JP6398824B2 - Resin sheet - Google Patents

Description

  The present invention relates to a resin sheet. Furthermore, the present invention relates to a printed wiring board and a semiconductor device.

  As a method of manufacturing a printed wiring board, a build-up method in which circuit-formed conductor layers and insulating layers are alternately stacked is widely used, and it is known that an insulating layer is formed by laminating a resin sheet. ing.

  For example, Patent Document 1 discloses a cured prepreg layer obtained by impregnating a sheet-like fiber base material with a thermosetting resin composition and curing, and a thermosetting resin composition layer provided on both sides of the cured prepreg layer. The technique which forms an insulating layer using the resin sheet which has these is described.

JP 2009-231240 A

  In recent years, multilayer printed wiring boards tend to be lighter, thinner and shorter, and there is a demand for thinner resin sheets.

  The present inventors proceeded with studies using the cured prepreg layer as described above. However, since a sheet-like fiber substrate is used, there is a limit to thinning, and a thermosetting resin composition is applied to the sheet-like fiber substrate. It was found that a process for impregnation was required and cost was high. It has also been found that when an insulating layer is formed using a thin resin sheet, the printed wiring board may be warped in the component mounting process.

  Therefore, the problem to be solved by the present invention is to provide a resin sheet that provides an insulating layer that can suppress warpage in a component mounting process even when it is a thin film when applied to a printed wiring board.

  As a result of intensive studies on the above problems, the present inventors have found that the above problems can be solved by using a resin sheet having the following specific configuration, and have completed the present invention.

That is, the present invention includes the following contents.
[1] A resin sheet having a support and an adhesive layer,
The adhesive layer includes a first resin composition layer provided on the support,
An intermediate layer provided on the first resin composition layer;
A second resin composition layer provided on the intermediate layer,
The content of the inorganic filler in the intermediate layer is a resin sheet that is 80% by mass or more when the total of non-volatile components in the intermediate layer is 100% by mass.
[2] The resin sheet according to [1], wherein the intermediate layer has a thickness of 1 to 20 μm.
[3] The resin sheet according to [1] or [2], wherein the intermediate layer has a thickness of 1 to 15 μm.
[4] The resin sheet according to any one of [1] to [3], wherein the thickness of the intermediate layer is 5% or more of the total thickness of the adhesive layer.
[5] The resin sheet according to any one of [1] to [4], wherein the thickness of the intermediate layer is 20% or more of the total thickness of the adhesive layer.
[6] The resin sheet according to any one of [1] to [5], wherein the inorganic filler is silica or glass fiber.
[7] The resin sheet according to any one of [1] to [6], wherein the inorganic filler is colloidal silica, spherical silica, or glass fiber.
[8] The resin sheet according to any one of [1] to [7], wherein the inorganic filler is colloidal silica, spherical silica having an average particle diameter of 10 μm or less, or glass fiber having an average filament diameter of 10 μm or less.
[9] The content (mass%) of the inorganic filler in the first resin composition layer is A, the content (mass%) of the inorganic filler in the intermediate layer is B, and the second resin composition layer. The resin sheet according to any one of [1] to [8], wherein A, B, and C satisfy the relationship of A <C <B, where C is the content (% by mass) of the inorganic filler in the resin .
[10] The resin sheet according to any one of [1] to [9], wherein the intermediate layer includes a phenoxy resin.
[11] The resin sheet according to any one of [1] to [10], wherein the thickness of the first resin composition layer is 0.3 to 10 μm.
[12] The resin sheet according to any one of [1] to [11], wherein the first resin composition layer is a resin composition layer for plating formation.
[13] The resin sheet according to any one of [1] to [12], wherein the thickness of the second resin composition layer is 3 to 200 μm.
[14] The resin sheet according to any one of [1] to [13], wherein the thickness of the second resin composition layer is 3 to 40 μm.
[15] The second resin composition layer contains 80% by mass or less of an inorganic filler having an average particle size of 1 μm or less, assuming that the total amount of nonvolatile components in the second resin composition layer is 100% by mass. The resin sheet according to any one of [1] to [14].
[16] The resin sheet according to any one of [1] to [15], wherein the minimum melt viscosity of the second resin composition layer is 10,000 poise or less.
[17] The resin sheet according to any one of [1] to [16], wherein the second resin composition layer is a resin composition layer for circuit embedding.
[18] The resin sheet according to any one of [1] to [17], wherein the cured product of the adhesive layer has an average linear thermal expansion coefficient of 150 to 240 ° C of 40 ppm / ° C or less.
[19] The average linear thermal expansion coefficient of 30 to 150 ° C. of the cured product of the adhesive layer is 20 ppm / ° C. or less, and the average linear thermal expansion coefficient of 150 to 240 ° C. is 40 ppm / ° C. or less. 18].
[20] A printed wiring board including an insulating layer formed using the resin sheet according to any one of [1] to [19].
[21] The printed wiring board according to [20], wherein a warpage amount in a component mounting process is 30 μm or less.
[22] A semiconductor device including the printed wiring board according to [21].

  ADVANTAGE OF THE INVENTION According to this invention, when applied to a printed wiring board, even if it was a thin film, it came to be able to provide the resin sheet which brings about the insulating layer which can suppress the curvature in the mounting process of components.

  Hereinafter, the resin sheet, printed wiring board, and semiconductor device of the present invention will be described in detail.

[Resin sheet]
The resin sheet of the present invention has a support and an adhesive layer, and the adhesive layer is provided on the first resin composition layer provided on the support and on the first resin composition layer. An intermediate layer and a second resin composition layer provided on the intermediate layer, and the content of the inorganic filler in the intermediate layer is 100% by mass of the non-volatile components in the intermediate layer. , 80% by mass or more.

  The resin sheet of the present invention has a support and an adhesive layer. Hereinafter, each layer which comprises the resin sheet of this invention is demonstrated in detail.

<Support>
The resin sheet of the present invention has a support. Examples of the support in the present invention include a film made of a plastic material, a metal foil, and a release paper, and a film made of a plastic material and a metal foil are preferable.

  When a film made of a plastic material is used as the support, examples of the plastic material include polyethylene terephthalate (hereinafter sometimes abbreviated as “PET”) and polyethylene naphthalate (hereinafter abbreviated as “PEN”). .) Polyester, polycarbonate (hereinafter sometimes abbreviated as “PC”), polymethyl methacrylate (PMMA) and other acrylics, cyclic polyolefin, triacetyl cellulose (TAC), polyether sulfide (PES), polyether Examples include ketones and polyimides. Among these, polyethylene terephthalate and polyethylene naphthalate are preferable, and inexpensive polyethylene terephthalate is particularly preferable.

  When using metal foil as a support body, as metal foil, copper foil, aluminum foil, etc. are mentioned, for example, Copper foil is preferable. As the copper foil, a foil made of a single metal of copper may be used, and a foil made of an alloy of copper and another metal (for example, tin, chromium, silver, magnesium, nickel, zirconium, silicon, titanium, etc.). It may be used.

  The support may be subjected to mat treatment or corona treatment on the surface to be bonded to the adhesive layer (specifically, the first resin composition layer).

  Further, as the support, a support with a release layer having a release layer on the surface to be bonded to the adhesive layer may be used. Examples of the release agent used for the release layer of the support with a release layer include one or more release agents selected from the group consisting of alkyd resins, polyolefin resins, urethane resins, and silicone resins. . As the support with a release layer, a commercially available product may be used. For example, “SK-1” manufactured by Lintec Corporation, which is a PET film having a release layer mainly composed of an alkyd resin release agent. , “AL-5”, “AL-7”, “Lumirror T6AM” manufactured by Toray Industries, Inc., and the like.

  Although it does not specifically limit as thickness of a support body, The range of 5 micrometers-75 micrometers is preferable, and the range of 10 micrometers-60 micrometers is more preferable. In addition, when using a support body with a release layer, it is preferable that the thickness of the whole support body with a release layer is the said range.

<Adhesive layer>
The adhesive layer includes a first resin composition layer provided on the support, an intermediate layer provided on the first resin composition layer, and a second resin composition provided on the intermediate layer. And a physical layer.

<< first resin composition layer >>
The first resin composition layer is bonded to the support, and when the printed wiring board is manufactured, a region in the vicinity of the surface of the insulating layer on which the conductor layer is provided is formed. The resin composition used for forming the first resin composition layer (hereinafter, also referred to as “first resin composition”) is not particularly limited, and the cured product has sufficient hardness and insulation. If it is. As such a resin composition, the composition containing curable resin and its hardening | curing agent is mentioned, for example. As curable resin, the conventionally well-known curable resin used when forming the insulating layer of a printed wiring board can be used, and an epoxy resin is especially preferable. Accordingly, in one embodiment, the first resin composition includes (a) an epoxy resin and (b) a curing agent. If necessary, the first resin composition may further contain (c) an inorganic filler, (d) a thermoplastic resin, (e) a curing accelerator, (f) a flame retardant, and (g) an organic filler. An agent may be included.

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

-(A) Epoxy resin-
Examples of the epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bisphenol AF type epoxy resin, dicyclopentadiene type epoxy resin, trisphenol type epoxy resin, naphthol novolak type epoxy resin, Phenol novolac type epoxy resin, tert-butyl-catechol type epoxy resin, naphthalene type epoxy resin, naphthol type epoxy resin, anthracene type epoxy resin, glycidyl amine type epoxy resin, glycidyl ester type epoxy resin, cresol novolac type epoxy resin, biphenyl type Epoxy resin, linear aliphatic epoxy resin, epoxy resin having butadiene structure, alicyclic epoxy resin, heterocyclic epoxy resin, spiro ring-containing ester Carboxymethyl resins, cyclohexanedimethanol type epoxy resins, naphthylene ether type epoxy resins and trimethylol type epoxy resins. An epoxy resin may be used individually by 1 type, or may use 2 or more types together.

  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 is preferably an epoxy resin having two or more epoxy groups in one molecule. Among them, it has two or more epoxy groups in one molecule, and has a liquid epoxy resin (hereinafter referred to as “liquid epoxy resin”) at a temperature of 20 ° C. and three or more epoxy groups in one molecule, It is preferable to contain a solid epoxy resin (hereinafter referred to as “solid epoxy resin”) at a temperature of 20 ° C. By using a liquid epoxy resin and a solid epoxy resin in combination as an epoxy resin, a resin composition having excellent flexibility can be obtained. Moreover, the breaking strength of the cured product of the resin composition is also improved.

  As the liquid epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AF type epoxy resin, phenol novolac type epoxy resin, and naphthalene type epoxy resin are preferable, bisphenol A type epoxy resin, bisphenol F type epoxy resin, Bisphenol AF type epoxy resin and naphthalene type epoxy resin are more preferable. Specific examples of the liquid epoxy resin include “HP4032”, “HP4032D”, “HP4032SS” (naphthalene type epoxy resin) manufactured by DIC Corporation, and “jER828EL” (bisphenol A type epoxy resin) manufactured by Mitsubishi Chemical Corporation. "JER807" (bisphenol F type epoxy resin), "YL7223", "YL7723", "YL7760" (bisphenol AF type epoxy resin), "jER152" (phenol novolac type epoxy resin), manufactured by Nippon Steel & Sumikin Chemical Co., Ltd. “ZX1059” (mixed product of bisphenol A type epoxy resin and bisphenol F type epoxy resin), “ZX1658” (cyclohexanedimethanol type epoxy resin), “EP-4088L” (dicyclopentadienedimethanol type) manufactured by ADEKA Corporation D Carboxymethyl resins), manufactured by Nagase ChemteX Corporation of "EX-721" (glycidyl ester type epoxy resins) and the like. These may be used individually by 1 type, or may use 2 or more types together.

  Solid epoxy resins include naphthalene type tetrafunctional epoxy resin, cresol novolac type epoxy resin, dicyclopentadiene type epoxy resin, trisphenol type epoxy resin, naphthol novolac type epoxy resin, biphenyl type epoxy resin, or naphthylene ether type epoxy. Resin is preferable, naphthalene type tetrafunctional epoxy resin, biphenyl type epoxy resin, or naphthylene ether type epoxy resin is more preferable, and naphthalene type tetrafunctional epoxy resin and biphenyl type epoxy resin are more preferable. Specific examples of the solid epoxy resin include “HP-4700”, “HP-4710” (naphthalene type tetrafunctional epoxy resin), “N-690” (cresol novolac type epoxy resin) manufactured by DIC Corporation, “ N-695 ”(cresol novolac type epoxy resin),“ HP-7200 ”(dicyclopentadiene type epoxy resin),“ EXA7311 ”,“ EXA7311-G3 ”,“ EXA7311-G4 ”,“ EXA7311-G4S ”,“ HP6000 ” ”(Naphthylene ether type epoxy resin),“ EPPN-502H ”(trisphenol epoxy resin) manufactured by Nippon Kayaku Co., Ltd.,“ NC7000L ”(naphthol novolac epoxy resin),“ NC3000H ”,“ NC3000 ”,“ NC3000L ” ”,“ NC3100 ”(biphenyl type XES resin), “ESN475V” (naphthol novolac type epoxy resin) manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., “ESN485V” (naphthol novolac type epoxy resin), “YX4000H”, “YL6121” (biphenyl) manufactured by Mitsubishi Chemical Corporation Type epoxy resin), "YX4000HK" (bixylenol type epoxy resin), "PG-100", "CG-500" manufactured by Osaka Gas Chemical Co., Ltd., "YL7800" (fluorene type epoxy manufactured by Mitsubishi Chemical Corporation) Resin) and the like.

  When the liquid epoxy resin and the solid epoxy resin are used in combination as the epoxy resin, the quantitative ratio thereof (liquid epoxy resin: solid epoxy resin) is in the range of 1: 0.1 to 1: 8 in terms of mass ratio. The range of 1: 0.3 to 1: 7 is more preferable, and the range of 1: 0.6 to 1: 6 is more preferable.

  The content of the epoxy resin in the first resin composition is preferably 5% by mass or more, more preferably 10% by mass or more, and further preferably 20% by mass or more or 25% by mass or more. Although the upper limit of content of an epoxy resin is not specifically limited, Preferably it is 50 mass% or less, More preferably, it is 45 mass% or less, More preferably, it is 40 mass% or less.

  In addition, in this invention, content of each component which comprises a resin composition (or layer) is when the sum total of the non-volatile component in a resin composition (or layer) shall be 100 mass% unless there is separate description. Value.

  The epoxy equivalent of the epoxy resin is preferably 50 to 3000, more preferably 80 to 2000, and still more preferably 110 to 1000. By becoming this range, the crosslinked density of hardened | cured material becomes sufficient and it can bring about an insulating layer with small surface roughness. The epoxy equivalent can be measured according to JIS K7236, and is the mass of a resin containing 1 equivalent of an epoxy group.

  The weight average molecular weight of an epoxy resin becomes like this. Preferably it is 100-5000, More preferably, it is 250-3000, More preferably, it is 400-1500. Here, the weight average molecular weight of the epoxy resin is a weight average molecular weight in terms of polystyrene measured by a gel permeation chromatography (GPC) method.

-(B) Curing agent-
The curing agent is not particularly limited as long as it has a function of curing the epoxy resin. For example, a phenolic curing agent, a naphthol curing agent, an active ester curing agent, a benzoxazine curing agent, a cyanate ester curing agent, and Examples thereof include carbodiimide curing agents. A hardening | curing agent may be used individually by 1 type, or may use 2 or more types together.

  As the phenol-based curing agent and the naphthol-based curing agent, a phenol-based curing agent having a novolak structure or a naphthol-based curing agent having a novolak structure is preferable from the viewpoint of heat resistance and water resistance. Moreover, from a viewpoint of adhesiveness with a conductor layer, a nitrogen-containing phenol type hardening | curing agent is preferable and a triazine frame | skeleton containing phenol type hardening | curing agent is more preferable. Among these, a triazine skeleton-containing phenol novolac curing agent is preferable from the viewpoint of highly satisfying heat resistance, water resistance, and adhesion to the conductor layer.

  Specific examples of the phenol-based curing agent and the naphthol-based curing agent include, for example, “MEH-7700”, “MEH-7810”, “MEH-7785” manufactured by Meiwa Kasei Co., Ltd., and Nippon Kayaku Co., Ltd. “NHN”, “CBN”, “GPH”, “SN170”, “SN180”, “SN190”, “SN475”, “SN485”, “SN495”, “SN375”, “SN395” manufactured by Nippon Steel & Sumikin Co., Ltd. “LA7052”, “LA7054”, “LA3018”, “EXB-9500” manufactured by DIC Corporation, and the like.

  From the viewpoint of obtaining an insulating layer having a small surface roughness after the roughening treatment and obtaining an insulating layer having excellent adhesion to the conductor layer, an active ester curing agent is also preferred. Although there is no restriction | limiting in particular as an active ester type hardening | curing agent, Generally ester groups with high reaction activity, such as phenol ester, thiophenol ester, N-hydroxyamine ester, ester of heterocyclic hydroxy compound, are in 1 molecule. A compound having two or more in the above is preferably used. The active ester curing agent is preferably obtained by a condensation reaction between a carboxylic acid compound and / or a thiocarboxylic acid compound and a hydroxy compound and / or a thiol compound. In particular, from the viewpoint of improving heat resistance, an active ester curing agent obtained from a carboxylic acid compound and a hydroxy compound is preferable, and an active ester 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, phthalic acid, isophthalic acid, terephthalic acid, and pyromellitic acid. Examples of the phenol compound or naphthol compound include hydroquinone, resorcin, bisphenol A, bisphenol F, bisphenol S, phenolphthaline, methylated bisphenol A, methylated bisphenol F, methylated bisphenol S, phenol, o-cresol, m- Cresol, p-cresol, catechol, α-naphthol, β-naphthol, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, phloroglucin, Benzenetriol, dicyclopentadiene type diphenol compound, phenol novolac and the like can be mentioned. Here, the “dicyclopentadiene type diphenol compound” refers to a diphenol compound obtained by condensing two molecules of phenol with 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 acetylated product of a phenol novolac, and an active ester compound containing a benzoylated product of a phenol novolac are preferred, Of these, active ester compounds having a naphthalene structure and active ester compounds having a dicyclopentadiene type diphenol structure are more preferred. The “dicyclopentadiene type diphenol structure” represents a divalent structural unit composed of phenylene-dicyclopentalene-phenylene.

  As a commercial product of an active ester type curing agent, as an active ester compound containing a dicyclopentadiene type diphenol structure, “EXB9451”, “EXB9460”, “EXB9460S”, “HPC-8000-65T” (manufactured by DIC Corporation) ), “EXB9416-70BK” (manufactured by DIC Corporation) as an active ester compound containing a naphthalene structure, “DC808” (manufactured by Mitsubishi Chemical Corporation) as an active ester compound containing an acetylated product of phenol novolac, and benzoyl of phenol novolac Examples of the active ester compound containing a compound include “YLH1026” (manufactured by Mitsubishi Chemical Corporation).

  Specific examples of the benzoxazine-based curing agent include “HFB2006M” manufactured by Showa Polymer Co., Ltd., “Pd” and “Fa” manufactured by Shikoku Kasei Kogyo Co., Ltd.

  Examples of the cyanate ester curing agent include bisphenol A dicyanate, polyphenol cyanate, oligo (3-methylene-1,5-phenylene cyanate), 4,4′-methylenebis (2,6-dimethylphenyl cyanate), 4,4. '-Ethylidene diphenyl dicyanate, hexafluorobisphenol A dicyanate, 2,2-bis (4-cyanate) phenylpropane, 1,1-bis (4-cyanatephenylmethane), bis (4-cyanate-3,5-dimethyl) Bifunctional cyanate resins such as phenyl) methane, 1,3-bis (4-cyanatephenyl-1- (methylethylidene)) benzene, bis (4-cyanatephenyl) thioether, and bis (4-cyanatephenyl) ether, phenol Novolac and K Polyfunctional cyanate resin derived from tetrazole novolac, these cyanate resins and partially triazine of prepolymer. Specific examples of the cyanate ester curing agent include “PT30” and “PT60” (both phenol novolak polyfunctional cyanate ester resins) and “BA230” (part or all of bisphenol A dicyanate) manufactured by Lonza Japan Co., Ltd. And the like, and the like, and the like.

  Specific examples of the carbodiimide curing agent include “V-03” and “V-07” manufactured by Nisshinbo Chemical Co., Ltd.

  The amount ratio of the epoxy resin and the curing agent is preferably a ratio of [total number of epoxy groups of the epoxy resin]: [total number of reactive groups of the curing agent] in the range of 1: 0.2 to 1: 2. 1: 0.3-1: 1.5 are more preferable, and 1: 0.4-1: 1.2 are still more preferable. Here, the reactive group of the curing agent is an active hydroxyl group, an active ester group or the like, and varies depending on the type of the curing agent. Moreover, the total number of epoxy groups of the epoxy resin is a value obtained by dividing the value obtained by dividing the solid mass of each epoxy resin by the epoxy equivalent for all epoxy resins, and the total number of reactive groups of the curing agent is: The value obtained by dividing the solid mass of each curing agent by the reactive group equivalent is the total value for all curing agents. By setting the amount ratio of the epoxy resin and the curing agent in such a range, the heat resistance of the cured product of the resin composition is further improved.

  In one embodiment, the first resin composition includes the aforementioned (a) epoxy resin and (b) a curing agent. The first resin composition comprises (a) a mixture of a liquid epoxy resin and a solid epoxy resin as an epoxy resin (the mass ratio of liquid epoxy resin: solid epoxy resin is preferably 1: 0.1 to 1: 8, More preferably 1: 0.3 to 1: 7, and still more preferably 1: 0.6 to 1: 6), and (b) a phenolic curing agent, a naphthol curing agent, an active ester curing agent and One or more selected from the group consisting of cyanate ester curing agents (preferably one or more selected from the group consisting of phenolic curing agents, naphthol curing agents and active ester curing agents) are included. preferable.

  Although content of the hardening | curing agent in the 1st resin composition is not specifically limited, Preferably it is 30 mass% or less, More preferably, it is 25 mass% or less, More preferably, it is 20 mass% or less, More preferably, it is 18 mass% or less. It is. The lower limit is not particularly limited but is preferably 3% by mass or more.

-(C) Inorganic filler-
The first resin composition may further contain an inorganic filler. The material of the inorganic filler is not particularly limited. For example, silica, alumina, glass, cordierite, silicon oxide, barium sulfate, barium carbonate, talc, clay, mica powder, zinc oxide, hydrotalcite, boehmite, water Aluminum oxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, magnesium oxide, boron nitride, aluminum nitride, manganese nitride, aluminum borate, strontium carbonate, strontium titanate, calcium titanate, magnesium titanate, bismuth titanate, titanium oxide , Zirconium oxide, barium titanate, barium zirconate titanate, barium zirconate, calcium zirconate, zirconium phosphate, and zirconium tungstate phosphate. Of these, silica is particularly preferred. Moreover, spherical silica is preferable as the silica. An inorganic filler may be used individually by 1 type, and may be used in combination of 2 or more type.

  The average particle size of the inorganic filler used in the first resin composition is not particularly limited, but is preferably 600 nm or less, more preferably from the viewpoint of obtaining an insulating layer having a small surface roughness and improving the fine wiring formability. Is 300 nm or less, more preferably 200 nm or less, even more preferably 150 nm or less, or 120 nm or less. Although the minimum of this average particle diameter is not specifically limited, Usually, it is 5 nm or more. Examples of commercially available inorganic fillers having such an average particle size include, for example, “YC100C”, “YA050C”, “YA050C-MJE”, “YA010C” manufactured by Admatechs, manufactured by Denki Kagaku Kogyo Co., Ltd. “UFP-30”, “Silfil NSS-3N”, “Silfil NSS-4N”, “Silfil NSS-5N” manufactured by Tokuyama Corporation, “SOC2”, “SOC1” manufactured by Admatechs Corporation, and the like.

  The average particle diameter of the inorganic filler can be measured by a laser diffraction / scattering method based on Mie scattering theory. Specifically, the particle size distribution of the inorganic filler can be prepared on a volume basis by a laser diffraction / scattering particle size distribution measuring apparatus, and the median diameter can be measured as the average particle diameter. As the measurement sample, an inorganic filler dispersed in water by ultrasonic waves can be preferably used. As the laser diffraction / scattering particle size distribution measuring apparatus, “LA-500” manufactured by Horiba, Ltd. or the like can be used.

  Inorganic fillers are aminosilane coupling agents, epoxysilane coupling agents, mercaptosilane coupling agents, silane coupling agents, organosilazane compounds, titanate coupling agents from the viewpoint of improving moisture resistance and dispersibility. It is preferable that it is processed with 1 or more types of surface treating agents. Examples of commercially available surface treatment agents include “KBM403” (3-glycidoxypropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., and “KBM803” (3-mercaptopropyltrimethoxy manufactured by Shin-Etsu Chemical Co., Ltd.). Silane), Shin-Etsu Chemical "KBE903" (3-aminopropyltriethoxysilane), Shin-Etsu Chemical "KBM573" (N-phenyl-3-aminopropyltrimethoxysilane), Shin-Etsu Chemical "SZ-31" (hexamethyldisilazane) manufactured by KK, "KBM103" (phenyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., "KBM-4803" manufactured by Shin-Etsu Chemical Co., Ltd. (long-chain epoxy type) Silane coupling agent).

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

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

  The content of the inorganic filler in the first resin composition is not particularly limited, but is preferably 60% by mass or less, more preferably 55% by mass or less, still more preferably 50% by mass or less, and even more preferably 48% by mass. Hereinafter, it is 46 mass% or less, or 44 mass% or less. The lower limit of 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, polyamideimide resin, polyethersulfone resin, polyphenylene ether resin, and polysulfone resin. A thermoplastic resin may be used individually by 1 type, or may use 2 or more types together.

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

  Examples of the phenoxy resin include bisphenol A skeleton, bisphenol F skeleton, bisphenol S skeleton, bisphenolacetophenone skeleton, novolac skeleton, biphenyl skeleton, fluorene skeleton, dicyclopentadiene skeleton, norbornene skeleton, naphthalene skeleton, anthracene skeleton, adamantane skeleton, terpene Examples thereof include phenoxy resins having a skeleton and one or more skeletons selected from the group consisting of a trimethylcyclohexane skeleton. The terminal of the phenoxy resin may be any functional group such as a phenolic hydroxyl group or an epoxy group. A phenoxy resin may be used individually by 1 type, or may use 2 or more types together. Specific examples of the phenoxy resin include “1256” and “4250” (both bisphenol A skeleton-containing phenoxy resin), “YX8100” (bisphenol S skeleton-containing phenoxy resin), and “YX6954” (manufactured by Mitsubishi Chemical Corporation). In addition, “FX280” and “FX293” manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., “YX7180BH40”, “YX7553BH30”, “YL7769BH30” manufactured by Mitsubishi Chemical Corporation, “YL6794”, “YL7213”, “YL7290”, “YL7482” and the like.

  As the acrylic resin, a functional group-containing acrylic resin is preferable, an epoxy group-containing acrylic resin is more preferable, and an epoxy group-containing acrylic ester copolymer resin is more preferable. When using a functional group containing acrylic resin as an acrylic resin, the functional group equivalent becomes like this. Preferably it is 1000-50000, More preferably, it is 2500-30000.

  Specific examples of the acrylic resin include “SG-80H” and “SG-P3” (epoxy group-containing acrylic ester copolymer resin) manufactured by Nagase ChemteX Corporation.

  Specific examples of the polyvinyl acetal resin include: Electric Butyral 4000-2, 5000-A, 6000-C, 6000-EP manufactured by Denki Kagaku Kogyo Co., Ltd., S-Lec BH Series, BX Series manufactured by Sekisui Chemical Co., Ltd. Examples include KS series (specifically, “KS-1”, etc.), BL series, BM series, and the like.

  Specific examples of the polyimide resin include “Rika Coat SN20” and “Rika Coat PN20” manufactured by Shin Nippon Rika Co., Ltd. Specific examples of the polyimide resin include linear polyimide obtained by reacting a bifunctional hydroxyl group-terminated polybutadiene, a diisocyanate compound and a tetrabasic acid anhydride (Japanese Patent Laid-Open No. 2006-37083), a polysiloxane skeleton-containing polyimide. Examples thereof include modified polyimides such as JP-A Nos. 2002-12667 and 2000-319386.

  Specific examples of the polyamide-imide resin include “Bilomax HR11NN” and “Bilomax HR16NN” manufactured by Toyobo Co., Ltd. Specific examples of the polyamideimide resin also include modified polyamideimides such as polysiloxane skeleton-containing polyamideimides “KS9100” and “KS9300” manufactured by Hitachi Chemical Co., Ltd.

  Specific examples of the polyethersulfone resin include “PES5003P” manufactured by Sumitomo Chemical Co., Ltd.

  Specific examples of the polysulfone resin include polysulfone “P1700” and “P3500” manufactured by Solvay Advanced Polymers Co., Ltd.

  The content of the thermoplastic resin in the first resin composition is not particularly limited, but is preferably 0.1% by mass or more, more preferably 1% by mass or more, further preferably 3% by mass or more, 5% by mass or more or It is 6 mass% or more. Although the upper limit of content of a thermoplastic resin is not specifically limited, Preferably it is 30 mass% or less, More preferably, it is 20 mass% or less, More preferably, it is 10 mass% or less.

-(E) Curing accelerator-
The first resin composition may further contain a curing accelerator. Examples of the curing accelerator include phosphorus-based curing accelerators, amine-based curing accelerators, imidazole-based curing accelerators, guanidine-based curing accelerators, phosphorus-based curing accelerators, amine-based curing accelerators, and imidazole-based accelerators. A curing accelerator is preferable, and an amine-based curing accelerator and an imidazole-based curing accelerator are more preferable. A hardening accelerator may be used individually by 1 type, and may be used in combination of 2 or more type.

  Examples of phosphorus curing accelerators include triphenylphosphine, phosphonium borate compounds, tetraphenylphosphonium tetraphenylborate, n-butylphosphonium tetraphenylborate, tetrabutylphosphonium decanoate, (4-methylphenyl) triphenylphosphonium thiocyanate. , Tetraphenylphosphonium thiocyanate, butyltriphenylphosphonium thiocyanate and the like, and triphenylphosphine and tetrabutylphosphonium decanoate are preferable.

  Examples of amine curing accelerators include trialkylamines such as triethylamine and tributylamine, 4-dimethylaminopyridine, benzyldimethylamine, 2,4,6, -tris (dimethylaminomethyl) phenol, 1,8-diazabicyclo. (5,4,0) -undecene and the like are mentioned, and 4-dimethylaminopyridine and 1,8-diazabicyclo (5,4,0) -undecene are preferable.

  Examples of the imidazole curing accelerator include 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazolium trimellitate, 1-cyanoethyl- 2 Phenylimidazolium trimellitate, 2,4-diamino-6- [2'-methylimidazolyl- (1 ')]-ethyl-s-triazine, 2,4-diamino-6- [2'-undecylimidazolyl- (1 ′)]-ethyl-s-triazine, 2,4-diamino-6- [2′-ethyl-4′-methylimidazolyl- (1 ′)]-ethyl-s-triazine, 2,4-diamino- 6- [2′-Methylimidazolyl- (1 ′)]-ethyl-s-triazine isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl- 4-methyl-5-hydroxymethylimidazole, 2,3-dihydro-1H-pyrrolo [1,2-a] benzimidazole, 1-dodecyl-2-methyl Examples include imidazole compounds such as 3-benzylimidazolium chloride, 2-methylimidazoline, and 2-phenylimidazoline, and adducts of imidazole compounds and epoxy resins, such as 2-ethyl-4-methylimidazole and 1-benzyl-2-phenyl. Imidazole is preferred.

  Commercially available products may be used as the imidazole curing accelerator, and examples thereof include “P200-H50” manufactured by Mitsubishi Chemical Corporation.

  Examples of the guanidine curing accelerator include dicyandiamide, 1-methylguanidine, 1-ethylguanidine, 1-cyclohexylguanidine, 1-phenylguanidine, 1- (o-tolyl) guanidine, dimethylguanidine, diphenylguanidine, trimethylguanidine, Tetramethylguanidine, pentamethylguanidine, 1,5,7-triazabicyclo [4.4.0] dec-5-ene, 7-methyl-1,5,7-triazabicyclo [4.4.0] Deca-5-ene, 1-methyl biguanide, 1-ethyl biguanide, 1-n-butyl biguanide, 1-n-octadecyl biguanide, 1,1-dimethyl biguanide, 1,1-diethyl biguanide, 1-cyclohexyl biguanide, 1 -Allyl biguanide, 1-phenyl biguanide, 1- ( - tolyl) biguanide, and the like, dicyandiamide, 1,5,7-triazabicyclo [4.4.0] dec-5-ene are preferred.

  Although content of the hardening accelerator in a 1st resin composition is not specifically limited, When the non-volatile component total amount of an epoxy resin and a hardening | curing agent is 100 mass%, it is in the range of 0.05 mass%-3 mass%. It is preferable to use it.

-(F) Flame retardant-
The first resin composition may further contain a flame retardant. Examples of the flame retardant include an organic phosphorus flame retardant, an organic nitrogen-containing phosphorus compound, a nitrogen compound, a silicone flame retardant, and a metal hydroxide. A flame retardant may be used individually by 1 type, or may use 2 or more types together.

  Commercially available products may be used as the flame retardant, and examples thereof include “HCA-HQ” manufactured by Sanko Co., Ltd.

  The content of the flame retardant in the first resin composition layer is not particularly limited, but is preferably 0.5% by mass to 20% by mass, more preferably 1% by mass to 15% by mass, and still more preferably 1.5% by mass. % To 10% by mass is more preferable.

-(G) Organic filler-
The first resin composition may further contain an organic filler. As the organic filler, any organic filler that can be used for forming an insulating layer of a printed wiring board may be used. Examples thereof include rubber particles, polyamide fine particles, and silicone particles, and rubber particles are preferable.

  A commercially available product may be used as the rubber particles, and examples thereof include “AC3816N” manufactured by Aika Industry Co., Ltd.

  The content of the organic filler in the first resin composition is preferably 1% by mass to 20% by mass, more preferably 2% by mass to 10% by mass.

-Other ingredients-
The first resin composition may contain other additives as necessary. Examples of such other additives include organic metals such as organic copper compounds, organic zinc compounds, and organic cobalt compounds. Examples include compounds and resin additives such as organic fillers, thickeners, antifoaming agents, leveling agents, adhesion-imparting agents, and coloring agents.

  The thickness of the first resin composition layer is preferably 0.3 to 10 μm from the viewpoint of obtaining a thin insulating layer and the adhesiveness with the conductor layer. The lower limit of the thickness of the first resin composition layer is more preferably 0.5 μm or more, further preferably 1 μm or more, 1.5 μm or more, 2 μm or more, 2.5 μm or more, or 3 μm or more. Particularly, when the thickness of the first resin composition layer is 1 μm or more, the adhesion with the conductor layer can be further enhanced. The upper limit of the thickness of the first resin composition layer is more preferably 8 μm or less, still more preferably 7 μm or less, 6 μm or less, or 5 μm or less. In addition, it is preferable that the thickness of the 1st resin composition layer is thinner than the thickness of the 2nd resin composition layer. The thickness of the first resin composition layer can be measured according to the procedure described in [Measurement of thickness of each layer of resin sheet] described later.

  As described above, the first resin composition layer is bonded to the support, and when the printed wiring board is manufactured, a region in the vicinity of the surface of the insulating layer on which the conductor layer is formed is formed. Therefore, the first resin composition layer is a resin composition layer (resin composition layer for forming a conductor layer) on which a conductor layer is formed, and among them, a resin on which a plated conductor layer is formed It is suitable as a composition layer (resin composition layer for plating formation).

<< Intermediate layer >>
The resin sheet of the present invention has an intermediate layer provided on the first resin composition layer.

  From the viewpoint of sufficiently reducing the average linear thermal expansion coefficient (hereinafter also referred to as thermal expansion coefficient) of the obtained insulating layer and suppressing warpage in the component mounting process, the intermediate layer has a high content of inorganic filler. Including. When the total amount of nonvolatile components in the intermediate layer is 100% by mass, the content of the inorganic filler in the intermediate layer is 80% by mass or more, preferably 81% by mass or more, more preferably 83% by mass or more, Preferably it is 85 mass% or more. By increasing the content of the inorganic filler, not only can the thermal expansion coefficient of the resulting insulating layer be reduced, but also the rigidity of the resulting insulating layer can be increased, even in the case of a thin film, in the component mounting process. An insulating layer capable of suppressing warpage can be realized. However, when the content of the inorganic filler is high, there are problems that the layer is easily brittlely broken and the handleability is lowered, the circuit embedding property and the adhesion with the conductor layer are lowered. In this regard, in the resin sheet of the present invention having a layer structure in which the intermediate layer is sandwiched between the first and second resin composition layers, the inclusion of the inorganic filler in the intermediate layer without problems such as a decrease in handleability The amount can be further increased. For example, the content of the inorganic filler in the intermediate layer is 87 mass% or more, 89 mass% or more, 90 mass% or more, 92 mass% or more, 94 mass% or more, 96 mass% or more, or 98 mass% or more. Or may be 100% by mass.

  In the intermediate layer, the inorganic filler described for the first resin composition may be used as the inorganic filler, and silica is particularly preferable. Glass fibers are also suitable as the inorganic filler used in the intermediate layer. Therefore, in one embodiment, the inorganic filler used for the intermediate layer is silica or glass fiber. As the silica used for the intermediate layer, colloidal silica and spherical silica are suitable. Therefore, in one embodiment, the inorganic filler used in the intermediate layer is colloidal silica, spherical silica or glass fiber. Among them, from the viewpoint of obtaining an insulating layer having a low coefficient of thermal expansion and high rigidity, the inorganic filler used for the intermediate layer is colloidal silica, spherical silica having an average particle diameter of 10 μm or less, or glass fiber having an average filament diameter of 10 μm or less. Is preferred.

  Colloidal silica is a dispersion in which silica fine particles are dispersed in a dispersion medium. In the present invention, the dispersion medium may be another component constituting the intermediate layer (for example, a resin component such as an epoxy resin or a phenoxy resin). In the colloidal silica, the shape of the silica fine particles is preferably a chain from the viewpoint of sufficiently suppressing warpage in the component mounting process. Hereinafter, colloidal silica in which the silica fine particles have a chain shape is referred to as “chain colloidal silica”. The term “chain” as used for colloidal silica means that the aspect ratio (chain length / chain diameter ratio) of the silica fine particles is 2 or more. The aspect ratio of the chain colloidal silica is preferably 3 or more, more preferably 4 or more, and still more preferably 5 or more. The upper limit of the aspect ratio is not particularly limited, but can usually be 1000 or less, 500 or less, 100 or less, and the like.

  The average particle size of the colloidal silica is not particularly limited, but is preferably 0.5 μm or less, more preferably 0.4 μm or less, still more preferably 0.3 μm or less or 0.2 μm or less. Although it does not specifically limit about a minimum, Preferably it is 0.01 micrometer or more, More preferably, it is 0.02 micrometer or more, More preferably, it is 0.03 micrometer or more. The average particle diameter is measured by a dynamic light scattering method and is a sphere equivalent average diameter.

  Colloidal silica can use a commercial item, for example, "MEK-ST-UP", "MEK-ST-40", "MEK-ST-L", "MEK-ST-ZL" manufactured by Nissan Chemical Industries, Ltd. "," MEK-AC-4130Y "and the like. Colloidal silica may be used individually by 1 type, and may use 2 or more types.

  As the glass fiber, various known glass fibers can be used. Examples of the glass fiber material include E glass, C glass, A glass, S glass, D glass, NE glass, T glass, H glass, quartz glass, and Q glass. Among them, S glass, T glass, quartz Glass and Q glass are preferred. The form of the glass fiber may be any of yarn, roving, milled fiber, strand, chopped strand and the like.

  The average filament diameter (average diameter) of the glass fiber is not particularly limited, but is preferably 10 μm or less, more preferably 8 μm or less, and even more preferably 5 μm or less from the viewpoint of obtaining a highly rigid insulating layer with a low coefficient of thermal expansion. It is. Although it does not specifically limit about a minimum, Preferably it is 1 micrometer or more, More preferably, it is 2 micrometers or more, More preferably, it is 3 micrometers or more.

  The chop length (average fiber length) of the glass fiber is not particularly limited, but is preferably 100 μm or less, more preferably 80 μm or less, and even more preferably 50 μm or less from the viewpoint of obtaining a highly rigid insulating layer with a low coefficient of thermal expansion. It is. Although there is no restriction | limiting in particular about a minimum, Preferably it is 10 micrometers or more, More preferably, it is 15 micrometers or more, More preferably, it is 20 micrometers or more.

  A commercially available glass fiber can be used. For example, “SQCBC-02-3”, “SQCBC-02-3A”, “SQCBC-02-3B”, “SQCCE225-02-3” manufactured by Shin-Etsu Quartz Co., Ltd. , “SQMBC-00”, “EFDE-50-01”, “EFDE-90-01”, “EFDE-50-31” manufactured by Central Glass Co., Ltd., and the like. A glass fiber may be used individually by 1 type, and may use 2 or more types.

  The average particle diameter of the spherical silica contained in the intermediate layer is preferably 10 μm or less, more preferably 8 μm or less, and even more preferably 5 μm or less, 3 μm or less, from the viewpoint of obtaining a highly rigid insulating layer having a low coefficient of thermal expansion. 1 μm or less. The lower limit may be 0.01 μm or more, 0.1 μm or more from the viewpoint of improving the filling property. Examples of commercially available spherical silica include “SOC4”, “SOC2”, and “SOC1” manufactured by Admatechs Co., Ltd.

  The inorganic filler contained in the intermediate layer is preferably treated with a surface treatment agent. The kind of surface treating agent and the degree of surface treatment are as described in the << first resin composition layer >> column.

  The intermediate layer may contain other materials in addition to the inorganic filler. In such a case, other materials that may be included in the composition for forming the intermediate layer (hereinafter also referred to as “intermediate layer forming composition”) include, for example, << first resin composition layer Examples of the components (a), (b), (d) to (g) and other additives described in the >> column. In one embodiment, the intermediate layer forming composition (and thus the intermediate layer) includes (d) a thermoplastic resin. (D) A phenoxy resin is suitable as the thermoplastic resin. Accordingly, in a preferred embodiment, the intermediate layer forming composition comprises a phenoxy resin.

  When the intermediate layer forming composition contains a phenoxy resin, it is preferable that the Tg (glass transition point) of the phenoxy resin is low from the viewpoint of further suppressing warpage. For example, the Tg of the phenoxy resin is preferably 100 ° C. or lower, and more preferably 80 ° C. or lower. In such a case, the lower limit of the Tg of the phenoxy resin is not particularly limited, but can usually be −30 ° C. or higher. Alternatively, from the viewpoint of processability, the Tg of the phenoxy resin may be high. In such a case, the Tg of the phenoxy resin is preferably 120 ° C. or higher, more preferably 130 ° C. or higher, and the upper limit of Tg can be usually 200 ° C. or lower. In addition, when the intermediate layer forming composition contains an epoxy resin, the Tg of the epoxy resin may be low or high for the same reason as described above, and a preferable Tg range is the same as described above.

  When the intermediate layer forming composition contains (d) a thermoplastic resin, the content of (d) the thermoplastic resin is preferably 1% by mass or more, more preferably 2% by mass or more. The upper limit of the content is preferably 20% by mass or less, more preferably 15% by mass or less, or 10% by mass or less.

  In one embodiment, the intermediate layer forming composition includes (a) an epoxy resin. (A) As an epoxy resin, an epoxy resin containing a solid epoxy resin (the content of the solid epoxy resin in the epoxy resin is preferably 30% by mass or more, more preferably 40% by mass or more, and further preferably 50% by mass) As mentioned above, it is 60 mass% or more, 70 mass% or more, 80 mass% or more, or 90 mass% or more, and only a solid epoxy resin may be suitable.

  When the intermediate layer forming composition contains (a) an epoxy resin, the content of (a) the epoxy resin is preferably 1% by mass or more, more preferably 2% by mass or more. The upper limit of the content is preferably 20% by mass or less, more preferably 15% by mass or less, and still more preferably 10% by mass or less.

  When the intermediate layer forming composition includes (a) an epoxy resin, it is preferable that the intermediate layer forming composition further includes (b) a curing agent. (B) Content of a hardening | curing agent can be 2-15 mass%.

  The thickness of the intermediate layer is preferably 1 to 20 μm from the viewpoint of obtaining a thin insulating layer and suppressing warpage. The lower limit of the thickness of the intermediate layer is more preferably 1.5 μm or more, further preferably 3 μm or more, or 5 μm or more. The upper limit of the thickness of the intermediate layer is more preferably 18 μm or less, still more preferably 17 μm or less, 15 μm or less, 13 μm or less, or 11 μm or less. The thickness of the intermediate layer can be measured according to the procedure described in [Measurement of thickness of each layer of resin sheet] described later.

  The thickness of the intermediate layer is preferably 5% or more, more preferably 10% or more, and further preferably 20% or more of the total thickness of the adhesive layer from the viewpoint of suppressing warpage. The upper limit is not particularly limited, but is preferably 85% or less, more preferably 70% or less, still more preferably 60% or less, 50% or less, or 40% or less.

<< second resin composition layer >>
The resin sheet of the present invention has a second resin composition layer provided on the intermediate layer. The second resin composition layer is a layer that is bonded to the inner layer substrate in the production of the printed wiring board. The resin composition used for the formation of the second resin composition layer (hereinafter also referred to as “second resin composition”) is not particularly limited, and achieves good lamination properties and the cured product is Any material having sufficient hardness and insulating properties may be used.

  From the viewpoint of obtaining an insulating layer having a low coefficient of thermal expansion, the resin composition used to form the second resin composition layer (hereinafter also referred to as “second resin composition”) includes an inorganic filler. It is preferable. The content of the inorganic filler in the second resin composition is preferably 30% by mass or more, more preferably 40% by mass or more, and further preferably 50% by mass from the viewpoint of reducing the thermal expansion coefficient of the obtained insulating layer. % Or more, 60 mass% or more, or 70 mass% or more. The upper limit of the content of the inorganic filler in the second resin composition is preferably 80% by mass or less, more preferably 78% by mass or less, and even more preferably 76% by mass or less, or 74 from the viewpoint of improving the laminate property. It is below mass%.

  As an inorganic filler contained in a 2nd resin composition, the inorganic filler demonstrated about the 1st resin composition is mentioned, for example, Among these, a silica is preferable and a spherical silica is more preferable.

  The average particle diameter of the inorganic filler contained in the second resin composition is preferably 1 μm or less, more preferably 0.8 μm or less, and more preferably 0.6 μm or less from the viewpoint of improving insulation reliability and small diameter via processability. Is more preferable. Although it does not specifically limit about a minimum, Usually, they are 0.01 micrometer or more and 0.1 micrometer or more. Examples of commercially available inorganic fillers having such an average particle diameter include “SOC4”, “SOC2”, and “SOC1” manufactured by Admatechs Co., Ltd.

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

  In a preferred embodiment, the second resin composition (and hence the second resin composition layer) contains 80% by mass or less of an inorganic filler having an average particle size of 1 μm or less.

  Other materials included in the second resin composition include, for example, (a) a curable resin including an epoxy resin, and (b) a curing agent described in the section <First resin composition layer>. Is mentioned. Accordingly, in one embodiment, the second resin composition includes (a) an epoxy resin, (b) a curing agent, and (c) an inorganic filler. Suitable examples of each component are as described in the <First resin composition layer> column. Among them, the second resin composition includes (a) a liquid epoxy resin and a solid epoxy resin as an epoxy resin. (The mass ratio of liquid epoxy resin: solid epoxy resin is preferably in the range of 1: 0.1 to 1: 4, more preferably in the range of 1: 0.3 to 1: 3.5, and 1: 0. The range of .6 to 1: 3 is more preferable, and the range of 1: 0.8 to 1: 2.5 is particularly preferable.) (B) Phenol curing agent, naphthol curing agent, active ester One or more selected from the group consisting of curing agents and cyanate ester curing agents (preferably one or more selected from the group consisting of phenolic curing agents, naphthol curing agents and active ester curing agents), c) As an inorganic filler Preferably contains silica, respectively.

  Although content of (a) epoxy resin in the 2nd resin composition is not specifically limited, Preferably it is 3 mass%-50 mass%, More preferably, it is 5 mass%-45 mass%, More preferably, it is 5 mass%- It is 40 mass%, More preferably, it is 7 mass%-35 mass%.

  The amount ratio of (a) epoxy resin and (b) curing agent in the second resin composition may be the same as that described in the section <First resin composition layer>.

  Although content of (b) hardening | curing agent in 2nd resin composition is not specifically limited, Preferably it is 30 mass% or less, More preferably, it is 25 mass% or less, More preferably, it is 20 mass% or less, More preferably, it is 15 It is 10 mass% or less. The lower limit is not particularly limited but is preferably 3% by mass or more.

  The second resin composition may further contain one or more components selected from the group consisting of (d) a thermoplastic resin, (e) a curing accelerator, (f) a flame retardant, and (g) an organic filler. Good. Suitable examples of these components (d) to (g) are as described in the section <First resin composition layer>. Although content of the (d) thermoplastic resin in a 2nd resin composition is not specifically limited, Preferably it is 0.1 mass%-20 mass%, More preferably, it is 0.5 mass%-10 mass%. The content of (e) the curing accelerator in the second resin composition is preferably 0.05% by mass when the total amount of nonvolatile components of (a) the epoxy resin and (b) the curing agent is 100% by mass. ˜3 mass%. The content of the flame retardant (f) in the second resin composition is not particularly limited, but is preferably 0.5% by mass to 10% by mass, more preferably 1% by mass to 9% by mass, and even more preferably 1%. 0.5 mass% to 8 mass%. Although content of the (g) organic filler in the 2nd resin composition is not specifically limited, Preferably it is 1 mass%-10 mass%, More preferably, it is 2 mass%-5 mass%.

  The second resin composition may contain other additives as necessary. Examples of such other additives include organic metals such as organic copper compounds, organic zinc compounds, and organic cobalt compounds. Examples include compounds and resin additives such as organic fillers, thickeners, antifoaming agents, leveling agents, adhesion-imparting agents, and coloring agents.

  The thickness of the second resin composition layer is not particularly limited as long as an insulating layer having a desired thickness can be obtained, but is preferably 3 to 200 μm. The lower limit of the thickness of the second resin composition layer is more preferably 5 μm or more, further preferably 10 μm or more, or 15 μm or more. The upper limit of the thickness of the second resin composition layer is more preferably 180 μm or less, further preferably 160 μm or less, 150 μm or less, 140 μm or less, 120 μm or less, or 100 μm or less, 80 μm or less, 60 μm, in order to increase the suppression of warpage. Or less, or 40 μm or less. The thickness of the second resin composition layer can be measured according to the procedure described in [Measurement of thickness of each layer of resin sheet] described later.

  The minimum melt viscosity of the second resin composition layer is preferably 10,000 poise (1000 Pa · s) or less, more preferably 8000 poise (800 Pa · s) or less, and 5000 poise (500 Pa · s) from the viewpoint of obtaining good circuit embedding properties. The following is more preferable. The lower limit of the minimum melt viscosity is preferably 500 poise (50 Pa · s) or more, more preferably 800 poise (80 Pa · s) or more, and 1000 poise (100 Pa · s) from the viewpoint of suppressing the seepage of the resin in the production of a printed wiring board. The above is more preferable.

  The minimum melt viscosity of the resin composition layer refers to the minimum viscosity exhibited by the resin composition layer when the resin of the resin composition layer is melted. Specifically, when the resin composition layer is heated at a constant temperature increase rate to melt the resin, the melt viscosity decreases in the initial stage as the temperature rises, and then exceeds a certain level, the melt viscosity increases as the temperature rises. To do. The minimum melt viscosity refers to the melt viscosity at such a minimum point. The minimum melt viscosity of the resin composition layer can be measured by a dynamic viscoelastic method, and can be measured, for example, according to the method described in [Measurement of minimum melt viscosity] described later.

  As described above, the second resin composition layer is a layer that is bonded to the inner layer substrate in the production of the printed wiring board. Therefore, the second resin composition layer is suitable as a resin composition layer (resin composition layer for circuit embedding) for embedding the surface circuit of the inner layer substrate.

  In the resin sheet of the present invention, the content (mass%) of the inorganic filler in the first resin composition layer is A, the content (mass%) of the inorganic filler in the intermediate layer is B, and the second When the content (% by mass) of the inorganic filler in the resin composition layer is C, it is preferable that A, B, and C satisfy the relationship of A <C <B. By satisfying such a relationship, the above-described effects expected for each layer can be achieved more suitably.

  In a preferred embodiment, the difference between A and C (C−A) is preferably 10% by mass or more, more preferably 15% by mass or more, still more preferably 20% by mass or more, 25% by mass or more, or 30% by mass. % Or more. Although the upper limit of the difference (C-A) is not particularly limited, it can usually be 80% by mass or less, 70% by mass or less, 60% by mass or less, or 50% by mass or less.

  Moreover, in suitable one Embodiment, the difference (B-C) of B and C becomes like this. Preferably it is 1 mass% or more, More preferably, it is 5 mass% or more, More preferably, it is 10 mass% or more. Although the upper limit of the difference (B-C) is not particularly limited, it can usually be 40% by mass or less, 30% by mass or less, 20% by mass or less, or 15% by mass or less.

  The resin sheet of the present invention may have other layers between the first resin composition layer and the intermediate layer and / or between the intermediate layer and the second resin composition layer.

  The resin sheet of the present invention may further include a protective film on the surface of the second resin composition layer. The protective film contributes to the prevention of adhesion and scratches of dust and the like on the surface of the second resin composition layer. As the material for the protective film, the same materials as described for the support may be used. Although the thickness of a protective film is not specifically limited, For example, they are 1 micrometer-40 micrometers. The resin sheet can be used by peeling off the protective film when producing a printed wiring board.

[Production method of resin sheet]
In the method for producing a resin sheet of the present invention, as long as an adhesive layer having an intended layer configuration (first resin composition layer \ intermediate layer \ second resin composition layer) can be provided on a support. There is no particular limitation, and methods known to those skilled in the art may be used.

  Examples of the method for providing the adhesive layer on the support include a method in which a coating liquid containing a material for forming the adhesive layer is applied on the support and dried to provide the adhesive layer. When the resin sheet of the present invention is produced, a coating liquid containing a first resin composition (hereinafter also referred to as “first coating liquid”) and an intermediate layer forming composition are used as the coating liquid. A liquid (hereinafter also referred to as “intermediate layer forming coating liquid”) and a coating liquid containing a second resin composition (hereinafter also referred to as “second coating liquid”) are used. The method of applying and drying the first coating liquid, the intermediate layer forming coating liquid, and the second coating liquid is the desired layer structure (first resin composition layer \ intermediate layer \ second resin composition There is no particular limitation as long as an adhesive layer having a layer) can be provided, and a known method such as a simultaneous coating method, a tandem coating method, a two-time coating method, a bonding method, or the like may be used. The simultaneous coating method is a method in which a plurality of coating solutions are simultaneously applied and then dried, and the tandem coating method is a method in which a certain coating solution x is applied and preliminarily dried, and then applied to the coating solution x. In this method, another coating liquid is applied and dried. The double coating method is a method in which a certain coating solution x is applied and dried, and then another coating solution is applied onto the resin composition layer and dried. The bonding method is a method in which a certain coating liquid x is applied and dried, and then another resin composition is bonded onto the resin composition layer.

  In a preferred embodiment, the first coating liquid and the intermediate layer forming coating liquid, two liquids, the intermediate layer forming coating liquid and the second coating liquid, or the first coating liquid and the intermediate layer forming. Three liquids of the coating liquid and the second coating liquid are applied by a simultaneous coating method and dried to form an adhesive layer. For example, when two liquids of the first coating liquid and the intermediate layer forming coating liquid are applied by the simultaneous coating method and dried, the first coating liquid is applied onto the support and at the same time the intermediate is formed on the first coating liquid. A layer-forming coating solution is applied and then dried to produce a sheet laminated in the order of support / first resin composition layer / intermediate layer. In this case, the second resin composition layer is formed by applying the second coating liquid onto the intermediate layer and drying it.

  In another preferred embodiment, the first coating liquid and the intermediate layer forming coating liquid, two liquids, the intermediate layer forming coating liquid and the second coating liquid, or the first coating liquid and the intermediate layer. Three liquids of the forming coating liquid and the second coating liquid are applied by a tandem coating method and dried to form an adhesive layer. For example, when two liquids of the first coating liquid and the intermediate layer forming coating liquid are applied by a tandem coating method and dried, the first coating liquid is applied on the support, preliminarily dried, The intermediate layer-forming coating solution is applied onto the coating solution, and then dried to produce a sheet laminated in the order of support / first resin composition layer / intermediate layer. Also in this case, the second resin composition layer is formed by applying the second coating liquid onto the intermediate layer and drying it.

  In addition, an adhesive layer having a desired layer structure (first resin composition layer \ intermediate layer \ second resin composition layer) is provided on the support using a combination of the simultaneous coating method and the tandem coating method. May be.

  Each coating solution can be prepared by dissolving each resin composition or intermediate layer forming composition in a solvent. Although there is no restriction | limiting in particular as a solvent used for preparation of a coating liquid, An organic solvent is preferable. Examples of the organic solvent include ketones such as acetone, methyl ethyl ketone and cyclohexanone, acetates such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate and carbitol acetate, and carbitols such as cellosolve and butyl carbitol. , Aromatic hydrocarbons such as toluene and xylene, amide solvents such as dimethylformamide, dimethylacetamide and N-methylpyrrolidone, and solvent naphtha. An organic solvent may be used individually by 1 type, or may use 2 or more types together. The solvent used for each coating solution may be the same or different.

  The solvent contained in each coating solution is preferably 75% by mass or less, more preferably 65% by mass or less, and even more preferably 55% by mass or less when the total of the nonvolatile components contained in the coating solution is 100% by mass. Particularly preferably, the content is adjusted to 45% by mass or less. The lower limit is preferably 15% by mass or more, more preferably 20% by mass or more.

  The application method of the coating liquid is not particularly limited, but for example, gravure coating method, micro gravure coating method, reverse coating method, kiss reverse coating method, die coating method, slot die method, lip coating method, comma coating method, blade coating Method, roll coating method, knife coating method, curtain coating method, chamber gravure coating method, slot orifice method, spray coating method, dip coating method and the like. Each coating solution may be applied once, or may be applied in several times. When applying in several times, you may apply combining several different application methods. Especially, since the uniformity of the apply | coated layer is favorable, as a coating method, the die-coating method is preferable. The application of the coating liquid is preferably performed in an environment with few foreign matters, such as a clean room, in order to avoid contamination with foreign matters.

  In the simultaneous coating method, for example, the coating can be performed using a known multilayer coating system such as a multi-slit die coater having a plurality of slits for coating different coating solutions.

  The preliminary drying in the tandem coating method is not particularly limited, and may be performed by a known drying method such as heating or hot air blowing. Preliminary drying conditions are not particularly limited, but the residual solvent amount in the coating liquid after preliminary drying is preferably 70% by mass or less and 60% by mass when the total amount of non-volatile components contained in the coating liquid is 100% by mass. Hereinafter, it is pre-dried so that it may become 50 mass% or less, or 40 mass% or less. The lower limit of the residual solvent amount is preferably 15% by mass or more, 20% by mass or more, or 25% by mass or more. Although depending on the boiling point of the organic solvent in the coating solution, for example, when a coating solution containing 30% by mass to 60% by mass of the organic solvent is used, it is 0.1 to 3 minutes at 50 to 150 ° C. (more preferably 60 to 130). It is preferable to dry at 0.2 ° C. for 2 to 2 minutes, more preferably 0.3 to 1.5 minutes at 70 to 120 ° C.

  Drying may be performed by a known drying method such as heating or hot air blowing. The drying conditions are not particularly limited, but the residual solvent amount in the adhesive layer after drying is preferably 10% by mass or less, more preferably 5% by mass when the total amount of nonvolatile components contained in the adhesive layer is 100% by mass. It is dried so that it becomes less than%. The lower limit of the residual solvent amount is not particularly limited, but can usually be 0.1% by mass or more, 0.5% by mass or more. Although depending on the boiling point of the organic solvent in each coating solution, for example, when a coating solution containing 30% by mass to 60% by mass of the organic solvent is used, it is preferably dried at 50 ° C. to 150 ° C. for 3 minutes to 10 minutes. Those skilled in the art can appropriately set suitable drying conditions by simple experiments.

  When manufacturing the resin sheet of this invention, you may further implement the process of laminating | stacking a protective film on the surface (surface on the opposite side to a support body side) of a 2nd resin composition layer. The details of the protective film are as described above.

  The resin sheet of the present invention can provide an insulating layer (cured product of an adhesive layer) having a low coefficient of thermal expansion during the production of a printed wiring board. The average linear thermal expansion coefficient of 30 to 150 ° C. of the cured product of the adhesive layer is preferably 20 ppm / ° C. or less, more preferably 17 ppm / ° C. or less, and further preferably 16 ppm / ° C. or less. Although it does not specifically limit about a minimum, Usually, it is 0.1 ppm / degrees C or more, 0.5 ppm / degrees C or more, or 1 ppm / degrees C or more. The average linear thermal expansion coefficient of the cured product of the adhesive layer can be measured according to the procedure described in [Measurement of average linear thermal expansion coefficient of cured product of adhesive layer] described later.

  The average linear thermal expansion coefficient of 150 to 240 ° C. of the cured product of the adhesive layer is preferably 40 ppm / ° C. or less, more preferably 35 ppm / ° C. or less, and further preferably 30 ppm / ° C. or less. Although it does not specifically limit about a minimum, Usually, it is 0.1 ppm / degrees C or more, 0.5 ppm / degrees C or more, or 1 ppm / degrees C or more. Thus, the resin sheet of the present invention can provide an insulating layer (cured product of adhesive layer) having a low coefficient of thermal expansion even under high temperature conditions, and suppresses the occurrence of warpage in a high temperature environment such as a component mounting process. can do.

  In a preferred embodiment, the average linear thermal expansion coefficient of 30 to 150 ° C. of the cured adhesive layer is 20 ppm / ° C. or less, and the average linear thermal expansion coefficient of 150 to 240 ° C. is 40 ppm / ° C. or less. .

[Printed wiring board and manufacturing method thereof]
A printed wiring board can be manufactured using the resin sheet of the present invention. For example, a printed wiring board can be manufactured by laminating the resin sheet of the present invention on an inner layer substrate and thermally curing it, and then removing the support. Therefore, the printed wiring board of the present invention is characterized by including an insulating layer formed using the resin sheet of the present invention.

Specifically, the printed wiring board of the present invention can be produced by a method including the following steps (I) to (III) using the resin sheet of the present invention.
(I) The step of laminating the resin sheet of the present invention on the inner layer substrate so that the second resin composition layer is joined to the inner layer substrate (II) The step of thermosetting the resin sheet to form the insulating layer (III) ) The step of removing the support

  In step (I), the resin sheet of the present invention is laminated on the inner layer substrate such that the second resin composition layer is bonded to the inner layer substrate.

  The “inner layer substrate” used in the step (I) is mainly a glass epoxy substrate, a metal substrate, a polyester substrate, a polyimide substrate, a BT resin substrate, a thermosetting polyphenylene ether substrate, or one or both sides of the substrate. A circuit board on which a conductor layer (circuit) patterned is formed. Further, when the printed wiring board is manufactured, an inner layer circuit board of an intermediate product in which an insulating layer and / or a conductor layer is further formed is also included in the “inner layer board” in the present invention.

  Lamination of the resin sheet and the inner layer substrate in step (I) may be performed by any conventionally known method, but the second resin composition layer is bonded to the inner layer substrate by roll crimping or press crimping. It is preferable to laminate.

  The laminating process is preferably performed by roll pressing or press pressing. Among these, a vacuum laminating method of laminating under reduced pressure is more preferable. The laminating method may be a batch type or a continuous type.

The laminating treatment is generally performed in a pressure bonding range of 1 to 11 kgf / cm ² (9.8 × 10 ^{4 to} 107.9 × 10 ⁴ N / m ² ) and a pressure bonding temperature of 70 to 120 ° C. It is preferable that the time is in a range of 5 to 180 seconds and the air pressure is 20 mmHg (26.7 hPa) or less under reduced pressure.

Lamination can be performed using a commercially available vacuum laminator. Examples of the commercially available vacuum laminator include a vacuum pressure laminator manufactured by Meiki Seisakusho, a vacuum applicator manufactured by Nichigo Morton, and the like.
In addition, it is preferable to laminate through an elastic material such as heat-resistant rubber so that the resin sheet sufficiently follows the surface unevenness of the inner layer substrate (for example, the unevenness of the surface circuit of the inner layer circuit substrate).

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

  You may implement the process which heats and pressurizes the resin sheet laminated | stacked on the inner layer board | substrate after process (I), and is smoothed. The smoothing treatment is generally carried out by heating and pressurizing the resin sheet with a heated metal plate or metal roll under normal pressure (atmospheric pressure). The heating and pressurizing conditions can be the same conditions as the laminating conditions. The laminating process and the smoothing process may be continuously performed using a commercially available vacuum laminator.

  In step (II), the resin sheet is thermoset to form an insulating layer. Specifically, the adhesive layer (first resin composition layer, intermediate layer, and second resin composition layer) of the laminated resin sheets is thermally cured to form an insulating layer.

  The conditions for thermosetting are not particularly limited, and the conditions normally employed when forming the insulating layer of the printed wiring board may be used.

  For example, the thermosetting conditions of the resin sheet vary depending on the composition of each resin composition and intermediate layer forming composition constituting the adhesive layer, but the curing temperature is in the range of 120 ° C to 240 ° C (preferably 150 ° C to 210 ° C). , More preferably in the range of 170 ° C. to 190 ° C., and the curing time can be in the range of 5 minutes to 150 minutes (preferably 10 minutes to 120 minutes, more preferably 15 minutes to 90 minutes).

  Before the resin sheet is thermally cured, the adhesive layer may be preheated at a temperature lower than the curing temperature. For example, prior to thermosetting the resin sheet, the adhesive layer is kept at a temperature of 50 ° C. or higher and lower than 120 ° C. (preferably 60 ° C. or higher and 110 ° C. or lower, more preferably 70 ° C. or higher and 100 ° C. or lower) for 5 minutes or longer ( (Preferably 5 minutes to 150 minutes, more preferably 15 minutes to 120 minutes).

  In step (III), the support is removed. Thereby, the surface of the insulating layer is exposed. The support may be removed manually or mechanically using an automatic peeling device or the like. Further, when a metal foil is used as the support, it may be removed using a chemical.

  When manufacturing a printed wiring board, (IV) a step of drilling an insulating layer, (V) a step of roughening the insulating layer, (VI) a step of forming a conductor layer on the surface of the insulating layer Good. These steps (IV) to (VI) may be carried out according to various methods known to those skilled in the art used for the production of printed wiring boards. Note that the support is removed between step (II) and step (IV), between step (IV) and step (V), or between step (V) and step (VI). Good.

  Step (IV) is a step of making a hole in the insulating layer, whereby holes such as via holes and through holes can be formed in the insulating layer. For example, a hole can be formed in the insulating layer using a drill, a laser (a carbon dioxide laser, a YAG laser, or the like), plasma, or the like.

  Step (V) is a step of roughening the insulating layer. The procedure and conditions for the roughening treatment are not particularly limited, and known procedures and conditions that are usually used when forming an insulating layer of a printed wiring board can be employed. For example, the insulating layer can be roughened by performing a swelling treatment with a swelling liquid, a roughening treatment with an oxidizing agent, and a neutralization treatment with a neutralizing liquid in this order. Although it does not specifically limit as a swelling liquid, An alkaline solution, surfactant solution, etc. are mentioned, Preferably it is an alkaline solution, As this alkaline solution, a sodium hydroxide solution and a potassium hydroxide solution are more preferable. Examples of commercially available swelling liquids include Swelling Dip Securigans P and Swelling Dip Securigans SBU manufactured by Atotech Japan. Although the swelling process by a swelling liquid is not specifically limited, For example, it can perform by immersing an insulating layer for 1 minute-20 minutes in 30 degreeC-90 degreeC swelling liquid. Although it does not specifically limit as an oxidizing agent, For example, the alkaline permanganate solution which melt | dissolved potassium permanganate and sodium permanganate in the aqueous solution of sodium hydroxide is mentioned. The roughening treatment with an oxidizing agent such as an alkaline permanganic acid solution is preferably performed by immersing the insulating layer in an oxidizing agent solution heated to 60 to 80 ° C. for 10 to 30 minutes. The concentration of permanganate in the alkaline permanganate solution is preferably 5% by mass to 10% by mass. Examples of commercially available oxidizing agents include alkaline permanganate solutions such as concentrate compact CP and dosing solution securigans P manufactured by Atotech Japan. Moreover, as a neutralization liquid, acidic aqueous solution is preferable, As a commercial item, the reduction solution securigant P by Atotech Japan Co., Ltd. is mentioned, for example. The treatment with the neutralizing liquid can be performed by immersing the treated surface, which has been subjected to the roughening treatment with the oxidizing agent solution, in a neutralizing liquid at 30 ° C. to 80 ° C. for 5 to 30 minutes.

In one embodiment, the arithmetic average roughness Ra of the surface of the insulating layer after the roughening treatment is preferably 400 nm or less, more preferably 350 nm or less, further preferably 300 nm or less, 250 nm or less, 200 nm or less, 150 nm or less, or 100 nm or less. It is. The insulating layer formed using the resin sheet of the present invention exhibits excellent adhesion to the conductor layer even when Ra is small as described above. The lower limit of the Ra value is not particularly limited, but can usually be 0.5 nm or more, 1 nm or more, and the like. When there is a variation in Ra on the surface of the insulating layer after the roughening treatment, it is preferable that the maximum value of Ra (Ra _max ) be in the above range.

  The arithmetic average roughness Ra of the insulating layer surface can be measured using a non-contact type surface roughness meter. As a specific example of the non-contact type surface roughness meter, “WYKO NT3300” manufactured by Becoins Instruments is cited.

  Step (VI) 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 is one or more selected from the group consisting of gold, platinum, palladium, silver, copper, aluminum, cobalt, chromium, zinc, nickel, titanium, tungsten, iron, tin and indium. Contains metal. The conductor layer may be a single metal layer or an alloy layer. As the alloy layer, for example, an alloy of two or more metals selected from the above group (for example, nickel-chromium alloy, copper- A layer formed from a nickel alloy and a copper / titanium alloy). Among them, from the viewpoint of versatility of conductor layer formation, cost, ease of patterning, etc., single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver or copper, or nickel / chromium alloy, copper / An alloy layer of nickel alloy or copper / titanium alloy is preferable, and a single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver or copper, or an alloy layer of nickel / chromium alloy is more preferable, and a single layer of copper is preferable. A metal layer is more preferred.

  The conductor layer may have a single layer structure or a multilayer structure in which two or more single metal layers or alloy layers made of different types of metals or alloys are 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.

  Although the thickness of a conductor layer is based on the design of a desired printed wiring board, generally it is 3 micrometers-35 micrometers, Preferably it is 5 micrometers-30 micrometers.

  The conductor layer may be formed by plating. 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 additive method to form a conductor layer having a desired wiring pattern. Hereinafter, an example in which the conductor layer is formed by a semi-additive method will be described.

  First, a plating seed layer is formed on the surface of the insulating layer by electroless plating. Next, a mask pattern that exposes a part of the plating seed layer corresponding to a desired wiring pattern is formed on the formed plating seed layer. A metal layer is formed by electrolytic plating on the exposed plating seed layer, and then the mask pattern is removed. Thereafter, an unnecessary plating seed layer can be removed by etching or the like to form a conductor layer having a desired wiring pattern.

[Semiconductor device]
The semiconductor device of the present invention includes the printed wiring board of the present invention, and the semiconductor device can be manufactured using the printed wiring board of the present invention. By using the printed wiring board of the present invention, warpage of the printed wiring board in the component mounting process can be suppressed.

  In one embodiment, the amount of warpage of the printed wiring board in the component mounting step is preferably 30 μm or less, more preferably 29 μm or less, further preferably 28 μm or less, and even more preferably 27 μm or less. The lower limit of the warp amount is preferably as low as possible, and may be 0 μm or more. The warpage amount can be measured according to the procedure described in [Evaluation of warpage amount] described later.

  Examples of the semiconductor device include various semiconductor devices used for electrical products (for example, computers, mobile phones, digital cameras, and televisions) and vehicles (for example, motorcycles, automobiles, trains, ships, and aircrafts).

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. In the following description, “parts” and “%” mean “parts by mass” and “% by mass”, respectively, unless otherwise specified.

[Preparation Example 1: Preparation of coating solution 1]
6 parts naphthalene type epoxy resin (DIC Corporation “HP4032SS”, epoxy equivalent of about 144), bixylenol type epoxy resin (Mitsubishi Chemical Corporation “YX4000HK”, epoxy equivalent of about 185), 12 parts, biphenyl type epoxy resin (Nippon Kayaku Co., Ltd. "NC3000H", epoxy equivalent 288) 20 parts, and phenoxy resin (Mitsubishi Chemical Co., Ltd. "YX7553BH30", solid content 30 mass% cyclohexanone: methyl ethyl ketone (MEK) 1: 1 solution. ) 25 parts was heated and dissolved in a mixed solvent of 15 parts of solvent naphtha and 5 parts of cyclohexanone with stirring. After cooling to room temperature, 12 parts of a triazine skeleton-containing phenol novolac curing agent (hydroxyl equivalent 125, “LA-7054 manufactured by DIC Corporation, MEK solution with a solid content of 60%) 12 parts, naphthol curing agent ( 14 parts of “SN485” manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., MEK solution having a hydroxyl equivalent weight of 215 and a solid content of 60%, polyvinyl butyral resin (glass transition temperature of 105 ° C., “KS-1” manufactured by Sekisui Chemical Co., Ltd.) 12 parts of a 1: 1 mixed solution of ethanol and toluene with a solid content of 15%, 1 part of an amine curing accelerator (4-dimethylaminopyridine (DMAP), MEK solution with a solid content of 5% by mass), an imidazole curing accelerator (Mitsubishi Chemical Corporation “P200-H50”, 50 mass% solid content propylene glycol monomethyl ether solution) 2 parts, rubber particles (Aika Industry ( ) "AC3816N")) 5 parts of MEK 20 parts swollen at room temperature for 12 hours, spherical silica surface treated with aminosilane coupling agent ("KBM573" manufactured by Shin-Etsu Chemical Co., Ltd.) ) 50 parts of Admatechs'"SOC2", average particle size 0.5 μm, carbon amount per unit surface area 0.38 mg / m ² ) are mixed and dispersed uniformly with a high-speed rotary mixer, and then a cartridge filter (manufactured by ROKITETECHNO) A coating solution 1 was prepared by filtration through “SHP050”).

[Preparation Example 2: Preparation of coating solution 2]
10 parts of bisphenol AF type epoxy resin (Mitsubishi Chemical Corporation “YL7760”, epoxy equivalent 238), bisphenol type epoxy resin (“ZX1059” manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), epoxy equivalent of about 169, bisphenol A type and bisphenol F 5 parts of 1: 1 mixture of mold), 25 parts of biphenyl type epoxy resin (“NC3000H” manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent 288), and phenoxy resin (“YX7553BH30” manufactured by Mitsubishi Chemical Corporation), solid content 30 parts by mass of cyclohexanone: methyl ethyl ketone (MEK) 1: 1 solution) 6 parts, phenoxy resin (“YL7769BH30” manufactured by Mitsubishi Chemical Corporation, solid content of 30% by mass of cyclohexanone: methyl ethyl ketone (MEK) 1: 1 solution) 20 parts, 20 parts MEK and 5 parts cyclohexanone It was dissolved by heating with stirring in a mixed solvent. After cooling to room temperature, 30 parts of an active ester curing agent (“HPC8000-65T” manufactured by DIC Corporation, active group equivalent of about 223, 65% by weight of a non-volatile component in toluene), amine curing accelerator (4-dimethylaminopyridine (DMAP), MEK solution having a solid content of 5% by mass) 4 parts, imidazole curing accelerator (1-benzyl-2-phenylimidazole (1B2PZ), MEK solution having a solid content of 5% by mass) 3 Part, spherical silica surface treated with phenyltrimethoxysilane (“KBM103” manufactured by Shin-Etsu Chemical Co., Ltd.) (“UFP-30” manufactured by Denki Kagaku Kogyo Co., Ltd.), average particle size 0.1 μm, per unit surface area After mixing 45 parts of carbon (0.22 mg / m ² ) and evenly dispersing with a high-speed rotary mixer, cartridge filter (ROKITETECHNO) A coating solution 2 was prepared by filtration through “SHP030”.

[Preparation Example 3: Preparation of coating solution 3]
5 parts of cyclohexanedimethanol type epoxy resin (“ZX1658GS” manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., epoxy equivalent of about 135), 5 parts of naphthalene type epoxy resin (“HP4032SS” manufactured by DIC Corporation, about 144 equivalent of epoxy), naphthalene type 5 parts of epoxy resin (“DIC-4710” manufactured by DIC Corporation, epoxy equivalent of about 170), 5 parts of bixylenol type epoxy resin (“YX4000HK” manufactured by Mitsubishi Chemical Corporation, about 185 epoxy equivalent), biphenyl type epoxy resin (Nippon Kayaku Co., Ltd. "NC3000H", epoxy equivalent 288) 10 parts, and phenoxy resin (Mitsubishi Chemical Corporation "YX7553BH30", solid content 30 mass% cyclohexanone: methyl ethyl ketone (MEK) 1: 1 solution ) 10 parts, 20 parts solvent naphtha and cyclohexa In a mixed solvent of emissions 5 parts were dissolved by heating with stirring. After cooling to room temperature, 12 parts of a triazine skeleton-containing phenol novolac curing agent (hydroxyl equivalent: 125, “LA7054” manufactured by DIC Corporation, MEK solution with a solid content of 60%), naphthol curing agent (DIC ( "EXB-9500" manufactured by Co., Ltd., 12 parts of MEK solution having a hydroxyl equivalent weight of 190 and a solid content of 50%, 1 part of an amine curing accelerator (4-dimethylaminopyridine (DMAP), MEK solution having a solid content of 5% by mass) , Flame retardant (“HCA-HQ” manufactured by Sanko Co., Ltd., 10- (2,5-dihydroxyphenyl) -10-hydro-9-oxa-10-phosphophenanthrene-10-oxide, average particle size 2 μm ) 3 parts, 2 parts of rubber particles (“AC3816N” manufactured by Aika Kogyo Co., Ltd.) in 10 parts of MEK for 12 hours at room temperature, aminosilane coupling Grayed agent (Shin-Etsu Chemical Co., Ltd., "KBM573") surface-treated with spherical silica (Co. Admatechs Co. "SOC2", average particle size 0.5 [mu] m, the carbon amount 0.38 mg / m per unit surface area ² ) 150 parts were mixed and dispersed uniformly with a high-speed rotary mixer, and then filtered with a cartridge filter ("SHP050" manufactured by ROKITECHNO) to prepare coating solution 3.

[Preparation Example 4: Preparation of coating solution 4]
5 parts of dicyclopentadiene dimethanol type epoxy resin ("EP-4088L" manufactured by ADEKA, epoxy equivalent of about 165), 12 parts of bisphenol AF type epoxy resin ("YL7760" manufactured by Mitsubishi Chemical Corporation, epoxy equivalent of 238) 5 parts of bixylenol type epoxy resin (“YX4000HK” manufactured by Mitsubishi Chemical Corporation, epoxy equivalent of about 185), 24 parts of naphthalene type epoxy resin (“ESN475V” manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., 330 equivalents of epoxy), and phenoxy Heat and dissolve in a mixed solvent of 10 parts resin (Mitsubishi Chemical Corporation "YX7553BH30", solid solution 30% by weight cyclohexanone: methyl ethyl ketone (MEK) 1: 1 solution), 25 parts solvent naphtha and 5 parts cyclohexanone with stirring. I let you. After cooling to room temperature, there are 12 parts of a triazine skeleton-containing cresol novolac curing agent (hydroxyl equivalent 151, “LA301850P” manufactured by DIC Corporation, 2-methoxypropanol solution with a solid content of 50%), active ester curing Agent (DIC Corporation "HPC-8000-65T", active group equivalent about 223, non-volatile component 65% by weight toluene solution) 12 parts, imidazole curing accelerator (1-benzyl-2-phenylimidazole (1B2PZ) 4 parts of MEK solution having a solid content of 5% by mass, spherical silica surface-treated with an aminosilane coupling agent (“KBM573” manufactured by Shin-Etsu Chemical Co., Ltd.) (“SOC1” manufactured by Admatechs Co., Ltd.), average particle 150 parts of diameter 0.25 μm, carbon amount per unit surface area 0.36 mg / m ² ), mixed at high speed Then, the mixture was filtered with a cartridge filter (“SHP030” manufactured by ROKITECHNO) to prepare a coating solution 4.

[Preparation Example 5: Preparation of coating solution 5]
Spherical silica surface-treated with an aminosilane coupling agent (“KBM573” manufactured by Shin-Etsu Chemical Co., Ltd.) (“SOC2” manufactured by Admatechs Co., Ltd.), an average particle size of 0.5 μm, and an amount of carbon per unit surface area of 0. 1 part of cyclohexanone: methyl ethyl ketone (MEK) having a solid content of 40% by weight, 300 parts of a slurry solution (silica content 70% by weight) in which 38 mg / m ² ) is dispersed in MEK, phenoxy resin (“YX7180BH40” manufactured by Mitsubishi Chemical Corporation) : 1 solution, Tg: 15 ° C) 56 parts, imidazole curing accelerator ("P200-H50" manufactured by Mitsubishi Chemical Corporation, propylene glycol monomethyl ether solution having a solid content of 50% by mass), and 50 parts of MEK After adding and uniformly dispersing with a high-speed rotating mixer, a cartridge filter ("S manufactured by ROKITECHNO" P050 ") and filtered in, to prepare a coating solution 5.

[Preparation Example 6: Preparation of coating solution 6]
200 parts of quartz chopped strand (“SQCBC-02-3” manufactured by Shin-Etsu Quartz Co., Ltd., average filament diameter of 4 μm, chop length of about 30 μm), long chain epoxy silane coupling agent (“KBM manufactured by Shin-Etsu Chemical Co., Ltd.) -4803 "), 2 parts, naphthalene type epoxy resin (DIC Corporation" HP4032SS ", epoxy equivalent of 144, Tg: 159 ° C) 12 parts, phenoxy resin (Mitsubishi Chemical Corporation" YX7553BH30 ", solid content 30 40 parts by weight of cyclohexanone: 1: 1 solution of methyl ethyl ketone (MEK), active ester curing agent (“HPC-8000-65T” manufactured by DIC Corporation, active group equivalent of about 223, non-volatile component of 65% by weight of toluene Solution) 28 parts, amine curing accelerator (4-dimethylaminopyridine (DMAP), solid content 5 mass% 10 parts of MEK solution and 100 parts of MEK were added and dispersed uniformly with a high-speed rotary mixer to prepare coating solution 6.

[Preparation Example 7: Preparation of coating solution 7]
Spherical silica surface-treated with an aminosilane coupling agent (“KBM573” manufactured by Shin-Etsu Chemical Co., Ltd.) (“SOC2” manufactured by Admatechs Co., Ltd.), an average particle size of 0.5 μm, and an amount of carbon per unit surface area of 0. 1 part of cyclohexanone: methyl ethyl ketone (MEK) having a solid content of 40% by mass, 120 parts of a slurry solution (silica content of 70% by mass) in which 38 mg / m ² ) is dispersed in MEK, phenoxy resin (“YX7180BH40” manufactured by Mitsubishi Chemical Corporation) : 1 solution Tg: 15 ° C.) 56 parts, 3.5 parts of imidazole curing accelerator (“P200-H50” manufactured by Mitsubishi Chemical Corporation, propylene glycol monomethyl ether solution with a solid content of 50% by mass) and 50 parts of MEK are added. And then uniformly dispersed with a high-speed rotating mixer, a cartridge filter (“SHITECHNO” SH And filtered through a 050 "), and the coating liquid 7 was prepared.

[Preparation Example 8: Preparation of coating solution 8]
Colloidal silica (“MEK-ST-UP” manufactured by Nissan Chemical Industries, Ltd., MEK solution containing 20% by mass of chain silica) was prepared as the coating solution 8.

[Example 1: Production of resin sheet 1]
As a support, a PET film (“Lumirror T6AM” manufactured by Toray Industries, Inc., thickness 38 μm, softening point 130 ° C.) subjected to release treatment with an alkyd resin mold release agent (“AL-5” manufactured by Lintec Corporation) Prepared.

  On the support, using a die coater, the coating liquid 1 is applied and applied so that the target thickness after drying is 3 μm, and dried at 70 ° C. to 120 ° C. (average 95 ° C.) for 4 minutes. The resin composition layer was formed.

  Next, an intermediate layer and a second resin composition layer were sequentially formed on the first resin composition layer using a tandem coating method. Specifically, the coating liquid 8 is applied onto the first resin composition layer using a die coater, applied so that the target thickness after drying is 2 μm, and preliminarily dried at 90 ° C. for 0.6 minutes. After that, the coating liquid 3 is applied onto the intermediate layer using a die coater, applied so that the target thickness after drying is 20 μm, and dried at 80 ° C. to 115 ° C. (average 100 ° C.) for 3 minutes, Each layer was formed. Next, a polypropylene film (“Alphan MA-411” manufactured by Oji Specialty Paper Co., Ltd., thickness 15 μm) is used as a protective film on the surface of the second resin composition layer that is not bonded to the intermediate layer. The rough surface was laminated so as to be joined to the second resin composition layer. Thereby, it consists of the order of a support body, the 1st resin composition layer (from the coating liquid 1), the intermediate layer (from the coating liquid 8), the second resin composition layer (from the coating liquid 3), and the protective film. A resin sheet 1 was obtained. In addition, the target thickness after application | coating of a coating liquid and drying means the thickness at the time of apply | coating a coating liquid and drying as it is.

[Example 2: Production of resin sheet 2]
In the same manner as in Example 1, a first resin composition layer was formed on the support.

  By the simultaneous coating method, an intermediate layer and a second resin composition layer were sequentially formed on the first resin composition layer. Specifically, on the first resin composition layer, using a two-layer slit die coater, the application liquid 5 is applied at the same time as the target thickness after application and drying is 6 μm, and at the same time, the application liquid 3 is applied. The coating liquid 3 was applied onto the coating liquid 5 so that the target thickness after drying was 16 μm. Each layer was formed by drying at 70 ° C. to 115 ° C. (average 95 ° C.) for 4 minutes. Next, in the same manner as in Example 1, a protective film was laminated on the surface of the second resin composition layer that was not joined to the intermediate layer. Thus, the order of the support, the first resin composition layer (derived from the coating liquid 1), the intermediate layer (derived from the coating liquid 5), the second resin composition layer (derived from the coating liquid 3), and the protective film. The resin sheet 2 consisting of was obtained.

[Example 3: Production of resin sheet 3]
Resin sheet 3 was produced by the following procedure by tandem coating and simultaneous coating. A roll-shaped PET film is installed in the coating machine, unwinded, and a coating liquid 2 is applied so that the target thickness after coating and drying is 4 μm using a die coater on the release surface of the support. After coating and pre-drying at 90 ° C. for 0.8 minutes, using a two-layer slit die coater, the coating solution 6 is applied so that the target thickness after coating and drying is 10 μm. The coating solution 4 was applied so that the target thickness after coating and drying was 16 μm. Each layer was formed by drying at 80 ° C. to 115 ° C. (average 100 ° C.) for 4 minutes. Next, in the same manner as in Example 1, a protective film was laminated on the surface of the second resin composition layer that was not joined to the intermediate layer. Thus, the order of the support, the first resin composition layer (derived from the coating liquid 2), the intermediate layer (derived from the coating liquid 6), the second resin composition layer (derived from the coating liquid 4), and the protective film. The resin sheet 3 consisting of was obtained.

[Comparative Example 1: Production of resin sheet 4]
In the same manner as in Example 1, a first resin composition layer was formed on the support.

  On the 1st resin composition layer, the coating liquid 3 was apply | coated using the die-coater, and it apply | coated so that the target thickness after drying might be set to 22 micrometers. It was dried at 70 ° C. to 115 ° C. (average 95 ° C.) for 4 minutes to form a second resin composition layer. Next, in the same manner as in Example 1, a protective film was laminated on the second resin composition layer, and the support, the first resin composition layer (derived from the coating solution 1), and the second resin composition layer (coated). The resin sheet 4 which consists of the order of the liquid 3) and a protective film was obtained.

[Comparative Example 2: Production of resin sheet 5]
Resin sheet 5 was produced by tandem coating according to the following procedure. A PET film (“Lumirror T6AM” manufactured by Toray Industries, Inc., thickness 38 μm, softening point 130 ° C.) that has been subjected to release treatment in a roll form is placed on the coating machine, and unrolled to the release surface of the support. Apply the coating liquid 2 using a die coater, apply so that the target thickness after drying is 4 μm, pre-dry at 90 ° C. for 0.8 minutes, and then apply the coating liquid 4 using a die coater. The film was applied so that the target thickness after drying was 26 μm. Each resin composition layer was formed by drying at 80 ° C. to 115 ° C. (average 100 ° C.) for 4 minutes. Next, in the same manner as in Example 1, a protective film was laminated on the second resin composition layer, and the support, the first resin composition layer (derived from the coating solution 2), and the second resin composition layer (coated). The resin sheet 5 which consists of the order of the liquid 4) and a protective film was obtained.

[Comparative Example 3: Production of resin sheet 6]
In Example 2, a resin sheet 6 was obtained in the same manner as in Example 2 except that the coating solution 5 was changed to the coating solution 7.

[Measurement of minimum melt viscosity]
A second resin composition (coating solution 3 or 4) was applied as a single layer from a support on a PET film under the same conditions as in each example and each comparative example, and a measurement sample was prepared. Using a dynamic viscoelasticity measuring apparatus ("Rheosol-G3000" manufactured by UBM Co., Ltd.) and using a parallel plate with a diameter of 18 mm for 1 g of the sample resin composition, a starting temperature of 60C to 200C The temperature is raised at a rate of 5 ° C./minute until the measurement temperature interval is 2.5 ° C., the vibration frequency is 1 Hz, the strain is 1 deg, the dynamic viscoelastic modulus is measured, and the minimum melt viscosity (poise) is measured. did.

[Measurement of thickness of each layer of resin sheet]
The protective film was peeled off from the resin sheet (200 mm square) produced in each Example and each Comparative Example. With the second resin composition layer as the top surface, the resin sheet is placed on a glass cloth base epoxy resin double-sided copper-clad laminate (0.7 mm thickness, “R5715ES” manufactured by Matsushita Electric Works Co., Ltd.) having a size of 255 mm × 255 mm. The four sides of the resin sheet were fixed with polyimide adhesive tape (width 10 mm), 30 minutes at 100 ° C. (after being put into an oven at 100 ° C.), and then 30 minutes at 175 ° C. (after being transferred to an oven at 175 ° C.). And heat cured. Thereafter, the substrate was taken out in a room temperature atmosphere.

  The heat-cured resin sheet was subjected to cross-sectional observation using a FIB-SEM composite apparatus (“SMI3050SE” manufactured by SII Nanotechnology Co., Ltd.). Specifically, the cross section in the direction perpendicular to the surface of the resin sheet was cut out by FIB (focused ion beam), and a cross-sectional SEM image (observation width 30 μm, observation magnification 9,000 times) was obtained. For each sample, five cross-sectional SEM images selected at random were obtained, the thickness of each layer was shown as an average value, and this value was taken as the thickness of each layer.

[Measurement of average linear thermal expansion coefficient of cured adhesive layer]
The untreated surface of the release PET film (Lintec Co., Ltd. “501010”, thickness 38 μm, 240 mm square) is a glass cloth base epoxy resin double-sided copper-clad laminate (Matsushita Electric Works “R5715ES”, thickness) 0.7 mm, 255 mm square) was placed on a glass cloth base epoxy resin double-sided copper-clad laminate, and the four sides of the release film were fixed with polyimide adhesive tape (width 10 mm).

  Each resin sheet (200 mm square) produced in the examples and comparative examples was prepared by using a batch type vacuum press laminator (Nichigo-Morton Co., Ltd., 2-stage buildup laminator CVP700), and the second resin composition layer was Lamination was performed at the center so as to contact the release surface of the release PET film. The laminating process was carried out by reducing the pressure for 30 seconds to a pressure of 13 hPa or less and then pressing the film at 100 ° C. and a pressure of 0.74 MPa for 30 seconds.

  Then, it was heat-cured at 100 ° C. (after being put into a 100 ° C. oven) for 30 minutes, and then at 175 ° C. (after being transferred to the 175 ° C. oven) for 30 minutes. Thereafter, the substrate was taken out in a room temperature atmosphere and the support of the resin sheet was peeled off, and then the resin composition layer was further thermally cured at 190 ° C. for 90 minutes.

  After thermosetting, the polyimide adhesive tape was peeled off, and the laminated resin sheet was removed from the glass cloth base epoxy resin double-sided copper-clad laminate. Further, the release PET film was peeled from the laminated resin sheet to obtain a sheet-like cured product. The obtained cured product was cut into a test piece having a width of 5 mm and a length of 15 mm, and thermomechanical analysis was performed by a tensile load method using a thermomechanical analyzer (“Thermo Plus TMA8310” manufactured by Rigaku Corporation). It was. Specifically, after the test piece was mounted on the thermomechanical analyzer, the test piece was measured twice continuously under the measurement conditions of a load of 1 g and a heating rate of 5 ° C./min. In the second measurement, the average linear thermal expansion coefficient in the plane direction (α1; ppm / ° C.) in the range from 30 ° C. to 150 ° C. and the average linear thermal expansion coefficient in the plane direction in the range from 150 ° C. to 240 ° C. (Α2; ppm / ° C.) was calculated.

[Evaluation of warpage]
<Preparation of substrate for warpage evaluation>
(1) Preparation of inner layer substrate As an inner layer substrate, an unclad plate (thickness 100 μm, manufactured by Mitsubishi Gas Chemical Co., Ltd. “HL832NSF-LCA”) from which all the double-sided copper foils of the glass cloth base epoxy resin double-sided copper-clad laminate were removed. ) Was prepared.

(2) Lamination of resin sheet Each resin sheet produced in Examples and Comparative Examples was peeled off using a batch type vacuum pressure laminator (Nichigo-Morton Co., Ltd. 2-stage buildup laminator CVP700). It laminated | stacked on both surfaces of the inner layer board | substrate so that the 2nd resin composition layer might contact | connect an inner layer board | substrate. Lamination was performed by reducing the pressure for 30 seconds to a pressure of 13 hPa or less, and then pressure bonding at 110 ° C. and a pressure of 0.74 MPa for 30 seconds. Next, the laminated resin film was smoothed by hot pressing at 110 ° C. and a pressure of 0.5 MPa for 60 seconds under atmospheric pressure.

(3) Curing of resin composition layer After laminating the resin sheet, heat curing is performed at 100 ° C. (after being put into an oven at 100 ° C.) for 30 minutes, and then at 175 ° C. (after being transferred to an oven at 175 ° C.) for 30 minutes. I let you. Thereafter, the substrate was taken out in a room temperature atmosphere, the support was peeled off, and the adhesive layer was further thermally cured at 190 ° C. for 90 minutes to form an insulating layer. The obtained substrate was designated as “evaluation substrate A”.

(4) Measurement of warpage amount After cutting the evaluation board A into 45 mm square pieces (n = 5), a reflow apparatus (“HAS-6116” manufactured by Nippon Antom Co., Ltd.) that reproduces the solder reflow temperature at a peak temperature of 260 ° C. )) (Reflow temperature profile conforms to IPC / JEDEC J-STD-020C). Next, using a shadow moire device (“Thermoire AXP” manufactured by Akrometrix), the lower surface of the substrate is heated with a reflow temperature profile conforming to IPC / JEDEC J-STD-020C (peak temperature 260 ° C.), and 10 mm in the center of the substrate. The corner displacement was measured.

  From the said table | surface, the resin sheet of Examples 1-3 has a small average linear thermal expansion coefficient of 150-240 degreeC of the hardened | cured material of an adhesive layer, and when it applies to a printed wiring board, it contributes to reduction of the curvature in a high temperature environment. Confirmed to do.

  On the other hand, the resin sheet of Comparative Examples 1 and 2 having no intermediate layer, and the resin sheet of Comparative Example 3 in which the content of the inorganic filler in the intermediate layer is less than 80% by mass are more warped than Examples 1-3. I understand that there are many.

Claims (21)

A resin sheet having a support and an adhesive layer,
The adhesive layer includes a first resin composition layer provided on the support,
An intermediate layer provided on the first resin composition layer;
A second resin composition layer provided on the intermediate layer,
The content of the inorganic filler in the intermediate layer is, when the total of the nonvolatile components of the intermediate layer is 100 mass% state, and are more than 80 wt%,
The content (mass%) of the inorganic filler in the first resin composition layer is A, the content (mass%) of the inorganic filler in the intermediate layer is B, and the inorganic content in the second resin composition layer When the filler content (% by mass) is C, A, B, and C satisfy the relationship of A <C <B,
The difference (C−A) between the content (mass%) A of the inorganic filler in the first resin composition layer and the content (mass%) C of the inorganic filler in the second resin composition layer, Ru der 10% by weight to 80% by weight, the resin sheet.   The resin sheet according to claim 1, wherein the intermediate layer has a thickness of 1 to 20 μm.   The resin sheet according to claim 1 or 2, wherein the intermediate layer has a thickness of 1 to 15 µm.   The resin sheet according to any one of claims 1 to 3, wherein the thickness of the intermediate layer is 5% or more of the total thickness of the adhesive layer.   The resin sheet according to any one of claims 1 to 4, wherein the thickness of the intermediate layer is 20% or more of the total thickness of the adhesive layer.   The resin sheet according to any one of claims 1 to 5, wherein the inorganic filler is silica or glass fiber.   The resin sheet according to any one of claims 1 to 6, wherein the inorganic filler is colloidal silica, spherical silica, or glass fiber.   The resin sheet according to any one of claims 1 to 7, wherein the inorganic filler is colloidal silica, spherical silica having an average particle diameter of 10 µm or less, or glass fiber having an average filament diameter of 10 µm or less. The resin sheet according to any one of claims 1 to 8 , wherein the intermediate layer contains a phenoxy resin. The resin sheet according to any one of claims 1 to 9 , wherein the first resin composition layer has a thickness of 0.3 to 10 µm. The resin sheet according to any one of claims 1 to 10 , wherein the first resin composition layer is a resin composition layer for plating formation. The resin sheet according to any one of claims 1 to 11, wherein a thickness of the second resin composition layer is 3 to 200 µm. The thickness of the second resin composition layer is a 3～40Myuemu, the resin sheet according to any one of claims 1 to 1 2. The second resin composition layer contains 80% by mass or less of an inorganic filler having an average particle size of 1 μm or less when the total amount of nonvolatile components in the second resin composition layer is 100% by mass. The resin sheet according to any one of 1 to 3 . Minimum melt viscosity of the second resin composition layer is less than or equal 10000Poise, the resin sheet according to any one of claims 1 to 1 4. The resin sheet according to any one of claims 1 to 15 , wherein the second resin composition layer is a resin composition layer for circuit embedding. The resin sheet according to any one of claims 1 to 16 , wherein an average linear thermal expansion coefficient at 150 to 240 ° C of the cured product of the adhesive layer is 40 ppm / ° C or less. The average linear thermal expansion coefficient of 30 to 150 ° C. of the cured product of the adhesive layer is 20 ppm / ° C. or less, and average linear thermal expansion coefficient of 150 to 240 ° C. is not more than 40 ppm / ° C., more of claims 1 to 1 7 The resin sheet according to claim 1. Printed circuit board comprising an insulating layer formed by using the resin sheet according to any one of claims 1 to 1 8. The printed wiring board according to claim 19 , wherein a warpage amount in a component mounting process is 30 μm or less. The semiconductor device includes a printed wiring board according to claim 2 0.