TW202419966A - Method for producing ceramic green sheet with conductive pattern - Google Patents

Abstract

Provided is a method for producing a ceramic green sheet with a conductive pattern, the ceramic green sheet having a highly fine conductive pattern and the occurrence of disconnection therein being suppressed. This method for producing a ceramic green sheet with a conductive pattern involves the following steps in the stated order: a step (transferring step) for preparing a base material with a photosensitive layer, and transferring the photosensitive layer on a ceramic green sheet from above the base material, wherein the photosensitive layer contains (a) conductive particles, (b) non-conductive particles, (c) an alkali-soluble resin, (d) a photosensitizing agent, and (e) a solvent and is provided on the base material, and the content of the solvent (e) is 5.0% by mass or less; a step (exposing step A) for bringing the photosensitive layer into contact with an exposure mask and exposing same; and a step (developing step) for developing the photosensitive layer after exposure to form a conductive pattern.

Description

Method for producing ceramic green sheet with conductive pattern

The present invention relates to a method for manufacturing a ceramic green sheet with a conductive pattern.

In recent years, with the demand for miniaturization and higher performance of electronic components, internal wiring has been required to be more precise and have a higher aspect ratio. Inductors, which are one type of electronic components, have a coil-shaped internal electrode inside an insulator made of ceramic. Generally, they are made by laminating multiple layers of components in which the internal electrode is formed in a wound wire shape on a planar insulating layer made of ceramic. In order to achieve high precision of the inductor, it is effective to use a photosensitive conductive paste that can achieve the miniaturization of the internal electrode. As the photosensitive conductive paste, for example, a photosensitive paste comprising "an inorganic powder, an alkali-soluble resin having no photoreactive functional group and an acid value of 200 mgKOH/g to 300 mgKOH/g, a reactive compound, and a photoreaction initiator" has been proposed (for example, refer to Patent Document 1). [Prior Art Document] [Patent Document]

Patent document 1: Japanese Patent Publication No. 2019-215446

[The problem that the invention wants to solve]

As a method for manufacturing an inductor, for example, there are the following methods: forming internal electrodes on a ceramic green sheet and stacking them in multiple layers; or forming internal electrodes and ceramic green sheets alternately and repeatedly on a ceramic green sheet. Through research by the inventors and others, it is known that these methods have the following problems: if the photosensitive paste described in Patent Document 1 is directly applied to a ceramic green sheet and a pattern is formed, the line width at the bottom of the internal electrode in each layer becomes thinner, making it difficult to form high-precision internal wiring. The reason for this is believed to be that when a photosensitive paste film is formed on a ceramic green sheet, the solvent contained in the photosensitive paste dissolves the organic components contained in the ceramic green sheet, and the dissolved organic components are mixed into the photosensitive conductive paste. In addition, the surface of the photosensitive paste coating film is sticky due to residual solvent, so there is a problem that it cannot contact the exposure mask during exposure, making it difficult to form high-precision internal wiring. Furthermore, when the amount of solvent is large, it will corrode the surface of the ceramic green sheet, making it difficult to form internal electrodes, and there is a problem that wire breakage is easily caused by tiny defects. On the other hand, in order to suppress the influence of the solvent, it is considered to form a photosensitive paste coating on the ceramic green sheet and quickly dry it at a high temperature to remove the solvent. However, if the photosensitive paste coating is dried at a high temperature on the ceramic green sheet, the ceramic green sheet shrinks due to the heat, and there is a problem that it is difficult to form high-precision internal wiring.

Therefore, the object of the present invention is to provide a method for manufacturing a ceramic green sheet with a conductive pattern that suppresses the occurrence of disconnection and has a highly precise conductive pattern. [Means for Solving the Problem]

In order to solve the above-mentioned problems, the present invention mainly has the following structure. (1) A method for manufacturing a ceramic green sheet with a conductive pattern, which sequentially comprises: Preparing a substrate with a photosensitive layer having a photosensitive layer containing conductive particles (a), non-conductive particles (b), an alkali-soluble resin (c), a photosensitive agent (d) and a solvent (e), wherein the content of the solvent (e) is 5.0 mass % or less, and transferring the photosensitive layer from the substrate to the ceramic green sheet (transfer step); bringing an exposure mask into contact with the photosensitive layer to expose (exposure step A); and developing the exposed photosensitive layer to form a conductive pattern (development step). (2) A method for manufacturing a ceramic green sheet with a conductive pattern, comprising: Preparing a substrate with a photosensitive layer having a photosensitive layer containing conductive particles (a), non-conductive particles (b), an alkali-soluble resin (c), a photosensitive agent (d) and a solvent (e), wherein the content of the solvent (e) is 5.0 mass % or less, and laminating the substrate with the photosensitive layer on the ceramic green sheet in such a manner that the photosensitive layer is in contact with the ceramic green sheet (lamination step); Contacting an exposure mask with the substrate of the substrate with the photosensitive layer to expose the substrate (exposure step B); and Developing the exposed photosensitive layer to form a conductive pattern (development step). (3) A method for producing a ceramic green sheet with a conductive pattern as described in (1) or (2), wherein the content of the solvent (e) in the photosensitive layer is 0.1 mass % or more. (4) A method for producing a ceramic green sheet with a conductive pattern as described in any one of (1) to (3), wherein the alkali-soluble resin (c) comprises a carboxyl-containing resin having no unsaturated double bonds and has a glass transition temperature of 110°C or less. (5) A method for producing a ceramic green sheet with a conductive pattern as described in (4), wherein the glass transition temperature of the alkali-soluble resin (c) is 30°C or more and 70°C or less. (6) A method for producing a ceramic green sheet with a conductive pattern as described in any one of (1) to (5), wherein the photosensitive layer contains polyether-modified polydimethylsiloxane. (7) The method for producing a ceramic green sheet with a conductive pattern as described in any one of (1) to (6), further comprising: applying a photosensitive paste containing conductive particles (a), non-conductive particles (b), an alkali-soluble resin (c), a photosensitive agent (d) and a solvent (e) on a substrate by screen printing, and drying to form a photosensitive layer, thereby obtaining the substrate with the photosensitive layer. (8) The method for producing a ceramic green sheet with a conductive pattern as described in any one of (1) to (7), wherein the solvent (e) includes a solvent having a boiling point of 150°C to 300°C under atmospheric pressure. (9) A method for producing a ceramic green sheet with a conductive pattern as described in any one of (1) to (8), wherein the thickness of the photosensitive layer exceeds 10 μm and is 25 μm or less. (10) A method for producing a ceramic green sheet with a conductive pattern as described in any one of (1) to (9), wherein the ceramic green sheet contains a photosensitive organic component. (11) A method for manufacturing a laminated body, wherein a plurality of ceramic green sheets with conductive patterns are laminated, and the method comprises: a step of obtaining a ceramic green sheet with a conductive pattern by forming a first conductive pattern by the method for manufacturing a ceramic green sheet with a conductive pattern as described in any one of (1) to (10); a step of forming a ceramic green sheet on the conductive pattern side of the ceramic green sheet with the first conductive pattern; and a step of forming a second conductive pattern on the ceramic green sheet on which the ceramic green sheet with the first conductive pattern is formed by the method for manufacturing a ceramic green sheet with a conductive pattern as described in any one of (1) to (10). (12) A method for manufacturing a laminated body, which is a method for manufacturing a laminated body formed by stacking a plurality of ceramic green sheets with conductive patterns, and comprises: A step of obtaining a plurality of ceramic green sheets with conductive patterns by the method for manufacturing a ceramic green sheet with conductive patterns as described in any one of (1) to (10); and A step of stacking and hot-pressing the plurality of ceramic green sheets with conductive patterns. (13) A method for manufacturing a sintered body, which comprises: a step of obtaining a ceramic green sheet with conductive patterns by the method for manufacturing a ceramic green sheet with conductive patterns as described in any one of (1) to (10); and a step of sintering the obtained ceramic green sheet with conductive patterns. [Effect of the invention]

According to the present invention, a ceramic green sheet with a conductive pattern can be obtained which suppresses the occurrence of disconnection and has a high-precision conductive pattern.

The ceramic green sheet with a conductive pattern of the present invention has a ceramic green sheet and a conductive pattern on a substrate. For example, when used in an inductor, the ceramic green sheet forms an insulating layer and the conductive pattern forms an internal electrode by laminating and sintering the ceramic green sheet in multiple layers.

The method for producing a ceramic green sheet with a conductive pattern of the present invention sequentially comprises a transfer step or a lamination step, an exposure step, and a development step described below. The characteristic is that a photosensitive paste is not directly applied to the ceramic green sheet, but a photosensitive layer whose solvent amount is pre-set to a prescribed range is laminated on the ceramic green sheet by a transfer step or a lamination step. In this way, the adhesion of the photosensitive layer or the thinning of the bottom of the conductive pattern caused by the solvent (e) is suppressed, a high-precision pattern can be formed, and line breakage can be suppressed. In addition, since high-temperature drying on the ceramic green sheet is not required, the shrinkage of the ceramic green sheet caused by heat can be suppressed, and a high-precision pattern can be formed.

The first form of the method for manufacturing a ceramic green sheet with a conductive pattern of the present invention sequentially comprises: Preparing a substrate with a photosensitive layer having a photosensitive layer containing conductive particles (a), non-conductive particles (b), an alkali-soluble resin (c), a photosensitive agent (d) and a solvent (e), wherein the content of the solvent (e) is 5.0 mass % or less, and transferring the photosensitive layer from the substrate to the ceramic green sheet (transfer step); The step of bringing an exposure mask into contact with the photosensitive layer to expose (exposure step A); and The step of developing the exposed photosensitive layer to form a conductive pattern (development step). In the transfer step, the photosensitive layer is transferred to the ceramic green sheet, exposing the photosensitive layer on the surface, and in the exposure step A, contact exposure can be performed to bring the photosensitive layer into contact with the exposure mask. Therefore, a more detailed pattern can be formed.

The second form of the method for manufacturing a ceramic green sheet with a conductive pattern of the present invention sequentially comprises: Preparing a substrate with a photosensitive layer having a photosensitive layer containing conductive particles (a), non-conductive particles (b), an alkali-soluble resin (c), a photosensitive agent (d) and a solvent (e), wherein the content of the solvent (e) is 5.0 mass % or less, and laminating the substrate with the photosensitive layer on the ceramic green sheet in such a manner that the photosensitive layer is in contact with the ceramic green sheet (lamination step); The step of bringing an exposure mask into contact with the substrate of the substrate with the photosensitive layer to expose (exposure step B); and The step of developing the exposed photosensitive layer to form a conductive pattern (development step). In the lamination step, since the substrate with the photosensitive layer is laminated on the ceramic green sheet, the substrate exists on the photosensitive layer, and the photosensitive layer is exposed through the substrate in the exposure step B. Since the photosensitive layer is protected by the substrate, the disconnection of the conductive pattern can be further suppressed.

The substrate with a photosensitive layer used in the present invention can be obtained, for example, by applying a photosensitive paste containing conductive particles (a), non-conductive particles (b), an alkali-soluble resin (c), a photosensitive agent (d) and a solvent (e) on the substrate by screen printing and drying the paste to form a photosensitive layer.

Substrate As the substrate, for example, metal substrates, glass substrates, plastic films, etc. can be cited. Among these, from the viewpoint of the releasability of the photosensitive layer or the light transmittance of the exposure light in the exposure step B used in the second form, a plastic film containing a resin such as polyethylene terephthalate (PET), cycloolefin polymer, polycarbonate, polyimide, polyarylamide, fluororesin, acrylic resin, polyurethane resin, etc. is preferred, and a film containing PET, cycloolefin polymer, and polycarbonate is more preferred. From the viewpoint of improving the releasability of the photosensitive layer, it is preferred to perform a mold release treatment using a silicone resin, a fluororesin, etc. on one or both sides of the plastic film.

From the viewpoint of handling properties, the thickness of the substrate is preferably 10 μm or more, more preferably 20 μm or more. On the other hand, from the viewpoint of the thickness of the substrate, the followability to the ceramic green sheet in the transfer step or the lamination step, and the reduction of the gap between the exposure mask and the photosensitive layer in the exposure step B used in the second form, it is preferably 200 μm or less, more preferably 100 μm or less, and further preferably 75 μm or less.

Conductive particles (a) The conductive particles (a) of the present invention refer to particles having a resistivity of 1.0×10 ^-4 Ω·m or less at 20°C, and have the function of imparting conductivity to a conductive pattern by sintering. Examples of conductive particles (a) include particles of metals such as silver, gold, copper, platinum, palladium, tin, nickel, aluminum, tungsten, molybdenum, ruthenium, chromium, titanium, and indium, or alloys thereof, carbon, titanium nitride, and the like. Two or more of these may be contained. Among these, from the viewpoint of conductivity, particles of silver, copper, and gold are preferred, and from the viewpoint of stability, particles of silver are more preferred.

From the viewpoint of improving conductivity, the median particle size (D50) of the conductive particles (a) is preferably 1 μm or more. On the other hand, from the viewpoint of improving the light transmittance of the exposure light and forming a finer pattern, the D50 of the conductive particles (a) is preferably 5 μm or less. The D50 of the conductive particles (a) can be measured by a laser scattering method using a particle size distribution measuring device (Microtrac HRA Model No. 9320-X100; manufactured by Nikkiso Co., Ltd.).

From the viewpoint of conductivity, the content of the conductive particles (a) in the photosensitive paste is preferably 60% by mass or more, more preferably 65% by mass or more, and further preferably 70% by mass or more. On the other hand, from the viewpoint of light transmittance of exposure light, the content of the conductive particles (a) is preferably 90% by mass or less, more preferably 85% by mass or less, and further preferably 80% by mass or less.

Non-conductive particles (b) Non-conductive particles (b) are particles having a resistivity of more than 1.0×10 ^-4 Ω·m at 20° C. or being insulating, and have a function of suppressing the shrinkage of the conductive pattern during calcination.

Examples of the non-conductive particles (b) include aluminum oxide (Al ₂ O ₃ ), zirconium oxide (ZrO ₂ ), magnesium oxide (MgO), curium oxide (BeO), mullite (3Al ₂ O ₃ ·2SiO ₂ ), cordierite (5SiO ₂ ·2Al ₂ O ₃ ·2MgO), spinel (MgO·Al ₂ O ₃ ), olivine (2MgO·SiO ₂ ), calcite (CaO·Al ₂ O ₃ ·2SiO ₂ ), barium feldspar (BaO·Al ₂ O ₃ ·2SiO ₂ ), silicon dioxide (SiO ₂ ), barium titanium oxide (BaTiO ₃ ), aluminum nitride (AlN), ferrite (garnet type: Y ₃ Fe5O ₁₂ system, spinel type: MeFe ₂ O ₄ series), glass particles containing "SiO ₂ , Al ₂ O ₃ , CaO, B ₂ O ₃ , MgO, TiO ₂ ", etc. Two or more of these may be contained. Among these, from the viewpoint of further suppressing sintering defects, particles of titanium dioxide, aluminum oxide, silicon dioxide, cordierite, mullite, spinel, barium titanate, and zirconium oxide are preferred, and silicon dioxide particles are more preferred.

From the viewpoint of suppressing the shrinkage of the conductive pattern during calcination, the D50 of the non-conductive particles (b) is preferably 5 μm or less, more preferably 0.1 μm or less, and even more preferably 0.05 μm or less. When the D50 of the non-conductive particles (b) is 0.1 μm or less, the non-conductive particles (b) can be added to water, ultrasonically treated for 300 seconds, and then obtained by a dynamic light scattering method using Nanotrac WaveII-UZ251 (manufactured by Microtrac BEL).

From the viewpoint of suppressing the shrinkage of the conductive pattern during firing, the content of the non-conductive particles (b) in the photosensitive paste is preferably 0.1 mass % or more, more preferably 0.2 mass % or more, and further preferably 0.4 mass % or more. On the other hand, from the viewpoint of conductivity, the content of the non-conductive particles (b) is preferably 10 mass % or less, more preferably 5 mass % or less, and further preferably 2 mass % or less.

Alkali-soluble resin (c) Alkali-soluble resin (c) refers to a resin having a carboxyl group and/or a hydroxyl group in the side chain, and is a binder resin for photosensitive pastes. It also has the function of forming a pattern by dissolving during development.

As the alkali-soluble resin (c), an acrylic resin is preferred, and a copolymer of an acrylic monomer having a carbon-carbon double bond and other monomers is preferred. Examples of acrylic monomers and other monomers having a carbon-carbon double bond include raw materials of acrylic resins listed as examples of alkali-soluble resins (b-1) in Japanese Patent Application Laid-Open No. 2019-215446.

The alkali-soluble resin (c) preferably has a carbon-carbon double bond in the side chain and/or at the molecular end, which can increase the curing reaction speed during exposure. Examples of structures having a carbon-carbon double bond include: vinyl, allyl, acrylic, methacrylic, etc. Two or more of these may be present. Examples of methods for introducing a carbon-carbon double bond into the alkali-soluble resin (c) include, for example, in the case of an acrylic resin, a method of reacting a compound having a glycidyl group or an isocyanate group and a carbon-carbon double bond, acryl chloride, methacrylic chloride, allyl chloride, etc., with a hydroxyl group, an amine group, a hydroxyl group, or a carboxyl group in the acrylic resin.

Examples of compounds having a glycidyl group and a carbon-carbon double bond include glycidyl methacrylate, glycidyl acrylate, allyl glycidyl ether, glycidyl ethyl acrylate, crotonyl glycidyl ether, glycidyl crotonate, glycidyl isocrotonate, "Cyclomer (registered trademark)" M100, A200 (both manufactured by Daicel Chemical Industries, Ltd.), etc. Examples of compounds having an isocyanate group and a carbon-carbon double bond include acryloyl isocyanate, methacryloyl isocyanate, acryloyl ethyl isocyanate, methacryloyl ethyl isocyanate, etc. Two or more of these may be used.

It is also preferable that the alkali-soluble resin (c) contains a carboxyl-containing resin having no unsaturated double bonds. Examples of the carboxyl-containing resin having no unsaturated double bonds include: solid JONCRYL 67 (glass transition temperature 73°C), JONCRYL 678 (glass transition temperature 85°C), JONCRYL 611 (glass transition temperature 50°C), JONCRYL 693 (glass transition temperature 84°C), JONCRYL 682 (glass transition temperature 85°C), JONCRYL 694 (glass transition temperature 84°C), JONCRYL 686 (glass transition temperature 85°C), JONCRYL 687 (glass transition temperature 85°C), JONCRYL 688 (glass transition temperature 85°C), JONCRYL 689 (glass transition temperature 84°C), JONCRYL 691 (glass transition temperature 84°C), JONCRYL 693 (glass transition temperature 84°C), JONCRYL 694 (glass transition temperature 84°C), JONCRYL 695 (glass transition temperature 84°C), JONCRYL 696 (glass transition temperature 84°C), JONCRYL 697 (glass transition temperature 84°C), JONCRYL 698 (glass transition temperature 84°C), JONCRYL 699 (glass transition temperature 84°C), JONCRYL 691 ...1 (glass transition temperature 84°C), JONCRY (glass transition temperature 56°C), JONCRYL 690 (glass transition temperature 102°C), JONCRYL 819 (glass transition temperature 57°C), JONCRYL JDX-C3000A (glass transition temperature 65°C), JONCRYL JDX-C3080 (glass transition temperature 134°C), JONCRYL 52J dissolved in alkaline water (glass transition temperature 56°C), JONCRYL PDX-6157 (glass transition temperature 84°C), JONCRYL 60J (glass transition temperature 85°C), JONCRYL 63J (glass transition temperature 73°C), JONCRYL 70J (glass transition temperature 102°C), JONCRYL JDX-6180 (glass transition temperature 134°C), JONCRYL HPD-196 (glass JONCRYL HPD-96J (glass transition temperature 85°C), JONCRYL PDX-6137A (glass transition temperature 102°C), JONCRYL 6610 (glass transition temperature 85°C), JONCRYL JDX-6500 (glass transition temperature 65°C), JONCRYL PDX-6102B (glass transition temperature 19°C), etc. Two or more of these may be used.

From the viewpoint of improving transferability, the glass transition temperature of the carboxyl group-containing resin having no unsaturated double bonds is preferably 110°C or lower, more preferably 30°C to 70°C.

From the viewpoint of photolithography processability, viscosity characteristics, etc., the content of the alkali-soluble resin (c) in the photosensitive paste is preferably 1 mass % to 10 mass %.

Photosensitive agent (d) As the photosensitive agent (d), there can be listed photopolymerization initiators, dissolution inhibitors, etc. From the viewpoint of forming a thicker film conductive pattern, photopolymerization initiators are preferred.

The photopolymerization initiator imparts photocurability by decomposing by absorbing short-wavelength light such as ultraviolet light, or by generating free radicals by dehydrogenation reaction, thereby enabling the formation of patterns by negative photolithography. Examples of photopolymerization initiators include those exemplified as photoreaction initiators (d) in Japanese Patent Publication No. 2019-215446. From the perspective of photocurability, oxime-based photopolymerization initiators are preferred.

The dissolution inhibitor can increase the solubility of the exposed part in the developer, and can form a pattern by positive photolithography. As the dissolution inhibitor, it is preferred to use a dissolution inhibitor that generates an acid by the exposure energy used in the exposure step described later. For example, diazodisulfonium compounds, triphenylphosphine compounds, quinonediazide compounds, etc. can be listed. As diazodisulfonium compounds, for example, bis(cyclohexylsulfonyl)diazomethane, bis(tert-butylsulfonyl)diazomethane, bis(4-methylphenylsulfonyl)diazomethane, etc. can be listed. Examples of triphenylcopperium compounds include diphenyl-4-methylphenylcopperium trifluoromethanesulfonate, diphenyl-2,4,6-trimethylphenylcopperium p-toluenesulfonate, and diphenyl(4-methoxyphenyl)copperium trifluoromethanesulfonate. Examples of quinonediazide compounds include compounds in which sulfonic acid of quinonediazide is ester-bonded to a polyhydroxy compound, compounds in which sulfonic acid of quinonediazide is sulfonamide-bonded to a polyamine compound, and compounds in which sulfonic ester of quinonediazide is bonded and/or sulfonamide-bonded to a polyhydroxypolyamine compound. Two or more of these compounds may be contained.

The content of the photosensitive agent (d) in the photosensitive paste is preferably 0.1 mass % to 2 mass %.

Solvent (e) The solvent (e) has the function of adjusting the viscosity of the photosensitive paste. From the perspective of improving the coating property when the photosensitive paste is continuously coated, improving the peeling property from the substrate, and improving the transfer property, the boiling point of the solvent (e) under atmospheric pressure is preferably 150°C or higher. On the other hand, from the perspective of drying removability, the boiling point of the solvent (e) under atmospheric pressure is preferably 300°C or lower. Examples of the solvent having a boiling point within the above range include ethylene glycol hexyl ether, ethylene glycol monobutyl ether acetate, diethylene glycol n-butyl ether, diethylene glycol ethyl ether, diethylene glycol diethyl ether, diethylene glycol butyl methyl ether, diethylene glycol methyl ether, diethylene glycol monoethyl ether, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether, diethylene glycol monomethyl ether, dipropylene glycol n-butyl ether, dipropylene glycol propyl ether, dipropylene glycol methyl-n-propyl ether, dipropylene glycol methyl ether, dipropylene glycol methyl ether acetate, dipropylene glycol monomethyl ether acetate. Ester, dimethyl imidazolidinone, dimethyl sulfoxide, triethylene glycol dimethyl ether, propylene glycol diacetate, 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate, 2,2,4-trimethyl-1,3-pentanediol diisobutyrate, diethylene glycol hexyl ether, diethylene glycol mono-2-ethylhexyl ether, diethylene glycol monohexyl ether, dipropylene glycol phenyl ether, tetraethylene glycol dimethyl ether, triethylene glycol butyl methyl ether, triethylene glycol monobutyl ether, tripropylene glycol butyl ether, tripropylene glycol monobutyl ether, diethylene glycol dibutyl ether, etc. Two or more of these may be contained.

From the viewpoint of paste viscosity, the content of the solvent (e) in the photosensitive paste is preferably 5 mass % to 40 mass %.

The photosensitive paste of the present invention preferably contains a leveling agent. The leveling agent has the effect of suppressing shrinkage when the photosensitive paste is applied on a substrate and improving the releasability of the photosensitive layer.

As the leveling agent, for example, there can be listed: anionic surfactants such as ammonium lauryl sulfate and triethanolamine polyoxyethylene alkyl ether sulfate, cationic surfactants such as stearylamine acetate and lauryl trimethyl ammonium chloride, amphoteric surfactants such as lauryl dimethylamine oxide and lauryl carboxymethyl hydroxyethyl imidazolium betaine, nonionic surfactants such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether and sorbitan monostearate, silicone surfactants with polydimethylsiloxane, polymethyl alkyl siloxane and the like as the main skeleton, fluorine surfactants, and acrylic surfactants. The polymethyl alkyl siloxane may be an aralkyl-modified polymethyl alkyl siloxane. Among them, silicone-based surfactants or acrylic-based surfactants with polydimethylsiloxane as the main skeleton are preferred. Furthermore, it is more preferred that the photosensitive layer of the present invention contains polyether-modified polydimethylsiloxane as the silicone-based surfactant with polydimethylsiloxane as the main skeleton.

The photosensitive paste of the present invention may also contain additives such as photopolymerizable compounds having unsaturated bonds, plasticizers, leveling agents, dispersants, surfactants, silane coupling agents, defoaming agents, pigments, dyes, etc., within the range that does not impair its desired properties.

The photosensitive paste of the present invention can be obtained, for example, by dissolving and/or dispersing the aforementioned components (a) to (d) and other additives as required in a solvent (e). As a dissolving and/or dispersing device, for example, a dispersing machine such as a three-roll mill or a ball mill or a kneading machine can be listed. The dissolving and/or dispersing can be performed at room temperature or heated.

Next, a photosensitive paste is applied onto the substrate and dried to form a photosensitive layer.

Examples of coating methods include spray coating, roll coating, screen printing, coating methods using a doctor blade coater, die coater, calender coater, meniscus coater, and rod coater. Among these, screen printing is preferred from the viewpoints of suitability for thick film coating and continuous productivity.

As the drying method, for example, there can be mentioned heat drying using a heating device such as an oven, a hot plate, infrared rays, or vacuum drying. The heating temperature is preferably 40°C to 100°C, and it is more preferred to select the conditions such as the heating device, the drying temperature, and the drying time so that the solvent (e) in the photosensitive layer is 5.0 mass % or less.

In the present invention, it is preferred that the content of the solvent (e) in the photosensitive layer is 5.0% by mass or less. As described above, by transferring or laminating the photosensitive layer on a ceramic green sheet, the adhesion of the photosensitive layer or the thinning of the bottom of the conductive pattern caused by the solvent (e) can be suppressed, and a high-precision pattern can be formed, thereby suppressing line breakage. In addition, since high-temperature drying on the ceramic green sheet is not required, the shrinkage of the ceramic green sheet caused by heat can be suppressed, thereby forming a high-precision pattern. If the content of the solvent (e) exceeds 5.0% by mass, it is sometimes difficult to form a high-precision pattern due to the adhesion of the photosensitive layer or the thinning of the bottom of the conductive pattern. In addition, line breakage is sometimes prone to occur. The content of the solvent (e) is preferably 2.0 mass % or less, which can further improve the line width uniformity. On the other hand, the content of the solvent (e) in the photosensitive layer is preferably 0.10 mass % or more, which can improve the releasability from the substrate and improve the transferability.

The thickness of the photosensitive layer in the substrate with a photosensitive layer is preferably more than 10 μm, which can suppress disconnection of the conductive pattern. On the other hand, the thickness of the photosensitive layer is preferably less than 25 μm, because in the exposure step described later, the exposure light can easily reach the deep part of the photosensitive layer, thereby forming a finer pattern.

Next, each step will be described by taking the first embodiment of the method for producing a ceramic green sheet with a conductive pattern of the present invention as an example.

(Transfer step) Prepare the substrate with the photosensitive layer, and transfer the photosensitive layer from the substrate to the ceramic green sheet. The photosensitive layer can be peeled off the substrate and laminated on the ceramic green sheet, or the substrate with the photosensitive layer can be laminated on the ceramic green sheet in a manner that the photosensitive layer is in contact with the ceramic green sheet and then the substrate is peeled off. In either method, it is preferred to transfer by pressing, and the transfer device may include, for example, a press or a roller press. The transfer temperature is preferably 20°C to 200°C. The transfer pressure is preferably 0.1 MPa to 2.0 MPa. The pressing time is preferably 10 seconds to 300 seconds. Examples of environments include: air, nitrogen, vacuum, etc.

Examples of ceramic green sheets include sheets containing an insulating composition of an inorganic powder such as glass, ceramic, or glass ceramic, and a binder resin. The ceramic green sheet also preferably contains a photosensitive organic component to impart photosensitivity. In the above case, the insulating composition preferably contains a photosensitive organic component. In addition, a sheet having an insulating composition may also be provided on a substrate such as a plastic film or an optical resin board exemplified as a substrate with a photosensitive layer. Ceramic green sheets can be obtained, for example, by coating an insulating composition in a paste state obtained by dispersing the inorganic powder in a binder resin on a substrate such as a plastic film or an optical resin board. As the coating method, for example, there can be cited the method exemplified as the coating method of the photosensitive paste, etc. When the ceramic green sheet has photosensitivity, a pattern can also be formed by photolithography.

Examples of the photosensitive organic component include the alkali-soluble resin (c) exemplified as the raw material of the conductive paste, the photosensitizer (d), or a photopolymerizable compound having an unsaturated bond.

(Exposure step A) Exposure is performed by bringing the exposure mask into contact with the photosensitive layer. By eliminating the gap between the exposure mask and the photosensitive layer, the diffusion of the exposure light caused by diffraction or the reflection of the exposure light between the surface of the photosensitive layer and the exposure mask, which causes the line to become thicker, can be suppressed, thereby forming a higher-precision pattern. In addition, the uniformity of the line width of the pattern is improved. As chemical radiation used in exposure, there can be listed: ultraviolet rays, visible light, electron rays, X-rays, etc. In the present invention, i-rays (wavelength 365 nm), h-rays (wavelength 405 nm), and g-rays (wavelength 436 nm) of mercury lamps are preferred.

(Development step) The exposed photosensitive layer is developed to form a conductive pattern.

As the developer, an alkaline developer is preferably used, and for example, the developer exemplified as a developer for alkaline development in Japanese Patent Application Laid-Open No. 2019-215446 can be cited.

As developing methods, for example, there can be listed: a method of spraying a developer while the ceramic green sheet having the exposed photosensitive layer is stationary, conveyed or rotated; a method of immersing the ceramic green sheet having the exposed photosensitive layer in the developer; a method of immersing the ceramic green sheet having the exposed photosensitive layer in the developer and applying ultrasonic waves, etc.

The pattern obtained by development may be subjected to rinsing treatment using a rinsing liquid. As the rinsing liquid, for example, the rinsing liquid exemplified as the rinsing liquid in Japanese Patent Laid-Open No. 2019-215446 can be cited.

Furthermore, if necessary, a step of drying the residual solvent or developer in the photosensitive layer (drying step) may be included. By removing the residual solvent or developer by drying, the shrinkage rate can be reduced when producing the calcined body described later. As the drying method, the methods exemplified as the drying method in the formation of the photosensitive layer can be listed.

Next, a second embodiment of the method for producing a ceramic green sheet with a conductive pattern according to the present invention will be described.

(Lamination step) Prepare the substrate with the photosensitive layer, and laminate the substrate with the photosensitive layer on the ceramic green sheet in such a way that the photosensitive layer is in contact with the ceramic green sheet. In the lamination step, there is no need to peel off the substrate with the photosensitive layer. The rest is the same as the (transfer step) in the first form.

(Exposure step B) The exposure mask is brought into contact with the substrate with the photosensitive layer for exposure. By bringing the exposure mask into contact with the substrate, the gap between the exposure mask and the photosensitive layer can be kept constant, thereby improving the uniformity of the pattern line width. In addition, since the exposure mask is not in direct contact with the photosensitive layer, the defects of the photosensitive layer can be suppressed, and the disconnection of the conductive pattern can be further suppressed. Except for peeling off the substrate after exposure, the rest is the same as (exposure step A) in the first form.

The (developing step) and (layering step) are the same as those of the first embodiment, and may further include a drying step.

The ceramic green sheet with a conductive pattern in the present invention can be stacked in multiple layers to be used as a laminate. By stacking, the thickness of the conductive pattern can be increased. The number of stacked layers is preferably 2 to 30 layers. By setting the number of stacked layers to 30 or less, the influence of misalignment between layers can be suppressed.

The first form of the method for manufacturing a laminate of the present invention preferably comprises: A step of obtaining a ceramic green sheet with a conductive pattern by forming a first conductive pattern by the method; A step of forming a ceramic green sheet on the conductive pattern side of the ceramic green sheet with the first conductive pattern; and A step of forming a second conductive pattern by the method on the ceramic green sheet on which the ceramic green sheet with the first conductive pattern is formed.

The second form of the manufacturing method of the laminate of the present invention preferably has: A step of obtaining a plurality of ceramic green sheets with conductive patterns by the method; and A step of laminating and hot pressing a plurality of ceramic green sheets with conductive patterns. As a lamination method, for example, a method of stacking ceramic green sheets using guide holes, etc. can be cited. As a hot pressing device, for example, a hydraulic press can be cited. The hot pressing temperature is preferably 90°C to 130°C, and the hot pressing pressure is preferably 5 MPa to 20 MPa.

The ceramic green sheet or laminate with a conductive pattern in the present invention can be calcined and used as a calcined body. From the viewpoint of suppressing line breakage during calcination, the thickness of the calcined body is preferably 2 μm or more. On the other hand, from the viewpoint of suppressing expansion during calcination, the thickness of the calcined body is preferably 20 μm. In addition, from the viewpoint of suppressing line breakage during calcination, the line width of the conductive pattern in the calcined body is preferably 5 μm or more. On the other hand, from the viewpoint of improving the aspect ratio, the line width of the conductive pattern in the calcined body is preferably 40 μm or less.

The method for manufacturing a calcined body of the present invention preferably comprises: A step of obtaining a ceramic green sheet with a conductive pattern or a laminate thereof by the manufacturing method, and a step of calcining the obtained ceramic green sheet with a conductive pattern or a laminate thereof. As a calcining method, for example, a method of heat treating at 300°C to 600°C for 5 minutes to several hours and then heat treating at 850°C to 900°C for 5 minutes to several hours can be cited.

As an example of the method for producing the sintered body of the present invention, a method for producing a multilayer chip inductor will be described below.

First, by the method for manufacturing a ceramic green sheet with a conductive pattern of the present invention, a first conductive pattern is formed to obtain a ceramic green sheet with a conductive pattern. Next, a ceramic green sheet is formed on the conductive pattern side of the ceramic green sheet with the first conductive pattern. Then, a through hole is formed on the formed ceramic green sheet, and a conductor is embedded in the through hole, thereby forming interlayer connection wiring. As a through hole forming method, for example, laser irradiation can be listed. In the case where the ceramic green sheet is photosensitivity, through exposure and development through a mask having a through hole shape can be performed, so that a through hole can be formed with high precision. As a method for forming interlayer connection wiring, for example, a method of embedding a conductive paste by screen printing and drying can be listed. As a conductive paste, for example, a paste containing copper, silver, and a silver-palladium alloy can be listed. Next, a second conductive pattern is formed on the ceramic green sheet with the conductive pattern by the manufacturing method of the present invention. By repeating these steps, a laminate can be obtained. Alternatively, a laminate can be obtained by preparing a plurality of ceramic green sheets with the conductive pattern of the present invention, laminating them, and hot pressing them.

The obtained multilayer body is cut into the required chip size, sintered, coated with terminal electrodes, and plated to obtain a multilayer chip inductor. As these methods, the method exemplified as a method for manufacturing a multilayer chip inductor in Japanese Patent Publication No. 2019-215446 can be cited. [Example]

The present invention is further described in detail below with reference to embodiments and comparative examples, but the present invention is not limited thereto.

The materials used in each of the Examples and Comparative Examples are as follows.

Conductive particles (a): Ag particles with a particle size (D50) of 2.1 μm and a resistivity of 1.6×10 ^-8 Ω·m (hereinafter referred to as Ag particles). The particle size (D50) of the conductive particles was measured by a laser light scattering method using a particle size distribution measuring device (Microtrac HRA Model No. 9320-X100; manufactured by Nikkiso Co., Ltd.).

Non-conductive particles (b): Particle size (D50) 12 nm, insulating silica powder "AEROSIL (registered trademark)" R972 (manufactured by AEROSIL (Japan) Co., Ltd.) (hereinafter referred to as AEROSIL R972). The particle size (D50) of the non-conductive particles was measured by the dynamic light scattering method using Nanotrac WaveII-UZ251 (manufactured by Microtrac BEL) after adding the non-conductive particles to water and subjecting it to ultrasonic treatment for 300 seconds.

Alkali soluble resin (c): c-1: By adding 40 moles of glycidyl methacrylate to 100 moles of carboxyl groups of a copolymer of methacrylic acid/methyl methacrylate/styrene = 54/23/23 (molar ratio), a carboxyl-containing acrylic copolymer (c-1) is obtained. (Has unsaturated double bonds, weight average molecular weight 30,000, glass transition temperature 110°C).

c-2: JONCRYL 690 (no unsaturated double bonds, average molecular weight 16,500, glass transition temperature 102°C; manufactured by BASF Japan).

c-3: JONCRYL 819 (no unsaturated double bonds, average molecular weight 14,500, glass transition temperature 57°C; manufactured by BASF Japan).

Photosensitive agent (d): Oxime-based photopolymerization initiator "Optomer (registered trademark)" N-1919 (manufactured by ADEKA Co., Ltd.) (hereinafter referred to as N-1919).

Solvent (e): e-1: Cyclohexanol acetate "CELTOL (registered trademark)" CHXA (produced by Daicel, boiling point under atmospheric pressure: 173°C).

e-2: Propylene glycol monomethyl ether acetate (boiling point at atmospheric pressure: 146°C).

Photosensitive monomer: Ester-structured urethane acrylate NK oligomer UA-122P (viscosity 7.0 Pa·s, weight average molecular weight 1,100, manufactured by Shin-Nakamura Chemical Industry Co., Ltd.) (hereinafter referred to as UA-122P).

Leveling agent: "Disparlon (registered trademark)" L-1980N (manufactured by Kusumoto Chemicals Co., Ltd.) (hereinafter referred to as L-1980N).

Dispersant: Flowlen G-700 (manufactured by Kyoeisha Chemical Co., Ltd.) (hereinafter referred to as G-700).

<Manufacturing of a substrate with a ceramic green sheet> 250 g of ceramic powder "Palceram (registered trademark)" BT149 (manufactured by Nippon Kagaku Kogyo Co., Ltd.), 240 g of the alkali-soluble resin (c), 80 g of dibutyl phthalate as a plasticizer, 30 g of "IRGACURE (registered trademark)" 651 (manufactured by BASF) as a photopolymerization initiator, and 160 g of ethylene glycol monobutyl ether as a solvent were weighed, mixed, and kneaded using a three-roll mill to obtain a composition.

The obtained composition was applied on a PET film having a thickness of 100 μm and dried to prepare a substrate with a ceramic green sheet.

The evaluation methods in each embodiment and comparative example are as follows.

<Thickness of photosensitive layer> The thickness of the photosensitive layer produced in each embodiment and comparative example was measured using a stylus-type step gauge ("SURFCOM (registered trademark)" 1400; (co., Ltd.) Tokyo Seimitsu Seisakusho).

<Solvent content in photosensitive layer> From the photosensitive layer substrate prepared in each embodiment and comparative example, only the photosensitive layer was peeled off and its weight was measured, and then the weight was measured again after heating at 100°C for 3 hours using a hot air oven. The weight change before and after heating was calculated, and the solvent content in the photosensitive layer was calculated from the ratio (%) relative to the weight of the photosensitive layer before heating. Solvent content [weight %] = {(weight of photosensitive layer before heating [g] - weight of photosensitive layer after heating [g]) ÷ (weight of photosensitive layer before heating) [g]} × 100.

<Transferability> In the transfer step or lamination step of each embodiment and comparative example, the transfer step and lamination step were performed under low temperature and low pressure conditions within the range of heat pressing temperature of 50°C to 130°C, heat pressing pressure of 0.1 MPa to 0.3 MPa, and heat pressing time of 30 s (fixed). After the substrate was peeled off from the photosensitive layer, the surface of the substrate was visually observed, and the condition in which no residual photosensitive layer was confirmed on the substrate was used as the evaluation of transferability.

<Fine pattern processing> For the ceramic green sheets with conductive patterns obtained by each embodiment and comparative example, the conductive pattern portion was observed using an optical microscope at a magnification of 1,000 times, and the minimum line width was set at which no disconnection or detachment was observed.

In addition, for the ceramic green sheet with a conductive pattern obtained by each embodiment and comparative example, the conductive pattern corresponding to the exposure mask opening width of 15 μm was cut along the line width direction, and the pattern cross-section was magnified and observed using a scanning electron microscope (S2400; manufactured by Hitachi, Ltd.) at a magnification of 3,000 times, and the width of the top and bottom of the conductive pattern were measured, and the difference between the top width and the bottom width was calculated.

<Line width uniformity> For the ceramic green sheets with conductive patterns for line width uniformity evaluation obtained by each embodiment and comparative example, the conductive patterns corresponding to the exposure mask opening width of 15 μm in each of the 25 blocks were magnified at a magnification of 1,000 times using an optical microscope, and the line widths of the upper part of the conductive patterns were measured, and the difference between the maximum and minimum values was calculated.

<Broken Wire Probability> 100 ceramic green sheets with conductive patterns obtained by each embodiment and comparative example for evaluating the broken wire probability were calcined at 880°C for 10 minutes to obtain calcined bodies. The resistance value of the obtained calcined bodies was measured using a digital multimeter (CDM-16D; manufactured by Toyo (CUSTOM) Co., Ltd., Japan), and the case where the resistance value could not be measured was considered as a broken wire. The ratio (%) of the number of samples with broken wires among the 100 calcined bodies was taken as the broken wire probability.

(Example 1) ＜Preparation of photosensitive paste＞ In a 200 mL clean bottle, 14.8 g of c-1, 2.0 g of N-1919, 60.0 g of e-1, 7.5 g of UA-122P, 0.4 g of L-1980N, and 0.4 g of G-700 were placed and mixed using a rotation-revolution vacuum mixer "Defoaming Mixer Taro (registered trademark)" ARE-310 (manufactured by THINKY Co., Ltd.) to obtain 85.1 g of a resin solution. The obtained resin solution was mixed with 248.1 g of Ag particles and 1.6 g of AEROSIL R972, and kneaded using a three-roll mill (EXAKT M-50; manufactured by EXAKT) to obtain 334.8 g of a photosensitive paste.

<Manufacturing of a substrate with a photosensitive layer> The photosensitive paste obtained by the above method was applied to a PET substrate with a thickness of 50 μm by screen printing, and dried at a temperature of 55°C for 15 minutes to form a photosensitive layer with a thickness of 11 μm, thereby obtaining a substrate with a photosensitive layer. The solvent (e) content of the photosensitive layer was 1.0 mass %.

<Transfer step> Next, the substrate with the ceramic green sheet and the substrate with the obtained photosensitive layer are placed facing each other in such a way that the photosensitive layer and the ceramic green sheet are in contact with each other, and the photosensitive layer is transferred to the ceramic green sheet using a press. The transfer conditions at this time are the conditions of hot pressing temperature: 100°C, hot pressing time: 30 seconds, and hot pressing pressure: 0.3 MPa.

<Exposure step A> An exposure mask was brought into contact with the exposed photosensitive layer, and full-line exposure was performed at 300 mJ/ ^cm2 at a wavelength of 365 nm using an exposure device (PEM-6M; manufactured by Union Optical Co., Ltd.). As an exposure mask, an exposure mask having fine lines with a scale of 1 μm in the range of an opening width of 5 μm to 40 μm was used. In addition, as a sample for evaluating line width uniformity, an exposure mask having fine lines of the above line width in 25 blocks, 5 blocks in each vertical and horizontal directions, was used. In addition, as a sample for evaluating the probability of line breakage, an exposure mask having an opening portion with an opening width (L) of 40 μm and a length of 4.0 cm, which had the shape shown in Figure 1, was used.

<Development Step> After immersing the substrate having the exposed photosensitive layer in a 0.2 mass % Na ₂ CO ₃ solution, it is rinsed with ultrapure water to obtain a ceramic green sheet substrate with a conductive pattern.

The results of the evaluation according to the above method are shown in Table 1.

(Example 2 to Example 3, Comparative Example 1) In the <Manufacturing of a substrate with a photosensitive layer>, the same process as in Example 1 was performed except that the drying conditions were changed as described in Table 1. As a result, the content of the solvent (e) in the photosensitive layer was as shown in Table 1. Using the obtained substrate with a photosensitive layer, a ceramic green sheet with a conductive pattern was obtained in the same manner as in Example 1. The results of the evaluation by the above method are shown in Table 1.

(Example 4 to Example 6, Comparative Example 2) Instead of the <transfer step>, a <lamination step> was performed without peeling off the substrate with the photosensitive layer substrate, and instead of the <exposure step A>, an <exposure step B> was performed in which the exposure mask was brought into contact with the substrate with the photosensitive layer substrate and the substrate was peeled off after exposure. Ceramic green sheets with conductive patterns were obtained in the same manner as in Examples 1 to 3 and Comparative Example 1. The results of the evaluation by the above method are shown in Table 1.

(Example 7 to Example 8) <Preparation of photosensitive paste> In a 200 mL clean bottle, 7.4 g of c-1, 7.4 g of c-2, 2.0 g of N-1919, 60.0 g of e-1, 7.5 g of UA-122P, 0.4 g of L-1980N, and 0.4 g of G-700 were placed and mixed using a rotation-revolution vacuum mixer "Defoaming Mixer Taro (registered trademark)" ARE-310 (manufactured by THINKY Co., Ltd.) to obtain 85.1 g of a resin solution. The obtained resin solution was mixed with 248.1 g of Ag particles and 1.6 g of AEROSIL R972, and kneaded using a three-roll mill (EXAKT M-50; manufactured by EXAKT) to obtain 334.8 g of a photosensitive paste.

In the process of <Manufacturing of a substrate with a photosensitive layer>, the same process as in Example 1 was carried out except that the drying conditions were changed as shown in Table 1. As a result, the content of the solvent (e) in the photosensitive layer was as shown in Table 1. Using the obtained substrate with a photosensitive layer, a ceramic green sheet with a conductive pattern was obtained in the same manner as in Example 1. The results of the evaluation by the above method are shown in Table 1.

(Example 9-Example 10) <Preparation of photosensitive paste> In a 200 mL clean bottle, 7.4 g of c-1, 7.4 g of c-3, 2.0 g of N-1919, 60.0 g of e-1, 7.5 g of UA-122P, 0.4 g of L-1980N, and 0.4 g of G-700 were placed and mixed using a rotation-revolution vacuum mixer "Defoaming Mixer Taro (registered trademark)" ARE-310 (manufactured by THINKY Co., Ltd.) to obtain 85.1 g of resin solution. The obtained resin solution was mixed with 248.1 g of Ag particles and 1.6 g of AEROSIL R972, and kneaded using a three-roll mill (EXAKT M-50; manufactured by EXAKT) to obtain 334.8 g of a photosensitive paste.

In the process of <Manufacturing of a substrate with a photosensitive layer>, the same process as in Example 1 was carried out except that the drying conditions were changed as shown in Table 1. As a result, the content of the solvent (e) in the photosensitive layer was as shown in Table 1. Using the obtained substrate with a photosensitive layer, a ceramic green sheet with a conductive pattern was obtained in the same manner as in Example 1. The results of the evaluation by the above method are shown in Table 1.

(Example 11-Example 12) In the preparation of the photosensitive paste, e-2 was used instead of the solvent e-1. In the production of the substrate with a photosensitive layer, the same process as in Example 1 was performed except that the drying conditions were changed as described in Table 1. As a result, the content of the solvent (e) in the photosensitive layer was as shown in Table 1. Using the obtained substrate with a photosensitive layer, a ceramic green sheet with a conductive pattern was obtained in the same manner as in Example 1. The results of the evaluation by the above method are shown in Table 1.

(Example 13-Example 14) Instead of the <transfer step>, a <lamination step> was performed without peeling off the substrate with the photosensitive layer substrate, and instead of the <exposure step A>, an <exposure step B> was performed in which an exposure mask was brought into contact with the substrate with the photosensitive layer substrate and the substrate was peeled off after exposure. Ceramic green sheets with conductive patterns were obtained in the same manner as in Examples 11-12. The results of the evaluation by the above method are shown in Table 1.

(Example 15 to Example 22) Except that the thickness of the photosensitive layer and the drying conditions in <Manufacturing of a substrate with a photosensitive layer> are changed as described in Table 1, a substrate with a photosensitive layer is obtained in the same manner as in Example 1. Using the obtained substrate with a photosensitive layer, a ceramic green sheet with a conductive pattern is obtained in the same manner as in Example 1 except that the exposure step is changed as described in Table 1. The results of the evaluation by the above method are shown in Table 1.

(Comparative Example 3) Instead of the <transfer step>, a photosensitive paste was directly applied on a ceramic green sheet of a substrate with a ceramic green sheet, and dried at a temperature of 120°C for 4 minutes to form a photosensitive layer with a thickness of 11 μm. The content of the solvent (e) in the photosensitive layer is shown in Table 1. Using the obtained substrate with a photosensitive layer substrate, a ceramic green sheet with a conductive pattern was obtained in the same manner as in Example 1. The results of the evaluation by the above method are shown in Table 1.

(Comparative Example 4 to Comparative Example 5) Except that in the <Exposure Step>, exposure is performed without contacting the exposure mask, ceramic green sheets with conductive patterns are obtained in the same manner as in Examples 1 and 2. The results of the evaluation by the above method are shown in Table 1.

[Table 1] [Table 1] Preparation of photosensitive layer Solvent Alkaline soluble resin Drying conditions of the photosensitive layer Thickness of photosensitive layer (μm) Solvent content in photosensitive layer (mass %) Exposure steps Exposure Mask Contact Transferability Fine pattern processing Line width uniformity (μm) Disconnection probability (%) Type Boiling point (℃) Type Temperature (℃) Time (minutes) Temperature (℃) Pressure (MPa) Time(s) Resolution limit width (μm) Top Width - Bottom Width (μm) Embodiment 1 have e-1 173 c-1 55 15 11 1.0 A have 100.0 0.3 30 12 3 0.5 3 Embodiment 2 have e-1 173 c-1 55 10 11 4.0 A have 100.0 0.3 30 13 4 0.7 5 Embodiment 3 have e-1 173 c-1 55 20 11 0.05 A have 110.0 0.3 30 12 4 0.6 3 Embodiment 4 have e-1 173 c-1 55 15 11 1.0 B have 100.0 0.3 30 15 8 0.8 0 Embodiment 5 have e-1 173 c-1 55 10 11 4.0 B have 100.0 0.3 30 16 Unable to process 0.9 1 Embodiment 6 have e-1 173 c-1 55 20 11 0.05 B have 110.0 0.3 30 15 7 0.8 0 Embodiment 7 have e-1 173 c-1,c-2 55 15 11 1.0 A have 90.0 0.2 30 12 3 0.5 3 Embodiment 8 have e-1 173 c-1,c-2 55 10 11 4.0 A have 90.0 0.2 30 13 4 0.7 5 Embodiment 9 have e-1 173 c-1,c-3 55 15 11 1.0 A have 70.0 0.2 30 12 3 0.5 3 Embodiment 10 have e-1 173 c-1,c-3 55 10 11 4.0 A have 70.0 0.2 30 13 4 0.7 5 Embodiment 11 have e-2 145 c-1 55 10 11 1.0 A have 110.0 0.3 30 12 3 0.6 4 Embodiment 12 have e-2 145 c-1 55 7 11 4.0 A have 110.0 0.3 30 13 4 0.9 5 Embodiment 13 have e-2 145 c-1 55 10 11 1.0 B have 110.0 0.3 30 15 8 1 0 Embodiment 14 have e-2 145 c-1 55 7 11 4.0 B have 110.0 0.3 30 16 Unable to process 1.1 1 Embodiment 15 have e-1 173 c-1 55 15 7 1.0 A have 100.0 0.3 30 9 2 0.3 7 Embodiment 16 have e-1 173 c-1 55 10 7 4.0 A have 100.0 0.3 30 10 3 0.4 10 Embodiment 17 have e-1 173 c-1 55 15 7 1.0 B have 100.0 0.3 30 11 3 0.6 3 Embodiment 18 have e-1 173 c-1 55 10 7 4.0 B have 100.0 0.3 30 12 4 0.7 5 Embodiment 19 have e-1 173 c-1 55 15 28 1.0 A have 100.0 0.3 30 30 Unable to process 1.2 4 Embodiment 20 have e-1 173 c-1 55 10 28 4.0 A have 100.0 0.3 30 33 Unable to process 1.4 6 Embodiment 21 have e-1 173 c-1 55 15 28 1.0 B have 100.0 0.3 30 35 Unable to process 1.6 1 Embodiment 22 have e-1 173 c-1 55 10 28 4.0 B have 100.0 0.3 30 38 Unable to process 1.9 2 Comparison Example 1 have e-1 173 c-1 55 6 11 6.0 A have 100.0 0.3 30 The film surface is sticky and cannot contact the exposure mask. Comparison Example 2 have e-1 173 c-1 55 6 11 6.0 B have 100.0 0.3 30 19 Unable to process 0.9 15 Comparison Example 3 without e-1 173 c-1 (120) (4) 11 4.0 A have - - - 20 Unable to process 2.9 8 Comparison Example 4 have e-1 173 c-1 55 15 11 1.0 - without 100.0 0.3 30 18 Unable to process 2.4 2 Comparison Example 5 have e-1 173 c-1 55 10 11 4.0 - without 100.0 0.3 30 20 Unable to process 2.6 2

L: Opening width

FIG. 1 is a schematic diagram of a mask pattern of an exposure mask used in the embodiment.

L: opening width

Claims (13)

A method for manufacturing a ceramic green sheet with a conductive pattern comprises: Preparing a substrate with a photosensitive layer having a photosensitive layer containing conductive particles (a), non-conductive particles (b), an alkali-soluble resin (c), a photosensitive agent (d) and a solvent (e), wherein the content of the solvent (e) is 5.0 mass % or less, and transferring the photosensitive layer from the substrate to the ceramic green sheet (transfer step); Contacting an exposure mask with the photosensitive layer to expose the photosensitive layer (exposure step A); and Developing the exposed photosensitive layer to form a conductive pattern (development step). A method for manufacturing a ceramic green sheet with a conductive pattern comprises: Preparing a substrate with a photosensitive layer having a photosensitive layer containing conductive particles (a), non-conductive particles (b), an alkali-soluble resin (c), a photosensitive agent (d) and a solvent (e), wherein the content of the solvent (e) is 5.0 mass % or less, and laminating the substrate with the photosensitive layer on the ceramic green sheet in such a manner that the photosensitive layer contacts the ceramic green sheet (lamination step); Contacting an exposure mask with the substrate of the substrate with the photosensitive layer to expose the substrate (exposure step B); and Developing the exposed photosensitive layer to form a conductive pattern (development step). The method for producing a ceramic green sheet with a conductive pattern according to claim 1 or 2, wherein the content of the solvent (e) in the photosensitive layer is 0.1 mass % or more. The method for producing a ceramic green sheet with a conductive pattern as claimed in claim 1 or 2, wherein the alkali-soluble resin (c) comprises a carboxyl-containing resin having no unsaturated double bonds and has a glass transition temperature of 110° C. or less. The method for producing a ceramic green sheet with a conductive pattern according to claim 4, wherein the alkali-soluble resin (c) has a glass transition temperature of 30° C. or higher and 70° C. or lower. The method for producing a ceramic green sheet with a conductive pattern as described in claim 1 or 2, wherein the photosensitive layer contains polyether-modified polydimethylsiloxane. The method for manufacturing a ceramic green sheet with a conductive pattern as described in claim 1 or 2 further comprises: applying a photosensitive paste containing conductive particles (a), non-conductive particles (b), an alkali-soluble resin (c), a photosensitive agent (d) and a solvent (e) on a substrate by screen printing, and drying the paste to form a photosensitive layer, thereby obtaining the substrate with the photosensitive layer. The method for producing a ceramic green sheet with a conductive pattern according to claim 1 or 2, wherein the solvent (e) includes a solvent having a boiling point of 150° C. to 300° C. under atmospheric pressure. The method for producing a ceramic green sheet with a conductive pattern according to claim 1 or 2, wherein the thickness of the photosensitive layer exceeds 10 μm and is 25 μm or less. The method for producing a ceramic green sheet with a conductive pattern as described in claim 1 or 2, wherein the ceramic green sheet contains a photosensitive organic component. A method for manufacturing a laminated body is a method for manufacturing a laminated body formed by laminating a plurality of ceramic green sheets with conductive patterns, and comprises: A step of obtaining a ceramic green sheet with a conductive pattern by forming a first conductive pattern by the method for manufacturing a ceramic green sheet with a conductive pattern as described in claim 1 or 2; A step of forming a ceramic green sheet on the conductive pattern side of the ceramic green sheet with the first conductive pattern; and A step of forming a second conductive pattern on the ceramic green sheet on which the ceramic green sheet with the first conductive pattern is formed by the method for manufacturing a ceramic green sheet with a conductive pattern as described in claim 1 or 2. A method for manufacturing a laminate is a method for manufacturing a laminate formed by laminating a plurality of ceramic green sheets with conductive patterns, and comprises: A step of obtaining a plurality of ceramic green sheets with conductive patterns by the method for manufacturing a ceramic green sheet with conductive patterns as described in claim 1 or 2; and A step of laminating a plurality of ceramic green sheets with conductive patterns and performing heat pressing. A method for manufacturing a sintered body comprises: a step of obtaining a ceramic green sheet with a conductive pattern by the manufacturing method as described in claim 1 or 2; and a step of sintering the obtained ceramic green sheet with a conductive pattern.

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