JP2012246367A - Thermosetting resin composition, cured product thereof, semiconductor sealing material, prepreg, circuit board and buildup film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermosetting resin composition having excellent heat resistance while securing a low dielectric constant and a low dielectric dissipation factor when it is cured, a cured product of the same, and a semiconductor sealing material, a prepreg, a circuit board and a buildup film which exert such performances.SOLUTION: The thermosetting resin composition includes an epoxy resin and an epoxy resin curing agent. As the epoxy resin curing agent, an active ester resin (A1) having a structure obtained by reacting a phenolic resin (a-1) having a molecular structure in which phenols are coupled through an alicyclic hydrocarbon group, an aromatic dicarboxylic acid or a halide thereof (a-2), and an aromatic monohydroxy compound (a-3), and a polyfunctional phenolic compound (A2) having a structure in which an unsaturated aliphatic compound and a phenolic compound are polyadded are used in combination.

Description

  The present invention relates to a thermosetting resin composition that exhibits excellent flame retardancy, heat resistance, low dielectric loss tangent in the cured product, and has excellent performance in solvent solubility, the cured product, and a semiconductor sealing material , Prepreg, circuit board, and build-up film.

Epoxy resin compositions containing an epoxy resin and a curing agent as an essential component exhibit excellent heat resistance and insulation in the cured product, and are widely used in electronic component applications such as semiconductors and multilayer printed boards. .
Among these electronic component applications, in the technical field of multilayer printed circuit board insulating materials, in recent years, signal speed and frequency have been increasing in various electronic devices. However, with the increase in signal speed and frequency, it is becoming difficult to obtain a low dielectric loss tangent while maintaining a sufficiently low dielectric constant.

  Therefore, it is possible to provide a thermosetting resin composition capable of obtaining a cured body that exhibits a sufficiently low dielectric loss tangent while maintaining a sufficiently low dielectric constant even with respect to a signal that is increased in speed and frequency. It is desired. As materials capable of realizing these low dielectric constants and low dielectric loss tangents, an active ester compound obtained by reacting dicyclopentadiene type phenolic resin with benzoyl chloride and bis (chlorocarbonyl) benzene is used as a curing agent for epoxy resin. A technique is known (see Patent Document 1 below).

  However, due to the trend toward higher frequency and smaller size in electronic parts, multilayer printed circuit board insulating materials are also required to have extremely high heat resistance, and the activity obtained by aryl esterifying the phenolic hydroxyl group in the phenol novolac resin described above In the ester compound, the crosslink density of the cured product is lowered due to the introduction of the aryl ester structure, and the heat resistance of the cured product is insufficient. Thus, it was difficult to achieve both heat resistance and low dielectric constant / low dielectric loss tangent.

JP 2004-169021 A

  Therefore, the problem to be solved by the present invention is that the cured product has a low dielectric constant and a low dielectric loss tangent, and also has a thermosetting resin composition that combines excellent heat resistance, the cured product, and the performance thereof. Another object is to provide a semiconductor sealing material, a prepreg, a circuit board, and a build-up film.

  As a result of intensive studies to solve the above problems, the inventors of the present invention have, as an epoxy resin curing agent, an active ester resin having a specific structure having both an alicyclic skeleton and an aromatic ring, an unsaturated alicyclic compound, and To use the polyfunctional phenol compound having a polyaddition reaction structure with a phenol compound as a curing agent for an epoxy resin, the heat resistance in the cured product is dramatically improved, and the present invention is completed. It came.

  That is, the present invention is a thermosetting resin composition comprising an epoxy resin and an epoxy resin curing agent as essential components, wherein the epoxy resin curing agent is an aliphatic cyclic hydrocarbon group. A phenol resin (a-1) having a molecular structure in which a phenol compound is knotted through the aromatic dicarboxylic acid or its halide (a-2), and an aromatic monohydroxy compound (a-3). The thermosetting property characterized by using together the active ester resin (A1) which has the structure obtained, and the polyfunctional phenolic compound (A2) which has a structure which polyaddition-reacted the unsaturated alicyclic compound and the phenol compound. The present invention relates to a resin composition.

The present invention further relates to a cured product obtained by curing the thermosetting resin composition.
In addition to the epoxy resin and the epoxy resin curing agent in the thermosetting resin composition, the present invention further includes an inorganic filler in a proportion of 70 to 95% by mass in the composition. The present invention relates to a semiconductor sealing material comprising a composition.

The present invention further relates to a prepreg obtained by impregnating a reinforcing substrate with a solution obtained by diluting the thermosetting resin composition in an organic solvent and semi-curing the resulting impregnated substrate.
The present invention further relates to a circuit board obtained by obtaining a varnish obtained by diluting the thermosetting resin composition in an organic solvent, and heating and press-molding a varnish shaped into a plate shape and a copper foil.
The present invention further relates to a build-up film obtained by applying a solution obtained by diluting the thermosetting resin composition in an organic solvent onto a base film and drying it.

  According to the present invention, the cured product has a low dielectric constant and a low dielectric loss tangent, and also has a thermosetting resin composition having excellent heat resistance, the cured product, and a semiconductor sealing material having these performances. A prepreg, a circuit board, and a build-up film can be provided.

Hereinafter, the present invention will be described in detail.
The active ester resin (A1) used as a curing agent for epoxy resin in the thermosetting resin composition of the present invention is a phenol resin (a-1) having a molecular structure in which a phenol compound is knotted via an aliphatic cyclic hydrocarbon group. ), An aromatic dicarboxylic acid or its halide (a-2), and an aromatic monohydroxy compound (a-3).

In the present invention, the active ester resin (A1) is preferably the aromatic dicarboxylic acid or its halide (a-) because the cured product has a low dielectric loss tangent and a sufficiently low viscosity when dissolved in an organic solvent. 2) With respect to 1 mol of the carboxyl group or acid halide group in
0.05 to 0.75 mol of phenolic hydroxyl group in the phenol resin (a-1),
The aromatic monohydroxy compound (a-3) preferably has a structure obtained by reacting at a ratio of 0.25 to 0.95 mol.

  In this invention, adjusting the raw material ratio which comprises active ester resin (A1) to the said range, specifically, the said phenol resin with respect to the functional group number of the said aromatic carboxylic acid or its halide (a-2). A cured product of an active ester compound obtained by adjusting the number of functional groups in (a-1) to be small and increasing the amount (number of moles) of the aromatic monohydroxy compound (a-3) used. Can significantly reduce the dielectric loss tangent.

  Here, in the phenol resin (a-1), the molecular structure in which a phenol compound is knotted via an aliphatic cyclic hydrocarbon group is an unsaturated aliphatic cyclic hydrocarbon containing two double bonds in one molecule. Examples include a structure obtained by polyaddition reaction of a compound and a phenol compound. Here, examples of the phenol compound include phenol and substituted phenol compounds in which one or more alkyl groups, alkenyl groups, allyl groups, aryl groups, aralkyl groups, or halogen groups are substituted. Specific examples include cresol, xylenol, ethylphenol, isopropylphenol, butylphenol, octylphenol, nonylphenol, vinylphenol, isopropenylphenol, allylphenol, phenylphenol, benzylphenol, chlorophenol, bromophenol, naphthol, and dihydroxynaphthalene. However, it is not limited to these. Moreover, you may use these mixtures. Among these, phenol is particularly preferable from the viewpoint of excellent fluidity and curability.

  Specific examples of unsaturated alicyclic hydrocarbon compounds include dicyclopentadiene, tetrahydroindene, 4-vinylcyclohexene, 5-vinylnorborna-2-ene, α-pinene, β-pinene, and limonene. Can be mentioned. Among these, dicyclopentadiene is preferred from the viewpoint of property balance, particularly heat resistance and hygroscopicity. In addition, since dicyclopentadiene is contained in petroleum fractions, industrial dicyclopentadiene may contain other aliphatic or aromatic dienes as impurities, but heat resistance, curability, In consideration of moldability and the like, a product having a purity of 90% by mass or more of dicyclopentadiene is desirable.

  Next, the aromatic dicarboxylic acid or its halide (a-2) is an aromatic dicarboxylic acid such as isophthalic acid, terephthalic acid, 1,4-, 2,3-, or 2,6-naphthalenedicarboxylic acid, and These acid halides include acid fluorides, acid chlorides, acid bromides, acid iodides and the like. Among these, an acid chloride of an aromatic dicarboxylic acid is preferable from the viewpoint of good reactivity, and isophthalic acid dichloride and terephthalic acid dichloride are particularly preferable, and isophthalic acid dichloride is particularly preferable.

  Next, as the aromatic monohydroxy compound (a-3), for example, phenol; alkylphenol compounds such as o-cresol, m-cresol, p-cresol, 3,5-xylenol; o-phenylphenol, p-phenyl Aralkylphenol compounds such as phenol, 2-benzylphenol, 4-benzylphenol, 4- (α-cumyl) phenol; and naphthol compounds such as α-naphthol and β-naphthol. Among these, α-naphthol and β-naphthol are preferable from the viewpoint of lowering the dielectric loss tangent of the cured product.

The active ester resin (A1) described above is a structure obtained by reacting a phenol resin (a-1), an aromatic dicarboxylic acid or its halide (a-2), and an aromatic monohydroxy compound (a-3). In particular, the following structural formula (1)
The following structural formula (1)

（式中、Ｘはベンゼン環、ナフタレン環、炭素原子数１〜４のアルキル基で核置換されたベンゼン環又はナフタレン環、ビフェニル基、Ｙはベンゼン環、ナフタレン環、炭素原子数１〜４のアルキル基で核置換されたベンゼン環又はナフタレン環であり、ｋは０又は１を表し、ｎは繰り返し単位の平均で０．２５〜１．５である。）
で表されるものが、低誘電率・低誘電正接といった誘電特性に優れる点から好ましい。

(In the formula, X is a benzene ring, naphthalene ring, benzene ring or naphthalene ring substituted with an alkyl group having 1 to 4 carbon atoms, a biphenyl group, Y is a benzene ring, naphthalene ring, or 1 to 4 carbon atoms. (It is a benzene ring or a naphthalene ring nucleus-substituted with an alkyl group, k represents 0 or 1, and n is an average of repeating units of 0.25 to 1.5.)
Is preferable from the viewpoint of excellent dielectric properties such as low dielectric constant and low dielectric loss tangent.

  Specific examples of the active ester resin (A1) include compounds represented by the following structural formulas (1-1) to (1-9).

  In the present invention, among these, in particular, the following structural formula (2)

（式中、Ｘはベンゼン環又はナフタレン環であり、ｋは０又は１を表し、ｎは繰り返し単位の平均値で０．０５〜２．５である。）
で表される構造のものがとりわけ硬化物の誘電正接が低く、かつ、有機溶剤に溶解させた際の溶液粘度が低くなる点から好ましい。
なお、特に、上記構造式（１）又は（２）においてｎの値、即ち、繰り返し単位の平均値は０．２５〜１．５の範囲にあるものが、溶液粘度が低くビルドアップ用接着フィルムへの製造が容易となる点から好ましい。また、上記構造式（１）又は（２）中、ｋの値は０であることが、本発明の効果が顕著なものとなる点から好ましい。

(In the formula, X represents a benzene ring or a naphthalene ring, k represents 0 or 1, and n represents an average value of repeating units of 0.05 to 2.5.)
In particular, the structure represented by the formula is preferred because the cured product has a low dielectric loss tangent and a low solution viscosity when dissolved in an organic solvent.
In particular, the value of n in the above structural formula (1) or (2), that is, the average value of the repeating units is in the range of 0.25 to 1.5, the solution viscosity is low and the adhesive film for buildup This is preferable from the viewpoint of easy production. Further, in the structural formula (1) or (2), it is preferable that the value of k is 0 from the point that the effect of the present invention becomes remarkable.

Here, n in the structural formula (1) or (2) can be obtained as follows.
[How to Obtain n in Structural Formula (1) or (2)]
According to GPC measurement performed under the following conditions, styrene equivalent molecular weights (α1, α2, α3, α4) corresponding to n = 1, n = 2, n = 3, and n = 4, and n = 1 and n = The ratios (β1 / α1, β2 / α2, β3 / α3, β4 / α4) to the respective theoretical molecular weights (β1, β2, β3, β4) of 2, n = 3, and n = 4 were determined, and these (β1 / The average value of α1 to β4 / α4) is obtained. A value obtained by multiplying the number average molecular weight (Mn) obtained by GPC by this average value is defined as an average molecular weight. Next, the value of n is calculated using the molecular weight of the structural formula a as the average molecular weight.

(GPC measurement conditions)
Measuring device: “HLC-8220 GPC” manufactured by Tosoh Corporation
Column: Guard column “H _XL -L” manufactured by Tosoh Corporation
+ "TSK-GEL G2000HXL" manufactured by Tosoh Corporation
+ "TSK-GEL G2000HXL" manufactured by Tosoh Corporation
+ Tosoh Corporation “TSK-GEL G3000HXL”
+ Tosoh Corporation “TSK-GEL G4000HXL”
Detector: RI (Differential refraction diameter)
Data processing: “GPC-8020 Model II version 4.10” manufactured by Tosoh Corporation
Measurement conditions: Column temperature 40 ° C
Developing solvent Tetrahydrofuran
Flow rate: 1.0 ml / min Standard: The following monodisperse polystyrene having a known molecular weight was used in accordance with the measurement manual of “GPC-8020 Model II version 4.10”.
(Polystyrene used)
“A-500” manufactured by Tosoh Corporation
"A-1000" manufactured by Tosoh Corporation
"A-2500" manufactured by Tosoh Corporation
"A-5000" manufactured by Tosoh Corporation
“F-1” manufactured by Tosoh Corporation
"F-2" manufactured by Tosoh Corporation
“F-4” manufactured by Tosoh Corporation
“F-10” manufactured by Tosoh Corporation
“F-20” manufactured by Tosoh Corporation
“F-40” manufactured by Tosoh Corporation
“F-80” manufactured by Tosoh Corporation
“F-128” manufactured by Tosoh Corporation
Sample: A 1.0 mass% tetrahydrofuran solution filtered in terms of resin solids and filtered through a microfilter (50 μl).

  It can be produced by reacting a phenol resin (a-1), an aromatic dicarboxylic acid or its halide (a-2), and an aromatic monohydroxy compound (a-3).

Specifically, the method in which the phenol resin (a-1), the aromatic dicarboxylic acid or its halide (a-2), and the aromatic monohydroxy compound (a-3) are reacted with each other is alkalinized. The reaction can be carried out in the presence of a catalyst.
Examples of the alkali catalyst that can be used here include sodium hydroxide, potassium hydroxide, triethylamine, and pyridine. Of these, sodium hydroxide and potassium hydroxide are particularly preferred because they can be used in the form of an aqueous solution and the productivity is good.

  Specifically, the reaction is performed by mixing a phenol resin (a-1), an aromatic dicarboxylic acid or its halide (a-2), and an aromatic monohydroxy compound (a-3) in the presence of an organic solvent. And a method of reacting the alkali catalyst or an aqueous solution thereof while dropping continuously or intermittently. At that time, the concentration of the aqueous solution of the alkali catalyst is preferably in the range of 3.0 to 30%. Examples of the organic solvent that can be used here include toluene and dichloromethane.

  After completion of the reaction, if an aqueous solution of an alkali catalyst is used, the reaction solution is allowed to stand for separation, the aqueous layer is removed, and the remaining organic layer is repeated until the aqueous layer after washing becomes almost neutral, The target active ester resin (A1) can be obtained. The active ester resin (A1) thus obtained is preferably one having a softening point in the range of 100 to 180 ° C., particularly from the viewpoint of excellent heat resistance of the cured product.

On the other hand, in the polyfunctional phenol compound (A2) having a structure in which the unsaturated alicyclic compound and the phenol compound used in the present invention are polyaddition-reacted, the phenol compound is knotted through the aliphatic cyclic hydrocarbon group described above. This corresponds to the phenol resin (a-1) having a molecular structure.
Examples of the phenol compound used here include substituted phenol compounds to which phenol and an alkyl group, alkenyl group, allyl group, aryl group, aralkyl group, halogen group, or the like are bonded. Specifically, cresol, xylenol, ethylphenol, isopropylphenol, butylphenol, octylphenol, nonylphenol, vinylphenol, isopropenylphenol, allylphenol, phenylphenol, benzylphenol, chlorophenol, bromophenol (respectively o, m, p) -Including isomers), bisphenol A, naphthol, dihydroxynaphthalene and the like, but are not limited thereto. Moreover, you may use these mixtures. Among these, phenol and cresol are particularly preferable from the viewpoint of excellent fluidity and curability.

  Further, the unsaturated alicyclic compound is not particularly limited as long as it is an aliphatic cyclic hydrocarbon compound having two or more unsaturated double bonds in one molecule, but examples include dicyclopentadiene, tetrahydroindene. 4-vinylcyclohexene, 5-vinylnorborna-2-ene, α-pinene, β-pinene, limonene and the like. Among these, dicyclopentadiene is preferred from the viewpoint of property balance, particularly heat resistance and hygroscopicity. In addition, since dicyclopentadiene is contained in petroleum fractions, industrial dicyclopentadiene may contain other aliphatic or aromatic dienes as impurities, but heat resistance, curability, In consideration of moldability and the like, it is desirable to use a product having a purity of 90% by mass or more of dicyclopentadiene.

Here, a method of polyaddition reaction of the unsaturated alicyclic compound and the phenol compound is, for example, an unsaturated alicyclic compound and a phenol compound, phenol compound / unsaturated alicyclic compound = 2. A polyaddition catalyst is added to a phenol compound that has been used within a range of 5/1 to 15/1 (molar ratio) and made into a melt or solution. There is a method in which an addition reaction is allowed to proceed, and then an unreacted phenol compound is recovered by distillation to obtain a polyaddition reaction product. Examples of the polyaddition catalyst include inorganic acids such as hydrochloric acid and sulfuric acid, organic acids such as p-toluenesulfonic acid, and Lewis acids such as AlCl ₃ and BF ₃ . When the unreacted phenol compound is recovered by distillation, the target polyfunctional phenol compound (A2) can be obtained by appropriately adjusting the recovery temperature and the degree of vacuum.

  The polyfunctional phenol compound (A2) thus obtained preferably has a softening point in the range of 85 to 145 ° C. from the viewpoint that the effect of improving heat resistance is good.

  In the present invention, as described above, the active ester resin (A1) and the polyfunctional phenol compound (A2) are used in combination as a curing agent for an epoxy resin. Here, the blending ratio [(A1) / (A2)] of the active ester resin (A1) and the polyfunctional phenol compound (A2) is a ratio of 30/70 to 70/30 on a mass basis. Is preferable from the viewpoint of excellent heat resistance and dielectric properties in the cured product.

  Moreover, when using together the said active ester resin (A1) and the said polyfunctional phenolic compound (A2), specifically, these are previously mixed beforehand in presence of an organic solvent before mix | blending with an epoxy resin. It is preferable.

  Organic solvents used here include ketone solvents such as acetone, methyl ethyl ketone, cyclohexanone, etc., acetates such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate, carbitol acetate, and carbitols such as cellosolve, butyl carbitol. Aromatic hydrocarbon solvents such as Tolu, Toluene, Xylene, etc., dimethylformamide, dimethylacetamide, N-methylpyrrolidone, etc. are mentioned, especially when used as varnish for laminates and adhesive films for buildup. It is preferable to adjust the solution viscosity to be 300 to 10,000 mPa · S (25 ° C.) when an active ester resin of 65% toluene solution is used.

Next, the epoxy resin used in the thermosetting resin composition of the present invention is, for example, a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a biphenyl type epoxy resin, a tetramethylbiphenyl type epoxy resin, a phenol novolac type epoxy resin, Cresol novolac type epoxy resin, triphenylmethane type epoxy resin, tetraphenylethane type epoxy resin, dicyclopentadiene-phenol addition reaction type epoxy resin, phenol aralkyl type epoxy resin, naphthol novolak type epoxy resin, naphthol aralkyl type epoxy resin, naphthol -Phenol co-condensed novolac type epoxy resin, naphthol-cresol co-condensed novolac type epoxy resin, aromatic hydrocarbon formaldehyde resin modified phenolic resin type epoxy resin , Biphenyl-modified novolak type epoxy resins. Among these epoxy resins, tetramethylbiphenol type epoxy resin, biphenyl aralkyl type epoxy resin, in particular, since a cured product having excellent flame retardancy can be obtained.
It is preferable to use a novolac type epoxy resin.

  The compounding ratio of the epoxy resin curing agent and the epoxy resin in the thermosetting resin composition of the present invention is such that the compounding ratio of the epoxy resin, the active ester resin (A1), and the polyfunctional phenol compound (A2) is as follows. The molar ratio [epoxy group in the epoxy resin / (carbonyloxy group in the active ester resin (A1) + phenolic hydroxyl group in the polyfunctional phenol compound (A2)] is 0.8 / 1.2-1. 2 / 0.8, and the mass ratio [(A1) / (A2)] is a ratio of 30/70 to 70/30 on a mass basis; This is preferable from the viewpoint of excellent dielectric properties.

The thermosetting resin composition of the present invention may be used in combination with the epoxy resin curing agent in addition to the epoxy resin curing agent and the epoxy resin. As the curing agent for epoxy resin that can be used here, for example, curing agents such as amine compounds, amide compounds, acid anhydride compounds, phenol compounds, and the like can be used. Specifically, examples of the amine compound include diaminodiphenylmethane, diethylenetriamine, triethylenetetramine, diaminodiphenylsulfone, isophoronediamine, imidazole, BF ₃ -amine complex, and guanidine derivative. Examples of the amide compound include dicyandiamide. And polyamide resins synthesized from dimer of linolenic acid and ethylenediamine. Examples of acid anhydride compounds include phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, maleic anhydride, and tetrahydrophthalic anhydride. Acid, methyltetrahydrophthalic anhydride, methyl nadic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, etc., and phenolic compounds include phenol novolac resin, cresol novolac resin Aromatic hydrocarbon formaldehyde resin modified phenol resin, dicyclopentadiene phenol addition type resin, phenol aralkyl resin, naphthol aralkyl resin, trimethylol methane resin, tetraphenylol ethane resin, naphthol novolak resin, naphthol-phenol co-condensed novolak resin, naphthol -Cresol-condensed novolak resin, biphenyl-modified phenolic resin (polyhydric phenol compound in which phenol nucleus is linked by bismethylene group), biphenyl-modified naphthol resin (polyvalent naphthol compound in which phenol nucleus is linked by bismethylene group), aminotriazine modified Examples thereof include polyhydric phenol compounds such as phenol resins (polyhydric phenol compounds in which phenol nuclei are linked with melamine or benzoguanamine).

  Among these, those containing a large amount of an aromatic skeleton in the molecular structure are preferable from the viewpoint of flame retardancy, and specifically, phenol novolac resins, cresol novolac resins, aromatic hydrocarbon formaldehyde resin-modified phenol resins, phenol aralkyls. Resins, naphthol aralkyl resins, naphthol novolak resins, naphthol-phenol co-condensed novolak resins, naphthol-cresol co-condensed novolak resins, biphenyl-modified phenol resins, biphenyl-modified naphthol resins, and aminotriazine-modified phenol resins are preferred because of their excellent flame retardancy. .

  When using the above epoxy resin curing agent in combination, the amount used is preferably in the range of 10 to 50% from the viewpoint of dielectric properties.

  Moreover, a hardening accelerator can also be used together suitably with the thermosetting resin composition of this invention as needed. Various curing accelerators can be used, and examples thereof include phosphorus compounds, tertiary amines, imidazoles, organic acid metal salts, Lewis acids, and amine complex salts. In particular, when used as a build-up material application or a circuit board application, dimethylaminopyridine and imidazole are preferable from the viewpoint of excellent heat resistance, dielectric characteristics, solder resistance, and the like. In particular, when used as a semiconductor encapsulating material, it is excellent in curability, heat resistance, electrical characteristics, moisture resistance reliability, etc., so that triphenylphosphine is used for phosphorus compounds and 1,8-diazabicyclo is used for tertiary amines. -[5.4.0] -undecene (DBU) is preferred.

  As described above, the thermosetting resin composition of the present invention described in detail above is characterized by exhibiting excellent solvent solubility. Therefore, the thermosetting resin composition preferably contains an organic solvent in addition to the above components. Examples of the organic solvent that can be used here include methyl ethyl ketone, acetone, dimethylformamide, methyl isobutyl ketone, methoxypropanol, cyclohexanone, methyl cellosolve, ethyl diglycol acetate, propylene glycol monomethyl ether acetate, etc. The amount used can be appropriately selected depending on the application. For example, in printed wiring board applications, it is preferable to use a polar solvent having a boiling point of 160 ° C. or lower, such as methyl ethyl ketone, acetone, 1-methoxy-2-propanol, etc. It is preferable to use in the ratio which becomes 40-80 mass%. On the other hand, for use in an adhesive film for buildup, examples of the organic solvent (C) include ketone solvents such as acetone, methyl ethyl ketone, cyclohexanone, ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate, carbitol acetate, and the like. It is preferable to use acetate solvents, carbitol solvents such as cellosolve and butyl carbitol, aromatic hydrocarbon solvents such as toluene and xylene, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, etc. It is preferable to use it in the ratio which becomes 30-60 mass%.

  The thermosetting resin composition is a non-halogen flame retardant that substantially does not contain a halogen atom in order to exert flame retardancy, for example, in the field of printed wiring boards, as long as the reliability is not lowered. May be blended.

  Examples of the non-halogen flame retardants include phosphorus flame retardants, nitrogen flame retardants, silicone flame retardants, inorganic flame retardants, and organic metal salt flame retardants. The flame retardants may be used alone or in combination, and a plurality of flame retardants of the same system may be used, or different types of flame retardants may be used in combination.

  As the phosphorus flame retardant, either inorganic or organic can be used. Examples of the inorganic compound include inorganic nitrogen-containing phosphorus compounds such as red phosphorus, monoammonium phosphate, diammonium phosphate, triammonium phosphate, ammonium phosphate such as ammonium polyphosphate, and phosphate amide.

  The red phosphorus is preferably subjected to a surface treatment for the purpose of preventing hydrolysis and the like. Examples of the surface treatment method include (i) magnesium hydroxide, aluminum hydroxide, zinc hydroxide, water A method of coating with an inorganic compound such as titanium oxide, bismuth oxide, bismuth hydroxide, bismuth nitrate or a mixture thereof; (ii) an inorganic compound such as magnesium hydroxide, aluminum hydroxide, zinc hydroxide, titanium hydroxide; and A method of coating with a mixture of a thermosetting resin such as a phenol resin, (iii) thermosetting of a phenol resin or the like on a coating of an inorganic compound such as magnesium hydroxide, aluminum hydroxide, zinc hydroxide, or titanium hydroxide For example, a method of double coating with a resin may be used.

  Examples of the organic phosphorus compound include, for example, general-purpose organic phosphorus compounds such as phosphate ester compounds, phosphonic acid compounds, phosphinic acid compounds, phosphine oxide compounds, phosphorane compounds, organic nitrogen-containing phosphorus compounds, and 9,10- Dihydro-9-oxa-10-phosphaphenanthrene = 10-oxide, 10- (2,5-dihydrooxyphenyl) -10H-9-oxa-10-phosphaphenanthrene = 10-oxide, 10- (2,7 -Dihydrooxynaphthyl) -10H-9-oxa-10-phosphaphenanthrene = 10-oxide and other cyclic organic phosphorus compounds and derivatives obtained by reacting them with compounds such as epoxy resins and phenol resins.

  The blending amount thereof is appropriately selected depending on the type of the phosphorus-based flame retardant, the other components of the thermosetting resin composition, and the desired degree of flame retardancy, for example, a curing agent for epoxy resins, When using red phosphorus as a non-halogen flame retardant in 100 parts by mass of a thermosetting resin composition containing all of epoxy resin, non-halogen flame retardant, and other fillers and additives, 0.1 to 2 It is preferable to mix | blend in the range of 0.0 mass part, and when using an organophosphorus compound, it is similarly preferable to mix | blend in the range of 0.1-10.0 mass part, and 0.5-6.0 mass is especially preferable. It is preferable to blend in the range of parts.

  In addition, when using the phosphorous flame retardant, the phosphorous flame retardant may be used in combination with hydrotalcite, magnesium hydroxide, boric compound, zirconium oxide, black dye, calcium carbonate, zeolite, zinc molybdate, activated carbon, etc. Good.

  Examples of the nitrogen-based flame retardant include triazine compounds, cyanuric acid compounds, isocyanuric acid compounds, phenothiazines, and the like, and triazine compounds, cyanuric acid compounds, and isocyanuric acid compounds are preferable.

  Examples of the triazine compound include melamine, acetoguanamine, benzoguanamine, melon, melam, succinoguanamine, ethylene dimelamine, melamine polyphosphate, triguanamine, and the like, for example, guanylmelamine sulfate, melem sulfate, melam sulfate, etc. Examples thereof include an aminotriazine sulfate compound, aminotriazine-modified phenol resin, and aminotriazine-modified phenol resin further modified with tung oil, isomerized linseed oil, and the like.

  Specific examples of the cyanuric acid compound include cyanuric acid and cyanuric acid melamine.

  The compounding amount of the nitrogen-based flame retardant is appropriately selected depending on the type of the nitrogen-based flame retardant, the other components of the thermosetting resin composition, and the desired degree of flame retardancy. Compounded in the range of 0.05 to 10 parts by mass in 100 parts by mass of thermosetting resin composition containing all curing agents, epoxy resins, curing agents, non-halogen flame retardants and other fillers and additives It is preferable to mix | blend in the range of 0.1-5 mass parts especially.

  Moreover, when using the said nitrogen-type flame retardant, you may use together a metal hydroxide, a molybdenum compound, etc.

  The silicone flame retardant is not particularly limited as long as it is an organic compound containing a silicon atom, and examples thereof include silicone oil, silicone rubber, and silicone resin.

  The amount of the silicone-based flame retardant is appropriately selected according to the type of the silicone-based flame retardant, the other components of the thermosetting resin composition, and the desired degree of flame retardancy. May be blended in the range of 0.05 to 20 parts by mass in 100 parts by mass of the thermosetting resin composition containing all of the curing agent, epoxy resin, non-halogen flame retardant and other fillers and additives. preferable. Moreover, when using the said silicone type flame retardant, you may use a molybdenum compound, an alumina, etc. together.

  Examples of the inorganic flame retardant include metal hydroxide, metal oxide, metal carbonate compound, metal powder, boron compound, and low melting point glass.

  Specific examples of the metal hydroxide include aluminum hydroxide, magnesium hydroxide, dolomite, hydrotalcite, calcium hydroxide, barium hydroxide, zirconium hydroxide and the like.

  Specific examples of the metal oxide include, for example, zinc molybdate, molybdenum trioxide, zinc stannate, tin oxide, aluminum oxide, iron oxide, titanium oxide, manganese oxide, zirconium oxide, zinc oxide, molybdenum oxide, and cobalt oxide. Bismuth oxide, chromium oxide, nickel oxide, copper oxide, tungsten oxide and the like.

  Specific examples of the metal carbonate compound include zinc carbonate, magnesium carbonate, calcium carbonate, barium carbonate, basic magnesium carbonate, aluminum carbonate, iron carbonate, cobalt carbonate, and titanium carbonate.

  Specific examples of the metal powder include aluminum, iron, titanium, manganese, zinc, molybdenum, cobalt, bismuth, chromium, nickel, copper, tungsten, and tin.

  Specific examples of the boron compound include zinc borate, zinc metaborate, barium metaborate, boric acid, and borax.

Specific examples of the low-melting-point glass include, for example, Ceeley (Bokusui Brown), hydrated glass SiO ₂ —MgO—H ₂ O, PbO—B ₂ O ₃ system, ZnO—P ₂ O ₅ —MgO system, P ₂ O ₅ —B ₂ O ₃ —PbO—MgO, P—Sn—O—F, PbO—V ₂ O ₅ —TeO ₂ , Al ₂ O ₃ —H ₂ O, lead borosilicate, etc. The glassy compound can be mentioned.

  The blending amount of the inorganic flame retardant is appropriately selected depending on the kind of the inorganic flame retardant, the other components of the thermosetting resin composition, and the desired degree of flame retardancy. May be blended in the range of 0.05 to 20 parts by mass in 100 parts by mass of the thermosetting resin composition containing all of the curing agent, epoxy resin, non-halogen flame retardant and other fillers and additives. It is particularly preferable to blend in the range of 0.5 to 15 parts by mass.

  Examples of the organic metal salt flame retardant include ferrocene, acetylacetonate metal complex, organic metal carbonyl compound, organic cobalt salt compound, organic sulfonic acid metal salt, metal atom and aromatic compound or heterocyclic compound or an ionic bond or Examples thereof include a coordinated compound.

  The amount of the organometallic salt-based flame retardant is appropriately selected depending on the type of organometallic salt-based flame retardant, the other components of the thermosetting resin composition, and the desired degree of flame retardancy. For example, in the range of 0.005 to 10 parts by mass in 100 parts by mass of the thermosetting resin composition containing all of the curing agent for epoxy resin, epoxy resin, non-halogen flame retardant and other fillers and additives. It is preferable to mix.

  An inorganic filler can be mix | blended with the thermosetting resin composition of this invention as needed. Examples of the inorganic filler include fused silica, crystalline silica, alumina, silicon nitride, and aluminum hydroxide. When particularly increasing the blending amount of the inorganic filler, it is preferable to use fused silica. The fused silica can be used in either a crushed shape or a spherical shape. However, in order to increase the blending amount of the fused silica and suppress an increase in the melt viscosity of the molding material, it is preferable to mainly use a spherical shape. In order to further increase the blending amount of the spherical silica, it is preferable to appropriately adjust the particle size distribution of the spherical silica. The filling rate is preferably higher in consideration of flame retardancy, and particularly preferably 20% by mass or more with respect to the total amount of the thermosetting resin composition. Moreover, when using for uses, such as an electrically conductive paste, electroconductive fillers, such as silver powder and copper powder, can be used.

  The thermosetting resin composition of this invention can add various compounding agents, such as a silane coupling agent, a mold release agent, a pigment, an emulsifier, as needed.

  The thermosetting resin composition of the present invention can be obtained by uniformly mixing the above-described components. The thermosetting resin composition of the present invention containing the curing agent for epoxy resin of the present invention, an epoxy resin, and further a curing accelerator if necessary can be easily made into a cured product by a method similar to a conventionally known method. Can do. Examples of the cured product include molded cured products such as laminates, cast products, adhesive layers, coating films, and films.

  Applications for which the thermosetting resin composition of the present invention is used include hard printed wiring board materials, resin compositions for flexible wiring boards, insulating materials for circuit boards such as interlayer insulating materials for build-up boards, semiconductor sealing materials , Conductive paste, adhesive film for build-up, resin casting material, adhesive and the like. Among these various applications, in hard printed wiring board materials, insulating materials for electronic circuit boards, and adhesive film for build-up, passive parts such as capacitors and active parts such as IC chips are embedded in so-called electronic parts. It can be used as an insulating material for a substrate. Among these, circuit boards such as hard printed wiring board materials, resin compositions for flexible wiring boards, and interlayer insulation materials for build-up boards because of their high flame resistance, high heat resistance, low thermal expansibility, and solvent solubility. It is preferable to use it for a material and a semiconductor sealing material.

  Here, the circuit board of the present invention is manufactured by obtaining a varnish obtained by diluting a thermosetting resin composition in an organic solvent, laminating it into a plate shape, laminating it with a copper foil, and heating and pressing it. Is. Specifically, for example, to manufacture a hard printed circuit board, a varnish-like thermosetting resin composition containing the organic solvent is further blended with an organic solvent to form a varnish, and this is impregnated into a reinforcing base material. There is a method of obtaining the prepreg of the present invention produced by semi-curing and stacking a copper foil on the prepreg and heat-pressing it. Examples of the reinforcing substrate that can be used here include paper, glass cloth, glass nonwoven fabric, aramid paper, aramid cloth, glass mat, and glass roving cloth. The method will be described in more detail. First, the above varnish-like thermosetting resin composition is cured by heating at a heating temperature corresponding to the solvent type used, preferably 50 to 170 ° C. Get a prepreg. At this time, the mass ratio of the thermosetting resin composition to be used and the reinforcing substrate is not particularly limited, but it is usually preferable that the resin content in the prepreg is 20 to 60% by mass. Next, the prepreg obtained as described above is laminated by a conventional method, and a copper foil is appropriately stacked, and then subjected to thermocompression bonding at a pressure of 1 to 10 MPa at 170 to 250 ° C. for 10 minutes to 3 hours, A target circuit board can be obtained.

  In order to produce a flexible wiring board from the thermosetting resin composition of the present invention, a curing agent for epoxy resin and an epoxy resin, and an organic solvent are blended, and using a coating machine such as a reverse roll coater or a comma coater, Apply to electrically insulating film. Subsequently, it heats at 60-170 degreeC for 1 to 15 minutes using a heating machine, volatilizes a solvent, and B-stages an adhesive composition. Next, the metal foil is thermocompression bonded to the adhesive using a heating roll or the like. At that time, the pressure is preferably 2 to 200 N / cm and the pressure is preferably 40 to 200 ° C. If sufficient adhesive performance can be obtained, the process may be completed here. However, when complete curing is required, it is preferably post-cured at 100 to 200 ° C. for 1 to 24 hours. The thickness of the adhesive composition film after finally curing is preferably in the range of 5 to 100 μm.

  As a method for obtaining an interlayer insulating material for a buildup substrate from the thermosetting resin composition of the present invention, for example, the thermosetting resin composition appropriately blended with rubber, filler or the like is sprayed on a wiring board on which a circuit is formed. After applying using a coating method, a curtain coating method or the like, it is cured. Then, after drilling a predetermined through-hole part etc. as needed, it treats with a roughening agent, forms the unevenness | corrugation by washing the surface with hot water, and metal-treats, such as copper. As the plating method, electroless plating or electrolytic plating treatment is preferable, and examples of the roughening agent include an oxidizing agent, an alkali, and an organic solvent. Such operations are sequentially repeated as desired, and a build-up base can be obtained by alternately building up and forming the resin insulating layer and the conductor layer having a predetermined circuit pattern. However, the through-hole portion is formed after the outermost resin insulating layer is formed. In addition, a resin-coated copper foil obtained by semi-curing the resin composition on the copper foil is thermocompression-bonded at 170 to 250 ° C. on a circuit board on which a circuit is formed, thereby forming a roughened surface and plating treatment. It is also possible to produce a build-up substrate by omitting the process.

  Next, in order to produce a semiconductor sealing material from the thermosetting resin composition of the present invention, a curing agent for epoxy resin, an epoxy resin, and a compounding agent such as an inorganic filler may be added to an extruder, Examples thereof include a method of sufficiently melting and mixing until uniform using a roller, a roll or the like. At that time, silica is usually used as the inorganic filler. In that case, the semiconductor encapsulant of the present invention is blended in the thermosetting resin composition by blending the inorganic filler in a proportion of 70 to 95% by mass. It becomes a stopping material. For semiconductor package molding, the composition is molded by casting, using a transfer molding machine, an injection molding machine or the like, and further heated at 50 to 200 ° C. for 2 to 10 hours to form a semiconductor device which is a molded product. The method of obtaining is mentioned.

  The method for producing an adhesive film for buildup from the thermosetting resin composition of the present invention is, for example, a multilayer print by applying the thermosetting resin composition of the present invention on a support film to form a resin composition layer. The method of setting it as the adhesive film for wiring boards is mentioned.

  When the thermosetting resin composition of the present invention is used for an adhesive film for build-up, the adhesive film is softened under a lamination temperature condition (usually 70 ° C. to 140 ° C.) in a vacuum laminating method, and simultaneously with the circuit board lamination. It is important to exhibit fluidity (resin flow) capable of filling the via hole or through hole in the circuit board, and it is preferable to blend the above-described components so as to exhibit such characteristics.

  Here, the diameter of the through hole of the multilayer printed wiring board is usually 0.1 to 0.5 mm, and the depth is usually 0.1 to 1.2 mm. It is usually preferable to allow resin filling in this range. When laminating both surfaces of the circuit board, it is desirable to fill about 1/2 of the through hole.

  Specifically, the method for producing the above-mentioned adhesive film is prepared by preparing the varnish-like thermosetting resin composition of the present invention, applying the varnish-like composition to the surface of the support film, and further heating. Alternatively, it can be produced by drying the organic solvent by hot air blowing or the like to form the layer (α) of the thermosetting resin composition.

  The thickness of the formed layer (α) is usually not less than the thickness of the conductor layer. Since the thickness of the conductor layer of the circuit board is usually in the range of 5 to 70 μm, the thickness of the resin composition layer is preferably 10 to 100 μm.

  In addition, the said layer ((alpha)) may be protected with the protective film mentioned later. By protecting with a protective film, it is possible to prevent dust and the like from being attached to the surface of the resin composition layer and scratches.

  The above-mentioned support film and protective film are made of polyolefin such as polyethylene, polypropylene and polyvinyl chloride, polyethylene terephthalate (hereinafter sometimes abbreviated as “PET”), polyester such as polyethylene naphthalate, polycarbonate, polyimide, and further. Examples thereof include metal foil such as pattern paper, copper foil, and aluminum foil. In addition, the support film and the protective film may be subjected to a release treatment in addition to the mud treatment and the corona treatment.

  Although the thickness of a support film is not specifically limited, Usually, it is 10-150 micrometers, Preferably it is used in 25-50 micrometers. Moreover, it is preferable that the thickness of a protective film shall be 1-40 micrometers.

  The above support film is peeled off after being laminated on a circuit board or after forming an insulating layer by heat curing. If the support film is peeled after the adhesive film is heat-cured, adhesion of dust and the like in the curing process can be prevented. In the case of peeling after curing, the support film is usually subjected to a release treatment in advance.

  Next, the method for producing a multilayer printed wiring board using the adhesive film obtained as described above is, for example, when the layer (α) is protected with a protective film, Lamination is performed on one or both sides of the circuit board by, for example, vacuum laminating so that α) is in direct contact with the circuit board. The laminating method may be a batch method or a continuous method using a roll. Further, the adhesive film and the circuit board may be heated (preheated) as necessary before lamination.

The laminating conditions are preferably a pressure bonding temperature (laminating temperature) of 70 to 140 ° C., a pressure bonding pressure of preferably 1 to 11 kgf / cm ² (9.8 × 10 ^{4 to} 107.9 × 10 ⁴ N / m 2), Lamination is preferably performed under reduced pressure with an air pressure of 20 mmHg (26.7 hPa) or less.

  When using the thermosetting resin composition of the present invention as a conductive paste, for example, a method of dispersing fine conductive particles in the thermosetting resin composition to form a composition for an anisotropic conductive film, room temperature And a liquid paste resin composition for circuit connection and an anisotropic conductive adhesive.

  Moreover, the thermosetting resin composition of the present invention can be further used as a resist ink. In this case, a vinyl monomer having an ethylenically unsaturated double bond and a cationic polymerization catalyst as a curing agent are blended into the thermosetting resin composition, and a pigment, talc, and filler are further added for resist ink. After making it into a composition, after apply | coating on a printed circuit board by a screen printing system, the method of setting it as a resist ink hardened | cured material is mentioned.

  As a method for obtaining the cured product of the present invention, for example, the composition obtained by the above method may be heated in a temperature range of about 20 to 250 ° C.

  Therefore, according to the present invention, it is possible to obtain a thermosetting resin composition that exhibits high flame retardancy and excellent environmental properties without using a halogen-based flame retardant. In addition, the excellent dielectric properties of these cured products can realize high-speed operation speed of high-frequency devices. In addition, the phenolic hydroxyl group-containing resin can be easily and efficiently produced by the production method of the present invention, and a molecular design corresponding to the target level of performance described above becomes possible.

Next, the present invention will be specifically described with reference to Examples and Comparative Examples. In the following, “parts” and “%” are based on mass unless otherwise specified. In addition, the melt viscosity and softening point measurement in 150 degreeC, GPC measurement, < ¹³ > C-NMR, and FD-MS spectrum were measured on condition of the following.

Synthesis example 1
In a flask equipped with a thermometer, dropping funnel, condenser, fractionator, and stirrer, 132 g of polycondensate of dicyclopentadiene and phenol (hydroxyl equivalent: 180 g / eq, softening point: 115 ° C.) and α-naphthol 57 .6 g (0.6 mol)
And 801 g of toluene were charged, and the system was purged with nitrogen under reduced pressure to dissolve. Then
Isophthalic acid chloride 121.2g (0.40mol)
Thereafter, the inside of the system was controlled to 60 ° C. or lower while purging with nitrogen gas, and 244.8 g of a 20% aqueous sodium hydroxide solution was added dropwise over 3 hours. Stirring was then continued for 1.0 hour under these conditions. After completion of the reaction, the solution was allowed to stand for separation, and the aqueous layer was removed. Further, water was added to the toluene phase in which the reaction product was dissolved, and the mixture was stirred and mixed for about 15 minutes. This operation was repeated until the pH of the aqueous layer became 7. Thereafter, water was removed by decanter dehydration, and subsequently toluene was removed by vacuum dehydration to obtain an active ester resin (A-1). The functional group equivalent of this active ester resin (B-1) was 223 g / equivalent from the charging ratio, and the softening point was 152 ° C.

Synthesis example 2
A flask equipped with a thermometer, a dropping funnel, a condenser tube, a fractionating tube, and a stirrer was charged with 100 g of active ester resin (A-1) and 300 g of toluene, and the system was dissolved by substituting with nitrogen under reduced pressure. Next, 100 g of a polycondensate of dicyclopentadiene and phenol (hydroxyl equivalent: 180 g / eq, softening point: 115 ° C.) (A-2) was charged, and the inside of the system was controlled to 80 ° C. or less while purging with nitrogen gas. Dissolved. After confirming dissolution, water was added to the toluene phase in which the reaction product was dissolved, and the mixture was stirred and mixed for about 15 minutes. Thereafter, water was removed by decanter dehydration, and subsequently toluene was removed by vacuum dehydration to obtain an active ester resin (A-3). The functional group equivalent of this active ester resin (A-3) was 199 g / equivalent from the charging ratio, and the softening point was 135 ° C.

Examples 1 and 2 and Comparative Examples 1 to 4 (Adjustment of epoxy resin composition and evaluation of physical properties)
In accordance with the composition shown in Table 1 below, as an epoxy resin, DIC N-680 (orthocresol novolac type epoxy resin, epoxy equivalent: 183 g / eq), or DIC HP-7200H (dicyclopentadiene / phenol type epoxy resin) , Epoxy equivalent: 275 g / eq), (A-1) to (B-3) are blended as curing agents, and 0.1 phr of dimethylaminopyridine is further added as a curing catalyst. Methyl ethyl ketone was blended and adjusted so that the minute (NV) was 58% by mass.
Next, a laminate was prepared by curing under the following conditions, and heat resistance, dielectric properties and flame retardancy were evaluated by the following methods. The results are shown in Table 1.

<Laminate production conditions>
Base material: Glass cloth “# 2116” (210 × 280 mm) manufactured by Nitto Boseki Co., Ltd.
Number of plies: 6 Condition of prepreg: 160 ° C
Curing conditions: 200 ° C., 40 kg / cm ² for 1.5 hours, post-mold thickness: 0.8 mm

<Heat resistance (glass transition temperature)>
Using a viscoelasticity measuring device (DMA: “EXTRA6000” manufactured by SII; frequency 1 Hz, temperature increase rate 3 ° C./min), the temperature at which the elastic modulus change is maximum (the tan δ change rate is the highest) is defined as the glass transition temperature. evaluated.

<Measurement of dielectric constant and dissipation factor>
In accordance with JIS-C-6481, 1 GHz of the test piece after being stored in a room at 23 ° C. and 50% humidity for 24 hours using the cavity resonance method using a network analyzer “E8362C” manufactured by Agilent Technologies, Inc. The dielectric constant and dielectric loss tangent at were measured.

Claims (11)

An epoxy resin and an epoxy resin curing agent as essential components, wherein the epoxy resin curing agent is a phenol compound via an aliphatic cyclic hydrocarbon group. Activity having a structure obtained by reacting a phenol resin (a-1) having a knotted molecular structure, an aromatic dicarboxylic acid or its halide (a-2), and an aromatic monohydroxy compound (a-3) A thermosetting resin composition comprising a combination of an ester resin (A1) and a polyfunctional phenol compound (A2) having a structure in which an unsaturated alicyclic compound and a phenol compound are polyaddition-reacted. The active ester resin (A1) is represented by the following structural formula (1)

(In the formula, X is a benzene ring, naphthalene ring, benzene ring or naphthalene ring substituted with an alkyl group having 1 to 4 carbon atoms, a biphenyl group, Y is a benzene ring, naphthalene ring, or 1 to 4 carbon atoms. (It is a benzene ring or a naphthalene ring nucleus-substituted with an alkyl group, k represents 0 or 1, and n is an average of repeating units of 0.25 to 1.5.)
The thermosetting resin composition according to claim 1, which is represented by: The thermosetting resin composition according to claim 1, wherein the active ester resin (A1) has a softening point in the range of 100 to 180 ° C. The thermosetting resin composition according to claim 1, wherein the epoxy resin curing agent is used as a mixture of the active ester resin (A1) and the polyfunctional phenol compound (A2). The blending ratio [(A1) / (A2)] of the active ester resin (A1) and the polyfunctional phenol compound (A2) is a ratio of 30/70 to 70/30 on a mass basis. Thermosetting resin composition. The blending ratio of the epoxy resin, the active ester resin (A1) and the polyfunctional phenol compound (A2) is a molar ratio [epoxy group in the epoxy resin / (carbonyloxy group in the active ester resin (A1) + The phenolic hydroxyl group in the polyfunctional phenol compound (A2) is a ratio of 0.8 / 1.2 to 1.2 / 0.8, and the mass ratio [(A1) / (A2)] The thermosetting resin composition according to claim 1, wherein the ratio is 30/70 to 70/30 on a mass basis. Hardened | cured material formed by hardening | curing the thermosetting resin composition as described in any one of Claims 1-6. In addition to the epoxy resin and the epoxy resin curing agent in the thermosetting resin composition according to any one of claims 1 to 6, further containing an inorganic filler in a proportion of 70 to 95% by mass in the composition. A semiconductor sealing material comprising a thermosetting resin composition. A prepreg obtained by impregnating a reinforcing substrate with the thermosetting resin composition according to any one of claims 1 to 6 diluted in an organic solvent, and semi-curing the resulting impregnated substrate. By obtaining a varnish obtained by diluting the thermosetting resin composition according to any one of claims 1 to 6 in an organic solvent, and forming the plate and a copper foil by heat and pressure molding The resulting circuit board. A build-up film, wherein the thermosetting resin composition according to any one of claims 1 to 6 is diluted with an organic solvent and applied onto a base film and dried.