Resin composition

Abstract

To provide a resin composition capable of forming an insulating layer which has a low dielectric loss tangent, can suppress warpage, and has excellent adhesion to a conductor layer.SOLUTION: The resin composition contains (A) a first epoxy resin having a specific structure, (B) a second epoxy resin other than the first epoxy resin, (C) a curing agent, (D) a low elastic polymer, and (E) an inorganic filler.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a resin composition and a cured product thereof, a resin sheet, a circuit board, and a semiconductor device.

Background Art

[0002] Circuit boards such as printed wiring boards are widely used in various electronic devices. As a manufacturing method of a circuit board, a manufacturing method by a build-up method in which an insulating layer and a conductor layer are alternately stacked on an inner layer substrate is known. The insulating layer is formed, for example, by a cured product of a resin composition. Specifically, an insulating layer containing a cured product of a resin composition is formed by forming a resin composition layer containing the resin composition and curing the resin composition layer. As such a resin composition, an epoxy resin composition containing an epoxy resin has been known (Patent Documents 1 and 2).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] In general, the insulating layer is required to have a low dielectric loss tangent. However, when an epoxy resin for obtaining a low dielectric loss tangent is used, conventionally, the adhesion and warpage are inferior. Specifically, when an insulating layer using a conventional epoxy resin capable of obtaining a low dielectric loss tangent is provided on a circuit board, the warpage of the circuit board tends to increase. Further, when an epoxy resin capable of obtaining a low dielectric loss tangent while suppressing such warpage is used, the adhesion between the insulating layer and the conductor layer tends to be low.

[0005] The present invention was conceived in view of the above problems, and provides a resin composition capable of forming an insulating layer having a low dielectric tangent, capable of suppressing warpage, and having excellent adhesion to a conductor layer; a resin sheet containing the resin composition; a cured product of the resin composition; a circuit board containing the cured product of the resin composition; and a semiconductor device including the circuit board.

Means for Solving the Problems

[0006] The present inventors intensively studied to solve the above problems. As a result, the present inventors found that the above problems can be solved when a specific epoxy resin, an epoxy resin other than the specific epoxy resin, a curing agent, a low elastic polymer, and an inorganic filler are combined, and completed the present invention. That is, the present invention includes the following.

[0007] <1> A resin composition containing (A) a first epoxy resin represented by formula (A-1), (B) a second epoxy resin other than the first epoxy resin, (C) a curing agent, (D) a low elastic polymer, and (E) an inorganic filler.

Chemical formula

Advantages of the Invention

[0008] According to the present invention, there can be provided a resin composition capable of forming an insulating layer having a low dielectric tangent, capable of suppressing warpage, and excellent in adhesion to a conductor layer; a resin sheet containing the resin composition; a cured product of the resin composition; a circuit board containing the cured product of the resin composition; and a semiconductor device including the circuit board.

Embodiments for Carrying Out the Invention

[0009] Hereinafter, the present invention will be described with reference to embodiments and examples. However, the present invention is not limited to the embodiments and examples shown below, and may be modified and implemented without departing from the scope of the claims and their equivalents.

[0010] In this specification, the term "optionally having a substituent" with respect to a compound or a group means both the case where the hydrogen atom of the compound or group is not substituted with a substituent and the case where some or all of the hydrogen atoms of the compound or group are substituted with a substituent.

[0011] <Outline of the Resin Composition> The resin composition according to one embodiment of the present invention includes (A) a first epoxy resin represented by formula (A-1), (B) a second epoxy resin other than the first epoxy resin, (C) a curing agent, (D) a low-elastic polymer, and (E) an inorganic filler. In the following description, the "first epoxy resin represented by formula (A-1)" may be referred to as "(A) first epoxy resin", and the "second epoxy resin other than the first epoxy resin" may be referred to as "(B) second epoxy resin".

[0012]

Chemical formula

[0013] (In the above formula, R a1 each independently represents a hydrocarbon group having 1 to 8 carbon atoms; R a2 each independently represents a hydrogen atom, a dicyclopentenyl group represented by formula (A-2a) or formula (A-2b), a group represented by formula (A-3a), or a group represented by formula (A-3b); among at least two R a2 , one represents a dicyclopentenyl group represented by formula (A-2a) or formula (A-2b), and the other represents a group represented by formula (A-3a) or formula (A-3b); R a3 each independently represents a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms; R a4 each independently represents a hydrogen atom or a group represented by formula (A-3a); A a is the residue obtained by removing two R a2 from formula (A-1), and R a2 in the residue represents a hydrogen atom, a dicyclopentenyl group represented by formula (A-2a) or formula (A-2b), or a group represented by formula (A-3a); i a represents an integer from 0 to 2; n a represents the number of repetitions, and its average value is a number from 0 to 5; p a represents the number of repetitions, and its average value is a number from 0.01 to 3. * represents the bonding site.)

[0014] According to the above resin composition, an insulating layer with a low dielectric loss tangent, capable of suppressing warping, and having excellent adhesion to the conductor layer can be formed. Further, this resin composition can usually have a low minimum melt viscosity. The inventor conjectures the mechanism by which such excellent effects are obtained as follows. However, the technical scope of the present invention is not limited by the following mechanism.

[0015] (A) The first epoxy resin has a group R bonded to the benzene ring in the main chain a2Specifically, it contains a group represented by formula (A-3a) or formula (A-3b). As can be understood from the molecular skeleton, the group represented by formula (A-3a) or formula (A-3b) can move freely with respect to the main chain. Then, the group represented by formula (A-3a) or formula (A-3b) can easily enter between other molecules in the resin composition and can interfere with the interaction between these molecules. Therefore, as a result of the interaction between polar groups being hindered, it is possible to suppress the aggregation of polar sites and the occurrence of molecular orientation at a microscopic level due to the interaction between polar groups, so that the polarization bias of the entire resin composition can be suppressed. Therefore, since the polarity of the resin composition and its cured product can be reduced, the dielectric loss tangent of the insulating layer containing the cured product can be lowered.

[0016] On the other hand, since the group represented by formula (A-3a) or formula (A-3b) of the (A) first epoxy resin interferes with the interaction between molecules, in the cured product of the conventional resin composition containing the (A) first epoxy resin, the restraint of the molecular structure was small. Therefore, the cured product of the conventional resin composition tends to have a large degree of thermal expansion, and thus tends to have a large warpage due to thermal expansion. In contrast, in the present embodiment, the (D) low-elastic polymer and the (E) inorganic filler are combined with the (A) first epoxy resin to suppress warpage. The (D) low-elastic polymer can absorb the stress when stress is generated in the cured product due to thermal changes. In addition, the (E) inorganic filler generally has a smaller coefficient of thermal expansion than the resin component. Therefore, the suppression of warpage is achieved by these (D) low-elastic polymer and (E) inorganic filler.

[0017] In addition, since the group represented by the formula (A-3a) or (A-3b) of the (A) first epoxy resin hinders intermolecular interaction, the cured product of the conventional resin composition containing the (A) first epoxy resin tended to have low mechanical strength. When the mechanical strength of the cured product is low, delamination accompanied by the destruction of the cured product is likely to occur. On the other hand, in the present embodiment, a (B) second epoxy resin other than the (A) first epoxy resin is combined with the (A) first epoxy resin containing the group represented by the formula (A-3a) or (A-3b) that hinders intermolecular interaction. By combining the (B) second epoxy resin other than the (A) first epoxy resin in this way, the mechanical strength of the cured product can be increased, so that delamination accompanied by the destruction of the cured product can be suppressed. Therefore, the adhesion to the conductor layer can be enhanced.

[0018] Furthermore, as described above, since the group represented by the formula (A-3a) or (A-3b) of the (A) first epoxy resin hinders intermolecular interaction, the intermolecular binding force due to the interaction can be reduced. Thus, the fluidity of the molecules in the resin composition can be increased, and usually, the minimum melt viscosity of the resin composition can be reduced.

[0019] <(A) first epoxy resin> The resin composition according to the present embodiment contains a (A) first epoxy resin as a component (A). The (A) first epoxy resin is represented by the formula (A-1).

[0020]

Chemical formula

[0021] In the formula (A-1), R a1 each independently represents a hydrocarbon group having 1 to 8 carbon atoms. The hydrocarbon group represented by R a1 is preferably an alkyl group having 1 to 8 carbon atoms, an aryl group having 6 to 8 carbon atoms, an aralkyl group having 7 to 8 carbon atoms, or an allyl group. R a1The alkyl group in [description] may be linear, branched or cyclic. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, a t-butyl group, a hexyl group, a cyclohexyl group, a methylcyclohexyl group, and the like. R a1 Examples of the aryl group in [description] include a phenyl group, a tolyl group, a xylyl group, an ethylphenyl group, and the like. R a1 Examples of the aralkyl group in [description] include a benzyl group, an α-methylbenzyl group, and the like. Among these, from the viewpoints of availability and reactivity when forming a cured product, a phenyl group and a methyl group are preferred, and a methyl group is more preferred. (A) When the first epoxy resin contains a plurality of R a1 in one molecule, those R a1 may be the same or different. The bonding position of R a1 to the benzene ring may be any of the ortho position, meta position and para position, but the ortho position is preferred.

[0022] In formula (A-1), each R a2 independently represents a hydrogen atom, a dicyclopentenyl group, a group represented by formula (A-3a), or a group represented by formula (A-3b). Here, among at least two R a2 , one represents a dicyclopentenyl group, and the other represents a group represented by formula (A-3a) or formula (A-3b).

[0023] The dicyclopentenyl group is a group derived from dicyclopentadiene and is represented by formula (A-2а) or formula (A-2b). When the first epoxy resin (A) contains a plurality of dicyclopentenyl groups in one molecule, those dicyclopentenyl groups may be the same or different.

[0024]

Chemical formula

[0025] The group represented by formula (A-3a) or formula (A-3b) is as follows.

[0026]

Chem.

[0027] In formula (A-3a), R a3 each independently represents a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms. Examples of the hydrocarbon group having 1 to 8 carbon atoms in R a3 are the same as those of the hydrocarbon group having 1 to 8 carbon atoms in R a1 . Among them, from the viewpoint of the heat resistance of the cured product, R a3 is preferably a hydrogen atom, a methyl group, an ethyl group, or a vinyl group; more preferably a hydrogen atom, a methyl group, or an ethyl group; still more preferably a hydrogen atom or an ethyl group. When the first epoxy resin (A) contains a plurality of R a3 in one molecule, those R a3 may be the same or different. Among them, it is particularly preferable that one of the R a3 bonded to the common benzene ring is an ethyl group and the rest are hydrogen atoms. Further, the bonding position of the hydrocarbon group having 1 to 8 carbon atoms as R a3 to the benzene ring may be any of the ortho, meta, and para positions, but the meta and para positions are preferred.

[0028] In formula (A-3b), R a3 has the same meaning as R a3 in formula (A-3a).

[0029] In formula (A-3b), A a represents a divalent residue obtained by removing two R a2 from formula (A-1). R a2 in this divalent residue represents a hydrogen atom, a dicyclopentenyl group represented by formula (A-2a) or formula (A-2b), or a group represented by formula (A-3a). When the first epoxy resin (A) contains a plurality of A a in one molecule, those A a may be the same or different.

[0030] In formula (A-3b), R a4 each independently represents a hydrogen atom or a group represented by formula (A-3a). (A) When the first epoxy resin contains a plurality of R a4 in one molecule, those R a4 may be the same or different.

[0031] In formula (A-3b), p a represents a number of 0 or more representing the repeating number. The average value (number average) of p a is usually 0.01 to 3.0, preferably 0.1 to 2.0, more preferably 0.2 to 1.0, and still more preferably 0.3 to 0.8.

[0032] In formula (A-1), i a represents an integer of 0 to 2. i a represents the number of groups R a1 and is usually 0 to 2, preferably 1 or 2, and more preferably 2.

[0033] In formula (A-1), n a represents a number of 0 or more representing the repeating number. The average value (number average) of n a is usually 0 to 5.0, preferably 1.0 to 4.0, more preferably 1.1 to 3.0, and still more preferably 1.2 to 2.5.

[0034] (A) The first epoxy resin can be produced, for example, by reacting a polyhydric hydroxy resin represented by the following formula (A-4) with an epihalohydrin such as epichlorohydrin. For a specific production method, reference can be made to International Publication No. 2023 / 100572.

[0035]

Chemical formula

[0036] (In the above formula, R a5each independently represents a hydrogen atom, a dicyclopentenyl group represented by the formula (A-2a) or formula (A-2b), a group represented by the formula (A-3a), or a group represented by the formula (A-3c); at least two R a5 among them, one represents a dicyclopentenyl group represented by the formula (A-2a) or formula (A-2b), and the other represents a group represented by the formula (A-3a) or formula (A-3c); A a1 is a residue obtained by removing two R a5 from the formula (A-4), and R a5 in the residue represents a hydrogen atom, a dicyclopentenyl group represented by the formula (A-2a) or formula (A-2b), or a group represented by the formula (A-3a); other symbols are as described above. * represents a bonding site.)

[0037] (A) The epoxy equivalent of the first epoxy resin is preferably 200 g / eq. or more, more preferably 250 g / eq. or more, still more preferably 300 g / eq. or more, still more preferably 350 g / eq. or more, and preferably 4,000 g / eq. or less, more preferably 2,000 g / eq. or less, still more preferably 1,000 g / eq. or less, still more preferably 500 g / eq. or less. The epoxy equivalent represents the mass of the resin per equivalent of the epoxy group. This epoxy equivalent can be measured according to JIS K7236.

[0038] When GPC (gel permeation chromatography) measurement is performed, as the composition of the (A) first epoxy resin, in the formula (A-1), preferably, n a =0 species is 20 area% or less, n a =1 species is 40 area% - 90 area%, and n a =2 species or more is in the range of 0 area% - 60 area%.

[0039] (A) The total chlorine content of the first epoxy resin is preferably 2000 ppm or less, and more preferably 1500 ppm or less.

[0040] (A) The melt viscosity of the first epoxy resin at 150 °C is preferably 1.0 Pa·s or less, more preferably 0.7 Pa·s or less, still more preferably 0.5 Pa·s or less. The lower limit can be, for example, 0.01 Pa·s or more, 0.05 Pa·s or more, 0.1 Pa·s or more, etc.

[0041] (A) The first epoxy resin may be used alone or in combination of two or more.

[0042] (A) The range of the amount of the first epoxy resin is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, still more preferably 1% by mass or more, and preferably 20% by mass or less, more preferably 15% by mass or less, still more preferably 10% by mass or less, based on 100% by mass of the non-volatile components in the resin composition. Unless otherwise specified, the non-volatile components in the resin composition refer to the components excluding (J) the solvent in the resin composition. When the amount of the first epoxy resin is within the above range, reduction of the dielectric loss tangent, suppression of warpage, and improvement of adhesion can be effectively achieved, and usually, the minimum melt viscosity of the resin composition can be effectively reduced.

[0043] (A) The range of the amount of the first epoxy resin is preferably 1% by mass or more, more preferably 2% by mass or more, still more preferably 5% by mass or more, and preferably 50% by mass or less, more preferably 40% by mass or less, still more preferably 30% by mass or less, based on 100% by mass of the resin components in the resin composition. Unless otherwise specified, the resin components in the resin composition refer to the components excluding (E) the inorganic filler among the non-volatile components in the resin composition. When the amount of the first epoxy resin is within the above range, reduction of the dielectric loss tangent, suppression of warpage, and improvement of adhesion can be effectively achieved, and usually, the minimum melt viscosity of the resin composition can be effectively reduced.

[0044] (A) The amount of the first epoxy resin preferably ranges from 10% by mass or more, more preferably 20% by mass or more, still more preferably 30% by mass or more, particularly preferably 40% by mass or more, and preferably 90% by mass or less, more preferably 80% by mass or less, still more preferably 70% by mass or less, particularly preferably 60% by mass or less, based on 100% by mass of the total amount of (A) the first epoxy resin and (B) the second epoxy resin. When the amount of (A) the first epoxy resin is within the above range, reduction of the dielectric loss tangent, suppression of warpage, and improvement of adhesion can be effectively achieved, and further, usually, the minimum melt viscosity of the resin composition can be effectively reduced.

[0045] (A) The range of the mass ratio of the first epoxy resin to the low-elastic polymer ((A) the first epoxy resin / (D) the low-elastic polymer) is preferably 0.1 or more, more preferably 0.2 or more, still more preferably 0.3 or more, particularly preferably 0.5 or more, and preferably 3.0 or less, more preferably 2.0 or less, still more preferably 1.5 or less, particularly preferably 1.0 or less. When the mass ratio ((A) the first epoxy resin / (D) the low-elastic polymer) is within the above range, reduction of the dielectric loss tangent, suppression of warpage, and improvement of adhesion can be effectively achieved, and further, usually, the minimum melt viscosity of the resin composition can be effectively reduced.

[0046] (A) The range of the mass ratio of the total amount of the first epoxy resin and the second epoxy resin to the low-elastic polymer ((A) the total amount of the first epoxy resin and (B) the second epoxy resin / (D) the low-elastic polymer) is preferably 0.2 or more, more preferably 0.5 or more, still more preferably 0.8 or more, particularly preferably 1.2 or more, and preferably 10 or less, more preferably 8 or less, still more preferably 5 or less, particularly preferably 3 or less. When the mass ratio ((A) the total amount of the first epoxy resin and (B) the second epoxy resin / (D) the low-elastic polymer) is within the above range, reduction of the dielectric loss tangent, suppression of warpage, and improvement of adhesion can be effectively achieved, and further, usually, the minimum melt viscosity of the resin composition can be effectively reduced.

[0047] (A) The total amount of the first epoxy resin and (D) the low-elasticity polymer preferably ranges from 3% by mass or more, more preferably 6% by mass or more, still more preferably 8% by mass or more, and particularly preferably 10% by mass or more, to 30% by mass or less, more preferably 25% by mass or less, still more preferably 20% by mass or less, and particularly preferably 18% by mass or less, based on 100% by mass of the inorganic filler (E). When the total amount of (A) the first epoxy resin and (D) the low-elasticity polymer is within the above range, reduction of the dielectric loss tangent, suppression of warpage, and improvement of adhesion can be effectively achieved, and furthermore, usually, the minimum melt viscosity of the resin composition can be effectively reduced.

[0048] <(B) Second epoxy resin> The resin composition according to this embodiment contains (B) the second epoxy resin as the component (B). The (B) second epoxy resin represents an epoxy resin other than the (A) first epoxy resin. Therefore, the (B) second epoxy resin represents a resin other than those represented by the above formula (A-1) among epoxy resins as resins containing epoxy groups. The (B) second epoxy resin may be used alone or in combination of two or more.

[0049] (B) Examples of the second epoxy resin include a bixylenol type epoxy resin, a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a bisphenol S type epoxy resin, a bisphenol AF type epoxy resin, a dicyclopentadiene type epoxy resin, a trisphenol type epoxy resin, a naphthol novolak type epoxy resin, a phenol novolak type epoxy resin, a tert-butyl-catechol type epoxy resin, a naphthalene type epoxy resin, a naphthol type epoxy resin, an anthracene type epoxy resin, a glycidylamine type epoxy resin, a glycidyl ester type epoxy resin, a cresol novolak type epoxy resin, a phenol aralkyl type epoxy resin, a biphenyl type epoxy resin, a linear aliphatic epoxy resin, an epoxy resin having a butadiene structure, an alicyclic epoxy resin, a heterocyclic epoxy resin, a spiro ring-containing epoxy resin, a cyclohexane type epoxy resin, a cyclohexanedimethanol type epoxy resin, a naphthylene ether type epoxy resin, a trimethylol type epoxy resin, a tetraphenylethane type epoxy resin, an isocyanurate type epoxy resin, a phenolphthalimide type epoxy resin, and the like.

[0050] (B) The second epoxy resin preferably contains an epoxy resin containing an aromatic structure, and may contain only an epoxy resin containing an aromatic structure. The aromatic structure is a chemical structure generally defined as an aromatic, and includes polycyclic aromatics and aromatic heterocycles. Examples of the epoxy resin containing an aromatic structure include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bisphenol AF type epoxy resin, dicyclopentadiene type epoxy resin, trisphenol type epoxy resin, naphthol novolak type epoxy resin, phenol novolak type epoxy resin, tert-butyl-catechol type epoxy resin, naphthalene type epoxy resin, naphthol type epoxy resin, anthracene type epoxy resin, biscylenol type epoxy resin, phenolphthalimide type epoxy resin, glycidylamine type epoxy resin having an aromatic structure, glycidyl ester type epoxy resin having an aromatic structure, cresol novolak type epoxy resin, biphenyl type epoxy resin, linear aliphatic epoxy resin having an aromatic structure, epoxy resin having a butadiene structure having an aromatic structure, alicyclic epoxy resin having an aromatic structure, heterocyclic epoxy resin, spiro ring-containing epoxy resin having an aromatic structure, cyclohexanedimethanol type epoxy resin having an aromatic structure, naphthylene ether type epoxy resin, trimethylol type epoxy resin having an aromatic structure, tetraphenylethane type epoxy resin having an aromatic structure, and the like. Among them, (B) the second epoxy resin more preferably contains one or more selected from the group consisting of bisphenol A type epoxy resin, bisphenol F type epoxy resin, naphthalene type epoxy resin, biscylenol type epoxy resin, biphenyl type epoxy resin, naphthylene ether type epoxy resin, and phenolphthalimide type epoxy resin.

[0051] (B) The second epoxy resin preferably contains an epoxy resin having two or more epoxy groups in one molecule. With respect to 100% by mass of the non-volatile component of the (B) second epoxy resin, the proportion of the epoxy resin having two or more epoxy groups in one molecule is preferably 50% by mass or more, more preferably 60% by mass or more, and still more preferably 70% by mass or more.

[0052] (B) The second epoxy resin includes a liquid epoxy resin (hereinafter sometimes referred to as "liquid epoxy resin") that is liquid at 20°C and a solid epoxy resin (hereinafter sometimes referred to as "solid epoxy resin") that is solid at 20°C. (B) The second epoxy resin may contain only the liquid epoxy resin, may contain only the solid epoxy resin, or may contain a combination of the liquid epoxy resin and the solid epoxy resin.

[0053] As the liquid epoxy resin, a liquid epoxy resin having two or more epoxy groups in one molecule is preferable. Preferred liquid epoxy resins include bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol AF type epoxy resins, naphthalene type epoxy resins, glycidyl ester type epoxy resins, glycidyl amine type epoxy resins, phenol novolac type epoxy resins, alicyclic epoxy resins having an ester skeleton, cyclohexane type epoxy resins, cyclohexanedimethanol type epoxy resins, and epoxy resins having a butadiene structure; bisphenol A type epoxy resins, bisphenol F type epoxy resins, and naphthalene type epoxy resins are more preferable.

[0054] Specific examples of the liquid epoxy resin include "HP-4032", "HP-4032-D", "HP-4032-SS" (naphthalene-type epoxy resin) manufactured by DIC Corporation; "828US", "828EL", "jER828EL", "825", "Epicoat 828EL" (bisphenol A-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "jER807", "1750" (bisphenol F-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "jER152" (phenol novolac-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "630", "630LSD", "604" (glycidylamine-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "ED-523T" (glycerol-type epoxy resin) manufactured by ADEKA Corporation; "EP-3950L", "EP-3980S" (glycidylamine-type epoxy resin) manufactured by ADEKA Corporation; "EP-4088S" (dicyclopentadiene-type epoxy resin) manufactured by ADEKA Corporation; "ZX1059" (a mixture of bisphenol A-type epoxy resin and bisphenol F-type epoxy resin) manufactured by Nippon Steel Chemical & Material Co., Ltd.; "EX-721" (glycidyl ester-type epoxy resin) manufactured by Nagase ChemteX Corporation; "Celoxide 2021P" (alicyclic epoxy resin having an ester skeleton) manufactured by Daicel Corporation; "PB-3600", "JP-100", "JP-200" (epoxy resin having a butadiene structure) manufactured by Nippon Soda Co., Ltd.; "ZX1658", "ZX1658GS" (liquid 1,4-glycidylcyclohexane-type epoxy resin) manufactured by Nippon Steel Chemical & Material Co., Ltd., and the like.

[0055] As the solid epoxy resin, a solid epoxy resin having three or more epoxy groups in one molecule is preferable, and an aromatic solid epoxy resin having three or more epoxy groups in one molecule is more preferable. Examples of the solid epoxy resin include a vixylenol type epoxy resin, a naphthalene type epoxy resin, a naphthalene type tetrafunctional epoxy resin, a naphthol novolak type epoxy resin, a cresol novolak type epoxy resin, a dicyclopentadiene type epoxy resin, a trisphenol type epoxy resin, a naphthol type epoxy resin, a biphenyl type epoxy resin, a naphthylene ether type epoxy resin, an anthracene type epoxy resin, a bisphenol A type epoxy resin, a bisphenol AF type epoxy resin, a phenol aralkyl type epoxy resin, a tetraphenylethane type epoxy resin, and a phenol phthalimide type epoxy resin; a vixylenol type epoxy resin, a biphenyl type epoxy resin, a naphthylene ether type epoxy resin, and a phenol phthalimide type epoxy resin are more preferable; a vixylenol type epoxy resin and a naphthalene type epoxy resin are even more preferable.

[0056] Specific examples of the solid epoxy resin include "HP4032H" (naphthalene-type epoxy resin) manufactured by DIC Corporation; "HP-4700", "HP-4710" (naphthalene-type tetrafunctional epoxy resin) manufactured by DIC Corporation; "N-690" (cresol novolak-type epoxy resin) manufactured by DIC Corporation; "N-695" (cresol novolak-type epoxy resin) manufactured by DIC Corporation; "HP-7200", "HP-7200HH", "HP-7200H", "HP-7200L" (dicyclopentadiene-type epoxy resin) manufactured by DIC Corporation; "EXA-7311", "EXA-7311-G3", "EXA-7311-G4", "EXA-7311-G4S", "HP6000" (naphthylene ether-type epoxy resin) manufactured by DIC Corporation; "EPPN-502H" (trisphenol-type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.; "NC7000L" (naphthol novolak-type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.; "NC3000H", "NC3000", "NC3000L", "NC3000FH", "NC3100" (biphenyl-type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.; "ESN475V", "ESN4100V" (naphthalene-type epoxy resin) manufactured by Nippon Steel Chemical & Material Co., Ltd.; "ESN485" (naphthol-type epoxy resin) manufactured by Nippon Steel Chemical & Material Co., Ltd.; "ESN375" (dihydroxynaphthalene-type epoxy resin) manufactured by Nippon Steel Chemical & Material Co., Ltd.; "YX4000H", "YX4000", "YX4000HK", "YL7890" (bixylenol-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "YL6121" (biphenyl-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "YX8800" (anthracene-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "YX7700" (phenol aralkyl-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "PG-100", "CG-500" manufactured by Osaka Gas Chemical Co., Ltd.; "YX7760" (bisphenol AF-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "YL7800" (fluorene-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "jER1010" (bisphenol A-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "jER1031S" (tetraphenylethane-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "WHR991S" (phenolphthalimide-type epoxy resin) manufactured by Nippon Kayaku Co., Ltd., and the like.

[0057] (B) When the second epoxy resin contains a combination of a liquid epoxy resin and a solid epoxy resin, their mass ratio (liquid epoxy resin: solid epoxy resin) is preferably 20:1 to 1:20, more preferably 10:1 to 1:10, and particularly preferably 7:1 to 1:7.

[0058] (B) The range of the epoxy equivalent of the second epoxy resin is preferably 50 g / eq. to 5,000 g / eq., more preferably 60 g / eq. to 3,000 g / eq., still more preferably 80 g / eq. to 2,000 g / eq., and particularly preferably 110 g / eq. to 1,000 g / eq.

[0059] (B) The range of the weight average molecular weight (Mw) of the second epoxy resin is preferably 100 to 5,000, more preferably 250 to 3,000, and still more preferably 400 to 1,500. The weight average molecular weight can be measured as a value in terms of polystyrene by the gel permeation chromatography (GPC) method.

[0060] (B) The range of the amount of the second epoxy resin is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and particularly preferably 1% by mass or more, and preferably 20% by mass or less, more preferably 15% by mass or less, and still more preferably 10% by mass or less, based on 100% by mass of the non-volatile components in the resin composition. When the amount of the (B) second epoxy resin is within the above range, reduction of the dielectric loss tangent, suppression of warping, and improvement of adhesion can be effectively achieved, and usually, the minimum melt viscosity of the resin composition can be effectively reduced.

[0061] (B) The range of the amount of the second epoxy resin is preferably 1% by mass or more, more preferably 2% by mass or more, and particularly preferably 5% by mass or more, and preferably 50% by mass or less, more preferably 40% by mass or less, and particularly preferably 30% by mass or less, based on 100% by mass of the resin components in the resin composition. When the amount of the (B) second epoxy resin is within the above range, reduction of the dielectric loss tangent, suppression of warping, and improvement of adhesion can be effectively achieved, and usually, the minimum melt viscosity of the resin composition can be effectively reduced.

[0062] (B) The mass ratio of the second epoxy resin to the (D) low-elastic polymer ((B) second epoxy resin / (D) low-elastic polymer) preferably ranges from 0.01 or more, more preferably 0.05 or more, still more preferably 0.1 or more, and preferably 5.0 or less, more preferably 4.0 or less, still more preferably 3.0 or less. When the mass ratio ((B) second epoxy resin / (D) low-elastic polymer) is within the above range, reduction of the dielectric loss tangent, suppression of warpage, and improvement of adhesion can be effectively achieved, and further, usually, the minimum melt viscosity of the resin composition can be effectively reduced.

[0063] <(C) curing agent> The resin composition according to the present embodiment contains a (C) curing agent as the component (C). The (C) curing agent can react with epoxy resins such as the (A) first epoxy resin and the (B) second epoxy resin to form bonds and cure the resin composition. The (C) curing agent does not include those corresponding to the above-described components (A) to (B). The (C) curing agent may be used alone or in combination of two or more.

[0064] Examples of the (C) curing agent include active ester resins, phenolic resins, carbodiimide resins, cyanate resins, benzoxazine resins, acid anhydride resins, amine resins, thiol resins, etc. Among them, active ester resins, phenolic resins, carbodiimide resins, and cyanate resins are preferred.

[0065] As the active ester resin, a resin having one or more, preferably two or more active ester groups in one molecule can be used. Among them, as the active ester resin, a resin having two or more highly reactive ester groups such as phenol esters, thiophenol esters, N-hydroxyamine esters, and esters of heterocyclic hydroxy compounds in one molecule is preferred.

[0066] The active ester resin is preferably obtained by a condensation reaction of a carboxylic acid compound and / or a thiocarboxylic acid compound with a hydroxy compound and / or a thiol compound. Particularly from the viewpoint of improving heat resistance, an active ester resin obtained from a carboxylic acid compound and a hydroxy compound is preferred, and an active ester resin obtained from a carboxylic acid compound and a phenol compound and / or a naphthol compound is more preferred. Examples of the carboxylic acid compound include benzoic acid, acetic acid, succinic acid, maleic acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, pyromellitic acid, and the like. Examples of the phenol compound or naphthol compound include hydroquinone, resorcinol, bisphenol A, bisphenol F, bisphenol S, phenolphthalin, methylated bisphenol A, methylated bisphenol F, methylated bisphenol S, phenol, o-cresol, m-cresol, p-cresol, catechol, α-naphthol, β-naphthol, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, phloroglucin, benzenetriol, dicyclopentadiene-type diphenol compounds, phenol novolac, and the like. Here, the "dicyclopentadiene-type diphenol compound" refers to a diphenol compound obtained by condensing two molecules of phenol with one molecule of dicyclopentadiene.

[0067] Specifically, as the active ester resin, a dicyclopentadiene-type active ester resin, a naphthalene-type active ester resin containing a naphthalene structure, an active ester resin containing an acetylated product of phenol novolac, and an active ester resin containing a benzoylated product of phenol novolac are preferred, and among them, the naphthalene-type active ester resin is more preferred. As the dicyclopentadiene-type active ester resin, an active ester resin containing a dicyclopentadiene-type diphenol structure is preferred.

[0068] Examples of commercially available active ester resins include, for example, as active ester resins containing a dicyclopentadiene type diphenol structure, "EXB9451", "EXB9460", "EXB9460S", "EXB-8000L", "EXB-8000L-65M", "EXB-8000L-65TM", "HPC-8000L-65TM", "HPC-8000", "HPC-8000-65T", "HPC-8000H", "HPC-8000H-65TM" (manufactured by DIC Corporation); as active ester resins containing a naphthalene structure, "HP-B-8151-62T", "EXB-8100L-65T", "EXB-8150-60T", "EXB-8150-62T", "EXB-9416-70BK", "HPC-8150-60T", "HPC-8150-62T", "HPC-8151-62T" (manufactured by DIC Corporation); as phosphorus-containing active ester resins, "EXB9401" (manufactured by DIC Corporation); as active ester resins that are acetylated products of phenol novolac, "DC808" (manufactured by Mitsubishi Chemical Corporation); as active ester resins that are benzoylated products of phenol novolac, "YLH1026", "YLH1030", "YLH1048" (manufactured by Mitsubishi Chemical Corporation); as active ester resins containing a styryl group and a naphthalene structure, "PC1300-02-65MA" (manufactured by Air Water, Inc.), and the like.

[0069] The range of the amount of the active ester resin is preferably 5% by mass or more, more preferably 10% by mass or more, still more preferably 15% by mass or more, and preferably 50% by mass or less, more preferably 40% by mass or less, still more preferably 30% by mass or less, based on 100% by mass of the resin component in the resin composition. When the amount of the active ester resin is within the above range, reduction of the dielectric loss tangent, suppression of warpage, and improvement of adhesion can be effectively achieved, and further, usually, the minimum melt viscosity of the resin composition can be effectively reduced.

[0070] As the phenolic resin, a resin having one or more, preferably two or more hydroxyl groups (phenolic hydroxyl groups) bonded to an aromatic ring such as a benzene ring or a naphthalene ring in one molecule can be used. From the viewpoints of heat resistance and water resistance, a phenolic resin having a novolak structure is preferred. Further, from the viewpoint of adhesion, a nitrogen-containing phenolic resin is preferred, and a phenolic resin containing a triazine skeleton is more preferred. Among them, from the viewpoint of highly satisfying heat resistance, water resistance, and adhesion, a phenolic novolak resin containing a triazine skeleton is preferred.

[0071] Specific examples of the phenolic resin include "MEH-7700", "MEH-7810", "MEH-7851", "MEH-8000H" manufactured by Meiwa Kasei Co., Ltd.; "NHN", "CBN", "GPH" manufactured by Nippon Kayaku Co., Ltd.; "SN-170", "SN-180", "SN-190", "SN-475", "SN-485", "SN-495", "SN-495V", "SN-375", "SN-395" manufactured by Nippon Steel Chemical & Material Co., Ltd.; "TD-2090", "TD-2090-60M", "LA-7052", "LA-7054", "LA-1356", "LA-3018", "LA-3018-50P", "LA-1356", "TD2090", "TD-2090-60M" manufactured by DIC Corporation; "GDP-6115L", "GDP-6115H", "ELPC75" manufactured by Gunei Chemical Industry Co., Ltd., and the like.

[0072] The range of the amount of the phenolic resin is preferably 0.1% by mass or more, more preferably 1% by mass or more, particularly preferably 2% by mass or more, and preferably 30% by mass or less, more preferably 20% by mass or less, particularly preferably 10% by mass or less with respect to 100% by mass of the resin component in the resin composition. When the amount of the phenolic resin is within the above range, reduction of the dielectric loss tangent, suppression of warping, and improvement of adhesion can be effectively achieved, and further, usually, the minimum melt viscosity of the resin composition can be effectively reduced.

[0073] As the carbodiimide resin, a resin having one or more, preferably two or more carbodiimide structures in one molecule can be used. Specific examples of the carbodiimide resin include aliphatic biscarbodiimides such as tetramethylene-bis(t-butylcarbodiimide) and cyclohexane bis(methylene-t-butylcarbodiimide); biscarbodiimides such as aromatic biscarbodiimides like phenylene-bis(xilylcarbodiimide); aliphatic polycarbodiimides such as polyhexamethylene carbodiimide, polytrimethylhexamethylene carbodiimide, polycyclohexylene carbodiimide, poly(methylenebiscyclohexylene carbodiimide), and poly(isophorone carbodiimide); aromatic polycarbodiimides such as poly(phenylene carbodiimide), poly(naphthylene carbodiimide), poly(tolylene carbodiimide), poly(methyldiisopropylphenylene carbodiimide), poly(triethylphenylene carbodiimide), poly(diethylphenylene carbodiimide), poly(triisopropylphenylene carbodiimide), poly(diisopropylphenylene carbodiimide), poly(xilylene carbodiimide), poly(tetramethylxilylene carbodiimide), poly(methylenediphenylene carbodiimide), and poly[methylenebis(methylphenylene) carbodiimide]. Commercially available products of the carbodiimide resin include, for example, "Carbodilite V-02B", "Carbodilite V-03", "Carbodilite V-04K", "Carbodilite V-05", "Carbodilite V-07", and "Carbodilite V-09" manufactured by Nisshinbo Chemical Inc.; "Stabaxol P", "Stabaxol P400", "Highcadil 510", etc. manufactured by LANXESS.

[0074] The amount range of the carbodiimide resin is preferably 0.1% by mass or more, more preferably 1% by mass or more, still more preferably 2% by mass or more, and preferably 20% by mass or less, more preferably 10% by mass or less, still more preferably 5% by mass or less, based on 100% by mass of the resin components in the resin composition. When the amount of the carbodiimide resin is within the above range, reduction of the dielectric tangent, suppression of warpage, and improvement of adhesion can be effectively achieved, and further, usually, the minimum melt viscosity of the resin composition can be effectively reduced.

[0075] As the cyanate resin, a resin having one or more, preferably two or more cyanate groups in one molecule can be used. Examples of the cyanate resin include bifunctional cyanate resins such as bisphenol A dicyanate, polyphenol cyanate, oligo(3-methylene-1,5-phenylene cyanate), 4,4'-methylenebis(2,6-dimethylphenyl cyanate), 4,4'-ethylidenediphenyl dicyanate, hexafluorobisphenol A dicyanate, 2,2-bis(4-cyanate)phenylpropane, 1,1-bis(4-cyanatephenylmethane), bis(4-cyanate-3,5-dimethylphenyl)methane, 1,3-bis(4-cyanatephenyl-1-(methylethylidene))benzene, bis(4-cyanatephenyl)thioether, and bis(4-cyanatephenyl)ether; polyfunctional cyanate resins derived from phenol novolak and cresol novolak; prepolymers in which some of these cyanate resins are triazine-ized; and the like. Specific examples of the cyanate resin include "PT30" and "PT60" (phenol novolak type polyfunctional cyanate resins), "BA230", and "BA230S75" (prepolymers in which part or all of bisphenol A dicyanate is triazine-ized to form trimers) manufactured by Lonza.

[0076] The amount of the cyanate resin is preferably 0.1% by mass or more, more preferably 1% by mass or more, and even more preferably 5% by mass or more, and is preferably 40% by mass or less, more preferably 30% by mass or less, and even more preferably 20% by mass or less, based on 100% by mass of the resin components in the resin composition. When the amount of the cyanate resin is within the above range, it is possible to effectively achieve a reduction in the dielectric tangent, suppression of warping, and improvement in adhesion, and moreover, usually, the minimum melt viscosity of the resin composition can be effectively reduced.

[0077] The benzoxazine resin may be a resin having one or more, preferably two or more, benzoxazine rings in one molecule. Specific examples of the benzoxazine resin include "JBZ-OP100D" and "ODA-BOZ" manufactured by JFE Chemical Corporation, "HFB2006M" manufactured by Showa Polymer Co., Ltd., and "Pd", "Fa", and "ALP-d" manufactured by Shikoku Chemical Industry Co., Ltd.

[0078] As the acid anhydride resin, a resin having one or more, preferably two or more acid anhydride groups in one molecule can be used. Specific examples of the acid anhydride resin include phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methyl nadic anhydride, hydrogenated methyl nadic anhydride, trialkyltetrahydrophthalic anhydride, dodecenyl succinic anhydride, 5-(2,5-dioxotetrahydro-3-furanyl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, trimellitic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic dianhydride, biphenyltetracarboxylic dianhydride, naphthalene tetracarboxylic dianhydride, oxydiphthalic dianhydride, 3,3'-4,4'-diphenylsulfone tetracarboxylic dianhydride, 1,3,3a,4,5,9b-hexahydro-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphtho[1,2-c]furan-1,3-dione, ethylene glycol bis(anhydrotrimellitate), polymer type acid anhydrides such as styrene-maleic acid resin copolymerized from styrene and maleic acid, and the like. Commercially available products of the acid anhydride resin include, for example, "HNA-100", "MH-700", "MTA-15", "DDSA", "OSA" manufactured by Shin Nippon Rika Co., Ltd.; "YH-306", "YH-307" manufactured by Mitsubishi Chemical Corporation; "HN-2200" manufactured by Resonaak Co., Ltd.; "EF-30", "EF-40", "EF-60", "EF-80" manufactured by Cray Valley Co., Ltd., and the like.

[0079] As the amine resin, a resin having one or more, preferably two or more amino groups in one molecule can be used. Examples of the amine resin include aliphatic amines, polyether amines, alicyclic amines, aromatic amines, etc. Among them, aromatic amines are preferred. The amine resin is preferably a primary amine or a secondary amine, and more preferably a primary amine. Specific examples of the amine resin include 4,4'-methylenebis(2,6-dimethylaniline), 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfone, 3,3'-diaminodiphenylsulfone, m-phenylenediamine, m-xylylenediamine, diethyltoluenediamine, 4,4'-diaminodiphenyl ether, 3,3'-dimethyl-4,4'-diaminobiphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dihydroxybenzidine, 2,2-bis(3-amino-4-hydroxyphenyl)propane, 3,3-dimethyl-5,5-diethyl-4,4-diphenylmethanediamine, 2,2-bis(4-aminophenyl)propane, 2,2-bis(4-(4-aminophenoxy)phenyl)propane, 1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, bis(4-(4-aminophenoxy)phenyl)sulfone, bis(4-(3-aminophenoxy)phenyl)sulfone, etc. Commercially available products of the amine resin include, for example, "SEIKACURE-S" manufactured by Seika Corporation; "KAYABOND C-200S", "KAYABOND C-100", "KAYAHARD A-A", "KAYAHARD A-B", "KAYAHARD A-S" manufactured by Nippon Kayaku Co., Ltd.; "EPICURE W" manufactured by Mitsubishi Chemical Corporation; "DTDA" manufactured by Sumitomo Seika Chemicals Co., Ltd., etc.

[0080] Examples of the thiol resin include trimethylolpropane tris(3-mercaptopropionate), pentaerythritol tetrakis(3-mercaptobutyrate), tris(3-mercaptopropyl)isocyanurate, etc.

[0081] (C) The active group equivalent weight of the curing agent is preferably from 50 g / eq. to 3,000 g / eq., more preferably from 100 g / eq. to 1,000 g / eq., still more preferably from 100 g / eq. to 500 g / eq., and particularly preferably from 100 g / eq. to 300 g / eq. The active group equivalent weight represents the mass of the resin per equivalent of the active group. For example, the active group equivalent weight of a phenolic resin represents the phenolic hydroxyl group equivalent weight, which represents the mass of the resin per equivalent of the phenolic hydroxyl group.

[0082] (C) The range of the weight average molecular weight (Mw) of the curing agent may be the same as the range of the weight average molecular weight (Mw) of (B) the second epoxy resin.

[0083] (C) When the total number of epoxy groups of (A) the first epoxy resin and (B) the second epoxy resin is taken as 1, the number of active groups of the curing agent (C) is preferably 0.1 or more, more preferably 0.2 or more, and particularly preferably 0.5 or more, and is preferably 10 or less, more preferably 5 or less, and still more preferably 2 or less. The "number of epoxy groups of (A) the first epoxy resin" in the resin composition represents the total value obtained by summing up all the values obtained by dividing the mass of the non-volatile component of (A) the first epoxy resin present in the resin composition by its epoxy equivalent weight. Also, the "number of epoxy groups of (B) the second epoxy resin" in the resin composition represents the total value obtained by summing up all the values obtained by dividing the mass of the non-volatile component of (B) the second epoxy resin present in the resin composition by its epoxy equivalent weight. Further, the "number of active groups of (C) the curing agent" in the resin composition represents the total value obtained by summing up all the values obtained by dividing the mass of the non-volatile component of (C) the curing agent present in the resin composition by its active group equivalent weight.

[0084] (C) The amount range of the curing agent is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, still more preferably 1% by mass or more, and preferably 30% by mass or less, more preferably 20% by mass or less, and still more preferably 15% by mass or less, based on 100% by mass of the non-volatile components in the resin composition. When the amount of (C) the curing agent is within the above range, reduction of the dielectric loss tangent, suppression of warpage, and improvement of adhesion can be effectively achieved, and furthermore, usually, the minimum melt viscosity of the resin composition can be effectively reduced.

[0085] (C) The amount range of the curing agent is preferably 1% by mass or more, more preferably 2% by mass or more, particularly preferably 5% by mass or more, and preferably 60% by mass or less, more preferably 50% by mass or less, still more preferably 40% by mass or less, based on 100% by mass of the resin component in the resin composition. When the amount of (C) the curing agent is within the above range, reduction of the dielectric loss tangent, suppression of warping, and improvement of adhesion can be effectively achieved, and furthermore, usually, the minimum melt viscosity of the resin composition can be effectively reduced.

[0086] <(D) Low-elasticity polymer> The resin composition according to the present embodiment contains a (D) low-elasticity polymer as the component (D). The (D) low-elasticity polymer is a polymer having a low elastic modulus. Usually, the (D) low-elasticity polymer is contained in the resin composition in a state compatible with resin components such as the components (A) to (C), and is contained in the cured product while maintaining the compatible state. The (D) low-elasticity polymer does not include those corresponding to the above-mentioned components (A) to (C). The (D) low-elasticity polymer may be used alone or in combination of two or more.

[0087] (D) The low-elasticity polymer usually has a low elastic modulus. Specifically, when a tensile test is performed in accordance with Japanese Industrial Standard (JIS K7161) at a temperature of 25°C and a humidity of 40% RH, the (D) low-elasticity polymer usually exhibits an elastic modulus of 1 GPa or less. The range of the elastic modulus of the (D) low-elasticity polymer is, in detail, usually 1 GPa or less, preferably 0.9 GPa or less, more preferably 0.8 GPa or less, still more preferably 0.7 GPa or less, and preferably 0.01 GPa or more, more preferably 0.03 GPa or more, still more preferably 0.05 GPa or more, particularly preferably 0.1 GPa or more.

[0088] (D) Since the low-elasticity polymer is a polymer, it usually has a large weight-average molecular weight. The range of the weight-average molecular weight Mw of the (D) low-elasticity polymer is preferably greater than 5,000, more preferably 8,000 or more, and still more preferably 10,000 or more. The upper limit is preferably 1,000,000 or less, more preferably 500,000 or less, still more preferably 200,000 or less, still more preferably 100,000 or less, still more preferably 50,000 or less, and still more preferably 30,000 or less.

[0089] (D) As the low-elasticity polymer, a resin containing one or more selected from the group consisting of a polybutadiene structure, a polycarbonate structure, a polyalkylene structure, a polyalkyleneoxy structure, a polysiloxane structure, a poly(meth)acrylate structure, a polyisoprene structure, a polyisobutylene structure, and a polystyrene structure in the molecule is preferable. The term "(meth)acrylate" includes acrylate and methacrylate and combinations thereof. These structures may be included in the main chain or in the side chain. These structures usually have little restriction on the movement of atoms due to the atomic bonds contained in the structure and a wide range of possible changes in bond angles and rotations, so they can function as a flexible molecular backbone. Therefore, the (D) low-elasticity polymer can be easily obtained as a resin containing these structures. Among them, a resin containing one or more selected from the group consisting of a polybutadiene structure, a polycarbonate structure, and a polyalkylene structure is more preferable.

[0090] A resin containing a polybutadiene structure may be referred to as a "polybutadiene resin". The polybutadiene structure may be partially or fully hydrogenated. Examples of the polybutadiene resin include a hydrogenated polybutadiene skeleton-containing resin, a hydroxy group-containing polybutadiene resin, a phenolic hydroxyl group-containing polybutadiene resin, a carboxy group-containing polybutadiene resin, an acid anhydride group-containing polybutadiene resin, an epoxy group-containing polybutadiene resin, an isocyanate group-containing polybutadiene resin, a urethane group-containing polybutadiene resin, a polyphenylene ether-polybutadiene resin, and the like.

[0091] Specific examples of the polybutadiene resin include "Ricon 130MA8", "Ricon 130MA13", "Ricon 130MA20", "Ricon 131MA5", "Ricon 131MA10", "Ricon 131MA17", "Ricon 131MA20", "Ricon 184MA6" (acid anhydride group-containing polybutadiene) manufactured by Cray Valley; "GQ-1000" (polybutadiene with hydroxyl group and carboxyl group introduced), "G-1000", "G-2000", "G-3000" (polybutadiene with hydroxyl groups at both ends), "GI-1000", "GI-2000", "GI-3000" (hydrogenated polybutadiene with hydroxyl groups at both ends) manufactured by Nippon Soda Co., Ltd.; "FCA-061L" (hydrogenated polybutadiene skeleton epoxy resin) manufactured by Nagase ChemteX Corporation, and the like.

[0092] In addition, specific examples of the polybutadiene resin include polyimide resins having a polybutadiene structure, a urethane structure, and an imide structure in the molecule. The polyimide resin can be produced as a linear polyimide resin (the polyimide described in JP-A-2006-37083 and International Publication No. 2008 / 153208) using hydroxyl group-terminated polybutadiene, a diisocyanate compound, and a tetracarboxylic dianhydride as raw materials. The content of the butadiene structure in the polyimide resin is preferably 60% by mass to 95% by mass, more preferably 75% by mass to 85% by mass. Details of the polyimide resin can be referred to the descriptions in JP-A-2006-37083 and International Publication No. 2008 / 153208, and this content is incorporated herein.

[0093] A resin containing a polycarbonate structure may be referred to as a "polycarbonate resin". Examples of the polycarbonate resin include a hydroxyl group-containing carbonate resin, a phenolic hydroxyl group-containing carbonate resin, a carboxyl group-containing carbonate resin, an acid anhydride group-containing carbonate resin, an isocyanate group-containing carbonate resin, a urethane group-containing carbonate resin, and the like.

[0094] Specific examples of the polycarbonate resin include "FPC0220" manufactured by Mitsubishi Gas Chemical Company; "T6002" and "T6001" (polycarbonate diol) manufactured by Asahi Kasei Corporation; "C-1090", "C-2090", and "C-3090" (polycarbonate diol) manufactured by Kuraray Co., Ltd., and the like.

[0095] In addition, specific examples of the polycarbonate resin include polyimide resins having an imide structure, a urethane structure, and a polycarbonate structure in the molecule. The polyimide resin can be produced as a linear polyimide resin using a hydroxyl group-terminated polycarbonate, a diisocyanate compound, and a tetracarboxylic dianhydride as raw materials. The content of the carbonate structure in the polyimide resin is preferably 60% by mass to 95% by mass, more preferably 75% by mass to 85% by mass. Details of the polyimide resin can be referred to the description in International Publication No. 2016 / 129541, and this content is incorporated herein.

[0096] A resin containing a polyalkylene structure may be referred to as a "polyalkylene resin". As the polyalkylene resin, a resin containing an alkylene chain in the repeating unit can be used. The number of carbon atoms in the alkylene chain is preferably 2 or more, more preferably 3 or more, still more preferably 5 or more, and even more preferably 7 or more. The upper limit may be, for example, 36 or less, 15 or less, 10 or less, 8 or less, and the like. As this polyalkylene resin, a resin containing a carbon skeleton derived from dimer acid in the repeating unit is preferred.

[0097] The carbon skeleton derived from dimer acid represents the skeleton of a divalent group excluding the two terminal carboxy groups (-COOH) of dimer acid. Dimer acid is a known compound obtained by dimerizing unsaturated fatty acids (preferably those having 11 to 22 carbon atoms, more preferably those having 18 carbon atoms), and its industrial manufacturing process is almost standardized in the industry. Dimer acid is easily available, especially those mainly composed of dimer acid having 36 carbon atoms obtained by dimerizing unsaturated fatty acids having 18 carbon atoms such as oleic acid and linoleic acid, which are inexpensive and easily available. Further, dimer acid may contain any amount of monomer acid, trimer acid, other polymerized fatty acids, etc., depending on the manufacturing method and the degree of purification. Further, although double bonds remain after the polymerization reaction of unsaturated fatty acids, in this specification, hydrogenated products obtained by further hydrogenation reaction to reduce the degree of unsaturation are also included in dimer acid.

[0098] The polyalkylene resin containing the carbon skeleton derived from dimer acid generally contains a divalent hydrocarbon group, and this divalent hydrocarbon group contains the carbon skeleton derived from dimer acid. This divalent hydrocarbon group containing the carbon skeleton derived from dimer acid usually has a long aliphatic carbon chain having 7 or more carbon atoms, and an alkylene chain is included in this long aliphatic carbon chain. The number of carbon atoms of the above-mentioned divalent hydrocarbon group containing the carbon skeleton derived from dimer acid may be 36.

[0099] Specific examples of the polyalkylene resin containing a carbon skeleton derived from dimer acid include polyimide resins containing a carbon skeleton derived from dimer acid. Examples of such polyimide resins include resins obtained by an imidization reaction of a dimer acid type diamine and a tetracarboxylic dianhydride. The dimer acid type diamine means a diamine compound having a structure in which two terminal carboxy groups (-COOH) of dimer acid are substituted with an aminomethyl group (-CH2-NH2) or an amino group (-NH2). Examples of the dimer acid type diamine include "PRIAMINE1073", "PRIAMINE1074", "PRIAMINE1075" manufactured by Croda Japan; "Versamine 551", "Versamine 552" manufactured by Cognis Japan, and the like. Further, as the tetracarboxylic dianhydride, an aliphatic tetracarboxylic dianhydride may be used, an aromatic tetracarboxylic dianhydride may be used, or a combination thereof may be used.

[0100] A resin containing a polyalkyleneoxy structure may be referred to as a "polyalkyleneoxy resin". The number of carbon atoms of the alkyleneoxy structure contained in the polyalkyleneoxy resin is preferably 2 to 15, more preferably 3 to 10, and still more preferably 5 to 8. Specific examples of the alkyleneoxy resin include "EXA-4850-150", "EXA-4816", "EXA-4822" manufactured by DIC; "EP-4000", "EP-4003", "EP-4010", "EP-4011" manufactured by ADEKA; "BEO-60E", "BPO-20E" manufactured by Shin Nippon Rika; "YL7175", "YL7410" manufactured by Mitsubishi Chemical, and the like.

[0101] A resin containing a polysiloxane structure may be referred to as a "polysiloxane resin". Examples of the polysiloxane resin include "SMP-2006", "SMP-2003PGMEA", "SMP-5005PGMEA" manufactured by Shin-Etsu Silicone; linear polyimides using an amino group-terminated polysiloxane and a tetrabasic acid anhydride as raw materials (International Publication No. 2010 / 053185, Japanese Patent Application Laid-Open No. 2002-12667, Japanese Patent Application Laid-Open No. 2000-319386, etc.), and the like.

[0102] A resin containing a poly(meth)acrylate structure may be referred to as a "poly(meth)acrylate resin". Examples of poly(meth)acrylic resins include, for example, Taisan Resin manufactured by Nagase ChemteX Corporation; "ME-2000", "W-116.3", "W-197C", "KG-25", "KG-3000" manufactured by Negami Kogyo Co., Ltd.; "ARUFON UH-2000" manufactured by Toagosei Co., Ltd., etc.

[0103] A resin containing a polyisoprene structure may be referred to as a "polyisoprene resin". Specific examples of polyisoprene resins include "KL-610", "KL613", etc. manufactured by Kuraray Co., Ltd.

[0104] A resin containing a polyisobutylene structure may be referred to as a "polyisobutylene resin". Specific examples of polyisobutylene resins include "SIBSTAR-073T" (styrene-isobutylene-styrene triblock copolymer), "SIBSTAR-042D" (styrene-isobutylene diblock copolymer), etc. manufactured by Kaneka Corporation.

[0105] A resin containing a polystyrene structure may be referred to as a "polystyrene resin". The polystyrene resin may be a copolymer containing, in combination with styrene units, any repeating units different from the above-mentioned styrene units, or may be a hydrogenated polystyrene resin. Examples of polystyrene resins include, for example, styrene-butadiene-styrene block copolymer (SBS), styrene-isoprene-styrene block copolymer (SIS), styrene-ethylene-butylene-styrene block copolymer (SEBS), styrene-ethylene-propylene-styrene block copolymer (SEPS), styrene-ethylene-ethylene-propylene-styrene block copolymer (SEEPS), styrene-butadiene-butylene-styrene block copolymer (SBBS), styrene-butadiene diblock copolymer, hydrogenated styrene-butadiene block copolymer, hydrogenated styrene-isoprene block copolymer, hydrogenated styrene-butadiene random copolymer, styrene-maleic anhydride copolymer, etc.

[0106] Specific examples of the polystyrene resin include hydrogenated styrene-based thermoplastic elastomers "H1041", "Taftec H1043", "Taftec P2000", "Taftec MP10" (manufactured by Asahi Kasei Corporation); epoxidized styrene-butadiene thermoplastic elastomers "Epofrend AT501", "CT310" (manufactured by Daicel Corporation); modified styrene-based elastomers having a hydroxyl group "Septon HG252" (manufactured by Kuraray Co., Ltd.); modified styrene-based elastomers having a carboxyl group "Taftec N503M", modified styrene-based elastomers having an amino group "Taftec N501", modified styrene-based elastomers having an acid anhydride group "Taftec M1913" (manufactured by Asahi Kasei Corporation); unmodified styrene-based elastomers "Septon S8104" (manufactured by Kuraray Co., Ltd.); styrene-ethylene / butylene-styrene block copolymers "FG1924" (manufactured by Kraton Corporation), "EF-40" (manufactured by CRAY VALLEY).

[0107] (D) The low elastic polymer preferably has a glass transition temperature Tg of 25°C or lower, or is liquid at 25°C or lower. When the (D) low elastic polymer has a glass transition temperature Tg of 25°C or lower, the glass transition temperature Tg is preferably 20°C or lower, more preferably 15°C or lower. The lower limit of the glass transition temperature Tg is not particularly limited, but may preferably be -15°C or higher. When the (D) low elastic polymer is liquid at 25°C or lower, the (D) low elastic polymer is preferably liquid at 25°C, more preferably liquid at 20°C, and still more preferably liquid at 15°C. The glass transition temperature Tg can be measured by DSC (differential scanning calorimetry) at a heating rate of 5°C / min.

[0108] (D) The low-elasticity polymer may have a functional group capable of reacting with an epoxy resin such as (A) a first epoxy resin and (B) a second epoxy resin. When (D) the low-elasticity polymer can react with the epoxy resin, the mechanical strength of the cured product of the resin composition can be enhanced. The functional groups capable of reacting with the epoxy resin include those that appear upon heating. Examples of such functional groups include a hydroxyl group, a carboxy group, an acid anhydride group, a phenolic hydroxyl group, an epoxy group, an isocyanate group, a urethane group, and a maleimide group (2,5-dihydro-2,5-dioxo-1H-pyrrol-1-yl group). Among them, a hydroxyl group, an acid anhydride group, a phenolic hydroxyl group, an epoxy group, an isocyanate group, a urethane group, and a maleimide group are preferred, and a phenolic hydroxyl group is more preferred.

[0109] (D) The amount of the low-elasticity polymer preferably is 0.1% by mass or more, more preferably 0.5% by mass or more, still more preferably 1% by mass or more, and preferably 30% by mass or less, more preferably 20% by mass or less, particularly preferably 10% by mass or less, based on 100% by mass of the nonvolatile components in the resin composition. When the amount of (D) the low-elasticity polymer is within the above range, reduction of the dielectric tangent, suppression of warpage, and improvement of adhesion can be effectively achieved, and usually, the minimum melt viscosity of the resin composition can also be effectively reduced.

[0110] (D) The amount of the low-elasticity polymer preferably is 1% by mass or more, more preferably 2% by mass or more, particularly preferably 5% by mass or more, and preferably 50% by mass or less, more preferably 40% by mass or less, particularly preferably 30% by mass or less, based on 100% by mass of the resin components in the resin composition. When the amount of (D) the low-elasticity polymer is within the above range, reduction of the dielectric tangent, suppression of warpage, and improvement of adhesion can be effectively achieved, and usually, the minimum melt viscosity of the resin composition can also be effectively reduced.

[0111] <(E) Inorganic filler> The resin composition according to this embodiment contains an (E) inorganic filler as the (E) component. The (E) inorganic filler is particles of an inorganic material. Therefore, the (E) inorganic filler is contained in the resin composition in a particulate state and is usually contained in the cured product while maintaining the particulate state. The (E) inorganic filler does not include those corresponding to the above-mentioned (A) to (D) components.

[0112] (E) Usually, an inorganic compound is used as the inorganic material forming the inorganic filler. Examples of the material of the (E) inorganic filler include silica, alumina, glass, cordierite, silicon oxide, barium sulfate, barium carbonate, talc, clay, mica powder, zinc oxide, hydrotalcite, boehmite, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, magnesium oxide, boron nitride, aluminum nitride, manganese nitride, aluminum borate, strontium carbonate, strontium titanate, calcium titanate, magnesium titanate, bismuth titanate, titanium oxide, zirconium oxide, barium titanate, barium zirconate titanate, barium zirconate, calcium zirconate, zirconium phosphate, and zirconium tungstate phosphate. Among these, silica and alumina are preferred, and silica is particularly preferred. Therefore, the (E) inorganic filler preferably contains silica and may contain only silica. Examples of silica include amorphous silica, fused silica, crystalline silica, synthetic silica, and hollow silica. Also, spherical silica is preferred as the silica. The (E) inorganic filler may be used alone or in combination of two or more.

[0113] (E) Examples of commercially available inorganic fillers include "SP60-05", "SP507-05" manufactured by Nippon Steel Chemical & Material Co., Ltd.; "YC100C", "YA050C", "YA050C-MJE", "YA010C", "SC2500SQ", "SO-C4", "SO-C2", "SO-C1" manufactured by Admatechs Co., Ltd.; "UFP-30", "DAW-03", "FB-105FD" manufactured by Denka Co., Ltd.; "Silfill NSS-3N", "Silfill NSS-4N", "Silfill NSS-5N" manufactured by Tokuyama Corporation; "Celsfiers", "MGH-005" manufactured by Taiheiyo Cement Corporation; "Esferic", "BA-1" manufactured by JGC Catalysts & Chemicals Ltd., and the like.

[0114] (E) The average particle size of the inorganic filler is preferably 0.01 μm or more, more preferably 0.05 μm or more, still more preferably 0.1 μm or more, and preferably 10 μm or less, more preferably 5 μm or less, still more preferably 3 μm or less, and even more preferably 1 μm or less.

[0115] (E) The average particle size of the inorganic filler can be measured by a laser diffraction / scattering method based on the Mie scattering theory. Specifically, it can be measured by creating a volume-based particle size distribution of the inorganic filler using a laser diffraction / scattering type particle size distribution measuring device and taking the median diameter thereof as the average particle size. As the measurement sample, 100 mg of the inorganic filler and 10 g of methyl ethyl ketone can be weighed into a vial and dispersed by ultrasonic waves for 10 minutes. The measurement sample can be used to measure the volume-based particle size distribution of the inorganic filler using a laser diffraction type particle size distribution measuring device with the wavelengths of the light sources used being blue and red and in a flow cell method, and the average particle size can be calculated as the median diameter from the obtained particle size distribution. Examples of the laser diffraction type particle size distribution measuring device include "LA-960" manufactured by Horiba, Ltd.

[0116] (E) The specific surface area of the inorganic filler is preferably 0.1 m 2 / g or more, more preferably 0.5 m 2 / g or more, still more preferably 1 m 2 / g or more, particularly preferably 3 m 2 / g or more, preferably 100 m 2 / g or less, more preferably 70 m 2 / g or less, even more preferably 50 m 2 / g or less, particularly preferably 40 m 2 / g or less. (E) The specific surface area of the inorganic filler can be measured by adsorbing nitrogen gas on the sample surface using a specific surface area measuring device (Macsorb HM-1210 manufactured by Mountech Co., Ltd.) in accordance with the BET method and calculating the specific surface area using the BET multi-point method.

[0117] (E) From the viewpoint of enhancing moisture resistance and dispersibility, the inorganic filler is preferably treated with a surface treatment agent. Examples of the surface treatment agent include fluorine-containing silane coupling agents, aminosilane-based coupling agents, epoxysilane-based coupling agents, mercaptosilane-based coupling agents, silane-based coupling agents, alkoxysilanes, organosilazane compounds, titanate-based coupling agents, and the like. The surface treatment agent may be used alone or in any combination of two or more.

[0118] Examples of commercially available surface treatment agents include "KBM403" (3-glycidoxypropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., "KBM803" (3-mercaptopropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., "KBE903" (3-aminopropyltriethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., "KBM573" (N-phenyl-3-aminopropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., "SZ-31" (hexamethyldisilazane) manufactured by Shin-Etsu Chemical Co., Ltd., "KBM103" (phenyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., "KBM-4803" (long-chain epoxy type silane coupling agent) manufactured by Shin-Etsu Chemical Co., Ltd., "KBM-7103" (3,3,3-trifluoropropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., and the like.

[0119] From the perspective of improving the dispersibility of the inorganic filler, the degree of surface treatment with the surface treatment agent preferably falls within a specific range. Specifically, it is preferable that 100% by mass of the inorganic filler is surface-treated with 0.2% to 5% by mass of the surface treatment agent, more preferably surface-treated with 0.2% to 3% by mass of the surface treatment agent, and even more preferably surface-treated with 0.3% to 2% by mass of the surface treatment agent.

[0120] The degree of surface treatment with the surface treatment agent can be evaluated by the amount of carbon per unit surface area of the inorganic filler. From the perspective of improving the dispersibility of the inorganic filler, the amount of carbon per unit surface area of the inorganic filler is preferably 0.02 mg / m 2 or more, more preferably 0.1 mg / m 2 or more, and even more preferably 0.2 mg / m 2 or more. On the other hand, from the perspective of preventing an increase in the melt viscosity of the resin composition layer, it is preferably 1.0 mg / m 2 or less, more preferably 0.8 mg / m 2 or less, and even more preferably 0.5 mg / m 2 or less.

[0121] (E) The amount of carbon per unit surface area of the inorganic filler can be measured after washing the surface-treated inorganic filler with a solvent (for example, methyl ethyl ketone (MEK)). Specifically, a sufficient amount of MEK as a solvent is added to the inorganic filler surface-treated with the surface treatment agent, and ultrasonic cleaning is performed at 25°C for 5 minutes. After removing the supernatant and drying the solid content, the amount of carbon per unit surface area of the inorganic filler can be measured using a carbon analyzer. As the carbon analyzer, "EMIA-320V" manufactured by Horiba, Ltd. etc. can be used.

[0122] (E) The range of the amount of the inorganic filler is preferably 50% by mass or more, more preferably 60% by mass or more, still more preferably 70% by mass or more, and preferably 90% by mass or less, more preferably 85% by mass or less, still more preferably 80% by mass or less, based on 100% by mass of the non-volatile components in the resin composition. When the amount of the (E) inorganic filler is within the above range, reduction of the dielectric tangent, suppression of warpage, and improvement of adhesion can be effectively achieved. Also, generally, a resin composition containing a large amount of the (E) inorganic filler tends to have a high melt viscosity, but in the resin composition according to this embodiment, the minimum melt viscosity can usually be lowered.

[0123] (A) The total amount of the first epoxy resin, (B) the second epoxy resin, (C) the curing agent, (D) the low-elastic polymer, and (E) the inorganic filler ranges from preferably 70% by mass or more, more preferably 80% by mass or more, still more preferably 90% by mass or more, based on 100% by mass of the non-volatile components in the resin composition. The upper limit is usually 100% by mass or less, but may be 99.9% by mass or less.

[0124] <(F) Polymerizable unsaturated resin> The resin composition according to this embodiment may contain, as an optional component, (F) a polymerizable unsaturated resin. The (F) polymerizable unsaturated resin as the (F) component does not include those corresponding to the above-described (A) to (E) components. The (F) polymerizable unsaturated resin may be used alone or in combination of two or more.

[0125] (F) As the polymerizable unsaturated resin, a resin containing a non-aromatic carbon-carbon unsaturated bond can be used. Therefore, the (F) polymerizable unsaturated resin usually may have a polymerizable unsaturated group containing a non-aromatic carbon-carbon unsaturated bond. Examples of the polymerizable unsaturated group include unsaturated hydrocarbon groups such as vinyl group, allyl group, 1-propenyl group, 3-cyclohexenyl group, 3-cyclopentenyl group, 2-vinylphenyl group, 3-vinylphenyl group, 4-vinylphenyl group; α,β-unsaturated carbonyl groups such as acryloyl group, methacryloyl group, maleimide group, and the like. The (F) polymerizable unsaturated resin having these polymerizable unsaturated groups can usually react by radical polymerization. The (F) polymerizable unsaturated resin preferably has two or more polymerizable unsaturated groups.

[0126] (F) Examples of the polymerizable unsaturated resin include (meth)acrylic polymerizable unsaturated resin, styrene polymerizable unsaturated resin, allyl polymerizable unsaturated resin, maleimide polymerizable unsaturated resin, and the like.

[0127] As the (meth)acrylic polymerizable unsaturated resin, a resin having one or more, preferably two or more acryloyl groups and / or methacryloyl groups in one molecule can be used. Examples of the (meth)acrylic polymerizable unsaturated resin include low molecular weight (molecular weight less than 1000) aliphatic (meth)acrylate resins such as cyclohexane-1,4-dimethanol di(meth)acrylate, cyclohexane-1,3-dimethanol di(meth)acrylate, tricyclodecane dimethanol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,8-octanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethylolethane tri(meth)acrylate, glycerin tri(meth)acrylate, pentaerythritol tetra(meth)acrylate; low molecular weight (molecular weight less than 1000) ether-containing (meth)acrylate resins such as dioxane glycol di(meth)acrylate, 3,6-dioxa-1,8-octanediol di(meth)acrylate, 3,6,9-trioxaundecane-1,11-diol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, 9,9-bis[4-(2-acryloyloxyethoxy)phenyl]fluorene, ethoxylated bisphenol A di(meth)acrylate, propoxylated bisphenol A di(meth)acrylate; low molecular weight (molecular weight less than 1000) isocyanurate-containing (meth)acrylate resins such as tris(3-hydroxypropyl)isocyanurate tri(meth)acrylate, tris(2-hydroxyethyl)isocyanurate tri(meth)acrylate, ethoxylated isocyanuric acid tri(meth)acrylate; high molecular weight (molecular weight 1000 or more) (meth)acrylate resins such as (meth)acrylic-modified polyphenylene ether resin. The term "(meth)acrylic acid" includes acrylic acid, methacrylic acid and combinations thereof.Examples of commercially available (meth)acrylic polymerizable unsaturated resins include "A-DOG" (dioxane glycol diacrylate) manufactured by Shin-Nakamura Chemical Co., Ltd., "DCP-A" (tricyclodecane dimethanol diacrylate), "DCP" (tricyclodecane dimethanol dimethacrylate), "BPE-1300N" (ethoxylated bisphenol A dimethacrylate) manufactured by Kyoeisha Chemical Co., Ltd., "KAYARAD R-684" (tricyclodecane dimethanol diacrylate), "KAYARAD R-604" (dioxane glycol diacrylate) manufactured by Nippon Kayaku Co., Ltd., "SA9000", "SA9000-111" (methacrylic modified polyphenylene ether) manufactured by SABIC, and the like.

[0128] As the styrene-based polymerizable unsaturated resin, a resin having one or more, preferably two or more vinyl groups directly bonded to aromatic carbon atoms in one molecule can be used. Examples of the styrene-based polymerizable unsaturated resin include low molecular weight (molecular weight less than 1000) styrene-based resins such as divinylbenzene, 2,4-divinyltoluene, 2,6-divinylnaphthalene, 1,4-divinylnaphthalene, 4,4'-divinylbiphenyl, 1,2-bis(4-vinylphenyl)ethane, 2,2-bis(4-vinylphenyl)propane, and bis(4-vinylphenyl) ether; high molecular weight (molecular weight 1000 or more) styrene-based resins such as vinylbenzyl-modified polyphenylene ether resin and styrene-divinylbenzene copolymer; and the like. Examples of commercially available styrene-based polymerizable unsaturated resins include "ODV-XET(X03)", "ODV-XET(X04)", "ODV-XET(X05)" (styrene-divinylbenzene copolymer) manufactured by Nippon Steel Chemical & Material Co., Ltd., and "OPE-2St 1200", "OPE-2St 2200" (vinylbenzyl-modified polyphenylene ether resin) manufactured by Mitsubishi Gas Chemical Company, Inc.

[0129] As the allyl-based polymerizable unsaturated resin, a resin having one or more, preferably two or more allyl groups in one molecule can be used. Examples of the allyl-based polymerizable unsaturated resin include aromatic carboxylic acid allyl ester resins such as diallyl diphenate, triallyl trimellitate, diallyl phthalate, diallyl isophthalate, diallyl terephthalate, diallyl 2,6-naphthalenedicarboxylate, and diallyl 2,3-naphthalenedicarboxylate; allyl ester resins of isocyanuric acid such as 1,3,5-triallyl isocyanurate and 1,3-diallyl-5-glycidyl isocyanurate; epoxy-containing aromatic allyl resins such as 2,2-bis[3-allyl-4-(glycidyloxy)phenyl]propane; benzoxazine-containing aromatic allyl resins such as bis[3-allyl-4-(3,4-dihydro-2H-1,3-benzoxazin-3-yl)phenyl]methane; ether-containing aromatic allyl resins such as 1,3,5-triallyl ether benzene; and allyl silane resins such as diallyl diphenylsilane. Commercially available products of the allyl-based polymerizable unsaturated resin include, for example, "TAIC" (1,3,5-triallyl isocyanurate) manufactured by Nippon Kasei Co., Ltd., "DAD" (diallyl diphenate) manufactured by Nisshoku Techno Fine Chemical Co., Ltd., "TRIAM-705" (triallyl trimellitate) manufactured by Fujifilm Wako Pure Chemical Corporation, the product name "DAND" (diallyl 2,3-naphthalenedicarboxylate) manufactured by Nisshoku Techno Fine Chemical Co., Ltd., "ALP-d" (bis[3-allyl-4-(3,4-dihydro-2H-1,3-benzoxazin-3-yl)phenyl]methane) manufactured by Shikoku Kasei Kogyo Co., Ltd., "RE-810NM" (2,2-bis[3-allyl-4-(glycidyloxy)phenyl]propane) manufactured by Nippon Kayaku Co., Ltd., "DA-MGIC" (1,3-diallyl-5-glycidyl isocyanurate) manufactured by Shikoku Kasei Kogyo Co., Ltd., "NE-V-1100-70T" manufactured by DIC Corporation, and the like.

[0130] As the maleimide-based polymerizable unsaturated resin, a resin having one or more, preferably two or more maleimide groups in one molecule can be used. The maleimide-based polymerizable unsaturated resin may be an aromatic maleimide resin having a maleimide group directly bonded to an aromatic ring, or may be an aliphatic maleimide resin having no maleimide group directly bonded to an aromatic ring. Examples of commercially available maleimide-based radical polymerizable resins include aliphatic maleimide resins containing an aliphatic skeleton (preferably an aliphatic skeleton derived from a dimer acid type diamine) such as "SLK-1500" (manufactured by Shin-Etsu Chemical Co., Ltd.), "SLK-2600" (manufactured by Shin-Etsu Chemical Co., Ltd.), "SLK-6895-T90" (manufactured by Shin-Etsu Chemical Co., Ltd.), "BMI-1500" (manufactured by Designer Molecules Inc.), "BMI-1700" (manufactured by Designer Molecules Inc.), "BMI-3000J" (manufactured by Designer Molecules Inc.), "BMI-689" (manufactured by Designer Molecules Inc.), "BMI-2500" (manufactured by Designer Molecules Inc.); aromatic maleimide resins such as "MIR-3000-70MT" (manufactured by Nippon Kayaku Co., Ltd.), "BMI-4000" (manufactured by Daiwa Kasei Co., Ltd.), "BMI-80" (manufactured by KI Chemical Industry Co., Ltd.), "BMI-6100" (manufactured by Designer Molecules Inc.). Further, as the maleimide-based polymerizable unsaturated resin, a maleimide resin (indan ring skeleton-containing maleimide compound) disclosed in Invention Association Public Technical Report Publication No. 2020-500211 may be used.

[0131] (F) The polymerizable unsaturated group equivalent of the polymerizable unsaturated resin is preferably 20 g / eq. to 3,000 g / eq., more preferably 50 g / eq. to 2,500 g / eq., still more preferably 70 g / eq. to 2,000 g / eq., and particularly preferably 90 g / eq. to 1,500 g / eq. The polymerizable unsaturated group equivalent represents the mass of the resin per equivalent of the polymerizable unsaturated group.

[0132] (F) The weight average molecular weight (Mw) of the polymerizable unsaturated resin is preferably 40,000 or less, more preferably 10,000 or less, still more preferably 5,000 or less, and particularly preferably 3,000 or less. The lower limit is not particularly limited and can be, for example, 150 or more.

[0133] (F) The range of the amount of the polymerizable unsaturated resin is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, still more preferably 1% by mass or more, and preferably 30% by mass or less, more preferably 20% by mass or less, still more preferably 10% by mass or less, based on 100% by mass of the non-volatile components in the resin composition.

[0134] (F) The range of the amount of the polymerizable unsaturated resin is preferably 1% by mass or more, more preferably 2% by mass or more, particularly preferably 5% by mass or more, and preferably 50% by mass or less, more preferably 40% by mass or less, still more preferably 30% by mass or less, based on 100% by mass of the resin components in the resin composition.

[0135] <(G) Organic filler> The resin composition according to the present embodiment may contain, as an optional component, (G) an organic filler. The (G) organic filler as the component (G) does not include those corresponding to the above-described components (A) to (F). The (G) organic filler is usually not compatible with the resin components other than the (G) organic filler and is contained in the resin composition in a particulate state, and is contained in the cured product while maintaining the particulate state. Also, the (G) organic filler may be used alone or in combination of two or more.

[0136] (G) As the organic filler, particles of an organic material can be used. As the organic material contained in the organic filler, a rubber component is preferred. Examples of the rubber component include silicone-based elastomers such as polydimethylsiloxane; olefin-based thermoplastic elastomers such as polybutadiene, polyisoprene, polychlorobutadiene, ethylene-vinyl acetate copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-isobutylene copolymer, acrylonitrile-butadiene copolymer, isoprene-isobutylene copolymer, isobutylene-butadiene copolymer, ethylene-propylene-diene terpolymer, and ethylene-propylene-butene terpolymer; and thermoplastic elastomers such as acrylic-based thermoplastic elastomers like poly(propyl (meth)acrylate), poly(butyl (meth)acrylate), poly(cyclohexyl (meth)acrylate), and poly(octyl (meth)acrylate). Furthermore, a silicone-based rubber such as polyorganosiloxane rubber may be mixed with the rubber component. The rubber component contained in the rubber particles has a glass transition temperature of, for example, 0°C or lower, preferably -10°C or lower, more preferably -20°C or lower, and even more preferably -30°C or lower.

[0137] (G) The organic filler may be core-shell type rubber particles composed of core particles containing the rubber component listed above and a shell portion obtained by graft copolymerizing a monomer component copolymerizable with the rubber component contained in the core particles. Here, the core-shell type does not necessarily refer only to those in which the core particles and the shell portion can be clearly distinguished, but also includes those in which the boundary between the core particles and the shell portion is unclear, and the core particles do not have to be completely covered by the shell portion.

[0138] (G) Specific examples of the organic filler include, for example, "CHT" manufactured by Samsung SDI Co., Ltd.; "B602" manufactured by Techno UMG Co., Ltd.; "Paraloid EXL-2602", "Paraloid EXL-2603", "Paraloid EXL-2655", "Paraloid EXL-2311", "Paraloid-EXL2313", "Paraloid EXL-2315", "Paraloid KM-330", "Paraloid KM-336P", "Paraloid KCZ-201" manufactured by The Dow Chemical Company; "Metablen C-223A", "Metablen E-901", "Metablen S-2001", "Metablen W-450A", "Metablen SRK-200" manufactured by Mitsubishi Rayon Co., Ltd.; "Kaneka Ace M-511", "Kaneka Ace M-600", "Kaneka Ace M-400", "Kaneka Ace M-580", "Kaneka Ace MR-01" manufactured by Kaneka Corporation; "Staffiroid AC3355", "Staffiroid AC3816", "Staffiroid AC3816N", "Staffiroid AC3832", "Staffiroid AC4030", "Staffiroid AC3364" manufactured by Aika Industries Co., Ltd., and the like.

[0139] (G) The range of the amount of the organic filler is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, still more preferably 0.5% by mass or more, and preferably 10% by mass or less, more preferably 5% by mass or less, still more preferably 1% by mass or less, based on 100% by mass of the non-volatile components in the resin composition.

[0140] (G) The range of the amount of the organic filler is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, still more preferably 1% by mass or more, and preferably 20% by mass or less, more preferably 10% by mass or less, still more preferably 5% by mass or less, based on 100% by mass of the resin components in the resin composition.

[0141] <(H) Curing accelerator> The resin composition according to this embodiment may contain, as an optional component, (H) a curing accelerator. The (H) curing accelerator as the component (H) does not include those corresponding to the above-described components (A) to (G). The (H) curing accelerator can act as a catalyst for the reaction of epoxy resins such as (A) the first epoxy resin and (B) the second epoxy resin to accelerate the curing of the resin composition.

[0142] Examples of the (H) curing accelerator include a phosphorus-based curing accelerator, a urea-based curing accelerator, a guanidine-based curing accelerator, an imidazole-based curing accelerator, a metal-based curing accelerator, an amine-based curing accelerator, and the like. The (H) curing accelerator may be used alone or in combination of two or more.

[0143] Examples of phosphorus-based curing accelerators include aliphatic phosphonium salts such as tetrabutylphosphonium bromide, tetrabutylphosphonium chloride, tetrabutylphosphonium acetate, tetrabutylphosphonium decanoate, tetrabutylphosphonium laurate, bis(tetrabutylphosphonium) pyromellitate, tetrabutylphosphonium hydrogen hexahydrophthalate, tetrabutylphosphonium 2,6-bis[(2-hydroxy-5-methylphenyl)methyl]-4-methylphenolate, di-tert-butyldimethylphosphonium tetraphenylborate; aromatic phosphonium salts such as methyltriphenylphosphonium bromide, ethyltriphenylphosphonium bromide, propyltriphenylphosphonium bromide, butyltriphenylphosphonium bromide, benzyltriphenylphosphonium chloride, tetraphenylphosphonium bromide, p-tolyltriphenylphosphonium tetra-p-tolylborate, tetraphenylphosphonium tetraphenylborate, tetraphenylphosphonium tetra-p-tolylborate, triphenylethylphosphonium tetraphenylborate, tris(3-methylphenyl)ethylphosphonium tetraphenylborate, tris(2-methoxyphenyl)ethylphosphonium tetraphenylborate, (4-methylphenyl)triphenylphosphonium thiocyanate, tetraphenylphosphonium thiocyanate, butyltriphenylphosphonium thiocyanate; aromatic phosphine-borane complexes such as triphenylphosphine·triphenylborane; aromatic phosphine-quinone addition reactants such as triphenylphosphine·p-benzoquinone addition reactant; aliphatic phosphines such as tributylphosphine, tri-tert-butylphosphine, trioctylphosphine, di-tert-butyl(2-butenyl)phosphine, di-tert-butyl(3-methyl-2-butenyl)phosphine, tricyclohexylphosphine;Aromatic phosphines such as dibutylphenylphosphine, di-tert-butylphenylphosphine, methyldiphenylphosphine, ethyldiphenylphosphine, butyldiphenylphosphine, diphenylcyclohexylphosphine, triphenylphosphine, tri-o-tolylphosphine, tri-m-tolylphosphine, tri-p-tolylphosphine, tris(4-ethylphenyl)phosphine, tris(4-propylphenyl)phosphine, tris(4-isopropylphenyl)phosphine, tris(4-butylphenyl)phosphine, tris(4-tert-butylphenyl)phosphine, tris(2,4-dimethylphenyl)phosphine, tris(2,5-dimethylphenyl)phosphine, tris(2,6-dimethylphenyl)phosphine, tris(3,5-dimethylphenyl)phosphine, tris(2,4,6-trimethylphenyl)phosphine, tris(2,6-dimethyl-4-ethoxyphenyl)phosphine, tris(2-methoxyphenyl)phosphine, tris(4-methoxyphenyl)phosphine, tris(4-ethoxyphenyl)phosphine, tris(4-tert-butoxyphenyl)phosphine, diphenyl-2-pyridylphosphine, 1,2-bis(diphenylphosphino)ethane, 1,3-bis(diphenylphosphino)propane, 1,4-bis(diphenylphosphino)butane, 1,2-bis(diphenylphosphino)acetylene, 2,2'-bis(diphenylphosphino)diphenylether, etc. are mentioned.;

[0144] Examples of urea-based curing accelerators include, for example, 1,1-dimethylurea; aliphatic dimethylureas such as 1,1,3-trimethylurea, 3-ethyl-1,1-dimethylurea, 3-cyclohexyl-1,1-dimethylurea, 3-cyclooctyl-1,1-dimethylurea; aromatic dimethylureas such as 3-phenyl-1,1-dimethylurea, 3-(4-chlorophenyl)-1,1-dimethylurea, 3-(3,4-dichlorophenyl)-1,1-dimethylurea, 3-(3-chloro-4-methylphenyl)-1,1-dimethylurea, 3-(2-methylphenyl)-1,1-dimethylurea, 3-(4-methylphenyl)-1,1-dimethylurea, 3-(3,4-dimethylphenyl)-1,1-dimethylurea, 3-(4-isopropylphenyl)-1,1-dimethylurea, 3-(4-methoxyphenyl)-1,1-dimethylurea, 3-(4-nitrophenyl)-1,1-dimethylurea, 3-[4-(4-methoxyphenoxy)phenyl]-1,1-dimethylurea, 3-[4-(4-chlorophenoxy)phenyl]-1,1-dimethylurea, 3-[3-(trifluoromethyl)phenyl]-1,1-dimethylurea, N,N-(1,4-phenylene)bis(N’,N’-dimethylurea), N,N-(4-methyl-1,3-phenylene)bis(N’,N’-dimethylurea) [toluene bisdimethylurea], etc.

[0145] Examples of guanidine-based curing accelerators include, for example, dicyandiamide, 1-methylguanidine, 1-ethylguanidine, 1-cyclohexylguanidine, 1-phenylguanidine, 1-(o-tolyl)guanidine, dimethylguanidine, diphenylguanidine, trimethylguanidine, tetramethylguanidine, pentamethylguanidine, 1,5,7-triazabicyclo[4.4.0]dec-5-ene, 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene, 1-methylbiguanide, 1-ethylbiguanide, 1-n-butylbiguanide, 1-n-octadecylbiguanide, 1,1-dimethylbiguanide, 1,1-diethylbiguanide, 1-cyclohexylbiguanide, 1-allylbiguanide, 1-phenylbiguanide, 1-(o-tolyl)biguanide, etc.

[0146] Examples of imidazole-based curing accelerators include imidazole compounds such as 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazolium trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-undecylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2,3-dihydro-1H-pyrrolo[1,2-a]benzimidazole, 1-dodecyl-2-methyl-3-benzylimidazolium chloride, 2-methylimidazoline, 2-phenylimidazoline, and adducts of imidazole compounds and epoxy resins. Commercially available products of imidazole-based curing accelerators include, for example, "1B2PZ", "2E4MZ", "2MZA-PW", "2MZ-OK", "2MA-OK", "2MA-OK-PW", "2PHZ", "2PHZ-PW", "Cl1Z", "Cl1Z-CN", "Cl1Z-CNS", "C11Z-A" manufactured by Shikoku Kasei Kogyo Co., Ltd.; "P200-H50" manufactured by Mitsubishi Chemical Corporation, etc.

[0147] Examples of metal-based hardening accelerators include organometallic complexes or organometallic salts of metals such as cobalt, copper, zinc, iron, nickel, manganese, and tin. Specific examples of organometallic complexes include organocobalt complexes such as cobalt(II) acetylacetonate and cobalt(III) acetylacetonate, organocopper complexes such as copper(II) acetylacetonate, organozinc complexes such as zinc(II) acetylacetonate, organoiron complexes such as iron(III) acetylacetonate, organonickel complexes such as nickel(II) acetylacetonate, and organomanganese complexes such as manganese(II) acetylacetonate. Examples of organometallic salts include zinc octylate, tin octylate, zinc naphthenate, cobalt naphthenate, tin stearate, and zinc stearate.

[0148] Examples of amine-based hardening accelerators include trialkylamines such as triethylamine and tributylamine, 4-dimethylaminopyridine, benzyldimethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, 1,8-diazabicyclo(5,4,0)-undecene, etc. As the amine-based hardening accelerator, commercially available products may be used, for example, "MY-25" manufactured by Ajinomoto Fine-Techno Co., Inc.

[0149] (H) The amount of the hardening accelerator is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, still more preferably 0.1% by mass or more, and preferably 5% by mass or less, more preferably 2% by mass or less, still more preferably 1% by mass or less, based on 100% by mass of the non-volatile components in the resin composition.

[0150] (H) The amount of the hardening accelerator is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, still more preferably 0.5% by mass or more, and preferably 10% by mass or less, more preferably 6% by mass or less, still more preferably 3% by mass or less, based on 100% by mass of the resin components in the resin composition.

[0151] <(I) Optional Additives> The resin composition according to this embodiment may further contain, as an optional component, (I) an optional additive. The (I) optional additive as the component (I) does not include those corresponding to the above-described components (A) to (H). Examples of the (I) optional additive include organometallic compounds such as organic copper compounds, organic zinc compounds, and organic cobalt compounds; colorants such as phthalocyanine blue, phthalocyanine green, iodine green, diazo yellow, crystal violet, titanium oxide, and carbon black; polymerization inhibitors such as hydroquinone, catechol, pyrogallol, and phenothiazine; leveling agents such as silicone-based leveling agents and acrylic polymer-based leveling agents; thickeners such as benton and montmorillonite; antifoaming agents such as silicone-based antifoaming agents, acrylic-based antifoaming agents, fluorine-based antifoaming agents, and vinyl resin-based antifoaming agents; ultraviolet absorbers such as benzotriazole-based ultraviolet absorbers; adhesion improvers such as urea silane; adhesion imparting agents such as triazole-based adhesion imparting agents, tetrazole-based adhesion imparting agents, and triazine-based adhesion imparting agents; antioxidants such as hindered phenol-based antioxidants; fluorescent brighteners such as stilbene derivatives; surfactants such as fluorine-based surfactants and silicone-based surfactants; flame retardants such as phosphorus-based flame retardants (e.g., phosphate ester compounds, phosphazene compounds, phosphinic acid compounds, red phosphorus), nitrogen-based flame retardants (e.g., melamine sulfate), halogen-based flame retardants, and inorganic flame retardants (e.g., antimony trioxide); dispersants such as phosphate ester-based dispersants, polyoxyalkylene-based dispersants, acetylene-based dispersants, silicone-based dispersants, anionic dispersants, and cationic dispersants; stabilizers such as borate-based stabilizers, titanate-based stabilizers, aluminate-based stabilizers, zirconate-based stabilizers, isocyanate-based stabilizers, carboxylic acid-based stabilizers, and carboxylic anhydride-based stabilizers, etc. The (I) optional additive may be used alone or in combination of two or more.

[0152] <(J) Solvent> The resin composition according to this embodiment may further contain (J) a solvent as an optional volatile component in combination with the non-volatile components such as the above-described components (A) to (I). Usually, an organic solvent is used as the (J) solvent. Examples of the organic solvent include ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ester solvents such as methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate, isoamyl acetate, methyl propionate, ethyl propionate, and γ-butyrolactone; ether solvents such as tetrahydropyran, tetrahydrofuran, 1,4-dioxane, diethyl ether, diisopropyl ether, dibutyl ether, diphenyl ether, and anisole; alcohol solvents such as methanol, ethanol, propanol, butanol, and ethylene glycol; ether ester solvents such as 2-ethoxyethyl acetate, propylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl diglycol acetate, γ-butyrolactone, and methyl methoxypropionate; ester alcohol solvents such as methyl lactate, ethyl lactate, and methyl 2-hydroxyisobutyrate; ether alcohol solvents such as 2-methoxypropanol, 2-methoxyethanol, 2-ethoxyethanol, propylene glycol monomethyl ether, and diethylene glycol monobutyl ether (butyl carbitol); amide solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone; sulfoxide solvents such as dimethyl sulfoxide; nitrile solvents such as acetonitrile and propionitrile; aliphatic hydrocarbon solvents such as hexane, cyclopentane, cyclohexane, and methylcyclohexane; aromatic hydrocarbon solvents such as benzene, toluene, xylene, ethylbenzene, and trimethylbenzene. The (J) solvent may be used alone or in combination of two or more.

[0153] (J) The amount of the solvent may be, for example, 60% by mass or less, 40% by mass or less, 30% by mass or less, 20% by mass or less, 15% by mass or less, or 10% by mass or less, or may be 0% by mass, based on 100% by mass of all the components in the resin composition.

[0154] <Method for producing resin composition> The resin composition according to this embodiment can be produced, for example, by mixing the components that can be included in the resin composition. The above-described components may be mixed partially or entirely at the same time, or may be mixed in order. During the process of mixing each component, the temperature may be appropriately set, and thus, heating and / or cooling may be performed temporarily or throughout. Further, stirring or shaking may be performed during the process of mixing each component.

[0155] <Properties of resin composition and its cured product> The resin composition according to this embodiment can usually have a low minimum melt viscosity. Therefore, for example, when forming a resin composition layer on an inner layer substrate provided with wiring on the surface, the wiring on the surface of the inner layer substrate can be well embedded in the resin composition layer. The specific range of the minimum melt viscosity of the resin composition is preferably less than 6,000 poise, more preferably less than 5,000 poise, and still more preferably less than 4,000 poise. The lower limit can be, for example, 500 poise or more, 1,000 poise or more, etc.

[0156] The minimum melt viscosity of the resin composition can be obtained by measuring the dynamic viscoelastic modulus while raising the temperature under the measurement conditions of a starting temperature of 60°C to 200°C, a heating rate of 5°C / min, a measurement interval temperature of 2.5°C, a frequency of 1 Hz, and a strain of 5 deg using a dynamic viscoelasticity measuring device, and taking the lowest value of the measured melt viscosity as the minimum melt viscosity. As the specific measurement method, the method of <Test Example 3: Measurement test of minimum melt viscosity> in the examples described later can be adopted.

[0157] By curing the resin composition, a cured product of the resin composition can be obtained. And an insulating layer can be formed by this cured product. Usually, since heat is applied during the curing of the resin composition, among the components included in the resin composition, volatile components such as (J) a solvent may volatilize due to the heat during curing. Therefore, the cured product obtained by curing the resin composition may contain non-volatile components such as components (A) to (I) or reaction products thereof.

[0158] The cured product of the resin composition according to this embodiment can have excellent dielectric properties. Specifically, it can have a low dielectric tangent Df. In one example, the dielectric tangent Df of the cured product is preferably 0.0040 or less, more preferably 0.0038 or less, and still more preferably 0.0036 or less. The lower limit of the dielectric tangent Df is not particularly limited and can be, for example, 0.0010 or more.

[0159] The dielectric tangent Df of the cured product of the resin composition can be measured by the cavity resonance perturbation method under the measurement conditions of a measurement frequency of 5.8 GHz and a measurement temperature of 23°C. When the sample is the resin composition before curing, the resin composition can be cured under the curing conditions of 200°C for 90 minutes to obtain a cured product, and the dielectric tangent Df of the cured product can be measured. As a specific measurement method, the method of <Test Example 1: Measurement Test of Dielectric Tangent Df> in the examples described later can be adopted.

[0160] When the cured product of the resin composition according to this embodiment is provided on a circuit board, the warp of the circuit board can be suppressed. In one example, when the warp amount is measured by the method described in <Test Example 2: Warp Measurement Test> in the examples described later, the range of the warp amount is preferably less than 2,500 μm, and more preferably 2,000 μm or less.

[0161] The cured product of the resin composition according to this embodiment can have excellent adhesion to the conductor layer. This adhesion can be represented by the magnitude of the load (adhesion strength) required to peel off the conductor layer provided on the cured product. In one example, when the adhesion strength is measured by the method described in <Test Example 4: Measurement Test of Adhesion Strength> in the examples described later, the range of the adhesion strength is preferably 0.3 kgf / cm or more, and more preferably 0.4 kgf / cm or more. The upper limit is preferably larger and can be, for example, 1.0 kgf / cm or less.

[0162] <Uses of the resin composition> The resin composition according to this embodiment can be used for forming an insulating layer, and is particularly preferably used for forming an insulating layer of a circuit board. Further, the resin composition may be used for manufacturing a resin sheet. Usually, an insulating layer is formed using this resin sheet. Further, the resin composition may be used for other applications, for example, it may be used for applications such as solder resist, underfill material, die bonding material, hole filling resin, encapsulating resin, and component embedding resin.

[0163] <Resin sheet> The resin sheet according to one embodiment of the present invention includes a support and a resin composition layer formed on the support. The resin composition layer contains the resin composition described above, and preferably contains only the resin composition described above.

[0164] From the viewpoint of thinning, the thickness of the resin composition layer included in the resin sheet is preferably 200 μm or less, more preferably 150 μm or less, and still more preferably 100 μm or less. The lower limit of the thickness of the resin composition layer can be, for example, 1 μm or more, 3 μm or more, 5 μm or more, etc.

[0165] Examples of the support include a film of a plastic material, a metal foil, and a release paper, and a film of a plastic material and a metal foil are preferred.

[0166] When using a film of a plastic material as the support, examples of the plastic material include polyesters such as polyethylene terephthalate (hereinafter sometimes abbreviated as "PET") and polyethylene naphthalate (hereinafter sometimes abbreviated as "PEN"), polycarbonate (hereinafter sometimes abbreviated as "PC"), acrylics such as polymethyl methacrylate (PMMA), cyclic polyolefins, triacetyl cellulose (TAC), polyethersulfide (PES), polyether ketone, polyimide, and the like. Among them, polyethylene terephthalate and polyethylene naphthalate are preferred, and inexpensive polyethylene terephthalate is particularly preferred.

[0167] When using a metal foil as the support, examples of the metal foil include, for example, copper foil, aluminum foil, etc., and copper foil is preferred. As the copper foil, a foil made of single metal copper may be used, or a foil made of an alloy of copper and other metals (for example, tin, chromium, silver, magnesium, nickel, zirconium, silicon, titanium, etc.) may be used.

[0168] The support may be subjected to surface treatments such as mat treatment, corona treatment, antistatic treatment, etc. on the surface that joins the resin composition layer.

[0169] As the support, a support with a release layer having a release layer on the surface that joins the resin composition layer may be used. Examples of the release agent used for the release layer of the support with a release layer include one or more release agents selected from the group consisting of alkyd-based release agents, polyolefin-based release agents, urethane-based release agents, and silicone-based release agents. As the support with a release layer, commercially available products may be used. For example, "PET501010", "SK-1", "AL-5", "AL-7" manufactured by Lintec Corporation, which are PET films having a release layer mainly composed of a silicone-based release agent or an alkyd resin-based release agent; "Lumirror T60" manufactured by Toray Industries, Inc.; "Purex" manufactured by Teijin Limited; "Unipile" manufactured by Unitika Ltd., etc.

[0170] The thickness of the support is not particularly limited, but is preferably 1 μm or more, more preferably 5 μm or more, still more preferably 10 μm or more, and preferably 75 μm or less, more preferably 60 μm or less, still more preferably 50 μm or less. When using a support with a release layer, it is preferable that the total thickness of the support with a release layer is within the above range.

[0171] The resin sheet may be provided with any member as required. For example, the resin sheet may be provided with a protective film for protecting the resin composition layer. The protective film is usually provided on the surface of the resin composition layer that is not joined to the support (i.e., the surface opposite to the support). The thickness of the protective film is not particularly limited, but is, for example, 1 μm to 40 μm. When the protective film is provided, adhesion of dust and scratches to the surface of the resin composition layer can be suppressed.

[0172] The resin sheet can be manufactured, for example, by a method including forming a resin composition layer on a support. To give a specific example, a liquid (varnish-like) resin composition is used as it is, or a solvent and the resin composition are mixed to prepare a liquid (varnish-like) resin composition, which is applied onto the support and further dried as necessary to form a thermosetting resin composition layer, whereby the resin sheet may be manufactured. As the solvent, the same solvents as the (J) solvents described as components of the resin composition may be used.

[0173] The application of the resin composition can be carried out using an application device such as a die coater. Also, the drying can be carried out by a drying method such as heating or hot air blowing. The drying conditions are not particularly limited, but the resin composition layer is dried so that the content of the solvent in the resin composition layer is usually 10% by mass or less, preferably 5% by mass or less. Although it may vary depending on the boiling point of the solvent, for example, when a resin composition containing 30% by mass to 60% by mass of the solvent is used, the resin composition layer can be formed by drying at 50°C to 150°C for 3 minutes to 10 minutes.

[0174] The manufactured resin sheet can be wound into a roll and stored. When the resin sheet has a protective film, usually, the resin sheet can be used by peeling off the protective film.

[0175] <Circuit board> The circuit board according to an embodiment of the present invention includes a cured product of the resin composition described above. Usually, the circuit board includes an insulating layer, and this insulating layer includes a cured product of the resin composition. The insulating layer may include only the cured product of the resin composition. The thickness of the insulating layer is not particularly limited and can be, for example, in the same range as the thickness of the resin composition layer provided in the resin sheet. Also, the insulating layer can usually have the same characteristics as the cured product of the resin composition described above.

[0176] Preferably, the circuit board includes an inner layer substrate, and the above-mentioned insulating layer is provided on this inner layer substrate. Also, the circuit board may include a conductor layer. For example, a conductor layer may be provided on the insulating layer. Hereinafter, an example of a preferred method for manufacturing a circuit board will be described.

[0177] The method for manufacturing a circuit board according to a preferred example is Step (I) of forming a resin composition layer on the inner layer substrate, Step (II) of curing the resin composition layer and includes.

[0178] The "inner layer substrate" is a member that serves as the base material of the circuit board, and examples include a glass epoxy substrate, a metal substrate, a polyester substrate, a polyimide substrate, a BT resin substrate, a thermosetting polyphenylene ether substrate, etc. Also, the inner layer substrate may have a conductor layer on one or both sides thereof. Also, the conductor layer provided on the inner layer substrate may be pattern-processed. The inner layer substrate with a conductor layer (circuit) formed on one or both sides of the substrate is sometimes referred to as an "inner layer circuit board". Also, when manufacturing a circuit board, an intermediate product on which an insulating layer and / or a conductor layer should be further formed is also included in the term "inner layer substrate". Also, an inner layer substrate incorporating components may be used.

[0179] The formation of the resin composition layer on the inner layer substrate may be carried out, for example, by a formation method including applying the resin composition on the inner layer substrate and drying it as necessary, but it is preferably carried out using a resin sheet. The formation method of the resin composition layer using a resin sheet generally includes laminating the resin sheet and the inner layer substrate. The lamination of the resin sheet and the inner layer substrate is carried out so that the resin composition layer of the resin sheet and the inner layer substrate are joined. This lamination may be carried out, for example, by heat-pressing the resin sheet onto the inner layer substrate from the support side. Examples of the member for heat-pressing the resin sheet onto the inner layer substrate (hereinafter also referred to as "heat-pressing member") include a heated metal plate (such as a SUS mirror plate) or a metal roll (such as a SUS roll). It should be noted that it is preferable to press through an elastic material such as heat-resistant rubber so that the resin sheet sufficiently follows the surface unevenness of the inner layer substrate instead of directly pressing the heat-pressing member against the resin sheet.

[0180] The lamination of the inner layer substrate and the resin sheet may be carried out by a vacuum lamination method. In the vacuum lamination method, the heat-pressing temperature is preferably in the range of 60°C to 160°C, more preferably in the range of 80°C to 140°C; the heat-pressing pressure is preferably in the range of 0.098 MPa to 1.77 MPa, more preferably in the range of 0.29 MPa to 1.47 MPa; and the heat-pressing time is preferably in the range of 20 seconds to 400 seconds, more preferably in the range of 30 seconds to 300 seconds. The lamination is preferably carried out under reduced pressure conditions with a pressure of 26.7 hPa or less.

[0181] The lamination may be carried out by a commercially available vacuum laminator. Examples of commercially available vacuum laminators include a vacuum pressurization type laminator manufactured by Meiki Seisakusho Co., Ltd., a vacuum applicator manufactured by Nikkō Materials Co., Ltd., a batch type vacuum pressurization laminator, and the like.

[0182] The method for manufacturing a circuit board may include, after lamination, performing a smoothing process on the resin sheet by pressing a heat-bonding member from the support side under normal pressure (atmospheric pressure). The pressing conditions for the smoothing process may be the same as those for the heat-bonding of the above lamination. The smoothing process can be performed by a commercially available laminator. Lamination and the smoothing process may be continuously performed using the above-mentioned commercially available vacuum laminator.

[0183] The method for manufacturing a circuit board according to this example includes a step (II) of curing the resin composition layer after step (I). By curing the resin composition layer in step (II), an insulating layer including a cured product of the resin composition can be formed.

[0184] The curing of the resin composition layer is usually performed by heat curing. The heat curing conditions of the resin composition layer may vary depending on the type of the resin composition. For example, the curing temperature is preferably 120°C to 240°C, more preferably 150°C to 220°C, and even more preferably 170°C to 210°C. Also, the curing time may be preferably 5 minutes to 120 minutes, more preferably 10 minutes to 100 minutes, and even more preferably 15 minutes to 100 minutes.

[0185] The method for manufacturing a circuit board may include preheating the resin composition layer at a temperature lower than the curing temperature before the heat curing of the resin composition layer. For example, prior to curing the resin composition layer, the resin composition layer is usually preheated at a temperature of 50°C to 150°C, preferably 60°C to 140°C, more preferably 70°C to 130°C for usually 5 minutes or more, preferably 5 minutes to 150 minutes, more preferably 15 minutes to 120 minutes, and even more preferably 15 minutes to 100 minutes. The preheating is usually performed after step (I). Also, when the smoothing process is performed after the lamination of the inner layer substrate and the resin sheet, the preheating can usually be performed after the smoothing process.

[0186] When using a resin sheet, the method for manufacturing a circuit board may include a step of peeling the support of the resin sheet after laminating the inner layer substrate and the resin sheet. The peeling of the support may be performed between step (I) and step (II), or may be performed after step (II). Further, when the method for manufacturing a circuit board includes a step (III) of forming holes such as via holes and through holes in the insulating layer, a step (IV) of roughening the insulating layer, and a step (V) of forming a conductor layer, as described later, the peeling of the support may be carried out between step (II) and step (III), between step (III) and step (IV), or between step (IV) and step (V).

[0187] The method for manufacturing a circuit board may include a step (III) of forming holes such as via holes and through holes in the insulating layer after step (II). The method for forming the holes can be selected according to factors such as the composition of the resin composition used for forming the insulating layer. For example, holes may be formed by processing methods such as drilling, laser processing, and plasma processing. Among them, laser processing is preferable. For example, holes may be formed by irradiating the insulating layer with laser light after peeling the support, or holes may be formed by irradiating the insulating layer with laser light through the support. The dimensions and shapes of the holes may be appropriately determined according to the design of the circuit board.

[0188] The method for manufacturing a circuit board may include a step (IV) of performing a roughening treatment on the insulating layer. According to the roughening treatment, roughening of the surface of the insulating layer can be performed. Further, according to the roughening treatment, smears (resin residues) can be removed from the insulating layer. Therefore, this roughening treatment may be called a "desmear treatment". For example, when holes are formed in step (III), smears may be formed in the holes, so it is preferable to perform the roughening treatment of step (IV) after step (III) to remove the above-mentioned smears.

[0189] The procedures and conditions of the roughening treatment are not particularly limited, and known procedures and conditions commonly used when forming the insulating layer of the circuit board can be adopted. For example, a swelling treatment with a swelling liquid, an oxidation treatment with an oxidizing agent, and a neutralization treatment with a neutralizing liquid may be sequentially performed on the insulating layer to perform the roughening treatment.

[0190] Examples of the swelling liquid used for the roughening treatment include, for example, an alkaline solution, a surfactant solution, etc., and an alkaline solution is preferred. As the alkaline solution, a sodium hydroxide solution and a potassium hydroxide solution are more preferred. Examples of commercially available swelling liquids include, for example, "Swelling Dip Securigant P" and "Swelling Dip Securigans SBU" manufactured by Atotech Japan Co., Ltd. The swelling treatment with the swelling liquid can be carried out, for example, by immersing the insulating layer in the swelling liquid at 30°C to 90°C for 1 minute to 20 minutes. From the viewpoint of suppressing the swelling of the resin of the insulating layer to an appropriate level, it is preferable to immerse the insulating layer in the swelling liquid at 40°C to 80°C for 5 minutes to 15 minutes.

[0191] Examples of the oxidizing agent used for the roughening treatment include, for example, an alkaline permanganate solution in which potassium permanganate or sodium permanganate is dissolved in an aqueous solution of sodium hydroxide. The oxidation treatment with an oxidizing agent such as an alkaline permanganate solution is preferably carried out by immersing the insulating layer in the oxidizing agent solution heated to 60°C to 100°C for 10 minutes to 30 minutes. Further, the concentration of the permanganate in the alkaline permanganate solution is preferably 5% by mass to 10% by mass. Examples of commercially available oxidizing agents include, for example, alkaline permanganate solutions such as "Concentrate Compact CP" and "Dosing Solution Securigans P" manufactured by Atotech Japan Co., Ltd.

[0192] As the neutralizing liquid used for the roughening treatment, an acidic aqueous solution is preferred, and examples of commercially available products include, for example, "Reduction Solution Securigant P" manufactured by Atotech Japan Co., Ltd. The neutralization treatment with the neutralizing liquid can be carried out by immersing the treated surface subjected to the oxidation treatment with the oxidizing agent in the neutralizing liquid at 30°C to 80°C for 5 minutes to 30 minutes. From the viewpoint of workability, a method of immersing the object subjected to the oxidation treatment with the oxidizing agent in the neutralizing liquid at 40°C to 70°C for 5 minutes to 20 minutes is preferred.

[0193] The method for manufacturing a circuit board may include a step (V) of forming a conductor layer on an insulating layer. When the method for manufacturing a circuit board includes step (III) or (IV), the step (V) of forming a conductor layer is preferably performed usually after steps (III) and (IV).

[0194] The conductor material used for the conductor layer is not particularly limited. In a preferred embodiment, the conductor layer contains one or more metals selected from the group consisting of gold, platinum, palladium, silver, copper, aluminum, cobalt, chromium, zinc, nickel, titanium, tungsten, iron, tin, and indium. The conductor layer may be a single-metal layer or an alloy layer. Examples of the alloy layer include a layer formed from an alloy of two or more metals selected from the above group (for example, nickel-chromium alloy, copper-nickel alloy, and copper-titanium alloy). Among them, from the viewpoints of versatility in forming the conductor layer, cost, ease of patterning, etc., a single-metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver, or copper, or an alloy layer of nickel-chromium alloy, copper-nickel alloy, or copper-titanium alloy is preferred, a single-metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver, or copper, or an alloy layer of nickel-chromium alloy is more preferred, and a single-metal layer of copper is even more preferred.

[0195] The conductor layer may have a single-layer structure or may have a multi-layer structure including two or more single-metal layers or alloy layers made of different types of metals or alloys. When the conductor layer has a multi-layer structure, the layer in contact with the insulating layer is preferably a single-metal layer of chromium, zinc, or titanium, or an alloy layer of nickel-chromium alloy.

[0196] The thickness of the conductor layer depends on the design of the circuit board, but is preferably 3 μm to 35 μm, more preferably 5 μm to 30 μm.

[0197] The conductor layer may be formed by plating. For example, a plating layer (plating seed layer) can be formed on the surface of the insulating layer by a conventionally known technique such as a semi-additive method or a full-additive method to form a conductor layer having a desired wiring pattern. From the viewpoint of manufacturing simplicity, the semi-additive method is preferred. Hereinafter, an example of forming the conductor layer by the semi-additive method is shown.

[0198] First, an electroless plating layer (plating seed layer) is formed on the surface of the insulating layer by electroless plating. Next, a mask pattern is formed on the formed electroless plating layer to expose a part of the electroless plating layer corresponding to the desired wiring pattern. After forming an electrolytic plating layer by electrolytic plating on the exposed electroless plating layer, the mask pattern is removed. Then, the unnecessary electroless plating layer can be removed by etching to form a conductor layer having a desired wiring pattern.

[0199] As another example, the conductor layer may be formed using a metal foil. When forming the conductor layer using a metal foil, step (V) is preferably carried out between step (I) and step (II). For example, after step (I), the support is removed, and a metal foil is laminated on the surface of the exposed resin composition layer. The lamination of the resin composition layer and the metal foil may be carried out by a vacuum lamination method. The lamination conditions may be the same as those described for step (I). Next, step (II) is carried out to form an insulating layer. Then, using the metal foil on the insulating layer, a conductor layer having a desired wiring pattern can be formed by a known technique such as a subtractive method or a modified semi-additive method. The metal foil can be manufactured by a known method such as an electrolytic method or a rolling method. Examples of commercially available metal foils include HLP foil, JXUT-III foil manufactured by JX Metals, 3EC-III foil, TP-III foil manufactured by Mitsui Mining & Smelting Co., Ltd., etc.

[0200] When a conductor layer is formed on an insulating layer, the method for manufacturing a circuit board may include performing an annealing process after the formation of the conductor layer. According to the annealing process, the adhesion between the insulating layer and the conductor layer can be enhanced. The annealing process can be performed, for example, by heating at 150°C to 210°C for 20 minutes to 180 minutes.

[0201] In the method for manufacturing a circuit board, each of the above-described steps may be performed only once, or may be repeated two or more times. For example, steps (I) to (V) may be repeatedly performed to form a circuit board having a multilayer structure such as a multilayer printed wiring board including a plurality of insulating layers and conductor layers.

[0202] The method for manufacturing a circuit board may further include any arbitrary steps in combination with the above-described steps. For example, the method for manufacturing a circuit board may include a step of providing a semiconductor chip so as to be joined to the conductor layer. As a specific example, when manufacturing a circuit board for a semiconductor chip package including a semiconductor chip, the method for manufacturing a circuit board may include a step of providing a semiconductor chip. For the semiconductor chip, appropriate conditions under which the terminal electrode of the semiconductor chip and the conductor layer formed on the insulating layer can be conductively connected can be adopted. For example, conditions used in flip chip mounting may be adopted. Also, the semiconductor chip may be joined via an insulating adhesive, or may be joined by reflow. Further, if necessary, the provided semiconductor chip may be filled with a mold underfill material. Also, the method for manufacturing a circuit board may include, for example, a step of forming a sealing layer, a step of forming a solder resist layer, a step of dicing the manufactured circuit board into individual pieces, and the like.

[0203] Examples of the circuit board include, for example, printed wiring boards and semiconductor chip packages. Examples of the semiconductor chip package include, for example, FC-CSP, MIS-BGA package, ETS-BGA package, Fan-out type WLP (Wafer Level Package), Fan-in type WLP, Fan-out type PLP (Panel Level Package), and Fan-in type PLP. In these semiconductor chip packages, it is preferable to form a redistribution layer as an insulating layer with a cured product obtained by curing the above-described resin composition. However, the circuit board is not limited to those exemplified here.

[0204] <Semiconductor device> The above-described circuit board can be used in the manufacture of a semiconductor device. The semiconductor device includes the above-described circuit board. Examples of the semiconductor device include various semiconductor devices used in electrical products (for example, computers, mobile phones, smartphones, tablet devices, wearable devices, digital cameras, medical devices, and televisions, etc.) and vehicles (for example, motorcycles, automobiles, trains, ships, and airplanes, etc.).

Example

[0205] Hereinafter, the present invention will be specifically described with reference to examples. However, the present invention is not limited to these examples. In the following description, "parts" and "%" representing amounts mean "parts by mass" and "mass %", respectively, unless otherwise specified. Further, the temperature conditions and pressure conditions in the case of no particular designation were room temperature (23 ° C) and atmospheric pressure (1 atm). In the following description, unless otherwise specified, "MIBK" represents methyl isobutyl ketone.

[0206] <Synthesis Example 1: Synthesis of epoxy resin (A1)> (Explanation of measurement method) (1) Hydroxyl equivalent: The hydroxyl equivalent was measured in accordance with JIS K0070 standard, and the unit was expressed as "g / eq.". Unless otherwise specified, the hydroxyl equivalent of the phenolic resin represents the phenolic hydroxyl equivalent.

[0207] (2) Softening point: The softening point was measured in accordance with JIS K7234 standard, ring and ball method. Specifically, an automatic softening point apparatus ("ASP-MG4" manufactured by Matech Co., Ltd.) was used.

[0208] (3) Epoxy equivalent: The epoxy equivalent was measured in accordance with JIS K7236 standard, and the unit was expressed as "g / eq.". Specifically, an automatic potentiometric titrator ("COM-1600ST" manufactured by Hiranuma Sangyo Co., Ltd.) was used. Chloroform was used as the solvent, and a brominated tetraethylammonium acetate solution was added, followed by titration with a 0.1 mol / L perchloric acid - acetic acid solution.

[0209] (4) Total chlorine content: The total chlorine content was measured in accordance with JIS K7243-3 standard, and the unit was expressed as "ppm". Specifically, diethylene glycol monobutyl ether was used as the solvent, and a 1 mol / L potassium hydroxide 1,2-propanediol solution was added for heat treatment. Then, an automatic potentiometric titrator ("COM-1700" manufactured by Hiranuma Sangyo Co., Ltd.) was used for titration with a 0.01 mol / L silver nitrate solution.

[0210] (5) Melt viscosity: The melt viscosity was measured at 150 °C using an ICI viscosity measuring apparatus ("CV-1S" manufactured by Toa Industries, Ltd.).

[0211] (6) GPC (gel permeation chromatography) measurement: The GPC measurement was performed using a device equipped with columns (TOSOH's "TSKgel G4000HXL", "TSKgel G3000HXL", "TSKgel G2000HXL") in series on the main body (TOSOH's "HLC-8220GPC") at a column temperature of 40°C. Tetrahydrofuran (THF) was used as the eluent, with a flow rate of 1 mL / min, and a differential refractive index detector was used as the detector. For the measurement sample, 50 μL of a solution prepared by dissolving 0.1 g of the sample in 10 mL of THF and filtering it through a microfilter was used. Data processing was performed using "GPC-8020 Model II Version 6.00" manufactured by TOSOH Corporation.

[0212] (7) IR (Infrared Absorption Spectrum): Using a Fourier transform infrared spectrophotometer (Perkin Elmer Precisely's "Spectrum One FT-IR Spectrumeter 1760X"), sodium chloride was used for the cell. After applying and drying a sample dissolved in chloroform on the cell, the transmittance was measured in the wavenumber range of 450 cm -1 ~4000 cm -1 .

[0213] (8) ESI-MS: Using a mass spectrometer (Shimadzu Corporation's "LCMS-2020"), acetonitrile and water were used as the mobile phase, and mass spectrometry was performed by measuring a sample dissolved in acetonitrile.

[0214] (Step 1. Synthesis of Polyhydric Hydroxy Resin (PH1)) A reaction apparatus consisting of a glass separable flask equipped with a stirrer, a thermometer, a nitrogen blowing tube, a dropping funnel, and a cooling tube was charged with 500 parts of 2,6-xylenol and 7.1 parts of 47% BF3 ether complex, and heated to 100 °C while stirring. While maintaining the same temperature, 60.1 parts (0.11 times the molar amount relative to 2,6-xylenol) of dicyclopentadiene were added dropwise over 1 hour. Further, the reaction was carried out at a temperature of 115 °C to 125 °C for 4 hours. Thereafter, 560 parts of MIBK were added to dissolve the product. 19.0 parts of sodium hydrogen carbonate were added, 507 parts of warm water at 80 °C were added for washing with water, and the lower aqueous layer was separated and removed. Thereafter, it was heated to 160 °C for dehydration. Thereafter, it was heated to 200 °C under a reduced pressure of 5 mmHg to evaporate and remove unreacted raw materials. 1320 parts of MIBK were added to dissolve the product, 400 parts of warm water at 80 °C were added for washing with water, and the lower water layer was separated and removed. It was heated to 120 °C for reflux dehydration and filtered. Thereafter, it was heated to 160 °C under a reduced pressure of 5 mmHg to evaporate and remove MIBK, and 164 parts of a reddish-brown polyhydroxy resin (PH1, resin of the following formula (A-5), R a1 is a methyl group, i a is 2) were obtained.

[0215]

Chemical formula

[0216] The obtained polyhydroxy resin (PH1) had a hydroxyl equivalent of 195 g / eq. and a softening point of 73 °C. Also, the weight average molecular weight Mw measured by GPC of the polyhydroxy resin (PH1) was 470, the number average molecular weight Mn was 440, m a =0 body content was 2.8 area%, m a =1 body content was 86.2 area%, m a =2 or more bodies content was 11.0 area%. The melt viscosity of the polyhydroxy resin (PH1) at 150 °C was 0.05 Pa·s.

[0217] (Step 2. Synthesis of polyhydroxy resin (PH2)) Into a reactor similar to that in Step 1, 500 parts of the polyhydroxy resin (PH1) obtained in Step 1 and 125 parts of MIBK were charged, and the mixture was heated to 100 °C while stirring. 5.0 parts of 47% BF3 ether complex was charged, and while maintaining the same temperature, 75.0 parts of dicyclopentadiene (0.22 times the molar amount relative to the hydroxyl groups of the polyhydroxy resin (PH1)) was added dropwise over 1 hour. Further, the reaction was carried out at a temperature of 115 °C to 125 °C for 4 hours. Thereafter, 669 parts of MIBK was added to dissolve the product. 13.3 parts of sodium hydrogen carbonate was added, 521 parts of warm water at 80 °C was added for washing, and the lower aqueous layer was separated and removed. The mixture was heated to 120 °C for reflux dehydration and then filtered. Thereafter, under a reduced pressure of 5 mmHg, the mixture was heated to 160 °C to evaporate and remove MIBK, and 558 parts of a reddish-brown polyhydroxy resin (PH2, the resin of formula (A-6), R a1 is a methyl group, i a is 2) was obtained.

[0218] [Chemical formula]

[0219] In the FT-IR measurement of the obtained polyhydroxy resin (PH2), a peak derived from the C-H stretching vibration of the olefin site of the dicyclopentadiene skeleton indicating that the dicyclopentenyl group was introduced as the side chain R a6 appeared around 3040 cm -1 . The hydroxyl equivalent of the polyhydroxy resin (PH2) was 234 g / eq., and the softening point was 86 °C. The weight average molecular weight Mw measured by GPC of the polyhydroxy resin (PH2) was 560, the number average molecular weight Mn was 470, k a =0 body content was 6.2 area%, k a =1 body content was 74.0 area%, k a =2 or more body content was 19.8 area%. The melt viscosity of the polyhydroxy resin (PH2) at 150 °C was 0.15 Pa·s.

[0220] (Step 3. Synthesis of polyhydroxy resin (P1)) Into a reactor similar to that in Step 1, 100 parts of the polyhydroxy resin (PH2) obtained in Step 2, 1.0 part of p-toluenesulfonic acid monohydrate, and 25 parts of MIBK were charged, and the mixture was heated to 120 °C while stirring. While maintaining the same temperature, 20 parts (0.36-fold molar to the hydroxyl groups of PH2) of divinylbenzene (manufactured by Aldrich, 55% divinylbenzene, 45% ethylvinylbenzene) was added dropwise over 1 hour. Further, the reaction was carried out at a temperature of 120 °C to 130 °C for 4 hours. 155 parts of MIBK was added to dissolve the product, which was then neutralized with 1.3 parts of sodium hydrogen carbonate, washed with 105 parts of warm water at 90 °C, and the lower-layer water tank was separated and removed. The mixture was heated to 120 °C for reflux dehydration and then filtered. Thereafter, under a reduced pressure of 5 mmHg, the mixture was heated to 180 °C to evaporate and remove MIBK, and 116 parts of a reddish-brown polyhydroxy resin (P1) was obtained.

[0221] The hydroxyl equivalent of the polyhydroxy resin (P1) was 272 g / eq., and the softening point was 77 °C. The absorption ratio (A3040 / A1210) was 0.23. When the mass spectrum of the polyhydroxy resin (P1) by ESI-MS (negative) was measured, M− = 375, 507, 629, 639, 761 were confirmed, and it was confirmed that it was a polyhydroxy resin of formula (A-4) and had a structure having both a dicyclopentenyl group represented by formula (A-2a) or formula (A-2b) and a group derived from divinylbenzene represented by formula (A-3a) or formula (A-3c) as substituents. The weight-average molecular weight Mw measured by GPC of the polyhydroxy resin (P1) was 693, the number-average molecular weight Mn was 472, a the content of the n a = 0 form was 10.8 area%, the content of the n a = 1 form was 61.4 area%, and the content of the n

[0222] (Step 4. Synthesis of epoxy resin (A1)) Into a reactor equipped with a stirrer, a thermometer, a nitrogen injection tube, a dropping funnel, and a cooling tube, 100 parts of the polyhydric hydroxy resin (P1) obtained in Step 3, 170.1 parts of epichlorohydrin (the following formula (X1)), and 25.5 parts of diethylene glycol dimethyl ether were added and heated to 65°C.

[0223]

Chemical formula

[0224] While maintaining the temperature at 63°C to 67°C under a reduced pressure of 125 mmHg, 25.5 parts of a 49% aqueous sodium hydroxide solution was added dropwise over 3 hours. During this period, epichlorohydrin was azeotroped with water, and the water flowing out was sequentially removed from the system. After the reaction was completed, epichlorohydrin was recovered under the conditions of 5 mmHg and 180°C, and 281 parts of MIBK was added to dissolve the product. Then, 240 parts of water was added to dissolve the by-produced sodium chloride, and the mixture was allowed to stand to separate and remove the lower-layer sodium chloride solution. After neutralizing with an aqueous phosphoric acid solution, the resin solution was washed with water until the washing liquid became neutral and then filtered. Under a reduced pressure of 5 mmHg, it was heated to 180°C to distill off MIBK, and 117 parts of a reddish-brown epoxy resin (A1) represented by the formula (A-1) was obtained.

[0225] The epoxy equivalent of the epoxy resin (A1) was 354 g / eq., the total chlorine content was 1362 ppm, and the softening point was 59°C. When the mass spectrum was measured by ESI-MS (negative), M− = 487, 619, 797 were confirmed. The weight-average molecular weight Mw measured by GPC of the epoxy resin (A1) was 755, the number-average molecular weight Mn was 475, the content of the n a =0 species was 9.1 area%, the content of the n a =1 species was 41.1 area%, and the content of the n a =2 or more species was 49.8 area%. The melt viscosity of the epoxy resin (A1) at 150°C was 0.15 Pa·s.

[0226] <Synthesis Example 2: Synthesis of Low-Elastic Polymer (D1)> Into a reaction vessel, 69 g of a difunctional hydroxy-terminated polybutadiene (manufactured by Nippon Soda Co., Ltd., "G-3000", number average molecular weight = 3000, hydroxy group equivalent = 1800 g / eq.), 40 g of PGMEA (manufactured by Showa Denko K.K., propylene glycol monomethyl ether acetate), and 0.005 g of dibutyltin laurate were placed and mixed to dissolve uniformly. When it became uniform, the temperature was raised to 60 °C, and while further stirring, 8 g of isophorone diisocyanate (manufactured by Evonik Degussa Japan Co., Ltd., "IPDI", isocyanate group equivalent = 113 g / eq.) was added, and the reaction was carried out for about 3 hours.

[0227] Next, 23 g of a cresol novolak resin (manufactured by DIC Corporation, "KA-1160", hydroxyl group equivalent = 117 g / eq.) and 60 g of PGMEA were added to the reaction product, and while stirring, the temperature was raised to reflux at 150 °C, and the reaction was carried out for about 10 hours. The disappearance of the NCO peak at 2250 cm -1 was confirmed by FT-IR. The disappearance of the NCO peak was regarded as the end point of the reaction, and the reaction product was cooled to room temperature. Then, the reaction product was filtered through a 100-mesh filter cloth to obtain a low-elastic polymer (D1) having a butadiene structure and phenolic hydroxyl groups (phenolic hydroxyl group-containing butadiene resin: non-volatile component 50% by mass). The weight average molecular weight of the low-elastic polymer (D1) was 27,000, and the glass transition temperature was -7 °C.

[0228] The elastic modulus of the obtained low-elastic polymer (D1) was measured by the following elastic modulus measurement method. That is, a polyethylene terephthalate film (manufactured by Toray Industries, Inc., "Lumirror R80", thickness 38 μm, softening point 130 °C) subjected to a release treatment with an alkyd resin-based release agent (manufactured by Lintec Corporation, "AL-5") was prepared. The low-elastic polymer (D1) was uniformly applied on the support by a die coater so that the thickness of the polymer layer after drying was 50 μm, and dried at 70 °C to 120 °C for 10 minutes to form a low-elastic polymer layer. This low-elastic polymer layer was peeled off from the support, and the elastic modulus was measured by a tensile test (temperature 25 °C, humidity 40% RH) conforming to JIS K7161, and it was confirmed that the elastic modulus of the low-elastic polymer (D1) was 0.05 GPa.

[0229] <Synthesis Example 3: Synthesis of Low Elastic Polymer (D2)> Into a flask equipped with a stirrer, thermometer, and condenser, 368.41 g of ethyl diglycol acetate and 368.41 g of an aromatic solvent ("Solvesso 150 (registered trademark)" manufactured by ExxonMobil) were charged as solvents. Further, 100.1 g (0.4 mol) of diphenylmethane diisocyanate and 400 g (0.2 mol) of polycarbonate diol ("C-2015N" manufactured by Kuraray, number average molecular weight: about 2000, hydroxyl equivalent weight: 1000 g / eq., non-volatile component: 100% by mass) were charged into the flask, and the reaction was carried out at 70 °C for 4 hours. Thereby, a first reaction solution was obtained.

[0230] Next, 195.9 g (0.2 mol) of nonylphenol novolak resin (hydroxyl equivalent weight: 229.4 g / eq, average functionality 4.27, average calculated molecular weight: 979.5 g / mol) and 41.0 g (0.1 mol) of ethylene glycol bisanhydrotrimellitate were charged into the flask, and the temperature was raised to 150 °C over 2 hours and reacted for 12 hours. Thereby, a second reaction solution was obtained. The disappearance of the NCO peak at 2250 cm -1 was confirmed by FT-IR. The disappearance of the NCO peak was regarded as the end point of the reaction, and the second reaction solution was cooled to room temperature. Then, the second reaction solution was filtered through a 100-mesh filter cloth. Thereby, a low elastic polymer (D2) having a phenolic hydroxyl group (phenolic hydroxyl group-containing polycarbonate resin: non-volatile component 50% by mass) was obtained as a filtrate. The weight average molecular weight of the low elastic polymer (D2) was 20,000, and the glass transition temperature was 5 °C. It was confirmed that the elastic modulus of the low elastic polymer (D2) measured by the same elastic modulus measurement method as that of the low elastic polymer (D1) by a tensile test (temperature 25 °C, humidity 40% RH) conforming to JIS K7161 was 0.5 GPa.

[0231] <Synthesis Example 4: Synthesis of Low Elastic Polymer (D3)> Into a 1 L separable flask equipped with an oil bath and a stirrer bar, while introducing nitrogen gas, 200 g of cyclohexanone was added. As diamine, 149.4 g of a dimer acid type diamine (“PRIAMINE 1075” manufactured by Croda Japan) and, as a monoamine compound, 4.7 g of m-aminophenol were added with stirring. Subsequently, as tetracarboxylic acids, 67.3 g of 1,2,4,5-cyclohexanetetracarboxylic dianhydride was added and stirred at room temperature for 30 minutes. This was heated to 100 °C and stirred for 3 hours, then the oil bath was removed and it was returned to room temperature to obtain a varnish-like polyimide precursor. Thereafter, while removing the water distilled off using a Dean-Stark trap outside the system, heating was carried out at 170 °C for 10 hours for imidization to obtain a low-elastic polymer (D3) having a carbon skeleton derived from dimer acid (non-volatile component 50 mass%). The weight average molecular weight of the obtained low-elastic polymer (D4) was 10,000. By the same elastic modulus measurement method as that of the low-elastic polymer (D1), it was confirmed that the elastic modulus of the low-elastic polymer (D3) measured by a tensile test (temperature 25 °C, humidity 40% RH) conforming to JIS K7161 was 0.2 GPa.

[0232] <Synthesis Example 5: Synthesis of maleimide resin (F1)> A MEK solution (non-volatile component 60 mass%) of the maleimide resin (F1) synthesized by the method described in Synthesis Example 1 of Publication No. 2020-500211 of the Technical Report of the Japan Institute of Invention was prepared. This maleimide resin (F1) had a structure represented by the following formula (F-1) and a weight average molecular weight of 2000.

[0233] [Chemical formula]

[0234] <Examples 1 to 13 and Comparative Examples 1 to 4> (1) Production of resin composition: Weighed and mixed each component in the amounts (parts by mass) shown in Table 1 and Table 2. Further, 15 parts of MEK and 15 parts of cyclohexanone were mixed and uniformly dispersed using a high-speed rotary mixer to obtain a resin composition (resin varnish). The details of each component shown in Table 1 and Table 2 are as follows.

[0235] (A) First epoxy resin: "Epoxy resin A1": The epoxy resin (A1) synthesized in Synthesis Example 1, epoxy equivalent 354 g / eq.

[0236] (B) Second epoxy resin: "ESN-4100V": A naphthalene-type epoxy resin containing a methoxy group-containing naphthol aralkyl structure (manufactured by Nippon Steel Chemical & Material Co., Ltd., epoxy equivalent 360 g / eq.). "ZX-1059": A bisphenol-type epoxy resin (a 1:1 mixture of bisphenol A-type epoxy resin and bisphenol F-type epoxy resin manufactured by Nippon Steel Chemical & Material Co., Ltd., epoxy equivalent 169 g / eq.). "NC3100": A biphenyl-type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent 258 g / eq.). "HP6000H": A naphthylene ether-type epoxy resin (manufactured by DIC Corporation, epoxy equivalent 250 g / eq.). "WHR991S": A phenolphthalimide-type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent 266 g / eq.). "HP4032SS": A naphthalene-type epoxy resin (manufactured by DIC Corporation, epoxy equivalent approximately 144 g / eq.). "YX4000H": A bixylenol-type epoxy resin (manufactured by Mitsubishi Chemical Corporation, epoxy equivalent approximately 185 g / eq.).

[0237] (C) Curing agent: "HPC-8000-65T": An active ester compound (manufactured by DIC Corporation, active group equivalent approximately 223 g / eq., toluene solution with non-volatile component 65% by mass). "LA3018-50P": Phenolic curing agent containing a triazine skeleton (manufactured by DIC Corporation, 1-methoxy-2-propanol solution with a hydroxyl equivalent of approximately 151 g / eq. and a non-volatile component of 50%). "V-03": Carbodiimide resin (manufactured by Nisshinbo Chemicals, toluene solution with a carbodiimide equivalent of 216 g / eq. and a non-volatile component of 50%). "BA230S75": Prepolymer of bisphenol A dicyanate (manufactured by Lonza, MEK solution with a cyanate group equivalent of approximately 235 g / eq. and a non-volatile component of 75%). "PT30": Phenolic novolac type polyfunctional cyanate ester resin (manufactured by Lonza Japan, cyanate group equivalent of approximately 124 g / eq.).

[0238] (D) Low-elastic polymer: "Polymer D1": Low-elastic polymer (D1) synthesized in Synthesis Example 2, non-volatile component 50 mass%. "Polymer D2": Low-elastic polymer (D2) synthesized in Synthesis Example 3, non-volatile component 50 mass%. "Polymer D3": Low-elastic polymer (D3) synthesized in Synthesis Example 4, non-volatile component 50 mass%.

[0239] (E) Inorganic filler: "SO-C2": Spherical silica (average particle size 0.5 μm, manufactured by Admatechs) surface-treated with an aminosilane coupling agent (Shin-Etsu Chemical Co., Ltd.'s "KBM573"). "Alumina A": Spherical alumina (average particle size 1.0 μm) surface-treated with an aminosilane coupling agent (Shin-Etsu Chemical Co., Ltd.'s "KBM573").

[0240] (F) Polymerizable unsaturated resin: "OPE-2St 1200": Vinylbenzyl-modified polyphenylene ether (manufactured by Mitsubishi Gas Chemical Company, toluene solution with a non-volatile component ratio of 65%). "SLK-6895-T90": Bismaleimide resin (manufactured by Shin-Etsu Chemical Co., Ltd., toluene solution with a maleimide equivalent of approximately 345 g / eq. and a non-volatile component of 90%). "Maleimide Resin F1": The maleimide resin (F1) synthesized in Synthesis Example 5, with a non-volatile content of 60% by mass.

[0241] (G) Organic filler: "EXL2655": An organic filler (manufactured by DOW).

[0242] (H) Curing accelerator: "2P4MZ": 2-Phenyl-4-methylimidazole (manufactured by Shikoku Kasei Kogyo Co., Ltd.). "Co(acac)3": Cobalt(III) acetylacetonate (manufactured by Tokyo Chemical Industry Co., Ltd.).

[0243] (2) Manufacture of resin sheet: As a support, a polyethylene terephthalate film (Toray Industries, Inc.'s "Lumirror R80", thickness 38 μm, softening point 130 °C) that had been subjected to a release treatment with an alkyd resin-based release agent (Lintec Corporation's "AL-5") was prepared. The resin composition was uniformly applied onto the support with a die coater so that the thickness of the resin composition layer after drying would be 50 μm, and dried at 70 °C to 100 °C for 3 minutes to form a resin composition layer. Next, the rough surface of a polypropylene film (Oji F-Tex Co., Ltd.'s "Alpha MA-411", thickness 15 μm) was laminated as a protective film onto the surface of the resin composition layer that was not joined to the support. Thereby, a resin sheet having a support, a resin composition layer, and a protective film in this order was obtained.

[0244] <Test Example 1: Measurement test of dielectric tangent Df> The protective film was peeled off from the resin sheet. After heating at 200 °C for 90 minutes to thermally cure the resin composition layer, the support was peeled off to obtain a cured product. The obtained cured product was cut out into pieces with a width of 2 mm and a length of 80 mm to obtain test pieces for evaluation.

[0245] Regarding the test pieces, using a measuring device (Agilent Technologies' "HP8362B"), the dielectric tangent was measured at a measurement frequency of 5.8 GHz and a measurement temperature of 23 °C by the cavity resonance perturbation method. Measurements were performed on three test pieces, and the average value was calculated. Based on this average value, the dielectric tangent was evaluated according to the following evaluation criteria.

[0246] Evaluation Criteria for Dielectric Loss Tangent "Good": Dielectric loss tangent is 0.004 or less. "Bad": Dielectric loss tangent is greater than 0.004.

[0247] <Test Example 2: Warpage Measurement Test> The resin sheet with the protective film peeled off was laminated over the entire one side of a 12-inch silicon wafer (thickness 775 μm) using a batch-type vacuum pressure laminator (two-stage build-up laminator "CVP700" manufactured by Nippon Materials Co., Ltd.). This lamination was performed so that the resin composition layer and the silicon wafer were joined. The support of the resin sheet was peeled off to expose the resin composition layer. On the surface of this exposed resin composition layer, another resin sheet with the protective film peeled off was similarly laminated, the support was peeled off, and two resin composition layers (total thickness 100 μm) were formed on one side of the 12-inch silicon wafer. Note that the above lamination was performed by reducing the pressure for 30 seconds to make the atmospheric pressure 13 hPa or less, and then pressure-bonding at 100°C and a pressure of 0.74 MPa for 30 seconds.

[0248] The sample laminate was heated in an oven at 100°C for 30 minutes and then further heated at 200°C for 90 minutes to cure the resin composition layer, obtaining a sample laminate having a layer structure of "silicon wafer / hardened product layer". The warpage amount of the obtained sample laminate was measured using a shadow moire measurement device ("Thermoire AXP" manufactured by Akorometrix). The measurement was performed in accordance with JEITA EDX-7311-24 of the Electronic Information Technology Industry Association standard. Specifically, with respect to all the data on the evaluation substrate surface (the surface opposite to the silicon wafer of the hardened product layer) in the measurement region, the difference between the minimum value and the maximum value of the height in the vertical direction from the virtual plane obtained using the least squares method as the reference plane to the evaluation substrate surface was determined as the warpage amount. The measured value of the obtained warpage amount was evaluated according to the following criteria. The smaller the warpage amount, the more effectively the warpage is suppressed.

[0249] Warpage Evaluation Criteria: "Excellent": Warpage amount is 0 μm or more and 2000 μm or less. "Good": The amount of warpage is greater than 2000 μm and less than 2500 μm. "Defective": The amount of warpage is 2500 μm or more.

[0250] <Test Example 3: Measurement Test of Minimum Melting Viscosity> A part of the resin composition layer was peeled off from the resin sheet to obtain a sample of the resin composition, and the melting viscosity was measured using a dynamic viscoelasticity measuring device ("Rheosol-G3000" manufactured by UBM). Specifically, for 1 g of the resin composition sample, using a parallel plate with a diameter of 18 mm, the temperature was raised from an initial temperature of 60 °C to 200 °C at a heating rate of 5 °C / min, and the dynamic viscoelastic modulus was measured under the measurement conditions of a measurement interval temperature of 2.5 °C, a vibration frequency of 1 Hz, and a strain of 5 deg, and the minimum melting viscosity (poise) was calculated. The measured minimum melting viscosity was evaluated according to the following criteria.

[0251] Evaluation Criteria for Minimum Melting Viscosity: "Excellent": The minimum melting viscosity is less than 5000 Poise. "Good": The minimum melting viscosity is 5000 Poise or more and less than 6000 Poise. "Defective": The minimum melting viscosity is 6000 Poise or more.

[0252] <Test Example 4: Measurement Test of Adhesion Strength> (1) Substrate Treatment of Copper Foil: The shiny surface of an electrolytic copper foil ("3EC-III" manufactured by Mitsui Mining & Smelting Co., Ltd., thickness 35 μm) was etched by 1 μm using an etching agent ("CZ8101" manufactured by Meck) to perform roughening treatment of the copper surface. Next, rust preventive treatment was performed on the roughened surface of the copper foil using a rust preventive agent ("CL8300" manufactured by Meck). This copper foil was further heat-treated in an oven at 130 °C for 30 minutes to obtain a CZ-treated copper foil.

[0253] (2) Preparation of Inner Layer Substrate: As the inner layer substrate, a glass cloth base epoxy resin double-sided copper-clad laminate (copper foil thickness 18 μm, substrate thickness 0.4 mm, "R1515A" manufactured by Panasonic) was prepared. Both sides of this inner layer substrate were etched with an etching agent ("CZ8101" manufactured by Meck) by 1 μm to perform roughening treatment of the copper surface. Further, this inner layer substrate was heat-treated in an oven at 130 °C for 30 minutes.

[0254] (3) Lamination of the resin composition layer: The protective film was peeled off from the resin sheet to expose the resin composition layer. Using a batch-type vacuum pressure laminator (manufactured by Nichco Materials, 2-stage build-up laminator "CVP700"), resin sheets were laminated on both sides of the inner layer substrate so that the resin composition layer was in contact with the inner layer substrate. The lamination was carried out by reducing the pressure for 30 seconds to adjust the atmospheric pressure to 13 hPa or less, and then pressure-bonding at 120 °C and a pressure of 0.74 MPa for 30 seconds. Subsequently, hot pressing was performed at 100 °C and a pressure of 0.5 MPa for 60 seconds. Then, the support was peeled off to expose the resin composition layer.

[0255] (4) Lamination of copper foil and curing of the resin composition layer: The treated surface of the CZ-treated copper foil was laminated on the exposed resin composition layer under the same conditions as the lamination of the resin sheet. Then, the resin composition layer was thermally cured under curing conditions of 200 °C for 90 minutes to form an insulating layer as a cured product layer. Thereby, an evaluation substrate having a layer structure of CZ-treated copper foil / insulating layer / inner layer substrate / insulating layer / CZ-treated copper foil was obtained.

[0256] This evaluation substrate was cut into small pieces of 100 mm × 30 mm. A cut was made using a cutter to surround a rectangular portion with a width of 10 mm and a length of 100 mm on the CZ-treated copper foil portion of the small piece. One end of the rectangular portion was peeled off and grasped with the gripper of a tensile testing machine, and the load [kgf / cm] when 35 mm was peeled off vertically at a speed of 50 mm / min at room temperature (normal temperature) was measured. The value of the load obtained as a result of this measurement is defined as the "adhesion strength". For the measurement, a tensile testing machine (Autocom universal testing machine "AC-50C-SL" manufactured by T.S.E. Co., Ltd.) was used, and the measurement was carried out in accordance with Japanese Industrial Standard JIS C6481. The measured adhesion strength was evaluated according to the following criteria.

[0257] Evaluation criteria for adhesion strength: "Excellent": The adhesion strength is 0.4 kgf / cm or more. "Good": The adhesion strength is 0.3 kgf / cm or more and less than 0.4 kgf / cm. "Poor": The adhesion strength is less than 0.3 kgf / cm.

[0258] <Results> The results of the above-described examples and comparative examples are shown in the following table. In the following table, the meanings of the abbreviations are as follows. NVC: Content of non-volatile components Df: Dielectric loss tangent

[0259]

Table 1

[0260]

Table 2

[0261]

Table 3

Claims

1. A resin composition comprising (A) a first epoxy resin represented by formula (A-1), (B) a second epoxy resin other than the first epoxy resin, (C) a curing agent, (D) a low-elasticity polymer, and (E) an inorganic filler. 【Chemical 1】 (In the above formula, R ａ１ each independently represents a hydrocarbon group having 1 to 8 carbon atoms; R ａ２ each independently represents a hydrogen atom, a dicyclopentenyl group represented by formula (A-2a) or formula (A-2b), a group represented by formula (A-3a), or a group represented by formula (A-3b); among at least two Rs ａ２ one represents a dicyclopentenyl group represented by formula (A-2a) or formula (A-2b), and the other represents a group represented by formula (A-3a) or formula (A-3b); R ａ３ each independently represents a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms; R ａ４ each independently represents a hydrogen atom or a group represented by the formula (A-3a); A ａ is a residue obtained by removing two Rs from formula (A-1), where the R ａ２ in the residue is a hydrogen atom, a dicyclopentenyl group represented by formula (A-2a) or formula (A-2b), or a group represented by formula (A-3a); ａ２ ​ i ａ represents an integer from 0 to 2; n ａ represents the number of repetitions, and its average value is a number from 0 to 5; p ａ indicates the number of repetitions, and the average value thereof is a number from 0.01 to 3.)

2. The resin composition according to claim 1, wherein the amount of (E) the inorganic filler is 50% by mass or more based on 100% by mass of the non-volatile components in the resin composition.

3. The resin composition according to claim 1, wherein (B) the second epoxy resin includes an epoxy resin containing an aromatic ring structure.

4. The resin composition according to claim 1, wherein (B) the second epoxy resin includes one or more selected from the group consisting of bisphenol A type epoxy resin, bisphenol F type epoxy resin, naphthalene type epoxy resin, bixylenol type epoxy resin, biphenyl type epoxy resin, naphthylene ether type epoxy resin, and phenolphthaleimide type epoxy resin.

5. The resin composition according to claim 1, wherein (D) the low-elasticity polymer has a weight average molecular weight greater than 5,000.

6. The resin composition according to claim 1, wherein (D) the low-elasticity polymer includes one or more selected from the group consisting of polybutadiene structure, polycarbonate structure, polyalkylene structure, polyalkyleneoxy structure, polysiloxane structure, poly(meth)acrylate structure, polyisoprene structure, polyisobutylene structure, and polystyrene structure.

7. The resin composition according to claim 1 for forming an insulating layer.

8. A resin sheet comprising a support and a resin composition layer provided on the support, wherein the resin composition layer contains the resin composition according to any one of claims 1 to 7.

9. A cured product of the resin composition according to any one of claims 1 to 7.

10. A circuit board comprising a cured product of the resin composition according to any one of claims 1 to 7.

11. A semiconductor device comprising the circuit board according to claim 10.

Images