JPH1062981A - Pattern forming paste - Google Patents

Abstract

PROBLEM TO BE SOLVED: To precisely form a pattern having a high aspect ratio (thickness/ width) such as the barrier of a plasma display panel by using pattern forming paste contg. a photosensitive resin and inorg. powder including a specified percentage or more of inorg. powder whose refractive index is different from that of the resin within a specified value. SOLUTION: This pattern forming paste contains a photosensitive resin and inorg. powder including >=80wt.% inorg. powder whose refractive index is different from that of the resin by <=0.2, preferably <=0.15. When a pattern is formed using this paste, the scattering of radiated light is suppressed at the time of exposure and light transmittance is increased. In the case of a difference of >0.2 or <80wt.% inorg. powder whose refractive index is different from that of the resin by <=0.2, light is scattered and light transmittance is not sufficiently high at the time of the exposure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paste for forming a pattern, and more particularly to a paste for forming a pattern for forming a pattern having a large ratio of thickness to width.

[0002]

2. Description of the Related Art In recent years, pattern formation of electrodes, resistors, dielectrics, and the like in electronic devices such as integrated circuits and image display devices has been performed.
Alternatively, formation of a barrier pattern in a plasma display panel (PDP) requires higher accuracy.

For example, the barrier in the above-mentioned PDP is cut perpendicularly to the glass substrate and has a small width and a sufficient height in order to make the display discharge space as large as possible and to emit light with high luminance. Is required. In particular, in a high-definition PDP, for example, a barrier having a high aspect ratio such that the thickness is about 100 μm for a width of 30 to 50 μm is required.

Conventionally, as a pattern having a high aspect ratio such as the barrier described above, a photosensitive pattern forming paste is applied to a substrate, and this applied film is exposed and developed through a predetermined mask, and then fired. There is known a method of forming a pattern by removing organic components.

[0005]

SUMMARY OF THE INVENTION However, PDP
When forming a pattern with a large height like a barrier,
A conventional coating film made of a paste for forming a pattern has a large thickness and thus has a low light transmittance, and light irradiated during exposure of the coating film is scattered in the coating film, and the base of the formed pattern is thickened. However, there is a problem that it is difficult to form a pattern with high edge precision at a high aspect ratio.

In order to solve such a problem, measures such as reducing the width of the mask in advance in consideration of the thickness of the pattern and performing anisotropic development in development after exposure have been made. However, the operation is complicated, and the aspect ratio and the edge accuracy are insufficient.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and has been developed for forming a pattern having a large thickness-to-width aspect ratio, such as a barrier of a plasma display panel, with high precision. It is intended to provide a paste.

[0008]

In order to achieve the above object, the pattern forming paste of the present invention contains at least one kind of inorganic powder and a photosensitive resin component. The structure was such that the inorganic powder having a refractive index such that the difference from the refractive index was within 0.2 accounted for 80% by weight or more of the inorganic powder.

In the pattern forming paste of the present invention, 80% by weight or more of the contained inorganic powder is
The refractive index is a difference of not more than 0.2 from the refractive index of the photosensitive resin component, and the scattering of the irradiation light in the exposure at the time of pattern formation is suppressed, and therefore, the transmittance of the irradiation light is high.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The preferred embodiments of the present invention will be described below.

The pattern forming paste of the present invention contains at least one kind of inorganic powder and a photosensitive resin component.

At least 80% by weight of the inorganic powder constituting the pattern forming paste of the present invention has a refractive index difference between the refractive index of the photosensitive resin component within 0.2, preferably within 0.15. Occupied by those with rates When the difference between the refractive index of the photosensitive resin component and the refractive index of the photosensitive resin component exceeds the above range, or when the difference between the refractive index of the photosensitive resin component and the inorganic powder in the above range is less than 80% by weight, The light irradiated to the pattern forming paste is scattered in the paste, and the transmittance of the irradiated light at the time of exposure is insufficient, which is not preferable.

The inorganic powder used has a softening temperature of 3
An inorganic powder having a temperature of 50 to 650 ° C is preferred. If the softening temperature of the inorganic powder exceeds 650 ° C., it is necessary to increase the firing temperature. For example, if the heat resistance of the substrate is low, the substrate is undesirably thermally deformed at the firing stage. If the softening temperature of the inorganic powder is lower than 350 ° C., the inorganic powder is fused before the resin component of the pattern forming paste is completely decomposed and volatilized. Specific examples of the inorganic powder that can be used include glass frit and ceramic powder, for controlling firing shrinkage, adjusting the softening temperature, and adjusting the thermal expansion coefficient to the glass substrate. Al ₂ O ₃ , B ₂
O ₃ , SiO ₂ , TiO ₂ , MgO, CaO, SrO,
An inorganic powder such as BaO is used.

The average particle size of the glass frit as the above inorganic powder is preferably in the range of 0.1 to 10 μm.
The average particle size of the ceramic powder is preferably in the range of 0.02 to 10 μm.

Such an inorganic powder can be contained in the pattern forming paste in an amount of 50 to 95% by weight, preferably 60 to 85% by weight.

The photosensitive resin component constituting the pattern forming paste of the present invention is a negative type or a novolak type positive type containing an alkali developing type binder polymer, a monomer and an initiator, and is fired at a low temperature of 650 ° C. or lower. It does not volatilize and decompose to leave carbide in the pattern.

Examples of the alkali developing type binder polymer include acrylic acid, methacrylic acid, a dimer of acrylic acid (for example, M-5600 manufactured by Toa Gosei Chemical Co., Ltd.), itaconic acid, crotonic acid, maleic acid, fumaric acid, Vinyl acetic acid, one or more of these acid anhydrides, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, n-propyl acrylate, n-propyl methacrylate, isopropyl acrylate, isopropyl methacrylate, n-butyl acrylate,
n-butyl methacrylate, sec-butyl acrylate,
sec-butyl methacrylate, isobutyl acrylate,
Isobutyl methacrylate, tert-butyl acrylate, tert-butyl methacrylate, n-pentyl acrylate, n-pentyl methacrylate, n-hexyl acrylate, n-hexyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, n-octyl acrylate, n- And copolymers of at least one of octyl methacrylate, n-decyl acrylate, n-decyl methacrylate, styrene, α-methylstyrene, and 1-vinyl-2-pyrrolidone.

Further, there may be mentioned, for example, polymers obtained by adding an ethylenically unsaturated compound having a glycidyl group or a hydroxyl group to the above-mentioned copolymer, but it is not limited thereto.

Incidentally, a non-alkali developing type polymer may be mixed with the above-mentioned alkali developing type binder polymer.
Examples of the non-alkali development type polymer include polyvinyl alcohol, polyvinyl butyral, acrylate polymer, methacrylate polymer, polystyrene, α
-Methylstyrene polymer, 1-vinyl-2-pyrrolidone polymer, and copolymers thereof.

As the reactive monomer constituting the photosensitive resin component, a compound having at least one polymerizable carbon-carbon unsaturated bond can be used. Specifically, allyl acrylate, benzyl acrylate, butoxyethyl acrylate, butoxyethylene glycol acrylate, cyclohexyl acrylate, dicyclopentanyl acrylate, 2-ethylhexyl acrylate, glycerol acrylate, glycidyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl Acrylate, isobonyl acrylate,
Isodexyl acrylate, isooctyl acrylate, lauryl acrylate, 2-methoxyethyl acrylate, methoxyethylene glycol acrylate, phenoxyethyl acrylate, stearyl acrylate, ethylene glycol diacrylate, diethylene glycol diacrylate, 1,4-butanediol diacrylate, 1, 5-pentanediol diacrylate, 1,6-hexanediol diacrylate, 1,3
-Propanediol acrylate, 1,4-cyclohexanediol diacrylate, 2,2-dimethylolpropane diacrylate, glycerol diacrylate,
Tripropylene glycol diacrylate, glycerol triacrylate, trimethylolpropane triacrylate, polyoxyethylated trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, triethylene glycol diacrylate, polyoxypropyl trimethylolpropane triacrylate , Butylene glycol diacrylate, 1,2,4-butanetriol triacrylate, 2,2,4-trimethyl-1,
3-pentanediol diacrylate, diallyl fumarate, 1,10-decanediol dimethyl acrylate, pentaerythritol hexaacrylate, and those obtained by changing the above acrylate to methacrylate, γ-methacryloxypropyltrimethoxysilane,
1-vinyl-2-pyrrolidone and the like. In the present invention, the above-mentioned reactive monomers can be used as one kind or a mixture of two or more kinds, or as a mixture with other compounds.

Examples of the photopolymerization initiator constituting the photosensitive resin component include benzophenone, methyl o-benzoylbenzoate, 4,4-bis (dimethylamine) benzophenone,
4,4-bis (diethylamine) benzophenone, α-
Amino acetophenone, 4,4-dichlorobenzophenone, 4-benzoyl-4-methyldiphenyl ketone,
Dibenzyl ketone, fluorenone, 2,2-diethoxyacetophonone, 2,2-dimethoxy-2-phenylacetophenone, 2-hydroxy-2-methylpropiophenone, p-tert-butyldichloroacetophenone, thioxanthone, 2-methyl Thioxanthone, 2-chlorothioxanthone, 2-isopropylthioxanthone, diethylthioxanthone, benzyldimethylketal, benzylmethoxyethylacetal, benzoin methyl ether, benzoin butyl ether, anthraquinone,
2-tert-butylanthraquinone, 2-amylanthraquinone, β-chloroanthraquinone, anthrone, benzanthrone, dibensuberone, methyleneanthrone, 4-azidobenzylacetophenone, 2,6-bis (p-azidobenzylidene) cyclohexane, 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-propane, naphthalenesulfonyl chloride, quinoline sulfonyl chloride, n-phenylthioacridone,
4,4-azobisisobutyronitrile, diphenyl disulfide, benzthiazole disulfide, triphenylphosphine, camphorquinone, carbon tetrabromide, tribromophenylsulfone, benzoin peroxide, eosine, methylene blue Examples include a combination of reducing agents such as ascorbic acid and triethanolamine. In the present invention, one or more of these photopolymerization initiators can be used.

Further, a positive resist can be used as the photosensitive resin component. Specific positive resists include O
FPR series (manufactured by Tokyo Ohka Kogyo Co., Ltd.), PFR30
Novolak-based resists such as No. 03 (manufactured by Nippon Synthetic Rubber Co., Ltd.), NPR9100 (manufactured by Nagase Electronic Chemical Co., Ltd.) and AZ-1350 (manufactured by Hoechst Co., Ltd.).

If the volatilization and decomposition temperature of the photosensitive resin component exceeds 650 ° C., the firing temperature for removing the resin component after exposure and development becomes high. For example, when the heat resistance of the substrate is low, Undesirably, thermal deformation occurs. On the other hand, the lower limit of the volatilization and decomposition temperature of the photosensitive resin component is not particularly limited. It is preferable to set the lower limit of the volatilization and decomposition temperature of the photosensitive resin component to about 300 ° C.

The content of such a photosensitive resin component in the pattern forming paste can be in the range of 5 to 50% by weight, preferably 10 to 40% by weight.

The paste for pattern formation of the present invention is prepared by mixing the above-mentioned inorganic powder and the photosensitive resin component in a solvent and kneading them by a roll mill to form a paste-like coating solution, or kneading them by a ball mill or the like. To obtain a slurry-like coating solution. Further, in the pattern forming paste of the present invention, as an additive, a sensitizer, a polymerization terminator,
A chain transfer agent, a leveling agent, a dispersant, a plasticizer, a stabilizer and the like are used as needed. Examples of the solvent used for the pattern forming paste include, for example, anones such as methanol, ethanol, isopropanol, acetone, methyl ethyl ketone, toluene, xylene, cyclohexanone, methylene chloride, 3-methoxybutyl acetate, ethylene glycol monoalkyl ethers, and ethylene glycol. Examples thereof include dialkyl ethers, diethylene glycol monoalkyl ethers, diethylene glycol monoalkyl ether acetates, and terpenes such as α- or β-terpineol.

[0026]

Next, the present invention will be described in more detail with reference to examples. Example 1 First, a photosensitive resin having the following composition was prepared. The refractive index of the prepared photosensitive resin was 1.54.

(Composition of photosensitive resin) α-methylstyrene / styrene / methacrylic acid copolymer: 100 parts by weight Oxyethylenated trimethylolpropane triacrylate: 70 parts by weight Polymerization initiator (manufactured by Ciba-Geigy Co., Ltd.) Irgacure 369) ... 10 parts by weight In addition, three types of glass frits (glass frits A to C, average particle size = 4 µm) having the following compositions were produced.

[0028] (composition of the glass frit A (refractive index 1.63)) · SiO ₂ ... 33 parts by weight · K ₂ O ... 9 parts by weight · PbO ... 58 parts by weight (Composition of glass frit B (refractive index 1.67 )) · SiO ₂ ... 47 parts by weight · ZnO ... 8 parts · Al ₂ O ₃ ... 8 parts by weight · BaO ... 6 parts · B ₂ O ₃ ... 18 parts by weight · Li ₂ O ... 11 parts by weight (glass frit C composition (refractive index _{1.90)) · B 2 O 3} ... 82 parts by weight · SiO ₂ ... 5 parts by weight · ZnO ... 11 parts by weight · Al ₂ O ₃ ... ₃ parts by weight further, alumina ceramic powder ( Al ₂ O
₃ ) Powder (refractive index = 1.52) and titanium oxide (Ti
O ₂ ) powder (refractive index = 2.10) was prepared.

Next, a paste for forming a pattern (samples 1 to 7) having the following composition was prepared using the above photosensitive resin, glass frit, and ceramic powder. The glass frit used for each sample and the content of glass frit (X
Parts by weight), and the used ceramic powder and the content of the ceramic powder (Y parts by weight) are shown in Table 1 below.

(Composition of Pattern Forming Paste) Photosensitive resin: 20 parts by weight Glass frit: X parts by weight Ceramic powder: Y parts by weight Ethyl cellosolve: 20 parts by weight Each of the above pattern forming pastes (samples) 1) to 7) were applied on a glass substrate by a blade coating method and dried to form a coating film having a thickness of 150 μm. Next, a line width of 25 μm
After irradiating with ultraviolet light through a mask having a slit, the film was developed using a 1% aqueous solution of Na ₂ CO ₃ . Next, firing was performed at a peak temperature of 580 ° C. (peak temperature holding time: 10 minutes) to form a pattern. The line width of this pattern and the aspect ratio of the thickness to the line width are shown in Table 1 below.

[0031]

[Table 1] As shown in Table 1, the refractive index (1.
54) A pattern forming paste (samples 1 to 4) in which inorganic powders (glass frit and alumina powder) having a refractive index such that the difference from the above (54) is within 0.2 or less account for 80% by weight or more of the entire inorganic powder Then, the line width of the formed pattern is 45 to 5
5 μm, and the aspect ratio of the thickness to the line width was 1.8 to 2.2, indicating a good pattern. In particular, the difference from the refractive index (1.54) of the photosensitive resin component is 0.
The inorganic powder having a refractive index within 1 is 8 of the total inorganic powder.
With the pattern forming paste occupying 0% by weight or more (sample 1), it was possible to form a pattern with a greater depth.

On the other hand, inorganic powders (glass frit A, B) having a refractive index such that the difference from the refractive index (1.54) of the photosensitive resin component is within 0.2 are all inorganic powders. And the pattern forming paste having a ratio of less than 80% by weight (samples 5 and 6) and the refractive index of the photosensitive resin component and the refractive index of the photosensitive resin component (1.54) are not less than 80% by weight of the inorganic powder.
In the pattern forming paste (sample 7) having a difference of more than 0.2 (glass frit C), the irradiated ultraviolet rays are scattered, and the line width of the formed pattern is 85 to 120 μm. The aspect ratio of the thickness to the line width was as small as 0.8 to 1.2, and it was difficult to form a good pattern with a large depth. (Example 2) Positive photosensitive resin (OFPR-5000 manufactured by Tokyo Ohka Kogyo Co., Ltd., refractive index 1.57), glass frit B (refractive index 1.67) used in Example 1 and alumina powder ( A paste for pattern formation having the following composition was prepared using a refractive index of 1.52).

(Composition of Pattern Forming Paste) Positive photosensitive resin: 100 parts by weight Glass frit B: 70 parts by weight Alumina powder: 10 parts by weight Same as Example 1 using this pattern forming paste To form a coating film having a thickness of 150 μm on a glass substrate.
Next, after irradiating with ultraviolet rays through a mask having a slit having a line width of 25 μm to perform exposure, development is performed using tetramethylammonium hydroxide (manufactured by Tokyo Ohka Kogyo Co., Ltd.), and pure water is used. Washed. Then
Baking at a peak temperature of 580 ° C (peak temperature holding time 10
Min) to form a pattern. The line width of this pattern is 5
0 μm, and the aspect ratio of the thickness to the line width was 2.2, which was a good pattern.

[0034]

As described above in detail, in the pattern forming paste containing at least one kind of inorganic powder and the photosensitive resin component, 80% by weight or more of the inorganic powder is defined as the refractive index of the photosensitive resin component. Since the refractive index is such that the difference is within 0.2, the scattering of irradiation light in the exposure at the time of pattern formation is suppressed, and the transmittance is greatly improved. It is possible to form a pattern having a large thickness arrest ratio (a pattern having a large depth) with high accuracy.

Claims (1)

[Claims] 1. A photosensitive resin composition comprising at least one inorganic powder and a photosensitive resin component, wherein the difference between the refractive index of the photosensitive resin component and the photosensitive resin component is 0.
An inorganic powder having a refractive index of 2 or less accounts for 80% by weight or more of the inorganic powder.