JPH11279260A - Epoxy resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an epoxy resin composition with high heat resistance and storage stability, enabling the cost reduction and extreme thinning of multilayer printed boards, by compounding a phenoxy resin of a specific structure, an epoxy resin and a curing agent. SOLUTION: This epoxy resin composition comprises (A) a phenoxy resin of formula I [X is a group of formula II or formula III (R<1> and R<2> are each H, a 1-5C alkyl or the like; Y is SO, O or the like; (m) is 0 or 1), where the case that X is a group of formula III accounts for >=8% of the total X; (n) is >=21] with a molecular weight of 10,000-200,000, (B) an epoxy resin, and (C) a curing agent, wherein the component A accounts for 5-95 wt.% of the components A and B. The component A is prepared by direct reaction between a dihydric phenol such as bisphenol A and epichlorohydrin. The component B is pref. an aromatic epoxy resin with an epoxy equivalent of 150-2,000 g/eq. Furthermore, it is preferable to set that the respective halogen contents of the components A and B sum to 5-40 wt.%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is excellent in embedding in an inner layer circuit, excellent in adhesion to a circuit board, and excellent in smoothness of an outer layer circuit after lamination, and has an extremely thin plate thickness with almost no glass cloth. The present invention relates to an epoxy resin composition for a multilayer printed wiring board which is excellent in heat resistance and storage stability.

[0002]

2. Description of the Related Art Hitherto, a multilayer printed wiring board has been prepared by impregnating a glass cloth or a glass nonwoven fabric with an epoxy resin on an inner circuit board on which a circuit is formed, and then stacking a B-staged prepreg sheet, and further laying thereon. A manufacturing method of stacking copper foils and performing integral molding under pressure and heat is mainly employed. However, in this method, usually, first, a glass cloth or a glass nonwoven fabric is impregnated with an epoxy resin and B
The prepreg is prepared by making the prepreg into a stage, but the equipment required for the prepreg is expensive and has the disadvantage that the productivity of the prepreg is poor. Further, various facilities are required for stacking copper foils and integrally forming them under pressure and heat for multi-layering, and it takes a considerable amount of time to obtain a final product, which is problematic from the viewpoint of process economy. In addition, as a fundamental problem, there is a physical limit to the thickness of these materials from the viewpoint of maintaining the shape and strength of these materials in order to minimize the interlayer thickness because glass cloth or glass nonwoven fabric is used. It is pointed out that the thickness is a considerable value. The present invention addresses how to reduce this physical limit and contributes to improved process economy.

Japanese Patent Application Laid-Open No. 7-202418 describes a copper foil with an adhesive using a high-molecular epoxy resin, and the multilayer printed wiring board manufactured by the invention is a multilayer printed wiring board manufactured by a conventional technique. There is a drawback that heat resistance is inferior to printed wiring boards. The present invention contributes to the improvement of the heat resistance.

[0004]

DISCLOSURE OF THE INVENTION The present invention relates to an epoxy resin which can be reduced in cost and ultra-thin, and has high heat resistance and storage stability, which could not be achieved by the prior art. An object is to provide a resin composition.

[0005]

SUMMARY OF THE INVENTION The present invention provides a means for solving the problems of the prior art, which is represented by Formula 1 and has a molecular weight of 10,000 to 200,000 (gel permeation chromatography). (A weight average molecular weight in terms of standard polystyrene, measured by (GPC). Hereinafter, the molecular weight refers to the weight average molecular weight by this measurement method.) The component (A) is a phenoxy resin having an epoxy equivalent of 100 g / eq to 4 g. , 500 g / eq, comprising a component (B) which is an aromatic epoxy resin and a component (C) which is a curing agent, wherein the proportion of the component (A) is An epoxy resin composition having a thermosetting insulating layer-forming ability of 5% by weight to 95% by weight based on the total weight of the components, wherein the epoxy resin of the component (B) is from 100 g / eq. , An aromatic epoxy resin having an epoxy equivalent range of 500 g / eq, wherein the total of the halogen content in the component (A) and the halogen content in the component (B) is the same as that of the component (A) and the component (B). An epoxy resin composition characterized by being from 5% by weight to 40% by weight with respect to the total weight, and printed wiring characterized by applying the epoxy resin composition to a copper foil. It is a copper foil with a plate adhesive. This adhesive-coated copper foil is laminated on an inner circuit board and then thermally cured to form an extremely thin and heat-resistant multilayer printed wiring board.

[0006]

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In the formula, X is a compound represented by Formula 2 and Formula 3, wherein the proportion of X is Formula 3 is 8% or more of the total X, and n is a value of at least 21 or more. .

[0008]

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In the formula, R ¹ and R ^{2 each} represent a hydrogen atom, having 1 to 5 carbon atoms.
Are selected from alkyl groups and halogen atoms of
Y is any of —SO ₂ —, —CH ₂ —, —C (CH ₃ ) ₂ —, or —O—, and m is 0 or 1.
R ¹ and R ² may be the same or different.

[0010]

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The epoxy resin composition of the present invention, of course, satisfies various properties such as heat resistance, flame retardancy, and electrical insulation at least equivalent to those of a glass epoxy circuit board produced by a conventional technique. In addition, when applied to a copper foil, the copper foil does not curl after solvent volatilization and does not fall off during cutting, and when laminated on an inner circuit board, it has an inner layer circuit embedding property.

When the molecular weight of the component (A) is less than 10,000, the copper foil with the adhesive after the epoxy resin composition is applied to the copper foil and dried, causes curling of the copper foil and powder dropping during cutting. It becomes defective. When the molecular weight exceeds 200,000, the solution viscosity is too high at a concentration of 40% by weight to 70% by weight, which is generally used industrially, and even when diluted and dissolved with a solvent, the solution may be applied to a copper foil. Have difficulty. A large amount of an undesired solvent must be added in order to obtain a solution viscosity that can be applied to a copper foil, which is uneconomical and tends to reduce VOCs (volatile organic compounds) to the environment as much as possible. At present it is hard to say that it is preferable. Therefore, the molecular weight of the component (A) is preferably 11,000.
~ 100,000, more preferably 15,000 ~ 6
5,000.

Next, the applicable concentration range of the halogen content in the total amount of the components (A) and (B) will be described.
The halogen may be contained in at least one of the phenoxy resin of the component (A) and the epoxy resin of the component (B), but the halogen content of the components (A) and (B) is less than 5% by weight. Then, sufficient flame retardancy cannot be imparted to the epoxy resin composition of the present invention. At 5% by weight or more, flame retardancy can be imparted at any concentration.
Since no improvement in flame retardancy is observed even at a concentration of more than 5% by weight, it is practical to control the halogen content in the range of 5% by weight to 40% by weight. In the present invention, any kind of halogen element may be used, but from the viewpoint of commercial production, commercially available bromide, chlorinated and fluorinated compounds are preferably used.

As the method for producing the phenoxy resin as the component (A), a method by a direct reaction of dihydric phenol with epichlorohydrin and a method by an addition polymerization reaction of diglycidyl ether of dihydric phenol with dihydric phenol are known. The phenoxy resin used in the present invention may be based on any production method.

In the case of a direct reaction between a dihydric phenol and epichlorohydrin, the dihydric phenol is 9,9'-bis (4-hydroxyphenyl) fluorene and represented by Formula 4, for example, bisphenol A, bisphenol F, Examples include brominated bisphenol A, chlorinated bisphenol A, and fluorinated bisphenol A, but are not particularly limited thereto. They may be used alone or in combination of two or more. At this time,
9′-bis (4-hydroxyphenyl) fluorene is
It must be contained in an amount of at least 8 mol% of all dihydric phenols used. If the amount is less than 8 mol%, the effect of introducing the fluorene skeleton is not sufficient, and a cured film having heat resistance may not be obtained.

[0016]

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In the formula, R ¹ and R ² represent a hydrogen atom, a carbon number of 1 to
5 alkyl groups, those selected from halogen atoms, Y is _{-SO 2 -, - CH 2 -} , - C (CH 3) 2 -, or -O- is either, m is 0 or 1 Is the value of R ¹ and R ² may be the same or different.

In the case of a method based on an addition polymerization reaction of diglycidyl ether of dihydric phenol and dihydric phenol, diglycidyl ether of dihydric phenol represented by formula (5) and / or dihydric phenol represented by formula (6) The diglycidyl ether of the formula (1) is represented by 9,9′-bis (4-hydroxyphenyl) fluorene and / or formula 4 in the presence of a known catalyst such as an amine, imidazole, triphenylphosphine, and phosphonium salt. With the dihydric phenol used, 0.9: 1 to 1: 1, preferably 0.92: 1 to
0.99: 1, most preferably 0.95: 1 to 0.9
It is prepared by reacting in an amount to give a phenolic hydroxyl: epoxy ratio of 8: 1. At this time,
The total mol% of 9'-bis (4-hydroxyphenyl) fluorene and the diglycidyl ether of the dihydric phenol represented by Formula 6 is at least 8 mol% of the dihydric phenol used and the diglycidyl ether of the dihydric phenol. It is necessary to be. If it is less than 8 mol%, the effect of introducing a fluorene skeleton is not sufficient, and a cured film having heat resistance cannot be obtained, which is not preferable.

[0019]

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In the formula, R ¹ and R ² represent a hydrogen atom and a carbon number of 1 to
5 alkyl group or is any of halogen atom,, Y is _{-SO 2 -, - CH 2 -} , - C (CH 3) 2 -, or -O- is either, m is 0 or 1 And l is a value greater than 0. R ¹ and R ² may be the same or different.

[0021]

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Where l is a value greater than 0.

The phenoxy resin (component (A)) synthesized in this manner is a substance having heat resistance, flexibility and flame retardancy, but the resin alone during molding is small, and the circuit is embedded. In many cases, the sex is slightly insufficient. Therefore, it is necessary to add another epoxy resin and heat and cure it in order to have circuit embedding properties.

Next, the mixing ratio of the components (A) and (B) of the epoxy resin composition will be described. When the proportion of the component (A) in the total amount of the components (A) and (B) exceeds 95% by weight, the inner layer circuit embedding property when laminated on the inner layer circuit board is not obtained, which is not preferable. At a concentration of 40% by weight to 70% by weight, which is generally used industrially, the solution viscosity is too high, and it is difficult to apply the solution to a copper foil. In order to obtain a solution viscosity that can be applied to copper foil, a large amount of an undesirable solvent must be added, which is uneconomical.
At present, it is difficult to say that it is preferable to the environment in which VOCs (volatile organic compounds) are reduced as much as possible. When the content is less than 5% by weight, heat resistance when cured is insufficient, and the coating performance of the copper foil with an adhesive is deteriorated, and phenomena such as copper foil curl and powder dropping during cutting are observed. become. Therefore, the proportion of the component (A) in the total amount of the components (A) and (B) in the epoxy resin composition is preferably from 10% by weight to 91% by weight, more preferably 40% by weight.
% To 80% by weight.

The epoxy resin as the component (B) includes:
In order to have circuit embedding properties without deteriorating physical properties such as flexibility and heat resistance after curing, it is aromatic and has an epoxy equivalent of 1
It is preferably from 00 g / eq to 4,500 g / eq. If the epoxy equivalent exceeds 4,500 g / eq, sufficient circuit embedding properties cannot be obtained, and the crosslink density becomes low, so that a cured film having desirable heat resistance cannot be obtained. In addition, aliphatic epoxy resins have low heat resistance even though circuit embedding properties can be obtained. The epoxy equivalent is 100 g
If it is less than / eq, the crosslinked density of the cured product will be high, it will be hard and brittle, and the flexibility will be lost. For this reason, the epoxy equivalent of the component (B) is preferably 1
30 g / eq to 3,000 g / eq, more preferably 1 g / eq
It is 50 g / eq to 2,000 g / eq. Examples of epoxy resins suitable for the composition of the present invention include bisphenol A type epoxy resin, bisphenol F type epoxy resin, co-condensation type epoxy resin of bisphenol A and bisphenol F, novolak type epoxy resin, biphenyl type epoxy resin, dicyclopentadiene- Examples include phenolic co-condensation type epoxy resins and their halogen-substituted products, but are not particularly limited thereto. These epoxy resins may be used alone or in combination of two or more.

Various substances can be used as the curing agent of the component (C). For example, dicyandiamide and its derivatives, 2
Imidazoles such as -methylimidazole, 2-ethyl-4-methylimidazole and derivatives thereof, bisphenol A, bisphenol F, brominated bisphenol A,
Naphthalene diols, dihydric phenol compounds such as dihydroxybiphenyl, phenol, cresol, bisphenol A, naphthol, novolak type phenol resin obtained by condensation reaction of phenols such as naphthalene diol and aldehydes and ketones such as formaldehyde, phenol, Cresol, bisphenol A, phenolic compounds such as aralkyl-type phenolic resin obtained by condensation reaction of phenols such as naphthol and naphthalene diol with xylylene glycol, phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, anhydride Acid anhydrides such as maleic acid, hexahydrophthalic anhydride, diaminodiphenylmethane, triethylenetetramine, isophoronediamine, dimer acid and other acids and polyamines Amine compounds such polyamide amine obtained by the reaction or the like, adipic acid dihydrazide,
Examples of a commonly used curing agent for an epoxy resin, such as hydrazides such as isophthalic acid dihydrazide, include, but are not particularly limited to, these. These curing agents may be used alone or in combination of two or more.

The epoxy resin composition according to the present invention includes:
A solvent may be used in order to maintain an appropriate viscosity when applying to a copper foil. As the solvent for adjusting the viscosity, 100 ° C. to 1
It does not remain in the epoxy resin composition when the solvent is dried at 60 ° C., and specifically, toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, dioxane, ethanol, isopropyl alcohol, methyl cellosolve, ethyl cellosolve, cyclohexanone, etc. But are not particularly limited to these. These solvents may be used alone or in combination of two or more.

The epoxy resin composition of the present invention contains silica, calcium carbonate, talc, aluminum hydroxide, alumina, mica, etc. in order to impart heat resistance and flame retardancy and to reduce the coefficient of linear expansion. In order to improve the adhesive strength, an epoxy silane coupling agent or a rubber component may be added to such an extent that the physical properties of the cured epoxy resin composition are not deteriorated.

The epoxy resin composition of the present invention may contain a curing accelerator if necessary. For example, amines,
Various known curing accelerators such as imidazole, triphenylphosphine, and phosphonium salt can be used, but are not particularly limited thereto. When using a curing accelerator, 0.01% by weight of epoxy resin
A range of from 10 to 10% by weight is preferred. If it exceeds 10% by weight, the storage stability of the copper foil with the adhesive is deteriorated, which is not preferable.

The epoxy resin composition of the present invention is dissolved in the above-mentioned solvent in a solvent of 15,000 cps or less, preferably 10,000 cps or less.
Adjust to a viscosity of 0 cps or less, add an appropriate amount of a curing agent so as to have a certain curing time, and optionally add a curing accelerator to form a varnish, apply it to copper foil, and volatilize the solvent at 100 ° C to 160 ° C. Obtain copper foil with adhesive. By laminating the obtained copper foil with adhesive on the inner layer circuit board with a dry laminator or the like and curing by heating, a multilayer printed wiring board having an outer layer copper foil can be produced.

[0031]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be specifically described based on embodiments of the present invention. In the following Synthesis Examples, Examples and Comparative Examples, "parts" indicates "parts by weight".

[0032]

Synthesis Example 1 Bisphenol A type epoxy resin, specifically, YD-128 (manufactured by Toto Kasei, epoxy equivalent: 186.
56.9 parts of 5g / eq), a brominated bisphenol A type epoxy resin, specifically YDB-400 (manufactured by Toto Kasei, epoxy equivalent 398.4g / eq, softening point 70 ° C,
203.5 parts of bromine content (49.2%), 140.2 parts of 9,9′-bis (4-hydroxyphenyl) fluorene (manufactured by Adchemco, hydroxyl equivalent 175.2 g / eq),
171.7 parts of cyclohexanone, 2-ethyl 4-methylimidazole (Shikoku Chemicals, hereinafter 2E4MZ)
0.16 part) was charged into a four-necked glass separable flask equipped with a stirrer, thermometer, cooling tube, and nitrogen gas introducing device, and stirred for 10 hours while maintaining the reaction temperature at 145 ° C to 160 ° C. After that, 68.7 parts of cyclohexanone and 360.5 parts of methyl ethyl ketone were added, and the epoxy equivalent was 20,700 g / eq, the bromine content was 25.0%, the solid content concentration was 40.0% (hereinafter abbreviated as NV.), Viscosity 2,6
991 parts of a cyclohexanone / methyl ethyl ketone mixed varnish of a phenoxy resin having a weight average molecular weight of 38,800 at 00 cps / 25 ° C. was obtained. This resin was designated as synthetic resin varnish I.

[0033]

Synthesis Example 2 Bisphenol A type epoxy resin Specifically, 226.3 parts of YD-128 (described above), 208.8 parts of tetrabromobisphenol A, 14.4 parts of bisphenol A, 9,9'-bis 42.0 parts of (4-hydroxyphenyl) fluorene (described above), 175.5 parts of methyl isobutyl ketone, 0.29 part of triphenylphosphine (manufactured by Hokuko Chemical) as a catalyst, a stirrer, a thermometer, and a cooling pipe , Into a four-necked glass separable flask equipped with a nitrogen gas introduction device, and set the reaction temperature to 115 ° C.
After stirring at 125 ° C. for 10 hours, 226.6 parts of methyl isobutyl ketone was added, and the epoxy equivalent was 6,058 g.
/ Eq, bromine content 24.9%, NV. 55.0%, solution viscosity 3,520 cps / 25 ° C., weight average molecular weight 1
885 parts of 7,800 phenoxy resin methyl isobutyl ketone varnish were obtained. This resin is converted into a synthetic resin varnish I
I.

[0034]

Synthesis Example 3 Bisphenol A type epoxy resin, specifically 207.9 parts of YD-128 (described above), 9,9′-
191.5 parts of bis (4-hydroxyphenyl) fluorene (described above), 239.6 parts of cyclohexanone, 0.16 part of 2E4MZ (described above) as a catalyst, a stirrer, a thermometer, a cooling pipe, and a nitrogen gas introducing device were used. The reaction temperature was set to 145 ° C.
After stirring at 8 ° C. for 8 hours, 359.5 parts of methyl ethyl ketone was added, and the epoxy equivalent was 13,516 parts.
g / eq, bromine content 0%, NV. 40.0%, solution viscosity 5,000 cps / 25 ° C., weight average molecular weight 29.5
988 parts of a mixed varnish of cyclohexanone / methyl ethyl ketone of phenoxy resin No. 00 was obtained. This resin was used as synthetic resin varnish III.

[0035]

EXAMPLE 1 The synthetic resin varnish I obtained in Synthesis Example 1 was
50.0 parts and YD-128 as epoxy resin (described above)
10.00 parts, 0.56 parts of dicyandiamide (manufactured by Nippon Carbide, hereinafter abbreviated as DICY) as a hardening agent, 0.1 part of 2E4MZ (described above) as a hardening accelerator, 15. Eight parts were added and uniformly stirred and mixed to obtain an epoxy resin composition varnish. This varnish is applied to an anchor surface of a copper foil (manufactured by Mitsui Mining & Smelting) having a thickness of 35 μm using a roller coater so that the resin thickness after solvent drying is 60 μm, and the solvent is applied at 130 ° C. to 150 ° C. for 5 minutes to 15 minutes. Drying was performed to obtain a copper foil with an adhesive. On the other hand, a glass-epoxy-copper-clad double-sided laminated board having a copper blackening treatment with a pitch of 200 μm was used as a simulated inner-layer circuit board. The copper foil with the adhesive was laminated on both sides of this simulated inner layer circuit board with a dry laminator, and cured by heating at 180 ° C. for 2 hours.
A four-layer printed wiring board having an outer insulating layer thickness of 50 μm was obtained.

[0036]

Example 2 250.0 parts of synthetic resin varnish II obtained in Synthesis Example 1, 100.0 parts of YD-128 (described above) as an epoxy resin, and DICY (described above) as a curing agent.
63 parts, 2E4MZ as curing accelerator (described above) 0.3
Parts, and 158.4 parts of methylcellosolve, dimethylformamide, and methylethylketone as solvents were added and uniformly stirred and mixed to obtain a printed wiring board in exactly the same manner as in Example 1 except that an epoxy resin composition varnish was obtained.

[0037]

Example 3 The synthetic resin varnish I obtained in Synthesis Example 2 was replaced with 2
50.0 parts, 100.0 parts of YDB-400 (described above) as an epoxy resin and 800.0 parts of YD-014 (manufactured by Toto Kasei, epoxy equivalent: 954 g / eq, softening point: 98 ° C., bisphenol A type epoxy resin), cured DI as an agent
11.44 parts of CY (described above), 2E4M as a curing accelerator
Z (as described above), 1.5 parts of methylcellosolve, dimethylformamide, and 1,36
A printed wiring board was obtained in exactly the same manner as in Example 1, except that 8.1 parts were added and uniformly stirred and mixed to obtain an epoxy resin composition varnish.

[0038]

Example 4 The synthetic resin varnish I obtained in Synthesis Example 1 was replaced with 2
50.0 parts and YDCN-704 as epoxy resin (manufactured by Toto Kasei, epoxy equivalent 208 g / eq, softening point 92
° C, ortho-cresol novolak epoxy resin) 5
0.005, DICY (described above) 2.50 as a curing agent
Parts, 2E4MZ (described above) as a curing accelerator, 0.2 part, and methylcellosolve, dimethylformamide, methylethylketone, 78.8 parts as a solvent, and uniformly stirred and mixed.
A printed wiring board was obtained in exactly the same manner as in Example 1 except that an epoxy resin composition varnish was obtained.

[0039]

Example 5 Synthetic resin varnish III obtained in Synthesis Example 2
181.8 parts and YDCN-704 as an epoxy resin
25.00 parts (as described above), DICY as a curing agent (as described above)
1.25 parts, 2E4MZ (described above) as a curing accelerator
A printed wiring board was obtained in exactly the same manner as in Example 1 except that 1 part of a solvent and 26.3 parts of methylcellosolve, dimethylformamide and methylethylketone as a solvent were added and uniformly stirred and mixed to obtain an epoxy resin composition varnish.

[0040]

Example 6 Synthetic resin varnish III obtained in Synthesis Example 3
250.0 parts and YDB-400 as an epoxy resin.
25.00 parts (as described above), DICY as a curing agent (as described above)
0.66 parts, 2E4MZ (described above) as a curing accelerator
1 part, and 38.5 parts of methylcellosolve, dimethylformamide, and methylethylketone as solvents were added and uniformly stirred and mixed to obtain a printed wiring board in exactly the same manner as in Example 1 except that an epoxy resin composition varnish was obtained.

[0041]

Comparative Example 1 Synthetic resin varnish III obtained in Synthesis Example 3
250.0 parts and YDB-400 as an epoxy resin.
(Described above) 10.00 parts, DICY as a curing agent (described above)
0.26 parts, 2E4MZ (described above) as a curing accelerator
1 part, and 15.4 parts of methylcellosolve, dimethylformamide, and methylethylketone as solvents were added and uniformly stirred and mixed to obtain a printed wiring board in exactly the same manner as in Example 1 except that an epoxy resin composition varnish was obtained.

[0042]

Comparative Example 2 YPB-40AM40 (manufactured by Toto Kasei, epoxy equivalent 10,300 g / eq, bromine content 25.0)
%, Weight average molecular weight 30,300, cyclohexanone
Methyl ethyl ketone mixed varnish, NV. (40%, brominated phenoxy resin) 250.0 parts and Y as epoxy resin
D-128 (described above) 40.00 parts, DIC as a curing agent
2.25 parts of Y (described above), 2E4MZ as a curing accelerator
A printed wiring board was prepared in exactly the same manner as in Example 1 except that 0.2 part of the above and 63.4 parts of methylcellosolve, dimethylformamide, and methylethylketone as solvents were added and uniformly stirred and mixed to obtain an epoxy resin composition varnish. Obtained.

[0043]

Comparative Example 3 The synthetic resin varnish I obtained in Synthetic Example 1 was replaced with 2
50.0 parts and YD-128 as epoxy resin (described above)
4.00 parts, DICY (described above) 0.23 as a curing agent
Parts, 0.1 part of 2E4MZ (described above) as a curing accelerator, and 6.3 parts of methylcellosolve, dimethylformamide, and methylethylketone as solvents, and uniformly stirred and mixed to obtain an epoxy resin composition varnish. A printed wiring board was obtained in exactly the same manner.

[0044]

Comparative Example 4 The synthetic resin varnish I obtained in Synthetic Example 1 was replaced with 2
50.0 parts and YD-020 as an epoxy resin (manufactured by Toto Kasei, epoxy equivalent 4850 g / eq, softening point 143)
° C, bisphenol A type epoxy resin) 50.00 parts,
0.11 part of DICY (described above) as a curing agent, 0.1 part of 2E4MZ (described above) as a curing accelerator, and 91.1 parts of methylcellosolve, dimethylformamide, and methylethylketone as solvents, and uniformly stirred and mixed, and an epoxy resin composition was obtained. A printed wiring board was obtained in exactly the same manner as in Example 1 except that a varnish was obtained.

[0045]

Comparative Example 5 The synthetic resin varnish I obtained in Synthetic Example 1 was replaced with 2
50.0 parts and YD-128 as epoxy resin (described above)
10.00 parts, DICY (described above) 0.56 as a curing agent
Parts, 0.1 parts of 2E4MZ (described above) as a curing accelerator, and 181.0 parts of methylcellosolve, dimethylformamide, and methylethylketone as solvents were added and uniformly mixed with stirring to obtain an epoxy resin composition varnish. The varnish was impregnated into a glass cloth (manufactured by Nitto Boseki Co., Ltd.) having a thickness of 180 μm, and dried at a temperature of 130 to 150 ° C. for 5 to 15 minutes to obtain a prepreg. On the other hand, a glass-epoxy-copper-clad double-sided laminated board having a copper blackening treatment with a pitch of 200 μm was used as a simulated inner-layer circuit board. The prepreg sheet and the copper foil (described above) are stacked on both sides of the simulated inner layer circuit board in this order, and laminated with a dry laminator,
It is cured by heating at 180 ° C for 2 hours.
A 00 μm four-layer printed wiring board was obtained.

Table 1 shows the characteristic values of the multilayer printed wiring board prepared as described above. In Table 1,
The ratio of the component (A) in [(A) component + (B) component] is as follows:
It is the ratio for each solid content. Since the synthetic resin varnish contains a solvent, the varnish is a value represented by a ratio of a solid content excluding a solvent component.

[0047]

[Table 1]

(Test Method) Solder heat resistance test: A sample after boiling at 100 ° C. for 2 hours was immersed in a solder bath at 260 ° C. at n = 5, and all samples which did not swell or peel for 20 seconds or more were evaluated as ○. And Circuit embedding property: The resin embedded in the inner layer circuit after the outer layer copper foil was peeled was evaluated as ○. Glass transition temperature: heat-cured without laminating copper foil with adhesive, and peeled copper foil for TM
A measurement was performed. In the case of Comparative Example 5, the prepreg sheet was cured by heating and TMA was measured.

In Comparative Example 1, [Component (A) +
(B) component] has a bromine content of 4.4% by weight and 5% by weight.
Smaller than that, and the flame retardancy (UL-94) is V-1, indicating that the flame retardancy is not sufficient as compared with the examples. In Comparative Example 2, the content of the fluorene skeleton in the component (A) was zero, the glass transition point was as low as 115 ° C., the heat resistance was low, and the solder heat resistance was poor. That is, it indicates that the fluorene skeleton component in the component (A) is necessary for heat resistance, particularly for solder heat resistance. In Comparative Example 3,
When the ratio of the component (A) in the component (component (A) + component (B)) is 9
It exceeds 95% by weight at 6.2% by weight. in this case,
The circuit embedding property is poor. That is, in order to ensure the embedding property of the inner layer circuit when laminated on the inner layer circuit board, the ratio of the component (A) in [(A) component + (B) component] should not exceed 95% by weight. Indicates that there is a need. In Comparative Example 4, the component (B) having an epoxy equivalent of 4,850 g / eq was used. This is because the epoxy equivalent is higher than 4,500 g / eq, and both the solder heat resistance and the circuit embedding property are poor. The epoxy equivalent of the component (B) exceeding 4,500 g / eq indicates that it is not suitable as a resin for printed wiring boards. In Comparative Example 5, a conventionally used glass cloth was used. In this case, the thickness of the obtained printed wiring board is 200 μm. On the other hand, the thickness of the printed wiring board obtained by the present invention is about 50 μm as shown in Embodiment 1, and in the present invention, the thickness of the printed wiring board is made much thinner. You can do things.

As is clear from the examples and comparative examples, the use of the epoxy resin composition of the present invention ensures excellent heat resistance, particularly solder heat resistance, while ensuring flame retardancy.
It is excellent in the embedding property of the inner layer circuit when laminated on the inner layer circuit board, and the thickness of the printed wiring board can be remarkably reduced.

[0051]

The use of the epoxy resin composition according to the present invention makes it possible to prepare a prepreg using a glass cloth or a glass non-woven fabric, and to laminate a copper foil with an adhesive simply by laminating a copper foil with an adhesive. Certain multilayer printed wiring boards can be made, which simplifies the manufacturing process and thus improves process economics. Further, since a glass cloth or a nonwoven fabric is not used, an extremely thin and lightweight multilayer printed wiring board can be produced. Furthermore,
Flame retardancy is provided.

Claims (3)

[Claims] A component (A) which is a phenoxy resin represented by Formula 1 and having a molecular weight of 10,000 to 200,000,
A composition comprising the component (B) which is an epoxy resin and the component (C) which is a curing agent, wherein the proportion of the component (A) is based on the total weight of the components (A) and (B). An epoxy resin composition having a thermosetting insulating layer forming ability of 5% by weight to 95% by weight. Embedded image In the formula, X is a compound represented by Formula 2 and Formula 3,
The proportion of X being Formula 3 is 8% or more of the total X, and n is a value of at least 21 or more. Embedded image In the formula, R ¹ and R ² are selected from a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, and a halogen atom, and Y is —SO
_{2 -, - CH 2 -,} - C (CH 3) 2 -, or -O- is either, m is a value of 0 or 1. Embedded image 2. The amount of the epoxy resin (B) is 100 g /
It is an aromatic epoxy resin having an epoxy equivalent range of eq to 4,500 g / eq, wherein the sum of the halogen content in the component (A) and the halogen content in the component (B) is (A) and (B) 2. The epoxy resin composition according to claim 1, wherein the amount is from 5% by weight to 40% by weight based on the total weight of the component). 3. An epoxy resin composition according to claim 1, which is applied to a copper foil.
Copper foil with adhesive for printed wiring boards.