JP6843367B2 - Resin sheet, printed wiring board and board with built-in parts - Google Patents

Description

The present invention relates to a resin sheet, a printed wiring board, and a component-embedded substrate.

In recent years, electronic devices have become smaller and more sophisticated. Therefore, the development of a SiP (System-in-Package) substrate on which modules having various functions are mounted has been promoted. Further, in order to save space for mounted components, a component-embedded substrate in which components such as an IC and a capacitor are embedded inside a resin substrate is currently attracting attention.

For various parts, an arbitrary cavity is formed on the core resin substrate or copper substrate, the parts are placed in the cavity, and then the thermosetting resin is thermocompression bonded to the cavity to incorporate the parts. The thermosetting resin is required to have a cavity embedding property and adhesion to a component.

Various efforts have been made in response to this. For example, Patent Document 1 describes the parameters after curing required for the embedded resin with respect to the configuration of the electronic component module and the component-embedded substrate incorporating the electronic component module.

Patent Document 2 describes a resin composition for liquid encapsulation using a liquid epoxy resin in order to exhibit fluidity.

Patent Document 3 describes that, for a resin sheet for embedding a part, the crack property between the part and the resin is improved by improving the value of the coefficient of thermal expansion α2 at 150 to 250 ° C.

Japanese Unexamined Patent Publication No. 2008-159973 International Publication No. 2012/157665 Pamphlet Japanese Unexamined Patent Publication No. 2016-8279

Regarding Patent Document 1, although there is a description of parameters required for a resin sheet, there is no description of examples, and it is unclear about the optimum material.

Regarding Patent Document 2, a liquid epoxy is used as a liquid component, but the glass transition temperature remains at about 230 ° C.

Regarding Patent Document 3, the coefficient of thermal expansion α2 is improved to improve the cracks with the parts during heat, but there is no description about the coefficient of thermal expansion and stress.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a good embedding property in a cavity and a good adhesiveness to a component in order to prepare a component-embedded substrate, and to transfer a cured product to glass. It is to obtain a resin sheet having a high temperature, and to provide a printed wiring board and a component-embedded substrate using the resin sheet.

That is, the present invention is excellent in flexibility in the B stage state, low viscosity at the time of melting, and excellent component embedding moldability when used as an insulating layer in a printed wiring board material and a material for embedding a component in a component-embedded substrate. It is an object of the present invention to obtain a resin sheet having excellent adhesion to a component in the C stage state and a high glass transition temperature when completely cured, and to provide a printed wiring board and a component-embedded substrate using the resin sheet.

As a result of diligent studies, the present inventors have obtained an outer layer, which is one of the groups selected from the group consisting of a polymer film, a metal foil, and a metal film, and an insulating layer composed of a resin composition laminated on the outer layer. The resin composition contains a bifunctional cyanate ester compound (A), an inorganic filler (B) and a silicone composite powder (C), and the resin composition is brought into a C stage state. When the Young ratio of the cured product is E (GPa), the thermal expansion coefficient is α (ppm / K), and the thermal stress coefficient obtained by multiplying the Young ratio E and the thermal expansion coefficient α is X, the thermal stress We have found that the above-mentioned problems can be solved by a resin sheet having a coefficient X of 150 to 204 GPa · ppm / K, and arrived at the present invention.

That is, the present invention is as follows.
[1]
A resin sheet comprising an outer layer, which is one of any kind, selected from the group consisting of a polymer film, a metal foil, and a metal film, and an insulating layer composed of a resin composition laminated on the outer layer. The young ratio of the cured product in which the composition contains the bifunctional cyanate ester compound (A), the inorganic filler (B) and the silicone composite powder (C) and the resin composition is cured to the C stage state is E. (GPa), when the thermal expansion coefficient is α (ppm / K) and the thermal stress coefficient obtained by multiplying the Young's ratio E and the thermal expansion coefficient α is X, the value of the thermal stress coefficient X is 150 to 204 GPa · ppm. A resin sheet that is / K.
[2]
The resin sheet according to [1], wherein the resin composition further contains the maleimide compound (D).
[3]
The resin sheet according to [1] or [2], wherein the resin composition further contains the epoxy compound (E).
[4]
The resin sheet according to any one of [1] to [3], wherein the resin composition further contains the polyfunctional cyanate ester compound (F).
[5]
Any of claims [1] to [4], wherein the content of the bifunctional cyanate ester compound (A) in the resin composition is 5 parts by mass or more with respect to 100 parts by mass of the resin solid content in the resin composition. The resin sheet described in item 1.
[6]
The item according to any one of [1] to [5], wherein the content of the inorganic filler (B) in the resin composition is 200 parts by mass or more with respect to 100 parts by mass of the resin solid content in the resin composition. Resin sheet.
[7]
The item according to any one of [1] to [6], wherein the content of the silicone composite powder (C) in the resin composition is 15 parts by mass or more with respect to 100 parts by mass of the resin solid content in the resin composition. Resin sheet.
[8]
The resin sheet according to any one of [1] to [7], wherein the metal foil or metal film is a copper or aluminum foil or film.
[9]
The resin sheet according to any one of [1] to [7], wherein the polymer film is any one selected from the group consisting of polyester, polyimide and polyamide.
[10]
The resin sheet according to any one of [1] to [9], wherein the insulating layer made of the resin composition is in the B stage state.
[11]
The resin sheet according to [10], wherein the minimum melt viscosity of the insulating layer in the B stage state is 1,000 Pa · s or less.
[12]
A printed wiring board containing the resin sheet according to [1] to [11].
[13]
A component-embedded substrate containing the resin sheet according to [1] to [11].

The resin sheet of the present invention exerts at least, preferably all of the following effects (1) to (4).
(1) The resin sheet in the B stage state is excellent in flexibility.
(2) The melt viscosity of the resin is low, and the moldability and component embedding property are excellent.
(3) Excellent adhesion between the cured resin product and parts in the C stage state.
(4) Has a high glass transition temperature.
In the present specification, the B stage state refers to a state in which the resin composition is in a semi-cured state and can be melt-molded by heating and pressurizing, and the C stage state refers to a state in which the resin composition is completely cured. Point to.

One aspect of the present invention is a resin containing an outer layer, which is one of a group selected from the group consisting of a polymer film, a metal foil, and a metal film, and an insulating layer composed of a resin composition laminated on the outer layer. In the sheet, the resin composition contained a bifunctional cyanate ester compound (A), an inorganic filler (B) and a silicone composite powder (C), and the resin composition was cured to a C stage state. When the Young ratio of the cured product is E (GPa), the thermal expansion coefficient is α (ppm / K), and the thermal stress coefficient obtained by multiplying the Young ratio E and the thermal expansion coefficient α is X, the thermal stress coefficient X is It is a resin sheet having a value of 150 to 204 GPa · ppm / K or less.
By setting the value of the thermal stress coefficient X in such a range, the adhesiveness between the cured product obtained by curing the resin composition to the C stage state and the component is good, and the cured product has low thermal expansion and heat resistance. Can be made excellent.

[I-1. Bifunctional cyanate ester compound (A)]
The bifunctional cyanate ester compound (A) used in the present invention is a compound having a cyanato group (cyanic acid ester group), and is not particularly limited as long as the number of functional groups is two.
The bifunctional cyanate ester compound (A) can reduce the melt viscosity in the B stage state and improve the part embedding moldability.
Specifically, the bifunctional cyanate ester compound (A) is a bisphenol A type cyanate ester compound, a bisphenol AP type cyanate ester compound, a bisphenol AF type cyanate ester compound, a bisphenol B type cyanate ester compound, or a bisphenol BP type. Cyanic acid ester compound, bisphenol C type cyanate ester compound, bisphenol E type cyanic acid ester compound, bisphenol F type cyanic acid ester compound, bisphenol G type cyanate ester compound, bisphenol M type cyanic acid ester compound, bisphenol S type cyanic acid Examples thereof include esters, bisphenol P-type cyanate ester compounds, bisphenol PH-type cyanate ester compounds, bisphenol TMC-type cyanate ester compounds, bisphenol Z-type cyanate ester compounds, diallyl bisphenol A-type cyanate ester, and the like. The bifunctional cyanate ester compound (A) can be used alone or in admixture of two or more.

These bifunctional cyanate ester compounds (A) improve the flexibility in the B stage state and reduce the minimum melt viscosity in the resin sheet of the present invention to improve moldability and embedding property. It is possible to impart excellent properties such as chemical resistance, high glass transition temperature, and low thermal expansion property in the C stage state.
Further, the bifunctional cyanate ester compound (A) is more preferable if it is liquid at room temperature because it exhibits the above-mentioned characteristics.
As described in the above example, in the present specification, the cyanate ester compound (A) having a structure obtained by cyanating (cyanic acid esterification) a certain resin or compound is referred to as the name of the resin or compound. It may be expressed with the description of "~ type cyanate ester compound".

The diallyl bisphenol A type cyanate ester compound refers to a compound represented by the formula (1).

The content of the bifunctional cyanate ester compound (A) in the resin composition in the present invention is not particularly limited, but from the viewpoint of the flexibility of the resin in the B stage state, the content of the bifunctional cyanate ester compound (A) is relative to 100 parts by mass of the resin solid content of the resin composition. 5, 5 parts by mass or more is preferable, and 10 parts by mass or more is particularly preferable. Although not particularly limited, it is preferably 30 parts by mass or less from the viewpoint of suppressing tackiness.

[I-2. Inorganic filler (B)]
The inorganic filler (B) used in the present invention is not particularly limited as long as it is used in the art, and examples thereof include silica (for example, natural silica, molten silica, amorphous silica, hollow silica, etc.) and aluminum. Compounds (eg boehmite, aluminum hydroxide, alumina, etc.), magnesium compounds (eg magnesium oxide, magnesium hydroxide, etc.), calcium compounds (eg calcium carbonate, etc.), molybdenum compounds (eg molybdenum oxide, zinc molybdate, etc.), talc (eg, molybdenum oxide, zinc molybdenate, etc.) For example, natural talc, fired talc, etc.), mica (mica), glass (for example, short fibrous glass, spherical glass, fine powder glass (for example, E glass, T glass, D glass, etc.), etc.), titanium (for example, titanium oxide, titanium). Examples thereof include barium acid acid) and zirconia compounds (for example, zirconium oxide). As the inorganic filler (B), one kind or two or more kinds may be appropriately mixed and used.

Among these, one or more selected from the group consisting of silica, aluminum hydroxide, alumina, boehmite, magnesium oxide and magnesium hydroxide is preferable.

In particular, silica is preferable from the viewpoint of low thermal expansion, and molten silica is particularly preferable. Specific examples of the molten silica include SFP-130MC manufactured by Denki Kagaku Kogyo Co., Ltd., SC2050-MB, SC2500-SQ, SC4500-SQ manufactured by Admatex Co., Ltd., and the like.

The average particle size of the inorganic filler (B) is not limited, but is preferably 0.01 to 5.0 μm, more preferably 0.2 to 2.0 μm, from the viewpoint of improving the manufacturability of the resin sheet. preferable. In the present specification, the "average particle size" of the inorganic filler (B) means the median diameter of the inorganic filler (B). Here, the median diameter refers to the number or mass of particles on the larger particle size side and the number or mass on the smaller particle size side when the particle size distribution of the powder is divided into two based on a certain particle size. The mass means a particle size such that each occupies 50% of the total powder. The average particle diameter (median diameter) of the inorganic filler (B) is measured by a wet laser diffraction / scattering method.

The content of the inorganic filler (B) in the resin composition in the present invention is from the viewpoint of obtaining adhesion to parts by reducing the coefficient of thermal expansion α of the cured product and the coefficient of thermal stress X. It is preferably 200 parts by mass or more, and preferably 250 parts by mass or more, based on 100 parts by mass of the resin solid content of the resin composition. Further, from the viewpoint of exhibiting the minimum moldability, the content is preferably 1000 parts by mass or less.

[I-3. Silicone composite powder (C)]
The silicone composite powder is a fine powder made of an addition polymer of vinyl group-containing dimethylpolysiloxane and methylhydrogenpolysiloxane, whose surface is coated with a silicone resin to improve dispersibility. From the viewpoint of dispersibility, the silicone composite powder (C) preferably has an average particle size in the range of 1 to 15 μm.

As the silicone composite powder (C), in addition to being produced as described above, a commercially available product can also be used. Examples of commercially available products include KMP-600, KMP-601, KMP-602, KMP-605, and X-52-7030 manufactured by Shin-Etsu Chemical Co., Ltd.

The silicone composite powder (C) is a resin solid of a resin composition from the viewpoint of obtaining adhesion to parts by reducing Young's modulus E and thermal expansion coefficient α of the cured product and reducing thermal stress coefficient X. It is preferably contained in an amount of 15 parts by mass or more with respect to 100 parts by mass. From the viewpoint of obtaining good embedding property, it is preferably 40 parts by mass or less.

（式中、Ｒ^２は各々独立に、水素原子又はメチル基を表す。ｎ^２は平均値として１〜１０の範囲である。）
なお、これらマレイミド化合物（Ｄ）は、プレポリマー、又はマレイミド化合物とアミン化合物のプレポリマーなどの形で用いることができる。マレイミド化合物（Ｄ）及びそのプレポリマーは、１種もしくは２種以上を適宜混合して使用することも可能である。 [I-4. Maleimide compound (D)]
In the present invention, it is preferable to use the maleimide compound (D) when improving the hygroscopic heat resistance of the insulating layer of the resin sheet. The maleimide compound (D) used is not particularly limited as long as it is a compound having a maleimide group, and specifically, bis (4-maleimidephenyl) methane and 2,2-bis {4- (4-maleimide). Phenoxy) -phenyl} propane, bis (3,5-dimethyl-4-maleimidephenyl) methane, bis (3-ethyl-5-methyl-4-maleimidephenyl) methane, bis (3,5-diethyl-4-maleimide) Examples thereof include phenyl) methane, tris (4-maleimidephenyl) methane, long-chain alkylbismaleimide, and a maleimide compound represented by the formula (2).
Among these, the maleimide compound represented by the formula (2) is preferable from the viewpoint of moisture absorption heat resistance and flame resistance. Commercially available products can be used for the compound, and examples thereof include BMI-2300 manufactured by KI Kasei Co., Ltd.

(In the formula, R ² independently represents a hydrogen atom or a methyl group. N ² has an average value in the range of 1 to 10.)
The maleimide compound (D) can be used in the form of a prepolymer, a prepolymer of a maleimide compound and an amine compound, and the like. The maleimide compound (D) and its prepolymer can be used alone or in admixture of two or more.

[I-5. Epoxy compound (E)]
The epoxy compound (E) used in the present invention has a structure corresponding to each of the properties, for example, when moisture absorption and heat resistance, adhesion to a substrate / copper foil, insulation, electrical properties, etc. are required for a resin sheet. Can be used, and can be preferably used.
The epoxy compound (E) is not particularly limited as long as it is an organic compound having at least one epoxy group, and for example, a biphenyl aralkyl type epoxy compound (epoxy group-containing biphenyl aralkyl resin) and a naphthalene type epoxy compound (naphthalene skeleton) are used. Epoxy group-containing compound having: naphthalene bifunctional epoxy compound), bisnaphthalene type epoxy compound (epoxy group-containing compound having a bisnaphthalene skeleton: naphthalene tetrafunctional epoxy compound), aromatic hydrocarbon formaldehyde type epoxy compound (epoxy group containing) Aromatic hydrocarbon formaldehyde resin), anthraquinone type epoxy compound (epoxy group-containing compound having an anthraquinone skeleton), naphthol aralkyl type epoxy compound (epoxy group-containing naphthol aralkyl resin), zylock type epoxy compound (epoxy group-containing zyrock resin), bisphenol A-type epoxy resin, bisphenol F-type epoki resin, bisphenol A novolak-type epoxy resin, trifunctional phenol-type epoxy compound (epoxy group-containing compound having a trifunctional phenol skeleton), tetrafunctional phenol-type epoxy compound (having a tetrafunctional phenol skeleton) Epoxy group-containing compound), biphenyl type epoxy resin (epoxy group-containing compound having a biphenyl skeleton), aralkylnovolac type epoxy resin, triazine skeleton epoxy compound (triazine skeleton-containing epoxy resin) alicyclic epoxy resin, polyol type epoxy resin, glycidyl Examples thereof include a compound obtained by epoxidizing a double bond of a double bond-containing compound such as amine, glycidyl ester, and butadiene, and a compound obtained by reacting a hydroxyl group-containing silicone resin with epichlorohydrin.
These epoxy compounds (E) can be used alone or in admixture of two or more, depending on the properties required for the resin sheet.

As described in the above example, in the present specification, an epoxy compound having a structure obtained by epoxidizing a certain resin or compound is described as "-type epoxy compound" in the name of the resin or compound. May be expressed as.

Among these, the epoxy compound (E) includes a biphenylaralkyl type epoxy compound, a naphthalene type epoxy compound, a bisnaphthalene type epoxy compound, and an aromatic from the viewpoint of adhesion between the insulating layer and the plated conductor layer and flame retardancy. Carbide formaldehyde type epoxy compound (preferably, aromatic hydrocarbon formaldehyde resin obtained by polymerizing aromatic hydrocarbons such as benzene, toluene and xylenol with formaldehyde, and hydroxyl group-containing aromatic carbonic acid such as phenol and xylenol. Compounds that have been modified with hydrogen and further epoxidized with the hydroxyl groups, compounds with the hydroxyl groups of the aromatic hydrocarbon formaldehyde resin obtained by polymerizing hydroxyl group-containing aromatic hydrocarbons such as phenol and xylenol with formaldehyde, and the like. ), Anthraquinone type epoxy compound, naphthol aralkyl type epoxy compound, and Zyroc type epoxy compound, one or more selected from the group.

As the epoxy compound (E), ready-made products having various structures are commercially available, and they can be appropriately obtained and used. Further, the epoxy compound (E) may be produced by using various known production methods. Examples of such a production method include a method of obtaining or synthesizing a hydroxyl group-containing compound having a desired skeleton, modifying the hydroxyl group by a known method, and epoxidizing (introducing an epoxy group).

[I-6. Polyfunctional cyanate ester compound (F)]
In the present invention, the polyfunctional cyanate ester compound (F) is preferably used when improving the chemical resistance, high glass transition temperature, and low thermal expansion of the insulating layer of the resin sheet (a polyfunctional cyanate ester compound (F). The F) is not particularly limited as long as it is a compound having three or more cyanato groups (cyanic acid ester groups). Specifically, naphthol aralkyl type cyanate ester compound (cyanato group-containing naphthol aralkyl resin), aromatic hydrocarbon formaldehyde type cyanate ester compound (cyanato group-containing aromatic hydrocarbon formaldehyde resin), biphenyl aralkyl type cyanate ester compound. (Cyanato group-containing biphenyl aralkyl resin), novolak-type cyanate ester compound (cyanato group-containing novolak resin), and the like, and the polyfunctional cyanate ester compound (F) is appropriately mixed with one or more. It is also possible to use it.

（式中、Ｒ^３は各々独立に水素原子又はメチル基を表し、中でも水素原子が好ましい。ｎ^３は１以上の整数を示す。） As the naphthol aralkyl type cyanate ester compound, the compound represented by the formula (3) is preferable.

(In the formula, R ³ independently represents a hydrogen atom or a methyl group, and among them, a hydrogen atom is preferable. N ³ represents an integer of 1 or more.)

（式中、Ｒ^４は水素原子又はメチル基を表し、中でも水素原子が好ましい。ｎ^４は１以上の整数を示す。） As the novolak type cyanate ester compound, the compound represented by the formula (4) is preferable.

(In the formula, R ⁴ represents a hydrogen atom or a methyl group, and among them, a hydrogen atom is preferable. N ⁴ represents an integer of 1 or more.)

（式中、Ｒ^５は水素原子又はメチル基を表し、中でも水素原子が好ましい。ｎ^５は１以上の整数を示す。） As the biphenyl aralkyl type cyanate ester compound, the compound represented by the formula (5) is preferable.

(In the formula, R ⁵ represents a hydrogen atom or a methyl group, and among them, a hydrogen atom is preferable. N ⁵ represents an integer of 1 or more.)

As the polyfunctional cyanate ester compound (F), ready-made products having various structures are commercially available, and they can be appropriately obtained and used. Further, the cyanate ester compound (F) may be produced by using various known production methods. Examples of such a production method include a method of obtaining or synthesizing a hydroxyl group-containing compound having a desired skeleton and modifying the hydroxyl group by a known method to form cyanato. Examples of the method for cyanating a hydroxyl group include the methods described in Ian Hamerton, “Chemistry and Technology of Cynate Ester Resins,” Blackie Academic & Professional.

[I-7. Other ingredients]
In the resin sheet of the present invention, a bifunctional cyanate ester compound (A), an inorganic filler (B), a silicone composite powder (C), a maleimide compound (D), an epoxy compound (E), and a polyfunctional cyanate ester compound In addition to (F), it may contain one or more other components.

For example, the resin composition used for the insulating layer of the present invention may contain a silane coupling agent for the purpose of improving moisture absorption and heat resistance. The silane coupling agent is not limited as long as it is a silane coupling agent generally used for surface treatment of inorganic substances. Specific examples include aminosilane-based silane coupling agents (for example, γ-aminopropyltriethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, etc.) and epoxysilane-based silane coupling agents (for example, γ). -Glysidoxypropyltrimethoxysilane, etc.), Vinylsilane-based silane coupling agents (eg, γ-methacryloxipropyltrimethoxysilane, etc.), Cationic silane-based silane coupling agents (eg, N-β- (N-vinylbenzyl, etc.) Aminoethyl) -γ-aminopropyltrimethoxysilane hydrochloride, etc.), phenylsilane-based silane coupling agent, etc. can be mentioned. One of these silane coupling agents may be used alone, or two or more thereof may be used in any combination and ratio.

When a silane coupling agent is used, its content is not limited, but from the viewpoint of improving moisture absorption and heat resistance, the ratio of the silane coupling agent to the inorganic filler (B) is 0.05. It is preferably ~ 5% by mass, more preferably 0.1 to 3% by mass. When two or more kinds of silane coupling agents are used in combination, it is preferable that the total amount of these silane coupling agents satisfies the above ratio.

Further, the resin composition used for the insulating layer of the present invention may contain a wetting dispersant for the purpose of improving the manufacturability of the resin sheet. The wet dispersant is not limited as long as it is a wet dispersant generally used for paints and the like. Specific examples thereof include Disperbyk-110, -111, -180, -161, BYK-W996, -W9010, and -W903 manufactured by Big Chemy Japan Co., Ltd. These wet dispersants may be used alone or in combination of two or more in any combination and ratio.

When a wet dispersant is used, its content in the resin composition is not limited, but from the viewpoint of improving the manufacturability of the resin sheet, the ratio of the wet dispersant to the inorganic filler (B) Is preferably 0.1 to 5% by mass, more preferably 0.5 to 3% by mass. When two or more kinds of wet dispersants are used in combination, it is preferable that the total amount thereof satisfies the above ratio.

Further, the resin composition used for the insulating layer of the present invention may contain a curing accelerator for the purpose of adjusting the curing rate or the like. The curing accelerator is known as a curing accelerator such as an epoxy compound or a cyanate ester compound, and is not particularly limited as long as it is generally used. Specific examples include organic metal salts containing metals such as copper, zinc, cobalt, nickel and manganese (for example, zinc octylate, cobalt naphthenate, nickel octylate, manganese octylate and the like), imidazoles and derivatives thereof (for example, 2). -Ethyl-4-methylimidazole, 1-benzyl-2-phenylimidazole, 2,4,5-triphenylimidazole, etc.), tertiary amines (eg, triethylamine, tributylamine, etc.) and the like can be mentioned. These curing accelerators may be used alone or in combination of two or more in any combination and ratio.

When a curing accelerator is used, its content in the resin composition is not limited, but from the viewpoint of obtaining a high glass transition temperature, the curing accelerator is used with respect to 100 parts by mass of the resin solid content of the resin composition. The ratio of the above is preferably 0.01 to 5 parts by mass, and more preferably 0.05 to 4 parts by mass. When two or more kinds of curing accelerators are used in combination, it is preferable that the total amount thereof satisfies the above ratio.

Further, the resin composition used for the insulating layer of the present invention may contain various other polymer compounds and / or flame-retardant compounds as long as the desired properties are not impaired. The polymer compound and the flame-retardant compound are not limited as long as they are generally used. Examples of the polymer compound include various thermosetting resins and thermoplastic resins, their oligomers, and elastomers. Examples of flame-retardant compounds include phosphorus-containing compounds (for example, phosphoric acid ester, melamine phosphate, phosphorus-containing epoxy resin, etc.), nitrogen-containing compounds (for example, melamine, benzoguanamine, etc.), oxazine ring-containing compounds, silicone-based compounds, and the like. Can be mentioned. One of these polymer compounds and / or flame-retardant compounds may be used alone, or two or more thereof may be used in any combination and ratio.

Further, the resin composition used for the insulating layer of the present invention may contain various additives for various purposes as long as the desired characteristics are not impaired. Examples of additives include UV absorbers, antioxidants, photopolymerization initiators, optical brighteners, photosensitizers, dyes, pigments, thickeners, lubricants, defoamers, dispersants, leveling agents, etc. Examples include brighteners. One of these additives may be used alone, or two or more of these additives may be used in any combination and ratio.

[I-8. Resin composition]
The resin composition used for the insulating layer of the present invention contains one or more other components in addition to the bifunctional cyanate ester compound (A), the inorganic filler (B), and the silicone composite powder (C). Prepared by mixing. If necessary, it may be in the form of a solution (varnish) in which these components are dissolved in an organic solvent. Such a solution can be suitably used as a varnish for producing the resin sheet of the present invention described later. The organic solvent is not limited as long as it can suitably dissolve or disperse each of the above-mentioned components and does not impair the desired effect of the resin composition of the present invention. Specific examples include alcohols (methanol, ethanol, propanol, etc.), ketones (eg, acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.), amides (eg, dimethylacetamide, dimethylformamide, etc.), aromatic hydrocarbons (eg, toluene). , Xylene, etc.) and the like. One of these organic solvents may be used alone, or two or more of these organic solvents may be used in any combination and ratio.

[II-1. Resin sheet]
The resin sheet of the present invention is obtained by laminating an insulating layer made of the above-mentioned resin composition on an outer layer.

The outer layer is selected from a polymer film, a metal foil and a metal film.
Specific examples of the polymer film include polyesters such as polyvinyl chloride, polyvinylidene chloride, polybutene, polybutadiene, polyurethane, ethylene-vinyl oxide copolymer, polyethylene terephthalate, polyethylene naphthalate and polybutylene terephthalate, polyethylene, polypropylene and ethylene. Examples thereof include a film containing at least one resin selected from the group consisting of a propylene copolymer, polymethylpentene, polyimide and polyamide, and a release film in which a release agent is applied to the surface of these films. Among these, polyester, polyimide, and polyamide are particularly preferable, and among them, polyethylene terephthalate, which is a kind of polyester, is particularly preferable.
The thickness of the polymer film is not particularly limited, and may be, for example, 0.002 to 0.1 mm.
Specific examples of the metal foil and the metal film include foils or films made of metals such as copper and aluminum. Among them, copper foils or copper films are preferable, and electrolytic copper foils, rolled copper foils, copper alloy films and the like are particularly preferable. Can be used for. The metal foil or the metal film may be subjected to a known surface treatment such as nickel treatment or cobalt treatment. The thickness of the metal foil or the metal film can be appropriately adjusted depending on the intended use, but is preferably in the range of 5 to 70 μm, for example.

The resin sheet of the present invention is produced by forming an insulating layer made of the above-mentioned resin composition on the above-mentioned outer layer, but the method is not particularly limited. As an example, a solution (varnish) in which a resin composition is dissolved or dispersed in an organic solvent is applied to the surface of the above-mentioned outer layer, dried under heating and / or reduced pressure, and the solvent is removed to obtain the resin composition. Examples thereof include a method of solidifying and forming an insulating layer. The drying conditions are not particularly limited, but the drying is performed so that the content ratio of the organic solvent to the insulating layer is usually 10 parts by mass or less, preferably 5 parts by mass or less, based on the total amount of the insulating layer. The conditions for achieving such drying vary depending on the amount of the organic solvent in the varnish. For example, in the case of a varnish containing 30 to 60 parts by mass of an organic solvent, it is dried for about 3 to 10 minutes under heating conditions of 50 to 160 ° C. Just let me do it. The thickness of the resin composition layer in the resin sheet of the present invention is not limited, but from the viewpoint of better removing light volatile components when the resin composition layer is dried, and from the viewpoint of more effectively and surely performing the function as a resin sheet. Therefore, a range of 0.1 to 500 μm is preferable.

The resin sheet of the present invention can be used as a build-up material for a printed wiring board and a material for embedding a component in a component-embedded substrate. The printed wiring board and the component built-in board will be described later.

[II-2. Printed circuit board and board with built-in components]
The printed wiring board of the present invention can be obtained by using the resin sheet of the present invention as a build-up material for a metal foil-clad laminate in which a resin insulating layer called a core base material is completely cured. A conductor circuit is formed on the surface of the core base material by a metal foil of a metal foil-clad laminate usually used in the art, or a conductor layer obtained by peeling and then plating the metal foil.
The core base material mainly forms a conductor layer (circuit) patterned on one or both sides of a substrate such as a glass epoxy substrate, a metal substrate, a polyester substrate, a polyimide substrate, a BT resin substrate, or a thermosetting polyphenylene ether substrate. It means what was done. Further, the printed wiring board of the present invention also includes an inner layer circuit board of an intermediate product in which an insulating layer and / or a conductor layer should be further formed when the multilayer printed wiring board is manufactured. It is preferable that the surface of the conductor layer (circuit) is roughened in advance by a blackening treatment or the like from the viewpoint of adhesion of the insulating layer to the circuit board.

Specifically, when the resin sheet of the present invention is used as a build-up material or a material for embedding a component in a component-embedded substrate, the resin sheet is laminated on a conductor circuit and / or a component by a conventional method (lamination). By surface-treating the resin composition layer (insulating layer) of the resin sheet and forming a wiring pattern (conductor layer) on the surface of the insulating layer by plating, the printed wiring board of the present invention or the component-embedded substrate can be obtained. can get.
If necessary, various other steps (for example, hole processing for forming via holes, through holes, etc.) may be added.

Hereinafter, each step for manufacturing the printed wiring board of the present invention will be described.
Laminate molding uses a method generally used for laminating molding of ordinary laminated boards for printed wiring boards, for example, a multi-stage press, a multi-stage vacuum press, a laminator, a vacuum laminator, an autoclave molding machine, etc., and the temperature is, for example, 100 to 300. The temperature and pressure are, for example, 0.1 to 100 kgf / cm ² (about 9.8 kPa to about 38 MPa), and the heating time is appropriately selected in the range of, for example, 30 seconds to 5 hours. Further, if necessary, post-curing may be performed at a temperature of, for example, 150 to 300 ° C. to adjust the degree of curing.

The hole processing is carried out for the formation of via holes, through holes and the like. The hole drilling treatment is performed by using any one of known methods such as NC drill, carbon dioxide laser, UV laser, YAG laser, and plasma, or in combination of two or more if necessary.

The surface treatment of the insulating layer is carried out from the viewpoint of removing smear. Surface treatment includes roughening treatment, silane coupling treatment and the like. The roughening process also removes smear generated by the drilling process. In this case, since the roughened state differs depending on the difference in the degree of curing of the resin composition, it is preferable to select the optimum condition for the lamination molding described later in combination with the subsequent roughening treatment condition and the plating condition.

The roughening treatment comprises a swelling step, a surface roughening and and a smear melting step, and a neutralization step. The swelling step is performed by swelling the surface insulating layer with a swelling agent. The swelling agent is limited as long as it can swell the surface insulating layer to the extent that the wettability of the surface insulating layer is improved and oxidative decomposition is promoted in the next surface roughness and smear dissolution step. Not done. Examples include an alkaline solution, a surfactant solution and the like.
The surface roughness and smear dissolution steps are carried out using an oxidizing agent. Examples of the oxidizing agent include an alkaline permanganate solution and the like, and suitable specific examples thereof include an aqueous solution of potassium permanganate and an aqueous solution of sodium permanganate. Such an oxidant treatment is called wet desmear, and in addition to the wet desmear, other known roughening treatments such as plasma treatment, dry desmear by UV treatment, mechanical polishing by buffing, and sandblasting are appropriately combined. You may.
The neutralization step is to neutralize the oxidizing agent used in the previous step with a reducing agent. Examples of the reducing agent include amine-based reducing agents, and suitable specific examples thereof include acidic aqueous solutions such as an aqueous solution of hydroxylamine sulfate, an aqueous solution of ethylenediaminetetraacetic acid, and an aqueous solution of nitrilotriacetic acid.

Examples of the method for forming the wiring pattern (conductor layer) by plating include a semi-additive method, a full additive method, and a subtractive method.
As an example of the method of forming a pattern by the subtractive method, a copper foil that is a support of the resin sheet or a conductor layer formed by plating on the surface of the insulating layer is selectively copper foil or a copper foil using an etching resist. A method of forming a wiring pattern by removing the conductor layer can be mentioned.
As an example of the method of forming a pattern by the semi-additive method, a thin conductor layer is formed on the surface of the insulating layer by electroless plating or the like, and then selectively electrolytically plated using a plating resist (pattern plating), and then the plating resist is applied. An appropriate amount of plating is used to form a wiring pattern.
As an example of the method of forming a pattern by the full additive method, there is a method of forming a wiring pattern by preliminarily forming a pattern on the surface of an insulating layer using a plating resist and selectively adhering electroless plating or the like.

The printed wiring board of the present invention can also be a multilayer printed wiring board. For example, after forming the laminated board of the present invention that has been plated, an inner layer circuit is formed therein, and the obtained circuit is blackened to obtain an inner layer circuit board. The resin sheet of the present invention is arranged on one side or both sides of the inner layer circuit board thus obtained, and a metal foil (for example, copper, aluminum, etc.) or a release film (polyethylene film, polypropylene film, polycarbonate film, polyethylene terephthalate film, etc.) is further arranged. A multilayer printed wiring board is manufactured by repeating the operation of arranging (a film in which a mold release agent is applied on the surface of an ethylene tetrafluoroethylene copolymer film or the like) on the outside thereof and laminating and molding.

The component-embedded substrate of the present invention is manufactured by arranging an arbitrary component on a core base material having a cavity formed therein and laminating and molding the resin sheet as a material for embedding the component.
The component mainly refers to a component for forming a module such as an IC chip, a capacitor, and a sensor.

By laminating the resin sheets, after forming the component-embedded substrate, it is possible to form a hole processing and a wiring pattern in the same manner as in the manufacturing process of the printed wiring board described in the previous section.

Hereinafter, the present invention will be described in detail with reference to Synthesis Examples, Examples and Comparative Examples, but the present invention is not limited thereto.

（式中、ｎ^６は平均値として３から４までの範囲である。） Production / Synthesis Example of Cyanic Acid Ester Compound 1 Synthesis of α-naphthol aralkyl type cyanate ester compound (6):

(In the formula, n ⁶ is a range of 3 to 4 as an average value.)

A reactor equipped with a thermometer, a stirrer, a dropping funnel and a reflux condenser was previously cooled to 0 to 5 ° C. with a saline solution, and 7.47 g (0.122 mol) of cyanogen chloride and 35% hydrochloric acid 9. 75 g (0.0935 mol), 76 ml of water, and 44 ml of methylene chloride were charged.

（式中、ｎ^７は平均値として３から４までの範囲である。） Α-naphthol aralkyl resin (SN485, OH group equivalent: 214 g / eq. Softening) represented by the following formula (7) under stirring while keeping the temperature in the reactor at −5 to + 5 ° C. and pH at 1 or less. Point: A solution prepared by dissolving 20 g (0.0935 mol) of triethylamine (manufactured by Nippon Steel Chemical Co., Ltd.) and 14.16 g (0.14 mol) of triethylamine in 92 ml of methylene chloride was added dropwise at 86 ° C. over 1 hour using a dropping reactor. After completion of the dropping, 4.72 g (0.047 mol) of triethylamine was further added dropwise over 15 minutes.

(In the formula, n ⁷ is a range of 3 to 4 as an average value.)

After completion of the dropping, the mixture was stirred at the same temperature for 15 minutes, the reaction solution was separated, and the organic layer was separated. The obtained organic layer was washed twice with 100 ml of water, methylene chloride was distilled off under reduced pressure with an evaporator, and finally the mixture was concentrated to dryness at 80 ° C. for 1 hour and represented by the above compound (6). 23.5 g of a cyanate esterified product of α-naphthol aralkyl resin (α-naphthol aralkyl type cyanate ester compound) was obtained.

Preparation of Resin Composition and Resin Sheet- Example 1:
As the bifunctional cyanate ester compound (A), methyl ethyl ketone of bisphenol A type cyanate ester (TA, cyanate ester equivalent: 139 g / eq., Manufactured by Mitsubishi Gas Chemicals Corporation) (hereinafter, may be abbreviated as "MEK"). 50 parts by mass of solution (40% by mass of non-volatile content) (20 parts by mass in terms of non-volatile content), molten silica (SFP-330MC, manufactured by Electrochemical Industry Co., Ltd., average particle size 0) as inorganic filler (B) .7 μm) 150 parts by mass, fused silica (SC-4053SQ, manufactured by Admatex Co., Ltd., average particle size 1.1 μm) 150 parts by mass, as silicone composite powder (C), silicone composite powder (KMP-605M, Shin-Etsu Chemical Co., Ltd.) 15 parts by mass of maleimide compound (D), manufactured by Daiwa Kasei Kogyo Co., Ltd., 40 parts by mass of novolac type maleimide (BMI-2300, maleimide equivalent: 186 g / eq., Manufactured by Daiwa Kasei Kogyo Co., Ltd.) Obtained as compound (E) as a naphthalene skeleton-containing epoxy compound (HP-9500, epoxy equivalent: 230 g / eq., Manufactured by DIC Co., Ltd.) as 30 parts by mass, as a polyfunctional cyanate ester compound (F) according to Synthesis Example 1. 20 parts by mass of MEK solution (10 parts by mass in terms of non-volatile content) of the obtained α-naphthol aralkyl type cyanate ester compound (cyanic acid ester equivalent: 261 g / eq.), MEK solution of manganese octylate as a curing accelerator 1. 0 parts by mass (0.1 parts by mass in terms of non-volatile content) was dissolved or dispersed in MEK. Then, the mixture is stirred for 30 minutes using a high-speed stirrer to prepare a bifunctional cyanate ester compound (A), an inorganic filler (B), a silicone composite powder (C), a maleimide compound (D), and an epoxy compound (E). A solution of the resin composition containing the polyfunctional cyanate ester compound (F) was obtained. This varnish was applied to the matte surface of a copper foil (MT-Ex, manufactured by Mitsui Mining & Smelting Co., Ltd.), heated and dried at an average temperature of 110 ° C. for 5 minutes, and the resin thickness was obtained by using the copper foil as a support. A 100 μm resin sheet was obtained. The thermal stress coefficient X of the cured product of the resin sheet is 200, which falls within the range according to claim 1.

Preparation of Adhesion Evaluation Substrate An insulating layer is formed by arranging a resin-coated surface of the resin sheet on one side of a silicon wafer, performing laminating molding at a pressure of 30 kgf / cm2 and a temperature of 220 ° C. for 120 minutes, and removing the copper foil. An evaluation substrate of 30 μm was obtained.

Preparation of Young Rate Evaluation Substrate A cavity (200 mm * 200 mm * 0.) Is located in the center of a resin substrate (330 mm * 330 mm * 0.8 mmt) from which an outer layer such as a copper foil or a polymer film has been removed after laminating and molding an arbitrary prepreg. 8 mmt) is formed, only the resin part of the resin sheet is placed in the cavity as a powder, and laminating molding is performed at a pressure of 30 kgf / cm2 and a temperature of 220 ° C. for 120 minutes to obtain an evaluation substrate having a thickness of 0.8 mmt. Obtained.

Preparation of Embedability Evaluation Substrate A via having a diameter of 100 μm and a diameter of 200 μm was formed on an unclad plate (520 mm * 345 mm * 0.2 mmt), and a resin-coated surface of the resin sheet was formed on one side of the via-formed unclad plate. An evaluation substrate was obtained by arranging and performing arbitrary laminating molding.

-Example 2:
The varnish (solution of the resin composition) was adjusted in the same manner as in Example 1 except that the amount of the silicone composite powder (KMP-605M, average particle diameter 3 μm) used as the silicone composite powder (C) was 20 parts by mass. Then, a resin sheet and various evaluation substrates using the resin sheet were obtained. The thermal stress coefficient X of the cured product of the resin sheet is 165, which falls within the range according to claim 1.

-Example 3:
As the bifunctional cyanate ester compound (A), a MEK solution (nonvolatile content 40% by mass) of a bisphenol A type cyanate ester (TA, cyanate ester equivalent: 139 g / eq., Manufactured by Mitsubishi Gas Chemicals Corporation) 12. 5 parts by mass (5 parts by mass in terms of non-volatile content), as the polyfunctional cyanate ester compound (F), the amount of the MEK solution of the α-naphthol aralkyl type cyanate ester compound (cyanic acid ester equivalent: 261 g / eq.) The varnish (solution of the resin composition) was adjusted in the same manner as in Example 1 except that 50 parts by mass (25 parts by mass in terms of non-volatile content) was used to obtain a resin sheet and various evaluation substrates using the same. .. The thermal stress coefficient X of the cured product of the resin sheet is 198, which falls within the range according to claim 1.

-Example 4:
As the bifunctional cyanate ester compound (A), a MEK solution (nonvolatile content 40% by mass) of bisphenol A type cyanate ester (TA, cyanate ester equivalent: 139 g / eq., Manufactured by Mitsubishi Gas Chemicals Corporation) 62. 5 parts by mass (25 parts by mass in terms of non-volatile content), as the polyfunctional cyanate ester compound (F), the amount of the MEK solution of the α-naphthol aralkyl type cyanate ester compound (cyanic acid ester equivalent: 261 g / eq.) The varnish (solution of the resin composition) was adjusted in the same manner as in Example 1 except that 10 parts by mass (5 parts by mass in terms of non-volatile content) was used to obtain a resin sheet and various evaluation substrates using the same. .. The thermal stress coefficient X of the cured product of the resin sheet is 199, which falls within the range according to claim 1.

Example 5:
As the bifunctional cyanate ester compound (A), a MEK solution (nonvolatile content 40% by mass) of bisphenol A type cyanate ester (TA, cyanate ester equivalent: 139 g / eq., Manufactured by Mitsubishi Gas Chemicals Corporation) 75 mass. The varnish (solution of the resin composition) was adjusted in the same manner as in Example 1 except for the portion (30 parts by mass in terms of non-volatile content) to obtain a resin sheet and various evaluation substrates using the resin sheet. The thermal stress coefficient X of the cured product of the resin sheet is 200, which falls within the range according to claim 1.

-Comparative example 1:
The varnish (solution of the resin composition) was adjusted in the same manner as in Example 1 except that the amount of the silicone composite powder (C) (KMP-605M, average particle diameter 3 μm) was 0 parts by mass, and the resin sheet and the resin sheet and An evaluation substrate using it was obtained. The thermal stress coefficient X of the cured product of the resin sheet is 206, which is outside the range according to claim 1.

-Comparative example 2:
As the inorganic filler (B), 50 parts by mass of fused silica (SFP-330MC, manufactured by Denki Kagaku Kogyo Co., Ltd., average particle diameter 0.7 μm), molten silica (SC-4053SQ, manufactured by Admatex Co., Ltd., average particles). A varnish (solution of the resin composition) was prepared in the same manner as in Comparative Example 1 except that the diameter was 1.1 μm) and 50 parts by mass, and a resin sheet and various evaluation substrates using the resin sheet were obtained. The thermal stress coefficient X of the cured product of the resin sheet is 228, which is outside the range according to claim 1.

-Comparative example 3:
As the inorganic filler (B), 100 parts by mass of fused silica (SFP-330MC, manufactured by Denki Kagaku Kogyo Co., Ltd., average particle diameter 0.7 μm), molten silica (SC-4053SQ, manufactured by Admatex Co., Ltd., average particles). A varnish (solution of the resin composition) was prepared in the same manner as in Comparative Example 1 except that the diameter was 1.1 μm) and 100 parts by mass, and a resin sheet and various evaluation substrates using the same were obtained. The thermal stress coefficient X of the cured product of the resin sheet is 206, which is outside the range according to claim 1.

-Comparative example 4:
Use of MEK solution (nonvolatile content 40% by mass) of bisphenol A type cyanate ester (TA, cyanate ester equivalent: 139 g / eq., Manufactured by Mitsubishi Gas Chemicals Corporation) as the bifunctional cyanate ester compound (A). The amount is 0 parts by mass, and the amount of the MEK solution of the α-naphthol aralkyl type cyanate ester compound (cyanic acid ester equivalent: 261 g / eq.) As the polyfunctional cyanate ester compound (F) is 40 parts by mass (nonvolatile). The varnish (solution of the resin composition) was prepared in the same manner as in Example 1 except that the amount was 20 parts by mass in terms of minutes), and a resin sheet and various evaluation substrates using the same were obtained. The thermal stress coefficient X of the cured product of the resin sheet is 206, which is outside the range according to claim 1.

-Comparative example 5:
Use of MEK solution (nonvolatile content 40% by mass) of bisphenol A type cyanate ester (TA, cyanate ester equivalent: 139 g / eq., Manufactured by Mitsubishi Gas Chemicals Co., Ltd.) as the bifunctional cyanate ester compound (A). The amount is 0 parts by mass, and as the epoxy compound (E), 10 parts by mass of a naphthalene skeleton-containing epoxy compound (HP-9500, epoxy equivalent: 230 g / eq., Manufactured by DIC Co., Ltd.) is used as a liquid epoxy compound (828, Epoxy equivalent: 189 g / eq., DIC Co., Ltd.) Substituted with 10 parts by mass to prepare an α-naphthol aralkyl type cyanate ester compound (cyanic acid ester equivalent: 261 g / eq) as a polyfunctional cyanate ester compound (F). The varnish (solution of the resin composition) was prepared in the same manner as in Example 1 except that the amount of the MEK solution used in (.) Was 40 parts by mass (20 parts by mass in terms of non-volatile content), and the resin sheet and the resin sheet were prepared in the same manner as in Example 1. Various evaluation substrates used were obtained. The thermal stress coefficient X of the cured product of the resin sheet is 203, which is outside the range according to claim 1.

Evaluation of resin sheet (1) Flexibility:
Using the resin sheets produced by the procedures of Examples 1 to 5 and Comparative Examples 1 to 7, in order to confirm the flexibility of the resin sheet, a strip-shaped sample of the obtained resin sheet of 30 mm × 100 mm having a diameter of 10 mm and It was wound around a rod having a diameter of 20 mm, and the presence or absence of cracks was visually observed. When wound around a rod having a diameter of 10 mm, those without cracks were marked with “◯”. Subsequently, for those in which cracks were generated, it was visually observed whether or not cracks were generated when the resin sheet was wound around a rod having a diameter of 20 mm. Those without cracks were marked with "Δ". Those in which cracks occurred in all the above evaluations were marked with "x". The results are shown in Table 1.

(2) Minimum melt viscosity of the resin sheet in the B stage state:
Using 1 g of resin powder collected from the resin sheet as a sample, the minimum melt viscosity was measured with a rheometer (ARES-G2 manufactured by TA Instruments). Here, a disposable plate having a plate diameter of 25 mm is used, and the minimum resin is used under the conditions of a heating rate of 2 ° C./min, a frequency of 10.0 rad / sec, and a strain of 0.1% in the range of 40 ° C. to 180 ° C. The melt viscosity was measured. The results are shown in Table 1.

(3) Via embedding property:
It is sufficient to laminate the resin sheet on one side of an unclad plate having a thickness of 0.2 mmt with vias having a diameter of 100 μm and a diameter of 200 μm opened, mold the resin sheet by a vacuum multi-stage press, and observe the cross section of the obtained substrate. I checked if it was possible to fill the vias. A via having a diameter of 100 μm was marked with “◯” when it was sufficiently filled with resin. Subsequently, for those with insufficient filling, the same evaluation was performed on a via having a diameter of 200 μm, and when the via was sufficiently filled with resin, it was evaluated as “Δ”. In all the above evaluations, when the resin could not be sufficiently filled, it was evaluated as "x". The results are shown in Table 1.

(4) Adhesion with silicon wafer:
The resin sheet was laminated on a silicon wafer, molded by a vacuum multi-stage press, and then a sample diced into a 4 cm square was absorbed for 96 hours at 121 ° C.-0.2 MPa, and a cross-cut test was performed on the resin surface. Adhesion was judged. Specifically, 6 vertical and 6 horizontal cuts are made in the resin surface at 1 mm width intervals to form a grid of 25 squares, and after 1 minute has passed after attaching the cellophane adhesive tape, It was instantly peeled off perpendicular to the resin surface. According to the judgment criteria, those with reference values 0 to 1 were designated as "○", those with reference values 2 to 3 were designated as "Δ", and those with reference values 4 to 5 were designated as "x". The results are shown in Table 1.

(5) Young's modulus E:
A cured resin product having a thickness of 0.8 mmt was measured by a tensile test using an autograph (AG-Xplus manufactured by Shimadzu Corporation). The results are shown in Table 1.

(6) Coefficient of thermal expansion α:
For a cured resin product having a thickness of 0.8 mmt, a 30 mm square test piece was prepared, and the temperature was raised from 40 ° C. to 340 ° C. at 10 ° C. The coefficient of linear expansion α at ° C was measured. The results are shown in Table 1.

(7) Thermal stress coefficient X:
X was calculated by multiplying the obtained Young's modulus E by the coefficient of thermal expansion α. The results are shown in Table 1.

(8) Glass transition temperature Tg:
For a cured resin product having a thickness of 0.8 mmt, a test piece having a thickness of 12 mm × 25 mm was prepared and measured at 10 ° C./min using a DMA measuring device (dynamic viscoelasticity measuring device DMA Q400 manufactured by TA Instruments). The temperature was raised with, and the peak position of Loss Modulus was defined as the glass transition temperature. The results are shown in Table 1.

As described above, when the resin composition of the present invention is used as a material for an insulating layer of a printed wiring board and a material for embedding a component of a component-embedded substrate, the resin sheet has excellent flexibility and embedding property. Since it has excellent adhesion to parts and exhibits high heat resistance, it is extremely useful as a material for an insulating layer of a printed wiring board and a material for embedding parts in a component-embedded substrate.

Claims (10)

A resin sheet comprising an outer layer, which is one of any kind, selected from the group consisting of a polymer film, a metal foil, and a metal film, and an insulating layer composed of a resin composition laminated on the outer layer. The composition is a bifunctional cyanate ester compound (A), an inorganic filler (B) , a silicone composite powder (C) , a maleimide compound (D), an epoxy compound (E), and a polyfunctional cyanate ester compound (F). The Young's modulus of the cured product obtained by curing the resin composition to the C stage state was measured by E (GPa) and thermal analysis (heating rate: 10 ° C./min, temperature rising range:). When the thermal expansion coefficient at 60 ° C to 120 ° C measured at (40 ° C to 340 ° C) is α (ppm / K) and the thermal stress coefficient obtained by multiplying Young's modulus E and the thermal expansion coefficient α is X. , A resin sheet having a thermal stress coefficient X of 150 to 204 GPa · ppm / K. The resin sheet according to claim 1, wherein the content of the bifunctional cyanate ester compound (A) in the resin composition is 5 parts by mass or more with respect to 100 parts by mass of the resin solid content in the resin composition. The resin sheet according to claim 1 or 2 , wherein the content of the inorganic filler (B) in the resin composition is 200 parts by mass or more with respect to 100 parts by mass of the resin solid content in the resin composition. The resin according to any one of claims 1 to 3 , wherein the content of the silicone composite powder (C) in the resin composition is 15 parts by mass or more with respect to 100 parts by mass of the resin solid content in the resin composition. Sheet. The resin sheet according to any one of claims 1 to 4 , wherein the metal foil or metal film is a copper or aluminum foil or film. The resin sheet according to any one of claims 1 to 4 , wherein the polymer film is any one selected from the group consisting of polyester, polyimide and polyamide. The resin sheet according to any one of claims 1 to 6 , wherein the insulating layer made of the resin composition is in a B stage state. The minimum melt viscosity measured by a rheometer under the following conditions of the insulating layer in the B stage state is 1,000 Pa · s or less.
[Measurement condition]
Plate diameter: 25 mm
Temperature rise rate: 2 ° C / min Temperature range: From 40 ° C to 180 ° C Frequency: 10.0 rad / sec Distortion: 0.1%
The resin sheet according to claim 7. A printed wiring board containing the resin sheet according to any one of claims 1 to 8. A component-embedded substrate containing the resin sheet according to any one of claims 1 to 8.