Prepreg, and metal-clad laminate and wiring board each using same

Abstract

One aspect of the present invention relates to a prepreg which comprises a thermosetting resin composition or a semi-cured product of the thermosetting resin composition, and a glass cloth, wherein: the thermosetting resin composition contains a phenolic resin (A) and at least one of an epoxy resin (B) and a maleimide compound (C); and the glass cloth contains 45-55 mass% of SiO2, 20-30 mass% of Al2O3, 3.0 mass% or less of MgO, and 10-15 mass% of P2O5 with respect to the total amount of the components of the glass cloth.

Description

Prepreg, and metal-clad laminate and wiring board using the same

[0001] The present invention relates to a prepreg, and a metal-clad laminate and a wiring board using the same.

[0002] As the amount of information processed increases in various electronic devices, advances in packaging technologies, such as higher integration of semiconductor devices, higher density wiring, and multi-layering, are being made. Furthermore, wiring boards used in various electronic devices are required to be high-frequency compatible, such as millimeter-wave radar boards for automotive applications. To increase the signal transmission speed, wiring boards used in various electronic devices are required to reduce loss during signal transmission, and this is particularly true for high-frequency compatible wiring boards. To meet this requirement, substrate materials for forming the substrates of wiring boards used in various electronic devices are required to have low dielectric properties.

[0003] Such a substrate material may be, for example, a glass fiber having a SiO content in the range of 60.00 to 70.00 mass % relative to the total amount of glass fibers. ２ and Al in the range of 20.00 to 30.00 mass% ２ O ３ and MgO in the range of 5.00 to 15.0 mass % and Fe in the range of 0.15 to 1.50 mass %. ２ O ３ and a total of 0.02 to 0.20 mass% of Li ２ O, Na ２ O and K ２ A glass fiber reinforced resin molded product (Patent Document 1) has been reported, which comprises glass fibers having a composition containing SiO and a thermoplastic resin or a thermosetting resin. ２ and Al in the range of 13.0 to 17.0 mass% ２ O ３ and B in the range of 15.0 to 21.5 mass% ２ O ３ 2.0 to 6.0% by mass of MgO; 2.0 to 6.0% by mass of CaO; and 1.0 to 4.0% by mass of TiO. ２ and less than 1.5% by mass of F. ２ and Li ２O, Na ２ O and K ２ A glass fiber reinforced resin molded article including glass fibers having a composition in which the total amount of O is less than 0.6 mass % and a thermoplastic resin or a thermosetting resin has also been reported (Patent Document 2).

[0004] Or E-glass (SiO ２ and Al ２ O ３ a layer containing a cured product of a thermosetting resin composition and S-glass (SiO ２ and Al ２ O ３ A laminated plate in which a plurality of layers containing a cured product of a thermosetting resin composition and glass fibers (the total of which is 80% or more of glass fibers) are laminated has also been reported (Patent Document 3).

[0005] The glass fibers described in Patent Documents 1 to 3 are said to have low dielectric properties and a high tensile modulus. However, with the recent trend toward even higher performance electronic devices and significant increases in information communication speeds, substrate materials that can accommodate larger packages and more microfabrication are required for semiconductor package substrates, and even better low dielectric properties are being demanded. In particular, as wiring boards become thinner and larger, there is a problem that warping occurs in semiconductor packages that mount semiconductor chips on wiring boards, making them more susceptible to mounting defects. In order to suppress warping in semiconductor packages that mount semiconductor chips on wiring boards, the substrate material that constitutes the insulating layer of the wiring board is also required to have a low thermal expansion coefficient when cured.

[0006] The present invention has been made in light of these circumstances, and its object is to provide a prepreg having excellent low dielectric properties and a low coefficient of thermal expansion, as well as a metal-clad laminate and a wiring board using the same.

[0007] International Publication No. 2022 / 075273 International Publication No. 2017 / 171101 International Publication No. 2020 / 130007

[0008] As a result of extensive research to solve the above problems, the present inventors have found that the above problems can be solved by the following configuration, and have completed the present invention through further research based on this finding.

[0009] A prepreg according to one aspect of the present invention comprises a thermosetting resin composition or a semi-cured product of the thermosetting resin composition, and glass cloth, wherein the thermosetting resin composition contains a phenolic resin (A) and at least one of an epoxy resin (B) and a maleimide compound (C), and the glass cloth contains SiO ２ 45 to 55 mass% of Al ２ O ３ 20 to 30 mass %, MgO 3.0 mass % or less, P ２ O ５ It is characterized in that it contains 10 to 15 mass % of

[0010] A metal-clad laminate according to one aspect of the present invention is characterized by comprising an insulating layer containing a cured product of the prepreg, and a metal layer.

[0011] A wiring board according to one aspect of the present invention is characterized by comprising an insulating layer containing a cured product of the prepreg, and wiring.

[0012] Fig. 1 is a schematic cross-sectional view showing the configuration of a prepreg according to one embodiment of the present invention, Fig. 2 is a schematic cross-sectional view showing the configuration of a metal-clad laminate according to one embodiment of the present invention, and Fig. 3 is a schematic cross-sectional view showing the configuration of a wiring board according to one embodiment of the present invention.

[0013] Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to these.

[0014] <Prepreg> The prepreg of the present embodiment comprises a thermosetting resin composition or a semi-cured product of the thermosetting resin composition, and glass cloth, wherein the thermosetting resin composition contains a phenolic resin (A) and at least one of an epoxy resin (B) and a maleimide compound (C), and the glass cloth contains SiO ２ 45 to 55 mass% of Al ２ O ３ 20 to 30 mass %, MgO 3.0 mass % or less, P ２ O ５ Contains 10 to 15 mass % of

[0015] The prepreg of this embodiment having such a configuration has excellent low dielectric properties and a low coefficient of thermal expansion, and therefore the metal-clad laminate and wiring board obtained using the prepreg of this embodiment have excellent low dielectric properties (particularly a low relative dielectric constant) and are also suppressed from warping.

[0016] Hereinafter, each configuration of the prepreg according to this embodiment will be specifically described.

[0017] [Thermosetting Resin Composition] The thermosetting resin composition according to this embodiment (hereinafter also simply referred to as "resin composition") contains a phenolic resin (A) and at least one of an epoxy resin (B) and a maleimide compound (C).

[0018] (Phenol Resin (A)) As the phenol resin (A), a compound containing in the molecule a hydroxy group bonded to an aromatic ring can be used. Examples thereof include bisphenol A type phenolic resins, bisphenol E type phenolic resins, bisphenol F type phenolic resins, bisphenol S type phenolic resins, phenol novolac resins, bisphenol A novolac type phenolic resins, glycidyl ester type phenolic resins, aralkyl novolac type phenolic resins, biphenyl aralkyl type phenolic resins, cresol novolac type phenolic resins, polyfunctional phenolic resins, naphthol resins, naphthol novolac resins, polyfunctional naphthol resins, anthracene type phenolic resins, naphthalene skeleton-modified novolac type phenolic resins, phenol aralkyl type phenolic resins, naphthol aralkyl type phenolic resins, dicyclopentadiene type phenolic resins, biphenyl type phenolic resins, alicyclic phenolic resins, polyol type phenolic resins, phosphorus-containing phenolic resins, polymerizable unsaturated hydrocarbon group-containing phenolic resins, and hydroxyl group-containing silicone resins. Among these, it is preferable to use phenol novolac resin and bisphenol A type phenol resin.

[0019] As the phenolic resin (A), the above-mentioned phenolic resins may be used alone or in combination of two or more, depending on the situation.

[0020] (Epoxy Resin (B)) The epoxy resin (B) is not particularly limited as long as it is an epoxy resin that can be used to form various organic substrates that can be used to manufacture laminates and circuit boards. Specific examples include bisphenol A epoxy resins, bisphenol F epoxy resins, bisphenol S epoxy resins, aralkyl epoxy resins, phenol novolac epoxy resins, alkylphenol novolac epoxy resins, biphenyl epoxy resins, biphenylene epoxy resins, bisphenol epoxy resins, naphthalene epoxy resins, dicyclopentadiene epoxy resins, epoxidized products of condensates of phenols and aromatic aldehydes having a phenolic hydroxyl group, triglycidyl isocyanurate, alicyclic epoxy resins, etc. Among these, biphenylene epoxy resins and naphthalene epoxy resins are preferably used.

[0021] As the epoxy resin (B), the above-mentioned epoxy resins may be used alone or in combination of two or more, depending on the situation.

[0022] (Maleimide Compound (C)) The maleimide compound (C) can be any compound having a maleimide group in the molecule. Specific examples of the maleimide compound (C) include monofunctional maleimide compounds having one maleimide group in the molecule, polyfunctional maleimide compounds having two or more maleimide groups in the molecule, and modified maleimide compounds. Examples of the modified maleimide compound include modified maleimide compounds in which a portion of the molecule is modified with an amine compound, modified maleimide compounds in which a portion of the molecule is modified with a silicone compound, and modified maleimide compounds in which a portion of the molecule is modified with an amine compound and a silicone compound.

[0023] More specific examples include maleimide compounds having two or more N-substituted maleimide groups in one molecule, maleimide compounds having an indane structure, maleimide compounds having at least one group selected from an alkyl group having 6 or more carbon atoms and an alkylene group having 6 or more carbon atoms, and maleimide compounds having a benzene ring in the molecule.

[0024] Among these, it is preferable to use a maleimide compound having two or more N-substituted maleimide groups in one molecule, or a maleimide compound having a benzene ring in the molecule.

[0025] The maleimide compound (C) used in the present embodiment may be a commercially available product, and examples thereof include BMI-4000, BMI-2300, BMI-TMH, BMI-4000, and BMI-5100 manufactured by Daiwa Chemical Industry Co., Ltd.; MIR-3000-70MT and MIR-5000 manufactured by Nippon Kayaku Co., Ltd.; and BMI-689, BMI-1500, BMI-3000J, and BMI-5000 manufactured by Designer Molecules Inc.

[0026] As the maleimide compound (C), the above-mentioned maleimide compounds may be used alone or in combination of two or more kinds.

[0027] (Benzoxazine Compound (D)) The thermosetting resin composition preferably contains a benzoxazine compound (D). When the resin composition contains the benzoxazine compound (D), the cured product of the resin composition has excellent adhesion (adhesion strength) to a metal layer (e.g., copper foil, etc.), and the thermal expansion coefficient can be more reliably reduced. The benzoxazine compound (D) is not particularly limited as long as it is a compound having at least one benzoxazine ring. For example, a benzoxazine compound having an alkenyl group in the molecule can be mentioned.

[0028] A benzoxazine compound having an alkenyl group in the molecule has not only an alkenyl group but also a benzoxazine group in the molecule. The alkenyl group is not particularly limited, but examples thereof include alkenyl groups having 2 to 6 carbon atoms. Specific examples of the alkenyl group include vinyl groups, allyl groups, propenyl groups, and butenyl groups. Among these, allyl groups and propenyl groups are preferred, and allyl groups are more preferred. In other words, the benzoxazine compound (D) preferably contains a benzoxazine compound (D-1) having an allyl group in the molecule.

[0029] Examples of the benzoxazine group include a benzoxazine group represented by the following formula (1) and a benzoxazine group represented by the following formula (2): Examples of the benzoxazine compound (D) include not only benzoxazine compounds having a benzoxazine group represented by the following formula (1) in the molecule and benzoxazine compounds having a benzoxazine group represented by the following formula (2) in the molecule, but also benzoxazine compounds having a benzoxazine group represented by the following formula (1) and a benzoxazine group represented by the following formula (2) in the molecule.

[0030]

[0031] In the formula (1), R １ represents an allyl group, and a represents 1 to 4. a represents R １ is an average value of the degree of substitution of 1 to 4, and is preferably 1.

[0032]

[0033] In the formula (2), R ２ represents an allyl group.

[0034] More specifically, the allyl group-containing benzoxazine compound (D-1) includes a benzoxazine compound represented by the following formula (3):

[0035]

[0036] In the formula (3), R ３ and R ４ represents an allyl group; Y represents an alkylene group; b and c each independently represent 1 to 4;

[0037] The alkylene group is not particularly limited and examples thereof include a methylene group, an ethylene group, a propylene group, a butylene group, a pentylene group, a hexylene group, a heptylene group, an octane group, an icosane group, and a hexatriacontane group. Among these, a methylene group is preferred.

[0038] In the formula (3), b is R ３ The average value of the degree of substitution is 1 to 4, and preferably 1. In addition, in the formula (3), c is R４ is an average value of the degree of substitution of 1 to 4, and is preferably 1.

[0039] As the benzoxazine compound (D), commercially available products may be used, for example, "ALP-d" manufactured by Shikoku Chemicals Corporation.

[0040] As the benzoxazine compound (D), the benzoxazine compounds exemplified above may be used alone or in combination of two or more kinds.

[0041] (Elastomer (E)) The thermosetting resin composition preferably contains an elastomer (E) containing at least one of a high molecular weight material (E-1) having a weight average molecular weight of 10,000 or more and 900,000 or less, and a core-shell rubber (E-2).

[0042] It is believed that the thermosetting resin composition can obtain a further low coefficient of thermal expansion in the cured product by including a polymer (E-1) having a weight average molecular weight (Mw) of 10,000 or more and 900,000 or less. The polymer (E-1) more preferably has a weight average molecular weight (Mw) of 10,000 or more and 600,000 or less. In this specification, the weight average molecular weight may be a molecular weight measured by a general molecular weight measurement method, and specific examples include values ​​measured using gel permeation chromatography (GPC).

[0043] The polymer (E-1) preferably contains at least one of an acrylic resin and a styrene copolymer having a weight-average molecular weight of 10,000 or more and 900,000 or less. It is believed that the polymer (E-1) containing at least one of an acrylic resin and a styrene copolymer can provide a cured product with a further low coefficient of thermal expansion.

[0044] Specific acrylic resins in this embodiment preferably have structures represented by the following formulas (4), (5), and (6).

[0045]

[0046]

[0047]

[0048] In the above formulas (4) to (6), x, y, and z represent mole fractions, and satisfy the following: x+y+z≦1, 0<x≦0.2, 0.6≦y≦0.95, and 0.05≦z≦0.2.

[0049] In the above formula (5), R ５ is a hydrogen atom or a methyl group, R ６ contains at least one of a glycidyl group and an epoxidized alkyl group out of a hydrogen atom, an alkyl group, a glycidyl group and an epoxidized alkyl group.

[0050] In the above formula (6), R ７ is a hydrogen atom or a methyl group, R ８ is Ph (phenyl group), -COOCH ２ Ph or -COO(CH ２ ) ２ It is Ph.

[0051] Preferably, the main chain of the acrylic resin has at least one structure represented by formula (4), at least one structure represented by formula (5), and at least one structure represented by formula (6).

[0052] When the main chain of the acrylic resin has structures represented by formula (4), formula (5), and formula (6), the order of arrangement of the structures represented by formula (4), formula (5), and formula (6) is not particularly limited. In this case, in the main chain of the acrylic resin, the structure represented by formula (4) may be continuous or discontinuous, the structure represented by formula (5) may be continuous or discontinuous, and the structure represented by formula (6) may be continuous or discontinuous.

[0053] Here, R in the formula (5) ６ The meaning of containing at least one of a glycidyl group and an epoxidized alkyl group among a hydrogen atom, an alkyl group, a glycidyl group, and an epoxidized alkyl group will be explained below. ６ The acrylic resin will be described separately for cases where it has only one structure represented by formula (5) and cases where it has two or more structures represented by formula (5).

[0054] In the former case, that is, when the acrylic resin has one structure represented by formula (5), R ６ is a glycidyl group or an epoxidized alkyl group.

[0055] In the latter case, that is, when the acrylic resin has two or more structures represented by formula (5), R in at least one of the structures represented by formula (5) ６ is a glycidyl group or an epoxidized alkyl group, and R in the remaining structure represented by formula (5) ６ is a hydrogen atom or an alkyl group. ６ is a glycidyl group or an epoxidized alkyl group, so that R ６ However, it may be a glycidyl group or an epoxidized alkyl group.

[0056] The structure represented by the formula (6) is a group consisting of Ph (phenyl group), —COOCH ２ Ph, -COO(CH ２ ) ２ Ph. Ph, -COOCH ２ Ph, -COO(CH ２ ) ２ Ph is thermally stable, and therefore increases the strength of the cured resin composition, and can improve the heat resistance of laminates (metal-clad laminates and wiring boards).

[0057] The styrene-based copolymer that can be used in the present embodiment is a copolymer obtained by polymerizing two or more monomers including a styrene monomer, and is not particularly limited as long as the weight average molecular weight is within the above range. Examples include methylstyrene (ethylene / butylene) methylstyrene block copolymer, methylstyrene (ethylene-ethylene / propylene) methylstyrene block copolymer, styrene isoprene block copolymer, hydrogenated styrene isoprene styrene block copolymer, styrene (ethylene / butylene) styrene block copolymer, styrene (ethylene-ethylene / propylene) styrene block copolymer, methylstyrene (styrene / butadiene random copolymer block) methylstyrene copolymer, styrene (styrene / butadiene random copolymer block) styrene copolymer, styrene butadiene block copolymer such as styrene butadiene styrene block copolymer, styrene isobutylene styrene block copolymer, styrene (butadiene / butylene) styrene block copolymer, and hydrogenated products in which at least a portion of these is hydrogenated.

[0058] As the styrene-based copolymer, commercially available products may be used, and examples thereof include Tuftec P1500, Tuftec H1221, Tuftec H1041, Tuftec H1517, Tuftec M1913, Tuftec M1981, and SOE1605 manufactured by Asahi Kasei Corporation, and Asaprene T437 manufactured by Asahi Kasei Corporation.

[0059] The polymer (E-1) does not include the phenol resin (A), the epoxy resin (B), the maleimide compound (C), the benzoxazine compound (D), or the core-shell rubber (E-2).

[0060] The core-shell rubber (E-2) that can be used in this embodiment is an aggregate of rubber particles, and each rubber particle has a core-shell multilayer structure. The rubber particles are formed of a core and a shell. At least one of the core and the shell has elasticity. By including such a core-shell rubber (E-2) in the resin composition, the impact resistance, thermal shock resistance, and drilling processability of the cured product can be improved without impairing heat resistance.

[0061] Preferably, the core-shell rubber (E-2) contains silicone in at least one of the core and the shell. This further enhances thermal shock resistance. In other words, compared to rubbers not containing silicone, impact resistance can be improved even at lower temperatures.

[0062] The core can contribute to toughening of the cured product of the resin composition. The core is a particulate rubber. The rubber may be a copolymer or a homopolymer. The polymer constituting the core is not particularly limited, but examples thereof include silicone / acrylic polymers, acrylic polymers, silicone polymers, butadiene polymers, and isoprene polymers.

[0063] The shell is highly compatible with the resin components in the resin composition and can contribute to improving adhesive strength. The shell is present on the surface of the core. The shell is composed of multiple graft chains. One end of each graft chain is bonded to the surface of the core and serves as a fixed end, and the other end is a free end. The graft chains may be copolymers or homopolymers. The polymer constituting the shell is not particularly limited, but examples thereof include acrylic copolymers, polymethyl methacrylate, and polystyrene.

[0064] 50% volume average particle diameter (D ５０ The 50% volume average particle diameter (D) of the core-shell rubber (E-2) is preferably 0.01 μm or more and 0.5 μm or less, more preferably 0.05 μm or more and 0.3 μm or less. ５０ When the 50% volume average particle diameter (D ) of the core-shell rubber (E-2) is 0.01 μm or more, the impact resistance of the cured product can be further improved. ５０ When the diameter of the core-shell rubber (E-2) is 0.5 μm or less, the core-shell rubber (E-2) is easily dispersed uniformly in the resin composition, and as a result, the core-shell rubber (E-2) is easily dispersed uniformly in the cured product. Here, the "50% volume average particle diameter" refers to the particle diameter (D ５０ ) means

[0065] (Inorganic Filler (F)) The thermosetting resin composition may contain an inorganic filler (F) as needed, as long as the effects of the present invention are not impaired. This is thought to improve the heat resistance and other properties of the cured product of the resin composition.

[0066] The inorganic filler (F) is not particularly limited as long as it can be used as an inorganic filler contained in a resin composition. Examples of the inorganic filler (F) include metal oxide particles, metal hydroxide particles, molybdate particles, nitride particles, titanate particles, magnesium carbonate particles such as anhydrous magnesium carbonate particles, calcium carbonate particles, quartz glass particles, talc particles, aluminum borate particles, and barium sulfate particles. Examples of the metal oxide particles include silica particles, alumina particles, titanium oxide particles, magnesium oxide particles, and mica particles. Examples of the silica particles include spherical silica such as crushed silica and fused spherical silica. Examples of the metal hydroxide particles include boehmite particles, magnesium hydroxide particles, and aluminum hydroxide particles. Examples of the molybdate particles include zinc molybdate particles, calcium molybdate particles, and magnesium molybdate particles. Examples of the nitride particles include aluminum nitride particles and boron nitride particles. Examples of the titanate particles include barium titanate particles, strontium titanate particles, calcium titanate particles, and aluminum titanate particles.

[0067] Among these, the inorganic filler (F) preferably contains at least one selected from the group consisting of silica particles, aluminum hydroxide particles, talc particles, magnesium hydroxide particles, and boehmite particles.

[0068] The inorganic filler (F) may be any of the above inorganic fillers, or may be a combination of two or more of them. When two or more of the above inorganic fillers are used in combination, silica particles may be used in combination with one or more inorganic fillers other than silica particles.

[0069] The inorganic filler (F) may be a surface-treated or untreated inorganic filler. Examples of the surface treatment include treatment with a silane coupling agent.

[0070] (Content) The content of the phenolic resin (A) is preferably 0.1 to 60% by mass, and more preferably 1 to 40% by mass, based on the total amount of resin components in the resin composition. When the content of the phenolic resin (A) is 0.1% by mass or more based on the total amount of resin components in the resin composition, a decrease in adhesive strength in a cured product of the resin composition can be suppressed, and heat resistance can be improved. In this specification, the adhesive strength in a cured product of the resin composition means the adhesive strength with a metal layer (e.g., copper foil). When the content of the phenolic resin (A) is 60% by mass or less based on the total amount of resin components in the resin composition, a prepreg with a low thermal expansion coefficient can be more reliably obtained.

[0071] In this specification, the term "total amount of resin components" means the total amount of resin components contained in a resin composition, and for example, when the resin composition contains a phenolic resin (A) and an epoxy resin (B), it means the sum of these; when the resin composition contains a phenolic resin (A) and a maleimide compound (C), it means the sum of these; when the resin composition contains a phenolic resin (A), an epoxy resin (B), a maleimide compound (C), and a benzoxazine compound (D), it means the sum of these (A+B+C+D); and when the resin composition contains an elastomer (E) in addition to the phenolic resin (A), an epoxy resin (B), a maleimide compound (C), and a benzoxazine compound (D), it means the sum of these (A+B+C+D+E).

[0072] When the thermosetting resin composition contains an epoxy resin (B), the content of the epoxy resin (B) is preferably 10 to 80 mass% and more preferably 20 to 60 mass% based on the total amount of resin components in the resin composition. When the content of the epoxy resin (B) is 10 mass% or more based on the total amount of resin components in the resin composition, a decrease in adhesive strength in a cured product of the resin composition can be suppressed. When the content of the epoxy resin (B) is 80 mass% or less based on the total amount of resin components in the resin composition, a decrease in glass transition temperature (Tg) can be suppressed. Furthermore, a prepreg with a low thermal expansion coefficient can be more reliably obtained.

[0073] When the thermosetting resin composition contains a maleimide compound (C), the content of the maleimide compound (C) is preferably 15 to 75 mass% and more preferably 30 to 50 mass% based on the total amount of resin components in the resin composition. When the content of the maleimide compound (C) is 15 mass% or more based on the total amount of resin components in the resin composition, a prepreg having a low thermal expansion coefficient can be more reliably obtained. When the content of the maleimide compound (C) is 75 mass% or less based on the total amount of resin components in the resin composition, a decrease in adhesive strength in a cured product of the resin composition can be suppressed.

[0074] When the thermosetting resin composition contains a benzoxazine compound (D), the content of the benzoxazine compound (D) is preferably 5 to 50 mass% and more preferably 10 to 30 mass% based on the total amount of resin components in the resin composition. When the content of the benzoxazine compound (D) is 5 mass% or more based on the total amount of resin components in the resin composition, a decrease in adhesive strength in a cured product of the resin composition can be suppressed. When the content of the benzoxazine compound (D) is 50 mass% or less based on the total amount of resin components in the resin composition, a prepreg with a low thermal expansion coefficient can be more reliably obtained.

[0075] When the thermosetting resin composition contains a maleimide compound (C) and an allyl group-containing benzoxazine compound (D-1), the mass ratio (D-1 / C) of the allyl group-containing benzoxazine compound (D-1) to the maleimide compound (C) is preferably 0.3 to 1.0, more preferably 0.35 to 0.8. When the mass ratio (D-1 / C) is 0.3 or more, a decrease in adhesive strength to a metal layer (e.g., copper foil) can be suppressed. When the mass ratio (D-1 / C) is 1.0 or less, a decrease in glass transition temperature (Tg) can be suppressed.

[0076] When the thermosetting resin composition contains an elastomer (E), the content of the elastomer (E) is preferably 5 to 40 mass% and more preferably 10 to 30 mass% based on the total amount of resin components in the resin composition. When the content of the elastomer (E) is 5 mass% or more based on the total amount of resin components in the resin composition, a prepreg with a low thermal expansion coefficient can be more reliably obtained. When the content of the elastomer (E) is 40 mass% or less based on the total amount of resin components in the resin composition, moldability can be improved.

[0077] When the thermosetting resin composition contains an inorganic filler (F), the content of the inorganic filler (F) is preferably 80 to 180 parts by mass, and more preferably 100 to 150 parts by mass, per 100 parts by mass of the resin components in the resin composition (excluding the inorganic filler (F) in the resin composition). By having the content of the inorganic filler (F) be 80 to 180 parts by mass per 100 parts by mass of the resin components in the resin composition, a prepreg with a low thermal expansion coefficient can be more reliably obtained. Furthermore, deterioration of moldability can be suppressed.

[0078] The content of the thermosetting resin composition in the prepreg of this embodiment is preferably 35 to 80 mass % relative to the total amount of the prepreg, and more preferably 40 to 75 mass %. By having the content of the thermosetting resin composition in the prepreg of 35 to 80 mass % relative to the total amount of the prepreg, the prepreg of this embodiment can more reliably obtain the effects described above (low dielectric properties, low coefficient of thermal expansion).

[0079] (Other Components) The resin composition may contain components other than the above-described components (other components) within the scope of not impairing the effects of the present invention. Examples of other components include organic components other than the above components (A) to (E), flame retardants, reaction initiators, curing accelerators, catalysts, polymerization retarders, polymerization inhibitors, dispersants, leveling agents, coupling agents, defoamers, antioxidants, heat stabilizers, antistatic agents, UV absorbers, dyes, pigments, and additives such as lubricants.

[0080] As described above, the resin composition according to this embodiment may contain an organic component other than the components (A) to (E). The organic component may be, for example, a compound that reacts with at least one of the components (A) to (E), or a compound that does not react with the components (A) to (E). Specific examples of the organic component include cyanate ester compounds and active ester compounds.

[0081] As described above, the resin composition of this embodiment may contain a reaction initiator. The reaction initiator is not particularly limited as long as it can accelerate the curing reaction of the resin composition, and examples thereof include peroxides and organic azo compounds. Examples of peroxides include α,α'-di(t-butylperoxy)diisopropylbenzene (PBP), 2,5-dimethyl-2,5-di(t-butylperoxy)-3-hexyne, and benzoyl peroxide. Examples of organic azo compounds include azobisisobutyronitrile. Furthermore, if necessary, a metal carboxylate or the like can be used in combination. This can further accelerate the curing reaction. The reaction initiators may be used alone or in combination of two or more.

[0082] As described above, the resin composition according to this embodiment may contain a curing accelerator. The curing accelerator is not particularly limited as long as it can accelerate the curing reaction of the resin composition. Specific examples of the curing accelerator include imidazoles and their derivatives, organophosphorus compounds, amines such as secondary amines and tertiary amines, quaternary ammonium salts, organoboron compounds, and metal soaps. Examples of the imidazoles include 2-ethyl-4-methylimidazole (2E4MZ), 2-methylimidazole, 2-phenyl-4-methylimidazole, 2-phenylimidazole, and 1-benzyl-2-methylimidazole. Examples of the organophosphorus compounds include triphenylphosphine, diphenylphosphine, phenylphosphine, tributylphosphine, and trimethylphosphine. Examples of the amines include dimethylbenzylamine, triethylenediamine, triethanolamine, and 1,8-diaza-bicyclo(5,4,0)undecene-7 (DBU). Examples of the quaternary ammonium salts include tetrabutylammonium bromide. Examples of the organoboron compounds include tetraphenylboron salts such as 2-ethyl-4-methylimidazole tetraphenylborate, and tetra-substituted phosphonium tetra-substituted borates such as tetraphenylphosphonium ethyltriphenylborate. The metal soap refers to a fatty acid metal salt, and may be either a linear fatty acid metal salt or a cyclic fatty acid metal salt. Specific examples of the metal soap include linear fatty acid metal salts and cyclic fatty acid metal salts having 6 to 10 carbon atoms. More specifically, examples of the metal soap include aliphatic metal salts composed of linear fatty acids such as stearic acid, lauric acid, ricinoleic acid, and octylic acid, or cyclic fatty acids such as naphthenic acid, and metals such as lithium, magnesium, calcium, barium, copper, and zinc. Examples of the metal soap include zinc octylate. The curing accelerators may be used alone or in combination of two or more.

[0083] [Glass Cloth] The glass cloth included in the prepreg of this embodiment contains SiO ２ 45 to 55 mass% of Al ２ O ３ 20 to 30 mass %, MgO 3.0 mass % or less, and P ２ O ５ The glass cloth contains 10 to 15 mass % of the above.

[0084] By using such glass cloth, the prepreg of this embodiment can have extremely excellent low dielectric properties and a low coefficient of thermal expansion.

[0085] In the glass cloth of this embodiment, SiO ２ If the content of SiO is less than 45% by mass, it becomes difficult to obtain sufficiently low dielectric properties, and if it exceeds 55% by mass, the viscosity increases during spinning, making it difficult to form fibers. ２ The content is 47 to 53 mass %.

[0086] In the glass cloth of this embodiment, Al ２ O ３ If the content of Al is less than 20% by mass, the water resistance deteriorates, and if it exceeds 30% by mass, the spinnability deteriorates and the dielectric constant increases. ２ O ３ The content is 22 to 28 mass %.

[0087] In the glass cloth of this embodiment, if the MgO content exceeds 3 mass%, the water resistance deteriorates and it is difficult to obtain sufficiently low dielectric properties. The lower limit of the MgO content is not particularly limited, but from the viewpoint of uniformity of the glass fibers, it is preferably 0.5% or more. The MgO content relative to the total amount of the glass cloth is more preferably 0.5 to 2.8 mass%.

[0088] In the glass cloth of this embodiment, P ２ O ５ When the amount of Al is less than 10 mass %, ２ O ３ If the content of P exceeds 15% by mass, the water resistance and weather resistance may be deteriorated.２ O ５ The content is 10 to 14 mass %.

[0089] In addition to the above components, the glass cloth of the present embodiment may contain about 0.01 to 0.05 mass % of CaO. When the glass cloth contains CaO in this range, it is possible to improve the water resistance and improve the manufacturability of the glass cloth by reducing the melt viscosity of the molten glass.

[0090] The glass cloth of this embodiment is Na ２ The glass cloth may contain 0.01 to 5 mass % of O. ２ By including O, it is possible to further lower the dielectric loss tangent (Df) and also to reduce the melt viscosity of the molten glass, thereby improving the productivity of the glass cloth.

[0091] Furthermore, the glass cloth of this embodiment contains Li ２ O and / or K ２ The total content of these elements relative to the total amount of the glass cloth is preferably in the range of 0.03 to 0.15 mass%, more preferably in the range of 0.04 to 0.10 mass%. ２ O and / or K ２ It is believed that the inclusion of O can reduce the melt viscosity of the molten glass while maintaining a low dielectric constant, thereby improving the manufacturability of the glass cloth.

[0092] The glass cloth of this embodiment is made of Fe ２ O ３ The glass cloth may contain about 0.01 to 2 mass % of Fe. ２ O ３ By including the above, it is possible to suppress coloration of the glass cloth, while improving the degassing properties of the molten glass, thereby improving the productivity of the glass cloth.

[0093] The glass cloth of the present embodiment may contain ZnO in an amount of about 0.01 to 10 mass %. When the glass cloth contains ZnO in this range, thermal expansion can be suppressed.

[0094] The glass cloth of this embodiment is ZrO ２ The glass cloth may contain ZrO in an amount of 0.01 to 0.10 mass %. ２ By including the amount in this range, the alkali resistance of the glass cloth can be improved.

[0095] On the other hand, the glass cloth of this embodiment is B ２ O ３ , F ２ and TiO ２ Preferably, the glass cloth is substantially free of these (i.e., the content is less than 0.01% by mass), and more preferably completely free of these (i.e., the content is 0% by mass). By substantially not including these, the acid resistance of the glass cloth can be improved while maintaining a high elastic modulus of the glass cloth.

[0096] The content of each of the above components in the glass cloth of this embodiment can be measured using an X-ray fluorescence analyzer. Specifically, the content can be measured by irradiating Rh X-rays in a vacuum atmosphere with an analysis diameter of 20 mm. Alternatively, the content can be measured by ICP emission spectroscopy.

[0097] The glass cloth of the present embodiment may be a surface-treated glass cloth, and as the surface treatment agent, for example, a silane coupling agent having a functional group such as a vinyl group, a styryl group, a methacryl group, an acrylic group, or a phenylamino group can be preferably used.

[0098] The glass cloth of this embodiment is preferably a glass cloth that has been further subjected to flattening processing. Specific examples of flattening processing include a method in which the glass cloth is continuously pressed with a press roll at an appropriate pressure to compress the yarns into a flat shape. The thickness of the glass cloth of this embodiment is not particularly limited, and glass cloths of, for example, about 0.02 to 0.1 mm can be used without any particular limitations.

[0099] The proportion of the glass cloth relative to the total amount of the prepreg of this embodiment is preferably about 20 to 65 mass %. By including the glass cloth at such a content, the prepreg of this embodiment can more reliably obtain the effects described above. A more preferable proportion of the glass cloth is 25 to 60 mass %.

[0100] [Method of Producing Prepreg] Next, a method of obtaining the prepreg of this embodiment will be described. Fig. 1 is a schematic cross-sectional view showing an example of a prepreg 1 according to an embodiment of the present invention.

[0101] 1, the prepreg 1 according to this embodiment comprises the thermosetting resin composition or a semi-cured product of the thermosetting resin composition 2, and glass cloth 3. This prepreg 1 comprises the thermosetting resin composition or the semi-cured product of the thermosetting resin composition 2, and the glass cloth 3 present in the thermosetting resin composition or the semi-cured product of the thermosetting resin composition 2.

[0102] In this embodiment, the semi-cured product refers to a thermosetting resin composition that has been partially cured to the extent that it can be further cured. That is, the semi-cured product refers to a thermosetting resin composition that has been semi-cured (B-staged). For example, when a thermosetting resin composition is heated, the viscosity initially gradually decreases, then curing begins, and then curing begins and the viscosity gradually increases. In such a case, the semi-cured state can be exemplified by the state between when the viscosity begins to increase and when the composition is completely cured.

[0103] Furthermore, the prepreg obtained using the thermosetting resin composition according to this embodiment may include a semi-cured product of the thermosetting resin composition as described above, or may include the uncured thermosetting resin composition itself. That is, it may be a prepreg including a semi-cured product of the thermosetting resin composition (the thermosetting resin composition in B stage) and glass cloth, or a prepreg including the thermosetting resin composition before curing (the thermosetting resin composition in A stage) and glass cloth. The thermosetting resin composition or the semi-cured product of the thermosetting resin composition may be obtained by drying or heat-drying the thermosetting resin composition.

[0104] When producing a prepreg, the thermosetting resin composition 2 is often prepared in the form of a varnish and used to impregnate the glass cloth 3, which is the substrate for forming the prepreg. That is, the thermosetting resin composition 2 is usually often a resin varnish prepared in the form of a varnish. Such a varnish-like thermosetting resin composition (resin varnish) can be obtained, for example, by the following method. The thermosetting resin composition can be obtained by mixing the phenolic resin (A), at least one of the epoxy resin (B) and the maleimide compound (C), and, if necessary, other resin components (such as the benzoxazine compound (D) and the elastomer (E)), and then adding and mixing the inorganic filler (F) if necessary.

[0105] First, the components of the thermosetting resin composition that are soluble in an organic solvent, i.e., the phenolic resin (A), at least one of the epoxy resin (B) and the maleimide compound (C), and optionally other resin components (e.g., the benzoxazine compound (D) and the elastomer (E)), are added to an organic solvent and dissolved. Heating may be performed as needed. Subsequently, optional components that are insoluble in the organic solvent (e.g., the inorganic filler (F)) are added and dispersed using a disperser or the like until a predetermined dispersion state is achieved, thereby preparing a varnish-like thermosetting resin composition. The organic solvent used here is not particularly limited as long as it dissolves the radical polymerizable compound and the like and does not inhibit the curing reaction. Specific examples include toluene and methyl ethyl ketone (MEK).

[0106] The method for producing the prepreg 1 is not particularly limited, but includes, for example, a method in which a thermosetting resin composition 2 prepared in a varnish form is impregnated into a glass cloth 3, followed by drying. The thermosetting resin composition 2 is impregnated into the glass cloth 3 by immersion, coating, or the like. Impregnation can be repeated multiple times as necessary. In this case, by repeating the impregnation using multiple resin compositions with different compositions and concentrations, it is possible to adjust the final composition and impregnation amount to the desired one.

[0107] The glass cloth 3 impregnated with the thermosetting resin composition (resin varnish) 2 is heated under desired conditions, for example, at 80°C to 180°C for 1 minute to 10 minutes. The heating provides a prepreg 1 in an uncured (A-stage) or semi-cured (B-stage) state. The heating also volatilizes the organic solvent from the resin varnish, reducing or eliminating the organic solvent.

[0108] The prepreg of this embodiment has both low dielectric properties and a low coefficient of thermal expansion. Therefore, a wiring board having an insulating layer formed using the prepreg of this embodiment has excellent low dielectric properties and is less prone to warping. Therefore, the prepreg of this embodiment can be suitably used when forming insulating layers provided in metal-clad laminates and wiring boards.

[0109] <Metal-clad laminate> FIG. 2 is a schematic cross-sectional view showing an example of a metal-clad laminate 11 according to this embodiment.

[0110] As shown in FIG. 2, the metal-clad laminate 11 is composed of an insulating layer 12 containing a cured product of the prepreg 1 shown in FIG. 1 and a metal foil 13 laminated together with the insulating layer 12. That is, the metal-clad laminate 11 has an insulating layer 12 containing a cured product of a thermosetting resin composition and a metal foil 13 provided on the insulating layer 12. The insulating layer 12 may be composed of a cured product of the thermosetting resin composition or a cured product of the prepreg. The thickness of the metal foil 13 varies depending on the performance required of the final wiring board and is not particularly limited. The thickness of the metal foil 13 can be appropriately set depending on the desired purpose, and is preferably, for example, 0.2 to 70 μm. Examples of the metal foil 13 include copper foil and aluminum foil. When the metal foil is thin, it may be a carrier-attached copper foil equipped with a release layer and a carrier to improve handling.

[0111] The method for producing the metal-clad laminate 11 is not particularly limited as long as it can produce the metal-clad laminate 11. Specifically, a method for producing the metal-clad laminate 11 using a prepreg 1 can be used. Examples of such a method include stacking one or more prepregs 1, placing a metal foil 13 such as copper foil on both sides or one side of the prepreg 1, and then heat-pressing and molding the metal foil 13 and the prepreg 1 to form an integrated laminate, thereby producing a double-sided or single-sided metal foil-clad laminate 11. That is, the metal-clad laminate 11 can be obtained by laminating the metal foil 13 on the prepreg 1 and then heat-pressing and molding the laminate. The heat-pressing conditions can be appropriately set depending on the thickness of the metal-clad laminate 11 to be produced, the type of composition of the prepreg 1, and the like. For example, the temperature can be 170 to 230°C, the pressure can be 3 to 5 MPa, and the time can be 60 to 150 minutes.

[0112] <Wiring Board> FIG. 3 is a schematic cross-sectional view showing an example of a wiring board 21 according to this embodiment.

[0113] 3, wiring board 21 according to this embodiment is composed of insulating layer 12, which is formed by curing prepreg 1 shown in FIG. 1, and wiring 14, which is laminated together with insulating layer 12 and formed by partially removing metal foil 13. Insulating layer 12 is composed of the cured product of the prepreg.

[0114] The method for manufacturing the wiring board 21 is not particularly limited as long as it can manufacture the wiring board 21. Specific examples include a method of manufacturing the wiring board 21 using the prepreg 1. Examples of this method include a method of manufacturing the wiring board 21 in which wiring is provided as a circuit on the surface of the insulating layer 12 by etching the metal foil 13 on the surface of the metal-clad laminate 11 manufactured as described above. That is, the wiring board 21 is obtained by forming a circuit by partially removing the metal foil 13 on the surface of the metal-clad laminate 11. In addition to the above methods, examples of the method for forming a circuit include circuit formation by a semi-additive process (SAP) or a modified semi-additive process (MSAP).

[0115] Metal-clad laminates and wiring boards having an insulating layer containing a cured product of the prepreg of this embodiment have the same advantages as the prepreg described above, and are therefore useful in industrial applications.

[0116] As described above, this specification discloses various aspects of the technology, but the main technologies among them are summarized below.

[0117] The prepreg in a first aspect comprises a thermosetting resin composition or a semi-cured product of the thermosetting resin composition, and glass cloth, wherein the thermosetting resin composition contains a phenolic resin (A) and at least one of an epoxy resin (B) and a maleimide compound (C), and the glass cloth contains SiO ２ 45 to 55 mass% of Al ２ O ３ 20 to 30 mass %, MgO 3.0 mass % or less, P ２ O ５ Contains 10 to 15 mass % of

[0118] In a second aspect, in the prepreg of the first aspect, the content of the phenolic resin (A) in the thermosetting resin composition is 0.1 to 60 mass% with respect to the total amount of resin components in the thermosetting resin composition.

[0119] A prepreg according to a third aspect is the prepreg according to the first or second aspect, wherein the thermosetting resin composition further contains a benzoxazine compound (D).

[0120] The prepreg in a fourth aspect is the prepreg in any one of the first to third aspects, wherein the thermosetting resin composition comprises an elastomer (E) including at least one of a high molecular weight material (E-1) having a weight average molecular weight of 10,000 or more and 900,000 or less, and a core-shell rubber (E-2).

[0121] A prepreg in a fifth embodiment is the prepreg in the fourth embodiment, wherein the polymer (E-1) contains at least one of an acrylic resin and a styrene-based copolymer.

[0122] In a sixth aspect, in the prepreg of the fourth or fifth aspect, the content of the elastomer (E) in the thermosetting resin composition is 5 to 40 mass% with respect to the total amount of resin components in the thermosetting resin composition.

[0123] A seventh aspect of the prepreg is the prepreg of any one of the first to sixth aspects, wherein the thermosetting resin composition further comprises an inorganic filler (F), and the inorganic filler (F) comprises at least one selected from the group consisting of silica particles, aluminum hydroxide particles, talc particles, magnesium hydroxide particles, and boehmite particles.

[0124] In an eighth aspect, in the prepreg of any one of the first to seventh aspects, the content of the thermosetting resin composition in the prepreg is 35 to 80 mass% with respect to the total amount of components in the prepreg.

[0125] A metal-clad laminate according to a ninth aspect includes an insulating layer containing a cured product of the prepreg according to any one of the first to eighth aspects, and a metal layer.

[0126] A wiring board according to a tenth aspect includes an insulating layer containing a cured product of the prepreg according to any one of the first to eighth aspects, and wiring.

[0127] The present invention will be explained in more detail below with reference to examples, but the scope of the present invention is not limited to these examples.

[0128] The present invention will be explained in more detail below with reference to examples, but the scope of the present invention is not limited to these examples.

[0129] First, the components used in preparing the prepreg in this example will be described.

[0130] [Thermosetting Resin Composition] (Phenol Resin (A)) Phenol novolac resin (manufactured by DIC Corporation, product name "TD2090")

[0131] (Epoxy Resin (B)) Epoxy Resin 1: Trisphenolmethane Type Epoxy Resin (manufactured by DIC Corporation, product name "HP-7241") Epoxy Resin 2: Multifunctional Epoxy Resin Having a Biphenylene Structure (manufactured by Nippon Kayaku Co., Ltd., product name "NC-3500")

[0132] (Maleimide Compound (C)) 3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethane bismaleimide (manufactured by Daiwa Chemical Industry Co., Ltd., product name "BMI-5100")

[0133] (Benzoxazine compound (D)) Represented by the formula (3), R ３ and R ４ is an allyl group, Y is a methylene group, and b and c are 1 (manufactured by Shikoku Chemicals Corporation, product name "ALP-d")

[0134] (Elastomer (E)) Elastomer 1 (acrylic elastomer): epoxy-modified acrylic resin (manufactured by Nagase ChemteX Corporation, product name "PASR-001", weight-average molecular weight Mw: 500,000) Elastomer 2: core-shell rubber (manufactured by Mitsubishi Chemical Corporation, product name "SRK200A", core: silicone / acrylic copolymer, shell: acrylonitrile / styrene, D ５０ : 0.15 μm)

[0135] (Inorganic filler (F)) Silica particles: phenylaminosilane surface-treated spherical silica (manufactured by Admatechs Co., Ltd., product name "SC2500-SXJ")

[0136] (Curing accelerator) 2-ethyl-4-methylimidazole (manufactured by Shikoku Chemicals Corporation, product name "2E4MZ")

[0137] (Reaction initiator) Organic peroxide: PBP (1,3-bis(butylperoxyisopropyl)benzene; product name "Perbutyl P" manufactured by NOF Corporation)

[0138] [Glass Cloth] (Glass Cloths 1 to 3) Three types of glass cloths 1 to 3 (thickness: 0.1 mm) having the compositions shown below were prepared. Glass cloth 1 corresponds to conventional T-glass, and glass cloth 2 corresponds to conventional S-glass. Glass cloth 1: T-glass manufactured by Nitto Boseki Co., Ltd., Cross Style 2118 (SiO ２ :66% by mass, Al ２ O ３ : 25 mass%, MgO: 7.3 mass%, and P ２ O ５ : 0 mass%) Glass cloth 2: S3 glass, Cross Style 2118 (SiO ２ :66% by mass, Al ２ O ３ : 25 mass%, MgO: 6.1 mass%, and P ２ O ５ : 0.003% by mass) Glass cloth 3: V-glass, Cross Style 2118 (SiO ２ :50% by mass, Al ２ O ３ : 25% by mass, MgO: 2.3% by mass, and P２ O ５ :12% by mass)

[0139] [Examples 1 to 3 and Comparative Examples 1 to 5] (Preparation of Evaluation Samples) First, a resin varnish was prepared. The components other than the inorganic filler were mixed to the composition (parts by mass) shown in Tables 1 and 2, with methyl ethyl ketone (MEK) added so that the solids concentration was 40 to 50% by mass. The resulting mixture was stirred for 60 minutes. Thereafter, the inorganic filler was added to the resulting mixture to the composition (parts by mass) shown in Tables 1 and 2, and dispersed using a bead mill. This resulted in a varnish-like resin composition (varnish).

[0140] Next, the varnishes obtained above were impregnated into glass cloths shown in Tables 1 and 2. Specifically, Glass Cloth 3 was used in Examples 1 to 3, Glass Cloth 2 in Comparative Examples 1 and 4, and Glass Cloth 1 in Comparative Examples 2, 3, and 5. Prepregs were then produced by heating and drying at 130°C for 3 minutes. The content of the components that constitute the resin by the curing reaction relative to the prepreg (resin content) was adjusted to approximately 45% by mass. In other words, the content of glass cloth relative to the total amount of prepreg was adjusted to 55% by mass. Furthermore, the thickness after curing was adjusted to 103 μm.

[0141] Next, the obtained prepreg was used to obtain an evaluation sample (metal-clad laminate). First, 10 sheets of the obtained prepreg were stacked, and 12 μm thick copper foil (3EC-VLP manufactured by Mitsui Mining & Smelting Co., Ltd.) was placed on both sides. This was used as a pressure body, and heated to a temperature of 220 ° C. at a temperature increase rate of 3 ° C. / min, and heated and pressed at 220 ° C. for 120 minutes under a pressure of 4 MPa to obtain an evaluation substrate (metal-clad laminate) with copper foil bonded to both sides and a resin layer (insulating layer) thickness of approximately 1030 μm.

[0142] Using the evaluation substrate prepared as described above, evaluation test 1 was carried out by the following method.

[0143] [Evaluation Tests] In the evaluation tests of the dielectric properties (dielectric constant Dk) and the thermal expansion coefficient, an unclad board (cured prepreg, thickness approximately 1030 μm) obtained by removing the copper foil by etching from a copper-clad laminate made of 10 layers of prepreg was used as an evaluation sample.

[0144] (Dielectric Properties (Dielectric Constant: Dk)) The dielectric constant (Dk) of the evaluation sample at 10 GHz was measured by a cavity resonator perturbation method. Specifically, the dielectric constant of the evaluation substrate at 10 GHz was measured using a network analyzer (N5230A manufactured by Keysight Technologies, Inc.).

[0145] (Coefficient of thermal expansion: CTE (50 to 260°C)) The evaluation sample was used as a test piece (size: 10 mm x 3.5 mm), and the coefficient of thermal expansion in the plane direction (Y direction) of the evaluation substrate at a temperature below the glass transition temperature of the cured resin composition was measured by the TMA method (thermo-mechanical analysis). Specifically, the measurement was performed in compression mode using a TMA device ("TMA / SS7100" manufactured by SII NanoTechnology Inc.). In order to eliminate the influence of thermal distortion of the test piece, the test piece was heated from 30°C to 320°C at a heating rate of 10°C / min with a load of 10 g applied in the Y direction, and then cooled to room temperature. Thereafter, the test piece was heated from 30°C to 320°C at a heating rate of 10°C / min with a load of 10 g applied in the Y direction. A temperature displacement chart was obtained during this heating period. From the temperature change chart obtained at this time, the average coefficient of thermal expansion (CTE) from 50 to 260° C. was calculated. The lower this average coefficient of thermal expansion, the more preferable the result.

[0146] The results of the above evaluations are shown in Tables 1 and 2.

[0147]

[0148]

[0149] [Discussion] As can be seen from Tables 1 and 2, it was confirmed that the dielectric properties (dielectric constant) and thermal expansion coefficient were both low in the prepregs of Examples 1 to 3, which used the resin composition of this embodiment and the glass cloth. In Example 2, a high molecular weight material having a weight average molecular weight of 10,000 or more and 900,000 or less and a core-shell rubber were included as the elastomer (E), and it was also confirmed that in this case, the dielectric properties (dielectric constant) and thermal expansion coefficient were both low.

[0150] On the other hand, the prepregs of Comparative Examples 1 to 3, which did not use the glass cloth of this embodiment, were inferior to Examples 1 and 2 in at least one of low dielectric properties (low relative dielectric constant) and low thermal expansion coefficient. Also, the prepregs of Comparative Examples 4 and 5, which did not use the glass cloth of this embodiment, were inferior to Example 3 in at least one of low dielectric properties (low relative dielectric constant) and low thermal expansion coefficient.

[0151] This application is based on Japanese Patent Application No. 2024-56464, filed on March 29, 2024, the contents of which are incorporated herein by reference.

[0152] In order to express the present invention, the present invention has been properly and sufficiently described above through the embodiments with reference to the drawings, but it should be recognized that those skilled in the art can easily change and / or improve the above-mentioned embodiments. Therefore, unless the changes or improvements made by those skilled in the art are at a level that causes departure from the scope of the claims described in the claims, such changes or improvements are interpreted as being included in the scope of the claims.

[0153] According to the present invention, it is possible to provide a prepreg having excellent low dielectric properties and a low coefficient of thermal expansion, as well as a metal-clad laminate and a wiring board using the same.

Claims

1. A thermosetting resin composition or a semi-cured product of the thermosetting resin composition, and glass cloth, wherein the thermosetting resin composition contains a phenolic resin (A) and at least one of an epoxy resin (B) and a maleimide compound (C), and the glass cloth contains SiO ２ 45 to 55 mass% of Al ２ O ３ 20 to 30 mass %, MgO 3.0 mass % or less, P ２ O ５ A prepreg comprising 10 to 15 mass% of the above.

2. The prepreg according to claim 1, wherein the content of the phenolic resin (A) in the thermosetting resin composition is 0.1 to 60 mass % based on the total amount of resin components in the thermosetting resin composition.

3. The prepreg according to claim 1, wherein the thermosetting resin composition further contains a benzoxazine compound (D).

4. The prepreg according to claim 1, wherein the thermosetting resin composition comprises an elastomer (E) containing at least one of a high molecular weight material (E-1) having a weight average molecular weight of 10,000 or more and 900,000 or less, and a core-shell rubber (E-2).

5. The prepreg according to claim 4, wherein the polymer (E-1) contains at least one of an acrylic resin and a styrene copolymer.

6. The prepreg according to claim 4, wherein the content of the elastomer (E) in the thermosetting resin composition is 5 to 40 mass % based on the total amount of resin components in the thermosetting resin composition.

7. The prepreg according to claim 1, wherein the thermosetting resin composition further contains an inorganic filler (F), and the inorganic filler (F) contains at least one selected from the group consisting of silica particles, aluminum hydroxide particles, talc particles, magnesium hydroxide particles, and boehmite particles.

8. The prepreg according to claim 1, wherein the content of the thermosetting resin composition in the prepreg is 35 to 80 mass % based on the total amount of components in the prepreg.

9. A metal-clad laminate comprising an insulating layer containing a cured product of the prepreg according to any one of claims 1 to 8 and a metal layer.

10. A wiring board comprising an insulating layer containing a cured product of the prepreg according to any one of claims 1 to 8 and wiring.

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