KR102324901B1 - Resin sheet - Google Patents

Abstract

[Problem] To provide a resin sheet capable of suppressing reflow warpage and providing a thin insulating layer excellent in insulating performance.
[Solution means] A resin sheet comprising a resin composition layer containing (A) an epoxy resin, (B) a curing agent, and (C) an inorganic filler, wherein the nonvolatile component in the resin composition layer is 100% by mass. , (C) the inorganic filler is 50% by mass or more, the minimum melt viscosity obtained by performing dynamic viscoelasticity measurement under the conditions of a frequency of 1 Hz and a strain of 1deg of the resin composition layer is 8000 poise or more, of the resin composition layer, A resin sheet having a minimum melt viscosity of 8000 poise or less obtained by performing dynamic viscoelasticity measurement under conditions of a frequency of 1 Hz and a strain of 5 deg.

Description

Resin sheet {RESIN SHEET}

The present invention relates to a resin sheet. Moreover, 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 size reduction of an electronic device, thickness reduction of a printed wiring board is progressing further, and the thickness of an inner-layer board|substrate and an insulating layer tends to become thinner. As a technique of making the thickness of an inner-layer board|substrate or an insulating layer thin, the resin composition for thin films of patent document 1 is known, for example.

Patent Document 1: Japanese Patent Laid-Open No. 2014-152309

In Patent Document 1, the present inventors found that when a thin film is applied to an insulating layer, the roughness increases and the peel strength tends to decrease, and in order to solve these problems, the compounding amount of the thermoplastic resin is reduced. It is suggested to do it quantitatively. However, in this document, the insulation performance (hereinafter also referred to as "thin film insulation") when the thickness of the insulation layer is made thin is not examined at all.

When an insulating layer is made into a thin film, since reflow curvature becomes easy to occur, suppressing reflow curvature by putting in many inorganic fillers can be considered. However, when the content of the inorganic filler increases, it becomes difficult to maintain the insulating performance such as an electric current easily flows through the interface where the inorganic filler particles adhere. It becomes a relationship of this trade-off.

An object of the present invention is to provide a resin sheet capable of suppressing reflow warpage and providing a thin insulating layer excellent in insulating performance.

As a result of earnestly examining in order to solve the said subject, the present inventors acquired the following knowledge.

In order to maintain insulation in the insulating layer of a thin film, it can be considered to improve the embedding property while increasing the flatness of the insulating layer. By setting it as more than poise, the movement of the resin composition layer in a thermosetting process etc. is suppressed, and flatness improves. On the other hand, when a pressure is applied in a lamination process by making the minimum melt viscosity at a frequency of 1 Hz and a deformation|transformation 5 deg into 8000 poise or less, embedding property becomes favorable.

That is, the present inventors, in the resin sheet provided with the resin composition layer containing an epoxy resin, a hardening|curing agent, and an inorganic filler, while the resin composition layer contains 50 mass % or more of inorganic fillers, the frequency of 1 Hz of the resin composition layer , by making the minimum melt viscosity at strain 1deg 8000 poise or more, and the frequency of the resin composition layer at 1 Hz and strain 5deg into 8000 poise or less, reflow warpage is suppressed, and even though the thickness is thin and found that it is possible to provide an insulating layer excellent in insulating performance (excellent in thin film insulating properties), thereby completing the present invention.

That is, the present invention includes the following contents.

[1] A resin sheet comprising a resin composition layer comprising (A) an epoxy resin, (B) a curing agent, and (C) an inorganic filler, wherein the nonvolatile component in the resin composition layer is 100% by mass, (C) the inorganic filler is 50 mass % or more, the minimum melt viscosity of the resin composition layer at a frequency of 1 Hz and strain 1deg is 8000 poise or more, and the resin composition layer has a frequency of 1 Hz and a minimum at strain 5deg A resin sheet having a melt viscosity of 8000 poise or less.

[2] The resin sheet according to [1], wherein the thickness of the resin composition layer is 15 µm or less.

[3] (A) The resin sheet according to [1] or [2], wherein the epoxy resin contains a liquid epoxy resin.

[4] (C) The resin sheet according to any one of [1] to [3], wherein the inorganic filler has an average particle diameter of 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 first conductor layer, a second conductor layer, and an insulating layer that insulates the first conductor layer and the second conductor layer, wherein the thickness of the insulating layer between the first conductor layer and the second conductor layer is The resin sheet according to any one of [1] to [5], which is for forming the insulating layer for a printed wiring board having a size of 6 µm or less.

[7] Thickness of the insulating layer between the first conductor layer and the second conductor layer, including a first conductor layer, a second conductor layer, and an insulating layer insulating the first conductor layer and the second conductor layer A printed wiring board having a thickness of 6 µm or less, wherein the insulating layer 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 comprising the printed wiring board according to [7].

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

1 is a partial cross-sectional view schematically showing an example of a printed wiring board.
Fig. 2 is a schematic diagram showing an example of a cross section of an inner-layer substrate for temporarily attaching components.

EMBODIMENT OF THE INVENTION Hereinafter, the resin sheet of this invention, the printed wiring board provided with the hardened|cured material of the resin composition layer of this resin sheet, and a semiconductor device are demonstrated in detail.

When 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, ( C) The inorganic filler is 50 mass % or more. In the present invention, the minimum melt viscosity of the resin composition layer at a frequency of 1 Hz and a strain of 1deg is 8000 poise or more, and the resin composition layer has a minimum melt viscosity of 8000 poise or less at a frequency of 1 Hz and a strain of 5deg. In addition, in this specification, "the lowest melt viscosity at a frequency of 1 Hz and a strain of 1deg" is sometimes described as "the lowest melt viscosity at a strain of 1deg", and "the lowest melt viscosity at a frequency of 1 Hz and a strain of 5deg" is It may be described as "the lowest melt viscosity at strain 5deg".

The resin composition layer contains (A) an epoxy resin, (B) a curing agent, and (C) an inorganic filler. The said resin composition layer is formed of the 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 hardening accelerator, a flame retardant, and an organic filler, as needed.

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

<(A) Epoxy resin>

The resin composition contains (A) an epoxy resin. (A) Examples of the epoxy resin include bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, bisphenol AF epoxy resin, dicyclopentadiene epoxy resin, trisphenol epoxy resin, and naphthol. Novolak type epoxy resin, phenol novolak type epoxy resin, tert-butyl-catechol type epoxy resin, naphthalene type epoxy resin, naphthol type epoxy resin, anthracene type epoxy resin, glycidylamine type epoxy resin, glycidyl ester type Epoxy resin, cresol novolak type epoxy resin, biphenyl type epoxy resin, linear aliphatic epoxy resin, butadiene structure epoxy resin, alicyclic epoxy resin, heterocyclic epoxy resin, spiro ring-containing epoxy resin, cyclohexanedimethanol type epoxy Resin, a naphthylene ether type epoxy resin, a trimethylol type epoxy resin, a tetraphenylethane type epoxy resin, etc. are mentioned. An epoxy resin may be used individually by 1 type, and may be used in combination of 2 or more type. It is preferable that (A) component is 1 or more types chosen from a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, and a biphenyl type epoxy resin.

It is preferable that the epoxy resin contains the epoxy resin which has two or more epoxy groups in 1 molecule. When the nonvolatile component of an epoxy resin is 100 mass %, it is preferable that at least 50 mass % or more is an epoxy resin which has two or more epoxy groups in 1 molecule. In addition, the epoxy resin preferably 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 deformation 5deg of the resin composition layer to improve embedding properties. Among them, it is more preferable to include a liquid epoxy resin having two or more epoxy groups in one molecule, and an epoxy resin having three or more epoxy groups in one molecule and being solid at a temperature of 20°C (hereinafter referred to as “solid epoxy resin”). do. As an epoxy resin, the resin composition layer which has outstanding flexibility is obtained by using a liquid epoxy resin and a solid epoxy resin together. Moreover, the breaking strength of the hardened|cured material of a resin composition layer also improves.

Examples of the liquid epoxy resin include bisphenol A epoxy resin, bisphenol F type epoxy resin, bisphenol AF type epoxy resin, naphthalene type epoxy resin, glycidyl ester type epoxy resin, glycidylamine type epoxy resin, phenol novolac type epoxy resin , an alicyclic epoxy resin having an ester skeleton, a cyclohexanedimethanol type epoxy resin, a glycidylamine type epoxy resin, and an epoxy resin having a butadiene structure are preferable, and a glycidylamine type epoxy resin, a bisphenol A type epoxy resin , a bisphenol F-type epoxy resin, a bisphenol AF-type epoxy resin, and a naphthalene-type epoxy resin are more preferable. As a specific example of a liquid epoxy resin, "HP4032", "HP4032D", "HP4032SS" (naphthalene type epoxy resin) manufactured by DIC Corporation, "828US" manufactured by Mitsubishi Chemical Co., Ltd., "jER828EL" (bisphenol A type) Epoxy resin), "jER807" (bisphenol F type epoxy resin), "jER152" (phenol novolak type epoxy resin), "YL7760" (bisphenol AF type epoxy resin), "630", "630LSD" (glycidylamine type epoxy resin), "ZX1059" (mixture of bisphenol A epoxy resin and bisphenol F epoxy resin) manufactured by Shin-Nippon Chemicals Co., Ltd., "YD-8125G" manufactured by Nippon-Nippon Chemicals Co., Ltd. ( Bisphenol A type epoxy resin), "EX-721" (glycidyl ester type epoxy resin) manufactured by Nagase Chemtex Co., Ltd., "Ceroxide 2021P" manufactured by Daicel Co., Ltd. (alicyclic having an ester skeleton) Epoxy resin), "PB-3600" (epoxy resin having a butadiene structure), "ZX1658", "ZX1658GS" (liquid 1,4-glycidylcyclohexane) manufactured by Shin-Nitetsu Chemical Co., Ltd., Mitsubishi Chemical "630LSD" (a glycidylamine type epoxy resin) manufactured by Co., Ltd., etc. are mentioned. These may be used individually by 1 type, and may be used in combination of 2 or more type.

Examples of the solid-state epoxy resin include a naphthalene-type tetrafunctional epoxy resin, a cresol novolak-type epoxy resin, a dicyclopentadiene-type epoxy resin, a trisphenol-type epoxy resin, a naphthol-type epoxy resin, a biphenyl-type epoxy resin, and a naphthylene ether-type epoxy resin. , anthracene-type epoxy resins, bisphenol A-type epoxy resins, and tetraphenylethane-type epoxy resins are preferable, and naphthalene-type tetrafunctional epoxy resins, naphthol-type epoxy resins, and biphenyl-type epoxy resins are more preferable. As a specific example of a solid-state epoxy resin, "HP4032H" (naphthalene type epoxy resin) manufactured by DIC Corporation, "HP-4700", "HP-4710" (naphthalene type tetrafunctional epoxy resin), "N-690" (cresol) Novolac type epoxy resin), "N-695" (cresol novolak 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 novolac-type epoxy resin), "NC3000H", "NC3000", "NC3000L", "NC3100" (biphenyl-type epoxy resin), New Nittetsu Sumikinka "ESN475V" (naphthalene-type epoxy resin), "ESN485" (naphthol novolak-type epoxy resin) manufactured by Chemical Corporation, "YX4000H", "YL6121" (biphenyl-type epoxy resin) manufactured by Mitsubishi Chemical Co., Ltd. , "YX4000HK" (bixylenol type epoxy resin), "YX8800" (anthracene type epoxy resin), "PG-100", "CG-500" manufactured by Osaka Chemical Co., Ltd., manufactured by Mitsubishi Chemical Co., Ltd. "YL7800" (fluorene type epoxy resin), "jER1010" (solid bisphenol A type epoxy resin) by Mitsubishi Chemical Co., Ltd., "jER1031S" (tetraphenylethane type epoxy resin), etc. are mentioned. Among these, it is solid by itself, but becomes liquid easily when mixed with other components when preparing the resin composition, and from the viewpoint of lowering the melt viscosity of the deformation 5deg of the resin composition layer and making the embedding property good, Mitsubishi Chemical Co., Ltd. ) manufactured "YX4000HK" (bixylenol type epoxy resin), etc. are preferable.

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

As an epoxy resin, when using a liquid epoxy resin and a solid epoxy resin together, these ratio (liquid epoxy resin:solid epoxy resin) is mass ratio, and the range of 1:0.5-1:25 is preferable. By setting the ratio of the liquid epoxy resin and the solid epoxy resin to such a range, i) proper adhesion is brought about when used in the form of a resin sheet, and ii) sufficient flexibility can be obtained when used in the form of a resin sheet. , handling is improved, and iii) a cured product having sufficient breaking strength can be obtained. From the viewpoint of the effects of i) to iii) above, the amount ratio of the liquid epoxy resin and the solid epoxy resin (liquid epoxy resin:solid epoxy resin) is, in terms of mass ratio, more preferably in the range of 1:1.0 to 1:20, 1 The range of :1.5 to 1:15 is more preferable.

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

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

The epoxy equivalent of an epoxy resin becomes like this. Preferably it is 50-5000, More preferably, it is 50-3000, More preferably, it is 80-2000, More preferably, it is 110-1000. By being in this range, the crosslinking density of the hardened|cured material of a resin composition layer becomes sufficient, and the insulating layer with small surface roughness can be brought about. In addition, an epoxy equivalent can be measured according to JISK7236, It is the mass of 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 an epoxy resin is the weight average molecular weight of polystyrene conversion measured by the gel permeation chromatography (GPC) method.

<(B) curing agent>

The resin composition contains (B) a curing agent. The curing agent is not particularly limited as long as it has a function of curing the epoxy resin, and for example, a phenol-based curing agent, a naphthol-based curing agent, an active ester-based curing agent, a benzoxazine-based curing agent, a cyanate ester-based curing agent, and a carbodiimide-based curing agent and the like. 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 phenolic hardening|curing agent is preferable, and a triazine skeleton containing phenolic hardening|curing agent is more preferable. Among them, 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.

As a specific example of a phenol type hardening|curing agent and a naphthol type hardening|curing agent, For example, Meiwakasei Co., Ltd. product "MEH-7700", "MEH-7810", "MEH-7851", Nihon Kayaku Co., Ltd. product " NHN", "CBN", "GPH", "SN170", "SN180", "SN190", "SN475", "SN485", "SN495", "SN-495V" manufactured by Shin-Nittetsu Sumikin Co., Ltd. "SN375", "SN395", "TD-2090", "LA-7052", "LA-7054", "LA-1356", "LA-3018-50P", "EXB-9500" manufactured by DIC Corporation ' and the like.

Although there is no restriction|limiting in particular as an active ester-type hardening|curing agent, Generally, ester groups with high reaction activity, such as phenol esters, thiophenol esters, N-hydroxyamine esters, and heterocyclic hydroxy compound esters, are two per molecule. The compounds having the above are preferably used. The active ester curing agent is preferably obtained by a condensation reaction of a carboxylic acid compound and/or a thiolcarboxylic acid compound with 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, 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 pyromellic 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, etc. are mentioned. Here, the "dicyclopentadiene-type diphenol compound" refers to a diphenol compound obtained by condensing two molecules of phenol to 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 phenol novolac, and a benzoyl product of phenol novolac. An active ester compound is preferable, and among these, the active ester compound containing a naphthalene structure, and the active ester compound containing a dicyclopentadiene type diphenol structure are more preferable. The "dicyclopentadiene type diphenol structure" represents a divalent structural unit consisting of phenylene-dicyclopentylene-phenylene.

Commercially available active ester curing agents are active ester compounds containing a dicyclopentadiene-type diphenol structure, such as "EXB9451", "EXB9460", "EXB9460S", "HPC-8000-65T", "HPC-8000H-65TM" ', "EXB-8000L-65TM" (manufactured by DIC Corporation), "EXB9416-70BK" (manufactured by DIC Corporation) as an active ester compound containing a naphthalene structure, an active ester containing an acetylated product of phenol novolac "DC808" (manufactured by Mitsubishi Chemical Co., Ltd.) as a compound, "YLH1026" (manufactured by Mitsubishi Chemical Co., Ltd.) as an active ester compound containing a benzoyl product of phenol novolac, an active ester that is an acetylated product of phenol novolac “DC808” (manufactured by Mitsubishi Chemical Co., Ltd.) as a curing agent, “YLH1026” (manufactured by Mitsubishi Chemical Co., Ltd.) and “YLH1030” (Mitsubishi Chemical Co., Ltd.) as an active ester curing agent that is a benzoyl product of phenol novolac. ), "YLH1048" (manufactured by Mitsubishi Chemical Co., Ltd.), and the like.

As a specific example of a benzoxazine type hardening|curing agent, "HFB2006M" by Showa Kobunshi Co., Ltd., "P-d" by Shikoku Chemical Co., Ltd., and "F-a" are mentioned.

Examples of the cyanate ester curing agent include bisphenol A dicyanate, polyphenol cyanate, oligo (3-methylene-1,5-phenylene cyanate), and 4,4'-methylenebis (2,6- Dimethylphenyl cyanate), 4,4'-ethylidenediphenyldicyanate, hexafluorobisphenol A dicyanate, 2,2-bis(4-cyanate)phenylpropane, 1,1-bis(4- Cyanatephenylmethane), bis(4-cyanate-3,5-dimethylphenyl)methane, 1,3-bis(4-cyanatephenyl-1-(methylethylidene))benzene, bis(4-cya Bifunctional cyanate resins such as natephenyl)thioether and bis(4-cyanatephenyl)ether, polyfunctional cyanate resins derived from phenol novolac and cresol novolak, etc., in which these cyanate resins are partially triazined A prepolymer etc. are mentioned. As a specific example of a cyanate ester type hardening|curing agent, "PT30" and "PT60" (phenol novolak type polyfunctional cyanate ester resin) manufactured by Ron Japan Co., Ltd., "ULL-950S" (polyfunctional cyanate ester resin), "BA230", "BA230S75" (a prepolymer in which a part or all of bisphenol A dicyanate was triazined and became a trimer) etc. are mentioned.

As a specific example of a carbodiimide type hardening|curing agent, "V-03", "V-07" by Nisshinbo Chemical Co., Ltd., etc. are mentioned.

(B) As a component, it is preferable that it is 1 or more types chosen 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. In addition, the active ester curing agent is more preferable as the curing agent from the viewpoint of lowering the melt viscosity of the modified 5deg to improve embedding properties.

The amount ratio of the epoxy resin and the curing agent is a ratio of [the total number of epoxy groups in the epoxy resin]: [the total number of reactive groups in the curing agent], preferably in the range of 1:0.01 to 1:2, and 1:0.015 to 1:1.5 is more preferable, and 1:0.02 to 1:1 is still more preferable. Here, the reactive group of a hardening|curing agent is an active hydroxyl group, an active ester group, etc., and it changes with the kind of hardening|curing agent. In addition, the total number of epoxy groups of the epoxy resin is the value obtained by dividing the solid content 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 a value obtained by dividing the solid content mass of each curing agent by the reactor equivalent is the sum of all curing agents. By making the 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. Moreover, although there is no restriction|limiting in particular as for a minimum, 2 mass % or more is preferable.

<(C) Inorganic filler>

The resin composition contains (C) an inorganic filler. Although 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, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, magnesium oxide, boron nitride, aluminum nitride, manganese nitride, aluminum borate, strontium carbonate, strontium titanate, calcium titanate, magnesium titanate, bismuth titanate, titanium oxide, zirconium oxide , barium titanate, barium zirconate titanate, barium zirconate, calcium zirconate, zirconium phosphate, and zirconium tungsten phosphate. Among these, silica is particularly suitable. Examples of the silica include amorphous silica, fused silica, crystalline silica, synthetic silica, and hollow silica. Moreover, as a silica, spherical silica is preferable. 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 is 0.35 µm or less from the viewpoint of improving the thin film insulation when the inorganic filler is highly filled, and increasing the minimum melt viscosity in deformation 1deg of the resin composition layer to increase the flatness. is preferably 0.32 µm or less, still more preferably 0.3 µm or less, and still more preferably 0.29 µm or less. From the viewpoint of improving the 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 still more preferably 0.065 µm or more. As a commercial item of the inorganic filler which has such an average particle diameter, For example, Denki Chemical Co., Ltd. product "UFP-30", "UFP-40", Shin-Nittetsu Sumikin Materials Co., Ltd. product "SPH516-05" ' and the like.

The average particle diameter of the inorganic filler can be measured by a laser diffraction/scattering method based on the Mie scattering theory. Specifically, it can measure by creating the particle size distribution of an inorganic filler on a volume basis with a laser diffraction scattering type particle size distribution measuring apparatus, and making the intermediate diameter into an average particle diameter. As a measurement sample, what disperse|distributed the inorganic filler in methyl ethyl ketone by ultrasonication can be used preferably. As a laser diffraction scattering type particle size distribution analyzer, Shimadzu Corporation "SALD-2200" etc. 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, still more preferably 41 m 2 , from the viewpoint of lowering the minimum melt viscosity of the resin composition layer at strain 5deg. /g or less. The lower limit of the specific surface area is preferably 1 m 2 /g or more, more preferably 2 m 2 /g or more, still more preferably 5 m 2 /g or more from the viewpoint of maintaining the 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 device (manufactured by Mountec Co., Ltd., Macsorb HM-1210).

From the viewpoint of improving the 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 still more preferably 5 g/cm 3 or less. The lower limit of the said true density becomes like this. Preferably it is 1 g/cm<3> or more, More preferably, it is 1.5 g/cm<3> or more, More preferably, it is 2.0 g/cm<3> or more. True density can be measured using, for example, a micro-ultrapicnometer (manufactured by Quantachrome Instruments Japan, MUPY-21T).

It is preferable that the inorganic filler is surface-treated with at least 1 or more types of surface treatment agents, such as a silane coupling agent, an alkoxysilane compound, and an organosilazane compound, from a viewpoint of improving moisture resistance and dispersibility. These may be oligomers. Examples of the surface treatment agent include aminosilane coupling agents, epoxysilane coupling agents, silane coupling agents such as mercaptosilane coupling agents, alkoxysilane compounds, organosilazane compounds, titanate coupling agents, and the like. As a commercial item of a surface treatment agent, For example, Shin-Etsu Chemical Co., Ltd. "KBM403" (3-glycidoxypropyl trimethoxysilane), Shin-Etsu Chemical Co., Ltd. product "KBM803" (3-mercapto) Propyltrimethoxysilane), Shin-Etsu Chemical Co., Ltd. "KBE903" (3-aminopropyltriethoxysilane), Shin-Etsu Chemical Co., Ltd. "KBM573" (N-phenyl-3-aminopropyltri methoxysilane), Shin-Etsu Chemical Co., Ltd. "SZ-31" (hexamethyldisilazane), Shin-Etsu Chemical Co., Ltd. "KBM103" (phenyltrimethoxysilane), Shin-Etsu Chemical Co., Ltd. ( Note) manufactured "KBM-4803" (long-chain epoxy type silane coupling agent) etc. are mentioned. A surface treating agent may be used individually by 1 type, and may be used in combination of 2 or more type.

The grade of the surface treatment by a surface treating agent can be evaluated by the amount of carbon per unit area of an inorganic filler. From the viewpoint of improving the dispersibility of the inorganic filler, the amount of carbon per unit surface area of the inorganic filler is preferably 0.02 mg/m 2 or more, more preferably 0.1 mg/m 2 or more, and still more preferably 0.15 mg/m 2 or more. On the other hand, from the viewpoint of suppressing an increase in the melt viscosity of the resin varnish and the melt viscosity in the sheet form, 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 still more preferable. .

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

When content (filling amount) of the inorganic filler in a resin composition makes the nonvolatile component in a resin composition 100 mass %, it is 50 mass % or more. From a viewpoint of improving the thickness stability of a resin composition layer and suppressing reflow curvature, 55 mass % or more is preferable and, as for content of an inorganic filler, 60 mass % or more is more preferable. The upper limit of content of the inorganic filler in a resin composition becomes like this from a viewpoint of the improvement of thin film insulation, Preferably it is 85 mass % or less, More preferably, it is 80 mass % or less.

<(D) Thermoplastic resin>

The resin sheet of the present invention may further contain (D) a thermoplastic resin. Thereby, it is possible to increase the melt viscosity of the deformation 1deg to make it easier to adjust the flatness.

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, polyether ether ketone resin, and polyester resin are mentioned, A phenoxy resin is preferable. A thermoplastic resin may be used individually by 1 type, or may be used in combination of 2 or more type.

The range of 8,000-70,000 is preferable, as for the weight average molecular weight of polystyrene conversion of a thermoplastic resin, the range of 10,000-60,000 is more preferable, The range of 20,000-60,000 is still more preferable. The weight average molecular weight in terms of polystyrene of the thermoplastic resin is measured by a gel permeation chromatography (GPC) method. Specifically, the weight average molecular weight of the thermoplastic resin in terms of polystyrene is LC-9A/RID-6A manufactured by Shimadzu Corporation as a measuring device and Shodex K-800P/K manufactured by Showa Denko Corporation 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, novolak skeleton, biphenyl skeleton, fluorene skeleton, dicyclopentadiene skeleton, norbornene skeleton, naphthalene skeleton , an anthracene skeleton, an adamantane skeleton, a terpene skeleton, and a phenoxy resin having at least one skeleton selected from the group consisting of trimethylcyclohexane skeleton. Any one of functional groups, such as a phenolic hydroxyl group and an epoxy group, may be sufficient as the terminal of a phenoxy resin. A phenoxy resin may be used individually by 1 type, and may be used in combination of 2 or more type. As a specific example of a phenoxy resin, Mitsubishi Chemical Co., Ltd. product "1256" and "4250" (both bisphenol A skeleton containing phenoxy resin), "YX8100" (bisphenol S skeleton containing phenoxy resin), and "YX6954" (Bisphenol acetophenone skeleton-containing phenoxy resin), in addition, "FX280" and "FX293" manufactured by Shin-Nittetsu Chemical Co., Ltd., "YX6954BH30" and "YX7553" manufactured by Mitsubishi Chemical Co., Ltd. , "YX7553BH30", "YL7769BH30", "YL6794", "YL7213", "YL7290", "YL7482", etc. are mentioned.

As polyvinyl acetal resin, polyvinyl formal resin and polyvinyl butyral resin are mentioned, for example, Polyvinyl butyral resin is preferable. As a specific example of polyvinyl acetal resin, "Electron butyral 4000-2", "Electron Butyral 5000-A", and "Electron Butyral 6000-C" manufactured by Denki Chemical Co., Ltd. are, for example, polyvinyl acetal resin. , "Telephone Butyral 6000-EP", Sekisui Chemical Co., Ltd. S-Rec BH series, BX series (such as BX-5Z), KS series (such as KS-1), BL series, BM series and the like.

As a specific example of polyimide resin, "Ricacoat SN20" and "Ricacoat PN20" by Shin-Nippon Rica Co., Ltd. are mentioned. As a specific example of the polyimide resin, furthermore, a linear polyimide obtained by reacting a difunctional hydroxyl-terminated polybutadiene, a diisocyanate compound, and a tetrabasic acid anhydride (a polyimide described in Japanese Patent Application Laid-Open No. 2006-37083); Modified polyimides, such as polysiloxane skeleton containing polyimide (the polyimide described in Unexamined-Japanese-Patent No. 2002-12667, Unexamined-Japanese-Patent No. 2000-319386, etc.) are mentioned.

As a specific example of polyamideimide resin, "Viromax HR11NN" and "Viromax HR16N" by Toyobo Seki Co., Ltd. are mentioned. Specific examples of the polyamideimide resin include modified polyamideimides such as "KS9100" and "KS9300" (polyamideimide containing polysiloxane skeleton) manufactured by Hitachi Chemical Co., Ltd.

As a specific example of polyether sulfone resin, Sumitomo Chemical Co., Ltd. product "PES5003P" etc. are mentioned.

As a specific example of polysulfone resin, Solvay Advanced Polymers Co., Ltd. product polysulfone "P1700", "P3500", etc. are mentioned.

As a specific example of polyphenylene ether resin, Mitsubishi Chemical Co., Ltd. oligophenylene ether styrene resin "OPE-2St1200", "OPE-2St2200", SABIC product "NORYL SA90", etc. are mentioned.

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

When a resin composition contains a thermoplastic resin, content of a thermoplastic resin becomes like this. Preferably it is 0.5 mass % - 10 mass %, More preferably, it is 0.6 mass % - 6 mass %, More preferably, it is 0.7 mass % - 5 mass %. am.

<(E) curing accelerator>

The resin sheet of this invention may contain the (E) hardening accelerator further.

Examples of the curing accelerator include phosphorus-based curing accelerators, amine-based curing accelerators, imidazole-based curing accelerators, guanidine-based curing accelerators, metal-based curing accelerators, organic peroxide curing accelerators, and the like, phosphorus-based curing accelerators and amine-based curing accelerators. An accelerator, an imidazole type hardening accelerator, and a metal type hardening accelerator are preferable, and an amine type hardening accelerator, an imidazole type hardening accelerator, and a metal type hardening 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 the phosphorus-based curing accelerator include triphenylphosphine, phosphonium borate compound, tetraphenylphosphonium tetraphenylborate, n-butylphosphonium tetraphenylborate, tetrabutylphosphoniumdecanoate, (4-methylphenyl)triphenyl Phosphonium thiocyanate, tetraphenyl phosphonium thiocyanate, butyl triphenyl phosphonium thiocyanate, etc. are mentioned, Triphenyl phosphine and tetrabutyl phosphonium decanoate are preferable.

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

Examples of the imidazole-based curing accelerator include 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, and 2-ethyl-4-methyl. Imidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methyl Midazole, 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'-undecyl Imidazolyl-(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-triazineisocyanuric acid adduct, 2-phenylimidazoleisocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2,3-dihydro-1H-pyrrolo[1,2-a ]Imidazole compounds such as benzimidazole, 1-dodecyl-2-methyl-3-benzylimidazolium chloride, 2-methylimidazoline, and 2-phenylimidazoline, and a mixture of an imidazole compound and an epoxy resin A duct body is mentioned, 2-ethyl- 4-methylimidazole and 1-benzyl- 2-phenylimidazole are preferable.

As an imidazole-type hardening accelerator, you may use a commercial item, For example, Mitsubishi Chemical Co., Ltd. product "P200-H50", Shikoku Chemical Co., Ltd. product "1B2PZ", etc. are mentioned.

Examples of the guanidine-based curing accelerator include dicyandiamide, 1-methylguanidine, 1-ethylguanidine, 1-cyclohexylguanidine, 1-phenylguanidine, 1-(o-tolyl)guanidine, dimethylguanidine, and diphenylguanidine. , trimethylguanidine, tetramethylguanidine, pentamethylguanidine, 1,5,7-triazabicyclo[4.4.0]deca-5-ene, 7-methyl-1,5,7-triazabicyclo[4.4.0] Deca-5-ene, 1-methylbiguanide, 1-ethylbiguanide, 1-n-butylbiguanide, 1-n-octadecylbiguanide, 1,1-dimethylbiguanide, 1, 1-diethylbiguanide, 1-cyclohexylbiguanide, 1-allylbiguanide, 1-phenylbiguanide, 1-(o-tolyl)biguanide, and the like, and dicyandiamide; 1,5,7-triazabicyclo[4.4.0]deca-5-ene is preferred.

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

Examples of the organic peroxide curing accelerator include dicumyl peroxide, cyclohexanone peroxide, tert-butyl peroxybenzoate, methyl ethyl ketone peroxide, dicumyl peroxide, tert-butylcumyl peroxide, di-tert-butyl Peroxide, diisopropylbenzene hydroperoxide, cumene hydroperoxide, tert-butyl hydroperoxide, etc. are mentioned. As an organic peroxide type|system|group hardening accelerator, you may use a commercial item, for example, "Percumyl D" manufactured by Nichiyu Corporation, etc. are mentioned.

Although content of the hardening accelerator in a resin composition is not specifically limited, When an epoxy resin and the nonvolatile component of a hardening|curing agent are 100 mass %, 0.01 mass % - 3 mass % are preferable. By setting it as this range, it can be made easy to adjust the melt viscosity of deformation|transformation 1deg and 5deg.

<(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.

As a flame retardant, you may use a commercial item, For example, Sanko Co., Ltd. product "HCA-HQ", Daihachi Chemical Industry Co., Ltd. product "PX-200", etc. are mentioned.

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

<(G) Organic Filling Material>

The resin composition may contain (G) an organic filler. As an organic filler, you may use arbitrary organic fillers which can be used when forming the insulating layer of a printed wiring board, For example, a rubber particle, polyamide microparticles|fine-particles, a silicone particle, etc. are mentioned.

A commercial item may be used as a rubber particle, For example, "EXL2655" by Dow Chemical Corporation, "AC3401N" by Aika Kogyo Co., Ltd., "AC3816N", etc. are mentioned.

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, still more preferably 0.3% by mass to 5% by mass, Or 0.5 mass % - 3 mass %.

<(H) Other additives>

The resin composition may further contain other additives as necessary. Examples of such other additives include organometallic compounds such as organocopper compounds, organozinc compounds and organocobalt compounds, and thickeners, defoamers, leveling agents, and adhesion properties. and resin additives such as imparting agents and colorants.

The resin sheet of this invention brings about the insulating layer excellent in thin film insulation while suppressing reflow curvature. 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 a resin sheet (printing) for forming an interlayer insulating layer of a printed wiring board. It can be used more suitably as resin sheet for interlayer insulating layers of a wiring board). Further, for example, in a printed wiring board having a first conductor layer, a second conductor layer, and an insulating layer provided between the first conductor layer and the second conductor layer, an insulating layer is formed by using the resin sheet of the present invention. , while the thickness of the insulating layer between the first and second conductor layers is 6 µm or less (preferably 5.5 µm or less, more preferably 5 µm or less), the insulating performance can be excellent. In one suitable embodiment, the resin sheet of this invention contains a 1st conductor layer, a 2nd conductor layer, and the insulating layer which insulates the 1st conductor layer and the 2nd conductor layer, The 1st conductor layer and It is for insulating layer formation of the printed wiring board whose thickness of the insulating layer between 2nd conductor layers is 6 micrometers or less.

[Resin Sheet]

The resin sheet of this invention is equipped with a resin composition layer, The resin composition layer is formed from a resin composition.

From a viewpoint of thickness reduction of a printed wiring board, the thickness of a resin composition layer becomes like this. Preferably it is 15 micrometers or less, More preferably, it is 12 micrometers or less, More preferably, it is 10 micrometers or less, More preferably, it is 8 micrometers or less. Although the lower limit of the thickness of a resin composition layer is not specifically limited, Usually, it can be 1 micrometer or more, 1.5 micrometers or more, 2 micrometers or more.

As one embodiment of the present invention, a resin sheet includes a support and a resin composition layer bonded on the support. As a support body, the film which consists of a plastic material, metal foil, and a release paper are mentioned, for example, The film which consists of a plastic material, and metal foil are preferable.

When a film made of a plastic material is used as the support, the plastic material is, for example, polyethylene terephthalate (hereinafter sometimes abbreviated as “PET”), polyethylene naphthalate (hereinafter sometimes abbreviated as “PEN”). ) such as polyester, polycarbonate (hereinafter sometimes abbreviated as "PC"), acrylic such as polymethyl methacrylate (PMMA), cyclic polyolefin, triacetyl cellulose (TAC), polyether sulfide (PES), Polyether ketone, polyimide, etc. are mentioned. Among them, 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 (eg, tin, chromium, silver, magnesium, nickel, zirconium, silicon, titanium, etc.) You can also use gourd.

The support may be subjected to a mat treatment, a corona treatment, or an 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 mold release layer which has a mold release layer on the surface to join with a resin composition layer. As a mold release agent used for the mold release layer of a support body with a mold release layer, 1 or more types of mold release agents are mentioned from the group which consists of an alkyd resin, a polyolefin resin, a urethane resin, and a silicone resin, for example. A commercially available support with a release layer may be used, for example, "SK-1", "AL-5", and "AL- 7", Toray Co., Ltd. product "Lumira T6AM", "Lumira R80", etc. are mentioned.

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. Moreover, when using a support body with a mold release layer, it is preferable that the thickness of the whole support body with a mold release layer is the said range.

It can be manufactured by preparing a resin sheet, for example, a resin varnish in which a resin composition is dissolved in an organic solvent, applying this resin varnish to a support using a die coater or the like, and drying it to form a resin composition layer.

Examples of the organic solvent include ketones such as acetone, methyl ethyl ketone (MEK) and cyclohexanone; acetate esters such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate and carbitol acetate; carbitols such as cellosolve and butylcarbitol; aromatic hydrocarbons such as toluene and xylene; and 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 well-known methods, such as heating and hot-air spraying. Although drying conditions are not specifically limited, Content of the organic solvent in a resin composition layer is 10 mass % or less, Preferably it is made to dry so that it may become 5 mass % or less. Although it varies depending on the boiling point of the organic solvent in the resin varnish, for example, when using a resin varnish containing 30% by mass to 60% by mass of an organic solvent, by drying at 50°C to 150°C for 3 minutes to 10 minutes, A resin composition layer can be formed.

In the resin sheet, a protective film conforming 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 on the opposite side to the support). Although the thickness of a protective film is not specifically limited, For example, it is 1 micrometer - 40 micrometers. By laminating|stacking a protective film, adhesion of dust, etc. to the surface of a resin composition layer, and a flaw can be prevented. The resin sheet can be wound and stored in a roll shape. When a resin sheet has a protective film, it becomes usable by peeling off a protective film.

The minimum melt viscosity of the resin composition layer in deformation 1deg is 8000 poise (800 Pa s) or more, and 8500 poise (850 Pa s) or more from the viewpoint of suppressing movement of the resin layer and improving flatness in a thermosetting process etc. It is preferable that it is 9000 poise (900 Pa.s) or more, and it is more preferable that it is 10000 poise (1000 Pa.s) or more. The upper limit of the minimum melt viscosity in deformation 1deg 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, More preferably, it is 13000 poise (1300 Pa.s) or less.

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

The minimum melt viscosity of a resin composition layer means the minimum viscosity which a resin composition layer shows when resin of a resin composition layer melts. Specifically, when the resin composition layer is heated at a constant temperature increase rate to melt the resin, in the initial stage, the melt viscosity decreases with the temperature rise, and then, when it exceeds a certain level, the melt viscosity increases with the temperature rise. The lowest melt viscosity refers to the melt viscosity of this minimum point. The minimum melt viscosity of the resin composition layer can be measured by a dynamic viscoelasticity method, for example, according to the method described in <Measurement of minimum melt viscosity> mentioned later. In addition, "the lowest melt viscosity at strain 1deg" is "the lowest melt viscosity that can be obtained by performing dynamic viscoelasticity measurement under the conditions of a frequency of 1 Hz and strain 1deg", and "the lowest melt viscosity at strain 5deg" is "frequency 1" It is the lowest melt viscosity obtainable by performing dynamic viscoelasticity measurement under the conditions of Hz and strain 5deg."

[Cured material]

The thermosetting conditions of the resin composition layer of the resin sheet of this invention are not specifically limited, For example, when forming the insulating layer of the printed wiring board mentioned later, you may use the conditions normally employ|adopted. In addition, before thermosetting a resin composition layer, you may perform preliminary heating, and heating in thermosetting conditions may be performed multiple times including preliminary heating. As an example of thermosetting conditions, first, a resin composition layer is thermosetted at 100 degreeC for 30 minutes, then 180 degreeC for 30 minutes, and also 200 degreeC for 90 minutes.

A cured product of the resin composition layer of the resin sheet of the present invention (for example, a cured product obtained by thermosetting 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) It exhibits a good average coefficient of linear thermal expansion (CTE) at 25 to 150°C. That is, an insulating layer exhibiting a good average coefficient of linear thermal expansion is obtained. The average coefficient of linear thermal expansion at 25°C to 150°C is preferably 30 ppm/°C or less, more preferably 28 ppm/°C or less, still more preferably 26 ppm/°C from the viewpoint that the amount of reflow warpage of the cured product can be reduced. is below. Although it does not specifically limit about a minimum, It is 0.1 ppm/degreeC or more. The measuring method of the average coefficient of linear thermal expansion can be measured according to the method as described in <Measurement of the average coefficient of linear thermal expansion (CTE) of the hardened|cured material of a resin sheet> mentioned later.

A cured product obtained by thermosetting the resin composition layer of the resin sheet of the present invention (for example, a cured product obtained by thermosetting the resin composition layer at 100° C. for 30 minutes and then at 180° C. for 30 minutes) is 130° C.; It shows good insulation resistance value even after 200 hours under 85RH%, 3.3V application environment. That is, an insulating layer exhibiting a good insulation resistance value is obtained. The upper limit of the insulation resistance value is preferably 10 ¹² Ω or less, more preferably 10 ¹¹ Ω or less, still more preferably 10 ¹⁰ Ω or less. About the lower limit, Preferably it is 10 ⁷ Ω or more, More preferably, it is 10 ⁸ Ω or more. The measurement of an insulation resistance value can be measured according to the method as described in <Evaluation of insulation reliability> mentioned later.

The present invention also includes 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 1deg, and a minimum melt viscosity of 8000 poise or less at a frequency of 1 Hz and a strain of 5deg. The hardened|cured material of this invention has the structure similar to the hardened|cured material of the resin composition layer of the resin sheet of this invention. The curing conditions of the resin composition layer for forming the cured product are the same as the curing conditions of the resin sheet of the present invention. Preferred average coefficient of linear thermal expansion in the cured product of the present invention (for example, a cured product obtained by thermosetting 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) A range is the same as that of the hardened|cured material of the above-mentioned resin sheet. Moreover, it is the same as that of the hardened|cured material of the resin sheet mentioned above also about the preferable range of the insulation resistance value in the hardened|cured material of this invention.

[Printed wiring board, manufacturing method of printed wiring board]

The printed wiring board of this invention contains the insulating layer formed with the hardened|cured material of the resin composition layer of the resin sheet of this invention, a 1st conductor layer, and a 2nd conductor layer. The printed wiring board of this invention may be equipped with the hardened|cured material of this 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 by the hardened|cured material of the resin composition layer of the resin sheet of this invention is excellent in thin film insulation, it is excellent in insulation even if the thickness of the insulating layer between the 1st and 2nd conductor layers is 6 micrometers or less.

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, still more preferably 5 µm or less. Although it does not specifically limit about a lower limit, It can be set as 0.1 micrometer or more. The thickness of the insulating layer between the first and second conductor layers refers to the main surface 51 of the first conductor layer 5 and the main surface ( 61) refers to the thickness t1 of the insulating layer 7 between them. The first and second conductor layers are conductive 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 1st and 2nd conductor layers can be measured according to the method as described in <Insulation reliability evaluation, measurement of the thickness of the insulating layer between conductor layers> mentioned later.

Moreover, the thickness t2 of the whole insulating layer becomes like this. Preferably it is 20 micrometers or less, More preferably, it is 15 micrometers or less, More preferably, it is 12 micrometers or less. Although it does not specifically limit about a lower limit, It can be set as 1 micrometer 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) step of laminating the resin composition layer of the resin sheet on the inner layer substrate so as to be bonded to the inner layer substrate

(II) Step of thermosetting the resin composition layer to form an insulating layer

The "inner-layer substrate" used in step (I) refers to a substrate such as a glass epoxy substrate, a metal substrate, a polyester substrate, a polyimide substrate, a BT resin substrate, a thermosetting polyphenylene ether substrate, or one side of the substrate ( It refers to a circuit board in which a patterned conductor layer (circuit) is formed on both sides or both sides. In addition, when manufacturing a printed wiring board, an insulating layer and/or a conductor layer must be additionally formed, and the inner circuit board of an intermediate product is also included in the "inner layer board|substrate" referred to in the present invention. When the printed wiring board is a circuit board with a built-in component, an inner-layer board having a built-in component can be used.

Lamination of the inner layer substrate and the resin sheet can be performed, for example, by thermocompression bonding the resin sheet to the inner layer substrate from the support side. As a member (hereinafter also referred to as "thermal compression member") for heat-bonding the resin sheet to the inner layer substrate, for example, a heated metal plate (SUS head plate, etc.) or a metal roll (SUS roll) or the like is exemplified. In addition, it is preferable not to press the thermocompression-bonding member directly to the resin sheet, but to press through an elastic material, such as a heat-resistant rubber, so that the resin sheet may fully follow the surface unevenness|corrugation of an inner-layer board|substrate.

You may perform lamination|stacking of an inner-layer board|substrate and a resin sheet by the vacuum lamination method. In the vacuum lamination method, the thermocompression compression temperature is preferably in the range of 60°C to 160°C, more preferably 80°C to 140°C, and the thermocompression compression pressure is preferably 0.098 MPa to 1.77 MPa, more preferably 0.29 MPa. to 1.47 MPa, and the thermocompression 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 of a pressure of 26.7 hPa or less.

Lamination can be performed with a commercially available vacuum laminator. As a commercially available vacuum laminator, the vacuum pressurization laminator manufactured by Meiki Seisakusho Co., Ltd., a vacuum applicator manufactured by Nikko Materials Co., Ltd., etc. are mentioned, for example.

After lamination, under normal pressure (under atmospheric pressure), for example, by pressing the thermocompression-bonding member from the support body side, you may perform the smoothing process of the laminated|stacked resin sheet. The press conditions of the smoothing process can be made into the same conditions as the thermocompression-bonding conditions of the said lamination|stacking. A smoothing process can be implemented with a commercially available laminator. In addition, you may perform lamination|stacking and a smoothing process continuously using the said commercially available vacuum laminator.

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

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

The thermosetting conditions of a resin composition layer are not specifically limited, When forming the insulating layer of a printed wiring board, you may use the conditions normally employ|adopted.

For example, the thermosetting conditions of the resin composition layer also vary depending on the type of resin composition, etc., but 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 The range of 200 degreeC) and hardening time can be made into the range of 5 minutes - 120 minutes (preferably 10 minutes - 100 minutes, More preferably, 15 minutes - 90 minutes).

Before thermosetting a resin composition layer, you may preheat a resin composition layer at temperature lower than hardening temperature. For example, prior to thermosetting the resin composition layer, at a temperature of 50°C or more and less than 120°C (preferably 60°C or more and 110°C or less, more preferably 70°C or more and 100°C or less), the resin composition layer is heated to 5 You may preheat for more than a minute (preferably for 5 minutes - 150 minutes, More preferably, for 15 minutes - 120 minutes).

When manufacturing a printed wiring board, you may further perform (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 that are used for manufacturing a printed wiring board. Also, when the support is removed after the step (II), the removal of the support is performed between the steps (II) and (III), between the steps (III) and (IV), or between the steps (IV) and the step (V). ) may be performed between In addition, if necessary, the formation of the insulating layer and the conductor layer in the steps (II) to (V) may be repeated to form a multilayer wiring board. In this case, the thickness of the insulating layer (t1 in FIG. 1) between the respective conductor layers is preferably within the above range.

Step (III) is a step of drilling 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 and the like. You may determine the dimension and shape of a hole suitably according to the design of a printed wiring board.

Process (IV) is a process of roughening an insulating layer. The order and conditions of a roughening process are not specifically limited, In forming the insulating layer of a printed wiring board, the well-known order and conditions normally used can be employ|adopted. For example, the insulating layer can be roughened by performing the swelling process by a swelling liquid, the roughening process by an oxidizing agent, and the neutralization process by a neutralizing liquid in this order. Although it does not specifically limit as a swelling liquid, An alkali solution, surfactant solution, etc. are mentioned, Preferably it is an alkali solution, As said alkali solution, sodium hydroxide solution and potassium hydroxide solution are more preferable. As a commercially available swelling liquid, "Swelling Deep Security P", "Swelling Deep Security SBU" manufactured by Atotech Japan Co., Ltd., etc. are mentioned, for example. Although the swelling process by a swelling liquid is not specifically limited, For example, it can perform by immersing an insulating layer in 30 degreeC - 90 degreeC swelling liquid for 1 minute - 20 minutes. From the viewpoint of suppressing the swelling of the resin of the insulating layer to an appropriate level, it is preferable to immerse the insulating layer in a swelling solution 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 permanganic acid 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°C to 80°C for 10 minutes to 30 minutes. Moreover, as for the density|concentration of the permanganate in an alkaline permanganic acid solution, 5 mass % - 10 mass % are preferable. As a commercially available oxidizing agent, alkaline permanganic acid solutions, such as "Concentrate Compact CP" by Atotech Japan Co., Ltd. product, and "Dojin Solution Securigans P", are mentioned, for example. Moreover, an acidic aqueous solution is preferable as a neutralizing liquid, As a commercial item, "Reduction Solution Securigant P" manufactured by Atotech Japan Co., Ltd. is mentioned, for example. The treatment with the neutralizing solution can be performed by immersing the treated surface subjected to the roughening treatment with the oxidizing agent in a neutralizing solution at 30°C to 80°C for 5 minutes to 30 minutes. The method of immersing the target object in which the roughening process by an oxidizing agent was made|formed from points, such as workability|operativity, in the neutralization liquid of 40 degreeC - 70 degreeC for 5 minutes - 20 minutes is preferable.

In one embodiment, the arithmetic mean roughness (Ra) of the surface of the insulating layer after roughening is preferably 400 nm or less, more preferably 350 nm or less, still more preferably 300 nm or less, 250 nm or less, 200 nm or less. or less, 150 nm or less, or 100 nm or less. The arithmetic mean roughness (Ra) of the surface of the insulating layer can be measured using a non-contact type surface roughness meter. As a specific example of a non-contact type surface roughness meter, "WYKO NT3300" by a BCoin Instruments company is mentioned.

Process (V) is a process of forming a conductor layer. When no conductor layer is formed on the inner-layer substrate, step (V) is a step of forming a first conductor layer, and when a 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 a conductor layer is not specifically limited. In a suitable embodiment, the conductor layer comprises at least one metal selected from the group consisting of gold, platinum, palladium, silver, copper, aluminum, cobalt, chromium, zinc, nickel, titanium, tungsten, iron, tin and indium. do. The conductor layer may be a single metal layer or an alloy layer, and the alloy layer is, for example, an alloy of two or more metals selected from the group described above (for example, a nickel-chromium alloy, a copper-nickel alloy, and a copper-titanium alloy) layers formed from Among them, from the viewpoint of versatility of conductor layer formation, cost, ease of patterning, etc., a single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver or copper, or a nickel-chromium alloy, a copper-nickel alloy, An alloy layer of a copper/titanium alloy is preferable, a single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver or copper, or an alloy layer of a nickel/chromium alloy is more preferable, and the single metal layer of copper is more preferable more preferably.

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 a nickel-chromium alloy.

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

In one embodiment, the conductor layer may be formed by plating. For example, a conductor layer having a desired wiring pattern can be formed by plating on the surface of the insulating layer by a conventionally known technique such as a semi-additive method or a full additive method. Hereinafter, the example in which a conductor layer is formed by the semiadditive method is shown.

First, a plating seed layer is formed on the surface of the insulating layer by electroless plating. Then, a mask pattern for exposing a portion of the plating seed layer is formed on the formed plating seed layer to correspond to a desired wiring pattern. After forming a metal layer by electrolytic plating on the exposed plating seed layer, the mask pattern is removed. Thereafter, the unnecessary plating seed layer is removed by etching or the like, and a conductor layer having a desired wiring pattern can be formed.

Since the resin sheet of this invention produces an insulating layer with good component embedding property, it can use suitably also when a printed wiring board is a component built-in circuit board.

As a manufacturing method of such a component-embedded circuit board,

(i) an inner-layer substrate having opposing first and second main surfaces and having a cavity penetrating between the first and second main surfaces, a temporary attachment material bonded to the second main surface of the inner-layer substrate; A step of preparing a component temporarily attaching inner layer substrate including a component temporarily attached with a temporary attaching material inside the cavity;

(ii) 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) laminating the resin sheet so that the resin composition layer is bonded to the second main surface of the inner-layer substrate; and

(v) The process of thermosetting a resin composition layer is included.

As an example is shown in FIG. 2 , an inner-layer substrate 100 (also referred to as a “cavity substrate”) has first and second main surfaces 11 and 12 facing each other, and the first and second main surfaces are the first and second main surfaces. An inner-layer substrate 1 having a cavity 1a passing therethrough, a temporary attachment material 2 bonded to the second main surface 12 of the inner-layer substrate 1, and a cavity 1a of the inner-layer substrate 1 ) includes a part 3 temporarily attached by a temporary attachment material 2 on the inside. The inner-layer substrate 1 may include circuit wirings 4 such as via wirings and surface wirings.

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, etc. in consideration of the characteristics of the inner layer substrate. A plurality of cavities may be formed at predetermined intervals, and the opening shape of the cavity is not particularly limited, and may be any shape such as a rectangle, a circle, a substantially rectangle, or a substantially circle.

The temporary attachment material is not particularly limited as long as it has an adhesive surface exhibiting sufficient tackiness for temporarily attaching components, and any conventionally known temporary attachment material may be used in the production of a circuit board with a built-in component. Examples of the temporary sticking material include PFDKE-1525TT (polyimide film with adhesive) manufactured by Arisa and Seisakusho Co., Ltd., and UC series (UV tape for wafer dicing) manufactured by Furukawa Denki Kogyo Co., Ltd. have.

The part is temporarily attached to the adhesive surface of the temporary adhesive 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, and multilayer ceramic capacitors, and active components such as semiconductor bare chips. The same part may be used for all the cavities, and different parts may be used for every 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 lamination conditions of the first main surface and the resin sheet are the same as those of the above-described step (I), and the preferable ranges are also the same.

After laminating the resin composition layer on the first main surface of the inner substrate, the resin composition layer may be thermosetted. The conditions for thermosetting a resin composition layer are the same as the conditions of the above-mentioned process (II), and a preferable 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. You may perform peeling of a temporary attachment material according to a conventionally well-known method according to the kind of temporary attachment material.

Step (iv) is 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. The lamination conditions of the 2nd main surface and the resin sheet are the same as the conditions of the above-mentioned process (I), and the preferable range is also the same. The resin composition layer in a process (iv) may be the same resin composition layer as the resin composition layer in a process (ii), and a different resin composition layer may be sufficient as it. In this invention, it is preferable that the resin sheet in a process (iv) is the resin sheet of this invention.

A process (v) is a process of thermosetting a resin composition layer. The conditions for thermosetting a resin composition layer are the same as the conditions of the above-mentioned process (II), and a preferable range is also the same.

As a manufacturing method of a circuit board with a component, you may further include the process of drilling in an insulating layer (perforating process), the process of roughening the surface of an insulating layer, and the process of forming a conductor layer in the roughened insulating layer surface. These processes are as described above.

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

As a manufacturing method of such a printed wiring board,

(1) a step of preparing a substrate with a wiring layer having an inner-layer substrate and a wiring layer formed on at least one surface of the substrate;

(2) 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;

(3) a step of interconnecting the wiring layers between layers; and

(4) A step of removing the substrate is included.

It is preferable to have a metal layer which consists of copper foil etc. on both surfaces of the inner-layer board|substrate used by this manufacturing method, It is more preferable that the metal layer has the structure in which two or more metal layers are laminated|stacked. For the details of step (1), a dry film (photosensitive resist film) is laminated on an inner layer substrate, exposed and developed under predetermined conditions using a photomask to form a patterned dry film. After forming a wiring layer by the electric field plating method using the developed pattern dry film as a plating mask, the pattern dry film is peeled.

The lamination conditions of the inner layer substrate and the dry film are the same as those of the above-described step (II), and the preferable ranges are also the same.

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

The line (circuit width)/space (width between circuits) 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 15/15 µm or less (pitch 30 µm or less). Although the lower limit in particular of the line/space ratio of a wiring layer is not restrict|limited, Preferably it is 0.5/0.5 micrometer or more, More preferably, it is 1/1 micrometer or more. The pitch need not be the same throughout the wiring layer.

After forming the pattern of the dry film, a wiring layer is formed and the dry film is peeled off. Here, formation of a wiring layer can be performed by the plating method using the dry film in which the desired pattern was formed as a plating mask.

The conductor material used for the wiring layer is not specifically limited. In a suitable embodiment, the wiring layer comprises one or more metals selected from the group consisting of gold, platinum, palladium, silver, copper, aluminum, cobalt, chromium, zinc, nickel, titanium, tungsten, iron, tin and indium. The wiring layer may be a single metal layer or an alloy layer, and the alloy layer is made of, for example, an alloy of two or more metals selected from the group described above (for example, a nickel-chromium alloy, a copper-nickel alloy, and a copper-titanium alloy). formed can be mentioned.

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

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

Process (2) is a process of laminating|stacking the resin sheet of this invention on a base material with a wiring layer so that a wiring layer may be embedded in the resin composition layer, thermosetting it, and forming an insulating layer. Lamination conditions of the base material with a wiring layer and the resin sheet are the same as the conditions of the above-mentioned process (II), and the preferable range is also the same.

The step (3) is not particularly limited as long as the wiring layers can be interconnected between layers, but at least one of the steps of forming a via hole in the insulating layer and forming the conductor layer, and grinding or grinding the insulating layer to expose the wiring layer. It is preferable to be fair. The process of forming a via hole in the insulating layer and forming the conductor layer is the same as described above.

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

Step (4) is a step of removing the inner layer substrate and forming the circuit board of the present invention. The method for removing the inner layer substrate is not particularly limited. In one 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 this invention shows the characteristic excellent in insulation reliability even if the thickness of the insulating layer between a 1st and 2nd conductor layer is 6 micrometers or less. The upper limit of the insulation resistance value after 200 hours has elapsed in an environment of 130°C, 85RH%, and 3.3V application 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 measurement of an insulation resistance value can be measured according to the method as described in <Evaluation of insulation reliability, thickness measurement of the insulating layer between conductor layers> mentioned later.

The printed wiring board manufactured using the resin sheet of this invention shows the characteristic of being excellent in pattern embedding property and component embedding property. Evaluation of pattern embedding property can be measured according to the method as described in <Evaluation of pattern embedding property> mentioned later.

The wiring board manufactured using the resin sheet of this invention shows the characteristic which can suppress the amount of reflow curvature. The upper limit of the amount of reflow deflection at a peak temperature of 260°C is preferably 90 µm, more preferably 80 µm, still more preferably 70 µm. Although it does not specifically limit about a minimum, It can be set as 1 micrometer or more. Evaluation of the amount of reflow deflection can be measured according to the method described in <Evaluation of deflection amount> mentioned 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 equipment include various semiconductor devices provided for electrical products (eg, computers, mobile phones, digital cameras, televisions, etc.) and vehicles (eg, motorcycles, automobiles, trams, ships, aircraft, etc.). .

The semiconductor device of this invention can be manufactured by mounting a component (semiconductor chip) in the conduction|electrical_connection location of a printed wiring board. A "conduction location" is "a location through which an electrical signal is transmitted in a printed wiring board", and the location may be any place, be it a surface or a buried part. In addition, a semiconductor chip will not be specifically limited if it is an electric circuit element which uses a semiconductor as a material.

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, and specifically, the wire bonding mounting method, flip chip mounting method, bumpless buildup layer ( BBUL), the mounting method by an anisotropic conductive film (ACF), the mounting method by a non-conductive film (NCF), etc. are mentioned. Here, the "mounting method using a bumpless build-up layer (BBUL)" is "a mounting method in which a semiconductor chip is directly embedded in a recess of a printed wiring board to connect a semiconductor chip and wiring on a printed wiring board".

Example

Hereinafter, although an Example demonstrates this invention concretely, this 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 of measuring physical properties of inorganic fillers]

First, the measuring method and evaluation method of an inorganic filler are demonstrated.

<Measurement of average particle diameter>

100 mg of inorganic filler, 0.1 g of a dispersing agent (“SN9228” manufactured by Sannobco Co., Ltd.), and 10 g of methyl ethyl ketone were weighed into a vial and dispersed by ultrasonication for 20 minutes. Using a laser diffraction-type particle size distribution analyzer ("SALD-2200" manufactured by Shimadzu Corporation), the particle size distribution was measured by a batch cell method, and the average particle diameter by 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 Muntech Co., Ltd.).

<Measurement of Carbon Amount>

The amount of carbon per unit area of the inorganic filler was measured according to the following procedure. Methyl ethyl ketone (MEK) in a sufficient amount as a solvent was added to the inorganic filler prepared in the preparation example, followed by ultrasonic cleaning at 25°C for 5 minutes. The supernatant was then removed and the solid was dried. The amount of carbon was measured for the obtained solid using a carbon analyzer ("EMIA-320V" manufactured by Horiba Seisakusho Co., Ltd.). Based on the measured value of the amount of carbon and the mass and specific surface area of the inorganic filler used, the amount of carbon per unit area of the inorganic filler was computed.

[Preparation of resin composition]

<Preparation of resin composition 1>

6 parts of cyclohexanedimethanol type epoxy resin (“ZX1658GS” manufactured by Shin-Nittetsu Chemical Co., Ltd., epoxy equivalent approx. 169), bixylenol type epoxy resin (“YX4000HK” manufactured by Mitsubishi Chemical Co., Ltd. “YX4000HK”, epoxy equivalent approx. 185 ) 6 parts, bisphenol AF type epoxy resin (“YL7760” manufactured by Mitsubishi Chemical Co., Ltd., epoxy equivalent about 238) 6 parts, naphthalene-type epoxy resin (“ESN475V” manufactured by Shin-Nittetsu Chemical Co., Ltd. “ESN475V”, epoxy equivalent approx. 330) 15 parts, phenoxy resin (“YX7553BH30” manufactured by Mitsubishi Chemical Co., Ltd., 1:1 solution of cyclohexanone:methylethylketone (MEK) having a solid content of 30% by mass) 10 parts, solvent naphtha 20 parts and cyclo It was made to melt|dissolve in the mixed solvent of 10 parts of hexanone with stirring. 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 a nonvolatile component) 35 parts, an amine-based curing agent 2 parts of curing accelerator (4-dimethylaminopyridine (DMAP), MEK solution having a solid content of 5% by mass), an aminosilane-based coupling agent (“KBM573” manufactured by Shin-Etsu Chemical Co., Ltd.) and phenyltrimethoxysilane (Shin-Etsuka Co., Ltd.) Spherical silica ("UFP-30" manufactured by Denki Chemical Co., Ltd., average particle diameter 0.078 µm, specific surface area 30.7 m2/g, unit After mixing 95 parts of carbon amount per surface area 0.20 mg/m<2>, and disperse|distributing uniformly with a high-speed rotary mixer, it filtered with the cartridge filter ("SHP020" manufactured by ROKITECHNO), and the resin composition 1 was prepared.

<Preparation of resin composition 2>

2 parts of glycidylamine type epoxy resin ("630LSD" manufactured by Mitsubishi Chemical Co., Ltd., epoxy equivalent about 95), bixylenol type epoxy resin ("YX4000HK" manufactured by Mitsubishi Chemical Co., Ltd., epoxy equivalent about 185) 8 Parts, naphthylene ether type epoxy resin (“EXA-7311-G4” manufactured by DIC Corporation, epoxy equivalent about 213) 6 parts, biphenyl type epoxy resin (“NC3000L” manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent about 272) 15 parts and 6 parts of phenoxy resin ("YX7553BH30" manufactured by Mitsubishi Chemical Co., Ltd., 1:1 solution of cyclohexanone:methylethylketone (MEK) having a solid content of 30% by mass) 15 parts of solvent naphtha and It was heat-dissolved in the mixed solvent of 10 parts of cyclohexanone with stirring. After cooling to room temperature, 10 parts of a triazine skeleton-containing cresol novolak curing agent (“LA3018-50P” manufactured by DIC Co., Ltd., 2-methoxypropanol solution with a hydroxyl equivalent of about 151 and a solid content of 50%), active 15 parts of an 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 a nonvolatile component), an amine curing accelerator (4-dimethylaminopyridine (DMAP)) , MEK solution having a solid content of 5% by mass) 1 part, rubber particles (“EXL2655” manufactured by Dow Chemical Corporation) 2 parts, an aminosilane-based coupling agent (“KBM573” manufactured by Shin-Etsu Chemical Co., Ltd.) 60 parts of treated spherical silica (“SPH516-05” manufactured by Shin-Nittetsu Sumikin Materials Co., Ltd., average particle diameter 0.29 µm, specific surface area 16.3 m 2 /g, carbon content per unit area 0.43 mg/m 2 ), aminosilane-based Spherical silica (Denki Chemical Co., Ltd.) surface-treated with a coupling agent (“KBM573” manufactured by Shin-Etsu Chemical Co., Ltd.) and phenyltrimethoxysilane (“KBM103” manufactured by Shin-Etsu Chemical Co., Ltd.) in a weight ratio of 1:1 After mixing 40 parts of "UFP-30" manufactured by Co., Ltd., an average particle diameter of 0.078 µm, a specific surface area of 30.7 m 2 /g, a carbon amount of 0.20 mg/m 2 per unit area), and uniformly dispersing with a high-speed rotary mixer, a cartridge filter ("SHP020" manufactured by ROKITECHNO) filtered to prepare a resin composition 2.

<Preparation of resin composition 3>

4 parts of naphthalene type epoxy resin (“HP4032SS” manufactured by DIC Corporation, epoxy equivalent about 144), 12 parts of naphthalene ether type epoxy resin (“EXA-7311-G4” manufactured by DIC Corporation, about 213 epoxy equivalent), naphthalene 15 parts of type epoxy resin ("ESN475V" manufactured by Shin-Nittetsu Chemical Co., Ltd., epoxy equivalent about 330), and phenoxy resin ("YX7553BH30" manufactured by Mitsubishi Chemical Co., Ltd., cyclohexanone having a solid content of 30% by mass: A 1:1 solution of methyl ethyl ketone (MEK)) 5 parts was dissolved by heating in a mixed solvent of 15 parts of solvent naphtha and 10 parts of cyclohexanone while stirring. After cooling to room temperature, 30 parts of a prepolymer of bisphenol A dicyanate ("BA230S75" manufactured by Ronjapan Co., Ltd., a cyanate equivalent of about 232, a MEK solution having a nonvolatile content of 75% by mass) 30 parts, an active ester-based curing agent (DIC Co., Ltd. "HPC-8000-65T", active group equivalent about 225, toluene solution of 65 mass % of nonvolatile components) 8 parts, amine-type hardening accelerator (4-dimethylaminopyridine (DMAP), solid content 5 mass %) of MEK solution) 0.4 parts, curing accelerator (manufactured by Tokyo Kasei Co., Ltd., cobalt(III) acetylacetonate (CO(III)Ac), MEK solution having a solid content of 1% by mass) 3 parts, flame retardant (manufactured by Sanko Co., Ltd.) "HCA-HQ", 10-(2,5-dihydroxyphenyl)-10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide, average particle diameter 1.1 µm) 2 parts, aminosilane-based Spherical silica surface-treated with a coupling agent (“KBM573” manufactured by Shin-Etsu Chemical Co., Ltd.) (“SPH516-05” manufactured by Shin-Nitetsu Sumikin Materials Co., Ltd., average particle diameter 0.29 μm, specific surface area 16.3 m 2 /g , carbon content per unit surface area 0.43 mg/m2) 80 parts, epoxy silane coupling agent (“KBM403” manufactured by Shin-Etsu Chemical Co., Ltd.) and phenyltrimethoxysilane (“KBM103” manufactured by Shin-Etsu Chemical Co., Ltd.) ') surface-treated at a weight ratio of 1:1 ("UFP-40" manufactured by Denki Chemical Co., Ltd., average particle diameter 0.067 µm, specific surface area 40.8 m 2 /g, carbon content per unit surface area 0.19 mg/ m 2 ) 30 parts were mixed and uniformly dispersed with a high-speed rotary mixer, followed by filtration with a cartridge filter ("SHP020" manufactured by ROKITECHNO) to prepare a resin composition 3.

<Preparation of resin composition 4>

6 parts of bisphenol-type epoxy resin (“ZX1059” manufactured by Shin-Nittetsu Chemical Co., Ltd., epoxy equivalent of about 169, 1:1 mixture of bisphenol A and bisphenol F) 6 parts, bixylenol-type epoxy resin (Mitsubishi Chemical) Co., Ltd. "YX4000HK", epoxy equivalent about 185) 6 parts, bisphenol AF type epoxy resin ("YL7760" manufactured by Mitsubishi Chemical Co., Ltd., epoxy equivalent about 238) 6 parts, naphthalene type epoxy resin (New Nittetsu Chemicals) Co., Ltd. "ESN475V", epoxy equivalent about 330) 15 parts, phenoxy resin (Mitsubishi Chemical Co., Ltd. "YX7553BH30", solid content 30% by mass cyclohexanone: methyl ethyl ketone (MEK) 1:1 10 parts of solution) was heat-dissolved, stirring, in the mixed solvent of 25 parts of solvent naphtha, and 10 parts of cyclohexanone. 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 a nonvolatile component) 35 parts, an amine-based curing agent 2 parts of curing accelerator (4-dimethylaminopyridine (DMAP), MEK solution having a solid content of 5% by mass), an epoxysilane-based coupling agent (“KBM403” manufactured by Shin-Etsu Chemical Co., Ltd.) and phenyltrimethoxysilane (Shin-Etsuka) Spherical silica (“UFP-40” manufactured by Denki Chemical Co., Ltd., average particle diameter 0.067 μm, specific surface area 40.8 m 2 /g, unit After mixing 95 parts of carbon content per surface area of 0.19 mg/m 2 ) and uniformly dispersing with a high-speed rotary mixer, it was filtered with a cartridge filter ("SHP020" manufactured by ROKITECHNO) to prepare a resin composition 4.

<Preparation of resin composition 5>

Preparation of resin composition 3 WHEREIN: 1) The addition amount of solvent naphtha was changed from 15 parts to 8 parts, 2) 2 types of inorganic fillers (two types of spherical silica) were used as an epoxysilane coupling agent (Shin-Etsu Chemical Co., Ltd.) Spherical silica (manufactured by "KBM403") surface-treated ("Adomafine SO-C1" manufactured by Adomatex Co., Ltd., average particle diameter 0.63 µm, specific surface area 11.2 m 2 /g, carbon content per unit surface area 0.28 mg/ m2) was changed to 110 parts, and 3) a cartridge filter (“SHP020” manufactured by ROKITECHNO) was replaced with a cartridge filter (“SHP030” manufactured by ROKITECHNO), except that the resin composition 5 was prepared in the same manner as in the preparation of the resin composition 3.

<Preparation of resin composition 6>

2 parts of glycidylamine type epoxy resin ("630LSD" manufactured by Mitsubishi Chemical Co., Ltd., epoxy equivalent about 95), bixylenol type epoxy resin ("YX4000HK" manufactured by Mitsubishi Chemical Co., Ltd., epoxy equivalent about 185) 8 Parts, naphthylene ether type epoxy resin (“EXA-7311-G4” manufactured by DIC Corporation, epoxy equivalent about 213) 6 parts, biphenyl type epoxy resin (“NC3000L” manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent about 272) 15 parts and 10 parts of phenoxy resin (“YX7553BH30” manufactured by Mitsubishi Chemical Co., Ltd., 1:1 solution of cyclohexanone:methylethyl ketone (MEK) having a solid content of 30% by mass) 10 parts of solvent naphtha and It was heat-dissolved in the mixed solvent of 5 parts of cyclohexanone with stirring. After cooling to room temperature, 10 parts of a triazine skeleton-containing cresol novolac curing agent (“LA3018-50P” manufactured by DIC Corporation, a hydroxyl equivalent of about 151, a solution of 50% in solid content in 2-methoxypropanol); 15 parts of active ester curing agent (“EXB-8000L-65TM” manufactured by DIC Corporation, about 220 active group equivalents, 65% by mass of nonvolatile components in toluene/MEK solution), amine curing accelerator (4-dimethylaminopyridine (DMAP) ), a MEK solution having a solid content of 5% by mass) 1 part, rubber particles (“EXL2655” manufactured by Dow Chemical Corporation) 2 parts, an epoxy silane coupling agent (“KBM403” manufactured by Shin-Etsu Chemical Co., Ltd.) and Spherical silica surface-treated with phenyltrimethoxysilane (“KBM103” manufactured by Shin-Etsu Chemical Co., Ltd.) at a weight ratio of 1:1 (“UFP-40” manufactured by Denki Chemical Co., Ltd., average particle diameter of 0.067 μm, 35 parts of specific surface area 40.8 m / g, carbon amount per unit surface area of 0.19 mg / m) are mixed and uniformly dispersed with a high-speed rotary mixer, followed by filtration with a cartridge filter ("SHP020" manufactured by ROKITECHNO) to prepare a resin composition 6 did.

The components used for preparation of the resin compositions 1-6 and the compounding quantity (mass part of a non-volatile matter) are shown in Table 1.

[Production of resin sheet]

As a support, a PET film (“Lumiror R80” manufactured by Toray Co., Ltd., 38 μm thick, softening point 130° C., “Release PET”) was prepared with an alkyd resin mold release agent (“AL-5” manufactured by Lintec Co., Ltd.) did.

The resin composition layer was obtained on the mold release PET by drying each resin composition on the mold release PET from 70 ° C. to 95 ° C. for 2 minutes, uniformly applied with a die coater so that the thickness of the resin composition layer after drying was 13 µm. Next, the rough surface of a polypropylene film ("Alpen MA-411" manufactured by Ogiftex Co., Ltd., 15 µm thick) as a protective film on the surface not bonded to the support body of the resin sheet is bonded to the resin composition layer stacked so as to Thereby, the resin sheet which consists of mold release PET (support body), a resin composition layer, and a protective film in order was obtained.

[Evaluation Test]

<Measurement of Minimum Melt Viscosity>

Only the resin composition layer was peeled from the resin sheet, and the pellet for a measurement (diameter 18mm, 1.2-1.3g) was produced by compressing with a metal mold|die.

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

<Measurement of average coefficient of linear thermal expansion (CTE) of cured product>

The untreated side of the release PET film (“501010” manufactured by Lintec Co., Ltd., 38 μm thick, 240 mm square) is a glass cloth-based epoxy resin double-sided copper clad laminate (“R5715ES” manufactured by Matsushita Denko Co., Ltd., 0.7 mm thick) , 255 mm each) was installed 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 of the resin sheets produced in Examples and Comparative Examples was subjected to a batch type vacuum pressurization laminator (Nikko Materials Co., Ltd. 2-stage build-up laminator, CVP700), and the resin composition layer was ) was laminated in the center so as to be in contact with the release surface of manufacture "501010"). After the lamination process was pressure-reduced for 30 second and the atmospheric pressure was 13 hPa or less, it was performed by crimping|bonding at 100 degreeC and pressure 0.74 MPa for 30 second.

Then, under the temperature condition of 100 ℃, after being put in the oven at 100 ℃ 30 minutes, then transferred to the oven at 180 ℃ under the temperature condition of 180 ℃ was thermally cured for 30 minutes. Then, the board|substrate was taken out in room temperature atmosphere, after peeling the mold release PET (support body) from the resin sheet, it was made to thermoset under hardening conditions for 90 minutes after throwing-in in 200 degreeC oven further.

After thermosetting, the polyimide adhesive tape was peeled off, and the hardened|cured material was isolate|separated from the glass cloth base epoxy resin double-sided copper clad laminated board. Further, the release PET film ("501010" manufactured by Lintec Co., Ltd.) on which the resin composition layer had been laminated was peeled off to obtain a sheet-shaped cured product. The obtained hardened|cured material is called "hardened|cured material for evaluation".

The cured product for evaluation was cut into test pieces having a width of 5 mm and a length of 15 mm, and thermomechanical analysis was performed by a tensile weighting method using a thermomechanical analyzer (“Thermo Plus TMA8310” manufactured by Rigaku Corporation). In detail, after mounting the test piece to the said thermomechanical analysis apparatus, it measured twice successively under the measurement conditions of 1 g of load and 5 degreeC/min of temperature increase rate. And the average coefficient of linear thermal expansion (ppm/degreeC) in the plane direction in the range from 25 degreeC to 150 degreeC by two measurements was computed, and is shown in Table 2.

<Evaluation of pattern embedding and flatness>

(Preparation of substrate for evaluation)

(1) Underlay treatment of inner-layer circuit board

As an inner-layer circuit board, a glass cloth-based epoxy resin double-sided copper-clad laminate (a copper foil thickness of 18 µm, a substrate having a circuit conductor (copper) formed in a 1 mm square grid wiring pattern (residual rate of 59%) on both sides) on both sides. Thickness 0.15mm, Mitsubishi Chemical Co., Ltd. product "HL832NSF LCA, 255*340mm size) was prepared. The copper surface roughening process (copper etching amount 0.5 micrometer) was performed for both surfaces of the said inner-layer circuit board by Meg Co., Ltd. product "CZ8201".

(2) Lamination of resin sheets

Each resin sheet produced in Examples and Comparative Examples was subjected to a batch type vacuum pressurization laminator (manufactured by Nikko Materials Co., Ltd., two-stage build-up laminator, CVP700) to form an inner layer such that the resin composition layer was in contact with the inner circuit board. Laminated on both sides of the circuit board. The lamination was pressure-reduced for 30 seconds, the atmospheric pressure was 13 hPa or less, and it was performed by crimping|bonding for 45 second at 130 degreeC and a pressure of 0.74 MPa. Then, it hot-pressed for 75 second at 120 degreeC and the pressure of 0.5 MPa.

(3) Thermosetting of the resin composition layer

The inner circuit board on which the resin sheet was laminated was put into an oven at 100° C. under a temperature condition of 100° C. for 30 minutes, then transferred to an oven at 180° C. under a temperature condition of 180° C., and thermosetted for 30 minutes to form an insulating layer. Let this be "substrate A for evaluation".

(Evaluation of pattern embedding properties)

The support made of the substrate A for evaluation was peeled off, the surface of the insulating layer was observed with a micro-optical microscope, and it was evaluated as "○" when it was firmly buried without voids, and when voids were generated due to insufficient embedding It was evaluated by "x" and shown in Table 2. Further, with respect to Comparative Example 1, since the minimum melt viscosity in both strain 1deg and strain 5deg was too high and pattern embedding was not possible, the following evaluation tests (evaluation of flatness, evaluation of insulation reliability, insulation layer between conductor layers) thickness measurement and evaluation of warpage) could not be performed.

(Evaluation of flatness)

The support body was peeled from the board|substrate A for evaluation, and the flatness of the insulating layer in the area|region on a grid|lattice pattern was measured with the non-contact type surface roughness meter ("WYKO NT3300" manufactured by BCoin Instruments). The maximum cross-sectional height Rt was measured in the area|region of 4 places of 10 times magnification and 0.82 mm x 1.1 mm, and the average value was computed. The case where the average value of Rt was 1.5 µm or less was evaluated as "○", and the case where the average value of Rt exceeded 1.5 µm was evaluated as "x", and it is shown in Table 2.

<Evaluation of insulation reliability, measurement of thickness of insulating layer between conductor layers>

(4) Formation of via holes

From the top of the insulating layer and support of the substrate A for evaluation prepared in (3), Mitsubishi Denki Co., Ltd. CO ₂ laser processing machine "605GTWIII(-P)" was used to irradiate the laser from the top of the support to form a grid pattern. A via hole having a top diameter (70 µm) was formed in the insulating layer on the conductor. 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 number of shots of 2, and a burst mode (10 kHz).

(5) The process of performing a roughening process

The support body was peeled from the circuit board in which the via hole was formed, and the desmear process was performed. In addition, as a desmear process, the following wet desmear process was implemented.

Wet desmear treatment:

In a swelling solution (“Swelling Deep Securigant P” manufactured by Atotech Japan Co., Ltd., an aqueous solution of diethylene glycol monobutyl ether and sodium hydroxide) at 60° C. for 5 minutes, then an oxidizing agent solution (“Atotech Japan Co., Ltd.” Concentrate Compact CP”, an aqueous solution with a potassium permanganate concentration of about 6% and sodium hydroxide concentration of about 4%) at 80°C for 10 minutes, and finally a neutralization solution (“Reduction Solution Securigant P” manufactured by Atotech Japan Co., Ltd.) , sulfuric acid aqueous solution) at 40° C. for 5 minutes, followed by drying at 80° C. for 15 minutes.

(6) Step of forming the conductor layer

(6-1) Electroless plating process

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

1. Alkaline cleaning (cleaning the surface of the insulating layer with via holes and adjusting the charge)

Product name: Using Cleaning Cleaner Securiganth 902 (trade name), it was washed at 60° C. for 5 minutes.

2. Soft etching (cleaning in the via hole)

It was treated at 30° C. for 1 minute using a sulfuric acid acid sodium peroxodisulfate aqueous solution.

3. Predip (adjustment of surface charge of insulating layer to impart Pd)

Pre. Dip Neoganth B (trade name) was used for 1 minute treatment at room temperature.

4. Activator application (application of Pd to the surface of the insulating layer)

Activator Neoganth 834 (trade name) was used for treatment at 35° C. for 5 minutes.

5. Reduction (reduction of Pd imparted to the insulating layer)

A mixed solution of Reducer Neoganth WA (trade name) and Reducer Acceralator 810mod. (trade name) was used and treated at 30° C. for 5 minutes.

6. Electroless copper plating process (Cu is deposited on the surface of the insulating layer (Pd surface))

Basic Solution Printganth MSK-DK (trade name), Copper solution Printganth MSK (trade name), Stabilizer Printganth MSK-DK (trade name), and Reducer Cu (trade name) were treated at 35° C. for 20 minutes using a mixture. The thickness of the formed electroless copper plating layer was 0.8 mu m.

(6-2) Electrolytic plating process

Next, the electrolytic copper plating process was performed using the chemical|medical solution manufactured by Atotech Japan Co., Ltd. under the condition that copper is filled in the via hole. Thereafter, as a resist pattern for patterning by etching, a land pattern with a diameter of 1 mm conducted through the via hole and a circular conductor pattern with a diameter of 10 mm which is not connected to the lower layer conductor were used on the surface of the insulating layer by 10 µm. A conductor layer having a land and a conductor pattern was formed to a thickness of . Subsequently, annealing treatment was performed at 200°C for 90 minutes. This board|substrate was made into the board|substrate B for evaluation.

(Measurement of thickness of insulating layer between conductor layers)

Cross-sectional observation was performed for the board|substrate B for evaluation using the FIB-SEM composite apparatus ("SMI3050SE" manufactured by SII Nanotechnology Co., Ltd.). In detail, the cross section in the direction perpendicular to the surface of the conductor layer was cut by FIB (focused ion beam), and the thickness of the insulating layer between the conductor layers was measured from the cross-sectional SEM image. For each sample, cross-sectional SEM images of five randomly selected locations were observed, and the average value was shown in Table 2 as the thickness (µm) of the insulating layer between the conductor layers.

(Evaluation of insulation reliability of insulating layer)

A highly accelerated life test was performed using the circular conductor side of the substrate A obtained above with a diameter of 10 mm as the + electrode, and the grid conductor (copper) side of the inner-layer circuit board connected to the land with a diameter of 1 mm as the - electrode. Using an apparatus (“PM422” manufactured by ETAC), the insulation resistance value when 200 hours have elapsed under the conditions of 130°C, 85% relative humidity, and 3.3V DC voltage application was measured using an electrochemical migration tester (manufactured by J-RAS Co., Ltd.). "ECM-100") (n=6). In all six test pieces, the case where the resistance value was 10 ⁷ Ω or more was “○”, and when even one ^{was less than 10 7} Ω, it was “x”, and the evaluation results and insulation resistance values were shown in Table 2. The insulation resistance value described in Table 2 is the lowest value of the insulation resistance value of the test piece of 6 points|pieces.

<Evaluation of warpage amount>

(Preparation of substrate C for evaluation)

After peeling a support body from the board|substrate A for evaluation, thermosetting for 90 minutes was implemented at 200 degreeC. The obtained board|substrate was made into the board|substrate C for evaluation.

(evaluation test of reflow deflection amount)

After the evaluation substrate C was cut into pieces of 45 mm square (n = 5), a reflow device that reproduces the solder reflow temperature with a peak temperature of 260°C (“HAS-6116” manufactured by Nippon Antom Co., Ltd.) (reflow temperature profile conforms to IPC/JEDEC J-STD-020C). Next, using a shadow moire apparatus ("TherMoire AXP" manufactured by Akrometrix), the lower surface of the substrate is heated with a reflow temperature profile conforming to IPC/JEDEC J-STD-020C (peak temperature 260°C), and 10 mm at the center of the substrate The displacement amount (㎛) of each part was measured, and the measurement results are shown in Table 2.

100 Temporary Attachment Inner Layer Board (Cavity Board)
1 inner layer substrate
1a cavity
11 1st week
12 2nd week
2 Temporary material
3 parts
4 circuit wiring
5 first conductor layer
51 Main surface of the first conductor layer
6 second conductor layer
61 Main surface of the second conductor layer
7 Insulation layer

Claims (8)

A resin sheet comprising a resin composition layer comprising (A) an epoxy resin, (B) a curing agent, and (C) an inorganic filler,
When the nonvolatile component in the said resin composition layer is 100 mass %, (C) inorganic filler is 50 mass % or more,
The minimum melt viscosity of the resin composition layer at a frequency of 1 Hz and a deformation of 1deg is 8000 poise or more,
The minimum melt viscosity of the resin composition layer at a frequency of 1 Hz and a strain of 5 deg is 8000 poise or less,
The thickness of the resin composition layer is 15 μm or less,
The average particle diameter of the said (C) inorganic filler is 0.05-0.35 micrometer,
resin sheet. The resin sheet according to claim 1, wherein (A) the epoxy resin contains a liquid epoxy resin. The resin sheet according to claim 1, which is for forming an insulating layer of a printed wiring board. The first conductor layer, the second conductor layer, and an insulating layer that insulates the first conductor layer and the second conductor layer according to any one of claims 1 to 3, comprising: the first conductor layer; The resin sheet for forming the said insulating layer of the printed wiring board whose thickness of the insulating layer between 2nd conductor layers is 6 micrometers or less. A first conductor layer, a second conductor layer, and an insulating layer that insulates the first conductor layer and the second conductor layer, wherein the insulating layer between the first conductor layer and the second conductor layer has a thickness of 6 µm As the following printed wiring board,
The said insulating layer is a hardened|cured material of the resin composition layer of the resin sheet in any one of Claims 1-3, The printed wiring board. A semiconductor device comprising the printed wiring board according to claim 5 . delete delete

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