etchant heated to 40 ° C. for 60 seconds, immersed in pure water for 5 seconds, and washed with shower water using a sprayer. Next, the resist was peeled off by immersing in MCA for 60 seconds, immersed in pure water and washed with water.

When the obtained conductive pattern was observed with a microscope, the L / S resolution evaluation pattern was L / S = 20 μm / 20 μm and a pattern coarser than this was well formed. The risk level of the etchant was in the range at pH 1.8, the volatility was small, and the acute toxicity was small, so the risk level was I.
(Example 3)
The same operation as in Example 2 was performed except that the inorganic oxide layer was changed to the inorganic oxide layer 2 formed from the polysilicate raw material. When the obtained conductive pattern was observed with a microscope, the L / S resolution evaluation pattern was L / S = 20 μm / 20 μm and a pattern coarser than this was well formed. When the surface form of the conductive layer removal portion was observed with a laser microscope VK9710 manufactured by Keyence Corporation, it was the same form as the PET film surface substrate, and peeling occurred at the interface between the inorganic oxide layer and the PET film surface. I understood. The risk level of the etchant was in the range at pH 1.8, the volatility was small, and the acute toxicity was small, so the risk level was I.
Example 4
The same operation as in Example 3 was performed except that the photoresist was changed to the above-described coating type positive resist. When the obtained conductive pattern was observed with a microscope, the L / S resolution evaluation pattern was L / S = 10 μm / 10 μm and a coarser pattern was well formed. The risk level of the etchant was in the range at pH 1.8, the volatility was small, and the acute toxicity was small, so the risk level was I. When the surface form of the conductive layer removal portion was observed with a laser microscope VK9710 manufactured by Keyence Corporation, it was the same form as the PET film surface substrate, and peeling occurred at the interface between the inorganic oxide layer and the PET film surface. I understood.
(Example 5)
The same operation as in Example 4 was performed except that soda lime glass having a thickness of 1.1 mm was used as the base material and a protective layer was not provided. When the obtained conductive pattern was observed with a microscope, the L / S resolution evaluation pattern was L / S = 10 μm / 10 μm and a coarser pattern was well formed. The risk level of the etchant was in the range at pH 1.8, the volatility was small, and the acute toxicity was small, so the risk level was I.
(Example 6)
The same operation as in Example 4 was performed except that soda lime glass having a thickness of 1.1 mm was used as the base material. When the obtained conductive pattern was observed with a microscope, the L / S resolution evaluation pattern was L / S = 10 μm / 10 μm and a coarser pattern was well formed. The risk level of the etchant was in the range at pH 1.8, the volatility was small, and the acute toxicity was small, so the risk level was I.
(Example 7)
The same operation as in Example 3 was performed except that a polyimide film (manufactured by Toray DuPont, Kapton 100V) was used as the base material. When the obtained conductive pattern was observed with a microscope, the L / S resolution evaluation pattern was L / S = 20 μm / 20 μm and a pattern coarser than this was well formed. The risk level of the etchant was in the range at pH 1.8, the volatility was small, and the acute toxicity was small, so the risk level was I.
(Example 8)
The same operation as in Example 3 was performed except that the inorganic oxide layer was changed to the inorganic oxide layer 3 described above. When the obtained conductive pattern was observed with a microscope, the L / S resolution evaluation pattern was L / S = 20 μm / 20 μm and a pattern coarser than this was well formed. The risk level of the etchant was in the range at pH 1.8, the volatility was small, and the acute toxicity was small, so the risk level was I.
Example 9
The same operation as in Example 4 was performed except that the conductive layer was changed to the antimony-doped tin oxide conductive layer 2 and the protective layer was not provided. When the obtained conductive pattern was observed with a microscope, the L / S resolution evaluation pattern was L / S = 10 μm / 10 μm and a coarser pattern was well formed. The risk level of the etchant was in the range at pH 1.8, the volatility was small, and the acute toxicity was small, so the risk level was I.
(Example 10)
The same operation as in Example 4 was performed except that the conductive layer was changed to the graphene conductive layer 3 and the protective layer was not provided. When the obtained conductive pattern was observed with a microscope, the L / S resolution evaluation pattern was L / S = 20 μm / 20 μm and a pattern coarser than this was well formed. The risk level of the etchant was in the range at pH 1.8, the volatility was small, and the acute toxicity was small, so the risk level was I.
(Example 11)
The same operation as in Example 4 was performed except that the conductive layer was changed to the conductive polymer conductive layer 4 and the protective layer was not provided. When the obtained conductive pattern was observed with a microscope, the L / S resolution evaluation pattern was L / S = 20 μm / 20 μm and a pattern coarser than this was well formed. The risk level of the etchant was in the range at pH 1.8, the volatility was small, and the acute toxicity was small, so the risk level was I.
(Example 12)
The same operation as in Example 4 was performed except that the conductive layer was changed to the silver nanocolloid conductive layer 5 and the protective layer was not provided. When the obtained conductive pattern was observed with a microscope, the L / S resolution evaluation pattern was L / S = 20 μm / 20 μm and a pattern coarser than this was well formed. The risk level of the etchant was in the range at pH 1.8, the volatility was small, and the acute toxicity was small, so the risk level was I.
(Example 13)
An etchant having a concentration of 1% by mass of sulfuric acid and 0.1% by mass of sodium fluoride was prepared, and the same operation as in Example 4 was performed except that this etchant was used. The pH of this etchant was 1.8. When the obtained conductive pattern was observed with a microscope, the L / S resolution evaluation pattern was L / S = 10 μm / 10 μm and a coarser pattern was well formed. The risk level of the etchant was in the range at pH 1.8, the volatility was small, and the acute toxicity was small, so the risk level was I.
(Example 14)
An etchant having a concentration of 1% by mass of toluenesulfonic acid and 0.1% by mass of potassium fluoride was prepared, and the same operation as in Example 4 was performed except that this etchant was used. The pH of this etchant was 1.5. When the obtained conductive pattern was observed with a microscope, the L / S resolution evaluation pattern was L / S = 10 μm / 10 μm and a coarser pattern was well formed. The risk level of the etchant was in the range at pH 1.5, the volatility was small, and the acute toxicity was small, so the risk level was I.
(Example 15)
The same operation as in Example 4 was performed except that an etchant having a concentration of 1% by mass of ammonium fluoride was prepared, this etchant was used, the etchant liquid temperature was 50 ° C., and the etching time was 180 seconds. It was. The pH of this etchant was 6.5. When the obtained conductive pattern was observed with a microscope, the L / S resolution evaluation pattern was L / S = 30 μm / 30 μm and a pattern coarser than this was well formed. The etchant risk level was in the range at pH 6.5, the volatility was low, and the acute toxicity was low, so the risk level was I.
(Example 16)
Prepared an etchant with a concentration of 0.1% by weight of sodium carbonate and 1% by weight of ammonium fluoride. This etchant was used except that the etchant temperature was 60 ° C. and the etching time was 180 seconds. The same operation as in Example 4 was performed. The pH of this etchant was 11. When the obtained conductive pattern was observed with a microscope, the L / S resolution evaluation pattern was L / S = 40 μm / 40 μm and a pattern coarser than this was well formed. The risk level of the etchant was in the range at pH 11, the volatility was small, and the acute toxicity was small, so the risk level was I.
(Example 17)
The same operation as in Example 3 was performed except that acetone was used instead of MCA for stripping the resist. When the obtained conductive pattern was observed with a microscope, the L / S resolution evaluation pattern was L / S = 20 μm / 20 μm and a pattern coarser than this was well formed. The risk level of the etchant was in the range at pH 1.8, the volatility was small, and the acute toxicity was small, so the risk level was I.
(Example 18)
The same operation as in Example 3 was performed except that a 1% by weight aqueous solution of sodium hydroxide was used instead of MCA for stripping the resist. When the obtained conductive pattern was observed with a microscope, the L / S resolution evaluation pattern was L / S = 20 μm / 20 μm and a pattern coarser than this was well formed. The risk level of the etchant was in the range at pH 1.8, the volatility was small, and the acute toxicity was small, so the risk level was I.
(Comparative Example 1)
The same operation as in Example 3 was performed except that the inorganic oxide layer was not provided, the protective layer was not provided, the etchant liquid temperature was 50 ° C., and the etching time was 600 seconds. The conductive layer was not etched, and an L / S resolution evaluation pattern could not be obtained. The risk level of the etchant was in the range at pH 1.8, the volatility was small, and the acute toxicity was small, so the risk level was I.
(Comparative Example 2)
The same operation as in Example 3 was performed except that the inorganic oxide layer was not provided, the etchant liquid temperature was 50 ° C., and the etching time was 600 seconds. The conductive layer was not etched, and an L / S resolution evaluation pattern could not be obtained. The risk level of the etchant was in the range at pH 1.8, the volatility was small, and the acute toxicity was small, so the risk level was I.
(Comparative Example 3)
The same operation as in Example 3 was performed, except that the inorganic oxide layer was not provided, the etchant was changed to 60% by mass sulfuric acid, the liquid temperature was 50 ° C., and the etching time was 600 seconds. The pH of this etchant was 1. The conductive layer was not etched, and an L / S resolution evaluation pattern could not be obtained. In addition, due to the high concentration of sulfuric acid, careful handling was required. The risk level of the etchant was out of range at pH 1, the volatility was small, and the acute toxicity was small, so the risk level was II.
(Comparative Example 4)
The same operation as in Example 3 was performed, except that the inorganic oxide layer was not provided, the etchant was changed to 3% by mass sodium hydroxide, the liquid temperature was 50 ° C., and the etching time was 600 seconds. The pH of this etchant was 14. Although the conductive layer was partially etched, an L / S resolution evaluation pattern could not be obtained. In addition, since the etchant was a strong alkaline aqueous solution, careful handling was required. The risk level of the etchant was out of range at pH 14, the volatility was small, and the acute toxicity was small, so the risk level was II.
(Comparative Example 5)
An operation similar to that of Example 3 was performed except that an aqueous solution of 1% by mass of sulfuric acid was prepared, this solution was used as an etchant, and the etching time was 90 seconds. The pH of this aqueous solution was 1. Although the conductive layer was partially etched, an L / S resolution evaluation pattern could not be obtained. The risk level of the etchant was in the range at pH 1.8, the volatility was small, and the acute toxicity was small, so the risk level was I.
(Comparative Example 6)
An aqueous solution of 60% by mass sulfuric acid was prepared, this solution was used as an etchant, and the same operation as in Example 3 was performed except that the etching time was 45 seconds. The pH of this aqueous solution was 1. In the obtained L / S resolution evaluation pattern, the remaining film and disconnection were mixed in the coarsest L / S = 200 μm / 200 μm pattern. In addition, due to the high concentration of sulfuric acid, careful handling was required. The risk level of the etchant was out of range at pH 1, the volatility was small and the acute toxicity was small, so the risk level was II.
(Comparative Example 7)
An aqueous solution containing 75% by mass of sulfuric acid was prepared, this solution was used as an etchant, and the same operation as in Example 3 was performed except that the etching time was 45 seconds. The pH of this aqueous solution was 1. The obtained L / S resolution evaluation pattern was remarkably peeled, and disconnection was recognized even in the roughest L / S = 200 μm / 200 μm pattern. In addition, due to the high concentration of sulfuric acid, careful handling was required. The risk level of the etchant was out of range at pH 1, the volatility was small and the acute toxicity was small, so the risk level was II.
(Comparative Example 8)
An aqueous solution containing 1% by mass of sodium carbonate was prepared, this solution was used as an etchant, and the same operation as in Example 3 was performed except that the solution temperature was 50 ° C. and the etching time was 180 seconds. The pH of this aqueous solution was 11.9. The obtained L / S resolution evaluation pattern was remarkably peeled, and disconnection was recognized even in the roughest L / S = 200 μm / 200 μm pattern. The risk level of the etchant was in the range at pH 11.9, the volatility was low, and the acute toxicity was low, so the risk level was I.
(Comparative Example 9)
The same operation as in Example 3 was performed except that a 2.4% by mass aqueous solution of TMAH was prepared and this solution was used as an etchant. The pH of this aqueous solution was 13.8. The obtained L / S resolution evaluation pattern was remarkably peeled, and disconnection was recognized even in the roughest L / S = 200 μm / 200 μm pattern. Also, since the etchant was a strong alkaline aqueous solution, careful handling was required. The risk level of the etchant was out of range at pH 13.8, the volatility was small, and the acute toxicity was small, so the risk level was II.
(Comparative Example 10)
An aqueous solution containing 3% by mass of sodium hydroxide was prepared, this solution was used as an etchant, and the same operation as in Example 3 was performed except that the etching time was 30 seconds. The pH of this aqueous solution was 14. The conductive layer was completely peeled off by shower water washing after etching, and a conductive pattern could not be obtained. Also, since the etchant was a strong alkaline aqueous solution, careful handling was required. The risk level of the etchant was out of range at pH 14, the volatility was small, and the acute toxicity was small, so the risk level was II.
(Comparative Example 11)
A mixed liquid of 36% by mass hydrochloric acid and 40% by mass ferric chloride was prepared, and the same operation as in Example 3 was performed except that this liquid was used as an etchant. The pH of this aqueous solution was 0.5. Only a part of the conductive layer was removed, resulting in poor etching. Moreover, since the pH of the etchant was less than 1, careful handling was required, and volatile gas with high oxidizability was generated, so the surrounding equipment was corroded. The risk level of the etchant was out of range at pH 0.5, the volatility was high, and the acute toxicity was low, so the risk level was III.
(Comparative Example 12)
An aqueous solution containing 10% by mass of hydrogen fluoride was prepared, this solution was used as an etchant, and the same operation as in Example 3 was performed except that the etching time was set to 15 seconds. In the obtained L / S resolution evaluation pattern, L / S = 20 μm / 20 μm and a pattern coarser than this were well formed. However, when handling an aqueous hydrogen fluoride solution, it is necessary to completely avoid contact with the skin and inhalation of vapors. Therefore, wear non-permeable protective clothing, a face shield, and a gas mask. The work was carried out on the draft work table. Therefore, it was difficult to perform accurate work. The etchant risk level was in the range at pH 3, but the risk level was III due to its high volatility and high acute toxicity.

Hereinafter, Tables 1 and 2 show production conditions of Examples and Comparative Examples, and Table 3 shows evaluation results.
(Comparative Example 13)
A protective layer using an inorganic oxide layer 2, a carbon nanotube conductive layer 1, and an inorganic oxide layer 1 is formed in this order on a PET film (Toray Industries, Inc., U46, thickness 125 μm). A conductive substrate with a base layer was obtained. Ten linear patterns having a width of the conductive removal portion of 20 μm were formed on the conductive surface of the conductive substrate by a laser etching method using an ultraviolet laser. When the conductive layer-removed portion of this space was observed with a laser microscope VK9710 manufactured by Keyence Corporation, it was confirmed that the PET film surface was removed. Moreover, the waste of the conductive layer removed by the laser was scattered in some places, and some existed in the conductive layer removal part. When conduction through this linear pattern was confirmed, it was 0 linear patterns confirmed to be in an insulating state of 40 MΩ or more.
(Example 19)
The substrate for the X electrode and the substrate for the Y electrode were patterned by the method of Example 3. When a drive circuit for a capacitive touch panel is attached to a panel on which these conductive substrates are bonded and the surface is pressed with a finger, the circuit recognizes the pressed point and can operate as a capacitive touch panel. It could be confirmed.

101 Substrate 102 Inorganic oxide layer 103 Conductive layer 104 Protective layer 105 Resist

Claims (7)

A step of forming a resist layer on a part of the outermost layer of the conductive substrate in which at least the substrate, the inorganic oxide layer and the conductive layer are formed in this order; and contacting the conductive substrate with an aqueous solution containing fluoride ions, A method for producing a patterned conductive substrate, comprising a step of patterning the conductive layer by removing the conductive layer together with the inorganic oxide layer in a portion where a resist is not formed. The method for producing a patterned conductive substrate according to claim 1, wherein the aqueous solution containing fluoride ions is an aqueous solution of at least one of an alkali metal fluoride and an ammonium salt of fluoride. The method for producing a patterned conductive substrate according to claim 1 or 2, wherein the pH of the aqueous solution containing fluoride ions is 1 to 7. The method for producing a patterned conductive substrate according to claim 1, wherein the inorganic oxide layer is a layer containing silica and / or alumina. The method for producing a patterned conductive substrate according to claim 1, wherein the conductive layer contains carbon nanotubes. The conductive base material patterned by the manufacturing method according to any one of claims 1 to 4, wherein the conductive layer contains carbon nanotubes, and the conductive layer removal portion is in a state where the surface of the base material is exposed. A touch panel using the patterned conductive substrate according to claim 6.

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