TW201545868A - Resin sheet with support - Google Patents

Abstract

The present invention provides a technique capable of forming an insulating layer showing an excellent peel strength for a conductive layer after a roughness treatment while maintaining characteristics of a bulk, known to have a high content of an inorganic filler. A resin sheet attached with a support comprises: a support; and a resin composition layer containing an inorganic filler having 50 wt% or more and being in contact with the support. In a cross-section of the resin composition layer in the perpendicular direction of the surface of the support, the resin sheet attached with a support satisfies a relationship of A0-1/A1-2 > 1.1 wherein a resin area A0-1 is for an area having a distance of 0 to 1 [mu]m from a boundary of the support and the resin composition layer and wherein a resin area A1-2 is for an area having a distance of 1 to 2 [mu]m from the boundary.

Description

Resin sheet with support

The present invention relates to a resin sheet with a support.

As a manufacturing technique of a printed circuit board, a manufacturing method of a build-up method in which an insulating layer and a conductor layer are alternately stacked is known. In the production method by the build-up method, the resin composition is generally thermally cured to form an insulating layer. For example, Patent Document 1 discloses a technique in which a resin sheet containing a support and a resin composition layer containing cerium oxide particles provided on a support is laminated, and the resin composition is laminated on the resin composition. After the inner layer substrate, the resin composition layer is thermally cured, and the obtained hardened body is subjected to a roughening treatment to form an insulating layer.

In the pursuit of further higher density of circuit wiring, there is a tendency to increase the number of layers of the printed circuit board, but as the number of layers increases, there is a crack due to the difference in thermal expansion between the insulating layer and the conductor layer. Or the problem of circuit distortion. As a technique for suppressing the problem of the crack or the distortion of the circuit, for example, Patent Document 2 discloses a technique in which the content of the inorganic filler such as cerium oxide particles in the resin composition is increased. The thermal expansion rate of the insulating layer is suppressed to be low.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] International Publication No. 2010/35451

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2010-202865

In the technique described in Patent Document 1, the ruthenium dioxide particles on the surface of the hardened body are detached by the roughening treatment, whereby an insulating layer exhibiting sufficient peeling strength to the conductor layer can be realized. However, in order to form a resin composition having a high content of an inorganic filler such as cerium oxide particles in order to form an insulating layer having a low coefficient of thermal expansion, even if this technique is used, the insulating layer and the conductor layer which are formed are unavoidable. The case where the peel strength is lowered.

An object of the present invention is to provide a technique capable of maintaining a bulk property of a high content of an inorganic filler and forming an insulating layer which exhibits excellent peel strength to a conductor layer after roughening treatment.

As a result of intensive studies on the above-mentioned problems, the present inventors have found that the above problems can be solved by using a resin sheet with a support having a resin composition layer, and the resin composition layer is on the side surface of the support. Inorganic fillers and resin components in the nearby area The amount ratio (inorganic filler/resin component) has a resin composition layer having a gradient (that is, a positive gradient from a bonding surface of the support to a thickness direction or more).

That is, the present invention includes the following contents.

[1] A resin sheet with a support comprising: a support, and a resin composition layer bonded to the support and having an inorganic filler content of 50% by mass or more, in a direction perpendicular to the surface of the support In the cross section of the composition layer, the resin area A _0-1 of the region from the boundary between the support and the resin composition layer from 0 μm to 1 μm, and the resin area of the region from the above boundary to the range of from 1 μm to 2 μm A _1-2 satisfies the following relationship: A _0-1 /A _1-2 >1.1.

[2] A resin sheet with a support comprising: a support, and a resin composition layer bonded to the support and having an inorganic filler content of 50% by mass or more, in a direction perpendicular to the surface of the support In the cross section of the composition layer, the resin area A _0-0.5 in the region from the boundary between the support and the resin composition layer from 0 μm to 0.5 μm and the region from the above boundary are from 0.5 μm to 1 μm. The resin area A _0.5-1 satisfies the following relationship: A _0-0.5 /A _0.5-1 >1.1.

[3] The resin sheet with a support according to [1] or [2], wherein the self-supporting body and the resin composition layer are in a cross section of the resin composition layer in a direction perpendicular to the surface of the support body. The resin area A _0.5-d in the region from the range of 0.5 μm to d μm and the resin area A _d-0.5D in the region from the above boundary to the range of _d μm to 0.5 D μm satisfy the following relationship: 0.9≦kA _{0.5- d} /A _d-0.5D ≦ 1.1 (here, k is a coefficient satisfying k=|d-0.5D|/|0.5-d|, d is a number satisfying 0.5<d<0.5D, D-type resin composition The thickness of the layer).

[4] A method for producing a resin sheet with a support comprising the steps of: forming a first layer having a thickness of less than 2 μm from the first resin composition and a second layer formed of the second resin composition The layers are bonded to each other to form an integrated resin composition layer, and the content of the inorganic filler in the resin composition layer is 50% by mass or more, and the surface of the resin composition layer from the side of the first layer is bonded to the support. In the cross section of the resin composition layer in the direction perpendicular to the surface of the support, the resin area A _0-1 of the region from the boundary between the support and the resin composition layer is from 0 μm to 1 μm, and from the above-mentioned boundary The resin area A _1-2 of the region from the range of 1 μm to 2 μm satisfies the following relationship: A _0-1 /A _1-2 >1.1.

[5] The method according to [4], wherein the step of forming the resin composition layer comprises: (A1) a step of preparing a temporary resin sheet with a support, the temporary resin sheet containing a support, and a first layer of a support having a thickness of less than 2 μm formed by the first resin composition; and (B1) applying a second resin composition to the first layer, and coating The film is dried to provide a second layer to form an integrated resin composition layer.

[6] The method according to [4] or [5] wherein the thickness of the first layer is less than 1 μm.

[7] The method according to any one of [4], wherein the first resin composition contains an inorganic filler having an average particle diameter of 500 nm or less.

[8] The method according to any one of [4], wherein the content of the inorganic filler in the first resin composition is 40% by mass or less.

[9] The method according to any one of [4] to [8] wherein the content of the inorganic filler in the second resin composition is more than 50% by mass.

[10] A printed circuit board comprising: an insulating layer formed using the resin sheet with a support according to any one of [1] to [3].

[11] A semiconductor device comprising: the printed circuit board according to [10].

According to the resin sheet with a support of the present invention, it is possible to maintain a high volume content of the inorganic filler and to provide an insulating layer which exhibits excellent peel strength to the conductor layer after the roughening treatment.

0‧‧‧The boundary between the support and the resin layer

10‧‧‧Support

20‧‧‧ resin composition layer

Area from 21a‧‧d1 to d2

21b‧‧d2 to d3

D1‧‧‧established distance

D2‧‧‧established distance

D3‧‧‧established distance

Fig. 1 is a schematic view for explaining a method of calculating a resin area ratio (kA _{d1 - d2} / A _{d2 - d3} ratio).

Before the detailed description of the resin sheet with the support of the present invention, the "first resin composition" and "the first resin composition" used in forming the resin composition layer contained in the resin sheet with the support of the present invention are described. The second resin composition will be described.

<First Resin Composition>

The first resin composition is used in the composition layer to form a region in the vicinity of the joint surface of the support.

The first resin composition is not particularly limited as long as a resin composition layer having a desired composition gradient is obtained, and the cured product may have sufficient hardness and insulation properties. As the resin composition, for example, a composition containing a curable resin and a curing agent thereof can be given. As the curable resin, a conventionally known curable resin used in forming an insulating layer of a printed circuit board can be used, and an epoxy resin is preferable. Therefore, in one embodiment, the first resin composition comprises (a) an epoxy resin and (b) a hardener. The first resin composition may further contain additives such as (c) an inorganic filler, (d) a thermoplastic resin, (e) a curing accelerator, (f) a flame retardant, and (g) rubber particles, if necessary.

Hereinafter, an epoxy resin, a curing agent, and an additive which can be used as a material of the first resin composition will be described.

- (a) epoxy resin -

Examples of the epoxy resin include bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, bisphenol AF epoxy resin, and dicyclopentadiene epoxy resin. Resin, trisphenol epoxy resin, naphthol novolak epoxy resin, phenol novolak epoxy resin, tert-butyl-catechol epoxy resin, naphthalene epoxy resin, naphthol ring Oxygen resin, onion type epoxy resin, glycidylamine based epoxy resin, glycidyl ester type epoxy resin, cresol novolak type epoxy resin, biphenyl type epoxy resin, linear aliphatic epoxy resin, Butadiene structure epoxy resin, alicyclic epoxy resin, heterocyclic epoxy resin, epoxy resin containing spiro ring, cyclohexane dimethanol type epoxy resin, naphthene ether type epoxy resin and three Hydroxymethyl epoxy resin and the like. The epoxy resins may be used alone or in combination of two or more.

The epoxy resin preferably contains an epoxy resin having two or more epoxy groups in one molecule. When the nonvolatile component of the epoxy resin is 100% by mass, at least 50% by mass or more of the epoxy resin having two or more epoxy groups in one molecule is preferable. Further, it contains an epoxy resin having two or more epoxy groups in one molecule and being liquid at a temperature of 20 ° C (hereinafter referred to as "liquid epoxy resin"), and three in one molecule. The above epoxy group is preferably a solid epoxy resin (hereinafter referred to as "solid epoxy resin") at a temperature of 20 ° C. As the epoxy resin, a resin composition having excellent flexibility can be obtained by using a liquid epoxy resin together with a solid epoxy resin. And insulating the resin composition to harden The breaking strength of the layer is also increased.

As the liquid epoxy resin, bisphenol A epoxy resin, bisphenol F epoxy resin, phenol novolac epoxy resin, and naphthalene epoxy resin are preferred, and bisphenol A epoxy resin is used. The bisphenol F type epoxy resin and the naphthalene type epoxy resin are preferable, and the bisphenol A type epoxy resin and the bisphenol F type epoxy resin are more preferable. Specific examples of the liquid epoxy resin include "HP4032", "HP4032D", "HP4032SS" (naphthalene epoxy resin) manufactured by DIC Co., Ltd., and "jER828EL" manufactured by Mitsubishi Chemical Corporation. "Bisphenol A type epoxy resin", "jER807" (bisphenol F type epoxy resin), "jER152" (phenol novolak type epoxy resin), "ZX1059" made by Shinji Izumi Metal Chemical Co., Ltd. ( "A mixture of a bisphenol A type epoxy resin and a bisphenol F type epoxy resin" and "EX-721" (glycidyl type epoxy resin) manufactured by Nagase Chemtex Co., Ltd. These may be used alone or in combination of two or more.

As the solid epoxy resin, a naphthalene type tetrafunctional epoxy resin, a cresol novolak type epoxy resin, a dicyclopentadiene type epoxy resin, a trisphenol type epoxy resin, a naphthol novolac type epoxy resin A biphenyl type epoxy resin or a naphthene ether type epoxy resin is preferred, and a naphthalene type 4-functional epoxy resin, a biphenyl type epoxy resin, or a naphthene ether type epoxy resin is preferred, and a naphthalene type 4 is preferred. A functional epoxy resin or a biphenyl type epoxy resin is more preferable. Examples of the solid epoxy resin include "HP-4700" manufactured by DIC Co., Ltd., "HP-4710" (naphthalene type 4-functional epoxy resin), and "N-690" (cresol novolac type). Epoxy resin), "N-695" (cresol novolac type epoxy resin), "HP-7200" (dicyclopentadiene type epoxy resin), "EXA7311", "EXA7311-G3", "EXA7311-G4", "EXA7311-G4S", "HP6000" (Naphthyl Ether Epoxy Resin), and "EPPN-502H" made by Nippon Kayaku Co., Ltd. (3) Phenol epoxy resin), "NC7000L" (naphthol novolac epoxy resin), "NC3000H", "NC3000", "NC3000L", "NC3100" (biphenyl type epoxy resin), Nippon Steel & Sumitomo Chemical Co., Ltd. "ESN475" (naphthol novolak type epoxy resin), "ESN485V" (naphthol novolac type epoxy resin), "YX4000H" and "YL6121" (Biphenyl type ring) manufactured by Mitsubishi Chemical Corporation "Oxygen resin", "YX4000HK" (bis-dimethylphenol type epoxy resin), "PG-100" manufactured by Osaka Gas Chemical Co., Ltd., "CG-500", and "YL7800" manufactured by Mitsubishi Chemical Corporation芴 type epoxy resin).

As the epoxy resin, when a liquid epoxy resin and a solid epoxy resin are used in combination, the ratio (liquid epoxy resin: solid epoxy resin) is in a mass ratio of 1:0.1 to 1:5. It is better. By setting the ratio of the liquid epoxy resin to the solid epoxy resin in this range, the following effects can be obtained: i) moderate adhesion can be obtained when the resin sheet is used; ii) resin sheet type In the state of use, sufficient flexibility is obtained to improve workability; and iii) an insulating layer having sufficient breaking strength can be obtained. From the viewpoint of the effects of the above i) to iii), the ratio of the liquid epoxy resin to the solid epoxy resin (liquid epoxy resin: solid epoxy resin) is a mass ratio of 1:0.3-1. The range of 4.5 is better, preferably in the range of 1:0.6 to 1:4, and particularly preferably in the range of 1:0.8 to 1:4.

The content of the epoxy resin in the first resin composition is 5 The mass% or more is more preferably 10% by mass or more, more preferably 20% by mass or more or 30% by mass or more. The upper limit of the content of the epoxy resin is not particularly limited, and is preferably 99% by mass or less, more preferably 95% by mass or less, still more preferably 90% by mass or less, 85% by mass or less, 80% by mass or less, or 75% by mass or less. 70% by mass or less.

In the present invention, the content of each component constituting the resin composition is a value obtained by setting the total of the nonvolatile components in the resin composition to 100% by mass.

The epoxy equivalent of the epoxy resin is preferably from 50 to 3,000, more preferably from 80 to 2,000, still more preferably from 110 to 1,000. In this range, an insulating layer having a sufficient crosslink density of the cured product and a small surface roughness can be obtained. Further, the epoxy equivalent can be measured in accordance with JIS K7236 and is a mass of a resin containing one equivalent of an epoxy group.

The weight average molecular weight of the epoxy resin is preferably from 100 to 5,000, more preferably from 250 to 3,000, still more preferably from 400 to 1,500. Here, the weight average molecular weight of the epoxy resin is a polystyrene-equivalent weight average molecular weight measured by a gel permeation chromatography (GPC) method.

- (b) hardener -

The curing agent is not particularly limited as long as it has a function of curing the epoxy resin, and examples thereof include a phenol-based curing agent, a naphthol-based curing agent, an active ester-based curing agent, and a benzoxazine-based curing agent. Cyanate-based hardener. The hardener may be used alone or in combination of two or more.

Heat resistant as a phenolic hardener and a naphthol hardener From the viewpoint of the properties and water resistance, a phenol-based curing agent having a novolak structure or a naphthol-based curing agent having a novolak structure is preferred. Further, from the viewpoint of adhesion to the conductor layer, a phenol-based curing agent containing a nitrogen-containing phenol-based curing agent and containing a triazine skeleton is more preferable. Among them, a phenol novolak resin containing a triazine skeleton is preferred from the viewpoint of highly satisfying heat resistance, water resistance, and adhesion to a conductor layer (peeling strength).

Specific examples of the phenol-based curing agent and the naphthol-based curing agent include "MEH-7700", "MEH-7810", "MEH-7851", and Nippon Chemical Co., Ltd., manufactured by Megumi Kasei Co., Ltd. "SNN", "SNH", "SN180", "SN190", "SN475", "SN485", "SN495", "SN375", "NHN", "CBN", "GPH", and Dongdu Chemicals Co., Ltd. "SN395", DIC (share) system "LA7052", "LA7054", "LA3018", etc.

From the viewpoint of obtaining an insulating layer having a small surface roughness after the roughening treatment, an active ester-based curing agent is also preferable. The active ester-based curing agent is not particularly limited, and it is generally preferred to use an ester having two or more phenol esters, thiophenol esters, N-hydroxylamine esters, and heterocyclic hydroxy compounds in one molecule. An ester group having a high reactivity. The active ester-based curing agent is preferably obtained by a condensation reaction of a carboxylic acid compound and/or a sulfurized carboxylic acid compound with a hydroxy compound and/or a thiol compound. In particular, from the viewpoint of improving heat resistance, an active ester-based curing agent obtained from a carboxylic acid compound and a hydroxy compound is preferred, and an active ester-based curing agent obtained from a carboxylic acid compound and a phenol compound and/or a naphthol compound is more preferable. . Examples of the carboxylic acid compound include benzoic acid, acetic acid, succinic acid, maleic acid, itaconic acid, and o Phthalic acid, isophthalic acid, terephthalic acid, pyromellitic acid, and the like. Examples of the phenol compound or the naphthol compound include hydroquinone, resorcin, bisphenol A, bisphenol F, bisphenol S, phenolphthalein phosphorus, methylated bisphenol A, and 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 diphenol Compound, phenol novolak, etc. Here, the "dicyclopentadiene type diphenol compound" means a diphenol compound obtained by condensing two molecules of phenol in one molecule of dicyclopentadiene.

Specifically, an active ester compound containing a dicyclopentadiene type diphenol structure, an active ester compound containing a naphthalene structure, an active ester compound containing an acetal of a phenol novolak, and a benzamidine group containing a phenol novolac The active ester compound of the compound is preferably further selected from the group consisting of an active ester compound containing a naphthalene structure and an active ester compound containing a dicyclopentadiene type diphenol structure. The "dicyclopentadiene type diphenol structure" means a divalent structural unit derived from a phenyl-dicyclopentadiene-phenylene group.

In the commercial product of the active ester-based curing agent, "EXB9451", "EXB9460", "EXB9460S", and "HPC-8000-65T" are mentioned as the active ester compound containing a dicyclopentadiene type diphenol structure. (DIC), as an active ester compound containing a naphthalene structure, "EXB9416-70BK" (manufactured by DIC Co., Ltd.), and an active ester compound containing an acetal of a phenol novolak may be mentioned. "DC808" (Mitsubishi Chemical Co., Ltd.) as a phenolic phenolic aldehyde The YLH1026 (manufactured by Mitsubishi Chemical Corporation) and the like are exemplified as the active ester compound of the benzamidine compound of the varnish.

Specific examples of the benzoxazine-based curing agent include "HFB2006M" manufactured by Showa Polymer Co., Ltd., and "P-d" and "F-a" manufactured by Shikoku Chemical Industries Co., Ltd.

Examples of the cyanate-based curing agent include bisphenol A dicyanate, polyphenol cyanate, oligo(3-methylene-1,5-phenylphenylcyanate), and 4,4. '-Methylene bis(2,6-dimethylphenylcyanate), 4,4'-ethylenediphenyl dicyanate, hexafluorobisphenol A dicyanate, 2,2 - bis(4-cyanate) phenylpropane, 1,1-bis(4-cyanate phenylmethane), bis(4-cyanate-3,5-dimethylphenyl)methane, 1,3 - bis(4-cyanate phenyl-1-(methylethylidene)) benzene, bis(4-cyanate phenyl) sulfide, and bis(4-cyanate phenyl) ether A bifunctional cyanate resin, a polyfunctional cyanate resin derived from a phenol novolak, a cresol novolak or the like, a prepolymer having a triazine-based part of the cyanate resin, and the like. Specific examples of the cyanate-based curing agent include "PT30" and "PT60" manufactured by Lonza Japan Co., Ltd. (all of which are phenol novolac type polyfunctional cyanate resins), and "BA230" (bisphenol). A part or all of the A dicyanate is triazine-formed into a trimeric prepolymer).

The ratio of the epoxy resin to the hardener is preferably in the range of 1:0.2 to 1:2 in the ratio of [the total number of epoxy groups of the epoxy resin]: [the total number of the reactive groups of the curing agent]. 1:0.3~1:1.5 is better, and 1:0.4~1:1.2 is better. Here, the reactive group of the curing agent means an active hydroxyl group, an active ester group, or the like, and varies depending on the type of the curing agent. Further, the total number of epoxy groups of the epoxy resin is a value obtained by dividing the solid content of each epoxy resin by the value of the epoxy equivalent in all the epoxy resins, and the total of the reactive groups of the curing agent. The number is a value obtained by dividing the solid content of each hardener by the value of the reactive base equivalent in all the hardeners. When the ratio of the amount of the epoxy resin to the curing agent is in this range, the heat resistance of the cured product of the resin composition is further improved.

In one embodiment, the first resin composition contains the above (a) epoxy resin and (b) a curing agent. The first resin composition preferably contains: (a) a mixture of a liquid epoxy resin as an epoxy resin and a solid epoxy resin (liquid epoxy resin: solid epoxy resin mass ratio is 1 : The range of 0.1~1:5 is better, the range of 1:0.3~1:4.5 is better, the range of 1:0.6~1:4 is better, and the range of 1:0.8~1:4 is further better. And (b) one or more selected from the group consisting of a phenolic curing agent, a naphthol curing agent, an active ester curing agent, and a cyanate curing agent as a curing agent (preferably, a phenol system) One or more selected from the group consisting of a hardener, a naphthol-based hardener, and an active ester-based hardener.

- (c) Inorganic filling materials -

The first resin composition may further contain an inorganic filler. Examples of the inorganic filler include cerium oxide, aluminum oxide, glass, cordierite, cerium oxide, barium sulfate, talc, clay, mica powder, aluminum hydroxide, magnesium hydroxide, calcium carbonate, and magnesium carbonate. Magnesium oxide, boron nitride, aluminum nitride, manganese nitride, aluminum borate, barium titanate, barium titanate, calcium titanate, titanic acid Magnesium, barium titanate, titanium oxide, barium zirconate, calcium zirconate, zirconium phosphate, zirconium tungstate phosphate, and the like. Among them, it is particularly suitable for use: amorphous cerium oxide, molten cerium oxide, crystalline cerium oxide, synthetic cerium oxide, hollow cerium oxide or the like. Further, as the cerium oxide, spherical cerium oxide is preferred. The inorganic filler may be used singly or in combination of two or more.

The average particle diameter of the inorganic filler used in the first resin composition is not particularly limited as long as a resin composition layer having a desired composition gradient can be obtained, but is preferably 500 nm or less, preferably 300 nm or less. More preferably, it is 200 nm or less, and further more preferably 150 nm or less, 100 nm or less, 90 nm or less, 80 nm or less, 70 nm or less, 60 nm or less, or 50 nm or less. The lower limit of the average particle diameter is not particularly limited, and is usually 5 nm or more. The commercially available product of the inorganic filler having the above-mentioned average particle diameter is, for example, "YC100C", "YA050C", "YA050C-MJE", "YA010C" manufactured by Admatechs, and the electric chemical industry (stock) system. "UFP30", "Silfil NSS-3N" by TOKUYAMA, "Silfil NSS-4N", "Silfil NSS-5N". The average particle diameter of the inorganic filler can be measured by a laser diffraction or scattering method based on the Mie scattering theory. Specifically, the particle size distribution of the inorganic filler is prepared on a volume basis by a laser diffraction scattering type particle size distribution measuring apparatus, and the median diameter can be measured as an average particle diameter. For the measurement of the sample, it is preferred to use an inorganic filler which is ultrasonically dispersed in water. As the laser diffraction scattering type particle size distribution device, "LA-500" manufactured by Horiba Ltd. can be used.

Inorganic filler, the viewpoint of improving moisture resistance and dispersibility In view of the above, one or more surfaces such as an amino decane coupling agent, an epoxy decane coupling agent, a mercapto decane coupling agent, a decane coupling agent, an organic decazane compound, and a titanate coupling agent are preferable. It is preferred that the treatment agent be treated. As a commercially available product of the surface treatment agent, "KBM403" (3-glycidoxypropyltrimethoxydecane) manufactured by Shin-Etsu Chemical Co., Ltd., and "KBM803" manufactured by Shin-Etsu Chemical Co., Ltd. (3-Mercaptopropyltrimethoxydecane), "KBE903" (3-Aminopropyltriethoxydecane) manufactured by Shin-Etsu Chemical Co., Ltd., "KBM573" (N-Benzene) manufactured by Shin-Etsu Chemical Co., Ltd. "Sodium-3-aminopropyltrimethoxydecane", "SZ-31" (hexamethyldioxane) manufactured by Shin-Etsu Chemical Co., Ltd., etc.

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

The amount of carbon per unit surface area of the inorganic filler can be measured by washing the surface-treated inorganic filler with a solvent (for example, methyl ethyl ketone (MEK)). Specifically, a sufficient amount of MEK as a solvent was added to the inorganic filler which was surface-treated with a surface treatment agent, and ultrasonic cleaning was performed at 25 ° C for 5 minutes. Removed After the supernatant is dried, the amount of carbon per unit surface area of the inorganic filler can be measured using a carbon analyzer. As the carbon analyzer, "EMIA-230V" manufactured by Horiba Ltd. can be used.

The content of the inorganic filler in the first resin composition is not particularly limited as long as a resin composition layer having a desired composition gradient is obtained, but is preferably 40% by mass or less, preferably 30% by mass. In the following, it is more preferably 25% by mass or less, still more preferably 20% by mass or less, 18% by mass or less, 16% by mass or less, 14% by mass or less, 12% by mass or less, 10% by mass or less, or 8% by mass or less. The mass% or less, 4 mass% or less, or 2 mass% or less. The content of the inorganic filler in the first resin composition is not particularly limited, and may be 0% by mass.

- (d) thermoplastic resin -

The first resin composition may further contain a thermoplastic resin. Examples of the thermoplastic resin include phenoxy resin, polyvinyl acetal resin, acrylic resin, polyolefin resin, polybutadiene resin, polyimide resin, polyamidimide resin, and polyether oxime. Resin, polyphenylene ether resin and polyfluorene resin. The thermoplastic resin may be used singly or in combination of two or more.

The polystyrene-equivalent weight average molecular weight of the thermoplastic resin is preferably in the range of 8,000 to 70,000, more preferably in the range of 10,000 to 60,000, and even more preferably in the range of 20,000 to 60,000. The polystyrene-equivalent weight average molecular weight of the thermoplastic resin is measured by a gel permeation chromatography (GPC) method. Specifically, polystyrene for thermoplastic resin The weight average molecular weight is calculated as the mobile phase using LC-9A/RID-6A manufactured by Shimadzu Corporation and Shodex K-800P/K-804L/K804L manufactured by Showa Denko (manufacturer) as a column. The chloroform or the like is measured at a column temperature of 40 ° C, and can be calculated using a standard polystyrene calibration line.

Examples of the phenoxy resin include a bisphenol A skeleton, a bisphenol F skeleton, a bisphenol S skeleton, a bisphenol acetaminophen skeleton, a phenolic skeleton, a biphenyl skeleton, an anthracene skeleton, and a dicyclopentadiene skeleton. a phenoxy resin having one or more selected ones selected from the group consisting of a thiophene skeleton, a naphthalene skeleton, an onion skeleton, an adamantene skeleton, a terpene skeleton, and a trimethylcyclohexane skeleton. The terminal of the phenoxy resin may be any one of a phenolic hydroxyl group and an epoxy group. The phenoxy resin may be used alone or in combination of two or more. Specific examples of the phenoxy resin include "1256" and "4250" (all are phenoxy resins containing a bisphenol A skeleton) and "YX8100" (including a bisphenol S skeleton) manufactured by Mitsubishi Chemical Corporation. "Phenoxy resin" and "YX6954" (phenoxy resin containing bisphenol acetal phenol skeleton), "FX280" and "FX293" manufactured by Toho Chemical Co., Ltd., and "YL7553" by Mitsubishi Chemical Co., Ltd. ", YL6794", "YL7213", "YL7290" and "YL7482".

As the acrylic resin, an acrylic resin containing a functional group is preferred, and an epoxy resin containing an epoxy group is preferred, and an epoxy group-containing acrylate copolymer resin is more preferred. When an acrylic resin containing a functional group is used as the acrylic resin, the functional group equivalent is preferably from 1,000 to 50,000, more preferably from 2,500 to 30,000.

Specific examples of the acrylic resin include "SG-80H" and "SG-P3" (epoxy group-containing acrylate copolymer resin) manufactured by Nagase Chemtex Co., Ltd.

Specific examples of the polyvinyl acetal resin include electrogenerated butyraldehyde 4000-2, 5000-A, 6000-C, 6000-EP, and Sekisui Chemical Industry Co., Ltd. manufactured by the Electrochemical Industry Co., Ltd. -LEC BH series, BX series, KS series, BL series, BM series, etc.

Specific examples of the polyimine resin include "RICACOATSN 20" and "RICACOATPN 20" manufactured by Nippon Chemical and Chemical Co., Ltd. Specific examples of the polyimine resin include a linear polyimine obtained by reacting a difunctional hydroxyl-terminated polybutadiene, a diisocyanate compound, and a tetrabasic acid anhydride (Japanese Patent Co., Ltd.) JP-A-2006-37083) A modified polyimine such as a polyfluorene skeleton having a polyoxymethylene skeleton (Japanese Patent Laid-Open Publication No. 2002-12667 and Japanese Patent Laid-Open Publication No. 2000-319386).

Specific examples of the polyamidoximine resin include "VYLOMAX HR11NN" and "VYLOMAX HR16NN" manufactured by Toyobo Co., Ltd. Specific examples of the polyamidoximine resin include modified polycondensation of a polyoxonium group-containing polyamine amidoxime "KS9100" and "KS9300" manufactured by Hitachi Chemical Co., Ltd. Amidoxime.

Specific examples of the polyether oxime resin include "PES5003P" manufactured by Sumitomo Chemical Co., Ltd., and the like.

Specific examples of the polyfluorene resin include Solvay Polymers such as Advanced Polymers (P1700) and "P3500".

The content of the thermoplastic resin in the first resin composition is not particularly limited as long as a resin composition layer having a desired composition gradient is obtained, and is preferably 0.1% by mass or more, preferably 1% by mass or more. More preferably, it is 3% by mass or more, 5% by mass or more, or 7% by mass or more. The upper limit of the content of the thermoplastic resin is not particularly limited, but is preferably 50% by mass or less, preferably 40% by mass or less, and more preferably 30% by mass or less.

- (e) hardening accelerator -

The first resin composition may further contain a hardening accelerator. Examples of the curing accelerator include a phosphorus-based curing accelerator, an amine-based curing accelerator, an imidazole-based curing accelerator, and an lanthanum-based curing accelerator, and a phosphorus-based curing accelerator, an amine-based curing accelerator, and an imidazole-based accelerator. A hardening accelerator is preferred, and an amine-based hardening accelerator and an imidazole-based hardening accelerator are preferred. The hardening accelerator may be used alone or in combination of two or more.

Examples of the phosphorus-based hardening accelerator include triphenylphosphine, strontium borate compound, tetraphenylphosphonium tetraphenylborate, n-butylphosphonium tetraphenylborate, and tetrabutylphosphonate. (4-methylphenyl)triphenylphosphonium thiocyanate, tetraphenylphosphonium thiocyanate, butyltriphenylphosphonium thiocyanate, etc., with triphenylphosphine, tetrabutyl Citrate is preferred.

Examples of the amine-based curing accelerator include trialkylamines such as triethylamine and tributylamine, 4-dimethylaminopyridine and benzyldiyl. Methylamine, 2,4,6-gin(dimethylaminomethyl)phenol, 1,8-diazabicyclo(5,4,0)-undecene, etc., with 4-dimethylamino Pyridine and 1,8-diazabicyclo(5,4,0)-undecene are preferred.

Examples of the imidazole-based hardening accelerator include 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, and 2-ethyl-4-methyl group. Imidazole, 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-methyl Imidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole trimellitic acid, 1-cyanoethyl-2-phenylimidazolium trimellitic acid, 2, 4-Diamine-6-[2'-methylimidazolium-(1')]-ethyl-s-triazine, 2,4-diamine-6-[2'-undecylimidazole-(1' )]-ethyl-s-triazine, 2,4-diamine-6-[2'-ethyl-4'-methylimidazolium-(1')]-ethyl-s-triazine, 2, 4-Diamine-6-[2'-methylimidazolium-(1')]-ethyl-s-triazine isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct, 2 -Phenyl-4,5-dimethylolimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2,3-dihydro-1H-pyrrole[1,2-a]benzimidazole , 1-dodecyl-2-methyl-3-benzylimidazolium chloride, 2-methyl The imidazole compound such as imidazole or 2-phenylimidazole and the adduct of the imidazole compound and the epoxy resin are preferably 2-ethyl-4-methylimidazole or 1-benzyl-2-phenylimidazole.

Examples of the oxime-based hardening accelerator include dicyandiamide, 1-methyl hydrazine, 1-ethyl hydrazine, 1-cyclohexyl hydrazine, 1-phenyl fluorene, and 1-(o-methylphenyl).胍, dimethyl hydrazine, diphenyl hydrazine, trimethyl hydrazine, tetramethyl hydrazine, pentamethyl hydrazine, 1,5,7-triazabicyclo[4.4.0] 癸-5-ene, 7- Methyl-1,5,7-triazabicyclo[4.4.0]non-5-ene, 1-methylbiguanide, 1-ethylbiguanide, 1-n-butylbiguanide, 1-n-18 Bismuth, 1,1-dimethylbiguanide, 1,1-diethylbiguanide, 1-cyclohexylbiguanide, 1-allyl biguanide, 1-phenylbiguanide, 1-(o-methylphenyl)biguanide, etc. Preferably, dicyandiamide and 1,5,7-triazabicyclo[4.4.0]non-5-ene are preferred.

The content of the hardening accelerator in the first resin composition is not particularly limited as long as a resin composition layer having a desired composition gradient can be obtained, but the non-volatile components of the epoxy resin and the hardener are combined. When it is 100% by mass, it is preferably used in the range of 0.05% by mass to 3% by mass.

- (f) flame retardant -

The first resin composition may further contain a flame retardant. Examples of the flame retardant include an organic phosphorus-based flame retardant, an organic nitrogen-containing phosphorus compound, a nitrogen compound, a polyfluorene-based flame retardant, and a metal hydroxide. The flame retardant may be used alone or in combination of two or more. The content of the flame retardant in the first resin composition layer is not particularly limited as long as a resin composition layer having a desired composition gradient can be obtained, but it is preferably 0.5% by mass to 20% by mass, more preferably It is 1% by mass to 15% by mass, more preferably 1.5% by mass to 10% by mass.

- (g) rubber particles -

The first resin composition may further contain rubber particles. As the rubber particles, for example, it can be used without being dissolved in a resin varnish to be described later. The organic solvent used at the time is also incompatible with the above-mentioned epoxy resin, curing agent, thermoplastic resin, and the like. The rubber particles as described above are generally prepared by increasing the molecular weight of the rubber component to such an extent that it is not dissolved in an organic solvent or a resin, and is formed into a particulate form.

Examples of the rubber particles include core-shell type rubber particles, crosslinked acrylonitrile butadiene rubber particles, crosslinked styrene butadiene rubber particles, and acrylic rubber particles. The core-shell type rubber particles are rubber particles having a core layer and a shell layer, and examples thereof include a two-layer structure in which a shell layer of an outer layer is composed of a glassy polymer, and a core layer of an inner layer is composed of a rubber-like polymer. The three-layer structure in which the outer layer is composed of a glassy polymer, the intermediate layer is composed of a rubber-like polymer, and the core layer is composed of a glassy polymer. The glassy polymer layer is composed of, for example, a methyl methacrylate polymer, and the rubbery polymer layer is made of, for example, butyl acrylate polymer (butyl rubber). The rubber particles may be used alone or in combination of two or more.

The average particle diameter of the rubber particles is preferably in the range of 0.005 μm to 1 μm, preferably in the range of 0.2 μm to 0.6 μm. The average particle diameter of the rubber particles can be measured by a dynamic light scattering method. For example, the rubber particles are uniformly dispersed in a suitable organic solvent by ultrasonic waves or the like, and a particle size distribution of the rubber particles is produced on a mass basis using a high-concentration particle size analyzer (FPAR-1000; manufactured by Otsuka Electronics Co., Ltd.). The median diameter can be measured as an average particle diameter. The content of the rubber particles in the first resin composition is preferably 1% by mass to 20% by mass, more preferably 2% by mass to 10% by mass, even more preferably 2% by mass to 5% by mass.

-Other ingredients -

The first resin composition may contain other additives as necessary, and examples of the other additives include organometallic compounds such as an organic copper compound, an organic zinc compound, and an organic cobalt compound, and an organic filler and a thickener. A resin additive such as an antifoaming agent, a leveling agent, a tackifier, and a coloring agent.

<Second resin composition>

The second resin composition is used in the resin composition layer in order to form a remaining region (volume portion) other than the region in the vicinity of the surface to which the support is bonded.

The second resin composition affects the volume characteristics of the resin composition layer, and even the bulk characteristics of the insulating layer. The second resin composition contains an inorganic filler at a high content from the viewpoint of preventing the crack of the thermal expansion of the insulating layer and the conductor layer from being caused by cracks or circuit distortion caused by the thermal expansion coefficient of the obtained insulating layer.

The content of the inorganic filler in the second resin composition is preferably more than 50% by mass, more preferably 52% by mass or more, and most preferably 54% by mass or more, from the viewpoint of lowering the thermal expansion coefficient of the obtained insulating layer. More preferably, it is 56% by mass or more, and more preferably 58% by mass or more, 60% by mass or more, 62% by mass or more, 64% by mass or more, 66% by mass or more, 68% by mass or more, or 70% by mass or more. The upper limit of the content of the inorganic filler in the second resin composition, the mechanical strength of the obtained insulating layer The viewpoint is preferably less than 96% by mass, preferably 95% by mass or less, more preferably 90% by mass or less, or 85% by mass or less.

As the inorganic filler, for example, an inorganic filler described in the first resin composition may be mentioned, and among them, cerium oxide is preferred, and spherical cerium oxide is preferred. The average particle diameter of the inorganic filler contained in the second resin composition is preferably in the range of 0.01 μm to 5 μm from the viewpoint of improving the fluidity of the resin composition layer to sufficiently achieve the circuit embedding property. It is in the range of 0.05 μm to 2 μm, more preferably in the range of 0.1 μm to 1 μm, still more preferably 0.2 μm to 0.8 μm. As a commercial item of the inorganic filler which has such an average particle diameter, the "SOC2" and "SOC1" by Admatechs are mentioned, for example.

The inorganic filler contained in the second resin composition is preferably treated with a surface treatment agent. The kind of the surface treatment agent and the degree of surface treatment are as described in the paragraph of <First Resin Composition>.

Examples of the other material contained in the second resin composition include (a) a curable resin such as an epoxy resin, and (b) a hardener described in the paragraph <First Resin Composition>. . Therefore, in one embodiment, the second resin composition contains (a) an epoxy resin, (b) a hardener, and (c) an inorganic filler. Suitable examples of the respective components are as described in the paragraph <First Resin Composition>, but the second resin composition preferably contains the following (a) to (c): (a) as a ring a mixture of a liquid epoxy resin of an oxygen resin and a solid epoxy resin (liquid epoxy resin: solid epoxy resin preferably has a mass ratio of 1:0.1 to 1:5, preferably 1:0.3) ~1:4.5 of the van Preferably, it is in the range of 1:0.6 to 1:4, particularly preferably in the range of 1:0.8 to 1:4); (b) as a hardener, a phenolic hardener, a naphthol hardener, an active ester One or more selected from the group consisting of a curing agent and a cyanate-based curing agent (preferably one or more selected from the group consisting of a phenol-based curing agent, a naphthol-based curing agent, and an active ester-based curing agent); c) cerium oxide as an inorganic filler.

The content of the (a) epoxy resin in the second resin composition is not particularly limited as long as a resin composition layer having a desired composition gradient can be obtained, and is preferably 3% by mass to 50% by mass. It is preferably 5 mass% to 45% by mass, more preferably 5 mass% to 40 mass%, still more preferably 7 mass% to 35 mass%.

The amount ratio of the (a) epoxy resin to the (b) curing agent in the second resin composition can be obtained in the same manner as described in the column of <First Resin Composition>.

The second resin composition may further contain one or more selected from the group consisting of (d) a thermoplastic resin, (e) a curing accelerator, (f) a flame retardant, and (g) rubber particles. Preferred examples of the components (d) to (g) are the same as those described in the paragraph <First Resin Composition>. The content of the (d) thermoplastic resin in the second resin composition is not particularly limited as long as a resin composition layer having a desired composition gradient can be obtained, and is preferably 0.1% by mass to 20% by mass. Preferably, it is 0.5% by mass to 10% by mass. The content of the (e) hardening accelerator in the second resin composition is 0.05% by mass to 3 when the total amount of the non-volatile components of the (a) epoxy resin and the (b) curing agent is 100% by mass. The amount % is better. The content of the (f) flame retardant in the second resin composition is not particularly limited as long as a resin composition layer having a desired composition gradient can be obtained, and it is preferably 0.5% by mass to 10% by mass. Preferably, it is 1% by mass to 9% by mass, more preferably 1.5% by mass to 8% by mass. The content of the (g) rubber particles in the second resin composition is not particularly limited as long as a resin composition layer having a desired composition gradient can be obtained, and is preferably 1% by mass to 10% by mass, more preferably It is 2% by mass to 5% by mass.

The second resin composition may contain other additives as necessary, and examples of the other additives include organometallic compounds such as an organic copper compound, an organic zinc compound, and an organic cobalt compound, and an organic filler and a thickener. A resin additive such as an antifoaming agent, a leveling agent, a tackifier, and a coloring agent.

Hereinafter, the present invention will be described in detail in conjunction with the appropriate embodiments.

[Resin sheet with support]

A resin sheet with a support according to the present invention, comprising: a support body and a resin composition layer bonded to the support body and having an inorganic filler content of 50% by mass or more, the resin composition layer being on the support side In the region near the surface, the amount ratio of the inorganic filler to the resin component (the inorganic filler/resin component) has a gradient (that is, a positive gradient from a bonding surface to the support in a thickness direction or more).

In the resin composition layer contained in the resin sheet with a support of the present invention, a resin component is present on the joint surface with the support. However, the ratio of the inorganic filler is rapidly increased from a position at a certain distance from the joint surface of the support body in the thickness direction. The "thickness direction" herein means the thickness direction of the resin composition layer, and indicates a direction perpendicular to the surface of the resin composition layer. The ratio of the inorganic filler in the resin composition layer is preferably from 0.05 μm to 2 μm from the bonding surface to the support surface in the thickness direction, preferably from 0.05 μm to 1.5 μm, more preferably The distance position of 0.05 μm to 1 μm, particularly preferably at a distance of 0.05 μm to 0.5 μm, rises sharply.

Further, when proceeding in the thickness direction, the amount ratio of the inorganic filler to the resin component will have no gradient and become a phase having a uniform composition. As long as it is a resin sheet of the present invention having a resin composition layer having a rapid composition gradient in a partial region in the vicinity of the surface on the support side, strength or heat resistance is maintained because a uniform composition is maintained as a volume characteristic. It is excellent in properties and the like, and brings about an insulating layer which can exhibit excellent peel strength to the conductor layer after the roughening treatment. As will be described in detail later, the insulating layer formed by using the resin sheet with the support of the present invention has a small surface roughness after the roughening treatment, and it is confirmed that the conductor layer exhibits excellent peel strength, and the support of the present invention is attached. The resin sheet has a significant contribution to the fine wiring of the printed circuit board.

In the present invention, the gradient of the ratio of the inorganic filler to the resin component in the region near the support side surface of the resin composition layer is used: a cross section of the resin composition layer in a direction perpendicular to the surface of the support In the middle, the resin area A _d1-d2 in the region from the predetermined distance d1 (μm) of the self-supporting body and the resin composition layer to the predetermined distance d2 (μm), and the predetermined distance d2 (μm) from the above-mentioned boundary to the predetermined The ratio (kA _d1-d2 /A _d2-d3 ) between the resin areas A _d2-d3 in the region from d3 (μm). Here, d1, d2, and d3 satisfy the number of 0≦d1<d2<d3, and k is a coefficient satisfying k=|d2-d3|/|d1-d2|.

The ratio of the resin area is SEM observation of the cross section of the resin composition layer 20 in the direction perpendicular to the surface of the support 10 (Z direction in FIG. 1) as shown schematically in FIG. 1, and the self-supporting body 10 is measured. The resin area A _d1-d2 of the region 21a from the boundary of the resin composition layer 20 (the position of Z=0 in Fig. 1) is (μm) to d2 (μm), and the distance d2 from the aforementioned boundary is The resin area A _d2-d3 of the region 21b up to (dm) to d3 (μm) can be calculated from the obtained values of A _{d1 - d2} and A _{d2 - d3} . Regarding the measurement of the A _d1-d2 value and the A _d2-d3 value, the width of the measurement region (measurement distance parallel to the direction of the surface of the support) was set equally.

In addition, the "resin area" in the present invention means the area occupied by the resin component. The "resin component" of the resin area means a component from which the inorganic filler is removed among the components constituting the resin composition.

In the resin sheet with a support of the present invention, the resin composition layer is at a region near the side surface of the support, and has a gradient of the ratio of the inorganic filler to the resin component, which is kA _d1-d2 /A _{d2 The -d3} ratio varies greatly depending on the values of d1, d2, and d3.

That is, the resin sheet with a support of the present invention is characterized in that the distance between the boundary of the self-supporting body and the resin composition layer is 0 μm in the cross section of the resin composition layer in the direction perpendicular to the surface of the support body. The resin area A _0-1 of the region up to 1 μm and the resin area A _1-2 of the region from the above boundary to the range of 1 μm to 2 μm satisfy the following relationship: A _0-1 /A _1-2 >1.1. The resin sheet with the support of the present invention preferably satisfies A from the viewpoint of obtaining a volume characteristic in which the content of the inorganic filler is high and which exhibits an excellent peel strength of the conductor layer after the roughening treatment. _0-1 /A _1-2 ≧1.15, more preferably to meet A _0-1 /A _1-2 ≧1.2.

The upper limit of A _0-1 /A _1-2 is not particularly limited, but is usually 20 or less, preferably 15 or less, preferably 10 or less, more preferably 5 or less.

In this case, in the cross section of the resin composition layer in the direction perpendicular to the surface of the support, the area (resin area) / (full area) of the distance from the boundary between the support and the resin composition layer is from 0 μm to 1 μm. The ratio is preferably 0.3 or more, more preferably 0.4 or more, still more preferably 0.5 or more, still more preferably 0.6 or more, 0.7 or more, 0.8 or more, or 0.9 or more. The upper limit of the (resin area) / (full area) ratio is not particularly limited, and may be 1.

The resin sheet with the support of the present invention can be obtained from the viewpoint of obtaining a uniform composition and a high volume of the inorganic filler, and exhibiting an excellent insulating layer for the conductor layer after the roughening treatment. In the cross section of the resin composition layer in the direction perpendicular to the surface of the support, the resin area A _0-0.5 in the region from the boundary between the support and the resin composition layer from 0 μm to 0.5 μm, and the distance from the above boundary The resin area A _0.5-1 in the region from 0.5 μm to 1 μm is preferable to satisfy the relationship of A _0-0.5 /A _0.5-1 >1.1. The resin sheet with a support of the present invention preferably satisfies A _0-0.5 /A _0.5-1 ≧ 1.2, more preferably, _from the viewpoint of achieving an insulating layer having a high peel strength for the conductor layer after the roughening treatment. Satisfy A _0-0.5 /A _0.5-1 ≧1.22, further preferably satisfy A _0-0.5 /A _0.5-1 ≧1.24, especially preferably satisfy A _0-0.5 /A _0.5-1 ≧1.26, A _0-0.5 /A _0.5-1 ≧1.28, A _0-0.5 /A _0.5-1 ≧1.3, or A _0-0.5 /A _0.5-1 ≧1.32.

The upper limit of the A _0-0.5 /A _0.5-1 ratio is not particularly limited, but is usually 20 or less, preferably 15 or less, more preferably 10 or less, still more preferably 5 or less.

In this case, in the cross section of the resin composition layer in the direction perpendicular to the surface of the support, the area (resin area) / (full area) of the distance from the boundary between the support and the resin composition layer is from 0 μm to 0.5 μm. The ratio is preferably 0.5 or more, more preferably 0.6 or more, still more preferably 0.7 or more, still more preferably 0.8 or more or 0.9 or more. The upper limit of the (resin area) / (full area) ratio is not particularly limited, and may be 1.

As described above, in the resin sheet with a support of the present invention, the resin composition layer has a composition gradient only in a partial region in the vicinity of the side surface of the support, and maintains a uniform composition as a volume characteristic.

In a preferred embodiment, in the cross section of the resin composition layer in the direction perpendicular to the surface of the support, the resin sheet with the support of the present invention has a distance of 2 μm from the boundary between the support and the resin composition layer. The resin area A _2-d in the region up to d μm and the resin area A _d-0.5D in the region from the above-described boundary from _d μm to 0.5 D μm are configured to satisfy the following relationship: 0.9≦kA _2-d /A _d-0.5D ≦ 1.1 (here, k is a coefficient satisfying k=|d-0.5D|/|2-d|, d is a number satisfying 2<d<0.5D, and the thickness of the D-type resin composition layer ). This is a resin composition layer contained in the resin sheet with the support of the present invention, and has a uniform composition in a region having a distance of 2 μm or more from the side surface of the support.

In a more preferred embodiment, the resin sheet with a support of the present invention has a distance of 1.5 from the boundary between the support and the resin composition layer in the cross section of the resin composition layer perpendicular to the surface of the support. The resin area A _1.5-d in the region from μm to dμm and the resin area A _d-0.5D in the region from the above boundary from dμm to 0.5D μm are configured to satisfy the following relationship: 0.9≦kA _1.5-d / A _d-0.5D ≦ 1.1 (here, k is a coefficient satisfying k=|d-0.5D|/|1.5-d|, d is a number satisfying 1.5<d<0.5D, and a D-type resin composition layer thickness). This is a resin composition layer contained in the resin sheet with the support of the present invention, and has a uniform composition at a region of 1.5 μm or more from the side surface of the support.

In a further preferred embodiment, the resin sheet of the support according to the present invention has a distance from the boundary between the self-supporting body and the resin composition layer in a cross section of the resin composition layer in a direction perpendicular to the surface of the support. The resin area A _1-d in the region from 1 μm to d μm and the resin area A _d-0.5D in the region from the above boundary to the range of _d μm to 0.5 D μm are configured to satisfy the following relationship: 0.9≦kA _1-d /A _d-0.5D ≦ 1.1 (here, k is a coefficient satisfying k=|d-0.5D|/|1-d|, d is a number satisfying 1<d<0.5D, and D-type resin composition layer thickness of). This is a resin composition layer contained in the resin sheet with the support of the present invention, and has a uniform composition in a region having a distance of 1 μm or more from the side surface of the support.

In a particularly preferred embodiment, the resin sheet with a support of the present invention has a distance of 0.5 from the boundary between the support and the resin composition layer in the cross section of the resin composition layer perpendicular to the surface of the support. The resin area A _0.5-d in the region from μm to dμm and the resin area A _d-0.5D in the region from the above boundary from dμm to 0.5D μm are configured to satisfy the following relationship: 0.9≦kA _0.5-d / A _d-0.5D ≦ 1.1 (here, k is a coefficient satisfying k=|d-0.5D|/|0.5-d|, d is a number satisfying 0.5<d<0.5D, and a D-type resin composition layer thickness). This is a resin composition layer contained in the resin sheet with the support of the present invention, and has a uniform composition in a region having a distance of 0.5 μm or more from the side surface of the support. Further, in the resin area ratio, the denominator is not necessarily A _{d - 0.5 D} , and may be A _dD (that is, a resin area in a region from the above boundary to a range of d μm to D μm). Even when the denominator is replaced by A _d-0.5D into A _dD , since the value is corrected by the coefficient k, the range in which the resin area ratio is suitable is the same as described above.

In the resin sheet with a support of the present invention, the content of the inorganic filler in the resin composition layer is 50% by mass or more. The content of the inorganic filler in the resin composition layer is preferably 55 mass% or more, more preferably 60 mass% or more, and still more preferably 65 mass, from the viewpoint of sufficiently reducing the thermal expansion rate of the obtained insulating layer. %the above.

In the present invention, the content of each component in the resin composition layer is a value obtained by setting the total of the nonvolatile components in the resin composition layer to 100% by mass. For example, the content of the inorganic filler in the resin composition layer may be based on the content of the inorganic filler in the first resin composition and the content of the inorganic filler in the second resin composition. The amount of the first and second resin compositions used in the layer was determined by weighted average.

The ratio of the resin area A _0-1 to the resin area A _1-2 (A _0-1 /A _1-2 ) is the above-specified range of the resin sheet with the support of the present invention, and does not bring about the conductor layer. The reduction in the peel strength further increases the content of the inorganic filler in the resin composition layer. For example, the content of the inorganic filler in the resin composition layer can be increased to 66% by mass or more, 68% by mass or more, 70% by mass or more, 72% by mass or more, 74% by mass or more, 76% by mass or more, or 78% by mass. the above.

The upper limit of the content of the inorganic filler in the resin composition layer is preferably 95% by mass or less, more preferably 90% by mass or less, and still more preferably 85% by mass or less from the viewpoint of mechanical strength of the obtained insulating layer.

The details of the respective constituent components of the resin composition layer, such as the above-mentioned <first resin composition> and <second resin composition>, are as follows. In one embodiment, the resin composition layer contained in the resin sheet with a support of the present invention contains an inorganic filler, a curable resin, and a curing agent. The resin composition layer may further contain one or more additives selected from the group consisting of a thermoplastic resin, a curing accelerator, a flame retardant, and rubber particles, and may further contain an organometallic compound, an organic filler, and a thickener. Other resin additives such as antifoaming agents, leveling agents, adhesion imparting agents, and coloring agents.

The content of the other components in the resin composition layer is not particularly limited as long as the content of the inorganic filler is within the above specific range, and may be generally in the range used for forming the insulating layer of the printed circuit board. In the present invention, the first and second resin compositions described above are used to form the resin composition layer, but the volume portion of the resin composition layer is substantially composed of the second tree. Since the fat composition is formed, the ratio of the first resin composition to the entire resin composition layer is limited. Therefore, in the resin sheet with the support of the present invention, the appropriate content of the components other than the inorganic filler in the resin composition layer may be the same as the content of each component described in the above paragraph <second resin composition>. the same.

In the resin sheet with a support of the present invention, the thickness of the resin composition layer is preferably 3 μm or more, more preferably 5 μm or more, still more preferably 7 μm or more, 8 μm or more, 9 μm or more, or 10 μm or more. The upper limit of the thickness of the resin composition layer is preferably 100 μm or less, more preferably 80 μm, still more preferably 60 μm or less, 50 μm or less, 40 μm or less, 30 μm or less or 20 μm or less.

In the resin sheet with a support of the present invention, examples of the support include a film made of a plastic material, a metal foil, a release paper, etc., and a film made of a plastic material or a metal foil is preferred. .

In the case of using a film made of a plastic material as a support, examples of the plastic material include polyethylene terephthalate (hereinafter sometimes abbreviated as "PET") and polyethylene naphthalate. (hereinafter sometimes referred to as "PEN") polyester, polycarbonate (hereinafter sometimes abbreviated as "PC"), polymethyl methacrylate (PMMA), acrylic acid, cyclic polyolefin, triacetate fiber TAC, polyether sulfur (PES), polyether ketone, polyimine, and the like. Among them, polyethylene terephthalate or polyethylene naphthalate is preferred, and polyethylene terephthalate is particularly preferred.

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

The support may be subjected to a sanding treatment or a corona treatment on the surface joined to the resin composition layer.

Further, as the support, a support having a release layer having a release layer on the surface joined to the resin composition layer may be used. The release agent used for the release layer of the support to which the release layer is attached is, for example, selected from the group consisting of an alkyd resin, a polyolefin resin, a polyurethane resin, and a polyoxymethylene resin. One or more release agents. For the support having the release layer, a commercially available one, for example, a PET film having a release layer containing an alkyd-based release agent as a main component, "SK-1" and "AL-" manufactured by Lintec Co., Ltd. can be used. 5", "AL-7", etc.

The thickness of the support is not particularly limited, but is preferably in the range of 5 μm to 75 μm, and more preferably in the range of 10 μm to 60 μm. Further, in the case of using a support having a release layer, the thickness of the entire support of the release layer is preferably in the above range.

The resin sheet with a support of the present invention may further contain a protective film on a surface that is not bonded to the support of the resin composition layer (that is, a surface opposite to the support). The protective film is used to prevent adhesion or injury to dust or the like on the surface of the resin composition layer. As the material of the protective film, the same material as that described for the support can be used. The thickness of the protective film is not particularly limited and is, for example, 1 μm to 40 μm. Attachment The resin sheet of the support can be used by peeling off the protective film when manufacturing a printed circuit board.

The resin sheet with a support of the present invention can be used for an insulating layer for forming a metal foil-clad laminate (for an insulating layer of a metal foil-clad laminate), and an insulating layer for forming a printed circuit board (printing) For the insulation of the board). Among them, in the manufacture of a printed circuit board in a build-up mode, an insulating layer (for a build-up insulating layer of a printed circuit board) can be suitably used, and it can be more suitably used for forming a conductor layer by electroplating (forming a conductor by electroplating) The layer of the printed circuit board is used for the build-up insulating layer).

[Method of Manufacturing Resin Sheet with Support]

A method for producing a resin sheet with a support according to the present invention, comprising the steps of: forming a first layer having a thickness of less than 2 μm from the first resin composition and a second resin composition; The two layers are bonded to each other to form an integrated resin composition layer, and i) the inorganic filler content in the resin composition layer is 50% by mass or more, and ii) the resin composition layer from the side of the first layer The surface is bonded to the support, and iii) the resin area of the region from the boundary between the support and the resin composition layer in the range of 0 μm to 1 μm in the cross section of the resin composition layer perpendicular to the surface of the support. A _0-1 and the resin area A _1-2 in the region from the above-described boundary of 1 μm to 2 μm satisfy the following relationship: A _0-1 /A _1-2 >1.1.

The first resin composition and the second resin composition are as described above. In the present invention, the conditions of the above i) to iii) are such that the first layer formed by the first resin composition has a thickness of less than 2 μm and the second layer formed of the second resin composition is mutually The joint is provided to form an integrated resin composition layer (also referred to simply as "resin composition layer"). Regarding the conditions of the above i), the suitable range of the content of the inorganic filler in the resin composition layer is as described in the paragraph of [resin sheet with support]. The condition of the above ii) means that the phase rich in the resin component from the first resin composition is bonded to the support. The support system is as described in the paragraph [resin sheet with support]. Further, regarding the conditions of the above iii), a suitable resin area ratio (A _0-1 /A _1-2 ratio, A _0-0.5 /A _0.5-1 ratio, kA _2-d /A _d-0.5D, etc.) The conditions are as described in the column of [resin sheet with support].

The thickness of the first layer formed of the first resin composition is less than 2 μm from the viewpoint of achieving a desired resin area ratio, preferably 1.5 μm or less, preferably 1 μm or less, more preferably less than 1.0 μm. 0.8 μm or less, 0.6 μm or less, or 0.5 μm or less. The lower limit of the thickness of the first layer is not particularly limited. However, from the viewpoint of obtaining an insulating layer which exhibits excellent peel strength to the conductor layer after the roughening treatment, and the ease of production of the resin sheet with the support, it is generally possible to 0.05 μm or more, 0.1 μm or more, and the like.

The thickness of the second layer formed of the second resin composition is not particularly limited, and the thickness of the first resin layer may be determined so that the thickness of the obtained resin composition layer is within a desired range. Further, since the second layer constitutes a layer of a volume portion of the resin composition layer, it is preferable to have a sufficient thickness as compared with the first layer. In detail, the thickness of the second layer The degree is preferably 2 times or more with respect to the thickness of the first layer, preferably 4 times or more, more preferably 6 times or more, and 8 times or more, 10 times or more, 12 times or more, 14 times or more, 16 times. More preferably, more than 18 times or more than 20 times. The thickness of the second layer may be generally 2000 times or less, 1000 times or less, or 500 times or less with respect to the thickness of the first layer. In one embodiment, the thickness of the second layer is preferably 3 μm or more, more preferably 5 μm or more, still more preferably 7 μm or more, 8 μm or more, 9 μm or more, or 10 μm or more. The upper limit of the thickness of the second layer is preferably 100 μm or less, more preferably 80 μm or less, still more preferably 60 μm or less, 50 μm or less, 40 μm or less, 30 μm or less or 20 μm or less.

The method of providing the first layer and the second layer to each other is not particularly limited as long as the conditions of the above i) to iii) can be satisfied, and for example, 1) coating on the first layer a second resin composition, a method of providing a second layer after drying the coating film; 2) a method of applying a first resin composition on the second layer, and drying the coating film to form a first layer; 3) preparing another one A method in which a first layer and a second layer are laminated to each other.

In a preferred embodiment, the step of forming the integrated resin composition layer includes: (A1) a step of preparing a temporary resin sheet with a support, the temporary resin sheet containing the support, and bonding with the support a first resin layer having a thickness of less than 2 μm formed by the first resin composition; and (B1) coating a second resin composition on the first layer, and drying the coating film to form a second layer to form an integrated resin The steps of constituting the layer Hereinafter, this embodiment is also referred to as "the first embodiment").

In the step (A1), a temporary resin sheet containing a support and a support having a first layer of a thickness of less than 2 μm formed by the first resin composition bonded to the support is prepared.

For the temporary resin sheet with a support, for example, the first resin composition may be applied onto a support, and the coating film may be dried to form a first layer. Specifically, a resin varnish obtained by dissolving a first resin composition in an organic solvent can be prepared, and the resin varnish can be applied onto a support using a die coater or the like, and dried by drying the coating film.

Examples of the organic solvent include ketones such as acetone, methyl ethyl ketone and cyclohexanone; ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate, and carbene. Acetate such as alcohol acetate; carbaryl alcohol such as cellosolve and butyl carbitol; aromatic hydrocarbon such as toluene and xylene; dimethylformamide, dimethylacetamide And a guanamine-based solvent such as N-methylpyrrolidone. The organic solvent may be used alone or in combination of two or more.

The drying of the coating film can be carried out by a known drying method such as heating or hot air blowing. Although it is different in the boiling point of the organic solvent in the resin varnish, for example, when a resin varnish containing 30% by mass to 60% by mass of an organic solvent is used, it can be dried at 50 to 150 ° C for 3 minutes to 10 minutes. A first layer made of the first resin composition is formed on the support.

The temporary resin sheet with the support may be further formed on a surface that is not joined to the support of the first layer (that is, a surface opposite to the support) The step contains a protective film. The details of the protective film are as previously described. The temporary resin sheet with a support can be used by peeling off the protective film when it is used in the step (B1).

In the step (B1), the second resin composition is applied onto the first layer, and the coating film is dried to provide a second layer to form an integrated resin composition layer.

The application of the second resin composition and the drying of the coating film can be carried out by the same method as the application of the first resin composition in the step (A1) and the drying of the coating film. Further, the drying conditions in the step (B1) may be the same as the drying conditions of the coating film in the step (A1), or may be different. On the viewpoint of improving the accuracy of the thickness of the composition layer of the resin obtained from the point of view, the step (A1) the drying temperature T _A1 (℃) and the step (B1) the drying temperature T _B1 (℃), in order to meet Department of T _A1 < The relationship of T _B1 is preferred, and it is preferable to satisfy the relationship of T _A1 +10 ≦ T _B1 , and more preferably to satisfy the relationship of T _A1 +20 ≦T _B1 .

In another embodiment, the step of forming the integrated resin composition layer includes: (A2) a step of preparing a temporary resin sheet with a protective film, the temporary resin sheet containing the protective film, and bonding with the protective film a second layer formed of the second resin composition; and (B2) coating the first resin composition on the second layer, and drying the coating film to form a first layer having a thickness of less than 2 μm to form an integrated resin The step of constituting the layer (hereinafter, this embodiment is also referred to as "second embodiment").

The protective film used in the step (A2) is as described previously. The temporary resin sheet with a protective film can be produced, for example, by applying a second resin composition on a protective film, drying the coating film, and then providing a second layer. The application of the second resin composition and the drying of the coating film can be carried out in the same manner as the application of the first resin composition in the step (A1) and the drying of the coating film.

The temporary resin sheet with a protective film may further include a second protective film on a surface that is not bonded to the protective film of the second layer (that is, a surface opposite to the protective film). In this case, the temporary resin sheet with the protective film may be sent to the step (B2) after the second protective film is peeled off.

In the step (B2), the application of the first resin composition and the drying of the coating film are carried out in the same manner as the application of the first resin composition in the step (A1) and the drying of the coating film. Further, the drying conditions in the step (B2) may be the same as the drying conditions of the coating film in the step (A2), or may be different. The drying temperature T _A2 (°C) in the step ( _A2 ) and the step (B2) are from the viewpoint of improving the thickness precision of the obtained resin composition layer and the flexibility of the obtained resin composition layer. The drying temperature T _B2 (° C.) is preferably such that the relationship of T _A2 > T _B2 is satisfied, preferably the relationship of T _A2 ≧ T _B2 +10 is satisfied, and the relationship of T _A2 ≧ T _B2 + 20 is more preferably satisfied.

In the second embodiment, after the step (B2), a support is provided on a surface that is not bonded to the protective film of the integrated resin composition layer. The details of the support are as previously described.

In still another embodiment, the integration is formed The step of the resin composition layer includes: (A3a) a step of preparing a temporary resin sheet with a support, the temporary resin sheet containing the support, and a thickness of the first resin composition bonded to the support a first layer of 2 μm; (A3b) a step of preparing a temporary resin sheet with a protective film, the temporary resin sheet comprising a protective film, and a second layer formed of the second resin composition bonded to the protective film; (B3) The temporary resin sheet with the support and the temporary resin sheet with the protective film are laminated to form a step of joining the first layer and the second layer (hereinafter, this embodiment is also referred to as "third embodiment").

In the third embodiment, the step (A3a) and the step (A3b) can be carried out in the same manner as the step (A1) in the first embodiment and the step (A2) in the second embodiment.

In the step (B3), the temporary resin sheet with the support and the temporary resin sheet with the protective film are laminated to join the first layer and the second layer.

The lamination of the temporary resin sheet with the support and the temporary resin sheet with the protective film is good in workability, and it is easy to obtain an equal contact state, and the two sheets are laminated by roll bonding or press bonding. Processing is better. Among them, a vacuum lamination method in which lamination under reduced pressure is preferred. The lamination method can be batch or continuous.

For the lamination treatment, the crimping pressure is generally in the range of 1 kgf/cm ² to 11 kgf/cm ² (9.8×10 ⁴ N/m ² to 107.9×10 ⁴ N/m ² ), and the crimping temperature is 70 ° C. In the range of 120 ° C, the pressure bonding time is in the range of 5 seconds to 180 seconds, and it is preferably carried out under reduced pressure of 20 mmHg (26.7 hPa) or less.

The lamination treatment can be carried out using a commercially available vacuum laminator. For example, a vacuum press laminator manufactured by Nippon Machine Co., Ltd., a Vacuum applicator manufactured by Nichigo-Morton Co., Ltd., or the like can be used.

The first embodiment or the second embodiment described above is a step of forming an integrated resin composition layer from the viewpoint of easily obtaining a resin composition layer having a desired resin area ratio throughout the entire resin sheet. Preferably, the first embodiment described above is preferred.

[A printed circuit board]

The printed circuit board of the present invention contains an insulating layer formed using the resin sheet with the support of the present invention.

In one embodiment, the printed circuit board of the present invention is produced by using the resin sheet with a support of the present invention and comprising the following steps (I) and (II).

(I) A step of laminating a resin sheet with a support of the present invention on an inner layer substrate to bond the resin composition layer to the inner layer substrate.

(II) a step of thermally curing the resin composition layer to form an insulating layer.

In the step (I), the resin sheet with the support of the present invention is laminated on the inner layer substrate to bond the resin composition layer to the inner layer substrate.

The "inner substrate" used in step (I), mainly a substrate such as a glass epoxy substrate, a metal substrate, a polyester substrate, a polyimide substrate, a BT resin substrate, or a thermosetting polyphenylene ether substrate; or a patterned process on one or both sides of the substrate A circuit board of a conductor layer (circuit). Further, in the production of a printed circuit board, an inner layer circuit board in which an intermediate layer of an insulating layer and/or a conductor layer must be further formed is also included in the "inner substrate" referred to in the present invention.

The lamination of the resin sheet and the inner layer substrate with the support of the step (I) can be carried out by any conventionally known method to bond the resin composition layer and the inner layer substrate by roll bonding or press bonding. Pressure treatment is preferred. The conditions of the lamination treatment can be the same as those described in the third embodiment of the "resin sheet with a support". Moreover, in order to sufficiently follow the surface unevenness of the inner layer substrate (for example, the unevenness of the surface circuit of the inner layer circuit board), the resin sheet with the support is preferably laminated with an elastic material such as heat-resistant rubber.

In the step (I), the resin sheet with the support may be laminated on one side of the inner substrate, or may be laminated on both sides of the inner substrate.

After the step (I), the resin sheet laminated on the support of the inner layer substrate may be heated and pressurized to perform a smoothing treatment. The smoothing treatment is generally carried out by heating and pressurizing a resin sheet with a support by a heated metal plate or a metal roll under normal pressure (atmospheric pressure). The conditions for heating and pressurization can be the same as those of the above lamination treatment. Further, the lamination treatment and the smoothing treatment can be continuously carried out using a commercially available vacuum laminator.

The support can be between step (I) and step (II) In addition, it can also be removed after step (II).

In the step (II), the resin composition is thermally cured to form an insulating layer.

The conditions of the thermosetting are not particularly limited, and the conditions generally employed in forming the insulating layer of the printed circuit board can be used.

For example, the thermosetting condition of the resin composition layer may differ depending on the composition of the resin composition constituting the resin composition layer, but the curing temperature may be in the range of 120 ° C to 240 ° C (preferably 150 ° C to 210 ° C) The range of °C, more preferably in the range of 170 ° C to 190 ° C), the hardening time may range from 5 minutes to 90 minutes (preferably from 10 minutes to 75 minutes, more preferably from 15 minutes to 60 minutes).

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

The insulating layer formed by using the resin sheet with a support of the present invention exhibits a low thermal expansion coefficient because it maintains a high volume content of the inorganic filler. In one embodiment, the insulating layer formed using the resin sheet with the support of the present invention may have a coefficient of linear thermal expansion of 30 ppm/° C. or less, preferably 25 ppm/° C. or less, more preferably 22 ppm. /°C or less, more preferably 20 ppm/° C. or less, 19 ppm/° C. or less, 18 ppm/° C. or less, 17 ppm/° C. or less, or 16 ppm/° C. or less. Below 15 ppm/°C or below 14 ppm/°C. The lower limit of the linear thermal expansion coefficient of the insulating layer is not particularly limited, but is usually 1 ppm/° C. or more.

The linear thermal expansion coefficient of the insulating layer can be measured, for example, by a known method such as thermomechanical analysis. As a thermomechanical analyzer, the "Thermo Plus TMA8310" by Rigaku is mentioned, for example. In the present invention, the linear thermal expansion coefficient of the insulating layer is a linear thermal expansion coefficient in the plane direction of 25 ° C to 150 ° C when subjected to thermomechanical analysis by a tensile load method.

The insulating layer formed by using the resin sheet with a support of the present invention can exhibit characteristics which are expected as an insulating layer of a printed circuit board because it maintains a uniform composition as a volume characteristic.

In one embodiment, the insulating layer formed using the resin sheet with a support of the present invention has a glass transition temperature (Tg) of preferably 120 ° C or more, preferably 140 ° C or more, more preferably 150. Above °C, further more preferably 155 ° C or more or 160 ° C or more, exhibits sufficient strength. The upper limit of Tg is not particularly limited, but is generally 250 ° C or less. The Tg of the insulating layer can be measured, for example, by a known method such as thermomechanical analysis. As a thermomechanical analyzer, the "Thermo Plus TMA8310" by Rigaku is mentioned, for example.

In one embodiment, the dielectric layer formed by using the resin sheet with a support of the present invention has a dielectric loss tangent of preferably 0.05 or less, preferably 0.04 or less, more preferably 0.03 or less. More preferably, it is 0.02 or less or 0.01 or less, and heat generation, signal delay, and signal noise are reduced at a high frequency. The lower limit of the dielectric loss tangent is not particularly limited, but is generally 0.001 or more. The dielectric loss angle of the insulating layer is positive The cutting can be carried out, for example, by a known method such as a cavity resonator perturbation method. The dielectric loss tangent measuring device of the cavity resonator perturbation method is, for example, "HP8362B" manufactured by Agilent Technologies. In the present invention, the dielectric loss tangent of the insulating layer is a dielectric loss tangent measured by a cavity resonator perturbation method at a frequency of 5.8 GHz and a measurement temperature of 23 °C.

In the manufacture of the printed circuit board, the following steps may be further performed: (III) a step of opening the insulating layer, (IV) a step of roughening the insulating layer, and (V) forming a conductor layer on the surface of the insulating layer. step. These steps (III) to (V) can be carried out by various methods known to those skilled in the art in accordance with the known methods used in the manufacture of printed circuit boards. Further, in the case where the support is removed after the step (II), the support may be removed between the step (II) and the step (III), between the step (III) and the step (IV), or in the step. (IV) is implemented between step (V).

The step (III) is a step of opening a hole in the insulating layer, thereby forming a hole of a via hole, a through hole or the like in the insulating layer. For example, a drill bit, a laser (carbon dioxide laser, a YAG laser, etc.), a plasma equal to an insulating layer may be used to form a hole.

Step (IV) is a step of roughening the insulating layer. The procedures and conditions for the roughening treatment are not particularly limited, and well-known procedures and conditions generally used when forming an insulating layer of a printed circuit board can be employed. For example, the insulating layer may be roughened by sequentially performing a swelling treatment by a swelling liquid, a roughening treatment by an oxidizing agent, and a neutralization treatment by a neutralizing liquid. Reason. The swelling liquid is not particularly limited, and examples thereof include an alkaline solution and a surfactant solution, and an alkaline solution is preferred. As the alkaline solution, a sodium hydroxide solution or a potassium hydroxide solution is preferred. As a commercially available swelling liquid, Swelling Dip Securiganth P, Swelling Dip Securiganth SBU, etc. by Atotech Japan Co., Ltd., etc. are mentioned, for example. The swelling treatment by the swelling liquid is not particularly limited. For example, the insulating layer may be immersed in a swelling liquid at 30 ° C to 90 ° C for 1 minute to 20 minutes. The oxidizing agent is not particularly limited, and examples thereof include an alkaline permanganic acid solution in which potassium permanganate or sodium permanganate is dissolved in an aqueous solution of sodium hydroxide. The roughening treatment by an oxidizing agent such as an alkaline permanganic acid solution is preferably carried out by immersing the insulating layer in an oxidizing agent solution heated to 60 ° C to 80 ° C for 10 minutes to 30 minutes. Further, the concentration of the permanganate in the alkaline permanganic acid solution is preferably from 5% by mass to 10% by mass. The commercially available oxidizing agent is, for example, an alkaline permanganic acid solution such as Concentrate Compact CP or Dosing Solution Securiganth P manufactured by Atotech Japan Co., Ltd. In addition, as a neutralization liquid, an acidic aqueous solution is preferable, and a commercial product, for example, Reduction Solutions Securiganth P by Atotech Japan Co., Ltd. is mentioned. The treatment by the neutralizing solution can be carried out by immersing the treated surface roughened by the oxidizing agent solution in a neutralizing solution at 30 ° C to 80 ° C for 5 minutes to 30 minutes.

In the prior art including the above-mentioned Patent Document 1, in the roughening treatment, the inorganic filler present on the surface of the insulating layer is detached, and irregularities are formed on the surface. This unevenness is considered to exert an anchoring effect between the conductor layers, and the peel strength between the insulating layer and the conductor layer is increased. However, when the insulation layer When the content of the inorganic filler in the middle becomes high, even if there is an anchoring effect due to the unevenness, there is a case where the peeling strength between the insulating layer and the conductor layer is inevitably lowered, and the insulating layer is formed after the roughening treatment. The case where the surface roughness becomes too high.

The resin composition layer contained in the resin sheet with a support of the present invention has a rapid composition gradient in the vicinity of the support and the joint surface as described above, but the composition gradient is in the use of the support of the present invention. The insulating layer formed of the resin sheet is also maintained. Therefore, the insulating layer formed by using the resin sheet with a support of the present invention maintains a high volume content of the inorganic filler while making the ratio of the inorganic filler in the vicinity of the surface low. Thereby, in the insulating layer formed using the resin sheet with the support of the present invention, the detachment of the inorganic filler due to the roughening treatment is more difficult to occur than the insulating layer of the prior art. The insulating layer formed by using the resin sheet with the support of the present invention exhibits excellent peel strength to the conductor layer after the roughening treatment, which is presumed to be due to the balance of the content of the inorganic filler and the inorganic filler. A surface that contributes to the peel strength of the conductor layer is reproduced.

In one embodiment, the arithmetic mean roughness Ra of the surface of the insulating layer after the roughening treatment is preferably 180 nm or less, preferably 150 nm or less, more preferably 120 nm or less, still more preferably 110 nm or less. The insulating layer formed using the resin sheet with a support of the present invention exhibits excellent conductivity to the conductor layer even when Ra is 100 nm or less, 90 nm or less, 80 nm or less, 70 nm or less, 60 nm or less, or 50 nm or less. Peel strength. The lower limit of the Ra value is not particularly limited, It is preferably 0.5 nm or more, more preferably 1 nm or more.

The arithmetic mean roughness Ra of the surface of the insulating layer can be measured using a non-contact type surface roughness meter. Specific examples of the non-contact surface roughness meter include "WYKO NT3300" manufactured by Wycom Instruments.

Step (V) is a step of forming a conductor layer on the surface of the insulating layer.

The conductor material used for the conductor layer is not particularly limited. In a preferred embodiment, the conductor layer comprises one or more selected from the group consisting of gold, platinum, palladium, silver, copper, aluminum, cobalt, chromium, zinc, nickel, titanium, tungsten, iron, tin, and indium. metal. The conductor layer may be a single metal layer or an alloy layer. Examples of the alloy layer include alloys of two or more kinds of metals selected from the above groups (for example, nickel-chromium alloy, copper-nickel alloy, and copper-titanium alloy). The layer formed. Among them, a single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver or copper, or a nickel-chromium alloy is used in view of versatility, cost, and ease of pattern formation of the conductor layer. An alloy layer of copper-nickel alloy or copper-titanium alloy is preferred, preferably a single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver or copper, or an alloy layer of nickel-chromium alloy, preferably It is a single metal layer of copper.

The conductor layer may have a single layer structure, or may have a multilayer structure in which a single metal layer or an alloy layer formed of different kinds of metals or alloys is laminated. When the conductor layer has a multilayer structure, the layer in contact with the insulating layer is preferably a single metal layer of chromium, zinc or titanium or an alloy layer of nickel-chromium alloy.

The thickness of the conductor layer is determined according to the desired design of the printed circuit board, but is generally 3 μm to 35 μm, preferably 5 μm. 30 μm.

The conductor layer can be formed by electroplating. For example, the surface of the insulating layer can be plated by a conventionally known technique such as a semi-additive method or a full-addition method to form a conductor layer having a desired wiring pattern. Hereinafter, an example in which a conductor layer is formed by a semi-additive method will be described.

First, an electroplated seed layer is formed on the surface of the insulating layer by electroless plating. Next, on the formed plating seed layer, a mask pattern in which a part of the plating seed layer is exposed corresponding to the desired wiring pattern is formed. After the metal layer is formed by electrolytic plating on the exposed plating layer, the mask pattern is removed. Thereafter, an unnecessary plating plating layer is removed by etching to form a conductor layer having a desired wiring pattern.

In one embodiment, the peeling strength of the insulating layer and the conductor layer after the roughening treatment is preferably 0.5 kgf/cm or more, more preferably 0.55 kgf/cm or more, still more preferably 0.60 kgf/cm or more, and particularly preferably 0.65kgf/cm or more. On the other hand, the upper limit of the peel strength is not particularly limited, but is 1.2 kgf/cm or less and 0.9 kgf/cm or less. In the present invention, even if the surface roughness Ra of the insulating layer after the roughening treatment is small, an insulating layer which exhibits a high peel strength as described above can be formed. Therefore, the present invention contributes significantly to the fine wiring of a printed circuit board.

Further, in the present invention, the peel strength of the insulating layer and the conductor layer refers to the peel strength (90-degree peel strength) when the conductor layer is pulled and peeled off in the vertical direction (90-degree direction), and the conductor layer pair is used. The peeling strength at the time of peeling of the insulating layer in the vertical direction (90-degree direction) can be determined by a tensile tester. As a tensile testing machine, for example The "AC-50C-SL" made by TSE is listed.

[semiconductor device]

A semiconductor device can be fabricated using the above printed circuit board.

Examples of the semiconductor device include electrical products (for example, computers, mobile phones, digital cameras, and televisions) and various semiconductor devices for use in vehicles (for example, locomotives, automobiles, electric cars, ships, airplanes, etc.). .

[Examples]

Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited to the examples. In addition, in the following, "parts" and "%" represent "mass parts" and "% by mass" unless otherwise specified.

First, various measurement methods and evaluation methods will be described.

[Modulation of sample for measurement and evaluation] (1) Underlying processing of the inner layer circuit substrate

A glass cloth substrate having an inner layer circuit is formed on both sides of a copper-clad laminate (a thickness of a copper foil of 18 μm, a thickness of a substrate of 0.3 mm, and a "R5715ES" manufactured by Panasonic Electric Co., Ltd.), and an MEC ( The "CZ8100" system was etched by 1 μm to roughen the copper surface.

(2) Lamination of resin sheets with support

The resin sheets with the support produced in the examples and the comparative examples were layered on both sides of the inner layer circuit board using a batch type vacuum pressure laminator ("MVLP-500" manufactured by Seiki Co., Ltd.). The pressure treatment is performed to bond the resin composition layer to the inner layer circuit substrate. The lamination treatment was carried out by pressure-reducing the pressure at a pressure of 13 hPa for 30 seconds at 100 ° C and a pressure of 0.74 MPa for 30 seconds.

(3) Thermal hardening of the resin composition layer

After laminating the resin sheet with the support, the resin composition layer was thermally cured at 170 ° C for 30 minutes to form an insulating layer. Next, the support is peeled off.

(4) roughening treatment

An inner layer circuit board having an insulating layer on both sides is immersed in a swelling solution (Stoing Dip Securiganth P, Atotech Japan Co., Ltd., sodium hydroxide aqueous solution containing diethylene glycol monobutyl ether) at 60 ° C. In the minute, the mixture was immersed in an oxidizing agent (Concentrate Compact CP, manufactured by Atotech Japan Co., Ltd., an aqueous solution having a potassium permanganate concentration of about 6 mass% and a sodium hydroxide concentration of about 4 mass%) at 80 ° C for 20 minutes, and finally at 40 ° C. The mixture was immersed in a neutralizing liquid (Reduction Solutions Securiganth P manufactured by Atotech Japan Co., Ltd., aqueous hydroxylamine sulfate solution) for 5 minutes. Thereafter, it was dried at 80 ° C for 30 minutes. The resulting substrate This is called "evaluation substrate A".

(5) Formation of conductor layer

According to the semi-additive method, a conductor layer is formed on the surface of the insulating layer.

That is, the evaluation substrate A was immersed in a solution for electroless plating containing PdCl ₂ at 40 ° C for 5 minutes, and then immersed in an electroless copper plating solution at 25 ° C for 20 minutes to form an electroplated seed layer on the surface of the insulating layer. After heating at 150 ° C for 30 minutes and annealing treatment, an etching resist is provided on the plating seed layer, and the plating seed layer is patterned by etching. Next, copper sulfate electroplating was performed to form a conductor layer having a thickness of 30 μm, and then annealed at 190 ° C for 60 minutes. The obtained substrate is referred to as "evaluation substrate B".

<Measurement of resin area ratio>

With respect to the resin sheets with the support prepared in the examples and the comparative examples, the cross section of the resin composition layer in the direction perpendicular to the surface of the support was observed by SEM, and the distance between the boundary of the self-support and the resin composition layer was measured. The resin area A _d1-d2 in the region from d1 (μm) to d2 (μm) and the resin area A _d2-d3 in the region from the above boundary from d2 (μm) to d3 (μm). Then, the resin area ratio (kA _{d1 - d2} / A _{d2 - d3} ) was calculated from the obtained values of A _{d1 - d2} and A _{d2 - d3} .

Specifically, the resin area is stored as an image, and the image analysis software is used to set the resin portion to black, and the inorganic filler portion other than the resin is white, and the black and white binarization is performed. The number of bits of the black portion is taken as the area of the resin portion. Also, the resin composition layer The SEM observation of the cross section was carried out using a focused ion beam/scanning ion microscope ("SMI3050SE" manufactured by SII‧Nippon Technology Co., Ltd.), and the width of the measurement region was 7.5 μm.

<Measurement of arithmetic mean roughness (Ra value)>

The arithmetic mean roughness (Ra value) of the surface of the insulating layer after the roughening treatment was measured in accordance with the procedure described below. In the evaluation substrate A, a non-contact surface roughness meter ("WYKO NT3300" manufactured by Veeco Instruments) was used, and the measurement range was 121 μm × 92 μm by a 50-fold lens in a VSI connection mode, and the obtained value was obtained. Ra value. For each of the evaluation substrates, an average value of 10 points was randomly selected.

<Measurement of peel strength>

The peeling strength between the insulating layer and the conductor layer was measured in accordance with the procedure described below. The portion of the conductor layer of the evaluation substrate B having a width of 10 mm and a length of 100 mm was cut into the slit, and the end was peeled off and grasped by a jig, and the load at the time of peeling off 35 mm in the vertical direction at a speed of 50 mm/min was measured at room temperature ( Kgf/cm). For the measurement, a tensile tester (Autocom type tester "AC-50C-SL" manufactured by TSE) was used.

<Measurement of Thermal Expansion Coefficient and Glass Transfer Temperature (Tg)>

The resin sheet with the support prepared in the examples and the comparative examples was heated at 190 ° C for 90 minutes to thermally harden the resin composition layer. Next, the support was peeled off to obtain a sheet-like cured product. The resulting flaky cured product, A test piece having a width of about 5 mm and a length of about 15 mm was cut, and a thermomechanical analysis was carried out by a tensile load method using a thermomechanical analyzer ("Thermo Plus TMA8310" manufactured by Rigaku Co., Ltd.). Specifically, after the test piece was attached to the above-described thermomechanical analyzer, the measurement was continuously performed twice under the measurement conditions of a load of 1 g and a temperature increase rate of 5 ° C/min. In the second measurement, the average linear thermal expansion coefficient (ppm/° C.) and the glass transition temperature (Tg) in the range from 25° C. to 150° C. were calculated.

<Measurement and evaluation of dielectric loss tangent>

The resin sheet with the support prepared in the examples and the comparative examples was heated at 190 ° C for 90 minutes to thermally harden the resin composition layer. Next, the support was peeled off to obtain a sheet-like cured product. The obtained sheet-like cured product was cut into a test piece having a width of 2 mm and a length of 80 mm, and a cavity resonator perturbation method dielectric constant measuring device ("HP8362B" manufactured by Agilent Technologies Co., Ltd.) was used for measurement. The dielectric loss tangent was measured under the conditions of a frequency of 5.8 GHz and a measurement temperature of 23 °C. The measurement was performed on two test pieces, and the average value was calculated.

The varnishes of the resin compositions 1 to 6 used in the examples and the comparative examples were prepared in accordance with the following.

<Preparation Example 1> Modification of varnish of resin composition 1

Bisphenol type epoxy resin (ZX1059) made by Nippon Steel & Sumitomo Chemical Co., Ltd., 1:1 mixture of bisphenol A type and bisphenol F type, epoxy equivalent of about 169) 10 parts, biphenyl type ring Oxygen resin (Nippon Chemical Co., Ltd.) "NC3000H", an epoxy equivalent of about 290), 30 parts, and dissolved in 700 parts of methyl ethyl ketone (MEK) by heating while stirring. After cooling to room temperature, a phenol novolak-based curing agent containing a triazine skeleton ("LA-7054" manufactured by DIC Co., Ltd., a 60% by mass MEK solution having a nonvolatile content, and a phenolic hydroxyl equivalent of 124) was added in an amount of 20 parts. 1 part of a hardening accelerator (4-dimethylaminopyridine (DMAP), a solid content of 10% by mass of MEK solution), a polyvinyl butyral resin solution ("KS-1" manufactured by Sekisui Chemical Co., Ltd.), glass transition temperature A varnish of the resin composition 1 was prepared by adding 20 parts of a mixed solution of a non-volatile component of 15% by mass of ethanol:toluene having a mass ratio of 1:1 at 105 °C.

<Preparation Example 2> Modulation of varnish of Resin Composition 2

Bisphenol type epoxy resin (ZX1059, manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd., epoxy equivalent: 169) 10 parts, biphenyl type epoxy resin ("Nakamoto" ("NC3000H", epoxy resin) An equivalent of about 290) 40 parts, 30 parts of a phenoxy resin ("7555BH30" manufactured by Mitsubishi Chemical Corporation, and a MEK solution of 30% by mass of a solid component) was heated and dissolved in 900 parts of MEK with stirring. 60 parts of an active ester-based curing agent ("HPC8000-65T" manufactured by DIC Co., Ltd., a toluene solution having a reactive base equivalent of about 223 and a nonvolatile content of 65 mass%), and a phenol novolak-based hardener containing a triazine skeleton. (DIC-7) "LA-7054", 60% by mass of MEK solution with nonvolatile content, phenolic hydroxyl equivalent 124) 15 parts, N-phenyl-3-aminopropyltrimethoxydecane (Shin-Etsu Chemical Industry) (Stock) "KBM-573") 2 parts, hardening accelerator (DMAP, solid content 3 parts of a 10% by mass MEK solution) and 200 parts of cyclohexanone were prepared to prepare a varnish of the resin composition 2.

<Preparation Example 3> Modulation of varnish of resin composition 3

In addition to the polyvinyl butyral resin solution ("KS-1" manufactured by Sekisui Chemical Co., Ltd., glass transfer temperature 105 ° C, non-volatile content 15% by mass ethanol: toluene mass ratio 1:1 mixed solution) 20 parts The resin composition 3 was prepared in the same manner as in Preparation Example 1 except that 50 parts of an epoxy group-containing acrylate copolymer (18% by mass of a non-volatile component of "SG-80H" manufactured by Nagase Chemtex Co., Ltd.) was used. Varnish.

<Preparation Example 4> Modulation of varnish of resin composition 4

In addition to replacing the active ester-based hardener ("HPC8000-65T" manufactured by DIC Co., Ltd., a toluene solution having a reactive base equivalent of about 223 and a nonvolatile content of 65 mass%), 60 parts were changed to an active ester-based hardener (DIC). ) "HPC8000-65T", a toluene solution having a reactive base equivalent of about 223 and a nonvolatile content of 65 mass%) 30 parts and a nanometer cerium oxide filling slurry ("YA050C-MJE" manufactured by Admatechs, average particle diameter) A varnish of the resin composition 4 was prepared in the same manner as in Preparation Example 2 except that 40 parts of the surface was treated with 50 mg of methacrylonitrile decane and a mass fraction of 50% by mass of MEK slurry.

<Preparation Example 5> Modulation of varnish of resin composition 5

Bisphenol-based epoxy resin (ZX1059, manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd., epoxy equivalent: 169), 15 parts, biphenyl type epoxy resin (Nippon Chemical Co., Ltd. "NC3000H", epoxy Equivalent to 290) 30 parts, 5 parts of a naphthalene type tetrafunctional epoxy resin (epoxy equivalent 162, DIC ("HP-4700") made by heating, dissolved in MEK 20 parts and 10 parts of cyclohexanone while stirring. In a mixed solvent. After cooling to room temperature, a phenol novolak-based curing agent containing a triazine skeleton (a phenolic hydroxyl equivalent of about 124, a "LA-7054" manufactured by DIC Co., Ltd., and a 60% by mass MEK solution having a nonvolatile content) 30 was mixed. One part, a curing accelerator (DMAP, a solid content of 10% by mass in MEK solution), and a spherical cerium oxide (manufactured by Shin-Etsu Chemical Co., Ltd. "KBM573") SOC2", an average particle diameter of 0.5 μm, a carbon amount per unit surface area of 0.39 mg/m ² ) 125 parts, a polyvinyl butyral resin solution ("KS-1" manufactured by Sekisui Chemical Industry Co., Ltd., glass transition temperature: 105 ° C) 10 parts of a non-volatile component: 15% by mass of ethanol: a mixed solution of a toluene mass ratio of 1:1) was uniformly dispersed by a high-speed rotary mixer to prepare a varnish of the resin composition 5.

<Preparation Example 6> Modification of varnish of resin composition 6

Bisphenol-based epoxy resin (ZX1059, manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd., epoxy equivalent: 169) 20 parts, biphenyl type epoxy resin ("Nakamoto"("NC3000H", epoxy resin) An equivalent of about 290) 40 parts, 15 parts of a phenoxy resin ("755755BH30" manufactured by Mitsubishi Chemical Corporation, and a MEK solution of 30% by mass of a solid component) was heated and dissolved in 20 parts of a solvent oil while stirring. 60 parts of an active ester-based curing agent ("HPC8000-65T" manufactured by DIC Co., Ltd., a toluene solution having a reactive base equivalent of about 223 and a nonvolatile content of 65 mass%), and a phenol novolak-based hardener containing a triazine skeleton. (DIC-7) "ME-7 solution of non-volatile content of "LA-7054", a phenolic hydroxyl equivalent of 124), 15 parts of a curing accelerator (DMAP, a solid content of 10% by mass of MEK solution), and an amino group. A cerium-based coupling agent ("KBM573" manufactured by Shin-Etsu Chemical Co., Ltd.) has a spherical cerium oxide ("SOC1" manufactured by Admatechs, having an average particle diameter of 0.24 μm and a carbon content per unit surface area of 0.36 mg/m ² ). 375 parts were uniformly dispersed by a high-speed rotary mixer to prepare a varnish of the resin composition 6.

<Example 1> Production of Resin Sheet 1 with Support

A PET film ("AL5" manufactured by LINTEC Co., Ltd.) having a thickness of 38 μm was prepared as a support. The varnish of the resin composition 1 was uniformly applied to the support by a die coater, and the coated film was dried at 80 ° C for 3 minutes to form a first layer having a thickness of 0.5 μm. Then, the varnish of the resin composition 5 was uniformly applied to the first layer by a die coater so that the total thickness of the resin composition after drying became 10 μm, and the coated film was dried at 80 to 120 ° C (average 100 ° C). 4 minutes, a resin sheet 1 with a support was produced.

<Example 2> Production of Resin Sheet 2 with Support

A resin sheet 2 with a support was produced in the same manner as in Example 1 except that the varnish of the resin composition 1 was used instead of the varnish of the resin composition 2.

<Example 3> Production of Resin Sheet 3 with Support

A resin sheet 3 with a support was produced in the same manner as in Example 1 except that the varnish of the resin composition 5 was used instead of the varnish of the resin composition 6.

<Example 4> Production of Resin Sheet 4 with Support

In place of the varnish of the resin composition 1, the varnish of the resin composition 2 was used to form the first layer, and the varnish of the resin composition 5 was replaced. A resin sheet 4 with a support was produced in the same manner as in Example 1 except that the varnish of the resin composition 6 was used to form the second layer.

<Example 5> Production of Resin Sheet 5 with Support

In place of the varnish of the resin composition 1, the varnish of the resin composition 3 is used to form the first layer, and the varnish of the resin composition 5 is replaced, and the varnish of the resin composition 6 is used to form the second layer. In the same manner as in Example 1, a resin sheet 5 with a support was produced.

<Example 6> Production of Resin Sheet 6 with Support

A resin sheet 6 with a support is obtained in the same manner as in the above-mentioned "(Production of Resin Sheet 1 with Support)", except that the resin varnish 1 is replaced with the resin varnish 4, and the resin varnish 5 is replaced with the resin varnish 6.

<Comparative Example 1> Production of Resin Sheet 7 with Support

A PET film ("AL5" manufactured by LINTEC Co., Ltd.) having a thickness of 38 μm was prepared as a support. Then, the varnish of the resin composition 5 was uniformly applied to the support by a die coater so that the thickness of the resin composition layer after drying became 10 μm, and the coated film was dried at 80 to 120 ° C (average 100 ° C). 4 minutes, a resin sheet 7 with a support was produced.

<Comparative Example 2> Production of Resin Sheet 8 with Support

In addition to replacing the varnish of the resin composition 5, the use of the resin composition is changed. A resin sheet 8 with a support was produced in the same manner as in Comparative Example 1, except for the varnish of 6.

The evaluation results are shown in Table 2.

Claims (11)

A resin sheet with a support body, comprising: a support body, and a resin composition layer bonded to the support body and having an inorganic filler content of 50% by mass or more, characterized by being perpendicular to a surface of the support body In the cross section of the resin composition layer, the resin area A _0-1 in the region from the boundary between the support and the resin composition layer from 0 μm to 1 μm, and the resin in the region from the above boundary to the range of from 1 μm to 2 μm The area A _1-2 satisfies the following relationship: A _0-1 /A _1-2 >1.1. A resin sheet with a support body, comprising: a support body, and a resin composition layer bonded to the support body and having an inorganic filler content of 50% by mass or more, characterized by being perpendicular to a surface of the support body In the cross section of the resin composition layer, the resin area A _0-0.5 in the region from the boundary between the support and the resin composition layer from 0 μm to 0.5 μm, and the distance from the above boundary to the range from 0.5 μm to 1 μm The resin area A _0.5-1 satisfies the following relationship: A _0-0.5 /A _0.5-1 >1.1. The resin sheet with a support according to claim 1, wherein a distance from the boundary between the self-supporting body and the resin composition layer is 0.5 μm in a cross section of the resin composition layer in a direction perpendicular to the surface of the support body. The resin area A _0.5-d in the region up to d μm and the resin area A _d-0.5D in the region from the above-described boundary from _d μm to 0.5 D μm satisfy the following relationship: 0.9≦kA _0.5-d /A _d-0.5D ≦ 1.1 (here, k is a coefficient satisfying k=|d-0.5D|/|0.5-d|, and d is a number satisfying 0.5<d<0.5D, and a thickness of the D-based resin composition layer). A method for producing a resin sheet with a support, characterized by comprising the steps of: forming a first layer having a thickness of less than 2 μm from the first resin composition and a second layer formed of the second resin composition The resin composition layer is formed by being joined to each other to form an integrated resin composition layer, and the content of the inorganic filler in the resin composition layer is 50% by mass or more, and the surface of the resin composition layer from the side of the first layer is bonded to the support. In the cross section of the resin composition layer in the direction perpendicular to the surface of the support, the resin area A _0-1 in the region from the boundary between the support and the resin composition layer from 0 μm to 1 μm, and the distance from the above boundary are The resin area A _1-2 of the region from 1 μm to 2 μm satisfies the following relationship: A _0-1 /A _1-2 >1.1. The method of claim 4, wherein the step of forming the resin composition layer comprises: (A1) a step of preparing a temporary resin sheet with a support, the temporary resin sheet containing a support, and bonding with the support a first layer having a thickness of less than 2 μm formed by the first resin composition; and (B1) applying a second resin composition on the first layer, and drying the coating film to form a second layer to form an integral body The step of forming a resin composition layer. The method of claim 4, wherein the first layer has a thickness of less than 1 μm. The method according to claim 4, wherein the first resin composition contains an inorganic filler having an average particle diameter of 500 nm or less. The method according to claim 4, wherein the inorganic filler content in the first resin composition is 40% by mass or less. The method according to any one of claims 4 to 8, wherein the content of the inorganic filler in the second resin composition is more than 50% by mass. A printed circuit board comprising: an insulating layer formed using a resin sheet with a support as described in any one of claims 1 to 3. A semiconductor device comprising: the printed circuit board of claim 10.