JP2007051226A - Resin composition with low dielectric constant - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a curable resin composition with high dielectric constants imparting a cured product with low dielectric dissipation factor and excellent in bonding strength with a conductor. <P>SOLUTION: The invention relates to the curable resin composition comprising (A) a curable polyvinyl benzyl ether compound, (B) a modified styrene based elastomer having one or more functional groups selected from a hydroxyl group, a carboxyl group, an amino group and an acid anhydride group. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a curable resin composition useful for use in electronic parts such as multilayer printed wiring boards, particularly electronic parts used in a high frequency region. In addition, the present invention provides an adhesive film, an adhesive film with a copper foil, a prepreg, a printed wiring board in which an insulating layer is composed of a cured product of the curable resin composition, and the like prepared using the curable resin composition Also related to electronic components.

  In recent years, computers and information communication devices have become increasingly high-performance and highly functional, and in order to process a large amount of data at high speed, the signals handled tend to be high-frequency. In particular, the frequency range of radio waves used for mobile phones and satellite broadcasts is in the high frequency range of the GHz band, and as an organic insulating material used for high dielectric capacitance materials to suppress transmission loss due to higher frequencies. A material having a low relative dielectric constant and dielectric loss tangent is desired.

  As a compound useful for an organic insulating material having excellent characteristics as described above, for example, Patent Document 1 is known for the polyvinyl benzyl ether compound of the present application.

  Cured products of these compounds have a low dielectric loss tangent, high heat resistance, and low water absorption, and are useful for the above organic insulating materials, and are necessary when used as high dielectric materials for printed wiring boards and electronic components. Patent Document 2 describes the adhesion to a copper foil. According to this, a curable polyvinyl benzyl ether resin composition containing a polyvinyl benzyl ether compound and a styrenic elastomer is disclosed, and the cured product of the composition does not significantly impair the physical properties of the polyvinyl benzyl ether compound. It has been reported that flexibility is imparted and adhesion to copper foil is improved.

However, in the cured product of the composition, the adhesion with the copper foil was not sufficient. Further, formation of a conductor layer by plating has not been studied at all.
Japanese Patent Laid-Open No. 09-31006 JP 2002-128977 A

  An object of the present invention is to provide a resin composition having a low relative dielectric constant and dielectric loss tangent of a cured product and excellent adhesion strength to a conductor, and further an adhesive film using the curable resin composition Another object is to provide an adhesive film and a prepreg with copper foil, an electronic component such as a printed wiring board using the adhesive film and the like, and a method for producing the same.

  In order to solve the above-mentioned problems, the present inventors have intensively studied, and as a result, selected from the group consisting of (A) a curable polyvinyl benzyl ether compound and (B) a hydroxyl group, a carboxyl group, an amino group, and an acid anhydride group. The cured product of the curable resin composition containing one or more modified styrene elastomers having one or more functional groups has excellent adhesion to the copper foil, and the surface of the cured product is roughened to form a conductor layer by plating. In this case, the present inventors have found that a conductor layer having excellent adhesion strength can be obtained and completed the present invention.

［式（１）中、Ｒ^１はメチル基またはエチル基、Ｒ^２は水素原子または１〜１０の炭化水素基、Ｒ^３水素原子またはビニルベンジル基（但し、水素原子とビニルベンジル基のモル比は６０：４０〜０：１００の範囲である）、ｎは２〜４の整数を表す。］
で表される硬化性ポリビニルベンジルエーテル化合物である、上記［１］記載の硬化性樹脂組成物。
［３］ （Ｂ）変性スチレン系エラストマーの官能基がカルボキシル基および酸無水物基からなる群より選択される１種以上である、上記［１］または上記［２］記載の硬化性樹脂組成物。
［４］ 成分（Ａ）と成分（Ｂ）の質量比が９７：３〜５０：５０である、上記［１］〜［３］いずれかに記載の硬化性樹脂組成物。
［５］ 上記［１］〜［４］いずれかに記載の硬化性樹脂組成物が支持フィルム上に層形成された接着フィルム。
［６］ 上記［１］〜［４］いずれかに記載の硬化性樹脂組成物が銅箔上に層形成された銅箔付き接着フィルム。
［７］ 上記［１］〜［４］いずれかに記載の硬化性樹脂組成物がシート状繊維基材に含浸されているプリプレグ。
［８］ 以下の工程（１）〜（７）を含む多層プリント配線板の製造方法：
（１）上記［５］記載の接着フィルムを回路基板にラミネートする工程、
（２）支持フィルムを剥離するか、または剥離しない工程、
（３）硬化性樹脂組成物を熱硬化する工程、
（４）支持フィルムが存在する場合に該支持フィルムを剥離する工程、
（５）硬化物表面を、アルカリ性酸化剤水溶液で粗化する工程、
（６）粗化された硬化物表面にメッキにより導体層を形成する工程、および
（７）導体層に回路形成する工程。
［９］ 以下の工程（１）〜（６）を含む多層プリント配線板の製造方法：
（１）上記［６］記載の銅箔付き接着フィルムを回路基板にラミネートする工程、
（２）硬化性樹脂組成物を熱硬化する工程、
（３）銅箔を溶解除去する工程、
（４）硬化物表面を、アルカリ性酸化剤水溶液で粗化する工程、
（５）粗化された硬化物表面にメッキにより導体層を形成する工程、および
（６）導体層に回路形成する工程。
［１０］ 以下の工程（１）〜（３）を含む多層プリント配線板の製造方法：
（１）上記［６］記載の銅箔付き接着フィルムを回路基板にラミネートする工程、
（２）硬化性樹脂組成物を熱硬化する工程、および
（３）銅箔層に回路形成する工程。
［１１］ 以下の工程（１）〜（５）を含む多層プリント配線板の製造方法：
（１）上記［７］記載のプリプレグを回路基板にラミネートする工程、
（２）硬化性樹脂組成物を熱硬化する工程、
（３）硬化物表面を、アルカリ性酸化剤水溶液で粗化する工程、
（４）粗化された硬化物表面にメッキにより導体層を形成する工程、および
（５）導体層に回路形成する工程。
［１２］ 上記［１］〜［４］いずれか１項に記載の硬化性樹脂組成物の硬化物により絶縁層の一部または全部が形成されている多層プリント配線板。
［１３］ 上記［１］〜［４］いずれか１項に記載の硬化性樹脂組成物の硬化物により絶縁層の一部または全部が形成されている電子部品。
［１４］ 上記［７］に記載のプリプレグの硬化物により絶縁層の一部または全部が形成されている多層プリント配線板。
［１５］ 上記［１１］に記載のプリプレグの硬化物により絶縁層の一部または全部が形成されている電子部品。 That is, the present invention includes the following contents.
[1] (A) Modified styrenic elastomer having one or more functional groups selected from the group consisting of (A) curable polyvinyl benzyl ether compound, (B) hydroxyl group, carboxyl group, amino group and acid anhydride group And (C) a curable resin composition containing a dielectric powder.
[2] (A) The curable polyvinyl benzyl ether compound has the following formula (1):

[In the formula (1), R ¹ is a methyl group or an ethyl group, R ² is a hydrogen atom or a hydrocarbon group of 1 to 10, a R ³ hydrogen atom or a vinylbenzyl group (provided that the molar ratio of a hydrogen atom to a vinylbenzyl group) Is in the range of 60:40 to 0: 100), and n represents an integer of 2 to 4. ]
The curable resin composition according to the above [1], which is a curable polyvinyl benzyl ether compound represented by the formula:
[3] The curable resin composition according to [1] or [2] above, wherein the functional group of the (B) modified styrene elastomer is at least one selected from the group consisting of a carboxyl group and an acid anhydride group. .
[4] Curable resin composition in any one of said [1]-[3] whose mass ratio of a component (A) and a component (B) is 97: 3-50: 50.
[5] An adhesive film in which the curable resin composition according to any one of [1] to [4] is layered on a support film.
[6] An adhesive film with a copper foil in which the curable resin composition according to any one of [1] to [4] is layered on a copper foil.
[7] A prepreg in which a sheet-like fiber base material is impregnated with the curable resin composition according to any one of [1] to [4].
[8] A method for producing a multilayer printed wiring board including the following steps (1) to (7):
(1) A step of laminating the adhesive film according to the above [5] on a circuit board,
(2) A step of peeling or not peeling the support film,
(3) a step of thermosetting the curable resin composition;
(4) a step of peeling the support film when the support film is present;
(5) A step of roughening the surface of the cured product with an aqueous alkaline oxidant solution,
(6) A step of forming a conductor layer on the roughened cured product surface by plating, and (7) a step of forming a circuit on the conductor layer.
[9] A method for producing a multilayer printed wiring board including the following steps (1) to (6):
(1) A step of laminating the adhesive film with a copper foil according to the above [6] on a circuit board,
(2) a step of thermosetting the curable resin composition;
(3) a step of dissolving and removing the copper foil,
(4) A step of roughening the surface of the cured product with an aqueous alkaline oxidant solution,
(5) A step of forming a conductor layer on the roughened cured product surface by plating, and (6) a step of forming a circuit on the conductor layer.
[10] A method for producing a multilayer printed wiring board including the following steps (1) to (3):
(1) A step of laminating the adhesive film with a copper foil according to the above [6] on a circuit board,
(2) a step of thermosetting the curable resin composition, and (3) a step of forming a circuit on the copper foil layer.
[11] A method for producing a multilayer printed wiring board comprising the following steps (1) to (5):
(1) A step of laminating the prepreg described in [7] above on a circuit board,
(2) a step of thermosetting the curable resin composition;
(3) a step of roughening the surface of the cured product with an aqueous alkaline oxidant solution;
(4) A step of forming a conductor layer on the roughened cured product surface by plating, and (5) a step of forming a circuit on the conductor layer.
[12] A multilayer printed wiring board in which a part or all of the insulating layer is formed of a cured product of the curable resin composition according to any one of [1] to [4].
[13] An electronic component in which a part or all of the insulating layer is formed of a cured product of the curable resin composition according to any one of [1] to [4].
[14] A multilayer printed wiring board in which a part or all of the insulating layer is formed of a cured product of the prepreg according to [7].
[15] An electronic component in which a part or all of the insulating layer is formed of a cured product of the prepreg according to [11].

  The curable resin composition of the present invention has a low dielectric constant, a low dielectric loss tangent, a high heat resistance, a low water absorption, and impairs the characteristics of the curable polyvinyl benzyl ether compound, which is less likely to vary in dielectric properties due to temperature and moisture absorption. In addition, it is possible to provide an electronic component such as a printed wiring board having excellent adhesion strength between the cured product, the copper foil, and the plated conductor layer. Moreover, the curable resin composition of this invention can be processed into a film form, and it can manufacture electronic components, such as a printed wiring board, more efficiently by using with the form of an adhesive film.

  The curable polyvinyl benzyl ether compound in the present invention can be obtained, for example, by reacting a compound (polyphenol compound) having two or more hydroxybenzyl groups in one molecule with vinyl benzyl halide in the presence of an alkali. (See JP-A-9-31006 and JP-A-2001-181383).

    Examples of the polyphenol compound include hydroquinone, bisphenol A, bisphenol F, bisphenol S, biphenol, phenol novolak resin, a condensate of phenol and benzaldehyde, xylok type phenol resin, and the like. The aromatic ring of these compounds may be substituted with an alkyl group, halogen or the like.

  Examples of the vinyl benzyl halide include p-vinyl benzyl chloride, m-vinyl benzyl chloride, and any mixture thereof.

  Typical polyvinyl benzyl ether compounds include those represented by the following formula (1) (see JP-A-9-31006, JP-A-2001-181383, etc.).

式（１）中、Ｒ^１はメチル基またはエチル基、Ｒ^２は水素原子または１〜１０の炭化水素基、Ｒ^３水素原子またはビニルベンジル基（但し、水素原子とビニルベンジル基のモル比は６０：４０〜０：１００の範囲である）、ｎは２〜４の整数を表す。

In the formula (1), R ¹ is a methyl group or an ethyl group, R ² is a hydrogen atom or 1 to 10 hydrocarbon group, R ³ hydrogen atom or vinylbenzyl group (however, the molar ratio of hydrogen atom to vinylbenzyl group is 60: 40-0: 100), n represents an integer of 2-4.

  These polyvinyl benzyl ether compounds can be easily produced according to the descriptions in JP-A-9-31006 and JP-A-2001-181383.

  The products available on the market are Showa Polymer Co., Ltd. V-1000X (Tg 160 ° C. of cured product, relative dielectric constant 2.7, dielectric loss tangent 0.0045), V-1100X (Tg 171 ° C. of cured product, ratio) Dielectric constant 2.56, dielectric loss tangent 0.0038) and the like.

  Two or more different types of polyvinyl benzyl ether compounds may be mixed and used.

  In the present invention, “modified styrene elastomer having one or more functional groups selected from the group consisting of hydroxyl group, carboxyl group, amino group and acid anhydride group” (hereinafter abbreviated as modified styrene elastomer). May have one or more functional groups such as hydroxyl groups in the molecular chain of a copolymer of a thermoplastic elastomer such as butadiene, isoprene, ethylene, butylene, and propylene and styrene.

  The modified styrene elastomer in the present invention is, for example, one or more selected from the group consisting of a hydroxyl group, an amino group, a carboxyl group, and an acid anhydride group at the living end of the styrene elastomer using an organolithium compound as a polymerization catalyst. A method of adding a modifier having one or more functional groups of the above, or reacting an organic alkali metal compound such as an organolithium compound with a styrene elastomer having no living terminal, and adding the organic alkali metal to the styrene elastomer Examples thereof include a method in which a modifying agent having a predetermined functional group is subjected to an addition reaction (see, for example, JP-A-2004-59741). When the modifying agent is allowed to react with the living end of the styrene elastomer, it is not necessary that all living ends are modified, and the modified styrene elastomer of the present invention may be one in which some living ends are modified. As the modifying agent, for example, a terminal modification treatment agent described in Japanese Patent Publication No. 4-39495 can be used.

  The modified styrene elastomer in the present invention can be made into a hydrogenated modified styrene elastomer by hydrogenation. The method of hydrogenation is not particularly limited. For example, a hydrogenation catalyst such as a titanocene compound or a reducing organometallic compound can be used as described in JP-B-1-37970 and JP-B-1-53851. In the presence, hydrogen gas can be introduced and pressurized to a predetermined pressure. The hydrogenation reaction may be performed after the addition reaction of the modifier when the styrene-based elastomer has a living end, and it may be performed either before or after the addition reaction of the modifier when it does not have a living end. Also good.

  The production method of the unmodified styrene elastomer is not particularly limited. For example, n-butyllithium or the like known to have anionic polymerization activity between a vinyl aromatic compound such as styrene and a conjugated diene such as butadiene. The aliphatic hydrocarbon alkali metal compound can be used for copolymerization in a tank reactor equipped with a stirrer. The copolymerization method may be batch polymerization, continuous polymerization, or a combination thereof.

  Examples of the styrene elastomer include styrene-butadiene-styrene block copolymer (SBS), styrene-isoprene-styrene block copolymer (SIS), styrene-ethylene-butylene-styrene block copolymer (SEBS), and styrene. -Ethylene-propylene-styrene block copolymer (SEPS), styrene-ethylene-ethylene-propylene-styrene block copolymer (SEEPS), styrene-butadiene-butylene-styrene block copolymer (SBBS) and the like. Among these, those in which intramolecular unsaturated double bonds other than aromatic rings are hydrogenated, such as styrene-ethylene-butylene-styrene block copolymer (SEBS), are used from the viewpoint of avoiding deterioration of dielectric properties due to oxidation. preferable. Examples of commercially available unmodified styrenic elastomers include “Septon S8104” (SEBS manufactured by Kuraray Co., Ltd.), “Tuftec H1043” (SEBS manufactured by Asahi Kasei Chemicals Co., Ltd.), and the like.

  The modified styrenic elastomer in the present invention preferably has a weight average molecular weight of 10,000 to 1,000,000. When the weight average molecular weight is lower than the lower limit of the above range, not only the heat resistance is lowered, but also the adhesion strength between the copper foil and the plated conductor layer tends to be lowered. Moreover, when the weight average molecular weight is higher than the upper limit of the above range, the solubility in a solvent and the compatibility with a vinylbenzyl resin tend to be reduced.

  In the present invention, the weight average molecular weight is a value measured by gel permeation chromatography (GPC) method (polystyrene conversion). Specifically, the weight average molecular weight by the GPC method is LC-9A / RID-6A manufactured by Shimadzu Corporation as a measuring device, and Shodex K-800P / K-804L / K manufactured by Showa Denko KK as a column. -804L can be measured using chloroform as a mobile phase at a column temperature of 40 ° C. and calculated using a standard polystyrene calibration curve.

  In the modified styrene elastomer of the present invention, the content of styrene is preferably 20 to 80% by mass, and more preferably 30 to 70% by mass. When the styrene content is lower than the above range, the compatibility with the vinyl benzyl ether resin tends to be reduced, and when the content is higher than the above range, the adhesion strength with the copper foil or the plated conductor layer tends to be reduced. . The styrene content can be adjusted from the reaction ratio of a vinyl aromatic compound such as styrene and a conjugated diene such as butadiene, and the styrene content can be determined by, for example, a modified styrene having a constant concentration by an ultraviolet spectrophotometer. It can be determined by measuring the absorbance value of the styrene site in the system elastomer solution.

  As the modified styrenic elastomer in the present invention, a commercially available one can be used. Examples of commercially available products include “Septon HG252” (manufactured by Kuraray Co., Ltd.), which is a modified styrene elastomer (modified SEEPS) having a hydroxyl group, and a modified styrene elastomer (modified SBBS) having a carboxyl group. “Tuftec N503M”, “Tuftec N501” which is a modified styrene elastomer (modified SBBS) having an amino group, “Tuftec M1913” which is a modified styrene elastomer (modified SEBS) having an acid anhydride group (all Asahi Kasei Chemicals ( And the like).

  Two or more different types of modified styrenic elastomers in the present invention may be mixed and used.

  The mass ratio of the curable polyvinyl benzyl ether compound (component A) and the modified styrene elastomer (component B) in the curable resin composition of the present invention is preferably 97: 3 to 50:50, more preferably 90:10. More preferably, it is ˜70: 30. If the ratio of the curable polyvinyl benzyl compound is too large, there is a tendency that a sufficient effect cannot be obtained in the adhesion with the copper foil or the plated conductor layer, and if it is too small, the inherent characteristics of the curable polyvinyl benzyl ether compound such as dielectric properties. Tend not to be fully utilized.

  The curable resin composition of this invention may contain the other polymerizable compound as needed. Examples of the polymerizable compound include styrene, divinylbenzene, allyl ester, acrylate, and methacrylate. If necessary, other resins such as a thermosetting resin, for example, an epoxy resin, a brominated epoxy resin, a maleimide resin, a cyanate resin and the like may be contained. The curable polyvinyl benzyl compound in the present invention can be cured without a curing catalyst at the time of thermosetting, but when other polymerizable compounds or resins are blended, a curing catalyst suitable for them is appropriately selected. It may be added. For example, when allyl ester is added, a radical polymerization initiator having a relatively long half-life such as dicumyl peroxide, 1,1-bis (t-butylperoxy) 3,3,5-trimethylcyclohexane is used. It is preferable to add it as a curing catalyst. The amount used in the case of using a curing catalyst is usually in the range of 0.1 to 10% by mass relative to the amount. These components are preferably contained in a proportion of 30 parts by mass or less when the total of components (A) and (B) contained in the curable resin composition is 100 parts by mass.

In addition, an organic filler or an inorganic filler can be added to the curable resin composition of the present invention in order to improve the mechanical strength or flame retardancy of the cured product. Examples of the organic filler include acrylic rubber fine particles having a core-shell structure, silicon powder, and nylon powder. Examples of the inorganic filler include silica, alumina, magnesium hydroxide, aluminum hydroxide, zinc borate, and antimony oxide. Can be mentioned. In particular, an inorganic filler such as silica can be contained for the purpose of reducing the thermal expansion coefficient of the curable resin composition. In this case, the inorganic filler is contained in the curable resin composition in an amount of preferably 30 to 70% by mass, and more preferably 40 to 60% by mass. The average particle size of the inorganic filler is preferably 0.01 to 5 μm or less. Moreover, what removed the particle | grains 10 micrometers or more is preferable. The average particle diameter can be measured by a laser diffraction / scattering method based on the Mie scattering theory. Specifically, the particle size distribution of the filler is created on a volume basis by a laser diffraction particle size distribution measuring device, the median diameter (d ₅₀ ) is measured, and the median diameter is defined as the average particle diameter. A measurement sample in which filler powder is dispersed in water by ultrasonic waves can be preferably used. As a laser diffraction type particle size distribution measuring apparatus, LA-500 manufactured by Horiba Ltd. can be used. The inorganic filler may be used after being surface-treated with a surface treatment agent such as a silane surface treatment agent.

  The curable resin composition of the present invention can be suitably used as a material for electronic components represented mainly by circuit boards. The curable resin composition of the present invention is dissolved in an organic solvent to form a varnish, the resin varnish is applied onto a support film or copper foil, and the organic solvent is dried by heating, hot air blowing, etc. By forming the composition layer, it can be used in the form of an adhesive film. Since the curable resin composition of the present invention can be formed into a film in this way, the productivity of electronic parts such as multilayer printed wiring boards can be improved, and the insulating layer thickness can be easily reduced. This is suitable for the manufacture of electronic parts such as printed wiring boards that are required to be manufactured.

  The drying conditions of the resin varnish are not particularly limited, but the resin varnish is dried so that the content of the organic solvent in the resin composition layer is usually 5% by mass or less, preferably 3% by mass or less. For example, if it is a varnish containing 30-60 mass% of organic solvents, it can be dried at 50-150 degreeC for about 3 to 10 minutes. As drying conditions, suitable drying conditions can be appropriately set by simple experiments. In the adhesive film, the thickness of the resin composition layer to be formed is usually not less than the thickness of the conductor layer. Since the thickness of the conductor layer of the circuit board is usually in the range of 5 to 70 μm, the thickness of the resin composition layer is preferably 10 to 100 μm.

  The organic solvent used for preparing the resin varnish is not particularly limited, but ketones such as methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate, carbitol acetate, etc. Acetic esters, cellosolves such as cellosolve and butylcellosolve, carbitols such as carbitol and butylcarbitol, aromatic hydrocarbons such as toluene, xylene and solvent naphtha, N, N-dimethylformamide, N, N-dimethylacetamide And amides such as N-methylpyrrolidone. These organic solvents can be used in combination of two or more.

  Examples of the material for the support film in the adhesive film of the present invention include polyolefins such as polyethylene and polypropylene, and polyesters such as polyethylene terephthalate and polyethylene naphthalate. Polyethylene terephthalate is particularly preferable. These support film surfaces may be subjected to a release treatment in addition to the mud treatment and the corona treatment. Although the thickness of a support film is not specifically limited, Usually, it is 10-150 micrometers, Preferably it is used in 25-50 micrometers. The curable resin composition layer may be protected with a protective film. By protecting with a protective film, it is possible to prevent dust and the like from being attached to the surface of the resin composition layer and scratches. The same material as the support film can be used as the protective film. The thickness of the protective film is preferably 1 to 40 μm.

  As copper foil in the adhesive film with copper foil of the present invention, in addition to electrolytic copper foil, rolled copper foil, etc., ultrathin copper foil with carrier, peelable film such as polyethylene terephthalate subjected to release treatment, copper What formed the vapor deposition layer etc. can be used.

  The thickness of the copper foil is usually preferably 9 to 35 μm. In the case of an ultrathin copper foil with a carrier, a copper foil of 1 to 5 μm is preferably used. Moreover, in the case of the copper vapor deposition film in which the copper vapor deposition layer was formed in the peelable film, the thickness of the vapor deposition layer is usually 100 to 5000 mm.

  In order that the copper foil used for this invention may improve the adhesive strength by a throwing effect, it is preferable that the surface by which the curable resin composition of this invention is layered is roughened. The method of the roughening treatment is not particularly limited. For example, the method of roughening by etching or the copper foil is immersed in an aqueous copper sulfate solution, and copper is deposited by electrolysis to form fine copper particles on the surface of the copper foil. It can carry out by well-known methods, such as the method of doing. Moreover, after a surface roughening process, you may give a rust prevention process or the process which improves adhesiveness with resin, such as a chromate process and a blackening process. From the viewpoint of suppressing transmission loss, the surface roughness (Rz) of the copper foil is preferably 6.0 μm or less, more preferably 4.0 μm or less, and even more preferably 3.0 μm or less. The surface roughness in the present invention is defined by the ten-point average roughness (Rz) in JIS B 0601-1994 “Definition and display of surface roughness”.

  Commercially available copper foils include JTC-LP foil, JTC-AM foil (all manufactured by Nikko Materials Co., Ltd.), GTS-MP foil, F2-WS (all manufactured by Furukawa Circuit Foil Co., Ltd.), etc. Is mentioned.

  From the viewpoint of forming a fine circuit on the surface of the cured product, the curable resin composition of the present invention is used in the form of an adhesive film with a copper foil, and after removing the copper foil by etching, a conductor layer is formed by plating. preferable. In this case, after laminating the adhesive film with copper foil on the circuit board and thermosetting the curable resin composition, the copper foil layer is dissolved and removed, and then the surface of the cured product from which the copper foil layer has been removed is treated with an aqueous alkaline oxidant solution. Roughen with After removing the copper foil layer, irregularities are formed on the surface of the cured product, but it is preferable to further roughen the surface of the cured product with an alkaline oxidant solution in order to obtain a plated conductor layer with high adhesion strength. Although a circuit can be formed on the copper foil layer without dissolving and removing the copper foil layer, the electrolytic copper foil and the rolled copper foil are disadvantageous for forming a fine circuit. In addition, the ultrathin copper foil and the copper vapor-deposited film are expensive, and there are problems such as insufficient workability when producing the adhesive film with a copper foil of the present invention. Therefore, as described above, formation of a conductor layer by plating is advantageous for forming a fine circuit.

  Adhesive film having a layer structure of protective film / curable resin composition layer / support film, and protective film / curable resin composition layer / copper foil layer structure in which the curable resin composition layer is protected by a protective film The adhesive film with copper foil having can be rolled up and stored.

  The curable resin composition of the present invention is prepared by preparing a resin varnish as described above, impregnating the resin varnish into a sheet-like fiber base material such as a cloth or a nonwoven fabric by a hot melt method, a solvent method, or the like, and drying the prepreg. It can also be used in the form. In the hot melt method, without dissolving the resin in an organic solvent, the resin is once coated on the resin and a coated paper having good releasability, and then laminated on a sheet-like reinforcing substrate or directly applied by a die coater. Thus, a prepreg is manufactured. Similarly to the adhesive film, the solvent method is a method in which a sheet-like reinforcing base material is immersed in a resin varnish in which a resin is dissolved in an organic solvent, the resin varnish is impregnated into the sheet-like reinforcing base material, and then dried.

  Examples of the sheet-like fiber base material used for the prepreg of the present invention include cloth and nonwoven fabric. Examples of the cloth include glass cloth, aramid cloth, carbon cloth, stretched porous polytetrafluoroethylene, and the like. Examples of the nonwoven fabric include an aramid nonwoven fabric and glass paper.

A method for producing the multilayer printed wiring board of the present invention using the adhesive film with copper foil of the present invention will be described. When the resin composition layer is protected with a protective film, after peeling them off, an adhesive film is laminated on one side or both sides of the circuit board so that the resin composition layer is in contact with the circuit board. Lamination is preferably performed under reduced pressure using a vacuum laminator. The lamination method may be a batch method or a continuous method using a roll. Moreover, you may heat an adhesive film and a circuit board as needed before laminating. The press temperature is preferably 70 to 140 ° C., the press pressure is preferably 1 to 11 kgf / cm ² (9.8 × 10 ^{4 to} 107.9 × 10 ⁴ N / m ² ), and the air pressure in the vacuum laminator is 20 mmHg ( It is preferable to laminate under a reduced pressure of 26.7 hPa) or less.

  The vacuum lamination can be performed using a commercially available vacuum laminator. Commercially available vacuum laminators include, for example, a vacuum applicator manufactured by Nichigo Morton Co., Ltd., a vacuum pressurizing laminator manufactured by Meiki Seisakusho Co., Ltd., a roll dry coater manufactured by Hitachi Industries, Ltd., and Hitachi AIC Co., Ltd. ) Made vacuum laminator and the like.

  Although it does not specifically limit as a circuit board in this invention, The circuit was mainly formed in the single side | surface or both surfaces of boards, such as a glass epoxy, a metal board | substrate, a polyester board | substrate, a polyimide board | substrate, a BT resin board | substrate, and a thermosetting type polyphenylene ether board | substrate. Say. Further, a multilayer printed wiring board in which conductor layers (circuits) and insulating layers are alternately formed and a circuit is formed on one or both surfaces of the outermost layer is also included in the circuit board referred to in the present invention. The surface of the conductor circuit layer is preferably roughened by blackening or the like in advance from the viewpoint of adhesion of the insulating layer to the circuit board.

  After the laminating step, the resin composition layer of the adhesive film with copper foil laminated on the circuit board is cured by thermosetting. The thermosetting conditions are usually selected in the range of 150 ° C. to 220 ° C. for 20 minutes to 180 minutes, and more preferably in the range of 160 ° C. to 200 ° C. for 30 to 120 minutes. Next, the copper foil is removed by dissolution with an etching solution. Examples of the etching solution include a ferric chloride solution and a cupric chloride solution. An uneven surface is formed on the surface of the cured product from which the copper foil has been dissolved and removed by the etching solution.

  Next, if necessary, a hole is formed in the insulating layer (cured product) formed on the circuit board to form a via hole or a through hole. Drilling can be performed by a known method such as drilling, laser, or plasma, or a combination of these methods, but drilling by a laser such as a carbon dioxide laser or YAG laser is the most common method.

  Next, the surface of the insulating layer is roughened with an aqueous alkaline oxidizer solution. When drilling, this process also serves as a desmear process in the hole. Examples of the alkaline oxidizing agent aqueous solution include aqueous solutions of potassium permanganate, sodium permanganate and the like. Thus, by combining the dissolution removal treatment with the etching solution of the copper foil and the surface treatment with the alkaline oxidant aqueous solution described later on the cured product surface after the dissolution removal treatment, it is suitable for forming a conductor layer by plating on the cured product surface. An uneven surface can be formed, and a plated conductor layer having excellent adhesion strength can be formed.

  A conductor layer can be formed on the cured product surface by a method combining electroless plating and electrolytic plating. As a conductor layer, a copper layer is usually formed by copper plating. Further, a plating resist having a pattern opposite to that of the conductor layer can be formed, and the conductor layer can be formed only by electroless plating. After forming the conductor layer, for example, annealing may be performed at 150 to 200 ° C. for about 20 to 90 minutes. As a method for forming a circuit by patterning the conductor layer, for example, a subtractive method or a semi-additive method known to those skilled in the art can be used.

  Conductive layer formation by plating is suitable for forming fine circuits because the conductive layer thickness can be reduced. If the requirements of the circuit pitch are satisfied, the copper foil layer can be patterned as it is by a subtractive method or the like to form a circuit.

  A method for producing the multilayer printed wiring board of the present invention using the adhesive film of the present invention will be described. The laminating method and conditions are the same as those of the adhesive film with copper foil. After laminating the adhesive film on the circuit board, when the support film is peeled off, the insulating film can be formed on the circuit board by peeling and thermosetting. The conditions for heat curing are the same as described above. If the support film is not peeled off before thermosetting and a support film exists after thermosetting, it is peeled off. Next, if necessary, a hole is formed in the insulating layer (cured product) formed on the circuit board to form a via hole or a through hole. The drilling method and conditions are the same as described above. Next, the surface of the insulating layer is roughened with an aqueous alkaline oxidizer solution. The method and conditions for the roughening treatment are the same as described above. A conductor layer is formed on the surface of the cured product on which the rough surface has been formed by the roughening treatment by a method combining electroless plating and electrolytic plating. Further, a plating resist having a pattern opposite to that of the conductor layer can be formed, and the conductor layer can be formed only by electroless plating. After forming the conductor layer, for example, annealing may be performed at 150 to 200 ° C. for about 20 to 90 minutes. As a method for forming a circuit by patterning the conductor layer, for example, a subtractive method or a semi-additive method known to those skilled in the art can be used.

Next, a method for producing the multilayer printed wiring board of the present invention using the prepreg of the present invention will be described. One or several prepregs of the present invention are stacked on a circuit board, a metal plate is sandwiched through a release film, and press lamination is performed under pressure and heating conditions. The pressure is preferably 5 to 50 kgf / cm ² and the temperature is preferably 100 to 200 ° C. for 20 to 100 minutes. Moreover, it can also be manufactured by laminating on a circuit board by a vacuum laminating method as in the case of an adhesive film, and then curing by heating. Thereafter, similarly to the method described above, the surface of the prepreg cured with an alkaline oxidant aqueous solution is roughened, and then a conductor layer is formed by plating to produce a multilayer printed wiring board.

  The curable resin composition of the present invention is suitably used as an insulating material for various electronic parts such as a transmitter, a resonator, a capacitor, an antenna, a power amplifier, a filter, an RF module, and an inductor in addition to a multilayer printed wiring board. Can do.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

  Polyvinylbenzyl ether compound toluene varnish (Showa High Polymer Co., Ltd. V1100X, nonvolatile content 60%) 40 parts by mass [resin component 24 parts by mass], carboxyl group-modified styrene elastomer (modified SBBS) (Asahi Kasei Chemicals Corporation) N503M, styrene content 30%), 6 parts by mass, and 18 parts by mass of toluene were added and stirred until completely dispersed to prepare a varnish-like curable resin composition. The curable resin composition varnish is applied onto a 38 μm thick polyethylene terephthalate (hereinafter abbreviated as PET) film, dried at 70 to 120 ° C. for 12 minutes, and a curable resin composition layer having a thickness of 50 μm is adhered. A film was obtained. Moreover, said varnish-like resin composition is apply | coated on the copper foil of the electrolytic copper foil (F2-WS foil, thickness 18micrometer, Rz = 2.3micrometer of a process surface) by Furukawa Circuit Foil, 70-120 The film was dried at 20 ° C. for 12 minutes to obtain an adhesive film with a copper foil having a thickness of 50 μm of the curable resin composition layer.

Toluene varnish of polyvinyl benzyl ether compound (V1100X, Showa High Polymer Co., Ltd. V1100X, nonvolatile content 60%) 36.3 parts [resin component 21.8 parts by weight], modified styrene elastomer having acid anhydride group (modified SEBS ) (M1913 manufactured by Asahi Kasei Chemicals Co., Ltd., styrene content 30%) After adding 5.5 parts by mass and 18 parts by mass of toluene, a trifunctional acrylate monomer having an isocyanuric skeleton copolymerizable with a polyvinylbenzyl ether compound (Japan) 2.7 parts by mass of Kayaku Co., Ltd. KAYARAD R790) was added and stirred until completely dispersed to prepare a varnish-like curable resin composition. The curable resin composition varnish was applied on a PET film having a thickness of 38 μm and dried at 70 to 120 ° C. for 12 minutes to obtain an adhesive film having a thickness of 50 μm of the curable resin composition layer. Further, the curable resin composition varnish described above was applied onto a copper foil of Furukawa Circuit Foil Co., Ltd. electrolytic copper foil (F2-WS foil, thickness 18 μm, treated surface Rz = 2.3 μm), 70 It dried at -120 degreeC for 12 minutes, and obtained the adhesive film with a copper foil whose thickness of a curable resin composition layer is 50 micrometers.
<Comparative Example 1>

  Polyvinylbenzyl ether compound toluene varnish (Showa Polymer Co., Ltd. V1100X, nonvolatile content 60%) 40 parts by mass [resin component 24 parts by mass], unsaturated double bond styrene-butadiene-styrene block hydrogenated 6 parts by mass of a copolymer (manufactured by Kuraray Co., Ltd. S8104, styrene content 60%) and 18 parts by mass of toluene were added and stirred until completely dispersed to prepare a varnish-like curable resin composition. The curable resin composition varnish was applied on a PET film having a thickness of 38 μm and dried at 70 to 120 ° C. for 12 minutes to obtain an adhesive film having a thickness of 50 μm of the curable resin composition layer. Moreover, said varnish-like resin composition is apply | coated on the copper foil of the electrolytic copper foil (F2-WS foil, thickness 18micrometer, Rz = 2.3micrometer of a process surface) by Furukawa Circuit Foil, 70-120 The film was dried at 20 ° C. for 12 minutes to obtain an adhesive film with a copper foil having a thickness of 50 μm of the curable resin composition layer.

[Measurement of relative dielectric constant (εr) and dielectric loss tangent (tan δ) of curable resin composition]
The resin surfaces of the adhesive film obtained on the PET film were put together and laminated by a vacuum laminator at a temperature of 80 ° C., a pressure of 1 kgf / cm 2 (9.8 × 104 Pa), an air pressure of 5 mmHg (6.7 × 10 2 Pa) or less. . After laminating, the PET film was peeled, and the resin surfaces of the adhesive film were put together to repeat lamination, PET film peeling and laminating under the same conditions to produce a resin plate having a thickness of about 1.2 mm. This resin plate is put into a 100 mm × 100 mm × 1 mm mold, subjected to pressure vacuum press molding at a pressure of 150 ° C./30 minutes + 180 ° C./90 minutes, 50 MPa, and further post-cure thickness after 180 ° C./60 minutes. A 1 mm thick cured resin plate was obtained.

  The obtained cured resin plate was cut into a length of 80 mm and a width of 2 mm to obtain an evaluation sample. With respect to this evaluation sample, relative permittivity and dielectric loss tangent were measured at a measurement frequency of 5.8 GHz and a measurement temperature of 23 ° C. by a cavity resonance perturbation method using an HP 8362B apparatus manufactured by Agilent Technologies.

[Peel strength measurement]
An adhesive film with copper foil is laminated on a copper plate by a vacuum laminator under conditions of a temperature of 120 ° C., a pressure of 5 kgf / cm (4.9 × 10 ⁵ Pa), and an air pressure of 5 mmHg (6.7 × 10 ² Pa) or less. The resin composition sandwiched between the conductor layers was heated at 180 ° C. for 2 hours to produce a peel strength measurement sample. For peel strength measurement by plating, an adhesive film with copper foil is placed on a copper plate with a vacuum laminator at a temperature of 120 ° C., a pressure of 5 kgf / cm (4.9 × 10 ⁵ Pa), an air pressure of 5 mmHg (6.7 × 10 ² Pa). ) After lamination under the following conditions, after curing at 180 ° C. for 30 minutes, the copper foil portion is dissolved and removed, the surface of the adhesive film is roughened with an aqueous alkaline oxidant solution, and the conductor layer is formed by plating. A sample was used. The peel strength of the sample was evaluated according to Japanese Industrial Standard (JIS) C6481.

  The compositions of the curable resin compositions of Examples 1 and 2 and Comparative Example 1 are shown in Table 1, and the results of each test are shown in Table 2.

  From Table 2, it can be seen that according to the curable resin composition of the present invention, good adhesion to the copper foil and plated copper can be achieved without impairing the excellent properties of the curable polyvinyl benzyl ether compound.

Claims (15)

(A) a curable polyvinyl benzyl ether compound, and (B) a modified styrenic elastomer having one or more functional groups selected from the group consisting of a hydroxyl group, a carboxyl group, an amino group, and an acid anhydride group A curable resin composition. (A) The curable polyvinyl benzyl ether compound has the following formula (1):

[In the formula (1), R ¹ is a methyl group or an ethyl group, R ² is a hydrogen atom or a hydrocarbon group of 1 to 10, a R ³ hydrogen atom or a vinylbenzyl group (provided that the molar ratio of a hydrogen atom to a vinylbenzyl group) Is in the range of 60:40 to 0: 100), and n represents an integer of 2 to 4. ]
The curable resin composition of Claim 1 which is a curable polyvinyl benzyl ether compound represented by these. (B) The curable resin composition according to claim 1, wherein the functional group of the modified styrene elastomer is at least one selected from the group consisting of a carboxyl group and an acid anhydride group. The curable resin composition according to claim 1, wherein the mass ratio of the component (A) to the component (B) is 97: 3 to 50:50. The adhesive film by which the curable resin composition of Claims 1-4 was layer-formed on the support film. The adhesive film with copper foil in which the curable resin composition of Claims 1-4 was layer-formed on copper foil. A prepreg comprising a sheet-like fiber base material impregnated with the curable resin composition according to claim 1. A method for producing a multilayer printed wiring board comprising the following steps (1) to (7):
(1) Laminating the adhesive film according to claim 5 on a circuit board,
(2) A step of peeling or not peeling the support film,
(3) a step of thermosetting the curable resin composition;
(4) a step of peeling the support film when the support film is present;
(5) A step of roughening the surface of the cured product with an aqueous alkaline oxidant solution,
(6) A step of forming a conductor layer on the roughened cured product surface by plating, and (7) a step of forming a circuit on the conductor layer. A method for producing a multilayer printed wiring board including the following steps (1) to (6):
(1) A step of laminating the adhesive film with copper foil according to claim 6 on a circuit board,
(2) a step of thermosetting the curable resin composition;
(3) a step of dissolving and removing the copper foil,
(4) A step of roughening the surface of the cured product with an aqueous alkaline oxidant solution,
(5) A step of forming a conductor layer on the roughened cured product surface by plating, and (6) a step of forming a circuit on the conductor layer. A method for producing a multilayer printed wiring board comprising the following steps (1) to (3):
(1) A step of laminating the adhesive film with copper foil according to claim 6 on a circuit board,
(2) a step of thermosetting the curable resin composition, and (3) a step of forming a circuit on the copper foil layer. A method for producing a multilayer printed wiring board including the following steps (1) to (5):
(1) A step of laminating the prepreg according to claim 7 on a circuit board,
(2) a step of thermosetting the curable resin composition;
(3) a step of roughening the surface of the cured product with an aqueous alkaline oxidant solution;
(4) A step of forming a conductor layer on the roughened cured product surface by plating, and (5) a step of forming a circuit on the conductor layer. The multilayer printed wiring board by which one part or all part of the insulating layer is formed with the hardened | cured material of the curable resin composition of any one of Claims 1-4. The electronic component by which one part or all part of the insulating layer is formed with the hardened | cured material of the curable resin composition of any one of Claims 1-4. A multilayer printed wiring board in which a part or all of the insulating layer is formed of a cured product of the prepreg according to claim 7. An electronic component in which a part or all of the insulating layer is formed of a cured product of the prepreg according to claim 11.