JP7348673B2 - Resin composition, and coverlay film, adhesive sheet, resin-coated metal foil, metal-clad laminate, or printed wiring board using the same - Google Patents

Description

The present invention relates to a resin composition, and a coverlay film, adhesive sheet, resin-coated metal foil, metal-clad laminate, or printed wiring board using the same.

In recent years, flexible printed wiring boards (FPCs) have been frequently used as electronic devices become smaller and more densely packed. Generally, FPC uses a flexible copper clad laminate (FCCL), which is a lamination of an insulating film such as polyimide and copper foil, as a material. It is manufactured by etching copper foil of FCCL to form circuits and wiring, and covering and protecting it with a coverlay film (CL), which is a lamination of a flexible insulating film and an adhesive layer. Further, a multilayer structure may be obtained by laminating a flexible adhesive sheet (BS) and another FCCL on a circuit-formed FCCL.

Adhesives used for CL and BS must be materials that have excellent adhesion to insulating layers and copper foil, heat resistance that can withstand the mounting process, long-term insulation reliability, and workability during manufacturing. There is. In particular, the adhesive flow (resin flow) characteristics during bonding and curing by hot pressing are very important characteristics because they are related to the connection reliability of openings such as terminals and lands/pads.

Various methods have been proposed to satisfy these characteristics. For example, Patent Document 1 proposes controlling the blending amounts of carboxylated ethylene-acrylic rubber and phenolic hydroxyl group-containing aromatic polyamide-carboxylated nitrile butadiene rubber copolymer as elastomers. Patent Document 2 proposes the use of a phosphorus-containing phenoxy resin. Patent Document 3 proposes the use of polyimide siloxane resin. Patent Document 4 proposes the use of imide oligomers. Further, Patent Document 5 proposes laminating two or more layers of adhesives having different resin flow characteristics.

Patent No. 4738859 Japanese Patent Application Publication No. 2011-219590 JP2013-224428A JP 2019-81893 Publication Patent No. 4855291

However, with the methods described in Patent Documents 1 to 5, although it is possible to control the resin flow during hot pressing (primary processing) of CL or BS, it is possible to control the resin flow during hot pressing (secondary processing) such as reinforcing plate processing and shield film processing that follows. No consideration has been given to the resin flow during processing.

If resin flow of CL or BS that has already been laminated occurs during secondary processing, the adhesive that flows out from the edge of the board will be insulated by covering the openings such as terminals and land pads with adhesive. Problems such as removal of the agent and contamination of the process occur.

Therefore, the purpose of this patent is to provide a coverlay, an adhesive sheet, and a circuit board using the same, which have excellent resin flow characteristics during secondary processing.

As a result of intensive studies to solve the above problems, the inventors of the present invention have found that the cured product of the resin composition satisfies specific viscoelastic properties to provide an adhesive layer with excellent resin flow properties during secondary processing. The present inventors have discovered that this is possible, and have completed the present invention.

That is, the present invention is as follows.
[1] A resin composition used for the adhesive layer of a laminated substrate, which is completely cured and formed into a 25 μm thick sheet, is sandwiched between 125 μm thick polyimide films of the same shape from both sides. A laminate is formed, this laminate is punched out to create a disk-shaped specimen, and the specimen is heated from the thickness direction under conditions of 160° C., 2 MPa, and 30 minutes. A resin composition characterized in that the average value of the maximum length of resin flowing outward from the outer periphery (that is, the amount of secondary resin flow) is less than 0.15 mm.
[2] The loss tangent (tan δ) value of a resin composition used in the adhesive layer of a laminated substrate, measured 5 minutes after the start of measurement in dynamic viscoelasticity measurement at 180°C in a completely cured state. A resin composition in which all of T1, T2, and T3 are 0.2 or less, where T1 is the loss tangent value 10 minutes after the start of the measurement, T2 is the loss tangent value 15 minutes after the start of the measurement.
[3] Contains a modified polypropylene resin (A) and an epoxy resin (B),
The resin composition according to [1] or [2], wherein the content of the modified polypropylene resin (A) is 50% by mass or more.
[4] The resin composition according to any one of [1] to [3], which has a dielectric constant of 3.0 or less and a dielectric loss tangent of 0.01 or less at a measurement frequency of 10 GHz in a completely cured state.
[5] The resin composition according to [3], wherein the content of the epoxy resin (B) is 1 part by mass or more and 20% by mass or less.
[6] The resin composition according to [3], wherein the modified polypropylene resin (A) is a resin modified with at least one carboxylic acid compound or its derivative, and has an acid value of 5 mgKOH/g or more. .
[7] One or more curing accelerators selected from tertiary amine curing accelerators, tertiary amine salt curing accelerators, and imidazole curing accelerators are not added, [1] to [6] ] The resin composition according to any one of the above.
[8] The resin composition according to any one of [1] to [7], which is used for adhesion between organic resin base materials, between metal base materials, or between an organic resin base material and a metal base material.
[9] A test specimen was a semi-cured sheet formed into a 25 μm thick sheet and laminated with a 50 μm thick polyimide sheet, with an opening of 1.0 mmφ in the thickness direction. The test specimen was laminated on a 35 μm thick electrolytic copper foil with the polyimide sheet facing outward, and after hot pressing at 180° C. and 2.7 MPa for 60 minutes, the inside of the opening was heated. The resin composition according to any one of [1] to [8], wherein the average value of the maximum length of the resin flowing out is less than 0.2 mm.
[10] An adhesive layer formed using the resin composition according to any one of [1] to [9] above, and a base material in contact with at least one surface of the adhesive layer, A laminate in which the base material is any one of a resin base material, a release resin base material, a paper base material, a release paper base material, and a metal base material.
[11] A coverlay film, adhesive sheet, resin-coated metal foil, or metal-clad laminate comprising the laminate according to [10].
[12] A printed wiring board comprising the laminate according to [10] or the coverlay film, adhesive sheet, resin-coated metal foil, or metal-clad laminate according to [11].
[13] A semiconductor device comprising the printed wiring board according to [12].

According to the present invention, a coverlay film, an adhesive sheet, a metal foil with resin, a metal-clad laminate, or a printed material has excellent resin flow characteristics during heat pressing (secondary processing) such as reinforcing plate processing and shield film processing. A wiring board and a semiconductor device including the above printed wiring board can be provided.

Hereinafter, embodiments of the present invention will be described in detail. However, the present invention is not limited to this.

1. Resin Composition The resin composition according to this embodiment consists of a modified polypropylene resin (A) and an epoxy resin (B). The constituent components of the resin composition will be explained below. In addition, in this embodiment, the resin composition refers to a state in which a slurry in which the above-mentioned components are dissolved or suspended in a solvent such as an organic solvent is applied onto a base material such as release paper and dried (before heating). belongs to.

<Modified polypropylene resin (A)>
The modified polypropylene resin used in the present invention is a polypropylene resin modified with at least one compound containing an organic functional group or a derivative thereof. Specific examples of the organic functional group include a carboxy group, an amino group, a hydroxy group, an epoxy group, a mercapto group, a vinyl group, an acryloyl group, and a methacrylic group. Among these, a carboxy group is preferred. The polypropylene resin is a polymer containing propylene as a monomer, and includes propylene homopolymers, copolymers with other monomers, and hydrides and halides of the resulting polymers. In particular, copolymers with olefinic monomers and hydrogenated products thereof are preferred.

Examples of compounds containing a carboxyl group or a derivative thereof include α,β-unsaturated carboxylic acids such as maleic acid, itaconic acid, citraconic acid, and acid anhydrides thereof. Among these, acid anhydrides are preferred, and maleic anhydride is more preferred. These may be used alone or in combination of two or more. Modification methods include adding a carboxylic acid compound or its derivative as a monomer during polymerization of modified polypropylene resin to form a copolymer, and grafting a carboxylic acid compound or its derivative to unmodified polypropylene resin. Examples include methods to make

The acid value of the modified polypropylene resin is preferably 5 mgKOH/g or more, and 10 mgKOH/g or more and 50 mgKOH/g from the viewpoint of heat resistance, adhesion to organic resin base materials and metal base materials, and resin flow characteristics. It is more preferable that it is below.

The weight average molecular weight (Mw) of the modified polypropylene resin is not particularly limited, but is preferably in the range of 20,000 or more and 180,000 or less. It is preferable that the weight average molecular weight is 20,000 or more because cohesive force becomes strong and adhesiveness is excellent. Furthermore, resin flow characteristics during hot pressing (primary processing) for adhering and curing the adhesive to an adherend can also be improved. Further, it is preferable that the weight average molecular weight is 180,000 or less because it can improve fluidity, improve circuit embedding properties during hot pressing, and improve adhesiveness due to improved wettability. Furthermore, since the solubility in organic solvents is improved, it is possible to suppress deterioration of workability when forming a varnish.

Such modified polypropylene resins are commercially available, and among them, acid-modified polypropylene resins include the "Admer (registered trademark)" series, the "Unistol (registered trademark)" series manufactured by Mitsui Chemicals, and Nippon Paper Industries Co., Ltd. ) "150A", "200S", "200T", "350S", "AE201", "AE301" of the "Auroren (registered trademark)" series manufactured by Dow Chemical Co., Ltd. "Fusabond (registered trademark)" manufactured by Dow Chemical Co., Ltd. series "P353", "P613", "E226", "A560", Sanyo Chemical Co., Ltd.'s "Umex (registered trademark)" series, Mitsubishi Chemical Corporation's "Modic (registered trademark)" series P Type, "M-100", "M-300", "M-310", "PMA H1000A", "PMA H1100A", "PMA H3000A" of the "Toyotac (registered trademark)" series manufactured by Toyobo Co., Ltd. "PMA-T", "PMA-F2", "PMA-L"; "TD-15B", "NS-2002", "NS-2104" of the "Hardren (registered trademark)" series; "MS-003K" , "MS-003JD", "SW-2420", "PL-2051", "PL-2291", "QL-2251", "RL" of the "Highlos-X (registered trademark)" series manufactured by Seiko PMC Co., Ltd. -2027'', ``RL-2047'', ``MG-250P'', ``MG-400P'', ``MG-670P'' of the ``Rikeaid (registered trademark)'' series manufactured by Riken Vitamin Co., Ltd., etc. can be used.

The content of the modified polypropylene resin (A) in the resin composition of the present invention is preferably 50 parts by mass based on 100 parts by mass of solid matter (solid content) remaining when the solvent is completely volatilized from the resin composition. parts by mass or more (since the resin composition according to the present embodiment does not substantially contain a solvent, the content in the resin composition can also be said to be 50% by mass or more). More preferably, the amount is 65 parts by mass or more based on 100 parts by mass of the solid content. By setting the content of the modified polypropylene resin (A) to 50 parts by mass or more based on 100 parts by mass of the solid content, resin flow characteristics during hot pressing (secondary processing) such as reinforcing plate processing and shield film processing are improved. This is preferable because it can improve the properties of the resin and suppress the flow of resin from the openings and the edges of the substrate as small as possible. The upper limit of the content of the modified polypropylene resin (A) with respect to 100 parts by mass of the solid matter of the resin composition is preferably 99 parts by mass or less, and may be 95 parts by mass or less, or 90 parts by mass or less. It may be less than parts by mass.

<Epoxy resin (B)>
Epoxy resin reacts with the carboxyl groups and acid anhydride groups in the modified polypropylene resin (A) to form a three-dimensional crosslinked structure, which provides excellent adhesion to adherends and can withstand the mounting process. Enables high heat resistance and long-term insulation reliability.

The epoxy resin (B) used in the present invention is not particularly limited as long as it has two or more epoxy groups in the molecule. Specifically, biphenyl type epoxy resin, naphthalene type epoxy resin, naphthol type epoxy resin, anthracene type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bisphenol AF type epoxy resin, novolak. Type epoxy resins, trisphenol type epoxy resins, alicyclic epoxy resins, dicyclopentadiene type epoxy resins, aliphatic epoxy resins, glycidylamine type epoxy resins, glycidyl Estes type epoxy resins, heterocyclic epoxy resins, and the like. These may be used alone or in combination of two or more.

Such epoxy resins are commercially available, such as "HP-4032", "HP-4032H", "HP-4032D" (naphthalene type epoxy resin), and "HP-4770" (naphthalene type bifunctional epoxy resin) manufactured by DIC Corporation. epoxy resin), "HP-4700", "HP-4710" (naphthalene type tetrafunctional epoxy resin), "HP-5000", "HP-9900" (naphthalene skeleton modified polyfunctional epoxy resin), "N-690" (cresol novolac type epoxy resin), “N-695” (cresol novolac type epoxy resin), “HP-7200”, “HP-7200L”, “HP-7200H”, “HP-7200HH”, “HP-7200HHH” (dicyclopentadiene type epoxy resin), “EXA-1514” (bisphenol S type epoxy resin), “EXA-7311”, “EXA-7311-G3”, “EXA-7311-G4”, “EXA-7311-G4S” ”, “HP-6000” (naphthylene ether type epoxy resin), Nippon Kayaku Co., Ltd. “EPPN-502H” (trisphenol type epoxy resin), “NC-7000L” (naphthol novolac type epoxy resin), “ "NC-3000H", "NC-3000", "NC-3000L", "NC-3100" (biphenyl type epoxy resin), Nippon Steel & Sumikin Chemical Co., Ltd.'s "ESN4 75V" (naphthalene type epoxy resin), "ESN485" (naphthol novolac type epoxy resin), Mitsubishi Chemical Corporation "YX4000H", "YL6121" (biphenyl type epoxy resin), "YX4000HK" (bixylenol type epoxy resin), "YX8800" (anthracene type epoxy resin), Osaka "PG-100", "CG-500" manufactured by Gas Chemical Co., Ltd., "YL7800" manufactured by Mitsubishi Chemical Corporation (fluorene type epoxy resin), "jER1010" manufactured by Mitsubishi Chemical Corporation (solid bisphenol A type epoxy resin) resin), "jER1031S" (tetraphenylethane type epoxy resin), Daicel Corporation's "Epolead PB-3600", "Epolead PB-4700" (epoxidized polybutadiene), Mitsubishi Chemical Corporation's "jER YX7760" ( Fluorine-containing epoxy resin) etc. can be used.

The epoxy resin (B) is preferably an epoxy resin having a saturated hydrocarbon skeleton from the viewpoint of dielectric properties, and specifically, an alicyclic epoxy resin, a dicyclopentadiene type epoxy resin, or an aliphatic epoxy resin is preferable. It is more preferable to use a non-alicyclic epoxy resin such as epoxidized polyolefin.

The content of the epoxy resin (B) in the resin composition of the present invention is preferably 1 part by mass or more and 20 parts by mass or less based on 100 parts by mass of the solid content. More preferably, the amount is 5 parts by mass or more and 20 parts by mass or less based on 100 parts by mass of the solid content. By setting the content of the epoxy resin (B) within this range, sufficient crosslinking density can be maintained and deterioration in adhesiveness and heat resistance can be suppressed, which is preferable. Further, the influence on dielectric properties can also be suppressed.

Since the resin composition according to the present embodiment is composed of the above-mentioned modified polypropylene resin (A) and epoxy resin (B), each component described below is not an essential component, but it depends on the intended use. It can also be added as appropriate depending on the situation.

<Curing accelerator>
A curing accelerator is a compound that has the effect of catalyzing and promoting the reaction between a modified polypropylene resin and an epoxy resin. Specific examples include tertiary amine curing accelerators, tertiary amine salt curing accelerators, and imidazole curing accelerators. These compounds act as nucleophiles for epoxy groups and generate zwitterionic active species, thereby promoting the curing reaction. Epoxy resin compositions have been used for a long time to control reactivity, and many examples have been reported in which cured physical properties such as adhesiveness and heat resistance are improved.

However, in the reaction between a modified polypropylene resin and an epoxy resin, a sufficient reaction rate can be obtained even without the presence of a curing accelerator. Therefore, the curing accelerator is not an essential component, but may be added if it is necessary to further improve the reaction rate. However, if a predetermined amount or more of the curing accelerator is added, the pot life may be reduced when varnished or slurried, and the resin composition described in this embodiment may be used to produce coverlay films, adhesive sheets, resin-coated metal foils, etc. When a semi-cured (B stage) adhesive layer is formed, the product life may be shortened. Therefore, in the present invention, it is preferable that the content of the curing accelerator is below an amount that causes a decrease in pot life or product life, and it is more preferable that no curing accelerator is added.

<(Poly)carbodiimide resin>
(Poly)carbodiimide resin is a general term for polymers having carbodiimide bonds. In (poly)carbodiimide resin, the carbodiimide group reacts with functional groups such as hydroxy groups, amino groups, and carboxy groups of the base resin, increasing the interaction between the resin composition and the base material, resulting in improved adhesion. It has been known.

Such (poly)carbodiimide resins are commercially available, including the "Carbodilite (registered trademark)" series manufactured by Nisshinbo Chemical Co., Ltd.

(Poly)carbodiimide resins are generally produced by polycondensing diisocyanate compounds or polyfunctional isocyanate compounds in the presence of a catalyst. Due to the convenience of this production method, several percent of unreacted isocyanate groups often remain. Isocyanate groups have very high reactivity and can react with modified polypropylene resins and epoxy resins, which may lead to a decrease in life characteristics, similar to curing accelerators. Therefore, in the present embodiment, the content of the (poly)carbodiimide resin is preferably at most an amount that causes a reduction in product life, and it is more preferable that no (poly)carbodiimide resin is added.
The amount that causes a decrease in product life or less is preferably more than 0 parts by mass and 0.4 parts by mass or less, more preferably 0.3 parts by mass or less, based on 100 parts by mass of the solid content. , 0.2 part by mass or less is particularly preferable.

In addition to the above, the resin composition of the present invention also contains a thermoplastic resin, a tackifier, a flame retardant, a curing agent, a coupling agent, a heat aging inhibitor, a leveling agent, an antifoaming agent, a filler, a pigment, and Organic solvents, etc. are used within a range that does not affect the functions of the resin composition, for example, the total of other components excluding the modified polypropylene resin and epoxy resin is 49 parts by mass or less based on 100 parts by mass of the resin composition, 40 parts by mass 30 parts by weight or less, 20 parts by weight or less, 10 parts by weight or less, 5 parts by weight or less, or 1 part by weight or less.

<Thermoplastic resin>
Examples of thermoplastic resins other than the modified polypropylene resin (A) include phenoxy resins, polyamide resins, polyester resins, polycarbonate resins, polyphenylene oxide resins, polyurethane resins, polyacetal resins, and polyolefin resins. These thermoplastic resins may be unmodified or functionally modified. Further, they may be used alone or in combination of two or more. In particular, polyolefin resins have low dielectric properties and excellent adhesion to substrates, and are therefore suitable for addition to the resin composition of the present invention.

Such polyolefin resins are commercially available, such as "Tuffprene (registered trademark)" series, "Asaprene (registered trademark) T" series manufactured by Asahi Kasei Corporation, and "Krayton (registered trademark) D" manufactured by Kraton Polymer Japan Co., Ltd. "SBS" series (SBS resin), Asahi Kasei Corporation's "Tuftec (registered trademark) H" series, "Tuftec (registered trademark) P" series, Kraton Polymer Japan Co., Ltd.'s "Kraton (registered trademark) A" series, "Krayton (registered trademark) E" series, "Kraton (registered trademark) G" series (SEBS resin), "Tuftec (registered trademark) M" series, manufactured by Asahi Kasei Corporation, "Krayton (registered trademark)" series, manufactured by Kraton Polymer Japan Co., Ltd. FG series (registered trademark) (acid-modified SEBS resin).

<Tackifier>
Examples of the tackifier include coumaron-indene resin, terpene resin, terpene-phenol resin, rosin resin, pt-butylphenol-acetylene resin, phenol-formaldehyde resin, xylene-formaldehyde resin, petroleum hydrocarbon resin, Examples include hydrogenated hydrocarbon resins and turpentine resins. These tackifiers may be used alone or in combination of two or more.

<Flame retardant>
The flame retardant may be either an organic flame retardant or an inorganic flame retardant. Examples of organic flame retardants include melamine phosphate, melamine polyphosphate, guanidine phosphate, guanidine polyphosphate, ammonium phosphate, ammonium polyphosphate, ammonium phosphate, ammonium polyphosphate, carbamate phosphate, and carbamate polyphosphate. , aluminum trisdiethylphosphinate, aluminum trismethylethylphosphinate, aluminum trisdiphenylphosphinate, zinc bisdiethylphosphinate, zinc bismethylethylphosphinate, zinc bisdiphenylphosphinate, titanyl bisdiethylphosphinate, titanium tetrakisdiethylphosphinate Phosphorous flame retardants such as titanyl bismethylethylphosphinate, titanium tetrakismethylethylphosphinate, titanyl bisdiphenylphosphinate, titanium tetrakisdiphenylphosphinate; triazine compounds such as melamine, melam, melamine cyanurate, and cyanuric acid compounds. , nitrogen-based flame retardants such as isocyanuric acid compounds, triazole compounds, tetrazole compounds, diazo compounds, and urea; and silicon-based flame retardants such as silicone compounds and silane compounds. Inorganic flame retardants include metal hydroxides such as aluminum hydroxide, magnesium hydroxide, zirconium hydroxide, barium hydroxide, and calcium hydroxide; tin oxide, aluminum oxide, magnesium oxide, zirconium oxide, zinc oxide, Metal oxides such as molybdenum oxide and nickel oxide; zinc carbonate, magnesium carbonate, barium carbonate, zinc borate, hydrated glass, and the like. Two or more types of these flame retardants can be used in combination.

<Curing agent>
Examples of the curing agent include amine curing agents and acid anhydride curing agents, but are not limited thereto. Examples of the amine curing agent include melamine resins such as methylated melamine resin, butylated melamine resin, and benzoguanamine resin, dicyandiamide, and 4,4'-diphenyldiaminosulfone. Furthermore, examples of the acid anhydride include aromatic acid anhydrides and aliphatic acid anhydrides. These curing agents may be used alone or in combination of two or more.

<Coupling agent>
Examples of the coupling agent include vinyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-acryloxypropyltrimethoxysilane, N-2 -(Aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-ureidopropyltriethoxysilane, 3-mercaptopropylmethyldimethoxysilane, bis(triethoxysilylpropyl)tetrasulfide, 3-isocyanatepropyltriethoxysilane, imidazole Examples include silane coupling agents such as silane; titanate coupling agents; aluminate coupling agents; and zirconium coupling agents. These may be used alone or in combination of two or more.

<Anti-aging agent>
The heat aging inhibitors include 2,6-di-tert-butyl-4-methylphenol, n-octadecyl-3-(3',5'-di-tert-butyl-4'-hydroxyphenyl)propionate, Tetrakis[methylene-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]methane, pentaerythritoltetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] , triethylene glycol-bis[3-(3-t-butyl-5-methyl-4-hydroxyphenyl)propionate and other phenolic antioxidants; dilauryl-3,3'-thiodipropionate, dimyristyl- Examples include sulfur-based antioxidants such as 3,3'-dithiopropionate; phosphorus-based antioxidants such as trisnonylphenyl phosphite and tris(2,4-di-tert-butylphenyl) phosphite. These may be used alone or in combination of two or more.

<Filler>
The fillers include particles made of inorganic compounds such as titanium oxide, aluminum oxide, zinc oxide, carbon black, silica, talc, copper, and silver; fluorine-based polymers (polytetrafluoroethylene, perfluoroalkoxy alkanes, etc.); Examples include particles made of organic compounds such as various elastomers. These may be used alone or in combination of two or more.

<Organic solvent>
The resin composition according to this embodiment can further contain an organic solvent. The organic solvent used in the present invention is not particularly limited as long as it can uniformly dissolve or disperse the modified polypropylene resin (A) and the epoxy resin (B). Specifically, for example, aromatic hydrocarbons such as benzene, toluene, and xylene, aliphatic hydrocarbons such as hexane, heptane, octane, and decane, and alicyclic hydrocarbons such as cyclohexane, cyclohexene, methylcyclohexane, and ethylcyclohexane. Hydrogen, halogenated hydrocarbons such as trichlorethylene, dichloroethylene, chlorobenzene, chloroform, alcoholic solvents such as methanol, ethanol, isopropyl alcohol, butanol, pentanol, hexanol, propanediol, phenol, acetone, methyl isobutyl ketone, Ketone solvents such as methyl ethyl ketone, pentanone, hexanone, cyclohexanone, isophorone, acetophenone, cellosolves such as methyl cellosolve, ethyl cellosolve, ester solvents such as methyl acetate, ethyl acetate, butyl acetate, methyl propionate, butyl formate, Ethylene glycol mono-n-butyl ether, ethylene glycol mono-iso-butyl ether, ethylene glycol mono-tert-butyl ether, diethylene glycol mono-n-butyl ether, diethylene glycol mono-iso-butyl ether, triethylene glycol mono-n-butyl ether, tetraethylene glycol mono-n-butyl ether, etc. Examples include glycol ether solvents. These may be used alone or in combination of two or more. Usually, organic solvents are used from the viewpoint of workability. From the viewpoint of solubility, low polarity solvents such as aromatic hydrocarbons and aliphatic hydrocarbons are particularly preferred.

When forming the resin composition according to the present embodiment, a solution (varnish) in which each of the above-mentioned components is uniformly dissolved or a slurry in which they are dispersed is prepared, and this solution (varnish) or slurry is applied onto the base material. It is preferable to apply it evenly.
Therefore, from the viewpoint of workability, the content of the organic solvent in the solution (varnish) or slurry is preferably 3 parts by mass or more and 80 parts by mass or less, more preferably, based on 100 parts by mass of the solid content. , 10 parts by mass or more and 50 parts by mass or less. If the content of the organic solvent is 80% by mass or less with respect to 100 parts by mass of the solid content, the viscosity of the solution (varnish) or slurry will be appropriate, making it easy to uniformly apply the solution (varnish) or slurry. As described above, since the resin composition according to the present embodiment is obtained by applying and drying the solution (varnish) or slurry, almost all of the organic solvent evaporates during drying. As a result, the resin composition can be substantially free of organic solvents, but the resin composition may contain a small amount of the organic solvent contained in the solution (varnish) or slurry. .

2. Cured Product By thermosetting the resin composition of the present invention, a cured product that becomes, for example, an insulating layer or an adhesive layer of a laminated substrate can be obtained. In this embodiment, the heat curing includes the following two stages.
When the resin composition is heated, first, a covalent bond forming a two-dimensional crosslink (molecular chain extension) between the modified polypropylene and the epoxy resin in the resin composition occurs, and a cured product in a semi-cured (B stage) state is obtained.
By further heating this semi-cured cured product, covalent bonds that form three-dimensional crosslinks (crosslinks between molecular chains) occur between the modified polypropylene and the epoxy resin, and between the epoxy resins, resulting in a crosslinked structure. A cured product in a completely cured state (C stage) is obtained.
These B stage and C stage can be distinguished, for example, by the solubility when immersed in an organic solvent.
The conditions for this thermosetting are not particularly limited, and, for example, conditions that are normally employed when forming an insulating layer of a printed wiring board may be used.

For example, the curing conditions for the resin composition include a curing temperature in the range of 80°C to 240°C, preferably a range of 120°C to 220°C, more preferably a range of 150°C to 200°C, and a curing time of 1 minute. The duration may be 240 minutes, preferably 1 minute to 180 minutes, more preferably 1 minute to 120 minutes.

Further, hot pressing is usually used as a method of forming an insulating layer of a printed wiring board. The press pressure conditions are also not particularly limited, and commonly used conditions may be used; for example, a range of 0.5 MPa or more and 5.0 MPa or less can be adopted.

In the dynamic viscoelasticity measurement of the C-stage cured product obtained by thermosetting the resin composition according to the present embodiment, the loss tangent (tan δ) value 5 minutes after the start of the measurement was measured at T1. When the value of the loss tangent 10 minutes after the start of measurement is T2, and the value of the loss tangent 15 minutes after the start of measurement is T3, all of T1, T2, and T3 have characteristics of 0.2 or less.

The loss tangent (tan δ) in dynamic viscoelasticity measurement is also called a loss coefficient and is expressed as the ratio (G''/G') of the storage modulus (G') and the loss modulus (G''). During measurement, the storage modulus is the component of energy that is stored inside the object out of the energy generated by external force and strain on the object, and is an index of the object's elasticity. Furthermore, the component that diffuses to the outside is the loss modulus, which is an index of the viscosity of the object. That is, as the loss modulus increases, the loss tangent increases, and conversely, as the loss modulus decreases, the loss tangent decreases.

The smaller the loss tangent, the closer the object is to a perfectly elastic body. In other words, it becomes difficult to flow when external force is applied. According to the resin composition according to the present embodiment, the cured product satisfies the specific loss tangent as described above, so that it can be processed into a reinforcing plate or a shield film after hot pressing (primary processing) of CL or BS. Resin flow during hot pressing (secondary processing) can be suppressed to a range of less than 0.15 mm.

Further, the cured product obtained by thermosetting the resin composition according to the embodiment preferably has a dielectric constant of 3.0 or less and a dielectric loss tangent of 0.01 or less at a measurement frequency of 10 GHz. Conventionally, it has been known that as the frequency of a transmission signal of a substrate becomes higher, the influence of signal deterioration (attenuation, delay, etc.) due to dielectric loss increases. That is, according to the present embodiment, when the cured product of the resin composition satisfies the above-described specific dielectric constant and dielectric loss tangent, excellent signal transmission characteristics can be exhibited even in a high frequency substrate.

3. Laminate The laminate according to the present invention comprises an adhesive layer which is a cured product of the resin composition described above, and a base material in contact with at least one surface of the adhesive layer, the base material being an organic film. , an organic film with release treatment, release paper, or metal foil. A laminate having an adhesive layer can be obtained by uniformly dissolving and dispersing (varnishing) the resin composition of the present invention in a solvent according to a standard method, applying it to a base material, and drying it. Usually, it is manufactured in a semi-cured (B stage) state where only a portion is cured. By bonding the obtained laminate with another base material, a laminate having base materials on both sides of the adhesive layer can be obtained. The laminate may be completely cured (C-staged) by heating.

The base material used for the laminate according to the present invention is not particularly limited as long as it can form an adhesive layer by coating and drying the resin composition of the present invention, but resin base materials, mold release resins, etc. Examples include base materials, paper base materials, release paper base materials, metal base materials, and the like.

<Resin base material>
A resin base material can be used for the purpose of improving electrical insulation and mechanical strength. Examples of the resin base material include polyester resin, polyamide resin, polyimide resin, polyamideimide resin, liquid crystal polymer, polyphenylene sulfide, syndiotactic polystyrene, polyolefin resin, and fluorine resin. Preferably it is a film-like resin.

<Release resin base material>
A release resin base material can be used to transfer the adhesive layer to another base material. As the release resin base material, various olefin films alone such as polyethylene, polypropylene, ethylene-α-olefin copolymer, propylene-α-olefin copolymer, etc., and silicone-based, fluorine-based, Examples include those coated with a mold release agent such as an alkyd type.

<Paper base material>
A paper base material can be used for the purpose of improving electrical insulation and mechanical strength. Examples of paper base materials include wood-free paper, kraft paper, roll paper, glassine paper, and the like. Moreover, glass epoxy etc. can be illustrated as a composite material.

<Release paper base material>
A release paper base material can be used to transfer the adhesive layer to another base material. As a release paper base material, a coating layer of a sealing agent such as clay, polyethylene, or polypropylene is provided on both sides of the above-mentioned paper base material, and a coating layer of a sealant such as a silicone-based, fluorine-based, or alkyd-based material is further applied on each coated layer. Examples include those coated with a mold release agent.

<Metal base material>
As the metal base material, any conventionally known conductive material that can be used for circuit boards can be used. Examples of the material include various metals such as SUS, copper, aluminum, iron, steel, zinc, and nickel, alloys thereof, plated products, and metals treated with other metals such as zinc and chromium compounds. Preferably it is metal foil, more preferably copper foil. The thickness of the metal foil is not particularly limited, but is preferably 1 μm or more, more preferably 3 μm or more, and even more preferably 10 μm or more. Moreover, it is preferably 50 μm or less, more preferably 30 μm or less, and still more preferably 20 μm or less. If the thickness is too thin, it may be difficult to obtain sufficient electrical performance of the circuit. On the other hand, if the thickness is too thick, processing efficiency during circuit production may be reduced. Metal foil is usually provided in roll form. The form of the metal foil used in manufacturing the printed wiring board of the present invention is not particularly limited. When using a ribbon-shaped metal foil, its length is not particularly limited. The width is also not particularly limited, but is preferably about 250 mm to 1000 mm.

4. Coverlay film The coverlay film (CL) in the present invention has an adhesive layer in a B-stage state formed from the resin composition described above on a base material with excellent insulating properties, and has a bond between the base material and the adhesive layer. It is a laminate that is difficult to disassemble. The resin base material described above can be used as the base material having excellent insulation properties. Further, in order to protect the adhesive layer, a protective layer can be laminated on the surface of the adhesive layer that is not in contact with the highly insulating base material. As the protective layer, a release base material (the release resin base material or the release paper base material) can be used. When a protective layer is laminated on the adhesive layer, winding can be performed without causing set-off to the base material, resulting in excellent operability.Since the adhesive layer is protected, it has excellent storage stability and is easy to use. be.

The coverlay film obtained according to the present invention functions as an insulating coating material by peeling off the protective layer, bringing the adhesive layer into surface contact with an arbitrary circuit board, and pressing the film with heat.

5. Adhesive sheet The adhesive sheet (bonding sheet, BS) in the present invention has an adhesive layer in a B stage state formed from the above-mentioned resin composition on a release base material, and the adhesive layer is isolated. This is a laminate that allows for To protect the adhesive layer, a release base material can be laminated on both sides of the adhesive layer. The release base material acts as a protective layer for the adhesive layer, making it possible to wind it up without causing set-off to the base material, resulting in excellent operability, and since the adhesive layer is protected, it has excellent storage stability. It is also easy to use.

In the adhesive sheet obtained by the present invention, one release base material is peeled off, the adhesive layer is transferred to an arbitrary base material, the other release base material is peeled off, and the adhesive layer is transferred to an arbitrary base material. By surface adhering and hot pressing, it functions as an interlayer adhesive.

6. Resin-coated metal foil The resin-coated metal foil in the present invention has an adhesive layer in a B-stage state formed from the resin composition described above on the metal base material, and it is difficult to disassemble the base material and the adhesive layer. It is a laminate. Further, in order to protect the adhesive layer, a protective layer can be laminated on the surface not in contact with the metal base material. A release base material can be used as the protective layer. When a protective layer is laminated on the adhesive layer, winding can be performed without causing set-off to the base material, resulting in excellent operability.Since the adhesive layer is protected, it has excellent storage stability and is easy to use. be.

The resin-coated metal foil obtained by the present invention functions as a circuit-forming material by peeling off the protective layer, bringing the adhesive layer into surface contact with any base material or circuit board, and hot pressing.

7. Metal-clad laminate The metal-clad laminate in the present invention is a laminate in which a metal base material and a resin base material are bonded together and integrated via an adhesive layer formed from the resin composition described above. . The adhesive layer is applied to one base material, dried, bonded to the other base material, and then completely cured using an oven or the like. Alternatively, an adhesive layer and a metal base material may be laminated on both sides of the resin base material.

The metal-clad laminate obtained by the present invention functions, for example, as a circuit forming material for printed wiring boards.

8. Printed Wiring Board The printed wiring board in the present invention includes as a component a laminate formed from a metal foil forming a conductor circuit and a resin base material. The printed wiring board is manufactured, for example, by a conventionally known method such as a subtractive method using the metal-clad laminate described above. If necessary, we can use so-called flexible circuit boards (FPC), flat cables, tape automated bonding ( A general term for circuit boards for TAB).

The printed wiring board of the present invention can have any laminated structure that can be adopted as a printed wiring board. For example, a printed wiring board can be made up of four layers: a resin base layer, a metal foil layer, an adhesive layer, and a cover film layer. Further, for example, a printed wiring board can be made up of five layers: a resin base layer, an adhesive layer, a metal foil layer, an adhesive layer, and a cover film layer.

Furthermore, if necessary, it is also possible to have a structure in which two or three or more of the above printed wiring boards are laminated.

The adhesive layer formed using the resin composition of the present invention can be used as a coverlay film, adhesive sheet, resin-coated metal foil, or metal-clad laminate as a material for printed wiring boards, especially printed wiring boards for high-frequency signal transmission. It can be suitably used as a material.

9. Semiconductor Device The semiconductor device of the present invention includes the printed wiring board according to the present invention described above. The semiconductor device of the present invention can be manufactured using the printed wiring board of the present invention.

Examples of semiconductor devices include various semiconductor devices used in electrical products (eg, computers, mobile phones, digital cameras, televisions, etc.), vehicles (eg, motorcycles, automobiles, trains, ships, aircraft, etc.), and the like.

The semiconductor device of the present invention can be manufactured by mounting components (semiconductor chips) on conductive parts of a printed wiring board. A "conducting location" is a "location on a printed wiring board that transmits electrical signals," and the location may be on the surface or embedded. Further, the semiconductor chip is not particularly limited as long as it is an electric circuit element made of a semiconductor.

The mounting method of the semiconductor chip when manufacturing the semiconductor device of the present invention is not particularly limited as long as the semiconductor chip functions effectively, but specifically, wire bonding mounting method, flip chip mounting method, non-bump mounting method, etc. Examples include a mounting method using a build-up layer (BBUL), a mounting method using an anisotropic conductive film (ACF), and a mounting method using a non-conductive film (NCF). Here, "a mounting method using a bumpless buildup layer (BBUL)" refers to a "mounting method in which a semiconductor chip is directly embedded in a recess of a printed wiring board and the semiconductor chip and wiring on the printed wiring board are connected." It is.

EXAMPLES Hereinafter, the present invention will be specifically explained with reference to Examples, but the present invention is not limited to these Examples. In the following description, "parts" and "%" mean "parts by mass" and "% by mass," respectively, unless otherwise specified.

[Physical property evaluation method]
(1) Varnish Spot Life The varnish spot life in the present invention refers to the storage stability at room temperature of a solution (varnish) obtained by adding, stirring and dissolving a solvent after blending each material. After blending the components shown in Table 1 in the mass proportions shown in Table 1, toluene was added to give a solid content of 20%, stirred and dissolved, and the resin compositions of Examples 1 to 9 and Comparative Examples 1 and 2 were prepared. (varnish) was adjusted. Thereafter, this varnish was transferred to an airtight container, and then stored in a constant temperature bath at 30° C. for 3 days, and the degree of gelation was determined before and after storage for 3 days. Judgment was made based on the following evaluation criteria based on the behavior when a medicine spoon was put into the varnish and the varnish was scooped up.
<Wani spot life evaluation criteria>
〇: Fluid △: Fluid, but sticky, and the resin composition adheres to the medicine spoon ×: Solidified, no fluidity

(2) Amount of resin flow during primary processing The resin flow during primary processing in the present invention refers to bonding a coverlay film or adhesive sheet with an adhesive layer in a semi-cured (B stage) state to any adherend. Refers to the resin flow during hot pressing (primary processing). The first release base material was peeled off from a 25 μm thick adhesive sheet, which will be described later, and then attached to a 50 μm thick polyimide film (manufactured by DuPont Toray Co., Ltd., Kapton) at 120° C., 0.3 MPa, 1.0 m/min. Roll lamination was carried out under the following conditions. This laminate was punched out from the polyimide film side using a visual hand punch (manufactured by Nogami Giken Co., Ltd.) to provide three openings each having a diameter of 1.0 mm. The second release base material was peeled off from this laminate with openings, and laid up on the glossy side of a 35 μm thick electrolytic copper foil (manufactured by Furukawa Electric Co., Ltd., GTS-MP), heated at 180°C, 2. A sample for evaluating the amount of resin flow during primary processing was obtained by hot pressing at 7 MPa for 60 minutes to adhere and completely cure. The amount of resin flow during primary processing was determined by measuring the maximum length of the resin flowing inside the opening at four locations on the top, bottom, left and right of each opening, and calculating the average value.
<Evaluation criteria for resin flow amount during primary processing>
〇: Less than 0.15mm △: 0.15mm or more, less than 0.20mm ×: 0.20mm or more

(3) Amount of resin flow during secondary processing The resin flow during secondary processing in the present invention refers to the adhesive layer that has been completely cured after the first heating press processing, and is subjected to secondary heating such as reinforcing plate processing or shield film processing. Refers to resin flow during press processing. The first release base material was peeled off from a 25 μm thick adhesive sheet, which will be described later, and then attached to a 125 μm thick polyimide film (manufactured by DuPont-Toray Co., Ltd., Kapton) at 120° C., 0.3 MPa, 1.0 m/min. Roll lamination was carried out under the following conditions. The second release base material was peeled off from this laminate, and it was laid up on a 125 μm thick polyimide film (manufactured by DuPont-Toray Co., Ltd., Kapton), followed by hot pressing at 180°C, 2.7 MPa, and 60 minutes. , a completely cured laminate was obtained. The fully cured laminate was punched out using a visual hand punch (manufactured by Nogami Giken Co., Ltd.) to obtain eight disc-shaped samples with a diameter of 1.0 mm. Using this disc-shaped sample, we prepared a 1.5 mm thick SUS plate, a 60 μm thick OPP film (Toray Fan, manufactured by Toray Industries, Inc.), and a 38 μm thick silicone release PET film (manufactured by Mitsui Chemicals Tohcello Co., Ltd.). , SP-PET-O3-BU) / 1 1.0 mm φ disk-shaped sample / 38 μm thick silicone release PET film (Mitsui Chemicals Tohcello Co., Ltd., SP-PET-O3-BU) / 60 μm thick Heat pressing was performed assuming secondary processing with the configuration of OPP film (Toray Fan, manufactured by Toray Industries, Inc.)/SUS plate with a thickness of 1.5 mm. The hot pressing conditions were 160° C., 2 MPa, and 30 minutes. The amount of resin flow during secondary processing was determined by measuring the maximum length of the resin flowing out from the outer periphery of the sample for 8 heat-pressed disk-shaped samples assumed to be subjected to secondary processing, and calculating the average value.
<Evaluation criteria for resin flow amount during secondary processing>
〇: Less than 0.10mm △: 0.10mm or more, less than 0.15mm ×: 0.15mm or more

(4) Peel strength (adhesion)
The first release base material was peeled off from a 25 μm thick adhesive sheet, which will be described later, and then attached to a 50 μm thick polyimide film (manufactured by DuPont Toray Co., Ltd., Kapton) at 120° C., 0.3 MPa, 1.0 m/min. Roll lamination was carried out under the following conditions. The second release base material was peeled off from this laminate and laid up on the glossy side of a 35 μm thick electrolytic copper foil (manufactured by Furukawa Electric Co., Ltd., GTS-MP) at 180°C, 2.7 MPa, 60 A sample for evaluation of peel strength was obtained by heating and pressing for 1 minute to adhere and completely cure. The peel strength was measured by performing a 90° peel test at 23° C. and pulling the film at a tensile rate of 50 mm/min. This test shows the adhesive strength at room temperature.
<Evaluation criteria for peel strength>
◎: 0.7 N/mm or more ○: 0.5 N/mm or more, less than 0.7 N/mm △: 0.3 N/mm or more, less than 0.5 N/mm ×: Less than 0.3 N/mm

(5) Soldering heat resistance The first release base material is peeled off from the 25 μm thick adhesive sheet described later, and a 50 μm thick polyimide film (manufactured by DuPont-Toray Co., Ltd., Kapton) or a single-sided flexible copper-clad laminate is used. (manufactured by Nippon Steel Chemical & Materials Co., Ltd., Espanex, copper foil thickness 18 μm, polyimide thickness 25 μm) was roll laminated with the polyimide side under the conditions of 120° C., 0.3 MPa, and 1.0 m/min. The second release base material is peeled off from this laminate, and the shiny side of 35 μm thick electrolytic copper foil (manufactured by Furukawa Electric Co., Ltd., GTS-MP) or a double-sided flexible copper-clad laminate (Nippon Steel Chemical & Material Co., Ltd.) is removed. Copper foil thickness 18 μm, polyimide thickness 25 μm) (manufactured by Espanex Co., Ltd.) was laid up, heated and pressed at 180°C, 2.7 MPa for 60 minutes, and bonded and completely cured to obtain a sample for evaluation of solder heat resistance. . A sample piece of 25 mm x 25 mm was prepared from this evaluation sample, and after being dried at 105° C. for 1 hour, it was floated for 30 seconds in a molten solder bath at each temperature, and the temperature at which no appearance defect such as blistering occurred was measured.
<Evaluation criteria for soldering heat resistance>
〇: 290℃ or more △: 260℃ or more, less than 290℃ ×: Less than 260℃

(6) Dielectric constant (Dk) and dielectric loss tangent (Df)
Using two adhesive sheets with a thickness of 25 μm, which will be described later, the first release base material was peeled off, and the adhesive layers were roll laminated at 120° C., 0.3 MPa, and 1.0 m/min. . This laminate was heated and pressed at 180° C. and 2.7 MPa for 60 minutes to adhere and completely cure, thereby obtaining samples for evaluation of dielectric constant and dielectric loss tangent. The dielectric constant and dielectric loss tangent were measured by peeling off the second release base material and evaluating the cured adhesive sheet alone. Using a vector network analyzer (manufactured by Rohde & Schwarz GmbH & Co. KG, ZVB20) and a cavity resonator jig (manufactured by Keycom Co., Ltd., TMR-10A), the permittivity and dielectric constant at a frequency of 10 GHz were determined by the perturbation method cavity resonator method. The tangent was measured.
<Evaluation criteria for dielectric constant>
〇: 2.5 or less △: More than 2.5, 3.0 or less ×: More than 3.0 <Evaluation criteria for dielectric loss tangent>
〇: 0.005 or less △: More than 0.005, 0.010 or less ×: More than 0.010

(7) Dynamic viscoelasticity measurement at 180°C Using an adhesive sheet with a thickness of 25 μm, which will be described later, the adhesive layers were placed together at 120°C and 0°C so that the thickness of the adhesive layer was 1.2 mm. Roll lamination was carried out under the conditions of .3 MPa and 1.0 m/min. This laminate was heated and pressed at 180° C. and 2.7 MPa for 60 minutes to adhere and completely cure, thereby obtaining a sample for evaluation of dynamic viscoelasticity measurement at 180° C. The measurement of dynamic viscoelasticity at 180°C was performed by peeling off the second release base material and evaluating the cured adhesive sheet alone. Using a rheometer (ARES-G2, manufactured by TA Instruments Japan Co., Ltd.), the sample was preheated at 180°C for 2 minutes, and then heated in torsion mode at 180°C, frequency 1Hz, and strain 20% for a period of time. Dependency was measured for 20 minutes. The value of the loss tangent (tan δ) 5 minutes after the start of measurement is T1, the value of the loss tangent 10 minutes after the start of measurement is T2, and the value of the loss tangent 15 minutes after the start of measurement is T3. The average value was calculated.
<Evaluation criteria for dynamic viscoelasticity measurement at 180°C>
〇: Loss tangent is 0.1 or less △: Loss tangent exceeds 0.1, 0.2 or less ×: Loss tangent exceeds 0.2

[Adjustment of resin composition, creation of adhesive sheet]
After blending the components shown in Table 1 in the mass proportions shown in Table 1, toluene was added to give a solid content of 20%, stirred and dissolved, and the resin compositions of Examples 1 to 9 and Comparative Examples 1 and 2 were prepared. adjusted.
Each resin composition was applied onto a 38 μm thick silicone release PET film (SP-PET-O3-BU, manufactured by Mitsui Chemicals Tohcello Co., Ltd.) and dried at 120°C for 5 minutes to form a 25 μm thick adhesive. A drug layer (B stage state) was created.
A silicone release PET film (manufactured by Mitsui Chemicals Tohcello Co., Ltd., SP-PET-O3-BU) with a thickness of 50 μm was placed on the dry side of the adhesive layer at 100°C, 0.3 MPa, and 1.0 m/min. Roll lamination was performed to create an adhesive sheet.
Here, the first release base material is a laminate base material (50 μm thick silicone release PET film), and the second release base material is a coated base material (38 μm thick silicone release PET film). be.

Each component shown in Table 1 is as follows.

(1) Modified polypropylene resin A: Acid-modified polypropylene resin

(2) Epoxy resin B
・Epoxy resin B1: Epoxidized polybutadiene ・Epoxy resin B2: Naphthalene skeleton modified polyfunctional epoxy resin ・Epoxy resin B3: Dicyclopentadiene type epoxy resin ・Epoxy resin B4: Fluorine-containing epoxy resin

(3) Thermoplastic resin C: acid-modified SEBS resin

(4) Carbodiimide resin D

As can be seen from the comparison of Examples 1 to 9 and Comparative Examples 1 and 2 in Table 1, when the content of modified polypropylene resin is less than 50 parts by mass, the resin flow amount during primary processing, peel strength, and solder heat resistance , dielectric constant, and dielectric loss tangent, but the loss tangent in dynamic viscoelasticity measurement at 180° C. exceeds 0.2, so the resin flow characteristics during secondary processing are not satisfactory. Therefore, from the viewpoint of resin flow characteristics during secondary processing, it is understood that the content of the modified polypropylene resin is preferably 50 parts by mass or more.

Furthermore, as can be seen from Examples 1 and 5 to 7 in Table 1, when the content of epoxy resin exceeds 20 parts by mass, the amount of resin flow during primary processing, the amount of resin flow during secondary processing, peel strength, solder Although sufficient heat resistance and dielectric constant are exhibited, the dielectric loss tangent deteriorates. Therefore, from the viewpoint of dielectric loss tangent, it is found that the content of the epoxy resin is preferably 1 part by mass or more and 20 parts by mass or less based on 100 parts by mass of the solid content.

Furthermore, although any type of epoxy resin can be used, the loss tangent is the smallest when epoxy resin B1 is used. It turns out that it is more preferable to use a formula epoxy resin.

Regarding the amount of carbodiimide resin added, it has been confirmed that a sufficient pot life can be secured with 0.4 parts by mass of varnish by adding carbodiimide resin. The content is preferably 0.4 parts by mass or less.

Regarding the addition of a curing accelerator, it has been confirmed that sufficient physical properties can be achieved without the addition of a curing accelerator, so there is no need to add a curing accelerator. It can be said that it is preferable not to add.

In addition to excellent adhesion, heat resistance, and insulation reliability, the resin composition of the present invention has good resin flow characteristics during hot pressing (secondary processing) such as reinforcing plate processing and shield film processing. Coverlay films, adhesive sheets, resin-coated metal foils, and metal-clad laminates made using the resin composition of the present invention can be used especially for high-frequency signals that require low dielectric properties (low dielectric constant, low dielectric loss tangent). It is useful for manufacturing flexible printed wiring boards for transmission.

Claims (11)

A resin composition used for an adhesive layer of a laminated substrate,
Contains a modified polypropylene resin (A), an epoxy resin (B) and a filler,
The content of the filler is 20 parts by mass or less with respect to 100 parts by mass of the resin composition,
One or more curing accelerators selected from a tertiary amine curing accelerator, a tertiary amine salt curing accelerator, and an imidazole curing accelerator are not added,
A completely cured sheet with a thickness of 25 μm was sandwiched between polyimide films of the same shape and a thickness of 125 μm from both sides to form a laminate, and this laminate was punched out to form a disk-shaped test specimen. The maximum length of the resin flowing outward from the outer periphery of the specimen (i.e., the secondary resin flow A resin composition having an average value of less than 0.15 mm. The resin composition according to claim 1, wherein the content of the modified polypropylene resin (A) is 50% by mass or more. The resin composition according to claim 1 or 2, which has a dielectric constant of 3.0 or less and a dielectric loss tangent of 0.01 or less at a measurement frequency of 10 GHz in a completely cured state. The resin composition according to any one of claims 1 to 3 , wherein the content of the epoxy resin (B) is 1 part by mass or more and 20% by mass or less. The resin according to any one of claims 1 to 4 , wherein the modified polypropylene resin (A) is a resin modified with at least one carboxylic acid compound or its derivative, and has an acid value of 5 mgKOH/g or more. Composition. The resin composition according to any one of claims 1 to 5, which is used for adhesion between organic resin base materials, between metal base materials, or between an organic resin base material and a metal base material. A test specimen was a laminate in which a 25 μm thick sheet in a semi-cured state was laminated with a 50 μm thick polyimide sheet, and an opening of 1.0 mmφ was provided in the thickness direction. The polyimide sheet was laminated on a 35 μm thick electrolytic copper foil with the polyimide sheet facing outward, and was heated and pressed at 180°C and 2.7 MPa for 60 minutes, and then the resin that had flowed inside the opening was heated and pressed. The resin composition according to any one of claims 1 to 6 , wherein the average value of the maximum length is less than 0.2 mm. An adhesive layer formed using the resin composition according to any one of claims 1 to 7 ,
a base material in contact with at least one surface of the adhesive layer,
A laminate in which the base material is any one of a resin base material, a release resin base material, a paper base material, a release paper base material, and a metal base material. A coverlay film, adhesive sheet, resin-coated metal foil, or metal-clad laminate, comprising the laminate according to claim 8 . A printed wiring board comprising the laminate according to claim 8 or the coverlay film, adhesive sheet, resin-coated metal foil, or metal-clad laminate according to claim 9 . A semiconductor device comprising the printed wiring board according to claim 10 .