resin composition

Abstract

To provide a novel resin composition that exhibits low viscosity and yields a cured product with superior adhesion to a conductor layer under high-temperature and high-humidity conditions.SOLUTION: A resin composition includes: a polyfunctional epoxy resin with four or more monovalent organic groups having an epoxy group (referred to as "organic groups X") in each molecule, wherein the polyfunctional epoxy resin features an aromatic ring with two or more organic groups X on each constituent ring; and an active ester resin.SELECTED DRAWING: None

Description

[Technical Field]

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

[0002] Resin compositions containing epoxy resins and their curing agents produce cured products with excellent insulating properties, heat resistance, adhesion, and other properties, and have therefore been widely used as insulating materials for circuit boards such as printed wiring boards and rewiring boards for semiconductor chip packages.

[0003] On the other hand, with the recent increase in communication speeds, insulating materials for circuit boards are required to have excellent dielectric properties (low dielectric dissipation factor) to reduce transmission loss when operating in high-frequency environments.In addition, with the further miniaturization and high integration of electronic devices, circuits are becoming more multilayered and miniaturized, and the insulating materials used are required to have low viscosity to achieve good circuit embedding properties.

[0004] Known insulating materials with excellent dielectric properties include those that use specific curing agents such as active ester resins that can reduce or suppress the generation of polar groups such as secondary hydroxyl groups during the curing reaction of epoxy resins (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2018 / 235424 Summary of the Invention [Problem to be solved by the invention]

[0006] Although resin compositions using active ester resins exhibit good dielectric properties, there is room for improvement in terms of lowering viscosity, and when an insulating layer is formed using such a resin composition, the insulating layer tends to have poor adhesion to a conductor layer after exposure to a high-temperature, high-humidity environment.

[0007] An object of the present invention is to provide a novel resin composition that exhibits low viscosity and can provide a cured product that exhibits good adhesion to a conductor layer when exposed to a high-temperature, high-humidity environment. [Means for solving the problem]

[0008] As a result of extensive investigations, the present inventors have found that the above problems can be solved by a resin composition having the following constitution, and have thus completed the present invention.

[0009] That is, the present invention includes the following. [1] A polyfunctional epoxy resin containing four or more monovalent organic groups having an epoxy group (hereinafter referred to as "organic group X") in the molecule, the polyfunctional epoxy resin containing an aromatic ring having two or more organic groups X per constituent ring, and Active Ester Resin A resin composition comprising: [2] The resin composition according to [1], wherein the polyfunctional epoxy resin contains a structure represented by the following formula (1): [ka] (In formula (1), Each X independently represents a monovalent organic group having an epoxy group, R S each independently represents a substituent, * represents a bond, n1 represents an integer of 2 or greater, n2 represents an integer equal to or greater than 0, Here, n1 and n2 satisfy n1+n2≦5. [3] The resin composition according to [2], wherein the polyfunctional epoxy resin is represented by the following formula (2): [ka] (In formula (2), X, R S , n1 and n2 are the same as above, L represents a single bond or a divalent linking group. [4] The resin composition according to [3], wherein the divalent linking group represented by L in formula (2) is selected from the group consisting of divalent hydrocarbon groups having 1 to 10 carbon atoms which may have a substituent, oxygen atoms, sulfonyl groups, carbonyl groups, carbonate groups, and divalent groups formed from combinations thereof. [5] The resin composition according to any one of [1] to [4], wherein the polyfunctional epoxy resin is liquid at a temperature of 20°C. [6] The resin composition according to any one of [1] to [5], wherein the molecular weight of the polyfunctional epoxy resin is 3,000 or less. [7] The resin composition according to any one of [1] to [6], further comprising an inorganic filler. [8] The resin composition according to [7], wherein the content of the inorganic filler is 40% by mass or more when the nonvolatile components in the resin composition are 100% by mass. [9] The resin composition according to any one of [1] to [8], wherein the content of the polyfunctional epoxy resin is 1% by mass or more and 45% by mass or less when the resin component in the resin composition is taken as 100% by mass.

[10] The resin composition according to any one of [1] to [9], wherein the mass ratio of the active ester resin to the polyfunctional epoxy resin [active ester resin / polyfunctional epoxy resin] is 1 or more.

[11] The resin composition according to any one of [1] to

[10] , which is used for an insulating layer of a circuit board.

[12] A resin sheet comprising a support and a layer of the resin composition according to any one of [1] to

[11] provided on the support.

[13] The resin sheet according to

[12] , wherein the support is a thermoplastic resin film or a metal foil.

[14] A cured product of the resin composition according to any one of [1] to

[11] .

[15] A circuit board comprising an insulating layer made of a cured product of the resin composition according to any one of [1] to

[11] .

[16] A semiconductor device comprising the circuit board according to

[15] . [Effects of the Invention]

[0010] According to the present invention, a novel resin composition can be provided that exhibits low viscosity and can produce a cured product that exhibits good adhesion to a conductor layer when exposed to a high-temperature, high-humidity environment. DETAILED DESCRIPTION OF THE INVENTION

[0011] <Terminology>

[0012] In this specification, the term "organic group" refers to a group containing at least carbon atoms as skeletal atoms, and may be linear, branched, or cyclic. In this specification, unless otherwise specified, the number of skeletal atoms of an organic group is preferably 1 to 50, more preferably 1 to 30, and even more preferably 1 to 20 or 1 to 10. The number of skeletal atoms does not include the number of skeletal atoms of an epoxy group. Examples of organic groups include groups containing one or more skeletal atoms (including at least a carbon atom) selected from carbon atoms, oxygen atoms, nitrogen atoms, and sulfur atoms.

[0013] As used herein, the term "hydrocarbon group" refers to a group obtained by removing one or more hydrogen atoms from a hydrocarbon compound. Specifically, a monovalent hydrocarbon group refers to a group obtained by removing one hydrogen atom from a hydrocarbon compound, and a divalent hydrocarbon group refers to a group obtained by removing two hydrogen atoms from a hydrocarbon compound. Here, the hydrocarbon group may be either a saturated or unsaturated hydrocarbon group and may have a cyclic structure. Examples of monovalent hydrocarbon groups include alkyl groups, alkenyl groups, alkynyl groups, alkapolyenyl groups, and monovalent carbocyclic groups. Examples of divalent hydrocarbon groups include alkylene groups, alkenylene groups, alkynylene groups, alkapolyenylene groups, and divalent carbocyclic groups. In this specification, unless otherwise specified, the number of carbon atoms in a hydrocarbon group is preferably 1 or more, more preferably 2 or more, even more preferably 3 or more, 4 or more, 5 or more, or 6 or more, and is preferably 50 or less, more preferably 40 or less, even more preferably 30 or less, 20 or less, 18 or less, 16 or less, 14 or less, or 12 or less. The number of carbon atoms in any substituents is not included in this number of carbon atoms.

[0014] As used herein, the term "heteroatom-containing hydrocarbon group" refers to a group obtained by removing one or more hydrogen atoms from a hydrocarbon compound containing a heteroatom. Specifically, a monovalent heteroatom-containing hydrocarbon group refers to a group obtained by removing one hydrogen atom from a hydrocarbon compound containing a heteroatom, and a divalent heteroatom-containing hydrocarbon group refers to a group obtained by removing two hydrogen atoms from a hydrocarbon compound containing a heteroatom. In the "heteroatom-containing hydrocarbon group" herein, the heteroatom may be bonded to any of the carbon atoms constituting the group. For example, (i) it may be interposed between carbon-carbon bonds, or (ii) it may be bonded to a terminal carbon. Furthermore, in the "heteroatom-containing hydrocarbon group" herein, the bond may extend from either a carbon atom or a heteroatom. The heteroatom-containing hydrocarbon group may be saturated or unsaturated and may have a cyclic structure. As used herein, the term "heteroatom" refers to an atom other than carbon and hydrogen atoms, such as an oxygen atom, nitrogen atom, sulfur atom, or silicon atom. Examples of monovalent heteroatom-containing hydrocarbon groups include heteroalkyl groups, heteroalkenyl groups, heteroalkynyl groups, heteroalkapolyenyl groups, and monovalent heterocyclic groups. Examples of monovalent heteroatom-containing hydrocarbon groups also include monovalent groups formed by bonding a divalent group selected from the group consisting of -O-, -S-, -C(=O)-, -S(=O)-, -S(=O)2-, -N(R)-, -Si(R)2-, and combinations thereof to a bond of a monovalent carbocyclic group or a monovalent heterocyclic group (wherein R represents a hydrogen atom or a substituent described below, the same applies hereinafter). In this specification, unless otherwise specified, the number of heteroatoms in a heteroatom-containing hydrocarbon group is preferably 1 or more, 2 or more, or 3 or more, and preferably 10 or less, 8 or less, or 6 or less, and the number of carbon atoms therein is, unless otherwise specified, preferably 1 or more, more preferably 2 or more, even more preferably 3 or more, 4 or more, 5 or more, or 6 or more, and preferably 50 or less, more preferably 40 or less, even more preferably 30 or less, 20 or less, 18 or less, 16 or less, 14 or less, or 12 or less. The number of heteroatoms and the number of carbon atoms therein do not include the number of heteroatoms and the number of carbon atoms of substituents.

[0015] As used herein, the term "heteroalkyl group" refers to a monovalent saturated hydrocarbon group containing a heteroatom, and may be linear or branched. The number of heteroatoms and carbon atoms in the heteroalkyl group are as described for the "heteroatom-containing hydrocarbon group." The number of heteroatoms is preferably 1 to 6, more preferably 1 to 4, or 1 or 2, and the number of carbon atoms is preferably 1 to 12, more preferably 1 to 10, and even more preferably 1 to 8, or 1 to 6. In the heteroalkyl group, the heteroatom is preferably one or more selected from the group consisting of oxygen, nitrogen, sulfur, and silicon atoms. For example, the heteroatom may be present as a heteroatom such as -O- or -S-, or as a heteroatom-containing group such as -C(=O)-, -S(=O)-, -S(=O)2-, -N(R)-, -Si(R)2-, or a combination thereof, or a combination thereof with -O- or -S-. When the heteroalkyl group contains two or more heteroatoms, they may be the same or different. As mentioned above, the heteroatom may be present between the carbon-carbon bond or may be bonded to a terminal carbon. Examples of the heteroalkyl group in which a heteroatom is bonded to a terminal carbon include an alkyloxy group (alkoxy group), an alkylthio group, an alkylsulfonyl group, an alkylsulfinyl group, an alkylcarbonyl group, an alkylamino group, an alkylsilyl group, an alkyloxycarbonyl group, and an alkylcarbonyloxy group; and examples of the heteroatom in which a heteroatom is present between the carbon-carbon bond include monovalent saturated hydrocarbon groups interrupted by one or more divalent groups selected from the group consisting of -O-, -S-, -C(=O)-, -S(=O)-, -S(=O)2-, -N(R)-, -Si(R)2-, and combinations thereof.

[0016] As used herein, the term "heteroalkenyl group" refers to a monovalent unsaturated hydrocarbon group containing a heteroatom and having one carbon-carbon double bond, and may be either linear or branched. The number of heteroatoms and the number of carbon atoms in the heteroalkenyl group are as described for the "heteroatom-containing hydrocarbon group." The number of heteroatoms is preferably 1 to 6, more preferably 1 to 4, or 1 or 2, and the number of carbon atoms is preferably 2 to 12, more preferably 2 to 10, even more preferably 2 to 8, or 2 to 6. Suitable types of heteroatoms and their locations in the group are as described for the "heteroalkyl group" above. Suitable examples of the heteroalkenyl group can be found by replacing "alkyl" with "alkenyl" and "monovalent saturated hydrocarbon group" with "monovalent unsaturated hydrocarbon group having one carbon-carbon double bond" in the groups exemplified above for the "heteroalkyl group."

[0017] As used herein, the term "heteroalkynyl group" refers to a monovalent unsaturated hydrocarbon group containing a heteroatom and having one carbon-carbon triple bond, and may be either linear or branched. The number of heteroatoms and the number of carbon atoms in the heteroalkynyl group are as described for the "heteroatom-containing hydrocarbon group." The number of heteroatoms is preferably 1 to 6, more preferably 1 to 4, or 1 or 2, and the number of carbon atoms is preferably 2 to 12, more preferably 2 to 10, and even more preferably 2 to 8, or 2 to 6. Suitable types of heteroatoms and their locations in the group are as described for the "heteroalkyl group" above. Suitable examples of the heteroalkynyl group can be found by replacing "alkyl" with "alkynyl" and "monovalent saturated hydrocarbon group" with "monovalent unsaturated hydrocarbon group having one carbon-carbon triple bond" in the groups exemplified above for the "heteroalkyl group."

[0018] As used herein, the term "heteroalkapolyenyl group" refers to a monovalent unsaturated hydrocarbon group containing a heteroatom and having two or more carbon-carbon double bonds, and may be either linear or branched. The number of heteroatoms and the number of carbon atoms in the heteroalkapolyenyl group are as described for the "heteroatom-containing hydrocarbon group." The number of heteroatoms is preferably 1 to 6, more preferably 1 to 4, or 1 or 2, and the number of carbon atoms is preferably 3 to 12, more preferably 3 to 10, even more preferably 3 to 8, or 3 to 6. Suitable examples of the heteroalkapolyenyl group can be found by replacing "alkyl" with "alkapolyenyl" and "monovalent saturated hydrocarbon group" with "monovalent unsaturated hydrocarbon group having two or more carbon-carbon double bonds" in the groups exemplified above for the "heteroalkyl group."

[0019] As used herein, the term "monovalent carbocyclic group" refers to a group in which one hydrogen atom on a carbocyclic ring has been removed from a cyclic hydrocarbon. Here, the carbocyclic ring may be either a saturated or unsaturated carbocyclic ring, and may be a monocyclic carbocyclic ring, a fused polycyclic carbocyclic ring formed by condensing two or more monocyclic carbocyclic rings, or a spirocyclic carbocyclic ring formed by spiro-bonding two or more monocyclic carbocyclic rings. The number of carbon atoms in the monovalent carbocyclic group is as described for the "hydrocarbon group," but is preferably 3 to 20, more preferably 3 to 15, even more preferably 3 to 14, 3 to 12, 3 to 10, 3 to 7, or 3 to 6. Examples of the monovalent carbocyclic group include monovalent saturated carbocyclic groups such as cycloalkyl groups; and monovalent unsaturated carbocyclic groups such as cycloalkenyl groups, cycloalkynyl groups, and cycloalkapolyenyl groups. Among cycloalkapolyenyl groups, those that exhibit aromaticity according to Huckel's rule, in which the number of electrons in the π electron system on the ring is 4p+2 (p is a natural number), are also called "aryl groups."

[0020] As used herein, the term "monovalent heterocyclic group" refers to a group obtained by removing one hydrogen atom from a heterocyclic ring of a heterocyclic compound. Here, the heterocycle may be either a saturated or unsaturated heterocycle, and may be any of a monocyclic heterocycle, a fused polycyclic heterocycle, and a spirocyclic heterocycle. The number of heteroatoms and carbon atoms of the monovalent heterocyclic group are as described for the "heteroatom-containing hydrocarbon group." The number of heteroatoms is preferably 1 to 10, more preferably 1 to 8, even more preferably 1 to 6, or even 1 to 4. The number of ring members of the monovalent heterocyclic group is preferably 5 to 20, more preferably 5 to 15, even more preferably 5 to 12, or even 5 to 10. In the monovalent heterocyclic group, the heteroatom is preferably one or more selected from the group consisting of an oxygen atom, a nitrogen atom, and a sulfur atom.

[0021] As described above, the term "heteroatom-containing hydrocarbon group" in this specification also encompasses a monovalent group formed by bonding a divalent group selected from the group consisting of -O-, -S-, -C(=O)-, -S(=O)-, -S(=O)2-, -N(R)-, -Si(R)2-, and combinations thereof to a bond of a monovalent carbocyclic group (hereinafter, for convenience, also referred to as "monovalent group A"). Here, the monovalent carbocyclic group, including its type and number of carbon atoms, is as described above. Examples of the monovalent group A include a cycloalkyloxy group, a cycloalkylthio group, a cycloalkylsulfonyl group, a cycloalkylsulfinyl group, a cycloalkylcarbonyl group, a cycloalkylamino group, and a cycloalkylsilyl group, which contain a monovalent saturated carbocyclic group. The monovalent group A also includes, for example, monovalent unsaturated carbocyclic groups containing an aryl group, such as aryloxy groups, arylcarbonyl groups, arylamino groups, arylsilyl groups, aryloxycarbonyl groups, arylcarbonyloxy groups, etc. Monovalent unsaturated carbocyclic groups containing other unsaturated carbocyclic groups such as cycloalkenyl groups can be applied by replacing "aryl" with "cycloalkenyl" in the above.

[0022] As described above, the term "heteroatom-containing hydrocarbon group" in this specification also encompasses a monovalent group formed by bonding a divalent group selected from the group consisting of -O-, -S-, -C(=O)-, -S(=O)-, -S(=O)2-, -N(R)-, -Si(R)2-, and combinations thereof to a bond of a monovalent heterocyclic group (hereinafter, for convenience, also referred to as "monovalent group B"). Here, the monovalent heterocyclic group, including its type, number of heteroatoms, and number of carbon atoms, is as described above. Examples of the monovalent group B include a heterocyclic oxy group, a heterocyclic thio group, a heterocyclic sulfonyl group, a heterocyclic sulfinyl group, a heterocyclic carbonyl group, a heterocyclic amino group, a heterocyclic silyl group, a heterocyclic oxycarbonyl group, a heterocyclic carbonyloxy group, a heterocyclic amido group, a heterocyclic imido group, a heterocyclic ureido group, a heterocyclic sulfonylamino group, a heterocyclic oxycarbonylamino group, and a heterocyclic silyloxy group. When the heterocycle exhibits aromaticity, examples of the monovalent group B can be obtained by replacing "heterocycle" with "heteroaryl" in the above.

[0023] As used herein, the term "aromatic ring" refers to a ring conforming to Hückel's rule, in which the number of electrons in the π-electron system on the ring is 4p+2 (p is a natural number), and includes monocyclic aromatic rings and fused polycyclic aromatic rings in which two or more monocyclic aromatic rings are fused together. The aromatic ring may be an aromatic carbocyclic ring having only carbon atoms as ring-constituting atoms, or an aromatic heterocyclic ring having heteroatoms such as oxygen, nitrogen, or sulfur atoms in addition to carbon atoms as ring-constituting atoms. As used herein, unless otherwise specified, the number of carbon atoms in the aromatic ring is preferably 3 or more, more preferably 4 or more or 5 or more, and even more preferably 6 or more, with the upper limit being preferably 24 or less, more preferably 18 or less or 14 or less, and even more preferably 10 or less. The number of carbon atoms does not include the number of carbon atoms of substituents. Examples of the aromatic ring include monocyclic aromatic rings such as a benzene ring, a furan ring, a thiophene ring, a pyrrole ring, a pyrazole ring, an oxazole ring, an isoxazole ring, a thiazole ring, an imidazole ring, a pyridine ring, a pyridazine ring, a pyrimidine ring, and a pyrazine ring; and fused polycyclic aromatic rings in which two or more monocyclic aromatic rings are fused together, such as a naphthalene ring, an anthracene ring, a phenanthrene ring, a benzofuran ring, an isobenzofuran ring, an indole ring, an isoindole ring, a benzothiophene ring, a benzimidazole ring, an indazole ring, a benzoxazole ring, a benzisoxazole ring, a benzothiazole ring, a quinoline ring, an isoquinoline ring, a quinoxaline ring, an acridine ring, a quinazoline ring, a cinnoline ring, and a phthalazine ring.

[0024] As used herein, the term "optionally substituted" in reference to a compound or group means both a case where the hydrogen atoms of the compound or group are not substituted with substituents, and a case where some or all of the hydrogen atoms of the compound or group are substituted with substituents.

[0025] In this specification, unless otherwise specified, the term "substituent" means a halogen atom, an alkyl group, an alkenyl group, a cycloalkyl group, an alkoxy group, a cycloalkyloxy group, an aryl group, an aryloxy group, an arylalkyl group, an arylalkoxy group, a monovalent heterocyclic group, an alkylidene group, an acyl group, an acyloxy group, an amino group, a silyl group, a carboxy group, a sulfo group, a cyano group, a nitro group, a mercapto group, or an oxo group.

[0026] Examples of halogen atoms used as substituents include fluorine, chlorine, bromine, and iodine atoms. The alkyl group used as a substituent may be either linear or branched. The alkyl group preferably has 1 to 12 carbon atoms, more preferably 1 to 6, and even more preferably 1 to 3. The alkenyl group used as a substituent may be either linear or branched. The alkenyl group preferably has 2 to 12 carbon atoms, more preferably 2 to 6, and even more preferably 2 or 3. The cycloalkyl group used as a substituent preferably has 3 to 12 carbon atoms, more preferably 3 to 6. The alkoxy group used as a substituent may be either linear or branched. The alkoxy group preferably has 1 to 12 carbon atoms, more preferably 1 to 6. The cycloalkyloxy group used as a substituent preferably has 3 to 12 carbon atoms, more preferably 3 to 6. The aryl group used as a substituent preferably has 6 to 14 carbon atoms, more preferably 6 to 10. The aryloxy group used as a substituent preferably has 6 to 14 carbon atoms, more preferably 6 to 10. The arylalkyl group used as a substituent preferably has 7 to 15 carbon atoms, more preferably 7 to 11. The arylalkoxy group used as a substituent preferably has 7 to 15 carbon atoms, more preferably 7 to 11. The monovalent heterocyclic group used as a substituent refers to a group obtained by removing one hydrogen atom from the heterocycle of a heterocyclic compound. The monovalent heterocyclic group preferably has 3 to 15 carbon atoms, more preferably 3 to 9 carbon atoms. The monovalent heterocyclic group also includes a monovalent aromatic heterocyclic group (heteroaryl group). The alkylidene group used as a substituent refers to a group obtained by removing two hydrogen atoms from the same carbon atom of an alkane. The alkylidene group preferably has 1 to 12 carbon atoms, more preferably 1 to 6 carbon atoms, and particularly preferably 1 to 3 carbon atoms. The acyl group used as a substituent refers to a group represented by the formula: -C(=O)-R (wherein R is an alkyl group or an aryl group). The alkyl group represented by R may be linear or branched. The acyl group preferably has 2 to 13 carbon atoms, and more preferably 2 to 7 carbon atoms.The acyloxy group used as a substituent is a group represented by the formula: -O-C(=O)-R (wherein R has the same meaning as described above). The number of carbon atoms of the acyloxy group is preferably 2 to 13, more preferably 2 to 7. The above-mentioned substituent may further have a substituent (which may be referred to as a "secondary substituent"). As the secondary substituent, the same ones as the above-mentioned substituents may be used unless otherwise specified.

[0027] In this specification, the term "C p ~C q " (where p and q are positive integers and p < q) represents that the number of carbon atoms of the organic group described immediately after this term is p to q. For example, "C1-C6 alkyl group" indicates an alkyl group having 1 to 6 carbon atoms, and "C6-C 10 cycloalkyl group" indicates a cycloalkyl group having 6 to 10 carbon atoms.

[0028] Hereinafter, the present invention will be described in detail with reference to embodiments and examples. However, the present invention is not limited to the following embodiments and examples, and can be arbitrarily modified and implemented without departing from the scope of the claims of the present invention and its equivalent scope.

[0029] [Resin Composition] The resin composition of the present invention is a polyfunctional epoxy resin containing four or more monovalent organic groups having an epoxy group (hereinafter referred to as "organic group X") in the molecule, a polyfunctional epoxy resin containing an aromatic ring having two or more organic groups X per constituent ring, and an active ester resin.

[0030] As mentioned above, resin compositions using active ester resins have room for improvement in terms of lowering the viscosity, and when an insulating layer is formed using such a resin composition, the insulating layer tends to have poor adhesion to a conductor layer after exposure to a high-temperature, high-humidity environment. Furthermore, in order to achieve favorable cured product properties, such as better dielectric properties and a low coefficient of thermal expansion, active ester resins and inorganic fillers are sometimes incorporated at high levels. However, it has been confirmed that the deterioration in viscosity characteristics and the deterioration in adhesion to a conductor layer after exposure to a high-temperature, high-humidity environment become more pronounced in such cases.

[0031] In contrast, the present invention uses a polyfunctional epoxy resin containing four or more monovalent organic groups X having epoxy groups in the molecule, and a polyfunctional epoxy resin containing an aromatic ring with two or more organic groups X per constituent ring, and even when a high amount of active ester resin or a high amount of inorganic filler is blended, it is possible to obtain a cured product that exhibits low viscosity and good adhesion to a conductor layer when exposed to a high-temperature, high-humidity environment.Furthermore, it has been confirmed that the use of the above specific polyfunctional epoxy resin as the epoxy resin in the present invention results in better heat resistance of the resulting cured product.

[0032] The resin composition of the present invention may contain other epoxy resins as long as it contains the above-mentioned specific polyfunctional epoxy resin. Hereinafter, the above-mentioned specific polyfunctional epoxy resin will be referred to as "(A-1) a polyfunctional epoxy resin containing four or more monovalent organic groups X having an epoxy group in the molecule, and containing an aromatic ring having two or more organic groups X per constituent ring" or simply "component (A-1)." The other epoxy resin will be referred to as "(A-2) other epoxy resin" or simply "component (A-2)." Furthermore, component (A-1) and component (A-2) will be collectively referred to as "(A) epoxy resin" or simply "epoxy resin" or "component (A)."

[0033] Each component will be described below.

[0034] <(A) Epoxy resin> The resin composition of the present invention is characterized in that it contains an epoxy resin as component (A), and the epoxy resin contains (A-1) a polyfunctional epoxy resin containing four or more monovalent organic groups X having an epoxy group in the molecule, and containing an aromatic ring having two or more organic groups X per constituent ring.

[0035] In the component (A-1), the organic group X is not particularly limited as long as it is a monovalent organic group having an epoxy group. However, from the viewpoint of being able to realize a resin composition that exhibits low viscosity and being able to realize a cured product that exhibits even better adhesion to a conductor layer when exposed to a high-temperature, high-humidity environment, it is preferable that the organic group X be a monovalent organic group having an epoxy group. a hydrocarbon group which has an epoxy group and may have a substituent, or a heteroatom-containing hydrocarbon group which has an epoxy group and may have a substituent, is preferred; Preferred are an alkyl group which has an epoxy group and may have a substituent, a cycloalkyl group which has an epoxy group and may have a substituent, an alkoxy group which has an epoxy group and may have a substituent, a cycloalkyloxy group which has an epoxy group and may have a substituent, an alkyloxycarbonyl group which has an epoxy group and may have a substituent, or a cycloalkyloxycarbonyl group which has an epoxy group and may have a substituent.

[0036] Among these, from the viewpoints of being able to realize a resin composition that exhibits low viscosity even when a high content of an active ester resin or an inorganic filler is incorporated, and being able to realize a cured product that exhibits good adhesion to a conductor layer when exposed to a high-temperature, high-humidity environment, the organic group X is more preferably an alkyl group that has an epoxy group and may have a substituent, an alkoxy group that has an epoxy group and may have a substituent, or an alkyloxycarbonyl group that has an epoxy group and may have a substituent.

[0037] Here, the substituent that the hydrocarbon group or heteroatom-containing hydrocarbon group in the organic group X may have is as described above, but from the viewpoint of further enjoying the effects of the present invention, a halogen atom, an alkyl group, an alkoxy group, or an aryl group is preferred, and a fluorine atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or an aryl group having 6 to 10 carbon atoms is more preferred.

[0038] The organic group X preferably has 3 to 30 carbon atoms, more preferably 3 to 20 carbon atoms, and even more preferably 3 to 15, 3 to 10, 3 to 8, or 3 to 6 carbon atoms, including the number of carbon atoms in the epoxy group and the substituent.

[0039] From the viewpoint of being able to enjoy the effects of the present invention more effectively, the organic group X is preferably a C1-C6 alkyl group having an epoxy group, a C1-C6 alkyloxy group having an epoxy group, or a C1-C6 alkyloxycarbonyl group having an epoxy group, and particularly preferably a glycidyl group, a glycidyl ether group, or a glycidyl ester group.

[0040] In order to obtain the effects of the present invention more effectively, it is preferable that each organic group X has one epoxy group.

[0041] Component (A-1) contains four or more of the organic groups X in the molecule. From the viewpoints of realizing a resin composition with even lower viscosity and a cured product that exhibits even better adhesion to a conductor layer when exposed to a high-temperature, high-humidity environment, the upper limit of the number of organic groups X in the molecule of component (A-1) is preferably 20 or less, more preferably 10 or less, even more preferably 8 or less, or 6 or less. In particular, from the viewpoints of realizing a resin composition with even lower viscosity and a cured product that exhibits even better adhesion to a conductor layer when exposed to a high-temperature, high-humidity environment, even when a high content of active ester resin or inorganic filler is incorporated, the content of epoxy resins containing four organic groups X in the molecule (i.e., tetrafunctional epoxy resins) is preferably 50 mol % or more, more preferably 60 mol % or more, 70 mol % or more, 80 mol % or more, or 90 mol % or more, when the entire component (A-1) is taken as 100 mol %.

[0042] The component (A-1) contains an aromatic ring in the molecule having two or more organic groups X per constituent ring. As described above, the aromatic ring having two or more organic groups X may be either a monocyclic aromatic ring or a fused polycyclic aromatic ring. Here, "an aromatic ring having two or more organic groups X per constituent ring" refers to a monocyclic aromatic ring having two or more organic groups X when the aromatic ring is a monocyclic aromatic ring, or to a fused polycyclic aromatic ring having 2N or more organic groups X when the aromatic ring is a fused polycyclic aromatic ring formed by the condensation of N (N≧2) monocyclic aromatic rings. By using such a component (A-1), the resin composition of the present invention can produce a cured product that exhibits low viscosity and good adhesion to a conductor layer when exposed to a high-temperature, high-humidity environment.

[0043] From the viewpoint of being able to realize a resin composition with low viscosity even when a high content of an active ester resin or an inorganic filler is blended, and being able to realize a cured product that exhibits good adhesion to a conductor layer when exposed to a high-temperature, high-humidity environment, the aromatic ring having two or more organic groups X is preferably a monocyclic aromatic ring, more preferably a monocyclic aromatic ring having 3 to 10 carbon atoms, and even more preferably a monocyclic aromatic carbocyclic ring having 3 to 10 carbon atoms.

[0044] In particular, from the viewpoint of being able to realize a resin composition with even lower viscosity even when a high content of active ester resin or inorganic filler is used, and being able to realize a cured product that exhibits even better adhesion to a conductor layer when exposed to a high-temperature, high-humidity environment, it is preferable that component (A-1) contains a benzene ring having two or more organic groups X in the molecule, and it is more preferable that component (A-1) contains two or more benzene rings having two or more organic X in the molecule.

[0045] In a preferred embodiment, the component (A-1) includes a structure represented by the following formula (1):

[0046] [ka] (In formula (1), Each X independently represents a monovalent organic group having an epoxy group, R S each independently represents a substituent, * represents a bond, n1 represents an integer of 2 or greater, n2 represents an integer equal to or greater than 0, Here, n1 and n2 satisfy n1+n2≦5.

[0047] In formula (1), a benzene ring is clearly shown. This benzene ring corresponds to the "aromatic ring" having two or more organic groups X, as described above in relation to component (A-1).

[0048] In formula (1), each X independently represents a monovalent organic group having an epoxy group, and suitable examples thereof are as described above for the organic group X. Among these, each X independently preferably represents an alkyl group having an epoxy group and optionally having a substituent, an alkoxy group having an epoxy group and optionally having a substituent, or an alkyloxycarbonyl group having an epoxy group and optionally having a substituent, further preferably a C1-C6 alkyl group having an epoxy group, a C1-C6 alkyloxy group having an epoxy group, or a C1-C6 alkyloxycarbonyl group having an epoxy group, and particularly preferably a glycidyl group, a glycidyl ether group, or a glycidyl ester group.

[0049] In formula (1), R S R each independently represents a substituent. S The substituent represented by the formula (I) is as described above, but from the viewpoint of being able to enjoy the effects of the present invention more effectively, it is preferably one or more selected from a halogen atom, a hydrocarbon group, and an alkoxy group, more preferably one or more selected from a fluorine atom, a hydrocarbon group having 1 to 12 carbon atoms, and an alkoxy group having 1 to 10 carbon atoms, and even more preferably one or more selected from a fluorine atom, an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 10 carbon atoms, an arylalkyl group having 7 to 12 carbon atoms, an unsaturated aliphatic hydrocarbon group having 2 to 6 carbon atoms, and an alkoxy group having 1 to 6 carbon atoms.

[0050] In formula (1), n1 represents an integer of 2 or more, and n2 represents an integer of 0 or more, where n1 and n2 satisfy n1+n2≦5.

[0051] To obtain the effects of the present invention more effectively, n1 is preferably an integer of 2 to 4, more preferably 2 or 3. Furthermore, n2 is preferably an integer of 0 to 3, more preferably an integer of 0 to 2, and even more preferably 0 or 1.

[0052] From the viewpoint of realizing a resin composition with even lower viscosity even when a high content of an active ester resin or inorganic filler is incorporated, and realizing a cured product that exhibits even better adhesion to a conductor layer when exposed to a high-temperature, high-humidity environment, it is preferable that the component (A-1) be represented by the following formula (2):

[0053] [ka] (In formula (2), X, R S , n1 and n2 are the same as above, L represents a single bond or a divalent linking group.

[0054] Formula (2) shows two benzene rings. Each of these two benzene rings corresponds to the "aromatic ring" having two or more organic groups X, as described above for component (A-1). In other words, the polyfunctional epoxy resin represented by formula (2) contains two benzene rings having two or more organic groups X in the molecule.

[0055] In formula (2), X, R S , n1 and n2 are the same as above, and their preferred examples and ranges are as described above.

[0056] In formula (2), L represents a single bond or a divalent linking group. From the viewpoint of further enjoying the effects of the present invention, the divalent linking group represented by L is preferably selected from the group consisting of divalent hydrocarbon groups having 1 to 10 carbon atoms, which may have a substituent, oxygen atoms, sulfonyl groups, carbonyl groups, carbonate groups, and divalent groups consisting of combinations thereof. The divalent linking group represented by L preferably has 1 to 30 carbon atoms, more preferably 1 to 20 or 1 to 15 carbon atoms.

[0057] The divalent hydrocarbon group for L includes a divalent aliphatic hydrocarbon group and a divalent aromatic hydrocarbon group, such as an alkylene group, a cycloalkylene group, an alkenylene group, a cycloalkenylene group, an alkapolyenylene group (the number of double bonds is preferably 2 to 10, more preferably 2 to 6, even more preferably 2 to 4, and still more preferably 2), an arylene group, etc., with an alkylene group, a cycloalkylene group, an alkenylene group, a cycloalkenylene group, and an arylene group being preferred, and an alkylene group, a cycloalkylene group, and an arylene group being more preferred.

[0058] The alkylene group in L may be either linear or branched, and the number of carbon atoms therein is more preferably 1 to 6, and even more preferably 1 to 4 or 1 to 3. The number of carbon atoms in the substituent is not included in the number of carbon atoms. Examples of the alkylene group include a methylene group, an ethylene group, a propylene group, a butylene group, a pentylene group, and a hexylene group.

[0059] The number of carbon atoms in the cycloalkylene group for L is more preferably 3 to 10, 4 to 10, or 6 to 10. The number of carbon atoms of the substituent is not included in this number of carbon atoms. Examples of the cycloalkylene group include a cyclopropylene group, a cyclobutylene group, a cyclopentylene group, a cyclohexylene group, a decahydronaphthalene group, a norbornanylene group, a dicyclopentanylene group, and an adamantanylene group.

[0060] The alkenylene group in L may be either linear or branched, and the number of carbon atoms therein is more preferably 2 to 6, and even more preferably 2 to 4. The number of carbon atoms in the substituent is not included in this number of carbon atoms. Examples of the alkenylene group include an ethenylene group, a propenylene group, a butenylene group, a pentenylene group, and a hexenylene group.

[0061] The number of carbon atoms in the cycloalkenylene group for L is more preferably 3 to 10, 4 to 10, or 6 to 10. The number of carbon atoms of the substituent is not included in this number of carbon atoms. Examples of the cycloalkenylene group include a cyclopropenylene group, a cyclobutenylene group, a cyclopentenylene group, a cyclohexenylene group, and a norbornenylene group.

[0062] The number of carbon atoms in the arylene group in L is more preferably 6 to 10. The number of carbon atoms in the substituent is not included in this number of carbon atoms. Examples of the arylene group include a phenylene group, a naphthylene group, and an indandiyl group.

[0063] From the viewpoint of being able to realize a resin composition with even lower viscosity even when a high content of an activated ester resin or an inorganic filler is incorporated, and being able to realize a cured product that exhibits even better adhesion to a conductor layer when exposed to a high-temperature, high-humidity environment, the divalent linking group represented by L is preferably a divalent hydrocarbon group having 1 to 10 carbon atoms, which may have a substituent, a sulfonyl group, a carbonyl group, or a divalent group consisting of a combination thereof, and among these, an alkylene group having 1 to 6 carbon atoms, which may have a substituent, a cycloalkylene group having 6 to 10 ... More preferably, it is a divalent group consisting of an alkenylene group having 2 to 6 carbon atoms, a cycloalkenylene group having 6 to 10 carbon atoms which may have a substituent, an arylene group having 6 to 10 carbon atoms which may have a substituent, a sulfonyl group, a carbonyl group, or a combination thereof, and even more preferably, it is an alkylene group having 1 to 6 carbon atoms which may have a substituent, a cycloalkylene group having 6 to 10 carbon atoms which may have a substituent, an arylene group having 6 to 10 carbon atoms which may have a substituent, a sulfonyl group, a carbonyl group, or a combination thereof. Suitable examples of divalent groups consisting of a combination include C1-C6 alkylene-C6 ... 10 Arylene-C1-C6 alkylene group, C1-C6 alkylene-C6-C 10 Arylene-C6~C 10In the case of a divalent group formed by combining these, the alkylene group or arylene group may have a suitable range of carbon atoms, and the group may have a substituent, as described above.

[0064] The substituents that the divalent hydrocarbon group in L may have are as described above. Among these, the substituent is preferably one or more selected from a halogen atom, an alkyl group, and an aryl group, and more preferably one or more selected from a fluorine atom, an alkyl group having 1 to 6 carbon atoms, and an aryl group having 6 to 10 carbon atoms.

[0065] Examples of epoxy resins represented by formula (2) that are particularly suitable from the viewpoint of realizing a resin composition with even lower viscosity even when a high content of an active ester resin or an inorganic filler is included, and realizing a cured product that exhibits even better adhesion to a conductor layer when exposed to a high-temperature, high-humidity environment, are shown below.

[0066] In one preferred embodiment, in formula (2), X's each independently represent an alkyl group which has an epoxy group and may have a substituent, an alkoxy group which has an epoxy group and may have a substituent, or an alkyloxycarbonyl group which has an epoxy group and may have a substituent; R S each independently represents a halogen atom, a hydrocarbon group, or an alkoxy group; L represents (i) a single bond, or (ii) a divalent hydrocarbon group having 1 to 10 carbon atoms, a sulfonyl group, a carbonyl group, or a divalent group consisting of a combination thereof, which may have a substituent, wherein the substituent is one or more selected from a halogen atom, an alkyl group, and an aryl group; n1 each independently represents 2 or 3; Each n2 independently represents an integer of 0 to 2.

[0067] In a more preferred embodiment, in formula (2), X's each independently represent a C1-C6 alkyl group having an epoxy group, a C1-C6 alkyloxy group having an epoxy group, or a C1-C6 alkyloxycarbonyl group having an epoxy group; R S each independently represents a fluorine atom, an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 10 carbon atoms, an arylalkyl group having 7 to 12 carbon atoms, an unsaturated aliphatic hydrocarbon group having 2 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms; L represents (i) a single bond, or (ii) a divalent group selected from an alkylene group having 1 to 6 carbon atoms which may have a substituent, a cycloalkylene group having 6 to 10 carbon atoms which may have a substituent, an arylene group having 6 to 10 carbon atoms which may have a substituent, a sulfonyl group, a carbonyl group, or a combination thereof, wherein the substituent is one or more selected from a fluorine atom, an alkyl group having 1 to 6 carbon atoms, and an aryl group having 6 to 10 carbon atoms; n1 each independently represents 2 or 3; Each n2 independently represents 0 or 1.

[0068] From the viewpoint of being able to realize a resin composition with even lower viscosity and a cured product that exhibits even better adhesion to a conductor layer when exposed to a high-temperature, high-humidity environment, the epoxy group equivalent of component (A-1) is preferably 90 g / eq. or more, more preferably 100 g / eq. or more, 105 g / eq. or more, or 110 g / eq. or more, and the upper limit is preferably 500 g / eq. or less, more preferably 400 g / eq. or less, 300 g / eq. or less, or 200 g / eq. The epoxy group equivalent is the mass of an epoxy resin containing one equivalent of epoxy groups, and can be measured in accordance with JIS K7236.

[0069] From the viewpoint of realizing a resin composition with even lower viscosity and a cured product that exhibits even better adhesion to a conductor layer when exposed to a high-temperature, high-humidity environment, the molecular weight (weight molecular weight Mw if the molecular weight has a distribution) of component (A-1) is preferably 3,000 or less, more preferably 2,000 or less, and even more preferably 1,000 or less, 800 or less, or 600 or less. There is no particular restriction on the lower limit of the molecular weight, and it can be, for example, 300 or more, 320 or more, etc. The molecular weight can be measured as a polystyrene-equivalent value by gel permeation chromatography (GPC).

[0070] In a preferred embodiment, component (A-1) is liquid at a temperature of 20° C. In the present invention, the term "liquid" used with respect to epoxy resins refers to those determined to be liquid at 20° C. after undergoing a confirmation test in accordance with the "Method for Confirming Liquidity" in Appendix 2 of the Ministerial Ordinance on the Testing and Properties of Hazardous Materials (Ministry of Home Affairs Ordinance No. 1 of 1989) (see also Japanese Patent No. 5624184 for details of the test).

[0071] An example of the synthesis procedure for the component (A-1) will be shown below in relation to the synthesis of a particularly preferred epoxy resin represented by formula (2).

[0072] In one embodiment, the component (A-1) is (x1) a compound represented by the following general formula (x1), (x2) one or more selected from epihalohydrins and organic peracids; is the reactant of

[0073] [ka] (In the formula, R S , L, n2 are the same as above, R 1 each independently represents a single bond, a carbonyl group, a divalent hydrocarbon group which may have a substituent, or a divalent hydrocarbon group which may have a heteroatom, R 2each independently represents a monovalent unsaturated hydrocarbon group which may have a substituent, n1a and n1b represent integers that satisfy n1a+n1b=n1, where n1 is the same as above.

[0074] -(x1) A compound represented by general formula (x1)- The compound represented by general formula (x1) (hereinafter simply referred to as "compound (x1)") may be appropriately determined to achieve the desired structure of component (A-1). Suitable examples of the structure of component (A-1), such as the structure represented by formula (2), are as described above. Compound (x1) has two organic groups X per benzene ring (i.e., both n1s are 2), one of the organic groups X is a glycidyl group and the other is a glycidyl ether group, both n2s are 0, and L is a single bond. Diallyldihydroxybiphenyls such as 3,3'-diallyl-4,4'-dihydroxybiphenyl and honokiol (3',5-diallyl-2,4'-dihydroxybiphenyl) may be used to achieve the structure of formula (2). Furthermore, as a compound having two organic groups X per benzene ring (i.e., both n1s are 2), one of the organic groups X is a glycidyl group and the other is a glycidyl ether group, both n2s are 0, and L is a methylene group, diallyl bisphenol F such as 2,2'-diallyl bisphenol F may be used as a compound having two organic groups X per benzene ring (i.e., both n1s are 2), one of the organic groups X is a glycidyl group and the other is a glycidyl ether group, both n2s are 0, and L is a propane group. Diallyl bisphenol A such as 2,2'-diallyl bisphenol A may be used as a compound that provides the structure of formula (2) in which L is a -2,2-diyl group, and diallyl dihydroxydiphenyl sulfone such as 3,3'-diallyl-4,4'-dihydroxydiphenyl sulfone may be used as a compound that provides the structure of formula (2) in which L has two organic groups X per benzene ring (i.e., both n1s are 2), one of the organic groups X is a glycidyl group and the other is a glycidyl ether group, both n2s are 0, and L is a sulfonyl group.Furthermore, as a compound having two organic groups X per benzene ring (i.e., both n1s are 2), the organic groups X are all glycidyl ether groups, both n2s are 0, and L is a carbonyl group, a tetrahydroxybenzophenone such as 2,2',4,4'-tetrahydroxybenzophenone may be used as a compound having two organic groups X per benzene ring (i.e., both n1s are 2), the organic groups X are all glycidyl groups, both n2s are 0, and L is a carbonyl group, a tetraarylbenzophenone such as 2,2',4,4'-tetraarylbenzophenone may be used as a compound having two organic groups X per benzene ring (i.e., both n1s are 2), the organic groups X are all glycidyl groups, both n2s are 0, and L is a carbonyl group, Furthermore, a tetracarboxybiphenyl such as 2,2',4,4'-tetracarboxybiphenyl may be used as a compound having two organic groups X per benzene ring (i.e., both n1s are 2), all of the organic groups X are glycidyl ester groups, both n2s are 0, and L is a single bond, which gives rise to the structure of formula (2).

[0075] In the above, R in formula (x1) 1 is a single bond or a carbonyl group, and R 2 Although the embodiment in which R is an allyl group has been described, 1 is a divalent hydrocarbon group such as a C1-C6 alkylene group, or a divalent heteroatom-containing hydrocarbon group such as a C1-C6 alkyleneoxy group or a carbonyl C1-C6 alkylene group, may be used to realize an embodiment in which the organic group X is a heteroatom-containing hydrocarbon group having an epoxy group, and R 2 An embodiment in which the organic group X is an epoxy group-containing hydrocarbon group other than a glycidyl group, such as an epoxypropylene group, may be realized by using a compound (x1) in which n is an unsaturated hydrocarbon group other than an allyl group. Also, an embodiment in which n is 1 or greater may be realized by using a compound (x1) having a substituent.

[0076] -(x2) one or more selected from epihalohydrin and organic peracid - As the epihalohydrin (x2), epichlorohydrin or epibromohydrin may be used. The epihalohydrin is a hydroxyl group or a carboxyl group (i.e., -R 1 The ether or ester reacts with the —OH moiety to form an ether or ester, which, when heated in the presence of an alkali metal hydroxide, generates an epoxy ring (epoxidation reaction). The organic peracid (x2) may be peracetic acid or perbenzoic acid. The organic peracid is a compound that reacts with the olefin double bond of the compound (x1) (i.e., R 2 The epoxy ring is formed by oxidizing (oxiranating) the hydroxyl group (part) of the hydroxyl group.

[0077] --Reaction of compound (x1) with epihalohydrin (x2)-- When compound (x1) has a hydroxy group or a carboxy group (when n1a in formula (x1) is 1 or more), compound (x1) is reacted with epihalohydrin (x2). The reaction of compound (x1) with epihalohydrin (x2) may be carried out by a conventionally known epoxidation reaction using a hydroxy compound or a carboxy compound and epihalohydrin. The reaction may be carried out in a solvent-free system without using a solvent, or in an organic solvent system using an organic solvent. Examples of organic solvents used in the reaction include ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; acetate ester solvents such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate, and carbitol acetate; carbitol solvents such as cellosolve and butyl carbitol; aromatic hydrocarbon solvents such as toluene and xylene; amide solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone; and halogenated hydrocarbon solvents such as dihalomethanes, trihalomethanes, and tetrahalomethanes. The organic solvents may be used alone or in combination of two or more.

[0078] A base may be used in the reaction. Examples of the base include alkali metal hydroxides such as sodium hydroxide (caustic soda) and potassium hydroxide; and tertiary amines such as triethylamine, pyridine, and N,N-dimethyl-4-aminopyridine (DMAP). The base may be used alone or in combination of two or more. A condensing agent or a phase transfer catalyst may also be used in the reaction. Any conventionally known bases may be used.

[0079] The reaction temperature is not particularly limited as long as the reaction proceeds, and may be, for example, in the range of 50 to 150° C. The reaction time is also not particularly limited as long as the desired structure of component (A-1) is achieved, and may be, for example, in the range of 1 to 10 hours.

[0080] In such a reaction, the degree of polymerization can be adjusted by adjusting the ratio of the amounts of the compound (x1) and the epihalohydrin (x2), and the epoxy group equivalent and molecular weight of the resulting component (A-1) can be controlled. To efficiently achieve a suitable structure of formula (2), the amount of epihalohydrin (x2) must be sufficiently greater than the amount of compound (x1). Typically, the amount of epihalohydrin (x2) is 3 moles or more, preferably 5 moles or more, 7 moles or more, 9 moles or more, or 10 moles or more per mole of hydroxy groups in compound (x1).

[0081] After the reaction, excess epihalohydrin (x2) is distilled off. Furthermore, after the reaction, a purification step such as washing with water or microfiltration may be carried out to remove by-product salts and excess starting materials from the system. Specifically, the residue obtained by distilling off excess epihalohydrin (x2) may be dissolved in an organic solvent, filtered, washed with water to remove by-product salts, and then purified by distilling off the organic solvent.

[0082] --Reaction of compound (x1) with organic peracid (x2)-- When compound (x1) has an olefinic double bond (when n1b in formula (x1) is 1 or greater), compound (x1) is reacted with organic peracid (x2). The reaction of compound (x1) with organic peracid (x2) may be carried out by a conventionally known oxidation reaction (oxirane formation reaction) using an olefin compound and an organic peracid. The reaction may proceed in a solvent-free system without using a solvent, or in an organic solvent system using an organic solvent. The types of organic solvents that can be used are as described above in connection with the reaction of compound (x1) with epihalohydrin (x2).

[0083] The reaction temperature is not particularly limited as long as the reaction proceeds, and may be, for example, in the range of 50 to 150° C. The reaction time is also not particularly limited as long as the desired structure of component (A-1) is achieved, and may be, for example, in the range of 1 to 10 hours.

[0084] After the reaction, purification steps such as washing with water, microfiltration, etc. The reaction of compound (x1) with organic peracid (x2) may be carried out according to the method described in Japanese Patent No. 2539648, for example.

[0085] When compound (x1) has both a hydroxy group or a carboxy group and an olefinic double bond (when n1a or n1b in formula (x1) is 1 or more), the hydroxy group or the carboxy group of compound (x1) may be reacted with epihalohydrin (x2), and then the olefinic double bond of compound (x1) may be reacted with organic peracid (x2).

[0086] The resin composition of the present invention may contain (A-2) other epoxy resins as long as it contains the above-mentioned component (A-1) as an epoxy resin.

[0087] There are no particular restrictions on the type of component (A-2), so long as it has one or more (preferably two or more) epoxy groups in one molecule. Examples of the component (A-2) include bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, bisphenol AF type epoxy resins, phenol novolac type epoxy resins, tert-butyl-catechol type epoxy resins, naphthol type epoxy resins, naphthalene type epoxy resins, naphthylene ether type epoxy resins, glycidylamine type epoxy resins, glycidyl ester type epoxy resins, cresol novolac type epoxy resins, biphenyl type epoxy resins, phenol aralkyl type epoxy resins, biphenyl aralkyl type epoxy resins, fluorene skeleton type epoxy resins, dicyclopentadiene type epoxy resins, pentaerythritol type epoxy resins, anthracene type epoxy resins, linear aliphatic epoxy resins, epoxy resins having a butadiene structure, alicyclic epoxy resins, heterocyclic epoxy resins, spiro ring-containing epoxy resins, cyclohexanedimethanol type epoxy resins, trimethylol type epoxy resins, and halogenated epoxy resins.

[0088] The component (A-2) can be classified into epoxy resins that are liquid at a temperature of 20°C (hereinafter referred to as "liquid epoxy resins") and epoxy resins that are solid at a temperature of 20°C (hereinafter referred to as "solid epoxy resins"). When the resin composition of the present invention contains the component (A-2), it may further contain only a liquid epoxy resin, or only a solid epoxy resin, or it may further contain a combination of a liquid epoxy resin and a solid epoxy resin.

[0089] The epoxy group equivalent of the component (A-2) is preferably 50 g / eq. to 2000 g / eq., more preferably 60 g / eq. to 1000 g / eq., and even more preferably 80 g / eq. to 500 g / eq.

[0090] The weight average molecular weight (Mw) of the component (A-2) is preferably 100 to 5,000, more preferably 250 to 3,000, and even more preferably 400 to 1500. The Mw of the epoxy resin can be measured by the GPC method as a polystyrene-equivalent value.

[0091] Even when a high content of active ester resin or inorganic filler is used, a resin composition exhibiting low viscosity can be realized. Furthermore, a cured product exhibiting good adhesion to a conductor layer when exposed to a high-temperature, high-humidity environment can be realized. Therefore, the content of component (A-1) in the resin composition is preferably 1% by mass or more, more preferably 2% by mass or more, 4% by mass or more, or 5% by mass or more, and even more preferably 6% by mass or more, 8% by mass or more, 10% by mass or more, 11% by mass or more, or 12% by mass or more, based on 100% by mass of the resin components in the resin composition. The upper limit of the content is not particularly limited and may be determined depending on the properties required of the resin composition. However, from the viewpoint of further enjoying the effects of the present invention when combined with the (B) active ester resin described below, the upper limit is preferably 60% by mass or less, more preferably 50% by mass or less, and even more preferably 45% by mass or less, or 40% by mass or less. Therefore, in one embodiment, the content of component (A-1) in the resin composition is 1% by mass or more and 45% by mass or less, based on 100% by mass of the resin components in the resin composition.

[0092] In the present invention, the term "resin component" in relation to the resin composition refers to the non-volatile components constituting the resin composition excluding the inorganic filler (D) described below.

[0093] When the resin composition of the present invention contains component (A-2), i.e., another epoxy resin, the content of component (A-1) is preferably 10% by mass or more, more preferably 20% by mass or more, and even more preferably 25% by mass or more or 30% by mass or more, when the total of component (A) (total of non-volatile components) is taken as 100% by mass. There is no particular upper limit to the content of component (A-1) in the total of component (A), and it may be 100% by mass, but it may also be, for example, 95% by mass or less, 90% by mass or less, 85% by mass or less, 80% by mass or less, etc.

[0094] In the resin composition of the present invention, the total content of the (A) component may be appropriately determined so as to satisfy the preferred ranges for the content of the (A-1) component and the content of the (A-1) component relative to the total (A) component. For example, the total content of the (A) component in the resin composition is preferably 10% by mass or more, more preferably 15% by mass or more, and even more preferably 20% by mass or more, 25% by mass or more, 26% by mass or more, 28% by mass or more, or 30% by mass or more, based on 100% by mass of the resin components in the resin composition. The upper limit of the content is not particularly limited and may be determined depending on the properties required of the resin composition. However, from the viewpoint of being able to further enjoy the effects of the present invention in combination with the (B) active ester resin described below, it may be preferably 70% by mass or less, 65% by mass or less, 60% by mass or less, 55% by mass or less, or 50% by mass or less.

[0095] <(B) Active ester resin> The resin composition of the present invention contains an active ester resin as component (B).

[0096] As the active ester resin, a compound having one or more active ester groups per molecule can be used. Among them, preferred active ester resins are compounds having two or more highly reactive ester groups per molecule, such as phenol esters, thiophenol esters, N-hydroxyamine esters, and esters of heterocyclic hydroxy compounds. The active ester resin is preferably one obtained by a condensation reaction between a carboxylic acid compound and / or a thiocarboxylic acid compound and a hydroxy compound and / or a thiol compound. In particular, 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.

[0097] Examples of the carboxylic acid compound include benzoic acid, acetic acid, succinic acid, maleic acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, and pyromellitic acid.

[0098] Examples of phenol compounds or naphthol compounds include hydroquinone, resorcinol, bisphenol A, bisphenol F, bisphenol S, phenolphthalene, methylated bisphenol A, methylated bisphenol F, methylated bisphenol S, phenol, o-cresol, m-cresol, p-cresol, catechol, α-naphthol, β-naphthol, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, phloroglucin, benzenetriol, dicyclopentadiene-type diphenol compounds, and phenol novolak. Here, "dicyclopentadiene-type diphenol compounds" refers to diphenol compounds obtained by condensing one dicyclopentadiene molecule with two phenol molecules.

[0099] Specific examples of preferred active ester resins from the viewpoint of further enjoying the effects of the present invention include active ester resins containing a dicyclopentadiene-type diphenol structure, active ester resins containing a naphthalene structure, active ester resins containing an acetylated product of phenol novolac, and active ester resins containing a benzoylated product of phenol novolac. Among these, active ester resins containing a naphthalene structure and active ester resins containing a dicyclopentadiene-type diphenol structure are more preferred from the viewpoint of being able to realize a resin composition exhibiting low viscosity in combination with the above-mentioned component (A-1) and to realize a cured product exhibiting good adhesion to a conductor layer when exposed to a high-temperature, high-humidity environment. The "dicyclopentadiene-type diphenol structure" refers to a divalent structural unit consisting of phenylene-dicyclopentylene-phenylene.

[0100] Commercially available products of component (B) include activated ester resins containing a dicyclopentadiene-type diphenol structure, such as "EXB-9451," "EXB-9460," "EXB-9460S," "HPC-8000-65T," "HPC-8000H-65TM," and "HPC-8000L-65TM" (manufactured by DIC Corporation); and activated ester resins containing a naphthalene structure, such as "EXB-8100L-65T," "EXB-8150-60T," "EXB-8150-62T," "EXB-9416-70BK," "HPC-8150H-60T," and "HPC-8150L-65T." -62T" and "HP-B-8151-62T" (manufactured by DIC Corporation); a phosphorus-containing activated ester resin "EXB9401" (manufactured by DIC Corporation); an activated ester resin which is an acetylated product of phenol novolac "DC808" (manufactured by Mitsubishi Chemical Corporation); activated ester resins which are benzoylated products of phenol novolac "YLH1026", "YLH1030", and "YLH1048" (manufactured by Mitsubishi Chemical Corporation); an activated ester resin containing a styryl group and a naphthalene structure "PC1300-02-65MA" (manufactured by Air Water Inc.), and the like.

[0101] The component (B) may be used alone or in combination of two or more types in any ratio.

[0102] The active ester group equivalent of component (B) (sometimes abbreviated as "active group equivalent" in this specification) is preferably 50 g / eq. to 500 g / eq., more preferably 50 g / eq. to 400 g / eq., and even more preferably 100 g / eq. to 300 g / eq. The active ester group equivalent is the mass of the active ester resin per equivalent of the active ester group.

[0103] From the viewpoint of easily realizing a resin composition that provides good dielectric properties, the content of component (B) in the resin composition is preferably 10% by mass or more, more preferably 20% by mass or more, and even more preferably 30% by mass or more, 35% by mass or more, or 40% by mass or more, based on 100% by mass of the resin components in the resin composition. The upper limit of the content is not particularly limited and may be determined depending on the properties required of the resin composition, but may be, for example, 70% by mass or less, 65% by mass or less, or 60% by mass or less.

[0104] In the resin composition of the present invention, the mass ratio of component (B) to component (A-1) (component (B) / component (A-1)) is preferably 1 or more, more preferably 1.2 or more, even more preferably 1.3 or more, 1.5 or more, 1.6 or more, 1.8 or more, or 2 or more, from the viewpoint of providing a cured product with excellent dielectric properties. As described above, the resin composition of the present invention using component (A-1) can provide a resin composition exhibiting low viscosity even when component (B) is contained to an extent sufficient to provide excellent dielectric properties, and can provide a cured product exhibiting good adhesion to a conductor layer when exposed to a high-temperature, high-humidity environment. For example, in the resin composition of the present invention, the mass ratio of component (B) to component (A-1) may be increased to 2.5 or more, 3 or more, or 3.5 or more. The upper limit of the mass ratio (component (B) / component (A-1)) may be, for example, 10 or less, 8 or less, 6 or less, or 5 or less.

[0105] In the resin composition of the present invention, the mass ratio of component (B) to component (A) (component (B) / component (A)) is preferably 0.8 or more, more preferably 1 or more, from the viewpoint of providing a cured product with excellent dielectric properties. As described above, the resin composition of the present invention using component (A-1) can provide a resin composition exhibiting low viscosity even when component (B) is contained to an extent sufficient to provide excellent dielectric properties, and can provide a cured product exhibiting good adhesion to a conductor layer when exposed to a high-temperature, high-humidity environment. For example, in the resin composition of the present invention, the mass ratio of component (B) to component (A) may be increased to 1.1 or more, 1.2 or more, or 1.3 or more. The upper limit of the mass ratio (component (B) / component (A)) may be, for example, 2 or less, 1.9 or less, or 1.8 or less.

[0106] <(C) Other hardeners> The resin composition of the present invention may further contain, as component (C), a curing agent other than component (B) (also referred to as "other curing agent").

[0107] Examples of the component (C) include phenol-based curing agents, naphthol-based curing agents, acid anhydride-based curing agents, cyanate ester-based curing agents, carbodiimide-based curing agents, amine-based curing agents, etc. The component (C) may be used alone or in combination of two or more.

[0108] As the phenol-based curing agent and naphthol-based curing agent, those having a novolac structure are preferred from the viewpoint of heat resistance and water resistance. Furthermore, from the viewpoint of adhesion to the conductor layer, nitrogen-containing phenol-based curing agents and nitrogen-containing naphthol-based curing agents are preferred, and triazine skeleton-containing phenol-based curing agents and triazine skeleton-containing naphthol-based curing agents are more preferred.

[0109] Specific examples of phenol-based curing agents and naphthol-based curing agents include "MEH-7700," "MEH-7810," "MEH-7851," and "MEH-8000H" manufactured by Meiwa Chemical Industry Co., Ltd.; "NHN," "CBN," and "GPH" manufactured by Nippon Kayaku Co., Ltd.; and "SN-170," "SN-180," "SN-190," "SN-475," "SN-485," "SN-495," "SN-495V," and "SN-37" manufactured by Nippon Steel Chemical & Material Co., Ltd. 5" and "SN-395" manufactured by DIC Corporation; "TD-2090", "TD-2090-60M", "LA-7052", "LA-7054", "LA-1356", "LA-3018", "LA-3018-50P", "EXB-9500", "HPC-9500", "KA-1160", "KA-1163", and "KA-1165" manufactured by Gun-ei Chemical Co., Ltd.; and "GDP-6115L", "GDP-6115H", and "ELPC75" manufactured by Gun-ei Chemical Co., Ltd.

[0110] Examples of acid anhydride curing agents include curing agents having one or more acid anhydride groups in one molecule. Specific examples of acid anhydride curing agents 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, and benzophenonetetracarboxylic dianhydride. Examples of acid anhydrides include biphenyltetracarboxylic dianhydride, naphthalenetetracarboxylic dianhydride, oxydiphthalic dianhydride, 3,3'-4,4'-diphenylsulfonetetracarboxylic 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), and polymeric acid anhydrides such as styrene-maleic acid resins (copolymers of styrene and maleic acid). Commercially available acid anhydride curing agents include "MH-700" manufactured by New Japan Chemical Co., Ltd.

[0111] Examples of cyanate ester curing agents include bifunctional cyanate resins such as bisphenol A dicyanate, polyphenol cyanate, oligo(3-methylene-1,5-phenylene cyanate), 4,4'-methylenebis(2,6-dimethylphenyl cyanate), 4,4'-ethylidene diphenyl dicyanate, hexafluorobisphenol A dicyanate, 2,2-bis(4-cyanate)phenylpropane, 1,1-bis(4-cyanatephenylmethane), bis(4-cyanate-3,5-dimethylphenyl)methane, 1,3-bis(4-cyanatephenyl-1-(methylethylidene))benzene, bis(4-cyanatephenyl)thioether, and bis(4-cyanatephenyl)ether; polyfunctional cyanate resins derived from phenol novolac, cresol novolac, etc.; and prepolymers in which these cyanate resins are partially converted to triazine. Specific examples of cyanate ester curing agents include "PT30" and "PT60" (phenol novolac type multifunctional cyanate ester resins), "ULL-950S" (multifunctional cyanate ester resin), "BA230" and "BA230S75" (prepolymers in which part or all of bisphenol A dicyanate has been triazine converted to a trimer), all of which are manufactured by Lonza Japan.

[0112] Specific examples of carbodiimide-based curing agents include Carbodilite (registered trademark) V-03 (carbodiimide group equivalent: 216 g / eq.), V-05 (carbodiimide group equivalent: 262 g / eq.), V-07 (carbodiimide group equivalent: 200 g / eq.), and V-09 (carbodiimide group equivalent: 200 g / eq.), all manufactured by Nisshinbo Chemical Inc.; and Stavaxol (registered trademark) P (carbodiimide group equivalent: 302 g / eq.), all manufactured by Rhein Chemie.

[0113] Examples of the amine-based curing agent include curing agents having one or more amino groups in one molecule, such as aliphatic amines, polyether amines, alicyclic amines, and aromatic amines. Specific examples of the amine-based curing agent include 4,4'-methylenebis(2,6-dimethylaniline), diphenyldiaminosulfone, 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, and 2,2-bis(3-amino-4-hydroxybenzoyl)methylpropional. Examples of suitable amine curing agents include 4,4'-bis(4-aminophenoxy)biphenyl, bis(4-(4-aminophenoxy)phenyl)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, and bis(4-(3-aminophenoxy)phenyl)sulfone. Commercially available amine curing agents may be used, such as "KAYABOND C-200S," "KAYABOND C-100," "KAYAHARD AA," "KAYAHARD AB," and "KAYAHARD AS" manufactured by Nippon Kayaku Co., Ltd., and "Epicure W" manufactured by Mitsubishi Chemical Corporation.

[0114] When the resin composition of the present invention contains component (C), the content of component (C) in the resin composition may be determined depending on the properties required of the resin composition, but when the resin components in the resin composition are taken as 100% by mass, it is, for example, 0.1% by mass or more, preferably 1% by mass or more, more preferably 2% by mass or more, and even more preferably 3% by mass or more. The upper limit of the content of component (C) is not particularly limited, but can be, for example, 20% by mass or less, 15% by mass or less, 10% by mass or less, etc.

[0115] As described above, the resin composition of the present invention contains an active ester resin, i.e., component (B). In the resin composition of the present invention, when the total of the non-volatile components of components (B) and (C) is taken as 100% by mass, the content of component (B) is preferably 50% by mass or more, more preferably 60% by mass or more, and even more preferably 70% by mass or more, 75% by mass or more, or 80% by mass or more. The upper limit of the content of component (B) relative to the total of components (B) and (C) is not particularly limited and may be 100% by mass, but may also be, for example, 95% by mass or less, 90% by mass or less, etc.

[0116] <(D) Inorganic filler> The resin composition of the present invention may further contain an inorganic filler as component (D). By including component (D), the linear thermal expansion coefficient and dielectric loss tangent can be further reduced.

[0117] Examples of materials for component (D) include silica, alumina, glass, cordierite, silicon oxide, barium sulfate, barium carbonate, talc, clay, mica powder, zinc oxide, hydrotalcite, boehmite, aluminum silicate, 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 titanate zirconate, barium zirconate, calcium zirconate, zirconium phosphate, and zirconium tungstate phosphate. Among these, silica is particularly preferred. Examples of silica include amorphous silica, fused silica, crystalline silica, synthetic silica, and hollow silica. Spherical silica is preferred. Component (D) may be used alone or in combination of two or more.

[0118] Commercially available products of component (D) include, for example, "UFP-30" manufactured by Denka Chemical Industry Co., Ltd.; "SP60-05" and "SP507-05" manufactured by Nippon Steel Chemical & Material Co., Ltd.; "YC100C," "YA050C," "YA050C-MJE," and "YA010C" manufactured by Admatechs Co., Ltd.; "UFP-30" manufactured by Denka Company Limited; "Silfil NSS-3N," "Silfil NSS-4N," and "Silfil NSS-5N" manufactured by Tokuyama Corporation; "SC2500SQ," "SO-C4," "SO-C2," and "SO-C1" manufactured by Admatechs Co., Ltd.; "DAW-03" and "FB-105FD" manufactured by Denka Company Limited; "Cellphears" and "MGH-005" manufactured by Taiheiyo Cement Corporation; and "Sferique" and "BA-1" manufactured by JGC Catalysts and Chemicals Co., Ltd.

[0119] The average particle size of component (D) is not particularly limited, but is preferably 10 μm or less, more preferably 5 μm or less, even more preferably 3 μm or less, 2 μm or less, 1 μm or less, or 0.7 μm or less. The lower limit of the average particle size is not particularly limited, but is preferably 0.01 μm or more, more preferably 0.05 μm or more, even more preferably 0.07 μm or more, 0.1 μm or more, or 0.2 μm or more. The average particle size of component (D) can be measured by a laser diffraction / scattering method based on Mie scattering theory. Specifically, the particle size distribution of the inorganic filler is prepared on a volume basis using a laser diffraction / scattering particle size distribution analyzer, and the median diameter is used as the average particle size. A measurement sample can be prepared by weighing 100 mg of inorganic filler and 10 g of methyl ethyl ketone into a vial and dispersing the mixture ultrasonically for 10 minutes. The measurement sample was measured using a laser diffraction particle size distribution analyzer, with blue and red light source wavelengths used, and the particle size distribution of the inorganic filler on a volume basis was measured using a flow cell system, and the average particle size was calculated as the median diameter from the particle size distribution obtained. An example of a laser diffraction particle size distribution analyzer is the "LA-960" manufactured by Horiba, Ltd.

[0120] The specific surface area of ​​component (D) is not particularly limited, but is preferably 0.1 m 2 / g or more, more preferably 0.5m2 / g or more, more preferably 1m 2 / g or more, 3m 2 / g or more or 5m 2 The upper limit of the specific surface area is not particularly limited, but is preferably 100 m 2 / g or less, more preferably 80m 2 / g or less, more preferably 60m 2 / g or less, 50m 2 / g or less or 40m 2 The specific surface area of ​​component (D) is determined in accordance with the BET method by adsorbing nitrogen gas onto the surface of a sample using a specific surface area measuring device (Macsorb HM-1210 manufactured by Mountech Co., Ltd.) and calculating the specific surface area using the BET multipoint method.

[0121] Component (D) is preferably surface-treated with an appropriate surface treatment agent. This surface treatment can enhance the moisture resistance and dispersibility of component (D). Examples of surface treatment agents include silane coupling agents such as vinyl silane coupling agents, epoxy silane coupling agents, styryl silane coupling agents, (meth)acrylic silane coupling agents, amino silane coupling agents, isocyanurate silane coupling agents, ureido silane coupling agents, mercapto silane coupling agents, isocyanate silane coupling agents, and acid anhydride silane coupling agents; non-silane coupling alkoxysilane compounds such as methyltrimethoxysilane and phenyltrimethoxysilane; and silazane compounds. The surface treatment agents may be used alone or in combination of two or more.

[0122] Examples of commercially available surface treatment agents include "KBM403" (3-glycidoxypropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., "KBM803" (3-mercaptopropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., "KBE903" (3-aminopropyltriethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., "KBM573" (N-phenyl-3-aminopropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., and "SZ-31" (hexamethyldisilazane) manufactured by Shin-Etsu Chemical Co., Ltd.

[0123] The degree of surface treatment with the surface treatment agent is preferably within a predetermined range from the viewpoint of improving the dispersibility of the inorganic filler. Specifically, 100% by mass of the inorganic filler is preferably surface-treated with 0.2 to 5% by mass of the surface treatment agent.

[0124] 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 set to 0.02 mg / m 2 More than 0.1 mg / m is preferable. 2 More preferably, 0.2 mg / m or more 2 On the other hand, from the viewpoint of preventing an increase in the melt viscosity of the resin composition or the melt viscosity in the form of a sheet, it is more preferable that the melt viscosity is 1.0 mg / m 2 Less than 0.8 mg / m is preferred 2 Less than 0.5 mg / m is more preferable. 2 The following is even more preferred. The carbon amount per unit surface area of ​​component (D) can be measured after the surface-treated inorganic filler is washed with a solvent (e.g., methyl ethyl ketone (MEK)). Specifically, a sufficient amount of MEK as a solvent is added to the inorganic filler that has been surface-treated with a surface treatment agent, and ultrasonic cleaning is performed at 25°C for 5 minutes. The supernatant is removed, the solid content is dried, and then the carbon amount per unit surface area of ​​the inorganic filler can be measured using a carbon analyzer. An "EMIA-320V" manufactured by Horiba, Ltd., or the like can be used as the carbon analyzer.

[0125] When the resin composition of the present invention contains component (D), the content of component (D) in the resin composition is, for example, 40% by mass or more, preferably 50% by mass or more, based on 100% by mass of the nonvolatile components in the resin composition, from the viewpoint of easily realizing a resin composition that provides even better dielectric properties and a low coefficient of thermal expansion. As described above, according to the present invention using component (A-1), even when the content of component (D) is high, it is possible to obtain a cured product that exhibits good adhesion to a conductor layer when exposed to a high-temperature, high-humidity environment. For example, in the resin composition of the present invention, the content of component (D) may be increased to 60% by mass or more, 65% by mass or more, or 70% by mass or more. The upper limit of the content of component (D) is not particularly limited, but may be, for example, 90% by mass or less, 85% by mass or less, etc.

[0126] <(E) Thermoplastic resin> The resin composition of the present invention may contain a thermoplastic resin as the component (E).

[0127] Examples of thermoplastic resins include phenoxy resins, polyvinyl acetal resins, polyolefin resins, polybutadiene resins, polyimide resins, polyamideimide resins, polyetherimide resins, polysulfone resins, polyethersulfone resins, polyphenylene ether resins, polycarbonate resins, polyetheretherketone resins, and polyester resins. The thermoplastic resins may be used alone or in combination of two or more.

[0128] The polystyrene-equivalent weight-average molecular weight of the thermoplastic resin is preferably in the range of 8,000 to 70,000, more preferably in the range of 10,000 to 60,000, and even more preferably in the range of 20,000 to 60,000. The polystyrene-equivalent weight-average molecular weight of the thermoplastic resin is measured by gel permeation chromatography (GPC). Specifically, the polystyrene-equivalent weight-average molecular weight of the thermoplastic resin is measured using a Shimadzu LC-9A / RID-6A measuring device, a Showa Denko Shodex K-800P / K-804L / K-804L column, and chloroform or the like as the mobile phase at a column temperature of 40°C, and can be calculated using a calibration curve of standard polystyrene.

[0129] Examples of phenoxy resins include phenoxy resins having one or more skeletons selected from the group consisting of bisphenol A, bisphenol F, bisphenol S, bisphenolacetophenone, novolac, biphenyl, fluorene, dicyclopentadiene, norbornene, naphthalene, anthracene, adamantane, terpene, and trimethylcyclohexane. The terminal of the phenoxy resin may be any functional group such as a phenolic hydroxyl group or an epoxy group. One type of phenoxy resin may be used alone, or two or more types may be used in combination. Specific examples of phenoxy resins include "1256" and "4250" (both phenoxy resins containing a bisphenol A skeleton), "YX8100" (phenoxy resin containing a bisphenol S skeleton), and "YX6954" (phenoxy resin containing a bisphenol acetophenone skeleton), all manufactured by Mitsubishi Chemical Corporation. Other examples include "FX280" and "FX293" manufactured by Nippon Steel Chemical & Material Co., Ltd., and "YX7553," "YL6794," "YL7213," "YL7290," and "YL7482" manufactured by Mitsubishi Chemical Corporation.

[0130] Examples of polyvinyl acetal resins include polyvinyl formal resins and polyvinyl butyral resins, with polyvinyl butyral resins being preferred. Specific examples of polyvinyl acetal resins include Denka Butyral 4000-2, Denka Butyral 5000-A, Denka Butyral 6000-C, and Denka Butyral 6000-EP, manufactured by Denka Co., Ltd., and S-LEC BH series, BX series, KS series, BL series, and BM series, manufactured by Sekisui Chemical Co., Ltd.

[0131] Specific examples of polyimide resins include "Rikacoat SN20" and "Rikacoat PN20" manufactured by New Japan Chemical Co., Ltd. Specific examples of polyimide resins also include modified polyimides such as linear polyimides obtained by reacting bifunctional hydroxyl group-terminated polybutadiene, a diisocyanate compound, and a tetrabasic acid anhydride (disclosed in JP-A No. 2006-37083), and polysiloxane skeleton-containing polyimides (disclosed in JP-A Nos. 2002-12667 and 2000-319386, etc.).

[0132] Specific examples of polyamide-imide resins include "Vylomax HR11NN" and "Vylomax HR16NN" manufactured by Toyobo Co., Ltd. Specific examples of polyamide-imide resins also include modified polyamide-imides such as polysiloxane skeleton-containing polyamide-imides "KS9100" and "KS9300" manufactured by Hitachi Chemical Co., Ltd.

[0133] A specific example of the polyethersulfone resin is "PES5003P" manufactured by Sumitomo Chemical Co., Ltd.

[0134] Specific examples of polysulfone resins include polysulfones "P1700" and "P3500" manufactured by Solvay Advanced Polymers.

[0135] When the resin composition of the present invention contains component (E), the content of component (E) in the resin composition may be determined depending on the properties required of the resin composition, but when the resin components in the resin composition are taken as 100% by mass, it is, for example, 0.1% by mass or more, preferably 0.3% by mass or more, more preferably 0.5% by mass or more, 0.6% by mass or more, 0.8% by mass or more, or 1% by mass or more. The upper limit of the content of component (E) is not particularly limited, but may be, for example, 20% by mass or less, 18% by mass or less, 16% by mass or less, or 15% by mass or less.

[0136] <(F) Radical Polymerizable Resin> The resin composition of the present invention may contain a radical polymerizable resin as the component (F).

[0137] The type of radical polymerizable resin is not particularly limited as long as it has one or more (preferably two or more) radical polymerizable unsaturated groups in one molecule. Examples of the radical polymerizable resin include resins having one or more radical polymerizable unsaturated groups selected from maleimide, vinyl, allyl, styryl, vinylphenyl, acryloyl, methacryloyl, fumaroyl, and maleoyl groups. Among these, from the viewpoint of producing a cured product exhibiting even better dielectric properties, the radical polymerizable resin is preferably one or more selected from maleimide resins, (meth)acrylic resins, and styryl resins.

[0138] The type of maleimide resin is not particularly limited as long as it has one or more (preferably two or more) maleimide groups (2,5-dihydro-2,5-dioxo-1H-pyrrol-1-yl groups) in one molecule. Examples of maleimide resins include: (1) maleimide resins containing an aliphatic skeleton (preferably an aliphatic skeleton having 36 carbon atoms derived from dimer diamine), such as "BMI-3000J," "BMI-5000," "BMI-1400," "BMI-1500," "BMI-1700," and "BMI-689" (all manufactured by Designer Molecules), and "SLK6895-T90" (manufactured by Shin-Etsu Chemical Co., Ltd.); (2) maleimide resins containing an indane skeleton, as described in the Japan Institute of Invention and Innovation's Technical Disclosure Bulletin No. 2020-500211; and (3) maleimide resins containing an aromatic ring skeleton directly bonded to the nitrogen atom of the maleimide group, such as "MIR-3000-70MT" (manufactured by Nippon Kayaku Co., Ltd.), "BMI-4000" (manufactured by Daiwa Kasei Co., Ltd.), and "BMI-80" (manufactured by Keiai Kasei Co., Ltd.).

[0139] The (meth)acrylic resin may be a monomer or an oligomer, and may be any type of (meth)acrylic resin, as long as it has one or more (preferably two or more) (meth)acryloyl groups in one molecule. Here, the term "(meth)acryloyl group" is a general term for acryloyl groups and methacryloyl groups. Examples of methacrylic resins include (meth)acrylate monomers, as well as (meth)acrylic resins such as "A-DOG" (manufactured by Shin-Nakamura Chemical Co., Ltd.), "DCP-A" (manufactured by Kyoeisha Chemical Co., Ltd.), "NPDGA," "FM-400," "R-687," "THE-330," "PET-30," and "DPHA" (all manufactured by Nippon Kayaku Co., Ltd.).

[0140] The styryl resin is not particularly limited in type, and may be a monomer or oligomer, as long as it has one or more (preferably two or more) styryl groups or vinylphenyl groups in one molecule. Examples of the styryl resin include styrene monomers and styryl resins such as "OPE-2St," "OPE-2St 1200," and "OPE-2St 2200" (all manufactured by Mitsubishi Gas Chemical Company, Inc.).

[0141] When the resin composition of the present invention contains component (F), the content of component (F) in the resin composition may be determined depending on the properties required of the resin composition, but is, for example, 0.1% by mass or more, preferably 0.3% by mass or more, more preferably 0.5% by mass or more or 0.6% by mass or more, where the resin components in the resin composition are taken as 100% by mass. The upper limit of the content of component (F) is not particularly limited, but may be, for example, 15% by mass or less, 10% by mass or less, or 6% by mass or less.

[0142] <(G) Curing accelerator> The resin composition of the present invention may contain a curing accelerator as the component (G).

[0143] Examples of the component (G) include phosphorus-based curing accelerators, amine-based curing accelerators, imidazole-based curing accelerators, guanidine-based curing accelerators, metal-based curing accelerators, peroxide-based curing accelerators, etc. The curing accelerators may be used alone or in combination of two or more.

[0144] When the resin composition of the present invention contains the (G) component, the content of the (G) component in the resin composition is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, and even more preferably 0.1% by mass or more, and is preferably 2% by mass or less, more preferably 1.5% by mass or less, or 1% by mass or less, when the resin components in the resin composition are taken as 100% by mass.

[0145] <Optional additives> The resin composition of the present invention may further contain any additives. Examples of such additives include radical polymerization initiators such as peroxide radical polymerization initiators and azo radical polymerization initiators; organometallic compounds such as organocopper compounds, organozinc compounds, and organocobalt 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 leveling agents and acrylic polymer leveling agents; thickeners such as bentone and montmorillonite; antifoaming agents such as silicone antifoaming agents, acrylic antifoaming agents, fluorine-based antifoaming agents, and vinyl resin antifoaming agents; ultraviolet absorbers such as benzotriazole ultraviolet absorbers; adhesion improvers such as urea silanes; triazole adhesion promoters, tetrazolates, and the like. Examples of suitable additives include adhesion promoters such as phenol-based adhesion promoters and triazine-based adhesion promoters; 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, and red phosphorus), nitrogen-based flame retardants (e.g., melamine sulfate), halogen-based flame retardants, and inorganic flame retardants (e.g., antimony trioxide); dispersants such as phosphate ester-based dispersants, polyoxyalkylene-based dispersants, acetylene-based dispersants, silicone-based dispersants, anionic dispersants, and cationic dispersants; and 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 content of such additives may be determined depending on the properties required of the resin composition.

[0146] <Organic solvents> The resin composition of the present invention may further contain an organic solvent as a volatile component. 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, and diphenyl ether; alcohol solvents such as methanol, ethanol, propanol, butanol, and ethylene glycol; 2-ethoxyethyl acetate, propylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl diglycol acetate, γ-butyrolactone, and methyl methoxypropionate. Examples of suitable organic solvents include ether ester solvents such as ethanol; 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; and aromatic hydrocarbon solvents such as benzene, toluene, xylene, ethylbenzene, and trimethylbenzene. These organic solvents may be used singly or in combination of two or more.

[0147] The resin composition of the present invention can be produced, for example, by adding component (A-1), component (B), and, if necessary, component (A-2), component (C), component (D), component (E), component (F), and component (G), as well as other additives and organic solvents, to any preparation vessel in any order and / or all at once and mixing them. The temperature can be appropriately set during the process of adding and mixing each component, and heating and / or cooling may be performed temporarily or throughout the process. During or after the process of adding and mixing the resin composition, the resin composition may be stirred or shaken using a stirring or shaking device such as a mixer to uniformly disperse the components. Simultaneous stirring or shaking may also involve degassing under low-pressure conditions, such as under vacuum.

[0148] As described above, the resin composition of the present invention containing the component (A-1) exhibits low viscosity and can provide a cured product that exhibits good adhesion to a conductor layer when exposed to a high-temperature, high-humidity environment.

[0149] In one embodiment, the resin composition of the present invention exhibits a low viscosity. For example, when the dynamic viscoelasticity is measured as described in the section <Measurement of Minimum Melt Viscosity> below, the minimum melt viscosity of the resin composition of the present invention may be preferably 3000 poise or less, 2500 poise or less, 2000 poise or less, 1800 poise or less, 1600 poise or less, or 1500 poise or less.

[0150] In one embodiment, a cured product of the resin composition of the present invention exhibits a characteristic of high adhesion to a conductor layer when exposed to a high-temperature, high-humidity environment. For example, when exposed to high-temperature, high-humidity conditions of 130°C and 85% RH for 100 hours as described in the section <Measurement of Copper Foil Peel Strength After High-Temperature, High-Humidity Environmental Test (HAST)> below, the adhesion strength to the conductor foil after exposure to the high-temperature, high-humidity conditions is preferably 0.4 kgf / cm or more, 0.42 kgf / cm or more, 0.44 kgf / cm or more, or 0.45 kgf / cm or more.

[0151] In one embodiment, the cured product of the resin composition of the present invention is characterized by high adhesion to a plated conductor layer. For example, when a plated conductor layer is formed as described in the section <Measurement of Peel Strength of Plated Conductor Layer> below, the adhesion strength to the plated conductor layer is preferably 0.4 kgf / cm or more, 0.42 kgf / cm or more, 0.44 kgf / cm or more, or 0.45 kgf / cm or more.

[0152] In one embodiment, a cured product of the resin composition of the present invention is characterized by high heat resistance. For example, when measured using a dynamic viscoelasticity measuring device under the conditions of a load of 1 g and a heating rate of 5°C / min as described in the section <Measurement of Glass Transition Temperature (Tg)> below, the glass transition temperature (Tg) may be preferably 150°C or higher, 152°C or higher, 154°C or higher, 156°C or higher, 158°C or higher, or 160°C or higher.

[0153] As described above, the resin composition of the present invention exhibits low viscosity and can provide a cured product that exhibits good adhesion to a conductor layer when exposed to a high-temperature, high-humidity environment. Furthermore, it has been confirmed that the present invention exhibits better heat resistance, such as a high glass transition temperature (Tg). Therefore, the resin composition of the present invention can be suitably used as a resin composition for forming an insulating layer of a printed wiring board (a resin composition for an insulating layer of a printed wiring board), and more suitably used as a resin composition for forming an interlayer insulating layer of a printed wiring board (a resin composition for an insulating interlayer of a printed wiring board). The resin composition of the present invention can also be suitably used when the printed wiring board is a circuit board with built-in components. The resin composition of the present invention can also be suitably used as a resin composition for forming an insulating layer of a rewiring board for a semiconductor package (a resin composition for an insulating layer of a rewiring board). In the present invention, printed wiring boards and rewiring boards are collectively referred to as "circuit boards," and therefore the resin composition of the present invention can be suitably used for the insulating layer of a circuit board.

[0154] The resin composition of the present invention can be further used in a wide range of applications requiring a resin composition, such as sheet-like laminate materials such as resin sheets and prepregs, solder resists, underfill materials, die bonding materials, hole filling resins, sealing resins, and component embedding resins.

[0155] [Sheet-type laminated materials (resin sheets, prepregs)] The resin composition of the present invention can be used as it is, but may also be used in the form of a sheet-like laminate material containing the resin composition.

[0156] As the sheet-like laminate material, the following resin sheets and prepregs are preferred.

[0157] In one embodiment, the resin sheet includes a support and a layer of a resin composition (hereinafter simply referred to as a "resin composition layer") provided on the support, and is characterized in that the resin composition layer is formed from the resin composition of the present invention.

[0158] The thickness of the resin composition layer varies depending on the application, and may be appropriately determined depending on the application. For example, from the viewpoint of thinning printed wiring boards and semiconductor packages, the thickness of the resin composition layer is preferably 100 μm or less, 80 μm or less, 60 μm or less, 50 μm or less, 40 μm or less, or 30 μm or less. The lower limit of the thickness of the resin composition layer is not particularly limited, but may usually be 1 μm or more, 5 μm or more, etc.

[0159] Examples of the support include a thermoplastic resin film, a metal foil, and a release paper, and a thermoplastic resin film or a metal foil is preferred. Therefore, in a preferred embodiment, the support is a thermoplastic resin film or a metal foil.

[0160] When a thermoplastic resin film is used as the support, examples of the thermoplastic resin include polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), acrylics such as polycarbonate (PC) and polymethyl methacrylate (PMMA), cyclic polyolefins, triacetyl cellulose (TAC), polyether sulfide (PES), polyether ketone, polyimide, etc. Among these, polyethylene terephthalate and polyethylene naphthalate are preferred, with inexpensive polyethylene terephthalate being particularly preferred.

[0161] When a metal foil is used as the support, examples of the metal foil include copper foil and aluminum foil, with copper foil being preferred. The copper foil may be a foil made of a single metal, copper, or an alloy of copper and another metal (e.g., tin, chromium, silver, magnesium, nickel, zirconium, silicon, titanium, etc.).

[0162] The surface of the support to be bonded to the resin composition layer may be subjected to a matte treatment, a corona treatment, or an antistatic treatment. Alternatively, a support having a release layer on the surface to be bonded to the resin composition layer may be used as the support. Examples of the release agent used in the release layer of the support having a release layer include one or more release agents selected from the group consisting of alkyd resins, polyolefin resins, urethane resins, and silicone resins. Commercially available products may be used as the support having a release layer, such as "SK-1," "AL-5," and "AL-7" manufactured by Lintec Corporation, "Lumirror T60" manufactured by Toray Industries, Inc., "Purex" manufactured by Teijin Limited, and "Uni-Peel" manufactured by Unitika Limited, which are PET films having a release layer primarily composed of an alkyd resin-based release agent.

[0163] The thickness of the support is not particularly limited, but is preferably in the range of 5 μm to 75 μm, more preferably 10 μm to 60 μm. When a support with a release layer is used, it is preferable that the thickness of the entire support with a release layer is in the above range.

[0164] When a metal foil is used as the support, a metal foil with a support substrate may be used, which is a thin metal foil with a peelable support substrate attached thereto. In one embodiment, the metal foil with a support substrate includes a support substrate, a release layer provided on the support substrate, and a metal foil provided on the release layer. When a metal foil with a support substrate is used as the support, the resin composition layer is provided on the metal foil.

[0165] In the metal foil with a supporting substrate, the material of the supporting substrate is not particularly limited, but examples thereof include copper foil, aluminum foil, stainless steel foil, titanium foil, copper alloy foil, etc. When copper foil is used as the supporting substrate, it may be electrolytic copper foil or rolled copper foil. Furthermore, the release layer is not particularly limited as long as it allows the metal foil to be released from the supporting substrate, and examples thereof include an alloy layer of an element selected from the group consisting of Cr, Ni, Co, Fe, Mo, Ti, W, and P; an organic coating, etc.

[0166] In the metal foil with a supporting substrate, the material of the metal foil is preferably, for example, copper foil or copper alloy foil.

[0167] In the metal foil with a supporting substrate, the thickness of the supporting substrate is not particularly limited, but is preferably in the range of 10 μm to 150 μm, more preferably in the range of 10 μm to 100 μm. The thickness of the metal foil may be, for example, in the range of 0.1 μm to 10 μm.

[0168] In one embodiment, the resin sheet may further include an optional layer, if necessary. Examples of such optional layers include a protective film provided on the surface of the resin composition layer that is not bonded to the support (i.e., the surface opposite the support). The thickness of the protective film is not particularly limited, but is, for example, 1 μm to 40 μm. By laminating the protective film, adhesion of dust and the like to the surface of the resin composition layer and scratches can be suppressed.

[0169] The resin sheet can be produced, for example, by preparing a liquid resin composition as is or a resin varnish by dissolving the resin composition in an organic solvent, applying this to a support using a die coater or the like, and then drying to form a resin composition layer.

[0170] The organic solvent may be the same as the organic solvent described as a component of the resin composition. The organic solvent may be used alone or in combination of two or more.

[0171] Drying may be carried out by known methods such as heating or hot air blowing. Drying conditions are not particularly limited, but drying is carried out so that the content of organic solvent in the resin composition layer becomes 10% by mass or less, preferably 5% by mass or less. Although this varies depending on the boiling point of the organic solvent in the resin composition or resin varnish, for example, when a resin composition or resin varnish containing 30% by mass to 60% by mass of organic solvent is used, the resin composition layer can be formed by drying at 50°C to 150°C for 3 to 10 minutes.

[0172] The resin sheet can be stored in a rolled state. When the resin sheet has a protective film, it can be used by peeling off the protective film.

[0173] In one embodiment, the prepreg is formed by impregnating a sheet-like fiber substrate with the resin composition of the present invention.

[0174] The sheet-like fiber substrate used for the prepreg is not particularly limited, and commonly used prepreg substrates such as glass cloth, aramid nonwoven fabric, and liquid crystal polymer nonwoven fabric can be used. From the viewpoint of thinning printed wiring boards and semiconductor chip packages, the thickness of the sheet-like fiber substrate is preferably 50 μm or less, more preferably 40 μm or less, even more preferably 30 μm or less, and particularly preferably 20 μm or less. There is no particular lower limit to the thickness of the sheet-like fiber substrate. It is usually 10 μm or more.

[0175] The prepreg can be produced by a known method such as a hot melt method or a solvent method.

[0176] The thickness of the prepreg may be in the same range as that of the resin composition layer in the resin sheet described above.

[0177] The sheet-like laminate material of the present invention can be suitably used to form an insulating layer of a printed wiring board (for the insulating layer of a printed wiring board), and can be more suitably used to form an interlayer insulating layer of a printed wiring board (for the insulating interlayer of a printed wiring board). The sheet-like laminate material of the present invention can also be suitably used to form an insulating layer of a rewiring board of a semiconductor package (for the insulating layer of a rewiring board). That is, the sheet-like laminate material of the present invention can be suitably used as an insulating layer of a circuit board.

[0178] [Circuit board] The resin composition of the present invention can be used to form an insulating layer for a circuit board. The present invention also provides such a circuit board, i.e., a circuit board comprising an insulating layer made of a cured product of the resin composition of the present invention.

[0179] <Printed wiring board> In one embodiment, the circuit board of the present invention is a printed wiring board.

[0180] The printed wiring board can be produced, for example, by using the above-mentioned resin sheet by a method including the following steps (I) and (II). (I) A step of laminating a resin sheet on an inner layer substrate so that the resin composition layer of the resin sheet is bonded to the inner layer substrate. (II) A step of curing (e.g., thermally curing) the resin composition layer to form an insulating layer.

[0181] The "inner layer substrate" used in step (I) is a member that will become the substrate of a printed wiring board, and examples thereof include glass epoxy substrates, metal substrates, polyester substrates, polyimide substrates, BT resin substrates, and thermosetting polyphenylene ether substrates. The substrate may have a conductor layer on one or both sides, and this conductor layer may be patterned. An inner layer substrate having a conductor layer (circuit) formed on one or both sides of the substrate may be referred to as an "inner layer circuit board." Furthermore, the "inner layer substrate" of the present invention also includes intermediate products on which an insulating layer and / or a conductor layer is to be further formed during the production of a printed wiring board. When the printed wiring board is a circuit board with built-in components, an inner layer substrate with built-in components may be used.

[0182] The inner layer substrate and the resin sheet can be laminated, for example, by thermocompression bonding the resin sheet to the inner layer substrate from the support side. Examples of a member for thermocompression bonding the resin sheet to the inner layer substrate (hereinafter also referred to as a "thermocompression bonding member") include a heated metal plate (such as a SUS end plate) or a metal roll (SUS roll). The thermocompression bonding member may be pressed directly onto the resin sheet, or may be pressed via an elastic material such as heat-resistant rubber so that the resin sheet can sufficiently conform to the surface irregularities of the inner layer substrate.

[0183] 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 temperature is preferably in the range of 60°C to 160°C, more preferably 80°C to 140°C, the thermocompression pressure is preferably in the range of 0.098MPa to 1.77MPa, more preferably 0.29MPa to 1.47MPa, and the thermocompression time is preferably in the range of 20 seconds to 400 seconds, more preferably 30 seconds to 300 seconds. The lamination may be carried out under reduced pressure conditions, preferably at a pressure of 26.7hPa or less.

[0184] The lamination can be performed using a commercially available vacuum laminator, such as a vacuum pressure laminator manufactured by Meiki Seisakusho Co., Ltd., a vacuum applicator manufactured by Nikko Materials Co., Ltd., or a batch vacuum pressure laminator.

[0185] After lamination, the laminated resin sheets may be smoothed under normal pressure (atmospheric pressure), for example, by pressing a thermocompression member from the support side. The pressing conditions for the smoothing treatment may be the same as the thermocompression conditions for lamination. The smoothing treatment may be performed using a commercially available laminator. Note that lamination and smoothing treatment may be performed consecutively using the commercially available vacuum laminator.

[0186] The support may be removed between step (I) and step (II), or after step (II). When a metal foil is used as the support, the conductor layer may be formed using the metal foil without peeling off the support. When a metal foil with a supporting substrate is used as the support, the supporting substrate (and the release layer) may be peeled off. Then, the conductor layer can be formed using the metal foil.

[0187] In step (II), the resin composition layer is cured (for example, by heat curing) to form an insulating layer made of a cured product of the resin composition. The curing conditions for the resin composition layer are not particularly limited, and conditions typically employed for forming insulating layers for printed wiring boards may be used.

[0188] For example, the thermal curing conditions for the resin composition layer vary depending on the type of resin composition, etc., but in one embodiment, the curing temperature is preferably 140° C. to 250° C., more preferably 150° C. to 240° C., and even more preferably 180° C. to 230° C. The curing time is preferably 5 minutes to 240 minutes, more preferably 10 minutes to 150 minutes, and even more preferably 15 minutes to 120 minutes.

[0189] Before thermally curing the resin composition layer, the resin composition layer may be preheated at a temperature lower than the curing temperature. For example, prior to thermally curing the resin composition layer, the resin composition layer may be preheated at a temperature of 50°C to 140°C, preferably 60°C to 135°C, more preferably 70°C to 130°C 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.

[0190] When manufacturing a printed wiring board, the following steps may be further performed: (III) drilling holes in the insulating layer, (IV) roughening the insulating layer, and (V) forming a conductor layer. These steps (III) to (V) may be performed according to various methods known to those skilled in the art and used in manufacturing printed wiring boards. When the support is removed after step (II), the removal of the support may be performed between steps (II) and (III), between steps (III) and (IV), or between steps (IV) and (V). Furthermore, if necessary, the formation of the insulating layer and the conductor layer in steps (I) to (V) may be repeated to form a multilayer wiring board.

[0191] In another embodiment, the printed wiring board of the present invention can be produced using the above-mentioned prepreg. The production method is basically the same as when a resin sheet is used.

[0192] Step (III) is a step of drilling holes in the insulating layer, thereby forming holes such as via holes and through holes in the insulating layer. Step (III) may be performed using, for example, a drill, a laser, plasma, or the like, depending on the composition of the resin composition used to form the insulating layer. The dimensions and shape of the holes may be determined appropriately depending on the design of the printed wiring board.

[0193] Step (IV) is a step of roughening the insulating layer. Usually, in this step (IV), smear removal (desmear) is also performed. The procedure and conditions of the roughening treatment are not particularly limited, and known procedures and conditions commonly used in forming insulating layers for printed wiring boards can be adopted. For example, the insulating layer can be roughened by performing a swelling treatment with a swelling liquid, a roughening treatment with an oxidizing agent, and a neutralization treatment with a neutralizing liquid in this order.

[0194] The swelling liquid used in the roughening treatment is not particularly limited, but examples thereof include alkaline solutions and surfactant solutions, and is preferably an alkaline solution, with sodium hydroxide solution and potassium hydroxide solution being more preferred. Commercially available swelling liquids include "Swelling Dip Securigance P" and "Swelling Dip Securigance SBU" manufactured by Atotech Japan. The swelling treatment using a swelling liquid is not particularly limited, but can be carried out by, for example, immersing the insulating layer in a swelling liquid at 30°C to 90°C for 1 to 20 minutes. To keep the swelling of the resin in 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 to 15 minutes.

[0195] The oxidizing agent used in the roughening treatment is not particularly limited, but examples thereof include alkaline permanganate solutions prepared by dissolving potassium permanganate or sodium permanganate in an aqueous solution of sodium hydroxide. Roughening treatment using an oxidizing agent such as alkaline permanganate solution is preferably carried out by immersing the insulating layer in an oxidizing agent solution heated to 60°C to 100°C for 10 to 30 minutes. The concentration of permanganate in the alkaline permanganate solution is preferably 5% by mass to 10% by mass. Commercially available oxidizing agents include alkaline permanganate solutions such as "Concentrate Compact CP" and "Dosing Solution Securigance P" manufactured by Atotech Japan.

[0196] The neutralizing solution used in the roughening treatment is preferably an acidic aqueous solution, and examples of commercially available products include "Reduction Solution Securigant P" manufactured by Atotech Japan.

[0197] Treatment with a neutralizing solution can be carried out by immersing the surface that has been roughened with an oxidizing agent in a neutralizing solution at 30° C. to 80° C. for 5 to 30 minutes. From the standpoint of workability, etc., a method in which the object that has been roughened with an oxidizing agent is immersed in a neutralizing solution at 40° C. to 70° C. for 5 to 20 minutes is preferred.

[0198] Step (V) is a step of forming a conductor layer, and the conductor layer is formed on the insulating layer. 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 alloy layers include layers formed from alloys of two or more metals selected from the above group (e.g., nickel-chromium alloys, copper-nickel alloys, and copper-titanium alloys). Among these, 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 a nickel-chromium alloy, a copper-nickel alloy, or a 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 a nickel-chromium alloy is more preferred, and a single metal layer of copper is even more preferred.

[0199] The conductor layer may have a single layer structure or a multi-layer structure in which two or more single metal layers or alloy layers made of different types of metals or alloys are laminated. When the conductor layer has a multi-layer structure, the layer in contact with the insulating layer is preferably a single metal layer of chromium, zinc, or titanium, or an alloy layer of a nickel-chromium alloy.

[0200] The thickness of the conductor layer depends on the desired design of the printed wiring board, but is generally 3 μm to 35 μm, preferably 5 μm to 30 μm.

[0201] In one embodiment, the conductor layer may be formed by plating. From the viewpoint of facilitating the formation of fine wiring, it is preferable to form the conductor layer by a semi-additive method. An example of forming the conductor layer by a semi-additive method will be described below.

[0202] First, a plating seed layer is formed on the surface of an insulating layer by electroless plating. Next, a mask pattern is formed on the formed plating seed layer, exposing a portion of the plating seed layer corresponding to the desired wiring pattern. After a metal layer is formed on the exposed plating seed layer by electrolytic plating, the mask pattern is removed. Thereafter, unnecessary plating seed layer is removed by etching or the like, thereby forming a conductor layer having the desired wiring pattern.

[0203] In another embodiment, the conductor layer may be formed using a metal foil. When a metal foil is used to form the conductor layer, step (V) is preferably performed between steps (I) and (II). For example, after step (I), the support is removed, and a metal foil is laminated on the exposed surface of the 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. Thereafter, a conductor layer having a desired wiring pattern can be formed using the metal foil on the insulating layer by a conventional known technique such as a modified semi-additive method.

[0204] The metal foil can be produced by a known method such as an electrolytic method, a rolling method, etc. Examples of commercially available metal foils include HLP foil and JXUT-III foil manufactured by JX Nippon Mining & Metals Corporation, and 3EC-III foil and TP-III foil manufactured by Mitsui Kinzoku Co., Ltd.

[0205] Alternatively, when a metal foil or a metal foil with a supporting substrate is used as the support for the resin sheet, the conductor layer may be formed using the metal foil, as described above.

[0206] <Rewiring substrate for semiconductor packages> In one embodiment, the circuit board of the present invention is a rewiring substrate (rewiring layer) of a semiconductor package. Hereinafter, a method for manufacturing a semiconductor package will be described.

[0207] The semiconductor package includes an insulating layer made of a cured product of the resin composition of the present invention as an insulating layer of a rewiring substrate. The semiconductor package may also include a sealing layer made of a cured product of the resin composition of the present invention.

[0208] A semiconductor package can be produced, for example, by a method including the following steps (1) to (6) using the resin composition and resin sheet of the present invention. The resin composition and resin sheet of the present invention can be used to form a rewiring formation layer (insulating layer for forming a rewiring substrate) in step (5) or a sealing layer in step (3). An example of forming a rewiring formation layer or a sealing layer using a resin composition or a resin sheet will be shown below. However, techniques for forming a rewiring formation layer or a sealing layer for a semiconductor package are known, and a person skilled in the art can produce a semiconductor package using the resin composition and resin sheet of the present invention according to known techniques. (1) a step of laminating a temporary fixing film on a substrate; (2) a step of temporarily fixing a semiconductor chip on a temporary fixing film; (3) forming an encapsulation layer on the semiconductor chip; (4) peeling the substrate and the temporary fixing film from the semiconductor chip; (5) forming a rewiring formation layer as an insulating layer on the surface of the semiconductor chip from which the base material and the temporary fixing film have been peeled off; and (6) A step of forming a rewiring layer as a conductor layer on the rewiring formation layer.

[0209] -Process (1)- The material used for the substrate is not particularly limited. Examples of the substrate include semiconductor wafers such as silicon wafers, glass wafers, glass substrates, metal substrates such as copper, titanium, stainless steel, and cold-rolled steel sheets (SPCC), substrates in which glass fibers are impregnated with epoxy resin or the like and then thermoset (e.g., FR-4 substrates), and substrates made of bismaleimide triazine resin (BT resin).

[0210] The material of the temporary fixing film is not particularly limited as long as it can be peeled off from the semiconductor chip in step (4) and can temporarily fix the semiconductor chip. Commercially available products can be used as the temporary fixing film. Examples of commercially available products include Riva Alpha manufactured by Nitto Denko Corporation.

[0211] -Process (2)- The semiconductor chips can be temporarily fixed using known devices such as a flip chip bonder, a die bonder, etc. The layout and number of semiconductor chips to be arranged can be appropriately set depending on the shape and size of the temporary fixing film, the number of semiconductor packages to be produced, etc., and for example, the semiconductor chips can be temporarily fixed by arranging them in a matrix of multiple rows and multiple columns.

[0212] -Process (3)- The resin composition layer of the resin sheet of the present invention is laminated on a semiconductor chip, or the resin composition of the present invention is applied to a semiconductor chip and cured (for example, thermally cured) to form a sealing layer.

[0213] For example, lamination of a semiconductor chip and a resin sheet can be performed by removing the protective film from the resin sheet and then thermocompressing the resin sheet to the semiconductor chip from the support side. Examples of a member for thermocompressing the resin sheet to the semiconductor chip (hereinafter also referred to as a "thermocompression member") include a heated metal plate (such as a SUS plate) or a metal roll (SUS roll). It is preferable to press the thermocompression member not directly onto the resin sheet, but via an elastic material such as heat-resistant rubber, so that the resin sheet can adequately conform to the surface irregularities of the semiconductor chip. The semiconductor chip and resin sheet can also be laminated by a vacuum lamination method, and the lamination conditions and preferred ranges are the same as those described in relation to the method for manufacturing a printed wiring board.

[0214] After lamination, the resin composition is thermally cured to form the sealing layer under the same conditions as those described in relation to the method for producing a printed wiring board.

[0215] The support of the resin sheet may be peeled off after the resin sheet is laminated on the semiconductor chip and thermally cured, or the support may be peeled off before the resin sheet is laminated on the semiconductor chip.

[0216] When forming a sealing layer by applying the resin composition of the present invention, the application conditions are the same as the application conditions when forming the resin composition layer described in relation to the resin sheet of the present invention, and the preferred ranges are also the same.

[0217] -Process (4)- The method for peeling off the substrate and the temporary fixing film can be changed as appropriate depending on the material of the temporary fixing film, etc., and examples include a method in which the temporary fixing film is heated and foamed (or expanded) to peel it off, and a method in which ultraviolet light is irradiated from the substrate side to reduce the adhesive strength of the temporary fixing film and peel it off.

[0218] In the method of heating and foaming (or expanding) the temporary fixing film to peel it off, the heating conditions are usually 100 to 250°C for 1 to 90 seconds or 5 to 15 minutes. In the method of irradiating ultraviolet light from the substrate side to reduce the adhesive strength of the temporary fixing film to peel it off, the irradiation dose of ultraviolet light is usually 10 mJ / cm. 2 ~1000mJ / cm 2 is.

[0219] -Process (5)- The resin composition and resin sheet of the present invention are used to form a rewiring formation layer (insulating layer of a rewiring substrate).

[0220] After forming the redistribution layer, via holes may be formed in the redistribution layer to connect the semiconductor chip to a conductor layer (described later). The via holes may be formed by a known method depending on the material of the redistribution layer.

[0221] -Process (6)- The formation of the conductor layer on the rewiring formation layer may be carried out in the same manner as in step (V) described in relation to the method for producing a printed wiring board. Note that steps (5) and (6) may be repeated to alternately stack (build up) the conductor layer (rewiring layer) and the rewiring formation layer (insulating layer).

[0222] The manufacturing of the semiconductor package may further include steps of (7) forming a solder resist layer on the conductor layer (rewiring layer), (8) forming bumps, and (9) dicing the multiple semiconductor packages into individual semiconductor packages. These steps may be performed according to various methods known to those skilled in the art that are used in the manufacturing of semiconductor packages.

[0223] By forming a rewiring formation layer (insulating layer) using the resin composition or resin sheet of the present invention, which exhibits low viscosity and can produce a cured product that exhibits good adhesion to a conductor layer when exposed to a high-temperature, high-humidity environment, a semiconductor package with extremely low transmission loss can be realized without concern for reduced conductor adhesion, regardless of whether the semiconductor package is a fan-in package or a fan-out package. In one embodiment, the semiconductor package of the present invention is a fan-out package. The resin composition or resin sheet of the present invention can be applied to both a fan-out panel level package (FOPLP) and a fan-out wafer level package (FOWLP). In one embodiment, the semiconductor package of the present invention is a fan-out panel level package (FOPLP) or a fan-out wafer level package (FOWLP).

[0224] [Semiconductor Devices] The semiconductor device of the present invention includes a layer made of a cured product of the resin composition layer of the present invention. The semiconductor device of the present invention can be produced using the circuit board of the present invention.

[0225] Examples of semiconductor devices include various semiconductor devices used in electrical appliances (for example, computers, mobile phones, digital cameras, and televisions) and vehicles (for example, motorcycles, automobiles, trains, ships, and aircraft). [Example]

[0226] The present invention will be described in more detail below with reference to examples. The present invention is not limited to these examples. In the following, "parts" and "%" representing amounts mean "parts by mass" and "% by mass", respectively, unless otherwise specified.

[0227] <Synthesis Example 1: Synthesis of Epoxy Resin A> According to the method described in Japanese Patent No. 2539648, the phenolic hydroxyl groups of 3,3'-diallyl-4,4'-dihydroxybiphenyl were glycidyl etherified using epichlorohydrin, and then the allyl groups were oxidized (oxiranated) using peracetic acid to obtain Epoxy Resin A. Epoxy Resin A had a structure represented by the following formula (A), and its epoxy group equivalent weight was approximately 115 and molecular weight was approximately 430.

[0228] [ka]

[0229] <Synthesis Example 2: Synthesis of Epoxy Resin B> According to the method described in Japanese Patent No. 2539648, the phenolic hydroxyl groups of 2,2'-diallylbisphenol A were glycidyl etherified with epichlorohydrin, and then the allyl groups were oxidized with peracetic acid to obtain epoxy resin B. This epoxy resin B had a structure represented by the following formula (B), and its epoxy group equivalent weight was approximately 130 and molecular weight was approximately 490.

[0230] [ka]

[0231] <Synthesis Example 3: Synthesis of Epoxy Resin C> According to the method described in Japanese Patent No. 2539648, the phenolic hydroxyl groups of 2,2'-diallylbisphenol F were glycidyl etherified with epichlorohydrin, and then the allyl groups were oxidized with peracetic acid to obtain epoxy resin C. This epoxy resin C had a structure represented by the following formula (C), and its epoxy group equivalent weight was approximately 120 and molecular weight was approximately 450.

[0232] [ka]

[0233] <Synthesis Example 4: Synthesis of Epoxy Resin D> According to the method described in Japanese Patent No. 2539648, the phenolic hydroxyl groups of 3,3'-diallyl-4,4'-dihydroxydiphenyl sulfone were glycidyl etherified with epichlorohydrin, and then the allyl groups were oxidized with peracetic acid to obtain Epoxy Resin D. Epoxy Resin D had a structure represented by the following formula (D), and its epoxy group equivalent weight was approximately 140 and molecular weight was approximately 520.

[0234] [ka]

[0235] <Synthesis Example 5: Synthesis of Epoxy Resin E> According to the method described in Japanese Patent No. 2539648, the phenolic hydroxyl groups of honokiol (3',5-diallyl-2,4'-dihydroxybiphenyl) were glycidyl etherified using epichlorohydrin, and then the allyl groups were oxidized using peracetic acid to obtain Epoxy Resin E. Epoxy Resin E had a structure represented by the following formula (E), and its epoxy group equivalent weight was approximately 115 and molecular weight was approximately 430.

[0236] [ka]

[0237] <Synthesis Example 6: Synthesis of Epoxy Resin F> 58 g of 2,2',4,4'-tetrahydroxybenzophenone was dissolved in 1050 g of epichlorohydrin, and 0.25 g of benzyltriethylammonium chloride was added. 90 g of 48% aqueous sodium hydroxide was added dropwise over 5 hours at 70°C under reduced pressure. The resulting water was removed from the system by azeotropy with epichlorohydrin, and the distilled epichlorohydrin was returned to the system. After the addition, the reaction was continued for 2 hours, after which the resulting salt was removed by filtration. After further washing with water, the epichlorohydrin was distilled off. The resulting epoxy resin was dissolved in 400 g of methyl isobutyl ketone, and 10 g of 10% aqueous sodium hydroxide was added at 85°C and reacted for 2 hours. After the reaction, the mixture was filtered, washed with water, and the methyl isobutyl ketone was distilled off, yielding 155 g of pale yellow solid epoxy resin F. The epoxy resin F had a structure represented by the following formula (F), and its epoxy group equivalent was about 130 and molecular weight was about 490.

[0238] [ka]

[0239] [Example 1] (1) Preparation of Resin Composition 1 10 parts of the epoxy resin A synthesized in Synthesis Example 1 and 20 parts of a biphenyl type epoxy resin ("NC3000" manufactured by Nippon Kayaku Co., Ltd., epoxy group equivalent weight: approximately 277) were dissolved in 20 parts of toluene and 20 parts of MEK by heating with stirring. The resulting solution was cooled to room temperature and then mixed with 65 parts of an active ester resin (DIC Corporation's "HP-B-8151-62T," active group equivalent weight 238, a toluene solution with a solid content of 62% by mass), 6 parts of a triazine skeleton-containing phenolic curing agent (DIC Corporation's "LA-3018-50P," a hydroxyl group equivalent weight approximately 151, a 2-methoxypropanol solution with a solid content of 50%), 10 parts of a phenoxy resin (Mitsubishi Chemical Corporation's "YX6954BH30," a MEK-cyclohexanone mixed solution with a solid content of 30%), 5 parts of a curing accelerator (Shikoku Chemical Industry Co., Ltd.'s "1B2PZ," a MEK solution with a solid content of 10%), and an inorganic filler (spherical silica (Admatechs Co., Ltd.'s "SO-C2," an average particle size of 0.5 μm, a specific surface area of ​​5.8 m) surface-treated with an amine-based silane coupling agent (Shin-Etsu Chemical Co., Ltd.'s "KBM573")).2 The mixture was mixed and uniformly dispersed in a high-speed rotating mixer to obtain a resin composition.

[0240] (2) Preparation of resin sheet As a support, a polyethylene terephthalate film ("Lumirror R80" manufactured by Toray Industries, Inc., thickness 38 μm, softening point 130°C) whose surface had been subjected to a release treatment with an alkyd resin-based release agent ("AL-5" manufactured by Lintec Corporation) was prepared. Resin composition 1 was uniformly applied to this support using a die coater so that the thickness of the resin composition layer after drying would be 40 μm, and the film was dried at 70 to 100°C for 3 minutes to form a resin composition layer on the support. Next, a rough surface of a polypropylene film ("Alphan MA-411" manufactured by Oji F-Tex Co., Ltd., thickness 15 μm) was attached as a protective film to the side of the resin composition layer not bonded to the support. This resulted in a resin sheet having a layer structure of support / resin composition layer / protective film.

[0241] [Example 2] Resin composition 2 was prepared in the same manner as in Example 1, except that 6 parts of a carbodiimide-based curing agent ("V-03" manufactured by Nisshinbo Chemical Inc., active group equivalent weight approximately 216, toluene solution with a solid content of 50%) was further added, and a resin sheet was obtained.

[0242] [Example 3] Resin composition 3 was prepared in the same manner as in Example 1, except that 3 parts of a bismaleimide resin ("BMI-689" manufactured by Designer Molecules, maleimide group equivalent weight: approximately 345) was further added, and a resin sheet was obtained.

[0243] [Example 4] Resin composition 4 was prepared in the same manner as in Example 1, except that 3 parts of a bismaleimide resin ("BMI-1500" manufactured by Designer Molecules, maleimide group equivalent weight: approximately 750) was further added, and a resin sheet was obtained.

[0244] [Example 5] Resin composition 5 was prepared in the same manner as in Example 1, and a resin sheet was obtained, except that 4.3 parts of an MEK solution (solid content 70% by mass) of a maleimide resin (hereinafter also referred to as "maleimide resin G") synthesized by the method described in Synthesis Example 1 of the Japan Institute of Invention and Innovation Disclosure Technical Bulletin No. 2020-500211 was further added.

[0245] [Example 6] (1) Preparation of Resin Composition 6 10 parts of the epoxy resin B synthesized in Synthesis Example 2 and 20 parts of a biphenyl type epoxy resin ("NC3000" manufactured by Nippon Kayaku Co., Ltd., epoxy group equivalent weight: approximately 277) were dissolved in 20 parts of toluene and 20 parts of MEK by heating with stirring. The resulting solution was cooled to room temperature and then mixed with 65 parts of an active ester resin (DIC Corporation "HP-B-8151-62T", active group equivalent weight 238, 62% solids in a toluene solution), 6 parts of a triazine skeleton-containing phenolic curing agent (DIC Corporation "LA-3018-50P", hydroxyl group equivalent weight approximately 151, 50% solids in a 2-methoxypropanol solution), 10 parts of a phenoxy resin (Mitsubishi Chemical Corporation "YX6954BH30", 30% solids in a MEK-cyclohexanone mixed solution), 6 parts of a carbodiimide curing agent (Nisshinbo Chemical Inc. "V-03", active group equivalent weight approximately 216, 50% solids in a toluene solution), and bismaleimide resin (Designer Resin composition 6 was prepared by mixing 3 parts of "BMI-1500" manufactured by Shikoku Chemical Industries, Ltd. (maleimide group equivalent weight: approximately 750), 5 parts of a curing accelerator (MEK solution of "1B2PZ" manufactured by Shikoku Chemical Industries, Ltd. with a solids content of 10%), and 210 parts of an inorganic filler (spherical silica ("SO-C2" manufactured by Admatechs Co., Ltd.) surface-treated with an amine-based silane coupling agent ("KBM573" manufactured by Shin-Etsu Chemical Co., Ltd.)) and uniformly dispersing the mixture using a high-speed rotary mixer.

[0246] (2) Preparation of resin sheet A resin sheet was produced in the same manner as in Example 1 using the resin composition 6 prepared in (1) above.

[0247] [Example 7] Resin composition 7 was prepared in the same manner as in Example 2, except that 10 parts of epoxy resin C synthesized in Synthesis Example 3 was used instead of 10 parts of epoxy resin A, and a resin sheet was obtained.

[0248] [Example 8] Resin composition 8 was prepared in the same manner as in Example 2, except that 10 parts of epoxy resin D synthesized in Synthesis Example 4 was used instead of 10 parts of epoxy resin A, and a resin sheet was obtained.

[0249] [Example 9] Resin composition 9 was prepared in the same manner as in Example 2, except that 10 parts of epoxy resin E synthesized in Synthesis Example 5 was used instead of 10 parts of epoxy resin A, and a resin sheet was obtained.

[0250] [Example 10] Resin composition 10 was prepared in the same manner as in Example 2, except that 10 parts of epoxy resin F synthesized in Synthesis Example 6 was used instead of 10 parts of epoxy resin A, and a resin sheet was obtained.

[0251] [Example 11] Resin composition 11 was prepared in the same manner as in Example 4, except that 62 parts of an active ester resin ("HPC-8000-65T" manufactured by DIC Corporation, active group equivalent weight: approximately 223 g, solid content: 65% by mass in toluene solution) was used instead of 65 parts of an active ester resin ("HP-B-8151-62T" manufactured by DIC Corporation, active group equivalent weight: 238, solid content: 62% by mass in toluene solution). A resin sheet was obtained.

[0252] [Example 12] (1) Preparation of Resin Composition 12 Ten parts of the epoxy resin A synthesized in Synthesis Example 1 and 20 parts of a biphenyl-type epoxy resin ("NC3000" manufactured by Nippon Kayaku Co., Ltd., epoxy group equivalent: approximately 277) were heated and dissolved in 20 parts of toluene and 20 parts of MEK while stirring. The resulting solution was cooled to room temperature and then mixed with 62 parts of an active ester-based curing agent ("HPC-8000-65T" manufactured by DIC Corporation, active group equivalent: approximately 223 g, toluene solution with a solid content of 65% by mass), 6 parts of a triazine skeleton-containing phenol-based curing agent ("LA-3018-50P" manufactured by DIC Corporation, hydroxyl group equivalent: approximately 151, 2-methoxypropanol solution with a solid content of 50%), and phenoxy resin (manufactured by Mitsubishi Chemical Corporation). The mixture consisted of 50 parts of a 30% solids MEK-cyclohexanone mixed solution ("YX6954BH30" manufactured by Shikoku Chemical Industries Co., Ltd., 5 parts of a curing accelerator (10% solids MEK solution of "1B2PZ" manufactured by Shikoku Chemical Industries Co., Ltd.), 5 parts of an inorganic filler (spherical silica ("UFP-30" manufactured by Denka Co., Ltd., average particle size 0.3 μm, specific surface area 30.7 m) surface-treated with a phenylaminosilane coupling agent ("KBM573" manufactured by Shin-Etsu Chemical Co., Ltd.)). 2 The mixture was mixed and uniformly dispersed in a high-speed rotating mixer to obtain Resin Composition 12.

[0253] (2) Preparation of resin sheet A resin sheet was produced in the same manner as in Example 1 using the resin composition 12 prepared in (1) above.

[0254] [Example 13] (1) Preparation of Resin Composition 13 Thirty parts of the epoxy resin A synthesized in Synthesis Example 1 and 10 parts of a biphenyl-type epoxy resin ("NC3000" manufactured by Nippon Kayaku Co., Ltd., epoxy group equivalent: approximately 277) were heated and dissolved in 20 parts of toluene and 20 parts of MEK while stirring. The resulting solution was cooled to room temperature and then mixed with 65 parts of an active ester-based curing agent ("HP-B-8151-62T" manufactured by DIC Corporation, active group equivalent: 238, solids content: 62% by mass in a toluene solution), 6 parts of a triazine skeleton-containing phenol-based curing agent ("LA-3018-50P" manufactured by DIC Corporation, hydroxyl group equivalent: approximately 151, solids content: 50% in a 2-methoxypropanol solution), and 6 parts of a carbodiimide-based curing agent ("V-03" manufactured by Nisshinbo Chemical Inc., active group equivalent: approximately 216, solids content: 50% in a toluene solution). 16.7 parts of phenoxy resin ("YX6954BH30" manufactured by Mitsubishi Chemical Corporation, a 30% solids MEK-cyclohexanone mixed solution), 5 parts of curing accelerator ("1B2PZ" manufactured by Shikoku Chemical Industry Co., Ltd., a 10% solids MEK solution), and 105 parts of inorganic filler (spherical silica ("UFP-30" manufactured by Denka Company Limited) surface-treated with a phenylaminosilane coupling agent ("KBM573" manufactured by Shin-Etsu Chemical Co., Ltd.)) were mixed and uniformly dispersed using a high-speed rotating mixer to obtain resin composition 13.

[0255] (2) Preparation of resin sheet A resin sheet was produced in the same manner as in Example 1 using the resin composition 13 prepared in (1) above.

[0256] [Comparative Example 1] Resin composition C1 was prepared in the same manner as in Example 1, except that 10 parts of bisphenol-type epoxy resin ("828US" manufactured by Mitsubishi Chemical Corporation, epoxy group equivalent weight approximately 188) was used instead of 10 parts of epoxy resin A, and a resin sheet was obtained.

[0257] Comparative Example 2 Resin composition C2 was prepared in the same manner as in Example 1, except that 10 parts of naphthalene-type tetrafunctional epoxy resin ("HP-4700" manufactured by DIC Corporation, epoxy group equivalent weight: approximately 162) was used instead of 10 parts of epoxy resin A, and a resin sheet was obtained.

[0258] Comparative Example 3 Resin composition C3 was prepared in the same manner as in Example 1, except that 10 parts of bixylenol-type epoxy resin ("YX4000HK" manufactured by Mitsubishi Chemical Corporation, epoxy group equivalent weight approximately 194) was used instead of 10 parts of epoxy resin A, and a resin sheet was obtained.

[0259] Comparative Example 4 Resin composition C4 was prepared in the same manner as in Example 12, except that 10 parts of a pentaerythritol-type epoxy resin ("Showfree (registered trademark) PETG" manufactured by Showa Denko K.K., epoxy group equivalent weight: approximately 95) was used instead of 10 parts of epoxy resin A, and a resin sheet was obtained.

[0260] <Measurement of the average particle size of inorganic fillers> 100 mg of inorganic filler, 0.1 g of dispersant (San Nopco "SN9228"), and 10 g of methyl ethyl ketone were weighed into a vial and dispersed ultrasonically for 10 minutes. Using a laser diffraction particle size distribution analyzer (Horiba, Ltd. "LA-960"), blue and red light wavelengths were used as light sources, and the volumetric particle size distribution was measured using a flow cell method. The average particle size was calculated as the median diameter from the particle size distribution obtained.

[0261] <Measurement of peel strength of plated conductor layer> (1) Preparation of inner layer board Both sides of a glass cloth-based epoxy resin double-sided copper-clad laminate (copper foil thickness 18 μm, substrate thickness 0.8 mm, Panasonic "R1515A") with an inner layer circuit formed on it were etched 1 μm deep with a microetching agent (MEC "CZ8101") to roughen the copper surface.

[0262] (2) Lamination of resin sheets The protective film was peeled off from the resin sheets obtained in the Examples and Comparative Examples to expose the resin composition layer. Using a batch-type vacuum pressure laminator (Nikko Materials Co., Ltd., two-stage build-up laminator "CVP700"), the resin composition layer was laminated on both sides of the inner layer substrate so that it was in contact with the inner layer substrate. Lamination was performed by reducing the pressure for 30 seconds to 13 hPa or less, followed by pressure bonding at 120°C and a pressure of 0.74 MPa for 30 seconds. The laminate was then heat-pressed at 100°C and a pressure of 0.5 MPa for 60 seconds to smooth the surface.

[0263] (3) Thermal curing of the resin composition layer The inner layer substrate with the resin sheet laminated thereon was then placed in an oven at 130°C and heated for 30 minutes, and then transferred to an oven at 180°C and heated for 30 minutes to thermally cure the resin composition layer and form an insulating layer. The support was then peeled off to obtain a cured substrate having a structure of insulating layer / inner layer substrate / insulating layer.

[0264] (4) Roughening treatment The cured substrate was subjected to a desmear treatment as a roughening treatment, which was the following wet desmear treatment. (wet desmear treatment) The cured substrate was immersed in a swelling solution (Atotech Japan's "Swelling Dip Securigant P," an aqueous solution of diethylene glycol monobutyl ether and sodium hydroxide) at 60°C for 5 minutes, then in an oxidizing solution (Atotech Japan's "Concentrate Compact CP," an aqueous solution of approximately 6% potassium permanganate and 4% sodium hydroxide) at 80°C for 15 minutes, and finally in a neutralizing solution (Atotech Japan's "Reduction Solution Securigant P," an aqueous sulfuric acid solution) at 40°C for 5 minutes. The substrate was then dried at 80°C for 15 minutes. The resulting substrate is referred to as the roughened substrate.

[0265] (5) Formation of the conductor layer A conductor layer was formed on the surface of the roughened substrate using the semi-additive method. Specifically, the roughened substrate was immersed in an electroless plating solution containing PdCl2 at 40°C for 5 minutes, and then in an electroless copper plating solution at 25°C for 20 minutes. After heating at 150°C for 30 minutes for annealing, an etching resist was formed and a pattern was formed by etching. Copper sulfate electroplating was then performed to form a 30 μm-thick conductor layer, which was then annealed at 200°C for 60 minutes. The resulting substrate is referred to as evaluation substrate A.

[0266] (6) Measurement of peel strength of plated conductor layer The peel strength of the plated conductor layer was measured in accordance with the Japanese Industrial Standard (JIS C6481). Specifically, a 10 mm wide, 100 mm long cut was made in the conductor layer of evaluation board A, one end of the cut was peeled off and gripped with a gripper. The load (kgf / cm) when 35 mm was peeled off vertically at a rate of 50 mm / min at room temperature was measured. A tensile tester (TSE "AC-50C-SL") was used for the measurement.

[0267] <Measurement of copper foil peel strength after high temperature and humidity environmental test (HAST)> (1) Copper foil surface preparation The shiny side of Mitsui Kinzoku's "3EC-III" (electrolytic copper foil, 35 μm) was etched by 1 μm with a microetching agent (Mec Co., Ltd.'s "CZ8101") to roughen the copper surface, and then an anti-rust treatment (CL8300) was applied. Furthermore, the foil was heated in an oven at 130°C for 30 minutes. The resulting copper foil is called CZ copper foil.

[0268] (2) Preparation of inner layer board Both sides of a glass cloth-based epoxy resin double-sided copper-clad laminate (copper foil thickness 18 μm, substrate thickness 0.8 mm, Panasonic "R1515A") with an inner layer circuit formed on it were etched 1 μm deep with a microetching agent (MEC "CZ8101") to roughen the copper surface.

[0269] (3) Preparation of evaluation board The protective film was peeled off from the resin sheets obtained in the Examples and Comparative Examples to expose the resin composition layer. Using a batch-type vacuum pressure laminator (Nikko Materials Co., Ltd., two-stage build-up laminator "CVP700"), the resin composition layer was laminated on both sides of the inner layer substrate so that it was in contact with the inner layer substrate. Lamination was performed by reducing the pressure for 30 seconds to 13 hPa or less, followed by pressure bonding at 120°C and a pressure of 0.74 MPa for 30 seconds. The laminate was then smoothed by heat pressing at 100°C and a pressure of 0.5 MPa for 60 seconds. After smoothing, the support was peeled off. The treated side of the CZ copper foil was laminated on the exposed resin composition layer under the same conditions as above. The resin composition layer was then cured at 200°C for 90 minutes to form an insulating layer, producing evaluation substrate B with a structure of CZ copper foil / insulating layer / inner layer substrate / insulating layer / CZ copper foil.

[0270] (4) Measurement of copper foil peel strength after HAST The obtained evaluation board B was subjected to a 100-hour high-temperature, high-humidity environmental test at 130°C and 85% RH using a highly accelerated life tester (Kusumoto Chemicals, PM422). The peel strength of the copper foil was then measured in accordance with JIS C6481, in the same manner as in the measurement of the peel strength of the plated conductor layer described above. Specifically, one edge of the copper foil was peeled off and held with a gripper (TSE, Autocom type testing machine, AC-50C-SL). The load (kgf / cm) was measured using an Instron universal testing machine at room temperature when 35 mm was peeled off vertically at a rate of 50 mm / min.

[0271] <Measurement of minimum melt viscosity> The dynamic viscoelasticity of the resin composition layers of the resin sheets obtained in the examples and comparative examples was measured using a dynamic viscoelasticity measuring device (Rheosol-G3000 manufactured by UBM Co., Ltd.) The measurement was carried out from a starting temperature of 60°C to 200°C at a temperature increase rate of 5°C / min, an interval temperature of 2.5°C, and a frequency of 1 Hz / deg, and was evaluated according to the following criteria. 〇:3000poise or less ×: Over 3000poise

[0272] <Measurement of glass transition temperature (Tg)> (1) Preparation of cured product for evaluation The release agent-treated surface of a release agent-treated PET film ("501010" manufactured by Lintec, 50 μm thick, 240 mm square) was placed on a glass cloth-based epoxy resin double-sided copper-clad laminate ("R5715ES" manufactured by Panasonic, 0.7 mm thick, 255 mm square), with the release agent-untreated surface of the film being placed on top of the glass cloth-based epoxy resin double-sided copper-clad laminate ("R5715ES" manufactured by Panasonic, 0.7 mm thick, 255 mm square), and the four sides were fixed with polyimide adhesive tape (10 mm wide) (hereinafter also referred to as "fixed PET film"). Next, resin compositions 1 to 13 and C1 to C4 prepared in the examples and comparative examples were applied to the release-treated surface of the fixed PET film using an applicator so that the thickness of the resin composition layer after drying would be 40 μm, and the resin sheet was obtained by drying at 70°C to 100°C (average 100°C) for 3 minutes. The resin composition layer was then thermally cured by placing it in a 190°C oven and heating for 90 minutes. After thermal curing, the polyimide adhesive tape was peeled off, and the cured product was removed from the glass cloth-based epoxy resin double-sided copper-clad laminate. The PET film ("501010" manufactured by Lintec Corporation) was also peeled off, yielding a sheet-like cured product. The resulting cured product is referred to as the "cured product for evaluation."

[0273] (2) Measurement of glass transition temperature The cured product for evaluation was cut into test pieces approximately 5 mm wide and 15 mm long, and thermomechanical analysis was performed using a thermomechanical analyzer (Rigaku Corporation, "Thermo Plus TMA8310") using the tensile load method. After mounting the test piece in the analyzer, measurements were performed twice consecutively under the measurement conditions of a load of 1 g and a heating rate of 5°C / min. The glass transition temperature (Tg) was measured in the second measurement, and evaluation was performed based on the following criteria. 〇: Glass transition temperature is 150℃ or higher ×: Glass transition temperature is less than 150°C

[0274] The results of Examples 1 to 13 and Comparative Examples 1 to 4 are shown in Table 1.

[0275] [Table 1]

Claims

1. An epoxy resin, The component (A-1) contains 10% by mass or more of a polyfunctional epoxy resin represented by formula (2), when the resin component in the resin composition is taken as 100% by mass, As component (A-2), other epoxy resins (excluding those corresponding to component (A-1)), and A resin composition comprising an active ester resin. 【Chemistry 1】 (In formula (2) Each X independently represents a monovalent organic group having an epoxy group, R Ｓ each independently represents a substituent, n1 represents an integer of 2 or more; n2 represents an integer of 0 or more, Here, n1 and n2 satisfy n1 + n2 ≦ 5, L represents a carbonyl group.

2. The polyfunctional epoxy resin is represented by the following formula (F): The resin composition according to claim 1. 【Chemistry 2】

3. The resin composition according to claim 1, wherein the polyfunctional epoxy resin is liquid at a temperature of 20°C.

4. The resin composition according to claim 1, wherein the polyfunctional epoxy resin has a molecular weight of 3,000 or less.

5. 2. The resin composition according to claim 1, wherein the active ester resin is an active ester resin containing a naphthalene structure or an active ester resin containing a dicyclopentadiene-type diphenol structure.

6. The resin composition according to claim 1 , further comprising an inorganic filler.

7. The resin composition according to claim 6, wherein the content of the inorganic filler is 40% by mass or more when the nonvolatile components in the resin composition are 100% by mass.

8. The resin composition according to claim 1, wherein the mass ratio of the active ester resin to the polyfunctional epoxy resin [active ester resin / polyfunctional epoxy resin] is 1 or more.

9. The resin composition according to claim 1, which is used for an insulating layer of a circuit board.

10. A resin sheet comprising a support and a layer of the resin composition according to any one of claims 1 to 9 provided on the support.

11. The resin sheet according to claim 10, wherein the support is a thermoplastic resin film or a metal foil.

12. A cured product of the resin composition described in any one of claims 1 to 9.

13. A circuit board comprising an insulating layer made of a cured product of the resin composition described in any one of claims 1 to 9.

14. A semiconductor device comprising the circuit board described in claim 13.

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