JP7087963B2 - Epoxy resin compositions, multilayer printed wiring boards, and semiconductor devices - Google Patents

Description

The present invention relates to an epoxy resin composition suitable for an insulating layer of a multilayer printed wiring board and a semiconductor device using the same.

In recent years, the miniaturization and high performance of electronic devices have progressed, and in the multi-layer printed wiring board, miniaturization and high density of wiring are required. Furthermore, in the next generation, materials for the high frequency band are required, and transmission loss reduction is essential as a noise countermeasure. Therefore, it is required to use an insulating material with excellent dielectric properties for the insulating layer of the multilayer printed wiring board. ing.

As an insulating material for a multilayer printed wiring board, an epoxy resin composition containing an epoxy resin, a specific phenolic curing agent, a phenoxy resin, rubber particles, a polyvinyl acetal resin and the like disclosed in Patent Documents 1 and 2 is known. However, it has been found that these materials are not satisfactory for high frequency band applications.

On the other hand, Patent Document 3 reports that an epoxy resin composition containing an epoxy resin, an active ester compound and a triazine-containing cresol novolak resin is effective for low dielectric loss tangent, but this material also has lower dielectric loss tangent. It is necessary to change it. Further, Patent Document 4 is for an insulating layer of a multilayer printed wiring board, and can bring about a cured product having a low dielectric loss tangent, and can suppress smearing in a via hole when the cured product is drilled. An epoxy resin composition is disclosed, and Patent Document 5 discloses that a resin composition containing an epoxy resin and an active ester compound as essential components becomes a cured product having a low dielectric loss tangent and is useful as an insulating material.

On the other hand, Patent Documents 6 and 7 report that a resin film composed of a bismaleimide resin having a long-chain alkyl group as a non-epoxy material and a resin composition containing a curing agent has excellent low dielectric properties.

Japanese Unexamined Patent Publication No. 2007-254709 JP-A-2007-254710 Japanese Unexamined Patent Publication No. 2011-132507 Japanese Unexamined Patent Publication No. 2015-101626 Japanese Unexamined Patent Publication No. 2017-210527 Republished 2016/114286 Gazette Republished 2016/114287 Gazette

The compositions described in Patent Documents 4 and 5 have been difficult to form into a film because the flexible component needs to be reduced in order to maintain a low dielectric loss tangent. When the cured product of the resin composition of Patent Document 4 is to be used for a multilayer printed wiring board or the like, the dielectric loss tangent is low, but the relative permittivity is not so low, so that the dielectric properties are sufficiently suitable for the application. I couldn't say.
Further, the cured product of the resin composition of Patent Documents 6 and 7 has a low crosslink density and a strong rubber-like property, and when the cured product is drilled, cutting chips called smears are generated in the via hole. There was a problem that it was easy and it was difficult to remove the smear.

Therefore, an object of the present invention is an epoxy resin composition useful for high frequency applications, which provides a cured product having excellent handleability when formed into a film, excellent dielectric properties, and suppressed smearing. And to provide a multilayer printed wiring board manufactured by using the epoxy resin composition.

As a result of diligent research to solve the above problems, the present inventors have found that the following epoxy resin composition can achieve the above object, and have completed the present invention.
That is, the present invention provides a multilayer printed wiring board having an insulating layer made of the following epoxy resin composition and a cured product of the composition.

<1>
An epoxy resin composition containing the following components (A) to (E).
At least one in the smear inhibitor (D) molecule, which is one or more resins selected from the group consisting of (A) epoxy resin (B) active ester curing agent (C) alkoxyalkylated melamine resin and alkoxyalkylated phenolic resin. Maleimide compound (E) curing accelerator containing one dimer acid skeleton, at least one linear alkylene group having 6 or more carbon atoms, and at least two cyclic imide groups.

<2>
The epoxy resin composition according to <1>, which further contains an inorganic filler as a component (F).

（一般式（１）中、Ａは独立して芳香族環または脂肪族環を含む４価の有機基を示す。Ｂは２価のヘテロ原子を含んでもよい脂肪族環を有する炭素数６から１８のアルキレン鎖である。Ｑは独立して炭素数６以上の直鎖アルキレン基を示す。Ｒは独立して炭素数６以上の直鎖又は分岐鎖のアルキル基を示す。ｎは１～１０の数を表す。ｍは０～１０の数を表す。） <3>
The epoxy resin composition according to <1> or <2>, wherein the cyclic imide compound of the component (D) is represented by the following general formula (1).

(In the general formula (1), A independently represents a tetravalent organic group containing an aromatic ring or an aliphatic ring. B has an aliphatic ring having a divalent heteroatom and may contain a divalent heteroatom from 6 carbon atoms. It is an alkylene chain of 18. Q independently indicates a linear alkylene group having 6 or more carbon atoms. R independently indicates a linear or branched alkyl group having 6 or more carbon atoms. N indicates 1 to 10 Represents the number of. M represents the number of 0 to 10.)

（なお、上記構造式中の置換基が結合していない結合手は、一般式（１）において環状イミド構造を形成するカルボニル炭素と結合するものである。） <4>
The epoxy resin composition according to <3>, wherein A of the formula (1) is any one represented by the following structure.

(Note that the bond to which the substituent in the above structural formula is not bonded is one that bonds to the carbonyl carbon forming the cyclic imide structure in the general formula (1).)

<5>
(E) The epoxy resin composition according to any one of <1> to <4>, wherein the curing accelerator as a component is an anionic curing accelerator.

<6>
A multilayer printed wiring board having an insulating layer formed by a cured product of the epoxy resin composition according to any one of <1> to <5>.

<7>
A semiconductor device having a cured product of the epoxy resin composition according to any one of <1> to <5>.

The epoxy resin composition of the present invention has excellent handleability when made into a film, and the cured product has excellent dielectric properties and less smear generation. Therefore, an adhesive film, prepreg or multilayer printed wiring board especially for high frequencies is used. It is useful for.

Hereinafter, the present invention will be described in more detail.

(A) Epoxy resin The epoxy resin of the component (A) used in the present invention preferably has two or more epoxy groups in one molecule. For example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, tert-butyl-catechol type epoxy resin, naphthalene type epoxy resin, naphthalenediol type epoxy resin, glycidylamine type epoxy resin, biphenyl type epoxy resin, phenol biphenyl type epoxy resin. , Biphenyl aralkyl type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, bisphenol A novolac type epoxy resin, trisphenylol methane type epoxy resin, tetrakisphenilol ethane type epoxy resin, dicyclopentadiene type epoxy resin fragrance Examples thereof include an epoxy resin in which the ring is hydrogenated, an epoxy resin in which the aromatic ring of the phenoldicyclopentadiennovolac type epoxy resin is hydrogenated, a triazine derivative epoxy resin, and an alicyclic epoxy resin.

The epoxy resin may be used alone or in combination of two or more, and when two or more are used in combination, the epoxy resin having two or more epoxy groups in one molecule is at least 50% by mass in the component (A). It is preferable to include it.
Further, in order to make the epoxy resin composition flexible in the state before curing, to be excellent in handling (handlerability), and to easily improve the breaking strength after curing, a liquid epoxy resin at 25 ° C and a liquid epoxy resin at 25 ° C are used. A solid epoxy resin may be used in combination. When a liquid epoxy resin at 25 ° C and a solid epoxy resin at 25 ° C are used in combination, the mixing ratio of these is 10 to 90% by mass of the liquid epoxy resin at 25 ° C and the solid epoxy resin at 25 ° C. It is preferably 10 to 90% by mass (however, the total of the liquid epoxy resin at 25 ° C. and the solid epoxy resin at 25 ° C. is 100% by mass).

(B) Active ester-based curing agent The active ester-based curing agent is not particularly limited, but generally reacts with phenol esters, thiophenol esters, N-hydroxyamine esters, esters of heterocyclic hydroxy compounds and the like. A compound having two or more ester groups (active ester groups) having a high ester group (active ester group) in one molecule is preferably used. The active ester-based curing agent is preferably obtained by a condensation reaction between a carboxylic acid compound and / or a thiocarboxylic acid compound and a hydroxy compound and / or a thiol compound. Of these, an active ester-based curing agent obtained from a carboxylic acid compound and a hydroxy compound is preferable, and an active ester-based curing agent obtained from a carboxylic acid compound and a phenol compound and / or a naphthol compound is more preferable.

Examples of the carboxylic acid compound include an aliphatic carboxylic acid having 1 to 20 carbon atoms (preferably 2 to 10, more preferably 2 to 8) and an aromatic having 7 to 20 carbon atoms (preferably 7 to 10). Carboxylic acid can be mentioned. Suitable aliphatic carboxylic acids include, for example, acetic acid, malonic acid, succinic acid, maleic acid, itaconic acid and the like. Suitable aromatic carboxylic acids include, for example, benzoic acid, phthalic acid, isophthalic acid, terephthalic acid, pyromellitic acid and the like.

Examples of the phenol compound include phenol compounds having 6 to 40 carbon atoms (preferably 6 to 30, more preferably 6 to 23, still more preferably 6 to 22), and preferred specific examples include hydroquinone. Resolcin, bisphenol A, bisphenol F, bisphenol S, phenolphthalin, methylated bisphenol A, methylated bisphenol F, methylated bisphenol S, phenol, o-cresol, m-cresol, p-cresol, catechol, dihydroxybenzophenone, tri Examples thereof include hydroxybenzophenone, tetrahydroxybenzophenone, fluoroglucin, benzenetriol, dicyclopentadiene-type diphenol and the like. Phenolic novolak may also be used as the phenol compound.
Examples of the naphthol compound include naphthol compounds having 10 to 40 carbon atoms (preferably 10 to 30, more preferably 10 to 20), and suitable specific examples thereof include α-naphthol, β-naphthol, and 1 , 5-Dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene and the like. As the naphthol compound, naphthol novolak may also be used.

Suitable specific examples of the active ester-based curing agent include an active ester compound containing a dicyclopentadiene-type diphenol structure, an active ester compound containing a naphthalene structure, an active ester compound containing an acetylated phenol novolak structure, and benzoylated. Examples thereof include an active ester compound containing a phenol novolak structure, and among them, an active ester compound containing a naphthalene structure and an active ester compound containing a dicyclopentadiene type diphenol structure are more preferable. In the present invention, the "dicyclopentadiene-type diphenol structure" represents a divalent structural unit composed of phenylene-dicyclopentalene-phenylene.

式（２）中、Ｒ”はフェニル基又はナフチル基を示し、ａは０または１であり、ｂは繰り返し単位の平均値で０．０５～２．５０である。 Specific examples of the active ester compound containing a dicyclopentadiene-type diphenol structure include those represented by the following general formula (2).

In the formula (2), R "represents a phenyl group or a naphthyl group, a is 0 or 1, and b is an average value of repeating units of 0.05 to 2.50.

As the active ester-based curing agent for the component (B), a commercially available product can be used. Commercially available active ester-based curing agents include EXB9451, EXB9460, EXB9460S, EXB9460S-65T (all manufactured by DIC Co., Ltd.) and acetylated phenol as active ester compounds containing a dicyclopentadiene-type diphenol structure. DC808 as an active ester compound containing a novolak structure, YLH1026, YLH1030, YLH1048 (above, manufactured by Mitsubishi Chemical Corporation) as an active ester compound containing a benzoylated phenol novolak structure, and EXB9416- as an active ester compound containing a naphthalene structure. Examples include 70BK (manufactured by DIC Co., Ltd.).

From the viewpoint of the dielectric properties and heat resistance of the cured product, the component (B) is preferably an active ester compound in which R "is a naphthyl group, a = 0, and b = 0.25 to 1.25 in the formula (2). The active ester-based curing agent may be used alone or in combination of two or more.

The blending amount of the component (B) is such that the equivalent ratio of the active ester group in the component (B) to the epoxy group in the component (A) is 0.5 to 2.0, preferably 0.7. It is an amount of up to 1.5. If the equivalent ratio is less than 0.5 or more than 2.0, curability, mechanical properties, etc. may deteriorate.

(C) Smear Suppressant The (C) Smear Suppressant in the present invention is used after the cured product of the resin composition is drilled and roughened when a multilayer printed wiring board is produced using the resin composition. It is an additive for suppressing smear (resin cutting chips) in the via hole. Here, suppressing smear in the present invention includes both meanings of reducing the amount of smear generated during drilling and making it easier to remove smear during roughening.

The smear inhibitor is one or more resins selected from the group consisting of an alkoxyalkylated melamine resin and an alkoxyalkylated phenol resin, and may be used alone or in combination of two or more.

In the alkoxyalkylated melamine resin, melamine is reacted with formaldehyde to replace a part or all of the hydrogen atoms of the amino group with a methylol group to obtain methylol melamine, and then further reacted with an aliphatic alcohol to partially react with an aliphatic alcohol to form a part of the methylol group. Alternatively, it is a resin obtained by polycondensing by heating a product that has been completely modified to an alkoxymethyl group.

一般式（３）中、Ｘは独立して、水素原子、－ＣＨ₂－Ｏ－Ｒ¹で表される基、又はメチレン基を表し、ここでＲ¹は水素原子または炭素数１から２０のアルキル基である。但し、Ｘの少なくとも１つは、式：－ＣＨ₂－Ｏ－Ｒ¹で表される基である。
すなわち、一般式（３）で表される構造単位は、
－Ｎ（－ＣＨ₂－Ｏ－Ｒ¹）₂で表される官能基
－Ｎ（－ＣＨ₂－Ｏ－Ｒ¹）－ＣＨ₂－で表される官能基
－Ｎ（－ＣＨ₂－Ｏ－Ｒ¹）Ｈで表される官能基
のうち１以上を有する。

Specifically, the alkoxyalkylated melamine resin has a structural unit represented by the following general formula (3).

In the general formula (3), X independently represents a hydrogen atom, a group represented by -CH ₂ -OR ^{1, or a methylene group, where R 1 is} a hydrogen atom or a group having 1 to 20 carbon atoms. It is an alkyl group. However, at least one of X is a group represented by the formula: -CH ₂ -OR ¹ .
That is, the structural unit represented by the general formula (3) is
-N (-CH ₂ -OR ^{1) Functional group represented by 2 -N (-CH 2-OR 1} _{) -CH 2 -} ^Functional _group represented by -N (-CH ₂ -O-" R ¹ ) It has one or more of the functional groups represented by H.

The alkyl group having 1 to 20 carbon atoms represented by R ¹ in the general formula (3) is preferably an alkyl group having 1 to 10 carbon atoms. The alkyl group may be linear or branched, for example, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, and the like. Examples thereof include a hexyl group, a heptyl group and an octyl group.

In the general formula (3), at least one of X is a group represented by -CH ₂ -OR ¹ . In a preferred embodiment, of X, preferably two or more, more preferably three or more, still more preferably four or more are the groups represented by _—CH2 ^- OR1. When a plurality of R ^1s exist in the formula (3), they may be the same or different from each other.

When X is a methylene group in the structural unit represented by the general formula (3), the alkoxyalkylated melamine resin is a polymer having the structural unit of the general formula (3) as a repeating unit. The weight average molecular weight (Mw) of the alkoxyalkylated melamine resin is preferably 300 to 10,000 in terms of the polystyrene standard measured by gel permeation chromatography (GPC). More preferably, it is 350 to 5,000. If the molecular weight is 300 or more, it is a high-purity monomolecular alkoxyalkylated melamine resin, and if it exceeds 10,000, the flexibility of the sheet may be impaired.

The weight average molecular weight (Mw) referred to in the present invention refers to the weight average molecular weight using polystyrene obtained by GPC measured under the following conditions as a standard substance.
[Measurement condition]
Developing solvent: Tetrahydrofuran Flow rate: 0.35 mL / min
Detector: RI
Column: TSK-GEL H type (manufactured by Tosoh Corporation)
Column temperature: 40 ° C
Sample injection volume: 5 μL

Examples of the alkoxyalkylated melamine resin include methoxymethylated melamine resins (manufactured by Sanwa Chemical Co., Ltd.) such as Nicarac MW-390, Nicarac MW-100L, and Nicarac MX-750LM, Amidia J-820-60, and Amidia L-117. Butylated melamine resin such as -60 and Amidia L-109-65, isobutylized melamine resin such as Amidia L-125-60 and Amidia L-166-60B, and methylated melamine resin such as Amidia L-105-60 (either A commercially available product such as (manufactured by DIC Co., Ltd.) can be used. Further, the alkoxyalkylated melamine resin may be used alone or in combination of two or more.

Ｙは、水素原子、炭素数１～６のアルキレン基又は単結合であり、Ｚ¹は、－ＣＨ（Ｒ²）－Ｏ－Ｒ³で表される基を表し、ここでＲ²は水素原子、炭素数１～６のアルキル基、フェニル基又はヒドロキシフェニル基であり、Ｒ³は炭素数１～６のアルキル基である。Ｚ²は、単結合、炭素数１～６のアルキレン基又は炭素数１～４のアルカントリイル基である。Ｚ³は、水酸基やアミノ基等の置換基を有していてもよい炭素数１～８のアルキル基を表し、ｌ、ｍ及びｎは、２≦ｌ＋ｍ＋ｎ≦５かつ１≦ｌを満たす整数である。
Ｙ及びＺ²で表される炭素数１～６のアルキレン基としては、メチレン基、エチレン基、プロピレン基、トリメチレン基、テトラエチレン基等が挙げられる。
また、Ｒ²及びＲ³で表される炭素数１～６のアルキル基としては、例えば、メチル基、エチル基、プロピル基、イソプロピル基、ブチル基、イソブチル基、sec－ブチル基、tert－ブチル基、ヘキシル基等が挙げられる。
Ｚ²で表される炭素数１～４のアルカントリイル基としては、メタントリイル基、エタントリイル基、プロパントリイル基、ブタントリイル基等が挙げられる。
Ｚ³で表される炭素数１～８のアルキル基としては、例えば、メチル基、エチル基、プロピル基、イソプロピル基、ブチル基、イソブチル基、sec－ブチル基、tert－ブチル基、ヘキシル基、ヘプチル基、オクチル基等が挙げられる。 The alkoxyalkylated phenolic resin is a functional group represented by -CH (R ² ) -OR ³ (in the formula, R ² is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a phenyl group or a hydroxyphenyl group. R ³ is an alkyl group having 1 to 6 carbon atoms) and is a phenolic resin containing a phenolic skeleton. The alkoxyalkylated phenol resin is a phenol resin containing a structural unit represented by the following general formula (4).

Y represents a hydrogen atom, an alkylene group having 1 to 6 carbon atoms or a single bond, Z ¹ represents a group represented by -CH (R ² ) -OR ³ , where R ² is a hydrogen atom. , An alkyl group having 1 to 6 carbon atoms, a phenyl group or a hydroxyphenyl group, and R ³ is an alkyl group having 1 to 6 carbon atoms. Z ² is a single bond, an alkylene group having 1 to 6 carbon atoms or an alkanetriyl group having 1 to 4 carbon atoms. Z ³ represents an alkyl group having 1 to 8 carbon atoms which may have a substituent such as a hydroxyl group or an amino group, and l, m and n are integers satisfying 2 ≦ l + m + n ≦ 5 and 1 ≦ l. be.
Examples of the alkylene group having 1 to 6 carbon atoms represented by Y and Z ² include a methylene group, an ethylene group, a propylene group, a trimethylene group, a tetraethylene group and the like.
Examples of the alkyl group having 1 to 6 carbon atoms represented by R ² and R ³ include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group and a tert-butyl. Groups, hexyl groups and the like can be mentioned.
Examples of the alkanetriyl group having 1 to 4 carbon atoms represented by Z ² include a methanetriyl group, an ethanetriyl group, a propanetriyl group, and a butanetriyl group.
Examples of the alkyl group having 1 to 8 carbon atoms represented by Z ³ include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group and a hexyl group. Examples thereof include a heptyl group and an octyl group.

When Y is an alkylene group or a single bond or Z ² is a single bond, an alkylene group or an alkanetriyl group in the structural unit represented by the general formula (4), the alkoxyalkylated phenol resin is the general formula (4). ) Is a polymer having a structural unit as a repeating unit. The weight average molecular weight (Mw) of the alkoxyalkylated phenol form is preferably 200 to 10,000 in terms of the polystyrene standard measured by gel permeation chromatography (GPC). More preferably, it is 300 to 5,000. If the molecular weight is 200 or more, it is a high-purity monomolecular alkoxyalkylated phenol resin, and if it exceeds 10,000, the flexibility of the sheet may be impaired.

The content of the component (C) in the resin composition of the present invention is the total amount of the component (A), the component (B) and the component (D) described later, in consideration of the ability to prevent deterioration of physical properties after curing and suppress smear. Is 100% by mass, 1% by mass to 30% by mass is preferable, and 2% by mass to 25% by mass is more preferable.

(D) Cyclic imide compound The component (D) is a cyclic imide compound having at least one dimer acid skeleton, at least one linear alkylene group having 6 or more carbon atoms, and at least two cyclic imide groups in the molecule. .. Since the cyclic imide compound of the component (D) has a linear alkylene group having 6 or more carbon atoms, the cured product of the composition containing this has not only excellent dielectric properties but also a reduced phenyl group content ratio. , Tracking resistance is improved. Further, since the cyclic imide compound of the component (D) has a linear alkylene group, it is possible to reduce the elasticity of the cured product of the composition containing the linear imide compound, and it is also effective in reducing the stress on the semiconductor device due to the cured product. Is.
Further, from the viewpoint of handleability of the uncured composition, the cyclic imide compound of the component (D) is preferably a solid at 25 ° C.

一般式（１）中、Ａは独立して芳香族環または脂肪族環を含む４価の有機基を示す。Ｂは２価のヘテロ原子を含んでもよい脂肪族環を有する炭素数６から１８のアルキレン基である。Ｑは独立して炭素数６以上の直鎖アルキレン基を示す。Ｒは夫々独立に炭素数６以上の直鎖又は分岐鎖のアルキル基を示す。ｎは１～１０の数を表す。ｍは０～１０の数を表す。 Further, among them, the cyclic imide compound of the component (D) is preferably a maleimide compound, and it is more preferable to use a maleimide compound represented by the following general formula (1).

In the general formula (1), A independently represents a tetravalent organic group containing an aromatic ring or an aliphatic ring. B is an alkylene group having 6 to 18 carbon atoms having an aliphatic ring which may contain a divalent heteroatom. Q independently represents a linear alkylene group having 6 or more carbon atoms. R independently represents a linear or branched alkyl group having 6 or more carbon atoms. n represents a number from 1 to 10. m represents a number from 0 to 10.

Q in the formula (1) is a linear alkylene group, and the number of carbon atoms thereof is 6 or more, preferably 6 or more and 20 or less, and more preferably 7 or more and 15 or less.

Further, R in the formula (1) is an alkyl group, which may be a linear alkyl group or a branched alkyl group, and the number of carbon atoms thereof is 6 or more, preferably 6 or more and 12 or less.

（なお、上記構造式中の置換基が結合していない結合手は、一般式（１）において環状イミド構造を形成するカルボニル炭素と結合するものである。） A in the formula (1) represents a tetravalent organic group containing an aromatic ring or an aliphatic ring, and is particularly preferably any of the tetravalent organic groups represented by the following structural formula.

(Note that the bond to which the substituent in the above structural formula is not bonded is one that bonds to the carbonyl carbon forming the cyclic imide structure in the general formula (1).)

（なお、上記構造式中の置換基が結合していない結合手は、一般式（１）において環状イミド構造を形成する窒素原子と結合するものである。） Further, B in the formula (1) is an alkylene group having 6 to 18 carbon atoms having an aliphatic ring which may contain a divalent heteroatom, and the carbon number of the alkylene group is preferably 8 or more and 15 or less. Is. B in the formula (1) is preferably any of the alkylene groups having an aliphatic ring represented by the following structural formula.

(Note that the bond to which the substituent in the above structural formula is not bonded is one that bonds to the nitrogen atom forming the cyclic imide structure in the general formula (1).)

In the formula (1), n is a number of 1 to 10, preferably a number of 2 to 7. In the formula (1), m is a number of 0 to 10, preferably a number of 0 to 7.

The weight average molecular weight (Mw) of the cyclic imide compound as the component (D) is not particularly limited including the properties at room temperature, but is preferably in the range of being solid at room temperature, and is measured by gel permeation chromatography (GPC). The weight average molecular weight converted by the polystyrene standard is more preferably 2,000 to 50,000, and particularly preferably 2,500 to 40,000. If the molecular weight is 2,000 or more, the obtained maleimide compound tends to solidify, and if it is less than 2,000, the composition before curing tends to have tack. When the molecular weight is 50,000 or less, the obtained composition does not have a possibility that the viscosity becomes too high and the fluidity decreases, and the formability such as laminating molding becomes good.

As the cyclic imide compound of the component (D), a commercially available product such as BMI-2500, BMI-2560, BMI-3000, BMI-5000, (all manufactured by Designer Moleculars Inc.) can be used. Further, the cyclic imide compound may be used alone or in combination of two or more.

In the composition of the present invention, the sum of the component (A), the component (B), and the component (D) (hereinafter, the component (A), the component (B), and the component (D) are collectively referred to as a "resin component". ), The component (D) is 5 to 95% by mass, preferably the component (D) is 6 to 80% by mass, and more preferably the component (D) is 7 to 70% by mass. The ratio of the component (A) and the component (B) shall follow the range of the equivalent ratio already mentioned.

(E) Curing Accelerator A curing accelerator is added as a component (E) to the epoxy resin composition of the present invention. The curing accelerator is a reaction of the epoxy group of the epoxy resin of the component (A), the reactive group (active ester group) of the active ester-based curing agent of the component (B), and the cyclic imide group of the cyclic imide compound of the component (D). It is for promotion.

In general, radical reaction initiators are often used to accelerate the reaction of cyclic imide groups. In the case of the present invention, it is not preferable to use the radical reaction initiator alone in consideration of the reaction with the epoxy group, the active ester group and the phenolic hydroxyl group, but it may be used in combination with the anionic curing accelerator.

The curing accelerator of the component (E) is not particularly limited as long as it promotes the curing reaction of a general epoxy resin composition. Of these, anionic curing accelerators are preferably used. Examples of anionic curing accelerators include amine compounds such as 1,8-diazabicyclo [5,4,0] -7-undecene; organophosphorus compounds such as triphenylphosphine and tetraphenylphosphonium tetrabolate salts; Examples thereof include imidazole-based compounds such as 2-methylimidazole and 1-benzyl-2-phenylimidazole, and imidazole-based compounds are preferably used.

Regardless of the type, these curing accelerators may be used alone or in combination of two or more.
The amount of the component (E) added is 0.1 to 10 parts by mass with respect to 100 parts by mass of the total of the components (A), (B) and (D), that is, 100 parts by mass of the total of the resin components. It is preferably 0.2 parts by mass to 5 parts by mass.

In the present invention, any of the following components can be blended in addition to the above components.

(F) Inorganic filler The inorganic filler as a component (F) increases the strength and rigidity of the cured product and adjusts the coefficient of thermal expansion when the epoxy resin composition of the present invention is formed into a film. It is blended in. As the inorganic filler of the component (F), those usually blended in an epoxy resin composition or a silicone resin composition can be used. For example, silicas such as spherical silica, fused silica and crystalline silica, alumina, silicon nitride, aluminum nitride, boron nitride, barium sulfate, talc, clay, aluminum hydroxide, magnesium hydroxide, calcium carbonate, glass fiber and glass. Examples include particles. Further, a fluororesin-containing and / or a coating filler may be mentioned for improving the dielectric property.

The average particle size and shape of the inorganic filler of the component (F) are not particularly limited, but spherical silica having an average particle size of 0.5 to 5 μm is particularly preferably used when molding into a film. The average particle size is a value obtained as the mass average value D ₅₀ (or the median diameter) in the particle size distribution measurement by the laser light diffraction method.

The blending amount of the inorganic filler of the component (F) is preferably 40 to 800 parts by mass, particularly 50 to 700 parts by mass with respect to 100 parts by mass of the total resin component. If it is less than 40 parts by mass, not only the CTE of the cured product becomes large, but also sufficient strength may not be obtained. If it exceeds 800 parts by mass, the flexibility of the film is lost and the appearance is poor. May be done. The inorganic filler is preferably contained in the range of 30 to 90% by mass, particularly 35 to 85% by mass of the entire composition.

<Other additives>
Various additives can be further added to the epoxy resin composition of the present invention, if necessary. Other thermosetting resins such as organopolysiloxane, silicone oil, and cyanate resin, thermoplastic resins, thermoplastic elastomers, and organic synthetic rubbers are used as the additives to improve the resin properties without impairing the effects of the present invention. Light stabilizers, pigments, dyes, etc. may be blended, coupling agents for improving wettability with fillers and adhesion to substrates, ion trapping agents for improving electrical properties, flame retardants. A non-halogen-based flame retardant typified by a phosphorus compound or a metal hydrate may be blended to impart the above. Further, a fluorine-containing material or the like may be blended in order to improve the dielectric property.

Method for Producing Epoxy Resin Composition The method for producing the epoxy resin composition of the present invention is not particularly limited. For example, there is a method in which the components (A) to (D) and, if necessary, other components are blended in a predetermined composition ratio and sufficiently uniformly mixed, stirred, dissolved, dispersed and / or melt-kneaded with a mixer or the like. Be done. Each component may be blended at the same time or separately, or may be mixed while heating if necessary.
The device for mixing and the like is not particularly limited, and specific examples thereof include a Raikai machine equipped with a stirring and heating device, a two-roll mill, a three-roll mill, a ball mill, a planetary mixer, a mascoroider, and the like. The devices may be used in combination as appropriate.

The epoxy resin composition of the present invention is cured under the conditions of a temperature of 150 to 200 ° C. and a time of 1 to 24 hours to obtain a cured product having excellent heat resistance, a low relative permittivity and a low dielectric loss tangent. Further, the composition may be cured by a method described later as appropriate depending on the use or form of the composition described in detail below.

The epoxy resin composition of the present invention can be used in a wide range of applications such as circuit boards for adhesive films, prepregs, multilayer printed wiring boards, solder resists, underfill materials, die bonding agents, semiconductor encapsulants, etc. It can be suitably used for forming an insulating layer of a multilayer printed wiring board.

As the epoxy resin composition of the present invention, the resin composition produced by the above-mentioned method may be used as it is, or may be used as a varnish, depending on various uses, and may be molded into a film (that is, film-like laminated). It may be used from (as a material). In the case of a film-like laminated material, the softening point of the epoxy resin composition is preferably 40 to 140 ° C. from the viewpoint of laminating property.

[varnish]
The varnish contains the epoxy resin composition of the present invention and an organic solvent, and contains the above-mentioned components (A) to (E), the organic solvent and, if necessary, other components in a predetermined composition ratio, for example. However, it can be manufactured by kneading with a three-roll, ball mill, bead mill, sand mill or the like as needed, or by stirring with a planetary mixer or the like as necessary.

Examples of the organic solvent used when the epoxy resin composition of the present invention is a varnish include ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate, acetic acid esters such as carbitol acetate, cellosolve, butyl carbitol and the like. Examples thereof include aromatic hydrocarbons such as carbitols, toluene and xylene, amide solvents such as dimethylformamide, dimethylacetamide and N-methylpyrrolidone, and cyclohexanone. The organic solvent may be used alone or in combination of two or more.

Further, the solid content concentration (nonvolatile content concentration) of the epoxy resin composition of the present invention in the varnish may be appropriately adjusted according to the intended use or form, for example, an organic solvent so that the solid content concentration is 30 to 70% by mass. Is preferably blended, and more preferably 35 to 65% by mass.

[Film-like laminated material]
The film-like laminated material has a resin composition layer made of the epoxy resin composition of the present invention on a support. As a method for producing the film-like laminated material, the epoxy resin composition may be applied as it is on the support, or may be applied as a varnish and then applied with a die coater or the like. When the varnish is applied, the organic solvent can be dried by heating, hot air blowing, or the like to form a resin composition layer on the support.

Examples of the support (support film) include a polyolefin film such as polyethylene, polypropylene and polyvinyl chloride, a polyester film such as polyethylene terephthalate (PET) and polyethylene naphthalate, and various plastic films such as a polycarbonate film and a polyimide film; ; Metal foil such as copper foil and aluminum foil can be mentioned. Among them, a plastic film is preferable, and a PET film is more preferable, from the viewpoint of versatility. The support and the protective film described later may be subjected to surface treatment such as mud treatment and corona treatment. Further, the mold release treatment may be performed with a mold release agent such as a silicone resin-based mold release agent, an alkyd resin-based mold release agent, or a fluororesin-based mold release agent.

[Adhesive film]
As a specific embodiment of the film-like laminated material, an adhesive film can be mentioned.
As a method for producing the adhesive film, a varnish is prepared by the above-mentioned method, the varnish is applied onto the support using a die coater or the like, and the organic solvent is further dried by heating or blowing hot air to dry the resin. Examples thereof include a method of forming a composition layer. The drying conditions are not particularly limited, but it is preferable to dry the resin composition layer so that the content of the organic solvent is 10% by mass or less, preferably 5% by mass or less. Although it depends on the amount of the organic solvent in the varnish and the boiling point of the organic solvent, for example, in the case of a varnish containing 30 to 60% by mass of the organic solvent, the resin composition layer is dried at 50 to 150 ° C. for about 3 to 10 minutes. Can be formed. If it is dried at a higher temperature for a long time, the curing reaction of the composition may proceed and the composition may be cured.
Further, as another manufacturing method of the adhesive film, there is also a method of manufacturing using an extruder equipped with a T-die. In this production method, an epoxy resin composition prepared by melting and mixing each component is used instead of varnish.

The thickness of the resin composition layer of the adhesive film is preferably in the range of 10 to 120 μm. In particular, when the adhesive film is used for a circuit board described later, the thickness of the resin composition layer of the adhesive film is preferably equal to or larger than the thickness of the conductor layer of the circuit board. 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 in the range of 10 to 100 μm, and 15 to 15 to 100 from the viewpoint of thinning the layer. It is more preferably in the range of 80 μm.

Further, a protective film similar to the support may be further laminated on the surface of the resin composition layer that is not in contact with the support. In this case, the adhesive film includes a support, a resin composition layer formed on the support, and a protective film formed on the resin composition layer. The thickness of the protective film is not particularly limited, but may be, for example, 1 to 40 μm. By laminating the protective film, it is possible to prevent dust and the like from adhering to the surface of the resin composition layer and scratches. The adhesive film can be rolled up and stored.

[Prepreg]
The prepreg has the epoxy resin composition of the present invention, and is produced by impregnating or coating a reinforcing base material with the epoxy resin composition of the present invention and heating to semi-cure the epoxy resin composition. be able to.

As the reinforcing base material, for example, those commonly used as prepreg base materials such as glass cloth, quartz glass, aramid non-woven fabric, and liquid crystal polymer non-woven fabric can be used.

Examples of the impregnation or coating method include a hot melt method and a solvent method.
The hot melt method is a method in which the epoxy resin composition of the present invention in a molten state is directly applied to a reinforcing base material by a die coater, or a method of laminating a film-like laminated material produced by the above-mentioned method on the reinforcing base material. be.
The solvent method is a method in which a reinforcing base material is immersed in a varnish prepared by the above-mentioned method and then dried.
Further, the prepreg may be prepared by continuously heat-laminating the adhesive film produced by the above-mentioned method from both sides of the reinforcing base material under heating and pressure conditions. As the support and the protective film, the same adhesive film as described above may be used.

By heating the reinforcing base material impregnated or coated with the epoxy resin composition of the present invention at, for example, 60 to 150 ° C. for 5 to 60 minutes, the epoxy resin composition becomes semi-cured. .. In the prepreg of the present invention, it is preferable that the epoxy resin composition of the present invention is contained in an amount of 25 to 75% by mass with respect to the reinforcing base material.

[Circuit board (multilayer printed wiring board)]
The circuit board of the present invention has an insulating layer which is a cured product of the epoxy resin composition of the present invention. Examples of the substrate used for the circuit board include a glass epoxy substrate, a metal substrate, a polyester substrate, a polyimide substrate, a BT resin substrate, a thermosetting polyphenylene ether substrate, and the like. The circuit board means a circuit board in which a patterned conductor layer (circuit) is formed on one side or both sides of the board as described above, and the conductor layer and the insulating layer are alternately laminated and one side of the outermost layer. Alternatively, a multilayer printed wiring board in which a conductor layer (circuit) patterned on both sides is formed is also included. The surface of the conductor layer may be subjected to a roughening treatment such as blackening treatment or copper etching in advance.

Examples of the method for forming the insulating layer on the circuit board include a method in which the varnish prepared by the above-mentioned method is applied to the circuit board, dried, and heat-cured. Specific examples thereof include a method of applying using a dispenser, drying at 60 to 150 ° C. for 0.5 to 2 hours, and heat curing at 120 to 200 ° C. for 1 to 12 hours. Further, it may be vacuum dried if necessary.

Further, as another method for forming the insulating layer on the circuit board, there is also a method of laminating the film-like laminated material produced by the above-mentioned method on one side or both sides of the circuit board using a vacuum laminator. When the film-shaped laminated material has a protective film, after removing the protective film, the film-shaped laminated material and the circuit board are preheated as necessary, and the film-shaped laminated material is pressurized and heated. Laminate on the circuit board. After laminating, it is preferable to perform a smoothing treatment of the laminated film-shaped laminated material by hot-pressing the film-shaped laminated material under normal pressure, for example. The conditions for the smoothing treatment can be the same as the heat-bonding conditions for the above-mentioned laminate. The smoothing process can be performed by a commercially available laminator. The laminating treatment and the smoothing treatment may be continuously performed using the above-mentioned commercially available vacuum laminator.

After laminating the film-like laminated material on the circuit board, it is cooled to around room temperature, and then the support can be peeled off and the resin composition can be heat-cured to form an insulating layer. The order of peeling can be changed as appropriate. This makes it possible to form an insulating layer on the circuit board. The conditions for heat curing may be appropriately selected depending on the type and content of the resin component in the resin composition, but are preferably 150 ° C. to 220 ° C. for 20 to 180 minutes, and more preferably 160 ° C. to 210 ° C. Is selected in the range of 30 to 120 minutes.

Further, as another method for forming the insulating layer on the circuit board, there is also a method of laminating the film-like laminated material produced by the above-mentioned method on one side or both sides of the circuit board using a vacuum press machine. In this method, the resin composition is heated and cured on the circuit board to form an insulating layer by heating and pressurizing under reduced pressure using a general vacuum hot press machine.

Further, a method of manufacturing a circuit board (multilayer printed wiring board) using the prepreg manufactured by the above-mentioned method can also be mentioned. It can be manufactured by stacking one or a plurality of prepregs of the present invention on an internal circuit board, sandwiching a metal plate via a release film, and pressing and laminating under pressure and heating conditions.

After manufacturing the circuit board, the insulating layer formed on the circuit board is drilled to form via holes and through holes, the surface of the insulating layer is roughened, and plating is formed on the insulating layer. And the conductor layer can be made. These steps can be performed according to a general method for manufacturing a circuit board or a multilayer printed wiring board.

[Semiconductor device]
The semiconductor device of the present invention has a cured product of the epoxy resin composition of the present invention.

Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples.

(A) Epoxy resin (A-1): Bisphenol A type epoxy resin liquid at 25 ° C (jER-828, manufactured by Mitsubishi Chemical Corporation, epoxy equivalent 180)
(A-2): Biphenyl aralkyl type epoxy resin solid at 25 ° C (NC-3000, manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent 291)

(B) Active ester-based curing agent (B-1): Active ester compound-1 (EXB9460S-65T, manufactured by DIC Corporation, active ester equivalent 223, toluene solution having a solid content of 65% by mass)

(C) Smear inhibitor (C-1): Methoxymethylated melamine resin (Nicarac MX-750LM, manufactured by Sanwa Chemical Co., Ltd., non-volatile component 82% by mass)
(C-2): Butylated melamine resin (Amidia L-117-60, manufactured by DIC Corporation, 60% by mass of non-volatile component)
(C-3): Alkoxyalkylated phenol resin (4- (1,1-dimethylethyl) -2,6-bis (methoxymethyl) -phenol, manufactured by AK scientific)

（Ｄ－２）４，４’－ジフェニルメタンビスマレイミド（ＢＭＩ－１０００：大和化成（株）製、比較例用） (D) Cyclic imide compound (D-1): A linear alkylene group-containing maleimide compound represented by the following formula (BMI-3000, manufactured by Designer Molecules Inc.).

(D-2) 4,4'-Diphenylmethanebismaleimide (BMI-1000: manufactured by Daiwa Kasei Co., Ltd., for comparative example)

(E) Curing accelerator (E-1): Imidazole-based curing accelerator (1B2PZ, manufactured by Shikoku Chemicals Corporation)

(F) Inorganic filler (F-1) Fused spherical silica (SO-25R, manufactured by Admatex Co., Ltd., average particle size 0.5 μm)

[Examples 1 to 5, Comparative Examples 1 to 8]
Each component was dissolved and dispersed in cyclohexanone according to the formulation (part by mass) shown in Table 1, and the non-volatile content was adjusted to 60% by mass to obtain a varnish of a resin composition. The number of copies of the component (B) and the component (C) in Table 1 is the value of the solid component. The varnish of the resin composition was applied onto a PET film having a thickness of 38 μm with a roller coater so that the thickness after drying was 50 μm, and dried at 80 to 120 ° C. for 10 minutes to obtain a film.
In Comparative Examples 7 and 8, instead of the film having the resin composition of the present invention on the PET film, commercially available film-like interlayer insulating materials ABF GX13 and GX92 (both manufactured by Ajinomoto Fine-Techno Co., Ltd.) were used. used.

<Film characteristics>
It was visually confirmed whether the film cracked or broke when each film was bent 180 degrees under the condition of 25 ° C. When no crack or break was confirmed, it was marked with ◯, and when crack or break was confirmed even a little, it was marked with x.

<Relative permittivity, dielectric loss tangent>
Each film was cured by performing a step cure at 150 ° C. for 1 hour and then at 200 ° C. for 2 hours. Then, a network analyzer (E5063-2D5 manufactured by Keysight Co., Ltd.) and a strip line (manufactured by Keycom Co., Ltd.) were connected, and the relative permittivity and the dielectric loss tangent of the film at a frequency of 10 GHz were measured.

<Smear inhibitory>
Each film was poured into a 50 mm × 50 mm × 5 mm mold while being melted at 80 ° C., and cured by performing step cure at 150 ° C. for 1 hour and further at 200 ° C. for 2 hours. A CO ₂ laser machine (LC-2Q252, manufactured by Via Mechanics Co., Ltd.) was used for the obtained molded body, and the mask diameter was 1.60 mm, the focus offset value was 0.050, the pulse width was 25 μs, the power was 0.66 W, and the aperture. A via hole was formed by drilling under the conditions of 13, the number of shots 2, and the burst mode. The circumference of the bottom of any five via holes was observed with a scanning electron microscope (SEM, manufactured by KEYENCE), and the maximum smear length was measured from the obtained images. The case where the maximum smear length was less than 4 μm was evaluated as ◯, and the case where the maximum smear length was 4 μm or more was evaluated as ×. The maximum smear length is the maximum length of the smear from the circumference of the bottom surface of the via to the center of the circle, and if even one of the five via holes has a maximum smear length of more than 4 μm, the evaluation is x. did.

As shown in Table 1, the composition of the present invention has excellent film properties, and the cured product has a small dielectric constant and dielectric loss tangent value, has excellent dielectric properties, and suppresses smearing. It is useful as a multilayer printed circuit board using the above and a semiconductor device using the substrate.

Claims (7)

An epoxy resin composition containing the following components (A) to (E).
A smear inhibitor (A) component, which is one or more resins selected from the group consisting of (A) epoxy resin (B) active ester-based curing agent (C) alkoxyalkylated melamine resin and alkoxyalkylated phenol resin, (B). ) And 2 to 25% by mass based on the total amount of the component (D).
(D) A cyclic imide compound containing at least one dimer acid skeleton, at least one linear alkylene group having 6 or more carbon atoms, and at least two cyclic imide groups in the molecule.
7 to 70% by mass with respect to the total amount of the component (A), the component (B) and the component (D)
(E) Curing accelerator The epoxy resin composition according to claim 1, further containing an inorganic filler as the component (F). The epoxy resin composition according to claim 1 or 2, wherein the cyclic imide compound of the component (D) is represented by the following general formula (1).

(In the general formula (1), A independently represents a tetravalent organic group containing an aromatic ring or an aliphatic ring. B has an aliphatic ring having a divalent heteroatom and may contain a divalent heteroatom from 6 carbon atoms. It is an alkylene chain of 18. Q independently indicates a linear alkylene group having 6 or more carbon atoms. R independently indicates a linear or branched alkyl group having 6 or more carbon atoms. N indicates 1 to 10 Represents the number of. M represents the number of 0 to 10.) The epoxy resin composition according to claim 3, wherein A of the formula (1) is any one represented by the following structure.

(Note that the bond to which the substituent in the above structural formula is not bonded is one that bonds to the carbonyl carbon forming the cyclic imide structure in the general formula (1).) (E) The epoxy resin composition according to any one of claims 1 to 4, wherein the curing accelerator as a component is an anionic curing accelerator. A multilayer printed wiring board having an insulating layer formed of a cured product of the epoxy resin composition according to any one of claims 1 to 5. A semiconductor device having a cured product of the epoxy resin composition according to any one of claims 1 to 5.