KR20240058834A - Photosensitive conductive paste, method of manufacturing a substrate with a conductive pattern, method of manufacturing electronic components, cured film, fired body, and electronic components - Google Patents

Abstract

Contains conductive particles (A), a photosensitive organic component (B), and two or more types of solvents (C), and among the solvents (C), a solvent (C-1) with the lowest boiling point and a solvent with the highest boiling point (C-) 2) The difference in boiling points is 35 to 120°C, the boiling point of the solvent (C-2) is 251 to 300°C, and the solvent (C-2) is 25 to 80% by mass based on 100% by mass of all solvents. Conductive paste.
The increase in viscosity during the application process is suppressed, the tackiness of the dried film is suppressed even when the photosensitive conductive paste is dried at low temperature, and the change over time in the amount of residual solvent contained in the dried film is suppressed.

Description

Photosensitive conductive paste, method of manufacturing a substrate with a conductive pattern, method of manufacturing electronic components, cured film, fired body, and electronic components

The present invention relates to a photosensitive conductive paste, a method for manufacturing a substrate with a conductive pattern, a method for manufacturing electronic components, a cured film, a fired body, and electronic components.

Recently, in response to demands for miniaturization and higher performance, electronic components have had smaller internal wiring and higher aspect ratio ((axial thickness of coil conductor layer)/(coil conductor in a cross section perpendicular to the stretching direction of the coil conductor layer). The width of the layer)) is required. The inductor component includes an insulator made of ceramic and an internal electrode on a coil inside the insulator. The insulator includes a plurality of insulating layers. The internal electrode is formed in the shape of a line wound in a plane on the insulating layer, and a coil is formed by combining them. It has been proposed to use a photosensitive conductive paste (for example, see Patent Document 1) that allows for finer wiring as an internal electrode.

Methods for manufacturing these inductor parts include forming internal electrodes with a photosensitive conductive paste on an insulating sheet containing ceramic and resin and forming a coil by stacking a plurality of the obtained sheets, or forming a coil using a photosensitive conductive paste on an insulating sheet containing ceramic and resin. There is a method of forming a coil by alternately laminating internal electrodes made of photosensitive conductive paste and insulating layers containing ceramic and resin on an insulating sheet.

Japanese Patent Publication No. 2019-215446

When applying and drying a photosensitive conductive paste on an insulating sheet to form the above-mentioned internal electrode, if it is dried at a high temperature to dry all the solvent, there is a problem that the substrate is bent. In order to prevent this problem, it is necessary to dry the solvent at low temperature. For example, as described in Patent Document 1, when drying at low temperature using a conventional photosensitive conductive paste containing only a solvent with a relatively low boiling point, drying The solvent remains in the film. Therefore, there was a problem in which the amount of remaining solvent changed with the elapsed time after drying, resulting in a change in processability, and in an application process such as screen printing, the viscosity of the paste increased and the coating film thickness changed. Additionally, when a solvent with only a high boiling point was used, there was a problem in that the amount of solvent remaining in the dried film became too large, resulting in tackiness.

In view of the above problems, the present invention suppresses the increase in viscosity during the application process, suppresses the tackiness of the dried film even when the photosensitive conductive paste is dried at low temperature, and prevents changes over time in the amount of residual solvent contained in the dried film. The purpose is to suppress.

In order to solve the above problems, the present invention mainly has the following structures. That is, it contains conductive particles (A), a photosensitive organic component (B), and two or more types of solvents (C), and among the solvents (C), a solvent (C-1) with the lowest boiling point and a solvent with the highest boiling point The difference in boiling points of (C-2) is 35 to 120°C, the boiling point of the solvent (C-2) is 251 to 300°C, and the content of the solvent (C-2) is 25 to 25% with respect to 100% by mass of the total solvent. Photosensitive conductive paste of 80% by mass.

According to the photosensitive conductive paste of the present invention, an increase in viscosity during the application process can be suppressed, the tackiness of the dried film can be suppressed even when dried at low temperature, and the change over time in the amount of residual solvent contained in the dried film can be suppressed.

1 is a schematic diagram showing a mask pattern used in an example.

The photosensitive electrically conductive paste of the present invention contains conductive particles (A), a photosensitive organic component (B), and two or more types of solvents (C), and among the solvents (C), the solvent with the lowest boiling point (C-1) The difference between the boiling points of the solvent (C-2) with the highest boiling point is 35 to 120°C, and the boiling point of the solvent (C-2) is 251 to 300°C, with respect to 100% by mass of all solvents. ) content is 25 to 80 mass%.

The conductive particles (A) are melted and fused by heating and sintering to form an inorganic sintered body having conductivity. By including the photosensitive organic component (B), photosensitivity is imparted to the dried film of the photosensitive conductive paste, and fine wiring can be formed by the photolithography method. In addition, in the present invention, the photosensitive conductive paste contains two or more types of solvents (C), and among the solvents (C), a solvent (C-1) with the lowest boiling point and a solvent (C-2) with the highest boiling point. The difference in boiling points is 35 to 120°C, the boiling point of the solvent (C-2) is 251 to 300°C, and the content of the solvent (C-2) is 25 to 80% by mass based on 100% by mass of the total solvent. It is important. As described above, when the photosensitive conductive paste was dried at low temperature, there was a problem in that processability changed due to a change in the amount of residual solvent. Therefore, the present inventors used together two or more types of solvents (C) with a boiling point difference of 35 to 120°C between the solvent with the lowest boiling point (C-1) and the solvent with the highest boiling point (C-2), thereby making it possible to use only low boiling point solvents. It was discovered that while drying, the high boiling point solvent remained so that the amount of residual solvent could be kept constant.

(Conductive particles (A))

Conductive particles (A) are those that are melted or fused by heating and baking to develop conductivity. The conductive particles (A) include, for example, metals such as silver, gold, copper, platinum, palladium, tin, nickel, aluminum, tungsten, molybdenum, ruthenium, chromium, titanium, and indium, or any one of these metals. Examples include powders of materials selected from alloys and oxides of any of these metals. You may use two or more of these. As a material for the conductive particles, among these, silver, copper, or gold are preferable from the viewpoint of conductivity, silver, copper, or an alloy containing any of these metals is more preferable from the viewpoint of cost, and silver is preferable from the viewpoint of stability. It is more desirable.

The average secondary particle diameter (median diameter (D50)) of the conductive particles (A) is preferably 0.3 to 6.0 μm. By setting the average secondary particle diameter D50 of the conductive particles (A) to 0.3 ㎛ or more, the exposed light can be efficiently transmitted in the exposure and development process described later, curing can sufficiently proceed to the bottom, and pattern peeling can be suppressed. Thus, a thick film pattern can be formed. As for the average secondary particle diameter D50 of electroconductive particle (A), 0.8 micrometer or more is more preferable, and 1.3 micrometer or more is still more preferable. On the other hand, by setting the average secondary particle diameter D50 of the conductive particles (A) to 6.0 μm or less, shaking of the pattern after formation can be suppressed and a finer pattern can be formed. The average secondary particle diameter D50 of the conductive particles (A) is more preferably 5.5 μm or less, and further preferably 5.0 μm or less. In addition, the average secondary particle diameter D50 of the conductive particles (A) can be measured by a laser light scattering method using Microtrac HRA (Model No. 9320-X100; manufactured by Nikkiso Co., Ltd.).

The content of the conductive particles (A) in the photosensitive electrically conductive paste is preferably 35 to 60% by volume based on the total solid content. By setting the content of the conductive particles (A) to 35% by volume or more, in the firing process described later, the probability of contact between the conductive particles (A) can be improved and disconnection of the pattern can be suppressed. As for content of electroconductive particle (A), 40 volume% or more is more preferable. On the other hand, by setting the content of the conductive particles (A) to 60% by volume or less, pattern peeling during the exposure and development process can be suppressed, and a thicker film pattern can be formed. As for content of electroconductive particle (A), 55 volume% or less is more preferable. Here, the total solid content of the photosensitive electrically conductive paste refers to all components of the photosensitive electrically conductive paste excluding the solvent.

The content of conductive particles (A) in the photosensitive conductive paste was determined by applying and drying the photosensitive paste and measuring a vertical cross section of the paste-dried film from which the organic solvent was sufficiently removed using a transmission electron microscope (e.g., “JEM-4000EX” manufactured by JEOL Ltd.). ), the volume fraction of the conductive particles (A) can be calculated and obtained by analyzing the image by distinguishing the conductive particles (A) from the other components based on the light and shade of the image. At this time, the observation area using a transmission electron microscope is about 20㎛×100㎛, and the magnification is about 1,000 to 3,000 times. In addition, when the compounding quantity of each component of the photosensitive paste is known, the content of the conductive particles (A) can also be calculated from the compounding quantity.

(Photosensitive organic component (B))

The photosensitive organic component (B) refers to an organic component containing an alkali-soluble resin and a photosensitizer. Alkali-soluble resin refers to resin having an alkali-soluble group. Examples of alkali-soluble groups include carboxyl groups, phenolic hydroxyl groups, sulfonic acid groups, and thiol groups. Since it has high solubility in an alkaline developer, a carboxyl group is preferable as the alkali-soluble group.

As the alkali-soluble resin, an acrylic resin is preferable, and a copolymer of an acrylic monomer having a carbon-carbon double bond and other monomers is preferable. Examples of acrylic monomers having a carbon-carbon double bond include methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, tert-butyl acrylate, Acrylates having a chain aliphatic hydrocarbon group of 1 to 18 carbon atoms, such as n-pentyl acrylate, isodecyl acrylate, isooctyl acrylate, 2-ethylhexyl acrylate, allyl acrylate, lauryl acrylate, and stearyl acrylate. ; Acrylates having a cyclic aromatic hydrocarbon group having 6 to 10 carbon atoms, such as benzyl acrylate, phenyl acrylate, 1-naphthylacrylate, and 2-naphthylacrylate; Cyclohexyl acrylate, dicyclopentanyl acrylate, 4-tert-butylcyclohexyl acrylate, dicyclopentenyl acrylate, dicyclopentadienyl acrylate, isobornyl acrylate, 3,3,5-trimethylcyclo Acrylates having a cyclic aliphatic hydrocarbon group having 6 to 15 carbon atoms, such as hexyl acrylate, and those obtained by replacing these acrylates with methacrylates can be mentioned. You may use two or more of these. Examples of copolymerization components other than acrylic monomers include styrenes such as styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, chloromethylstyrene, and hydroxymethylstyrene; Examples include 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 two or more of these.

The acrylic resin preferably has a carbon-carbon double bond at the side chain or molecule end, and can improve the curing reaction rate during exposure. Examples of structures having a carbon-carbon double bond include vinyl group, allyl group, acrylic group, and methacryl group. You may have two or more of these. Methods for introducing a carbon-carbon double bond into an acrylic resin include, for example, a compound having a glycidyl group or an isocyanate group and a carbon-carbon double bond with respect to the mercapto group, amino group, hydroxyl group, or carboxyl group in the acrylic resin, acrylic acid. A method of reacting chloride, methacrylic acid chloride, allyl chloride, etc. can be mentioned.

Examples of compounds having a glycidyl group and a carbon-carbon double bond include glycidyl methacrylate, glycidyl acrylate, allyl glycidyl ether, glycidyl ethyl acrylate, crotonyl glycidyl ether, Glycidyl crotonate, glycidyl isocrotonate, "Cychroma" (registered trademark) M100, A200 (above, manufactured by Daicel Corporation), etc. Examples of compounds 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 two or more of these.

Examples of photosensitizers include photopolymerization initiators and dissolution inhibitors. A photopolymerization initiator is preferable from the viewpoint of forming a thicker conductive pattern.

The photopolymerization initiator absorbs and decomposes short-wavelength light such as ultraviolet rays, or generates radicals through a hydrogen abstraction reaction, thereby imparting photocurability to the photosensitive conductive paste and enabling pattern formation by negative photolithography. Photopolymerization initiators that absorb and decompose light such as ultraviolet rays include, for example, 1,2-octanedione, benzophenone, methyl ortho-benzoylbenzoate, 4,4'-bis(dimethylamino)benzophenone, and 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-azidbenzalacetophenone, 2,6 -Alkylphenone-based photopolymerization initiators such as 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 Oxime ester type photopolymerization initiator of trion-2-(O-benzoyl)oxime, etc. are mentioned.

The dissolution inhibitor increases the solubility of the exposed portion of the photosensitive conductive paste dry film in the developing solution, enabling pattern formation by a positive photolithography method. As a dissolution inhibitor, it is preferable that acid is generated by exposure energy. Examples include diazide sulfone compounds, triphenylsulfonium compounds, and quinonediazide compounds. Examples of diazide sulfone compounds include bis(cyclohexylsulfonyl)diazomethane, bis(tertiary butylsulfonyl)diazomethane, and bis(4-methylphenylsulfonyl)diazomethane. Examples of triphenylsulfonium compounds include diphenyl-4-methylphenylsulfonium trifluoromethanesulfonate, diphenyl-2,4,6-trimethylphenylsulfonium p-toluenesulfonate, and diphenyl (4-methyl Toxyphenyl) sulfonium trifluoromethane sulfonate, etc. can be mentioned. Quinone diazide compounds include, for example, a polyhydroxy compound in which the sulfonic acid of quinone diazide is bonded to an ester, a polyamino compound in which the sulfonic acid of quinone diazide is bonded to a sulfonamide compound, and a polyhydroxypolyamine compound in which quinone diazide is bonded. Examples include those in which sulfonic acid is linked to an ester linkage and/or a sulfonamide linkage. You may contain two or more of these.

The photosensitive organic component (B) may further contain a photosensitive monomer, an ultraviolet absorber, a sensitizer, etc.

Photosensitive monomer refers to a monomer or oligomer having a carbon-carbon double bond. Examples of structures having a carbon-carbon double bond include acrylic groups, methacryl groups, vinyl groups, and maleimide rings. Examples of photosensitive monomers having an acrylic group include 1,4-butanediol diacrylate, 1,3-butylene glycol diacrylate, ethylene glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, Dipentaerythritol hexaacrylate, dipentaerythritol monohydroxy pentaacrylate, ditrimethylolpropane tetraacrylate, glycerol diacrylate, neopentyl glycol diacrylate, propylene glycol diacrylate, triglycerol diacrylate, trimethyl All-propane triacrylate, bisphenol A diacrylate, isocyanuric acid EO-modified triacrylate, etc. are mentioned. Examples of photosensitive monomers having a methacryl group include those in which acrylates are replaced with methacrylates. Examples of photosensitive monomers having a vinyl group include methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, cyclohexyl vinyl ether, phenyl vinyl ether, ethylene glycol monovinyl ether, triallyl isocyanurate, etc. You can.

(Solvent (C))

The solvent (C) is a liquid at room temperature and has the function of moistening or dissolving the components constituting the photosensitive conductive paste to form a liquid with excellent applicability. As described above, the photosensitive conductive paste of the present invention contains two or more types of solvents (C), and among the solvents (C), a solvent (C-1) with the lowest boiling point and a solvent (C-2) with the highest boiling point. The difference in boiling points is 35 to 120°C, and it is important that the boiling point of the solvent (C-2) is 251 to 300°C.

If the boiling point of the solvent (C-2) is lower than 251°C, the solvent (C-2) volatilizes in the drying process described later, and the change in the amount of remaining solvent over time increases. On the other hand, if the boiling point of the solvent (C-2) is higher than 300°C, the binder removal property during baking decreases. The boiling point of the solvent (C-2) is preferably 257°C or higher from the viewpoint of further suppressing the increase in changes in the amount of residual solvent over time. Additionally, from the viewpoint of further suppressing a decrease in binder removal properties during firing, 290°C or lower is preferable. Here, the boiling point of the organic solvent (C) is disclosed in various literature, and is rounded to one decimal place. If there is no disclosure in the literature, it can be measured by the method of JIS standard K0066-1992.

Additionally, if the boiling point difference between solvent (C-1) and solvent (C-2) is less than 35°C, it becomes difficult to suppress the tackiness of the dried film by selectively drying only solvent (C-1). On the other hand, if the boiling point difference is greater than 120°C, the boiling point of the solvent (C-1) becomes too low, and an increase in the viscosity of the photosensitive conductive paste due to volatilization of the solvent easily occurs in the application process described later. The boiling point difference between solvent (C-1) and solvent (C-2) is preferably 40°C or higher, and more preferably 50°C or higher, from the viewpoint of further suppressing tackiness. Additionally, from the viewpoint of further suppressing the boiling point of the solvent (C-1) from becoming too low, the boiling point is preferably 110°C or lower, and more preferably 100°C or lower.

The solvent (C-1) preferably has a boiling point of 180 to 230°C. By setting the boiling point of the solvent (C-1) to 180°C or higher, an increase in the viscosity of the photosensitive conductive paste during the application process can be further suppressed. On the other hand, by setting the boiling point of the solvent (C-1) to 230°C or lower, the photosensitive conductive paste can be easily dried in the drying process described later. From the above viewpoint, the boiling point of solvent (C-1) is more preferably 185°C or higher, and more preferably 220°C or lower. In addition, the boiling point of the solvent refers to the boiling point at 1013.25 hPa.

Examples of the solvent (C-1) include ethylene glycol hexyl ether, ethylene glycol monobutyl ether acetate, diethylene glycol n-butyl ether, diethylene glycol ethyl ether, diethylene glycol diethyl ether, and diethylene glycol butyl methyl ether. , Diethylene glycol methyl ether, Diethylene glycol monoethyl ether, Diethylene glycol monoethyl ether acetate, Diethylene glycol monobutyl ether, Diethylene glycol monomethyl ether, dipropylene glycol n-butyl ether, dipropylene glycol propyl ether, Dipropylene glycol methyl-n-propyl ether, dipropylene glycol methyl ether, dipropylene glycol methyl ether acetate, dipropylene glycol monomethyl ether acetate, dimethyl imidazolidinone, dimethyl sulfoxide, triethylene glycol dimethyl ether, propylene glycol diacetate can be mentioned.

As a solvent (C-2), for example, 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate, 2,2,4-trimethyl-1,3-pentanediol diisobutyrate, Ethylene glycol hexyl ether, diethylene glycol mono-2-ethylhexyl ether, diethylene glycol monohexyl ether, dipropylene glycol phenyl ether, tetraethylene glycol dimethyl ether, triethylene glycol butyl methyl ether, triethylene glycol monobutyl ether, triethylene glycol Examples include propylene glycol butyl ether, tripropylene glycol monobutyl ether, and diethylene glycol dibutyl ether. Among them, a SP value of 14.6 to 21.5 (J/cm3) ^1/2 is preferable. Those with SP values of 14.6 to 21.5 (J/cm3) ^1/2 include 2,2,4-trimethyl-1,3-pentanediol monoisobutylate, tetraethylene glycol dimethyl ether, triethylene glycol butylmethyl ether, Diethylene glycol dibutyl ether can be mentioned. By setting the SP value to 14.6 or more, the photosensitive organic component (B) can be wetted or dissolved. By setting the SP value to 21.5 or less, when processing on an insulating resin layer containing ceramic, which will be described later, penetration into the insulating layer can be prevented and residues on the insulating layer can be suppressed. It is more preferable that the SP value is 20.5 or less because the above effect can be achieved more. Additionally, the SP value can be calculated from the molecular structure using Fedors' calculation method.

The solvent (C-2) is preferably a glycol alkyl ether represented by R ¹ (OC ₂ H ₄ ) _n OR ² or R ¹ (OC ₃ H ₆ ) _n OR ² . However, n is an integer of 2 to 5, R ¹ represents H or an alkyl group with 1 to 6 carbon atoms, and R ² represents an alkyl group with 1 to 6 carbon atoms. Examples of the alkyl group having 1 to 6 carbon atoms include methyl group, ethyl group, and n-butyl group. When the solvent (C-2) is the glycol alkyl ether, penetration into the insulating layer can be further prevented and residues can be suppressed.

In addition, it is important that the photosensitive conductive paste of the present invention has a solvent (C-2) content of 25 to 80 mass% based on 100 mass% of all solvents. If the content of the solvent (C-2) is less than 25% by mass, an increase in the viscosity of the photosensitive conductive paste due to volatilization of the solvent is likely to occur in the application process described later. The content of solvent (C-2) is preferably 35% by mass or more. On the other hand, when the content of solvent (C-2) is greater than 80% by mass, tackiness of the dried film is likely to occur. The content of solvent (C-2) is preferably 70% by mass or less, and more preferably 60% by mass or less. The content of the solvent (C-2) is calculated by identifying the types of all solvents contained in the photosensitive conductive paste by chemical analysis such as ¹ H-NMR and then calculating the ratio based on the peak area in the gas chromatogram. can do.

(contraction inhibitor)

(Non-conductive inorganic particles)

The photosensitive conductive paste of the present invention preferably further contains non-conductive inorganic powder, and pattern shrinkage during baking can be suppressed. The particle size of the non-conductive inorganic powder is preferably 1 to 100 nm. Non-conductive inorganic powders include, for example, alumina (Al ₂ O ₃ ), zirconia (ZrO ₂ ), magnesia (MgO), beryllia (BeO), mullite (3Al ₂ O ₃ ·2SiO ₂ ), and cordierite (5SiO). ₂ ·2Al ₂ O ₃ ·2MgO), spinel (MgO·Al ₂ O ₃ ), polysterite (2MgO·SiO ₂ ), anolsite (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 type, spinel type: MeFe ₂ O ₄ type), SiO ₂ , Al ₂ O ₃ , CaO, B ₂ O ₃ , MgO and/or TiO ₂ , etc.; Inorganic filler powders such as alumina, zirconia, magnesia, beryllia, mullite, cordierite, spinel, polsterite, anolcite, celsian, silica, and aluminum nitride can be mentioned. You may contain two or more of these. Among these, silica particles are preferable from the viewpoint of further suppressing firing defects. From the viewpoint of reducing the thixotropy of the photosensitive conductive paste and improving the surface flatness of the coating film, the silica particles are preferably alkylated on the particle surface, and among them, those are dialkyl silylated and/or trialkyl silylated. desirable. Methods for dialkyl silylating and/or trialkyl silylating the surface of silica particles include a method of reacting silica particles with dimethyldichlorosilane or hexamethyldisilazane.

(Other Ingredients)

The photosensitive electrically conductive paste of this invention may contain a dispersing agent, a plasticizer, a leveling agent, a surfactant, a silane coupling agent, an antifoaming agent, a stabilizer, etc., as long as the desired characteristics are not impaired.

(Dispersant)

A dispersant is a component that has the effect of dispersing and stabilizing the conductive particles (A) and/or non-conductive inorganic particles. Examples of the dispersant include amine-based dispersants, carboxylic acid or carboxylic acid ester-based dispersants. Among them, unsaturated fatty acids with 3 to 18 carbon atoms and/or saturated fatty acids with 3 to 18 carbon atoms are preferred because they suppress the generation of residues and facilitate thick film formation. Examples of unsaturated fatty acids include myristoleic acid, palmitoleic acid, sapienic acid, and oleic acid. Saturated fatty acids include capric acid, lauric acid, myristic acid, pentadecylic acid, palmitic acid, margaric acid, and stearic acid.

(Method for producing photosensitive conductive paste)

The photosensitive conductive paste of the present invention can be obtained, for example, by mixing and/or dispersing (A) to (C) and other additives as necessary, as described above. Examples of mixing and/or dispersing devices include dispersers such as hemp rollers and ball mills, and kneaders.

(cured film)

Next, the cured film of the present invention will be described. The cured film of the present invention is a film formed by curing the photosensitive electrically conductive paste of the present invention. The film thickness of the cured film is preferably 5 to 30 μm. By setting the film thickness of the cured film to 5 μm or more, breakage during firing can be suppressed. On the other hand, fine wiring can be formed by setting the film thickness of the cured film to 30 μm or less.

The cured film of the present invention may have a predetermined pattern shape. Examples of the pattern shape include straight lines and swirl shapes. Regarding the pattern shape, the minimum width is preferably 10 to 50 μm. By setting the pattern width to 10 μm or more, disconnection during firing can be suppressed. On the other hand, by setting the pattern width to 50 μm or less, the aspect ratio of the pattern increases and the sheet resistance of the internal wiring can be reduced.

The cured film of the present invention can be obtained, for example, by applying the photosensitive conductive paste of the present invention onto a substrate, drying it, and photocuring it through exposure. A cured film having a pattern shape can be manufactured by subjecting the cured film to pattern exposure in an exposure process and then developing it.

(Method for manufacturing a substrate with a conductive pattern)

The method for manufacturing a substrate with a conductive pattern of the present invention includes the steps of applying the photosensitive conductive paste of the present invention on a substrate to form a coating film, drying the coating film to form a dry film, exposing and developing the dried film to form a pattern. and a step of forming, wherein the amount of solvent remaining in the dried film in the step of forming the pattern is 25 to 80% by mass of the total amount of solvent contained in the photosensitive conductive paste. Hereinafter, each process will be described in detail.

First, the photosensitive conductive paste of the present invention is applied on a substrate to form a coating film.

Examples of the coating method in the coating process include spray coating, roll coating, screen printing, a coating method using a blade coater, die coater, calendar coater, meniscus coater, and bar coater. The film thickness of the coating film can be appropriately selected depending on the application method, solid content concentration or viscosity of the photosensitive paste, etc.

The coating film using the photosensitive electrically conductive paste of the present invention described above may be formed on the film after forming the film containing the inorganic particles (D) and the organic component (E) on the substrate.

A slurry in which inorganic particles are dispersed in a solution containing an organic component (E) and a solvent is applied onto a substrate and dried to form a film. The organic component (E) refers to all of the organic components remaining when a film is formed. Examples of the slurry in which the inorganic component is dispersed include a non-photosensitive slurry or a photosensitive slurry. Non-photosensitive slurry contains inorganic particles, resin, solvent, etc. The photosensitive slurry contains inorganic particles, a photosensitive organic component, a solvent, etc. The photosensitive organic component refers to a mixture of alkali-soluble resin, photosensitive agent, photosensitive monomer, etc. When forming a film containing the inorganic particles (D) and the organic component (E), a photosensitive slurry is preferable from the viewpoint of good positioning accuracy and the ability to form fine vias. That is, the organic component (E) preferably contains a photosensitive organic component. The organic component (E) may further contain a dispersant, plasticizer, leveling agent, etc., as appropriate.

Examples of the inorganic particles (D) include glass particles that soften in the firing temperature range and inorganic particles that exist as particles without softening in the firing temperature range. These can also be used in combination.

Glass particles that soften in the firing temperature range include particles of glass containing SiO ₂ , B ₂ O ₃ , K ₂ O, Li ₂ O, CaO, ZnO, Bi ₂ O ₃ and Al ₂ O ₃ .

Inorganic particles that exist as particles without softening in the firing temperature range include, for example, SiO ₂ -B ₂ O ₃ glass, quartz, alumina, magnesia, spinel, silica, polsterite, steatite, and zirconia. there is. You may use a combination of two or more of these.

Next, the coating film is dried to form a dry film.

In the method for producing a substrate with a conductive pattern of the present invention, the solvent remaining in the dried film is 25 to 80% by mass of the total amount of solvent contained in the photosensitive conductive paste. By setting the remaining solvent amount to 25% by mass, the light transmittance of the dried film is improved and a pattern with a high aspect ratio can be formed. On the other hand, by setting the amount of residual solvent to 80% by mass or less, the tackiness of the dried film can be suppressed.

Examples of drying methods include heat drying using a heating device such as an oven, hot plate, or infrared ray, or vacuum drying. The drying temperature is preferably 45 to 80°C. By setting the drying temperature to 45°C or higher, the low boiling point solvent (C-1) can be volatilized and removed efficiently and the tackiness of the dried film can be suppressed. On the other hand, by setting the drying temperature to 80°C or lower, evaporation of the high boiling point solvent (C-2) can be suppressed and warping of the substrate can be suppressed. The heating time is preferably 2 to 60 minutes.

Next, the dried film is exposed and developed to form a pattern.

Exposure methods include a method of exposure through a photomask and a method of exposure without using a photomask. Examples of exposure methods without a photomask include a method of direct painting using a laser beam or the like. Examples of the exposure device include a stepper exposure machine and a proximity exposure machine. Examples of actinic light to be exposed include near-ultraviolet rays, ultraviolet rays, electron beams, X-rays, and laser light, with ultraviolet rays being preferred. Examples of ultraviolet light sources include low-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, halogen lamps, germicidal lamps, etc., with ultra-high pressure mercury lamps being preferred.

Examples of developing solutions when performing alkaline development include tetramethylammonium hydroxide, diethanolamine, diethylaminoethanol, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, triethylamine, diethylamine, methylamine, and dimethylamine. , dimethylaminoethyl acetate, dimethylaminoethanol, dimethylaminoethyl methacrylate, cyclohexyl amine, ethylenediamine, and hexamethylenediamine. To these aqueous solutions, polar solvents such as N-methyl-2-pyrrolidone, N,N-dimethylformamide, N,N-dimethyl acetamide, dimethyl sulfoxide, and γ-butyrolactone; Alcohols such as methanol, ethanol, and isopropanol; esters such as ethyl lactate and propylene glycol monomethyl ether acetate; cyclopentanone, cyclohexanone, and isobutyl ketone; Ketones such as methyl isobutyl ketone; Surfactants, etc. may be added.

As a developing method, for example, a method of spraying a developing solution while standing, transporting, or rotating a substrate on which a cured film after exposure has been formed, a method of immersing a substrate on which a cured film after exposure has been formed in a developing solution, or a method of immersing a substrate on which a cured film has been exposed after exposure in a developing solution. A method of performing ultrasonic waves while immersed in a developing solution may be mentioned.

The pattern obtained by development may be subjected to rinsing treatment with a rinse liquid. Examples of the rinse liquid include 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. Additionally, a step of drying the remaining solvent of the pattern may be included. By drying the remaining solvent, the shrinkage rate can be reduced when baking is performed. As a drying method, a drying device similar to the above drying method can be used.

The obtained patterns can also be stacked to form a laminate. The number of layers in the laminate is preferably 2 to 30 layers. By increasing the number of layers to two or more, the thickness of a given pattern can be increased. On the other hand, by setting the number of layers to 30 or less, the influence of misalignment between layers can be reduced.

(fired body)

Next, the fired body of the present invention will be described. The fired body of the present invention is obtained by firing the cured film of the present invention, and its shape is not limited. Preferred conditions for the firing process are described later.

The thickness of the fired body is preferably 2 to 20 μm. By setting the thickness of the fired body to 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, the parts during firing can be suppressed.

The line width of the fired body of the present invention is preferably 5 to 40 μm. By setting the line width of the fired body to 5 μm or more, breakage during firing can be suppressed. On the other hand, by setting the line width of the fired body to 40 μm or less, a conductive pattern with a high aspect ratio can be formed.

(Electronic parts)

The electronic component of the present invention includes the fired body of the present invention. Electronic components include chip inductors and LC filters.

(Manufacturing method of electronic components)

The method for manufacturing an electronic component of the present invention includes a firing step of baking the base material with a conductive pattern obtained by the method for manufacturing a base material with a conductive pattern of the present invention. Furthermore, it is preferable to include a process of applying the photosensitive conductive paste, a process of drying, and a process of exposure and development. As an example of the manufacturing method of the electronic component of the present invention, the manufacturing method of the multilayer chip inductor is described below.

First, via holes are formed in the ceramic green sheet, and interlayer connection wiring is formed by filling the via holes with conductors. Examples of via hole formation methods include laser irradiation. Methods for filling a via hole with a conductor include, for example, filling a conductor paste using a screen printing method and drying it. Examples of the conductor paste include pastes containing copper, silver, and silver-palladium alloy. Since the process can be simplified by forming the interlayer connection wiring and the internal wiring at once, the photosensitive conductive paste of the present invention is preferable as the conductor paste as described above.

Internal wiring is formed on the ceramic green sheet on which the interlayer connection wiring is formed. Examples of methods for forming internal wiring include photolithography using a photosensitive conductive paste. As a photosensitive conductive paste, the photosensitive paste of the present invention can be preferably used as described above from the viewpoint of providing characteristics with a high aspect ratio and excellent conductivity. If necessary, a dielectric pattern or insulator pattern is additionally formed on the ceramic green sheet. Examples of methods for forming dielectric patterns and insulator patterns include screen printing.

Next, a plurality of ceramic green sheets forming interlayer connection wiring and internal wiring are stacked and heat-compressed to obtain a laminate. Examples of the stacking method include a method of stacking ceramic green sheets using guide holes. Examples of the thermocompression bonding device include a hydraulic press machine. The thermocompression 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 dicing the obtained multilayer body into a desired chip size using a cutting device, firing it, applying terminal electrodes, and performing a plating treatment. Examples of cutting devices include die cutting machines and laser cutting machines. Examples of the firing method include heat treatment at 300 to 600°C for 5 minutes to several hours, followed by further heat treatment at 850 to 900°C for 5 minutes to several hours. Examples of methods for applying terminal electrodes include sputtering and the like. Examples of metals used in plating treatment include nickel and tin.

Example

Hereinafter, the present invention will be described in more detail through examples and comparative examples, but the present invention is not limited to these.

(Photosensitive conductive paste)

The raw materials used for the photosensitive conductive paste are as follows.

Conductive particles (A)

Conductive particles (A-1): Ag particles with D50 of 3.2㎛

Conductive particles (A-2): Ag particles with D50 of 0.5㎛

Conductive particles (A-3): Ag particles with D50 of 1.1㎛

Conductive particles (A-4): Ag particles with D50 of 2.0㎛

Conductive particles (A-5): Ag particles with D50 of 4.0㎛

Conductive particles (A-6): Ag particles with D50 of 5.3㎛

In addition, D50 of the conductive particles was measured by a laser light scattering method using a particle size distribution measuring device (Microtrac HRA Model No. 9320-X100; manufactured by Nikkiso Co., Ltd.).

Photosensitive organic component (B)

Alkali-soluble resin: Acrylic resin obtained by addition reaction of 40 mol parts of glycidyl methacrylate with respect to 100 mol parts of carboxyl groups of a copolymer of methacrylic acid/methyl methacrylate/styrene = 54/23/23 (molar ratio) Average molecular weight 30,000, glass transition point 110°C, acid value 100 mgKOH/g).

Photosensitive monomer: NK oligo UA-122P (urethane acrylate containing ester structure, viscosity 7.0 Pa·s, weight average molecular weight 1,100, manufactured by Shin-Nakamura Chemical Co., Ltd.).

Photosensitive agent (photopolymerization initiator 1): ADEKAOPTOMER N-1919 (made by ADEKA).

(Other Ingredients)

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

Dispersant 1: Stearic acid

Dispersant 2: Oleic acid

Dispersant 3: FULLERENE G-700 (manufactured by Kyoeisha Chemical Co., Ltd.).

(Solvent (C))

Solvent 1: Ethylene glycol butyl ether (boiling point: 168°C, SP value: 22.1 (J/cm3) ^1/2 )

Solvent 2: Ethylene glycol monobutyl ether acetate (boiling point: 188°C, SP value: 18.9 (J/cm3) ^1/2 )

Solvent 3: Dipropylene glycol monobutyl ether (boiling point: 230°C, SP value: 20.9 (J/cm3) ^1/2 )

Solvent 4: Diethylene glycol dibutyl ether (boiling point: 256°C, SP value: 17.0 (J/cm3) ^1/2 )

Solvent 5: Tetraethylene glycol dimethyl ether (boiling point: 275°C, SP value: 17.5 (J/cm3) ^1/2 )

Solvent 6: Triethylene glycol butyl methyl ether (boiling point: 261°C, SP value: 17.2 (J/cm3) ^1/2 )

Solvent 7: 2,2,4-trimethyl-1,3-pentanediol diisobutyrate (boiling point: 280°C, SP value: 18.5 (J/cm3) ^1/2 )

Solvent 8: Triethylene glycol monobutyl ether (boiling point: 271°C, SP value: 21.1 (J/cm3) ^1/2 )

Solvent 9: Dipropylene glycol phenyl ether (boiling point: 280°C, SP value: 23.0 (J/cm3) ^1/2 )

Solvent 10: Diethylene glycol butyl ether (boiling point: 150°C, SP value: 21.5 (J/cm3) ^1/2 )

Additionally, the SP value of the solvent (C) was calculated from the molecular structure using Fedors' calculation method.

non-conductive inorganic particles

D-1: "AEROSIL" (registered trademark) 300 (manufactured by NIPPON AEROSIL CO., LTD.): Silica particles

D-2: "AEROSIL" (registered trademark) R976 (manufactured by NIPPON AEROSIL CO., LTD.): Silica particles whose particle surface is dialkyl silylated.

(Example 1)

5.0 g of alkali-soluble resin, 2.4 g of NK oligo UA-122P (photosensitive monomer), 0.5 g of ADEKAOPTOMER N-1919 (photopolymerization initiator 1), 0.1 g of “DISPARLON” (registered trademark) L-1980N (leveling agent) , 0.1 g of dispersant 1, 5.9 g of ethylene glycol monobutyl ether acetate (solvent 2), and 5.9 g of diethylene glycol dibutyl ether (solvent 4) were mixed to obtain 19.9 g of photosensitive resin solution.

The obtained 19.9 g photosensitive resin solution and 61.6 g Ag particles (A-1) were mixed and kneaded using three rollers to obtain photosensitive conductive paste P-1 shown in Tables 1 and 2. In addition, the content (volume %) of the above-mentioned conductive particles (A) in the total solid content was calculated from the weight and density of each component. However, the density of all organic components was calculated as 1.0 g/cm3.

<Evaluation of viscosity change rate>

The viscosity change rate of the photosensitive electrically conductive paste was measured as follows. 300 g of photosensitive conductive paste was placed on a screen plate and applied on an alumina substrate in a square pattern of 100 mm x 100 mm so that the paste weight was 0.6 g. This printing process was repeated 300 times, and the change in viscosity of the paste on the screen plate before printing and after printing 300 times was evaluated. If the viscosity change rate before printing was 0% or more and less than 5%, it was rated as “good,” if it was 5% or more and less than 10%, it was rated as “positive,” if it was 10% or more and less than 20%, it was rated as “a,” and if it was 20% or more, it was rated as “impossible.” In addition, the viscosity is a value measured at 10 rpm using a Brookfield type viscometer, and the viscosity change rate is calculated from the following equation.

Viscosity change rate (%) = (Viscosity after printing/Viscosity before printing-1)×100.

<Evaluation of paste solvent ratio and rate of change over time>

1.00 g of photosensitive electrically conductive paste was put into an aluminum cup and dried at 150°C for 2 hours, and then the weight of the photosensitive electrically conductive paste was measured. From the change in mass of the paste before and after heating, the ratio (mass %) of the solvent contained in the photosensitive conductive paste (hereinafter referred to as paste solvent ratio) was calculated from the following equation.

Paste solvent ratio (mass%) = (1.00g - paste weight after drying)/1.00g×100.

Subsequently, the photosensitive conductive paste was applied on the alumina substrate in a square pattern of 100 mm x 100 mm by screen printing so that the film thickness was 15 μm after drying, and the weight (b) of the applied paste was measured. Next, the substrate to which the paste was applied was dried at 60°C for 10 minutes, and the weight (c) of the dried film was measured within 10 minutes after drying. The residual solvent ratio/initial time was calculated using the following equation.

Residual solvent amount/initial (mass %) = (paste solvent ratio-(1-(weight of dried film (c)/applied paste weight (b))) x 100)/paste solvent ratio x 100.

In addition, after drying, the weight of the dried film after 10 hours at room temperature was measured in the same manner as above, the amount of residual solvent was calculated after 10 hours, and the rate of change over time (hereinafter, rate of change over time) of the amount of solvent remaining in the dried film was calculated. It was obtained by the following equation.

Rate of change over time (%) = (1-(remaining solvent amount·after 10 hours)/(remaining solvent amount·initial))×100.

If the rate of change over time was 0% or more but less than 5%, it was rated as “good,” if it was 5% or more and less than 10%, it was rated as “positive,” if it was 10% or more and less than 20%, it was rated as “a,” and if it was 20% or more, it was rated as “impossible.”

<Text evaluation>

On an alumina substrate, a photosensitive conductive paste was applied by screen printing in a square pattern of 100 mm x 100 mm to a film thickness of 15 μm after drying, and dried at 60° C. for 10 minutes to produce a dried film. A PET film and a weight of 50 g with an area of 50 mm x 50 mm were placed on the dried film for 1 minute, and the tackiness of the dried film was evaluated from the area of the dried film transferred to the PET film. If the transfer area is 0% or more and less than 1% of 50mm did.

<Flatness evaluation>

A dried membrane was produced in the same manner as in <Tackiness evaluation>. Using a laser microscope VK-X200 (manufactured by KEYENCE CORPORATION), the surface roughness Sa of the dried film was measured with a 20x objective lens. When the surface roughness Sa (arithmetic mean height) was less than 0.3㎛, it was rated as “Right”; if it was between 0.3㎛ and less than 0.5㎛, it was rated as “Positive”; if it was between 0.5㎛ and less than 0.7㎛, it was rated as “A”; and if it was over 0.7㎛, it was rated as “No.”

<Processability evaluation (maximum film thickness)>

After drying the photosensitive conductive paste on an alumina substrate, a dried film was produced by changing the film thickness at 1㎛ intervals so that the film thickness was 10 to 20㎛, and L (line opening width) / S (space width) = 25/35. Full line exposure was performed using an exposure device (PEM-6M; manufactured by Union Optical Co., Ltd.) at an exposure amount with a line width of 30 μm, through an exposure mask with a stripe pattern, and 0.2% by mass of Na ₂ CO ₃ After the substrate was immersed in the solution, it was rinsed with ultrapure water and developed to remove the unexposed portion of the dried film. After development, the maximum film thickness without breakage or peeling was determined. In addition, the line width of the conductive pattern was measured using an optical microscope and observed at a magnification of 1000 times. The film thickness of the conductive pattern was measured using a stylus-type step meter (for example, "SURFCOM" (registered trademark) 1400; manufactured by TOKYO SEIMITSU CO., LTD.).

<Sheet resistance evaluation>

On the alumina substrate, a conductive pattern was formed with the maximum film thickness using the same method as <Processability Evaluation (Maximum Film Thickness)>. However, the exposure mask was set to the mask pattern shown in FIG. 1, and the opening width was 25 μm and the length was 40 mm. The substrate with the obtained conductive pattern was fired at 880°C for 10 minutes to obtain a fired body with a conductive pattern. The resistance value R of the conductive pattern fired body was measured using a digital multimeter (CDM-16D; manufactured by CUSTOM corporation). Next, the line width after firing and the film thickness after firing of the conductive pattern fired body were measured in the same manner as above, and the aspect ratio and sheet resistance were calculated using the following equations.

Aspect ratio = film thickness after firing (㎛) / line width after firing (㎛)

Sheet resistance (mΩ/□) = conductive pattern resistance (mΩ) × line width (mm) ÷ conductive pattern length (mm).

<Residue evaluation>

A substrate with an insulating ceramic layer was produced through the following procedures.

100 parts by volume of "Palceram" (registered trademark) BT149 (manufactured by Nippon Chemical Industrial CO., LTD.) as insulating ceramic powder, 240 parts by volume of polyvinyl butyral resin as binder resin, 80 parts by volume of dibutyl phthalate as plasticizer, solvent A base material with an insulating ceramic layer was produced by mixing 160 parts by volume of ethylene glycol monobutyl ether, applying it on a PET film using a doctor blade method, and drying it at 70°C for 10 minutes.

On the substrate with the insulating ceramic layer, a dried film was produced by the same method as <Tackiness Evaluation>. Next, the substrate was immersed in a 0.2% by mass Na ₂ CO ₃ solution and then rinsed with ultrapure water to dissolve the dried film. The amount of dried film residue remaining on the substrate after rinsing treatment was evaluated. Evaluation was made by using a scanning electron microscope (S2400; manufactured by Hitachi, Ltd.), observing at a magnification of 500 times, and counting the number of conductive particles remaining in the range of 250 ㎛ x 250 ㎛. Evaluate 10 places, and if the average number is 0 to 5, it is “Number”, if it is 6 to 10, it is “U”, if it is 11 to 20, it is “Yang”, if it is 21 to 30, it is “A”, and if it is 31 or more, it is “Yang”. “Impossible.”

(Examples 2 to 22, Comparative Examples 1 to 5)

A photosensitive resin solution was produced in the same manner as in Example 1, except that the solvent was changed as shown in Tables 2 and 4. The mass ratio of the amount of each solvent to the total solvent amount is shown in Tables 2 and 4. Subsequently, the photosensitive resin solution and the conductive particles shown in Tables 1 and 3 were mixed in the same manner as in Example 1 to produce photosensitive electrically conductive pastes P-2 to 22 and R-1 to 5. However, the ratio of the photosensitive resin solution and the conductive particles was adjusted so that it became the volume ratio of the conductive particles in the total solid content shown in Tables 1 and 3. The density of the photosensitive resin solution was calculated as 1.0 g/cm3. Subsequently, the produced photosensitive electrically conductive pastes P-2 to 22 and R-1 to R-5 were evaluated in the same manner as in Example 1. The results are shown in Tables 5 and 6.

(Examples 23, 24)

A photosensitive resin solution was prepared in the same manner as Example 1. Subsequently, the photosensitive resin solution, conductive particles, and non-conductive inorganic particles were mixed to the volume ratio shown in Table 3 and kneaded using three rollers to prepare photosensitive conductive pastes P-23 and 24 shown in Tables 3 and 4. Produced. However, the density of the photosensitive resin solution was calculated as 1.0 g/cm3, and the density of the non-conductive inorganic particles was calculated as 2.2g/cm3. Subsequently, the produced photosensitive conductive pastes P-23 and 24 were evaluated in the same manner as Example 1. The results are shown in Table 6.

The photosensitive conductive paste of the present invention can be suitably used for manufacturing internal wiring patterns of electronic components and the like.

1 mask pattern L Mask opening width

Claims (14)

Contains conductive particles (A), a photosensitive organic component (B), and two or more types of solvents (C),
Among the solvents (C), the difference in boiling points between the solvent with the lowest boiling point (C-1) and the solvent with the highest boiling point (C-2) is 35 to 120°C,
The boiling point of the solvent (C-2) is 251 to 300°C,
A photosensitive electrically conductive paste containing 25 to 80% by mass of the solvent (C-2) based on 100% by mass of all solvents. According to claim 1,
A photosensitive conductive paste wherein the solvent (C-1) has a boiling point of 180 to 230°C. According to claim 1,
A photosensitive conductive paste whose SP value of the solvent (C-2) is ^1/2 of 14.6 to 21.5 (J/cm3). According to claim 1,
A photosensitive electrically conductive paste wherein the solvent (C-2) is a glycol alkyl ether represented by R ¹ (OC ₂ H ₄ ) _n OR ² or R ¹ (OC ₃ H ₆ ) _n OR ² .
However, n is an integer of 2 to 5, R ¹ represents hydrogen or an alkyl group with 1 to 6 carbon atoms, and R ² represents an alkyl group with 1 to 6 carbon atoms. According to claim 1,
A photosensitive conductive paste further comprising silica particles, wherein the surface of the silica particles is dialkyl silylated and/or trialkyl silylated. According to claim 1,
A photosensitive conductive paste wherein the conductive particles (A) are silver, copper, or an alloy containing any one of these metals, and the average secondary particle diameter (median diameter (D50)) is 0.3 to 6.0 μm. According to claim 1,
A photosensitive conductive paste further comprising an unsaturated fatty acid having 3 to 18 carbon atoms and/or a saturated fatty acid having 3 to 18 carbon atoms. A process of applying the photosensitive conductive paste according to any one of claims 1 to 7 on a substrate to form a coating film, drying the coating film to form a dry film, exposing and developing the dried film to form a pattern. A method of manufacturing a substrate having a conductive pattern, including a step, wherein the amount of solvent remaining in the dried film is 25 to 80% by mass of the total amount of solvent contained in the photosensitive conductive paste. A process of forming a film containing inorganic particles (D) and an organic component (E) on a substrate, and then applying the photosensitive conductive paste according to any one of claims 1 to 7 on the film to form a coating film. , a process of drying the coating film at 45 to 80°C to form a dry film, exposing and developing the dried film to form a pattern, and the amount of solvent remaining in the dried film is contained in the photosensitive conductive paste. A method for producing a substrate having a conductive pattern that is 25 to 80% by mass of the total solvent amount. In paragraph 9,
A method for producing a substrate having a conductive pattern wherein the organic component (E) contains a photosensitive organic component. A method of manufacturing an electronic component comprising a firing step of firing a base material having a conductive pattern obtained by the method of manufacturing a base material having a conductive pattern according to any one of claims 8 to 10. A cured film formed by curing the photosensitive conductive paste according to any one of claims 1 to 7. A fired body obtained by firing the cured film according to claim 12. An electronic component comprising the fired body according to claim 13.