JP7474064B2 - Resin materials and multilayer printed wiring boards - Google Patents

Description

The present invention relates to a resin material containing a maleimide compound. The present invention also relates to a multilayer printed wiring board using the resin material.

Conventionally, various resin materials have been used to obtain electronic components such as semiconductor devices, laminates, and printed wiring boards. For example, in multilayer printed wiring boards, resin materials are used to form insulating layers for insulating between internal layers, and to form insulating layers located on the surface. Wiring, which is generally metal, is laminated on the surface of the insulating layer. In addition, resin films in which the resin materials are filmized may be used to form the insulating layers. The resin materials and resin films are used as insulating materials for multilayer printed wiring boards, including build-up films.

The following Patent Document 1 discloses a resin composition containing a compound having a maleimide group, a divalent group having at least two imide bonds, and a saturated or unsaturated divalent hydrocarbon group. Patent Document 1 also describes that a cured product of this resin composition can be used as an insulating layer for a multilayer printed wiring board or the like.

The following Patent Document 2 discloses a resin composition for electronic materials that contains a bismaleimide compound having two maleimide groups and one or more polyimide groups having a specific structure. In the bismaleimide compound, the two maleimide groups are each independently bonded to both ends of the polyimide group via at least a first linking group in which eight or more atoms are linearly linked.

In addition, the following Patent Document 3 discloses a cured body of a resin composition containing an epoxy compound, a curing agent, an inorganic filler, and a polyimide. The content of the inorganic filler is 30% by weight or more and 90% by weight or less in 100% by weight of the cured body. The cured body has a sea-island structure having a sea portion and an island portion, the average major axis of the island portion is 5 μm or less, and the island portion contains the polyimide.

WO2016/114286A1 JP 2018-90728 A WO2018/062405A1

When an insulating layer is formed using conventional resin materials such as those described in Patent Documents 1 to 3, the dielectric tangent of the cured product may not be sufficiently low, or the thermal dimensional stability may not be sufficiently high.

In addition, when an insulating layer is formed using conventional resin materials, the elongation properties of the cured product may not be sufficiently high, the bending properties of the cured product may not be sufficiently high, and the peel strength between the metal layer and the insulating layer may not be sufficiently high.

The object of the present invention is to provide a resin material that, in a cured product thereof, 1) can lower the dielectric tangent, 2) can increase the thermal dimensional stability, 3) can increase the elongation characteristics, 4) can increase the bending characteristics, and 5) can increase the peel strength against the metal layer. Another object of the present invention is to provide a multilayer printed wiring board using the above-mentioned resin material.

According to a broad aspect of the present invention, a resin material is provided that includes a thermosetting compound and an imide skeleton-containing maleimide compound that has one or more maleimide skeletons and two or more imide skeletons and has at least one functional group that can react with the thermosetting compound.

In a particular aspect of the resin material according to the present invention, the imide skeleton-containing maleimide compound has two or more maleimide skeletons and has the maleimide skeleton at a terminal.

In a particular aspect of the resin material according to the present invention, the thermosetting compound is a maleimide compound, an epoxy compound, a vinyl compound, or a benzoxazine compound.

In a particular aspect of the resin material according to the present invention, the functional group in the imide skeleton-containing maleimide compound that can react with the thermosetting compound is a vinyl group, a phenolic hydroxyl group, or an active ester group.

In a particular aspect of the resin material according to the present invention, the imide skeleton-containing maleimide compound has a skeleton derived from a dimer triamine or a skeleton derived from a trimer triamine.

In a particular aspect of the resin material according to the present invention, the imide skeleton-containing maleimide compound has a skeleton derived from dimer diamine.

In a particular aspect of the resin material according to the present invention, in the imide skeleton-containing maleimide compound, the skeleton derived from the dimer diamine is directly bonded to the maleimide skeleton.

In a particular aspect of the resin material according to the present invention, the imide skeleton-containing maleimide compound has a skeleton derived from a reaction product of a diamine compound other than dimer diamine and an acid dianhydride.

In a particular aspect of the resin material according to the present invention, the molecular weight of the imide skeleton-containing maleimide compound is 1,000 or more and 50,000 or less.

In a particular aspect of the resin material according to the present invention, the resin material contains an inorganic filler.

In a particular aspect of the resin material according to the present invention, the resin material includes a hardener.

In a particular aspect of the resin material according to the present invention, at least one of the thermosetting compound and the curing agent has an amide bond or an imide bond.

In a particular aspect of the resin material according to the present invention, the thermosetting compound includes an epoxy compound, and the curing agent includes at least one component selected from the group consisting of a phenol compound, an active ester compound, a cyanate ester compound, and a carbodiimide compound.

In a particular aspect of the resin material according to the present invention, the curing agent contains a phenol compound and an active ester compound.

In a particular aspect of the resin material according to the present invention, the thermosetting compound has an amide bond or an imide bond.

In a particular aspect of the resin material according to the present invention, the resin material is a resin film.

The resin material according to the present invention is suitable for use in forming insulating layers in multilayer printed wiring boards.

According to a broad aspect of the present invention, there is provided a multilayer printed wiring board comprising a circuit board, a plurality of insulating layers disposed on a surface of the circuit board, and a metal layer disposed between the plurality of insulating layers, at least one of the plurality of insulating layers being a cured product of the above-mentioned resin material.

The resin material according to the present invention includes a thermosetting compound and an imide skeleton-containing maleimide compound having one or more maleimide skeletons and two or more imide skeletons, and having at least one functional group capable of reacting with the thermosetting compound. The resin material according to the present invention has the above-mentioned configuration, and therefore, in a cured product of the resin material, it is possible to achieve all of the effects 1) to 5), namely, 1) a low dielectric tangent, 2) improved thermal dimensional stability, 3) improved elongation properties, 4) improved bending properties, and 5) improved peel strength against a metal layer.

FIG. 1 is a cross-sectional view showing a multilayer printed wiring board using a resin material according to one embodiment of the present invention.

The present invention is described in detail below.

The resin material according to the present invention includes a thermosetting compound and an imide skeleton-containing maleimide compound that has one or more maleimide skeletons and two or more imide skeletons and has at least one functional group that can react with the thermosetting compound.

Therefore, the resin material according to the present invention contains a thermosetting compound and a maleimide compound containing an imide skeleton.

The resin material according to the present invention has the above-mentioned configuration, and therefore, in the cured product of the resin material, it is possible to achieve all of the following effects 1) to 5): 1) a lower dielectric tangent, 2) improved thermal dimensional stability, 3) improved elongation properties, 4) improved bending properties, and 5) improved peel strength against the metal layer.

In addition, since the resin material according to the present invention has the above-mentioned configuration, smears can be effectively removed by desmearing.

In addition, since the resin material according to the present invention has the above-mentioned configuration, the glass transition temperature of the cured product can be increased. Increasing the glass transition temperature is preferable in terms of improving reliability in thermal cycle tests.

The resin material according to the present invention may be a resin composition or a resin film. The resin composition has fluidity. The resin composition may be in a paste form. The paste form includes a liquid form. Since the resin material according to the present invention has excellent handleability, it is preferable that the resin material is a resin film.

The resin material according to the present invention is preferably a thermosetting material. When the resin material is a resin film, the resin film is preferably a thermosetting resin film.

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

[Thermosetting compound]
The resin material includes a thermosetting compound. The thermosetting compound has one or more maleimide skeletons and two or more imide skeletons, and is a thermosetting compound different from the maleimide compound having at least one functional group capable of reacting with the thermosetting compound. The thermosetting compound is a thermosetting compound different from the imide skeleton-containing maleimide compound. Only one type of the thermosetting compound may be used, or two or more types may be used in combination.

The above-mentioned thermosetting compounds include styrene compounds, phenoxy compounds, oxetane compounds, maleimide compounds, epoxy 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.

The thermosetting compound is preferably a maleimide compound, an epoxy compound, a vinyl compound, or a benzoxazine compound, more preferably contains an epoxy compound or a vinyl compound, and even more preferably contains an epoxy compound. In this case, the dielectric tangent of the cured product can be further lowered and the thermal dimensional stability of the cured product can be further improved.

At least one of the thermosetting compound and the curing agent described later preferably has an amide bond or an imide bond. The thermosetting compound preferably has an amide bond or an imide bond. The curing agent preferably has an amide bond or an imide bond. Both the thermosetting compound and the curing agent preferably have an amide bond or an imide bond. By using a thermosetting compound having an amide bond or an imide bond, the compatibility between the thermosetting compound and the maleimide compound can be increased, and the desmearing property can be further improved. By using a curing agent having an amide bond or an imide bond, the compatibility between the curing agent and the maleimide compound can be increased, and the desmearing property can be further improved. The thermosetting compound and the curing agent may each have an amide bond or an imide bond. It is particularly preferable that the resin material contains an epoxy compound having an amide bond or an imide bond.

<Maleimide Compound>
The maleimide compound is a maleimide compound (hereinafter, sometimes referred to as "maleimide compound X") that has one or more maleimide skeletons and two or more imide skeletons and is different from a maleimide compound having at least one functional group capable of reacting with the thermosetting compound. The maleimide compound X is a maleimide compound that is different from the imide skeleton-containing maleimide compound. Only one type of maleimide compound X may be used, or two or more types may be used in combination.

The maleimide compound X may be a bismaleimide compound.

Examples of the maleimide compound X include N-phenylmaleimide and N-alkylbismaleimide.

It is preferable that the maleimide compound X has a skeleton derived from a diamine compound other than a dimer diamine or a triamine compound other than a trimer triamine.

The maleimide compound X preferably has an aromatic skeleton.

In the maleimide compound X, it is preferable that the nitrogen atom in the maleimide skeleton is bonded to an aromatic ring.

From the viewpoint of further enhancing the thermal dimensional stability of the cured product, the content of the maleimide compound X is preferably 1% by weight or more, more preferably 3% by weight or more, and preferably 20% by weight or less, more preferably 10% by weight or less, based on 100% by weight of the components excluding the solvent in the resin material.

The content of the maleimide compound X in 100% by weight of the components in the resin material excluding the inorganic filler and the solvent is preferably 2.5% by weight or more, more preferably 5% by weight or more, even more preferably 10% by weight or more, preferably 60% by weight or less, and more preferably 35% by weight or less. When the content of the maleimide compound X is equal to or more than the lower limit and equal to or less than the upper limit, the thermal dimensional stability of the cured product can be further improved.

From the viewpoint of effectively exerting the effects of the present invention, the molecular weight of the maleimide compound X is preferably 500 or more, more preferably 1000 or more, and preferably less than 60000, more preferably less than 30000.

When the maleimide compound X is not a polymer and when the structural formula of the maleimide compound X can be specified, the molecular weight of the maleimide compound X means the molecular weight that can be calculated from the structural formula. When the maleimide compound X is a polymer, the molecular weight of the maleimide compound X means the weight average molecular weight in terms of polystyrene measured by gel permeation chromatography (GPC).

Commercially available examples of the maleimide compound X include "BMI4000" and "BMI5100" manufactured by Daiwa Chemical Industry Co., Ltd., "BMI-3000" manufactured by Designer Molecules Inc., and "MIR-3000" manufactured by Nippon Kayaku Co., Ltd.

<Epoxy Compound>
As the epoxy compound, a conventionally known epoxy compound can be used. The epoxy compound is an organic compound having at least one epoxy group. The epoxy compound may be used alone or in combination of two or more kinds.

The above epoxy compounds include bisphenol A type epoxy compounds, bisphenol F type epoxy compounds, bisphenol S type epoxy compounds, phenol novolac type epoxy compounds, biphenyl type epoxy compounds, biphenyl novolac type epoxy compounds, biphenol 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.

The epoxy compound may be a glycidyl ether compound. The glycidyl ether compound is a compound having at least one glycidyl ether group.

From the viewpoint of further lowering the dielectric tangent and improving the thermal dimensional stability and flame retardancy of the cured product, the above epoxy compound preferably contains an epoxy compound having an aromatic skeleton, preferably contains an epoxy compound having a naphthalene skeleton or a phenyl skeleton, and more preferably is an epoxy compound having an aromatic skeleton.

From the viewpoint of further lowering the dielectric tangent and improving the coefficient of linear expansion (CTE) of the cured product, it is preferable that the epoxy compound contains an epoxy compound that is liquid at 25°C and an epoxy compound that is solid at 25°C.

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

The viscosity of the epoxy compound can be measured, for example, using a dynamic viscoelasticity measuring device ("VAR-100" manufactured by Rheologica Instruments).

It is more preferable that the molecular weight of the epoxy compound is 1000 or less. In this case, even if the content of the inorganic filler is 50% by weight or more out of 100% by weight of the components excluding the solvent in the resin material, a resin material with high fluidity can be obtained when forming the insulating layer. Therefore, when the uncured or B-staged resin material is laminated onto a circuit board, the inorganic filler can be uniformly present.

When the epoxy compound is not a polymer and when the structural formula of the epoxy compound can be specified, the molecular weight of the epoxy compound refers to the molecular weight that can be calculated from the structural formula. When the epoxy compound is a polymer, the molecular weight refers to the weight average molecular weight.

From the viewpoint of further improving the thermal dimensional stability of the cured product, the content of the above epoxy compound is preferably 15% by weight or more, more preferably 25% by weight or more, preferably 50% by weight or less, more preferably 40% by weight or less, based on 100% by weight of the components in the resin material excluding the inorganic filler and the solvent.

The content of the epoxy compound is preferably 5% by weight or more, more preferably 7% by weight or more, and preferably 15% by weight or less, more preferably 12% by weight or less, based on 100% by weight of the components in the resin material excluding the solvent. When the content of the epoxy compound is equal to or more than the lower limit, the thermal dimensional stability of the cured product can be further improved. When the content of the epoxy compound is equal to or less than the upper limit, the dielectric tangent of the cured product can be further reduced.

The weight ratio of the content of the epoxy compound to the total content of the imide skeleton-containing maleimide compound, the phenol compound, and the active ester compound described below (epoxy compound content/total content of the imide skeleton-containing maleimide compound, the phenol compound, and the active ester compound described below) is preferably 0.1 or more, more preferably 0.3 or more. The weight ratio of the content of the epoxy compound to the total content of the imide skeleton-containing maleimide compound, the phenol compound, and the active ester compound described below (epoxy compound content/total content of the imide skeleton-containing maleimide compound, the phenol compound, and the active ester compound) is preferably 0.9 or less, more preferably 0.8 or less. When the weight ratio is equal to or more than the lower limit and equal to or less than the upper limit, the dielectric tangent can be further lowered and the thermal dimensional stability can be further improved.

<Vinyl Compounds>
As the vinyl compound, a conventionally known vinyl compound can be used. The vinyl compound is an organic compound having at least one vinyl group. The vinyl compound may be used alone or in combination of two or more kinds.

Examples of the vinyl compounds include divinylbenzyl ether compounds.

The content of the vinyl compound is preferably 5% by weight or more, more preferably 10% by weight or more, and preferably 80% by weight or less, more preferably 70% by weight or less, based on 100% by weight of the components in the resin material excluding the inorganic filler and the solvent. When the content of the vinyl compound is equal to or more than the lower limit and equal to or less than the upper limit, the thermal dimensional stability of the cured product can be further improved.

<Benzoxazine Compound>
Examples of the benzoxazine compound include Pd type benzoxazine and Fa type benzoxazine.

Commercially available products of the above benzoxazine compounds include "P-d type" manufactured by Shikoku Chemical Industry Co., Ltd.

The content of the benzoxazine compound in the resin material (100% by weight, excluding inorganic fillers and solvents) is preferably 1% by weight or more, more preferably 5% by weight or more, even more preferably 10% by weight or more, preferably 70% by weight or less, and more preferably 60% by weight or less. When the content of the benzoxazine compound is equal to or more than the lower limit and equal to or less than the upper limit, the thermal dimensional stability of the cured product can be further improved.

[Maleimide compound containing an imide skeleton]
The resin material according to the present invention includes an imide skeleton-containing maleimide compound. The imide skeleton-containing maleimide compound is a maleimide compound having one or more maleimide skeletons and two or more imide skeletons, and having at least one functional group capable of reacting with the thermosetting compound. The imide skeleton-containing maleimide compound has one or more maleimide skeletons and two or more imide skeletons. The maleimide skeleton and the imide skeleton each exist as a partial skeleton in the imide skeleton-containing maleimide compound. Only one type of the imide skeleton-containing maleimide compound may be used, or two or more types may be used in combination.

The above imide skeleton-containing maleimide compound is a thermosetting compound.

In order to achieve all of the above effects 1) to 5), the number of the maleimide skeletons in the imide skeleton-containing maleimide compound is 1 or more.

The number of the maleimide skeletons in the imide skeleton-containing maleimide compound is preferably 2 or more, preferably 25 or less, more preferably 10 or less, and even more preferably 5 or less. When the number of the maleimide skeletons is equal to or more than the lower limit and equal to or less than the upper limit, the dielectric tangent of the cured product can be further reduced, and the thermal dimensional stability of the cured product can be further improved. The number of the maleimide skeletons in the imide skeleton-containing maleimide compound may be 1.

The imide skeleton-containing maleimide compound preferably has two or more maleimide skeletons and has the maleimide skeleton at the terminal. The imide skeleton-containing maleimide compound preferably has the maleimide skeleton at both terminals of the main chain.

In order to achieve all of the above effects 1) to 5), the number of imide skeletons in the imide skeleton-containing maleimide compound is two or more.

The number of the imide skeletons in the imide skeleton-containing maleimide compound is preferably 3 or more, preferably 25 or less, and more preferably 15 or less. When the number of the imide skeletons is equal to or more than the lower limit and equal to or less than the upper limit, the dielectric tangent of the cured product can be further reduced, and the thermal dimensional stability of the cured product can be further improved. The number of the imide skeletons in the imide skeleton-containing maleimide compound may be 2.

In the above imide skeleton-containing maleimide compound, the number of the maleimide skeletons and the number of the imide skeletons may be the same or different.

From the viewpoint of further lowering the dielectric tangent of the cured product and further increasing the thermal dimensional stability of the cured product, it is preferable that the number of the maleimide skeletons in the imide skeleton-containing maleimide compound is the same as the number of the imide skeletons, or that the number of the imide skeletons is greater than the number of the maleimide skeletons.

From the viewpoint of smoothly progressing the curing reaction, lowering the dielectric tangent of the cured product, and increasing the thermal dimensional stability of the cured product, it is preferable that the imide skeleton-containing maleimide compound has at least one functional group capable of reacting with the thermosetting compound in the skeleton located between the multiple imide skeletons.

The functional group in the imide skeleton-containing maleimide compound that can react with the thermosetting compound is preferably a vinyl group, a phenolic hydroxyl group, or an active ester group, and more preferably a phenolic hydroxyl group. When the resin material contains an epoxy compound, the use of a compound having a phenolic hydroxyl group may facilitate the curing reaction to proceed sufficiently.

The active ester group is, for example, a group represented by the following formula (10A):

In the above formula (10A), R1 represents an aliphatic chain, an aliphatic ring, or an aromatic ring, and R2 represents an aromatic ring.

When the thermosetting compound is the maleimide compound X, the functional group in the imide skeleton-containing maleimide compound capable of reacting with the thermosetting compound is preferably a vinyl group or a benzoxazine group.

When the thermosetting compound is the epoxy compound, the functional group in the imide skeleton-containing maleimide compound that can react with the thermosetting compound is preferably a phenolic hydroxyl group, an active ester group, or a benzoxazine group. The functional group in the imide skeleton-containing maleimide compound that can react with the thermosetting compound may be a phenolic hydroxyl group or a benzoxazine group.

When the thermosetting compound is a vinyl compound, the functional group in the imide skeleton-containing maleimide compound that can react with the thermosetting compound is preferably a vinyl group.

The number of functional groups in the imide skeleton-containing maleimide compound that can react with the thermosetting compound is preferably 1 or more, more preferably 2 or more, and preferably 15 or less, more preferably 10 or less.

The imide skeleton-containing maleimide compound preferably has a skeleton derived from a dimer diamine or a skeleton derived from a trimer triamine, and more preferably has a skeleton derived from a dimer diamine. The skeleton derived from the dimer diamine or the skeleton derived from the trimer triamine is a flexible skeleton. Therefore, when the imide skeleton-containing maleimide compound has a skeleton derived from the dimer diamine or the skeleton derived from the trimer triamine, the reactivity of the maleimide group can be increased and the curing reaction can be sufficiently advanced. As a result, the thermal dimensional stability of the cured product can be further improved, and the adhesion between the insulating layer and the metal layer can be further improved.

From the viewpoint of further increasing the thermal dimensional stability of the cured product and further increasing the adhesion between the insulating layer and the metal layer, the number of skeletons derived from the dimer diamine in the imide skeleton-containing maleimide compound is preferably 1 or more, more preferably 2 or more, and preferably 25 or less, more preferably 10 or less.

From the viewpoint of further enhancing the thermal dimensional stability of the cured product, in the above imide skeleton-containing maleimide compound, the proportion of the skeleton derived from the above dimer diamine out of 100 mol % of skeletons derived from all diamine compounds is preferably 10 mol % or more, more preferably 20 mol % or more, preferably 50 mol % or less, more preferably 40 mol % or less.

In the imide skeleton-containing maleimide compound, the skeleton derived from the dimer diamine is preferably directly bonded to the maleimide skeleton at the end of the imide skeleton-containing maleimide compound. More specifically, one of the nitrogen atoms in the skeleton derived from the dimer diamine is preferably a nitrogen atom in the maleimide skeleton at the end. In this case, the reactivity of the maleimide group can be further increased, and the curing reaction can be sufficiently promoted. As a result, the thermal dimensional stability of the cured product can be further increased, and the adhesion between the insulating layer and the metal layer can be further increased.

In the imide skeleton-containing maleimide compound, all of the maleimide skeletons may or may not be directly bonded to the skeleton derived from the dimer diamine.

The number of the maleimide skeletons in the imide skeleton-containing maleimide compound and the number of skeletons derived from the dimer diamine may be the same or different.

From the viewpoint of further improving the thermal dimensional stability of the cured product, it is preferable that the number of imide skeletons in the imide skeleton-containing maleimide compound is smaller than the number of skeletons derived from the dimer diamine.

In the imide skeleton-containing maleimide compound, the skeleton derived from the trimer triamine is preferably directly bonded to the maleimide skeleton of the imide skeleton-containing maleimide compound. More specifically, one of the nitrogen atoms in the skeleton derived from the trimer triamine is preferably a nitrogen atom in the maleimide skeleton at the terminal. In this case, the reactivity of the maleimide group can be further increased, and the curing reaction can be sufficiently advanced. As a result, the thermal dimensional stability of the cured product can be further increased, and the adhesion between the insulating layer and the metal layer can be further increased.

In the imide skeleton-containing maleimide compound, all of the maleimide skeletons do not have to be directly bonded to the skeleton derived from the trimer triamine.

The number of the maleimide skeletons in the imide skeleton-containing maleimide compound and the number of skeletons derived from the trimer triamine may be the same or different.

From the viewpoint of further enhancing the thermal dimensional stability of the cured product, it is preferable that the number of the imide skeletons in the imide skeleton-containing maleimide compound is the same as the number of skeletons derived from the trimer triamine, or that the number of the imide skeletons is greater than the number of skeletons derived from the trimer triamine.

The imide skeleton-containing maleimide compound may have a skeleton derived from a diamine compound other than the dimer diamine, or may have a skeleton derived from a triamine compound other than the trimer triamine.

From the viewpoint of effectively exerting the effects of the present invention, it is preferable that the imide skeleton-containing maleimide compound has a skeleton derived from a reaction product of dimer diamine and acid dianhydride. The skeleton derived from the reaction product of dimer diamine and acid dianhydride has a skeleton derived from the dimer diamine.

From the viewpoint of effectively exerting the effects of the present invention, it is preferable that the imide skeleton-containing maleimide compound has a skeleton derived from a reaction product of a diamine compound other than the dimer diamine and an acid dianhydride. The skeleton derived from a reaction product of a diamine compound other than the dimer diamine and an acid dianhydride has a skeleton derived from a diamine compound other than the dimer diamine.

The imide skeleton-containing maleimide compound preferably has the functional group capable of reacting with the thermosetting compound in the skeleton derived from the reaction product of the diamine other than the dimer diamine and the acid dianhydride.

The functional group capable of reacting with the thermosetting compound may be a group derived from at least one of a diamine and an acid dianhydride.

The above imide skeleton-containing maleimide compound can be synthesized, for example, as follows.

An acid dianhydride such as tetracarboxylic dianhydride, dimer diamine, and 2,2-bis(3-amino-4-hydroxyphenyl)propane are reacted to obtain a first reactant. The obtained first reactant is reacted with maleic anhydride.

Examples of the tetracarboxylic dianhydride include pyromellitic dianhydride, 3,3',4,4'-benzophenone tetracarboxylic dianhydride, 3,3',4,4'-biphenylsulfone tetracarboxylic dianhydride, 1,4,5,8-naphthalene tetracarboxylic dianhydride, 2,3,6,7-naphthalene tetracarboxylic dianhydride, 3,3',4,4'-biphenyl ether tetracarboxylic dianhydride, 3,3',4,4'-dimethyldiphenylsilane tetracarboxylic dianhydride, 3,3',4,4'-tetraphenylsilane tetracarboxylic dianhydride, 1,2,3,4-furan tetracarboxylic dianhydride, 4,4'-bis(3,4-dicarboxyphenoxy)diphenylsulfonyl tetracarboxylic dianhydride, and 4,4'-bis(3,4-dicarboxyphenoxy)diphenylsulfonyl tetracarboxylic dianhydride. dianhydride, 4,4'-bis(3,4-dicarboxyphenoxy)diphenylsulfone dianhydride, 4,4'-bis(3,4-dicarboxyphenoxy)diphenylpropane dianhydride, 3,3',4,4'-perfluoroisopropylidenediphthalic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, bis(phthalic acid)phenylphosphine oxide dianhydride, p-phenylene-bis(triphenylphthalic acid) dianhydride, m-phenylene-bis(triphenylphthalic acid) dianhydride, bis(triphenylphthalic acid)-4,4'-diphenyl ether dianhydride, and bis(triphenylphthalic acid)-4,4'-diphenylmethane dianhydride are examples of such anhydrides.

Examples of the dimer diamine include VERSAMINE 551 (product name, manufactured by BASF Japan, 3,4-bis(1-aminoheptyl)-6-hexyl-5-(1-octenyl)cyclohexene), VERSAMINE 552 (product name, manufactured by Cognix Japan, hydrogenated VERSAMINE 551), and PRIAMINE 1075 and PRIAMINE 1074 (product names, both manufactured by Croda Japan).

An example of the trimer triamine is PRIAMINE 1071 (product name, manufactured by Croda Japan). However, since PRIAMINE 1071 contains approximately 20% to 25% by mass of triamine components, it is necessary to take the ratio into consideration when using it in the reaction.

Diamine compounds other than the above dimer diamines include 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, bis(aminomethyl)norbornane, 3(4),8(9)-bis(aminomethyl)tricyclo[5.2.1.02,6]decane, 1,1-bis(4-aminophenyl)cyclohexane, 1,3-cyclohexanediamine, 1,4-cyclohexanediamine, 2,7-diaminofluorene, 4,4'-ethylenedianiline, isophoronediamine, 4,4'-methylenebis(cyclohe xylamine), 4,4'-methylenebis(2,6-diethylaniline), 4,4'-methylenebis(2-ethyl-6-methylaniline), 4,4'-methylenebis(2-methylcyclohexylamine), 1,4-diaminobutane, 1,10-diaminodecane, 1,12-diaminododecane, 1,7-diaminoheptane, 1,6-diaminohexane, 1,5-diaminopentane, 1,8-diaminooctane, 1,3-diaminopropane, 1,11-diaminoundecane, and 2-methyl-1,5-diaminopentane.

An example of a triamine compound other than the above trimer triamine is tris(2-aminoethyl)amine (manufactured by Tokyo Chemical Industry Co., Ltd.).

The skeleton derived from the dimer diamine may or may not have an aliphatic ring. The skeleton derived from the dimer diamine may or may not have an aliphatic ring.

The skeleton derived from the diamine compound other than the dimer diamine may or may not have an aromatic ring. The skeleton derived from the diamine compound other than the dimer diamine may or may not have an aromatic ring.

The skeleton derived from the diamine compound other than the dimer diamine may or may not have an aliphatic ring. The skeleton derived from the diamine compound other than the dimer diamine may or may not have an aliphatic ring.

The aromatic rings include a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a tetracene ring, a chrysene ring, a triphenylene ring, a tetraphene ring, a pyrene ring, a pentacene ring, a picene ring, and a perylene ring.

Examples of the aliphatic ring include a monocycloalkane ring, a bicycloalkane ring, a tricycloalkane ring, a tetracycloalkane ring, and a dicyclopentadiene ring.

The molecular weight of the imide skeleton-containing maleimide compound is preferably 1000 or more, more preferably 5000 or more, even more preferably more than 5000, particularly preferably 7500 or more, most preferably 8000 or more, preferably 50000 or less, more preferably 25000 or less, even more preferably 18000 or less, and particularly preferably 15000 or less. When the molecular weight of the imide skeleton-containing maleimide compound is equal to or greater than the lower limit, the linear expansion coefficient of the cured product can be kept low. In addition, when the molecular weight of the imide skeleton-containing maleimide compound exceeds 50000, the melt viscosity of the resin material becomes higher than when the molecular weight of the imide skeleton-containing maleimide compound is 50000 or less, and the embeddability of the resin material in the uneven surface may decrease. It is particularly preferable that the molecular weight of the imide skeleton-containing maleimide compound is 1000 or more and 50000 or less.

The molecular weight of the imide skeleton-containing maleimide compound means the molecular weight that can be calculated from the structural formula when the imide skeleton-containing maleimide compound is not a polymer and when the structural formula of the imide skeleton-containing maleimide compound can be specified. In addition, when the imide skeleton-containing maleimide compound is a polymer, the molecular weight of the imide skeleton-containing maleimide compound indicates the weight average molecular weight in terms of polystyrene measured by gel permeation chromatography (GPC).

From the viewpoint of further increasing the thermal dimensional stability of the cured product and further increasing the adhesion between the insulating layer and the metal layer, the softening point of the imide skeleton-containing maleimide compound is preferably 70°C or higher, more preferably 100°C or higher.

The softening point can be determined from the inflection point of the reverse heat flow by heating from -30°C to 260°C at a heating rate of 3°C/min in a nitrogen atmosphere using a differential scanning calorimeter (e.g., TA Instruments' Q2000).

The content of the imide skeleton-containing maleimide compound in 100% by weight of the components in the resin material excluding the inorganic filler and the solvent is preferably 5% by weight or more, more preferably 10% by weight or more, even more preferably 15% by weight or more, preferably 80% by weight or less, more preferably 70% by weight or less. When the content of the imide skeleton-containing maleimide compound is equal to or more than the lower limit, the dielectric tangent of the cured product can be lowered and the adhesion between the insulating layer and the metal layer can be further improved, and the surface roughness after etching can be further reduced. When the content of the imide skeleton-containing maleimide compound is equal to or less than the upper limit, the melt viscosity can be lowered and the thermal dimensional stability of the cured product can be further improved.

[Inorganic filler]
The resin material preferably contains an inorganic filler. By using the inorganic filler, the dielectric tangent of the cured product can be further reduced. In addition, by using the inorganic filler, the dimensional change of the cured product due to heat can be further reduced. The inorganic filler may be used alone or in combination of two or more kinds.

Examples of the inorganic fillers include silica, talc, clay, mica, hydrotalcite, alumina, magnesium oxide, aluminum hydroxide, aluminum nitride, and boron nitride.

From the viewpoint of reducing the surface roughness of the cured product, further increasing the adhesive strength between the cured product and the metal layer, forming finer wiring on the surface of the cured product, and imparting better insulation reliability to the cured product, the inorganic filler is preferably silica or alumina, more preferably silica, and even more preferably fused silica. By using silica, the thermal expansion coefficient of the cured product is further reduced, and the dielectric tangent of the cured product is further reduced. In addition, by using silica, 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. The silica is preferably spherical in shape.

From the viewpoint of promoting resin curing regardless of the curing environment, effectively increasing the glass transition temperature of the cured product, and effectively reducing the coefficient of linear thermal expansion of the cured product, it is preferable that the inorganic filler be spherical silica.

The average particle size of the inorganic filler is preferably 50 nm or more, more preferably 100 nm or more, even more preferably 500 nm or more, and 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 is equal to or greater than the lower limit and equal to or less than the upper limit, the surface roughness after etching can be reduced and the plating peel strength can be increased, and the adhesion between the insulating layer and the metal layer can be further improved.

The median diameter (d50) at 50% is used as the average particle size of the inorganic filler. The average particle size can be measured using a laser diffraction scattering particle size distribution measuring device.

The inorganic filler 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 is spherical, the aspect ratio of the inorganic filler is preferably 2 or less, and more preferably 1.5 or less.

The inorganic filler is preferably surface-treated, more preferably surface-treated with a coupling agent, and even more preferably surface-treated with a silane coupling agent. By surface-treating the inorganic filler, the surface roughness of the roughened cured product is further reduced, and the adhesive strength between the cured product and the metal layer is further increased. In addition, by surface-treating the inorganic filler, finer wiring can be formed on the surface of the cured product, and better inter-wiring insulation reliability and inter-layer insulation reliability can be imparted to the cured product.

Examples of the coupling agent include silane coupling agents, titanium coupling agents, and aluminum coupling agents. Examples of the silane coupling agent include methacrylsilane, acrylic silane, amino silane, imidazole silane, vinyl silane, and epoxy silane.

The content of the inorganic filler is preferably 50% by weight or more, more preferably 60% by weight or more, even more preferably 65% by weight or more, particularly preferably 68% by weight or more, preferably 90% by weight or less, more preferably 85% by weight or less, even more preferably 80% by weight or less, and particularly preferably 75% by weight or less, out of 100% by weight of the components in the resin material excluding the solvent. When the content of the inorganic filler is equal to or greater than the lower limit, the dielectric tangent is effectively lowered. When the content of the inorganic filler is equal to or less than the upper limit, the thermal dimensional stability is improved and the warping of the cured product can be effectively suppressed. When the content of the inorganic filler is equal to or greater than the lower limit and equal to or less than the upper limit, the surface roughness of the cured product can be further reduced, and finer wiring can be formed on the surface of the cured product. Furthermore, with this content of the inorganic filler, it is possible to lower the thermal expansion coefficient of the cured product and at the same time improve the smear removal properties.

[Curing agent]
The resin material preferably contains a curing agent. The curing agent is not particularly limited. A conventionally known curing agent can be used as the curing agent. The curing agent may be used alone or in combination of two or more kinds.

The curing agent may be a phenol compound (phenol curing agent), an active ester compound, an amine compound (amine curing agent), a thiol compound (thiol curing agent), an imidazole compound, a phosphine compound, dicyandiamide, or an acid anhydride. The curing agent preferably has a functional group capable of reacting with the epoxy group of the epoxy compound.

From the viewpoint of further improving the thermal dimensional stability, it is preferable that the curing agent contains at least one component selected from the group consisting of a phenolic compound, an active ester compound, a cyanate ester compound, a carbodiimide compound, and an acid anhydride. From the viewpoint of further improving the thermal dimensional stability, it is more preferable that the curing agent contains at least one component selected from the group consisting of a phenolic compound, an active ester compound, a cyanate ester compound, and a carbodiimide compound, and it is even more preferable that the curing agent contains both a phenolic compound and an active ester compound.

From the viewpoint of further improving thermal dimensional stability, it is preferable that the thermosetting compound contains an epoxy compound and the curing agent contains both an active ester compound and a phenol compound.

Examples of the phenolic compounds include novolac-type phenols, biphenol-type phenols, naphthalene-type phenols, dicyclopentadiene-type phenols, aralkyl-type phenols, and dicyclopentadiene-type phenols.

Commercially available products of the above phenol compounds include novolac type phenols (DIC Corporation's "TD-2091"), biphenyl novolac type phenols (Meiwa Chemical Industry Co., Ltd.'s "MEH-7851"), aralkyl type phenol compounds (Meiwa Chemical Industry Co., Ltd.'s "MEH-7800"), and phenols having an aminotriazine skeleton (DIC Corporation's "LA-1356" and "LA-3018-50P").

The above-mentioned active ester compound refers to a compound that contains at least one ester bond in the structure and has an aliphatic chain, an aliphatic ring, or an aromatic ring bonded to both sides of the ester bond. The active ester compound is 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. An example of an active ester compound is a compound represented by the following formula (1).

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

In the above formula (1), examples of the combination 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 the above formula (1), examples of the combination 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.

The active ester compound is not particularly limited. From the viewpoint of further improving the thermal dimensional stability and flame retardancy, the active ester compound is preferably an active ester compound having two or more aromatic skeletons. From the viewpoint of lowering the dielectric tangent of the cured product and improving the thermal dimensional stability of the cured product, it is more preferable that the active ester compound has a naphthalene ring in the main chain skeleton.

Commercially available products of the above active ester compounds include "HPC-8000-65T," "EXB9416-70BK," and "EXB8100-65T" manufactured by DIC Corporation.

The above cyanate ester compounds include novolac-type cyanate ester resins, bisphenol-type cyanate ester resins, and prepolymers in which these are partially trimerized. The above novolac-type cyanate ester resins include phenol novolac-type cyanate ester resins and alkylphenol-type cyanate ester resins. The above 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.

Commercially available products of the above cyanate ester compounds include phenol novolac type cyanate ester resins (PT-30 and PT-60 manufactured by Lonza Japan) and prepolymers in which bisphenol type cyanate ester resins are trimerized (BA-230S, BA-3000S, BTP-1000S, and BTP-6020S manufactured by Lonza Japan).

The content of the cyanate ester compound in 100% by weight of the components in the resin material excluding the inorganic filler and the solvent is preferably 10% by weight or more, more preferably 15% by weight or more, even more preferably 20% by weight or more, preferably 85% by weight or less, and more preferably 75% by weight or less. When the content of the cyanate ester compound is equal to or more than the lower limit and equal to or less than the upper limit, the thermal dimensional stability of the cured product can be further improved.

The carbodiimide compound is a compound having a structural unit represented by the following formula (2). In the following formula (2), the right end and the left end are bonding sites with other groups. The above carbodiimide compounds may be used alone or in combination of two or more types.

In the above formula (2), X represents an alkylene group, a group in which a substituent is bonded to an alkylene group, a cycloalkylene group, a group in which a substituent is bonded to a cycloalkylene group, an arylene group, or a group in which a substituent is bonded to an arylene group, and p represents an integer of 1 to 5. When there are multiple Xs, the multiple Xs may be the same or different.

In one preferred embodiment, at least one X is an alkylene group, a group in which a substituent is bonded to an alkylene group, a cycloalkylene group, or a group in which a substituent is bonded to a cycloalkylene group.

Commercially available products of the above 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 Inc., as well as "Stavaxol P", "Stavaxol P400", and "Hi-Kasil 510" manufactured by Rhein Chemie AG.

Examples of the acid anhydrides include tetrahydrophthalic anhydride and alkylstyrene-maleic anhydride copolymers.

Commercially available products of the above acid anhydrides include "Rikacid TDA-100" manufactured by New Japan Chemical Co., Ltd.

The total content of the active ester compound and the phenol compound relative to 100 parts by weight of the epoxy compound is preferably 70 parts by weight or more, more preferably 85 parts by weight or more, preferably 150 parts by weight or less, more preferably 120 parts by weight or less. When the total content of the active ester compound and the phenol compound is equal to or more than the lower limit and equal to or less than the upper limit, the curing property is more excellent, the thermal dimensional stability is further improved, and the volatilization of the remaining unreacted components can be further suppressed.

The total content of the imide skeleton-containing maleimide compound, the thermosetting compound, and the curing agent in the resin film (100% by weight, excluding inorganic fillers and solvents) is preferably 50% by weight or more, more preferably 60% by weight or more, and preferably 95% by weight or less, and more preferably 90% by weight or less. When the total content of the imide skeleton-containing maleimide compound, the thermosetting compound, and the curing agent is equal to or more than the lower limit and equal to or less than the upper limit, the curing property is more excellent and the thermal dimensional stability can be further improved.

[Curing accelerator]
The resin material preferably contains a curing accelerator. The use of the curing accelerator further increases the curing speed. By quickly curing the resin material, the crosslinked structure in the cured product becomes uniform, and the number of unreacted functional groups is reduced, resulting in a high crosslink density. The curing accelerator is not particularly limited, and conventionally known curing accelerators can be used. The curing accelerator may be used alone or in combination of two or more.

Examples of the curing accelerator 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 phosphorus compounds and organometallic compounds, and radical curing accelerators such as peroxides.

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, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazolium trimellitate, and 1-cyanoethyl-2-phenylimidazolium trimethylate. Examples include melitate, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-undecylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct, 2-methylimidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole, and 2-phenyl-4-methyl-5-dihydroxymethylimidazole.

Examples of the amine compounds include diethylamine, triethylamine, diethylenetetramine, triethylenetetramine, and 4,4-dimethylaminopyridine.

Examples of the phosphorus compounds include triphenylphosphine compounds.

The organometallic compounds include zinc naphthenate, cobalt naphthenate, tin octoate, cobalt octoate, cobalt bisacetylacetonate (II), and cobalt trisacetylacetonate (III).

Examples of the above peroxides include dicumyl peroxide and perhexyl 25B.

From the viewpoint of further reducing the curing temperature and effectively suppressing warping of the cured product, it is preferable that the curing accelerator contains the anionic curing accelerator, and it is more preferable that the curing accelerator contains the imidazole compound.

A peroxide curing accelerator may be used in combination with an anionic curing accelerator. In particular, when a vinyl compound and an epoxy compound are used in combination, the use of the above two types of curing accelerators may result in an even better cured product.

From the viewpoint of further reducing the curing temperature and effectively suppressing warping of the cured product, the content of the anionic curing accelerator in 100% by weight of the curing accelerator is preferably 20% by weight or more, more preferably 50% by weight or more, even more preferably 70% by weight or more, and most preferably 100% by weight (total amount). Therefore, it is most preferable that the curing accelerator is the anionic curing accelerator.

The content of the curing accelerator is not particularly limited. 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, more preferably 3% by weight or less, based on 100% by weight of the components in the resin material excluding the inorganic filler and the solvent. When the content of the curing accelerator is equal to or more than the lower limit and equal to or less than the upper limit, the resin material is cured efficiently. When the content of the curing accelerator is within a more preferred range, the storage stability of the resin material is further improved, and a better cured product is obtained.

[Thermoplastic resin]
The resin material preferably contains a thermoplastic resin. Examples of the thermoplastic resin include polyvinyl acetal resin, polyimide resin, and phenoxy resin. The thermoplastic resin may be used alone or in combination of two or more.

From the viewpoint of effectively lowering the dielectric tangent and effectively increasing the adhesion of the metal wiring regardless of the curing environment, the thermoplastic resin is preferably a phenoxy resin. The use of phenoxy resin suppresses the deterioration of the embedding ability of the resin film in holes or irregularities in the circuit board and the non-uniformity of the inorganic filler. In addition, the use of phenoxy resin improves the dispersibility of the inorganic filler because the melt viscosity can be adjusted, and the resin composition or B-stage product is less likely to wet and spread to unintended areas during the curing process.

The phenoxy resin contained in the resin material is not particularly limited. Any conventionally known phenoxy resin can be used as the phenoxy resin. Only one type of the phenoxy resin may be used, or two or more types may be used in combination.

Examples of the phenoxy resin include phenoxy resins having a skeleton such as a bisphenol A skeleton, a bisphenol F skeleton, a bisphenol S skeleton, a biphenyl skeleton, a novolac skeleton, a naphthalene skeleton, and an imide skeleton.

Commercially available products of the above phenoxy resins include, for example, "YP50", "YP55", and "YP70" manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., and "1256B40", "4250", "4256H40", "4275", "YX6954BH30", and "YX8100BH30" manufactured by Mitsubishi Chemical Corporation.

From the viewpoint of improving handling properties, plating peel strength at low roughness, and adhesion between the insulating layer and the metal layer, the thermoplastic resin is preferably a polyimide resin (polyimide compound).

From the viewpoint of improving solubility, the polyimide compound is preferably a polyimide compound obtained by reacting a tetracarboxylic dianhydride with a dimer diamine.

Examples of the tetracarboxylic dianhydride include pyromellitic dianhydride, 3,3',4,4'-benzophenone tetracarboxylic dianhydride, 3,3',4,4'-biphenylsulfone tetracarboxylic dianhydride, 1,4,5,8-naphthalene tetracarboxylic dianhydride, 2,3,6,7-naphthalene tetracarboxylic dianhydride, 3,3',4,4'-biphenyl ether tetracarboxylic dianhydride, 3,3',4,4'-dimethyldiphenylsilane tetracarboxylic dianhydride, 3,3',4,4'-tetraphenylsilane tetracarboxylic dianhydride, 1,2,3,4-furan tetracarboxylic dianhydride, 4,4'-bis(3,4-dicarboxyphenoxy)diphenylsulfonyl tetracarboxylic dianhydride, and 4,4'-bis(3,4-dicarboxyphenoxy)diphenylsulfonyl tetracarboxylic dianhydride. dianhydride, 4,4'-bis(3,4-dicarboxyphenoxy)diphenylsulfone dianhydride, 4,4'-bis(3,4-dicarboxyphenoxy)diphenylpropane dianhydride, 3,3',4,4'-perfluoroisopropylidenediphthalic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, bis(phthalic acid)phenylphosphine oxide dianhydride, p-phenylene-bis(triphenylphthalic acid) dianhydride, m-phenylene-bis(triphenylphthalic acid) dianhydride, bis(triphenylphthalic acid)-4,4'-diphenyl ether dianhydride, and bis(triphenylphthalic acid)-4,4'-diphenylmethane dianhydride are examples of such anhydride.

Examples of the dimer diamine include VERSAMINE 551 (product name, manufactured by BASF Japan, 3,4-bis(1-aminoheptyl)-6-hexyl-5-(1-octenyl)cyclohexene), VERSAMINE 552 (product name, manufactured by Cognix Japan, hydrogenated VERSAMINE 551), PRIAMINE 1075, and PRIAMINE 1074 (product names, all manufactured by Croda Japan).

The polyimide compound may have an acid anhydride structure, a maleimide structure, or a citraconic imide structure at the end. In this case, the polyimide compound can be reacted with an epoxy resin. By reacting the polyimide compound with an epoxy resin, the thermal dimensional stability of the cured product can be improved.

From the viewpoint of obtaining a resin material with even better storage stability, the weight average molecular weight of the thermoplastic resin, the polyimide resin, and the phenoxy resin is preferably 5,000 or more, more preferably 10,000 or more, and preferably 100,000 or less, more preferably 50,000 or less.

The weight average molecular weights of the thermoplastic resin, polyimide resin, and phenoxy resin are polystyrene-equivalent weight average molecular weights measured by gel permeation chromatography (GPC).

The contents of the thermoplastic resin, the polyimide resin, and the phenoxy resin are not particularly limited. In 100% by weight of the components in the resin material excluding the inorganic filler and the solvent, the content of the thermoplastic resin (when the thermoplastic resin is a polyimide resin or a phenoxy resin, the content of the polyimide resin or the phenoxy resin) is preferably 1% by weight or more, more preferably 2% by weight or more, preferably 30% by weight or less, more preferably 20% by weight or less. When the content of the thermoplastic resin is equal to or more than the lower limit and equal to or less than the upper limit, the resin material has good embedding properties in holes or irregularities in the circuit board. When the content of the thermoplastic resin is equal to or more than the lower limit, the formation of the resin film becomes easier, and a better insulating layer is obtained. When the content of the thermoplastic resin is equal to or less than the upper limit, the thermal expansion coefficient of the cured product becomes even lower. When the content of the thermoplastic resin is equal to or less than the upper limit, the surface roughness of the surface of the cured product becomes even smaller, and the adhesive strength between the cured product and the metal layer becomes even higher.

[solvent]
The resin material does not contain or contains a solvent. By using the solvent, the viscosity of the resin material can be controlled within a suitable range, and the coatability of the resin material can be improved. The solvent may be used to obtain a slurry containing the inorganic filler. Only one type of the solvent may be used, or two or more types may be used in combination.

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.

It is preferable that most of the solvent is removed when the resin composition is formed into a film. Therefore, the boiling point of the solvent is preferably 200°C or less, more preferably 180°C or less. The content of the solvent in the resin composition is not particularly limited. The content of the solvent can be changed as appropriate, taking into account the coatability of the resin composition, etc.

When the resin material is a B-stage film, the content of the 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 10% by weight or less, more preferably 5% by weight or less.

[Other ingredients]
For the purpose of improving impact resistance, heat resistance, resin compatibility, workability, and the like, the resin material may contain an organic filler, a leveling agent, a flame retardant, a coupling agent, a colorant, an antioxidant, an ultraviolet degradation inhibitor, a defoaming agent, a thickener, a thixotropy imparting agent, and the like.

The organic filler may be a particulate material made of benzoxazine resin, benzoxazole resin, fluororesin, acrylic resin, styrene resin, or the like. By using fluororesin particles as the organic filler, the dielectric constant of the cured product can be further reduced. The average particle size of the organic filler is preferably 1 μm or less. If the average particle size of the organic filler is equal to or less than the upper limit, the surface roughness after etching can be reduced and the plating peel strength can be increased, and the adhesion between the insulating layer and the metal layer can be further improved. The average particle size of the organic filler may be 50 nm or more.

The median diameter (d50) at 50% is used as the average particle size of the organic filler. The average particle size can be measured using a laser diffraction scattering particle size distribution measuring device.

Examples of the coupling agent include silane coupling agents, titanium coupling agents, and aluminum coupling agents. Examples of the silane coupling agent include vinyl silane, amino silane, imidazole silane, and epoxy silane.

(Resin film)
The above-mentioned resin composition is molded into a film to obtain a resin film (B-stage product/B-stage film). The above-mentioned resin material is preferably a resin film. The resin film is preferably a B-stage film.

Methods for forming a resin composition into a film to obtain a resin film include the following: Extrusion molding, in which the resin composition is melt-kneaded and extruded using an extruder, and then molded 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. Other conventionally known film molding methods. Extrusion molding and casting molding are preferred because they can be made thinner. Films include sheets.

The resin composition is molded into a film and dried by heating at, for example, 50°C to 150°C for 1 to 10 minutes to a degree that does not cause excessive curing due to heat, to obtain a resin film that is a B-stage film.

The film-like resin composition that can be obtained by the drying process described above is called a B-stage film. The B-stage film is in a semi-cured state. A semi-cured product is not completely cured, and curing can continue.

The resin film does not have to be a prepreg. If the resin film is not a prepreg, migration will not occur along the glass cloth or the like. In addition, when the resin film is laminated or precured, irregularities caused by the glass cloth will not occur on the surface.

The 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 metal foil is preferably a copper foil.

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 subjected to a release treatment, if necessary.

From the viewpoint of controlling the degree of cure 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 equal to or greater than the thickness of the conductor layer (metal layer) that forms the circuit. The thickness of the insulating layer is preferably 5 μm or more and preferably 200 μm or less.

(Semiconductor device, printed wiring board, copper-clad laminate, and multilayer printed wiring board)
The above-mentioned resin material is suitably used for forming a molding resin in which a semiconductor chip is embedded in a semiconductor device.

The above resin material is preferably used as an insulating material. The above resin material is preferably used to form an insulating layer in a printed wiring board.

The printed wiring board is obtained, for example, by heating and pressurizing the resin material.

A laminated member having a metal layer on one or both sides can be laminated onto the resin film. A laminated structure can be suitably obtained, which includes a laminated member having a metal layer on its surface and a resin film laminated on the surface of the metal layer, the resin film being the resin material described above. There is no particular limitation on the method for laminating the resin film and the laminated member having the metal layer on its surface, and a known method can be used. For example, the resin film can be laminated onto the laminated member having a metal layer on its surface while applying pressure with or without heating using a device such as a parallel plate press or a roll laminator.

The material of the metal layer is preferably copper.

The lamination target component having the above-mentioned metal layer on its surface may be a metal foil such as copper foil.

The above resin material is preferably used to obtain a copper-clad laminate. One example of the above copper-clad laminate is a copper-clad laminate that includes a copper foil and a resin film laminated on one surface of the copper foil.

The thickness of the copper foil of the copper-clad laminate is not particularly limited. The thickness of the copper foil is preferably within the range of 1 μm to 50 μm. In addition, 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 of forming the irregularities is not particularly limited. Examples of the method of forming the irregularities include a method of forming the irregularities by treatment using a known chemical solution.

The above resin materials are suitable for use in producing multilayer substrates.

One example of the multilayer board is a multilayer board including a circuit board and an insulating layer laminated on the circuit board. The insulating layer of the multilayer board is formed from the resin material. The insulating layer of the multilayer board may also be formed from the resin film of the laminate film using a laminate film. The insulating layer is preferably laminated on the surface of the circuit board on which the circuits are provided. A portion of the insulating layer is preferably embedded between the circuits.

In the multilayer board, it is preferable that the surface of the insulating layer opposite the surface on which the circuit board is laminated is roughened.

The roughening method can be a conventionally known roughening method, and is not particularly limited. The surface of the insulating layer may be subjected to a swelling treatment before the roughening treatment.

It is also preferable that the multilayer substrate further comprises a copper plating layer laminated on the roughened surface of the insulating layer.

Another example of the multilayer board is a multilayer board comprising a circuit board, an insulating layer laminated on the surface of the circuit board, and copper foil laminated on the surface of the insulating layer opposite to the surface on which the circuit board is laminated. The insulating layer is preferably formed by using a copper-clad laminate comprising copper foil and a resin film laminated on one surface of the copper foil, and curing the resin film. Furthermore, the copper foil is preferably etched to form a copper circuit.

Another example of the multilayer board is a multilayer board including a circuit board and a plurality of insulating layers laminated on a surface of the circuit board. At least one of the insulating layers arranged on the circuit board is formed using the resin material. It is preferable that the multilayer board further includes a circuit laminated on at least one surface of the insulating layer formed using the resin film.

Among multilayer substrates, multilayer printed wiring boards require a low dielectric tangent and high insulation reliability from the insulating layer. The resin material of the present invention can effectively improve insulation reliability by lowering the dielectric tangent and improving adhesion between the insulating layer and the metal layer and etching performance. Therefore, the resin material of the present invention is suitable for use in forming an insulating layer in a multilayer printed wiring board.

The multilayer printed wiring board includes, for example, a circuit board, a plurality of insulating layers arranged on the surface of the circuit board, and a metal layer arranged between the insulating layers. At least one of the insulating layers is a cured product of the resin material.

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

In the multilayer printed wiring board 11 shown in FIG. 1, multiple insulating layers 13-16 are laminated on the upper surface 12a of the circuit board 12. The insulating layers 13-16 are hardened layers. A metal layer 17 is formed on a partial area of the upper surface 12a of the circuit board 12. Of the multiple insulating layers 13-16, the insulating layers 13-15 other than the insulating layer 16 located on the outer surface opposite the circuit board 12 side have a metal layer 17 formed on a partial area of the upper surface. The metal layer 17 is a circuit. The metal layer 17 is disposed between the circuit board 12 and the insulating layer 13, and between each of the laminated insulating layers 13-16. The lower metal layer 17 and the upper metal layer 17 are connected to each other by at least one of a via hole connection and a through hole connection not shown.

In the multilayer printed wiring board 11, the insulating layers 13 to 16 are formed from the cured product of the resin material. In this embodiment, the surfaces of the insulating layers 13 to 16 are roughened, so that fine holes (not shown) are formed in the surfaces of the insulating layers 13 to 16. The metal layer 17 extends into the fine holes. In the multilayer printed wiring 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. In the multilayer printed wiring 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).

(Roughening treatment and swelling treatment)
The resin material is preferably used to obtain a cured product to be subjected to roughening treatment or desmear treatment. The cured product also includes a pre-cured product that can be further cured.

In order to form fine irregularities on the surface of the cured product obtained by pre-curing the resin material, the cured product is preferably subjected to a roughening treatment. Before the roughening treatment, the cured product is preferably subjected to a swelling treatment. After the pre-curing and before the roughening treatment, the cured product is preferably subjected to a swelling treatment, and is further preferably cured after the roughening treatment. However, the cured product does not necessarily have to be subjected to a swelling treatment.

The swelling treatment may be carried out by treating the cured product with an aqueous solution or an organic solvent dispersion of a compound mainly composed of ethylene glycol. The swelling liquid used in the swelling treatment generally contains an alkali as a pH adjuster. The swelling liquid preferably contains sodium hydroxide. Specifically, the swelling treatment is carried out by treating the cured product with a 40% by weight aqueous solution of ethylene glycol at a treatment temperature of 30°C to 85°C for 1 to 30 minutes. The temperature of the swelling treatment is preferably within the range of 50°C to 85°C. If the temperature of the swelling treatment is too low, the swelling treatment takes a long time and the adhesive strength between the cured product and the metal layer tends to be lower.

In the above roughening treatment, a chemical oxidizing agent such as a manganese compound, a chromium compound, or a persulfate compound is used. These chemical oxidizing agents are used as an aqueous solution or an organic solvent dispersion solution after water or an organic solvent is added. The roughening liquid used in the roughening treatment generally contains an alkali as a pH adjuster or the like. The roughening liquid preferably contains sodium hydroxide.

The manganese compounds include potassium permanganate and sodium permanganate. The chromium compounds include potassium dichromate and potassium chromate anhydride. The persulfate compounds include sodium persulfate, potassium persulfate, and ammonium persulfate.

The arithmetic mean roughness Ra of the surface of the cured product is preferably 10 nm or more, and is preferably less than 300 nm, more preferably less than 200 nm, and even more preferably less than 150 nm. In this case, the adhesive strength between the cured product and the metal layer is increased, and finer wiring is formed on the surface of the insulating layer. Furthermore, conductor loss can be suppressed, and signal loss can be kept low. The arithmetic mean roughness Ra is measured in accordance with JIS B0601:1994.

(Desmearing)
Through holes may be formed in the cured product obtained by pre-curing the resin material. In the multilayer board, etc., vias or through holes are formed as the through holes. For example, vias can be formed by irradiating a laser such as a _CO2 laser. The diameter of the via is not particularly limited, but is about 60 μm to 80 μm. Due to the formation of the through holes, smears, which are resin residues derived from the resin components contained in the cured product, are often formed at the bottom of the via.

In order to remove the smears, the surface of the cured product is preferably subjected to a desmear treatment. The desmear treatment may also serve as a roughening treatment.

In the desmear treatment, a chemical oxidizing agent such as a manganese compound, a chromium compound, or a persulfate compound is used, as in the roughening treatment. These chemical oxidizing agents are used as an aqueous solution or an organic solvent dispersion solution after water or an organic solvent is added. The desmear treatment liquid used in the desmear treatment generally contains an alkali. The desmear treatment liquid preferably contains sodium hydroxide.

By using the above resin material, the surface roughness of the desmeared cured product is sufficiently small.

The present invention will be specifically explained below by giving examples and comparative examples. The present invention is not limited to the following examples.

The following materials were prepared:

(Maleimide Compound Containing Imide Skeleton)
Imide skeleton-containing maleimide compound 1:
According to the following Synthesis Example 1, an imide skeleton-containing maleimide compound 1 (molecular weight 9,500) represented by the following formula (X1) was synthesized.

In the above formula (X1), X11 represents a structure represented by the following formula (X11), X12 represents a structure represented by the following formula (X12), X13 represents a structure represented by the following formula (X13), and R represents a partial skeleton derived from a diamine compound. In addition, among the structures represented by the following formula (X12), the skeleton derived from dimer diamine is a representative structure of the skeleton derived from the dimer diamine, and for example, the hydrocarbon chain in the skeleton derived from the dimer diamine may have an unsaturated bond. For example, in the following formula (X12), an imide skeleton-containing maleimide compound in which an unsaturated bond exists in the hydrocarbon chain in the skeleton derived from the dimer diamine may be included. The synthesized imide skeleton-containing maleimide compound may include an imide skeleton-containing maleimide compound in which the hydrocarbon chain in the skeleton derived from the dimer diamine has an unsaturated bond.

<Synthesis Example 1>
150 mL of toluene and 100 mL of N-methyl-2-pyrrolidone were placed in a 500 mL eggplant flask, and 20.5 g (50 mmol) of Priamine 1075, 6.46 g (25 mmol) of 2,2-bis(3-amino-4-hydroxyphenyl)propane, and 7.71 g (50 mmol) of bis(aminomethyl)norbornane were added. Then, 21.8 g (100 mmol) of pyromellitic dianhydride was added little by little. Then, the eggplant flask was attached to a Dean-Stark apparatus and heated under reflux for 4 hours. In this way, a compound having amines at both ends and a plurality of imide skeletons was obtained. After removing the moisture discharged during condensation and returning to room temperature, 5.88 g (60 mmol) of maleic anhydride was added and stirred, and similarly heated and reacted. In this way, a compound having a maleimide skeleton at both ends was obtained. The obtained solution was washed with water, the organic layer was dropped into methanol, and the product was reprecipitated, collected, and then dried to obtain an imide skeleton-containing maleimide compound 1.

Imide skeleton-containing maleimide compound 2:
According to the following Synthesis Example 2, an imide skeleton-containing maleimide compound 2 (molecular weight 22,000) represented by the following formula (X2) was synthesized.

In the above formula (X2), X21 represents a structure represented by the following formula (X21), X22 represents a structure represented by the following formula (X22), X23 represents a structure represented by the following formula (X23), and R represents a partial skeleton derived from any diamine compound. l in the following formula (X21), m in the following formula (X22), and n in the following formula (X23) satisfy the formula: n/(l+m+n)=0.2. Among the structures represented by the following formula (X22), the skeleton derived from the dimer diamine is a representative structure of the skeleton derived from the dimer diamine, and for example, the hydrocarbon chain in the skeleton derived from the dimer diamine may have an unsaturated bond. For example, in the following formula (X22), an imide skeleton-containing maleimide compound in which an unsaturated bond exists in the hydrocarbon chain in the skeleton derived from the dimer diamine may be included. The synthesized imide skeleton-containing maleimide compound may include an imide skeleton-containing maleimide compound in which the hydrocarbon chain in the skeleton derived from the dimer diamine has an unsaturated bond.

<Synthesis Example 2>
150 mL of toluene and 100 mL of N-methyl-2-pyrrolidone were placed in a 500 mL eggplant flask, and 20.0 g (48.8 mmol) of Priamine 1075, 5.01 g (32.5 mmol) of bis(aminomethyl)norbornane, and 2.25 g (25 mmol) of diaminopropanol were added. Then, 65.7 g (126 mmol) of 4,4'-(4,4'-isopropylidenediphenoxy)diphthalic anhydride were added little by little. Then, the eggplant flask was attached to a Dean-Stark apparatus and heated under reflux for 4 hours. In this way, a compound having amines at both ends and multiple imide skeletons was obtained. After removing the moisture discharged during condensation and returning to room temperature, 2.35 g (25 mmol) of phenol was added and stirred, and further, 1.5 g of paraformaldehyde was added little by little and stirred. Then, the mixture was reacted at 40°C, and then reacted at 60°C for 1 hour and at 80°C for 1 hour. In this way, a compound having benzoxazine groups at both ends was obtained. Next, it was washed with water, and 3.96 g (18.8 mmol) of 6-maleimidocaproic acid was added to the organic layer, stirred, and similarly heated to react. The obtained solution was washed with water, and the organic layer was dropped into methanol to reprecipitate the maleimide compound, which was then recovered and dried to obtain imide skeleton-containing maleimide compound 2.

Imide skeleton-containing maleimide compound 3:
According to the following Synthesis Example 3, an imide skeleton-containing maleimide compound 1 (molecular weight 6,500) represented by the following formula (X3) was synthesized.

In the above formula (X3), X31 represents a structure represented by the following formula (X31), X32 represents a structure represented by the following formula (X32), X33 represents a structure represented by the following formula (X33), and R represents a partial skeleton derived from a diamine compound. Among the structures represented by the following formula (X32), the skeleton derived from dimer diamine is a representative structure of the skeleton derived from the dimer diamine, and for example, the hydrocarbon chain in the skeleton derived from the dimer diamine may have an unsaturated bond. For example, in the following formula (X32), an imide skeleton-containing maleimide compound in which an unsaturated bond exists in the hydrocarbon chain in the skeleton derived from the dimer diamine may be included. The synthesized imide skeleton-containing maleimide compound may include an imide skeleton-containing maleimide compound in which the hydrocarbon chain in the skeleton derived from the dimer diamine has an unsaturated bond. In addition, in the following formula (X31), a skeleton derived from diphenyl-3,3',4,4'-tetracarboxylic dianhydride is shown, but the skeleton may be replaced with a skeleton derived from pyromellitic dianhydride. In addition, the position of the skeleton derived from the dianhydride is random.

<Synthesis Example 3>
150 mL of toluene and 100 mL of N-methyl-2-pyrrolidone were placed in a 500 mL eggplant flask. 16.4 g (40 mmol) of Priamine 1075, 7.33 g (20 mmol) of 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane (manufactured by Tokyo Chemical Industry Co., Ltd.), and 6.17 g (40 mmol) of bis(aminomethyl)norbornane (manufactured by Mitsui Fine Chemicals Co., Ltd.) were further added to this eggplant flask. Next, 9.81 g (45 mmol) of pyromellitic dianhydride and 13.24 g (45 mmol) of diphenyl-3,3',4,4'-tetracarboxylic dianhydride (manufactured by Tokyo Chemical Industry Co., Ltd.) were added little by little. Next, the eggplant flask was attached to a Dean-Stark apparatus and heated under reflux for 4 hours. In this way, a compound having amines at both ends and having multiple imide skeletons was obtained. The water discharged during the condensation was removed, and the mixture was returned to room temperature, after which 5.88 g (60 mmol) of maleic anhydride was added, stirred, and similarly heated to react. In this way, a compound having a maleimide skeleton at both ends was obtained. After washing the obtained solution with water, the organic layer was dropped into methanol to reprecipitate the maleimide compound, which was then recovered and dried to obtain an imide skeleton-containing maleimide compound 3.

The molecular weights of the imide skeleton-containing maleimide compounds synthesized in Synthesis Examples 1 to 3 were determined as follows.

GPC (Gel Permeation Chromatography) Measurement:
Using a high performance liquid chromatograph system manufactured by Shimadzu Corporation, measurements were performed at a column temperature of 40°C and a flow rate of 1.0 ml/min, with tetrahydrofuran (THF) as the developing medium. An "SPD-10A" was used as the detector, and two "KF-804L" columns (exclusion limit molecular weight 400,000) manufactured by Shodex Corporation were used in series. "TSK Standard Polystyrene" manufactured by Tosoh Corporation was used as the standard polystyrene, and a calibration curve was created using substances with weight average molecular weights Mw = 354,000, 189,000, 98,900, 37,200, 17,100, 9,830, 5,870, 2,500, 1,050, and 500, and the molecular weight was calculated.

(Thermosetting Compound)
Biphenyl type epoxy compound ("NC-3000" manufactured by Nippon Kayaku Co., Ltd.)
Naphthalene-type epoxy compound ("ESN-475V" manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.)
Resorcinol diglycidyl ether ("EX-201" manufactured by Nagase Chemtex Corporation)
Amide bond-containing epoxy compound ("WHR-991S" manufactured by Nippon Kayaku Co., Ltd.)
Maleimide compound (N-alkylbismaleimide, "BMI-1500" manufactured by Designer Molecules Inc.)

(Inorganic filler)
Silica-containing slurry (75% silica by weight: Admatechs "SC4050-HOA", average particle size 1.0 μm, aminosilane treatment, cyclohexanone 25% by weight)

(Hardening agent)
Active ester compound 1-containing solution (DIC Corporation "EXB-9416-70BK", solid content 70% by weight)
Active ester compound 2-containing liquid (DIC Corporation "HPC-8150-62T", solid content 62% by weight)
Phenol compound-containing liquid (DIC Corporation "LA-1356", solid content 60% by weight)

(Cure Accelerator)
Dimethylaminopyridine ("DMAP" manufactured by Wako Pure Chemical Industries, Ltd.)
2-Phenyl-4-methylimidazole ("2P4MZ" manufactured by Shikoku Chemical Industry Co., Ltd., anionic curing accelerator)

(Thermoplastic resin)
Polyimide compounds (polyimide resins):
A solution containing a polyimide compound (non-volatile content: 26.8% by weight), which is a reaction product of tetracarboxylic dianhydride and dimer diamine, was synthesized according to Synthesis Example 4 below.

<Synthesis Example 4>
In a reaction vessel equipped with a stirrer, a water divider, a thermometer and a nitrogen gas inlet tube, 300.0 g of tetracarboxylic dianhydride ("BisDA-1000" manufactured by SABIC Japan LLC) and 665.5 g of cyclohexanone were placed, and the solution in the reaction vessel was heated to 60 ° C. Then, 89.0 g of dimer diamine ("PRIAMINE 1075" manufactured by Croda Japan) and 54.7 g of 1,3-bisaminomethylcyclohexane (manufactured by Mitsubishi Gas Chemical Co., Ltd.) were dropped into the reaction vessel. Next, 121.0 g of methylcyclohexane and 423.5 g of ethylene glycol dimethyl ether were added to the reaction vessel, and the imidization reaction was carried out at 140 ° C. for 10 hours. In this way, a polyimide compound-containing solution (non-volatile content 26.8 wt%) was obtained. The molecular weight (weight average molecular weight) of the obtained polyimide compound was 20,000. The molar ratio of acid component/amine component was 1.04.

The molecular weight of the polyimide compound synthesized in Synthesis Example 4 was determined as follows.

GPC (Gel Permeation Chromatography) Measurement:
Using a high performance liquid chromatograph system manufactured by Shimadzu Corporation, measurements were performed at a column temperature of 40°C and a flow rate of 1.0 ml/min, with tetrahydrofuran (THF) as the developing medium. An "SPD-10A" was used as the detector, and two "KF-804L" columns (exclusion limit molecular weight 400,000) manufactured by Shodex Corporation were used in series. "TSK Standard Polystyrene" manufactured by Tosoh Corporation was used as the standard polystyrene, and a calibration curve was created using substances with weight average molecular weights Mw = 354,000, 189,000, 98,900, 37,200, 17,100, 9,830, 5,870, 2,500, 1,050, and 500, and the molecular weight was calculated.

(Examples 1 to 4 and Comparative Examples 1 to 3)
The components shown in Table 1 below were mixed in the amounts (unit: parts by weight of solid content) shown in Table 1 below, and stirred at room temperature until a homogeneous solution was obtained, to obtain a resin material.

Preparation of resin film:
The obtained resin material was applied to the release-treated surface of a release-treated PET film ("XG284" manufactured by Toray Industries, Inc., thickness 25 μm) using an applicator, and then dried for 2 minutes and 30 seconds in a gear oven at 100° C. to volatilize the solvent. In this way, a laminated film (a laminated film of a PET film and a resin film) was obtained in which a resin film (B-stage film) having a thickness of 40 μm was laminated on the PET film.

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

[Criteria for dielectric tangent]
○: Dielectric tangent is less than 2.9×10 ⁻³ ×: Dielectric tangent is 2.9×10 ⁻³ or more

(2) Thermal dimensional stability (average coefficient of linear expansion (CTE))
The resulting 40 μm thick resin film (B-stage film) was heated at 190° C. for 90 minutes, and the resulting cured product was cut into pieces measuring 3 mm x 25 mm. The average linear expansion coefficient (ppm/° C.) of the cut cured product from 25° C. to 150° C. was calculated using a thermomechanical analyzer ("EXSTAR TMA/SS6100" manufactured by SII NanoTechnology Inc.) under conditions of a tensile load of 33 mN and a heating rate of 5° C./min.

[Criteria for Average Linear Expansion Coefficient]
○○: Average linear expansion coefficient is 23 ppm/°C or less. ○: Average linear expansion coefficient is more than 23 ppm/°C and less than 27 ppm/°C. ×: Average linear expansion coefficient is more than 27 ppm/°C.

(3) Elongation properties The obtained resin film (B-stage film) having a thickness of 40 μm was heated at 190° C. for 90 minutes, and the obtained cured product was cut into a size of 10 mm×100 mm. Using a tensile tester (Shimadzu Corporation, “AGS-J 100N”), measurements were performed under conditions of a chuck distance of 60 mm and a pulling speed of 5 mm/min, and the maximum elongation was measured. The initial tension was 0.35 N. The measurement was repeated five times, and the average value of the breaking elongation (average breaking elongation) was calculated.

[Elongation property evaluation criteria]
◯: Average breaking elongation is 1.5% or more. ○: Average breaking elongation is 1.2% or more and less than 1.5%. ×: Average breaking elongation is less than 1.2%.

(4) Bending properties (repeated bending properties)
The resulting 40 μm thick resin film (B-stage film) was heated at 190° C. for 90 minutes, and the resulting cured product was cut into a size of 30 mm×150 mm. A folding test was performed using a planar U-shaped folding tester (manufactured by Yuasa Corporation) under the conditions of 200 times/min, 180° folding (folding gap 5 mm), and film stroke 70 mm. The measurement was repeated five times, and the average value was calculated.

[Criteria for flexural properties (repeated bending properties)]
○○: No cracks after 2000 folds ○: Cracks after 100 or more folds but less than 2000 folds ×: Cracks after less than 100 folds

(5) Glass transition temperature The obtained resin film (B-stage film) having a thickness of 40 μm was heated at 190° C. for 90 minutes, and the obtained cured product was cut into a size of 5 mm×50 mm. Measurements were performed using a thermomechanical analyzer (SII Nanotechnology Inc.'s "DMS6100") under the following conditions: chuck distance 20 mm, amplitude 10 μm, initial tension amplitude value 400 mN, temperature increase rate of 5° C./min from 50° C. to 330° C., and frequency of 10 Hz. In the obtained measurement results, the peak temperature of the loss tangent was taken as the glass transition temperature Tg (° C.).

[Criteria for glass transition temperature]
◯: Glass transition temperature is 170° C. or higher. ×: Glass transition temperature is less than 170° C.

(6) Desmearing ability (ability to remove residues at the bottom of vias)
Lamination and semi-curing process:
The obtained resin film was vacuum laminated onto a CCL substrate ("E679FG" manufactured by Hitachi Chemical Co., Ltd.) and semi-cured by heating at 180° C. for 30 minutes. In this way, a laminate A in which a semi-cured resin film was laminated onto a CCL substrate was obtained.

Via formation:
A via (through hole) having a diameter of 60 μm at the top and a diameter of 40 μm at the bottom (bottom) was formed using a _CO2 laser (manufactured by Hitachi Via Mechanics Co., Ltd.) in the semi-cured resin film of the obtained laminate A. In this way, a laminate B was obtained in which the semi-cured resin film was laminated on the CCL substrate and the via (through hole) was formed in the semi-cured resin film.

Via bottom residue removal process:
(a) Swelling Treatment The obtained laminate B was placed in a swelling liquid (Swelling Dip Securigant P, manufactured by Atotech Japan) at 60° C. and shaken for 10 minutes. Thereafter, it was washed with pure water.

(b) Permanganate treatment (roughening treatment and desmear treatment)
The laminate B after the swelling treatment was placed in a roughening aqueous solution of potassium permanganate ("Concentrate Compact CP" manufactured by Atotech Japan) at 80° C. and was shaken for 30 minutes. Next, it was treated for 2 minutes using a cleaning solution ("Reduction Securigant P" manufactured by Atotech Japan) at 25° C., and then washed with pure water to obtain an evaluation sample.

The bottom of the via of the evaluation sample was observed with a scanning electron microscope (SEM) and the maximum smear length from the wall surface of the via bottom was measured. The removability of the residue at the via bottom was judged according to the following criteria.

[Criteria for Removability of Residue at Via Bottom]
○○: The maximum smear length is less than 2 μm. ○: The maximum smear length is 2 μm or more and less than 3 μm. ×: The maximum smear length is 3 μm or more.

(7) Adhesion between insulating layer and 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 × 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 Co., Ltd.'s "Cz8101" to roughen the copper foil surface. On both sides of the roughened copper-clad laminate, the resin film (B stage film) side of the laminated film was laminated on the copper-clad laminate using Meiki Seisakusho Co., Ltd.'s "batch vacuum laminator MVLP-500-IIA" to obtain a laminated structure. The lamination conditions were reduced pressure for 30 seconds to an atmospheric pressure of 13 hPa or less, and then pressed at 100 ° C. and a pressure of 0.4 MPa for 30 seconds.

Film peeling process:
The PET films on both sides of the resulting laminated structure were peeled off.

Copper foil attachment process:
The shiny side of the copper foil (thickness 35 μm, manufactured by Mitsui Kinzoku Co., Ltd.) was subjected to Cz treatment ("Cz8101" manufactured by MEC Co., Ltd.) to etch the copper foil surface by about 1 μm. The etched copper foil was attached to the laminated structure from which the PET film had been peeled off to obtain a copper foil-attached substrate. The obtained copper foil-attached substrate was heat-treated at 190° C. for 90 minutes in a gear oven to obtain an evaluation sample.

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

[Peel strength evaluation criteria]
○○: Peel strength is 0.6 kgf or more. ○: Peel strength is 0.4 kgf or more but less than 0.6 kgf. ×: Peel strength is less than 0.4 kgf.

The composition and results are shown in Table 1 below.

11: multilayer printed wiring board 12: circuit board 12a: upper surface 13-16: insulating layers 17: metal layer

Claims (17)

A thermosetting compound;
an imide skeleton-containing maleimide compound having one or more maleimide skeletons and two or more imide skeletons and having at least one functional group capable of reacting with the thermosetting compound ;
The resin material , wherein the imide skeleton-containing maleimide compound has a skeleton derived from a dimer triamine or a skeleton derived from a trimer triamine . The resin material according to claim 1, wherein the imide skeleton-containing maleimide compound has two or more maleimide skeletons and has the maleimide skeleton at an end. The resin material according to claim 1 or 2, wherein the thermosetting compound is a maleimide compound, an epoxy compound, a vinyl compound, or a benzoxazine compound. The resin material according to any one of claims 1 to 3, wherein the functional group in the imide skeleton-containing maleimide compound capable of reacting with the thermosetting compound is a vinyl group, a phenolic hydroxyl group, or an active ester group. The resin material according to any one of claims 1 to 4, wherein the imide skeleton-containing maleimide compound has a skeleton derived from a dimer diamine. The resin material according to claim 5 , wherein in the imide skeleton-containing maleimide compound, the skeleton derived from the dimer diamine is directly bonded to the maleimide skeleton. The resin material according to any one of claims 1 to 6 , wherein the imide skeleton-containing maleimide compound has a skeleton derived from a reaction product of a diamine compound other than dimer diamine and an acid dianhydride. The resin material according to any one of claims 1 to 7 , wherein the molecular weight of the imide skeleton-containing maleimide compound is 1,000 or more and 50,000 or less. The resin material according to any one of claims 1 to 8 , further comprising an inorganic filler. The resin material according to any one of claims 1 to 9 , further comprising a curing agent. The resin material according to claim 10 , wherein at least one of the thermosetting compound and the curing agent has an amide bond or an imide bond. the thermosetting compound comprises an epoxy compound,
The resin material according to claim 10 or 11 , wherein the curing agent comprises at least one component selected from the group consisting of a phenol compound, an active ester compound, a cyanate ester compound, and a carbodiimide compound. The resin material according to claim 10 , wherein the curing agent comprises a phenol compound and an active ester compound. The resin material according to any one of claims 1 to 13 , wherein the thermosetting compound has an amide bond or an imide bond. The resin material according to any one of claims 1 to 14 , which is a resin film. The resin material according to any one of claims 1 to 15 , which is used to form an insulating layer in a multilayer printed wiring board. A circuit board;
a plurality of insulating layers disposed on a surface of the circuit board;
a metal layer disposed between a plurality of the insulating layers;
A multilayer printed wiring board, wherein at least one of the insulating layers is a cured product of the resin material according to any one of claims 1 to 16 .

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