WO2017195344A1

WO2017195344A1 - Prepreg, metal-foil-equipped prepreg, laminate plate, metal-clad laminate plate, and printed circuit board

Info

Publication number: WO2017195344A1
Application number: PCT/JP2016/064253
Authority: WO
Inventors: 貴代北嶋; 健一富岡; 垣谷　稔
Original assignee: 日立化成株式会社
Priority date: 2016-05-13
Filing date: 2016-05-13
Publication date: 2017-11-16
Also published as: JPWO2017195344A1; JP6996500B2

Abstract

A prepreg impregnated with a resin composition in which (A) a first phase including an acrylic polymer and (B) a second phase serving as an island phase including a thermosetting resin form a phase separation structure, with the average domain size of the island phase being 1-10 µm, and (C) a filler is contained.

Description

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

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

With the rapid spread of information electronic devices, electronic devices are becoming smaller and thinner, and the demand for higher density and higher functionality of printed circuit boards mounted therein is increasing.

Densification of the printed circuit board can be achieved more suitably by reducing the thickness of the glass cloth as a base material, for example, by making the thickness to 30 μm or less. Prepreg has been developed and marketed recently. As a result, although the density of printed circuit boards is increasing, it is possible to ensure sufficient heat resistance, insulation reliability and adhesion between the wiring layer and the insulating layer in the printed circuit board. It has become difficult.

The wiring board material used for such a high-performance printed circuit board is required to have heat resistance, electrical insulation, long-term reliability, adhesiveness, and the like. In addition to the above properties, the flexible wiring board material listed as one of these high-performance printed circuit boards is also required to have low elasticity.

Furthermore, in a printed circuit board on which ceramic parts are mounted, there are problems of differences in thermal expansion coefficients between the ceramic parts and the printed circuit board, and component connection reliability caused by external impact. As a solution to this problem, stress relaxation from the printed circuit board side can be mentioned.

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

JP-A-8-283535 JP 2002-134907 A JP 2002-371190 A

Polyacrylate epoxy resin, which is a mixture of polymer acrylic polymer copolymerized with crosslinkable functional groups and thermosetting resin, is as if it is connected to each other and regularly dispersed. A phase-separated structure is formed between the sea phase of the polymer acrylic polymer, which is an acrylic polymer, and the island phase of the epoxy resin, the main component of which is a polyacrylate epoxy resin. A resin composition containing a polymer acrylic polymer having a phase-separated structure and a polyacrylate epoxy resin is desired to have the excellent characteristics of both a polymer acrylic polymer and an epoxy resin. None of them had excellent characteristics.
The characteristics of the polymer acrylic polymer copolymerized with a crosslinkable functional group are low elasticity, high elongation, and easy insertion of a functional group. On the other hand, the characteristics of the epoxy resin that is a thermosetting resin are high insulation reliability, high heat resistance, high glass transition temperature (Tg), and the like.

If a polymer acrylic polymer copolymerized with crosslinkable functional groups and an epoxy resin (thermosetting resin) are uniformly mixed and apparently have a structure close to compatibility, an epoxy is formed in the network of the polymer acrylic polymer sea phase. Since the resin is dispersed in a nano size, the characteristics of the polymer acrylic polymer are biased, and the high insulation reliability, high heat resistance, and high Tg that the epoxy resin has cannot be sufficiently expressed. Further, the surface area of the polymer acrylic polymer having relatively weak adhesion strength with the metal foil is increased, and the adhesion strength between the insulating layer and the metal foil is lowered.
On the other hand, in the phase separation structure, when the ratio of the island phase is high, the characteristics of the island phase of the epoxy resin are biased and the adhesion strength with the metal foil is improved, but the low elasticity and flexibility of the polymer acrylic polymer are sufficient. Cannot be expressed.

Furthermore, introduction of a filler component has been attempted for the purpose of imparting strength and heat resistance, but it has been difficult to achieve a balance by causing aggregation and sedimentation of the component, higher elasticity of the resin composition and lowering of heat resistance. It was. That is, it has been difficult to form an insulating layer that satisfies all of 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 metal-clad laminate, and a printed circuit board that are excellent in low elasticity, insulation reliability, heat resistance, and adhesion to a metal foil. .

The present invention relates to each item described below.
(1) (A) A first phase containing an acrylic polymer and (B) a second phase as an island phase containing a thermosetting resin form a phase separation structure, and the average domain size of the island phase is 1 μm to A prepreg that is 10 μm and (C) impregnated with a resin composition containing a filler.
(2) The blending amount of the (A) acrylic polymer is 10 to 70 parts by mass when the total amount of the (A) acrylic polymer and the (B) thermosetting resin is 100 parts by mass. The prepreg as described.
(3) The prepreg according to (1) or (2), which contains (C-1) a coupling-treated filler as the (C) filler.
(4) The prepreg according to any one of (1) to (3), wherein (C-2) a filler not subjected to coupling treatment is contained as the (C) filler.
(5) The prepreg according to any one of (1) to (4), wherein the (B) thermosetting resin contains (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 weight average molecular weight of the (B-1) epoxy resin is 200 to 1,000.
(8) The prepreg according to (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 acrylic polymer (A) 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 filler (C).
(12) The prepreg according to any one of (1) to (11), wherein the volume average particle size of the (C-2) filler is 1.0 μm to 3.5 μm.
(13) A prepreg with a metal foil obtained by laminating the prepreg according to any one of (1) to (12) and a metal foil.
(14) A laminate having a plurality of the prepregs according to any one of (1) to (12).
(15) A metal-clad laminate in which the laminate according to (14) further has a metal foil.
(16) A printed circuit board in which the laminated board according to (14) further has a circuit.

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

It is a model figure showing the case where the phase-separation structure of a resin composition is a continuous spherical structure. It is a model figure showing the case where the phase-separation structure of a resin composition is a sea-island structure. It is a model figure showing the case where the phase-separation structure of a resin composition is a composite dispersed phase structure. It is a model figure showing the case where the phase-separation structure of a resin composition is a bicontinuous phase structure. It is an electron micrograph showing the cross-sectional structure as an example of the resin composition which has the sea island structure obtained by this invention. It is an electron micrograph showing the cross-sectional structure as an example of the resin composition which has the composite dispersed phase structure obtained by this invention.

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

(Prepreg)
The prepreg according to the embodiment of the present invention includes a first phase containing (A) an acrylic polymer (hereinafter referred to as “component (A)”), and (B) a thermosetting resin (hereinafter referred to as “(B)”. And the second phase as an island phase containing a component)) forms a phase separation structure, and the average domain size of the island phase is 1 μm to 10 μm. (C) filler component (hereinafter referred to as “(C) It is a prepreg impregnated with a resin composition containing “component”.
The reason why the component (A) forms the sea phase instead of the island phase is that when the phase separation of the component (B) occurs in the component (A) having a large molecular weight and a large amount of entanglement, the component (A) In order to become a phase, it is considered that the entanglement and cross-linking network must be cut, and it is difficult to become an island phase.

[Resin composition]
[Acrylic polymer: component (A)]
The component (A) is an acrylic polymer, and is usually a copolymer having a (meth) acrylic acid alkyl ester as a monomer. As the copolymer, an acrylic polymer copolymerized with a crosslinkable functional group is preferable. Such a copolymer is generally produced by copolymerizing a (meth) acrylic acid alkyl ester and a copolymerizable monomer having a crosslinkable functional group. The copolymerizable monomer having a crosslinkable functional group is not particularly limited as long as it is a compound copolymerizable with (meth) acrylic acid alkyl ester, and the crosslinkable functional group preferably has an epoxy group, and glycidyl. It is more preferable to have a group. As the copolymerizable monomer having a crosslinkable functional group, glycidyl (meth) acrylate is preferably used. In the (meth) acrylic acid alkyl ester, 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 (meth) acrylic acid alkyl esters include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, isobutyl acrylate, ethylene glycol methyl ether acrylate, and acrylic. Cyclohexyl acid, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, isobornyl acrylate, amide acrylate, isodecyl acrylate, octadecyl acrylate, lauryl acrylate, allyl acrylate, N-vinylpyrrolidone acrylate, methacrylic acid Methyl, ethyl methacrylate, propyl methacrylate, butyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, isobutyl methacrylate, ethyl methacrylate Lenglycol methyl ether, cyclohexyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, isobornyl methacrylate, methacrylic acid amide, isodecyl methacrylate, octadecyl methacrylate, lauryl methacrylate, allyl methacrylate, N methacrylate -Vinylpyrrolidone, acrylonitrile and the like.

When the component (A) has an epoxy machine, the epoxy value is preferably 2 equivalent / kg to 18 equivalent / kg, more preferably 2 equivalent / kg to 8 equivalent / kg. When the epoxy value is 2 equivalents / kg or more, a decrease in the glass transition temperature of the cured product is suppressed, and the heat resistance of the substrate is sufficiently maintained. When the epoxy value is 18 equivalents / kg or less, the storage elastic modulus becomes too large. Without tending, the dimensional stability of the substrate tends to be maintained. The epoxy value of the component (A) can be adjusted by appropriately adjusting the copolymerization ratio when copolymerizing glycidyl (meth) acrylate and another monomer copolymerizable therewith. Usually, a polymer having an epoxy value of 2 equivalents / kg to 18 equivalents / kg is obtained by setting the ratio of other monomers to 5 to 15 parts by mass with respect to 100 parts by mass of glycidyl (meth) acrylate. An acrylic polymer is obtained.

Commercially available products of component (A) having an epoxy group include, for example, “HTR-860” (manufactured by Nagase ChemteX Corporation, product name, epoxy value 3.1), “KH-CT-865” (Hitachi Chemical Co., Ltd.) Company name, product name, epoxy value 3.0), “HAN5-M90S” (manufactured by Negami Kogyo Co., Ltd., product name, epoxy value 2.2) are available. The weight average molecular weight of the component (A) is preferably 10,000 to 1,500,000 from the viewpoint of improving elongation and improving low elasticity, and is preferably 50,000 to 1,500,000. Is more preferable, 300,000 to 1,500,000 is more preferable, and 300,000 to 1,100,000 is particularly preferable. When the weight average molecular weight of the component (A) is 1,500,000 or less, the component tends to be easily dissolved in a solvent and easy to handle. Moreover, when the weight average molecular weight of the component (A) is 1,500,000 or less, when the component (B) is blended, it tends to be difficult to form a phase separation structure having a relatively large co-continuous phase of the domain. In addition, high insulation reliability, high heat resistance, and high adhesiveness with metal foil tend to be developed. 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 developed.
(A) A component may combine 2 or more types from which a weight average molecular weight differs.
The weight average molecular weight is a value measured by gel permeation chromatography (GPC) analysis and means a standard polystyrene equivalent value. The GPC analysis can be performed using tetrahydrofuran (THF) as a solution.

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

The component (A) is generally obtained by radical polymerization of a monomer using a radical polymerization initiator that generates radicals. Examples of radical polymerization initiators include persulfates such as azobisisobutyronitrile (AIBN), tert-butyl perbenzoate, benzoyl peroxide, lauroyl peroxide, potassium persulfate, cumene hydroperoxide, t-butyl hydroperoxide Dicumyl peroxide, di-t-butyl peroxide, 2,2′-azobis-2,4-dimethylvaleronitrile, t-butyl perisobutyrate, t-butyl perpivalate, hydrogen peroxide / ferrous salt, Examples thereof include persulfate / sodium acid sulfite, cumene hydroperoxide / ferrous salt, benzoyl peroxide / dimethylaniline, and the like. As the radical polymerization initiator, these may be used alone or in combination of two or more.

In the resin composition according to the embodiment of the present invention, the amount of the component (A) is preferably 10 to 70 parts by mass when the total amount of the components (A) and (B) is 100 parts by mass. When the amount is less than 10 parts by mass, low elasticity, which is an excellent feature of the component (A), tends not to be effectively expressed. Moreover, when it exceeds 70 mass parts, there exists a tendency for the adhesive strength with favorable metal foil not to be obtained, or for a flame retardance to fall.
Moreover, it is preferable that the compounding quantity of (A) component in the total amount of 100 mass parts of (A) component and (B) component is 15 mass parts or more from a viewpoint made especially low elasticity, and is 20 mass parts or more. More preferably, it is more preferably 30 parts by mass or more.
In addition, from the viewpoint of obtaining particularly good adhesive strength with the metal foil, the blending amount of the component (A) in the total amount of 100 parts by mass of the component (A) and the component (B) is preferably 60 parts by mass or less. The amount is more preferably 50 parts by mass or less, and further preferably 40 parts by mass or less.

[Thermosetting resin: component (B)]
As the component (B) used in the present invention, one having a phase separation structure when cured in combination with the component (A) is appropriately selected. The component (B) is not particularly limited. For example, epoxy resin, cyanate resin, bismaleimide resin, addition polymer of bismaleimide resin and diamine, phenol resin, resole resin, isocyanate resin, triallyl. Examples include isocyanurate resins, triallyl cyanurate resins, and vinyl group-containing polyolefin compounds. Among these, an epoxy resin or a cyanate resin is preferable in consideration of a balance of performance such as heat resistance and insulation.

When the resin composition according to the embodiment of the present invention is cured, the component (B) capable of forming a resin composite having a phase separation structure has (B-1) two or more epoxy groups in one molecule. Epoxy resin (hereinafter referred to as “component (B-1)”) and (B-2) a phenol resin having two or more hydroxyl groups in one molecule (hereinafter referred to as “component (B-2)”). It is preferable that it is a resin composition containing).

<Epoxy resin having two or more epoxy groups in one molecule: Component (B-1)>
The component (B) preferably contains the component (B-1).
The weight average molecular weight of the component (B-1) is preferably 200 to 1,000, and more preferably 300 to 900. When the weight average molecular weight is 200 or more, there is a tendency to form a phase separation structure with the component (A), and when it is 1,000 or less, a phase separation structure having a second phase having a relatively small domain tends to be formed. There is a tendency to exhibit low elasticity.
The epoxy equivalent of the component (B-1) is preferably 150 to 500, more preferably 150 to 450, and more preferably 150 to 300. When the epoxy equivalent of the epoxy resin is within the above range, the average domain size of the second phase tends not to be too large.

As the component (B-1), known components can be used. For example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, biphenyl type epoxy resin, phenol novolac type epoxy resin, cresol Novolac type epoxy resin, bisphenol A novolac type epoxy resin, phosphorus containing epoxy resin, naphthalene skeleton containing epoxy resin, aralkylene skeleton containing epoxy resin, phenol biphenyl aralkyl type epoxy resin, phenol salicylaldehyde novolak type epoxy resin, lower alkyl group substituted phenol salicyl Aldehyde novolac type epoxy resin, dicyclopentadiene skeleton-containing epoxy resin, polyfunctional glycidylamine type epoxy resin, polyfunctional alicyclic epoxy resin, Love Romo bisphenol A type epoxy resins. These 1 type (s) or 2 or more types can be used.
Commercially available products of component (B-1) include, for example, “N770” which is a phenol novolac type epoxy resin (trade name, manufactured by DIC Corporation), and “EPICLON 153” which is a tetrabromobisphenol A type epoxy resin (DIC stock). "NC-3000H" (product name) manufactured by Nippon Kayaku Co., Ltd., "Epicoat 1001" (product manufactured by Mitsubishi Chemical Corporation, product) Name), “ZX-1548” (trade name, manufactured by Toto Kasei Co., Ltd.) which is a phosphorus-containing epoxy resin, “EPICLON N-660” (trade name, manufactured by DIC Corporation), which is a cresol novolac type epoxy resin, and the like. It is done.

<Phenol resin having two or more hydroxyl groups in one molecule: Component (B-2)>
The component (B) preferably contains the component (B-2) from the viewpoint of ensuring adhesion strength with the metal foil.
As the component (B-2), known components can be used. For example, an aralkyl type phenol resin, a dicyclopentadiene type phenol resin, a salicylaldehyde type phenol resin, a copolymer of a benzaldehyde type phenol resin and an aralkyl type phenol resin. Type resin and novolac type phenol resin. These 1 type (s) or 2 or more types can be used.

As the component (B-2), polyhydric phenols such as phenol novolac are preferably used from the viewpoint of low water absorption.
As commercial products of the component (B-2), for example, “KA-1165” (trade name, manufactured by DIC Corporation) which is a cresol novolac resin, and “MEH-7851” (Maywa Kasei Co., Ltd.) which is a biphenyl novolac resin. For example, product name).

(B-2) The blending ratio of the component is usually determined so that the glass transition temperature becomes high. For example, when a phenol novolac resin is used as the component (B-2), the amount is preferably 0.5 to 1.5 equivalents relative to the epoxy group of the component (B-1). When the amount is 0.5 to 1.5 equivalents relative to the epoxy group, it is possible to prevent a decrease in adhesiveness with the outer layer copper and to prevent a decrease in glass transition temperature (Tg) and insulation.

<Curing agent for component (B)>
The resin composition of the present invention may contain a curing agent as component (B). (B) A well-known thing can be used as a hardening | curing agent of a component. Examples thereof include amine curing agents such as dicyandiamide, diaminodiphenylmethane, and diaminodiphenylsulfone, acid anhydride curing agents such as pyromellitic anhydride, trimellitic anhydride, and benzophenonetetracarboxylic acid, or a mixture thereof.
Various combinations of the component (B) and its curing agent in the present invention are conceivable depending on the component (A), curing conditions, curing agent, and curing catalyst used.
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. Taking an epoxy resin as an example, a sea-island structure that has a phase separation structure with an average domain size of about 1 μm to 10 μm by mixing and curing epoxy resins with different characteristics while controlling the catalyst type and skeleton structure, etc. Can be formed.

[Filler: (C) component]
The resin composition according to the embodiment of the present invention preferably contains one or more types of silica as the component (C). In the resin composition according to the embodiment of the present invention, as the component (C), (C-1) a filler subjected to a coupling treatment (hereinafter referred to as “(C-1) component”) is 1. It is preferable to contain more than one species. In the resin composition according to the embodiment of the present invention, (C-2) a filler not subjected to coupling treatment (hereinafter referred to as “(C-2) component”) is used as the (C) component. It is preferable to contain 1 or more types.

The component (C) used in the present invention preferably contains one or more components (C-1) and one or more components (C-2). By using the component (C-2) with and without the coupling treatment, the dispersibility of the filler in the resin composition can be controlled, and the characteristics of both the component (A) and the component (B) Can be fully expressed.
The average particle size of the component (C-1) is preferably 0.1 μm to 1.5 μm, more preferably 0.2 μm to 1.2 μm, and preferably 0.3 μm to 1.0 μm. Further preferred. When the average particle size of component (C-1) is 0.1 μm or more, fillers tend to disperse when varnished, and aggregation tends not to occur, and when it is 1.5 μm or less, varnishing occurs. There is a tendency that the precipitation of the component (C) hardly occurs.
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, and preferably 1.4 μm to 3.0 μm. Further preferred. When the average particle size of the component (C-2) is 1.0 μm or more, the fillers tend to disperse and tend not to agglomerate, and when it is 3.5 μm or less, the component (C) There is a tendency that sedimentation hardly occurs.
Here, the average particle diameter is a particle diameter at a point corresponding to a volume of 50% when a cumulative frequency distribution curve according to the particle diameter is obtained with the total volume of the particles being 100%, and a laser diffraction scattering method is used. It can be measured with a particle size distribution measuring device.

A well-known thing can be used for (C) component used for this invention. It is preferable to add an inorganic filler for the purpose of lowering the coefficient of thermal expansion and ensuring the flame retardancy. As inorganic fillers, silica, alumina, titanium oxide, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, calcium oxide, magnesium oxide, aluminum nitride, aluminum borate whisker, boron nitride, silicon carbide, etc. Can be mentioned. Among these, silica is more preferable because of its low dielectric constant and low linear expansion coefficient.
As the silica used in the present invention, various synthetic silicas synthesized by a wet method or a dry method, crushed silica obtained by crushing silica stone, fused silica once melted, and the like can be used.

In the present invention, the blending ratio of component (C) is preferably 5% by mass to 40% by mass, more preferably 10% by mass to 35% by mass, and more preferably 15% by mass, based on the solid content of the total resin composition. More preferably, the content is from 30% by mass to 30% by mass. The blending ratio of the component (C) is 40% by mass or less, so that the insulating resin does not become brittle and the low-elasticity and flexibility of the polymer acrylic polymer copolymerized with the crosslinkable functional group of the component (A) There is a tendency that sufficient sex is obtained. Moreover, when the compounding ratio of the component (C) is 5% by mass or more, the linear expansion coefficient tends to be low and sufficient heat resistance tends to be obtained.
In the present specification, the “solid content” is a non-volatile content excluding a volatile substance such as a solvent, and indicates a component that remains without volatilization when the resin composition is dried. Also includes liquid, syrupy and waxy. Here, room temperature in this specification indicates 25 ° C.

<Curing accelerator>
The resin composition may contain a curing accelerator. Although it does not specifically limit as a hardening accelerator, Amines or imidazoles are preferable. Examples of amines include dicyandiamide, diaminodiphenylethane, guanylurea and the like. Imidazoles include 2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-phenylimidazolium trimellitate, A benzimidazole etc. can be illustrated.
The blending amount of the curing accelerator can be determined, for example, according to the total amount of oxirane rings in the resin composition, but is generally 0.01 to 10 parts by mass in 100 parts by mass of the resin solid content of the resin composition. The mass is 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 according to the present invention includes, for example, a crosslinking agent, a flame retardant, a flow regulator, conductive particles, a coupling agent, a pigment, a leveling agent, an antifoaming agent, an ion trapping agent, and an antioxidant as necessary. Etc., and any known ones can be used.

<Solvent>
When manufacturing a prepreg etc. using the resin composition of this invention, you may make it the varnish in which the component of the resin composition of this invention melt | dissolved or disperse | distributed to the organic solvent.
Although it does not restrict | limit especially as an organic solvent used when making the resin composition of this invention a varnish, Ketone type, aromatic hydrocarbon type, ester type, amide type, alcohol type etc. are 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.
Examples of the ester solvent include methoxyethyl acetate, ethoxyethyl acetate, butoxyethyl acetate, and ethyl acetate.
Examples of the amide solvent include N-methylpyrrolidone, formamide, N-methylformamide, N, N-dimethylacetamide and the like.
Examples of alcohol solvents include methanol, ethanol, ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol, propylene glycol monomethyl ether, Examples include dipropylene glycol monomethyl ether, propylene glycol monopropyl ether, and dipropylene glycol monopropyl ether.
These organic solvents may be used alone or in combination of two or more.

[Phase separation structure]
The phase separation structure in the present invention is a sea-island structure, a continuous spherical structure, a composite dispersed phase structure, or a co-continuous phase structure, and the average domain size of the island phase is 1 μm to 10 μm, preferably 1.5 μm to 9 μm. More preferably, it is 2 μm to 8 μm.
When the average domain size of the island phase is less than 1 μm, good insulation reliability and high heat resistance of the thermosetting resin (B) tend not to be exhibited. Moreover, the surface area of the acrylic polymer having relatively weak adhesive strength with the metal foil is increased, and there is a tendency that good adhesive strength between the insulating layer and the metal foil cannot be obtained.
Moreover, when the average domain size of an island phase exceeds 10 micrometers, it exists in the tendency for the low elasticity which (A) component has to express easily.
Here, the average domain size of the island phase is the maximum of 70 or more island phases obtained from the cross-sectional structure obtained by an electron microscope after smoothing the cross section of the thermosetting resin composition with a microtome. The large and minimum widths were measured, and the average value was calculated.

Regarding the sea-island structure, continuous spherical structure, composite dispersed phase structure, and co-continuous phase structure (also referred to as continuous phase structure) as the phase separation structure, for example, “Polymer Alloy” page 325 (1993) The continuous spherical structure is described in detail, for example, in Keizo Yamanaka and Takashi Iniue, POLYMER, Vol. 30, pp. 662 (1989).

1 to 4 show model diagrams representing 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 can be obtained by controlling the catalyst species of the resin composition, the curing conditions such as the reaction temperature, or the compatibility between the components of the resin composition. In order to facilitate the occurrence of phase separation, for example, using an alkyl group-substituted epoxy resin to reduce the compatibility with the polymer acrylic polymer, or in the case of the same composition system, the curing temperature is increased. This can be achieved by slowing the curing rate by the choice of catalyst species.

FIG. 5 shows an electron micrograph showing a cross-sectional structure of an example of the resin composition having a sea-island structure obtained in this manner. As illustrated, the resin composition has a sea-island structure composed of an acrylic polymer phase and an epoxy resin-rich phase. 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 has excellent characteristics of both low elasticity of acrylic polymer, high insulation reliability of thermosetting resin, high heat resistance, and high adhesion to metal foil. Can do.

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 to the resin composition. Alternatively, in addition to the continuous spherical structure, a resin insulating layer having a fine co-continuous phase structure or a composite dispersed phase structure may be formed. FIG. 6 shows an electron micrograph showing a cross-sectional structure of an example of an insulating resin having a composite dispersed phase structure.

[Prepreg production method]
The prepreg of the present invention can be produced by impregnating a base material with the varnish of the above resin composition and drying it in the range of 80 ° C. to 180 ° C., for example.
Although a base material will not be restrict | limited especially if it is used when manufacturing a metal-clad laminated board, a printed circuit board, etc. Usually, fiber base materials, such as a woven fabric and a nonwoven fabric, are used. Examples of the material of the fiber base material include glass, alumina, asbestos, boron, silica alumina glass, silica glass, tyrano, silicon carbide, silicon nitride, zirconia, and other inorganic fibers, aramid, polyether ether ketone, polyether imide, Examples thereof include organic fibers such as polyethersulfone, carbon and cellulose, and mixed papers thereof. Among these, a glass cloth is preferable, a glass cloth having a thickness of 100 μm or less is more 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 that can be bent arbitrarily can be obtained, and the dimensional change accompanying temperature, moisture absorption, etc. in the manufacturing process is small, which is preferable.

It is preferable that 80% by mass or more of the organic solvent used in the prepreg varnish obtained is volatilized. If the organic solvent used in the varnish is volatilized by 80% by mass or more, the production method and drying conditions are not limited, and the drying temperature is, for example, 80 ° C. to 180 ° C., and the time is the gelation time of the varnish. It is set as appropriate in consideration of the above. The amount of impregnation of the varnish is preferably 30% by mass to 80% by mass with respect to the total amount of the varnish solid and the base material.

(Prepreg with metal foil)
The prepreg with a metal foil of the present invention is preferably formed by laminating the above prepreg and a metal foil.
The prepreg with a metal foil of the present invention is, for example, a metal foil laminated on one or both sides of the prepreg of the present invention, and usually at a temperature in the range of 130 ° C. to 250 ° C., preferably 150 ° C. to 230 ° C., usually 0.5 MPa to It can be produced by heating and pressing at a pressure in the range of 20 MPa, preferably 1 MPa to 8 MPa. The method of heating and pressing is not particularly limited, and for example, a multistage press, a multistage vacuum press, continuous molding, an autoclave molding machine, or the like can be used.
Moreover, it does not specifically limit as metal foil used when manufacturing the prepreg with metal foil of this invention, For example, copper foil and aluminum foil are generally used. The thickness of the metal foil is not particularly limited, and a thickness of 1 μm to 200 μm can be used. In addition, for example, nickel, nickel-phosphorus, nickel-tin alloy, nickel-iron alloy, lead, lead-tin alloy, etc. are used as intermediate layers, and 0.5 μm to 15 μm copper layer and 10 μm to 300 μm on both sides. A composite foil having a three-layer structure provided with a copper layer or a composite foil having a two-layer structure in which aluminum and copper foil are combined can be used.

(Laminated board)
The laminate of the present invention preferably has a plurality of the above prepregs.
The laminate of the present invention is formed, for example, by laminating the prepreg of the present invention and heating and pressing. The method of heating and pressing is not particularly limited, and for example, a multistage press, a multistage vacuum press, continuous molding, an autoclave molding machine, or the like can be used.

(Metal-clad laminate)
The metal-clad laminate of the present invention is preferably such that the laminate described above further has a metal foil.
The metal-clad laminate of the present invention is, for example, a metal foil laminated on one or both sides of the laminate of the present invention, and usually at a temperature in the range of 130 ° C. to 250 ° C., preferably 150 ° C. to 230 ° C., usually 0.5 MPa. It can be produced by heating and pressing at a pressure in the range of ˜20 MPa, preferably in the range of 1 MPa to 8 MPa. The method of heating and pressing is not particularly limited, and for example, a multistage press, a multistage vacuum press, continuous molding, an autoclave molding machine, or the like can be used.
Moreover, it does not specifically limit as metal foil used when manufacturing the metal-clad laminated board of this invention, For example, copper foil and aluminum foil are generally used. The thickness of the metal foil is not particularly limited, and a thickness of 1 μm to 200 μm can be used. In addition, for example, nickel, nickel-phosphorus, nickel-tin alloy, nickel-iron alloy, lead, lead-tin alloy, etc. are used as intermediate layers, and 0.5 μm to 15 μm copper layer and 10 μm to 300 μm on both sides. A composite foil having a three-layer structure provided with a copper layer or a composite foil having a two-layer structure in which aluminum and copper foil are combined can be used.

(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. It is preferable that the circuit is obtained by processing the laminate of the present invention.
The method for producing a printed circuit board of the present invention is not particularly limited, but circuit (wiring) processing is performed on the metal foil of the laminate (metal-clad laminate) of the present invention in which metal foil is provided on one or both sides. It can manufacture by giving.

Hereinafter, although an Example is shown and this invention is demonstrated concretely, this invention is not limited to these. In addition, the numerical value in the following example means the mass% unless there is particular notice.

[Examples 1 to 13]
Component (A), Component (B-1), Component (B-2), Component (C-1), Component (C-2) were blended in the blending amounts shown in Table 1, dissolved in methyl ethyl ketone, (D ) Component and coupling agent were blended according to Table 1 to obtain a resin composition varnish having a nonvolatile content of 40%.

[Comparative Examples 1 to 10]
Component (A), Component (B-1), Component (B-2), Component (C-1), Component (C-2) were blended in the amounts shown in Table 2, and dissolved in methyl ethyl ketone. D) was blended according to Table 2 to obtain a resin composition varnish having a nonvolatile content of 40%.

[Preparation of prepreg, copper foil with resin, metal-clad laminate]
(1) Preparation of prepreg After impregnating the varnish prepared in Examples 1 to 13 and Comparative Examples 1 to 10 into a glass cloth “1037” (trade name, manufactured by Asahi Schavel Co., Ltd.) having a thickness of 0.028 mm, the temperature is 140 ° C. For 10 minutes and dried to obtain a prepreg.
(2) Fabrication of resin-coated copper foil The varnishes produced in Examples 1 to 13 and Comparative Examples 1 to 10 were applied to an electrolytic copper foil “YGP-18” (trade name, manufactured by Nippon Electrolytic Co., Ltd.) having a thickness of 18 μm. It was coated and molded by a machine and dried with hot air at 140 ° C. for about 6 minutes to produce a resin-coated copper foil with a coating thickness of 50 μm.
(3) Preparation of metal-clad laminate (copper-clad laminate) Electrolytic copper foil “YGP-18” with a thickness of 18 μm on both sides of the prepreg prepared in (1), which was stacked four times (manufactured by Nippon Electrolytic Co., Ltd., product) Name) was laminated so that the adhesive surface was combined with the prepreg, and a double-sided copper-clad laminate was produced at 200 ° C. for 60 minutes under a 4 MPa vacuum press condition. Moreover, the copper foil with resin was stacked so that the resin surfaces face each other, and a double-sided copper-clad laminate was produced at 200 ° C. for 60 minutes under a 4 MPa vacuum press condition.

[Evaluation method for varnish, prepreg and metal-clad laminate]
(1) Varnish Properties The varnish properties were evaluated by receiving the prepared varnish in a transparent container, visually observing the appearance after 24 hours, and observing separation of varnish components and sediment. If the varnish hue was uniform, it was judged as not separated. Moreover, when the deposit of sediment was not visually confirmed on the bottom of the container, it was judged that there was no sediment. The results are shown in Tables 1 and 2.
(2) Tackiness of prepreg Tackiness of prepreg was evaluated by processing the prepared prepreg into 250 mm x 250 mm size, stacking 100 sheets, and putting them in a hermetically sealed bag at a temperature of 25 ° C and a humidity of 70%. The sample was put in a constant humidity environment, and the presence or absence of adhesion between the prepregs was observed. After 48 hours, when the prepreg disposed at the bottom and the prepreg in contact therewith were peeled off and each maintained the surface before being put in, it was determined that there was no adhesion and there was no problem with tackiness. The results are shown in Tables 1 and 2.
(3) Appearance of prepreg (presence of aggregates)
The evaluation of the appearance of the prepreg was observed with respect to the generation of aggregates using a 20 × magnifier. The results are shown in Tables 1 and 2.
(4) Storage elastic modulus The storage elastic modulus was evaluated by cutting a laminated board obtained by etching a copper clad laminated board prepared by superposing resin-coated copper foils so that the resin surfaces face each other into a width of 5 mm and a length of 30 mm. The storage elastic modulus was calculated using a mechanical viscoelasticity measuring device (manufactured by UBM Co., Ltd.). When the storage elastic modulus at 25 ° C. was 2.0 × 10 ⁹ Pa or less, it was judged that the stress relaxation effect could be exhibited. The results are shown in Tables 1 and 2.
(5) Tensile elongation The tensile elongation is evaluated by cutting a laminated sheet obtained by etching a copper-clad laminated sheet made of a resin-coated copper foil so that the resin faces face each other into a width of 10 mm and a length of 100 mm. The tensile elongation was calculated using a graph (manufactured by Shimadzu Corporation). If the tensile elongation at 25 ° C. was 3% or more, it was judged that the stress relaxation effect could be exhibited. The results are shown in Tables 1 and 2.
(6) Heat resistance A double-sided copper clad laminate prepared from four prepregs was cut into a 50 mm square to obtain a test piece. The test piece was immersed in a solder bath at 260 ° C., and the time elapsed from that point to the point when the swelling of the test piece was visually observed was measured. The elapsed time was measured up 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 adhesion of metal foil to substrate A copper foil of a double-sided copper clad laminate prepared from four prepregs was partially etched to form a 3 mm wide copper foil line. Next, the load when the copper foil line was peeled off at a speed of 50 mm / min in the direction of 90 ° with respect to the bonding surface was measured, and the copper foil peeling strength was obtained. When the copper foil peel strength was 0.5 kN / m or more as a result, it was judged that the adhesion to the metal foil was sufficient. Shown in Tables 1 and 2.
(8) Phase structure observation test The average domain size of the island phase was obtained by smoothing the cross section of the resin insulation layer of the copper-clad laminate prepared by stacking the resin-coated copper foils so that the resin surfaces face each other with a microtome. The maximum width and the minimum width were measured for 70 or more island phases from the cross-sectional structure obtained by etching with a salt solution and obtained by an electron microscope, and the average value was calculated. The results are shown in Tables 1 and 2.
(9) Electrical insulation reliability Electrical insulation reliability is 400 holes for each sample using a test pattern in which a double-sided copper-clad laminate made from four prepregs is processed so that the through-hole hole wall spacing is 350 μm. The insulation resistance was measured over time. The measurement was performed by applying 100 V in an 85 ° C./85% RH atmosphere, and measuring the time until conduction breakdown occurred. The measurement time was up 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: Product name “KH-CT-865”, manufactured by Hitachi Chemical Co., Ltd. (weight average molecular weight: Mw = 45 × 10 ⁴ to 65 × 10 ⁴ , as a compound represented by formula (1) Acrylic polymer containing a methacrylic acid ester having a cycloalkyl group having 5 to 10 carbon atoms and no nitrile group in the structure)
* 2: Trade name “HTR-860P-3”, manufactured by Nagase ChemteX Corporation (weight average molecular weight: Mw = 80 × 10 ⁴ , acrylic polymer containing no nitrile group in the structure)
* 3: Product name “HAN5-M90S”, manufactured by Negami Kogyo Co., Ltd. (weight average molecular weight: Mw = 90 × 10 ⁴ , acrylic polymer containing nitrile group in the structure)
* 4: Product name “N770”, manufactured by DIC Corporation (phenol novolac type epoxy resin)
* 5: Trade name “EPICLON 153”, manufactured by DIC Corporation (tetrabromobisphenol A type epoxy resin)
* 6: Product name “NC-3000H”, manufactured by Nippon Kayaku Co., Ltd. (biphenylaralkyl 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 resin)
* 9: Product name “SC-2050KC”, manufactured by Admatech Co., Ltd. (fused spherical silica, silane coupling treatment, average particle size 0.5 μm)
* 10: Product name “HK-001”, manufactured by Kawai Lime Co., Ltd. (aluminum hydroxide, average particle size 4.0 μm)
* 11: Product name “F05-12”, manufactured by Fukushima Ceramics Co., Ltd. (crushed silica, average particle size 2.5 μm)
* 12: Product name “F05-30”, manufactured by Fukushima Ceramics Co., Ltd. (crushed silica, average particle size 4.2 μm)
* 13: Trade name “2PZ”, manufactured by Shikoku Chemicals Co., Ltd. (2-phenylimidazole)
* 14: Product name “A-187”, manufactured by Toray Dow Corning Co., Ltd. (silane coupling agent)

As is clear from Table 1, the examples of the present invention are excellent in all of low elasticity, heat resistance, adhesion to metal foil, and insulation reliability. On the other hand, none of the comparative examples is excellent in all of low elasticity, heat resistance, adhesion to metal foil, and insulation reliability.

According to the resin composition, prepreg, prepreg with metal foil, laminate, metal-clad laminate and printed circuit board of the present invention, it has low elasticity, high insulation reliability, high heat resistance, and high adhesion to metal foil. .

Claims

(A) A first phase containing an acrylic polymer and (B) a second phase as an island phase containing a thermosetting resin form a phase separation structure, and the average domain size of the island phase is 1 μm to 10 μm (C) A prepreg impregnated with a resin composition containing a filler.
The prepreg according to claim 1, wherein the blending amount of the (A) acrylic polymer is 10 to 70 parts by mass when the total amount of the (A) acrylic polymer and the (B) thermosetting resin is 100 parts by mass. .
The prepreg according to claim 1 or 2, comprising (C-1) a coupling-treated filler as the (C) filler.
The prepreg according to any one of claims 1 to 3, wherein (C-2) a filler not subjected to coupling treatment is contained as the (C) filler.
The prepreg according to any one of claims 1 to 4, wherein the (B) thermosetting resin contains (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 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 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 filler (C).
The prepreg according to any one of claims 1 to 11, wherein the volume average particle size of the (C-2) filler is 1.0 µm to 3.5 µm.
A prepreg with a metal foil obtained by laminating the prepreg according to any one of claims 1 to 12 and a metal foil.
A laminate having a plurality of the prepregs according to any one of claims 1 to 12.
A metal-clad laminate in which the laminate according to claim 14 further comprises a metal foil.
A printed circuit board, wherein the laminate according to claim 14 further comprises a circuit.