JP2012131946A - Resin composition for printed wiring board, prepreg, 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 can make a prepreg in which impregnation to a substrate is excellent, and which is excellent in heat radiation, low thermal expansion, drilling nature, and reliability, further to provide a prepreg made by using the resin composition for a printed wiring board, a laminate made by using the resin composition for a printed wiring board or the prepreg, a printed wiring board made by using at least one of the laminate, the prepreg, and the composition for a printed wiring board, and a semiconductor device made by using the printed wiring board having excellent performance.SOLUTION: The resin composition for a printed wiring board includes (A) an epoxy resin, and (B) an inorganic filler as essential components, wherein (B) the inorganic filler includes (b1) amorphous boron nitride, (b2) amorphous boehmite, and (b3) inorganic fine particles having an average particle diameter of 5-100 nm as essential components.

Description

  The present invention relates to a resin composition for a printed wiring board, a prepreg, a laminated board, 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, a printed wiring board that satisfies basic requirements such as workability and can form a fine conductor pattern with high density is particularly required to have excellent low thermal expansion, drill workability, and reliability.

A prepreg used for the production of a printed wiring board is generally prepared by dissolving a resin composition mainly composed of a thermosetting resin such as an epoxy resin in a solvent to make a varnish, impregnating this into a base material, and drying by heating. It is produced by making it. Conventionally, a resin composition containing an inorganic filler to improve the heat resistance, low thermal expansion and the like of a prepreg, or a resin composition containing a flexible component to improve the drill workability of a prepreg, etc. The prepreg has been produced by using it.

For example, the epoxy resin composition disclosed in Patent Document 1 has an epoxy resin, a curing agent, an inorganic filler containing aluminum hydroxide or spherical silica and aluminum hydroxide, a core-shell structure, and the shell portion is the epoxy resin. Containing a flexible component composed of fine particles composed of a resin compatible with the resin, and having a thermal expansion coefficient of 48 or less in the thickness (Z) direction in a cured state, using the epoxy resin composition It is described that the laminate produced in this way has good dimensional stability and drilling workability, and the generation of cracks during drilling is suppressed.

JP 2009-74036 A

However, since the varnish of the resin composition containing a large amount of inorganic filler fine particles or flexible component fine particles has a high viscosity, the substrate is impregnated with a sufficient amount of the resin composition, and the fine particles are uniformly dispersed. It was difficult to impregnate.
For this reason, it is difficult to contain a large amount of inorganic filler, it is excellent in low expansibility, and it has not been possible to obtain a laminate that is excellent in all of drilling workability and reliability.

The present invention has been accomplished in view of the above circumstances, and an object of the present invention is to provide a prepreg having excellent impregnation into a substrate, excellent in low thermal expansion, drilling workability, and reliability, and a stretched laminate. It is providing the resin composition for printed wiring boards which can produce a board.

The above object is achieved by the present invention described in the following [1] to [12].
[1] A printed wiring board resin composition comprising (A) an epoxy resin and (B) an inorganic filler, wherein (B) the inorganic filler comprises (b1) amorphous boron nitride, (b2) A resin composition for a printed wiring board, comprising: regular boehmite; and (b3) inorganic fine particles having an average particle diameter of 5 to 100 nm as essential components.
[2] The resin composition for a printed wiring board according to [1], wherein the (A) epoxy resin is an epoxy resin having at least one structure selected from the group consisting of a naphthalene structure, a biphenyl structure, and an anthracene structure. .
[3] The resin composition for an epoxy resin assembled printed wiring board according to the above [1] or [2], wherein the resin composition for a printed wiring board further contains a cyanate resin.
[4] (b3) The inorganic fine particles having an average particle diameter of 5 to 100 nm are in a total volume of 100 parts by volume of (B1) amorphous boron nitride and (b2) amorphous boehmite in the inorganic filler (B). The resin composition for printed wiring boards according to any one of [1] to [3], which is 1 to 40 parts by volume.
[5] The resin composition for a printed wiring board according to any one of [1] to [4], wherein the (B) inorganic filler further contains (b4) substantially cubic boehmite.
[6] The amount of the inorganic filler (B) is 55 to 90% by weight in the resin composition for printed wiring boards, according to any one of [1] to [5] above. Resin composition.
[7] A prepreg obtained by impregnating a substrate with the resin composition for printed wiring boards according to any one of [1] to [6].
[8] A laminate having a metal foil on at least one side of the prepreg according to [7] or a laminate in which two or more prepregs are laminated.
[9] A resin sheet obtained by forming an insulating layer made of the resin composition for printed wiring boards according to any one of [1] to [6] on a film or a metal foil.
[10] A printed wiring board comprising the laminated board according to [8] above as an inner circuit board.
[11] A printed wiring board obtained by laminating the prepreg according to [7] and / or the resin sheet according to [9] on a circuit of an inner layer circuit board.
[12] A semiconductor device comprising a semiconductor element mounted on the printed wiring board according to the above [10] or [11].

According to the present invention, (b1) amorphous boron nitride, (b2) amorphous boehmite, and (b3) inorganic fine particles having an average particle diameter of 5 to 100 nm are contained as essential components in the resin composition for printed wiring boards. Thus, the varnish of the resin composition for printed wiring boards has a low viscosity state on a substrate such as glass fiber (b1) amorphous boron nitride, (b2) amorphous boehmite, and (b3) average particle diameter A large amount of 5 to 100 nm inorganic fine particles can be impregnated.
Moreover, the impregnation property to the base material of the said resin composition for printed wiring boards becomes favorable. A prepreg produced using the resin composition for printed wiring boards is excellent in low thermal expansion, drill workability, and reliability.
Furthermore, the printed wiring board which is excellent in performance can be obtained using at least any one of the laminate, the prepreg, and the resin composition. Further, according to the present invention, a semiconductor device having excellent performance can be obtained using the printed wiring board.

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 laminated board of this invention. It is the schematic which shows another example of the manufacturing method of the laminated board of this invention.

(Resin composition for printed wiring boards)
First, the resin composition for printed wiring boards will be described.
The resin composition for printed wiring boards of the present invention is a resin composition for printed wiring boards containing (A) an epoxy resin and (B) an inorganic filler as essential components, and (B) the inorganic filler is (b1). The printed wiring board is made to contain a combination of (a) amorphous boron nitride, (b2) amorphous boehmite, and (b3) inorganic fine particles having an average particle diameter of 5 to 100 nm. A large amount of the inorganic filler can be contained in a state where the resin composition varnish has a low viscosity.
In addition, (b1) amorphous boron nitride and (b2) amorphous boehmite both have low elastic modulus and low hardness, and therefore have excellent drill wear.
Furthermore, (b3) inorganic fine particles having an average particle diameter of 5 to 100 nm can increase the filling of the inorganic filler, increase the impregnation property of the fiber base material, and improve the moldability of the laminate. Therefore, the expansion coefficient of the entire cured product of the resin composition for printed wiring boards can be lowered, and drill wear resistance can be lowered. Moreover, it is excellent also in heat dissipation and a flame retardance.

Examples of the (b1) amorphous boron nitride include boron nitride having a granular shape (substantially cubic shape), a short shape, a scale shape, a needle shape, or a crushed shape. (B1) The shape of the amorphous boron nitride is not particularly limited, but is preferably granular or scaly from the viewpoint of heat dissipation. The particle size is preferably an average particle diameter of 0.1 to 10 μm from the viewpoint of drill hole position accuracy and the inner wall surface roughness after drilling. From the viewpoint of dispersibility and impregnation, it is more preferably 0.5 to 5 μm.

Examples of the shape of the (b2) irregular boehmite include granular shapes (substantially cubic shapes), short shapes, scale shapes, needle shapes, and crushed shapes. (B2) The shape of the irregular boehmite is not particularly limited, but granular and scale-like are preferable from the viewpoint of heat dissipation. In particular, (b1) a combination of shapes different from the amorphous boron nitride is preferable. More preferred is a combination of (b1) granular boron nitride and (b2) flaky boehmite, or (b1) flaky boron nitride and (b2) granular (substantially cubic) boehmite. By combining different shapes, it is possible to improve heat dissipation and improve the discharge of cutting powder during drilling, thereby reducing drill bit breakage.

The particle diameter of the (b2) irregular boehmite is not particularly limited, but an average particle diameter of 0.1 to 8 μm is preferable from the viewpoint of drill hole position accuracy and the inner wall surface roughness after drilling. Moreover, it is preferable that it is an average particle diameter of 0.5-5 micrometers from a dispersible and impregnable viewpoint.

The content of the (b1) amorphous boron nitride and the (b2) amorphous boehmite is not particularly limited, but in terms of weight ratio, (b1) amorphous boron nitride: (b2) amorphous boehmite = The ratio is preferably 10:90 to 90:10, and particularly preferably 20:80 to 80:20 from the viewpoint of thermal conductivity.

By containing the inorganic fine particles (b3) having an average particle diameter of 5 to 100 nm in the resin composition for printed wiring boards, a large amount of inorganic filler can be uniformly impregnated in the substrate.
Therefore, the coefficient of thermal expansion of the prepreg or the laminate can be made smaller than before. (B3) The inorganic fine particles having an average particle diameter of 5 to 100 nm are not particularly limited. For example, silicates such as talc, fired talc, fired clay, unfired clay, mica and glass, titanium oxide, alumina, silica, and 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, borate such as sodium borate, nitrides such as aluminum nitride, boron nitride, silicon nitride, carbon nitride, strontium titanate, titanate Examples thereof include titanates such as barium. One of these can be used alone, or two or more can be used in combination.
Among these, silica, titanium oxide, barium sulfate, and the like are preferable from the viewpoint of lowering the linear thermal expansion coefficient of the laminate.

The shape of the inorganic fine particles (b3) having an average particle diameter of 5 to 100 nm is preferably spherical. Here, the spherical shape means that having a sphericity of 0.8 or more. The closer to 1.0, the closer to a true sphere. As a calculation method, for example, a photograph is taken with an SEM, and is calculated as a value calculated by (sphericity) = {4π × (area) ÷ (perimeter length) ² } from the area and circumference of the observed particle. To do. Specifically, an average value measured for 100 particles using an image processing apparatus is employed. This improves the impregnation of the substrate. The method for making the sphere is not particularly limited. For example, in the case of silica, the sphere 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 content of the (b3) fine particles having an average particle diameter of 5 to 100 nm is not particularly limited, but the total of (b1) amorphous boron nitride and (b2) amorphous boehmite in (B) inorganic filler is 100. The volume is preferably 1 to 40 parts by volume with respect to a total of 100 parts by volume of (b1) amorphous boron nitride and (b2) amorphous boehmite. More preferably, it is 5 to 25 parts by volume. Thereby, it is excellent in the dispersibility of an inorganic filler and the impregnation property to a base material.

In addition to (b1) amorphous boron nitride, (b2) amorphous boehmite, and (b3) inorganic fine particles having an average particle diameter of 5 to 100 nm, the (B) inorganic filler is further added with other fillers. Also good.
Other fillers are not particularly limited, and examples thereof include boehmite, silica, aluminum hydroxide, talc, silicone powder, and rubber particles having different shapes. Among these, (b4) granular (substantially cubic) boehmite is preferable. When (b4) substantially cubic boehmite is used, (b2) an irregular boehmite is preferably a scaly shape. Thereby, it is excellent in heat dissipation.

The content of the inorganic filler (B) is not particularly limited, but is preferably 20 to 80% by weight based on the solid content of the entire resin composition for printed wiring boards, and has low thermal expansion, insulation reliability, and From the viewpoint of moldability, it is particularly preferably 45 to 75% by weight.

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 resins), phenol novolac type epoxy resins, cresol novolac type epoxy resins, etc. novolak type epoxy resins, biphenyl type epoxy resins, xylile Type epoxy resin, phenol aralkyl type epoxy resin, biphenyl aralkyl type epoxy resin, biphenyl dimethylene type epoxy resin, trisphenol methane novolak type epoxy resin, glycidyl ethers of 1,1,2,2- (tetraphenol) ethane, 3 Functional or tetrafunctional glycidylamines, arylalkylene type epoxy resins such as tetramethylbiphenyl type epoxy resin, naphthalene type epoxy resin such as naphthalene skeleton modified epoxy resin, methoxynaphthalene modified cresol novolac type epoxy resin, methoxynaphthalene dimethylene type epoxy resin Epoxy resin, anthracene type epoxy resin, phenoxy type epoxy resin, dicyclopentadiene type epoxy resin, norbornene type epoxy resin, adamantane type epoxy resin, full Ren type epoxy resin, flame-retardant 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 novolak type epoxy resins is preferable. Thereby, heat resistance and a flame retardance are improved.

Although content of the said (A) epoxy resin is not specifically limited, It is preferable to set it as 20 to 80 weight% on the solid content basis of the resin composition for printed wiring boards whole. When the content is less than the lower limit, the curability of the epoxy resin may be reduced, or the moisture resistance of the prepreg obtained from the printed wiring board resin composition or the printed wiring board may be reduced. 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 point is lowered, and if it exceeds the upper limit, the fluidity is lowered and the substrate may not be impregnated. By setting the weight average molecular weight within the above range, the impregnation property can be improved.
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.

Although the resin composition for printed wiring boards of this invention is not specifically limited, It is preferable that cyanate resin is included. 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 novolak type cyanate resin, bisphenol A type cyanate resin, bisphenol E type cyanate resin, bisphenol type cyanate resin such as tetramethylbisphenol F type cyanate resin, and naphthol aralkyl type cyanate resin. Can be mentioned.

  The cyanate resin preferably has two or more cyanate groups (—O—CN) in the molecule. For example, 2,2′-bis (4-cyanatophenyl) isopropylidene, 1,1′-bis (4-cyanatophenyl) ethane, bis (4-cyanato-3,5-dimethylphenyl) methane, 3-bis (4-cyanatophenyl-1- (1-methylethylidene)) benzene, dicyclopentadiene type cyanate ester, phenol novolac type cyanate ester, bis (4-cyanatophenyl) thioether, bis (4-cyanato) Phenyl) ether, 1,1,1-tris (4-cyanatophenyl) ethane, tris (4-cyanatophenyl) phosphite, bis (4-cyanatophenyl) sulfone, 2,2-bis (4-si Anatophenyl) propane, 1,3-, 1,4-, 1,6-, 1,8-, 2,6- or 2,7-dicyanatonaphthalene, 1 Cyanate resin obtained by reaction of 3,6-tricyanatonaphthalene, 4,4-dicyanatobiphenyl, phenol novolac type, cresol novolac type polyhydric phenols with cyanogen halide, naphthol aralkyl type polyvalent naphthol And cyanate resin obtained by the reaction of a halogenated cyanide. 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 ester are used to control 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 resin composition for a printed wiring board. 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, particularly preferably based on the solid content of the entire resin composition for printed wiring boards. Is from 10 to 40% by weight. When the content is within the above range, the cyanate resin can effectively exhibit heat resistance and flame retardancy. If the content of the cyanate resin is less than the lower limit, the thermal expansibility may increase, and the heat resistance may decrease.If the content exceeds the upper limit, the strength of the prepreg produced using the resin composition for a printed wiring board is increased. May decrease.

Moreover, although the 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 3 to 25% by weight, and still more preferably based on the solid content of the resin composition for printed wiring boards. 5 to 20% by weight.

  Furthermore, the resin composition for printed wiring boards 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.

  A phenolic curing agent can be used for the resin composition for printed wiring boards of the present invention. 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, The 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 resin composition for a printed wiring board of the present invention can be added with additives other than the above components as necessary within a range that does not impair the characteristics. 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 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, a slurry in which the inorganic filler (B) is dispersed in a solvent is prepared, and other components of the resin composition for printed wiring boards are added to the slurry. Examples thereof include a method in which the solvent is added and dissolved and mixed. (B3) Since the inorganic fine particles having an average particle diameter of 5 to 100 nm are likely to aggregate and often aggregate secondarily when blended in the resin composition, a slurry-like one may be used in advance. Such secondary aggregation can be prevented and dispersibility is improved.

  The solvent is not particularly limited, but a solvent that exhibits good solubility in the resin composition for a printed wiring board is preferable, for example, cyclohexanone, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, dimethylformamide, Examples thereof include dimethylacetamide and N-methylpyrrolidone. In addition, you may use a poor solvent in the range which does not exert a bad influence.

  Although the solid content of the resin composition for printed wiring boards contained in the varnish is not particularly limited, it is preferably 30 to 80% by weight, particularly preferably 40 to 70% by weight. Thereby, the impregnation property to the base material of the resin composition for printed wiring boards can be improved.

(Resin sheet)
Next, the resin sheet will be described.
The resin sheet of the present invention is formed by forming an insulating layer made of the resin composition for printed wiring board on a metal foil or a film.
Here, the method for forming the insulating layer made of the resin composition for a printed wiring board on a metal foil or film is not particularly limited. For example, the resin composition for a printed wiring board is dissolved and dispersed in a solvent or the like. After preparing a resin varnish and applying the resin varnish to the substrate using various coating devices, drying the resin varnish on the substrate with a spray device, drying the resin varnish The method of doing is mentioned.

  The solvent used in the resin varnish desirably exhibits good solubility in the resin component in the resin composition for printed wiring boards, but a poor solvent may be used as long as it does not adversely affect the resin varnish. . Examples of the solvent exhibiting good solubility include acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, tetrahydrofuran, dimethylformamide, dimethylacetamide, dimethyl sulfoxide, ethylene glycol, cellosolve and carbitol.

  Although it does not specifically limit as solid content in the said resin varnish, 10 to 70 weight% is preferable and 20 to 55 weight% is especially preferable.

  When the resin sheet of the present invention has two or more insulating layers, at least one of them is preferably the resin composition of the present invention. Moreover, it is preferable that the insulating layer which consists of a resin composition for printed wiring boards of this invention forms the resin layer which consists of a resin composition of this invention directly on metal foil or a film. By doing so, the insulating layer made of the resin composition of the present invention can exhibit a high plating peel strength with the outer layer circuit conductor during the production of the printed wiring board.

The insulating layer made of the resin composition for a printed wiring board of the present invention preferably has a thickness of 0.5 to 10 μm. By setting the thickness of the insulating layer within the above range, high adhesion with the conductor circuit can be obtained.

  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.

(Prepreg)
Next, the prepreg will be described.
The prepreg of the present invention is obtained by impregnating a substrate with the resin composition for printed wiring board and drying by heating. Since the resin composition for printed wiring boards of the present invention contains (b1) amorphous boron nitride and (b2) amorphous boehmite (b3) inorganic fine particles having an average particle diameter of 5 to 100 nm, A resin composition for printed wiring boards having a low level can be obtained, and a prepreg in which a base material is impregnated with a larger amount of filler can be obtained.
Moreover, the obtained prepreg is excellent in low thermal expansion property, drill workability, reliability, flame retardancy, and desmear resistance.

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 for impregnating the substrate with the resin composition for printed wiring board is not particularly limited. For example, a method of immersing the substrate in a varnish of the resin composition for printed wiring board, a method of applying with various coaters, and spraying. The method of spraying etc. are mentioned. Among these, the method of immersing a base material in the varnish of the resin composition for printed wiring boards is preferable. Thereby, the impregnation property of the resin composition for printed wiring boards with respect to a base material improves. In addition, when a base material is immersed in the varnish of the 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 resin composition to produce a prepreg 7. To do. 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.

(Laminated board)
Next, a laminated board is demonstrated.
The laminate of the present invention has a metal foil on at least one surface of a resin-impregnated substrate layer formed by impregnating a substrate with the above resin composition for printed wiring board.
The 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 superposing 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 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 laminate of the present invention is a method for producing a 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 laminated plate 51 can be obtained by directly heat-pressing the prepreg 41 with metal foil (FIG. 2C).

Furthermore, as another method for producing the laminate of the present invention, a laminate production method 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. 3C), the metal foil 11 is arranged on the surface from which the polymer film sheet 31 is peeled (FIG. 3D). )), The laminated plate 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 laminated sheet can be obtained by placing 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 laminate obtained by such a production method has high thickness accuracy, uniform thickness, and excellent surface smoothness.
In addition, since a laminated board with small molding strain can be obtained, a printed wiring board and a semiconductor device manufactured using the laminated board 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 laminated board of FIGS. 2-3 etc. is not specifically limited, For example, it manufactures using the apparatus which manufactures the metal foil with an insulating resin layer, and the apparatus which manufactures a laminated board.
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 the manufacturing method such as FIGS. 2 to 3 is used, since the control of the uniform resin amount and the in-plane thickness accuracy are superior to the manufacturing method impregnating the varnish of FIG. Small and yield is improved.

Moreover, when a laminated board is obtained by such a manufacturing method, it is necessary to consider the impregnation property to the fiber base material directly rather than the varnish melt | dissolved and disperse | distributed in the solvent. Since the inorganic filler (E) uses fine particles having an average particle diameter of 5 to 100 nm, particularly the impregnation property to the fiber base material is improved, the flow of the resin composition in the laminated plate is increased during the heat and pressure molding. Since the non-uniform movement of the molten resin is suppressed, streaky unevenness on the surface of the laminated plate can be prevented and the thickness can be made uniform.

(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 laminated board as an inner layer circuit board.
Moreover, the printed wiring board of this invention uses said prepreg 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 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 film made of the resin composition for a printed wiring board of the present invention can be used. In addition, when using the resin film which consists of the said prepreg or the said resin composition for printed wiring boards as said insulating layer, the said inner layer circuit board does not need to consist of a 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 laminated board of the present invention is 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 side or both sides of the 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, the prepreg and the inner layer circuit board are combined and subjected to vacuum heating and pressing using a vacuum pressurizing laminator device or the like, and then the insulating layer is heated and cured using a hot air drying device or the like. Although it does not specifically limit as conditions to heat-press form here, If an example is given, it can implement at the temperature of 60-160 degreeC, and the pressure of 0.2-3 MPa. Moreover, it is although it does not specifically limit as conditions to carry out heat hardening, If an example is given, it can implement in temperature 140-240 degreeC and time 30-120 minutes.

In the next step, laser is irradiated to form an opening in the insulating layer, but it is necessary to peel off the substrate before that. There is no particular problem in peeling the base material either after the insulating layer is formed, before heat curing, or after heat curing.

  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.

(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.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail based on an Example and a comparative example, this invention is not limited to this.

The raw materials used in Examples and Comparative Examples are as follows.
(1) Epoxy resin A: Naphthalene-modified cresol novolac type epoxy resin (HP-5000 manufactured by DIC, epoxy equivalent 250)
(2) Epoxy resin B: Biphenyl dimethylene type epoxy resin (Nippon Kayaku Co., Ltd. NC-3000, epoxy equivalent 275)
(3) Phenol-based curing agent: biphenylalkylene type novolak resin (“MEH-7851-4L, hydroxyl group equivalent 187” manufactured by Meiwa Kasei Co., Ltd.)
(4) Cyanate resin A: Novolac-type cyanate resin (Lonza Japan Co., Ltd. Primaset PT-30, cyanate equivalent 124)
(5) Boron nitride A: scaly shape (Showa Denko Co., Ltd. Show NU UHP-1, average particle size of 8-10 μm μm crushed with a ball mill to an average particle size of 5 μm)
(6) Boron nitride B: scaly (SP-7 manufactured by Denki Kagaku Kogyo Co., Ltd., average particle size 1.4 μm)
(7) Boron nitride C: granular (spherical grate (FS-3) manufactured by Mizushima Tekko Co., Ltd. was pulverized with a ball mill to have an average particle diameter of 4 μm)
(8) Fine particles having an average particle diameter of 5 to 100 nm: spherical silica (NSS-5N manufactured by Tokuyama Corporation, average particle diameter of 75 nm)
(9) Fine particles having an average particle diameter of 5 to 100 nm: Barium sulfate (BF-21 manufactured by Sakai Chemical Industry Co., Ltd., average particle diameter of 50 nm)
(10) Fine particles having an average particle diameter of 5 to 100 nm: Titanium oxide (ST410WB manufactured by Titanium Industry Co., Ltd., average particle diameter of 20 nm)
(11) Boehmite A: scaly (BMF manufactured by Kawai Lime Co., Ltd., average particle size: 4.0 μm)
(12) Boehmite B: substantially cubic shape (BMB, Kawai Lime Co., Ltd., average particle size 0.5 μm)
(13) Curing accelerator: 2-ethyl-4-methylimidazole (2E4MZ manufactured by Shikoku Chemicals)

Example 1
(1) Preparation of resin composition-containing varnish for printed wiring board First, as (A) epoxy resin, 22 parts by weight of naphthalene skeleton-containing epoxy resin A, 12 parts by weight of phenolic curing agent, (b1) amorphous 30 parts by weight of flaky boron nitride A as boron nitride, (b2) 30 parts by weight of flaky boehmite A as amorphous boehmite, (b3) spherical silica particles as inorganic fine particles having an average particle diameter of 5 to 100 nm 6 parts by weight and 0.5 part by weight of a curing accelerator were dissolved and mixed in methyl ethyl ketone and stirred using a high-speed stirrer to obtain a varnish having a resin composition of 70% by weight based on solid content. .

(2) Preparation of prepreg The varnish was impregnated into a glass woven fabric (thickness 87 μm, Nittobo E glass woven fabric, WEA-2116) and dried in a heating furnace at 180 ° C. for 2 minutes to obtain a resin composition in the prepreg. A prepreg having a solid content of about 50% by weight was obtained.

(3) Fabrication of laminated plate Four prepregs are stacked, and 12 μm copper foil (3EC-VLP foil, manufactured by Mitsui Mining & Smelting Co., Ltd.) is stacked on both sides of the prepreg, followed by heat pressing for 2 hours at a pressure of 3 MPa and a temperature of 220 ° C. And the laminated board which has a copper foil on both surfaces of thickness 0.130mm was obtained.

(4) Production of Printed Wiring Board Using the laminate having copper foil on both sides, a drilling machine was used to form a through hole, and then conduction between the upper and lower copper foils was achieved by electroless plating.
In addition, between through-hole walls, in order to evaluate the insulation reliability between through-hole walls, there is a 0.2 mm portion between through-hole walls.
L (conductor circuit width (μm)) / S (interconductor circuit width (μm)) = 50/50) in which inner layer circuits were formed on both surfaces by etching the copper foils on both sides.
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.

Next, the prepreg was laminated on the inner layer circuit using a vacuum laminating apparatus, and was cured by heating at a temperature of 170 ° C. for 60 minutes to obtain a laminated body.
Thereafter, an opening (blind via hole) having a diameter of 60 μm is formed on the prepreg of the obtained laminate using a carbonic acid laser device (manufactured by Hitachi Via Mechanics Co., Ltd .: LG-2G212), and a swelling liquid at 70 ° C. (Atotech Japan Co., Swelling Dip Securigant P) for 5 minutes, and further immersed in an 80 ° C. potassium permanganate aqueous solution (Atotech Japan Co., Ltd., Concentrate Compact CP) for 10 minutes, neutralized and roughened The treatment was performed.
Next, after the steps of degreasing, applying a catalyst, and activating, a power supply layer of about 0.5 μm was formed by an electroless copper plating film. 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.
The connection electrode portion of the printed wiring board corresponding to the solder bump arrangement of the semiconductor element was subjected to ENEPIG treatment.
ENEPIG treatment includes [1] cleaner treatment, [2] soft etching treatment, [3] pickling treatment, [4] pre-dip treatment, [5] palladium catalyst application, [6] electroless nickel plating treatment, [7] The electroless palladium plating treatment and [8] electroless gold plating treatment were performed.

(5) Manufacture of Semiconductor Device A printed wiring board subjected to ENEPIG treatment was cut into a size of 50 mm × 50 mm and used. A semiconductor element (TEG chip, size 15 mm × 15 mm, thickness 0.8 mm) has a solder bump formed of a eutectic of Sn / Pb composition, and a circuit protective film of the semiconductor element is a positive photosensitive resin (Sumitomo Bakelite). What was formed by the company make, CRC-8300) was used. In assembling the semiconductor device, first, a flux material was uniformly applied to the solder bumps by a transfer method, and then mounted on a printed wiring board by thermocompression bonding using a flip chip bonder device. Next, after solder bumps were melt-bonded in an IR reflow furnace, a liquid sealing resin (manufactured by Sumitomo Bakelite Co., Ltd., CRP-4152S) was filled and the liquid sealing resin was cured to obtain a semiconductor device. The effect condition of the liquid sealing resin was a temperature of 150 ° C. for 120 minutes.

<Examples 2 to 5 and Comparative Examples 1 to 4>
A prepreg, a laminate, a printed wiring board, a multilayer printed wiring board, and a semiconductor device were obtained in the same manner as in Example 1 with the blending amounts in Table 1.
The following evaluation items were evaluated for the prepreg, laminate, multilayer printed wiring board, and semiconductor device obtained above. In addition, Tables 1 and 2 show the blending compositions of the resin compositions of Examples and Comparative Examples, each physical property value, and evaluation results. In the table, each compounding amount represents “parts by weight”.

<Examples 6 to 11>
Varnishes were produced with the blending amounts shown in Table 1, and printed wiring boards and semiconductor devices were obtained in the same manner as in Example 1.
In addition, the prepreg and the laminated board were made with the following method.
Tables 1 and 2 show the composition of the resin compositions of Examples and Comparative Examples, each physical property value, and evaluation results. In the table, each compounding amount represents “part by weight”.

(2) Preparation of prepreg The varnish obtained in the examples was cast on a 38 μm polyethylene terephthalate substrate (hereinafter referred to as PET substrate), and the solvent was evaporated and dried at a temperature of 140 ° C. for 10 minutes. The thickness of the resin layer was set to 30 μm. The base material with a resin layer is arranged so that the resin layer is in contact with the glass woven fabric on both surfaces of a glass woven fabric (thickness 87 μm, Nittobo E glass woven fabric, WEA-2116), and a pressure of 0.5 MPa, A pressure and pressure laminator (MLVP-500 manufactured by Meiki Seisakusho Co., Ltd.) was heated and pressurized under the condition of a temperature of 140 ° C. for 1 minute to impregnate the resin composition to obtain a prepreg having a PET base on both sides.

(3) Production of Laminate Next, four prepregs from which the PET base material on both sides was peeled were stacked, and 12 μm copper foil (3EC-VLP foil made by Mitsui Kinzoku Mining Co., Ltd.) was stacked on both sides, pressure 1 MPa, temperature Heat-press molding was performed at 220 ° C. for 2 hours to obtain a laminate having copper foil on both sides of the insulating resin layer having a thickness of 0.4 mm.

The contents of the evaluation items performed to obtain the results shown in Table 2 are shown below.

(1) Sedimentability of inorganic fillers Sedimentability of inorganic fillers (fillers) is determined by rotating the varnish into a 250 cc plastic bottle (65 mm in diameter) using a stirring blade with a diameter of 50 mm. The mixture was stirred at several 500 rpm for 30 minutes.
Then, the plastic bottle was left still. When the milky varnish separated and a transparent part appeared after 24 hours, the thickness of the transparent part (hereinafter referred to as “separation layer”) was measured and evaluated.
In addition, when it isolate | separated 24 hours later and the separated layer appeared, it stirred again for 30 minutes at the rotation speed of 500 rpm using the stirring blade of diameter 50mm.
Each code is as follows.
A: The separation layer thickness was within 10 mm.
○: Although the separation layer thickness was 10 mm or more and within 30 mm, it was easily restored by re-stirring.
X: Separation layer thickness exceeded 30 mm, and sediment appeared at the bottom of the plastic bottle.

(2) Impregnating prepreg of prepreg or copper foil-prepared prepreg was observed at a temperature of 170 ° C. for 1 hour to observe a cross section (in the range of an arbitrary 500 mm width 500 mm of the cross section).
Each code is as follows.
◎: All impregnated ○: There is a minute unimpregnated portion in the monofilament, or less than 40% is not impregnated
X: 40% or more of the monofilament is not impregnated

(3) Linear thermal expansion coefficient The linear thermal expansion coefficient was measured using a TMA (thermomechanical analysis) apparatus (TA Instruments, Q400) to produce a 4 mm × 20 mm test piece, and a temperature range of 30 to 300. The linear expansion coefficient (CTE) at 50 to 100 ° C. in the second cycle was measured under the conditions of 10 ° C./min and a load of 5 g. In addition, a sample uses two prepregs obtained in each Example and Comparative Example, and the second resin layer is face-to-face and pressed and laminated under the conditions of a temperature of 220 ° C., a pressure of 1 MPa, and a time of 120 minutes. What removed the foil was used.

(4) Copper foil peeling strength The peeling strength of the copper foil of the laminated board which has a copper foil on both surfaces with a thickness of 0.4 mm of the said insulating resin layer was measured based on JIS C-6481.

(5) Moisture-absorbing solder heat resistance Based on JIS C-6481, all copper foils except for the back and front half of the 50 mm × 50 mm square sample were removed by etching, and 121 with a prescher cooker tester (Espec Corp.). After treatment at 2 ° C. for 2 hours, the sample was immersed in a solder bath at 260 ° C. for 30 seconds, and the presence or absence of an abnormality in the appearance change was visually observed.
Each code is as follows.
○: No abnormality ×: Swelling or peeling

(6) Drill wearability Three layers of the obtained laminates are stacked, and an entry board (LE812F3 manufactured by Mitsubishi Gas Chemical Company) is placed on top, and a backboard (paper phenol board with a thickness of 1.5 mm) is placed on the bottom. Drilling of φ150 using a drill bit (KMC L506, diameter 150 μm) manufactured by Tool Co., Ltd. under drilling conditions of a drill rotation speed of 200 krpm, a feed speed of 2.5 m / min, and a tip load of 12.5 μm / rev. Processing (through hole: 3000 holes) was performed.
Evaluation of drill wearability was performed by measuring the remaining ratio of the drill blade width after use with the drill blade width before use being 100%.
Each code is as follows.
A: When the remaining ratio of the drill blade width is 65% or more.
◯: When the remaining rate of the drill blade width is 50% or more and less than 65%.
X: When the remaining ratio of the drill blade width is less than 50%.

(7) Plating penetration The penetration penetration penetration after drilling was evaluated.
The sample was subjected to electroless plating on the through-holes drilled by drilling for the above-described evaluation of wear of the drill, plated with a thickness of 1 μm, and then plated with a thickness of 10 μm by electroplating. Thereafter, 10 through-holes were observed from the cross-section of 2500 to 3000 holes.
The code is as follows.
A: When the penetration depth is less than 5 μm.
○: When the penetration depth is 5 μm or more and less than 15 μm.
X: When the penetration depth is 15 μm or more.

(8) Insulation reliability between through-holes The insulation reliability between through-holes was evaluated using the printed wiring boards obtained in the examples and comparative examples. Using a 0.2 mm portion between through-hole walls of the printed wiring board, evaluation was made by continuous measurement under the conditions of an applied voltage of 20 V, a temperature of 130 ° C. and a humidity of 85%.
The process was terminated when the insulation resistance value was less than 10 ⁸ Ω.
Each code is as follows.
A: When 200 hours are exceeded.
○: When it is 100 hours or more and 200 or less.
X: When it was less than 100 hours.

As can be seen from the evaluation results shown in Table 2, in Examples 1 to 13, good results were obtained in the evaluations (1) to (8). That is, in Examples 1-13, it is excellent in the sedimentation property of the inorganic filler of a varnish, it is excellent in the impregnation property of a prepreg in spite of a high filler filling varnish, the low thermal expansion property of a laminated board, copper foil peeling strength, copper The foil was excellent in moisture absorption solder heat resistance. Moreover, it was excellent in the drill bit wear resistance of the drill bit and the plating penetration property of the through hole, which are the processing characteristics of the printed wiring board. Moreover, the insulation between the through holes of the printed wiring board was also excellent.
On the other hand, in Comparative Example 1, only silica having a high hardness and elastic modulus is used as the inorganic filler, so that the drill bit wear resistance and the plating penetration of the through hole, which are the processing characteristics of the printed wiring board, are used. Was inferior.
In Comparative Example 2, since only boron nitride was used as the inorganic filler, the copper foil peel strength of the laminated board, the moisture absorption solder heat resistance of the copper foil, the plating penetration property of the through holes, which are the processing characteristics of the printed wiring board, In addition, the insulation between the through holes of the printed wiring board was inferior.
In Comparative Example 3, since only boehmite was used as the inorganic filler, the low thermal expansion property of the laminated board and the insulation between the through holes of the printed wiring board were inferior.
In Comparative Example 4, since fine particles having an average particle diameter of 5 to 100 nm were not used in the preparation of the varnish, the sedimentation property of the inorganic filler of the varnish, the impregnation property of the prepreg, the peel strength of the copper foil, the moisture absorption solder heat resistance of the copper foil As a result, the processing characteristics of the printed wiring board were poor in plating penetration of through holes and insulation between through holes of the printed wiring board.

  The resin composition for printed wiring boards of the present invention can be used as a prepreg by impregnating a substrate such as a glass fiber substrate, and further as a laminate using the prepreg. Moreover, since the hardened | cured material of the resin composition for printed wiring boards of this invention has the outstanding insulation, it can be used suitably for the insulating layer of a printed wiring board, for example. Furthermore, the cured product of the epoxy resin precursor composition of the present invention has a low linear expansion and is excellent in heat resistance and adhesiveness with a conductor circuit, and therefore can be used as an interposer of a semiconductor device. Mother boards and interposers are known as printed wiring boards for semiconductor devices. The interposer is a printed wiring board similar to the mother board, but is interposed between the semiconductor element (bare chip) or the printed wiring board and the mother board and mounted on the mother board. The interposer may be used as a substrate on which a printed wiring board is mounted in the same manner as a mother board. However, the interposer is used as a package substrate or a module substrate as a specific usage method different from the mother board. The package substrate means that an interposer is used as a printed wiring board substrate. In the printed wiring board, a semiconductor element is mounted on a lead frame, both are connected by wire bonding and sealed with resin, and an interposer is used as a package substrate, and a semiconductor element is mounted on the interposer. Are connected by a method such as wire bonding and sealed with resin.

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 ... Substrate 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 ... laminate 52 ... laminate

Claims (12)

(A) A resin composition for a printed wiring board comprising an epoxy resin and (B) an inorganic filler,
(B) The inorganic filler contains (b1) amorphous boron nitride, (b2) amorphous boehmite, and (b3) inorganic fine particles having an average particle diameter of 5 to 100 nm as essential components. Resin composition for board. The resin composition for a printed wiring board according to claim 1, wherein the (A) epoxy resin is an epoxy resin having at least one structure selected from the group consisting of a naphthalene structure, a biphenyl structure, and an anthracene structure.   The resin composition for a printed wiring board according to claim 1, wherein the resin composition for a printed wiring board further contains a cyanate resin. The inorganic fine particles (b3) having an average particle size of 5 to 100 nm are 1 to 100 parts by volume in total of (B1) amorphous boron nitride and (b2) amorphous boehmite in the inorganic filler (B). The resin composition for a printed wiring board according to any one of claims 1 to 3, wherein the resin composition is 40 parts by volume. The printed wiring board resin composition according to any one of claims 1 to 4, wherein the (B) inorganic filler further includes (b4) substantially cubic boehmite. The resin composition for a printed wiring board according to any one of claims 1 to 5, wherein a blending amount of the (B) inorganic filler is 45 to 75% by weight in the resin composition for a printed wiring board. A prepreg comprising a substrate impregnated with the resin composition for printed wiring boards according to any one of claims 1 to 6. A laminate having a metal foil on at least one surface of the prepreg according to claim 7 or a laminate in which two or more prepregs are stacked. The resin sheet formed by forming the insulating layer which consists of a resin composition for printed wiring boards as described in any one of Claim 1 thru | or on a film or metal foil. A printed wiring board comprising the laminated board according to claim 8 as an inner circuit board. A printed wiring board obtained by laminating the prepreg according to claim 7 and / or the resin sheet according to claim 9 on a circuit of an inner layer circuit board. 12. A semiconductor device comprising a semiconductor element mounted on the printed wiring board according to claim 10 or 11.