JP7135970B2 - resin composition - Google Patents

Description

The present invention relates to a resin composition containing a thermosetting resin and an inorganic filler.

In recent years, there has been an increasing demand for semiconductor components that are thinner, lighter, and have a higher mounting density. In order to meet this demand, the use of flexible substrates as substrate substrates for semiconductor components has attracted attention. Flexible substrates can be made thinner and lighter than rigid substrates. Furthermore, since the flexible substrate is flexible and deformable, it can be folded and mounted.

Insulating materials for flexible substrates generally need to be blended with a softening resin component, but blending a softening resin component may increase tackiness (adhesiveness), resulting in poor handleability. In this case, it is possible to suppress the tackiness by blending an inorganic filler (Patent Document 1), but if the blending ratio of the inorganic filler becomes high, it becomes difficult to achieve both flexibility and flexibility.

JP 2014-95047 A

Accordingly, an object of the present invention is to provide a resin composition that maintains excellent flexibility while suppressing tackiness to a low level.

In order to achieve the object of the present invention, as a result of intensive studies by the present inventors, a resin composition containing (A) a thermosetting resin, (D) an adhesive softening agent, and (B) an inorganic filler, The inventors have found that by blending 5% by mass or more of the organic filler (C), it is possible to keep the tackiness low while maintaining excellent flexibility, and have completed the present invention.

That is, the present invention includes the following contents.
[1] A resin composition comprising (A) a thermosetting resin, (B) an inorganic filler, (C) an organic filler, and (D) an adhesive softener,
A resin composition in which the content of component (C) is 5% by mass or more when the non-volatile component in the resin composition is taken as 100% by mass.
[2] The resin composition according to [1] above, wherein the content of component (B) is 50% by mass or less when the non-volatile component in the resin composition is taken as 100% by mass.
[3] The resin composition according to [1] or [2] above, wherein the content of component (C) is 10% by mass or less when the non-volatile component in the resin composition is 100% by mass.
[4] Any one of [1] to [3] above, wherein component (D) is selected from the group consisting of resins having a polybutadiene structure, polyrotaxane resins, polyimide resins, and maleimide resins having a dimer acid skeleton. of the resin composition.
[5] The resin composition according to any one of [1] to [4] above, wherein the content of component (D) is 1% by mass or more when the non-volatile component in the resin composition is 100% by mass. thing.
[6] The resin composition according to any one of [1] to [5] above, wherein (C) the organic filler is a core-shell type graft copolymer particle.
[7] The resin composition according to [6] above, wherein the monomer component forming the shell portion of the core-shell type graft copolymer particles is a (meth)acrylic acid ester.
[8] The resin composition according to [6] or [7] above, wherein the core particles of the core-shell type graft copolymer particles contain a thermoplastic elastomer.
[9] The resin composition according to any one of [1] to [8] above, wherein the component (A) is an epoxy resin.
[10] The resin composition according to any one of [1] to [9] above, further comprising (E) a curing agent.
[11] The resin composition according to [10] above, wherein the component (E) contains an active ester curing agent.
[12] The resin composition according to any one of [1] to [11] above, wherein the resin composition has a solid content of 95% by mass or less.
[13] The resin composition according to any one of [1] to [12] above, which is used for forming an insulating layer of a multilayer flexible substrate.
[14] A cured product of the resin composition described in any one of [1] to [13] above.
[15] A resin sheet comprising a support and a resin composition layer formed on the support and formed of the resin composition according to any one of [1] to [13].
[16] A multilayer flexible substrate comprising an insulating layer formed by curing the resin composition according to any one of [1] to [13] above.
[17] A semiconductor device comprising the multilayer flexible substrate according to [16] above.

ADVANTAGE OF THE INVENTION According to the resin composition of this invention, tackiness can be suppressed low, maintaining the outstanding softness|flexibility.

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will now be described in detail with reference to its preferred embodiments. However, the present invention is not limited to the following embodiments and examples, and can be arbitrarily modified without departing from the scope of the claims of the present invention and their equivalents.

<Resin composition>
The resin composition of the present invention contains (A) a thermosetting resin, (B) an inorganic filler, (C) an organic filler, and (D) an adhesive softener. The content of component (C) is 5% by mass or more when the non-volatile component in the resin composition is 100% by mass.

By using such a resin composition, tackiness can be kept low while maintaining excellent flexibility.

The resin composition of the present invention contains (A) a thermosetting resin, (B) an inorganic filler, (C) an organic filler, and (D) an adhesive softening agent, as well as optional components. You can Optional components include, for example, (E) a curing agent, (F) a curing accelerator, (G) other additives, and (H) an organic solvent. Each component contained in the resin composition will be described in detail below.

<(A) Thermosetting resin>
The resin composition of the present invention contains (A) a thermosetting resin. (A) The thermosetting resin does not include those corresponding to the (D) component. (A) The thermosetting resin can be a known one and is not particularly limited, but examples include polyester resin, polyurethane resin, polyester urethane resin, butyral resin, acrylic resin, cyanate resin, silicone resin, and oxetane resin , melamine resins, etc., among which epoxy resins are preferred.

Examples of epoxy resins include bixylenol type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bisphenol AF type epoxy resin, dicyclopentadiene type epoxy resin, trisphenol type epoxy resin, Naphthol novolak type epoxy resin, phenol novolak type epoxy resin, tert-butyl-catechol type epoxy resin, naphthalene type epoxy resin, naphthol type epoxy resin, anthracene type epoxy resin, glycidylamine type epoxy resin, glycidyl ester type epoxy resin, cresol novolac type epoxy resin, biphenyl type epoxy resin, linear aliphatic epoxy resin, alicyclic epoxy resin, heterocyclic epoxy resin, spiro ring-containing epoxy resin, cyclohexane type epoxy resin, cyclohexanedimethanol type epoxy resin, naphthylene ether type epoxy resin Epoxy resins, trimethylol-type epoxy resins, tetraphenylethane-type epoxy resins, and the like. Epoxy resins may be used singly or in combination of two or more.

The resin composition preferably contains, as an epoxy resin, an epoxy resin having two or more epoxy groups in one molecule. From the viewpoint of significantly obtaining the desired effect of the present invention, the ratio of the epoxy resin having two or more epoxy groups in one molecule to 100% by mass of the non-volatile components of the epoxy resin is preferably 50% by mass or more. More preferably 60% by mass or more, particularly preferably 70% by mass or more.

Epoxy resins include liquid epoxy resins at a temperature of 20° C. (hereinafter sometimes referred to as “liquid epoxy resins”) and solid epoxy resins at a temperature of 20° C. (hereinafter sometimes referred to as “solid epoxy resins”). ). The resin composition of the present invention may contain only a liquid epoxy resin as an epoxy resin, or may contain only a solid epoxy resin, and may contain a combination of a liquid epoxy resin and a solid epoxy resin. is preferred.

A liquid epoxy resin having two or more epoxy groups in one molecule is preferable as the liquid epoxy resin.

Examples of liquid epoxy resins include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AF type epoxy resin, naphthalene type epoxy resin, glycidyl ester type epoxy resin, glycidyl amine type epoxy resin, phenol novolak type epoxy resin, ester skeleton. An alicyclic epoxy resin, a cyclohexane-type epoxy resin, a cyclohexanedimethanol-type epoxy resin, and a glycidylamine-type epoxy resin are preferred.

Specific examples of liquid epoxy resins include "HP4032", "HP4032D", and "HP4032SS" (naphthalene type epoxy resins) manufactured by DIC; "828US", "828EL", "jER828EL", and "825" manufactured by Mitsubishi Chemical Corporation; ", "Epikote 828EL" (bisphenol A type epoxy resin); "jER807" and "1750" (bisphenol F type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "jER152" (phenol novolac type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "630" and "630LSD" (glycidylamine type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "ZX1059" manufactured by Nippon Steel & Sumikin Chemical Co., Ltd. (mixture of bisphenol A type epoxy resin and bisphenol F type epoxy resin); Nagase ChemteX Corporation "EX-721" (glycidyl ester type epoxy resin) manufactured by Daicel Corporation; "Celoxide 2021P" manufactured by Daicel Corporation (alicyclic epoxy resin having an ester skeleton); "ZX1658" and "ZX1658GS" manufactured by Nippon Steel & Sumikin Chemical Co., Ltd. 1,4-glycidylcyclohexane type epoxy resin) and the like. These may be used individually by 1 type, and may be used in combination of 2 or more types.

The solid epoxy resin is preferably a solid epoxy resin having 3 or more epoxy groups per molecule, more preferably an aromatic solid epoxy resin having 3 or more epoxy groups per molecule.

Solid epoxy resins include bixylenol type epoxy resin, naphthalene type epoxy resin, naphthalene type tetrafunctional epoxy resin, cresol novolak type epoxy resin, dicyclopentadiene type epoxy resin, trisphenol type epoxy resin, naphthol type epoxy resin, biphenyl type epoxy resin, naphthylene ether type epoxy resin, anthracene type epoxy resin, bisphenol A type epoxy resin, bisphenol AF type epoxy resin, and tetraphenylethane type epoxy resin.

Specific examples of solid epoxy resins include "HP4032H" (naphthalene-type epoxy resin) manufactured by DIC; "HP-4700" and "HP-4710" (naphthalene-type tetrafunctional epoxy resin) manufactured by DIC; "N-690" (cresol novolac type epoxy resin) manufactured by DIC Corporation; "N-695" (cresol novolak type epoxy resin) manufactured by DIC Corporation; "HP-7200", "HP-7200HH", "HP -7200H" (dicyclopentadiene type epoxy resin); DIC's "EXA-7311", "EXA-7311-G3", "EXA-7311-G4", "EXA-7311-G4S", "HP6000" ( Naphthylene ether type epoxy resin); Nippon Kayaku Co., Ltd. "EPPN-502H" (trisphenol type epoxy resin); Nippon Kayaku Co., Ltd. "NC7000L" (naphthol novolac type epoxy resin); "NC3000H", "NC3000", "NC3000L", "NC3100" (biphenyl type epoxy resin); "ESN475V" (naphthol type epoxy resin) manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.; type epoxy resin); "YX4000H", "YX4000", "YL6121" (biphenyl type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "YX4000HK" (bixylenol type epoxy resin) manufactured by Mitsubishi Chemical Corporation; YX8800" (anthracene type epoxy resin); "YX7700" (xylene structure-containing novolac type epoxy resin) manufactured by Mitsubishi Chemical; "PG-100" and "CG-500" manufactured by Osaka Gas Chemicals; "YL7760" (bisphenol AF type epoxy resin); "YL7800" (fluorene type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "jER1010" (solid bisphenol A type epoxy resin) manufactured by Mitsubishi Chemical Corporation; jER1031S" (tetraphenylethane type epoxy resin) and the like. These may be used individually by 1 type, and may be used in combination of 2 or more types.

When a liquid epoxy resin and a solid epoxy resin are used in combination as the epoxy resin, their mass ratio (liquid epoxy resin: solid epoxy resin) is preferably 1:1 to 1:50, more preferably 1:3. to 1:30, particularly preferably 1:5 to 1:20. By setting the mass ratio of the liquid epoxy resin to the solid epoxy resin within such a range, the desired effect of the present invention can be significantly obtained.

The epoxy equivalent of the epoxy resin is preferably 50 g/eq. ~5,000 g/eq. , more preferably 50 g/eq. ~3,000 g/eq. , more preferably 80 g/eq. ~2,000 g/eq. , even more preferably 110 g/eq. ~1,000 g/eq. is. Within this range, the crosslink density of the cured product of the resin composition is sufficient, and an insulating layer with a small surface roughness can be obtained. Epoxy equivalent weight is the mass of resin containing one equivalent of epoxy groups. This epoxy equivalent can be measured according to JIS K7236.

The weight average molecular weight (Mw) of the epoxy resin is preferably 100 to 5,000, more preferably 250 to 3,000, and still more preferably 400 to 1,500, from the viewpoint of significantly obtaining the desired effects of the present invention. be. The weight average molecular weight of the resin can be measured as a polystyrene-equivalent value by a gel permeation chromatography (GPC) method.

(A) The content of the thermosetting resin is not particularly limited, but when the non-volatile component in the resin composition is 100% by mass, it is preferably 5% by mass or more, more preferably 10% by mass or more. , more preferably 15% by mass or more, and particularly preferably 20% by mass or more. (A) The upper limit of the content of the thermosetting resin is not particularly limited. % or less, more preferably 30 mass % or less, and particularly preferably 25 mass % or less.

<(B) Inorganic filler>
The resin composition of the present invention contains (B) an inorganic filler.

(B) The material of the inorganic filler is not particularly limited, but examples include silica, alumina, glass, cordierite, silicon oxide, barium sulfate, barium carbonate, talc, clay, mica powder, zinc oxide, hydrotalcite, Boehmite, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, magnesium oxide, boron nitride, aluminum nitride, manganese nitride, aluminum borate, strontium carbonate, strontium titanate, calcium titanate, magnesium titanate, bismuth titanate , titanium oxide, zirconium oxide, barium titanate, barium zirconate titanate, barium zirconate, calcium zirconate, zirconium phosphate, and zirconium tungstate phosphate. Silica is particularly preferred. Examples of silica include amorphous silica, fused silica, crystalline silica, synthetic silica, and hollow silica. As silica, spherical silica is preferable. (B) The inorganic filler may be used singly or in combination of two or more.

The average particle size of the inorganic filler (B) is not particularly limited, but from the viewpoint of obtaining the desired effect of the present invention, it is preferably 10 μm or less, more preferably 5 μm or less, further preferably 3 μm or less, and further preferably 3 μm or less. It is more preferably 2 μm or less, particularly preferably 1 μm or less. From the viewpoint of obtaining the desired effects of the present invention, the lower limit of the average particle size of the inorganic filler is preferably 0.01 µm or more, more preferably 0.05 µm or more, still more preferably 0.1 µm or more, and even more preferably 0. .2 μm or more, particularly preferably 0.25 μm or more. The average particle size of the inorganic filler can be measured by a laser diffraction/scattering method based on Mie scattering theory. Specifically, the particle size distribution of the inorganic filler is prepared on a volume basis using a laser diffraction/scattering type particle size distribution measuring device, and the median diameter can be used as the average particle size for measurement. A measurement sample can be obtained by weighing 100 mg of an inorganic filler and 10 g of methyl ethyl ketone in a vial and dispersing them with ultrasonic waves for 10 minutes. A measurement sample is measured using a laser diffraction particle size distribution measuring device, the wavelengths of the light source used are blue and red, the volume-based particle size distribution of the inorganic filler is measured by the flow cell method, and from the obtained particle size distribution The average particle diameter was calculated as the median diameter. Examples of the laser diffraction particle size distribution analyzer include "LA-960" manufactured by Horiba, Ltd., and the like.

(B) Commercially available inorganic fillers include, for example, “UFP-30” manufactured by Denka Kagaku Kogyo; “SP60-05” and “SP507-05” manufactured by Nippon Steel & Sumikin Materials; "YC100C", "YA050C", "YA050C-MJE", "YA010C"; "UFP-30" manufactured by Denka; 5N”; Admatechs “SC2500SQ”, “SO-C4”, “SO-C2”, “SO-C1”;

(B) Inorganic fillers include aminosilane-based coupling agents, epoxysilane-based coupling agents, mercaptosilane-based coupling agents, alkoxysilane compounds, organosilazane compounds, titanate-based coupling agents, from the viewpoint of improving moisture resistance and dispersibility. It is preferably treated with one or more surface treatment agents such as agents. Examples of commercially available surface treatment agents include "KBM403" (3-glycidoxypropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., "KBM803" (3-mercaptopropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., Shin-Etsu Chemical Industry Co., Ltd. "KBE903" (3-aminopropyltriethoxysilane), Shin-Etsu Chemical Co., Ltd. "KBM573" (N-phenyl-3-aminopropyltrimethoxysilane), Shin-Etsu Chemical Co., Ltd. "SZ-31" ( Hexamethyldisilazane), Shin-Etsu Chemical Co., Ltd. "KBM103" (phenyltrimethoxysilane), Shin-Etsu Chemical Co., Ltd. "KBM-4803" (long-chain epoxy type silane coupling agent), Shin-Etsu Chemical Co., Ltd. "KBM- 7103” (3,3,3-trifluoropropyltrimethoxysilane).

From the viewpoint of improving the dispersibility of the inorganic filler, the degree of surface treatment with the surface treatment agent is preferably within a predetermined range. Specifically, 100% by mass of the inorganic filler is preferably surface-treated with a surface treatment agent of 0.2% to 5% by mass, and is surface-treated with 0.2% to 3% by mass. preferably 0.3 mass % to 2 mass % of the surface treatment.

The degree of surface treatment by the surface treatment agent can be evaluated by the amount of carbon per unit surface area of the inorganic filler. The amount of carbon per unit surface area of the inorganic filler is preferably 0.02 mg/m ² or more, more preferably 0.1 mg/m ² or more, and more preferably 0.2 mg/m ² from the viewpoint of improving the dispersibility of the inorganic filler. The above is more preferable. On the other hand, from the viewpoint of preventing an increase in the melt viscosity of the resin composition and the melt viscosity in the form of a sheet, it is preferably 1 mg/m ² or less, more preferably 0.8 mg/m ² or less, and 0.5 mg/m ² or less. More preferred.

(B) The amount of carbon per unit surface area of the inorganic filler can be measured after the surface-treated inorganic filler is washed with a solvent (eg, methyl ethyl ketone (MEK)). Specifically, a sufficient amount of MEK as a solvent is added to the inorganic filler surface-treated with the surface treatment agent, and ultrasonic cleaning is performed at 25° C. for 5 minutes. After removing the supernatant liquid and drying the solid content, a carbon analyzer can be used to measure the amount of carbon per unit surface area of the inorganic filler. As a carbon analyzer, "EMIA-320V" manufactured by Horiba Ltd. can be used.

(B) The inorganic filler preferably has a specific surface area of 1 m ² /g or more, more preferably 2 m ² /g or more, and particularly preferably 3 m ² /g or more. Although there is no particular upper limit, it is preferably 50 m ² /g or less, more preferably 20 m ² /g or less. The specific surface area of the inorganic filler is determined by adsorbing nitrogen gas on the sample surface using a specific surface area measuring device (Macsorb HM-1210 manufactured by Mountech) according to the BET method, and calculating the specific surface area using the BET multipoint method. obtained by

(B) The content of the inorganic filler is preferably 70% by mass or less, more preferably 60% by mass, from the viewpoint of obtaining a cured product with more excellent flexibility when the non-volatile component in the resin composition is 100% by mass. % by mass or less, more preferably 50% by mass or less, particularly preferably 45% by mass or less. (B) The lower limit of the content of the inorganic filler is not particularly limited, but from the viewpoint of obtaining a cured product having sufficient mechanical strength, when the non-volatile component in the resin composition is 100% by mass , preferably 20% by mass or more, more preferably 30% by mass or more, still more preferably 35% by mass or more, and particularly preferably 38% by mass or more.

<(C) Organic filler>
The resin composition of the present invention contains (C) an organic filler. (C) Organic fillers do not include those corresponding to component (D). By including the component (C) in the resin composition, the tackiness can be reduced and the handleability can be improved.

(C) The organic filler is present in particulate form in the resin composition. (C) Organic fillers include, for example, rubber particles, polyamide fine particles, and silicone particles. In the present invention, rubber particles are preferably used from the viewpoint of significantly obtaining the desired effects of the present invention.

Examples of the rubber component contained in the rubber particles include polybutadiene, polyisoprene, polychlorobutadiene, ethylene-vinyl acetate copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-isobutylene copolymer, Olefin thermoplastic elastomers such as acrylonitrile-butadiene copolymers, isoprene-isobutylene copolymers, isobutylene-butadiene copolymers, ethylene-propylene-diene terpolymers, ethylene-propylene-butene terpolymers; Thermoplastic elastomers such as acrylic thermoplastic elastomers such as polypropyl (meth)acrylate, polybutyl (meth)acrylate, polycyclohexyl (meth)acrylate, and polyoctyl (meth)acrylate, preferably It is an olefinic thermoplastic elastomer, more preferably a styrene-butadiene copolymer. Further, the rubber component may be mixed with silicone rubber such as polyorganosiloxane rubber. The rubber component contained in the rubber particles has a glass transition temperature of, for example, 0° C. or lower, preferably −10° C. or lower, more preferably −20° C. or lower, and even more preferably −30° C. or lower.

(C) The organic filler is preferably core-shell type particles from the viewpoint of significantly obtaining the desired effects of the present invention. The core-shell type particles are particulate organic fillers composed of a core particle containing a rubber component as described above and one or more layers of shell covering the core particle. Further, the core-shell type particles are composed of a core particle containing a rubber component as described above and a shell portion obtained by graft copolymerizing a monomer component copolymerizable with the rubber component contained in the core particle. It is preferably a type graft copolymer particle. The term "core-shell type" as used herein does not necessarily refer only to particles in which the core particle and the shell part can be clearly distinguished, and includes particles in which the boundary between the core particle and the shell part is unclear. It does not have to be completely covered with parts.

The content of the rubber component in the core-shell type graft copolymer particles is preferably 40% by mass or more, more preferably 50% by mass or more, and even more preferably 60% by mass or more. The upper limit of the content of the rubber component in the core-shell type graft copolymer particles is not particularly limited. % by mass is preferred.

Examples of the monomer component forming the shell portion of the core-shell type graft copolymer particles include methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, cyclohexyl (meth)acrylate, (Meth)acrylic acid esters such as octyl (meth)acrylate and glycidyl (meth)acrylate; (meth)acrylic acid; N-substituted maleimides such as N-methylmaleimide and N-phenylmaleimide; maleimide; maleic acid, itacon α,β-unsaturated carboxylic acids such as acids; aromatic vinyl compounds such as styrene, 4-vinyltoluene and α-methylstyrene; ) methyl acrylate is more preferred.

Commercially available core-shell type graft copolymer particles include, for example, "CHT" manufactured by Cheil Industries; "B602" manufactured by UMGABS; and "Paraloid EXL2602" and "Paraloid EXL2603" manufactured by Dow Chemical Japan. , "Paraloid EXL2655", "Paraloid EXL2311", "Paraloid EXL2313", "Paraloid EXL2315", "Paraloid KM330", "Paraloid KM336P", "Paraloid KCZ201", Mitsubishi Rayon's "Metabrene C-223A", "Metabrene E-901", "Metabrene S-2001", "Metabrene W-450A", "Metabrene SRK-200", Kaneka's "Kane Ace M-511", "Kane Ace M-600", "Kane Ace M-400", "Kane Ace M-580", "Kane Ace MR-01" and the like. These may be used individually by 1 type, and may be used in combination of 2 or more types.

The average particle diameter (average primary particle diameter) of the core-shell type graft copolymer particles is not particularly limited, but is preferably 20 nm or more, more preferably 50 nm or more, still more preferably 80 nm or more, and particularly preferably It is 100 nm or more, preferably 5,000 nm or less, more preferably 2,000 nm or less, still more preferably 1,000 nm or less, and particularly preferably 500 nm or less. The average particle size (average primary particle size) of the core-shell type graft copolymer particles can be measured using a zeta potential particle size distribution analyzer or the like.

(C) The content of the organic filler is 5.0% by mass or more when the non-volatile component in the resin composition is 100% by mass, and the tackiness is suppressed as much as possible, and (B) the use of an inorganic filler From the viewpoint of obtaining a more flexible cured product by suppressing the amount as much as possible, it is preferably 5.5% by mass or more, more preferably 5.8% by mass or more, still more preferably 6.0% by mass or more, and particularly preferably 6.0% by mass or more. .2% by mass or more. (C) The upper limit of the content of the organic filler is preferably 30% by mass or less, more preferably 20% by mass or less, more preferably 20% by mass or less, when the non-volatile component in the resin composition is 100% by mass, from the viewpoint of keeping the viscosity as low as possible. is 15% by mass or less, more preferably 10% by mass or less, particularly preferably 8% by mass or less from the viewpoint of reducing void defects and achieving better pattern embedding properties.

<(D) Adhesive softener>
The resin composition of the present invention contains (D) an adhesive softening agent.

(D) The tacky softening agent means a component having a property of increasing the adhesiveness of the cured product among the softening agents that impart flexibility to the cured product of the thermosetting resin. (D) Adhesive softening agent can use a wide range of known softening agents having a property of increasing the adhesiveness of the cured product. (D) Adhesive softening agents include, for example, resins having a polybutadiene structure (hereinafter referred to as "polybutadiene resins"), polyrotaxane resins, polyimide resins, maleimide resins having a dimer acid skeleton, and the like, but are not limited to these. not something.

The polybutadiene structure includes not only a structure formed by polymerizing butadiene but also a structure formed by hydrogenating the structure. Also, the butadiene structure may be partially hydrogenated or entirely hydrogenated. Furthermore, the polybutadiene structure may be contained in the main chain or in the side chains of component (D).

Preferred examples of polybutadiene resins include hydrogenated polybutadiene skeleton-containing resins, hydroxyl group-containing polybutadiene resins, phenolic hydroxyl group-containing polybutadiene resins, carboxyl group-containing polybutadiene resins, acid anhydride group-containing polybutadiene resins, epoxy group-containing polybutadiene resins, and isocyanate group-containing polybutadiene resins. polybutadiene resins containing urethane groups, polybutadiene resins containing urethane groups, polyphenylene ether-polybutadiene resins, and the like. Here, the "hydrogenated polybutadiene skeleton-containing resin" refers to a resin in which at least a portion of the polybutadiene skeleton is hydrogenated, and does not necessarily have to be a resin in which the polybutadiene skeleton is completely hydrogenated. Examples of hydrogenated polybutadiene skeleton-containing resins include hydrogenated polybutadiene skeleton-containing epoxy resins. Examples of the phenolic hydroxyl group-containing polybutadiene resin include resins having a polybutadiene structure and having a phenolic hydroxyl group.

Specific examples of the polybutadiene resin, which is a resin having a polybutadiene structure in the molecule, include "BX360" and "BX660" (polyphenylene ether-polybutadiene resin) manufactured by Nippon Kayaku Co., Ltd., and "Ricon 657" (epoxy group-containing polybutadiene), "Ricon 130MA8", "Ricon 130MA13", "Ricon 130MA20", "Ricon 131MA5", "Ricon 131MA10", "Ricon 131MA17", "Ricon 131MA20", "Ricon 184MA6" (anhydride group-containing polybutadiene), "GQ-1000" (hydroxyl and carboxyl group-introduced polybutadiene), "G-1000", "G-2000", "G-3000" (polybutadiene with hydroxyl groups on both ends), "GI-1000", "GI- 2000", "GI-3000" (hydrogenated polybutadiene at both ends), Daicel's "PB3600", "PB4700" (polybutadiene skeleton epoxy compound), "Epofriend A1005", "Epofriend A1010", "Epofriend A1020" (epoxy compound of styrene, butadiene and styrene block copolymer), "FCA-061L" (hydrogenated polybutadiene skeleton epoxy compound) manufactured by Nagase ChemteX Corporation, "R-45EPT" (polybutadiene skeleton epoxy compound), etc. mentioned.

Examples of preferred polybutadiene resins include linear polyimide butadiene resins made from hydroxyl group-terminated polybutadiene, diisocyanate compounds and polybasic acids or their anhydrides (Japanese Patent Application Laid-Open No. 2006-37083, International Publication No. 2008/153208 Polyimide described in ) is also included. The polybutadiene structure content of the polyimide-butadiene resin is preferably 60% to 95% by mass, more preferably 75% to 85% by mass. Details of the polyimide-butadiene resin can be referred to in JP-A-2006-37083 and WO 2008/153208, the contents of which are incorporated herein.

The number average molecular weight of the hydroxyl group-terminated polybutadiene, which is the starting material for the polyimide-butadiene resin, is preferably 500 to 5,000, more preferably 1,000 to 3,000, from the viewpoint of exhibiting the desired effects of the present invention. The hydroxyl group-terminated polybutadiene preferably has a hydroxyl group equivalent weight of 250 to 1,250 from the viewpoint of exhibiting the desired effects of the present invention.

Examples of diisocyanate compounds used as raw materials for the polyimide-butadiene resin include aromatic diisocyanates such as toluene-2,4-diisocyanate, toluene-2,6-diisocyanate, xylylene diisocyanate and diphenylmethane diisocyanate; aliphatic diisocyanates such as hexamethylene diisocyanate. ; and alicyclic diisocyanates such as isophorone diisocyanate. Among these, aromatic diisocyanates are preferred, and toluene-2,4-diisocyanate is more preferred.

Examples of polybasic acids or anhydrides thereof as raw materials for the polyimide-butadiene resin include ethylene glycol bis-trimellitic acid, pyromellitic acid, benzophenonetetracarboxylic acid, biphenyltetracarboxylic acid, naphthalenetetracarboxylic acid, 5-(2,5 -dioxotetrahydrofuryl)-3-methyl-cyclohexene-1,2-dicarboxylic acid, 3,3′-4,4′-diphenylsulfonetetracarboxylic acid and other tetrabasic acids and their anhydrides, trimellitic acid, Tribasic acids such as cyclohexanetricarboxylic acid and their anhydrides, 1,3,3a,4,5,9b-hexahydro-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphtho(1,2- C) Furan-1,3-dione and the like.

The polyrotaxane resin is a resin having a structure having a plurality of cyclic molecules, a linear axial molecule enclosed so as to penetrate the cyclic molecule, and a blocking group blocking the end of the axial molecule to prevent the cyclic molecule from coming off. is. The number of cyclic molecules (inclusion amount) in the polyrotaxane resin is not particularly limited as long as the number of cyclic molecules is two or more. When the maximum clathrate of the cyclic molecule in one axial molecule (maximum clathrate) is 100%, it is preferably 10% or more, more preferably 15% or more, and still more preferably 20%. or more, preferably 90% or less, more preferably 85% or less, and even more preferably 80% or less. The inclusion amount can be determined by the length of the axial molecule and the thickness of the cyclic molecule. For example, when the axial molecule is polyethylene glycol and the cyclic molecule is an α-cyclodextrin molecule, the maximum inclusion amount has been determined experimentally (see Macromolecules 1993, 26, 5698-5703).

As the axial molecule in the polyrotaxane resin, a linear molecule having a molecular weight of 10,000 or more and capable of chemically modifying the end with a blocking group can be used. The term “straight-chain” means a substantially straight chain, and the axial molecule may have a branched chain as long as the cyclic molecule through which the axial molecule penetrates can rotate or move. . Examples of axial molecules include polyvinyl alcohol, polyvinylpyrrolidone, poly(meth)acrylic acid cellulose resin, polyacrylamide, polyethylene oxide, polyethylene glycol, polypropylene glycol, polyvinyl acetal resin, polyvinyl methyl ether, polyamine, polyethyleneimine, and casein. , gelatin, starch, polyolefin, polyester, polyvinyl chloride, polystyrene, acrylonitrile-styrene copolymer, acrylic resin, polycarbonate, polyurethane, polyvinyl butyral, polyisobutylene, polytetrahydrofuran, polyamide, polyimide, polydiene, poly Examples include siloxane, polyurea, polysulfide, polyphosphazene, polyketone, polyphenylene, polyhaloolefin and derivatives thereof. Among these, polyethylene glycol chains are preferably used. Two or more of these may be mixed in the polyrotaxane resin.

The length of the axial molecule is not particularly limited as long as the cyclic molecule can rotate or move. The length of the axial molecule can be expressed using the weight average molecular weight. The weight average molecular weight of the axial molecule is preferably 3,000 or more, more preferably 4,000 or more, still more preferably 5,000 or more, preferably 100,000 or less, more preferably 90,000 or less, and further Preferably it is 85,000 or less. The weight average molecular weight of the axial molecule is the polystyrene-equivalent weight average molecular weight measured by gel permeation chromatography (GPC).

The axial molecule usually has a structure in which a molecule containing a blocking group reacts with the functional groups of a molecule having functional groups at both ends and bonds to the functional groups. As the functional group, for example, an amide group, a hydroxyl group, a carboxyl group, an acrylic group, a methacrylic group, an epoxy group, a vinyl group and the like are preferably mentioned.

The cyclic molecule in the polyrotaxane resin is a cyclic molecule that can be included in a state in which the axial molecule is penetrated, and (E) has at least one reactive group (functional group) so that it can react with the curing agent. any molecule can be used. A cyclic molecule refers to a molecule that is substantially cyclic. It is a concept that includes those having a helical structure that does not overlap. Cyclic molecules include, for example, cyclodextrins, crown ethers, cryptands, macrocyclic amines, calixarenes, cyclophanes and the like. Among these, cyclodextrins are preferred. Two or more of these may be mixed in the polyrotaxane resin.

Cyclodextrins include, for example, α-cyclodextrin, β-cyclodextrin, γ-cyclodextrin, dimethylcyclodextrin, glucosylcyclodextrin, and derivatives or modified products thereof.

The cyclic molecules preferably contain reactive groups. Examples of the reactive group include hydroxyl group, carboxyl group, acrylic group, methacrylic group, epoxy group, vinyl group, etc. Among them, hydroxyl group is preferred. When the cyclic molecules have reactive groups, the cyclic molecules or the polyrotaxane resin and the thermosetting resin can be crosslinked via the curing agent. Also, the reactive group of one cyclic molecule and the reactive group of the other cyclic molecule may be crosslinked. One reactive group may be used alone, or two or more reactive groups may be used.

The reactive group need not be directly attached to the cyclic molecule. For example, when the cyclic molecule is cyclodextrin, the hydroxyl group present in the cyclodextrin itself is a reactive group, and when a hydroxypropyl group is added to the hydroxyl group, the hydroxyl group of the hydroxypropyl group is also a reactive group. Furthermore, when ring-opening polymerization of ε-caprolactone is carried out via the hydroxyl group of the hydroxypropyl group and a caprolactone chain is present, the hydroxyl group located at the end opposite to the polyester moiety in the caprolactone chain is also a reactive group.

A cyclic molecule may have one reactive group or two or more reactive groups per cyclic molecule.

The weight average molecular weight of the cyclic molecule is preferably 5,000 or more, more preferably 6,000 or more, still more preferably 7,000 or more, preferably 1,500,000 or less, more preferably 1,400, 000 or less, more preferably 1,350,000 or less. The weight average molecular weight of the cyclic molecule is the polystyrene equivalent weight average molecular weight measured by gel permeation chromatography (GPC).

The blocking group in the polyrotaxane resin is not particularly limited as long as it has a bulky structure such that the cyclic molecule does not come off. The blocking group includes, for example, a cyclodextrin group, adamantane group, dinitrophenyl group, trityl group and the like. Among them, an adamantane group is preferred. These may be contained singly or in combination of two or more in the polyrotaxane resin.

The weight average molecular weight of the entire polyrotaxane resin is preferably 10,000 or more, more preferably 15,000 or more, still more preferably 20,000 or more, and preferably 1,500,000 or less, more preferably 1,500,000 or less. 400,000 or less, more preferably 1,350,000 or less. The weight average molecular weight of the polyrotaxane resin is the polystyrene equivalent weight average molecular weight measured by gel permeation chromatography (GPC).

The hydroxyl value of the polyrotaxane resin is preferably 45 mgKOH/g or more, more preferably 50 mgKOH/g or more, still more preferably 55 mgKOH/g or more, preferably 120 mgKOH/g or less, more preferably 115 mgKOH/g or less, and still more preferably. is 110 mgKOH/g or less. A hydroxyl value can be measured according to JIS K0070.

The polyrotaxane resin may be liquid, but is preferably particulate and contained in the resin composition. The particulate polyrotaxane resin is easy to disperse and can further reduce the viscosity of the resin composition.

The average particle diameter of the particulate polyrotaxane resin is preferably 100 nm or more, more preferably 500 nm or more, still more preferably 800 nm or more, preferably 50,000 nm or less, more preferably 40,000 nm or less, further preferably 30,000 nm or less. 000 nm or less. The particulate polyrotaxane resin having such an average particle diameter is easily dispersed uniformly in the resin composition, and the viscosity of the resin composition is easily lowered. The average particle size can be measured by the same method as for measuring the average particle size of the inorganic filler.

The polyrotaxane resin can be synthesized, for example, by the methods described in International Publication No. 01/83566, Japanese Patent Application Laid-Open No. 2005-154675, Japanese Patent No. 4482633, and the like.

A commercially available product may be used as the polyrotaxane resin. As commercially available products, for example, "SH2400B-007", "SH1310P", and "Celm Super Polymer A1000" manufactured by Advanced Soft Materials Co., Ltd. can be used. These may be used individually by 1 type, and may be used in combination of 2 or more type.

A polyimide resin is a resin having an imide bond in a repeating unit. A polyimide resin can generally include a resin obtained by an imidation reaction between a diamine compound and a tetracarboxylic anhydride. Polyimide resins also include modified polyimide resins such as siloxane-modified polyimide resins.

Polyimide resin, for example, formula (1):

[In the formula, X ¹ represents a tetravalent group obtained by removing two -CO-O-CO- from a tetracarboxylic dianhydride, and X ² is a diamine compound removing two -NH ₂ represents a divalent group, and n represents an integer of 2 or more. ]
can include structures represented by

The diamine compound for preparing the polyimide resin is not particularly limited, and examples thereof include aliphatic diamine compounds and aromatic diamine compounds.

Examples of aliphatic diamine compounds include 1,2-ethylenediamine, 1,2-diaminopropane, 1,3-diaminopropane, 1,4-diaminobutane, 1,6-hexamethylenediamine, and 1,5-diaminopentane. , 1,10-diaminodecane and other linear aliphatic diamine compounds; 1,2-diamino-2-methylpropane, 2,3-diamino-2,3-butane, and 2-methyl-1,5- Branched aliphatic diamine compounds such as diaminopentane; 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, 1,4-diaminocyclohexane, 4,4′-methylenebis(cyclohexyl) alicyclic diamine compounds such as amines); dimer acid-type diamines (hereinafter also referred to as "dimer diamines"), and the like.

A dimer acid-type diamine is a diamine compound obtained by substituting _two terminal carboxylic acid groups (--COOH) of a dimer _acid with an aminomethyl group (--CH.sub.2--NH.sub.2) or an amino group ( _--NH.sub.2 ). means. Dimer acid is a known compound obtained by dimerizing an unsaturated fatty acid (preferably having 11 to 22 carbon atoms, particularly preferably having 18 carbon atoms), and its industrial production process is almost Standardized. Among dimer acids, dimer acids having 36 carbon atoms obtained by dimerizing unsaturated fatty acids having 18 carbon atoms such as oleic acid and linoleic acid, which are inexpensive and readily available, are readily available. In addition, the dimer acid may contain any amount of monomeric acid, trimeric acid, other polymerized fatty acids, etc. depending on the production method, the degree of purification, and the like. Further, although double bonds remain after the polymerization reaction of unsaturated fatty acids, in the present specification, dimer acids also include hydrogenated products obtained by further hydrogenating to reduce the degree of unsaturation. Dimer acid-type diamines are commercially available, and examples thereof include PRIAMINE 1073, PRIAMINE 1074, and PRIAMINE 1075 manufactured by Croda Japan, Versamin 551 and Versamin 552 manufactured by Cognis Japan, and the like.

Examples of aromatic diamine compounds include phenylenediamine compounds, naphthalenediamine compounds, and dianiline compounds.

A phenylenediamine compound means a compound consisting of a benzene ring having two amino groups, and the benzene ring may optionally have 1 to 3 substituents. The substituents here are not particularly limited. Specific examples of phenylenediamine compounds include 1,4-phenylenediamine, 1,2-phenylenediamine, 1,3-phenylenediamine, 2,4-diaminotoluene, 2,6-diaminotoluene, 3,5-diamino biphenyl, 2,4,5,6-tetrafluoro-1,3-phenylenediamine and the like.

A naphthalenediamine compound means a compound consisting of a naphthalene ring having two amino groups, and the naphthalene ring herein may optionally have 1 to 3 substituents. The substituents here are not particularly limited. Specific examples of naphthalenediamine compounds include 1,5-diaminonaphthalene, 1,8-diaminonaphthalene, 2,6-diaminonaphthalene, and 2,3-diaminonaphthalene.

A dianiline compound means a compound containing two aniline structures in the molecule, and two benzene rings in the two aniline structures each further optionally have 1 to 3 substituents. can. The substituents here are not particularly limited. The two aniline structures in the dianiline compound are a direct bond and/or 1 to 100 (preferably 1 to 50, more preferably 1 to 20) selected from carbon atoms, oxygen atoms, sulfur atoms and nitrogen atoms. can be linked through one or two divalent linking groups having a backbone atom of Dianiline compounds also include those in which two aniline structures are bonded at two positions.

Specific examples of the "divalent linking group" in the dianiline compound include -NHCO-, -CONH-, -OCO-, -COO-, -CH ₂ -, -CH ₂ CH ₂ -, and -CH ₂ CH ₂ CH ₂ —, —CH ₂ CH ₂ CH ₂ CH ₂ —, —CH ₂ CH ₂ CH ₂ CH ₂ CH ₂ —, —CH(CH ₃ )—, —C(CH ₃ ) ₂ —, —C(CF ₃ ) ₂ -, -CH=CH-, -O-, -S-, -CO-, -SO ₂ -, -NH-, -Ph-, -Ph-Ph-, -C(CH ₃ ) ₂ -Ph -C(CH ₃ ) ₂ -, -O-Ph-O-, -O-Ph-Ph-O-, -O-Ph-SO ₂ -Ph-O-, -O-Ph-C(CH ₃ ) ₂ -Ph-O-, -C( _CH3 ) ₂ -Ph-C( _CH3 ) _2- ,

(In the formula, * indicates a binding site.)
etc. "Ph" represents a 1,4-phenylene group, a 1,3-phenylene group or a 1,2-phenylene group.

Specific dianiline compounds include 4,4'-diamino-2,2'-ditrifluoromethyl-1,1'-biphenyl, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 3, 3'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfide, 4-aminophenyl 4-aminobenzoate, 1,3-bis(3-aminophenoxy)benzene, 1,3 -bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 2,2-bis(4-aminophenyl)propane, 4,4'-(hexafluoroisopropylidene)dianiline, 2 , 2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, α,α-bis[4-(4-aminophenoxy ) phenyl]-1,3-diisopropylbenzene, α,α-bis[4-(4-aminophenoxy)phenyl]-1,4-diisopropylbenzene, 4,4′-(9-fluorenylidene)dianiline, 2,2 -bis(3-methyl-4-aminophenyl)propane, 2,2-bis(3-methyl-4-aminophenyl)benzene, 4,4'-diamino-3,3'-dimethyl-1,1'- biphenyl, 4,4'-diamino-2,2'-dimethyl-1,1'-biphenyl, 9,9'-bis(3-methyl-4-aminophenyl)fluorene, 5-(4-aminophenoxy)- 3-[4-(4-aminophenoxy)phenyl]-1,1,3-trimethylindane, 5-amino-1,1'-biphenyl-2-yl 4-aminobenzoate and the like, preferably 5-(4-aminophenoxy)-3-[4-(4-aminophenoxy)phenyl]-1,1,3-trimethylindane and 5-amino-1,1′-biphenyl-2-4-aminobenzoate - is yl.

A commercially available diamine compound may be used, or one synthesized by a known method may be used. A diamine compound may be used individually by 1 type, and may be used in combination of 2 or more type.

The tetracarboxylic anhydride for preparing the polyimide resin is not particularly limited, but examples thereof include aromatic tetracarboxylic dianhydride and aliphatic tetracarboxylic dianhydride.

Examples of the aromatic tetracarboxylic dianhydride include benzenetetracarboxylic dianhydride, naphthalenetetracarboxylic dianhydride, anthracenetetracarboxylic dianhydride, diphthalic dianhydride and the like, preferably It is diphthalic dianhydride.

Benzenetetracarboxylic dianhydride means the dianhydride of benzene having 4 carboxy groups, and further, the benzene ring herein may optionally have 1-3 substituents. Here, the substituent is not particularly limited. Specific examples of benzenetetracarboxylic dianhydride include pyromellitic dianhydride and 1,2,3,4-benzenetetracarboxylic dianhydride.

Naphthalenetetracarboxylic dianhydride means a dianhydride of naphthalene having 4 carboxy groups, and furthermore, the naphthalene ring herein may optionally have 1 to 3 substituents. Here, the substituent is not particularly limited. Specific examples of the naphthalenetetracarboxylic dianhydride include 1,4,5,8-naphthalenetetracarboxylic dianhydride and 2,3,6,7-naphthalenetetracarboxylic dianhydride.

Anthracenetetracarboxylic dianhydride means an anthracene dianhydride having four carboxy groups, and the anthracene ring herein may optionally have 1 to 3 substituents. Here, the substituent is not particularly limited. Specific examples of anthracenetetracarboxylic dianhydride include 2,3,6,7-anthracenetetracarboxylic dianhydride and the like.

Diphthalic dianhydride means a compound containing two phthalic anhydrides in the molecule, and two benzene rings in each of the two phthalic anhydrides are optionally 1 to 3 It can have substituents. Here, the substituent is not particularly limited. The two phthalic anhydrides in the diphthalic dianhydride are a direct bond or 1 to 100 (preferably 1 to 50, more preferably 1 to 20) selected from carbon atoms, oxygen atoms, sulfur atoms and nitrogen atoms. ) skeleton atoms via a divalent linking group.

Divalent linking groups are specifically -CH ₂ -, -CH ₂ CH ₂ -, -CH ₂ CH ₂ CH ₂ -, -CH ₂ CH ₂ CH ₂ CH ₂ -, -CH ₂ CH ₂ CH ₂ CH ₂ CH ₂ -, -CH(CH ₃ )-, -C(CH ₃ ) ₂ -, -O-, -CO-, -SO ₂ -, -Ph-, -O-Ph-O-, -O -Ph-SO ₂ -Ph-O-, -O-Ph-C(CH ₃ ) ₂ -Ph-O- and the like.

Specific examples of diphthalic dianhydride include 3,3′,4,4′-benzophenonetetracarboxylic dianhydride, 3,3′,4,4′-diphenyl ether tetracarboxylic dianhydride, 3, 3′,4,4′-diphenylsulfonetetracarboxylic dianhydride, 3,3′,4,4′-biphenyltetracarboxylic dianhydride, 2,2′,3,3′-biphenyltetracarboxylic dianhydride anhydride, 2,3,3',4'-biphenyltetracarboxylic dianhydride, 2,3,3',4'-benzophenonetetracarboxylic dianhydride, 2,3,3',4'-diphenyl ether Tetracarboxylic dianhydride, 2,3,3′,4′-diphenylsulfonetetracarboxylic dianhydride 2,2′-bis(3,4-dicarboxyphenoxyphenyl)sulfone dianhydride, methylene-4, 4'-diphthalic dianhydride, 1,1-ethynylidene-4,4'-diphthalic dianhydride, 2,2-propylidene-4,4'-diphthalic dianhydride, 1,2-ethylene-4 ,4'-diphthalic dianhydride, 1,3-trimethylene-4,4'-diphthalic dianhydride, 1,4-tetramethylene-4,4'-diphthalic dianhydride, 1,5-penta Methylene-4,4'-diphthalic dianhydride, 1,3-bis(3,4-dicarboxyphenyl)benzene dianhydride, 1,4-bis(3,4-dicarboxyphenyl)benzene dianhydride , 1,3-bis(3,4-dicarboxyphenoxy)benzene dianhydride, 1,4-bis(3,4-dicarboxyphenoxy)benzene dianhydride, 2,2-bis(2,3-di carboxyphenyl)propane dianhydride, 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride, 4,4'-(4,4'-isopropylidenediphenoxy)bisphthalic dianhydride, etc. mentioned.

Specific examples of aliphatic tetracarboxylic dianhydrides include 1,2,3,4-cyclobutanetetracarboxylic dianhydride, cyclopentanetetracarboxylic dianhydride, cyclohexane-1,2,3,4- tetracarboxylic dianhydride, cyclohexane-1,2,4,5-tetracarboxylic dianhydride, 3,3',4,4'-bicyclohexyltetracarboxylic dianhydride, carbonyl-4,4'- Bis (cyclohexane-1,2-dicarboxylic acid) dianhydride, methylene-4,4'-bis (cyclohexane-1,2-dicarboxylic acid) dianhydride, 1,2-ethylene-4,4'-bis ( cyclohexane-1,2-dicarboxylic acid) dianhydride, oxy-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, thio-4,4'-bis(cyclohexane-1,2- dicarboxylic acid) dianhydride, sulfonyl-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride and the like.

A commercially available tetracarboxylic dianhydride may be used, or a tetracarboxylic dianhydride synthesized by a known method or a method analogous thereto may be used. Tetracarboxylic dianhydrides may be used singly or in combination of two or more.

The content of the structure derived from the aromatic tetracarboxylic dianhydride with respect to the total structure derived from the tetracarboxylic dianhydride constituting the polyimide resin is preferably 10 mol% or more, and is 30 mol% or more. more preferably 50 mol% or more, still more preferably 70 mol% or more, even more preferably 90 mol% or more, and particularly preferably 100 mol% .

The weight average molecular weight of the polyimide resin is preferably 1,000 to 100,000.

A maleimide resin having a dimer acid skeleton is, for example, a bismaleimide compound having a hydrocarbon skeleton derived from a dimer acid. The maleimide resin having a dimer acid skeleton is, for example, a bismaleimide compound obtained by imidizing at least a dimer acid-type diamine and maleic anhydride, and further, a dimer acid-type diamine and a tetracarboxylic dianhydride. Bismaleimide compounds obtained by imidization reaction with maleic anhydride are included.

A maleimide resin having a dimer acid skeleton has, for example, the following formula (2):

[In the formula, Y ¹ and Y ³ each independently represent a divalent group excluding two —NH ₂ from a dimer acid diamine, and Y ² represents two from a tetracarboxylic dianhydride. represents a tetravalent group excluding -CO-O-CO-, and m represents 0 or 1. ]
is a bismaleimide compound represented by

Specific examples of the maleimide resin having a dimer acid skeleton include "BMI689", "BMI1500", "BMI1700", and "BMI3000" manufactured by DESIGNER MOLECULES. These may be used individually by 1 type, and may be used in combination of 2 or more types.

(D) The content of the adhesive softening agent is not particularly limited, but from the viewpoint of obtaining a cured product with more excellent flexibility, when the non-volatile component in the resin composition is 100% by mass , preferably 1% by mass or more, more preferably 5% by mass or more, still more preferably 10% by mass or more, and particularly preferably 15% by mass or more. (D) The upper limit of the content of the adhesive softening agent is not particularly limited, but when the non-volatile component in the resin composition is 100% by mass, it is preferably 50% by mass or less, more preferably 40% by mass. % by mass or less, more preferably 30% by mass or less, particularly preferably 25% by mass or less.

<(E) Curing agent>
The resin composition of the present invention may contain (E) a curing agent as an optional component. (E) The curing agent has a function of curing (A) the thermosetting resin.

(E) The curing agent is not particularly limited, but when the thermosetting resin (A) is an epoxy resin, for example, a phenolic curing agent, a naphthol curing agent, an acid anhydride curing agent, an active Ester-based curing agents, benzoxazine-based curing agents, cyanate ester-based curing agents, and carbodiimide-based curing agents are included, and phenol-based curing agents, naphthol-based curing agents, and active ester-based curing agents are preferred. (E) The curing agent preferably contains an active ester curing agent. The curing agent may be used singly or in combination of two or more.

As the phenolic curing agent and the naphtholic curing agent, a phenolic curing agent having a novolac structure or a naphtholic curing agent having a novolac structure is preferable from the viewpoint of heat resistance and water resistance. From the viewpoint of adhesion to adherends, a nitrogen-containing phenolic curing agent or a nitrogen-containing naphthol curing agent is preferable, and a triazine skeleton-containing phenolic curing agent or a triazine skeleton-containing naphthol curing agent is more preferable. Among them, a triazine skeleton-containing phenol novolak resin is preferable from the viewpoint of highly satisfying heat resistance, water resistance, and adhesion. Specific examples of phenol-based curing agents and naphthol-based curing agents include "MEH-7700", "MEH-7810" and "MEH-7851" manufactured by Meiwa Kasei Co., Ltd., "NHN" manufactured by Nippon Kayaku Co., Ltd., "CBN", "GPH", Nippon Steel & Sumikin Chemical Co., Ltd. "SN-170", "SN-180", "SN-190", "SN-475", "SN-485", "SN-495", "SN-375", "SN-395", DIC "LA-7052", "LA-7054", "LA-3018", "LA-3018-50P", "LA-1356", "TD2090" ”, “TD-2090-60M” and the like.

Acid anhydride curing agents include curing agents having one or more acid anhydride groups in one molecule. Specific examples of acid anhydride curing agents include phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylnadic anhydride, and hydrogenated methylnadic acid. anhydride, trialkyltetrahydrophthalic anhydride, dodecenylsuccinic anhydride, 5-(2,5-dioxotetrahydro-3-furanyl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, trianhydride mellitic acid, pyromellitic anhydride, benzophenonetetracarboxylic dianhydride, biphenyltetracarboxylic dianhydride, naphthalenetetracarboxylic dianhydride, oxydiphthalic dianhydride, 3,3'-4,4'- Diphenylsulfonetetracarboxylic dianhydride, 1,3,3a,4,5,9b-hexahydro-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphtho[1,2-C]furan-1 , 3-dione, ethylene glycol bis(anhydrotrimellitate), polymer-type acid anhydrides such as styrene/maleic acid resin obtained by copolymerizing styrene and maleic acid. Commercially available acid anhydride curing agents include "HNA-100" and "MH-700" manufactured by Shin Nippon Rika.

The active ester-based curing agent is not particularly limited, but generally contains an ester group with high reaction activity such as phenol esters, thiophenol esters, N-hydroxyamine esters, esters of heterocyclic hydroxy compounds in one molecule. A compound having two or more is preferably used. The active ester curing agent is preferably obtained by a condensation reaction between a carboxylic acid compound and/or a thiocarboxylic acid compound and a hydroxy compound and/or a thiol compound. In particular, from the viewpoint of improving heat resistance, an active ester curing agent obtained from a carboxylic acid compound and a hydroxy compound is preferred, and an active ester curing agent obtained from a carboxylic acid compound and a phenol compound and/or a naphthol compound is more preferred. Examples of carboxylic acid compounds include benzoic acid, acetic acid, succinic acid, maleic acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, and pyromellitic acid. Examples of phenol compounds or naphthol compounds include hydroquinone, resorcinol, bisphenol A, bisphenol F, bisphenol S, phenolphthalin, methylated bisphenol A, methylated bisphenol F, methylated bisphenol S, phenol, o-cresol, m- cresol, p-cresol, catechol, α-naphthol, β-naphthol, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, phloroglucine, Benzenetriol, dicyclopentadiene-type diphenol compound, phenol novolak, and the like. Here, the term "dicyclopentadiene-type diphenol compound" refers to a diphenol compound obtained by condensing one molecule of dicyclopentadiene with two molecules of phenol.

Specifically, an active ester compound containing a dicyclopentadiene type diphenol structure, an active ester compound containing a naphthalene structure, an active ester compound containing an acetylated product of phenol novolac, and an active ester compound containing a benzoylated product of phenol novolak are preferred. Among them, an active ester compound containing a naphthalene structure and an active ester compound containing a dicyclopentadiene-type diphenol structure are more preferable. "Dicyclopentadiene-type diphenol structure" represents a divalent structural unit consisting of phenylene-dicyclopentalene-phenylene.

Commercially available active ester curing agents include, as active ester compounds containing a dicyclopentadiene type diphenol structure, "EXB9451", "EXB9460", "EXB9460S", "HPC-8000", "HPC-8000H", " HPC-8000-65T", "HPC-8000H-65TM", "EXB-8000L", "EXB-8000L-65M", "EXB-8000L-65TM" (manufactured by DIC); active ester compounds containing a naphthalene structure "EXB9416-70BK", "EXB-8150-65T" (manufactured by DIC); "DC808" as an active ester compound containing an acetylated phenol novolak (manufactured by Mitsubishi Chemical); an active ester compound containing a benzoylated phenol novolak "YLH1026" (manufactured by Mitsubishi Chemical Corporation); "DC808" (manufactured by Mitsubishi Chemical Corporation) as an active ester curing agent that is an acetylated product of phenol novolak; "YLH1026" as an active ester curing agent that is a benzoylated product of phenol novolak. (manufactured by Mitsubishi Chemical Corporation), "YLH1030" (manufactured by Mitsubishi Chemical Corporation), "YLH1048" (manufactured by Mitsubishi Chemical Corporation);

Specific examples of benzoxazine-based curing agents include "JBZ-OP100D" and "ODA-BOZ" manufactured by JFE Chemical; "HFB2006M" manufactured by Showa Polymer Co., Ltd.; Examples include "Fa".

Examples of cyanate ester curing agents include bisphenol A dicyanate, polyphenolcyanate (oligo(3-methylene-1,5-phenylenecyanate)), 4,4'-methylenebis(2,6-dimethylphenylcyanate), 4, 4′-ethylidene diphenyl dicyanate, hexafluorobisphenol A dicyanate, 2,2-bis(4-cyanate)phenylpropane, 1,1-bis(4-cyanatophenylmethane), bis(4-cyanate-3,5- Difunctional cyanate resins such as dimethylphenyl)methane, 1,3-bis(4-cyanatophenyl-1-(methylethylidene))benzene, bis(4-cyanatophenyl)thioether, and bis(4-cyanatophenyl)ether, Polyfunctional cyanate resins derived from phenol novolak, cresol novolak, etc., and prepolymers obtained by partially triazine-forming these cyanate resins. Specific examples of cyanate ester curing agents include "PT30" and "PT60" (both phenol novolac type polyfunctional cyanate ester resins), "BA230" and "BA230S75" (part of bisphenol A dicyanate) manufactured by Lonza Japan Co., Ltd. or a prepolymer that is entirely triazined to form a trimer), and the like.

Specific examples of carbodiimide curing agents include "V-03" and "V-07" manufactured by Nisshinbo Chemical Co., Ltd., and the like.

When the resin composition contains (E) a curing agent, the amount ratio of (A) the thermosetting resin and (E) the curing agent is [total number of reactive groups of the thermosetting resin]:[reaction of the curing agent total number of groups], the range is preferably 1:0.2 to 1:2, more preferably 1:0.3 to 1:1.5, and 1:0.4 to 1:1.2. More preferred. Here, the reactive group of the curing agent is an active hydroxyl group, an active ester group, or the like, and varies depending on the type of curing agent. The reactive group of the thermosetting resin is an epoxy group or the like, and differs depending on the type of the thermosetting resin.

When the resin composition contains (E) a curing agent, the content is not particularly limited, but is preferably 0.1% by mass when the non-volatile component in the resin composition is 100% by mass. Above, more preferably 1% by mass or more, still more preferably 3% by mass or more, and particularly preferably 4% by mass or more. (E) The upper limit of the content of the curing agent is not particularly limited, but when the non-volatile component in the resin composition is 100% by mass, it is preferably 30% by mass or less, more preferably 20% by mass or less. , more preferably 15% by mass or less, and particularly preferably 10% by mass or less.

<(F) Curing accelerator>
The resin composition of the present invention may contain (F) a curing accelerator as an optional component. (F) The curing accelerator has a function of accelerating the curing speed of the thermosetting resin (A).

(F) The curing accelerator is not particularly limited, but when the thermosetting resin (A) is an epoxy resin, for example, a phosphorus-based curing accelerator, an amine-based curing accelerator, an imidazole-based curing accelerator , guanidine-based curing accelerators, metal-based curing accelerators, and the like. Among them, phosphorus-based curing accelerators, amine-based curing accelerators, imidazole-based curing accelerators, and metal-based curing accelerators are preferable, and amine-based curing accelerators are more preferable. The curing accelerator may be used singly or in combination of two or more.

Phosphorus curing accelerators include, for example, triphenylphosphine, phosphonium borate compounds, tetraphenylphosphonium tetraphenylborate, n-butylphosphonium tetraphenylborate, tetrabutylphosphonium decanoate, (4-methylphenyl)triphenylphosphonium thiocyanate. , tetraphenylphosphonium thiocyanate, butyltriphenylphosphonium thiocyanate, and the like.

Examples of amine curing accelerators include trialkylamines such as triethylamine and tributylamine, 4-dimethylaminopyridine (DMAP), benzyldimethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, 1, 8-diazabicyclo(5,4,0)-undecene, etc., and 4-dimethylaminopyridine is preferred.

Examples of imidazole curing accelerators include 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazolium trimellitate, 1-cyanoethyl- 2-phenylimidazolium trimellitate, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-undecyl imidazolyl-(1′)]-ethyl-s-triazine, 2,4-diamino-6-[2′-ethyl-4′-methylimidazolyl-(1′)]-ethyl-s-triazine, 2,4- Diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isocyanurate, 2-phenylimidazole isocyanurate, 2-phenyl-4,5-dihydroxymethylimidazole, 2- Phenyl-4-methyl-5-hydroxymethylimidazole, 2,3-dihydro-1H-pyrrolo[1,2-a]benzimidazole, 1-dodecyl-2-methyl-3-benzylimidazolium chloride, 2-methylimidazoline , 2-phenylimidazoline and other imidazole compounds, and adducts of imidazole compounds and epoxy resins.

As the imidazole-based curing accelerator, a commercially available product may be used, such as "P200-H50" manufactured by Mitsubishi Chemical Corporation.

Guanidine curing accelerators include, for example, dicyandiamide, 1-methylguanidine, 1-ethylguanidine, 1-cyclohexylguanidine, 1-phenylguanidine, 1-(o-tolyl)guanidine, dimethylguanidine, diphenylguanidine, trimethylguanidine, Tetramethylguanidine, Pentamethylguanidine, 1,5,7-triazabicyclo[4.4.0]dec-5-ene, 7-methyl-1,5,7-triazabicyclo[4.4.0] Dec-5-ene, 1-methylbiguanide, 1-ethylbiguanide, 1-n-butylbiguanide, 1-n-octadecylbiguanide, 1,1-dimethylbiguanide, 1,1-diethylbiguanide, 1-cyclohexylbiguanide, 1 -allylbiguanide, 1-phenylbiguanide, 1-(o-tolyl)biguanide and the like.

Metal-based curing accelerators include, for example, organometallic complexes or organometallic salts of metals such as cobalt, copper, zinc, iron, nickel, manganese, and tin. Specific examples of organometallic complexes include organocobalt complexes such as cobalt (II) acetylacetonate and cobalt (III) acetylacetonate, organocopper complexes such as copper (II) acetylacetonate, and zinc (II) acetylacetonate. organic zinc complexes such as iron (III) acetylacetonate; organic nickel complexes such as nickel (II) acetylacetonate; organic manganese complexes such as manganese (II) acetylacetonate; Examples of organic metal salts include zinc octoate, tin octoate, zinc naphthenate, cobalt naphthenate, tin stearate, and zinc stearate.

When the resin composition contains (F) a curing accelerator, the content is not particularly limited, but when the non-volatile component in the resin composition is 100% by mass, it is preferably 0.001 mass % or more, more preferably 0.01 mass % or more, still more preferably 0.05 mass % or more, and particularly preferably 0.1 mass % or more. (F) The upper limit of the content of the curing accelerator is not particularly limited, but when the non-volatile component in the resin composition is 100% by mass, it is preferably 2% by mass or less, more preferably 1% by mass. Below, more preferably 0.5% by mass or less, particularly preferably 0.3% by mass or less.

<(G) Other Additives>
The resin composition of the present invention may further contain optional additives as non-volatile components. Examples of such additives include thermoplastic resins such as phenoxy resins, polyvinyl acetal resins, polyolefin resins, polysulfone resins, polyethersulfone resins, polyphenylene ether resins, polycarbonate resins, polyetheretherketone resins, and polyester resins; Organometallic compounds such as copper compounds, organozinc compounds, and organocobalt compounds; coloring agents such as phthalocyanine blue, phthalocyanine green, iodine green, diazo yellow, crystal violet, titanium oxide, and carbon black; hydroquinone, catechol, pyrogallol, phenothiazine, etc. polymerization inhibitor; leveling agents such as siloxane; thickeners such as bentone and montmorillonite; UV absorbers such as triazole-based UV absorbers; adhesion improvers such as urea silane; adhesion-imparting agents such as silane coupling agents, triazole-based adhesion promoters, tetrazole-based adhesion promoters, triazine-based adhesion promoters, etc. agents; antioxidants such as hindered phenol antioxidants and hindered amine antioxidants; fluorescent brighteners such as stilbene derivatives; ), nitrogen-based flame retardants (eg, melamine sulfate), halogen-based flame retardants, and inorganic flame retardants (eg, antimony trioxide). One of the additives may be used alone, or two or more of them may be used in combination at an arbitrary ratio. (G) The content of other additives can be appropriately set by those skilled in the art.

<(H) Organic solvent>
The resin composition of the present invention may further contain an arbitrary organic solvent as a volatile component in addition to the non-volatile component described above. As the organic solvent (H), as long as it is capable of dissolving at least a part of the non-volatile components, any known organic solvent can be appropriately used, and the type thereof is not particularly limited. Examples of (H) organic solvents include ketone-based solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ester solvents such as butyrolactone; ether solvents such as tetrahydropyran, tetrahydrofuran, 1,4-dioxane, diethyl ether, diisopropyl ether, dibutyl ether, and diphenyl ether; alcohol solvents such as methanol, ethanol, propanol, butanol, and ethylene glycol; Ether ester solvents such as 2-ethoxyethyl acetate, propylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl diglycol acetate, γ-butyrolactone, methyl methoxypropionate; methyl lactate, ethyl lactate, 2-hydroxyisobutyric acid ester alcohol solvents such as methyl; ether alcohol solvents such as 2-methoxypropanol, 2-methoxyethanol, 2-ethoxyethanol, propylene glycol monomethyl ether, diethylene glycol monobutyl ether (butyl carbitol); N,N-dimethylformamide, Amide solvents such as N,N-dimethylacetamide and N-methyl-2-pyrrolidone; sulfoxide solvents such as dimethylsulfoxide; nitrile solvents such as acetonitrile and propionitrile; hexane, cyclopentane, cyclohexane, methylcyclohexane and the like Aliphatic hydrocarbon solvents; aromatic hydrocarbon solvents such as benzene, toluene, xylene, ethylbenzene, trimethylbenzene, and the like can be mentioned. The organic solvent may be used singly or in combination of two or more at any ratio.

(H) The content of the organic solvent is preferably 30% by mass or more, more preferably 30% by mass or more, from the viewpoint of efficient drying of the resin composition. can be set to be 35% by mass or more, more preferably 40% by mass or more, and particularly preferably 45% by mass or more. The upper limit of the solid content is not particularly limited, but from the viewpoint of handleability of the resin composition, it is preferably 100% by mass or less, more preferably 95% by mass or less, still more preferably 92% by mass or less, especially Preferably, it may be 90% by mass or less.

<Method for producing resin composition>
The resin composition of the present invention is, for example, placed in any reaction vessel (A) a thermosetting resin, (B) an inorganic filler, (C) an organic filler, (D) an adhesive softening agent, and if necessary (E) a curing agent, optionally (F) a curing accelerator, optionally (G) other additives, and optionally (H) an organic solvent, in any order and/or part or It can be prepared by adding all at the same time and mixing. Also, during the process of adding and mixing each component, the temperature can be set appropriately, and heating and/or cooling may be performed temporarily or over time. Moreover, you may stir or shake in the process of adding and mixing each component. In addition, during or after the addition and mixing, the resin composition may be stirred using a stirring device such as a mixer to uniformly disperse.

<Characteristics of resin composition>
Since the resin composition of the present invention contains 5% by mass or more of (C) an organic filler in addition to (A) a thermosetting resin, (D) an adhesive softening agent, and (B) an inorganic filler, The tackiness can be kept low while maintaining excellent flexibility.

Since the resin composition of the present invention contains (D) an adhesive softening agent, it has sufficient flexibility. is set to a load of 2.5 N, a bending angle of 90 degrees, a bending speed of 175 times/minute, and a bending radius of 1.0 mm in accordance with JIS C-5016. , preferably 3,000 times or more, more preferably 5,000 times or more, still more preferably 7,000 times or more, and particularly preferably 8,000 times or more.

The resin composition of the present invention, for example, the starting temperature from 60 ° C. to 200 ° C., the temperature increase rate of 5 ° C./min, the frequency of 1 Hz, the minimum melt viscosity of the resin composition measured under the conditions of 1 deg strain is preferably It can be 40,000 poise or less, preferably 30,000 poise or less, preferably 20,000 poise or less, preferably 10,000 poise or less.

Since the resin composition of the present invention contains (C) an organic filler, for example, the layered resin composition is measured using a probe tack tester with a probe of φ5 mm, a load of 1 kgf/cm ² , and a contact speed of 0.5 mm. / sec, tensile speed 0.5 mm / sec, holding time 10 sec, temperature 80 ° C. The tack force measured is preferably 2.0 N or less, more preferably 1.8 N or less, further preferably 1.7 N or less. , particularly preferably 1.6 N or less.

In addition, the resin composition of the present invention is characterized in that, when the content of (C) the organic filler is 10% by mass or less, void defects are suppressed and pattern embedding properties are more excellent.

<Resin sheet>
The resin sheet of the present invention includes a support and a resin composition layer formed of the resin composition of the present invention provided on the support.

The thickness of the resin composition layer is preferably 200 μm or less, more preferably 150 μm or less, still more preferably 100 μm or less, and particularly preferably 70 μm or less. Although the lower limit of the thickness of the resin composition layer is not particularly limited, it can be usually 1 μm or more, 1.5 μm or more, or 2 μm or more.

Examples of the support include a film made of a plastic material, a metal foil, and a release paper, and a film made of a plastic material and a metal foil are preferable.

When a film made of a plastic material is used as the support, examples of the plastic material include polyethylene terephthalate (hereinafter sometimes abbreviated as "PET") and polyethylene naphthalate (hereinafter sometimes abbreviated as "PEN"). ), polycarbonate (hereinafter sometimes abbreviated as "PC"), acrylic such as polymethyl methacrylate (PMMA), cyclic polyolefin, triacetyl cellulose (TAC), polyether sulfide (PES), polyether ketones, polyimides, and the like. Among them, polyethylene terephthalate and polyethylene naphthalate are preferable, and inexpensive polyethylene terephthalate is particularly preferable.

When a metal foil is used as the support, examples of the metal foil include copper foil and aluminum foil, with copper foil being preferred. As the copper foil, a foil made of a single metal of copper may be used, and a foil made of an alloy of copper and other metals (for example, tin, chromium, silver, magnesium, nickel, zirconium, silicon, titanium, etc.) may be used. may be used.

The support may be subjected to matte treatment, corona treatment, or antistatic treatment on the surface to be bonded to the resin composition layer.

Further, as the support, a support with a release layer having a release layer on the surface to be bonded to the resin composition layer may be used. The release agent used in the release layer of the release layer-attached support includes, for example, one or more release agents selected from the group consisting of alkyd resins, polyolefin resins, urethane resins, and silicone resins. . As the support with a release layer, a commercially available product may be used, for example, "SK-1" manufactured by Lintec Co., Ltd., "SK-1", " AL-5", "AL-7", Toray's "Lumirror T60", Teijin's "Purex", and Unitika's "Unipeel".

The thickness of the support is not particularly limited, but is preferably in the range of 5 μm to 75 μm, more preferably in the range of 10 μm to 60 μm. When a release layer-attached support is used, the thickness of the release layer-attached support as a whole is preferably within the above range.

In one embodiment, the resin sheet may further contain other layers as necessary. Such other layers include, for example, a protective film conforming to the support provided on the surface of the resin composition layer not bonded to the support (that is, the surface opposite to the support). be done. Although the thickness of the protective film is not particularly limited, it is, for example, 1 μm to 40 μm. By laminating the protective film, the surface of the resin composition layer can be prevented from being dusted or scratched.

The resin sheet is formed by coating the resin composition as it is or, for example, a resin varnish prepared by dissolving the resin composition in an organic solvent, onto the support using a die coater or the like, and then drying to form a resin composition layer. It can be manufactured by

Examples of the organic solvent that can be used for coating on the support include the same ones as those mentioned in the explanation of the organic solvent (H) above. An organic solvent may be used individually by 1 type, and may be used in combination of 2 or more type.

Drying may be carried out by a known method such as heating or blowing hot air. The drying conditions are not particularly limited, but the resin composition layer is dried so that the content of the organic solvent is 10% by mass or less, preferably 5% by mass or less. Depending on the boiling point of the organic solvent in the resin composition or resin varnish, for example, when using a resin composition or resin varnish containing 30% by mass to 60% by mass of the organic solvent, the temperature is 50° C. to 150° C. for 3 minutes to 10 minutes. A resin composition layer can be formed by drying for minutes.

The resin sheet can be wound into a roll and stored. When the resin sheet has a protective film, it can be used by peeling off the protective film.

<Laminated sheet>
A laminated sheet is a sheet produced by laminating and curing a plurality of resin composition layers. The laminated sheet includes a plurality of insulating layers as cured resin composition layers. Generally, the number of resin composition layers laminated to produce a laminated sheet corresponds to the number of insulating layers included in the laminated sheet. The specific number of insulating layers per laminated sheet is usually 2 or more, preferably 3 or more, particularly preferably 5 or more, preferably 20 or less, more preferably 15 or less, and particularly preferably 10 or less. .

A laminated sheet is a sheet that is folded so that its one surfaces face each other. The minimum bending radius for bending the laminated sheet is not particularly limited, but is preferably 0.1 mm or more, more preferably 0.2 mm or more, still more preferably 0.3 mm or more, and preferably 5 mm or less. It is preferably 4 mm or less, particularly preferably 3 mm or less.

A hole may be formed in each insulating layer included in the laminated sheet. This hole can function as a via hole or a through hole in a multilayer flexible substrate.

The laminated sheet may further contain optional elements in addition to the insulating layer. For example, the laminate sheet may have a conductor layer as an optional element. A conductor layer is usually partially formed on the surface of an insulating layer or between insulating layers. This conductor layer usually functions as wiring in a multilayer flexible substrate.

The conductor material used for the conductor layer is not particularly limited. In a preferred embodiment, the conductor layer contains one or more selected from the group consisting of gold, platinum, palladium, silver, copper, aluminum, cobalt, chromium, zinc, nickel, titanium, tungsten, iron, tin and indium. Contains metal. The conductor material may be a single metal or an alloy. Examples of alloys include alloys of two or more metals selected from the above group (eg, nickel-chromium alloys, copper-nickel alloys, and copper-titanium alloys). Among them, chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver or copper as a single metal; nickel-chromium alloy, copper • Alloys such as nickel alloys and copper-titanium alloys; are preferred. Among them, single metals of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver or copper; and nickel-chromium alloys; are more preferred, and single metals of copper are even more preferred.

The conductor layer may have a single layer structure, or may have a multi-layer structure including two or more single metal layers or alloy layers made of different kinds of metals or alloys. When the conductor layer has a multilayer structure, the layer in contact with the insulating layer is preferably a single metal layer of chromium, zinc or titanium, or an alloy layer of nickel-chromium alloy.

The conductor layer may be patterned to function as a wire.

The thickness of the conductor layer depends on the design of the multilayer flexible substrate, but is preferably 3 μm to 35 μm, more preferably 5 μm to 30 μm, even more preferably 10 μm to 20 μm, particularly preferably 15 μm to 20 μm.

The thickness of the laminated sheet is preferably 100 µm or more, more preferably 150 µm or more, particularly preferably 200 µm or more, and preferably 2,000 µm or less, more preferably 1,000 µm or less, and particularly preferably 500 µm or less.

<Method for producing laminated sheet>
The laminated sheet can be produced by a production method including (a) a step of preparing a resin sheet, and (b) a step of laminating and curing a plurality of resin composition layers using the resin sheet. The order of lamination and curing of the resin composition layers is arbitrary as long as a desired laminated sheet can be obtained. For example, after laminating all the plural resin composition layers, the laminated plural resin composition layers may be collectively cured. Further, for example, each time another resin composition layer is laminated on a certain resin composition layer, the laminated resin composition layer may be cured.

A preferred embodiment of step (b) is described below. In the embodiments described below, the resin composition layers are appropriately numbered such as "first resin composition layer" and "second resin composition layer" for distinction. Insulating layers obtained by curing the resin composition layer in (1) are numbered like "first insulating layer" and "second insulating layer" in the same manner as the resin composition layer.

In one preferred embodiment, step (b) comprises
(II) curing the first resin composition layer to form a first insulating layer;
(VI) a step of laminating a second resin composition layer on the first insulating layer;
(VII) curing the second resin composition layer to form a second insulating layer;
including. In addition, step (b), if necessary,
(I) a step of laminating a first resin composition layer on the sheet supporting substrate;
(III) making holes in the first insulating layer;
(IV) a step of roughening the first insulating layer;
(V) A step of forming a conductor layer on the first insulating layer. Each step will be described below.

Step (I) is a step of laminating a first resin composition layer on the sheet supporting substrate prior to step (II). The sheet supporting substrate is a peelable member, and for example, a plate-like, sheet-like or film-like member is used.

Lamination of the sheet supporting substrate and the first resin composition layer may be performed by a vacuum lamination method. In the vacuum lamination method, the thermocompression temperature is preferably in the range of 60° C. to 160° C., more preferably 80° C. to 140° C., and the thermocompression pressure is preferably 0.098 MPa to 1.77 MPa, more preferably 0. .29 MPa to 1.47 MPa, and the heat pressing time is preferably 20 seconds to 400 seconds, more preferably 30 seconds to 300 seconds. Lamination is preferably carried out under reduced pressure conditions of 26.7 hPa or less.

Lamination can be done with a commercially available vacuum laminator. Commercially available vacuum laminators include, for example, a vacuum pressurized laminator manufactured by Meiki Seisakusho, a vacuum applicator manufactured by Nikko Materials, a batch vacuum pressurized laminator, and the like.

When a resin sheet is used, lamination of the sheet supporting base material and the first resin composition layer is performed, for example, by pressing the resin sheet from the support side and attaching the first resin composition layer of the resin sheet to the sheet supporting base material. It can be carried out by thermocompression bonding. As a member for thermocompression bonding of the resin sheet to the sheet supporting base material (hereinafter sometimes referred to as "thermocompression bonding member" as appropriate), for example, a heated metal plate (such as a SUS end plate) or a metal roll (SUS roll) can be used. etc. Instead of pressing the thermocompression member directly onto the resin sheet, it is preferable to press the resin sheet through an elastic material such as heat-resistant rubber so that the first resin composition layer sufficiently follows the surface irregularities of the sheet supporting base material.

After lamination, the first resin composition layer may be subjected to a smoothing treatment under normal pressure (atmospheric pressure), for example, by pressing with a thermocompression member. For example, when a resin sheet is used, the first resin composition layer of the resin sheet can be smoothed by pressing the resin sheet with a thermocompression member from the support side. The pressing conditions for the smoothing treatment may be the same as the thermocompression bonding conditions for the lamination described above. Smoothing treatment can be performed with a commercially available laminator. Lamination and smoothing may be performed continuously using the commercially available vacuum laminator described above.

Step (II) is a step of curing the first resin composition layer to form a first insulating layer. The thermosetting conditions for the first resin composition layer are not particularly limited, and any conditions employed when forming an insulating layer of a printed wiring board can be applied.

Specific thermosetting conditions usually vary depending on the type of resin composition. For example, the curing temperature is preferably 120°C to 240°C, more preferably 150°C to 220°C, even more preferably 170°C to 210°C. The curing time is preferably 5 minutes to 120 minutes, more preferably 10 minutes to 110 minutes, still more preferably 20 minutes to 100 minutes.

Before thermally curing the first resin composition layer, the first resin composition layer may be preheated at a temperature lower than the curing temperature. For example, prior to thermosetting the first resin composition layer, the first resin is The composition layer may be preheated for 5 minutes or more (preferably 5 minutes to 150 minutes, more preferably 15 minutes to 120 minutes, even more preferably 15 minutes to 100 minutes).

Step (III) is a step of drilling holes in the first insulating layer. Through this step (III), holes such as via holes and through holes can be formed in the first insulating layer. Drilling may be performed using, for example, a drill, laser, plasma, etc., depending on the composition of the resin composition. The dimensions and shape of the holes may be appropriately set according to the design of the multilayer flexible substrate.

Step (IV) is a step of roughening the first insulating layer. Smear is usually also removed in this step (IV). Therefore, roughening treatment is sometimes called desmear treatment. Examples of the roughening treatment include a method in which swelling treatment with a swelling liquid, roughening treatment with an oxidizing agent, and neutralization treatment with a neutralizing liquid are performed in this order.

Examples of the swelling liquid include, but are not particularly limited to, alkaline aqueous solutions such as sodium hydroxide aqueous solution and potassium hydroxide aqueous solution. Examples of commercially available swelling liquids include "Swelling Dip Securigans P" and "Swelling Dip Securigans SBU" manufactured by Atotech Japan. The swelling treatment with a swelling liquid can be carried out, for example, by immersing the cured product in a swelling liquid of 30 to 90° C. for 1 to 20 minutes. From the viewpoint of suppressing the swelling of the resin of the insulating layer to an appropriate level, it is preferable to immerse the insulating layer in a swelling liquid at 40° C. to 80° C. for 5 minutes to 15 minutes.

Examples of the oxidizing agent include, but are not limited to, an alkaline permanganate solution in which a permanganate is dissolved in an aqueous sodium hydroxide solution or an aqueous potassium hydroxide solution. The permanganate concentration in the alkaline permanganate solution is preferably 5% by mass to 10% by mass. Examples of commercially available oxidizing agents include alkaline permanganate solutions such as "Concentrate Compact P", "Concentrate Compact CP", and "Dosing Solution Security P" manufactured by Atotech Japan. . The roughening treatment with an oxidizing agent can be performed by immersing the cured product in an oxidizing agent solution heated to 60° C. to 80° C. for 10 to 30 minutes.

Moreover, an acidic aqueous solution is used as the neutralization liquid. Commercially available products include, for example, "Reduction Solution Securigant P" manufactured by Atotech Japan. The treatment with the neutralizing solution can be carried out by immersing the cured product in the neutralizing solution at 30° C. to 80° C. for 5 to 30 minutes. From the viewpoint of workability, etc., it is preferable to immerse the cured product in a neutralizing solution at 40° C. to 70° C. for 5 to 20 minutes.

The arithmetic mean roughness (Ra) of the surface of the first insulating layer after roughening treatment is preferably 400 nm or less, more preferably 300 nm or less, and even more preferably 200 nm or less. Although the lower limit is not particularly limited, it may be 30 nm or more, 40 nm or more, or 50 nm or more.

Step (V) is a step of forming a conductor layer on the first insulating layer, if necessary. Methods for forming the conductor layer include, for example, plating, sputtering, vapor deposition, etc. Among them, plating is preferable. Preferred examples include a method of plating the surface of the first insulating layer by an appropriate method such as a semi-additive method or a full-additive method to form a conductor layer having a desired wiring pattern. Among them, the semi-additive method is preferable from the viewpoint of simplicity of production.

An example of forming a conductor layer by a semi-additive method is shown below. First, a plating seed layer is formed on the surface of the first insulating layer by electroless plating. Next, a mask pattern is formed on the formed plating seed layer to expose a portion of the plating seed layer corresponding to a desired wiring pattern. After forming a metal layer on the exposed plating seed layer by electroplating, the mask pattern is removed. After that, the unnecessary plating seed layer is removed by etching or the like, and a conductor layer having a desired wiring pattern can be formed.

After obtaining the first insulating layer in step (II) and performing steps (III), (IV), and (V) as necessary, step (VI) is performed. Step (VI) is a step of laminating the second resin composition layer on the first insulating layer. The lamination of the first insulating layer and the second resin composition layer can be carried out in the same manner as the lamination of the sheet supporting substrate and the first resin composition layer in step (I).

However, when the resin sheet is used to form the first resin composition layer, the support of the resin sheet is removed prior to step (VI). The removal of the support may be carried out between steps (I) and (II), between steps (II) and (III), or between steps (III) and (IV). ) or between step (IV) and step (V).

After step (VI), step (VII) is performed. Step (VII) is a step of curing the second resin composition layer to form a second insulating layer. Curing of the second resin composition layer can be performed in the same manner as curing of the first resin composition layer in step (II). As a result, a laminated sheet including a plurality of insulating layers, ie, the first insulating layer and the second insulating layer, can be obtained.

Further, in the method according to the above embodiment, if necessary, (VIII) the step of drilling the second insulating layer, (IX) the step of roughening the second insulating layer, and (X) the second insulating layer forming a conductor layer on the layer. The drilling of the second insulating layer in step (VIII) can be done in the same manner as the drilling of the first insulating layer in step (III). Further, the roughening treatment of the second insulating layer in step (IX) can be performed by the same method as the roughening treatment of the first insulating layer in step (IV). Furthermore, the formation of the conductor layer on the second insulating layer in step (X) can be performed in the same manner as the formation of the conductor layer on the first insulating layer in step (V).

In the above embodiment, an embodiment in which a laminated sheet is produced by laminating and curing two resin composition layers, that is, a first resin composition layer and a second resin composition layer, is described. Laminated sheets may be produced by lamination and curing of layers. For example, in the method according to the above embodiment, lamination and curing of the resin composition layer in steps (VI) to step (VII), and, if necessary, drilling of the insulating layer in steps (VIII) to (X) , the roughening treatment of the insulating layer, and the formation of the conductor layer on the insulating layer, may be repeated to produce the laminated sheet. Thereby, a laminated sheet including three or more insulating layers is obtained.

Furthermore, the methods according to the above embodiments may include any steps other than those described above. For example, when step (I) is performed, a step of removing the sheet supporting base material may be performed.

<Multilayer flexible substrate>
Multilayer flexible substrates include laminated sheets. The multilayer flexible substrate may contain only the laminated sheet, or may contain any member in combination with the laminated sheet. Examples of optional members include electronic components and coverlay films.

A multilayer flexible substrate can be manufactured by a manufacturing method including the method of manufacturing a laminated sheet described above. Therefore, the multilayer flexible substrate can be manufactured by a manufacturing method including (a) a step of preparing a resin sheet, and (b) a step of laminating and curing a plurality of resin composition layers using the resin sheet.

The method for manufacturing a multilayer flexible substrate may further include optional steps in combination with the above steps. For example, a method for manufacturing a multilayer flexible substrate having electronic components may include a step of bonding the electronic components to the laminated sheet. Any condition that allows conductor connection between the terminal electrodes of the electronic component and the conductor layer as the wiring provided on the laminated sheet can be adopted as the joining condition of the laminated sheet and the electronic component. Further, for example, the method for manufacturing a multilayer flexible substrate provided with a coverlay film may include a step of laminating the laminate sheet and the coverlay film.

The multilayer flexible substrate can be used by folding such that one side of the laminated sheet included in the multilayer flexible substrate faces each other. For example, a multilayer flexible substrate is folded to be reduced in size and stored in a housing of a semiconductor device. Further, for example, in a semiconductor device having a bendable movable portion, the multilayer flexible substrate is provided in the movable portion.

<Semiconductor device>
A semiconductor device includes the multilayer flexible substrate described above. A semiconductor device includes, for example, a multilayer flexible substrate and a semiconductor chip mounted on the multilayer flexible substrate. In many semiconductor devices, a multilayer flexible substrate can be folded and accommodated in a housing of the semiconductor device such that one surface of a laminated sheet included in the multilayer flexible substrate faces each other.

Semiconductor devices include, for example, various semiconductor devices used in electrical appliances (e.g., computers, mobile phones, digital cameras, televisions, etc.) and vehicles (e.g., motorcycles, automobiles, trains, ships, aircraft, etc.). be done.

The above-described semiconductor device includes, for example, steps of preparing a multilayer flexible substrate, folding the multilayer flexible substrate so that one surface of a laminated sheet faces each other, storing the folded multilayer flexible substrate in a housing, It can be manufactured by a manufacturing method including

EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples. However, the present invention is not limited to the following examples. In the following description, "parts" and "%" representing amounts mean "parts by mass" and "% by mass", respectively, unless otherwise specified. In addition, unless otherwise specified, the operations described below were performed in an environment of normal temperature and normal pressure.

<Synthesis Example 1: Synthesis of polyimide-butadiene resin>
In a reaction vessel, 69 g of bifunctional hydroxy group-terminated polybutadiene ("G-3000" manufactured by Nippon Soda Co., Ltd., number average molecular weight = 3000, hydroxy group equivalent = 1800 g / eq.), and an aromatic hydrocarbon-based mixed solvent (Idemitsu Oil 40 g of "Ipsol 150" manufactured by Kagaku Co., Ltd.) and 0.005 g of dibutyltin laurate were added and mixed to dissolve uniformly. When the mixture became uniform, the temperature was raised to 60° C., and 8 g of isophorone diisocyanate (“IPDI” manufactured by Evonik Degussa Japan, isocyanate group equivalent=113 g/eq.) was added while stirring, and the reaction was carried out for about 3 hours.

Next, 23 g of a cresol novolac resin ("KA-1160" manufactured by DIC, hydroxyl equivalent=117 g/eq.) and 60 g of ethyl diglycol acetate (manufactured by Daicel) were added to the reactant and heated to 150° C. while stirring. The temperature was raised and the reaction was carried out for about 10 hours. The disappearance of the NCO peak at 2250 cm-1 was confirmed by FT-IR. Confirmation of the disappearance of the NCO peak was regarded as the end of the reaction, and the reaction mixture was allowed to cool to room temperature. Then, the reaction product was filtered through a 100-mesh filter cloth to obtain an elastomer having a butadiene structure and phenolic hydroxyl groups (phenolic hydroxyl group-containing butadiene resin: 50% by mass of non-volatile components). The elastomer had a number average molecular weight of 5900 and a glass transition temperature of -7°C.

<Synthesis Example 2: Synthesis of polyimide resin 1>
9.13 g (30 mmol) of 5-amino-1,1'-biphenyl-2-yl 4-aminobenzoate, 4,4'-(4, 15.61 g (30 mmol) of 4'-isopropylidenediphenoxy)bisphthalic dianhydride, 94.64 g (30 mmol) of N-methyl-2-pyrrolidone, 0.47 g (6 mmol) of pyridine and 10 g of toluene were added and placed under a nitrogen atmosphere. , at 180° C. for 4 hours while removing toluene from the system, a polyimide solution containing polyimide resin 1 (non-volatile content: 20 mass %) was obtained. No deposition of synthesized polyimide resin 1 was observed in the polyimide solution.

<Synthesis Example 3: Synthesis of polyimide resin 2>
Aromatic tetracarboxylic dianhydride (“BisDA-1000” manufactured by SABIC Japan, 4,4′-(4,4′ -isopropylidenediphenoxy)bisphthalic dianhydride), 266.5 g of cyclohexanone, and 44.4 g of methylcyclohexane were charged and the solution was heated to 60°C. Then, 43.7 g of dimer diamine (“PRIAMINE 1075” manufactured by Croda Japan) and 5.4 g of 1,3-bis(aminomethyl)cyclohexane were added dropwise, followed by imidization reaction at 140° C. for 1 hour. As a result, a polyimide solution containing polyimide resin 2 (non-volatile content: 30% by mass) was obtained. Moreover, the weight average molecular weight of the polyimide resin 2 was 25,000.

<Synthesis Example 4: Synthesis of polyimide resin 3>
A 500 mL separable flask equipped with a water content receiver connected to a reflux condenser, a nitrogen inlet tube, and a stirrer was prepared. The flask was charged with 20.3 g 4,4′-oxydiphthalic anhydride (ODPA), 200 g γ-butyrolactone, 20 g toluene, and 5-(4-aminophenoxy)-3-[4-(4-aminophenoxy). Phenyl]-1,1,3-trimethylindane (29.6 g) was added, and the mixture was stirred at 45° C. for 2 hours under a nitrogen stream to carry out a reaction. Then, the temperature of this reaction solution was raised, and the condensed water was azeotropically removed together with toluene under a nitrogen stream while maintaining the temperature at about 160°C. It was confirmed that a predetermined amount of water was accumulated in the water content receiver, and that water was no longer seen to flow out. After confirmation, the reaction solution was further heated and stirred at 200° C. for 1 hour. Then, it was cooled to obtain a polyimide solution containing polyimide resin 3 (non-volatile content: 20% by mass). The obtained polyimide resin 3 had a repeating unit represented by the following formula (X1) and a repeating unit represented by the following formula (X2). The weight average molecular weight of the polyimide resin 3 was 12,000.

<Example 1>
Bixylenol type epoxy resin ("YX4000HK" manufactured by Mitsubishi Chemical Corporation, epoxy equivalent of about 185 g / eq.) 5 parts, naphthalene type epoxy resin (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd. "ESN475V", epoxy equivalent of about 332 g / eq.) 5 parts, Bisphenol AF type epoxy resin (manufactured by Mitsubishi Chemical Corporation "YL7760", epoxy equivalent of about 238 g / eq.) 10 parts, cyclohexane type epoxy resin (manufactured by Mitsubishi Chemical Corporation "ZX1658GS", epoxy equivalent of about 135 g / eq.) 2 parts, synthesis 40 parts of the polyimide-butadiene resin obtained in Example 1 (50% by mass of non-volatile components) and 10 parts of cyclohexanone were heated and dissolved in a mixed solvent with stirring. After cooling to room temperature, 4 parts of a triazine skeleton-containing cresol novolac curing agent (DIC's "LA-3018-50P", hydroxyl equivalent of about 151, non-volatile content of 50% 2-methoxypropanol solution), active Ester-based curing agent ("EXB-8000L-65M" manufactured by DIC, active group equivalent of about 220, MEK solution of 65% by mass of non-volatile components) 6 parts, spherical silica ("SC2500SQ" manufactured by Admatechs, average particle size 0.00). 5 μm, specific surface area 11.2 m ² /g, 100 parts of silica surface-treated with 1 part of N-phenyl-3-aminopropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., KBM573)) 40 parts, core 6 parts of shell-type graft copolymer rubber particles ("EXL2655" manufactured by Dow Chemical Japan) and 0.2 parts of an amine-based curing accelerator (4-dimethylaminopyridine (DMAP)) are mixed and mixed uniformly with a high-speed rotating mixer. and filtered through a cartridge filter (“SHP020” manufactured by ROKITECHNO) to prepare a resin composition.

<Example 2>
Instead of using 40 parts of the polyimide-butadiene resin obtained in Synthesis Example 1 (50% by mass of non-volatile components), Example 1 except that 100 parts of the polyimide solution obtained in Synthesis Example 2 (20% by mass of non-volatile components) was used. A resin composition was prepared by performing the same operation.

<Example 3>
Instead of using 40 parts of the polyimide-butadiene resin (50% by mass of non-volatile components) obtained in Synthesis Example 1, the polyimide solution (30% by mass of non-volatile components) obtained in Synthesis Example 3 was used, except that 66.7 parts were used. A resin composition was prepared in the same manner as in Example 1.

<Example 4>
Instead of using 40 parts of the polyimide-butadiene resin obtained in Synthesis Example 1 (50% by mass of non-volatile components), Example 1 except that 100 parts of the polyimide solution obtained in Synthesis Example 4 (20% by mass of non-volatile components) was used. A resin composition was prepared by performing the same operation.

<Example 5>
Instead of using 40 parts of the polyimide-butadiene resin (50% by mass of nonvolatile components) obtained in Synthesis Example 1, a polybutadiene structure-containing resin (manufactured by Nippon Kayaku Co., Ltd., "BX360", block copolymer of polyphenylene ether and polybutadiene, nonvolatile A resin composition was prepared in the same manner as in Example 1, except that 40 parts of a toluene solution containing 50% by mass of the component was used.

<Example 6>
The same operation as in Example 1 except that 20 parts of a bismaleimide resin (manufactured by DM, "BMI689") was used instead of using 40 parts of the polyimide-butadiene resin (50% by mass of non-volatile components) obtained in Synthesis Example 1. was performed to prepare a resin composition.

<Example 7>
Instead of using 40 parts of the polyimide-butadiene resin (50% by mass of non-volatile components) obtained in Synthesis Example 1, polyrotaxane resin ("SH1310P" manufactured by Advanced Soft Materials Co., Ltd., 40% methyl ethyl ketone solution, the axis molecule is a polyethylene glycol chain and the cyclic molecules include cyclodextrins.) A resin composition was prepared in the same manner as in Example 1, except that 50 parts were used.

<Example 8>
The same operation as in Example 1 was performed except that the amount of the core-shell type graft copolymer rubber particles (“EXL2655” manufactured by Dow Chemical Japan Co., Ltd.) used in Example 1 was changed from 6 parts to 12 parts. A resin composition was prepared.

<Comparative Example 1>
The amount of spherical silica used in Example 1 ("SC2500SQ" manufactured by Admatechs, surface-treated) was changed from 40 parts to 70 parts, and the core-shell type graft copolymer rubber particles (Dow Chemical Japan Co., Ltd. A resin composition was prepared in the same manner as in Example 1, except that the amount used was changed from 6 parts to 5 parts.

<Comparative Example 2>
A resin composition was prepared in the same manner as in Example 1, except that 6 parts of the core-shell type graft copolymer rubber particles (manufactured by Dow Chemical Japan Co., Ltd., "EXL2655") of Example 1 were not used. did.

<Comparative Example 3>
Instead of using 40 parts of the polyimide-butadiene resin obtained in Synthesis Example 1 (50% by mass of non-volatile components), phenoxy resin ("YX7553BH30" manufactured by Mitsubishi Chemical Corporation, 30% by mass of solid content) was used, except that 42 parts were used. A resin composition was prepared in the same manner as in Example 1.

<Test Example 1: Evaluation of flexibility (MIT folding endurance)>
The resin composition of each example and comparative example was applied onto the release-treated surface of a PET film (thickness: 38 µm) treated with an alkyd release agent so that the thickness of the resin composition layer after drying was 40 µm. , and dried at 80 to 120° C. (average 100° C.) for 6 minutes to obtain a resin sheet.

The resulting resin sheet was laminated to a polyimide film (Upilex S, manufactured by Ube Industries, Ltd.) using a batch type vacuum pressure laminator ("MVLP-500" manufactured by Meiki Seisakusho Co., Ltd.). Lamination was carried out by reducing the pressure to 13 hPa or less for 30 seconds and then press bonding at 120° C. for 30 seconds at a pressure of 0.74 MPa to obtain a resin sheet with a protective film. Thereafter, the PET film was peeled off from the resin sheet with the protective film, the resin composition was cured under curing conditions of 190° C. for 90 minutes, and the polyimide film was peeled off to obtain a cured product sample.

The obtained cured product sample was cut into a test piece having a width of 15 mm and a length of 110 mm, and an MIT test device (manufactured by Toyo Seiki Seisakusho Co., Ltd., MIT folding endurance fatigue tester "MIT-DA") was used. In accordance with JIS C-5016, the number of folding endurances until breakage of the cured body was measured under the measurement conditions of a load of 2.5 N, a bending angle of 90 degrees, a bending radius of 1.0 mm, and a bending speed of 175 times/min. Five samples were measured, and the average value of the top three points was calculated. When the folding endurance number was less than 8,000 times, it was evaluated as "x", and when it was 8,000 times or more, it was evaluated as "good".

<Test Example 2: Evaluation of Pattern Embedding and Flatness>
<Test Example 2-1: Measurement of minimum melt viscosity>
The minimum melt viscosity of the resin composition layer of the resin sheet obtained in Test Example 1 was measured using a dynamic viscoelasticity measuring device ("Rheosol-G3000" manufactured by UBM). Using a parallel plate with a diameter of 18 mm, 1 g of a sample resin composition sampled from the resin composition layer was heated from a starting temperature of 60° C. to 200° C. at a heating rate of 5° C./min. The dynamic viscoelastic modulus was measured under the measurement conditions of 5° C., frequency of 1 Hz, and strain of 1 deg, and the lowest melt viscosity (poise) was measured.

<Test Example 2-2: Measurement of tack force>
The protective film was peeled off from the resin sheet with the protective film obtained in Test Example 1, and the resin composition layer was subjected to load using a probe tack tester ("TE-6002" manufactured by Tester Sangyo Co., Ltd.) with a glass probe having a diameter of 5 mm. The tack force (N) was measured at 1 kgf/cm ² , a contact speed of 0.5 mm/sec, a tensile speed of 0.5 mm/sec, a holding time of 10 sec, and a temperature of 80°C. When the tack force exceeded 1.6N, it was evaluated as "x", and when it was 1.6N or less, it was evaluated as "good".

<Test Example 2-3: Evaluation of Pattern Embedding and Voids>
As an inner layer circuit board, a glass cloth-based epoxy resin double-sided copper-clad laminate (copper foil thickness 18 μm, substrate thickness 0.15 mm, “HL832NSF LCA” manufactured by Mitsubishi Gas Chemical Co., Ltd., 255*340 mm size) was prepared. Both surfaces of the inner layer circuit board were subjected to a copper surface roughening treatment (copper etching amount: 0.5 μm) using “CZ8201” manufactured by MEC Co., Ltd.

The resin sheet obtained in Test Example 1 was coated with a batch-type vacuum pressure laminator (manufactured by Nikko Materials Co., Ltd., two-stage build-up laminator, CVP700) so that the resin composition layer was in contact with the inner layer circuit board. , laminated on both sides of the inner layer circuit board. Lamination was carried out by pressure bonding for 45 seconds at 130° C. and a pressure of 0.74 MPa after reducing the pressure for 30 seconds to an atmospheric pressure of 13 hPa or less. Then, hot pressing was performed at 120° C. and a pressure of 0.5 MPa for 75 seconds.

The inner layer circuit board laminated with the resin sheet is placed in a 100°C oven under a temperature condition of 100°C for 30 minutes, and then transferred to a 180°C oven under a temperature condition of 180°C for 30 minutes. to form an insulating layer. This is called an "evaluation board".

The support was peeled off from the substrate for evaluation, and the surface of the insulating layer was observed with a micro optical microscope. The pattern embedding property was evaluated as "O" when the pattern was firmly embedded, and as "X" when the embedding was insufficient. Regarding voids, the case where voids did not occur was evaluated as "◯", and the case where voids occurred was evaluated as "x".

Table 1 below shows the amounts of non-volatile components used in the resin compositions of Examples and Comparative Examples, and the measurement results and evaluation results of Test Examples.

(A) a thermosetting resin, (B) an inorganic filler, 5% by mass or more of (C) an organic filler, and (D) a tacky softener by using a resin composition that provides excellent flexibility It was found that the tackiness can be kept low while maintaining the In particular, when the content of the organic filler (C) is 10% by mass or less, void defects are suppressed and pattern embedding properties are excellent.

Claims (16)

A resin composition comprising (A) a thermosetting resin, (B) an inorganic filler, (C) an organic filler, (D) an adhesive softener, and (E) a curing agent,
(B) The content of the component is 30% by mass or more and 60% by mass or less when the nonvolatile component in the resin composition is 100% by mass,
The content of component (C) is 5% by mass or more when the non-volatile component in the resin composition is 100% by mass,
(D) The content of the component is 10% by mass or more when the non-volatile component in the resin composition is 100% by mass,
A resin composition in which the component (E) contains an active ester curing agent. A resin composition comprising (A) a thermosetting resin, (B) an inorganic filler, (C) an organic filler, (D) an adhesive softener, and (E) a curing agent,
The content of the component (B) is 30% by mass or more and 45% by mass or less when the non-volatile component in the resin composition is 100% by mass,
The content of component (C) is 5% by mass or more when the non-volatile component in the resin composition is 100% by mass,
(D) The content of the component is 1% by mass or more when the non-volatile component in the resin composition is 100% by mass,
A resin composition in which the component (E) contains an active ester curing agent. A resin composition comprising (A) a thermosetting resin, (B) an inorganic filler, (C) an organic filler, (D) an adhesive softener, and (E) a curing agent,
(B) The content of the component is 30% by mass or more and 50% by mass or less when the nonvolatile component in the resin composition is 100% by mass,
The content of component (C) is 5% by mass or more when the non-volatile component in the resin composition is 100% by mass,
(D) The content of the component is 5% by mass or more when the non-volatile component in the resin composition is 100% by mass,
A resin composition in which the component (E) contains an active ester curing agent. 4. The resin composition according to any one of claims 1 to 3, wherein the content of component (B) is 35% by mass or more when the non-volatile components in the resin composition are taken as 100% by mass. The resin composition according to any one of claims 1 to 4 , wherein the content of component (C) is 10% by mass or less when the non-volatile components in the resin composition are taken as 100% by mass. The resin composition according to any one of claims 1 to 5 , wherein the component (D) is selected from the group consisting of resins having a polybutadiene structure, polyrotaxane resins, polyimide resins, and maleimide resins having a dimer acid skeleton. . (C) The resin composition according to any one of claims 1 to 6, wherein the organic filler is a core-shell type graft copolymer particle. 8. The resin composition according to claim 7, wherein the monomer component forming the shell portion of the core-shell type graft copolymer particles is a (meth)acrylic acid ester. 9. The resin composition according to claim 7, wherein the core particles of the core-shell type graft copolymer particles contain a thermoplastic elastomer. The resin composition according to any one of claims 1 to 9, wherein component (A) is an epoxy resin. The resin composition according to any one of claims 1 to 10, wherein the resin composition has a solid content of 95% by mass or less. The resin composition according to any one of claims 1 to 11, which is used for forming an insulating layer of a multilayer flexible substrate. A cured product of the resin composition according to any one of claims 1 to 12. A resin sheet comprising a support and a resin composition layer formed of the resin composition according to any one of claims 1 to 12 provided on the support. A multilayer flexible substrate comprising an insulating layer formed by curing the resin composition according to any one of claims 1 to 12. A semiconductor device comprising the multilayer flexible substrate according to claim 15 .