KR20210004941A - Photosensitive conductive paste and method for manufacturing patterned green sheet using the same - Google Patents

Abstract

A photosensitive conductive paste capable of forming a high-definition pattern on a green sheet and suppressing firing defects is provided. Containing conductive powder (A), alkali-soluble resin (B), reactive compound (C), and photopolymerization initiator (D), wherein the reactive compound (C) has a viscosity of 5.0 to 100.0 Pa·s at 60°C. It is a photosensitive conductive paste.

Description

Photosensitive conductive paste and method for manufacturing patterned green sheet using the same

The present invention relates to a photosensitive conductive paste, a cured product and a fired body thereof, an electronic component using the same, a method for manufacturing the same, a method for manufacturing a patterned green sheet, and a method for manufacturing an electronic component.

BACKGROUND ART In recent years, as high-speed, high-frequency, and miniaturized electronic components progress, it is required to form a fine, high-density conductive pattern on a ceramic substrate for mounting them. As a method of forming a conductive pattern on a ceramic green sheet, which is one of ceramic substrates, for example, a photosensitive resin composition is printed on the green sheet and dried to form a photosensitive film layer, and a photomask is placed on the photosensitive film layer to expose , A method of forming a pattern on a green sheet, characterized in that the pattern is formed by developing, is proposed (see, for example, Patent Document 1). In addition, as a photosensitive conductive paste for forming a conductive pattern, for example, a photosensitive conductive paste containing an inorganic component including an inorganic filler made of a conductive powder, a glass frit, and a ceramic powder, and a photosensitive organic component (for example, Patent Document 2) or a photosensitive conductive paste containing an organic binder, a conductive powder, a photopolymerizable compound, a photopolymerization initiator, and an organic solvent containing an ionic group in the side chain that changes to a nonionic group by light irradiation (for example , See Patent Document 3) and the like have been proposed.

Japanese Patent Laid-Open No. 2004-264655 Japanese Patent Laid-Open No. 2011-204514 Japanese Patent Publication No. 2016-194641

However, the techniques described in Patent Literatures 1 to 3 have a problem in that the photosensitive component in the photosensitive resin composition or the photosensitive conductive paste is easily absorbed by the green sheet, so that a decrease in sensitivity is likely to occur and formation of a high-definition pattern is difficult.

In addition, since the influence of the plastic defect becomes more pronounced due to the miniaturization and density of the conductive pattern in recent years, it is required to suppress the plastic defect.

Accordingly, an object of the present invention is to provide a photosensitive conductive paste capable of forming a high-definition pattern on a green sheet and suppressing plastic defects.

The above object is achieved by the following technical means.

Containing conductive powder (A), alkali-soluble resin (B), reactive compound (C), and photopolymerization initiator (D), wherein the reactive compound (C) has a viscosity of 5.0 to 100.0 Pa·s at 60°C. Photosensitive conductive paste.

(Effects of the Invention)

According to the photosensitive conductive paste of the present invention, a highly detailed conductive pattern can be formed on a green sheet, and plastic defects can be suppressed.

The photosensitive conductive paste of the present invention contains a conductive powder (A), an alkali-soluble resin (B), a reactive compound (C), and a photoinitiator (D). By containing the conductive powder (A), the conductive powders (A) can be brought into contact with each other by firing to exhibit conductivity. By containing an alkali-soluble resin (B), solubility in an alkali developer is imparted, and by containing a reactive compound (C) and a photopolymerization initiator (D), pattern processability by photolithography can be improved. In the present invention, it is important that the reactive compound (C) has a viscosity of 5.0 to 100.0 Pa·s at 60°C. As described above, in the conventionally known photosensitive conductive paste, since the photosensitive component is easily absorbed by the green sheet in pattern formation on the green sheet, the sensitivity is easily deteriorated and it is difficult to form a high-definition pattern. According to the examination of the present inventors, it was found that absorption into the green sheet is related to the viscosity of the reactive compound in the drying step described later. Therefore, in the present invention, as an index of the viscosity of the reactive compound in the drying step, attention was paid to the viscosity at 60°C, which is a general drying temperature in the drying step. In the present invention, when the viscosity of the reactive compound (C) at 60° C. is 5.0 Pa·s or more, absorption into the green sheet can be suppressed to form a fine pattern. On the other hand, if the viscosity of the reactive compound (C) at 60° C. becomes too high, it becomes difficult to remove and remove the reactive compound (C) remaining during firing, and firing defects are liable to occur. In the present invention, plastic defects can be suppressed by setting the viscosity of the reactive compound (C) at 60° C. to 100.0 Pa·s or less.

Examples of the conductive powder (A) include metals such as silver, gold, copper, platinum, palladium, tin, nickel, aluminum, tungsten, molybdenum, ruthenium oxide, chromium, titanium, indium, and powders of these alloys; And carbon powder. You may contain 2 or more types of these. Among these, silver, copper, and gold are preferable from the viewpoint of conductivity, and silver is more preferable from the viewpoint of cost and stability.

The median diameter (D50) of the conductive powder (A) is preferably 0.1 to 10 µm. By setting the D50 of the conductive powder (A) to 0.1 µm or more, the probability of contact between the conductive powders (A) at the time of firing is improved, and the volume resistivity of the conductive pattern and the probability of disconnection can be reduced. Further, since the transmittance of the exposure light is improved in the exposure/development step described later, a more detailed pattern can be easily formed. D50 of the conductive powder (A) is more preferably 0.5 µm or more. On the other hand, by setting the D50 of the conductive powder (A) to 10 µm or less, the residue can be suppressed, and a more fine pattern can be easily formed. D50 of the conductive powder (A) is more preferably 5 µm or less. In addition, D50 of the conductive powder (A) can be measured by a laser light scattering method using a particle size distribution measuring apparatus (Microtrac HRA Model No. 9320-X100; manufactured by NIKKISO CO., LTD.).

The content of the conductive powder (A) in the photosensitive conductive paste is preferably 20 to 50% by volume based on the total solid content. By setting the content of the conductive powder (A) to 20% by volume or more, the probability of contact between the conductive powders (A) during firing can be improved, and the volume resistivity and the probability of disconnection of the conductive pattern can be reduced. In addition, adhesion between chips can be suppressed in the dicing step described later. The content of the conductive powder (A) is more preferably 25% by volume or more, and more preferably 35% by volume or more. On the other hand, when the content of the conductive powder (A) is 50% by volume or less, a more detailed pattern can be easily formed because the transmittance of the exposure light is improved in the exposure and development steps described later. The content of the conductive powder (A) is more preferably 45% by volume or less. Here, the total solid content of the photosensitive conductive paste refers to all constituent components of the photosensitive conductive paste excluding the solvent.

The content of the conductive powder (A) in the photosensitive conductive paste is a transmission electron microscope (for example, "JEM-4000EX" manufactured by JEOL Ltd.) using a cross section perpendicular to the film surface of the dry paste film from which the solvent was removed by applying and drying the photosensitive paste. It can be observed by, and determined by performing image analysis by distinguishing the conductive powder (A) from the other components by the shade of the image. At this time, the observation area by the transmission electron microscope is about 20 μm×100 μm, and the magnification is about 1,000 to 3,000 times. In addition, when the compounding amount of each component of the photosensitive conductive paste is known, the content of the conductive powder (A) can also be calculated from the compounding amount.

In the photosensitive conductive paste of the present invention, the alkali-soluble resin (B) refers to a resin having an alkali-soluble group. As an alkali-soluble group, a carboxyl group, a phenolic hydroxyl group, a sulfonic acid group, a thiol group, etc. are mentioned, for example. A carboxyl group is preferred because of its high solubility in an alkaline developer.

The glass transition point of the alkali-soluble resin (B) is preferably 80 to 160°C. Even when the glass transition point of the alkali-soluble resin (B) is heated to about 70°C in the drying process described later, absorption to the green sheet due to softening of the alkali-soluble resin (B) is further suppressed and the Fine patterns can be easily formed. In addition, adhesion between chips can be suppressed in the dicing step described later. The glass transition point of the alkali-soluble resin (B) is more preferably 100°C or higher. On the other hand, by setting the glass transition point of the alkali-soluble resin (B) to 160°C or less, the thermal decomposition property can be improved, and firing defects caused by residual organic components during firing can be more suppressed. The glass transition point of the alkali-soluble resin (B) is more preferably 140°C or less. When the alkali-soluble resin (B) contains two or more different kinds of glass transition points, it is preferable that the glass transition points of all alkali-soluble resins (B) are in the above range. In addition, the glass transition point of the alkali-soluble resin (B) can be measured by differential scanning calorimetry (DSC) using a differential scanning calorimeter (DSC-50; SHIMADZU CORPORATION).

As the alkali-soluble resin (B), an acrylic resin is preferable, and a copolymer of an acrylic monomer having a carbon-carbon double bond and other monomers is preferable. As an acrylic monomer having a carbon-carbon double bond, for example, methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, tert-butyl acrylate , n-pentyl acrylate, isodecyl acrylate, isooctyl acrylate, 2-ethylhexyl acrylate, allyl acrylate, lauryl acrylate, stearyl acrylate, and other C1-C18 chain aliphatic hydrocarbon groups Rate; Acrylates having a cyclic aromatic hydrocarbon group having 6 to 10 carbon atoms such as benzyl acrylate, phenyl acrylate, 1-naphthyl acrylate and 2-naphthyl acrylate; Cyclohexyl acrylate, dicyclopentanyl acrylate, 4-tert-butyl cyclohexyl acrylate, dicyclopentenyl acrylate, dicyclopentadienyl acrylate, isobornyl acrylate, 3,3,5-trimethylcyclohexyl And acrylates having a cyclic aliphatic hydrocarbon group having 6 to 15 carbon atoms such as acrylate, and those obtained by replacing these acrylates with methacrylates. You may use 2 or more types of these. Examples of the copolymerization component other than the acrylic monomer include styrenes such as styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, chloromethylstyrene, and hydroxymethylstyrene; And unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, crotonic acid, maleic acid, fumaric acid, and vinyl acetic acid, and acid anhydrides thereof. You may use 2 or more types of these.

The acrylic resin preferably has a carbon-carbon double bond at the side chain or molecular terminal, and can improve the curing reaction rate during exposure (hereinafter, an acrylic resin having a carbon-carbon double bond is used as an acrylic resin (b- 1) may be stated). As a structure having a carbon-carbon double bond, a vinyl group, an allyl group, an acrylic group, a methacrylic group, etc. are mentioned, for example. You may have two or more of these. As a method of introducing a carbon-carbon double bond into an acrylic resin, for example, a compound having a glycidyl group or an isocyanate group and a carbon-carbon double bond with respect to a mercapto group, an amino group, a hydroxyl group, or a carboxyl group in the acrylic resin, A method of reacting acrylic acid chloride, methacrylic acid chloride, and allyl chloride, etc. are mentioned.

Examples of the compound 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 (above, manufactured by Daicel Corporation), and the like. Examples of the compound having an isocyanate group and a carbon-carbon double bond include acryloyl isocyanate, methacryloyl isocyanate, acryloyl ethyl isocyanate, and methacryloyl ethyl isocyanate. You may use 2 or more types of these.

The acid value of the acrylic resin (b-1) is preferably 50 to 150 mgKOH/g from the viewpoint of solubility in an alkali developer. The acid value of the acrylic resin can be adjusted by the copolymerization ratio of the unsaturated acid. In addition, the acid value of an acrylic resin can be calculated|required by neutralization titration using potassium hydroxide aqueous solution.

The photosensitive conductive paste of the present invention, in addition to the acrylic resin (b-1), does not have a carbon-carbon bond, and has an acid value of 200 to 300 mgKOH/g (hereinafter, when described as acrylic resin (b-2) It is preferable to include). Since it does not have a carbon-carbon double bond, crosslinking due to exposure is not generated, so that fluctuations in the acid value before and after curing are small, and a desired effect by limiting the numerical value of the acid value can be easily obtained. When the acid value of the acrylic resin (b-2) is made larger than 200 mgKOH/g, the interaction between the acrylic resins by hydrogen bonds acts, and adhesion can be suppressed in the dicing step described later. The acid value of the acrylic resin (b-2) is more preferably 220 mgKOH/g or more. On the other hand, by setting the acid value of the acrylic resin (b-2) to 300 mgKOH/g or less, the elution rate can be appropriately suppressed in the exposure/development step described later, and a more detailed pattern can be easily formed. The acid value of the acrylic resin (b-2) is more preferably 280 mgKOH/g or less.

The weight average molecular weight (Mw) of the acrylic resin (b-2) is preferably 20,000 to 50,000. By making Mw of the acrylic resin (b-2) 20,000 or more, adhesion in a dicing process can be suppressed more. Further, it is possible to form a finer pattern by suppressing pattern peeling in the exposure/development process. As for Mw of the acrylic resin (b-2), 23,000 or more are more preferable, and 32,000 or more are still more preferable. On the other hand, by setting Mw of the acrylic resin (b-2) to 50,000 or less, the solubility in the developing solution in the exposure/development process can be improved, and the residue can be suppressed to form a finer pattern. The Mw of the acrylic resin (b-2) is more preferably 45,000 or less, and still more preferably 42,000 or less. Mw of the acrylic resin (b-2) is a value in terms of polystyrene, and can be measured using high performance liquid chromatography (Alliance 2695; manufactured by Nihon Waters K.K.) or the like.

The glass transition point of an acrylic resin can be adjusted by a polymerization component, for example. Examples of the acrylic monomer constituting the acrylic resin having a high glass transition point include acrylates having a chain aliphatic hydrocarbon group such as methyl methacrylate, tert-butyl methacrylate, and (meth)acrylate; 4-tert-butylcyclohexylmethacrylate, dicyclopentanyl (meth)acrylate, dicyclopentadienyl (meth)acrylate, isobornyl (meth)acrylate, 3,3,5-trimethylcyclohexylmethacryl (Meth)acrylates having a cyclic aliphatic hydrocarbon group having 6 to 15 carbon atoms such as rate, etc. are mentioned. Other monomers constituting the acrylic resin having a high glass transition point include, for example, acrylonitrile, acrylamide, and styrene.

As an acrylic resin (b-1) having a glass transition point of 80 to 160°C, for example, "CYCLOMER (registered trademark)" P(ACA)Z200M, P(ACA)Z230AA, P(ACA)Z250, P(ACA)Z251 , P(ACA)Z300, P(ACA)Z320, P(ACA)Z254F (above, manufactured by DAICEL-ALLNEX LTD.), and the like. As the acrylic resin (b-2), a (meth)acrylic acid/(meth)acrylate methyl/styrene copolymer is preferable, and adhesion in a dicing step can be further suppressed.

The weight average molecular weight of the alkali-soluble resin (B) is preferably 7,000 to 40,000. By making the weight average molecular weight of the alkali-soluble resin (B) 7,000 or more, the viscosity of the photosensitive conductive paste can be suitably improved, and the chin of a dried film mentioned later can be suppressed. The weight average molecular weight of the alkali-soluble resin (B) is more preferably 24,000 or more. On the other hand, by setting the weight average molecular weight of the alkali-soluble resin (B) to 40,000 or less, the solubility of the non-exposed portion to the developer in the exposure/development step described later can be improved and the development time can be shortened. The weight average molecular weight of the alkali-soluble resin (B) is more preferably 32,000 or less. When 2 or more types of alkali-soluble resins (B) are contained, it is preferable that at least one type is included in the above range, and it is more preferable that all of them are included in the above range. The weight average molecular weight of the alkali-soluble resin is a value in terms of polystyrene, and can be measured using high performance liquid chromatography (Alliance 2695; manufactured by Nihon Waters K.K.) or the like.

The content of the alkali-soluble resin (B) in the photosensitive conductive paste is preferably 20 to 55% by volume based on the total solid content. By setting the content of the alkali-soluble resin (B) to 20% by volume or more, absorption into the green sheet can be more suppressed in pattern formation on the green sheet, and a more fine pattern can be easily formed. In addition, adhesion in the dicing step can be further suppressed. The content of the alkali-soluble resin (B) is more preferably 30% by volume or more. On the other hand, by setting the content of the alkali-soluble resin (B) to 55% by volume or less, the viscosity of the photosensitive conductive paste can be appropriately maintained, and firing defects caused by remaining organic components during firing can be further suppressed. The content of the alkali-soluble resin (B) is more preferably 45% by volume or less.

The content of the acrylic resin (b-1) in the photosensitive conductive paste is preferably 20 to 45% by volume based on the total solid content. When the content of the acrylic resin (b-1) is 20% by volume or more, crosslinking in the exposure/development process is promoted, pattern peeling is suppressed, and a finer pattern can be formed. On the other hand, by making the content of the acrylic resin (b-1) 45% by volume or less, adhesion in the dicing step can be further suppressed.

The content of the acrylic resin (b-2) in the photosensitive conductive paste is preferably 1 to 20% by volume based on the total solid content. By setting the content of the acrylic resin (b-2) to 1% by volume or more, adhesion in the dicing step can be further suppressed. The content of the acrylic resin (b-2) is more preferably 7% by volume or more. On the other hand, by setting the content of the acrylic resin (b-2) to 20% by volume or less, pattern peeling caused by excessive elution of the acrylic resin (b-2) in the developing step can be suppressed, thereby forming a finer pattern. . The content of the acrylic resin (b-2) is more preferably 15% by volume or less.

Further, it is preferable to contain 20 to 40 parts by volume of the acrylic resin (b-2) with respect to 100 parts by volume in total of the acrylic resin (b-1) and the acrylic resin (b-2). By setting the content of the acrylic resin (b-2) to 20 parts by volume or more, adhesion in the dicing step can be further suppressed. On the other hand, by setting the content of the acrylic resin (b-2) to 40 parts by volume or less, pattern peeling caused by excessive elution of the acrylic resin (b-2) in the developing step can be further suppressed and a finer pattern can be formed. have.

The reactive compound (C) in the present invention refers to a monomer or oligomer having a carbon-carbon double bond.

It is important that the viscosity of the reactive compound (C) at 60° C. is 5.0 to 100.0 Pa·s. If the viscosity of the reactive compound (C) at 60° C. is less than 5.0 Pa·s, the reactive compound (C) is easily absorbed into the green sheet in the drying step described later, and thus it becomes difficult to form a high-definition pattern due to a decrease in sensitivity. . The viscosity of the reactive compound (C) at 60° C. is preferably 15.0 Pa·s or more. On the other hand, when the viscosity at 60°C of the reactive compound (C) exceeds 100.0 Pa·s, firing defects due to remaining organic components during firing are likely to occur. The viscosity of the reactive compound (C) at 60° C. is preferably 50.0 Pa·s or less. In the present invention, the viscosity of the reactive compound (C) at 60° C. is the reactive compound (C), wherein the viscosity of at least one reactive compound (C) is within the above range when two or more types having different viscosities are contained. . In addition, the viscosity at 60°C of the reactive compound (C) was measured at a rotational speed of 3 rpm using a B-type viscometer (Brookfield viscometer, model HB DV-I; manufactured by EKO INSTRUMENTS CO., LTD.) under atmospheric pressure. Say one value.

Examples of the reactive compound (C) having a viscosity of 5.0 to 100.0 Pa·s at 60°C include a urethane acrylate oligomer and an epoxy acrylate oligomer. More specifically, for example "SARTOMER (registered trademark)" CN940, CN961, CN962, CN963, CN964, CN965, CN966, CN980, CN989, CN8881NS, CN8883NS, CN8884NS, CN9001, CN9004, CN9013, CN9025, CN9030, CN9893 , CN971, CN973, CN9782, CN9783, CN2920, CN104 (above, manufactured by ARKEMA KK), NK oligo UA-122P, U-2PPA, U-6LPA, EA-1020, EA-1020LC3 (above, SHIN-NAKAMURA CHEMICAL CO. , LTD.), "KAYARAD (registered trademark)" UX-3204, UX-4101, UXT-6100, UX-6101, UX-7101, UX-8101, UXF-4002, UX-5103D (above, Nippon Kayaku Co ., Ltd. product), "EBECRYL (registered trademark)" 8465, 8804 (above, DAICEL-ALLNEX LTD. product), and the like.

It is preferable that the reactive compound (C) has a urethane structure and/or an ester structure. By having a urethane structure and/or an ester structure, it is possible to easily form a more detailed pattern by improving flexibility. It is more preferable to have a urethane structure and an ester structure. As the reactive compound (C) having a urethane structure, for example "SARTOMER (registered trademark)" CN940, CN961, CN962, CN963, CN964, CN965, CN966, NK oligo UA-122P, U-2PPA, U-6LPA, " KAYARAD (registered trademark)" UX-3204, UX-4101, UXT-6100, UX-6101, UX-7101, UX-8101, UXF-4002, "EBECRYL (registered trademark)" 8465, 8804, and the like. As the reactive compound (C) having an ester structure, for example, "SARTOMER (registered trademark)" CN961, CN962, "KAYARAD (registered trademark)" UX-3204, UX-4101, UXT-6100, UX-6101, UX- 7101, UX-8101, NK oligo UA-122P, etc. are mentioned.

The weight average molecular weight of the reactive compound (C) is preferably 5,000 to 45,000. By setting the weight average molecular weight of the reactive compound (C) to 5,000 or more, absorption into the green sheet is more suppressed in pattern formation on the green sheet, and a more detailed pattern can be easily formed even when the standing time after drying is longer. have. The weight average molecular weight of the reactive compound (C) is more preferably 10,000 or more, and more preferably 15,000 or more. On the other hand, by setting the weight average molecular weight of the reactive compound (C) to 45,000 or less, the viscosity of the photosensitive conductive paste can be appropriately maintained, and firing defects caused by residual organic components during firing can be further suppressed. The weight average molecular weight of the reactive compound (C) is more preferably 40,000 or less. As the reactive compound (C) having a weight average molecular weight of 5,000 to 45,000, for example, a polyol such as polyether diol and polycarbonate diol, and a polyisocyanate polymer such as isophorone diisocyanate have a carbon-carbon double bond. It can be obtained by reacting alcohol. In addition, examples of the reactive compound (C) available on the market include "KAYARAD (registered trademark)" UX-3204, UX-4101, UXT-6100, UX-6101, UXF-4002, and the like.

The solubility parameter (SP value) of the reactive compound (C) is preferably 21.5 to 28.7 (J/cm 3) ^1/2 . By setting the SP value in this range, absorption into the green sheet can be further suppressed, and a more detailed pattern can be easily formed. In addition, the SP value of the reactive compound (C) can be calculated from the molecular structure using Fedors' calculation method.

The content of the reactive compound (C) in the photosensitive conductive paste is preferably 5 to 30% by volume based on the total solid content. By making the content of the reactive compound (C) 5% by volume or more, the sensitivity in the exposure/development step described later can be improved, and a more detailed pattern can be easily formed. The content of the reactive compound (C) is more preferably 10% by volume or more. On the other hand, by setting the content of the reactive compound (C) to 30% by volume or less, the viscosity of the photosensitive conductive paste can be appropriately maintained, and firing defects caused by residual organic components during firing can be further suppressed. The content of the reactive compound (C) is more preferably 20% by volume or less.

The photoinitiator (D) in the present invention refers to a compound that absorbs and decomposes light of a short wavelength such as ultraviolet rays, or generates a radical through a hydrogen extraction reaction. As a photoinitiator (D) that absorbs and decomposes light such as ultraviolet rays, for example, 1,2-octanedione, benzophenone, methyl ortho-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-azidebenzalacetophenone, Alkylphenone-based photopolymerization initiators such as 2,6-bis(p-azidebenzylidene)cyclohexanone and 6-bis(p-azidebenzylidene)-4-methylcyclohexanone; Acylphosphine oxide-based photopolymerization initiators such as 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide and bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide; 1-[4-(phenylthio)-2-(O-benzoyloxime)], ethanone, 1-[9-ethyl-6-2(2-methylbenzoyl)-9H-carbazol-3-yl]- 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-propanetrione-2-(O-ethoxycarbonyl)oxime, 1-phenyl-3-ethoxy-propane Trione-2-(O-benzoyl) oxime oxime ester type photoinitiators, etc. are mentioned. Examples of the photopolymerization initiator (D) that generate radicals by hydrogen drawing reaction include benzophenone, anthraquinone, thioxanthone, and phenylglyoxylic acid methyl ester. You may contain 2 or more types of these.

The content of the photoinitiator (D) in the photosensitive conductive paste is preferably 0.1 to 5.0% by volume. By setting the content of the photopolymerization initiator (D) to 0.1% by volume or more, the sensitivity in the exposure/development step described later can be improved, and a more detailed pattern can be easily formed. The content of the photoinitiator (D) is more preferably 0.2% by volume or more. On the other hand, by setting the content of the photopolymerization initiator (D) to 5.0% by volume or less, light absorption on the surface of the dried film in the exposure/development step described later is appropriately suppressed, and residues are suppressed to facilitate formation of a more detailed pattern. I can. The content of the photoinitiator (D) is more preferably 3.0% by volume or less.

In addition, with respect to 100 parts by volume of the alkali-soluble resin (B), the reactive compound (C), and the photopolymerization initiator (D) in the photosensitive conductive paste, the total amount of the alkali-soluble resin (B) and the reactive compound (C) is 90.0 to 99.1 volumes in total. It is preferable to contain. By setting the total content of the alkali-soluble resin (B) and the reactive compound (C) to 90.0 parts by volume or more, light absorption on the surface of the dried film in the exposure/development step described later is appropriately suppressed, and the residue is suppressed, resulting in a more fine-grained method. The pattern can be easily formed. On the other hand, when the total content of the alkali-soluble resin (B) and the reactive compound (C) is 99.0 parts by volume or less, the sensitivity in the exposure/development step described later can be improved, and a more detailed pattern can be easily formed. In addition, by appropriately maintaining the viscosity of the photosensitive conductive paste, plastic defects can be further suppressed.

It is preferable that the content of the organic component having a molecular weight of 5,000 or less among the organic components of the solid content at 23°C in the photosensitive conductive paste of the present invention is 4.0 to 15.0% by volume. An organic component having a molecular weight of 5,000 or less easily moves in the photosensitive conductive paste, and is easily absorbed by the green sheet from one having high reactivity during exposure. Therefore, a desired effect can be obtained more easily by numerical regulation of the content of an organic component having a molecular weight of 5,000 or less. When the content of the organic component having a molecular weight of 5,000 or less is 4.0% by volume or more, the sensitivity in the exposure/development process described later is improved, and a more fine pattern can be easily formed even when the standing time after drying is longer. On the other hand, by setting the content of the organic component having a molecular weight of 5,000 or less to 15.0% by weight or less, absorption into the green sheet is more suppressed in the pattern formation on the green sheet, and a more detailed pattern is facilitated even when the standing time after drying is longer. Can be formed.

It is preferable that the weight average molecular weight of the organic component in the solid content at 23 degreeC in the photosensitive conductive paste of this invention is 30,000-45,000. By setting the weight average molecular weight of the organic component to 30,000 or more, the movement of the organic component is appropriately suppressed. Therefore, absorption into the green sheet is more suppressed in pattern formation on the green sheet, and even when the standing time after drying is longer Fine patterns can be easily formed. On the other hand, by setting the weight average molecular weight of the organic component to 45,000 or less, the viscosity of the photosensitive conductive paste can be appropriately maintained, and firing defects caused by residual organic components during firing can be further suppressed. The weight average molecular weight of the organic component is more preferably 37,000 or less.

It is preferable that the photosensitive conductive paste of the present invention further contains fine particles (E) having a particle diameter of 1 to 100 nm, and pattern shrinkage at the time of firing can be suppressed. Here, the fine particles (E) are components other than the above-described conductive powder (A). As the fine particles (E), for example, alumina (Al ₂ O ₃ ), zirconia (ZrO ₂ ), magnesia (MgO), beryllia (BeO), mullite (3Al ₂ O ₃ ·2SiO ₂ ), cordierite (5SiO) ₂ ·2Al ₂ O ₃ ·2MgO), Spinel (MgO·Al ₂ O ₃ ), Forsterite (2MgO·SiO ₂ ), Anosite (CaO·Al ₂ O ₃ ·2SiO ₂ ), Celsian (BaO·Al ₂ O ₃ ·2SiO ₂ ), silica (SiO ₂ ), aluminum nitride (AlN), ferrite (garnet type: Y ₃ Fe ₅ O ₁₂ system, spinel type: MeFe ₂ O ₄ system) SiO ₂ , Al ₂ O ₃ , Glass powder containing CaO, B ₂ O ₃ , MgO, and/or TiO ₂ and the like; Inorganic filler powders, such as alumina, zirconia, magnesia, beryllia, mullite, cordierite, spinel, forsterite, anoxite, celsian, silica, and aluminum nitride, etc. are mentioned. You may contain 2 or more types of these. Among these, titania, alumina, silica, cordierite, mullite, spinel, barium titanate, and zirconia are preferable from the viewpoint of further suppressing plastic defects.

The fine particles (E) in the present invention indicate that the particle diameter is 1 to 100 nm, but it is difficult to individually specify the particle diameter of the fine particles (E), and the volume average particle diameter is 1 to 100 nm. desirable. By setting the volume average particle diameter of the fine particles (E) to 1 nm or more, the sintering rate of the conductive powder (A) at the time of firing can be adjusted, and firing defects can be further suppressed. On the other hand, by making the volume average particle diameter of the fine particles (E) 100 nm or less, the interaction between the fine particles (E) and the alkali-soluble resin (B), the reactive compound (C), and the photopolymerization initiator (D) results in a green sheet. Absorption can be suppressed to form a finer pattern. Further, the volume resistivity of the pattern can be reduced. The volume average particle diameter of the fine particles (E) is more preferably 50 nm or less. In addition, the volume average particle diameter of the fine particles (E) can be obtained by adding the fine particles (E) to water and performing ultrasonic treatment for 300 seconds, and then using a Nanotrac WaveII-UZ251 (manufactured by MicrotracBEL Corp.) by a dynamic light scattering method. In addition, since the volume average particle diameter of the fine particles (E) does not change before and after the photosensitive conductive paste is mixed, it may be measured for the fine particles (E) before the photosensitive conductive paste is mixed, or measured by collecting the fine particles (E) from the photosensitive conductive paste. You can do it.

It is preferable that the microparticles|fine-particles (E) are hydrophilic, and can form a finer pattern easily by suppressing the residue in the exposure and development process mentioned later. In the present invention, hydrophilicity refers to having a hydrophilic group on the surface. As a hydrophilic group, a hydroxyl group, a carboxyl group, etc. are mentioned, for example. The fine particles (E) having a hydroxyl group on the surface are obtained by a high-temperature hydrolysis method or the like. More specifically, for example, "AEROSIL (registered trademark)" OX50, 50, 90G, 130, 150, 200, 200CF, 200V, 300, 380, TT600, "AEROXIDE (registered trademark)" AluC, Alu65, Alu130 ( As mentioned above, Nippon Aerosil Co., Ltd. product), "SEAHOSTAR (registered trademark)" KE-S10 (NIPPON SHOKUBAI CO., LTD. product), etc. are mentioned. As the fine particles (E) having a carboxyl group on the surface, it can be obtained, for example, by subjecting the fine particles to a wet surface treatment.

The content of the fine particles (E) in the photosensitive conductive paste is preferably 0.1 to 25.0 parts by volume per 100 parts by volume of the conductive powder (A). By adjusting the content of the fine particles (E) to 0.1 part by volume or more, the sintering rate of the conductive powder (A) during firing can be adjusted, and firing defects can be further suppressed. Further, since the transmittance of the exposure light is improved in the exposure/development step described later, a more detailed pattern can be easily formed. The content of the fine particles (E) is more preferably 1.0 part by volume or more. On the other hand, by making the content of the fine particles (E) 25.0 parts by volume or less, the volume resistivity of the pattern can be reduced. The content of the fine particles (E) is more preferably 10.0 parts by volume or less.

It is preferable that the photosensitive conductive paste of this invention further contains a solvent (F). As the solvent (F), for example, N,N-dimethylacetamide, N,N-dimethylformamide, N-methyl-2-pyrrolidone, dimethylimidazolidinone, dimethyl sulfoxide, 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 cyclohexanol acetate. You may contain 2 or more types of these.

From the viewpoint of the solubility of the alkali-soluble resin (B), the reactive compound (C), the photopolymerization initiator (D), and other components as necessary, and from the viewpoint of more suppressing the residue and easily forming a finer pattern The SP value of (F) is preferably 19.5 to 21.3 (J/cm 3) ^1/2 . As a solvent (F) having an SP value of 19.5 to 21.3 (J/cm 3) ^1/2 , for example, N,N-dimethylformamide, N-methyl-2-pyrrolidone, dimethylimidazolidinone, dipropylene Glycol n-propyl ether, dipropylene glycol n-butyl ether, tripropylene glycol methyl ether, tripropylene glycol-n-butyl ether, diethylene glycol monomethyl ether acetate, cyclohexanol acetate, and the like. In addition, the SP value of the solvent can be calculated from the molecular structure of the solvent using Fedors' calculation method.

The solvent (F) preferably contains a low boiling point solvent (f-1) having a boiling point of 150°C or higher and less than 200°C, and a high boiling point solvent (f-2) having a boiling point of 200°C or higher and 250°C or lower. By including the low boiling point solvent (f-1), the residual solvent after drying can be reduced, and adhesion at the time of low temperature drying and adhesion at the dicing step can be further suppressed. On the other hand, by including the high boiling point solvent (f-2), excessive volatilization of the solvent in the coating step can be suppressed, and an increase in viscosity can be suppressed. Examples of the low boiling point solvent (f-1) include N,N-dimethylacetamide (165°C), N,N-dimethylformamide (153°C), dimethyl sulfoxide (189°C), and dipropylene glycol methyl ether ( 190℃), ethyl lactate (154℃), ethylene glycol mono-n-propyl ether (151℃), diacetone alcohol (166℃), tetrahydrofurfuryl alcohol (176℃), cyclohexanol acetate (173℃) And the like. As the high boiling point solvent (f-2), for example, N-methyl-2-pyrrolidone (202°C), dimethylimidazolidinone (225°C), diethylene glycol monoethyl ether (202°C), dipropylene Glycol n-propyl ether (212° C.), dipropylene glycol n-butyl ether (230° C.), tripropylene glycol methyl ether (242° C.), diethylene glycol monoethyl ether acetate (217° C.), dipropylene glycol methyl ether acetate (213°C), propylene glycol phenyl ether (243°C), diethylene glycol monobutyl ether (230°C), diethylene glycol monobutyl ether acetate (247°C), γ-butyrolactone (204°C), and the like. have. Here, the boiling point of the solvent (F) is disclosed in various documents.

The content of the low boiling point solvent (f-1) in the photosensitive conductive paste of the present invention is preferably 1.0 to 15.0% by volume. By setting the content of the low boiling point solvent (f-1) to 1.0% by volume or more, the residual amount of the solvent (F) after drying can be reduced, and adhesion during low-temperature drying and adhesion in the dicing step can be further suppressed. On the other hand, by setting the content of the low boiling point solvent (f-1) to 15.0% by volume or less, an increase in viscosity caused by excessive volatilization of the solvent (F) in the coating step can be suppressed.

The content of the high boiling point solvent (f-2) in the photosensitive conductive paste of the present invention is preferably 1.0 to 15.0% by volume. When the content of the high boiling point solvent (f-2) is 1.0% by volume or more, an increase in viscosity due to excessive volatilization of the solvent (F) in the coating step can be suppressed. On the other hand, by setting the content of the high boiling point solvent (f-2) to 15.0% by volume or less, the residual amount of the solvent (F) after drying can be reduced, and adhesion during low temperature drying and adhesion in the dicing step can be more suppressed. .

Further, it is preferable to contain 25 to 65 parts by volume of the low-boiling-point solvent (f-1) with respect to 100 parts by volume in total of the low-boiling-point solvent (f-1) and the high-boiling-point solvent (f-2) in the photosensitive paste. By setting the content of the low boiling point solvent (f-1) to 25 parts by volume or more, the residual amount of the solvent (F) after drying can be reduced, and adhesion during low-temperature drying and adhesion in the dicing step can be further suppressed. The content of the low boiling point solvent (f-1) is more preferably 35 parts by volume or more. On the other hand, by setting the content of the low boiling point solvent (f-1) to 65 parts by volume or less, the increase in viscosity due to excessive volatilization of the solvent (F) during continuous printing in the coating process can be suppressed and continuous printability can be improved. have. The content of the low boiling point solvent (f-1) is more preferably 55 parts by volume or less.

The photosensitive conductive paste of the present invention may contain a reactive compound having a viscosity at 60°C of less than 5.0 Pa·s or more than 100.0 Pa·s in addition to the reactive compound (C) as long as it does not interfere with the effect of the present invention. I can. Examples of the reactive compound having a viscosity at 60°C of less than 5.0 Pa·s or more than 100.0 Pa·s include allylated cyclohexyl diacrylate, 1,4-butanediol diacrylate, and 1,3-butylene. Glycol diacrylate, ethylene glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, polyethylene glycol diacrylate, dipentaerythritol hexaacrylate, dipentaerythritol monohydroxypentaacrylate, ditrimethyl Allpropane tetraacrylate, glycerol diacrylate, methoxylated cyclohexyl diacrylate, neopentyl glycol diacrylate, propylene glycol diacrylate, polypropylene glycol diacrylate, triglycerol diacrylate, trimethylolpropane triacrylic Acrylate, bisphenol A diacrylate, isocyanuric acid EO-modified triacrylate, epoxy acrylate, acrylic acid esters such as urethane acrylate, those obtained by changing these acrylates to methacrylate, "IMILEX (registered trademark)" P (N-phenylmaleimide), "IMILEX" C (N-cyclohexylmaleimide) (above, brand name, manufactured by NIPPON SHOKUBAI CO., LTD.), BMI-1000 (4,4-diphenylmethane bismaleimide) , BMI-2000 (phenylmethane maleimide), BMI-4000 (bisphenol A diphenyl ether bismaleimide), BMI-7000 (4-methyl-1,3-phenylene bismaleimide) (above, brand name, Daiwa Kasei Maleimide compounds, such as Industry Co., Ltd. product), etc. are mentioned. You may contain 2 or more types of these. Among these, it is preferable to contain N-phenylmaleimide from the viewpoint of more suppressing adhesion in the dicing step. The photosensitive conductive paste of the present invention may contain additives such as a plasticizer, a leveling agent, a sensitizer, a dispersing agent, a silane coupling agent, an antifoaming agent, and a pigment within the range that does not impair desired properties.

As a plasticizer, dibutyl phthalate, dioctyl phthalate, polyethylene glycol, glycerin, etc. are mentioned, for example. You may contain 2 or more types of these.

As a leveling agent, for example, "BYK (registered trademark)" -300, 310, 320, 322, 323, 324, 325, 330, 331, 344, 370, 371, 354, 358, 361 (above, BYK-Chemie GmbH), "DISPARLON (registered trademark)" L-1980N, L-1980-50, L-1982-50, L-1983-50, L-1984-50, L-1985-50, #1970, #230 , LC-900, LC-951, #1920N, #1925N, P-410 (above, manufactured by Kusumoto Chemicals, Ltd.), and the like. You may contain 2 or more types of these.

As a sensitizer, for example, 2,4-diethyl thioxanthone, isopropyl thioxanthone, 2,3-bis(4-diethylaminobenzal)cyclopentanone, 2,6-bis(4-dimethylamino Benzal)cyclohexanone, 2,6-bis(4-dimethylaminobenzal)-4-methylcyclohexanone, Michler's ketone, 4,4-bis(diethylamino)benzophenone, 4,4-bis(dimethyl Amino) chalcone, 4,4-bis (diethylamino) chalcone, p-dimethylamino cinnamylidene indanone, and the like. You may contain 2 or more types of these.

As a dispersing agent, for example, FLOWLEN G-100SF, G-500, G-700, G-700 (above, manufactured by Kyoeisha Chemical Co., Ltd.), "NOPCOSPERSE (registered trademark)" 092, SN DISPERSANT 9228, SN SPARSE 2190 (above, made by SAN NOPCO LIMITED), etc. are mentioned. You may contain 2 or more types of these.

The photosensitive conductive paste of the present invention can be obtained, for example, by dissolving and/or dispersing the components (A) to (D) described above, the component (E) and other additives in a solvent, if necessary. As a dissolving and/or dispersing device, a dispersing machine such as a triple roller and a ball mill, a kneading machine, and the like can be mentioned.

Next, the cured product of the present invention will be described. The cured product of the present invention is formed by curing the photosensitive conductive paste of the present invention, and its shape is irrelevant. The thickness of the cured product is preferably 5 to 30 μm. Volume resistivity can be reduced by making the thickness of the cured product 5 µm or more. On the other hand, by setting the thickness of the cured product to 30 µm or less, peeling in the exposure/development step described later can be suppressed, and a more detailed pattern can be easily formed.

The cured product of the present invention may have a predetermined pattern shape. As a pattern shape, a linear shape, a vortex shape, etc. are mentioned, for example. The minimum width for the pattern shape is preferably 10 to 30 μm. Volume resistivity can be reduced by setting the pattern width to 10 µm or more. On the other hand, by setting the pattern width to 30 µm or less, a more detailed pattern can be easily formed.

The cured product of the present invention can be obtained, for example, by applying the photosensitive conductive paste of the present invention on a substrate, drying it, and photocuring by exposure. When manufacturing a pattern-shaped cured product, a pattern may be formed by developing after pattern exposure.

Examples of the coating method in the coating step include spray coating, roll coating, screen printing, a blade coater, a die coater, a calender coater, a meniscus coater, a bar coater, and the like. The film thickness of the coating film can be appropriately selected according to the coating method, the solid content concentration or viscosity of the photosensitive conductive paste.

Examples of the drying method include heat drying using a heating device such as an oven, a hot plate, and infrared rays, or vacuum drying. The heating temperature is preferably 60 to 120°C. By setting the drying temperature to 60°C or higher, the solvent can be efficiently removed by volatilization. On the other hand, by setting the drying temperature to 120°C or less, thermal crosslinking of the photosensitive conductive paste is suppressed, and residues of the non-exposed portion in the exposure/development step described later are reduced, so that a more detailed pattern can be easily formed. The heating time is preferably 5 minutes to several hours.

Exposure methods include exposure through a photomask, exposure without using a photomask, and exposure methods without using a photomask include full-face exposure, direct drawing using laser light, etc. I can. As an exposure apparatus, a stepper exposure machine, a proximity exposure machine, etc. are mentioned, for example. Examples of the active light to be exposed include near ultraviolet rays, ultraviolet rays, electron rays, X-rays, laser light, and the like, and ultraviolet rays are preferable. Examples of the ultraviolet light source include a low-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a halogen lamp, and a sterilization lamp, and an ultra-high pressure mercury lamp is preferable.

As a developer for alkali development, for example, tetramethylammonium hydroxide, diethanolamine, diethylaminoethanol, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, triethylamine, diethylamine, methylamine, dimethylamine And aqueous solutions such as dimethylaminoethyl acetate, dimethylaminoethanol, dimethylaminoethyl methacrylate, cyclohexylamine, ethylenediamine, and hexamethylenediamine. Polar solvents such as N-methyl-2-pyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, and γ-butyrolactone to these aqueous solutions; Alcohols such as methanol, ethanol, and isopropanol; Esters such as ethyl lactate and propylene glycol monomethyl ether acetate; Cyclopentanone, cyclohexanone, isobutyl ketone; Ketones such as methyl isobutyl ketone; You may add surfactant or the like.

As a developing method, for example, a method of spraying a developer onto the dried film after exposure while still standing or rotating the substrate on which the dried film was formed, a method of immersing the substrate on which the dried film after exposure was formed in a developer, and a substrate on which the dried film after exposure was formed. And a method of applying ultrasonic waves while being immersed in a developer.

The cured product obtained by development may be subjected to a rinse treatment with a rinse solution. As the rinse liquid, for example, water; Aqueous solutions of alcohols such as ethanol and isopropyl alcohol; And aqueous solutions of esters such as ethyl lactate and propylene glycol monomethyl ether acetate.

The cured product of the present invention can also be laminated to form a laminate. The number of layers is preferably 1 to 30 layers. By setting the number of layers to one or more layers, the thickness of the predetermined pattern can be increased. On the other hand, by setting the number of layers to 30 or less, the influence of the alignment misalignment between layers can be reduced.

Next, the fired body of the present invention will be described. The fired body of the present invention is obtained by firing the photosensitive conductor paste of the present invention, and its shape is irrelevant. The thickness of the fired body is preferably 2 to 20 μm. By making the thickness of the fired body 2 µm or more, disconnection during firing can be suppressed. On the other hand, by setting the thickness of the fired body to 20 µm or less, expansion during firing can be further suppressed.

The line width of the fired body of the present invention is preferably 5 to 20 µm. Disconnection during firing can be suppressed by making the line width of the fired body 5 µm or more. On the other hand, by setting the line width of the fired body to 20 µm or less, a more detailed pattern can be easily formed.

The fired body of the present invention can be obtained, for example, by firing the cured product of the present invention or a laminate thereof described above. As the firing method, for example, after heat treatment at 300 to 600°C for 5 minutes to several hours, further heat treatment at 850 to 900°C for 5 minutes to several hours, or the like may be mentioned.

Next, the manufacturing method of the patterned green sheet of this invention is demonstrated. It is preferable to have a coating process of applying the photosensitive conductive paste of the present invention on a green sheet to obtain a coating film, a drying process of drying the coating film to obtain a dried film, and an exposure/development process of exposing and developing the dried film to obtain a pattern. .

It is preferable that the green sheet contains insulating ceramic powder, a binder resin, and a plasticizer. Examples of the insulating ceramic powder include "PARSERUM (registered trademark)" BT149 (product name; manufactured by Nippon Chemical Industrial Co., Ltd.), SG-200 (product name; manufactured by NIPPON TALC Co., Ltd.), and the like. . You may contain 2 or more types of these. As a binder resin, an acrylic resin, a polyvinyl butyral resin, a polyvinyl alcohol resin, a cellulose resin, a methylcellulose resin, etc. are mentioned, for example. You may contain 2 or more types of these. The difference between the SP value of the binder resin and the SP value of the reactive compound (C) in the photosensitive conductive paste is preferably 1.0 to 8.6 (J/cm 3) ^1/2 . When the difference in the SP value is 1.0 (J/cm 3) ^1/2 or more, absorption of the reactive compound (C) into the green sheet can be further suppressed, and a finer pattern can be easily formed. On the other hand, by setting the difference in the SP value to 8.6 (J/cm 3) ^1/2 or less, the adhesion of the photosensitive conductive paste to the green sheet can be improved, and a more fine pattern can be easily formed. The difference between the SP value of the binder resin and the SP value of the reactive compound (C) in the photosensitive conductive paste is more preferably 5.0 (J/cm 3) ^1/2 or less.

As the coating method in the coating step, the method exemplified as the coating method in the manufacturing method of the cured product described above can be mentioned. The film thickness of the coating film can be appropriately selected according to the application method, the solid content concentration or viscosity of the photosensitive conductive paste, and the like, and it is preferable to set the film thickness of the dried film in the drying step described later to be 5 to 30 µm. In addition, the film thickness of the dried film can be measured using a stylus-type step gauge (for example, "SURFCOM (registered trademark)" 1400; manufactured by TOKYO SEIMITSU CO., LTD.). More specifically, the film thickness at three randomly selected positions can be determined by measuring each with a stylus type step gauge (measurement length: 1 mm, scanning speed: 0.3 mm/s), and calculating their average values.

As a drying method in a drying process, the method exemplified as a drying method in the manufacturing method of the hardened|cured material mentioned above is mentioned.

As the exposure method in the exposure/development process, the method exemplified as the exposure method in the method for producing the cured product described above can be mentioned.

A desired pattern can be formed by developing the dried film after exposure using a developer and dissolving and removing the non-exposed part. As a developer, what was illustrated as a developer in the manufacturing method of the hardened|cured material mentioned above is mentioned.

As a developing method, for example, a method of spraying a developer onto a dried film after exposure while still standing or rotating a green sheet, a method of immersing a green sheet having a dried film after exposure into a developer, and a green sheet having a dried film after exposure are immersed in the developer. While applying ultrasonic waves.

The pattern obtained by development may be subjected to a rinse treatment with a rinse solution. Examples of the rinse liquid include those exemplified as the rinse liquid in the method for producing the cured product described above.

The obtained patterned green sheet may be laminated to form a laminate.

It is preferable to fire the obtained patterned green sheet to form a fired body. As the firing method, the method exemplified as the firing method in the method for producing a fired body can be mentioned. The pattern formed on the green sheet is a composite of a cured product of an organic component including a conductive powder (A), an alkali-soluble resin (B), a reactive compound (C), and a photopolymerization initiator (D), and the conductive powder (A ) Conductivity is expressed by contacting each other. Such a conductive pattern can be suitably used as an internal wiring for an electronic component or the like.

The cured product of the present invention, the fired body, and the patterned green sheet obtained by the manufacturing method of the patterned green sheet of the present invention can be preferably used for electronic parts.

It is preferable that the electronic component of the present invention has a fired body, an insulating ceramic layer, and a terminal electrode. As the fired body, the fired body of the present invention described above is preferred, and the fired body and the insulating ceramic layer are preferably formed by firing the patterned green sheet obtained by the above-described manufacturing method. By having an insulating ceramic layer, it is possible to suppress an unintended short circuit between the fired bodies. The terminal electrode is preferably provided outside the sintered body and the insulating ceramic layer. Examples of the material constituting the terminal electrode include nickel or tin.

The electronic component manufacturing method of the present invention includes a lamination step of obtaining a plurality of patterned green sheets by the above-described method, laminating and thermocompressing them to obtain a laminate, and a firing step of firing the laminate to obtain an electronic component. It is desirable. As an example of the method of manufacturing the electronic component of the present invention, a method of manufacturing a multilayer chip inductor is described below.

First, a via hole is formed in a green sheet, and a conductor is embedded in the via hole to form an interlayer connection wiring. As a via hole formation method, laser irradiation etc. are mentioned, for example. As a method of filling the via hole with a conductor, for example, a method of filling a conductor paste and drying it by a screen printing method. As a conductor paste, a paste containing copper, silver, and a silver-palladium alloy is mentioned, for example. The photosensitive conductive paste of the present invention described above is preferable in that the process can be simplified by forming the interlayer connection wiring and the internal wiring at once.

Internal wiring is formed on the green sheet on which the interlayer connection wiring is formed. As a method for forming the internal wiring, for example, a photolithographic method using a photosensitive conductive paste may be mentioned. As the photosensitive conductive paste, the photosensitive conductive paste of the present invention described above can be preferably used because a high-definition pattern can be easily formed. If necessary, a dielectric pattern or an insulator pattern is additionally formed. As a method of forming a dielectric pattern and an insulator pattern, for example, a screen printing method or the like can be mentioned.

Next, a plurality of green sheets with interlayer connection wiring and internal wiring are stacked and thermally compressed to obtain a laminate. As the lamination method, for example, a method of superimposing green sheets using guide holes, etc. may be mentioned. As a thermocompression bonding device, a hydraulic press machine etc. are mentioned, for example. The thermocompression bonding temperature is preferably 90 to 130°C, and the thermocompression pressure is preferably 5 to 20 MPa.

A multilayer chip inductor can be obtained by cutting the obtained laminate into a desired chip size, firing, applying a terminal electrode, and performing a plating treatment. As a cutting device, a die cutter etc. are mentioned, for example. As the firing method, for example, after heat treatment at 300 to 600°C for 5 minutes to several hours, further heat treatment at 850 to 900°C for 5 minutes to several hours, or the like may be mentioned. As a method of applying the terminal electrode, a sputtering method or the like is mentioned, for example. As the metal used for the plating treatment, nickel, tin, etc. are mentioned, for example.

(Example)

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

<Material of photosensitive conductive paste>

The raw materials used are as follows.

Conductive powder (A)

Conductive powder (A-1): Ag powder with D50 of 2.5 μm

Conductive powder (A-2): Ag powder with D50 of 0.3 μm

Conductive powder (A-3): Ag powder having a D50 of 0.8 μm

Conductive powder (A-4): Ag powder having a D50 of 4.2 μm

Conductive powder (A-5): Ag powder with D50 of 5.3 μm

Further, D50 of the conductive powder 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.).

Alkali Soluble Resin (B)

Alkali-soluble resin (b-1a): methacrylic acid / methyl methacrylate / styrene = 54/23/23 (molar ratio) to 100 mole parts of the carboxyl group of the copolymer, 40 mole parts of glycidyl methacrylate was added Acrylic resin (Mw 30,000, glass transition point 110℃, acid value 100mgKOH/g)

Alkali-soluble resin (b-1b): "ARUFON (registered trademark)" UC-3910 (acrylic resin, Mw 8,500, glass transition point 85°C, acid value 200 mgKOH/g; manufactured by TOAGOSEI CO., LTD.)

Alkali-soluble resin (b-1c): "ART CURE (registered trademark)" RA-3953MP (acrylic resin, Mw 40,000, glass transition point 139°C, acid value 60 mgKOH/g: manufactured by Negami Chemical Industrial Co., Ltd.)

Alkali-soluble resin (b-1d): "ARUFON" UC-3000 (acrylic resin, Mw 10,000, glass transition point 65°C, acid value 74 mgKOH/g; manufactured by TOAGOSEI CO., LTD.)

Alkali-soluble resin (b-1e): "ART CURE" RA-4101 (acrylic resin, Mw 40,000, glass transition point 190°C, acid value 90 mgKOH/g; manufactured by Negami Chemical Industrial Co., Ltd.)

Alkali-soluble resin (b-1f): methacrylic acid / methyl methacrylate / styrene = 50/25/25 (molar ratio) 50/25/25 (molar ratio) Acrylic resin (Mw 22,000, glass transition point 110℃, acid value 60mgKOH/g)

Alkali-soluble resin (b-1g): methacrylic acid / methyl methacrylate / styrene = 60/20/20 (molar ratio) 45 mole parts of glycidyl methacrylate with respect to 100 mole parts of the carboxyl group of the copolymer Acrylic resin (Mw 40,000, glass transition point 110℃, acid value 100mgKOH/g)

Alkali-soluble resin (b-2a): acrylic resin copolymerized with methacrylic acid/methyl methacrylate/styrene = 54/23/23 (molar ratio) (Mw 40,000, glass transition point 140°C, acid value 250 mgKOH/g)

Alkali-soluble resin (b-1h): "CYCLOMER (registered trademark)" P(ACA)Z250 (acrylic resin, Mw 22,000, glass transition point 136°C, acid value 60 mgKOH/g)

Alkali-soluble resin (b-2b): acrylic resin copolymerized with methacrylic acid/methyl methacrylate/styrene = 50/27/23 (molar ratio) (Mw 40,000, glass transition point 133°C, acid value 220 mgKOH/g)

Alkali-soluble resin (b-2c): acrylic resin copolymerized with methacrylic acid/methyl methacrylate/styrene = 58/19/23 (molar ratio) (Mw 40,000, glass transition point 146°C, acid value 280 mgKOH/g)

Alkali-soluble resin (b-2d): acrylic resin copolymerized with methacrylic acid/methyl methacrylate/styrene = 47/30/23 (molar ratio) (Mw 40,000, glass transition point 130°C, acid value 205 mgKOH/g)

Alkali-soluble resin (b-2e): acrylic resin copolymerized with methacrylic acid/methyl methacrylate/styrene = 62/19/19 (molar ratio) (Mw 40,000, glass transition point 152°C, acid value 300 mgKOH/g)

Alkali-soluble resin (b-2f): acrylic resin copolymerized with methacrylic acid/methyl methacrylate/styrene = 54/20/26 (molar ratio) (Mw 32,000, glass transition point 140°C, acid value 250 mgKOH/g)

Alkali-soluble resin (b-2g): acrylic resin copolymerized with methacrylic acid/methyl methacrylate/styrene = 54/26/20 (molar ratio) (Mw 42,000, glass transition point 140°C, acid value 250 mgKOH/g)

Alkali-soluble resin (b-2h): acrylic resin copolymerized with methacrylic acid/methyl methacrylate/styrene = 54/16/30 (molar ratio) (Mw 22,000, glass transition point 140°C, acid value 250 mgKOH/g)

Alkali-soluble resin (b-2i): acrylic resin copolymerized with methacrylic acid/methyl methacrylate/styrene = 54/30/16 (molar ratio) (Mw 46,000, glass transition point 140°C, acid value 250 mgKOH/g)

Alkali-soluble resin (b-2j): acrylic resin copolymerized with methacrylic acid/methyl methacrylate/styrene = 54/6/46 (molar ratio) (Mw 16,000, glass transition point 140°C, acid value 250 mgKOH/g)

Alkali-soluble resin (b-2k): acrylic resin copolymerized with methacrylic acid/methyl methacrylate/styrene = 54/40/6 (molar ratio) (Mw 66,000, glass transition point 140°C, acid value 250 mgKOH/g)

Alkali-soluble resin (b-1i): acrylic resin copolymerized with methacrylic acid/methyl methacrylate/styrene = 30/35/35 (molar ratio) (Mw 40,000, glass transition point 110°C, acid value 100 mgKOH/g)

Alkali-soluble resin (b-1j): acrylic resin copolymerized with methacrylic acid/methyl methacrylate/styrene = 85/8/7 (molar ratio) (Mw 40,000, glass transition point 160°C, acid value 400 mgKOH/g)

In addition, the weight average molecular weight Mw of an alkali-soluble resin was set as the polystyrene conversion value measured by high performance liquid chromatography (Alliance 2695; Nihon Waters K.K. product). In addition, the glass transition point of the alkali-soluble resin was measured using a differential scanning calorimeter (DSC-50; SHIMADZU CORPORATION).

Reactive compound (C), (C')

Reactive compound (C-1): NK oligo UA-122P (ester structure-containing urethane acrylate, viscosity at 60° C. 7.0 Pa·s, weight average molecular weight 1,100, SP value 27.1 (J/cm 3) ^1/2 ; SHIN -NAKAMURA CHEMICAL CO, LTD.)

Reactive compound (C-2): "KAYARAD" UX-3204 (ester structure-containing urethane acrylate, viscosity at 60° C. 16.0 Pa·s, weight average molecular weight 13,000, SP value 25.2 (J/cm 3) ^1/2 ; Nippon Kayaku Co., Ltd.)

Reactive compound (C-3): "KAYARAD" UXF-4002 (ester structure-free urethane acrylate, viscosity at 60° C. 26.0 Pa·s, weight average molecular weight 12,000, SP value 24.4 (J/cm 3) ^1/2 ; Nippon Kayaku Co., Ltd. product)

Reactive compound (C-4): "KAYARAD" UX-4101 (ester structure-containing urethane acrylate, viscosity at 60° C. 40.0 Pa·s, weight average molecular weight 6,500, SP value 25.2 (J/cm 3) ^1/2 ; Nippon Kayaku Co., Ltd.)

Reactive compound (C-5): "SARTOMER" CN966 (ester structure-containing urethane acrylate, viscosity at 60° C. 70.0 Pa·s, weight average molecular weight 3,000, SP value 28.1 (J/cm 3) ^1/2 ; ARKEMA KK My)

Reactive compound (C'-6): "SARTOMER" CN9178 (ester structure-containing urethane acrylate, viscosity at 60° C. 2.0 Pa·s, weight average molecular weight 1,000, SP value 28.1 (J/cm 3) ^1/2 ; ARKEMA KK)

Reactive compound (C'-7): "SARTOMER" CN8882NS (ester structure-containing urethane acrylate, viscosity at 60° C. 105.0 Pa·s, weight average molecular weight 4,000, SP value 28.1 (J/cm 3) ^1/2 ; ARKEMA KK)

Reactive compound (C-8): "KAYARAD" UX-8101 (ester structure-containing urethane acrylate, viscosity at 60°C of 28.0 Pa·s, weight average molecular weight of 3,000, SP value of 24.8 (J/cm 3) ^1/2 ; Nippon Kayaku Co., Ltd.)

Preparation Example 1: Reactive compound (C-9)

1000 mol parts of KURARAY POLYOL P-1010 (polycarbonate diol, manufactured by KURARAY CO., LTD.) and 1400 mol parts of isophorone diisocyanate were reacted at 70°C for 6 hours, and then 4HBA (4-hydroxybutyl acrylate, Mitsubishi Chemical Holdings Corporation) Article) 1000 molar parts, 0.1 molar parts of 4-methoxyphenol, and 0.006 molar parts of dibutyltin dilaurate were added and reacted for an additional 2 hours to obtain a reactive compound (C-9). The obtained reactive compound was a urethane acrylate containing an ester structure, and the viscosity at 60°C was 18.0 Pa·s. The weight average molecular weight was 21,000. In addition, the SP value was 23.0 (J/cm 3) ^1/2 .

Preparation Example 2: Reactive Compound (C-10)

Reactive compound (C-10) was obtained by reacting under the same conditions as in Production Example 1 except that the amount of isophorone diisocyanate was changed to 1500 molar parts (ester structure-containing urethane acrylate, viscosity at 60° C. 32.0 Pa·s, Weight average molecular weight 29,000, SP value 23.0 (J/cm 3) ^1/2 ).

Preparation Example 3: Reactive Compound (C-11)

Reactive compound (C-11) was obtained by reacting under the same conditions as in Production Example 2 except that KURARAY POLYOL P-1010 was changed to KURARAY POLYOL P-3010 (ester structure-containing urethane acrylate, viscosity at 60° C. 40.0 Pa s, weight average molecular weight 38,000, SP value 23.0 (J/cm 3) ^1/2 ).

Preparation Example 4: Reactive Compound (C-12)

Reactive compound (C-12) was obtained by reacting under the same conditions as in Production Example 2, except that KURARAY POLYOL P-1010 was changed to KURARAY POLYOL P-5010 (ester structure-containing urethane acrylate, viscosity at 60° C. 45.0 Pa s, weight average molecular weight 42,000, SP value 23.0 (J/cm 3) ^1/2 ).

Preparation Example 5: Reactive compound (C'-13)

20 parts by weight of pentaerythritol tetra (mercaptoacetate), 138 parts by weight of dipentaerythritol hexaacrylate, 74 parts by weight of dipentaerythritol pentaacrylate, 0.10 parts by weight of hydroquinone, and 0.02 parts by weight of benzyldimethylamine were added to 12 at 60°C. The reaction was carried out for a period of time to obtain a reactive compound (C'-13) (ester structure-containing acrylate, viscosity at 60°C of 4.0 Pa·s, weight average molecular weight 33,000, SP value 22.7 (J/cm 3) ^1/2 ).

Reactive compound (C'-14): "ARONIX (registered trademark)" M-1200 (urethane acrylate, viscosity at 60°C 105.0 Pa·s, weight average molecular weight 3,000, SP value 26.2 (J/cm 3) ^{1/ 2} )

Reactive compound (C'-15): "ARONIX (registered trademark)" M-402 (dipentaerythritol penta and hexaacrylate (ester structure-containing acrylate, viscosity at 60° C. 1.0 Pa·s, weight average molecular weight 570) , SP value 22.7 (J/cm 3) ^1/2 )

In addition, the viscosity of the reactive compound is a B-type viscometer (Brookfield viscometer, type HB DV-I; manufactured by EKO INSTRUMENTS CO., LTD.) under atmospheric pressure after temperature-controlling the reactive compound for 3 minutes using a 60°C thermostat. It measured in rotation speed 3rpm using. The weight average molecular weight of the reactive compound was determined in terms of polystyrene measured by high performance liquid chromatography (Alliance 2695; manufactured by Nihon Waters K.K.). In addition, the SP value of the reactive compound was calculated from the molecular structure using Fedors' calculation method.

Photoinitiator (D)

Photopolymerization initiator (D): ADEKA OPTOMER N-1919 (oxime type photopolymerization initiator; ADEKA CORPORATION product).

Particulate (E)

Fine particles (E-1): "AEROSIL" 200 (volume average particle diameter 12 nm, hydrophilic silica; manufactured by Nippon Aerosil Co., Ltd.)

Fine particles (E-2): "AEROXIDE" AluC (volume average particle diameter 13 nm, hydrophilic alumina; manufactured by Nippon Aerosil Co., Ltd.)

Fine particles (E-3): "AEROSIL" R972 (volume average particle diameter 12 nm, hydrophobic silica; manufactured by Nippon Aerosil Co., Ltd.)

Fine particles (E-4): "AEROSIL" OX50 (volume average particle diameter 40 nm, hydrophilic silica; manufactured by Nippon Aerosil Co., Ltd.)

Fine particles (E-5): "SEAHOSTAR" KE-S10 (volume average particle diameter 100 nm, hydrophilic silica; manufactured by NIPPON SHOKUBAI CO., LTD.)

In addition, the volume average particle diameter of the fine particles was measured by a dynamic light scattering method using Nanotrac Wave II-UZ251 (manufactured by MicrotracBEL Corp.) after adding the fine particles to water and performing ultrasonic treatment for 300 seconds.

Leveling agent: "DISPARLON (registered trademark)" L-1980N (manufactured by Kusumoto Chemicals, Ltd.).

Dispersant: FLOWLENG-700 (manufactured by Kyoeisha Chemical Co., Ltd.).

Solvent (F), (F')

Solvent (f-2a): "CELTOL (registered trademark)" DPNB (dipropylene glycol n-butyl ether, boiling point 230°C, SP value 20.9 (J/cm 3) ^1/2 ; manufactured by Daicel Corporation)

Solvent (f-1a): "CELTOL" CHXA (cyclohexanol acetate, boiling point 173°C, SP value 19.5 (J/cm 3) ^1/2 ; manufactured by Daicel Corporation)

Solvent (f'-2b): "BUTYSENOL (registered trademark)" 20 (diethylene glycol monobutyl ether, boiling point 230°C, SP value 21.5 (J/cm 3) ^1/2 ; manufactured by KH Neochem Co., Ltd.)

Solvent (f'-2c): "CELTOL" DPMA (dipropylene glycol monomethyl ether acetate, boiling point 213°C, SP value 18.5 (J/cm 3) ^1/2 ; manufactured by Daicel Corporation)

Solvent (f'-1b): "Acosolve" DPM (dipropylene glycol methyl ether, boiling point 190°C, SP value 21.9 (J/cm 3) ^1/2 )

The SP value of the solvent was calculated from the molecular structure using Fedors' calculation method.

<Production of ceramic green sheet>

(Production Example 1: Ceramic Green Sheet (S1))

As insulating ceramic powder, "PARSERUM" BT149 (manufactured by Nippon Chemical Industrial Co., Ltd.) 100 parts by volume, polyvinyl butyral resin as binder resin (SP value 19.1 (J/cm 3) ^1/2 ) 240 parts by volume, as plasticizer 80 parts by volume of dibutyl phthalate and 160 parts by volume of ethylene glycol monobutyl ether as a solvent were mixed, and a ceramic green sheet (S1) was produced by the doctor blade method.

(Production Example 2: Ceramic Green Sheet (S2))

A ceramic green sheet (S2) was produced in the same manner as in Production Example 1 except that the polyvinyl butyral resin was changed to an 80% saponified polyvinyl butyral resin (SP value of 23.6 (J/cm 3) ^1/2 ).

(Production Example 3: Ceramic Green Sheet (S3))

A ceramic green sheet (S3) was produced in the same manner as in Production Example 1 except that the polyvinyl butyral resin was changed to a polyvinyl alcohol resin (SP value of 30.8 (J/cm 3) ^1/2 ).

(Production Example 4: Ceramic Green Sheet (S4))

A ceramic green sheet (S4) was produced in the same manner as in Production Example 1 except that the polyvinyl butyral resin was changed to a methyl cellulose resin (SP value 30.5 (J/cm 3) ^1/2 ).

(Production Example 5: Ceramic Green Sheet (S5))

A ceramic green sheet (S5) was produced in the same manner as in Production Example 1 except that the polyvinyl butyral resin was changed to an acrylic resin (SP value of 28.7 (J/cm 3) ^1/2 ).

The evaluation method in each Example and a comparative example is shown below.

<Solubility>

The photosensitive organic component solution obtained by Examples 1 to 106 and Comparative Examples 1 to 5 and stirred at 60° C. for 2 hours was visually observed, and the presence or absence of an undissolved residue was observed. When no undissolved residue was found, the solubility (dissolution time) was evaluated as "2 hours". When a non-dissolved residue was confirmed, the mixture was further stirred at 60° C. for 2 hours and then visually observed, and similarly, the presence or absence of a non-dissolved residue was observed. When no undissolved residue was found, the solubility (dissolution time) was evaluated as "4 hours". The shorter the dissolution time, the higher the solubility and productivity can be improved.

<High-definition pattern formation>

Two green sheets each having a dried film obtained in Examples 1 to 111 and Comparative Examples 1 to 5 were prepared, and the line width/space width (hereinafter, ``L/S'') of the coil-shaped pattern on the dried film was 20 Two types of exposure masks of µm/20 µm and 15 µm/15 µm were each interposed, and exposure of 400 mJ/cm 2 of irradiation amount (in terms of wavelength 365 nm) was performed with an ultra-high pressure mercury lamp having an output of 21 mW/cm 2, respectively.

Thereafter, a 0.1% by mass aqueous sodium carbonate solution was shower-developed as a developer until the time when all the non-exposed portions were dissolved (hereinafter, "total dissolution time") to prepare two types of patterned sheets having different L/S.

Two types of pattern formation sheets having different L/S were observed magnifying at 10 times magnification using an optical microscope, respectively, and evaluated according to the following criteria from the presence or absence of breaks and shorts of patterns, filling between patterns, and residues.

No breaks, shorts, and fillings between patterns and residues are found: ○

Breaks and shorts in the pattern are identified: peeling

Filling/residue between patterns is identified: residue

With respect to the pattern of L/S=20 µm/20 µm, the same operation was repeated and similarly evaluated except that the time of shower development was extended to 1.1 times, 1.2 times, 1.3 times, and 1.4 times the total dissolution time. In addition, with respect to the pattern of L/S = 15 µm/15 µm, the same operation was repeated and similarly evaluated except that the time for shower development was extended to 1.1 times and 1.2 times the total dissolution time. In addition, the evaluation up to the above was developed within 30 minutes after drying.

In addition, several dry films having changed the time left to stand after drying were prepared, a pattern of L/S=15 µm/15 µm was formed, and the time for shower development was 1.1 times the total dissolution time, and evaluated according to the above criteria. The settling time was recorded after drying, which enables pattern formation without peeling or residue.

Productivity is improved by suppressing the occurrence of defects in development as no residue is found in the total dissolution time, and as no peeling is observed in a longer development time, and as the residue or peeling is not observed even if the standing time after drying is long. I can make it. As the L/S small pattern can be formed, a high-definition pattern can be formed and productivity can be improved.

<Firing defect>

L/S of 20 µm/20 µm and 15 µm/15 by the method described in the above-described <high-definition pattern formation> using the green sheet on which the dried film obtained in Examples 1 to 111 and Comparative Examples 1 to 5 was formed. Ten pattern formation sheets each using a µm exposure mask were prepared. Ten of these patterned sheets were stacked using a guide hole, and pressed under conditions of a temperature of 90°C and a pressure of 15 MPa using a hydraulic press to produce a 10-layer laminated sheet.

The obtained 10-layer laminated sheet was cut into a size of 0.3mm×0.6mm×0.3mm using a die cutter, heat-treated at 350°C for 10 hours, and then heat-treated at 880°C for 10 minutes and fired to obtain a 10-layered fired sheet. Manufactured.

The cross section of the laminated fired sheet was enlarged and observed at 500 times magnification using a scanning electron microscope (S2400; manufactured by Hitachi, Ltd.), and evaluated according to the following criteria.

No defects such as cracks were found in the layer: ○

Disconnection defects such as cracks in the layer are identified: disconnection

Expansion between the layers is identified: expansion

If disconnection or expansion is not observed after firing, it is possible to suppress the occurrence of defects during firing when used as an electronic component, thereby improving productivity.

In addition, the photosensitive conductive paste of the present invention can be processed by <high-definition pattern formation> in a pattern of L/S=20 μm/20 μm, and it is necessary that there is no disconnection or expansion after firing due to <fire defect>.

<Volume resistivity>

The photosensitive conductive paste obtained by Examples 1 to 106 and Comparative Examples 1 to 5 was applied on an alumina substrate (100 mm×100 mm×thickness 0.5 mm) by screen printing so that the film thickness became 10 μm after drying. The coating film was dried in a hot air dryer at 80° C. for 10 minutes to obtain a dried film. Except for using an exposure mask of a predetermined pattern (a pattern with a length of 5 cm x a line width of 1 mm and a pad of 1 cm x 1 cm at both ends), exposure and development are performed in the same manner as described in the above-described <high-definition pattern formation>. A pattern formation sheet for resistance measurement was obtained. The obtained pattern formation sheet for resistance measurement was heat-treated at 880°C for 10 minutes and fired to obtain a patterned fired body for resistance measurement. The obtained patterned fired body for resistance measurement was observed with a scanning electron microscope (S2400; manufactured by Hitachi, Ltd.) magnified at a magnification of 2000, and the line width and film thickness of the fired body were measured. Further, the resistance value of the pattern fired body for resistance measurement was measured using a digital multimeter (CDM-16D; manufactured by CUSTOM Corporation), and the volume resistivity was calculated from the following equation.

Volume resistivity (μΩ·cm) = Actual resistance value (Ω) × 1000 × Pattern line width (cm) × Pattern thickness (cm) ÷ Pattern length (cm)

The smaller the volume resistivity, the better the electrical properties when used for electronic components.

<Low temperature drying>

The photosensitive conductive paste obtained by each Example and Comparative Example was dried on a PET film (S10 "LUMIRROR (registered trademark)" #125; manufactured by Toray Industries, Inc.) by screen printing so that the film thickness became 12 µm. A plurality of sheets were applied, and dried for 10 minutes in a hot air dryer at 55°C, 60°C, 65°C, 70°C, and 75°C to obtain a dried film on a PET film. The application surface of these dried films was promoted to check the presence or absence of adhesion, and the lowest drying temperature at which adhesion was not observed was recorded. In this evaluation, the more the adhesion on the surface of the coating film is not confirmed under the drying conditions at a lower temperature, the more the adhesion is suppressed, and the productivity can be improved.

<Adhesion in the dicing process>

The dried film at the lowest dry temperature obtained in each of the Examples and Comparative Examples obtained in the above low-temperature drying property evaluation was cut into strips each having a width of 1 cm, and a 50 g stainless steel plate was placed from the top by overlapping the coated surfaces. In that state, it heated for 1 minute in a hot air dryer heated to 80 degreeC, 85 degreeC, 90 degreeC, 95 degreeC, and 100 degreeC. Thereafter, the surface of the coating film was visually observed, and the highest temperature at which adhesion was not observed was recorded.

In this evaluation, as the adhesion on the surface of the coating film is not confirmed under higher temperature conditions, the adhesion is suppressed, and the adhesion in the dicing step can be suppressed, thereby improving productivity.

<Continuous printability>

The photosensitive conductive paste obtained by each Example and Comparative Example on a PET film (S10 "LUMIRROR (registered trademark)" #125; manufactured by Toray Industries, Inc.) was temperature-controlled for 3 minutes using a thermostat at 25°C and then atmospheric pressure Under the conditions, the viscosity was measured at a rotational speed of 10 rpm using a B-type viscometer (Brookfield viscometer, model HB DV-I; manufactured by EKO INSTRUMENTS CO., LTD.).

Applying the photosensitive conductive paste obtained by each Example and Comparative Example by a screen printing method was repeated, and the paste after printing 100 times, 200 times, and 500 times was collected. For each paste, the viscosity was measured by the above method, and the ratio to the viscosity before printing (viscosity after printing/viscosity before printing) was calculated. In this evaluation, the closer the viscosity ratio is to 1, the better the continuous printability and productivity can be improved.

(Example 1)

Alkali-soluble resin (B), reactive compound (C), photopolymerization initiator (D), leveling agent, dispersant, and solvent (F) were added to a glass flask and stirred at 60° C. for 2 hours to obtain photosensitive organic A component solution was obtained. To this photosensitive organic component solution, conductive powder (A) and fine particles (E) were further added to the composition ratio shown in Table 1, stirred, and then kneaded using three rollers (EXAKT M-50; manufactured by Exakt, Inc.) and photosensitive. Conductive paste P-1 was prepared. Table 11 shows the results of evaluation of the obtained photosensitive conductive paste P-1 by the method described above.

The photosensitive conductive paste P-1 obtained on a green sheet (GCS71F; manufactured by YAMAMURA PHOTONICS CO., LTD.) was applied by screen printing so that the film thickness after drying was 10 µm to obtain a coated film. The obtained coating film was dried for 10 minutes using a hot air dryer at 80°C to form a dried film on the green sheet. The same operation was repeated to prepare a plurality of green sheets on which a dried film was formed.

(Examples 2 to 106, Comparative Examples 1 to 5)

Photosensitive conductive pastes P-2 to P-111 were obtained in the same manner as in Example 1 except that the composition of the photosensitive conductive paste was changed as described in Tables 1 to 10. However, in Examples 22 to 23, since a residue was confirmed in the photosensitive organic component solution after stirring at 60°C for 2 hours, the mixture was stirred at 60°C for 2 hours. Using the obtained photosensitive conductive pastes P-2 to P-111, a green sheet in which a dried film was formed in the same manner as in Example 1 was obtained. The results evaluated by the above-described method are shown in Tables 11 to 22.

(Examples 107 to 111)

In addition to the green sheet (GCS71F), a green sheet in which a photosensitive conductive paste and a dried film were formed was obtained in the same manner as in Example 2 except that the ceramic green sheets S1 to S5 obtained by Production Examples 1 to 5 were used, respectively. Table 23 shows the results evaluated by the above-described method.

(Example 112)

The photosensitive conductive paste P-2 obtained in Example 2 was applied on the green sheet (GCS71F; manufactured by Yamamura PHOTONICS CO., LTD.) on which the via hole was formed to have a thickness of 13 μm after drying by a screen printing method. A coating film was obtained. The obtained coating film was dried for 10 minutes using a hot air dryer at 80° C., and a dried film was formed on the green sheet while filling the conductor with a via hole. The dried film was exposed to an irradiation dose of 400 mJ/cm 2 (in terms of wavelength 365 nm) with an ultra-high pressure mercury lamp having an output of 21 mW/cm 2 through an exposure mask having a coil-shaped pattern L/S of 20/20 μm. Thereafter, a 0.1% by mass aqueous sodium carbonate solution was used as a developer and developed by showering until the total dissolution time to prepare a pattern forming sheet. Twenty of these patterned sheets were prepared, stacked using a guide hole, and pressed under conditions of a temperature of 90°C and a pressure of 15 MPa using a hydraulic press to produce a 20-layer laminated sheet. The obtained 20-layer laminated sheet was cut into a size of 0.3mm×0.6mm×0.3mm using a die cutter, heat-treated at 350°C for 10 hours, and then held at 880°C for 10 minutes and fired to obtain a 20-layer laminated calcined sheet. Manufactured.

The obtained 20-layer laminated fired sheet was coated with a terminal electrode by sputtering, and then plated with nickel and tin to prepare a multilayer chip inductor. With respect to this multilayer chip inductor, copper wiring was connected to both ends of the terminal electrode by soldering, and the conduction was evaluated using a digital multimeter (CDM-16D; manufactured by CUSTOM Corporation), and conduction was conducted without a problem.

(Industrial availability)

The photosensitive conductive paste of the present invention can be suitably used for production of internal wiring patterns such as electronic components.

Claims (19)

Containing conductive powder (A), alkali-soluble resin (B), reactive compound (C), and photopolymerization initiator (D), wherein the reactive compound (C) has a viscosity of 5.0 to 100.0 Pa·s at 60°C. Photosensitive conductive paste. The method of claim 1,
The photosensitive conductive paste in which the reactive compound (C) has a urethane structure. The method according to claim 1 or 2,
The photosensitive conductive paste in which the reactive compound (C) has an ester structure. The method according to any one of claims 1 to 3,
The photosensitive conductive paste in which the weight average molecular weight of the reactive compound (C) is 5000 to 45000. The method according to any one of claims 1 to 4,
The photosensitive conductive paste in which the content of the organic component having a molecular weight of 5000 or less among the organic components of the solid content at 23°C is 4.0 to 15.0% by volume. The method according to any one of claims 1 to 5,
The photosensitive conductive paste in which the weight average molecular weight of an organic component in the solid content at 23 degreeC is 30,000-45,000. The method according to any one of claims 1 to 6,
A photosensitive conductive paste further containing fine particles (E) having a particle diameter of 1 to 100 nm, and having a volume average particle diameter of the fine particles (E) of 1 to 100 nm. The method of claim 7,
A photosensitive conductive paste containing 0.1 to 25.0 parts by volume of the fine particles (E) with respect to 100 parts by volume of the conductive powder (A). The method according to claim 7 or 8,
The photosensitive conductive paste containing at least one selected from the group consisting of titania, alumina, silica, cordierite, mullite, spinel, barium titanate, and zirconia in the fine particles (E). The method according to any one of claims 7 to 9,
The photosensitive conductive paste in which the fine particles (E) are hydrophilic. The method according to any one of claims 1 to 10,
Photosensitive containing 90.0 to 99.1 parts by volume of the alkali-soluble resin (B) and reactive compound (C) in a total of 100 parts by volume of the alkali-soluble resin (B), reactive compound (C), and photopolymerization initiator (D). Conductive paste. The method according to any one of claims 1 to 11,
The photosensitive conductive paste in which the SP value of the reactive compound (C) is 21.5 to 28.7 (J/cm 3) ^1/2 . The method according to any one of claims 1 to 12,
A photosensitive conductive paste further containing a solvent (F) having an SP value of 19.5 to 21.3 (J/cm 3) ^1/2 . A cured product obtained by curing the photosensitive conductive paste according to any one of claims 1 to 13. A fired body obtained by firing the photosensitive conductive paste according to any one of claims 1 to 13. An electronic component comprising the fired body according to claim 15, an insulating ceramic layer, and a terminal electrode. A coating process in which a coating film is obtained by applying the photosensitive conductive paste according to any one of claims 1 to 13 on a green sheet, a drying process in which the coating film is dried to obtain a dried film, and the dried film is exposed and developed to form a pattern. A method for producing a patterned green sheet having an exposure/development step to be obtained. The method of claim 17,
The method for producing a patterned green sheet in which the green sheet contains a binder resin, and the difference between the SP value of the reactive compound (C) and the SP value of the binder in the green sheet is 1.0 to 8.6 (J/cm 3) ^1/2 . A lamination step of obtaining a plurality of patterned green sheets by the method for producing a patterned green sheet according to claim 17 or 18, laminating and thermocompressing them to obtain a laminate, and firing the laminate to obtain an electronic component The electronic component manufacturing method according to claim 16 having a firing step.