JP2017037116A - Photosensitive resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composition for MEMS, which can be thickly coated by increasing the resin concentration and has good adhesion, coatability and developability. SOLUTION: A hydrophilic resin (A) having a radically polymerizable group, a polyfunctional (meth) acrylate (B) having a hydrophilic base oil balance of 8 to 20, a photopolymerization initiator (C) and a solvent (D) are indispensable. A resin composition contained as a component, wherein the viscosity at 25 ° C. is 20 to 1,000 mPa · s, and the content of (D) is 10 to 50% by weight. A photosensitive resin composition is used. [Selection diagram] None

Description

  The present invention relates to a photosensitive resin composition. More specifically, the present invention relates to a photosensitive resin composition suitable for a microelectromechanical system (abbreviated as MEMS in the industry) that can be thickly applied at the time of coating.

  In recent years, MEMS, which is a device that integrates micro components such as mechanical component parts, sensors, actuators, and electronic circuits in the same chip using semiconductor integrated circuit creation technology, has been used not only in the information and communication fields but also in automobiles, home appliances, and medical care. Development in various fields such as biotechnology is expected. On the other hand, there is an increasing demand for miniaturization in each of these fields, and development of a photosensitive resin composition capable of forming a high-thickness and high-definition resist pattern is required.

When forming a resist pattern with a high film thickness as described above, it is necessary to form a thick coating film of the resin composition.
However, conventionally used resin compositions have a problem that it is difficult to form a coating having a sufficient thickness because of low viscosity. (Patent Document 1)

Therefore, in order to thicken the coating film of the resin composition, it is necessary to increase the concentration of the resin contained (Patent Document 2).
However, increasing the resin concentration increases the viscosity. When the viscosity increases, coating with a die coater used when applying a resin composition on a large substrate makes it difficult to apply from the nozzle of the die coater or forms a coating with a uniform thickness. There are issues that make it difficult to do.

JP 2012-98357 A JP 2010-32991 A

  An object of the present invention is to provide a resin composition for MEMS that can be thickly coated by increasing the resin concentration and has good adhesion, coating property, and developability.

The inventors of the present invention have reached the present invention as a result of studies to achieve the above object.
That is, the present invention relates to a hydrophilic resin (A) having a radical polymerizable group, a polyfunctional (meth) acrylate (B) having a hydrophilic / lipophilic balance of 8 to 20, a photopolymerization initiator (C) and a solvent (D). An alkali development characterized in that the viscosity of the resin composition is 20 to 1,000 mPa · s and the content of (D) is 10 to 50% by weight. A possible photosensitive resin composition; and a device for a microelectromechanical system formed by curing the photosensitive resin composition.

The photosensitive resin composition of the present invention can be coated thick because the resin concentration can be increased, and further has an effect that adhesion, coating property and developability are good.

The alkali-developable photosensitive resin composition of the present invention includes a hydrophilic resin (A) having a radical polymerizable group, a polyfunctional (meth) acrylate (B) having a hydrophilic / lipophilic balance of 8 to 20, and a photopolymerization initiator. It is a resin composition containing (C) and a solvent (D) as essential components. And the viscosity in 25 degreeC of a resin composition is 20-1,000 mPa * s, content of a solvent (D) is as small as 10-50 weight%, and it is the sum total of (A) and (B) relatively. It is characterized by a high content.

In this specification, “(meth) acrylate” means “acrylate or methacrylate”, “(meth) acrylic acid” means “acrylic acid or methacrylic acid”, and “(meth) acrylic resin” means “ “Acrylic resin or methacrylic resin”, “(meth) acryloyl group” means “acryloyl group or methacryloyl group”, and “(meth) acryloyloxy group” means “acryloyloxy group or methacryloyloxy group”.

The term “alkaline developable” means that the uncured portion can be removed with an alkaline aqueous solution of the developer in the step of removing the uncured portion using a developer.

Below, (A)-(D) which is an essential structural component of the photosensitive resin composition of this invention is demonstrated in order.

The hydrophilicity index in the hydrophilic resin (A) having a radically polymerizable group, which is the first essential component in the present invention, is defined by HLB. Generally, the larger this value, the higher the hydrophilicity.
The HLB value of the hydrophilic resin (A) of the present invention is preferably 4 to 19, more preferably 5 to 19, and particularly preferably 6 to 19. When it is 4 or more, the developing property is further improved when developing the photospacer, and when it is 19 or less, the water resistance of the cured product is further improved.

Here, “HLB” is an index indicating a balance between hydrophilicity and lipophilicity, and is described in, for example, “Introduction to Surfactants” (published by Sanyo Chemical Industries, Ltd., 2007, Takehiko Fujimoto), page 212. It is known as the calculated value by the Oda method, not the calculated value by the Griffin method.
The HLB value can be calculated from the ratio between the organic value and the inorganic value of the organic compound.
The organic value and the inorganic value for deriving HLB = 10 × inorganic / organic HLB can be calculated by using the values in the table described in “Introduction of Surfactant” on page 213.

Further, the solubility parameter (hereinafter referred to as SP value) [(unit is (cal / cm ³ ) ^1/2 ]) of the hydrophilic resin (A) is preferably 7 to 14, more preferably 8 to 13, particularly preferably. Is from 9 to 13. If it is 7 or more, the developability can be further improved, and if it is 14 or less, the water resistance of the cured product is further improved.

The SP value in the present invention is calculated by the method described in the following document proposed by Fedors et al.
"POLYMER ENGINEERING AND SCIENCE, February, 1974, Vol. 14, No. 2, Robert F. Fedors (pp. 147-154)"

  The hydrophilic resin (A) of the present invention has a radical polymerizable group in the molecule, and the radical polymerizable group is preferably a (meth) acryloyl group, a vinyl group or an allyl group from the viewpoint of photocurability. More preferably, a (meth) acryloyl group is mentioned.

  In addition, the functional group contributing to the hydrophilicity contained in the molecule of the hydrophilic resin (A) having a radical polymerizable group of the present invention is a carboxyl group, an epoxy group, a sulfonic acid group, a phosphorus group from the viewpoint of alkali developability. An acid group is preferable, and a carboxyl group is more preferable.

  Specific examples of the resin (A) having a radical polymerizable group that can be used in the present invention include an epoxy resin (A1) having a radical polymerizable group and a (meth) acrylic resin (A2) having a radical polymerizable group. ) And the like.

As the hydrophilic epoxy resin (A1) having a radical polymerizable group of the present invention, a commercially available epoxy resin is reacted with a compound having a radical polymerizable group, and further a compound having a hydrophilic functional group such as a carboxyl group is reacted. Can be synthesized.
For example, it is produced by reacting (meth) acrylic acid with a novolak type epoxy resin having an epoxy group in the molecule, and further reacting polycarboxylic acid such as phthalic acid or phthalic anhydride or polycarboxylic acid anhydride. A method is mentioned.

  The hydrophilic (meth) acrylic resin (A2) having a radical polymerizable group of the present invention is obtained by polymerizing a (meth) acrylic acid derivative by an existing method and further reacting a compound having a radical polymerizable group. be able to.

  As a method for producing the hydrophilic (meth) acrylic resin (A2), radical polymerization is preferable, and a solution polymerization method is preferable because the molecular weight can be easily adjusted.

  Examples of the monomer used for producing the hydrophilic (meth) acrylic resin (A2) include (meth) acrylic acid (a21) and (meth) acrylic acid ester (a22).

  Examples of the (meth) acrylate ester (a22) include methyl (meth) acrylate, butyl (meth) acrylate, (meth) acrylate-2-ethylhexyl, hydroxyethyl (meth) acrylate, isobornyl (meth) acrylate, and the like. Preferably, it is methyl (meth) acrylate.

  As a monomer constituting the hydrophilic (meth) acrylic resin (A2), an aromatic ring-containing vinyl compound (a23) is used in combination with (a21) and (a22) from the viewpoint of elastic recovery characteristics of the photosensitive resin composition. May be. Examples of such (a23) include styrene.

  In the hydrophilic (meth) acrylic resin (A2), it is preferable to introduce a (meth) acryloyl group into a side chain or a terminal as necessary for the purpose of further improving the elastic recovery property of the photospacer.

  Examples of the method for introducing a (meth) acryloyl group into the side chain include the following methods (1) and (2).

(1) A polymer is produced using a monomer having a group capable of reacting with an isocyanate group (such as a hydroxyl group or a primary or secondary amino group) in at least a part of (a21) or (a22); A method of reacting a compound [(meth) acryloyloxyethyl isocyanate etc.] having a (meth) acryloyl group and an isocyanate group.

(2) A polymer using a monomer having a functional group capable of reacting with an epoxy group (hydroxyl group, carboxyl group, primary or secondary amino group, etc.) in at least a part of (a21) or (a22) A method of producing and then reacting a compound having a (meth) acryloyl group and an epoxy group (such as glycidyl (meth) acrylate).

The number average molecular weight of the hydrophilic resin (A) of the present invention is 1,000 to 100,000, preferably 2,000 to 50,000.

The content of the hydrophilic resin (A) in the photosensitive resin composition of the present invention is 5 to 70% by weight based on the total weight of (A) to (D) from the viewpoints of developability and coatability. Preferably it is 10 to 65% by weight.

The polyfunctional (meth) acrylate (B) having a hydrophilic / lipophilic balance (the aforementioned HLB value) of 8 to 20 as the second essential component in the present invention is bifunctional (meth) acrylate (B1), trifunctional ( A meth) acrylate (B2), a 4-6 functional (meth) acrylate (B3), etc. are mentioned.
For example, bifunctional (meth) acrylate means that the number of (meth) acryloyl groups is two, and the same description method is used hereinafter.
The HLB value is

As bifunctional (meth) acrylate (B1), an alkylene oxide 0-30 mol adduct of a divalent or higher alcohol having 2 to 30 carbon atoms and an esterified product of (meth) acrylic acid, alkylene oxide 4-30 of bisphenol A Examples thereof include di (meth) acrylates of molar adducts.
Examples of such compounds include trimethylolpropane diacrylate (HLB value: 10.2), di (meth) acrylate of 10-methylene oxide adduct of trimethylolpropane (HLB value: 15.7), and 20 of trimethylolpropane. Di (meth) acrylate of mole ethylene oxide adduct (HLB value: 16.9), 30 mol ethylene oxide adduct of trimethylolpropane (HLB value: 17.4), glycerin diacrylate (HLB value: 13) .2), di (meth) acrylate of 10 mol ethylene oxide adduct of glycerin (HLB value: 17.2), di (meth) acrylate of 20 mol ethylene oxide adduct of glycerin (HLB value: 17.8), Diglycerol of 30 mol ethylene oxide adduct of glycerin (Meth) acrylate (HLB value: 18.1), di (meth) acrylate of 4 mol ethylene oxide adduct of bisphenol A (HLB value: 8.1), di (meth) of 10 mol ethylene oxide adduct of bisphenol A Examples thereof include acrylate (HLB value: 11.3), di (meth) acrylate (HLB value: 15.0) of 30 mol ethylene oxide adduct of bisphenol A, and the like.

As trifunctional (meth) acrylate (B2), C3-C30 or more (preferably 3-8 valence) alcohol and (meth) acrylic acid ester, C3-C30 trivalence or more ( Preferable examples include 1 to 30 moles of adducts of alkylene oxide of preferably 3 to 8 alcohols and esterified products of (meth) acrylic acid.
Examples of such a compound include triacrylate of glycerin (HLB value: 8.1), pentaerythritol triacrylate (HLB value: 11.0), and triacrylate of 3 mol ethylene oxide adduct of trimethylolpropane (HLB value: 10). .3), triacrylate of trimethylolpropane in 6 mol ethylene oxide adduct (HLB value: 12.2), triacrylate of 9 mol ethylene oxide adduct in trimethylolpropane (HLB value: 13.5), trimethylol Triacrylate of 15 mol ethylene oxide adduct of propane (HLB value: 14.9), Triacrylate of 20 mol ethylene oxide adduct of trimethylolpropane (HLB value: 15.6), 9 mol ethylene oxide adduct of glycerin No bird Acrylate (HLB value: 14.6), and the like.

As a 4-6 functional (meth) acrylate (B3), C5-C30 tetravalent or more (preferably 4-8 valence) alcohol and (meth) acrylic acid esterified substance, C5-C30 tetravalent Examples include the above-described (preferably 4-8 valent) alkylene oxide 1-30 mol adducts of alcohol and esterified products of (meth) acrylic acid.
As these compounds, dipentaerythritol pentaacrylate (HLB value: 9.4), pentaerythritol 4 mol ethylene oxide adduct tetraacrylate (HLB value: 11.4), dipentaerythritol 3 mol ethylene oxide adduct And hexaacrylate (HLB value: 9.6).

Among the polyfunctional (meth) acrylates (B), (B2) and (B3) are preferable from the viewpoint of forming a thick film.

Furthermore, among polyfunctional (meth) acrylates (B), from the viewpoint of developability, preferred are (meth) acrylates having an oxyalkylene group in the molecule, and more preferred are those having an oxyethylene group. (B) is particularly preferably an esterified product of (meth) acrylic acid of an ethylene oxide adduct of a polyhydric alcohol.

The HLB value of the polyfunctional (meth) acrylate (B) is 8-20. The HLB value of (B) is preferably 9 to 20, particularly preferably 10 to 20, from the viewpoint of developability.

  The content of the polyfunctional (meth) acrylate monomer (B) in the photosensitive resin composition of the present invention is 10 to 80% by weight based on the total weight of (A) to (D) from the viewpoint of curability. Preferably it is 20 to 70% by weight.

As the photoinitiator (C) which is the third essential component of the present invention, polymerization of the polymerizable unsaturated compound is initiated by exposure to radiation such as visible light, ultraviolet light, far infrared light, charged particle beam and X-ray. Any component that can generate a free radical may be used.

As the photopolymerization initiator (C), α-hydroxyalkylphenone type (C-1) (for example, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, etc.);
α-aminoalkylphenone type (C-2) (for example, (2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1 -(4-morpholinophenyl) -butanone-1 etc.);
Thioxanthone compound type (C-3) (for example, (isopropylthioxanthone, diethylthioxanthone, etc.);
Phosphate ester type (C-4) (for example, (2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, etc.);
Acyloxime type (C-5) (for example, 1,2-octanedione, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)], ethanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl]-, 1- (O-acetyloxime) and the like);
Examples thereof include benzyldimethyl ketal type (C-6) and the like; benzophenone type (C-7) (for example, benzophenone, 4-benzoyl-4′-methyldiphenyl sulfide and the like).

From the viewpoint of curability, the photopolymerization initiator (C) preferably has an absorbance at a wavelength of 400 nm or more, and more preferably has an extinction coefficient of 100 or more at a wavelength of 405 nm.
As the photopolymerization initiator (C) having absorbance at a wavelength of 400 nm or more, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one [Irgacure 369 (manufactured by BASF Corporation, Extinction coefficient at 405 nm: 280)], bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide [Irgacure 819 (manufactured by BASF, extinction coefficient at 405 nm: 899)], 2,4,6- Trimethylbenzoyl-diphenyl-phosphine oxide [Lucirin TPO (manufactured by BASF, extinction coefficient at 405 nm: 165)] and 1,2-octanedione 1- [4- (phenylthio)-, 2- (O-benzoyloxime) ] [Irgacure OXE01 (manufactured by BASF, extinction coefficient at 405 nm: 102)] I can get lost.

  The usage-amount of a photoinitiator (C) is 2 to 15 weight% from a viewpoint of sclerosis | hardenability and coloring of hardened | cured material based on the sum total of (A)-(D), Preferably it is 3 to 10 weight%.

The solvent (D), which is the fourth essential component of the present invention, is not particularly limited as long as it is intended to dissolve or disperse the solid content in the photosensitive resin composition.

Solvents include ketone solvents (cyclohexanone, etc.), ether solvents (including ether ester solvents and ether alcohol solvents) (propylene glycol monomethyl ether acetate, dimethyl diglycol, methoxybutyl acetate, etc.), ester solvents (butyl acetate, etc.), alcohol Examples include solvents (including ketone alcohol solvents) (1.3-butylene glycol, diacetone alcohol, etc.), ester solvents (ethyl lactate, etc.), ketone solvents (acetone, methyl ethyl ketone, etc.), and the like.

  Of the solvents, from the viewpoint of solubility, an ether solvent and an alcohol solvent are preferable, and propylene glycol monomethyl ether acetate is more preferable.

  The usage-amount of a solvent (D) is 10 to 50 weight% from a viewpoint of applicability | paintability and the applicability | paintability of a thick film based on the total weight of a resin composition, Preferably it is 15 to 45 weight%.

From the viewpoint of improving adhesiveness, the photosensitive resin composition of the present invention is a silane compound represented by the following general formula (1) having two or more hydrolyzable alkoxy groups in addition to (A) to (C). It is preferable to add at least one selected from the group consisting of (E1), polysiloxane (E2) obtained by polycondensation of this silane compound (E1), and (meth) acrylate (F) having a phosphate group.

In formula (1), R ¹ is selected from the group consisting of a (meth) acryloyloxyalkyl group, a glycidoxyalkyl group, a mercaptoalkyl group, and an aminoalkyl group in which the alkyl group has 1 to 6 carbon atoms. Represents an organic group of more than species

R ² represents an aliphatic saturated hydrocarbon group having 1 to 12 carbon atoms or an aromatic hydrocarbon group having 6 to 12 carbon atoms. Examples of the aliphatic saturated hydrocarbon group include a linear alkyl group, a branched alkyl group, and an alicyclic saturated hydrocarbon group. Among R ⁵ , examples of the aromatic hydrocarbon group include an optionally substituted aryl group, aralkyl group, and alkylaryl group.
R ² is preferably a linear alkyl group, branched alkyl group and aryl group from the viewpoint of curing reactivity, more preferably a linear alkyl group and an aryl group, particularly preferably a methyl group, an ethyl group and a phenyl group. And combinations thereof.

R ³ represents an alkyl group having 1 to 4 carbon atoms, and examples thereof include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, and a sec-butyl group, preferably a thermosetting reaction. From the viewpoint of properties, they are a methyl group and an ethyl group.

Since m is 0 or 1, the silane compound (E1) has two or more hydrolyzable alkoxy groups.

Examples of the hydrolyzable alkoxy group contained in the silane compound (E1) include a methoxy group, an ethoxy group, a propoxy group, and a phenoxy group.

In the general formula (1), examples of the silane compound having a (meth) acryloyloxyalkyl group as R ¹ include the following compounds.
Examples of the trifunctional silane compound in which m is 0, that is, three alkoxy groups include 3-methacryloyloxypropyltrimethoxysilane, 3-methacryloyloxypropyltriethoxysilane, 3-acryloyloxypropyltrimethoxysilane, 3- Examples include acryloyloxypropyltriethoxysilane.

Examples of the trifunctional silane compound in which m is 1, that is, two alkoxy groups include 3-methacryloyloxypropylmethyldimethoxysilane, 3-methacryloyloxypropylmethyldiethoxysilane, 3-acryloyloxypropylmethyldimethoxysilane, 3 -Acryloyloxypropylmethyldiethoxysilane and the like.

Examples of the silane compound having a glycidoxyalkyl group as R ¹ include the following compounds.
Examples of the trifunctional silane compound in which m is 0, that is, three alkoxy groups include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, and the like.

As the trifunctional silane compound having m of 1, that is, two alkoxy groups, 3-glycidoxy. Examples include propylmethyldimethoxysilane and 3-glycidoxypropylmethyldiethoxysilane.

Examples of the silane compound having a mercaptoalkyl group as R ¹ include the following compounds.
Examples of the trifunctional silane compound in which m is 0, that is, three alkoxy groups include 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, and the like.

Examples of the trifunctional silane compound in which m is 1, that is, two alkoxy groups include 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropylmethyldiethoxysilane, and the like.

Examples of the silane compound having an aminoalkyl group as R ¹ include the following compounds.
Examples of trifunctional silane compounds in which m is 0, that is, three alkoxy groups include N-2 aminoethyl γ-aminopropyltrimethoxysilane, N-2 aminoethyl γ-aminopropyltriethoxysilane, and 3-aminopropyltrimethoxy. Silane, 3-aminopropyltriethoxysilane, etc. are mentioned.

Examples of trifunctional silane compounds in which m is 1, that is, two alkoxy groups include N-2 aminoethyl γ-aminopropylmethyldimethoxysilane, N-2 aminoethyl γ-aminopropylmethyldiethoxysilane, and 3-aminopropylmethyl. Examples include dimethoxysilane and 3-aminopropylmethyldiethoxysilane.

Among the compounds (E1), a (meth) acryloyloxyalkyl group-containing trifunctional silane compound having three alkoxy groups and a glycidoxyalkyl group-containing trifunctional silane compound having three alkoxy groups are preferable. More preferred are 3-acryloyloxypropyltrimethoxysilane and 3-glycidoxypropyltrimethoxysilane.

The polysiloxane (E2) of the present invention is a polysiloxane obtained by polycondensation of the silane compound (E1) having two or more hydrolyzable alkoxy groups.
Examples of the polysiloxane (E2) of the present invention include 1,3-bis [3- (acryloyloxy) propyl] -1,3, dimethoxydisiloxane.

Moreover, the (meth) acrylate (F) which has a phosphoric acid group is arbitrarily compoundable by making phosphoric anhydride react with the alcohol which has a (meth) acryloyl group.
Specific examples include 2- (meth) acryloyloxyethyl acid phosphate and tri (meth) acryloyloxyethyl phosphate.

  The photosensitive resin composition of the present invention has a silane compound (E1) having two or more hydrolyzable alkoxy groups, a polysiloxane (E2) obtained by polycondensation of the silane compound (E1), and a phosphate group ( The total content of (meth) acrylate (F) is usually 0.2 to 15% by weight, preferably 0.5 to 12% by weight, based on the total weight of (A) to (F) from the viewpoint of adhesion. is there.

The photosensitive resin composition according to the present invention may further contain other components as necessary. Other components include leveling agents (G), inorganic fine particles (eg, titanium oxide, alumina, etc.), sensitizers, polymerization inhibitors, thickeners, and other additives (eg, silane coupling agents, fluorescence) Whitening agents, yellowing inhibitors, antioxidants, antifoaming agents and deodorizing agents).

A preferable forming step of obtaining a cured product from the photosensitive resin composition of the present invention is a step of applying a photosensitive resin composition on a substrate, irradiating with light, forming a pattern by alkali development, and performing post-baking. .
Formation of hardened | cured material is normally performed at the process of (1)-(5) below.

(1) The process of apply | coating the photosensitive resin composition of this invention on a board | substrate:
Examples of the coating method include roll coating, spin coating, spray coating, and slit coating.
Examples of the coating apparatus include a spin coater, an air knife coater, a roll coater, a bar coater, a die coater, a curtain coater, a gravure coater, and a comma coater.

(2) The applied photosensitive resin composition layer is dried by applying heat as necessary (pre-baking):
The drying temperature is preferably 20 to 120 ° C, more preferably 30 to 110 ° C.
The drying time is preferably 0.5 to 10 minutes, more preferably 1 to 8 minutes, and particularly preferably 1 to 5 minutes. Drying may be performed under reduced pressure or normal pressure.

(3) Step of exposing the photosensitive resin composition layer with actinic rays through a predetermined photomask:
Examples of the active light include visible light, ultraviolet light, and laser light. Examples of the light source include sunlight, a high-pressure mercury lamp, a low-pressure mercury lamp, a metal halide lamp, and a semiconductor laser.
Although it does not specifically limit as an exposure amount, Preferably it is 20-300 mJ / cm < ² >, and 20-150 mJ / cm < ² > is more preferable from a viewpoint of production cost.
In the step of performing exposure, a component having a (meth) acryloyl group in the photosensitive resin composition reacts to undergo photocuring reaction.

(4) After light irradiation, the unexposed portion is removed with a developer and development is performed:
As the developer, an alkaline aqueous solution is usually used. Examples of the alkaline aqueous solution include aqueous solutions of alkali metal hydroxides such as sodium hydroxide and potassium hydroxide; aqueous solutions of carbonates such as sodium carbonate, potassium carbonate and sodium hydrogencarbonate; hydroxytetramethylammonium and hydroxytetraethylammonium. And an aqueous solution of an organic alkali. These can be used alone or in combination of two or more,
In addition, a surfactant such as an anionic surfactant, a cationic surfactant, an amphoteric surfactant, and a nonionic surfactant can be added and used.
As a developing method, there are a dip method and a shower method, but the shower method is preferable. The temperature of the developer is preferably 20 to 45 ° C. The development time is appropriately determined according to the film thickness and the solubility of the photosensitive resin composition.

(5) Post-heating (post-baking) step:
The post-baking temperature is 50 to 280 ° C, preferably 100 to 250 ° C, and more preferably 150 to 240 ° C.
The post-baking time is 5 minutes to 2 hours, preferably 10 minutes to 1 hour, and more preferably 15 minutes to 45 minutes.

  Hereinafter, although an example and a comparative example explain the present invention further, the present invention is not limited to these. Hereinafter, unless otherwise specified, “%” represents “% by weight” and “parts” represents “parts by weight”.

Production Example 1 [Production of hydrophilic epoxy resin (A-1)]
Glass Kolben equipped with heating and cooling, stirring device, reflux condenser, dropping funnel and nitrogen inlet tube, 200 parts of cresol novolac type epoxy resin “EOCN-102S” (Epoxy equivalent 200 manufactured by Nippon Kayaku Co., Ltd.) and propylene 245 parts of glycol monomethyl ether acetate was charged and heated to 110 ° C. to dissolve uniformly. Subsequently, 76 parts of acrylic acid (1.07 mol part), 2 parts of triphenylphosphine and 0.2 part of p-methoxyphenol were charged and reacted at 110 ° C. for 10 hours.
The reaction product was further charged with 91 parts (0.60 mol part) of tetrahydrophthalic anhydride, reacted at 90 ° C. for 5 hours, and then the content of the hydrophilic resin with propylene glycol monomethyl ether acetate was 50% by weight. As a hydrophilic resin having an acryloyl group and a carboxyl group of the present invention, a 50% propylene glycol monomethyl ether acetate solution of a carboxyl group-containing cresol novolac type epoxy resin (A-1) was obtained.
The acid value in terms of pure content of this resin was 88.4, the number average molecular weight (Mn) by GPC was 2,200, the SP value was 11.3, and the HLB value was 6.4.

Production Example 2 [Production of hydrophilic acrylic resin (A-2)]
172 parts of propylene glycol monomethyl ether acetate was charged in a glass Kolben equipped with a heating and cooling device, a stirring device, a reflux condenser, a dropping funnel and a nitrogen introducing tube, and heated to 90 ° C. Here, 177 parts of methacrylic acid, 13 parts of methyl methacrylate, 395 parts of styrene, and further 207 parts of propylene glycol monomethyl ether acetate and 5 parts of dimethyl-2,2′-azobis (2-methylpropionate) And 12 parts of propylene glycol monomethyl ether acetate were mixed dropwise, and radical polymerization was performed in glass Kolben to obtain an acrylic resin.
The acrylic resin was further charged with 19 parts of glycidyl methacrylate, reacted at 90 ° C. for 5 hours, and then diluted with propylene glycol monomethyl ether acetate so that the hydrophilic resin content was 50% by weight. A 50% propylene glycol monomethyl ether acetate solution of the acrylic resin (A2-1) having a group was obtained.
The acid value of this resin in terms of pure component was 100.2, Mn was 5,800, SP value was 10.5, and HLB value was 5.8.

Example 1
According to the number of parts (parts by weight) in Table 1, a 50% propylene glycol monomethyl ether acetate solution of the hydrophilic epoxy resin (A-1) produced in Production Example 1 in a glass container, (B-1), (B- 3), (B-4), (C-1), (D-1), (E1-1), (E2-1), (F-1), (G-1) are charged and uniform. And an additional solvent (propylene glycol monomethyl ether acetate) was added to obtain a photosensitive resin composition of Example 1.

Examples 2-5 and Comparative Examples 1-6
The photosensitive resin composition of Examples 2-5 and Comparative Examples 1-6 was obtained by the same operation as Example 1 by the mixing | blending part number of Table 1.

The details of the abbreviated chemicals in Table 1 are as follows.
(B-1): 4 mol ethylene oxide adduct tetraacrylate of pentaerythritol (“SR494” manufactured by Sartomer) (HLB value: 11.4)
(B-2): Triacrylate of 2.6 mol ethylene oxide adduct of trimethylolpropane (“Neomer TA-401” manufactured by Sanyo Chemical Industries) (HLB value: 9.9)
(B-3): Triacrylate of 20 mol ethylene oxide adduct of trimethylolpropane (“SR415” manufactured by Sartomer) (HLB value: 15.6)
(B-4): Pentaerythritol triacrylate (“Light acrylate PE-3A” manufactured by Kyoeisha Chemical Co., Ltd.) (HLB value: 11.0)
(B′-1): Pentaerythritol tetraacrylate (“Neomer EA-300” manufactured by Sanyo Chemical Industries) (HLB value: 7.8)

(C-1): (Bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide (“Irgacure 819” manufactured by BASF, extinction coefficient at 405 nm: 899) (C-2): 2,4 6-Trimethylbenzoyl-diphenyl-phosphine oxide ("Lucirin TPO" manufactured by BASF, extinction coefficient at 405 nm: 165)
(C-3): 1,2-octanedione 1- [4- (phenylthio)-, 2- (O-benzoyloxime)] (“Irgacure OXE-01, extinction coefficient at 405 nm: 102” manufactured by BASF)

(D-1) Propylene glycol monomethyl ether acetate (D-2) Diethylene glycol dimethyl ether

(E1-1): 3-acryloxypropyltrimethoxysilane ("KBM-5103": manufactured by Shin-Etsu Chemical Co., Ltd., three hydrolyzable groups)
(E2-1): Acrylic-modified alkoxypolysiloxane (“KR-513”: manufactured by Shin-Etsu Chemical Co., Ltd., containing many hydrolyzable groups)
(F-1): 2-acryloyloxyethyl acid phosphate (acrylic modified phosphate ester; “light acrylate P-1A”: manufactured by Kyoeisha Chemical Co., Ltd.)
(G-1): Polyether-modified polydimethylsiloxane (surfactant) (“KF-352A” manufactured by Shin-Etsu Chemical Co., Ltd.)
(G-2): Polyether-modified fluorine compound (surfactant) (“Megafac TF-2066” manufactured by DIC)

Below, the method of performance evaluation of developability, thick coating property, image development adhesiveness, and coating property, and the preparation method of the test piece (cured material) for it are demonstrated.

[Evaluation of developability]
A photosensitive resin composition was applied onto a 10 cm × 10 cm square glass substrate by a spin coater and dried (prebaked) to form a coating film having a dry film thickness of 5 μm. The obtained coating film was exposed to light of an ultrahigh pressure mercury lamp through a mask for forming a photospacer at 100 mJ / cm ² (illuminance 22 mW / cm ^{2 in} terms of i-line) to obtain a cured film.
Thereafter, alkali development was carried out for 30 seconds using a 0.05% KOH aqueous solution to evaluate the developability.

Judgment criteria are as follows.
A: There is no residue visually.
○: There is a slight residue visually.
Δ: There are many residues by visual inspection.
X: Development is not possible.

[Evaluation of thick coatability]
The photosensitive resin composition was applied to a 10 cm × 10 cm square glass substrate by a spin coater and dried (pre-baked) to form a coating film so that the dry film thickness was 5 μm to 10 μm to 50 μm. Exposure was carried out at 100 mJ / cm ² through a mask having slits every 100 μm to obtain a cured film, and development and post-baking were performed.
The slit portion of this substrate was observed with a laser microscope, and the portion where the pattern collapsed was confirmed.

Judgment criteria are as follows.
(Double-circle): There is no part which has fallen even at 50 micrometers.
◯: There is no part that falls below 40 μm.
(Triangle | delta): There is no location which has fallen below 30 micrometers.
X: There exists a part which has fallen below 30 micrometers.

[Evaluation of development adhesion]
The photosensitive resin composition was applied to a 10 cm × 10 cm square glass substrate by a spin coater and dried (prebaked) to form a coating film having a dry film thickness of 5 μm. The obtained coating film was irradiated with light of an ultrahigh pressure mercury lamp through a mask for forming a photospacer at 100 mJ / cm ² (illuminance 22 mW / cm ^{2 in} terms of i-line).
In addition, it exposed with the space | interval (exposure gap) of a mask and a board | substrate 100 micrometers.
Thereafter, development was performed for 90 seconds using a 0.05% aqueous KOH solution, and the development adhesion was evaluated.

Judgment criteria are as follows.
◎: No peeling with photomask opening diameter of 10 μm ○: No peeling with photomask opening diameter of 12 μm (Peeling off at 10 μm)
Δ: No peeling with photomask opening diameter of 16 μm (Peeling with 10 μm and 12 μm)
×: Photomask opening diameter is 16 μm and there is peeling

[Evaluation of coatability]
An injection needle (outer diameter 0.6 mm, length 26 mm) was attached to the tip of a 200 mL glass syringe with a lock fitting, and 100 mL of the photosensitive resin composition was put therein and pressed with a constant force (5 N).

Judgment criteria are as follows.
◎: The whole amount could be applied without clogging. ○: There was a slight clogging, but the whole amount could be applied. △: Clogged in the middle of coating.

As shown in Table 1, the photosensitive resin compositions of Examples 1 to 6 of the present invention are excellent in all evaluation items of developability, thick coatability, coating property, and adhesion.
On the other hand, Comparative Example 1 that does not contain (A) does not satisfy the developability and coating, and in the case that it does not contain (B), in Comparative Example 2 where there are many (A), the coating property is poor. In Comparative Example 3 with a small amount of), the developability deteriorates. In Comparative Example 4 with a small amount of solvent, the coating property is poor, and in Comparative Example 5 with a large amount of solvent, the thick coating property is insufficient. Furthermore, in the comparative example 6 whose viscosity is too high, the coatability is insufficient.

The photosensitive resin composition of the present invention is excellent in adhesion, coating property, and developability, and can be used as a cured product necessary for forming a MEMS device component because it can be thickly applied.
Here, MEMS (microelectromechanical system) refers to a system in which fine components such as mechanical element parts, sensors, actuators, and electronic circuits are integrated in the same chip by using a semiconductor integrated circuit creation technique.

Claims (5)

  Resin composition containing a hydrophilic resin (A) having a radical polymerizable group, a polyfunctional (meth) acrylate (B) having a hydrophilic / lipophilic balance of 8 to 20, a photopolymerization initiator (C) and a solvent (D) The alkali-developable photosensitive resin composition having a viscosity at 25 ° C. of 20 to 1,000 mPa · s and a content of (D) of 10 to 50% by weight. The photosensitive resin composition of Claim 1 in which a polyfunctional (meth) acrylate (B) contains the polyfunctional (meth) acrylate which has an oxyalkylene chain in a molecule | numerator. The photosensitive resin composition of Claim 1 or 2 in which a photoinitiator (C) contains the initiator which has a light absorbency in the wavelength range of 400 nm or more. Further, a group consisting of a silane compound (E1) represented by the following general formula (1), a polysiloxane (E2) obtained by polycondensation of the silane compound (E1), and a (meth) acrylate (F) having a phosphate group. The photosensitive resin composition in any one of Claims 1-3 containing 1 or more types chosen from more.
[Wherein, R ¹ is one or more selected from the group consisting of a (meth) acryloyloxyalkyl group, a glycidoxyalkyl group, a mercaptoalkyl group, and an aminoalkyl group in which the alkyl group has 1 to 6 carbon atoms. R ² represents an aliphatic saturated hydrocarbon group having 1 to 12 carbon atoms or an aromatic hydrocarbon group having 6 to 12 carbon atoms, and R ³ represents an alkyl group having 1 to 4 carbon atoms. M is 0 or 1. ]. A device for a micro electro mechanical system obtained by curing the photosensitive resin composition according to claim 1.