Resin composition, production method therefor, adhesive film, and bonding sheet for interlaminar bonding

Abstract

Provided is a resin composition for adhesive films which has a low dielectric loss and nevertheless attains a sufficient adhesion strength and which can give adhesive films inhibited from suffering resin flow. The resin composition comprises (A) a styrene / butadiene / butylene / styrene block copolymer, (B) an epoxy resin, and (C) a thermosetting resin which is not an epoxy resin, wherein the (A) component has a styrene content of 31-60%.

Description

Resin composition, its manufacturing method, and adhesive film and bonding sheet for bonding layers

[0001] The present invention relates to a resin composition and a method for producing the same, as well as an adhesive film and a bonding sheet for bonding between layers.

[0002] In recent years, technological innovations toward high-speed, large-capacity communications have been progressing in the field of information and communications, and the use of high-frequency ranges that enable large-capacity communications has been increasing. However, high-frequency signals tend to attenuate easily, and there is a demand for antennas and their surrounding flexible printed circuits (hereinafter also referred to as "FPCs") and high-frequency cables (hereinafter also referred to as "RF cables") to be designed with less loss in the high-frequency range. Note that "FPC" is an abbreviation for "Flexible Printed Circuits." Furthermore, "RF" is an abbreviation for "Radio Frequency."

[0003] There is a demand for materials with lower dielectric properties for the core materials used in FPCs, and the use of liquid crystal polymers (hereinafter also referred to as "LCPs"), which have lower dielectric properties and better moisture resistance than conventional polyimides (PIs), is increasing. "LCP" is an abbreviation for "Liquid Crystal Polymer."

[0004] As materials for FPCs and RF cables, for example, thermosetting resin compositions using specific vinyl compounds and rubber or thermoplastic elastomers, and uncured films made from the same have been proposed (see, for example, Patent Document 1). The technology described in Patent Document 1 aims to achieve low elasticity and low dielectric constant and low dielectric loss tangent in the high frequency range.

[0005] International Publication No. 2008 / 018483

[0006] Currently, FPCs laminated with LCP are in practical use, but bonding LCPs sometimes requires pressing at high temperatures, and research is underway into a method of bonding LCPs with a low-dielectric bonding sheet (e.g., uncured film) that can be pressed at low temperatures.

[0007] The technology described in Patent Document 1 aims to achieve low elasticity and low dielectric constant and low dielectric loss tangent in the high frequency range as described above, but does not take into consideration the resin flow (e.g., fluidity) of the film. Hereinafter, the resin flow (fluidity) of the film as described above may be referred to as "resin flow."

[0008] Conventionally, films with high resin flow have been used for FPCs, taking into consideration, for example, the embeddability of wiring. Meanwhile, in recent years, in the manufacture of high-frequency boards and other multilayer boards, boards with holes drilled and multilayered structures have been used. When a film with high fluidity is used in such boards with holes drilled and multilayered structures, the film can clog the holes in the board, causing defects. Therefore, it is necessary to suppress resin flow in multilayer boards that undergo press curing after drilling, and the development of a film that can suppress resin flow has been eagerly awaited.

[0009] In addition, in the field of electrical and electronic equipment, dielectric properties such as low dielectric constant and low dielectric loss tangent are required in anticipation of use in high frequency regions. Furthermore, as a bonding sheet for multilayer substrates, high adhesiveness to components such as LCP is also required. The material described in the above-mentioned Patent Document 1 has room for improvement in terms of the above-mentioned dielectric loss tangent and adhesive strength to LCP.

[0010] The present invention has been made in view of the problems of the prior art, and provides a resin composition for an adhesive film that has low dielectric loss while providing sufficient adhesive strength and is capable of suppressing resin flow in the adhesive film, a method for producing the same, and an adhesive film and a bonding sheet for bonding between layers.

[0011] According to the present invention, there are provided a resin composition and a method for producing the same, as well as an adhesive film and a bonding sheet for bonding between layers, as shown below.

[0012] [1] A resin composition comprising: (A) a styrene / butadiene / butylene / styrene block copolymer; (B) an epoxy resin; and (C) a thermosetting resin other than an epoxy resin, wherein the styrene ratio of the component (A) is 31 to 60%.

[0013] [2] The resin composition according to [1], wherein the component (A) comprises: (A1) a first styrene / butadiene / butylene / styrene block copolymer having a styrene ratio of 40% or more; and (A2) a second styrene / butadiene / butylene / styrene block copolymer having a styrene ratio of less than 40%.

[0014] [3] The resin composition according to [1] or [2], wherein the component (C) is a terminal-modified polyphenylene ether resin.

[0015] [4] The resin composition according to any one of [1] to [3], wherein the component (C) is a modified polyphenylene ether resin having a terminal carbon-carbon double bond.

[0016] [5] The resin composition according to any one of [1] to [4], wherein the content ratio of the (C) component to the (A) component is, in mass ratio, (C) component:(A) component=10:90 to 40:60.

[0017] [6] The resin composition according to any one of [1] to [5], wherein the (B) component is contained in an amount of 0.1 to 3% by mass relative to 100% by mass of the resin components in the resin composition.

[0018] [7] The resin composition according to any one of [1] to [6] above, further comprising (D) a curing catalyst.

[0019] [8] The resin composition according to any one of [1] to [7] above, further comprising (E) an organic peroxide.

[0020] [9] An adhesive film using the resin composition according to any one of [1] to [8].

[0021]

[10] A bonding sheet for interlayer bonding using the resin composition according to any one of [1] to [8] above.

[0022]

[11] A cured product made of the resin composition according to any one of [1] to [8].

[0023]

[12] A cured product comprising the adhesive film according to [9] above.

[0024]

[13] A laminate in which a member containing a liquid crystal polymer is laminated using the interlayer bonding bonding sheet described in

[10] .

[0025]

[14] A cured product comprising the laminate according to

[13] above.

[0026]

[15] A laminate using the resin composition according to any one of [1] to [8].

[0027]

[16] A semiconductor device using the resin composition according to any one of [1] to [8].

[0028]

[17] A method for producing a resin composition, comprising the step of mixing (A) a styrene / butadiene / butylene / styrene block copolymer, (B) an epoxy resin, and (C) a thermosetting resin other than an epoxy resin, wherein at least (A1) a first styrene / butadiene / butylene / styrene block copolymer having a styrene ratio of 40% or more and (A2) a second styrene / butadiene / butylene / styrene block copolymer having a styrene ratio of 40% or less are used as the component (A), and the blending ratio of the component (A1) and the component (A2) is adjusted so that the styrene ratio of the component (A) is 31 to 60%.

[0029] The resin composition of the present invention can be suitably used as a resin composition for adhesive films, and in particular, has the effect of obtaining sufficient adhesive strength while having low dielectric loss, and being able to suppress resin flow in adhesive films. In particular, when the resin composition of the present invention is used as a bonding sheet for multilayer substrates, it can suppress resin flow in perforated areas when the substrate is multilayered. Furthermore, the method for producing the resin composition of the present invention can easily produce the above-mentioned resin composition.

[0030] In addition, the adhesive film and interlayer bonding sheet of the present invention use the above-mentioned resin composition, and have sufficient adhesive strength while having low dielectric loss, and in particular have the effect of being able to suppress resin flow in the drilled areas when the substrate is multilayered.

[0031] 1 is a schematic diagram for explaining a method for measuring a flow amount, FIG. 2 is a schematic diagram for explaining a method for measuring a flow amount, FIG. 3 is a schematic diagram for explaining a method for measuring a flow amount, FIG.

[0032] While the present invention will be described below with reference to exemplary embodiments, it should be understood that the present invention is not limited to the following exemplary embodiments. Therefore, it should be understood that modifications and improvements to the following exemplary embodiments, based on the ordinary knowledge of those skilled in the art, are also within the scope of the present invention, provided that they do not deviate from the spirit of the present invention.

[0033] (1) Resin Composition: One embodiment of the resin composition of the present invention is a resin composition containing (A) a styrene / butadiene / butylene / styrene block copolymer (hereinafter also referred to as "component (A)"), (B) an epoxy resin (hereinafter also referred to as "component (B)"), and (C) a thermosetting resin other than an epoxy resin (hereinafter also referred to as "component (C)"). In the resin composition of this embodiment, the styrene ratio of component (A) is 31 to 60%. A resin composition configured as described above can be suitably used as a resin composition for adhesive films, and in particular, it can obtain sufficient adhesive strength while exhibiting low dielectric loss, and can suppress resin flow in drilled areas when a substrate is multilayered.

[0034] The resin composition of the present embodiment may contain, in addition to the above-described components (A), (B), and (C), other components such as (D) a curing catalyst and (E) an organic peroxide.

[0035] (Component (A)) Component (A) is a styrene / butadiene / butylene / styrene block copolymer having a styrene ratio of 31 to 60%. Hereinafter, styrene / butadiene / butylene / styrene block copolymer may be referred to as "SBBS."

[0036] The styrene / butadiene / butylene / styrene block copolymer (SBBS) as component (A) is a hydrogenated styrene-based thermoplastic elastomer obtained by highly selectively hydrogenating the 1,2-bonds in the polybutadiene block of a styrene / butadiene / styrene block copolymer (hereinafter also referred to as "SBS"). By including SBBS as component (A), solder heat resistance and dielectric properties can be improved. The presence or absence of component (A) in the resin composition can be detected by a method such as Fourier transform infrared spectroscopy (FTIR).

[0037] In this embodiment, the styrene / butadiene / butylene / styrene block copolymer as component (A) does not include a styrene / ethylene / butylene / styrene block copolymer (hereinafter also referred to as "SEBS") in which all double bonds in the polybutadiene block are hydrogenated. Hereinafter, a styrene-based thermoplastic elastomer in which all double bonds are hydrogenated will be referred to as a "hydrogenated styrene-based thermoplastic elastomer," and a hydrogenated styrene-based thermoplastic elastomer in which some double bonds, such as component (A), are selectively hydrogenated will be referred to as a "partially hydrogenated styrene-based thermoplastic elastomer." Furthermore, a styrene-based thermoplastic elastomer that has not been hydrogenated, such as a styrene / butadiene / styrene block copolymer (hereinafter also referred to as "SBS"), will be referred to as a "non-hydrogenated styrene-based thermoplastic elastomer."

[0038] The (A) component used in the resin composition of this embodiment has a particularly important configuration in that its styrene ratio is 31 to 60%. A styrene ratio of 31 to 60% in the (A) component minimizes resin flow and achieves sufficient adhesive strength to LCP. For example, if the (A) component's styrene ratio is less than 31%, the adhesive strength is strong, but the resin flow control is insufficient. On the other hand, as the (A) component's styrene ratio increases, resin flow can be suppressed but the adhesive strength weakens. If the styrene ratio exceeds 60%, it becomes difficult to form the resin composition into a film. While not particularly limited, in order to minimize resin flow and achieve sufficient adhesive strength to LCP, the (A) component's styrene ratio is preferably 32 to 52%, and more preferably 33 to 46%.

[0039] Here, the "styrene ratio" refers to the percentage (%) of the ratio of the content of the styrene component to the total mass of the styrene-based thermoplastic elastomer. For example, the styrene ratio is measured using nuclear magnetic resonance (NMR). Specifically, using tetrachloroethane as a solvent, the integral value of the peak in the range of 5.5 ppm to 6.5 ppm, which corresponds to styrene, and the integral value of the peaks in the other ranges are determined, and the styrene ratio is calculated from the obtained values.

[0040] When component (A) consists of one type of SBBS, the styrene ratio of that SBBS is the "styrene ratio of component (A)." When component (A) is a mixture of two or more types of SBBS with different styrene ratios, the weighted average of the styrene ratios of those SBBS is the "styrene ratio of component (A)." In this way, when component (A) is a mixture of two or more types of SBBS with different styrene ratios, the styrene ratio of component (A) is sometimes referred to as the "average styrene ratio."

[0041] For example, when component (A) is composed of two types of SBBS with different styrene ratios, the average styrene ratio (%) of component (A) can be calculated based on the following formula (1). Here, one of the two types of SBBS is designated as "SBBS (1)" and the other is designated as "SBBS (2)". In addition, in formula (1), "X （１） " indicates the mass ratio (mass%) of SBBS (1) in component (A), and "X （２） " indicates the mass ratio (mass%) of SBBS (2) in component (A). （１） " indicates the styrene ratio (%) of SBBS (1), and "ST （２） " indicates the styrene ratio (%) of SBBS (2).

[0042]

[0043] For example, suppose the styrene ratio of SBBS (1) is 20% and the styrene ratio of SBBS (2) is 40%. If the mass ratio of SBBS (1) in component (A) is 10% by mass and the mass ratio of SBBS (2) is 90% by mass, the average styrene ratio can be calculated using the formula shown in Equation (2) below. That is, the average styrene ratio of such component (A) is 38%. When component (A) is a mixture of three or more different SBBSs, the weighted average value of the styrene ratios of the three or more SBBSs can be calculated following the formula (1) above.

[0044]

[0045] When component (A) is a mixture of two or more SBBSs with different styrene ratios, resin flow can be appropriately controlled and sufficient adhesive strength to LCP can be obtained. For example, component (A) is preferably configured as follows. Component (A) preferably contains (A1) a first styrene / butadiene / butylene / styrene block copolymer having a styrene ratio of 40% or more and (A2) a second styrene / butadiene / butylene / styrene block copolymer having a styrene ratio of less than 40%. The blending ratio (mass ratio) of the first styrene / butadiene / butylene / styrene block copolymer (A1) to the second styrene / butadiene / butylene / styrene block copolymer (A2) is not particularly limited, as long as the average styrene ratio of component (A) containing both is within the numerical range of 31 to 60%.

[0046] Component (A) has good compatibility with components (B) and (C) and good film-forming ability, and can produce a cured product with excellent balance of strength. Therefore, the weight-average molecular weight is preferably 30,000 to 300,000, more preferably 40,000 to 100,000, and even more preferably 50,000 to 80,000. The weight-average molecular weight is determined by gel permeation chromatography (GPC) using a calibration curve based on standard polystyrene. Component (A) may also be a reactive elastomer to which a functional group such as an amine has been added. Using a reactive elastomer to which a functional group has been added can further improve adhesive strength (peel strength).

[0047] There are no particular restrictions on the content of component (A). However, the content ratio of component (C) to component (A) is preferably component (C):component (A) = 10:90 to 40:60 by mass, and more preferably 15:85 to 35:65 by mass. In the above-mentioned content ratio of component (C) to component (A), if the content of component (C) is too low (in other words, if the content of component (A) is too high), the amount of curable component decreases, which is undesirable in that the flow amount increases. On the other hand, in the above-mentioned content ratio of component (C) to component (A), if the content of component (C) is too high (in other words, if the content of component (A) is too low), the amount of curable component increases, which is undesirable in that the cured film becomes hard and the adhesiveness decreases.

[0048] The content of component (A) is preferably 60 to 83 mass %, and more preferably 65 to 72 mass %, relative to 100 mass % of the resin components in the resin composition.

[0049] A specific example of component (A) is a product manufactured by Asahi Kasei Chemicals Corp. under the trade name "P5051." Alternatively, two or more products manufactured by Asahi Kasei Chemicals Corp. under the trade names "P1083," "P1500," "P5051," and "P2000" may be blended together to provide an average styrene ratio of 31 to 60%.

[0050] (Component (B)) Component (B) is an epoxy resin. Examples of epoxy resins of component (B) include bisphenol A type epoxy resins, bisphenol F type epoxy resins, phenol novolac type epoxy resins, alicyclic epoxy resins, siloxane type epoxy resins, biphenyl type epoxy resins, glycidyl ester type epoxy resins, glycidyl amine type epoxy resins, hydantoin type epoxy resins, and naphthalene ring-containing epoxy resins. In the epoxy resin composition, the compounds exemplified here may be used alone or in combination of two or more. Note that the epoxy resin as component (B) is preferably a solid epoxy resin from the viewpoint of suppressing resin flow. Furthermore, it is preferable that the epoxy resin of component (B) is an epoxy resin having a naphthalene skeleton, as this improves the adhesiveness of a film formed using the resin composition.

[0051] There are no particular restrictions on the content of component (B). However, component (B) is preferably contained in an amount of 0.1 to 3 mass% relative to 100 mass% of the resin components in the resin composition, and more preferably 0.5 to 1.5 mass%. By including an epoxy resin as component (B), it is possible to improve adhesive strength. For example, if component (B) is less than 0.1 mass%, it may be difficult to obtain the desired adhesive strength. On the other hand, if the amount of component (B) is too large, the dielectric properties may deteriorate.

[0052] Specific examples of the component (B) include bisphenol A type epoxy resin manufactured by Mitsubishi Chemical Corporation under the trade name "828EL" and epoxy resin manufactured by Nippon Kayaku Co., Ltd. under the trade name "502H".

[0053] (Component (C)) Component (C) is a thermosetting resin other than an epoxy resin. Any thermosetting resin can be selected as the thermosetting resin other than an epoxy resin, but a thermosetting resin with a low dielectric constant and dielectric dissipation factor is preferred. More specifically, a thermosetting resin with a dielectric constant of preferably 3.0 or less, more preferably 2.5 or less in a frequency range of 10 GHz, or a dielectric dissipation factor of 0.004 or less, more preferably 0.003 or less in a frequency range of 10 GHz is preferred. From this perspective, a suitable example of a thermosetting resin other than an epoxy resin as component (C) is a terminal-modified polyphenylene ether resin.

[0054] Furthermore, among the above-mentioned terminally modified polyphenylene ether resins, modified polyphenylene ether resins having terminal carbon-carbon double bonds are more preferred, as they have relatively low polarity and can achieve low dielectric loss tangents.

[0055] The thermosetting resin other than the epoxy resin as component (C) preferably has a number average molecular weight of 1,000 or more, and more preferably 2,000 or more from the viewpoint of suppressing resin flow.

[0056] (Component (D)) Component (D) is a curing catalyst. Component (D) is a component that assists in the curing of an adhesive film or interlayer bonding sheet formed using the resin composition of this embodiment. In particular, component (D) is preferably a catalyst that accelerates the curing reaction of the epoxy resin of component (B).

[0057] Examples of the curing catalyst as component (D) include imidazole-based curing catalysts, amine-based curing catalysts, and phosphorus-based curing catalysts. Examples of imidazole-based curing catalysts include imidazole compounds such as 2-methylimidazole, 2-undecylimidazole, 1-cyanoethyl-2-undecylimidazole, 2-heptadecylimidazole, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-ethyl-4-imidazole, 2-phenylimidazole, 1-benzyl-2-phenylimidazole, and 2-phenyl-4-methylimidazole. Of these, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-undecylimidazole, and 1-cyanoethyl-2-ethyl-4-imidazole are preferred. Examples of amine-based curing catalysts include triazine compounds such as 2,4-diamino-6-[2'-methylimidazolyl-(1')]ethyl-s-triazine, and tertiary amine compounds such as 1,8-diazabicyclo[5,4,0]undecene-7 (DBU), triethylenediamine, benzyldimethylamine, and triethanolamine. Among these, 2,4-diamino-6-[2'-methylimidazolyl-(1')]ethyl-s-triazine is preferred. Examples of phosphorus-based curing catalysts include triphenylphosphine, tributylphosphine, tri(p-methylphenyl)phosphine, and tri(nonylphenyl)phosphine. Among these, imidazole-based curing catalysts are preferred because they can be adjusted to achieve appropriate curability. Furthermore, imidazole-based curing catalysts having a benzene ring are more preferred because they can increase the adhesive strength over time of uncured films formed using the resin composition of this embodiment. Examples of such imidazole-based curing catalysts include 2-phenylimidazole, 1-benzyl-2-phenylimidazole, and 2-phenyl-4-methylimidazole, with 1-benzyl-2-phenylimidazole being particularly preferred.

[0058] The content of component (D) can be appropriately selected depending on the type of curing catalyst used as component (D). When an imidazole curing catalyst is used as component (D), the content is preferably 0.01 to 20 parts by mass, more preferably 0.1 to 15 parts by mass, and even more preferably 1 to 10 parts by mass, per 100 parts by mass of the epoxy resin of component (B). If the content of component (D) is too low, curability may deteriorate. On the other hand, if the content of component (D) is too high, the shelf life of the adhesive film may deteriorate.

[0059] (Component (E)) Component (E) is an organic peroxide. Examples of the organic peroxide for component (E) include t-butyl peroxybenzoate, t-butylperoxyisopropyl carbonate, t-butylperoxy-2-ethylhexyl carbonate, t-butylperoxyacetate, dicumyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, di-t-butyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexyne-3, and 1,1-di(t-butylperoxy)-3,3 ,5-trimethylcyclohexane, 1,1-di(t-butylperoxy)cyclohexane, methyl ethyl ketone peroxide, 2,5-dimethylhexyl-2,5-diperoxybenzoate, t-butyl hydroperoxide, p-menthane hydroperoxide, benzoyl peroxide, p-chlorobenzoyl peroxide, t-butylperoxyisobutyrate, hydroxyheptyl peroxide, dicyclohexanone peroxide, and the like.

[0060] Addition of the organic peroxide component (E) can accelerate the curing reaction of component (C), such as a terminally modified polyphenylene ether resin, and stabilize the reactivity. Considering that the resin composition of this embodiment is used in the form of a film, it is preferable that component (E) is not activated in the temperature range of 60 to 120°C used in the drying step of film formation, but is activated in a higher temperature range. An example of such component (E) is t-butyl peroxybenzoate.

[0061] (Other Compounding Agents) The resin composition of this embodiment may further contain components other than the components (A) to (E) described above, as necessary. Specific examples of such components include silane coupling agents, antifoaming agents, flow control agents, film-forming aids, dispersants, and inorganic particles. The types and amounts of each compounding agent are the same as in conventional methods.

[0062] On the other hand, it is preferable that the adhesive film formed using the resin composition of this embodiment does not contain any components that adversely affect the high-frequency characteristics of the adhesive film, such as liquid rubber and flame retardants.

[0063] (Characteristics of Resin Composition) The resin composition of this embodiment preferably has, for example, the following characteristics. It is preferable that the cured product (e.g., a thermoset product) of the resin composition of this embodiment has excellent electrical properties at high frequencies. Specifically, the cured product of the resin composition preferably has a dielectric constant (ε) of 2.5 or less, more preferably 2.4 or less, in the frequency range of 1 to 10 GHz. Furthermore, the dielectric loss tangent (tan δ) in the frequency range of 1 to 10 GHz is more preferably 0.0025 or less, more preferably 0.0022 or less. By having the dielectric constant (ε) and dielectric loss tangent (tan δ) in the frequency range of 1 to 10 GHz in the above ranges, electrical signal loss in the frequency range of 1 to 10 GHz can be reduced.

[0064] The resin composition of this embodiment preferably has sufficient adhesive strength when cured. Specifically, the cured resin composition preferably has a peel strength (180-degree peel) of 4 N / cm or more against a roughened copper foil surface measured in accordance with JIS K6854-2. The cured resin composition preferably has a peel strength (90-degree peel) of 3 N / cm or more against a liquid crystal polymer film measured in accordance with JIS K6854-1.

[0065] (Method for Producing Resin Composition) The resin composition of this embodiment can be produced by a conventional method. For example, first, components (A) to (C) are mixed in the presence of a solvent to obtain a mixture. When producing the resin composition of this embodiment, a styrene / butadiene / butylene / styrene block copolymer having a styrene ratio of 31 to 60% is used as component (A). The epoxy resin described above is used as component (B), and a thermosetting resin other than the epoxy resin described above is used as component (C). If optional components other than components (A) to (C) are to be added to the resin composition, these optional components may be added to the mixture according to a conventional method. Components (A) to (C) can be mixed, for example, using a heated mixing kneader. Mixing conditions are not particularly limited, and examples include a rotation speed of 100 to 1000 rpm, 80°C, and 3 hours.

[0066] When producing the resin composition of this embodiment, it is preferable to use at least (A1) a first styrene / butadiene / butylene / styrene block copolymer having a styrene ratio of 40% or more and (A2) a second styrene / butadiene / butylene / styrene block copolymer having a styrene ratio of less than 40% as component (A), and to adjust the blending ratio of components (A1) and (A2) as described above so that the average styrene ratio of component (A) is 31 to 60%. By configuring in this manner, the styrene ratio (average styrene ratio) of component (A) can be adjusted to a desired value. For example, while commercially available styrene / butadiene / butylene / styrene block copolymers can be used as component (A), the styrene ratio of commercially available products is determined by the specifications of the thermoplastic elastomer, making it difficult to adjust the styrene ratio of such styrene / butadiene / butylene / styrene block copolymers to a desired value. For this reason, by using the method described above, i.e., by mixing component (A1) having a styrene ratio of 40% or more with component (A2) having a styrene ratio of less than 40%, it becomes possible to finely adjust the styrene ratio of component (A).

[0067] Next, the resulting mixture is cooled, and then the components (D) and (E) are further added as needed, followed by stirring at room temperature for, for example, 30 to 60 minutes. In this manner, the resin composition of the present embodiment can be produced.

[0068] (2) Adhesive Film and Bonding Sheet for Indirect Bonding of Layers: Next, embodiments of the adhesive film and bonding sheet for indirect bonding of layers of the present invention will be described. The adhesive film of this embodiment is an adhesive film using the resin composition of this embodiment described above. The adhesive film of this embodiment has low dielectric loss yet sufficient adhesive strength, and can particularly suppress resin flow at perforated areas when the substrate is multilayered. The adhesive film of this embodiment can be obtained from the resin composition of this embodiment by a known method. For example, the resin composition of this embodiment can be diluted with a solvent to form a varnish, which can be applied to at least one side of a support and dried, and then provided as a film with a support or a film peeled from the support.

[0069] Examples of solvents that can be used for the varnish include ketones such as methyl ethyl ketone and methyl isobutyl ketone; aromatic solvents such as toluene and xylene; and high-boiling point solvents such as dioctyl phthalate and dibutyl phthalate. The amount of solvent used is not particularly limited and can be an amount that has been conventionally used, but is preferably 20 to 90% by mass based on the solid content.

[0070] The support is appropriately selected depending on the desired form in the method for producing the adhesive film, and is not particularly limited, but examples thereof include metal foils such as copper and aluminum, and carrier films of resins such as polyester and polyethylene. When the adhesive film is provided in the form of an adhesive film peeled from a support, the support is preferably subjected to a release treatment with a silicone compound or the like.

[0071] The method of applying the varnish is not particularly limited, but examples thereof include a slot die method, a gravure method, a doctor coater method, etc., and is appropriately selected depending on the desired film thickness, etc., but the gravure method is particularly preferred because it can design a thin film. The application is performed so that the thickness of the film formed after drying is the desired thickness. Those skilled in the art can derive such thickness from the solvent content.

[0072] The thickness of the adhesive film is appropriately designed based on the properties required for the application, such as mechanical strength, but is generally 1 to 100 μm, and when a thinner film is required, it is preferably 1 to 30 μm.

[0073] The drying conditions are appropriately designed depending on the type and amount of solvent used in the varnish, the amount of varnish used, the thickness of the coating, etc., and are not particularly limited, but can be, for example, 60 to 100°C and can be carried out under atmospheric pressure.

[0074] The bonding sheet for bonding between layers of this embodiment is also a bonding sheet for bonding between layers for multilayer substrates using the resin composition of this embodiment, similar to the adhesive film described above. Therefore, sufficient adhesive strength can be obtained while maintaining low dielectric loss, and resin flow at perforated areas can be suppressed particularly when the substrate is multilayered.

[0075] When the adhesive film of this embodiment is used as an adhesive film for electrical and electronic applications, the procedure for use is as follows: First, place the adhesive film on the surface to be adhered of one of the objects to be adhered using the adhesive film of this embodiment, and then place the other object so that its surface to be adhered contacts the exposed surface of the adhesive film of this embodiment. When using the adhesive film of this embodiment with a support, place the adhesive film so that its exposed surface contacts the surface to be adhered of one of the objects, and then temporarily press the adhesive film onto the surface to be adhered. The temperature during temporary pressing can be, for example, 130°C.

[0076] Next, after the temporary bonding, the support is peeled off, and another object is placed on the exposed surface of the adhesive film so that its adherend surface is in contact with the exposed surface of the adhesive film. After performing these procedures, the object is thermocompressed at a predetermined temperature for a predetermined time, and then heated and cured. Note that the thermocompression bonding step may be omitted.

[0077] The temperature during thermocompression bonding is preferably 100 to 150°C. The time for thermocompression bonding is preferably 0.5 to 10 minutes. The temperature for heat curing is preferably 150 to 200°C. The time for heat curing is preferably 30 to 120 minutes. Instead of using a pre-formed film, a varnish prepared by diluting the resin composition of the present embodiment with a solvent may be applied to the adherend surface of one of the objects to be bonded, dried, and then the procedure of placing one of the objects described above may be carried out.

[0078] When the adhesive film of this embodiment is used as a coverlay film, the procedure for using it is as follows. The adhesive film of this embodiment is placed at a predetermined position on a wired resin substrate having a wiring pattern formed on its main surface, i.e., at the position to be covered by the adhesive film on the side on which the wiring pattern is formed, and then pre-pressed, thermocompressed, and heat-cured at a predetermined temperature for a predetermined time. The thermocompression bonding step may be omitted. The temperatures and times for pre-pressed, thermocompressed, and heat-cured are the same as those for use as an adhesive film for electrical and electronic applications described above.

[0079] The interlayer bonding sheet of this embodiment is suitable as an interlayer bonding sheet for multilayer substrates, and can be used, for example, for interlayer bonding between substrates of a semiconductor device. In this case, the objects to be bonded, as described above for the adhesive film, are the multiple substrates that constitute the semiconductor device, which are stacked together in multiple layers. Note that, for interlayer bonding between substrates of a semiconductor device, instead of using a pre-formed film, a varnish prepared by diluting the resin composition of this embodiment with a solvent may also be used.

[0080] The substrate constituting the semiconductor device is not particularly limited, and any of organic substrates such as epoxy resin, phenol resin, bismaleimide triazine resin, etc., and inorganic substrates such as CCL substrate, ceramic substrate, silicon substrate, etc., can be used. For example, a preferred example is a laminate in which members containing a liquid crystal polymer are laminated using the interlayer bonding bonding sheet of this embodiment.

[0081] The resin composition, adhesive film, and interlayer bonding sheet described above can also be provided as a cured product obtained by curing them. For example, a cured product of the resin composition of this embodiment, a cured product of the adhesive film of this embodiment, and a cured product of the interlayer bonding sheet can be provided. Furthermore, a cured product can be provided that is a laminate in which a member containing a liquid crystal polymer is laminated using the interlayer bonding sheet.

[0082] Furthermore, the present invention can provide a laminate using the resin composition described above and a semiconductor device using the resin composition. In particular, the resin composition of this embodiment has low dielectric loss and sufficient adhesive strength, and can suppress resin flow in drilled holes when the substrate is multilayered.

[0083] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. In the following examples, parts and % represent parts by mass and % by mass unless otherwise specified.

[0084] (Examples 1 to 14, Comparative Examples 1 to 5) [Sample Preparation] The components were weighed and mixed to the blending ratios (% by mass) shown in Tables 1 to 4 below, and then placed in a reaction vessel heated to 80°C. Mixing was carried out at normal pressure for 4 hours while rotating at 150 rpm. However, the curing catalyst (component (D)) and the organic peroxide (component (E)) were added after cooling. In this manner, varnishes containing the resin compositions of Examples 1 to 14 and Comparative Examples 1 to 5 were prepared.

[0085] [Component (A)] (A-1): Partially hydrogenated styrene-based thermoplastic elastomer (SBBS (1)), manufactured by Asahi Kasei Chemicals Corporation, trade name "P1083". (A-2): Partially hydrogenated styrene-based thermoplastic elastomer (SBBS (2)), manufactured by Asahi Kasei Chemicals Corporation, trade name "P1500". (A-3): Partially hydrogenated styrene-based thermoplastic elastomer (SBBS (3)), manufactured by Asahi Kasei Chemicals Corporation, trade name "P5051". (A-4): Partially hydrogenated styrene-based thermoplastic elastomer (SBBS (4)), manufactured by Asahi Kasei Chemicals Corporation, trade name "P2000". [Component (A')] (A'-5): Non-hydrogenated styrene-based thermoplastic elastomer (SBS (1)), manufactured by JSR Corporation, trade name "TR2003". (A'-6): Hydrogenated styrene-based thermoplastic elastomer (SEBS (1)), manufactured by Asahi Kasei Chemicals Corporation, trade name "H1517". [Component (B)] (B-1): Epoxy resin, manufactured by Nippon Kayaku Co., Ltd., trade name "EPPN-502H". (B-2): Epoxy resin, manufactured by Mitsubishi Chemical Corporation, trade name "828EL". [Component (C)] (C-1): Thermosetting resin other than epoxy resin, manufactured by Mitsubishi Gas Chemical Company, Inc., trade name "OPE-1200". (C-2): Thermosetting resin other than epoxy resin, manufactured by Mitsubishi Gas Chemical Company, Inc., trade name "OPE-2200". [Component (D)] (D-1): Curing catalyst, imidazole, manufactured by Adeka Corporation, trade name "EH2021". (D-2): Curing catalyst, 2-ethyl-4-methylimidazole, trade name "2E4MZ", manufactured by Shikoku Chemicals Corporation. [Component (E)] (E-1): Organic peroxide, manufactured by NOF Corporation, trade name "Perbutyl Z". (E-2): Organic peroxide, manufactured by NOF Corporation, trade name "Percumyl D". [Other compounding agents] (Inorganic particle-1): Fused silica, manufactured by Denka Company, trade name "FB-300MDX". (Inorganic particle-2): Fused silica, manufactured by Denka Company, trade name "FB-300MDX (low dielectric tangent treatment)".

[0086] In Examples 1 to 11, 13, and 14 and Comparative Example 3, resin compositions were prepared using two of the elastomers (A-1) to (A-4) as component (A). In particular, in Examples 1 to 11, 13, and 14, the amounts of the two elastomers were adjusted so that the average styrene ratio of component (A) was within the range of 33 to 46%. The "Elastomer Content Ratio of Components (A) and (A')" column in Tables 1 to 4 indicates the content ratio (%) of component (A) and component (A') relative to the total of 100.00% of components (A) to (D). Additionally, the "Ratio of First Elastomer" and "Ratio of Second Elastomer" columns in Tables 1 to 4 indicate the ratio (%) of the two elastomers used as components (A) and (A'). When only one type of component (A) and one type of component (A') were used, the "First elastomer ratio" column was entered as "100.00%." ​​The "Average styrene ratio" column in Tables 1 to 4 indicates the styrene ratio of the component (A) and the component (A') used in each example and comparative example. In Examples 13 and 14, the resin compositions were prepared by further adding fused silica as shown in Table 3 as an additional compounding agent.

[0087] Next, the varnish containing the obtained resin composition was applied to one side of a support (a PET film subjected to a release treatment) and dried at 100° C. to obtain an adhesive film with a support.

[0088] Next, a release-treated PET film was placed on the adhesive film with a support prepared in each Example and Comparative Example to obtain a film laminate of PET film / adhesive film / PET film. This film laminate was pressed at a temperature of 200°C for a temperature holding time of 75 minutes under a pressure of 0.44 MPa (45 kgf / cm). ２ The adhesive film was then heat-cured by hot pressing under the heating and pressing conditions of 100°C (100°F). The release-treated PET films on both sides of the cured adhesive film were removed, and the following evaluations were carried out. The results of each evaluation are shown in Tables 1 to 4.

[0089] [Dielectric constant (ε), dielectric loss tangent (tanδ)] The adhesive film was subjected to a temperature test at 200°C for 75 minutes under a pressure of 0.44 MPa (45 kgf / cm ２), and peeled off from the support, a test piece (50±0.5 mm x 100±2 mm) was cut out from the adhesive film, and the thickness was measured. The film whose thickness had been measured was subjected to measurement of the dielectric constant (ε) and dielectric loss tangent (tan δ) by a dielectric resonator method (SPDR method). The measurement frequency by the dielectric resonator method was 10 GHz. The dielectric constant (ε) is preferably 3.0 or less, more preferably 2.5 or less. The dielectric loss tangent (tan δ) is preferably 0.0025 or less, more preferably 0.0020 or less.

[0090] [Adhesive Peel Strength (Copper Foil)] Copper foil was attached to both sides of the adhesive film with the roughened side facing inward, and then thermocompression bonded using a press. The thermocompression bonding conditions were 200°C, 75 minutes, and 0.44 MPa (45 kgf / cm ２ The test pieces thus obtained were cut into 10 mm widths and peeled off using an autograph to measure the peel strength. The average value of N=5 for each measurement result was calculated. The adhesive peel strength (copper foil) is preferably 4 or more.

[0091] [Adhesive Peel Strength (LCP)] Copper foil was attached to one side of the adhesive film with the roughened surface facing inward, and LCP was attached to the other side, followed by thermocompression bonding using a press. The thermocompression bonding conditions were 200°C, 75 minutes, and 0.44 MPa (45 kgf / cm ２ The test pieces thus obtained were cut into 10 mm widths and peeled off using an autograph to measure the peel strength. The average value of N=5 for each measurement result was calculated. The adhesive peel strength (LCP) is preferably 3 or more.

[0092] [Flow Rate] The flow rate was measured by the method shown in FIGS. 1 to 3. FIGS. 1 to 3 are schematic diagrams illustrating the method for measuring the flow rate. In FIGS. 1 to 3, (a) is a plan view of a test piece used to measure the flow rate, and (b) shows the A-A' cross section of FIG. 1, the B-B' cross section of FIG. 2, and the C-C' cross section of FIG. 3, respectively. To measure the flow rate, first, as shown in FIG. 1, an 18 μm thick copper foil 12 was bonded to one side of an adhesive film 11 cut to a size of 100 mm x 100 mm, with the shiny side facing inward. The copper foil 12 also had the same size as the adhesive film 11, 100 mm x 100 mm. Next, as shown in FIG. 2, holes 20 with a diameter of 6 mm were punched through the adhesive film 11 and the copper foil 12 at the middle of each side of the rectangular periphery of the adhesive film 11 bonded to the copper foil 12, to prepare a test piece 10 for measuring the flow rate. Next, as shown in Fig. 3, LCP 13 was attached to one side of the obtained test piece 10 and thermocompression bonded using a press. The thermocompression bonding conditions were 200°C, 75 minutes, and 0.44 MPa (45 kgf / cm ２ After press curing, the portions of the test piece 10 where the holes 20 were drilled were observed under an electron microscope, and the length (μm) of the resin flow at each of the four portions where the holes 20 were drilled was measured. The length (μm) of the resin flow was measured as the length of the largest portion of the resin flow at each of the portions where the holes 20 were drilled. The average value of the lengths of the resin flow at the four points was used as the measured value for evaluating the amount of flow. In evaluating the amount of flow, the measured value (average value) must be 150 μm or less, and preferably 80 μm or less.

[0093] [Reliability (moisture absorption reflow)] An LCP cut to 100 mm x 100 mm was attached to both sides of an adhesive film cut to 100 mm x 100 mm, and the LCP was thermocompression bonded using a press. The thermocompression bonding conditions were 200°C, 75 minutes, and 0.44 MPa (45 kgf / cm ２) The test pieces thus obtained were cut into five 10 mm x 100 mm strips and placed in a thermostatic chamber at a temperature of 85°C and a humidity of 85% for 12 hours. After 12 hours had elapsed, the test pieces were removed from the thermostatic chamber and passed through a reflow furnace at 260°C five times. If there was no swelling or peeling after moisture absorption and reflow, the test piece was deemed to have passed, and this is indicated as "Pass" in Tables 1 to 4. On the other hand, if there was swelling or peeling after moisture absorption and reflow, the test piece was deemed to have failed, and this is indicated as "NG" in Tables 1 to 4.

[0094] [Solder Heat Resistance Test] This test was carried out in accordance with JIS C5012 (1993). Specifically, copper foil was attached to both sides of the adhesive film with the roughened side facing inward, and the foil was then thermocompressed using a press. The thermocompression conditions were 200°C, 75 minutes, and 0.44 MPa (45 kgf / cm). ２ The obtained test pieces were cut into 25 mm x 25 mm pieces, floated in a solder bath heated to 288°C, and checked for the presence or absence of swelling for 3 minutes. If no swelling occurred within 3 minutes, the test piece was deemed to have passed, and is marked with "Pass" in Tables 1 to 4. On the other hand, if swelling occurred within 3 minutes, the test piece was deemed to have failed, and is marked with "NG" in Tables 1 to 4.

[0095]

[0096]

[0097]

[0098]

[0099] [Results] As shown in Tables 1 to 3, the resin compositions of Examples 1 to 14, in which the average styrene ratio of component (A) was set to a predetermined value, showed good results in all evaluations of dielectric constant (ε), dielectric loss tangent (tan δ), adhesive peel strength (copper foil), adhesive peel strength (LCP), flow amount, reliability (moisture absorption reflow), and solder heat resistance test. In particular, the resin compositions of Examples 1 to 14 were capable of producing adhesive films that could suppress resin flow to 150 μm or less in the flow amount measurement, and were capable of suppressing resin flow in drilled areas when multi-layering high-frequency boards.

[0100] The resin composition of Comparative Example 1 had an excessively high styrene ratio in component (A), making it impossible to form a film. The resin composition of Comparative Example 2 had an excessively low styrene ratio in component (A), resulting in a resin flow of 200 μm in the flow measurement. The resin composition of Comparative Example 3 did not contain an epoxy resin as component (B), and therefore failed the evaluations of adhesive peel strength (LCP), reliability (moisture absorption reflow), and solder heat resistance tests. The resin composition of Comparative Example 4 did not contain styrene / butadiene / butylene / styrene block copolymer (SBBS) as component (A), but instead contained styrene / butadiene / styrene block copolymer (SBS(1)), and therefore failed the evaluations of dielectric loss tangent (tanδ), adhesive peel strength (LCP), and flow. The resin composition of Comparative Example 5 also did not contain styrene / butadiene / butylene / styrene block copolymer (SBBS) as component (A), but instead contained styrene / butadiene / styrene block copolymer (SEBS (1)), and failed the reliability (moisture absorption reflow) and solder heat resistance tests.

[0101] The resin composition of the present invention can be used as a resin composition for adhesive films. The adhesive film and interlayer bonding sheet of the present invention can also be used in the manufacture of interlayer insulating films for printed wiring boards and electronic components.

[0102] 10 Test piece 11 Adhesive film 12 Copper foil 13 LCP 20 Hole

Claims

1. (A) a styrene / butadiene / butylene / styrene block copolymer; (B) an epoxy resin; and (C) a thermosetting resin other than an epoxy resin; Including, A resin composition, wherein the styrene ratio of the component (A) is 31 to 60%.

2. The component (A) is (A1) a first styrene / butadiene / butylene / styrene block copolymer having a styrene ratio of 40% or more; (A2) a second styrene / butadiene / butylene / styrene block copolymer having a styrene ratio of less than 40%, The resin composition according to claim 1 .

3. The resin composition according to claim 1 or 2, wherein the component (C) is a terminal-modified polyphenylene ether resin.

4. 3. The resin composition according to claim 1, wherein the component (C) is a modified polyphenylene ether resin having a terminal carbon-carbon double bond.

5. The resin composition according to claim 1 or 2, wherein the content ratio of the (C) component to the (A) component is, in mass ratio, (C) component:(A) component=10:90 to 40:

60.

6. The resin composition according to claim 1 or 2, wherein the (B) component is contained in an amount of 0.1 to 3 mass% based on 100 mass% of the resin components in the resin composition.

7. The resin composition according to claim 1 or 2, further comprising a curing catalyst (D).

8. The resin composition according to claim 1 or 2, further comprising (E) an organic peroxide.

9. An adhesive film using the resin composition according to claim 1 or 2.

10. A bonding sheet for interlayer bonding, which uses the resin composition according to claim 1 or 2.

11. A cured product comprising the resin composition according to claim 1 or 2.

12. A cured product comprising the adhesive film according to claim 9.

13. A laminate in which a member containing a liquid crystal polymer is laminated using the bonding sheet for interlayer bonding according to claim 10.

14. A cured product comprising the laminate according to claim 13.

15. A laminate comprising the resin composition according to claim 1 or 2.

16. A semiconductor device using the resin composition according to claim 1 or 2.

17. The method includes a step of mixing (A) a styrene / butadiene / butylene / styrene block copolymer, (B) an epoxy resin, and (C) a thermosetting resin other than an epoxy resin, As the component (A), at least (A1) a first styrene / butadiene / butylene / styrene block copolymer having a styrene ratio of 40% or more and (A2) a second styrene / butadiene / butylene / styrene block copolymer having a styrene ratio of less than 40% are used, A method for producing a resin composition, comprising adjusting a compounding ratio of the (A1) component and the (A2) component so that a styrene ratio of the (A) component is 31 to 60%.