JPWO2007097209A1 - Epoxy resin composition - Google Patents

Abstract

An epoxy resin composition suitable for use as an insulating layer of a multilayer printed wiring board, which can achieve sufficient flame retardancy regardless of halogen flame retardants and phosphorus flame retardants, storage stability and An epoxy resin composition having excellent adhesion strength of an insulating layer to a plated conductor is provided. (A) An aromatic epoxy resin having two or more epoxy groups in one molecule, (B) a naphthol-based curing agent, (C) a thioalkyl group-containing phenol-based curing agent, and (D) an inorganic filler. An epoxy resin composition characterized by that.

Description

  The present invention relates to an epoxy resin composition, and more particularly to an epoxy resin composition suitable for forming an insulating layer of a multilayer printed wiring board.

  In recent years, electronic devices have become smaller and higher in performance, and the miniaturization and higher density of wiring have also been advanced in multilayer printed wiring boards. Conductive layer formation methods suitable for forming high-density wiring include the additive method of forming a conductive layer by electroless plating after roughening the surface of the insulating layer, and forming the conductive layer by electroless plating and electrolytic plating. A semi-additive method is known. Therefore, the epoxy resin composition used for forming the insulating layer of the multilayer printed wiring board is also required to have high adhesion with the plated conductor layer.

On the other hand, halogen-based compounds such as brominated epoxy resins have been conventionally used for flame retardant epoxy resin compositions, but their use is becoming difficult due to environmental problems such as dioxins in recent years. In the epoxy resin composition for multilayer printed wiring boards, as a flame retardant technique not using a halogen compound, for example, as seen in Patent Document 1, Patent Document 2, etc., a method using a reactive phosphorus flame retardant It has been known. Patent Document 3 discloses a method of using a phenol resin having a thioalkyl group as a curing agent in a semiconductor sealing resin composition.
JP 2001-214037 A Japanese Patent No. 3108212 JP 2004-339277 A

  However, the use of phosphorus-based flame retardants is also being suppressed due to environmental problems. Further, according to the knowledge of the present inventor, the thioalkyl group-containing phenol resin tends to reduce the storage stability of the resin composition. Furthermore, according to the knowledge of the present inventor, the flame retarding effect of the thioalkyl group-containing phenol resin is not always sufficient. For example, as in Patent Document 3, the content of an inorganic filler such as silica is 70 to 95% by mass. In the epoxy resin composition for multilayer printed wiring boards, the content of which is relatively smaller than that of the semiconductor sealing epoxy resin composition, the reduction in flame retardancy becomes a significant problem.

  The present invention has been made in view of the circumstances as described above, and the problem to be solved is an epoxy resin composition suitable for use as an insulating layer of a multilayer printed wiring board, comprising a halogen-based flame retardant and An object of the present invention is to provide an epoxy resin composition that can achieve sufficient flame retardancy without using a phosphorus-based flame retardant, and is excellent in storage stability and adhesion strength of an insulating layer (interlayer insulating layer) to a plated conductor.

  As a result of diligent research to solve the above problems, the present invention has (A) an aromatic epoxy resin having two or more epoxy groups in one molecule, (B) a naphthol curing agent, and (C) a thioalkyl group. The epoxy resin composition characterized by containing a phenolic curing agent and (D) an inorganic filler is excellent in flame retardancy, storage stability and adhesion strength of an insulating layer (interlayer insulating layer) to a plated conductor. The headline and the present invention were completed.

That is, the present invention includes the following contents.
[1] (A) an aromatic epoxy resin having two or more epoxy groups in one molecule, (B) a naphthol curing agent, (C) a thioalkyl group-containing phenol curing agent, and (D) an inorganic filler, An epoxy resin composition comprising:
[2] The epoxy resin composition according to the above [1], which contains 20 to 60% by mass of the inorganic filler of component (D) when the nonvolatile component of the epoxy resin composition is 100% by mass.
[3] The epoxy resin composition according to the above [1], containing 30 to 50% by mass of the inorganic filler of component (D) when the nonvolatile component of the epoxy resin composition is 100% by mass.
[4] The epoxy resin composition according to any one of the above [1] to [3], wherein the inorganic filler of component (D) is silica.
[5] The epoxy resin composition according to any one of the above [1] to [4], wherein the blending ratio of the components (B) and (C) is 1: 0.1 to 1: 1.5 by mass ratio. .
[6] The naphthol curing agent of component (B) is represented by the following formula (1):

(Wherein R1 to R4 each independently represents a hydrogen atom or an alkyl group, X1 represents a naphthalene ring which may be substituted with an alkyl group, and Y may each be substituted with an alkyl group. A benzene ring, a hydroxybenzene ring, a biphenyl ring or a naphthalene ring, and j and k each represent an average value of 1 to 15.)
The thioalkyl group-containing phenolic curing agent of component (C) is represented by the following formula (2):

(In the formula, R5 represents a hydrogen atom or an alkyl group, R6 represents a thioalkyl group, X2 represents a benzene ring or a naphthalene ring each optionally substituted with an alkyl group, and j and k each represent an average value of 1; ) Represents a number of -15, and m represents an integer of 1-5.
The epoxy resin composition according to any one of the above [1] to [5], which is a thioalkyl group-containing phenolic curing agent represented by the formula:
[7] The naphthol curing agent of component (B) is represented by the following formula (1 ′):

(Wherein R1 to R4 each independently represents a hydrogen atom or an alkyl group, X1 represents a naphthalene ring which may be substituted with an alkyl group, and Y may each be substituted with an alkyl group. , A benzene ring, a hydroxybenzene ring, a biphenyl ring or a naphthalene ring, and n represents an average value of 1 to 15.)
And a thioalkyl group-containing phenolic curing agent of component (C) is represented by the following formula (2 ′):

(In the formula, R5 represents a hydrogen atom or an alkyl group, R6 represents a thioalkyl group, X2 represents a benzene ring or a naphthalene ring each optionally substituted with an alkyl group, and n represents an average value of 1 to 15. And m represents an integer of 1 to 5.)
The epoxy resin composition according to any one of the above [1] to [5], which is a thioalkyl group-containing phenolic curing agent represented by the formula:
[8] The first epoxy resin, wherein the aromatic epoxy resin of component (A) is (A1) an aromatic epoxy resin that has two or more epoxy groups in one molecule and is liquid at a temperature of 20 ° C. And (A2) any one of the above [1] to [7], which contains a second epoxy resin that has 3 or more epoxy groups in one molecule and is a solid aromatic epoxy resin at a temperature of 20 ° C. An epoxy resin composition according to claim 1.
[9] The epoxy resin composition according to the above [8], wherein the epoxy equivalent of the second epoxy resin of the component (A2) is 230 or less.
[10] The epoxy resin composition according to the above [8], wherein the epoxy equivalent of the second epoxy resin of the component (A2) is in the range of 150 to 230.
[11] The above [8], wherein the blending ratio (A1: A2) of the first epoxy resin (A1) and the second epoxy resin (A2) is in the range of 1: 0.3 to 1: 2 by mass ratio. ] The epoxy resin composition in any one of [10].
[12] When the nonvolatile component of the epoxy resin composition is 100% by mass, the content of the aromatic epoxy resin of the component (A) is 10 to 50% by mass, and the epoxy group present in the epoxy resin composition The ratio of the phenolic hydroxyl group of the naphthol-based curing agent of component (B) and the thioalkyl group-containing phenol-based curing agent of component (C) to 1: 0.5 to 1: 1.5 is [1] to [11] The epoxy resin composition according to any one of the above.
[13] The epoxy resin composition according to any one of the above [1] to [12], wherein the epoxy resin composition further contains a polyvinyl acetal resin.
[14] The epoxy resin composition according to the above [13], wherein the content of the polyvinyl acetal resin is 2 to 20% by mass when the nonvolatile component of the epoxy resin composition is 100% by mass.
[15] An adhesive film in which the epoxy resin composition according to any one of [1] to [14] is layered on a support film.
[16] A prepreg in which the epoxy resin composition according to any one of [1] to [14] is impregnated in a sheet-like reinforcing base material made of fibers.
[17] A multilayer printed wiring board in which an insulating layer is formed of a cured product of the epoxy resin composition according to any one of [1] to [14].
[18] A method for producing a multilayer printed wiring board, comprising a step of forming an insulating layer on an inner layer circuit board and a step of forming a conductor layer on the insulating layer, wherein the insulating layer comprises the above [1] to [ 14] A multilayer which is formed by thermosetting the epoxy resin composition according to any one of the above, and the conductor layer is formed by copper plating on a roughened surface obtained by roughening the surface of the insulating layer. Manufacturing method of printed wiring board.
[19] A method for producing a multilayer printed wiring board, comprising a step of forming an insulating layer on an inner circuit board and a step of forming a conductor layer on the insulating layer, wherein the insulating layer is an adhesive according to the above [15] The conductor layer is formed by laminating a film on an inner circuit board and thermally curing the epoxy resin composition with or without peeling the support film, and peeling the support film when a support film is present after curing. Is formed by copper plating on a roughened surface obtained by roughening the surface of the insulating layer.
[20] A method for producing a multilayer printed wiring board, comprising a step of forming an insulating layer on an inner circuit board and a step of forming a conductor layer on the insulating layer, wherein the insulating layer is a prepreg according to the above [16] The conductive layer is formed by copper plating on the roughened surface obtained by roughening the surface of the insulating layer. The manufacturing method of a multilayer printed wiring board.

  According to the present invention, an insulating layer that can achieve sufficient flame retardancy without depending on a halogen-based flame retardant and a phosphorus-based flame retardant, has excellent storage stability, and has excellent adhesion strength with a conductor layer formed by plating. An epoxy resin composition that can be formed can be provided.

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

[Epoxy resin of component (A)]
The “aromatic epoxy resin having two or more epoxy groups in one molecule” of the component (A) in the present invention is not particularly limited, and examples thereof include cresol novolac epoxy resins, phenol novolac epoxy resins, and tert- Examples thereof include butyl-catechol type epoxy resin, biphenyl type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, naphthalene type epoxy resin, glycidylamine type epoxy resin and the like. Those containing a halogen atom are not preferred. The aromatic epoxy resin in the present invention means an epoxy resin having an aromatic ring skeleton in the molecule.

  The component (A) epoxy resin may be used alone or in combination of two or more. However, “(A1) one molecule has two or more epoxy groups and is liquid at a temperature of 20 ° C. The first epoxy resin ”and“ (A2) a second aromatic epoxy resin having 3 or more epoxy groups in one molecule and a solid aromatic epoxy resin at a temperature of 20 ° C. ” A mode in which an “epoxy resin” is used in combination is preferred. As the second epoxy resin, an epoxy equivalent of 230 or less is more preferable, and an epoxy equivalent of 150 to 230 is particularly preferable.

  By using the first epoxy resin (A1) and the second epoxy resin (A2) as the epoxy resin (A), sufficient flexibility can be obtained when the resin composition is used in the form of an adhesive film. The adhesive film shown (excellent in handleability) can be formed, and at the same time, the breaking strength of the cured product of the resin composition is improved, and the durability of the multilayer printed wiring board is improved.

  In the present invention, “(A1) a first epoxy resin which is an aromatic epoxy resin having two or more epoxy groups in one molecule and liquid at a temperature of 20 ° C.” includes a bisphenol A type epoxy resin, Examples thereof include bisphenol F type epoxy resin, phenol novolak type epoxy resin, tert-butyl-catechol type epoxy resin, naphthalene type epoxy resin, glycidylamine type epoxy resin and the like. In the present invention, the first epoxy resin (A1) may be used alone or in combination of two or more. Moreover, the said 1st epoxy resin (A1) may be liquefied at the temperature below 20 degreeC.

  Specific examples of such epoxy resins include HP4032 (manufactured by Dainippon Ink and Chemicals), HP4032D (manufactured by Dainippon Ink and Chemicals), jER807 (Epicoat 807) (Japan Epoxy Resin Co., Ltd.) )), JER828EL (Epicoat 828EL) (manufactured by Japan Epoxy Resin Co., Ltd.), jER152 (Epicoat 152) (manufactured by Japan Epoxy Resin Co., Ltd.), and the like.

  On the other hand, (A2) “second epoxy resin that has 3 or more epoxy groups in one molecule and is a solid aromatic epoxy resin at a temperature of 20 ° C.” includes, for example, naphthalene type epoxy resins and phenols And an epoxidized product (trisphenol type epoxy resin) of a condensate of an aromatic aldehyde having a phenolic hydroxyl group and the like. In addition, the second epoxy resin (A2) preferably has an epoxy equivalent of 230 or less, and further has an epoxy equivalent in the range of 150 to 230 in order to improve physical properties such as the glass transition temperature of the resin composition. preferable. Therefore, in the present invention, the second epoxy resin (A2) is “a liquid aromatic epoxy having 3 or more epoxy groups in one molecule and having an epoxy equivalent of 230 or less and a temperature of 20 ° C. It is preferably “resin”, more preferably “aromatic epoxy resin having 3 or more epoxy groups in one molecule, epoxy equivalent of 150 to 230, and solid at 20 ° C.” . The second epoxy resin (A2) may be used alone or in combination of two or more. The second epoxy resin (A2) may be solid at a temperature exceeding 20 ° C.

  Specifically, as such an epoxy resin, HP4700 (EXA4700) (tetrafunctional naphthalene type epoxy resin, epoxy equivalent 163, solid) manufactured by Dainippon Ink and Chemicals, Inc., N-690 (cresol novolac epoxy resin) , Epoxy equivalent 208, solid), N-695 (cresol novolak epoxy resin, epoxy equivalent 208, solid), Nippon Kayaku's EPPN-502H (trisphenol epoxy resin, epoxy equivalent 168, solid), NC7000L (naphthol) Novolac epoxy resin, epoxy equivalent 228, solid), NC3000H (biphenyl type epoxy resin, epoxy equivalent 290, solid), ESN185 manufactured by Tohto Kasei Co., Ltd. (naphthol novolac type epoxy resin, epoxy equivalent 275, solid), ESN475 (solid) Off tall novolak type epoxy resin, epoxy equivalent 350, solid), and the like.

  Moreover, when using together 1st epoxy resin (A1) and 2nd epoxy resin (A2) as an epoxy resin (A), the combination of 1st epoxy resin (A1) and 2nd epoxy resin (A2) The ratio (A1: A2) is preferably in the range of 1: 0.3 to 2 and more preferably in the range of 1: 0.5 to 1 in terms of mass ratio. If the ratio of the first epoxy resin (A1) is too large beyond this range, the adhesiveness of the resin composition increases, and when used in the form of an adhesive film, the deaeration during vacuum lamination decreases and voids. Tends to occur. Moreover, there exists a tendency for the peelability of a protective film and a support film to fall at the time of vacuum lamination, and the heat resistance after hardening to fall. Moreover, it exists in the tendency for sufficient breaking strength to be hard to be obtained in the hardened | cured material of a resin composition. On the other hand, if the ratio of the second epoxy resin (A2) is too large beyond this range, sufficient flexibility cannot be obtained when the adhesive film is used in the form of an adhesive film, and the handleability is lowered. There is a tendency that it is difficult to obtain sufficient fluidity.

  In the epoxy resin composition of the present invention, when the nonvolatile component of the epoxy resin composition is 100% by mass, the epoxy resin content of the component (A) is preferably 10 to 50% by mass, more preferably 20 to 20% by mass. It is 40 mass%, Most preferably, it is 20-35 mass%. When the content of the epoxy resin (A) is out of this range, the curability of the resin composition tends to decrease. Further, the epoxy resin composition of the present invention is within the range in which the effects of the present invention are exhibited (usually 50% by mass or less when the nonvolatile component of the epoxy resin composition is 100% by mass), except for the component (A) Other epoxy resins may be included.

[Naphthol curing agent of component (B)]
The “naphthol curing agent” in the present invention means a compound having two or more naphthol structures in one molecule and acting as a curing agent for the epoxy resin (A).

  As the naphthol-based curing agent, a naphthol-based curing agent represented by the following formula (1) is preferable, and a naphthol-based curing agent represented by the following formula (1 ′) is particularly preferable.

(Wherein R1 to R4 each independently represents a hydrogen atom or an alkyl group, X1 represents a naphthalene ring which may be substituted with an alkyl group, and Y may each be substituted with an alkyl group. A benzene ring, a hydroxybenzene ring, a biphenyl ring or a naphthalene ring, and j and k each represent an average value of 1 to 15.)

(Wherein R1 to R4 each independently represents a hydrogen atom or an alkyl group, X1 represents a naphthalene ring which may be substituted with an alkyl group, and Y may each be substituted with an alkyl group. , A benzene ring, a hydroxybenzene ring, a biphenyl ring or a naphthalene ring, and n represents an average value of 1 to 15.)

  In formula (1) and formula (1 '), the alkyl group in the formula is preferably an alkyl group having 1 to 3 carbon atoms, and particularly preferably a methyl group.

[Component (C) thioalkyl group-containing phenolic curing agent]
The “thioalkyl group-containing phenolic curing agent” in the present invention has one or more thioalkyl groups in one molecule and one or more phenol and / or naphthol structures in one molecule, and is used as a curing agent for the epoxy resin (A). It means a compound that acts.

  As the thioalkyl group-containing phenolic curing agent, a thioalkyl group-containing phenolic curing agent represented by the following formula (2) is preferable, and a thioalkyl group-containing phenolic curing agent represented by the following formula (2 ′) is particularly preferable. .

(In the formula, R5 represents a hydrogen atom or an alkyl group, R6 represents a thioalkyl group, X2 represents a benzene ring or a naphthalene ring each optionally substituted with an alkyl group, and j and k each represent an average value of 1; ) Represents a number of -15, and m represents an integer of 1-5.

(In the formula, R5 represents a hydrogen atom or an alkyl group, R6 represents a thioalkyl group, X2 represents a benzene ring or a naphthalene ring each optionally substituted with an alkyl group, and n represents an average value of 1 to 15. And m represents an integer of 1 to 5.)

  In formulas (2) and (2 ′), when m is 2 to 5, the plurality of R6 need not be the same and are each independently selected from a hydrogen atom, an alkyl group, or a thioalkyl group. It may be a group. Moreover, as an alkyl group, a C1-C3 alkyl group is preferable, and especially a methyl group is preferable. Moreover, as a thioalkyl group, a C1-C3 alkyl group is preferable, and especially a thiomethyl group is preferable.

  In the present invention, the average hydroxyl group content P ((total number of hydroxyl groups / total benzene) in one molecule as represented by the above formula (1), formula (1 ′), formula (2) and formula (2 ′). By employing a phenolic curing agent in which the average value of the ring number) is 0 <P <1, the roughened surface obtained by roughening the cured product of the epoxy resin composition of the present invention becomes finer. In addition, it can be made more suitable for high density wiring.

  In addition, as a naphthol type hardening | curing agent of a component (B), what is represented by the following Formula (3) is more preferable.

(In the formula, R7 represents a hydrogen atom or a methyl group, Z represents a naphthalene ring, and n represents an average value of 1 to 15)

  Specific examples of the naphthol-based curing agent represented by the formula (3) include NHN (Z: naphthalene ring, R7: methyl group, average hydroxyl group content: 3/5 to 2/3, manufactured by Nippon Kayaku Co., Ltd. And CBN (Z: naphthalene ring, R7: methyl group, average hydroxyl group content: 3/5 to 2/3, see lower diagram) and the like.

  Moreover, as a thioalkyl group containing phenol type hardening | curing agent of a component (C), what is represented by the following Formula (4) is more preferable.

(In the formula, R11 represents a thiomethyl group, and n represents an average value of 1 to 15)
Specific examples of the thioalkyl group-containing phenolic curing agent represented by the formula (4) include YLH1110L (average hydroxyl group content: 1/2 to 2/3) manufactured by Japan Epoxy Resin Co., Ltd.

  The blending ratio of the components (B) and (C) is preferably in the range of 1: 0.1 to 1: 1.5 by mass ratio, and is preferably in the range of 1: 0.1 to 1: 1. Further preferred. If the proportion of the thioalkyl group-containing phenolic curing agent of component (C) is too small, the adhesion between the insulating layer formed by the epoxy resin composition and the plated conductor layer tends to decrease. Storage stability tends to decrease.

  You may mix | blend the phenol-type hardener other than a component (B) and a component (C) with the epoxy resin composition of this invention. In this case, it is preferable that 50% by mass or more of the total phenolic curing agent in the composition is the component (B) and the component (C), more preferably 70, in order to sufficiently exhibit the effects of the present invention. The component (B) and the component (C) are preferably contained in an amount of at least 90% by mass, particularly 90% by mass.

  In the present invention, the amount of the phenolic curing agent in the epoxy resin composition (the total amount when only the component (B) and the component (C) are used, or other than the component (B) and the component (C) The total amount of these when used in combination with the phenolic curing agent) is usually the ratio of the total number of epoxy groups present in the epoxy resin composition to the total number of phenolic hydroxyl groups of the phenolic curing agent is 1: 0. It is preferable that the amount is 1 to 1: 1.5, and it is more preferable that the ratio is 1: 0.3 to 1: 1. The total number of epoxy groups present in the epoxy resin composition is a value obtained by dividing the solid content mass of each epoxy resin by the epoxy equivalent for all epoxy resins, and the phenolic curing agent phenolic The total number of hydroxyl groups is the total value of all phenolic curing agents obtained by dividing the solid content mass of each phenolic curing agent by its phenolic hydroxyl group equivalent. If the content of the phenolic curing agent is out of the preferable range, the heat resistance of the cured product obtained by curing the resin composition may be insufficient.

  In the present invention, the inorganic filler of component (D) contributes to lowering the thermal expansion coefficient at the same time as enhancing the flame retardancy of the epoxy resin composition. Examples of the inorganic filler include silica, alumina, barium sulfate, talc, clay, mica powder, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, magnesium oxide, boron nitride, aluminum borate, barium titanate, Examples include strontium titanate, calcium titanate, magnesium titanate, bismuth titanate, titanium oxide, barium zirconate, and calcium zirconate. Among these, silica is particularly suitable. The average particle size of the inorganic filler is preferably 1 μm or less, more preferably 0.8 μm or less, and particularly preferably 0.7 μm or less. When the average particle size exceeds 1 μm, it tends to be disadvantageous for the formation of fine wiring. If the average particle size of the inorganic filler is too small, when the epoxy resin composition is used as a resin varnish, the viscosity of the varnish tends to increase and the handleability tends to decrease. It is preferable that it is 05 μm or more. The inorganic filler is preferably surface-treated with a surface treatment agent such as a silane coupling agent in order to improve moisture resistance.

  The average particle diameter of the inorganic filler can be measured by a laser diffraction / scattering method based on Mie scattering theory. Specifically, the particle size distribution of the inorganic filler can be created on a volume basis by a laser diffraction particle size distribution measuring device, and the median diameter can be measured as the average particle diameter. As the measurement sample, an inorganic filler dispersed in water by ultrasonic waves can be preferably used. As a laser diffraction type particle size distribution measuring apparatus, LA-500 manufactured by Horiba Ltd. can be used.

  When the inorganic filler is blended, the content ratio with respect to the resin composition (non-volatile content: 100% by mass) varies depending on the properties required for the resin composition, but when used for forming an interlayer insulating layer of a multilayer printed wiring board. It is preferably 20 to 60% by mass, more preferably 25 to 50% by mass, and particularly preferably 30 to 45% by mass. When there is too much compounding quantity of an inorganic filler, there exists a tendency for the adhesive strength of an insulating layer and a plating conductor layer to fall, and the hardened | cured material of an epoxy resin composition to become weak. On the other hand, when there are too few compounding quantities, there exists a tendency for the flame retardance fall of hardened | cured material and a thermal expansion coefficient to increase.

  The epoxy resin composition of the present invention may contain a polyvinyl acetal resin for the purpose of increasing the adhesion strength of the plated conductor. Although it does not specifically limit as a polyvinyl acetal resin, A polyvinyl butyral resin is preferable. Specific examples of the polyvinyl acetal resin include those manufactured by Denki Kagaku Kogyo Co., Ltd., electrified butyral 4000-2, 5000-A, 6000-C, 6000-EP, and Sekisui Chemical Co., Ltd., ESREC BH series, BX series, and KS. Series, BL series, BM series and the like.

  The polyvinyl acetal having a glass transition temperature of 80 ° C. or higher is particularly preferable. The “glass transition temperature” here is determined according to the method described in JIS K7197. When the glass transition temperature is higher than the decomposition temperature and the glass transition temperature is not actually observed, the decomposition temperature can be regarded as the glass transition temperature in the present invention. The decomposition temperature is defined as the temperature at which the mass reduction rate is 5% when measured according to the method described in JIS K 7120.

  In the epoxy resin composition of the present invention, when the nonvolatile component of the epoxy resin composition is 100% by mass, the content of polyvinyl acetal is preferably 2 to 20% by mass.

  The epoxy resin composition of the present invention may contain a phenoxy resin for the purpose of improving the flexibility of the adhesive film. It does not specifically limit as a phenoxy resin, A well-known phenoxy resin etc. can be used. When the nonvolatile component of the epoxy resin composition is 100% by mass, the content ratio of the phenoxy resin is preferably in the range of 3 to 30% by mass. Specific examples of the phenoxy resin include FX280, FX293 manufactured by Toto Kasei Co., Ltd., YX8100, YL6954, YL6974 manufactured by Japan Epoxy Resin Co., Ltd., and the like.

  The epoxy resin composition of the present invention may contain rubber particles for the purpose of increasing the mechanical strength of the cured product. Preferable examples of the rubber particles include core-shell type rubber particles, crosslinked acrylonitrile butadiene rubber particles, crosslinked styrene butadiene rubber particles, acrylic rubber particles and the like. The core-shell type rubber particles are rubber particles having a core layer and a shell layer. For example, the outer shell layer is a glassy polymer and the inner core layer is a rubbery polymer. Examples include a three-layer structure in which the shell layer is a glassy polymer, the intermediate layer is a rubbery polymer, and the core layer is a glassy polymer. The glass layer is made of, for example, a polymer of methyl methacrylate, and the rubbery polymer layer is made of, for example, a butyl acrylate polymer (butyl rubber). Specific examples of the core-shell type rubber particles include Staphyloid AC3832, AC3816N, (Ganz Kasei Co., Ltd. trade name), and Metabrene KW-4426 (Mitsubishi Rayon Co., Ltd. trade name). Specific examples of the acrylonitrile butadiene rubber (NBR) particles include XER-91 (average particle size 0.5 μm, manufactured by JSR Corporation). Specific examples of the styrene butadiene rubber (SBR) particles include XSK-500 (average particle size 0.5 μm, manufactured by JSR Corporation). Specific examples of the acrylic rubber particles include Methbrene W300A (average particle size 0.1 μm) and W450A (average particle size 0.2 μm) (manufactured by Mitsubishi Rayon Co., Ltd.).

  When the rubber particles are blended, the content ratio with respect to the resin composition (non-volatile content: 100% by mass) varies depending on the properties required for the resin composition, but is preferably 1 to 10% by mass, 2 to 5% by mass is more preferable.

  The epoxy resin composition of the present invention may contain a curing accelerator for the purpose of adjusting the curing time. Examples of the curing accelerator include organic phosphine compounds, imidazole compounds, amine adduct compounds, and tertiary amine compounds. Specific examples of the organic phosphine compound include TPP, TPP-K, TPP-S, and TPTP-S (trade name of Hokuko Chemical Co., Ltd.). Specific examples of the imidazole compound include Curazole 2MZ, 2E4MZ, C11Z, C11Z-CN, C11Z-CNS, C11Z-A, 2MZ-OK, 2MA-OK, 2PHZ (trade names of Shikoku Kasei Kogyo Co., Ltd.). . Specific examples of the amine adduct compound include Novacure (trade name of Asahi Kasei Kogyo Co., Ltd.) and Fuji Cure (trade name of Fuji Kasei Kogyo Co., Ltd.). Specific examples of the tertiary amine compound include DBU (1,8-diazabicyclo [5,4,0] undec-7-ene). In the epoxy resin composition of the present invention, the content of the curing accelerator is usually 0.1 when the total amount of the epoxy resin and the phenolic curing agent contained in the epoxy resin composition is 100% by mass (solid content). Used in the range of ˜5% by mass.

  The epoxy resin composition of the present invention may contain a flame retardant as long as the effects of the present invention are exhibited. However, halogen-based flame retardants are becoming difficult to use due to environmental problems such as dioxins in recent years, and phosphorus-based flame retardants are being suppressed due to environmental impacts. Is not contained, or it is preferred that it be contained in as little as possible. Since the epoxy resin composition of the present invention can achieve sufficient flame retardancy without containing a halogen element and a phosphorus element, it can be an epoxy resin composition that is excellent in terms of environment.

  The epoxy resin composition of the present invention may contain other resin additives other than those described above as long as the effects of the present invention are exhibited. Examples of the resin additive include organic fillers such as silicon powder, nylon powder, and fluorine powder, thickeners such as olben and benton, silicone-based, fluorine-based, polymer-based antifoaming agents or leveling agents, imidazole-based, Examples thereof include adhesion imparting agents such as thiazole-based, triazole-based, and silane coupling agents, and coloring pigments.

  The epoxy resin composition of the present invention is applied on a support film to form a resin composition layer to form an adhesive film for a multilayer printed wiring board, or the resin composition in a sheet-like reinforcing substrate made of fibers. Can be made into a prepreg for an interlayer insulating layer of a multilayer printed wiring board. The epoxy resin composition of the present invention can be applied to a circuit board to form an insulating layer, but industrially, it is generally used for forming an insulating layer in the form of an adhesive film or a prepreg.

  The adhesive film of the present invention is prepared by a method known to those skilled in the art, for example, by preparing a resin varnish in which a resin composition is dissolved in an organic solvent, applying the resin varnish using the support film as a support, and further heating or hot air. The organic solvent can be dried by spraying or the like to form a resin composition layer.

  Examples of the organic solvent include ketones such as acetone, methyl ethyl ketone and cyclohexanone, acetates such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate and carbitol acetate, and carbitols such as cellosolve and butyl carbitol. And aromatic hydrocarbons such as toluene and xylene, dimethylformamide, dimethylacetamide, N-methylpyrrolidone and the like. Two or more organic solvents may be used in combination.

  The drying conditions are not particularly limited, but the drying is performed so that the content of the organic solvent in the resin composition layer is usually 10% by mass or less, preferably 5% by mass or less. Although it depends on the amount of organic solvent in the varnish, for example, a varnish containing 30 to 60% by mass of an organic solvent can be dried at 50 to 150 ° C. for about 3 to 10 minutes. Those skilled in the art can appropriately set suitable drying conditions by simple experiments.

  The thickness of the resin composition layer formed in the adhesive film 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. The resin composition layer may be protected by a protective film described 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.

  Examples of the support film and protective film in the present invention include polyolefins such as polyethylene, polypropylene, and polyvinyl chloride, polyethylene terephthalate (hereinafter sometimes abbreviated as “PET”), polyesters such as polyethylene naphthalate, polycarbonate, polyimide, Can include release paper, copper foil, metal foil such as aluminum foil, and the like. 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. The thickness of the protective film is not particularly limited, but is usually 1 to 40 μm, preferably 10 to 30 μm. In addition, as will be described later, a support film used as a support in the production process of the adhesive film can be used as a protective film for protecting the resin composition layer surface.

  The support film in the present invention is peeled 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 step can be prevented, and the surface smoothness of the insulating layer after curing can be improved. In the case of peeling after curing, the support film is usually subjected to a release treatment in advance. In addition, it is preferable to form the resin composition layer formed on a support film so that the area of a layer may become smaller than the area of a support film. The adhesive film can be wound up in a roll shape and stored and stored.

  Next, a method for producing the multilayer printed wiring board of the present invention using the adhesive film of the present invention will be described. When the resin composition layer is protected with a protective film, the resin composition layer is peeled and then laminated on one or both sides of the circuit board so that the resin composition layer is in direct contact with the circuit board. In the adhesive film of the present invention, a method of laminating on a circuit board under reduced pressure by a vacuum laminating method is preferably used. 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. and 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 a reduced pressure of 20 mmHg (26.7 hPa) or less.

  The vacuum lamination can be performed using a commercially available vacuum laminator. Commercially available vacuum laminators include, for example, a vacuum applicator manufactured by Nichigo-Morton Co., Ltd., a vacuum pressurizing laminator manufactured by Meiki Seisakusho, a roll dry coater manufactured by Hitachi Industries, Ltd., and Hitachi AIC Co., Ltd. ) Made vacuum laminator and the like.

  The circuit board in the present invention is mainly a conductive layer (circuit) patterned on one or both sides of a substrate such as a glass epoxy, metal substrate, polyester substrate, polyimide substrate, BT resin substrate, thermosetting polyphenylene ether substrate or the like. The one formed. Also included in the circuit board of the present invention is a multilayer printed wiring board in which conductor layers and insulating layers are alternately formed and a conductor layer (circuit) is patterned on one or both sides. The surface of the conductor circuit layer is preferably roughened by blackening or the like in advance from the viewpoint of adhesion of the insulating layer to the circuit board.

  Thus, after laminating the adhesive film on the circuit board, when the support film is peeled off, the insulating film can be formed on the circuit board by peeling and thermosetting. The conditions of heat curing are selected in the range of 20 to 180 minutes at 150 to 220 ° C, more preferably 30 to 120 minutes at 160 to 200 ° C.

  If the support film is not peeled off after the insulating layer is formed, it is peeled off here. Next, holes are formed in the insulating layer formed on the circuit board to form via holes and through holes. Drilling can be performed by a known method such as drilling, laser, or plasma, or a combination of these methods if necessary. However, drilling by a laser such as a carbon dioxide laser or YAG laser is the most common method. .

  Next, a roughening process is performed on the surface of the insulating layer. The roughening treatment in the present invention is usually preferably carried out by a wet roughening method using an oxidizing agent. Examples of the oxidizing agent include permanganate (potassium permanganate, sodium permanganate, etc.), dichromate, ozone, hydrogen peroxide / sulfuric acid, nitric acid and the like. Preferably, an alkaline permanganate solution (eg, potassium permanganate, sodium hydroxide solution of sodium permanganate), which is an oxidizer widely used for roughening an insulating layer in the production of multilayer printed wiring boards by a built-up method. It is preferable to perform roughening using.

  The roughness of the roughened surface obtained by roughening the surface of the insulating layer is usually Ra value of 0.01 μm or more, preferably 0.1 μm or more, especially 0.15 μm so as to obtain an anchor effect with the conductor layer. It is preferable that the roughness is as described above. The upper limit of the Ra value is preferably 0.5 μm or less, more preferably 0.4 μm or less, and particularly preferably 0.35 μm or less from the viewpoint of the fine wiring formability.

  The surface roughness Ra value is a kind of numerical value representing the surface roughness, and is called arithmetic average roughness. Specifically, the surface roughness Ra is an average line whose height varies within the measurement region. Measured from the arithmetic average. For example, using WYKO NT3300 manufactured by Becoin Instruments Co., Ltd., a VSI contact mode and a numerical value obtained with a 50 × lens as a measurement range of 121 μm × 92 μm can be obtained.

  Next, a conductor layer is formed on the surface of the resin composition layer on which uneven anchors are formed by the roughening treatment by a method combining electroless plating and electrolytic plating. Alternatively, a plating resist having a pattern opposite to that of the conductor layer can be formed, and the conductor layer can be formed only by electroless plating. In addition, after forming the conductor layer, the peel strength of the conductor layer can be further improved and stabilized by annealing at 150 to 200 ° C. for 20 to 90 minutes.

  In addition, as a method of patterning the conductor layer to form a circuit, for example, a subtractive method or a semi-additive method known to those skilled in the art can be used.

  The prepreg of the present invention can be produced by impregnating the resin composition of the present invention into a sheet-like reinforcing substrate made of fibers by a hot melt method or a solvent method and semi-curing by heating. That is, it can be set as the prepreg which will be in the state which the resin composition of this invention impregnated the sheet-like reinforcement base material which consists of fibers.

  As the sheet-like reinforcing substrate made of fibers, for example, those commonly used as prepreg fibers such as glass cloth and aramid fibers can be used.

  In the hot melt method, without dissolving the resin in an organic solvent, the resin is once coated on the resin and a coated paper having good releasability, and then laminated on a sheet-like reinforcing substrate or directly applied by a die coater. Thus, a prepreg is manufactured. Similarly to the adhesive film, the solvent method is a method in which a sheet-like reinforcing base material is immersed in a resin varnish in which a resin is dissolved in an organic solvent, the resin varnish is impregnated into the sheet-like reinforcing base material, and then dried.

Next, a method for producing the multilayer printed wiring board of the present invention using the prepreg of the present invention will be described. One or several prepregs of the present invention are stacked on a circuit board, a metal plate is sandwiched through a release film, and press lamination is performed under pressure and heating conditions. The pressure is preferably 5 to 40 kgf / cm ² (49 × 10 ^{4 to} 392 × 10 ⁴ N / m ² ), and the temperature is preferably 120 to 200 ° C. for 20 to 100 minutes. Moreover, it can also be manufactured by laminating on a circuit board by a vacuum laminating method as in the case of an adhesive film, and then curing by heating. Thereafter, similarly to the method described above, the surface of the prepreg cured with an oxidizing agent is roughened, and then a conductor layer is formed by plating to produce a multilayer printed wiring board.

  The present invention will be described in more detail with reference to the following examples and comparative examples, but these are not intended to limit the present invention in any way. In the following description, “part” means “part by mass”.

  A butyral resin (glass transition temperature 105 ° C., “KS-5Z” manufactured by Sekisui Chemical Co., Ltd.) was dissolved in a 1: 1 mixed solvent of ethanol and toluene at 60 ° C. to a solid content of 15%. A butyral resin solution was obtained. 30 parts of liquid bisphenol A type epoxy resin (epoxy equivalent 180, “Epicoat 828EL” manufactured by Japan Epoxy Resin Co., Ltd.) and naphthalene type tetrafunctional epoxy resin (epoxy equivalent 163, manufactured by Dainippon Ink & Chemicals, Inc. “HP- 4700 ") was dissolved by heating in 15 parts of methyl ethyl ketone (hereinafter abbreviated as MEK) and 15 parts of cyclohexanone with stirring. There, 60 parts of MEK solution of 50% solid content of novolak resin (“CBN” manufactured by Nippon Kayaku Co., Ltd., phenolic hydroxyl group equivalent 139), which is a naphthol-based curing agent, is a phenol-based curing agent containing a thiomethyl group. 18 parts of a 60% solid MEK solution of a novolak resin (“YLH-1110L” manufactured by Japan Epoxy Resin Co., Ltd., phenolic hydroxyl group equivalent 168), curing catalyst (“2E4MZ” manufactured by Shikoku Kasei Co., Ltd.) 1 part, 70 parts of spherical silica (average particle size 0.5 μm, aminosilane treatment, “SOC2” manufactured by Admatechs) and 35 parts of the above butyral resin solution are mixed and uniformly dispersed with a high-speed rotating mixer to obtain a resin varnish. It was produced (inorganic filler content relative to the nonvolatile content of the resin varnish, 40% by mass). Next, the resin varnish is applied on polyethylene terephthalate (thickness 38 μm, hereinafter abbreviated as PET) with a die coater so that the resin thickness after drying is 40 μm, and is 80 to 120 ° C. (average 100 ° C.). It was dried for 6 minutes (residual solvent amount of about 1% by mass). Subsequently, it wound up in roll shape, bonding a 15-micrometer-thick polypropylene film on the surface of a resin composition. The roll-like adhesive film was slit to a width of 507 mm, and a sheet-like adhesive film having a size of 507 × 336 mm was obtained therefrom.

  30 parts of liquid bisphenol A type epoxy resin (epoxy equivalent 180, “Epicoat 828EL” manufactured by Japan Epoxy Resin Co., Ltd.) and naphthalene type tetrafunctional epoxy resin (epoxy equivalent 163, manufactured by Dainippon Ink & Chemicals, Inc. “HP- 4700 ") was dissolved by heating in 15 parts of methyl ethyl ketone (hereinafter abbreviated as MEK) and 15 parts of cyclohexanone with stirring. There, 60 parts of a 50% solid MEK solution of a novolak resin (“NOH” manufactured by Nippon Kayaku Co., Ltd., phenolic hydroxyl group equivalent 143), which is a naphthol-based curing agent, is a phenol-based curing agent containing a thiomethyl group. 18 parts of a 60% solid MEK solution of a novolak resin (“YLH-1110L” manufactured by Japan Epoxy Resin Co., Ltd., phenolic hydroxyl group equivalent 168), curing catalyst (“2E4MZ” manufactured by Shikoku Kasei Co., Ltd.) 1 part, 70 parts of spherical silica (average particle size 0.5 μm, aminosilane treatment, “SOC2” manufactured by Admatechs) and 35 parts of the butyral resin solution prepared in Example 1 are mixed and uniformly dispersed with a high-speed rotary mixer. Thus, a resin varnish was produced (inorganic filler content relative to the nonvolatile content of the resin varnish, 40% by mass). Next, a sheet-like adhesive film was obtained in the same manner as in Example 1.

  30 parts of liquid bisphenol A type epoxy resin (epoxy equivalent 180, “Epicoat 828EL” manufactured by Japan Epoxy Resin Co., Ltd.) and naphthalene type tetrafunctional epoxy resin (epoxy equivalent 163, manufactured by Dainippon Ink & Chemicals, Inc. “HP- 4700 ") was dissolved by heating in 15 parts of methyl ethyl ketone (hereinafter abbreviated as MEK) and 15 parts of cyclohexanone with stirring. There, 70 parts of a 50% solid MEK solution of a novolak resin (“CBN” manufactured by Nippon Kayaku Co., Ltd., phenolic hydroxyl group equivalent 139), which is a naphthol-based curing agent, is a phenol-based curing agent containing a thiomethyl group. 9 parts of MEK solution of 60% solid content of novolak resin (“YLH-1110L” manufactured by Japan Epoxy Resin Co., Ltd., phenolic hydroxyl group equivalent 168), curing catalyst (“2E4MZ” manufactured by Shikoku Kasei Co., Ltd.) 1 part, 70 parts of spherical silica (average particle size 0.5 μm, aminosilane treatment, “SOC2” manufactured by Admatechs) and 35 parts of the butyral resin solution prepared in Example 1 are mixed and uniformly dispersed with a high-speed rotary mixer. Thus, a resin varnish was produced (inorganic filler content relative to the nonvolatile content of the resin varnish, 40% by mass). Next, a sheet-like adhesive film was obtained in the same manner as in Example 1.

  30 parts of liquid bisphenol A type epoxy resin (epoxy equivalent 180, “Epicoat 828EL” manufactured by Japan Epoxy Resin Co., Ltd.) and naphthalene type tetrafunctional epoxy resin (epoxy equivalent 163, manufactured by Dainippon Ink & Chemicals, Inc. “HP- 4700 ") was dissolved by heating in 15 parts of methyl ethyl ketone (hereinafter abbreviated as MEK) and 15 parts of cyclohexanone with stirring. Thereto, 60 parts of a 50% solid content MEK solution of a novolak resin having a naphthalene structure as a phenolic curing agent (“CBN” manufactured by Nippon Kayaku Co., Ltd., phenolic hydroxyl group equivalent 139), a phenolic curing containing a thiomethyl group 18 parts of MEK solution with a solid content of 60% solids of novolak resin ("YLH-1110L" manufactured by Japan Epoxy Resin Co., Ltd., phenolic hydroxyl group equivalent 168), a curing catalyst ("2E4MZ" manufactured by Shikoku Chemicals Co., Ltd.) ) 0.1 part, 70 parts of spherical silica (average particle size 0.5 μm, aminosilane treatment, “SOC2” manufactured by Admatechs), 17 parts of butyral resin solution prepared in Example 1, phenoxy resin (Japan Epoxy Resin Co., Ltd.) ) "YX8100BH30" made by 30% solid content cyclohexanone and MEK mixing liquid) 17 parts mixed, high speed Uniformly dispersed in a converter mixer, the resin varnish was prepared (inorganic filler content relative to nonvolatile component of resin varnish, 39 wt%). Next, a sheet-like adhesive film was obtained in the same manner as in Example 1.

<Comparative Example 1>
30 parts of liquid bisphenol A type epoxy resin (epoxy equivalent 180, “Epicoat 828EL” manufactured by Japan Epoxy Resin Co., Ltd.) and naphthalene type tetrafunctional epoxy resin (epoxy equivalent 163, manufactured by Dainippon Ink & Chemicals, Inc. “HP- 4700 ") was dissolved by heating in 15 parts of methyl ethyl ketone (hereinafter abbreviated as MEK) and 15 parts of cyclohexanone with stirring. There, 50 parts of a novolak resin that is a phenolic curing agent (“TD2090-60M” manufactured by Dainippon Ink & Chemicals, Inc., MEK solution with a solid content of 60% by mass, phenolic hydroxyl group equivalent of solids 105), curing Catalyst (Shikoku Kasei Kogyo Co., Ltd., “2E4MZ”) 0.1 part, spherical silica (average particle size 0.5 μm, aminosilane treatment, “SOC2” manufactured by Admatechs) 60 parts, butyral prepared in Example 1 35 parts of the resin solution was mixed and dispersed uniformly with a high-speed rotary mixer to prepare a resin varnish (inorganic filler content with respect to the nonvolatile content of the resin varnish, 39% by mass). Next, a sheet-like adhesive film was obtained in the same manner as in Example 1.

<Reference Example 1>
30 parts of liquid bisphenol A type epoxy resin (epoxy equivalent 180, “Epicoat 828EL” manufactured by Japan Epoxy Resin Co., Ltd.) and naphthalene type tetrafunctional epoxy resin (epoxy equivalent 163, manufactured by Dainippon Ink & Chemicals, Inc. “HP- 4700 ") was dissolved by heating in 15 parts of methyl ethyl ketone (hereinafter abbreviated as MEK) and 15 parts of cyclohexanone with stirring. Thereto, 80 parts of a MEK solution having a solid content of 60% of a novolak resin (“YLH-1110L” manufactured by Japan Epoxy Resin Co., Ltd., phenolic hydroxyl group equivalent 168), which is a phenolic curing agent containing a thiomethyl group, a curing catalyst 0.1 part of “2E4MZ” manufactured by Kasei Kogyo Co., Ltd., 70 parts of spherical silica (average particle size 0.5 μm, aminosilane treatment, “SOC2” manufactured by Admatechs), butyral resin solution 35 prepared in Example 1 The parts were mixed and uniformly dispersed with a high-speed rotary mixer to prepare a resin varnish (inorganic filler content relative to the nonvolatile content of the resin varnish, 38% by mass). Next, a sheet-like adhesive film was obtained in the same manner as in Example 1.

<Reference Example 2>
30 parts of liquid bisphenol A type epoxy resin (epoxy equivalent 180, “Epicoat 828EL” manufactured by Japan Epoxy Resin Co., Ltd.) and naphthalene type tetrafunctional epoxy resin (epoxy equivalent 163, manufactured by Dainippon Ink & Chemicals, Inc. “HP- 4700 ") was dissolved by heating in 15 parts of methyl ethyl ketone (hereinafter abbreviated as MEK) and 15 parts of cyclohexanone with stirring. There, 41 parts of a novolak resin (Dai Nippon Ink Chemical Co., Ltd. “TD2090-60M”, MEK solution having a solid content of 60% by mass, phenolic hydroxyl group equivalent 105), phenol containing a thiomethyl group Novolak resin (Japan Epoxy Resin Co., Ltd. “YLH1110L”, phenolic hydroxyl group equivalent 168), curing catalyst (Shikoku Kasei Kogyo Co., Ltd., “2E4MZ”) 0.1 part, spherical silica (curing agent) Average particle size 0.5 μm, aminosilane treatment, “SOC2” (manufactured by Admatechs) 65 parts, 35 parts of butyral resin solution prepared in Example 1 are mixed and uniformly dispersed with a high-speed rotary mixer to produce a resin varnish (Inorganic filler content relative to nonvolatile content of resin varnish, 40% by mass). Next, a sheet-like adhesive film was obtained in the same manner as in Example 1.

  <Manufacture of multilayer printed wiring boards>

(1) Fabrication of circuit board A circuit pattern is formed by etching on both sides of a glass cloth base epoxy resin double-sided copper-clad laminate [copper foil thickness: 18 μm, board thickness: 0.8 mm, Matsushita Electric Works, Ltd. R5715ES] Furthermore, it was immersed in MEC Co., Ltd. CZ8100, the copper surface was roughened, and the circuit board was produced.

(2) Lamination of adhesive film The adhesive film created in Example 1 was laminated on both surfaces of a circuit board using a batch type vacuum pressure laminator MVLP-500 (trade name, manufactured by Meiki Co., Ltd.). Lamination was performed by reducing the pressure for 30 seconds to a pressure of 13 hPa or less, and then pressing at a pressure of 0.74 MPa for 30 seconds.

(3) Curing of resin composition The PET film was peeled from the laminated adhesive film, and the resin composition was cured under curing conditions of 180 ° C for 30 minutes.

(4) Via hole formation Using a CO ₂ laser processing machine (YB-HCS03T04) manufactured by Matsushita Welding System Co., Ltd., processing at a frequency of 1000 Hz with a pulse width of 13 μsec and a shot number of 3, the diameter of the insulating layer surface is A 60 μm via hole was formed.

(5) Roughening treatment The circuit board was immersed for 5 minutes at 60 ° C. in a swelling dip securigand P containing diethylene glycol monobutyl ether of Atotech Japan Co., Ltd., which is a swelling liquid. Next, it was immersed in the concentrate compact P (KMnO ₄ : 60 g / L, NaOH: 40 g / L aqueous solution) of Atotech Japan Co., Ltd., which is a roughening solution, at 80 ° C. for 20 minutes. Finally, it was immersed for 5 minutes at 40.degree. C. in a reduction solution Seuricin-Securigant P of Atotech Japan Co., Ltd., which is a neutralizing solution.

(6) Plating by semi-additive method In order to form a circuit on the surface of the insulating layer, the circuit board was immersed in an electroless plating solution containing PdCl ₂ and then immersed in an electroless copper plating solution. After annealing at 150 ° C. for 30 minutes, copper sulfate electrolytic plating was performed. Annealing treatment was performed at 180 ° C. for 60 minutes to form a copper layer having a thickness of about 25 μm on the surface of the insulating layer to obtain a multilayer printed wiring board.

  <Preparation of peel strength measurement sample>

(1) Substrate treatment of laminated board Glass cloth base epoxy resin double-sided copper-clad laminated board (copper foil thickness 18 μm, substrate thickness 0.8 mm, Matsushita Electric Works R5715ES) both sides of MEC CZ8100 The copper surface was roughened by immersion in

(2) Lamination of adhesive film Adhesive films prepared in Examples, Comparative Examples and Reference Examples were applied to both sides of a laminate using a batch type vacuum pressure laminator MVLP-500 (trade name, manufactured by Meiki Co., Ltd.). Laminated. Lamination was performed by reducing the pressure for 30 seconds to a pressure of 13 hPa or less, and then pressing at a pressure of 0.74 MPa for 30 seconds.

(3) Curing of resin composition The PET film was peeled from the laminated adhesive film, and the resin composition was cured under curing conditions of 180 ° C for 30 minutes.

(4) Roughening treatment The laminate was dipped in swelling dip securigand P containing diethylene glycol monobutyl ether of Atotech Japan Co., Ltd. for 5 minutes at 60 ° C., and then used as a roughening solution. Soaked in Concentrate Compact P (KMnO4: 60 g / L, NaOH: 40 g / L aqueous solution) at 80 ° C. for 20 minutes, and finally as a neutralizing solution, Atotech Japan Co., Ltd. It was immersed in securigant P at 40 ° C. for 5 minutes.

(5) Plating by semi-additive method The laminate was immersed in an electroless plating solution containing PdCl ₂ and then immersed in an electroless copper plating solution. After annealing at 150 ° C. for 30 minutes, copper sulfate electroplating was performed to form a copper layer with a thickness of 25 ± 10 μm. Next, annealing was performed at 180 ° C. for 60 minutes. The peel strength of the plated copper was measured for this laminate.

[Peeling strength of peeled copper layer (peel strength) test]
When the copper layer of the laminate is cut into a 10 mm wide and 100 mm long part, this end is peeled off and gripped with a gripper, and 35 mm is peeled off vertically at a speed of 50 mm / min at room temperature The load of was measured.

[Flame retardance test]
The adhesive films obtained in Examples, Comparative Examples and Reference Examples were laminated on both sides of a 0.2 mm thick glass epoxy substrate (R1566 manufactured by Matsushita Electric Works) and the resin was cured at 180 ° C. for 90 minutes. did. A sample test piece was prepared from the cured product according to UL-94, and a flame retardancy test was performed.

[Storage stability (pot life) test]
The adhesive films obtained in Examples, Comparative Examples, and Reference Examples were allowed to stand at room temperature (25 ° C.) for 72 hours, and a resin composition was used using a model Rhesol-G3000 manufactured by UBM Co., Ltd. The dynamic viscoelasticity of the layer was measured. The resin composition layer is a tablet having a diameter of about 20 mm and a thickness of about 2.3 mm (weight: about 1 g), which is used as a measurement sample. Measurement was performed under the conditions of a measurement interval temperature of 2.5 ° C., a frequency of 1 Hz / deg, and a constant static load of 100 g. As the curing progressed, the case where the viscosity was not measurable at the start of measurement and the overload was marked as x, and the case where the viscosity could be measured without being overloaded was marked as ◯.

  Table 1 shows the results of each test for the samples of Examples 1 to 4, Comparative Example 1 and Reference Examples 1 and 2. It turns out that an Example sample is excellent in all of a flame retardance, storage stability, and peel strength.

Industrial applicability

The epoxy resin composition of the present invention, the adhesive film prepared by the resin composition, and the prepreg are suitable as a material for forming an interlayer insulating layer of a multilayer printed wiring board, particularly a multilayer printed wiring board manufactured by a build-up method. used.
This application is based on patent application No. 2006-045638 filed in Japan, the contents of which are incorporated in full herein by reference.

Claims (20)

(A) An aromatic epoxy resin having two or more epoxy groups in one molecule, (B) a naphthol curing agent, (C) a thioalkyl group-containing phenol curing agent, and (D) an inorganic filler. An epoxy resin composition characterized by that. The epoxy resin composition of Claim 1 which contains the inorganic filler of a component (D) 20-60 mass% when the non-volatile component of an epoxy resin composition is 100 mass%. The epoxy resin composition of Claim 1 which contains the inorganic filler of a component (D) 30-50 mass% when the non-volatile component of an epoxy resin composition is 100 mass%. The epoxy resin composition of any one of Claims 1-3 whose inorganic filler of a component (D) is a silica. The epoxy resin composition of any one of Claims 1-4 whose compounding ratio of a component (B) and (C) is 1: 0.1-1: 1.5 by mass ratio. The naphthol-based curing agent of component (B) is represented by the following formula (1):

(Wherein R1 to R4 each independently represents a hydrogen atom or an alkyl group, X1 represents a naphthalene ring which may be substituted with an alkyl group, and Y may each be substituted with an alkyl group. A benzene ring, a hydroxybenzene ring, a biphenyl ring or a naphthalene ring, and j and k each represent an average value of 1 to 15.)
The thioalkyl group-containing phenolic curing agent of component (C) is represented by the following formula (2):

(In the formula, R5 represents a hydrogen atom or an alkyl group, R6 represents a thioalkyl group, X2 represents a benzene ring or a naphthalene ring each optionally substituted with an alkyl group, and j and k each represent an average value of 1; ) Represents a number of -15, and m represents an integer of 1-5.
The epoxy resin composition according to claim 1, wherein the epoxy resin composition is a thioalkyl group-containing phenolic curing agent represented by the formula: The naphthol-based curing agent of component (B) is represented by the following formula (1 ′):

(Wherein R1 to R4 each independently represents a hydrogen atom or an alkyl group, X1 represents a naphthalene ring which may be substituted with an alkyl group, and Y may each be substituted with an alkyl group. , A benzene ring, a hydroxybenzene ring, a biphenyl ring or a naphthalene ring, and n represents an average value of 1 to 15.)
And a thioalkyl group-containing phenolic curing agent of component (C) is represented by the following formula (2 ′):

(In the formula, R5 represents a hydrogen atom or an alkyl group, R6 represents a thioalkyl group, X2 represents a benzene ring or a naphthalene ring each optionally substituted with an alkyl group, and n represents an average value of 1 to 15. And m represents an integer of 1 to 5.)
The epoxy resin composition according to claim 1, wherein the epoxy resin composition is a thioalkyl group-containing phenolic curing agent represented by the formula: The aromatic epoxy resin of component (A) is (A1) a first epoxy resin that has two or more epoxy groups in one molecule and is a liquid aromatic epoxy resin at a temperature of 20 ° C., and ( A2) It has 3 or more epoxy groups in 1 molecule, and contains the 2nd epoxy resin which is a solid aromatic epoxy resin at the temperature of 20 degreeC, It is any one of Claims 1-7. Epoxy resin composition. The epoxy resin composition of Claim 8 whose epoxy equivalent of the 2nd epoxy resin of a component (A2) is 230 or less. The epoxy resin composition of Claim 8 whose epoxy equivalent of the 2nd epoxy resin of a component (A2) is the range of 150-230. The blending ratio (A1: A2) of the first epoxy resin (A1) and the second epoxy resin (A2) is in the range of 1: 0.3 to 1: 2 by mass ratio. The epoxy resin composition according to any one of the above. When the nonvolatile component of the epoxy resin composition is 100% by mass, the content of the aromatic epoxy resin of component (A) is 10 to 50% by mass, and the component with respect to the epoxy group present in the epoxy resin composition The ratio of the phenolic hydroxyl group of the naphthol type hardening | curing agent of (B) and the thioalkyl group containing phenol type hardening | curing agent of a component (C) is 1: 0.5-1: 1.5, Any one of Claims 1-11. 2. The epoxy resin composition according to item 1. The epoxy resin composition according to any one of claims 1 to 12, wherein the epoxy resin composition further contains a polyvinyl acetal resin. The epoxy resin composition according to claim 13, wherein the content of the polyvinyl acetal resin is 2 to 20 mass% when the nonvolatile component of the epoxy resin composition is 100 mass%. The adhesive film by which the epoxy resin composition of any one of Claims 1-14 is layer-formed on the support film. A prepreg, wherein the epoxy resin composition according to any one of claims 1 to 14 is impregnated in a sheet-like reinforcing base material made of fibers. The multilayer printed wiring board by which the insulating layer is formed with the hardened | cured material of the epoxy resin composition of any one of Claims 1-14. It is a manufacturing method of the multilayer printed wiring board including the process of forming an insulating layer on an inner-layer circuit board, and the process of forming a conductor layer on this insulating layer, Comprising: This insulating layer is any one of Claims 1-14 A multilayer printed wiring board, wherein the conductive layer is formed by copper plating on a roughened surface obtained by roughening the surface of the insulating layer. Manufacturing method. 16. A method for manufacturing a multilayer printed wiring board comprising a step of forming an insulating layer on an inner layer circuit board and a step of forming a conductor layer on the insulating layer, wherein the insulating layer comprises the adhesive film as an inner layer circuit. Laminated on the substrate, the epoxy resin composition is heat-cured with or without peeling off the support film, and the support film is peeled off when the support film is present after curing. A method for producing a multilayer printed wiring board, wherein the roughened surface of the layer surface is formed by copper plating. 17. A method of manufacturing a multilayer printed wiring board comprising a step of forming an insulating layer on an inner layer circuit board and a step of forming a conductor layer on the insulating layer, the insulating layer comprising the prepreg according to claim 16 as an inner layer circuit board. A multilayer printed wiring, characterized in that it is formed by laminating and thermosetting an epoxy resin composition, and the conductor layer is formed by copper plating on a roughened surface obtained by roughening the surface of the insulating layer. A manufacturing method of a board.