JP2010077263A - Epoxy resin composition for prepreg, prepreg, and multilayer printed wiring board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a halogen-free epoxy resin composition for prepregs excellent in flame retardancy and heat resistance, a prepreg, and a multilayer printed wiring board. <P>SOLUTION: The epoxy resin composition for pregregs includes an epoxy resin (A) containing two or more phenyl skeletons in the molecule, a phosphorus-containing epoxy resin (B) obtained by reacting an organic phosphorus compound of a reaction product of at least one selected from phosphorus compounds represented by formula (I) and formula (II) and a quinone compound with an epoxy resin, a phosphorus-containing phenoxy resin (C), and a phenolic curing agent (D) with a phosphorus content of 0.5-1.5 mass% based on the solid content of the epoxy resin composition for prepregs. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an epoxy resin composition for prepreg, a prepreg, and a multilayer printed wiring board.

  In recent years, a build-up wiring board in which organic insulating layers are alternately stacked on a conductor of an inner circuit board has attracted attention as a multilayer printed wiring board. Among them, as described in Patent Documents 1 and 2, an epoxy resin composition is applied to an inner circuit board on which a circuit has been formed, and after heating and curing, a roughened surface having irregularities with a roughening solution containing an oxidizing agent or the like is provided. A build-up wiring board that is formed on the surface and uses a technique of forming a conductor layer on the roughened surface by plating is particularly attracting attention because a fine circuit can be formed.

On the other hand, in recent years, in order to reduce the burden on the environment, it does not contain halogen-based flame retardants that may occur during combustion of compounds that adversely affect the human body, such as polybrominated dibenzodioxin, and lead-free solder The organic insulating layer is required to have heat resistance that can be utilized.
Japanese Patent No. 3290295 Japanese Patent No. 3290296

  However, in the organic insulating layer as described above which can form a rough surface with irregularities on the surface with a roughening solution containing an oxidizing agent, etc., halogen-free flame resistance and heat resistance that can use lead-free solder There was a problem that a product satisfying both of the characteristics was not obtained.

  The present invention has been made in view of the circumstances as described above, and has excellent irregularity formation and plating adhesion to the surface by a roughening solution containing an oxidizer and the like, and further has flame retardancy and heat resistance. Another object of the present invention is to provide a halogen-free epoxy resin composition for prepreg, a prepreg, and a multilayer printed wiring board using these.

  The present invention is characterized by the following in order to solve the above problems.

  1stly, the epoxy resin composition for prepregs of this invention is the epoxy resin (A) which contains two or more phenyl frame | skeletons in 1 molecule, and following formula (I) or Formula (II):

(In the formula, each R independently represents a hydrocarbon group having 1 to 6 carbon atoms, and n represents an integer of 0 to 4). A reaction product of at least one selected from phosphorus compounds represented by A phosphorus-containing epoxy resin (B) obtained by reacting an organic phosphorus compound and an epoxy resin, a phosphorus-containing phenoxy resin (C) having a weight average molecular weight of 30,000 to 80,000, and a phenol-based curing agent (D) And the phosphorus content is 0.5 to 1.5% by mass with respect to the solid content of the epoxy resin composition for prepreg.

  Second, in the first epoxy resin composition for a prepreg, the epoxy resin (A) containing two or more phenyl skeletons in one molecule is a crude product containing one or both of an oxidizing agent and an acid. It is characterized by being harder to decompose or dissolve than the cured product of the phosphorus-containing epoxy resin (B) and the cured product of the phosphorus-containing phenoxy resin (C).

  Thirdly, in the first or second prepreg epoxy resin composition, the phosphorus-containing phenoxy resin (C) includes bisphenol A, an epoxy resin, and the following formula (III) or formula (IV):

It is obtained by reacting with a phosphorus compound represented by the formula:

  Fourthly, the prepreg of the present invention is obtained by impregnating a substrate with one of the first to third epoxy resin compositions for prepreg and drying it.

  Fifth, in the multilayer printed wiring board of the present invention, an insulating layer is formed by prepreg by laminating the fourth prepreg on an inner circuit board on which a circuit has been previously formed, and the surface of the insulating layer is oxidized with an oxidant. In addition, a conductor layer is formed by plating on the roughened surface after roughening with a roughening solution containing one or both of acid and acid, and an outer layer circuit is formed by this conductor layer.

  According to the first invention, the phosphorus-containing phenoxy resin (C) is contained as an essential component. The phosphorus-containing phenoxy resin (C) is hardly compatible with the epoxy resin (A) containing two or more phenyl skeletons in one molecule and the phosphorus-containing epoxy resin (B), and is uniformly dispersed in the cured state. And phosphorus containing phenoxy resin (C) is decomposed | disassembled or melt | dissolved with respect to the roughening solution containing an oxidizing agent etc. rather than the epoxy resin (A) and phosphorus containing epoxy resin (B) which contain two or more phenyl frame | skeletons in 1 molecule. Since it is easy, the roughened surface which has a uniform and precise unevenness | corrugation can be formed in the surface of a prepreg, and as a result, metal-plating adhesiveness can also be made favorable.

  In addition, it contains an epoxy resin (A) containing two or more phenyl skeletons in one molecule, a phosphorus-containing epoxy resin (B), a phosphorus-containing phenoxy resin (C), and a phenol-based curing agent (D) as essential components. In addition, since the phosphorus content is within the above specific range, it is excellent in flame retardancy and heat resistance.

  According to the second aspect of the present invention, as an epoxy resin (A) containing two or more phenyl skeletons in one molecule, a phosphorus-containing epoxy resin (B) with respect to a roughening solution whose cured product contains an oxidizing agent or the like The hardened | cured material and the thing harder to decompose | disassemble or melt | dissolve than the hardened | cured material of phosphorus containing phenoxy resin (C) are used. Therefore, the difference in decomposition and solubility in the roughening solution between the phosphorus-containing phenoxy resin (C) and the epoxy resin (A) containing two or more phenyl skeletons in one molecule and the phosphorus-containing epoxy resin (B), Both the difference in decomposition and solubility in the roughening solution between the epoxy resin (A) containing two or more phenyl skeletons in one molecule and the phosphorus-containing epoxy resin (B) and the phosphorus-containing phenoxy resin (C) It works effectively to form uniform and dense irregularities on the surface of the prepreg. Therefore, in addition to the effect of the first invention, the plating adhesion can be further improved.

  According to the third aspect of the invention, since the specific one described above is used as the phosphorus-containing phenoxy resin (C), in addition to the effects of the first and second aspects, a roughened surface having more uniform unevenness. Can be formed on the surface of the prepreg, and as a result, the plating adhesion can be further improved.

  According to the fourth aspect of the invention, since the epoxy resin composition for prepreg of the first to third aspects of the invention is used, a roughened surface having uniform and precise irregularities can be formed on the surface of the prepreg. As a result, the plating adhesion can be further improved. It also has excellent flame resistance and heat resistance.

  According to the fifth invention, since the insulating layer is formed using the prepreg of the fourth invention, the adhesion of the outer layer circuit formed by plating the surface of the insulating layer is good, It also has excellent flame resistance and heat resistance.

  Hereinafter, the present invention will be described in detail.

  The epoxy resin (A) containing two or more phenyl skeletons in one molecule used in the present invention is a bifunctional epoxy resin or a polyfunctional epoxy resin having three or more epoxy groups in one molecule. As naphthalene type epoxy resin, biphenyl type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, phenol novolac type epoxy resin, alkylphenol novolac type epoxy resin, dicyclopentadiene type epoxy resin, etc. Is mentioned. These may be used alone or in combination of two or more.

  Among them, it is preferable to use a cured product that is less decomposed or dissolved than a cured product of a phosphorus-containing epoxy resin (B) and a cured product of a phosphorus-containing phenoxy resin (C) with respect to a roughening solution containing an oxidizing agent or the like. Preferably, examples of such an epoxy resin (A) include those having an epoxy equivalent of 200 or less, particularly naphthalene type epoxy resins and biphenyl type epoxy resins having a high phenyl skeleton ratio in the molecule. By using such an epoxy resin (A), the difference in decomposition / solubility in the roughening solution between the epoxy resin (A), the phosphorus-containing epoxy resin (B), and the phosphorus-containing phenoxy resin (C) is prepreg. This effectively acts on the surface irregularity-forming property of the surface and can improve the plating adhesion.

  The phosphorus-containing epoxy resin (B) used in the present invention is an organic phosphorus compound that is a reaction product of at least one selected from the phosphorus compounds represented by the formula (I) or the formula (II) and a quinone compound, It is obtained by reacting with an epoxy resin.

  In the above formulas (I) and (II), each R independently represents a hydrocarbon group having 1 to 6 carbon atoms, preferably a linear or branched alkyl group having 1 to 6 carbon atoms. n shows the integer of 0-4.

  By using phosphorus compounds of the above formulas (I) and (II) having active hydrogen bonded to a phosphorus atom as the phosphorus compound used as a raw material of the organic phosphorus compound, it is difficult to use a halogen compound containing bromine element or the like. Flammability can be improved. Furthermore, the organophosphorus compound synthesized by reacting this with a quinone compound can react with an epoxy resin to reliably produce a phosphorus-containing epoxy resin (B).

  Specific examples of the quinone compound that is a raw material for the organic phosphorus compound include 1,4-benzoquinone, 1,2-benzoquinone, tolquinone, 1,4-naphthoquinone, and the like. These may be used alone or in combination of two or more.

  As an epoxy resin used as a raw material for the phosphorus-containing epoxy resin (B), a novolac type epoxy resin is preferably used. The novolac type epoxy resin is preferably blended at a ratio of 20% by mass or more (upper limit is 100% by mass) of the total amount of the epoxy resin. When the amount of the novolac type epoxy resin is less than 20% by mass, it may be difficult to impart flame retardancy, and heat resistance may be deteriorated. When the epoxy resin is a mixture containing a novolac type epoxy resin as a whole, specific examples of the epoxy resin other than the novolac type epoxy resin include those having two or more epoxy groups in one molecule, for example, a bisphenol type epoxy resin, Resorcinol type epoxy resin, polyglycol type epoxy resin, fluorene type epoxy resin and the like can be mentioned.

  The phosphorus-containing epoxy resin (B) is obtained by, for example, reacting the phosphorus compound and quinone compound of the above formula (I) or formula (II) in a solvent such as toluene to obtain an organic phosphorus compound, and then mixing with the epoxy resin. It can be obtained by adding a curing accelerator such as triphenylphosphine and reacting the organophosphorus compound with the epoxy resin.

  The phosphorus-containing phenoxy resin (C) used in the present invention has a weight average molecular weight in the range of 30,000 to 80,000. When the weight average molecular weight is less than 30,000, it is easily compatible with the epoxy resin (A) or the phosphorus-containing epoxy resin (B) containing two or more phenyl skeletons in one molecule, and in the cured state, the phosphorus-containing phenoxy resin ( C) may not be uniformly dispersed and plating adhesion may be reduced. On the other hand, when the weight average molecular weight exceeds 80,000, it is almost incompatible with the epoxy resin (A) or the phosphorus-containing epoxy resin (B) containing two or more phenyl skeletons in one molecule, and is plated because it is dispersed unevenly. Adhesion may be reduced.

  As phosphorus containing phenoxy resin (C), what introduce | transduced the phosphorus compound into phenoxy resin can be used. The phenoxy resin used as the raw material for the phosphorus-containing phenoxy resin (C) can be synthesized from bisphenols and epihalohydrin. Alternatively, it can be synthesized by an addition polymerization reaction between a phenolic epoxy resin and a bisphenol. Specific examples of the bisphenols used as the raw material for the phenoxy resin include bisphenol A, bisphenol F, 3,4,5,6-dibenzo-1,2-oxaphosphan-2-oxide hydroquinone, and the like. These may be used alone or in combination of two or more, and may be a copolymerized phenoxy resin. In addition, when bisphenol S is used as a raw material for the phenoxy resin, it is preferable to use bisphenol A or the like that does not contain an S element from the viewpoint of drilling because it contains an S element and easily causes corrosion wear.

  Examples of the method for introducing the phosphorus compound into the phenoxy resin include a method in which the phosphorus compound is reacted with the remaining epoxy group and a method in which the phosphorus compound is introduced into the main chain by copolymerization.

  As the phosphorus compound used in the method of introducing the phosphorus compound into the terminal residual epoxy group, from the point that the phosphorus content becomes high and flame retardancy can be imparted, 3, 4, and 4 represented by the formula (III) 5,6-dibenzo-1,2-oxaphosphane-2-oxide is preferred.

  As the phosphorus compound used in the method of introducing the phosphorus compound into the main chain by copolymerization, from the point that the phosphorus content becomes high and flame retardancy can be imparted, 3, 4, and 4 represented by the formula (IV) 5,6-dibenzo-1,2-oxaphosphan-2-oxide hydroquinone is preferred.

  Specific examples of the phenolic curing agent (D) used in the present invention include phenol novolac resins, alkylphenol novolac resins, bisphenol A novolac resins, dicyclopentadiene type phenol resins and the like. These may be used alone or in combination of two or more. Dicyandiamide is often used as the curing agent for the epoxy resin, but the heat resistance of the cured product is low, and in consideration of the use of lead-free solder, it is appropriate to use the phenolic curing agent (D).

  The epoxy resin composition for prepreg of the present invention can be blended with other components within the range not impairing the effects of the present invention. Specific examples of such other components include curing accelerators such as tertiary amines and imidazoles. Moreover, you may prepare the epoxy resin composition for prepregs of this invention as a varnish by diluting with a solvent.

  The epoxy resin composition for prepregs of the present invention has a phosphorus content of 0.5 to 1.5% by mass with respect to the solid content of the epoxy resin composition for prepregs. By setting the phosphorus content within the range, sufficient flame retardancy can be ensured without using a halogen compound, and heat resistance can be improved by suppressing hygroscopicity. If the phosphorus content is less than 0.5% by mass, sufficient flame retardancy may not be obtained. On the other hand, if the phosphorus content exceeds 1.5% by mass, the hygroscopicity or heat resistance of the molded product may be lowered.

  When producing the prepreg of the present invention, the above prepreg epoxy resin composition is prepared as a varnish, and this varnish is impregnated into a base material, for example, at a temperature of about 120 to 190 ° C. in a drier. By drying this substrate for about 15 minutes, a prepreg in a semi-cured state (B-stage) can be produced.

  As the base material, craft paper, natural fiber cloth, organic synthetic fiber cloth and the like can be used in addition to glass fiber cloth such as glass cloth, glass paper and glass mat.

  A required number of the prepregs obtained as described above are stacked, for example, by heating and pressing under conditions of 140 to 200 ° C. and 0.98 to 4.9 MPa, and a laminate can be produced. .

  At this time, a metal-clad laminate can be produced by stacking a metal foil on one side or both sides of a required number of prepregs and laminating the prepreg and the metal foil together by heating and pressing. As the metal foil, copper foil, silver foil, aluminum foil, stainless steel foil or the like can be used.

  Next, a method for producing a printed wiring board using the prepreg produced as described above and a metal foil-clad laminate will be described with reference to FIG.

  FIG. 1 shows an example of a method for producing a printed wiring board in the order of steps. In this method, first, as shown in FIG. 1A, an inner layer circuit is formed in advance on a metal-clad laminate. One surface of the prepreg 2 is superposed on the surface of the inner layer circuit board 1 and the release material 3 is superposed on the other surface of the prepreg 2 and laminated and formed using a multistage vacuum press or the like.

  In FIG. 1A, the prepreg 2 is laminated and molded on both sides of the inner layer circuit board 1, but the prepreg 2 may be laminated and molded only on one side of the inner layer circuit board 1. Further, before the prepreg 2 is overlaid, the inner layer circuit of the inner layer circuit board 1 may be subjected to inner layer roughening treatment such as black oxidation treatment (blackening treatment).

  As a laminate constituting the metal-clad laminate used for the inner layer circuit board 1, for example, a laminate obtained by laminating a required number of the prepregs of the present invention, a commercially available glass epoxy laminate, a polyimide laminate, A thermosetting polyphenylene ether laminate or the like can be used.

  As the mold release material 3, for example, a copper foil, a silver foil, an aluminum foil, a stainless steel foil, a polyolefin film such as polyethylene or polyvinyl chloride, a polyester film such as polyethylene terephthalate, or the like can be used.

  Then, from the state of FIG. 1B after the lamination molding, the release material 3 is removed as shown in FIG. 1C, thereby exposing the insulating layer 4 to be subjected to the next roughening treatment.

  Next, as shown in FIG. 1D, the insulating layer 4 is roughened. If necessary, the laminated molded product is subjected to necessary processing such as forming via holes 7 by laser via processing or the like.

  The roughening treatment of the insulating layer 4 is performed with a roughening solution. The roughening solution is not particularly limited as long as it contains one or both of an oxidizing agent and an acid. For example, Rohm and Haas “Circuposit MLB Conditioner”, Rohm and Haas “Circuposit MLB Promoter”, Rohm and Haas “Circuposit MLB Neutralizer” as a set roughening solution Can also be used.

  The “circuposit MLB conditioner” is a solution that activates a resin to bring it into an optimum state for the subsequent circular deposit MLB promoter process.

  The above "circuposit MLB promoter" is a solution having a function of dissolving a resin, particularly a phosphorus-containing epoxy resin (B) and a phosphorus-containing phenoxy resin (C). A potassium permanganate aqueous solution (oxidant) and potassium hydroxide It is mainly composed of an aqueous solution.

  Permanganates such as potassium permanganate act as strong oxidants under basic conditions. As another specific example of the solution having a function of dissolving the resin, a solution containing sodium permanganate aqueous solution (oxidant) and sodium hydroxide aqueous solution as main components can be given.

  The above-mentioned “circuposit MLB neutralizer” is a solution having a function for neutralizing a basic state, and is mainly composed of a sulfuric acid aqueous solution (acid) and a hydrogen peroxide aqueous solution.

  The roughening treatment with the roughening solution can be performed by immersing the laminated molded product shown in FIG. 1C in the roughening solution, and can be performed a plurality of times by changing the type of the roughening solution. For example, the temperature of the roughening solution can be set to 35 to 90 ° C., and the immersion time can be set to 1 to 30 minutes.

  Since the insulating layer 4 formed of the prepreg 2 includes a component that is easily dissolved in the roughening solution and a component that is difficult to dissolve, when the roughening treatment is performed, the easily soluble component is dissolved in the roughening solution, Thereby, dense irregularities can be formed on the surface of the insulating layer 4 as shown in FIG.

  Thereafter, as shown in FIG. 1 (e), the surface of the roughened insulating layer 4 is plated 5, and then an outer layer circuit 6 is formed as shown in FIG. A board can be obtained.

  As a method of forming the outer layer circuit 6 by the plating 5, a method of forming a circuit by a subtractive method after panel plating is performed on the surface of the insulating layer 4, a method of forming a circuit by a semi-additive method, and a circuit by a full additive method And the like.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these Examples at all. In addition, the compounding quantity of Table 1 shows a mass part.

The following were used as a compounding component of the epoxy resin composition for prepregs.
(1) Epoxy resin containing two or more phenyl skeletons in one molecule (A)
Naphthalene type epoxy resin (manufactured by DIC Corporation, HP-4032), biphenyl type epoxy resin (manufactured by Japan Epoxy Resin Corporation, YX-4000H), phenol novolac type epoxy resin (manufactured by DIC Corporation, EPICRON N-770) ) Was used.
(2) Phosphorus-containing epoxy resin (B)
To a four-necked glass separable flask equipped with a stirrer, thermometer, condenser, and nitrogen gas inlet, 3,4,5,6-dibenzo-1,2-oxaphosphane-2-oxide (Sanko) 155 parts by mass of HCA, phosphorus compound represented by formula (III), phosphorus content of about 14.3% by mass) and 330 parts by mass of toluene were prepared and heated to dissolve.

  Thereafter, 99.0 parts by mass of 1,4-naphthoquinone (manufactured by Kawasaki Kasei Kogyo Co., Ltd.) was dividedly added to synthesize an organic phosphorus compound. At this time, the molar ratio was 1,4-naphthoquinone / phosphorus compound of formula (III) = 0.87.

After completion of the reaction, 746.0 parts by mass of a phenol novolac type epoxy resin (Etoto YDPN-638, manufactured by Toto Kasei Co., Ltd.) was charged, stirred while introducing nitrogen gas, and heated to 120 ° C. for dissolution. Further, triphenylphosphine was added and reacted at 150 ° C. for 4 hours. The phosphorus-containing epoxy resin (B) thus obtained had an epoxy equivalent of 360.3 g / eq and a phosphorus content of 2.2% by mass.
(3-1) Phosphorus-containing phenoxy resin (C)
251.7 parts by mass of bisphenol A type epoxy resin (Etototo YD-128, manufactured by Toto Kasei Co., Ltd.) in a four-necked glass separable flask equipped with a stirrer, thermometer, condenser, and nitrogen gas introduction device Bisphenol A (142.3 parts by mass) was added, dissolved in cyclohexanone, and stirred while introducing nitrogen gas.

  After adding triphenylphosphine as a catalyst and reacting at 160 ° C. for 5 hours, 3,4,5,6-dibenzo-1,2-oxaphosphan-2-oxide hydroquinone (manufactured by Sanko Co., Ltd., HCA- HQ, phosphorus compound represented by formula (IV), phosphorus content of about 9.5% by mass) (354.0 parts by mass) was added, and the mixture was further reacted for 4 hours, and then diluted with toluene and MEK. The phosphorus-containing phenoxy resin thus obtained had a weight average molecular weight of about 55000 and a phosphorus content of 4.5% by mass.

  The weight average molecular weight was measured by the permeation chromatograph method (GPC) under the following conditions.

Equipment: HLC-8120GPC manufactured by Tosoh Corporation
Column: guredcolomnSuperH-H + SuperHM-H x 2 Eluent: Chloroform 0.6 ml / min
Detector: Differential refractometer (RI)
Temperature: 40 ℃
Molecular weight calculation: Polystyrene conversion
(3-2) Phosphorus-containing phenoxy resin 1
251.7 parts by mass of bisphenol A type epoxy resin (Etototo YD-128, manufactured by Toto Kasei Co., Ltd.) in a four-necked glass separable flask equipped with a stirrer, thermometer, condenser, and nitrogen gas introduction device Bisphenol A (142.3 parts by mass) was added, dissolved in cyclohexanone, and stirred while introducing nitrogen gas.

After adding triphenylphosphine as a catalyst and reacting at 160 ° C. for 1 hour, 3,4,5,6-dibenzo-1,2-oxaphosphan-2-oxide hydroquinone (manufactured by Sanko Co., Ltd., HCA- HQ, phosphorus compound represented by formula (IV), phosphorus content of about 9.5% by mass) (354.0 parts by mass) was added, and the mixture was further reacted for 4 hours, and then diluted with toluene and MEK. The phosphorus-containing phenoxy resin thus obtained had a weight average molecular weight of about 10,000 and a phosphorus content of 4.5% by mass.
(3-3) Phosphorus-containing phenoxy resin 2
251.7 parts by mass of bisphenol A type epoxy resin (Etototo YD-128, manufactured by Toto Kasei Co., Ltd.) in a four-necked glass separable flask equipped with a stirrer, thermometer, condenser, and nitrogen gas introduction device Bisphenol A (142.3 parts by mass) was added, dissolved in cyclohexanone, and stirred while introducing nitrogen gas.

After adding triphenylphosphine as a catalyst and reacting at 160 ° C. for 10 hours, 3,4,5,6-dibenzo-1,2-oxaphosphan-2-oxide hydroquinone (manufactured by Sanko Co., Ltd., HCA- HQ, phosphorus compound represented by formula (IV), phosphorus content of about 9.5% by mass) (354.0 parts by mass) was added, and the mixture was further reacted for 4 hours, and then diluted with toluene and MEK. The phosphorus-containing phenoxy resin thus obtained had a weight average molecular weight of about 110,000 and a phosphorus content of 4.5% by mass.
(3-4) Phenoxy resin YP-55 manufactured by Toto Kasei Co., Ltd. was used.
(4) Phenolic curing agent A novolak type phenol resin (manufactured by Koriei Chemical Industry Co., Ltd., PSM-4357, phenolic hydroxyl group equivalent 105) was used.
(5) Curing accelerator 2-ethyl-4-methylimidazole manufactured by Shikoku Kasei Kogyo Co., Ltd. was used.
(6) Solvent Three kinds of solvents, methyl ethyl ketone, methoxypropanol, and toluene were used.
(Preparation of prepreg)
A glass cloth (manufactured by Nitto Boseki Co., Ltd., WEA1078) having a thickness of about 0.042 mm was used as a fibrous base material used as a material for the prepreg.

After blending the above blending components in the ratio shown in Table 1 and impregnating a glass cloth with an epoxy resin composition for prepreg (varnish) adjusted to a varnish solid content concentration of 40 to 70% by mass using a solvent. The prepreg in a semi-cured B-stage state was prepared by heating and drying for about 3 to 15 minutes in the range of 120 to 190 ° C. with a dryer.
(Preparation of copper-clad laminate)
A copper clad laminate was prepared using the prepreg obtained as described above. A copper-clad laminate with a thickness of about 0.06 mm is obtained by laminating copper foil on both sides of one prepreg and laminating it by heating and pressing under conditions of 140 to 200 ° C. and 0.98 to 4.9 MPa. A plate was made. The heating time was set so that the time for the entire prepreg to be 180 ° C. or higher was at least 60 minutes.
(Production of multilayer printed wiring board)
A printed wiring board was produced using the prepreg produced as described above. First, as shown in FIG. 1 (a), one surface of the prepreg 2 is superimposed on the surface of the inner layer circuit board 1 on which the inner layer circuit has been formed in advance, and the rough surface of the release material 3 is disposed on the other surface of the prepreg 2. Were stacked and laminated.

  Here, the copper-clad laminate produced using said prepreg was used for production of the inner layer circuit board 1. Moreover, as the mold release material 3, electrolytic copper foil (manufactured by Mitsui Metal Mining Co., Ltd., 3EC-VLP, thickness 12 μm) was used. In addition, lamination molding is performed by heating and pressing under conditions of 140 to 200 ° C. and 0.98 to 4.9 MPa, and the heating time is set so that the time when the entire prepreg 2 is 180 ° C. or more is at least 60 minutes or more. went.

  Then, the release material 3 was removed by etching from the state shown in FIG. 1B after the lamination molding to expose the insulating layer 4 as shown in FIG.

  Next, the laminated molded product was subjected to necessary processing such as laser via processing, and then the insulating layer 4 was roughened to form dense irregularities on the surface of the insulating layer 4 as shown in FIG. . This roughening treatment was performed according to the following procedure. First, the laminated molded product of FIG. 1C was immersed in a “Circuposit MLB211” solution manufactured by Rohm and Haas for 5 minutes at 70 ° C. Next, it was immersed in “Circuposit MLB213” solution at 80 ° C. for 10 minutes. Finally, it was immersed in the “Circuposit MLB216-2” solution at 40 ° C. for 5 minutes.

  Then, as shown in FIG.1 (e), the plating 5 was formed in the surface of the roughened insulating layer 4 through the process of an electroless copper plating process and an electrolytic copper plating process. Finally, after baking with a dryer at 180 ° C. for 60 minutes, the outer layer circuit 6 was formed, and a four-layer multilayer printed wiring board as shown in FIG. Here, the thickness of the plated copper in the plating 5 was 20 ± 2 μm.

The following physical properties of the multilayer printed wiring board produced above were evaluated.
[Plating peel strength]
About the multilayer printed wiring board of Examples 1-5 and Comparative Examples 1-5, the peel strength of the outer layer circuit (plated copper width 10mm) was measured at 25 degreeC by the 90 degree | times peel test method according to JIS-C6481.
[Flame retardance]
A four-layer printed wiring board without an inner layer circuit is manufactured in accordance with the above multilayer printed wiring board, and the outer layer circuit is removed by etching, and this is cut into a length of 125 mm and a width of 13 mm. Under Testers of Tester for Flammability of Underwriters Laboratories The combustion behavior was tested in accordance with “of Plasticmaterials-UL94”.
[Solder heat resistance]
A four-layer printed wiring board without an inner layer circuit was prepared according to the above multilayer printed wiring board, and a sample was prepared by cutting the printed wiring board into 25 mm squares. This sample was immersed in a solder bath at 260 ° C. for 10 seconds, and a sample having no swelling was evaluated as “◯” and a sample having swelling was evaluated as “x”.

  The results of physical property evaluation are shown in Table 1.

  From Table 1, an epoxy resin (A) containing two or more phenyl skeletons in one molecule, a phosphorus-containing epoxy resin (B), a phosphorus-containing phenoxy resin (C) having a weight average molecular weight of 30,000 to 80,000, and a phenolic curing agent ( In Examples 1 to 3 in which D) is blended and the phosphorus content is in the range of 0.5 to 1.5 mass% with respect to the solid content of the epoxy resin composition for prepreg, the plating peel strength is high, and V It had a flame resistance of −0 and was excellent in solder heat resistance.

  In Example 4, as an epoxy resin (A) containing two or more phenyl skeletons in one molecule, the decomposition / solubility of the cured product in a roughening solution is a phosphorus-containing epoxy as in the naphthalene type epoxy resin of Example 1. A biphenyl type epoxy resin lower than that of the resin (B) was used, but the plating peel strength was high as in Examples 1 to 3, the flame retardancy was V-0, and the solder heat resistance was also excellent. It was.

  In Example 5, as an epoxy resin (A) containing two or more phenyl skeletons in one molecule, the decomposition / solubility of the cured product in the roughening solution is the same as or higher than that of the phosphorus-containing epoxy resin (B). A certain phenol novolac type epoxy resin was used. In this case, it has V-0 flame retardancy and excellent solder heat resistance, while naphthalene type epoxy resin or biphenyl as epoxy resin (A) containing two or more phenyl skeletons in one molecule. Compared with the case of Examples 1-4 using a type epoxy resin, the plating peel strength decreased.

  On the other hand, in Comparative Example 1, since the phosphorus content was high, the solder heat resistance was lowered.

  In Comparative Example 2, since the phosphorus content was low, V-0 flame retardancy was not obtained.

  In Comparative Example 3, since a phenoxy resin containing no phosphorus was used, the plating peel strength was reduced, V-0 flame retardancy was not obtained, and solder heat resistance was also reduced.

  In Comparative Example 4, since the weight average molecular weight of the phosphorus-containing phenoxy resin was small, the plating peel strength and the solder heat resistance were reduced.

  In Comparative Example 5, since the weight average molecular weight of the phosphorus-containing phenoxy resin was large, the plating peel strength and the solder heat resistance were lowered.

It is the figure which showed an example of the method of producing a printed wiring board using the prepreg of this invention in process order.

Explanation of symbols

1 inner layer circuit board 2 prepreg 4 insulating layer 5 plating 6 outer layer circuit

Claims (5)

An epoxy resin (A) containing two or more phenyl skeletons in one molecule and the following formula (I) or formula (II):

(In the formula, each R independently represents a hydrocarbon group having 1 to 6 carbon atoms, and n represents an integer of 0 to 4). A reaction product of at least one selected from phosphorus compounds represented by A phosphorus-containing epoxy resin (B) obtained by reacting an organic phosphorus compound and an epoxy resin, a phosphorus-containing phenoxy resin (C) having a weight average molecular weight of 30,000 to 80,000, and a phenol-based curing agent (D) An epoxy resin composition for prepreg, which is contained and has a phosphorus content of 0.5 to 1.5% by mass relative to the solid content of the epoxy resin composition for prepreg.   The epoxy resin (A) containing two or more phenyl skeletons in one molecule is a cured product of a phosphorus-containing epoxy resin (B) with respect to a roughening solution in which the cured product contains one or both of an oxidizing agent and an acid. The epoxy resin composition for prepreg according to claim 1, wherein the epoxy resin composition is less decomposed or dissolved than a cured product of the phosphorus-containing phenoxy resin (C). The phosphorus-containing phenoxy resin (C) includes bisphenol A, an epoxy resin, and the following formula (III) or formula (IV):

The epoxy resin composition for prepreg according to claim 1, wherein the epoxy resin composition is obtained by reacting with a phosphorus compound represented by the formula:   A prepreg obtained by impregnating a base material with the epoxy resin composition for prepreg according to any one of claims 1 to 3 and drying it.   An insulating layer is formed by prepreg by laminating the prepreg according to claim 4 on an inner circuit board on which a circuit has been formed in advance, and the surface of the insulating layer is a roughening solution containing one or both of an oxidizing agent and an acid. A multilayer printed wiring board, wherein a conductor layer is formed by plating on the roughened surface after roughening and an outer layer circuit is formed by the conductor layer.

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