Resin material, cured product, and multilayer printed wiring board

Abstract

Provided is a resin material that makes it possible to suppress warpage of a cured product and that makes it possible to increase peel strength with respect to a metal layer.　A resin material according to the present invention comprises a curable compound (A), a curing agent (B), and a thermoplastic resin (C), wherein the thermoplastic resin (C) contains a thermoplastic resin (C1) having a softening point not lower than 120°C and a polyimide resin (C2) having a softening point not higher than 110°C.

Description

Resin material, cured product, and multilayer printed wiring board

[0001] The present invention relates to a resin material containing a curable compound, a curing agent, and a thermoplastic resin. The present invention also relates to a cured product of the above resin material. Further, the present invention relates to a multilayer printed wiring board using the above resin material.

[0002] Conventionally, various resin materials have been used to obtain electronic components such as semiconductor devices, laminates, and printed wiring boards. For example, in a multilayer printed wiring board, a resin material is used to form an insulating layer for insulating between internal layers or to form an insulating layer located in the surface layer portion. Wires, which are generally made of metal, are laminated on the surface of the insulating layer. In addition, a film-like resin material (resin film) may be used to form the insulating layer. The above resin material is used as an insulating material for a multilayer printed wiring board including a build-up film.

[0003] Patent Document 1 below discloses a resin composition containing (A) an epoxy resin, (B) an active ester compound, and (C) an inorganic filler, wherein (A) the epoxy resin contains a modified epoxy resin having a specific structure, and (C) when the content of the inorganic filler is 100% by mass of the non-volatile components in the resin composition, it is 50% by mass or more. Patent Document 1 also describes that it is preferable that the above resin composition contains a rubber component such as core-shell type rubber particles.

[0004] Japanese Unexamined Patent Application Publication No. 2022-088223

[0005] In conventional resin materials, the cured product of the resin material may warp. When warping occurs in the cured product, cracks may occur in the cured product, or warping may also occur in the circuit board and the metal layer accompanying the cured product. In particular, in recent years, with the increase in the size of circuit boards in printed wiring boards, large internal stresses are likely to occur in the cured product, and therefore, warping of the cured product is also likely to occur.

[0006] To alleviate internal stress, it is conceivable to incorporate rubber components, such as rubber particles, into the resin material as a stress-relieving agent, as described in Patent Document 1. However, simply incorporating rubber components reduces the strength of the cured product, thus reducing the peel strength against the metal layer.

[0007] The object of the present invention is to provide a resin material that can suppress warping of the cured product and increase the peel strength against the metal layer. The present invention also aims to provide a cured product of the above resin material. Furthermore, the present invention aims to provide a multilayer printed circuit board using the above resin material.

[0008] This specification discloses the following resin materials, cured products, and multilayer printed circuit boards.

[0009] Item 1. A resin material comprising a curable compound (A), a curing agent (B), and a thermoplastic resin (C), wherein the thermoplastic resin (C) comprises a thermoplastic resin (C1) having a softening point of 120°C or higher and a polyimide resin (C2) having a softening point of 110°C or lower.

[0010] Item 2. The resin material according to Item 1, wherein the polyimide resin (C2) is a reaction product of tetracarboxylic acid and dimeramine.

[0011] Item 3. The resin material according to item 1 or 2, wherein the content of the polyimide resin (C2) in 100% by weight of the thermoplastic resin (C) is 1% by weight or more and 55% by weight or less.

[0012] Item 4. The resin material according to any one of items 1 to 3, wherein the thermoplastic resin (C1) is a polyimide resin.

[0013] Item 5. The resin material according to any one of items 1 to 4, wherein the curable compound (A) is a thermosetting compound.

[0014] Item 6. The resin material according to any one of items 1 to 5, wherein the curable compound (A) comprises an epoxy compound.

[0015] Item 7. The resin material according to any one of items 1 to 6, wherein the curing agent (B) comprises an active ester compound.

[0016] Item 8. A resin material according to any one of items 1 to 7, further comprising an inorganic filler (D).

[0017] Item 9. The resin material according to Item 8, wherein the content of the inorganic filler (D) is 50% by weight or more of 100% by weight of the components excluding the solvent in the resin material.

[0018] Item 10. A resin material according to any one of items 1 to 9, wherein when the resin material is heated at 190°C for 90 minutes to obtain a cured product of the resin material, the dielectric loss tangent of the obtained cured product is 0.004 or less.

[0019] Item 11. A resin film, which is a resin material according to any one of items 1 to 10.

[0020] Item 12. A resin material according to any one of items 1 to 11, used for forming an insulating layer in a multilayer printed circuit board.

[0021] Item 13. A cured product of a resin material, wherein the resin material is a resin material described in any one of items 1 to 12.

[0022] Item 14. A multilayer printed circuit board comprising a circuit board, a plurality of insulating layers disposed on the surface of the circuit board, and a metal layer disposed between the plurality of insulating layers, wherein at least one of the plurality of insulating layers is a cured product of the resin material described in any one of items 1 to 12.

[0023] The resin material according to the present invention comprises a curable compound (A), a curing agent (B), and a thermoplastic resin (C). In the resin material according to the present invention, the thermoplastic resin (C) comprises a thermoplastic resin (C1) having a softening point of 120°C or higher and a polyimide resin (C2) having a softening point of 110°C or lower. Because the resin material according to the present invention has the above configuration, it is possible to suppress warping of the cured product and to increase the peel strength against the metal layer.

[0024] Figure 1 is a schematic cross-sectional view showing a multilayer printed circuit board using a resin material according to one embodiment of the present invention.

[0025] The details of the present invention will be described below.

[0026] (Resin Material) The resin material according to the present invention comprises a curable compound (A), a curing agent (B), and a thermoplastic resin (C). In the resin material according to the present invention, the thermoplastic resin (C) comprises a thermoplastic resin (C1) having a softening point of 120°C or higher and a polyimide resin (C2) having a softening point of 110°C or lower.

[0027] The resin material according to the present invention has the above-described configuration, which makes it possible to suppress warping of the cured product and to increase the peel strength against the metal layer.

[0028] The manufacturing process for printed circuit boards includes a reflow process. Therefore, resin materials are required to have stability and reliability at high temperatures. The inventors attempted to reduce internal stress and suppress warping of the cured product by deliberately using a thermoplastic resin with a relatively low softening point. However, the inventors found that when a thermoplastic resin with a relatively low softening point was simply used, even if warping of the cured product could be suppressed to some extent, the peel strength against the metal layer decreased. As a result of diligent research, the inventors found that by using a combination of a thermoplastic resin with a relatively high softening point (C1) and a polyimide resin with a relatively low softening point (C2), warping of the cured product could be suppressed and the peel strength against the metal layer could be increased.

[0029] The resin material according to the present invention can effectively suppress warping of the cured product, thereby effectively suppressing the occurrence of cracks in the cured product. The resin material according to the present invention can increase the peel strength against the metal layer, thereby improving the adhesion between the insulating layer (cured resin layer) and the metal layer.

[0030] Furthermore, the resin material according to the present invention can reduce the dielectric loss tangent of the cured product.

[0031] The resin material according to the present invention may be a resin composition or a resin film. The resin composition may be fluid. The resin composition may be in paste form. The paste form includes a liquid form. The resin material according to the present invention is preferably a resin film because of its excellent handling properties.

[0032] The resin material according to the present invention is preferably a thermosetting resin material. If the resin material is a resin film, the resin film is preferably a thermosetting resin film.

[0033] In the following explanation, "100% by weight of the component excluding the solvent in the above resin material" means 100% by weight of the component excluding the solvent in the above resin material if the above resin material contains a solvent, and 100% by weight of the above resin material if the above resin material does not contain a solvent.

[0034] Furthermore, in the following explanation, "100% by weight of the components excluding the inorganic filler (D) and solvent in the above resin material" means 100% by weight of the components excluding the inorganic filler (D) and solvent in the above resin material if the above resin material contains the inorganic filler (D) and solvent. "100% by weight of the components excluding the inorganic filler (D) and solvent in the above resin material" means 100% by weight of the components excluding the inorganic filler (D) in the above resin material if the above resin material contains the inorganic filler (D) but does not contain a solvent. "100% by weight of the components excluding the inorganic filler (D) and solvent in the above resin material" means 100% by weight of the components excluding the solvent in the above resin material if the above resin material does not contain the inorganic filler (D) but contains a solvent. "100% by weight of the components excluding the inorganic filler (D) and solvent in the above resin material" means 100% by weight of the above resin material if the above resin material does not contain the inorganic filler (D) and does not contain a solvent. "100% by weight of the components excluding the inorganic filler (D) and solvent in the above resin material" means 100% by weight of the non-volatile components excluding the inorganic filler (D) in the above resin material.

[0035] The following describes the details of each component used in the resin material according to the present invention, as well as the applications of the resin material according to the present invention.

[0036] [Curable Compound (A)] The above resin material contains curable compound (A). Examples of curable compound (A) include thermosetting compounds and photocurable compounds. Only one type of curable compound (A) may be used, or two or more types may be used in combination.

[0037] Examples of the above-mentioned thermosetting compounds include styrene compounds, phenoxy compounds, oxetane compounds, epoxy compounds, maleimide compounds, vinyl compounds, benzoxazine compounds, polyarylate compounds, diallyl phthalate compounds, acrylate compounds, episulfide compounds, (meth)acrylic compounds, amino compounds, unsaturated polyester compounds, polyurethane compounds, and silicone compounds.

[0038] Examples of the above-mentioned photocurable compounds include (meth)acrylic compounds.

[0039] In the above resin material, excluding the solvent, the content of curable compound (A) in 100% by weight is preferably 5% by weight or more, more preferably 10% by weight or more, preferably 80% by weight or less, and more preferably 60% by weight or less. When the content of curable compound (A) is above the lower limit and below the upper limit, the resin material can be cured well.

[0040] The curable compound (A) is preferably a thermosetting compound. The resin material preferably contains a thermosetting compound.

[0041] The above thermosetting compound is preferably an epoxy compound, a maleimide compound, a vinyl compound, or a benzoxazine compound, more preferably containing an epoxy compound or a maleimide compound, and even more preferably containing an epoxy compound. The curable compound (A) is preferably an epoxy compound, a maleimide compound, a vinyl compound, or a benzoxazine compound, more preferably containing an epoxy compound or a maleimide compound, and even more preferably containing an epoxy compound. In these cases, the dielectric loss tangent of the cured product can be further reduced, and the thermal dimensional stability of the cured product can be further improved.

[0042] <Epoxy Compound> The above resin material preferably contains an epoxy compound. Conventionally known epoxy compounds can be used as the epoxy compound. The epoxy compound is an organic compound having at least one epoxy group. Only one epoxy compound may be used, or two or more may be used in combination.

[0043] As the above epoxy compound, there may be mentioned bisphenol A type epoxy compounds, bisphenol F type epoxy compounds, bisphenol S type epoxy compounds, phenol novolak type epoxy compounds, biphenyl type epoxy compounds, biphenyl novolak type epoxy compounds, bisphenol type epoxy compounds, naphthalene type epoxy compounds, fluorene type epoxy compounds, phenol aralkyl type epoxy compounds, naphthol aralkyl type epoxy compounds, dicyclopentadiene type epoxy compounds, anthracene type epoxy compounds, epoxy compounds having an adamantane skeleton, epoxy compounds having a tricyclodecane skeleton, naphthylene ether type epoxy compounds, and epoxy compounds having a triazine nucleus in the skeleton, etc.

[0044] The above epoxy compound may be a glycidyl ether compound. The above glycidyl ether compound is a compound having at least one glycidyl ether group.

[0045] It is preferable that the above epoxy compound contains an epoxy compound having an aromatic skeleton, more preferably contains an epoxy compound having a naphthalene skeleton or a phenyl skeleton, and even more preferably is an epoxy compound having an aromatic skeleton. In this case, the dielectric loss tangent of the cured product can be made even lower. Also, the thermal dimensional stability and flame retardancy of the cured product can be further enhanced.

[0046] It is preferable that the above epoxy compound contains a liquid epoxy compound at 25°C and a solid epoxy compound at 25°C. In this case, the dielectric loss tangent of the cured product can be made even lower, and the linear expansion coefficient (CTE) of the cured product can be made even smaller.

[0047] The viscosity at 25°C of the above epoxy compound that is liquid at 25°C is preferably 1000 mPa·s or less, and more preferably 500 mPa·s or less.

[0048] The viscosity of the above epoxy compound can be measured using, for example, a dynamic viscoelasticity measuring device (such as "VAR-100" manufactured by Rheologica Instruments Co., Ltd.).

[0049] The molecular weight of the epoxy compound is preferably 1000 or less. In this case, even if the inorganic filler (D) content is 50% or more of the 100% by weight of the components excluding the solvent in the resin material, a resin material with high fluidity during the formation of the insulating layer can be obtained. Therefore, when the uncured or B-staged resin material is laminated onto a circuit board, the inorganic filler (D) can be uniformly distributed.

[0050] The molecular weight of the epoxy compound described above refers to the molecular weight that can be calculated from the structural formula of the epoxy compound, if the epoxy compound is not a polymer, or if the structural formula of the epoxy compound can be identified. If the epoxy compound is a polymer, it refers to the weight-average molecular weight.

[0051] In the above resin material, excluding the solvent, the content of the epoxy compound is preferably 5% by weight or more, more preferably 10% by weight or more, preferably 80% by weight or less, and more preferably 60% by weight or less. If the content of the epoxy compound is above the lower limit, the thermal dimensional stability of the cured product can be further improved. If the content of the epoxy compound is below the upper limit, the dielectric loss tangent of the cured product can be further reduced.

[0052] <Maleimide Compound> The above resin material preferably contains a maleimide compound. Conventionally known maleimide compounds can be used as the above maleimide compound. Only one maleimide compound may be used, or two or more may be used in combination.

[0053] The above maleimide compound may have one maleimide group, two maleimide groups, two or more maleimide groups, three or more maleimide groups, four or more maleimide groups, 800 or fewer maleimide groups, 500 or fewer maleimide groups, or 300 or fewer maleimide groups.

[0054] The above maleimide compound may also be a bismaleimide compound.

[0055] Examples of the bismaleimide compounds mentioned above include N-phenylmaleimide and N-alkylbismaleimide.

[0056] The above maleimide compounds may have an aliphatic or alicyclic skeleton.

[0057] Examples of the above aliphatic skeleton include a chain-like aliphatic skeleton, such as saturated hydrocarbon groups and unsaturated hydrocarbon groups. The above aliphatic skeleton is preferably an aliphatic skeleton having four or more carbon atoms. The number of carbon atoms in the aliphatic skeleton having four or more carbon atoms is preferably five or more, more preferably six or more, even more preferably seven or more, preferably six0 or less, even more preferably five0 or less, and even more preferably four0 or less. More specifically, examples of the above aliphatic skeleton include alkyl groups having four to sixty carbon atoms (preferably alkyl groups having six to fourty carbon atoms). The above maleimide compound may have only one of the above aliphatic skeletons, or it may have two or more of them.

[0058] Examples of the alicyclic skeletons mentioned above include monocycloalkane rings, bicycloalkane rings, tricycloalkane rings, tetracycloalkane rings, and dicyclopentadiene rings. The maleimide compound may have only one of the alicyclic skeletons, or it may have two or more.

[0059] The above maleimide compound preferably has a skeleton derived from a dimeramine. Since maleimide compounds having a skeleton derived from a dimeramine have an aliphatic skeleton and an alicyclic skeleton, using such a maleimide compound can further reduce the dielectric constant and dielectric loss tangent of the cured product.

[0060] The above maleimide compound may or may not have an aromatic skeleton.

[0061] Examples of the above aromatic skeletons include benzene rings, naphthalene rings, anthracene rings, phenanthrene rings, tetracene rings, chrysene rings, triphenylene rings, tetrafen rings, pyrene rings, pentacene rings, picene rings, and perylene rings. The above maleimide compound may have only one of the above aromatic skeletons, or it may have two or more.

[0062] Examples of commercially available maleimide compounds include "BMI-3000J" and "BMI-689" manufactured by Designer Molecules Inc., "MIR-3000-70MT" manufactured by Nippon Kayaku Co., Ltd., and "BMI" and "BMI-70" manufactured by K.I. Co., Ltd.

[0063] In the above resin material, excluding the solvent, the content of the maleimide compound is preferably 2.5% by weight or more, more preferably 5% by weight or more, preferably 60% by weight or less, and more preferably 50% by weight or less. When the content of the maleimide compound is above the lower limit and below the upper limit, the thermal dimensional stability of the cured product can be further improved.

[0064] <Vinyl Compound> The above resin material preferably contains a vinyl compound. Conventionally known vinyl compounds can be used as the vinyl compound. The vinyl compound is an organic compound having at least one vinyl group. Only one vinyl compound may be used, or two or more may be used in combination.

[0065] Examples of the vinyl compounds mentioned above include divinylbenzyl ether compounds.

[0066] In the above resin material, excluding the solvent, the content of the vinyl compound is preferably 1% by weight or more, more preferably 5% by weight or more, preferably 60% by weight or less, and more preferably 50% by weight or less. When the content of the vinyl compound is above the lower limit and below the upper limit, the dielectric constant and dielectric loss tangent of the cured product can be further reduced, and the thermal dimensional stability of the cured product can be further improved.

[0067] <Benzoxazine Compound> The above resin material preferably contains a benzoxazine compound. Conventionally known benzoxazine compounds can be used as the benzoxazine compound. Only one benzoxazine compound may be used, or two or more may be used in combination.

[0068] Examples of the above-mentioned benzoxazine compounds include P-d type benzoxazine and F-a type benzoxazine.

[0069] Examples of commercially available benzoxazine compounds include "P-d type" manufactured by Shikoku Chemicals Co., Ltd.

[0070] In the above resin material, excluding the solvent, the content of the benzoxazine compound is preferably 1% by weight or more, more preferably 5% by weight or more, preferably 60% by weight or less, and more preferably 50% by weight or less. When the content of the benzoxazine compound is above the lower limit and below the upper limit, the thermal dimensional stability of the cured product can be further improved.

[0071] [Curing agent (B)] The above resin material contains a curing agent (B). The curing agent (B) may be a thermosetting agent or a photocuring agent. The curing agent (B) can be appropriately selected depending on the type of curable compound (A). Only one type of curing agent (B) may be used, or two or more types may be used in combination.

[0072] Examples of curing agents (B) include active ester compounds (active ester curing agents), phenol compounds (phenol curing agents), cyanate ester compounds (cyanate ester curing agents), carbodiimide compounds (carbodiimide curing agents), amine compounds (amine curing agents), thiol compounds (thiol curing agents), phosphine compounds, dicyandiamides, and acid anhydrides.

[0073] From the viewpoint of more effectively exhibiting the effects of the present invention and further lowering the dielectric loss tangent of the cured product, the curing agent (B) preferably contains an active ester compound, a phenol compound, or a cyanate ester compound, and more preferably contains an active ester compound or a cyanate ester compound and a phenol compound.

[0074] From the viewpoint of exhibiting the effects of the present invention more effectively and further lowering the dielectric loss tangent of the cured product, the curing agent (B) preferably contains an active ester compound, and more preferably contains an active ester compound and a phenol compound.

[0075] <Activated Ester Compound> The curing agent (B) preferably contains an activated ester compound. The activated ester compound refers to a compound having at least one ester bond, with aliphatic chains, aliphatic rings, or aromatic rings bonded to both sides of the ester bond. The activated ester compound can be obtained, for example, by a condensation reaction between a carboxylic acid compound or a thiocarboxylic acid compound and a hydroxy compound or a thiol compound. Only one activated ester compound may be used, or two or more may be used in combination.

[0076] Examples of the above-mentioned active ester compounds include compounds represented by the following formula (1).

[0077]

[0078] In formula (1) above, X1 represents a group having an aliphatic chain, a group having an aliphatic ring, or a group having an aromatic ring, and X2 represents a group having an aromatic ring. Preferred examples of the group having an aromatic ring include a benzene ring which may have substituents, and a naphthalene ring which may have substituents. Examples of substituents include hydrocarbon groups. The number of carbon atoms in the hydrocarbon group is preferably 1 or more, preferably 12 or less, more preferably 6 or less, and even more preferably 4 or less.

[0079] In formula (1) above, examples of combinations of X1 and X2 include a combination of a benzene ring which may have a substituent and a benzene ring which may have a substituent, and a combination of a benzene ring which may have a substituent and a naphthalene ring which may have a substituent. Furthermore, in formula (1) above, examples of combinations of X1 and X2 include a combination of a naphthalene ring which may have a substituent and a naphthalene ring which may have a substituent.

[0080] The above-mentioned active ester compound is not particularly limited. From the viewpoint of further improving the thermal dimensional stability and flame retardancy of the cured product, it is preferable that the above-mentioned active ester compound is an active ester compound having two or more aromatic rings. The above-mentioned active ester compound having two or more aromatic rings may have 10 or fewer aromatic rings, 5 or fewer, 3 or fewer, or 2. From the viewpoint of lowering the dielectric loss tangent of the cured product and improving the thermal dimensional stability of the cured product, it is more preferable that the above-mentioned active ester compound has a naphthalene ring or a dicyclopentadiene skeleton in its main chain skeleton.

[0081] Examples of commercially available active ester compounds include DIC Corporation's "HPC-8000-65T", "HPC-8000L-65MT", "EXB9416-70BK", "HPC-8150-62T", "EXB-8", and "EXB8100-65T".

[0082] <Phenol Compounds> The curing agent (B) preferably contains phenol compounds. The above phenol compounds may be used individually or in combination of two or more.

[0083] Examples of the phenol compounds mentioned above include novolac-type phenols, biphenol-type phenols, naphthalene-type phenols, dicyclopentadiene-type phenols, aralkyl-type phenols, and dicyclopentadiene-type phenols.

[0084] Examples of commercially available phenol compounds include novolac-type phenols (DIC Corporation's "TD-2091"), biphenylnovolac-type phenols (Meiwa Chemical Industries, Ltd.'s "MEH-7851"), aralkyl-type phenols (Meiwa Chemical Industries, Ltd.'s "MEH-7800"), and phenols having an aminotriazine skeleton (DIC Corporation's "LA-1356" and "LA-3018-50P").

[0085] <Cyanate ester compound> The curing agent (B) preferably contains a cyanate ester compound. The above cyanate ester compound may be used alone or in combination of two or more types.

[0086] Examples of the above-mentioned cyanate ester compounds include novolac-type cyanate ester resins, bisphenol-type cyanate ester resins, and prepolymers in which these are partially trimerized. Examples of the above-mentioned novolac-type cyanate ester resins include phenol novolac-type cyanate ester resins and alkylphenol-type cyanate ester resins. Examples of the above-mentioned bisphenol-type cyanate ester resins include bisphenol A-type cyanate ester resins, bisphenol E-type cyanate ester resins, and tetramethylbisphenol F-type cyanate ester resins.

[0087] Examples of commercially available cyanate ester compounds include phenol novolac type cyanate ester resins (PT-30 and PT-60 from Lonza Japan Co., Ltd.) and prepolymers in which bisphenol type cyanate ester resins have been trimerized (BA-230S, BA-3000S, BTP-1000S, and BTP-6020S from Lonza Japan Co., Ltd.).

[0088] <Carbodiimide Compounds> The curing agent (B) preferably contains a carbodiimide compound. The above carbodiimide compound may be used alone or in combination of two or more.

[0089] The above carbodiimide compound is a compound having a structural unit represented by the following formula (2). In formula (2), the rightmost and leftmost ends are bonding sites with other groups. The above carbodiimide compound may be used alone, or two or more may be used in combination.

[0090]

[0091] In formula (2) above, X represents an alkylene group, a group to which a substituent is attached to an alkylene group, a cycloalkylene group, a group to which a substituent is attached to a cycloalkylene group, an arylene group, or a group to which a substituent is attached to an arylene group, and p represents an integer from 1 to 5. If there are multiple X's, they may be the same or different.

[0092] In one preferred embodiment, at least one X is an alkylene group, a group to which a substituent is attached to an alkylene group, a cycloalkylene group, or a group to which a substituent is attached to a cycloalkylene group.

[0093] Examples of commercially available carbodiimide compounds include "Carbodilite V-02B," "Carbodilite V-03," "Carbodilite V-04K," "Carbodilite V-07," "Carbodilite V-09," "Carbodilite 10M-SP," and "Carbodilite 10M-SP (modified)" manufactured by Nisshinbo Chemical Co., Ltd., as well as "Stabaczol P," "Stabaczol P400," and "Hycadyl 510" manufactured by Rhein Chemie Corporation.

[0094] <Further Details of Curing Agent (B)> In the above resin material, the content of curing agent (B) per 100 parts by weight of curable compound (A) is preferably 50 parts by weight or more, more preferably 70 parts by weight or more, even more preferably 85 parts by weight or more, preferably 200 parts by weight or less, more preferably 150 parts by weight or less, and even more preferably 120 parts by weight or less. When the content of curing agent (B) is above the lower limit and below the upper limit, the curability is further improved, the thermal dimensional stability is further enhanced, and the volatilization of residual unreacted components can be further suppressed.

[0095] When the above resin material contains an epoxy compound, the content of the curing agent (B) in the above resin material is preferably 50 parts by weight or more, more preferably 70 parts by weight or more, even more preferably 85 parts by weight or more, preferably 200 parts by weight or less, more preferably 150 parts by weight or less, and even more preferably 120 parts by weight or less, per 100 parts by weight of the epoxy compound. When the content of the curing agent (B) is above the lower limit and below the upper limit, the curability is further improved, the thermal dimensional stability is further enhanced, and the volatilization of residual unreacted components can be further suppressed.

[0096] [Thermoplastic resin (C)] The above resin material includes a thermoplastic resin (C). The thermoplastic resin (C) includes a thermoplastic resin (C1) having a softening point of 120°C or higher and a polyimide resin (C2) having a softening point of 110°C or lower.

[0097] The softening point of the thermoplastic resin (C) can be determined using a differential scanning calorimetry device (for example, TA Instruments' "Q2000"), by heating it from -30°C to 260°C in a nitrogen atmosphere at a heating rate of 3°C / min, and then determining the inflection point of the reverse heat flow.

[0098] <Thermoplastic resin (C1) with a softening point of 120°C or higher> The above resin material includes a thermoplastic resin (C1). Examples of thermoplastic resin (C1) include polyvinyl acetal resin, polyimide resin, and phenoxy resin. Only one type of thermoplastic resin (C1) may be used, or two or more types may be used in combination.

[0099] From the viewpoint of effectively lowering the dielectric loss tangent of the cured product and effectively improving the adhesion of metal wiring, the thermoplastic resin (C1) is preferably a polyimide resin or a phenoxy resin, and more preferably a polyimide resin. When the thermoplastic resin (C1) is a polyimide resin, the dielectric loss tangent of the cured product can be lowered even more effectively.

[0100] The polyimide resin, which is the thermoplastic resin (C1), is not particularly limited. Conventionally known polyimide resins can be used as the polyimide resin. Only one type of polyimide resin may be used, or two or more types may be used in combination.

[0101] From the viewpoint of improving solubility, the polyimide resin, which is the thermoplastic resin (C1), is preferably a polyimide resin that is a reaction product of tetracarboxylic acid and dimeramine. The tetracarboxylic acid may also be a tetracarboxylic dianhydride.

[0102] The softening point of the thermoplastic resin (C1) is 120°C or higher. Preferably, the softening point of the thermoplastic resin (C1) is 125°C or higher, more preferably 130°C or higher, more preferably 200°C or lower, more preferably 180°C or lower, and even more preferably 150°C or lower. When the above softening point is above the lower limit and below the upper limit, the effects of the present invention can be exhibited even more effectively.

[0103] The weight-average molecular weight of the thermoplastic resin (C1) is preferably 5,000 or more, more preferably 10,000 or more, more preferably 100,000 or less, and more preferably 50,000 or less. When the above weight-average molecular weight is above the lower limit and below the upper limit, the effects of the present invention can be exhibited even more effectively.

[0104] The weight-average molecular weight of thermoplastic resin (C1) refers to the weight-average molecular weight in polystyrene terms, measured by gel permeation chromatography (GPC).

[0105] The content of thermoplastic resin (C1) in 100% by weight of thermoplastic resin (C) is preferably 40% by weight or more, more preferably 45% by weight or more, preferably 99% by weight or less, and more preferably 95% by weight or less. When the content of thermoplastic resin (C1) is above the lower limit and below the upper limit, the effects of the present invention can be exhibited even more effectively.

[0106] In the above resin material, excluding the inorganic filler (D) and solvent, the content of thermoplastic resin (C1) in 100% by weight of the components is preferably 1% by weight or more, more preferably 5% by weight or more, preferably 30% by weight or less, and more preferably 15% by weight or less. When the content of thermoplastic resin (C1) is above the lower limit and below the upper limit, the effects of the present invention can be exhibited even more effectively.

[0107] <Polyimide resin (C2) with a softening point of 110°C or lower> The above resin material includes polyimide resin (C2). By using polyimide resin (C2), the internal stress of the cured product can be effectively relieved, and therefore, warping of the cured product can be effectively suppressed. The reason why internal stress can be effectively relieved by using polyimide resin (C2) is thought to be due to the softening and molecular motion of the polyimide resin (C2) when the resin material is heated, but the reason is not limited to this. Only one type of polyimide resin (C2) may be used, or two or more types may be used in combination.

[0108] The polyimide resin (C2) is not particularly limited as long as its softening point is 110°C or lower.

[0109] From the viewpoint of improving solubility, the polyimide resin (C2) is preferably a polyimide resin which is a reaction product of tetracarboxylic acid and dimeramine. The tetracarboxylic acid may also be a tetracarboxylic dianhydride.

[0110] Examples of the above tetracarboxylic dianhydrides include pyromellitic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 3,3',4,4'-biphenylsulfonetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 3,3',4,4'-biphenylethertetracarboxylic dianhydride, 3,3',4,4'-dimethyldiphenylsilanetetracarboxylic dianhydride, 3,3',4,4'-tetraphenylsilanetetracarboxylic dianhydride, 1,2,3,4-furantetracarboxylic dianhydride, and 4,4'-bis(3,4-dicarboxyphenoxy)diphenyl Examples include sulfide dianhydrides, 4,4'-bis(3,4-dicarboxyphenoxy)diphenylsulfone dianhydride, 4,4'-bis(3,4-dicarboxyphenoxy)diphenylpropane dianhydride, 3,3',4,4'-perfluoroisopropylidene diphthalic acid dianhydride, 3,3',4,4'-biphenyltetracarboxylic acid dianhydride, bis(phthalic acid)phenylphosphine oxide dianhydride, p-phenylene-bis(triphenylphthalic acid) dianhydride, m-phenylene-bis(triphenylphthalic acid) dianhydride, bis(triphenylphthalic acid)-4,4'-diphenylter dianhydride, and bis(triphenylphthalic acid)-4,4'-diphenylmethane dianhydride.

[0111] Examples of the above-mentioned dimer amines include Versamin 551 (trade name, manufactured by BASF Japan, 3,4-bis(1-aminoheptyl)-6-hexyl-5-(1-octenyl)cyclohexene), Versamin 552 (trade name, manufactured by Cognics Japan, a hydrogenated version of Versamin 551), PRIAMINE 1075, PRIAMINE 1074 (trade names, both manufactured by Croda Japan), and others.

[0112] The softening point of the polyimide resin (C2) is 110°C or lower. Preferably, the softening point of the polyimide resin (C2) is 0°C or higher, more preferably 40°C or higher, even more preferably 50°C or higher, preferably 105°C or lower, and more preferably 100°C or lower. When the above softening point is above the lower limit and below the upper limit, the effects of the present invention can be exhibited even more effectively.

[0113] The weight-average molecular weight of the polyimide resin (C2) is preferably 5,000 or more, more preferably 10,000 or more, more preferably 100,000 or less, and more preferably 50,000 or less. When the above weight-average molecular weight is above the lower limit and below the upper limit, the effects of the present invention can be exhibited even more effectively.

[0114] The weight-average molecular weight of polyimide resin (C2) refers to the weight-average molecular weight in polystyrene terms, measured by gel permeation chromatography (GPC).

[0115] The content of polyimide resin (C2) in 100% by weight of thermoplastic resin (C) is preferably 1% by weight or more, more preferably 5% by weight or more, preferably 55% by weight or less, and more preferably 50% by weight or less. When the content of polyimide resin (C2) is above the lower limit and below the upper limit, the effects of the present invention can be exhibited even more effectively.

[0116] In the above resin material, excluding the inorganic filler (D) and solvent, the content of polyimide resin (C2) in 100% by weight of the components is preferably 0.1% by weight or more, more preferably 0.5% by weight or more, preferably 7% by weight or less, and more preferably 6% by weight or less. When the content of polyimide resin (C2) is above the lower limit and below the upper limit, the effects of the present invention can be exhibited even more effectively.

[0117] <Further details of thermoplastic resin (C)> Thermoplastic resin (C) may or may not contain a thermoplastic resin different from both thermoplastic resin (C1) and polyimide resin (C2).

[0118] In 100% by weight of thermoplastic resin (C), the total content of thermoplastic resin (C1) and polyimide resin (C2) is preferably 10% by weight or more, more preferably 50% by weight or more, even more preferably 70% by weight or more, still more preferably 80% by weight or more, even more preferably 90% by weight or more, particularly preferably 95% by weight or more, and preferably 100% by weight (total amount) or less. In 100% by weight of thermoplastic resin (C), the total content of thermoplastic resin (C1) and polyimide resin (C2) is most preferably 100% by weight (total amount). When the above total content is above the above lower limit, the effects of the present invention can be exhibited more effectively. In 100% by weight of thermoplastic resin (C), the total content of thermoplastic resin (C1) and polyimide resin (C2) may be 100% by weight or less, may be less than 100% by weight, or may be 99% by weight or less.

[0119] In the above resin material, excluding the inorganic filler (D) and solvent, the content of thermoplastic resin (C) in 100% by weight of the components is preferably 1% by weight or more, more preferably 3% by weight or more, preferably 20% by weight or less, and more preferably 15% by weight or less. When the content of thermoplastic resin (C) is above the lower limit and below the upper limit, the effects of the present invention can be exhibited even more effectively.

[0120] [Inorganic Filler (D)] The above resin material may or may not contain the inorganic filler (D). The above resin material may or may not contain the inorganic filler (D). It is preferable that the above resin material contains the inorganic filler (D). The use of the inorganic filler (D) can further reduce the dielectric loss tangent of the cured product. In addition, the use of the inorganic filler (D) further reduces the dimensional change of the cured product due to heat. Only one type of inorganic filler (D) may be used, or two or more types may be used in combination.

[0121] Examples of inorganic fillers (D) include silica, talc, clay, mica, hydrotalcite, alumina, magnesium oxide, aluminum hydroxide, diamond, aluminum nitride, and boron nitride.

[0122] The inorganic filler (D) is preferably silica or alumina, more preferably silica, and even more preferably fused silica. In this case, the surface roughness of the cured product can be reduced, and the adhesive strength between the cured product and the metal layer can be further increased. Furthermore, fine wiring can be formed on the surface of the cured product, providing the cured product with better insulation reliability. When the inorganic filler (D) is silica, the thermal expansion coefficient of the cured product becomes even lower, and the dielectric loss tangent of the cured product becomes even lower. Note that the silica may be hollow silica.

[0123] From the viewpoint of increasing thermal conductivity and insulation, the inorganic filler (D) is preferably alumina or boron nitride. In particular, since boron nitride has anisotropy, the coefficient of thermal expansion can be made even smaller.

[0124] The average particle size of the inorganic filler (D) is preferably 50 nm or more, more preferably 100 nm or more, even more preferably 500 nm or more, preferably 5 μm or less, more preferably 3 μm or less, and even more preferably 1 μm or less. When the average particle size of the inorganic filler (D) is above the lower limit and below the upper limit, the surface roughness after etching can be reduced, the plating peel strength can be increased, and the adhesion between the insulating layer and the metal layer can be further improved.

[0125] The median diameter (d50), which accounts for 50% of the inorganic filler (D), is used as the average particle size. The above average particle size can be measured using a laser diffraction scattering particle size distribution analyzer. In the case of aggregated particles of the inorganic filler (D), the average particle size of the inorganic filler (D) refers to the primary particle size.

[0126] The inorganic filler (D) is preferably spherical, and more preferably spherical silica. In this case, the surface roughness of the cured product is effectively reduced, and the adhesive strength between the cured product and the metal layer is effectively increased. When the inorganic filler (D) is spherical, the aspect ratio of the inorganic filler (D) is preferably 1 or more, preferably 2 or less, and more preferably 1.5 or less.

[0127] The inorganic filler (D) is preferably surface-treated, more preferably surface-treated with a coupling agent, and even more preferably surface-treated with a silane coupling agent. Surface treatment of the inorganic filler (D) further reduces the surface roughness of the roughened cured product and further increases the adhesive strength between the cured product and the metal layer. Furthermore, surface treatment of the inorganic filler (D) allows for the formation of even finer wiring on the surface of the cured product and provides the cured product with even better insulation reliability between wirings and between layers.

[0128] Examples of the coupling agents mentioned above include silane coupling agents, titanium coupling agents, and aluminum coupling agents. Examples of the silane coupling agents mentioned above include methacrylicsilane, acrylicsilane, aminosilane, imidazolesilane, vinylsilane, and epoxysilane.

[0129] In the above resin material, excluding the solvent, the content of inorganic filler (D) in 100% by weight is preferably 30% by weight or more, more preferably 40% by weight or more, even more preferably 50% by weight or more, still more preferably 60% by weight or more, particularly preferably 65% ​​by weight or more, preferably 90% by weight or less, more preferably 85% by weight or less, and still more preferably 80% by weight or less. If the content of inorganic filler (D) is above the lower limit, the dielectric loss tangent of the cured product can be further reduced. If the content of inorganic filler (D) is below the upper limit, the thermal dimensional stability of the cured product can be improved, and warping of the cured product can be effectively suppressed. If the content of inorganic filler (D) is above the lower limit and below the upper limit, the surface roughness of the surface of the cured product can be further reduced, and finer wiring can be formed on the surface of the cured product. Furthermore, if the content of inorganic filler (D) is above the lower limit and below the upper limit, it is also possible to lower the thermal expansion coefficient of the cured product and improve smear removal properties at the same time.

[0130] [Curing Accelerator] The above resin material may or may not contain a curing accelerator. The above resin material may or may not contain a curing accelerator. It is preferable that the above resin material contains a curing accelerator. The curing speed is further increased by using the above curing accelerator. By rapidly curing the resin material, the crosslinking structure in the cured product becomes uniform, the number of unreacted functional groups decreases, and as a result the crosslinking density increases. Furthermore, by using the above curing accelerator, the resin material can be cured well even at relatively low temperatures. The above curing accelerator may be used alone, or two or more may be used in combination.

[0131] Examples of the curing accelerators mentioned above include anionic curing accelerators such as imidazole compounds; cationic curing accelerators such as amine compounds; curing accelerators other than anionic and cationic curing accelerators such as organophosphorus compounds and organometallic compounds; and radical curing accelerators such as peroxides and azo compounds.

[0132] The above imidazole compounds include 2-undecylimidazole, 2-heptadecylimidazole, 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1,2-dimethylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole trimellitate, and 1-cyanoethyl-2-phenylimidazole tri Examples include melite, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-undecylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isocyanurate adduct, 2-phenylimidazole isocyanurate adduct, 2-methylimidazole isocyanurate adduct, 2-phenyl-4,5-dihydroxymethylimidazole, and 2-phenyl-4-methyl-5-dihydroxymethylimidazole.

[0133] Examples of the above-mentioned amine compounds include diethylamine, triethylamine, diethylenetetramine, triethylenetetramine, diethylenetriamine, ethylenediamine, tris(dimethylaminomethyl)phenol, benzyldimethylamine, m-xylylenedi(dimethylamine), N,N'-dimethylpiperazine, N-methylpyrrolidine, N-methylhydrooxypiperidine, m-xylylenediamine, isophoronediamine, N-aminoethylpiperazine, polyoxypropylene polyamine, and 4,4-dimethylaminopyridine. Furthermore, the amine compounds may be modified versions of these amine compounds.

[0134] Examples of the above-mentioned organophosphorus compounds include organophosphine compounds such as triphenylphosphine, tricyclohexylphosphine, trybenzylphosphine, diphenyl(alkylphenyl)phosphine, tris(alkylphenyl)phosphine, tris(alkoxyphenyl)phosphine, tris(alkylalkoxyphenyl)phosphine, tris(dialkylphenyl)phosphine, tris(trialkylphenyl)phosphine, tris(tetraalkylphenyl)phosphine, tris(dialkoxyphenyl)phosphine, tris(trialkoxyphenyl)phosphine, tris(tetraalkoxyphenyl)phosphine, trialkylphosphine, dialkylarylphosphine, and alkyldiarylphosphine, as well as phosphonium salt compounds such as tetraphenylphosphonium and tetraphenylborate.

[0135] Examples of the organometallic compounds mentioned above include zinc naphthenate, cobalt naphthenate, tin octoate, cobalt octoate, bisacetylacetonate cobalt(II), and trisacetylacetonate cobalt(III).

[0136] Examples of the above-mentioned peroxides include diacyl peroxides, peroxyesters, peroxydicarbonates, monoperoxycarbonates, peroxyketals, dialkyl peroxides, dibenzyl peroxides, dicumyl peroxides, hydroperoxides, and ketone peroxides.

[0137] From the viewpoint of further lowering the curing temperature and effectively suppressing warping of the cured product, the curing accelerator preferably contains an anionic curing accelerator, and more preferably contains an imidazole compound.

[0138] The content of the curing accelerator is not particularly limited. In 100% by weight of the components of the resin material excluding the inorganic filler (D) and solvent, the content of the curing accelerator is preferably 0.01% by weight or more, more preferably 0.05% by weight or more, preferably 5% by weight or less, and more preferably 3% by weight or less. When the content of the curing accelerator is above the lower limit and below the upper limit, the resin material cures efficiently. If the content of the curing accelerator is within a more preferable range, the storage stability of the resin material is further improved, and an even better cured product can be obtained.

[0139] [Solvent] The above resin material may or may not contain a solvent. The above resin material may or may not contain a solvent. By using the above solvent, the viscosity of the resin material can be controlled to a suitable range and the coating properties of the resin material can be improved. The above solvent may also be used to obtain a slurry containing an inorganic filler (D). Only one type of solvent may be used, or two or more types may be used in combination.

[0140] Examples of the above-mentioned solvents include acetone, methanol, ethanol, butanol, 2-propanol, 2-methoxyethanol, 2-ethoxyethanol, 1-methoxy-2-propanol, 2-acetoxy-1-methoxypropane, toluene, xylene, methyl ethyl ketone, N,N-dimethylformamide, methyl isobutyl ketone, N-methyl-pyrrolidone, n-hexane, cyclohexane, cyclohexanone, and naphtha, which is a mixture of these solvents.

[0141] Preferably, most of the above solvent is removed when the resin composition is formed into a film. Therefore, the boiling point of the above solvent is preferably 200°C or lower, more preferably 180°C or lower, and may be 30°C or higher, 50°C or higher, or 100°C or higher. The amount of the above solvent in the resin composition is not particularly limited. The amount of the above solvent can be appropriately changed considering the coating properties of the resin composition.

[0142] When the above resin material is a B-stage film, the content of the above solvent in 100% by weight of the B-stage film is preferably 1% by weight or more, more preferably 2% by weight or more, preferably 15% by weight or less, and more preferably 10% by weight or less.

[0143] [Other Components] For the purpose of improving impact resistance, heat resistance, resin compatibility, and workability, the above resin material may contain other components in addition to those described above. Examples of these other components include organic fillers, leveling agents, flame retardants, coupling agents, colorants, antioxidants, UV degradation inhibitors, defoamers, thickeners, thixotropy-inducing agents, etc. Only one of these other components may be used, or two or more may be used in combination.

[0144] The above resin material may or may not contain glass cloth. It is preferable that the above resin material does not contain glass cloth. It is preferable that the above resin material is not a prepreg.

[0145] (Resin Film) A resin film (B-stage compound / B-stage film) is obtained by molding the above-mentioned resin composition into a film. The above-mentioned resin material is preferably a resin film. The resin film is preferably a B-stage film.

[0146] The following methods can be used to form a resin film from a resin composition: Extrusion molding, in which the resin composition is melt-kneaded and extruded using an extruder, and then formed into a film using a T-die or circular die; Casting molding, in which a resin composition containing a solvent is cast into a film; and other conventionally known film molding methods. Extrusion molding or casting molding is preferred because it allows for thinning. The film includes sheets.

[0147] A resin film that is a B-stage film can be obtained by forming the resin composition into a film and then heating and drying it for 1 to 10 minutes at, for example, 50°C to 150°C, so as not to cause excessive curing by heat.

[0148] The film-like resin composition obtained through the drying process described above is referred to as a B-stage film. The B-stage film is in a semi-cured state. The semi-cured material is not completely cured and can undergo further curing.

[0149] The above-mentioned resin film does not have to be a prepreg. If the above-mentioned resin film is not a prepreg, migration along the glass cloth, etc., will not occur. Also, when laminating or precuring the resin film, the surface will not become uneven due to the glass cloth.

[0150] The above-mentioned resin film can be used in the form of a laminated film comprising a metal foil or a base film and a resin film laminated on the surface of the metal foil or base film. The above-mentioned metal foil is preferably copper foil.

[0151] Examples of the base film of the laminated film include polyester resin films such as polyethylene terephthalate film and polybutylene terephthalate film, olefin resin films such as polyethylene film and polypropylene film, and polyimide resin films. The surface of the base film may be treated with a release agent as needed.

[0152] From the viewpoint of controlling the degree of curing of the resin film more uniformly, the thickness of the resin film is preferably 5 μm or more, and preferably 200 μm or less. When the resin film is used as an insulating layer of a circuit, the thickness of the insulating layer formed by the resin film is preferably greater than or equal to the thickness of the conductor layer (metal layer) forming the circuit. The thickness of the insulating layer is preferably 5 μm or more, and preferably 200 μm or less.

[0153] (Further details of the resin material) When the above resin material is heated at 190°C for 90 minutes to obtain a cured product of the resin material, the dielectric loss tangent (Df) of the obtained cured product is preferably 0.004 or less, more preferably 0.0038 or less. The dielectric loss tangent (Df) of the obtained cured product is preferably 0 or more. The range of the dielectric loss tangent (Df) of the obtained cured product can be set by appropriately selecting the above lower limit and upper limit values.

[0154] The dielectric loss tangent (Df) of the above cured product can be measured as follows: The resin material is heated at 190°C for 90 minutes to obtain a cured resin material. The dielectric loss tangent (Df) of the obtained cured product is measured using the cavity resonance method at room temperature (23°C) and a frequency of 5.8 GHz, using a "Cavity Resonance Perturbation Method Dielectric Constant Measurement Device CP521" manufactured by Kanto Electronics Applied Development Co., Ltd. and a "Network Analyzer N5224A PNA" manufactured by Keysight Technologies.

[0155] Furthermore, when manufacturing electronic components such as multilayer substrates using the above-mentioned resin material, the cured product may be obtained by heating at 190°C for 90 minutes, or the cured product may be obtained by heating the resin material under heating conditions other than those specified above.

[0156] The above-mentioned resin material can be used in a variety of applications. For example, it is suitably used to form a mold resin for embedding semiconductor chips in semiconductor devices. It is also suitably used as a substitute for liquid crystal polymer (LCP), in millimeter-wave antennas, and in redistribution layers. The above-mentioned resin material is not limited to the above applications and is suitably used in all wiring formation applications.

[0157] The above resin material is suitably used as an adhesive material. For example, the above resin material is suitably used as an adhesive material for power overlay packages, an adhesive material for printed circuit boards, an adhesive material for coverlays of flexible printed circuit boards, and an adhesive material for semiconductor bonding. The above resin material is preferably an adhesive material.

[0158] The above resin material is suitably used as an insulating material. The above resin material is suitably used to form an insulating layer in a printed circuit board (use of the above resin material for forming an insulating layer in a printed circuit board). The above resin material is more suitably used to form an insulating layer in a multilayer printed circuit board (use of the above resin material for forming an insulating layer in a multilayer printed circuit board). The above resin material is preferably an insulating material, and more preferably an interlayer insulating material. The above insulating material may also serve as an adhesive material.

[0159] The cured product according to the present invention is a cured product of a resin material obtained by curing the resin material described above. The cured product according to the present invention is a cured product of a resin material, wherein the resin material is the resin material described above. The cured product according to the present invention can be obtained by curing the resin material described above. The heating conditions for the resin material when obtaining the cured product according to the present invention are not particularly limited, as long as the resin material hardens.

[0160] (Laminated Structure and Copper-Clad Laminate) A laminated structure can be obtained by laminating a lamination target member having a metal layer on one or both sides of its surface onto the above-mentioned resin film. The above-mentioned laminated structure comprises a lamination target member having a metal layer on its surface and a resin film laminated on the surface of the metal layer, wherein the resin film is the above-mentioned resin material. The method of laminating the above-mentioned resin film and the lamination target member is not particularly limited, and known methods can be used. For example, the above-mentioned resin film can be laminated onto the lamination target member while heating or under pressure without heating using a device such as a parallel plate press or a roll laminator.

[0161] The material of the above metal layer is preferably copper.

[0162] The laminated member having the above-mentioned metal layer on its surface may be a metal foil such as copper foil.

[0163] The above-mentioned resin material is suitably used to obtain a copper-clad laminate. An example of the above-mentioned copper-clad laminate is a copper-clad laminate comprising a copper foil and a resin film laminated on one surface of the copper foil, wherein the resin film is the above-mentioned resin material.

[0164] The thickness of the copper foil in the copper-clad laminate is not particularly limited. Preferably, the thickness of the copper foil is 1 μm or more and 100 μm or less. Furthermore, in order to increase the adhesive strength between the cured resin material and the copper foil, it is preferable that the copper foil has fine irregularities on its surface. The method for forming the irregularities is not particularly limited. Examples of methods for forming the irregularities include methods using known chemical solutions, methods using known plasma treatment, and methods using known UV treatment.

[0165] (Circuit board with insulating layer) The above resin material is suitably used to obtain a circuit board with an insulating layer. An example of the above circuit board with an insulating layer is a circuit board comprising a circuit board and an insulating layer disposed on the surface of the circuit board, wherein the insulating layer is a cured product of the above resin material.

[0166] In the above-described circuit board with insulating layer, it is preferable that the insulating layer is laminated on the surface of the circuit board on which the circuits are provided. In the above-described circuit board with insulating layer, it is preferable that a portion of the insulating layer is embedded between the circuits.

[0167] The above-mentioned circuit board with an insulating layer can be obtained by conventionally known methods.

[0168] (Multilayer substrates and multilayer printed wiring boards) The above resin material is suitably used to obtain multilayer substrates. An example of the above multilayer substrate is a multilayer substrate comprising a circuit board and an insulating layer laminated on the circuit board. The insulating layer of the above multilayer substrate is a cured product of the above resin material. The insulating layer is preferably laminated on the surface of the circuit board on which the circuits (metal layers) are provided. A part of the insulating layer is preferably embedded between the circuits.

[0169] In the above-described multilayer substrate, it is preferable that the surface of the insulating layer opposite to the surface on which the circuit board is laminated is roughened.

[0170] The roughening treatment method can be any conventionally known roughening treatment method and is not particularly limited. The surface of the insulating layer may be swollen before the roughening treatment.

[0171] Furthermore, it is preferable that the multilayer substrate further comprises a copper plating layer laminated on the roughened surface of the insulating layer.

[0172] Another example of the multilayer substrate described above is a multilayer substrate comprising a circuit board, an insulating layer laminated on the surface of the circuit board, and a copper foil laminated on the surface of the insulating layer opposite to the surface on which the circuit board is laminated. Preferably, the insulating layer is formed by curing the resin film using a copper-clad laminate comprising a copper foil and a resin film laminated on one surface of the copper foil. Furthermore, it is preferable that the copper foil is etched and forms a copper circuit.

[0173] Another example of the multilayer substrate described above is a multilayer substrate comprising a circuit board and a plurality of insulating layers laminated on the surface of the circuit board. At least one of the plurality of insulating layers arranged on the circuit board is formed using the resin material. Preferably, the multilayer substrate further comprises a circuit laminated on at least one surface of the insulating layers formed using the resin film.

[0174] The above-mentioned resin material is suitably used to form an insulating layer in a multilayer printed circuit board (use of the above-mentioned resin material for forming an insulating layer in a multilayer printed circuit board).

[0175] The multilayer printed circuit board described above comprises, for example, a circuit board, a plurality of insulating layers disposed on the surface of the circuit board, and a metal layer disposed between the plurality of insulating layers. In the multilayer printed circuit board described above, at least one of the plurality of insulating layers is a cured product of the resin material described above.

[0176] Figure 1 is a schematic cross-sectional view showing a multilayer printed circuit board using a resin material according to one embodiment of the present invention.

[0177] In the multilayer printed circuit board 11 shown in Figure 1, a plurality of insulating layers 13 to 16 are laminated on the upper surface 12a of the circuit board 12. The insulating layers 13 to 16 are cured material layers. A metal layer 17 is formed in a portion of the upper surface 12a of the circuit board 12. Of the plurality of insulating layers 13 to 16, a metal layer 17 is formed in a portion of the upper surface of insulating layers 13 to 15, excluding insulating layer 16 located on the outer surface opposite to the circuit board 12. The metal layer 17 is a circuit. Metal layers 17 are arranged between the circuit board 12 and the insulating layer 13, and between each layer of the laminated insulating layers 13 to 16. The lower metal layer 17 and the upper metal layer 17 are connected to each other by at least one of via-hole connections and through-hole connections (not shown).

[0178] In the multilayer printed circuit board 11, the insulating layers 13 to 16 are formed from cured resin material. In this embodiment, the surfaces of the insulating layers 13 to 16 are roughened, so fine pores (not shown) are formed on the surfaces of the insulating layers 13 to 16. The metal layer 17 extends into the interior of these fine pores. In addition, in the multilayer printed circuit board 11, the width dimension (L) of the metal layer 17 and the width dimension (S) of the portion where the metal layer 17 is not formed can be reduced. Furthermore, in the multilayer printed circuit board 11, good insulation reliability is provided between the upper metal layer and the lower metal layer that are not connected by via-hole connections and through-hole connections (not shown).

[0179] The present invention will be specifically described below with reference to examples and comparative examples. The present invention is not limited to the following examples.

[0180] The following materials were prepared.

[0181] (Curable Compounds (A)) Bisphenol A type epoxy compound (Mitsubishi Chemical Corporation "828US") Biphenyl novolac type epoxy compound (Nippon Kayaku Co., Ltd. "NC-3000") Tetramethylbiphenyl type epoxy compound (Mitsubishi Chemical Corporation "YX4000")

[0182] (Curing agent (B)) Active ester compound-containing liquid (DIC Corporation "HPC-8000L-65MT", solids content 65% by weight) Cyanate ester compound (Lonza Japan Corporation "BA-3000S") Phenolic compound-containing liquid (DIC Corporation "LA-1356", solids content 60% by weight)

[0183] (Thermoplastic resin (C)) Thermoplastic resin (C1): Polyimide resin (softening point 130°C, "PIAD300" manufactured by Arakawa Chemical Industries, Ltd., solids content 30% by weight) Phenoxy resin (softening point 130°C, "YX6954-BH30" manufactured by Mitsubishi Chemical Corporation) Polyimide resin with an indan skeleton (softening point above 130°C, synthesized by Synthesis Example 1 below)

[0184] <Synthesis Example 1> A 500 mL separable flask was prepared, equipped with a moisture meter connected to a reflux condenser, a nitrogen inlet tube, and a stirrer. 20.3 g of 4,4'-oxydiphthalic anhydride (ODPA), 200 g of γ-butyrolactone, 20 g of toluene, and 29.6 g of 5-(4-aminophenoxy)-3-[4-(4-aminophenoxy)phenyl]-1,1,3-trimethylindan were added to this flask, and the reaction was carried out by stirring at 45°C for 2 hours under a nitrogen stream. Next, the reaction solution was heated and maintained at approximately 160°C, and the condensed water was removed azeotropically with toluene under a nitrogen stream. It was confirmed that a predetermined amount of water had accumulated in the moisture meter and that no water outflow was observed. After confirmation, the reaction solution was further heated and stirred at 200°C for 1 hour. Subsequently, the mixture was cooled to obtain a varnish containing 20% ​​by weight of a polyimide resin having a 1,1,3-trimethylindan skeleton. The weight-average molecular weight of the obtained polyimide resin was 12,000.

[0185] Polyimide resin (C2): Polyimide resin (softening point 80°C, Arakawa Chemical Industries, Ltd. "PIAD150L", solids content 30% by weight) Polyimide resin (softening point 100°C, Arakawa Chemical Industries, Ltd. "PIAD200", solids content 30% by weight)

[0186] Other thermoplastic resins: Thermoplastic resins with a hyperbranch structure (softening point 80°C, synthesized by synthesis example 2 below)

[0187] <Synthesis Example 2> 1.94 g of 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane and acetone were added to a reaction vessel to dissolve 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane in acetone. Next, 0.922 g of cyanuric acid chloride, 0.946 g of terminally amine-modified silicone oil (Shin-Etsu Chemical Co., Ltd. "KF-8010"), and 0.553 g of N-phenyl-3-aminopropyltrimethoxysilane (Shin-Etsu Chemical Co., Ltd. "KBE-903") were added to this reaction vessel and reacted overnight at 50°C. Ethyl acetate was then added for extraction, and insoluble matter was removed by filtration. Next, the filtrate was washed with water, dehydration was performed with anhydrous magnesium sulfate, and the solvent was concentrated and removed by distillation. The residue was crystallized with methanol to obtain a thermoplastic resin having a hyperbranched structure. The weight-average molecular weight of the obtained thermoplastic resin was 21600.

[0188] (Inorganic filler (D)) Silica-containing slurry (75% by weight silica, Admatex "SC4050-HOA", average particle size 1.0 μm, phenylaminosilane treated, 25% by weight cyclohexanone)

[0189] (Curing accelerator) Imidazole compound (2-phenyl-4-methylimidazole, manufactured by Shikoku Chemicals Co., Ltd. as "2P4MZ", anionic curing accelerator)

[0190] (Examples 1-7 and Comparative Examples 1-4) The components shown in Tables 1-4 below were blended in the amounts (in parts by weight of solids) shown in Tables 2-4 below, and stirred at room temperature until a uniform solution was obtained to obtain a resin material.

[0191] Preparation of resin film: Using an applicator, the obtained resin material was coated onto the release-treated surface of a release-treated polyethylene terephthalate film (PET film, Toray Industries "XG284", 25 μm thick), and then dried in a 100°C gear oven for 2 minutes and 30 seconds to evaporate the solvent. In this way, a laminated film (a laminated film of PET film and resin film) was obtained in which a resin film (B-stage film) with a thickness of 40 μm was laminated on the PET film.

[0192] (Evaluation) (1) Dielectric loss tangent (Df) of the cured material The obtained resin film was heated at 190°C for 90 minutes to obtain a cured material. The obtained cured material was cut into pieces with a width of 2 mm and a length of 80 mm, and 10 pieces were stacked together. The dielectric loss tangent was measured at room temperature (23°C) at a frequency of 5.8 GHz using the cavity resonance method with a "Cavity Resonance Perturbation Method Dielectric Constant Measurement Device CP521" manufactured by Kanto Electronics Applied Development Co., Ltd. and a "Network Analyzer N5224A PNA" manufactured by Keysight Technologies.

[0193] [Criteria for determining the dielectric loss tangent (Df) of hardened material] ○: Dielectric loss tangent is 0.004 or less △: Dielectric loss tangent exceeds 0.004

[0194] (2) Curing of the hardened material The obtained laminated film was cut to a size of 14 cm x 15 cm. In addition, copper foil (thickness 35 μm, manufactured by Mitsui Mining & Smelting Co., Ltd.) cut to 15 cm x 16 cm was prepared. Using a batch-type vacuum pressure laminator (Meiki Seisakusho Co., Ltd. "Batch-type vacuum laminator MVLP-500-IIA"), the resin film side of the laminated film was laminated onto the shiny side of the copper foil to produce copper foil with laminated film. The lamination was performed by reducing the pressure to 13 hPa or less for 30 seconds, and then pressing at a pressure of 0.7 MPa at 70°C for 30 seconds. The four sides of the obtained copper foil with laminated film were attached with glass cloth tape so that the laminated film was on the top surface. This copper foil with laminated film was heated at 100°C for 30 minutes, then at 180°C for 30 minutes, and then at 110°C for 60 minutes to harden the resin film in the laminated film. After peeling the PET film from the cured resin film, the glass cloth tape attached to the four sides was removed. Next, the midpoints of the two long sides of the copper foil were fixed with glass cloth tape, and the heights of the four points were measured. The average value of these measurements was taken as the amount of warping.

[0195] [Criteria for determining warpage of cured material] ○○: Warpage of 10 mm or less ○: Warpage exceeding 10 mm but 20 mm or less ×: Warpage exceeding 20 mm

[0196] (3) Adhesion between the insulating layer and the metal layer (peel strength) Lamination process: A double-sided copper-clad laminate (copper foil thickness of 18 μm on each side, substrate thickness of 0.7 mm, substrate size 100 mm x 100 mm, Hitachi Chemical Co., Ltd. "MCL-E679FG") was prepared. Both sides of the copper foil surface of this double-sided copper-clad laminate were immersed in MEC's ​​"Cz8101" to roughen the surface of the copper foil. On both sides of the roughened copper-clad laminate, the resin film (B-stage film) side of the laminated film was laminated onto the copper-clad laminate using Meiki Seisakusho's "Batch-type vacuum laminator MVLP-500-IIA" to obtain a laminated structure. The lamination conditions were to reduce the pressure to 13 hPa or less by depressurizing for 30 seconds, and then press at 100°C and a pressure of 0.7 MPa for 30 seconds.

[0197] Film peeling process: The PET films on both sides of the obtained laminated structure were peeled off.

[0198] Copper foil lamination process: The shiny surface of a copper foil (35 μm thick, manufactured by Mitsui Mining & Smelting Co., Ltd.) was treated with Cz (Cz8101, manufactured by MEC Corporation) to etch the copper foil surface to a depth of approximately 1 μm. The etched copper foil was then bonded to the laminated structure from which the PET film had been peeled off to obtain a copper foil-covered substrate. The obtained copper foil-covered substrate was heat-treated in a gear oven at 200°C for 60 minutes to obtain an evaluation sample.

[0199] Measurement of peel strength: A 1 cm wide strip-shaped cut was made on the surface of the copper foil of the evaluation sample. The evaluation sample was placed in a 90° peel tester (TE-3001, manufactured by Tester Sangyo Co., Ltd.), and the end of the cut copper foil was picked up with a gripper, and the copper foil was peeled off by 20 mm to measure the peel strength.

[0200] [Criteria for determining peel strength] ○: Peel strength is 0.50 kgf or higher ×: Peel strength is less than 0.50 kgf

[0201] The composition and results are shown in Tables 1 to 4 below. Table 1 contains detailed information on the ingredients listed in Tables 2 to 4. Further details of the ingredients listed in Table 1 are as described above.

[0202]

[0203]

[0204]

[0205]

[0206] 11...Multilayer printed circuit board 12...Circuit board 12a...Top surface 13-16...Insulating layer 17...Metal layer

Claims

1. A resin material comprising a curable compound A, a curing agent B, and a thermoplastic resin C, wherein the thermoplastic resin C comprises a thermoplastic resin C1 having a softening point of 120°C or higher and a polyimide resin C2 having a softening point of 110°C or lower.

2. The resin material according to claim 1, wherein the polyimide resin C2 is a reaction product of tetracarboxylic acid and dimeramine.

3. The resin material according to claim 1 or 2, wherein the content of the polyimide resin C2 in 100% by weight of the thermoplastic resin C is 1% by weight or more and 55% by weight or less.

4. The resin material according to any one of claims 1 to 3, wherein the thermoplastic resin C1 is a polyimide resin.

5. The resin material according to any one of claims 1 to 4, wherein the curable compound A is a thermosetting compound.

6. The resin material according to any one of claims 1 to 5, wherein the curable compound A comprises an epoxy compound.

7. The resin material according to any one of claims 1 to 6, wherein the curing agent B comprises an active ester compound.

8. The resin material according to any one of claims 1 to 7, further comprising an inorganic filler D.

9. The resin material according to claim 8, wherein the content of the inorganic filler D is 50% by weight or more of 100% by weight of the components excluding the solvent in the resin material.

10. The resin material according to any one of claims 1 to 9, wherein when the resin material is heated at 190°C for 90 minutes to obtain a cured product of the resin material, the dielectric loss tangent of the obtained cured product is 0.004 or less.

11. A resin material according to any one of claims 1 to 10, which is a resin film.

12. A resin material according to any one of claims 1 to 11, used for forming an insulating layer in a multilayer printed circuit board.

13. A cured product of a resin material, wherein the resin material is the resin material described in any one of claims 1 to 12.

14. A multilayer printed circuit board comprising a circuit board, a plurality of insulating layers disposed on the surface of the circuit board, and a metal layer disposed between the plurality of insulating layers, wherein at least one of the plurality of insulating layers is a cured product of the resin material described in any one of claims 1 to 12.

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