TWI851739B - Resin sheets, circuit substrates and semiconductor chip packaging - Google Patents

Abstract

The subject of the present invention is a resin sheet in which the appearance defects of the resin composition layer are suppressed even if the thickness of the resin composition layer is thick; a circuit substrate using the resin sheet, and a semiconductor chip package.

The solution is a resin sheet comprising: a support, and a resin composition layer disposed on the support, wherein the thickness of the resin composition layer is 60 μm or more, and when the length of the support when bonded to the resin composition layer is _LA and the length of the support after being peeled off from the resin composition layer is _LB , _LA / _LB satisfies a relationship of not less than 1.005 and not more than 1.2.

Description

Resin sheets, circuit substrates and semiconductor chip packaging

The present invention relates to a resin sheet. Furthermore, the present invention relates to a circuit substrate using a resin sheet, and a semiconductor chip package.

In recent years, the demand for high-performance electronic devices such as smartphones and tablet devices has gradually increased. As a result, the insulating materials that can be used as sealing layers or insulating layers of these electronic devices are also required to be more functional.

Insulating materials are generally used in the form of a resin sheet having a resin composition layer disposed on a support. For example, Patent Document 1 discloses a sealing sheet, which is used to seal components contained in a circuit board and has a resin composition layer disposed on a support.

[Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Publication No. 2018-162418

When the resin composition layer in the resin sheet is used as a sealing layer, the thickness of the resin composition layer may be insufficient to fully seal the internal parts of the electronic device, so the thickness of the resin composition layer may be increased.

However, if the thickness of the resin composition layer is thick, the appearance of the resin composition layer may be poor.

The present invention is an innovative proposal made in view of the above-mentioned topic, and its purpose is to provide a resin sheet that can suppress the appearance defects of the resin component layer even if the thickness of the resin component layer is thick; a circuit substrate using the resin sheet, and a semiconductor chip package.

The inventor of the present invention has carefully examined the problem to solve the above problem and found that the poor appearance of the resin composition is caused by the wrinkles generated by the support being transferred to the resin composition layer. In addition, the inventor of the present invention has found that the length of the support when it is bonded to the resin composition layer and the length of the support after it is peeled off from the resin composition layer will satisfy the specified relationship of the resin sheet. Since the formation of wrinkles on the support can be suppressed, even if the thickness of the resin composition layer is thick, the poor appearance of the resin composition layer will still be suppressed, and the present invention has been successfully completed.

That is, the present invention includes the following contents.

[1] A resin sheet comprising: a first support, and a resin composition layer bonded to the first support, wherein the thickness of the resin composition layer is 60 μm or more, and the ratio of the in-plane direction of one or more supports L _A / _LB satisfies a relationship of 1.005 or more and 1.2 or less, L _A represents the length of the first support in the in-plane direction when bonded to the resin composition layer, and L _B represents the length of the first support in the in-plane direction after being peeled off from the resin composition layer. [2] A resin sheet as described in [1], wherein the resin sheet comprises a first support, a resin composition layer, and a second support in this order. [3] A resin sheet as described in [1] or [2], wherein the minimum melt viscosity of the resin composition layer at 60°C to 200°C is not less than 1000 poise and not more than 20000 poise. [4] A resin sheet as described in any one of [1] to [3], wherein when the minimum melt viscosity of the resin composition layer at 60°C to 200°C is M (poise) and the thickness of the resin composition layer is T (μm), M/T satisfies the relationship of not less than 5 and not more than 200. [5] A circuit board comprising: an insulating layer formed by a cured product of the resin composition layer in the resin sheet as described in any one of [1] to [4]. [6] A semiconductor chip package, comprising: a circuit substrate as described in [5], and a semiconductor chip mounted on the circuit substrate. [7] A semiconductor chip package, comprising: a semiconductor chip, and a hardened resin composition layer in a resin sheet as described in any one of [1] to [4] that seals the semiconductor chip.

According to the present invention, a resin sheet can be provided in which the appearance of the resin composition layer is suppressed even if the thickness of the resin composition layer is thick; a circuit substrate using the resin sheet, and a semiconductor chip package can be provided.

The present invention is described in detail below by showing embodiments and examples. However, the present invention is not limited to the embodiments and examples listed below, and can be implemented with any changes without exceeding the scope of the patent application of the present invention and the scope of its equivalents.

[Resin composition] Before describing the resin sheet of the present invention in detail, the resin composition used to form the resin composition layer will be described.

The resin composition used in forming the resin composition layer may have sufficient insulating properties when hardened. In one embodiment, the resin composition includes (A) a hardening resin. The resin composition may also include (B) an inorganic filler, (C) a hardening accelerator, (D) a thermoplastic resin, (E) an amphiphilic polyether block copolymer, (F) an elastomer, and (G) other additives as necessary. The following is a detailed description of the components included in the resin composition.

<(A) Curable resin> The resin composition contains (A) curable resin as (A) component. As (A) curable resin, any curable resin that can be used when forming an insulating layer of a printed wiring board can be used, and a thermosetting resin is preferred.

Examples of curable resins include epoxy resins, phenol resins, naphthol resins, benzoxazine resins, active ester resins, cyanate resins, carbodiimide resins, amine resins, and acid anhydride resins. Component (A) may be used alone or in combination of two or more in any ratio. In the following, resins that react with epoxy resins to cure the resin composition, such as phenol resins, naphthol resins, benzoxazine resins, active ester resins, cyanate resins, carbodiimide resins, amine resins, and acid anhydride resins, may be collectively referred to as "curing agents". The resin composition preferably contains an epoxy resin and a hardener as components (A).

Examples of the epoxy resin used as the component (A) include biphenylol type epoxy resins, bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, bisphenol AF type epoxy resins, dicyclopentadiene type epoxy resins, trisphenol type epoxy resins, naphthol novolac type epoxy resins, phenol novolac type epoxy resins, tert-butyl-catechol type epoxy resins, naphthalene type epoxy resins, naphthol type epoxy resins, anthracene type epoxy resins. Resin, epoxy resin of epoxy propylamine type, epoxy resin of epoxy propyl ester type, epoxy resin of cresol novolac type, epoxy resin of biphenyl type, linear aliphatic epoxy resin, epoxy resin having butadiene structure, alicyclic epoxy resin, heterocyclic epoxy resin, epoxy resin containing spiro ring, oxalic acid type epoxy resin, oxalic acid dimethanol type epoxy resin, naphthyl ether type epoxy resin, trihydroxymethyl type epoxy resin, tetraphenylethane type epoxy resin, etc. Epoxy resins may be used alone or in combination of two or more.

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

Epoxy resins include epoxy resins that are liquid at 20°C (hereinafter referred to as "liquid epoxy resins") and epoxy resins that are solid at 20°C (hereinafter referred to as "solid epoxy resins"). The resin composition may contain only a liquid epoxy resin, only a solid epoxy resin, or a combination of a liquid epoxy resin and a solid epoxy resin as component (A).

As the liquid epoxy resin, one having two or more epoxy groups in one molecule is preferred.

As the liquid epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AF type epoxy resin, naphthalene type epoxy resin, epoxypropyl ester type epoxy resin, epoxypropyl amine type epoxy resin, phenol novolac type epoxy resin, alicyclic epoxy resin having an ester skeleton, cyclohexane type epoxy resin, cyclohexanedimethanol type epoxy resin, epoxypropyl amine type epoxy resin, and epoxy resin having a butadiene structure are preferred, and bisphenol A type epoxy resin and bisphenol F type epoxy resin are more preferred.

Specific examples of liquid epoxy resins include "HP4032", "HP4032D", and "HP4032SS" (naphthalene-based epoxy resins) manufactured by DIC Corporation; "828US", "jER828EL", "825", and "Epikote" manufactured by Mitsubishi Chemical Corporation; "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" (epoxypropylamine type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "ZX1059" (a mixture of bisphenol A type epoxy resin and bisphenol F type epoxy resin) manufactured by Nippon Steel Chemical & Materials Co., Ltd.; "EX-721" (epoxypropyl ester type epoxy resin) manufactured by Nagase ChemteX; "Ceroxide "2021P" manufactured by Daicell Corporation (epoxy resin with an ester skeleton); "PB-3600" manufactured by Daicell Corporation (epoxy resin with a butadiene structure); "ZX1658" and "ZX1658GS" manufactured by Nippon Steel Chemicals & Materials Co., Ltd. (liquid 1,4-epoxypropyl cyclohexane type epoxy resins), etc. These can be used alone or in combination of two or more.

As the solid epoxy resin, a solid epoxy resin having three or more epoxy groups in one molecule is preferred, and an aromatic solid epoxy resin having three or more epoxy groups in one molecule is more preferred.

As the solid epoxy resin, preferred are bimethylol type epoxy resin, naphthalene type epoxy resin, naphthalene type tetrafunctional epoxy resin, cresol novolac type epoxy resin, dicyclopentadiene type epoxy resin, trisphenol type epoxy resin, naphthol type epoxy resin, biphenyl type epoxy resin, naphthyl ether type epoxy resin, anthracene type epoxy resin, bisphenol A type epoxy resin, bisphenol AF type epoxy resin, and tetraphenylethane type epoxy resin, and more preferred is naphthalene type epoxy resin.

As the solid epoxy resin, naphthalene-type tetrafunctional epoxy resin, cresol novolac-type epoxy resin, dicyclopentadiene-type epoxy resin, trisphenol-type epoxy resin, naphthol-type epoxy resin, biphenyl-type epoxy resin, naphthyl ether-type epoxy resin, anthracene-type epoxy resin, bisphenol A-type epoxy resin, tetraphenylethane-type epoxy resin are preferred, and naphthalene-type tetrafunctional epoxy resin, naphthol-type epoxy resin, and biphenyl-type epoxy resin are more preferred. Specific examples of solid epoxy resins include "HP4032H" (naphthalene-based epoxy resin), "HP-4700", "HP-4710" (naphthalene-based tetrafunctional epoxy resin), "N-690" (cresol novolac-based epoxy resin), "N-695" (cresol novolac-based epoxy resin), "HP-7200", "HP-7200HH", "HP-7200H "(dicyclopentadiene type epoxy resin), "EXA-7311", "EXA-7311-G3", "EXA-7311-G4", "EXA-7311-G4S", "HP6000" (naphthyl ether type epoxy resin); "EPPN-502H" (trisphenol type epoxy resin), "NC7000L" (naphthol phenolic type epoxy resin) manufactured by Nippon Kayaku Co., Ltd., "NC30 00H", "NC3000", "NC3000L", "NC3100" (biphenyl type epoxy resin); "ESN475V" (naphthalene type epoxy resin), "ESN485" (naphthol phenolic type epoxy resin) made by Nippon Steel Chemical & Materials Co., Ltd.; "YX4000H", "YL6121" (biphenyl type epoxy resin), "YX4000HK" (xylenol type epoxy resin) made by Mitsubishi Chemical Corporation. Epoxy resin), "YX8800" (anthracene type epoxy resin); "PG-100" and "CG-500" manufactured by Osaka Gas Chemical Co., Ltd., "YL7760" (bisphenol AF type epoxy resin), "YL7800" (fluorene type epoxy resin), "jER1010" (solid bisphenol A type epoxy resin), "jER1031S" (tetraphenylethane type epoxy resin) manufactured by Mitsubishi Chemical Corporation, etc. These can be used alone or in combination of two or more.

When a liquid epoxy resin and a solid epoxy resin are used in combination as component (A), the mass ratio (liquid epoxy resin: solid epoxy resin) is preferably 1:0.1 to 1:20, more preferably 1:0.3 to 1:15, and particularly preferably 1:0.5 to 1:10. The desired effect of the present invention can be significantly achieved by the mass ratio of the liquid epoxy resin to the solid epoxy resin being within this range. Moreover, when it is usually used in the form of a film, it will also be given appropriate adhesion. Moreover, when it is usually used in the form of a film, sufficient flexibility can be obtained and the operability is improved. Moreover, a hardened material with sufficient breaking strength can usually be obtained.

The epoxy equivalent of the epoxy resin as component (A) is preferably 50 g/eq. to 5000 g/eq., more preferably 50 g/eq. to 3000 g/eq., more preferably 80 g/eq. to 2000 g/eq., and more preferably 110 g/eq. to 1000 g/eq. By being within this range, the crosslinking density of the cured product of the resin composition becomes sufficient, and an insulating layer with a small surface roughness can be provided. The epoxy equivalent is the mass of the epoxy resin containing 1 equivalent of epoxy groups. The epoxy equivalent can be measured in accordance with JIS K7236.

The weight average molecular weight (Mw) of the epoxy resin as component (A) is preferably 100 to 5000, more preferably 250 to 3000, and more preferably 400 to 1500 from the viewpoint of significantly obtaining the desired effect of the present invention. The weight average molecular weight of the epoxy resin is the weight average molecular weight in terms of polystyrene measured by gel permeation chromatography (GPC).

The content of the epoxy resin as the component (A) is preferably 1% by mass or more, more preferably 3% by mass or more, and more preferably 5% by mass or more, from the viewpoint of obtaining an insulating layer exhibiting good mechanical strength and insulation reliability, when the non-volatile components in the resin composition are set to 100% by mass. The upper limit of the content of the epoxy resin is preferably 45% by mass or less, more preferably 40% by mass or less, and particularly preferably 35% by mass or less, from the viewpoint of significantly obtaining the desired effect of the present invention.

As the active ester resin used as component (A), a resin having one or more active ester groups in one molecule can be used. Among them, as the active ester resin, a resin having two or more highly reactive active ester groups in one molecule, such as phenol esters, thiophenol esters, N-hydroxylamine esters, esters of heterocyclic hydroxyl compounds, etc. is preferred. The active ester resin is preferably obtained by a condensation reaction of a carboxylic acid compound and/or a thiocarboxylic acid compound, and a hydroxyl compound and/or a thiol compound. In particular, from the viewpoint of improving heat resistance, an active ester resin obtained from a carboxylic acid compound and a hydroxyl compound is preferred, and an active ester resin obtained from a carboxylic acid compound and a phenol compound and/or a naphthol compound is more preferred.

Examples of the carboxylic acid compound include benzoic acid, acetic acid, succinic acid, maleic acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, and pyromellitic acid.

Examples of the phenolic compound or naphthol compound include hydroquinone, resorcinol, bisphenol A, bisphenol F, bisphenol S, phenolphthalein, 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, phloroglucinol, benzenetriol, dicyclopentadiene-type diphenolic compounds, and phenol novolac. Here, the "dicyclopentadiene-type diphenolic compound" refers to a diphenolic compound obtained by condensing two molecules of phenol onto one molecule of dicyclopentadiene.

Preferred specific examples of active ester resins include active ester resins containing dicyclopentadiene diphenol structures, active ester resins containing naphthalene structures, active ester resins containing acetylated phenol novolacs, and active ester resins containing benzylated phenol novolacs. Among them, active ester resins containing naphthalene structures and active ester resins containing dicyclopentadiene diphenol structures are preferred. "Dicyclopentadiene diphenol structures" refer to divalent structural units containing phenylene-dicyclopentene-phenylene.

Examples of commercially available active ester resins include "EXB9451", "EXB9460", "EXB9460S", "HPC-8000-65T", "HPC-8000H-65TM", and "EXB-8000L-65TM" (manufactured by DIC Corporation) as active ester resins containing a dicyclopentadiene-type diphenol structure; examples of commercially available active ester resins containing a naphthalene structure include "EXB-8100L-65T", "EXB-8150L-65T", "EXB9416-70BK", "EXB-8150-65T", "HPC-8150-60T", and "HPC-8150-62 T", "EXB-8150-65T" (manufactured by DIC Corporation); as active ester resins containing acetylated products of phenol novolac, "DC808" (manufactured by Mitsubishi Chemical Corporation) can be cited; as active ester resins containing benzylated products of phenol novolac, "YLH1026" (manufactured by Mitsubishi Chemical Corporation) can be cited; as active ester resins of acetylated products of phenol novolac, "DC808" (manufactured by Mitsubishi Chemical Corporation); as active ester resins of benzylated products of phenol novolac, "YLH1026" (manufactured by Mitsubishi Chemical Corporation), "YLH1030" (manufactured by Mitsubishi Chemical Corporation), "YLH1048" (manufactured by Mitsubishi Chemical Corporation) and the like can be cited.

As the phenolic resin and naphthol resin as component (A), those having a phenolic structure are preferred from the viewpoint of heat resistance and water resistance. Furthermore, from the viewpoint of adhesion to the conductive layer, nitrogen-containing phenolic curing agents are preferred, and phenolic resins containing a triazine skeleton are more preferred.

Specific examples of the phenolic resin and the naphthol resin include "MEH-7700", "MEH-7810", and "MEH-7851" manufactured by Meiwa Chemicals, "NHN", "CBN", and "GPH" manufactured by Nippon Kayaku, "SN170", "SN180", "SN190", "SN475", "SN485", "SN495", "SN-495V", "SN375", and "SN395" manufactured by Nippon Steel Chemicals & Materials, and "TD-2090", "LA-7052", "LA-7054", "LA-1356", "LA-3018-50P", and "EXB-9500" manufactured by DIC Corporation.

Specific examples of the benzoxazine resin used as the component (A) include "JBZ-OD100" (benzoxazine ring equivalent: 218), "JBZ-OP100D" (benzoxazine ring equivalent: 218), and "ODA-BOZ" (benzoxazine ring equivalent: 218) manufactured by JFE Chemicals; "P-d" (benzoxazine ring equivalent: 217) and "F-a" (benzoxazine ring equivalent: 217) manufactured by Shikoku Chemical Industries; and "HFB2006M" (benzoxazine ring equivalent: 432) manufactured by Showa High Molecular Co., Ltd.

Examples of the cyanate resin used as the component (A) include bisphenol A dicyanate, polyphenol cyanate, oligo(3-methylene-1,5-phenylene cyanate), 4,4'-methylenebis(2,6-dimethylphenyl cyanate), 4,4'-ethylenediphenyl dicyanate, hexafluorobisphenol A dicyanate, 2,2-bis(4-cyanate)phenylpropane, 1,1-bis(4-cyanate)phenylpropane, Bifunctional cyanate resins such as bis(4-cyanatephenylmethane), bis(4-cyanate-3,5-dimethylphenyl)methane, 1,3-bis(4-cyanatephenyl-1-(methylethylidene))benzene, bis(4-cyanatephenyl)sulfide, and bis(4-cyanatephenyl)ether; polyfunctional cyanate resins derived from phenol novolac and cresol novolac; prepolymers of these cyanate resins partially triazine-modified, etc. Specific examples of cyanate resins include "PT30", "PT30S" and "PT60" (phenol novolac type multifunctional cyanate resins), "ULL-950S" (multifunctional cyanate resin), "BA230", "BA230S75" (prepolymers in which part or all of bisphenol A dicyanate is triazine-treated and becomes a trimer) manufactured by Lonza Japan.

Specific examples of the carbodiimide resin used as the component (A) include Carbodilite (registered trademark) V-03 (carbodiimide group equivalent: 216, V-05 (carbodiimide group equivalent: 216), V-07 (carbodiimide group equivalent: 200), V-09 (carbodiimide group equivalent: 200) manufactured by Nisshinbo Chemical Co., Ltd.; and Stabaxol (registered trademark) P (carbodiimide group equivalent: 302) manufactured by Rhein-Chemie.

As the amine resin used as the component (A), there can be mentioned resins having one or more amino groups in one molecule, such as aliphatic amines, polyether amines, alicyclic amines, aromatic amines, etc. Among them, aromatic amines are preferred from the viewpoint of achieving the desired effect of the present invention. The amine resin is preferably a primary amine or a secondary amine, and a primary amine is more preferred. Specific examples of amine-based curing agents include 4,4'-methylenebis(2,6-dimethylaniline), diphenyldiaminosulfonate, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfonate, 3,3'-diaminodiphenylsulfonate, m-phenylenediamine, m-styrene diamine, diethyltoluenediamine, 4,4'-diaminodiphenyl ether, 3,3'-dimethyl-4,4'-diaminobiphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dihydroxybenzidine, 2,2-bis(3- bis(4-aminophenoxy)phenyl)sulfone, bis(4-(4-aminophenoxy)phenyl)sulfone, and the like. Amine resins that can be used are commercially available products, for example, "KAYABOND C-200S", "KAYABOND C-100", "KAYAHARD A-A", "KAYAHARD A-B", "KAYAHARD A-S" manufactured by Nippon Kayaku Co., Ltd., and "EPICURE W" manufactured by Mitsubishi Chemical Corporation.

Examples of the acid anhydride resin used as the component (A) include resins having one or more acid anhydride groups in one molecule. Specific examples of the acid anhydride resin include anhydrous phthalic acid, anhydrous tetrahydrophthalic acid, anhydrous hexahydrophthalic acid, anhydrous methyltetrahydrophthalic acid, anhydrous methylhexahydrophthalic acid, nadic methyl anhydride, hydrogenated nadic methyl anhydride, anhydrous trialkyltetrahydrophthalic acid, anhydrous dodecenylsuccinic acid, 5-(2,5-dioxotetrahydro-3-furanyl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, anhydrous trimellitic acid, anhydrous pyromellitic acid, benzophenonetetrahydrophthalic acid, and anhydrous succinic acid. Carboxylic acid dianhydride, biphenyltetracarboxylic acid dianhydride, naphthalenetetracarboxylic acid dianhydride, oxyphthalic acid dianhydride, 3,3'-4,4'-diphenylsulfonatetetracarboxylic acid dianhydride, 1,3,3a,4,5,9b-hexahydro-5-(tetrahydro-2,5-dioxy-3-furanyl)-naphtho[1,2-c]furan-1,3-dione, ethylene glycol bis(anhydrous trimellitate), styrene-maleic acid resin obtained by copolymerization of styrene and maleic acid, etc.

When epoxy resin and hardener are contained as component (A), the amount ratio of epoxy resin to all hardeners is preferably in the range of 1:0.01 to 1:5, more preferably 1:0.3 to 1:3, and even more preferably 1:0.5 to 1:2, in terms of [total number of epoxy groups of epoxy resin]:[total number of reactive groups of hardener]. Here, "number of epoxy groups of epoxy resin" refers to the total value obtained by dividing the mass of non-volatile components of epoxy resin in the resin composition by the epoxy equivalent. In addition, the "active base number of the hardener" is the total value obtained by dividing the mass of the non-volatile components of the hardener in the resin composition by the active base equivalent. By making the ratio of the epoxy resin to the hardener as the (B) component within this range, an insulating layer with excellent flexibility can be obtained.

The content of the hardener as component (A) is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, more preferably 1% by mass or more, and preferably 40% by mass or less, more preferably 35% by mass or less, and more preferably 30% by mass or less, relative to 100% by mass of the non-volatile components in the resin composition, from the viewpoint of obtaining an insulating layer with excellent flexibility.

<(B) Inorganic filler> The resin composition may contain an inorganic filler as a component (B) as an optional component. As the material of the inorganic filler (B), an inorganic compound can be used. Examples of inorganic fillers include silicon dioxide, aluminum oxide, glass, cordierite, silica oxide, barium sulfate, barium carbonate, talc, clay, mica powder, zinc oxide, hydrotalcite, alumina, 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, barium zirconate, calcium zirconate, zirconium phosphate, and zirconium tungstate phosphate. Among them, silicon dioxide is particularly suitable. Examples of silica include amorphous silica, fused silica, crystalline silica, synthetic silica, and hollow silica. Spherical silica is preferred as silica. (B) The inorganic filler may be used alone or in combination of two or more.

Examples of commercially available inorganic fillers (B) include "SP60-05" and "SP507-05" manufactured by Nippon Steel & Sumitomo Metal Materials Co., Ltd.; "YC100C", "YA050C", "YA050C-MJE", and "YA010C" manufactured by Admatex; "UFP-30" manufactured by Denka Corporation; "Sylfil NSS-3N", "Sylfil NSS-4N", and "Sylfil NSS-5N" manufactured by Tokuyama Corporation; and "SC2500SQ", "SO-C4", "SO-C2", and "SO-C1" manufactured by Admatex.

(B) The average particle size of the inorganic filler is preferably 0.01 μm or more, more preferably 0.05 μm or more, particularly preferably 0.1 μm or more, preferably 5 μm or less, more preferably 2 μm or less, and even more preferably 1 μm or less, from the viewpoint of significantly obtaining the desired effect of the present invention.

(B) The average particle size of the inorganic filler can be measured by the laser diffraction scattering method based on the Mie scattering theory. Specifically, the particle size distribution of the inorganic filler can be made based on the volume standard using a laser diffraction scattering particle size distribution measuring device, and the average particle size can be measured. The measurement sample can be 100 mg of the inorganic filler and 10 g of methyl ethyl ketone weighed in a vial, and dispersed by applying ultrasound for 10 minutes. The sample to be measured is measured using a laser diffraction particle size distribution measuring device, and the wavelength of the light source is made into blue and red. The particle size distribution of (B) the inorganic filler based on the volume is measured by the flow cell method, and the average particle size is calculated from the obtained particle size distribution as the median diameter. As a laser diffraction particle size distribution measuring device, for example, "LA-960" manufactured by Horiba, Ltd. can be cited.

(B) The specific surface area of the inorganic filler is preferably 1 m ² /g or more, more preferably 2 m ² /g or more, and particularly preferably 3 m ² /g or more, from the viewpoint of significantly obtaining the desired effect of the present invention. The upper limit is not particularly limited, but preferably 60 m ² /g or less, 50 m ² /g or less, or 40 m ² /g or less. The specific surface area can be obtained by using a specific surface area measuring device (Macsorb HM-1210 manufactured by Mountech) according to the BET method, adsorbing nitrogen on the surface of the sample, and calculating the surface area using the BET multipoint method.

(B) Inorganic fillers are preferably treated with a surface treatment agent from the viewpoint of improving moisture resistance and dispersibility. Examples of the surface treatment agent include fluorine-containing silane coupling agents, aminosilane-based coupling agents, epoxysilane-based coupling agents, butylsilane-based coupling agents, silane-based coupling agents, alkoxysilanes, organic silazane compounds, and titanium salt-based coupling agents. The surface treatment agent may be used alone or in combination of two or more.

Examples of commercially available surface treatment agents include "KBM403" (3-glycidoxypropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Industries, Ltd., "KBM803" (3-butylpropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Industries, Ltd., "KBE903" (3-aminopropyltriethoxysilane) manufactured by Shin-Etsu Chemical Industries, Ltd., and "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), etc.

The degree of surface treatment using the surface treatment agent is preferably within a specified range from the perspective of improving the dispersibility of the inorganic filler. Specifically, 100 parts by weight of the inorganic filler is preferably surface treated with 0.2 to 5 parts by weight of the surface treatment agent, preferably 0.2 to 3 parts by weight, and preferably 0.3 to 2 parts by weight.

The degree of surface treatment using a surface treatment agent can be evaluated by the amount of carbon per unit surface area of the inorganic filler. From the perspective of improving the dispersibility of the inorganic filler, the amount of carbon per unit surface area of the inorganic filler is preferably 0.02 mg/ ^m2 or more, preferably 0.1 mg/ ^m2 or more, and more preferably 0.2 mg/ ^m2 or more. On the other hand, from the perspective of suppressing the increase in the melt viscosity of the resin varnish and the melt viscosity in the resin sheet layer, it is preferably 1 mg/ ^m2 or less, preferably 0.8 mg/ ^m2 or less, and more preferably 0.5 mg/ ^m2 or less.

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

(B) From the viewpoint of obtaining an insulating layer with a low dielectric tangent, the content of the inorganic filler is preferably 10 mass % or more, more preferably 15 mass % or more, and more preferably 20 mass % or more, and is preferably 90 mass % or less, more preferably 88 mass % or less, and more preferably 85 mass % or less, when the non-volatile components in the resin composition are taken as 100 mass %.

<(C) Hardening accelerator> The resin composition may contain (C) a hardening accelerator as an optional component. Examples of the hardening accelerator include phosphorus-based hardening accelerators, amine-based hardening accelerators, imidazole-based hardening accelerators, guanidine-based hardening accelerators, and metal-based hardening accelerators. Amine-based hardening accelerators and imidazole-based hardening accelerators are preferred, and imidazole-based hardening accelerators are more preferred. The hardening accelerator may be used alone or in combination of two or more.

Examples of the phosphorus-based hardening accelerator include triphenylphosphine, phosphonium borate compounds, tetraphenylphosphonium tetraphenylborate, n-butylphosphonium tetraphenylborate, tetrabutylphosphonium decanoate, (4-methylphenyl)triphenylphosphonium thiocyanate, tetraphenylphosphonium thiocyanate, and butyltriphenylphosphonium thiocyanate, with triphenylphosphine and tetrabutylphosphonium decanoate being preferred.

As the amine-based hardening accelerator, for example, trialkylamines such as triethylamine and tributylamine, 4-dimethylaminopyridine, benzyldimethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, 1,8-diazabicyclo(5,4,0)-undecene, etc. can be cited, with 4-dimethylaminopyridine and 1,8-diazabicyclo(5,4,0)-undecene being preferred.

Examples of the imidazole-based hardening accelerator 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-undecylimidazole trimellitate, 1-cyanoethyl-2-phenylimidazole trimellitate, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino 2,4-Diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-Diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isocyanuric acid adduct, 2-phenylimidazolyl isocyanuric acid adduct, 2-phenyl-4,5-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl-s-triazine Imidazole compounds such as hydroxymethylimidazole, 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 adducts of imidazole compounds with epoxy resins, preferably 2-ethyl-4-methylimidazole and 1-benzyl-2-phenylimidazole.

As the imidazole-based hardening accelerator, a commercially available product may be used, and for example, "P200-H50" manufactured by Mitsubishi Chemical Corporation may be mentioned.

As the guanidine-based hardening accelerator, 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-methylbiguanidine, 1-ethylbiguanidine, 1-n-butylbiguanidine, 1-n-octadecylbiguanidine, 1,1-dimethylbiguanidine, 1,1-diethylbiguanidine, 1-cyclohexylbiguanidine, 1-allylbiguanidine, 1-phenylbiguanidine, 1-(o-tolyl)biguanidine, etc., preferably dicyandiamide and 1,5,7-triazabicyclo[4.4.0]dec-5-ene.

Examples of the metal hardening accelerator include organic metal complexes or organic metal salts of metals such as cobalt, copper, zinc, iron, nickel, manganese, and tin. Specific examples of the organometallic complex include organic cobalt complexes such as cobalt (II) acetylacetonate and cobalt (III) acetylacetonate, organic copper complexes such as copper (II) acetylacetonate, organic zinc complexes such as zinc (II) acetylacetonate, organic iron complexes such as iron (III) acetylacetonate, organic nickel complexes such as nickel (II) acetylacetonate, and organic manganese complexes such as manganese (II) acetylacetonate. Examples of the organic metal salt include zinc octylate, tin octylate, zinc cycloalkanoate, cobalt cycloalkanoate, tin stearate, zinc stearate and the like.

(C) The content of the hardening accelerator is preferably 0.01 mass % or more, more preferably 0.02 mass % or more, particularly preferably 0.03 mass % or more, and preferably 3 mass % or less, preferably 1 mass % or less, particularly preferably 0.5 mass % or less, when the non-volatile components in the resin composition are taken as 100 mass %.

<(D) Thermoplastic resin> The resin composition may also contain (D) thermoplastic resin as an optional component. Examples of (D) thermoplastic resin include phenoxy resin, polyvinyl acetal resin, polyolefin resin, polyimide resin, polyamide imide resin, polyether imide resin, polysulfone resin, polyethersulfone resin, polyphenylene ether resin, polyetheretherketone resin, polyester resin, etc. Phenoxy resin is preferred. Thermoplastic resins may be used alone or in combination of two or more.

(D) The weight average molecular weight of the thermoplastic resin in terms of polystyrene is preferably 38,000 or more, more preferably 40,000 or more, and more preferably 42,000 or more. The upper limit is preferably 100,000 or less, more preferably 70,000 or less, and more preferably 60,000 or less. (D) The weight average molecular weight of the thermoplastic resin in terms of polystyrene is measured by gel permeation chromatography (GPC). Specifically, the weight average molecular weight of the thermoplastic resin (D) in terms of polystyrene can be measured using LC-9A/RID-6A manufactured by Shimadzu Corporation as a measuring device, Shodex K-800P/K-804L/K-804L manufactured by Showa Denko K.K. as a column, and chloroform or the like as a mobile phase at a column temperature of 40°C, and calculated using a calibration curve of standard polystyrene.

As the phenoxy resin, for example, there can be cited a phenoxy resin having one or more skeletons selected from the group consisting of a bisphenol A skeleton, a bisphenol F skeleton, a bisphenol S skeleton, a bisphenol acetophenone skeleton, a phenolic skeleton, a biphenyl skeleton, a fluorene skeleton, a dicyclopentadiene skeleton, a norbornene skeleton, a naphthalene skeleton, an anthracene skeleton, an adamantane skeleton, a terpene skeleton, and a trimethylcyclohexane skeleton. The terminal of the phenoxy resin may be any functional group such as a phenolic hydroxyl group or an epoxy group. The phenoxy resin may be used alone or in combination of two or more. As specific examples of phenoxy resins, there are "1256" and "4250" (both phenoxy resins containing bisphenol A skeletons), "YX8100" (phenoxy resin containing bisphenol S skeletons), and "YX6954" (phenoxy resin containing bisphenol acetophenone skeletons) manufactured by Mitsubishi Chemical Corporation. Other examples include "YX6954" (phenoxy resin containing bisphenol acetophenone skeletons) manufactured by Nippon Steel Chemical & Materials Corporation. "FX280" and "FX293", "YL7500BH30", "YX6954BH30", "YX7553", "YX7553BH30", "YL7769BH30", "YL6794", "YL7213", "YL7290" and "YL7482" manufactured by Mitsubishi Chemical Corporation, etc.

Examples of the polyvinyl acetal resin include polyvinyl formaldehyde resin and polyvinyl butyral resin, and polyvinyl butyral resin is preferred. Specific examples of the polyvinyl acetal resin include "Denichi Butyral 4000-2", "Denichi Butyral 5000-A", "Denichi Butyral 6000-C", and "Denichi Butyral 6000-EP" manufactured by Denki Kagaku Kogyo Co., Ltd., and S-REC BH series, BX series (e.g., BX-5Z), KS series (e.g., KS-1), BL series, and BM series manufactured by Sekisui Chemical Kogyo Co., Ltd.

Specific examples of polyimide resins include "Rikacote SN20" and "Rikacote PN20" manufactured by Shin Nippon Rika Co., Ltd.

Specific examples of polyamide imide resins include "Vylomax HR11NN" and "Vylomax HR16NN" manufactured by Toyobo Co., Ltd. Specific examples of polyamide imide resins include modified polyamide imides such as "KS9100" and "KS9300" (polyamide imide containing a polysiloxane skeleton) manufactured by Hitachi Chemical Co., Ltd.

Specific examples of polyether sulphide resins include "PES5003P" manufactured by Sumitomo Chemical Co., Ltd. Specific examples of polyphenylene ether resins include "OPE-2St 1200" manufactured by Mitsubishi Gas Chemical Co., Ltd. Specific examples of polyetheretherketone resins include "Sumiploy K" manufactured by Sumitomo Chemical Co., Ltd. Specific examples of polyetherimide resins include "Ultem" manufactured by GE.

As specific examples of the polysulfone resin, there are polysulfones "P1700" and "P3500" manufactured by Solvay Advanced Polymers.

Examples of the polyolefin resin include ethylene copolymer resins such as low-density polyethylene, ultra-low-density polyethylene, high-density polyethylene, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, and ethylene-methyl acrylate copolymer; and polyolefin elastomers such as polypropylene and ethylene-propylene block copolymer.

Examples of the polyester resin include polyethylene terephthalate resin, polyethylene naphthalate resin, polybutylene terephthalate resin, polybutylene naphthalate resin, polytrimethylene terephthalate resin, polytrimethylene naphthalate resin, and polycyclohexane dimethyl terephthalate resin.

Among them, as the (D) thermoplastic resin, phenoxy resin and polyvinyl acetal resin are preferred. Therefore, in one embodiment, the thermoplastic resin preferably includes one or more selected from the group consisting of phenoxy resin and polyvinyl acetal resin. Among them, as the thermoplastic resin, phenoxy resin is preferred, and phenoxy resin with a weight average molecular weight of 40,000 or more is particularly preferred.

(D) The content of the thermoplastic resin is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, and more preferably 0.5% by mass or more, when the non-volatile components in the resin composition are taken as 100% by mass. The upper limit is preferably 5% by mass or less, preferably 4% by mass or less, and more preferably 3% by mass or less.

<(E) Amphiphilic polyether block copolymer> The resin composition may also contain (E) an amphiphilic polyether block copolymer. In the specification of this case, an amphiphilic polyether block copolymer refers to a block copolymer comprising at least one epoxy resin miscible polyether block segment and at least one epoxy resin non-miscible polyether block segment. By making the resin composition contain component (E), the toughness of the resin composition can be improved, and the stress relaxation performance can be improved, thereby reducing the warp of the cured product of the resin composition.

As the epoxy resin miscible polyether block segment, for example, an epoxy resin miscible polyether block segment derived from alkylene oxide can be cited. As the epoxy resin miscible polyether block segment derived from alkylene oxide, for example, a polyalkylene oxide block comprising at least one selected from a polyethylene oxide block, a polypropylene oxide block, a poly(ethylene oxide-co-propylene oxide) block, a poly(ethylene oxide-ran-propylene oxide) block, and a mixture thereof is preferred, and a polyethylene oxide block is more preferred.

Examples of the epoxy resin non-miscible block chain segment include at least one epoxy resin non-miscible polyether block chain segment derived from an alkylene oxide, etc. The at least one epoxy resin non-miscible polyether block chain segment derived from an alkylene oxide is preferably a polyoxyalkylene oxide block, a polyoxyhexane block derived from 1,2-epoxyhexane, a polyoxydodecane block derived from 1,2-epoxydodecane, and a mixture thereof, and preferably a polyoxybutylene oxide block.

The amphiphilic polyether block copolymer preferably has one or more epoxy resin miscible block segments, and more preferably has two or more epoxy resin miscible block segments. Similarly, it is preferred to have one or more epoxy resin non-miscible block segments, and more preferably has two or more epoxy resin non-miscible block segments. Therefore, the (E) component preferably has, for example, an epoxy resin miscible block segment selected from a diblock, a linear triblock, a linear tetrablock, a high-order multi-block structure, a branched block structure, a star-shaped block structure, and combinations thereof, or an epoxy resin non-miscible block segment.

The amphiphilic polyether block copolymer may contain other chain segments in the molecule within the range that does not impair its effect. Examples of other chain segments include polyethylene propylene (PEP), polybutadiene, polyisoprene, polydimethylsiloxane, polybutylene oxide, polyhexylene oxide, polyalkyl methyl methacrylate such as polyethylhexyl methacrylate, and mixtures thereof.

The number average molecular weight of the amphiphilic polyether block copolymer is preferably 3,000 to 20,000. The number average molecular weight is the weight average molecular weight converted to polystyrene measured by gel permeation chromatography (GPC).

Examples of amphiphilic polyether block copolymers include amphiphilic polyether triblock copolymers such as poly(ethylene oxide)-b-poly(butylene oxide) (PEO-PBO) and poly(ethylene oxide)-b-poly(butylene oxide)-b-poly(ethylene oxide) (PEO-PBO-PEO). Commercially available amphiphilic block copolymers can be used. Examples of commercially available products include "Fortegra 100" (PEO-PBO-PEO) manufactured by Dow Chemical Company.

The content of the component (E) is preferably 0.3% by mass or more, more preferably 0.4% by mass or more, and more preferably 0.5% by mass or more, when the non-volatile components in the resin composition are taken as 100% by mass, from the viewpoint of improving the breaking property, etc. The upper limit is not particularly limited as long as the effect of the present invention can be achieved, and is preferably 15% by mass or less, more preferably 10% by mass or less, and more preferably 5% by mass or less.

<(F) Elastomer> The resin composition may contain (F) elastomer as an optional component. The (F) component may be used alone or in combination of two or more.

As the component (F), a resin having one or more structures selected from the group consisting of polybutadiene structure, polysiloxane structure, poly(meth)acrylate structure, polyalkylene structure, polyalkoxylene structure, polyisoprene structure, polyisobutylene structure, and polycarbonate structure in the molecule is preferred, a resin having one or more structures selected from the group consisting of polybutadiene structure, poly(meth)acrylate structure, polyalkoxylene structure, polyisoprene structure, polyisobutylene structure, and polycarbonate structure is preferred, a resin having one or more structures selected from the group consisting of polybutadiene structure and polyalkoxylene structure is further preferred, and a resin having a polybutadiene structure is particularly preferred. Moreover, "(meth)acrylate" refers to a term including methacrylate and acrylate and combinations thereof. These structures can be included in the main chain or the side chain.

In order to reduce the warping of the resin composition after curing, the component (F) preferably has a high molecular weight. The number average molecular weight (Mn) of the component (F) is preferably 1,000 or more, preferably 1,500 or more, more preferably 3,000 or more, and 5,000 or more. The upper limit is preferably 1,000,000 or less, preferably 900,000 or less. The number average molecular weight (Mn) is the number average molecular weight measured by GPC (gel permeation chromatography) in terms of polystyrene.

From the viewpoint of reacting with the epoxy resin as the component (A) to harden the resin composition and thus improve the peel strength, the component (F) preferably has a functional group that can react with the epoxy resin as the component (A). Moreover, the functional group that can react with the epoxy resin as the component (A) also includes a functional group that appears by heating.

In a preferred embodiment, the functional group capable of reacting with the epoxy resin as component (A) is one or more functional groups selected from the group consisting of a hydroxyl group, a carboxyl group, an acid anhydride group, a phenolic hydroxyl group, an epoxy group, an isocyanate group, and a carbamate group. Among them, the functional group is preferably a hydroxyl group, an acid anhydride group, a phenolic hydroxyl group, an epoxy group, an isocyanate group, and a carbamate group, more preferably a hydroxyl group, an acid anhydride group, a phenolic hydroxyl group, and an epoxy group, and particularly preferably a phenolic hydroxyl group. However, when an epoxy group is included as a functional group, the number average molecular weight (Mn) is preferably 5,000 or more.

A suitable embodiment of the component (F) is a resin containing a polybutadiene structure. The polybutadiene structure may be contained in the main chain or in the side chain. Furthermore, a part or all of the polybutadiene structure may be hydrogenated. The resin containing the polybutadiene structure is referred to as a polybutadiene resin.

Specific examples of polybutadiene resins include "Ricon 130MA8", "Ricon 130MA13", "Ricon 130MA20", "Ricon 131MA5", "Ricon 131MA10", "Ricon 131MA17", "Ricon 131MA20", and "Ricon 184MA6" (polybutadiene containing anhydride groups) manufactured by Clay Valley Co., Ltd., "GQ-1000" (polybutadiene with hydroxyl and carboxyl groups introduced), "G-1000", "G-2000", and "G-3000" (polybutadiene with hydroxyl groups at both ends) manufactured by Nippon Soda Co., Ltd., "GI-1000", "GI-2000", and "GI-3000" (polybutadiene with hydroxyl groups at both ends), and Nagase "FCA-061L" (hydrogenated polybutadiene skeleton epoxy resin) manufactured by ChemteX Corporation, etc. As an implementation form, linear polyimide (polyimide described in Japanese Patent Publication No. 2006-37083 and International Publication No. 2008/153208), butadiene containing phenolic hydroxyl groups, etc., which uses hydroxyl-terminated polybutadiene, diisocyanate compounds and tetrabasic anhydride as raw materials, can be cited. The content of butadiene structure in the polyimide resin is preferably 60% to 95% by mass, and more preferably 75% to 85% by mass. The details of the polyimide resin can be found in Japanese Patent Application Publication No. 2006-37083 and International Publication No. 2008/153208, and the contents are incorporated into this specification.

A suitable embodiment of the component (F) is a resin containing a poly(meth)acrylate structure. A resin containing a poly(meth)acrylate structure is called a poly(meth)acrylic resin. Examples of poly(meth)acrylic resins include Teisan Resin manufactured by Nagase ChemteX, and "ME-2000", "W-116.3", "W-197C", "KG-25", and "KG-3000" manufactured by Negami Industries.

A suitable embodiment of the component (F) is a resin containing a polycarbonate structure. A resin containing a polycarbonate structure is called a polycarbonate resin. Examples of polycarbonate resins include "T6002" and "T6001" (polycarbonate diol) manufactured by Asahi Kasei Chemicals, and "C-1090", "C-2090", and "C-3090" (polycarbonate diol) manufactured by Kuraray Co., Ltd. In addition, a linear polyimide using hydroxyl-terminated polycarbonate, a diisocyanate compound, and tetrabasic anhydride as raw materials may also be used. The content of the carbonate structure of the polyimide resin is preferably 60% to 95% by mass, more preferably 75% to 85% by mass. The details of the polyimide resin can be found in International Publication No. 2016/129541, and the contents are incorporated into this specification.

In addition, as another embodiment of the component (F), a resin containing a siloxane structure is used. A resin containing a siloxane structure is referred to as a siloxane resin. Examples of siloxane resins include "SMP-2006", "SMP-2003PGMEA", "SMP-5005PGMEA" manufactured by Shin-Etsu Polysilicone Co., Ltd., and linear polyimide using amino-terminated polysiloxane and tetrabasic anhydride as raw materials (International Publication No. 2010/053185, Japanese Patent Publication No. 2002-12667, and Japanese Patent Publication No. 2000-319386).

Other embodiments of the component (F) include resins containing an alkylene structure and an alkoxylene structure. A resin containing an alkylene structure is referred to as an alkylene resin, and a resin containing an alkoxylene structure is referred to as an alkoxylene resin. The polyalkoxylene structure is preferably a polyalkoxylene structure having 2 to 15 carbon atoms, more preferably a polyalkoxylene structure having 3 to 10 carbon atoms, and more preferably a polyalkoxylene structure having 5 to 6 carbon atoms. Specific examples of the alkylene resin and the alkoxylene resin include "PTXG-1000" and "PTXG-1800" manufactured by Asahi Kasei Fibers Corporation.

Another embodiment of the component (F) is a resin containing an isoprene structure. A resin containing an isoprene structure is referred to as an isoprene resin. Specific examples of the isoprene resin include "KL-610" and "KL613" manufactured by Kuraray Co., Ltd.

Another embodiment of the component (F) is a resin containing an isobutylene structure. A resin containing an isobutylene structure is referred to as an isobutylene resin. Specific examples of the isobutylene resin include "SIBSTAR-073T" (styrene-isobutylene-styrene triblock copolymer) and "SIBSTAR-042D" (styrene-isobutylene diblock copolymer) manufactured by Kaneka Corporation.

When the non-volatile components in the resin composition are set to 100 mass %, the content of the elastomer (F) is preferably 0.1 mass % or more, more preferably 0.3 mass % or more, and more preferably 0.5 mass % or more. The upper limit is preferably 5 mass % or less, preferably 3 mass % or less, and more preferably 1 mass % or less.

＜(G) Other additives＞ In addition to the above-mentioned components, the resin composition may also contain other additives as arbitrary components. Examples of such additives include flame retardants; organic fillers such as rubber particles; organic metal compounds such as organic copper compounds, organic zinc compounds, and organic cobalt compounds; thickeners; defoamers; leveling agents; adhesion agents; colorants; and resin additives such as pigments. These additives may be used alone or in combination of two or more in any ratio. The individual contents can be appropriately set by industry professionals.

The method for preparing the resin composition is not particularly limited, and for example, a method of adding a solvent etc. to the compounding components as necessary and mixing and dispersing them using a rotary mixer etc. can be cited.

[Resin sheet] The resin sheet of the present invention comprises: a first support, and a resin composition layer releasably bonded to the first support. Usually, the first support and the resin composition layer are directly bonded. "Direct" bonding of two components means that there is no other layer between the two components being bonded. The thickness of the resin composition layer is 60 μm or more, and the ratio of the in-plane direction of one of the first support, _LA / _LB, satisfies a relationship of not less than 1.005 and not more than 1.2. The in-plane direction of the first support refers to the direction of the first support that is perpendicular to the thickness direction. In addition, _LA represents the length of the first support in the aforementioned in-plane direction when bonded to the resin composition layer. Furthermore, _LB represents the length of the first support in the aforementioned in-plane direction after the resin composition layer is peeled off. By using such a resin sheet, it is possible to suppress the appearance of the resin composition layer even if the thickness of the resin composition layer is thick. In addition, by using the resin sheet of the present invention, it is possible to suppress the occurrence of curling.

As shown in one example shown in FIG. 1 , the resin sheet 1 of the present invention comprises a first support 3 and a resin composition layer 2. As shown in one example shown in FIG. 2 , the resin sheet of the present invention may also comprise a first support 3, a resin composition layer 2, and a second support 4 in this order. The first support 3 and the second support 4 may be formed of the same material or different materials. Usually, the first support functions as a protective film.

The inventors of the present invention speculate that the mechanism for achieving the effect of the present invention is as described below. However, the technical scope of the present invention is not limited by the mechanism described below. As described above, when the thickness of the resin composition layer is thick, there is a situation where the wrinkles generated on the support body are easily transferred to the resin composition layer, thereby causing the appearance of the resin composition layer to be poor. For example, when the support body and the resin composition layer are bonded together, the support body is generally bonded by applying appropriate bonding tension. Therefore, stress corresponding to the aforementioned tension will remain on the support body. When the resin sheet is stored, if wrinkles are generated on the support body due to the aforementioned stress, the wrinkles may be transferred to the resin composition layer, resulting in poor appearance. Many resin sheets are stored in a state of being rolled up on a roll. When stored in the roll, wrinkles and poor appearance are particularly noticeable. In addition, it is believed that when the thickness of the resin composition layer is thick, stress is generated, and the wrinkles generated on the support body become easily transferred to the resin composition layer due to the stress.

The resin sheet of the present invention satisfies a specific relationship between the length _LA of the first support when it is bonded to the resin composition layer and the length _LB of the first support after the first support is peeled off from the resin composition layer in one or more in-plane directions. That is, the first support of the resin sheet of the present invention has at least one in-plane direction in which the ratio _LA / _LB satisfies a specific relationship. Since the length _LA represents the length of the first support in a state where tension is applied, and the length _LB represents the length of the first support in a state where tension is released, the aforementioned ratio _LA / _LB represents the degree of stretching of the first support caused by tension. Therefore, the aforementioned ratio _LA / _LB indirectly represents the magnitude of tension applied to the first support in a state where the first support is bonded to the resin composition layer. When the ratio L _A /L _B satisfies a specific relationship, it means that the first support is given a tension within a specific range that can suppress wrinkles during storage. Thus, even if the thickness of the resin composition layer is thick, wrinkles are suppressed from being transferred to the resin composition layer. In addition, by using the resin sheet of the present invention, curling can also be generally suppressed.

<Resin composition layer> The resin composition layer is a layer including the resin composition of the present invention, and is usually formed of a resin composition. The resin composition is as described above.

From the perspective of sealing electronic components, the thickness of the resin composition layer is 60 μm or more, preferably 80 μm or more, more preferably 100 μm or more, and even more preferably 150 μm or more. In addition, generally speaking, poor appearance tends to occur more easily when the thickness of the resin composition layer is thicker. Therefore, the thickness in the aforementioned range represents the thickness of the resin composition layer that will cause the problem of poor appearance, but from the perspective that even with a resin composition layer of such thickness, poor appearance can still be suppressed, the resin sheet of the present invention is technically significant. The upper limit of the thickness of the resin composition layer is not particularly limited, and may be, for example, less than 1000 μm, less than 500 μm, less than 300 μm, etc.

The minimum melt viscosity of the resin composition layer at 60°C to 200°C is preferably 10,000 poise or more, more preferably 2,000 poise or more, and even more preferably 3,000 poise or more, 4,000 poise or more, or 4,500 poise or more. In the case where the minimum melt viscosity is high, the rigidity of the resin composition layer becomes hard, so it is not easily affected by the wrinkle transfer from the first support. On the other hand, the upper limit of the melt viscosity is arbitrary. However, in the past, the lower the minimum melt viscosity, the more likely it is to produce a poor appearance caused by wrinkle transfer. However, through the present invention, even if a resin composition layer that is prone to poor appearance is used, the poor appearance can still be suppressed. Therefore, from the viewpoint of effectively utilizing the effect of suppressing the poor appearance that was easily produced in the past, the minimum melt viscosity is preferably low. Specifically, the aforementioned minimum melt viscosity is preferably below 20,000 poise, preferably below 15,000 poise, more preferably below 10,000 poise, or below 7,500 poise. The minimum melt viscosity can be measured using a dynamic viscoelasticity measuring device. The aforementioned minimum melt viscosity can be measured according to the method described in the embodiment described below.

As mentioned above, poor appearance is more likely to occur when the resin composition layer is thicker, and more likely to occur when the minimum melt viscosity of the resin composition layer is lower. Therefore, from the perspective of effectively utilizing the effect of suppressing poor appearance, the thickness and minimum melt viscosity of the resin composition layer are ideal to satisfy the specific relationship that has been particularly prone to poor appearance. Specifically, when the minimum melt viscosity of the resin composition layer at 60°C to 200°C is set to M (poise) and the thickness of the resin composition layer is set to T (μm), M/T is preferably 5 or more, preferably 10 or more, more preferably 15 or more, preferably 200 or less, preferably 190 or less, and more preferably 180 or less.

<First support> As the first support, for example, a film comprising a plastic material or a release paper can be cited, and a film comprising a plastic material is preferred.

When a film comprising a plastic material is used as the first support, examples of the plastic material include polyesters such as polyethylene terephthalate (hereinafter referred to as "PET") and polyethylene naphthalate (hereinafter referred to as "PEN"); polyolefins such as low-density polyethylene and unstretched polypropylene; polycarbonate (hereinafter referred to as "PC"); acrylic polymers such as polymethyl methacrylate (hereinafter referred to as "PMMA"); cyclic polyolefins; triacetyl cellulose (hereinafter referred to as "TAC"); polyether sulfide (hereinafter referred to as "PES"); polyether ketone; polyimide; polyvinyl chloride, etc. Among them, polyethylene terephthalate, polyethylene naphthalate, polyolefins and vinyl chloride are preferred, with polyolefins and vinyl chloride being particularly preferred.

The first support may be a commercially available product, such as "GF-1" manufactured by Tamapoly, "Torayfan NO9405S" manufactured by Toray Film Processing Co., Ltd., and "Type C+" manufactured by Achilles Corporation.

The surface of the first support that is bonded to the resin composition layer may also be subjected to matte treatment, corona treatment, antistatic treatment, etc.

Furthermore, as the first support, a support having a release layer on the surface bonded to the resin composition layer may be used. As the release agent used for the release layer of the support having the release layer, for example, at least one release agent selected from the group consisting of alkyd resins, polyolefin resins, urethane resins, and silicone resins may be cited. As commercially available release agents, for example, alkyd resin-based release agents such as "SK-1", "AL-5", and "AL-7" manufactured by Lintec Corporation may be cited. In addition, as a support body of the attached type layer, for example, "Lumirror T60" manufactured by Toray Industries, Ltd., "Purex" manufactured by Teijin Co., Ltd., "Unipeel" manufactured by Unitika Co., Ltd., etc. can be cited.

The L _A / L _B in the inner direction of one or more surfaces of the first support is 1.005 or more, preferably 1.01 or more, more preferably 1.05 or more, and more preferably 1.08 or more. By setting the lower limit of L _A / L _B within this range, the generation of wrinkles can be suppressed. In addition, the upper limit of L _A / L _B is 1.2 or less, preferably 1.18 or less, more preferably 1.17 or less, and more preferably 1.15 or less. By setting the upper limit of L _A / L _B within this range, the workability when making the resin sheet can be further improved.

The lengths _LA and _LB of the first support can be measured using the following method. The length _LA of the first support can be measured at a temperature of 23°C and a humidity of 70%. In addition, the length _LB of the first support can be measured at a temperature of 23°C and a humidity of 70% by using a Tensilon universal material testing machine to pull the first support apart in the thickness direction at a force of 0.008 kgf/cm, and then measuring it at the aforementioned temperature and humidity.

The number of in-plane directions of the first support that satisfy the aforementioned specific relationship of the ratio L _A /L _B may be 1 or may be 2 or more. In the case of a resin sheet having an elongated shape to the extent that it can be rolled up, the first support preferably has an in-plane direction parallel to the longitudinal direction of the resin sheet that satisfies the aforementioned specific relationship of the ratio L _A /L _B. The first support having an elongated shape is usually bonded to the resin component layer under a tension applied in the longitudinal direction. Therefore, when the first support has an in-plane direction parallel to the longitudinal direction that satisfies the aforementioned specific relationship of the ratio L _A /L _B , the tension that may cause wrinkles can be appropriately adjusted, and the appearance defect can be effectively suppressed.

The elastic modulus of the first support at 23°C is preferably 2 GPa or less, more preferably 1.8 GPa or less, more preferably 1.6 GPa or less, and preferably 0.05 GPa or more, more preferably 0.06 GPa or more, and more preferably 0.07 GPa or more. By making the elastic modulus of the first support within this range, the curling of the resin composition layer can be further suppressed. The elastic modulus can be measured by a method based on ASTM D882.

The thickness of the first support is preferably in the range of 5 μm to 75 μm, more preferably in the range of 10 μm to 60 μm. Furthermore, when a support of a release layer is used, the thickness of the entire support of the release layer is preferably in the above range.

<Second support> As shown in one example in FIG. 2, the resin sheet may also have a second support 4 in combination with the first support 3 and the resin composition layer 2. The first support 3 and the second support 4 may be formed of the same material as described above, or may be formed of different materials. From the perspective of suppressing wrinkles in the resin composition layer, it is preferred to form them of different materials.

In the case where the resin sheet has a second support, _La / _Lb of the second support in the in-plane direction of one or more of the second supports is preferably 0.95 or more, preferably 0.98 or more, more preferably 1 or more, and preferably 1.5 or less, preferably 1.3 or less, and more preferably 1.1 or less. _La represents the length of the second support in the in-plane direction when bonded to the resin component layer. And, _Lb represents the length of the second support in the in-plane direction after being peeled off from the resin component layer. When the second support has an in-plane direction having _La / _Lb within the above-mentioned range, it is particularly effective to suppress the poor appearance of the resin component layer. The lengths _La and _Lb of the second support can be measured by the same method as the lengths _LA and _LB of the first support.

The elastic modulus of the second support at 23° C. is preferably in the same range as the elastic modulus of the first support at 23° C. This makes it possible to further suppress the curling of the resin composition layer.

When the resin sheet has a first support and a second support, the difference between the elastic modulus of the first support at 23°C and the elastic modulus of the second support at 23°C (elastic modulus of the second support - elastic modulus of the first support) is preferably 2 GPa or more, more preferably 2.2 GPa or more, more preferably 2.4 GPa or more, and preferably 4 GPa or less, preferably 3.95 GPa or less, and more preferably 3.9 GPa or less. By making the difference in elastic modulus between the first and second supports within this range, the curling of the resin composition layer can be further suppressed.

<Manufacturing method of resin sheet> The resin sheet can be manufactured by a method, which includes, for example, the steps of applying a resin composition on an appropriate supporting member such as a second support to form a resin composition layer; and the step of bonding the first support to which tension has been applied to the surface of the resin composition layer that is not bonded to the second support (i.e., the surface on the opposite side to the second support) to bond the surface.

The resin composition can be applied using a coating device such as a die coater. In addition, the step of forming the resin composition layer is to dissolve the resin composition in an organic solvent to prepare a resin varnish as necessary, and then apply the resin varnish to form the resin composition layer. By using a solvent, the viscosity can be adjusted to improve the coating property. When using the resin varnish, the resin varnish is usually dried after application to form the resin composition layer.

Examples of the organic solvent include ketone solvents such as acetone, methyl ethyl ketone, and cyclohexanone; acetate solvents such as ethyl acetate, butyl acetate, solvent acetate, propylene glycol monomethyl ether acetate, and carbitol acetate; carbitol solvents such as solvent and butyl carbitol; aromatic hydrocarbon solvents such as toluene and xylene; amide solvents such as dimethylformamide, dimethylacetamide (DMAc), and N-methylpyrrolidone, etc. The organic solvent may be used alone or in combination of two or more at any ratio.

Drying can be carried out by known methods such as heating and blowing hot air. The drying conditions are such that the content of the organic solvent in the resin composition layer is usually 10% by mass or less, preferably 5% by mass or less. Although it varies depending on the boiling point of the organic solvent in the resin varnish, for example, when using a resin varnish containing 30% to 60% by mass of an organic solvent, the resin composition layer can be formed by drying at 50°C to 150°C for 3 minutes to 10 minutes.

After the resin composition layer is formed, the resin composition layer is bonded to the first support by laminating to obtain a resin sheet. The laminating is usually performed under a state where appropriate tension is applied to the first support. The tension applied to the first support is the same as the tension applied when a protective film is attached during the manufacture of a conventional resin sheet.

Again, the resin sheet can be rolled up into a roll for storage. At this time, the resin sheet is preferably rolled up inside the roll with the first support.

<Application of resin sheet> The resin sheet can be used to form an insulating layer in the manufacture of semiconductor chip packaging (resin sheet for insulating semiconductor chip packaging). For example, the resin sheet can be used to form an insulating layer of a circuit substrate (resin sheet for insulating layer of circuit substrate). Examples of packaging using such substrates include FC-CSP, MIS-BGA packaging, and ETS-BGA packaging.

Furthermore, the resin sheet can be suitably used for sealing semiconductor chips (resin sheet for semiconductor chip sealing). Examples of applicable semiconductor chip packages include fan-out type wafer level package (WLP), fan-in type wafer level package (WLP), fan-out type panel level package (PLP), and fan-in type panel level package (PLP).

Furthermore, the resin sheet can also be used as a material for MUF used after the semiconductor chip is connected to the substrate.

Furthermore, the resin sheet can be used in a wide range of other applications requiring high insulation reliability. For example, the resin sheet can be suitably used to form an insulation layer of a circuit substrate such as a printed wiring board.

<Characteristics of resin sheet> The above-mentioned resin sheet can obtain a resin composition layer in which the generation of wrinkles is suppressed. Therefore, the appearance of the resin composition layer can be suppressed. The evaluation of wrinkles is, for example, to peel off the first support body of the resin sheet cut into 50cm×50cm, and visually observe whether the resin composition layer has wrinkles. At this time, there are usually no wrinkles on the resin composition layer. The details of the evaluation of wrinkles can be carried out by the method described in the embodiment described later.

The above-mentioned resin sheet can usually obtain a resin component layer in which curling is suppressed. Therefore, it becomes possible to provide a resin sheet in which curling is suppressed. The curling is evaluated, for example, by placing the first support body of the resin sheet cut into 50cm×50cm facing upward on a flat place, and calculating and measuring the curling amount of the resin sheet. At this time, the curling amount is preferably less than 50mm. The lower limit of the curling amount is not particularly limited, and can be 0.01mm or more. The details of the curling evaluation can be carried out by the method described in the embodiment described later.

[Circuit board] The circuit board of the present invention includes an insulating layer formed by a cured product of the resin composition of the present invention. The circuit board can be manufactured by, for example, a manufacturing method including the following steps (1) and (2). (1) A step of forming a resin composition layer on a substrate. (2) A step of thermally curing the resin composition layer to form an insulating layer.

Step (1) is to prepare a substrate. As the substrate, there can be cited substrates such as glass epoxy substrates, metal substrates (stainless steel or cold-rolled steel plates (SPCC)), polyester substrates, polyimide substrates, BT resin substrates, thermosetting polyphenylene ether substrates, etc. In addition, the substrate may have a metal layer such as copper foil on the surface as a part of the substrate. For example, a substrate having a first metal layer and a second metal layer that can be peeled off on both surfaces can be used. When such a substrate is used, a conductive layer that can function as a wiring layer that can function as a circuit wiring is usually formed on the surface of the second metal layer that is opposite to the first metal layer. As the material of the metal layer, copper foil, copper foil with a carrier, the material of the conductor layer described later, etc. can be cited, and copper foil is preferred. In addition, commercial products can be used as such a base material having a metal layer, for example, ultra-thin copper foil "Micro Thin" with a carrier copper foil manufactured by Mitsui Metals & Mining Co., Ltd. can be cited.

Furthermore, a conductive layer may be formed on one or both surfaces of the substrate. In the following description, a component including a substrate and a conductive layer formed on the surface of the substrate may be appropriately referred to as a "substrate with a wiring layer". Examples of conductive materials included in the conductive layer include materials including one or more metals selected from the group consisting of gold, platinum, palladium, silver, copper, aluminum, cobalt, chromium, zinc, nickel, titanium, tungsten, iron, tin, and indium. As conductive materials, a single metal may be used, or an alloy may be used. Examples of alloys include alloys of two or more metals selected from the above group (e.g., nickel-chromium alloys, copper-nickel alloys, and copper-titanium alloys). Among them, from the perspective of versatility, cost, and ease of patterning in forming a conductive layer, single metals of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver, or copper; and alloys of nickel-chromium alloys, copper-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 metal of copper is particularly preferred.

The conductor layer may be patterned, for example, in order to function as a wiring layer. In this case, the line width (circuit width)/spacing (width between circuits) ratio of the conductor layer is not particularly limited, preferably 20/20 μm or less (i.e., pitch is 40 μm or less), preferably 10/10 μm or less, more preferably 5/5 μm or less, more preferably 1/1 μm or less, and particularly preferably 0.5/0.5 μm or more. The pitch does not need to be the same throughout the conductor layer. The minimum pitch of the conductor layer can be set, for example, to 40 μm or less, 36 μm or less, or 30 μm or less.

The thickness of the conductor layer varies according to the design of the circuit substrate, and is preferably 3 μm to 35 μm, more preferably 5 μm to 30 μm, more preferably 10 μm to 20 μm, and particularly preferably 15 μm to 20 μm.

The conductive layer can be formed, for example, by a method comprising the following steps: a step of laminating a dry film (photosensitive resist film) on a substrate; a step of exposing and developing the dry film under specified conditions using a photomask to form a pattern to obtain a patterned dry film; a step of using the developed patterned film as a plating mask and forming a conductive layer by a plating method such as electrolytic plating; and a step of peeling off the patterned dry film. As the dry film, a photosensitive dry film containing a photoresist composition can be used, and for example, a dry film formed using a resin such as a novolac resin or an acrylic resin can be used. The lamination conditions of the substrate and the dry film can be the same as the lamination conditions of the substrate and the resin sheet described later. Stripping of the dry film can be carried out using an alkaline stripping solution such as sodium hydroxide solution.

After preparing the substrate, a resin composition layer is formed on the substrate. When forming the conductor layer on the surface of the substrate, it is preferred that the resin composition layer is formed in a manner that the conductor layer is buried in the resin composition layer.

The resin composition layer is formed by laminating a resin sheet and a substrate, for example. The lamination is performed by, for example, heating and pressing the resin sheet onto the substrate so that the resin composition layer is attached to the substrate. As a component for heating and pressing the resin sheet onto the substrate (hereinafter referred to as a "heating and pressing component"), for example, a heated metal plate (SUS mirror plate, etc.) or a metal roller (SUS roller, etc.) can be cited. In addition, the heating and pressing component is not directly pressed onto the resin sheet, but preferably pressed through an elastic material such as heat-resistant rubber in a manner that the resin sheet can fully follow the surface unevenness of the substrate.

The lamination of the substrate and the resin sheet can be performed, for example, by vacuum lamination. In the vacuum lamination, the heating and pressing temperature is preferably in the range of 60°C to 160°C, more preferably in the range of 80°C to 140°C. The heating and pressing pressure is preferably in the range of 0.098MPa to 1.77MPa, more preferably in the range of 0.29MPa to 1.47MPa. The heating and pressing time is preferably in the range of 20 seconds to 400 seconds, more preferably in the range of 30 seconds to 300 seconds. The lamination is preferably performed under reduced pressure conditions with a pressure of less than 13hPa.

After lamination, the laminated resin sheet is smoothed by, for example, applying pressure, heat, and pressing the components under normal pressure (atmospheric pressure). The pressurization conditions for the smoothing treatment can be the same as the heating and pressing conditions for the lamination described above. Furthermore, the lamination and smoothing treatment can be performed continuously using a vacuum laminating machine.

The resin composition layer can be formed, for example, by compression molding. The specific operation of the compression molding method is, for example, preparing an upper mold and a lower mold as molds. Applying the resin composition on the substrate. The substrate coated with the resin composition is placed in the lower mold. Thereafter, the upper mold and the lower mold are clamped, and heat and pressure are applied to the resin composition to perform compression molding.

The specific operation of the compression molding method can be, for example, performed as follows. An upper mold and a lower mold are prepared as molds for compression molding. A resin composition is placed on the lower mold. A substrate is mounted on the upper mold. Thereafter, the upper mold and the lower mold are clamped so that the resin composition placed on the lower mold contacts the substrate mounted on the upper mold, and heat and pressure are applied to perform compression molding.

The molding conditions in the compression molding method vary according to the composition of the resin composition. The mold temperature during molding is preferably a temperature that can bring out the excellent compression molding properties of the resin composition, for example, preferably 80°C or more, preferably 100°C or more, more preferably 120°C or more, preferably 200°C or less, preferably 170°C or less, more preferably 150°C or less. In addition, the pressure applied during molding is preferably 1MPa or more, preferably 3MPa or more, more preferably 5MPa or more, preferably 50MPa or less, preferably 30MPa or less, and more preferably 20MPa or less. The curing time is preferably 1 minute or more, more preferably 2 minutes or more, particularly preferably 5 minutes or more, and preferably 60 minutes or less, preferably 30 minutes or less, and particularly preferably 20 minutes or less. Usually, the mold is removed after the resin composition layer is formed. The mold can be removed before the resin composition layer is thermally cured, or after the thermal curing.

After forming the resin composition layer on the substrate, the resin composition layer is heat-cured to form an insulating layer. Although the heat-curing conditions of the resin composition layer vary according to the type of the resin composition, the curing temperature is generally in the range of 120°C to 240°C (preferably in the range of 150°C to 220°C, more preferably in the range of 170°C to 200°C), and the curing time is in the range of 5 minutes to 120 minutes (preferably in the range of 10 minutes to 100 minutes, more preferably in the range of 15 minutes to 90 minutes).

Before the resin composition layer is heat-cured, the resin composition layer may be pre-heated at a temperature lower than the curing temperature. For example, before the resin composition layer is heat-cured, the resin composition layer may be pre-heated at a temperature of 50°C to 120°C (preferably 60°C to 110°C, and more preferably 70°C to 100°C) for 5 minutes or more (preferably 5 minutes to 150 minutes, and more preferably 15 minutes to 120 minutes).

By the above operation, a circuit substrate having an insulating layer can be manufactured. In addition, the method for manufacturing a circuit substrate may further include any steps. For example, in the case of using a resin sheet to manufacture a circuit substrate, the method for manufacturing a circuit substrate may also include the step of peeling off the first support and the second support of the resin sheet. The first support and the second support may be peeled off before the resin component layer is thermally cured, or may be peeled off after the resin component layer is thermally cured.

The manufacturing method of the circuit substrate may include, for example, a step of grinding the surface of the insulating layer after forming the insulating layer. The grinding method is not particularly limited. For example, a flat grinding disc may be used to grind the surface of the insulating layer.

The manufacturing method of the circuit substrate may also include, for example, the step (3) of connecting the conductor layers, i.e., the step of opening holes in the insulating layer. In this way, holes such as via holes and through holes can be formed in the insulating layer. Examples of methods for forming via holes include laser irradiation, etching, and mechanical drilling. The size or shape of the via hole can be appropriately determined according to the design of the circuit substrate. Furthermore, step (3) can also be performed by grinding or grinding the insulating layer to connect the layers.

After the through hole is formed, it is preferable to perform a step of removing the residue in the through hole. This step is sometimes called a deslagging step. For example, when a conductive layer is formed on an insulating layer by an electroplating step, a wet deslagging treatment may be performed on the through hole. Also, when a conductive layer is formed on an insulating layer by a sputtering step, a dry deslagging step such as a plasma treatment step may be performed. Furthermore, the insulating layer may also be roughened by the deslagging step.

Furthermore, before forming the conductive layer on the insulating layer, the insulating layer may be subjected to a roughening treatment. By the roughening treatment, the surface of the insulating layer, including the through hole, is usually roughened. As the roughening treatment, any dry roughening treatment or wet roughening treatment may be performed. As an example of dry roughening treatment, plasma treatment may be cited. Furthermore, as an example of wet roughening treatment, a method of sequentially performing a swelling treatment using a swelling liquid, a roughening treatment using an oxidizing agent, and a neutralization treatment using a neutralizing liquid may be cited.

After forming the through hole, a conductive layer is formed on the insulating layer. By forming the conductive layer at the position where the through hole is formed, the newly formed conductive layer and the conductive layer on the surface of the substrate are electrically connected to each other to form an inter-layer connection. The conductive layer can be formed by, for example, electroplating, sputtering, evaporation, etc., among which electroplating is preferred. In a suitable embodiment, the surface of the insulating layer is electroplated by a suitable method such as a semi-additive method and a full-additive method to form a conductive layer having a desired wiring pattern. In addition, when the first support or the second support in the resin sheet is a metal foil, a conductive layer having a desired wiring pattern can be formed by a subtractive method. The material of the formed conductive layer may be a single metal or an alloy. Furthermore, the conductive layer may have a single layer structure or a multi-layer structure including two or more layers of different types of materials.

Here, an example of an implementation form of forming a conductive layer on an insulating layer is described in detail. A seed layer is formed on the surface of the insulating layer by electroless plating. Next, a mask pattern is formed on the formed seed layer to expose a portion of the seed layer corresponding to a desired wiring pattern. After an electrolytic plating layer is formed on the exposed seed layer by electrolytic plating, the mask pattern is removed. Thereafter, the unnecessary seed layer can be removed by etching or the like to form a conductive layer having a desired wiring pattern. Furthermore, when forming the conductive layer, the dry film used to form the mask pattern is the same as the above-mentioned dry film.

The method for manufacturing a circuit substrate may also include a step (4) of removing the substrate. By removing the substrate, a circuit substrate having an insulating layer and a conductor layer embedded in the insulating layer can be obtained. The step (4) can be implemented, for example, when a substrate having a peelable metal layer is used.

[Semiconductor chip package] The semiconductor chip package of the first embodiment of the present invention comprises: the above-mentioned circuit substrate, and a semiconductor chip mounted on the circuit substrate. The semiconductor chip package can be manufactured by bonding the semiconductor chip to the circuit substrate.

The bonding conditions between the circuit board and the semiconductor chip can be any conditions that allow the terminal electrodes of the semiconductor chip and the circuit wiring of the circuit board to be conductively connected. For example, the conditions used in flip-chip mounting of semiconductor chips can be used. Also, for example, the semiconductor chip and the circuit board can be bonded with an insulating adhesive between them.

As an example of the bonding method, there can be cited a method of pressing a semiconductor chip onto a circuit substrate. As pressing conditions, the pressing temperature is usually in the range of 120°C to 240°C (preferably in the range of 130°C to 200°C, and more preferably in the range of 140°C to 180°C), and the pressing time is usually in the range of 1 second to 60 seconds (preferably 5 seconds to 30 seconds).

As another example of the bonding method, a method of bonding a semiconductor chip to a circuit board by reflow soldering can be cited. The reflow condition can be set in the range of 120°C to 300°C.

After the semiconductor chip is bonded to the circuit board, the semiconductor chip can be filled with a mold bottom filling material. As the mold bottom filling material, the above-mentioned resin composition can be used, and the above-mentioned resin sheet can also be used.

The semiconductor chip package of the second embodiment of the present invention comprises: a semiconductor chip, and a hardened material of the resin composition mentioned above for sealing the semiconductor chip. In such semiconductor chip package, the hardened material of the resin composition generally functions as a sealing layer. As the semiconductor chip package of the second embodiment, for example, a fan-out type wafer level package (WLP) can be cited.

The manufacturing method of the semiconductor chip package of the fan-out type wafer level package (WLP) includes: (A) a step of laminating a temporary fixing film on a substrate, (B) a step of temporarily fixing a semiconductor chip on the temporary fixing film, (C) laminating the resin composition of the resin sheet of the present invention on the semiconductor chip, or coating the resin composition of the present invention on the semiconductor chip , and heat-harden it to form a sealing layer, (D) a step of peeling off the substrate and the temporary fixing film from the semiconductor chip, (E) a step of forming a redistribution formation layer (insulating layer) on the surface of the semiconductor chip from which the substrate and the temporary fixing film have been peeled off, (F) a step of forming a conductor layer (redistribution layer) on the redistribution formation layer (insulating layer), and (G) a step of forming a solder resist layer on the conductor layer. In addition, the manufacturing method of the semiconductor chip package can also include: (H) a step of cutting a plurality of semiconductor chip packages into individual semiconductor chip packages and singulating them.

The detailed contents of the manufacturing method of the semiconductor chip package can be found in paragraphs 0066 to 0081 of International Publication No. 2016/035577, and the contents are incorporated into this specification.

The semiconductor chip package of the third embodiment of the present invention is a semiconductor chip package in which, for example, in the semiconductor chip package of the second embodiment, a redistribution layer or a solder resist layer is formed by using a cured product of the resin composition of the present invention.

[Semiconductor device] As the semiconductor device implementing the semiconductor chip package mentioned above, for example, various semiconductor devices provided in electrical products (for example, computers, mobile phones, smart phones, tablet devices, wearable devices, digital cameras, medical devices, and televisions, etc.) and transportation vehicles (for example, motorcycles, cars, trains, ships, and aircraft, etc.) can be cited. [Example]

The following examples are presented to specifically illustrate the present invention. However, the present invention is not limited to the following examples. In the following description, "parts" and "%" representing quantities, when not otherwise clearly defined, mean "parts by mass" and "% by mass", respectively. In addition, the operations described below, when not otherwise clearly defined, are performed under normal temperature and pressure.

(Synthesis of synthetic resin A) In a flask equipped with a stirrer, a thermometer and a condenser, 368.41 g of ethyl diglycol acetate and 368.41 g of SOLVESSO 150 (aromatic solvent, manufactured by Exxon Mobil) as a solvent, 100.1 g (0.4 mol) of diphenylmethane diisocyanate and 400 g (0.2 mol) of polycarbonate diol (number average molecular weight: about 2000, hydroxyl equivalent: 1000, non-volatile matter: 100%, "C-2015N" manufactured by Kuraray Co., Ltd.) were added, and the reaction was carried out at 70°C for 4 hours. Next, 195.9 g (0.2 mol) of nonylphenol novolac resin (hydroxyl equivalent 229.4 g/eq, average 4.27 functional groups, average calculated molecular weight 979.5 g/mol) and 41.0 g (0.1 mol) of ethylene glycol dianhydrous trimellitate were added, and the temperature was raised to 150°C over 2 hours, and the mixture was reacted for 12 hours. The disappearance of the NCO peak at 2250 cm ^-1 was confirmed by FT-IR. After the disappearance of the NCO peak was confirmed, the reaction was considered to have ended. After the reactants were cooled to room temperature, they were filtered using a 100 mesh filter cloth to obtain a resin having a polycarbonate structure (non-volatile components 50% by mass). The number average molecular weight of the obtained resin (synthetic resin A) was 6100.

(Preparation of Silica A) Spherical silica A was obtained by surface-treating spherical silica having an average particle size of 3 μm and a specific surface area of 4.4 m ² /g using KBM-573 (manufactured by Shin-Etsu Chemical Co., Ltd.).

(Preparation of resin varnish 1) 10 parts of epoxy resin ("ZX1059" manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd., a 1:1 mixture of bisphenol A epoxy resin and bisphenol F epoxy resin (mass ratio, epoxy equivalent: 169 g/eq.), 41 parts of biphenyl epoxy resin ("NC3000L" manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent 269 g/eq.), and amphiphilic polyether block copolymer ("Fortegra 100”), 3 parts of spherical silica (average particle size 0.5 μm, “SO-C2” manufactured by Admatex) surface treated with a phenylaminosilane coupling agent (“KBM573” manufactured by Shin-Etsu Chemical Co., Ltd.), 380 parts of phenol novolac resin (phenolic hydroxyl equivalent 105, “TD2090-60M” manufactured by DIC Corporation, solid content 60 mass % MEK solution) 8.3 parts, phenoxy resin ("YX7553BH30" manufactured by Mitsubishi Chemical Corporation, a 1:1 solution of cyclohexanone:methyl ethyl ketone (MEK) with a solid content of 30% by mass) 16.6 parts, methyl ethyl ketone 30 parts, and imidazole curing accelerator ("1B2PZ" manufactured by Shikoku Chemical Co., Ltd.) 0.3 parts were mixed and uniformly dispersed using a high-speed rotary mixer to prepare a resin varnish 1.

(Preparation of resin varnish 2) 2 parts of synthetic resin A, rubber particles ("PARALOID EXL-2655") 2 parts, naphthalene type epoxy resin ("ESN-475V" manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd., epoxy equivalent of about 332g/eq.) 3 parts, liquid epoxy resin ("ZX1059" manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd., a 1:1 mixture of bisphenol A type epoxy resin and bisphenol F type epoxy resin (mass ratio), epoxy equivalent of 169g/eq.) 6 parts, phenol novolac type curing agent containing triazine skeleton ("LA-7054" manufactured by DIC Corporation, hydroxyl equivalent of 125g/eq., MEK solution with non-volatile components of 60%) 8.3 parts, silica A 125 parts of 2-phenyl-4-methylimidazole, 0.1 part of a curing accelerator (2-phenyl-4-methylimidazole, "2P4MZ" manufactured by Shikoku Chemical Industries, Ltd.), 10 parts of methyl ethyl ketone (MEK), and 8 parts of cyclohexanone were mixed and uniformly dispersed using a high-speed rotary mixer to prepare a resin varnish 2.

<Measurement of elastic modulus of support> The support was cut into a dumbbell No. 1 shape to obtain a test piece. The tensile strength of the test piece was measured using a tensile tester "RTC-1250A" manufactured by Orientec, and the elastic modulus at 23°C was obtained. The measurement was carried out in accordance with JIS K7127. This operation was performed three times and the average value is shown in the following table.

<Example 1> On the release surface of a 38μm thick PET film (second support, Lintec, "AL5", elastic modulus at 23°C: 4GPa) that had been subjected to release treatment, resin varnish 1 was applied using a die coater in such a manner that the thickness after drying became 200μm. After coating, the resin composition layer was formed by drying at 75-120°C for 12 minutes.

Next, a first support (low-density polyethylene, manufactured by Tamapoly, "GF-1", 30 μm thick, elastic modulus at 23°C 0.24 GPa) was bonded to the surface of the resin composition layer and rolled into a roll for 50 m with the support facing inside to produce a resin sheet.

<Example 2> In Example 1, resin varnish 1 was replaced by resin varnish 2, and the first support (low-density polyethylene, manufactured by Tamapoly, "GF-1", elastic modulus at 23°C was 0.24 GPa) was replaced by the first support (unstretched polypropylene, manufactured by Toray Film Processing Co., Ltd., "Torayfan NO9405S", elastic modulus at 23°C was 0.72 GPa). Except for the above matters, the resin sheet was prepared in the same manner as in Example 1.

<Example 3> In Example 1, the first support (low-density polyethylene, manufactured by Tamapoly, "GF-1", elastic modulus at 23°C is 0.24 GPa) is replaced with the first support (polyvinyl chloride, manufactured by Achilles, "Type C+", elastic modulus at 23°C is 0.25 GPa), and dried at 75-120°C for 14 minutes. Except for the above matters, the resin sheet is produced in the same manner as in Example 1.

<Example 4> In Example 1, resin varnish 1 is replaced with resin varnish 2, and after applying resin varnish 2, it is dried at 75-120°C for 10 minutes. Except for the above matters, the other operations are the same as those in Example 1 to produce a resin sheet.

<Comparative Example 1> In Example 1, the first support (low-density polyethylene, manufactured by Tamapoly, "GF-1", elastic modulus at 23°C is 0.24 GPa) is replaced by the first support (polyethylene terephthalate, manufactured by Lintec, "AL-5", elastic modulus at 23°C is 4 GPa), and dried at 75-120 for 8 minutes. Except for the above matters, the resin sheet is produced in the same manner as in Example 1.

<Comparative Example 2> In Example 1, the first support (low-density polyethylene, manufactured by Tamapoly, "GF-1", elastic modulus at 23°C is 0.24 GPa) is replaced by the first support (biaxially oriented polypropylene, manufactured by Prince Aifute, "Alphan MA-411", elastic modulus at 23°C is 2 GPa). Drying is performed at 75-120°C for 7 minutes. Except for the above matters, the resin sheet is produced in the same manner as in Example 1.

<Measurement of the minimum melt viscosity of the resin composition layer> For the resin composition layer of the resin sheet, the minimum melt viscosity was measured using a dynamic viscoelasticity measuring device ("Rheosol-G3000" manufactured by UBM). For 1g of the sample resin composition taken from the resin composition layer, the temperature was raised at a rate of 5°C/min from a starting temperature of 60°C to 200°C using a parallel plate with a diameter of 18mm. The dynamic viscoelastic modulus was measured under the measurement conditions of a temperature interval of 2.5°C, a vibration rate of 1Hz, and a deformation of 1deg, and the minimum melt viscosity (poise) was measured.

<Measurement of the lengths _LA and _LB of the support> The resin sheet was pulled out 50 cm and cut into 50 cm × 50 cm. The winding direction of the cut resin sheet was regarded as the length of the first support, and the measurement was performed under the conditions of temperature 23°C and humidity 70%, and this was taken as the length _LA of the first support. Then, under the conditions of temperature 23°C and humidity 70%, the first support was peeled off by pulling with a force of 0.008 kgf/cm in the thickness direction of the first support using a Tensilon universal material testing machine, and the length of the first support in the winding direction after peeling was measured, and this was taken as the length _LB of the first support, and the value of _LA / _LB was calculated.

<Evaluation of wrinkles> Pull out the resin sheet 50 cm and cut it into 50 cm × 50 cm. Peel off the first support of the cut resin sheet and visually check whether the resin composition layer has wrinkles. Those with wrinkles and poor appearance are rated as "×", and those without wrinkles and good appearance are rated as "0".

<Evaluation of curl> Pull out the resin sheet 50cm and cut it into 50cm×50cm. Place the 38μm thick PET film that has been subjected to release treatment face down on a flat surface and check the curl of the resin sheet. The curl of 50mm or more is rated as "×", and the curl of less than 50mm is rated as "0".

1: Resin sheet 2: Resin component layer 3: First support 4: Second support

[Figure 1] Figure 1 is a schematic cross-sectional view of the resin sheet of the present invention. [Figure 2] Figure 2 is a schematic cross-sectional view of the resin sheet of the present invention.

Claims (7)

A resin sheet comprises: a first support, a resin composition layer bonded to the first support, and a second support, wherein the difference between the elastic modulus of the first support at 23°C and the elastic modulus of the second support at 23°C (elastic modulus of the second support - elastic modulus of the first support) is greater than 2 GPa and less than 4 GPa, the thickness of the resin composition layer is greater than 60 μm, and the ratio _LA / _LB of one or more in-plane directions of the first support satisfies a relationship of greater than 1.005 and less than 1.2; _LA represents the length of the first support in the in-plane direction when bonded to the resin composition layer, and _LB represents the length of the first support in the in-plane direction after being peeled off from the resin composition layer. The resin sheet of claim 1, wherein the resin sheet comprises a first support, a resin component layer, and a second support in this order. For example, the resin sheet of claim 1, wherein the minimum melting viscosity of the resin component layer at 60°C to 200°C is greater than 1000 poise and less than 20000 poise. For example, in the resin sheet of claim 1, when the minimum melt viscosity of the resin composition layer at 60°C to 200°C is set to M (poise), and the thickness of the resin composition layer is set to T (μm), M/T satisfies the relationship of 5 or more and 200 or less. A circuit substrate comprising an insulating layer formed by hardening a resin composition layer in a resin sheet as recited in any one of claims 1 to 4. A semiconductor chip package, comprising: a circuit substrate as claimed in claim 5, and a semiconductor chip mounted on the aforementioned circuit substrate. A semiconductor chip package, comprising: a semiconductor chip, and a hardened resin composition layer in a resin sheet as described in any one of claims 1 to 4 that seals the semiconductor chip.

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