TW201739828A - Prepreg, prepreg with metal foil, laminate, metal-clad laminate, and printed circuit board having excellent properties of heat resistance, insulation and adhesion - Google Patents

Abstract

The present invention provides a prepreg impregnated with a resin composition having a first phase and a second phase as an island phase in a phase-separated structure with each other, the island phase has an average domain size of 1[mu]m to 10[mu]m. The resin composition contains (C) a filler, wherein the first phase includes (A) an acrylic polymer, and the second phase includes (B) a thermosetting resin.

Description

Prepreg, prepreg with metal foil, laminated board, metal-clad laminate and Printed circuit board

The present invention relates to a prepreg, a metal foil prepreg, a laminate, a metallized laminate, and a printed circuit board.

With the rapid spread of information electronic devices, the miniaturization and thinning of electronic devices are progressing, and there is a growing demand for higher density and higher performance of printed circuit boards mounted therein.

When the thickness of the glass cloth as the base material is made thinner, for example, the thickness of the glass cloth is 30 μm or less, that is, the density of the printed circuit board can be further increased. Therefore, the glass cloth has been commercially available and commercially available. Prepreg. As a result, the density of the printed circuit board is gradually increasing, but it is difficult to ensure sufficient heat resistance of the printed circuit board, insulation reliability, and adhesion between the wiring layer and the insulating layer.

At present, heat resistance, electrical insulation, long-term reliability, and adhesion are required for the wiring board material used in such a high-performance printed circuit board. Further, one of the high-performance printed circuit boards may be, for example, a flexible wiring board material, and the flexible wiring board material is required to have low elasticity in addition to the above characteristics.

Further, in the printed circuit board on which the ceramic component is mounted, there is a problem of reliability of component connection, which occurs due to a difference in thermal expansion coefficient between the ceramic component and the printed circuit board, and external impact. As a solution to this problem, for example, stress relaxation is performed from the printed circuit board side.

As a wiring board material which satisfies such requirements, for example, a resin composition in which a thermosetting resin is blended in a polymer acrylic polymer obtained by copolymerizing a crosslinkable functional group has been proposed. The acrylic polymer is an acrylonitrile-butadiene resin or a carboxyl group-containing acrylonitrile-butadiene resin (see, for example, Patent Documents 1 to 3).

[Previous Technical Literature]

(Patent Literature)

Patent Document 1: Japanese Laid-Open Patent Publication No. Hei 8-283535

Patent Document 2: Japanese Laid-Open Patent Publication No. 2002-134907

Patent Document 3: Japanese Laid-Open Patent Publication No. 2002-371190

A polyacrylate epoxy resin obtained by mixing a polymer acrylic polymer (which is obtained by copolymerizing a crosslinkable functional group) with a thermosetting resin has a structure in which it is connected to each other and regularly dispersed. In the state, the marine phase of the polymer acrylic polymer and the island phase of the epoxy resin form a phase separation structure, and the main component of the marine phase is polymer propylene. An acid polymer, the main component of which is a polyacrylate epoxy resin. A resin composition which forms a phase-separated structure and contains a polymer acrylic polymer and a polyacrylate epoxy resin, and it is desirable to have both of the polymer acrylic polymer and the epoxy resin, but it is not sufficient Excellent character.

The polymer acrylic polymer obtained by copolymerizing a crosslinkable functional group is characterized by low elasticity, high elongation, and easy addition of a functional group. On the other hand, an epoxy resin which is a thermosetting resin is characterized by high insulation reliability, high heat resistance, and high glass transition temperature (Tg).

When a polymer acrylic polymer (which is obtained by copolymerizing a crosslinkable functional group) and an epoxy resin (thermosetting resin) are uniformly mixed with each other and have a structure which is close to compatibility in appearance, The epoxy resin is dispersed in the nanophase of the polymer acrylic polymer in a nanometer size, so that it is biased toward the characteristics of the polymer acrylic polymer, and the high insulation reliability of the epoxy resin cannot be sufficiently exhibited. High heat resistance and high Tg. Further, the surface area of the polymer acrylic polymer which is relatively weak in adhesion to the metal foil becomes large, and the adhesion strength between the insulating layer and the metal foil is lowered.

On the other hand, in the phase-separated structure, when the characteristics of the island phase are high, the characteristics of the island phase of the epoxy resin are biased, and although the adhesion strength with the metal foil is increased, the polymer cannot be sufficiently exhibited. The low flexibility and softness of the acrylic polymer.

Further, at present, attempts have been made to introduce a filler component for the purpose of imparting strength and heat resistance. However, aggregation and deposition of components, high elasticity of a resin composition, and heat resistance are lowered, and it is difficult to achieve balance. In other words, it is difficult to form an insulating layer which satisfies the insulation reliability, high heat resistance, flexibility, low elasticity, and the like.

An object of the present invention is to provide a prepreg, a prepreg with a metal foil, a laminate, a metallized laminate, and a printed circuit board, the low elasticity, insulation reliability, heat resistance and metal foil of the prepreg Excellent adhesion between.

The present invention relates to the following matters.

(1) A prepreg impregnated with a resin composition, wherein a first phase of the resin composition forms a phase separation structure with a second phase as an island phase, and an average region size of the island phase is 1 μm to 10 μm, and The resin composition contains (C) a filler, wherein the first phase contains (A) an acrylic polymer, and the second phase contains (B) a thermosetting resin.

(2) The prepreg according to (1), wherein the total amount of the (A) acrylic polymer and the (B) thermosetting resin is 100 parts by mass, the (A) acrylic acid The blending amount of the polymer is 10 to 70 parts by mass.

(3) The prepreg according to (1) or (2), wherein the resin composition contains (C-1) a coupling-treated filler as the (C) filler.

The prepreg according to any one of (1) to (3), wherein the resin composition contains (C-2) a non-coupling filler as the (C) filler.

The prepreg according to any one of (1) to (4), wherein the (B) thermosetting resin comprises (B-1) an epoxy resin and (B-2) a phenol resin.

(6) The prepreg according to (5), wherein the (B-1) epoxy resin contains an epoxy resin having two or more epoxy groups in one molecule.

(7) The prepreg according to (5) or (6), wherein the (B-1) epoxy resin has a weight average molecular weight of 200 to 1,000.

The prepreg according to any one of (5) to (7), wherein the epoxy resin of the (B-1) epoxy resin has an epoxy equivalent of from 150 to 500.

The prepreg according to any one of (1) to (8), wherein the (A) acrylic polymer has a weight average molecular weight of 10,000 to 1,500,000.

The prepreg according to any one of (5), wherein the (B-2) phenol resin contains a phenol resin having two or more hydroxyl groups in one molecule.

The prepreg according to any one of (1) to (10) which contains cerium oxide as the (C) filler.

The prepreg according to any one of (1) to (11), wherein the (C-2) filler has a volume average particle diameter of 1.0 μm to 3.5 μm.

(13) A prepreg provided with a metal foil, which is obtained by laminating a prepreg according to any one of (1) to (12) and a metal foil.

(14) A laminate comprising the plurality of prepregs according to any one of (1) to (12).

(15) A metal-clad laminate comprising the laminate of (14) further comprising a metal foil.

(16) A printed circuit board obtained by further comprising a circuit board according to (14).

According to the present invention, it is possible to provide a prepreg, a metal foil with a resin, and a printed circuit board which is excellent in low elasticity, insulation reliability, heat resistance, and adhesion to a metal foil.

Fig. 1 is a model diagram showing a case where the phase separation structure of the resin composition is a continuous spherical structure.

Fig. 2 is a model diagram showing a case where the phase separation structure of the resin composition is an island structure.

Fig. 3 is a model diagram showing a case where the phase separation structure of the resin composition is a composite dispersed phase structure.

Fig. 4 is a model diagram showing a case where the phase separation structure of the resin composition is a co-continuous phase structure.

Fig. 5 is an electron micrograph showing a cross-sectional structure of an example of a resin composition having a sea-island structure obtained in the present invention.

Fig. 6 is an electron micrograph showing a cross-sectional structure of an example of a resin composition having a composite dispersed phase structure obtained in the present invention.

[Preferred form of implementing the invention]

Hereinafter, an embodiment of the present invention will be described in detail, but the present invention is not limited to the following embodiments.

(prepreg)

A prepreg according to an embodiment of the present invention is characterized in that a resin composition is impregnated, and a first phase of the resin composition forms a phase separation structure with a second phase as an island phase, and an average area size of the island phase is 1 μm to 10 μm, and the resin composition contains (C) a filler (hereinafter referred to as "(C) component"), and the first phase contains (A) an acrylic polymer (hereinafter referred to as "(A) component"), The second phase contains (B) a thermosetting resin (hereinafter referred to as "component (B)").

The reason why the component (A) does not form an island phase but forms a sea phase is considered to be as follows: in the component (A) having a large molecular weight and a large amount of intertwining, when the component (B) is phase-separated, (A) In order to become an island phase, the components must be entangled with each other or cut into a networked eye, and it is not easy to become an island phase.

[Resin composition] [Acrylic polymer: (A) component]

The component (A) is an acrylic polymer, and is usually a copolymer of a (meth)acrylic acid alkyl ester as a monomer. As the copolymer, an acrylic polymer obtained by copolymerizing a crosslinkable functional group is preferred. Such copolymers are generally produced by copolymerizing an alkyl (meth)acrylate with a comonomer having a crosslinkable functional group. The comonomer having a crosslinkable functional group is not particularly limited as long as it is a compound copolymerizable with an alkyl (meth)acrylate; and as the crosslinkable functional group, it is preferred to have an epoxy group to have A glycidyl group is preferred. As the comonomer having a crosslinkable functional group, glycidyl (meth)acrylate is preferred. In the alkyl (meth)acrylate, the alkyl group is preferably an alkyl group having 1 to 20 carbon atoms, and the alkyl group may have a substituent. Examples of the substituent of the alkyl group include an alicyclic group, a glycidyl group, an alkyl group having a hydroxyl group having 1 to 6 carbon atoms, and a nitrogen-containing cyclic group.

Examples of the (meth)acrylic acid alkyl ester include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, isobutyl acrylate, and ethylene glycol. Methyl ether acrylate, cyclohexyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, isobornyl acrylate, acrylamide, isodecyl acrylate, octadecyl acrylate, lauryl acrylate, acrylic acid Allyl ester, N-vinylpyrrolidone acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, hexyl methacrylate, 2-ethyl methacrylate Hexyl ester, isobutyl methacrylate, ethylene glycol monomethyl ether methacrylate, cyclohexyl methacrylate, A 2-hydroxyethyl acrylate, 2-hydroxypropyl methacrylate, isobornyl methacrylate, methacrylamide, isodecyl methacrylate, octadecyl methacrylate, lauryl methacrylate , allyl methacrylate, N-vinylpyrrolidone methacrylate, acrylonitrile, and the like.

When the component (A) has an epoxy group, the epoxy group value is preferably 2 equivalents/kg to 18 equivalents/kg, more preferably 2 equivalents/kg to 8 equivalents/kg. When the epoxy group value is 2 equivalent/kg or more, the glass transition temperature of the cured product can be suppressed from being lowered, and the heat resistance of the substrate can be sufficiently ensured. If the epoxy group value is 18 equivalent/kg or less, the storage elastic modulus is not It will be too large, and there is a tendency to maintain the dimensional stability of the substrate. When the glycidyl (meth)acrylate is copolymerized with another monomer copolymerizable therewith, the epoxy group value of the component (A) can be adjusted by appropriately adjusting the copolymerization ratio. In general, the epoxy group value of 2 equivalents/kg to 18 equivalents/kg can be obtained by setting the ratio of the other monomers to 5 parts by mass to 15 parts by mass based on 100 parts by mass of glycidyl (meth)acrylate. A polymer acrylic polymer.

For example, "HTR-860" (manufactured by Nagase ChemteX Co., Ltd., trade name, epoxy group value 3.1) and "KH-CT-865" ("KH-CT-865") can be obtained as a commercially available product having the epoxy group (A). Manufactured by Hitachi Chemical Co., Ltd., trade name, epoxy group value 3.0), "HAN5-M90S" (manufactured by Roots Industrial Co., Ltd., trade name, epoxy group value 2.2). From the viewpoint of increasing the elongation and improving the low elasticity, the weight average molecular weight of the component (A) is preferably 10,000 to 1,500,000, more preferably 50,000 to 1,500,000. 300,000 to 1,500,000 is better, with 300,000 to 1,100,000. When the weight average molecular weight of the component (A) is 1,500,000 or less, it tends to be easily dissolved in a solvent and is easily handled. In addition, when the weight average molecular weight of the component (A) is 1,500,000 or less, there is a tendency that a phase separation structure having a large co-continuous phase is not easily formed after the component (B) is blended, and high insulation reliability is easily exhibited. High heat resistance and high adhesion to metal foil. When the weight average molecular weight of the component (A) is 10,000 or more, the low elasticity of the component (A) tends to be easily exhibited.

The component (A) may be a combination of two or more kinds having different weight average molecular weights.

The above weight average molecular weight is a value measured by gel permeation chromatography (GPC) analysis, and means a value converted in terms of standard polystyrene. GPC analysis can be carried out using tetrahydrofuran (THF) as a solution.

Further, in order to obtain sufficient characteristics in an accelerated test of insulation reliability such as a pressure cooker bias test (PCBT), the component (A) preferably has an alkali metal ion concentration of 500 ppm or less, preferably 200 ppm or less, and 100 ppm or less. good.

In general, the component (A) is obtained by radically polymerizing a monomer using a radical polymerization initiator which generates a radical. Examples of the radical polymerization initiator include azobisisobutyronitrile (AIBN), butyl perbenzoate, benzylidene peroxide, lauryl peroxide, potassium persulfate, and the like. Sulfate, cumene hydroxide, tertiary butyl hydrogen Peroxide, dicumyl peroxide, bis(tributyl) peroxide, 2,2'-azobis-2,4-dimethylvaleronitrile, tert-butyl peroxybutyrate , tributyl methacrylate, hydrogen peroxide / ferrous salt, persulphate / sodium bisulfite, cumene hydroperoxide / ferrous salt, benzhydryl peroxide / dimethyl Aniline and the like. The radical polymerization initiator may be used singly or in combination of two or more.

In the resin composition of the embodiment of the present invention, when the total amount of the component (A) and the component (B) is 100 parts by mass, the amount of the component (A) is preferably 10 to 70 parts by mass. When the amount of the component (A) is less than 10 parts by mass, there is a tendency that the excellent characteristic of the component (A), that is, the low elasticity, is not effectively exhibited. In addition, when the amount of the component (A) is more than 70 parts by mass, the adhesive strength between the metal foil and the metal foil may not be obtained, and the flame retardancy tends to be lowered.

In addition, in the total amount of 100 parts by mass of the component (A) and the component (B), the amount of the component (A) is preferably 15 parts by mass or more, and preferably 20 parts by mass. More preferably, it is more preferably 30 parts by mass or more.

In addition, the blending amount of the component (A) is preferably 60 parts by mass or less, based on 100 parts by mass of the total amount of the component (A) and the component (B), from the viewpoint of obtaining a good adhesion strength to the metal foil. Preferably, it is preferably 50 parts by mass or less, more preferably 40 parts by mass or less.

[thermosetting resin: (B) component]

As the component (B) used in the present invention, a compound which has a phase-separated structure after being combined with the component (A) is suitably selected. As (B) The component is not particularly limited, and examples thereof include an epoxy resin, a cyanate resin, a bismaleimide resin, an addition polymer of a bismaleimide resin and a diamine, a phenol resin, and a resol. A varnish (resol) resin, an isocyanate resin, a triallyl isocyanurate resin, a triallyl cyanurate resin, a vinyl group-containing polyolefin compound, and the like. Among these, in consideration of the balance of properties such as heat resistance and insulation, an epoxy resin or a cyanate resin is preferred.

(B) Component If the resin composition of the embodiment of the present invention is cured, a resin composite having a phase-separated structure can be formed, and the component (B) is preferably a resin composition comprising: (B-1) An epoxy resin having two or more epoxy groups (hereinafter referred to as "(B-1)" component) in one molecule; and (B-2) a phenol resin having two or more hydroxyl groups in one molecule (hereinafter referred to as "(B-2)" component).

<Epoxy resin having two or more epoxy groups in one molecule: (B-1) component>

The component (B) is preferably a component (B-1).

The weight average molecular weight of the component (B-1) is preferably from 200 to 1,000, more preferably from 300 to 900. When the weight average molecular weight is 200 or more, a phase separation structure tends to be formed with the component (A), and when the weight average molecular weight is 1,000 or less, a phase separation structure having a second phase having a small region tends to be formed. And there is a tendency to appear low elasticity.

The epoxy equivalent of the component (B-1) is preferably 150 to 500, more preferably 150 to 450, and most preferably 150 to 300. If the ring of epoxy When the oxygen equivalent is within the above range, the average region size of the second phase tends not to be too large.

As the component (B-1), a conventional one can be used, and examples thereof include a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a bisphenol S type epoxy resin, a biphenyl type epoxy resin, and a phenol. Novolak type epoxy resin, cresol novolac type epoxy resin, bisphenol A novolac type epoxy resin, phosphorus-containing epoxy resin, epoxy resin containing naphthalene skeleton, epoxy resin containing an aralkyl group skeleton , phenol biphenyl aralkyl type epoxy resin, phenol salicylaldehyde novolak type epoxy resin, phenol salicylaldehyde novolak type epoxy resin substituted by lower alkyl group, epoxy resin containing dicyclopentadiene skeleton, A polyfunctional glycidylamine type epoxy resin, a polyfunctional alicyclic epoxy resin, a tetrabromobisphenol A type epoxy resin, or the like. One or two or more of these can be used.

The commercially available product of the component (B-1) is, for example, a phenol novolac type epoxy resin "N770" (manufactured by DIC Corporation), and a tetrabromobisphenol A type epoxy resin "EPICLON 153". (made by DIC Co., Ltd., trade name), biphenyl aralkyl type epoxy resin "NC-3000H" (manufactured by Nippon Kayaku Co., Ltd., trade name), bisphenol A type epoxy resin "Epikote 1001" ( "Mitsubishi Chemical Co., Ltd., trade name", phosphorus-containing epoxy resin "ZX-1548" (manufactured by Tohto Kasei Co., Ltd., trade name), cresol novolac type epoxy resin "EPICLON N-660" (DIC shares) Co., Ltd., product name) and so on.

<Phenol resin having two or more hydroxyl groups in one molecule: (B-2) component>

From the viewpoint of ensuring the adhesion strength to the metal foil, the component (B) is preferably a component (B-2).

As the component (B-2), a conventional one can be used, and examples thereof include an aralkyl type phenol resin, a dicyclopentadiene type phenol resin, a salicyl type phenol resin, and a benzaldehyde type phenol resin and an aralkyl type. A copolymer resin obtained from a phenol resin, a novolac type phenol resin, or the like. One or two or more of these can be used.

From the viewpoint of low water absorption, as the component (B-2), a polyhydric phenol such as a phenol novolak is preferably used.

The commercially available product of the component (B-2) may, for example, be a cresol novolac type resin "KA-1165" (manufactured by DIC Corporation, trade name) or a biphenol novolak type resin "MEH-7851". (Mingwa Chemical Co., Ltd., product name), etc.

The blending ratio of the component (B-2) is usually determined by increasing the glass transition temperature. For example, when a phenol novolak type resin is used as the component (B-2), it is preferably 0.5 to 1.5 equivalents based on the epoxy group of the component (B-1). The epoxy group of the component (B-1) is from 0.5 equivalent to 1.5 equivalents, that is, the adhesion to the outer layer copper can be prevented from being lowered, and the glass transition temperature (Tg) and the insulating property can be prevented from being lowered.

<(B) component hardener>

The resin composition of the present invention may contain a curing agent of the component (B). As the curing agent of the component (B), a conventional one can be used. For example, an amine-based curing agent such as dicyandiamide, diaminodiphenylmethane or diaminodiphenylphosphonium; an acid anhydride hardener such as pyromellitic anhydride, trimellitic anhydride or benzophenonetetracarboxylic acid; Or a mixture of these, etc.

In the present invention, the combination of the component (B) and the curing agent can be considered in various combinations depending on the component (A) to be used, the curing conditions, the curing agent, and the curing catalyst.

In general, the phase structure of the cured resin is determined by a competitive reaction between the phase separation rate and the crosslinking reaction rate. When an epoxy resin is exemplified, the catalyst species and the skeleton structure are controlled, and the epoxy resins having different characteristics are mixed and hardened, that is, a phase separation structure having an average region size of about 1 μm to 10 μm can be formed. That is, the island structure.

[Filler: (C) ingredients]

The resin composition of the embodiment of the present invention preferably contains one or more kinds of cerium oxide as the component (C). In addition, the resin composition of the embodiment of the present invention preferably contains one or more (C-1) coupling-treated fillers (hereinafter referred to as "(C-1) components") as the component (C). Further, the tree composition of the embodiment of the present invention preferably contains (C-2) a non-coupling filler (hereinafter referred to as "(C-2) component") as the component (C).

The component (C) used in the present invention preferably contains one or more (C-1) components and one or more (C-2) components. Use implemented coupling The compound to be treated and the component (C-2) which has not been subjected to the coupling treatment can control the dispersibility of the filler in the resin composition, and can sufficiently exhibit the characteristics of both the component (A) and the component (B).

The average particle diameter of the component (C-1) is preferably 0.1 μm to 1.5 μm, more preferably 0.2 μm to 1.2 μm, still more preferably 0.3 μm to 1.0 μm. When the average particle diameter of the component (C-1) is 0.1 μm or more, the filler tends to be easily dispersed after varnishing, and aggregation tends to occur, and the average particle diameter of the component (C-1) is 1.5 μm or less. There is a tendency that the component (C) does not easily deposit when the varnish is applied.

The average particle diameter of the component (C-2) is preferably 1.0 μm to 3.5 μm, more preferably 1.2 μm to 3.2 μm, still more preferably 1.4 μm to 3.0 μm. When the average particle diameter of the component (C-2) is 1.0 μm or more, the fillers tend to be easily dispersed and are less likely to aggregate. When the average particle diameter of the component (C-2) is 3.5 μm or less, it is progressing. When the varnish is formed, the component (C) tends not to be deposited.

Here, the average particle diameter refers to a particle diameter corresponding to a volume of 50% when the cumulative volume distribution curve obtained by the particle diameter is obtained by setting the total volume of the particles to 100%, and can be used by using a The measurement is performed by a particle size distribution measuring apparatus or the like which emits a diffraction scattering method.

As the component (C) used in the present invention, a conventional one can be used. In order to reduce the coefficient of thermal expansion and to ensure flame retardancy, it is preferred to add an inorganic filler. As the inorganic filler, for example, cerium oxide, aluminum oxide, titanium oxide, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium citrate, calcium oxide, magnesium oxide, aluminum nitride, boric acid Aluminum whiskers, boron nitride, tantalum carbide, and the like. Among them, yttrium oxide is more preferable because of a low dielectric constant and a low coefficient of linear expansion.

As the cerium oxide used in the present invention, various cerium oxides can be used: pulverized cerium oxide obtained by pulverizing various synthetic cerium oxide or vermiculite synthesized by a wet method or a dry method; The molten cerium oxide or the like obtained by temporarily melting the various synthetic cerium oxide or vermiculite synthesized by the dry method.

In the present invention, the blending ratio of the component (C) is preferably 5% by mass to 40% by mass of the solid content of all the resin compositions, and preferably 10% by mass to 35% by mass of the solid content of all the resin compositions. It is more preferably 15% by mass to 30% by mass based on the solid content of all the resin compositions. The compounding ratio of the component (C) is 40% by mass or less, and the insulating resin is not brittle, and a polymer acrylic polymer obtained by copolymerizing a crosslinkable functional group of the component (A) can be obtained. It has a tendency to be low in elasticity and softness. In addition, the blending ratio of the component (C) is 5% by mass or more, and the coefficient of linear expansion is lowered to obtain sufficient heat resistance.

In the present specification, the term "solid content" means a non-volatile component remaining after removing a volatile substance such as a solvent, and is a component which remains after being volatilized after drying the resin composition, and is also included in The room temperature is a liquid, maltose or waxy component. Here, in the present specification, the room temperature means 25 ° C.

<hardening accelerator>

The resin composition may contain a hardening accelerator. The curing accelerator is not particularly limited, and an amine or an imidazole is preferred. The amines may, for example, be dicyandiamide, diaminodiphenylethane or formylurea. Examples of the imidazoles include 2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, and 1-cyanoethyl-2-phenylimidazole. 1-cyanoethyl-2-imidazolium trimellitate, benzimidazole, and the like.

The amount of the curing accelerator can be determined in accordance with the total amount of the oxirane ring in the resin composition, and is generally 0.01 parts by mass in 100 parts by mass of the resin solid content of the resin composition. 10 parts by mass is more preferably 0.02 parts by mass to 9.0 parts by mass, and more preferably 0.03 parts by mass to 8.0 parts by mass.

<Other ingredients>

The resin composition of the present invention may contain, for example, a crosslinking agent, a flame retardant, a flow regulator, conductive particles, a coupling agent, a pigment, a coating agent, an antifoaming agent, an ion trap, and an antioxidant, etc., as needed. And can use conventional materials.

<solvent>

When a prepreg or the like is produced by using the resin composition of the present invention, a varnish which is a state in which a component of the resin composition of the present invention is dissolved or dispersed in an organic solvent can be produced.

When the resin composition of the present invention is used as a varnish, the organic solvent to be used is not particularly limited, and a ketone type, an aromatic hydrocarbon type, an ester type, a guanamine type, an alcohol type or the like can be used.

Examples of the ketone solvent include acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone.

Examples of the aromatic hydrocarbon solvent include toluene and xylene.

The ester solvent may, for example, be methoxyethyl acetate, ethoxyethyl acetate, butoxyethyl acetate or ethyl acetate.

Examples of the guanamine-based solvent include N-methylpyrrolidone, formamide, N-methylformamide, and N,N-dimethylacetamide.

Examples of the alcohol solvent include methanol, ethanol, ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol, triethylene glycol monomethyl ether, and triethylene glycol. Alcohol monoethyl ether, triethylene glycol, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, propylene glycol monopropyl ether, dipropylene glycol monopropyl ether and the like.

These organic solvents may be used alone or in combination of two or more.

[phase separation structure]

In the present invention, the phase separation structure means: an island structure, a continuous spherical structure, a composite dispersed phase structure, a co-continuous phase structure, and an average region size of the island phase is 1 μm to 10 μm, preferably 1 μm to 9 μm. 2 μm to 8 μm is preferred.

When the average area size of the island phase is less than 1 μm, it is difficult to exhibit good insulation reliability and high heat resistance of the thermosetting resin (B). Further, the surface area of the acrylic polymer having a relatively weak adhesive strength with the metal foil tends to be large, and a good adhesive strength between the insulating layer and the metal foil is not obtained.

Further, when the average area size of the island phase exceeds 10 μm, it tends to be difficult to exhibit the low elasticity of the component (A).

Here, the average area size of the island phase is obtained by smoothing a cross section of the resin composition after thermosetting using a microtome, and then using an electron microscope to obtain 70 or more cross-sectional structures obtained. The island phase measures the maximum width and the minimum width, respectively, and calculates the average value.

Further, regarding the sea-island structure, the continuous spherical structure, the composite dispersed phase structure, and the co-continuous phase structure (also referred to as a continuous phase structure) as a phase separation structure, for example, "Polymer Alloy", page 325 (1993), Tokyo As described in detail in the chemistry, the continuous spherical structure has been described in detail, for example, in Keizo Yamanaka and Takashi Iniue, POLYMER, Vol. 30, pp. 662 (1989).

Fig. 1 to Fig. 4 show model diagrams showing a continuous spherical structure, a sea-island structure, a composite dispersed phase structure, and a co-continuous phase structure, respectively.

Such a fine phase separation structure is obtained by controlling the catalyst species of the resin composition, the hardening conditions such as the reaction temperature, or the compatibility between the components of the resin composition. In order to facilitate phase separation, it can be achieved by, for example, using an epoxy resin substituted with an alkyl group to reduce compatibility with a polymer acrylic polymer, or when it is the same composition system. At the same time, the hardening temperature is increased, or the rate of hardening is lowered by selecting a catalytic species.

In the fifth drawing, an electron micrograph is shown, which is a cross-sectional structure showing an example of a resin composition having a sea-island structure obtained as described above. As shown in the figure, the resin composition has a sea-island structure composed of an acrylic polymer phase and an epoxy-rich phase. Further, the average phase area of the island phase composed of the epoxy resin is about 1 μm to 10 μm. By having such a phase separation structure, it is possible to combine the excellent characteristics of both of the following: the low elasticity of the acrylic polymer; and the high insulation reliability, high heat resistance, and metal of the thermosetting resin. High adhesion between foils.

As described above, the resin composition used in the present invention forms a sea-island structure or a continuous spherical structure when the component (C) is not added thereto, but by adding the (C) component, in addition to the sea-island structure or the continuous spherical structure. In addition, a resin insulating layer having a fine co-continuous phase structure or a composite dispersed phase structure can also be formed. Fig. 6 shows an electron micrograph, which is a cross-sectional structure showing an example of an insulating resin having a composite dispersed phase structure.

[Manufacturing method of prepreg]

The prepreg of the present invention can be produced by impregnating a varnish of the above resin composition with a base material and drying it in a range of, for example, 80 ° C to 180 ° C.

The base material is not particularly limited as long as it is used for producing a metal-clad laminate or a printed circuit board, and a fibrous base material such as a woven fabric or a nonwoven fabric is usually used. Examples of the material of the fiber base material include glass, alumina, asbestos, boron, yttrium aluminum glass, and bismuth glass. Inorganic fibers such as Tyranno, tantalum carbide, tantalum nitride, zirconia; organic fibers such as linaloamine, polyetheretherketone, polyetherimine, polyether oxime, carbon, cellulose; and the like. Among these, a glass cloth is preferable, and a glass cloth having a thickness of 100 μm or less is preferable, and a glass cloth having a thickness of 50 μm or less is particularly preferable. When the thickness of the glass cloth is 50 μm or less, a printed circuit board which can be arbitrarily bent can be obtained, and the dimensional change due to temperature, moisture absorption, and the like in the process is small, which is preferable.

It is preferred that the organic solvent used in the varnish of the obtained prepreg is volatilized by 80% by mass or more. When the organic solvent used in the varnish has been volatilized by 80% by mass or more, the production method, drying conditions, and the like are not limited. When drying, the temperature is, for example, 80 ° C to 180 ° C, and the time is appropriately set in consideration of the gelation time of the varnish. . Further, it is preferable to set the impregnation amount of the varnish to 30% by mass to 80% by mass based on the total amount of the varnish solid content and the base material.

(prepreg with metal foil)

In the prepreg with metal foil of the present invention, it is preferred that the prepreg and the metal foil are laminated.

The metal foil-attached prepreg of the present invention can be produced by, for example, superposing a metal foil on one or both sides of the prepreg of the present invention, and is usually 130 ° C to 250 ° C, preferably The temperature is in the range of 150 ° C to 230 ° C, and is heated and pressurized at a pressure of usually 0.5 MPa to 20 MPa, preferably 1 MPa to 8 MPa. The method of heating and pressurizing is not particularly limited, and for example, multi-stage pressurization, multi-stage vacuum pressurization, continuous molding, autoclave molding machine, or the like can be used.

Further, when the metal foil-attached prepreg of the present invention is produced, the metal foil to be used is not particularly limited, and for example, a copper foil or an aluminum foil is generally used. The thickness of the metal foil is not particularly limited, and a metal foil of 1 μm to 200 μm can be used. Others can also be used, for example, nickel, nickel-phosphorus, nickel-tin alloy, nickel-iron alloy, lead, lead-tin alloy or the like as an intermediate layer, and a copper layer of 0.5 μm to 15 μm and a thickness of 10 μm to 300 μm are provided on both sides thereof. A composite foil of a three-layer structure made of a copper layer; or a composite foil of a two-layer structure in which aluminum and a copper foil are composited.

(Laminated board)

The laminate of the present invention preferably has a plurality of the above prepregs.

The laminated board of the present invention is obtained, for example, by heating and pressurizing the prepreg layer of the present invention. The method of heating and pressurizing is not particularly limited, and for example, multistage pressurization, multistage vacuum pressurization, continuous molding, autoclave molding machine, or the like can be used.

(metal clad laminate)

In the metal-clad laminate according to the present invention, it is preferable that the laminate further has a metal foil.

The metal-clad laminate of the present invention can be produced by, for example, superposing a metal foil on one or both sides of the laminate of the present invention, and is usually 130 ° C to 250 ° C, preferably 150 ° C to 230 The temperature in the range of °C is heated and pressurized at a pressure in the range of usually 0.5 MPa to 20 MPa, preferably 1 MPa to 8 MPa. The method of heating and pressurizing is not particularly limited, and for example, multi-stage pressurization, multi-stage vacuum pressurization, continuous molding, autoclave molding machine, or the like can be used.

Further, in the production of the metal-clad laminate of the present invention, the metal foil to be used is not particularly limited, and for example, a copper foil or an aluminum foil is generally used. The thickness of the metal foil is not particularly limited, and a metal foil of 1 μm to 200 μm can be used. Others can also be used, for example, nickel, nickel-phosphorus, nickel-tin alloy, nickel-iron alloy, lead, lead-tin alloy or the like as an intermediate layer, and a copper layer of 0.5 μm to 15 μm and a thickness of 10 μm to 300 μm are provided on both sides thereof. A composite foil of a three-layer structure made of a copper layer; or a composite foil of a two-layer structure in which aluminum and a copper foil are composited.

(printed circuit board)

In the printed circuit board of the present invention, it is preferable that the laminated board further has a circuit. The circuit is preferably formed by circuit processing the laminated board of the present invention.

The method for producing a printed circuit board of the present invention is not particularly limited, and can be produced by performing a circuit on a metal foil of a laminate (metal-clad laminate) of the present invention in which a metal foil is provided on one or both sides. (line) processing.

[Examples]

Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited by the examples. In addition, the numerical value in the following example means mass% unless it demonstrates especially.

[Example 1 to Example 13]

The components (A), (B-1), (B-2), (C-1), and (C-2) are blended in the amounts shown in Table 1, and these components are blended. After dissolving in methyl ethyl ketone, the component (D) and the coupling agent were blended in accordance with Table 1, and a resin composition varnish having a nonvolatile content of 40% was obtained.

[Comparative Example 1 to Comparative Example 10]

The components (A), (B-1), (B-2), (C-1), and (C-2) are blended in the amounts shown in Table 2, and the components are dissolved. After the methyl ethyl ketone was added, the component (D) was formulated in accordance with Table 2 to obtain a resin composition varnish having a nonvolatile content of 40%.

[Prepreg, metal foil with resin, metal-clad laminate] (1) Production of prepreg

The varnishes obtained in Examples 1 to 13 and Comparative Examples 1 to 10 were immersed in a glass cloth "1037" (manufactured by Asahi-Schwebel Co., Ltd., trade name) having a thickness of 0.028 mm, and then heated at 140 ° C for 10 minutes. And dried to obtain a prepreg.

(2) Production of copper foil with resin

The varnish prepared in Examples 1 to 13 and Comparative Examples 1 to 10 was coated with an electrolytic copper foil "YGP-18" (manufactured by Nippon Electrolysis Co., Ltd.) having a thickness of 18 μm using a coater. It was molded and dried by hot air at 140 ° C for about 6 minutes to obtain a resin-coated copper foil having a coating thickness of 50 μm.

(3) Fabrication of metal-clad laminates (copper-clad laminates)

After the prepreg prepared in (1) was overlaid with four sheets, an electrolytic copper foil "YGP-18" (manufactured by Nippon Denshoku Co., Ltd., product name) having a thickness of 18 μm was used to adhere the adhesive surface to the prepreg. Overlapped by the overlapping Both sides of the prepreg were fabricated, and a double-sided copper-clad laminate was produced under vacuum pressure of 200 ° C for 60 minutes and 4 MPa. Further, the copper foil with the resin was superposed so that the resin faces faced each other, and a double-sided copper clad laminate was produced under vacuum pressure of 200 ° C for 60 minutes and 4 MPa.

[Evaluation method of varnish, prepreg and metal-clad laminate] (1) varnish properties

The varnish property was evaluated by placing the obtained varnish in a transparent container and observing the appearance after 24 hours by the naked eye, and observing the separation and deposit of the varnish component. If the varnish is uniform in color, it is judged that it is not separated. Further, when it was impossible to confirm with the naked eye that there was deposit accumulation at the bottom of the container, it was judged that there was no deposit. The results are shown in Tables 1 and 2.

(2) Viscosity of prepreg

The evaluation of the viscosity of the prepreg is carried out by processing the prepared prepreg into a size of 250 mm × 250 mm and overlapping 100 pieces, and then putting them into a bag which can be sealed in a sealed manner, and then inputting a temperature of 25 ° C and a humidity of 70%. In a constant temperature and humidity environment, it is observed whether or not the prepregs are in close contact with each other. After 48 hours, the prepreg disposed at the bottom and the prepreg adjacent thereto were peeled off, and when each prepreg was maintained on the surface before the input, no adhesion occurred and it was judged to be viscous. problem. The results are shown in Tables 1 and 2.

(3) Appearance of prepreg (with or without agglomerates)

The appearance of the prepreg was evaluated using a 20x magnifying glass to observe the formation of agglomerates. The results are shown in Tables 1 and 2.

(4) Storage elastic modulus

The evaluation of the storage elastic modulus is performed by etching the entire surface of the copper clad laminate obtained by laminating the resin-coated copper foil so that the resin faces face each other, and the laminated plate is cut into After the width was 5 mm × the length of 30 mm, the storage elastic modulus was calculated using a dynamic viscoelasticity measuring device (manufactured by UBM Co., Ltd.). When the storage elastic modulus at 25 ° C is 2.0 × 10 ⁹ Pa or less, it is judged that the stress relaxation effect can be exhibited. The results are shown in Tables 1 and 2.

(5) tensile elongation

The evaluation of the tensile elongation is performed by etching the entire surface of the copper clad laminate obtained by laminating the resin-coated copper foil so that the resin faces face each other, and the laminated plate is cut into After the width was 10 mm and the length was 100 mm, the tensile strength was calculated using an autograph (manufactured by Shimadzu Corporation). When the tensile elongation at 25 ° C is 3% or more, it is judged that the stress relaxation effect can be exhibited. The results are shown in Tables 1 and 2.

(6) Heat resistance

A double-sided copper-clad laminate obtained by superposing four sheets of prepreg was cut into squares having four sides of 50 mm to obtain test pieces. The test piece was immersed in a solder bath at 260 ° C, and the time elapsed from the time point until the time when the test piece was confirmed to be inflated by the naked eye was measured. The measurement of the elapsed time was set to 300 seconds, and it was judged that the heat resistance was sufficient for 300 seconds or more. The results are shown in Tables 1 and 2.

(7) Evaluation of the adhesion of metal foil to the substrate

A portion of the copper foil of the double-sided copper clad laminate obtained by superposing four sheets of the prepreg was etched to form a copper foil wire of 3 mm width. Then, the copper foil line was measured at a speed of 50 mm/min toward 90 with respect to the adhesive surface. After the load in the direction peeling, the copper foil peeling strength was set. When the peeling strength of the copper foil is 0.5 kN/m or more, it is judged that the adhesiveness with the metal foil is sufficient. The results are shown in Tables 1 and 2.

(8) Phase structure observation test

The average area size of the island phase is smoothed by using a microtome to smooth the cross section of the resin insulating layer of the copper clad laminate obtained by laminating the resin-coated copper foil so that the resin faces face each other. After etching with a sulfate solution, an electron microscope was used to measure the maximum width and the minimum width of 70 or more island phases from the obtained cross-sectional structure, and the average value was calculated. The results are shown in Tables 1 and 2.

(9) Electrical insulation reliability

The electrical insulation reliability is a test pattern obtained by processing a double-sided copper-clad laminate obtained by superposing four sheets of prepregs so that the interval between the hole walls of the through holes is 350 μm, for each sample. The insulation resistance of 400 holes was measured over time. The measurement conditions were carried out by applying 100 V in an environment of 85 ° C / 85% RH, and the time until the conduction breakdown occurred was measured. The measurement time was set to 2000 hours, and it was judged that the electrical insulation reliability was sufficient for 1000 hours or more. The results are shown in Tables 1 and 2.

*1: The product name "KH-CT-865", manufactured by Hitachi Chemical Co., Ltd., (weight average molecular weight: Mw = 45 × 10 ⁴ ~ 65 × 10 ⁴ , as a compound represented by formula (1), contained in ester a part of a methacrylate having a cycloalkyl group having 5 to 10 carbon atoms and an acrylic polymer having no nitrile group in the structure)

*2: The product name "HTR-860P-3", manufactured by Nagase ChemteX Co., Ltd., (weight average molecular weight: Mw = 80 × 10 ⁴ , acrylic polymer containing no nitrile group in the structure)

*3: The product name "HAN5-M90S", manufactured by Geneda Industrial Co., Ltd., (weight average molecular weight: Mw = 90 × 10 ⁴ , acrylic polymer containing no nitrile group in the structure)

*4: Product name "N770", manufactured by DIC Corporation, (phenol novolak type epoxy resin)

*5: Product name "EPICLON 153", manufactured by DIC Corporation, (tetrabromobisphenol A epoxy resin)

*6: The product name "NC-3000H", manufactured by Nippon Kayaku Co., Ltd., (biphenyl aralkyl type epoxy resin)

*7: Product name "4005P", manufactured by Mitsubishi Chemical Corporation, (bisphenol F type epoxy resin)

*8: Product name "KA-1165", manufactured by DIC Corporation, (cresol novolac type resin)

*9: Product name "SC-2050KC", manufactured by Admatechs Co., Ltd. (melted spherical cerium oxide, decane coupling treatment, average particle size 0.5 μm)

*10: The product name "HK-001", manufactured by Kawato Lime Co., Ltd., (aluminum hydroxide, average particle size 4.0 μm)

*11: The product name "F05-12", manufactured by Fukushima Kiln Co., Ltd., (pulverized cerium oxide, average particle size 2.5 μm)

*12: The product name "F05-30", manufactured by Fukushima Kiln Co., Ltd., (pulverized cerium oxide, average particle size 4.2 μm)

*13: The product name "2PZ", manufactured by Shikoku Chemical Industry Co., Ltd., (2-phenylimidazole)

*14: Product name "A-187", manufactured by Dow Corning Toray Co., Ltd., (decane coupling agent)

As is apparent from Table 1, the examples of the present invention are excellent in low elasticity, heat resistance, adhesion to metal foil, and insulation reliability. On the other hand, in the comparative example, the low elasticity, the heat resistance, the adhesion to the metal foil, and the insulation reliability were not excellent at all.

When the resin composition, the prepreg, the metal foil-containing prepreg, the laminate, the metal-clad laminate, and the printed circuit board of the present invention have low elasticity, high insulation reliability, high heat resistance, and metal High adhesion between foils.

Claims (16)

A prepreg impregnated with a resin composition, wherein a first phase of the resin composition forms a phase separation structure with a second phase as an island phase, and an average region size of the island phase is 1 μm to 10 μm, and the resin composition The material contains (C) a filler, wherein the first phase contains (A) an acrylic polymer, and the second phase contains (B) a thermosetting resin. The prepreg according to claim 1, wherein when the total amount of the (A) acrylic polymer and the (B) thermosetting resin is 100 parts by mass, the (A) acrylic polymer The blending amount is 10 to 70 parts by mass. The prepreg according to claim 1 or 2, wherein the resin composition contains (C-1) a coupling-treated filler as the (C) filler. The prepreg according to any one of claims 1 to 3, wherein the resin composition contains (C-2) a non-coupling filler as the (C) filler. The prepreg according to any one of claims 1 to 4, wherein the (B) thermosetting resin comprises (B-1) an epoxy resin and (B-2) a phenol resin. The prepreg according to claim 5, wherein the (B-1) epoxy resin contains an epoxy resin having two or more epoxy groups in one molecule. The prepreg according to claim 5, wherein the (B-1) epoxy resin has a weight average molecular weight of 200 to 1,000. The prepreg according to any one of claims 5 to 7, wherein the epoxy resin of the (B-1) epoxy resin has an epoxy equivalent of from 150 to 500. The prepreg according to any one of claims 1 to 8, wherein the (A) acrylic polymer has a weight average molecular weight of 10,000 to 1,500,000. The prepreg according to any one of claims 5 to 9, wherein the (B-2) phenol resin contains a phenol resin having two or more hydroxyl groups in one molecule. The prepreg according to any one of claims 1 to 10, which contains cerium oxide as the (C) filler. The prepreg according to any one of claims 1 to 11, wherein the (C-2) filler has a volume average particle diameter of from 1.0 μm to 3.5 μm. A prepreg with a metal foil, which is obtained by laminating a prepreg according to any one of claims 1 to 12 with a metal foil. A laminate having a plurality of prepregs according to any one of claims 1 to 12. A metal-clad laminate in which the laminate according to claim 14 is further provided with a metal foil. A printed circuit board that makes the request item 14 The laminated board described above further has an electrical circuit.