JPH09304922A - Photosensitive paste - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform patterning at a high aspect ratio and with high accuracy by taking an organic compound containing a photosensitive compound, inorganic particles and a visible light-sensitive polymerization initiator as essential components. SOLUTION: A photosensitive paste comprises inorganic particles and organic components containing a photosensitive compound, and after a pattern is formed using photolithography by photosensitive organic components, burning is performed to create a pattern of an inorganic substance. Exposure by visible light, especially exposure by laser light is made possible by adding a visible light-sensitive polymerization initiator to the above photosensitive paste so as to simply enable patterning with high accuracy. The percentage content of inorganic particles in the paste is 60-95wt.% and further preferably 70-95wt.%, to reduce rate of shrinkage and decrease a change in shape due to burning. Further, a difference between the average refractive index of inorganic particles and that of organic components is 0.03 or less.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a novel photosensitive paste. The photosensitive paste of the present invention is used for pattern processing of various displays including plasma displays and plasma addressed liquid crystal displays, circuit materials, and the like.

[0002]

2. Description of the Related Art In recent years, miniaturization and miniaturization have been advanced in pattern processing of circuit materials and displays.

In particular, for forming packaging materials and partition walls of plasma display panels, materials capable of patterning inorganic materials such as glass with high precision and high aspect ratio are desired.

Conventionally, when patterning an inorganic material, screen printing using a paste composed of an inorganic powder and an organic binder is often used. However, screen printing has a drawback that a highly accurate pattern cannot be formed.

As a method for improving this problem, in the field of plasma displays, JP-A-1-296534, JP-A-2-165538, and JP-A-5-342 are used.
Japanese Patent Laid-Open No. 992 proposes a method of forming a photosensitive paste by a photolithography technique. However, since the sensitivity and resolution of the photosensitive paste are low, high aspect ratio and high definition partition walls cannot be obtained. For example, when patterning a material having a thickness exceeding 80 μm, a plurality of processing steps (screen Printing / exposure / development).

In Japanese Patent Application Laid-Open No. 2-165538, after a photosensitive paste is coated on a transfer paper,
Japanese Patent Application Laid-Open No. 3-57138 proposes a method of transferring a transfer film onto a glass substrate to form partitions, in which grooves of a photoresist layer are filled with a dielectric paste to form partitions. . In addition, JP-A-4-109
Japanese Patent No. 536 proposes a method of forming partition walls using a photosensitive organic film. However, these methods have a problem that the number of processes is increased because a transfer film, a photoresist, or an organic film is required. Further, a partition having a high definition and a high aspect ratio has not been obtained. Also, not only partition walls,
In some cases, pattern processing of an insulator layer or a dielectric layer is required, but there is a problem similar to that of a partition.

On the other hand, in the field of circuit materials, although a technique for precisely processing a ceramic substrate on which an IC is mounted is required, in the present circumstances, screen printing and pattern formation by punching are performed. There is a need for a technology to meet the demand for highly accurate patterning accompanying the miniaturization of the above.

[0008]

DISCLOSURE OF INVENTION Problems to be Solved by the Invention The present inventors diligently studied for the purpose of providing a photosensitive paste which does not have the above-mentioned drawbacks, particularly a photosensitive paste which enables pattern processing with a high aspect ratio and high accuracy. I went.

As a result, in the method of applying a paste and then using a photomask for exposure, when the size is increased, the accuracy of the photomask may be deteriorated due to deformation of the photomask, and a wide variety of patterns are formed. However, there is a problem that many kinds of photomasks are required when the above is required.

[0010]

The above problems can be solved by a photosensitive paste containing an organic component containing a photosensitive compound, inorganic fine particles and a visible light-sensitive polymerization initiator as essential components.

In particular, by controlling the refractive index of the organic component and the inorganic component in the photosensitive paste, the reflection / scattering at the interface between the organic component and the inorganic component is reduced, and the pattern processing with a high aspect ratio and high precision can be performed. The present invention relates to a photosensitive paste which is characterized by being performed.

Since the photosensitive paste of the present invention can be exposed to a wavelength of visible light laser such as an argon ion laser to form a highly precise pattern, photolithography without using a photomask, that is, drawing exposure is possible. There are advantages. In this case, it is possible to prevent a decrease in accuracy due to an increase in size and to prevent the occurrence of defects due to the photomask.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The photosensitive paste of the present invention comprises an organic component containing inorganic fine particles and a photosensitive compound, and is baked after pattern formation using photolithography with the photosensitive organic component to carry out an inorganic substance. To create a pattern. In the present invention, by adding a visible light-sensitive polymerization initiator to this photosensitive paste, it becomes possible to perform exposure with visible light, in particular, exposure with laser light, and easily perform highly precise pattern processing. Become.

The content of the inorganic fine particles in the paste is 60-
It is preferable that the content be 95% by weight, more preferably 70 to 95% by weight, since the shrinkage ratio during firing is small and the shape change due to firing is small. Furthermore, it is preferable that the content of each component be the following amount.

Organic component containing photosensitive compound: 5 to 40 parts by weight Inorganic fine particles: 60 to 95 parts by weight Visible light-sensitive polymerization initiator: 0.05 to 5 parts by weight Further, the average refractive index of the organic component and the inorganic fine particles. By setting the difference in the average refractive index of 0.1 or less, more preferably 0.07 or less, a pattern having a high aspect ratio can be easily obtained.

Furthermore, when the average refractive index N1 of the inorganic fine particles in the photosensitive paste and the refractive index N2 of the photosensitive organic component satisfy the following equation, a pattern having a high aspect ratio can be formed with high precision. -0.03 <N1-N2 <0.07 More preferably, -0.01 <N1-N2 <0.07.

The inorganic fine particles are not particularly limited as long as they are general ones, but glass, ceramics (alumina, cordierite, etc.) and the like are preferable because of their excellent transparency. In particular, glass and ceramics containing silicon oxide, boron oxide or aluminum oxide as an essential component are preferably used. These are insulators and are preferably used for forming an insulating pattern, particularly for forming partition walls of a plasma display or a plasma addressed liquid crystal display.

The particle size of the inorganic fine particles is selected in consideration of the shape of the pattern to be produced. The 50 wt% particle size is 0.1 to 10 μm, and the 10 wt% particle size is 0.4 to 2.
It is preferable in terms of pattern formation that inorganic particles having a particle size of 4 to 10 μm and a specific surface area of 0.2 to ³ m ² / g are used.

Further, by using inorganic fine particles having a spherical shape as the inorganic fine particles, patterning with a high aspect ratio is possible. Specifically, a sphericity of 80
It is preferable that the number is not less than the number%. More preferably, the average particle size is 1.5 to 4 μm, and the specific surface area is 0.5 to 1.5 m ² /
g, sphericity is 90% by number or more.

The sphericity is the proportion of particles having a spherical or ellipsoidal shape under a microscope observation, and is observed as a circle or an ellipse under an optical microscope.

When used as a partition wall of a plasma display or a plasma addressed liquid crystal display, since a pattern is formed on a glass substrate having a low thermal softening point, 60% by weight of glass fine particles having a thermal softening temperature of 350 to 600 ° C. are used as inorganic fine particles. It is preferable to use the inorganic fine particles containing the above.

Total light transmittance at a wavelength of 436 nm (3 m
By using glass fine particles obtained by pulverizing glass having a m thickness of 50% or more, a pattern with a more accurate shape can be obtained.

In order to prevent warpage of the substrate glass during firing, the coefficient of linear thermal expansion should be 50 to 90 × 10 ^-7 ,
Furthermore, it is preferable to use glass particles of 60 to 90 × 10 ⁻⁷ .

As the composition in the glass fine particles, silicon oxide is preferably added in the range of 3 to 60% by weight.
When the content is less than the weight percentage, the denseness, strength and stability of the glass layer are reduced, and the coefficient of thermal expansion deviates from desired values, so that a mismatch with the glass substrate is likely to occur. Further, when the content is set to 60% by weight or less, there is an advantage that the heat softening point is lowered and baking on a glass substrate becomes possible.

By blending boron oxide in the range of 5 to 50% by weight, electrical, mechanical and thermal properties such as electric insulation, strength, coefficient of thermal expansion and denseness of the insulating layer can be improved. If it exceeds 50% by weight, the stability of the glass will decrease.

By using glass fine particles containing at least one of bismuth oxide, lead oxide, lithium oxide, sodium oxide and potassium oxide in an amount of 5 to 50% by weight, a glass paste having a temperature characteristic capable of being patterned on a glass substrate is obtained. Obtainable. If it exceeds 50% by weight, the heat-resistant temperature of the glass becomes too low, and it is difficult to bake the glass on a glass substrate. In particular, bismuth oxide
Use of glass containing 50% by weight has advantages such as long pot life of the paste.

The glass composition containing bismuth oxide includes:
In terms of oxide, bismuth oxide 5 to 50 parts by weight, silicon oxide 3 to 60 parts by weight, and boron oxide 5 to 50 parts by weight are preferably contained in an amount of 50% by weight or more.

Incidentally, glass generally used as an insulator has a refractive index of about 1.5 to 1.9.
When the average refractive index of the organic component is significantly different from the average refractive index of the inorganic fine particles, reflection and scattering at the interface between the inorganic fine particles and the photosensitive organic component are increased, and a fine pattern cannot be obtained. Since the refractive index of a general organic component is 1.45 to 1.7, the average refractive index of the inorganic fine particles is adjusted to 1.5 to 1.7 to match the refractive indexes of the inorganic fine particles and the organic component. be able to. Preferably, the refractive index is 1.55-1.
By setting it to 65, there is an advantage that the range of selection of the organic component is expanded.

A total of 3 to 20% by weight of alkali metal oxides such as lithium oxide, sodium oxide and potassium oxide.
By using the glass fine particles contained, not only the thermal softening temperature, it is easy to control the thermal expansion coefficient, it is possible to lower the average refractive index of the glass,
It becomes easy to reduce the difference in refractive index from the organic substance. In order to improve the stability of the paste, the amount of the alkali metal oxide added is preferably 20% by weight or less, more preferably 15% by weight or less.

Particularly, among the alkali metals, the use of lithium oxide makes it possible to relatively increase the stability of the paste. In the case of using potassium oxide,
Among the alkali metal oxides, the addition of lithium oxide and potassium oxide is effective because there is an advantage that the refractive index can be controlled by adding a relatively small amount.

As a result, it has a thermal softening temperature at which it can be burned on a glass substrate, can have an average refractive index of 1.5 to 1.7, and can easily reduce the refractive index difference from the organic component. become.

Glass containing lead oxide or bismuth oxide is preferable from the viewpoint of improving the heat softening temperature and water resistance, but glass fine particles containing 10% by weight or more of lead oxide and bismuth oxide have a refractive index of 1.6 or more. There are many things. Therefore, by using an oxide of an alkali metal such as sodium oxide, lithium oxide or potassium oxide in combination with lead oxide or bismuth oxide, it becomes easy to control the thermal softening temperature, thermal expansion coefficient, water resistance and refractive index.

Further, by adding aluminum oxide, barium oxide, calcium oxide, magnesium oxide, titanium oxide, zinc oxide, zirconium oxide, etc., particularly aluminum oxide, barium oxide, zinc oxide, to the glass fine particles, the hardness and processing can be improved. Although it is possible to improve the property, from the point of control of thermal softening point, thermal expansion coefficient, refractive index,
The content thereof is preferably 40% by weight or less, more preferably 30% by weight or less, and the total of these contents is 50% by weight or less.

Further, by adding glass fine particles or ceramic fine particles having a thermal softening point of 600 ° C. or higher to the inorganic fine particles used in the present invention in the range of 40% by weight or less of the inorganic fine particles, the shrinkage rate during firing is reduced. Can be suppressed. However, the difference in the refractive index of the inorganic fine particles used in this case is 0.1 or less, and further, 0.05 or less,
This is important for forming a pattern with high accuracy.

On the other hand, as a glass material for use in a circuit material, particularly a multi-layer substrate, a ceramic other than glass can be used as the substrate, so that the thermal softening temperature is 6
There is no need to set the temperature to 00 ° C. or lower, and by setting the content of aluminum oxide to about 25 to 75% by weight as a material, a substrate having higher strength can be formed.

The refractive index of the inorganic fine particles in the present invention can be measured by the Becke method. The wavelength of the light to be measured is accurate to confirm the effect by measuring the wavelength of the light to be exposed after applying the paste. In particular, 40
It is preferable to measure with light having a wavelength in the range of 0 to 900 nm. Furthermore, the refractive index measurement at 466 nm or 488 nm is preferable.

The pattern after firing can be colored by adding various metal oxides. For example, a black pattern can be formed by including 1 to 10% by weight of a black metal oxide in the photosensitive paste.

As the black metal oxide used at this time,
By including at least one, and preferably three or more of the oxides of Cr, Fe, Co, Mn, and Cu, blackening becomes possible. In particular, a blacker pattern can be formed by containing 0.5 wt% or more of each of Fe and Mn oxides.

Further, by using a paste to which an inorganic pigment that develops colors other than black, such as red, blue and green, is added, a pattern of each color can be formed. These coloring patterns can be suitably used for a color filter of a plasma display and the like.

Further, as the inorganic fine particles used in the present invention, fine particles having different components can be used in combination. In particular, by using glass fine particles or ceramic fine particles having different thermal softening points, the shrinkage rate during firing can be suppressed. However, regarding the inorganic fine particles having different components used in this case, the difference in refractive index between the fine particles is 0.
It is important that 1 or less, and further 0.05 or less, in order to form a pattern with high accuracy.

The organic component used in the present invention is
The organic component in the paste containing a photosensitive organic substance (the portion obtained by removing the inorganic component from the paste).

Regarding the photosensitive paste used in the present invention, the content of the photosensitive component is preferably 10% by weight or more, more preferably 30% by weight or more in the organic component from the viewpoint of light sensitivity.

The organic component contains a photosensitive component selected from at least one selected from a photosensitive monomer, a photosensitive oligomer and a photosensitive polymer, and further contains a binder, a photopolymerization initiator, an ultraviolet absorber, if necessary. Additives such as sensitizers, sensitization aids, polymerization inhibitors, plasticizers, thickeners, organic solvents, antioxidants, dispersants, organic or inorganic precipitation inhibitors and leveling agents can also be added. Be seen.

In the present invention, a polymerization initiator sensitive to visible light is contained as an essential component. As the polymerization initiator which can be exposed to visible light, a general visible light polymerization initiator can be used. Complex of cationic dye having near-ultraviolet absorption with borate anion, combination of silver halide sensitized with near infrared sensitizing dye and reducing agent, titanocene, iron arene complex, organic peroxide , Hexaarylbiimidazole, N-phenylglycine, diaryliodonium salt, and at least one radical generator,
Furthermore, if necessary, 3-substituted coumarin, cyanine dye,
Sensitizing dyes such as merocyanine dyes, thiazole dyes and pyrylium dyes can be used, and functional materials of CMC Co., Ltd., October 1986 p. 56-59, the polymerization initiators disclosed in JP-A-3-111402, JP-A-3-179003, and JP-A-3-802.
51, JP-A-7-114176, JP-A-6
The polymerization initiators disclosed in JP-A-67414 and JP-A-6-67425 can be used.

The photosensitive component includes a photo-insolubilizing type and a photo-solubilizing type. The photo-insolubilizing type includes: (A) a functional monomer having at least one unsaturated group or the like in a molecule. (B) those containing photosensitive compounds such as aromatic diazo compounds, aromatic azide compounds, and organic halogen compounds. (C) So-called diazo resins such as condensates of diazo amines and formaldehyde. And others.

Examples of the photo-soluble type include (D) a complex of a diazo compound with an inorganic salt or an organic acid, and a compound containing a quinone diazo compound. (E) a quinone diazo compound combined with an appropriate polymer binder. For example, phenol, naphthoquinone-1,2-diazide-5-sulfonic acid ester of a novolak resin, and the like.

As the photosensitive component used in the present invention, all of the above can be used. The photosensitive component that can be easily used as a photosensitive paste by mixing with inorganic fine particles is preferably (A).

The photosensitive monomer is a compound having a carbon-carbon unsaturated bond, and specific examples thereof include methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, and sec-butyl. Acrylate, sec-
Butyl acrylate, iso-butyl acrylate, te
rt-butyl acrylate, n-pentyl acrylate, allyl acrylate, benzyl acrylate, butoxyethyl acrylate, butoxytriethylene glycol acrylate, cyclohexyl acrylate, dicyclopentanyl acrylate, dicyclopentenyl acrylate, 2-ethylhexyl acrylate, glycerol acrylate, glycidyl acrylate Heptadecafluorodecyl acrylate, 2-hydroxyethyl acrylate, isobonyl acrylate, 2-hydroxypropyl acrylate, isodexyl acrylate, isooctyl acrylate, lauryl acrylate, 2-
Methoxyethyl acrylate, methoxyethylene glycol acrylate, methoxydiethylene glycol acrylate, octafluoropentyl acrylate, phenoxyethyl acrylate, stearyl acrylate, trifluoroethyl acrylate, allylated cyclohexyl diacrylate, 1,4-butanediol diacrylate, 1,3-butylene Glycol diacrylate, ethylene glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, polyethylene glycol diacrylate, dipentaerythritol hexaacrylate, dipentaerythritol monohydroxypentaacrylate, ditrimethylolpropane tetraacrylate, glycerol diacrylate, methoxide Shi of cyclohexyl diacrylate, neopentyl glycol diacrylate, propylene glycol diacrylate, polypropylene glycol diacrylate, triglycerol diacrylate,
Trimethylolpropane triacrylate, acrylamide, aminoethyl acrylate, phenyl acrylate, phenoxyethyl acrylate, benzyl acrylate, 1-naphthyl acrylate, 2-naphthyl acrylate, bisphenol A diacrylate, diacrylate of bisphenol A-ethylene oxide adduct,
Bisphenol A-propylene oxide adduct diacrylate, thiophenol acrylate, benzyl mercaptan acrylate, and monomers in which 1 to 5 hydrogen atoms of these aromatic rings are substituted with chlorine or bromine atoms, or styrene, p -Methylstyrene,
o-methylstyrene, m-methylstyrene, chlorinated styrene, brominated styrene, α-methylstyrene, chlorinated α
-Methyl styrene, brominated α-methyl styrene, chloromethyl styrene, hydroxymethyl styrene, carboxymethyl styrene, vinyl naphthalene, vinyl anthracene, vinyl carbazole, and part or all of the acrylate in the molecule of the above compound to methacrylate Modified ones include γ-methacryloxypropyltrimethoxysilane, 1-vinyl-2-pyrrolidone and the like. In the present invention, these may be used alone or in combination of two or more.

In addition to these, the developability after exposure can be improved by adding an unsaturated acid such as an unsaturated carboxylic acid. Specific examples of the unsaturated carboxylic acid include acrylic acid, methacrylic acid, itaconic acid, crotonic acid, maleic acid, fumaric acid, vinyl acetic acid, and acid anhydrides thereof.

As the binder, polyvinyl alcohol, polyvinyl butyral, methacrylate polymer, acrylate polymer, acrylate ester
Examples include methacrylate copolymers, α-methylstyrene polymers, and butyl methacrylate resins.

Further, an oligomer or a polymer obtained by polymerizing at least one of the compounds having a carbon-carbon double bond can be used.

During the polymerization, the content of these monomers may be 10% by weight or more, more preferably 35% by weight or more, and the monomers may be copolymerized with other photosensitive monomers.

As a monomer to be copolymerized, an unsaturated acid such as unsaturated carboxylic acid can be copolymerized to improve the developability after exposure. Specific examples of the unsaturated carboxylic acid include acrylic acid, methacrylic acid, itaconic acid, crotonic acid, maleic acid, fumaric acid, vinyl acetic acid, and acid anhydrides thereof.

The acid value (AV) of the polymer or oligomer having an acidic group such as a carboxyl group on the side chain thus obtained is preferably 50 to 180, more preferably 70 to 140. When the acid value is less than 50, the allowable development width becomes narrow. On the other hand, if the acid value exceeds 180, the solubility of the unexposed portion in the developing solution decreases, so that if the developing solution concentration is increased, peeling occurs up to the exposed portion, making it difficult to obtain a high-definition pattern.

By adding a photoreactive group to the side chain or molecular end of the above-mentioned polymer or oligomer, it can be used as a photosensitive polymer or photosensitive oligomer having photosensitivity.

Preferred photoreactive groups are those having an ethylenically unsaturated group. As the ethylenically unsaturated group,
Examples include a vinyl group, an allyl group, an acryl group, and a methacryl group.

The method of adding such a side chain to an oligomer or polymer is carried out by a method such as an ethylenically unsaturated compound having a glycidyl group or an isocyanate group or acrylic acid with respect to a mercapto group, an amino group, a hydroxyl group or a carboxyl group in the polymer. There is a method in which chloride, methacrylic acid chloride or allyl chloride is subjected to an addition reaction.

Examples of the ethylenically unsaturated compound having a glycidyl group include glycidyl acrylate, glycidyl methacrylate, allyl glycidyl ether, glycidyl ethyl acrylate, crotonyl glycidyl ether, crotonic acid glycidyl ether and isocrotonic acid glycidyl ether. .

Examples of the ethylenically unsaturated compound having an isocyanate group include (meth) acryloyl isocyanate and (meth) acryloyl ethyl isocyanate.

Further, the ethylenically unsaturated compound having a glycidyl group or an isocyanate group, acrylic acid chloride, methacrylic acid chloride or allyl chloride is used in an amount of 0.05 to 0.05 with respect to the mercapto group, amino group, hydroxyl group or carboxyl group in the polymer. It is preferable to add 1 molar equivalent.

As the photopolymerization initiator, a general photopolymerization initiator can be used in combination with the above-mentioned polymerization initiator which is sensitive to visible light.

Specific examples of the photopolymerization initiator include benzophenone, methyl o-benzoylbenzoate, 4,4-bis (dimethylamine) benzophenone, 4,4-bis (diethylamino) benzophenone and 4,4-dichlorobenzophenone. , 4-benzoyl-4-methyldiphenyl ketone, dibenzyl ketone, fluorenone, 2,2-
Diethoxyacetophenone, 2,2-dimethoxy-2-
Phenyl-2-phenylacetophenone, 2-hydroxy-2-methylpropiophenone, pt-butyldichloroacetophenone, thioxanthone, 2-methylthioxanthone, 2-chlorothioxanthone, 2-isopropylthioxanthone, diethylthioxanthone, benzyl, benzyldimethyl Ketanol, benzyl methoxyethyl acetal, benzoin, benzoin methyl ether, benzoin butyl ether, anthraquinone, 2-
t-butylanthraquinone, 2-amylanthraquinone, β-chloroanthraquinone, anthrone, benzanthrone, dibenzosuberone, methyleneanthrone, 4
-Azidobenzalacetophenone, 2,6-bis (p-
(Azidobenzylidene) cyclohexanone, 2,6-bis (p-azidobenzylidene) -4-methylcyclohexanone, 2-phenyl-1,2-butadione-2- (o-
Methoxycarbonyl) oxime, 1-phenyl-propanedione-2- (o-ethoxycarbonyl) oxime,
1,3-diphenyl-propanetrione-2- (o-ethoxycarbonyl) oxime, 1-phenyl-3-ethoxy-propanetrione-2- (o-benzoyl) oxime, Michler's ketone, 2-methyl- [4- (methylthio ) Phenyl] -2-morpholino-1-propanone,
Naphthalenesulfonyl chloride, quinolinesulfonyl chloride, N-phenylthioacridone, 4,4-azobisisobutyronitrile, diphenyldisulfide,
Benzthiazole disulfide, triphenylphosphine, camphorquinone, carbon tetrabromide, tribromophenyl sulfone, benzoin peroxide and eosin, a combination of photo-reducing dyes such as eosin and methylene blue with reducing agents such as ascorbic acid and triethanolamine Can be given. In the present invention, these may be used alone or in combination of two or more. The photopolymerization initiator, for the photosensitive component,
It is added in the range of 0.05 to 10% by weight, more preferably 0.1 to 5% by weight. If the amount of the polymerization initiator is too small, the photosensitivity becomes poor, and if the amount of the photopolymerization initiator is too large, the residual ratio of the exposed portion may be too small.

It is also effective to add an ultraviolet absorber. By adding a compound having a high ultraviolet absorption effect, a high aspect ratio, high definition, and high resolution can be obtained. UV absorbers composed of organic dyes, especially 35
Organic dyes having a high UV absorption coefficient in the wavelength range of 0 to 450 nm are preferably used. Specifically, azo dyes, aminoketone dyes, xanthene dyes, quinoline dyes, aminoketone dyes, anthraquinones, benzophenones, diphenylcyanoacrylates, triazines, p-aminobenzoic acid dyes and the like can be used. . Even when the organic dye is added as a light absorbing agent, it is preferable because deterioration of the insulating film characteristics due to the light absorbing agent can be reduced without remaining in the insulating film after firing. Among these, azo dyes and benzophenone dyes are preferred. The addition amount of the organic dye is preferably 0.05 to 5 parts by weight. When the content is less than 0.05% by weight, the effect of adding the ultraviolet absorber is reduced, and
Exceeding the range is not preferred because the properties of the insulating film after firing deteriorate. It is more preferably 0.05 to 1% by weight. To give an example of the method of adding an ultraviolet light absorber composed of an organic pigment, to prepare a solution in which the organic pigment was previously dissolved in an organic solvent,
In addition to the method of kneading it at the time of preparing a paste, a method of mixing inorganic fine particles in the organic solvent and then drying it can be mentioned. By this method, so-called capsule-shaped fine particles can be produced in which the surface of each of the inorganic fine particles is coated with an organic film.

In the present invention, P contained in the inorganic fine particles
Metals and oxides such as b, Fe, Cd, Mn, Co, and Mg may react with the photosensitive components contained in the paste, causing the paste to gel in a short time, making application impossible. In order to prevent such a reaction, it is preferable to add a stabilizer to prevent gelation. As the stabilizer used, a triazole compound is preferably used. As the triazole compound, a benzotriazole derivative is preferably used. Among them, benzotriazole works particularly effectively. As an example of the surface treatment of inorganic fine particles with benzotriazole used in the present invention, a predetermined amount of benzotriazole with respect to the inorganic fine particles was dissolved in an organic solvent such as methyl acetate, ethyl acetate, ethyl alcohol, and methyl alcohol. Thereafter, 1 to 24 are placed in a solution so that these fine particles can be sufficiently immersed.
Soak for hours. After immersion, preferably, the particles are naturally dried at 20 to 30 ° C., and the solvent is evaporated to produce triazole-treated fine particles. The ratio of the stabilizer used (stabilizer / inorganic fine particles) is preferably 0.05 to 5% by weight.

The sensitizer is added to improve the sensitivity. Specific examples of the sensitizer include 2,4-diethylthioxanthone, isopropylthioxanthone, 2,3-bis (4-diethylaminobenzal) cyclopentanone,
2,6-bis (4-dimethylaminobenzal) cyclohexanone, 2,6-bis (4-dimethylaminobenzal) -4-methylcyclohexanone, Michler's ketone,
4,4-bis (diethylamino) -benzophenone,
4,4-bis (dimethylamino) chalcone, 4,4-bis (diethylamino) chalcone, p-dimethylaminocinnamylidene indanone, p-dimethylaminobenzylidene indanone, 2- (p-dimethylaminophenylvinylene)- Isonaphthothiazole, 1,3-bis (4-
Dimethylaminobenzal) acetone, 1,3-carbonyl-bis (4-diethylaminobenzal) acetone,
3,3-carbonyl-bis (7-diethylaminocoumarin), N-phenyl-N-ethylethanolamine, N
-Phenylethanolamine, N-tolyldiethanolamine, N-phenylethanolamine, isoamyl dimethylaminobenzoate, isoamyl diethylaminobenzoate, 3-phenyl-5-benzoylthiotetrazole, 1-phenyl-5-ethoxycarbonylthiotetrazole and the like. Can be In the present invention, these may be used alone or in combination of two or more. Some sensitizers can also be used as photopolymerization initiators. When a sensitizer is added to the photosensitive paste of the present invention, the amount is usually 0.05 to 10% by weight, more preferably 0.1 to 10% by weight, based on the photosensitive component. If the amount of the sensitizer is too small, the effect of improving the photosensitivity is not exhibited, and if the amount of the sensitizer is too large, the residual ratio of the exposed portion may be too small.

The polymerization inhibitor is added to improve the heat stability during storage. Specific examples of the polymerization inhibitor include hydroquinone, monoesterified hydroquinone,
N-nitrosodiphenylamine, phenothiazine, p-
t-butylcatechol, N-phenylnaphthylamine,
2,6-di-t-butyl-p-methylphenol, chloranil, pyrogallol and the like. When adding a polymerization inhibitor, the amount added, in the photosensitive paste,
Usually, it is 0.001 to 1% by weight.

Specific examples of the plasticizer include dibutyl phthalate, dioctyl phthalate, polyethylene glycol, glycerin and the like.

The antioxidant is added to prevent oxidation of the acrylic copolymer during storage. Specific examples of antioxidants include 2,6-di-t-butyl-p-cresol, butylated hydroxyanisole, and 2,6-di-t.
-4-ethylphenol, 2,2-methylene-bis-
(4-methyl-6-t-butylphenol), 2,2-
Methylene-bis- (4-ethyl-6-t-butylphenol), 4,4-bis- (3-methyl-6-t-butylphenol), 1,1,3-tris- (2-methyl-6
-T-butylphenol), 1,1,3-tris- (2
-Methyl-4-hydroxy-t-butylphenyl) butane, bis [3,3-bis- (4-hydroxy-3-t-
[Butylphenyl) butyric acid] glycol ester, dilaurylthiodipropionate, triphenylphosphite and the like. When adding an antioxidant, the amount added is usually 0.001 to 1% by weight in the paste.

An organic solvent may be added to the photosensitive paste of the present invention when the viscosity of the solution is desired to be adjusted. As the organic solvent used at this time, methyl cellosolve, ethyl cellosolve, butyl cellosolve, methyl ethyl ketone, dioxane, acetone, cyclohexanone, cyclopentanone, isobutyl alcohol, isopropyl alcohol, tetrahydrofuran, dimethyl sulfoxide, γ-butyrolactone, bromobenzene, Chlorobenzene, dibromobenzene, dichlorobenzene, bromobenzoic acid, chlorobenzoic acid, and the like, and an organic solvent mixture containing one or more of these are used.

The refractive index of the organic component is the refractive index of the organic component in the paste when the photosensitive component is exposed to light by exposure. In other words, when the paste is applied and the exposure is performed after the drying step, it refers to the refractive index of the organic component in the paste after the drying step. For example, there is a method of applying a paste on a glass substrate, drying the paste at 50 to 100 ° C. for 1 to 30 minutes, and measuring the refractive index.

The measurement of the refractive index in the present invention is preferably performed by the commonly used ellipsometry method or V block method, and it is accurate to confirm the effect that the measurement is carried out at the wavelength of light for exposure. In particular, it is preferable to measure with light having a wavelength in the range of 400 to 900 nm. Furthermore, 46
Refractive index measurements at 6 nm or 488 nm are preferred.

Further, in order to measure the refractive index after the organic component is polymerized by light irradiation, the same light as in the case of irradiating light into the paste can be measured by irradiating only the organic component.

Glass fine particles containing bismuth oxide or lead oxide in an amount of 10% by weight or more, which can be baked on a glass substrate, may have a refractive index of 1.6 or more. It needs to be high.

In this case, it is necessary to introduce a high refractive index component into the organic component, and a sulfur atom, a bromine atom,
It is effective to use a compound having an iodine atom, a naphthalene ring, a biphenyl ring, an anthracene ring, and a carbazole ring in an amount of 10% by weight or more to increase the refractive index. Further, by containing 20% by weight or more of the benzene ring, the refractive index can be increased.

Particularly, a sulfur atom or a naphthalene ring is
When the content is 0% by weight or more, the refractive index of the organic component can be more easily increased. However, if the content is 6
When the content is more than 0% by weight, a problem that the photosensitivity is reduced occurs, so that the total content of the sulfur atom and the naphthalene ring is 1%.
It is preferably in the range of 0 to 60% by weight.

As a method of introducing a sulfur atom, a bromine atom or a naphthalene ring into the organic component, it is effective to use a compound having a sulfur atom or a naphthalene ring in the photosensitive monomer or the binder. Examples of the monomer containing a sulfur atom in the molecule include compounds represented by the following general formula (A), (B) or (C). R in the structural formula represents a hydrogen atom or a methyl group.

[0077]

Embedded image Further, as the sensitizer, one having absorption at the exposure wavelength is used. In this case, the refractive index becomes extremely high near the absorption wavelength, so by adding a large amount of sensitizer,
The refractive index of the organic component can be improved. In this case, the sensitizer may be added in the paste in an amount of 0.5 to 10% by weight. More preferably, it is 1 to 6% by weight.

The photosensitive paste is usually prepared by mixing various components such as inorganic fine particles, an ultraviolet light absorber, a photosensitive polymer, a photosensitive monomer, a photopolymerization initiator, a glass frit and a solvent so as to have a predetermined composition. It is prepared by uniformly mixing and dispersing with three rollers or a kneader.

The viscosity of the paste is appropriately adjusted by the addition ratio of the inorganic fine particles, the thickener, the organic solvent, the plasticizer and the suspending agent, and the range is 2000 to 200,000 cp.
s (centipoise). For example, when coating on a glass substrate is performed by a spin coating method,
cps is preferred. In order to obtain a film thickness of 10 to 20 μm by applying once by a screen printing method, 50,000 to 200,000 cps is preferable. When a blade coater method, a die coater method, or the like is used, 2000 to 20000 cps is preferable.

Next, an example of performing pattern processing using a photosensitive paste will be described, but the present invention is not limited to this. A photosensitive paste is applied entirely or partially on a glass substrate, a ceramic substrate, or a polymer film. As the application method,
General methods such as screen printing, a bar coater, a roll coater, a die coater, and a blade coater can be used. The coating thickness can be adjusted by selecting the number of coatings, the coater gap, the screen mesh, and the viscosity of the paste.

Here, when the paste is applied to the substrate,
Surface treatment of the substrate can be performed to enhance the adhesion between the substrate and the coating film. Examples of the surface treatment liquid include silane coupling agents such as vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, and tris-silane.
(2-methoxyethoxy) vinylsilane, γ-glycidoxypropyltrimethoxysilane, γ- (methacryloxypropyl) trimethoxysilane, γ (2-aminoethyl) aminopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane and the like or organic metals such as organic titanium, organic aluminum and organic zirconium. The silane coupling agent or the organic metal is dissolved in an organic solvent, for example, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, methyl alcohol, ethyl alcohol, propyl alcohol, butyl alcohol or the like.
Use the one diluted to a concentration of 1 to 5%. Next, after applying this surface treatment liquid uniformly on the substrate with a spinner or the like, 8
Surface treatment can be performed by drying at 0 to 140 ° C. for 10 to 60 minutes.When applied on a film, after drying on the film, performing the next exposure step,
There is a method in which an exposure step is performed after the film is pasted on a glass or ceramic substrate.

A photosensitive green sheet used for a circuit material or a display can be obtained by applying the photosensitive paste of the present invention onto a polyester film or the like.

After application, exposure is performed using an exposure apparatus. The exposure is generally performed by mask exposure using a photomask as in ordinary photolithography, but in the case of the present invention, direct drawing exposure using a visible light laser or the like without using a photomask. The method of doing can also be used conveniently.

In this case, a semiconductor laser, a visible light laser or the like can be used as the light source. As the visible light laser, an argon ion laser or the like can be used, and since a photomask is not used, troubles caused by the mask can be suppressed.

For mask exposure, either a negative type or a positive type is selected as the mask to be used, depending on the type of the photosensitive organic component. As the exposure device, a stepper exposure device, a proximity exposure device, or the like can be used.

The pattern shape can be improved by providing an oxygen shielding film on the surface of the applied photosensitive paste. As an example of the oxygen shielding film, a film such as PVA or cellulose, or a film such as polyester is used.

The PVA film is formed by uniformly applying an aqueous solution having a concentration of 0.5 to 5% by weight onto a substrate by a method such as a spinner and then drying at 70 to 90 ° C. for 10 to 60 minutes to evaporate water. Let me do it. In addition, it is preferable to add a small amount of alcohol to the aqueous solution because the coatability with the insulating film is improved and the evaporation is facilitated. A more preferable PVA solution concentration is 1 to 3% by weight. Within this range, the sensitivity is further improved. It is estimated that the reason why the PVA coating improves the sensitivity is as follows. That is, when the photosensitive component undergoes a photoreaction, it is considered that oxygen in the air interferes with the sensitivity of photocuring, but the presence of a PVA film can block excess oxygen, so the sensitivity is considered to improve during exposure. .

When a transparent film of polyester, polypropylene, polyethylene or the like is used, there is also a method of sticking these films on the photosensitive paste after coating.

After the exposure, the development is carried out by utilizing the difference in solubility between the exposed portion and the non-exposed portion in the developing solution. In this case, the dipping method, the spray method or the brush method is used.

As the developer used, an organic solvent in which the organic components in the photosensitive paste can be dissolved can be used. Water may be added to the organic solvent as long as the solvent does not lose its solubility. When a compound having an acidic group such as a carboxyl group is present in the photosensitive paste, development can be performed with an aqueous alkali solution. As the alkaline aqueous solution, a metallic alkaline aqueous solution such as sodium hydroxide, sodium carbonate, calcium hydroxide aqueous solution, etc. can be used, but it is preferable to use an organic alkaline aqueous solution since the alkaline component can be easily removed during firing.

As the organic alkali, a general amine compound can be used. Specific examples include tetramethylammonium hydroxide, trimethylbenzylammonium hydroxide, monoethanolamine, diethanolamine and the like. The concentration of the alkaline aqueous solution is usually 0.01 to 10% by weight, more preferably 0.1 to 10% by weight.
~ 5% by weight. If the alkali concentration is too low, the soluble portion is not removed, and if the alkali concentration is too high, the pattern portion may be peeled off and the non-soluble portion may be corroded, which is not preferable. The development temperature during development is preferably 20 to 50 ° C. for process control.

Next, firing is performed in a firing furnace. The firing atmosphere and temperature vary depending on the type of the paste and the substrate, but firing is performed in an atmosphere of air, nitrogen, hydrogen, or the like. As the firing furnace, a batch-type firing furnace or a belt-type continuous firing furnace can be used. The firing temperature is 400 to 1000 ° C. When patterning on a glass substrate, 520-
Baking is performed by holding at a temperature of 610 ° C. for 10 to 60 minutes.

A heating step at 50 to 300 ° C. may be introduced for the purpose of drying and preliminary reaction during each of the coating, exposure, development and baking steps.

[0094]

The present invention will be specifically described below with reference to examples. However, the present invention is not limited to this. The concentrations (%) in Examples and Comparative Examples are% by weight unless otherwise specified.

In the example, a photosensitive paste composed of inorganic fine particles and an organic component was prepared. The preparation procedure was as follows. First, each component of the organic component was melted while heating at 80 ° C., then inorganic fine particles were added and kneaded with a kneader to prepare a paste. The viscosity was adjusted by adjusting the amount of solvent. The amount of solvent (γ-butyl lactone) is 10 in the paste.
Adjusted to be ~ 40%.

Next, a 30 cm square soda glass substrate or a quartz glass substrate was coated multiple times by screen printing to a coating thickness of 100 μm, and then dried at 80 ° C. for 30 minutes.

Next, scanning exposure was performed using a 488 nm water-cooled argon ion laser (GLG3028 manufactured by NEC Corporation). The pattern has a pitch of 300 μm and a line width of 100
It was set so that a stripe-shaped partition wall pattern could be formed in a plasma display. After exposure,
Curing was performed at 80 ° C. for 30 minutes. Then, it was immersed in a 1% aqueous solution of sodium carbonate for development.

Further, the obtained glass substrate was dried at 120 ° C. for 1 hour and then baked at a predetermined temperature for 1 hour.
The firing causes a shrinkage of about 20%.

The evaluation was performed on the pattern shape (line width: about 80 μm,
A target having a height of about 80 μm and a pitch of 300 μm was observed by an electron microscope. When the good shape was obtained, it was evaluated as ◯, and when the good shape was not obtained due to lack or the like, it was evaluated as x.

The refractive index of the organic component is 488 nm at 25 ° C. by the ellipsometry method after adjusting the organic component in the paste and applying and drying.
The measurement was performed for light having a wavelength of. The paste composition shown in the examples is the composition during the exposure step (after the drying step). The composition before drying is the composition ratio in the table except that the amount of γ-butyl lactone as a solvent is 15% in the paste.

Examples 1 and 2 Using the photosensitive paste having the composition shown in Table 1, patterns were formed. The firing was performed at 560 ° C.

[0102]

[Table 1] Abbreviations in the table are shown below.

(The numbers in the structure of the polymer 1 indicate the constituent molar ratios of the respective monomers) TMPTA: trimethylolpropane triacrylate BMEXS-MA:

Embedded image Erythrosin:

Embedded image IGC261:

Embedded image BMPS:

Embedded image γ-BL: γ-butyrolactone Polymer 1:

[Chemical 6]

[0104]

According to the photosensitive paste of the present invention, pattern processing with a high aspect ratio and high precision can be performed. As a result, a thick film such as a display or a circuit material, and a high-precision pattern processing can be performed, and the definition can be improved and the process can be simplified.

In particular, it is possible to easily and easily form a partition wall of a high-precision plasma display panel.

Claims (15)

[Claims] 1. A photosensitive paste comprising an organic component containing a photosensitive compound, inorganic fine particles, and a visible light-sensitive polymerization initiator as essential components. 2. The photosensitive paste according to claim 1, wherein the content of each component is as shown below. Organic component containing photosensitive compound: 5 to 40 parts by weight Inorganic fine particles: 60 to 95 parts by weight Visible light photosensitive polymerization initiator: 0.05 to 5 parts by weight 3. The photosensitive paste according to claim 1, wherein the wavelength of visible light is 400 to 900 nm. 4. The photosensitive paste according to claim 1, wherein the organic component contains 10 to 90% by weight of an oligomer or polymer having a carboxyl group in the molecule and having a weight average molecular weight of 500 to 100,000. 5. The photosensitive paste according to claim 1, wherein the organic component contains 10 to 90% by weight of an oligomer or polymer having an unsaturated double bond in the molecule and having a weight average molecular weight of 500 to 100,000. . 6. A weight average molecular weight of the organic component containing a carboxyl group and an unsaturated double bond in the molecule of 500 to 10
The photosensitive paste according to claim 1, comprising 10 to 90% by weight of various oligomers or polymers. 7. The photosensitive paste according to claim 1, wherein the organic component contains an organic dye in an amount of 0.05 to 5% by weight. 8. The photosensitive paste according to claim 1, wherein the inorganic fine particles are glass fine particles. 9. The average refractive index of the inorganic fine particles is from 1.5 to 1.
The photosensitive paste according to claim 1, wherein the photosensitive paste is 65. 10. The average refractive index N of the inorganic fine particles in the paste
The photosensitive paste according to claim 1, wherein a paste satisfying the following formula with respect to 1 and the average refractive index N2 of the organic component is used. 0.01 <N1-N2 <0.07 11. A glass softening agent having a heat softening temperature of 35.
9. The photosensitive paste according to claim 8, wherein glass fine particles of 0 to 600 ° C. are used. 12. The photosensitive material according to claim 8, wherein glass fine particles containing at least one of bismuth oxide and lead oxide and having a total content of 5 to 50% by weight are used. paste. 13. A glass fine particle containing at least one of lithium oxide, sodium oxide and potassium oxide, and having a total content of 3 to 20% by weight is used as the glass fine particle. Photosensitive paste of. 14. A glass fine particle having a linear thermal expansion coefficient of 6
Photosensitive paste according to claim 8, characterized by using glass particles of 0 to 90 × 10 ^-7. 15. The photosensitive paste according to claim 1, which is used for forming a pattern of a plasma display.