Photosensitive conductive paste, cured product, fired body, electronic component, method for manufacturing insulating ceramic layer with circuit pattern, electronic component, method for manufacturing substrate with circuit pattern, and inductor

Abstract

Provided is a photosensitive conductive paste capable of forming a high-precision circuit pattern and having a small shrinkage amount during firing of the circuit pattern. The photosensitive conductive paste contains a conductive powder (A) and a photosensitive organic component (B), the median particle diameter r of the particle size distribution of the conductive powder (A) is 3.0 μm or more and 6.0 μm or less, and the content V1 of the conductive powder (A) in all solid components is 37 vol% or more and 55 vol% or less.

Description

TECHNICAL FIELD

[0001] The present application relates to a photosensitive conductive paste, a cured product, a fired body, an electronic component, a method for manufacturing an insulating ceramic layer with a circuit pattern, and a method for manufacturing an electronic component. BACKGROUND

[0002] In recent years, with the development of high speed, high frequency, and miniaturization of electronic components, there is a demand for forming a fine and low resistance circuit pattern on a substrate for mounting them. For example, a photosensitive conductive paste capable of forming a high-fineness circuit pattern on a green sheet, capable of suppressing firing defects has been proposed (for example, see Patent Literature 1).

[0003] PRIOR ART DOCUMENTS

[0004] PATENT LITERATURE

[0005] Patent Literature 1: International Publication No. 2019 / 202889 SUMMARY

[0006] PROBLEMS TO BE SOLVED BY THE INVENTION

[0007] As an example of a method for manufacturing an electronic component, there is a method in which a photosensitive conductive paste is used to form a circuit pattern on an insulating ceramic layer, and the resulting insulating ceramic layer with a circuit pattern is laminated and fired. However, in the case of using the photosensitive conductive paste described in Patent Literature 1, at the portion where a plurality of circuit patterns are laminated, the shrinkage amount is large, and the difference from the shrinkage amount of the insulating ceramic layer is large, so there is a problem that a bend is easily generated at the end of the electronic component, or a notch is easily generated, and delamination between layers occurs.

[0008] Therefore, an object of the present application is to provide a photosensitive conductive paste capable of forming a high-fineness circuit pattern, and having a small shrinkage amount at the time of firing of the circuit pattern.

[0009] MEANS FOR SOLVING THE PROBLEMS

[0010] That is, the present application is a photosensitive conductive paste containing conductive particles (A) and a photosensitive organic component (B), the median particle diameter r of the particle size distribution of the aforementioned conductive particles (A) is 3.0 μm or more and 6.0 μm or less, and the content V1 of the aforementioned conductive particles (A) in the total solid content is 37 vol% or more and 55 vol% or less.

[0011] In addition, the present application is a cured product obtained by curing the photosensitive conductive paste of the present application.

[0012] In addition, the present application is a fired body obtained by firing the photosensitive conductive paste of the present application.

[0013] Further, the present application is an electronic component including the sintered body of the present application and an insulating ceramic layer.

[0014] Further, the present application is a method for manufacturing an insulating ceramic layer with a circuit pattern, which includes: a step of applying the photosensitive conductive paste of the present application to an insulating ceramic layer to obtain an applied film; a step of drying the applied film to obtain a dried film; and a step of exposing and developing the dried film to obtain a circuit pattern.

[0015] Further, the present application is a method for manufacturing an electronic component, which includes: a step of repeating steps A to F sequentially a plurality of times on an insulating ceramic layer with a circuit pattern obtained by the method for manufacturing an insulating ceramic layer with a circuit pattern of the present application to obtain a laminate; and a step of sintering the laminate.

[0016] Step A: a step of applying a photosensitive insulating ceramic composition to obtain an applied film

[0017] Step B: a step of drying the applied film to obtain a dried film

[0018] Step C: a step of exposing and developing the dried film to obtain an insulating ceramic layer

[0019] Step D: a step of applying the photosensitive conductive paste of any one of claims 1 to 4 to the insulating ceramic layer to obtain an applied film

[0020] Step E: a step of drying the applied film to obtain a dried film

[0021] Step F: a step of exposing and developing the dried film to obtain a circuit pattern.

[0022] Further, the present application is a method for manufacturing a substrate with a circuit pattern, characterized by including:

[0023] a step of applying a photosensitive insulating ceramic composition to a substrate;

[0024] a step of exposing the applied film of the photosensitive insulating ceramic composition to a desired pattern;

[0025] a step of developing the applied film of the photosensitive insulating ceramic composition subjected to the exposure to form an insulating layer having a groove;

[0026] a step of applying the photosensitive conductive paste of the present application to the insulating layer and the groove;

[0027] a step of exposing the applied film of the photosensitive conductive paste in correspondence with the groove;

[0028] and developing the exposed film of the photosensitive conductive paste, thereby forming a circuit pattern at a position corresponding to the groove,

[0029] The groove has a tapered shape on the side surface.

[0030] In addition, the present application is a method for manufacturing an inductor, characterized by including the method for manufacturing a substrate with a circuit pattern of the present application in the process.

[0031] Effects of the Invention

[0032] The photosensitive conductive paste according to the present application can produce a circuit pattern with high fineness and small shrinkage at the time of firing. DETAILED DESCRIPTION

[0033] <Photosensitive conductive paste>

[0034] The photosensitive conductive paste of the present application contains conductive particles (A) and a photosensitive organic component (B).

[0035] <Conductive particles (A)>

[0036] The photosensitive conductive paste of the present application contains conductive particles (A). As the conductive particles (A), for example, there can be mentioned powders of metals such as silver, gold, copper, platinum, palladium, tin, nickel, aluminum, tungsten, molybdenum, ruthenium oxide, chromium, titanium, indium, alloys thereof, carbon powder, and the like. Two or more of them can be contained. Among the above, from the viewpoint of conductivity, silver, copper, and gold are preferred, and from the viewpoints of cost and stability, silver is more preferred.

[0037] It is important that the median particle diameter r of the particle size distribution of the conductive particles (A) is 3.0 μm or more and 6.0 μm or less. By making r 3.0 μm or more, preferably 3.5 μm or more, and more preferably 4.0 μm or more, the movement of the conductive particles (A) can be suppressed in the firing process, and the shrinkage at the time of firing can be reduced. In addition, the decrease in the light transmittance of the film in the exposure process can be suppressed, and the occurrence of peeling at the time of development and the like, which makes it difficult to form a fine pattern, can be suppressed. On the other hand, by making r 6.0 μm or less, preferably 5.5 μm or less, and more preferably 5.0 μm or less, the contact probability of the conductive powders with each other at the time of firing decreases, and the increase in the volume resistivity of the conductive pattern can be suppressed. In addition, the straightness of the wire end portion in the fine wire is improved, and the short circuit of the wires with each other can be suppressed.

[0038] In the present application, the median particle diameter can be measured using a particle size distribution measuring device (Microtrac HRA Model No. 9320-X100, manufactured by Nikkiso Co., Ltd.) by a laser light scattering method.

[0039] It is important that the content V1 of the electrically conductive particles (A) in the total solid content is 37 vol% or more and 55 vol% or less. By making V1 37 vol% or more, preferably 40 vol% or more, more preferably 42 vol% or more, the amount of the solid content that disappears at the time of firing can be suppressed to be small, and the shrinkage amount can be suppressed to be small. On the other hand, by making V1 55 vol% or less, preferably 52 vol% or less, more preferably 50 vol% or less, it is possible to prevent the case where the light transmittance of the coating film is decreased in the exposure process, and it is difficult to form a fine pattern.

[0040] The method for measuring the volume of the electrically conductive particles (A), the volume of the inorganic particles (C) other than the electrically conductive particles, and the volume of the solid content of the photosensitive organic component (B) in the present application is described below. First, the paste is filtered to separate into a mixture of the electrically conductive particles and the inorganic particles, and the solid content of the photosensitive organic component (B). The electrically conductive powder and the inorganic particles are fractionated, and the mass of each of the electrically conductive powder and the inorganic particles is measured. The organic component is dried at 100°C for 2 hours, and the mass after drying is measured. The volume can be calculated from the mass and the density of each component.

[0041] <Photosensitive Organic Component (B)>

[0042] The photosensitive conductive paste of the present application contains a photosensitive organic component (B). In the present application, the photosensitive organic component refers to a group of organic components that change in properties under light, or at least a part of the components that cause the change. That is, it is not necessary that all of the components that constitute the photosensitive organic component in the present application contribute to the photosensitivity.

[0043] The photosensitive organic component (B) can preferably use a component containing an alkali-soluble resin, a photopolymerization initiator, and a solvent. Here, the alkali-soluble resin refers to a resin having an alkali-soluble group. As the alkali-soluble group, for example, a carboxyl group, a phenolic hydroxyl group, a sulfonic acid group, a thiol group, and the like can be given. Among them, from the viewpoint of high solubility in an alkali developer, a carboxyl group is preferred.

[0044] As the alkali-soluble resin, an acrylic resin is preferred, and a copolymer of an acrylic monomer having a carbon-carbon double bond and another monomer is preferred.

[0045] As the acrylic monomer having a carbon-carbon double bond, for example, the following can be given:

[0046] An acrylic ester having a chain aliphatic hydrocarbon group having 1 to 18 carbon atoms such as methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, t-butyl acrylate, n-pentyl acrylate, isodecyl acrylate, isooctyl acrylate, 2-ethylhexyl acrylate, allyl acrylate, lauryl acrylate, and stearyl acrylate;

[0047] acrylic acid benzyl ester, acrylic acid phenyl ester, acrylic acid 1-naphthyl ester, acrylic acid 2-naphthyl ester, and the like having a cyclic aromatic hydrocarbon group having 6 to 10 carbon atoms;

[0048] cyclohexyl acrylate, dicyclopentyl acrylate, 4-tert-butylcyclohexyl acrylate, dicyclopentenyl acrylate, bicyclopentadienyl acrylate, isobornyl acrylate, 3,3,5-trimethylcyclohexyl acrylate, and the like having a cyclic aliphatic hydrocarbon group having 6 to 15 carbon atoms,

[0049] substances obtained by replacing these acrylates with methacrylates, and the like. Two or more of them can be used.

[0050] As the copolymerization component other than the acrylic monomer, for example, the following can be given:

[0051] styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, a-methylstyrene, chloromethylstyrene, hydroxymethylstyrene, and the like styrene;

[0052] acrylic acid, methacrylic acid, itaconic acid, crotonic acid, maleic acid, fumaric acid, vinylacetic acid, and the like unsaturated carboxylic acid, anhydride thereof, and the like.

[0053] Two or more of them can be used.

[0054] The acrylic resin preferably has a carbon-carbon double bond in the side chain or at the molecular terminal, and the curing reaction speed at the time of exposure can be increased. As the structure having a carbon-carbon double bond, for example, the following can be given: a vinyl group, an allyl group, an acrylic group, a methacrylic group, and the like. Two or more of them can be possessed.

[0055] As the method of introducing a carbon-carbon double bond into the acrylic resin, for example, the following can be given: a method in which a compound having a glycidyl group or an isocyanate group, and a carbon-carbon double bond, acryloyl chloride, methacryloyl chloride, allyl chloride, and the like are reacted with a mercapto group, an amino group, a hydroxyl group, a carboxyl group, and the like in the acrylic resin.

[0056] As the compound having a glycidyl group and a carbon-carbon double bond, for example, the following can be given: glycidyl methacrylate, glycidyl acrylate, allyl glycidyl ether, glycidyl ethyl acrylate, crotonoyl glycidyl ether, glycidyl crotonate, glycidyl isocrotonate, "Cyclomer" (registered trademark) M100, A200, and the like manufactured by Daicel Chemical Industries, Ltd. Two or more of them can be used.

[0057] As the compound having an isocyanate group and a carbon-carbon double bond, for example, acryloyl isocyanate, methacryloyl isocyanate, acryloyl ethyl isocyanate, methacryloyl ethyl isocyanate, and the like can be given. Two or more of them can be used.

[0058] The photopolymerization initiator refers to a compound that decomposes by absorbing light of short wavelength such as ultraviolet rays, or generates a radical by a hydrogen abstraction reaction.

[0059] As the photopolymerization initiator that decomposes by absorbing light such as ultraviolet rays, for example, 1,2-octanedione, benzophenone, methyl o-benzoylbenzoate, 4,4'-bis(dimethylamino)benzophenone, 4,4'-bis(diethylamino)benzophenone, 4-benzoyl-4'-methyldiphenyl ketone, dibenzyl ketone, 2,2'-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2-hydroxy-2-methylpropiophenone, Michler's ketone, 2-methyl-[4-(methylthio)phenyl]-2-morpholino-1-propanone, 4-azidobenzylidene acetophenone, 2,6-bis(p-azidobenzylidene)cyclohexanone, 6-bis(p-azidobenzylidene)-4-methylcyclohexanone, and the like alkyl phenone-based photopolymerization initiators; 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, and the like acylphosphine oxide-based photopolymerization initiators; oxime ester-based photopolymerization initiators of 1-[4-(phenylthio)-2-(O-benzoyl oxime)], 1-[9-ethyl-6-2(2-methylbenzoyl)-9H-carbazol-3-yl]ethanone 1-(O-acetyloxime), 1-phenyl-1,2-butanedione-2-(O-methoxycarbonyl)oxime, 1-phenyl-propanedione-2-(O-ethoxycarbonyl)oxime, 1-phenyl-propanedione-2-(O-benzoyl)oxime, 1,3-diphenyl-propanetone-2-(O-ethoxycarbonyl)oxime, 1-phenyl-3-ethoxy-propanetone-2-(O-benzoyl)oxime, and the like.

[0060] As the photopolymerization initiator that generates a radical by a hydrogen abstraction reaction, for example, benzophenone, anthraquinone, thioxanthone, methyl phenylglyoxylate, and the like can be given. Two or more of them can be contained.

[0061] The solvent makes the components constituting the photosensitive conductive paste wet or dissolved, and makes the coatability excellent.

[0062] As the solvent, for example, N,N-dimethylacetamide, N,N-dimethylformamide, N-methyl-2-pyrrolidone, dimethylimidazolidinone, dimethylsulfoxide, diethylene glycol monoethyl ether, dipropylene glycol methyl ether, dipropylene glycol n-propyl ether, dipropylene glycol n-butyl ether, tripropylene glycol methyl ether, tripropylene glycol n-butyl ether, diethylene glycol monoethyl ether acetate, dipropylene glycol methyl ether acetate, propylene glycol phenyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monobutyl ether, diethylene glycol monobutyl ether acetate, γ-butyrolactone, ethyl lactate, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, ethylene glycol mono-n-propyl ether, diacetone alcohol, tetrahydrofurfuryl alcohol, propylene glycol monomethyl ether acetate, and the like can be given. Two or more of them can be contained.

[0063] The photosensitive organic component (B) can contain a photosensitive monomer, a dispersant, a plasticizer, a leveling agent, a surfactant, a silane coupling agent, an antifoaming agent, a stabilizer, and the like, within a range not impairing the desired properties thereof.

[0064] <Inorganic particles (C) other than the electrically conductive particles (A)>

[0065] The photosensitive conductive paste of the present application preferably further contains inorganic particles (C) other than the electrically conductive particles (A). By containing the inorganic particles (C), sintering of the electrically conductive particles (A) to each other can be hindered, and the shrinkage amount at the firing of the photosensitive conductive paste can be effectively suppressed.

[0066] As the inorganic particles (C), at least one selected from the group consisting of titanium oxide, aluminum oxide, silicon dioxide, cordierite, mullite, spinel, barium titanate, and zirconium oxide is preferably contained. Among them, use of aluminum oxide, titanium oxide, and silicon dioxide is particularly preferable, and silicon dioxide is further preferable from the viewpoint of fine processability.

[0067] The median particle diameter of the particle size distribution of the aforementioned inorganic particles (C) is preferably 1 to 100 nm. By making the median particle diameter of the particle size distribution of the aforementioned inorganic particles (C) 1 nm or more, sintering of the electrically conductive particles to each other can be hindered, and the shrinkage amount can be further suppressed. On the other hand, by making the median particle diameter 100 nm or less, the resistance value of the circuit pattern obtained after firing can be reduced.

[0068] The volume ratio V2 of the aforementioned inorganic particles (C) with respect to 100 volume% of the aforementioned electrically conductive particles (A) is preferably 3 volume% or more and 10 volume% or less. By making V2 3 volume% or more, more preferably 3.5 volume% or more, and further preferably 4 volume% or more, movement of the electrically conductive particles at the time of firing can be hindered, and the shrinkage amount at the time of firing can be further suppressed. On the other hand, by making V2 10 volume% or less, more preferably 7 volume% or less, and further preferably 5.5 volume% or less, the resistance value of the circuit pattern obtained after firing can be reduced.

[0069] The product r x V1x V2 of the aforementioned r, V1, and V2 of the photosensitive conductive paste of the present application is preferably 500 or greater and 3300 or less. By making r x V1x V2 500 or greater, more preferably 600 or greater, and further preferably 700 or greater, the shrinkage amount at the time of firing can be further suppressed. On the other hand, by making r x V1x V2 3300 or less, more preferably 2500 or less, and further preferably 1500 or less, mismatching of the shrinkage rate with the dielectric layer due to too little shrinkage can be prevented, and the generation of voids between the dielectric and the electrode can be prevented.

[0070] Manufacture of photosensitive conductive paste

[0071] The photosensitive conductive paste of the present application can be obtained, for example, by dissolving and / or dispersing the conductive particles (A), the photosensitive organic component (B) other than the solvent, and preferably further dissolving and / or dispersing the inorganic particles (C) in the solvent. As a device for dissolving and / or dispersing, for example, a three-roll mill, a disperser such as a ball mill, and a kneader can be mentioned.

[0072] Cured product

[0073] Next, the cured product will be described. The cured product of the present application is obtained by curing the photosensitive conductive paste of the present application.

[0074] The shape of the cured product of the present application is not particularly limited.

[0075] From the viewpoint of conductivity, the film thickness t of the cured product of the present application is preferably 5 μm or greater, and more preferably 10 μm or greater. On the other hand, from the viewpoint of fine pattern formability in a small area, it is preferably 35 μm or less, more preferably 30 μm or less, and further preferably 20 μm or less.

[0076] The cured product can have a prescribed pattern shape. As the pattern shape, for example, a stripe shape, a spiral shape, and the like can be mentioned.

[0077] The ratio t / w of the film thickness t to the line width w of the cured product is preferably 0.5 or greater and 1.0 or less. By making t / w 0.5 or greater and 1.0 or less, a wiring with a high aspect ratio can be obtained, and both fine wiring and low resistance can be achieved.

[0078] In addition, the ratio b / a of the bottom width b to the top width a of the cured product is preferably 0.6 or greater and 1.0 or less. By making b / a 0.6 or greater and 1.0 or less, a wiring with a large cross-sectional area and low resistance can be obtained.

[0079] The cured product layers can also be stacked to form a stack. The number of layers is preferably 1 to 30. By making the number of layers 1 or more, the thickness of the prescribed pattern can be increased. On the other hand, by making the number of layers 30 or less, the influence of alignment deviation between layers can be reduced.

[0080] <Manufacture of Cured Product>

[0081] The cured product can be obtained, for example, by applying the photosensitive conductive paste of the present application to a substrate and drying, and photo-curing by exposure. In the case of manufacturing a cured product in a pattern shape, the pattern can be formed by developing after performing pattern exposure.

[0082] As the coating method in the coating step, for example, spin coating using a spin coater, spray coating, roll coating, screen printing, lithographic printing, gravure printing, letterpress printing, flexographic printing, methods using a doctor blade coater, die coater, calender coater, meniscus coater, or bar coater can be given. Among these, screen printing is preferred from the viewpoint of excellent surface planarity of the obtained coated film, and easy adjustment of the film thickness by selection of the screen.

[0083] As the drying method, for example, heating drying using a heating device such as an oven, hot plate, infrared ray, vacuum drying, or the like can be given. The heating temperature is preferably 40 to 130°C. By making the drying temperature 40°C or higher, the solvent can be efficiently removed. On the other hand, by making the drying temperature 130°C or lower, thermal crosslinking of the photosensitive conductive paste can be suppressed, and the residue of the non-exposed portion in the exposure and development step described later can be reduced, and a more highly fine pattern can be easily formed. The heating time is preferably 5 minutes to 1 hour.

[0084] As the exposure method, a method of performing exposure through a photomask, and a method of performing exposure without using a photomask can be given. As the exposure method without using a photomask, a method of performing full-area exposure, a method of direct drawing using laser light, or the like can be given. As the exposure device, for example, a step-and-repeat exposure machine, a proximity exposure machine, or the like can be given. As the active light for exposure, for example, near-ultraviolet rays, ultraviolet rays, electron beams, X-rays, laser light, or the like can be given, and ultraviolet rays are preferred. As the light source of the ultraviolet rays, for example, a low-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a halogen lamp, a germicidal lamp, or the like can be given, and an ultra-high-pressure mercury lamp is preferred.

[0085] As the developer when performing alkali development, for example, an aqueous solution of tetramethylammonium hydroxide, diethanolamine, diethylaminoethanol, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, triethylamine, diethylamine, methylamine, dimethylamine, dimethylaminoethyl acetate, dimethylaminoethanol, dimethylaminoethyl methacrylate, cyclohexylamine, ethylenediamine, hexamethylenediamine, or the like can be given.

[0086] To the above aqueous solution, polar solvents such as N-methyl-2-pyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, γ-butyrolactone, and the like; alcohols such as methanol, ethanol, isopropanol, and the like; esters such as ethyl lactate, propylene glycol monomethyl ether acetate, and the like; ketones such as cyclopentanone, cyclohexanone, isobutyl ketone, methyl isobutyl ketone, and the like; surfactants; and the like can be added.

[0087] As the developing method, for example, a method in which a developer is sprayed to the dried film after exposure while the substrate on which the dried film is formed is left or rotated; a method in which the substrate on which the dried film after exposure is formed is immersed in a developer; a method in which the substrate on which the dried film after exposure is formed is immersed in a developer while ultrasonic waves are applied; and the like can be given.

[0088] A rinse treatment based on a rinse liquid can also be performed on the cured product obtained by development. As the rinse liquid, for example, water; an aqueous solution of an alcohol such as ethanol, isopropanol, and the like; an aqueous solution of an ester such as ethyl lactate, propylene glycol monomethyl ether acetate, and the like; and the like can be given.

[0089] <Calcined Body>

[0090] The calcined body of the present application is obtained by calcining the aforementioned photosensitive conductive paste of the present application.

[0091] As the calcining method, for example, a method in which heat treatment is performed at 300 to 600°C for 5 minutes to several hours, and further heat treatment is performed at 850 to 900°C for 5 minutes to several hours; and the like can be given.

[0092] <Electronic Component>

[0093] The electronic component of the present application contains the calcined body of the present application and an insulating ceramic layer. By having the insulating ceramic layer, unintended short-circuit between the calcined bodies can be suppressed.

[0094] As the composition of the insulating ceramic layer, in terms of oxides, SiO2 25 to 50 (mass%), Al2O3 30 to 60 (mass%), B2O3 5 to 20 (mass%), K2O 0.3 to 3 (mass%) is preferable. By being this composition, the relative dielectric constant ε described below is easily obtained.

[0095] The relative dielectric constant ε of the insulating ceramic layer is preferably 3.0 or more and 6.0 or less. By making ε 6.0 or less, when the insulating ceramic layer with a circuit pattern is applied to a multilayer chip inductor, an inductor with high performance and low loss can be obtained. Further, by making ε 3.0 or more, the mechanical strength can be improved.

[0096] The electronic component of the present application can have a terminal electrode outside the fired body and the insulating ceramic layer. As a material constituting the terminal electrode, for example, nickel, tin, and the like can be given.

[0097] <Method for manufacturing insulating ceramic layer with circuit pattern>

[0098] One of the methods for manufacturing an insulating ceramic layer with a circuit pattern of the present application includes: a coating step of coating the photosensitive conductive paste of the present application on an insulating ceramic layer to obtain a coated film; a step of drying the aforementioned coated film to obtain a dried film; and a step of exposing and developing the aforementioned dried film to obtain a circuit pattern.

[0099] First, the photosensitive conductive paste of the present application is coated on an insulating ceramic layer to obtain a coated film.

[0100] The insulating ceramic layer is obtained by coating an insulating ceramic composition or a photosensitive insulating ceramic composition on the entire surface or a part of an alumina, quartz glass, soda-lime glass, chemically strengthened glass, "Pyrex" (registered trademark) glass, synthetic quartz plate, epoxy resin substrate, polyetherimide resin substrate, polyether ketone resin substrate, polysulfone resin substrate, polyethylene terephthalate film (hereinafter, referred to as "PET film"), cyclic olefin polymer film, polyimide film, polyester film, aromatic polyamide film, and the like formed of resin, optical resin plate, and the like, and drying to obtain.

[0101] As the coating method, a screen printing method, a bar coater, a roll coater, a die coater, a doctor blade coater, and the like can be used.

[0102] In the case of using the photosensitive insulating ceramic composition, a photolithography method can be used for pattern formation.

[0103] The insulating ceramic composition preferably contains an insulating ceramic powder, a binder resin, and a solvent. As the insulating ceramic powder, for example, "Palceram" (registered trademark) BT149 (product name; manufactured by Nippon Chemical Industrial Co., Ltd.), L5 (product name; manufactured by Ferro corp.), SG-200 (product name; manufactured by Nippon Talc Co., Ltd.), and the like can be given. Two or more of them can be contained. As the binder resin, for example, an acrylic resin, a polyvinyl butyral resin, a polyvinyl alcohol resin, a cellulose resin, a methyl cellulose resin, and the like can be given. Two or more of them can be contained.

[0104] As the solvent of the insulating ceramic composition, the solvent contained in the aforementioned photosensitive organic component (B) of the photosensitive conductive paste can be appropriately used.

[0105] The photosensitive insulating ceramic composition preferably contains, in addition to the aforementioned insulating ceramic powder and solvent, an alkali-soluble resin and a photopolymerization initiator.

[0106] As the alkali-soluble resin and the photopolymerization initiator used in the photosensitive insulating ceramic composition, the alkali-soluble resin and the photopolymerization initiator contained in the aforementioned photosensitive organic component (B) of the photosensitive conductive paste can be suitably used.

[0107] As the coating step of coating the photosensitive conductive paste on the insulating ceramic layer to obtain a coated film, the methods exemplified as the coating method in the aforementioned method of producing a cured product can be cited.

[0108] Next, the aforementioned coated film is dried to obtain a dried film.

[0109] As the drying method in the drying step, the methods exemplified as the drying method in the aforementioned method of producing a cured product can be cited.

[0110] Next, the aforementioned dried film is subjected to exposure and development to obtain a circuit pattern.

[0111] As the exposure method in the exposure and development step, the methods exemplified as the exposure method in the aforementioned method of producing a cured product can be cited.

[0112] The dried film after exposure is subjected to development using a developing solution, and the non-exposed portion is dissolved and removed, whereby the desired pattern can be formed. As the developing solution, the developing solution exemplified as the aforementioned method of producing a cured product can be cited.

[0113] As the developing method, for example, the methods in which the insulating ceramic layer is allowed to stand or rotate while the developing solution is sprayed to the dried film after exposure, the method in which the insulating ceramic layer having the dried film after exposure is immersed in the developing solution, the method in which the insulating ceramic layer having the dried film after exposure is immersed in the developing solution while ultrasonic waves are applied, and the like can be cited.

[0114] The pattern obtained by development can be subjected to a rinsing treatment based on a rinsing solution. As the rinsing solution, the substances exemplified as the aforementioned rinsing solution in the method of producing a cured product can be cited.

[0115] The obtained insulating ceramic layer having a circuit pattern can also be laminated to produce a laminate.

[0116] The obtained insulating ceramic layer with a circuit pattern is preferably fired to produce a fired body. As the firing method, a method exemplified as the firing method in the production method of the fired body can be given. The circuit pattern formed on the insulating ceramic layer is a composite containing the electrically conductive powder (A) and the photosensitive organic component (B), and exhibits electrical conductivity by the electrically conductive powders (A) contacting each other at the time of firing.

[0117] <Method for manufacturing electronic component>

[0118] One of the methods for manufacturing an electronic component of the present application includes a step of obtaining a plurality of insulating ceramic layers with a circuit pattern by the production method of the insulating ceramic layer with a circuit pattern of the present application; a lamination step of laminating and thermocompressing the plurality of insulating ceramic layers with a circuit pattern to obtain a laminate; and a firing step of firing the laminate.

[0119] First, a plurality of insulating ceramic layers with a circuit pattern are obtained by the production method of the insulating ceramic layer with a circuit pattern of the present application.

[0120] Next, the plurality of insulating ceramic layers with a circuit pattern are laminated and thermocompressed to obtain a laminate. As the lamination method, for example, a method of stacking the insulating ceramic layers with a circuit pattern using a guide hole or the like can be given. As the thermocompression device, for example, an oil pressure press or the like can be given. The thermocompression temperature is preferably 90 to 130°C, and the thermocompression pressure is preferably 5 to 20 MPa.

[0121] Next, the laminate is fired. As the firing method, a method exemplified as the firing method in the production method of the fired body can be given.

[0122] One of the methods for manufacturing an electronic component of the present application includes a step of obtaining a plurality of insulating ceramic layers with a circuit pattern by the production method of the insulating ceramic layer with a circuit pattern of the present application; a lamination step of laminating and thermocompressing the plurality of insulating ceramic layers with a circuit pattern to obtain a laminate; and a firing step of firing the laminate.

[0123] Step A: a step of applying a photosensitive insulating ceramic composition to obtain an applied film

[0124] Step B: a step of drying the applied film to obtain a dried film

[0125] Step C: a step of exposing and developing the dried film to obtain an insulating ceramic layer

[0126] Step D: a step of applying the photosensitive conductive paste of the present application on the insulating ceramic layer to obtain an applied film

[0127] Process E: a process of drying the coating film to obtain a dried film

[0128] Process F: a process of exposing and developing the dried film to obtain a circuit pattern.

[0129] First, in Process A, a photosensitive insulating ceramic composition is coated on the insulating ceramic layer with a circuit pattern obtained by the production method of the insulating ceramic layer with a circuit pattern of the present application to obtain a coating film. As the photosensitive insulating ceramic composition, the photosensitive insulating ceramic composition in the production method of the insulating ceramic layer with a circuit pattern described above can be used. As the coating method, the methods exemplified as the coating method in the production method of the cured product described above can be cited.

[0130] Next, in Process B, the coating film of the photosensitive insulating ceramic composition obtained is dried to obtain a dried film. As the drying method, the methods exemplified as the drying method in the production method of the cured product described above can be cited.

[0131] Next, in Process C, the dried film obtained is exposed and developed to obtain an insulating ceramic layer. As the exposure method, the methods exemplified as the exposure method in the production method of the cured product described above can be cited. As the development method, the methods exemplified as the development method in the production method of the cured product described above can be cited.

[0132] Next, in Process D, the photosensitive conductive paste of the present application is coated on the insulating ceramic layer obtained to obtain a coating film.

[0133] Next, in Process E, the coating film of the photosensitive conductive paste obtained is dried to obtain a dried film.

[0134] Next, in Process F, the dried film obtained is exposed and developed to obtain a circuit pattern.

[0135] Next, the above Processes A to F are repeated sequentially a plurality of times to obtain a laminate.

[0136] Next, the laminate obtained is fired. As the firing method, the methods exemplified as the firing method in the production method of the fired body described above can be cited.

[0137] <Production method of a substrate with a circuit pattern>

[0138] The method for manufacturing the substrate with a circuit pattern of the present application preferably includes: a step of applying a photosensitive insulating ceramic composition to a substrate; a step of exposing the coating film of the photosensitive insulating ceramic composition to light into a desired pattern; a step of developing the coating film of the photosensitive insulating ceramic composition subjected to the exposure to form an insulating layer having a groove; a step of applying the photosensitive conductive paste of the present application to the insulating layer and the groove; a step of exposing the coating film of the photosensitive conductive paste to light in correspondence with the groove; and a step of developing the coating film of the photosensitive conductive paste subjected to the exposure to form a circuit pattern at a position corresponding to the groove, wherein the groove has a taper shape on the side surface.

[0139] By making the groove have a taper shape on the side surface, even in a paste containing a conductive powder having a large particle diameter, air bubbles are easily released when the photosensitive conductive paste is applied and filled in the groove, and a conductivity close to that expected by design can be obtained.

[0140] The ratio (d / c) of the top width (c) to the bottom width (d) of the groove having a taper shape is preferably 0.30 or more and less than 1.00. By making it less than 1.00, more preferably 0.95 or less, further preferably 0.90 or less, the filling property of the photosensitive conductive paste can be improved. In addition, by making it 0.3 or more, more preferably 0.5 or more, further preferably 0.7 or more, the cross-sectional area of the circuit pattern can be increased.

[0141] The viscosity of the photosensitive conductive paste is preferably 3 to 50 Pa-s. By making it 50 Pa-s or less, more preferably 40 Pa-s or less, further preferably 30 Pa-s or less, filling into the groove having a taper shape can be facilitated. In addition, by making it 3 Pa-s or more, more preferably 5 Pa-s or more, further preferably 10 Pa-s or more, application can be facilitated.

[0142] The viscosity of the photosensitive conductive paste is measured using a Brookfield-type viscometer under the conditions of 10 rpm.

[0143] The TI value (thixotropic index) of the photosensitive conductive paste is preferably 2.0 or less, more preferably 1.5 or less, further preferably 1.3 or less. By doing so, a photosensitive conductive paste having excellent leveling property and also excellent filling property into the groove can be produced.

[0144] The TI value of the photosensitive conductive paste is defined as the ratio (e / f) of the value (e) measured using a Brookfield-type viscometer under the conditions of 10 rpm to the value (f) measured under the conditions of 30 rpm.

[0145] The coating film obtained by applying the photosensitive conductive paste on the insulating layer and in the groove is exposed in correspondence with the groove. As the exposure method at this time, for example, there can be mentioned a proximity exposure in which exposure is performed through a mask, a method in which a pattern is directly drawn by laser, and the like.

[0146] As the opening width of the exposure mask at the time of exposure by the proximity exposure, it is preferable to be set to be equal to or smaller than the width (top width c) of the groove of the insulating layer. By doing so, a circuit pattern having a higher aspect ratio can be formed.

[0147] The manufacturing method of the substrate with a circuit pattern of the present application is suitable for the manufacture of an inductor. That is, the manufacturing method of the inductor of the present application includes the manufacturing method of the substrate with a circuit pattern of the present application in the process.

[0148] The substrate with a circuit pattern obtained by the manufacturing method of the present application is cut into a desired chip size, fired, coated with a terminal electrode, and subjected to plating treatment, whereby a multilayer chip inductor can be obtained. As the cutting device, for example, there can be mentioned a die cutter, a laser cutting machine, and the like.

[0149] By the firing, the conductivity of the circuit pattern can be exhibited, and a conductive pattern is made. As the coating method of the terminal electrode, for example, there can be mentioned a sputtering method and the like. As the metal used in the plating treatment, for example, there can be mentioned nickel, tin, and the like.

[0150] Example

[0151] Hereinafter, the present application will be explained in further detail by citing examples and comparative examples. However, the present application is not limited to the modes shown here.

[0152] [Measurement and evaluation method]

[0153] (1) Median particle diameter

[0154] The measurement was performed by using a particle size distribution measuring device (Microtrac" HRA Model No. 9320-X100 manufactured by Nikkiso Co., Ltd.) by a laser light scattering method.

[0155] (2) High-fineness pattern processing property

[0156] (Formation of insulating ceramic layer)

[0157] "Palceram" BT149 (manufactured by Nippon Chemical Industrial Co., Ltd.) as an insulating ceramic powder, 100 parts by volume, a polyvinyl butyral resin (SP value 19.1 (J / cm 3 ) 1 / 2)240 parts by volume of dibutyl phthalate as a plasticizer, 80 parts by volume of ethylene glycol monobutyl ether as a solvent, and 160 parts by volume of ethylene glycol monobutyl ether as a solvent were mixed, and the mixture was applied to an alumina substrate (100 mm x 100 mm x thickness 0.5 mm) by a doctor blade method to form an insulating ceramic layer.

[0158] (Formation of coated film)

[0159] The photosensitive conductive paste obtained in the Examples and Comparative Examples was applied to the aforementioned insulating ceramic layer by a screen printing method so that the dried film thickness became 10 μm to obtain a coated film.

[0160] (Formation of dried film)

[0161] The obtained coated film was dried using a hot air drier at 80°C for 10 minutes to form a dried film on the insulating ceramic layer. The same operation was repeated, and for each of the Examples and Comparative Examples, four substrates each having a dried film and an insulating ceramic layer formed thereon were prepared.

[0162] (Pattern formation)

[0163] On the aforementioned dried film, four kinds of exposure masks each having a line width / line space (hereinafter, referred to as "L / S") of 20 μm / 20 μm, 18 μm / 18 μm, 15 μm / 15 μm, and 12 μm / 12 μm of a coil-like pattern were each irradiated with an ultrahigh pressure mercury lamp having an output power of 21 mW / cm 2 for 400 mJ / cm 2 calculated as a wavelength of 365 nm) to form a latent image.

[0164] Then, a 0.1% by mass aqueous sodium carbonate solution was used as a developer, and spray development was performed until the time when all of the unexposed portions were dissolved (hereinafter, referred to as "total dissolution time") to produce four kinds of pattern formation sheets each having a different L / S.

[0165] For each of the aforementioned four kinds of pattern formation sheets, each was observed under an optical microscope at a magnification of 10 times, and according to the presence or absence of peeling or short circuit of the pattern, the following criteria were used for evaluation. D or more was regarded as acceptable.

[0166] A: In all of the four kinds of patterns, peeling and short circuit were not confirmed.

[0167] B: In patterns of 15 μm / 15 μm or more, peeling and short circuit were not confirmed, and in patterns of 12 μm / 12 μm or less, peeling or short circuit was confirmed.

[0168] C: In patterns of 18 μm / 18 μm or more, peeling and short circuit were not confirmed, and in patterns of 15 μm / 15 μm or less, peeling or short circuit was confirmed.

[0169] D: In the pattern of 20 μm / 20 μm or more, peeling and short-circuit were not confirmed, and in the pattern of 18 μm / 18 μm or less, peeling or short-circuit was confirmed.

[0170] E: In all of the above four kinds of patterns, peeling or short-circuit was confirmed.

[0171] (3) Volume resistivity

[0172] The photosensitive conductive paste obtained in each of the examples and comparative examples was applied on an alumina substrate (100 mm x 100 mm x thickness 0.5 mm) by a screen printing method so that the dried film thickness became 10 μm. The obtained applied film was dried for 10 minutes with a hot air drier at 80°C to obtain a dried film.

[0173] Exposure and development were carried out in the same manner as in the aforementioned "high-precision pattern processing property" except that an exposure mask of a prescribed pattern (length 5 cm x line width 1 mm, pattern with a 1 cm square pad at both ends) was used to obtain a pattern formation sheet for resistance measurement.

[0174] The obtained pattern formation sheet for resistance measurement was heat-treated at 880°C for 10 minutes to obtain a pattern formation fired body for resistance measurement.

[0175] The obtained pattern formation fired body for resistance measurement was subjected to magnified observation using an optical microscope at a magnification of 1000 times, and the line width of the fired body was measured, and the film thickness of the fired body was measured using a stylus profilometer ("SURFCOM" (registered trademark) 1400; Tokyo Precision Co., Ltd.). In addition, the resistance value of the above pattern formation fired body for resistance measurement was measured using a digital multimeter (CDM-16D; manufactured by CUSTOM Co.), and the volume resistivity was calculated according to the following formula.

[0176] Volume resistivity (μΩ-cm) = actual resistance value (Ω) x 10 6 x pattern line width (cm) x pattern thickness (cm) ÷ pattern length (cm) (Formula).

[0177] C or more was set as acceptable.

[0178] A: Volume resistivity was less than 2.2 μΩ-cm.

[0179] B: Volume resistivity was 2.2 μΩ-cm or more and less than 2.5 μΩ-cm.

[0180] C: Volume resistivity was 2.5 μΩ-cm or more and less than 3.0 μΩ-cm.

[0181] D: Volume resistivity was 3.0 μΩ-cm or more.

[0182] (4) Firing shrinkage

[0183] The photosensitive conductive paste obtained in each of the examples and comparative examples was applied to an alumina substrate (100 mm x 100 mm x thickness 0.5 mm) in a manner such that the dried film thickness became 10 μm by a screen printing method. The obtained applied film was dried for 10 minutes with a hot air drier at 80°C to obtain a dried film.

[0184] Exposure and development were performed using a mask having a coil-like pattern with an L / S of 20 μm / 20 μm, in the same manner as the "high-precision pattern processing property" described above, to obtain a pattern formation sheet for shrinkage measurement.

[0185] The pattern line width before firing was measured by using an optical microscope to perform magnified observation at a magnification of 1000 times, and the pattern film thickness before firing was measured by using a stylus profilometer ("SURFCOM" (registered trademark) 1400; Tokyo Precision Co., Ltd.).

[0186] Then, the pattern formation sheet for shrinkage measurement was heat-treated at 880°C for 10 minutes to perform firing, to obtain a pattern formation fired body for shrinkage measurement.

[0187] The pattern line width after firing was measured by using an optical microscope to perform magnified observation at a magnification of 1000 times, and the pattern film thickness after firing was measured by using a stylus profilometer ("SURFCOM" (registered trademark) 1400; Tokyo Precision Co., Ltd.). The firing shrinkage was calculated according to the following formula.

[0188] Line width change rate (%) = [pattern line width after firing (μm) / pattern line width before firing (μm)] x 100

[0189] Film thickness change rate (%) = [pattern film thickness after firing (μm) / pattern film thickness before firing (μm)] x 100

[0190] Firing shrinkage (%) = 100 - (line width change rate (%) x film thickness change rate (%)) / 100.

[0191] Evaluation was performed by the following criteria, with D or more being regarded as acceptable.

[0192] A: Firing shrinkage was less than 55.0%.

[0193] B: Firing shrinkage was 55.0% or more and less than 58.0%.

[0194] C: Firing shrinkage was 58.0% or more and less than 60.0%.

[0195] D: firing shrinkage is 60.0% or more and less than 63.0%.

[0196] E: firing shrinkage is 63.0% or more.

[0197] (5) Observation evaluation of cross section of circuit pattern

[0198] The cross section of the substrate with the circuit pattern obtained in Examples 16 to 20 and Comparative Examples 5 and 6 was cut in the line width direction of the circuit pattern. The cross section was observed at a magnification of 3000 times using a scanning electron microscope (S2400; manufactured by Hitachi, Ltd.) to observe the layer thickness of the insulating layer, the top width c, the bottom width d of the groove, and the gap between the circuit pattern and the insulating layer. The cross sections of the grooves at 10 different sites were observed, and the number of cross sections in which a gap of 5 μm or more was observed out of 10 was evaluated as a fraction, and 3 or less was set as acceptable. The size of the gap was calculated by measuring the longest part of the gap (the distance between the ends of the two most distant points in one gap).

[0199] (6) Evaluation of aspect ratio and resistance value of conductive pattern

[0200] A substrate was produced in the same manner as in Examples 16 to 20 and Comparative Examples 5 and 6, except that the length of the groove of the insulating layer and the circuit pattern was 40 mm. The substrate with the circuit pattern obtained was heat-treated at 880°C for 10 minutes to perform firing, and a conductive pattern was obtained. The resistance value of the conductive pattern was measured using a digital multimeter (CDM-16D; manufactured by CUSTOM). Subsequently, the conductive pattern was cut in the line width direction. The cross section thereof was observed at a magnification of 3000 times using a scanning electron microscope (S2400; manufactured by Hitachi, Ltd.), and the line width and the height of the conductive pattern were measured. The line width was set as the maximum width of the cross section of the conductive pattern. Based on the obtained results, the sheet resistance value and the aspect ratio of the conductive pattern were calculated. The sheet resistance value was calculated by the following formula.

[0201] Sheet resistance value (mΩ) = conductive pattern resistance value (mΩ) x line width (mm) ÷ conductive pattern length (mm)

[0202] Less than 3.5 mΩ was set as acceptable.

[0203] (Photoconductive conductive paste)

[0204] The raw materials used in the photoconductive conductive paste are described below.

[0205] Conductive particles (A)

[0206] A-1: Ag powder having a median particle diameter r of 3.2 μm and a density of 10.5 g / cm 3 ​

[0207] A-2: r is 4.5 μm, density is 10.5 g / cm 3 of Ag powder

[0208] A-3: r is 5.2 μm, density is 10.5 g / cm 3 of Ag powder

[0209] A-4: r is 5.8 μm, density is 10.5 g / cm 3 of Ag powder

[0210] A-5: r is 2.8 μm, density is 10.5 g / cm 3 of Ag powder

[0211] A-6: r is 6.5 μm, density is 10.5 g / cm 3 of Ag powder.

[0212] Alkali-soluble resin: an acrylic resin (weight average molecular weight 30,000, glass transition temperature 110°C, acid value 100 mgKOH / g, density 1.0 g / cm 3 ) obtained by addition reaction of 40 mol parts of glycidyl methacrylate with 100 mol parts of carboxyl groups of a copolymer of a molar ratio of methacrylic acid / methyl methacrylate / styrene of 54 / 23 / 23.

[0213] Photosensitive monomer: urethane acrylate containing an ester structure ( "NK OLIGO" UA-122P manufactured by Shin-Nakamura Chemical Co., Ltd., viscosity 7.0 Pa-s, weight average molecular weight 1,100, density 1.0 g / cm 3 ).

[0214] Photopolymerization initiator: oxime-based photopolymerization initiator ("ADEKA OPTOMER" N-1919 manufactured by ADEKA Corporation, density 1.3 g / cm 3 ).

[0215] Leveling agent: "DISPARLON" (registered trademark) L-1980N (density 1.0 g / cm 3 ; manufactured by Nippon Polyurethane Industry Co., Ltd.).

[0216] Dispersant: "FLOWLEN" G-700 (density 1.1 g / cm 3 ; manufactured by Kyoeisha Chemical Co., Ltd.).

[0217] Solvent: "CELTOL" CHXA (cyclohexanol acetate, density 1.0 g / cm 3 ; manufactured by Daicel Corporation).

[0218] Inorganic particles (C)

[0219] C-1: Silica (Nippon Aerosil (K.K.) "AEROSIL" R972, median particle diameter 12 nm, density 2.2 g / cm 3 )

[0220] C-2: Alumina (Nippon Aerosil (K.K.) "AEROXIDE" AluC, median particle diameter 13 nm, density 3.3 g / cm 3 ).

[0221] [Example 1]

[0222] A mixture of 5.0 g of alkali-soluble resin, 2.4 g of NK OLIGO UA-122P, 0.5 g of ADEKA OPTOMER N-1919, 0.1 g of "DISPARLON" L-1980N, 0.1 g of FLOWLEN G-700, and 11.9 g of "CELTOL" CHXA was prepared to obtain 20.0 g of photosensitive organic component B-1 (specific gravity 1.0 g / cm 3 ). The composition thereof is shown in Table 1.

[0223] The obtained 20.0 g of photosensitive organic component (B-1) was mixed with 51.8 g of Ag powder (A-3) and 0.5 g of inorganic particles (C-1), and kneaded using a three-roll mill to obtain the photosensitive conductive paste P-1 described in Table 2. The evaluation results are shown in Table 2.

[0224] [Examples 2 to 15, Comparative Examples 1 to 4]

[0225] The photosensitive conductive pastes P-2 to P-19 shown in Tables 2 to 4 were prepared by the same method as in Example 1.

[0226] Evaluation of high-fineness pattern processability:

[0227] In Example 4, peeling was confirmed only in the pattern of 12 μm / 12 μm.

[0228] In Example 5, peeling was confirmed only in the pattern of 15 μm / 15 μm or less.

[0229] In Example 6, short-circuiting was confirmed only in the pattern of 12 μm / 12 μm.

[0230] In Example 7, short-circuiting was confirmed only in the pattern of 15 μm / 15 μm or less.

[0231] In Example 8, peeling was confirmed only in the pattern of 15 μm / 15 μm or less.

[0232] In Example 13, peeling was confirmed only in the pattern of 15 μm / 15 μm or less.

[0233] In Example 14, peeling was confirmed only in the pattern of 15 μm / 15 μm or less.

[0234] In Example 15, peeling was confirmed only in the pattern of 18 μm / 18 μm or less.

[0235] In Comparative Example 2, peeling was confirmed in all of the four patterns.

[0236] In Comparative Example 3, peeling was confirmed only in the pattern of 18 μm / 18 μm or less.

[0237] In Comparative Example 4, short-circuiting was confirmed in all of the four patterns.

[0238] The evaluation results are shown in Tables 2 to 4.

[0239] [Examples 16 to 20, Comparative Examples 5, 6]

[0240] (Substrate)

[0241] As the substrate, an alumina plate was used.

[0242] (Photoconductive insulating composition)

[0243] An insulating ceramic powder (L5 manufactured by Ferro corp.) 55 parts by mass, an acrylic resin (weight average molecular weight 30,000, glass transition temperature 110°C, acid value 100 mgKOH / g) obtained by addition reaction of 100 mole parts of carboxyl of a copolymer of 40 mole parts of glycidyl methacrylate and a molar ratio of methacrylic acid / methyl methacrylate / styrene of 54 / 23 / 23 as an alkali-soluble resin, a photopolymerization initiator ("ADEKA OPTOMER" N-1919 manufactured by ADEKA Corporation) 7.0 parts by mass, a leveling agent ("FLOWLEN" G-700 manufactured by Kyoei Chemical Industry Co., Ltd.) 1.0 part by mass, a dispersant ("FLOWLEN" G-700 manufactured by Kyoei Chemical Industry Co., Ltd.) 1.0 part by mass, dibutyl phthalate as a plasticizer 4.0 parts by mass, a solvent ("CELTOL" CHXA manufactured by Daicel Corporation) 12.0 parts by mass were weighed, and then mixed, and kneaded by a three-roll mill to obtain a photoconductive insulating composition I-1.

[0244] (Photoconductive paste)

[0245] The photoconductive paste P-3 was used.

[0246] (Substrate with circuit pattern)

[0247] The photosensitive insulating composition I-1 was applied to a substrate in a layer thickness that became the insulating layer shown in Table 5, and dried.

[0248] Next, an exposure mask was disposed above the coating film of the photosensitive insulating composition in a gap shown in Table 5, and a full-line exposure was performed using an exposure device at an exposure amount shown in Table 5.

[0249] Next, the substrate was immersed in a 0.2 mass% Na2CO3 solution for a time shown in Table 5, thereby performing development.

[0250] Next, a rinsing treatment based on ultrapure water was performed.

[0251] Next, on the insulating layer having the groove, the photosensitive conductive paste was applied in a manner that became the maximum thickness of the coating film shown in Table 5 (the distance from the bottom of the groove of the insulating layer reached by the photosensitive conductive paste to the surface of the coating film of the photosensitive conductive paste. That is, approximately corresponding to the height of the circuit pattern) and dried.

[0252] Next, a mask having an opening width shown in Table 5 was disposed above the coating film of the photosensitive conductive composition, and exposure was performed on the portion corresponding to the groove of the insulating layer using an exposure device at an exposure amount of 400 mJ / cm 2 (converted at a wavelength of 365 nm).

[0253] Next, the substrate was immersed in a 0.2 mass% Na2CO3 solution for 30 seconds, thereby performing development.

[0254] Next, a rinsing treatment based on ultrapure water was performed, thereby obtaining a substrate with a circuit pattern.

[0255] [Table 1]

[0256]

[0257] [Table 2]

[0258]

[0259] [Table 3]

[0260]

[0261] [Table 4]

[0262]

[0263] [Table 5]

[0264]

Claims

1. A photosensitive conductive paste comprising conductive particles (A), a photosensitive organic component (B), and inorganic particles (C) other than the conductive particles (A), a median particle diameter r of a particle size distribution of the conductive particles (A) is 3.5 μm or more and 5.5 μm or less, a content V1 of the conductive particles (A) in the total solid components is 37 vol% or more and 55 vol% or less, a median particle diameter of a particle size distribution of the inorganic particles (C) is 1 to 100 nm, an amount V2 of the inorganic particles (C) with respect to 100 vol% of the conductive particles (A) is 3 vol% or more and 10 vol% or less, a product r x V1 x V2 of the r, V1, and V2 is 700 or more and 1500 or less.

2. The photosensitive conductive paste according to claim 1, wherein The inorganic particles (C) contain at least one selected from the group consisting of titanium oxide, aluminum oxide, silicon dioxide, cordierite, mullite, spinel, and barium titanate.

3. A cured product obtained by curing the photosensitive conductive paste according to claim 1 or 2.

4. The cured product according to claim 3, wherein a film thickness t is 10 μm or more and 35 μm or less.

5. The cured product according to claim 3 or 4, wherein a ratio t / w of the film thickness t to a line width w is 0.5 or more and 1.0 or less.

6. The cured product according to claim 3 or 4, wherein a ratio b / a of a bottom width b to a top width a is 0.6 or more and 1.0 or less.

7. A method for manufacturing an insulating ceramic layer with a circuit pattern, comprising: a step of applying the photosensitive conductive paste according to claim 1 or 2 on an insulating ceramic layer to obtain an applied film; a step of drying the applied film to obtain a dried film; and a step of exposing and developing the dried film to obtain a circuit pattern.

8. A method for manufacturing an electronic component, comprising: a step of obtaining a plurality of insulating ceramic layers with a circuit pattern by the method for manufacturing an insulating ceramic layer with a circuit pattern according to claim 7; a lamination step of laminating and thermally pressing the plurality of insulating ceramic layers with a circuit pattern to obtain a laminate; and a firing step of firing the laminate.

9. A method for manufacturing an electronic component, comprising: a step of obtaining a laminate by repeating sequentially a plurality of times Steps A to F on an insulating ceramic layer with a circuit pattern obtained by the method for manufacturing an insulating ceramic layer with a circuit pattern according to claim 7; and a step of firing the laminate, Step A: a step of applying a photosensitive insulating ceramic composition to obtain an applied film; Step B: a step of drying the applied film to obtain a dried film; Step C: a step of exposing and developing the dried film to obtain an insulating ceramic layer; Step D: a step of applying the photosensitive conductive paste according to claim 1 or 2 on the insulating ceramic layer to obtain an applied film; Step E: a step of drying the applied film to obtain a dried film; Step F: a step of exposing and developing the dried film to obtain a circuit pattern.

10. A method for manufacturing a substrate with an electric circuit pattern, characterized by, comprising: a step of applying a photosensitive insulating ceramic composition on a substrate; a step of exposing a coating film of the photosensitive insulating ceramic composition to a desired pattern; a step of exposing the coating film of the photosensitive conductive paste to light; a step of applying the photosensitive conductive paste of claim 1 or 2 on the insulating layer and in the groove; a step of exposing the coating film of the photosensitive conductive paste to light; and a step of developing the coating film of the photosensitive conductive paste exposed to light, thereby forming a circuit pattern at a position corresponding to the groove, wherein the groove has a tapered shape in a side surface.

11. The method for manufacturing a substrate with an electric circuit pattern according to claim 10, wherein, In the groove, a ratio d / c of a bottom width d to a top width c is 0.30 or more and less than 1.

00.

12. The method for manufacturing a substrate with an electric circuit pattern according to claim 10 or 11, wherein, The viscosity of the photosensitive conductive paste in the step of applying the photosensitive conductive paste on the insulating layer and in the groove is 3 to 50 Pa s.

13. The method for manufacturing a substrate with an electric circuit pattern according to claim 10 or 11, wherein, In the step of exposing the coating film of the photosensitive conductive paste to light, exposure is performed through an exposure mask having an opening width narrower than a top width A of the groove of the insulating layer.

14. A method of manufacturing an inductor, characterized by The manufacturing method of a substrate with a circuit pattern includes the steps described in claims 10 to 13.

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