TW202126741A - Prepregs, prepregs with metal foils, laminates, metal-clad laminates, and printed circuit boards - Google Patents

Abstract

The invention provides a prepreg, which is impregnated with a resin composition. The first phase of the resin composition and the second phase as the island phase form a phase separation structure, and the average domain size of the island phase is 1 [mu]m to 10 [mu]m. 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.

Description

Prepregs, prepregs with metal foils, laminates, metal-clad laminates and Printed circuit board

The present invention relates to a prepreg, a prepreg with metal foil, a laminated board, a metal-clad laminated board, and a printed circuit board.

With the rapid spread of information electronic equipment, the miniaturization and thinning of electronic equipment is gradually progressing, and there is an increasing demand for high-density and high-performance printed circuit boards mounted therein.

Since the thickness of the glass cloth as the base material is made thinner, for example, the thickness is 30μm or less, that is, the high density of the printed circuit board can be better achieved. Prepreg. As a result, although the density of printed circuit boards has gradually progressed, it is accompanied by difficulties in ensuring sufficient heat resistance, insulation reliability, and adhesion between the circuit layer and the insulating layer of the printed circuit boards.

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

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

As a circuit board material that meets these requirements, for example, a resin composition has been proposed in which a polymer acrylic polymer obtained by copolymerizing a crosslinkable functional group is blended with a thermosetting resin. The acrylic polymer is an acrylonitrile-butadiene-based resin, a carboxyl group-containing acrylonitrile-butadiene-based resin, etc. (for example, refer to Patent Documents 1 to 3).

[Prior Technical Literature]

(Patent Document)

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

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

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

A polyacrylate epoxy resin made by mixing a high molecular acrylic polymer (which is a crosslinkable functional group copolymerized) and a thermosetting resin. Its structure seems to be interconnected and regularly dispersed In the state, and the sea phase of the high molecular acrylic polymer and the island phase of the epoxy resin will form a phase separation structure, the main component of the sea phase is the high molecular propylene Acid-based polymer, the main component of the island phase is polyacrylate epoxy resin. A resin composition that forms a phase-separated structure and contains a high-molecular acrylic polymer and a polyacrylate epoxy resin. Although it is desired to have the excellent characteristics of both high-molecular acrylic polymer and epoxy resin, it has not yet fully achieved both Those with outstanding characteristics.

The high molecular acrylic polymer formed by copolymerization of crosslinkable functional groups is characterized by low elasticity, high elongation, and easy addition of functional groups. On the other hand, the thermosetting resin, that is, epoxy resin, is characterized by high insulation reliability, high heat resistance, and high glass transition temperature (Tg).

When the high-molecular acrylic polymer (which is obtained by copolymerizing crosslinkable functional groups) and epoxy resin (thermosetting resin) are uniformly mixed with each other to have a structure that is close to miscible in appearance, Epoxy resin is dispersed in the sea-phase mesh of high molecular acrylic polymer in nanometer size, so it tends to the characteristics of high molecular acrylic polymer, and the high insulation reliability of epoxy resin cannot be fully demonstrated. , High heat resistance, and high Tg. In addition, the surface area of the high molecular acrylic polymer, which has relatively weak adhesive strength with the metal foil, will increase, and the adhesion strength between the insulating layer and the metal foil will decrease.

On the other hand, in the phase separation structure, when the characteristics of the island phase are high, the characteristics of the island phase of the epoxy resin will be biased, and although the adhesion strength with the metal foil will increase, the polymer cannot be fully expressed Acrylic polymers have low elasticity and flexibility.

In addition, attempts are currently being made to introduce filler components for the purpose of imparting strength and heat resistance. However, it may cause aggregation and deposition of the components, increase in elasticity of the resin composition, and decrease in heat resistance, making it difficult to achieve a balance. In other words, it is difficult to form an insulating layer that sufficiently satisfies insulation reliability, high heat resistance, flexibility, and low elasticity.

The object of the present invention is to provide a prepreg, a prepreg with metal foil, a laminate, a metal-clad laminate, and a printed circuit board. The prepreg has low elasticity, insulation reliability, heat resistance, and is compatible with metal foil The adhesion between them is excellent.

The present invention relates to the following matters.

(1) A prepreg impregnated with a resin composition, the first phase of the resin composition and the second phase as the island phase form a phase separation structure, and the average domain size of the aforementioned 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 when the total amount of the (A) acrylic polymer and the (B) thermosetting resin is 100 parts by mass, the (A) acrylic 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 aforementioned (C) filler.

(4) The prepreg according to any one of (1) to (3), wherein the resin composition contains (C-2) a filler without coupling treatment as the aforementioned (C) filler.

(5) The prepreg according to any one of (1) to (4), wherein the (B) thermosetting resin includes (B-1) epoxy resin and (B-2) 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 weight average molecular weight of the (B-1) epoxy resin is 200 to 1,000.

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

(9) 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.

(10) The prepreg according to any one of (5) to (9), wherein the (B-2) phenol resin contains a phenol resin having two or more hydroxyl groups in one molecule.

(11) The prepreg according to any one of (1) to (10), which contains silica as the aforementioned (C) filler.

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

(13) A metal foil-attached prepreg formed by laminating the prepreg described in any one of (1) to (12) and metal foil.

(14) A laminated board having a plurality of prepregs according to any one of (1) to (12).

(15) A metal-clad laminated sheet obtained by further comprising the laminated sheet described in (14) with metal foil.

(16) A printed circuit board obtained by further including a circuit in the laminated board described in (14).

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

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

Figure 2 is a model diagram showing a case where the phase separation structure of the resin composition is a sea-island structure.

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

Figure 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 as an example of the resin composition having a sea-island structure obtained in the present invention.

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

[Preferable form for implementing the invention]

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

(Prepreg)

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

Regarding the reason why the component (A) does not form an island phase but a marine phase, we believe that the reason is as follows: in the component (A) which has a large molecular weight and is more entangled with each other, when the component (B) phase separates, (A) In order for the) component to become an island phase, the intertwining or interconnecting eye must be cut off, and it is not easy to become an island phase.

[Resin composition]

[Acrylic polymer: (A) component]

(A) Component is an acrylic polymer, usually a copolymer using alkyl (meth)acrylate 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 alkyl (meth)acrylate and a comonomer having a crosslinkable functional group. As the comonomer having a crosslinkable functional group, there are no particular restrictions as long as it is a compound that can be copolymerized with alkyl (meth)acrylate; as the crosslinkable functional group, it is preferable to have an epoxy group, and to have Glycidyl is preferred. As a 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 1 to 6 carbon atoms having a hydroxyl group, and a nitrogen-containing cyclic group.

Examples of alkyl (meth)acrylates include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, isobutyl acrylate, ethylene glycol mono Methyl ether acrylate, cyclohexyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, isobornyl acrylate, acrylamide, isodecyl acrylate, stearyl 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, methyl methacrylate 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, isobornyl methacrylate, methacrylamide, isodecyl methacrylate, stearyl methacrylate, lauryl methacrylate , Allyl methacrylate, N-vinylpyrrolidone methacrylate, acrylonitrile, etc.

When component (A) has an epoxy group, its epoxy group value is preferably 2 equivalents/kg to 18 equivalents/kg, preferably 2 equivalents/kg to 8 equivalents/kg. If the epoxy group value is 2 equivalent/kg or more, the glass transition temperature of the cured product can be suppressed, 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 glycidyl (meth)acrylate is copolymerized with another monomer that can be copolymerized therewith, the epoxy group value of the component (A) can be adjusted by appropriately adjusting the copolymerization ratio. Generally, relative to 100 parts by mass of glycidyl (meth)acrylate, the ratio of other monomers is set to 5 parts by mass to 15 parts by mass, that is, an epoxy group value with 2 equivalents/kg to 18 equivalents/kg can be obtained The high molecular acrylic polymer.

As a commercially available product of the component (A) having an epoxy group, for example, "HTR-860" (manufactured by Nagase ChemteX Co., Ltd., trade name, epoxy group value 3.1), "KH-CT-865" ( Hitachi Chemical Co., Ltd. product name, epoxy group value 3.0), "HAN5-M90S" (Negami Industry Co., Ltd. product name, epoxy group value 2.2). From the viewpoint of improving elongation and the viewpoint of improving low elasticity, the weight average molecular weight of component (A) is preferably 10,000 to 1,500,000, more preferably 50,000 to 1,500,000, and 300,000~1,500,000 is more preferred, and 300,000~1,100,000 is particularly preferred. If 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 easy to handle. In addition, if the weight average molecular weight of the component (A) is 1,500,000 or less, it tends to be difficult to form a phase-separated structure with a large co-continuous phase after the component (B) is formulated, and it is easy to exhibit high insulation reliability. , High heat resistance, the tendency of high adhesion to metal foil. If 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 expressed.

(A) The component can combine two or more types with different weight average molecular weights.

The above-mentioned weight average molecular weight is a value measured by gel permeation chromatography (GPC) analysis, and means a value converted to standard polystyrene. GPC analysis can be performed using tetrahydrofuran (THF) as a dissolving liquid.

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

In general, component (A) is obtained by using a radical polymerization initiator that generates radicals to radically polymerize monomers. Examples of radical polymerization initiators include azobisisobutyronitrile (AIBN), tertiary butyl perbenzoate, benzyl peroxide, lauryl peroxide, potassium persulfate, etc. Sulfate, cumene hydroxide, tertiary butyl hydrogen Peroxide, dicumenyl peroxide, di(tertiary butyl) peroxide, 2,2'-azobis-2,4-dimethylvaleronitrile, tertiary butyl perisobutyrate , Tertiary Butyl Peroxytrimethylacetate, Hydrogen Peroxide/Ferrous Salt, Persulfate/Sodium Bisulfite, Cumene Hydroperoxide/Ferrous Salt, Benzoyl Peroxide/Dimethyl Aniline and so on. As a radical polymerization initiator, it can use individually, and can also combine 2 or more types.

In the resin composition of the embodiment of the present invention, when the total amount of the (A) component and the (B) component is 100 parts by mass, the blending amount of the (A) component is preferably 10 to 70 parts by mass. If the blending amount of the component (A) is less than 10 parts by mass, there is a tendency that the excellent feature of the component (A), that is, low elasticity, will not be effectively expressed. In addition, if the blending amount of the component (A) exceeds 70 parts by mass, there is a tendency that good adhesive strength with the metal foil cannot be obtained, or the flame retardancy tends to decrease.

In addition, especially from the viewpoint of low elasticity, in 100 parts by mass of the total amount of (A) component and (B) component, the blending amount of (A) component is preferably 15 parts by mass or more, and 20 parts by mass The above is preferable, and 30 parts by mass or more is more preferable.

In addition, especially from the viewpoint of obtaining good adhesive strength with metal foil, the blending amount of (A) component is 60 parts by mass or less in the total amount of (A) component and (B) component 100 parts by mass More preferably, it is preferably 50 parts by mass or less, and more preferably 40 parts by mass or less.

[Thermosetting resin: (B) component]

As the (B) component used in the present invention, it is suitable to select a compound having a phase separation structure after being combined with the (A) component and hardened. As (B) The ingredients are not particularly limited. Examples include epoxy resins, cyanate ester resins, bismaleimide resins, addition polymers of bismaleimide resins and diamines, phenol resins, and resols. Varnish (resol) resin, isocyanate resin, triallyl isocyanurate resin, triallyl cyanurate resin, vinyl-containing polyolefin compound, etc. Among these, if the balance of heat resistance, insulation and other properties is considered, epoxy resin or cyanate ester resin is preferred.

When the component (B) hardens the resin composition of the embodiment of the present invention, a resin composite having a phase separation structure can be formed. The component (B) is preferably a resin composition containing: (B-1) Epoxy resin, which has two or more epoxy groups in one molecule (hereinafter referred to as "(B-1)" component); and (B-2) phenol resin, which has 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) preferably contains the component (B-1).

(B-1) The weight average molecular weight of the component is preferably 200 to 1,000, and more preferably 300 to 900. If the weight average molecular weight is 200 or more, it tends to form a phase-separated structure with component (A). If the weight average molecular weight is 1,000 or less, it tends to easily form a phase-separated structure with a smaller second phase. And there is a tendency to show low elasticity.

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

As the (B-1) component, conventional materials can be used, and examples include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, biphenyl type epoxy resin, and phenol Novolac 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 aralkylene skeleton , Phenol biphenyl aralkyl type epoxy resin, phenol salic novolak epoxy resin, phenol salic novolak epoxy resin substituted by lower alkyl groups, epoxy resin containing dicyclopentadiene skeleton, Multifunctional glycidylamine epoxy resin, multifunctional alicyclic epoxy resin, tetrabromobisphenol A epoxy resin, etc. One or two or more of these can be used.

Examples of commercially available products of the component (B-1) include phenol novolak type epoxy resin "N770" (manufactured by DIC Co., Ltd., trade name), and tetrabromobisphenol A type epoxy resin "EPICLON 153" (Manufactured by DIC Co., Ltd., trade name), biphenyl aralkyl epoxy resin "NC-3000H" (manufactured by Nippon Kayaku Co., Ltd., trade name), bisphenol A epoxy resin "Epikote 1001" ( Produced by Mitsubishi Chemical Corporation, trade name), phosphorous epoxy resin "ZX-1548" (manufactured by Toto Kasei Co., Ltd., trade name), cresol novolac type epoxy resin "EPICLON N-660" (DIC Co., Ltd.) Limited company system, trade name), etc.

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

From the viewpoint of ensuring the adhesion strength with the metal foil, the component (B) preferably contains the component (B-2).

As the component (B-2), conventional materials can be used. Examples include aralkyl phenol resins, dicyclopentadiene phenol resins, salicylic phenol resins, benzaldehyde phenol resins, and aralkyl phenol resins. Copolymer resins obtained from phenol resins, and novolac phenol resins, etc. One or two or more of these can be used.

From the viewpoint of low water absorption, as the component (B-2), it is preferable to use polyphenols such as phenol novolac.

Examples of commercially available products of the component (B-2) include cresol novolac resin "KA-1165" (manufactured by DIC Co., Ltd., trade name), and biphenol novolac resin "MEH-7851" (Minghe Chemical Co., Ltd. system, trade name), etc.

(B-2) The blending ratio of the components is usually determined by increasing the glass transition temperature. For example: when using a phenol novolak type resin as the component (B-2), the epoxy group of the component (B-1) is preferably 0.5 to 1.5 equivalents. The epoxy group of the component (B-1) is 0.5 to 1.5 equivalents, which can prevent the adhesion with the outer layer copper from decreasing, and can also prevent the glass transition temperature (Tg) and insulation from decreasing.

<(B) component hardener>

The resin composition of the present invention may contain the curing agent of the component (B). As the curing agent of the component (B), conventional materials can be used. Examples include amine hardeners such as dicyandiamide, diaminodiphenylmethane, and diaminodiphenyl sulfide; acid anhydride hardeners such as pyromellitic anhydride, trimellitic anhydride, and benzophenone tetracarboxylic acid ; Or a mixture of these, etc.

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

Generally speaking, the phase structure of the resin cured product is determined by the competitive reaction between the phase separation speed and the crosslinking reaction speed. Taking epoxy resin as an example, controlling the catalyst species and skeleton structure, etc., and mixing and curing epoxy resins with different characteristics, can form a phase separation structure with an average domain size of about 1 μm to 10 μm. That is, the island structure.

[Filling: (C) component]

The resin composition of the embodiment of the present invention preferably contains one or more types of silicon oxide as the (C) component. 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) component") as the (C) component. In addition, the tree composition of the embodiment of the present invention preferably contains (C-2) a filler without coupling treatment (hereinafter referred to as "(C-2) component") as the (C) component.

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

(C-1) The average particle size of the component is preferably 0.1 μm to 1.5 μm, preferably 0.2 μm to 1.2 μm, and more preferably 0.3 μm to 1.0 μm. If the average particle size of the component (C-1) is 0.1μm or more, the fillers tend to disperse easily after varnishing and do not easily aggregate. If the average particle size of the component (C-1) is 1.5μm or less , There is a tendency that the component (C) is not easy to deposit during varnishing.

(C-2) The average particle size of the component is preferably 1.0 μm to 3.5 μm, preferably 1.2 μm to 3.2 μm, and more preferably 1.4 μm to 3.0 μm. If the average particle size of the component (C-2) is 1.0μm or more, the fillers tend to disperse easily and not agglomerate. If the average particle size of the component (C-2) is 3.5μm or less, there is a tendency for The component (C) does not tend to deposit easily during varnishing.

Here, the so-called average particle size refers to the particle size at the point equivalent to 50% of the volume when the total volume of the particles is set to 100% to obtain the cumulative power distribution curve obtained from the particle size. The measurement is performed by a particle size distribution measuring device of the diffraction scattering method.

The (C) component used in the present invention can be conventionally used. For the purpose of reducing the thermal expansion coefficient and ensuring the flame retardancy, it is preferable to add an inorganic filler. As inorganic fillers, for example: silicon oxide, aluminum oxide, titanium oxide, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, calcium oxide, magnesium oxide, aluminum nitride, boric acid Aluminum whiskers, boron nitride, silicon carbide, etc. Among them, since the dielectric constant is low and the linear expansion coefficient is low, it is more preferable to use silicon oxide.

As the silica used in the present invention, the following various silicas can be used: various synthetic silicas synthesized by a wet method or a dry method or pulverized silica obtained by pulverizing silica; using a wet method or A variety of synthetic silica synthesized by dry method or fused silica formed by temporary melting of silica.

In the present invention, the blending ratio of component (C) is preferably 5 mass% to 40 mass% of the solid content of all resin compositions, and preferably 10 mass% to 35% by mass of the solid content of all resin compositions. It is more preferable to use 15% by mass to 30% by mass of the solid content of all resin compositions. The blending ratio of component (C) is 40% by mass or less, and the insulating resin does not become brittle and can obtain sufficient polymer acrylic polymer by copolymerizing the crosslinkable functional group of component (A) The tendency to have low elasticity and flexibility. In addition, when the blending ratio of the component (C) is 5 mass% or more, the linear expansion coefficient tends to decrease and sufficient heat resistance can be obtained.

In this specification, the term "solid content" refers to the non-volatile content remaining after removing solvents and other volatile substances, and refers to the non-volatile components remaining after the resin composition is dried, and it is also included in It is liquid, maltose and waxy ingredients at room temperature. Here, in this specification, room temperature means 25°C.

<hardening accelerator>

The resin composition may contain a hardening accelerator. The hardening accelerator is not particularly limited, but amines or imidazoles are preferred. Examples of amines include dicyandiamide, diaminodiphenylethane, formamidinourea, and the like. Examples of imidazoles include: 2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-phenylimidazole, Trimellitic acid 1-cyanoethyl-2-imidazolium salt, benzimidazole and the like.

The blending amount of the hardening accelerator can be determined according to the total amount of the ethylene oxide ring in the resin composition. Generally speaking, it is set to 0.01 parts by mass in 100 parts by mass of the resin solid component of the resin composition. 10 parts by mass is preferable, 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, as required, for example: crosslinking agent, flame retardant, flow regulator, conductive particles, coupling agent, pigment, leveling agent, defoamer, ion trap agent, antioxidant, etc. , And can use conventional objects.

<Solvent>

When the resin composition of the present invention is used to produce a prepreg, etc., it can be made into a varnish in which the components of the resin composition of the present invention are dissolved or dispersed in an organic solvent.

When the resin composition of the present invention is made into a varnish, the organic solvent used is not particularly limited, and ketone-based, aromatic hydrocarbon-based, ester-based, amide-based, alcohol-based, etc. can be used.

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

As an aromatic hydrocarbon solvent, toluene, xylene, etc. are mentioned, for example.

Examples of ester solvents include methoxyethyl acetate, ethoxyethyl acetate, butoxyethyl acetate, ethyl acetate, and the like.

Examples of amide-based solvents include N-methylpyrrolidone, formamide, N-methylformamide, N,N-dimethylacetamide, and the like.

Examples of alcohol-based solvents 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, etc.

These organic solvents can be used singly or in combination of two or more.

[Phase Separation Structure]

In the present invention, the so-called phase separation structure refers to: sea-island structure, continuous spherical structure, composite dispersed phase structure, co-continuous phase structure, and the average domain size of the island phase is 1μm~10μm, preferably 1μm~9μm. 2μm~8μm is preferred.

If the average domain size of the island phase is less than 1 μm, it tends to be difficult to express the good insulation reliability and high heat resistance of the thermosetting resin (B). In addition, there is a tendency that the surface area of the acrylic polymer, which has a relatively weak adhesive strength with the metal foil, becomes large, and good adhesive strength between the insulating layer and the metal foil cannot be obtained.

In addition, if the average domain size of the island phase exceeds 10 μm, it tends to be difficult to express the low elasticity of the component (A).

Here, the so-called average area size of the island phase refers to the use of a microtome to smooth the cross-section of the resin composition after heat curing, and an electron microscope to obtain more than 70 cross-sectional structures. The maximum width and minimum width of the island phase were measured, and the average value was calculated.

In addition, the island structure, continuous spherical structure, composite dispersed phase structure, and co-continuous phase structure (also called continuous phase structure) as the phase separation structure have been described in, for example, "Polymer Alloys" page 325 (1993) Tokyo It is described in detail in chemistry colleagues, and the continuous spherical structure has been described in detail in, for example, Keizo Yamanaka and Takashi Iniue, POLYMER, Vol. 30, pp. 662 (1989).

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

Such a fine phase separation structure is obtained by controlling the curing conditions such as the catalyst species and reaction temperature of the resin composition, or the compatibility between the components of the resin composition. In order to make the phase separation easy to occur, it can be achieved by the following methods, for example: using an epoxy resin substituted by an alkyl group to reduce the compatibility with the high-molecular acrylic polymer, or as the same composition system At the same time, increase the hardening temperature, or reduce the hardening speed by selecting the catalyst species.

Fig. 5 shows an electron micrograph showing the cross-sectional structure of an example of the resin composition having a sea-island structure obtained in the above-mentioned manner. As shown in the figure, the resin composition has a sea-island structure, which is composed of an acrylic polymer phase and an epoxy resin-rich phase. In addition, the average domain size of the island phase made of epoxy resin is about 1 μm to 10 μm. By having such a phase separation structure, it can have both the following excellent characteristics: low elasticity of acrylic polymer; and high insulation reliability, high heat resistance of thermosetting resin, and metal High adhesion between foils.

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

[Manufacturing method of prepreg]

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

The base material is not particularly limited as long as it is a base material used in the production of a metal-clad laminated board, a printed circuit board, etc., and a fibrous base material such as a woven fabric or a non-woven fabric is usually used. As the material of the fiber substrate, for example, glass, alumina, asbestos, boron, silica alumina glass, silica glass, Tyranno, silicon carbide, silicon nitride, zirconium oxide and other inorganic fibers; aramid, polyether ether ketone, polyether imide, polyether ash, carbon, cellulose and other organic fibers; and mixed systems of these. Among these, glass cloth is preferable, glass cloth having a thickness of 100 μm or less is preferable, and glass cloth having a thickness of 50 μm or less is particularly preferable. If the thickness of the glass cloth is 50 μm or less, a printed circuit board that can be bent arbitrarily can be obtained, and the dimensional change due to temperature, moisture absorption, etc. in the manufacturing process is small, which is preferable.

It is preferable that the organic solvent used in the varnish of the obtained prepreg has volatilized more than 80% by mass. If the organic solvent used in the varnish has volatilized more than 80% by mass, there are no restrictions on the manufacturing method, drying conditions, etc. During drying, the temperature is, for example, 80°C to 180°C, and the time is appropriately set taking into account the gelation time of the varnish . In addition, it is preferable to set the impregnation amount of the varnish so that the solid content of the varnish becomes 30% by mass to 80% by mass relative to the total amount of the solid content of the varnish and the substrate.

(Prepreg with metal foil)

The prepreg with metal foil of the present invention is preferably formed by laminating the above-mentioned prepreg and metal foil.

The prepreg with metal foil of the present invention can be manufactured in the following manner. For example, the metal foil is superimposed on one or both sides of the prepreg of the present invention, and the temperature is usually 130°C to 250°C, preferably The temperature is in the range of 150°C to 230°C, and it 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 pressing is also not particularly limited, and for example, multi-stage pressurization, multi-stage vacuum pressurization, continuous molding, autoclave molding machine, etc. can be used.

Moreover, when manufacturing the prepreg with metal foil of this invention, the metal foil used is not specifically limited, For example, copper foil, 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 use, for example: nickel, nickel-phosphorus, nickel-tin alloy, nickel-iron alloy, lead, lead-tin alloy, etc. as the intermediate layer, with 0.5μm~15μm copper layer and 10μm~300μm on both sides A three-layer structure composite foil made of copper layers; or a two-layer structure composite foil made of aluminum and copper foil.

(Laminate)

The laminated board of the present invention preferably has a plurality of the above-mentioned prepregs.

The laminated sheet of the present invention is, for example, formed by heating and pressing the prepreg bulk layer of the present invention. The method of heating and pressing is not particularly limited, and, for example, multi-stage pressurization, multi-stage vacuum pressurization, continuous molding, autoclave molding machine, etc. can be used.

(Metal Clad Laminate)

The metal-clad laminated sheet of the present invention is preferably formed by further including a metal foil on the laminated sheet.

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

Moreover, when manufacturing the metal-clad laminated board of this invention, the metal foil used is not specifically limited, For example, copper foil, 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 use, for example: nickel, nickel-phosphorus, nickel-tin alloy, nickel-iron alloy, lead, lead-tin alloy, etc. as the intermediate layer, with 0.5μm~15μm copper layer and 10μm~300μm on both sides A three-layer structure composite foil made of copper layers; or a two-layer structure composite foil made of aluminum and copper foil.

(Printed circuit board)

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

The manufacturing method of the printed circuit board of the present invention is not particularly limited, and it can be manufactured by implementing a circuit on the metal foil of the laminate (metal-clad laminate) of the present invention provided with metal foil on one or both sides (Line) processing.

[Example]

Hereinafter, examples are given to specifically illustrate the present invention, but the present invention is not limited by these examples. In addition, the numerical values in the following examples mean mass% unless otherwise specified.

[Example 1~Example 13]

The (A) component, (B-1) component, (B-2) component, (C-1) component, and (C-2) component were blended in the blending amounts shown in Table 1, and these components After dissolving in methyl ethyl ketone, the component (D) and coupling agent were blended according to Table 1 to obtain a resin composition varnish with a non-volatile content of 40%.

[Comparative Example 1~Comparative Example 10]

Mix (A) component, (B-1) component, (B-2) component, (C-1) component, (C-2) component in the mixing amount shown in Table 2, and dissolve these components After in the methyl ethyl ketone, the component (D) was blended according to Table 2 to obtain a resin composition varnish with a non-volatile content of 40%.

[Production of prepreg, metal foil with resin, and metal-clad laminate]

(1) Production of prepreg

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

(2) Production of copper foil with resin

Use a coater to coat the varnishes prepared in Examples 1 to 13 and Comparative Examples 1 to 10 on 18μm thick electrolytic copper foil "YGP-18" (manufactured by Nippon Electrolytic Co., Ltd., trade name) Molded and dried with hot air at 140°C for about 6 minutes to obtain a resin-coated copper foil with a coating thickness of 50μm.

(3) Production of metal-clad laminate (copper-clad laminate)

After stacking 4 sheets of the prepreg made in (1), an 18μm thick electrolytic copper foil "YGP-18" (manufactured by Nippon Electrolytic Co., Ltd., trade name) is applied so that the adhesive surface and the prepreg are in close contact The way overlaps the overlapped On both sides of the prepreg, double-sided copper clad laminates were made under vacuum pressure at 200°C for 60 minutes and 4MPa. In addition, the resin-coated copper foil was overlapped so that the resin surfaces face each other, and a double-sided copper-clad laminate was fabricated under vacuum pressure conditions at 200°C for 60 minutes and 4 MPa.

[Evaluation method of varnish, prepreg and metal-clad laminate]

(1) Varnish properties

The evaluation of varnish properties is to put the prepared varnish into a transparent container and observe the appearance after 24 hours by naked eyes to observe the separation of varnish components and deposits. If the varnish has a uniform hue, it is judged as not separated. In addition, when it is impossible to visually confirm that there is deposit accumulation on the bottom of the container, it is judged that there is no deposit. The results are shown in Tables 1 and 2.

(2) The viscosity of the prepreg

The evaluation of the viscosity of the prepreg is to process the prepared prepreg into a size of 250mm×250mm and overlap 100 pieces, then put it into a bag that can be sealed in a hermetically sealed manner, and then put it in a bag with a temperature of 25°C and a humidity of 70%. In a constant temperature and humidity environment, observe whether the prepregs adhere to each other. After 48 hours, after peeling off the prepreg arranged at the bottom and the prepreg adjacent to it, when each prepreg maintains the surface before being put in, it is determined that there is no adhesion, and it is judged that there is no adhesion. problem. The results are shown in Tables 1 and 2.

(3) The appearance of the prepreg (the presence or absence of agglomerates)

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

(4) Storage elastic modulus

The evaluation of the storage elastic modulus is to etch the entire surface of the copper-clad laminate made by overlapping the resin-coated copper foil so that the resin faces face each other to obtain the laminate, and cut the laminate into After a width of 5 mm × a length of 30 mm, a dynamic viscoelasticity measuring device (manufactured by UBM Co., Ltd.) was used to calculate the storage elastic modulus. If 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 expressed. The results are shown in Tables 1 and 2.

(5) Tensile elongation

The evaluation of the tensile strength is to etch the entire surface of the copper-clad laminate made by overlapping the resin-coated copper foil so that the resin faces face each other to obtain the laminate, and cut the laminate into After a width of 10 mm × a length of 100 mm, an autograph (manufactured by Shimadzu Corporation) was used to calculate the elongation resistance rate. If the tensile length resistance at 25°C is 3% or more, it is judged that the stress relaxation effect can be expressed. The results are shown in Tables 1 and 2.

(6) Heat resistance

The double-sided copper-clad laminated board made of 4 overlapped prepregs was cut into a square with four sides of 50 mm to obtain a test piece. The test piece was immersed in a solder bath at 260°C, and the time elapsed from this point in time to the point in time when the test piece swelling can be confirmed with the naked eye was measured. The elapsed time was measured until 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 part of the copper foil of the double-sided copper-clad laminate made of 4 sheets of prepreg was etched to form a copper foil wire with a width of 3 mm. Then, after measuring the load when the copper foil wire is peeled in a direction of 90° with respect to the adhesive surface at a speed of 50 mm/min, it is set as the copper foil peeling strength. If the copper foil peel strength is 0.5 kN/m or more, it is judged that the adhesion to 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 obtained by using a slicer to smooth the cross section of the resin insulating layer of the copper clad laminate made by overlapping 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 minimum width of 70 or more island phases from the obtained cross-sectional structure, and calculate the average value. The results are shown in Tables 1 and 2.

(9) Electrical insulation reliability

Electrical insulation reliability is a test pattern formed by processing a double-sided copper-clad laminate made of 4 sheets of prepreg so that the distance between the walls of the through-holes becomes 350μm. For each sample The insulation resistance of 400 holes was measured over time. The measurement condition is to apply 100V in an environment of 85°C/85% RH, and measure the time until conduction failure occurs. 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.

[Table 1]

[Table 2]

※1: Trade name "KH-CT-865", manufactured by Hitachi Chemical Co., Ltd., (weight average molecular weight: Mw=45×10 ⁴ ~65×10 ⁴ , as the compound represented by formula (1), containing in ester Part of the methacrylate with carbon 5-10 cycloalkyl and acrylic polymer without nitrile group in the structure)

※2: Trade name "HTR-860P-3", manufactured by Nagase ChemteX Co., Ltd. (weight average molecular weight: Mw=80×10 ⁴ , acrylic polymer without nitrile group in the structure)

※3: Trade name "HAN5-M90S", manufactured by Nejo Industrial Co., Ltd. (weight average molecular weight: Mw=90×10 ⁴ , acrylic polymer without nitrile group in the structure)

※4: Trade name "N770", manufactured by DIC Co., Ltd. (phenol novolac type epoxy resin)

※5: Trade name "EPICLON 153", manufactured by DIC Co., Ltd. (Tetrabromobisphenol A epoxy resin)

※6: Trade name "NC-3000H", manufactured by Nippon Kayaku Co., Ltd. (Biphenyl aralkyl type epoxy resin)

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

※8: Trade name "KA-1165", manufactured by DIC Co., Ltd. (cresol novolac type resin)

※9: Trade name "SC-2050KC", manufactured by Admatechs Co., Ltd. (Molten spherical silica, silane coupling treatment, average particle size 0.5μm)

※10: Trade name "HK-001", manufactured by Kawai Lime Co., Ltd. (aluminum hydroxide, average particle size 4.0μm)

※11: Trade name "F05-12", manufactured by Fukushima Ceramics Co., Ltd. (Crushed silica, average particle size 2.5μm)

※12: Trade name "F05-30", manufactured by Fukushima Ceramics Co., Ltd. (Crushed silica, average particle size 4.2μm)

※13: Trade name "2PZ", manufactured by Shikoku Chemical Industry Co., Ltd., (2-phenylimidazole)

※14: Trade name "A-187", manufactured by Dow Corning Toray Co., Ltd. (Silane coupling agent)

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

If the resin composition, prepreg, prepreg with metal foil, laminate, metal-clad laminate, and printed circuit board of the present invention are used, it has low elasticity, high insulation reliability, high heat resistance, and is compatible with metal High adhesion between foils.

Claims (16)

A prepreg impregnated with a resin composition, the first phase of the resin composition and the second phase as the island phase form a phase separation structure, and the average area size of the aforementioned island phase is 1 μm to 10 μm, and the resin composition The substance 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 10~70 parts by mass. The prepreg according to claim 1 or 2, wherein the resin composition contains (C-1) a coupling-treated filler as the aforementioned (C) filler. The prepreg according to any one of claims 1 to 3, wherein the resin composition contains (C-2) an uncoupling filler as the aforementioned (C) filler. The prepreg according to any one of claims 1 to 4, wherein the (B) thermosetting resin includes (B-1) epoxy resin and (B-2) 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 or 6, wherein the weight average molecular weight of the (B-1) epoxy resin is 200 to 1,000. The prepreg according to any one of claims 5 to 7, wherein the epoxy equivalent of the (B-1) epoxy resin is 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 silica as the aforementioned (C) filler. The prepreg according to any one of claims 1 to 11, wherein the volume average particle size of the aforementioned (C-2) filler is 1.0 μm to 3.5 μm. A prepreg with metal foil, which is formed by laminating the prepreg described in any one of claims 1 to 12 and metal foil. A laminated board having a plurality of prepregs according to any one of claims 1 to 12. A metal-clad laminated board, which is obtained by further including metal foil on the laminated board described in claim 14. A printed circuit board, which is used in claim 14 The laminated board described above is further formed with a circuit.

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