CN109072018B - Adhesive film for multilayer printed wiring board - Google Patents

Abstract

The invention provides an adhesive film for a multilayer printed wiring board, which has excellent embedding performance of concave and convex even if the filling of silica filler is high. Specifically disclosed is an adhesive film for a multilayer printed wiring board, which comprises a resin composition layer formed by layering a resin composition on a support film, wherein the resin composition comprises (A) a phenol novolac resin having a dispersion ratio (Mw/Mn) of a weight average molecular weight (Mw) to a number average molecular weight (Mn) of 1.05-1.8, (B) an epoxy resin represented by general formula (1), and (C) an inorganic filler, the average particle diameter of the inorganic filler (C) in the resin composition layer is 0.1 [ mu ] m or more, and the content of the inorganic filler (C) is 20-95 mass% of the solid resin component.

Description

Adhesive film for multilayer printed wiring board

Technical Field

The present invention relates to an adhesive film for a multilayer printed wiring board.

Background

In recent years, there has been a strong demand for a multilayer printed wiring board used in electronic devices, communication devices, and the like, which has been made smaller, lighter, and has higher density of wiring, and which has also been made faster in arithmetic processing speed. In response to this demand, attention is being paid to a multilayer manufacturing technique in which interlayer insulating layers are alternately deposited on wiring layers of a circuit board as a method for manufacturing a multilayer printed wiring board.

In the manufacturing technique of the build-up method, as a method for manufacturing the interlayer insulating layer and the wiring layer, a conventional method has been to form the wiring by a so-called "subtractive method" in which: the resin composition for interlayer insulation layer formation (hereinafter also referred to as "resin composition for interlayer insulation layer") and the pressing apparatus for copper foil for wiring layer formation are pressed at high temperature for a long time to thermally cure the resin composition for interlayer insulation layer to obtain an interlayer insulation layer having a copper foil, then via holes for interlayer connection (japanese: ビアホール) are formed using a drilling method, a laser method, or the like as necessary, and then the copper foil is removed by etching to leave necessary portions.

In addition, with the above-described demands for downsizing, weight saving, and high density of wiring of multilayer printed wiring boards, attention is being paid to a so-called "additive process" which is: the resin composition for an interlayer insulating layer and the copper foil are pressed in a vacuum laminator at a high temperature for a short time, and then the resin composition for an interlayer insulating layer is thermally cured at a high temperature by a dryer or the like, via holes for interlayer connection are formed by a drilling method, a laser method or the like as needed, and a wiring layer is formed at a necessary portion by a plating method.

As the resin composition for an interlayer insulating layer used in the lamination system, an organic insulating resin obtained by combining an aromatic epoxy resin and a curing agent having active hydrogen with respect to the epoxy resin (for example, a phenol curing agent, an amine curing agent, a carboxylic acid curing agent, and the like) is mainly used. A cured product obtained by curing the epoxy resin using these curing agents has an excellent balance in physical properties, but has a problem that a hydroxyl group having high polarity is generated by a reaction between an epoxy group and active hydrogen, and thus, electrical characteristics such as a water absorption rate increase, a relative dielectric constant, and a dielectric loss tangent are lowered. In addition, when these curing agents are used, there is a problem that the storage stability of the resin composition is impaired.

On the other hand, it is known that a thermosetting cyanate ester compound having a cyanato group can provide a cured product excellent in electrical characteristics. However, the reaction of forming an s-triazine ring by thermal curing of a cyanato group requires curing at a high temperature of, for example, 230 ℃ for 120 minutes or more for a relatively long time, and therefore, is not suitable as a resin composition for an interlayer insulating layer for a multilayer printed wiring board produced by the above-mentioned lamination method.

As a method for lowering the curing temperature of a cyanate ester compound, a method is known in which a cyanate ester compound and an epoxy resin are used in combination and cured using a curing catalyst (for example, see patent documents 1 and 2).

In addition, for the multilayer layer, there is a demand for a reduction in the coefficient of thermal expansion (reduction in CTE) and a measure suitable for the reduction in CTE, from the viewpoint of the need for dimensional stability in processing and a reduction in warpage after semiconductor mounting (for example, see patent documents 3 to 5). As the most mainstream method, the CTE of the multilayer layer is often reduced by making the silica filler highly filled (for example, making 40 mass% or more of the multilayer layer be the silica filler).

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2013-40298

Patent document 2: japanese laid-open patent publication No. 2010-90237

Patent document 3: japanese Kohyo publication No. 2006-527920

Patent document 4: japanese patent laid-open publication No. 2007-87982

Patent document 5: japanese laid-open patent publication No. 2009-280758

Disclosure of Invention

Problems to be solved by the invention

[a] If the silica filler is highly filled in order to reduce the CTE of the multilayer layer, it tends to be difficult to embed the irregularities of the wiring pattern of the inner layer circuit with the laminate material. Further, it is required to embed an inner layer circuit such as a via hole (Japanese: スルーホール) with a laminate material to reduce unevenness. If the silica filler is highly filled in order to reduce the CTE of the laminate, it tends to be difficult to satisfy these requirements.

The invention of claim 1 is made to solve the above problems, and an object thereof is to provide an adhesive film for a multilayer printed wiring board which has excellent uneven burying property even when a silica filler is highly filled.

[b] Further, it is difficult for a conventional resin composition for an interlayer insulating layer for a multilayer printed wiring board to have high heat resistance and insulation reliability and to have excellent workability in film formation.

The invention of claim 2 is made to solve the above problems, and an object thereof is to provide a resin film for an interlayer insulating layer formed using a thermosetting resin composition which has high heat resistance and insulation reliability and excellent workability in film formation, a multilayer resin film including the resin film for an interlayer insulating layer and a support, a multilayer printed wiring board, and a method for manufacturing the multilayer printed wiring board.

Means for solving the problems

[a] The present inventors have made intensive studies to solve the above-mentioned 1 st object, and as a result, have found that the above-mentioned 1 st object can be solved by using a resin composition comprising a specific phenol novolak resin, a specific epoxy resin, and a specific inorganic filler, and have completed the present invention. Namely, the invention 1 provides the following adhesive film.

(1) An adhesive film for a multilayer printed wiring board, comprising a resin composition layer formed by layering a resin composition on a support film, wherein the resin composition comprises: (A) a phenol novolac resin having a dispersion ratio Mw/Mn of weight average molecular weight Mw to number average molecular weight Mn of 1.05 to 1.8, (B) an epoxy resin represented by the following general formula (1), and (C) an inorganic filler, wherein the average particle diameter of the inorganic filler (C) in the resin composition layer is 0.1 [ mu ] m or more, and the content of the inorganic filler (C) is 20 to 95 mass% of the solid content of the resin.

[ solution 1]

(wherein p represents an integer of 1 to 5.)

[b] The present inventors have made extensive studies to solve the above problem 2, and as a result, have found that: the above-mentioned problem 2 can be solved by combining a specific curing agent and a specific antioxidant in a thermosetting resin composition containing an epoxy resin, a curing agent, an inorganic filler and an antioxidant, and the present invention has been completed. In addition, it was also found that: the above-mentioned problem 2 can be solved by combining a specific curing agent and a specific compound in a thermosetting resin composition containing an epoxy resin, a curing agent, an inorganic filler and a specific compound, and the present invention has been completed.

That is, the 2 nd invention provides the following [1] to [23 ].

[1] A resin film for an interlayer insulating layer, which is formed using a thermosetting resin composition containing (a) an epoxy resin, (b) a curing agent, (c) an inorganic filler and (d) an antioxidant,

the curing agent (b) contains at least 1 selected from the group consisting of an active ester curing agent (b1), a cyanate ester curing agent (b2), and a triazine ring-containing phenol novolac curing agent (b3), and the antioxidant (d) is a hindered phenol antioxidant.

[2] The resin film for an interlayer insulation layer according to the above [1], wherein the hindered phenol antioxidant contains at least 1 selected from the group consisting of a compound having a group represented by the following general formula (dI) and a compound represented by the following general formula (dII).

[ solution 2]

(in the formula (dI), R^d1、R^d2And R^d3Each independently represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. Wherein R is^d1And R^d2At least 1 of them represents an alkyl group having 1 to 8 carbon atoms. )

[ solution 3]

(in the formula (dII), R^d4And R^d5Each independently represents an alkyl group having 1 to 8 carbon atoms. R^d6、R^d7And R^d8Each independently represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. Wherein R is^d6、R^d7And R^d8At least 1 of them represents an alkyl group having 1 to 8 carbon atoms. )

[3] The resin film for an interlayer insulating layer according to the above [2], wherein the compound having a group represented by the above general formula (dI) is a compound represented by any one of the following general formulae (dI-1) to (dI-3).

[ solution 4]

(in formulae (dI-1) and (dI-2), R^d11、R^d12、R^d13、R^d21、R^d22And R^d23Each independently represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. Wherein R is^d11And R^d12At least 1 of (1), and R^d21And R^d22At least 1 of them represents an alkyl group having 1 to 8 carbon atoms. X¹And X²Each independently represents an organic group having a valence of 1 to 3. n is¹And n²Each independently is an integer of 1 to 3. )

[ solution 5]

(in the formula (dI-3), R^d31And R^d32Each independently represents an alkyl group having 1 to 8 carbon atoms. Y represents-COOCH₂－、－COOCH₂CH₂－。)

[4] The resin film for an interlayer insulation layer according to the above [3], wherein the hindered phenol antioxidant is at least 1 selected from the group consisting of a compound represented by the above general formula (dI-1) and a compound represented by the above general formula (dI-2), and has a molecular weight of 1,500 or less.

[5] A resin film for an interlayer insulating layer, which comprises (a) an epoxy resin, (b) a curing agent, (c) an inorganic filler, and (d') at least 1 selected from a compound having a group represented by the following general formula (dI) and a compound represented by the following general formula (dII),

the curing agent (b) contains at least 1 selected from the group consisting of an active ester-based curing agent (b1), a cyanate ester-based curing agent (b2), and a triazine ring-containing phenol novolac-based curing agent (b 3).

[ solution 6]

(in the formula (dI), R^d1、R^d2And R^d3Each independently represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. Wherein R is^d1And R^d2At least 1 of them represents an alkyl group having 1 to 8 carbon atoms. )

[ solution 7]

(in the formula (dII), R^d4And R^d5Each independently represents an alkyl group having 1 to 8 carbon atoms. R^d6、R^d7And R^d8Each independently represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. Wherein R is^d6、R^d7And R^d8At least 1 of (a) representsAn alkyl group having 1 to 8 carbon atoms. )

[6] The resin film for an interlayer insulating layer according to the above [5], wherein the compound having a group represented by the above general formula (dI) is a compound represented by any one of the following general formulae (dI-1) to (dI-3).

[ solution 8]

(in formulae (dI-1) and (dI-2), R^d11、R^d12、R^d13、R^d21、R^d22And R^d23Each independently represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. Wherein R is^d11And R^d12At least 1 of (1), and R^d21And R^d22At least 1 of them represents an alkyl group having 1 to 8 carbon atoms. X¹And X²Each independently represents an organic group having a valence of 1 to 3. n is¹And n²Each independently is an integer of 1 to 3. )

[ solution 9]

(in the formula (dI-3), R^d31And R^d32Each independently represents an alkyl group having 1 to 8 carbon atoms. Y represents-COOCH₂－、－COOCH₂CH₂－。)

[7] The resin film for an interlayer insulation layer according to the above [6], wherein the compound having a group represented by the above general formula (dI) is at least 1 selected from the group consisting of the compound represented by the above general formula (dI-1) and the compound represented by the above general formula (dI-2), and has a molecular weight of 1,500 or less.

[8] The resin film for an interlayer insulating layer according to any one of [1] to [7], wherein the ratio of the total number of functional groups of the curing agent (b) to the total number of epoxy groups of the epoxy resin (a), [ (b) the total number of functional groups of the curing agent/(a) the total number of epoxy groups of the epoxy resin ], is 0.2 to 2.

[9] The resin film for an interlayer insulation layer according to any one of the above [1] to [8], wherein the epoxy resin (a) has at least 1 selected from a bisphenol A type epoxy resin, a naphthalene type epoxy resin, an aralkyl novolac type epoxy resin having a biphenyl skeleton, and a cresol novolac type epoxy resin.

[10] The resin film for an interlayer insulating layer according to any one of the above [1] to [9], wherein the curing agent (b) comprises a cyanate ester-based curing agent (b 2).

[11] The resin film for an interlayer insulation layer according to any one of the above [1] to [9], wherein the curing agent (b) comprises at least 1 selected from an active ester-based curing agent (b1) and a phenol novolac-based curing agent (b3) containing a triazine ring.

[12] The resin film for an interlayer insulating layer according to any one of the above [1] to [9] and [11], wherein the (b3) triazine ring-containing phenol novolac-based curing agent comprises at least one of a triazine ring-containing phenol novolac resin and a triazine ring-containing cresol novolac resin.

[13] The resin film for an interlayer insulation layer according to any one of the above [1] to [12], wherein the content of the inorganic filler (c) is 30 to 90% by mass based on the solid content of the thermosetting resin composition.

[14] The resin film for an interlayer insulation layer according to any one of the above [1] to [13], wherein the inorganic filler (c) contains at least 1 selected from spherical silica and fused silica, and has a volume average particle diameter of 0.01 to 5 μm.

[15] The resin film for an interlayer insulation layer according to any one of the above [1] to [14], wherein the thermosetting resin composition further contains (e) a phenoxy resin.

[16] The resin film for an interlayer insulating layer according to the above [15], wherein the phenoxy resin (e) has an alicyclic structure.

[17] The resin film for an interlayer insulating layer according to any one of the above [1] to [16], which is for a multilayer printed wiring board.

[18] The resin film for an interlayer insulating layer according to any one of the above [1] to [16], which is for forming a laminate layer of a multilayer printed wiring board.

[19] A multilayer resin film comprising the resin film for an interlayer insulation layer according to any one of [1] to [16] above and a support.

[20] The multilayer resin film according to the above [19], wherein the support is an organic resin film having a thickness of 10 to 70 μm, and the resin film for an interlayer insulating layer has a thickness of 1 to 80 μm.

[21] A multilayer printed wiring board obtained by using at least 1 selected from the resin film for an interlayer insulation layer according to any one of [1] to [16] above and the multilayer resin film according to [19] or [20] above.

[22] A semiconductor package comprising the multilayer printed wiring board according to [21] and a semiconductor element mounted thereon.

[23] A method for producing a multilayer printed wiring board using the resin film for an interlayer insulating layer according to any one of [1] to [16] above and the multilayer resin film according to [19] or [20], comprising the steps of:

(1) and laminating the resin film for an interlayer insulating layer and the multilayer resin film on one or both surfaces of a circuit board.

(2) And (3) forming an insulating layer by thermally curing the resin film laminated in the step (1).

(3) And (3) perforating the circuit substrate with the insulating layer formed in the step (2).

(4) And removing the drilling dirt.

(5) And (4) forming a conductor layer on the surface of the insulating layer obtained in step (4) by plating.

(6) And forming a circuit on the conductor layer by a semi-additive method.

Effects of the invention

[a] According to the invention of claim 1, an adhesive film for a multilayer printed wiring board having excellent embeddability of irregularities can be provided even when the silica filler is highly filled.

[b] According to the invention of claim 2, there can be provided a resin film for an interlayer insulating layer formed using a thermosetting resin composition which is high in heat resistance and insulation reliability and excellent in workability in film formation, a multilayer resin film having the resin film for an interlayer insulating layer and a support, a multilayer printed wiring board, and a method for producing the multilayer printed wiring board.

Detailed Description

[a] Invention 1

The adhesive film for a multilayer printed wiring board of the present invention has a resin composition layer formed by forming a layer of a resin composition (hereinafter, also referred to as "resin composition for an adhesive film") on a support film, the resin composition comprising (A) a phenol novolac resin (hereinafter, also referred to simply as "(A) a phenol novolac resin") (B) an epoxy resin represented by the above general formula (1) (hereinafter, also referred to simply as "(B) an epoxy resin"), and (C) an inorganic filler, the average particle diameter of the inorganic filler (C) in the resin composition layer being 0.1 [ mu ] m or more, and the content of the inorganic filler (C) being 20 to 95 mass% of the solid content of the resin.

[ resin composition for adhesive film ]

The resin composition for adhesive films comprises (A) a phenol novolac resin, (B) an epoxy resin, and (C) an inorganic filler. These components will be described below.

(A) phenol novolac resin

(A) The novolac phenol resin is used as a curing agent for an epoxy resin, and the dispersion ratio (Mw/Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is in the range of 1.05 to 1.8.

Such a novolak phenol resin (a) can be produced by, for example, a production method described in japanese patent No. 4283773.

That is, a phenol compound and an aldehyde compound as raw materials, a phosphoric acid compound as an acid catalyst, and a non-reactive oxygen-containing organic solvent as a reaction auxiliary solvent are used, and the two layers formed by these are separated and mixed by stirring, for example, by mechanical stirring, ultrasonic waves, or the like to form a turbid-white heterogeneous reaction system (phase separation reaction) in which the two layers (organic phase and aqueous phase) are mixed, and the reaction between the phenol compound and the aldehyde compound is promoted, whereby a condensate (resin) can be synthesized.

Then, for example, a water-insoluble organic solvent (e.g., methyl ethyl ketone, methyl isobutyl ketone, etc.) is added and mixed to dissolve the condensate, the mixture is left to stand while stirring and mixing are stopped, the mixture is separated into an organic phase (organic solvent phase) and an aqueous phase (phosphoric acid aqueous solution phase), the aqueous phase is removed and recovered, and after hot water washing and/or neutralization of the organic phase, the organic solvent is distilled and recovered, whereby the (a) phenol novolac resin can be produced.

In the above-mentioned method for producing a phenol novolak resin, since a phase separation reaction is utilized, stirring efficiency is extremely important, and from the viewpoint of reaction efficiency, it is desirable to promote conversion of a phenol compound into a resin by making the two phases in the reaction system fine and increasing the surface area of the interface as much as possible.

As the phenol compound which can be used as the raw material, for example, there can be mentioned: phenol; o-cresol; m-cresol; p-cresol; xylenol; a bisphenol compound; an ortho-substituted phenol compound having an ortho-position hydrocarbon group having 3 or more carbon atoms, preferably 3 to 10 carbon atoms; and a para-substituted phenol compound having a hydrocarbon group having 3 or more carbon atoms, preferably 3 to 18 carbon atoms, in the para position. These may be used alone in 1 kind, or may be used in combination of 2 or more kinds.

Here, examples of the bisphenol compound include: bisphenol A, bisphenol F, bis (2-methylphenol) A, bis (2-methylphenol) F, bisphenol S, bisphenol E, bisphenol Z and the like.

Examples of the ortho-substituted phenol compound include: 2-propylphenol, 2-isopropylphenol, 2-sec-butylphenol, 2-tert-butylphenol, 2-phenylphenol, 2-cyclohexylphenol, 2-nonylphenol, 2-naphthylphenol and the like.

Examples of the para-substituted phenol compound include: 4-propylphenol, 4-isopropylphenol, 4-sec-butylphenol, 4-tert-butylphenol, 4-phenylphenol, 4-cyclohexylphenol, 4-nonylphenol, 4-naphthylphenol, 4-dodecylphenol, 4-octadecylphenol and the like.

Examples of the aldehyde compound which can be used as a raw material include: formaldehyde, formalin, paraformaldehyde, trioxymethylene, acetaldehyde, paraldehyde, propionaldehyde and the like. Among these, paraformaldehyde is preferable from the viewpoint of the reaction rate. These may be used alone in 1 kind, or may be used in combination of 2 or more kinds.

The molar ratio (F/P) of the aldehyde compound (F) to the phenol compound (P) is preferably 0.33 or more, more preferably 0.40 to 1.0, and still more preferably 0.50 to 0.90. When the blending molar ratio (F/P) is within the above range, an excellent yield can be obtained.

The phosphoric acid compound serving as an acid catalyst plays an important role in the site (Japanese: fruit) where a phase separation reaction is formed with the phenol compound in the presence of water. As the phosphoric acid compound, for example, an aqueous solution type such as 89 mass% phosphoric acid or 75 mass% phosphoric acid can be used. Further, for example, polyphosphoric acid, phosphoric anhydride, or the like may be used as necessary.

From the viewpoint of controlling the effect of phase separation, the content of the phosphoric acid compound is, for example, 5 parts by mass or more, preferably 25 parts by mass or more, and more preferably 50 to 100 parts by mass, relative to 100 parts by mass of the phenol compound. When 70 parts by mass or more of the phosphoric acid compound is used, it is preferable to suppress heat generation at the initial stage of the reaction by batch charging into the reaction system, thereby ensuring safety.

The non-reactive oxygen-containing organic solvent as the reaction auxiliary solvent plays an extremely important role in promoting the phase separation reaction. As the reaction auxiliary solvent, at least one compound selected from the group consisting of an alcohol compound, a polyol ether, a cyclic ether compound, a polyol ester, a ketone compound, and a sulfoxide compound is preferably used.

Examples of the alcohol compound include: monohydric alcohols such as methanol, ethanol, and propanol; diols such as butanediol, pentanediol, hexanediol, ethylene glycol, propylene glycol, trimethylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol, and polyethylene glycol; trihydric alcohols such as glycerin, etc.

Examples of the polyol ether include: ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monopentyl ether, ethylene glycol dimethyl ether, ethylene glycol methyl ethyl ether, ethylene glycol diethyl ether, etc.

Examples of the cyclic ether compound include 1, 3-dioxane, 1, 4-dioxane, and the like, and examples of the polyol ester include glycol ester compounds such as ethylene glycol acetate, and the like. Examples of the ketone compound include acetone, methyl ethyl ketone (hereinafter also referred to as "MEK") and methyl isobutyl ketone, and examples of the sulfoxide compound include dimethyl sulfoxide and diethyl sulfoxide.

Of these, ethylene glycol monomethyl ether, polyethylene glycol, and 1, 4-dioxane are preferred.

The reaction auxiliary solvent is not limited to the above-mentioned examples, and may be a solid as long as it has the above-mentioned characteristics and is in a liquid state during the reaction, and may be used alone or in combination of 2 or more.

The amount of the reaction auxiliary solvent is not particularly limited, and is, for example, 5 parts by mass or more, preferably 10 to 200 parts by mass, per 100 parts by mass of the phenol compound.

By using a surfactant in the heterogeneous reaction step, the phase separation reaction can be promoted, the reaction time can be shortened, and the yield can be improved.

Examples of the surfactant include: anionic surfactants such as soap, α -olefin sulfonate, alkylbenzene sulfonic acid and salts thereof, alkyl sulfate ester salts, alkyl ether sulfate ester salts, phenyl ether ester salts, polyoxyethylene alkyl ether sulfate ester salts, ether sulfonate, and ether carboxylate; nonionic surfactants such as polyoxyethylene alkylphenyl ethers, polyoxyalkylene alkyl ethers, polyoxyethylene styrenated phenol ethers, polyoxyethylene alkylamino ethers, polyethylene glycol aliphatic esters, aliphatic monoglycerides, sorbitan aliphatic esters, pentaerythritol aliphatic esters, polyoxyethylene polypropylene glycols, and aliphatic alkanolamides; and cationic surfactants such as monoalkylammonium chloride, dialkylammonium chloride, and amine acid salt (Japanese アミン acid salt) compounds.

The amount of the surfactant to be blended is not particularly limited, and is, for example, 0.5 parts by mass or more, preferably 1 to 10 parts by mass, per 100 parts by mass of the phenol compound.

The amount of water in the reaction system affects the phase separation effect and the production efficiency, and is generally 40 mass% or less on a mass basis. By setting the amount of water to 40 mass% or less, the production efficiency can be maintained well.

The reaction temperature of the phenol compound and the aldehyde compound is not particularly limited, and varies depending on the kind of the phenol compound, the reaction conditions, and the like, and is usually 40 ℃ or higher, preferably 80 ℃ to reflux temperature, and more preferably reflux temperature. When the reaction temperature is 40 ℃ or higher, a sufficient reaction rate can be obtained. The reaction time varies depending on the reaction temperature, the amount of phosphoric acid added, the water content in the reaction system, and the like, and is usually about 1 to 10 hours.

The reaction environment is usually normal pressure, and the reaction may be carried out under increased pressure or reduced pressure from the viewpoint of maintaining the characteristics of the present invention, i.e., the heterogeneous reaction. For example, the reaction rate can be increased under a pressure of 0.03 to 1.50MPa, and a low boiling point solvent such as methanol can be used as a reaction auxiliary solvent.

The method for producing a phenol novolac resin (A) can produce a phenol novolac resin having a dispersion ratio (Mw/Mn) of weight average molecular weight (Mw) to number average molecular weight (Mn) of 1.05 to 1.8

The phenol compound (P) may be used alone or in combination with an aldehyde compound (F) in a mixture of the phenol compound (P) and the aldehyde compound (F).

In the range of the compounding molar ratio (F/P) of 0.33 or more and less than 0.80, the following phenol novolac resin can be produced in high yield: in the measurement method by the area method of Gel Permeation Chromatography (GPC), the content of the monomer component of the phenol compound is, for example, 3 mass% or less, preferably 1 mass% or less, the content of the dimer component of the phenol compound is, for example, 5 to 95 mass%, preferably 10 to 95 mass%, and the dispersion ratio (Mw/Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) measured by GPC is, for example, 1.05 to 1.8, preferably 1.1 to 1.7.

As the novolak type phenol resin (A), commercially available ones can be used, and examples thereof include "PAPS-PN 2" (product name, manufactured by Asahi organic materials Co., Ltd.), "PAPS-PN 3" (product name, manufactured by Asahi organic materials Co., Ltd.), and the like.

The resin composition for adhesive films may be used in combination with (a) an epoxy resin curing agent other than a phenol novolac resin (hereinafter also simply referred to as "epoxy resin curing agent") within a range not to impair the effects of the present invention.

Examples of the epoxy resin curing agent include: various phenolic resin compounds other than the (a) novolak type phenolic resin, acid anhydride compounds, amine compounds, hydrazide compounds, and the like. Examples of the phenolic resin compound include novolak type phenolic resins other than the novolak type phenolic resin (a), resol type phenolic resins, and the like; examples of the acid anhydride compound include phthalic anhydride, benzophenone tetracarboxylic dianhydride, and methylnadic anhydride. Examples of the amine compound include dicyandiamide, diaminodiphenylmethane, and guanylurea.

Among these epoxy resin curing agents, a phenol novolac resin other than (a) phenol novolac resin is preferable from the viewpoint of improving reliability.

Further, from the viewpoint of improving the peel strength of the metal foil and the peel strength of electroless plating after chemical roughening, a triazine ring-containing phenol novolac resin and dicyandiamide are preferable.

As the phenol novolak resin other than the phenol novolak resin (A), commercially available ones can be used, and examples thereof include phenol novolak resins such as "TD 2090" (trade name, manufactured by DIC Co., Ltd.), and cresol novolak resins such as "KA-1165" (trade name, manufactured by DIC Co., Ltd.). Further, examples of commercially available products of triazine ring-containing novolak resins include "Phenolite LA-1356" (trade name, manufactured by DIC corporation) and "Phenolite LA7050 series" (trade name, manufactured by DIC corporation), and examples of commercially available products of triazine ring-containing cresol novolak resins include "Phenolite LA-3018" (trade name, manufactured by DIC corporation).

(B) epoxy resin

(B) The epoxy resin is represented by the following general formula (1).

[ solution 10]

(wherein p represents an integer of 1 to 5.)

As the epoxy resin (B), commercially available products can be used. Examples of commercially available (B) epoxy resins include: "NC-3000" (an epoxy resin having p of 1.7 in the formula (1)), and "NC-3000-H" (an epoxy resin having p of 2.8 in the formula (1)) (both trade names, manufactured by Nippon Kagaku K.K.).

The resin composition for an adhesive film may contain a polymer type epoxy resin such as an epoxy resin other than the epoxy resin (B) and a phenoxy resin, within a range not to impair the effects of the present invention.

< curing Accelerator >

The resin composition for an adhesive film may contain a curing accelerator from the viewpoint of accelerating the reaction between the (a) novolac type phenol resin and the (B) epoxy resin. Examples of the curing accelerator include: imidazole compounds such as 2-phenylimidazole, 2-ethyl-4-methylimidazole, and 1-cyanoethyl-2-phenyltrimellitic acid imidazole; organophosphorus compounds such as triphenylphosphine; onium salts such as phosphonium borate; amines such as 1, 8-diazabicycloundecene; 3- (3, 4-dichlorophenyl) -1, 1-dimethylurea, and the like. These may be used alone in 1 kind, or may be used in combination of 2 or more kinds.

(C) inorganic filler

The resin composition for adhesive films contains (C) an inorganic filler having an average particle diameter of 0.1 [ mu ] m or more.

Examples of the inorganic filler (C) include: silica, alumina, barium sulfate, talc, clay, mica powder, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium oxide, boron nitride, aluminum borate, barium titanate, strontium titanate, calcium titanate, bismuth titanate, titanium oxide, barium zirconate, calcium zirconate, and the like. These may be used alone in 1 kind, or may be used in combination of 2 or more kinds. Among these, silicon dioxide is preferable from the viewpoint of reducing the thermal expansion coefficient of the interlayer insulating layer formed by curing the adhesive film.

(C) The shape of the inorganic filler is not particularly limited, and is preferably spherical from the viewpoint of easily embedding the through holes formed in the inner layer circuit and the irregularities of the circuit pattern.

(C) The average particle size of the inorganic filler is 0.1 μm or more, and from the viewpoint of obtaining excellent embeddability, it is preferably 0.2 μm or more, and more preferably 0.3 μm or more.

From the viewpoint of embeddability, the content of the inorganic filler having an average particle diameter of less than 0.1 μm is preferably 3 vol% or less, more preferably 1 vol% or less, and further preferably no inorganic filler having an average particle diameter of less than 0.1 μm, in terms of solid content. The inorganic filler (C) may be used alone in 1 kind, or may be used in combination in 2 or more kinds, or inorganic fillers having different average particle diameters may be used in combination.

As the (C) inorganic filler, commercially available products can be used. Examples of commercially available (C) inorganic fillers include: examples of the spherical silica include "SO-C1" (average particle size: 0.25 μm), "SO-C2" (average particle size: 0.5 μm), "SO-C3" (average particle size: 0.9 μm), "SO-C5" (average particle size: 1.6 μm) and "SO-C6" (average particle size: 2.2 μm) (all manufactured by Admatechs Co., Ltd.).

(C) The inorganic filler material may be surface-treated. For example, when silica is used as the (C) inorganic filler, a silane coupling agent treatment may be performed as the surface treatment. Examples of the silane coupling agent include: aminosilane coupling agents, vinylsilane coupling agents, epoxysilane coupling agents, and the like. Among these, silica subjected to surface treatment with an aminosilane coupling agent is preferable.

The amount of the inorganic filler (C) in the resin composition for adhesive film is defined as follows. First, the resin composition forming a layer on the support film was dried at 200 ℃ for 30 minutes, the solvent contained in the resin composition was removed, and the weight (solid content) after the solvent removal was measured. The amount of (C) inorganic filler contained in the solid content is defined as the amount of (C) inorganic filler in the resin solid content.

In addition, as a method for measuring the (C) inorganic filler, if the amount of the solid content of the (C) inorganic filler to be blended is calculated in advance, the ratio in the solid content can be easily determined. The following shows a calculation example when (C) an inorganic filler dispersed in a solvent (hereinafter also referred to as "(C) an inorganic filler dispersion liquid") is used.

The solid content of the (C) inorganic filler in the (C) inorganic filler dispersion was calculated to be 70% by mass after drying at 200 ℃ for 30 minutes. The total amount of the resin composition obtained by using 40g of the inorganic filler dispersion (C) was 100 g. 100g of the resin composition was dried at 200 ℃ for 30 minutes, and the weight of the dried solid content was measured, whereby 60g was obtained. Since the amount of the (C) inorganic filler contained in the solid content was 40g × 70 mass% to 28g, the amount of the (C) inorganic filler in the solid content of the resin was determined to be 28/60 mass% to 47 mass% (46.6 mass%).

The amount of the inorganic filler (C) in the resin composition for an adhesive film is preferably increased from the viewpoint of reducing the thermal expansion coefficient of the interlayer insulating layer after thermal curing, but an appropriate amount of the inorganic filler is present from the viewpoint of filling the irregularities and the through holes of the wiring pattern of the inner layer circuit substrate to be formed. From such a viewpoint, the content of the (C) inorganic filler is 20 to 95% by mass, preferably 30 to 90% by mass, and more preferably 50 to 90% by mass in the solid resin component. When the content of the (C) inorganic filler is 20% by mass or more, the thermal expansion coefficient can be reduced; when the content is 95% by mass or less, the embeddability can be favorably maintained.

< flame retardant >

The resin composition for adhesive film may further contain a flame retardant.

The flame retardant is not particularly limited, and examples thereof include inorganic flame retardants and resin flame retardants.

Examples of the inorganic flame retardant include: examples of the inorganic filler (C) include aluminum hydroxide and magnesium hydroxide.

The resin flame retardant may be a halogen-based resin or a non-halogen-based resin, but in view of environmental load, it is preferable to use a non-halogen-based resin. The resin flame retardant may be compounded in the form of a filler or may be a resin having a functional group that reacts with the thermosetting resin.

Commercially available resin flame retardants can be used. Examples of commercially available resin flame retardants that are blended as fillers include: "PX-200" (trade name, manufactured by Dai eight chemical industries, Ltd.) as an aromatic phosphate flame retardant, "ExolitOP 930" (trade name, manufactured by Clariant Japan K.K.) as a polyphosphate compound, and the like.

Examples of commercially available resin flame retardants having a functional group that reacts with a thermosetting resin include epoxy-based phosphorus-containing flame retardants and phenol-based phosphorus-containing flame retardants. Examples of the epoxy-based phosphorus-containing flame retardant include: "FX-305" (trade name, manufactured by Nippon iron Co., Ltd.); examples of the phenol-based phosphorus-containing flame retardant include "HCA-HQ" (trade name, manufactured by Sanko Co., Ltd.) and "XZ 92741" (trade name, manufactured by DOWCHEMICAL). These may be used alone in 1 kind, or may be used in combination of 2 or more kinds.

< solvent >

The resin composition for an adhesive film preferably contains a solvent from the viewpoint of efficiently forming a layer. Examples of the solvent include: ketone compounds such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; acetate compounds such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate, and carbitol acetate; carbitol compounds such as cellosolve, methyl carbitol, butyl carbitol and the like; aromatic hydrocarbon compounds such as toluene and xylene; dimethylformamide, dimethylacetamide, N-methylpyrrolidone, diethylene glycol dimethyl ether, propylene glycol monomethyl ether, and the like. These may be used alone in 1 kind, or may be used in combination of 2 or more kinds.

< amount of residual solvent >

The amount of the residual solvent in the adhesive film of the present invention is preferably 1 to 20% by mass, more preferably 2 to 15% by mass, and still more preferably 2 to 10% by mass, depending on the material used. When the amount of the residual solvent is 1% by mass or more, the workability of the adhesive film is improved, and for example, the occurrence of powder falling, cracking, and the like at the time of cutting with a cutter can be suppressed. On the other hand, when the content is 20% by mass or less, stickiness is suppressed, and winding and unwinding of the film are facilitated. In addition, in order to enable unwinding, a protective film is often provided on the varnish-coated surface of the adhesive film after drying, and if the amount of the residual solvent is 20 mass% or less, peeling between the protective film and the adhesive film of the present invention becomes easy.

In addition, the residual solvent is removed by drying and thermosetting in the process of producing the multilayer printed wiring board, and therefore, is preferably small from the viewpoint of environmental compatibility, and is also preferably small in order to reduce the change in film thickness before and after drying and thermosetting.

In the production of the adhesive film of the present invention, the drying conditions are preferably determined so as to achieve a target amount of residual solvent. The drying conditions vary depending on the kind of solvent contained in the resin composition, the amount of solvent, and the like, and therefore, it is preferable to determine the conditions after previously searching for the conditions by each coating apparatus.

Here, the residual solvent amount in the present invention means: the proportion (% by mass) of the solvent contained in the resin composition layer of the support film can be defined as follows.

First, the weight (W) of the support film was measured_a) And the weight (W) after forming the resin composition layer thereon was measured_b). Then, the support film and the resin composition layer formed thereon were dried at 200 ℃Left in the machine for 10 minutes, and the weight (W) after drying was measured_c). The resulting weight (W) can be used_a)～(W_c) The calculation is performed by the following formula.

The ratio of the solvent (mass%) ((1- ((W))_c)－(W_a))/((W_b)－(W_a)))×100

< other ingredients >

The adhesive film of the present invention may contain other components within a range not to inhibit the effects of the present invention. Examples of other components include: thickeners such as ORBEN, bentonite (Japanese: ベントン), etc.; ultraviolet absorbers such as thiazole-based and triazole-based ones; adhesion imparting agents such as silane coupling agents; colorants such as phthalocyanine blue, phthalocyanine green, iodine green, disazo yellow, and carbon black; any resin component other than the above.

[ support film ]

The support film in the present invention means: the film serving as a support in the production of the adhesive film of the present invention is usually finally peeled or removed in the production of a multilayer printed wiring board.

The support film is not particularly limited, and examples thereof include: organic resin films, metal foils, release papers, and the like.

Examples of the material of the organic resin film include: polyolefins such as polyethylene and polyvinyl chloride; polyesters such as polyethylene terephthalate (hereinafter also referred to as "PET") and polyethylene naphthalate; polycarbonate, polyimide, and the like. Among these, PET is preferable from the viewpoint of price and operability.

Examples of the metal foil include copper foil and aluminum foil. When a copper foil is used as the support, a circuit may be formed by using the copper foil as a conductor layer as it is. In this case, as the copper foil, rolled copper, electrolytic copper foil, or the like can be used. The thickness of the copper foil is not particularly limited, and for example, a copper foil having a thickness of 2 to 36 μm can be used. When a copper foil having a small thickness is used, a copper foil with a carrier can be used from the viewpoint of improving workability.

These support films and protective films described later may be subjected to surface treatment such as mold release treatment, plasma treatment, corona treatment, and the like. Examples of the mold release treatment include: and mold release treatments based on silicone resin-based mold release agents, alkyd resin-based mold release agents, fluororesin-based mold release agents, and the like.

The thickness of the support film is not particularly limited, but is preferably 10 to 120 μm, more preferably 15 to 80 μm, and still more preferably 15 to 70 μm from the viewpoint of handling.

The support film does not need to be a single component as described above, and may be formed of a plurality of layers (2 or more layers) of different materials.

Examples of the support film having a 2-layer structure include: the above-listed support films were used as the support film of the 1 st layer, and a layer formed of an epoxy resin, a curing agent for an epoxy resin, a filler, or the like was used as the 2 nd layer. As the material for the layer 2, those listed as the materials used for the adhesive film of the present invention can be used.

The layer formed on the support film of the 1 st layer (the 2 nd layer and thereafter, may be a multilayer of 2 or more) is a layer formed for imparting a function, and may be used for the purpose of improving adhesiveness with copper plating, for example.

The method for forming the 2 nd layer is not particularly limited, and examples thereof include the following: a method of coating a varnish in which each material is dissolved and dispersed in a solvent on the support film of the 1 st layer and drying the coating.

When the support film is formed of a plurality of layers, the thickness of the support film of the 1 st layer is preferably 10 to 100 μm, more preferably 10 to 60 μm, and further preferably 13 to 50 μm.

The thickness of the layer (2 nd layer and thereafter, may be a multilayer of 2 or more) formed on the support film of the 1 st layer is preferably 1 to 20 μm. When the thickness is 1 μm or more, the intended function can be exhibited, and when the thickness is 20 μm or less, the economical efficiency as a support film is excellent.

When the support film is formed in a plurality of layers, the support film may be separated into a layer (2 or more layers) remaining on the multilayer printed wiring board side together with the adhesive film of the present invention and a layer to be peeled or removed (2 or more layers).

[ protective film ]

The adhesive film of the present invention may have a protective film. The protective film is provided on the surface of the adhesive film opposite to the surface provided with the support, and is used for the purpose of preventing the adhesive film from being scratched by foreign matter or the like. The protective film is peeled off before the adhesive film of the present invention is laminated on a circuit board or the like by lamination, hot pressing, or the like.

The protective film is not particularly limited, and the same material as the support film can be used. The thickness of the protective film is not particularly limited, and for example, a protective film having a thickness of 1 to 40 μm can be used.

[ method for producing adhesive film ]

The adhesive film of the present invention can be produced by applying the resin composition for adhesive film to a support film and drying the applied composition. The obtained adhesive film can be wound into a roll for storage and storage. More specifically, for example, it can be manufactured as follows: the resin composition for adhesive film is prepared by dissolving the resin components in the organic solvent, mixing (C) an inorganic filler and the like, applying the varnish on a support film, and drying the organic solvent by heating, hot air blowing or the like to form a resin composition layer on the support film.

In the adhesive film of the present invention, the resin composition layer formed on the support film may be in an uncured state obtained by drying the resin composition layer or may be in a semi-cured (b-staged) state.

The method for applying the varnish on the support film is not particularly limited, and for example, a method of applying the varnish using a known application apparatus such as a comma coater, a bar coater, a kiss coater, a roll coater, a gravure coater, or a die coater can be used. The coating apparatus may be selected as appropriate according to the target film thickness.

[b] Invention 2

Next, the resin film for an interlayer insulating layer, the multilayer resin film, the multilayer printed wiring board, and the methods for producing the same according to claim 2 will be described.

[ resin film for interlayer insulating layer ]

The thermosetting resin composition used for forming the resin film for an interlayer insulating layer of the present invention [ hereinafter, referred to as a resin composition for an interlayer insulating layer ]. Contains as previously described: (a) an epoxy resin (hereinafter, also referred to as "component (a)"), (b) a specific curing agent (hereinafter, also referred to as "component (b)"), (c) an inorganic filler (hereinafter, also referred to as "component (c)"), and (d) a specific antioxidant (hereinafter, also referred to as "component (d)") or (d') a specific compound (hereinafter, also referred to as "component (d)").

The resin film for an interlayer insulating layer is also generally referred to as an interlayer insulating film.

< resin composition for interlayer insulating layer >

[ (a) epoxy resin ]

(a) The epoxy resin is not particularly limited, and for example, an epoxy resin having two or more epoxy groups in 1 molecule is preferable.

Examples of the epoxy resin (a) include: glycidyl ether type epoxy resins, glycidyl amine type epoxy resins, glycidyl ester type epoxy resins, and the like. Among these, glycidyl ether type epoxy resins are preferred.

(a) The epoxy resins may be classified according to the difference of the main skeleton, and among the above types of epoxy resins, they may be classified as: bisphenol epoxy resins such as bisphenol a epoxy resin (preferably bisphenol a liquid epoxy resin), bisphenol F epoxy resin, and bisphenol S epoxy resin; phenol novolac type epoxy resins such as phenol novolac type epoxy resin, alkylphenol novolac type epoxy resin, cresol novolac type epoxy resin, naphthol alkylphenol copolymer novolac type epoxy resin, bisphenol a novolac type epoxy resin, bisphenol F novolac type epoxy resin, aralkyl novolac type epoxy resin; stilbene type epoxy resins; an epoxy resin having a triazine skeleton; an epoxy resin containing a fluorene skeleton; naphthalene type epoxy resins; triphenylmethane type epoxy resins; biphenyl type epoxy resin; xylylene type epoxy resins; and alicyclic epoxy resins such as dicyclopentadiene type epoxy resins. (a) The epoxy resin may be used alone in 1 kind, or may be used in combination in 2 or more kinds.

Examples of the aralkyl novolac type epoxy resin include aralkyl cresol copolymer novolac type epoxy resins having a naphthol skeleton, aralkyl novolac type epoxy resins having a biphenyl skeleton, and the like, and aralkyl novolac type epoxy resins having a biphenyl skeleton are preferable.

Among these, from the viewpoint of heat resistance, insulation reliability, and handling properties at the time of film formation, at least 1 selected from the group consisting of bisphenol-type epoxy resins and novolac-type epoxy resins is preferable, and at least 1 selected from the group consisting of bisphenol a-type epoxy resins, cresol-novolac-type epoxy resins, aralkyl-novolac-type epoxy resins, and bisphenol a-novolac-type epoxy resins is more preferable. Further, as the aralkyl novolac type epoxy resin, an aralkyl novolac type epoxy resin having a biphenyl skeleton is more preferable.

When 2 or more kinds of (a) epoxy resins are used in combination, a combination of a bisphenol a-type epoxy resin and an aralkyl novolac-type epoxy resin (particularly, an aralkyl novolac-type epoxy resin having a biphenyl skeleton), or a combination of a cresol novolac-type epoxy resin and a bisphenol a novolac-type epoxy resin is preferable.

When the bisphenol a-type epoxy resin and the aralkyl novolac-type epoxy resin (particularly, aralkyl novolac-type epoxy resin having a biphenyl skeleton) are contained in combination, the content ratio thereof (bisphenol a-type epoxy resin/aralkyl novolac-type epoxy resin) is preferably 15/85 to 50/50, more preferably 15/85 to 45/55, and still more preferably 20/80 to 40/60, from the viewpoints of heat resistance, insulation reliability, and handling during film formation.

When the cresol novolac epoxy resin and the bisphenol a novolac epoxy resin are used in combination, the content ratio thereof (cresol novolac epoxy resin/bisphenol a novolac epoxy resin) is preferably 50/50 to 85/15, more preferably 45/55 to 85/15, and still more preferably 55/45 to 75/25, from the viewpoints of heat resistance, insulation reliability, and handling properties in film formation.

Here, the aralkyl novolac epoxy resin having a biphenyl skeleton is an aralkyl novolac epoxy resin containing an aromatic ring of a biphenyl derivative in a molecule, and examples thereof include an epoxy resin containing a structural unit represented by the following general formula (a 1).

[ solution 11]

In the general formula (a1), R^a1Represents a hydrogen atom or a methyl group.

The content of the structural unit represented by the general formula (a1) in the epoxy resin containing the structural unit represented by the general formula (a1) is preferably 50 to 100% by mass, more preferably 70 to 100% by mass, and still more preferably 80 to 100% by mass, from the viewpoints of heat resistance, insulation reliability, and handling properties in film formation.

Examples of the epoxy resin containing a structural unit represented by the general formula (a1) include epoxy resins represented by the following general formula (a 1-1).

[ solution 12]

In the general formula (a 1-1), R^a1In the same manner as above, m¹Represents an integer of 1 to 20. Two or more R^a1May be the same or different from each other, but are preferably the same.

The bisphenol a novolac-type epoxy resin may be represented by the following general formula (a 2).

[ solution 13]

In the general formula (a2), m²Represents 1 to 10 integersAnd (4) counting.

The epoxy resin (a) may contain an epoxy resin that is liquid at room temperature (hereinafter, may be simply referred to as a liquid epoxy resin) from the viewpoint of improving the workability of the resin film for an interlayer insulating layer. The liquid epoxy resin is not particularly limited, and examples thereof include 2-functional liquid epoxy resins such as bisphenol a type liquid epoxy resin. When the epoxy resin (a) contains a liquid epoxy resin, the content thereof is preferably 10 to 60% by mass, more preferably 10 to 50% by mass, and still more preferably 10 to 40% by mass, relative to the epoxy resin (a), from the viewpoint of improving the workability of the resin film for an interlayer insulating layer.

As the epoxy resin (a), commercially available products can be used. Examples of commercially available (a) epoxy resins include: "NC-3000-H", "NC-3000-L", "NC-3100", "NC-3000" (or more, trade name, aralkyl novolak type epoxy resin having a biphenyl skeleton, manufactured by Nippon Kabushiki Kaisha), "NC-7000-L" (trade name, naphthol novolak type epoxy resin, manufactured by Nippon Kabushiki Kaisha), "JER 828" (trade name, bisphenol A type epoxy resin, manufactured by Mitsubishi chemical corporation), "JER 157S 70" (trade name, bisphenol A novolak type epoxy resin, manufactured by Mitsubishi chemical corporation), and the like.

(a) The epoxy equivalent of the epoxy resin is preferably 150 to 500g/eq, more preferably 150 to 400g/eq, still more preferably 170 to 350g/eq, particularly preferably 200 to 320g/eq, and may be 170 to 230g/eq, or 250 to 320g/eq, from the viewpoint of heat resistance, insulation reliability, and workability in film formation.

The epoxy equivalent is the mass (g/eq) of the resin per unit epoxy group, and can be measured by the method prescribed in JISK7236 (2001). Specifically, it is obtained by: 2g of an epoxy resin was weighed in a200 ml beaker using an automatic titration apparatus "GT-200 type" manufactured by Mitsubishi Chemical Analyzech, Ltd., methyl ethyl ketone (90 ml) was added dropwise, and after dissolving the epoxy resin in an ultrasonic cleaner, 10ml of glacial acetic acid and 1.5g of cetyltrimethylammonium bromide were added, followed by titration with a 0.1mol/L perchloric acid/acetic acid solution.

The content of the epoxy resin (a) in the resin composition for an interlayer insulating layer is preferably 20 to 80 parts by mass, more preferably 30 to 70 parts by mass, and even more preferably 35 to 60 parts by mass, based on 100 parts by mass of the solid content of the resin composition for an interlayer insulating layer (herein, the inorganic filler (c)) from the viewpoints of heat resistance, insulation reliability, and handling properties during film formation.

The term "solid component" as used herein means, unless otherwise specified, a nonvolatile component obtained by removing a volatile component such as an organic solvent, and means a component which remains without volatilization when the thermosetting resin composition is dried, and includes components which are liquid, syrup-like, and wax-like at room temperature. Herein, room temperature in the present specification means 25 ℃.

[ (b) curing agent ]

In the present invention, the (b) curing agent contains at least 1 selected from (b1) an active ester-based curing agent, (b2) a cyanate ester-based curing agent, and (b3) a triazine ring-containing phenol novolac-based curing agent. When 2 or more of the above-mentioned (b1) to (b3) are used, there are no particular restrictions, but from the viewpoint of heat resistance, insulation reliability, and handling properties during film formation, a combination of (b1) an active ester-based curing agent and (b2) a cyanate ester-based curing agent, and a combination of (b1) an active ester-based curing agent and (b3) a triazine ring-containing phenol novolac-based curing agent are preferable.

Further, 2 or more species of the above-mentioned (b1) may be used in combination, 2 or more species of the above-mentioned (b2) may be used in combination, or 2 or more species of the above-mentioned (b3) may be used in combination.

Active ester curing agent (b1)

(b1) The active ester-based curing agent is not particularly limited as long as it functions as a curing agent for the epoxy resin (a) and has an active ester. When the (b1) active ester curing agent is contained, the dielectric loss tangent tends to be lowered.

As the active ester curing agent (b1), compounds having a curing action of epoxy resin and having a highly reactive ester group such as phenol esters, thiophenol esters, N-hydroxylamine esters and heterocyclic hydroxyl ester compounds can be used.

The active ester curing agent (b1) is preferably a compound having two or more active ester groups in 1 molecule, more preferably an aromatic compound having two or more active ester groups in 1 molecule obtained from a compound having a polycarboxylic acid and an aromatic compound having a phenolic hydroxyl group, and still more preferably an aromatic compound having two or more ester groups in a molecule obtained from a compound having at least two carboxylic acids in 1 molecule and an aromatic compound having a phenolic hydroxyl group. The active ester curing agent (b1) may contain a linear or multi-branched polymer.

The compound having at least two or more carboxylic acids in the molecule 1 can improve the compatibility between the epoxy resin (a) and the cyanate ester resin (b2) if it is a compound containing an aliphatic chain, and can improve the heat resistance if it is a compound having an aromatic ring. In particular, from the viewpoint of heat resistance and the like, the (b1) active ester-based curing agent is preferably an active ester compound obtained from a carboxylic acid compound and a phenol compound or a naphthol compound.

Examples of the carboxylic acid compound include: benzoic acid, acetic acid, succinic acid, maleic acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, pyromellitic acid, and the like. Among these, succinic acid, maleic acid, itaconic acid, phthalic acid, isophthalic acid, and terephthalic acid are preferable, and isophthalic acid and terephthalic acid are more preferable, from the viewpoint of heat resistance.

Examples of the thiocarboxylic acid compound include thioacetic acid and thiobenzoic acid.

Examples of the phenol compound or naphthol compound include: hydroquinone, resorcinol, bisphenol a, bisphenol F, bisphenol S, phenolphthalein (japanese: フェノールフタリン), methylated bisphenol a, methylated bisphenol F, methylated bisphenol S, phenol, o-cresol, m-cresol, p-cresol, catechol, α -naphthol, β -naphthol, 1, 5-dihydroxynaphthalene, 1, 6-dihydroxynaphthalene, 2, 6-dihydroxynaphthalene, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, phloroglucinol, benzenetriol, dicyclopentadiene diphenol, phenol novolac (japanese: フェノールノボラック), and the like. Among these, bisphenol A, bisphenol F, bisphenol S, methylated bisphenol A, methylated bisphenol F, methylated bisphenol S, catechol, 1, 5-dihydroxynaphthalene, 1, 6-dihydroxynaphthalene, 2, 6-dihydroxynaphthalene, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, phloroglucinol, benzenetriphenol, dicyclopentadiene diphenol, phenol novolac are preferable, catechol, 1, 5-dihydroxynaphthalene, 1, 6-dihydroxynaphthalene, 2, 6-dihydroxynaphthalene, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, phloroglucinol, benzenetriphenol, dicyclopentadiene diphenol, phenol novolac are more preferable, 1, 5-dihydroxynaphthalene, 1, 6-dihydroxynaphthalene, 2, 6-dihydroxynaphthalene, dihydroxybenzophenone, tetrahydroxybenzophenone, phloroglucinol, benzenetriol, and benzenenovolac are further preferable, and 1, 5-dihydroxynaphthalene, 1, 6-dihydroxynaphthalene, 2, 6-dihydroxynaphthalene, dihydroxybenzophenone, phenol novolac are further preferable, and the heat resistance and solubility are still more preferable, Trihydroxybenzophenone, tetrahydroxybenzophenone, dicyclopentadiene diphenol, phenol novolaks, particularly preferably dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, dicyclopentadiene diphenol, phenol novolaks, very preferably dicyclopentadiene diphenol, phenol novolaks, most preferably dicyclopentadiene diphenol.

Examples of the thiol compound include benzenedithiol and triazinedithiol.

As the active ester-based curing agent (b1), the active ester-based curing agent disclosed in Japanese patent application laid-open No. 2004-277460 can be used, and a commercially available product can also be used.

Examples of commercially available (b1) active ester-based curing agents include: among these, compounds containing a dicyclopentadiene diphenol structure, acetylates of phenol novolaks, benzoylates of phenol novolaks and the like are preferable. Specifically, examples of the compound having a dicyclopentadiene diphenol structure include: "EXB 9451" (active ester group equivalent: about 220g/eq), "EXB 9460", "EXB 9460S-65T", "HPC-8000-65T" (active ester group equivalent: about 223g/eq) (trade name, available from DIC corporation), as an acetylate of phenol novolac, "DC 808" (available from Mitsubishi chemical corporation, active ester group equivalent: about 149g/eq), and as a benzoylate of phenol novolac, "YLH 1026" (available from Mitsubishi chemical corporation, active ester group equivalent: about 200g/eq), and the like.

(b1) The method for producing the active ester-based curing agent is not particularly limited, and the active ester-based curing agent can be produced by a known method. Specifically, the compound can be obtained by a condensation reaction of a carboxylic acid compound and/or a thiocarboxylic acid compound with a hydroxyl compound and/or a thiol compound.

((b2) cyanate ester-based curing agent)

As the cyanate ester-based curing agent (b2), a known cyanate resin can be used, and as the cyanate resin, for example, preferable are: 1 cyanate ester resin having two or more cyanato groups in the molecule.

Specific examples of the cyanate ester-based curing agent (b2) include: bisphenol type cyanate ester resins such as 2, 2-bis (4-cyanatophenyl) propane [ bisphenol a type cyanate ester resin ], bis (4-cyanatophenyl) ethane [ bisphenol E type cyanate ester resin ], bis (3, 5-dimethyl-4-cyanatophenyl) methane [ tetramethylbisphenol F type cyanate ester resin ], 2-bis (4-cyanatophenyl) -1, 1,1,3,3, 3-hexafluoropropane [ hexafluorobisphenol a type cyanate ester resin ]; dicyclopentadiene type cyanate ester resins such as cyanate ester compounds obtained by adding phenol to dicyclopentadiene polymers; novolac cyanate ester resins such as phenol novolac cyanate ester compounds and cresol novolac cyanate ester compounds; α, α' -bis (4-cyanoylphenyl) -m-diisopropylbenzene; prepolymers of these cyanate resins (hereinafter, also referred to as "cyanate prepolymers") and the like. These may be used alone in 1 kind, or may be used in combination of 2 or more kinds.

Among these, from the viewpoints of heat resistance, insulation reliability, and handling properties at the time of film formation, the cyanate ester resin represented by the following general formula (b 2-I), the cyanate ester resin represented by the following general formula (b 2-IV), and prepolymers thereof are preferable, and the cyanate ester resin represented by the following general formula (b 2-I) and prepolymers thereof are more preferable.

[ solution 14]

In the general formula (b 2-I), R^b1Represents an alkylene group having 1 to 3 carbon atoms optionally substituted with a halogen atom, a sulfur atom, or a 2-valent group represented by the following general formula (b 2-II) or (b 2-III). R^b2And R^b3Represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. Two R^b2To each other or to both R^b3May be the same or different from each other, but preferably the same.

[ solution 15]

In the general formula (b 2-II), R^b4Represents an alkylene group having 1 to 3 carbon atoms. Two R^b4May be the same or different from each other, but are preferably the same.

[ solution 16]

[ solution 17]

In the general formula (b 2-IV), R^b5Represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms which may be substituted with a halogen atom. n represents an integer of 1 or more. Two or more R^b5May be the same or different from each other, but are preferably the same.

In the above general formula (b 2-I), R is^b1The alkylene group having 1 to 3 carbon atoms includes: methylene, ethylene, 1, 2-propylene, 1, 3-propylene, 2-propylene (-C (CH)₃)₂-) and the like. Among these, methylene group or 2, 2-propylene group (-C (CH) is preferable from the viewpoints of heat resistance, insulation reliability, and handling property in film formation₃)₂-) and more preferably 2, 2-propylene (-C (CH)₃)₂－)。

Examples of the halogen atom substituted for the alkylene group having 1 to 3 carbon atoms include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like.

In the above general formula (b 2-II), R is^b4The alkylene group having 1 to 3 carbon atoms includes: methylene, ethylene, 1, 2-propylene, 1, 3-propylene, 2-propylene (-C (CH)₃)₂-) and the like.

These R^b1Among the groups, methylene group or 2, 2-propylene group (-C (CH) is preferable from the viewpoints of heat resistance, insulation reliability, and handling property in film formation₃)₂-) and more preferably 2, 2-propylene (-C (CH)₃)₂－)。

In the above general formula (b 2-I), R is^b2Or R^b3Examples of the alkyl group having 1 to 4 carbon atoms include methyl, ethyl, propyl, and butyl groups.

In the above general formula (b 2-IV), R is^b5Examples of the alkyl group having 1 to 3 carbon atoms include methyl, ethyl, and propyl.

Examples of the halogen atom substituted for the alkyl group having 1 to 3 carbon atoms include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like.

In the general formula (b 2-IV), n represents an integer of 1 or more, and is preferably 1 to 7, more preferably 1 to 4, from the viewpoints of heat resistance, insulation reliability, and handling properties during film formation.

The cyanate ester prepolymer is a polymer in which cyanate ester resins form a triazine ring by cyclization reaction, and mainly includes: 3,5, 7, 9, 11-mers of cyanate ester compounds, and the like. In the cyanate ester prepolymer, the conversion rate of the cyanato group is not particularly limited, but is preferably 20 to 70% by mass, more preferably 30 to 65% by mass, from the viewpoint of obtaining good solubility in an organic solvent.

Examples of the cyanate ester prepolymer include: a prepolymer of the cyanate ester resin represented by the above general formula (b 2-I), a prepolymer of the cyanate ester resin represented by the above general formula (b 2-IV), and the like. Among these, from the viewpoint of heat resistance, insulation reliability, and handling properties at the time of film formation, a prepolymer of a dicyanate ester compound having two cyanato groups in 1 molecule is preferable, a prepolymer of a cyanate ester resin represented by the above general formula (b 2-I) is more preferable, and a prepolymer in which at least a part of 2, 2-bis (4-cyanatophenyl) propane is triazinized to a trimer is further preferable (see the following formula (b 2-V)).

[ solution 18]

The weight average molecular weight (Mw) of the cyanate ester prepolymer is not particularly limited, but is preferably 500 to 4,500, more preferably 600 to 4,000, even more preferably 1,000 to 4,000, and particularly preferably 1,500 to 4,000, from the viewpoint of solubility in organic solvents and workability. When the weight average molecular weight (Mw) of the cyanate ester prepolymer is 500 or more, crystallization of the cyanate ester prepolymer tends to be suppressed and the solubility in an organic solvent tends to be good, and when it is 4,500 or less, increase in viscosity tends to be suppressed and workability tends to be excellent.

In the present invention, the weight average molecular weight (Mw) is measured by Gel Permeation Chromatography (GPC) (manufactured by tokyo co., ltd.) using a calibration curve of standard polystyrene, and specifically, is measured according to the method described in the examples.

The cyanate ester prepolymer may be obtained by prepolymerizing the above cyanate ester resin in the presence of a monofunctional phenol compound. When a cyanate ester prepolymer is produced, a monofunctional phenol compound is added, so that unreacted cyanato groups in the resulting cured product can be reduced, and therefore, the cured product tends to have excellent moisture resistance and electrical characteristics.

Examples of the monofunctional phenol compound include: alkyl-substituted phenol compounds such as p-nonylphenol, p-tert-butylphenol, p-tert-amylphenol, and p-tert-octylphenol; and phenol-based compounds represented by the following general formula (b 2-VI), such as p- (. alpha. -cumyl) phenol, mono- (. alpha. -methylbenzyl) phenol, di- (. alpha. -methylbenzyl) phenol, and tri- (. alpha. -methylbenzyl) phenol. These may be used alone in 1 kind, or may be used in combination of 2 or more kinds.

[ solution 19]

In the general formula (b 2-VI), R^b6And R^b7Each independently represents a hydrogen atom or a methyl group, and m represents an integer of 1 to 3. When m is an integer of 2 or 3, two or more R^b6Each other or R^b7May be the same or different from each other, but preferably the same.

The amount of the monofunctional phenol compound to be used is preferably an amount such that the equivalent ratio of the phenolic hydroxyl group of the monofunctional phenol compound to the cyanato group of the cyanate ester resin (hydroxyl group/cyanato group) is 0.01 to 0.30, more preferably 0.01 to 0.20, and still more preferably 0.01 to 0.15. When the amount of the monofunctional phenol compound used is within the above range, not only a material having a sufficiently low dielectric loss tangent particularly in a high frequency band but also good moisture resistance tends to be obtained.

The method for producing the cyanate ester prepolymer is not particularly limited, and a known production method can be applied.

The cyanate ester prepolymer can be suitably produced by, for example, reacting the dicyanate ester compound with the monofunctional phenol compound. The reaction of the dicyanate compound with the monofunctional phenol compound forms a compound having a group represented by-O-C (═ NH) -O- (i.e., imino carbonate), and the imino carbonates are further reacted with each other or the imino carbonate is reacted with the dicyanate compound, whereby the monofunctional phenol compound is eliminated, and on the other hand, a cyanate ester prepolymer having a triazine ring is obtained. The above reaction can be carried out, for example, as follows: the dicyanate compound and the monofunctional phenol compound are mixed and dissolved in the presence of a solvent such as toluene, and the mixture is maintained at 80 to 120 ℃ while adding a reaction accelerator such as zinc naphthenate as needed.

As the cyanate ester resin, commercially available products can be used. As commercially available cyanate ester resins, there are bisphenol type cyanate ester resins, novolac type cyanate ester resins, prepolymers in which a part or all of the cyanate ester resins are converted to a trimer by triazining, and the like.

As commercially available products of bisphenol A type (2, 2-bis (4-hydroxyphenyl) propane type) cyanate ester resins, "Primaset BADCy" (product name, manufactured by Lonza) and "arc B-10" (product name, manufactured by Huntsman) can be used. Further, as a commercially available bisphenol E type (1, 1-bis (4-hydroxyphenyl) ethane type) cyanate ester resin, "Arocy L10" (trade name, manufactured by Huntsman corporation) or "Primaset LECy" (trade name, manufactured by Lonza corporation) may be used, and as a commercially available 2, 2' -bis (4-cyanate-3, 5-methylphenyl) ethane type cyanate ester resin, "Primaset methyl lcy" (manufactured by Lonza corporation) or the like may be used.

As a commercially available product of the phenol novolac type cyanate ester resin, "Primaset PT 30" (trade name, manufactured by Lonza corporation) or the like as a phenol novolac type cyanate ester resin can be used.

As commercially available products of the cyanate ester resin prepolymer, "Primaset BA 200" (trade name, manufactured by Lonza) and "Primaset BA 230S" (trade name, manufactured by Lonza) obtained by prepolymerizing a bisphenol A type cyanate ester resin may be used, and "Primaset BA 3000" may also be used.

In addition, as the cyanate ester resin having a dicyclopentadiene structure, "aromatic XU-371" (trade name, manufactured by Huntsman corporation), "aromatic XP71787.02L" (trade name, manufactured by Huntsman corporation), "Primaset DT-4000" (trade name, manufactured by Lonza corporation), "Primaset DT-7000" (trade name, manufactured by Lonza corporation), and the like can be used.

((b3) phenol novolak curing agent containing a triazine ring)

As the triazine ring-containing phenol novolac-based curing agent (b3), a triazine ring-containing phenol novolac-based curing agent can be used among novolac-based phenolic resins used as curing agents for epoxy resins. The triazine ring-containing phenol novolak resin is a resin in which an aminotriazine ring structure and a phenol structure are randomly bonded via a methylene group. The triazine ring-containing phenol novolac-based curing agent is preferably at least one of a triazine ring-containing phenol novolac resin and a triazine ring-containing cresol novolac resin.

The triazine ring-containing phenol novolac resin can be produced, for example, by the production method described in jp 2002-a 226556. That is, the phenol compound, the aminotriazine compound and the aldehyde compound can be produced by causing a copolycondensation reaction in the presence of a weakly basic catalyst such as alkylamine or in the vicinity of neutrality without a catalyst.

As the phenol compound used as the raw material, there may be mentioned: phenol, o-cresol, m-cresol, p-cresol, xylenol, bisphenol compounds, ortho-substituted phenol compounds having an ortho-position hydrocarbon group having 3 or more carbon atoms, preferably 3 to 10 carbon atoms, para-substituted phenol compounds having a para-position hydrocarbon group having 3 or more carbon atoms, preferably 3 to 18 carbon atoms, and the like. These may be used alone in 1 kind, or may be used in combination of 2 or more kinds.

Here, as the bisphenol compound, there may be mentioned: bisphenol A, bisphenol F, bis (2-methylphenol) A, bis (2-methylphenol) F, bisphenol S, bisphenol E, bisphenol Z and the like.

Examples of the ortho-substituted phenol compound include: 2-propylphenol, 2-isopropylphenol, 2-sec-butylphenol, 2-tert-butylphenol, 2-phenylphenol, 2-cyclohexylphenol, 2-nonylphenol, 2-naphthylphenol and the like.

Examples of the para-substituted phenol compound include: 4-propylphenol, 4-isopropylphenol, 4-sec-butylphenol, 4-tert-butylphenol, 4-phenylphenol, 4-cyclohexylphenol, 4-nonylphenol, 4-naphthylphenol, 4-dodecylphenol, 4-octadecylphenol and the like.

Examples of the aminotriazine compound used as a raw material include melamine, benzoguanamine, acetoguanamine, and the like.

As the aldehyde compound used as the raw material, there may be mentioned: formaldehyde, formalin, paraformaldehyde, trioxymethylene, acetaldehyde, paraldehyde, propionaldehyde and the like. Among these, paraformaldehyde is preferable from the viewpoint of the reaction rate. These may be used alone in 1 kind, or may be used in combination of 2 or more kinds.

The molar ratio (F/P) of the aldehyde compound (F) to the phenol compound (P) is preferably 0.33 or more, more preferably 0.40 to 1.0, and still more preferably 0.50 to 0.90. When the blending molar ratio (F/P) is within the above range, an excellent yield can be obtained.

The nitrogen atom content in the triazine ring-containing phenol novolac-based curing agent (b3) is preferably 8 to 30%, more preferably 8 to 20%.

As the triazine ring-containing phenol novolak curing agent (b3), commercially available products can be used, and examples thereof include: "PAPS-PN 2" (trade name, manufactured by Asahi organic materials industries Co., Ltd.), "PAPS-PN 3" (trade name, manufactured by Asahi organic materials industries Co., Ltd.), "Phenolate LA-1356" (trade name, manufactured by DIC Co., Ltd.), "Phenolate LA-7054" (triazine-containing phenol novolak resin, manufactured by DIC Co., Ltd.), "Phenolate LA-3018" (triazine-containing cresol novolak resin, manufactured by DIC Co., Ltd.; trade name), and the like.

The curing agent (b) of the resin composition for an interlayer insulating layer used in the present invention may contain an epoxy resin curing agent (hereinafter, also simply referred to as "epoxy resin curing agent") other than the curing agents (b1) to (b3) described above, within a range not to impair the effects of the present invention.

Examples of the epoxy resin curing agent include: phenol resins containing no triazine ring, phenol compounds containing phosphorus, acid anhydride compounds, amine compounds, hydrazide compounds, and the like.

Examples of the phenol resin not containing a triazine ring include: phenol novolac type resins, resol type resins, and the like. The phosphorus-containing phenol compound is a compound having two or more phenolic hydroxyl groups and containing a phosphorus atom, and examples thereof include 10- (2, 5-dihydroxyphenyl) -9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide [ HCA-HQ or HCA-HQ-HS (trade name, manufactured by Sanko Co., Ltd.) ]. Examples of the acid anhydride compound include: phthalic anhydride, benzophenone tetracarboxylic dianhydride, methyl nadic acid, and the like. In addition, examples of the amine compound include: dicyandiamide, diaminodiphenylmethane, guanylurea, and the like.

Among these epoxy resin curing agents, phenol resins containing no triazine ring and phenol compounds containing phosphorus are preferable from the viewpoint of improving reliability, and phenol compounds containing phosphorus are more preferable from the viewpoint of flame retardancy.

In the present invention, a substance having a function as a curing agent and another function is classified as a "curing agent" in preference to a substance having a function as a curing agent. For example, the phosphorus-containing phenol compound has a function as a curing agent and a function as a flame retardant, and is classified as a curing agent.

(b) The curing agent may include (b2) a cyanate-based curing agent, and may include at least 1 selected from (b1) an active ester-based curing agent and (b3) a triazine ring-containing phenol novolac-based curing agent. In particular, it is preferable to include at least 1 kind selected from the group consisting of (b1) an active ester-based curing agent and (b3) a triazine ring-containing phenol novolac-based curing agent because the effect of suppressing the easy gelation caused by a phosphorus-containing phenol compound described later is large. That is, when it is intended to use a phosphorus-containing phenol compound having both the effect as a curing agent and the effect of flame retardancy, gelation can be suppressed and the workability in film formation can be satisfactorily maintained by using at least 1 kind selected from (b1) an active ester-based curing agent and (b3) a triazine ring-containing phenol novolac-based curing agent in combination. From the same viewpoint, the curing agent (b) preferably contains a phenol novolac-based curing agent (b3) containing a triazine ring.

(b) The content of the active ester-based curing agent (b1), the cyanate ester-based curing agent (b2), and the triazine ring-containing phenol novolac-based curing agent (b3) in the curing agent is not particularly limited, and when the component (b1) is used in combination with the component (b2) or the component (b3), the component (b1) is preferably 40 to 70 mass%, more preferably 50 to 65 mass%, relative to the total amount of the components (b1) to (b3) used, from the viewpoint of dielectric properties.

(b) The mass ratio of the total amount of the above-mentioned (b1) to (b3) components in the curing agent is preferably 20 mass% or more, more preferably 40 mass% or more, and still more preferably 50 mass% or more, from the viewpoints of heat resistance, insulation reliability, and workability in film formation. The upper limit is not particularly limited, and may be 100 mass%, 90 mass%, or 80 mass%.

The content ratio of the epoxy resin (a) and the curing agent (b) in the resin composition for an interlayer insulating layer is preferably adjusted so that the ratio of the total number of functional groups of the curing agent (b) to the total number of epoxy groups of the epoxy resin (a) [ (total number of functional groups of the curing agent (b)/(total number of epoxy groups of the epoxy resin (a)) is 0.2 to 2, from the viewpoints of heat resistance, insulation reliability, and workability in film formation. When the ratio is 0.2 or more, the amount of unreacted epoxy groups in the obtained interlayer insulating layer tends to be reduced, and when the ratio is 2 or less, the amount of (b) the curing agent is not excessively added, and the increase in curing temperature tends to be suppressed. From the same viewpoint, the ratio is more preferably 0.4 to 1.5.

[ (c) inorganic Filler ]

The resin composition for an interlayer insulating layer used in the present invention further contains (c) an inorganic filler. The (c) inorganic filler is important in that the interlayer insulating layer formed by thermally curing the resin composition for an interlayer insulating layer is processed with a laser beam, the resin is prevented from scattering, and the shape of the laser beam processed can be adjusted. In addition, it is important to form a suitably roughened surface when roughening the surface of the interlayer insulating layer with an oxidizing agent, and a conductor layer having excellent adhesive strength can be formed by plating.

Examples of the (c) inorganic filler include: silica, alumina, barium sulfate, talc, clay, mica powder, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium oxide, boron nitride, aluminum borate, barium titanate, strontium titanate, calcium titanate, bismuth titanate, titanium oxide, barium zirconate, calcium zirconate, and the like. Among these, silica, particularly spherical silica and fused silica are preferable from the viewpoints of the thermal expansion coefficient, the workability of varnish and the insulation reliability. The inorganic filler may be used alone in 1 kind, or may be used in combination in 2 or more kinds.

(c) The inorganic filler is preferably an inorganic filler having a small particle diameter from the viewpoint of forming fine wiring. From the same viewpoint, the inorganic filler (c) preferably has a specific surface area of 3m²More than g, and may be 3 to 200m²A/g of 3 to 130m²A/g, which may be 3 to 50m²A/g, which may be 3 to 20m²(ii) in terms of/g. The specific surface area can be determined by the BET method based on low-temperature low-humidity physical adsorption of an inert gas. Specifically, molecules having a known adsorption occupation area of nitrogen gas or the like are adsorbed on the surfaces of the powder particles at a liquid nitrogen temperature, and the specific surface area of the powder particles can be determined from the adsorption amount.

The volume average particle diameter of the inorganic filler (c) is preferably 0.01 to 5 μm, more preferably 0.1 to 2 μm, and still more preferably 0.2 to 1 μm, from the viewpoint of obtaining good embeddability of the circuit board and insulation reliability. The volume average particle diameter means: when a cumulative frequency distribution curve based on the particle diameter is obtained with the total volume of the particles set to 100%, the particle diameter of the point corresponding to 50% by volume can be measured by a particle size distribution measuring apparatus using a laser diffraction scattering method or the like.

As the (c) inorganic filler, commercially available products can be used, and examples thereof include: "AEROSIL (registered trademark) R972" (product name, specific surface area 110. + -.20 m, manufactured by Nippon AEROSIL Co., Ltd.) as fumed silica²(g) 'AEROSIL (registered trademark) R202' (trade name, specific surface area 100. + -.20 m, manufactured by Nippon AEROSIL Co., Ltd.)²(g) 'PL-1' (product name, specific surface area 181m, manufactured by Hibiscus chemical Co., Ltd.) as colloidal silica²(g) and "PL-7" (trade name, specific surface area 36m, manufactured by Hibiscus chemical Co., Ltd.)²,/g), etc.

As the inorganic filler (c), an inorganic filler surface-treated with a surface-treating agent such as a silane coupling agent can be used from the viewpoint of improving the moisture resistance of the resulting interlayer insulating layer.

As the inorganic filler surface-treated with the surface-treating agent, commercially available products can be used, and examples thereof include: "SO-C2" (trade name, manufactured by Admatechs, japan) as a silica filler treated with an aminosilane coupling agent, "YC 100C" (trade name, manufactured by Admatechs, japan) as a silica filler treated with a phenylsilane coupling agent, and "Sciqas series" (trade name, 0.1 μm grade, manufactured by sakai chemical industry co., japan) as a silica filler treated with an epoxy silane coupling agent.

The content of the inorganic filler (c) in the resin composition for an interlayer insulating layer is preferably 30 to 90% by mass, more preferably 30 to 70% by mass, and still more preferably 40 to 60% by mass, based on the solid content of the resin composition for an interlayer insulating layer (including the inorganic filler (c) itself), from the viewpoints of laser processability of the resulting interlayer insulating layer and adhesion strength to a conductor layer. When the content of the (c) inorganic filler is 30 mass% or more relative to the solid content of the resin composition for an interlayer insulating layer, good laser processability tends to be obtained, and when the content is 90 mass% or less, the adhesive strength with a conductor layer formed by a plating method tends to be excellent.

[ (d) antioxidant ]

The antioxidant (d) contained in the resin composition for an interlayer insulating layer is a hindered phenol antioxidant. The hindered phenol antioxidant has a substituent at the ortho position of the phenolic hydroxyl group, and particularly, it tends to mean a compound having a substituent having a large steric hindrance such as a tert-butyl group and a trimethylsilyl group.

The resin composition for an interlayer insulating layer does not necessarily contain a non-hindered phenol antioxidant, and when a non-hindered phenol antioxidant is contained, the content of the non-hindered phenol antioxidant is preferably 30% by mass or less, more preferably 15% by mass or less, further preferably 5% by mass or less, and may be 0% by mass of the content of the hindered phenol antioxidant.

By using the antioxidant (d) as a hindered phenol antioxidant, the workability in film formation is improved.

Examples of the hindered phenol antioxidant include: 2, 6-di-t-butyl-p-cresol (trade name: Yoshinox BHT), 4 ' -butylidenebis- (6-t-butyl-3-methylphenol) (trade name: Yoshinox BB), 2 ' -methylenebis- (4-methyl-6-t-butylphenol) (trade name: Yoshinox 2246G), 2 ' -methylenebis- (4-ethyl-6-t-butylphenol) (trade name: Yoshinox 425), 2, 6-di-t-butyl-4-ethylphenol (trade name: Yoshinox 250), 1, 3-tris (2-methyl-4-hydroxy-5-t-butylphenyl) butane (trade name: Yoshinox 930), n-octadecyl-3- (3, 5-di-t-butyl-4-hydroxyphenyl) propionate (trade name: Tominox SS, IRGANOX1076FD), pentaerythrityl ■ tetrakis [ 3- (3, 5-di-t-butyl-4-hydroxyphenyl) propionate ] (trade name: IRGANOX 1010; IRGANOX 1073926), IRGANOX1010FF), triethylene glycol bis [ 3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionate ] (trade name: tominox 917; IRGANOX245, IRGANOX245FF), tris (3, 5-di-tert-butyl-4-hydroxybenzyl) isocyanurate (trade name: yoshinox 314; IRGANOX3114), 1, 6-hexanediol-bis [ 3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ] (trade name: IRGANOX259), 2, 4-bis- (n-octylthio) -6- (4-hydroxy-3, 5-di-tert-butylanilino) -1, 3, 5-triazine (trade name: IRGANOX565, IRGANOX565DD), 2-thio-diethylene bis [ 3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ] (trade name: IRGANOX1035FF), N' -hexamethylenebis [ 3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propanoic acid amide ] (trade name: IRGANOX1098), 1,3, 5-trimethyl-2, 4, 6-tris (3, 5-di-tert-butyl-4-hydroxybenzyl) benzene (trade name: IRGANOX1330), calcium bis (ethyl 3, 5-di-tert-butyl-4-hydroxybenzylphosphonate) (trade name: IRGANOX1425WL), 2, 4-bis [ (octylthio) methyl ] o-cresol (trade name: IRGANOX1520L), isooctyl-3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate (trade name: IRGANOX1135), and the like.

The hindered phenol-based antioxidant preferably contains at least 1 selected from the group consisting of a compound having a group represented by the following general formula (dI) and a compound represented by the following general formula (dII). The compound having a group represented by the following general formula (dI) may include a compound represented by the following general formula (dII).

[ solution 20]

(in the formula (dI), R^d1、R^d2And R^d3Each independently represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. Wherein R is^d1And R^d2At least 1 of them represents an alkyl group having 1 to 8 carbon atoms. )

[ solution 21]

(in the formula (dII), R^d4And R^d5Each independently represents an alkyl group having 1 to 8 carbon atoms. R^d6、R^d7And R^d8Each independently represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. Wherein R is^d6、R^d7And R^d8At least 1 of them represents an alkyl group having 1 to 8 carbon atoms. )

In the formula (dI), as R^d1、R^d2And R^d3Examples of the alkyl group having 1 to 8 carbon atoms include: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-hexyl, n-octyl and the like. Among these, an alkyl group having 1 to 6 carbon atoms is preferable, an alkyl group having 1 to 4 carbon atoms is more preferable, a methyl group, an ethyl group, an n-propyl group, and a tert-butyl group are further preferable, and a methyl group, an ethyl group, and a tert-butyl group are particularly preferable.

R^d1And R^d2At least 1 of them represents an alkyl group having 1 to 8 carbon atoms. May be R^d1Is C1-8 alkyl, R^d2Is a combination of hydrogen atoms, and may be R^d1Is a hydrogen atom, R^d2A combination of C1-C8 alkyl groups, or R^d1And R^d2Both are C1-C8 alkyl groups.

Formula (dII)) In (1) as R^d4、R^d5、R^d6、R^d7And R^d8An alkyl group having 1 to 8 carbon atoms represented by the formula and R^d1、R^d2And R^d3The same applies to the preferred examples.

R^d6、R^d7And R^d8At least 1 of them represents an alkyl group having 1 to 8 carbon atoms, and preferably two of them represent an alkyl group having 1 to 8 carbon atoms. May be R^d6Is a hydrogen atom, R^d7Is a hydrogen atom and R^d8Is a combination of C1-C8 alkyl, and can be R^d6Is a hydrogen atom, R^d7Is C1-C8 alkyl and R^d8Is a combination of hydrogen atoms, and may be R^d6Is C1-8 alkyl, R^d7Is a hydrogen atom and R^d8Is a combination of hydrogen atoms, and may be R^d6Is C1-8 alkyl, R^d7Is a hydrogen atom and R^d8Is a combination of hydrogen atoms, and may be R^d6Is C1-8 alkyl, R^d7Is C1-C8 alkyl and R^d8Is a combination of hydrogen atoms, and may be R^d6Is C1-8 alkyl, R^d7Is a hydrogen atom and R^d8Is a combination of C1-C8 alkyl, and can be R^d6Is a hydrogen atom, R^d7Is C1-C8 alkyl and R^d8The alkyl group has 1 to 8 carbon atoms. R^d6、R^d7And R^d8All of the alkyl groups may be C1-C8 alkyl groups.

The compound having a group represented by the above general formula (dI) is preferably a compound represented by any of the following general formulae (dI-1) to (dI-3).

[ solution 22]

(in formulae (dI-1) and (dI-2), R^d11、R^d12、R^d13、R^d21、R^d22And R^d23Each independently represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. Wherein R is^d11And R^d12At least 1 of (1), and R^d21And R^d22At least 1 of them represents an alkyl group having 1 to 8 carbon atoms. X¹And X²Each independently represents an organic group having a valence of 1 to 3. n is¹And n²Each independently is an integer of 1 to 3. )

For alkyl group having 1 to 8 carbon atoms, with the above R^d1、R^d2And R^d3The same applies to the preferred examples.

R^d11And R^d12At least 1 of them represents an alkyl group having 1 to 8 carbon atoms. May be R^d11Is C1-8 alkyl, R^d12Is a combination of hydrogen atoms, and may be R^d11Is a hydrogen atom, R^d12Is a combination of C1-C8 alkyl, and can be R^d11And R^d12Both are C1-C8 alkyl groups. Preferably R^d11And R^d12Both are tert-butyl and R^d13Is a combination of hydrogen atoms.

In addition, R is also preferable^d11Is a hydrogen atom, R^d12Is C1-8 alkyl, R^d13A combination of C1-C8 alkyl, more preferably R^d11Is a hydrogen atom, R^d12Is tert-butyl, R^d13Is a combination of methyl groups.

R^d21And R^d22At least 1 of them represents an alkyl group having 1 to 8 carbon atoms. May be R^d21Is C1-8 alkyl, R^d22Is a combination of hydrogen atoms, and may be R^d21Is a hydrogen atom, R^d22Is a combination of C1-C8 alkyl, and can be R^d21And R^d22Both are C1-C8 alkyl groups. Preferably R^d21Is tert-butyl, R^d22Is ethyl, R^d23Is a combination of hydrogen atoms.

In addition, R is^d13Is a hydrogen atom and has no substituent R^d13Synonymously. In addition, R^d23Is a hydrogen atom and has no substituent R^d23Synonymously.

As X¹And X²The 1 to 3-valent organic group is not particularly limited, and examples thereof include: aliphatic hydrocarbon group, amide bond-containing group, aromatic hydrocarbon group, heteroaromatic hydrocarbon group, and combination thereofThe resulting radical.

The aliphatic hydrocarbon group is preferably an aliphatic hydrocarbon group having 1 to 10 carbon atoms, more preferably an aliphatic hydrocarbon group having 1 to 6 carbon atoms, and still more preferably an aliphatic hydrocarbon group having 1 to 4 carbon atoms. The aliphatic hydrocarbon group may be linear or branched.

Examples of the amide bond-containing group include- (CH)₂)₂－C(＝O)－NH－(CH₂)₆－NH－C(＝O)－(CH₂)₂-and the like.

The aromatic hydrocarbon group is preferably an aromatic hydrocarbon group having 6 to 10 carbon atoms, and more preferably an aromatic hydrocarbon group having 6 carbon atoms.

Examples of the heteroaromatic hydrocarbon group include groups having an isocyanurate skeleton.

Specific examples of the group formed by a combination of these include an aliphatic hydrocarbon group and an aromatic hydrocarbon group.

n¹And n²Each independently represents an integer of 1 to 3, may be 1, may be 2, or may be 3.

[ solution 23]

(in the formula (dI-3), R^d31And R^d32Each independently represents an alkyl group having 1 to 8 carbon atoms. Y represents-COOCH₂－、－COOCH₂CH₂－。)

As R^d31And R^d32An alkyl group having 1 to 8 carbon atoms represented by the formula and R^d1、R^d2And R^d3The same applies to the preferred examples. Among them, tert-butyl is particularly preferable.

As the compound having a group represented by the above general formula (dI), preferred are: at least 1 kind of compound selected from the compounds represented by the general formula (dI-1) and the compounds represented by the general formula (dI-2), and the molecular weight is less than 1,500. More preferably: at least 1 kind selected from the compounds represented by the general formula (dI-1) and the compounds represented by the general formula (dI-2), and has a molecular weight of 1,000 or less, more preferably 500 or less, and particularly preferably 400 or less.

[ (d') the following specific Compound ]

The resin composition for an interlayer insulating layer may contain the component (d') in place of the component (d). The component (d') is at least 1 selected from the group consisting of a compound having a group represented by the above general formula (dI) and a compound represented by the above general formula (dII). The groups in general formula (dI) and general formula (dII) are as defined above, and preferred examples are the same.

In particular, the compound having a group represented by the general formula (dI) is preferably a compound represented by any of the general formulae (dI-1) to (dI-3). In addition, it is preferable that: the compound having a group represented by the general formula (dI) is at least 1 selected from the group consisting of the compound represented by the general formula (dI-1) and the compound represented by the general formula (dI-2), and has a molecular weight of 1,500 or less. More preferably: at least 1 kind selected from the compounds represented by the general formula (dI-1) and the compounds represented by the general formula (dI-2), and has a molecular weight of 1,000 or less, more preferably 500 or less, and particularly preferably 400 or less.

The content of the component (d) or the component (d') in the resin composition for an interlayer insulating layer is preferably 0.01 to 10% by mass, more preferably 0.05 to 5% by mass, even more preferably 0.05 to 2% by mass, and particularly preferably 0.05 to 1% by mass, based on the solid content of the resin composition for an interlayer insulating layer, from the viewpoints of heat resistance, insulation reliability, and handling properties in film formation.

[ (e) phenoxy resin ]

The resin composition for an interlayer insulating layer preferably contains (e) a phenoxy resin.

Here, the term "phenoxy resin" refers to a generic term for polymers having a main chain of an addition polymerization structure of an aromatic diol and an aromatic diglycidyl ether, and in the present specification, refers to phenoxy resins having a weight average molecular weight of 10,000 or more. When a polymer having a main chain of an addition polymerization structure of an aromatic diol and an aromatic diglycidyl ether has an epoxy group, a phenoxy resin (e) having a weight average molecular weight of 10,000 or more and an epoxy resin (a) having a weight average molecular weight of less than 10,000 are classified.

From the viewpoint of improving the handling properties at the time of film formation, the phenoxy resin (e) preferably contains an alicyclic structure. Here, the "alicyclic structure" means: a portion obtained by removing an aromatic compound from an organic compound having a structure in which carbon atoms are bonded to form a ring ". Among these, 1 or more selected from cyclic saturated hydrocarbons (cycloalkanes) and cyclic unsaturated hydrocarbons (cycloalkenes) containing 1 double bond in the ring are preferable.

Examples of the phenoxy resin (e) include: phenoxy resins containing a cyclohexane structure, phenoxy resins containing a trimethylcyclohexane structure, phenoxy resins containing a terpene structure, and the like. Among these, from the viewpoint of improving the workability in film formation, a phenoxy resin containing 1 or more selected from a terpene structure and a trimethylcyclohexane structure is preferable, and a phenoxy resin containing a trimethylcyclohexane structure is more preferable.

Examples of the phenoxy resin having a trimethylcyclohexane structure include: a phenoxy resin using bisphenol TMC (bis (4-hydroxyphenyl) -3, 3, 5-trimethylcyclohexane) as a raw material, which is disclosed in Japanese patent laid-open No. 2006-176658.

Examples of the phenoxy resin having a terpene structure include: in the phenoxy resin disclosed in Japanese patent laid-open No. 2006-176658, a phenoxy resin synthesized using terpene diol in place of a 2-membered phenol compound using bis (4-hydroxyphenyl) -3, 3, 5-trimethylcyclohexane as a raw material, and the like are used.

(e) The phenoxy resin may be used alone in 1 kind, or in combination of 2 or more kinds.

(e) The weight average molecular weight of the phenoxy resin is preferably 10,000 to 60,000, more preferably 12,000 to 50,000, further preferably 15,000 to 45,000, particularly preferably 17,000 to 40,000, and most preferably 20,000 to 37,000. When the weight average molecular weight of the phenoxy resin (e) is not less than the lower limit, excellent peel strength with the conductor layer tends to be obtained, and when the weight average molecular weight is not more than the upper limit, increase in roughness and increase in thermal expansion coefficient can be prevented.

The weight average molecular weight is a value measured by a Gel Permeation Chromatography (GPC) method (in terms of polystyrene), and can be measured by the method described in examples.

The method for producing the phenoxy resin (e) can be produced, for example, by the following method: a bisphenol compound having a trimethylcyclohexane structure or a bisphenol compound having a terpene structure and a 2-functional epoxy resin are used as raw materials, and the raw materials are reacted in accordance with a known method for producing a phenoxy resin in such a manner that the equivalent ratio of a phenolic hydroxyl group to an epoxy group (phenolic hydroxyl group/epoxy group) is, for example, 1/0.9 to 1/1.1.

(e) The phenoxy resin may be a commercially available resin. As the commercially available phenoxy resin (e), preferred are: "YX 7200B 35" (trade name, product of mitsubishi chemical corporation) containing a skeleton derived from a biphenyl-type epoxy resin and a bisphenol compound having a trimethylcyclohexane structure (1, 1-bis (4-hydroxyphenyl) -3, 3, 5-trimethylcyclohexane).

When the resin composition for an interlayer insulating layer contains (e) a phenoxy resin, the content thereof is preferably 0.2 to 30 parts by mass, more preferably 1 to 20 parts by mass, and still more preferably 3 to 20 parts by mass, per 100 parts by mass of the solid content of the resin composition for an interlayer insulating layer (herein, the inorganic filler (c)) is removed. When the content of the phenoxy resin (e) is 0.2 parts by mass or more, the flexibility and workability are excellent, and the peel strength of the conductor layer tends to be excellent, and when the content is 20 parts by mass or less, the storage stability and fluidity are excellent, and an appropriate thickness tends to be obtained.

[ (f) curing Accelerator ]

The resin composition for an interlayer insulating layer may contain (f) a curing accelerator, from the viewpoint of enabling curing at a low temperature for a short time.

Examples of the curing accelerator (f) include a metal curing accelerator, an organic curing accelerator, and the like.

(Metal-based curing accelerator)

As the metal-based curing accelerator, for example, an organometallic curing accelerator can be used. The organometallic curing accelerator has (b2) an accelerating action of a self-polymerization reaction of a cyanate-based curing agent and (a) an accelerating action of a reaction of an epoxy resin and (b) a curing agent.

Examples of the organometallic curing accelerator include transition metals, organometallic salts of group 12 metals, and organometallic complexes. Examples of the metal include copper, cobalt, manganese, iron, nickel, zinc, and tin.

Examples of the organic metal salt include a carboxylate, and specific examples thereof include: naphthenates such as cobalt naphthenate and zinc naphthenate, 2-ethylhexanoates such as cobalt 2-ethylhexanoate and zinc 2-ethylhexanoate, zinc octanoate, tin stearate, and zinc stearate.

Examples of the organic metal complex include chelate complexes such as acetylacetone complexes, and specific examples thereof include: organic cobalt complexes such as cobalt (II) acetylacetonate and cobalt (III) acetylacetonate; organic copper complexes such as copper (II) acetylacetonate; organic zinc complexes such as zinc (II) acetylacetonate; organic iron complexes such as iron (III) acetylacetonate, and organic nickel complexes such as nickel (II) acetylacetonate; and organic manganese complexes such as manganese (II) acetylacetonate. Among these, cobalt (II) acetylacetonate, cobalt (III) acetylacetonate, zinc (II) acetylacetonate, iron (III) acetylacetonate, zinc naphthenate, and cobalt naphthenate are preferable, and zinc naphthenate is more preferable, from the viewpoint of curability and solubility. These may be used alone in 1 kind, or may be used in combination of 2 or more kinds.

When the resin composition for an interlayer insulating layer contains a metal-based curing accelerator, the content thereof is preferably 1 to 500 mass ppm, more preferably 10 to 500 mass ppm, even more preferably 50 to 400 mass ppm, and particularly preferably 150 to 300 mass ppm, relative to the cyanate ester-based curing agent (b2), from the viewpoints of reactivity and storage stability. The metal-based curing accelerator may be compounded at one time or in several times.

(organic curing accelerator)

Examples of the organic curing accelerator (which does not contain the organometallic curing accelerator) include: amine compounds such as organic phosphorus compounds, imidazole compounds, secondary amines, and tertiary amines; quaternary ammonium salts, and the like. These may be used alone in 1 kind, or may be used in combination of 2 or more kinds. Among these, from the viewpoint of the removal of the smear from the inside of the via hole, organic phosphorus compounds, imidazole compounds and amine compounds are preferable, and organic phosphorus compounds are more preferable. The organic curing accelerator may be compounded at one time or in several times.

As the organic phosphorus compound, there may be mentioned: ethylphosphine, propylphosphine, butylphosphine, phenylphosphine, trimethylphosphine, triethylphosphine, tributylphosphine, trioctylphosphine, triphenylphosphine, tricyclohexylphosphine, triphenylphosphine/triphenylborane complex, tetraphenylboron tetraphenylphosphine, and the like. Among these, triphenylphosphine is preferred.

Examples of the imidazole compound include 2-phenyl-4-methylimidazole and 1-cyanoethyl-2-phenyltrimellitic acid imidazole.

When the resin composition for an interlayer insulating layer contains an organic curing accelerator, the content thereof is preferably 0.01 to 5 parts by mass, more preferably 0.01 to 3 parts by mass, and still more preferably 0.01 to 2 parts by mass, based on 100 parts by mass of the epoxy resin (a), from the viewpoint of reactivity and storage stability.

< other ingredients >

The resin composition for an interlayer insulating layer may contain components other than the above-described components within a range not to impair the effects of the present invention. Examples of the other components include resin components other than the above components (hereinafter, also referred to as "other resin components"), additives, flame retardants, and the like.

(other resin component)

Examples of other resin components include: a polymer of a bismaleimide compound and a diamine compound, a bismaleimide compound, a diallyl nadiimide (japanese: ビスアリルナジイミド resin), a benzoxazine compound, and the like.

(additives)

Examples of the additives include: thickeners such as ORBEN, bentonite, etc.; adhesion imparting agents such as imidazole-based, thiazole-based, triazole-based, and silane coupling agents; rubber particles; colorants, and the like.

(flame retardant)

Examples of the flame retardant include inorganic flame retardants and resin flame retardants. Examples of the inorganic flame retardant include aluminum hydroxide and magnesium hydroxide. The resin flame retardant may be a halogen-based resin or a non-halogen-based resin, but is preferably a non-halogen-based resin in view of environmental load.

The resin composition for an interlayer insulating layer can be produced by mixing the components (a) to (d), if necessary, the component (e), the component (f), and other components. As the mixing method, a known method may be applied, and for example, mixing using a bead mill or the like may be sufficient.

< thickness of resin film for interlayer insulating layer >

The thickness of the resin film for an interlayer insulating layer can be determined by, for example, the thickness of a conductor layer formed on a printed wiring board. The thickness of the conductor layer is usually 5 to 70 μm, so the thickness of the resin film for the interlayer insulating layer is preferably 1 to 100 μm, and from the viewpoint of making the multilayer printed wiring board thin, it is preferably 1 to 80 μm, more preferably 1 to 70 μm, more preferably 15 to 70 μm, and further preferably 20 to 50 μm.

< support >

The resin film for an interlayer insulating layer of the present invention may be a resin film formed on a support.

Examples of the support include an organic resin film, a metal foil, and release paper. The support is not particularly limited, but an organic resin film is preferable.

Examples of the material of the organic resin film include: polyolefins such as polyethylene and polyvinyl chloride; polyesters such as polyethylene terephthalate (hereinafter, also referred to as "PET") and polyethylene naphthalate; polycarbonate, polyimide, and the like. Among these, PET is preferable from the viewpoint of price and operability.

Examples of the metal foil include copper foil and aluminum foil. When a copper foil is used for the support, a circuit can be formed by using the copper foil as a conductor layer as it is. In this case, as the copper foil, rolled copper, electrolytic copper foil, or the like can be used. The thickness of the copper foil may be, for example, 2 to 36 μm. When a copper foil having a small thickness is used, a copper foil with a carrier can be used from the viewpoint of improving workability.

An embodiment of the present invention includes a multilayer resin film having the resin film for an interlayer insulating layer and the support. As the multilayer resin film, preferred are: the support is a multilayer resin film having an organic resin film thickness of 10 to 70 μm and an interlayer insulating resin film thickness of 1 to 80 μm.

The multilayer resin film may have a layer formed of a resin film for an interlayer insulating layer (resin composition layer for an interlayer insulating layer) and an adhesion auxiliary layer.

These supports and a protective film described later may be subjected to surface treatment such as mold release treatment, plasma treatment, corona treatment, or the like. Examples of the mold release treatment include: and mold release treatment by a silicone resin-based mold release agent, an alkyd resin-based mold release agent, a fluororesin-based mold release agent, or the like.

The thickness of the support is preferably 10 to 120 μm, more preferably 10 to 70 μm, still more preferably 15 to 70 μm, and further preferably 25 to 60 μm from the viewpoint of workability and economy.

The support is usually eventually peeled or removed in the production of a multilayer printed wiring board.

< protective film >

A protective film may be disposed on the surface of the resin film for an interlayer insulating layer of the present invention opposite to the support. The protective film is provided on the surface of the resin film for interlayer insulation layer opposite to the surface on which the support is provided, and is used for the purpose of preventing adhesion and scratching of foreign substances and the like to the resin film for interlayer insulation layer. The protective film is peeled off before the resin film for an interlayer insulating layer is laminated on a circuit board or the like by lamination, hot pressing, or the like.

As the protective film, the same material as the support can be used. The thickness of the protective film can be, for example, 1 to 40 μm.

< method for producing resin film for interlayer insulating layer >

The resin film for an interlayer insulating layer of the present invention can be produced, for example, by coating a resin composition for an interlayer insulating layer on a support and then drying the coating. In this case, the resin composition for an interlayer insulating layer is preferably dissolved and/or dispersed in an organic solvent to form a varnish.

(organic solvent)

Examples of the organic solvent include: ketone solvents such as acetone, methyl ethyl ketone (hereinafter also referred to as "MEK"), methyl isobutyl ketone, and cyclohexanone; acetate-based solvents such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate, and carbitol acetate; carbitol solvents such as cellosolve and butyl carbitol; aromatic hydrocarbon solvents such as toluene and xylene; amide solvents such as dimethylformamide, dimethylacetamide and N-methylpyrrolidone. These may be used alone in 1 kind, or may be used in combination of 2 or more kinds. Among these, ketone solvents are preferable from the viewpoint of solubility, and MEK and methyl isobutyl ketone are more preferable.

As a method for coating the resin composition for an interlayer insulating layer, a method of coating using a known coating apparatus such as a comma coater, a bar coater, a kiss coater, a roll coater, a gravure coater, or a die coater can be applied. The coating apparatus may be selected as appropriate according to the target film thickness.

The drying conditions after the application of the resin composition for an interlayer insulating layer are preferably such that the content of the organic solvent in the obtained resin film for an interlayer insulating layer becomes 10% by mass or less, and more preferably 5% by mass or less.

The drying conditions vary depending on the amount and type of the organic solvent in the varnish, and for example, in the case of a varnish containing 20 to 80 mass% of the organic solvent, the varnish may be dried at 50 to 150 ℃ for 1 to 10 minutes.

[ multilayer printed Wiring Board ]

The multilayer printed wiring board of the present invention is obtained by using at least 1 selected from the resin film for an interlayer insulating layer and the multilayer resin film of the present invention. That is, the resin film for an interlayer insulating layer of the present invention is useful for the application to a multilayer printed wiring board. Further, the resin film for an interlayer insulating layer of the present invention is useful for the formation of a multilayer printed wiring board, particularly a multilayer wiring board.

The multilayer printed wiring board of the present invention can be produced by, for example, including the following steps (1) to (6) [ among them, step (3) is optional. The support may be peeled or removed after the step (1), (2) or (3).

Hereinafter, the term "resin film" refers to both of the "resin film for interlayer insulation layer" and the "multilayer resin film".

(1) A step of laminating the resin film of the present invention on one surface or both surfaces of the circuit board [ hereinafter referred to as a laminating step (1) ].

(2) A step of forming an insulating layer by thermosetting the resin film laminated in the step (1) [ hereinafter, referred to as an insulating layer forming step (2) ].

(3) And (3) a step of forming a hole in the circuit board on which the insulating layer is formed in the step (2) [ hereinafter referred to as a hole forming step (3) ].

(4) A step of removing the smear [ hereinafter referred to as a smear removal step (4) ].

(5) A step of forming a conductor layer on the surface of the insulating layer by plating after the desmear step (4) [ hereinafter referred to as a conductor layer forming step (5) ].

(6) And a step of forming a circuit on the conductor layer by a semi-additive method [ hereinafter referred to as a circuit forming step (6) ].

The laminating step (1) is a step of laminating the resin film of the present invention on one or both surfaces of the circuit board using a vacuum laminator. Examples of the vacuum laminator include: a vacuum coater manufactured by Nichigo-Morton, a vacuum pressure laminator manufactured by Nichigo corporation, a roll dry coater manufactured by Hitachi Kasei Electronics, and a vacuum laminator manufactured by Hitachi Kasei Electronics.

In the case where the resin film is provided with a protective film, after the protective film is peeled off or removed, the resin film for an interlayer insulation layer of the present invention or the resin composition layer for an interlayer insulation layer of the multilayer resin film of the present invention may be laminated on a circuit board by pressure bonding under pressure and heat so as to be in contact with the circuit board.

The lamination can be performed, for example, by preheating the resin film and the circuit board as required, and then pressing the resin film and the circuit board at a pressing temperature of 60 to 140 ℃ and a pressing pressure of 0.1 to 1.1MPa (9.8X 10)⁴～107.9×10⁴N/m²) And an air pressure of 20mmHg (26.7hPa) or less. The lamination method may be a batch method or a continuous method using a roll.

In the insulating layer forming step (2), first, the resin film laminated on the circuit board in the laminating step (1) is cooled to near room temperature.

When the support is peeled off, after the peeling, the resin film laminated on the circuit board is cured by heating to form an insulating layer, that is, an insulating layer to be an "interlayer insulating layer". In the case of using a multilayer resin film containing an adhesion auxiliary layer, the insulating layer formed here is a layer composed of a cured product of the resin composition layer for interlayer insulating layer and a cured product of the adhesion auxiliary layer.

The heat curing may be performed in 2 stages, and examples of conditions include: the 1 st stage is performed at 100-200 ℃ for 5-30 minutes, and the 2 nd stage is performed at 140-220 ℃ for 20-80 minutes. In the case of using a support subjected to a mold release treatment, the support may be peeled off after heat curing.

After the insulating layer is formed by the above-described method, the opening step (3) may be performed as needed. The hole-forming step (3) is: and forming a via hole, a through hole, or the like in the circuit board and the insulating layer by drilling with a drill, a laser, plasma, a combination thereof, or the like. As the laser, a carbon dioxide gas laser, a YAG laser, a UV laser, an excimer laser, or the like can be used.

In the desmear step (4), so-called "desmear" generated when forming via holes, through holes, or the like in the insulating layer and the circuit board is removed by an oxidizing agent. At this time, the surface of the insulating layer may be roughened by an oxidizing agent. That is, the roughening treatment and the removal of the smear may be performed simultaneously.

Examples of the oxidizing agent include: permanganate (potassium permanganate, sodium permanganate, etc.), dichromate, ozone, hydrogen peroxide, sulfuric acid, nitric acid, etc. Among these, an alkaline permanganic acid solution (for example, an aqueous solution of potassium permanganate and sodium hydroxide of sodium permanganate) which is a commonly used oxidizing agent for roughening an insulating layer in the production of a multilayer printed wiring board by a lamination process can be used.

By the roughening treatment, uneven anchoring is formed on the surface of the insulating layer.

In the conductor layer forming step (5), the conductor layer is formed by plating on the surface of the insulating layer on which the uneven anchor is formed by the roughening treatment performed simultaneously in the desmear step (4).

Examples of the plating method include an electroless plating method and an electroplating method. The metal for plating is not particularly limited as long as it is a metal that can be used for plating. The metal for plating may be selected from copper, gold, silver, nickel, platinum, molybdenum, ruthenium, aluminum, tungsten, iron, titanium, chromium, or an alloy containing at least 1 of these metal elements, and is preferably copper or nickel, and more preferably copper.

It should be noted that the following method may also be adopted: a plating resist having a pattern opposite to that of the conductor layer (wiring pattern) is formed in advance, and thereafter, the conductor layer (wiring pattern) is formed only by electroless plating.

After the formation of the conductor layer, annealing treatment may be performed at 150 to 200 ℃ for 20 to 120 minutes. By performing the annealing treatment, the adhesive strength between the interlayer insulating layer and the conductor layer tends to be further improved and stabilized. In addition, the curing of the interlayer insulating layer can be advanced by this annealing treatment.

In the circuit forming step (6), a semi-additive Process (SAP) is used as a method of forming a circuit by patterning the conductor layer. After a resist pattern is formed on the conductor layer (seed layer) formed in the conductor layer forming step (5), plating such as electrolytic copper plating is performed to grow a circuit. Thereafter, the plating resist is removed, and then the seed layer between the circuits is etched to complete the wiring board.

The surface of the conductor layer (circuit) thus fabricated can be roughened (blackening treatment). By roughening the surface of the conductor layer, the adhesion to the resin contacting the conductor layer tends to be improved. For roughening the conductor layer, "CZ-8100", "CZ-8101", "CZ-5480" (all trade names available from MEC) or the like can be used as the organic acid based microetching agent.

Examples of the circuit board used for the multilayer printed wiring board of the present invention include: a substrate having a patterned conductor layer (circuit) formed on one or both surfaces of a substrate such as an epoxy glass, a metal substrate, a polyester substrate, a polyimide substrate, a BT resin substrate, or a thermosetting polyphenylene ether substrate.

A multilayer printed wiring board in which a conductive layer and an insulating layer are alternately formed and which has a patterned conductive layer (circuit) on one surface or both surfaces; a circuit board having an interlayer insulating layer formed of the resin film of the present invention on one or both surfaces of the circuit board and having a conductor layer (circuit) patterned on one or both surfaces thereof; the circuit board of the present invention includes a circuit board and the like in which a conductor layer (circuit) having a pattern is formed on one surface or both surfaces of a cured product formed by bonding and curing the resin films of the present invention.

From the viewpoint of adhesion of the interlayer insulating layer to the circuit board, the surface of the conductor layer of the circuit board may be roughened in advance by blackening or the like as described above.

[ semiconductor Package ]

The semiconductor package of the present invention is obtained by mounting a semiconductor element on the multilayer printed wiring board of the present invention. The semiconductor package of the present invention can be manufactured by mounting a semiconductor element such as a semiconductor chip or a memory at a predetermined position on the multilayer printed wiring board of the present invention. Further, the semiconductor element may be sealed with a sealing resin or the like.

Examples

[a] Next, the invention 1 will be described in further detail by way of examples, but the invention 1 is not limited to these examples.

Example 1

As the epoxy resin, 25.8 parts by mass of "NC-3000-H" (product name, solid content concentration 100 mass%, manufactured by Nippon chemical Co., Ltd.) as a biphenyl novolak type epoxy resin was blended,

as the phenol novolak resin, 6.3 parts by mass of "PAPS-PN 2" (trade name, solid content concentration 100% by mass, Mw/Mn: 1.17, manufactured by Asahi organic materials industries Co., Ltd.) was blended,

as the epoxy resin curing agent, 4.9 parts by mass of "LA-1356-60M" (trade name, solvent: MEK, solid content concentration 60% by mass, manufactured by DIC Co., Ltd.) as a triazine-modified phenol novolak resin was blended,

as the inorganic filler, 92.9 parts by mass of silica (solid content concentration: 70% by mass) prepared by treating the surface of "SO-C2" (trade name, average particle diameter, 0.5 μm, manufactured by Admatechs corporation) with an aminosilane coupling agent and further dispersing the silica in MEK was blended,

as the curing accelerator, 0.026 part by mass of "2E 4 MZ" (trade name, solid content concentration 100% by mass, manufactured by Shikoku Kabushiki Kaisha) which is 2-ethyl-4-methylimidazole was blended,

MEK13.1 parts by mass was added as an additional solvent, and mixing and bead mill dispersion treatment were performed to prepare a resin composition varnish 1 for an adhesive film.

The resin composition varnish 1 for adhesive films obtained above was coated on PET (product name: G2, manufactured by Dinop DuPont film Co., Ltd., film thickness: 50 μm) as a support film, and then dried to form a resin composition layer. The coating thickness was set to 40 μm, and drying was performed so that the residual solvent in the resin composition layer became 8.0 mass%. After drying, a polyethylene film (product name: NF-13, thickness: 25 μm, manufactured by TAMAPOY Co., Ltd.) was laminated on the surface side of the resin composition layer as a protective film. Thereafter, the obtained film was wound into a roll to obtain an adhesive film 1.

Examples 2 to 6 and 8, and comparative examples 1 to 4

Adhesive films 2 to 6 and 8 to 12 were obtained in the same manner as in example 1, except that the raw material composition and the production conditions were changed as shown in table 1 in example 1.

Example 7

A60 μm thick support film 2 was prepared by applying a resin varnish A prepared by the following procedure to a support film made of PET (product name: G2, manufactured by Dipont DuPont film Co., Ltd., film thickness: 50 μm) so as to have a film thickness of 10 μm and drying the coating.

The resin varnish a used above was prepared by the following procedure.

63.9 parts by mass of "NC-3000-H" (product name, solid content concentration 100% by mass, manufactured by Nippon chemical Co., Ltd.) as a biphenyl novolak type epoxy resin was blended as the epoxy resin,

as the epoxy resin curing agent, 18.0 parts by mass of "LA-1356-60M" (trade name, solvent, MEK, solid content concentration 60% by mass, available from DIC Co., Ltd.) as a triazine-modified phenol novolak resin was blended,

15.2 parts by mass of "EXL-2655" (trade name, manufactured by Rohm and Haas electronic materials Co., Ltd.) as core-shell rubber particles were blended,

as the inorganic filler, 8.8 parts by mass of "Aerosil R972" (product name, average particle diameter, 0.02 μm, solid content concentration 100% by mass, manufactured by Nippon Aerosil Co., Ltd.) as fumed silica was blended,

as the curing accelerator, 1.28 parts by mass of "2E 4 MZ" (trade name, solid content concentration 100% by mass, manufactured by Shikoku Kabushiki Kaisha) which is 2-ethyl-4-methylimidazole was added,

226.1 parts by mass of cyclohexanone was added as an additional solvent, and mixing and bead mill dispersion treatment were performed to prepare resin varnish a.

The resin varnish A thus obtained was coated on a support film made of PET (product name: G2, manufactured by Ditupont thin film Co., Ltd., film thickness: 50 μm) so as to have a film thickness of 10 μm, and then dried to obtain a support film 2 having a film thickness of 60 μm.

Next, a varnish of a resin composition for an adhesive film to be applied to the support film 2 obtained above was prepared in the same manner as in example 1 under the raw material composition and the production conditions shown in table 1.

Using the support film 2 and the varnish of the resin composition for adhesive film, an adhesive film 7 was obtained in the same manner as in example 1.

[ evaluation method ]

The obtained adhesive films 1 to 12 were evaluated by the following method.

(method for preparing sample for testing handling Property of adhesive film and method for testing the same)

The obtained adhesive films 1 to 12 were cut into a size of 500mm × 500mm, and samples 1 to 12 for handling test of the adhesive films were prepared.

The workability was evaluated by the following methods (1) to (3) using the samples 1 to 12 for workability test of the produced adhesive film, and the defective one in any test was regarded as "poor workability", and the one without non-defective in any test was regarded as "good workability".

(1) For samples 1 to 12 for the operability test of the adhesive film, the protective film was peeled off first. When the protective film was peeled off, the sample in which a part of the resin after coating and drying adhered to the protective film side or the sample in which powder falling occurred was regarded as poor in handling.

(2) The handling property was poor when the resin after coating and drying was broken by holding 2 points at the center of the film (2 points at the ends so as to be 500mm × 250 mm).

(3) "MCL-E-679 FG (R)" (manufactured by Hitachi Kasei Co., Ltd., copper foil thickness of 12 μm and plate thickness of 0.41mm) as a copper-clad laminate having a surface on which copper foil was subjected to blackening and reduction treatment was laminated by using a batch type vacuum pressure laminator "MVL-500" (manufactured by Kasei Co., Ltd., trade name) to laminate. The degree of vacuum at this time was 30mmHg or less, the temperature was 90 ℃ and the pressure was 0.5 MPa. After cooling to room temperature, the support film was peeled (in the adhesive film 7, the PET and the resin layer formed thereon were peeled off from the support film 2). In this case, the material in which powder falling or PET cracking occurred in the middle was regarded as poor in handling properties.

(method of preparing and testing sample for measuring thermal expansion coefficient)

The adhesive films 1 to 12 thus obtained were cut into 200mm × 200mm pieces, and the protective film was peeled off, and laminated on a copper foil 18 μm thick by using a batch vacuum pressure laminator "MVL-500" (manufactured by kokai corporation, trade name). The degree of vacuum at this time was 30mmHg or less, the temperature was 90 ℃ and the pressure was 0.5 MPa.

After cooling to room temperature, the support film (in the case of the adhesive film 7, the PET and the resin layer formed thereon were peeled off from the support film 2) was peeled off, and cured in a dryer at 180 ℃ for 120 minutes. Thereafter, the copper foil was removed with an iron chloride solution, and materials having a cut width of 3mm and a length of 8mm were used as samples 1 to 12 for measuring thermal expansion coefficient.

The thermal expansion coefficients were measured by the following methods using the prepared samples 1 to 12 for thermal expansion coefficient measurement.

The obtained samples 1 to 12 for measuring thermal expansion coefficient were subjected to a thermal mechanical analyzer manufactured by Seiko Instruments to obtain a change curve of expansion amount at a temperature rise rate of 10 ℃/min to 240 ℃, after cooling to-10 ℃, and then at a temperature rise rate of 10 ℃/min to 300 ℃, and an average thermal expansion coefficient of 0 to 150 ℃ of the change curve of expansion amount was obtained.

(method of manufacturing and testing embedding evaluation substrate)

The inner layer circuit used for the embedding evaluation substrate is as follows. Through holes having a diameter of 0.15mm were formed by a drill punching method in such a manner that 25 pieces by 25 pieces were formed at intervals of 5mm on "MCL-E-679 FG (R)" (trade name, manufactured by Hitachi chemical Co., Ltd.) which is a copper-clad laminated plate having a copper foil thickness of 12 μm and a plate thickness of 0.15mm (including a copper foil thickness). Next, desmearing and electroless plating are performed, and electroplating is performed in the through hole by electroplating.

As a result, a circuit board having a plate thickness of 0.2mm including a copper thickness and 25X 25 through holes having a diameter of 0.1mm and a pitch of 5mm was obtained.

Next, the adhesive films 1 to 12 from which the protective film was peeled were arranged so that the resin composition layer was opposed to the circuit surface side of the circuit board, and then laminated by lamination using a batch type vacuum laminator "MVL-500" (manufactured by kokai corporation, trade name). The degree of vacuum at this time was 30mmHg, the temperature was 90 ℃ and the pressure was 0.5 MPa.

After cooling to room temperature, the circuit board having a through-hole with adhesive films on both surfaces was sandwiched between 2 sheets of 1mm thick aluminum plates, and laminated using the vacuum laminator described above. The degree of vacuum at this time was 30mmHg, the temperature was 90 ℃ and the pressure was 0.7 MPa.

After cooling to room temperature, the support film (in the case of the adhesive film 7, the PET and the resin layer formed thereon were peeled off from the support film 2) was peeled off, and cured in a dryer at 180 ℃ for 120 minutes. Thus, embedding evaluation substrates 1 to 12 were obtained.

The substrates 1 to 12 were evaluated for embeddability by the following method.

The difference in level of the surface of the through-hole portion of each of the substrates 1 to 12 was evaluated for embeddability by using a contact surface roughness meter "SV 2100" (trade name) manufactured by MITUTOYO. The height difference was measured in such a manner that the central portion of the surface of the through-hole was taken in 10, and the average value of 10 depressions was calculated.

[ Table 1]

The ingredients for table 1 are shown below.

[ epoxy resin ]

■ NC-3000-H: biphenyl novolac epoxy resin (product name, solid content concentration 100% by mass, manufactured by Nippon Kabushiki Kaisha)

■ N-673-80M: cresol novolac epoxy resin (trade name, solvent, manufactured by DIC corporation; MEK, solid content concentration 80 mass%)

[ Novolac type phenol resin ]

■ PAPS-PN 2: phenol novolak resin (trade name, 100% solid content concentration, Mw/Mn ═ 1.17, manufactured by Asahi organic materials industries Co., Ltd.)

■ PAPS-PN 3: phenol novolak resin (trade name, 100% solid content concentration, Mw/Mn ═ 1.50, manufactured by Asahi organic materials industries Co., Ltd.)

■ HP-850: novolac phenol resin produced using hydrochloric acid instead of phosphoric acid (trade name, solid content concentration 100% by mass, manufactured by Hitachi chemical Co., Ltd.)

[ triazine-modified phenol novolak resin ]

■ LA-1356-60M: triazine-modified phenol novolak resin (trade name, solvent, available from DIC K., MEK, solid content concentration: 60% by mass)

[ inorganic Filler ]

■ SO-C2: silica "SO-C2" (trade name, average particle diameter; 0.5 μm) manufactured by Admatechs, Inc. was treated with an aminosilane coupling agent on the surface thereof, and further dispersed in an MEK solvent (solid content concentration: 70 mass%)

■ SO-C6: silica "SO-C6" (trade name, average particle diameter; 2.2 μm) manufactured by Admatechs, Inc. was treated with an aminosilane coupling agent on the surface thereof, and further dispersed in an MEK solvent (solid content concentration: 70 mass%)

■ Aerosil R972: fumed silica (trade name, manufactured by Nippon Aerosil Co., Ltd., solid content 100 mass%, specific surface area 100 m)²/g)

[ curing accelerators ]

■ 2E4 MZ: 2-Ethyl-4-methylimidazole (trade name, solid content concentration 100% by mass, product of Siguo Kasei Kogyo Co., Ltd.)

As is clear from table 1, the adhesive film of the present invention has good handling properties, and an interlayer insulating layer having a low thermal expansion coefficient and excellent embeddability can be obtained from the adhesive film of the present invention.

On the other hand, when the adhesive film of the present invention is not used, any of workability, thermal expansion coefficient and embeddability is poor.

Namely, it can be seen that: according to the invention 1, an adhesive film having a low thermal expansion coefficient, excellent embeddability, and excellent handleability can be provided, and an interlayer insulating layer having a low thermal expansion coefficient after curing can be provided.

[b] Next, the invention 2 will be described in further detail, but the invention 2 is not limited to these examples.

[ production of resin film for interlayer insulating layer ]

Examples 1 to 9 and comparative examples 1 to 4

The compounding composition shown in tables 2 to 4 [ the numerical values in the tables are parts by mass of the solid content, and the amounts are converted to the solid content in the case of a solution (excluding an organic solvent) or a dispersion. Mixing and stirring the components. Thereafter, the dispersion was carried out by bead mill treatment to obtain a varnish-like resin composition for an interlayer insulation layer.

The resin composition for an interlayer insulation layer obtained above was coated on a 38 μm thick PET film as a support using a die coater, and dried at 100 ℃ for 1.5 minutes to obtain a multilayer resin film having a resin film for an interlayer insulation layer with a film thickness of 40 μm, and each evaluation was performed according to the following method. The results are shown in tables 2 to 4.

[ (1) evaluation of insulation reliability ]

The insulation reliability was evaluated by a high temperature and high humidity bias test. The multilayer resin films having a thickness of 40 μm obtained in each example were bonded to a comb-shaped copper electrode of an evaluation device teg (test Element group) (trade name: WALTS-KIT EM0101JY, manufactured by WALTS, L/S: 10 μm/10 μm) at 110 ℃. Thereafter, the PET film as a support was peeled off, heated in an oven at 190 ℃ for 2 hours, and cooled to room temperature to obtain a sample for measurement.

To the electrode portion of the TEG of the obtained measurement sample, a lead wire was attached with solder, and a high temperature and high humidity bias test [ voltage; 5V (direct current), test time; 200 hours, 130 ℃, 85% RH (using high temperature and high humidity machine (ESPEC corporation)) ].

When the resistance value is kept at 1.0X 10 in the test time of 200 hours⁷Ω or more, the insulation reliability is excellent.

[ (2) evaluation of operability ]

The multilayer resin films obtained in the respective examples were left to stand at room temperature (25 ℃) for 5 days, and then, in a state where the resin film for interlayer insulation layer was provided on the support, the multilayer resin films were bent 180 ° with the resin film for interlayer insulation layer side being the outer side (the PET film side being the inner side), and the presence or absence of cracking was visually confirmed. Similarly, 20 sheets of the multilayer resin films were confirmed and expressed in terms of "the number of the multilayer resin films in which cracks occurred/20".

[ (3) measurement of glass transition temperature (Tg) (evaluation of Heat resistance) ], a method for producing the same

The glass transition temperature (Tg) was determined by peeling the support from the multilayer resin film obtained in each example to form only the resin film for an interlayer insulation layer, and heat curing a laminate obtained by laminating 5 sheets of the resin films at 190 ℃ for 120 minutes to obtain a cured product.

The cured product was cut out to have a length of 40mm (X direction), a width of 4mm (Y direction) and a thickness of 200 μm (Z direction) as an evaluation substrate, and thermo-mechanical analysis was performed on the evaluation substrate by a compression method using a thermo-mechanical analyzer (Q400, manufactured by TA Instrument Co., Ltd.). Specifically, the evaluation substrate was mounted on the apparatus in the stretching direction (x-y direction), and then measured twice in succession under the measurement conditions of a load of 5mg and a temperature rise rate of 10 ℃/min, and the Tg indicated by the intersection point of the different tangent lines of the thermal expansion curve in the second measurement was obtained as an index of heat resistance.

[ Table 2]

TABLE 2

1 represents the total number of functional groups of (b) curing agent relative to the total number of functional groups of (a) epoxy resin.

2 represents the content of hindered phenol-based compounds or non-hindered phenol-based compounds.

[ Table 3]

TABLE 3

1 represents the total number of functional groups of (b) curing agent relative to the total number of functional groups of (a) epoxy resin.

[ Table 4]

TABLE 4

1 represents the total number of functional groups of (b) curing agent relative to the total number of functional groups of (a) epoxy resin.

The components described in tables 2 to 4 are shown below.

[ (a) epoxy resin ]

■ N-673: cresol novolac type epoxy resin ("EPICLON (registered trademark) N-673", available from DIC corporation, having a solid content of 100% by mass and an epoxy equivalent of 210g/eq)

■ jER157S 70: bisphenol A novolac epoxy resin (Mitsubishi chemical corporation, epoxy equivalent: 210g/eq, solid content concentration 100% by mass)

■ NC-3000-H: aralkyl novolac type epoxy resin having biphenyl skeleton (made by Nippon Kabushiki Kaisha, solid content 100% by mass, epoxy equivalent: 289g/eq)

■ jER 828: bisphenol A type liquid epoxy resin (Mitsubishi chemical corporation, solid content 100% by mass, epoxy equivalent: 185g/eq)

[ (b) curing agent ]

■ BA 230S: bisphenol A cyanate ester resin prepolymer ("Primaset BA 230S" manufactured by Lonza corporation) and (b2)

■ HPC-8000-65T: an active ester resin (EPICLON (registered trademark) HPC-8000-65T manufactured by DIC corporation, a solid content of 65 mass%, a norbenzene product), and (b1)

■ LA-7054: triazine-containing phenol novolac resin ("phenol (registered trademark) LA-7054", manufactured by DIC corporation) and (b3)

■ PAPS-PN 2: triazine-containing phenol novolac resin (produced by Asahi organic materials Co., Ltd., 100 mass% solid content, Mw/Mn 1.17, b3) component

■ LA 3018-50P: cresol novolak resin containing triazine (product of DIC corporation, "phenol (registered trademark) LA 3018-50P"), (b3) component

(other curing agents)

■ HCA-HQ-HS: phosphorus-containing phenol Compound (manufactured by Sanko Co., Ltd.), 10- (2, 5-dihydroxyphenyl) -9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide

[ (c) inorganic Filler Material ]

■ SO-C2: spherical silica treated with aminosilane coupling agent (manufactured by Admatechs Co., Ltd., volume average particle diameter of 0.5 μm, solid content concentration of 100% by mass)

[ (d) (d') hindered phenol-based Compound ]

■ Yoshinox BB: 4, 4' -Butylenebis- (6-tert-butyl-3-methylphenol) (product of Mitsubishi chemical corporation)

■ BHT: 2, 6-Di-tert-butyl-p-cresol (manufactured by Tokyo Kasei Co., Ltd.)

■ Yoshinox 425: 2, 2' -methylenebis- (4-ethyl-6-tert-butylphenol) (manufactured by Mitsubishi chemical corporation)

(non-hindered phenol compound)

■ bisphenol A: manufactured by Tokyo chemical industry Co Ltd

[ (e) phenoxy resin ]

■ YX7200B 35: phenoxy resin (JER (registered trademark) YX7200B35, manufactured by Mitsubishi chemical corporation, epoxy equivalent: 3,000 to 16,000g/eq, 35 mass% solid content, MEK removed)

[ (f) curing Accelerator ]

■ TPP: triphenylphosphine (manufactured by KANTO CHEMICAL CO., LTD.) organic curing accelerator

■ Zinc naphthenate: (8% by mass of solid content concentration of Petroleum Fine solution, manufactured by Wako pure chemical industries, Ltd.), Metal-based solidification promoter

■ 2 PZ-CNS-PW: 1-cyanoethyl-2-phenyltrimellitic acid imidazole (product of Shikoku Kabushiki Kaisha)

[ additional organic solvent ]

■ Cyclohexanone: GODO product of Kabushiki Kaisha

As is clear from tables 2 to 4, the resin films for interlayer insulation layers of examples 1 to 9 were high in heat resistance and insulation reliability and also excellent in handling property.

On the other hand, the resin films for interlayer insulation layers obtained in comparative examples 1 to 4 had poor insulation reliability and workability, and thus they could not be compatible with each other.

Claims (23)

1. A resin film for an interlayer insulating layer, which is formed using a thermosetting resin composition containing (a) an epoxy resin, (b) a curing agent, (c) an inorganic filler, (d) an antioxidant and (e) a phenoxy resin,

the curing agent (b) comprises at least 1 selected from active ester curing agent (b1), cyanate ester curing agent (b2) and phenol novolac curing agent (b3) containing triazine ring, the antioxidant (d) is hindered phenol antioxidant, and the phenoxy resin (e) is phenoxy resin containing more than 1 selected from terpene structure and trimethylcyclohexane structure.

2. The resin film for an interlayer insulation layer according to claim 1, wherein the hindered phenol-based antioxidant comprises at least 1 selected from a compound having a group represented by the following general formula (dI) and a compound represented by the following general formula (dII),

in the formula (dI), R^d1、R^d2And R^d3Each independently represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms; wherein R is^d1And R^d2At least 1 of them represents an alkyl group having 1 to 8 carbon atoms;

in the formula (dII), R^d4And R^d5Each independently represents an alkyl group having 1 to 8 carbon atoms; r^d6、R^d7And R^d8Each independently represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms; wherein R is^d6、R^d7And R^d8At least 1 of them represents an alkyl group having 1 to 8 carbon atoms.

3. The resin film for an interlayer insulation layer according to claim 2, wherein the compound having a group represented by the general formula (dI) is a compound represented by any one of the following general formulae (dI-1) to (dI-3),

in the formulae (dI-1) and (dI-2), R^d11、R^d12、R^d13、R^d21、R^d22And R^d23Each independently represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms; wherein R is^d11And R^d12At least 1 of (1), and R^d21And R^d22At least 1 of them represents an alkyl group having 1 to 8 carbon atoms; x¹And X²Each independently represents an organic group having a valence of 1 to 3; n is¹And n²Each independently is an integer of 1 to 3;

in the formula (dI-3), R^d31And R^d32Each independently represents an alkyl group having 1 to 8 carbon atoms; y represents-COOCH₂－、－COOCH₂CH₂－。

4. The resin film for an interlayer insulation layer according to claim 3, wherein the hindered phenol antioxidant is at least 1 selected from the group consisting of the compound represented by the general formula (dI-1) and the compound represented by the general formula (dI-2), and has a molecular weight of 1500 or less.

5. A resin film for an interlayer insulation layer, which comprises (a) an epoxy resin, (b) a curing agent, (c) an inorganic filler, (d') at least 1 selected from a compound having a group represented by the following general formula (dI) and a compound represented by the following general formula (dII), and (e) a phenoxy resin,

the curing agent (b) comprises at least 1 selected from (b1) active ester curing agent, (b2) cyanate ester curing agent and (b3) phenol novolac curing agent containing triazine ring, the phenoxy resin (e) is phenoxy resin containing more than 1 selected from terpene structure and trimethylcyclohexane structure,

in the formula (dI), R^d1、R^d2And R^d3Each independently represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms; wherein R is^d1And R^d2At least 1 of them represents an alkyl group having 1 to 8 carbon atoms;

in the formula (dII), R^d4And R^d5Each independently represents an alkyl group having 1 to 8 carbon atoms; r^d6、R^d7And R^d8Each independently represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms; wherein R is^d6、R^d7And R^d8At least 1 of them represents an alkyl group having 1 to 8 carbon atoms.

6. The resin film for an interlayer insulation layer according to claim 5, wherein the compound having a group represented by the general formula (dI) is a compound represented by any one of the following general formulae (dI-1) to (dI-3),

in the formulae (dI-1) and (dI-2), R^d11、R^d12、R^d13、R^d21、R^d22And R^d23Each independently represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms; wherein R is^d11And R^d12At least 1 of (1), and R^d21And R^d22At least 1 of them represents an alkyl group having 1 to 8 carbon atoms; x¹And X²Each independently represents an organic group having a valence of 1 to 3; n is¹And n²Each independently is an integer of 1 to 3;

in the formula (dI-3), R^d31And R^d32Each independently represents an alkyl group having 1 to 8 carbon atoms; y represents-COOCH₂－、－COOCH₂CH₂－。

7. The resin film for an interlayer insulation layer according to claim 6, wherein the compound having a group represented by the general formula (dI) is at least 1 selected from the group consisting of the compound represented by the general formula (dI-1) and the compound represented by the general formula (dI-2), and has a molecular weight of 1500 or less.

8. The resin film for an interlayer insulating layer according to claim 1 or 5, wherein the ratio of the total number of functional groups of the curing agent (b) to the total number of epoxy groups of the epoxy resin (a), i.e., the total number of functional groups of the curing agent (b)/the total number of epoxy groups of the epoxy resin (a), is 0.2 to 2.

9. The resin film for an interlayer insulation layer according to claim 1 or 5, wherein the (a) epoxy resin has at least 1 selected from a bisphenol A type epoxy resin, a naphthalene type epoxy resin, an aralkyl novolac type epoxy resin having a biphenyl skeleton, and a cresol novolac type epoxy resin.

10. The resin film for an interlayer insulation layer according to claim 1 or 5, wherein the (b) curing agent comprises (b1) an active ester-based curing agent.

11. The resin film for an interlayer insulation layer according to claim 1 or 5, wherein the (b) curing agent comprises (b1) an active ester-based curing agent and (b3) a triazine ring-containing phenol novolac-based curing agent.

12. The resin film for an interlayer insulation layer according to claim 1 or 5, wherein the (b3) triazine ring-containing phenol novolac-based curing agent comprises at least one of a triazine ring-containing phenol novolac resin and a triazine ring-containing cresol novolac resin.

13. The resin film for an interlayer insulation layer according to claim 1 or 5, wherein the content of the (c) inorganic filler is 30 to 90% by mass based on the solid content of the thermosetting resin composition.

14. The resin film for an interlayer insulation layer according to claim 1 or 5, wherein the (c) inorganic filler comprises at least 1 selected from spherical silica and fused silica, and has a volume average particle diameter of 0.01 to 5 μm.

15. The resin film for an interlayer insulating layer according to claim 1 or 5, wherein the antioxidant (d) comprises 2, 6-di-tert-butyl-p-cresol, 4 ' -butylidenebis- (6-tert-butyl-3-methylphenol), 2 ' -methylenebis- (4-methyl-6-tert-butylphenol), 2 ' -methylenebis- (4-ethyl-6-tert-butylphenol), 2, 6-di-tert-butyl-4-ethylphenol, 1, 3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, n-octadecyl-3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate, pentaerythrityl-tetrakis [ 3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ], triethylene glycol bis [ 3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionate ], Tris (3, 5-di-tert-butyl-4-hydroxybenzyl) isocyanurate, 1, 6-hexanediol-bis [ 3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ], 2, 4-bis- (N-octylthio) -6- (4-hydroxy-3, 5-di-tert-butylanilino) -1, 3, 5-triazine, 2-thio-diethylene bis [ 3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ], N' -hexamethylenebis [ 3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionamide ], 1,3, 5-trimethyl-2, 4, 6-tris (3, 5-di-tert-butyl-4-hydroxybenzyl) benzene, calcium bis (ethyl 3, 5-di-tert-butyl-4-hydroxybenzylphosphonate), 2, 4-bis [ (octylthio) methyl ] o-cresol or isooctyl-3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate.

16. The resin film for an interlayer insulation layer according to claim 1 or 5, wherein the (e) phenoxy resin has an alicyclic structure.

17. The resin film for an interlayer insulation layer according to claim 1 or 5, which is used for a multilayer printed wiring board.

18. The resin film for an interlayer insulation layer according to claim 1 or 5, which is used for forming a build-up layer of a multilayer printed wiring board.

19. A multilayer resin film comprising the resin film for an interlayer insulation layer according to any one of claims 1 to 16 and a support.

20. The multilayer resin film according to claim 19, wherein the support is an organic resin film having a thickness of 10 to 70 μm, and the resin film for an interlayer insulating layer has a thickness of 1 to 80 μm.

21. A multilayer printed wiring board obtained by using at least 1 selected from the resin film for an interlayer insulation layer according to any one of claims 1 to 16 and the multilayer resin film according to claim 19 or 20.

22. A semiconductor package comprising a semiconductor element mounted on the multilayer printed wiring board according to claim 21.

23. A method for producing a multilayer printed wiring board using the resin film for an interlayer insulating layer according to any one of claims 1 to 16 and the multilayer resin film according to claim 19 or 20, comprising the steps of:

(1) laminating the resin film for an interlayer insulating layer and the multilayer resin film on one surface or both surfaces of a circuit board;

(2) a step of forming an insulating layer by thermally curing the resin film laminated in the step (1);

(3) a step of forming a hole in the circuit board on which the insulating layer is formed in the step (2);

(4) removing the drilling dirt;

(5) forming a conductor layer by plating on the surface of the insulating layer obtained in the step (4);

(6) and forming a circuit on the conductor layer by a semi-additive method.