JPH1152572A - Photosensitive resin composition and pattern forming method by using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a photosensitive resin composition capable of forming a pattern superior in heat resistance and electric and mechanical properties on a substrate low in heat resistance by containing a polymide resin soluble in an organic solvent and a specified photopolymerizable unsaturated compound. SOLUTION: This photosensitive resin composition contains the polyimide resin soluble in an organic solvent the photopolymerizable unsaturated compound and a photoppolymerization initiator. The photopolymerizable unsaturated compound is an epoxy acrylate or (meth)acrylic acid having >=3 (meth)acryloyl groups in one molecule. The polyimide resin is, preferably, the ones obtainable from aromatic tetracarboxylic acids and aromatic diamines, for example, the polyimide resin having benzophenonetetracarboxylic acid residues as constituents represented by the formula in which X is an optionally substituted arylene group.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a photosensitive resin composition and a pattern forming method using the same. More specifically, the present invention relates to a photosensitive resin composition which does not require heat treatment for ring-closing polymerization of a polyimide resin after exposure, and can be used as it is for an insulating material or the like after exposure, and a pattern forming method using the same. The pattern obtained by the photosensitive resin composition of the present invention has excellent heat resistance and also excellent electrical and mechanical properties. Further, since the pattern can be formed on a substrate having low heat treatment temperature and low heat resistance for forming a pattern, the applicable range can be widened. The pattern obtained by the photosensitive resin composition of the present invention is, for example, an interlayer insulating film of a high-density multilayer substrate in the electronics industry, a passivation film of a semiconductor element, a buffer coat film and an interlayer insulating film, and a protective film of electronic components and circuits. Suitable for use.

[0002]

2. Description of the Related Art In recent years, in the electronics industry, polyimide resins have attracted attention as protective films for electronic components and circuits, high-density multilayer substrates, and interlayer insulating films for semiconductor devices. This is because the polyimide resin has excellent heat resistance, insulation properties, and toughness, and can easily form a flat and thick film. In general, a polyimide resin is obtained by a method of polymerizing a diamine and a tetracarboxylic dianhydride in an organic solvent to generate a polyamic acid, and subjecting the polyamic acid to dehydration and ring closure. For example, 4,4′-diaminophenyl ether and the like are known as diamines, and pyromellitic dianhydride and the like are known as tetracarboxylic dianhydrides.

The organic solvents used in the above polymerization include:
N-methyl-2-pyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, dimethylsulfoxide, tetramethylene sulfone, p-chlorophenol, p-bromophenol, hexamethylphosphoramide, tetrahydrofuran, dioxane, triglyme , Γ─butyrolactone, butyrolactam and the like.

When a polyimide resin is used as an interlayer insulating film, it is necessary to form a pattern such as a through hole in the interlayer insulating film made of the polyimide resin. As a method for forming a pattern, an etching method using a photoresist is generally known. The etching method is performed as follows. First, a varnish obtained by dissolving a polyamic acid, which is a precursor of a polyimide resin, in an organic solvent is applied to a predetermined substrate using a technique such as a spin coater, and the organic solvent is removed to form a coating film. Next, a positive photoresist is applied on the coating film and dried, and a desired pattern is exposed. Thereafter, the development of the photoresist and the etching of the polyamic acid are simultaneously performed using an aqueous alkali solution such as an aqueous tetramethylammonium hydroxide solution to form a desired pattern. Thereafter, the photoresist is stripped using an organic solvent that does not dissolve the polyamic acid. Finally, by heat treatment, the polyamic acid is imidized,
A pattern of a polyimide resin is formed.

The high-density multilayer substrate is formed by repeatedly performing the above-described interlayer insulating film forming step and the conductor pattern forming step. In the etching step, a non-photosensitive polyamic acid is used. Since the non-photosensitive polyamic acid requires a pattern formation step using a photoresist, there is a problem that the steps are complicated and the production cost is increased.

In order to solve the above-mentioned problems, various varnishes containing polyamic acid have photosensitivity and are capable of forming fine patterns. As the photosensitive varnish, for example, a varnish containing a polyamic acid having a photosensitive functional group in the molecule (Japanese Patent Laid-Open No. 59-68)
332, JP-A-60-37550, JP-A-1-59
No. 289) and a varnish mixed with a compound having a photosensitive functional group (JP-A-57-102926, JP-A-63-102926).
No. 175854) is known. These varnishes are
In any case, the solubility of the exposed portion and the unexposed portion can be changed by photoreacting only the exposed portion. Next, the unexposed portions are removed by a developing process, and the exposed portions are left.
Finally, by subjecting it to a heat treatment to remove the photosensitive functional group having poor heat resistance and allow the imidization reaction to proceed,
A film made of a polyimide resin can be formed.

[0007]

The use of the above-mentioned photosensitive varnish can simplify the complicated steps when using a non-photosensitive polyamic acid. There is a problem that a phenomenon called so-called "film reduction" occurs in which the formed film becomes thinner due to the reduction of the volume of the resin component due to the elimination of the functional group. This reduction in film has caused problems of deteriorating step coverage and increasing residual stress.

Further, when a photosensitive group is provided in the molecule of a polyamic acid by a chemical reaction, the properties of the obtained resin may be modified by heat or pressure during the chemical reaction. In addition, there is a problem that it is necessary to increase the number of purification steps because there is a possibility that by-products may be generated or foreign substances may be mixed during the chemical reaction. Further, there is also a problem that the photosensitive varnish is expensive because it is manufactured by a complicated process.

Further, the polyamic acid must be subjected to a heat treatment for an imidization reaction, and the temperature of the heat treatment is high, so that a substrate on which a film made of a polyimide resin is formed must have high heat resistance. Problem. Further, when an electronic component or the like is formed on the base material, there is a problem that the heat treatment adversely affects the electronic component. Furthermore, the carboxyl group constituting the polyamic acid generally has a high reactivity to copper used for wiring, and the carboxyl group reacts with copper ions to modify the polyimide resin obtained, so that the original properties cannot be obtained. It is known. This modification of the polyimide resin occurs remarkably when a photosensitive varnish is used, and there has been a problem that a via hole or the like cannot be formed.

[0010] Therefore, a method is known in which a reaction between a carboxyl group and copper is prevented by applying another metal called a barrier metal on copper to prevent direct contact between the copper and the polyamic acid. . However, the formation of the barrier metal causes a problem that the number of steps for forming the polyimide resin increases and the manufacturing cost also increases.

[0011]

Means for Solving the Problems The present inventors have found that if a polyimide resin which is soluble in an organic solvent is used without using a polyamic acid, a high temperature treatment for an imidization reaction becomes unnecessary, and The present inventors have found that a film made of a polyimide resin can be formed by applying a heat treatment at a low temperature enough to evaporate the solvent, and have reached the present invention.

Thus, according to the present invention, there is provided a photosensitive resin composition containing at least a polyimide resin soluble in an organic solvent, a photopolymerizable unsaturated compound, a photopolymerization initiator, and an organic solvent. A photosensitive resin composition is provided wherein the compound is epoxy acrylate or a (meth) acrylic acid compound having three or more (meth) acryloyl groups in one molecule.

Further, according to the present invention, a film made of the photosensitive resin composition is formed on a substrate, and a desired pattern is exposed to light to cure the photopolymerizable unsaturated compound in the exposed portion. Forming a film, developing the film to remove unexposed portions, forming a desired pattern by heat treatment at a temperature at which the cured film does not decompose and the organic solvent can evaporate. Is provided.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The photosensitive resin composition of the present invention does not use a polyamic acid having a carboxyl group that reacts with a metal such as copper, and a polyimide resin soluble in an organic solvent.
It is characterized by containing a polymerizable unsaturated compound, a photopolymerization initiator and an organic solvent. Therefore, it is not necessary to perform a heat treatment at a high temperature for an imidization reaction unlike the conventional photosensitive resin composition.

In the related art, conventionally, when an insulating layer made of a polyimide resin is formed, a photosensitive resin composition contains a polyamic acid that is soluble in an organic solvent. The polyamic acid becomes insoluble in an organic solvent when subjected to dehydration ring closure (imidization) by heat treatment. However, in the present invention, a polyimide resin that is closed from the stage of the photosensitive resin composition, has a portion soluble in an organic solvent in a resin skeleton, and is soluble in an organic solvent is used.

The polyimide resin of the present invention is not particularly limited as long as it can be dissolved in an organic solvent, and any polyimide resin obtained from an aliphatic or aromatic tetracarboxylic acid and an aliphatic or aromatic diamine can be used. can do. Among them, a polyimide resin obtained from an aromatic tetracarboxylic acid and an aromatic diamine is preferable because of its high heat resistance. Specifically, the general formula (I)

[0017]

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Wherein X is an arylene group which may have a substituent, and a polyimide resin containing a benzophenonetetracarboxylic acid residue represented by the following formula: In the definition of the general formula (I), examples of the arylene group include phenylene, biphenylene, naphthylene, oxybiphenylene, oxobiphenylene, and phenylindanediyl.

Examples of the substituent of the arylene group include lower alkyl groups such as methyl and ethyl. More specifically, maleimide 528 (a polyimide resin of benzophenonetetracarboxylic acid and phenylindanediamine) manufactured by Ciba-Geigy Corporation, and TPI series (polyimide of benzophenonetetracarboxylic acid or a derivative thereof and phenylenediamine manufactured by Mitsui Toatsu Chemicals, Inc.) Resin or a derivative thereof).

The photopolymerizable unsaturated compound usable in the present invention comprises epoxy acrylate or a (meth) acrylic acid compound having three or more (meth) acryloyl groups as a photosensitive group in one molecule. In such a photopolymerizable unsaturated compound, a photosensitive group remains even after pattern formation, so that film loss due to elimination of the photosensitive group does not occur unlike the conventional photosensitive resin composition.

Specific examples of the photopolymerizable unsaturated compound include:
The terminal of epoxy resin such as bisphenol A-diepoxy- (meth) acrylic acid adduct, bisphenol A-dipropylene oxide- (meth) acrylic acid adduct, triglycerin di (meth) acrylate ether is substituted with (meth) acryl group. Epoxy (meth) acrylate. These photopolymerizable unsaturated compounds have good heat resistance after polymerization and good adhesion to a substrate.

Further, as the photopolymerizable unsaturated compound, a (meth) acrylic acid compound having three or more (meth) acryloyl groups in one molecule can be used. Specifically, ethylene glycol diglycidyl ether- (meth) acrylic acid adduct, propylene glycol diglycidyl ether- (meth) acrylic acid adduct, tripropylene glycol diglycidyl ether- (meth) acrylic acid adduct, 1, 6-hexanediol diglycidyl ether-
(Meth) acrylic acid adduct, glycerin diglycidyl ether- (meth) acrylic acid adduct, pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, isocyanuric acid ethylene oxide modified tri (meth) acrylate or penta Erythritol tetra (meth) acrylate and the like. These photopolymerizable unsaturated compounds have excellent developing properties such as photocurability and photoselectivity, and also have high heat resistance after polymerization.

The above photopolymerizable unsaturated compound may be used alone or
You may use it in combination of types or more. The photopolymerization initiator that can be used in the present invention is not particularly limited as long as the photopolymerization initiator is used for curing a resin or a paint. For example, 2,2′-dimethoxy-2-phenylacetophenone (alias: benzylmethyl ketal),
2'-bis (o-chlorophenyl) -4,4 ', 5
5'-tetraphenyl-1,2'-biimidazole, 4
-Phenoxydichloroacetophenone, thioxanthone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2-methyl-1- [4- (methylthio)
Phenyl] -2-morpholinopropanone, benzoin,
Benzophenone, 4-phenylbenzophenone, 2,4
-Dimethylthioxanthone and the like. These photopolymerization initiators may be used alone or in combination of two or more.

The organic solvent that can be used in the present invention is not particularly limited as long as it can dissolve the polyimide resin. For example, N-methyl-2-pyrrolidone, N, N
-Dimethylformamide, N, N-dimethylacetamide, dioxane, dimethylsulfoxide, tetramethylenesulfone, p-chlorophenol, p-bromophenol, hexamethylphosphoramide, tetrahydrofuran, triglyme, γ-butyrolactone, butyrolactam and the like. These organic solvents may be used alone or in combination of two or more.

The photopolymerizable unsaturated compound is preferably added in a proportion of 50 to 400 parts by weight based on 100 parts by weight of the polyimide resin. If the compounding ratio of the photopolymerizable unsaturated compound is less than 50 parts by weight, it is not preferable because the photosensitive resin composition hardly undergoes photocuring. If the amount is more than 400 parts by weight, it is not preferable because the heat resistance of the polyimide resin cannot be improved. In addition, the compounding ratio of the photopolymerizable unsaturated compound is more preferably 50 to 200 parts by weight.

The photopolymerization initiator is a photopolymerizable unsaturated compound 1
It is preferable to add 0.01 to 30 parts by weight to 00 parts by weight. The mixing ratio of the photopolymerization initiator is
If the amount is less than 0.01 part by weight, the polymerization of the photopolymerizable unsaturated compound becomes insufficient, which is not preferable. If the amount is more than 30 parts by weight, it is not preferable because the obtained film deteriorates and heat resistance decreases.

The organic solvent is used in the photosensitive resin composition.
Preferably, it is contained in an amount of up to 50% by weight. 10% by weight
If the amount is less, the viscosity of the resin increases, and kneading and coating become difficult, which is not preferable. If more than 50% by weight,
It is not preferable because the resin content (solid content) decreases and the film loss increases. Note that a sensitizer may be added to increase the exposure efficiency. Specific examples of the sensitizer include Michler's ketone, ketocoumarin, and pyrylium salt.
These sensitizers may be used alone or in combination of two or more. The sensitizer is preferably added in a proportion of 0.001 to 10 parts by weight based on 100 parts by weight of the photopolymerizable unsaturated compound.

Next, the pattern forming method of the present invention will be described. According to the pattern forming method of the present invention, first, a film made of the above-mentioned photosensitive resin composition (hereinafter, photosensitive resin composition film) is formed on a substrate. As the base material, silicon,
Substrates of alumina, ceramic, metal, etc., printed wiring boards, copper-clad laminates and the like can be mentioned. Since the photosensitive resin composition of the present invention does not have a carboxyl group having high reactivity with a metal such as copper, it can be used for any type of base material.

As the method for forming the photosensitive resin composition film, any known coating method can be used. In particular,
Coating methods such as a dip coater, a spray coater, a curtain coater, and a spin coater may be used. The photosensitive resin composition film is preferably subjected to temporary drying to such an extent that it does not flow.
Also, instead of applying the photosensitive resin composition directly on the substrate, apply it on a support film, temporarily dry it, and then apply pressure and transfer to the substrate using a roller, laminator, etc. A composition film can also be formed. However, the present invention is not limited to the method for forming the photosensitive resin composition film.

Next, a desired pattern is exposed on the photosensitive resin composition film to cure the photopolymerizable unsaturated compound in the exposed portion to form a cured film. As the exposure method,
There is a method of exposing through a mask on which a desired pattern is formed. The light source used for exposure is not particularly limited. For example, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, and the like are preferable because they emit highly active ultraviolet light. Alternatively,
A desired pattern may be directly formed without a mask using a light source, a laser beam, or the like in which light emitted from a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, or the like is focused on a minimum region.

Next, development is performed to remove unexposed portions.
As a developer used for development, an aqueous alkali solution or an organic solvent is generally used. As the alkali component contained in the aqueous alkali solution, hydroxides, carbonates, bicarbonates, silicates, phosphates, borates, acetates, amines and the like of alkali metals and quaternary ammoniums are used. Specific examples include sodium hydroxide, potassium hydroxide, ammonium hydroxide, tetramethylammonium hydroxide, potassium carbonate, potassium borate, potassium hydrogen carbonate, sodium silicate, potassium phosphate, sodium acetate, triethanolamine, choline and the like. . The alkaline component is water 1
The amount is suitably from 0.01 to 50 parts by weight, more preferably from 0.05 to 10 parts by weight, based on 00 parts by weight.

Examples of the organic solvent include alcohols such as ethyl alcohol, methyl alcohol and isopropyl alcohol, ketones such as methyl ethyl ketone and acetone, and ethers. Further, a second organic solvent used as a solvent for the polyamic acid may be added. Specifically, N-methyl-2-pyrrolidone, N, N-dimethylformamide, N, N-methylacetamide, dioxane, dimethyl sulfoxide, tetramethylene sulfone, p-chlorophenol, p-bromophenol,
Hexamethylphosphoramide, tetrahydrofuran, triglyme, γ-butyrolactone, butyrolactam and the like can also be used. When adding the second organic solvent, the second organic solvent is added in an amount of 0.1 to 5 parts by weight based on 100 parts by weight of the organic solvent.
It is preferable to add 0 parts by weight.

Further, a desired pattern is formed by heat treatment at a temperature at which the cured film does not decompose and the organic solvent can evaporate. The heat treatment temperature is preferably from 80 to 300C. The organic solvent contained in the photosensitive resin composition is evaporated by the heat treatment, and the cured product of the photopolymerizable unsaturated compound also remains in the cured film, so that a pattern having good film properties, particularly good heat resistance, is formed. Can be. Furthermore, since good film characteristics can be obtained even in a temperature range of 150 to 230 ° C., a desired pattern can be formed on a resin substrate such as a glass epoxy resin substrate having low heat resistance. Since the pattern obtained by the photosensitive resin composition of the present invention is excellent in heat resistance, for example, an interlayer insulating film of a high-density multilayer substrate in the electronics industry, a passivation film of a semiconductor element, a buffer coat film and an interlayer insulating film, Suitable for use as protective films for parts and circuits.

[0034]

【Example】

Example 1 100 g of a varnish containing a polyimide resin soluble in an organic solvent (resin content 15% by weight, solvent N-methyl-2-pyrrolidone: maleimide 528 manufactured by Ciba Geigy), bisphenol A- as a photopolymerizable unsaturated compound Diepoxy
Acrylic acid adduct (V540 manufactured by Osaka Organic Chemical Industry Co., Ltd.)
10 grams and 10 grams of pentaerythritol triacrylate were placed in a 300 ml flask equipped with a stirrer.

Next, 2,2'-bis (o-chlorophenyl) -4,4'-
2 g of 5,5′-tetraphenyl-1,2′-biimidazole was added, and the mixture was sufficiently stirred and mixed to obtain a uniform photosensitive resin composition. In the production process of the photosensitive resin composition, since a complicated reaction route such as the introduction of a conventional photosensitive group is not taken, it is used in the following steps without the need for an operation such as filtration or purification. I was able to.

Next, about 5 grams of this photosensitive resin composition was applied to a 3-inch diameter silicon wafer by a spin coater. This was placed in an oven and dried at 120 ° C. for 1 hour to obtain a dried film having a thickness of about 12 μm. Next, exposure was performed through a mask on which a desired pattern was formed, using all wavelengths of an extra-high pressure mercury lamp. The exposure amount at that time is 365 nm
The conversion was 250 mJ / cm ² .

The exposed film was developed with an aqueous solution containing 2.38% by weight of tetramethylammonium hydroxide to remove unexposed portions and rinsed with pure water to obtain a clear pattern. Was. The film thickness of the photosensitive resin composition after the development was about 10 μm. Finally, a heat treatment is performed in nitrogen at 230 ° C. for 30 minutes to give a final film thickness of 8
A μm membrane was obtained. This means that the resin component in the photosensitive resin composition hardly volatilized by the heat treatment and remained in the film, so that the film loss was small. Thermogravimetric analysis of the obtained film showed that the 5% thermal decomposition reduction temperature was 3%.
It was confirmed that it had a good heat resistance of 40 ° C.

Example 2 100 g of a varnish containing a polyimide resin soluble in an organic solvent (resin content: 17% by weight, solvent: N-methyl-2-pyrrolidone: TPI manufactured by Mitsui Toatsu Chemicals, Inc.) and photopolymerizable unsaturated As a compound, 15 g of pentaerythritol tetraacrylate was placed in the same flask as in Example 1.

Next, 2 g of 2.2-dimethoxy-2-phenylacetophenone (Irgacure 651 manufactured by Ciba Geigy) was added as a photopolymerization initiator, and the mixture was sufficiently stirred and mixed to obtain a uniform photosensitive resin composition. Obtained. In the production process of the photosensitive resin composition, since a complicated reaction route such as the introduction of a conventional photosensitive group is not taken, it is used in the following steps without the need for an operation such as filtration or purification. I was able to.

Next, about 5 grams of this photosensitive resin composition was applied to a 3-inch diameter silicon wafer by a spin coater. This was placed in an oven and dried at 120 ° C. for 1 hour to obtain a dried film having a thickness of about 13 μm. Next, exposure was performed through a mask on which a desired pattern was formed, using all wavelengths of an extra-high pressure mercury lamp. The exposure amount at that time is 365 nm
The conversion was 250 mJ / cm ² .

The exposed film was developed with an aqueous solution containing 3% by weight of potassium borate to remove unexposed portions and rinsed with pure water to obtain a clear pattern. The thickness of the photosensitive resin composition after development is about 10 μm.
m. Finally, heat treatment was performed in nitrogen at 230 ° C. for 30 minutes to obtain a film having a final film thickness of 8 μm. Thermogravimetric analysis of the obtained film showed that the first-stage weight loss started around 360 ° C., and subsequently the second-stage weight loss started around 430 ° C. The weight loss in the first stage is consistent with the thermogravimetric curve of the photopolymerizable unsaturated compound other than the polyimide resin in the photosensitive resin composition, and the weight loss in the second stage is almost the same as the thermogravimetric curve of the polyimide resin. I was doing it. From this, it was found that the photopolymerizable unsaturated compound was not decomposed by the heat treatment during the film forming step and remained in the film.

Example 3 100 g of a varnish containing a polyimide resin soluble in an organic solvent (resin content 18% by weight, solvent N-methyl-2-pyrrolidone: TPI manufactured by Mitsui Toatsu Chemicals, Inc.) and photopolymerizable unsaturated As a compound, 15 g of epoxy acrylate (Epolite 3000A manufactured by Kyoeisha Yushi Kagaku Kogyo KK) and 15 g of pentaerythritol tetraacrylate were placed in the same flask as in Example 1.

Next, 3.5 g of 2.2-dimethoxy-2-phenylacetophenone (Irgacure 651 manufactured by Ciba Geigy) as a photopolymerization initiator and 0.5 g of Michler's ketone as a sensitizer were added, and the mixture was sufficiently stirred. By mixing, a uniform photosensitive resin composition was obtained. In the production process of the photosensitive resin composition, since a complicated reaction route such as the introduction of a conventional photosensitive group is not taken, it is used in the following steps without the need for an operation such as filtration or purification. I was able to.

Next, about 5 g of the photosensitive resin composition was 85 mm square, 1.6 mm thick, and copper wiring (35 μm thick).
Was applied on a glass epoxy substrate (equivalent to FR-4) using a spin coater. This was dried in an oven at 110 ° C. for 1 hour to obtain a dried film having a thickness of about 15 μm. Next, exposure was performed through a mask on which a desired pattern was formed, using all wavelengths of an extra-high pressure mercury lamp. The exposure amount at that time was 250 mJ / cm ^{2 in} 365 nm conversion.

The unexposed portions were removed by developing the dried film after exposure with a developing solution in which 20% by weight of isopropyl alcohol was added to an aqueous solution containing 4% by weight of tetramethylammonium hydroxide, and the film was rinsed with pure water. However, a clear pattern could be obtained on the glass epoxy substrate. The thickness of the photosensitive resin composition after development is about 10
μm.

Finally, a heat treatment was performed in nitrogen at 200 ° C. for 30 minutes to obtain a film having a final film thickness of 8 μm. This means that the resin component in the photosensitive resin composition hardly volatilized by the heat treatment and remained in the film, so that the film loss was small. The obtained film was subjected to thermogravimetric analysis, and it was confirmed that the film had good heat resistance at a 5% thermal decomposition reduction temperature of 330 ° C.

[0047]

The photosensitive resin composition of the present invention is a photosensitive resin composition containing at least a polyimide resin soluble in an organic solvent, a photopolymerizable unsaturated compound, a photopolymerization initiator and an organic solvent, The photopolymerizable unsaturated compound is an epoxy acrylate or a (meth) acrylic acid-based compound having three or more (meth) acryloyl groups in one molecule.

Therefore, since it does not contain polyamic acid, which is a precursor of a polyimide resin, it has low reactivity to metals such as copper, and an insulating film can be formed directly on a substrate on which metals are laminated. Further, the pattern forming method of the present invention forms a film made of the photosensitive resin composition on a substrate, and cures a photopolymerizable unsaturated compound in an exposed portion by exposing a desired pattern to a cured film. After the formation, the unexposed portions are removed, and the heat treatment is performed at a temperature at which the cured film does not decompose and the organic solvent can evaporate to form a desired pattern.

Therefore, since the heat treatment temperature in the film forming step is low, a pattern having excellent heat resistance, electrical and mechanical properties can be formed on a substrate having low heat resistance. The film obtained by the pattern forming method of the present invention is, for example, an interlayer insulating film of a high-density multilayer substrate in the electronics industry, a passivation film of a semiconductor element, a buffer coat film, an interlayer insulating film, an electronic component, a protective film of a circuit, and the like. Suitable for use.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI G03F 7/027 515 G03F 7/027 515 7/037 501 7/037 501 7/09 501 7/09 501 7/40 501 7 / 40 501 H01L 21/027 H01L 21/312 B 21/312 21/30 502R

Claims (7)

[Claims] 1. A photosensitive resin composition comprising at least a polyimide resin soluble in an organic solvent, a photopolymerizable unsaturated compound, a photopolymerization initiator and an organic solvent, wherein the photopolymerizable unsaturated compound is epoxy acrylate or A photosensitive resin composition, which is a (meth) acrylic acid compound having three or more (meth) acryloyl groups in one molecule. 2. A polyimide resin having the general formula (I): The photosensitive resin composition according to claim 1, wherein X is an arylene group which may have a substituent. 3. The photopolymerizable unsaturated compound is a bisphenol A-diepoxy- (meth) acrylic acid adduct, bisphenol A-dipropylene oxide- (meth) acrylic acid adduct, triglycerin di (meth) acrylate ether, Ethylene glycol diglycidyl ether- (meth) acrylic acid adduct, propylene glycol diglycidyl ether- (meth) acrylic acid adduct, tripropylene glycol diglycidyl ether- (meth) acrylic acid adduct, 1,6-hexanediol di Glycidyl ether- (meth) acrylic acid adduct, glycerin diglycidyl ether- (meth) acrylic acid adduct, pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, isocyanuric acid ethylene oxide 3. The photosensitive resin composition according to claim 1, which is selected from a modified tri (meth) acrylate and pentaerythritol tetra (meth) acrylate. 4. An organic solvent comprising N-methyl-2-pyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, dioxane, dimethylsulfoxide, tetramethylene sulfone, p-chlorophenol, p-bromophenol. The photosensitive resin composition according to any one of claims 1 to 3, wherein the composition is selected from hexamethylphosphoramide, tetrahydrofuran, triglyme, γ-butyrolactone, and butyrolactam. 5. The photopolymerizable unsaturated compound is added in an amount of 50 to 400 parts by weight with respect to 100 parts by weight of the polyimide resin, and the photopolymerization initiator is mixed with 100 parts by weight of the photopolymerizable unsaturated compound. The photosensitive resin composition according to any one of claims 1 to 4, wherein the organic solvent is contained in the photosensitive resin composition in a proportion of 10 to 50 wt% in a blending ratio of 50 to 200 parts by weight. 6. A film comprising the photosensitive resin composition according to claim 1 is formed on a substrate, and a desired pattern is exposed to cure the photopolymerizable unsaturated compound in the exposed portion. After forming the cured film, the unexposed portion is removed by developing, and the cured film is not decomposed, and is heat-treated at a temperature at which the organic solvent can evaporate, thereby forming a desired pattern. Pattern formation method. 7. The pattern forming method according to claim 6, wherein the substrate is made of a glass epoxy resin.