JP7704944B2 - Resin materials and multilayer printed wiring boards - Google Patents

Description

The present invention relates to a resin material containing a compound having a skeleton derived from an acid dianhydride having a norbornane skeleton and a compound having an aromatic skeleton. The present invention also relates to a multilayer printed wiring board using the above 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 polyimide alloy containing a cyclic aliphatic polyimide and a wholly aromatic polyimide, in which the content of the cyclic aliphatic polyimide relative to the total amount of the cyclic aliphatic polyimide and the wholly aromatic polyimide is 62% by mass to 95% by mass. The cyclic aliphatic polyimide is a polycondensation product of a cyclic aliphatic tetracarboxylic acid dianhydride having an aliphatic six-membered ring structure and at least one diamine compound selected from the group consisting of aromatic diamines and aliphatic diamines. The wholly aromatic polyimide is a polycondensation product of at least one aromatic tetracarboxylic acid dianhydride selected from the group consisting of diphenyl-3,3',4,4'-tetracarboxylic acid dianhydride and benzene-1,2,4,5-tetracarboxylic acid dianhydride and an aromatic diamine.

JP 2020-125466 A

In Patent Document 1, a resin material containing a compound having a skeleton derived from an acid dianhydride is used. However, when an insulating layer is formed using a conventional resin material containing a compound having a skeleton derived from an acid dianhydride, the dielectric tangent of the cured product may not be sufficiently low, or the thermal dimensional stability may not be sufficiently high.

In addition, in resin materials that contain a compound having a skeleton derived only from an aliphatic acid dianhydride as the acid dianhydride, it can be difficult to improve compatibility with a compound having an aromatic skeleton, for example, or to improve the heat resistance (glass transition temperature) of the cured product.

The object of the present invention is to provide a resin material that can increase compatibility, reduce the dielectric tangent in the cured product of the resin material, and increase the thermal dimensional stability and glass transition temperature. Another object of the present invention is to provide a multilayer printed wiring board using the above resin material.

According to a broad aspect of the present invention, there is provided a resin material comprising a first compound having a skeleton derived from an acid dianhydride having a norbornane skeleton and a second compound having an aromatic skeleton, the first compound having a structural unit having an imide bond as a repeating structural unit, the second compound not having a structural unit having an imide skeleton as a repeating structural unit, the molecular weight of the first compound being greater than 1000, and the second compound being a thermosetting compound.

In a particular aspect of the resin material according to the present invention, the molecular weight of the second compound is 1000 or less.

In a particular aspect of the resin material according to the present invention, the first compound has an aromatic ring.

In a particular aspect of the resin material according to the present invention, the first compound has a skeleton derived from an acid dianhydride that does not have a norbornane skeleton and has a phthalimide skeleton.

In a particular aspect of the resin material according to the present invention, the first compound has a skeleton derived from an aliphatic diamine compound.

In a particular aspect of the resin material according to the present invention, the first compound has a skeleton derived from an aliphatic diamine compound having a cyclohexane skeleton.

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

In a particular aspect of the resin material according to the present invention, in the first compound, the average proportion of the skeleton derived from the dimer diamine is 10 mol % or more and 90 mol % or less out of 100 mol % of the skeleton derived from all diamine compounds.

In a particular aspect of the resin material according to the present invention, the first compound has a maleimide skeleton or a benzoxazine skeleton.

In a particular aspect of the resin material according to the present invention, the first compound has a skeleton derived from an acid dianhydride that does not have a norbornane skeleton and does not have a phthalimide skeleton.

In a particular aspect of the resin material according to the present invention, the molecular weight of the first compound is 50,000 or less.

In a particular aspect of the resin material according to the present invention, the second compound includes an epoxy compound.

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 curing agent, and the curing agent includes an active ester compound.

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 first compound having a skeleton derived from an acid dianhydride having a norbornane skeleton, and a second compound having an aromatic skeleton, the first compound having a structural unit having an imide bond as a repeating structural unit, and the second compound not having a structural unit having an imide skeleton as a repeating structural unit. In the resin material according to the present invention, the molecular weight of the first compound exceeds 1000, and the second compound is a thermosetting compound. Since the resin material according to the present invention has the above configuration, it is possible to increase compatibility, and in the cured product of the resin material, it is possible to reduce the dielectric tangent and increase the thermal dimensional stability and glass transition temperature.

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 first compound having a skeleton derived from an acid dianhydride having a norbornane skeleton, and a second compound having an aromatic skeleton, the first compound having a structural unit having an imide bond as a repeating structural unit, and the second compound not having a structural unit having an imide skeleton as a repeating structural unit. In the resin material according to the present invention, the molecular weight of the first compound exceeds 1000, and the second compound is a thermosetting compound.

The resin material according to the present invention has the above-mentioned configuration, and therefore can improve compatibility, and in the cured product of the resin material, can lower the dielectric tangent, and can improve the thermal dimensional stability and glass transition temperature. The resin material according to the present invention uses a first compound having a specific skeleton and a second compound having a specific skeleton, and therefore can particularly improve compatibility and the glass transition temperature of the cured product.

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 resin material. When the resin material is a resin film, the resin film is preferably a thermosetting resin film.

Below, we will explain the details of each component used in the resin material of the present invention, as well as applications of the resin material of the present invention.

[First compound]
The resin material according to the present invention includes a first compound having a skeleton derived from an acid dianhydride having a norbornane skeleton. The first compound has a structural unit having an imide bond as a repeating structural unit. Only one type of the first compound may be used, or two or more types may be used in combination.

The first compound may be a thermosetting compound or a thermoplastic compound.

The first compound has a skeleton derived from an acid dianhydride having a norbornane skeleton (an acid dianhydride containing a norbornane skeleton; a first acid dianhydride).

The above-mentioned acid dianhydride having a norbornane skeleton (first acid dianhydride) includes an acid dianhydride represented by the following formula (1A), an acid dianhydride represented by the following formula (1B), an acid dianhydride represented by the following formula (1C), and an acid dianhydride represented by the following formula (1D). When these acid dianhydrides are used, the above-mentioned first compound has a skeleton derived from an acid dianhydride represented by the following formula (1A), (1B), (1C), or (1D).

In the first compound, the average proportion of the skeleton derived from the acid dianhydride having the norbornane skeleton (first acid dianhydride) in 100 mol% of the skeletons derived from all acid dianhydrides is preferably 20 mol% or more, more preferably 30 mol% or more, and even more preferably 40 mol% or more. In the first compound, the average proportion of the skeleton derived from the acid dianhydride having the norbornane skeleton (first acid dianhydride) in 100 mol% of the skeletons derived from all acid dianhydrides is preferably 90 mol% or less, more preferably 80 mol% or less, and even more preferably 70 mol% or less. When the average proportion of the skeleton derived from the first acid dianhydride is the above lower limit or more and the above upper limit or less, the effect of the present invention can be more effectively exhibited.

The first compound preferably has a skeleton derived from an acid dianhydride that does not have a norbornane skeleton and has a phthalimide skeleton (norbornane skeleton-free-phthalimide skeleton-containing acid dianhydride; second acid dianhydride). In this case, the dielectric tangent of the cured product can be further reduced, and the thermal dimensional stability of the cured product can be further improved. Compounds that have a norbornane skeleton and a phthalimide skeleton are classified as the first acid dianhydride.

Examples of the acid dianhydride (second acid dianhydride) that does not have a norbornane skeleton and has a phthalimide skeleton include pyromellitic dianhydride, 4,4'-oxydiphthalic anhydride, and 4,4'-biphthalic anhydride.

In the first compound, the average proportion of the skeleton derived from the acid dianhydride (second acid dianhydride) that does not have the norbornane skeleton and has a phthalimide skeleton in 100 mol% of the skeleton derived from all the acid dianhydrides is preferably 10 mol% or more, more preferably 20 mol% or more, and even more preferably 30 mol% or more. In the first compound, the average proportion of the skeleton derived from the acid dianhydride (second acid dianhydride) that does not have the norbornane skeleton and has a phthalimide skeleton in 100 mol% of the skeleton derived from all the acid dianhydrides is preferably 80 mol% or less, more preferably 70 mol% or less, and even more preferably 60 mol% or less. When the average proportion of the skeleton derived from the acid dianhydride that does not have the norbornane skeleton and has a phthalimide skeleton is the above lower limit or more and the above upper limit or less, the effect of the present invention can be more effectively exhibited.

It is preferable that the first compound has a skeleton derived from an acid dianhydride that does not have a norbornane skeleton and does not have a phthalimide skeleton (a norbornane skeleton-not containing a phthalimide skeleton-acid dianhydride; a third acid dianhydride).

The acid dianhydride (third acid dianhydride) that does not have a norbornane skeleton and does not have a phthalimide skeleton may or may not have an aromatic skeleton. It is preferable that the third acid dianhydride does not have an aromatic skeleton. From the viewpoint of improving the desmear property, it is preferable that the third acid dianhydride has a non-aromatic double bond.

Examples of the acid dianhydride (third acid dianhydride) that does not have a norbornane skeleton and does not have a phthalimide skeleton include bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, 5-(2,5-dioxotetrahydrofuryl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, and 1,2,4,5-cyclohexanetetracarboxylic dianhydride.

In the first compound, the average proportion of skeletons derived from an acid dianhydride (third acid dianhydride) that does not have the norbornane skeleton and does not have a phthalimide skeleton in 100 mol% of skeletons derived from all acid dianhydrides is preferably 5 mol% or more, more preferably 10 mol% or more, and even more preferably 20 mol% or more. In the first compound, the average proportion of skeletons derived from an acid dianhydride (third acid dianhydride) that does not have the norbornane skeleton and does not have a phthalimide skeleton in 100 mol% of skeletons derived from all acid dianhydrides is preferably 70 mol% or less, more preferably 60 mol% or less, and even more preferably 50 mol% or less. When the average proportion of skeletons derived from the third acid dianhydride is the above lower limit or more and the above upper limit or less, the effect of the present invention can be more effectively exhibited.

It is preferable that the first compound has a skeleton derived from an aliphatic diamine compound. In this case, 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 aliphatic diamine compound preferably has a cyclohexane skeleton, preferably has a polycyclic skeleton, and more preferably has a tricyclodecane skeleton or a norbornane skeleton. That is, the first compound preferably has a skeleton derived from an aliphatic diamine compound having a cyclohexane skeleton (aliphatic diamine compound containing a cyclohexane skeleton). The first compound preferably has a skeleton derived from an aliphatic diamine compound having a polycyclic skeleton (aliphatic diamine compound containing a polycyclic skeleton). It is more preferable that the first compound has a skeleton derived from an aliphatic diamine compound having a tricyclodecane skeleton (aliphatic diamine compound containing a tricyclodecane skeleton). It is more preferable that the first compound has a skeleton derived from an aliphatic diamine compound having a norbornane skeleton (aliphatic diamine compound containing a norbornane skeleton). In these cases, the dielectric tangent of the cured product can be further lowered, and the thermal dimensional stability of the cured product can be further improved.

A polycyclic skeleton refers to a structure having multiple ring skeletons in succession. Specifically, a polycyclic skeleton is a skeleton in which two or more rings are integrated by sharing two or more atoms, and is a skeleton having condensed rings. The above polycyclic skeleton is not, for example, a skeleton in which an alkylene group exists between two rings.

The polycyclic skeleton preferably contains a cyclohexane skeleton. Examples of the polycyclic skeleton containing the cyclohexane skeleton include a tricyclodecane skeleton, a norbornane skeleton, and an adamantane skeleton. The polycyclic skeleton containing the cyclohexane skeleton may be a tricyclodecane skeleton.

For example, the tricyclodecane skeleton in the first compound may be a skeleton represented by the following formula (11). In the following formula (11), the right end and the left end are bonding sites with other groups.

The above aliphatic diamine compounds include dimer diamine, tricyclodecane diamine, 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, 1,3-cyclohexanediamine, 1,4-cyclohexanediamine, isophoronediamine, 4,4'-methylenebis(cyclohexylamine), and 4,4'-methylenebis(2-methylcyclohexylamine). The above aliphatic diamine compounds may be used alone or in combination of two or more.

From the viewpoint of further reducing the dielectric tangent of the cured product, it is preferable that the first compound has a skeleton derived from dimer diamine. The skeleton derived from the dimer diamine is a flexible skeleton. Therefore, when the first compound has a skeleton derived from the dimer diamine, the sheet properties of a resin film such as a B-stage film can be improved. In addition, since the stress relaxation property of the cured product can be improved, the occurrence of warping can be effectively suppressed, and the reliability of a multilayer printed wiring board, etc. can be improved.

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).

In the first compound, the average proportion of the skeleton derived from the 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, even more preferably 25 mol% or more, preferably 90 mol% or less, more preferably 70 mol% or less, and even more preferably 50 mol% or less. When the average proportion of the skeleton derived from the dimer diamine is equal to or less than the upper limit, the dielectric tangent of the cured product can be further reduced, and the flexibility of the resin film can be increased. When the average proportion of the skeleton derived from the dimer diamine is equal to or more than the lower limit, the linear expansion coefficient can be kept low, and smears can be more effectively removed by desmearing, and the compatibility of the resin material can be further increased.

From the viewpoint of exerting the effects of the present invention more effectively, it is preferable that the first compound has an aromatic ring. The first compound may have only one aromatic ring or may have multiple aromatic rings. The first compound may have the aromatic ring derived from an aromatic diamine compound. The first compound may have a skeleton derived from an aromatic diamine compound.

In order to further reduce the dielectric tangent of the cured product and to increase the thermal dimensional stability of the cured product, the first compound has a structural unit having an imide bond as a repeating structural unit.

The structural unit having the imide bond may include a skeleton derived from an acid dianhydride having a norbornane skeleton (first acid dianhydride). The structural unit having the imide bond may include a skeleton derived from an acid dianhydride having no norbornane skeleton and a phthalimide skeleton (second acid dianhydride). The structural unit having the imide bond may include a skeleton derived from an acid dianhydride having no norbornane skeleton and a phthalimide skeleton (third acid dianhydride).

The first compound preferably has a maleimide skeleton or a benzoxazine skeleton, more preferably has a maleimide skeleton or a benzoxazine skeleton at the terminal, and even more preferably has a maleimide skeleton or a benzoxazine skeleton at both terminals. From the viewpoint of setting the curing temperature at 200°C or less, it is particularly preferable that the first compound is a bismaleimide compound.

The molecular weight of the first compound is more than 1000, preferably 1500 or more, more preferably 3000 or more, even more preferably 3100 or more, preferably 50000 or less, more preferably 20000 or less, even more preferably 10000 or less, and particularly preferably 7000 or less. When the molecular weight of the first compound is equal to or more than the above lower limit and equal to or less than the above upper limit, the effects of the present invention can be more effectively exhibited.

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

The content of the first compound in 100% by weight of the components in the resin material excluding the filler and the solvent is preferably 5% by weight or more, more preferably 10% by weight or more, even more preferably 12% by weight or more, particularly preferably 15% by weight or more, preferably 40% by weight or less, and more preferably 30% by weight or less. When the content of the first compound is equal to or more than the lower limit and equal to or less than the upper limit, the effects of the present invention can be more effectively exhibited.

The content of the first compound is preferably 20% by weight or more, more preferably 40% by weight or more, preferably 80% by weight or less, more preferably 70% by weight or less, out of a total of 100% by weight of the content of the first compound and the content of the second compound. When the content of the first compound is equal to or more than the lower limit and equal to or less than the upper limit, the effect of the present invention can be more effectively exhibited.

[Second Compound]
The resin material according to the present invention includes a second compound having an aromatic skeleton. The second compound does not have a structural unit having an imide skeleton as a repeating structural unit. The second compound is a thermosetting compound. Only one type of the second compound may be used, or two or more types may be used in combination.

Examples of the second compound include maleimide compounds, epoxy compounds, cyanate compounds, vinyl compounds, phenoxy compounds, oxetane compounds, polyarylate compounds, diallyl phthalate compounds, episulfide compounds, (meth)acrylic compounds, amino compounds, unsaturated polyester compounds, polyurethane compounds, and silicone compounds.

The second compound preferably contains a maleimide compound, an epoxy compound, or a vinyl compound, more preferably contains a maleimide compound or an epoxy compound, and even more preferably contains an epoxy compound.

The molecular weight of the second compound is preferably 1000 or less, more preferably 900 or less, even more preferably 800 or less, and particularly preferably 700 or less. The molecular weight of the second compound is preferably 100 or more, more preferably 200 or more. When the molecular weight of the second compound is equal to or greater than the lower limit and equal to or less than the upper limit, the effects of the present invention can be more effectively exhibited. Furthermore, when the molecular weight of the second compound is equal to or less than the upper limit, the embedding ability of the resin material into unevenness of a substrate, etc., and the flexibility of the B-stage film can be improved.

The second compound preferably includes a compound having a molecular weight of 1000 or less, more preferably includes a compound having a molecular weight of 900 or less, even more preferably includes a compound having a molecular weight of 800 or less, and particularly preferably includes a compound having a molecular weight of 700 or less. It is also preferable that the second compound includes a compound having a molecular weight of 1000 or less and a compound having a molecular weight of more than 1000. In this case, the effect of the present invention can be exerted even more effectively.

The resin material preferably contains a second compound having a molecular weight of 1000 or less, more preferably contains a second compound having a molecular weight of 900 or less, even more preferably contains a second compound having a molecular weight of 800 or less, and particularly preferably contains a second compound having a molecular weight of 700 or less. In this case, the effect of the present invention can be exerted even more effectively.

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

<Maleimide Compound>
The maleimide compound as the second compound is a maleimide compound having an aromatic skeleton. The maleimide compound as the second compound is a maleimide compound having no structural unit having an imide skeleton as a repeating structural unit. Only one type of the maleimide compound may be used, or two or more types may be used in combination.

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

Commercially available maleimide compounds, which are the second compounds, include, for example, "BMI-2300," "BMI-4000," and "BMI-5100" manufactured by Daiwa Kasei Kogyo Co., Ltd., and "MIR-3000" manufactured by Nippon Kayaku Co., Ltd.

The content of the maleimide compound, which is the second compound, in 100% by weight of the components in the resin material excluding the filler and the solvent is preferably 1% by weight or more, more preferably 2% by weight or more, even more preferably 3% by weight or more, and preferably 50% by weight or less. When the content of the maleimide 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.

<Epoxy Compound>
The epoxy compound, which is the second compound, is an epoxy compound having an aromatic skeleton. The epoxy compound, which is the second compound, is an epoxy compound that does not have a structural unit having an imide skeleton as a repeating structural unit. 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 resin material may contain both an epoxy compound as the second compound and an epoxy compound as the thermosetting compound X described below. When the resin material contains the second compound other than an epoxy compound, the resin material may not contain the epoxy compound as the second compound, and may contain an epoxy compound as the thermosetting compound X described below.

Examples of the epoxy compound that is the second compound 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, anthracene type epoxy compounds, and naphthylene ether type epoxy compounds.

The second compound, that is, 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 of the cured product and improving the thermal dimensional stability and flame retardancy of the cured product, it is preferable that the epoxy compound, which is the second compound, contains an epoxy compound having a naphthalene skeleton or a phenyl skeleton.

From the viewpoint of further lowering the dielectric tangent of the cured product and improving the coefficient of linear expansion (CTE) of the cured product, it is preferable that the epoxy compound, which is the second 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, which is the second compound, can be measured, for example, using a dynamic viscoelasticity measuring device ("VAR-100" manufactured by Rheologica Instruments).

From the viewpoint of further enhancing the thermal dimensional stability of the cured product, the content of the epoxy compound, which is the second compound, in 100% by weight of the components excluding the solvent in the resin material is preferably 3% by weight or more, more preferably 6% by weight or more, and preferably 15% by weight or less, more preferably 12% by weight or less.

The content of the epoxy compound, which is the second compound, in 100% by weight of the components in the resin material excluding the filler and the solvent is preferably 10% by weight or more, more preferably 20% by weight or more, preferably 50% by weight or less, more preferably 40% by weight or less. When the content of the epoxy 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.

<Vinyl Compounds>
The vinyl compound, which is the second compound, is a vinyl compound having an aromatic skeleton. The vinyl compound, which is the second compound, is a vinyl compound that does not have a structural unit having an imide skeleton as a repeating structural unit. As the vinyl compound, a conventionally known vinyl compound can be used. The vinyl compound may be used alone or in combination of two or more kinds.

Examples of the vinyl compound that is the second compound include a styrene compound, an acrylate compound, and a divinyl compound. Examples of the divinyl compound include a divinyl benzyl ether compound. The vinyl compound may be a divinyl compound having an aliphatic skeleton or a divinyl ether compound.

An example of a commercially available product of the second compound, a vinyl compound (styrene compound), is "OPE-2St" manufactured by Mitsubishi Gas Chemical Company, Inc.

The resin material may contain both a vinyl compound as the second compound and a vinyl compound as the thermosetting compound X described below. When the resin material contains the second compound other than a vinyl compound, the resin material may not contain the vinyl compound as the second compound, and may contain a vinyl compound as the thermosetting compound X described below.

The content of the vinyl compound, which is the second compound, in 100% by weight of the components in the resin material excluding the filler and the solvent 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 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.

[Thermosetting compound other than the second compound (thermosetting compound X)]
The resin material according to the present invention preferably contains a thermosetting compound other than the second compound (hereinafter, sometimes referred to as a thermosetting compound X). The thermosetting compound X is different from the second compound. The thermosetting compound X is different from the first compound. The thermosetting compound X is a thermosetting compound that does not have an aromatic skeleton, or a thermosetting compound that has a structural unit having an imide bond as a repeating structural unit. The thermosetting compound X may be used alone or in combination of two or more kinds.

Examples of the thermosetting compound X include maleimide compounds, epoxy compounds, cyanate compounds, vinyl compounds, phenoxy compounds, oxetane compounds, polyarylate compounds, diallyl phthalate compounds, episulfide compounds, (meth)acrylic compounds, amino compounds, unsaturated polyester compounds, polyurethane compounds, and silicone compounds.

The thermosetting compound X preferably contains a maleimide compound, an epoxy compound, or a vinyl compound, more preferably contains a maleimide compound or an epoxy compound, and even more preferably contains an epoxy compound.

Examples of the epoxy compound that is the thermosetting compound X include an epoxy compound having an adamantane skeleton and an epoxy compound having a tricyclodecane skeleton.

Commercially available epoxy compounds that are the thermosetting compound X include, for example, "PB3600" (polybutadiene-based backbone epoxy resin) manufactured by Daicel Corporation and "Foldi E101" manufactured by Nissan Chemical Industries, Ltd.

Commercially available products of the maleimide compound, which is the thermosetting compound X, include, for example, "BMI-3000" and "BMI-689" manufactured by Designer Molecules Inc.

The content of the thermosetting compound X in 100% by weight of the components in the resin material excluding the filler and the solvent is preferably 1% by weight or more, more preferably 3% by weight or more, even more preferably 5% by weight or more, preferably 50% by weight or less, and more preferably 30% by weight or less. When the content of the thermosetting compound X is equal to or more than the lower limit and equal to or less than the upper limit, the flexibility of the cured product can be further increased. In addition, when the content of the thermosetting 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 increased.

[Filling material]
The resin material preferably contains a filler.

The filler may be an organic filler or an inorganic filler. The filler is preferably an insulating filler. Only one type of the filler may be used, or two or more types may be used in combination.

The organic filler may be a particulate material made of benzoxazine resin, benzoxazole resin, fluororesin, acrylic resin, styrene resin, or the like. The fluororesin may be polytetrafluoroethylene (PTFE), or the like. By using fluororesin particles as the organic filler, the relative dielectric constant and dielectric tangent of the cured product of the resin material can be further reduced.

The inorganic fillers include silica, talc, clay, mica, hydrotalcite, alumina, magnesium oxide, aluminum hydroxide, aluminum nitride, boron nitride, and diamond.

From the viewpoint of further reducing the dielectric tangent of the cured resin material and further reducing the dimensional change due to heat of the cured resin material, it is preferable that the filler is an inorganic filler. It is preferable that the resin material contains an inorganic filler.

The inorganic filler is preferably an inorganic filler with a thermal conductivity of 10 W/mK or more, such as alumina or boron nitride. In this case, heat dissipation can be improved.

From the viewpoint of improving thermal dimensional stability, it is preferable that the inorganic filler is an anisotropic inorganic filler.

The inorganic filler is preferably silica or alumina, more preferably silica, and even more preferably fused silica. In this case, the surface roughness of the surface of the cured resin material is reduced, the adhesive strength between the cured resin material and the metal layer is further increased, finer wiring is formed on the surface of the cured resin material, and the cured resin material has better insulation reliability. In particular, by using silica as the inorganic filler, the thermal expansion coefficient of the cured resin material is further reduced, and the dielectric tangent of the cured resin material is further reduced. In addition, the dielectric constant of the cured resin material can be improved. The silica is preferably spherical in shape.

From the viewpoint of increasing thermal conductivity and insulating properties, it is preferable that the inorganic filler be alumina.

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 organic filler preferably has an average particle size of 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 average particle size of the inorganic filler is preferably 50 nm or more, more preferably 100 nm or more, and even more preferably 500 nm or more, and is 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 more than the above lower limit and equal to or less than the above 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 filler. The average particle size can be measured using a laser diffraction scattering particle size distribution measuring device.

The content of the filler in 100% by weight of the components excluding the solvent in the resin material is preferably 50% by weight or more, more preferably 55% by weight or more, even more preferably 60% by weight or more, particularly preferably 70% by weight or more, and preferably 90% by weight or less, more preferably 85% by weight or less, even more preferably 80% by weight or less, particularly preferably 75% by weight or less. When the content of the filler is equal to or greater than the lower limit, the dielectric tangent is effectively lowered. When the content of the 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 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.

The content of the organic filler in 100% by weight of the components excluding the solvent in the resin material is preferably 5% by weight or more, more preferably 10% by weight or more, even more preferably 15% by weight or more, particularly preferably 20% by weight or more, and preferably 75% by weight or less, more preferably 60% by weight or less, even more preferably 50% by weight or less, particularly preferably 40% by weight or less. When the content of the organic filler is equal to or greater than the lower limit, the dielectric tangent is effectively lowered. When the content of the organic 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 organic 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.

The content of the inorganic filler in 100% by weight of the components excluding the solvent in the resin material 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. 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, a carbodiimide compound (carbodiimide curing agent), an amine compound (amine curing agent), a thiol compound (thiol curing agent), a phosphine compound, a 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 increasing 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 carbodiimide compound, and an acid anhydride. From the viewpoint of further increasing 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, and a carbodiimide compound, it is even more preferable that the curing agent contains an active ester compound, and it is particularly 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 a phenol compound and an active ester 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 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. Only one type of the carbodiimide compound may be used, or two or more types may be used in combination.

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 Co., Ltd., as well as "Stavaxol P", "Stavaxol P400", and "Hi-Kasil 510" manufactured by Rhein Chemie.

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 first compound, the second compound, the thermosetting compound X, and the curing agent in the resin material (100% by weight, excluding the filler and the solvent) is preferably 50% by weight or more, more preferably 60% by weight or more, and preferably 95% by weight or less. When the total content is equal to or more than the lower limit and equal to or less than the upper limit, the curability 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 a conventionally known curing accelerator 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. Limellitate, 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 bis(II) acetylacetonate, and cobalt tris(III) acetylacetonate.

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 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 kinds.

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 prevents the resin film from becoming less able to fill holes or irregularities in the circuit board and prevents the inorganic filler from becoming non-uniform. 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 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)diphenylsulfonate, and 4,4'-bis(3,4-dicarboxyphenoxy)diphenylsulfonate. sulfide 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), 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.

[Elastomer]
The resin material does not contain or contains an elastomer. The use of the elastomer can increase the flexibility of the B-stage film and the flexibility of the cured product. The elastomer may have a thermosetting functional group.

Examples of the elastomer include elastomers having a polybutadiene structure, elastomers having a polysiloxane structure, elastomers having a polyisoprene structure, elastomers having a polyisobutylene structure, and elastomers having a polyalkylene structure.

[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 above-mentioned resin material may contain 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.

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 resin composition described above is molded into a film to obtain a resin film (B-stage product/B-stage film). The 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 for 1 to 10 minutes at, for example, 50°C to 150°C 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.

(Other details of resin material)
The resin material is heated at 130°C for 60 minutes to be temporarily cured, and then heated at 200°C for 90 minutes to obtain a cured product of the resin material. In this case, the dielectric loss tangent (Df) of the obtained cured product at 23°C and a frequency of 5.8 GHz is preferably 3.0 x ^10-3 or less, more preferably 2.8 x ^10-3 or less, even more preferably 2.5 x ^10-3 or less, and particularly preferably 2.3 x ^10-3 or less. The dielectric loss tangent (Df) of the cured product may be 1.5 x ^10-3 or more, or may be 1.8 x ^10-3 or more.

More specifically, the dielectric loss tangent (Df) of the cured product is measured as follows:

The film-like resin material (resin film) is heated at 130°C for 60 minutes to provisionally cure, and then heated at 200°C for 90 minutes to obtain a cured resin material. The resulting cured material is cut into pieces 2 mm wide and 80 mm long, and 10 pieces are stacked together. The dielectric tangent is 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.

The resin material is heated at 130°C for 60 minutes to be provisionally cured, and then heated at 200°C for 90 minutes to obtain a cured resin material. In this case, the average coefficient of linear expansion (CTE) from 25°C to 150°C under a tensile load of 33 mN of the obtained cured product is preferably 33 ppm/°C or less, more preferably 30 ppm/°C or less, even more preferably 27 ppm/°C or less, particularly preferably 24 ppm/°C or less, and most preferably 22 ppm/°C or less. The average coefficient of linear expansion (CTE) of the cured product may be 17 ppm/°C or more, or may be 19 ppm/°C or more.

More specifically, the average coefficient of linear expansion (CTE) of the cured product is measured as follows:

The film-like resin material (resin film) is heated at 130°C for 60 minutes to provisionally cure, and then heated at 200°C for 90 minutes to obtain a cured resin material. The resulting cured material is cut into pieces measuring 3 mm x 25 mm. Using a thermomechanical analyzer (e.g., "EXSTAR TMA/SS6100" manufactured by SII Nanotechnology Inc.), the average linear expansion coefficient (ppm/°C) of the cut cured material from 25°C to 150°C is calculated under conditions of a tensile load of 33 mN and a heating rate of 5°C/min.

(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 suitable for use as an alternative to liquid crystal polymer (LCP), for use as a millimeter wave antenna, and for use as a rewiring layer. The above resin material is also suitable for use in wiring formation in general, not limited to the above uses.

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 of the resin film can be laminated. 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 having 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 plurality of 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, a plurality of insulating layers 13-16 are laminated on the upper surface 12a of the circuit board 12. The insulating layers 13-16 are cured layers. A metal layer 17 is formed on a partial area of the upper surface 12a of the circuit board 12. Of the plurality of 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 a cured product of the above-mentioned 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 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:

(First Compound)
The first compound (molecular weight: 4000) was synthesized according to Synthesis Example 1 below.
The first compound (molecular weight: 4600) was synthesized according to Synthesis Example 2 below.

<Synthesis Example 1>
115 g of toluene, 35 g of N-methyl-2-pyrrolidone (NMP), 8.7 g of dimer diamine ("Priamine 1075" manufactured by Croda Japan Co., Ltd.), and 10.00 g of norbornane diamine ("Pro-NBDA" manufactured by Mitsui Fine Chemicals Co., Ltd.) were placed in a 500 mL three-neck flask and stirred. Next, 3.0 g of methanesulfonic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) was placed in the three-neck flask and stirred using a stirring rod with a three-one motor. In addition, a mixture of 7.78 g of 4,4'-biphthalic anhydride (manufactured by Tokyo Chemical Industry Co., Ltd.) and 7.99 g of D NDA (manufactured by DAXIN MATERIALS Co., Ltd.) was obtained. The obtained mixture was placed in the three-neck flask and stirred. Next, a reflux tube with a Dean-Stark tube was attached to one of the necks of the three-neck flask, and the temperature was set to 130°C in an oil bath, and the mixture was refluxed for 4 hours while stirring. Next, 6.22 g of maleic anhydride (Tokyo Chemical Industry Co., Ltd.) was placed in the three-neck flask and refluxed for 4 hours. After refluxing, the organic layer was washed three times with a mixed solvent of water and ethanol to obtain an organic layer in which the maleimide compound was dissolved. After distilling off the water and ethanol from the organic layer, the organic layer was slowly dropped into 2 L of methanol, and reprecipitation was performed to obtain a solid content. The solid content was collected by suction filtration and dried in a vacuum oven to obtain a product (yield 80%).

<Synthesis Example 2>
115 g of toluene, 35 g of N-methyl-2-pyrrolidone (NMP), 8.7 g of dimer diamine ("Priamine 1075" manufactured by Croda Japan Co., Ltd.), and 10.00 g of norbornane diamine ("Pro-NBDA" manufactured by Mitsui Fine Chemicals Co., Ltd.) were placed in a 500 mL three-neck flask and stirred. Next, 3.0 g of methanesulfonic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) was placed in the three-neck flask and stirred using a stirring rod with a three-one motor. In addition, a mixture of 5.77 g of pyromellitic dianhydride (manufactured by Tokyo Chemical Industry Co., Ltd.) and 10.7 g of BzDA (manufactured by JXTG Corporation) was obtained. The resulting mixture was placed in the three-neck flask and stirred. Next, a reflux tube with a Dean-Stark tube was attached to one of the necks of the three-neck flask, the temperature was set to 130 ° C. of an oil bath, and the mixture was refluxed for 4 hours while stirring. Next, 6.22 g of maleic anhydride (Tokyo Chemical Industry Co., Ltd.) was placed in a three-neck flask and refluxed for 4 hours. After refluxing, the organic layer was washed three times with a mixed solvent of water and ethanol to obtain an organic layer in which the maleimide compound was dissolved. After distilling off the water and ethanol from the organic layer, the organic layer was slowly dropped into 2 L of methanol to perform reprecipitation and obtain a solid content. The solid content was collected by suction filtration and dried in a vacuum oven to obtain a product (yield 78%).

(Second Compound)
Resorcinol diglycidyl ether ("EX-201" manufactured by Nagase ChemteX Corporation, molecular weight: 1000 or less)
Biphenyl type epoxy compound ("NC-3000H" manufactured by Nippon Kayaku Co., Ltd.: molecular weight: over 1000)
Naphthalene-type epoxy compound ("ESN-475V" manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.: molecular weight: over 1000)
Epoxy compound having an amino group ("630" manufactured by Mitsubishi Chemical Corporation, molecular weight: 1000 or less)
Phenylene ether skeleton-containing styrene compound ("OPE-2St-2200" manufactured by Mitsubishi Gas Chemical Company, Inc., molecular weight: over 1000)

(Thermosetting compound X)
Epoxy compound having a butadiene skeleton ("PB3600" manufactured by Daicel Corporation, molecular weight 5900)
Hyperbranched aliphatic epoxy compound (Nissan Chemical Industries, Ltd. "Foldi E101", molecular weight: 1000 or less)
Hydrogenated bisphenol A diglycidyl ether (Nagase Chemtex Corporation "EX-252", molecular weight: 1000 or less)
Maleimide compound 1 ("BMI-689" manufactured by Designer Molecules Inc.: molecular weight of 1000 or less)
Maleimide compound 2 (N-alkyl bismaleimide compound, "BMI-1700" manufactured by Designer Molecules Inc.)
Maleimide Compound 3 (Synthesized according to Synthesis Example 3 below: molecular weight 4100)
Maleimide Compound 4 (Synthesized according to Synthesis Example 4 below: molecular weight 4700)

<Synthesis Example 3>
115 g of toluene, 35 g of N-methyl-2-pyrrolidone (NMP), 8.7 g of dimer diamine ("Priamine 1075" manufactured by Croda Japan Co., Ltd.), and 10.00 g of norbornane diamine ("Pro-NBDA" manufactured by Mitsui Fine Chemicals Co., Ltd.) were placed in a 500 mL three-neck flask and stirred. Next, 3.0 g of methanesulfonic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) was placed in the three-neck flask and stirred using a stirring rod with a three-one motor. In addition, a mixed solution with 11.5 g of pyromellitic dianhydride (manufactured by Tokyo Chemical Industry Co., Ltd.) was obtained. The resulting mixed solution was placed in the three-neck flask and stirred. Next, a reflux tube with a Dean-Stark tube was attached to one of the necks of the three-neck flask, the temperature was set to 130 ° C. of an oil bath, and the mixture was refluxed for 4 hours while stirring. Next, 6.22 g of maleic anhydride (Tokyo Chemical Industry Co., Ltd.) was placed in a three-neck flask and refluxed for 4 hours. After refluxing, the organic layer was washed three times with a mixed solvent of water and ethanol to obtain an organic layer in which the maleimide compound was dissolved. After distilling off the water and ethanol from the organic layer, the organic layer was slowly dropped into 2 L of methanol to perform reprecipitation and obtain a solid content. The solid content was collected by suction filtration and dried in a vacuum oven to obtain a product (yield 75%).

<Synthesis Example 4>
115 g of toluene, 35 g of N-methyl-2-pyrrolidone (NMP), 8.7 g of dimer diamine ("Priamine 1075" manufactured by Croda Japan Co., Ltd.), and 10.00 g of norbornane diamine ("Pro-NBDA" manufactured by Mitsui Fine Chemicals Co., Ltd.) were placed in a 500 mL three-neck flask and stirred. Next, 3.0 g of methanesulfonic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) was placed in the three-neck flask and stirred using a stirring rod with a three-one motor. In addition, a mixed solution with 14.0 g of 5-(2,5-dioxotetrahydrofuryl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride (manufactured by Tokyo Chemical Industry Co., Ltd.) was obtained. The resulting mixed solution was placed in the three-neck flask and stirred. Next, a reflux tube with a Dean-Stark tube was attached to one of the necks of the three-neck flask, and the temperature was set to 130°C in an oil bath, and the mixture was refluxed for 4 hours while stirring. Next, 6.22 g of maleic anhydride (Tokyo Chemical Industry Co., Ltd.) was placed in the three-neck flask and refluxed for 4 hours. After refluxing, the organic layer was washed three times with a mixed solvent of water and ethanol to obtain an organic layer in which the maleimide compound was dissolved. After distilling off the water and ethanol from the organic layer, the organic layer was slowly dropped into 2 L of methanol, and reprecipitation was performed to obtain a solid content. The solid content was collected by suction filtration and dried in a vacuum oven to obtain a product (yield 82%).

(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 liquid (DIC Corporation "HPC-8000L-65T", solid content 65% 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 5 below.

<Synthesis Example 5>
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.

Except for compounds whose structural formulas cannot be determined, the molecular weights of the first and second compounds and the polyimide compound synthesized in Synthesis Example 5 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.

(Examples 1 to 3 and Comparative Examples 1 to 4)
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 10 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) Compatibility of Resin Materials The obtained resin film was vacuum laminated onto a CCL substrate ("E679FG" manufactured by Hitachi Chemical Co., Ltd.), and semi-cured by heating at 130° C. for 30 minutes and then at 170° C. for 30 minutes. In this way, a laminate in which a semi-cured resin film was laminated onto a CCL substrate was obtained.

The gloss of the laminate was measured using a handheld gloss meter (HORIBA's IG-331). Note that the higher the gloss, the higher the compatibility of the resin material and the better the fluidity. The lower the gloss, the lower the compatibility of the resin material, and the resin material may have undergone phase separation or the fluidity of the inorganic filler (silica) may have decreased.

[Criteria for determining compatibility of resin materials]
◯: Glossiness is 90 or more △: Glossiness is 80 or more and less than 90 ×: Glossiness is less than 80

(2) Surface roughness after etching <Swelling treatment>
The laminate obtained in "(1) Compatibility of resin materials" 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.

<Permanganate treatment (roughening treatment and desmear treatment)>
The laminate 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 swung for 30 minutes. Next, the laminate 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.

<Surface roughness measurement>
On the surface of the evaluation sample (roughened cured product), 10 areas of 94 μm × 123 μm were arbitrarily selected. For each of the 10 areas, the arithmetic mean roughness Ra was measured using a non-contact three-dimensional surface profiler (Veeco's "WYKO NT1100"). The following surface roughness was evaluated from the average value of the arithmetic mean roughness Ra measured at the 10 points, and the following surface roughness uniformity was evaluated from the absolute value of the difference between the maximum and minimum values of the arithmetic mean roughness Ra measured at the 10 points. The arithmetic mean roughness Ra was measured in accordance with JIS B0601:1994.

[Criteria for surface roughness after etching]
◯: The average value of the arithmetic mean roughness Ra is less than 70 nm Δ: The average value of the arithmetic mean roughness Ra is 70 nm or more and less than 150 nm ×: The average value of the arithmetic mean roughness Ra is 150 nm or more

(3) Embeddability into uneven surface Only the copper foil of a 100 mm square copper-clad laminate (a laminate of a 400 μm thick glass epoxy substrate and a 25 μm thick copper foil) was etched to open dents (openings) with a diameter of 100 μm and a depth of 25 μm in a straight line across a 30 mm square area in the center of the substrate, with the distance between the centers of adjacent holes being 900 μm. In this way, an evaluation substrate with a total of 900 dents was prepared.

The resin film side of the obtained laminated film was placed on the evaluation substrate, and heated and pressed at a lamination pressure of 0.4 MPa for 20 seconds, a press pressure of 0.8 MPa for 20 seconds, and a lamination and press temperature of 90°C using a Meiki Seisakusho batch vacuum laminator MVLP-500-IIA. After cooling to room temperature, the PET film was peeled off. In this way, an evaluation sample was obtained in which a resin film was laminated on an evaluation substrate.

The obtained evaluation samples were observed using an optical microscope to observe voids in the depressions. The percentage of depressions in which voids were observed was evaluated to determine the embeddability of the sample against an uneven surface according to the following criteria.

[Criteria for embeddability on uneven surfaces]
○: The percentage of depressions in which voids were observed was 0%.
△: The ratio of depressions in which voids were observed was more than 0% and less than 5%. ×: The ratio of depressions in which voids were observed was 5% or more.

(4) Dielectric loss tangent The obtained resin film was heated at 130° C. for 60 minutes to be provisionally cured, and then heated at 200° 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 was measured at room temperature (23° C.) and a frequency of 5.8 GHz by the cavity resonance method using a "Cavity Resonance Perturbation Dielectric Constant Measurement Apparatus 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 loss tangent is less than 2.3×10 ⁻³ △: Dielectric loss tangent is 2.3×10 ⁻³ or more and less than 2.5×10 ⁻³ ×: Dielectric loss tangent is 2.5×10 ⁻³ or more

(5) Thermal dimensional stability (average coefficient of linear expansion (CTE))
The resulting 40 μm thick resin film (B-stage film) was temporarily cured by heating at 130° C. for 60 minutes, and then heated at 200° C. for 90 minutes to obtain a cured product, which was then cut into pieces measuring 3 mm×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 (SII NanoTechnology Inc., “EXSTAR TMA/SS6100”) 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 27 ppm/°C or less ×: Average linear expansion coefficient is more than 27 ppm/°C

(6) Glass transition temperature (Tg)
The obtained resin film (B-stage film) having a thickness of 40 μm was heated at 130° C. for 60 minutes to be temporarily cured, and then heated at 200° C. for 90 minutes to obtain a cured product, which was then cut into pieces having a size of 5 mm×25 mm. Measurements were performed using a thermomechanical analyzer (SII NanoTechnology'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 (Tg)]
◯: Glass transition temperature exceeds 180° C. △: Glass transition temperature exceeds 170° C. and is equal to or lower than 180° C. ×: Glass transition temperature is equal to or lower than 170° C.

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 layers

Claims (15)

a first compound having a skeleton derived from an acid dianhydride having a norbornane skeleton;
a second compound having an aromatic skeleton ; and
and an inorganic filler ,
the first compound has a structural unit having an imide bond as a repeating structural unit,
the second compound does not have a structural unit having an imide skeleton as a repeating structural unit,
The molecular weight of the first compound is greater than 1000;
the second compound is a thermosetting compound;
A resin material used to form an insulating layer in a multilayer printed wiring board . The resin material according to claim 1, wherein the molecular weight of the second compound is 1000 or less. The resin material according to claim 1 or 2, wherein the first compound has an aromatic ring. The resin material according to any one of claims 1 to 3, wherein the first compound has a skeleton derived from an acid dianhydride that does not have a norbornane skeleton and has a phthalimide skeleton. The resin material according to any one of claims 1 to 4, wherein the first compound has a skeleton derived from an aliphatic diamine compound. The resin material according to any one of claims 1 to 5, wherein the first compound has a skeleton derived from an aliphatic diamine compound having a cyclohexane skeleton. The resin material according to any one of claims 1 to 6, wherein the first compound has a skeleton derived from dimer diamine. The resin material according to claim 7, wherein in the first compound, the average proportion of the skeleton derived from the dimer diamine is 10 mol % or more and 90 mol % or less out of 100 mol % of the skeleton derived from all diamine compounds. The resin material according to any one of claims 1 to 8, wherein the first compound has a maleimide skeleton or a benzoxazine skeleton. The resin material according to any one of claims 1 to 9, wherein the first compound has a skeleton derived from an acid dianhydride that does not have a norbornane skeleton and does not have a phthalimide skeleton. The resin material according to any one of claims 1 to 10, wherein the molecular weight of the first compound is 50,000 or less. The resin material according to any one of claims 1 to 11, wherein the second compound includes an epoxy compound. Contains a hardener,
The resin material according to any one of claims 1 to 12 , wherein the curing agent comprises an active ester compound. The resin material according to any one of claims 1 to 13 , which is a resin film. 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 14 .

Images