Resin composition

Abstract

To provide a resin composition capable of forming an insulating layer which has a low dielectric loss tangent at a high temperature and a high frequency and has excellent adhesion to a conductor layer after HAST.SOLUTION: The resin composition contains (A) a specific epoxy resin, (B) a maleimide resin, and (C) an inorganic filler. The amount of the maleimide resin (B) is 2 mass% or more and 30 mass% or less based on 100 mass% of a resin component in the resin composition. The amount of the inorganic filler (C) is 65 mass% or more based on 100 mass% of a nonvolatile component in the resin composition.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 method for manufacturing 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 of, for example, a cured product of a resin composition. As a specific example, an insulating layer containing a cured product of a resin composition is formed by forming a resin composition layer containing a 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 high-speed communication such as the fifth-generation mobile communication system (5G), it is required to suppress transmission loss when operating in a high-frequency environment. In addition, the circuit board may become hot due to the heat generation of the semiconductor chip. Therefore, the present inventor has attempted to develop an insulating layer capable of reducing the dielectric tangent at high temperature and high frequency.

[0005] However, according to the study by the present inventors, it has been found that an insulating layer with a low dielectric tangent at high temperature and high frequency is inferior in adhesion to the conductor layer. Specifically, it is as follows. Generally, the insulating layer may be formed to be joined to the conductor layer, and in order to improve the reliability of the circuit board, it is desirable that the adhesion between the insulating layer and the conductor layer is high. In particular, from the viewpoint of achieving high reliability over a long period of time and realizing a long life of the circuit board, it is desirable that the adhesion between the insulating layer and the conductor layer is excellent after HAST (High Accelerated Stress Test; accelerated environmental test). However, the insulating layer with a low dielectric tangent at high temperature and high frequency tended to be inferior in adhesion after HAST.

[0006] The present invention has been devised in view of the above problems, and provides a resin composition capable of forming an insulating layer having a low dielectric tangent at high temperature and high frequency and excellent adhesion to the conductor layer after HAST; 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

[0007] The present inventors have intensively studied to solve the above problems. As a result, the present inventors have found that a resin composition containing a combination of a specific epoxy resin, a maleimide resin in a specific range of amounts, and an inorganic filler in a specific range of amounts can solve the above problems, and have completed the present invention. That is, the present invention includes the following.

[0008] <1> A resin composition containing (A) an epoxy resin represented by formula (A-1), (B) a maleimide resin, and (C) an inorganic filler, wherein the amount of (B) the maleimide resin is 2% by mass or more and 30% by mass or less based on 100% by mass of the resin components in the resin composition, the amount of (C) the inorganic filler is 65% by mass or more based on 100% by mass of the non-volatile components in the resin composition.

Chemical formula

Advantages of the Invention

[0009] According to the present invention, there can be provided a resin composition capable of forming an insulating layer having a low dielectric tangent at high temperature and high frequency and excellent adhesion to a conductor layer after HAST; 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

[0010] 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.

[0011] In this specification, the "dielectric constant" means the "relative dielectric constant" unless otherwise specified.

[0012] In this specification, the term "optionally having a substituent" for a compound or a group means both the case where the hydrogen atom of the compound or the group is not substituted with a substituent and the case where some or all of the hydrogen atoms of the compound or the group are substituted with a substituent.

[0013] <Overview of the Resin Composition> The resin composition according to one embodiment of the present invention contains, in combination, (A) an epoxy resin represented by formula (A-1), a maleimide resin (B) in a specific range of amounts, and an inorganic filler (C) in a specific range of amounts. In the following description, the “(A) epoxy resin represented by formula (A-1)” may be referred to as “(A) specific epoxy resin”.

[0014] [Chemical formula]

[0015] (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 of 0 to 2; n a represents the number of repetitions, and the average value thereof is a number from 0 to 5; p a represents the number of repetitions, and the average value thereof is a number from 0.01 to 3. *(Asterisk) represents the bonding site.)

[0016] According to the above resin composition, an insulating layer with a low dielectric tangent at high temperature and high frequency and excellent adhesion to the conductor layer after HAST can be formed. Further, according to this resin composition, generally, it is possible to lower the relative permittivity of the insulating layer, to improve the adhesion between the conductor layer before HAST and the insulating layer, to improve the smear removability of the insulating layer, to improve the crack resistance of the insulating layer, and to increase the glass transition temperature of the insulating layer.

[0017] The inventor speculates on the mechanism by which the excellent effects as described above are obtained as follows. However, the technical scope of the present invention is not limited by the following mechanism.

[0018] (A) The specific epoxy resin contains a glycidyloxy group bonded to a benzene ring in the main chain. This glycidyloxy group can move freely with respect to the main chain as can be understood from the molecular skeleton. Then, the glycidyloxy group can easily enter between other molecules in the resin composition and can prevent the interaction between those molecules. Therefore, as a result of preventing the interaction between polar groups, it is possible to suppress the aggregation of polar sites and the occurrence of molecular orientation at a minute level due to the interaction between polar groups, so that it is possible to suppress the occurrence of polarization bias in the entire resin composition. Therefore, since the polarity of the resin composition and its cured product can be reduced, the dielectric tangent of the insulating layer containing the cured product can be lowered, and usually the relative permittivity can also be lowered.

[0019] In addition, in such a (A) specific epoxy resin, since the glycidyloxy group reduces the intermolecular interaction, small water molecules tend to easily penetrate between the molecules of the cured product of the resin composition containing the (A) specific epoxy resin. Therefore, when the cured product is placed in a high-temperature and high-humidity environment, generally, the cured product may deteriorate due to hydrolysis caused by the penetration of water vapor, resulting in a significant decrease in adhesion. On the other hand, the resin composition according to the present embodiment uses a (B) maleimide resin. The (B) maleimide resin can cause radical polymerization to form a carbon-carbon bond. This carbon-carbon bond is superior in resistance to hydrolysis compared to bonds such as ester bonds formed by the reaction of epoxy groups. Further, since the (B) maleimide resin contains heteroatoms such as oxygen atoms and nitrogen atoms, due to the action of these heteroatoms, even under conditions where the reduction of the interaction by the (A) specific epoxy resin occurs, the cured product of the resin composition can exhibit high affinity for inorganic materials such as metals. Therefore, according to the resin composition of the present embodiment, since an insulating layer can be formed by a cured product having high resistance to water vapor and high affinity for inorganic materials, the adhesion between the conductor layer and the insulating layer after HAST can be improved. Furthermore, since the improvement in adhesion due to the action of the above-mentioned heteroatoms can be exhibited even before HAST, according to the resin composition of the present embodiment, usually, the adhesion between the conductor layer and the insulating layer before HAST can also be improved.

[0020] Furthermore, the glycidyloxy groups of the (A) specific epoxy resin react during curing to form a crosslinked structure, and this crosslinked structure can move more freely compared to the main chain portion of the (A) specific epoxy resin. Therefore, the crosslinked structure derived from the glycidyloxy groups can move to relieve stress, so the toughness of the cured product can be enhanced. Thus, delamination due to the destruction of the insulating layer can be suppressed. The ability to suppress delamination in this way is also considered to be one of the reasons why the insulating layer according to this embodiment can exhibit excellent adhesion. However, if there is an excess of the (B) maleimide resin, the crosslinked structure derived from the glycidyloxy groups will be relatively reduced, and the function of relieving stress will be insufficient, which may instead cause a reduction in adhesion. Therefore, the amount of the (B) maleimide resin is required to be within an appropriate range.

[0021] Also, as described above, since the (A) specific epoxy resin has glycidyloxy groups that reduce intermolecular interactions, the components of the swelling liquid and the oxidizing agent solution used in the desmear treatment for removing smears are likely to penetrate into the cured product of the resin composition. In addition, the carbon-carbon bonds formed by the radical polymerization of the (B) maleimide resin are susceptible to oxidation by the oxidizing agent. Therefore, usually, the insulating layer containing the cured product can have excellent smear removability.

[0022] Furthermore, as described above, the crosslinked structure derived from the glycidyloxy groups of the (A) specific epoxy resin can move to relieve stress, so the resistance of the cured product of the resin composition to stress can be enhanced. Therefore, the generation of cracks due to stress can be suppressed, and an insulating layer with excellent crack resistance can be formed.

[0023] <(A) specific epoxy resin> The resin composition according to this embodiment contains the (A) specific epoxy resin as the (A) component. The (A) specific epoxy resin is represented by the formula (A-1).

[0024]

Chemical formula

[0025] In 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. The alkyl group in R a1 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. Examples of the aryl group in R a1 include a phenyl group, a tolyl group, a xylyl group, an ethylphenyl group, and the like. Examples of the aralkyl group in R a1 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. When the specific epoxy resin (A) 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, meta, and para positions, but the ortho position is preferred.

[0026] In formula (A-1), R a2 each 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).

[0027] The dicyclopentenyl group is a group derived from dicyclopentadiene and is represented by formula (A-2a) or formula (A-2b). (A) When a specific epoxy resin contains a plurality of dicyclopentenyl groups in one molecule, these dicyclopentenyl groups may be the same or different.

[0028]

Chemical formula

[0029] The group represented by formula (A-3a) or formula (A-3b) is as follows.

[0030]

Chemical formula

[0031] 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; and still more preferably a hydrogen atom or an ethyl group. (A) When a specific epoxy resin contains a plurality of R a3 in one molecule, these 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. Also, 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 position, meta position, and para position, but the meta position and para position are preferred.

[0032] In formula (A-3b), R a3 has the same meaning as R a3 in formula (A-3a).

[0033] In formula (A-3b), A a represents a divalent residue obtained by removing two Rs from formula (A-1). R in this divalent residue a2 represents a hydrogen atom, a dicyclopentenyl group represented by formula (A-2a) or formula (A-2b), or a group represented by formula (A-3a). (A) When the specific epoxy resin contains a plurality of As in one molecule, those As a2 may be the same or different. a a

[0034] In formula (A-3b), each R a4 independently represents a hydrogen atom or a group represented by formula (A-3a). (A) When the specific epoxy resin contains a plurality of Rs in one molecule, those Rs a4 a4 may be the same or different.

[0035] In formula (A-3b), p a represents a number of 0 or more representing the number of repetitions. 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.

[0036] 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.

[0037] In formula (A-1), n a represents a number of 0 or more representing the number of repetitions. 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.

[0038] ​​​(A) The specific 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.

[0039] [Chemical formula]

[0040] (In the above formula, R a5 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-3c); among at least two R a5 , 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-3c); A a1 is the residue obtained by removing two R a5 from formula (A-4), and R a5 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); other symbols are as described above. * represents the bonding site.)

[0041] (A) The epoxy equivalent of the specific epoxy resin is preferably 200 g / eq. or more, more preferably 250 g / eq. or more, still more preferably 300 g / eq. or more, and even more preferably 350 g / eq. or more, and is preferably 4,000 g / eq. or less, more preferably 2,000 g / eq. or less, still more preferably 1,000 g / eq. or less, and even more preferably 500 g / eq. or less. The epoxy equivalent represents the mass of the resin per equivalent of epoxy groups. This epoxy equivalent can be measured according to JIS K7236.

[0042] When GPC (gel permeation chromatography) measurement is performed, as the composition of the (A) specific epoxy resin, in formula (A-1), preferably, na =0 body is 20 area % or less, n a =1 body is 40 area % - 90 area %, n a =Two or more bodies are in the range of 0 area % - 60 area %.

[0043] (A) The total chlorine content of the specific epoxy resin is preferably 2000 ppm or less, more preferably 1500 ppm or less.

[0044] (A) The melt viscosity of the specific epoxy resin at 150 °C is preferably 1.0 Pa·s or less, more preferably 0.7 Pa·s or less, and even 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.

[0045] (A) The specific epoxy resin may be used alone or in combination of two or more.

[0046] (A) The amount of the specific epoxy resin is preferably 1 mass % or more, more preferably 2 mass % or more, and even more preferably 4 mass % or more, and preferably 30 mass % or less, more preferably 20 mass % or less, and even more preferably 10 mass % or less, based on 100 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 in the resin composition excluding (I) the solvent. When the amount of the (A) specific epoxy resin is within the above range, an insulating layer with particularly low dielectric tangent at high temperature and high frequency and particularly excellent adhesion to the conductor layer after HAST can be formed. Also, usually, the relative permittivity, adhesion before HAST, smear removal property, crack resistance, and glass transition temperature can be made particularly good.

[0047] (A) The amount of the specific epoxy 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 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 components in the resin composition. Unless otherwise specified, the resin components in the resin composition refer to the components excluding (C) the inorganic filler among the non-volatile components in the resin composition. When the amount of the (A) specific epoxy resin is within the above range, an insulating layer with particularly low dielectric tangent at high temperature and high frequency and particularly excellent adhesion to the conductor layer after HAST can be formed. Also, usually, the relative permittivity, adhesion before HAST, smear removability, crack resistance, and glass transition temperature can be made particularly good.

[0048] As described later, the resin composition may contain an (A') arbitrary epoxy resin in combination with the (A) specific epoxy resin. At this time, the amount of the (A) specific epoxy resin is preferably 30% by mass or more, more preferably 40% by mass or more, still more preferably 50% by mass or more, and usually 100% by mass or less, based on 100% by mass of the total amount of the epoxy resins including the (A) specific epoxy resin and the (A') arbitrary epoxy resin. When the amount of the (A) specific epoxy resin is within the above range, an insulating layer with particularly low dielectric tangent at high temperature and high frequency and particularly excellent adhesion to the conductor layer after HAST can be formed. Also, usually, the relative permittivity, adhesion before HAST, smear removability, crack resistance, and glass transition temperature can be made particularly good.

[0049] The total amount of the epoxy resins including the (A) specific epoxy resin and the (A') arbitrary epoxy resin is preferably 1% by mass or more, more preferably 2% by mass or more, still more preferably 4% by mass or more, and preferably 30% by mass or less, more preferably 20% by mass or less, still more preferably 15% by mass or less, based on 100% by mass of the non-volatile components in the resin composition. When the total amount of the epoxy resin is within the above range, an insulating layer with particularly low dielectric tangent at high temperature and high frequency and particularly excellent adhesion to the conductor layer after HAST can be formed. Also, usually, the relative permittivity, adhesion before HAST, smear removability, crack resistance, and glass transition temperature can be made particularly good.

[0050] (A) The total amount of the specific epoxy resin and (A') any epoxy resin contained in the epoxy resin is preferably 5% by mass or more, more preferably 10% by mass or more, still more preferably 20% by mass or more, and preferably 70% by mass or less, more preferably 60% by mass or less, still more preferably 50% by mass or less, based on 100% by mass of the resin component in the resin composition. When the total amount of the epoxy resin is within the above range, an insulating layer having a particularly low dielectric tangent at high temperature and high frequency and particularly excellent adhesion to the conductor layer after HAST can be formed. Also, usually, the relative dielectric constant, adhesion before HAST, smear removability, crack resistance, and glass transition temperature can be made particularly good.

[0051] <(B) Maleimide resin> The resin composition according to the present embodiment contains (B) maleimide resin as the component (B). The (B) maleimide resin represents a resin containing one or more, preferably two or more maleimide groups (2,5-dihydro-2,5-dioxo-1H-pyrrol-1-yl groups) in one molecule. The (B) maleimide resin does not include those corresponding to the above-described component (A).

[0052] Examples of the (B) maleimide resin include an aromatic maleimide resin having a maleimide group directly bonded to an aromatic ring and an aliphatic maleimide resin having a maleimide group directly bonded to an aliphatic group. The (B) maleimide resin may contain only an aromatic maleimide resin, may contain only an aliphatic maleimide resin, or may contain a combination of an aromatic maleimide resin and an aliphatic maleimide resin. Among them, from the viewpoint of obtaining a cured product having a high glass transition temperature, the (B) maleimide resin preferably contains an aromatic maleimide resin, and more preferably contains only an aromatic maleimide resin.

[0053] Further, the (B) maleimide resin preferably contains a specific molecular skeleton. Preferred molecular skeletons include, for example, a biphenyl skeleton and an alicyclic skeleton. According to the (B) maleimide resin containing these molecular skeletons, properties such as dielectric loss tangent, relative permittivity, adhesion, smear removability, and crack resistance can be made particularly good. Among the alicyclic skeletons, the maleimide resin containing an indane skeleton can particularly well improve the above properties because of its excellent compatibility.

[0054] Preferable examples of the (B) maleimide resin include maleimide resins containing a partial structure represented by the following formula (B-1). Usually, the maleimide resin containing the partial structure represented by the formula (B-1) is an aliphatic maleimide resin. The number of maleimide groups that the maleimide resin containing the partial structure represented by the formula (B-1) has in one molecule is preferably 2 or more, and more preferably 2.

[0055] [Chemical formula]

[0056] (In formula (B-1), ring B b represents an aliphatic hydrocarbon ring which may have a substituent; i b and j b each independently represent 0 or an integer of 1 or more, and the sum of i b and j b is 6 or more; * represents a bonding site.)

[0057] In formula (B-1), ring B b represents an aliphatic hydrocarbon ring which may have a substituent. The aliphatic hydrocarbon ring may be a saturated aliphatic hydrocarbon ring or an unsaturated aliphatic hydrocarbon ring. Further, the aliphatic hydrocarbon ring may be a monocyclic aliphatic hydrocarbon ring having one ring or a polycyclic aliphatic hydrocarbon ring having a plurality of rings. The number of carbon atoms of the aliphatic hydrocarbon ring is preferably 4 or more, more preferably 5 or more, preferably 14 or less, more preferably 10 or less, and still more preferably 6 or less.

[0058] Ring B b Among them, the aliphatic hydrocarbon ring is preferably a monocyclic aliphatic hydrocarbon ring, and more preferably a monocyclic saturated aliphatic hydrocarbon ring. Examples of the monocyclic saturated aliphatic hydrocarbon ring include monocycloalkane rings such as cyclobutane ring, cyclopentane ring, cyclohexane ring, cycloheptane ring, and cyclooctane ring, and the cyclohexane ring is preferred.

[0059] Ring B b Examples of the substituent that the aliphatic hydrocarbon ring of Ring B may have include, for example, halogen atom, alkyl group, alkenyl group, aryl group, aralkyl group, alkyl-oxy group, alkenyl-oxy group, aryl-oxy group, aralkyl-oxy group, etc. Among them, the alkyl group and the alkenyl group are preferred, and the alkyl group is more preferred.

[0060] Examples of the halogen atom include fluorine atom, chlorine atom, bromine atom, and iodine atom.

[0061] The alkyl group can be a linear, branched or cyclic monovalent aliphatic saturated hydrocarbon group. The number of carbon atoms of the alkyl group is preferably 1 to 14, more preferably 1 to 6, and still more preferably 1 to 3. Examples of the alkyl group include methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, isopentyl group, sec-pentyl group, neopentyl group, tert-pentyl group, hexyl group, isohexyl group, heptyl group, isoheptyl group, octyl group, isooctyl group, tert-octyl group, cyclopentyl group, cyclohexyl group, cyclohexylmethyl group, etc.

[0062] An alkenyl group can be a linear, branched or cyclic monovalent aliphatic unsaturated hydrocarbon group having at least one carbon-carbon double bond. The number of carbon atoms in the alkenyl group is preferably 2 to 14, more preferably 2 to 6, still more preferably 2 or 3. Examples of the alkenyl group include a vinyl group, a propenyl group (allyl group, 1-propenyl group, isopropenyl group), a butenyl group (1-butenyl group, crotyl group, methallyl group, isocrotyl group, etc.), a pentenyl group (1-pentenyl group, etc.), a hexenyl group (1-hexenyl group, etc.), a heptenyl group (1-heptenyl group, etc.), an octenyl group (1-octenyl group, etc.), a cyclopentenyl group (2-cyclopentenyl group, etc.), a cyclohexenyl group (3-cyclohexenyl group), and the like.

[0063] An aryl group can be a monovalent aromatic hydrocarbon group formed by removing one hydrogen atom from an aromatic carbocyclic ring. The number of carbon atoms in the aryl group is preferably 6 to 14, more preferably 6 to 10. Examples of the aryl group include a phenyl group, a 1-naphthyl group, a 2-naphthyl group, and the like.

[0064] An aralkyl group can be an alkyl group substituted with one or more (preferably one) aryl groups. The number of carbon atoms in the aralkyl group is preferably 7 to 15, more preferably 7 to 11. Examples of the aralkyl group include a benzyl group, a phenethyl group, a hydrocinnamyl group, an α-methylbenzyl group, an α-cumyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, and the like.

[0065] In formula (B-1), i b and j b each independently represent an integer of 0 or 1 or more. Also, the sum of i b and j b is usually 6 or more, preferably 8 or more, more preferably 10 or more. i b and j b are preferably integers from 0 to 20, more preferably integers from 1 to 20, still more preferably integers from 5 to 10. i b and j bmay be the same or different. Among them, i b and j b is particularly preferably 8.

[0066] Examples of the maleimide resin containing the partial structure represented by the formula (B-1) include maleimide resins represented by the following formula (B-2).

[0067] [Chemical formula]

[0068] (In the formula (B-2), R b10 each independently represents a substituent; ring C b each independently represents an aromatic ring which may have a substituent; D b1 and D b2 each independently represents a single bond, -C(R x )2-, -O-, -CO-, -S-, -SO-, -SO2-, -CONH-, -NHCO-, -COO-, or -OCO-; R x each independently represents a hydrogen atom or an alkyl group; c b each independently represents 0 or 1; d b each independently represents 0 or an integer of 1 or more; e b each independently represents 0, 1, or 2; n b represents 0 or an integer of 1 or more; other symbols are as described above. The c b units, d b units, and n b units may be the same or different for each unit. )

[0069] In the formula (B-2), R b10 each independently represents a substituent. Examples of the substituent represented by R b10 include, for example, a halogen atom, an alkyl group, an alkenyl group, an aryl group, an aralkyl group, an alkyl-oxy group, an alkenyl-oxy group, an aryl-oxy group, an aralkyl-oxy group, and the like.

[0070] In formula (B-2), ring C b each independently represents an aromatic ring which may have a substituent. The aromatic ring can be a ring that follows Hückel's rule where the number of electrons contained in the π electron system on the ring is 4p + 2 (p is a natural number). The aromatic ring can be an aromatic carbon ring having only carbon atoms as ring-constituting atoms; or an aromatic heterocyclic ring having, in addition to carbon atoms, heteroatoms such as oxygen atoms, nitrogen atoms, sulfur atoms, etc. as ring-constituting atoms, but an aromatic carbon ring is preferred. The aromatic ring is preferably a 5- to 14-membered aromatic ring, more preferably a 6- to 14-membered aromatic ring, and even more preferably a 6- to 10-membered aromatic ring. Examples of the aromatic ring include a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, etc., more preferably a benzene ring or a naphthalene ring, and even more preferably a benzene ring.

[0071] Ring C b Examples of the substituent that the aromatic ring of may have include a halogen atom, an alkyl group, an alkenyl group, an aryl group, an aralkyl group, an alkyl-oxy group, an alkenyl-oxy group, an aryl-oxy group, an aralkyl-oxy group, etc. Among them, an alkyl group is preferred.

[0072] In formula (B-2), D b1 and D b2 each independently represents a single bond, -C(R x )2-, -O-, -CO-, -S-, -SO-, -SO2-, -CONH-, -NHCO-, -COO-, or -OCO-, preferably a single bond, -C(R x )2-, or -O-, and more preferably -O-. R x each independently represents a hydrogen atom or an alkyl group, preferably a hydrogen atom or a methyl group.

[0073] In formula (B-2), c b each independently represents 0 or 1, preferably 1.

[0074] In formula (B-2), d bEach independently represents an integer of 0 or 1 or more, preferably 0, 1, 2 or 3, more preferably 0, 1 or 2, and still more preferably 0.

[0075] In formula (B-2), e b Each independently represents 0, 1 or 2, preferably 0.

[0076] In formula (B-2), n b represents an integer of 0 or 1 or more, preferably 0.

[0077] Examples of the partial structure represented by the following formula (B-3) contained in formula (B-2) include partial structures represented by formulas (b-1) to (b-3) described later.

[0078]

Chemical formula

[0079]

Chemical formula

[0080] (In the formula, * indicates a bonding site.)

[0081] Commercially available products of maleimide resins containing the partial structure represented by formula (B-1) include, for example, "BMI-689", "BMI-1500", "BMI-1700", "BMI-3000J" manufactured by Designer Molecules Inc.; "SLK-1500-T80" (compound of the following formula (b-4)), "SLK-6895-T90" (compound of formula (b-5)) manufactured by Shin-Etsu Chemical Co., Ltd., and the like.

[0082]

Chemical formula

[0083] (B) Another preferred example of the maleimide resin is the maleimide resin represented by the formula (B-4).

[0084]

Chemical formula

[0085] (In the formula (B-4), R b20 each independently represents a hydrogen atom or an alkyl group; ring E b , ring F b and ring G b each independently represents an aromatic ring which may have a substituent; Z b1 each independently represents a single bond, -C(R z )2-, -O-, -CO-, -S-, -SO-, -SO2-, -CONH-, or -NHCO-; R z each independently represents a hydrogen atom or an alkyl group; f b represents an integer of 1 or more; g b each independently represents 0 or 1; h b each independently represents 0, 1, 2, or 3. The f b units and the h b units may be the same or different for each unit.)

[0086] In the formula (B-4), R b20 each independently represents a hydrogen atom or an alkyl group, preferably a hydrogen atom or a methyl group, more preferably a hydrogen atom.

[0087] In the formula (B-4), ring E b , ring F b and ring G b each independently represents an aromatic ring which may have a substituent. Ring E b , ring F b and ring G bExamples of the substituent in [it] include, for example, a halogen atom, an alkyl group, an alkenyl group, an aryl group, an aralkyl group, an alkyl-oxy group, an alkenyl-oxy group, an aryl-oxy group, an aralkyl-oxy group, and the like. Ring E b , Ring F b and Ring G b are preferably benzene rings which may have a substituent, more preferably benzene rings which may be substituted with a group selected from an alkyl group and an aryl group, and still more preferably unsubstituted benzene rings.

[0088] In formula (B-4), Z b1 each independently represents a single bond, -C(R z )2-, -O-, -CO-, -S-, -SO-, -SO2-, -CONH-, or -NHCO-, and is preferably a single bond. R z each independently represents a hydrogen atom or an alkyl group, and is preferably a hydrogen atom or a methyl group.

[0089] In formula (B-4), f b represents an integer of 1 or more, and is preferably an integer of 1 to 10.

[0090] In formula (B-4), g b each independently represents 0 or 1, and is preferably 1.

[0091] In formula (B-4), h b each independently represents 0, 1, 2, or 3, is preferably 0, 1, or 2, more preferably 0 or 1, and still more preferably 1.

[0092] Examples of commercially available products of the maleimide resin represented by formula (B-4) include, for example, "MIR-3000-70MT", "MIR-5000-60T", etc. manufactured by Nippon Kayaku Co., Ltd.

[0093] (B) Still another preferred example of the maleimide resin includes the maleimide resin represented by formula (B-5).

[0094] [Chemical formula]

[0095] (In formula (B-5), R b30 each independently represents an alkyl group; ring H b and ring I b each independently represent an aromatic ring which may have a substituent; m b represents an integer of 1 or more. The m b units may be the same or different for each unit.)

[0096] In formula (B-5), R b30 each independently represents an alkyl group, preferably a methyl group.

[0097] In formula (B-5), ring H b each independently represents an aromatic ring which may have a substituent. Examples of the substituent in ring H b include, for example, a halogen atom, an alkyl group, an alkenyl group, an aryl group, an aralkyl group, an alkyl-oxy group, an alkenyl-oxy group, an aryl-oxy group, an aralkyl-oxy group, and the like. Ring H b is preferably a benzene ring which may have a substituent, more preferably a benzene ring which may be substituted with an alkyl group, and still more preferably a benzene ring substituted with an alkyl group.

[0098] In formula (B-5), ring I b each independently represents an aromatic ring which may have a substituent. Examples of the substituent in ring I b include, for example, a halogen atom, an alkyl group, an alkenyl group, an aryl group, an aralkyl group, an alkyl-oxy group, an alkenyl-oxy group, an aryl-oxy group, an aralkyl-oxy group, and the like. Ring I b is preferably a benzene ring which may have a substituent, more preferably a benzene ring which may be substituted with an alkyl group, and still more preferably an unsubstituted benzene ring.

[0099] In formula (B-5), m b represents an integer of 1 or more, preferably an integer of 1 to 20.

[0100] The maleimide resin represented by formula (B-5) can be produced, for example, using the method described in JP-A No. 2020-500211 of the Japan Institute of Invention and Innovation or a method analogous thereto.

[0101] (B) The maleimide group equivalent of the maleimide resin is preferably 30 g / eq. or more, more preferably 75 g / eq. or more, still more preferably 150 g / eq. or more, still more preferably 200 g / eq. or more, still more preferably 250 g / eq. or more, still more preferably 300 g / eq. or more, and preferably 2,500 g / eq. or less, more preferably 2,000 g / eq. or less, still more preferably 1,500 g / eq. or less, still more preferably 1,000 g / eq. or less, still more preferably 500 g / eq. or less. The maleimide group equivalent represents the mass of the resin per equivalent of the maleimide group.

[0102] (B) The weight average molecular weight of the maleimide resin is preferably 100 or more, more preferably 150 or more, still more preferably 200 or more, still more preferably 400 or more, still more preferably 500 or more, still more preferably 600 or more, and preferably 10,000 or less, more preferably 7,000 or less, still more preferably 5,000 or less, still more preferably 3,000 or less. The weight average molecular weight can be measured as a polystyrene equivalent value by gel permeation chromatography (GPC) method.

[0103] (B) The amount of the maleimide resin is usually 2% by mass or more, preferably 4% by mass or more, more preferably 6% by mass or more, and usually 30% by mass or less, preferably 25% by mass or less, 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 (B) maleimide resin is within the above range, an insulating layer with a low dielectric tangent at high temperature and high frequency and excellent adhesion to the conductor layer after HAST can be formed. Also, usually, it is possible to lower the relative dielectric constant of the insulating layer, improve the adhesion between the conductor layer before HAST and the insulating layer, improve the smear removability of the insulating layer, improve the crack resistance of the insulating layer, and increase the glass transition temperature of the insulating layer.

[0104] (B) The amount of the maleimide resin is preferably 0.1% by mass or more, more preferably 1% by mass or more, still more preferably 1.5% by mass or more, and preferably 20% by mass or less, more preferably 10% by mass or less, particularly preferably 5% by mass or less, based on 100% by mass of the non-volatile components in the resin composition. When the amount of the (B) maleimide resin is within the above range, an insulating layer with a particularly low dielectric tangent at high temperature and high frequency and particularly excellent adhesion to the conductor layer after HAST can be formed. Also, usually, the relative dielectric constant, the adhesion before HAST, the smear removability, the crack resistance, and the glass transition temperature can be made particularly good.

[0105] (A) The total amount of the specific epoxy resin and (B) the maleimide resin is preferably 7% by mass or more, more preferably 15% by mass or more, still more preferably 20% by mass or more, and preferably 70% by mass or less, more preferably 60% by mass or less, still more preferably 50% by mass or less, based on 100% by mass of the resin components in the resin composition. When the total amount of the (A) specific epoxy resin and (B) the maleimide resin is within the above range, an insulating layer with a particularly low dielectric tangent at high temperature and high frequency and particularly excellent adhesion to the conductor layer after HAST can be formed. Also, usually, the relative dielectric constant, the adhesion before HAST, the smear removability, the crack resistance, and the glass transition temperature can be made particularly good.

[0106] (A) Specific epoxy resin and (B) maleimide resin preferably have a mass ratio ((amount of (B) maleimide resin) / (amount of (A) specific epoxy resin)) within a specific range. Specifically, the mass ratio ((amount of (B) maleimide resin) / (amount of (A) specific epoxy resin)) is preferably 0.1 or more, more preferably 0.15 or more, still more preferably 0.2 or more, and preferably 1.0 or less, more preferably 0.8 or less, still more preferably 0.6 or less. When the mass ratio ((amount of (B) maleimide resin) / (amount of (A) specific epoxy resin)) is within the above range, an insulating layer with particularly low dielectric tangent at high temperature and high frequency and particularly excellent adhesion to the conductor layer after HAST can be formed. Also, usually, the relative dielectric constant, adhesion before HAST, smear removability, crack resistance, and glass transition temperature can be made particularly good.

[0107] (A) The total amount of epoxy resin containing (A) specific epoxy resin and (A') any epoxy resin and (B) maleimide resin preferably have a mass ratio ((amount of (B) maleimide resin) / (total amount of epoxy resin)) within a specific range. Specifically, the mass ratio ((amount of (B) maleimide resin) / (total amount of epoxy resin)) is preferably 0.05 or more, more preferably 0.1 or more, still more preferably 0.15 or more, and preferably 1.0 or less, more preferably 0.6 or less, still more preferably 0.4 or less. When the mass ratio ((amount of (B) maleimide resin) / (total amount of epoxy resin)) is within the above range, an insulating layer with particularly low dielectric tangent at high temperature and high frequency and particularly excellent adhesion to the conductor layer after HAST can be formed. Also, usually, the relative dielectric constant, adhesion before HAST, smear removability, crack resistance, and glass transition temperature can be made particularly good.

[0108] <(C) Inorganic filler> The resin composition according to this embodiment contains (C) inorganic filler as the (C) component. The (C) inorganic filler is particles of an inorganic material. Therefore, the (C) 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.

[0109] (C) As the inorganic material for forming the inorganic filler, an inorganic compound is usually used. (C) Examples of the material for the 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, etc. Among these, silica and alumina are preferred, and silica is particularly preferred. Therefore, (C) the inorganic filler preferably contains silica and may contain only silica. Examples of silica include amorphous silica, fused silica, crystalline silica, synthetic silica, hollow silica, etc. Also, spherical silica is preferred as the silica. (C) The inorganic filler may be used alone or in combination of two or more kinds.

[0110] (C) Examples of commercially available products of the inorganic filler 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; "Cellspheres", "MGH-005" manufactured by Taiheiyo Cement Corporation; "Esferique", "BA-1" manufactured by JGC Catalysts & Chemicals Ltd., etc.

[0111] (C) 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 still more preferably 1 μm or less.

[0112] (C) The average particle size of the inorganic filler can be measured by a laser diffraction / scattering method based on the Mie scattering theory. Specifically, a particle size distribution of the inorganic filler is created on a volume basis by a laser diffraction / scattering type particle size distribution measuring device, and the median diameter thereof is taken as the average particle size for measurement. 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 in a flow cell method using a laser diffraction type particle size distribution measuring device with the wavelengths of the light sources used being blue and red, 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.

[0113] (C) 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, and preferably 100 m 2 / g or less, more preferably 70 m 2 / g or less, still more preferably 50 m 2 / g or less, particularly preferably 40 m 2 / g or less. (C) The specific surface area of the inorganic filler can be measured by adsorbing nitrogen gas onto 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 multipoint method.

[0114] (C) 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 types.

[0115] Examples of commercially available surface treatment agents include "KBM403" (3-glycidoxypropyltrimethoxysilane), "KBM803" (3-mercaptopropyltrimethoxysilane), "KBE903" (3-aminopropyltriethoxysilane), "KBM573" (N-phenyl-3-aminopropyltrimethoxysilane), "SZ-31" (hexamethyldisilazane), "KBM103" (phenyltrimethoxysilane), "KBM-4803" (long-chain epoxy type silane coupling agent), "KBM-7103" (3,3,3-trifluoropropyltrimethoxysilane), etc., all manufactured by Shin-Etsu Chemical Co., Ltd.

[0116] From the viewpoint 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 0.2% to 3% by mass of the surface treatment agent, and even more preferably 0.3% to 2% by mass of the surface treatment agent.

[0117] 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 viewpoint 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, and more preferably 0.1 mg / m 2The above is more preferable, 0.2 mg / m 2 The above is even more preferable. On the other hand, from the viewpoint of preventing an increase in the melt viscosity of the resin composition layer, 1.0 mg / m 2 or less is preferable, 0.8 mg / m 2 or less is more preferable, and 0.5 mg / m 2 or less is even more preferable.

[0118] (C) 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 a 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. can be used.

[0119] (C) The amount of the inorganic filler is usually 65% by mass or more, preferably 68% by mass or more, more preferably 70% by mass or more, preferably 90% by mass or less, more preferably 85% by mass or less, and even more preferably 80% by mass or less based on 100% by mass of the non-volatile components in the resin composition. As described above, when (C) the inorganic filler is large, the resin component is relatively small, so generally the adhesion between the insulating layer and the conductor layer tends to be low, and particularly the adhesion after HAST tends to decrease significantly. On the other hand, according to the resin composition according to the present embodiment, an insulating layer excellent in adhesion after HAST can be obtained even if (C) the inorganic filler is large. Further, when the amount of (C) the inorganic filler is within the above range, usually, the dielectric loss tangent, relative permittivity, adhesion before HAST, smear removability, crack resistance, and glass transition temperature can be made particularly good.

[0120] (A) Specific epoxy resin, (B) maleimide resin, and (C) total amount of inorganic filler are preferably 70% by mass or more, more preferably 75% by mass or more, still more preferably 80% by mass or more, and preferably 95% by mass or less, more preferably 90% by mass or less, still more preferably 85% by mass or less with respect to 100% by mass of non-volatile components in the resin composition.

[0121] <(A’) Any epoxy resin> The resin composition according to this embodiment may contain, as an optional component, (A’) any epoxy resin other than the (A) specific epoxy resin. As the (A’) any epoxy resin as the (A’) component, a curable resin having an epoxy group and not corresponding to the (A) specific epoxy resin can be used. Therefore, the (A’) any epoxy resin does not include those corresponding to the above-mentioned (A) to (C) components. The (A’) any epoxy resin may be used alone or in combination of two or more.

[0122] Examples of the (A’) any epoxy resin include, for example, bixylenol type epoxy resin, 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, glycidylamine type epoxy resin, glycidyl ester type epoxy resin, cresol novolak type epoxy resin, phenol aralkyl type epoxy resin, biphenyl type epoxy resin, linear aliphatic epoxy resin, epoxy resin having a butadiene structure, alicyclic epoxy resin, heterocyclic epoxy resin, spiro ring-containing epoxy resin, cyclohexane type epoxy resin, cyclohexanedimethanol type epoxy resin, naphthylene ether type epoxy resin, trimethylol type epoxy resin, tetraphenylethane type epoxy resin, isocyanurate type epoxy resin, phenol phthalimide type epoxy resin, etc.

[0123] (A’) Any epoxy resin preferably contains an epoxy resin having an aromatic structure from the viewpoint of obtaining a cured product with excellent heat resistance. The aromatic structure is a chemical structure generally defined as aromatic, and includes polycyclic aromatics and aromatic heterocycles. Examples of the epoxy resin having 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, 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.

[0124] (A’) Any 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 components of any epoxy resin (A’), 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.

[0125] (A’) Any epoxy resin includes a liquid epoxy resin (hereinafter sometimes referred to as "liquid epoxy resin") that is liquid at a temperature of 20°C and a solid epoxy resin (hereinafter sometimes referred to as "solid epoxy resin") that is solid at a temperature of 20°C. (A’) Any epoxy resin may contain only a liquid epoxy resin, may contain only a solid epoxy resin, or may contain a combination of a liquid epoxy resin and a solid epoxy resin.

[0126] As the liquid epoxy resin, a liquid epoxy resin having two or more epoxy groups in one molecule is preferred. Preferred liquid epoxy resins include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AF type epoxy resin, naphthalene type epoxy resin, glycidyl ester type epoxy resin, glycidyl amine type epoxy resin, phenol novolac type epoxy resin, alicyclic epoxy resin having an ester skeleton, cyclohexane type epoxy resin, cyclohexanedimethanol type epoxy resin, and epoxy resin having a butadiene structure.

[0127] 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.

[0128] 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 bixylenol 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 phenolphthalimide type epoxy resin.

[0129] Specific examples of the solid epoxy resin include "HP4032H" (naphthalene-type epoxy resin) manufactured by DIC Corporation; "HP-4700" and "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" and "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" and "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.

[0130] (A’) When any 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.

[0131] (A’) The range of the epoxy equivalent of any 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.

[0132] (A’) The range of the weight average molecular weight (Mw) of any epoxy resin is preferably 100 to 5,000, more preferably 250 to 3,000, and still more preferably 400 to 1,500.

[0133] (A’) The amount of any epoxy 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 non-volatile components in the resin composition. When the amount of any epoxy resin is within the above range, an insulating layer with particularly low dielectric tangent at high temperature and high frequency and particularly excellent adhesion to the conductor layer after HAST can be formed. Also, usually, the relative permittivity, adhesion before HAST, smear removability, crack resistance, and glass transition temperature can be made particularly good.

[0134] (A’) The amount of any epoxy resin is preferably 1% by mass or more, more preferably 5% by mass or more, still more preferably 10% by mass or more, and preferably 40% by mass or less, more preferably 30% by mass or less, still more preferably 20% by mass or less, based on 100% by mass of the resin components in the resin composition. When the amount of any epoxy resin is within the above range, an insulating layer with a particularly low dielectric tangent at high temperature and high frequency and particularly excellent adhesion to the conductor layer after HAST can be formed. Also, usually, the relative permittivity, adhesion before HAST, smear removability, crack resistance, and glass transition temperature can be made particularly good.

[0135] <(D) Polymerizable unsaturated resin> The resin composition according to this embodiment may contain, as an optional component, a (D) polymerizable unsaturated resin other than the (B) maleimide resin. The (D) polymerizable unsaturated resin as the component (D) does not include those corresponding to the above-mentioned components (A) to (C) or component (A’). The (D) polymerizable unsaturated resin may be used alone or in combination of two or more.

[0136] As the (D) polymerizable unsaturated resin, a resin containing a non-aromatic carbon-carbon unsaturated bond can be used. Therefore, the (D) 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, etc. The (D) polymerizable unsaturated resin having these polymerizable unsaturated groups can usually react with the (B) maleimide resin or react with the (D) polymerizable unsaturated resins themselves by radical polymerization. The (D) polymerizable unsaturated resin preferably has two or more polymerizable unsaturated groups.

[0137] Examples of the (D) polymerizable unsaturated resin include (meth)acrylic-based polymerizable unsaturated resins, styrene-based polymerizable unsaturated resins, allyl-based polymerizable unsaturated resins, and the like.

[0138] (Meth)acrylic polymerizable unsaturated resins include resins having one or more, preferably two or more acryloyl groups and / or methacryloyl groups in one molecule. Examples of (meth)acrylic polymerizable unsaturated resins include low molecular weight (molecular weight less than 1000) aliphatic (meth)acrylate compounds 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 compounds 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 compounds 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) acrylate compounds such as (meth)acryl-modified polyphenylene ether resin, and the like.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" (methacryl-modified polyphenylene ether) manufactured by SABIC, etc.

[0139] As the styrenic 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 styrenic polymerizable unsaturated resin include low molecular weight (molecular weight less than 1000) styrenic compounds 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) styrenic compounds such as vinylbenzyl-modified polyphenylene ether resin and styrene-divinylbenzene copolymer; and the like. Among these styrenic polymerizable unsaturated resins, a resin containing a combination of monovinyl aromatic compound units and divinyl aromatic compound units is preferred. The monovinyl aromatic compound unit represents a structural unit having a structure formed by polymerizing a monovinyl compound such as styrene having an aromatic ring to which one vinyl group is directly bonded alone. The divinyl aromatic compound unit represents a structural unit having a structure formed by polymerizing a divinyl aromatic compound such as divinylbenzene having an aromatic ring to which two vinyl groups are directly bonded. Examples of such a preferred styrenic polymerizable unsaturated resin include the resin described in International Publication No. 2017 / 115813. Examples of commercially available products of the styrenic polymerizable unsaturated resin 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.

[0140] 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 compounds such as diallyl diphenate, triallyl trimellitate, diallyl phthalate, diallyl isophthalate, diallyl terephthalate, diallyl 2,6-naphthalenedicarboxylate, and diallyl 2,3-naphthalenedicarboxylate; allyl ester compounds of isocyanuric acid such as 1,3,5-triallyl isocyanurate and 1,3-diallyl-5-glycidyl isocyanurate; epoxy-containing aromatic allyl compounds such as 2,2-bis[3-allyl-4-(glycidyloxy)phenyl]propane; benzooxazine-containing aromatic allyl compounds such as bis[3-allyl-4-(3,4-dihydro-2H-1,3-benzoxazin-3-yl)phenyl]methane; ether-containing aromatic allyl compounds such as 1,3,5-triallyl ether benzene; and allyl silane compounds such as diallyl diphenyl silane. Among them, a resin having an allyl group at the terminal is preferred. Examples of commercially available products of the allyl-based polymerizable unsaturated resin include "TAIC" (1,3,5-triallyl isocyanurate) manufactured by Nippon Kasei Co., Ltd., "DAD" (diallyl diphenate) manufactured by Nissho Technofine Chemical Co., Ltd., "TRIAM-705" (triallyl trimellitate) manufactured by Fujifilm Wako Pure Chemical Corporation, the product name "DAND" (diallyl 2,3-naphthalenedicarboxylate) manufactured by Nissho Technofine 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.

[0141] (D) As the polymerizable unsaturated resin, a resin containing an active group capable of forming a bond by a reaction other than a radical reaction in combination with a polymerizable unsaturated group capable of a radical reaction may be used. Examples of such an active group include a phenolic hydroxyl group (a hydroxyl group directly bonded to an aromatic ring), an active ester group, and the like.

[0142] (D) The polymerizable unsaturated resin may include a resin containing an indane skeleton in the molecular skeleton. The polymerizable unsaturated resin containing an indane skeleton is usually excellent in compatibility with other resin components.

[0143] (D) The polymerizable unsaturated resin may include a resin containing a polyphenylene ether skeleton in the molecular skeleton.

[0144] (D) 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.

[0145] (D) 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, but may be, for example, 150 or more.

[0146] (D) 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 10% by mass or less, more preferably 5% by mass or less, still more preferably 3% by mass or less, based on 100% by mass of the non-volatile components in the resin composition. When the amount of the (D) polymerizable unsaturated resin is within the above range, an insulating layer having a particularly low dielectric tangent at high temperature and high frequency and particularly excellent adhesion to the conductor layer after HAST can be formed. Also, usually, the relative dielectric constant, adhesion before HAST, smear removability, crack resistance, and glass transition temperature can be made particularly good.

[0147] (D) The amount of the polymerizable unsaturated 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 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 resin components in the resin composition. When the amount of the (D) polymerizable unsaturated resin is within the above range, an insulating layer having a particularly low dielectric tangent at high temperature and high frequency and particularly excellent adhesion to the conductor layer after HAST can be formed. Also, usually, the relative dielectric constant, adhesion before HAST, smear removability, crack resistance, and glass transition temperature can be made particularly good.

[0148] <(E) Curing agent> The epoxy resins such as the (A) specific epoxy resin contained in the resin composition according to the present embodiment may react with each other to form a bond, or may react with the (E) curing agent to form a bond. Therefore, the resin composition may contain, as an optional component, an (E) curing agent that can react with the epoxy resin to cure the resin composition. The (E) curing agent as the (E) component does not include those corresponding to the above-described (A) to (D) components or (A') component. For example, under an appropriate catalyst, the (B) maleimide resin may react with the epoxy resin, but the (B) maleimide resin is not classified as the (E) curing agent. The (E) curing agent may be used alone or in combination of two or more.

[0149] (E) The curing agent preferably contains (E-1) an active ester-based resin. As the (E-1) active ester-based resin as the component (E-1), a resin having one or more, preferably two or more active ester groups in one molecule can be used. Since the (E-1) active ester-based resin does not generate polar groups such as hydroxyl groups by reaction with an epoxy resin, the polarity of the cured product can be lowered, and thus the dielectric loss tangent and relative dielectric constant of the insulating layer can be lowered. Further, conventionally, an insulating layer formed using the (E-1) active ester-based resin has tended to be inferior in smear removability, but according to the resin composition according to the present embodiment, usually, smear removability can be improved while using the (E-1) active ester-based resin.

[0150] As the (E-1) active ester-based resin, compounds having two or more highly reactive ester groups in one molecule, such as phenol esters, thiophenol esters, N-hydroxyamine esters, and esters of heterocyclic hydroxy compounds, are preferable.

[0151] (E-1) 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, etc. 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 compound, phenol novolak, etc. Here, the "dicyclopentadiene-type diphenol compound" refers to a diphenol compound obtained by condensing two molecules of phenol with one molecule of dicyclopentadiene.

[0152] Specifically, as the (E-1) 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 novolak, and an active ester resin containing a benzoylated product of phenol novolak 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.

[0153] 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.

[0154] (E-1) The active ester resin may be used alone or in combination of two or more.

[0155] (E-1) The number of active ester groups in the active ester-based resin is preferably 0.1 or more, more preferably 0.5 or more, still more preferably 1 or more, and preferably 10 or less, more preferably 7 or less, still more preferably 5 or less when the number of epoxy groups in (A) the specific epoxy resin is taken as 1. The "number of epoxy groups in (A) the specific 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 components of (A) the specific epoxy resin present in the resin composition by its epoxy equivalent. Also, the "number of active ester groups in (E-1) the active ester-based 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 components of (E-1) the active ester-based resin present in the resin composition by its active ester group equivalent. Further, the active ester group equivalent represents the mass of the resin per 1 equivalent of the active ester group.

[0156] (E-1) The number of active ester groups in the active ester-based resin is preferably 0.1 or more, more preferably 0.5 or more, still more preferably 1 or more, and preferably 6 or less, more preferably 4 or less, still more preferably 2 or less when the number of epoxy groups of all epoxy resins including (A) the specific epoxy resin and (A') any epoxy resin is taken as 1. The "number of epoxy groups of all epoxy resins" in the resin composition represents the total value obtained by summing up all the values obtained by dividing the mass of the non-volatile components of the epoxy resins present in the resin composition by their epoxy equivalents.

[0157] (E-1) The amount of the active ester-based resin is preferably 1% by mass or more, more preferably 3% by mass or more, still more preferably 6% by mass or more, and preferably 25% by mass or less, more preferably 20% by mass or less, 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 the (E-1) active ester-based resin is within the above range, an insulating layer with particularly low dielectric tangent at high temperature and high frequency and particularly excellent adhesion to the conductor layer after HAST can be formed. Also, usually, the relative permittivity, adhesion before HAST, smear removal property, crack resistance, and glass transition temperature can be made particularly good.

[0158] (E-1) The amount of the active ester-based resin is preferably 10% by mass or more, more preferably 20% by mass or more, still more preferably 30% 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 components in the resin composition. When the amount of the (E-1) active ester-based resin is within the above range, an insulating layer with a particularly low dielectric tangent at high temperature and high frequency and particularly excellent adhesion to the conductor layer after HAST can be formed. Also, usually, the relative permittivity, adhesion before HAST, smear removability, crack resistance, and glass transition temperature can be made particularly good.

[0159] (A) The total amount of the specific epoxy resin, (B) the maleimide resin, and (E-1) the active ester-based resin is preferably 30% by mass or more, more preferably 40% by mass or more, still more preferably 50% 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 resin components in the resin composition. When the total amount of the (A) specific epoxy resin, (B) the maleimide resin, and (E-1) the active ester-based resin is within the above range, an insulating layer with a particularly low dielectric tangent at high temperature and high frequency and particularly excellent adhesion to the conductor layer after HAST can be formed. Also, usually, the relative permittivity, adhesion before HAST, smear removability, crack resistance, and glass transition temperature can be made particularly good.

[0160] Preferable examples of the (E) curing agent other than the (E-1) active ester-based resin include phenolic resins, benzoxazine-based resins, cyanate ester-based resins, carbodiimide-based resins, acid anhydride-based resins, amine-based resins, and the like.

[0161] 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 preferable. Further, from the viewpoint of adhesion, a nitrogen-containing phenolic resin is preferable, and a phenolic resin containing a triazine skeleton is more preferable. Among them, from the viewpoint of highly satisfying heat resistance, water resistance, and adhesion, a phenolic novolak resin containing a triazine skeleton is preferable.

[0162] 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", etc. manufactured by Gunei Chemical Industry Co., Ltd.

[0163] As the benzoxazine resin, a resin having one or more, preferably two or more benzoxazine rings in one molecule can be used. Specific examples of the benzoxazine resin include "JBZ-OP100D", "ODA-BOZ" manufactured by JFE Chemical Corporation; "HFB2006M" manufactured by Showa Highpolymer Co., Ltd.; "P-d", "F-a", "ALP-d", etc. manufactured by Shikoku Kasei Kogyo Co., Ltd.

[0164] As the cyanate ester resin, a resin having one or more, preferably two or more cyanate groups in one molecule can be used. Examples of the cyanate ester resin include bifunctional cyanate ester 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-cyanate phenylmethane), bis(4-cyanate-3,5-dimethylphenyl)methane, 1,3-bis(4-cyanate phenyl-1-(methylethylidene))benzene, bis(4-cyanate phenyl)thioether, and bis(4-cyanate phenyl)ether; polyfunctional cyanate ester resins derived from phenol novolac and cresol novolac; prepolymers in which some of these cyanate ester resins are triazine-formed; and the like. Specific examples of the cyanate ester resin include "PT30" and "PT60" (phenol novolac type polyfunctional cyanate ester resin), "BA230", "BA230S75" (prepolymer in which part or all of bisphenol A dicyanate is triazine-formed and becomes a trimer), etc. manufactured by Lonza.

[0165] 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 Corporation.

[0166] 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, methylnadic anhydride, hydrogenated methylnadic 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.

[0167] 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 Chemical Co., Ltd., etc.

[0168] (E) The active group equivalent weight of the curing agent is preferably 50 g / eq. to 3,000 g / eq., more preferably 100 g / eq. to 1,000 g / eq., still more preferably 100 g / eq. to 500 g / eq., and particularly preferably 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 and represents the mass of the resin per equivalent of the phenolic hydroxyl group.

[0169] (E) 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 any epoxy resin (A’).

[0170] (E) When the epoxy group number of the specific epoxy resin (A) is taken as 1, the number of active groups of the curing agent (E) is preferably 0.1 or more, more preferably 1 or more, still more preferably 2 or more, and preferably 10 or less, more preferably 7 or less, still more preferably 5 or less. The “number of active groups of the curing agent (E)” 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 the curing agent (E) present in the resin composition by its active group equivalent weight.

[0171] (E) When the epoxy group number of all epoxy resins including the specific epoxy resin (A) and any epoxy resin (A’) is taken as 1, the number of active groups of the curing agent (E) is preferably 0.1 or more, more preferably 0.5 or more, still more preferably 1 or more, and preferably 10 or less, more preferably 6 or less, still more preferably 3 or less.

[0172] (E) The amount of the curing agent is preferably 1% by mass or more, more preferably 5% by mass or more, still more preferably 8% by mass or more, and preferably 25% by mass or less, more preferably 20% by mass or less, still more preferably 15% by mass or less based on 100% by mass of the non-volatile components in the resin composition.

[0173] (E) The amount of the curing agent is preferably 10% by mass or more, more preferably 20% by mass or more, still more preferably 30% by mass or more, and preferably 70% by mass or less, more preferably 60% by mass or less, still more preferably 50% by mass or less, based on 100% by mass of the resin component in the resin composition.

[0174] <(F) Curing accelerator> The resin composition according to the present embodiment may contain, as an optional component, (F) a curing accelerator. The (F) curing accelerator as the component (F) does not include those corresponding to the above-described components (A) to (E) or component (A'). The (F) curing accelerator can act as a catalyst for the reaction of epoxy resins such as (A) specific epoxy resin and (A') optional epoxy resin to promote the curing of the resin composition.

[0175] Examples of the (F) curing accelerator include phosphorus-based curing accelerators, urea-based curing accelerators, guanidine-based curing accelerators, imidazole-based curing accelerators, metal-based curing accelerators, amine-based curing accelerators, and the like. The (F) curing accelerator may be used alone or in combination of two or more.

[0176] 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. can be mentioned.;

[0177] 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], and the like.

[0178] 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, and the like.

[0179] Examples of imidazole-based curing accelerators include imidazole compounds such as 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 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.

[0180] Examples of the metal-based hardening accelerator include organometallic complexes or organometallic salts of metals such as cobalt, copper, zinc, iron, nickel, manganese, and tin. Specific examples of the 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 the organometallic salts include zinc octylate, tin octylate, zinc naphthenate, cobalt naphthenate, tin stearate, and zinc stearate.

[0181] Examples of the amine-based hardening accelerator 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. etc. may be mentioned.

[0182] (F) 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 0.2% 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 with respect to 100% by mass of the nonvolatile components in the resin composition.

[0183] (F) 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 1% 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 with respect to 100% by mass of the resin components in the resin composition.

[0184] <(G) Organic filler> The resin composition according to this 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) or component (A'). The (G) organic filler is usually immiscible with the resin components other than the (G) organic filler and is contained in the resin composition in the form of particles, and is contained in the cured product while maintaining the state of the particles. Further, the (G) organic filler may be used alone or in combination of two or more kinds.

[0185] (G) As the organic filler, particles of an organic material can be used. As the organic material contained in the (G) organic filler, a rubber component is preferable. 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 such as poly(meta)propyl acrylate, poly(meta)butyl acrylate, poly(meta)cyclohexyl acrylate, and poly(meta)octyl acrylate. Further, 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.

[0186] (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. It 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.

[0187] (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 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; "Staffiloid AC3355", "Staffiloid AC3816", "Staffiloid AC3816N", "Staffiloid AC3832", "Staffiloid AC4030", "Staffiloid AC3364" manufactured by Aika Industries Co., Ltd., and the like.

[0188] (G) 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 2% by mass or less, based on 100% by mass of the non-volatile components in the resin composition.

[0189] (G) The amount of the organic filler 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 resin component in the resin composition.

[0190] <(H) Optional Additives> The resin composition according to this embodiment may further contain (H) optional additives as optional components. The (H) optional additives as component (H) do not include those corresponding to the above-described components (A) to (G) or component (A'). Examples of the (H) optional additives 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; defoaming agents such as silicone-based defoaming agents, acrylic-based defoaming agents, fluorine-based defoaming agents, and vinyl resin-based defoaming 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-based 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. The (H) optional additives may be used alone or in combination of two or more.

[0191] <(I) Solvent> The resin composition according to this embodiment may further contain (I) a solvent as an optional volatile component in combination with the above-described non-volatile components such as components (A) to (H) and component (A'). Usually, an organic solvent is used as the (I) 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 (I) solvent may be used alone or in combination of two or more.

[0192] (I) The amount of the solvent can 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, based on 100% by mass of all the components in the resin composition, and may be 0% by mass.

[0193] <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. Some or all of the above-described components may be mixed simultaneously or in sequence. 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 the process. Further, stirring or shaking may be performed during the process of mixing each component.

[0194] <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 its 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 1900 poise or less, more preferably 1800 poise or less, and still more preferably 1700 poise or less. The lower limit can be, for example, 500 poise or more, 1000 poise or more, etc. (A) It is presumed that such a low minimum melt viscosity can be obtained because the glycidyloxy groups of the specific epoxy resin can easily enter between other molecules in the resin composition and interfere with the interaction between those molecules. However, the technical scope of the present invention is not limited by this presumption.

[0195] The minimum melt viscosity of the resin composition can be obtained by measuring the melt viscosity while raising the temperature under the measurement conditions of a frequency of 1 Hz, a strain of 5 degrees, a load of 100 g, a heating rate of 5 °C / min, and a temperature range of 60 °C to 180 °C using a dynamic viscoelasticity measuring device, and taking the lowest value of the measured melt viscosity as the minimum melt viscosity.

[0196] 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 contained in the resin composition, (I) volatile components such as solvents can 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 (H) and component (A') or reaction products thereof.

[0197] 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 0.0030 or less, more preferably 0.0027 or less, and still more preferably 0.0025 or less. The lower limit of the dielectric tangent Df is not particularly limited and can be, for example, 0.0010 or more.

[0198] The cured product of the resin composition according to this embodiment can usually have a low relative dielectric constant Dk. In one example, the relative dielectric constant Dk of the cured product is preferably 5.0 or less, more preferably 4.0 or less, and still more preferably 3.5 or less. The lower limit of the relative dielectric constant Dk is not particularly limited and can be, for example, 1.5 or more.

[0199] The dielectric tangent Df and relative dielectric constant Dk of the above-mentioned cured product can be measured by the split cylinder method at a measurement frequency of 10 GHz and a measurement temperature of 90°C. When the sample is the resin composition before curing, the resin composition may be cured under curing conditions of 190°C for 90 minutes to obtain a cured product, and the dielectric tangent Df and relative dielectric constant Dk of the cured product may be measured. As a specific measurement method, the method described in <Test 1. Measurement Test of Relative Dielectric Constant Dk and Dielectric Tangent Df> of the examples described later can be adopted.

[0200] The cured product of the resin composition according to this embodiment is excellent in adhesion to the conductor layer, and can be particularly excellent in adhesion after HAST. For example, when an insulating layer is formed by the cured product by the method described in <Test 5. Measurement test of adhesion to conductor layer> in the examples described later, and the adhesion strength between the insulating layer and the conductor layer after HAST is measured, a high adhesion strength can be obtained. The specific range of the adhesion strength after HAST is preferably 0.2 N / cm or more, more preferably 0.3 N / cm or more, and still more preferably 0.4 N / cm or more. The upper limit is not particularly limited, and can be, for example, 1.5 N / cm or less.

[0201] The cured product of the resin composition according to this embodiment can usually be excellent in adhesion to the conductor layer before HAST. For example, when an insulating layer is formed by the cured product by the method described in <Test 5. Measurement test of adhesion to conductor layer> in the examples described later, and the adhesion strength between the insulating layer and the conductor layer before HAST is measured, a high adhesion strength can be obtained. The specific range of the adhesion strength before HAST is preferably 0.4 N / cm or more, more preferably 0.5 N / cm or more, and still more preferably 0.6 N / cm or more. The upper limit is not particularly limited, and can be, for example, 2 N / cm or less.

[0202] The cured product of the resin composition according to this embodiment can usually have excellent smear removability. For example, when an insulating layer is formed by the cured product by the method described in <Test 3. Evaluation test of smear removability> in the examples described later, and its smear removability is evaluated, the maximum smear length can be made less than 5 μm.

[0203] The cured product of the resin composition according to this embodiment can usually have excellent crack resistance. For example, when an insulating layer is formed by the cured product by the method described in <Test 4. Evaluation test of crack resistance after desmear treatment> in the examples described later, and its crack resistance is evaluated, the number of cracks can be made 10 or less.

[0204] The cured product of the resin composition according to this embodiment can have a high glass transition temperature Tg. In one example, the glass transition temperature Tg of the cured product is preferably 130 °C or higher, more preferably 140 °C or higher, still more preferably 150 °C or higher, and particularly preferably 160 °C or higher. The upper limit of the glass transition temperature Tg is not particularly limited and can be, for example, 240 °C or lower, 220 °C or lower, 200 °C or lower, etc.

[0205] The glass transition temperature Tg of the above-mentioned cured product can be measured using a thermomechanical analyzer under the conditions of a measurement range from 25 °C to 250 °C and a heating rate of 5 °C / min. When the sample is the resin composition before curing, the resin composition can be cured under the curing conditions of 190 °C for 90 minutes to obtain a cured product, and the glass transition temperature Tg of the cured product can be measured. As a specific measurement method, the method described in <Test 2. Measurement Test of Glass Transition Temperature Tg> in the examples described later can be adopted.

[0206] <Use of 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.

[0207] <Resin Sheet> The resin sheet according to an 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.

[0208] From the viewpoint of thinning, the thickness of the resin composition layer provided 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.

[0209] Examples of the support include a film of a plastic material, a metal foil, and a release paper, with a film of a plastic material and a metal foil being preferred.

[0210] 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 polyolefin, triacetyl cellulose (TAC), polyethersulfide (PES), polyether ketone, polyimide, etc. Among them, polyethylene terephthalate and polyethylene naphthalate are preferred, and inexpensive polyethylene terephthalate is particularly preferred.

[0211] When using a metal foil as the support, examples of the metal foil include a copper foil, an aluminum foil, etc., with a copper foil being 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.

[0212] 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.

[0213] As the support, a support with a release layer having a release layer on the surface that bonds to 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.

[0214] 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.

[0215] The resin sheet may be provided with any member as necessary. 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 bonded 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.

[0216] The resin sheet can be manufactured, for example, by a method including forming a resin composition layer on a support. Specific examples include directly using a liquid (varnish-like) resin composition, or preparing a liquid (varnish-like) resin composition by mixing a solvent and the resin composition, applying this on the support, and further drying as necessary to form a heat-cured resin composition layer, thereby manufacturing the resin sheet. As the solvent, the same solvents as those described as (I) solvents in the components of the resin composition may be used.

[0217] The application of the resin composition can be carried out using an application device such as a die coater. Also, drying can be carried out by drying methods such as heating and hot air blowing. The drying conditions are not particularly limited, but the resin composition layer is dried so that the solvent content 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 using a resin composition containing 30% to 60% by mass of the solvent, the resin composition layer can be formed by drying at 50°C to 150°C for 3 minutes to 10 minutes.

[0218] 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.

[0219] <Circuit board> The circuit board according to one embodiment of the present invention includes a cured product of the above-described resin composition. Usually, the circuit board includes an insulating layer, and this insulating layer includes a cured product of the resin composition. The insulating layer may contain 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 above-described resin composition.

[0220] Preferably, the circuit board includes an inner layer substrate, and the above-described 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.

[0221] A method for manufacturing a circuit board according to a preferred example is a step (I) of forming a resin composition layer on the inner layer substrate, a step (II) of curing the resin composition layer and includes.

[0222] The "inner layer substrate" is a member that serves as the base material of a circuit board. Examples include glass epoxy substrates, metal substrates, polyester substrates, polyimide substrates, BT resin substrates, thermosetting polyphenylene ether substrates, and the like. Further, the inner layer substrate may have a conductor layer on one or both of its sides. Also, the conductor layer provided in the inner layer substrate may be pattern-processed. An inner layer substrate having a conductor layer (circuit) formed on one or both sides of the substrate is sometimes referred to as an "inner layer circuit board". Further, in the manufacture of a circuit board, an intermediate product on which an insulating layer and / or a conductor layer is to be further formed is also included in the term "inner layer substrate". Also, an inner layer substrate incorporating components may be used.

[0223] The formation of the resin composition layer on the inner layer substrate may be carried out, for example, by a formation method including applying a resin composition on the inner layer substrate and drying it as necessary, but it is preferably carried out using a resin sheet. The method for forming 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 thermocompression bonding the resin sheet to the inner layer substrate from the support side. Examples of the member for thermocompression bonding the resin sheet to the inner layer substrate (hereinafter also referred to as the "thermocompression bonding member") include a heated metal plate (such as a SUS mirror plate) or a metal roll (such as a SUS roll). Note that it is preferable to press through an elastic material such as heat-resistant rubber so that the resin sheet sufficiently follows the surface irregularities of the inner layer substrate rather than pressing the thermocompression bonding member directly against the resin sheet.

[0224] 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 thermocompression bonding temperature is preferably in the range of 60°C to 160°C, more preferably in the range of 80°C to 140°C, the thermocompression bonding 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 thermocompression bonding 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 of a pressure of 26.7 hPa or less.

[0225] Lamination may be performed using a commercially available vacuum laminator. Examples of commercially available vacuum laminators include, for example, a vacuum pressure type laminator manufactured by Meiki Seisakusho Co., Ltd., a vacuum applicator manufactured by Nichco Materials Co., Ltd., a batch type vacuum pressure laminator, and the like.

[0226] 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 the conditions for the heat bonding in the above lamination. The smoothing process can be performed using a commercially available laminator. Lamination and the smoothing process may be continuously performed using the above-described commercially available vacuum laminator.

[0227] 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.

[0228] 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 preferably be 5 minutes to 120 minutes, more preferably 10 minutes to 100 minutes, and even more preferably 15 minutes to 100 minutes.

[0229] The method for manufacturing a circuit board may include preheating the resin composition layer at a temperature lower than the curing temperature before the thermosetting of the resin composition layer. For example, prior to thermosetting 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, usually for 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 a smoothing treatment is performed after the lamination of the inner layer substrate and the resin sheet, the preheating can usually be performed after the smoothing treatment.

[0230] 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 the lamination of 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). Also, 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 performed between step (II) and step (III), between step (III) and step (IV), or between step (IV) and step (V).

[0231] 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, the holes may be formed by a processing method such as drilling, laser processing, or plasma processing. Among them, laser processing is preferred. 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.

[0232] 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. Also, according to the roughening treatment, smears (resin residues) can be removed from the insulating layer. Therefore, this roughening treatment is sometimes called "desmear treatment". For example, when holes are formed in step (III), smears may be formed in the holes. Therefore, it is preferable to perform the roughening treatment of step (IV) after step (III) to remove the smears.

[0233] The procedure 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.

[0234] Examples of the swelling liquid used for the roughening treatment include an alkaline solution, a surfactant solution, etc., and an alkaline solution is preferable. As the alkaline solution, a sodium hydroxide solution and a potassium hydroxide solution are more preferable. Examples of commercially available swelling liquids include "Swelling Dip Securigant P" and "Swelling Dip Securigance SBU" manufactured by Atotech Japan Co., Ltd. The swelling treatment with the swelling liquid can be performed, for example, by immersing the insulating layer in a 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 a swelling liquid at 40°C to 80°C for 5 minutes to 15 minutes.

[0235] Examples of the oxidizing agent used for the roughening treatment include an alkaline permanganate solution prepared by dissolving potassium permanganate or sodium permanganate 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 the commercially available oxidizing agent include alkaline permanganate solutions such as "Concentrate Compact CP" and "Dosing Solution Security Guard P" manufactured by Atotech Japan Co., Ltd.

[0236] As the neutralizing solution used for the roughening treatment, an acidic aqueous solution is preferable, and examples of the commercially available product include "Reduction Solution Security Guard P" manufactured by Atotech Japan Co., Ltd. The neutralization treatment with the neutralizing solution can be carried out by immersing the treated surface subjected to the oxidation treatment with the oxidizing agent in the neutralizing solution 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 solution at 40°C to 70°C for 5 minutes to 20 minutes is preferable.

[0237] The method for manufacturing a circuit board may include a step (V) of forming a conductor layer on the insulating layer. When the method for manufacturing a circuit board includes step (III) or (IV), the step (V) of forming the conductor layer is usually preferably carried out after steps (III) and (IV).

[0238] 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 layers formed from alloys 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.

[0239] The conductor layer may have a single-layer structure, or may have a multilayer 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 multilayer 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.

[0240] 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.

[0241] The conductor layer may be formed by plating. For example, by plating on the surface of the insulating layer by a conventionally known technique such as a semi-additive method or a full-additive method, a conductor layer having a desired wiring pattern can be formed. 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.

[0242] 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 a desired wiring pattern. After forming an electrolytic plating layer by electrolytic plating on the exposed electroless plating layer, the mask pattern is removed. Then, an unnecessary electroless plating layer can be removed by etching to form a conductor layer having a desired wiring pattern.

[0243] As another example, the conductor layer may be formed using a metal foil. When forming the conductor layer using a metal foil, it is preferable to perform step (V) 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 performed by a vacuum lamination method. The lamination conditions may be the same as those described for step (I). Next, step (II) is performed 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., and the like.

[0244] When a conductor layer is formed on the insulating layer, the method for manufacturing the circuit board may include performing an annealing treatment after forming the conductor layer. According to the annealing treatment, the adhesion between the insulating layer and the conductor layer can be enhanced. The annealing treatment can be performed, for example, by heating at 150°C to 210°C for 20 minutes to 180 minutes.

[0245] 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.

[0246] The method for manufacturing a circuit board may further include an arbitrary process in combination with the above-described processes. For example, the method for manufacturing a circuit board may include a process of providing a semiconductor chip so as to be joined to a conductor layer. Specifically, when manufacturing a circuit board for a semiconductor chip package including a semiconductor chip, the method for manufacturing the circuit board may include a process of providing the semiconductor chip. The semiconductor chip can adopt appropriate conditions under which the terminal electrode of the semiconductor chip and the conductor layer formed on the insulating layer can be conductively connected. For example, the conditions used in flip chip mounting may be adopted. Further, the semiconductor chip may be joined via an insulating adhesive or may be joined by reflow. Furthermore, 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 process of forming a sealing layer, a process of forming a solder resist layer, a process of dicing the manufactured circuit board into individual pieces, and the like.

[0247] Examples of the circuit board include a printed wiring board and a semiconductor chip package. Examples of the semiconductor chip package include an FC-CSP, a MIS-BGA package, an ETS-BGA package, a fan-out type WLP (Wafer Level Package), a fan-in type WLP, a fan-out type PLP (Panel Level Package), and a 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.

[0248] <Semiconductor device> The above circuit board can be used in the manufacture of semiconductor devices. A semiconductor device includes the above-described circuit board. Examples of semiconductor devices include various semiconductor devices used in electrical products (such as computers, mobile phones, smartphones, tablet devices, wearable devices, digital cameras, medical devices, and televisions, etc.) and vehicles (such as motorcycles, automobiles, trains, ships, and airplanes, etc.).

Example

[0249] 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. Also, 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.

[0250] <Synthesis Example 1: Production of Specific Epoxy Resin (A1)> (Explanation of Measurement Method) (1) Hydroxyl Equivalent Weight: The hydroxyl equivalent weight was measured in accordance with JIS K0070 standard, and the unit was expressed as "g / eq.". Unless otherwise specified, the hydroxyl equivalent weight of a phenolic resin represents the phenolic hydroxyl equivalent weight.

[0251] (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.

[0252] (3) Epoxy Equivalent Weight: The epoxy equivalent was measured in accordance with the JIS K7236 standard and expressed in the unit of "g / eq.". Specifically, using an automatic potentiometric titrator ("COM-1600ST" manufactured by Hiranuma Sangyo Co., Ltd.), chloroform was used as the solvent, a brominated tetraethylammonium acetate solution was added, and titration was performed with a 0.1 mol / L perchloric acid - acetic acid solution.

[0253] (4) Total chlorine content: The total chlorine content was measured in accordance with the JIS K7243-3 standard and expressed in the unit of "ppm". Specifically, using diethylene glycol monobutyl ether as the solvent, a 1 mol / L potassium hydroxide 1,2-propanediol solution was added and heat-treated, and then titration was performed with a 0.01 mol / L silver nitrate solution using an automatic potentiometric titrator ("COM-1700" manufactured by Hiranuma Sangyo Co., Ltd.).

[0254] (5) Melt viscosity: The melt viscosity was measured at 150 °C using an ICI viscosity measuring device ("CV-1S" manufactured by Toa Kogyo Co., Ltd.).

[0255] (6) GPC (gel permeation chromatography) measurement: For GPC measurement, an instrument with columns ("TSKgel G4000HXL", "TSKgel G3000HXL", "TSKgel G2000HXL" manufactured by Tosoh Corporation) connected in series to the main body ("HLC-8220GPC" manufactured by Tosoh Corporation) was used, and the measurement was carried out at a column temperature of 40 °C. Tetrahydrofuran (THF) was used as the eluent, the flow rate was 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.

[0256] (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 in the cell. After applying the sample dissolved in chloroform onto the cell and drying it, the transmittance was measured in the wavenumber range of 450 cm -1 ~4000 cm -1 .

[0257] (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 the sample dissolved in acetonitrile.

[0258] (Step 1. Synthesis of polyhydric hydroxy resin (PH1)) Into a reaction apparatus consisting of a glass separable flask equipped with a stirrer, thermometer, nitrogen inlet tube, dropping funnel, and condenser, 500 parts of 2,6-xylenol and 7.1 parts of 47% BF3 ether complex were charged and heated to 100 °C while stirring. While maintaining the same temperature, 60.1 parts of dicyclopentadiene (0.11 times the molar amount relative to 2,6-xylenol) 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, 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 the 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, and the lower aqueous 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 polyhydric hydroxy resin (PH1, in formula (A-5), R a1 is a methyl group, i a is 2) were obtained.

[0259]

Chemical formula

[0260] 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, and the m a content of m = 0 body was 2.8 area%, and the m a content of m = 1 body was 86.2 area%, and the m a content of m = 2 or more bodies was 11.0 area%. The melt viscosity of the polyhydroxy resin (PH1) at 150°C was 0.05 Pa·s.

[0261] (Step 2. Synthesis of polyhydroxy resin (PH2)) Into the same reactor as 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 filtered. Thereafter, under a reduced pressure of 5 mmHg, it was heated to 160°C to evaporate and remove MIBK, and 558 parts of a reddish-brown polyhydroxy resin (PH2, in formula (A-6), R a1 is a methyl group, and i a is 2) was obtained.

[0262] [Chemical formula]

[0263] 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 dicyclopenthenyl group is introduced as the side chain R a6 was at 3040 cm-1 appeared in the vicinity. 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, and the k a =0 body content was 6.2 area%, and k a =1 body content was 74.0 area%, and 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.

[0264] (Step 3. Synthesis of polyhydroxy resin (P1)) Into the same reactor as 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 with stirring. While maintaining the same temperature, 20 parts (0.36 times the mole of the hydroxyl group 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, neutralized with 1.3 parts of sodium hydrogen carbonate, 105 parts of warm water at 90 °C was added for washing, and the lower-layer water tank was separated and removed. The mixture was heated to 120 °C for reflux dehydration and filtered. Then, under a reduced pressure of 5 mmHg, it was heated to 180 °C to evaporate and remove MIBK, and 116 parts of a reddish-brown polyhydroxy resin (P1) was obtained.

[0265] The hydroxyl equivalent of the polyhydric hydroxy 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 polyhydric hydroxy resin (P1) by ESI-MS (negative) was measured, M− = 375, 507, 629, 639, 761 were confirmed, and it was confirmed that it was a polyhydric hydroxy resin of formula (A-4), having a structure with 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 polyhydric hydroxy resin (P1) was 693, the number average molecular weight Mn was 472, and the content of the n a =0 species was 10.8 area%, and the n a =1 species content was 61.4 area%, and the n a content of =2 species or more was 27.8 area%. The melt viscosity of the polyhydric hydroxy resin (P1) at 150°C was 0.11 Pa·s.

[0266] (Step 4. Synthesis of Specific Epoxy Resin (A1)) Into a reaction apparatus equipped with a stirrer, a thermometer, a nitrogen blowing tube, a dropping funnel, and a condenser, 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.

[0267]

Chemical formula

[0268] 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 brine. 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 specific epoxy resin (A1) was obtained.

[0269] The epoxy equivalent of the specific 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 specific epoxy resin (A1) was 755, the number average molecular weight Mn was 475, a the content of the n a = 0 form was 9.1 area%, the content of the n a = 1 form was 41.1 area%, and the content of the n

[0270] <Synthesis Example 2: Synthesis of maleimide resin (B1)> According to Synthesis Example 1 of Publication No. 2020-500211 of the Technical Report of the Japan Institute of Invention and Innovation, a MEK solution (non-volatile component 62 mass%) of a maleimide resin (B1) represented by the following formula (b-6) was prepared. The Mw / Mn of this maleimide resin (B1) was 1.81, and t’’ in the formula (b-6) was 1.47 (mainly 1, 2 or 3).

[0271]

Chemical formula

[0272] <Synthesis Example 3: Synthesis of vinyl resin (D1)> According to Example 1 of International Publication No. 2017 / 115813, 3.0 mol (390.6 g) of divinylbenzene, 1.8 mol (229.4 g) of ethylvinylbenzene, 10.2 mol (1066.3 g) of styrene, and 15.0 mol (1532.0 g) of n-propyl acetate were charged into a 5.0 L reactor, and 600 mmol of a boron trifluoride diethyl ether complex was added at 70°C, followed by reacting for 4 hours. The polymerization solution was terminated with an aqueous sodium hydrogen carbonate solution. Then, the oil layer was washed three times with pure water and devolatilized under reduced pressure at 60°C to recover the polymer. The obtained polymer was weighed, and it was confirmed that 896.7 g of vinyl resin (D1) was obtained as the polymer. The weight average molecular weight Mw of the vinyl resin (D1) was 41300.

[0273] <Synthesis Example 4: Synthesis of Vinyl Resin (D2)> 48.9 g (0.4 mol) of 2,6-dimethylphenol, 272.0 g (1.4 mol) of α,α'-dihydroxy-1,3-diisopropylbenzene, 280 g of xylene, and 70 g of activated clay were charged into a 1 L flask equipped with a thermometer, a condenser, a Dean-Stark trap, and a stirrer, and heated to 120°C with stirring. Further, the temperature was raised to 210°C while removing the distillate water through the Dean-Stark tube, and the reaction was carried out for 3 hours. Then, it was cooled to 140°C, and 146.6 g (1.2 mol) of 2,6-dimethylphenol was charged. Then, the temperature was raised to 220°C and the reaction was carried out for 3 hours. After the reaction, it was air-cooled to 100°C, diluted with 300 g of toluene, and the activated clay was removed by filtration. Then, under reduced pressure, low molecular weight substances such as the solvent and unreacted substances were distilled off to obtain 365.3 g of an intermediate phenol compound. The hydroxyl equivalent (phenol equivalent) of the obtained intermediate phenol compound was 299 g / eq.

[0274] To a 2 L flask equipped with a thermometer, a cooling tube, and a stirrer, 365.3 g of the obtained intermediate phenol compound, 0.184 g (0.001 mol) of 2,4-dinitrophenol (2,4-DNP), 23.5 g (0.073 mol) of tetrabutylammonium bromide (TBAB), 209 g (1.37 mol) of chloromethylstyrene, and 400 g of methyl ethyl ketone were added, and the temperature was raised to 75 °C while stirring. Next, a 48% aqueous NaOH solution was added dropwise to the reaction vessel maintained at 75 °C over 20 minutes. After completion of the dropwise addition, stirring was continued at 75 °C for 4 hours. After 4 hours, it was cooled to room temperature, 100 g of toluene was added, and further 10% HCl was added for neutralization. Then, the aqueous phase was separated by liquid separation and further washed by liquid separation three times with 300 m of water. The obtained organic phase was concentrated by distillation, and methanol was added to reprecipitate the product. The precipitate was filtered and dried to obtain a vinyl resin (D2) represented by the following formula (D2). The weight average molecular weight of the vinyl resin (D2) was 1500.

[0275] [Chemical formula]

[0276] [Synthesis Example 5. Synthesis of Active Ester Compound (E1)] To a flask equipped with a thermometer, a dropping funnel, a cooling tube, a fractionating tube, and a stirrer, 320 g (2.0 mol) of 2,7-dihydroxynaphthalene, 184 g (1.7 mol) of benzyl alcohol, and 5.0 g of p-toluenesulfonic acid monohydrate were charged, and it was stirred while blowing nitrogen at room temperature. Then, the temperature was raised to 150 °C and stirred for 4 hours while distilling off the generated water out of the system. After completion of the reaction, 900 g of methyl isobutyl ketone and 5.4 g of a 20% aqueous sodium hydroxide solution were added for neutralization. Then, the aqueous layer was removed by liquid separation, and it was washed three times with 280 g of water, and methyl isobutyl ketone was removed under reduced pressure to obtain 460 g of a benzyl-modified naphthalene compound (E0). The obtained benzyl-modified naphthalene compound (E0) was a black solid, and the hydroxyl group equivalent was 180 g / eq.

[0277] Into a flask equipped with a thermometer, a dropping funnel, a condenser, a fractionating column, and a stirrer, 203.0 g of isophthaloyl chloride (number of moles of acid chloride groups: 2.0 moles) and 1400 g of toluene were charged, and the system was purged with nitrogen under reduced pressure and dissolved. Next, 72.4 g (0.67 moles) of ortho-cresol and 240 g of a benzyl-modified naphthalene compound (E0) (number of moles of phenolic hydroxyl groups: 1.33 moles) were charged, and the system was purged with nitrogen under reduced pressure and dissolved. Then, 0.70 g of tetrabutylammonium bromide was dissolved, and while purging with nitrogen gas, the temperature inside the system was controlled to 60 °C or lower, and 400 g of a 20% aqueous sodium hydroxide solution was added dropwise over 3 hours. Next, under these conditions, stirring was continued for 1.0 hour to allow the reaction to proceed.

[0278] After completion of the reaction, the mixture was allowed to stand and separated, and the aqueous layer was removed. Further, water was added to the toluene layer in which the reaction product was dissolved, and the mixture was stirred and mixed for 15 minutes, allowed to stand and separated, and the aqueous layer was removed. This operation was repeated until the pH of the aqueous layer reached 7. Then, water was removed by decanter dehydration to obtain an active ester compound (E1) in the form of a toluene solution containing 65% by mass of non-volatile components. The active ester group equivalent of the obtained active ester compound (E1) was 238 g / eq.

[0279] <Examples 1 to 10 and Comparative Examples 1 to 3> (1) Production of resin composition: Each component was weighed and mixed according to the compounding compositions described in Tables 1 and 2 below, and further 10 parts of MEK and 10 parts of cyclohexanone were mixed and uniformly dispersed using a high-speed rotary mixer to obtain a resin composition (resin varnish). The compounding compositions described in Tables 1 and 2 represent the amounts (parts by mass) of non-volatile components. The details of each component described in Tables 1 and 2 are as follows.

[0280] (A) Specific epoxy resin: · Epoxy resin A1: The specific epoxy resin (A1) produced in Synthesis Example 1. Epoxy equivalent 354 g / eq.

[0281] (A’) Optional epoxy resin: · HP-4032-SS: Naphthalene-type epoxy resin manufactured by DIC Corporation, epoxy equivalent 144 g / eq. · NC-3000L: Biphenyl-type epoxy resin manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent 270 g / eq.

[0282] (B) Maleimide resin: · Maleimide B1: Maleimide resin (B1) synthesized in Synthesis Example 2. · MIR-3000-70MT: Aromatic maleimide resin manufactured by Nippon Kayaku Co., Ltd. having a structure represented by the following formula (B2) (in formula (B2), n represents 1 to 100), toluene·MEK solution with a non-volatile component of 70% by mass. · SLK-6895: Aliphatic maleimide compound manufactured by Shin-Etsu Chemical Co., Ltd. · SLK-1500: Aliphatic maleimide compound manufactured by Shin-Etsu Chemical Co., Ltd.

[0283]

Chemical formula

[0284] (C) Inorganic filler: · SO-C2: Spherical silica surface-treated with an amino-based silane coupling agent (「KBM573」manufactured by Shin-Etsu Chemical Co., Ltd.), average particle size 0.5 μm, specific surface area 5.8 m 2 / g, manufactured by Admatechs Co., Ltd.

[0285] (D) Polymerizable unsaturated resin: · OPE-2St-1200: Styrene-based polymerizable unsaturated resin having a polyphenylene ether backbone, toluene solution with a non-volatile component of 65% by mass, manufactured by Mitsubishi Gas Chemical Company, Inc. · Vinyl resin D1: Vinyl resin (D1) synthesized in Synthesis Example 3. · NE-V-1100-70T: Allyl-based polymerizable unsaturated resin manufactured by DIC Corporation. A resin having an allyl group at the end and containing an active ester group. Toluene solution with a non-volatile component of 70% by mass. · Vinyl resin D2: Vinyl resin (D2) synthesized in Synthesis Example 4.

[0286] (E-1) Active ester resin: · HPC-8150-62T: An active ester resin with a naphthalene structure manufactured by DIC, an active ester group equivalent of 230 g / eq., and a toluene solution with a non-volatile component of 61.5 mass%. · HPC-8000L-65MT: An active ester resin containing a dicyclopentadiene-type diphenol structure manufactured by DIC, an active ester group equivalent of 223 g / eq., and a toluene / MEK solution with a non-volatile component of 65 mass%. · Active ester resin E1: The active ester resin (E1) synthesized in Synthesis Example 5, with an active ester group equivalent of 238 g / eq.

[0287] (E-2) Optional curing agent: · LA-3018-50P: A phenolic resin manufactured by DIC, with a phenolic hydroxyl group equivalent of 151 g / eq., and a 1-methoxy-2-propanol solution with a non-volatile component of 50 mass%.

[0288] (F) Curing accelerator: · 1B2PZ: An imidazole-based curing accelerator manufactured by Shikoku Kasei Kogyo Co., Ltd.

[0289] (G) Organic filler: · EXL-2655: An organic filler containing a rubber component manufactured by Dow.

[0290] (2) Manufacture of resin sheet: As a support, a polyethylene terephthalate film with a release layer (「AL5」manufactured by Lintec Corporation, thickness 38 μm) was prepared. On the release layer of this support, the obtained resin composition was uniformly applied so that the thickness of the resin composition layer after drying would be 40 μm. Then, the resin composition was dried at 80°C to 100°C (average 90°C) for 4 minutes to obtain a resin sheet A having a layer structure of resin composition layer / support.

[0291] Also, a resin sheet B was manufactured by the same manufacturing method as resin sheet A, except that the coating thickness of the resin composition was changed so that the thickness of the resin composition layer after drying would be 25 μm.

[0292] <Test 1. Measurement Test of Relative Dielectric Constant Dk and Dissipation Factor Df> The resin sheet A was heated in an oven at 190 °C for 90 minutes to cure the resin composition layer. Then, the support was peeled off to obtain a cured product of the resin composition layer. The cured product was cut into pieces with a length of 80 mm and a width of 2 mm to obtain a cured product sample for dielectric property measurement.

[0293] For the cured product sample, using a measuring device (「HP8362B」manufactured by Agilent Technologies), the relative dielectric constant Dk and the dissipation factor Df were measured at a measurement frequency of 10 GHz and a measurement temperature of 90 °C by the split cylinder method. The measurement was carried out on two test pieces, and the average was calculated.

[0294] <Test 2. Measurement Test of Glass Transition Temperature Tg> The resin sheet A was heated in an oven at 190 °C for 90 minutes to cure the resin composition layer. Then, the support was peeled off to obtain a cured product of the resin composition layer. The cured product was cut into pieces with a length of 20 mm and a width of 6 mm to be used as a cured product sample for glass transition temperature measurement. For this cured product sample, using a TMA device (a thermomechanical analyzer, manufactured by Rigaku), the glass transition temperature Tg was measured at a heating rate of 5 °C / min from 25 °C to 250 °C. The same cured product sample was measured twice, and the value of the second measurement was recorded.

[0295] <Test 3. Evaluation Test of Smear Removal Property> (1) Preparation of Inner Layer Substrate: Both sides of 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) with an inner layer circuit formed were etched with a micro-etching agent (「CZ8101」manufactured by Meck) by 1 μm to perform roughening treatment on the copper surface, and an inner layer substrate was obtained.

[0296] (2) Lamination of Resin Sheet A: Using a batch-type vacuum pressure laminator (manufactured by Nikkco Materials Co., Ltd., two-stage build-up laminator "CVP700"), resin sheet A was laminated on both sides of the inner layer substrate such that the resin composition layer was in contact with the inner layer substrate. The lamination was carried out by adjusting the air pressure to 13 hPa or less under reduced pressure for 30 seconds and then performing pressure bonding at 120 °C and a pressure of 0.74 MPa for 30 seconds. Subsequently, heat pressing was performed at 100 °C and a pressure of 0.5 MPa for 60 seconds to smooth the resin composition layer.

[0297] (3) Thermal curing of the resin composition layer: Thereafter, the inner layer substrate with resin sheet A laminated thereon was placed in an oven at 130 °C and heated for 30 minutes, and then transferred to an oven at 170 °C and heated for 30 minutes to thermally cure the resin composition layer and form an insulating layer. Thereafter, the support was peeled off to obtain a cured substrate having a structure of insulating layer / inner layer substrate / insulating layer.

[0298] (4) Formation of via holes: Using a CO2 laser processing machine (manufactured by Via Mechanics Co., Ltd., "LK-2K212 / 2C"), the insulating layer of the obtained cured substrate was subjected to drilling under the conditions of a frequency of 2000 Hz, a pulse width of 3 μs, an output of 0.95 W, and a number of shots of 3 to form via holes. The aperture diameter (diameter, top diameter) on the surface of the insulating layer of the formed via holes was 50 μm, and the diameter (bottom diameter) on the bottom surface of the insulating layer was 50 μm.

[0299] (5) Roughening treatment: The insulating layer of the cured substrate having via holes formed thereon was subjected to a desmear treatment as a roughening treatment. As the desmear treatment, the following wet desmear treatment was carried out.

[0300] (Wet desmear treatment) The cured substrate was immersed in a swelling solution (an aqueous solution of "Swelling Dip & Securigant P" manufactured by Atotech Japan Co., Ltd., diethylene glycol monobutyl ether, and sodium hydroxide) at 60°C for 10 minutes. Next, the cured substrate was immersed in an oxidizing agent solution (an aqueous solution of "Concentrate Compact P" manufactured by Atotech Japan Co., Ltd., with a potassium permanganate concentration of approximately 6% and a sodium hydroxide concentration of approximately 4%) at 80°C for 25 minutes. Finally, the cured substrate was immersed in a neutralizing solution (an aqueous solution of sulfuric acid and "Reduction Solution & Securigant P" manufactured by Atotech Japan Co., Ltd.) at 40°C for 5 minutes. Thereafter, the cured substrate was dried at 80°C for 15 minutes. The cured substrate after this desmear treatment may hereinafter be referred to as "Substrate A for evaluation".

[0301] (6) Evaluation of smear removability: Regarding Substrate A for evaluation, the periphery of the bottom of the via hole was observed with a scanning electron microscope (SEM). From the obtained image, the length of the longest smear (maximum smear length) among the smears (resin residues) extending from the wall surface of the bottom of the via hole was measured and evaluated according to the following criteria. "None": The maximum smear length is less than 5 μm. There is no smear with a smear length of 5 μm or more. "Yes": The maximum smear length is 5 μm or more.

[0302] <Test 4. Evaluation test of crack resistance after desmear treatment> (1) Preparation of inner layer substrate: As the inner layer substrate, a core material ("E705GR" manufactured by Resonac Co., Ltd., with a thickness of 400 μm) having circular copper pads (copper thickness: 35 μm) with a diameter of 350 μm formed in a lattice pattern at intervals of 400 μm so that the residual copper ratio was 60% was prepared.

[0303] (2) Lamination of resin sheet B: Using a batch-type vacuum pressure laminator (manufactured by Nippon Materials Co., Ltd., 2-stage build-up laminator "CVP700"), the resin sheet B was laminated on both sides of the inner layer substrate such that the resin composition layer was in contact with the inner layer substrate. The lamination was carried out by adjusting the air pressure to 13 hPa or less under reduced pressure for 30 seconds and then performing pressure bonding at 100 °C and a pressure of 0.74 MPa for 30 seconds. Subsequently, heat pressing was performed at 100 °C and a pressure of 0.5 MPa for 60 seconds to smooth the resin composition layer.

[0304] (3) Thermal curing of the resin composition layer: Thereafter, the inner layer substrate with the resin sheet B laminated thereon was placed in an oven at 130 °C and heated for 30 minutes, and then transferred to an oven at 175 °C and heated for 40 minutes to thermally cure the resin composition layer and form an insulating layer. Thereafter, the support was peeled off to obtain a cured substrate having a structure of insulating layer / inner layer substrate / insulating layer.

[0305] (4) Desmear treatment: The obtained cured substrate was immersed in a swelling solution (manufactured by Atotech Japan Co., Ltd. "Swelling Dip·Security Gun P", an aqueous solution of diethylene glycol monobutyl ether and sodium hydroxide) at 60 °C for 10 minutes. Subsequently, the cured substrate was immersed in an oxidizing agent solution (manufactured by Atotech Japan Co., Ltd. "Concentrate·Compact P", an aqueous solution with a potassium permanganate concentration of approximately 6% and a sodium hydroxide concentration of approximately 4%) at 80 °C for 30 minutes. Finally, the cured substrate was immersed in a neutralizing solution (manufactured by Atotech Japan Co., Ltd. "Reduction Solution·Security Gun P", an aqueous sulfuric acid solution) at 40 °C for 5 minutes. Thereafter, the cured substrate was dried at 80 °C for 15 minutes. The cured substrate after this desmear treatment may be hereinafter referred to as "evaluation substrate B".

[0306] (5) Evaluation of crack resistance: Regarding evaluation substrate B, 100 copper pad portions were observed to confirm the presence or absence of cracks in the insulating layer, and the crack resistance was evaluated according to the following criteria. "Good": 10 cracks or less. "Poor": More than 10 cracks.

[0307] <Test 5. Measurement Test of Adhesion with Conductor Layer> (1) Substrate Treatment of Copper Foil: The shiny surface of electrolytic copper foil (「3EC-III」manufactured by Mitsui Mining & Smelting Co., Ltd., thickness 35 μm) was immersed in a micro-etching agent (「CZ8101」manufactured by Meck). By the above immersion, the surface of the copper foil was roughened, and the arithmetic mean roughness Ra of the surface became 1 μm. Thereafter, a rust prevention treatment (「CL8300」manufactured by Meck) was applied to the surface. This obtained copper foil may be hereinafter referred to as 「CZ copper foil」. This CZ copper foil was further heat-treated in an oven at 130 °C for 30 minutes.

[0308] (2) Lamination of Copper Foil and Formation of Insulating Layer: An inner layer substrate laminated with resin sheet A was prepared by the same method as in steps (1) and (2) of <Test 3. Evaluation Test of Smear Removal Property>. Thereafter, the supports on both sides were peeled off to expose both resin composition layers. The above CZ copper foil was laminated on these resin composition layers. This lamination was performed such that the treated surface of the CZ copper foil (the surface subjected to roughening treatment and rust prevention treatment) was joined to the resin composition layer. Also, the above lamination was carried out by laminating under the same conditions as in step (2) of <Test 3. Evaluation Test of Smear Removal Property>. Thereafter, the resin composition layer was cured under curing conditions of 190 °C for 90 minutes to form an insulating layer. By the formation of the insulating layer, a sample substrate having a structure of CZ copper foil / insulating layer / inner layer substrate / insulating layer / CZ copper foil was obtained.

[0309] (3) Measurement of Adhesion Strength before HAST: The fabricated sample substrate was cut into small pieces of 150×30 mm to obtain test pieces. Cuts were formed on the copper foil of the test pieces using a cutter to surround a rectangular portion with a width of 10 mm and a length of 100 mm. One end of the rectangular portion of the copper foil was peeled off and grasped with a gripping tool ("AC-50C-SL" manufactured by TSE), and the load [kgf / cm (N / cm)] when peeled off vertically by 35 mm was measured as the adhesion strength. The measurement of the adhesion strength was carried out using an Instron universal testing machine at room temperature at a speed of 50 mm / min in accordance with JIS C6481. Since the above adhesion strength represents the load required to peel off the copper foil corresponding to the base from the insulating layer, it indicates the adhesion between the conductor layer and the insulating layer. Hereinafter, the adhesion strength measured in this step (3) may be referred to as "adhesion strength (before HAST)".

[0310] (4) Measurement of adhesion strength after HAST: The above sample substrate was subjected to a HAST test in an environment of a temperature of 130°C and a humidity of 85%RH for 100 hours. Thereafter, for the sample substrate, the adhesion strength was measured by the same method as in the above step (3). Hereinafter, the adhesion strength measured in this step (4) may be referred to as "adhesion strength (after HAST)".

[0311] <Test 6. Measurement of melt viscosity> The resin composition layer of the resin sheet A was peeled off from the support film, and the melt viscosity of the resin composition layer was measured with a dynamic viscoelasticity measuring device ("G-3000" manufactured by UBM) at a frequency of 1 Hz, a strain of 5 degrees, a load of 100 g, a heating rate of 5°C / min, and a temperature range of 60°C to 180°C to obtain the minimum melt viscosity of the resin composition.

[0312] <Results> The results of the above-described examples and comparative examples are shown in the following table.

[0313]

Table 1

[0314]

Table 2

Claims

1. A resin composition comprising (A) an epoxy resin represented by formula (A-1), (B) a maleimide resin, and (C) an inorganic filler, wherein the amount of (B) the maleimide resin is 2% by mass or more and 30% by mass or less based on 100% by mass of the resin components in the resin composition, the amount of (C) the inorganic filler is 65% by mass or more based on 100% by mass of the non-volatile components in the resin composition. 【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 (B) the maleimide resin contains an aromatic maleimide resin.

3. The resin composition according to Claim 1, wherein (B) the maleimide resin contains a maleimide resin containing an alicyclic skeleton.

4. The resin composition according to Claim 1, which contains (D) a polymerizable unsaturated resin.

5. The resin composition according to Claim 1, which contains (E) a curing agent containing (E-1) an active ester-based resin.

6. 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 5.

7. A cured product of the resin composition according to any one of Claims 1 to 5.

8. A circuit board comprising a cured product of the resin composition according to any one of Claims 1 to 5.

9. A semiconductor device comprising the circuit board according to Claim 8.

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