Resin sheet and printed wiring board

Abstract

The resin sheet according to the present invention comprises a supporting body, and a layer that is provided on the surface of the supporting body and that contains a resin composition. The resin composition contains a cyanic acid ester compound and / or a phenolic compound, and an epoxy compound and / or a maleimide compound. At least one selected from the group consisting of the cyanic acid ester compound, the phenolic compound, the epoxy compound, and the maleimide compound, contains a compound having a biphenyl backbone. In the case where the resin composition contains an inorganic filler, the contained amount of the inorganic filler is 60 parts by mass or less with respect to 100 parts by mass of a resin solid content in the resin composition. The Vickers hardness (HV: 0.01) of a cured product of the resin composition is 10-19, and the thickness of the layer containing the resin composition is 2-20 μm.

Description

Technical Field

[0001] The present invention relates to a resin sheet and a printed wiring board.

Background Art

[0002] In recent years, semiconductor packages widely used in electronic devices, communication devices, personal computers, etc. have seen an increasing acceleration in the high integration and high density mounting of each component as the devices become more highly functional, thinner, and smaller. Along with this, the required characteristics of printed wiring boards for semiconductor packages are becoming increasingly stringent. Examples of such required characteristics of printed wiring boards include low water absorption, moisture heat resistance, flame retardancy, low thermal expansion rate, chemical resistance, and high plating peel strength.

[0003] In addition to these characteristics, suppressing the warpage of the printed wiring board (achieving low warpage) has become an important issue, and various studies have been conducted. For example, Patent Document 1 describes a resin sheet having a support and an adhesive layer, which reduces warpage in a high temperature environment when applied to a printed wiring board.

[0004] In the insulating layer of a printed wiring board, it is also necessary to be excellent in heat resistance and electrical characteristics such as low dielectric constant and low dielectric tangent. As a resin used for the insulating layer, cyanate ester compounds are known, and resin compositions in which cyanate ester compounds are used in combination with epoxy resins and bismaleimide compounds, etc. are widely used. For example, Patent Document 2 describes that a resin composition containing a cyanate ester compound with a specific structure and other components is excellent in characteristics such as low water absorption and low thermal expansion rate.

[0005] Also, as a method for manufacturing a printed wiring board, a method by a build-up method in which an insulating layer and a conductor layer are alternately stacked on a core substrate is known. For forming the insulating layer, usually, a resin sheet, a build-up material, etc. are used (for example, Patent Document 3).

Prior Art Documents

Patent Document

[0006]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0007] However, in Patent Document 1, in order to reduce warpage by reducing the coefficient of thermal expansion, the warpage of the printed wiring board still cannot be sufficiently reduced. Therefore, further improvement is desired regarding the reduction of warpage.

[0008] The resin composition described in Patent Document 2 has good physical properties regarding characteristics such as low water absorption and low coefficient of thermal expansion. However, from the perspective of thermal conductivity, there is still room for improvement. Therefore, when used as an insulating material in a printed wiring board as a resin sheet, the heat resistance is insufficient and it is difficult to apply it as an insulating material.

[0009] In addition, with the increase in the functionality, thinning, and miniaturization of semiconductor packages, when each component for a semiconductor package is highly integrated and densely mounted, the number of build-up layers of a printed wiring board increases. However, when the number of build-up layers increases, problems such as cracks occurring on the surface of the insulating layer, the insulating layer cracking, and circuit distortion occur. In this regard, Patent Document 3 describes a build-up material with suppressed surface damage. However, in the build-up material described in Patent Document 3, since it contains a large amount of inorganic filler, the surface has a high hardness (Vickers hardness (HV0.01) of 32.8 or more and 93.9 or less). Therefore, even in this build-up material, cracks occur on the surface of the insulating layer, the insulating layer cracks, and circuit distortion occurs. Further, since the build-up material described in Patent Document 3 contains a large amount of inorganic filler, it is difficult to thin and miniaturize. Furthermore, due to the large amount of inorganic filler, the surface hardness is high, and there is also a problem of low peel strength.

[0010] The present invention has been made in view of the above problems, and an object thereof is to provide a resin sheet that can sufficiently reduce the warp of a printed wiring board (achieve low warp), is less likely to cause cracks in the insulating layer of the printed wiring board, so that cracks and circuit distortion in the insulating layer are less likely to occur, and can exhibit excellent heat resistance and high peel strength, and a printed wiring board.

Means for Solving the Problems

[0011] As a result of intensive studies to solve the above problems, the present inventors have found that by using a specific resin sheet, the warp of a printed wiring board can be sufficiently reduced, cracks are less likely to occur in the insulating layer of the printed wiring board, so that cracks and circuit distortion in the insulating layer are less likely to occur, and excellent heat resistance and high peel strength can be exhibited, and the present invention has been completed.

[0012] That is, the present invention is as follows. 〔1〕A resin sheet comprising a support and a layer containing a resin composition disposed on the surface of the support, The resin composition contains a cyanate ester compound and / or a phenol compound, and an epoxy compound and / or a maleimide compound, at least one selected from the group consisting of the cyanate ester compound, the phenol compound, the epoxy compound, and the maleimide compound contains a compound having a biphenyl skeleton, when the resin composition contains an inorganic filler, the content of the inorganic filler is 60 parts by mass or less with respect to 100 parts by mass of the resin solid content in the resin composition, the Vickers hardness (HV0.01) of the cured product of the resin composition is 10 or more and 19 or less, A resin sheet having a thickness of the layer containing the resin composition of 2 μm or more and 20 μm or less.

[0013] 〔2〕The content of the compound having a biphenyl skeleton is 15 parts by mass or more with respect to 100 parts by mass of the resin solid content in the resin composition, and when at least one selected from the group consisting of the cyanate ester compound, the phenol compound, the epoxy compound, and the maleimide compound contains a compound having a polycyclic aromatic group, the content of the compound having a polycyclic aromatic group is less than 40 parts by mass with respect to 100 parts by mass of the resin solid content in the resin composition. The resin sheet according to 〔1〕. 〔3〕The resin sheet according to 〔1〕 or 〔2〕, wherein the cyanate ester compound contains a compound represented by the following formula (1a).

[0014]

Chemical formula

[0015] (In formula (1a), R 1c each independently represents a hydrogen atom or a methyl group. n1 represents an integer of 1 or more and 10 or less.).

[0016] 〔4〕The resin sheet according to any one of 〔1〕 to 〔3〕, wherein the phenol compound contains a compound represented by the following formula (2a).

[0017]

Chem.

[0018] (In formula (2a), Ar 1 each independently represents a benzene ring or a naphthalene ring. Ar 2 represents a benzene ring, a naphthalene ring, or a biphenyl ring. R 2a each independently represents a hydrogen atom or a methyl group. m represents an integer of 1 or more and 50 or less. Each ring may have a substituent other than a hydroxyl group.).

[0019] [5] The resin sheet according to any one of [1] to [4], wherein the epoxy compound contains a compound represented by the following formula (3a).

[0020]

Chem.

[0021] (In formula (3a), Ar 3 each independently represents a benzene ring or a naphthalene ring. Ar 4 represents a benzene ring, a naphthalene ring, or a biphenyl ring. R 3a each independently represents a hydrogen atom or a methyl group. k represents an integer of 1 or more and 50 or less. Each ring may have a substituent other than a glycidyloxy group.).

[0022] [6] The resin sheet according to any one of [1] to [5], wherein the maleimide compound contains a compound represented by the following formula (4a).

[0023]

Chem.

[0024] (In formula (4a), R 4a and R 5a each independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. R 4bEach independently represents a hydrogen atom or a methyl group. s represents an integer of 1 or more.).

[0025] [7] The resin sheet according to any one of [1] to [6], wherein the thickness of the layer containing the resin composition is 2 μm or more and 15 μm or less. [8] The resin sheet according to any one of [1] to [7], wherein the thickness of the support is 1 μm or more and 105 μm or less. [9] The support is a copper foil, The resin sheet according to any one of [1] to [8], wherein the arithmetic mean roughness (Ra) of the copper foil surface in contact with the layer containing the resin composition is 0.05 μm or more and 2 μm or less.

[10] The resin sheet according to [9], wherein the copper foil peel strength of the layer containing the resin composition is 0.5 kgf / cm or more.

[0026]

[11] A printed wiring board including a layer containing a cured product of the resin composition according to any one of [1] to

[10] and a conductor layer disposed on the surface of the layer containing the cured product. [Advantages of the Invention]

[0027] According to the present invention, it is possible to sufficiently reduce the warp of a printed wiring board, and cracks are less likely to occur in the insulating layer of the printed wiring board, so that cracks and circuit distortion in the insulating layer are less likely to occur, and it is possible to provide a resin sheet capable of exhibiting excellent heat resistance and high peel strength, and a printed wiring board. [Embodiments for Carrying Out the Invention]

[0028] Hereinafter, embodiments for carrying out the present invention (hereinafter referred to as "the present embodiment") will be described in detail, but the present invention is not limited thereto, and various modifications are possible without departing from the gist thereof.

[0029] As used herein, the "resin solid content" refers to the components in the resin composition according to the present embodiment excluding additives (such as silane coupling agents, wetting dispersants, and curing accelerators), solvents, and fillers (inorganic fillers and organic fillers), unless otherwise specified. The resin solid content of 100 parts by mass means that the total of the components excluding additives (such as silane coupling agents, wetting dispersants, and curing accelerators), solvents, and fillers (inorganic fillers and organic fillers) in the resin composition is 100 parts by mass.

[0030] [Resin Sheet] The resin sheet of the present embodiment (hereinafter also simply referred to as "resin sheet") includes a support and a layer containing a resin composition disposed on the surface of the support. The resin composition contains a cyanate ester compound and / or a phenol compound, and an epoxy compound and / or a maleimide compound. At least one selected from the group consisting of a cyanate ester compound, a phenol compound, an epoxy compound, and a maleimide compound contains a compound having a biphenyl skeleton. When the resin composition contains an inorganic filler, the content of the inorganic filler is 60 parts by mass or less with respect to 100 parts by mass of the resin solid content in the resin composition. The Vickers hardness (HV0.01) of the cured product of the resin composition is 10 or more and 19 or less. The thickness of the layer containing the resin composition is 2 μm or more and 20 μm or less.

[0031] The layer containing the resin composition for the resin sheet is obtained by applying the resin composition in the uncured state (A stage) to a support and then bringing it into a semi-cured state (B stage). As the method for manufacturing the resin sheet, a method for manufacturing a composite of the layer containing the resin composition in the B-stage state and the support is generally preferred. Specifically, in the present embodiment, the resin composition in the uncured state (A stage) is in the form of a varnish, and using a known method such as a bar coater, this varnish is applied to a support such as a copper foil, and then heated in a dryer at 100°C or higher and 200°C or lower for 1 minute or more and 60 minutes or less to semi-cure (B-stage), and a method for manufacturing a resin sheet can be mentioned. For specific manufacturing methods, reference can be made to the examples.

[0032] Here, in the present embodiment, the uncured state (A stage) refers to a state in which the resin composition is not substantially cured and not gelled. The resin composition before being applied to the support for the resin sheet is, for example, a mixture of the constituent components of the resin composition (which may or may not contain a solvent), or a varnish in which the mixture is dissolved or dispersed in a solvent, and is in the uncured state (A stage).

[0033] Further, in the present embodiment, the semi-cured state (B stage) means that each component contained in the layer containing the resin composition has not actively started to react (cure), but the layer containing the resin composition is in a dry state, that is, a state in which the solvent has been volatilized by heating to such an extent that there is no tackiness, and also includes a state in which the solvent has only volatilized without curing even without heating. In the present embodiment, the minimum melt viscosity in the semi-cured state (B stage) is usually 20,000 Pa·s or less. The lower limit of the minimum melt viscosity is, for example, 10 Pa·s or more. In the present embodiment, the minimum melt viscosity is measured by the following method. That is, 1 g of resin powder collected from the layer containing the resin composition is used as a sample, and the minimum melt viscosity is measured with a rheometer (ARES-G2 (trade name) manufactured by TA Instruments). Here, a disposable plate with a plate diameter of 25 mm is used, and in the range of 40°C or higher and 180°C or lower, the minimum melt viscosity of the resin powder is measured under the conditions of a temperature rising rate of 2°C / minute, a frequency of 10.0 rad / second, and a strain of 0.1%.

[0034] In addition, in the present embodiment, the Vickers hardness is a value measured for the cured product in the cured state (C stage) of the resin composition. The cured state (C stage) refers to a state in which the thermosetting resin contained in the resin composition has been fully cured and has become a cured product, and is a state in which further curing does not proceed. The cured product is obtained by thermally curing the resin composition in the uncured state (A stage) or the semi-cured state (B stage) under the conditions of, for example, a heating temperature of 180°C or higher and 270°C or lower, a pressure of 2 kgf / cm 2 or higher and 100 kgf / cm 2 or lower, and a heating time of 30 minutes or longer and 210 minutes or shorter.

[0035] In the present embodiment, by using the resin sheet of the present embodiment, the warp of the printed wiring board can be sufficiently reduced, and cracks are less likely to occur in the insulating layer of the printed wiring board, so that cracks and circuit distortion in the insulating layer are less likely to occur, and excellent heat resistance and high peel strength can be exhibited. The technical reasons are considered as follows. Although the following description includes considerations, the present embodiment is not limited by these considerations.

[0036] In the layer containing the resin composition disposed on the surface of the support in the resin sheet of the present embodiment, the resin composition contains a cyanate ester compound and / or a phenol compound, and an epoxy compound and / or a maleimide compound, and one or more selected from the group consisting of a cyanate ester compound, a phenol compound, an epoxy compound, and a maleimide compound contains a compound having a biphenyl skeleton. When an inorganic filler is included, the content of the inorganic filler is 60 parts by mass or less with respect to 100 parts by mass of the resin solid content in the resin composition. The Vickers hardness (HV0.01) of the cured product (C-stage) of the resin composition is 10 or more and 19 or less, and the thickness of the layer (B-stage) containing the resin composition is 2 μm or more and 20 μm or less. Therefore, the resulting insulating layer (cured product) is a thin film, but has high rigidity due to the biphenyl skeleton, and on the other hand, has appropriate flexibility due to the single bond between phenyl groups, so it has a good balance of rigidity and flexibility. Furthermore, the surface of the insulating layer is considered to have appropriate hardness. Therefore, it is estimated that the insulating layer has resistance to warpage and can relieve external forces such as impact. Furthermore, since the resin composition is composed of specific compounds and contains the inorganic filler in a specific blending amount when included, it is estimated that the resulting insulating layer can also have excellent heat resistance and high peel strength. For these reasons, the inventors of the present invention estimate that by using the resin sheet of the present embodiment, the warpage of the printed wiring board can be sufficiently reduced, cracks are less likely to occur in the insulating layer of the printed wiring board, so that cracks and circuit distortion of the insulating layer are less likely to occur, and excellent heat resistance and high peel strength can be exhibited.

[0037] [Layer containing resin composition] The resin sheet of the present embodiment includes a layer containing a resin composition disposed on the surface of the support described below. The layer containing the resin composition is not particularly limited as long as it contains the resin composition described below. The thickness of the layer containing the resin composition is 2 μm or more and 20 μm or less, preferably 2 μm or more and 15 μm or less, and more preferably 3 μm or more and 15 μm or less.

[0038] (Cured product of resin composition) In the resin sheet of the present embodiment, the Vickers hardness (HV0.01) of the cured product (C stage) when the resin composition is cured is 10 or more and 19 or less. Since it has more appropriate rigidity, it is preferably 11 or more and 19 or less, and more preferably 12 or more and 19 or less.

[0039] Note that the cured product for measuring the Vickers hardness (HV0.01) is obtained by thermosetting the resin composition in a semi-cured state (B stage) under the conditions of a heating temperature of 180°C or higher and 270°C or lower, a pressure of 2 kgf / cm 2 or more and 100 kgf / cm 2 or less, and a heating time of 30 minutes or more and 210 minutes or less. The heating temperature is preferably 200°C or higher and 240°C or lower, more preferably 210°C or higher and 230°C or lower, and still more preferably 220°C. The pressure conditions are preferably 10 kgf / cm 2 or more and 50 kgf / cm 2 or less, more preferably 20 kgf / cm 2 or more and 40 kgf / cm 2 or less, and still more preferably 30 kgf / cm 2 . The heating time is preferably 60 minutes or more and 180 minutes or less, and more preferably 120 minutes. The heating means for curing the resin composition is not particularly limited as long as it does not inhibit the effects of the present embodiment, and ordinary heating means (for example, a dryer, etc.) may be used. The specific measurement method is as described in the examples.

[0040] (Constituent components of the resin composition) (Cyanate ester compound, phenol compound, epoxy compound, and maleimide compound) Since the resin composition according to this embodiment has high heat resistance, it contains a cyanate ester compound and / or a phenol compound, and an epoxy compound and / or a maleimide compound, and at least one selected from the group consisting of a cyanate ester compound, a phenol compound, an epoxy compound, and a maleimide compound contains a compound having a biphenyl skeleton. In this embodiment, the compound having a biphenyl skeleton means that at least one compound selected from the group consisting of a cyanate ester compound, a phenol compound, an epoxy compound, and a maleimide compound has a biphenyl skeleton. Since the resin composition has such a specific configuration, cracks are less likely to occur in the insulating layer of the printed wiring board, and cracks and circuit distortion in the insulating layer are less likely to occur, and excellent heat resistance and high peel strength can be exhibited. These compounds are used singly or in combination of two or more. Among these, from the viewpoint of obtaining good flexibility, the compound preferably contains a phenol compound and an epoxy compound and / or a maleimide compound.

[0041] In this embodiment, the content of the compound having a biphenyl skeleton is preferably 15 parts by mass or more, more preferably 15 parts by mass or more and 90 parts by mass or less, and still more preferably 15 parts by mass or more and 80 parts by mass or less with respect to 100 parts by mass of the resin solid content in the resin composition, because cracks are less likely to occur in the insulating layer of the printed wiring board, cracks and circuit distortion in the insulating layer are less likely to occur, and excellent heat resistance and high peel strength can be more exhibited.

[0042] In this embodiment, if one or more selected from the group consisting of cyanate ester compounds, phenol compounds, epoxy compounds, and maleimide compounds contain compounds having a polycyclic aromatic group, the rigidity increases, and thus the warp of the printed wiring board tends to increase. Cracks are likely to occur in the insulating layer of the printed wiring board, so that cracks in the insulating layer and circuit distortion are likely to occur. Therefore, in this embodiment, the content of the compound having a polycyclic aromatic group is preferably less than 40 parts by mass with respect to 100 parts by mass of the resin solid content in the resin composition. From the viewpoint of obtaining more excellent heat resistance, it is more preferably 2 parts by mass or more and less than 40 parts by mass, and even more preferably 3 parts by mass or more and less than 40 parts by mass. In this embodiment, the compound having a polycyclic aromatic group means that one or more compounds selected from the group consisting of cyanate ester compounds, phenol compounds, epoxy compounds, and maleimide compounds have a polycyclic aromatic group. In this embodiment, the polycyclic aromatic group means a condensed ring structure in which two or more unsaturated cyclic compounds such as naphthalene, anthracene, indene, and fluorene supply the sides of their respective rings to each other, excluding structures in which monocyclic aromatic groups such as biphenyl and phenylpyridine are directly bonded by single bonds. Further, in this embodiment, a compound having both a biphenyl skeleton and a polycyclic aromatic group is included in the compound having a polycyclic aromatic group.

[0043] Next, the compounds having a biphenyl skeleton and the compounds having a polycyclic aromatic group will be described in detail together with specific cyanate ester compounds, phenol compounds, epoxy compounds, and maleimide compounds.

[0044] (Cyanate Ester Compound) In this embodiment, the "cyanate ester compound" refers to a compound having two or more cyanato groups (cyanate ester groups) in one molecule, and the "compound" refers to a concept including resins. Examples of the cyanate ester compound include aromatic hydrocarbon compounds containing two or more cyanato groups in one molecule, compounds in which two aromatic rings containing two or more cyanato groups are bonded by a linking group, novolac type cyanate ester compounds, bisphenol type cyanate ester compounds, diallylbisphenol type cyanate ester compounds (for example, diallylbisphenol A type cyanate ester compound, diallylbisphenol E type cyanate ester compound, diallylbisphenol F type cyanate ester compound, and diallylbisphenol S type cyanate ester compound, etc.), aralkyl type cyanate ester compounds, and prepolymers of these cyanate esters. These cyanate ester compounds are used alone or in combination of two or more. Among these, from the viewpoint of obtaining the glass transition temperature of the cured product and further improving the chemical resistance and peel strength, aralkyl type cyanate ester compounds are preferred, and α-naphthol aralkyl type cyanate ester compounds and biphenyl aralkyl type cyanate ester compounds are more preferred.

[0045] Examples of the aromatic hydrocarbon compound containing two or more cyanato groups in one molecule include, for example, formula (I): Ar-(OCN) p(In the formula, Ar represents any one of a benzene ring, a naphthalene ring, and a biphenyl ring, and p represents an integer of 2 or more.) Examples of the compound represented by the formula include compounds having a biphenyl skeleton when Ar in formula (I) contains a biphenyl ring. Further, when Ar in formula (Ia) contains a naphthalene ring, the compound has a polycyclic aromatic group. Examples of the compound represented by the above formula (I) include 1,3-dicyanobenzene, 1,4-dicyanobenzene, 1,3,5-tricyanobenzene, 1,3-dicyanonaphthalene, 1,4-dicyanonaphthalene, 1,6-dicyanonaphthalene, 1,8-dicyanonaphthalene, 2,6-dicyanonaphthalene, 2,7-dicyanonaphthalene, 1,3,6-tricyanonaphthalene, and 4,4'-dicyanobiphenyl.

[0046] Examples of the compound in which two aromatic rings each containing two or more cyanato groups are bonded by a linking group include bis(4-cyanatophenyl) ether, bis(4-cyanatophenyl) thioether, and bis(4-cyanatophenyl) sulfone.

[0047] Examples of the novolak type cyanate ester compound include the compound represented by the following formula (1).

[0048]

Chemical formula

[0049] In the above formula (1), R 1a each independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. R 1b each independently represents a hydrogen atom or a methyl group, preferably a hydrogen atom. n represents an integer of 1 or more and 10 or less, preferably an integer of 1 or more and 7 or less.

[0050] Examples of the compound represented by the above formula (1) include bis(3,5-dimethyl-4-cyanatophenyl)methane, bis(4-cyanatophenyl)methane, and 2,2'-bis(4-cyanatophenyl)propane.

[0051] These cyanate ester compounds are used singly or in combination of two or more. Among these, the cyanate ester compounds are preferably bisphenol type cyanate ester compounds and / or aralkyl type cyanate ester compounds from the viewpoint of obtaining heat resistance of the resulting cured product and further excellent low water absorption.

[0052] (Bisphenol type cyanate ester compound) The bisphenol type cyanate ester compound is not particularly limited, and examples thereof include bisphenol A type cyanate ester compound, bisphenol E type cyanate ester compound, bisphenol F type cyanate ester compound, and bisphenol S type cyanate ester compound.

[0053] As the bisphenol type cyanate ester compound, commercially available products may be used, or prepared products prepared by known methods may be used. Examples of commercially available products of bisphenol type cyanate ester compounds include CA210 (trade name) manufactured by Mitsubishi Gas Chemical Company, Inc.

[0054] (Aralkyl type cyanate ester compound) The aralkyl type cyanate ester compound is not particularly limited, and examples thereof include α-naphthol aralkyl type cyanate ester compound and biphenyl aralkyl type cyanate ester compound. In this embodiment, the α-naphthol aralkyl type cyanate ester compound is a compound having a polycyclic aromatic group. The biphenyl aralkyl type cyanate ester compound is a compound having a biphenyl skeleton.

[0055] Examples of the α-naphthol aralkyl type cyanate ester compound include a compound represented by the following formula (1a). Since the heat resistance of the resin layer of the printed wiring board is further improved, it is preferable that the resin composition contains an α-naphthol aralkyl type cyanate ester compound.

[0056] [Chemical formula]

[0057] In the above formula (1a), R 1c each independently represents a hydrogen atom or a methyl group, preferably represents a hydrogen atom. n1 represents an integer of 1 or more and 10 or less, preferably represents an integer of 1 or more and 6 or less.

[0058] Examples of the biphenyl aralkyl type cyanate ester compound include compounds represented by the following formula (1b).

[0059] [Chemical formula]

[0060] In the above formula (1b), R 1d each independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. R 1e each independently represents a hydrogen atom or a methyl group, preferably represents a hydrogen atom. n2 represents an integer of 1 or more and 10 or less, preferably represents an integer of 1 or more and 6 or less.

[0061] As for the aralkyl type cyanate ester compound, commercially available products may be used, or products synthesized by known methods may be used. Examples of the synthesis method of the aralkyl type cyanate ester compound include a method of reacting a phenol resin corresponding to the target aralkyl type cyanate ester compound (hereinafter, also referred to as "corresponding phenol resin"), cyanogen halide, and a basic compound in an inert organic solvent, and a method of reacting a salt formed by reacting the corresponding phenol resin and a basic compound in an aqueous solution with cyanogen halide in a two-phase interfacial reaction, etc. In any method, an aralkyl type cyanate ester compound can be obtained by cyanating the hydrogen atom of the phenolic hydroxyl group of the corresponding phenol resin. More specifically, for example, the method described in the examples is used.

[0062] The content of the cyanate ester compound is preferably 10 parts by mass or more and 45 parts by mass or less with respect to 100 parts by mass of the resin solid content. When the content is within the above range, cracks are less likely to occur in the insulating layer of the printed wiring board, so that cracks and circuit distortion in the insulating layer are less likely to occur, and excellent heat resistance and high peel strength tend to be more exhibited. From the same viewpoint, the lower limit value of the content is more preferably 15 parts by mass, still more preferably 20 parts by mass, and even more preferably 30 parts by mass. The upper limit value of the content is more preferably 40 parts by mass, still more preferably 35 parts by mass.

[0063] The cyanate equivalent of the cyanate ester compound is preferably 100 g / eq or more and 500 g / eq or less, more preferably 100 g / eq or more and 400 g / eq or less, and still more preferably 100 g / eq or more and 300 g / eq or less. When the cyanate equivalent is within the above range, the rigidity of the obtained cured product is further improved, and the glass transition temperature and the warp of the printed wiring board tend to be further suppressed.

[0064] (Phenol compound) In this embodiment, the "phenolic compound" refers to a compound having two or more phenolic hydroxyl groups in one molecule, and the "compound" refers to a concept including resins. Examples of the phenolic compound include phenols having two or more phenolic hydroxyl groups in one molecule, bisphenols (e.g., bisphenol A, bisphenol E, bisphenol F, bisphenol S, etc.), diallylbisphenols (e.g., diallylbisphenol A, diallylbisphenol E, diallylbisphenol F, diallylbisphenol S, etc.), bisphenol-type phenolic resins (e.g., bisphenol A-type resin, bisphenol E-type resin, bisphenol F-type resin, bisphenol S-type resin, etc.), phenolic novolak resins (e.g., phenol novolak resin, naphthol novolak resin, cresol novolak resin, etc.), glycidyl ester-type phenolic resins, naphthalene-type phenolic resins, anthracene-type phenolic resins, dicyclopentadiene-type phenolic resins, biphenyl-type phenolic resins, alicyclic phenolic resins, polyol-type phenolic resins, aralkyl-type phenolic resins, and phenol-modified aromatic hydrocarbon formaldehyde resins, etc. These phenolic compounds are used alone or in combination of two or more. In this embodiment, when the phenolic compound includes a compound having a biphenyl skeleton, examples of such a compound include biphenyl-type phenolic resins. When the phenolic compound includes a compound having a polycyclic aromatic group, examples of such a compound include naphthol novolak resins, cresol novolak resins, naphthalene-type phenolic resins, and anthracene-type phenolic resins. Among these, from the viewpoint of further excellent heat resistance and low water absorption of the obtained cured product, the phenolic compound is preferably an aralkyl-type phenolic resin and / or a phenol-modified aromatic hydrocarbon formaldehyde resin, and more preferably a biphenylaralkyl-type phenolic resin and / or a phenol-modified xylene resin.

[0065] (Aralkyl-type phenolic resin) Examples of the aralkyl type phenol resin include compounds represented by the following formula (2a).

[0066] [Chemical formula]

[0067] In the above formula (2a), Ar 1 each independently represents a benzene ring or a naphthalene ring. Ar 2 represents a benzene ring, a naphthalene ring, or a biphenyl ring. R 2a each independently represents a hydrogen atom or a methyl group. m represents an integer of 1 or more and 50 or less. Each ring may have a substituent other than a hydroxyl group (for example, an alkyl group having 1 to 5 carbon atoms or a phenyl group, etc.). When Ar 2 in the formula (2a) contains a biphenyl ring, it becomes a compound having a biphenyl skeleton. Also, when Ar 1 and / or Ar 2 in the formula (2a) contains a naphthalene ring, it becomes a compound having a polycyclic aromatic. When the formula (2a) contains a naphthalene ring and a biphenyl ring, it becomes a compound having a polycyclic aromatic.

[0068] Examples of the compound represented by the above formula (2a) include, for example, in the above formula (2a), a compound in which Ar 1 is a naphthalene ring and Ar 2 is a benzene ring (also referred to as "naphthol aralkyl type phenol resin"), and in the above (2a), a compound in which Ar 1 is a benzene ring and Ar 2 is a biphenyl ring (also referred to as "biphenyl aralkyl type phenol resin"). From the viewpoint of further excellent heat resistance and low water absorption of the obtained cured product, biphenyl aralkyl type phenol resin is preferable as the compound represented by the formula (2a).

[0069] The naphthol aralkyl type phenol resin is preferably a compound represented by the following formula (2b).

[0070] [Chemical formula]

[0071] In the above formula (2b), R 2a is the same as R 2a in the above formula (2a), and is preferably a hydrogen atom. m is the same as m in the above formula (2a), preferably an integer of 1 or more and 10 or less, and more preferably an integer of 1 or more and 6 or less.

[0072] The biphenyl aralkyl type phenol resin is preferably a compound represented by the following formula (2c). Since the warp of the printed wiring board can be further reduced, the generation of cracks is less likely to occur, and a resin layer having a more appropriate hardness can be obtained, the resin composition preferably contains a biphenyl aralkyl type phenol resin.

[0073] [Chemical formula]

[0074] In the above formula (2c), each R 2b independently represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a phenyl group, and preferably represents a hydrogen atom. m1 represents an integer of 1 or more and 20 or less, and preferably represents an integer of 1 or more and 6 or less.

[0075] As the aralkyl type phenol resin, commercially available products may be used, or products synthesized by known methods may be used. Examples of commercially available aralkyl type phenol resins include SN-495 (trade name) manufactured by Nippon Steel Chemical Co., Ltd. (naphthol aralkyl type phenol resin represented by formula (2b)), and KAYAHARD® GPH-65 (trade name), KAYAHARD® GPH-78 (trade name), and KAYAHARD® GPH-103 (trade name) manufactured by Nippon Kayaku Co., Ltd. (all biphenyl aralkyl type phenol resins represented by formula (2c)).

[0076] (Phenol-modified aromatic hydrocarbon formaldehyde resin) As used herein, the “phenol-modified aromatic hydrocarbon formaldehyde resin” refers to a resin obtained by heating an aromatic hydrocarbon formaldehyde resin and phenols in the presence of an acidic catalyst (for example, para-toluenesulfonic acid, oxalic acid, etc.) to cause a condensation reaction (modified condensation reaction).

[0077] The aromatic hydrocarbon formaldehyde resin is not particularly limited. For example, compounds obtained by subjecting an aromatic hydrocarbon compound (for example, toluene, ethylbenzene, xylene, mesitylene, pseudocumene, a monocyclic aromatic hydrocarbon compound having 10 or more carbon atoms, and a polycyclic aromatic hydrocarbon compound such as methylnaphthalene, etc.) and formaldehyde to a condensation reaction can be mentioned. Among these, a xylene formaldehyde resin obtained by subjecting xylene and formaldehyde to a condensation reaction is preferably used.

[0078] Phenols are not particularly limited. For example, phenol, cresols, bisphenol propane, bisphenol methane, resorcinol, pyrocatechol, hydroquinone, para-tertiary butylphenol, bisphenol sulfone, bisphenol ether, para-phenylphenol, etc. can be mentioned. These phenols can be used alone or in combination of two or more.

[0079] The phenol-modified aromatic hydrocarbon formaldehyde resin is preferably a phenol-modified xylene formaldehyde resin obtained by heating a xylene formaldehyde resin and the above-mentioned phenols in the presence of the above-mentioned acidic catalyst to cause a condensation reaction, and more preferably a phenol-modified xylene resin.

[0080] The phenol-modified aromatic hydrocarbon formaldehyde resin may be a commercially available product or a product prepared by a known method. Examples of commercially available phenol-modified aromatic hydrocarbon formaldehyde resins include HP-120 (trade name), HP-100 (trade name), HP-210 (trade name), HP-70 (trade name), NP-100 (trade name), GP-212 (trade name), P-100 (trade name), GP-100 (trade name), GP-200 (trade name), HP-30 (trade name), etc., which are the Zister (registered trademark) series manufactured by Fudo Co., Ltd. Examples of known methods include the method described in JP-A-2015-174874.

[0081] The content of the phenol compound is not particularly limited, but is preferably 10 parts by mass or more and 60 parts by mass or less with respect to 100 parts by mass of the resin solid content. When the content is within the above range, cracks are less likely to occur in the insulating layer of the printed wiring board, so that cracks and circuit distortion in the insulating layer are less likely to occur, and excellent heat resistance and high peel strength tend to be more exhibited. From the same viewpoint, the lower limit of the content is more preferably 20 parts by mass, still more preferably 30 parts by mass, the upper limit value of the content is more preferably 55 parts by mass, still more preferably 50 parts by mass, and even more preferably 40 parts by mass.

[0082] The phenol equivalent (hydroxyl equivalent of phenolic hydroxyl groups) of the phenol compound is preferably 500 g / eq or less, more preferably 400 g / eq or less, still more preferably 350 g / eq or less, and even more preferably 300 g / eq or less. When the phenol equivalent is within the above range, the rigidity of the obtained cured product is further excellent, and the glass transition temperature and the warp of the printed wiring board tend to be further suppressed. The lower limit is not particularly limited, but is 100 g / eq or more.

[0083] (Epoxy compound) In this embodiment, the "epoxy compound" refers to a compound having two or more epoxy groups in one molecule, and the "compound" refers to a concept including resins. Examples of the epoxy compound include bisphenol type epoxy resins (for example, bisphenol A type epoxy resin, bisphenol E type epoxy resin, bisphenol F type epoxy resin, and bisphenol S type epoxy resin), diallylbisphenol type epoxy resins (for example, diallylbisphenol A type epoxy resin, diallylbisphenol E type epoxy resin, diallylbisphenol F type epoxy resin, and diallylbisphenol S type epoxy resin, etc.), phenol novolac type epoxy resins (for example, phenol novolac type epoxy resin, bisphenol A novolac type epoxy resin, and cresol novolac type epoxy resin), aralkyl type epoxy resins, biphenyl type epoxy resins containing a biphenyl skeleton, naphthalene type epoxy resins containing a naphthalene skeleton, anthracene type epoxy resins containing an anthracene skeleton, glycidyl ester type epoxy resins, polyol type epoxy resins, isocyanurate ring-containing epoxy resins, dicyclopentadiene type epoxy resins, epoxy resins composed of bisphenol A type structural units and hydrocarbon-based structural units, and halogen compounds thereof. These epoxy compounds are used alone or in combination of two or more. In this embodiment, when the epoxy resin contains a compound having a biphenyl skeleton, examples of such a compound include biphenyl type epoxy resins. When the epoxy resin contains a compound having a polycyclic aromatic group, examples of such a compound include naphthalene type epoxy resins containing a naphthalene skeleton and anthracene type epoxy resins containing an anthracene skeleton. Among these, from the viewpoint of further excellent heat resistance and low water absorption of the obtained cured product, it is preferably one or more selected from the group consisting of aralkyl type epoxy resins, naphthalene type epoxy resins, dicyclopentadiene type epoxy resins, and epoxy resins composed of bisphenol A type structural units and hydrocarbon-based structural units.In this embodiment, since cracks are less likely to occur in the insulating layer of the printed wiring board, cracks and circuit distortion in the insulating layer are less likely to occur, and excellent heat resistance and high peel strength can be more effectively exhibited. Therefore, it contains two or more types of epoxy compounds, and it is preferable that the two or more types of epoxy compounds contain a naphthalene-type epoxy resin containing a naphthalene skeleton and / or an aralkyl-type epoxy resin, and it is more preferable to contain a naphthalene-type epoxy resin and an aralkyl-type epoxy resin. As the aralkyl-type epoxy resin, a biphenyl aralkyl-type epoxy resin is more preferable.

[0084] (Aralkyl-type epoxy resin) Examples of the aralkyl-type epoxy resin include compounds represented by the following formula (3a).

[0085]

Chemical formula

[0086] In the above formula (3a), Ar 3 each independently represents a benzene ring or a naphthalene ring. Ar 4 represents a benzene ring, a naphthalene ring, or a biphenyl ring. R 3a each independently represents a hydrogen atom or a methyl group. k represents an integer of 1 or more and 50 or less. Each ring may have a substituent other than a glycidyloxy group (for example, an alkyl group having 1 to 5 carbon atoms or a phenyl group). When Ar 4 in formula (3a) contains a biphenyl ring, it becomes a compound having a biphenyl skeleton. Also, when Ar 3 and / or Ar 4 in formula (3a) contains a naphthalene ring, it becomes a compound having a polycyclic aromatic group. When the naphthalene ring and the biphenyl ring in formula (3a) are included, it becomes a compound having a polycyclic aromatic group.

[0087] From the viewpoint of further excellent heat resistance and low water absorption of the obtained cured product, in the above formula (3a), Ar 3 is a naphthalene ring, and Ar 4is a compound having a benzene ring (also referred to as a "naphthalene aralkyl type epoxy resin"), and Ar 3 is a benzene ring, and Ar 4 is preferably a compound having a biphenyl ring (also referred to as a "biphenyl aralkyl type epoxy resin"), and more preferably a biphenyl aralkyl type epoxy resin.

[0088] The aralkyl type epoxy resin may be a commercially available product or a product prepared by a known method. Examples of commercially available naphthalene aralkyl type epoxy resins include Epotope (registered trademark) ESN-155 (trade name), Epotope (registered trademark) ESN-355 (trade name), Epotope (registered trademark) ESN-375 (trade name), Epotope (registered trademark) ESN-475V (trade name), Epotope (registered trademark) ESN-485 (trade name), and Epotope (registered trademark) ESN-175 (trade name) manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.; NC-7000 (trade name), NC-7300 (trade name), and NC-7300L (trade name) manufactured by Nippon Kayaku Co., Ltd.; HP-5000 (trade name), HP-9900 (trade name), HP-9540 (trade name), and HP-9500 (trade name) manufactured by DIC Corporation, etc. Examples of commercially available biphenyl aralkyl type epoxy resins include NC-3000 (trade name), NC-3000L (trade name), and NC-3000FH (trade name) manufactured by Nippon Kayaku Co., Ltd., etc.

[0089] The biphenyl aralkyl type epoxy resin is preferably a compound represented by the following formula (3b) from the viewpoint of further excellent heat resistance and low water absorption of the obtained cured product.

[0090]

Chemical formula

[0091] In the above formula (3b), ka represents an integer of 1 or more, preferably an integer of 1 or more and 20 or less, and more preferably an integer of 1 or more and 6 or less.

[0092] Moreover, it is also preferable that the naphthalene aralkyl type epoxy resin is a compound represented by the following formula (3c). Since the warp of the printed wiring board can be further reduced, the generation of cracks is less likely to occur, and a resin layer having more appropriate hardness can be obtained, it is preferable that the resin composition contains a naphthalene aralkyl type epoxy resin.

[0093]

Chemical formula

[0094] In the above formula (3c), ky represents an integer of 1 or more and 10 or less. Also, Me represents a methyl group.

[0095] (Naphthalene type epoxy resin) Examples of the naphthalene type epoxy resin include epoxy resins excluding the above naphthalene aralkyl type epoxy resin, a naphthalene skeleton-containing polyfunctional epoxy resin having a naphthalene skeleton represented by the following formula (3d), and an epoxy resin having a naphthalene skeleton (for example, an epoxy resin represented by the following formula (3e)). These resins are compounds having a polycyclic aromatic group. Examples of the naphthalene type epoxy resin include naphthylene ether type epoxy resins. The naphthylene ether type epoxy resin is preferable because the cured product obtained has more excellent heat resistance and low water absorption.

[0096]

Chemical formula

[0097] In the above formula (3d), Ar 31 each independently represents a benzene ring or a naphthalene ring. Ar 41 represents a benzene ring, a naphthalene ring, or a biphenyl ring. R 31aEach independently represents a hydrogen atom or a methyl group. p represents an integer of 0 or more and 2 or less, preferably represents 0 or 1. kz represents an integer of 1 or more and 50 or less. Each ring may have a substituent other than a glycidyloxy group (for example, an alkyl group having 1 to 5 carbon atoms, an alkoxy group, or a phenyl group), Ar 31 and Ar 41 at least one of which represents a naphthalene ring. Ar in formula (3d) 31 and / or Ar 41 When including a naphthalene ring, it becomes a compound having a polycyclic aromatic. Ar in formula (3d) 31 When containing a benzene ring and Ar 41 When containing a biphenyl ring, it becomes a compound having a biphenyl skeleton. When containing a naphthalene ring and a biphenyl ring in formula (3d), it becomes a compound having a polycyclic aromatic.

[0098] Examples of the compound represented by the above formula (3d) include the compound represented by the following formula (3f).

[0099]

Chemical formula

[0100] In the above formula (3f), kz has the same meaning as kz in the above formula (3d).

[0101] As the naphthalene skeleton-containing polyfunctional epoxy resin, commercially available products may be used, or prepared products prepared by known methods may also be used. Examples of commercially available naphthalene skeleton-containing polyfunctional epoxy resins include HP-9540 (trade name) and HP-9500 (trade name) manufactured by DIC Corporation, etc.

[0102]

Chemical formula

[0103] As for the epoxy resin represented by the above formula (3e), a commercially available product may be used, or a product prepared by a known method may be used. Examples of commercially available products include HP-4710 (trade name) manufactured by DIC Corporation, etc.

[0104] (Naphthylene ether type epoxy resin) Examples of the naphthylene ether type epoxy resin include, for example, a compound represented by the following formula (3g). Since a resin layer having more appropriate hardness can be obtained, it is preferable that the resin composition contains a naphthylene ether type epoxy resin.

[0105] [Chemical formula]

[0106] In the above formula (3g), R 3b each independently represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an aralkyl group, a naphthyl group, or a naphthyl group containing a glycidyloxy group. k1 represents an integer of 1 or more and 10 or less.

[0107] In the compound represented by the above formula (3g), the number of glycidyloxy groups containing an epoxy group in the molecule is preferably 2 or more and 6 or less, and more preferably 2 or more and 4 or less.

[0108] In the above formula (3g), k1 represents an integer of 0 or more and 10 or less. From the viewpoint of more effectively and surely achieving the effects of the present embodiment, it preferably represents an integer of 0 or more and 6 or less, more preferably represents an integer of 0 or more and 4 or less, and even more preferably is 2 or 3.

[0109] In the above formula (3g), R 3b each independently preferably represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an aralkyl group, and a naphthyl group from the viewpoint of more effectively and surely achieving the effects of the present embodiment.

[0110] In addition, when the naphthalene ether type epoxy resin contains the compound represented by the above formula (3g), it may contain a plurality of types of compounds having the same k1, or may contain a plurality of types of compounds having different k1. When the naphthalene ether type epoxy resin contains a plurality of types of compounds having different k1, in the above formula (3g), it preferably contains a compound in which k1 is an integer of 0 or more and 4 or less, and more preferably contains a compound in which k1 is 2 or 3.

[0111] Examples of the compound represented by the above formula (3g) include a compound represented by the following formula (3h).

[0112] [Chemical formula]

[0113] As the epoxy resin represented by the above formula (3h), a commercially available product may be used, or a prepared product prepared by a known method may be used. Examples of commercially available products include HP-4032 (trade name) manufactured by DIC Corporation.

[0114] As the naphthalene ether type epoxy resin, a commercially available product may be used, or a prepared product prepared by a known method may be used. Examples of commercially available products of the naphthalene ether type epoxy resin include HP-4032 (trade name), HP-6000 (trade name), EXA-7300 (trade name), EXA-7310 (trade name), EXA-7311 (trade name), EXA-7311L (trade name), and EXA7311-G3 (trade name) manufactured by DIC Corporation.

[0115] (Dicyclopentadiene type epoxy resin) Examples of the dicyclopentadiene type epoxy resin include a compound represented by the following formula (3i). Since a resin layer having more appropriate hardness can be obtained, it is preferable that the resin composition contains a dicyclopentadiene type epoxy resin.

[0116] [Chemical formula]

[0117] In the above formula (3i), R 3c each independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. k2 represents an integer of 0 or more and 10 or less.

[0118] In the above formula (3i), k2 represents an integer of 0 or more and 10 or less. From the viewpoint of more effectively and surely achieving the effects of the present embodiment, it preferably represents an integer of 0 or more and 6 or less, more preferably represents an integer of 0 or more and 2 or less, and still more preferably is 0 or 1.

[0119] In addition, when the dicyclopentadiene type epoxy resin contains the compound represented by the above formula (3i), it may contain a plurality of types of compounds having the same k2, or may contain a plurality of types of compounds having different k2. When the dicyclopentadiene type epoxy resin contains a plurality of types of compounds having different k2, it preferably contains a compound in which k2 is 0 or more and 2 or less in the above formula (3i).

[0120] As the dicyclopentadiene type epoxy resin, a commercially available product may be used, or a prepared product prepared by a known method may be used. Examples of commercially available products of the dicyclopentadiene type epoxy resin include EPICRON (registered trademark) HP-7200L (trade name), EPICRON (registered trademark) HP-7200 (trade name), EPICRON (registered trademark) HP-7200H (trade name), and EPICRON (registered trademark) HP-7000HH (trade name) manufactured by DIC Corporation.

[0121] (Epoxy resin composed of bisphenol A type structural unit and hydrocarbon type structural unit) An epoxy resin composed of a bisphenol A type structural unit and a hydrocarbon type structural unit (also referred to as a "specific epoxy resin") has one or more bisphenol A type structural units and one or more hydrocarbon type structural units in the molecule. Examples of the above specific epoxy resin include compounds represented by the following formula (3j). Since the generation of cracks is less likely to occur and a resin layer having a more appropriate hardness can be obtained, it is preferable that the resin composition contains a specific epoxy resin.

[0122]

Chemical formula

[0123] In the above formula (3j), R 1x and R 2x each independently represents a hydrogen atom or a methyl group. R 3x to R 6x each independently represents a hydrogen atom, a methyl group, a chlorine atom, or a bromine atom. X represents an ethyleneoxyethyl group, a di(ethyleneoxy)ethyl group, a tri(ethyleneoxy)ethyl group, a propyleneoxypropyl group, a di(propyleneoxy)propyl group, a tri(propyleneoxy)propyl group, or an alkylene group having 2 to 15 carbon atoms.

[0124] In the above formula (3j), k3 represents an integer, and from the viewpoint of more effectively and surely achieving the operation and effect of this embodiment, it is preferably an integer of 1 or more and 10 or less, more preferably an integer of 1 or more and 6 or less, still more preferably 1 or 2, and even more preferably 1.

[0125] In the above formula (3j), from the viewpoint of more effectively and surely achieving the operation and effect of this embodiment, X is preferably an ethylene group.

[0126] For the specific epoxy resin, commercially available products may be used, or prepared products prepared by known methods may also be used. Examples of commercially available products of the specific epoxy resin include EPICLON (registered trademark) EXA-4850-150 (trade name) and EPICLON (registered trademark) EXA-4816 (trade name) manufactured by DIC Corporation, etc.

[0127] The content of the epoxy compound is preferably 10 parts by mass or more and 80 parts by mass or less with respect to 100 parts by mass of the resin solid content. When the content is within the above range, cracks are less likely to occur in the insulating layer of the printed wiring board, so that cracks and circuit distortion in the insulating layer are less likely to occur, and excellent heat resistance and high peel strength tend to be more exhibited. Further, when the content is within the above range, the rigidity, heat resistance, and low water absorption of the obtained cured product tend to be further improved. From the same viewpoint, the lower limit of the content is more preferably 20 parts by mass, still more preferably 25 parts by mass, even more preferably 30 parts by mass, particularly preferably 45 parts by mass, and the upper limit of the content is more preferably 75 parts by mass, still more preferably 70 parts by mass, even more preferably 64 parts by mass.

[0128] The epoxy equivalent of the epoxy compound is preferably 500 g / eq or less, more preferably 400 g / eq or less, and still more preferably 350 g / eq or less. When the epoxy equivalent is within the above range, the rigidity of the obtained cured product is further excellent, and the glass transition temperature and the warp of the printed wiring board tend to be further suppressed. The lower limit is preferably 100 g / eq or more.

[0129] When the resin composition contains a phenol compound and / or a cyanate ester compound and an epoxy compound, the ratio of the amount of phenol groups (parts by mass contained / phenol equivalent) and / or the amount of cyanate ester groups (parts by mass contained / cyanate ester equivalent) in the resin composition to the amount of epoxy groups (parts by mass contained / epoxy equivalent) in the resin composition is preferably 0.5 or more and 1.5 or less. When the resin composition contains both a phenol compound and a cyanate ester compound, the above ratio is the ratio of the total amount of the above phenol groups and the above cyanate groups to the above amount of epoxy groups. When the ratio is within the above range, cracks are less likely to occur in the insulating layer of the printed wiring board, so that cracks and circuit distortion in the insulating layer are less likely to occur, and excellent heat resistance and high peel strength tend to be more exhibited. From the same viewpoint, the lower limit value of the ratio is preferably 0.5, more preferably 0.6, still more preferably 0.7, and even more preferably 0.9. The upper limit value of the ratio is preferably 1.5, more preferably 1.4, still more preferably 1.3, and even more preferably 1.2. When there are a plurality of types of phenol compounds, the above amount of phenol groups means the total value of the amounts of phenol groups of each phenol compound. When there are a plurality of types of cyanate ester compounds, the above amount of cyanate groups means the total value of the amounts of cyanate groups of each cyanate ester compound. When there are a plurality of types of epoxy compounds, the above amount of epoxy groups means the total value of the amounts of epoxy groups of each epoxy compound.

[0130] (Maleimide compound) In the present embodiment, the “maleimide compound” refers to a compound having one or more maleimide groups in one molecule, and the “compound” refers to a concept including a resin. Examples of the maleimide compound include a monomer maleimide compound having one maleimide group in one molecule, a polymaleimide compound having two or more maleimide groups in one molecule, and prepolymers of these maleimide compounds and amine compounds. These maleimide compounds are used alone or in combination of two or more.

[0131] Examples of the monomer maleimide compounds include N-phenylmaleimide and N-hydroxyphenylmaleimide.

[0132] Examples of the polymer maleimide compounds include the compound represented by the following formula (4a); compounds in which maleimide groups are bonded to both ends of a linear or branched alkyl chain such as 2,2-bis(4-(4-maleimidophenoxy)phenyl)propane and 1,6-bismaleimide-(2,2,4-trimethyl)hexane (however, compounds other than the compound represented by the following formula (4a)); bis(4-maleimidophenoxy)biphenyl; bisphenol A diphenyl ether bismaleimide; imide resins in which maleimide groups are directly introduced into a naphthalene ring; phenylene bismaleimides such as m-phenylene bismaleimide and 4-methyl-1,3-phenylene bismaleimide; and compounds in which a plurality of maleimide groups are bonded to a benzene ring.

[0133] [Chemical formula]

[0134] In the above formula (4a), R 4a and R 5a each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, preferably a hydrogen atom. R 4b each independently represents a hydrogen atom or a methyl group, preferably a hydrogen atom. s represents an integer of 1 or more. The lower limit of s is preferably an integer of 10 or less, more preferably an integer of 7 or less.

[0135] Examples of the compound represented by the above formula (4a) include bis(4-maleimidophenyl)methane, bis(3,5-dimethyl-4-maleimidophenyl)methane, bis(3,5-diethyl-4-maleimidophenyl)methane, bis(3-ethyl-5-methyl-4-maleimidophenyl)methane, and polyphenylmethane maleimide compounds. By including the maleimide compound containing the maleimide compound represented by the above formula (4a), the coefficient of thermal expansion of the resulting cured product tends to be further reduced, and the heat resistance and glass transition temperature (Tg) tend to be further improved.

[0136] In the present embodiment, when the maleimide compound contains a compound having a biphenyl skeleton, examples of such a compound include bis(4-maleimidophenoxy)biphenyl. When the maleimide compound contains a compound having a polycyclic aromatic group, examples of such a compound include an imide resin in which a maleimide group is directly introduced into a naphthalene ring. Among these, the maleimide compound is preferably a polymaleimide compound in terms of further improving the heat resistance and glass transition temperature of the resulting cured product. In addition to excellent heat resistance and glass transition temperature, it is more preferably a compound represented by the formula (4a) in terms of further reducing the coefficient of thermal expansion of the resulting cured product, and bis(3-ethyl-5-methyl-4-maleimidophenyl)methane is even more preferred.

[0137] As the maleimide compound, a commercially available product may be used, or a prepared product prepared by a known method may be used. Examples of commercially available maleimide compounds include BMI-70 (trade name) and BMI-80 (trade name) manufactured by Kayaku Kasei Co., Ltd., and BMI-2300 (trade name), BMI-1000P (trade name), BMI-3000 (trade name), BMI-4000 (trade name), BMI-5100 (trade name), and BMI-7000 (trade name) manufactured by Daiwa Kasei Kogyo Co., Ltd.

[0138] The content of the maleimide compound is not particularly limited, but is preferably 1 part by mass or more and 45 parts by mass or less with respect to 100 parts by mass of the resin solid content. When the content is within the above range, the resulting cured product is further excellent in low water absorption, and the warp of the printed wiring board tends to be further suppressed. From the same viewpoint, the lower limit value of the content is more preferably 4 parts by mass, still more preferably 10 parts by mass, even more preferably 15 parts by mass, and the upper limit value of the content is more preferably 40 parts by mass, still more preferably 30 parts by mass, even more preferably 25 parts by mass, and particularly preferably 20 parts by mass.

[0139] (Other resins) The resin composition according to this embodiment may contain other resins, although not particularly limited. Examples of other resins include alkenyl-substituted nadimide compounds, oxetane resins, benzoxazine compounds, and compounds having polymerizable unsaturated groups. These resins may be used alone or in combination of two or more.

[0140] (Alkenyl-substituted nadimide compound) In this embodiment, the "alkenyl-substituted nadimide compound" refers to a compound having one or more alkenyl-substituted nadimide groups in the molecule. Examples of the alkenyl-substituted nadimide compound include compounds represented by the following formula (5a).

[0141]

Chemical formula

[0142] In the above formula (5a), R 6a each independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. R 6b represents an alkylene group having 1 to 6 carbon atoms, a phenylene group, a biphenylene group, a naphthylene group, or a group represented by the following formula (5b) or (5c).

[0143]

Chemical formula

[0144] In the above formula (5b), R 6c represents a methylene group, an isopropylidene group, or a divalent substituent represented by CO, O, S, or SO2.

[0145]

Chemical formula

[0146] In the above formula (5c), R 6d each independently represents an alkylene group having 1 to 4 carbon atoms or a cycloalkylene group having 5 to 8 carbon atoms.

[0147] In addition, the alkenyl-substituted nadimide compound may also include a compound represented by the following formula (6) and / or (7).

[0148]

Chemical formula

[0149]

Chemical formula

[0150] As the alkenyl-substituted nadimide compound, a commercially available product may be used, or a product prepared by a known method may be used. Examples of commercially available alkenyl-substituted nadimide compounds include BANI-M (trade name) and BANI-X (trade name) manufactured by Maruzen Petrochemical Co., Ltd. These alkenyl-substituted nadimide compounds are used alone or in combination of two or more.

[0151] (Oxetane resin) Examples of oxetane resins include alkyl oxetanes such as oxetane, 2-methyloxetane, 2,2-dimethyloxetane, 3-methyloxetane, and 3,3-dimethyloxetane, 3-methyl-3-methoxymethyloxetane, 3,3'-di(trifluoromethyl)perfluorooxetane, 2-chloromethyloxetane, 3,3-bis(chloromethyl)oxetane, biphenyl-type oxetane, and OXT-101 (trade name) and OXT-121 (trade name) manufactured by Toagosei Co., Ltd. These oxetane resins may be used alone or in combination of two or more.

[0152] (Benzoxazine compounds) The term "benzoxazine compound" in this embodiment refers to a compound having two or more dihydrobenzoxazine rings in one molecule. Examples of the benzoxazine compound include bisphenol F-type benzoxazine BF-BXZ (trade name) and bisphenol S-type benzoxazine BS-BXZ (trade name) manufactured by Konishi Chemical Co., Ltd. These benzoxazine compounds may be used alone or in combination of two or more.

[0153] (Compound having a polymerizable unsaturated group) Examples of compounds having a polymerizable unsaturated group include vinyl compounds such as ethylene, propylene, styrene, divinylbenzene, and divinylbiphenyl; (meth)acrylates of monohydric or polyhydric alcohols such as methyl(meth)acrylate, 2-hydroxyethyl(meth)acrylate, 2-hydroxypropyl(meth)acrylate, polypropylene glycol di(meth)acrylate, trimethylolpropane di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, and dipentaerythritol hexa(meth)acrylate; epoxy (meth)acrylates such as bisphenol A type epoxy (meth)acrylate and bisphenol F type epoxy (meth)acrylate; and benzocyclobutene resins. These compounds having polymerizable unsaturated groups are used singly or in combination of two or more thereof.

[0154] These other resins are not particularly limited as long as they exhibit the effects of the present embodiment, but are preferably 1 part by mass or more and 30 parts by mass or less, respectively, based on 100 parts by mass of the resin solid content.

[0155] (Elastomer component) The resin composition according to the present embodiment may contain an elastomer component, although not particularly limited. When the elastomer component is contained in the resin composition, the warp of the printed wiring board tends to be further suppressed. Examples of the elastomer component include acrylic rubber, silicone rubber, acrylonitrile-butadiene rubber, styrene-butadiene rubber, butadiene rubber, polyisoprene rubber, urethane rubber, butyl rubber, and core-shell rubber, which are different from the organic fillers and other additives described later. These elastomer components are used singly or in combination of two or more thereof.

[0156] Examples of the acrylic rubber include alkyl acrylates such as ethyl acrylate and butyl acrylate. Examples of the silicone rubber include copolymers containing dimethylsiloxane groups, methylvinyl groups, methylphenyl groups, and diphenylsiloxane groups, and polydimethylsiloxane composed only of dimethylsiloxane groups. Examples of the core-shell rubber include methacrylate / styrene / butadiene rubber graft copolymers, acrylonitrile / styrene / butadiene rubber graft copolymers, acrylonitrile / styrene / ethylene / propylene rubber graft copolymers, acrylonitrile / styrene / acrylic ester graft copolymers, methacrylate / acrylic ester rubber graft copolymers, and methacrylate / acrylonitrile / acrylic ester rubber graft copolymers.

[0157] The content of the elastomer is usually 30 parts by mass or less, preferably 25 parts by mass or less, more preferably 20 parts by mass or less, still more preferably 15 parts by mass or less, and even more preferably 10 parts by mass or less, based on 100 parts by mass of the resin solid content in the resin composition. When the content is within the above range, the heat resistance and water absorption of the resulting cured product tend to be further improved. The lower limit of the content of the elastomer is 0 parts by mass or more.

[0158] (Filler) In the present embodiment, examples of the filler include inorganic fillers and organic fillers. ·Inorganic filler The resin composition of the present embodiment may contain an inorganic filler, but it is preferable not to contain an inorganic filler because the printed wiring board can be made thinner and smaller, and it has a high peel strength and an appropriate surface hardness. Not containing an inorganic filler means that the content of the inorganic filler is 0 parts by mass based on 100 parts by mass of the resin solid content in the resin composition. In the present embodiment, when the resin composition contains an inorganic filler, the warp of the printed wiring board can be reduced, cracks are less likely to occur in the insulating layer of the printed wiring board, and cracking and circuit distortion of the insulating layer can be less likely to occur. Therefore, the content of the inorganic filler is 60 parts by mass or less, preferably 55 parts by mass or less, and more preferably 45 parts by mass or less, based on 100 parts by mass of the resin solid content in the resin composition. When the inorganic filler is contained, the lower limit is not particularly limited, but it is preferably 1 part by mass or more from the viewpoint of further suppressing the warp of the printed wiring board.

[0159] Examples of inorganic fillers include metal oxides (e.g., silica, alumina, titanium white, zinc oxide, magnesium oxide, and zirconium oxide, etc.); metal nitrides (e.g., boron nitride, aggregated boron nitride, silicon nitride, and aluminum nitride, etc.); metal sulfates (e.g., barium sulfate, etc.); metal hydroxides (e.g., aluminum hydroxide, heat-treated aluminum hydroxide (e.g., heat-treated aluminum hydroxide with a partial reduction of crystal water), boehmite, and magnesium hydroxide, etc.); molybdenum compounds (e.g., molybdenum oxide, and zinc molybdate, etc.); zinc compounds (e.g., zinc borate, and zinc stannate, etc.); clays (e.g., natural clay, and calcined clay); kaolins (e.g., natural kaolin, and calcined kaolin); talcs (e.g., natural talc, and calcined talc); mica; glasses (e.g., E-glass, A-glass, NE-glass, C-glass, L-glass, D-glass, S-glass, M-glass G20, glass short fibers (including glass fine powders such as E-glass, T-glass, D-glass, S-glass, and Q-glass, etc.), hollow glass, and spherical glass), etc. These inorganic fillers are used alone or in combination of two or more kinds.

[0160] Examples of silica include natural silica, fused silica, synthetic silica, amorphous silica, aerosil, hollow silica, and white carbon, etc. Examples of commercially available silica include SC2050-MB (trade name), SC5050-MOB (trade name), SC2500-SQ (trade name), SC4500-SQ (trade name), SC5050-MOB (trade name), SO-C2 (trade name), and SO-C1 (trade name) manufactured by Admatechs Co., Ltd., and SFP-130MC (trade name) manufactured by Denka Co., Ltd., etc.

[0161] · Organic fillers The resin composition of this embodiment may contain an organic filler. However, since it enables the thinning and miniaturization of printed wiring boards, and has high peel strength and appropriate surface hardness, it is preferably free of an organic filler. Being free of an organic filler means that the content of the organic filler is 0 parts by mass with respect to 100 parts by mass of the resin solid content in the resin composition. Examples of the organic filler include rubber powders such as styrene type powder, butadiene type powder, and acrylic type powder; core-shell type rubber powder; silicone type powder, etc. These organic fillers are used alone or in combination of two or more.

[0162] Examples of the silicone type powder include silicone resin powder, silicone rubber powder, and silicone composite powder, etc. These silicone type powders are used alone or in combination of two or more.

[0163] (Silane coupling agent) The resin composition according to this embodiment preferably contains a silane coupling agent. In this embodiment, by containing a silane coupling agent, the adhesive strength between the components of the resin composition according to this embodiment and the support and the substrate in the printed wiring board tends to be further improved.

[0164] Examples of the silane coupling agent include those generally used for surface treatment of inorganic substances. For example, aminosilane compounds (e.g., γ-aminopropyltriethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, etc.), epoxy silane compounds (e.g., γ-glycidoxypropyltrimethoxysilane, etc.), acrylic silane compounds (e.g., γ-acryloxypropyltrimethoxysilane, etc.), cationic silane compounds (e.g., N-β-(N-vinylbenzylaminoethyl)-γ-aminopropyltrimethoxysilane hydrochloride, etc.), and phenylsilane compounds. These silane coupling agents are used alone or in combination of two or more. Among these, the silane coupling agent is preferably an epoxy silane compound because it has excellent reactivity with the resin component and excellent adhesiveness to the substrate in the support and printed wiring board. Examples of the epoxy silane compound include KBM-403 (trade name), KBM-303 (trade name), KBM-402 (trade name), and KBE-403 (trade name) manufactured by Shin-Etsu Chemical Co., Ltd.

[0165] The content of the silane coupling agent is not particularly limited, but it is preferably 0.1 part by mass or more and 5 parts by mass or less with respect to 100 parts by mass of the resin solid content.

[0166] (Wetting dispersant) The resin composition according to this embodiment preferably contains a wetting dispersant. In this embodiment, by containing the wetting dispersant, the rigidity of the obtained cured product is further improved, and the warp of the printed wiring board tends to be further reduced.

[0167] Examples of the wetting dispersant include known dispersants (dispersion stabilizers) used for dispersing the filler. For example, DISPERBYK (registered trademark)-110 (trade name), 111 (trade name), 118 (trade name), 180 (trade name), 161 (trade name), W996 (trade name), W9010 (trade name), W903 (trade name), etc. manufactured by BIG CHEMIE JAPAN Co., Ltd. These wetting dispersants are used alone or in combination of two or more kinds.

[0168] The content of the wetting dispersant is preferably 1 part by mass or more and 5 parts by mass or less with respect to 100 parts by mass of the resin solid content. When the content is within the above range, the rigidity of the obtained cured product is further improved, and the warp of the printed wiring board tends to be further reduced. From the same viewpoint, the lower limit value of the content is more preferably 1.5 parts by mass, and even more preferably 2 parts by mass.

[0169] (Curing accelerator) The resin composition according to this embodiment preferably contains a curing accelerator. Examples of the curing accelerator include imidazoles (e.g., triphenylimidazole, etc.); organic peroxides (e.g., benzoyl peroxide, lauroyl peroxide, acetyl peroxide, parachlorobenzoyl peroxide, and di-tert-butyl-di-perphthalate, etc.); azo compounds (e.g., azobisisobutyronitrile, etc.); tertiary amines (e.g., N,N-dimethylbenzylamine, N,N-dimethylaniline, N,N-dimethyltoluidine, N,N-dimethylpyridine, 2-N-ethylanilinoethanol, tri-n-butylamine, pyridine, quinoline, N-methylmorpholine, triethanolamine, triethylenediamine, tetramethylbutanediamine, and N-methylpiperidine, etc.); phenols (e.g., phenol, xylenol, cresol, resorcinol, and catechol, etc.); organic metal salts (e.g., lead naphthenate, lead stearate, zinc naphthenate, zinc octylate, tin oleate, dibutyltin maleate, manganese naphthenate, cobalt naphthenate, and iron acetylacetonate, etc.); those obtained by dissolving these organic metal salts in hydroxyl group-containing compounds such as phenol and bisphenol; inorganic metal salts (e.g., tin chloride, zinc chloride, and aluminum chloride, etc.); and organotin compounds (e.g., dioctyltin oxide, other alkyltins, and alkyltin oxides, etc.). These curing accelerators are used singly or in combination of two or more. Among these, from the viewpoint of promoting the curing reaction and further improving the glass transition temperature (Tg) of the resulting cured product, the curing accelerator is preferably 2,4,5-triphenylimidazole. The content of the curing accelerator is preferably 0.1 part by mass or more and 5 parts by mass or less with respect to 100 parts by mass of the resin solid content.

[0170] (Other Additives) In the resin composition according to this embodiment, various polymer compounds such as thermosetting resins, thermoplastic resins, oligomers, and elastomers, which have not been listed so far, and additives that have not been listed so far may be included as long as the characteristics of this embodiment are not impaired. These are not particularly limited as long as they are generally used. Examples of the additives include ultraviolet absorbers, antioxidants, photopolymerization initiators, fluorescent brighteners, photosensitizers, dyes, pigments, thickeners, flow regulators, lubricants, antifoaming agents, dispersants, leveling agents, gloss agents, and polymerization inhibitors. These other additives may be used alone or in combination of two or more kinds. The content of other additives is usually 0.1 part by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the resin solid content.

[0171] (Solvent) The resin composition according to this embodiment may contain a solvent. By containing a solvent, the viscosity of the resin composition during preparation is lowered, the handleability (processability) is further improved, and the impregnability into the support tends to be further improved.

[0172] The solvent is not particularly limited as long as it can dissolve part or all of the resin component in the resin composition. Examples of the solvent include ketones (e.g., acetone, methyl ethyl ketone, and methyl cellosolve); aromatic hydrocarbons (e.g., toluene and xylene); amides (e.g., dimethylformaldehyde); propylene glycol monomethyl ether and its acetate. These solvents may be used alone or in combination of two or more kinds.

[0173] (Method for producing resin composition) As a method for manufacturing the resin composition according to this embodiment, for example, there are a method of obtaining by mixing each constituent component all at once or sequentially, and a method of formulating each constituent component all at once or sequentially into a solvent, stirring, and obtaining in the form of a varnish dissolved or dispersed in the solvent. At this time, in order to uniformly dissolve or disperse each component, known treatments such as stirring, mixing, and kneading treatments are used. Also, as the solvent, it is as described above. Regarding the specific manufacturing method, reference can be made to the examples.

[0174] 〔Support〕 As the support according to this embodiment, known ones used in various printed wiring board materials can be used, and it is preferably a resin sheet or a metal foil. The resin sheet is different from the resin sheet of this embodiment, that is, a resin sheet including a support and a layer of the resin composition disposed on the surface of the support. Examples of the resin sheet and the metal foil include resin sheets such as polyimide film, polyamide film, polyester film, polyethylene terephthalate (PET) film, polybutylene terephthalate (PBT) film, polypropylene (PP) film, and polyethylene (PE) film; and metal foils such as aluminum foil, copper foil, and gold foil. Among these, copper foil and PET film are preferred, and copper foil is more preferred because they have high heat resistance and flatness.

[0175] In this embodiment, when a copper foil is used as the support, it is possible to improve the adhesion strength between the copper foil and the layer containing the resin composition, prevent the peeling of the layer during long-term use, and since the wiring formability is excellent, the arithmetic mean roughness (Ra) of the copper foil surface in contact with the layer containing the resin composition is preferably 0.05 μm or more and 2 μm or less, more preferably 0.08 μm or more and 1.7 μm or less, and still more preferably 0.2 μm or more and 1.6 μm or less. In this embodiment, by using a copper foil having an arithmetic mean roughness within the above range as the support, a printed wiring board having high-density fine wiring formed thereon can be preferably manufactured. The arithmetic mean roughness can be measured using a commercially available surface profilometer (laser microscope, for example, VK-X210 (trade name) manufactured by Keyence Corporation). The specific measurement method is as described in the examples. Examples of the copper foil include an electrolytic copper foil, a rolled copper foil, and a copper alloy film. The copper foil and the copper film may be subjected to known surface treatments such as a matte treatment, a corona treatment, a nickel treatment, and a cobalt treatment. Commercially available products may be used as the copper foil, and examples thereof include 3EC-VLP (trade name) manufactured by Mitsui Mining & Smelting Co., Ltd., 3EC-M2S-VLP (trade name) manufactured by Mitsui Mining & Smelting Co., Ltd., MT18Ex (trade name) manufactured by Mitsui Mining & Smelting Co., Ltd., and JXUT-I (trade name) manufactured by JX Nippon Mining & Metals.

[0176] In this embodiment, when a copper foil is used as the support, since high heat resistance and reliability can be obtained, the copper foil peel strength of the layer containing the resin composition is preferably 0.5 kgf / cm or more, more preferably 0.55 kgf / cm or more, and still more preferably 0.65 kgf / cm or more and 3 kgf / cm or less. The copper foil peel strength can be measured in accordance with JIS C6481. The specific measurement method is as described in the examples.

[0177] The thickness of the support is preferably 1 μm or more and 105 μm or less, more preferably 2 μm or more and 40 μm or less, and still more preferably 10 μm or more and 25 μm or less, for reasons of economy and handleability. If the thickness of the support is less than 1 μm, roughening the surface of the support becomes difficult, and handling the resin sheet may also become difficult. On the other hand, if the thickness of the support exceeds 105 μm, it may be disadvantageous in terms of cost or drillability.

[0178] [Use] The resin sheet of this embodiment can sufficiently reduce the warp of the printed wiring board, and cracks are less likely to occur in the insulating layer of the printed wiring board, so cracks and circuit distortion in the insulating layer are less likely to occur, and excellent heat resistance and high peel strength can be exhibited. Therefore, the resin sheet of this embodiment is used, for example, in laminates, metal foil-clad laminates, printed wiring boards, and multilayer printed wiring boards. The resin sheet is suitable for printed wiring boards. The resin composition of this embodiment is also suitably used for insulating layers such as printed wiring boards and laminates.

[0179] [Laminate] In this embodiment, the resin sheet of this embodiment may be used for the laminate. The laminate includes one or more layers containing a cured product of the resin composition in the resin sheet of this embodiment. When there are a plurality of layers, the layers containing the cured product have a laminated form or a form laminated via a conductive layer such as a metal foil. By using the resin sheet of this embodiment, the laminate has sufficiently reduced warp, cracks are less likely to occur in the layer containing the cured product, so cracks in the layer containing the cured product are less likely to occur, and it has excellent heat resistance and high peel strength.

[0180] [Metal Foil-Clad Laminate] In this embodiment, the resin sheet of this embodiment may be used for a metal foil-clad laminate. The metal foil-clad laminate includes, in the resin sheet of this embodiment, a layer containing a cured product of the resin composition and metal foils disposed on one or both sides of the layer containing the cured product. The metal foil-clad laminate includes one or more layers containing a cured product of the resin composition in the resin sheet of this embodiment. When the number of layers containing the cured product is one, the metal foil-clad laminate has a form in which metal foils are disposed on one or both sides of the layer containing the cured product. When the number of layers containing the cured product is plural, the metal foil-clad laminate has a form in which metal foils are disposed on one or both sides of the laminated layers containing the cured product. By using the resin sheet of this embodiment, the metal foil-clad laminate has sufficiently reduced warpage, and cracks are less likely to occur in the layer containing the cured product, so that cracking of the layer containing the cured product is less likely to occur, and it has excellent heat resistance and high peel strength.

[0181] As the metal foil (conductor layer), any metal foil used for various printed wiring board materials may be used, and examples thereof include metal foils such as copper and aluminum. Examples of the copper metal foil include copper foils such as rolled copper foil and electrolytic copper foil. The thickness of the conductor layer is, for example, 1 μm or more and 70 μm or less, preferably 1.5 μm or more and 35 μm or less.

[0182] For the forming method of the laminate and the metal foil-clad laminate, and the forming conditions thereof, the methods and conditions for general printed wiring board laminates and multilayer boards can be applied. For example, when forming the laminate and the metal foil-clad laminate, a multi-stage press machine, a multi-stage vacuum press machine, a continuous forming machine, an autoclave forming machine, etc. can be used. Also, in the forming (laminating) of the laminate and the metal foil-clad laminate, the temperature is 100°C or more and 300°C or less, the pressure is a surface pressure of 2 kgf / cm 2 or more and 100 kgf / cm 2 or less, and the heating time is generally in the range of 0.05 hours or more and 5 hours or less. Further, post-curing can be performed at a temperature of 150°C or more and 300°C or less as necessary. For example, when using a multi-stage press machine, from the viewpoint of sufficiently promoting the curing of the resin composition in the resin sheet, the temperature is 200°C or more and 250°C or less, and the pressure is 10 kgf / cm 240 kgf / cm or less, and a heating time of 80 minutes or more and 130 minutes or less are preferred. A temperature of 215°C or more and 235°C or less, and a pressure of 25 kgf / cm 2 or more and 35 kgf / cm 2 or less, and a heating time of 90 minutes or more and 120 minutes or less are more preferred. Further, in the resin sheet of the present embodiment, a multilayer board can also be obtained by laminating and molding a layer containing a cured product of the resin composition and a wiring board for an inner layer separately prepared. 2

[0183] [Printed Wiring Board] The printed wiring board of the present embodiment includes, in the resin sheet of the present embodiment, a layer containing a cured product of the resin composition and a conductor layer disposed on the surface of the layer containing the cured product. The printed wiring board of the present embodiment can be formed, for example, by etching the metal foil of a metal foil-clad laminate into a predetermined wiring pattern to form a conductor layer. By using the resin sheet, the printed wiring board of the present embodiment has a sufficiently reduced warp, and cracks are less likely to occur in the layer containing the cured product, so that cracks in the layer containing the cured product are less likely to occur, and it has excellent heat resistance and high peel strength.

[0184] In addition, the printed wiring board of the present embodiment can also be obtained, for example, by using the resin sheet of the present embodiment as a build-up material for a metal foil-clad laminate in which an insulating layer called a core substrate is completely cured.

[0185] ​On the surface of the core substrate, a conductor circuit is usually formed by a metal foil of a metal foil laminate used in the art or a conductor layer obtained by plating after peeling the metal foil. The core substrate is not particularly limited, but mainly, a conductor layer (circuit) pattern-processed on one or both sides of substrates such as glass epoxy substrates, metal substrates, polyester substrates, polyimide substrates, bismaleimide triazine resin substrates, and thermosetting polyphenylene ether substrates is formed. In addition, an inner layer circuit board of an intermediate product on which an insulating layer and / or a conductor layer should be further formed when manufacturing a printed wiring board is also included in the circuit board referred to in this embodiment. Note that it is preferable from the viewpoint of the adhesion of the insulating layer to the circuit board that the surface of the conductor layer (circuit) has been previously roughened by a blackening treatment or the like. For the metal foil, for example, the metal foil can be referred to. For the conductor layer, for example, the conductor layer can be referred to.

[0186] In this embodiment, build-up refers to a method of laminating a layer containing a resin composition in a semi-cured state in the resin sheet of this embodiment on this surface conductor circuit. Thereafter, a printed wiring board can be obtained by performing a heat treatment or the like on the resin in a semi-cured state to completely cure it.

[0187] In the manufacture of a printed wiring board, hole processing such as via holes and / or through holes is performed as necessary to electrically connect each conductor layer. The hole processing is usually performed using a mechanical drill, a carbon dioxide laser, a UV laser, a YAG laser, or the like.

[0188] When this hole processing is performed, it is preferable to perform a roughening treatment including a desmear treatment thereafter. Note that usually, the roughening treatment consists of a swelling step, a surface roughening, a smear dissolution step, and a neutralization step.

[0189] The swelling step is performed by swelling the surface of the insulating layer using a swelling agent. The swelling agent is not particularly limited, but it is preferable that the swelling agent can swell the surface of the insulating layer to such an extent that the wettability of the surface of the insulating layer is improved and oxidative decomposition is promoted in the subsequent surface roughening and smear dissolution steps. Examples of the swelling agent include an alkaline solution and a surfactant solution.

[0190] The surface roughening and smear dissolution step is performed using an oxidizing agent. Examples of the oxidizing agent include an alkaline permanganate solution, and an aqueous solution of potassium permanganate and an aqueous solution of sodium permanganate are preferable. Such an oxidizing agent treatment is called wet desmear. In addition to wet desmear, dry desmear by plasma treatment and UV treatment, mechanical polishing by a buff or the like, and other known roughening treatments such as sandblasting may be appropriately combined and performed.

[0191] The neutralization step is to neutralize the oxidizing agent used in the previous step with a reducing agent. Examples of the reducing agent include amine-based reducing agents, and acidic aqueous solutions such as an aqueous solution of hydroxylamine sulfate, an aqueous solution of ethylenediaminetetraacetic acid, and an aqueous solution of nitrilotriacetic acid are preferable.

[0192] In the present embodiment, after providing the via hole and / or through hole, or after performing desmear treatment inside the via hole and / or through hole, it is preferable to perform a metal plating treatment in order to electrically connect each conductor layer.

[0193] The method of the metal plating treatment is not particularly limited, and the treatment method in the manufacture of a normal printed wiring board can be appropriately used. The method of the metal plating treatment and the type of the chemical solution used for plating are not particularly limited, and the treatment method and the chemical solution in the manufacture of a normal printed wiring board can be appropriately used. The chemical solution used for the metal plating treatment may be a commercially available product. Examples of the metal plating treatment method include treatment with a degreasing solution, treatment with a soft etching solution, pickling, treatment with a pre-dip solution, treatment with a catalyst solution, treatment with an accelerator solution, treatment with a chemical copper solution, pickling, and treatment by immersing in a copper sulfate solution and passing an electric current.

[0194] The metal plating step of forming a conductor layer on the layer containing the resin composition is performed, for example, by forming a conductor layer on the surface of the layer containing the resin composition having unevenness formed by roughening treatment by combining electroless plating and electroplating, or by forming a conductor layer only by electroless plating. The conductor layer can be formed of metals such as copper, aluminum, nickel, silver, and gold, and alloys of these metals, etc., but copper is more preferable. The copper plating layer can be formed by a method combining electroless copper plating and electroplating, or by forming a plating resist having a pattern opposite to that of the conductor layer and forming a conductor layer only by electroless copper plating.

[0195] Examples of the circuit formation process include the semi-additive method, the full-additive method, and the subtractive method. Among them, from the viewpoint of forming a fine wiring pattern, the semi-additive method is preferable.

[0196] Examples of the method of forming a pattern by the semi-additive method include, for example, forming a thin conductor layer on the surface of an insulating layer by electroless plating or the like, then selectively applying electroplating using a plating resist (pattern plating), then peeling off the plating resist, and etching the whole by an appropriate amount to form a wiring pattern.

[0197] When forming a wiring pattern by plating, it is preferable to perform a drying process after plating from the viewpoint of improving the adhesion strength between the insulating layer and the conductor layer. In pattern formation by the semi-additive method, electroless plating and electrolytic plating are combined, and in this case, it is preferable to perform drying after electroless plating and after electrolytic plating, respectively. The drying after electroless plating is preferably performed, for example, at 80°C or higher and 180°C or lower for 10 minutes or longer and 120 minutes or shorter. The drying after electrolytic plating is preferably performed, for example, at 130°C or higher and 220°C or lower for 10 minutes or longer and 120 minutes or shorter. As the plating, copper plating is preferable.

[0198] Also, when an insulating layer exists on the surface of the printed wiring board, the surface of this insulating layer can be treated, a conductor layer can be provided by plating or the like, and a pattern circuit can be formed using this conductor layer. When forming a pattern by plating, it is preferable to perform a roughening treatment on the surface of the insulating layer before performing the plating treatment.

[0199] As the lamination method in the build-up method, a vacuum pressure laminator can be preferably used. In this case, a method of laminating the resin sheet of the present embodiment via an elastic body such as rubber is preferable. The lamination conditions are not particularly limited as long as they are conditions generally used in the art. For example, a temperature of 70°C or higher and 140°C or lower, a contact pressure of 1 kgf / cm 2 or higher and 11 kgf / cm 2 or lower, and carried out under a reduced pressure atmosphere of 20 hPa or lower. After the lamination step, the laminated adhesive film may be smoothed by hot pressing with a metal plate. The above lamination step and smoothing step can be continuously performed by a commercially available vacuum pressure laminator. After the lamination step or after the smoothing step, a heat curing step can be performed. The heat curing step completely cures the resin composition. The heat curing conditions vary depending on the type of the resin composition and the like, but usually, the curing temperature is 170°C or higher and 190°C or lower, and the curing time is 15 minutes or longer and 60 minutes or shorter.

[0200] Also, when not using a metal foil-clad laminate, a printed wiring board may be manufactured by forming a conductor layer serving as a circuit on the layer containing the resin composition in the resin sheet of the present embodiment. At this time, an electroless plating method can also be used for forming the conductor layer.

[0201] [Multilayer Printed Wiring Board (Multilayer Core Substrate)] In the present embodiment, an insulating layer and / or a conductor layer can be further laminated on the printed wiring board to obtain a multilayer printed wiring board. The inner layer of the multilayer printed wiring board may have a circuit board. The multilayer printed wiring board of the present embodiment has sufficiently reduced warpage by using a resin sheet, and cracks are less likely to occur in the layer containing the cured product, so that cracks in the layer containing the cured product are less likely to occur, and it has excellent heat resistance and high peel strength.

[0202] The lamination method is not particularly limited, and a method generally used for lamination molding of ordinary printed wiring boards can be used. Examples of the lamination method include multi-stage press, multi-stage vacuum press, laminator, vacuum laminator, and autoclave molding machine. The lamination is appropriately selected and performed, for example, at a temperature of 100°C or higher and 300°C or lower, a pressure of 0.1 kgf / cm 2 or higher and 100 kgf / cm 2 or lower (about 9.8 kPa or higher and about 9.8 MPa or lower), and a heating time of 30 seconds or longer and 5 hours or shorter. Further, if necessary, post-curing may be performed, for example, in a temperature range of 150°C or higher and 300°C or lower to adjust the degree of curing.

[0203] [Multilayer Printed Wiring Board (Multilayer Coreless Substrate)] In this embodiment, the resin sheet of this embodiment may be used for a multilayer printed wiring board. The multilayer printed wiring board includes, for example, a plurality of insulating layers including a first insulating layer and one or more second insulating layers laminated on one side of the first insulating layer, and a first conductor layer disposed between each of the plurality of insulating layers, and a plurality of conductor layers including a second conductor layer disposed on the surface of the outermost layer of the plurality of insulating layers. The first insulating layer and the second insulating layer are each an insulating layer formed of a cured product of the resin composition in the resin sheet of this embodiment.

[0204] Examples of the multilayer printed wiring board include a so-called coreless type multilayer printed wiring board (multilayer coreless substrate) in which the second insulating layer is laminated only in one direction of the first insulating layer. In this embodiment, since an insulating layer formed of a cured product of the resin composition in the resin sheet of this embodiment is used, the multilayer printed wiring board has a sufficiently reduced warp, and cracks are less likely to occur in the layer containing the cured product, so that cracks in the layer containing the cured product are less likely to occur, and it has excellent heat resistance and high peel strength. Therefore, in this embodiment, it can be effectively used as a multilayer coreless substrate for semiconductor packages.

Examples

[0205] The present invention will be further described below using examples and comparative examples, but the present invention is not limited by these examples at all.

[0206] 〔Evaluation of Copper Foil〕 (Arithmetic Mean Roughness) The copper foil surface was photographed with a shape measurement microscope (laser microscope, VK-X210 (trade name) manufactured by Keyence Corporation) at an objective lens magnification of 150 times (magnification on a 15-inch monitor: 3000 times). Subsequently, the height distribution on a randomly selected straight line with a length of 90 μm in the photographed image was obtained by image processing, and the arithmetic mean roughness (Ra) was calculated.

[0207] 〔Synthesis Example 1〕 The α-naphthol aralkyl type cyanate ester compound (SN495VCN) was synthesized and used according to the following procedure. 0.47 mol (in terms of OH groups) of α-naphthol aralkyl resin (SN495V, OH group equivalent: 236 g / eq., manufactured by Nippon Steel Chemical Co., Ltd.; the repeating unit number n of naphthol aralkyl is 1 or more and 5 or less) was dissolved in 500 mL of chloroform, and 0.7 mol of triethylamine was added to this solution (Solution 1). While maintaining the temperature at -10°C, Solution 1 was added dropwise to 300 g of a chloroform solution in which 0.93 mol of cyanogen chloride was dissolved over 1.5 hours. After the addition was completed, the mixture was stirred for 30 minutes. Then, a mixed solution of 0.1 mol of triethylamine and 30 g of chloroform was added dropwise into the reactor, and the mixture was stirred for 30 minutes to complete the reaction. After filtering off the by-produced triethylamine hydrochloride from the reaction solution, the obtained filtrate was washed with 500 mL of 0.1 N hydrochloric acid, and then the washing with 500 mL of water was repeated 4 times. After drying this with sodium sulfate, it was dried under reduced pressure at 75°C and further degassed under reduced pressure at 90°C to obtain a brown solid α-naphthol aralkyl type cyanate ester compound represented by the above formula (1a) (wherein R 1c are all hydrogen atoms, and the repeating unit number n1 is 1 or more and 5 or less). When the obtained α-naphthol aralkyl type cyanate ester compound was analyzed by infrared absorption spectrum, absorption of the cyanate ester group was confirmed around 2264 cm -1 .

[0208] [Example 1] Biphenyl aralkyl type phenol compound (KAYAHARD (registered trademark) GPH-103 (trade name), manufactured by Nippon Kayaku Co., Ltd., hydroxyl group equivalent: 231 g / eq., represented by the above formula (2c), wherein R 2bare all hydrogen atoms, and the number of repeating units m1 is 1 or more and 6 or less) 36 parts by mass, biphenyl aralkyl type epoxy resin (NC-3000FH (trade name), epoxy equivalent: 320 g / eq., manufactured by Nippon Kayaku Co., Ltd., represented by the above formula (3b), and the number of repeating units ka is 1 or more and 6 or less) 39 parts by mass, naphthalene aralkyl type epoxy resin (HP-9900 (trade name), epoxy equivalent: 274 g / eq., manufactured by DIC Corporation, represented by the above formula (3c), and the number of repeating units ky is 1 or more and 10 or less) 7 parts by mass, bis(3-ethyl-5-methyl-4-maleimidophenyl)methane (BMI-70 (trade name, manufactured by Kay-I Chemical Co., Ltd.)) 18 parts by mass, wetting dispersant 1 (DISPERBYK (registered trademark)-161 (trade name), manufactured by BYK Japan Co., Ltd.) 1 part by mass, wetting dispersant 2 (DISPERBYK (registered trademark)-111 (trade name), manufactured by BYK Japan Co., Ltd.) 2 parts by mass, silane coupling agent (KBM-403 (trade name), manufactured by Shin-Etsu Chemical Co., Ltd.) 1 part by mass, 2,4,5-triphenylimidazole (manufactured by Tokyo Chemical Industry Co., Ltd.) 0.5 part by mass were blended (mixed), and then diluted with methyl ethyl ketone to obtain a varnish (resin composition). This varnish (resin composition) was diluted with methyl ethyl ketone and applied to the matte surface side of a copper foil (arithmetic mean roughness (Ra): 0.5 μm, 3EC-M2S-VLP (trade name), manufactured by Mitsui Mining & Smelting Co., Ltd.) having a size of 350 mm × 250 mm × 12 μm thickness by a bar coater, and heated and dried at 130 °C for 5 minutes to obtain a resin sheet having a B-stage layer containing a resin composition with a thickness of 5 μm of the layer containing the resin composition. Similarly, a varnish (resin composition) was prepared, and using this varnish, a resin sheet having a B-stage layer containing a resin composition with a thickness of 20 μm of the layer containing the resin composition was obtained.

[0209] [Example 2] In Example 1, except that 40 parts by mass of slurry silica (SC2050-MB (trade name), average particle size 0.7 μm, manufactured by Admatechs Co., Ltd.) was further added to obtain a varnish (resin composition), in the same manner as in Example 1, a resin sheet having a B-stage layer containing a resin composition with a thickness of 5 μm or 20 μm of the layer containing the resin composition was obtained.

[0210] [Example 3] In Example 1, the compounding amount of the biphenyl aralkyl type epoxy resin (NC-3000FH (trade name)) was changed from 39 parts by mass to 19 parts by mass, and the naphthylene ether type epoxy resin (HP-6000 (trade name), epoxy equivalent: 250 g / eq., manufactured by DIC Corporation, represented by the above formula (3g), and all Rs in the formula 3b are all hydrogen atoms, and the repeating unit number k1 is 2) Except that 20 parts by mass was blended, in the same manner as in Example 1, a resin sheet having a B-staged layer containing the resin composition with a thickness of the layer containing the resin composition of 5 μm or 20 μm was obtained.

[0211] [Example 4] 34 parts by mass of an α-naphthol aralkyl type cyanate ester compound (cyanate equivalent: 261 g / eq.) synthesized by the method described in Synthesis Example 1, 5 parts by mass of bis(3-ethyl-5-methyl-4-maleimidophenyl)methane (BMI-70 (trade name, manufactured by Kayaku Co., Ltd.)), 15 parts by mass of a biphenyl aralkyl type epoxy resin (NC-3000FH (trade name)), 5 parts by mass of a naphthylene ether type epoxy resin (HP-6000 (trade name)), 26 parts by mass of a dicyclopentadiene type epoxy resin (EPICRON (registered trademark) HP-7200L (trade name), epoxy equivalent: 249 g / eq., manufactured by DIC Corporation), 15 parts by mass of an epoxy resin composed of a bisphenol A type structural unit and a hydrocarbon type structural unit (EPICLON (registered trademark) EXA-4816 (trade name), manufactured by DIC Corporation, epoxy equivalent: 403 g / eq., represented by the above formula (3j)), 1 part by mass of wetting dispersant 1 (DISPERBYK (registered trademark)-161 (trade name)), 2 parts by mass of wetting dispersant 2 (DISPERBYK (registered trademark)-111 (trade name)), 1 part by mass of a silane coupling agent (KBM-403 (trade name)), and 0.5 part by mass of 2,4,5-triphenylimidazole (manufactured by Tokyo Chemical Industry Co., Ltd.) were blended (mixed), and then diluted with methyl ethyl ketone to obtain a varnish (resin composition). This varnish (resin composition) was diluted with methyl ethyl ketone and applied to the matte surface side of a copper foil (3EC-M2S-VLP (trade name)) having a thickness of 350 mm × 250 mm × 12 μm by a bar coater, and dried by heating at 130°C for 5 minutes to obtain a resin sheet having a B-stage layer containing a resin composition with an insulating resin layer thickness of 5 μm. Similarly, a varnish (resin composition) was prepared, and using this varnish, a resin sheet having a B-stage layer containing a resin composition with a layer thickness of 20 μm containing the resin composition was obtained.

[0212] [Comparative Example 1] In Example 1, except that 80 parts by mass of slurry silica (SC2050-MB (trade name), average particle size 0.7 μm) was further added to obtain a varnish (resin composition), in the same manner as in Example 1, a resin sheet having a B-stage layer containing a resin composition with a layer thickness of 5 μm or 20 μm containing the resin composition was obtained.

[0213] [Comparative Example 2] 40 parts by mass of an α-naphthol aralkyl type cyanate ester compound (cyanate equivalent: 261 g / eq.) synthesized by the method described in Synthesis Example 1, 20 parts by mass of a polyphenylmethane maleimide compound (BMI-2300 (trade name)), 40 parts by mass of a naphthylene ether type epoxy resin (HP-6000 (trade name)), 1 part by mass of wetting dispersant 1 (DISPERBYK (registered trademark)-161 (trade name)), 2 parts by mass of wetting dispersant 2 (DISPERBYK (registered trademark)-111 (trade name)), 1 part by mass of a silane coupling agent (KBM-403 (trade name)), and 0.5 part by mass of 2,4,5-triphenylimidazole (manufactured by Tokyo Chemical Industry Co., Ltd.) were blended (mixed), and then diluted with methyl ethyl ketone to obtain a varnish (resin composition). This varnish (resin composition) was diluted with methyl ethyl ketone and applied to the matte surface side of a copper foil (3EC-M2S-VLP (trade name)) having a thickness of 350 mm × 250 mm × 12 μm by a bar coater, and dried by heating at 130°C for 5 minutes to obtain a resin sheet having a B-stage layer containing the resin composition with a thickness of the layer containing the resin composition of 5 μm. Similarly, a varnish (resin composition) was prepared, and using this varnish, a resin sheet having a B-stage layer containing the resin composition with a thickness of the layer containing the resin composition of 20 μm was obtained.

[0214] [Comparative Example 3] 5 parts by mass of an α-naphthol aralkyl type cyanate ester compound (cyanate equivalent: 261 g / eq.) synthesized by the method described in Synthesis Example 1, 50 parts by mass of a polyphenylmethane maleimide compound (BMI-2300 (trade name)), 10 parts by mass of a biphenyl aralkyl type epoxy resin (NC-3000FH (trade name)), 35 parts by mass of an alkenyl-substituted nadimide compound (BANI-M (trade name), manufactured by Maruzen Petrochemical Co., Ltd.), 1 part by mass of wetting dispersant 1 (DISPERBYK (registered trademark)-161 (trade name)), 2 parts by mass of wetting dispersant 2 (DISPERBYK (registered trademark)-111 (trade name)), 1 part by mass of a silane coupling agent (KBM-403 (trade name)), and 0.5 part by mass of 2,4,5-triphenylimidazole (manufactured by Tokyo Chemical Industry Co., Ltd.) were blended (mixed), and then diluted with methyl ethyl ketone to obtain a varnish (resin composition). This varnish (resin composition) was diluted with methyl ethyl ketone and applied to the matte surface side of a copper foil (3EC-M2S-VLP (trade name)) having a thickness of 350 mm × 250 mm × 12 μm by a bar coater, and dried by heating at 130°C for 5 minutes to obtain a resin sheet having a B-stage layer containing the resin composition with a thickness of the layer containing the resin composition of 5 μm. Similarly, a varnish (resin composition) was prepared, and using this varnish, a resin sheet having a B-stage layer containing the resin composition with a thickness of the layer containing the resin composition of 20 μm was obtained.

[0215] 〔Physical Property Measurement and Evaluation〕 Using the resin sheets having a thickness of 5 μm or 20 μm of the layer containing the resin composition obtained in Examples 1 to 4 and Comparative Examples 1 to 3, samples for physical property measurement and evaluation were prepared according to the procedures shown in the following items, and the Vickers hardness, warpage amount, crack length, heat resistance, and copper foil peel strength were measured and evaluated. The results of the examples and comparative examples are summarized in Table 1.

[0216] (Vickers hardness (HV0.01)) First, using a copper foil-clad laminate 1 (HL832NSR (trade name), T / T 0.1 mmt, manufactured by Mitsubishi Gas Chemical Company, Inc.), one-sided copper foil in this copper foil-clad laminate 1 was etched to obtain an unclad board. Next, using one resin sheet with a thickness of 5 μm of the layer containing the resin composition obtained in Example 1, the layer containing the resin composition of this resin sheet was placed overlapping on the resin surface of the unclad board, and lamination molding (thermosetting) was performed at a pressure of 30 kgf / cm 2 , and a temperature of 220 °C for 120 minutes to obtain a copper foil-clad laminate 2 (size: 297 mm × 210 mm) having copper foils on both sides. Next, both copper foils were removed from the obtained copper foil-clad laminate 2 by etching to obtain a test piece (cured product). This test piece was placed on a slide glass, and the test piece was fixed to the slide glass with a cyanoacrylate-based instant adhesive (Aron Alpha (registered trademark) 201 (trade name), manufactured by Toagosei Co., Ltd.). Using a micro Vickers hardness tester (HMV-G (trade name), manufactured by Shimadzu Corporation, load 0.01 kgf, holding time 10 seconds), the Vickers hardness was measured at 7 arbitrary locations on the surface of this test piece, and the average value was calculated. Regarding the resin sheets with a thickness of 5 μm of the layer containing the resin composition obtained in Examples 2 to 4 and Comparative Examples 1 to 3, the Vickers hardness was measured in the same manner.

[0217] (Amount of warpage: bimetal method) First, using a copper foil-clad laminate 1 (HL832NSR (trade name), T / T 0.1 mmt, manufactured by Mitsubishi Gas Chemical Company, Inc.), one-sided copper foil in this copper foil-clad laminate 1 was etched to obtain an unclad board. Next, using one resin sheet with a thickness of 5 μm of the layer containing the resin composition obtained in Example 1, the layer containing the resin composition of this resin sheet was placed overlapping on the resin surface of the unclad board, and lamination molding was performed at a pressure of 30 kgf / cm 2And perform lamination molding (thermosetting) at a temperature of 220°C for 120 minutes to obtain a copper-clad laminate 2 (size: 297 mm × 210 mm) having copper foils on both sides. Next, remove the copper foils from both sides of the obtained copper-clad laminate 2 by etching to obtain a laminate. Thereafter, one end in the short side direction of the laminate was attached to a vertical surface with a magnet, and a straightedge (ruler) was applied parallel to the plane, and the distance between the vertical surface and the laminate was measured. In the laminate, the resin surface derived from the copper-clad laminate 1 was attached to the vertical surface. The measurement was performed at a total of 8 locations, including the central locations of the four sides and the four corners of the laminate. An average value was calculated from these measured values, and this average value was taken as the "amount of warpage" by the bimetal method. When the amount of warpage was less than 10 mm, it was designated as "AA", and otherwise as "CC". Similarly, for the resin sheets having a thickness of 5 μm of the layer containing the resin composition obtained in Examples 2 to 4 and Comparative Examples 1 to 3, the amount of warpage was measured and evaluated respectively.

[0218] (Crack length) Using one resin sheet having a thickness of 20 μm of the layer containing the resin composition obtained in Example 1, the layer containing the resin composition of this resin sheet was stacked on a copper foil (3EC-M2S-VLP (trade name), thickness 12 μm, manufactured by Mitsui Mining & Smelting Co., Ltd.) and arranged under a pressure of 30 kgf / cm 2 And perform lamination molding (thermosetting) at a temperature of 220°C for 120 minutes to obtain a copper-clad laminate. Remove the copper foils from both sides of the obtained copper-clad laminate by etching to obtain a test piece (cured product). This test piece was placed on a slide glass, and a load was applied at 10 locations with a micro Vickers hardness tester (HMV-G (trade name), manufactured by Shimadzu Corporation, load 2 kgf, holding time 15 seconds). For these 10 locations, the presence or absence of the occurrence of cross-shaped cracks was confirmed. When cracks occurred, the longitudinal and transverse lengths of the cracks were measured respectively. When no cracks were observed, the crack length was set to 0. From the longitudinal and transverse lengths of the cracks at 10 locations, an average value of the crack length was calculated. When this average value was 200 μm or less, it was designated as "AA", and otherwise as "CC". Regarding the resin sheets with a thickness of 20 μm of the layer containing the resin composition obtained in Examples 2 to 4 and Comparative Examples 1 to 3, in the same manner, the average value of the crack length was measured and evaluated for each of them.

[0219] (Heat resistance) First, using a copper-clad laminate 1 (HL832NSR (trade name) T / T 0.8 mmt, manufactured by Mitsubishi Gas Chemical Company, Inc.), the copper foil surfaces on both sides of this copper-clad laminate 1 were etched by about 1 to 3 μm (inner layer roughening treatment, CZ-8100 (trade name), manufactured by Meck Co., Ltd.). Then, on each of the two sides, the resin sheet with a thickness of 5 μm of the layer containing the resin composition obtained in Example 1 was arranged so that the layer surface containing the resin composition was on the inside, and lamination molding (thermosetting) was performed at a pressure of 30 kgf / cm 2 , a temperature of 220 °C for 120 minutes to obtain a copper-clad laminate 2. The obtained copper-clad laminate 2 was cut (downsizing) to a size of 50 mm × 50 mm to obtain a measurement sample. The obtained sample was left in a constant temperature bath at 120 °C for 1 hour as a pretreatment, and then immersed in a solder bath at 260 °C for 30 seconds to evaluate the heat resistance. After 30 seconds, for each of the surfaces of the copper-clad laminate 1, the presence or absence of delamination between the copper foil on the surface of the copper-clad laminate 1 and the cured product layer of the layer containing the resin composition in the resin sheet was confirmed. The case where delamination did not occur on both sides was designated as "AA", and the case where delamination occurred on either surface was designated as "CC". Regarding the resin sheets with a thickness of 5 μm of the layer containing the resin composition obtained in Examples 2 to 4 and Comparative Examples 1 to 3, in the same manner, the presence or absence of delamination was confirmed for each of them, and the heat resistance was evaluated.

[0220] (Copper foil peel strength) First, using a copper foil-clad laminate 1 (HL832NSR (trade name), T / T 0.1 mmt, manufactured by Mitsubishi Gas Chemical Company, Inc.), the copper foil surfaces on both sides of this copper foil-clad laminate 1 were etched to about 1 to 3 μm (inner layer roughening treatment, CZ-8100 (trade name), manufactured by Meck Co., Ltd.). Then, on each of the two sides thereof, the resin sheet having a thickness of 5 μm of the layer containing the resin composition obtained in Example 1 was arranged such that the layer surface containing the resin composition faced inward, and lamination molding (thermosetting) was performed at a pressure of 30 kgf / cm 2 and a temperature of 220°C for 120 minutes to obtain a copper foil-clad laminate 2. Using the obtained copper foil-clad laminate 2, in accordance with JIS C6481, the peel strength (kgf / cm) of the copper foil in the normal state was measured at three arbitrary locations on one outer layer. Similarly, for the other outer layer, the peel strength (kgf / cm) of the copper foil in the normal state was measured at three arbitrary locations. The average value was calculated from the values of those peel strengths (six points), and this average value was taken as the copper foil peel strength. For the resin sheets having a thickness of 5 μm of the layer containing the resin composition obtained in Examples 2 to 4 and Comparative Examples 1 to 3, the copper foil peel strength (average value) was calculated in the same manner, respectively.

[0221]

Table 1

[0222] This application is based on a Japanese patent application filed on December 17, 2019 (Japanese Patent Application No. 2019-227427), the content of which is incorporated herein by reference.

Industrial Applicability

[0223] The resin sheet of this embodiment is suitable for, for example, laminates, metal foil-clad laminates, printed wiring boards, and multilayer printed wiring boards.

Claims

1. A resin sheet comprising a support and a layer containing a resin composition disposed on the surface of the support, wherein the resin composition contains a cyanate ester compound and / or a phenol compound, an epoxy compound and / or a maleimide compound, and one or more selected from the group consisting of the cyanate ester compound, the phenol compound, the epoxy compound, and the maleimide compound contains a compound having a biphenyl skeleton, the content of the compound having a biphenyl skeleton is 15 parts by mass or more with respect to 100 parts by mass of the resin solid content in the resin composition, when one or more selected from the group consisting of the cyanate ester compound, the phenol compound, the epoxy compound, and the maleimide compound contains a compound having a polycyclic aromatic group, the content of the compound having a polycyclic aromatic group is less than 40 parts by mass with respect to 100 parts by mass of the resin solid content in the resin composition, when the resin composition contains an inorganic filler, the content of the inorganic filler is 60 parts by mass or less with respect to 100 parts by mass of the resin solid content in the resin composition, the Vickers hardness (HV0.01) of the cured product of the resin composition is 10 or more and 19 or less, the thickness of the layer containing the resin composition is 2 μm or more and 20 μm or less, a resin sheet.

2. The resin sheet according to claim 1, wherein the cyanate ester compound contains a compound represented by the following formula (1a). 【Chemical 1】 (In formula (1a), R 1c each independently represents a hydrogen atom or a methyl group. n1 represents an integer of 1 or more and 10 or less.).

3. The resin sheet according to claim 1 or 2, wherein the phenol compound contains a compound represented by the following formula (2a). 【Chemical Formula 2】 (In formula (2a), Ar 1 each independently represents a benzene ring or a naphthalene ring. Ar 2 represents a benzene ring, a naphthalene ring, or a biphenyl ring. R 2a each independently represents a hydrogen atom or a methyl group. m represents an integer of 1 or more and 50 or less. Each ring may have a substituent other than a hydroxyl group.).

4. The resin sheet according to any one of claims 1 to 3, wherein the epoxy compound contains a compound represented by the following formula (3a). [Chemical Formula 3] (In formula (3a), Ar 3 each independently represents a benzene ring or a naphthalene ring. Ar 4 represents a benzene ring, a naphthalene ring, or a biphenyl ring. R 3a each independently represents a hydrogen atom or a methyl group. k represents an integer of 1 or more and 50 or less. Each ring may have a substituent other than a glycidyloxy group.).

5. The resin sheet according to any one of claims 1 to 4, wherein the maleimide compound contains a compound represented by the following formula (4a). 【Chemical Formula 4】 (In formula (4a), R 4a and R 5a each independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. R 4b each independently represents a hydrogen atom or a methyl group. s represents an integer of 1 or more.).

6. The resin sheet according to any one of claims 1 to 5, wherein the thickness of the layer containing the resin composition is 2 μm or more and 15 μm or less.

7. The resin sheet according to any one of claims 1 to 6, wherein the thickness of the support is 1 μm or more and 105 μm or less.

8. The support is a copper foil, the arithmetic mean roughness (Ra) of the copper foil surface in contact with the layer containing the resin composition is 0.05 μm or more and 2 μm or less, a resin sheet according to any one of claims 1 to 7.

9. The copper foil peel strength of the layer containing the resin composition is 0.5 kgf / cm or more. The resin sheet according to claim 8.

10. A layer containing a cured product of the resin composition according to any one of claims 1 to 9, A conductor layer disposed on the surface of the layer containing the cured product, A printed wiring board comprising the same.

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