JP6639170B2 - Insulating film for circuit board and method of manufacturing the same - Google Patents

Description

  The present invention relates to an insulating film for a circuit board and a method for manufacturing the same.

  Polyimide resin (photosensitive resin composition) designed to have photosensitivity is used as an insulating film or protective coating agent on a semiconductor device, or a substrate or surface protective material such as a flexible printed circuit board or an integrated circuit board. Further, it is used as a material of an interlayer insulating film or a protective film of a fine circuit.

  When the photosensitive resin composition is used as a solder resist which is a surface protection material (insulating film) for a circuit board such as a printed circuit board, the solder resist is subjected to fine patterning such as a photolithography method. Must have high photosensitivity. In recent years, this photosensitive solder resist has, for example, coloring properties for concealing circuits, flexibility corresponding to a flexible printed circuit board, or high resolution corresponding to a highly integrated circuit board, Such multifunctionality is required.

  In order to ensure such multifunctionality, various functional particles are added to the photosensitive resin composition. For example, a pigment and a flexible filler are added to the photosensitive resin composition described in Patent Literature 1 in order to develop coloring property and flexibility, and the photosensitive resin composition described in Patent Literature 2 has a high resolution. An appropriate initiator is added to develop image properties.

JP 2014-052430 A JP 2014-191001 A

  However, when the photosensitive resin composition contains many functional particles such as a pigment or a flexible filler, the light is absorbed by the functional particles (e.g., ultraviolet light), reflected, or scattered, so that the light becomes photosensitive. The resin composition does not sufficiently reach the bottom of the film, making it difficult to form a fine pattern.

  Further, when the photosensitive resin composition contains a large amount of functional particles such as a photo-radical polymerization initiator, the amount of outgas generated by the functional particles increases, thereby causing process contamination. In addition, when a pigment, a flexible filler or the like is contained, the amount of the photoradical polymerization initiator used further increases, so that the process contamination becomes a problem.

  Above all, in the case of a photosensitive resin composition using such functional particles, if the film is a thick film, light attenuates as it proceeds to the bottom of the film, so that the light sufficiently reaches the bottom of the film. Without this, it becomes extremely difficult to form a fine pattern.

  The present invention has been made to solve the above problems. An object of the present invention is to provide an insulating film for a circuit board and the like formed of a photosensitive resin composition capable of sufficiently transmitting light for exposure.

  The insulating film for a circuit board is formed of a photosensitive resin composition containing at least (A) a binder polymer, (C) a radically polymerizable monomer, (D) a photoradical polymerization initiator, and (E) a light emitting material. .

  According to the present invention, an insulating film or the like for a circuit board formed of a photosensitive resin composition that allows light for exposure to sufficiently reach.

FIG. 4 is a schematic diagram showing a state in which the warpage of the insulating film is being measured.

  An embodiment of the present invention will be described. The photosensitive resin composition that becomes the insulating film for a circuit board contains at least (A) a binder polymer, (C) a radically polymerizable monomer, (D) a photoradical polymerization initiator, and (E) a luminescent material. Then, the photosensitive resin composition becomes an insulating film for a circuit board that allows exposure light such as a photolithography method to sufficiently reach inside, and it is presumed that this is due to a light emitting material.

  In general, a light-emitting material emits light, that is, energy when it returns to a ground state by being excited by absorbing light of a certain wavelength (e.g., ultraviolet light). In the case of the photosensitive resin composition as described above, the photo-radical polymerization initiator, by absorbing this energy, is presumed that the photo-crosslinking reaction proceeds to the bottom of the film of the photosensitive resin composition. . Due to such a phenomenon, it is presumed that the insulating film formed of such a photosensitive resin composition exhibits excellent resolution by patterning by photolithography or the like.

  The photosensitive resin composition containing at least (A) a binder polymer, (C) a radically polymerizable monomer, (D) a photoradical polymerization initiator, and (E) a luminescent material, and (B) a thermosetting resin When the photosensitive resin composition is contained, it is preferable that the photosensitive resin composition is formed as an insulating film for a circuit board and hardened by applying heat, since characteristics required for the insulating film are easily obtained.

  Hereinafter, (A) a binder polymer, (B) a thermosetting resin, (C) a radical polymerizable monomer, (D) a radical photopolymerization initiator, and (E) a light emitting material will be described.

<(A) Binder polymer>
The binder polymer is soluble in an organic solvent and has a weight average molecular weight of 1,000 or more and 1,000,000 or less in terms of polyethylene glycol.

  Although the organic solvent is not particularly limited, for example, a sulfoxide solvent such as dimethyl sulfoxide or diethyl sulfoxide, a formamide solvent such as N, N-dimethylformamide or N, N-diethylformamide, N, N-dimethylacetamide or N, N-dimethylacetamide Examples thereof include acetamido solvents such as N-diethylacetamide, pyrrolidone solvents such as N-methyl-2-pyrrolidone and N-vinyl-2-pyrrolidone, hexamethylphosphoramide, and γ-butyrolactone. Further, if necessary, these organic polar solvents may be combined with an aromatic hydrocarbon such as xylene or toluene.

Furthermore, for example, methyl monoglyme (1,2-dimethoxy ethane), methyl diglyme (bis (2-methoxy ethoxy) ether), methyl triglyme (1,2-bis (2-methoxy ethoxy) ethane), methyl tetraglyme Glyme (bis [2- (2-methoxyethoxyethyl)] ether), ethyl monoglyme (1,2-diethoxyethane), ethyl diglyme (bis (2-ethoxyethyl) ether), butyl diglyme (bis ( Symmetric glycol diethers such as 2-butoxyethyl) ether),
Methyl acetate, ethyl acetate, isopropyl acetate, n-propyl acetate, butyl acetate, propylene glycol monomethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate (also known as carbitol acetate, 2- (2-butoxyethoxy) acetate Ethyl)), diethylene glycol monobutyl ether acetate, 3-methoxybutyl acetate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, dipropylene glycol methyl ether acetate, propylene glycol diacetate, 1,3-butylene glycol diacetate, etc. Acetates,
Or dipropylene glycol methyl ether, tripropylene glycol methyl ether, propylene glycol n-propyl ether, dipropylene glycol n-propyl ether, propylene glycol n-butyl ether, dipropylene glycol n-butyl ether, propylene glycol n-propyl ether, Organic solvents such as propylene glycol phenyl ether, dipropylene glycol dimethyl ether, 1,3-dioxolan, ethylene glycol monobutyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, and ethylene glycol monoethyl ether are exemplified.

  Organic solvent solubility, which is an indicator of solubility in an organic solvent, can be measured as parts by weight of a base polymer dissolved in 100 parts by weight of an organic solvent, and a base polymer dissolved in 100 parts by weight of an organic solvent Is 5 parts by weight or more, it is considered to be soluble in an organic solvent.

  The method for measuring the solubility of the organic solvent is not particularly limited. For example, 5 parts by weight of a base polymer is added to 100 parts by weight of an organic solvent, and the mixture is stirred at 40 ° C. for 1 hour, cooled to room temperature and left for 24 hours or more to form a uniform solution without generating insolubles and precipitates. It is measured by a method that confirms that

  The weight average molecular weight of the binder polymer is measured, for example, by the following method.

(Weight average molecular weight measurement)
Apparatus used: Tosoh HLC-8220GPC equivalent column: Tosoh TSK gel Super AWM-H (6.0 mm ID × 15 cm) x 2 guard columns: Tosoh TSK guard column Super AW-H
Eluent: 30 mM LiBr + 20 mM H3PO4 in DMF
Flow rate: 0.6 mL / min
Column temperature: 40 ° C
Detection conditions: RI: polarity (+), response (0.5 sec)
Sample concentration: about 5mg / mL
Standard: PEG (polyethylene glycol).

  When the weight average molecular weight is controlled so as to be 1,000 or more and 1,000,000 or less, the insulating film containing the binder polymer can have improved flexibility or chemical resistance. When the weight average molecular weight of the binder polymer is 1,000 or less, the flexibility or chemical resistance of the insulating film is reduced, and when the weight average molecular weight is 1,000,000 or more, the viscosity of the photosensitive resin composition is reduced. This is because it is difficult to form a high-quality insulating film in terms of shape.

  The binder polymer is not particularly limited. For example, polyurethane resin, poly (meth) acrylic resin, polyvinyl resin, polystyrene resin, polyethylene resin, polypropylene resin, polyimide resin, polyamide resin, polyacetal resin, polycarbonate resin, polyester resin, Examples include a polyphenylene ether-based resin, a polyphenylene sulfide-based resin, a polyether sulfone-based resin, and a polyether ether ketone-based resin. These may be used alone or in combination of two or more.

  Among these, when a polyurethane resin or a poly (meth) acrylic resin which is a resin containing a urethane bond in a molecule is used, an insulating film obtained by curing a photosensitive resin composition is excellent. It has excellent flexibility or breaking resistance, and warpage is suppressed. Hereinafter, these polyurethane resins and poly (meth) acrylic resins will be described in detail.

≪Polyurethane resin≫
A polyurethane resin that is a resin containing a urethane bond in a molecule is soluble in an organic solvent, contains a repeating unit containing at least one urethane bond in the molecule, and further has a weight average molecular weight of: It should be 1,000 or more and 1,000,000 or less in terms of polyethylene glycol.

（式中、Ｒ_１は２価の有機基を示す） The resin containing a urethane bond in the molecule can be obtained by any reaction. For example, a resin containing a diol compound represented by the following general formula (1):

(Wherein, R ₁ represents a divalent organic group)

（式中、Ｘ_１は２価の有機基を示す） By reacting with a diisocyanate compound represented by the following general formula (2),

(Wherein, X ₁ represents a divalent organic group)

（式中、Ｒ_１およびＸ_１はそれぞれ独立に２価の有機基を示し、ｎは１以上の整数を示す） It has a structure containing a repeating unit having a urethane bond represented by the following general formula (3).

(Wherein, R ₁ and X ₁ each independently represent a divalent organic group, and n represents an integer of 1 or more)

  The diol compound is not particularly limited as long as it has the above-mentioned structure [general formula (1)]. For example, ethylene glycol, diethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, 1,6- Hexanediol, 1,8-octanediol, 2-methyl-1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol and the like Polyoxyalkylene diols such as alkylene diols, polyethylene glycols, polypropylene glycols, polytetramethylene glycols, random copolymers of tetramethylene glycol and neopentyl glycol, polyoxyalkylene diols, polyhydric alcohols and polybasic acids. Ethylene oxide adducts of polycaprolactone diol, bisphenol A, bisphenol A obtained by subjecting lactones such as ester diol, polycarbonate diol having a carbonate skeleton, γ-butyl lactone, ε-caprolactone, δ-valerolactone to ring-opening addition reaction Propylene oxide adduct of bisphenol A, hydrogenated bisphenol A, ethylene oxide adduct of hydrogenated bisphenol A, or propylene oxide adduct of hydrogenated bisphenol A. These may be used alone or in combination of two or more.

  Among them, when a long-chain diol such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polyoxyalkylene diol, polyester diol, polycarbonate diol, or polycaprolactone diol is used, the photosensitive resin composition is cured. This lowers the elastic modulus of the obtained insulating film. Therefore, the insulating film has excellent flexibility or low warpage.

Also, the diisocyanate compound is not particularly limited as long as it has the above-mentioned structure [General formula (2)]. For example, diphenylmethane-2,4'-diisocyanate, 3,2'- or 3,3'- or 4,2'- or 4,3'- or 5,2'- or 5,3'- or 6,2 '-Or 6,3'-dimethyldiphenylmethane-2,4'-diisocyanate, 3,2'- or 3,3'- or 4,2'- or 4,3'- or 5,2'- or 5, 3'- or 6,2'- or 6,3'-diethyldiphenylmethane-2,4'-diisocyanate, 3,2'- or 3,3'- or 4,2'- or 4,3'- or 5 , 2'- or 5,3'- or 6,2'- or 6,3'-dimethoxydiphenylmethane-2,4'-diisocyanate, diphenylmethane-4,4'-diisocyanate, diphenylmethane-3,3'-diisocyanate , Diphenylmethane-3,4'-diisocyanate, diphenylether-4,4'-diisocyanate, benzophenone-4,4'-diisocyanate, diphenylsulfone-4,4'-diisocyanate, tolylene-2,4-diisocyanate, tolylene-2 Aromatic diisocyanates such as 2,6-diisocyanate, m-xylylene diisocyanate, p-xylylene diisocyanate, naphthalene-2,6-diisocyanate, 4,4 '-[2,2-bis (4-phenoxyphenyl) propane] diisocyanate Compound,
Alicyclic diisocyanate compounds such as hydrogenated diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate, norbornene diisocyanate,
Alternatively, aliphatic diisocyanate compounds such as hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, and lysine diisocyanate may be used. These may be used alone or in combination of two or more.

  Among them, when an alicyclic diisocyanate or an aliphatic diisocyanate compound is used, the photosensitivity of the photosensitive resin composition increases.

  The method for synthesizing a resin containing a urethane bond in the molecule is such that the ratio of the number of hydroxyl groups to the number of isocyanate groups is 0.5 or more and 2.0 or less. And obtained by reacting in the absence of a solvent or in an organic solvent.

  When two or more diol compounds are used, the reaction between them and the diisocyanate compound may be performed after mixing the two or more diol compounds, or each diol compound and the diisocyanate compound may be separately reacted. You may.

  Further, after reacting the diol compound with the diisocyanate compound, the obtained terminal isocyanate compound may be further reacted with another diol compound, and further reacted with the diisocyanate compound. The same applies when two or more diisocyanate compounds are used.

  The reaction temperature between the diol compound and the diisocyanate compound is preferably from 40 ° C to 160 ° C, more preferably from 60 ° C to 150 ° C. This is because if the temperature is lower than 40 ° C., the reaction time becomes too long, while if the temperature exceeds 160 ° C., a three-dimensional reaction occurs during the reaction and gelation occurs.

  The reaction time may be appropriately selected depending on the scale of the batch or the reaction conditions employed. If necessary, the reaction may proceed in the presence of a catalyst such as a tertiary amine, an alkali metal, an alkaline earth metal, a metal such as tin, zinc, titanium and cobalt, or a metalloid compound.

  The above reaction may be carried out without a solvent, but is preferably carried out in an organic solvent system in order to control the reaction. Although the organic solvent used here is not particularly limited, for example, the above-mentioned ones may be used.

  The amount of the organic solvent used in the above reaction is preferably such that the solute weight concentration in the reaction solution, that is, the solution concentration is 5% by weight or more and 90% by weight or less, and 10% by weight or more and 80% by weight. More preferably, the amount is as follows. This is because, when the solution concentration is 5% or less, the polymerization reaction hardly occurs, the reaction rate is reduced, and a desired structural substance cannot be obtained.

  Further, the resin containing a urethane bond in the molecule preferably further contains at least one organic group selected from the group consisting of a (meth) acryloyl group, a carboxyl group, and an imide group.

  The (meth) acryloyl group is at least one of an acryloyl group and a methacryloyl group. When the (meth) acryloyl group is contained, the photosensitivity of the photosensitive resin composition is improved. Then, the photosensitive resin composition is cured.

  Further, when the photosensitive resin composition contains a carboxyl group, the solubility of the photosensitive resin composition in a dilute aqueous alkali solution in a developing solution is improved, so that a fine pattern can be formed in a short time of development.

  In addition, when an imide group is contained, the heat resistance of the photosensitive resin composition or the electrical insulation reliability under high-temperature and high-humidity conditions are improved. A plate is obtained.

  Incidentally, a resin containing a urethane bond in a molecule containing a (meth) acryloyl group can be obtained by any reaction. For example, in addition to the diol compound and the diisocyanate compound, a resin represented by the following general formula (4): And at least one of the following general formulas (5). The following general formula (4) is a compound containing a hydroxyl group and at least one (meth) acryloyl group, and the following general formula (5) Is a compound containing an isocyanate group and at least one (meth) acryloyl group.

（式中、Ｒ_２はｍ＋１価の有機基を示し、Ｒ_３は水素またはアルキル基を示す。ｍは１〜３の整数を示す）

(Wherein, R ₂ represents an m + 1-valent organic group, R ₃ represents hydrogen or an alkyl group, and m represents an integer of 1 to 3)

（式中、Ｘ_２はｌ＋１価の有機基を示し、Ｘ_３は水素またはアルキル基を示す。ｌは１〜３の整数を示す）

(Wherein, X ₂ represents an l + 1-valent organic group, X ₃ represents hydrogen or an alkyl group, and l represents an integer of 1 to 3)

  The compound containing a hydroxyl group and at least one (meth) acryloyl group is not particularly limited as long as it has the above-mentioned structure [general formula (4)]. For example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, 2-hydroxy-1-acryloxy- 3-methacryloxypropane, o-phenylphenol glycidyl ether (meth) acrylate, polyethylene glycol mono (meth) acrylate, pentaerythritol tri (meth) acrylate, tris (2-hydroxyethyl) isocyanurate di (meth) acrylate, 1, 4-cyclohexanedimethanol mono (meth) acrylate, 4-hydroxyphenyl (meth) acrylate, 2- (4-hydroxyphenyl) ethyl (meth) acrylate, N-methylol acrylate Amides, or 3,5-dimethyl-4-hydroxybenzyl acrylamide, and the like. These may be used alone or in combination of two or more.

  The compound containing an isocyanate group and at least one (meth) acryloyl group is not particularly limited as long as it has the above-mentioned structure [general formula (5)]. For example, 2- (meth) acryloyloxyethyl isocyanate, 1,1- (bisacryloyloxymethyl) ethyl isocyanate, 2- (2-methacryloyloxyethyloxy) ethyl isocyanate and the like can be mentioned. These may be used alone or in combination of two or more.

  The resin containing a urethane bond in the molecule containing a carboxyl group can be obtained by any reaction. For example, in addition to the diol compound and the diisocyanate compound, the resin is represented by the following general formula (6). It is obtained by reacting a compound containing two hydroxyl groups and one carboxyl group.

（式中、Ｒ_４は３価の有機基を示す）
で示される２つの水酸基および１つのカルボキシル基を含有する化合物を反応させることにより得られる。

(Wherein, R ₄ represents a trivalent organic group)
By reacting a compound containing two hydroxyl groups and one carboxyl group represented by

  The compound containing two hydroxyl groups and one carboxyl group is not particularly limited as long as it has the above-mentioned structure [general formula (6)]. For example, 2,2-bis (hydroxymethyl) propionic acid, 2,2-bis (2-hydroxyethyl) propionic acid, 2,2-bis (3-hydroxymethyl) propionic acid, 2,3-dihydroxy-2 -Methylpropionic acid, 2,2-bis (hydroxymethyl) butanoic acid, 2,2-bis (2-hydroxyethyl) butanoic acid, 2,2-bis (3-hydroxypropyl) butanoic acid, 2,3-dihydroxy Butanoic acid, 2,4-dihydroxy-3,3-dimethylbutanoic acid, 2,3-dihydroxyhexadecanoic acid, 2,3-dihydroxybenzoic acid, 2,4-dihydroxybenzoic acid, 2,5-dihydroxybenzoic acid, , 6-dihydroxybenzoic acid, 3,4-dihydroxybenzoic acid, and 3,5-dihydroxybenzoic acid. These may be used alone or in combination of two or more. It is preferable to use a compound containing two aliphatic hydroxyl groups and one carboxyl group as described above because the photosensitive resin composition has excellent photosensitivity.

  The resin containing a urethane bond in the molecule containing an imide group can be obtained by any reaction. For example, in addition to the diol compound and the diisocyanate compound, the resin is represented by the following general formula (7). It is obtained by reacting tetracarboxylic dianhydride.

（式中、Ｙは４価の有機基を示す）

(Wherein, Y represents a tetravalent organic group)

  The tetracarboxylic dianhydride is not particularly limited as long as it has the above-mentioned structure [general formula (7)]. For example, 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride, pyromellitic dianhydride, 3,3 ′, 4,4′-oxydiphthalic dianhydride, 2,2-bis [4 -(3,4-dicarboxyphenoxy) phenyl] propane dianhydride, 2,2-bis (4-hydroxyphenyl) propane dibenzoate-3,3 ', 4,4'-tetracarboxylic dianhydride, 3 , 3 ', 4,4'-Diphenylsulfonetetracarboxylic dianhydride, 3,3', 4,4'-biphenyltetracarboxylic dianhydride, 2,3,3 ', 4-biphenyltetracarboxylic dianhydride Anhydrides or tetracarboxylic dianhydrides such as 5- (2,5-dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride and the like. . These may be used alone or in combination of two or more.

≪Poly (meth) acrylic resin≫
The poly (meth) acrylic resin is soluble in an organic solvent and contains a repeating unit obtained by copolymerizing at least one of (meth) acrylic acid and a (meth) acrylate derivative, Further, the weight average molecular weight is 1,000 or more and 1,000,000 or less in terms of polyethylene glycol. Here, (meth) acryl means at least one of methacryl and acryl.

  The poly (meth) acrylic resin is obtained by an arbitrary reaction. For example, at least one of (meth) acrylic acid and a (meth) acrylic acid ester derivative is prepared in a solvent in the presence of a radical polymerization initiator. By reacting with

  The (meth) acrylate derivative is not particularly limited. For example, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, tertiary butyl (meth) acrylate, hexyl (meth) acrylate, (meth) acryl 2-ethylhexyl acid, octyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, benzyl (meth) acrylate, and the like. Can be These may be used alone or in combination of two or more.

  Among these (meth) acrylate derivatives, methyl (meth) acrylate, ethyl (meth) acrylate, or butyl (meth) acrylate is considered to be the flexibility or chemical resistance of the insulating film of the photosensitive resin composition. It is preferable because it becomes a factor for improving the performance.

  Examples of the radical polymerization initiator include azo-based compounds such as azobisisobutyronitrile, azobis (2-methylbutyronitrile), and 2,2′-azobis-2,4-dimethylvaleronitrile; Organic peroxides such as butyl hydroperoxide, cumene hydroperoxide, benzoyl peroxide, dicumyl peroxide, di-t-butyl peroxide, potassium persulfate, sodium persulfate, persulfates such as ammonium persulfate, or And hydrogen peroxide, and these may be used alone or in combination of two or more.

  The amount of the radical polymerization initiator used is preferably from 0.001 to 5 parts by weight, more preferably from 0.01 to 1 part by weight, based on 100 parts by weight of the monomer used. . When the amount is less than 0.001 part by weight, the reaction becomes difficult to progress, while when the amount is more than 5 parts by weight, the molecular weight of the poly (meth) acrylic resin decreases, so that the viscosity of the photosensitive resin composition decreases. This is because it is difficult to form a high-quality insulating film in shape.

  The amount of the solvent used in the reaction for producing the poly (meth) acrylic resin is such that the solute weight concentration in the reaction solution, that is, the solution concentration is 5% by weight or more and 90% by weight or less. Preferably, the amount is preferably 20% by weight or more and 70% by weight or less. If the solution concentration is less than 5%, the polymerization reaction hardly occurs and the reaction rate is reduced, and the desired structural substance cannot be obtained. On the other hand, if the solution concentration is more than 90% by weight, the reaction solution becomes high in viscosity and the Is non-uniform.

  The reaction temperature is preferably from 20 ° C to 120 ° C, more preferably from 50 ° C to 100 ° C. This is because, when the temperature is lower than 20 ° C., the reaction time is too long, and when the temperature is higher than 120 ° C., gelation due to rapid progress of the reaction or three-dimensional crosslinking accompanying side reactions occurs. The reaction time may be appropriately selected depending on the scale of the batch or the reaction conditions employed.

<(B) Thermosetting resin>
The thermosetting resin is a compound containing at least one thermosetting organic group in a molecule. For example, epoxy resin, oxetane resin, phenolic resin, isocyanate resin, blocked isocyanate resin, bismaleimide resin, bisallylnadiimide resin, polyester resin (such as unsaturated polyester resin), diallyl phthalate resin, silicon resin, vinyl ester resin, Melamine resin, polybismaleimide triazine resin (BT resin), cyanate resin (such as cyanate ester resin), urea resin, guanamine resin, sulfamide resin, aniline resin, polyurea resin, thiourethane resin, polyazomethine resin, episulfide resin, ene resin -A thiol resin, a benzoxazine resin, a copolymer resin thereof, a modified resin obtained by modifying these resins, or a mixture of these resins or a mixture of these resins with other resins, It mentioned as curable resin.

  Among these, a polyfunctional epoxy resin is preferable for imparting heat resistance to an insulating film obtained by curing the photosensitive resin composition, and also for imparting adhesiveness to a conductor such as a metal foil or a circuit board. .

  A polyfunctional epoxy resin is a compound containing at least two epoxy groups in a molecule. For example, as the bisphenol A type epoxy resin, Japan Epoxy Resin Co., Ltd. product name jER828, jER1001, jER1002, Adeka Co., Ltd. product name Adeka Resin EP-4100E, Adeka Resin EP-4300E, Nippon Kayaku Co., Ltd. product RE-310S, RE-410S, DIC Corporation's Epicron 840S, Epicron 850S, Epicron 1050, Epicron 7050, Toto Kasei Corporation's Epototo YD-115, Epototo YD-127, Epototo YD-128 And the like.

  As bisphenol F type epoxy resin, trade names of jER806 and jER807 manufactured by Japan Epoxy Resin Co., Ltd., trade names of Adeka Resin EP-4901E, Adeka Resin EP-4930 and Adeka Resin EP-4950 manufactured by Adeka Corporation, manufactured by Nippon Kayaku Co., Ltd. Trade names RE-303S, RE-304S, RE-403S, RE-404S, trade names Epicron 830, Epicron 835 manufactured by DIC Corporation, trade names Epototo YDF-170, Epototo YDF-175S, Epototo manufactured by Toto Kasei Co., Ltd. YDF-2001 and the like.

  Examples of the bisphenol S-type epoxy resin include Epicron EXA-1514 (trade name, manufactured by DIC Corporation).

  Examples of hydrogenated bisphenol A type epoxy resins include jERYX8000, jERYX8034, and jERYL7170 (trade names, manufactured by Japan Epoxy Resin Co., Ltd.), Adeka Resin EP-4080E (trade name, manufactured by ADEKA Corporation), and Epicron EXA-7015 (trade name, manufactured by DIC Corporation) Chemical name: Epotote YD-3000, Epotote YD-4000D, etc., manufactured by Kasei Co., Ltd.

  Examples of the biphenyl type epoxy resin include jERYX4000, jERYL6121H, jERYL6640, and jERYL6677 manufactured by Japan Epoxy Resin Co., Ltd., and NC-3000 and NC-3000H manufactured by Nippon Kayaku Co., Ltd.

  Examples of the phenoxy type epoxy resin include jER1256, jER4250, jER4275, and the like, manufactured by Japan Epoxy Resin Co., Ltd.

  Examples of the naphthalene-type epoxy resin include Epicron HP-4032, Epicron HP-4700, and Epicron HP-4200 manufactured by DIC Corporation, and NC-7000L manufactured by Nippon Kayaku Co., Ltd.

  Examples of the phenol novolak type epoxy resin include jER152 and jER154 (trade names, manufactured by Japan Epoxy Resins Co., Ltd.), EPPN-201-L (trade name, manufactured by Nippon Kayaku Co., Ltd.), Epicron N-740 (trade name, manufactured by DIC Corporation) -770, trade name Epototh YDPN-638 manufactured by Toto Kasei Co., Ltd., and the like.

  As the cresol novolac type epoxy resin, Nippon Kayaku Co., Ltd. trade names EOCN-1020, EOCN-102S, EOCN-103S, EOCN-104S, DIC Corporation trade names Epicron N-660, Epicron N-670, Epicron N-680, Epicron N-695, and the like.

  Examples of the trisphenol methane type epoxy resin include trade names EPPN-501H, EPPN-501HY, and EPPN-502H manufactured by Nippon Kayaku Co., Ltd.

  Examples of the dicyclopentadiene type epoxy resin include XD-1000 (trade name, manufactured by Nippon Kayaku Co., Ltd.), and Epicron HP-7200 (trade name, manufactured by DIC Corporation).

  Examples of the amine-type epoxy resin include jER604 and jER630 (trade names, manufactured by Japan Epoxy Resins Co., Ltd.), Epototo YH-434, Epototo YH-434L (trade names, manufactured by Toto Kasei Co., Ltd., TETRAD-X, manufactured by Mitsubishi Gas Chemical Co., Ltd.) TERRAD-C and the like.

  Examples of the flexible epoxy resin include jER871, jER872, jERYL7175, and jERYL7217 (trade names, manufactured by Japan Epoxy Resin Co., Ltd.), and Epicron EXA-4850 (trade name, manufactured by DIC Corporation).

  Examples of the urethane-modified epoxy resin include Adeka Resin EPU-6, Adeka Resin EPU-73, and Adeka Resin EPU-78-11 manufactured by ADEKA Corporation.

  Examples of the rubber-modified epoxy resin include Adeka Resin EPR-4023, Adeka Resin EPR-4026, and Adeka Resin EPR-1309 manufactured by ADEKA Corporation.

  Examples of the chelate-modified epoxy resin include Adeka Resin EP-49-10 and Adeka Resin EP-49-20 manufactured by ADEKA Corporation.

  Examples of the heterocyclic-containing epoxy resin include TEPIC (trade name, manufactured by Nissan Chemical Industries, Ltd.).

  The (B) thermosetting resin is preferably blended so as to be 1 part by weight or more and 200 parts by weight or less based on 100 parts by weight of the binder polymer (A). This is because when the thermosetting resin is less than the lower limit of the above range, the required cured film properties are not satisfied, and when the thermosetting resin exceeds the upper limit of the above range, the cured film becomes brittle and hard. Therefore, when such a mixing ratio is used, the cured film characteristics of the photosensitive resin composition are appropriately exhibited.

  The curing agent for the thermosetting resin is not particularly limited. For example, phenol novolak resin, cresol novolak resin, phenol resin such as naphthalene-type phenol resin, amino resin, urea resin, melamine, dicyandiamide and the like can be mentioned. These may be used alone or in combination of two or more.

Further, the curing accelerator for the thermosetting resin is not particularly limited, for example, a phosphine-based compound such as triphenylphosphine,
Amine compounds such as tertiary amines, trimethanolamine, triethanolamine and tetraethanolamine;
Borate compounds such as 1,8-diaza-bicyclo [5,4,0] -7-undecenium tetraphenylborate,
Imidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-undecylimidazole, 1-benzyl-2-methylimidazole, 2-heptadecylimidazole, 2-isopropylimidazole, 2,4 Imidazoles such as -dimethylimidazole, 2-phenyl-4-methylimidazole,
Imidazolines such as 2-methylimidazoline, 2-ethylimidazoline, 2-isopropylimidazoline, 2-phenylimidazoline, 2-undecylimidazoline, 2,4-dimethylimidazoline and 2-phenyl-4-methylimidazoline;
2,4-diamino-6- [2′-methylimidazolyl- (1 ′)]-ethyl-s-triazine, 2,4-diamino-6- [2′-undecylimidazolyl- (1 ′)]-ethyl Azine-based imidazoles such as -s-triazine and 2,4-diamino-6- [2'-ethyl-4'-methylimidazolyl- (1 ')]-ethyl-s-triazine; These may be used alone or in combination of two or more.

<(C) radical polymerizable monomer>
The radically polymerizable monomer is a compound containing a radically polymerizable group in the molecule that causes the polymerization reaction to proceed by the photoradical polymerization initiator (D).

  The radical polymerizable monomer preferably has at least one unsaturated double bond in the molecule. Further, the unsaturated double bond is preferably a (meth) acryloyl group or a vinyl group.

  For example, bisphenol F EO modified (n = 2-50) diacrylate, bisphenol A EO modified (n = 2-50) diacrylate, bisphenol S EO modified (n = 2-50) diacrylate, bisphenol F EO modified (n = 2-50) dimethacrylate, bisphenol A EO modified (n = 2-50) dimethacrylate, bisphenol S EO modified (n = 2-50) dimethacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate , Ethylene glycol diacrylate, pentaerythritol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, dipentaerythritol hexaacrylate, tetramethylolpropane tetraacrylate , Tetraethylene glycol diacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, ethylene glycol dimethacrylate, pentaerythritol dimethacrylate, trimethylolpropane trimethacrylate, pentaerythritol trimethacrylate, dipentaerythritol hexamethacrylate, tetra Methylolpropane tetramethacrylate, tetraethylene glycol dimethacrylate, methoxydiethylene glycol methacrylate, methoxypolyethylene glycol methacrylate, β-methacryloyloxyethyl hydrogen phthalate, β-methacryloyloxyethyl hydrogen succinate, 3-chloro-2-hydroxypropyl methacrylate, Tearyl methacrylate, phenoxyethyl acrylate, phenoxydiethylene glycol acrylate, phenoxy polyethylene glycol acrylate, β-acryloyloxyethyl hydrogen succinate, lauryl acrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, polypropylene glycol dimethacrylate, 2-hydroxy-1,3-dimethacryloxypropane, 2,2-bis [4- (Methacryloxyethoxy) phenyl] propane, 2,2- Bis [4- (methacryloxydiethoxy) phenyl] propane, 2,2-bis [4- (methacryloxypolyethoxy) phenyl] propane, polyethylene glycol diacrylate, tripropylene glycol diacrylate, polypropylene glycol diacrylate, 2,2- Bis [4- (acryloxydiethoxy) phenyl] propane, 2,2-bis [4- (acryloxypolyethoxy) phenyl] propane, 2-hydroxy-1-acryloxy-3-methacryloxypropane, trimethylolpropane trimethacrylate, Tetramethylol methane triacrylate, tetramethylol methane tetraacrylate, methoxydipropylene glycol methacrylate, methoxytriethylene glycol acrylate, nonylph Nonoxy polyethylene glycol acrylate, nonylphenoxy polypropylene glycol acrylate, 1-acryloyloxypropyl-2-phthalate, isostearyl acrylate, polyoxyethylene alkyl ether acrylate, nonylphenoxyethylene glycol acrylate, polypropylene glycol dimethacrylate, 1,4-butanediol Dimethacrylate, 3-methyl-1,5-pentanediol dimethacrylate, 1,6-mexanediol dimethacrylate, 1,9-nonanediol methacrylate, 2,4-diethyl-1,5-pentanediol dimethacrylate, 1 , 4-cyclohexane dimethanol dimethacrylate, dipropylene glycol diacrylate, tricyclodecane dimethanol dimethyl Acrylate, 2,2-hydrogenated bis [4- (acryloxy-polyethoxy) phenyl] propane, 2,2-bis [4- (acryloxy-polypropoxy) phenyl] propane, 2,4-diethyl-1,5-pentane Diol diacrylate, ethoxylated thimethylolpropane triacrylate, propoxylated thimethylolpropane triacrylate, isocyanuric acid tri (ethane acrylate), pentathritol tetraacrylate, ethoxylated pentathritol tetraacrylate, propoxylated pentathritol tetraacrylate, Ditrimethylolpropane tetraacrylate, dipentaerythritol polyacrylate, triallyl isocyanurate, glycidyl methacrylate, glycidyl allyl ether, 1,3,5-tria Acryloylhexahydro-s-triazine, triallyl 1,3,5-benzenecarboxylate, triallylamine, triallyl citrate, triallyl phosphate, allobarbital, diallylamine, diallyldimethylsilane, diallyl disulfide, diallyl ether, zaryl sialylate , Diallyl phthalate, diallyl terephthalate, 1,3-diallyloxy-2-propanol, diallyl sulfide diallyl maleate, 4,4'-isopropylidene diphenol dimethacrylate, or 4,4'-isopropylidene diphenol diacrylate Is included. These may be used alone or in combination of two or more.

  When a repeating unit of EO (ethylene oxide) contained in one molecule of diacrylate or dimethacrylate is used in an amount of 2 mol or more and 50 mol or less, an alkali aqueous solution of a photosensitive resin composition is used. This is preferable because the solubility in an aqueous developer can be improved and the development time can be shortened.

<(D) Photo-radical polymerization initiator>
The photo-radical polymerization initiator is a compound that is activated by energy such as UV (ultraviolet light) and initiates and promotes a reaction of a radical-polymerizable group contained in a radical-polymerizable monomer.

  The photo-radical polymerization initiator is not particularly limited as long as it exhibits the above-mentioned functions, and examples thereof include, for example, Michler's ketone, 4,4′-bis (diethylamino) benzophenone, 4,4 ′, 4 ″ -tris (dimethylamino) Triphenylmethane, 2,2'-bis (2-chlorophenyl) -4,4 ', 5,5'-tetraphenyl-1,2'-diimidazole, acetophenone, benzoin, 2-methylbenzoin, benzoinmethyl- Ter, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2-t-butylanthraquinone, 1,2-benzo-9,10-anthraquinone, methylanthraquinone, thioxanthone, 2,4-diethylthioxanthone , 2-isopropylthioxanthone, 1-hydroxycyclohexylphenyl Ketone, diacetylbenzyl, benzyldimethylketal, benzyldiethylketal, 2 (2'-furylethylidene) -4,6-bis (trichloromethyl) -S-triazine, 2 [2 '(5 "-methyl Furyl) ethylidene] -4,6-bis (trichloromethyl) -S-triazine, 2 (p-methoxyphenyl) -4,6-bis (trichloromethyl) -S-triazine, 2,6-di (p-azidobenzal ) -4-Methylcyclohexanone, 4,4'-diazidochalcone, di (tetraalkylammonium) -4,4'-diazidostilbene-2,2'-disulfonate, 2,2-dimethoxy-1,2 -Diphenylethan-1-one, 1-hydroxy-cyclohexyl-phenyl-ketone, 2-hydroxy-2-methyl-1-phenyl-pro 1-one, 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propan-1-one, 2-methyl-1- [4- (methylthio) phenyl ] -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butane-1, bis (2,4,6-trimethylbenzoyl) -phenylphosphine Oxide, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethyl-pentylphosphine oxide, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, 2-hydroxy-2-methyl-1- Phenyl-propane-1-ketone, bis (n5-2,4-cyclopentadien-1-yl) -bis (2,6-difluoro-3- (1H Pyrrol-1-yl) -phenyl) titanium, 1,2-octanedione, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)], iodonium, (4-methylphenyl) [4 -(2-methylpropyl) phenyl] -hexafluorophosphate (1-), ethyl-4-dimethylaminobenzoate, 2-ethylhexyl-4-dimethylaminobenzoate, ethanone, 1- [9-ethyl-6- (2 -Methylbenzoyl) -9H-carbazol-3-yl]-, 1- (O-acetyloxime) and the like. These may be used alone or in combination of two or more.

  The (D) radical photopolymerization initiator is blended in an amount of 0.1 to 20 parts by weight based on 100 parts by weight of the total of (A) the binder polymer and (C) the radically polymerizable monomer. Is preferred. Because, when the photo-radical polymerization initiator is less than the lower limit of the above range, the reaction of the radical polymerizable group at the time of light irradiation hardly occurs, and the curing becomes insufficient. This is because it becomes difficult to adjust the amount, resulting in an overexposure state. Therefore, with such a mixing ratio, the photosensitivity of the photosensitive resin composition is improved, that is, the photocuring reaction proceeds efficiently.

<(E) Light-emitting material>
The light-emitting material is, for example, a fluorescent material or a light storage material, and is a compound that becomes excited by absorbing ultraviolet light and emits light when returning to a ground state. And such a light emitting material gives the emitted light (energy) to the (D) radical photopolymerization initiator.

  The absorption spectrum of a general photoradical polymerization initiator has a maximum wavelength of about 600 nm. Therefore, when the emission spectrum of the light emitting material is 600 nm or less, the light energy of the light emitting material is absorbed by the photo radical polymerization initiator, and the reaction proceeds. Therefore, the emission spectrum of the light-emitting material is preferably 300 nm or more and 600 nm or less, and the excitation spectrum required for such light emission is preferably 200 nm or more and 400 nm or less.

  The luminescent material is preferably blended so as to be 0.1 to 10 parts by weight based on 100 parts by weight of the binder polymer (A). The reason is that when the light-emitting material is less than the lower limit of the above range, the reaction of the radical polymerizable group during light irradiation hardly occurs and curing is insufficient, while when the light-emitting material exceeds the upper limit of the above range, the amount of light irradiation is adjusted. Is difficult, and an over-exposure state occurs. Therefore, with such a mixing ratio, the photosensitivity of the photosensitive resin composition is improved, that is, the photocuring reaction proceeds efficiently.

≪Fluorescent material≫
The fluorescent material among the light emitting materials is a compound that returns from the excited state to the ground state as it is.

  For example, 9,10-diarylanthracene derivatives, pyrene, coronene, rubrene, 1,1,4,4-tetraphenylbutadiene, tris (8-quinolate) aluminum complex, tris (4-methyl-8-quinolate) aluminum complex, Bis (8-quinolate) zinc complex, tris (4-methyl-5-trifluoromethyl-8-quinolate) aluminum complex, tris (4-methyl-5-cyano-8-quinolate) aluminum complex, bis (2-methyl -5-trifluoromethyl-8-quinolinolate) [4- (4-cyanophenyl) phenolate] aluminum complex, bis (2-methyl-5-cyano-8-quinolinolate) [4- (4-cyanophenyl) phenolate] Aluminum complex, tris (8-quinolinolate) scandium complex Bis [8- (para-tosyl) aminoquinoline] zinc complex and cadmium complex, 1,2,3,4-tetraphenylcyclopentadiene, or coumarin, perylene, pyran, anthrone, porphyrene, quinacridone And N, N'-dialkyl-substituted quinacridone-based, naphthalimide-based, N, N'-diaryl-substituted pyrrolopyrrole-based, and iridium complex-based low-molecular light-emitting materials.

光 Phosphorescent material≫
A light-storing material among the light-emitting materials is a compound which returns from an excited state to a ground state via a triplet state having a slightly lower energy level.

For example, zinc sulfide based (ZnS: Cu), strontium aluminate based (SrAl2O4), or calcium aluminate (CaAl ₂ O ₄₎ may be mentioned. Among them, zinc sulfide or aluminate exhibiting long persistence is preferable.

<Other components>
Various additives such as an adhesion aid, an antifoaming agent, a leveling agent, a polymerization inhibitor, and a flame retardant may be added to the photosensitive resin composition.

  Examples of the antifoaming agent include an acrylic compound, a vinyl compound, and a butadiene compound.

  Examples of the leveling agent include an acrylic compound or a vinyl compound.

  Examples of the adhesion assistant (also referred to as an adhesion-imparting agent) include a silane coupling agent, a triazole-based compound, a tetrazole-based compound, and a triazine-based compound.

  Examples of the polymerization inhibitor include hydroquinone and hydroquinone monomethyl ether.

  Examples of the flame retardant include a phosphoric ester compound, a halogen-containing compound, a metal hydroxide, an organic phosphorus compound, and a silicone compound. Such flame retardants are used, for example, as additive flame retardants or reactive flame retardants. The flame retardants may be used alone or in combination of two or more. As the flame retardant, among these, it is preferable to use a non-halogen compound from the viewpoint of prevention of environmental pollution, and particularly preferable is a metal hydroxide or a phosphorus flame retardant.

<Use of photosensitive resin composition>
Hereinafter, the photosensitive resin composition containing the components (A) to (E) and other components will be described as an example.

≪Pulverization and dispersion≫
The photosensitive resin composition is obtained by pulverizing and dispersing the components (A) to (E) and other components and mixing them. The pulverizing / dispersing method is not particularly limited, but a general kneading device such as a bead mill, a ball mill, or a three-roll mill may be used.

  In addition, the particle diameter of the particles contained in the photosensitive resin composition is measured by a method using a gauge specified in JIS K 5600-2-5. In addition, if a particle size distribution measuring device is used, the average particle size, the particle size, or the particle size distribution can be measured.

  Then, by directly using the photosensitive resin composition or using the prepared photosensitive resin composition solution, an insulating film or a relief pattern for a printed circuit board is obtained as follows.

≪Coating and drying≫
First, a photosensitive resin composition or a photosensitive resin composition solution is applied to a printed circuit board and dried to remove an organic solvent [film forming step]. In this case, the application to the printed circuit board is performed by, for example, screen printing, curtain roll, reverse roll, spray coating, or spin coating using a spinner.

  The thickness of the formed coating film is preferably 5 μm or more and 100 μm or less, more preferably 10 μm or more and 100 μm or less. Then, such a coating film is dried at a temperature of 120 ° C. or less, preferably 40 ° C. or more and 100 ° C. or less.

≪Exposure and development≫
Next, a negative-type photomask is placed on the dried coating film, and exposure is performed using active light such as ultraviolet light, visible light, or an electron beam. Thereafter, the unexposed portion is washed out with a developing solution using various methods such as shower, paddle, immersion, or ultrasonic wave to obtain a relief pattern. Then, the formed relief pattern is rinsed to remove unnecessary residues. Examples of the rinsing liquid include water and an acidic aqueous solution.

  Since the time until a pattern is formed varies depending on the spray pressure or flow rate of the developing device and the temperature of the etching solution, it is preferable to find appropriate device conditions as appropriate.

  Further, it is preferable to use an aqueous alkali solution as the developer. This developer may contain a water-soluble organic solvent such as methanol, ethanol, n-propanol, isopropanol, or N-methyl-2-pyrrolidone.

  Examples of the alkaline compound that imparts alkalinity to the aqueous solution include hydroxides or carbonates of alkali metals, alkaline earth metals or ammonium ions, hydrogencarbonates, and amine compounds.

  Specifically, sodium hydroxide, potassium hydroxide, ammonium hydroxide, sodium carbonate, potassium carbonate, ammonium carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, ammonium hydrogen carbonate, tetramethyl ammonium hydroxide, tetraethyl ammonium hydroxide, tetra Propylammonium hydroxide, tetraisopropylammonium hydroxide, N-methyldiethanolamine, N-ethyldiethanolamine, N, N-dimethylethanolamine, triethanolamine, triisopropanolamine, triisopropylamine, etc. No. Of course, compounds other than these may be used as long as the aqueous solution exhibits alkalinity.

  The concentration of the alkaline compound used in the step of developing the photosensitive resin composition is preferably 0.01% by weight or more and 20% by weight or less, more preferably 0.02% by weight or more and 10% by weight or less. Further, the temperature of the developer depends on the composition of the photosensitive resin composition or the composition of the alkali developer, and is generally preferably from 0 ° C. to 80 ° C., more preferably from 10 ° C. to 60 ° C. It is more preferable to have them.

≪Heating≫
Next, a heat treatment is performed on the obtained relief pattern. By performing a heat treatment to react the reactive groups remaining in the molecular structure, an insulating film having high heat resistance can be obtained [curing step].

  The final curing temperature in this heating is preferably low so as to prevent oxidation of the circuit and the like and to prevent the adhesion between the circuit and the substrate of the printed circuit board from being reduced. For example, the temperature is preferably from 100 ° C. to 250 ° C., more preferably from 120 ° C. to 200 ° C., and even more preferably from 130 ° C. to 180 ° C. This is because if the final heating temperature is in such a temperature range, the temperature is relatively low, so that the oxidative deterioration of the circuit can be suppressed.

絶 縁 Insulation film for circuit board≫
As described above, when the thickness of the insulating film for a circuit board obtained from the photosensitive resin composition is 2 μm or more and 50 μm or less, the resolution is at least up to 10 μm, particularly 10 μm or more, by patterning using a photolithography method or the like. It is preferable because it exhibits a resolving power of 1000 μm or less.

  Further, such an insulating film having a high resolution is suitable, for example, as an insulating material for a flexible printed circuit board. In addition, it is also used as a photo-curing type protective agent for various circuit coatings, a photosensitive heat-resistant adhesive, or a wire / cable insulating coating.

  Further, in the above description, a photosensitive resin containing (B) a thermosetting resin in addition to (A) a binder polymer, (C) a radical polymerizable monomer, (D) a photoradical polymerization initiator, and (E) a luminescent material. Although an insulating film formed by directly applying a conductive resin composition to a printed circuit board has been described as an example, the present invention is not limited to this.

  For example, an insulating film is formed using a photosensitive resin composition, or a resin film obtained by applying and drying a photosensitive resin composition solution on a smooth surface of a material to be coated, not on a printed circuit board. May be. Note that such an insulating film secures circuit insulation by being attached to a printed circuit board.

  Further, such a method of manufacturing an insulating film for a circuit board includes a film forming step and a curing step, although the photosensitive resin composition is applied not to a printed circuit board but to a material to be applied. That is, the method includes a film forming step of applying the photosensitive resin composition to the substrate and then drying the applied resin, and a curing step of curing the formed resin film.

  In addition, the excitation spectrum of the light-emitting material (E) is not less than 200 nm and not more than 400 nm and the emission spectrum is not limited to such an insulating film or an insulating film formed by directly applying to a printed circuit board. Is preferably 300 nm or more and 600 nm or less.

  And as such (E) light emitting material, a fluorescent material and a luminous material are mentioned. In the case of a phosphorescent material, for example, zinc sulfide or aluminate may be used.

  In addition, (B) a thermosetting resin is excluded or another resin is contained, (A) a binder polymer, (C) a radical polymerizable monomer, (D) a photoradical polymerization initiator, and (E) a light emitting material. , The photosensitive resin composition becomes an insulating film for a circuit board that allows light for exposure such as photolithography to sufficiently reach inside.

  The present invention is also applicable to a printed circuit board with an insulating film in which the above-described insulating film for a circuit board is coated on a printed circuit board.

  Hereinafter, the present invention will be described specifically with reference to examples, but the present invention is not limited to these examples.

[(A) Preparation of binder polymer]
The following five types (A-1 to A-5) were prepared as binder polymers.

[● A-1] Binder polymer In a reaction vessel equipped with a stirrer, thermometer, dropping funnel, and nitrogen introduction tube, methyltriglyme (= 1,2-bis (2-methoxyethoxy) ethane) as a polymerization solvent. 100.0 g was charged and heated to 80 ° C. while stirring under a nitrogen stream.

  To this, 12.0 g (0.14 mol) of methacrylic acid, 28.0 g (0.16 mol) of benzyl methacrylate, 60.0 g (0.42 mol) of butyl methacrylate, which had been previously mixed at room temperature, 0.5 g of azobisisobutyronitrile as a radical polymerization initiator was dropped from the dropping funnel over 3 hours while keeping the temperature at 80 ° C. After the completion of the dropwise addition, the temperature of the reaction solution was raised to 90 ° C. while stirring, and the reaction was further stirred for 2 hours while keeping the temperature of the reaction solution at 90 ° C. for reaction.

  By the above reaction, a binder polymer (A-1), which is an acrylic resin solution containing a carboxyl group in the molecule, was obtained. The solid content of the obtained resin solution was 50%, the weight average molecular weight was 48,000, and the acid value of the solid content was 78 mgKOH / g.

  The solid content concentration, weight average molecular weight, and acid value of the binder polymer (A-1) and the binder polymers (A-2) to (A-5) described below were measured by the following methods.

(Solid content concentration)
The measurement was performed according to JIS K5601-1-2. Note that the drying condition was selected to be 170 ° C. × 1 hour.

(Weight average molecular weight)
The measurement was performed under the following conditions.
Apparatus used: Tosoh HLC-8220GPC equivalent column: Tosoh TSK gel Super AWM-H (6.0 mm ID × 15 cm) x 2 guard columns: Tosoh TSK guard column Super AW-H
Eluent: 30 mM LiBr + 20 mM H3PO4 in DMF
Flow rate: 0.6 mL / min
Column temperature: 40 ° C
Detection conditions: RI: polarity (+), response (0.5 sec)
Sample concentration: about 5mg / mL
Standard: PEG (polyethylene glycol).

(Acid value)
The measurement was performed according to JIS K5601-2-1.

[● A-2] Binder polymer 30.00 g of methyltriglyme (= 1,2-bis (2-methoxyethoxy) ethane) as a polymerization solvent was placed in a reaction vessel equipped with a stirrer, a thermometer, and a nitrogen inlet tube. After charging 10.31 g (0.050 mol) of norbornene diisocyanate, the mixture was heated to 80 ° C. and dissolved while stirring under a nitrogen stream.

  To this solution, 50.00 g (0.025 mol) of polycarbonate diol (PCDL T5652, product name, manufactured by Asahi Kasei Corporation, weight average molecular weight: 2000), and 6.51 g (0.050 mol) of 2-hydroxyethyl methacrylate were added to methyltriol. A solution dissolved in 30.00 g of glyme was added over 1 hour. Thereafter, this solution was heated and stirred at 80 ° C. for 5 hours to cause a reaction.

  By the above reaction, a binder polymer (A-2) which was a resin solution containing a urethane bond and a methacryloyl group in a molecule was obtained. The solid content of the obtained resin solution was 53%, and the weight average molecular weight was 5,200.

[● A-3] Binder polymer 30.00 g of methyltriglyme (= 1,2-bis (2-methoxyethoxy) ethane) as a solvent for polymerization was placed in a reaction vessel equipped with a stirrer, a thermometer, and a nitrogen inlet tube. After charging 10.31 g (0.050 mol) of norbornene diisocyanate, the mixture was heated to 80 ° C. and dissolved while stirring under a nitrogen stream.

  To this solution, 50.00 g (0.025 mol) of polycarbonate diol (PCDL T5652, product name, manufactured by Asahi Kasei Corporation, weight average molecular weight 2000), and 3.70 g of 2,2-bis (hydroxymethyl) butanoic acid (0. (025 mol) in 30.00 g of methyltriglyme was added over 1 hour. Thereafter, this solution was heated and stirred at 80 ° C. for 5 hours to cause a reaction.

  By the above reaction, a binder polymer (A-3) which was a resin solution containing a urethane bond and a carboxyl group in the molecule was obtained. The solid content of the obtained resin solution was 52%, the weight average molecular weight was 5,600, and the acid value of the solid was 22 mgKOH / g.

[● A-4] Binder polymer 40.00 g of methyltriglyme (= 1,2-bis (2-methoxyethoxy) ethane) as a polymerization solvent was placed in a reaction vessel equipped with a stirrer, a thermometer, and a nitrogen inlet tube. After charging 20.62 g (0.100 mol) of norbornene diisocyanate, the mixture was heated to 80 ° C. while stirring under a nitrogen stream to dissolve.

  To this solution, 50.00 g (0.025 mol) of polycarbonate diol (PCDL T5652, product name, manufactured by Asahi Kasei Corporation, weight average molecular weight: 2000), 3.70 g of 2,2-bis (hydroxymethyl) butanoic acid (0.025 mol) Mol) and 13.02 g (0.100 mol) of 2-hydroxyethyl methacrylate dissolved in 40.00 g of methyltriglyme were added over 1 hour. Thereafter, this solution was heated and stirred at 80 ° C. for 5 hours to cause a reaction.

  By the above reaction, a binder polymer (A-4) which was a resin solution containing a urethane bond, a carboxyl group, and a (meth) acryloyl group in a molecule was obtained. The solid content of the obtained resin solution was 52%, the weight average molecular weight was 8,600, and the acid value of the solid content was 18 mgKOH / g.

[● A-5] Binder polymer 35.00 g of methyltriglyme (= 1,2-bis (2-methoxyethoxy) ethane) as a solvent for polymerization was placed in a reaction vessel equipped with a stirrer, a thermometer, and a nitrogen inlet tube. After charging 10.31 g (0.050 mol) of norbornene diisocyanate, the mixture was heated to 80 ° C. and dissolved while stirring under a nitrogen stream.

  To this solution, a solution prepared by dissolving 50.00 g (0.025 mol) of polycarbonate diol (PCDL T5652, product name, manufactured by Asahi Kasei Corporation, weight average molecular weight: 2,000) in 35.00 g of methyltriglyme was added over 1 hour. I let it. Thereafter, the solution was heated and stirred at 80 ° C. for 2 hours to cause a reaction.

  After the completion of the reaction, 15.51 g (0.050 mol) of 3,3 ', 4,4'-oxydiphthalic dianhydride (hereinafter referred to as ODPA) was added to the above reaction solution. After the addition, the mixture was heated to 190 ° C. and reacted for 1 hour. Thereafter, the solution was cooled to 80 ° C., and 3.60 g (0.200 mol) of pure water was added. Then, after the addition, the temperature was raised to 110 ° C., and the mixture was heated and refluxed for 5 hours.

  By the above reaction, a binder polymer (A-5) which was a resin solution containing a urethane bond, a carboxyl group, and an imide group in the molecule was obtained. The solid content of the obtained resin solution was 53%, the weight average molecular weight was 9,200, and the acid value of the solid content was 86 mgKOH / g.

[◆ Adjustment of Examples 1 to 8 and Comparative Examples 1 and 2]
(A-1) to (A-5) described above, (A) a binder polymer, (B) a thermosetting resin, (C) a radically polymerizable monomer, (D) a photoradical polymerization initiator, and (E) a luminescent material. , And other components were added to prepare photosensitive resin compositions (Examples 1 to 8 and Comparative Examples 1 and 2).

  Table 1 shows the specific compounding amount of the constituent raw materials in the resin solid content and the types of the raw materials in each example. In addition, 1,2-bis (2-methoxyethoxy) ethane which is the organic solvent in the table is the total amount of the solvent including the solvent contained in the resin solution (binder polymer) synthesized above. Further, the blending amounts in Table 1 are shown in parts by weight.

(Remarks in Table 1)
<1>
Nissan Chemical Co., Ltd. Product name of polyfunctional epoxy resin (triglycidyl isocyanurate) <2>
Hitachi Chemical Co., Ltd. Product name of EO-modified bisphenol A dimethacrylate <3>
BASF Japan Ltd. product name of oxime ester photopolymerization initiator <4>
Nemoto Special Chemical Co., Ltd. Product name of SrAl ₂ O ₄ phosphorescent material <5>
Nemoto Special Chemical Co., Ltd. Product name of CaAl ₂ O ₄ based phosphorescent material <6>
BASF Co., Ltd. Product name of blue colorant Pigment Blue 15: 4
<7>
Kyoeisha Chemical Co., Ltd.… Product name of butadiene antifoam

[■ Evaluation]
The above-described photosensitive resin composition was first mixed by a general stirrer equipped with a stirring blade, and then passed twice with a three-roll mill to obtain a uniform solution. And when these particle diameters were measured with a grind meter, all were 10 micrometers or less. After completely defoaming the photosensitive resin composition as a mixed solution using a defoaming device, the following evaluation was performed using the photosensitive resin composition. The evaluation results are shown in Table 1.

[(I) Evaluation of photosensitivity]
The above-mentioned photosensitive resin composition is cast and applied to a 25 μm polyimide film (manufactured by Kaneka Corporation: trade name: 25NPI) in an area of 100 mm × 100 mm using a baker-type applicator, and dried at 80 ° C. for 20 minutes. Then, a film having a final dry thickness of 25 μm and a film having a thickness of 50 μm were prepared.

Then, this film was exposed to ultraviolet rays with an integrated exposure amount of 300 mJ / cm ² using a negative photomask having a line width / space width of 100 μm / 100 μm.

After this exposure, spray development was performed for 60 seconds at a discharge pressure of 1.0 kgf / mm ² using a solution obtained by heating a 1.0% by weight aqueous solution of sodium carbonate to 30 ° C. After the development, the substrate was sufficiently washed with pure water, and then heated and cured in an oven at 150 ° C. for 60 minutes to form an insulating film of a photosensitive resin composition on a polyimide film.

Then, the surface of the insulating film was observed according to the following criteria, and the evaluation of ／/ × was performed.
〇: A photosensitive pattern having a line width / space width = 100/100 μm without remarkable line thickening or development residue on the surface of the polyimide film.
×: No photosensitive pattern having a line width / space width = 100/100 μm was drawn on the polyimide film surface.

[(Ii) Evaluation of warpage]
The above-mentioned photosensitive resin composition is cast and applied to a 25 μm polyimide film (manufactured by Kaneka Corporation: trade name: 25NPI) in an area of 100 mm × 100 mm using a baker-type applicator, and dried at 80 ° C. for 20 minutes. Then, a film having a final dry thickness of 25 μm was produced. Then, the film was exposed by irradiating ultraviolet rays with an integrated exposure amount of 300 mJ / cm ² .

After this exposure, spray development was performed for 60 seconds at a discharge pressure of 1.0 kgf / mm ² using a solution obtained by heating a 1.0% by weight aqueous solution of sodium carbonate to 30 ° C. After the development, the substrate was sufficiently washed with pure water, and then heated and cured in an oven at 150 ° C. for 60 minutes to form an insulating film of a photosensitive resin composition on a polyimide film.

  Then, the polyimide film in which the heat-cured photosensitive resin composition is laminated is cut into a film having an area of 50 mm × 50 mm, and as shown in FIG. The cut-out film 11 was placed so as to face, and the height (length) of the warpage of the end of the film 11 was measured.

  The smaller the amount of warpage of the coating film on the surface of the polyimide film, the smaller the stress on the surface of a circuit board such as a flexible printed circuit board, and the lower the amount of warpage of the circuit board. The amount of warpage is preferably 5 mm or less.

[(Iii) Evaluation of electrical insulation reliability]
First, line width / space width = 100 μm / 100 μm on a flexible copper-clad laminate (thickness of electrolytic copper foil: 12 μm, polyimide film: Apical 25NPI manufactured by Kaneka Corporation, copper foil bonded to polyimide adhesive) Was immersed in a 10% by volume aqueous sulfuric acid solution for 1 minute, washed with pure water, and surface treated with copper foil.

Then, the above-described photosensitive resin composition is cast and applied over the entire surface of the patterned copper foil in this flexible copper-clad laminate, and dried at 80 ° C. for 20 minutes to produce a film having a final dry thickness of 20 μm. did. Then, the film was exposed by irradiating ultraviolet rays with an integrated exposure amount of 300 mJ / cm ² .

After this exposure, spray development was performed for 60 seconds at a discharge pressure of 1.0 kgf / mm ² using a solution obtained by heating a 1.0% by weight aqueous solution of sodium carbonate to 30 ° C. After the development, the substrate was sufficiently washed with pure water, and then heated and cured in an oven at 150 ° C. for 60 minutes to form an insulating film of a photosensitive resin composition on the flexible copper-clad laminate.

  Then, in an environmental tester at 85 ° C. and 85% RH, a direct current of 100 V was applied to both terminal portions of the test piece, and changes in insulation resistance value, occurrence of migration, and the like were observed.

Then, the surface of the insulating film was observed according to the following criteria, and the evaluation of ／/ × was performed.
：: A resistance value of 10 8 or more at 1000 hours after the start of the test, with no occurrence of migration or dendrite.
C: Migration or dendrite or the like occurred 1000 hours after the start of the test.

11 Cutting film 15 Smooth table

Claims (6)

at least,
(A) a binder polymer,
(C) a radical polymerizable monomer,
(D) a photo-radical polymerization initiator,
(E) a luminescent material,
Wherein the (E) light-emitting material is a photosensitive resin composition that is a light- storing material .   2. The insulating film for a circuit board according to claim 1, wherein the excitation spectrum of the light-emitting material (E) is 200 nm or more and 400 nm or less, and the emission spectrum is 300 nm or more and 600 nm or less. 3. The insulating film for a circuit board according to claim 1, wherein the phosphorescent material is zinc sulfide or aluminate. The insulating film for a circuit board according to any one of claims 1 to 3 , further comprising (B) a thermosetting resin. Claim 1 or the circuit board insulating film according to item 1, the insulating film with the printed circuit board is coated on the printed circuit board 4. A method for producing a circuit board insulating film formed of the photosensitive resin composition according to any one of claims 1 to 4 ,
A film-forming step of drying after applying the photosensitive resin composition to a substrate,
A method of manufacturing an insulating film for a circuit board, comprising: a curing step of curing a formed resin film.

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