JP2005132925A - Epoxy resin composition and prepreg, metal-foil-clad laminate, and metal-foil-fitted resin sheet using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an epoxy resin composition which has a permittivity and a dielectric loss tangent smaller than those of a conventional epoxy resin composition without detriment to its varnish properties and adhesiveness and to provide a prepreg, a printed wiring board, and a metal-foil-fitted resin sheet each using the epoxy resin composition and each having excellent high-frequency characteristics. <P>SOLUTION: The epoxy resin composition is an epoxy resin composition comprising (A) a polyphenylene ether, (B) a halogen-containing epoxy resin, (C) a curing agent, (D) a cure accelerator, and (E) a phosphoric acid ester, wherein the epoxy resin composition contains at least one specified phosphoric acid ester, the total amount of the specified phosphoric acid is 10 to 100 pts.wt. per 100 pts.wt. total amount of resins represented by (A) to (D). <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention is useful as an insulating material such as a printed wiring board, an epoxy resin composition, a prepreg using the epoxy resin composition, a laminated board using the prepreg, and a printed wiring board using the laminated board, Moreover, it is related with the resin sheet with metal foil using this epoxy resin composition.

  Thermosetting resins typified by epoxy resins are widely used as printed wiring board materials and semiconductor sealing materials because of their excellent adhesion, electrical insulation, chemical resistance, and the like. When used in these applications, a compound containing a halogen element typified by bromine is generally blended for imparting fire resistance to fire.

  In recent years, electronic devices have made great progress with the high integration of semiconductor devices to be mounted and the elaboration of packages, the high density wiring of printed wiring boards, and the improvement of bonding and mounting technologies, especially mobile objects. Progress has been remarkable in electronic devices that use high-frequency bands such as communications.

  The printed wiring boards that make up this type of electronic equipment are being made multilayered and miniaturized at the same time. However, to increase the signal transmission speed required for high-speed information processing, the dielectric constant of the material must be reduced. In order to reduce the loss during transmission, it is necessary to use a material having a low dielectric loss tangent.

  An epoxy resin composition (epoxy resin thermosetting resin composition) containing an epoxy resin, its curing agent, and polyphenylene ether as a resin system having excellent high-frequency characteristics, or a substrate such as a glass cloth. The prepreg united with is known since 1970. This resin composition exhibits excellent high frequency characteristics when cured, and particularly exhibits excellent high frequency characteristics in the X band (10 GHz) region used in the satellite communication wave region.

  However, the dielectric constant of the epoxy resin-based laminate using PPE currently on the market is approximately 4.0 to 4.5 and the dielectric loss tangent is approximately 0.010. With the progress of realization, there is a possibility that problems such as malfunction of the circuit and circuit failure will occur with the current values of dielectric constant and dielectric loss tangent, and materials with smaller dielectric constant and dielectric loss tangent are required.

Conventionally, in order to reduce the dielectric constant and dielectric loss tangent of the glass epoxy laminate, a method using polytetrafluoroethylene as a filler (filler) (Japanese Patent Laid-Open No. 2000-212362) or a hollow body such as a hollow plastic particle is used. A technique to be used (Japanese Patent Laid-Open No. 2003-147166) is disclosed. In addition to the hollow plastic particles described in the above publication, organic hollow fillers include those obtained by applying an inorganic coating to an organic hollow body. However, these fillers are generally insoluble in epoxy resins. As the filling amount increases, the viscosity of the varnish of the epoxy resin composition to which the solvent is added is remarkably increased, the dispersibility of the filler is deteriorated, or the impregnation property when impregnating the base material is deteriorated. There is also a problem, and there also arises a problem that the adhesive strength is lowered when the epoxy resin composition is cured by heating to produce a laminate.
JP 2000-212362 A JP 2003-147166 A

  Therefore, an object of the present invention is to make the dielectric constant and dielectric loss tangent of the conventional epoxy resin composition smaller while maintaining the varnish characteristics and adhesiveness, and the high frequency characteristics using this epoxy resin composition. It is to provide a prepreg, a printed wiring board, and a resin sheet with metal foil which are excellent in the above.

式中、Ｒ１は水酸基又は炭素数１〜４の炭化水素基であり、Ｒ１は同じ基でも異なる 基でもよく、又、ｍは０〜３の整数である。

式中、Ｒ２は水酸素基又は炭素数１〜４の炭化水素基であり、Ｒ２は同じ基でも異な る基でもよい。

Ｒ４及びＲ５は、０〜５までの数の水酸基、又は０〜５までの数の炭素数１〜４の炭 化水素基であり、Ｒ４及びＲ５は同じ基でも異なる基でもよい。
In order to achieve the above object, the epoxy resin composition of the present invention comprises (A) polyphenylene ether, (B) halogen-containing epoxy resin, (C) curing agent, (D) curing accelerator, and (E) phosphoric acid. An epoxy resin composition comprising an ester, wherein the epoxy resin composition includes at least one phosphate ester represented by the chemical formula 1, 2, or 3, and the total addition amount of the phosphate ester is (A ) To (D) is required to be 10 to 100 parts by weight with respect to 100 parts by weight of the total resin.

In the formula, R1 is a hydroxyl group or a hydrocarbon group having 1 to 4 carbon atoms, R1 may be the same group or a different group, and m is an integer of 0 to 3.

In the formula, R2 is a water oxygen group or a hydrocarbon group having 1 to 4 carbon atoms, and R2 may be the same group or different groups.

R4 and R5 are 0 to 5 hydroxyl groups or 0 to 5 hydrocarbon groups having 1 to 4 carbon atoms, and R4 and R5 may be the same group or different groups.

  In order to achieve the above object, the prepreg of the present invention is preferably formed by impregnating the above-mentioned epoxy resin composition into a substrate, heating and drying, and semi-curing.

  In order to achieve the above object, the laminate of the present invention is preferably formed by heating and pressurizing a laminate obtained by laminating a predetermined number of the prepregs and further laminating metal foils.

  In order to achieve the above object, the printed wiring board of the present invention is preferably formed by forming a conductor pattern on the metal foil of the laminate.

  In order to achieve the above object, the resin sheet with metal foil of the present invention is preferably obtained by coating the epoxy resin composition on the metal foil, heating and drying, and semi-curing.

  The epoxy resin composition of the present invention is a resin composition comprising (A) polyphenylene ether, (B) halogen-containing epoxy resin, (C) curing agent, (D) curing accelerator, and (E) phosphate ester. The epoxy resin composition contains at least one phosphate ester represented by the chemical formula 1, 2 or 3, and the total amount of the phosphate ester is represented by the above (A) to (D). It is characterized in that it is 10 to 100 parts by weight with respect to 100 parts by weight of the total resin, and the dielectric constant and dielectric loss tangent of the epoxy resin composition can be further reduced while maintaining the varnish characteristics and adhesiveness, By using this epoxy resin composition, it becomes possible to provide a prepreg, a printed wiring board, and a resin sheet with metal foil that are excellent in high-frequency characteristics.

  The prepreg of the present invention is obtained by impregnating the above-mentioned epoxy resin composition into a base material, heating and drying and semi-curing, and the laminate of the present invention is obtained by laminating a predetermined number of the prepreg and metal foil, The printed wiring board of the present invention is preferably formed by forming a conductor pattern on the metal foil of the laminate, has a low dielectric constant and dielectric loss tangent, is excellent in high-frequency characteristics, and particularly for mobile communication. In an electronic apparatus using such a high frequency band, it is possible to provide a very useful prepreg and printed wiring board.

  Further, the resin sheet with metal foil of the present invention is preferably formed by coating the above epoxy resin composition on the metal foil, heating and drying, and semi-curing, whereby the dielectric constant and dielectric loss tangent are small. A multilayer printed board having excellent high frequency characteristics can be easily manufactured.

  As polyphenylene ether contained in the epoxy resin composition of the present invention, for example, poly (2,6-dimethyl-1,4-phenylene oxide) can be used. Further, a modified polyphenylene ether obtained by reacting a polymer polyphenylene ether having a number average molecular weight of 10,000 to 30,000 with a phenolic compound in the presence of a radical initiator may be used. The number average molecular weight of the modified polyphenylene ether produced at this time is preferably 1000 to 3000. The blending ratio of the solid content of the modified phenol product, the epoxy resin and the curing agent is preferably in the range of 5:95 to 50:50. If the blending amount of the modified phenol product is larger than the above range, the solvent resistance of the laminate formed using this epoxy resin composition may be lowered. On the other hand, if the blending amount of the modified phenol product is less than the above range, the high frequency characteristics such as dielectric constant and dielectric loss tangent of the laminate may be lowered.

  The halogen-containing epoxy resin contained in the epoxy resin composition of the present invention is not particularly limited as long as it has two or more epoxy groups and one or more halogens in one molecule. For example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, biphenyl type epoxy resin, alicyclic epoxy resin, diglycidyl ether compound of polyfunctional phenol, glycidyl polycondensate of phenols and formaldehyde Examples thereof include epoxy resins obtained by halogenating phenolic novolac type epoxy resins, cresol novolac type epoxy resins, bisphenol A novolac type epoxy resins, and the like that are etherified products. They may be used alone or in combination of two or more. A halogenated epoxy resin is an essential component for flame retardancy, but it is also possible to use an epoxy resin containing no halogen.

  Examples of the curing agent contained in the epoxy resin composition of the present invention include amide-based curing agents such as dicyandiamide and aliphatic polyamide, and amine-based curing agents such as diaminodiphenylmethane, metaphenylenediamine, ammonia, triethylamine, and diethylamine. And phenolic curing agents such as bisphenol A, bisphenol F, phenol novolac resin, and cresol novolac resin, and acid anhydrides. They may be used alone or in combination of two or more.

  In the epoxy resin composition of the present invention, the compounding amount of the curing agent is preferably in the range of 0.03 to 0.4 equivalent, more preferably 0.05 to 0.2, relative to 1 equivalent of the epoxy resin. Equivalent range. When the blending amount of the curing agent is less than 0.03 equivalent, the epoxy resin composition is insufficiently cured and the reliability of the laminated board is lowered, the rigidity at the time of curing molding is lowered, and workability is adversely affected. There is a risk. In the case of 0.4 equivalent or more, the handleability may be deteriorated such that the pot life is shortened and the molding width is narrowed.

  The epoxy resin composition of the present invention requires the addition of a curing accelerator in order to accelerate the curing reaction. Examples of the curing accelerator that can be added include imidazoles such as 2-methylimidazole, 2-ethyl-4methylimidazole, 2-phenylimidazole, 1,8-diaza-bicyclo [5.4.0] undecene. -7, tertiary amines such as triethylenediamine and benzyldimethylamine, organic phosphines such as tributylphosphine and triphenylphosphine, and tetraphenylboron salts such as tetraphenylphosphonium tetraphenylborate and triphenylphosphonium tetraphenylborate May be used alone or in combination of two or more.

  It is preferable that the addition amount of a hardening accelerator is 0.2-1.0 weight part with respect to 100 weight part of resin total amount represented by said (A) thru | or (D). If it is less than 0.2 parts by weight, the gelation time is delayed, resulting in a decrease in workability due to a reduction in rigidity at the time of curing. Conversely, if it exceeds 1.0 parts by weight, curing proceeds during molding, resulting in uneven thickness, etc. It tends to occur. Moreover, when using together 2 or more types of hardening accelerators, it is preferable that the sum total is in the said range.

  The phosphate ester used in the present invention has a structure represented by the chemical formula 1, 2, or 3. Since the movement of the phosphate ester is suppressed by the aromatic ring or phenanthrene ring having an alkyl group, the dielectric constant and dielectric loss tangent are lowered. Since these are compatible with the epoxy resin, a uniform epoxy resin composition is obtained. Further, it can be chemically bonded to an epoxy group by an aromatic ring having a hydroxyl group or a phenanthrene ring.

  The addition amount of the phosphate ester is 10 to 100 parts by weight with respect to 100 parts by weight of the total resin of (A) polyphenylene ether, (B) halogen-containing epoxy resin, (C) curing agent, and (D) curing accelerator. It is necessary to be, preferably 20 to 80 parts by weight. If the amount is less than 10 parts by weight, the effect of reducing the dielectric constant and dielectric loss tangent of the cured resin is not sufficient. The heat resistance of the object decreases.

  The epoxy resin composition of the present invention may contain an inorganic filler such as silica as necessary. Examples of the inorganic filler that can be contained include silica, aluminum hydroxide, magnesium hydroxide, E glass powder, alumina, magnesium oxide, titanium dioxide, potassium titanate, calcium silicate, calcium carbonate, clay, and talc. May be used alone or in combination of two or more.

  The content of the inorganic filler is preferably less than 200 parts by weight with respect to 100 parts by weight of the total resin represented by the above (A) to (D). If it is this range, the drilling workability and rigidity of the laminated board obtained by shaping | molding will improve. When the content of the inorganic filler is 200 parts by weight or more, the impregnation property and the handleability deteriorate due to the increase in viscosity, which is not preferable.

  A solvent etc. can be used for the epoxy resin composition of this invention as needed. Examples of the solvent that can be used include organic solvents such as dimethylformamide, toluene, xylene, benzene, ketones, alcohols, and cell solves.

  The epoxy resin composition of the present invention is produced by uniformly mixing the above components with, for example, a mixer. There is no restriction | limiting in particular in the mixing | blending order of a component.

  A solvent such as toluene is added to the epoxy resin composition of the present invention thus obtained to prepare an epoxy resin varnish, impregnated into a substrate made of glass cloth or the like, and dried to produce the prepreg of the present invention. . The method for impregnating and drying the epoxy resin composition on the substrate is not particularly limited. For example, after impregnating the substrate in the epoxy resin composition by impregnation, the temperature is about 120 ° C to 180 ° C. A method of semi-curing the epoxy resin by removing the solvent by heating at a temperature can be employed. The resin impregnation amount of the prepreg produced by impregnating and drying the substrate is not particularly limited, but is preferably 30 to 70% by weight.

  As a base material impregnated with the epoxy resin composition, aramid cloth, polyester cloth, glass nonwoven fabric, paper and the like can be used in addition to the glass cloth described above.

  A predetermined number of the obtained prepregs are stacked, and metal foils are further laminated to form a pressed body, and the pressed body is heated and pressurized to produce the laminate of the present invention. As the metal foil, copper foil, aluminum foil or the like is used. The thickness of the metal foil is generally 3 μm to 105 μm, and particularly preferably 12 μm to 35 μm. The laminate of the present invention thus obtained is a laminate excellent in high frequency characteristics such as dielectric characteristics and adhesiveness.

  Further, the obtained epoxy resin composition was applied to the surface of a metal foil of 3 μm to 105 μm, and heated and dried at a temperature of about 120 ° C. to 180 ° C. in a dryer, thereby providing a metal foil on the surface. The resin sheet with a metal foil of the present invention in a semi-cured state can be produced.

(Example 1)
30 parts by weight of polymer polyphenylene ether (manufactured by GE Plastics Co., Ltd., product number “Noryl 640-111”) and 1.2 parts by weight of bisphenol A were mixed by heating and melting, and then 1.5 parts by weight of radicals. A modified phenol product was prepared by blending a polymerization initiator (manufactured by NOF Corporation, benzoyl peroxide) and reacting the polymer polyphenylene ether and bisphenol A. As an epoxy resin, 48 parts by weight of brominated bisphenol A type epoxy resin (manufactured by Toto Kasei Co., Ltd., product number “YDB400”) and 18 parts by weight of phenol novolac type epoxy resin (manufactured by Dainippon Ink Co., Ltd., product number “N775”). )). 1 part by weight of diaminodiphenylmethane (manufactured by Japan Epoxy Resin Co., Ltd., product name “Etacure”) is used as a resin curing agent, and 0.3 part by weight of 2-ethyl-4methylimidazole (manufactured by Shikoku Kasei Kogyo Co., Ltd.) as a curing accelerator. ) And 40 parts by weight of a phosphoric acid ester (manufactured by Daihachi Chemical Co., Ltd., product number “PX200”, the structure corresponds to the chemical formula 2) is added to these mixtures to obtain the epoxy resin composition of the present invention. It was. Toluene serving as a solvent was added to the epoxy resin composition to prepare an epoxy resin varnish so that the solid content was 55% by weight. This was impregnated into E glass cloth having a thickness of 0.1 mm and dried at 160 ° C. for 5 minutes to obtain a prepreg having a resin content of 45% by weight. 8 manufactured prepregs are stacked, and 18 μm thick copper foil is placed on both sides to form a pressure-receiving body, and heated and pressed for 120 minutes under conditions of a temperature of 200 ° C. and a pressure of 2 MPa (megapascal). A copper-clad laminate with a foil attached was obtained.

(Example 2)
An epoxy resin varnish was prepared in the same manner as in Example 1 except that the addition amount of the phosphate ester “PX200” was 20 parts by weight, and a prepreg and a copper-clad laminate were obtained.

(Example 3)
An epoxy resin varnish was prepared in the same manner as in Example 1 except that the amount of the phosphate ester “PX200” was changed to 80 parts by weight, and a prepreg and a copper-clad laminate were obtained.

Example 4
An epoxy resin varnish was prepared in the same manner as in Example 1 except that 40 parts by weight of phosphoric acid ester “HCA-HQ” (manufactured by Sanko Co., Ltd., structure corresponds to the above chemical formula 3) was used instead of phosphoric acid ester “PX200”. To obtain a prepreg and a copper-clad laminate.

(Example 5)
An epoxy resin varnish was prepared in the same manner as in Example 1 except that 40 parts by weight of a phosphoric acid ester “TXP” (manufactured by Daihachi Chemical Co., Ltd., the structure corresponds to the above chemical formula 1) was used instead of the phosphoric acid ester PX200. Thus, a prepreg and a copper-clad laminate were obtained.

(Comparative Example 1)
Except not adding phosphate ester "PX200", it carried out like Example 1 and prepared the epoxy resin varnish, and obtained the prepreg and the copper clad laminated board.

(Comparative Example 2)
An epoxy resin varnish was prepared in the same manner as in Example 1 except that the addition amount of the phosphate ester “PX200” was changed to 5 parts by weight to obtain a prepreg and a copper-clad laminate.

(Comparative Example 3)
An epoxy resin varnish was prepared in the same manner as in Example 1 except that the addition amount of the phosphate ester “PX200” was changed to 120 parts by weight to obtain a prepreg and a copper-clad laminate.

(Comparative Example 4)
An epoxy resin varnish was prepared in the same manner as in Example 1 except that 40 parts by weight of polytetrafluoroethylene powder was used in place of the phosphoric ester “PX200” to obtain a prepreg and a copper-clad laminate.

(Comparative Example 5)
An epoxy resin varnish was prepared in the same manner as in Example 1 except that 40 parts by weight of an organic hollow filler (Matsumoto Microsphere-MFL-80GTA) was used instead of the phosphoric ester “PX200”, and a prepreg and a copper-clad laminate were prepared. Got.

[Evaluation of initial viscosity and storage stability]
The initial viscosity and preservability of the epoxy resin varnishes obtained in Examples 1 to 5 and Comparative Examples 1 to 5 were evaluated. The initial viscosity was measured at 25 ° C. using a B-type viscometer, and a case where it was 500 cps (centipoise) or less was evaluated as “good”, and a case where it exceeded 500 cps was evaluated as “bad”. In addition, the storage stability was measured at 25 ° C. for 24 hours, and the viscosity was measured in the same manner as the initial viscosity. When the viscosity was 500 cps or less, “good” was given, and when it exceeded 500 cps, it was judged “bad”. The results are shown in Table 1.

  As shown in Table 1, the evaluation results of the initial viscosity and storage stability were such that the epoxy resin compositions obtained in Examples 1 to 5 and Comparative Examples 1 to 3 had a low initial viscosity and were not stored with a precipitation phenomenon. In Comparative Example 4 using a polytetrafluoroethylene powder and Comparative Example 5 using an organic hollow filler, the initial viscosity was greatly increased, and precipitation of the additive was observed after storage for 24 hours. It was confirmed that the initial viscosity and the storage stability were inferior.

[Evaluation of prepreg]
The appearance, handleability, and impregnation properties of the prepregs obtained in Examples 1 to 5 and Comparative Examples 1 to 5 were evaluated. Appearance was evaluated by visually observing the presence or absence of appearance defects such as streaks and resin reservoirs, and “○” when there was none and “X” when there was. For the evaluation of handleability, the prepreg was bent 180 degrees, and the presence / absence of peeling of the resin was visually observed. In the evaluation of impregnation property, the cut surface was observed with a scanning electron microscope at a magnification of 1000 times, and “◯” was given when there were no bubbles inside, and “X” was given. The results are shown in Table 1.

  The evaluation results of the prepreg are as shown in Table 1, and the prepregs obtained in Examples 1 to 5 and Comparative Examples 1 to 3 have an appearance, a handleability, and an impregnating property as compared with Comparative Examples 4 and 5. Was confirmed to be excellent. In the prepregs of Comparative Examples 4 and 5, appearance defects such as a resin reservoir were observed, the resin was peeled when bent at 180 °, and in the impregnation evaluation, bubbles showing impregnation defects were found on the cut surface.

[Evaluation of laminated sheet]
The dielectric constant, dielectric loss tangent, copper foil peel strength, and glass transition temperature of the laminates obtained in Examples 1 to 5 and Comparative Examples 1 to 5 were measured. The dielectric constant and dielectric loss tangent were measured according to JIS-6482 No. Measured according to 5.12. The peel strength of the copper foil is the peel strength between the copper foil and the insulating layer in the outermost layer portion of the multilayer board. Measured according to 5.7. Regarding the glass transition temperature, the inner layer material subjected to the whole surface etching was subjected to JIS-6481 No. It measured based on 5.17.5. The results are shown in Table 1.

  As shown in Table 1, the laminated plate obtained in Examples 1 to 5 and Comparative Examples 3 to 5 has a dielectric constant and dielectric constant as compared with Comparative Example 1 and Comparative Example 2, as shown in Table 1. It was confirmed that the tangent was reduced. When Examples 1, 4, and 5 were compared, it was confirmed that the dielectric constant and the dielectric loss tangent showed almost the same value regardless of which phosphate ester represented by the chemical formula 1, 2 or 3 was used. When Examples 1 to 3 were compared, it was confirmed that the dielectric constant and dielectric loss tangent became smaller as the amount of phosphate ester “PX200” added increased. Furthermore, with respect to the dielectric loss tangent, when the examples 1 to 3 and the comparative examples 2 and 3 are combined with respect to the addition amount of the phosphate ester “PX200”, the addition amount is insufficient in the comparative example 2, and the effect is not recognized. In Example 3, it can be seen that the effect is saturated. In Comparative Example 3, the amount of phosphate ester “PX200” added was excessive, so that the glass transition temperature was lowered and the heat resistance was lowered. Comparative Example 4 using polytetrafluoroethylene powder and Comparative Example 5 using organic hollow filler all showed good high-frequency characteristics, but compared with Examples 1-5 and Comparative Examples 1-3. It was confirmed that the adhesive strength between the copper foil and the glass cloth was inferior.

  The epoxy resin composition of the present invention is a resin composition comprising (A) polyphenylene ether, (B) halogen-containing epoxy resin, (C) curing agent, (D) curing accelerator, and (E) phosphate ester. The epoxy resin composition contains at least one phosphate ester represented by the chemical formula 1, 2 or 3, and the total amount of the phosphate ester is represented by the above (A) to (D). It is characterized by being 10 to 100 parts by weight with respect to 100 parts by weight of the total resin, and the dielectric constant and dielectric loss tangent of the epoxy resin composition can be further reduced while maintaining varnish characteristics and adhesiveness. By using an epoxy resin composition, it has become possible to provide a prepreg, a printed wiring board, and a resin sheet with metal foil that are excellent in high-frequency characteristics.

  The prepreg of the present invention is obtained by impregnating the above-mentioned epoxy resin composition into a base material, heating and drying and semi-curing, and the laminate of the present invention is obtained by laminating a predetermined number of the prepreg and metal foil, The printed wiring board of the present invention is preferably formed by forming a conductor pattern on the metal foil of the laminate, has a low dielectric constant and dielectric loss tangent, is excellent in high-frequency characteristics, and particularly for mobile communication. In an electronic apparatus using such a high frequency band, it has become possible to provide a very useful prepreg and printed wiring board.

The resin sheet with a metal foil of the present invention is preferably formed by coating the above epoxy resin composition on a metal foil, heating, drying, and semi-curing, having a small dielectric constant and dielectric loss tangent, and high frequency It has become possible to easily produce a multilayer printed board having excellent characteristics.

Claims (5)

An epoxy resin composition comprising (A) polyphenylene ether, (B) a halogen-containing epoxy resin, (C) a curing agent, (D) a curing accelerator, and (E) a phosphoric ester, wherein the epoxy resin composition is , Including at least one phosphate ester represented by Chemical Formula 1, 2, or 3, wherein the total addition amount of the phosphate ester is 100 parts by weight of the total resin represented by (A) to (D) above. 10 to 100 parts by weight of an epoxy resin composition.

In the formula, R1 is a hydroxyl group or a hydrocarbon group having 1 to 4 carbon atoms, R1 may be the same group or a different group, and m is an integer of 0 to 3.

In the formula, R2 is a hydroxyl group or a hydrocarbon group having 1 to 4 carbon atoms, and R2 may be the same group or different groups.

R4 and R5 are 0 to 5 hydroxyl groups or 0 to 5 hydrocarbon groups having 1 to 4 carbon atoms, and R4 and R5 may be the same group or different groups.   A prepreg obtained by impregnating a base material with the epoxy resin composition according to claim 1 and semi-curing by heating and drying.   A metal foil-clad laminate obtained by laminating a predetermined number of prepregs according to claim 2 and further laminating and arranging metal foils by heating and pressing.   A printed wiring board comprising a conductive pattern formed on the metal foil of the laminate according to claim 3. A resin sheet with a metal foil, wherein the epoxy resin composition according to claim 1 is coated on a metal foil, heated and dried, and semi-cured.