TWI433887B - Epoxy resin composition - Google Patents

Description

Epoxy resin composition

The present invention relates to an epoxy resin composition suitable for forming an insulating layer of a multilayer printed circuit board.

In recent years, with the development of miniaturization and high performance of electronic devices, multilayer printed circuit boards have further progressed to multilayering, miniaturization of wiring, and high density. As for a method of forming a conductor suitable for forming a high-density fine wiring, an additive method of forming a conductor layer by electroless plating after roughening the surface of the insulating layer, and electroless plating and electrolytic plating are known. A semi-additive method of forming a conductor layer. In these methods, the adhesion between the insulating layer and the plated conductor layer is mainly ensured by the unevenness of the surface of the insulating layer formed by the roughening treatment. That is, the anchoring effect with the plating layer is obtained by having irregularities on the surface of the insulating layer. Therefore, in order to increase the adhesion, it is considered to increase the degree of roughness (roughness) of the surface of the insulating layer.

However, in order to make the wiring high, the roughness of the surface of the insulating layer is preferably small. That is, after the conductor layer is formed by electroless plating or electrolytic plating, the wiring is removed by flash etching to remove the plating layer of the thin film, and if the surface roughness of the insulating layer is large, the buried layer is removed. It is necessary to perform rapid etching for a long time for the conductor layer of the concave portion, and if the rapid etching is performed for a long period of time, the risk of damaging the fine wiring or breaking the wire is high. Therefore, in order to form a highly reliable high-density wiring, it is required that the roughness of the surface of the insulating layer after the roughening treatment is small, and the adhesion to the plated conductor is required to be excellent.

Furthermore, the insulating material of the multilayer printed substrate must be flame retardant, and in recent years, in view of environmental considerations, it is preferred to use a non-halogen-based flame retardant. As an example of a non-halogen-based flame retardant, a phosphorus-based flame retardant is known. For example, JP-A-2001-181375 discloses a phosphorus-containing epoxy resin and a phenolic curing agent, and a specific phenoxy resin. When the epoxy resin composition is used as an insulating layer of a multilayer printed circuit board, it has high heat resistance and flame retardancy, and the conductor layer formed by electroplating is excellent in peeling strength. However, the roughness of the surface of the insulating layer after roughening described in the examples of the patent specification is large, and there is a limit to fine wiring.

For example, JP-A-2003-11269 discloses that an epoxy resin composition containing a phosphorus compound having a phenolic hydroxyl group is excellent in insulation property and heat resistance when used as a copper foil insulating material. However, this patent document does not disclose that a resin composition having low roughness and high peel strength can be obtained when used as an insulating layer, and such problems are not prompted.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an epoxy resin composition which is suitable for use as an epoxy resin composition as an insulating layer of a multilayer printed circuit board, which can be achieved after roughening treatment The roughness of the roughened surface is relatively small, but the roughened surface exhibits a high adhesion to the plated conductor and is excellent in flame retardancy.

As a result of active research by the present inventors to solve the above problems, it has been found that an epoxy resin, an epoxy hardener, and an epoxy compound of a phenoxy resin and/or a polyvinyl acetal resin and a phosphorus-containing benzoxazine compound are found. In the resin composition, if the cured product obtained by curing the epoxy resin is roughened, even if the roughened surface roughness is relatively small, the adhesion can be adhered to the plated conductor with high adhesion, and the flame retardancy is excellent. Thus the present invention has been completed.

That is, the present invention encompasses the following.

[1] An epoxy resin composition characterized by comprising (A) an epoxy resin, (B) an epoxy hardener, (C) a phenoxy resin and/or a polyvinyl acetal resin, and (D) a phosphorus-containing compound Benzooxazine compounds.

[2] The epoxy resin composition according to the above [1], wherein the phosphorus-containing benzoxazine compound is a phosphorus-containing benzoxazine compound represented by the following formula (1):

[3] The epoxy resin composition according to the above [1] or [2], wherein the epoxy curing agent is one or more selected from the group consisting of a phenolic curing agent, a naphthol curing agent, and an active ester curing agent. Epoxy hardener.

[4] The epoxy resin composition according to any one of the above [1], wherein the content of the component (A) is 10 when the nonvolatile component of the epoxy resin composition is 100% by mass. ~50% by mass, the content of the component (C) is 2 to 20% by mass, and the content of the component (D) is 2 to 20% by mass, and the reactive group of the epoxy curing agent is present in the epoxy resin composition. The ratio of one epoxy group is 1:0.5 to 1:1.1.

[5] The epoxy resin composition according to any one of the above [1] to [4] further comprising an inorganic filler.

[6] The epoxy resin composition according to the above [5], wherein the content of the inorganic filler is from 10 to 60% by mass based on 100% by mass of the nonvolatile component of the epoxy resin composition.

[7] A film comprising a layer of the epoxy resin composition according to any one of the above [1] to [6], which is formed on the support film.

[8] A prepreg according to any one of the above [1] to [6], wherein the sheet-like fibrous base material comprising the fibers is impregnated with the epoxy resin composition according to any one of the above [1] to [6].

[9] A multilayer printed wiring board comprising the insulating layer formed of the cured product of the epoxy resin composition according to any one of the above [1] to [6].

[10] A method of manufacturing a multilayer printed circuit board, comprising the steps of forming an insulating layer on an inner layer circuit substrate and forming a conductor layer on the insulating layer, wherein the insulating layer is such that [1] The epoxy resin composition according to any one of [6] is formed by thermal curing, and the conductor layer is formed by electroplating on the roughened surface of the surface of the insulating layer which has been roughened.

[11] A method of manufacturing a multilayer printed circuit board, comprising the steps of forming an insulating layer on an inner layer circuit substrate and forming a conductor layer on the insulating layer, characterized by having an insulating layer forming step, the insulating layer a step of roughening the surface and a step of plating the rough surface; the insulating layer forming step is a step of laminating an adhesive film forming a layer on the support film of the above [7] on the inner circuit substrate and making the epoxy The step of thermally hardening the resin composition.

[12] A method of manufacturing a multilayer printed circuit board, comprising the steps of forming an insulating layer on an inner layer circuit substrate and forming a conductor layer on the insulating layer, wherein the insulating layer is an inner layer circuit substrate The prepreg according to the above [8] is laminated, and the epoxy resin composition is thermally cured. The conductor layer is formed by electroplating on the roughened surface of the surface of the insulating layer which has been roughened.

[13] The method for producing a multilayer printed wiring board according to any one of [10] to [12] wherein the roughening treatment is carried out using an alkaline permanganic acid solution.

According to the present invention, it is possible to introduce, in a multilayer printed circuit board, an insulating layer which has a rough surface roughness after roughening treatment and which has excellent adhesion strength and excellent flame retardancy with a conductor layer formed by plating.

[Epoxy Resin of Ingredient (A)]

The epoxy resin of the component (A) in the present invention is not particularly limited, and examples thereof include, for example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, and phenol novolak type ring. Oxygen resin, t-butyl catechol type epoxy resin, naphthol type epoxy resin, naphthalene type epoxy resin, glycidylamine type epoxy resin, cresol novolak type epoxy resin, biphenyl type ring Oxygen resin, linear aliphatic epoxy resin, alicyclic epoxy resin, heterocyclic epoxy resin, epoxy resin containing a spiro ring, halogenated epoxy resin, and the like.

The epoxy resin is preferably a bisphenol A type epoxy resin, a naphthol type epoxy resin, or a naphthalene type epoxy resin from the viewpoints of heat resistance, insulation reliability, and adhesion to a metal film. , biphenyl type epoxy resin, epoxy resin with butadiene structure. Specifically, a liquid bisphenol A type epoxy resin ("Epicote 828EL" (jER828EL) manufactured by Nippon Epoxy Co., Ltd.), a naphthalene type 2-functional epoxy resin (Daily Ink Chemical Industry Co., Ltd.) is exemplified. "HP4032" and "HP4032D"), naphthalene-type 4-functional epoxy resin ("HP4700" manufactured by Dainippon Ink Chemicals Co., Ltd.), and naphthol-type epoxy resin (ESN manufactured by Tohto Kasei Co., Ltd.) -475V"), epoxy resin containing butadiene structure ("PB-3600" manufactured by Daicel Chemical Industry Co., Ltd.), epoxy resin having biphenyl structure ("NC3000H" manufactured by Nippon Kayaku Co., Ltd.," NC3000L", "YX4000" made by Japan Epoxy Co., Ltd.).

The epoxy resins may be used alone or in combination of two or more, but usually contain an epoxy resin having two or more epoxy groups in one molecule. When the non-volatile component of the epoxy resin composition is 100% by mass, it is preferably at least 50% by mass or more of an epoxy resin having two or more epoxy groups in one molecule. Further, a preferred embodiment is an epoxy resin having an aromatic epoxy resin having two or more epoxy groups and having a liquidity at a temperature of 20 ° C, and having three or more epoxy groups in one molecule. An aromatic epoxy resin which is solid at a temperature of 20 °C. Moreover, the aromatic epoxy resin in the present invention means an epoxy resin having an aromatic ring skeleton in its molecule. Further, the epoxy equivalent (g/eq) means the molecular weight per 1 epoxy group. In the case of using an epoxy resin and a solid epoxy resin, when the epoxy resin composition is used in the form of a film, it is possible to form a film which exhibits sufficient flexibility and excellent handleability. It is also possible to increase the breaking strength of the cured product of the epoxy resin composition and to improve the durability of the multilayer printed circuit board.

Further, as the epoxy resin, when the liquid epoxy resin and the solid epoxy resin are used in combination, the mixing ratio (liquid form: solid form) is preferably in the range of 1:0.3 to 1:2 by mass ratio. When the ratio of the liquid epoxy resin is within this range, the viscosity of the epoxy resin composition is not improved, and when it is used in the form of a film, the degassing property at the time of vacuum lamination is lowered, and voids are unlikely to occur. Further, the peeling property of the protective film or the support film at the time of vacuum lamination is not lowered, or the heat resistance after hardening is not lowered. Further, sufficient fracture strength can be obtained in the cured product of the epoxy resin composition. On the other hand, when the ratio of the solid epoxy resin is within this range and is used in the form of a film, sufficient flexibility can be obtained, and workability is good, and sufficient fluidity can be obtained at the time of lamination.

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 the epoxy resin is preferably from 10 to 50% by mass, more preferably from 20 to 40% by mass, It is preferably 20 to 35 mass%. When the content of the epoxy resin (A) is within this range, the curability of the resin composition is good.

[Epoxy hardener of component (B)]

The epoxy curing agent used in the present invention is preferably an epoxy resin selected from one or more selected from the group consisting of a phenolic curing agent, a naphthol curing agent, and an active ester curing agent. hardener. The phenolic curing agent and the naphthol-based curing agent are preferably a phenolic curing agent having a novolak structure or a naphthol-based curing agent having a novolac structure from the viewpoint of heat resistance and water resistance. Commercial products of such a phenolic curing agent having a novolak structure or a naphthol-based curing agent having a novolak structure are exemplified by, for example, MEH-7700, MEH-7810, and MEH-7851 (manufactured by Megumi Kasei Co., Ltd.). NHN, CBN, GPH (Nippon Chemical Co., Ltd.), SN170, SN180, SN190, SN475, SN485, SN495, SN375, SN395 (Dongdu Chemical Co., Ltd.), LA7052, LA7054 (Daily Ink Chemical Industry Co., Ltd. ))). Examples of the active ester-based curing agent include EXB-9451, EXB-9460 (manufactured by Dainippon Ink Chemicals Co., Ltd.), DC808 (manufactured by Nippon Epoxy Resin Co., Ltd.), and the like. In the present invention, the curing agent may be used singly or in combination of two or more kinds. In particular, since the reactivity of the active ester-based curing agent is inferior, it is preferred to use a phenol-based curing agent and/or a naphthol-based curing agent.

In the present invention, the amount of the epoxy hardener in the epoxy resin composition is usually a ratio of the total number of reactive groups of the epoxy hardener to the total number of epoxy groups present in the epoxy resin composition. When the number of oxygenation is 1, it is preferably a halo of 1:0.5 to 1:1.1, more preferably the ratio is 1:0.5 to 1:0.9. The total number of epoxy groups present in the epoxy resin composition is the total value of the solid content of each epoxy resin in the epoxy resin divided by the value of the epoxy equivalent, and the reaction of the so-called epoxy hardener The total number of bases (active hydroxyl groups, active ester groups, etc.) is the sum of the solid mass of each hardener in each hardener divided by the value of the reactive base equivalent. When the content of the curing agent is within this preferred range, the heat resistance of the cured product obtained by hardening the epoxy resin composition becomes insufficient.

[Phenolic resin and/or polyvinyl acetal resin of component (C)]

In the present invention, the phenoxy resin and/or the polyvinyl acetal resin are used for the purpose of imparting sufficient flexibility to the film and adjusting the roughening property. Specific examples of the phenoxy resin include FX280 and FX293 manufactured by Tohto Kasei Co., Ltd., and YX8100, YX6954, and YL6974 manufactured by Nippon Epoxy Resin Co., Ltd., and the like. The polyvinyl acetal resin is not particularly limited, but is preferably a polyvinyl butyral resin. Specific examples of the polyvinyl acetal resin include electro-chemical butyral 4000-2, 5000-A, 6000-C, and 6000-EP manufactured by the Electrochemical Industry Co., Ltd.; and S-REC manufactured by Sekisui Chemical Industry Co., Ltd. BH series, BX series, KS series, BL series, BM series, etc.

The polyvinyl acetal is preferably one having a glass transition temperature of 80 ° C or higher. Here, the "glass transition temperature" is determined in accordance with the method described in JIS K7197. Further, when the glass transition temperature is higher than the decomposition temperature and the glass transition temperature is not actually observed, the temperature can be decomposed as the glass transition temperature in the present invention. In addition, 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 K7120.

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 the phenoxy resin and/or the polyvinyl acetal resin is preferably from 2 to 20% by mass. range. Thereby, in this range, sufficient flexibility and workability are obtained, and the peeling strength of the conductor layer formed by electroplating becomes sufficient. When the amount is more than 20% by mass, sufficient fluidity cannot be obtained at the time of lamination, and the roughness tends to be excessive.

[Component (D) phosphorus-containing benzoxazine compound]

The phosphorus-containing benzoxazine compound to be used in the present invention is preferably a phosphorus-containing benzoxazine compound represented by the following formula (1) (refer to WO/2008/010429).

This compound contains phosphorus and functions as a halogen-free flame retardant. And reactive with epoxy resin. As a commercially available product, HF-BOZ06 (a dioxane solution of a phosphorus-containing benzoxazine compound represented by the formula (1)) and HFB-2006M (shown by the formula (1)) of Showa Polymer Co., Ltd. are exemplified. a solution of a phosphorus-containing benzoxazine compound in 1-methoxy-2-propanol). 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 the component (D) is preferably in the range of 2 to 20% by mass, more preferably 2 to 10% by mass. %, preferably 3 to 6 mass%. By setting the content of the component (D) to 2 to 20% by mass, the flame retardancy and low hygroscopicity of the cured product can be improved.

The epoxy resin composition of the present invention may further contain an inorganic filler for the purpose of lowering the coefficient of thermal expansion and the like. As the inorganic filler, for example, cerium oxide, aluminum oxide, barium sulfate, talc, clay, mica powder, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, magnesium oxide, boron nitride, aluminum borate, titanium can be exemplified. Barium strontium, barium titanate, calcium titanate, magnesium titanate, barium titanate, titanium oxide, barium zirconate, calcium zirconate, etc., among which are preferably amorphous cerium oxide, lanthanum oxidized cerium, crystalline cerium oxide, Synthesis of cerium oxide such as cerium oxide. As the cerium oxide, it is preferably spherical. The average particle diameter of the inorganic filler is preferably 1 μm or less, more preferably 0.8 μm or less, and most preferably 0.7 μm or less. When the average particle diameter exceeds 1 μm, the peel strength of the conductor layer formed by plating tends to decrease. When the average particle diameter of the inorganic filler is too small, when the epoxy resin composition is used as a resin varnish, the varnish viscosity tends to increase, and the handleability tends to be lowered. Therefore, the average particle diameter is preferably 0.05 μm or more. Further, in order to improve the moisture resistance of the inorganic filler, it is preferred to carry out surface treatment with a surface treatment agent such as an epoxy cyclane coupling agent, an amino decane coupling agent or a titanate coupling agent.

The average particle diameter of the above inorganic filler is determined by a laser diffraction scattering method according to the Mie scattering theory. The specific laser diffraction particle size distribution device prepares the particle size distribution of the inorganic filler on a volume basis, and the median diameter can be measured as the average particle diameter. The measurement sample can preferably be used in which an inorganic filler is dispersed in water by ultrasonic waves. As for the laser diffraction particle size distribution measuring apparatus, LA-500 manufactured by Horiba, Ltd., etc. can be used.

The content of the epoxy resin composition (100% by mass of the nonvolatile matter) in the preparation of the inorganic filler varies depending on the specific requirements of the resin composition, but is preferably from 10 to 60% by mass, more preferably 15 ~50% by mass, preferably 15 to 45% by mass.

The epoxy resin composition of the present invention contains solid rubber particles for the purpose of improving the mechanical strength of the cured product, and also for the purpose of stress relaxation effect or the like. The rubber particles in the present invention are organic solvents which are insoluble in the preparation of the epoxy resin composition, and are incompatible with components in the resin composition such as epoxy resin. Therefore, in the present invention, the rubber particles are present in a dispersed state in the varnish of the epoxy resin composition. These rubber particles are generally prepared in such a manner that the molecular weight of the rubber component is not dissolved in the organic solvent or the resin, and is prepared into a particulate form. Examples of the rubber particles include core-shell type rubber particles, crosslinked acrylonitrile butadiene rubber particles, crosslinked styrene butadiene rubber particles, and acrylic rubber particles. The core-shell type rubber particles are rubber particles in which the particles have a core layer and a shell layer, and for example, the shell layer of the outer layer is a glassy polymer, and the core layer of the inner layer is a two-layer structure composed of a rubber-like polymer, or an outer layer. The shell layer is a glassy polymer, the intermediate layer is a rubbery polymer, and the core layer is a three-layer structure composed of a glassy polymer. The glass layer is composed of a polymer of methyl methacrylate or the like, and the rubber-like polymer layer is composed of, for example, a butyl acrylate polymer (butyl rubber). Specific examples of the core-shell type rubber particles include Staphyloid AC3822, AC3816N (GANZ Chemicals Co., Ltd.), and Metablen KW-4426 (Mitsubishi RAYON Co., Ltd.). Specific examples of the acrylonitrile butadiene rubber (NBR) particles include XER-91 (average particle diameter: 0.5 μm, manufactured by JSR Co., Ltd.). Specific examples of the styrene butadiene rubber (SBR) particles include XSK-500 (average particle diameter: 0.5 μm, manufactured by JSR Co., Ltd.). Specific examples of the acrylic rubber particles include Metablen W300A (average particle diameter: 0.1 μm) and W450A (average particle diameter: 0.5 μm) (Mitsubishi RAYON (trade name) trade name).

The average particle diameter of the rubber particles to be blended is preferably in the range of 0.005 to 1 μm, more preferably in the range of 0.2 to 0.6 μm. The average particle diameter of the rubber particles in the present invention can be measured by dynamic light scattering. For example, the rubber particles are uniformly dispersed in an appropriate organic solvent by ultrasonic waves, and FPRA-1000 (manufactured by Otsuka Electronics Co., Ltd.) is used to prepare the particle size distribution of the rubber particles on a mass basis, and the median diameter can be measured as the average particle diameter.

When the rubber particles are blended, the content of the epoxy resin composition (100% by mass of the nonvolatile matter) is preferably from 1 to 10% by mass, more preferably from 2 to 5% by mass.

The epoxy resin composition of the present invention may contain a curing accelerator for the purpose of adjusting the curing time and the like. The hardening accelerator is exemplified by, for example, an organic phosphine compound, an imidazole compound, an amine-based adduct compound, a tertiary amine compound, and the like. Specific examples of the organic phosphine compound include triphenylphosphine (trade name: TPP), tetraphenylphosphonium tetraphenylborate (trade name: TPP-K), and triphenylphosphine triphenylborane (trade name: TPP-S). , tri-p-tolylphosphine (TPTP-S), the above is Beixing Chemical Industry Co., Ltd. and so on. Specific examples of the imidazole compound include 2-methylimidazole (trade name: Curezol 2MZ), 2-ethyl-4-methylimidazole (trade name: 2E4MZ), 2-ureidoimidazole (trade name: CllZ), and 1- Cyanoethyl-2-ureidoimidazole (trade name CllZ-CN), 1-cyanoethyl-2-ureidoimidazolium trimellitate (trade name CllZ-CNS), 2,4-diamine -6-[2'-ureidoimidazolyl-(1')]-ethyl-s-triazine (trade name CllZ-A), 2MZ-OK, 2,4-diamino-6-[2 'Methylimidazolyl-(1')]-ethyl-s-triazine isocyanuric acid adduct (trade name 2MA-OK), 2-phenyl-4,5-dihydroxymethylimidazole (trade name) 2PHZ), the above is the Shikoku Chemical Industry Co., Ltd. and so on. Specific examples of the amine-based adduct compound are, for example, NOVACURE (Asahi Kasei Industrial Co., Ltd. product name), FUZICURE (Fuji Chemical Industry Co., Ltd. trade name), and the like. Specific examples of the tertiary amine compound are exemplified by DBU (1,8-diazabicyclo[5,4,0]undec-7-ene). In the epoxy resin composition of the present invention, the content of the hardening accelerator is usually 0.1 in the case where the total amount of the epoxy resin and the phenolic hardener contained in the epoxy resin composition is 100% by mass (nonvolatile matter). Use in the range of ~5 mass%.

The epoxy resin composition of the present invention may contain a flame retardant other than the component (D) within a range not to impair the hardening of the present invention. Examples of the flame retardant include an organic phosphorus-based flame retardant, an organic nitrogen-containing phosphorus compound, a nitrogen compound, a xenon-based flame retardant, and a metal hydroxide.

The epoxy resin composition of the present invention may contain other resins than the above insofar as the effects of the present invention are exerted. Examples of the other resin include a cyanate resin, a polyimide resin, a polyamidoximine, a polyether oxime resin, a polyfluorene resin, and the like.

The epoxy resin composition of the present invention may contain other resin additives than the above insofar as the effects of the present invention are exerted. Examples of the resin additive include organic fillers such as strontium powder, nylon powder, and fluorine powder, tackifiers such as Orben and Benton, oxime, fluorine, and polymer defoamers or admixtures, and imidazole. A coloring agent such as an adhesion imparting agent such as a thiazole system, a triazole system or a decane coupling agent, or an indigo blue, indigo green, iodine green, pigment yellow or carbon black.

The epoxy resin composition of the present invention can be applied to a support film to form a resin composition layer to form a film for a multilayer printed circuit board, or can be impregnated into a sheet-like fiber substrate composed of fibers. The composition is a prepreg for an interlayer insulating layer of a multilayer printed circuit board. The resin composition of the present invention can be applied to a circuit board to form an insulating layer, but industrially, it is generally used as an adhesive film or a prepreg sheet to form an insulating layer.

The adhesive film of the present invention can be prepared by a method known to those skilled in the art, for example, by dissolving a resin composition in an organic solvent to prepare a resin varnish to support the film as a support, coating the resin varnish, and further heating or blowing hot air to make an organic solvent. It is dried and formed into a resin composition layer.

The organic solvent may, for example, be a ketone such as acetone, methyl ethyl ketone or cyclohexanone; ethyl acetate, butyl acetate, fibrin acetate, propylene glycol monomethyl ether acetate, carbitol. Acetate such as acetate; carbitol such as cellulase or butyl carbitol; aromatic hydrocarbon such as toluene or xylene; dimethylformamide, dimethylacetamide, A guanamine-based solvent such as N-methylpyrrolidone. One type of organic solvent may be used, or two or more types may be used in combination.

The drying conditions are not particularly limited, and the content of the organic solvent to the resin composition layer is usually 10% by mass or less, more preferably 5% by mass or less. Dry conditions can be set by appropriate experiments to set suitable and appropriate drying conditions. Although the amount of the organic solvent varies depending on the amount of the organic solvent in the varnish, for example, the varnish containing 30 to 60% by mass of the organic solvent is dried at 50 to 150 ° C for about 3 to 10 minutes.

The thickness of the resin composition layer formed on the subsequent film is usually equal to or greater than the thickness of the conductor layer. Since the thickness of the conductor layer on which the circuit substrate is formed is usually in the range of 5 to 70 μm, the thickness of the resin composition layer preferably has a thickness of 10 to 100 μm. The resin composition layer can also be protected by a protective film described later. By protecting with a protective film, it is possible to prevent dirt or the like from adhering to the surface of the resin composition layer or being damaged.

In the present invention, as the support film and the protective film, a film of a polyolefin such as polyethylene, polypropylene or polyvinyl chloride, polyethylene terephthalate (hereinafter sometimes referred to as "PET") or polynaphthalene dicarboxylic acid can be exemplified. A film of a polyester such as ethylene glycol ester, a polycarbonate film or a polyimide film may, for example, be a metal foil such as a release paper, a copper foil or an aluminum foil. Further, the support film and the protective film may be subjected to a release treatment in addition to atomization treatment or corona treatment.

The thickness of the supporting film is not particularly limited and is usually in the range of 10 to 150 μm, preferably 25 to 50 μm. Further, the thickness of the protective film is not particularly limited, and it is usually used in the range of 1 to 40 μm, more preferably 10 to 30 μm. Further, as will be described later, a protective film used as a support for the support film may be used as a protective film for protecting the surface of the resin composition layer.

The support film of the present invention is peeled off after being laminated on a circuit board or after forming an insulating layer by heat curing. Then, if the support film is peeled off after the film is heat-hardened, the adhesion of the dirt in the hardening step can be prevented, and the surface smoothness of the insulating layer after hardening can be improved. When peeling after hardening, the support film is usually subjected to a release treatment in advance. Further, the resin composition layer formed on the support film is preferably formed such that the area of the layer is smaller than the area of the support film. Then, the film can be taken up in a roll shape, and then stored and stored.

Next, a method of manufacturing 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 by a protective film, the resin composition layer is peeled off, and the resin composition layer is laminated on one side or both sides of the circuit board so as to directly contact the circuit board. The adhesive film of the present invention is preferably used in a method of laminating to a circuit substrate under reduced pressure by vacuum lamination. The lamination method may be batch or continuous in rolls. The film and the circuit substrate may be heated (preheated) as needed before lamination.

The lamination condition, the pressing temperature (laminating temperature) is preferably 70 to 140 ° C, and the pressing pressure is preferably 1 to 11 kgf/cm ² (9.8×10 ⁴ to 107.9×10 ⁴ N/m ² ), preferably Lamination was carried out under reduced pressure at an air pressure of 20 mmHg (26.7 hPa) or less.

Vacuum lamination can be carried out using a commercially available vacuum laminator. As for the commercially available vacuum laminating machine, for example, a vacuum coater manufactured by NICHIGO MORTON Co., Ltd., a vacuum press laminator manufactured by a famous machine manufacturer, and a roll dry coat made by Hitachi Industrial Co., Ltd. Cloth machine, vacuum laminator made by Hitachi AIC (share).

The inner layer circuit substrate in the present invention mainly means a single side of a substrate such as a glass epoxy, a metal substrate, a polyester substrate, a polyimide substrate, a BT resin substrate, or a thermosetting polyphenylene ether substrate. A patterned conductor layer (circuit) is formed on both sides. Further, the conductor layer and the insulating layer form an alternating layer, and the conductor layer (circuit) is patterned on one or both sides. When manufacturing the multilayer printed circuit board, it is suitable to form an intermediate layer of the insulating layer and the conductor layer. Also included in the inner layer circuit substrate of the present invention. In the inner layer circuit board, from the viewpoint of the adhesion of the insulating layer to the inner layer circuit board, it is preferable to apply a roughening treatment to the surface of the conductor circuit layer by blackening treatment or the like.

After the film is laminated on the circuit board in this manner, the support film is peeled off, and the insulating layer can be formed on the circuit board by peeling and heat curing. The heat hardening condition is selected from 150 ° C to 220 ° C for a period of from 20 minutes to 180 minutes, more preferably from 160 ° C to 200 ° C for 30 minutes to 120 minutes.

After the insulating layer was formed, the support film was not peeled off before the hardening, and peeling was performed there. Then, a hole is formed in the insulating layer formed on the circuit board to form a buried hole and a through hole. The opening is performed by a known method such as drilling, laser, plasma, etc., and may be combined according to necessity, but the opening by a laser such as a carbon dioxide gas laser or a YAG laser is more common. The method.

Next, roughening treatment of the surface of the insulating layer is performed. 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 oxidizing agent widely used for roughening an insulating layer in a multilayer printed circuit board by a built-up method is preferably used, and an alkaline permanganic acid solution (for example, potassium permanganate or sodium permanganate solution is preferably used. ) roughening.

The roughness of the roughened surface on which the surface of the insulating layer is roughened is preferably 0.5 μm or less in forming fine wiring. The Ra value is a value indicating the surface roughness, and is called an arithmetic mean roughness. Specifically, it is an arithmetic average of the surface measurement of the average line of the absolute value of the height of change in the measurement region. For example, WYKO NT3300 manufactured by Veeco Instruments Co., Ltd. can be used to obtain a value obtained by measuring a range of 121 μm × 92 μm from a 50-fold lens in a VSI contact mode.

Next, on the surface of the resin composition layer on which the unevenness is anchored by roughening treatment, a conductor layer is formed by a combination of electroless plating and electrolytic plating. Further, the conductor layer may be a plating resist which forms an inverse pattern, and the conductor layer is formed only by electroless plating. After the conductor layer is formed, the peeling strength of the conductor layer can be further improved and stabilized by annealing at 150 to 200 ° C for 20 to 90 minutes. The peeling strength of the conductor layer is preferably 0.6 kgf/cm or more.

Further, as a method of forming a circuit for patterning a conductor layer, for example, a reduction method known in the art (a method of forming a circuit by removing a unnecessary portion from a copper-plated substrate) or a semi-additive method (on an insulator substrate) can be used. Since the method of attaching a circuit pattern, etc.).

In the prepreg of the present invention, the resin composition of the present invention can be produced by impregnating a sheet-like fibrous base material composed of fibers or the like by a hot melt method or a flux method, and semi-hardening by heating. That is, the resin composition of the present invention can be a prepreg impregnated in a state of a sheet-like fibrous base material composed of fibers.

As the sheet-like fibrous base material composed of fibers, for example, a glass cloth or an arylamine fiber can be used as a fiber user for a prepreg sheet.

In the hot melt method, the resin is temporarily dissolved in an organic solvent, and the resin is temporarily applied onto a coated paper having good peelability from the resin, laminated on a sheet-like fibrous substrate, or by a dye spin coater. A method of manufacturing a prepreg by directly coating or the like. Further, in the solvent method, a flaky fiber base material may be immersed in a resin varnish obtained by dissolving a resin in an organic solvent in the same manner as the adhesive film, and the resin varnish may be impregnated into the flaky fiber base material and then dried.

Next, a method of manufacturing the multilayer printed wiring board of the present invention using the prepreg of the present invention will be described. On the circuit substrate, one or a plurality of prepreg sheets of the present invention are overlapped, and the metal sheet is sandwiched between the release film and under pressure heating under pressure. The pressure is preferably 5 to 40 kgf/cm ² (49 × 10 ⁴ to 392 × 10 ⁴ N/m ² ), preferably 120 to 200 ° C, and the time is 20 to 100 minutes. Further, after laminating on a circuit board by vacuum lamination in the same manner as the subsequent film, it can be produced by heat curing. Subsequently, in the same manner as described above, the surface of the prepreg after curing is roughened by an oxidizing agent, and then a conductor layer is formed by electroplating to produce a multilayer printed wiring board.

In the following, the invention will be described in more detail by way of examples and comparative examples, which should not be construed as limiting the invention in any way. In the following description, "parts" means "parts by mass".

<Example 1>

30 parts of liquid bisphenol A type epoxy resin (epoxy equivalent 180, "Epicote 828EL" made by Nippon Epoxy Co., Ltd.) and 30 parts of biphenyl type epoxy resin (epoxy equivalent 291, Nippon Chemical Co., Ltd. The "NC3000H" system was heated and dissolved in 15 parts of methyl ethyl ketone (hereinafter referred to as "MEK") and 15 parts of cyclohexanone while stirring. Among them, 100 parts of a naphthol-based hardener ("SN485" manufactured by Tohto Kasei Co., Ltd.), a phenolic hydroxyl equivalent of 215), a solid solution of 50% MEK solution, and 0.1 part of a hardening catalyst (Four Nations Chemical Industry Co., Ltd.) )), "2E4MZ"), 70 parts of spherical cerium oxide (average particle size 0.5μm, "SO-C2" treated with amino decane, manufactured by Admatechs), 20 parts of polyvinyl butyral resin solution ( Glass transfer temperature 105 ° C, Sekisui Chemical Industry Co., Ltd. "KS-1" solids 15% ethanol and toluene 1:1 solution), 20 parts phenoxy resin (molecular weight 38,000, Japanese epoxy resin ) "YX6954", a 1:1 solution of MEK and cyclohexanone having a nonvolatile content of 30% by mass, and 8 parts of a phosphorus-containing benzoxazine represented by the formula (1) (manufactured by Showa Polymer Co., Ltd.) HF-BOZ06, a solid solution of 65% dioxane solution, was uniformly dispersed in a high-speed rotary mixer to prepare a resin varnish. Next, the resin varnish was applied onto polyethylene terephthalate (thickness: 38 μm) by a dye spin coater to make the thickness of the dried resin 40 μm, and dried at 80 to 120 ° C (average 100 ° C) for 6 minutes ( The amount of residual solvent was about 2% by mass). Then, a polypropylene film having a thickness of 15 μm was attached to the surface of the resin composition while being wound into a roll shape. The roll-like film was cut into a width of 507 mm, whereby a sheet-like film of 507 mm × 336 mm was obtained.

<Example 2>

30 parts of liquid bisphenol A type epoxy resin (epoxy equivalent 180, "Epicote 828EL" made by Nippon Epoxy Co., Ltd.) and 30 parts of biphenyl type epoxy resin (epoxy equivalent 291, Nippon Chemical Co., Ltd. The "NC3000H" system was heated and dissolved in 15 parts of MEK and 15 parts of cyclohexanone while stirring. Among them, 80 parts of a naphthol-based hardener ("SN485" manufactured by Tohto Kasei Co., Ltd.), a phenolic hydroxyl equivalent of 215), a solid component of 50% MEK solution, and 15 parts of an active ester-based hardener (Daily ink) "EXB9451" manufactured by Chemical Industry Co., Ltd., active base equivalent 223, solid content is divided into 65 mass% toluene solution, 0.1 part hardening catalyst ("European Chemical Industry Co., Ltd.", "2E4MZ"), 70 parts spherical Cerium oxide (average particle size 0.5 μm, "SO-C2" treated with amino decane, manufactured by Admatechs Co., Ltd.), 20 parts of polyvinyl butyral resin solution (glass transition temperature 105 ° C, Sekisui Chemical Industry Co., Ltd.) "KS-1" solids 15% ethanol and toluene 1:1 solution), 20 parts phenoxy resin (molecular weight 38,000, Japan Epoxy Resin Co., Ltd. "YX6954", non-volatile 30% by mass 1:1 solution of MEK and cyclohexanone), 15 parts of phosphorus-containing benzoxazine represented by formula (1) (HF-BOZ06 manufactured by Showa Polymer Co., Ltd., 65% solid content of dioxane) The solution was uniformly dispersed by a high-speed rotary mixer to prepare a resin varnish. Then, using this resin varnish, the following film was obtained in exactly the same manner as in Example 1.

<Comparative Example 1>

The resin varnish described in Example 1 was completely the same except that 8 parts of phosphorus-containing benzoxazine (HF-BOZ06 manufactured by Showa Polymer Co., Ltd., 65% solid solution of dioxane) was added. A follow-up film was obtained.

<Comparative Example 2>

30 parts of liquid bisphenol A type epoxy resin (epoxy equivalent 180, "Epicote 828EL" made by Nippon Epoxy Co., Ltd.) and 30 parts of phosphorus-containing epoxy resin (epoxy equivalent 306, manufactured by Tohto Kasei Co., Ltd.) "FX289") was dissolved by heating in 15 parts of MEK and 15 parts of cyclohexanone while stirring. Among them, 100 parts of a naphthol-based hardener ("SN485" manufactured by Tohto Kasei Co., Ltd.), a phenolic hydroxyl equivalent of 215), a solid solution of 50% MEK solution, and 0.1 part of a hardening catalyst (Four Nations Chemical Industry Co., Ltd.) )), "2E4MZ"), 70 parts of spherical cerium oxide (average particle size 0.5μm, "SO-C2" treated with amino decane, manufactured by Admatechs), 20 parts of polyvinyl butyral resin solution ( Glass transfer temperature 105 ° C, Sekisui Chemical Industry Co., Ltd. "KS-1" solids 15% ethanol and toluene 1:1 solution), 20 parts phenoxy resin (molecular weight 38,000, Japanese epoxy resin "YX6954", a 1:1 solution of MEK and cyclohexanone having a nonvolatile content of 30% by mass, was uniformly dispersed by a high-speed rotary mixer to prepare a resin varnish. Then, using this resin varnish, the following film was obtained in exactly the same manner as in Example 1.

<Comparative Example 3>

In the resin varnish described in Example 1, 8 parts of phosphorus-containing benzoxazine (HF-BOZ06 manufactured by Showa Polymer Co., Ltd., 65% solid solution of dioxane) was changed to 8 parts of phosphorus-based flame retardant. Except for the agent (HCA-HQ-HS manufactured by Sanguang Co., Ltd.), the others were identical, and a film was obtained.

<Modulation of sample for peel strength and Ra value measurement> (1) Underlayer treatment of laminate

The glass cloth substrate of the inner layer circuit is immersed in an organic acid etchant (Mecc) on both sides of a copper laminate (copper foil thickness: 18 μm, substrate thickness: 0.3 mm, and Matsushita Electric Co., Ltd. R5715ES). In the system, CZ8100), the copper surface is roughened.

(2) followed by lamination of the film

The adhesive film prepared in the examples and the comparative examples was laminated on both sides of the laminate using a batch vacuum pressure laminator MVLP-500 (trade name, manufactured by a famous machine). The lamination system was carried out by depressurizing to a gas pressure of 30 hPa or less in 30 seconds, followed by pressurization at 100 ° C and a pressure of 0.74 MPa in 30 seconds.

(3) Hardening of resin composition

The resin composition was cured by a film-peeled PET film which was laminated and laminated at 180 ° C for 30 minutes.

(4) roughening treatment

The laminate is immersed in a swelling solution of Atotech Co., Ltd. in Japan, containing Diethylene glycol monobutyl ether, Sering Dip. In SecurGund P, Concentrate is then immersed in the roughening liquid of Atotech Japan. Compact P (KMnO ₄ : 60g / L, NaOH: 40g / L aqueous solution), and finally in the neutralizing solution of Japan Atotech (stock) Reduction Solution. The SecurGund P was immersed at 40 ° C for 5 minutes. Roughening conditions: immersed in a swelling solution at 60 ° C for 5 minutes, and immersed in a roughening solution at 80 ° C for 20 minutes. The surface roughness (Ra value) of the laminate after the roughening treatment was measured.

(5) Electroplating according to the semi-additive method

In order to form a circuit on the surface of the insulating layer, the laminate was immersed in a solution for electroless plating containing PdCl ₂ and then immersed in an electroless copper plating solution. After annealing at 150 ° C for 30 minutes, an etching resist was formed, and a pattern was formed by etching, and then copper sulfate electrolytic plating was performed to form a conductor layer having a thickness of 30 ± 5 μm. Next, annealing treatment was performed at 180 ° C for 60 minutes. The laminate was tested for peel strength of copper plating.

<Measurement of peeling strength (peeling strength) of electroplated conductor layer>

On the conductor layer of the laminate, cut into a portion having a width of 10 mm and a length of 100 mm, peeling off one end thereof and sandwiching it with a jig, and measuring at a temperature of 50 mm/min at room temperature for peeling 35 mm in a vertical direction of the laminate. The load is heavy.

<Measurement of surface roughness (Ra value) after roughening>

Using a non-contact surface roughness meter (WYKO NT3300, manufactured by Veeco Instruments Co., Ltd.), the Ra value was obtained from a value obtained by a VSI contact mode and a 50-fold lens with a measurement range of 121 μm × 92 μm. It was also measured by obtaining a 10-point average roughness.

<Preparation of sample for flame retardancy test> (1) Underlayer treatment of laminate

For the glass cloth substrate epoxy resin laminate (product of copper foil etching, substrate thickness 0.3 mm, R5715ES manufactured by Matsushita Electric Works Co., Ltd.), the examples and comparative examples were used as the film, and a batch vacuum was used. A pressure laminator MVLP-500 (trade name, manufactured by a famous machine) was laminated on both sides of the laminate. The laminate was depressurized to a pressure of 13 hPa or less in 30 seconds, and then pressed at 100 ° C and a pressure of 0.74 MPa in 30 seconds. After the PET film was peeled off from the laminated film, the same film was laminated thereon twice under the same conditions.

(2) Hardening of resin composition

The PET film was peeled off from the film which was laminated at the last, and the resin composition was hardened at 180 ° C for 90 minutes. Thereafter, it was cut into a size of 12.7 mm × 127 mm for UL flame retardancy test, and the end surface was ground with sandpaper (originally #1200, then #2800), and the insulating layer was laminated on one side of the substrate thickness of 0.3 mm. A test piece for a flammability test was prepared at 120 μm. Subsequently, an evaluation of 94 V0 or 94 V1 was performed in accordance with the UL fire resistance test specification.

The peeling strength of the plated conductor layer and the surface roughness (Ra value) after roughening of the evaluation sample of the adhesive film obtained by the Example and the comparative example are shown in Table 1. As is understood from Table 1, the evaluation sample of the example using the phosphorus-containing benzoxazine compound in the present invention is excellent in low roughness and high peel strength, and the flame retardancy is V0. Further, in the case of Comparative Example 1 in which the phosphorus-containing benzoxazine compound was not used, the peel strength was high, but the flame retardancy was deteriorated, and the roughness was increased. Further, in the case of Comparative Examples 2 and 3 in which other phosphorus-containing compounds were used instead of the phosphorus-containing benzoxazine compound in the present invention, the peel strength was obtained, but the peel strength was obtained, and the roughness strain was large. The result.

[Industry use possibility]

The resin composition of the present invention, the film or prepreg prepared by the resin composition can be suitably used for interlayer insulation of a multilayer printed circuit board, in particular, a multilayer printed circuit board manufactured by a built-up method. material.

The present application is based on Japanese Patent Application No. 2007-245801, the entire disclosure of which is incorporated herein by reference.

Claims (14)

An epoxy resin composition characterized by comprising (A) an epoxy resin, (B) an epoxy hardener, (C) a phenoxy resin and/or a polyvinyl acetal resin, and (D) a benzoxazole containing phosphorus a azine compound; the phosphorus-containing benzoxazine compound is a phosphorus-containing benzoxazine compound represented by the following formula (1): The epoxy resin composition according to the first aspect of the invention, wherein the epoxy curing agent is an epoxy resin comprising one or more selected from the group consisting of a phenolic curing agent, a naphthol curing agent, and an active ester curing agent. hardener. The epoxy resin composition according to the first aspect of the invention, wherein the content of the component (A) is 10 to 50% by mass, and the component (C) is used as the nonvolatile component of the epoxy resin composition. The content is 2 to 20% by mass, and the content of the component (D) is 2 to 20% by mass, and the ratio of the reactive group of the epoxy curing agent to the epoxy group present in the epoxy resin composition is 1: 0.5~1:1.1. The epoxy resin composition of claim 1, which further contains an inorganic filler. The epoxy resin composition of claim 4, wherein the non-volatile component of the epoxy resin composition is 100% by mass, The content of the filler is 10 to 60% by mass. An adhesive film characterized in that a layer of an epoxy resin composition according to any one of claims 1 to 5 is formed on a support film. A prepreg characterized in that the sheet-like fibrous base material composed of fibers is impregnated with the epoxy resin composition according to any one of claims 1 to 5. A multilayer printed circuit board characterized in that an insulating layer formed of a cured product of the epoxy resin composition according to any one of claims 1 to 5 is formed. A method of manufacturing a multilayer printed circuit board, comprising the steps of forming an insulating layer on an inner layer circuit substrate and forming a conductor layer on the insulating layer, wherein the insulating layer is in the scope of claims 1 to 5 The epoxy resin composition according to any one of the items is formed by thermal hardening, and the conductor layer is formed by electroplating on the roughened surface of the surface of the insulating layer which has been roughened. A method of manufacturing a multilayer printed circuit board having the steps of forming an insulating layer on an inner layer circuit substrate and forming a conductor layer on the insulating layer, characterized by having an insulating layer forming step and a rough surface of the insulating layer And a step of electroplating the rough surface; the insulating layer forming step is a step of laminating a film forming a layer on the support film of the sixth aspect of the patent application on the inner circuit substrate and forming the epoxy resin The step of thermal hardening. A method of manufacturing a multilayer printed circuit board having an inner layer a step of forming an insulating layer on the circuit substrate and a step of forming a conductor layer on the insulating layer, wherein the insulating layer is laminated on the inner layer circuit substrate to prepreg the prepreg according to item 7 of the patent application, so that the epoxy resin The composition is formed by thermal hardening, and the conductor layer is formed by electroplating on the roughened surface of the surface of the insulating layer which has been roughened. A method of producing a multilayer printed wiring board according to claim 9, wherein the roughening treatment is carried out using an alkaline permanganic acid solution. The method for producing a multilayer printed wiring board according to claim 10, wherein the roughening treatment is performed using an alkaline permanganic acid solution. The method for producing a multilayer printed wiring board according to claim 11, wherein the roughening treatment is performed using an alkaline permanganic acid solution.