TWI818994B - Thermosetting resin compositions, films containing the same, and multilayer wiring boards using the same - Google Patents

Abstract

The present invention provides the following film and a thermosetting resin composition used for production of the film. This film has excellent adhesion strength to metal foil and substrate materials used as wiring on printed circuit boards. Furthermore, the film exhibits excellent electrical properties in the high-frequency region. Specifically, the film shows low dielectric constant (ε) and low dielectric tangent (tanδ) in the frequency range of 1 to 100 GHz. Furthermore, the film can be hardened at lower temperatures. The thermosetting resin composition used for the production of the film contains (A) a thermosetting resin having a styrene group at the end, (B) a styrene-based thermoplastic elastomer, (C) a thioether-based silane coupling agent, and (D) )Dialkyl peroxide-based free radical polymerization initiator.

Description

Thermosetting resin compositions, films containing the same, and multilayer wiring boards using the same

The present invention relates to a thermosetting resin composition, a resin film containing the same, and a multilayer wiring board using the same.

In recent years, electrical. Printed wiring boards used in electronic equipment have been progressing towards miniaturization, weight reduction and high performance of the equipment. In particular, multilayer printed wiring boards are required to have higher multilayering, higher density, thinner thickness, lighter weight, higher reliability, and molding processability.

In addition, in accordance with the recent demand for high-speed transmission signals on printed wiring boards, the frequency of transmission signals has been significantly advanced. Therefore, materials used in printed wiring boards are required to reduce electrical signal loss in the high-frequency region, specifically in the frequency region above 1 GHz.

On the other hand, adhesive films used as interlayer adhesives used in multilayer printed wiring boards and as surface protective films (i.e., cover films) of printed wiring boards are required to exhibit excellent electrical properties in the high-frequency region (low dielectric constant (ε) and low dielectric tangent (tanδ)).

The applicant of this case proposes a resin film and a resin composition used for manufacturing the resin film in Patent Document 1. This resin film is It has excellent bonding strength to FPC substrate materials such as metal foil and polyimide film that become the wiring of FPC. Moreover, the resin film shows excellent electrical properties in the high-frequency region of 1 to 10 GHz. Specifically, the resin film shows low dielectric constant (ε) and low dielectric tangent (tanδ) in the frequency range of 1 to 10 GHz.

[Prior technical literature] [Patent Document]

[Patent Document 1] Japanese Patent Application Publication No. 2016-89137

The resin composition described in Patent Document 1 uses a thermosetting resin having a styrene group at the terminal in order to obtain excellent electrical characteristics in a high-frequency region.

On the other hand, from the viewpoint of low thermal expansion coefficient (CTE), it is known to mix glass cloth or filler with thermosetting resin.

When glass cloth or filler is used, the bonding strength of the thermosetting resin to the copper foil is reduced. Therefore, in order to improve the adhesion to copper foil, Patent Document 1 proposes adding a thioether-based silane coupling agent to a thermosetting resin.

However, the applicant found the following points. That is, in order to harden the thermosetting resin with a terminal styrene group, it is necessary to heat it at a high temperature. Furthermore, when a thioether-based silane coupling agent is added to a thermosetting resin, free radicals The polymerization reaction temperature will further shift to the high temperature side.

In the examples described below, the heat generation peak obtained by differential scanning calorimetry (DSC) was used as the evaluation of the hardening characteristics. Regarding this, the applicant found the following points. That is to say, the heat peak value obtained by DSC for thermosetting resins with terminal styrene groups is as high as about 200°C. Furthermore, when a thioether-based silane coupling agent is added to the thermosetting resin with a terminal styrene group, the heat generation peak obtained by DSC further increases by more than 30°C. From this phenomenon, it can be seen that under the curing conditions (for example, 200° C., 60 minutes) when no thioether-based silane coupling agent is added, the thermosetting resin is not sufficiently cured and the original characteristics may not be obtained.

An object of this disclosure is to provide the following film and a thermosetting resin composition used in the production of the film. This film has excellent adhesion strength to metal foil and substrate materials used as wiring on printed circuit boards. Furthermore, the film exhibits excellent electrical properties in the high-frequency region. Specifically, the film shows low dielectric constant (ε) and low dielectric tangent (tanδ) in the frequency range of 1 to 100 GHz. Furthermore, this film has more excellent curability.

In order to achieve the above object, one aspect of the present disclosure provides a thermosetting resin composition (this thermosetting resin composition), which is characterized by containing (A) a thermosetting resin having a styrene group at the end, ( B) Styrene-based thermoplastic elastomer, (C) thioether-based silane coupling agent, and (D) Dialkyl peroxide-based radical polymerization initiator.

In the present thermosetting resin composition, it is preferable that the thermosetting resin of the component (A) is a thermosetting resin having a styrene group at the terminal and a phenylene ether skeleton.

In this thermosetting resin composition, it is preferable that the number average molecular weight (Mn) of the thermosetting resin of the component (A) is 1,000 to 5,000.

In this thermosetting resin composition, it is preferable that the styrenic thermoplastic elastomer system of the component (B) is hydrogenated.

In this thermosetting resin composition, the aforementioned component (C) is preferably a thioether-based silane coupling agent or a polythioether-based silane coupling agent.

The thermosetting resin composition preferably further contains (E) a silica filler.

In the present thermosetting resin composition, it is preferred that the silica filler of component (E) is surface-treated with a silane coupling agent.

Moreover, as another aspect of this disclosure, a film (this film) containing this thermosetting resin composition is provided.

Moreover, as another aspect of this disclosure, a cured product of this thermosetting resin composition and a cured product of this film are provided.

Furthermore, as another aspect of the present disclosure, a multilayer wiring board including a cured product of the present thermosetting resin composition and a multilayer wiring board including a cured product of the present film are provided.

This thermosetting resin composition uses thioether silane The coupling agent can also be fully hardened under the same conditions as when not in use.

This film has excellent adhesion strength to metal sheets and substrate materials used as wiring on printed circuit boards. Furthermore, this film exhibits excellent electrical properties in the high-frequency region. Specifically, this film shows low dielectric constant (ε) and low dielectric tangent (tanδ) in the frequency range of 1~100GHz. Therefore, this film is suitable for electrical applications. Adhesive film for electronic applications and covering film for printed wiring boards. Furthermore, this film is suitable for interlayer connection between substrates of semiconductor devices. This film is particularly suitable as an adhesive film for extremely high frequency wave substrates. Furthermore, this film can also be used as the FPC itself.

One embodiment of the thermosetting resin composition of the present disclosure will be described in detail below.

The thermosetting resin composition of this embodiment contains the following components (A) to (D).

(A) Thermosetting resin having a styrene group at the end

The thermosetting resin having a styrene group at the terminal of the component (A) (hereinafter, described as "the thermosetting resin of the component (A)" in this specification) preferably has a styrene group at the terminal and has a phenylene ether. Thermosetting resin for the frame.

The thermosetting resin having a styrene group at the terminal and a phenylene ether skeleton is preferably a compound represented by the following general formula (1).

In formula (1), -(O-X-O)- is represented by the following general formula (2) or (3).

In formula (2), R ₁ , R ₂ , R ₃ , R ₇ and R ₈ are an alkyl group or phenyl group having 6 or less carbon atoms, and may be the same or different from each other. R ₄ , R ₅ and R ₆ are a hydrogen atom, an alkyl group having 6 or less carbon atoms, or a phenyl group, and may be the same or different from each other.

In formula (3), R ₉ , R ₁₀ , R ₁₁ , R ₁₂ , R ₁₃ , R ₁₄ , R ₁₅ and R ₁₆ are hydrogen atoms, alkyl groups with 6 or less carbon atoms or phenyl groups, and may be the same as each other. Can be different. -A- is a linear, branched or cyclic divalent hydrocarbon group having 20 or less carbon atoms.

In formula (1), -(Y-O)- is represented by general formula (4). One structure or two or more structures of -(Y-O)- are randomly arranged.

In formula (4), R ₁₇ and R ₁₈ are an alkyl group or phenyl group having 6 or less carbon atoms, and may be the same or different from each other. R ₁₉ and R ₂₀ are a hydrogen atom, an alkyl group having 6 or less carbon atoms, or a phenyl group, and may be the same or different from each other.

In formula (1), a and b are integers from 0 to 100. At least one of a and b is not 0.

Examples of -A- in formula (3) include methylene, ethylene, 1-methylethylene, 1,1-propylene, and 1,4-phenylenebis(1-methylethylene). Ethyl), 1,3-phenylenebis(1-methylethylene), cyclohexylene, phenylmethylene, naphthylmethylene and 1-phenylethylene, etc. divalent organic base. However, -A- in formula (3) is not limited to these bases.

As the compound represented by formula (1), it is preferable that R ₁ , R ₂ , R ₃ , R ₇ , R ₈ , R ₁₇ and R ₁₈ are alkyl groups having 3 or less carbon atoms, and R ₄ , R ₅ and R _6. R ₉ , R _{10 , R 11 , R 12 , R 13 , R 14 , R 15 , R 16} , R ₁₉ and R ₂₀ are hydrogen atoms or alkyl groups with less than 3 carbon atoms. Particularly more preferably, -(OXO)- represented by the general formula (2) or the general formula (3) is a compound represented by the general formula (5), the general formula (6) or the general formula (7), and the compound represented by the general formula ( 4) The -(YO)- represented is a compound represented by formula (8) or formula (9), or a structure in which a compound represented by formula (8) and a compound represented by formula (9) are randomly arranged.

The method of producing the compound represented by formula (1) is not particularly limited. For example, the compound represented by formula (1) can be produced by etherifying the terminal phenolic hydroxyl group of a bifunctional phenylene ether oligomer obtained by oxidative coupling of a bifunctional phenol compound and a monofunctional phenol compound with a vinyl benzyl group.

The number average molecular weight of the thermosetting resin of component (A) is preferably in the range of 1000 to 5000, more preferably in the range of 1000 to 3000, and more preferably in the range of 1000 to 3000 when converted to polystyrene by the GPC method. The range is 1000~2500. If the number average component is 1000 or more, the resin composition of this embodiment will be less likely to become sticky when it is formed into a coating film. Moreover, when the number average molecular weight is 5,000 or less, the solubility of the resin composition of this embodiment in a solvent can be suppressed from decreasing. Furthermore, by using the thermosetting resin of component (A) whose number average molecular weight falls within the above range, the electrical characteristics and curability at high frequencies of the resin composition of this embodiment can be improved.

(B) Styrenic thermoplastic elastomer

The styrenic thermoplastic elastomer system of component (B) refers to a thermoplastic elastomer containing styrene, its homologues or its analogues.

The presence of unsaturated bonds in the molecule leads to an increase in the dielectric tangent (tanδ). Therefore, it is preferable to use a hydrogenated styrenic thermoplastic elastomer as component (B). By using a hydrogenated styrenic thermoplastic elastomer, a lower dielectric tangent (tanδ) can be obtained compared to the case of using an unhydrogenated one.

Examples of the component (B) include styrene-isoprene-styrene block copolymer (SIS), styrene-butadiene-styrene block copolymer (SBS), styrene-butadiene -Butylene-styrene block copolymer (SBBS), styrene-ethylene-butylene-styrene block copolymer (SEBS), styrene-ethylene-propylene block copolymer (SEP), styrene-ethylene -Propylene-styrene block copolymer (SEPS), styrene-ethylene-ethylene-propylene-styrene block copolymer (SEEPS) and the hydrogenated products of these copolymers. The compounds exemplified here may be used alone, or two or more types may be mixed and used.

The quality ratio of component (A) and component (B) is preferably component (A): component (B) = 10:90~90:10, preferably 20:80~80:20, and even more preferably 20:80 ~50:50.

If the component (B) is too much, the component (A) will be relatively reduced, resulting in poor curability of the thermosetting resin composition of the present embodiment, making it difficult to obtain properties such as peel strength. On the contrary, if the component (A) is too much, the component (B) will be relatively reduced, making the film containing the thermosetting resin composition of the present embodiment and its cured product hard and brittle, thereby impairing the film properties. Therefore, there is a risk that cracks may occur and the properties of the hardened material, such as peel strength, may be reduced.

(C)Thioether silane coupling agent

In the thermosetting resin composition of this embodiment, by containing a thioether-based silane coupling agent as the component (C), the electrical characteristics of a film containing the thermosetting resin composition can be maintained at high frequencies while improving the electrical characteristics of the film. The bonding strength of copper foil, which is widely used for wiring on printed wiring boards. As a result, the risk of the thermosetting resin composition peeling off after bonding can be reduced.

The thioether-based silane coupling agent is preferably a polythioether-based silane coupling agent having two or more thioether bonds.

Examples of the polythioether silane coupling agent include bis(trimethoxysilylpropyl)tetrasulfide, bis(triethoxysilylpropyl)tetrasulfide, and bis(tributoxysilylpropyl) )tetrasulfide, bis(dimethoxymethylsilylpropyl)tetrasulfide, bis(diethoxymethylsilylpropyl)tetrasulfide, bis(di Butoxymethylsilylpropyl)tetrasulfide, bis(trimethoxysilylpropyl)disulfide, bis(triethoxysilylpropyl)disulfide, bis(tributoxysilane) propyl) disulfide, bis(dimethoxymethylsilylpropyl)disulfide, bis(diethoxymethylsilylpropyl)disulfide and bis(dibutoxymethyl) Silylpropyl) disulfide, etc.

The number of thioether bonds in the polythioether silane coupling agent is preferably 2, 3 or 4 from the viewpoint of adhesion, and particularly preferably 4.

Polysulfide is a silane coupling agent. From the viewpoint of stability, the alkoxy group bonded to Si is preferably a methoxy group or an ethoxy group, and more preferably an ethoxy group.

The thioether silane coupling agent of component (C) preferably contains 0.1 to 5.0 parts by mass, more preferably 0.1 to 3.0 parts by mass, based on 100 parts by mass of the total of component (A) and component (B). Contains 0.1~2.0 parts by mass.

(D) Dialkyl peroxide radical polymerization initiator

In the thermosetting resin composition of this embodiment, by blending a dialkyl peroxide-based radical polymerization initiator as the component (D), the thermosetting resin composition having a styrene group at the terminal as the component (A) is contained. It is a curable resin and contains a thioether-based silane coupling agent as component (C), which can still suppress the radical polymerization reaction temperature from shifting to the high temperature side. As radical polymerization initiators, diyl peroxides, hydrogen peroxides, ketone peroxides, etc. also exist. However, it is difficult for these radical polymerization initiators to suppress the radical polymerization reaction temperature from shifting to the high temperature side.

Dialkyl peroxide-based radical polymerization starter as component (D) The agent is preferably used when it is solid at room temperature. Those that are solid at room temperature are not easily volatile and therefore have excellent handling properties.

The dialkyl peroxide of component (D) is a radical polymerization initiator. From the viewpoint of storage stability, dicumyl peroxide (manufactured by NOF Co., Ltd., brand name: PERCUMYL D) is preferred.

The dialkyl peroxide of component (D) is a radical polymerization initiator. It is preferably 0.1 to 5.0 parts by mass, more preferably 0.1 to 5.0 parts by mass relative to 100 parts by mass of the total of component (A) and component (B). 3.0 parts by mass, preferably 0.1~2.0 parts by mass.

The thermosetting resin composition of the present disclosure may, in addition to the above-mentioned components (A) to (D), also contain the following components as necessary.

(E)Silicon oxide filler

When a silica filler is included as component (E), the coefficient of thermal expansion (CTE) of a film containing the thermosetting resin composition of the present disclosure can be reduced.

When the silica oxide filler of component (E) is surface-treated with a silane coupling agent, it is preferable because the moisture resistance reliability can be improved (the change rate of dielectric constant and dielectric tangent is small).

The silane coupling agent used for surface treatment is preferably represented by the following general formula (10).

In the above formula, R ¹ to R ³ are each independently an alkyl group having 1 to 3 carbon atoms, R ⁴ is a functional group having at least an unsaturated double bond at the end, and n is 3 to 9. From the viewpoint of improving the peel strength, R ⁴ in the general formula (10) is preferably any one of a vinyl group, a (meth)acrylyl group and a (meth)acryloxy group. In the general formula (10), when n is 5 to 9, excellent welding heat resistance is obtained because the stress of the hardened product of the thermosetting resin composition is relaxed against external forces. Especially when R ⁴ is vinyl, extremely excellent welding heat resistance is obtained.

From the viewpoint of improving the peel strength, R ⁴ in the general formula (10) is preferably vinyl. In addition, in the general formula (10), n is preferably 3 or 4 from the viewpoint of low thermal expansion.

Examples of the silane coupling agent represented by the general formula (10) include octenyltrialkoxysilane and (meth)acryloxyalkyltrialkoxysilane. Examples of octenyltrialkoxysilane include octenyltrimethoxysilane, octenyltriethoxysilane, and the like. Examples of (meth)acryloxyalkyltrialkoxysilane include (meth)acryloxyoctyltrimethoxysilane and (meth)acryloxyoctyltriethoxysilane. From the viewpoint of improving peel strength, octenyltrimethoxysilane is preferably used. Examples of commercially available silane coupling agents represented by general formula (10) include octenyltrimethoxysilane (product name: KBM-1083) manufactured by Shin-Etsu Chemical Co., Ltd. and methacryloxyoctyltrimethoxysilane manufactured by Shin-Etsu Chemical Co., Ltd. Silane (product name: KBM-5803).

Examples of silane coupling agents other than the above include 3-methacryloxypropyltrimethoxysilane. An example of a commercially available silane coupling agent is 3-methacryloxypropyltrimethoxysilane (product name: KBM-503) manufactured by Shin-Etsu Chemical Co., Ltd.

The silane coupling agent used for surface treatment may be alone or in combination of two or more.

Examples of the silica filler as component (E) include fused silica, ordinary silica, spherical silica, crushed silica, crystalline silica and amorphous silica, and are not particularly limited. From the viewpoints of the dispersibility of the silica filler, the fluidity of the thermosetting resin composition, the surface smoothness of the cured product, dielectric properties, low thermal expansion and adhesiveness, etc., the silica filler is preferably spherical molten silica. . The average particle size of the silica filler (when it is not spherical, its average maximum diameter) is not particularly limited. However, considering that the moisture resistance after hardening is improved when the specific surface area is small, the average particle size of the silica filler is preferably 0.05 to 20 μm, more preferably 0.1 to 15 μm, and still more preferably 0.5 to 10 μm. Here, the average particle diameter of the silica filler means the volume-based median diameter measured by a laser scattering diffraction particle size distribution measuring device. The silica filler used as component (E) may be used singly or in combination of two or more.

The method of surface treatment of the silica filler using a silane coupling agent is not particularly limited, and examples include dry method and wet method.

In the dry method, the silica filler and an appropriate amount of silane coupling agent for the surface area of the silica filler are put into a stirring device and stirred under appropriate conditions. Alternatively, the silica filler is loaded into a stirring device in advance, and an appropriate amount of the silane coupling agent for the surface area of the silica filler is added by dripping or spraying as a stock solution or solution while stirring under appropriate conditions. By stirring, the silane coupling agent is uniformly attached to the surface of the silica filler, and surface treatment (by hydrolysis) is performed. An example of a stirring device is a Henschel mixer. It can be stirred by high-speed rotation. Mixer for mixing. However, the stirring device is not particularly limited.

In the wet method, a sufficient amount of silane coupling agent is dissolved in water or an organic solvent to prepare a surface treatment solution for the surface area of the silica filler to be surface treated. A silica filler is added to the surface treatment solution and stirred into a slurry to fully react between the silane coupling agent and the silica filler. Subsequently, the silica filler is separated from the surface treatment solution using filtration and/or centrifugal separation, and is heated and dried to perform surface treatment.

When a silicon oxide filler is contained as the component (E), the silicon oxide filler is preferably contained in an amount of 50 to 600 parts by mass, more preferably 100 to 500 parts by mass, based on 100 parts by mass of the total of the component (A) and the component (B). It is better to contain 200~400 parts by mass. These ranges are the mass range including surface treatment agents (such as silane coupling agents) when performing surface treatment of silica fillers.

The thermosetting resin composition of this embodiment may contain components other than the above-mentioned components (A) to (E) as necessary. Specific examples of these components include epoxy resin, hardeners for epoxy resins, other thermosetting resins, hardeners for other thermosetting resins, thermoplastic resins, antioxidants, defoaming agents, leveling agents, shakers, etc. Modifying agents, flame retardants, blue-inhibiting agents, adhesion preventing agents and dispersants, etc. The types and amounts of each ingredient (preparation agent) are as commonly used.

(Preparation of thermosetting resin composition)

The thermosetting resin composition of this embodiment can be produced by a conventional method.

For example, in the presence of a solvent, the above-mentioned component (A) ~ component (D) (when the thermosetting resin composition contains the above-mentioned component (E) and/or other arbitrary components, further including these arbitrary components) are stirred by heating Mixer dissolves and mixes. Alternatively, the above-mentioned components (A) to (D) may be dissolved in a specific solvent respectively in a desired content ratio, and these (in a thermosetting resin composition containing the above-mentioned component (E) and/or In the case of other optional ingredients, further including these optional ingredients) are put into the mixer in a specific amount, mixed and stirred. When a filler such as component (E) is contained, it is desirable to use a dispersing device.

The thermosetting resin composition of this embodiment has the following preferable characteristics.

The thermosetting resin composition of this embodiment has excellent electrical properties at high frequencies as a thermosetting product. Specifically, the dielectric constant (ε) of the thermosetting product of the thermosetting resin composition in the frequency range of 1 to 100 GHz is preferably 3.5 or less, more preferably 3.3 or less. Furthermore, the dielectric tangent (tanδ) in the frequency range of 1 to 100 GHz is preferably 0.004 or less, more preferably 0.003 or less.

By setting the dielectric constant (ε) and dielectric tangent (tanδ) in the frequency range from 1 to 100 GHz to the above ranges, the electrical signal loss in the high-frequency range can be reduced.

Furthermore, the thermosetting resin composition according to this embodiment has excellent electrical characteristics and moisture resistance reliability at high frequencies. Specifically, the change rate of the dielectric constant (ε) in the frequency range of 1 to 100 GHz after being left for 1000 hours under the conditions of 85°C/85%RH according to the procedure described in the examples below is preferably 5% or less. It is better to be less than 3%. In addition, the change rate (tanδ) of the dielectric tangent in the frequency range of 1 to 100 GHz is preferably 120% or less, The best is below 80%, and the better is below 60%.

Furthermore, in the thermosetting resin composition of this embodiment, the thermosetting product has sufficient adhesive strength. Specifically, the peeling strength (180 degree peeling) of the thermosetting product of the thermosetting resin composition to copper foil (glossy surface and roughened surface) measured in accordance with JIS K6854-2 is preferably 4 N/cm or more, more preferably It is above 6N/cm.

The heat-generating peak of the thermosetting resin composition of this embodiment when measured with a differential scanning calorimeter (DSC) is 190°C or less, which is lower than the 200°C DSC heat-generating peak of component (A) alone. Therefore, the thermosetting resin composition of this embodiment can be fully cured under the same specific curing conditions of 200° C. × 60 minutes as when component (C) is not added.

The film containing the thermosetting resin composition of this embodiment (hereinafter, described as "the film of this embodiment" in this specification) can be obtained by a conventional method. For example, the thermosetting resin composition of this embodiment is diluted with a solvent to an appropriate viscosity to obtain a coating liquid. The coating liquid is applied to at least one side of the support and dried. Thereby, the film of this embodiment can be provided as a film with a support or as a film peeled off from the support.

Examples of solvents that can be used as the coating liquid include ketones such as methyl ethyl ketone and methyl isobutyl ketone; aromatic solvents such as toluene and xylene; and cyclohexanone, dimethylformamide and 1 -High boiling point solvents such as methyl-2-pyrrolidone, etc. The amount of solvent used is not particularly limited as long as the coating liquid can be adjusted to an optimal viscosity. The preferred amount of solvent used is 20 to 70% by mass relative to the solid content.

The support can be appropriately selected according to the manufacturing method and purpose of the film, and is not particularly limited. Examples of the support include metal foils such as copper and aluminum, base materials made of resins such as polyimide, liquid crystal polymer, and PTFE, and carrier films of resins such as polyester and polyethylene.

The method of applying the coating liquid is not particularly limited. Examples of the coating method include a slot die method, a gravure method, a blade coater method, and the like. The coating method can be appropriately selected depending on the desired film thickness and the like.

The film thickness in this embodiment is appropriately designed based on characteristics such as substrate thickness, component thickness, and mechanical strength required for the application. The film thickness of this embodiment is generally 10~200 μm.

The drying conditions are appropriately set according to the type and amount of the solvent used in the coating liquid, the coating thickness of the coating liquid, the difference in drying equipment, etc., and are not particularly limited. For example, drying can be performed at a temperature of 60 to 150°C and under atmospheric pressure.

The film of this embodiment is used as an electrical appliance. When bonding films for electronic applications, the usage sequence is as follows.

The film of this embodiment is placed on the bonded surface of one of the objects to be bonded using the film of this embodiment. Then, another object is placed so that its adhered surface is in contact with the exposed surface of the film. Here, when using a film with a support, the film is placed so that the exposed surface of the film contacts the adhered surface of another object. Then, the film is temporarily pressed on the surface to be bonded. Here, the temperature during temporary pressing can be set to 130°C, for example. During temporary pressing, the film is exposed by peeling off the support.

Next, place another object on the surface of the exposed film (insulating film) The object is placed in such a manner that the bonded surface is in contact with the exposed surface of the film. After these procedures are carried out, heat pressing is performed at a specific temperature and for a specific time, and then heat hardening is performed.

The temperature during hot pressing is preferably 100~160℃. The best hot pressing time is 0.5 to 3 minutes.

The temperature for heat hardening is preferably 160~240°C, more preferably 180~220°C. The preferred heating and hardening time is 30 to 120 minutes.

In addition, the temporary pressing step and the hot pressing step may be omitted.

In addition, instead of thinning in advance, the following procedure may be performed. That is, the thermosetting resin composition of this embodiment diluted with a solvent to an appropriate viscosity is applied to the bonded surface of an object to be bonded and dried. Then, the other object is placed on the dried thermosetting resin composition.

When the film of this embodiment is used as a cover film, the usage sequence is as follows.

The film of this embodiment is disposed at a specific position of the wiring-attached resin substrate on which the wiring pattern is formed on the main surface, that is, at a position covered by the cover film on the side where the wiring pattern is formed. Subsequently, temporary pressing, hot pressing and heat hardening are carried out at a specific temperature and for a specific time. In addition, the temporary pressing step and the hot pressing step may be omitted.

The temperature and time of temporary pressing, hot pressing and heat hardening are related to the use of the above as electrical. The same applies to films used in electronic applications.

The thermosetting resin composition of this embodiment and the cured product of the film of this embodiment can be used in flexible resin substrates including wiring patterns formed on the main surface due to their excellent high-frequency electrical characteristics. Distribution board.

The wiring-attached resin substrate includes a resin substrate such as a polyimide film and a liquid crystal polymer film, and a wiring pattern formed on the main surface of the resin substrate. The above-mentioned flexible wiring board is one in which the film of this embodiment is adhered to the wiring pattern side of the wiring-attached resin substrate through the above-mentioned procedures and cured.

Moreover, the flexible wiring board of this embodiment can be formed as follows. The thermosetting resin composition of this embodiment diluted with a solvent to have an appropriate viscosity is applied to the wiring pattern side of the above-mentioned resin substrate with wiring. Then, a layer made of a cured resin composition is formed on the wiring pattern.

The thin film of this embodiment can also be used for interlayer connection between substrates of a semiconductor device. In this case, the object to be bonded becomes a plurality of mutually laminated substrates constituting the semiconductor device. Furthermore, in the interlayer connection between substrates of a semiconductor device, the thermosetting resin composition of this embodiment diluted with a solvent to have an appropriate viscosity may be used instead of using one that has been thinned in advance.

The multilayer wiring board of this embodiment contains a cured product of the thermosetting resin composition of this embodiment or a cured product of the film of this embodiment. The multilayer wiring board of this embodiment can be produced by curing the thermosetting resin composition of this embodiment or the film of this embodiment. Since this multilayer wiring board contains the cured product of the thermosetting resin composition of this embodiment or the cured product of the film of this embodiment, it has excellent heat resistance, moisture resistance reliability, and moisture absorption reflow resistance. Examples of multilayer wiring boards include substrates for microwave and ultra-high-frequency wave communications, especially printed wiring boards for high-frequency applications such as ultra-high-frequency wave radar substrates for vehicles. The manufacturing method of multilayer wiring board has not Special restrictions. As a manufacturing method of a multilayer wiring board, the same method as when manufacturing a printed wiring board using a general prepreg sheet can be used.

[Example]

This embodiment will be described in detail below through examples. However, this embodiment is not limited to this.

(Examples 1 to 9, Comparative Examples 1 to 4) Sample preparation and measurement methods

Each component was measured so that the mixing ratio (parts by mass) would be as shown in the table below. Subsequently, component (A) and component (B) were added to a heating mixer in which a specific amount of toluene had been previously added. While heating to 70° C. and rotating the stirring blade at 35 rpm, the mixture was dissolved and mixed at normal pressure for 2 hours. Subsequently, after cooling to normal temperature, the other components were put into a heating mixer and stirred and mixed for 1 hour while rotating the stirring blade at 60 rpm. Subsequently, a specific amount of toluene is further added and stirred to dilute the resin composition in such a manner that it has a viscosity suitable for coating. Subsequently, the resin composition was dispersed using a wet micronization device (Nanomizer MN2-2000AR, manufactured by Yoshida Machinery Co., Ltd.).

The coating liquid containing the resin composition obtained in this way was applied to one side of the support (PET film subjected to release treatment) and dried at 100°C. Thereby, a thin film (thickness: 100 μm) with a support was obtained.

In addition, the codes in the table are expressed as follows.

Ingredient(A)

(A1): OPE-2St 2200 (brand name, manufactured by Mitsubishi Gas Chemical Co., Ltd.), oligophenylene ether (modified polyphenylene ether represented by the above general formula (1) (-(O-X-O)- in the formula (1)) is the general formula (5), and -(Y-O)- in the formula (1) is the formula (8)) (Mn=2200)

Ingredient(B)

(B1): Styrene-ethylene-butylene-styrene block copolymer (SEBS), G1652 (product name, manufactured by CLAYTON POLYMER JAPAN Co., Ltd.)

Ingredients(C)

(C1): Bis(triethoxysilylpropyl)tetrasulfide, KBE846 (product name, manufactured by Shin-Etsu Chemical Co., Ltd.)

Ingredients(D)

(D1): Dicumyl peroxide, PERCUMYL D (brand name, manufactured by NOF Co., Ltd.)

(D’1): tert-butyl peroxybenzoate, PERBUTYL Z (brand name, manufactured by NOF Co., Ltd.)

Ingredients(E)

(E1): Untreated spherical silica, FB-3SDX (product name, manufactured by DENKA Co., Ltd., average particle size 3.4 μm)

(E2): FB-3SDX surface-treated with 7-octenyltrimethoxysilane (product name: KBM-1083, silane coupling agent manufactured by Shin-Etsu Chemical Co., Ltd.)

(E3): FB-3SDX surface-treated with 8-methacrylyloxyoctenyltrimethoxysilane (product name: KBM-5803, silane coupling agent manufactured by Shin-Etsu Chemical Co., Ltd.)

(E4): FB-3SDX surface-treated with 3-methacryloxypropyltrimethoxysilane (product name: KBM-503, silane coupling agent manufactured by Shin-Etsu Chemical Co., Ltd.)

In addition, the surface treatment of (E2) to (E4) is performed by the dry method described in the above paragraph [0045]. At this time, the amount of silane coupling agent added is calculated from the minimum coverage area per 1g of silane coupling agent (m ² /g) and the specific surface area of silica filler (m ² /g), based on the following calculation formula, calculated Determined by the amount of coating on the surface of the silica filler.

Silane coupling agent addition amount (g) = (mass of silica filler (g) × specific surface area (m ² /g))/minimum coverage area of silane coupling agent (m ² /g)

DSC peak temperature: Set the test piece to the measuring device using a differential scanning calorimeter (DSC, NETZSCH DSC204 F1 Phoenix). Based on the DSC curve obtained from a specific temperature process (heating from 25°C to 300°C at 5°C/min), the heat peak value is read. Set the peak temperature to the DSC peak temperature.

Dielectric permittivity (ε), dielectric tangent (tanδ): The film was heated and hardened at 200° C. for 60 minutes, and then peeled off from the support. Then, a test piece (50±1mm×70±12mm) was cut out from the film, and the thickness of the test piece was measured. The resonator method (SPDR method) (10GHz) measures the dielectric constant (ε) and dielectric tangent (tanδ) of the test piece.

Moisture resistance reliability: Place the above test piece under the conditions of 85℃/85%RH for 1000 hours. Subsequently, in the same procedure as above, the dielectric constant (ε) and dielectric tangent (tanδ) of the test piece were measured.

Peel strength: Laminate copper foil (CF-T9FZSV, manufactured by Fukuda Metal Foil Industry Co., Ltd., thickness 18 μm) on both sides of the film, and press and harden with a press (200°C, 60 minutes, 10kgf). The test piece was cut out with a width of 10 mm and peeled off using Autograph. In accordance with JIS K 6854-2, the peel strength of the test piece (180-degree peel) was measured. The peel strength was measured when the glossy surface of the copper foil was bonded to the inside and the peel strength when the roughened surface was bonded.

Examples 1 to 9 were all excellent in both dielectric properties (dielectric constant (ε), dielectric tangent (tanδ)) (initial value) and peeling strength to copper foil. Moreover, the DSC peak temperatures are all below 190°C. Furthermore, Example 1 and Examples 7 to 9 were also excellent in moisture resistance.

In addition, Example 2 is an example in which the mixing ratio of components (A1) and (B1) is changed compared to Example 1. Examples 3 to 5 are examples in which the proportion of component (C1) is changed compared to Example 2. Example 6 is an example in which the proportions of components (A1), (B1) and (D1) are changed compared to Example 1. Examples 7 to 9 are examples in which the component (E2) is changed into the component (E3), (E4), or (E1), respectively, relative to Example 1. Compared with Example 9 using untreated silica oxide filler (E1), the resistance of Examples 1, 7 and 8 using silica oxide filler (E2), (E3) and (E4) surface-treated with silane coupling agent. Moisture dependence is further improved.

In Comparative Examples 1 and 2, instead of dialkyl peroxide-based radical polymerization The component (D1) of the initiator is used, and the component (D'1) of the alkyl peroxide-based radical polymerization initiator is used. In Comparative Examples 1 and 2, the DSC peak temperature was 230°C or higher.

In Comparative Example 3 without using component (C1), the DSC peak temperature was 190°C or lower. However, the peel strength with respect to copper foil tends to be low, and the peel strength with respect to the glossy surface is 4 N/cm or less, which is particularly low.

Comparative Example 4 in which component (C1) was not used but (D1) (dicumyl peroxide) was used, the DSC peak temperature was 190°C or lower. However, the peel strength with respect to copper foil tends to be low, and the peel strength with respect to the glossy surface is 4 N/cm or less, which is particularly low.

Claims (11)

A thermosetting resin composition characterized by containing (A) a thermosetting resin having a styrene group at the end and a phenylene ether skeleton, (B) a styrene-based thermoplastic elastomer, and (C) a thioether-based silane Coupling agent, and (D) dialkyl peroxide radical polymerization initiator; and the thermosetting resin composition does not contain a phosphorus-nitrogen flame retardant and a second flame retardant with a Curie temperature of -50°C or less. Metal oxides from Groups 2 to 6 and salts of metal oxides from Groups 2 to 6; with respect to the aforementioned (A), a thermosetting resin having a styrene group at the end and a phenylene ether skeleton and the aforementioned (A) B) A total of 100 parts by mass of the styrene-based thermoplastic elastomer, the content of the aforementioned (C) thioether-based silane coupling agent is 0.1 to 5.0 parts by mass, and the content of the aforementioned (A) has a styrene group at the end and a phenylene glycol The total amount of the thermosetting resin of the skeleton and the aforementioned (B) styrenic thermoplastic elastomer is 100 parts by mass, and the content of the aforementioned (D) dialkyl peroxide-based radical polymerization initiator is 0.1 to 5.0 parts by mass. The thermosetting resin composition of claim 1, wherein the thermosetting resin of the component (A) has a number average molecular weight (Mn) of 1,000 to 5,000. The thermosetting resin composition of claim 1 or 2, wherein the aforementioned components The styrenic thermoplastic elastomer system of (B) is hydrogenated. The thermosetting resin composition of claim 1 or 2, wherein the aforementioned component (C) thioether-based silane coupling agent is a polythioether-based silane coupling agent. The thermosetting resin composition of claim 1 or 2 further contains (E) silica filler. The thermosetting resin composition of claim 5, wherein the silica filler of component (E) is surface-treated with a silane coupling agent. A resin film containing the thermosetting resin composition according to any one of claims 1 to 6. A cured product of the thermosetting resin composition according to any one of claims 1 to 6. A cured product of the resin film according to claim 7. A multilayer wiring board containing a cured product of the thermosetting resin composition according to claim 8. A multilayer wiring board including a cured product of the resin film according to claim 9.