JP7725895B2 - Thermosetting resin composition and its uses - Google Patents

Description

The present invention relates to a thermosetting resin composition and its use.

Norbornene-based resins have traditionally been characterized by their excellent electrical and optical properties, low moisture absorption, and other characteristics, and have been used in a variety of molded products.

Patent Document 1 discloses a resin composition containing a cyclic olefin homopolymer with a glass transition temperature of 101 to 160°C, a fibrous conductive filler, and another elastomer. It states that molding materials obtained from this resin composition have excellent mechanical strength, heat resistance, and conductivity.

Patent Document 2 discloses a method for producing a polycyclic olefin polymer by polymerizing a polycyclic olefin monomer in the presence of a palladium catalyst complex and a chain transfer/activation agent.

Patent Document 3 discloses a cyclic olefin binary copolymer containing specific molar amounts of repeating units derived from a norbornene monomer containing an epoxy group and repeating units derived from a norbornene monomer containing a vinyl group. The document states that the weight-average molecular weight of this cyclic olefin binary copolymer is 1,000 g/mol to 100,000 g/mol. It also states that a cured product obtained from a cyclic olefin binary copolymer containing these repeating units exhibits excellent adhesive strength with copper foil and improved dielectric loss at 10 GHz.

JP 2013-231171 A Special Publication No. 2010-523766 Special table 2019-506488 publication

However, the polymers described in Patent Documents 1 and 2 are not thermosetting, have low solubility in organic solvents, and furthermore, there is room for improvement in the low dielectric properties of the resulting cured products.
The cured product of the cyclic olefin-based binary copolymer described in Patent Document 3 has room for improvement in terms of low dielectric properties.

The present inventors have discovered that a thermosetting resin composition containing specific structural units constituting a cyclic olefin copolymer, which is a thermosetting resin, and further containing a crosslinking agent can give a cured product having low dielectric constant and dielectric dissipation factor and excellent dielectric properties, and have completed the present invention.
That is, the present invention can be shown as follows.

According to the present invention,
(A) a thermosetting resin;
(B) a crosslinking agent;
Including,
The thermosetting resin (A) is
A structural unit a represented by the following general formula (1),
A structural unit b represented by the following general formula (2),
and a weight average molecular weight of 500 or more and 10,000 or less.
(In general formula (1), R ¹ , R ² , R ³ and R ⁴ each independently represent a hydrogen atom or a substituted or unsubstituted hydrocarbon group having 1 to 30 carbon atoms (excluding groups having a terminal double bond); and n is 0, 1 or 2.)
(In general formula (2), Q represents a group having a terminal double bond, R ¹ , R ² , and R ³ each independently represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and m is 0, 1, or 2.)

According to the present invention,
A carrier substrate;
A resin film with a carrier is provided, the resin film being made of the thermosetting resin composition and provided on the carrier substrate.

According to the present invention,
A prepreg is provided which contains a fiber substrate in a resin layer made of the thermosetting resin composition.

According to the present invention,
A laminate is provided in which a metal layer is disposed on at least one surface of the prepreg.

According to the present invention,
There is provided a printed wiring board having an insulating layer made of a cured product of the thermosetting resin composition.

According to the present invention,
the printed wiring board;
and a semiconductor element mounted on a circuit layer of the printed wiring board or embedded in the printed wiring board.

The present invention provides a thermosetting resin composition that has excellent heat resistance and can produce a cured product with low dielectric constant and dielectric dissipation factor, resulting in excellent dielectric properties. In other words, it provides a thermosetting resin composition that has an excellent balance of these properties.

FIG. 2 is a cross-sectional view showing an example of the configuration of a resin film with a carrier in the present embodiment. 1 is a cross-sectional view showing an example of the configuration of a printed wiring board according to an embodiment of the present invention. 1 is a cross-sectional view showing an example of the configuration of a semiconductor device according to an embodiment of the present invention. 5A to 5C are cross-sectional views showing steps in an example of a manufacturing process for a printed wiring board according to the present embodiment. 1 is a cross-sectional view showing an example of the configuration of a printed wiring board according to an embodiment of the present invention. 1 is a cross-sectional view showing an example of the configuration of a printed wiring board according to an embodiment of the present invention.

Embodiments of the present invention will be described below with reference to the drawings. Note that in all drawings, similar components will be given similar reference numerals, and descriptions will be omitted where appropriate. Furthermore, "A-B" means "A or more" to "B or less" unless otherwise specified.

The thermosetting resin composition of this embodiment contains a thermosetting resin (A) and a crosslinking agent (B).

[Thermosetting resin (A)]
The thermosetting resin (A) of this embodiment contains a structural unit a represented by the following general formula (1) and a structural unit b represented by the following general formula (2), and has a weight average molecular weight of 500 or more and 10,000 or less.

In the general formula (1), n is 0, 1 or 2, preferably 0 or 1.
R ¹ , R ² , R ³ , and R ⁴ each independently represent a hydrogen atom or a substituted or unsubstituted hydrocarbon group having 1 to 30 carbon atoms. In this embodiment, the hydrocarbon group having 1 to 30 carbon atoms does not include a group having a terminal double bond. Plural R ¹ s, R ² s, R ³ s, and R ⁴ s present in the thermosetting resin (A) may be the same or different.

Examples of hydrocarbon groups having 1 to 30 carbon atoms include alkyl groups, alkenyl groups, alkynyl groups, alkylidene groups, aryl groups, aralkyl groups, alkaryl groups, and cycloalkyl groups.

Examples of alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, neopentyl, hexyl, heptyl, octyl, nonyl, and decyl groups.

Examples of the alkenyl group include an allyl group, a pentenyl group, etc. Examples of the alkynyl group include an ethynyl group.
The alkylidene group includes, for example, an ethylidene group.

Examples of aryl groups include phenyl, naphthyl, and anthracenyl groups. Examples of aralkyl groups include benzyl and phenethyl groups.

Examples of alkaryl groups include tolyl and xylyl. Examples of cycloalkyl groups include adamantyl, cyclopentyl, cyclohexyl, and cyclooctyl.

The hydrocarbon group having 1 to 30 carbon atoms may contain at least one atom selected from O, N, S, P, and Si in its structure.

In this embodiment, the hydrocarbon group having 1 to 30 carbon atoms is preferably a hydrocarbon group having 1 to 15 carbon atoms, and more preferably a hydrocarbon group having 1 to 10 carbon atoms. Furthermore, the hydrocarbon group having 1 to 30 carbon atoms is preferably an alkyl group having 1 to 30 carbon atoms, more preferably an alkyl group having 1 to 15 carbon atoms, and even more preferably an alkyl group having 1 to 10 carbon atoms.

Substituents on the substituted hydrocarbon group having 1 to 30 carbon atoms include hydroxyl groups, amino groups, cyano groups, ester groups, ether groups, amide groups, and sulfonamide groups, and the group may be substituted with at least one type of group.

In this embodiment, it is preferred that one of R ¹ , R ² , R ³ and R ⁴ is a substituted or unsubstituted hydrocarbon group having 1 to 30 carbon atoms, and the rest are hydrogen atoms, and it is more preferred that all are hydrogen atoms.
In this embodiment, the thermosetting resin (A) can contain at least one of the above structures as the structural unit a.

In the general formula (2), m is 0, 1 or 2, preferably 0 or 1.
Q represents a group having a terminal double bond.
The group having a terminal double bond can include a vinyl group, an allyl group, a (meth)acryloyl group, a vinylphenyl group, or a maleimide group.

Examples of groups having a terminal double bond include vinyl groups, allyl groups, (meth)acryloyl groups, vinylphenyl groups, (meth)acryloylalkyl groups, (meth)acryloyloxyalkyl groups, vinylphenylalkyl groups, and vinylphenyloxyalkyl groups, and these groups may contain ether bonds or thioether bonds in the alkylene chain.

R ¹ , R ² and R ³ each independently represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.
In this embodiment, it is preferred that one of R ¹ , R ² and R ³ is an alkyl group having 1 to 3 carbon atoms and the rest are hydrogen atoms, and it is more preferred that all are hydrogen atoms.

In this embodiment, the thermosetting resin (A) can contain at least one of the above structures as the structural unit b.
Specific examples of the structural unit b represented by general formula (2) include a structural unit derived from 5-vinyl-2-norbornene, a structural unit derived from butenylnorbornene, a structural unit derived from hexenylnorbornene, and a structural unit represented by the following formula, and one or more selected from these can be used.

In terms of the effects of the present invention, as well as thermosetting properties and solvent solubility, the thermosetting resin (A) of this embodiment can have a molar ratio of structural unit b to structural unit a (b/a) of 0.1 or more and 4 or less, preferably 0.1 or more and 3.5 or less, and more preferably 0.1 or more and 3 or less.

The thermosetting resin (A) of this embodiment contains structural units a and b, and may contain structural units derived from other monomers in addition to these structural units.

Other monomers include indene, styrene, acenaphthylene, norbornadiene, terpene compounds (e.g., pinene, limonene, etc.), linear alkenes (e.g., pentene, etc.), and cyclic alkenes (cyclohexene, etc.).

The thermosetting resin (A) of this embodiment does not contain structural units derived from ethylene or α-olefins, nor does it contain structural units derived from maleic acid, maleimide, maleic anhydride, etc., which affect the dielectric constant.

From the viewpoint of low dielectric constant, the thermosetting resin (A) has a total amount of structural units a and b of 80 mol % or more, preferably 90 mol %, and more preferably 95 mol % or more, based on 100 mol % of all structural units. The upper limit is not particularly limited, but is preferably 100 mol % or less.

The weight average molecular weight (Mw) of the thermosetting resin (A) is 500 or more and 10,000 or less, preferably 600 or more and 8,000 or less, and more preferably 700 or more and 7,000 or less, from the viewpoints of the effects of the present invention, thermosetting property, and solvent solubility.

The thermosetting resin (A) of this embodiment may have a weight-average molecular weight (Mw)/number-average molecular weight (Mn) ratio of, for example, 1.0 to 6.0, preferably 1.2 to 5.0, and more preferably 1.5 to 4.0. Note that Mw/Mn is the dispersity, which indicates the width of the molecular weight distribution.

The weight average molecular weight (Mw), number average molecular weight (Mn), and molecular weight distribution (Mw/Mn) are polystyrene-equivalent values obtained from a calibration curve of standard polystyrene (PS) obtained by, for example, GPC (Gel Permeation Chromatography) measurement. The measurement conditions are, for example, as follows:
Tosoh gel permeation chromatography device HLC-8320GPC
Column: TSK-GEL Supermultipore HZ-M manufactured by Tosoh Corporation
Detector: RI detector for liquid chromatography Measurement temperature: 40°C
Solvent: THF
Sample concentration: 0.5 wt%

The thermosetting resin (A) of this embodiment has a solubility in toluene at 25° C. of 30 wt % or more, preferably 50 wt % or more, and more preferably 60 wt % or more. The solubility is calculated by the following formula.
Formula: [Weight of thermosetting resin (A) / (Weight of thermosetting resin (A) + Weight of toluene)] × 100
Because of this high solubility in organic solvents, it has excellent film-forming properties and compatibility with other resins.

The thermosetting resin (A) of this embodiment has excellent melting properties (or excellent embeddability during substrate fabrication), and its melting temperature is, for example, 250°C or lower, preferably 230°C or lower, and more preferably 200°C or lower. The lower limit of the melting temperature is 50°C or higher, preferably 60°C or higher, and more preferably 70°C or higher. Because the thermosetting resin (A) of this embodiment is thermosetting and has the above melting temperature, it has excellent manufacturing stability for interlayer insulating films that constitute the multilayer wiring structure of semiconductor elements, build-up layers or core layers that constitute circuit boards, and the like, and can be suitably used for these semiconductor applications.

[Method for synthesizing thermosetting resin (A)]
The method for synthesizing the thermosetting resin (A) of this embodiment can be, for example,
The method includes a step of reacting a compound a1 represented by the following general formula (1a) with a compound b1 represented by the following general formula (2a) in an organic solvent in the presence of a polymerization catalyst and a chain transfer agent.

In formula (1a), R ¹ , R ² , R ³ , R ⁴ and n have the same meanings as in formula (1).

In formula (2a), Q, R ¹ , R ² , R ³ and m have the same meanings as in formula (1).
Specific examples of the compound b1 represented by general formula (2a) include 5-vinyl-2-norbornene, butenylnorbornene, hexenylnorbornene, and compounds represented by the following formulae (from the left, bicyclo[2.2.1]hept-5-en-2-yl methacrylate, 2-propenoic acid 2-methyl-bicyclo[2.2.1]hept-5-en-2-ylmethyl ester, 2-propenoic acid bicyclo[2.2.1]hept-5-en-2-ylmethyl ester, and 5-[[(4-ethenylphenyl)methoxy]methyl]bicyclo[2.2.1]hept-2-ene), and one or more selected from these can be used.

In this embodiment, first, the compound a1, the compound b1, and a chain transfer agent are dissolved in an organic solvent, and then the solution is preheated to about 40°C to 85°C.
The molar ratio (b1/a1) of the compound b1 represented by the following general formula (2a) to the compound a1 represented by the general formula (1a) can be set to 0.1 or more and 4 or less, preferably 0.1 or more and 3.5 or less, and more preferably 0.1 or more and 3 or less, from the viewpoint of thermosetting properties.

A catalyst dilution solution is prepared by diluting the polymerization catalyst and, if necessary, a cocatalyst in an organic solvent, and added to the heated mixed solution. The catalyst dilution solution may be added all at once or dropwise. Examples of dilution solvents include toluene, ethyl acetate, and tetrahydrofuran, and one or more of these can be used in combination.

The diluted catalyst solution is added to the mixed solution, and then heated for a predetermined period of time to carry out solution polymerization.
In this case, the heating temperature may be, for example, about 30° C. to 200° C., and the heating time may be, for example, 0.5 to 72 hours. It is more preferable to carry out the solution polymerization after removing dissolved oxygen in the solvent by nitrogen bubbling.
If necessary, a molecular weight modifier can be used.

Examples of the organic solvent include ketone solvents, ether solvents, ester solvents, acyclic aliphatic alcohol solvents, and aromatic solvents, and one or more selected from these can be used. Specific examples of these organic solvents include cyclopentanone, heptanone, anisole, butanol, and toluene, and one or more selected from these can be used.

By using these organic solvents, it is possible to obtain cyclic olefin resins that are thermosetting, have excellent solubility in organic solvents, and also have low dielectric properties.

Examples of chain transfer agents include trialkylsilane compounds such as trimethylsilane, triethylsilane, and tributylsilane, and cyclobutene compounds such as bicyclo[4.2.0]oct-7-ene. These chain transfer agents may be used alone or in combination of two or more.

By using these chain transfer agents, it is possible to obtain a cyclic olefin resin that is thermosetting, has excellent solubility in organic solvents, and also has excellent low dielectric properties.
In this embodiment, from the viewpoint of obtaining a desired cyclic olefin resin, it is more preferable to use the organic solvent and the chain transfer agent in combination.

There is no particular restriction on the polymerization catalyst as long as it allows addition polymerization to proceed. For example, palladium complexes and nickel complexes may be coordinated with phosphine, diimine, or nitrile ligands, and counter anions may be used. One or more of these may be used.

Examples of the palladium complex include palladium(II)(acetonitrile)bis(triisopropylphosphine)acetatetetrakis(2,3,4,5,6-pentafluorophenyl)borate,
allylpalladium complexes such as π-allylpalladium chloride dimer;
Palladium organic carboxylates such as palladium acetate, propionate, maleate, and naphthoate;
complexes of palladium with organic carboxylic acids such as a triphenylphosphine complex of palladium acetate, a tri(m-tolyl)phosphine complex of palladium acetate, a tricyclohexylphosphine complex of palladium acetate, and a triisopropylphosphine complex of palladium acetate;
palladium dibutyl phosphite, palladium p-toluenesulfonate and other organic sulfonates of palladium;
β-diketone compounds of palladium such as bis(acetylacetonato)palladium, bis(hexafluoroacetylacetonato)palladium, bis(ethylacetoacetate)palladium, and bis(phenylacetoacetate)palladium;

Examples include palladium halide complexes such as dichlorobis(triphenylphosphine)palladium, bis[tri(m-tolylphosphine)]palladium, dibromobis[tri(m-tolylphosphine)]palladium, and acetonyltriphenylphosphonium complexes.

Examples of the phosphine ligand include triphenylphosphine, dicyclohexylphenylphosphine, cyclohexyldiphenylphosphine, and tricyclohexylphosphine.

Examples of the counter anion include tetrakis(pentafluorophenyl)borate, triphenylcarbenium tetrakis(pentafluorophenyl)borate, triphenylcarbenium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate, triphenylcarbenium tetrakis(2,4,6-trifluorophenyl)borate, triphenylcarbenium tetraphenylborate, and tributylammonium tetrakis(pentafluorophenyl)borate.
The polymerization catalyst can be used in an amount of 1 ppmmol to 1000 ppmmol based on the norbornene-based monomers (compound a1 and compound b1).

The pre-cocatalyst preferably contains an ionic complex containing a weakly coordinating anion salt. In other words, when synthesizing the addition-type norbornene-based resin, it is preferable to add a co-catalyst in addition to the catalyst. This can further increase the polymerization rate of the addition-type norbornene-based monomer.

The co-catalyst is not particularly limited, but examples include alkylaluminum, Lewis acids, and ionic complexes containing weakly coordinating anion (WCA) salts, and among these, ionic complexes containing weakly coordinating anion (WCA) salts are preferred.

Furthermore, the promoter is more preferably one represented by the following formula (i):
[C] _e [WCA] _d formula (i)
(In the above formula, C represents a proton (H ⁺ ), an organic radical-containing cation, or an alkali metal, alkaline earth metal, or transition metal cation; WCA is as defined above; and e and d are numbers determined to balance the electronic charge on the overall salt complex of the cation complex (C) and the weakly coordinating anion salt (WCA), respectively.)

Examples of ionic complexes containing the weakly coordinating anion (WCA) salt include, but are not limited to, lithium(diethyl ether) _2.5 tetrakis(pentafluorophenyl)borate, dimethylanilinium tetrakis(pentafluorophenyl)borate, dimethylanilinium tetrakis(3,5-bis(trifluoromethyl)phenyl)borate, H(OEt2) _x tetrakis(pentafluorophenyl)borate, tetrakis[( ₄ -methyl)-α,α-bis(trifluoromethyl)benzenemethanolato-κO]aluminate, sodium tetrakis(3,5-bis(trifluoromethyl)phenyl)borate, trialkyl and triarylphosphonium tetrakis(pentafluorophenyl)borate, and trityl tetrakis(pentafluorophenyl)borate.
The co-catalyst can be used in an amount of 1 ppmmol to 1000 ppmmol relative to the norbornene-based monomers (compound a1 and compound b1).

The resulting reaction liquid containing the thermosetting resin (A) is added to an alcohol such as hexane or methanol to precipitate the thermosetting resin (A). The thermosetting resin (A) is then filtered, washed with an alcohol such as hexane or methanol, and then dried.
In this embodiment, for example, the thermosetting resin (A) can be synthesized in this manner.

[Resin varnish]
In this embodiment, a polymer solution (resin varnish) in which the thermosetting resin (A) is dissolved in an organic solvent can be provided. In this polymer solution (resin varnish), at a liquid temperature of 25° C., it is sufficient that at least a portion of the polymer is dissolved, but it is preferable that all of the polymer is dissolved.

Organic solvents used in resin varnishes include acetone, ethyl acetate, cyclohexane, heptane, tetrahydrofuran, dimethylformamide, dimethylacetamide, dimethyl sulfoxide, ethylene glycol, cellosolve-based solvents, carbitol-based solvents, anisole, N-methylpyrrolidone, propylene glycol monomethyl ether, methyl ether acetate, toluene, cyclohexanone, methyl ethyl ketone, and methyl isobutyl ketone. Organic solvents selected from these can be used alone or in combination of two or more.

The lower limit of the thermosetting resin content in the resin varnish is, for example, 5% by mass or more, preferably 7% by mass or more, more preferably 10% by mass or more, and even more preferably 15% by mass or more, based on 100% by mass of the resin varnish. On the other hand, the upper limit of the thermosetting resin content in the resin varnish is, for example, 80% by mass or less, preferably 70% by mass or less, more preferably 65% by mass or less, and even more preferably 60% by mass or less, based on 100% by mass of the resin varnish. By keeping the content within this numerical range, the handleability of the resin varnish can be improved, and a resin material with excellent heat resistance can be achieved.

[Thermosetting resin composition]
The thermosetting resin composition of the present embodiment can be prepared using a resin varnish, and contains the above-described thermosetting resin (A) and a crosslinking agent (B). The curable resin composition of the present embodiment can provide a low dielectric constant material.

[Crosslinking agent (B)]
The crosslinking agent (B) can crosslink the thermosetting resin (A), and any known crosslinking agent can be used as long as the effects of the present invention are achieved. However, it is preferable that the crosslinking agent (B) contains a crosslinking agent (b1) that is liquid at room temperature (25°C).
The thermosetting resin composition of the present embodiment contains the crosslinking agent (b1), and thus can give a cured product having excellent heat resistance and low dielectric properties.

The crosslinking agent (b1), which is liquid at room temperature (25°C), may contain a crosslinking agent having two or more reactive groups. Examples of reactive groups include vinyl groups, allyl groups, (meth)acryloyl groups, vinylphenyl groups, and maleimide groups.

Examples of the crosslinking agent having two or more reactive groups include styrene-butadiene rubber, polybutadiene rubber, triallyl isocyanurate, and divinylbenzene, and at least one selected from these can be used.
The crosslinking agent (b1) can be contained in an amount of 5 parts by mass or more and 200 parts by mass or less, preferably 10 parts by mass or more and 180 parts by mass or less, and more preferably 20 parts by mass or more and 150 parts by mass or less, relative to 100 parts by mass of the thermosetting resin (A).

The crosslinking agent (B) preferably contains crosslinking agent (b2) that is solid at room temperature (25°C) in addition to crosslinking agent (b1). By further including crosslinking agent (b2), a cured product with superior heat resistance and low dielectric properties can be obtained.

The crosslinking agent (b2), which is solid at room temperature (25°C), can contain a crosslinking agent having a weight-average molecular weight of 1,000 or more and 20,000 or less, preferably 1,000 or more and 10,000 or less, and more preferably 1,000 or more and 7,000 or less. If the weight-average molecular weight of the crosslinking agent falls within this range, the crosslinking agent will have excellent solvent solubility and compatibility, and will have excellent processability due to a reduced viscosity of the varnish.

Examples of the crosslinking agent (b2) include methacrylate-terminated polyphenylene ether, styrene-modified polyphenylene ether, bisphenol A dimethacrylate, and bis(3-ethyl-5-methyl-4-maleimidophenyl)methane, and at least one selected from these can be used.

When the crosslinking agent (B) contains the crosslinking agent (b2), the crosslinking agent (b2) can be contained in an amount of 10 parts by mass or more and 200 parts by mass or less, preferably 20 parts by mass or more and 180 parts by mass or less, and more preferably 30 parts by mass or more and 150 parts by mass or less, relative to 100 parts by mass of the thermosetting resin (A).
Furthermore, the weight ratio (b1:b2) of the crosslinking agent (b1) to the crosslinking agent (b2) can be set to 5:95 to 95:5, preferably 20:80 to 80:20, and more preferably 25:75 to 75:25.

[Radical polymerization initiator (C)]
The thermosetting resin composition of the present embodiment preferably further contains a radical polymerization initiator (C).

Radical polymerization initiators (C) include methyl ethyl ketone peroxide, methylcyclohexanone peroxide, methyl acetoacetate peroxide, acetylacetone peroxide, 1,1-bis(t-butylperoxy)3,3,5-trimethylcyclohexane, 1,1-bis(t-hexylperoxy)cyclohexane, 1,1-bis(t-hexylperoxy)3,3,5-trimethylcyclohexane, 1,1-bis(t-butylperoxy)cyclohexane, 2,2-bis(4,4-di-t-butylperoxycyclohexyl)propane, 1,1-bis(t-butylperoxy)cyclododecane, n-butyl 4,4-bis(t-butylperoxy)valerate, 2,2-bis(t-butylperoxy)butane, 1,1-bis(t-butylperoxy)-2-methylcyclohexane, t-butyl hydroperoxide, p-menthane hydroperoxide, 1, 1,3,3-tetramethylbutyl hydroperoxide, t-hexyl hydroperoxide, dicumyl peroxide, 2,5-dimethyl-2,5-bis(t-butylperoxy)hexane, α,α'-bis(t-butylperoxy)diisopropylbenzene, t-butylcumyl peroxide, di-t-butyl peroxide, 2,5-dimethyl-2,5-bis(t-butylperoxy)-3-hexyne, isobutyryl peroxide, 3,5,5-trimethylhexanoyl peroxide, octanoyl peroxide, lauroyl peroxide, cinnamic acid peroxide, m-toluoyl peroxide, benzoyl peroxide, diisopropyl peroxydicarbonate, bis(4-t-butylcyclohexyl)peroxydicarbonate, di-3-methoxybutyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, di-sec-butyl Peroxydicarbonate, di(3-methyl-3-methoxybutyl)peroxydicarbonate, di(4-t-butylcyclohexyl)peroxydicarbonate, α,α'-bis(neodecanoylperoxy)diisopropylbenzene, cumylperoxyneodecanoate, 1,1,3,3-tetramethylbutylperoxyneodecanoate, 1-cyclohexyl-1-methylethylperoxyneodecanoate, t-hexylperoxy Neodecanoate, t-butylperoxyneodecanoate, t-hexylperoxypivalate, t-butylperoxypivalate, 2,5-dimethyl-2,5-bis(2-ethylhexanoylperoxy)hexane, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, 1-cyclohexyl-1-methylethylperoxy-2-ethylhexanoate, t-hexylperoxy-2-ethylhexanoate, t- Examples include butylperoxy-2-ethylhexanoate, t-butylperoxyisobutyrate, t-butylperoxymaleic acid, t-butylperoxylaurate, t-butylperoxy-3,5,5-trimethylhexanoate, t-butylperoxyisopropyl monocarbonate, t-butylperoxy-2-ethylhexyl monocarbonate, 2,5-dimethyl-2,5-bis(benzoylperoxy)hexane, t-butylperoxyacetate, t-hexylperoxybenzoate, t-butylperoxy-m-toluoylbenzoate, t-butylperoxybenzoate, bis(t-butylperoxy)isophthalate, t-butylperoxyallyl monocarbonate, and 3,3',4,4'-tetra(t-butylperoxycarbonyl)benzophenone. These can be used alone or in combination to control curing properties.

The radical polymerization initiator (C) can be used in an amount of 0.1 to 5 parts by mass per 100 parts by mass of the thermosetting resin (A) and crosslinking agent (B) combined.

[Filler (D)]
The thermosetting resin composition of the present embodiment preferably further contains a filler (D).
Examples of the filler (D) include silver, titanium oxide, silica, and mica. Among these, silica is preferred. This allows the cured product of the thermosetting resin composition to have excellent thermal properties.
The shape of the silica filler may be crushed silica or spherical silica, with spherical silica being preferred.

The content of filler (D) is not particularly limited, but is preferably 15 to 70 mass% and more preferably 20 to 70 mass% based on the total weight of the thermosetting resin composition. This provides the cured product of the thermosetting resin composition with excellent thermal properties.

(Other ingredients)
The thermosetting resin composition of the present embodiment may contain other components such as a resin other than a thermosetting resin, an acid generator, a heat resistance improver, a developing aid, a plasticizer, a polymerization inhibitor, an ultraviolet absorber, an antioxidant, a matting agent, an antifoaming agent, a leveling agent, an antistatic agent, a dispersant, a slip agent, a surface modifier, a thixotropic agent, a thixotropic aid, a surfactant, a silane-based, aluminum-based, or titanium-based coupling agent, a polyhydric phenol compound, or an organic solvent, depending on the purpose and required characteristics of each application.

<Thermosetting resin composition and cured product thereof>
The thermosetting resin composition of the present embodiment can be prepared by mixing the above-mentioned components using the resin varnish described above. The thermosetting resin composition of the present embodiment can provide a low dielectric constant material.

The thermosetting resin composition of this embodiment contains a polymer obtained by polymerizing a specified norbornene-based monomer. It is thermosetting, has excellent handleability, and can provide a low-dielectric-constant material. Therefore, it has excellent manufacturing stability for interlayer insulating films that make up the multilayer wiring structure of semiconductor elements, build-up layers or core layers that make up circuit boards, and the like, and is suitable for use in these semiconductor applications.

The curable resin composition of this embodiment can be thermally cured to obtain a cured product, after removing the organic solvent by drying or other methods as needed. Thermal curing can be carried out in air, a nitrogen atmosphere, a vacuum, or the like. If transparency is required for the resulting cured product, it is preferable to carry out the thermal curing in a nitrogen atmosphere or a vacuum, or to use an antioxidant in combination.

The glass transition temperature of the cured product (molded product) of this embodiment is preferably 120°C or higher, and more preferably 140°C or higher. A glass transition temperature of 120°C or higher satisfies the heat resistance required during molding processing. The upper limit of the glass transition temperature is not particularly limited, but is preferably 300°C or lower.

The relative dielectric constant at a frequency of 10 GHz of the cured product (molded product) of this embodiment can be 2.8 or less, preferably 2.6 or less, and more preferably 2.5 or less, when the cured product does not contain filler or glass cloth; and can be 4.0 or less, preferably 3.8 or less, and more preferably 3.5 or less, when the cured product contains filler or glass cloth. This allows the cured product to be used as a low-dielectric-constant material.

The cured product (molded product) of this embodiment has a dielectric loss tangent (tanδ) of 0.007 or less, preferably 0.006 or less, and more preferably 0.005 or less, when measured at a frequency of 10 GHz. This further improves the dielectric properties of the cured product.

[Application]
The thermosetting resin composition of the present embodiment may be used in any form, including, but not limited to, a resin film made of the thermosetting resin composition, a resin film with a carrier in which the resin film is provided on a carrier substrate, a prepreg obtained by impregnating a fiber substrate with the thermosetting resin composition, a metal-clad laminate in which a metal layer is disposed on at least one surface of the cured product of the prepreg, a resin substrate provided with an insulating layer made of a cured product of the thermosetting resin composition, and a printed wiring board in which a circuit layer is formed on the surface of the metal-clad laminate or the resin substrate.

(resin film with carrier)
Next, the resin film with a carrier of this embodiment will be described.
FIG. 1 is a cross-sectional view showing an example of the configuration of a resin film 100 with a carrier according to this embodiment.

1, the carrier-attached resin film 100 of this embodiment can include a carrier substrate 12 and a resin film 10 made of the thermosetting resin composition provided on the carrier substrate 12. This can improve the handleability of the resin film 10.
The resin film with a carrier 100 may be in a roll shape that can be wound up, or in a sheet shape such as a rectangular shape.

In this embodiment, the carrier substrate 12 may be, for example, a polymer film or a metal foil. Examples of the polymer film include, but are not limited to, polyolefins such as polyethylene and polypropylene; polyesters such as polyethylene terephthalate and polybutylene terephthalate; polycarbonate; release paper such as silicone sheets; and heat-resistant thermoplastic resin sheets such as fluorine-based resins and polyimide resins. Examples of the metal foil include, but are not limited to, copper and/or copper-based alloys.

Examples include gold, aluminum and/or aluminum-based alloys, iron and/or iron-based alloys, silver and/or silver-based alloys, gold and gold-based alloys, zinc and zinc-based alloys, nickel and nickel-based alloys, and tin and tin-based alloys. Of these, a sheet made of polyethylene terephthalate is most preferred because it is inexpensive and the peel strength can be easily adjusted. This makes it easy to peel from the carrier-attached resin film 100 with an appropriate strength.

The lower limit of the thickness of the resin film 10 is not particularly limited, but may be, for example, 1 μm or more, 3 μm or more, or 5 μm or more. This increases the mechanical strength of the resin film 10. On the other hand, the upper limit of the thickness of the resin film 10 is not particularly limited, but may be, for example, 500 μm or less, 300 μm or less, or 100 μm or less. This allows for the semiconductor device to be made thinner.

The thickness of the carrier substrate 12 is not particularly limited, but may be, for example, 10 to 100 μm, or 10 to 70 μm. This is preferable because it allows for good handling when producing the carrier-attached resin film 100.

The carrier-attached resin film 100 of this embodiment may be single-layered or multi-layered, and may contain one or more types of resin film 10. When the resin sheet is multi-layered, it may be composed of the same type or different types. In addition, the carrier-attached resin film 100 may have a protective film on the outermost layer side of the resin film 10.

In this embodiment, the method for forming the carrier-attached resin film 100 is not particularly limited. For example, a method can be used in which a varnish-like thermosetting resin composition is applied to the carrier substrate 12 using various coater devices to form a coating film, and then the coating film is appropriately dried to remove the solvent.

(Resin substrate)
The resin substrate of the present embodiment can have an insulating layer made of a cured product of a thermosetting resin composition. Such a resin substrate can be configured to contain no glass fibers and can be used as a printed wiring board.

(prepreg)
The prepreg of this embodiment is obtained by impregnating a fiber substrate with the thermosetting resin composition. For example, the prepreg can be used as a sheet-like material obtained by impregnating a fiber substrate with the thermosetting resin composition and then semi-curing the material. A sheet-like material having such a structure has excellent properties such as dielectric properties and mechanical and electrical connection reliability under high temperature and humidity conditions, and is suitable for producing insulating layers for printed wiring boards.

The method for impregnating a fiber substrate with a thermosetting resin composition is not particularly limited, but examples include dissolving the thermosetting resin composition in a solvent to prepare a resin varnish and then immersing the fiber substrate in the resin varnish, applying the resin varnish to the fiber substrate using various coaters, spraying the resin varnish onto the fiber substrate, and laminating both sides of the fiber substrate with the resin film made of the thermosetting resin composition.

In this embodiment, the prepreg can be used, for example, to form an insulating layer in a build-up layer or an insulating layer in a core layer of a printed wiring board. When using the prepreg to form an insulating layer in a core layer of a printed wiring board, for example, two or more prepregs can be stacked and the resulting laminate can be heat-cured to form an insulating layer for the core layer.

The fiber substrate may include, but is not limited to, glass fiber substrates such as glass woven fabric and glass nonwoven fabric; polyamide resin fibers such as polyamide resin fibers, aromatic polyamide resin fibers, and wholly aromatic polyamide resin fibers; polyester resin fibers such as polyester resin fibers, aromatic polyester resin fibers, and wholly aromatic polyester resin fibers; synthetic fiber substrates composed of woven or nonwoven fabrics primarily composed of polyimide resin fibers or fluororesin fibers; and paper substrates primarily composed of kraft paper, cotton linter paper, or a mixed paper of linter and kraft pulp. Any of these can be used. Of these, glass fiber substrates are preferred. This allows for the production of a resin substrate with low water absorption, high strength, and low thermal expansion.

The thickness of the fiber base material is not particularly limited, but is preferably 5 μm or more and 150 μm or less, more preferably 10 μm or more and 100 μm or less, and even more preferably 12 μm or more and 90 μm or less. Using a fiber base material with such a thickness can further improve handleability during prepreg production.

When the thickness of the fiber substrate is equal to or less than the upper limit, the impregnation of the thermosetting resin composition into the fiber substrate is improved, preventing strand voids and reduced insulation reliability. It also facilitates the formation of through-holes using carbon dioxide, UV, excimer, or other lasers. Furthermore, when the thickness of the fiber substrate is equal to or greater than the lower limit, the strength of the fiber substrate and prepreg can be improved. As a result, handling is improved, prepreg production is easier, and warping of the resin substrate can be prevented.

As the glass fiber substrate, for example, a glass fiber substrate formed from one or more types of glass selected from E glass, S glass, D glass, T glass, NE glass, UT glass, L glass, HP glass, and quartz glass is preferably used.

(Metal-clad laminate)
In this embodiment, the metal-clad laminate is one in which a metal layer is disposed on at least one surface of the cured product of the prepreg.
A method for manufacturing a metal-clad laminate using a prepreg is, for example, as follows.

Metal foil is placed on both or one of the outer surfaces of a prepreg or a laminate of two or more overlapping prepregs, and these are bonded under high vacuum conditions using a laminator or Becquerel apparatus, or metal foil is placed directly on both or one of the outer surfaces of the prepreg. When two or more prepregs are laminated, metal foil is placed on both or one of the outer surfaces of the laminated prepreg. Next, the laminate of overlapping prepregs and metal foil is heated and press-molded to obtain a metal-clad laminate. It is preferable to continue pressure during heating and press-molding until cooling is complete.

Examples of metals constituting the metal foil include copper, copper-based alloys, aluminum, aluminum-based alloys, silver, silver-based alloys, gold, gold-based alloys, zinc, zinc-based alloys, nickel, nickel-based alloys, tin, tin-based alloys, iron, iron-based alloys, Fe-Ni-based alloys such as Kovar (trade name), 42 Alloy, Invar, and Super Invar, W, and Mo. Among these, copper or copper alloys are preferred as the metal constituting the metal foil 105 because they have excellent conductivity, are easy to form circuits by etching, and are inexpensive. That is, copper foil is preferred as the metal foil 105.
As the metal foil, a metal foil with a carrier or the like can also be used.
The thickness of the metal foil is preferably 0.5 μm or more and 20 μm or less, and more preferably 1.5 μm or more and 18 μm or less.
According to this embodiment, by employing such a resin film or a prepreg using the same, it is possible to form an insulating layer in a printed wiring board having a reduced linear expansion coefficient in the planar direction.

(Printed wiring board)
The printed wiring board of this embodiment includes an insulating layer made of the cured resin film (cured thermosetting resin composition).

In this embodiment, the cured resin film can be used, for example, as a core layer, build-up layer, or solder resist layer of a normal printed wiring board, a build-up layer or solder resist layer of a printed wiring board that does not have a core layer, an interlayer insulating layer or solder resist layer of a coreless substrate used in PLP, an interlayer insulating layer or solder resist layer of an MIS substrate, etc. Such an insulating layer can also be suitably used as an interlayer insulating layer or solder resist layer constituting a large-area printed wiring board used to collectively produce multiple semiconductor packages.
Next, an example of the printed wiring board 300 of this embodiment will be described with reference to FIGS.

The printed wiring board 300 of this embodiment includes an insulating layer formed from the cured resin film 10 described above. As shown in FIG. 2(a), the printed wiring board 300 may have a structure including an insulating layer 301 (core layer) and an insulating layer 401 (solder resist layer). Alternatively, as shown in FIG. 2(b), the printed wiring board 300 may have a structure including an insulating layer 301 (core layer), an insulating layer 305 (build-up layer), and an insulating layer 401 (solder resist layer). Each of these core layer, build-up layer, and solder resist layer may be formed from, for example, a cured resin film of this embodiment. The core layer may be formed from a cured product obtained by curing a prepreg formed by impregnating a fiber substrate with the thermosetting resin composition of this embodiment.

The cured resin film of this embodiment can be free of fiber substrates such as glass cloth or paper substrates. This makes it particularly suitable for forming build-up layers (interlayer insulating layers) and solder resist layers.

Furthermore, the printed wiring board 300 according to this embodiment may be a single-sided printed wiring board, a double-sided printed wiring board, or a multilayer printed wiring board. A double-sided printed wiring board is a printed wiring board in which metal layers 303 are laminated on both sides of an insulating layer 301. A multilayer printed wiring board is a printed wiring board in which two or more build-up layers (e.g., insulating layer 305) are laminated on the insulating layer 301, which is the core layer, by a plated-through-hole method, a build-up method, or the like.

In this embodiment, the via holes 307 may be either through holes or blind holes, as long as they are holes for electrically connecting layers. The via holes 307 may be formed by embedding metal. This embedded metal may have a structure covered with an electroless metal plating film 308.

In addition, in this embodiment, the metal layer 303 may be, for example, a circuit pattern or an electrode pad. This metal layer 303 may have, for example, a metal laminate structure of a metal foil 105 and an electrolytic metal plating layer 309.

The metal layer 303 is formed by a semi-additive process (SAP) method on the surface of the chemically or plasma-treated metal foil 105 or an insulating layer (e.g., insulating layer 301 or insulating layer 305) made of a cured product of the resin film of this embodiment. For example, after applying an electroless metal plating film 308 to the metal foil 105 or the insulating layers 301 and 305, non-circuit formation areas are protected with a plating resist, and an electrolytic metal plating layer 309 is formed by electrolytic plating, followed by removing the plating resist and patterning the electrolytic metal plating layer 309 by flash etching, thereby forming the metal layer 303.
Furthermore, the printed wiring board 300 of this embodiment may be a resin board that does not contain glass fibers. For example, the insulating layer 301, which is the core layer, may be configured not to contain glass fibers.

(Semiconductor device)
3A and 3B are cross-sectional views showing an example of the configuration of a semiconductor device 400.

The semiconductor device 400 of this embodiment can include a printed wiring board 300 and a semiconductor element mounted on a circuit layer of the printed wiring board 300 or embedded in the printed wiring board 300.

For example, the semiconductor device 400 shown in FIG. 3(a) has a structure in which a semiconductor element 407 is mounted on the circuit layer (metal layer 303) of the printed wiring board 300 shown in FIG. 3(a). On the other hand, the semiconductor device 400 shown in FIG. 3(b) has a structure in which a semiconductor element 407 is mounted on the circuit layer (metal layer 303) of the printed wiring board 300 shown in FIG. 3(b). The semiconductor element 407 is covered with an encapsulant layer 413. Such a semiconductor package may have a flip-chip structure in which the semiconductor element 407 is electrically connected to the printed wiring board 300 via solder bumps 410 and the metal layer 303.

In this embodiment, the structure of the semiconductor package is not limited to the flip-chip connection structure described above, and various other structures may be used, such as a fan-out structure. The insulating layer made of the cured resin film of this embodiment can suppress substrate warping and cracking during the manufacturing process of a semiconductor package with a fan-out structure.

Next, a modified example of the printed wiring board of this embodiment will be described. Figure 4 is a cross-sectional view showing an example of a manufacturing process for the printed wiring board 500. Figure 4(c) shows a printed wiring board 500 that does not have a core layer.

The printed wiring board 500 of this embodiment does not include a core layer having a fiber substrate, and may be, for example, a coreless resin board configured with buildup layers and solder resist layers. These buildup layers and solder resist layers are preferably configured with insulating layers made of the cured resin film of this embodiment. For example, the printed wiring board 500 shown in FIG. 4( c) includes two buildup layers (insulating layers 540 and 550) and a solder resist layer (insulating layer 560). The buildup layer of the printed wiring board 500 may be a single layer, or may include two or more layers.
The insulating layer made of the cured resin film of this embodiment has excellent toughness, and therefore, warping of the printed wiring board 500 and cracks during transportation can be suppressed.

The metal layers 542, 552, and 562 shown in FIG. 4(c) may be circuit patterns or electrode pads, and may be formed by the SAP method, as described above. These metal layers 542, 552, and 562 may be a single layer or multiple metal layers.

The printed wiring board 500 may have a large surface area that allows multiple semiconductor elements to be mounted on the flat surface. This allows multiple semiconductor elements mounted on the printed wiring board 500 to be encapsulated together and then separated into individual pieces to obtain multiple semiconductor packages. The printed wiring board 500 may be a panel substrate having a substantially circular or rectangular shape, etc.

The manufacturing method of the printed wiring board 500 is not particularly limited, but can be, for example, obtained by forming a build-up layer and a solder resist layer on a support substrate 510 and then peeling off the support substrate 510. Specifically, as shown in FIG. 4( a), a carrier foil 520 and a metal foil 530 (e.g., copper foil) are placed on a large-area support substrate 510 (e.g., a plate member made of SUS). At this time, an adhesive resin (not shown) can be placed between the support substrate 510 and the carrier foil 520. Next, a metal layer 542 is formed on the metal foil 530. This metal layer 542 is patterned by a conventional method such as the SAP method. Next, the carrier film-attached resin film is laminated by a heat and pressure molding method or the like, and the carrier substrate is peeled off from the carrier film-attached resin film. The resin film is then cured. This process is repeated three times to form two build-up layers and one solder resist layer.
4B, the support substrate 510 is peeled off, and the metal foil 530 is removed by etching or the like.

As a result of the above, the printed wiring board 500 shown in FIG. 4(c) is obtained.
Next, a modified example of the printed wiring board of this embodiment will be described. Fig. 5 is a cross-sectional view showing an example of the configuration of a printed wiring board 600.

The printed wiring board 600 shown in Figure 5 may be composed of a coreless resin substrate 610 used in the PLP (panel level packaging) process. The PLP process, for example, utilizes a wiring board process to obtain a panel-sized package with an area larger than that of a wafer. By using the PLP process, it is possible to efficiently improve the productivity of semiconductor packages compared to wafer-level processes.

In this embodiment, the insulating layer 612 (interlayer insulating layer) and insulating layers 630, 632 (solder resist layers) of the coreless resin substrate 610 may be composed of insulating layers made of the cured resin film of this embodiment. The cured resin film of this embodiment has excellent toughness, so warping of the printed wiring board 600 during the PLP process and cracking of the coreless resin substrate 610, particularly during transportation and mounting, can be effectively suppressed.

Furthermore, the printed wiring board 600 of this embodiment has a large area that allows multiple semiconductor elements (not shown) to be mounted within its plane. Then, multiple semiconductor elements mounted in the in-plane direction of the printed wiring board 600 are encapsulated together, and then singulated to obtain multiple semiconductor packages. Because the linear expansion coefficient of the cured resin film of this embodiment can be reduced, package warpage can be suppressed in semiconductor packages obtained by the PLP process.

The printed wiring board 600 may include a coreless resin substrate 610 and a solder resist layer (insulating layers 630, 632) formed on its surface. The coreless resin substrate 610 may include an embedded semiconductor element 620. The semiconductor element 620 may be electrically connected via via wiring 616. The coreless resin substrate 610 may also include at least an insulating layer 612 (interlayer insulating layer) and via wiring 616. The via wiring 616 may electrically connect a metal layer 640 (electrode pad) on the lower surface to a metal layer 618 (post) on the upper surface. The via wiring 616 may also be connected to the metal layer 640 via a metal layer 614 (post). The via wiring 616 and the metal layer 614 are embedded in the coreless resin substrate 610. The surface of the metal layer 614, which serves as a post, may be flush with the surface of the coreless resin substrate 610. In the printed wiring board 600 of this embodiment, the coreless resin substrate 610 is composed of a single interlayer insulating layer, but is not limited to this configuration and may have a structure in which multiple interlayer insulating layers are stacked. At least via wiring 616 may be formed in such an interlayer insulating layer as interlayer connection wiring. Furthermore, in this embodiment, the via wiring 616, metal layer 614, or metal layer 618 may be composed of a metal such as copper.

The upper and lower surfaces of the coreless resin substrate 610 may also be covered with solder resist layers (insulating layers 630, 632). For example, the insulating layer 630 may cover a metal layer 650 formed on the surface of the insulating layer 612. The metal layer 650 is composed of a first metal layer 652 (plated layer) and a second metal layer 654 (electroless plated layer), and may be formed, for example, by the SAP method. The metal layer 650 may also be, for example, a circuit pattern or an electrode pad.

Furthermore, the method for manufacturing the printed wiring board 600 of this embodiment is not particularly limited, but the following method can be used, for example. For example, an insulating layer 612 is formed on a support substrate. Next, vias are formed in the insulating layer 612, and a metal film is embedded in the vias by a plating method to form via wiring 616. Next, rewiring (metal layer 650) is formed on the surface of the insulating layer 612 by a SAP method. Thereafter, multiple interlayer insulating layers having such interlayer connection wiring may be stacked. Then, solder resist layers (insulating layers 630, 632) are formed.
In this way, the printed wiring board 600 can be obtained.

Next, a modified example of the printed wiring board of this embodiment will be described. Figure 6 is a cross-sectional view showing an example of the configuration of the printed wiring board 700.

The printed wiring board 700 shown in Figure 6 can be composed of a substrate with posts (MIS substrate). For example, the substrate with posts can be composed of a coreless resin substrate 710 having a structure in which via wiring 716 and a metal layer 718 (posts) are embedded in an insulating layer 712 (interlayer insulating layer). The substrate with posts can be a substrate after being singulated, or a substrate with a large area (for example, a support such as a wafer) before being singulated.

By using the printed wiring board 700 of this embodiment, it is possible to efficiently improve the productivity of semiconductor packages to the same extent as or even better than wafer-level processes.

In this embodiment, the insulating layer 712 (interlayer insulating layer) and insulating layers 730, 732 (solder resist layers) of the coreless resin substrate 710 may be composed of insulating layers made of the cured resin film of this embodiment. The cured resin film of this embodiment has excellent toughness, which effectively prevents warping of the printed wiring board 700 and cracks in the coreless resin substrate 710, particularly during transportation and mounting.

The printed wiring board 700 of this embodiment also has a large surface area that allows multiple semiconductor elements (not shown) to be mounted within its plane. The multiple semiconductor elements mounted in the in-plane direction of the printed wiring board 700 are then encapsulated together, and then separated into individual pieces to obtain multiple semiconductor packages. Because the cured resin film of this embodiment can have a low linear expansion coefficient, package warpage can be suppressed in the resulting semiconductor package.

The printed wiring board 700 may include a coreless resin substrate 710 and a solder resist layer (insulating layers 730, 732) formed on its surface. The coreless resin substrate 710 may include an embedded semiconductor element 720. The semiconductor element 720 may be electrically connected via via wiring 716. The coreless resin substrate 710 may also include at least an insulating layer 712 (interlayer insulating layer), via wiring 716, and a metal layer 718 (post). The lower metal layer 714 (post) and the upper metal layer 718 (post) may be electrically connected via the via wiring 716. The metal layer 714 embedded in the insulating layer 712 may be connected to a metal layer 740 (electrode pad) formed on the surface of the insulating layer 712. The surface of the insulating layer 712 may also have a polished surface. One surface of the metal layer 718 may be flush with the polished surface of the insulating layer 712.

In the printed wiring board 700 of this embodiment, the coreless resin substrate 710 is composed of a single interlayer insulating layer, but is not limited to this configuration and may have a structure in which multiple interlayer insulating layers are stacked. Via wiring 716 and metal layer 718 (post) may be formed in such an interlayer insulating layer as interlayer connection wiring. In this embodiment, the via wiring 716, metal layer 714, or metal layer 718 may be composed of a metal such as copper. The upper and lower surfaces of the coreless resin substrate 710 may be covered with solder resist layers (insulating layers 730, 732).

The method for manufacturing the printed wiring board 700 of this embodiment is not particularly limited, but the following method can be used, for example. For example, a copper post (e.g., metal layer 718) is formed on an insulating layer on a support substrate. The copper post is then further embedded in an insulating layer. Next, the surface of the copper post is exposed (i.e., the copper post is exposed) by a method such as grinding or chemical etching. Next, rewiring is formed by the SAP method. This process forms a coreless resin substrate 710 having an interlayer insulating layer. Thereafter, the process of forming the interlayer insulating layer may be repeated multiple times to stack multiple interlayer insulating layers having interlayer connection wiring. Then, a solder resist layer (insulating layers 730, 732) is formed. In this manner, the printed wiring board 700 can be obtained.

The above describes embodiments of the present invention, but these are merely examples of the present invention, and various configurations other than those described above can be adopted as long as they do not impair the effects of the present invention.

The present invention will be explained in more detail below using examples, but the present invention is not limited to these examples.

[Synthesis Example 1]
Polymerization was carried out in the same manner as in Synthesis Example 3, except that norbornene (75% toluene solution) was replaced with butylnorbornene under the conditions shown in Table 1 below. After completion of the reaction, 57 g of the reaction solution was diluted with 100 g of toluene and added dropwise to 200 g of methanol to cause reprecipitation. The precipitated polymer was recovered by filtration, and the residue was washed with 200 g of methanol and then filtered off. Finally, the mixture was vacuum dried at room temperature to obtain purified Polymer 1.
The composition ratio of butylnorbornene to 5-vinyl-2-norbornene in the obtained polymer 1 was calculated by ¹ H-NMR measurement to be 5:5.
The weight average molecular weight (Mw) of the obtained polymer 1 measured under the following conditions was 6,000, the number average molecular weight (Mn) was 2,500, and the molecular weight distribution (PDI: Mw/Mn) was 2.3.
(Measurement conditions)
The weight average molecular weight (Mw), number average molecular weight (Mn), and molecular weight distribution (PDI: Mw/Mn) of the obtained polymer 1 were determined from a calibration curve of standard polystyrene (PS) obtained by GPC measurement, and polystyrene-equivalent values were used. The measurement conditions were as follows:
Gel permeation chromatography device HLC-8320GPC manufactured by Tosoh Corporation
Column: TSK-GEL Supermultipore HZ-M manufactured by Tosoh Corporation
Detector: RI detector for liquid chromatography Measurement temperature: 40°C
Solvent: THF
Sample concentration: 2.0 mg/milliliter

[Synthesis Example 2]
Polymerization was carried out in the same manner as in Synthesis Example 3 using three monomers: norbornene, 5-vinyl-2-norbornene, and phenylethylnorbornene, under the conditions shown in Table 1 below. After completion of the reaction, 66 g of the reaction solution was added dropwise to 480 g of methanol to cause reprecipitation. The precipitated polymer was separated by filtration, air-dried, and then dissolved in 60 g of toluene and 110 g of THF. The dissolved liquid was added dropwise to 1,070 g of methanol to cause reprecipitation again, and the solution was separated by filtration. Finally, the mixture was vacuum-dried at room temperature to obtain purified Polymer 2.
The composition ratio of norbornene, phenylethylnorbornene and 5-vinyl-2-norbornene in the obtained polymer 2 was calculated by ¹ H-NMR measurement to be 3:1:1.
The weight average molecular weight (Mw) of the obtained polymer 2 measured under the above conditions was 2,700, the number average molecular weight (Mn) was 1,400, and the molecular weight distribution (PDI: Mw/Mn) was 2.0.

[Synthesis Example 3]
A reaction solution was obtained by adding norbornene (75% concentration toluene solution), 5-vinyl-2-norbornene, triethylsilane, 1-butanol, and anisole in the weight ratios shown in Table 1 below to a three-neck flask. After bubbling nitrogen through the reaction solution, it was heated to 75°C.
A catalyst (palladium (II) (acetonitrile) bis(triisopropylphosphine) acetate tetrakis(2,3,4,5,6-pentafluorophenyl)borate, Pd-1206) and a co-catalyst (N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate, DANFABA) were dissolved in a toluene:ethyl acetate = 6:4 solution to prepare a solution, and added to the reaction solution so that the ratio of norbornene monomer total: catalyst: co-catalyst = 20,000:1:1 (molar ratio). Polymerization was then carried out by heating at the reaction temperature and for the time shown in Table 1 below. After completion of polymerization, the reaction was stopped by allowing to cool.
After the reaction was completed, 110 g of the reaction solution was dropped into a mixture of 500 g of methanol and 150 g of THF to cause reprecipitation. The polymer was recovered by filtration, and then washed with a mixture of 100 g of methanol and 100 g of THF and filtered. Finally, the resulting mixture was vacuum dried at 80°C to obtain purified Polymer 3.
The weight average molecular weight (Mw) of the obtained polymer 3 measured under the above conditions was 2,200, the number average molecular weight (Mn) was 1,000, and the molecular weight distribution (PDI: Mw/Mn) was 2.2.

[Synthesis Example 4]
Polymerization was carried out in the same manner as in Synthesis Example 3, except that 5-vinyl-2-norbornene was replaced with butenylnorbornene under the conditions shown in Table 1 below. After completion of the reaction, 68 g of the reaction solution was added dropwise to 510 g of methanol to cause reprecipitation. The precipitated polymer was separated by filtration, air-dried, and then dissolved in 40 g of THF. The dissolved liquid was added dropwise to 430 g of methanol to cause reprecipitation again, and the solution was separated by filtration. Finally, the polymer was dried in a vacuum at room temperature to obtain purified Polymer 4.
The composition ratio of norbornene to butenylnorbornene in the obtained polymer 4 was calculated to be 3:1 by ¹ H-NMR measurement.
The weight average molecular weight (Mw) of the obtained polymer 4 measured under the above conditions was 2,700, the number average molecular weight (Mn) was 1,300, and the molecular weight distribution (PDI: Mw/Mn) was 2.2.

[Synthesis Example 5]
Polymerization was carried out in the same manner as in Synthesis Example 3, except that 5-vinyl-2-norbornene was replaced with hexenylnorbornene under the conditions shown in Table 1 below. After completion of the reaction, 113 g of the reaction solution was added dropwise to 850 g of methanol to cause reprecipitation. The precipitated polymer was separated by filtration, air-dried, and then dissolved in 90 g of toluene and 180 g of THF. The dissolved liquid was added dropwise to 2450 g of methanol to cause reprecipitation again, and the solution was separated by filtration. Finally, the polymer was dried in a vacuum at room temperature to obtain purified Polymer 5.
The composition ratio of norbornene to hexenylnorbornene in the obtained polymer 5 was calculated to be 3:1 by ¹ H-NMR measurement.
The weight average molecular weight (Mw) of the obtained polymer 5 measured under the above conditions was 3,100, the number average molecular weight (Mn) was 1,500, and the molecular weight distribution (PDI: Mw/Mn) was 2.0.

[Synthesis Example 6]
Polymerization was carried out in the same manner as in Synthesis Example 3 under the conditions shown in Table 1 below. After completion of the reaction, 580 g of the reaction solution was added dropwise to 1,400 g of methanol to cause reprecipitation. The precipitated polymer was separated by filtration, air-dried, and then dissolved in 350 g of toluene. The dissolved liquid was added dropwise to a mixed solution of 1,800 g of methanol and 360 g of THF to cause reprecipitation again, and the solution was separated by filtration. Finally, the mixture was dried in a vacuum at 80°C to obtain purified Polymer 6.

The components used in preparing the thermosetting resin composition are listed below.
(thermosetting resin)
Polymer 1: Polymer obtained in Synthesis Example 1 Polymer 2: Polymer obtained in Synthesis Example 2 Polymer 3: Polymer obtained in Synthesis Example 3 Polymer 4: Polymer obtained in Synthesis Example 4 Polymer 5: Polymer obtained in Synthesis Example 5

(epoxy resin)
Epoxy resin 1: naphthalene-modified cresol novolac epoxy resin (product name: EXA-7320, manufactured by DIC Corporation)

(cyanate resin)
Cyanate resin 1: Phenol novolac cyanate resin (product name: PT-30, manufactured by Lonza Japan)

(Crosslinking agent: liquid at room temperature (25°C))
Crosslinking agent 1: triallyl isocyanurate (number average molecular weight: 249, product name: TAIC, manufactured by Mitsubishi Chemical Corporation)
Crosslinking agent 2: Polybutadiene (number average molecular weight: 1200, product name: B-1000, manufactured by Nippon Petrochemical Co., Ltd.)
Crosslinking agent 3: styrene-butadiene rubber (styrene content: 25% by mass, number average molecular weight: 4500, product name: Ricon 100, manufactured by Cray Valley)

(Crosslinking agent: solid at room temperature (25°C))
Crosslinking agent 4: terminal methacrylic group-modified polyphenylene ether (number average molecular weight: 1,700, product name: SA-9000, manufactured by SABIC Innovative Plastics Japan, LLC)
Crosslinking agent 5: styrene-modified polyphenylene ether (number average molecular weight: 2,200, product name: OPE-2st-2200, manufactured by Mitsubishi Gas Chemical Co., Ltd.)

(Radical polymerization initiator)
Radical polymerization initiator 1: bis(t-butylperoxy)diisopropylbenzene (product name: Perbutyl P, manufactured by NOF Corporation)

(Curing accelerator)
Curing accelerator 1: 2-phenyl-4-methylimidazole (product name: 2P4MZ, manufactured by Shikoku Chemical Industries, Ltd.)

(Silica filler)
Silica filler 1: SC4050, manufactured by Admatechs Co., Ltd., particle size 1.1 μm

[Examples 1 to 10, Comparative Example 1]
Each component shown in Table 2 was dissolved or dispersed, and the nonvolatile content was adjusted to 60% by mass with toluene. The mixture was stirred using a high-speed stirrer to prepare a varnish-like thermosetting resin composition.
The prepared thermosetting resin composition was applied to a polyimide film and dried to obtain a 100 μm resin film. A polyimide film was placed on the resin film, and the resulting film was vacuum pressed under reduced pressure at 200 to 225° C. for 90 minutes at a pressure of 0.2 MPa.
After cooling to room temperature, the cured film was peeled off from the polyimide film to prepare a test specimen.
The dielectric properties (dielectric constant, dielectric loss tangent) and glass transition temperature of the obtained resin plate were measured by the following measuring methods. The results are shown in Table 1.

<Measurement of dielectric properties (relative permittivity, dielectric loss tangent) using the cavity resonator method>
The resin plates obtained in the examples were cooled to room temperature, and then the cured film was peeled off from the polyimide film to prepare test specimens.
The test piece was pretreated by placing it in an environment of 22±1° C. and 60±5% RH for 12 hours.
The measurement equipment used was a network analyzer HP8510C, a synthesized sweeper HP83651A, and a test set HP8517B (all manufactured by Agilent Technologies). The dimensions of the cylindrical cavity resonator were an inner diameter of 42 mm and a height of 30 mm, and the resonator was designed so that the TE ₀₁₁ mode was near 10 GHz when no sample was inserted.
The resonant frequency, 3 dB bandwidth, and transmitted power ratio were measured with and without a test piece inserted in the resonator. These measurement results were then analytically calculated using software to determine dielectric properties such as the dielectric loss tangent. The measurement mode was TE ₀₁₁ mode.

<Glass transition temperature>
The test piece was subjected to dynamic viscoelasticity measurement using a DMA apparatus (Q800, manufactured by TA Instruments) at a temperature rise rate of 5°C/min and a frequency of 1 Hz. The glass transition temperature was determined as the temperature at which the loss tangent tanδ was maximized.

As shown in Table 2, the thermosetting resin compositions according to the present invention obtained in the examples not only had excellent heat resistance, but also yielded cured products with low dielectric constants and dielectric dissipation factors and excellent dielectric properties. In other words, the thermosetting resin compositions according to the present invention yielded cured products with an excellent balance of these properties.

[Example 11]
Each component shown in Table 3 was dissolved or dispersed, and the nonvolatile content was adjusted to 60% by mass with toluene. The mixture was stirred using a high-speed stirrer to prepare a varnish-like thermosetting resin composition.
The prepared thermosetting resin composition was applied to copper foil and dried to obtain a 30 μm resin film. A glass cloth was sandwiched between two resin films, and the resulting substrate was vacuum pressed at 225° C. for 90 minutes under reduced pressure and a pressure of 3 MPa. The resulting substrate was etched to remove the copper foil, and this was used as a test piece for dielectric constant measurement.
The dielectric properties (dielectric constant, dielectric loss tangent) and glass transition temperature of the obtained test specimens were measured by the above-mentioned measuring methods. The results are shown in Table 3.

As shown in Table 3, the thermosetting resin composition containing the filler according to the present invention obtained in Example 11 not only had excellent heat resistance, but also yielded a cured product with low dielectric constant and dielectric dissipation factor, resulting in excellent dielectric properties. In other words, the thermosetting resin composition of the present invention was able to yield a cured product with an excellent balance of these properties.

10 Resin film 12 Carrier substrate 100 Resin film with carrier 105 Metal foil 300 Printed wiring board 301 Insulating layer 303 Metal layer 305 Insulating layer 307 Via hole 308 Electroless metal plating film 309 Electrolytic metal plating layer 400 Semiconductor device 401 Insulating layer 407 Semiconductor element 410 Solder bump 413 Sealant layer 500 Printed wiring board 510 Support substrate 520 Carrier foil 530 Metal foil 540 Insulating layer 542 Metal layer 550 Insulating layer 552 Metal layer 560 Insulating layer 562 Metal layer 600 Printed wiring board 610 Coreless resin substrate 612 Insulating layer 614 Metal layer 616 Via wiring 618 Metal layer 620 Semiconductor element 630 Insulating layer 632 Insulating layer 640 Metal layer 650 Metal layer 652 First metal layer 654 Second metal layer 700 Printed wiring board 710 Coreless resin substrate 712 Insulating layer 714 Metal layer 716 Via wiring 718 Metal layer 720 Semiconductor element 730 Insulating layer 732 Insulating layer 740 Metal layer

Claims (15)

(A) a thermosetting resin;
(B) a crosslinking agent;
Including,
The thermosetting resin (A) is
A structural unit a represented by the following general formula (1),
A structural unit b represented by the following general formula (2),
and having a weight average molecular weight of 500 or more and 10,000 or less ,
The thermosetting resin (A) does not contain a structural unit derived from ethylene or an α-olefin,
The crosslinking agent (B) is a thermosetting resin composition (excluding the case where a fluorine-containing polymer composed of polymerization units derived from a fluorine-containing monomer and polymerization units derived from a norbornene monomer having two or more carbon-carbon double bonds) comprising a crosslinking agent (b1) that is liquid at room temperature (25°C) and a crosslinking agent (b2) that is solid at room temperature (25°C) .
(In general formula (1), R ¹ , R ² , R ³ and R ⁴ each independently represent a hydrogen atom or a substituted or unsubstituted hydrocarbon group having 1 to 30 carbon atoms (excluding groups having a terminal double bond); and n is 0, 1 or 2.)
(In general formula (2), Q represents a group having a terminal double bond, R ¹ , R ² , and R ³ each independently represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and m is 0, 1, or 2.) The thermosetting resin composition according to claim 1, wherein the total amount of structural units a and structural units b in the thermosetting resin (A) is 80 mol % or more of all structural units. The thermosetting resin composition according to claim 1 or 2, wherein the group having a terminal double bond in Q of general formula (2) includes a vinyl group, an allyl group, a (meth)acryloyl group, a vinylphenyl group, or a maleimide group. The thermosetting resin composition according to any one of claims 1 to 3 , wherein the crosslinking agent (b1) comprises a crosslinking agent having two or more reactive groups. The thermosetting resin composition according to any one of claims 1 to 4 , wherein the crosslinking agent (b2) includes a crosslinking agent having a weight average molecular weight of 1,000 or more and 20,000 or less. The thermosetting resin composition according to any one of claims 1 to 5 , further comprising a radical polymerization initiator (C). The thermosetting resin composition according to any one of claims 1 to 6 , further comprising a filler (D). The thermosetting resin composition according to any one of claims 1 to 7 , which is used to form a resin film with a carrier, the resin film comprising a carrier base material and a resin film provided on at least one side of the carrier base material. The thermosetting resin composition according to any one of claims 1 to 7, which is used to form a resin layer in a prepreg containing a fiber substrate. The thermosetting resin composition according to claim 9 , wherein the fibrous substrate comprises glass cloth. A carrier substrate;
A resin film with a carrier, comprising: a resin film formed on the carrier substrate and made of the thermosetting resin composition according to any one of claims 1 to 7 . A prepreg comprising a fiber substrate in a resin layer made of the thermosetting resin composition according to any one of claims 1 to 7 . A laminate comprising the prepreg according to claim 12 and a metal layer disposed on at least one surface thereof. A printed wiring board comprising an insulating layer made of a cured product of the thermosetting resin composition according to any one of claims 1 to 7 . The printed wiring board according to claim 14 ;
a semiconductor element mounted on a circuit layer of the printed wiring board or embedded in the printed wiring board.