Etched product and method for manufacturing etched product

Abstract

To provide an etched product that is free from poor appearance even when being applied with plating, and to provide a method for manufacturing an etched product.SOLUTION: An etched product to be applied with plating comprises copper or a copper alloy and includes a 4-13 mass% of a triazole-based compound based on 100 mass% of copper at a surface layer in a 1 nm depth direction from an outermost surface.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to an etched product and a method for manufacturing the etched product.

Background Art

[0002] Conventionally, the performance of copper has been improved by alloying. In the field of the electronics industry, copper is used as wiring in printed wiring boards, IC lead frames, springs for camera modules, etc. In order to increase the strength and conductivity of the wiring, various elements such as manganese, nickel, titanium, tin, zinc, and zirconium are added to copper to alloy it. Specific copper alloys include phosphor bronze, titanium copper, Corson alloy, beryllium copper, etc.

[0003] Copper alloys are etched and used as wiring. For example, dry film resist is used to form a wiring pattern by etching a copper alloy substrate. The dry film resist may contain a triazole-based compound in order to impart storage stability to the resist or to improve the adhesiveness to the copper alloy.

[0004] Patent Documents 1 and 2 describe that the resist contains a triazole-based compound in order to improve storage stability. Patent Documents 3 to 5 describe that the resist contains a triazole-based compound in order to improve the adhesiveness to a copper substrate.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

[0006] Triazole compounds remain in the form of a chemical bond with the copper alloy even after the resist is peeled off after etching. After etching, the copper alloy is subjected to gold plating to improve conductivity and protect the surface from oxidation. When a triazole compound remains on the surface of the copper alloy, the nickel plating becomes uneven when nickel plating is applied as a base treatment for gold plating. Therefore, when gold plating is applied, appearance defects such as unevenness occur, affecting the quality.

[0007] The present invention has been made in view of the above circumstances, and an object thereof is to provide an etched product that does not cause appearance defects even when plated, and a method for manufacturing an etched product. [Means for Solving the Problems]

[0008] The present invention has the following aspects. [1] An etched product to be plated, which is made of copper or a copper alloy, and in the surface layer having a depth of 1 nm from the outermost surface, when the mass of copper is 100, the mass of the triazole compound is 4 or more and 13 or less. An etched product. [2] The etched product according to [1], wherein the triazole compound is benzotriazole. [3] The etched product according to [1] or [2], wherein the plating is gold plating. [4] The etched product according to [3], wherein nickel plating is applied as a base treatment for the gold plating. [5] A method for manufacturing an etched product to be plated, A method for manufacturing an etched product, which is made of copper or a copper alloy and in the surface layer with a depth of 1 nm from the outermost surface, when the mass of copper is 100, the mass of the triazole compound is 4 or more and 13 or less. [6] The method for manufacturing an etched product according to [5], wherein the triazole compound is benzotriazole. [7] The method for manufacturing an etched product according to [5] or [6], wherein the plating treatment is gold plating. [8] The method for manufacturing an etched product according to [7], which has a step of performing nickel plating as a pretreatment for the gold plating. [9] The method for manufacturing an etched product according to [5], wherein the mass of the copper and the mass of the triazole compound are measured by time-of-flight secondary ion mass spectrometry.

Effect of the Invention

[0009] According to the present invention, it is possible to provide an etched product that does not cause appearance defects even when subjected to plating treatment, and a method for manufacturing an etched product.

Embodiments for Carrying Out the Invention

[0010] [Etched Product] An etched product according to an embodiment of the present invention is an etched product subjected to plating treatment, which is made of copper or a copper alloy, and in the surface layer with a depth of 1 nm from the outermost surface, when the mass of copper is 100, the mass of the triazole compound is 4 or more and 13 or less.

[0011] Examples of the copper constituting the etched product include those with a purity of 90% or more. Examples of the copper alloy constituting the etched product include copper, titanium copper, beryllium copper, phosphor bronze, Corson-based copper alloy, etc.

[0012] In the etched product of the present embodiment, in the surface layer with a depth of 1 nm in the depth direction from the outermost surface of copper or a copper alloy, when the mass of copper is 100, the mass of the triazole-based compound is 4 or more and 13 or less, preferably 6 or more and 11 or less, and more preferably 7 or more and 10 or less. When the mass of the triazole-based compound is less than 4, unevenness due to the oxide generated on the surface of copper or a copper alloy occurs partially or entirely in the nickel plating treatment, which is the base treatment before gold plating. When the mass of the triazole-based compound exceeds 13, unevenness due to the triazole-based compound remaining on the surface of copper or a copper alloy occurs partially or entirely in the nickel plating treatment, which is the base treatment before gold plating.

[0013] As a method for detecting and analyzing the triazole-based compound remaining on the outermost surface of copper or a copper alloy after etching, examples include time-of-flight secondary ion mass spectrometry (TOF-SIMS: Time-of-Flight Secondary Ion Mass Spectrometry), energy dispersive X-ray spectroscopy (EDS: Energy Dispersive X-Ray Spectroscopy), Auger electron spectroscopy (AES: Auger Electron Spectroscopy), X-ray photoelectron spectroscopy (XPS: X-Ray Photo Electron Spectroscopy), and the like. Time-of-flight secondary ion mass spectrometry has a detection depth of 1 nm and a high detection sensitivity on the order of PPM, enabling the identification of thin film components. It can distinguish not only the element and chemical state but also the molecular structure, and has high qualitative accuracy. Energy dispersive X-ray spectroscopy has a detection depth of several μm and a detection sensitivity on the order of %, and the information obtained is only about the element. Auger electron spectroscopy has a detection depth of several nm and a detection sensitivity on the order of 0.1%, and the information obtained is only about the element. X-ray photoelectron spectroscopy has a detection depth of several nm and a detection sensitivity on the order of 0.1%, and the information obtained is about the element and chemical state. Among these analysis methods, the time-of-flight secondary ion mass spectrometry method, which can particularly analyze thin films and identify molecular structures, is the most effective. In the time-of-flight secondary ion mass spectrometry method, the mass of copper and the mass of the triazole-based compound can be measured in the surface layer with a depth of 1 nm from the outermost surface in the depth direction. The mass of benzotriazole measured by the time-of-flight secondary ion mass spectrometry method is the mass of benzotriazole (negative secondary ion C6H4N + ) when the mass of copper (positive secondary ion Cu - ) is set to 100.

[0014] The triazole-based compound is not particularly limited as long as it is included in the resist described below. However, benzotriazole is preferable because it can impart storage stability to the resist and has excellent adhesiveness to copper or copper alloy.

[0015] The plating treatment applied to the etched product of this embodiment is not particularly limited, and examples thereof include gold plating, silver plating, nickel plating, chromium plating, etc. When the etched product is used as a printed wiring board or an IC lead frame, gold plating is preferable because it has excellent corrosion resistance, conductivity, and solderability.

[0016] The thickness of the plating formed by the plating treatment is preferably 0.01 μm or more and 0.3 μm or less.

[0017] When the etched product of this embodiment is subjected to gold plating, it is preferable to perform nickel plating as an undercoat treatment for the gold plating on the etched product of this embodiment. By performing nickel plating as an undercoat treatment, the adhesion of the gold plating to the etched product is improved. In addition, by performing nickel plating, the heat resistance is improved and the diffusion of copper to the gold plating surface can be prevented.

[0018] The thickness of the nickel plating formed by the undercoat treatment is preferably 0.5 μm or more and 3 μm or less.

[0019] According to the etched product of the present embodiment, it is possible to provide an etched product that does not cause appearance defects even when plated.

[0020] [Manufacturing Method of Etched Product] A method for manufacturing an etched product according to an embodiment of the present invention is a method for manufacturing an etched product to be plated, comprising a step of manufacturing an etched product made of copper or a copper alloy and having a mass of a triazole-based compound of 4 or more and 13 or less in a surface layer of 1 nm in the depth direction from the outermost surface, where the mass of copper is 100 (hereinafter referred to as the "manufacturing step").

[0021] The manufacturing method of the etched product of the present embodiment may include a step of forming a photopolymerizable resin layer using a resist containing a triazole-based compound on a substrate made of copper or a copper alloy, exposing the photopolymerizable resin layer, and developing to form a resist pattern (hereinafter referred to as the "resist pattern forming step"); a step of etching the substrate on which the resist pattern is formed (hereinafter referred to as the "etching step"); a step of peeling the photopolymerizable resin layer from the substrate after etching is completed (hereinafter referred to as the "peeling step"); a step of treating the surface of the substrate from which the photopolymerizable resin layer has been peeled with an acid to reduce the residual amount of the triazole-based compound remaining on the surface of the substrate (hereinafter referred to as the "acid treatment step"); and a step of performing a base treatment on the substrate from which the photopolymerizable resin layer has been peeled (hereinafter referred to as the "base treatment step").

[0022] "Resist Pattern Forming Step" As the resist, a photopolymerizable resin composition is used. As the photopolymerizable resin composition, for example, a thermoplastic copolymer containing (a) an α,β-unsaturated carboxyl group-containing monomer as a copolymerization component, having an acid equivalent of 100 to 600 and a weight average molecular weight of 20,000 to 500,000, (b) an addition polymerizable monomer having at least one terminal ethylenic unsaturated group, (c) a photoinitiator, and (d) a triazole-based compound is used.

[0023] (a) The thermoplastic polymer contains a monomer having an α,β-unsaturated carboxyl group as a copolymerization component, and has an acid equivalent of 100 to 600 and a weight average molecular weight of 20,000 to 500,000. The carboxyl group in the thermoplastic polymer is necessary for the photopolymerizable resin composition to have developability and peelability with respect to an aqueous alkali solution. The acid equivalent is 100 or more from the viewpoint of ensuring compatibility with a coating solvent or other compositions, for example, a monomer, and is 600 or less from the viewpoint of maintaining developability and peelability. Here, the acid equivalent refers to the mass (gram) of a polymer having 1 equivalent of carboxyl groups therein. The measurement of the acid equivalent is performed, for example, by potentiometric titration with a 0.1 mol / L aqueous NaOH solution.

[0024] The weight average molecular weight is 20,000 or more from the viewpoint of maintaining the thickness of the photopolymerizable resin layer uniformly and obtaining resistance to a developer, and is 500,000 or less from the viewpoint of maintaining developability. The weight average molecular weight in this case is the weight average molecular weight measured using a calibration curve of a polystyrene standard sample by gel permeation chromatography (GPC).

[0025] The above thermoplastic polymer is generally obtained by copolymerizing one or more monomers each from among the following two types of monomers. The first monomer is a carboxylic acid or carboxylic anhydride having one polymerizable unsaturated group in the molecule. Examples of the carboxylic acid or carboxylic anhydride include (meth)acrylic acid, fumaric acid, cinnamic acid, crotonic acid, itaconic acid, maleic anhydride, maleic acid semi-ester, and the like.

[0026] The second monomer is non-acidic, has one polymerizable unsaturated group in the molecule, and is selected to maintain various properties such as the development of the photopolymerizable resin layer, resistance in the etching and plating processes, and the flexibility of the cured film. Examples of such monomers include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, iso-propyl (meth)acrylate, n-butyl (meth)acrylate, iso-butyl (meth)acrylate, tert-butyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylates. In addition, esters of vinyl alcohol such as vinyl acetate, (meth)acrylonitrile, styrene, or polymerizable styrene derivatives are also included. It can also be obtained by polymerizing only a carboxylic acid or acid anhydride having one polymerizable unsaturated group in the molecule.

[0027] The content of the (a) thermoplastic polymer in the photopolymerizable resin composition is preferably 20% by mass or more and 90% by mass or less, and more preferably 25% by mass or more and 70% by mass or less. When the content of the (a) thermoplastic polymer is 20% by mass or more, the alkali developability can be maintained. When the content of the (a) thermoplastic polymer is 90% by mass or less, the cured image formed by exposure can sufficiently exhibit the performance as a resist.

[0028] (b) As the addition polymerizable monomer having at least one terminal ethylenically unsaturated group, for example, 4-nonylphenyl heptaethylene glycol dipropylene glycol acrylate, 2-hydroxy-3-phenoxypropyl acrylate, phenoxy hexaethylene glycol acrylate, the reaction product of the semi-ester compound of phthalic anhydride and 2-hydroxypropyl acrylate and propylene oxide, 4-normal octylphenoxy pentapropylene glycol acrylate, 2,2-bis[{4-(meth)acryloxypolyethoxy}phenyl]propane, 1,6-hexanediol (meth)acrylate, 1,4-cyclohexanediol di(meth)acrylate, polypropylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polyoxyalkylene glycol di(meth)acrylate such as polyoxyethylene polyoxypropylene glycol di(meth)acrylate, 2-di(p-hydroxyphenyl)propane di(meth)acrylate, glycerol tri(meth)acrylate, pentaerythritol penta(meth)acrylate, trimethylolpropane triglycidyl ether tri(meth)acrylate, bisphenol A diglycidyl ether di(meth)acrylate, 2,2-bis(4-methacryloxypentaethoxyphenyl)propane, polyfunctional (meth)acrylate containing a urethane group such as the urethane compound of hexamethylene diisocyanate and nonapropylene glycol monomethacrylate, and isocyanuric acid ester compounds can be mentioned. These may be used alone or in combination of two or more.

[0029] In the photocurable resin composition, the content of the addition-polymerizable monomer (b) having at least one terminal ethylenically unsaturated group is preferably 5% by mass or more and 75% by mass or less, and more preferably 15% by mass or more and 70% by mass or less. When the content of the addition-polymerizable monomer (b) having at least one terminal ethylenically unsaturated group is 5% by mass or more, poor curing and delay of development time can be suppressed. When the content of the addition-polymerizable monomer (b) having at least one terminal ethylenically unsaturated group is 75% by mass or less, cold flow and delay of peeling of the cured resist can be suppressed.

[0030] (c) Examples of the triazole-based compound include 1,2,3-triazole, 1,2,4-triazole, benzotriazole, and the like. Among these, benzotriazole is preferable because it can impart storage stability to the resist and has excellent adhesiveness to copper or a copper alloy. Examples of benzotriazole include 1,2,3-benzotriazole, 1-chloro-1,2,3-benzotriazole, bis(N-2-ethylhexyl)aminomethylene-1,2,3-benzotriazole, bis(N-2-ethylhexyl)aminomethylene-1,2,3-tolyltriazole, bis(N-2-hydroxyethyl)aminomethylene-1,2,3-benzotriazole, and the like. Examples of carboxybenzotriazole include 4-carboxy-1,2,3-benzotriazole, 5-carboxy-1,2,3-benzotriazole, and the like. These may be used alone or in combination of two or more.

[0031] In the photocurable resin composition, the content of the triazole-based compound (c) is preferably 0.01% by mass or more and 3% by mass or less, and more preferably 0.05% by mass or more and 1% by mass or less. When the content of the triazole-based compound is 0.01% by mass or more, the resist has excellent storage stability and the photocurable resin layer has excellent adhesiveness to copper or a copper alloy. When the content of the triazole-based compound is 3% by mass or less, the sensitivity can be maintained well.

[0032] The photocurable resin composition may contain a photoinitiator. Examples of the photoinitiator include quinones such as 2-ethylanthraquinone, octaethylanthraquinone, 1,2-benzanthraquinone, 2,3-benzanthraquinone, 2-phenylanthraquinone, 2,3-diphenylanthraquinone, 1-chloroanthraquinone, 1,4-naphthoquinone, 9,10-phenanthraquinone, 2-methyl-1,4-naphthoquinone, 2,3-dimethylanthraquinone, 3-chloro-2-methylanthraquinone; aromatic ketones such as benzophenone, Michler's ketone [4,4'-bis(dimethylamino)benzophenone], 4,4'-bis(diethylamino)benzophenone; benzoin ethers such as benzoin, benzoin ethyl ether, benzoin phenyl ether, methyl benzoin, ethyl benzoin; N-phenylglycines such as benzyldimethylketal, benzyldiethylketal, N-phenylglycine, N-methyl-N-phenylglycine, N-ethyl-N-phenylglycine; combinations of thioxanthones and alkylaminobenzoic acids, for example, combinations of ethylthioxanthone and ethyl dimethylaminobenzoate, 2-chlorothioxanthone and ethyl dimethylaminobenzoate, isopropylthioxanthone and ethyl dimethylaminobenzoate; acridines such as 9-phenylacridine; oxime esters such as 1-phenyl-1,2-propanedione-2-o-benzoyloxime, 1-phenyl-1,2-propanedione-2-(o-ethoxycarbonyl)oxime.

[0033] The photocurable resin composition may contain coloring substances such as dyes and pigments. Examples of the coloring substances include phthalocyanine green, crystal violet, methyl orange, Nile blue 2B, Victoria blue, malachite green, basic blue 20, diamond green, etc.

[0034] The photopolymerizable resin composition may contain a color former so that a visible image can be formed by exposure. By adding a color former, it becomes possible to visually distinguish between the exposed area and the unexposed area, improving work efficiency. Examples of such color-forming dyes include leuco dyes. Examples of leuco dyes include leuco crystal violet, those obtained by combining a fluoran dye and a halogen compound, and the like. In addition to the aforementioned dyes, examples of halogen compounds include amyl bromide, isoamyl bromide, isobutylene bromide, ethylene bromide, diphenylmethyl bromide, benzal bromide, methylene bromide, tribromomethylphenyl sulfone, carbon tetrabromide, tris(2,3-dibromopropyl) phosphate, trichloroacetamide, amyl iodide, isobutyl iodide, 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane, hexachloroethane, triazine compounds, and the like.

[0035] The photopolymerizable resin composition may contain a radical polymerization inhibitor to improve thermal stability and storage stability. Examples of radical polymerization inhibitors include p-methoxyphenol, hydroquinone, pyrogallol, naphthylamine, tert-butylcatechol, cuprous chloride, 2,6-di-tert-butyl-p-cresol, 2,2'-methylenebis(4-methyl-6-tert-butylphenol), 2,2'-methylenebis(4-ethyl-6-tert-butylphenol), nitrosophenylhydroxyamine aluminum salt, diphenylnitrosamine, and the like.

[0036] The thickness of the photopolymerizable resin layer is preferably 3 μm or more and 100 μm or less, and more preferably 3 μm or more and 50 μm or less. The thinner the thickness of the photopolymerizable resin layer, the higher the resolution, and the thicker the thickness of the photopolymerizable resin layer, the higher the strength of the photopolymerizable resin layer.

[0037] The photopolymerizable resin layer is exposed to actinic light through a mask having a pattern of openings of a predetermined shape.

[0038] After exposure, the unexposed portion of the photopolymerizable resin layer is developed and removed using an alkaline aqueous solution developer. Thereby, a resist pattern is obtained. As the alkaline aqueous solution, an aqueous solution of sodium carbonate, potassium carbonate, etc. is used. The alkaline aqueous solution is selected according to the characteristics of the photopolymerizable resin layer.

[0039] "Etching process" The etchant is not particularly limited, but for example, an aqueous solution of ferric chloride, an aqueous solution of copper chloride, an aqueous solution of ammonium persulfate, etc. are used.

[0040] Through the surface of the resist pattern, the substrate is etched at a temperature of 60 °C and a redox potential of 600 mV using an aqueous solution of ferric chloride 44.8 °Be' as the etchant.

[0041] "Stripping process" Generally, an acidic stripping solution or an alkaline stripping solution is used as the resist stripping solution. Examples of the acidic stripping solution include arylsulfonic acids such as benzenesulfonic acid, toluenesulfonic acid, and xylenesulfonic acid, phenols, a stripping solution composed of a chlorine-based organic solvent, a stripping solution composed of aromatic hydrocarbons such as naphthalene, phenols, and arylsulfonic acids, etc. Examples of the alkaline stripping solution include an aqueous solution of sodium hydroxide, an ethylene oxide adduct of alkanolamine or polyalkylamine, a stripping solution composed of a sulfone compound and a glycol monoalkyl ether, a stripping solution mainly composed of dimethyl sulfoxide and composed of diethylene glycol monoalkyl ether and a nitrogen-containing organic hydroxy compound, etc.

[0042] In the stripping process, the substrate (with a photopolymerizable resin layer) after the etching is completed is immersed in a resist stripping solution of 1% by mass or more and 5% by mass or less of an aqueous solution of sodium hydroxide, and held at 40 °C to 70 °C for 30 seconds to 2 minutes. Thereby, the photopolymerizable resin layer is peeled off from the substrate.

[0043] "Acid treatment process" As the acid, sulfuric acid, hydrochloric acid, nitric acid, etc. are used. The concentration of the acid is preferably 10% by mass or more and 25% by mass or less, and more preferably 15% by mass or more and 20% by mass or less. When the concentration of the acid is 10% by mass or more, unevenness generation in the plating process, which is a subsequent process, due to the amount of the triazole-based compound remaining on the surface of the substrate to which the dry film resist was adhered, is suppressed. When the concentration of the acid is 25% by mass or less, the amount of the triazole-based compound remaining on the surface of the substrate to which the dry film resist was adhered retains its original corrosion prevention function, the surface of the substrate is less likely to be oxidized, and unevenness generation in the plating process, which is a subsequent process, is suppressed.

[0044] In the acid treatment step, it is preferable to immerse the substrate from which the photopolymerizable resin layer has been peeled off in the acid and hold it at 25°C or higher and 30°C or lower. The time for holding at the above temperature is preferably 10 seconds or more and 20 seconds or less. Thereby, the residual amount of the triazole-based compound remaining on the surface of the substrate is reduced.

[0045] Here, a method for measuring the mass of copper and the mass of the triazole-based compound in the 1-nm surface layer in the depth direction from the outermost surface of the substrate (copper or copper alloy) by TOF-SIMS will be described. The measurement conditions for the mass of copper and the mass of the triazole-based compound using TOF-SIMS are, for example, an acceleration voltage of 25 kV, a primary ion species of Bi3 +++ , a secondary ion polarity of positive and negative, and an analysis area of 500 μm × 500 μm.

[0046] "Underlayer treatment step" In the underlayer treatment step, nickel plating is performed. In the present embodiment, as the underlayer treatment for gold plating, as nickel plating, electroless nickel plating or electroless nickel alloy plating is applied. In electroless nickel plating or electroless nickel alloy plating, the substrate is immersed in an electroless nickel plating bath or an electroless nickel alloy plating bath, and an electroless nickel plating film or an electroless nickel alloy plating film can be formed on the surface of the substrate. The composition of the electroless nickel plating solution or electroless nickel alloy plating solution is not particularly limited, and known plating solutions can be used. Electroless nickel plating is substantially nickel-phosphorus plating or nickel-boron plating. Nickel alloy plating includes, for example, nickel-cobalt plating, nickel-tin plating, nickel-tin-zinc plating, nickel-tungsten-phosphorus plating, etc. Known electroless nickel plating solutions basically contain soluble nickel salts and reducing agents as main components, and various additives such as complexing agents, pH adjusters, and reaction accelerators. In electroless nickel plating, when a phosphorus-based reducing agent (for example, hypophosphite) is used, a nickel-phosphorus plating film can be obtained, and when a boron-based reducing agent (for example, dimethylamine borane) is used, a nickel-boron film can be obtained.

[0047] The temperature of the plating bath is preferably 15°C or higher and 100°C or lower, and more preferably 20°C or higher and 90°C or lower. The time for immersing the substrate in the plating bath is preferably 5 minutes or more and 1 hour or less, and more preferably 10 minutes or more and 30 minutes or less. As the stirring method of the plating bath, air stirring, rapid liquid flow stirring, mechanical stirring by stirring blades, etc. are used.

[0048] "Plating process" The etched product obtained by the method for manufacturing an etched product of the present embodiment is subjected to a plating process. When the etched product is used as a printed wiring board, an IC lead frame, or a spring for a camera module, since it has excellent conductivity, gold plating is preferably used as the plating process.

[0049] The gold plating is not particularly limited, and examples thereof include methods for forming a replacement gold plating film, a replacement reduction gold plating film, a reduction gold plating film, an electrolytic gold plating film, etc. In replacement gold plating, replacement reduction gold plating, and reduction gold plating, the substrate can be immersed in an electroless gold plating bath to form an electroless gold plating film on the surface of the substrate. In the case of electrolytic gold plating, an electrolytic gold plating film can be formed by applying an electric current to the substrate.

[0050] The temperature of the plating bath is preferably 15°C or higher and 100°C or lower, and more preferably 20°C or higher and 90°C or lower. The time for immersing the substrate in the plating bath is preferably 5 minutes or longer and 1 hour or shorter, and more preferably 10 minutes or longer and 30 minutes or shorter. As the stirring method of the plating bath, air stirring, rapid liquid flow stirring, mechanical stirring by a stirring blade, etc. are used.

[0051] According to the method for manufacturing an etched product of the present embodiment, it is possible to provide an etched product in which no appearance defect occurs even when plating treatment is performed.

Examples

[0052] Hereinafter, the present invention will be described more specifically with reference to experimental examples, but the present invention is not limited to the following experimental examples.

[0053] [Production of Etched Product] The photocurable resin composition having the following composition was sufficiently stirred and mixed, and using a bar coater, the obtained mixture was uniformly applied onto the surface of a polyethylene terephthalate film having a thickness of 20 μm as a support layer, and dried in a dryer at 95°C for 4 minutes to form a photocurable resin layer. The thickness of the photocurable resin layer was 40 μm. Next, a polyethylene film having a thickness of 30 μm was laminated on the photocurable resin layer side of the laminate composed of the photocurable resin layer and the polyethylene terephthalate film to obtain a dry film resist.

[0054] As the photocurable resin composition, one having the following composition was used. (1) A 25% methyl ethyl ketone solution of a copolymer having a composition of methyl methacrylate / methacrylic acid / n-butyl acrylate (mass ratio 65 / 25 / 10), an acid equivalent of 344, and a weight average molecular weight of 200,000: 25.5 parts by mass of solid content (2) A 35% methyl ethyl ketone solution of a copolymer having a composition of methyl methacrylate / methacrylic acid / styrene (mass ratio 50 / 25 / 25), an acid equivalent of 344, and a weight average molecular weight of 50,000: 24 parts by mass of solid content (3) Phenoxyhexaethylene glycol acrylate: 9 parts by mass (4) Polypropylene glycol #400 dimethacrylate: 11 parts by mass (5) Dimethacrylate of glycol obtained by adding an average of 3 moles of ethylene oxide to both ends of polypropylene glycol to which an average of 10 moles of propylene oxide has been added: 21 parts by mass (6) 4,4'-Bis(diethylamino)benzophenone: 0.2 parts by mass (7) 2-(O-Chlorophenyl)-4,5-diphenylimidazolyl dimer: 3.5 parts by mass (8) Oxyethylene(6)oxypropylene(2)nonyl ether (random structure): 5 parts by mass (9) Malachite green: 0.05 parts by mass (10) Leuco crystal violet: 0.5 parts by mass (11) 1,2,3-Benzotriazole: 0.07 parts by mass

[0055] Next, the polyethylene film was peeled off from the dry film resist and transferred onto the surface of the copper substrate. Next, a patterned exposure mask was overlaid on the polyethylene terephthalate film and exposed to ultraviolet light to cure the photocurable resin layer and form a resist pattern. Thereafter, the uncured photocurable resin layer was dissolved and removed with a 1% by mass aqueous sodium carbonate solution to obtain a resist pattern on the surface of the copper substrate.

[0056] Next, through the resist pattern, the copper substrate was etched with an aqueous ferric chloride solution at a temperature of 60°C and a redox potential of 600 mV.

[0057] Next, the resist pattern was peeled off from the copper substrate by holding it in a 3 mass% aqueous sodium hydroxide solution at 50°C for 1 minute.

[0058] Next, the benzotriazole adhering to the surface of the etched copper substrate was removed using sulfuric acid under the conditions of Experimental Examples 1 to 10 shown in Table 1.

[0059] Next, by TOF-SIMS, the mass of copper and the mass of benzotriazole were measured in the surface layer with a depth of 1 nm from the outermost surface of the copper substrate. TOF-SIMS was analyzed under the following conditions. The results are shown in Table 1. In Table 1, the mass of benzotriazole is the mass of benzotriazole (negative secondary ion C6H4N + ) when the mass of copper (positive secondary ion Cu - ) is taken as 100. <Device Name> TOF-SIMS (manufactured by ION-TOF) <Analysis Conditions> Acceleration voltage: 25 kV Primary ion species: Bi3 +++ Secondary ion polarity: positive and negative Analysis area: 500 μm × 500 μm

[0060] Next, electroless nickel plating was performed on the copper substrate as a pretreatment. The following was used as the electroless nickel plating solution. [Electroless Nickel Plating Solution] Nickel sulfate hexahydrate (as Ni 2+ ) 0.1 mol / L Sodium hypophosphite monohydrate 30 g / L Succinic acid 25.0 g / L Balance pure water pH (20°C) 4.6 The temperature of the plating solution was set at 90 °C. The time for immersing the copper substrate in the plating solution was set at 20 minutes. The plating solution was stirred by a stirring blade. In this way, after forming a nickel-phosphorus film on the surface of the etched substrate, it was washed with pure water and dried.

[0061] For the 10 kinds of samples (Experimental Examples 1 to 10) on which nickel plating was completed, the appearance was evaluated visually. In the appearance evaluation, when there was no unevenness on the substrate surface, it was evaluated as "○", when there was partial unevenness on the substrate surface, it was evaluated as "△", and when there was overall unevenness on the substrate surface, it was evaluated as "×". The results are shown in Table 1.

[0062] Next, electrolytic gold plating was performed on the copper substrate on which nickel plating had been performed. The following was used as the electrolytic gold plating solution. [Electrolytic Gold Plating Solution] To 30 g of a solution in which 0.6 g of gold, 0.6 g of iodine, 5.1 g of potassium iodide, 18 g of ethylene glycol, and 5.7 g of water were mixed and dissolved, 22.8 g of ethylene glycol, 7.2 g of water, 0.48 g of tartaric acid, and 3.6 g of dipotassium phosphate were further added and stirred until dissolved. 0.0064 g of polyvinylpyrrolidone K85-95 (manufactured by ACROS, average weight molecular weight 1300000) was added and dissolved in this solution to prepare an electrolytic gold plating solution. The respective concentrations at the time of preparation in this electrolytic gold plating solution were 0.9 mass% of gold, 0.9 mass% of iodine, 8.0 mass% of potassium iodide, 63.7 mass% of ethylene glycol, and 20.1 mass% of water, and the content of iodine element in the gold plating solution was 7.0 mass%. The temperature of the electrolytic gold plating solution was set at 25 °C. The time for immersing the copper substrate on which nickel plating had been performed in the electrolytic gold plating solution was set at 30 minutes. The electrolytic gold plating solution was stirred by a stirring blade. Specifically, using the obtained electrolytic gold plating solution, with pure gold as the counter electrode (anode), electrolytic gold plating was performed on the nickel plating of the copper substrate at a current density of 5 mA / cm 2 for 30 minutes, and plating was performed at a voltage of about 0.20 V. In this way, after forming a gold film on the nickel-phosphorus film of the copper substrate, it was washed with pure water and dried.

[0063] For the 10 samples (Experimental Examples 1 to 10) on which gold plating was completed, the appearance was evaluated visually. In the appearance evaluation, when there was no unevenness on the substrate surface, it was evaluated as "○", when there was partial unevenness on the substrate surface, it was evaluated as "△", and when there was overall unevenness on the substrate surface, it was evaluated as "×". The results are shown in Table 1.

[0064]

Table 1

[0065] From the results shown in Table 1, in Experimental Examples 3 - 7, there were no appearance defects on the surface of nickel plating and the surface of gold plating. In Experimental Examples 1 and 2, the unevenness due to oxidation of the copper alloy surface affected the nickel plating, and unevenness occurred on the entire surface or partially on the surface of the nickel plating. In Experimental Examples 8 - 10, unevenness occurred on the entire surface or partially on the surface of the nickel plating due to benzotriazole remaining on the surface of the copper alloy.

Claims

1. An etched product to be subjected to plating, which is made of copper or a copper alloy, and in a surface layer having a depth of 1 nm from the outermost surface, when the mass of copper is 100, the mass of the triazole-based compound is 4 or more and 13 or less. The etched product.

2. The etched product according to claim 1, wherein the triazole-based compound is benzotriazole.

3. The etched product according to claim 1 or 2, wherein the plating is gold plating.

4. The etched product according to claim 3, wherein nickel plating is performed as a base treatment for the gold plating.

5. A method for manufacturing an etched product to be subjected to plating, which is made of copper or a copper alloy, and in a surface layer having a depth of 1 nm from the outermost surface, when the mass of copper is 100, the mass of the triazole-based compound is 4 or more and 13 or less. The method for manufacturing an etched product.

6. The method for manufacturing an etched product according to claim 5, wherein the triazole-based compound is benzotriazole.

7. The method for manufacturing an etched product according to claim 5 or 6, wherein the plating is gold plating.

8. The method for manufacturing an etched product according to claim 7, which includes a step of performing nickel plating as a base treatment for the gold plating.

9. The method for manufacturing an etched product according to claim 5, wherein the mass of the copper and the mass of the triazole-based compound are measured by time-of-flight secondary ion mass spectrometry.

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