Resin composition, prepreg, laminated plate, metal-clad laminated plate, printed wiring board, and semiconductor package

Abstract

Provided is a resin composition exhibiting excellent flame retardancy together with high copper foil peel strength and high desmear resistance. Also provided are a prepreg, a laminated plate, a metal-clad laminated plate, a printed wiring board, and a semiconductor package that are produced using the resin composition. Specifically, the resin composition contains (A) a thermosetting resin and (B) a flame retardant. The flame retardant (B) contains (B1) a phosphorus-based flame retardant having a styrene skeleton.

Description

Resin compositions, prepregs, laminates, metal-clad laminates, printed wiring boards, and semiconductor packages

[0001] The present disclosure relates to a resin composition, a prepreg, a laminate, a metal-clad laminate, a printed wiring board, and a semiconductor package.

[0002] In flame retarding printed wiring board materials, halogen-free materials are often considered to be essential from the viewpoint of environmental issues. Therefore, in recent years, it has often been considered that halogen-free phosphorus-based flame retardants, which are highly effective in improving flame retardancy, are preferable for imparting flame retardancy to printed wiring board materials (see, for example, Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2021-138803

[0004] The manufacture of printed wiring boards involves the formation of vias for connecting layers. Vias are formed by laser processing, drilling, or the like. After the laser processing or drilling, a process to remove residual resin components (so-called desmearing) is typically performed. Because the desmearing is performed on the bottom and wall surfaces of the via, if a large amount of the resin component of the substrate dissolves during the desmearing, the via shape may be significantly deformed. Furthermore, various problems may occur, such as uneven plating coverage due to variations in the wall surface roughness. For this reason, there is a need to reduce the amount of resin component dissolved during the desmearing process. Furthermore, printed wiring boards require peel strength that prevents the printed wiring and the conductor layer constituting the circuit pattern from peeling off, even when the circuit pattern is miniaturized.

[0005] However, the inventors of the present invention have conducted studies and found that increasing the content of the phosphorus-containing flame retardant in order to impart flame retardancy to a printed wiring board material results in insufficient copper foil peel strength and desmear resistance of the printed wiring board, making it difficult to maintain the copper foil peel strength and desmear resistance together with the flame retardancy.

[0006] In view of the above circumstances, the present disclosure has an object to provide a resin composition that exhibits excellent flame retardancy as well as high copper foil peel strength and high desmear resistance, and further an object to provide a prepreg, a laminate, a metal-clad laminate, a printed wiring board, and a semiconductor package produced using the resin composition.

[0007] The present inventors have conducted extensive research to achieve the above-mentioned object, and have found that the above-mentioned object can be achieved by the present disclosure. The present disclosure includes the following embodiments [1] to

[13] . [1] A resin composition containing (A) a thermosetting resin and (B) a flame retardant, wherein the flame retardant (B) includes (B1) a phosphorus-based flame retardant having a styrene skeleton. [2] The resin composition according to the above [1], wherein the component (B1) has two or more styrene skeletons. [3] The resin composition according to the above [1] or [2], wherein the component (B1) has a structural unit represented by the following general formula (B-1): (In the formula, R ｂ１represents an organic group having 1 to 20 carbon atoms.) [4] The resin composition according to any one of [1] to [3] above, wherein the content of the component (B1) is 1 to 25 parts by mass per 100 parts by mass of the total amount of the components (A) and (B). [5] The resin composition according to any one of [1] to [4] above, wherein the component (A) comprises at least one selected from the group consisting of an epoxy resin, a polyimide resin, a maleimide compound, a phenolic resin, a polyphenylene ether resin, a bismaleimide triazine resin, a cyanate resin, an isocyanate resin, a benzoxazine resin, an oxetane resin, an amino resin, an unsaturated polyester resin, an allyl resin, a dicyclopentadiene resin, and a silicone resin. [6] The resin composition according to any one of [1] to [5] above, wherein the component (A) comprises at least one selected from the group consisting of a maleimide compound having one or more N-substituted maleimide groups and derivatives thereof. [7] The resin composition according to any one of [1] to [6] above, wherein the component (A) comprises a siloxane-modified maleimide compound. [8] The resin composition according to any one of [1] to [7] above, further comprising a filler (C). [9] A prepreg comprising a substrate and a semi-cured product of the resin composition according to any one of [1] to [8] above.

[10] A laminate comprising the prepreg according to [9] above.

[11] A metal-clad laminate comprising a metal foil and a cured product of the prepreg according to [9] above.

[12] A printed wiring board comprising the laminate according to

[10] above or the metal-clad laminate according to

[11] above.

[13] A semiconductor package comprising the printed wiring board according to

[12] above and a semiconductor element.

[0008] According to the present disclosure, it is possible to provide a resin composition that exhibits excellent flame retardancy, high copper foil peel strength, and high desmear resistance. Furthermore, it is possible to provide a prepreg, a laminate, a metal-clad laminate, a printed wiring board, and a semiconductor package produced using the resin composition.

[0009] In the numerical ranges described herein, the upper or lower limit of the numerical range may be replaced with a value shown in the examples. Furthermore, the lower and upper limits of a numerical range can be arbitrarily combined with the lower or upper limit of another numerical range. In the expression "AA to BB," the two extreme values ​​AA and BB are included as the lower and upper limits, respectively, of the numerical range. In this specification, for example, "10 or more" means 10 and a value greater than 10, and this also applies when the numerical values ​​differ. Furthermore, for example, "10 or less" means 10 and a value less than 10, and this also applies when the numerical values ​​differ. Furthermore, unless otherwise specified, each component and material exemplified herein may be used alone or in combination of two or more types. In this specification, when multiple substances corresponding to each component are present in the composition, the content of each component in the composition refers to the total amount of the multiple substances present in the composition, unless otherwise specified.

[0010] In the present disclosure, "resin component" refers to all components of the solid content constituting the resin composition, excluding inorganic compounds such as inorganic fillers, which will be described later. In the present disclosure, "solid content" refers to components other than the organic solvent, which will be described later, and components that are liquid at 25°C are also considered to be solid content. The expression "containing XX" described in the present disclosure means that if XX is reactive, XX is contained in a reacted state, or XX is simply contained. Any combination of the items described in the present disclosure is also included in the present disclosure and the present embodiment.

[0011] [Resin Composition] One embodiment of the present invention is a resin composition containing (A) a thermosetting resin and (B) a flame retardant, wherein the flame retardant (B) includes (B1) a phosphorus-based flame retardant having a styrene skeleton. By including (B1) the phosphorus-based flame retardant having a styrene skeleton, the resin composition of this embodiment exhibits excellent flame retardancy, high copper foil peel strength, and high desmear resistance. Each component contained in the resin composition of this embodiment will be described in detail below.

[0012] <(A) Thermosetting Resin> Examples of the (A) component include epoxy resins, polyimide resins, maleimide compounds, phenolic resins, polyphenylene ether resins, bismaleimide triazine resins, cyanate resins, isocyanate resins, benzoxazine resins, oxetane resins, amino resins (such as melamine resins), unsaturated polyester resins, allyl resins, dicyclopentadiene resins, and silicone resins. Among these, the (A) component is preferably at least one selected from the group consisting of epoxy resins, maleimide compounds, phenolic resins, polyphenylene ether resins, cyanate resins, and isocyanate resins, more preferably at least one selected from the group consisting of epoxy resins and maleimide compounds, and even more preferably an epoxy resin and a maleimide compound are used in combination. As the (A) component, one type may be used alone, or two or more types may be used in combination.

[0013] (Epoxy Resin) The epoxy resin is preferably an epoxy resin having two or more epoxy groups in one molecule. Here, epoxy resins are classified into glycidyl ether type epoxy resins, glycidyl amine type epoxy resins, glycidyl ester type epoxy resins, etc. Among these, glycidyl ether type epoxy resins are preferred.

[0004] Epoxy resins are classified into various epoxy resins depending on the difference in their main skeletons, and each of the above types of epoxy resins can be further classified into bisphenol-type epoxy resins such as bisphenol A-type epoxy resins, bisphenol F-type epoxy resins, and bisphenol S-type epoxy resins; alicyclic epoxy resins such as dicyclopentadiene-type epoxy resins; aliphatic chain epoxy resins; novolac-type epoxy resins such as phenol novolac-type epoxy resins, cresol novolac-type epoxy resins, bisphenol A novolac-type epoxy resins, bisphenol F novolac-type epoxy resins, phenol aralkyl novolac-type epoxy resins, and biphenyl aralkyl novolac-type epoxy resins; stilbene-type epoxy resins; naphthalene-skeleton-containing epoxy resins such as naphthol novolac-type epoxy resins and naphthol aralkyl-type epoxy resins; biphenyl-type epoxy resins; xylylene-type epoxy resins; and dihydroanthracene-type epoxy resins. Among these, as the epoxy resin, from the viewpoints of solder heat resistance, electrical insulation reliability, and copper foil peel strength, novolac-type epoxy resins and naphthalene skeleton-containing epoxy resins are preferred, novolac-type epoxy resins are more preferred, and biphenylaralkyl novolac-type epoxy resins are even more preferred.

[0014] The weight-average molecular weight of the epoxy resin may be 200 to 1,000, 250 to 950, or 300 to 900. When the weight-average molecular weight of the epoxy resin is equal to or greater than the lower limit, the epoxy resin tends to have excellent solder heat resistance, while when it is equal to or less than the upper limit, the epoxy resin tends to exhibit low elasticity and flexibility. From the viewpoint of compatibility, the epoxy equivalent of the epoxy resin may be 150 to 500 g / eq, 150 to 450 g / eq, or 200 to 350 g / eq.

[0015] (Maleimide Compound) The maleimide compound preferably includes at least one selected from the group consisting of maleimide compounds having one or more (preferably two or more) N-substituted maleimide groups and derivatives thereof. The maleimide compound having one or more N-substituted maleimide groups is not particularly limited, and examples thereof include aromatic maleimide compounds preferably having one N-substituted maleimide group bonded to an aromatic ring, such as N-phenylmaleimide, N-(2-methylphenyl)maleimide, N-(4-methylphenyl)maleimide, N-(2,6-dimethylphenyl)maleimide, N-(2,6-diethylphenyl)maleimide, N-(2-methoxyphenyl)maleimide, and N-benzylmaleimide; 4,4'-diphenylmethane bismaleimide, bis(4-maleimidophenyl)ether, bis(4-maleimidophenyl)sulfone, 3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethane bismaleimide, 4-methyl-1,3 aromatic bismaleimide compounds preferably having two N-substituted maleimide groups bonded to an aromatic ring, such as 1,2-dimethyl-2,3-dimethyl-4,4-dimethyl-2,4-dimethyl-2,5-dimethyl-1,5 ... Among these, from the viewpoints of compatibility with other resins, copper foil peel strength, solder heat resistance, low thermal expansion, mechanical properties, and the like, aromatic bismaleimide compounds having two N-substituted maleimide groups bonded to an aromatic ring are preferred, with 4,4'-diphenylmethane bismaleimide, 2,2-bis[4-(4-maleimidophenoxy)phenyl]propane, and indan ring-containing aromatic bismaleimide being more preferred, and 2,2-bis[4-(4-maleimidophenoxy)phenyl]propane being even more preferred.In the maleimide compound, it is preferable that the nitrogen atom of each of the "one N-substituted maleimide group preferably bonded to an aromatic ring," "two N-substituted maleimide groups preferably bonded to an aromatic ring," and "three or more N-substituted maleimide groups preferably bonded to an aromatic ring" be bonded to an aromatic ring. Thus, it is preferable that the nitrogen atoms of the N-substituted maleimide groups in the maleimide compound be bonded to each other via a linking group containing an aromatic ring.

[0016] Examples of the derivatives of maleimide compounds include addition reaction products of maleimide compounds having one or more (preferably two or more) N-substituted maleimide groups with amine compounds such as monoamine compounds and diamine compounds. Examples of the monoamine compounds include monoamine compounds having an acidic substituent, such as o-aminophenol, m-aminophenol, p-aminophenol, o-aminobenzoic acid, m-aminobenzoic acid, p-aminobenzoic acid, o-aminobenzenesulfonic acid, m-aminobenzenesulfonic acid, p-aminobenzenesulfonic acid, 3,5-dihydroxyaniline, and 3,5-dicarboxyaniline. Examples of the diamine compound include 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylethane, 4,4'-diaminodiphenylpropane, 2,2'-bis(4,4'-diaminodiphenyl)propane, 3,3'-dimethyl-4,4'-diaminodiphenylmethane, 3,3'-diethyl-4,4'-diaminodiphenylmethane, 3,3'-dimethyl-4,4'-diaminodiphenylethane, 3,3'-diethyl-4,4'-diaminodiphenylethane, 4,4'-diaminodiphenyl ether, Examples of the diaminodiphenyl thioether include 4,4'-dihydroxy-4,4'-diaminodiphenylmethane, 2,2',6,6'-tetramethyl-4,4'-diaminodiphenylmethane, 3,3'-dichloro-4,4'-diaminodiphenylmethane, 3,3'-dibromo-4,4'-diaminodiphenylmethane, 2,2',6,6'-tetrachloro-4,4'-diaminodiphenylmethane, 2,2',6,6'-tetrabromo-4,4'-diaminodiphenylmethane, and siloxane diamine.

[0017] In one preferred embodiment, the maleimide compound derivative is a so-called siloxane-modified maleimide compound, which is an addition reaction product between a maleimide compound having one or more (preferably two or more) N-substituted maleimide groups and a siloxane diamine. The siloxane-modified maleimide compound is preferably an addition reaction product between an aromatic bismaleimide compound having two N-substituted maleimide groups bonded to an aromatic ring and a siloxane diamine, more preferably an addition reaction product between 4,4'-diphenylmethane bismaleimide, 2,2-bis[4-(4-maleimidophenoxy)phenyl]propane, or an indane ring-containing aromatic bismaleimide and a siloxane diamine, and even more preferably an addition reaction product between 2,2-bis[4-(4-maleimidophenoxy)phenyl]propane and a siloxane diamine. The weight average molecular weight (Mw) of the siloxane-modified maleimide compound is not particularly limited, but is preferably 400 to 10,000, more preferably 1,000 to 5,000, even more preferably 1,500 to 4,000, and particularly preferably 2,000 to 3,000.

[0018] (Content of Component (A)) The content of component (A) is preferably 70 to 99 parts by mass, more preferably 75 to 99 parts by mass, even more preferably 75 to 95 parts by mass, and particularly preferably 80 to 95 parts by mass, relative to 100 parts by mass of the total amount of components (A) and (B). When the content of component (A) is equal to or greater than the lower limit, high copper foil peel strength and high solder heat resistance tend to be obtained. On the other hand, when the content of component (A) is equal to or less than the upper limit, the content of component (B) can be increased accordingly, and therefore flame retardancy tends to be good.

[0019] <(B) Flame Retardant> In this embodiment, in order to achieve excellent flame retardancy, high copper foil peel strength, and high desmear resistance, the (B) flame retardant includes (B1) a phosphorus-based flame retardant having a styrene skeleton. The phosphorus-based flame retardant of component (B1) is not particularly limited as long as it has a styrene skeleton. However, from the viewpoints of flame retardancy, copper foil peel strength, and desmear resistance, it is preferably a phosphorus-based flame retardant having two or more styrene skeletons, more preferably a phosphorus-based flame retardant having 2 to 8 styrene skeletons, even more preferably a phosphorus-based flame retardant having 2 to 5 styrene skeletons, and particularly preferably a phosphorus-based flame retardant having 3 or 4 styrene skeletons. It is preferable that component (B1) is a phosphazene compound.

[0020] The component (B1) is not particularly limited, but from the viewpoints of flame retardancy, copper foil peel strength, and desmear resistance, it preferably has a structural unit represented by the following general formula (B-1), more preferably has 1 to 8 structural units represented by the following general formula (B-1) per molecule, even more preferably has 2 to 5 structural units represented by the following general formula (B-1) per molecule, and particularly preferably has 3 or 4 structural units represented by the following general formula (B-1) per molecule. (In the formula, R ｂ１ represents an organic group having 1 to 20 carbon atoms.

[0021] In the general formula (B-1), R ｂ１ Examples of the organic group having 1 to 20 carbon atoms represented by R include an alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, and a group formed by combining these. ｂ１ may have a vinyl group, but may not have a vinyl group. ｂ１ Examples of the alkyl group having 1 to 20 carbon atoms represented by R include a methyl group, an ethyl group, a propyl group, an n-butyl group, a t-butyl group, an n-octyl group, and an n-dodecyl group. The alkyl group having 1 to 20 carbon atoms is preferably an alkyl group having 1 to 10 carbon atoms, and more preferably an alkyl group having 1 to 5 carbon atoms. ｂ１Examples of the aryl group having 6 to 20 carbon atoms represented by R include a phenyl group, a naphthyl group, and an anthryl group. The aryl group having 6 to 20 carbon atoms is preferably an aryl group having 6 to 14 carbon atoms, more preferably an aryl group having 6 to 12 carbon atoms, and even more preferably an aryl group having 6 to 10 carbon atoms. ｂ１ The aryl group having 6 to 20 carbon atoms represented by may or may not have a substituent. Examples of the substituent include a hydroxyl group, an alkyl group having 1 to 5 carbon atoms, and an alkoxyl group having 1 to 5 carbon atoms. ｂ１ Examples of the combination of an alkyl group having 1 to 20 carbon atoms (herein abbreviated as alkyl group) and a substituted or unsubstituted aryl group having 6 to 20 carbon atoms (herein abbreviated as aryl group) shown in the formula (1) include -alkyl group-aryl group, -aryl group-alkyl group, -alkyl group-aryl group-alkyl group, etc. Preferred embodiments of the alkyl group and the aryl group are as described above.

[0022] The structural unit represented by general formula (B-1) is preferably a structural unit represented by the following general formula (B-2) from the viewpoints of flame retardancy, copper foil peel strength, and desmear resistance.

[0023] From the viewpoints of flame retardancy, copper foil peel strength, and desmear resistance, the component (B1) is preferably represented by the following general formula (B-3): (In the formula, n ｂ１ is an integer of 3 or greater.)

[0024] In general formula (B-3), n ｂ１ is an integer of 3 or more, and is preferably an integer of 3 to 8, more preferably an integer of 3 to 5, and even more preferably 3 or 4, from the viewpoints of flame retardancy, copper foil peel strength, and desmear resistance.

[0025] From the viewpoints of flame retardancy, copper foil peel strength, and desmear resistance, the component (B1) is preferably represented by the following general formula (B-4): The flame retardant represented by the following general formula (B-4) is available from Fushimi Pharmaceutical Co., Ltd.

[0026] (Content of Component (B1)) The content of the component (B1) is preferably 1 to 25 parts by mass, more preferably 2 to 20 parts by mass, even more preferably 3 to 18 parts by mass, and particularly preferably 5 to 15 parts by mass, relative to 100 parts by mass of the total amount of the components (A) and (B). When the content of the component (B1) is equal to or greater than the lower limit, there is a tendency for excellent flame retardancy, high copper foil peel strength, and high desmear resistance to be readily exhibited. Furthermore, when the content of the component (B1) is equal to or less than the upper limit, there is a tendency for a decrease in glass transition temperature to be suppressed, and good solder heat resistance to be readily exhibited.

[0027] The resin composition of this embodiment may or may not contain a flame retardant other than the component (B1) as the component (B). Examples of the flame retardant other than the component (B1) include phosphorus-based flame retardants other than the component (B1), such as phosphate ester compounds and phosphaphenanthrene compounds; halogen-based flame retardants; and metal hydrates.

[0028] (Content of Component (B)) The content of the component (B), i.e., the total content, is preferably 1 to 30 parts by mass, more preferably 1 to 25 parts by mass, even more preferably 5 to 25 parts by mass, and particularly preferably 5 to 20 parts by mass, relative to 100 parts by mass of the total amount of the components (A) and (B). When the content of the component (B) is equal to or greater than the lower limit, excellent flame retardancy tends to be easily obtained. On the other hand, when the content of the component (B) is equal to or less than the upper limit, low thermal expansion tends to be achieved.

[0029] When the resin composition of the present embodiment contains a flame retardant other than the component (B1) as the component (B), the content of the flame retardant other than the component (B1) is preferably 20 parts by mass or less, more preferably 10 parts by mass or less, even more preferably 5 parts by mass or less, and particularly preferably 1 part by mass or less, relative to 100 parts by mass of the total amount of the components (A) and (B). There is no particular restriction on the lower limit, but the content may be 0.1 parts by mass or more, or 0.5 parts by mass or more.

[0030] <(C) Filler> The resin composition of this embodiment may further contain a (C) filler. The (C) filler is not particularly limited, but an inorganic filler is preferred from the viewpoint of ensuring low thermal expansion and flame retardancy. Examples of inorganic fillers include silica, alumina, titanium oxide, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, calcium oxide, magnesium oxide, aluminum nitride, aluminum borate whiskers, boron nitride, and silicon carbide. One type of (C) filler may be used alone, or two or more types may be used in combination. Among these, silica is preferred because of its low dielectric constant and low linear expansion coefficient. Examples of silica include synthetic silica synthesized by a wet method or a dry method, crushed silica, and fused silica.

[0031] The filler (C) may be a filler that has been subjected to a coupling treatment. The coupling agent used in the coupling treatment is preferably a silane coupling agent. Examples of the silane coupling agent include aminosilane coupling agents, epoxysilane coupling agents, phenylsilane coupling agents, alkylsilane coupling agents, alkenylsilane coupling agents, alkynylsilane coupling agents, and silicone oligomer coupling agents. These may be used alone or in combination of two or more.

[0032] The average particle size of component (C) is preferably 0.1 to 2.5 μm, more preferably 0.2 to 1.5 μm, and even more preferably 0.3 to 0.8 μm. If the average particle size of component (C) is at least the lower limit, the filler is easily dispersed in the resin varnish, and aggregation tends to be less likely to occur. If the average particle size is at or below the upper limit, sedimentation of component (C) in the resin varnish tends to be less likely to occur. Here, the average particle size in this embodiment refers to the particle size at the point corresponding to 50% volume when a cumulative frequency distribution curve of particle sizes is calculated, assuming the total volume of the particles to be 100%, and can be measured using a particle size distribution analyzer using a laser diffraction scattering method, for example.

[0033] (Content of Component (C)) When the resin composition of this embodiment contains component (C), the content of component (C) is not particularly limited, but is preferably 30 to 300 parts by mass, more preferably 50 to 250 parts by mass, even more preferably 70 to 200 parts by mass, particularly preferably 100 to 200 parts by mass, and most preferably 130 to 170 parts by mass, relative to 100 parts by mass of the total amount of component (A) and component (B). If the content of component (C) is equal to or greater than the lower limit, low thermal expansion properties tend to be improved and sufficient solder heat resistance tends to be obtained. If the content of component (C) is equal to or less than the upper limit, the heat resistance and the like of component (A) and the flame retardancy of component (B) tend to be easily obtained.

[0034] <(D) Curing Accelerator> The resin composition of this embodiment may contain a (D) curing accelerator. The (D) component may be used alone or in combination of two or more. For example, when the (A) component contains an epoxy resin, the (D) component is not particularly limited, but preferably contains one or more selected from the group consisting of amine compounds and imidazole-based compounds, and more preferably contains an imidazole-based compound. Examples of the amine compound include dicyandiamide, diaminodiphenylethane, and guanylurea. Examples of the imidazole-based compound include 2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-phenylimidazolium trimellitate, benzimidazole, and isocyanate-masked imidazole (for example, an addition reaction product of hexamethylene diisocyanate resin and 2-ethyl-4-methylimidazole).

[0035] (Content of Component (D)) When the resin composition of the present embodiment contains the component (D), the content of the component (D) is not particularly limited, but is preferably 0.01 to 10 parts by mass, more preferably 0.03 to 2 parts by mass, and even more preferably 0.1 to 1 part by mass, relative to 100 parts by mass of the total amount of the component (A) and the component (B).

[0036] <Other Components> The resin composition of this embodiment may contain, as necessary, a crosslinking agent, a flame retardant aid, a rubber-based elastomer, conductive particles, a coupling agent, a flow modifier, an antioxidant, a heat stabilizer, an antistatic agent, a pigment, a leveling agent, an antifoaming agent, an ion trapping agent, or the like. Known components can be used as these other components. When the resin composition of this embodiment contains the other components, the content thereof is preferably 0.1 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, and even more preferably 0.1 to 3 parts by mass, relative to 100 parts by mass of the total amount of the component (A) and the component (B).

[0037] The resin composition of this embodiment may be dissolved or dispersed in an organic solvent, or in the form of a so-called "resin varnish." Hereinafter, a resin composition containing an organic solvent may be referred to as a "resin varnish." Examples of the organic solvent include ketone-based solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; aromatic hydrocarbon-based solvents such as toluene and xylene; ester-based solvents such as methoxyethyl acetate, ethoxyethyl acetate, butoxyethyl acetate, and ethyl acetate; amide-based solvents such as N-methylpyrrolidone, formamide, N-methylformamide, and N,N-dimethylacetamide; and alcohol-based solvents such as methanol, ethanol, ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, propylene glycol monopropyl ether, and dipropylene glycol monopropyl ether. One type of organic solvent may be used alone, or two or more types may be used in combination. The solid content concentration in the varnish is preferably from 10 to 70% by mass, more preferably from 20 to 60% by mass, and even more preferably from 35 to 60% by mass.

[0038] [Prepreg] The prepreg of this embodiment includes a substrate and a semi-cured product of the resin composition of this embodiment. Here, the expression "including a substrate and a semi-cured product of the resin composition of this embodiment" means that the resin composition is impregnated into the substrate and semi-cured (B-staged). Here, B-staging in this specification refers to bringing the resin composition into a B-stage state as defined in JIS K6900 (1994). The prepreg can be produced, for example, by impregnating or coating the substrate with the varnish-like resin composition of this embodiment, and then heating and drying the resin composition to semi-cure (B-stage).

[0039] The following hot melt method or solvent method can be used to impregnate or coat a substrate with a resin composition. The hot melt method is a method in which the resin composition does not contain an organic solvent, and (1) the resin composition is first coated on coated paper that has good peelability from the resin composition and then laminated onto the substrate, or (2) the resin composition is directly coated onto the substrate using a die coater. On the other hand, the solvent method is a method in which the resin composition contains an organic solvent, and the substrate is immersed in the resulting resin composition to impregnate the substrate with the resin composition, followed by drying.

[0040] As the substrate, a fibrous substrate such as a woven fabric or a nonwoven fabric is usually used, with a woven fabric being preferred. Furthermore, the substrate is preferably a sheet-like fibrous substrate. Examples of materials for the fibrous substrate include inorganic fibers such as glass, alumina, asbestos, boron, silica alumina glass, silica glass, Tyranno, silicon carbide, silicon nitride, and zirconia; organic fibers such as aramid, polyether ether ketone, polyetherimide, polyethersulfone, carbon, and cellulose; and mixtures thereof. Among these, inorganic fibers are preferred, and glass fibers are more preferred. In other words, the substrate is preferably a woven fabric of glass fibers, i.e., glass cloth. The thickness of the substrate is preferably 5 to 200 μm, but may be 10 to 100 μm, or may be 20 to 50 μm. By setting the thickness of the substrate to the above upper limit or less, dimensional changes due to temperature changes, moisture absorption, and the like during the manufacturing process can be reduced.

[0041] The conditions for producing the prepreg are not particularly limited, but in the case of a solvent method, it is preferable that 80% by mass or more of the organic solvent used in the resin varnish has evaporated in the resulting prepreg. The drying temperature after impregnating or coating the substrate with the resin composition is preferably 80 to 180°C, more preferably 100 to 140°C, and the drying time is appropriately set taking into account the gelation time of the resin composition.

[0042] The solid content of the resin composition in the prepreg of this embodiment is not particularly limited, but is preferably 30 to 90% by mass, more preferably 35 to 80% by mass, even more preferably 40 to 70% by mass, and particularly preferably 45 to 60% by mass. If the solid content of the resin composition in the prepreg is within this range, good moldability tends to be obtained when the prepreg is formed into a laminate.

[0043] The thickness of the prepreg of this embodiment is not particularly limited, and may be 10 to 200 μm, 10 to 150 μm, or 10 to 100 μm.

[0044] [Laminate, Metal-Clad Laminate] The laminate of this embodiment is a laminate including a cured product of the prepreg of this embodiment. Here, the laminate of this embodiment is also a laminate including a cured product of the resin composition of this embodiment. The metal-clad laminate of this embodiment is also a metal-clad laminate including a metal foil and a cured product of the prepreg of this embodiment. Here, the metal-clad laminate of this embodiment is also a metal-clad laminate including a metal foil and a cured product of the resin composition of this embodiment. The metal-clad laminate can be produced, for example, by stacking both adhesive surfaces of a single prepreg of this embodiment or a laminate of two or more prepregs (preferably 2 to 20 prepregs) of this embodiment and a metal foil together, and then vacuum pressing the laminate at a temperature of preferably 130 to 260°C, more preferably 180 to 250°C, and even more preferably 210 to 250°C, and at a pressure of 0.5 to 10 MPa, preferably 1 to 5 MPa.

[0045] Examples of metal foils used in metal-clad laminates include copper foil, aluminum foil, tin foil, tin-lead alloy (solder) foil, and nickel foil. Other examples include a three-layer composite foil in which an intermediate layer of nickel, nickel-phosphorus, nickel-tin alloy, nickel-iron alloy, lead, or lead-tin alloy is provided on both sides with a 0.5-15 μm copper layer and a 10-300 μm copper layer, and a two-layer composite foil in which aluminum and copper foil are combined. Copper foil and aluminum foil are preferred as metal foils, with copper foil being more preferred. The thickness of the metal foil can be a thickness typically used in laminates, for example, 1-200 μm.

[0046] In the laminate and metal-clad laminate of this embodiment, the prepreg (more specifically, the resin composition in the prepreg) is C-staged and cured. In other words, the laminate of this embodiment contains a C-staged prepreg, and the metal-clad laminate of this embodiment can also be said to contain a C-staged prepreg and a metal foil. Here, C-staging in this specification refers to achieving the C-stage state defined in JIS K6900 (1994).

[0047] [Printed Wiring Board] The printed wiring board of this embodiment includes the laminate or metal-clad laminate of this embodiment. The printed wiring board of this embodiment does not necessarily include the laminate or metal-clad laminate as is, and may include, for example, a laminate or metal-clad laminate that has been subjected to circuit formation processing such as drilling, metal plating, or metal foil etching. The printed wiring board of this embodiment can be manufactured by using the laminate or metal-clad laminate of this embodiment to perform circuit formation processing such as drilling, metal plating, or metal foil etching by a known method, and then further performing multi-layer processing as needed.

[0048] [Semiconductor Package] The semiconductor package of this embodiment includes the printed wiring board of this embodiment and a semiconductor element. In other words, the semiconductor package of this embodiment is formed by mounting a semiconductor element on the printed wiring board of this embodiment. The semiconductor package of this embodiment can be manufactured, for example, by mounting a semiconductor element such as a semiconductor chip or memory at a predetermined position on the printed wiring board of this embodiment by a known method and sealing the semiconductor element with a sealing resin or the like.

[0049] The present embodiment will be specifically described below with reference to examples, but the present embodiment is not limited to the following examples.

[0050] In each example, the weight average molecular weight (Mw) was measured by the following method. It was calculated from a calibration curve using standard polystyrene by gel permeation chromatography (GPC). The calibration curve was approximated by a cubic equation using standard polystyrene: TSKstandard POLYSTYRENE (Types: A-2500, A-5000, F-1, F-2, F-4, F-10, F-20, F-40) [manufactured by Tosoh Corporation]. The GPC measurement conditions are shown below. Apparatus: Pump: L-6200 type [manufactured by Hitachi High-Technologies Corporation] Detector: L-3300 type RI [manufactured by Hitachi High-Technologies Corporation] Column oven: L-655A-52 [manufactured by Hitachi High-Technologies Corporation] Column: Guard column; "TSK Guard column HHR-L" + column; "TSKgel G4000HHR" + "TSKgel G2000HHR" (all manufactured by Tosoh Corporation) Column size: 6.0 x 40 mm (guard column), 7.8 x 300 mm (column) Eluent: tetrahydrofuran Sample concentration: 30 mg / 5 mL Injection volume: 20 μL Flow rate: 1.00 mL / min Measurement temperature: 40°C

[0051] [Production Example 1: Production of Siloxane-Modified Maleimide Compound] 100 g of a siloxane modified at both ends with diamine (X-22-161A manufactured by Shin-Etsu Chemical Co., Ltd., amino functional group equivalent: 800 g / mol), 450 g of 2,2-bis[4-(4-maleimidophenoxy)phenyl]propane, and 550 g of propylene glycol monomethyl ether were placed in a 2 L reactor equipped with a thermometer, a stirrer, and a reflux condenser and a water content monitor, and the mixture was allowed to react at 120°C for 3 hours to produce a siloxane-modified maleimide compound-containing liquid. The weight-average molecular weight (Mw) of the resulting modified maleimide resin was 2,500.

[0052] Example 1 and Comparative Examples 1 to 3 (Preparation of Resin Composition and Resin Varnish) The components shown in Table 1 were blended in the amounts shown in Table 1 (the amounts listed in Table 1 are parts by mass of solids), and mixed in methyl ethyl ketone to obtain a resin composition (resin varnish) with a non-volatile content (solids concentration) of 50% by mass. (Preparation of Prepreg) The resin varnish prepared in each example was impregnated into glass cloth T2118 (manufactured by Nitto Boseki Co., Ltd.), and then heated and dried at 120°C for 5 minutes to obtain a prepreg. (Preparation of Double-Sided Copper-Clad Laminate) A 12 μm-thick electrolytic copper foil "3EC-M3-VLP-12" (manufactured by Mitsui Mining & Smelting Co., Ltd.) was placed on both sides of four stacked prepregs so that the adhesive surfaces faced the prepregs, and the mixture was heated and pressurized at 240°C for 80 minutes under vacuum pressure of 3 MPa to produce a double-sided copper-clad laminate. The obtained double-sided copper-clad laminate was evaluated according to the following evaluation methods. The results are shown in Table 1.

[0053] [Evaluation Method] (1) Flame Retardancy The double-sided copper-clad laminate obtained in each example was immersed in a 10% by mass solution of ammonium persulfate, a copper etching solution, to remove the copper foil, and then cut into five evaluation boards measuring 1.3 cm x 12.5 cm. A vertical combustion test (UL94 flammability test) was performed on the five evaluation boards obtained, and the combustion time was measured by exposure to flame for each board. The average combustion time for the five evaluation boards was calculated and used as an index of flame retardancy. It is preferable that the average combustion time be 10 seconds or less.

[0054] (2) Copper foil peel strength: The copper foil of each double-sided copper-clad laminate was partially etched to form a 3 mm wide copper foil line, which was used as a test piece. The load required to peel the copper foil line at a speed of 50 mm / min in a direction 90° to the adhesive surface was measured, and the resulting value was used as an index of copper foil peel strength. If the peel load was 0.6 kN / m or more, the copper foil peel strength was judged to be high, and an improvement of 0.1 kN / m was very useful industrially.

[0055] (3) Desmear Resistance The double-sided copper-clad laminate obtained in each example was immersed in a copper etching solution to prepare a 40 mm x 40 mm test piece from which the copper foil had been removed. This test piece was treated with a swelling treatment solution "Swelling Dip Securigant P" (manufactured by Atotech Japan Co., Ltd.) at 70°C for 5 minutes. Next, after rinsing with water at room temperature for 2 minutes, the test piece was roughened by treating with a roughening solution "Concentrate Compact CP" (manufactured by Atotech Japan Co., Ltd.) at 80°C for 10 minutes. After rinsing with water at 50°C for 2 minutes, the test piece was neutralized with a neutralizing solution "Reduction Solution Securigant P500" (manufactured by Atotech Japan Co., Ltd.) at 40°C for 5 minutes, rinsed with water at room temperature for 5 minutes, and then dried. The desmear weight loss was calculated from the difference between the dry weight before desmear treatment and the dry weight after desmear treatment (dry weight before desmear treatment - dry weight after desmear treatment), and the resulting value was used as an index of desmear resistance. A smaller desmear weight loss indicates higher desmear resistance.

[0056]

[0057] The details of the components in Table 1 are as follows: [Component (A)] Maleimide compound 1: siloxane-modified maleimide compound prepared in Production Example 1 Epoxy resin 1: "EPICLON (registered trademark) NC-3000H", biphenylaralkyl novolac epoxy resin (manufactured by Nippon Kayaku Co., Ltd.), epoxy equivalent: 280 to 300 g / eq

[0058] [Component (B)] Phosphorus-based flame retardant 1: a phosphorus-based flame retardant having a styrene skeleton and having the following structure, manufactured by Fushimi Pharmaceutical Co., Ltd. (n １ is an integer from 3 to 8.

[0059] Phosphorus-based flame retardant 2: "Ravitor FP-110", a phosphorus-based flame retardant having the following structure, manufactured by Fushimi Pharmaceutical Co., Ltd. (n ２ is an integer from 3 to 8.

[0060] Phosphorus-based flame retardant 3: "Ravitor FP-400", a phosphorus-based flame retardant having the following structure, manufactured by Fushimi Pharmaceutical Co., Ltd. (n ３ is an integer from 3 to 8.

[0061] Phosphorus-based flame retardant 4: Phosphorus-based flame retardant "HCA" having the following structure, manufactured by Sanko Co., Ltd.

[0062] [Component (C)] Filler 1: silane coupling-treated fused spherical silica, average particle size 0.5 μm

[0063] [Component (D)] Curing accelerator 1: Isocyanate masked imidazole "G-8009L" (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.)

[0064] As is clear from Table 1, the copper-clad laminates of the examples using the resin compositions of the present embodiment exhibited excellent flame retardancy, as well as high copper foil peel strength and high desmear resistance.

Claims

1. A resin composition containing (A) a thermosetting resin and (B) a flame retardant, wherein the (B) flame retardant comprises (B1) a phosphorus-based flame retardant having a styrene skeleton.

2. The resin composition according to claim 1, wherein the component (B1) has two or more styrene skeletons.

3. The resin composition according to claim 1, wherein the component (B1) has a structural unit represented by the following general formula (B-1): (In the formula, R ｂ１ represents an organic group having 1 to 20 carbon atoms.

4. The resin composition according to claim 1, wherein the content of the component (B1) is 1 to 25 parts by mass per 100 parts by mass of the total amount of the components (A) and (B).

5. The resin composition according to claim 1, wherein the component (A) comprises at least one selected from the group consisting of epoxy resins, polyimide resins, maleimide compounds, phenolic resins, polyphenylene ether resins, bismaleimide triazine resins, cyanate resins, isocyanate resins, benzoxazine resins, oxetane resins, amino resins, unsaturated polyester resins, allyl resins, dicyclopentadiene resins, and silicone resins.

6. The resin composition according to claim 1, wherein the component (A) comprises at least one member selected from the group consisting of maleimide compounds having one or more N-substituted maleimide groups and derivatives thereof.

7. The resin composition according to claim 1, wherein component (A) comprises a siloxane-modified maleimide compound.

8. The resin composition according to claim 1, further comprising (C) a filler.

9. A prepreg comprising a substrate and a semi-cured product of the resin composition according to claim 1.

10. A laminate comprising the prepreg of claim 9.

11. A metal-clad laminate comprising a metal foil and a cured product of the prepreg according to claim 9.

12. A printed wiring board comprising the laminate of claim 10 or the metal-clad laminate of claim 11.

13. A semiconductor package comprising the printed wiring board according to claim 12 and a semiconductor element.

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