JP2017179058A - Resin sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin sheet capable of imparting a thin insulating layer which suppresses warpage in reflow and is excellent in insulating performance.SOLUTION: There is provided a resin sheet having a resin composition layer containing (A) an epoxy resin, (B) a curing agent and (C) an inorganic filler, where when a nonvolatile component in the resin composition layer is 100 mass%, (C) the inorganic filler is 50 mass% or more, a lowest melting viscosity obtained by performing dynamic viscoelasticity measurement of the resin composition layer on conditions of vibration frequency of 1 Hz and distortion of 1 deg is 8,000 poise or more, and a lowest melting viscosity obtained by performing dynamic viscoelasticity measurement of the resin composition layer on conditions of vibration frequency of 1 Hz and distortion of 5 deg is 8,000 poise or less.SELECTED DRAWING: None

Description

  The present invention relates to a resin sheet. Furthermore, it is related with the printed wiring board containing the hardened | cured material of the resin composition layer of the said resin sheet, and a semiconductor device.

  In recent years, in order to achieve miniaturization of electronic devices, the printed wiring board has been further reduced in thickness, and the thickness of the inner layer substrate and the insulating layer tends to be further reduced. As a technique for reducing the thickness of an inner layer substrate or an insulating layer, for example, a thin film resin composition described in Patent Document 1 is known.

JP 2014-152309 A

  In Patent Document 1, the present inventors have found that when a thin film is applied to an insulating layer, the roughness tends to increase and the peel strength tends to decrease, and in order to solve these problems It has been proposed that the blending amount of the thermoplastic resin is a predetermined amount. However, in this document, no consideration is given to the insulation performance (hereinafter also referred to as “thin film insulation”) when the thickness of the insulating layer is reduced.

  When the insulating layer is a thin film, reflow warpage tends to occur. Therefore, it is conceivable to suppress reflow warpage by adding a large amount of an inorganic filler. However, when the content of the inorganic filler is increased, it becomes difficult to maintain the insulation performance, for example, current tends to flow through the interface where the inorganic filler particles adhere to each other, and the insulating layer is a thin film Therefore, the suppression of reflow warpage and the insulating property are in a trade-off relationship.

  The subject of this invention is providing the resin sheet which can provide the thin insulating layer which suppressed reflow curvature and was excellent in insulation performance.

As a result of intensive studies to solve the above problems, the present inventors have obtained the following knowledge.
In order to maintain the insulating property in the thin insulating layer, it is conceivable to improve the embedding property while improving the flatness of the insulating layer, but the minimum melt viscosity of the resin composition layer at a frequency of 1 Hz and a strain of 1 deg. By setting the value to 8000 poise or more, the movement of the resin composition layer in the thermosetting process or the like is suppressed, and the flatness is improved. On the other hand, by setting the minimum melt viscosity at a frequency of 1 Hz and a strain of 5 deg or less to 8000 poise, the embedding property is improved when pressure is applied in the laminating process.

  That is, the present inventors, in a resin sheet comprising a resin composition layer containing an epoxy resin, a curing agent, and an inorganic filler, the resin composition layer contains 50% by mass or more of an inorganic filler, and a resin composition. Reflow warpage is achieved by setting the minimum melt viscosity at a frequency of 1 Hz and a strain of 1 deg to 8000 poise or more for the physical layer and the minimum melt viscosity at a frequency of 1 Hz and a strain of 5 deg to 8000 poise or less. It was found that it is possible to provide an insulating layer that is suppressed and has excellent insulation performance (excellent in thin-film insulation) even though the thickness is small, and the present invention has been completed.

That is, the present invention includes the following contents.
[1] A resin sheet provided with a resin composition layer containing (A) an epoxy resin, (B) a curing agent, and (C) an inorganic filler, and 100% by mass of a non-volatile component in the resin composition layer (C) the inorganic filler is 50% by mass or more, and the resin composition layer has a minimum melt viscosity of 8000 poise or more at a frequency of 1 Hz and a strain of 1 deg. A resin sheet having a minimum melt viscosity of 8000 poise or less at a frequency of 1 Hz and a strain of 5 deg.
[2] The resin sheet according to [1], wherein the resin composition layer has a thickness of 15 μm or less.
[3] The resin sheet according to [1] or [2], wherein (A) the epoxy resin includes a liquid epoxy resin.
[4] The resin sheet according to any one of [1] to [3], wherein the average particle size of the inorganic filler (C) is 0.05 to 0.35 μm.
[5] The resin sheet according to any one of [1] to [4], which is for forming an insulating layer of a printed wiring board.
[6] A printed wiring board including a first conductor layer, a second conductor layer, and an insulating layer of 6 μm or less formed between the first conductor layer and the second conductor layer, The resin sheet according to any one of [1] to [5], which is used for forming an insulating layer.
[7] A printed wiring board including a first conductor layer, a second conductor layer, and an insulating layer of 6 μm or less formed between the first conductor layer and the second conductor layer, The insulating layer is a printed wiring board which is a cured product of the resin composition layer of the resin sheet according to any one of [1] to [6].
[8] A semiconductor device including the printed wiring board according to [7].

  ADVANTAGE OF THE INVENTION According to this invention, the resin sheet which can suppress the reflow curvature and can provide the thin insulating layer excellent in insulation performance can be provided.

FIG. 1 is a partial cross-sectional view schematically showing an example of a printed wiring board. FIG. 2 is a schematic view showing an example of a cross section of the component temporary bonding inner layer substrate.

  Hereinafter, a printed wiring board and a semiconductor device provided with the resin sheet of the present invention, and a cured product of the resin composition layer of the resin sheet will be described in detail.

  The resin sheet of the present invention includes a resin composition layer containing (A) an epoxy resin, (B) a curing agent, and (C) an inorganic filler, and the nonvolatile component in the resin composition layer is 100% by mass. In this case, (C) the inorganic filler is 50% by mass or more. In the present invention, the resin composition layer has a minimum melt viscosity of 8000 poise at a frequency of 1 Hz and a strain of 1 deg, and the resin composition layer has a minimum melt viscosity of 8000 at a frequency of 1 Hz and a strain of 5 deg. Below poise. In this specification, “minimum melt viscosity at a frequency of 1 Hz and a strain of 1 deg” may be referred to as “minimum melt viscosity at a strain of 1 deg” and “the minimum melt viscosity at a frequency of 1 Hz and a strain of 5 deg”. May be described as “minimum melt viscosity at 5 deg strain”.

  The resin composition layer includes (A) an epoxy resin, (B) a curing agent, and (C) an inorganic filler. The resin composition layer is formed of a resin composition. First, the resin composition which forms a resin composition layer is demonstrated.

[Resin composition]
The resin composition includes (A) an epoxy resin, (B) a curing agent, and (C) an inorganic filler. The resin composition may further contain additives such as a thermoplastic resin, a curing accelerator, a flame retardant, and an organic filler as necessary.

  Hereinafter, (A) epoxy resin, (B) curing agent, (C) inorganic filler and additive that can be used as the material of the resin composition will be described.

<(A) Epoxy resin>
The resin composition contains (A) an epoxy resin. (A) As an epoxy resin, for example, 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 Containing epoxy resins, cyclohexanedimethanol type epoxy resins, naphthylene ether type epoxy resin, trimethylol type epoxy resin, tetraphenyl ethane epoxy resin and the like. An epoxy resin may be used individually by 1 type, and may be used in combination of 2 or more type. The component (A) is preferably at least one selected from bisphenol A type epoxy resins, bisphenol F type epoxy resins, and biphenyl type epoxy resins.

  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. The epoxy resin contains a liquid epoxy resin (hereinafter referred to as “liquid epoxy resin”) at a temperature of 20 ° C. from the viewpoint of lowering the melt viscosity of 5 deg strain of the resin composition layer and improving the embedding property. Is preferred. Among them, a liquid epoxy resin having two or more epoxy groups in one molecule, a liquid epoxy resin having three or more epoxy groups in one molecule, and a solid epoxy resin at a temperature of 20 ° C. (hereinafter “solid state”). It is more preferable to include an “epoxy resin”. By using a liquid epoxy resin and a solid epoxy resin in combination as the epoxy resin, a resin composition layer having excellent flexibility can be obtained. Moreover, the breaking strength of the cured product of the resin composition layer is also improved.

  Liquid epoxy resins include bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol AF type epoxy resins, naphthalene type epoxy resins, glycidyl ester type epoxy resins, glycidyl amine type epoxy resins, phenol novolac type epoxy resins, and ester skeletons. Preferred are cycloaliphatic epoxy resins, cyclohexanedimethanol type epoxy resins, glycidylamine type epoxy resins, and epoxy resins having a butadiene structure. Glycidylamine type epoxy resins, bisphenol A type epoxy resins, bisphenol F type epoxy resins, 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, “828US”, “jER828EL” (bisphenol A) manufactured by Mitsubishi Chemical Corporation. Type epoxy resin), "jER807" (bisphenol F type epoxy resin), "jER152" (phenol novolac type epoxy resin), "YL7760" (bisphenol AF type epoxy resin), "630", "630LSD" (glycidylamine type epoxy) Resin), "ZX1059" (mixed product of bisphenol A type epoxy resin and bisphenol F type epoxy resin) manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., "YD-8125G" (bisphenol A type epoxy resin) manufactured by Nippon Steel & Sumikin Chemical Co., Ltd. , Nagase ChemteX "EX-721" (glycidyl ester type epoxy resin) manufactured by Co., Ltd., "Celoxide 2021P" (alicyclic epoxy resin having an ester skeleton), "PB-3600" (epoxy having a butadiene structure) manufactured by Daicel Corporation Resin), “ZX1658”, “ZX1658GS” (liquid 1,4-glycidylcyclohexane) manufactured by Nippon Steel Chemical Co., Ltd., “630LSD” (glycidylamine type epoxy resin) manufactured by Mitsubishi Chemical Corporation, and the like. . These may be used alone or in combination of two or more.

  Solid epoxy resins include naphthalene type tetrafunctional epoxy resin, cresol novolac type epoxy resin, dicyclopentadiene type epoxy resin, trisphenol type epoxy resin, naphthol type epoxy resin, biphenyl type epoxy resin, naphthylene ether type epoxy resin, Anthracene type epoxy resin, bisphenol A type epoxy resin, and tetraphenylethane type epoxy resin are preferable, and naphthalene type tetrafunctional epoxy resin, naphthol type epoxy resin, and biphenyl type epoxy resin are more preferable. Specific examples of the solid epoxy resin include “HP4032H” (naphthalene type epoxy resin), “HP-4700”, “HP-4710” (naphthalene type tetrafunctional epoxy resin), “N-690” manufactured by DIC Corporation. "(Cresol novolac type epoxy resin)", "N-695" (Cresol novolac type epoxy resin), "HP-7200", "HP-7200HH", "HP-7200H" (Dicyclopentadiene type epoxy resin), "EXA" -7311 "," EXA-7311-G3 "," EXA-7311-G4 "," EXA-7311-G4S "," HP6000 "(naphthylene ether type epoxy resin)," EPPN "manufactured by Nippon Kayaku Co., Ltd. -502H "(trisphenol type epoxy resin)," NC7000L "(naphthol novolak type) Poxy resin), “NC3000H”, “NC3000”, “NC3000L”, “NC3100” (biphenyl type epoxy resin), “ESN475V” (naphthalene type epoxy resin) manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., “ESN485” (naphthol novolak) Type epoxy resin), "YX4000H", "YL6121" (biphenyl type epoxy resin), "YX4000HK" (bixylenol type epoxy resin), "YX8800" (anthracene type epoxy resin), manufactured by Mitsubishi Chemical Corporation, Osaka Gas Chemical “PG-100”, “CG-500” manufactured by Mitsubishi Chemical Corporation, “YL7800” (fluorene type epoxy resin) manufactured by Mitsubishi Chemical Corporation, “jER1010” manufactured by Mitsubishi Chemical Corporation (solid bisphenol A type) Epoxy resin), "jER1031S" (Tetra Eniruetan epoxy resin) and the like. Among these, although it is solid by itself, it tends to be liquid when mixed with other components when preparing the resin composition, and the resin composition layer has a good embeddability by lowering the melt viscosity of 5 deg strain. Therefore, “YX4000HK” (bixylenol type epoxy resin) manufactured by Mitsubishi Chemical Corporation is preferable.

  The liquid epoxy resin is preferably an aromatic epoxy resin having two or more epoxy groups in one molecule and a liquid at a temperature of 20 ° C. The solid epoxy resin has three or more epoxy groups in one molecule. And an aromatic epoxy resin that is solid at a temperature of 20 ° C. is preferable. In addition, the aromatic epoxy resin as used in the field of this invention means the epoxy resin which has an aromatic ring structure in the molecule | numerator.

  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: 0.5 to 1:25 by mass ratio. preferable. By making the quantity ratio of the liquid epoxy resin and the solid epoxy resin within such a range, i) suitable adhesiveness is obtained when used in the form of a resin sheet, ii) when used in the form of a resin sheet Sufficient flexibility can be obtained, handling properties can be improved, and iii) a cured product having sufficient breaking strength can be obtained. From the viewpoint of the effects i) to iii), the quantitative ratio of the liquid epoxy resin to the solid epoxy resin (liquid epoxy resin: solid epoxy resin) is in the range of 1: 1.0 to 1:20 by mass ratio. Is more preferable, and the range of 1: 1.5 to 1:15 is even more preferable.

  The content of the epoxy resin in the resin composition is preferably 5% by mass or more, more preferably 9% by mass or more, and still more preferably 11% by mass from the viewpoint of obtaining an insulating layer having a low dielectric loss tangent and insulation reliability. That's it. Although the upper limit of content of an epoxy resin is not specifically limited as long as the effect of this invention is show | played, Preferably it is 50 mass% or less, More preferably, it is 40 mass% or less.

  In addition, in this invention, content of each component in a resin composition is a value when the non-volatile component in a resin composition is 100 mass% unless there is separate description.

  The epoxy equivalent of the epoxy resin is preferably 50 to 5000, more preferably 50 to 3000, still more preferably 80 to 2000, and even more preferably 110 to 1000. By being in this range, the crosslinked density of the cured product of the resin composition layer is sufficient, and an insulating layer having a small surface roughness can be provided. 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 resin composition includes (B) a curing agent. The curing agent is not particularly limited as long as it has a function of curing an epoxy resin. For example, a phenolic curing agent, a naphthol curing agent, an active ester curing agent, a benzoxazine curing agent, a cyanate ester Examples thereof include a curing agent and a carbodiimide curing agent. 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”, “SN-495V”, “SN375” manufactured by Nippon Steel & Sumikin Co., Ltd. ”,“ SN395 ”,“ TD-2090 ”,“ LA-7052 ”,“ LA-7054 ”,“ LA-1356 ”,“ LA-3018-50P ”,“ EXB-9500 ”manufactured by DIC Corporation, etc. Is mentioned.

  Although there is no restriction | limiting in particular as an active ester type hardening | curing agent, Generally 1 molecule of ester groups with high reaction activity, such as phenol ester, thiophenol ester, N-hydroxyamine ester, ester of a heterocyclic hydroxy compound, are carried out. A compound having two or more thereof 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-dicyclopentylene-phenylene.

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

  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” (phenol novolac type polyfunctional cyanate ester resin), “ULL-950S” (polyfunctional cyanate ester resin) manufactured by Lonza Japan Co., Ltd., “ BA230 "," BA230S75 "(a prepolymer in which a part or all of bisphenol A dicyanate is triazine-modified into a trimer) and the like.

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

  (B) As a component, it is preferable that it is 1 or more types selected from a phenol type hardening | curing agent, a naphthol type hardening | curing agent, an active ester type hardening | curing agent, and a cyanate ester type hardening | curing agent. Moreover, from the viewpoint that the melt viscosity with a strain of 5 deg can be lowered and the embedding property can be improved, an active ester curing agent is more preferable as the curing agent.

  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: 0.01 to 1: 2. 1: 0.015 to 1: 1.5 are more preferable, and 1: 0.02 to 1: 1 are 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 making the quantity ratio of an epoxy resin and a hardening | curing agent into such a range, the heat resistance of the hardened | cured material of a resin composition layer improves more.

  Although content of the hardening | curing agent in a 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. The lower limit is not particularly limited but is preferably 2% by mass or more.

<(C) Inorganic filler>
The resin composition includes (C) 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. Examples of the silica include amorphous silica, fused silica, crystalline silica, synthetic silica, and hollow silica. 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 diameter of the inorganic filler improves the thin film insulation when the inorganic filler is highly filled, and raises the minimum melt viscosity at a strain of 1 deg of the resin composition layer to enhance the flatness. Therefore, 0.35 μm or less is preferable, 0.32 μm or less is more preferable, 0.3 μm or less is more preferable, and 0.29 μm or less is even more preferable. From the viewpoint of improving dispersibility in the resin composition layer, the lower limit of the average particle diameter is preferably 0.05 μm or more, more preferably 0.06 μm or more, and further preferably 0.065 μm or more. Examples of commercially available inorganic fillers having such an average particle diameter include “UFP-30” and “UFP-40” manufactured by Denki Kagaku Kogyo Co., Ltd. and “SPH516-05” manufactured by Nippon Steel & Sumikin Materials Co., Ltd. Or 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 methyl ethyl ketone by ultrasonic waves can be preferably used. As a laser diffraction scattering type particle size distribution measuring apparatus, “SALD-2200” manufactured by Shimadzu Corporation can be used.

The specific surface area of the inorganic filler is preferably 45 m ² / g or less, more preferably 43 m ² / g or less, and still more preferably 41 m ² / g, from the viewpoint of lowering the minimum melt viscosity at a strain of 5 deg of the resin composition layer. It is as follows. The lower limit of the specific surface area is preferably 1 m ² / g or more, more preferably 2 m ² / g or more, and still more preferably 5 m ² / g or more, from the viewpoint of maintaining appropriate viscoelasticity of the resin composition layer. The specific surface area can be measured using, for example, a BET fully automatic specific surface area measuring apparatus (manufactured by Mountec, Macsorb HM-1210).

From the viewpoint of improving dispersibility in the resin composition layer, the true density of the inorganic filler is preferably 15 g / cm ³ or less, more preferably 10 g / cm ³ or less, and even more preferably 5 g / cm ³ or less. The lower limit of the true density is preferably 1 g / cm ³ or more, more preferably 1.5 g / cm ³ or more, and still more preferably 2.0 g / cm ³ or more. The true density can be measured using, for example, a micro-ultra pycnometer (manufactured by Cantachrome Instruments Japan, MUPY-21T).

  The inorganic filler is preferably surface-treated with at least one surface treatment agent of a silane coupling agent, an alkoxysilane compound, and an organosilazane compound from the viewpoint of improving moisture resistance and dispersibility. These may be oligomers. Examples of the surface treatment agent include aminosilane coupling agents, epoxysilane coupling agents, mercaptosilane coupling agents, silane coupling agents, organosilazane compounds, titanate coupling agents, and the like. 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). A surface treating agent may be used individually by 1 type, and may be used in combination of 2 or more types.

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, 0.15 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 suppressing the increase in melt viscosity of the resin varnish and 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 (filling amount) of the inorganic filler in the resin composition is 50% by mass or more when the nonvolatile component in the resin composition is 100% by mass. From the viewpoint of improving the thickness stability of the resin composition layer and suppressing reflow warpage, the content of the inorganic filler is preferably 55% by mass or more, and more preferably 60% by mass or more. The upper limit of the content of the inorganic filler in the resin composition is preferably 85% by mass or less, more preferably 80% by mass or less, from the viewpoint of improving thin film insulation.

<(D) Thermoplastic resin>
The resin sheet of the present invention may further contain (D) a thermoplastic resin. Accordingly, it is possible to easily adjust the flatness by increasing the melt viscosity with a strain of 1 deg.

  Examples of the thermoplastic resin include phenoxy resin, polyvinyl acetal resin, polyolefin resin, polybutadiene resin, polyimide resin, polyamideimide resin, polyetherimide resin, polysulfone resin, polyethersulfone resin, polyphenylene ether resin, polycarbonate resin, and polyether. Examples include ether ketone resins and polyester resins, and phenoxy resins are preferred. A thermoplastic resin may be used individually by 1 type, or may be used in combination of 2 or more type.

  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 calculated using a standard polystyrene calibration curve by measuring the column temperature at 40 ° C. using chloroform or the like as a mobile phase.

  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, and may be used in combination of 2 or more type. 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., "YX6954BH30", "YX7553", "YX7553BH30" manufactured by Mitsubishi Chemical Corporation, “YL7769BH30”, “YL6794”, “YL7213”, “YL7290”, “YL7482” and the like.

  Examples of the polyvinyl acetal resin include a polyvinyl formal resin and a polyvinyl butyral resin, and a polyvinyl butyral resin is preferable. Specific examples of the polyvinyl acetal resin include, for example, “Electrical butyral 4000-2”, “Electrical butyral 5000-A”, “Electrical butyral 6000-C”, and “Electrical butyral 6000-EP” manufactured by Denki Kagaku Kogyo Co., Ltd. , Sreck BH series, BX series (for example, BX-5Z), KS series (for example, KS-1), BL series, and BM series manufactured by Sekisui Chemical Co., Ltd.

  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 (polyimide described in JP-A-2006-37083), a polysiloxane skeleton. Examples thereof include modified polyimides such as containing polyimide (polyimides described in 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 “KS9100” and “KS9300” (polysiloxane skeleton-containing polyamideimide) 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.

  Specific examples of the polyphenylene ether resin include oligophenylene ether / styrene resins “OPE-2St1200” and “OPE-2St2200” manufactured by Mitsubishi Gas Chemical Co., Ltd., “NORYL SA90” manufactured by SABIC, and the like.

  As the thermoplastic resin, phenoxy resin, polyphenylene ether resin, and polyvinyl acetal resin are preferable. Accordingly, in a preferred embodiment, the thermoplastic resin includes one or more selected from the group consisting of a phenoxy resin, a polyphenylene ether resin, and a polyvinyl acetal resin.

  When the resin composition contains a thermoplastic resin, the content of the thermoplastic resin is preferably 0.5% by mass to 10% by mass, more preferably 0.6% by mass to 6% by mass, and still more preferably 0.8%. It is 7 mass%-5 mass%.

<(E) Curing accelerator>
The resin sheet of the present invention may further contain (E) a curing accelerator.

  Examples of the curing accelerator include a phosphorus-based curing accelerator, an amine-based curing accelerator, an imidazole-based curing accelerator, a guanidine-based curing accelerator, a metal-based curing accelerator, and the like. A curing accelerator, an imidazole curing accelerator, and a metal curing accelerator are preferable, and an amine curing accelerator, an imidazole curing accelerator, and a metal 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- Phenylimidazole is preferred.

  Commercially available products may be used as the imidazole curing accelerator, and examples thereof include “P200-H50” manufactured by Mitsubishi Chemical Corporation, “1B2PZ” manufactured by Shikoku Kasei Kogyo Co., Ltd., and the like.

  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.

  As a metal type hardening accelerator, the organometallic complex or organometallic salt of metals, such as cobalt, copper, zinc, iron, nickel, manganese, tin, is mentioned, for example. Specific examples of the organometallic complex include organic cobalt complexes such as cobalt (II) acetylacetonate and cobalt (III) acetylacetonate, organic copper complexes such as copper (II) acetylacetonate, and zinc (II) acetylacetonate. Organic zinc complexes such as iron (III) acetylacetonate, organic nickel complexes such as nickel (II) acetylacetonate, and organic manganese complexes such as manganese (II) acetylacetonate. Examples of the organic metal salt include zinc octylate, tin octylate, zinc naphthenate, cobalt naphthenate, tin stearate, and zinc stearate.

  Although content of the hardening accelerator in a resin composition is not specifically limited, 0.01 mass%-3 mass% are preferable when the non-volatile component of an epoxy resin and a hardening | curing agent is 100 mass%. By setting it as this range, it is possible to easily adjust the melt viscosity at a strain of 1 deg and 5 deg.

<(F) Flame retardant>
The resin sheet of the present invention may further contain (F) 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, for example, “HCA-HQ” manufactured by Sanko Co., Ltd., “PX-200” manufactured by Daihachi Chemical Industry Co., Ltd., and the like.

  When the resin composition contains a flame retardant, the content of the flame retardant is not particularly limited, but is preferably 0.5% by mass to 20% by mass, more preferably 0.5% by mass to 15% by mass, and still more preferably. 0.5 mass%-10 mass% are further more preferable.

<(G) Organic filler>
The resin composition may include (G) an organic filler. As the organic filler, any organic filler that can be used in forming the insulating layer of the printed wiring board may be used, and examples thereof include rubber particles, polyamide fine particles, and silicone particles.

  As the rubber particles, commercially available products may be used, and examples thereof include “EXL2655” manufactured by Dow Chemical Japan Co., Ltd., “AC3401N” and “AC3816N” manufactured by Aika Industry Co., Ltd.

  When the resin composition contains an organic filler, the content of the organic filler is preferably 0.1% by mass to 20% by mass, more preferably 0.2% by mass to 10% by mass, and still more preferably 0.8%. 3% by mass to 5% by mass, or 0.5% by mass to 3% by mass.

<(H) Optional additive>
The resin composition may further contain other additives as necessary. Examples of such other additives include organic metal compounds such as organic copper compounds, organic zinc compounds, and organic cobalt compounds, And resin additives such as thickeners, antifoaming agents, leveling agents, adhesion-imparting agents, and coloring agents.

  The resin sheet of the present invention suppresses reflow warpage and provides an insulating layer with excellent thin film insulation. Therefore, the resin sheet of the present invention can be suitably used as a resin sheet (for forming an insulating layer of a printed wiring board) for forming an insulating layer of a printed wiring board, and forms an interlayer insulating layer of the printed wiring board. Therefore, it can be used more suitably as a resin sheet (resin sheet for an interlayer insulating layer of a printed wiring board). Further, for example, in a printed wiring board including a first conductor layer, a second conductor layer, and an insulating layer provided between the first conductor layer and the second conductor layer, the resin of the present invention. By forming the insulating layer with a sheet, the insulating layer between the first and second conductor layers has a thickness of 6 μm or less (preferably 5.5 μm or less, more preferably 5 μm or less), and excellent insulation performance. be able to.

[Resin sheet]
The resin sheet of the present invention includes a resin composition layer, and the resin composition layer is formed from the resin composition.

  The thickness of the resin composition layer is preferably 15 μm or less, more preferably 12 μm or less, still more preferably 10 μm or less, and even more preferably 8 μm or less, from the viewpoint of reducing the thickness of the printed wiring board. Although the minimum of the thickness of a resin composition layer is not specifically limited, Usually, it may be 1 micrometer or more, 1.5 micrometers or more, 2 micrometers or more, etc.

  As one embodiment of the present invention, a resin sheet includes a support and a resin composition layer bonded on the support. Examples of the support include a film made of a plastic material, a metal foil, and a release paper, and a film made of a plastic material and a metal foil are preferable.

  When a film made of a plastic material is used as the support, examples of the plastic material include polyethylene terephthalate (hereinafter sometimes abbreviated as “PET”) and polyethylene naphthalate (hereinafter 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, corona treatment, and antistatic treatment on the surface to be bonded to the resin composition layer.

  Moreover, as a support body, you may use the support body with a release layer which has a release layer in the surface joined to a resin composition layer. 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., “Lumirror R80”, 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.

  The resin sheet is prepared by, for example, preparing a resin varnish in which a resin composition is dissolved in an organic solvent, applying the resin varnish on a support using a die coater or the like, and further drying to form a resin composition layer. Can be manufactured.

  Examples of the organic solvent include ketones such as acetone, methyl ethyl ketone (MEK) and cyclohexanone, acetates such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate and carbitol acetate, cellosolve and butyl carbitol, etc. Carbitols, aromatic hydrocarbons such as toluene and xylene, amide solvents such as dimethylformamide, dimethylacetamide (DMAc), and N-methylpyrrolidone. An organic solvent may be used individually by 1 type, and may be used in combination of 2 or more type.

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

  In the resin sheet, a protective film according to the support can be further laminated on the surface of the resin composition layer that is not bonded to the support (that is, the surface opposite to the support). Although the thickness of a protective film is not specifically limited, For example, they are 1 micrometer-40 micrometers. By laminating the protective film, it is possible to prevent dust and the like from being attached to the surface of the resin composition layer and scratches. The resin sheet can be stored in a roll. When the resin sheet has a protective film, it can be used by peeling off the protective film.

  The minimum melt viscosity of the resin composition layer at a strain of 1 deg is 8000 poise (800 Pa · s) or more from the viewpoint of improving the flatness by suppressing the movement of the resin layer in a thermosetting step or the like, and 8500 poise (850 Pa · 850 °). s) or more, preferably 9000 poise (900 Pa · s) or more, more preferably 10,000 poise (1000 Pa · s) or more. The upper limit of the minimum melt viscosity at a strain of 1 deg of the resin composition layer is preferably 20000 poise (2000 Pa · s) or less, more preferably 15000 poise (1500 Pa · s) or less, from the viewpoint of obtaining good wiring embedding properties. Preferably, it is 13000 poise (1300 Pa · s) or less.

  The lower limit value of the minimum melt viscosity at a strain of 5 deg of the resin composition layer is preferably 500 poise (50 Pa · s) or more from the viewpoint of suppressing the movement of the resin layer and improving the flatness in a thermosetting process or the like. 700 poise (70 Pa · s) or more, more preferably 900 poise (90 Pa · s) or more. The upper limit of the minimum melt viscosity at a strain of 5 deg of the resin composition layer is 8000 poise (800 Pa · s) or less and preferably 7000 poise (700 Pa · s) or less from the viewpoint of obtaining good wiring embedding properties. 6000 poise (600 Pa · s) or less, more preferably 5000 poise (500 Pa · s) or less.

  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. The “minimum melt viscosity at a strain of 1 deg” is the “minimum melt viscosity obtained by performing dynamic viscoelasticity measurement under the conditions of a frequency of 1 Hz and a strain of 1 deg”, and the “minimum melt viscosity at a strain of 5 deg” is “Minimum melt viscosity obtained by performing dynamic viscoelasticity measurement under conditions of a frequency of 1 Hz and a strain of 5 deg”.

[Hardened product]
The thermosetting conditions of the resin composition layer of the resin sheet of the present invention are not particularly limited, and for example, conditions usually employed when forming an insulating layer of a printed wiring board described later may be used. In addition, the resin composition layer may be preheated before thermosetting, and the heating under the thermosetting conditions may be performed a plurality of times including preheating. As an example of heat curing conditions, first, the resin composition layer is thermally cured at 100 ° C. for 30 minutes, then at 180 ° C. for 30 minutes, and further at 200 ° C. for 90 minutes.

  Cured product of the resin composition layer of the resin sheet of the present invention (for example, a cured product obtained by thermally curing the resin composition layer at 100 ° C. for 30 minutes, then at 180 ° C. for 30 minutes, and further at 200 ° C. for 90 minutes) The average linear thermal expansion coefficient (CTE) shows a good average linear thermal expansion coefficient at 25 to 150 ° C. That is, an insulating layer exhibiting a good average linear thermal expansion coefficient is provided. The average linear thermal expansion coefficient at 25 ° C. to 150 ° C. is preferably 30 ppm / ° C. or less, more preferably 28 ppm / ° C. or less, further preferably 26 ppm / ° C., from the viewpoint that the amount of reflow warpage of the cured product can be reduced. It is as follows. Although it does not specifically limit about a minimum, it is 0.1 ppm / degrees C or more. The measuring method of an average linear thermal expansion coefficient can be measured in accordance with the method described later in <Measurement of average linear thermal expansion coefficient (CTE) of cured product of resin sheet>.

A cured product obtained by thermally curing the resin composition layer of the resin sheet of the present invention (for example, a cured product obtained by thermally curing the resin composition layer at 100 ° C. for 30 minutes and then at 180 ° C. for 30 minutes), The insulation resistance value after a lapse of 200 hours under a 130 ° C, 85RH%, 3.3V applied environment shows a good result. That is, an insulating layer exhibiting a good insulation resistance value is provided. The upper limit of the insulation resistance value is preferably 10 ¹² Ω or less, more preferably 10 ¹¹ Ω or less, and further preferably 10 ¹⁰ Ω or less. The lower limit is preferably 10 ⁷ Ω or more, more preferably 10 ⁸ Ω or more. The insulation resistance value can be measured according to the method described in <Evaluation of insulation reliability> described later.

  The present invention provides a cured product of a resin composition layer having a minimum melt viscosity of 8000 poise or more at a frequency of 1 Hz and a strain of 1 deg, and a minimum melt viscosity of 8000 poise or less at a frequency of 1 Hz and a strain of 5 deg. Is also included. The cured product of the present invention has the same configuration as the cured product of the resin composition layer of the resin sheet of the present invention. The curing conditions for the resin composition layer for forming the cured product are the same as the curing conditions for the resin sheet of the present invention. Preferred average linear thermal expansion coefficient in the cured product of the present invention (for example, a cured product obtained by thermally curing a resin composition layer at 100 ° C. for 30 minutes, then at 180 ° C. for 30 minutes, and further at 200 ° C. for 90 minutes) The range is the same as that of the cured resin sheet described above. The preferable range of the insulation resistance value in the cured product of the present invention is the same as that of the cured product of the resin sheet described above.

[Printed wiring board, printed wiring board manufacturing method]
The printed wiring board of the present invention includes an insulating layer, a first conductor layer, and a second conductor layer formed from a cured product of the resin composition layer of the resin sheet of the present invention. The printed wiring board of the present invention may be provided with the cured product of the present invention as an insulating layer. The insulating layer is provided between the first conductor layer and the second conductor layer, and insulates the first conductor layer and the second conductor layer (the conductor layer is also referred to as a wiring layer). . Since the insulating layer formed from the cured product of the resin composition layer of the resin sheet of the present invention is excellent in thin film insulating properties, it is insulative even if the thickness of the insulating layer between the first and second conductor layers is 6 μm or less. Excellent.

The thickness of the insulating layer between the first and second conductor layers is preferably 6 μm or less, more preferably 5.5 μm or less, and even more preferably 5 μm or less. The lower limit is not particularly limited, but may be 0.1 μm or more. The thickness of the insulating layer between the first and second conductor layers is the insulation between the main surface 51 of the first conductor layer 5 and the main surface 61 of the second conductor layer 6 as shown in FIG. This refers to the thickness t1 of the layer 7. The first and second conductor layers are conductor layers adjacent to each other with an insulating layer interposed therebetween, and the main surface 51 and the main surface 61 face each other. The thickness of the insulating layer between the first and second conductor layers can be measured according to the method described in <Evaluation of insulation reliability, measurement of the thickness of the insulating layer between conductor layers> described later.
The total thickness t2 of the insulating layer is preferably 20 μm or less, more preferably 15 μm or less, and even more preferably 12 μm or less. The lower limit is not particularly limited, but may be 1 μm or more.

The printed wiring board of this invention can be manufactured by the method including the process of following (I) and (II) using the above-mentioned resin sheet.
(I) The process of laminating | stacking so that the resin composition layer of a resin sheet may join to an inner layer board | substrate on an inner layer board | substrate (II) The process of thermosetting a resin composition layer and forming an insulating layer

  The “inner layer substrate” used in 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 surfaces of the substrate. A circuit board on which a patterned conductor layer (circuit) 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. When the printed wiring board is a circuit board with a built-in component, an inner layer board with a built-in component can be used.

  Lamination | stacking of an inner layer board | substrate and a resin sheet can be performed by heat-pressing a resin sheet to an inner layer board | substrate from the support body side, for example. Examples of the member that heat-presses the resin sheet to the inner layer substrate (hereinafter, also referred to as “heat-pressing member”) include a heated metal plate (SUS end plate) or a metal roll (SUS roll). It is preferable that the thermocompression-bonding member is not pressed directly on the resin sheet, but is pressed through an elastic material such as heat-resistant rubber so that the resin sheet sufficiently follows the surface irregularities of the inner layer substrate.

  Lamination of the inner layer substrate and the resin sheet may be performed by a vacuum laminating method. In the vacuum laminating method, the thermocompression bonding temperature is preferably in the range of 60 ° C to 160 ° C, more preferably 80 ° C to 140 ° C, and the thermocompression bonding pressure is preferably 0.098 MPa to 1.77 MPa, more preferably 0. The thermocompression bonding time is preferably in the range of 20 seconds to 400 seconds, more preferably in the range of 30 seconds to 300 seconds. Lamination is preferably performed under reduced pressure conditions with a pressure of 26.7 hPa or less.

  Lamination can be performed with a commercially available vacuum laminator. Examples of the commercially available vacuum laminator include a vacuum pressure laminator manufactured by Meiki Seisakusho Co., Ltd., a vacuum applicator manufactured by Nikko Materials Co., Ltd., and the like.

  After lamination, the laminated resin sheets may be smoothed under normal pressure (atmospheric pressure), for example, by pressing a thermocompression bonding member from the support side. The pressing conditions for the smoothing treatment can be the same conditions as the thermocompression bonding conditions for the laminate. The smoothing treatment can be performed with a commercially available laminator. In addition, you may perform lamination | stacking and a smoothing process continuously using said commercially available vacuum laminator.

  The support may be removed between step (I) and step (II), or may be removed after step (II).

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

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

  For example, although the thermosetting conditions of the resin composition layer vary depending on the type of the resin composition, the curing temperature is in the range of 120 ° C to 240 ° C (preferably in the range of 150 ° C to 220 ° C, more preferably in the range of 170 ° C to 200 ° C.) and the curing time can be in the range of 5 minutes to 120 minutes (preferably 10 minutes to 100 minutes, more preferably 15 minutes to 90 minutes).

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

  When manufacturing a printed wiring board, you may further implement (III) the process of drilling in an insulating layer, (IV) the process of roughening an insulating layer, and (V) the process of forming a conductor layer. These steps (III) to (V) may be carried out according to various methods known to those skilled in the art, which are used in the production of printed wiring boards. In addition, when removing a support body after process (II), removal of this support body is performed between process (II) and process (III), between process (III) and process (IV), or process ( It may be carried out between IV) and step (V). Moreover, if necessary, the multilayer wiring board may be formed by repeatedly forming the insulating layer and the conductor layer in the steps (II) to (V). In this case, the thickness of the insulating layer between the respective conductor layers (t1 in FIG. 1) is preferably within the above range.

  Step (III) 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. Step (III) may be performed using, for example, a drill, laser, plasma, or the like, depending on the composition of the resin composition used for forming the insulating layer. The dimensions and shape of the holes may be appropriately determined according to the design of the printed wiring board.

  Step (IV) 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 Co., Ltd. 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. From the viewpoint of suppressing the swelling of the resin in the insulating layer to an appropriate level, it is preferable to immerse the insulating layer in a swelling liquid at 40 ° C. to 80 ° C. for 5 minutes to 15 minutes. 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 permanganic acid solutions such as “Concentrate Compact CP” and “Dosing Solution Securigans P” manufactured by Atotech Japan Co., Ltd. The neutralizing solution is preferably an acidic aqueous solution. Examples of commercially available products include “Reduction Solution Securigant P” manufactured by Atotech Japan Co., Ltd. The treatment with the neutralizing solution can be performed by immersing the treated surface subjected to the roughening treatment with the oxidizing agent in the neutralizing solution at 30 to 80 ° C. for 5 to 30 minutes. From the viewpoint of workability and the like, a method of immersing an object subjected to roughening treatment with an oxidizing agent in a neutralizing solution at 40 ° C. to 70 ° C. for 5 minutes to 20 minutes is preferable.

  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 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 (V) is a step of forming a conductor layer. When the conductor layer is not formed on the inner layer substrate, the step (V) is a step of forming the first conductor layer. When the conductor layer is formed on the inner layer substrate, the conductor layer is the first conductor layer. Step (V) is a step of forming the second conductor 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.

  In one embodiment, 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.

  Since the resin sheet of the present invention provides an insulating layer with good component embedding properties, it can be suitably used even when the printed wiring board is a component-embedded circuit board.

As a method of manufacturing such a component built-in circuit board,
(I) an inner substrate having first and second opposing main surfaces and having a cavity penetrating between the first and second main surfaces, and a second main surface of the inner substrate; Preparing a component tacking inner layer substrate, comprising: a tacking material comprising: and a component tacked with the tacking material inside the cavity of the inner layer substrate;
(Ii) a step of laminating the resin sheet of the present invention so that the resin composition layer is bonded to the first main surface of the inner layer substrate;
(Iii) a step of peeling the temporary attachment material from the second main surface of the inner layer substrate;
(Iv) a step of laminating the resin sheet so that the resin composition layer is bonded to the second main surface of the inner layer substrate, and (v) a step of thermosetting the resin composition layer.

  As shown in FIG. 2, the component temporary bonding inner layer substrate 100 (also referred to as “cavity substrate”) has first and second main surfaces 11 and 12 that face each other, and the first and second main surfaces. Inner layer substrate 1 in which a cavity 1a penetrating between the surfaces is formed, temporary attachment material 2 bonded to second main surface 12 of inner layer substrate 1, and temporary attachment material 2 inside cavity 1a of inner layer substrate 1 And the part 3 temporarily attached. The inner layer substrate 1 may include circuit wiring 4 such as via wiring and surface wiring.

  The cavity formed in the inner layer substrate can be formed by a known method using, for example, a drill, a laser, plasma, an etching medium or the like in consideration of the characteristics of the inner layer substrate. A plurality of cavities may be formed at a predetermined interval, and the opening shape of the cavity is not particularly limited, and may be an arbitrary shape such as a rectangle, a circle, a substantially rectangle, or a substantially circle.

  The tacking material is not particularly limited as long as it has an adhesive surface exhibiting sufficient tackiness for tacking a component, and any conventionally known tacking material may be used in the manufacture of the component built-in circuit board. Examples of the tacking material include PFDKE-1525TT (polyimide film with adhesive) manufactured by Arisawa Manufacturing Co., Ltd., and UC series (UV tape for wafer dicing) manufactured by Furukawa Electric Co., Ltd.

  The part is temporarily attached to the adhesive surface of the temporary attachment material exposed through the cavity. As the component, an appropriate electrical component may be selected according to desired characteristics, and examples thereof include passive components such as capacitors, inductors, resistors, multilayer ceramic capacitors, and active components such as semiconductor bare chips. The same part may be used for all cavities, or different parts may be used for each cavity.

  Step (ii) is a step of laminating the resin sheet of the present invention so that the resin composition layer is bonded to the first main surface of the inner layer substrate. The conditions for laminating the first main surface and the resin sheet are the same as those in the above-described step (I), and the preferred range is also the same.

  After the resin composition layer is laminated on the first main surface of the inner layer substrate, the resin composition layer may be thermoset. The conditions for thermosetting the resin composition layer are the same as the conditions of the above-described step (II), and the preferred range is also the same.

  Step (iii) is a step of peeling the temporary attachment material from the second main surface of the inner layer substrate. The peeling of the tacking material may be performed according to a conventionally known method according to the type of the tacking material.

  Step (iv) is a step of laminating the resin sheet such that the resin composition layer is bonded to the second main surface of the inner layer substrate. The conditions for laminating the second main surface and the resin sheet are the same as the conditions for the step (I) described above, and the preferred range is also the same. The resin composition layer in the step (iv) may be the same resin composition layer as the resin composition layer in the step (ii), or may be a different resin composition layer. In the present invention, the resin sheet in step (iv) is preferably the resin sheet of the present invention.

  Step (v) is a step of thermosetting the resin composition layer. The conditions for thermosetting the resin composition layer are the same as the conditions of the above-described step (II), and the preferred range is also the same.

  The component built-in circuit board manufacturing method further includes a step of drilling the insulating layer (drilling step), a step of roughening the surface of the insulating layer, and a step of forming a conductor layer on the roughened insulating layer surface. May be included. These steps are as described above.

  The printed wiring board of this invention may be an aspect provided with the insulating layer which is the hardened | cured material of the resin composition layer of the resin sheet of this invention, and the embedding type wiring layer embedded in the insulating layer.

As a manufacturing method of such a printed wiring board,
(1) preparing a substrate with a wiring layer having an inner layer substrate and a wiring layer provided on at least one surface of the substrate;
(2) The step of laminating the resin sheet of the present invention on a substrate with a wiring layer so that the wiring layer is embedded in the resin composition layer and thermally curing to form an insulating layer;
(3) a step of interconnecting the wiring layers, and (4) a step of removing the base material.

  It is preferable to have a metal layer made of copper foil or the like on both surfaces of the inner layer substrate used in this manufacturing method, and it is more preferable that the metal layer has a structure in which two or more metal layers are laminated. For the details of the step (1), a dry film (photosensitive resist film) is laminated on the inner layer substrate, and exposed and developed under a predetermined condition using a photomask to form a pattern dry film. A wiring layer is formed by electroplating using the developed pattern dry film as a plating mask, and then the pattern dry film is peeled off.

  The lamination conditions of the inner layer substrate and the dry film are the same as the conditions of the step (II) described above, and the preferred range is also the same.

  After laminating the dry film on the inner layer substrate, exposure and development are performed under predetermined conditions using a photomask in order to form a desired pattern on the dry film.

  The line (circuit width) / space (inter-circuit width) ratio of the wiring layer is not particularly limited, but is preferably 20/20 μm or less (that is, the pitch is 40 μm or less), more preferably 18/18 μm or less (pitch 36 μm or less), More preferably, it is 15/15 μm or less (pitch 30 μm or less). The lower limit of the line / space ratio of the wiring layer is not particularly limited, but is preferably 0.5 / 0.5 μm or more, more preferably 1/1 μm or more. The pitch need not be the same throughout the wiring layer.

  After forming the dry film pattern, a wiring layer is formed, and the dry film is peeled off. Here, the wiring layer can be formed by a plating method using a dry film having a desired pattern as a plating mask.

  The conductor material used for the wiring layer is not particularly limited. In a preferred embodiment, the wiring 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 wiring 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 nickel alloy and a copper / titanium alloy).

  The thickness of the wiring layer is preferably 3 μm to 35 μm, more preferably 5 μm to 30 μm, still more preferably 10 to 20 μm, or 15 μm, although it depends on the desired wiring board design.

  After forming the wiring layer, the dry film is peeled off. Peeling of the dry film can be performed by a known method. If necessary, an unnecessary wiring pattern can be removed by etching or the like to form a desired wiring pattern.

  Step (2) is a step of laminating the resin sheet of the present invention on a substrate with a wiring layer so that the wiring layer is embedded in the resin composition layer, and thermosetting to form an insulating layer. The lamination conditions of the base material with a wiring layer and the resin sheet are the same as the conditions of the step (II) described above, and the preferable range is also the same.

  The step (3) is not particularly limited as long as the wiring layers can be connected to each other, but a step of forming a via hole in the insulating layer to form a conductor layer, and a step of polishing or grinding the insulating layer to expose the wiring layer It is preferable that it is at least one of these steps. The process of forming the via hole in the insulating layer and forming the conductor layer is as described above.

  The insulating layer polishing method or grinding method is not particularly limited as long as the wiring layer can be exposed and the polishing or grinding surface is horizontal, and conventionally known polishing methods or grinding methods can be applied, for example, And a chemical mechanical polishing method using a chemical mechanical polishing apparatus, a mechanical polishing method such as buffing, and a surface grinding method by rotating a grindstone.

  Step (4) is a step of removing the inner substrate and forming the wiring board of the present invention. The method for removing the inner layer substrate is not particularly limited. In a preferred embodiment, the inner layer substrate is peeled from the wiring board at the interface of the metal layer on the inner layer substrate, and the metal layer is removed by etching with, for example, an aqueous copper chloride solution.

The wiring board produced using the resin sheet of the present invention exhibits a characteristic that the insulation reliability is excellent even when the thickness of the insulating layer between the first and second conductor layers is 6 μm or less. The upper limit of the insulation resistance value after elapse of 200 hours in an environment of 130 ° C., 85 RH%, 3.3 V is preferably 10 ¹² Ω or less, more preferably 10 ¹¹ Ω or less, and still more preferably 10 ¹⁰ Ω or less. The lower limit is preferably 10 ⁷ Ω or more, more preferably 10 ⁸ Ω or more. The insulation resistance value can be measured according to the method described in <Evaluation of insulation reliability, measurement of thickness of insulating layer between conductor layers> described later.

  The printed wiring board manufactured using the resin sheet of the present invention exhibits the characteristics of excellent pattern embedding property and component embedding property. The evaluation of pattern embedding can be performed according to the method described in <Evaluation of pattern embedding> described later.

  The wiring board manufactured using the resin sheet of the present invention exhibits the characteristic that the amount of reflow warpage can be suppressed. The upper limit of the reflow warpage amount at a peak temperature of 260 ° C. is preferably 90 μm, more preferably 80 μm, and still more preferably 70 μm. The lower limit is not particularly limited, but may be 1 μm or more. The reflow warpage amount can be evaluated according to the method described in <Evaluation of warpage amount> described later.

[Semiconductor device]
The semiconductor device of the present invention includes the printed wiring board of the present invention. The semiconductor device of the present invention can be manufactured using the printed wiring board of the present invention.

  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).

  The semiconductor device of the present invention can be manufactured by mounting a component (semiconductor chip) on a conductive portion of a printed wiring board. The “conduction location” is a “location where an electrical signal is transmitted on a printed wiring board”, and the location may be a surface or an embedded location. The semiconductor chip is not particularly limited as long as it is an electric circuit element made of a semiconductor.

  The semiconductor chip mounting method for manufacturing the semiconductor device of the present invention is not particularly limited as long as the semiconductor chip functions effectively, but specifically, a wire bonding mounting method, a flip chip mounting method, and no bumps. Examples include a mounting method using a build-up layer (BBUL), a mounting method using an anisotropic conductive film (ACF), and a mounting method using a non-conductive film (NCF). Here, “a mounting method using a build-up layer without a bump (BBUL)” means “a mounting method in which a semiconductor chip is directly embedded in a recess of a printed wiring board and the semiconductor chip and wiring on the printed wiring board are connected”. It is.

  EXAMPLES 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.

[Method for measuring physical properties of inorganic filler]
First, a method for measuring and evaluating an inorganic filler will be described.

<Measurement of average particle size>
100 mg of inorganic filler, 0.1 g of a dispersant (“SN9228” manufactured by San Nopco Co., Ltd.) and 10 g of methyl ethyl ketone were weighed in a vial and dispersed with an ultrasonic wave for 20 minutes. Using a laser diffraction particle size distribution measuring device (“SALD-2200” manufactured by Shimadzu Corporation), the particle size distribution was measured by a batch cell method, and the average particle size according to the median diameter was calculated.

<Measurement of specific surface area>
The specific surface area of the inorganic filler was measured using a BET fully automatic specific surface area measuring device (Macsorb HM-1210 manufactured by Mountec Co., Ltd.).

<Measurement of carbon content>
The amount of carbon per unit surface area of the inorganic filler was measured according to the following procedure. A sufficient amount of methyl ethyl ketone (MEK) as a solvent was added to the inorganic filler prepared in Preparation Example and ultrasonically cleaned at 25 ° C. for 5 minutes. Subsequently, the supernatant was removed and the solid content was dried. About the obtained solid, carbon amount was measured using the carbon analyzer ("EMIA-320V" by Horiba, Ltd.). Based on the measured value of the carbon amount and the mass and specific surface area of the inorganic filler used, the carbon amount per unit surface area of the inorganic filler was calculated.

[Preparation of resin composition]
<Preparation of Resin Composition 1>
6 parts cyclohexanedimethanol type epoxy resin (“ZX1658GS” manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., epoxy equivalent of about 169), 6 parts of bixylenol type epoxy resin (“YX4000HK” manufactured by Mitsubishi Chemical Corporation, about 185 epoxy equivalent), 6 parts of bisphenol AF type epoxy resin (“YL7760” manufactured by Mitsubishi Chemical Corporation, epoxy equivalent of about 238), 15 parts of naphthalene type epoxy resin (“ESN475V” manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., about 330 equivalent of epoxy), phenoxy resin 10 parts (Mitsubishi Chemical Co., Ltd. “YX7553BH30”, 30 mass% solid solution of cyclohexanone: methyl ethyl ketone (MEK) 1: 1 solution) 10 parts dissolved in a mixed solvent of 20 parts of solvent naphtha and 10 parts of cyclohexanone with stirring. I let you. After cooling to room temperature, 35 parts of an active ester curing agent (“EXB-8000L-65TM” manufactured by DIC Corporation, an active group equivalent of about 220, a toluene / MEK solution containing 65% by mass of non-volatile components), amine Type curing accelerator (4-dimethylaminopyridine (DMAP), MEK solution having a solid content of 5% by mass), aminosilane coupling agent (“KBM573” manufactured by Shin-Etsu Chemical Co., Ltd.) and phenyltrimethoxysilane (Shin-Etsu) Spherical silica (“UFP-30” manufactured by Denki Kagaku Kogyo Co., Ltd.) having an average particle size of 0.078 μm and a specific surface area of 30.7 m ^2. / g, a mixture of carbon amount 0.20mg ^/ m 2) 95 parts per unit surface area, after uniformly dispersed in a high-speed rotary mixer, a cartridge filter (RO It was filtered through a ITECHNO made "SHP020"), to prepare a resin composition 1.

<Preparation of resin composition 2>
2 parts of glycidylamine type epoxy resin ("630LSD" manufactured by Mitsubishi Chemical Corporation, epoxy equivalent of about 95), 8 parts of bixylenol type epoxy resin ("YX4000HK" manufactured by Mitsubishi Chemical Corporation, about 185 epoxy equivalent), naphthylene 6 parts of an ether type epoxy resin (“EXA-731-G4” manufactured by DIC Corporation, epoxy equivalent of about 213), 15 parts of a biphenyl type epoxy resin (“NC3000L” manufactured by Nippon Kayaku Co., Ltd., about 272 of epoxy equivalent), And 6 parts of phenoxy resin (“YX7553BH30” manufactured by Mitsubishi Chemical Corporation, 1: 1 solution of cyclohexanone: methyl ethyl ketone (MEK) having a solid content of 30% by mass) are stirred in a mixed solvent of 15 parts of solvent naphtha and 10 parts of cyclohexanone. The solution was dissolved while heating. After cooling to room temperature, 10 parts of a triazine skeleton-containing cresol novolac-based curing agent (“LA3018-50P” manufactured by DIC Corporation, hydroxyl equivalent of about 151, 2-methoxypropanol solution with a solid content of 50%), activity Ester-based curing agent (“EXB-8000L-65TM” manufactured by DIC Corporation, 15 parts of a toluene / MEK solution having an active group equivalent of about 220 and a non-volatile component of 65% by mass), an amine-based curing accelerator (4-dimethylaminopyridine ( DMAP), 1 part of MEK solution having a solid content of 5% by weight, 2 parts of rubber particles (“EXL2655” manufactured by Dow Chemical Japan Co., Ltd.), aminosilane coupling agent (“KBM573” manufactured by Shin-Etsu Chemical Co., Ltd.) Surface treated with spherical silica (“SPH516-05” manufactured by Nippon Steel & Sumikin Materials Co., Ltd., average particle size 0.29 μm, specific surface 16.3 m ² / g, carbon content 0.43 mg ^/ m 2) 60 parts per unit surface area, aminosilane coupling agent (Shin-Etsu Chemical Co., Ltd., "KBM573") and phenyl trimethoxy silane (manufactured by Shin-Etsu Chemical ( Co., Ltd. “KBM103”) surface-treated spherical silica (“UFP-30” manufactured by Denki Kagaku Kogyo Co., Ltd.), average particle size 0.078 μm, specific surface area 30.7 m ² / g, 40 parts of carbon per unit surface area (0.20 mg / m ² ) were mixed and dispersed uniformly with a high-speed rotary mixer, and then filtered with a cartridge filter (“SHP020” manufactured by ROKITECHNO) to prepare a resin composition 2 .

<Preparation of resin composition 3>
4 parts of naphthalene type epoxy resin (DIC Corporation "HP4032SS", epoxy equivalent of about 144), naphthylene ether type epoxy resin (DIC Corporation "EXA-731-G4", epoxy equivalent of about 213), 12 parts, 15 parts of naphthalene type epoxy resin (“ESN475V” manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., epoxy equivalent of about 330) and phenoxy resin (“YX7553BH30” manufactured by Mitsubishi Chemical Corporation), cyclohexanone: methyl ethyl ketone (MEK) having a solid content of 30% by mass 1: 1 solution) was dissolved in a mixed solvent of 15 parts of solvent naphtha and 10 parts of cyclohexanone with stirring. After cooling to room temperature, 30 parts of a prepolymer of bisphenol A dicyanate ("BA230S75" manufactured by Lonza Japan Co., Ltd., MEK solution having a cyanate equivalent of about 232 and a nonvolatile content of 75% by mass), an active ester curing agent ( DIC Corporation "HPC-8000-65T", active group equivalent of about 225, non-volatile component 65% by weight toluene solution) 8 parts, amine curing accelerator (4-dimethylaminopyridine (DMAP), solid content 5 mass % MEK solution) 0.4 part, curing accelerator (manufactured by Tokyo Chemical Industry Co., Ltd., cobalt (III) acetylacetonate (CO (III) Ac), MEK solution having a solid content of 1% by weight) 3 parts, flame retardant (“HCA-HQ” manufactured by Sanko Co., Ltd., 10- (2,5-dihydroxyphenyl) -10-hydro-9-oxa-10-phosphophenanthrene -10-oxide, average particle size 1.1 μm) 2 parts, spherical silica surface treated with aminosilane coupling agent (“KBM573” manufactured by Shin-Etsu Chemical Co., Ltd.) (“SPH516 manufactured by Nippon Steel & Sumikin Materials Co., Ltd.”) -05 ", average particle size 0.29 [mu] m, specific surface area 16.3 m < ² > / g, carbon amount 0.43 mg / m < ² > per unit surface area), epoxy silane coupling agent (Shin-Etsu Chemical Co., Ltd.) “KBM403”) and phenyltrimethoxysilane (“KBM103” manufactured by Shin-Etsu Chemical Co., Ltd.) surface-treated with a weight ratio of 1: 1, spherical silica (“UFP-40” manufactured by Denki Kagaku Kogyo Co., Ltd.), average particle size 30 parts of diameter 0.067 μm, specific surface area 40.8 m ² / g, carbon amount per unit surface area 0.19 mg / m ² ) are mixed and uniformly dispersed with a high-speed rotary mixer Then, it was filtered with a cartridge filter (“SHP020” manufactured by ROKITECHNO) to prepare a resin composition 3.

<Preparation of resin composition 4>
Bisphenol type epoxy resin (“ZX1059” manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., epoxy equivalent of about 169, 1: 1 mixture of bisphenol A type and bisphenol F type) 6 parts, bixylenol type epoxy resin (manufactured by Mitsubishi Chemical Corporation) 6 parts of “YX4000HK”, epoxy equivalent of about 185), 6 parts of bisphenol AF type epoxy resin (“YL7760” manufactured by Mitsubishi Chemical Corporation, epoxy equivalent of about 238), naphthalene type epoxy resin (“ESN475V” manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.) 15 parts of epoxy equivalent (about 330), 10 parts of phenoxy resin (“YX7553BH30” manufactured by Mitsubishi Chemical Corporation, 1: 1 solution of cyclohexanone: methyl ethyl ketone (MEK) having a solid content of 30% by mass), 25 parts of solvent naphtha and Heat and dissolve in a mixed solvent of 10 parts of cyclohexanone with stirring. It was. After cooling to room temperature, 35 parts of an active ester curing agent (“EXB-8000L-65TM” manufactured by DIC Corporation, an active group equivalent of about 220, a toluene / MEK solution containing 65% by mass of non-volatile components), amine System curing accelerator (4-dimethylaminopyridine (DMAP), MEK solution having a solid content of 5% by mass), epoxysilane coupling agent (“KBM403” manufactured by Shin-Etsu Chemical Co., Ltd.) and phenyltrimethoxysilane ( Spherical silica surface-treated with a weight ratio of 1: 1 (“KBM103” manufactured by Shin-Etsu Chemical Co., Ltd.) (“UFP-40” manufactured by Denki Kagaku Kogyo Co., Ltd.), average particle size 0.067 μm, specific surface area 40.8 m ² / g, carbon content 0.19 mg ^/ m 2) were mixed 95 parts per unit surface area, after uniformly dispersed in a high-speed rotary mixer, a cartridge filter (R It was filtered through a KITECHNO made "SHP020"), to prepare a resin composition 4.

<Preparation of resin composition 5>
In the preparation of resin composition 3, 1) the amount of solvent naphtha added was changed from 15 parts to 8 parts, and 2) two inorganic fillers (two kinds of spherical silica) were converted into an epoxysilane coupling agent (Shin-Etsu Chemical). Spherical silica surface-treated with “KBM403” manufactured by Kogyo Co., Ltd. (“Admafine SO-C1” manufactured by Admatechs Co., Ltd.), average particle size 0.63 μm, specific surface area 11.2 m ² / g, per unit surface area changed to a carbon content 0.28 mg ^/ m 2) 110 parts, 3) the cartridge filter (ROKITECHNO manufactured "SHP020"), a cartridge filter (ROKITECHNO manufactured "SHP030") and except for changing the the preparation of the resin composition 3 Similarly, a resin composition 5 was prepared.

<Preparation of resin composition 6>
2 parts of glycidylamine type epoxy resin ("630LSD" manufactured by Mitsubishi Chemical Corporation, epoxy equivalent of about 95), 8 parts of bixylenol type epoxy resin ("YX4000HK" manufactured by Mitsubishi Chemical Corporation, about 185 epoxy equivalent), naphthylene 6 parts of an ether type epoxy resin (“EXA-731-G4” manufactured by DIC Corporation, epoxy equivalent of about 213), 15 parts of a biphenyl type epoxy resin (“NC3000L” manufactured by Nippon Kayaku Co., Ltd., about 272 of epoxy equivalent), And 10 parts of phenoxy resin ("YX7553BH30" manufactured by Mitsubishi Chemical Corporation, 1: 1 solution of cyclohexanone: methyl ethyl ketone (MEK) having a solid content of 30% by mass) are stirred in a mixed solvent of 10 parts of solvent naphtha and 5 parts of cyclohexanone. The solution was dissolved while heating. After cooling to room temperature, 10 parts of a triazine skeleton-containing cresol novolac-based curing agent (“LA3018-50P” manufactured by DIC Corporation, hydroxyl equivalent of about 151, 2-methoxypropanol solution with a solid content of 50%), activity Ester-based curing agent (“EXB-8000L-65TM” manufactured by DIC Corporation, 15 parts of a toluene / MEK solution having an active group equivalent of about 220 and a non-volatile component of 65% by mass), an amine-based curing accelerator (4-dimethylaminopyridine ( DMAP), 1 part of MEK solution having a solid content of 5% by weight, 2 parts of rubber particles (“EXL2655” manufactured by Dow Chemical Japan Co., Ltd.), epoxysilane coupling agent (“KBM403” manufactured by Shin-Etsu Chemical Co., Ltd.) ) And phenyltrimethoxysilane (“KBM103” manufactured by Shin-Etsu Chemical Co., Ltd.) are surface-treated at a weight ratio of 1: 1. (Denki Kagaku Kogyo Co., Ltd. "UFP-40", average particle diameter 0.067Myuemu, a specific surface area of 40.8m ² / g, carbon content 0.19 mg ^/ m 2 per unit surface area) were mixed 35 parts, high speed After uniformly dispersing with a rotary mixer, the resin composition 6 was prepared by filtering with a cartridge filter (“SHP020” manufactured by ROKITECHNO).

  Table 1 shows the components used for the preparation of the resin compositions 1 to 6 and their blending amounts (parts by mass of the nonvolatile content).

[Production of resin sheet]
As a support, a PET film (“Lumirror R80” manufactured by Toray Industries, Inc.) having a release treatment with an alkyd resin release agent (“AL-5” manufactured by Lintec Corporation), a thickness of 38 μm, a softening point of 130 ° C. Type PET ").

  Each resin composition was uniformly applied with a die coater so that the thickness of the resin composition layer after drying was 13 μm on the release PET, and dried at 70 ° C. to 95 ° C. for 2 minutes, thereby releasing the release PET. A resin composition layer was obtained on top. Next, a rough surface of a polypropylene film (“Alphan MA-411” manufactured by Oji F-Tex Co., Ltd., thickness 15 μm) as a protective film is bonded to the resin composition layer on the surface of the resin sheet that is not bonded to the support. Laminated so that. This obtained the resin sheet which consists of order of mold release PET (support body), a resin composition layer, and a protective film.

[Evaluation test]
<Measurement of minimum melt viscosity>
Only the resin composition layer was peeled from the resin sheet and compressed with a mold to prepare measurement pellets (diameter 18 mm, 1.2 to 1.3 g).

  Using a dynamic viscoelasticity measuring apparatus (“Rheosol-G3000” manufactured by UBM Co., Ltd.), using a parallel plate with a diameter of 18 mm, a starting temperature of 60 ° C. to 200 ° C. is used for 1 g of the sample resin composition layer. The temperature was raised at a rate of 5 ° C./min until the measurement, and the dynamic viscoelasticity was measured under the measurement conditions of a measurement temperature interval of 2.5 ° C., a frequency of 1 Hz, a strain of 1 deg, and a strain of 5 deg. ) Respectively. The minimum melt viscosity (poise) obtained by performing dynamic viscoelasticity measurement under the conditions of a frequency of 1 Hz and a strain of 1 deg is described in the column of “Minimum melt viscosity at a strain of 1 deg” in Table 2, with a frequency of 1 Hz and strain. The minimum melt viscosity (poise) obtained by performing dynamic viscoelasticity measurement under the condition of 5 deg is described in the column of “Minimum melt viscosity at 5 deg strain” in Table 2.

<Measurement of average linear thermal expansion coefficient (CTE) of cured product>
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, Ltd. “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 PET film were fixed with polyimide adhesive tape (width 10 mm).

  Each resin sheet produced in the Examples and Comparative Examples was batch-type vacuum pressure laminator (Nikko Materials Co., Ltd. 2-stage build-up laminator, CVP700), and the resin composition layer was the release PET film. Lamination was performed at the center so as to be in contact with the mold release surface of “Lintec Co., Ltd.“ 501010 ””. 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.

  Next, it was cured at 30 ° C. for 30 minutes after being put in a 100 ° C. oven under a temperature condition of 100 ° C., and then for 30 minutes after being transferred to a 180 ° C. oven under a temperature condition of 180 ° C. Thereafter, the substrate was taken out in a room temperature atmosphere, and the release PET (support) was peeled off from the resin sheet. Then, the substrate was put into an oven at 200 ° C. and then cured by curing for 90 minutes.

  After thermosetting, the polyimide adhesive tape was peeled off, and the cured product was removed from the glass cloth base epoxy resin double-sided copper-clad laminate. Further, the release PET film (“501010” manufactured by Lintec Corporation) on which the resin composition layer was laminated was peeled off to obtain a sheet-like cured product. The obtained cured product is referred to as “evaluated cured product”.

  The cured product for evaluation 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). 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. The average linear thermal expansion coefficient (ppm / ° C.) in the plane direction in the range from 25 ° C. to 150 ° C. was calculated in two measurements and is shown in Table 2.

<Evaluation of pattern embedding and flatness>
(Preparation of evaluation substrate)
(1) Underlayer treatment of inner layer circuit board Glass cloth base epoxy resin double-sided copper having circuit conductor (copper) formed on both sides as a 1 mm square lattice wiring pattern (residual copper ratio 59%) as inner layer circuit board A stretched laminate (copper foil thickness 18 μm, substrate thickness 0.15 mm, “HL832NSF LCA”, 255 * 340 mm size, manufactured by Mitsubishi Gas Chemical Co., Inc.) was prepared. Both surfaces of the inner layer circuit board were subjected to a copper surface roughening treatment (copper etching amount of 0.5 μm) using “CZ8201” manufactured by MEC.

(2) Lamination of resin sheet Each resin sheet produced in the examples and comparative examples was subjected to resin composition using a batch type vacuum pressure laminator (manufactured by Nikko Materials Co., Ltd., 2-stage buildup laminator, CVP700). The inner layer circuit board was laminated on both surfaces so that the physical layer was in contact with the inner layer circuit board. Lamination was performed by reducing the pressure for 30 seconds to a pressure of 13 hPa or less, and pressing for 45 seconds at 130 ° C. and a pressure of 0.74 MPa. Next, hot pressing was performed at 120 ° C. and a pressure of 0.5 MPa for 75 seconds.

(3) Thermosetting of resin composition layer The inner layer circuit board on which the resin sheet is laminated is placed in a 100 ° C. oven at 100 ° C. for 30 minutes and then in a 180 ° C. oven at 180 ° C. After the transfer, the thermosetting was performed for 30 minutes to form an insulating layer. This is referred to as “evaluation substrate A”.

(Evaluation of pattern embedding)
The support was peeled off from the evaluation substrate A, and the surface of the insulating layer was observed with a micro optical microscope. When sufficient voids were generated, it was evaluated as “x” and shown in Table 2. In Comparative Example 1, since the minimum melt viscosity at strain 1 deg and strain 5 deg was too high to embed the pattern, the following evaluation tests (evaluation of flatness, evaluation of insulation reliability, insulation layer between conductor layers) Measurement of thickness and evaluation of warpage amount) could not be performed.

(Evaluation of flatness)
The support was peeled off from the evaluation substrate A, and the flatness of the insulating layer in the region on the lattice pattern was measured with a non-contact type surface roughness meter (“WYKO NT3300” manufactured by Beec Instruments). The maximum cross-sectional height Rt was measured in four regions of 10 × magnification and 0.82 mm × 1.1 mm, and the average value was calculated. The case where the average value of Rt was 1.5 μm or less was evaluated as “◯”, and the case where it exceeded 1.5 μm was evaluated as “×”.

<Evaluation of insulation reliability, measurement of insulation layer thickness between conductor layers>
(4) Formation of via hole From the upper side of the insulating layer and the support of the evaluation substrate A prepared in (3), using a CO ₂ laser processing machine “605GTWIII (-P)” manufactured by Mitsubishi Electric Corporation. Laser was irradiated from above the body to form a via hole having a top diameter (70 μm) in the insulating layer on the conductor of the lattice pattern. The laser irradiation conditions were a mask diameter of 2.5 mm, a pulse width of 16 μs, an energy of 0.39 mJ / shot, a shot number of 2, and a burst mode (10 kHz).

(5) Roughening process The support body was peeled from the circuit board provided with the via hole, and the desmear process was performed. In addition, as a desmear process, the following wet desmear process was implemented.

Wet desmear treatment:
Swelling solution (“Swelling Dip Securigant P” manufactured by Atotech Japan Co., Ltd., diethylene glycol monobutyl ether and sodium hydroxide aqueous solution) at 60 ° C. for 5 minutes, and then an oxidant solution (“Concentrate” manufactured by Atotech Japan Co., Ltd.)・ Compact CP ”, aqueous solution with potassium permanganate concentration of about 6%, sodium hydroxide concentration of about 4%) at 80 ° C. for 10 minutes, and finally neutralization solution (“ Reduction Solution Securigant P manufactured by Atotech Japan Co., Ltd.) ”, Immersed in sulfuric acid aqueous solution) at 40 ° C. for 5 minutes, and then dried at 80 ° C. for 15 minutes.

(6) Step of forming conductor layer (6-1) Electroless plating step In order to form a conductor layer on the surface of the circuit board, a plating step including the following steps 1 to 6 (chemical solution manufactured by Atotech Japan Co., Ltd.) The copper plating process using was performed to form a conductor layer.

1. Alkali cleaning (cleaning and charge adjustment of the surface of the insulating layer with via holes)
Product name: Cleaned at 60 ° C. for 5 minutes using Cleaning Cleaner Security 902 (trade name).
2. Soft etching (cleaning inside via holes)
The mixture was treated with an aqueous sodium peroxodisulfate solution at 30 ° C. for 1 minute.
3. Pre-dip (adjustment of surface charge of insulating layer for Pd application)
Pre. Using Dip Neoganth B (trade name), it was treated at room temperature for 1 minute.
4). Activator application (Pd application to the surface of the insulating layer)
Using Activator Neoganth 834 (trade name), it was treated at 35 ° C. for 5 minutes.
5). Reduction (reduction of Pd applied to the insulating layer)
Reducer Neoganth WA (trade name) and Reducer Accelerator 810 mod. Using a mixed solution with (trade name), it was treated at 30 ° C. for 5 minutes.
6). Electroless copper plating process (Cu is deposited on the surface of the insulating layer (Pd surface))
Using a mixture of Basic Solution Print MSK-DK (trade name), Copper solution Print MS MS (trade name), Stabilizer Printganth MSK-DK (trade name), and Reducer Cu (trade name) at 35 ° C. Treated for 20 minutes. The thickness of the formed electroless copper plating layer was 0.8 μm.

(6-2) Electrolytic plating process Subsequently, the electrolytic copper plating process was performed on the conditions with which a via hole is filled with copper using the chemical solution made from Atotech Japan. Thereafter, as a resist pattern for patterning by etching, a land pattern having a diameter of 1 mm conducted to the via hole and a circular conductor pattern having a diameter of 10 mm not connected to the lower layer conductor are used to form a thickness of 10 μm on the surface of the insulating layer. A conductor layer having lands and conductor patterns was formed. Next, annealing was performed at 200 ° C. for 90 minutes. This substrate was designated as an evaluation substrate B.

(Measurement of insulation layer thickness between conductor layers)
The evaluation substrate B was subjected to cross-sectional observation using a FIB-SEM composite device (“SMI3050SE” manufactured by SII Nanotechnology Co., Ltd.). Specifically, the cross section in the direction perpendicular to the surface of the conductor layer was cut out by FIB (focused ion beam), and the insulating layer thickness between the conductor layers was measured from the cross section SEM image. For each sample, five cross-sectional SEM images selected at random were observed, and the average value was defined as the thickness (μm) of the insulating layer between the conductor layers.

(Evaluation of insulation reliability of insulation layer)
A highly accelerated life test apparatus (with the 10 mm diameter circular conductor side of the evaluation substrate A obtained above as the + electrode and the grid conductor (copper) side of the inner layer circuit board connected to the 1 mm diameter land as the − electrode) Using an ETAC "PM422"), the insulation resistance value after passing 200 hours under the conditions of 130 ° C, 85% relative humidity and 3.3V DC voltage application is an electrochemical migration tester (J-RAS Co., Ltd.). ("ECM-100" manufactured by the manufacturer)) (n = 6). In all six test pieces, when the resistance value is 10 ⁷ Ω or more, “○” is indicated, and when any one is less than 10 ⁷ Ω, “X” is indicated. Table 2 shows the evaluation results and the insulation resistance values. It was. The insulation resistance values listed in Table 2 are the minimum insulation resistance values of the six test pieces.

<Evaluation of warpage amount>
(Preparation of evaluation substrate C)
After peeling the support from the evaluation substrate A, thermosetting was performed at 200 ° C. for 90 minutes. The obtained substrate was used as an evaluation substrate C.

(Evaluation test for reflow warpage)
After the evaluation substrate C was cut into 45 mm square pieces (n = 5), it was passed once through a reflow apparatus (“HAS-6116” manufactured by Nippon Antom Co., Ltd.) that reproduces the solder reflow temperature with a peak temperature of 260 ° C. (The reflow temperature profile conforms to IPC / JEDEC J-STD-020C). Then, using a shadow moire device (“Thermoire AXP” manufactured by Akrometrix), the bottom 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 amount of displacement (μm) at the corners was measured, and the measurement results are shown in Table 2.

100 Component temporary bonding inner layer substrate (cavity substrate)
DESCRIPTION OF SYMBOLS 1 Inner layer board | substrate 1a Cavity 11 1st main surface 12 2nd main surface 2 Tacking material 3 Parts 4 Circuit wiring 5 1st conductor layer 51 1st conductor layer main surface 6 2nd conductor layer 61 2nd Main surface 7 of the conductor layer of the insulating layer

Claims (8)

(A) An epoxy resin, (B) a curing agent, and (C) a resin sheet comprising a resin composition layer containing an inorganic filler,
When the nonvolatile component in the resin composition layer is 100% by mass, (C) the inorganic filler is 50% by mass or more,
The resin composition layer has a minimum melt viscosity of 8000 poise or more at a frequency of 1 Hz and a strain of 1 deg.
The resin composition layer has a minimum melt viscosity of 8000 poise or less at a frequency of 1 Hz and a strain of 5 deg.
Resin sheet.   The resin sheet according to claim 1, wherein the resin composition layer has a thickness of 15 μm or less.   (A) The resin sheet of Claim 1 or 2 in which an epoxy resin contains a liquid liquid epoxy resin.   (C) The resin sheet of any one of Claims 1-3 whose average particle diameter of an inorganic filler is 0.05-0.35 micrometer.   The resin sheet according to any one of claims 1 to 4, which is used for forming an insulating layer of a printed wiring board.   Formation of an insulating layer of a printed wiring board including a first conductor layer, a second conductor layer, and an insulating layer of 6 μm or less formed between the first conductor layer and the second conductor layer The resin sheet according to any one of claims 1 to 5, which is for use. A printed wiring board including a first conductor layer, a second conductor layer, and an insulating layer of 6 μm or less formed between the first conductor layer and the second conductor layer,
The printed wiring board, wherein the insulating layer is a cured product of the resin composition layer of the resin sheet according to any one of claims 1 to 6.   A semiconductor device comprising the printed wiring board according to claim 7.

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