JP2012158645A - Epoxy resin composition for printed wiring board, prepreg, metal-clad laminate, resin sheet, printed wiring board, and semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composition for a printed wiring board which secures, when an insulating layer is formed, a minute roughened shape on the surface of the insulating layer and sufficient plating peel strength, and to provide a resin sheet, a prepreg, a metal-clad laminate, a printed wiring board and a semiconductor device each using the resin composition for a printed wiring board.SOLUTION: The resin composition for a printed wiring board includes, as essential components, (A) an epoxy resin, (B) a polyvinyl acetal resin, and (C) fine particles having an average particle size of 5-120 nm.

Description

  The present invention relates to an epoxy resin composition for printed wiring boards, a prepreg, a metal-clad laminate, a resin sheet, a printed wiring board, and a semiconductor device.

In recent years, with the demand for higher functionality of electronic devices, etc., high-density integration of electronic components, and further high-density mounting, etc. are progressing. Compared to the prior art, miniaturization, thinning, high density, and multilayering are progressing. Accordingly, there is a need for a printed wiring board that satisfies basic requirements such as workability and can form a high-density and fine conductor pattern.

In order to form a fine wiring circuit, it is necessary to form a fine rough shape on the surface of the insulating layer formed from the resin composition.
However, when a fine roughened shape is formed, there is a problem that the adhesion strength (plating peel strength) between the conductor circuit and the insulating layer is lowered.

A resin composition (see, for example, Patent Document 1), a polyimide auxiliary resin, which forms a fine roughened shape and has rubber particles as an adhesive layer on the surface of the insulating layer in order to obtain sufficient plating peel strength. For example, see Patent Document 2.) However, there is no insulating surface layer having a fine roughened shape and sufficient plating peel strength.

JP 2006-159900 A JP 2006-196863 A

The present invention has been accomplished in view of the above circumstances, and when an insulating layer is formed, the printed wiring board has a fine roughened shape on the surface of the insulating layer and sufficient plating peel strength. An epoxy resin composition and a resin sheet, a prepreg, a metal-clad laminate, a printed wiring board, and a semiconductor device using the epoxy resin composition for a printed wiring board are provided.

The above object is achieved by the present invention described in the following [1] to [9].
[1] An epoxy resin composition for printed wiring boards, comprising (A) an epoxy resin, (B) a polyvinyl acetal resin, and (C) fine particles having an average particle diameter of 5 to 120 nm as essential components.
[2] The epoxy resin composition for a printed wiring board according to [1], wherein the (B) polyvinyl acetal resin has 15 to 30 mol% of a hydroxyl group in 1 mol of the (B) polyvinyl acetal resin.
[3] The epoxy resin composition for printed wiring boards according to [1] or [2], wherein the epoxy resin composition for printed wiring boards further contains (D) a cyanate resin.
[4] A prepreg obtained by impregnating a substrate with the epoxy resin composition for printed wiring boards according to any one of [1] to [3].
[5] A metal-clad laminate having a metal foil on at least one side of the prepreg according to [4] or a laminate in which two or more prepregs are laminated.
[6] A resin sheet formed by forming an insulating layer made of the epoxy resin composition for printed wiring boards according to any one of [1] to [3] on a film or a metal foil.
[7] A printed wiring board comprising the prepreg according to [4] or the metal-clad laminate according to [5] as an inner circuit board.
[8] Printed wiring board [9] [7] formed by laminating the prepreg according to [4] and / or the resin sheet according to [6] on the inner layer circuit board on the circuit of the inner layer circuit board, or A semiconductor device comprising a semiconductor element mounted on the printed wiring board according to [8].

The epoxy resin composition for a printed wiring board of the present invention has a fine roughened shape on the surface of the insulating layer and has a sufficient plating peel strength when the insulating layer is formed.

It is the schematic which shows an example of the impregnation coating equipment used for manufacture of the prepreg of this invention. It is the schematic which shows an example of the manufacturing method of the metal-clad laminated board of this invention. It is the schematic which shows another example of the manufacturing method of the metal-clad laminated board of this invention.

Hereinafter, the epoxy resin composition for printed wiring boards, the resin sheet, the prepreg, the metal-clad laminate, the printed wiring board, and the semiconductor device of the present invention will be described.

(Epoxy resin composition for printed wiring boards)
First, the epoxy resin composition for printed wiring boards will be described.
The epoxy resin composition for printed wiring boards of the present invention (hereinafter sometimes simply referred to as “epoxy resin composition”) includes (A) an epoxy resin, (B) a polyvinyl acetal resin, and (C) an average particle size of 5 to 5. A fine particle of 120 nm is an essential component. As a result, a resin composition having a small thermal expansion coefficient and high heat resistance can be obtained, and when the insulating layer is formed, a fine roughened shape can be formed on the surface of the insulating layer, and the conductor High adhesion (plating peel strength) between the circuit and the insulating layer can be obtained.

The (A) epoxy resin is not particularly limited. For example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol E type epoxy resin, bisphenol S type epoxy resin, bisphenol Z type epoxy resin (4,4′- Cyclohexyldiene bisphenol type epoxy resin), bisphenol P type epoxy resin (4,4 ′-(1,4-phenylenediisopridiene) bisphenol type epoxy resin), bisphenol M type epoxy resin (4,4 ′-(1 , 3-phenylenediisopridiene) bisphenol type epoxy resin), novolak type epoxy resins such as phenol novolak type epoxy resin, cresol novolak type epoxy resin, biphenyl type epoxy resin, xylylene type epoxy resin Xy resin, phenol aralkyl type epoxy resin, biphenyl aralkyl type epoxy resin, biphenyl dimethylene type epoxy resin, trisphenol methane novolac type epoxy resin, glycidyl ethers of 1,1,2,2- (tetraphenol) ethane, trifunctional , Or tetrafunctional glycidylamines, arylalkylene type epoxy resins such as tetramethylbiphenyl type epoxy resin, naphthalene skeleton modified epoxy resin, methoxynaphthalene modified cresol novolac type epoxy resin, naphthalene type epoxy resin such as methoxynaphthalenedylene methylene type epoxy resin Resin, anthracene type epoxy resin, phenoxy type epoxy resin, dicyclopentadiene type epoxy resin, norbornene type epoxy resin, adamantane type epoxy resin, fluorene Epoxy resins, flame-retarded epoxy resin or the like halogenated epoxy resins. One of these can be used alone, two or more having different weight average molecular weights can be used in combination, and one or two or more of these prepolymers can be used in combination.
Among these epoxy resins, at least one selected from the group consisting of biphenyl aralkyl type epoxy resins, naphthalene skeleton-modified epoxy resins, and cresol novolac type epoxy resins is preferable. Thereby, heat resistance and a flame retardance improve.

  Although content of the said (A) epoxy resin is not specifically limited, It is preferable to set it as 5 to 50 weight% on the solid content basis of the whole epoxy resin composition. If the content is less than the lower limit, the curability of the epoxy resin may decrease, or the prepreg obtained from the epoxy resin composition or the moisture resistance of the printed wiring board may decrease. Moreover, when the said upper limit is exceeded, the linear thermal expansion coefficient of a prepreg or a printed wiring board may become large, or heat resistance may fall.

The weight average molecular weight of the (A) epoxy resin is not particularly limited, but a weight average molecular weight of 4.0 × 10 ^{2 to} 1.8 × 10 ⁴ is preferable. If the weight average molecular weight is less than the lower limit, the glass transition temperature is lowered, and if it exceeds the upper limit, the fluidity is lowered and the substrate may not be impregnated with the resin composition. By setting the weight average molecular weight within the above range, the impregnation property of the resin composition with respect to the substrate can be excellent.
The weight average molecular weight of the epoxy resin can be measured by gel permeation chromatography (GPC), for example, and can be specified as a weight molecular weight in terms of polystyrene.

The polyvinyl acetal resin (B) can form a uniform roughened shape on the surface of the insulating resin layer in a desmear process for removing a resin residue after laser processing.
Moreover, (B) High plating adhesiveness with a conductor circuit can be acquired by presence of the polar group of polyvinyl acetal resin.
(B) Polyvinyl acetal resin can be synthesized by, for example, reacting polyvinyl alcohol with an aldehyde in the presence of an acid catalyst such as hydrochloric acid or sulfuric acid to acetalize part or all of the hydroxyl groups of polyvinyl alcohol.
The (B) polyvinyl acetal resin is not particularly limited, but (B) the polyvinyl acetal resin preferably contains 15 to 30 mol% of a hydroxyl group. If the hydroxyl group is smaller than the above range, sufficient roughening may not be performed and plating adhesion may be deteriorated. If the hydroxyl group is larger than the above range, plating defects may occur due to depopulation with desmear. Examples of the polyvinyl acetal resin include, for example, S-LEK BL-5, BL-10, BL-S, BM-S, BH-A, BH-S, KS-10, KS-1, KS-3, and KS manufactured by Sekisui Chemical Co., Ltd. -5, Denkabutyral # 3000-1, # 5000-A, # 6000-C manufactured by Denki Kagaku Kogyo Co., Ltd., and the like, but are not limited thereto.

The fine particles (C) having an average particle diameter of 5 to 120 nm can form a finer and finer roughened shape than the conventional fine particles on the surface of the insulating layer due to a synergistic effect with (B) the polyvinyl acetal resin.
In addition, when other fillers are used in combination with the epoxy resin composition for printed wiring boards, a larger amount of inorganic filler can be uniformly impregnated into the glass fiber base material than in the past. The coefficient of thermal expansion of the metal-clad laminate can be reduced.

The (C) fine particles having an average particle diameter of 5 to 120 nm are not particularly limited. For example, talc, calcined talc, calcined clay, uncalcined clay, mica, glass and other silicates, titanium oxide, alumina, silica, molten Oxides such as silica, carbonates such as calcium carbonate, magnesium carbonate and hydrotalcite, hydroxides such as aluminum hydroxide, magnesium hydroxide and calcium hydroxide, sulfates such as barium sulfate, calcium sulfate and calcium sulfite or Sulfites, zinc borate, barium metaborate, aluminum borate, calcium borate, sodium borate and other borates, aluminum nitride, boron nitride, silicon nitride, carbon nitride and other nitrides, strontium titanate, titanium Examples thereof include titanates such as barium acid. One of these can be used alone, or two or more can be used in combination.
Of these, silica, titanium oxide, barium sulfate and the like are preferable because they are relatively spherical and easily available, and lower the linear thermal expansion coefficient of the metal-clad laminate. Silica is more preferable from the viewpoint of dispersibility.

The shape of the fine particles (C) having an average particle diameter of 5 to 120 nm is preferably spherical. Thereby, the impregnation property can be improved. There are no particular limitations on the method of making the particles spherical. For example, in the case of silica, the particles can be made spherical by dry fused silica such as a combustion method or wet sol-gel silica such as a precipitation method or a gel method.

The blending amount of the fine particles (C) having an average particle diameter of 5 to 120 nm is not particularly limited, but is preferably 1 to 30 parts by weight in the epoxy resin composition for a printed wiring board.
If it is the said range, a fine and fine roughening shape can be formed.
Moreover, when other inorganic fillers are included, when the total volume of the other inorganic fillers is 100 parts by volume, it is preferably 1 to 40 parts by volume with respect to 100 parts by volume. Furthermore, 5-25 volume parts is especially preferable. Thereby, it is excellent in the dispersibility of an inorganic filler, the impregnation property to a fiber base material, and low thermal expansion property.

The epoxy resin composition of the present invention preferably further contains a cyanate resin. Thereby, a flame retardance can be improved more.
The cyanate resin is not particularly limited, and can be obtained, for example, by reacting a halogenated cyanide compound with phenols or naphthols, and prepolymerizing by a method such as heating as necessary. Moreover, the commercial item prepared in this way can also be used.

  The cyanate resin is not particularly limited, and examples thereof include 2,2′-bis (4-cyanatophenyl) isopropylidene, 1,1′-bis (4-cyanatophenyl) ethane, and bis (4-cyanato-3). , 5-dimethylphenyl) methane, 1,3-bis (4-cyanatophenyl-1- (1-methylethylidene)) benzene, bis (4-cyanatophenyl) thioether, bis (4-cyanatophenyl) ether 1,1,1-tris (4-cyanatophenyl) ethane, tris (4-cyanatophenyl) phosphite, bis (4-cyanatophenyl) sulfone, 2,2-bis (4-cyanatophenyl) Propane, 1,3-, 1,4-, 1,6-, 1,8-, 2,6- or 2,7-dicyanatonaphthalene, 1,3,6-tricyanatonaphthalene, 4,4- Cyanatobiphenyl, phenol novolac type, cresol novolak type, dicyclopentadiene type polyhydric phenols, cyanate resin obtained by reaction with cyanogen halide, naphthol aralkyl type polyvalent naphthols, and cyanogen halide And cyanate resin obtained by the above reaction. Among these, phenol novolac type cyanate resin is excellent in flame retardancy and low thermal expansion, and 2,2-bis (4-cyanatophenyl) isopropylidene and dicyclopentadiene type cyanate resin are used for controlling the crosslinking density, Excellent moisture resistance reliability. In particular, a phenol novolac type cyanate resin is preferred from the viewpoint of low thermal expansion. Furthermore, other cyanate resins may be used alone or in combination of two or more, and are not particularly limited.

The said cyanate resin may be used independently, can also use together cyanate resin from which a weight average molecular weight differs, or can also use together the said cyanate resin and its prepolymer.
The prepolymer is usually obtained by, for example, trimerizing the cyanate resin by a heat reaction or the like, and is preferably used for adjusting the moldability and fluidity of the epoxy resin composition for printed wiring boards. Is.
The prepolymer is not particularly limited. For example, when a prepolymer having a trimerization rate of 20 to 50% by weight is used, good moldability and fluidity can be expressed.

  The content of the cyanate resin is not particularly limited, but is preferably 5 to 60% by weight, more preferably 10 to 50% by weight, based on the solid content of the entire epoxy resin composition for a printed wiring board. Preferably it is 10 to 40% by weight. When the content is within the above range, the cyanate resin can effectively exhibit heat resistance and flame retardancy. When the content of the cyanate resin is less than the lower limit, the thermal expansibility increases and the heat resistance may decrease. When the upper limit is exceeded, the strength of the prepreg produced using the epoxy resin composition for a printed wiring board May decrease.

Moreover, although the epoxy resin composition for printed wiring boards of this invention is not specifically limited, It is preferable that maleimide resin is included. Thereby, heat resistance can be improved.
The maleimide resin is not particularly limited, but N, N ′-(4,4′-diphenylmethane) bismaleimide, bis (3-ethyl-5-methyl-4-maleimidophenyl) methane, 2,2-bis [ And bismaleimide resins such as 4- (4-maleimidophenoxy) phenyl] propane. Furthermore, other maleimide resins can be used alone or in combination of two or more, and are not particularly limited.

The maleimide resin may be used alone, or may be used in combination with maleimide resins having different weight average molecular weights, or may be used in combination with the maleimide resin and its prepolymer.

  The content of the maleimide resin is not particularly limited, but is preferably 1 to 30% by weight, more preferably 5 to 25% by weight, and still more preferably based on the solid content of the epoxy resin composition for printed wiring boards. Is 5 to 20% by weight.

  Furthermore, the epoxy resin composition of the present invention may contain at least one selected from the group consisting of a polyimide resin, a triazine resin, a phenol resin, and a melamine resin.

  The epoxy resin composition for printed wiring boards of this invention can use a phenol type hardening | curing agent. As the phenolic curing agent, for example, a phenol novolak resin, an alkylphenol novolak resin, a bisphenol A novolak resin, a dicyclopentadiene type phenol resin, a zylock type phenol resin, a terpene modified phenol resin, a polyvinylphenol, or the like can be used alone or Two or more types can be used in combination.

Although content of the said phenol type hardening | curing agent is not specifically limited, (A) Equivalent ratio (phenolic hydroxyl group equivalent / epoxy group equivalent) with an epoxy resin is less than 1.0 and 0.1 or more are preferable. As a result, there remains no unreacted phenolic curing agent, and the moisture absorption heat resistance is improved. Furthermore, when severe moisture absorption heat resistance is required, the range of 0.2 to 0.5 is particularly preferable. In addition, the phenol resin not only acts as a curing agent, but can promote curing of a cyanate group and an epoxy group.

  The epoxy resin composition for printed wiring boards of this invention can add additives other than the said component as needed in the range which does not impair a characteristic. Components other than the above components include, for example, epoxy silane coupling agents, cationic silane coupling agents, aminosilane coupling agents, titanate coupling agents, coupling agents such as silicone oil type coupling agents, imidazoles, and triphenyl. Examples thereof include curing accelerators such as phosphine and quaternary phosphonium salts, surface conditioners such as acrylic polymers, and colorants such as dyes and pigments.

The epoxy resin composition for a printed wiring board of the present invention is used as a varnish after being dissolved in a solvent when preparing a prepreg. The method for preparing the varnish is not particularly limited. For example, the slurry (C) in which fine particles having an average particle diameter of 5 to 120 nm are dispersed in a solvent is prepared, and other epoxy resin compositions for printed wiring boards are prepared in the slurry. Examples thereof include a method of adding components and further dissolving and mixing the solvent. (C) Fine particles having an average particle diameter of 5 to 120 nm tend to aggregate and often form secondary aggregation when blended in the resin composition. Such secondary aggregation can be prevented and dispersibility is improved.

  The solvent is not particularly limited, but a solvent exhibiting good solubility in the epoxy resin composition for a printed wiring board is preferable. For example, cyacetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, tetrahydrofuran, dimethylformamide, dimethyl Examples include acetamide, dimethyl sulfoxide, ethylene glycol, cellosolve, and carbitol. In addition, you may use a poor solvent in the range which does not exert a bad influence.

  The solid content of the epoxy resin composition contained in the varnish is not particularly limited, but is preferably 10 to 70% by weight, and particularly preferably 20 to 55% by weight. Thereby, the impregnation property to the base material of the epoxy resin composition for printed wiring boards can be improved.

(Prepreg)
Next, the prepreg will be described.
The prepreg of the present invention is obtained by impregnating a substrate with the epoxy resin composition for a printed wiring board and drying by heating.

The base material is not particularly limited. For example, glass fiber base materials such as glass woven fabric, glass nonwoven fabric, and glass paper, and woven fabric made of synthetic fibers such as paper, aramid, polyester, aromatic polyester, and fluororesin. And woven fabrics, nonwoven fabrics, mats and the like made of nonwoven fabrics, non-woven fabrics, metal fibers, carbon fibers, mineral fibers and the like. These substrates may be used alone or in combination. Among these, a glass fiber base material is preferable. Thereby, the rigidity and dimensional stability of a prepreg can be improved. As glass which comprises such a glass fiber base material, E glass, C glass, A glass, S glass, D glass, NE glass, T glass, H glass, Q glass etc. are mentioned, for example. Among these, it is preferable that glass is S glass or T glass. Thereby, the thermal expansion coefficient of a glass fiber base material can be made comparatively small. Among these, E glass, D glass, and NE glass are preferable from the viewpoint of drill workability.

The method of impregnating the base material with the epoxy resin composition is not particularly limited. For example, the method of immersing the base material in the varnish of the epoxy resin composition for printed wiring boards, the method of applying with various coaters, and the method of spraying by spraying Etc. Among these, the method of immersing a base material in the varnish of the epoxy resin composition for printed wiring boards is preferable. Thereby, the impregnation property of the epoxy resin composition for printed wiring boards with respect to a base material can be improved. In addition, when a base material is immersed in the varnish of the epoxy resin composition for printed wiring boards, a normal impregnation coating equipment can be used. As shown in FIG. 1, the base material 1 is immersed in the epoxy resin varnish 3 of the impregnation tank 2 to impregnate the base material 1 with the epoxy resin varnish 3. In that case, the base material 1 is immersed in the epoxy resin varnish 3 by the dip roll 4 (three in FIG. 1) with which the impregnation tank 2 is equipped. Next, the base material 1 impregnated with the epoxy resin varnish 3 is pulled up in the vertical direction, and a pair of squeeze rolls or comma rolls (5 in FIG. 1 is a squeeze roll) arranged in parallel in the horizontal direction. Through the interval, the application amount of the epoxy resin varnish 3 to the substrate 1 is adjusted. Thereafter, the base material 1 to which the epoxy resin varnish 3 is applied is heated at a predetermined temperature with a dryer 6 to volatilize the solvent in the applied varnish and to semi-cur the epoxy resin composition to prepare the prepreg 7. To manufacture. Note that the upper roll 8 in FIG. 1 rotates in the same direction as the direction of travel of the prepreg 7 in order to move the prepreg 7 in the direction of travel. Moreover, the conditions which dry the solvent of the said epoxy resin varnish can obtain the semi-hardened prepreg 7 by making it dry at the temperature of 90-180 degreeC for 1 to 10 minutes of time.

(Metal-clad laminate)
Next, the metal-clad laminate will be described.
The metal-clad laminate of the present invention has a metal foil on at least one surface of a resin-impregnated base material layer obtained by impregnating a base material with the epoxy resin composition for printed wiring boards.
The metal-clad laminate of the present invention can be produced, for example, by attaching a metal foil to at least one surface of the prepreg or a laminate obtained by superimposing two or more prepregs.
When one prepreg is used, the metal foil is overlapped on both the upper and lower surfaces or one surface. Two or more prepregs can be laminated. When two or more prepregs are laminated, a metal foil or film is laminated on the outermost upper and lower surfaces or one surface of the laminated prepreg. Next, a metal-clad laminate can be obtained by heat-pressing a laminate of a prepreg and a metal foil.

Although the temperature to heat is not specifically limited, 120-250 degreeC is preferable and especially 150-220 degreeC is preferable. Although the pressure to pressurize is not particularly limited, 0.1 to 5 MPa is preferable, and 0.5 to 3 MPa is particularly preferable. Moreover, you may postcure at the temperature of 150-300 degreeC with a high temperature tank etc. as needed.

  Another method for producing the metal-clad laminate of the present invention is a method for producing a metal-clad laminate using the metal foil with an insulating resin layer shown in FIG. First, a metal foil 10 with an insulating resin layer in which a uniform insulating resin layer 12 is coated on a metal foil 11 with a coater is prepared, and the metal foils 10 and 10 with an insulating resin layer are provided on both sides of a substrate 20 such as glass fiber. A prepreg 41 with a metal foil is obtained by a method of laminating and impregnating with an insulating resin layer inside (FIG. 2 (a)) and heating in a vacuum at 60 to 130 ° C. and a pressure of 0.1 to 5 MPa (FIG. 2). (B)). Next, the metal-clad laminate 51 can be obtained by directly heat-pressing the prepreg 41 with metal foil (FIG. 2C).

Furthermore, as another method for producing the metal-clad laminate of the present invention, a method for producing a metal-clad laminate using the polymer film sheet with an insulating resin layer shown in FIG. First, a polymer film sheet 30 with an insulating resin layer obtained by coating a uniform insulating resin layer 32 on the polymer film sheet 31 with a coater, and the polymer film sheet 30 with an insulating resin layer on both sides of the substrate 2; 30 with an insulating resin layer inside (FIG. 3 (a)), and a prepreg 42 with a polymer film sheet is obtained by laminating and impregnating in a vacuum at 60 to 130 ° C. and under a pressure of 0.1 to 5 MPa. Can be obtained (FIG. 3B). Next, after peeling the polymer film sheet 31 on at least one side of the prepreg 42 with the polymer film sheet (FIG. 2C), the metal foil 11 is arranged on the surface from which the polymer film sheet 31 is peeled (FIG. 3D). )), A metal-clad laminate 52 can be obtained by heating and pressing (FIG. 3E). Furthermore, when peeling a double-sided polymer film sheet, two or more sheets can be laminated | stacked like the above-mentioned prepreg. When two or more prepregs are laminated, a metal-clad laminate can be obtained by placing a metal foil or a polymer film sheet on the outermost upper and lower surfaces or one surface of the laminated prepregs and heating and pressing.
The metal-clad laminate obtained by such a manufacturing method has high thickness accuracy, uniform thickness, and excellent surface smoothness.
In addition, since a metal-clad laminate having a small molding strain can be obtained, a printed wiring board and a semiconductor device manufactured using the metal-clad laminate obtained by the manufacturing method have small warpage and small warpage variation.
Furthermore, a printed wiring board and a semiconductor device can be manufactured with high yield.

Although the temperature is not particularly limited as the conditions for the heat and pressure molding, 120 to 250 ° C is preferable, and 150 to 220 ° C is particularly preferable. Although the pressure to pressurize is not particularly limited, 0.1 to 5 MPa is preferable, and 0.5 to 3 MPa is particularly preferable.
Furthermore, if necessary, post-curing may be performed at a temperature of 150 to 300 ° C. in a high-temperature tank or the like.

Although the metal-clad laminates of FIGS. 2 to 3 are not particularly limited, for example, the metal-clad laminate is produced using an apparatus for producing a metal foil with an insulating resin layer and an apparatus for producing a metal-clad laminate.
In the apparatus for producing the metal foil with an insulating resin layer, the metal foil can be supplied by, for example, using a long sheet product in the form of a roll, and continuously unwinding it. A predetermined amount of the liquid insulating resin is continuously supplied onto the metal foil by an insulating resin supply device. Here, as the liquid insulating resin, a coating solution in which the resin composition of the present invention is dissolved and dispersed in a solvent is used. The coating amount of the insulating resin can be controlled by the clearance between the comma roll and the backup roll of the comma roll. The metal foil coated with a predetermined amount of insulating resin is transported inside a horizontal conveying type hot-air drying device to substantially dry and remove the organic solvent contained in the liquid insulating resin. Thus, a metal foil with an insulating resin layer in which the curing reaction has been advanced halfway can be obtained. Although the metal foil with an insulating resin layer can be wound up as it is, a protective film is laminated on the side on which the insulating resin layer is formed by a laminating roll, and the metal foil with an insulating resin layer laminated with the protective film is wound up. Thus, a metal foil with an insulating resin layer in a roll form is obtained. When manufacturing methods such as FIGS. 2 to 3 are used, since the control of the uniform resin amount and the in-plane thickness accuracy are superior to the manufacturing method impregnated with the varnish shown in FIG. Is small and the yield is improved.

Further, when a metal-clad laminate is obtained by such a production method, it is necessary to consider the impregnation property of the resin composition directly into the fiber substrate, not the varnish dissolved and dispersed in the solvent. Since the inorganic filler (C) uses fine particles having an average particle diameter of 5 to 120 nm, particularly the impregnation property to the fiber base material is improved, the resin composition in the metal-clad laminate is heated and pressed. Since the flow is suppressed and uneven movement of the molten resin is suppressed, streaky unevenness on the surface of the metal-clad laminate can be prevented and the thickness can be made uniform.

(Resin sheet)
Next, the resin sheet of the present invention will be described.
The resin sheet of the present invention is obtained by forming an insulating layer made of the epoxy resin composition for printed wiring boards on a metal foil or a film.
Here, the method for forming the insulating layer made of the epoxy resin composition for a printed wiring board on the metal foil or film is not particularly limited. For example, the resin varnish is prepared by dissolving and dispersing the epoxy resin composition in a solvent or the like. A method of drying the resin varnish after applying the resin varnish to the substrate using various coating devices, and a method of drying the resin varnish after spray coating the substrate with a spray device Etc.

Although the film used for the resin sheet of the present invention is not particularly limited, for example, a polyester resin such as polyethylene terephthalate or polybutylene terephthalate, a thermoplastic resin film having heat resistance such as a fluorine resin, or a polyimide resin may be used. it can.
Although the metal foil used for the resin sheet of the present invention is not particularly limited, for example, copper and / or copper-based alloy, aluminum and / or aluminum-based alloy, iron and / or iron-based alloy, silver and / or silver-based alloy, Metal foils such as gold and gold-based alloys, zinc and zinc-based alloys, nickel and nickel-based alloys, tin and tin-based alloys, and the like can be used. In manufacturing the resin sheet of the present invention, the surface roughness (Rz) of the irregularities on the surface of the metal foil on which the insulating layer is laminated is preferably 2 μm or less. By forming an insulating layer made of the resin composition of the present invention on the surface of a metal foil having a surface roughness (Rz) of 2 μm or less, the surface roughness is small and adhesion (plating peel strength) is excellent. Can be.
The surface roughness (Rz) of the metal was measured at 10 points, and the average value was obtained. The surface roughness was measured based on JISB0601.

(Printed wiring board)
Next, the printed wiring board of the present invention will be described.
The printed wiring board of the present invention uses the above metal-clad laminate as an inner layer circuit board. Moreover, the printed wiring board of this invention uses said prepreg or a resin sheet for an insulating layer on an inner layer circuit. Moreover, the printed wiring board of this invention uses said epoxy resin composition for an insulating layer on an inner layer circuit.

In the present invention, a printed wiring board is a circuit in which a circuit is formed of a conductive material such as a metal foil on an insulating layer, a single-sided printed wiring board (single-layer board), a double-sided printed wiring board (double-layer board), and a multilayer. Any of printed wiring boards (multilayer boards) may be used. A multilayer printed wiring board is a printed wiring board that is laminated in three or more layers by a plated through hole method, a build-up method, or the like, and can be obtained by heating and press-molding an insulating layer on an inner circuit board. .
As the inner layer circuit board, for example, a metal layer of the metal-clad laminate of the present invention in which a predetermined conductor circuit is formed by etching or the like and the conductor circuit portion is blackened can be suitably used.
As the insulating layer, a prepreg of the present invention or a resin sheet made of the epoxy resin composition for printed wiring boards of the present invention can be used. In addition, when using the resin sheet which consists of the said prepreg or the said epoxy resin composition for printed wiring boards as said insulating layer, the said inner layer circuit board does not need to consist of the metal-clad laminated board of this invention.

Hereinafter, as a representative example of the printed wiring board of the present invention, a multilayer printed wiring board in which the metal-clad laminate of the present invention is first used as an inner circuit board and the prepreg of the present invention is used as an insulating layer will be described.
A circuit is formed on one or both sides of the metal-clad laminate to produce an inner layer circuit board. In some cases, through holes can be formed by drilling or laser processing, and electrical connection on both sides can be achieved by plating or the like. The insulating layer is formed by superposing the prepreg on the inner layer circuit board and forming it by heating and pressing. Similarly, a multilayer printed wiring board can be obtained by alternately and repeatedly forming conductive circuit layers and insulating layers formed by etching or the like.

  Specifically, a prepreg is stacked on both sides of the inner layer circuit board, and a copper foil is further stacked on both sides, and heat-press molding is performed using a vacuum press apparatus or the like, and the insulating layer is heated and cured. Although it does not specifically limit as conditions to heat-press-mold here, if an example is given, it can implement in temperature 120-240 degreeC, pressure 0.5-5 MPa, time 30-180 minutes.

In the next step, laser is irradiated to form an opening in the insulating layer, but before that, the copper foil must be peeled off by etching or the like.

  Next, the insulating layer is irradiated with laser to form an opening. As the laser, an excimer laser, a UV laser, a carbon dioxide gas laser, or the like can be used.

  It is preferable to perform a treatment for removing resin residues (smear) after laser irradiation with an oxidizing agent such as permanganate or dichromate, that is, desmear treatment. If the desmear treatment is inadequate and the desmear resistance is not sufficiently secured, even if metal plating is applied to the opening, sufficient conductivity is ensured between the upper metal wiring and the lower metal wiring due to smear. There is a risk of disappearing. Further, the surface of the smooth insulating layer can be simultaneously roughened, and the adhesion of the conductive wiring circuit formed by subsequent metal plating can be improved.

Next, an outer layer circuit is formed. The outer layer circuit is formed by connecting the insulating resin layers by metal plating and forming an outer layer circuit pattern by etching.

  Further, an insulating layer may be stacked and a circuit may be formed in the same manner as described above. However, in a multilayer printed wiring board, a solder resist is formed on the outermost layer after the circuit is formed. The method of forming the solder resist is not particularly limited. For example, a method of laminating (laminating) a dry film type solder resist and forming it by exposure and development, or a method of printing a liquid resist by exposure and development It is done by the method to do. In addition, when using the obtained multilayer printed wiring board for a semiconductor device, the electrode part for a connection is provided in order to mount a semiconductor element. The connection electrode portion can be appropriately coated with a metal film such as gold plating, nickel plating, or solder plating.

One of the typical gold plating methods is a nickel-palladium-gold electroless plating method. In this method, a pretreatment is performed on the connecting electrode portion by an appropriate method such as a cleaner, and then a palladium catalyst is applied. Thereafter, an electroless nickel plating treatment, an electroless palladium plating treatment, and an electroless gold plating treatment are further performed. Are performed sequentially.
The ENEPIG method is a method in which a substitution gold plating process is performed in the electroless gold plating process stage of the nickel-palladium-gold electroless plating process. By providing the electroless palladium plating film between the electroless nickel plating film as the base plating and the electroless gold plating film, the diffusion preventing property and the corrosion resistance of the conductor material in the connection electrode portion are improved. Since it is possible to prevent the diffusion of the underlying nickel plating film, the reliability of the Au-Au joint is improved and the nickel oxidation due to gold can be prevented. improves. In the ENEPIG method, it is usually necessary to perform surface treatment before performing electroless palladium plating to prevent the occurrence of poor conduction in the plating process. If the poor conduction is severe, a short circuit occurs between adjacent terminals. Cause. On the other hand, the printed wiring board of the present invention does not have the above-described conduction failure without performing surface treatment, and can be easily plated.

Next, as a representative example of the printed wiring board of the present invention, a printed wiring board when the resin sheet of the present invention is used as an insulating layer will be described.

The resin sheet of the present invention can be obtained by combining with an inner layer circuit board, vacuum heating and pressing using a vacuum pressurizing laminator apparatus, etc., and then heat curing with a hot air drying apparatus or the like.
Here, the conditions for heat and pressure molding are not particularly limited, but for example, it can be carried out at a temperature of 60 to 160 ° C. and a pressure of 0.2 to 3 MPa. Moreover, although the conditions to heat-harden are not specifically limited, For example, it can implement in temperature 140-240 degreeC and time 30-120 minutes.
Further, as another manufacturing method, the resin sheet of the present invention can be obtained by superimposing the resin sheet on the inner layer circuit board and performing heat-pressure molding using a flat plate press device or the like. Although it does not specifically limit as conditions to heat-press form here, For example, it can implement at the temperature of 140-240 degreeC, and the pressure of 1-4 MPa.
The inner layer circuit board is not particularly limited. For example, a through hole is formed by a drill or the like, and after filling the through hole by plating, a predetermined conductor circuit (inner layer circuit is formed on both surfaces of the metal-clad laminate by etching or the like. ) And roughening treatment such as blackening treatment of the conductor circuit to produce an inner layer circuit board. The metal-clad laminate is preferably the metal-clad laminate of the present invention.
Further, the metal foil or film is peeled and removed from the substrate obtained above, and the surface of the insulating layer is roughened with an oxidizing agent such as permanganate or dichromate, and then new by metal plating. A conductive wiring circuit is formed. The insulating layer formed from the resin composition of the present invention can form a large number of fine irregularities with high uniformity in the roughening treatment step, and the insulating layer surface has high smoothness. A simple wiring circuit can be formed with high accuracy.
Thereafter, the insulating layer is cured by heating. Although the temperature to harden | cure is not specifically limited, For example, it can be made to harden | cure in the range of 100 to 250 degreeC. Preferably it is made to harden | cure at 150 to 200 degreeC.
Next, an opening is provided in the insulating layer by using a carbonic acid laser device, and an outer layer circuit is formed on the surface of the insulating layer by electrolytic copper plating to achieve conduction between the outer layer circuit and the inner layer circuit. The outer layer circuit is provided with a connection electrode portion for mounting a semiconductor element.
Finally, a solder resist is formed on the outermost layer, the connection electrode part is exposed so that a semiconductor element can be mounted by exposure and development, nickel gold plating treatment is performed, and a predetermined size is obtained to obtain a multilayer printed wiring board be able to.

(Semiconductor device)
Next, the semiconductor device of the present invention will be described.
A semiconductor element having solder bumps is mounted on the printed wiring board obtained above, and connection to the printed wiring board is attempted through the solder bump. A liquid sealing resin is filled between the printed wiring board and the semiconductor element to form a semiconductor device. The solder bump is preferably made of an alloy made of tin, lead, silver, copper, bismuth or the like.

  The connection method between the semiconductor element and the printed wiring board is to use a flip chip bonder or the like to align the connection electrode part on the substrate and the solder bump of the semiconductor element, and then to an IR reflow device, a heat plate, etc. The solder bumps are heated to a melting point or higher by using a heating device, and the printed wiring board and the solder bumps are connected by fusion bonding. In order to improve connection reliability, a metal layer having a relatively low melting point, such as solder paste, may be formed in advance on the connection electrode portion on the printed wiring board. Prior to this joining step, the connection reliability can be improved by applying a flux to the surface layer of the connection electrode portion on the solder bump and / or printed wiring board.

  Hereinafter, the contents of the present invention will be described in detail by way of examples. However, the present invention is not limited to the following examples unless it exceeds the gist.

The raw materials used in Examples, Comparative Examples and Reference Examples are as follows.
(1) Epoxy resin A: Naphthalene-modified cresol novolac type epoxy resin (EPICLON HP-5000 manufactured by DIC)
(2) Epoxy resin B: biphenyl aralkyl type novolac epoxy resin (NC-3000 manufactured by Nippon Kayaku Co., Ltd.)
(3) Cyanate resin: Novolak-type cyanate resin (Primaset PT-30 manufactured by Lonza Japan)
(4) Bismaleimide compound: BMI-70 manufactured by Kay Chemical Industries
(5) Phenoxy resin: bisphenol A type and F type phenoxy resin (jER-4275 manufactured by Mitsubishi Chemical Corporation)
(6) Polyvinyl acetal resin (I): KS-10 (hydroxyl group 25 mol%) manufactured by Sekisui Chemical Co., Ltd.
(7) Polyvinyl acetal resin (II): BX-L (hydroxyl group 37 mol%) manufactured by Sekisui Chemical Co., Ltd.
(8) Curing agent: 4,4′-diaminodiphenylmethane (9) Curing catalyst: 1-benzyl-2-phenylimidazole (1B2PZ manufactured by Shikoku Chemicals)
(10) Fine particles having an average particle diameter of 5 to 120 nm: spherical silica (NSS-5N manufactured by Tokuyama Corporation, average particle diameter of 75 nm)
(11) Inorganic filler: Spherical silica (SO25R manufactured by Admatechs, average particle size 0.5 μm)
(12) Inorganic filler: Aluminum hydroxide (HP360 manufactured by Showa Denko KK)
(13) Coupling agent: Epoxysilane coupling agent (KBM403 manufactured by Shin-Etsu Chemical Co., Ltd.)

Example 1
(1) Preparation of resin varnish (1) (A) 35 parts by weight of methoxynaphthalene aralkyl epoxy resin (DIC Corporation, EPICLON HP-5000) as an epoxy resin, (B) polyvinyl acetal resin (manufactured by Sekisui Chemical Co., Ltd., ESREC KS) -10; hydroxyl group 25 mol%) 13 parts by weight, (D) 35 parts by weight of phenol novolac cyanate resin (manufactured by LONZA, Primaset PT-30) as cyanate resin, and imidazole (manufactured by Shikoku Kasei Co., Ltd., Curazole 1B2PZ) 1 A part by weight was stirred for 30 minutes with a dimethylacetamide solvent and dissolved. Furthermore, 1 part by weight of an epoxy silane coupling agent (KBE403, manufactured by Shin-Etsu Chemical Co., Ltd.) as a coupling agent and 15 parts by weight of spherical fused silica (NSS-5N, manufactured by Tokuyama Co., Ltd., average particle size 75 nm) as an inorganic filler (C) And stirred for 10 minutes using a high-speed stirrer to prepare a resin varnish having a solid content of 35%.

(2) Production of resin sheet The varnish was applied to one side of a 36 μm thick PET (polyethylene terephthalate) film using a comma coater so that the thickness after drying would be 40 μm. It dried for 3 minutes with the drying apparatus, and formed the resin sheet.

(3) Preparation of prepreg The varnish was impregnated into a glass woven fabric (thickness 87 μm, Nittobo E glass woven fabric, WEA-116E), dried in a heating furnace at 180 ° C. for 2 minutes, and epoxy resin in the prepreg A prepreg having a composition based on solid content of about 50% by weight was obtained.

(4) Fabrication of metal-clad laminate Four layers of the prepreg are stacked, and 12 μm copper foil (3EC-VLP foil manufactured by Mitsui Kinzoku Mining Co., Ltd.) is stacked on both sides, and heated at a pressure of 3 MPa and a temperature of 220 ° C. for 2 hours. A metal-clad laminate having copper foil on both sides was obtained by pressure forming.

(5) Manufacture of printed wiring board The metal-clad laminate having copper foil on both sides is opened with a drill machine, through holes are formed, and then conduction between the upper and lower copper foils is achieved by electroless plating. Inner layer circuits were formed on both sides by etching the foil.
Next, the chemical | medical solution (Asahi Denka Kogyo Co., Ltd. make, Tech SO-G) which has hydrogen peroxide water and a sulfuric acid as a main component was spray-sprayed to the inner layer circuit, and the unevenness | corrugation formation by a roughening process was performed.
On the front and back of the inner layer circuit board, the insulating layer surface of the resin sheet obtained above is overlapped, and this is vacuum-heated and pressure-molded at a temperature of 100 ° C. and a pressure of 1 MPa using a vacuum-pressure laminator device, After that, heat curing was performed at 170 ° C. for 60 minutes with a hot air drying device to produce a multilayer printed wiring board.
The base material was peeled from the multilayer printed wiring board obtained above, and an opening (blind via hole) having a diameter of 60 μm was formed using a carbonic acid laser device.
Then, in order to remove the resin residue (smear), it is immersed for 10 minutes in a swelling solution (Swelling Dip Securigant P, manufactured by Atotech Japan Co., Ltd.) at 80 ° C., and further a potassium permanganate aqueous solution (Atotech Japan Co., Ltd.) at 80 ° C. After immersion for 20 minutes in the company Concentrate Compact CP), neutralization and roughening treatment were performed.
This was subjected to degreasing, catalyst application, and activation steps, and an electroless copper plating film was formed with a power supply layer of about 1 μm. Chromium vapor deposition in which a 25 μm thick UV photosensitive dry film (AQ-2558, manufactured by Asahi Kasei Co., Ltd.) is pasted on the surface of the power feeding layer with a hot roll laminator, and a pattern with a minimum line width / line spacing of 20/20 μm is drawn. The position was adjusted using a mask (manufactured by Towa Process Co., Ltd.), exposure was performed with an exposure apparatus (UX-1100SM-AJN01 manufactured by Ushio Electric Co., Ltd.), and development was performed with an aqueous sodium carbonate solution to form a plating resist.
Next, electrolytic copper plating (81-HL manufactured by Okuno Pharmaceutical Co., Ltd.) was performed at 3 A / dm 2 for 30 minutes using the power feeding layer as an electrode to form a copper wiring having a thickness of about 25 μm. Here, the plating resist was peeled off using a two-stage peeling machine. Each chemical solution is mainly composed of monoethanolamine solution (R-100 manufactured by Mitsubishi Gas Chemical Co., Ltd.) in the first stage alkaline aqueous solution layer, and potassium permanganate and sodium hydroxide as the main ingredients in the second stage oxidizing resin etchant. An aqueous solution of acidic amine (Mc. Dicer 9279, manufactured by Nihon Mcder Mid Co., Ltd.) was used for neutralization.
Then, the power feeding layer was immersed in an ammonium persulfate aqueous solution (AD-485 manufactured by Meltex Co., Ltd.) to remove the etching, and ensure insulation between the wirings. Next, the insulating layer was finally cured at a temperature of 200 ° C. for 60 minutes, and finally a solder resist (manufactured by Taiyo Ink Co., PSR4000 / AUS308) was formed on the circuit surface to obtain a printed wiring board.

(6) Manufacturing of Semiconductor Device A semiconductor device is a semiconductor device (TEG chip, size 15 mm × 15 mm, thickness 0.8 mm) having solder bumps on the printed wiring board for the semiconductor device, using a flip chip bonder device. Obtained by mounting by thermocompression bonding, and then melt-bonding solder bumps in an IR reflow furnace, filling liquid sealing resin (CRP-4152S, manufactured by Sumitomo Bakelite Co., Ltd.), and curing the liquid sealing resin. . The liquid sealing resin was cured at a temperature of 150 ° C. for 120 minutes.
In addition, the solder bump of the said semiconductor element used what was formed with the eutectic of Sn / Pb composition.

(Examples 2-4, Comparative Examples 1-2)
Resin varnishes, resin sheets, prepregs, metal-clad laminates, printed wiring boards, and semiconductor devices were obtained in the same amounts as in Example 1 with the blending amounts shown in Table 1.

The results obtained using Examples and Comparative Examples are shown in Table 1. The contents of the evaluation items are as shown below.
(1) Thermal expansion coefficient The thermal expansion coefficient was measured using a TMA (thermomechanical analysis) apparatus (TA Instruments, Q400).
The metal foil part of the metal-clad laminate was etched and then cut to prepare a 4 mm × 20 mm test piece.
The measurement was performed by measuring the linear expansion coefficient (CTE) at 50 to 100 ° C. in the second cycle under conditions of a temperature range of 30 to 300 ° C., 10 ° C./min, and a load of 5 g.
Each code is as follows.
◎: Less than 15 ppm / ° C ○: 15 ppm / ° C or more and less than 20 ppm / ° C ×: 20 ppm / ° C or more

-Surface roughness In the production of printed wiring boards of Examples and Comparative Examples, a laminate after removing resin residue (smear) after laser processing was prepared, and the resin surface was subjected to laser microscope (manufactured by KEYENCE, VK-8510). Surface roughness (Ra) was measured under the following conditions: PITCH 0.02 μm, RUNmode color ultra-depth.
Ra was measured at 10 points, and an average value of 10 points was obtained.
Each code is as follows.
A: Ra less than 0.6 μm O: Ra 0.6 μm or more and less than 0.9 μm X: Ra 0.9 μm or more

-Plating peel strength In the printed wiring board manufacture of an Example and a comparative example, in order to form a circuit, after forming plated copper, the peeling strength of the plated copper was measured based on JIS C-6481.
Each code is as follows.
A: Peel strength 0.6 kN / m or more B: Peel strength 0.4 kN / m or more and less than 0.6 kN / m X: Peel strength 0.4 kN / m or less

(4) Thermal shock test The semiconductor device obtained above was processed in Fluorinert for 1000 cycles with -55 ° C for 30 minutes and 125 ° C for 30 minutes as one cycle. confirmed. In addition, each code | symbol is as follows.
◎: When there is no abnormality at 1000 cycles or more ○: When abnormality such as a crack occurs at 500 cycles or more and less than 1000 cycles Δ: When an abnormality such as a crack occurs at 300 cycles or more and less than 500 cycles ×: Less than 300 cycles When an abnormality such as

As can be seen from the evaluation results described in Table 1, in Examples 1 to 3, good results were obtained for each evaluation item.
As for the plating peel strength, all of the examples obtained high values, and all of the examples had a low surface roughness, and thus became a low-roughness and high-adhesion material necessary for the processing of thin wire conductor circuits. ing. Also, a low coefficient of thermal expansion of the material was obtained.
Although the comparative example 1 is an example which does not use a polyvinyl acetal resin, it resulted in a low plating peel.
Comparative Example 2 is an example in which the particle size of silica is large, but the surface roughness after the roughening treatment was increased.

Below, the reference example of the copper foil with resin produced using the resin composition of this invention is shown.

(Reference Example 1)
(1) Production of copper foil with resin

The varnish used in Example 1 was applied to a copper foil (YSNAP-3PF manufactured by Nippon Electrolytic Co., Ltd.) having a thickness of 3 μm and a carrier foil of 18 μm using a comma coater so that the thickness after drying would be 5 μm. This was dried for 3 minutes with a drying device at 160 ° C. to form a copper foil with resin. (2) Production of metal-clad laminate 4 layers of EI-6785TS-F (manufactured by Sumitomo Bakelite Co., Ltd.) having a thickness of 100 μm are stacked as a prepreg, and the copper foil with resin is stacked on both sides thereof at a pressure of 3 MPa and a temperature of 220 ° C. Heat-press molding was performed for 2 hours to obtain a metal-clad laminate having copper foil on both sides.
(3) Production of Printed Wiring Board Using the metal-clad laminate and the resin sheet produced in Example 1, a printed wiring board was produced in the same manner as in Example 1.

(Reference Example 2)
A varnish, a primer-attached copper foil, a resin sheet, a metal-clad laminate, a printed wiring board, and a semiconductor device were prepared in the same manner as in Reference Example 1 except that EI-6785GS (manufactured by Sumitomo Bakelite Co., Ltd.) having a thickness of 100 μm was used as the prepreg.

(Reference Example 3)
(1) Preparation of prepreg (A) Epoxy resin B as an epoxy resin: 11 parts by weight of biphenylaralkyl type novolac epoxy resin (NC-3000 manufactured by Nippon Kayaku Co., Ltd.), bismaleimide compound (BMI-70 manufactured by Kay Kasei Kogyo Co., Ltd.) ) 20 parts by weight, 3.5 parts by weight of 4,4′-diaminodiphenylmethane as a curing agent, and 65 parts by weight of aluminum hydroxide (HP360 manufactured by Showa Denko KK) as an inorganic filler in a mixed solvent of dimethylacetamide and methyl ethyl ketone for 30 minutes Stir and dissolve. Furthermore, 0.5 part by weight of an epoxy silane coupling agent (KBM403 manufactured by Koshi Chemical Industry Co., Ltd.) was added as a coupling agent, and the mixture was stirred for 10 minutes using a high-speed stirring device to prepare a resin varnish having a solid content of 35%.
Next, the obtained resin varnish was obtained in the same manner as in Example 1 to obtain a prepreg.
(2) Production of metal-clad laminate and printed wiring board A metal-clad laminate and a printed wiring board were obtained in the same manner as in Reference Example 1 except that the prepreg obtained above was used.

(Reference Example 4)
Reference Example 1, a metal-clad laminate, and a printed wiring board were prepared except that a copper foil having a thickness of 3 μm (manufactured by Nippon Electrolytic Co., Ltd., YSNAP-3B) was used as the copper foil.

(Reference Example 5)
A metal-clad laminate, a printed wiring board, and a semiconductor device were produced in the same manner as in Reference Example 2 except that a 3 μm thick copper foil (manufactured by Nippon Electrolytic Co., Ltd., YSNAP-3B) was used as the copper foil.

The following evaluation was performed using the metal-clad laminates and printed wiring boards of Reference Examples 1 to 5 obtained above.

(Evaluation 1) Thermal expansion coefficient The thermal expansion coefficient was measured using a TMA (thermomechanical analysis) device (TA Instruments, Q400).
The metal foil part of the metal-clad laminate obtained in Reference Examples 1 to 5 was etched and then cut to prepare a 4 mm × 20 mm test piece.
The measurement was performed by measuring the linear expansion coefficient (CTE) at 50 to 100 ° C. in the second cycle under conditions of a temperature range of 30 to 300 ° C., 10 ° C./min, and a load of 5 g.
Each code is as follows.
A: Less than 7 ppm / ° C. B: 7 ppm / ° C. or more

(Evaluation 2) Heat resistance test The heat resistance test was performed using the printed wiring boards obtained in Reference Examples 1 to 5.
The printed wiring board was subjected to reflow treatment 30 times under the reflow conditions of lead flow in accordance with JEDEC J-STD-020B.
Each code | symbol is as follows.
◎: When there is no abnormality such as bulge after 30 times ○: When there is no abnormality such as bulge after 15 times △: When there is no abnormality such as bulge after 3 times ×: Bulge within 3 times If there is an abnormality

The evaluation results of Reference Examples 1 to 5 are shown in Table 2.

Reference Examples 1 to 3 are examples in which the resin composition of the present invention was used for the resin-coated copper foil resin, and all of the results were excellent in heat resistance. Reference Example 4 and Reference Example 5 are examples in which a copper foil is used instead of a resin-coated copper foil, but the adhesion between the resin of the metal-clad laminate and the inner layer copper foil is reduced, resulting in swelling in the heat resistance test. It was.
Especially when using a metal-clad laminate with a low thermal expansion coefficient compared to copper or solder resist, which is a conductor circuit, as in Reference Example 4, the adhesion is improved by using a copper foil with resin, In addition, since the stress generated during processing is relaxed, it is assumed that a large heat resistance improvement effect was obtained.

DESCRIPTION OF SYMBOLS 1 ... Base material 2 ... Impregnation tank 3 ... Resin varnish 4 ... Dip roll 5 ... Squeeze roll 6 ... Dryer 7 ... Prepreg 8 ... Upper roll 10 ... Metal foil with an insulating resin layer 11 ... Metal foil 12 ... Insulating resin layer 20 ... Base material 30 ... polymer film sheet with insulating resin layer 31 ... polymer film sheet 32 ... insulating resin layer 40 ... prepreg 41 ... prepreg with metal foil 42 ... prepreg with polymer film sheet 51 ... metal-clad laminate 52 ... metal-clad Laminated board

Claims (9)

(A) Epoxy resin, (B) Polyvinyl acetal resin, (C) Epoxy resin composition for printed wiring boards, characterized by having fine particles having an average particle diameter of 5 to 120 nm as essential components. 2. The epoxy resin composition for a printed wiring board according to claim 1, wherein the (B) polyvinyl acetal resin has 15 to 30 mol% of a hydroxyl group in 1 mol of the (B) polyvinyl acetal resin. The epoxy resin composition for printed wiring boards according to claim 1 or 2, wherein the epoxy resin composition for printed wiring boards further comprises (D) a cyanate resin. A prepreg obtained by impregnating a base material with the epoxy resin composition for a printed wiring board according to any one of claims 1 to 3. 5. A metal-clad laminate comprising a metal foil on at least one side of the prepreg according to claim 4 or a laminate in which two or more prepregs are stacked. The resin sheet formed by forming the insulating layer which consists of an epoxy resin composition for printed wiring boards as described in any one of Claims 1 thru | or on a film or metal foil.   A printed wiring board comprising the prepreg according to claim 4 or the metal-clad laminate according to claim 5 as an inner circuit board. A printed wiring board obtained by laminating the prepreg according to claim 4 and / or the resin sheet according to claim 6 on the inner layer circuit board on the circuit of the inner layer circuit board. 9. A semiconductor device comprising a semiconductor element mounted on the printed wiring board according to claim 7 or 8.