KR20150016105A - Method for manufacturing multilayer printed wiring board - Google Patents

Abstract

Provided is a method for manufacturing a multi-layer printed wiring board, which can realize an insulating layer with excellent surface smoothness and excellent layer thickness uniformity due to a small thickness difference between the center portion and the end portion of a substrate even when forming the insulating layer using prepreg with a high total content of a fiber base and an inorganic filler. The method for manufacturing a multi-layer printed wiring board comprises the steps of: (I) laminating carrier mounting prepreg, in which prepreg is formed on a carrier film, on an internal layer circuit board to bond the prepreg to the internal layer circuit board; (II) thermally pressing the laminated carrier mounting prepreg to smooth the carrier mounting prepreg; and (III) thermally curing the prepreg to form an insulating layer. When the total weight of the prepreg is 100 wt%, the total weight of a fiber base and an inorganic filler in the prepreg is 70 wt% or greater. The melt viscosity of the prepreg at a thermal pressing temperature of the step (II) is 300 to 10000 poise. The maximum sectional height (Rt) of the surface of the carrier film of the carrier mounting prepreg after the step (I) is smaller than 5 μm. Also, when the lamination temperature of the step (I) is T1(°C) and the thermal pressing temperature of the step (II) is T2(°C), T1 and T2 satisfies the relation: T2 <= T1 + 10.

Description

METHOD FOR MANUFACTURING MULTILAYER PRINTED WIRING BOARD BACKGROUND OF THE INVENTION 1. Field of the Invention [0001]

The present invention relates to a method of manufacturing a multilayer printed wiring board. More particularly, the present invention relates to a method of manufacturing a multilayer printed circuit board using a carrier mounting prepreg.

As a manufacturing technique of a multilayered printed circuit board, a manufacturing method by a build-up method in which an insulating layer and a conductor layer are alternately laminated is known. In the build-up method, generally, the insulating layer is formed by thermally curing the resin composition. For example, a method of forming an insulating layer with a vacuum laminator by using an adhesive film having a resin composition layer formed on a carrier film is used. Recently, a method of forming an insulating layer by a vacuum laminator using a carrier mounting prepreg has been proposed in order to increase the mechanical strength of the insulating layer in accordance with the demand for thinning of the multilayer printed wiring board (Patent Document 1).

International Publication No. 2009/35014

On the other hand, in accordance with the thinning of the multilayered printed circuit board, in order to prevent cracks or the like due to the difference in thermal expansion from the conductor layer, the lowering of the thermal expansion coefficient of the insulating layer becomes more and more important. As means for lowering the thermal expansion coefficient of the insulating layer, for example, there can be mentioned a method of increasing the content of the fibrous base material and / or the inorganic filler in the prepreg used for forming the insulating layer. However, when a prepreg having a high content of a fibrous substrate and / or an inorganic filler is used, it tends to be difficult to form an insulating layer having a smooth surface. For example, in the technique described in Patent Document 1, a step of laminating a carrier mounting prepreg using a vacuum laminator to an inner layer circuit board, followed by a step of flattening the surface of the laminated carrier mounting prepreg with a metal plate by hot pressing However, in the case of using a prepreg having a high content of a fibrous substrate and / or an inorganic filler, it is difficult for the prepreg to follow the surface unevenness (due to the presence or absence of a circuit conductor) of the inner-layer circuit board, It is likely to have undulations corresponding to the surface irregularities of the inner layer circuit board which is the base, and it tends to be difficult to obtain an insulating layer whose surface is smooth.

For example, in the case of hot pressing under conditions that the fluidity of the resin is high, such as setting the hot press temperature in the smoothing step, the followability of the prepreg to the surface unevenness of the inner layer circuit board is improved, The relief can be made small. In this case, however, the inventors have found that the balance of the layer thickness of the insulating layer is collapsed due to leakage of the resin or the like, and a large difference is generated in the thickness of the obtained insulating layer at the center portion of the substrate and the end portion of the substrate.

Even when an insulating layer is formed by using a prepreg having a high total content of a fibrous base material and an inorganic filler, the present invention is excellent in the smoothness of the surface and has a small thickness difference between the center portion of the substrate and the end portion of the substrate, An object of the present invention is to provide a method of manufacturing a multilayered printed circuit board capable of realizing an insulating layer.

The inventors of the present invention have conducted extensive studies in view of the above problems and found that a prepreg having a specific content of a fiber base material and an inorganic filler of a certain amount or more and having a specific melt viscosity is used to form an insulating layer using a carrier- The maximum cross-section height (Rt) of the carrier film surface of the carrier mounting prepreg after the lamination process is maintained at a predetermined value or less and the difference between the laminate temperature in the lamination process and the heat press temperature in the smoothing process is set within a specified range The above problems can be solved, and the present invention has been accomplished.

That is, the present invention includes the following contents.

[1] A method for manufacturing a semiconductor device, comprising the steps of: (I) laminating a carrier mounting prepreg on which a prepreg is formed on a carrier film so that a prepreg is bonded to an inner-

(II) a step of hot pressing and smoothing the laminated carrier mounting prepreg, and

(III) a step of thermally curing the prepreg to form an insulating layer, the method comprising:

When the total mass of the prepreg is 100 mass%, the total mass of the fibrous base material and the inorganic filler in the prepreg is 70 mass% or more,

The melt viscosity of the prepreg at the hot press temperature in the step (II) is 300 to 10000 poise,

The maximum cross-sectional height (Rt) of the carrier film surface of the carrier mounting prepreg after step (I) is less than 5 占 퐉,

Wherein T1 and T2 satisfy a relationship of T2 &lt; = T1 + 10, where T1 (° C) is the lamination temperature of the process (I) and T2 (° C) is the heat press temperature of the process (II) A manufacturing method of a printed wiring board.

[2] The method according to [1], wherein T1 and T2 satisfy a relationship of T2? T1 + 5.

[3] The method according to [1] or [2], wherein the step (II) is carried out two or more times.

[4] The method according to any one of [1] to [3], wherein the maximum cross-sectional height Rt of the surface of the insulating layer after the step (III) is less than 3 μm.

[5] The method according to any one of [1] to [4], wherein the prepreg further contains an epoxy resin and a curing agent.

[6] The method according to any one of [1] to [5], wherein the prepreg is formed by impregnating a fiber substrate with a resin composition containing an epoxy resin, a curing agent and an inorganic filler.

[7] The method according to any one of [1] to [6], wherein the carrier film is peeled off after the step (III).

[8] The method according to any one of [1] to [7], wherein in the step (III), the prepreg is vertically arranged in a heating oven and thermally cured to form an insulating layer.

[9] A multilayer printed wiring board comprising an insulating layer satisfying the following conditions (a) to (c):

(a) when the total mass of the insulating layer is 100 mass%, the total mass of the fibrous base material and the inorganic filler is 70 mass% or more;

(b) the maximum cross-sectional height (Rt) of the surface of the insulating layer is less than 3 mu m; And

(c) the difference between the thickness of the substrate end portion of the insulating layer and the thickness of the central portion of the substrate is less than 2.5 mu m.

According to the method of the present invention, even when the insulating layer is formed using a prepreg having a high total content of the fibrous base material and the inorganic filler, the surface smoothness is excellent and the difference in thickness between the central portion of the substrate and the end portion of the substrate is small, It is possible to produce a multilayer printed wiring board having a well-balanced insulating layer.

Before describing in detail the method of manufacturing the multilayered printed circuit board of the present invention, the &quot; carrier mounting prepreg &quot; used in the method of the present invention will be described.

<Carrier mounting prepreg>

In the method of the present invention, a carrier mounting prepreg on which a prepreg is formed on a carrier film is used.

As the carrier film, a film made of a plastic material, a metal foil (copper foil, aluminum foil, etc.), and a release paper can be given, and a film made of a plastic material is suitably used. Examples of the plastic material include polyesters such as polyethylene terephthalate (hereinafter may be abbreviated as "PET") and polyethylene naphthalate (hereinafter sometimes abbreviated as "PEN"), polycarbonate (TAC), polyether sulfide (PES), polyether ketone, polyimide, and the like, such as polymethyl methacrylate (PMMA) . Of these, polyethylene terephthalate and polyethylene naphthalate are preferable, and inexpensive polyethylene terephthalate is particularly preferable. In a preferred embodiment, the carrier film is a polyethylene terephthalate film.

The carrier film may be subjected to a mat treatment or a corona treatment on the surface to be bonded with the prepreg.

As the carrier film, a carrier film with a release layer having a release layer on the surface to be bonded to the prepreg may be used. As the releasing agent to be used for the release layer of the carrier film with release layer, there may be mentioned, for example, one or more release agents selected from the group consisting of an alkyd resin, a polyolefin resin, a urethane resin, and a silicone resin.

In the present invention, commercially available products may be used as the carrier film with a release layer. Examples of commercially available products include "PET501010", "SK-1", "AL-5", and "AL-7" manufactured by Lintec Corporation.

The thickness of the carrier film is not particularly limited, but is preferably in the range of 10 to 70 mu m, more preferably in the range of 20 to 60 mu m, and further preferably in the range of 20 to 50 mu m. When the carrier film is a carrier film with a release layer, it is preferable that the thickness of the entire carrier film with release layer is in the above range.

A prepreg is formed by impregnating a fiber substrate with a resin composition.

The fiber substrate is not particularly limited, and those commonly used as prepreg substrates such as glass cloth, aramid nonwoven fabric, and liquid crystal polymer nonwoven fabric can be used. When used in the formation of the insulating layer of the multilayer printed wiring board, a thin sheet-like fibrous substrate having a thickness of 50 탆 or less is suitably used, and particularly a sheet-like fibrous substrate having a thickness of 10 to 40 탆 is preferable, Is more preferable.

Specific examples of the glass cloth which can be used as the sheet-like fiber base material include "Style 1027MS" (slope density 75/25 mm, weft density 75/25 mm, cloth weight 20 g / (Warp density of 70/25 mm, weft density of 73/25 mm, cloth weight of 24 g / m 2, thickness of 28 탆) manufactured by Asahi Shoe Bell Co., 1037NS &quot; (trade name, manufactured by Asahi Chemical Industry Co., Ltd.) manufactured by WASEKAKUSHO Co., Ltd. (warp density 54/25 mm, weft density 54/25 mm, cloth weight 48 g / Quot; 1027NS &quot; (warp density of 75/25 mm, weft density of 69/25 mm, cloth weight of 23 g / m 2, thickness of 21 탆) 1015NS &quot; (a warp density of 95 yarns / 25 mm, a weft density of 95 yarns / 25 mm, a thickness of 16 mm), manufactured by Arisawa Seisakusho Co., 1000 g / m &lt; 2 &gt;), manufactured by Arisawa Seisakusho Co., Ltd. A warp density of 85/25 mm, a weft density of 85/25 mm, a cloth weight of 11 g / m 2, a thickness of 10 탆). Specific examples of the liquid crystal polymer nonwoven fabric include "Becklose" (basis weight 6 to 15 g / m 2) and "Becktran" by the melt blowing method of an aromatic polyester nonwoven fabric manufactured by Kuraray Co., Ltd.

The resin composition for use in the prepreg is not particularly limited as long as the cured product has sufficient hardness and insulating properties, and conventionally known resin compositions used for forming the insulating layer of the multilayer printed wiring board may be used.

From the viewpoint of suppressing the thermal expansion coefficient of the resulting insulating layer to a low level, it is preferable that the resin composition used for the prepreg contains an inorganic filler.

Examples of the inorganic filler include inorganic fillers such as silica, silicon nitride, alumina, glass, cordierite, silicon oxide, barium sulfate, barium carbonate, talc, clay, mica powder, zinc oxide, hydrotalcite, Wherein the metal oxide is at least one selected from the group consisting of magnesium, calcium carbonate, magnesium carbonate, magnesium oxide, boron nitride, aluminum nitride, manganese nitride, aluminum borate, barium titanate, strontium carbonate, strontium titanate, calcium titanate, magnesium titanate, bismuth titanate, titanium oxide, zirconium titanate Barium, barium zirconate, calcium zirconate, zirconium phosphate, and zirconium tungstate phosphate. Of these, silica such as amorphous silica, fused silica, crystalline silica, synthetic silica, hollow silica and the like is particularly suitable. As the silica, spherical silica is preferable. The inorganic fillers may be used singly or in combination of two or more kinds. As commercially available spherical fused silica, "SOC4", "SOC2", and "SOC1" manufactured by Adomex Co., Ltd. can be mentioned.

The average particle diameter of the inorganic filler is preferably 2 mu m or less, more preferably 1 mu m or less, still more preferably 0.8 mu m or less, still more preferably 0.8 mu m or less, Or less. On the other hand, from the viewpoint of improving the dispersibility of the inorganic filler, the average particle diameter of the inorganic filler is preferably not less than 0.01 mu m, more preferably not less than 0.05 mu m, further preferably not less than 0.1 mu m. The average particle diameter of the inorganic filler can be measured by a laser diffraction / scattering method based on the Mie scattering theory. Specifically, the particle size distribution of the inorganic filler can be measured with a laser diffraction scattering type particle size distribution measuring apparatus, and the median diameter is determined as the average particle diameter. The sample to be measured may preferably be an inorganic filler dispersed in water by ultrasonic waves. As the laser diffraction scattering type particle size distribution measuring apparatus, LA-950 manufactured by Horiba Seisakusho Co., Ltd. and the like can be used.

The content of the inorganic filler in the resin composition is preferably not less than 40% by mass, more preferably not less than 50% by mass, and further preferably not less than 60% by mass from the viewpoint of suppressing the thermal expansion coefficient of the obtained insulating layer to a low level. The upper limit of the content of the inorganic filler in the resin composition is not particularly limited, but is preferably 90% by mass or less, more preferably 85% by mass or less from the viewpoint of obtaining an insulating layer having a good surface smoothness.

On the other hand, in the present invention, the content of each component in the resin composition is a value when the nonvolatile component in the resin composition is taken as 100% by mass.

In order to improve the moisture resistance, the inorganic filler is preferably subjected to surface treatment of at least one of an epoxy silane coupling agent, an aminosilane coupling agent, a mercaptosilane coupling agent, a silane coupling agent, an organosilazane compound and a titanate coupling agent It is preferable that it is treated with zero. Among the surface treatment agents, the aminosilane-based coupling agent is preferable because it is excellent in moisture resistance, dispersibility, and properties of a cured product. The inorganic filler may be pretreated with a surface treating agent before mixing with the resin composition. Alternatively, the inorganic filler may be treated with a surface treatment agent by adding an inorganic filler and a surface treatment agent to the resin composition (that is, by the integral blend method). As commercially available products of surface treatment agents, KBM403 (3-glycidoxypropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., KBM803 (3-mercaptopropyltrimethoxysilane manufactured by Shin-Etsu Chemical Co., KBE903 "(3-aminopropyltriethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd.," KBM573 "(N-phenyl-3-aminopropyltrimethoxysilane) manufactured by Shin- , KBM103 (phenyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., and SZ-31 (hexamethyldisilazane) manufactured by Shin-Etsu Chemical Co.,

The throughput of the surface treatment agent is preferably 0.01 to 5 mass%, more preferably 0.1 to 3 mass%, based on 100 mass% of the inorganic filler.

The resin composition for use in the prepreg preferably further contains an epoxy resin and a curing agent. Accordingly, in a preferred embodiment, the prepreg is formed by impregnating a fiber substrate with a resin composition containing an epoxy resin, a curing agent and an inorganic filler.

- Epoxy resin -

The epoxy resin is not particularly limited, but an epoxy resin having two or more epoxy groups in one molecule is preferable. Specific examples thereof include bisphenol type epoxy resins such as bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins and bisphenol AF type epoxy resins, phenol novolak type epoxy resins, tert-butyl-catechol type epoxy resins, Naphthalene type epoxy resin, naphthalene type epoxy resin, glycidylamine type epoxy resin, glycidyl ester type epoxy resin, cresol novolak type epoxy resin, biphenyl type epoxy resin, anthracene type epoxy resin , Linear aliphatic epoxy resins, epoxy resins having a butadiene structure, alicyclic epoxy resins, heterocyclic epoxy resins, spirocyclic epoxy resins, cyclohexanedimethanol type epoxy resins, trimethylol type epoxy resins, and halogenated epoxy resins . The epoxy resin may be used singly or in combination of two or more kinds.

Among them, bisphenol type epoxy resins (preferably bisphenol A type epoxy resins, bisphenol F type epoxy resins), naphthol type epoxy resins, naphthalene type epoxy resins, biphenyl type epoxy resins , A naphthylene ether type epoxy resin, a glycidyl ester type epoxy resin, an anthracene type epoxy resin, and an epoxy resin having a butadiene structure. Particularly, it is preferable that the epoxy resin is at least one selected from the group consisting of bisphenol epoxy resin (preferably bisphenol A epoxy resin, bisphenol F epoxy resin), naphthol epoxy resin, naphthalene epoxy resin, biphenyl epoxy resin and naphthylene ether epoxy resin And at least one selected from the group consisting of Specific examples thereof include bisphenol A type epoxy resin ("jER828EL" and "YL980" manufactured by Mitsubishi Chemical Corporation), bisphenol F type epoxy resin ("jER806H" and "YL983U" manufactured by Mitsubishi Chemical Corporation) ), Naphthalene type bifunctional epoxy resin ("HP4032", "HP4032D", "HP4032SS", "EXA4032SS" manufactured by DIC Corporation), naphthalene type tetrafunctional epoxy resin (HP4700, ), Naphthol type epoxy resin ("ESN-475V" manufactured by Shinnitsu Kagaku KK), epoxy resin having a butadiene structure ("PB-3600" manufactured by Daicel Chemical Industries, Ltd.), biphenyl type epoxy resin NC3000L "," NC3100 "," YX4000 "," YX4000H "," YX4000HK ", and" YL6121 "manufactured by Mitsubishi Kagaku Co., Ltd.), anthracene type epoxy resin EXA-7311 "," EXA-7311L "," EXA-7311G3 ", and" EXA-7311G3 "manufactured by DIC Corporation) EXA-7311G4 "), glycidyl ester type epoxy resin (manufactured by Nagase ChemteX Co. Preparation" EX711 ", and the like" EX721 ", Ltd Printech manufacture" R540 ").

The epoxy resin preferably contains an epoxy resin having two or more epoxy groups in one molecule. When the nonvolatile component of the epoxy resin is 100% by mass, it is preferable that at least 50% by mass or more of the epoxy resin is an epoxy resin having two or more epoxy groups in one molecule.

From the viewpoint of improving the followability of the prepreg with respect to the surface unevenness of the inner layer circuit board, it is preferable that the epoxy resin contains an epoxy resin (hereinafter also referred to as &quot; liquid epoxy resin &quot;) which is liquid at a temperature of 20 캜. From the viewpoint of improving the followability of the prepreg to the surface unevenness of the inner layer circuit board and at the same time improving the curing properties of the insulating layer formed by thermally curing the prepreg, the epoxy resin is preferably a mixture of a liquid epoxy resin and an epoxy (Hereinafter also referred to as &quot; solid epoxy resin &quot;). As the liquid epoxy resin, a liquid epoxy resin having two or more epoxy groups in one molecule is preferable, and an aromatic liquid epoxy resin having two or more epoxy groups in one molecule is more preferable. As the solid epoxy resin, a solid epoxy resin having three or more epoxy groups in a molecule is preferable, and an aromatic solid epoxy resin having three or more epoxy groups in one molecule is more preferable. In the present invention, an aromatic epoxy resin means an epoxy resin having an aromatic ring in its molecule.

Examples of the liquid epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenol novolac type epoxy resin, glycidyl ester type epoxy resin and naphthalene type epoxy resin, and examples thereof include bisphenol A type epoxy resin, bisphenol F Type epoxy resin, and naphthalene type epoxy resin are preferable. The liquid epoxy resin may be used singly or in combination of two or more kinds. Examples of solid epoxy resins include naphthalene type tetrafunctional epoxy resins, cresol novolak type epoxy resins, dicyclopentadiene type epoxy resins, trisphenol epoxy resins, naphthol type epoxy resins, anthracene type epoxy resins, biphenyl type epoxy resins, naphthylene Ether type epoxy resin, and the like. Of these, naphthalene type tetra-functional epoxy resin, naphthol type epoxy resin, biphenyl type epoxy resin and naphthylene ether type epoxy resin are more preferable. The solid epoxy resin may be used singly or in combination of two or more kinds.

When a liquid epoxy resin and a solid epoxy resin are used in combination as the epoxy resin, the mixing ratio (liquid epoxy resin: solid epoxy resin) of the epoxy resin is preferably from 1: 0.1 to 1: More preferably in the range of 1: 0.6 to 1: 6, more preferably in the range of 1: 0.9 to 1: 5.5, still more preferably in the range of 1: Do.

The epoxy equivalent of the epoxy resin is preferably 50 to 3000, more preferably 80 to 2000, still more preferably 110 to 1000. On the other hand, the epoxy equivalent can be measured in accordance with JIS K 7236, and is the mass of the resin containing one equivalent of epoxy group.

The content of the epoxy resin in the resin composition is preferably from 3 to 40 mass%, more preferably from 5 to 35 mass%, and further preferably from 10 to 30 mass%. The content of the liquid epoxy resin in the resin composition is preferably 1 to 35 mass%, more preferably 3 to 30 mass%, and more preferably 6 to 25 mass%, in view of improving the followability of the prepreg with respect to the surface unevenness of the inner layer circuit board % Is more preferable.

- hardener -

The curing agent is not particularly limited as long as it has a function of curing an epoxy resin, and examples thereof include phenol-based curing agents, active ester-based curing agents, cyanate ester-based curing agents, benzoxazine based curing agents and acid anhydride-based curing agents . The curing agent may be used singly or in combination of two or more kinds. In a preferred embodiment, the curing agent is at least one selected from the group consisting of a phenol-based curing agent, an active ester-based curing agent, and a cyanate ester-based curing agent.

The phenol-based curing agent is not particularly limited, but a biphenyl-type curing agent, a naphthalene-type curing agent, a phenol novolak type curing agent, a naphthylene ether type curing agent and a triazine skeleton-containing phenol type curing agent are preferable. The phenolic curing agent may be used alone or in combination of two or more.

As a commercially available product of the phenol-based curing agent, there can be used a biphenyl-type curing agent MEH-7700, MEH-7810, MEH-7851 (manufactured by Nippon Kayaku Co., EXB9500 and HPC9500 (manufactured by DIC Corporation), phenol novolak type curing agent TD2090 (manufactured by DIC Corporation), SN170, SN180, SN190, SH475, SN485, SN495, SN375, SN395 (manufactured by Shinnitetsu Kagaku Co., EXB-6000 (manufactured by DIC Corporation) as a naphthylene ether type curing agent, and LA3018, LA7052, LA7054 and LA1356 (manufactured by DIC Corporation) as a phenol type curing agent containing a triazine skeleton. , A naphthalene type curing agent, and a phenazine type curing agent containing a triazine skeleton.

The active ester-based curing agent is not particularly limited, but generally includes ester groups having high reactivity such as phenol esters, thiophenol esters, N-hydroxyamine esters, and esters of heterocyclic hydroxy compounds, Are preferably used. The active ester curing agent is preferably obtained by condensation reaction of a carboxylic acid compound and / or a thiocarboxylic acid compound with a hydroxy compound and / or a thiol compound. From the viewpoint of heat resistance improvement, an active ester type curing agent obtained from a carboxylic acid compound and a hydroxy compound is preferable, and an active ester type curing agent obtained from a carboxylic acid compound and a phenol compound and / or a naphthol compound is more preferable. Examples of the carboxylic acid compound include benzoic acid, acetic acid, succinic acid, maleic acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid and pyromellitic acid. Examples of the phenol compound or naphthol compound include hydroquinone, resorcin, bisphenol A, bisphenol F, bisphenol S, phenolphthalein, methylated bisphenol A, methylated bisphenol F, methylated bisphenol S, phenol, o- Cresol, catechol, alpha -naphthol, beta -naphthol, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, dihydroxybenzophenone, Trihydroxybenzophenone, tetrahydroxybenzophenone, fluoroglucine, benzene triol, dicyclopentadiene type diphenol, phenol novolac, and the like.

Examples of the active ester type curing agent include active ester type curing agents containing a dicyclopentadiene type diphenol structure, active ester type curing agents containing a naphthalene structure, active ester type curing agents being acetylates of phenol novolac, Among these, from the viewpoints of lowering the melt viscosity of the prepreg and improving the followability to the surface unevenness of the inner-layer circuit board, active esters containing a dicyclopentadiene-type diphenol structure A tin curing agent is more preferable. Meanwhile, in the present invention, the "dicyclopentadiene-type diphenol structure" refers to a divalent structural unit comprising phenylene-dicyclopentalene-phenylene. The active ester type curing agents may be used singly or in combination of two or more kinds.

Examples of commercially available active ester curing agents include EXB9451, EXB9460, EXB9460S-65T and HPC8000-65T (manufactured by DIC Corporation) as the active ester curing agent containing a dicyclopentadiene type diphenol structure, acetylated products of phenol novolak YLH1026 (manufactured by Mitsubishi Chemical Corp.), YLH1030 (manufactured by Mitsubishi Chemical Corp.) as the active ester type curing agent which is a benzoylate of phenol novolak, DC808 (manufactured by Mitsubishi Chemical Corporation) as the active ester type curing agent, And YLH1048 (manufactured by Mitsubishi Chemical Corporation).

The cyanate ester-based curing agent is not particularly limited, and examples thereof include cyanate ester-based curing agents, novolac-type (phenol novolac type, alkylphenol novolak type and the like) cyanate ester-based curing agents, dicyclopentadiene- (Bisphenol A type, bisphenol F type, bisphenol S type, etc.) cyanate ester type curing agents, and partially triarylated prepolymers thereof. The weight average molecular weight of the cyanate ester curing agent is not particularly limited, but is preferably 500 to 4,500, and more preferably 600 to 3,000.

Specific examples of the cyanate ester curing agent include bisphenol A dicyanate, polyphenol cyanate (oligo (3-methylene-1,5-phenylene cyanate)), 4,4'-methylene bis , 6-dimethyl phenyl cyanate), 4,4'-ethylidenediphenyl dicyanate, hexafluorobisphenol A dicyanate, 2,2-bis (4-cyanate) phenyl propane, (4-cyanate phenylmethane), bis (4-cyanate-3,5-dimethylphenyl) methane, 1,3- Bifunctional cyanate resins derived from bifunctional cyanate resins such as bis (4-cyanate phenyl) thioether and bis (4-cyanate phenyl) ether, phenol novolak, cresol novolak, dicyclopentadiene- Resins, prepolymers in which these cyanate resins are partially triarized, and the like. The cyanate ester curing agent may be used singly or in combination of two or more kinds.

Examples of commercially available cyanate ester curing agents include PT30 (manufactured by Lonja Japan Co., Ltd.) as a phenol novolak type polyfunctional cyanate ester resin, BA230 (manufactured by Mitsubishi Chemical Corporation) as a prepolymer in which part or all of bisphenol A dicyanate is tri- (Manufactured by Lonza Japan K.K.), dicyclopentadiene structure-containing cyanate ester resins such as DT-4000 and DT-7000 (manufactured by Lonza Japan K.K.), and the like.

Specific examples of the benzoxazine type curing agent include "HFB2006M" manufactured by Shawako Co., Ltd., "P-d" and "F-a" manufactured by Shikoku Kasei Co., The benzoxazine-based curing agent may be used alone or in combination of two or more.

Examples of the acid anhydride-based curing agent include anhydride phthalic acid, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylnadic acid anhydride, hydrogenated methylnadic anhydride, trialkyltetrahydro Dicarboxylic anhydride, anhydrous phthalic acid, dodecenylmixerous acid, 5- (2,5-dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexene-1,2-dicarboxylic acid anhydride, 1, 3'-4,4'-diphenylsulfonetetracarboxylic acid dianhydride, 1, 3'-4,4'-diphenylsulfonetetracarboxylic acid dianhydride, pyromellitic acid, benzophenonetetracarboxylic acid dianhydride, biphenyltetracarboxylic acid dianhydride, naphthalenetetracarboxylic acid dianhydride, oxydiphthalic acid dianhydride, 3,3a, 4,5,9b-hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [ Glycol bis (anhydrotrimellitate), a copolymer of styrene and maleic acid And polymeric acid anhydrides such as terephthalic acid and maleic acid resin. The acid anhydride-based curing agent may be used singly or in combination of two or more kinds.

The mixing ratio of the epoxy resin and the curing agent is preferably such that the number of reactors of the curing agent is in the range of 0.3 to 2.0 when the number of epoxy groups of the epoxy resin is 1, more preferably in the range of 0.3 to 1.5, Is more preferable. The epoxy group suspension of the epoxy resin is a value obtained by dividing the solid content of each epoxy resin contained in the resin composition by the epoxy equivalent, in terms of all epoxy resins. The reactor water of the curing agent is a value obtained by dividing the value obtained by dividing the solid content of each curing agent contained in the resin composition by the equivalent of the reactor with respect to all the curing agents.

The resin composition for use in the prepreg may further contain additives such as a thermoplastic resin, a curing accelerator, a flame retardant and rubber particles, if necessary.

- Thermoplastic resin -

The resin composition to be used in the prepreg may contain a thermoplastic resin from the viewpoint of forming an insulating layer having an appropriate roughened surface by roughening the surface after the prepreg is cured. Examples of the thermoplastic resin include phenoxy resin, polyvinyl acetal resin, polyolefin resin, polybutadiene resin, polyimide resin, polyamideimide resin, polyether sulfone resin, polyphenylene ether resin and polysulfone resin. . The thermoplastic resin may be used singly or in combination of two or more kinds.

The weight average molecular weight of the thermoplastic resin in terms of polystyrene is preferably in the range of 8,000 to 70,000, more preferably in the range of 10,000 to 60,000, still more preferably in the range of 15,000 to 60,000, and still more preferably in the range of 20,000 to 60,000. The weight average molecular weight of the thermoplastic resin in terms of polystyrene is measured by a gel permeation chromatography (GPC) method. Concretely, the weight average molecular weight of the thermoplastic resin in terms of polystyrene was measured using LC-9A / RID-6A manufactured by Shimadzu Corporation, Shodex K-800P / K- 804L / K-804L can be measured using a calibration curve of standard polystyrene at a column temperature of 40 占 폚 using chloroform or the like as the mobile phase.

Examples of the phenoxy resin include bisphenol A skeleton, bisphenol F skeleton, bisphenol S skeleton, bisphenol acetophenone skeleton, novolac skeleton, biphenyl skeleton, fluorene skeleton, dicyclopentadiene skeleton, norbornene skeleton, A phenoxy resin having at least one skeleton selected from the group consisting of a skeleton, an anthracene skeleton, an adamantane skeleton, a terpene skeleton, and a trimethyl cyclohexane skeleton. The terminal of the phenoxy resin may be any functional group such as a phenolic hydroxyl group or an epoxy group. The phenoxy resin may be used singly or in combination of two or more kinds. Specific examples of the phenoxy resin include "1256" and "4250" (both phenol resins containing a bisphenol A skeleton), "YX8100" (phenoxy resin containing a bisphenol S skeleton), and "YX6954" (Phenoxy resin containing a bisphenol acetophenone skeleton). In addition, "FX280" and "FX293" manufactured by Totogassei Co., Ltd., "YL7553", "YL6794" YL7213 &quot;, &quot; YL7290 &quot;, and &quot; YL7482 &quot;.

Specific examples of the polyvinyl acetal resin include DENKA BUTYRAL 4000-2, 5000-A, 6000-C, 6000-EP manufactured by Denki Kagaku Kogyo K.K., , BX series, KS series, BL series, BM series and the like.

Specific examples of the polyimide resin include "Rika Coat SN20" and "Rika Coat PN20" manufactured by Shin-Nihon Rika K.K. Specific examples of the polyimide resin include linear polyimides (described in JP-A No. 2006-37083) obtained by reacting bifunctional hydroxyl-terminated polybutadiene, diisocyanate compound and tetrabasic acid anhydride, polysiloxane skeleton And modified polyimides such as polyimide containing polyimide (Japanese Patent Application Laid-Open No. 2002-12667 and Japanese Patent Application Laid-Open No. 2000-319386).

Specific examples of the polyamide-imide resin include "Viromax HR11NN" and "Viromax HR16NN" manufactured by Toyo Boseki K.K. Specific examples of the polyamideimide resin include modified polyamideimide such as polyamideimide "KS9100" and "KS9300" containing polysiloxane skeleton manufactured by Hitachi Chemical Co., Ltd.

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

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

The content of the thermoplastic resin in the resin composition is preferably 0.1 to 60 mass%, more preferably 0.1 to 50 mass%, still more preferably 0.5 to 30 mass%, still more preferably 0.5 to 10 mass%.

- Curing accelerator -

The resin composition used for the prepreg may contain a curing accelerator from the viewpoint of smoothly progressing the thermal curing of the prepreg. Examples of the curing accelerator include phosphorus hardening accelerator, amine hardening accelerator, imidazole hardening accelerator, guanidine hardening accelerator and the like. The curing accelerator may be used singly or in combination of two or more kinds.

The content of the curing accelerator in the resin composition is preferably 0.01 to 3% by mass, more preferably 0.01 to 2% by mass, more preferably 0.01 to 3% by mass, 0.01 to 1% by mass.

- Flame retardant -

The resin composition used for the prepreg may contain a flame retardant agent from the viewpoint of improving the flame retardancy. Examples of the flame retardant include an organic phosphorus flame retardant, an organic nitrogen-containing phosphorus compound, a nitrogen compound, a silicon-based flame retardant, a metal hydroxide, and the like. Examples of the organophosphorus flame retardant include phenanthrene-type phosphorus compounds such as HCA, HCA-HQ and HCA-NQ manufactured by Sanko Co., Ltd., phosphorus-containing benzoxazine compounds such as HFB-2006M manufactured by Showa Kogyo Co., TPPO, PPQ (manufactured by Hokko Chemical Industry Co., Ltd.), TPPO, TPP, TPP, TPP, , OP930 (manufactured by Clariant), and PX200 (manufactured by Daihachi Kagaku Co., Ltd.). Examples of the organic nitrogen-containing phosphorus compound include phosphate ester amide compounds such as SP670 and SP703 manufactured by Shikoku Chemical Industry Co., Ltd., SPB100, SPE100 manufactured by Otsuka Chemical Co., Ltd., and FP-series manufactured by FUSEMIZEKAISHO CO., LTD. Phosphazene compounds, and the like. Examples of the metal hydroxide include magnesium hydroxide such as UD65, UD650 and UD653 manufactured by Ube Industries, Ltd., B-30, B-325, B-315, B-308, B- And aluminum hydroxide such as UFH-20. The flame retardant may be used alone, or two or more flame retardants may be used in combination. The content of the flame retardant in the resin composition is not particularly limited, but is preferably 0.5 to 10% by mass, more preferably 1 to 9% by mass.

- rubber particles -

The resin composition for use in the prepreg may contain rubber particles from the viewpoint of forming an insulating layer having an appropriate roughened surface by roughening the surface after the prepreg is cured. As the rubber particles, those which do not dissolve in the later-described organic solvent and are not compatible with the above-mentioned epoxy resin, curing agent, thermoplastic resin and the like are used. Generally, such rubber particles are prepared by increasing the molecular weight of the rubber component to a level that does not dissolve in an organic solvent or a resin, thereby forming a granular phase.

Examples of the rubber particles include core-shell type rubber particles, crosslinked acrylonitrile-butadiene rubber particles, crosslinked styrene-butadiene rubber particles, acrylic rubber particles and the like. The core-shell-type rubber particles are rubber particles having a core layer and a shell layer. For example, the core-shell rubber particles may be a two-layer structure in which the shell layer of the outer layer is composed of a glassy polymer and the core layer of the core layer is composed of a rubber- A three-layer structure composed of a glassy polymer, an intermediate layer made of a rubbery polymer and a core layer made of a glassy polymer, and the like. The glassy polymer is composed of, for example, a methyl methacrylate polymer or the like, and the rubbery polymer layer is composed of, for example, a butyl acrylate polymer (butyl rubber). Specific examples of the core-shell type rubber particles include star filloids AC3832, AC3816N, IM-401 1, IM-401 7-17 (manufactured by Kanto Kasei Co., Ltd.), Metablen KW-4426 (manufactured by Mitsubishi Rayon Co., ). Specific examples of crosslinked acrylonitrile butadiene rubber (NBR) particles include XER-91 (average particle diameter 0.5 mu m, manufactured by JSR Corporation). Specific examples of the crosslinked styrene butadiene rubber (SBR) particles include XSK-500 (average particle diameter 0.5 mu m, manufactured by JSR Corporation). Specific examples of the acrylic rubber particles include Metablen W300A (average particle diameter 0.1 mu m) and W450A (average particle diameter 0.2 mu m) (manufactured by Mitsubishi Rayon Co., Ltd.). The rubber particles may be used alone, or two or more rubber particles may be used in combination.

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

- Other ingredients -

The resin composition for use in the prepreg may contain other components as required. Examples of the other components include thermosetting resins such as vinyl benzyl compounds, acrylic compounds, maleimide compounds and block isocyanate compounds, organic fillers such as silicone powder, nylon powder and fluorine powder, thickeners such as allene and benton, , Antifoaming agents or leveling agents of high molecular weight type, imidazole type coupling agents, thiazole type coupling agents, triazole type coupling agents and silane type coupling agents, phthalocyanine blue, phthalocyanine green, iodine green, A coloring agent such as yellow, carbon black and the like.

The resin composition for use in the prepreg may be prepared by appropriately mixing the respective components described above and further mixing them with a kneading means (3 rolls, a ball mill, a bead mill, a sand mill or the like) or a stirring means (super mixer, planetary mixer Or the like).

The method for producing the carrier-loaded prepreg is not particularly limited, and examples thereof include a solvent method and a hot-melt method, and at least one method selected from the group consisting of the following methods (i) to (iv)

(i) a method of temporarily coating a resin composition on a carrier film without dissolving the resin composition in an organic solvent and then laminating the resin composition on the fiber substrate

(ii) a method in which a resin composition is applied directly onto a fiber substrate by a die coater or the like to form a prepreg, and then a prepreg is laminated on the carrier film

(iii) a method of preparing a resin varnish in which a resin composition is dissolved in an organic solvent, immersing, impregnating and drying the fiber substrate with a resin varnish to form a prepreg, and then laminating a prepreg on the carrier film

(iv): a method in which a resin varnish is applied directly onto a carrier film using a die coater or the like to form a resin composition layer, and a method of laminating the resin composition layer from both sides of the fiber substrate

When a resin varnish is used, examples of the organic solvent include ketones such as acetone, methyl ethyl ketone and cyclohexanone, ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate and carbitol acetate Aromatic hydrocarbons such as toluene and xylene; amide solvents such as dimethylformamide, dimethylacetamide and N-methylpyrrolidone; and the like. The organic solvent may be used singly or in combination of two or more kinds.

The drying of the resin varnish may be carried out by a known drying method such as heating or hot air blowing. The drying conditions are not particularly limited, but it is necessary for the prepreg to have fluidity (flow property) and adhesiveness in a method for producing a multilayer printed wiring board to be described later. Therefore, when drying the resin varnish, it is important not to advance the curing of the resin composition as far as possible. On the other hand, if a large amount of organic solvent remains in the prepreg, it may cause expansion after curing. Thus, the organic solvent is dried so that the amount of residual organic solvent in the prepreg is usually 5 mass% or less, preferably 2 mass% or less. Although it depends on the boiling point of the organic solvent in the resin varnish, when a varnish containing, for example, 30 to 60 mass% of organic solvent is used, drying is preferably carried out at 80 to 180 ° C for 3 to 20 minutes.

The carrier mounting prepreg used in the method of the present invention is formed by providing a prepreg on the carrier film as described above. Thus, in one embodiment, the carrier mounting prepreg includes a carrier film and a prepreg for bonding with the carrier film. In the carrier mounting prepreg, an ultra-thin resin layer may be included between the carrier film and the prepreg. Accordingly, in another embodiment, the carrier mounting prepreg includes a carrier film, an ultra-thin resin layer that is bonded to the carrier film, and a prepreg that is bonded to the ultra-thin resin layer. Here, the ultra-thin resin layer refers to a resin layer (insulating layer) having a thickness of 1 to 10 mu m which contains no fiber substrate.

In the carrier mounting prepreg, a protective film corresponding to the carrier film may be further laminated on the surface of the prepreg not bonded to the carrier film (that is, the surface opposite to the carrier film). By laminating a protective film, it is possible to prevent adhesion and scratches of dust or the like to the surface of the prepreg. When a multilayer printed wiring board is produced, the protective film can be used by peeling off.

In the carrier mounting prepreg, the thickness of the prepreg is preferably 100 占 퐉 or less, more preferably 90 占 퐉 or less from the viewpoint of thinning the insulating layer to reduce the thickness of the multilayer printed wiring board, More preferably not more than 70 mu m, particularly preferably not more than 60 mu m or not more than 50 mu m. The lower limit of the thickness of the prepreg is preferably 20 占 퐉 or more, and more preferably 30 占 퐉 or more, from the viewpoint of ensuring the desired mechanical strength as a prepreg.

In the carrier mounting prepreg, when the total mass of the prepreg is 100 mass%, the total mass of the fibrous base material and the inorganic filler in the prepreg is 70 mass% or more. As described above, the present inventors have found that when the total content of the fibrous base material and the inorganic filler in the prepreg is high, the thermal expansion coefficient of the resulting insulating layer can be suppressed to a low level, while it is difficult to obtain an insulating layer having a smooth surface have. Although the details will be described later, according to the method for producing a multilayered printed circuit board of the present invention, even when a prepreg having a total content of the fibrous base material and the inorganic filler of 70% by mass or more is used, .

In the carrier mounting prepreg, the content ratio of the fibrous base material and the inorganic filler in the prepreg (mass ratio of fibrous base / inorganic filler) is preferably controlled to 0.2 to 2.5 from the viewpoint of achieving mechanical strength and thinning of the prepreg Do. The content ratio is more preferably 2.3 or less, more preferably 2.1 or less, still more preferably 2.1 or less, from the viewpoint that the thermal expansion coefficient of the insulating layer can be effectively lowered by inserting the gap of the fiber base material with a large amount of inorganic filler Is 1.9 or less, particularly preferably 1.7 or less or 1.5 or less. From the viewpoint that the increase of the melt viscosity of the resin composition is prevented and the inorganic filler is efficiently introduced into the gap of the fiber base material, the content ratio is more preferably not less than 0.25, more preferably not less than 0.3, Is 0.35 or more.

In the case of the carrier mounting prepreg used in the method of the present invention, the prepreg is a prepreg which is used in the method of the present invention, in which the prepreg is subjected to heat treatment at a temperature T2 to be described later (i.e., a heat press temperature of the step (II) in the production method of the multilayered printed circuit board of the present invention) , And a melt viscosity of 300 to 10,000 poise. By setting the melt viscosity of the prepreg at the temperature (T2) to be within this range, it is possible to advantageously realize an insulating layer having a smooth surface and a small thickness difference between the central portion of the substrate and the end portion of the substrate, . The melt viscosity of the prepreg at the temperature (T2) is preferably 600 poise or more, more preferably 900 poise or more, and still more preferably 900 poise or more, from the viewpoint of obtaining an insulating layer having a smaller thickness difference between the center portion of the substrate and the substrate end portion More preferably at least 1000 poise, even more preferably at least 1200 poise, particularly preferably at least 1400 poise, at least 1600 poise, at least 1800 poise, at least 2000 poise, at least 2200 poise, at least 2400 poise, at least 2600 poise, at least 2800 poise, or at least 30000 poise. The melting viscosity of the prepreg at the temperature T2 is preferably 9000 poise or less, more preferably 9000 poise or less, from the viewpoint of obtaining an insulating layer having a smoother surface and preventing air from being curled to suppress generation of voids, More preferably 8000 poise or less, still more preferably 7000 poise or less, still more preferably 6000 poise or less, particularly preferably 5000 poise or less. The melt viscosity of the prepreg at the temperature T2 can be obtained by performing dynamic viscoelasticity measurement. For example, the melt viscosity of the prepreg at temperature T2 was measured under the conditions of a measurement start temperature of 60 占 폚, a temperature raising rate of 5 占 폚 / min, a frequency of 1 Hz, a deformation of 1 deg, and a measurement temperature interval of 2.5 占 폚, Can be obtained by reading the melt viscosity at the temperature (T2) (占 폚) from the plot of the temperature and the melt viscosity. As a dynamic viscoelasticity measuring device, for example, "Rheosol-G3000" manufactured by UBM Co., Ltd. can be mentioned.

Hereinafter, the present invention will be described in detail.

[Manufacturing method of multilayer printed wiring board]

A process for producing a multilayer printed wiring board according to the present invention comprises the steps of: (I) laminating a carrier mounting prepreg on which a prepreg is formed on a carrier film, with an inner layer circuit board so that the prepreg is bonded to the innerlayer circuit board, (II) And (III) a step of thermally curing the prepreg to form an insulating layer, wherein when the total mass of the prepreg is set at 100 mass%, the amount of the fibrous substrate in the prepreg And the inorganic filler is 70 mass% or more, the melt viscosity of the prepreg at the hot press temperature in the step (II) is 300 to 10000 poise, and the maximum of the surface of the carrier film after the step (I) (T1) and T2 (占 폚), respectively, when the cross-sectional height Rt is less than 5 占 퐉 and the laminate temperature of step (I) is T1 Characterized in that that satisfies the relationship of 10 + T2≤T1.

&Lt; Process (I) >

In the step (I), the carrier mounting prepreg on which the prepreg is formed on the carrier film is laminated on the inner-layer circuit board so that the prepreg is bonded to the inner-layer circuit board.

The carrier mounting prepreg is as described above. The prepreg used in the method of the present invention is such that the total mass of the fibrous base material and the inorganic filler in the prepreg is 70% by mass or more when the total mass of the prepreg is 100% by mass and the heat press temperature And a melt viscosity of 300 to 10,000 poise.

In the method for producing a multilayered printed circuit board of the present invention, the term "inner layer circuit board" 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, Refers to an intermediate product which has a conductive layer (circuit conductor) patterned on its surface or both surfaces and in which a further insulating layer and a conductive layer are to be formed when producing a multilayer printed circuit board.

The thickness of the circuit conductor patterned on one side or both sides of the substrate is not particularly limited, but is preferably 70 占 퐉 or less, more preferably 60 占 퐉 or less from the viewpoint of thinning of the multilayered printed circuit board, More preferably not more than 40 mu m, particularly preferably not more than 30 mu m, not more than 20 mu m, not more than 15 mu m, or not more than 10 mu m. The lower limit of the thickness of the circuit conductor is not particularly limited, but is preferably 1 占 퐉 or more, more preferably 3 占 퐉 or more, and further preferably 5 占 퐉 or more.

The line / space ratio of the patterned circuit conductor on one side or both sides of the substrate is not particularly limited, but is preferably 900/900 占 퐉 or less from the viewpoint of obtaining an insulating layer excellent in surface smoothness by suppressing undulations on the surface of the insulating layer, Preferably 700/700 탆 or less, more preferably 500/500 탆 or less, further preferably 300/300 탆 or less, still more preferably 200/200 탆 or less. Although the lower limit of the line / space ratio of the circuit conductor is not particularly limited, it is preferably 1/1 占 퐉 or more in order to improve the filling of the prepreg between the spaces.

(The area of the circuit conductor portion) / (the surface area of the inner-layer circuit board) x 100 [%]) on the surface of the inner-layer circuit board may be determined according to the desired characteristics. The circuit conductor occupancy rate is also referred to as the &quot; remaining rate &quot; when the circuit conductor is formed of copper. The circuit conductor occupancy may be distributed over the surface of the inner layer circuit board. For example, an inner-layer circuit substrate on which a region having a first circuit conductor occupation ratio and a region having a second circuit conductor occupancy ratio are formed may be used. As a general tendency, the lower the circuit conductor occupation rate, the thinner the thickness of the insulating layer formed on the inner-layer circuit board on the circuit conductor becomes. Particularly, the thinner the thickness of the prepreg used for forming the insulating layer, the greater the tendency becomes. Here, the "thickness of the insulating layer on the circuit conductor" means the thickness of the insulating layer immediately above the circuit conductor. In the present invention, since the insulating layer having a small thickness difference can be realized at the substrate end portion and the central portion of the substrate, even when a thin prepreg is used, an insulating layer exhibiting desired insulation reliability over the entire substrate can be realized have. On the other hand, in the present invention, the thickness of the insulating layer at the substrate end portion means the thickness of the insulating layer at the substrate end portion on the circuit conductor, and the thickness of the insulating layer at the center portion of the substrate means .

The lamination treatment in the step (I) can be performed, for example, by heating and pressing the carrier mounting prepreg on the inner layer circuit board so that the prepreg is bonded to the inner layer circuit board under a reduced pressure condition. Examples of the member for heating and pressing the carrier mounting prepreg to the inner layer circuit board (hereinafter also referred to as "hot pressing member") include a heated metal plate (SUS hard plate) or a metal roll (SUS roll) . It is also preferable to press the heat-press member through an elastic material such as heat-resistant rubber so that the prepreg can sufficiently follow the surface unevenness of the inner-layer circuit board, not directly press the carrier-adhered prepreg. The carrier mounting prepreg may be laminated on one side of the inner layer circuit board or may be laminated on both sides of the inner layer circuit board.

The heating temperature (hereinafter also referred to as &quot; laminate temperature &quot;) at the time of the lamination treatment is preferably 60 ° C or higher from the viewpoint of obtaining an insulating layer having a smooth surface by increasing the followability of the prepreg to the surface unevenness of the inner- More preferably 70 ° C or higher, even more preferably 80 ° C or higher, still more preferably 90 ° C or higher, particularly preferably 100 ° C or higher, 110 ° C or 120 ° C or higher. The upper limit of the laminate temperature is preferably 160 占 폚 or lower, more preferably 150 占 폚 or lower, still more preferably 140 占 폚 or lower, more preferably 150 占 폚 or lower, from the viewpoint of obtaining an insulating layer having a good balance of layer thickness by preventing the resin from leaking out. Still more preferably not higher than 130 占 폚. On the other hand, the term "laminate temperature" refers to the surface temperature of the hot pressing member, and refers to the temperature of the surface of the elastic member bonded to the carrier mounting prepreg when pressed through an elastic material such as heat resistant rubber.

The compression pressure during the lamination treatment is preferably 0.098 MPa or more, more preferably 0.29 MPa or more, still more preferably 0.29 MPa or more from the viewpoint of obtaining an insulating layer having a smooth surface by increasing the followability of the prepreg to the surface unevenness of the inner- Is not less than 0.40 MPa, and even more preferably not less than 0.49 MPa. The upper limit of the compression pressure is preferably 1.77 MPa or less, more preferably 1.47 MPa or less, further preferably 1.10 MPa or less from the viewpoint of obtaining an insulating layer having a good balance of layer thickness by preventing resin from leaking out .

The compression time in the lamination process is preferably 10 seconds or more, more preferably 15 seconds or more, further preferably 20 seconds or more, still more preferably 20 seconds or more from the viewpoint of satisfying the prepreg to the surface unevenness of the inner- It is more than 25 seconds. From the viewpoint of productivity, the upper limit of the compression time is preferably 300 seconds or less, more preferably 250 seconds or less, still more preferably 200 seconds or less, even more preferably 150 seconds or less, particularly preferably 100 seconds Or 50 seconds or less.

The degree of vacuum in the lamination treatment is preferably 0.01 hPa or more, more preferably 0.05 hPa or more, and further preferably 0.1 hPa or more, from the viewpoint of efficient lamination treatment. The upper limit of the degree of vacuum is preferably 27 hPa or less, more preferably 22 hPa or less, still more preferably 22 hPa or less, from the viewpoint of obtaining an insulating layer having a smooth surface and preventing the penetration of air into the insulating layer to suppress generation of voids Is not more than 17 hPa, and even more preferably not more than 13 hPa. On the other hand, from the viewpoint of suppressing the generation of voids, the vacuum evacuation time is preferably 20 seconds or more, more preferably 30 seconds or more, 40 seconds or more, 50 seconds or more, or 60 seconds or more.

By the step (I), a laminate including an inner layer circuit board and a carrier mounting prepreg provided so as to bond the inner layer circuit board to the prepreg is obtained. In the present invention, it is preferable that the step (I) is performed so that the maximum cross-sectional height (Rt) of the carrier film surface of the carrier mounting prepreg after the step (I) is less than 5 占 퐉 in order to obtain an insulating layer having excellent surface smoothness It is important. For example, lamination treatment conditions such as the above-mentioned laminate temperature, compression pressure, compression time and vacuum degree are manipulated according to the composition and type of prepreg and carrier film to be used so that the maximum cross-sectional height (Rt) of the surface of the carrier film is (I) is performed so as to be less than 5 mu m.

From the viewpoint of obtaining an insulating layer having excellent surface smoothness, the maximum cross sectional height (Rt) of the carrier film surface of the carrier mounting prepreg after the step (I) is preferably 4.5 탆 or less, more preferably 4 탆 or less, Mu] m or less. The lower limit of the maximum cross-sectional height (Rt) is not particularly limited, but is usually 0.1 mu m or more from the viewpoint of preventing the resin from seeping out and obtaining an insulating layer having a good balance of layer thickness.

The maximum cross-sectional height (Rt) of the carrier film surface can be measured using a non-contact surface roughing machine. A specific example of the non-contact surface roughness machine is "WYKO NT9300" manufactured by Vico Instruments.

The carrier film may be peeled off before the step of providing the conductor layer (circuit wiring) on the insulating layer obtained by curing the prepreg. For example, the carrier film may be peeled off between the step (II) and the step (II) It may be peeled off after the step (III) described later. In a preferred embodiment, the carrier film is peeled off after the step (III) to be described later. The carrier film may be peeled off manually or mechanically peeled off by an automatic peeling apparatus.

The lamination treatment of the step (I) can be performed by a commercial vacuum laminator. As a commercially available vacuum laminator, for example, a vacuum pressurized laminator manufactured by Meikishesakusho Co., Ltd., a vacuum applicator manufactured by Nichigo Morton Co., Ltd., and the like can be given.

&Lt; Process (II) >

In step (II), the laminated carrier mounting prepreg is hot pressed to smooth.

The smoothing treatment in the step (II) may be carried out, for example, by pressing a hot press member from the carrier film side. As the hot pressing member, the same member as described with respect to the process (I) may be used.

It is important to set the thermal press temperature of the step (II) to a predetermined range in order to obtain an insulating layer having a good surface smoothness and a small thickness difference between the substrate end portion and the substrate central portion and having a good balance of layer thicknesses. Specifically, when the laminate temperature of the step (I) is T1 (占 폚) and the thermal press temperature of the step (II) is T2 (占 폚), T2 Is set. From the viewpoint of obtaining a more excellent insulating layer in both the surface smoothness and the balance of the layer thickness, it is preferable that T1 and T2 satisfy the relation of T2? T1 + 5 and more preferably satisfy the relation of T2? T1. T2 is not particularly limited as long as the relationship with T1 is satisfied and the melt viscosity of the prepreg at T2 is in the above-specified range. Usually, the lower limit is 70 deg. C and the upper limit is Lt; / RTI &gt; On the other hand, the heat press temperature in the process (II) refers to the surface temperature of the heat press member, and when press through an elastic material such as heat resistant rubber, it refers to the temperature of the surface of the elastic member bonded to the carrier mounting prepreg.

The pressing pressure and the pressing time in the smoothing treatment can be the same as the lamination treatment conditions in the step (I). The smoothing process is preferably carried out under normal pressure (under atmospheric pressure).

The smoothing treatment of step (II) may be performed once or two or more times. When the smoothing treatment is carried out two or more times, it may be carried out twice or more under the same conditions or two or more times under different conditions. For example, when the smoothing process of the process (II) is performed twice, the heat press temperature in the first smoothing process is T2 (占 폚), the heat press temperature in the second smoothing process is T3 ), It is preferable that T2 and T3 satisfy a relationship of T230? T3? T2 + 20, and more preferably T2-20? T3? T2 + 10.

The smoothing treatment of the step (II) can be performed by a commercial laminator. Further, the steps (I) and (II) may be carried out continuously using the commercial vacuum laminator. For example, the step (I) and the step (II) may be successively performed using a vacuum laminator having a first chamber for the lamination treatment and a second chamber for the smoothing treatment. In the case where the smoothing process of the step (II) is performed twice or more, the smoothing process may be repeated twice or more in the second chamber, or the smoothing process may be performed in an additional chamber (for example, The third chamber, and the fourth chamber) may be used to perform the smoothing treatment twice or more.

&Lt; Process (III) >

In the step (III), the prepreg is thermally cured to form an insulating layer.

The conditions of the thermal curing are not particularly limited, and conditions that are generally employed when forming the insulating layer of the multilayer printed wiring board may be used.

For example, the thermal curing conditions of the prepreg vary depending on the composition of the resin composition used in the prepreg, and the curing temperature is in the range of 120 to 240 占 폚 (preferably in the range of 150 to 210 占 폚, 170 to 190 占 폚), and the curing time may be in the range of 5 to 90 minutes (preferably 10 to 75 minutes, and more preferably 15 to 60 minutes).

The prepreg may be preheated at a temperature lower than the curing temperature before thermosetting. For example, it is preferable to heat the prepreg for at least 5 minutes (preferably, 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) May be preheated for 5 to 150 minutes, more preferably 15 to 120 minutes. In the case of performing the preliminary heating, this preliminary heating is also included in the step (III).

The thermal curing of the prepreg in the step (III) is preferably carried out under atmospheric pressure (normal pressure).

The heat curing of the step (III) may be carried out using a heating oven. When the prepreg is thermally cured by using a heating oven, the prepreg is placed in a vertical state in a heating oven and thermally cured to form an insulating layer, whereby a large number of sheets can be put into the heating oven at a time, (II) to (III), thereby contributing to productivity improvement. As a heating oven, for example, a clean oven ("Clean Oven DE610" manufactured by Yamato Kagaku Co., Ltd.) can be used.

By the step (III), a laminate including an inner-layer circuit board and an insulating layer to be bonded to the inner-layer circuit board is obtained. As described above, in the case of using a prepreg having a high total content of the fibrous base material and the inorganic filler, the thermal expansion coefficient of the obtained insulating layer can be suppressed to a low level while the surface of the obtained insulating layer is a surface irregularity So that it is difficult to obtain an insulating layer whose surface is smooth. If the surface roughness of the insulating layer is large, there is a case where the conductor layer is formed in a fine wiring pattern on the surface of the insulating layer. The surface smoothness of the insulating layer can be improved to some extent by hot pressing under such a condition that the fluidity of the resin is increased, for example, by setting the hot press temperature in the smoothing step to be high. In such a case, A large difference in the thickness of the insulating layer obtained at the center portion of the substrate and the end portion of the substrate tends to occur. As the thickness of the multilayered printed circuit board has become thinner, recent trends toward thinning of the insulating layer have resulted in poor local balance of insulation reliability. On the other hand, according to the manufacturing method of the multilayered printed circuit board of the present invention, even when a prepreg having a high total content of the fibrous substrate and the inorganic filler is used, the surface smoothness is excellent, The insulating layer having a good balance of a small layer thickness can be formed. Therefore, the present invention significantly contributes to both micro-wiring and thinning of a multilayered printed circuit board when a multilayered printed circuit board is manufactured using a prepreg having a high total content of a fibrous base material and an inorganic filler. The multilayered printed circuit board manufactured by the method of the present invention is characterized in that the total content of the fibrous base material and the inorganic filler is high and the maximum cross sectional height (Rt) of the surface is low and the thickness of the insulating layer . The maximum sectional height (Rt) of the insulating layer surface and the difference in thickness between the substrate end portion of the insulating layer and the central portion of the substrate will be described later in detail. In one embodiment, the multilayered printed circuit board includes an insulating layer that satisfies the following conditions (a) to (c): (a) when the total mass of the insulating layer is 100 mass% , The total mass of the fibrous base material and the inorganic filler is 70 mass% or more; (b) the maximum cross-sectional height (Rt) of the surface of the insulating layer is less than 3 mu m; And (c) the difference between the thickness of the substrate end portion of the insulating layer and the thickness of the substrate central portion is less than 2.5 mu m.

The maximum cross-sectional height Rt of the surface of the insulating layer after the step (III) is preferably less than 3 mu m, more preferably 2.8 mu m or less, from the viewpoint of forming a conductor layer with a fine wiring pattern on the surface of the insulating layer More preferably 2.6 占 퐉 or less, and still more preferably 2.5 占 퐉 or less. The lower limit of the maximum cross-sectional height (Rt) is not particularly limited, but is usually 0.1 占 퐉 or more.

The maximum cross-sectional height (Rt) of the surface of the insulating layer can be measured using a non-contact surface roughness machine with respect to the exposed surface of the insulating layer after peeling off the carrier film.

The difference between the thickness of the insulating layer at the substrate end portion and the thickness of the insulating layer at the central portion of the substrate after the step (III) is preferably less than 2.5 탆 from the viewpoint of achieving the desired insulation reliability over the entire substrate, More preferably not more than 2.2 mu m, even more preferably not more than 2.0 mu m, and particularly preferably not more than 1.8 mu m or not more than 1.6 mu m. The lower limit of the thickness of the insulating layer at the substrate end portion and the thickness of the insulating layer at the central portion of the substrate is not particularly limited and may be 0 占 퐉. In the present invention, since the insulating layer having a small thickness difference can be formed at the substrate end portion and the central portion of the substrate as described above, the desired insulating reliability can be achieved over the entire substrate even when the insulating layer is thin.

The difference between the thickness of the insulating layer at the end portion of the substrate and the thickness of the insulating layer at the center portion of the substrate can be measured by using a microscope to measure the cross section of the central portion and the end portion of the layered body obtained in the step (III) Can be calculated by measuring the thickness. As a specific example of the microscope, "Microscope VK-8510" manufactured by KEYENCE Co., Ltd. can be mentioned.

<Other Processes>

(V) a step of roughening the insulating layer; (VI) a step of forming a conductive layer by plating on the surface of the roughened insulating layer; May be further included. These steps (IV) to (VI) may be carried out according to various methods known to the person skilled in the art, which are used in the production of a multilayer printed wiring board. When the carrier film is peeled off after the step (III), the peeling of the carrier film may be carried out between the step (III) and the step (IV), or between the step (IV) and the step (V).

Step (IV) is a step of perforating the insulating layer, whereby a via hole or the like can be formed in the insulating layer. The via hole is provided for electrical connection between the layers and can be formed by a known method using a drill, laser, plasma or the like in consideration of the characteristics of the insulating layer. For example, when a carrier film is present, a via hole can be formed in the insulating layer by irradiating laser light from above the carrier film.

Examples of the laser light source include a carbon dioxide gas laser, a YAG laser, and an excimer laser. Of these, a carbon dioxide gas laser is preferable from the viewpoints of processing speed and cost.

The drilling can be carried out using a commercially available laser device. Examples of commercially available carbon dioxide gas laser devices include LC-2E21B / 1C manufactured by Hitachi Biomechanics Co., ML605GTWII manufactured by Mitsubishi Denki K.K., a substrate perforated laser processing machine manufactured by Matsushita Yotsetsu System Co., .

Step (V) is a step of roughening the insulating layer. The procedure and conditions of the roughening treatment are not particularly limited, and the procedure and conditions of the steps usually used in forming the insulating layer of the multilayer printed wiring board can be employed. For example, the swelling treatment with a swelling liquid, the harmonization treatment with an oxidizing agent, and the neutralization treatment with a neutralizing liquid can be carried out in this order to roughen the insulating layer. The swelling liquid is not particularly limited, but an alkaline solution, a surfactant solution and the like can be mentioned, and an alkaline solution is preferable, and a sodium hydroxide solution and a potassium hydroxide solution are more preferable as the alkaline solution. Examples of commercially available swelling solutions include Swelling Dip, Sucurengant P, Swelling Dip, Sucuregent SBU, etc., manufactured by Atotech Japan Co., Ltd., and the like. The swelling treatment with the swelling liquid is not particularly limited, and can be performed, for example, by immersing the insulating layer in a swelling liquid at 30 to 90 캜 for 1 to 20 minutes. From the viewpoint of suppressing the swelling of the resin in the insulating layer to an appropriate level, it is preferable to immerse the insulating layer in the swelling liquid at 40 to 80 캜 for 5 seconds to 15 minutes. The oxidizing agent is not particularly limited, and for example, an alkaline permanganic acid solution obtained by dissolving potassium permanganate or sodium permanganate in an aqueous solution of sodium hydroxide may be mentioned. The roughening treatment with an oxidizing agent such as an alkaline permanganic acid solution is preferably carried out by immersing the insulating layer in an oxidizing agent solution heated to 60 to 80 캜 for 10 to 30 minutes. The concentration of the permanganate in the alkaline permanganic acid solution is preferably 5 to 10% by mass. Examples of commercially available oxidizing agents include alkaline permanganic acid solutions such as Concentrate Compact P, Doing Solution, and Sucry Gent P manufactured by Atotech Japan Co., Ltd. As the neutralization solution, an acidic aqueous solution is preferable, and commercially available products include, for example, Reduction Solution · Sucrygant P manufactured by Atotech Japan Co., Ltd. The treatment with the neutralizing liquid can be performed by immersing the treated surface subjected to the roughening treatment with the oxidizing agent solution in a neutralizing solution at 30 to 80 캜 for 5 to 30 minutes. From the standpoint of workability and the like, it is preferable to immerse the object subjected to the roughening treatment with the oxidizing agent solution in a neutralizing solution at 40 to 70 캜 for 5 to 20 minutes.

Step (VI) is a step of forming a conductor layer on the surface of the harmonized insulating layer by plating.

The conductor material used for the conductor layer is not particularly limited. In a preferred embodiment, the conductor layer contains 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 . The conductor layer may be a single metal layer or an alloy layer. Examples of the alloy layer include alloys of two or more metals selected from the above-mentioned group (for example, nickel-chromium alloy, copper-nickel alloy and copper- ). &Lt; / RTI &gt; Among them, a single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver or copper, or a nickel-chromium alloy, a copper-nickel alloy And an alloy layer of a copper-titanium alloy is preferable and a single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver or copper or an alloy layer of a nickel- chromium alloy is more preferable, Is more preferable.

The conductor layer may have a single-layer structure or a multi-layer structure in which two or more single metal layers or alloy layers made of different kinds of metals or alloys are stacked. 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.

The thickness of the conductor layer is generally 3 to 35 占 퐉, preferably 5 to 30 占 퐉, although it varies depending on the design of the desired multilayer printed wiring board.

The conductor layer can be formed by plating. For example, a conductor layer having a desired wiring pattern can be formed by plating the surface of the insulating layer by a conventionally known technique such as a semi-custom method or a pull-on-wet method. Hereinafter, an example in which the conductor layer is formed by the semi-

First, a plating seed layer is formed on the surface of the insulating layer by electroless plating. Then, a mask pattern for exposing a part of the plating seed layer corresponding to the desired wiring pattern is formed on the formed plating seed layer. A metal layer is formed on the exposed plating seed layer by electrolytic plating, and then the mask pattern is removed. Thereafter, an unnecessary plating seed layer is removed by etching or the like, and a conductor layer having a desired wiring pattern can be formed. In the method for producing a multilayered printed circuit board of the present invention, since an insulating layer having excellent surface smoothness can be formed, a conductor layer can be formed on the insulating layer with a fine wiring pattern.

The semiconductor device can be manufactured by using the multilayered printed circuit board manufactured by the method of the present invention. The semiconductor device can be manufactured by mounting the semiconductor chip in the conductive portion of the multilayered printed circuit board of the present invention. The &quot; conduction site &quot; is a &quot; location for transmitting electrical signals in the multilayered printed circuit board &quot;, and may be a surface or a buried site. The semiconductor chip is not particularly limited as long as it is an electric circuit element made of a semiconductor material.

The method of mounting the semiconductor chip when manufacturing the semiconductor device of the present invention is not particularly limited as long as the semiconductor chip effectively functions. Specifically, the semiconductor chip mounting method, the flip chip mounting method, the bump- (BBUL), a mounting method using an anisotropic conductive film (ACF), a mounting method using a non-conductive film (NCF), and the like.

[ Example ]

Hereinafter, the present invention will be described more specifically based on examples and comparative examples, but the present invention is not limited to the following examples. In the following description, &quot; part &quot; means &quot; part by mass &quot;.

First, the measurement method and evaluation method in the physical property evaluation in the present specification will be described.

[Preparation of substrate for measurement and evaluation]

(1) Fabrication of inner layer circuit board

(IPC MULTI-PURPOSE TEST BOARD NO. 2) was laminated on a glass cloth base epoxy resin double-sided copper-clad laminate (copper foil thickness 35 탆, substrate thickness 0.8 mm, "R5715ES" manufactured by Matsushita Electric Industrial Co. A comb pattern (with a residual rate of 48%) having a line / space ratio of 600/660 탆 was formed on the pattern of IPC C-25. Subsequently, both sides of the substrate were coordinated with a microetching agent ("CZ8100" To prepare an inner layer circuit board.

On the other hand, for Example 4, a glass-clad epoxy resin double-side copper-clad laminate in which the thickness of the copper foil was changed to 7 탆 was used.

(2) Laminate of carrier mounting prepreg

The carrier mounting prepreg produced in the following Production Example was applied to the inner layer circuit board so as to bond the prepreg to the inner layer circuit board by using a 2-chamber press-fitted laminator (MVLP500 / 600-IIB manufactured by Meiki Co., And laminated on both sides. The lamination treatment was carried out by reducing the pressure for 30 seconds to 13 hPa or less and then pressing the laminate at a temperature (T1) (° C) shown in Table 2 and a pressure of 0.74 MPa for 30 seconds. Meanwhile, the lamination was carried out in a first chamber of a two-chamber press-fitted laminator.

(3) Smoothing of the carrier mounting prepreg

The laminated carrier mounting prepregs were hot pressed and smoothed in a second chamber of the two-chamber press-fitted laminator. The smoothing treatment was performed under atmospheric pressure (atmospheric pressure) by pressing at a hot press temperature (T2) (° C) and a pressure of 0.55 MPa for 90 seconds as shown in Table 2.

In Example 7, the second chamber of the two-chamber presser-mounted laminator was subjected to the smoothing treatment twice. The first smoothing treatment was performed under atmospheric pressure (atmospheric pressure) by pressing at a hot press temperature (T2) (占 폚) and a pressure of 0.55 MPa for 90 seconds as shown in Table 2. The second smoothing treatment was carried out by pressing under the atmospheric pressure (atmospheric pressure) for 90 seconds at the hot press temperature T3 (° C) and the pressure of 0.55 MPa described in Table 2.

(4) Thermal curing of the prepreg

After smoothing, the substrate was heated at 180 DEG C for 30 minutes, and the prepreg was thermally cured to form an insulating layer.

&Lt; Measurement of melt viscosity of prepreg >

20 prepregs each having a thickness of 1 mm were embedded into 20 mm diameter to prepare measurement samples. The melt viscosity of the prepared test samples was measured using a dynamic viscoelasticity measuring apparatus ("Rheogel-G3000" manufactured by UBM Co., Ltd.). The dynamic viscoelasticity was measured under the measurement conditions of a temperature raising rate of 5 deg. C / min, a measurement temperature interval of 2.5 deg. C and a vibration frequency of 1 Hz, and a melt viscosity (poise) at a temperature (T2) . Cone plates were used for measurement jigs.

&Lt; Measurement of maximum cross-sectional height (Rt) of carrier film surface after lamination process >

After the carrier mounting prepreg was laminated to the inner layer circuit board, the evaluation board of 200 mm x 200 mm was cut out, and the maximum cross sectional height (Rt) of the carrier film surface of the carrier mounting prepreg was measured. The maximum cross-sectional height (Rt) of the carrier film surface was measured using a non-contact surface roughing machine ("WYKO NT9300" manufactured by Vico Instrument Co., Ltd.) with a measurement range of 0.82 mm × 1.1 mm And was obtained by the numerical value obtained. The measurement was performed with respect to the exposed surface of the carrier film in a state where the carrier film adhered to the prepreg.

&Lt; Measurement of Maximum Cross Section Height (Rt) of Insulating Layer Surface >

After the prepreg was thermally cured, the release PET film as the carrier film was peeled off to measure the maximum cross-sectional height (Rt) with respect to the exposed surface of the insulating layer. The maximum cross-sectional height (Rt) of the insulating layer surface was set to 0.82 mm x 1.1 mm by using a VSI contact mode and a 10x lens using a non-contact surface roughing machine (WYKO NT9300 manufactured by Vico Instruments Inc.) And was obtained by the numerical value obtained. On the other hand, with respect to the area where the circuit wiring of the comb pattern (with a residual rate of 48%) of the line / space ratio = 600/660 탆 was provided, To obtain the average value.

In Table 2, the case where Rt is less than 2.5 占 퐉 is defined as &quot;? &Quot;, the case of 2.5 占 퐉 or more and less than 3 占 퐉 is denoted by?, And the case of 3 占 퐉 or more is denoted by X. On the other hand, regarding Comparative Examples 1, 3 and 5, wrinkles occurred due to the occurrence of undulations based on the surface unevenness of the inner-layer circuit board, so measurement of the maximum sectional height Rt was omitted. In Comparative Example 6, since voids were generated, measurement of the maximum cross-sectional height (Rt) was omitted.

&Lt; Evaluation of Appearance of Surface of Insulating Layer >

After the prepreg was thermally cured, the release PET film as the carrier film was peeled off and the appearance of the exposed surface of the insulating layer was observed. The outer surface of the insulating layer was observed by observing the surface 3 cm 2 of the insulating layer using a microscope ("Microscope VK-8510" manufactured by KEYENCE Co., Ltd.).

In Table 2, the case of no wrinkles or voids is indicated by "O", and the case of wrinkles or voids is defined as "X".

&Lt; Measurement of Difference in Thickness of Insulating Layer at End of Board and Center of Substrate >

After the prepreg was thermally cured, the release PET film as the carrier film was peeled off, and the difference in thickness between the edge of the substrate and the center of the substrate was measured. Specifically, each area (1 cm 2) of the substrate end portion and the central portion of the substrate was smoothed by polishing and then subjected to polishing using a microscope ("Microscope VK-8510" manufactured by KEYENCE Corporation) The thickness of the insulation layer immediately above was measured.

In Table 2, the case where the difference in thickness between the end portion of the substrate and the insulating layer at the central portion of the substrate is less than 2.5 占 퐉 is defined as &quot;? &Quot;

[Production Example 1]

(1) Preparation of resin varnishes

, 15 parts of liquid bisphenol A type epoxy resin (epoxy equivalent 180, "jER828EL" manufactured by Mitsubishi Chemical Corporation), 25 parts of naphthalene type tetrafunctional epoxy resin (epoxy equivalent 163, "HP4710" 45 parts of an ether type epoxy resin (epoxy equivalent 213, "EXA-7311G4" manufactured by DIC Corporation) and 8 parts of a phenoxy resin (YL7553BH30 manufactured by Japan Epoxy Resin Co., Ltd.) were mixed with 30 parts of MEK and 30 parts of cyclohexanone 30 In a mixed solvent while stirring. 10 parts of a MEK solution having a solid content of 60% by mass of a phenazine based curing agent containing a triazine skeleton (hydroxyl equivalent of 125, LA7054 manufactured by DIC Corporation, nitrogen content of about 12% by mass), 10 parts of a naphthalene type curing agent 8 parts of a flame retardant (hydroxyl equivalent 162, HCA-HQ manufactured by Sankyo Co., Ltd., phosphorus content 9.5%) 40 parts of an MEK solution having a solid content of 60% by weight of an aminosilane coupling agent ("HPC9500" 250 parts of spherical silica (average particle diameter 1.0 mu m, manufactured by Adomex Co., Ltd., &quot; SOC4 &quot;, manufactured by Shinetsu Kagaku Kogyo Kabushiki Kaisha, "KBM-573") was uniformly mixed with a high-speed rotary mixer And dispersed to prepare a resin varnish.

(2) Preparation of carrier-loaded prepreg 1

The resin varnish obtained in the above (1) was impregnated into a fiber base material (1027 glass cloth, manufactured by ARISA and SEISAKUSHO Co., Ltd., thickness 19 탆) and dried at 110 캜 for 5 minutes in a vertical type drying furnace to prepare a prepreg. The content of the resin composition in the prepreg was 81 mass% and the thickness of the prepreg was 50 탆. Thereafter, a PET film with a release layer (&quot; PET501010 &quot;, manufactured by LINTEC CO., LTD., Thickness 38 mu m) was laminated using a batch type vacuum pressure laminator (MVLP-500 manufactured by Meikisha Sakusho Co., Laminated on both sides of the prepreg so as to be in contact with the prepreg, thereby forming the carrier mounting prepreg 1. In the carrier mounting prepreg 1, the total content of the fibrous base material and the inorganic filler in the prepreg was 72 mass%. When the evaluation substrate was manufactured, one of the PET films with a release layer (protective film) was peeled and used.

[Production Example 2]

(1) Preparation of resin varnishes

A resin varnish was prepared in the same manner as in Production Example 1.

(2) Preparation of carrier-loaded prepreg 2

The same procedure as in Production Example 1 was carried out except that a fiber substrate (1000 glass cloth made by Arisawa Seisakusho Co., Ltd., thickness 14 占 퐉) was used in place of the fiber substrate (1027 glass cloth, thickness 19 占 퐉 manufactured by Arisawa Seisakusho Co., The carrier mounting prepreg 2 was prepared in the procedure. The content of the resin composition in the prepreg was 80 mass% and the thickness of the prepreg was 33 탆. Further, in the carrier mounting prepreg 2, the total content of the fibrous base material and the inorganic filler in the prepreg was 72 mass%.

[Production Example 3]

(1) Preparation of resin varnishes

, 15 parts of liquid bisphenol A type epoxy resin (epoxy equivalent 180, "jER828EL" manufactured by Mitsubishi Chemical Corporation), 80 parts of naphthylene ether type epoxy resin (epoxy equivalent 213, "EXA-7311G4" And 8 parts of a phenoxy resin ("YL7553BH30" manufactured by Japan Epoxy Resin Co., Ltd.) were dissolved by heating in a mixed solvent of 20 parts of MEK and 20 parts of cyclohexanone with stirring. 10 parts of a MEK solution having a solid content of 60% by weight of a triazine skeleton-containing phenol resin (hydroxyl equivalent of 125, "LA7054" manufactured by DIC Corporation, nitrogen content of about 12% by weight), 10 parts of a naphthalene type curing agent 8 parts of a flame retardant (hydroxyl equivalent 162, "HCA-HQ" manufactured by Sankyo Co., Ltd., phosphorus content 9.5%) 40 parts of a 60 wt% solid solution of MEK solution 240 parts of spherical silica (average particle diameter 1.0 占 퐉, manufactured by Adomex Co., Ltd., "SOC4" manufactured by Shinetsu Kagaku Kogyo Kabushiki Kaisha, "KBM-573") was subjected to surface treatment, To prepare a resin varnish.

(2) Preparation of carrier-loaded prepreg 3

Using the resin varnish obtained in the above (1), a carrier mounting prepreg 3 was prepared in the same manner as in Production Example 1. The content of the resin composition in the prepreg was 81 mass% and the thickness of the prepreg was 50 탆. Further, in the carrier mounting prepreg 3, the total content of the fibrous base material and the inorganic filler in the prepreg was 71 mass%.

&Lt; Example 1 >

Using the carrier mounting prepreg 1, an evaluation substrate was prepared according to the procedure of [Preparation of a substrate for measurement and evaluation]. As shown in Table 2, the laminate temperature (T1) was 140 占 폚 and the hot press temperature (T2) was 140 占 폚. The evaluation results are shown in Table 2.

&Lt; Example 2 >

Using the carrier mounting prepreg 1, an evaluation substrate was prepared according to the procedure of [Preparation of a substrate for measurement and evaluation]. As shown in Table 2, the laminate temperature (T1) was 140 占 폚 and the hot press temperature (T2) was 120 占 폚. The evaluation results are shown in Table 2.

&Lt; Example 3 >

Using the carrier mounting prepreg 1, an evaluation substrate was prepared according to the procedure of [Preparation of a substrate for measurement and evaluation]. As shown in Table 2, the laminate temperature (T1) was 120 占 폚 and the hot press temperature (T2) was 120 占 폚. The evaluation results are shown in Table 2.

<Example 4>

An evaluation substrate was prepared according to the procedure of [preparation of a substrate for measurement and evaluation] using the carrier mounting prepreg 2. As shown in Table 2, the laminate temperature (T1) was 140 占 폚 and the hot press temperature (T2) was 120 占 폚. The evaluation results are shown in Table 2.

&Lt; Example 5 >

Using the carrier mounting prepreg 1, an evaluation substrate was prepared according to the procedure of [Preparation of a substrate for measurement and evaluation]. As shown in Table 2, the laminate temperature (T1) was 130 占 폚 and the hot press temperature (T2) was 110 占 폚. The evaluation results are shown in Table 2.

&Lt; Example 6 >

Using the carrier mounting prepreg 3, an evaluation substrate was prepared according to the procedure of [Preparation of a substrate for measurement and evaluation]. As shown in Table 2, the laminate temperature (T1) was 130 占 폚 and the hot press temperature (T2) was 110 占 폚. The evaluation results are shown in Table 2.

&Lt; Example 7 >

Using the carrier mounting prepreg 1, an evaluation substrate was prepared according to the procedure of [Preparation of a substrate for measurement and evaluation]. As shown in Table 2, the laminate temperature (T1) was 140 占 폚, the hot press temperature (T2) was 140 占 폚, and the hot press temperature (T3) was 120 占 폚. The evaluation results are shown in Table 2.

&Lt; Comparative Example 1 &

Using the carrier mounting prepreg 1, an evaluation substrate was prepared according to the procedure of [Preparation of a substrate for measurement and evaluation]. As shown in Table 2, the laminate temperature (T1) was 140 占 폚 and the hot press temperature (T2) was 160 占 폚. The evaluation results are shown in Table 2.

&Lt; Comparative Example 2 &

Using the carrier mounting prepreg 1, an evaluation substrate was prepared according to the procedure of [Preparation of a substrate for measurement and evaluation]. As shown in Table 2, the laminate temperature (T1) was 140 占 폚 and the hot press temperature (T2) was 100 占 폚. The evaluation results are shown in Table 2.

&Lt; Comparative Example 3 &

Using the carrier mounting prepreg 1, an evaluation substrate was prepared according to the procedure of [Preparation of a substrate for measurement and evaluation]. As shown in Table 2, the laminate temperature (T1) was 120 占 폚 and the hot press temperature (T2) was 140 占 폚. The evaluation results are shown in Table 2.

&Lt; Comparative Example 4 &

Using the carrier mounting prepreg 1, an evaluation substrate was prepared according to the procedure of [Preparation of a substrate for measurement and evaluation]. As shown in Table 2, the laminate temperature (T1) was 120 占 폚 and the hot press temperature (T2) was 100 占 폚. The evaluation results are shown in Table 2.

&Lt; Comparative Example 5 &

Using the carrier mounting prepreg 1, an evaluation substrate was prepared according to the procedure of [Preparation of a substrate for measurement and evaluation]. As shown in Table 2, the laminate temperature (T1) was 100 占 폚 and the hot press temperature (T2) was 140 占 폚. The evaluation results are shown in Table 2.

&Lt; Comparative Example 6 >

Using the carrier mounting prepreg 1, an evaluation substrate was prepared according to the procedure of [Preparation of a substrate for measurement and evaluation]. As shown in Table 2, the laminate temperature (T1) was 100 占 폚 and the hot press temperature (T2) was 100 占 폚. The evaluation results are shown in Table 2.

&Lt; Comparative Example 7 &

Using the carrier mounting prepreg 3, an evaluation substrate was prepared according to the procedure of [Preparation of a substrate for measurement and evaluation]. As shown in Table 2, the laminate temperature (T1) was 140 占 폚 and the hot press temperature (T2) was 140 占 폚. The evaluation results are shown in Table 2.

Claims (9)

(I) a step of laminating the carrier mounting prepreg, in which the prepreg is formed on the carrier film, so that the prepreg is bonded to the inner-layer circuit board,
(II) a step of hot pressing and smoothing the laminated carrier mounting prepreg, and
(III) a step of thermally curing the prepreg to form an insulating layer, the method comprising:
When the total mass of the prepreg is 100 mass%, the total mass of the fibrous base material and the inorganic filler in the prepreg is 70 mass% or more,
The melt viscosity of the prepreg at the hot press temperature in the step (II) is 300 to 10000 poise,
The maximum cross-sectional height (Rt) of the carrier film surface of the carrier mounting prepreg after step (I) is less than 5 占 퐉,
Wherein T1 and T2 satisfy a relationship of T2? T1 + 10, where T1 (° C) is the lamination temperature of the process (I) and T2 (° C) is the heat press temperature of the process (II) A manufacturing method of a printed wiring board. The method of manufacturing a multilayer printed wiring board according to claim 1, wherein T1 and T2 satisfy a relationship of T2? T1 + 5. The method for producing a multilayer printed wiring board according to claim 1, wherein the step (II) is carried out two or more times. The method for producing a multilayer printed wiring board according to claim 1, wherein the maximum cross-sectional height (Rt) of the surface of the insulating layer after the step (III) is less than 3 占 퐉. The method for producing a multilayer printed wiring board according to claim 1, wherein the prepreg further contains an epoxy resin and a curing agent. The method for producing a multilayer printed wiring board according to claim 5, wherein the prepreg is formed by impregnating a fiber substrate with a resin composition containing an epoxy resin, a curing agent and an inorganic filler. The method for producing a multilayer printed wiring board according to claim 1, wherein the carrier film is peeled off after the step (III). The method for producing a multilayer printed wiring board according to any one of claims 1 to 7, wherein in the step (III), the prepreg is placed in a vertical state in a heating oven and thermally cured to form an insulating layer. A multilayer printed wiring board comprising an insulating layer that satisfies the following conditions (a) to (c):
(a) when the total mass of the insulating layer is 100 mass%, the total mass of the fibrous base material and the inorganic filler is 70 mass% or more;
(b) the maximum cross-sectional height (Rt) of the surface of the insulating layer is less than 3 mu m; And
(c) the difference between the thickness of the substrate end portion of the insulating layer and the thickness of the central portion of the substrate is less than 2.5 mu m.