JP2011105911A - Epoxy resin composition containing silicone rubber fine particle, prepreg, metal-clad laminate, printed wiring board, and semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an epoxy resin composition containing silicone rubber fine particles, which satisfactorily infiltrates into base materials and from which a prepreg having excellent flame retardancy, low thermal expansion property, drillability, and resistance to desmear is produced, and a metal-clad laminate in which occurrence of streak-shaped irregularity in its surface is extremely suppressed, is produced, to provide the prepreg produced by using the epoxy resin composition, to provide the metal-clad laminate produced by using the epoxy resin composition or the prepreg, to provide a printed wiring board produced by using at least one of the metal-clad laminate, the prepreg and the epoxy resin composition, and to provide a semiconductor device produced by using the printed wiring board and having excellent performance. <P>SOLUTION: The epoxy resin composition contains an epoxy resin, silicone rubber fine particles having an average particle diameter of 1-10 μm, boehmite fine particles having an average particle diameter of 0.2-5 μm, and silica nanoparticles having an average particle diameter of 10-100 nm. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a silicone rubber fine particle-containing epoxy resin composition (hereinafter sometimes simply referred to as “epoxy resin composition”), a prepreg, a metal-clad laminate, 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. Therefore, as a printed wiring board that satisfies basic requirements such as flame retardancy and can form a high-density and fine conductor pattern, it is particularly excellent in low thermal expansion and drill workability, and can perform desmear treatment well. Things are sought.

  A prepreg used for the production of a printed wiring board is generally a resin composition mainly composed of a thermosetting resin such as an epoxy resin dissolved in a solvent to form a varnish, which is impregnated into a base material and dried by heating. It is produced by making it. Conventionally, a resin composition containing an inorganic filler to improve the heat resistance, low thermal expansion, desmear resistance, etc. of a prepreg, or a resin containing a flexible component to improve the drill workability of a prepreg, etc. A prepreg is produced using the composition.

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. The epoxy resin composition is characterized in that it contains a flexible component composed of fine particles composed of a resin compatible with the resin and has a thermal expansion coefficient α _z in the thickness (Z) direction in a cured state of 48 or less. It is described that the laminate produced using the slab has good dimensional stability and drilling workability and suppresses the generation of cracks during drilling.

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. Difficult to impregnate, or unevenness of the prepreg and the pressure due to the fine particles may cause separation between the resin and the fine particles, resulting in streaky unevenness in the resulting metal-clad laminate. There is a point.

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 good impregnation into a base material and excellent in flame retardancy, low thermal expansion, drill workability, and desmear resistance. It is an object of the present invention to provide a silicone rubber fine particle-containing epoxy resin composition capable of producing a metal-clad laminate with very little occurrence of surface unevenness.
Another object of the present invention is to provide a prepreg produced using the silicone rubber fine particle-containing epoxy resin composition, a metal-clad laminate produced using the silicone rubber fine particle-containing epoxy resin composition or the prepreg, and the metal laminated plate. Another object of the present invention is to provide a printed wiring board produced using at least one of the prepreg and the epoxy resin composition, and a semiconductor device excellent in performance produced using the printed wiring board.

The above object is achieved by the present invention described in the following (1) to (13).
(1) It contains an epoxy resin, silicone rubber fine particles having an average particle size of 1 μm to 10 μm, boehmite fine particles having an average particle size of 0.2 μm to 5 μm, and silica nanoparticles having an average particle size of 10 nm to 100 nm. An epoxy resin composition.
(2) The epoxy resin composition according to (1), wherein the silicone rubber fine particles are core-shell structure particles in which a core portion made of silicone rubber is coated with a silicone resin.
(3) The epoxy resin composition according to the above (1) or (2), wherein the silica nanoparticles have an average particle diameter of 40 nm to 100 nm.
(4) The epoxy resin composition according to any one of (1) to (3), further including a cyanate resin.
(5) The epoxy resin composition according to any one of (1) to (4), further including a maleimide resin.
(6) The epoxy resin is at least one selected from the group consisting of a biphenyl aralkyl type epoxy resin, a naphthalene skeleton-modified epoxy resin, and a cresol novolac type epoxy resin, according to any one of the above (1) to (5) The epoxy resin composition as described.
(7) A prepreg obtained by impregnating a base material with the epoxy resin composition according to any one of (1) to (6) above.
(8) A metal having a metal foil on at least one surface of a resin-impregnated substrate layer obtained by impregnating the epoxy resin composition according to any one of (1) to (6) in a substrate. Tension laminate.
(9) The metal-clad laminate according to (8), which is obtained by superimposing metal foil on at least one surface of the prepreg according to (7) or a laminate obtained by superimposing two or more prepregs, and heating and pressing. .
(10) A printed wiring board comprising the metal-clad laminate according to (8) or (9) described above as an inner layer circuit board.
(11) A printed wiring board obtained by using the prepreg described in (7) as an insulating layer on an inner layer circuit.
(12) A printed wiring board obtained by using the epoxy resin composition according to any one of (1) to (6) as an insulating layer on an inner layer circuit.
(13) A semiconductor device comprising a semiconductor element mounted on the printed wiring board according to any one of (10) to (12).

  According to the present invention, by combining silicone rubber fine particles, boehmite particles, and silica nanoparticles into the epoxy resin composition, the varnish of the epoxy resin composition can contain the three types of particles in a low viscosity state. A large amount can be contained, and the impregnation property to the base material of the said epoxy resin composition is favorable. The prepreg produced using the epoxy resin composition is excellent in flame retardancy, low thermal expansion, drill workability, and desmear resistance. The metal-clad laminate produced using the epoxy resin composition or the prepreg has very little occurrence of streak-like unevenness on the surface. Furthermore, the printed wiring board which is excellent in performance can be obtained using at least any one of the metal laminate, the prepreg, and the epoxy 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 the example of each width direction dimension about the metal foil, the insulating resin layer, and base material which are used for an example of the manufacturing method of the metal-clad laminated board of this invention. (1) It is the photograph which image | photographed the surface of the metal foil layer of the metal-clad laminate obtained in Example 1, (2) The surface of the metal foil layer of the metal-clad laminate obtained in Comparative Example 1 was imaged. It is a photograph and (3) It is a figure explaining the photograph of the surface of the metal foil layer of a metal-clad laminate.

(Silicone rubber fine particle-containing epoxy resin composition)
First, the silicone rubber fine particle-containing epoxy resin composition will be described.
The epoxy resin composition containing silicone rubber fine particles of the present invention comprises an epoxy resin, silicone rubber fine particles having an average particle size of 1 μm to 10 μm, boehmite fine particles having an average particle size of 0.2 μm to 5 μm, and silica nano particles having an average particle size of 10 nm to 100 nm. And particles.
Silicone rubber fine particles, boehmite particles, and silica nanoparticles are used in combination in the epoxy resin composition, so that the varnish of the epoxy resin composition has a low viscosity and contains a large amount of the three types of particles. be able to. This is because silica nanoparticles having a negative surface zeta potential selectively adhere around boehmite particles having a positive surface zeta potential, and the repulsive force between the silicone rubber fine particles having the same surface zeta potential and the boehmite particles. This is because the varnish has a low viscosity even if it contains a large amount of particles.

  The silicone rubber fine particles are not particularly limited as long as they are elastic rubber fine particles formed of organopolysiloxane. For example, the fine particles made of silicone rubber (organopolysiloxane crosslinked elastomer) itself, and the core portion made of silicone rubber are made of silicone resin. And core-shell structured particles coated with. As the silicone rubber fine particles, KMP-605, KMP-600, KMP-597, KMP-594 (manufactured by Shin-Etsu Chemical Co., Ltd.), Trefill E-500, Trefil E-600 (manufactured by Toray Dow Corning Co., Ltd.) Commercial products such as these can be used.

  The silicone rubber fine particles have an average particle diameter of 1 to 10 μm and are preferably 1 to 5 μm from the viewpoint of excellent impregnation properties.

  The content of the silicone rubber fine particles is not particularly limited, but is preferably 5 to 50% by weight based on the solid content of the entire epoxy resin composition, and particularly 10 to 40% by weight from the viewpoint of excellent impregnation properties. It is preferable.

  The boehmite particles are monohydrates of aluminum oxide, and commercially available products such as AOH-30 (manufactured by Tesco Corporation) and BN-100 (manufactured by Kawai Lime Industry Co., Ltd.) can also be used.

  The boehmite particles have an average particle diameter of 0.2 to 5 μm, and 0.5 to 4 μm is preferable from the viewpoint of excellent impregnation properties.

  The content of the boehmite particles is not particularly limited, but is preferably 5 to 50% by weight based on the solid content of the entire epoxy resin composition, and particularly 10 to 40% by weight from the viewpoint of excellent impregnation properties. Is preferred.

  The silica nanoparticles have an average particle diameter of 10 to 100 nm, and 40 to 100 nm is preferable from the viewpoint of impregnation. This is because if the average particle size is less than 10 nm, the space between the filaments of the substrate cannot be expanded, and if it is greater than 100 nm, it may not be possible to enter between the filaments.

Although it does not specifically limit as said silica nanoparticle, For example, methods, such as combustion methods, such as VMC (Vaperized Metal Combution) method, PVS (Physical Vapor Synthesis) method, the melting method which flame-melts crushed silica, a sedimentation method, a gel method Can be used. Among these, the VMC method is particularly preferable. The VMC method is a method in which silica powder is formed by putting silicon powder into a chemical flame formed in an oxygen-containing gas, burning it, and then cooling it. In the VMC method, the particle diameter of the silica fine particles to be obtained can be adjusted by adjusting the particle diameter of the silicon powder to be input, the input amount, the flame temperature, and the like.
Commercially available products such as NSS-5N (manufactured by Tokuyama Co., Ltd.) and Sicastar 43-00-501 (manufactured by Micromod) can also be used.

  Although content of the said silica nanoparticle is not specifically limited, It is preferable that it is 1-10 weight% on the solid content basis of the whole epoxy resin composition, and it is especially preferable that it is 2-5 weight%. When the content is within the above range, the impregnation property is particularly excellent.

  The weight ratio of the content of the silicone rubber fine particles to the content of the silica nanoparticles (weight of the silicone rubber fine particles / weight of the silica nanoparticles) is not particularly limited, but is preferably 1 to 10, particularly 2 to 5. It is preferable that

  The weight ratio of the boehmite particle content to the silica nanoparticle content (boehmite particle weight / silica nanoparticle weight) is not particularly limited, but is preferably 1 to 50, and particularly 2 to 20. It is preferable.

  When the weight ratio of the content of the silicone rubber fine particles to the content of the silica nanoparticles and the weight ratio of the boehmite particles to the content of the silica nanoparticles are within the above ranges, the moldability is particularly good. If it is larger or smaller than the above range, the impregnation property is deteriorated, and the solder failure heat resistance and the insulation reliability are easily lowered due to the generation of voids.

  The average particle diameter of the silicone rubber fine particles, the boehmite particles, and the silica nanoparticles can be measured by, for example, a laser diffraction scattering method. The particles are dispersed in water by ultrasonic waves, and the particle size distribution of the particles is measured on a volume basis by a laser diffraction particle size distribution analyzer (manufactured by HOEIBA, LA-500), and the median diameter is defined as the average particle diameter. Specifically, the average particle diameter of the silicone rubber fine particles, boehmite particles, and silica nanoparticles is defined by D50 (median diameter).

  Furthermore, the epoxy resin composition of the present invention may contain an inorganic filler such as silica, aluminum hydroxide, and talc as long as the characteristics are not impaired.

Although it does not specifically limit as said epoxy resin, 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'-cyclohexyl) Diene 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), etc., novolac type epoxy resins such as phenol novolac type epoxy resin, cresol novolac 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 resins, naphthalene skeleton modified epoxy resins, methoxynaphthalene modified cresol novolak type epoxy resins, naphthalene type epoxies such as methoxynaphthalenedylene methylene type epoxy resins 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 are improved.

  Although content of the said epoxy resin is not specifically limited, It is preferable to set it as 5 to 30 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.

Although the weight average molecular weight of the said epoxy resin is not specifically limited, The weight average molecular weight 40-18000 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 epoxy resin composition 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 kind of the cyanate resin is not particularly limited. For example, bisphenol cyanate resin such as novolak type cyanate resin, bisphenol A type cyanate resin, bisphenol E type cyanate resin, tetramethylbisphenol F type cyanate resin, and naphthol aralkyl type. And cyanate resin.

  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 heating reaction or the like, and is preferably used for adjusting the moldability and fluidity of the epoxy resin composition. .
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, and particularly preferably 10 to 50% by weight based on the solid content of the entire epoxy resin composition. 40% by weight. When the content is within the above range, the cyanate resin can effectively exhibit heat resistance and flame retardancy. When the cyanate resin content is less than the lower limit, thermal expansibility increases and heat resistance may decrease. When the upper limit value is exceeded, the strength of the prepreg produced using the epoxy resin composition decreases. There is.

Moreover, although the epoxy resin composition 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.

  Although content of the said maleimide resin is not specifically limited, It is preferable that it is 1-30 weight% on the solid content basis of the whole epoxy resin composition, and 5-20 weight% is especially preferable.

  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 of the present invention can use a phenolic 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 zyloc type phenol resin, a terpene modified phenol resin, a polyvinyl phenol or the like may 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 epoxy resin composition of this invention can add additives other than the said component in the range which does not impair a characteristic as needed. 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 of the present invention is dissolved in a solvent and used as a varnish when preparing a prepreg. The method for preparing the varnish is not particularly limited. For example, a slurry in which the silicone rubber fine particles, the boehmite particles, the silica nanoparticles, and the inorganic filler are dispersed in a solvent is prepared, and the epoxy resin composition is added to the slurry. The method of adding the component of a thing, adding the said solvent, and making it melt | dissolve and mix etc. is mentioned. Nano-sized particles such as silica nanoparticles tend to aggregate and often form secondary agglomeration when blended with a resin composition. Secondary aggregation can be prevented and dispersibility is improved.

  The solvent is not particularly limited, but a solvent that exhibits good solubility in the epoxy resin composition is preferable. For example, MEK, cyclohexanone, MIBK, ANON, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, Examples include dimethylformamide, dimethylacetamide, and N-methylpyrrolidone. 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 30 to 80% by weight, and particularly preferably 40 to 70% by weight. Thereby, the impregnation property to the base material of an epoxy resin composition can be improved.

(Prepreg)
Next, the prepreg will be described.
The prepreg of the present invention is obtained by impregnating a base material with the epoxy resin composition and drying by heating. In the present invention, the epoxy resin composition contains a combination of silicone rubber fine particles, boehmite particles, and silica nanoparticles, so that the epoxy resin composition has a low viscosity despite containing a large amount of these particles. A prepreg in which the substrate is sufficiently impregnated with the epoxy resin composition can be obtained, and the obtained prepreg is excellent in flame retardancy, low thermal expansion, drill workability, and desmear resistance.

  Examples of the base material include glass fiber base materials such as glass woven fabric, glass non-woven fabric, and glass paper, paper, aramid, polyester, aromatic polyester, woven fabric and non-woven fabric made of synthetic fibers such as fluororesin, metal fibers, Examples thereof include woven fabrics, nonwoven fabrics and mats made of carbon fibers and mineral fibers. 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.

  Examples of the method of impregnating the base material with the epoxy resin composition include a method of immersing the base material in a varnish of the epoxy resin composition, a method of applying with various coaters, and a method of spraying with a spray. Among these, the method of immersing the base material in the varnish of the epoxy resin composition is preferable. Thereby, the impregnation property of the epoxy resin composition with respect to a base material can be improved. In addition, when a base material is immersed in the varnish of an epoxy resin composition, a normal impregnation coating equipment can be used. A prepreg can be obtained by impregnating the base material with the epoxy resin composition and drying at a predetermined temperature, for example, 90 to 180 ° C.

(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 the base material with the above epoxy resin composition.
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.

The metal-clad laminate of the present invention has a large flow because the varnish of the epoxy resin composition has a low viscosity, but the epoxy resin composition uses silicone rubber fine particles, boehmite particles, and silica nanoparticles in combination. By containing, the balance between the fluidity of these particles and the resin fluidity is good, the variation in pressure due to the particles is small due to the cushioning effect of the silicone rubber fine particles, and the surface stripe-like unevenness is very small.
2 shows (1) a photograph of the surface of the metal foil layer of the metal-clad laminate obtained in Example 1, and (2) the surface of the metal foil layer of the metal-clad laminate obtained in Comparative Example 1. It is a figure explaining the photographed photograph, and the photograph of the surface of the metal foil layer of (3) metal-clad laminates, and said (3) is the metal foil layer surface of a metal-clad laminate, and the said metal foil layer surface This represents the stripe-shaped unevenness that occurred. In the metal-clad laminate (1) of the present invention using an epoxy resin composition containing a combination of silicone rubber fine particles, boehmite particles, and silica nanoparticles, streaky unevenness is observed on the surface of the metal foil layer. In contrast, in the metal-clad laminate (2) using an epoxy resin composition that does not contain silicone rubber fine particles, boehmite particles, and silica nanoparticles in combination, the flow is particularly large in the vicinity of streaks. There are streaky irregularities on the surface of the metal foil layer.

  Although the temperature to heat is not specifically limited, 120-220 degreeC is preferable and especially 150-200 degreeC is preferable. Although the pressure to pressurize is not particularly limited, 0.5 to 5 MPa is preferable, and 1 to 3 MPa is particularly preferable. Moreover, you may perform post-curing at the temperature of 150-300 degreeC with a high temperature tank etc. as needed.

As another method, the metal-clad laminate of the present invention can also be produced by a method as described in WO2007 / 040125. In this method, (a) the insulating resin layer side of the metal foil with the first and second insulating resin layers formed with the insulating resin layer on one side is superposed on both sides of the substrate, and the pressure is reduced. A method for producing a metal-clad laminate, comprising: a step of bonding them, and (b) a step of heat treatment at a temperature equal to or higher than the melting temperature of the insulating resin after the bonding. The insulating resin layer is made of the epoxy resin composition of the present invention.
The pressure reducing condition in the step (a) is preferably a pressure reduced by 700 Torr or more from the normal pressure, and more preferably a condition reduced by 740 Torr or more from the normal pressure.
The heating temperature in the step (b) is a temperature equal to or higher than the melting temperature of the insulating resin, that is, a temperature equal to or higher than the melting temperature of the epoxy resin composition of the present invention. By the step (b), the reduced-pressure voids or the substantial vacuum voids remaining at the time when the metal foil with an insulating layer and the substrate are joined can be eliminated, and there are very few unfilled portions, or A metal-clad laminate that is substantially absent can be produced.

The metal-clad laminate produced by the steps (a) to (b) is, for example, first and second metal foils 3a and 3a with an insulating resin layer as shown in FIGS. As an example, a form using a metal foil having a larger dimension in the width direction than the base material 4 and an insulating resin layer having a larger dimension in the width direction than the base material 4 may be used. In this embodiment, in the step (a), the first and second metal foils 3a, 3a with insulating resin are respectively formed in the inner region of the width direction dimension of the substrate 4 (region where the substrate 4 exists). It can be joined to the material 4. Moreover, in the outer side area | region (area | region where the base material 4 does not exist) of the width direction dimension of the base material 4, the insulating resin layer surface which each of the 1st and 2nd metal foils 3a and 3a with an insulating resin layer has joined directly. (FIG. 1 (2)). Since these joinings are performed under reduced pressure, even if unfilled portions remain in the inside of the base material 4 or the joining surface between the metal foil 3a with the insulating resin layer and the base material 4, these are reduced in pressure voids. Alternatively, since it can be a substantial vacuum void, it can be easily eliminated by the heat treatment in the step (b). In the step (b), air enters from the peripheral part in the width direction and a new void is formed. It can be prevented from being formed (FIG. 1 (3)).
One or both of the first and second metal foils 3a, 3a with an insulating resin layer may have an insulating resin layer having the same width direction dimension as that of the substrate 4, but the insulating resin can be more easily obtained. The form shown in FIG. 1 is preferable because the base material can be sealed and sealed with a layer and a metal-clad laminate with few voids can be produced.

The metal-clad laminate in FIG. 1 and the like is not particularly limited, but is produced using, for example, 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 epoxy 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.

  The apparatus for producing the metal-clad laminate is an apparatus that can carry out the steps (a) to (b). In the apparatus for producing the metal-clad laminate, the step (a) is performed using a vacuum laminating apparatus. Inside the vacuum laminating apparatus, the metal foil with an insulating resin layer obtained in the step (a) and the base material are installed so as to be continuously supplied. Since the protective film is laminated on the surface of the insulating resin layer, the metal foil with the insulating resin layer is continuously supplied while peeling off the protective film by a winding roll. Moreover, a base material is continuously supplied from the base material of a roll form. The metal foils with an insulating resin layer are overlapped with each other in such a manner that the fiber cloth is sandwiched on the insulating resin layer side, and bonded by a laminate roll. At this time, the insulating resin layer is an uncured or semi-cured material in a substantially solvent-free state, but since it is fluidized by heat melting, it is impregnated into the base material. The joined product after joining can be sent to the next process as it is, or the joining temperature between the metal foil with insulating resin layer and the base material can be adjusted by applying temperature and pressure with a laminate roll. The bonded product after the bonding is transferred between horizontal conveying type hot air dryers and heat-treated at a temperature equal to or higher than the melting temperature of the insulating resin. Thereby, the specific filling part remaining inside the bonded product can be eliminated. The metal-clad laminate after the heat treatment can be formed into a roll-like metal-clad laminate by continuously winding the metal-clad laminate with pinch rolls.

(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 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 film made of the epoxy resin composition of the present invention can be used. In addition, when using the resin film which consists of the said prepreg or the said epoxy resin composition as said insulating layer, the said inner-layer circuit board does not need to consist of a 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 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, 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.

Example 1
(1) Preparation of epoxy resin composition-containing varnish First, silicone rubber fine particles (manufactured by Shin-Etsu Chemical Co., Ltd., KMP-600, average particle size 5 μm) 26.4% by weight, boehmite particles (manufactured by Tesco Corp., AOH) -30, average particle size 1.8 μm) 18.2% by weight, and silica nanoparticles (manufactured by Tokuyama Corp., NSS-5N, average particle size 70 nm) 2.4% by weight ANON: MIBK = 1: 1 (v / V) was dispersed in a solvent to prepare a slurry having a concentration of 65% by weight. To this slurry, epoxy resin (Nippon Kayaku Co., Ltd., NC3000, biphenyl aralkyl type epoxy resin, weight average molecular weight 1300, softening point 57 ° C., epoxy equivalent 276 g / eq) 25.4% by weight, cyanate resin (Lonza Japan) 5. Co., Ltd., PT30, novolac-type cyanate resin, weight average molecular weight 380) 21.2% by weight, and a phenol resin (manufactured by Nippon Kayaku Co., Ltd., GPH-103, biphenyl aralkyl type phenol resin) 4 wt% was dissolved and mixed, and the mixture was stirred using a high-speed stirrer to obtain a varnish having an epoxy resin composition of 70 wt% based on the solid content.

(2) Preparation of prepreg The varnish was impregnated into a glass woven fabric (thickness 94 μm, Nittobo E glass woven fabric, WEA-2116), dried in a heating furnace at 180 ° C. for 2 minutes, and epoxy resin in the prepreg A prepreg having a composition of about 49% by weight based on the solid content was obtained.

(3) Fabrication of metal-clad laminate Four layers of the prepreg were stacked, and 12 μm copper foil (3EC-VLP foil manufactured by Mitsui Kinzoku Mining Co., Ltd.) was 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 having a thickness of 0.130 mm was obtained by pressure forming.

(4) Manufacture of printed wiring board By opening the metal-clad laminate having copper foil on both sides with a drilling machine, conducting conduction between the upper and lower copper foils by electroless plating, and etching the copper foils on both sides L (conductor circuit width (μm)) / S (interconductor circuit width (μm)) = 50/50 in which inner layer circuits are formed on both surfaces.
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 aqueous solution of potassium permanganate at 80 ° C. (Atotech Japan Co., Concentrate Compact CP) for 15 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 printed wiring board was subjected to the ENEPIG process on the connection electrode portion corresponding to the solder bump array of the semiconductor element. 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.

(Example 2)
The components of the slurry were silicone rubber fine particles (manufactured by Shin-Etsu Chemical Co., Ltd., KMP-600, average particle size 5 μm) 32.4% by weight, boehmite particles (manufactured by Tesco Co., Ltd., AOH-30, average particle size 1. 8 μm) 12.2 wt%, and silica nanoparticles (Tokuyama Co., Ltd., NSS-5N, average particle diameter 70 nm), except that the amount was 2.4 wt%.

(Example 3)
Silicone rubber fine particles (manufactured by Shin-Etsu Chemical Co., Ltd., KMP-600, average particle size 5 μm) 26.4% by weight, boehmite particles (manufactured by Tesco Co., Ltd., AOH-30, average particle size 1.8 μm) 18.2 % By weight and 2.4% by weight of silica nanoparticles (manufactured by Tokuyama Co., Ltd., NSS-5N, average particle diameter 70 nm) are dispersed in a solvent of ANON: MIBK = 1: 1 (v / v) to a concentration of 65 weights. % Slurry was prepared. To this slurry, epoxy resin (Nippon Kayaku Co., Ltd., NC3000, biphenyl aralkyl type epoxy resin, weight average molecular weight 1300, softening point 57 ° C., epoxy equivalent 276 g / eq) 18.6% by weight, cyanate resin (Lonza Japan) 30.0% by weight of PT30, novolak-type cyanate resin, weight average molecular weight 380) and 0.02% by weight of zinc octylate (manufactured by Tokyo Chemical Industry Co., Ltd.) as a curing catalyst, Stirring was performed using a high-speed stirring device, and the same procedure as in Example 1 was performed except that the epoxy resin composition obtained a varnish having a solid content of 70% by weight.

Example 4
Silicone rubber fine particles (manufactured by Shin-Etsu Chemical Co., Ltd., KMP-600, average particle size 5 μm) 26.4% by weight, boehmite particles (manufactured by Tesco Co., Ltd., AOH-30, average particle size 1.8 μm) 18.2 % By weight and 2.4% by weight of silica nanoparticles (manufactured by Tokuyama Co., Ltd., NSS-5N, average particle diameter 70 nm) are dispersed in a solvent of ANON: MIBK = 1: 1 (v / v) to a concentration of 65 weights. % Slurry was prepared. To this slurry, epoxy resin (Nippon Kayaku Co., Ltd., NC3000, biphenyl aralkyl type epoxy resin, weight average molecular weight 1300, softening point 57 ° C., epoxy equivalent 276 g / eq) 19.6% by weight, cyanate resin (Lonza Japan) PT30, novolak-type cyanate resin, weight average molecular weight 380, 13.3% by weight, maleimide resin (manufactured by Keisei Kasei Co., Ltd., BMI-70, (3-ethyl-5-methyl-4-maleimidophenyl) ) Methane, bismaleimide resin) 20.1% by weight and 0.02% by weight zinc octylate (manufactured by Tokyo Chemical Industry Co., Ltd.) as a curing catalyst are dissolved and mixed, and stirred using a high-speed stirrer. The same procedure as in Example 1 was conducted except that the resin composition obtained 70% by weight of varnish based on the solid content.

(Example 5)
Silicone rubber fine particles (manufactured by Shin-Etsu Chemical Co., Ltd., KMP-600, average particle size 5 μm) 26.4% by weight, boehmite particles (manufactured by Tesco Co., Ltd., AOH-30, average particle size 1.8 μm) 18.2 % By weight and 2.4% by weight of silica nanoparticles (manufactured by Tokuyama Co., Ltd., NSS-5N, average particle diameter 70 nm) are dispersed in a solvent of ANON: MIBK = 1: 1 (v / v) to a concentration of 65 weights. % Slurry was prepared. To this slurry, epoxy resin (manufactured by Toto Kasei Co., Ltd., ESN-375, naphthalene type epoxy resin, weight average molecular weight 700, softening point 75 ° C., epoxy equivalent 167 g / eq) 25.4% by weight, cyanate resin (Lonza Japan) 5. Co., Ltd., PT30, novolac-type cyanate resin, weight average molecular weight 380) 21.2% by weight, and a phenol resin (manufactured by Nippon Kayaku Co., Ltd., GPH-103, biphenyl aralkyl type phenol resin) 4% by weight was dissolved and mixed, and stirred using a high-speed stirrer to obtain a varnish having an epoxy resin composition based on solid content of 70% by weight.

(Example 6)
Silicone rubber fine particles (manufactured by Shin-Etsu Chemical Co., Ltd., KMP-600, average particle size 5 μm) 26.4% by weight, boehmite particles (manufactured by Tesco Co., Ltd., AOH-30, average particle size 1.8 μm) 18.2 % By weight and 2.4% by weight of silica nanoparticles (manufactured by Tokuyama Co., Ltd., NSS-5N, average particle diameter 70 nm) are dispersed in a solvent of ANON: MIBK = 1: 1 (v / v) to a concentration of 65 weights. % Slurry was prepared. To this slurry, epoxy resin (Nippon Kayaku Co., Ltd., NC3000, biphenyl aralkyl type epoxy resin, weight average molecular weight 1300, softening point 57 ° C., epoxy equivalent 276 g / eq) 25.4% by weight, cyanate resin (Lonza Japan) Made by Co., Ltd., PT30, novolac-type cyanate resin, weight average molecular weight 380) 21.2% by weight and phenolic resin as a curing agent (Maywa Kasei Co., Ltd., MEH-7500, triphenylmethane type phenolic resin, hydroxyl equivalent 97 g / eq) 6.4% by weight was dissolved and mixed and stirred using a high-speed stirrer to obtain a varnish having an epoxy resin composition of 70% by weight based on the solid content. I made it.

(Comparative Example 1)
Silicone rubber fine particles (manufactured by Shin-Etsu Chemical Co., Ltd., KMP-600, average particle size 5 μm) 37.5% by weight, and silica particles (manufactured by Admatechs Co., Ltd., SO-25R, average particle size 0.5 μm) 2 A slurry with a concentration of 65% by weight was prepared by dispersing 0.5% by weight in a solvent of ANON: MIBK = 1: 1 (v / v). To this slurry, epoxy resin (manufactured by Tohto Kasei Co., Ltd., ESN-375, naphthalene type epoxy resin, weight average molecular weight 700, softening point 75 ° C., epoxy equivalent 167 g / eq) 38.0% by weight, phenol as a curing agent The resin (Maywa Kasei Co., Ltd., MEH-7500, triphenylmethane type phenolic resin, hydroxyl group equivalent 97 g / eq) 22.0% by weight is dissolved and mixed and stirred using a high-speed stirring device to obtain an epoxy resin composition The procedure was the same as in Example 1 except that the product obtained a varnish of 70% by weight based on the solid content.

(Comparative Example 2)
The components of the slurry were boehmite particles (Tesco Co., Ltd., AOH-30, average particle size 1.8 μm) 18.2% by weight, silica nanoparticles (Tokuyama Co., Ltd., NSS-5N, average particle size 70 nm) 2 The same procedure as in Example 1 except that the content was 0.4 wt% and the silica particles (manufactured by Admatechs Co., Ltd., SO-25R, average particle size 0.5 μm) were 26.4 wt%.

(Comparative Example 3)
The components of the slurry were silicone rubber fine particles (Shin-Etsu Chemical Co., Ltd., KMP-600, average particle size 5 μm) 18.2% by weight, silica nanoparticles (Tokuyama Co., Ltd., NSS-5N, average particle size 70 nm). The procedure was the same as Example 1 except that the content was 2.4% by weight and 26.4% by weight of silica particles (manufactured by Admatechs Co., Ltd., SO-25R, average particle size 0.5 μm).

(Comparative Example 4)
The components of the slurry were boehmite particles (Tesco Co., Ltd., AOH-30, average particle size 1.8 μm) 20.6% by weight, and silica particles (Admatex Co., Ltd., SO-25R, average particle size 0) 0.5 μm) Same as Example 1 except 26.4% by weight.

(Comparative Example 5)
The components of the slurry were boehmite particles (Tesco Co., Ltd., AOH-30, average particle size 1.8 μm) 44.6% by weight, and silica nanoparticles (Tokuyama Co., Ltd., NSS-5N, average particle size 70 nm) The procedure was the same as Example 1 except that the content was 2.4% by weight.

  The following evaluation was performed on the prepregs, metal-clad laminates, printed wiring boards, semiconductor devices, and the like obtained in the examples and comparative examples. The evaluation items are shown together with the contents. The obtained results are shown in Table 1.

(1) Coefficient of linear expansion The copper foil of the obtained metal-clad laminate is removed by etching, 2 mm × 2 mm is taken as an evaluation sample, and 10 ° C./min using a TMA apparatus (TA Instruments). The temperature was raised to 30 to 150 ° C. under the condition of minutes, and the linear expansion coefficient (CTE) in the thickness direction (Z direction) at 50 to 100 ° C. was measured.

(2) Flame retardancy In the production of the metal-clad laminate, 10 sheets of the prepreg are stacked, 12 μm copper foil is stacked on both sides, and heat-pressed at a pressure of 3 MPa and a temperature of 200 ° C. for 2 hours to obtain a thickness. A 1.02 mm double-sided metal-clad laminate was obtained. The copper foil of the metal-clad laminate obtained above was etched, and a 1.0 mm-thick test piece was measured by the vertical method according to the UL-94 standard.
Nonstandard: One or more of the five test pieces burned out.

(3) Drill wearability Three metal laminates obtained were stacked, and a drill bit (UV L0950) manufactured by Union Tool Co., Ltd. was used with a drill rotation speed of 160 rpm and a feed speed of 3.2 m / min. Drilling 3000 holes of φ150 was performed, the drill blade width before use was taken as 100%, and the remaining ratio of the drill blade width after use was measured.

(4) Prepreg impregnation The cross section of the obtained metal-clad laminate was observed. A scanning electron microscope was used for cross-sectional observation. The impregnation property was evaluated by the area of the observed void in the cross-sectional observation result.
○: Unimpregnated voids were observed at locations where the total area was less than 10%, but this was at a practical level.
Δ: Unimpregnated voids were found at locations where the total area was 10 to 30%, which was not practical.
X: Unimpregnated voids were observed at locations where the total area was 50% or more, which was not practical.

(5) Resistance to desmear The copper foil of the obtained metal-clad laminate is removed by etching, and a single hole is used to form a φ60 μm via hole 500 hole using a carbonic acid laser device (manufactured by Hitachi Via Mechanics Co., Ltd .: LG-2G212). And then immersed in a swelling solution at 70 ° C. (Atotech Japan, Swelling Dip Securigant P) for 5 minutes, and further in an aqueous potassium permanganate solution (Atotech Japan, Concentrate Compact CP) at 80 ° C. for 15 minutes. After soaking, it was neutralized and subjected to a roughening treatment to carry out a desmear treatment, and the amount of film reduction due to the desmear treatment was measured.

(6) Occurrence of streaky irregularities FIG. 2 shows (1) a photograph of the surface of the metal-clad laminate obtained in Example 1, and (2) the surface of the metal-clad laminate obtained in Comparative Example 1. The photograph which image | photographed (3) and the figure explaining the photograph of the surface of the metal foil layer of a metal-clad laminated board are shown. As shown in the photograph, streaky unevenness occurred on the surface of the metal foil layer of the metal-clad laminate of Comparative Example 1, but the surface of the metal foil layer of the metal-clad laminate of Example 1 was The unevenness of was not seen.

(7) ENEPIG characteristic The metal precipitation between the thin wires of the printed wiring board produced by performing the ENEPIG process in the following procedures was confirmed by SEM observation.
[1] Cleaner treatment ACL-007 manufactured by Uemura Kogyo Co., Ltd. was used as a cleaner liquid, and the test piece was immersed in a cleaner liquid at a liquid temperature of 50 ° C. for 5 minutes and then washed with water three times.
[2] Soft Etching Treatment After the cleaner treatment, a mixed solution of sodium persulfate and sulfuric acid was used as a soft etching solution, and the test piece was immersed in a soft etching solution at a liquid temperature of 25 ° C. for 1 minute and then washed with water three times.
[3] Pickling treatment After the soft etching treatment, the test piece was immersed in sulfuric acid having a liquid temperature of 25 ° C. for 1 minute and then washed with water three times.
[4] Pre-dip treatment After the pickling treatment, the test piece was immersed in sulfuric acid at a liquid temperature of 25 ° C. for 1 minute.
[5] Palladium catalyst application step After the pre-dip treatment, KAT-450 manufactured by Uemura Kogyo Co., Ltd. was used as a palladium catalyst application solution in order to apply a palladium catalyst to the terminal portion. The test piece was immersed in the palladium catalyst application solution at a liquid temperature of 25 ° C. for 2 minutes and then washed with water three times.
[6] Electroless Ni plating treatment After the palladium catalyst application step, the test piece was immersed in an electroless Ni plating bath (NPR-4 manufactured by Uemura Kogyo Co., Ltd.) at a liquid temperature of 80 ° C. for 35 minutes, and then washed with water three times. did.
[7] Electroless Pd plating treatment After the electroless Ni plating treatment, the test piece was immersed in an electroless Pd plating bath (TPD-30 manufactured by Uemura Kogyo Co., Ltd.) at a liquid temperature of 50 ° C. for 3 minutes, and then three times. Washed with water.
[8] Electroless Au plating treatment After the electroless Pd plating treatment, the test piece was immersed in an electroless Au plating bath (TWX-40, manufactured by Uemura Kogyo Co., Ltd.) for 30 minutes for 3 times. Washed with water.
○: The ratio of the metal precipitation part is 5% or less in terms of the area in the range of 50 μm × 50 μm between circuits.
X: The ratio of the metal precipitation part is 5% or more in an area in the range of 50 micrometers x 50 micrometers between circuits.

From the evaluation results described in Table 1, the following can be understood.
In Comparative Example 1, due to the fact that the silica nanoparticles and boehmite particles specified in the present invention were not used, the prepreg impregnation property was poor, so that the linear expansion coefficient, flame retardancy, desmear resistance, and ENEPIG characteristics were practical. It was not reached.
In Comparative Example 2, the wear resistance of the drill did not reach a practical level due to the use of silica particles without using the silicone rubber fine particles specified in the present invention.
In Comparative Example 3, the flame retardancy and drill wearability did not reach practical levels because the boehmite particles specified in the present invention were not used.
In Comparative Example 4, due to the fact that the silicone rubber fine particles and silica nanoparticles specified in the present invention were not used, the prepreg impregnation property was poor, so that desmear resistance and ENEPIG characteristics did not reach practical levels.
In Comparative Example 5, the silicone rubber fine particles specified in the present invention were not used, and a large amount of boehmite particles was used, so that the linear expansion coefficient did not reach a practical level.
In Comparative Example 1 and Comparative Example 4, the numerical value of drill wearability is equivalent to the result of the example, but the test piece is in a state containing a very large amount of voids and is objectively compared with the example. It is not possible.
Moreover, in the linear expansion coefficient test of Comparative Example 1 and Comparative Example 4, since the prepreg impregnation property of the test piece was bad, measurement was performed by selecting a portion having a high filling property.
The epoxy resin compositions, prepregs, metal-clad laminates, printed wiring boards, and semiconductor devices obtained in Examples 1 to 6 have a coefficient of linear expansion, flame retardancy, drill wear, prepreg impregnation, and desmear. The tolerance and ENEPIG properties were all good. Therefore, by using the epoxy resin composition containing silicone rubber fine particles characterized by containing epoxy resin, silicone rubber fine particles, boehmite particles, and silica nanoparticles specified in the present invention, a prepreg having excellent performance, It can be seen that a metal-clad laminate, a printed wiring board, and a semiconductor device can be obtained.

3a ... Metal foil with insulating resin layer 4 ... Base material

Claims (13)

  An epoxy resin comprising: an epoxy resin; silicone rubber fine particles having an average particle diameter of 1 μm to 10 μm; boehmite fine particles having an average particle diameter of 0.2 μm to 5 μm; and silica nanoparticles having an average particle diameter of 10 nm to 100 nm. Resin composition.   The epoxy resin composition according to claim 1, wherein the silicone rubber fine particles are core-shell structured particles in which a core portion made of silicone rubber is coated with a silicone resin.   The epoxy resin composition according to claim 1 or 2, wherein an average particle diameter of the silica nanoparticles is 40 nm or more and 100 nm or less.   Furthermore, the epoxy resin composition as described in any one of Claims 1 thru | or 3 which contains cyanate resin.   Furthermore, the epoxy resin composition as described in any one of Claims 1 thru | or 4 which contains a maleimide resin.   The epoxy resin composition according to any one of claims 1 to 5, wherein the epoxy resin is at least one selected from the group consisting of a biphenyl aralkyl type epoxy resin, a naphthalene skeleton-modified epoxy resin, and a cresol novolac type epoxy resin. object.   A prepreg obtained by impregnating a base material with the epoxy resin composition according to any one of claims 1 to 6.   A metal-clad laminate having a metal foil on at least one surface of a resin-impregnated substrate layer obtained by impregnating the epoxy resin composition according to any one of claims 1 to 6 in a substrate.   The metal-clad laminate according to claim 8, which is obtained by superimposing 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 superposed and heating and pressing.   A printed wiring board comprising the metal-clad laminate according to claim 8 or 9 as an inner circuit board.   The printed wiring board which uses the prepreg of Claim 7 for an insulating layer on an inner layer circuit.   The printed wiring board which uses the epoxy resin composition as described in any one of Claims 1 thru | or 6 for an insulating layer on an inner layer circuit.   13. A semiconductor device comprising a semiconductor element mounted on the printed wiring board according to any one of claims 10 to 12.