JP5446866B2 - Epoxy resin composition - Google Patents

Description

  The present invention relates 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 in multilayer printed wiring boards, the build-up layer has been multilayered, and the miniaturization and higher density of the wiring are further advanced. As a conductor formation method suitable for forming high-density fine wiring, an additive method in which a conductor layer is formed by electroless plating after the surface of the insulating layer is roughened, and a conductor layer is formed by electroless plating and electrolytic plating. A semi-additive method is known. In these methods, the adhesion between the insulating layer and the plated conductor layer is ensured mainly by unevenness on the surface of the insulating layer formed by roughening treatment. That is, an anchor effect is obtained between the plating layer and the insulating layer surface having irregularities. Therefore, to increase the adhesion, it is conceivable to increase the degree of roughness (roughness) on the surface of the insulating layer.

  However, the surface roughness of the insulating layer is preferably small in order to further increase the wiring density. That is, after forming a conductor layer by electroless plating or electrolytic plating, and removing the thin plating layer by flash etching to complete wiring formation, if the roughness of the surface of the insulating layer is large, the conductor layer embedded in the recess is removed. Therefore, a long time of flash etching is required, and if the flash etching is performed for a long time, there is a high risk that the fine wiring is damaged or disconnected due to the influence. Therefore, in order to form a highly reliable high-density wiring, the insulating layer surface is required to have excellent adhesion to the plated conductor even if the roughness after the roughening treatment is small.

  Furthermore, the insulating material of the multilayer printed circuit board is required to have flame retardancy, and in recent years, non-halogen flame retardant tends to be used in consideration of the environment. As an example of the non-halogen flame retardant, a phosphorus flame retardant is known. For example, JP-A No. 2001-181375 discloses an epoxy resin containing a phosphorus-containing epoxy resin, a phenol-based curing agent, a specific phenoxy resin, and the like. It is disclosed that when the composition is used for an insulating layer of a multilayer printed wiring board, it has high heat resistance and flame retardancy and is excellent in peel strength of a conductor layer formed by plating. However, the roughness of the surface of the insulating layer after roughening described in the Examples of the same specification is large, and there is a limit to miniaturization.

  Further, for example, JP-A-2003-11269 discloses that an epoxy resin composition containing a phenolic hydroxyl group-containing phosphorus compound is excellent in insulation and heat resistance when used as an insulating material with a copper foil. Yes. However, even in this patent document, when used as an insulating layer, a resin composition that can provide low roughness and high peel strength is not disclosed, and such a problem is not presented.

  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, and after roughening treatment An epoxy resin composition capable of achieving an insulating layer having a high adhesion to a plated conductor and having an excellent flame retardance even though the roughness of the roughened surface is relatively small. Is to provide.

  As a result of intensive studies to solve the above problems, the present inventors have found that an epoxy resin composition containing an epoxy resin, an epoxy curing agent, a phenoxy resin and / or a polyvinyl acetal resin, and a phosphorus-containing benzoxazine compound, When the cured product obtained by curing the epoxy resin is roughened, the resulting roughened surface can be adhered to the plated conductor with high adhesion even if the roughness is relatively small. As a result, the present invention has been completed.

That is, the present invention includes the following contents.
[1] An epoxy resin composition comprising (A) an epoxy resin, (B) an epoxy curing agent, (C) a phenoxy resin and / or a polyvinyl acetal resin, and (D) a phosphorus-containing benzoxazine compound. .
[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 according to [1] or [2] above, wherein the epoxy curing agent is an epoxy curing agent composed of one or more selected from a phenolic curing agent, a naphthol curing agent and an active ester curing agent. Composition.
[4] When the nonvolatile component of the epoxy resin composition is 100% by mass, the content of the component (A) is 10 to 50% by mass, the content of the component (C) is 2 to 20% by mass, and the component (D ) Is 2 to 20% by mass, and the ratio of the reactive group of the epoxy curing agent to 1 epoxy group present in the epoxy resin composition is 1: 0.5 to 1: 1.1 The epoxy resin composition according to any one of [1] to [3].
[5] The epoxy resin composition according to any one of [1] to [4], further including an inorganic filler.
[6] The epoxy resin composition according to the above [5], wherein the content of the inorganic filler is 10 to 60% by mass when the nonvolatile component of the epoxy resin composition is 100% by mass.
[7] An adhesive film in which the epoxy resin composition according to any one of [1] to [6] is layered on a support film.
[8] A prepreg characterized in that the epoxy resin composition according to any one of [1] to [6] is impregnated in a sheet-like fiber substrate made of fibers.
[9] 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 [6].
[10] 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 the above-mentioned [1] to [ 6], wherein the epoxy resin composition is heat-cured and the conductor layer is formed by plating on a roughened surface obtained by roughening the surface of the insulating layer. Manufacturing method of printed wiring board.
[11] A method for manufacturing 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, the insulating layer forming step, the rough surface of the insulating layer A step of laminating an adhesive film formed on the support film according to the above [7] on the inner layer circuit board, and a step of forming an insulating layer and a step of plating on the rough surface. The manufacturing method of a multilayer printed wiring board characterized by including the step of thermosetting an epoxy resin composition.
[12] 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 comprises the prepreg as described in [8] above Is formed by thermosetting an epoxy resin composition, and the conductor layer is formed by plating on a roughened surface obtained by roughening the surface of the insulating layer. A method for producing a multilayer printed wiring board.
[13] The method for producing a multilayer printed wiring board according to any one of [10] to [12], wherein the roughening treatment is performed using an alkaline permanganate solution.

  According to the present invention, an insulating layer having excellent flame retardancy and excellent adhesion strength with a conductor layer formed by plating, although the roughness of the roughened surface after the roughening treatment is relatively small. It becomes possible to introduce into a multilayer printed wiring board.

[Epoxy resin of component (A)]
The epoxy resin of component (A) in the present invention is not particularly limited. For example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, phenol novolac type epoxy resin, tert-butyl-catechol type epoxy Resin, naphthol type epoxy resin, naphthalene type epoxy resin, glycidylamine type epoxy resin, cresol novolac type epoxy resin, biphenyl type epoxy resin, linear aliphatic epoxy resin, alicyclic epoxy resin, heterocyclic epoxy resin, spiro ring Containing epoxy resin, halogenated epoxy resin and the like.

  Among these, the epoxy resin has a bisphenol A type epoxy resin, a naphthol type epoxy resin, a naphthalene type epoxy resin, a biphenyl type epoxy resin, and a butadiene structure from the viewpoint of heat resistance, insulation reliability, and adhesion to a metal film. Epoxy resins are preferred. Specifically, for example, liquid bisphenol A type epoxy resin (“Epicoat 828EL” (“jER828EL”) manufactured by Japan Epoxy Resin Co., Ltd.), naphthalene type bifunctional epoxy resin (“HP4032” manufactured by Dainippon Ink & Chemicals, Inc.) ”,“ HP4032D]), naphthalene type tetrafunctional epoxy resin (“HP4700” manufactured by Dainippon Ink & Chemicals, Inc.), naphthol type epoxy resin (“ESN-475V” manufactured by Tohto Kasei Co., Ltd.), and butadiene structure Epoxy resin ("PB-3600" manufactured by Daicel Chemical Industries, Ltd.), epoxy resin having a biphenyl structure ("NC3000H", "NC3000L" manufactured by Nippon Kayaku Co., Ltd., "YX4000" manufactured by Japan Epoxy Resins Co., Ltd.) Etc.

  One epoxy resin may be used alone, or two or more epoxy resins may be used in combination, but usually an epoxy resin having two or more epoxy groups in one molecule is contained. When the nonvolatile component of the epoxy resin composition is 100% by mass, at least 50% by mass is preferably an epoxy resin having two or more epoxy groups in one molecule. Furthermore, an epoxy resin that is an aromatic epoxy resin that has two or more epoxy groups in one molecule and is liquid at a temperature of 20 ° C, and a solid that has three or more epoxy groups in one molecule and has a temperature of 20 ° C. The aspect which contains a shape-like aromatic epoxy resin is preferable. The aromatic epoxy resin in the present invention means an epoxy resin having an aromatic ring skeleton in the molecule. The epoxy equivalent (g / eq) is the molecular weight per epoxy group. By using a liquid epoxy resin and a solid epoxy resin as an epoxy resin, when using an epoxy resin composition in the form of an adhesive film, an adhesive film that exhibits sufficient flexibility and excellent handling properties can be formed. At the same time, the breaking strength of the cured product of the epoxy resin composition is improved, and the durability of the multilayer printed wiring board is improved.

  Moreover, when using together a liquid epoxy resin and a solid epoxy resin as an epoxy resin, the mixture ratio (liquid: solid) has the preferable mass ratio of 1: 0.3-1: 2. If the ratio of the liquid epoxy resin is within such a range, the adhesiveness of the epoxy resin composition does not increase, and when used in the form of an adhesive film, the deaeration at the time of vacuum lamination decreases and voids are generated. It will not be easy to do. Further, the peelability of the protective film and the support film and the heat resistance after curing are not lowered during vacuum lamination. Moreover, sufficient breaking strength is obtained in the cured product of the epoxy resin composition. On the other hand, if the ratio of the solid epoxy resin is within such a range, when used in the form of an adhesive film, sufficient flexibility is obtained, the handleability is good, and the fluidity is sufficient when laminating. can get.

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

[Epoxy curing agent of component (B)]
As an epoxy curing agent used in the present invention, an epoxy curing agent comprising at least one selected from a phenolic curing agent, a naphthol curing agent and an active ester curing agent is used in order to sufficiently exhibit the effects of the present invention. preferable. As the phenol-based curing agent and naphthol-based curing agent, a phenol-based curing agent having a novolak structure and a naphthol-based curing agent having a novolak structure are particularly preferable from the viewpoint of heat resistance and water resistance. Examples of commercially available phenolic curing agents having such a novolak structure and naphthol-based curing agents having a novolak structure include, for example, MEH-7700, MEH-7810, MEH-7785 (manufactured by Meiwa Kasei Co., Ltd.), NHN, CBN, GPH (manufactured by Nippon Kayaku Co., Ltd.), SN170, SN180, SN190, SN475, SN485, SN495, SN375, SN395 (manufactured by Tohto Kasei Co., Ltd.), LA7052, LA7054 (manufactured by Dainippon Ink & Chemicals, Inc.), etc. Is mentioned. Examples of the active ester curing agent include EXB-9451, EXB-9460 (manufactured by Dainippon Ink & Chemicals, Inc.), DC808 (manufactured by Japan Epoxy Resin Co., Ltd.), and the like. In the present invention, one type of curing agent may be used or two or more types may be used in combination. However, since active ester curing agents are inferior in reactivity, they are used in combination with phenolic curing agents and / or naphthol curing agents. It is preferable to do this.

  In the present invention, the amount of the epoxy curing agent in the epoxy resin composition is usually the ratio of the total number of reactive groups of the epoxy curing agent to the total number of epoxy groups present in the epoxy resin composition, the total of epoxy groups. When the number is 1, the amount is preferably 1: 0.5 to 1: 1.1, and the ratio is more preferably 1: 0.5 to 1: 0.9. preferable. 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 reactive group ( The total number of active hydroxyl groups, active ester groups, etc.) is a value obtained by totaling the values obtained by dividing the solid content mass of each curing agent by the reactive group equivalent for all curing agents. By making content of a hardening | curing agent into this preferable range, the heat resistance of the hardened | cured material obtained by hardening | curing an epoxy resin composition will become favorable.

[Component (C) Phenoxy Resin and / or Polyvinyl Acetal Resin]
In the present invention, the phenoxy resin and / or the polyvinyl acetal resin is used for the purpose of imparting sufficient flexibility to the adhesive film and adjusting the roughening property. Specific examples of the phenoxy resin include FX280, FX293 manufactured by Toto Kasei Co., Ltd., YX8100, YX6954, YL6974 manufactured by Japan Epoxy Resin Co., Ltd., and the like. The polyvinyl acetal resin is not particularly limited, but 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 the phenoxy resin and / or polyvinyl acetal resin is preferably in the range of 2 to 20% by mass. By making it within the same range, sufficient flexibility is obtained, the handleability is good, and the peel strength of the conductor layer formed by plating is sufficient. On the other hand, if it exceeds 20% by mass, sufficient fluidity during lamination is difficult to obtain, and the roughness tends to be too large.

[Phosphorus-containing benzoxazine compound of component (D)]
The phosphorus-containing benzoxazine compound used in the present invention is particularly preferably a phosphorus-containing benzoxazine compound represented by the following formula (1) (see WO / 2008/010429).

This compound contains phosphorus and functions as a halogen-free flame retardant. Moreover, it has reactivity with an epoxy resin. Commercially available products include HF-BOZ06 (a dioxolane solution of a phosphorus-containing benzoxazine compound represented by formula (1)) and HFB-2006M (formula (1)) manufactured by Showa Polymer Co., Ltd. 1-methoxy-2-propanol solution of phosphorus-containing benzoxazine compound) and the like. 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 2 to 20% by mass, more preferably 2 to 10% by mass. %, Particularly preferably 3 to 6% by mass. By making content of a component (D) 2-20 mass%, the flame retardance and low hygroscopic property of hardened | cured material will improve.

  The epoxy resin composition of the present invention may further contain an inorganic filler for the purpose of reducing the coefficient of thermal expansion. 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 such as amorphous silica, fused silica, crystalline silica, and synthetic silica Particularly preferred. The silica is preferably spherical. 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 diameter exceeds 1 μm, the peel strength of the conductor layer formed by plating tends to decrease. 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 an epoxy silane coupling agent, an aminosilane coupling agent, or a titanate 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 blending the inorganic filler, the content in the epoxy resin composition (nonvolatile component 100% by mass) varies depending on the properties required for the resin composition, but is preferably 10 to 60% by mass, 15-50 mass% is more preferable, and 15-45 mass% is especially preferable.

  The epoxy resin composition of the present invention may contain solid rubber particles for the purpose of increasing the mechanical strength of the cured product and for the purpose of stress relaxation. The rubber particles in the present invention are not dissolved in an organic solvent when preparing an epoxy resin composition, and are not compatible with components in the resin composition such as an epoxy resin. Accordingly, the rubber particles in the present invention exist in a dispersed state in the varnish of the epoxy resin composition. Such rubber particles are generally prepared by increasing the molecular weight of the rubber component to a level at which it does not dissolve in an organic solvent or resin and making it into particles. Examples of the rubber particles include core-shell type rubber particles, cross-linked acrylonitrile butadiene rubber particles, cross-linked styrene butadiene rubber particles, and acrylic rubber particles. 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 acrylonitrile butadiene rubber (NBR) particles include XER-91 (average particle size 0.5 μm, manufactured by JSR Corporation). Specific examples of 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), W450A (average particle size 0.5 μm) (manufactured by Mitsubishi Rayon Co., Ltd.).

  The average particle size of the rubber particles to be blended is preferably in the range of 0.005 to 1 μm, and 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 using a dynamic light scattering method. For example, rubber particles are uniformly dispersed in a suitable organic solvent by ultrasonic waves, etc., and using FPRA-1000 (manufactured by Otsuka Electronics Co., Ltd.), the particle size distribution of the rubber particles is created on a mass basis, and the median diameter is determined. The average particle size can be measured.

  When the rubber particles are blended, the content in the epoxy resin composition (nonvolatile content: 100% by mass) is preferably from 1 to 10% by mass, and 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. Examples of the curing accelerator include organic phosphine compounds, imidazole compounds, amine adduct compounds, tertiary amine compounds, and the like. Specific examples of the organic phosphine compound include triphenylphosphine (trade name TPP), tetraphenylphosphonium tetraphenylborate (trade name TPP-K), triphenylphosphine triphenylborane (trade name TPP-S), and tri-p-. There may be mentioned tolylphosphine (TPTP-S) or more, manufactured by Hokuko Chemical Co., Ltd. Specific examples of the imidazole compound include 2-methylimidazole (trade name: Curazole 2MZ), 2-ethyl-4-methylimidazole (trade name: 2E4MZ), 2-undecylimidazole (trade name: C11Z), 1-cyanoethyl-2- Undecylimidazole (trade name C11Z-CN), 1-cyanoethyl-2-undecylimidazolium trimellitate (trade name C11Z-CNS), 2,4-diamino-6- [2'-undecylimidazolyl- (1 ')]-Ethyl-s-triazine (trade name C11Z-A), 2MZ-OK, 2,4-diamino-6- [2'-methylimidazolyl- (1')]-ethyl-s-triazine isocyanuric acid addition Product (trade name 2MA-OK, 2-phenyl-4,5-dihydroxymethylimidazole (trade name 2PH ), Shikoku Kasei Kogyo Co., Ltd., etc. Specific examples of amine adduct compounds 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-diazabicero [5,4,0] undec-7-ene), etc. In the epoxy resin composition of the present invention, The content is usually in the range of 0.1 to 5% by mass when the total amount of the epoxy resin and the phenolic curing agent contained in the epoxy resin composition is 100% by mass (nonvolatile content).

  The epoxy resin composition of the present invention may contain a flame retardant other than the component (D) as long as the curing of the present invention is not impaired. Examples of the flame retardant include an organic phosphorus flame retardant, an organic nitrogen-containing phosphorus compound, a nitrogen compound, a silicone flame retardant, and a metal hydroxide.

  The epoxy resin composition of the present invention may contain other resins than those described above as long as the effects of the present invention are exhibited. Examples of other resins include cyanate ester resins, polyimide resins, polyamideimide resins, polyethersulfone resins, and polysulfone resins.

  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, triazole, and silane coupling agents, and coloring agents such as phthalocyanine / blue, phthalocyanine / green, iodin / green, disazo yellow, and carbon black.

  The 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 is contained in a sheet-like fiber substrate made of fibers. It can be impregnated to form a prepreg for an interlayer insulating layer of a multilayer printed wiring 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 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. , Aromatic hydrocarbons such as toluene and xylene, amide solvents such as dimethylformamide, dimethylacetamide, and N-methylpyrrolidone. One organic solvent may be used, or 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. As drying conditions, suitable drying conditions can be appropriately set by simple experiments. 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.

  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.

  As the support film and protective film in the present invention, polyolefin films such as polyethylene, polypropylene and polyvinyl chloride, polyethylene terephthalate (hereinafter sometimes abbreviated as “PET”), polyester films such as polyethylene naphthalate, polycarbonate Examples thereof include films, polyimide films, and metal foils such as release paper, copper foil, and aluminum foil. In addition, the support film and the protective film may be subjected to a release treatment in addition to the mat 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 also 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 inner layer circuit board in the present invention is mainly a conductor 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, etc. The one formed by. In addition, when manufacturing a multilayer printed wiring board in which conductor layers and insulating layers are alternately formed, and one or both surfaces are patterned conductor layers (circuits), an insulating layer and a conductor layer are further formed. The intermediate product to be included is also included in the inner layer circuit board in the present invention. In the inner layer circuit board, the surface of the conductor circuit layer is preferably roughened by a blackening process or the like from the viewpoint of adhesion of the insulating layer to the inner layer 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 preferably 0.5 μm or less in terms of Ra when forming fine wiring. The Ra value is a kind of numerical value representing the surface roughness, and is called arithmetic average roughness. Specifically, the absolute value of the height changing in the measurement region is determined from the surface that is the average line. Measured and arithmetically averaged. For example, using WYKO NT3300 manufactured by Becoin Instruments Co., Ltd., it can be obtained from a numerical value obtained with a measurement range of 121 μm × 92 μm using a VSI contact mode and a 50 × lens.

  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. 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. The peel strength of the conductor layer is preferably 0.6 kgf / cm or more.

  In addition, as a method of forming a circuit by patterning a conductor layer, for example, a subtractive method known to those skilled in the art (a method of forming a circuit by removing unnecessary portions from a substrate with copper foil stretched over the entire surface) A semi-additive method (a method of adding a circuit pattern to an insulating substrate later) or the like 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 fiber 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 fiber base material which consists of fibers.

  As the sheet-like fiber base material composed of fibers, for example, glass cloth and aramid fibers, which are commonly used as prepreg 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 fiber 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 fiber base material is immersed in a resin varnish obtained by dissolving a resin in an organic solvent, the resin varnish is impregnated into the sheet-like fiber 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 ), preferably the temperature is 120 to 200 ° C., and the time is 20 to 100 minutes. preferable. 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, in the same manner as described above, the surface of the prepreg cured with an oxidizing agent is roughened, and then the conductor layer is formed by plating, whereby a multilayer printed wiring board can be manufactured.

EXAMPLES Hereinafter, although this invention is demonstrated in detail using an Example and a comparative example, these do not restrict | limit this invention in any meaning. In the following description, “part” means “part by mass”.
<Example 1>

30 parts of liquid bisphenol A type epoxy resin (epoxy equivalent 180, “Epicoat 828EL” manufactured by Japan Epoxy Resin Co., Ltd.) and 30 parts biphenyl type epoxy resin (epoxy equivalent 291; “NC3000H” manufactured by Nippon Kayaku Co., Ltd.) Was dissolved in 15 parts of methyl ethyl ketone (hereinafter abbreviated as “MEK”) and 15 parts of cyclohexanone with stirring. Thereto, 100 parts of a 50% solid MEK solution of a naphthol curing agent (“SN485” manufactured by Tohto Kasei Co., Ltd., phenolic hydroxyl group equivalent 215), a curing catalyst (“2E4MZ” manufactured by Shikoku Kasei Kogyo Co., Ltd.) 0.1 part, spherical silica (average particle size 0.5 μm, “amino-silane treated“ SO-C2 ”manufactured by Admatex) 70 parts, polyvinyl butyral resin solution (glass transition temperature 105 ° C., Sekisui Chemical Co., Ltd.) "KS-1"): 20 parts of a 15% solid ethanol / toluene 1: 1 solution), phenoxy resin (molecular weight 38,000, Japan Epoxy Resin Co., Ltd. "YX6954" MEK with a nonvolatile content of 30% by mass And cyclohexanone (1: 1 solution) 20 parts, phosphorus-containing benzoxazine represented by formula (1) (HF-BOZ06 manufactured by Showa Polymer Co., Ltd., solid content 65% Oxolane solution) 8 parts were mixed, and uniformly dispersed in a high-speed rotary mixer to prepare a resin varnish. Next, the resin varnish was applied on a polyethylene terephthalate film (thickness 38 μm) with a die coater so that the resin thickness after drying was 40 μm, and dried at 80 to 120 ° C. (average 100 ° C.) for 6 minutes. (Residual solvent amount of about 2% 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.
<Example 2>

  30 parts of liquid bisphenol A type epoxy resin (epoxy equivalent 180, “Epicoat 828EL” manufactured by Japan Epoxy Resin Co., Ltd.) and 30 parts biphenyl type epoxy resin (epoxy equivalent 291; “NC3000H” manufactured by Nippon Kayaku Co., Ltd.) Was dissolved in 15 parts of MEK and 15 parts of cyclohexanone with stirring. There, 80 parts of MEK solution of 50% solid content of naphthol type curing agent (“SN485” manufactured by Tohto Kasei Co., Ltd., phenolic hydroxyl group equivalent 215), active ester type curing agent (Dainippon Ink Chemical Co., Ltd.) "EXB9451", 15 parts of an active group equivalent of 223 toluene solution with a solid content of 65 mass%, 0.1 part of a curing catalyst (manufactured by Shikoku Chemicals Co., Ltd., "2E4MZ"), spherical silica (average particle size 0. 5 μm, 70 parts of “SO-C2” with aminosilane treatment (manufactured by Admatechs), polyvinyl butyral resin solution (glass transition temperature 105 ° C., “KS-1” manufactured by Sekisui Chemical Co., Ltd.) with a solid content of 15% 20 parts of a 1: 1 solution of ethanol and toluene, phenoxy resin (molecular weight 38,000, "YX6954" manufactured by Japan Epoxy Resin Co., Ltd.) MEK and Siku with a nonvolatile content of 30% by mass 20 parts of hexanone (1: 1 solution) and 15 parts of phosphorus-containing benzoxazine represented by the formula (1) (Showa Polymer Co., Ltd. HF-BOZ06, solid content 65% dioxolane solution) are mixed and rotated at high speed. A resin varnish was prepared by uniformly dispersing with a mixer. Next, using this resin varnish, an adhesive film was obtained in the same manner as in Example 1.

<Comparative Example 1>
In the resin varnish described in Example 1, an adhesive film was obtained in exactly the same manner except that 8 parts of phosphorus-containing benzoxazine (HF-BOZ06 manufactured by Showa Polymer Co., Ltd., dioxolane solution having a solid content of 65%) was not added. It was.

<Comparative example 2>
30 parts of liquid bisphenol A type epoxy resin (epoxy equivalent 180, “Epicoat 828EL” manufactured by Japan Epoxy Resin Co., Ltd.) and 30 parts of phosphorus-containing epoxy resin (epoxy equivalent 306, “FX289” manufactured by Tohto Kasei Co., Ltd.) It was heated and dissolved in 15 parts of MEK and 15 parts of cyclohexanone with stirring. Thereto, 100 parts of a 50% solid MEK solution of a naphthol-based curing agent (“SN-485” manufactured by Tohto Kasei Co., Ltd., phenolic hydroxyl group equivalent 215), a curing catalyst (manufactured by Shikoku Chemicals Co., Ltd., “2E4MZ”) ”) 0.1 part, spherical silica (average particle diameter 0.5 μm,“ SO-C2 with aminosilane treatment ”manufactured by Admatechs Co., Ltd.), polyvinyl butyral resin solution (glass transition temperature 105 ° C., Sekisui Chemical Co., Ltd.) "KS-1"), 15 parts solid solution of ethanol and toluene (1: 1), 20 parts, phenoxy resin (molecular weight 38,000, Japan Epoxy Resin "YX6954" non-volatile content 30% by mass 20 parts of MEK and cyclohexanone (1: 1 solution) were mixed and dispersed uniformly with a high-speed rotary mixer to prepare a resin varnish. Next, using this resin varnish, an adhesive film was obtained in 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., dioxolane solution having a solid content of 65%) was added to a phosphorus flame retardant (HCA-HQ manufactured by Sanko Co., Ltd.). -HS) Except for changing to 8 parts, an adhesive film was obtained in exactly the same manner.

<Preparation of peel strength and Ra value measurement sample>
(1) Substrate treatment of laminated board Both sides of glass cloth base epoxy resin double-sided copper-clad laminate [copper foil thickness 18 μm, substrate thickness 0.3 mm, Matsushita Electric Works R5715ES] on which inner layer circuit is formed are organic The copper surface was roughened by dipping in an acid-based etching agent (CZ8100, manufactured by MEC Co., Ltd.).

(2) Lamination of adhesive film The adhesive films prepared in Examples and Comparative Examples were laminated on both surfaces of a laminate using a batch-type vacuum pressurization laminator MVLP-500 (trade name of 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 100 ° C. and 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 immersed in a swelling dip secu-ligand P containing diethylene glycol monobutyl ether of Atotech Japan Co., Ltd., which is a swelling liquid, and then the outlet of Atotech Japan Co., Ltd. as a roughening liquid. Immerse in rate compact P (KMnO ₄ : 60 g / L, NaOH: 40 g / L aqueous solution) and finally neutralize it with Atotech Japan Co., Ltd. Reduction Sholyshin Securigant P at 40 ° C. for 5 minutes. Soaked. 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. About the laminated board after this roughening process, the surface roughness (Ra value) was measured.

(5) Plating by semi-additive method In order to form a circuit on the surface of the insulating layer, 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, an etching resist was formed, and after pattern formation by etching, copper sulfate electrolytic plating was performed to form a conductor layer with a thickness of 30 ± 5 μm. Next, annealing was performed at 180 ° C. for 60 minutes. The peel strength of the plated copper was measured for this laminate.

<Measurement of peel strength (peel strength) of plated conductor layer>
Cut the 10mm width and 100mm length into the conductor layer of the laminate, peel off one end of the laminate and grasp it with a gripper, at a speed of 50mm / min at room temperature, approximately perpendicular to the laminate The load when peeling 35 mm was measured.

<Measurement of surface roughness (Ra value) after roughening>
Using a non-contact type surface roughness meter (BYCO Instruments WYKO NT3300), the Ra value was determined by a numerical value obtained by setting the measurement range to 121 μm × 92 μm with a VSI contact mode and a 50 × lens. Moreover, it measured by calculating | requiring the average roughness of 10 points | pieces.

<Preparation of flame retardant test sample>
(1) Substrate treatment of laminated plate Adhesive films prepared in Examples and Comparative Examples on both surfaces of glass cloth base epoxy resin laminated plate [copper foil etched-out product, substrate thickness 0.3 mm, Matsushita Electric Works, Ltd. R5715ES] Was laminated on both surfaces of the laminate using a batch type vacuum pressure laminator MVLP-500 (trade name of 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 100 ° C. and a pressure of 0.74 Mpa for 30 seconds. After peeling the PET film from the laminated adhesive film, the same adhesive film was further laminated twice under the same conditions.

(2) Curing of resin composition The PET film was peeled off from the finally laminated adhesive film, and the resin composition was cured under curing conditions at 180 ° C for 90 minutes. After that, it was cut into a size of 12.7 mm × 127 mm for the UL flame retardancy test, and the end surface was polished with sandpaper (first # 1200, then # 2800), and the substrate thickness was 0.3 mm on one side. A test piece for flammability test in which an insulating layer of 120 μm was laminated was produced. Thereafter, 94V0 or 94V1 was evaluated according to the UL flame resistance test standard.

  The results of the peel strength and the roughened surface roughness (Ra value) of the plated conductor layers of the evaluation samples using the adhesive films obtained in Examples and Comparative Examples are shown in Table 1 below. As is clear from Table 1, the evaluation sample of the example using the phosphorus-containing benzoxazine compound in the present invention had a low roughness and a high peel strength, and the flame retardancy was excellent at V0. Moreover, in the case of the comparative example 1 which does not use a phosphorus containing benzoxazine compound, although the peel strength was comparatively high, it was inferior to a flame retardance and resulted in a large roughness. Further, in the case of Comparative Examples 2 and 3 in which another phosphorus-containing compound is used instead of the phosphorus-containing benzoxazine compound in the present invention, the flame resistance is equivalent and the peel strength is relatively high, but such a high peel strength In order to obtain the result, the roughness was increased.

  The resin composition of the present invention, the adhesive film prepared by the resin composition, and the prepreg are suitably used as an interlayer insulating material for multilayer printed wiring boards, particularly multilayer printed wiring boards manufactured by a build-up method.

  This application is based on Japanese Patent Application No. 2007-245801 filed in Japan, the contents of which are incorporated in full herein.

Claims (12)

An epoxy resin composition comprising (A) an epoxy resin, (B) an epoxy curing agent, (C) a phenoxy resin and / or a polyvinyl acetal resin, and (D) a phosphorus-containing benzoxazine compound ,
The epoxy resin composition, wherein the (D) phosphorus-containing benzoxazine compound is a phosphorus-containing benzoxazine compound represented by the following formula (1) .
Epoxy curing agents, phenolic curing agent, an epoxy curing agent comprising one or more selected from naphthol type curing agent and active ester-based curing agent, according to claim 1 Symbol placement of the epoxy resin composition. When the nonvolatile component of the epoxy resin composition is 100% by mass, the content of the component (A) is 10 to 50% by mass, the content of the component (C) is 2 to 20% by mass, and the content of the component (D) the amount is 2 to 20 wt%, the ratio of the reactive groups of the epoxy curing agent to 1 epoxy groups present in the epoxy resin composition is 1: 0.5 to 1: 1.1, according to claim 1 or 2. The epoxy resin composition according to 2. Furthermore, the epoxy resin composition of any one of Claims 1-3 containing an inorganic filler. The epoxy resin composition of Claim 4 whose content of an inorganic filler is 10-60 mass% when the non-volatile component of an epoxy resin composition is 100 mass%. The adhesive film by which the epoxy resin composition of any one of Claims 1-5 is layer-formed on the support film. A prepreg characterized in that the epoxy resin composition according to any one of claims 1 to 5 is impregnated in a sheet-like fiber base material comprising fibers. The multilayer printed wiring board with which the insulating layer is formed with the hardened | cured material of the epoxy resin composition of any one of Claims 1-5 . It is a manufacturing method of a 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, and this insulating layer is any one of Claims 1-5. A multilayer printed wiring board, wherein the epoxy resin composition according to the item is heat-cured and the conductor layer is formed by plating on a roughened surface obtained by roughening the surface of the insulating layer. Production method. 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 forming step, the roughening step of the insulating layer, And an insulating layer forming step comprising laminating an adhesive film formed on the support film according to claim 6 on the inner circuit board, and an epoxy resin composition. A method for producing a multilayer printed wiring board, comprising the step of heat curing.   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, the insulating layer comprising the prepreg according to claim 7 as an inner layer circuit board. A multilayer printed wiring board characterized in that it is formed by laminating and thermosetting an epoxy resin composition, and the conductor layer is formed by plating on a roughened surface obtained by roughening the surface of the insulating layer. Manufacturing method. The method for producing a multilayer printed wiring board according to any one of claims 9 to 11 , wherein the roughening treatment is performed using an alkaline permanganate solution.