KR102162595B1 - Photosensitive resin composition for insulation layer, and cured product thereof - Google Patents

Abstract

(ii) 적어도 1개의 에틸렌성 불포화 결합을 갖는 광중합성 모노머, (iii) 광중합 개시제, 및 (iv) 에폭시 화합물을 필수적인 성분으로서 함유하는 것을 특징으로 하는 절연막용 감광성 수지 조성물이다.(assignment)
A photosensitive resin composition for an insulating film suitable for a permanent insulating film that can achieve high sensitivity even if the amount of the photopolymerization initiator is not increased, and is excellent in resolution, reliability, and chemical resistance is provided.
(Solution)
(i) an alkali-soluble resin represented by the following general formula (1) and having a carboxyl group and a polymerizable unsaturated group in one molecule,

(ii) A photopolymerizable monomer having at least one ethylenically unsaturated bond, (iii) a photopolymerization initiator, and (iv) an epoxy compound as essential components.

Description

Photosensitive resin composition for insulating film, and cured product {PHOTOSENSITIVE RESIN COMPOSITION FOR INSULATION LAYER, AND CURED PRODUCT THEREOF}

The present invention relates to a photosensitive resin composition for an insulating film suitable for a solder resist for preparing a circuit board, a plating resist, an etching resist, an insulating film for multilayering a wiring board on which a semiconductor element is mounted, a gate insulating film for a semiconductor, a photosensitive adhesive, etc. It relates to a cured product formed using a photosensitive resin composition.

In recent years, with the high performance and high definition of electronic devices and display members, electronic components used therein are required to be miniaturized and high-density. In addition, in the workability of insulating materials used for them, miniaturization and an appropriate cross-sectional shape of the processed pattern have been required. As an effective means of fine processing of insulating materials, a method of patterning by exposure and development has been known, and a photosensitive resin composition has been used there, but there are many various types such as high sensitivity, adhesion to the substrate, reliability, heat resistance, and chemical resistance. Characteristics are being demanded. In addition, various studies have been conducted on the use of organic insulating materials in the gate insulating film for organic TFTs, but there is a need to reduce the operating voltage of the organic TFT by thinning the gate insulating film, and the dielectric breakdown voltage is generally about 1 MV/cm. For organic insulating materials, application of a thin film of about 0.2 µm is being studied.

The conventional insulating material made of a photosensitive resin composition uses a photocuring reaction by reaction of a photoreactive alkali-soluble resin and a photopolymerization initiator, and as an exposure wavelength for photocuring, i-line ( 365nm) is being used. However, this i-line is absorbed by the photosensitive resin itself or the colorant, resulting in a decrease in the degree of photocuring. In addition, if it is a thick film, the amount of absorption increases. Therefore, a difference in crosslinking density with respect to the film thickness direction occurs in the exposed portion, and even if it is sufficiently photocured on the surface of the coating film, it is difficult to photocure at the bottom of the coating film, resulting in a difference in crosslinking density between the exposed portion and the unexposed portion. It becomes remarkably difficult to make it difficult, and it is difficult to obtain a photosensitive insulating material capable of developing with high resolution due to deterioration of pattern dimensional stability, development margin, pattern adhesion, and edge shape and cross-sectional shape of the pattern.

On the other hand, in the case of forming a pattern with a thin film of 1 μm or less, photocuring is difficult to proceed due to the influence of oxygen inhibition, and even if the exposure time is increased, the film thickness of the exposed portion is reduced or peeled off due to an alkali developer. . Therefore, conventionally, in order to solve these problems, it has been solved by adding a large amount of photopolymerization initiators and sensitizers to increase sensitivity. However, with this solution, the photopolymerization initiator remaining in the film is released as a decomposition gas due to heat curing of the insulating film layer after light patterning and the heating process during mounting, resulting in contamination of a drying furnace or a clean room, and mounting reliability in physical property tests. It causes problems such as deterioration. Therefore, there is a demand for an insulating material that allows good light pattern formation and has less decomposition and volatilization components during heating after light patterning.

In general, the photosensitive resin composition for such a use includes a polyfunctional photocurable monomer having a polymerizable unsaturated bond, an alkali-soluble binder resin, a photopolymerization initiator, etc., and has been disclosed as an application as a material for color filters. A photosensitive resin composition can be applied. For example, Japanese Patent Application Laid-Open No. 61-213213 (Patent Document 1) or Japanese Patent Application Laid-Open No. 1-152449 (Patent Document 2) discloses (meth)acrylic acid or (meth)acrylic acid ester having a carboxyl group as a binder resin. And, a copolymer of maleic anhydride and another polymerizable monomer is disclosed. However, since the copolymer disclosed herein is a random copolymer, the distribution of the alkali dissolution rate occurs within the light irradiated portion and the non-light irradiated portion, and the margin at the time of development operation is narrow to obtain an acute angle pattern shape or fine pattern. It is difficult. Particularly, when a high-concentration pigment is included, exposure sensitivity is remarkably lowered, and a fine negative pattern cannot be obtained. In addition, Japanese Unexamined Patent Application Publication No. Hei 4-340965 (Patent Document 3) discloses that an alkali-soluble unsaturated compound having a polymerizable unsaturated double bond and a carboxyl group in one molecule is effective in forming a negative pattern such as a color filter. . Since the alkali-soluble molecule is insolubilized by light irradiation, it is predicted to have a high sensitivity compared to the combination of the binder resin and the polyfunctional polymerizable monomer described above, but the compound exemplified here is polymerized with the hydroxyl group of the phenol oligomer. Acrylic acid and acid anhydride, which are unsaturated bonds, are optionally added, and even in the case of this proposal, the distribution of the alkali dissolution rate of the alkali-soluble resin is widened because a wide distribution is possible in the molecular weight of each molecule and the amount of carboxyl groups. It is difficult to form a pattern.

On the other hand, Japanese Patent Application Laid-Open No. Hei 4-345673 (Patent Document 4), Japanese Patent Application Laid-Open No. 4-345608 (Patent Document 5), Japanese Patent Application Laid-Open No. Hei 4-355450 (Patent Document 6), and Japanese Patents Publication No. Hei 4-363311 (Patent Document 7) discloses a liquid resin using a reaction product of an epoxy (meth)acrylate having a bisphenol fluorene structure and an acid anhydride. However, since the resin exemplified by these is a reaction product of an epoxy (meth)acrylate and an acid monohydride, the molecular weight is small. Therefore, it is difficult to increase the difference in alkali solubility of the exposed portion and the unexposed portion, and thus a fine pattern cannot be formed.

In addition, Japanese Patent Application Laid-Open No. Hei 5-339356 (Patent Document 8), Japanese Patent Laid-Open No. 5-146132 (Patent Document 9), and WO94/00801 pamphlet (Patent Document 10) include dihydroxypropyl acrylate. An alkali developable unsaturated resin composition by copolymerization of a compound and an acid dianhydride, or an alkali developable unsaturated resin composition by copolymerization of an acid dianhydride and an acid dianhydride and a dihydroxypropyl acrylate compound is disclosed. In this case, the copolymerization of the acid dianhydride and the dihydroxypropyl acrylate compound proceeds to obtain an oligomer. However, with the number of polymerizable unsaturated bonds of this copolymer, the crosslinking density may not be sufficiently obtained, and for example, it may be difficult to form a fine wire pattern under a high concentration pigment. There is room for improvement of the copolymer structure, such as increasing the ratio.

Further, in Japanese Patent Laid-Open No. 9-325494 (Patent Document 11), the molecular weight of the carboxyl group-containing copolymer is increased to make the alkali-soluble resin composition polyfunctional. However, in this case as well as in the above patent document, since the ratio of the polymerizable unsaturated bond per molecule is not increased, the crosslinking density is not improved.

Japanese Patent Laid-Open Publication No. 61-213213 Japanese Patent Laid-Open Publication No. Hei 1-152449 Japanese Patent Laid-Open Publication No. Hei 4-340965 Japanese Patent Laid-Open No. Hei 4-345673 Japanese Patent Laid-Open No. Hei 4-345608 Japanese Patent Laid-Open No. Hei 4-355450 Japanese Patent Laid-Open No. Hei 4-363311 Japanese Patent Publication No. Hei 5-339356 Japanese Patent Laid-Open No. Hei 5-146132 WO94/00801 pamphlet Japanese Patent Publication No. Hei 9-325494

It is an object of the present invention to solve the above problems and to provide a photosensitive resin composition for an insulating film suitable for a permanent insulating film that can achieve high sensitivity even without increasing the amount of the photopolymerization initiator added, and is also excellent in resolution, reliability and chemical resistance. . In particular, it is to provide a photosensitive resin composition for insulating films capable of forming a permanent insulating film excellent in resolution and reliability while maintaining a sufficient residual film rate even after passing through a developing step in a thin film of 1 μm or less.

In order to solve the above problems, the present inventors intensively studied, as a result, an epoxy compound containing a polymerizable unsaturated bond group in a carboxyl group-containing copolymer obtained by reacting a diol compound containing a polymerizable unsaturated group with a tetracarboxylic acid or its acid dianhydride. It was discovered that a photosensitive resin composition using an alkali-soluble resin obtained by reacting and further reacting a dicarboxylic acid or an acid unihydride thereof is preferable for formation of an insulating film requiring light patterning. That is, by using this alkali-soluble resin, it is highly sensitive, and by improving the crosslinking density of the alkali-soluble resin, the difference in the solubility of the exposed portion and the unexposed portion in an alkali developer can be increased, and the film reduction during development is small, so the desired pattern shape It becomes possible to get Then, a good pattern can be formed over a wide range from a thick film such as 10 µm or more to a thin film of about 1 µm, and it has succeeded in forming a cured film suitable as an insulating material. In addition, it was found that even with a finer thin film of 0.1 µm to 1 µm, good pattern formation and cured film formation can be performed without any problems.

That is, the present invention is (i) an alkali-soluble resin represented by the following general formula (1) and having a carboxyl group and a polymerizable unsaturated group in one molecule,

(However, R ₁ , R ₂ , R ₃ , and R ₄ independently represent a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a halogen atom or a phenyl group, and R ₅ represents a hydrogen atom or a methyl group. In addition, X is- CO-, -SO ₂ -, -C(CF ₃ ) ₂ -, -Si(CH ₃ ) ₂ -, -CH ₂ -, -C(CH ₃ ) ₂ -, -O-, 9,9-fluore Represents a nylene group or a direct bond, and Y represents a tetravalent carboxylic acid residue, G represents a substituent having a polymerizable double bond and a carboxyl group, or a group having a polymerizable double bond and a hydroxyl group Z is the following general formula The substituent represented by (2) or a hydrogen atom is represented, and n represents the number of 1-20)

(However, L represents a divalent or trivalent carboxylic acid residue, p is 1 or 2)

(ii) a photopolymerizable monomer having at least one ethylenically unsaturated bond,

(iii) a photopolymerization initiator, and

(iv) epoxy compound

It is a photosensitive resin composition for insulating films characterized by containing as an essential component.

In addition, the present invention is for an insulating film, characterized in that 0.1 to 10 parts by mass of the (iii) component and 10 to 40 parts by mass of the (iv) component are contained per 100 parts by mass of the total of the (i) component and the (ii) component. It is a photosensitive resin composition.

Further, the present invention is a cured product obtained by curing the photosensitive resin composition for an insulating film of the above base material.

Hereinafter, the photosensitive resin composition for an insulating film of this invention is demonstrated in detail.

The photosensitive resin composition for insulating films of the present invention is an alkali developing type photosensitive resin composition containing an alkali-soluble resin represented by General Formula (1) as a main component. In order to have a photopolymerizable unsaturated group derived from a diol compound having (meth)acrylic acid, the alkali-soluble resin represented by the general formula (1) contains an acidic group derived from an acid dianhydride and an acid dianhydride in addition to having radical polymerization. Therefore, it has alkali solubility.

The alkali-soluble resin of the general formula (1) is obtained by reacting (meth)acrylic acid with an epoxy compound having two glycidyl ether groups derived from bisphenols, and the obtained diol compound having a polymerizable unsaturated group is tetracarboxylic acid or its acid. It is a carboxyl group-containing alternating copolymer obtained by reacting a dianhydride, further reacting the resulting reactant with an oxirane compound containing a polymerizable double bond, and further reacting a dicarboxylic acid or a tricarboxylic acid and the acid monoanhydride. . Since the alkali-soluble resin of the general formula (1) has both a polymerizable unsaturated double bond and a carboxyl group, it imparts excellent photocurability, good developability, and patterning properties to the alkali-developable photosensitive resin composition. In addition, in a thick film of 10 to 50 μm, the photocurability is improved to the bottom of the resin to give a good pattern shape, and in a thin film of less than 1 μm, the resistance to an alkali developer in the exposed area is improved, and the amount of film reduction decreases, resulting in a sufficient amount of remaining film. It is obtained, and also peeling becomes difficult to occur.

A method for producing an alkali-soluble resin represented by General Formula (1) will be described in detail. First, the alkali-soluble resin of formula (1) is an epoxy compound having two glycidyl ether groups derived from bisphenols, particularly preferably by reacting an epoxy compound represented by formula (3) with (meth)acrylic acid. It is derived from a diol compound containing a polymerizable unsaturated group to be obtained.

In the general formula (3), R ₁ , R ₂ , R ₃ , and R ₄ independently represent a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a halogen atom or a phenyl group, but preferably a hydrogen atom, a carbon number 1 It is an alkyl group of -5 or a phenyl group, More preferably, it is a hydrogen atom. In addition, X is -CO-, -SO ₂ -, -C(CF ₃ ) ₂ -, -Si(CH ₃ ) ₂ -, -CH ₂ -, -C(CH ₃ ) ₂ -, -O-, 9 , A 9-fluorenylene group or a direct bond is represented, but a 9,9-fluorenylene group is preferable. Here, the 9,9-fluorenylene group refers to a group represented by the following general formula (4).

In addition, when the bisphenol is glycidyl ether, an oligomer unit represented by the following general formula (5) is mixed, but the average value of m in this general formula (5) is 0 to 10, preferably 0 to 2 There is no problem in the performance of this resin composition if it is in the range of.

The reaction of such an epoxy compound with (meth)acrylic acid can be performed using a known method, for example, using 2 moles of (meth)acrylic acid per 1 mole of the epoxy compound. In order to make (meth)acrylic acid react with all the epoxy groups, (meth)acrylic acid may be used in a slightly excess than an equimolar amount of an epoxy group and a carboxyl group. The reactants obtained by this reaction are described in Patent Document 6, for example. The reaction product obtained in this reaction is a diol compound containing a polymerizable unsaturated group, and is an epoxy (meth)acrylate compound as represented by the following general formula (6).

Preferred bisphenols used in the production of the epoxy compound of the general formula (3) used as a raw material for the alkali-soluble resin of the general formula (1) include the following. Bis(4-hydroxyphenyl)ketone, bis(4-hydroxy-3,5-dimethylphenyl)ketone, bis(4-hydroxy-3,5-dichlorophenyl)ketone, bis(4-hydroxyphenyl) Sulfone, bis(4-hydroxy-3,5-dimethylphenyl)sulfone, bis(4-hydroxy-3,5-dichlorophenyl)sulfone, bis(4-hydroxyphenyl)hexafluoropropane, bis(4 -Hydroxy-3,5-dimethylphenyl)hexafluoropropane, bis(4-hydroxy-3,5-dichlorophenyl)hexafluoropropane, bis(4-hydroxyphenyl)dimethylsilane, bis(4- Hydroxy-3,5-dimethylphenyl)dimethylsilane, bis(4-hydroxy-3,5-dichlorophenyl)dimethylsilane, bis(4-hydroxyphenyl)methane, bis(4-hydroxy-3,5) -Dichlorophenyl)methane, bis(4-hydroxy-3,5-dibromophenyl)methane, 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(4-hydroxy-3 ,5-dimethylphenyl)propane, 2,2-bis(4-hydroxy-3,5-dichlorophenyl)propane, 2,2-bis(4-hydroxy-3-methylphenyl)propane, 2,2-bis (4-hydroxy-3-chlorophenyl) propane, bis(4-hydroxyphenyl) ether, bis(4-hydroxy-3,5-dimethylphenyl) ether, bis(4-hydroxy-3,5- Dichlorophenyl) ether and the like. In addition, X is 9,9-fluorenyl group, 9,9-bis (4-hydroxyphenyl) fluorene, 9,9-bis (4-hydroxy-3-methylphenyl) fluorene, 9,9-bis (4-hydroxy-3-chlorophenyl)fluorene, 9,9-bis(4-hydroxy-3-bromophenyl)fluorene, 9,9-bis(4-hydroxy-3-fluorophenyl) ) Fluorene, 9,9-bis(4-hydroxy-3,5-dimethylphenyl)fluorene, 9,9-bis(4-hydroxy-3,5-dichlorophenyl)fluorene, 9,9- Bis(4-hydroxy-3,5-dibromophenyl)fluorene and the like are also preferably mentioned. Moreover, 4,4'-biphenol, 3,3'-biphenol, etc. are also mentioned preferably.

The alkali-soluble resin of the general formula (1) can be obtained from an epoxy compound derived from bisphenols as described above, but in addition to these epoxy compounds, a phenol novolak type epoxy compound, a cresol novolak type epoxy compound, etc. are also two glycidyl ethers. It can be used as long as it significantly contains a compound having a group.

Subsequently, tetracarboxylic acid or its acid dianhydride is reacted with a diol compound containing a polymerizable unsaturated group, followed by reacting an oxirane compound containing a polymerizable unsaturated group, and dicarboxylic acid or tricarboxylic acid and its A method of producing the alkali-soluble resin of the present invention represented by the general formula (1) by further reacting the acid monoanhydride will be described. An example of the method for producing the alkali-soluble resin of the present invention is shown in the following reaction formula (I). In addition, the alkali-soluble resin represented by general formula (9) is an example of the alkali-soluble resin represented by general formula (1), and is not limited to this structure.

(However, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , X, and Y are the same as those of the general formula (1). In addition, R ₆ is a divalent alkylene group, and R ₇ is a hydrogen atom or Represents a methyl group, and Z represents a substituent represented by the above general formula (2) or a hydrogen atom. In addition, n is a number from 1 to 20, p is the same as in the case of general formula (2), and q is 0 or Represents the number of 1)

Regarding the reaction formula (I), first, the epoxy (meth)acrylate compound (diol compound containing a polymerizable unsaturated group) of the general formula (6) obtained from the reaction of the above-described epoxy compound and (meth)acrylic acid and an acid component By reacting, a compound represented by general formula (7) (reactant having a carboxyl group) is obtained. At this time, the reaction conditions such as the solvent and catalyst to be used are not particularly limited, but, for example, a solvent having no hydroxyl group and having a boiling point higher than the reaction temperature is preferably used as the reaction solvent. For example, cellosolve solvents such as ethyl cellosolve acetate and butyl cellosolve acetate, and high-boiling ether-based or ester-based solvents such as diglyme, ethyl carbitol acetate, butyl carbitol acetate, propylene glycol monomethyl ether acetate, etc. A solvent or a ketone solvent such as cyclohexanone or diisobutyl ketone is preferable. In addition, as the catalyst to be used, for example, ammonium salts such as tetraethylammonium bromide and triethylbenzyl ammonium chloride, triphenylphosphine, and phosphines such as tris(2,6-dimethoxyphenyl)phosphine are used. I can. These are described in detail in Patent Document 11. Further, as the acid component, it is preferable to use an acid dianhydride (B) capable of reacting with a hydroxyl group in the molecule of the epoxy (meth)acrylate compound. As the acid dianhydride (B), an acid dianhydride of a saturated linear hydrocarbon tetracarboxylic acid, an acid dianhydride of a saturated cyclic hydrocarbon tetracarboxylic acid, and an acid dianhydride of an aromatic tetracarboxylic acid can be used.

Here, examples of the acid dianhydride of the saturated chain hydrocarbon tetracarboxylic acid include butanetetracarboxylic acid, pentanetetracarboxylic acid, and acid dianhydride of hexanetetracarboxylic acid. Further, a cycloalkyl group, An acid dianhydride of a saturated chain hydrocarbon tetracarboxylic acid substituted with a substituent such as an aromatic group may be used, or an acid dianhydride of an unsaturated chain hydrocarbon tetracarboxylic acid may be used.

In addition, as an acid dianhydride of a saturated cyclic hydrocarbon tetracarboxylic acid, an acid of cyclobutanetetracarboxylic acid, cyclopentanetetracarboxylic acid, cyclohexanetetracarboxylic acid, cycloheptanetetracarboxylic acid, and nobonanetetracarboxylic acid Dianhydrides and the like, and an acid dianhydride of a saturated cyclic tetracarboxylic acid substituted with a substituent such as an alkyl group, a cycloalkyl group, or an aromatic group may be used. Further, an acid dianhydride of an unsaturated cyclic hydrocarbon tetracarboxylic acid may be used.

In addition, as the acid dianhydride of aromatic tetracarboxylic acid, pyromellitic acid, benzophenone tetracarboxylic acid, biphenyltetracarboxylic acid, biphenyl ether tetracarboxylic acid, acid dianhydride of diphenyl sulfone tetracarboxylic acid, etc. Can be mentioned.

The acid dianhydride in the present invention is preferably an acid dianhydride of biphenyltetracarboxylic acid, benzophenonetetracarboxylic acid, or biphenylethertetracarboxylic acid, and more preferably biphenyltetracarboxylic acid, It is an acid dianhydride of biphenyl ether tetracarboxylic acid. These acid dianhydrides may be used in combination of two or more.

The method of preparing the compound represented by General Formula (7) by reacting an epoxy (meth)acrylate compound with an acid dianhydride is not particularly limited, and, for example, the reaction as described in Patent Document 11 The temperature is 90 to 140°C, and a known method of reacting an epoxy (meth)acrylate compound with a tetracarboxylic dianhydride can be employed. The molar ratio [(B)/(A)] of the diol compound (A) having a polymerizable unsaturated group represented by the general formula (6) to the acid dianhydride (B) is a hydroxyl group at the end of the compound represented by the general formula (7). To be, 30 mol% or more and less than 100 mol% are reacted quantitatively. When the molar ratio is less than 30 mol%, the content of the unreacted epoxy (meth)acrylate compound is increased, so that the alkali-soluble resin composition may have a decrease in stability over time. On the other hand, when the molar ratio is 100 mol% or more, the terminal of the compound represented by the general formula (7) becomes an acid anhydride, and the content of the unreacted acid dianhydride increases, so there is a concern about side reactions when reacting the oxirane compound later. do. A more preferable molar ratio [(B)/(A)] is 50 mol% or more and 70 mol% or less. In addition, as the reaction temperature, it is preferable to perform reaction while uniformly dissolving the charged raw material at 90 to 130°C, and then to react and aging at 40 to 80°C.

Subsequently, an oxirane compound (C) is reacted with the compound represented by the general formula (7) to obtain a compound represented by the general formula (8). The oxirane compound (C) is a compound containing one or more polymerizable double bonds and one oxirane ring, glycidyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate Cidyl ether, 3,4-epoxycyclohexyl methacrylate, etc. are mentioned.

The method for producing the compound represented by the general formula (8) is not particularly limited, and general reaction conditions for the addition reaction of the carboxylic acid and the epoxy compound can be used. In addition, by reacting a bisphenol fluorene-type epoxy resin and acrylic acid as described in Patent Document 11 above at 100°C using tetraethylammonium bromide or the like as a catalyst, the reaction of an epoxy compound and (meth)acrylic acid A method of preparing the epoxy (meth)acrylate compound may also be referred to. The reaction temperature when synthesizing the compound represented by the general formula (8) is preferably in the range of 40 to 120°C, and more preferably 40 to 90°C.

In order to obtain the compound represented by the general formula (8) by reacting the oxirane compound (C) with the compound represented by the general formula (7), the acid dianhydride used when preparing the compound represented by the general formula (7) It is necessary to react 200 mol% of (C) to (B). However, the required amount of the polymerizable unsaturated bond to be added to the compound represented by the general formula (7) is determined in response to the conditions of using the photosensitive resin composition using an alkali-soluble resin, and each of the compounds of the general formula (8) The structure of general formula (10) may be included in a part of the molecule.

In addition, taking into account the problem of the reactivity of the carboxyl group of the compound represented by the general formula (7) and the oxirane group of the oxirane compound (C), the oxirane compound when synthesizing the compound represented by the general formula (8) ( It is preferable that C) has a molar ratio [(C)/(B)] of 160 to 220 mol% with respect to the acid dianhydride (B). When the molar ratio is less than 160 mol%, the structure of the general formula (10) increases, and there is a concern about a decrease in molecular weight due to the regeneration reaction of the acid anhydride due to the unreacted carboxylic acid present in the structure. On the other hand, when the molar ratio exceeds 220 mol%, there is a concern about changes over time of the alkali-soluble resin represented by the general formula (1) due to side reactions derived from unreacted oxirane compounds. A more preferable range of the molar ratio [(C)/(B)] is 190 to 210 mol%.

Subsequently, an alkali-soluble resin represented by the general formula (9) is obtained by reacting the hydroxyl group of the compound represented by the above general formula (8) with an acid monoanhydride (D). Here, as the acid monohydride (D), an acid monohydride of a saturated chain hydrocarbon dicarboxylic acid or a tricarboxylic acid, an acid monohydride of a saturated cyclic hydrocarbon dicarboxylic acid or a tricarboxylic acid, and an unsaturated hydrocarbon dicarboxylic acid Alternatively, an acid monoanhydride of a tricarboxylic acid, an aromatic hydrocarbon dicarboxylic acid, or an acid monoanhydride of a tricarboxylic acid may be used. In addition, each hydrocarbon residue (structure excluding a carboxyl group) of these acid unihydrides may be further substituted with a substituent such as an alkyl group, a cycloalkyl group, or an aromatic group. Specific examples of the acid monoanhydride include saturated chain hydrocarbon dicarboxylic acid or tricarboxylic acid monohydride, such as succinic acid, acetylsuccinic acid, adipic acid, azelaic acid, citramalic acid, malonic acid, glutaric acid , Citric acid, tartaric acid, oxoglutaric acid, pimelic acid, sebacic acid, suberic acid, and anhydrides such as diglycolic acid. In addition, as an acid monohydride of a saturated cyclic hydrocarbon dicarboxylic acid or tricarboxylic acid, for example, hexahydrophthalic acid, cyclobutanedicarboxylic acid, cyclopentanedicarboxylic acid, nobornanedicarboxylic acid, hexahydrotri Acid anhydrides, such as melitic acid, are mentioned. Further, examples of the acid anhydride of an unsaturated dicarboxylic acid or tricarboxylic acid include acid anhydrides such as maleic acid, itaconic acid, tetrahydrophthalic acid, methylendomethylenetetrahydrophthalic acid, and chlorendic acid. Moreover, acid anhydrides, such as phthalic acid and trimellitic acid, are mentioned as an acid monohydride of an aromatic hydrocarbon dicarboxylic acid or tricarboxylic acid. Among these, the acid anhydride (D) is preferably an anhydride of succinic acid, itaconic acid, tetrahydrophthalic acid, hexahydrotrimellitic acid, phthalic acid, and trimellitic acid, and more preferably succinic acid, itaconic acid, and tetrahydrophthalic acid. It is anhydrous. In addition, these acid monoanhydrides (D) may be used alone or in combination of two or more.

The reaction temperature when synthesizing the compound represented by the general formula (9) by reacting the hydroxyl group of the compound represented by the general formula (8) with an acid monoanhydride (D) is preferably in the range of 20 to 120°C, more preferably It is 40~90℃. The molar ratio of the acid dianhydride (D) when synthesizing the compound represented by the general formula (9) is the number of moles of the diol compound (A), the acid dianhydride (B) and the oxirane compound (C) having the polymerizable unsaturated group. For the formula (2×((A)-(B))+(C)) converted from, that is, the molar ratio [(D)/[2 [(A)-(B)]+(C)]] is 20 It is good that it is -110 mol%. The molar ratio of the acid monoanhydride can be arbitrarily changed within the above range for the purpose of adjusting the acid value of the alkali-soluble resin represented by the general formula (1), but if it is less than 20 mol%, the acid value is too small and the alkali solubility becomes insufficient. On the other hand, when it exceeds 110 mol%, the residual amount of unreacted acid unihydride (D) increases, and when a cured product is obtained by using it as a photosensitive resin composition, a cured product with desired physical properties cannot be obtained. More preferable range of [(D)/[2[(A)-(B)]+(C)]] is 50 to 100 mol when the molar ratio [(C)/(B)] is 190 to 210 mol% %to be. In addition, when the value of the molar ratio [(C)/(B)] is small, the more preferable range of [(D)/[2[(A)-(B)]+(C)]] tends to be small. .

When trying to obtain a compound represented by general formula (9) according to Scheme I, 200 mol% of oxirane compound (C) with respect to acid dianhydride (B) in order to make all molecules into the structure of general formula (9) It is necessary to react, and then add the acid monoanhydride (D) so that the value of (D)/[2[(A)-(B)]+(C)] becomes 100 mol%, and react quantitatively. As also described in the description of the compound represented by the general formula (8), the required amount of the polymerizable unsaturated bond to be added to the compound represented by the general formula (7) is the condition of using a photosensitive resin composition using an alkali-soluble resin. It is determined by, and the preferred acid value is also determined by the composition design of the photosensitive resin composition using alkali-soluble. Therefore, it is not necessary to make all molecules the structure of general formula (9), and a compound containing the structure of general formula (11) may be included.

An example of a method for preparing the general formula (1) will be described in detail in the case of using 9,9-bis(4-hydroxyphenyl)fluorene as a starting material.

First, 9,9-bis (4-hydroxyphenyl) fluorene and epichlorohydrin were reacted to synthesize a bisphenol fluorene type epoxy compound represented by the following general formula (12), and this bisphenol fluorene type epoxy compound And CH ₂ =CHR ₅ -COOH (R ₅ is the same as above) by reacting (meth)acrylic acid represented by the following general formula (13) to synthesize a bisphenol fluorene type epoxy (meth) acrylate resin represented by . Subsequently, the bisphenol fluorene type epoxy (meth)acrylate resin is heated in a solvent such as propylene glycol monomethyl ether acetate, and the acid dianhydride (B), oxirane compound (C), and acid monoanhydride (D) are sequentially To obtain an alkali-soluble resin of the general formula (1).

The photosensitive resin composition for an insulating film of the present invention contains 30 wt% or more of an alkali-soluble resin represented by the general formula (1) of (i) in the solid content excluding the solvent (the solid content includes a monomer that becomes a solid content after curing), preferably It is good to contain 50wt% or more.

In order to utilize the characteristics of the photosensitive resin composition for an insulating film, the following components (i), (ii), (iii) and (iv) are contained as essential components. That is, (i) an alkali-soluble resin having a carboxyl group and a polymerizable unsaturated group in one molecule represented by the general formula (1), (ii) a photopolymerizable monomer having at least one ethylenically unsaturated bond, (iii) a photopolymerization initiator, and (iv) An epoxy compound is included as an essential component.

Among them, examples of the photopolymerizable monomer having at least one ethylenically unsaturated bond as component (ii) include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 2-ethyl Monomers having hydroxyl groups such as hexyl (meth) acrylate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) Acrylate, tetramethylene glycol di(meth)acrylate, trimethyrolpropane tri(meth)acrylate, trimethyrolethane tri(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth) (Meth)acrylic acid esters such as acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and glycerol (meth) acrylate. . When it is necessary to form a crosslinked structure between molecules of an alkali-soluble resin, it is preferable to use a photopolymerizable monomer having two or more ethylenically unsaturated bonds, and a photopolymerizable monomer having three or more ethylenically unsaturated bonds. It is more preferable to do it. These compounds can be used alone or in combination of two or more.

About the blending ratio [(i)/(ii)] of these (ii) component and alkali-soluble resin [(i) component] represented by general formula (1), it is preferable that it is 20/80-90/10, Preferably It is better to be 40/60~80/20. If the blending ratio of the alkali-soluble resin is small, the cured product after photocuring becomes brittle, and the acid value of the coating film is low in the unexposed portion, so that the solubility in the alkali developer is lowered, and the pattern edge is shaken, causing a problem that it does not become sharp. . Conversely, when the mixing ratio of the alkali-soluble resin is greater than the above range, the ratio of the photoreactive functional group occupied in the resin is small, so that the formation of the crosslinked structure by the photocuring reaction is not sufficient, and the acid value in the resin component is too high. Since the solubility in the alkali developer in the exposed portion is increased, there is a fear that the formed pattern becomes thinner than the target line width, or a problem that the pattern is easily missing occurs.

In addition, as the photoinitiator of component (iii), for example, acetophenone, 2,2-diethoxyacetophenone, p-dimethylacetophenone, p-dimethylaminopropiophenone, dichloroacetophenone, trichloroacetophenone, p- Acetophenones such as tert-butylacetophenone, benzophenones, 2-chlorobenzophenones, benzophenones such as p,p'-bisdimethylaminobenzophenone, benzyl, benzoin, benzoin methyl ether, benzoin isopropyl Benzoin ethers such as ether and benzoin isobutyl ether, 2-(o-chlorophenyl)-4,5-phenylbiimidazole, 2-(o-chlorophenyl)-4,5-di(m-me) Toxyphenyl)biimidazole, 2-(o-fluorophenyl)-4,5-diphenylbiimidazole, 2-(o-methoxyphenyl)-4,5-diphenylbiimidazole, 2,4 Biimidazole-based compounds such as ,5-triarylbiimidazole, 2-trichloromethyl-5-styryl-1,3,4-oxadiazole, 2-trichloromethyl-5-(p-sia Halomethylthiazole compounds such as nostyryl)-1,3,4-oxadiazole, 2-trichloromethyl-5-(p-methoxystyryl)-1,3,4-oxadiazole, 2 ,4,6-tris(trichloromethyl)-1,3,5-triazine, 2-methyl-4,6-bis(trichloromethyl)-1,3,5-triazine, 2-phenyl-4 ,6-bis(trichloromethyl)-1,3,5-triazine, 2-(4-chlorophenyl)-4,6-bis(trichloromethyl)-1,3,5-triazine, 2- (4-methoxyphenyl)-4,6-bis(trichloromethyl)-1,3,5-triazine, 2-(4-methoxynaphthyl)-4,6-bis(trichloromethyl)- 1,3,5-triazine, 2-(4-methoxystyryl)-4,6-bis(trichloromethyl)-1,3,5-triazine, 2-(3,4,5-tri Methoxystyryl)-4,6-bis(trichloromethyl)-1,3,5-triazine, 2-(4-methylthiostyryl)-4,6-bis(trichloromethyl)-1, Halomethyl-s-triazine compounds such as 3,5-triazine, 1,2-octanedione, 1-[4-(phenylthio)phenyl]-,2-(o-benzoyloxime), 1-( 4-phenylsulfanylphenyl)butane-1,2-dione-2-oxime-o-benzoate, 1-(4-methylsulfanylphenyl)butane-1,2-dione-2-oxime-o-acetate, 1-(4-methylsulfanylphenyl)butan-1-oneoxime-o-acetate O-acyloxime compounds such as, benzyl dimethyl ketal, thioxanthone, 2-chloro thioxanthone, 2,4-diethyl thioxanthone, 2-methyl thioxanthone, 2-isopropyl thioxanthone, etc. Sulfur compounds of, 2-ethylanthraquinone, octamethylanthraquinone, 1,2-benzanthraquinone, 2,3-diphenylanthraquinone, and other anthraquinones, azobisisobutylnitrile, benzoyl peroxide, cumene peroxide And thiol compounds such as organic peroxides such as 2-mercaptobenzoimidazole, 2-mercaptobenzooxazole, and 2-mercaptobenzothiazole; tertiary amines such as triethanolamine and triethylamine. . These photoinitiators can use 1 type or 2 or more types.

The amount of the photopolymerization initiator added is preferably 0.1 to 10 parts by mass, preferably 2 to 5 parts by mass based on 100 parts by mass of the total amount of the alkali-soluble resin and the photopolymerizable monomer. If it is less than 0.1 parts by mass, the sensitivity cannot be sufficiently obtained, and if it exceeds 10 parts by mass, the tapered shape (the shape in the film thickness direction of the cross section of the developing pattern) does not become sharp, and halation is likely to occur, leaving the end part. When exposed to high temperatures in the process, there is a possibility of generation of decomposition gas.

In addition, as an epoxy compound of (iv) component, for example, a phenol novolak type epoxy resin, a cresol novolak type epoxy resin, a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a bisphenol S type epoxy resin, a biphenyl type epoxy Resins, epoxy resins such as alicyclic epoxy resins, phenyl glycidyl ether, p-butylphenol glycidyl ether, triglycidyl isocyanurate, diglycidyl isocyanurate, allyl glycidyl ether, gly And compounds having at least one epoxy group such as cidyl methacrylate. When there is a need to increase the crosslinking density of the alkali-soluble resin, a compound having at least two or more epoxy groups is preferred.

The amount of the epoxy compound used as the component (iv) is preferably blended in the range of 10 to 40 parts by mass based on 100 parts by mass of the total of the component (i) and the component (ii). If it is less than 10 parts by mass, there is a concern that the amount of carboxyl groups remaining when the cured film is formed after patterning increases, and thus the moisture resistance reliability of the insulating film cannot be secured. When the amount is more than 40 parts by mass, there is a possibility that the amount of the photosensitive group in the resin component in the photosensitive resin composition decreases, and sufficient sensitivity for patterning may not be obtained.

For insulating films containing as essential components an alkali-soluble resin represented by the general formula (1) of the component (i), the photopolymerizable monomer of the component (ii), the photopolymerization initiator of the component (iii), and the epoxy compound of the component (iv) The photosensitive resin composition may be dissolved in a solvent as necessary, or may be used by mixing various additives. That is, when using the photosensitive resin composition of the present invention for use as an insulating material or the like, it is preferable to use a solvent other than the above essential components. As a solvent, for example, alcohols such as methanol, ethanol, n-propanol, isopropanol, ethylene glycol, and propylene glycol, terpenes such as α- or β-terpineol, acetone, methyl ethyl ketone, cyclohexanone, N- Ketones such as methyl-2-pyrrolidone, aromatic hydrocarbons such as toluene, xylene, and tetramethylbenzene, cellosolve, methyl cellosolve, ethyl cellosolve, carbitol, methylcarbitol, ethylcarbitol, butylcar Glycol ethers such as bitol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, ethyl acetate, Acetic acid esters such as butyl acetate, cellosolve acetate, ethyl cellosolve acetate, butyl cellosolve acetate, carbitol acetate, ethyl carbitol acetate, butyl carbitol acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, etc. These etc. are mentioned, and these can be made into a uniform solution-form composition by using them individually or by using 2 or more types and dissolving and mixing.

As another component of the photosensitive resin composition for an insulating film of the present invention, a known rubber component may be added in order to improve impact resistance and adhesion of the plated metal during processing. Among the rubber components, in order to ensure developability, a crosslinked elastomer having a carboxyl group is preferable. Specifically, a crosslinked acrylic rubber having a carboxyl group, a crosslinked NBR having a carboxyl group, a crosslinked MBS having a carboxyl group, and the like are mentioned. When using a rubber component, those having an average particle diameter of 0.1 µm or less in the primary particle diameter are preferably used in the range of 3 to 10 parts by mass per 100 parts by mass of the resin component.

In addition, additives such as a curing accelerator, a thermal polymerization inhibitor, a plasticizer, a filler, a leveling agent, and an antifoaming agent may be added to the photosensitive resin composition for an insulating film of the present invention, if necessary. Among these, examples of the thermal polymerization inhibitor include hydroquinone, hydroquinone monomethyl ether, pyrogallol, tert-butylcatechol, phenothiazine, and the like. Examples of the plasticizer include dibutyl phthalate, dioctyl phthalate, and tricresyl phosphate. Glass fiber, silica, mica, alumina, etc. are mentioned as a filler. Further, examples of the antifoaming agent and leveling agent include silicon-based, fluorine-based, and acrylic compounds.

The photosensitive resin composition for an insulating film of the present invention is an alkali-soluble resin represented by the general formula (1) of (i), and the photopolymerizable monomer of (ii) in a solid content excluding a solvent (solid content includes a monomer that becomes a solid content after curing). , (iii) a photoinitiator, and (iv) an epoxy compound are preferably contained in a total of 70 wt% or more, preferably 80 wt%, and more preferably 90 wt% or more. The amount of the solvent varies depending on the target viscosity, but is preferably in the range of 10 to 80 wt% based on the total amount.

In addition, the coating film (cured product) of the present invention is obtained by, for example, applying a solution of the photosensitive resin composition to a substrate, drying, irradiating light (including ultraviolet rays, radiation, etc.), and curing it. A photomask or the like is used to form a light-touched portion and a non-contact portion, cured only the light-touched portion, and dissolve the other portion with an alkaline solution to obtain a coating film of a desired pattern.

Next, a film forming method of an insulating film using the photosensitive resin composition will be described. First, a photosensitive resin composition is applied on the surface of a substrate, followed by prebaking to evaporate a solvent to form a coating film. Subsequently, the coating film is exposed to light through a photomask and then developed using an alkaline developer, and the unexposed portion of the coating film is dissolved and removed, and then post-baked to obtain an insulating film formed so as to partition a portion forming a pixel.

Specifically exemplifying each step of the film forming method, when applying the photosensitive resin composition to a substrate, any method such as a known solution immersion method, a spray method, a roller coater, a land coater, a slit coater or a spinner device is used. Either can be hired. By these methods, a film is formed by applying to a desired thickness and then removing the solvent (pre-baking). Pre-baking is performed by heating with an oven, a hot plate, or the like, vacuum drying, or a combination thereof. The heating temperature and heating time in prebaking are appropriately selected depending on the solvent to be used, and are performed for 1 to 10 minutes at a temperature of 80 to 120°C, for example.

As the radiation used for exposure, for example, visible light, ultraviolet light, far ultraviolet light, electron beam, X-ray, etc. can be used, but radiation having a wavelength in the range of 250 to 450 nm is preferable. As a developer suitable for this alkaline development, for example, an aqueous solution such as sodium carbonate, potassium carbonate, potassium hydroxide, diethanolamine, tetramethylammonium hydroxide, or the like can be used. These developing solutions are selected according to the characteristics of the resin layer, but it is also effective to add a surfactant as necessary. Further, it is preferable to develop at a temperature of 20 to 35°C, and a fine image can be precisely formed using a commercially available developer or ultrasonic cleaner. In addition, after alkali development, it is usually washed with water. As the developing treatment method, a shower developing method, a spray developing method, a dip (immersion) developing method, a puddle (liquid filling) developing method, or the like can be applied.

After developing in this way, heat treatment (post-baking) is performed at a temperature of 180 to 250°C and conditions for 20 to 100 minutes. This post-baking is performed for the purpose of improving the adhesion between the patterned coating film and the substrate. This is done by heating with an oven, a hot plate, or the like, like pre-baking. The patterned coating film of the present invention is formed through each process by the photolithography method described above. Then, polymerization or curing (which may be referred to as curing by combining both) is completed by heat to obtain an insulating film such as a permanent insulating film. The curing temperature at this time is preferably in the range of 160 to 250°C.

(Effects of the Invention)

Since the photosensitive resin composition for an insulating film of the present invention contains an alkali-soluble resin represented by the general formula (1), it is 1 compared to the conventional epoxy acrylate anhydride adduct [for example, a structure similar to the general formula (7)]. Since the number of ethylenically unsaturated bond groups in the molecule is large, the photocurability is improved, and the crosslinking density after curing can be increased without increasing the amount of the photopolymerization initiator. That is, when the thick film is irradiated with ultraviolet rays or electron beams, since the cured portion is cured to the bottom portion, the difference in solubility in the alkali developer between the exposed portion and the unexposed portion increases, thereby improving pattern dimensional stability, development margin, pattern adhesion, etc. The edge shape and cross-sectional shape of the pattern can also be formed cleanly. On the other hand, in the case of a thin film, since the resistance to the alkali developer of the exposed portion is improved by increasing the sensitivity, it is possible to significantly improve the amount of the remaining film and to suppress peeling during development. Therefore, the photosensitive composition for an insulating film of the present invention is a solder resist for preparing a circuit board, a plating resist, an etching resist, an insulating film for multilayering a wiring board on which a semiconductor element is mounted, a gate insulating film of a semiconductor, and a photosensitive adhesive (especially, photoless It is very useful for adhesives that require heat bonding performance even after pattern formation by graphing).

Hereinafter, the present invention will be described in more detail based on a synthesis example of an alkali-soluble resin represented by General Formula (1). In addition, the present invention does not limit its scope by these synthesis examples. In addition, evaluation of resin in these synthesis examples was performed as follows unless otherwise specified.

[Example]

[Solid content concentration]

1 g of the resin solution and photosensitive resin composition obtained in Synthesis Example (and Comparative Synthesis Example) were impregnated in a glass filter [mass: W0 (g)] and weighed [W1 (g)], and the mass after heating at 160°C for 2 hours It was calculated|required from [W2(g)] by the following formula.

Solid content concentration (mass%)=100×(W2-W0)/(W1-W0)

[Acid value]

The resin solution was dissolved in dioxane and titrated with 1/10N-KOH aqueous solution using a potentiometric titrator [COM-1600 manufactured by Hiranuma Seisakusho Co., Ltd.], and the amount of KOH required per 1 g of solid content was determined. I made it to the mountain.

[Molecular Weight]

Gel permeation chromatography (GPC) (HLC-8220GPC manufactured by Tosoh Corporation, solvent: tetrahydrofuran, column: TSKgelSuperH-2000 (2EA) + TSKgelSuperH-3000 (1EA) + TSKgelSuperH-4000 (1EA) + TSKgelSuper-H5000 (1 pc.) [made by Tosoh Corporation], temperature: 40°C, speed: 0.6ml/min}, measured in terms of standard polystyrene [PS-oligomer kit manufactured by Tosoh Corporation]], as a weight average It is the value which calculated|required molecular weight (Mw).

In addition, the abbreviations used in the synthesis examples and comparative synthesis examples are as follows.

FHPA: a reaction product of 9,9-bis(4-hydroxyphenyl)fluorene and chloromethyloxirane, and an equivalent reaction product of an epoxy group and a carboxyl group of acrylic acid (PGMEA solution of 50 wt% solid content)

BPDA: 3,3',4,4'-biphenyltetracarboxylic dianhydride

GMA: glycidyl methacrylate

THPA: 1,2,3,6-tetrahydrophthalic anhydride

TEAB: tetraethylammonium bromide

TPP: triphenylphosphine

PGMEA: Propylene glycol monomethyl ether acetate

The following Synthesis Examples 1 to 3 are represented by General Formula (1), and are examples of synthesis of alkali-soluble resins having a carboxyl group and a polymerizable unsaturated group in one molecule. In addition, Comparative Synthesis Examples 1 to 2 are alkali-soluble resins of the general formula (7) and alkali-soluble resins obtained by reacting an acid monohydride thereto, and the alkali-soluble resins of the general formula (1) are not included.

[Synthesis Example 1]

In a 1000 ml four-necked flask equipped with a reflux condenser, 600.0 g (0.49 mol) of 50% PGMEA solution of FHPA [(A) component], 72.8 g (0.25 mol) of BPDA [(B) component], and PGMEA 39.6 g and 1.30 g of TPP were added, followed by stirring for 2 hours under heating at 120 to 125°C, and heating and stirring at 70 to 75°C for 6 hours to obtain a reaction product (a). The solid content concentration of the obtained reaction product (a) was 52.4 wt%, the acid value of the resin was 78.0 mgKOH/g, and the molecular weight (Mw) was 3400.

Next, 73.9 g (0.52 mol) of GMA [(C) component] was put into this reaction product (a), and it stirred at 80 degreeC for 8 hours, and was made to react. Moreover, 156.7 g (1.0 mol) of THPA [(D) component] was put into the flask, and it stirred at 80 degreeC for 7 hours, and the alkali-soluble resin (i)-1 was synthesized. The obtained alkali-soluble resin had a solid content of 62.0 wt%, an acid value of 112 mgKOH/g, and a molecular weight (Mw) of 3700. In addition, (A) to (D) component names and blending ratios used in the synthesis of the alkali-soluble resin (i)-1 according to Synthesis Example 1, and the weight average molecular weight and acid value of the obtained alkali-soluble resin (i)-1 are summarized. It shows in Table 1 (the same applies also to the following synthesis examples).

[Synthesis Example 2]

The reaction was carried out in the same manner as in Synthesis Example 1, except that the added amount of THPA [component (D)] in Synthesis Example 1 was changed to 118.7 g (0.78 mol) to obtain an alkali-soluble resin (i)-2.

[Synthesis Example 3]

600.0 g (0.49 mol) of 50% PGMEA solution of FHPA [(A) component], 96.0 g (0.33 mol) of BPDA [(B) component], 4.36 g of PGMEA, and 1.02 g of TEAB was added, followed by stirring for 2 hours under heating at 120 to 125°C, and further heating and stirring at 60 to 65°C for 8 hours to obtain a reaction product (b). The solid content concentration of the obtained reaction product (b) was 57.8 wt%, the acid value was 91.6 mgKOH/g, and the molecular weight (Mw) was 8800.

Next, 93.8 g (0.66 mol) of GMA [(C) component] was put into this reaction product (b), and it stirred at 80 degreeC for 24 hours, and was made to react. Moreover, 153.7 g (1.0 mol) of THPA [(D) component] and 153.7 g of PGMEA were put into the flask, and it stirred at 80 degreeC for 24 hours, and the alkali-soluble resin (i)-3 was synthesize|combined. The obtained alkali-soluble resin had a solid content concentration of 59.2 wt%, an acid value of 127 mgKOH/g, and a molecular weight (Mw) of 6800.

[Comparative Synthesis Example 1]

FHPA 50% PGMEA solution 206.3 g (0.17 mol), BPDA 25.01 g (0.085 mol), THPA 12.9 g (0.085 mol), PGMEA 26.0 g, and TPP 0.45 g Then, the mixture was stirred for 6 hours under heating at 120 to 125°C to obtain Resin (i)-4. The solid content concentration of the obtained resin solution was 55.6 wt%, the acid value was 103 mgKOH/g, and the molecular weight (Mw) was 2600.

[Comparative Synthesis Example 2]

In a 1000 ml four-necked flask with a reflux condenser, 600.0 g (0.49 mol) of 50% PGMEA solution of FHPA, 96.0 g (0.33 mol) of BPDA, 4.36 g of PGMEA, and 1.02 g of TEAB were added, and at 120 to 125°C. The mixture was stirred under heating for 2 hours, and further heated and stirred at 60 to 65°C for 8 hours to obtain Resin (i)-5. The solid content concentration of the obtained resin solution was 57.8 wt%, the acid value was 91.0 mgKOH/g, and the molecular weight (Mw) was 8600.

Next, the present invention will be specifically described based on Examples and Comparative Examples by producing an insulating material, but the present invention is not limited thereto. Here, the raw materials and abbreviations used in the manufacture of the insulating materials of the following Examples and Comparative Examples are as follows.

(i)-1: alkali-soluble resin obtained in Synthesis Example 1

(i)-2: alkali-soluble resin obtained in Synthesis Example 2

(i)-3: Alkali-soluble resin obtained in Synthesis Example 3

(i)-4: alkali-soluble resin obtained in Comparative Synthesis Example 1

(i)-5: alkali-soluble resin obtained in Comparative Synthesis Example 2

(ii): dipentaerythritol hexaacrylate

(iii)-1: Ilga Cure-907 (manufactured by BASF)

(iii)-2: Michler Ketone

(iv): Tetramethylbiphenyl-type epoxy resin

Solvent: Propylene glycol monomethyl ether acetate

The above compounding components were blended in the proportions shown in Tables 2 and 3 to prepare the photosensitive resin compositions for insulating films of Examples 1 to 12 and Comparative Examples 1 to 8. In addition, the numerical values in Tables 2 and 3 all represent parts by mass.

[Evaluation of the photosensitive resin composition for insulating films of Examples 1 to 12 and Comparative Examples 1 to 8]

The photosensitive resin compositions for insulating films shown in Tables 2 and 3 were coated on a 125 mm x 125 mm glass substrate with a spin coater so that the film thickness after post-baking became 0.5 µm, 1.0 µm, 10 µm, or 30 µm, When a film thickness of 0.5 and 1.0 µm was obtained, it was prebaked at 80°C for 1 minute, and when a film thickness of 10 and 30 µm was obtained, it was prebaked at 110°C for 5 minutes to prepare a coated plate. Thereafter, through a photomask for pattern formation, ultraviolet rays having a wavelength of 365 nm were irradiated with a high-pressure mercury lamp of 500 W/cm 2 to perform a photocuring reaction of the exposed portion. Subsequently, the exposed coating plate was further developed for 30 seconds from the time when the pattern began to be revealed by a 0.8 wt% tetramethylammonium hydroxide (TMAH) aqueous solution and a shower phenomenon at 23°C, and further spray washed to form the coating film. The unexposed part was removed. Thereafter, heat curing treatment was performed at 230° C. for 30 minutes using a hot air dryer to obtain the insulating films according to Examples 1 to 12 and Comparative Examples 1 to 8.

The following evaluation was performed about the cured film obtained under the conditions shown above. In addition, when creating a cured film for a film thickness test, a residual film rate, a PCT resistance test, a heat resistance test, an alkali resistance test, and an acid resistance test, development, washing with water, and heat curing treatment were performed after the entire surface exposure without passing through a photomask.

(Film thickness)

A part of the applied film was cut and measured using a stylus-type step shape measuring device (trade name P-10 manufactured by KLA Tenchol).

(Remaining film rate)

The substrate after exposure and development was measured using a stylus-type step shape measuring device [brand name P-10, manufactured by KLA Tencol Co., Ltd.], and from the film thickness W2 (µm) after development and the film thickness W2 (µm) before development. The film remaining rate was calculated by the following equation.

Film remaining rate (%) = film thickness after development (µm)/film thickness before development (µm) x 100

(Taper shape)

The exposed and developed pattern was observed using a scanning electron microscope (trade name VE-7800 manufactured by KEYENCE Co., Ltd.) using a negative photomask having a via hole pattern of 10 to 100 μm.

◎: Cross-sectional shape maintains net taper

○: The cross-sectional shape is close to vertical

△: cross-section is reverse taper

X: The cross-sectional shape is reverse taper, and some peeling has occurred.

(Resolution)

The minimum via diameter that could be appropriately formed when exposed and developed using a negative photomask having a via hole pattern of 10 to 100 µm was measured with an optical microscope.

(PCT tolerance test)

A printed circuit board with a copper circuit formed on a glass epoxy substrate (a roughened copper surface of the copper circuit) was used instead of the glass substrate to form a coating film of the photosensitive resin composition for an insulating film, and subjected to front exposure, development, What was washed with water and heat-hardened was used as a conductor circuit test piece. Using this conductor circuit test piece, a moisture resistance reliability test of 192 hours was conducted under conditions of 121°C, 100% relative humidity, and 2 atmospheres, and the state of the coating film was visually determined based on the following criteria.

◎: There is no change at all.

○: Almost no change was observed.

△: It has changed a little.

X: Remarkable changes, such as swelling and swelling and falling off, are seen in the coating film.

(Heat resistance test)

Using a conductor circuit test piece, immerse it in a solder bath at 260°C for 30 seconds in accordance with the test method of JISC-6481, perform a peeling test with cellophane tape as one cycle, and repeat this one to three times. It observed and evaluated by the following criteria. The results are summarized in Tables 4 and 5.

(Double-circle): Even if it repeats 3 cycles, there is no abnormality in the coating film.

(Circle): After repeating 3 cycles, a change was observed in the coating film slightly.

?: After repeating 2 cycles, a change was observed in the coating film.

×: After repeating one cycle, a change was observed in the coating film.

(Alkaline resistance test)

A glass substrate with an insulating film is immersed in a solution maintained at 80°C of a mixture of 30 parts by mass of 2-aminoethanol and 70 parts by mass of glycol ether, then pulled up after 10 minutes, washed with pure water, dried, and a sample immersed in chemicals is prepared. Then, adhesion was evaluated. A crosscut was put on the film of the chemically immersed sample so as to have at least 100 checkerboard patterns, and then a peeling test was performed using a cellophane tape to evaluate the state of the checkerboard pattern visually.

◎: No peeling is seen at all

○: The peeling can be confirmed on the coating film slightly

△: Some coating films can be peeled off

X: The film is almost peeled off

(Acid resistance test)

A glass substrate with an insulating film is immersed in a solution maintained at 50°C in aqua regia (hydrochloric acid: nitric acid = 7:3), pulled up after 10 minutes, washed with pure water, dried, and a chemical immersed sample is prepared to evaluate adhesion. did.

◎: No peeling is seen at all

○: The peeling can be confirmed on the coating film slightly

△: Some coating films can be peeled off

X: The film is almost peeled off

In Examples, in the case of a thick film having a thickness of 30 µm, the residual film ratio is 98%, the resolution aspect ratio (film thickness/via diameter) is 0.9, which is good, and the results of each tolerance test are also good. Subsequently, for a 10 µm film, the residual film rate was 98%, the aspect ratio was 0.28 to 0.5, and the resistance test results were also good. In addition, in the example of a 1 µm thin film, the residual film ratio is 95%, the resolution has an aspect ratio of 0.1, and patterning properties sufficient for use as an insulating film, and the results of each resistance test are also approximately good. In addition, even in a 0.5 μm thin film, it is possible to form a very thin insulating film with a residual film rate of 95% and a resolution of 10 μm phi, and good results of each resistance test.

On the other hand, in the case of the comparative example, in the case of a 30 μm thick film, the results of each resistance test are good, but the residual film rate is lowered to less than 85%, and the resolution is also in the aspect ratio of 0.3 to 0.4, so that the patterning characteristic is not sufficiently obtained. Subsequently, in the comparative examples of the 10 μm film thickness, the results of each resistance test were almost good, but the residual film rate was less than 85% and the aspect ratio was 0.25 to 0.28, which lowered the patterning property compared to the case of using the alkali-soluble resin of the present invention. Has become. In addition, in the comparative example of a 1 μm thin film, when the molecular weight of the alkali-soluble resin is as small as 2600, the residual film rate is 60%, and each resistance test result is also poor, and even when the molecular weight of the alkali-soluble resin is large as 8600, each resistance test result is It is almost satisfactory, but it can be seen that the patterning characteristic is very insufficient due to the residual film ratio of 75% and the aspect ratio of 0.03. In addition, in the comparative example of a thin film of 0.5 µm, when the molecular weight of the alkali-soluble resin is as small as 2600, it is peeled off at the time of development and cannot be used as an insulating film, and even when the molecular weight of the alkali-soluble resin is as large as 8600, the residual film rate is 50%. It can be seen that the test result is also poor.

The photosensitive resin composition for an insulating film of the present invention has a higher number of ethylenically unsaturated bond groups in one molecule than the conventional one, so that the photocurability is improved, and the crosslinking density after curing can be increased without increasing the amount of the photopolymerization initiator. In other words, when the thick film is irradiated with ultraviolet rays or electron beams, since the cured portion is cured to the bottom portion, the difference in solubility in the alkali developer between the exposed portion and the unexposed portion increases, thereby improving the pattern dimensional stability, development margin, and pattern adhesion. Pattern can be formed. Further, even in the case of a thin film, since the sensitivity is increased, it is possible to significantly improve the amount of remaining film in the exposed portion or to suppress peeling during development. Therefore, the photosensitive composition for an insulating film of the present invention is very useful for a solder resist for preparing a circuit board, a plating resist, an etching resist, an insulating film for multilayering a wiring board on which a semiconductor element is mounted, a gate insulating film for an organic semiconductor, a photosensitive adhesive, etc. .

Claims (3)

(i) an alkali-soluble resin represented by the following general formula (1) and having a carboxyl group and a polymerizable unsaturated group in one molecule,

(However, R ₁ , R ₂ , R ₃ , and R ₄ independently represent a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a halogen atom or a phenyl group, and R ₅ represents a hydrogen atom or a methyl group. In addition, X is- CO-, -SO ₂ -, -C(CF ₃ ) ₂ -, -Si(CH ₃ ) ₂ -, -CH ₂ -, -C(CH ₃ ) ₂ -, -O-, 9,9-fluore Represents a nylene group or a direct bond, and Y represents a tetravalent carboxylic acid residue, G represents a substituent having a polymerizable double bond and a carboxyl group, or a group having a polymerizable double bond and a hydroxyl group Z is the following general formula The substituent represented by (2) or a hydrogen atom is represented, and n represents the number of 1-20)

(However, L represents a divalent or trivalent carboxylic acid residue, p is 1 or 2)
(ii) a photopolymerizable monomer having at least one ethylenically unsaturated bond,
(iii) a photopolymerization initiator, and
(iv) epoxy compound
A method of forming an insulating film of a desired pattern by applying, pre-baking, exposure, alkali development, and post-baking on a substrate with a photosensitive resin composition for an insulating film containing as an essential component, wherein the film thickness of the obtained insulating film is 0.5 to 1.0 µm And, the residual film rate before and after alkali development is 95% or more. The method of claim 1,
A photosensitive resin composition for an insulating film containing 0.1 to 10 parts by mass of the (iii) component and 10 to 40 parts by mass of the component (iv) per 100 parts by mass of the total of the (i) component and the (ii) component is used. Method for producing an insulating film delete