JP7120261B2 - Method for manufacturing printed wiring board and method for manufacturing semiconductor device - Google Patents

Description

The present invention relates to a method for manufacturing a printed wiring board.

Printed wiring boards, which are widely used in various electronic devices, are required to have thinner layers and finer circuit wiring in order to reduce the size and increase the functionality of electronic devices. As a technique for manufacturing a printed wiring board, a manufacturing method using a build-up method in which insulating layers and conductor layers are alternately stacked on an inner layer circuit board is known. In the build-up manufacturing method, the insulating layer is formed by, for example, laminating a resin composition layer on an inner layer circuit board using an adhesive film having a resin composition layer, and thermally curing the resin composition layer. . Next, by drilling holes in the formed insulating layer to form via holes and desmearing, removal of resin residue (smear) inside the via holes and roughening of the insulating layer surface are performed at the same time (for example, , Patent Document 1).

JP 2008-37957 A

In the build-up manufacturing method, a conductor layer is formed on the surface of the insulating layer after desmearing. At this time, if the surface roughness of the insulation layer after the desmear treatment is large, fine wiring is hindered. is desirable. For example, the surface roughness of the insulating layer can be kept low by forming the insulating layer using a resin composition having high resistance to desmear treatment. However, in such a method, the removability of smear inside the via hole (especially at the bottom of the via hole) also deteriorates.

On the other hand, if a relatively strong desmear treatment condition is adopted in order to improve the removability of smear, the roughness of the surface of the insulating layer increases, which is disadvantageous for the formation of fine wiring. Moreover, when the insulating layer is formed using a resin composition with a high inorganic filler content, the adhesion strength between the insulating layer and the conductor layer is low despite the high roughness of the surface of the insulating layer. A decreasing trend was found.

The present invention has been made in view of the above circumstances, and the problem to be solved by the present invention is that it is possible to form an insulating layer having a low roughness and high adhesion strength with a conductor layer, and to Another object of the present invention is to provide a method for manufacturing a printed wiring board which is also excellent in terms of

As a result of intensive studies on the above problem, the present inventors have found that the above problem can be solved by manufacturing a printed wiring board by the following specific method, and have completed the present invention.

That is, the present invention includes the following contents.
[1] (A) Laminating a support-attached resin sheet containing a support and a resin composition layer bonded to the support on an inner-layer circuit board such that the resin composition layer is bonded to the inner-layer circuit board. process,
(B) a step of thermosetting the resin composition layer of the support-attached resin sheet to form an insulating layer;
(C) a step of drilling the insulating layer to form a via hole;
(D) a step of performing desmear treatment;
A method for manufacturing a printed wiring board, comprising the steps of (E) peeling off the support, and (F) forming a conductor layer on the surface of the insulating layer, in this order.
[2] The method for producing a printed wiring board according to [1], wherein the desmear treatment in step (D) is wet desmear treatment, dry desmear treatment, or a combination thereof.
[3] Step (F) is
The method for producing a printed wiring board according to [1] or [2], comprising roughening the surface of the insulating layer and forming a conductor layer by wet plating the surface of the insulating layer in this order.
[4] Step (F) is
The printed wiring according to [1] or [2], comprising, in this order, forming a metal layer by dry plating on the surface of the insulating layer; and forming a conductor layer by wet plating on the surface of the metal layer. Board manufacturing method.
[5] The method for producing a printed wiring board according to any one of [1] to [4], wherein the resin composition layer of the support-attached resin sheet contains an epoxy resin, a curing agent and an inorganic filler.
[6] The method for producing a printed wiring board according to [5], wherein the curing agent contains an active ester curing agent.
[7] The method for producing a printed wiring board according to [5] or [6], wherein the inorganic filler has an average particle size of 0.01 μm to 3 μm.
[8] The content of the inorganic filler in the resin composition layer is 40% by mass to 95% by mass when the nonvolatile component of the resin composition layer is 100% by mass, [5] to [7] A method for manufacturing a printed wiring board according to any one of the above.
[9] The method for producing a printed wiring board according to any one of [5] to [8], wherein the inorganic filler is surface-treated with a surface-treating agent.
[10] A printed wiring board produced by the method according to any one of [1] to [9].
[11] A semiconductor device including the printed wiring board according to [10].

According to the present invention, it is possible to provide a method for manufacturing a printed wiring board that is capable of forming an insulating layer having low roughness and high adhesion strength to a conductor layer, and that is excellent in smear removability.

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will now be described in detail with reference to its preferred embodiments.

[Method for manufacturing printed wiring board]
The printed wiring board manufacturing method of the present invention includes the following steps (A) to (F) in this order.
(A) A step of laminating a support-attached resin sheet containing a support and a resin composition layer bonded to the support on an inner layer circuit board such that the resin composition layer is bonded to the inner layer circuit board (B) ) Step of thermosetting the resin composition layer of the resin sheet with support to form an insulating layer (C) Step of drilling the insulating layer to form via holes (D) Step of performing desmear treatment (E) Support Step of peeling (F) Step of forming a conductor layer on the surface of the insulating layer

In the present invention, "including in this order" for steps (A) to (F) includes each step (A) to (F) and each step (A) to (F) is As long as it is carried out in this order, it does not prevent other steps from being included.
The same applies hereinafter to "including in this order" referred to in the process or treatment.

<Resin sheet with support>
Before describing each step in detail, the support-attached resin sheet used in the manufacturing method of the present invention will be described.

The support-attached resin sheet used in the production method of the present invention includes a support and a resin composition layer bonded to the support.

(support)
Examples of the support include a film made of a plastic material, a metal foil (copper foil, aluminum foil, etc.), and a release paper, and a film made of a plastic material is preferably used. Examples of plastic materials include polyesters such as polyethylene terephthalate (hereinafter sometimes abbreviated as "PET") and polyethylene naphthalate (hereinafter sometimes abbreviated as "PEN"), and polycarbonate (hereinafter sometimes "PC"). may be abbreviated.), acrylic such as polymethyl methacrylate (PMMA), cyclic polyolefin, triacetyl cellulose (TAC), polyether sulfide (PES), polyether ketone, and polyimide. Among them, polyethylene terephthalate and polyethylene naphthalate are preferable, and inexpensive polyethylene terephthalate is particularly preferable. In one preferred embodiment, the support is polyethylene terephthalate film.

The support may be subjected to matte treatment or corona treatment on the surface to be bonded to the resin composition layer.

Further, as the support, a support with a release layer having a release layer on the surface to be bonded to the resin composition layer may be used. The release agent used in the release layer of the release layer-attached support includes, for example, one or more release agents selected from the group consisting of alkyd resins, polyolefin resins, urethane resins, and silicone resins. .

In the invention, a commercially available product may be used as the release layer-attached support. Commercially available products include, for example, "SK-1", "AL-5", and "AL-7" manufactured by Lintec Corporation, which are PET films having a release layer containing an alkyd resin-based release agent as a main component. and so on.

The thickness of the support is not particularly limited, but is preferably in the range of 10 μm to 70 μm, more preferably in the range of 20 μm to 60 μm. When the support is a release layer-attached support, the thickness of the release layer-attached support as a whole is preferably within the above range.

(Resin composition layer)
The resin composition used for the resin composition layer is not particularly limited as long as the cured product thereof has sufficient hardness and insulating properties. For example, a resin composition containing (a) an epoxy resin, (b) a curing agent, and (c) an inorganic filler can be used. The resin composition used for the resin composition layer may further contain additives such as a thermoplastic resin, a curing accelerator, a flame retardant and rubber particles, if necessary.

In the present invention, the content of each component constituting the resin composition is a value when the total of non-volatile components in the resin composition is 100% by mass.

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

The epoxy resin preferably contains an epoxy resin having two or more epoxy groups in one molecule. When the non-volatile component of the epoxy resin is 100 mass %, at least 50 mass % or more of the epoxy resin preferably has two or more epoxy groups in one molecule. Among them, an epoxy resin that has two or more epoxy groups in one molecule and is liquid at a temperature of 20 ° C. (hereinafter referred to as "liquid epoxy resin"), and three or more epoxy groups in one molecule, It preferably contains an epoxy resin that is solid at a temperature of 20° C. (hereinafter referred to as “solid epoxy resin”). By using both a liquid epoxy resin and a solid epoxy resin as epoxy resins, a resin composition having excellent flexibility can be obtained. Moreover, the breaking strength of the cured product of the resin composition is also improved.

As the liquid epoxy resin, bisphenol A-type epoxy resin, bisphenol F-type epoxy resin, phenol novolac-type epoxy resin, or naphthalene-type epoxy resin is preferable, and naphthalene-type epoxy resin is more preferable. Specific examples of liquid epoxy resins include "EXA4032SS" (naphthalene-type epoxy resin), "HP4032" (naphthalene-type epoxy resin), "HP4032D" (naphthalene-type epoxy resin) manufactured by DIC Corporation, and Mitsubishi Chemical Corporation. "jER828EL" (bisphenol A type epoxy resin), "jER807" (bisphenol F type epoxy resin), "jER152" (phenol novolak type epoxy resin) manufactured by Nippon Steel Chemical Co., Ltd. "ZX1059" (bisphenol A mixture of type epoxy resin and bisphenol F type epoxy resin) and the like. These may be used individually by 1 type, or may use 2 or more types together.

Solid epoxy resins include tetrafunctional naphthalene type epoxy resins, cresol novolac type epoxy resins, dicyclopentadiene type epoxy resins, trisphenol epoxy resins, naphthol novolac epoxy resins, biphenyl type epoxy resins, and naphthylene ether type epoxy resins. Preferred are tetrafunctional naphthalene type epoxy resins, biphenyl type epoxy resins, and naphthylene ether type epoxy resins. Specific examples of solid epoxy resins include "HP-4700" (tetrafunctional naphthalene type epoxy resin), "N-690" (cresol novolac type epoxy resin), "N-695" (cresol Novolac type epoxy resin), "HP-7200" (dicyclopentadiene type epoxy resin), "EXA7311" (naphthylene ether type epoxy resin), "EXA7310" (naphthylene ether type epoxy resin), "EXA7311-G3" ( naphthylene ether type epoxy resin), Nippon Kayaku Co., Ltd. "EPPN-502H" (trisphenol epoxy resin), "NC7000L" (naphthol novolac epoxy resin), "NC3000H" (biphenyl type epoxy resin), "NC3000 " (biphenyl type epoxy resin), "NC3000L" (biphenyl type epoxy resin), "NC3100" (biphenyl type epoxy resin), Tohto Kasei Co., Ltd. "ESN475" (naphthol novolac type epoxy resin), "ESN485" ( Naphthol novolak type epoxy resin), Nippon Steel Chemical Co., Ltd. "ESN475V" (naphthol novolak type epoxy resin), Mitsubishi Chemical Corporation "YX4000H" (biphenyl type epoxy resin), "YX4000HK" (Bixylenol type epoxy resin) and the like.

When a liquid epoxy resin and a solid epoxy resin are used together as epoxy resins, the ratio by mass (liquid epoxy resin: solid epoxy resin) is in the range of 1:0.1 to 1:5. preferable. By setting the amount ratio of the liquid epoxy resin to the solid epoxy resin in such a range, i) when used in the form of a resin sheet, moderate adhesiveness is provided, and ii) when used in the form of a resin sheet. iii) a cured product having sufficient breaking strength can be obtained. From the viewpoint of the above effects i) to iii), the mass ratio of the liquid epoxy resin to the solid epoxy resin (liquid epoxy resin: solid epoxy resin) is 1:0.3 to 1:4.5. is more preferred, and a range of 1:0.6 to 1:4 is even more preferred.

The content of the epoxy resin in the resin composition is preferably 3% to 35% by mass, more preferably 5% to 30% by mass, even more preferably 5% to 25% by mass, and 7% to 20% by mass. % is particularly preferred.

(b) Curing agent The curing agent is not particularly limited as long as it has a function of curing the epoxy resin. Examples include ester-based curing agents. The curing agent may be used singly or in combination of two or more.

As the phenolic curing agent and the naphtholic curing agent, a phenolic curing agent having a novolac structure or a naphtholic curing agent having a novolac structure is preferable from the viewpoint of heat resistance and water resistance. From the viewpoint of adhesion strength to the conductor layer, a nitrogen-containing phenol-based curing agent is preferable, and a triazine skeleton-containing phenol-based curing agent is more preferable. Among them, it is preferable to use a triazine skeleton-containing phenol novolac resin as the curing agent from the viewpoint of highly satisfying heat resistance, water resistance, and adhesion strength to the conductor layer.

Specific examples of phenol-based curing agents and naphthol-based curing agents include, for example, “MEH-7700”, “MEH-7810” and “MEH-7851” manufactured by Meiwa Kasei Co., Ltd., manufactured by Nippon Kayaku Co., Ltd. "NHN", "CBN", "GPH", "SN170", "SN180", "SN190", "SN475", "SN485", "SN495", "SN375", "SN395" manufactured by Tohto Kasei Co., Ltd. , "LA7052", "LA7054", "LA3018" and "LA1356" manufactured by DIC Corporation.

An active ester curing agent is also preferable from the viewpoint of increasing the adhesion strength with the conductor layer. The active ester curing agent also has the effect of reducing the roughness of the surface of the insulating layer after roughening. In other words, the active ester-based curing agent can provide an insulating layer having low roughness and high adhesion strength to the conductor layer. As described above, the active ester-based curing agent exhibits excellent effects, but on the other hand, it also has the problem of resulting in a resin residue (smear) that is difficult to remove in the desmear treatment. By adopting relatively strong desmear treatment conditions, it is possible to remove smear, but in that case, the roughness of the insulating layer surface becomes high, and the active ester curing agent is originally used. Therefore, the excellent effect that is exhibited is diminished.

Although the details will be described later, according to the method for manufacturing a printed wiring board of the present invention, it is possible to improve the smear removability while maintaining the low roughness of the insulating layer surface, and the active ester curing agent is originally used. It is possible to enjoy the excellent effects that are produced.

The active ester-based curing agent is not particularly limited, but generally contains an ester group with high reaction activity such as phenol esters, thiophenol esters, N-hydroxyamine esters, esters of heterocyclic hydroxy compounds in one molecule. A compound having two or more is preferably used. The active ester curing agent is preferably obtained by a condensation reaction between a carboxylic acid compound and/or a thiocarboxylic acid compound and a hydroxy compound and/or a thiol compound. In particular, from the viewpoint of improving heat resistance, an active ester curing agent obtained from a carboxylic acid compound and a hydroxy compound is preferred, and an active ester curing agent obtained from a carboxylic acid compound and a phenol compound and/or a naphthol compound is more preferred. Examples of carboxylic acid compounds include benzoic acid, acetic acid, succinic acid, maleic acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, and pyromellitic acid. Examples of phenol compounds or naphthol compounds include hydroquinone, resorcinol, bisphenol A, bisphenol F, bisphenol S, phenolphthalin, methylated bisphenol A, methylated bisphenol F, methylated bisphenol S, phenol, o-cresol, m- cresol, p-cresol, catechol, α-naphthol, β-naphthol, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, phloroglucine, Benzenetriol, dicyclopentadienyldiphenol, phenol novolak, and the like.

Active ester curing agents include active ester compounds containing a dicyclopentadienyldiphenol structure, active ester compounds containing a naphthalene structure, active ester compounds containing acetylated phenol novolacs, and active esters containing benzoylated phenol novolacs. A compound is preferable, and among them, an active ester compound containing a naphthalene structure and an active ester compound containing a dicyclopentadienyldiphenol structure are more preferable.

Commercially available active ester curing agents include "EXB9451", "EXB9460", "EXB9460S", and "HPC-8000-65T" (manufactured by DIC Corporation) as active ester compounds containing a dicyclopentadienyldiphenol structure. ), “EXB9416-70BK” (manufactured by DIC Corporation) as an active ester compound containing a naphthalene structure, “DC808” (manufactured by Mitsubishi Chemical Corporation) as an active ester compound containing an acetylated phenol novolak, and phenol novolac Examples of active ester compounds containing benzoyl compounds include "YLH1026" (manufactured by Mitsubishi Chemical Corporation).

Specific examples of benzoxazine-based curing agents include "HFB2006M" manufactured by Showa High Polymer Co., Ltd., and "Pd" and "Fa" manufactured by Shikoku Kasei Kogyo Co., Ltd.

Examples of cyanate ester curing agents include bisphenol A dicyanate, polyphenolcyanate (oligo(3-methylene-1,5-phenylenecyanate), 4,4′-methylenebis(2,6-dimethylphenylcyanate), 4,4 '-ethylidene diphenyl dicyanate, hexafluorobisphenol A dicyanate, 2,2-bis(4-cyanate)phenylpropane, 1,1-bis(4-cyanatophenylmethane), bis(4-cyanate-3,5-dimethyl Bifunctional cyanate resins such as phenyl)methane, 1,3-bis(4-cyanatophenyl-1-(methylethylidene))benzene, bis(4-cyanatophenyl)thioether, and bis(4-cyanatophenyl)ether, phenol Polyfunctional cyanate resins derived from novolacs, cresol novolacs, etc., and prepolymers obtained by partially triazinizing these cyanate resins, etc. Specific examples of cyanate ester curing agents include "PT30" manufactured by Lonza Japan Co., Ltd. and "PT60" (both of which are phenol novolak type polyfunctional cyanate ester resins), and "BA230" (a prepolymer in which part or all of bisphenol A dicyanate is triazined to form a trimer).

The ratio of the epoxy resin to the curing agent is [total number of epoxy groups in the epoxy resin]:[total number of reactive groups in the curing agent], and is preferably in the range of 1:0.2 to 1:2. A range of 1:0.3 to 1:1.5 is more preferred, and a range of 1:0.4 to 1:1 is even more preferred. Here, the reactive group of the curing agent is an active hydroxyl group, an active ester group, or the like, and varies depending on the type of curing agent. Further, the total number of epoxy groups in the epoxy resin is the sum of the values obtained by dividing the solid mass of each epoxy resin by the epoxy equivalent for all epoxy resins, and the total number of reactive groups in the curing agent is It is a value obtained by dividing the solid content mass of each curing agent by the reactive group equivalent and totaling all the curing agents. By setting the amount ratio of the epoxy resin to the curing agent within this range, the heat resistance of the cured product of the resin composition is improved.

As described above, the curing agent preferably contains an active ester-based curing agent from the viewpoint of obtaining an insulating layer having low roughness and high adhesion strength to the conductor layer. The proportion of the active ester-based curing agent in the total curing agent is preferably 10% or more, more preferably 30% or more, still more preferably 50% or more, and particularly 60% or more, based on the number of reactive groups of the curing agent. preferable. The upper limit of the ratio is not particularly limited, and may be 100%, but from the viewpoint of improving curing reactivity, it is preferably 90% or less, more preferably 80% or less. When using a mixture of an active ester-based curing agent and another curing agent as the curing agent, the other curing agent has a low roughness and a high adhesion strength with the conductor layer while obtaining a pot life of the composition. Phenol-based curing agents and naphthol-based curing agents are preferred from the viewpoint of realizing an insulating layer.

(c) Inorganic fillers Examples of inorganic fillers include silica, alumina, barium sulfate, talc, clay, mica powder, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, magnesium oxide, boron nitride, and boric acid. aluminum, barium titanate, strontium titanate, calcium titanate, magnesium titanate, bismuth titanate, titanium oxide, barium zirconate, calcium zirconate, and the like. Among these, silica such as amorphous silica, fused silica, crystalline silica, synthetic silica and hollow silica is particularly preferred. As silica, spherical silica is preferable. An inorganic filler may be used individually by 1 type, or may use 2 or more types together. Examples of commercially available spherical fused silica include "SOC2" and "SOC1" manufactured by Admatechs.

The average particle diameter of the inorganic filler is preferably in the range of 0.01 μm to 3 μm, more preferably in the range of 0.05 μm to 2 μm, still more preferably in the range of 0.1 μm to 1 μm, and more preferably in the range of 0.3 μm to 0.8 μm. Especially preferred. The average particle size of the inorganic filler can be measured by a laser diffraction/scattering method based on Mie scattering theory. Specifically, the particle size distribution of the inorganic filler is prepared on a volume basis using a laser diffraction/scattering particle size distribution analyzer, and the median diameter thereof can be used as the average particle size for measurement. As the measurement sample, one obtained by ultrasonically dispersing an inorganic filler in water can be preferably used. LA-500 manufactured by HORIBA, Ltd. can be used as the laser diffraction scattering type particle size distribution analyzer.

Inorganic filler is one of aminosilane-based coupling agents, epoxysilane-based coupling agents, mercaptosilane-based coupling agents, silane-based coupling agents, organosilazane compounds, titanate-based coupling agents, etc. to improve moisture resistance. Alternatively, it is preferably treated with two or more surface treatment agents. Examples of commercially available surface treatment agents include "KBM403" (3-glycidoxypropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., "KBM803" (3-mercaptopropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd. silane), Shin-Etsu Chemical Co., Ltd. "KBE903" (3-aminopropyltriethoxysilane), Shin-Etsu Chemical Co., Ltd. "KBM573" (N-phenyl-3-aminopropyltrimethoxysilane), Shin-Etsu Chemical Co., Ltd. "SZ-31" (hexamethyldisilazane) and the like.

In addition, the inorganic filler surface-treated with a surface treatment agent can be washed with a solvent (eg, methyl ethyl ketone (MEK)) to measure the amount of carbon per unit surface area of the inorganic filler. Specifically, a sufficient amount of MEK as a solvent is added to the inorganic filler surface-treated with the surface treatment agent, and ultrasonic cleaning is performed at 25° C. for 5 minutes. After removing the supernatant liquid and drying the solid content, a carbon analyzer can be used to measure the amount of carbon per unit surface area of the inorganic filler. As a carbon analyzer, "EMIA-320V" manufactured by Horiba Ltd. or the like can be used.

The amount of carbon per unit surface area of the inorganic filler is preferably 0.02 mg/m ² or more, more preferably 0.1 mg/m ² or more, and more preferably 0.2 mg/m ² from the viewpoint of improving the dispersibility of the inorganic filler. The above is more preferable. On the other hand, it is preferably 1 mg/m ² or less, more preferably 0.8 mg/m ² or less, and more preferably 0.5 mg/m ² or less in order to prevent an increase in the melt viscosity of the resin varnish or the melt viscosity in the form of a sheet. More preferred.

As described above, the present inventors have found that the adhesion strength between the insulating layer and the conductor layer tends to decrease when the insulating layer is formed using a resin composition having a high inorganic filler content. However, according to the printed wiring board manufacturing method of the present invention, sufficient adhesion strength between the insulating layer and the conductor layer can be realized even when a resin composition having a high inorganic filler content is used.

The content of the inorganic filler in the resin composition is 40 mass from the viewpoint of reducing the thermal expansion coefficient of the insulating layer and preventing the occurrence of cracks and circuit distortion due to the difference in thermal expansion between the insulating layer and the conductor layer. % or more is preferable, 50 mass % or more is more preferable, 60 mass % or more is still more preferable, and 65 mass % or more is particularly preferable.

In the method for producing a printed wiring board of the present invention, the content of the inorganic filler in the resin composition can be further increased without lowering the adhesion strength between the insulating layer and the conductor layer. For example, the content of the inorganic filler in the resin composition may be increased to 66% by mass or more, 68% by mass or more, 70% by mass or more, 72% by mass or more, or 74% by mass or more.

From the viewpoint of the mechanical strength of the insulating layer, the upper limit of the content of the inorganic filler is preferably 95% by mass or less, more preferably 90% by mass or less, and even more preferably 85% by mass or less.

In one embodiment, the resin composition used for the resin composition layer includes (a) the epoxy resin, (b) the curing agent, and (c) the inorganic filler described above. Among them, the resin composition includes (a) a mixture of a liquid epoxy resin and a solid epoxy resin as the epoxy resin (the mass ratio of liquid epoxy resin:solid epoxy resin is preferably 1:0.1 to 1:5, and more (preferably 1:0.3 to 1:4.5, more preferably 1:0.6 to 1:4); and (c) silica as an inorganic filler. From the viewpoint of being able to more advantageously form an insulating layer with low roughness and high adhesion strength to the conductor layer, (a) the epoxy resin is a mixture of a liquid epoxy resin and a solid epoxy resin (liquid epoxy resin: solid epoxy resin The mass ratio is preferably 1:0.1 to 1:5, more preferably 1:0.3 to 1:4.5, still more preferably 1:0.6 to 1:4), (b) a curing agent and (c) silica as the inorganic filler. Regarding the resin composition layer containing such a combination of specific components, the preferred contents of (a) the epoxy resin, (b) the curing agent, and (c) the inorganic filler are as described above. (a) the epoxy resin content is preferably 3% to 35% by mass, (c) the inorganic filler content is preferably 40% to 90% by mass, and (a) the epoxy resin content is 5% by mass. It is more preferable that the content of the (c) inorganic filler is 50% to 90% by mass. (b) Regarding the content of the curing agent, the ratio of (a) the total number of epoxy groups in the epoxy resin and (b) the total number of reactive groups in the curing agent is 1:0.2 to 1:2. more preferably 1:0.3 to 1:1.5, even more preferably 1:0.4 to 1:1. .

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

Examples of thermoplastic resins include phenoxy resins, polyvinyl acetal resins, polyimide resins, polyamideimide resins, polyethersulfone resins, and polysulfone resins. The thermoplastic resin may be used singly or in combination of two or more.

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

Examples of phenoxy resins include bisphenol A skeleton, bisphenol F skeleton, bisphenol S skeleton, bisphenolacetophenone skeleton, novolak skeleton, biphenyl skeleton, fluorene skeleton, dicyclopentadiene skeleton, norbornene skeleton, naphthalene skeleton, anthracene skeleton, adamantane skeleton, and terpene. and a phenoxy resin having one or more skeletons selected from the group consisting of a trimethylcyclohexane skeleton. The terminal of the phenoxy resin may be any functional group such as a phenolic hydroxyl group or an epoxy group. A phenoxy resin may be used individually by 1 type, and may combine 2 or more types. Specific examples of phenoxy resins include "1256" and "4250" manufactured by Mitsubishi Chemical Corporation (both phenoxy resins containing bisphenol A skeleton), "YX8100" (phenoxy resin containing bisphenol S skeleton), and "YX6954" ( bisphenolacetophenone skeleton-containing phenoxy resin); YL7290” and “YL7482”.

Specific examples of polyvinyl acetal resins include Denka Butyral 4000-2, 5000-A, 6000-C, and 6000-EP manufactured by Denki Kagaku Kogyo Co., Ltd., S-Lec BH series and BX series manufactured by Sekisui Chemical Co., Ltd., KS series, BL series, BM series and the like.

Specific examples of the polyimide resin include "Ricacoat SN20" and "Ricacoat PN20" manufactured by Shin Nippon Rika Co., Ltd. Specific examples of polyimide resins include linear polyimide obtained by reacting bifunctional hydroxyl-terminated polybutadiene, a diisocyanate compound and a tetrabasic acid anhydride (described in JP-A-2006-37083), and a polysiloxane skeleton. Examples include modified polyimides such as polyimide containing (described in JP-A-2002-12667 and JP-A-2000-319386).

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

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

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

The content of the thermoplastic resin in the resin composition is preferably 0.1% by mass to 20% by mass. By setting the content of the thermoplastic resin in such a range, the viscosity of the resin composition becomes appropriate, and a resin composition having uniform thickness and bulk properties can be formed. More preferably, the content of the thermoplastic resin in the resin composition is 0.5% by mass to 10% by mass.

Examples of curing accelerators include organic phosphine compounds, imidazole compounds, amine adduct compounds, and tertiary amine compounds. The content of the curing accelerator is preferably in the range of 0.05% by mass to 3% by mass when the total of the non-volatile components of (a) the epoxy resin and (b) the curing agent is 100% by mass. The curing accelerator may be used singly or in combination of two or more.

Examples of flame retardants include organic phosphorus flame retardants, organic nitrogen-containing phosphorus compounds, nitrogen compounds, silicone flame retardants, and metal hydroxides. A flame retardant may be used individually by 1 type, or may use 2 or more types together. The content of the flame retardant in the resin composition is not particularly limited, but is preferably 0.5% by mass to 10% by mass, more preferably 1% by mass to 9% by mass, and even more preferably 1% by mass to 8% by mass. .

As the rubber particles, for example, those that are insoluble in the solvent described below and incompatible with the above-described epoxy resin, curing agent, thermoplastic resin, and the like are used. Such rubber particles are generally prepared by increasing the molecular weight of the rubber component to a level that does not dissolve in solvents or resins and forming particles.

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

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

The resin composition used for the resin composition layer may contain other additives, if necessary. Such other additives include, for example, organometallic compounds such as organocopper compounds, organozinc compounds, and organocobalt compounds, as well as organic fillers, thickeners, antifoaming agents, leveling agents, adhesion imparting agents, and coloring agents. and resin additives such as curable resins.

In the support-attached resin sheet, the thickness of the resin composition layer is preferably 3 μm to 100 μm, more preferably 5 μm to 80 μm, even more preferably 20 μm to 60 μm.

In the support-attached resin sheet, the resin composition layer may have a multilayer structure consisting of two or more layers. When using a resin composition layer having a multi-layer structure, the total thickness is preferably within the above range.

A resin sheet with a support can be produced by forming a resin composition layer on a support.

A resin composition layer can be formed on the support by a known method. For example, a resin varnish is prepared by dissolving a resin composition in a solvent, this resin varnish is applied to the surface of a support using a coating device such as a die coater, and the resin varnish is dried to provide a resin composition layer. be able to.

Examples of solvents used for the preparation of resin varnishes include ketone solvents such as acetone, methyl ethyl ketone and cyclohexanone; acetic acid ester solvents such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate and carbitol acetate; Examples include carbitol solvents such as butyl carbitol, aromatic hydrocarbon solvents such as toluene and xylene, and amide solvents such as dimethylformamide, dimethylacetamide and N-methylpyrrolidone. A solvent may be used individually by 1 type, and may be used in combination of 2 or more type.

Drying of the resin varnish may be carried out by a known drying method such as heating or blowing hot air. If a large amount of solvent remains in the resin composition layer, it causes blistering after curing. Therefore, drying is performed so that the amount of residual solvent in the resin composition is usually 10% by mass or less, preferably 5% by mass or less. . Depending on the boiling point of the organic solvent in the resin varnish, for example, when using a resin varnish containing 30% by mass to 60% by mass of solvent, the resin composition layer is dried at 50 ° C. to 150 ° C. for 3 to 10 minutes. can be formed.

In the support-attached resin sheet, a protective film conforming to the support can be further laminated on the surface of the resin composition layer that is not bonded to the support (that is, the surface opposite to the support). Although the thickness of the protective film is not particularly limited, it is, for example, 1 μm to 40 μm. By laminating the protective film, it is possible to prevent dust from adhering to the surface of the resin composition layer and scratches on the surface of the resin composition layer. The support-attached resin sheet can be wound into a roll and stored, and can be used by peeling off the protective film when producing a printed wiring board.

Such a support-attached resin sheet results in an insulating layer having low roughness and excellent adhesion strength to a conductor layer, and is therefore useful for insulating layers of printed wiring boards, particularly for interlayer insulating layers.

Each step will be described below.

<Step (A)>
In step (A), a support-attached resin sheet containing a support and a resin composition layer bonded to the support is laminated on the inner layer circuit board such that the resin composition layer is bonded to the inner layer circuit board. .

The configuration of the support-attached resin sheet used in step (A) is as described above. In addition, "inner layer circuit board" means a conductive layer (circuit) patterned on one or both sides of 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, etc. and an intermediate product on which an insulating layer and a conductor layer are to be further formed when manufacturing a printed wiring board.

The lamination of the resin sheet with the support and the inner layer circuit board in step (A) may be carried out by any conventionally known method. It is preferable to perform lamination so that the inner layer circuit board is bonded to the inner layer circuit board. Among them, a vacuum lamination method in which lamination is performed under reduced pressure is more preferable. The method of lamination may be batch or continuous.

In the lamination process, generally, the pressing pressure is in the range of 1 kgf/cm ² to 11 kgf/cm ² (0.098 MPa to 1.078 MPa), the pressing temperature is in the range of 70°C to 120°C, and the pressing time is in the range of 5 seconds to 180°C. It is preferable to carry out the operation under a reduced pressure of 20 mmHg (26.7 hPa) or less with an air pressure of 20 mmHg (26.7 hPa) or less.

Lamination can be performed using a commercially available vacuum laminator. Commercially available vacuum laminators include, for example, a vacuum pressurized laminator manufactured by Meiki Seisakusho Co., Ltd., a vacuum applicator manufactured by Nichigo-Morton Co., Ltd., and the like.

In step (A), the support-attached resin sheet may be laminated on one side or both sides of the inner layer circuit board.

<Step (B)>
In step (B), the insulating layer is formed by thermosetting the resin composition layer of the resin sheet with the support.

The thermosetting conditions for the resin composition layer are not particularly limited, and conditions that are commonly used for forming insulating layers of printed wiring boards may be used.

For example, the thermosetting conditions for the resin composition layer vary depending on the type of resin composition, etc., but the curing temperature is in the range of 120° C. to 240° C. (preferably in the range of 150° C. to 210° C., more preferably in the range of 170° C. to 190° C. range), and the curing time can be in the range of 5 minutes to 90 minutes (preferably 10 minutes to 75 minutes, more preferably 15 minutes to 60 minutes).

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

<Step (C)>
In step (C), the insulating layer is drilled to form a via hole.

A via hole is provided for electrical connection between layers, and can be formed by a known method using a drill, laser, plasma, or the like, taking into account the properties of the insulating layer. For example, via holes can be formed in the insulating layer by irradiating laser light from above the support. The size of the opening of the via hole is selected according to the fineness of the component to be mounted, but the top diameter is preferably in the range of 40 μm to 500 μm.

Examples of laser light sources include carbon dioxide lasers, YAG lasers, excimer lasers, and the like. Among them, a carbon dioxide laser is preferable from the viewpoint of processing speed and cost.

When a carbon dioxide gas laser device is used as a laser light source, laser light with a wavelength of 9.3 μm to 10.6 μm is generally used. The number of shots varies depending on the depth and diameter of the via hole to be formed, but is usually selected within the range of 1 to 10 shots. From the viewpoint of increasing the processing speed and improving the productivity of printed wiring boards, the number of shots is preferably as small as possible, preferably in the range of 1 to 5 shots, more preferably in the range of 1 to 3 shots. When the number of shots is two or more, the laser light may be applied in either burst mode or cycle mode.

When a carbon dioxide gas laser device is used as the laser light source, the energy of the laser light is preferably 0.25 mJ or more, more preferably 0.5 mJ or more, although it depends on the number of shots, the depth of the via hole, and the thickness of the support. , and more preferably set to 1 mJ or more. The upper limit of the laser light energy is preferably 20 mJ or less, more preferably 15 mJ or less, and still more preferably 10 mJ or less.

Drilling can be performed using a commercially available laser device. Examples of commercially available carbon dioxide laser devices include LC-2E21B/1C manufactured by Hitachi Via Mechanics Co., Ltd., ML605GTWII manufactured by Mitsubishi Electric Corporation, and a substrate drilling laser processing machine manufactured by Matsushita Welding Systems Co., Ltd. mentioned.

<Step (D)>
In step (D), desmear treatment is performed.

Resin residue (smear) generally adheres to the inside of the via hole (especially the bottom of the via hole) formed in step (C). Such smear causes electrical connection failure between layers, so a process for removing smear (desmear process) is performed in step (D).

In the method for manufacturing a multilayer printed wiring board of the present invention, desmear treatment is performed in a state in which the support adheres to the insulating layer. Unlike the conventional technology in which desmearing is performed after peeling off the support, the surface of the insulating layer is protected by the support, so the smear inside the via hole is removed without roughening the surface of the insulating layer. be able to. Also, since there is no constraint that the surface of the insulating layer is damaged, a wide range of desmearing methods and desmearing conditions can be employed. As a result, even when using a resin composition containing an active ester curing agent that results in a resin residue (smear) that is difficult to remove in desmear treatment as the resin composition for forming the insulating layer, the insulating layer It is possible to effectively remove smear without increasing the roughness of the surface.

In the step (D), the desmear treatment can be performed by various known methods without any particular limitation. In one embodiment, desmearing may be dry desmearing, wet desmearing, or a combination thereof.

Dry desmearing includes, for example, desmearing using plasma. Regarding the desmear treatment using plasma, it is known that the adhesive strength between the insulating layer and the conductor layer tends to decrease due to the surface modification of the insulating layer caused by the plasma. In the method of the present invention in which desmearing is performed in a state, desmearing can be advantageously performed without surface modification of the insulating layer.

Desmearing using plasma can be performed using a commercially available plasma desmearing device. Among commercially available plasma desmear treatment apparatuses, suitable examples for use in manufacturing printed wiring boards include a microwave plasma apparatus manufactured by Nissin Co., Ltd., and an atmospheric pressure plasma etching apparatus manufactured by Sekisui Chemical Co., Ltd., and the like.

Dry desmearing may also be dry sandblasting, in which an abrasive is sprayed from a nozzle to abrade the object to be treated. Dry sandblasting can be carried out using commercially available dry sandblasting equipment. When a water-soluble abrasive is used as the abrasive, smears can be effectively removed by washing with water after dry sandblasting without the abrasive remaining inside the via hole.

Examples of wet desmear treatment include desmear treatment using an oxidizing agent solution. When the desmear treatment is performed using the oxidant solution, it is preferable to perform the swelling treatment with the swelling liquid, the oxidation treatment with the oxidant solution, and the neutralization treatment with the neutralization solution in this order. Examples of the swelling liquid include "Swelling Dip Securiganth P" and "Swelling Dip Securiganth SBU" manufactured by Atotech Japan Co., Ltd. be able to. The swelling treatment is preferably carried out by immersing the substrate with via holes formed therein in a swelling liquid heated to 60° C. to 80° C. for 5 to 10 minutes. As the oxidizing agent solution, an aqueous alkaline permanganate solution is preferable. For example, a solution obtained by dissolving potassium permanganate or sodium permanganate in an aqueous solution of sodium hydroxide can be mentioned. The oxidation treatment with the oxidizing agent solution is preferably carried out by immersing the substrate after the swelling treatment in the oxidizing agent solution heated to 60° C. to 80° C. for 10 minutes to 30 minutes. Examples of commercially available alkaline permanganate aqueous solutions include "Concentrate Compact P", "Concentrate Compact CP", and "Dosing Solution Security P" manufactured by Atotech Japan Co., Ltd. be done. The neutralization treatment with the neutralizing solution is preferably carried out by immersing the substrate after the oxidation treatment in the neutralizing solution at 30° C. to 50° C. for 3 to 10 minutes. As the neutralizing liquid, an acidic aqueous solution is preferable, and as a commercial product, for example, "Reduction Solution Securigant P" manufactured by Atotech Japan Co., Ltd. can be mentioned.

As the wet desmearing treatment, a wet sandblasting treatment that can polish the object to be treated by spraying an abrasive and a dispersion medium from a nozzle may also be used. Wet sandblasting can be carried out using commercially available wet sandblasting equipment.

When the dry desmear treatment and the wet desmear treatment are performed in combination, the dry desmear treatment may be performed first, or the wet desmear treatment may be performed first.

<Step (E)>
In step (E), the support is peeled off. This exposes the surface of the insulating layer.

The support may be peeled off manually or mechanically with an automatic peeler. Moreover, when a metal foil is used as the support, the metal foil may be removed by etching with an etching solution.

Since the surface of the insulating layer was protected by the support during the desmearing process in step (D), the surface of the insulating layer exposed in this step advantageously has a low roughness (the roughness value of the insulating layer surface will be described later).

<Step (F)>
In step (F), a conductor layer is formed on the surface of the insulating layer.

The conductor material used for the conductor layer is not particularly limited. In a preferred embodiment, the conductor layer contains one or more selected from the group consisting of gold, platinum, palladium, silver, copper, aluminum, cobalt, chromium, zinc, nickel, titanium, tungsten, iron, tin and indium. Contains metal. The conductor layer may be a single metal layer or an alloy layer, and the alloy layer may be, for example, an alloy of two or more metals selected from the above group (for example, a nickel-chromium alloy, a copper- nickel alloys and copper-titanium alloys). Among them, from the viewpoint of versatility of conductor layer formation, cost, ease of patterning, etc., single metal layers of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver or copper, nickel-chromium alloys, copper- Nickel alloys and copper/titanium alloy alloy layers are preferred, and single metal layers of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver or copper, or nickel/chromium alloy alloy layers are more preferred, and copper single metal layers are preferred. A metal layer is more preferred.

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 laminated. When the conductor layer has a multilayer structure, the layer in contact with the insulating layer is preferably a single metal layer of chromium, zinc or titanium, or an alloy layer of nickel-chromium alloy.

The thickness of the conductor layer is generally between 3 μm and 35 μm, preferably between 5 μm and 30 μm, depending on the desired printed wiring board design.

The conductor layer can be formed on the surface of the insulating layer using conventionally known various methods such as a full-additive method and a semi-additive method.

In one embodiment, step (F) comprises:
Roughening the surface of the insulating layer, and wet plating the surface of the insulating layer to form a conductor layer in this order (such a step is hereinafter referred to as “step (F-1)”). .

Examples of roughening treatment include dry roughening treatment and wet roughening treatment, and roughening treatment may be performed by combining these.

The dry roughening treatment can be performed in the same manner as the dry desmear treatment described above. Also, the wet roughening treatment can be performed in the same manner as the wet desmear treatment described above.

When the dry roughening treatment and the wet roughening treatment are performed in combination, the dry roughening treatment may be performed first, or the wet roughening treatment may be performed first.

Such roughening treatment is intended to roughen the exposed surface of the insulating layer, but it also has a certain effect in removing smear inside the via hole. Therefore, smears can be prevented from remaining even when the step (D) is carried out under mild conditions.

In step (F-1), after the surface of the insulating layer is roughened, the surface of the insulating layer is wet-plated to form a conductor layer.

For example, a conductor layer having a desired wiring pattern can be formed by wet plating on the surface of the insulating layer by a conventionally known technique such as a semi-additive method or a full-additive method. An example of forming a conductor layer by a semi-additive method is shown below.

First, a plating seed layer is formed on the surface of the insulating layer by electroless plating. Next, a mask pattern is formed on the formed plating seed layer to expose a portion of the plating seed layer corresponding to a desired wiring pattern. After forming a metal layer on the exposed plating seed layer by electroplating, the mask pattern is removed. After that, unnecessary plating seed layers are removed by etching or the like, and a conductor layer having a desired wiring pattern can be formed.

In another embodiment, step (F) comprises:
Forming a metal layer by dry plating on the surface of the insulating layer, and forming a conductor layer by wet plating on the surface of the metal layer in this order (hereinafter, such a step is referred to as “step (F-2 )”.).

In step (F-2), first, the surface of the insulating layer is dry-plated to form a metal layer. Examples of dry plating include physical vapor deposition (PVD) methods such as vacuum deposition, sputtering, ion plating, and laser ablation, and chemical vapor deposition (CVD) methods such as thermal CVD and plasma CVD. , sputtering is preferred. The metal layer may be formed by combining two of these dry plating methods.

Then, using the formed metal layer as a plating seed layer, the metal layer can be wet-plated by a semi-additive method to form a conductor layer.

In step (F-2), sufficient adhesion strength between the insulating layer and the conductor layer can be achieved without roughening the surface of the insulating layer. may In this case, the step (F-2) is
roughening the surface of the insulating layer;
dry plating on the surface of the insulating layer to form a metal layer; and wet plating on the surface of the metal layer to form a conductor layer, in that order.

The printed wiring board manufacturing method of the present invention can form an insulating layer (interlayer insulating layer) having low roughness and high adhesion strength to a conductor layer, and exhibits excellent smear removability. Therefore, the printed wiring board manufacturing method of the present invention does not cause an electrical connection failure between layers and significantly contributes to finer wiring of the printed wiring board.

[Printed wiring board]
Regarding the printed wiring board produced by the method of the present invention, the arithmetic mean roughness (Ra) of the surface of the insulating layer is preferably 180 nm or less, more preferably 140 nm or less, and 100 nm or less. It is more preferably 90 nm or less, 80 nm or less, 70 nm or less, or 60 nm or less, particularly preferably. Although the lower limit of the Ra value is not particularly limited, it is preferably 0.5 nm or more, more preferably 1 nm or more. The root-mean-square roughness (Rq) of the surface of the insulating layer is preferably 250 nm or less, more preferably 200 nm or less, even more preferably 150 nm or less, 130 nm or less, 110 nm or less, or 90 nm or less. is particularly preferred. Although the lower limit of the Rq value is not particularly limited, it is set to 10 nm or more, 30 nm or more, etc., in order to stabilize the adhesion strength with the conductor layer.
The arithmetic mean roughness (Ra) and root mean square roughness (Rq) of the surface of the insulating layer can be measured using a non-contact surface roughness meter. A specific example of the non-contact surface roughness meter is "WYKO NT3300" manufactured by Beeco Instruments.

The printed wiring board produced by the method of the present invention has a sufficient adhesion strength (peel strength) to the surface of the insulating layer, that is, preferably 0.4 kgf/ cm or more, more preferably 0.45 kgf/cm or more, and still more preferably 0.5 kgf/cm or more. The higher the peel strength, the better, but generally the upper limit is 1.5 kgf/cm.
The peel strength between the insulating layer and the conductor layer can be measured according to JIS C6481.

[Semiconductor device]
A semiconductor device can be manufactured using a printed wiring board manufactured by the method of the present invention.

Examples of such semiconductor devices include various semiconductor devices used in electrical appliances (e.g., computers, mobile phones, digital cameras, televisions, etc.) and vehicles (e.g., motorcycles, automobiles, trains, ships, aircraft, etc.). .

EXAMPLES The present invention will be specifically described below by way of examples, but the present invention is not limited to these examples. In the following, "parts" and "%" mean "mass parts" and "mass%", respectively, unless otherwise specified.

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

[Preparation of sample for measurement and evaluation]
(1) Surface treatment of inner layer circuit board Glass cloth-based epoxy resin double-sided copper-clad laminate (copper foil thickness 18 μm, substrate thickness 0.3 mm, Matsushita Electric Works Co., Ltd. “R5715ES”) on which an inner layer circuit is formed. Both surfaces were etched by 1 μm with “CZ8100” manufactured by MEC Co., Ltd. to roughen the copper surface.

(2) Lamination of support-attached resin sheets The support-attached resin sheets prepared in Examples and Comparative Examples are laminated using a batch-type vacuum pressure laminator ("MVLP-500" manufactured by Meiki Seisakusho Co., Ltd.). It laminated|stacked on both surfaces of the inner-layer circuit board so that a composition layer might contact|connect with an inner-layer circuit board. Lamination was carried out by reducing the pressure for 30 seconds to an air pressure of 13 hPa or less, followed by laminating at 100° C. and a pressure of 0.74 MPa for 30 seconds.

(3) Curing of Resin Composition The laminated resin sheet with support was heated at 80° C. for 30 minutes and then at 170° C. for 30 minutes to thermally cure the resin composition layer to form an insulating layer.

(4) Formation of Via Holes Using a CO ₂ laser processing machine "LC-2E21B/1C" manufactured by Hitachi Via Mechanics Co., Ltd., holes were formed in the insulating layer from above the support to form via holes. The top diameter (diameter) of the via hole on the surface of the insulating layer was 50 μm. The conditions for drilling are mask diameter 1.60 mm, focus offset value 0.050, pulse width 25 μs, energy 0.33 mJ/shot (output 0.66 W, frequency 2000 Hz), aperture 13, number of shots 2, burst mode. Met.

(5) Desmear Treatment After forming the via holes, the inner layer circuit board having the insulating layer formed thereon was subjected to desmear treatment while the support was attached. After the desmearing process, the substrate was evaluated for smear removal at the bottom of the via hole. As the desmear treatment, the following wet desmear treatment or dry desmear treatment was performed.
Wet desmear treatment:
The inner layer circuit board on which the insulating layer is formed is placed in a swelling liquid ("Swelling Dip Securigant P" manufactured by Atotech Japan Co., Ltd., an aqueous solution of diethylene glycol monobutyl ether and sodium hydroxide) at 60 ° C. for 5 minutes, and then in an oxidizing agent solution ( Atotech Japan Co., Ltd. "Concentrate Compact P", an aqueous solution with a potassium permanganate concentration of about 6% and sodium hydroxide concentration of about 4%) at 80 ° C. for 20 minutes, and finally a neutralizing solution (Atotech Japan Co., Ltd. ) manufactured by "Reduction Shoryusin Securigant P", sulfuric acid aqueous solution) at 40°C for 5 minutes, and then dried at 80°C for 15 minutes.
Dry desmear treatment:
The inner layer circuit board on which the insulating layer was formed was subjected to conditions of O ₂ /CF ₄ (mixed gas ratio) = 25/75 and a degree of vacuum of 100 Pa using a vacuum plasma etching apparatus (100-E PLASMA SYSTEM manufactured by Tepla). and treated for 5 minutes.

(6) Peeling of support The support was peeled off to expose the surface of the insulating layer.

(7) Formation of Conductor Layer A conductor layer was formed on the exposed surface of the insulating layer. The conductor layer was formed by the following wet method or dry method. The wet method below corresponds to the step (F-1) described above, and the dry method below corresponds to the step (F-2).
Wet method:
The inner layer circuit board on which the insulating layer is formed is soaked in a swelling liquid ("Swelling Dip Securigant P" manufactured by Atotech Japan Co., Ltd., an aqueous solution of diethylene glycol monobutyl ether and sodium hydroxide) at 60 ° C. for 10 minutes, and then in a roughening liquid ( Atotech Japan Co., Ltd. "Concentrate Compact P", an aqueous solution with a potassium permanganate concentration of about 6% and sodium hydroxide concentration of about 4%) at 80 ° C. for 20 minutes, and finally a neutralizing solution (Atotech Japan Co., Ltd. ) "Reduction Shoryusin Securigant P", sulfuric acid aqueous solution) at 40°C for 5 minutes, and then dried at 80°C for 30 minutes. The substrate after drying is called “evaluation substrate A”.
After that, evaluation substrate A was immersed in an electroless plating solution containing PdCl ₂ at 40° C. for 5 minutes, and then in an electroless copper plating solution at 25° C. for 20 minutes. After annealing by heating at 150° C. for 30 minutes, an etching resist is formed according to the semi-additive method, and after pattern formation by exposure and development, copper sulfate electroplating is performed to form a conductor layer with a thickness of 25 μm. formed. After forming the conductor pattern, annealing was performed by heating at 190° C. for 60 minutes. The obtained printed wiring board is called "evaluation board B".
Dry method:
In the dry method, the substrate from which the support is peeled off to expose the surface of the insulating layer is referred to as "evaluation substrate A." A titanium layer (thickness: 30 nm) and then a copper layer (thickness: 300 nm) were formed on the evaluation substrate A using a sputtering apparatus ("E-400S" manufactured by Canon Anelva Corporation). After annealing the obtained substrate by heating it at 150° C. for 30 minutes, an etching resist is formed according to the semi-additive method. A conductor layer was formed with a thickness of After forming the conductor pattern, annealing was performed by heating at 190° C. for 60 minutes. The obtained printed wiring board is called "evaluation board B".

<Measurement and Evaluation of Arithmetic Mean Roughness (Ra Value) and Root Mean Square Roughness (Rq Value)>
For the evaluation board A, using a non-contact surface roughness meter ("WYKO NT3300" manufactured by Bcoinstruments), VSI contact mode, 50x lens with a measurement range of 121 μm × 92 μm Ra value and Rq value are obtained. asked for Each was measured by calculating the average value of 10 randomly selected points.

<Measurement of adhesion strength (peel strength) between insulating layer and conductor layer>
The peel strength between the insulating layer and the conductor layer was measured for the evaluation board B according to JIS C6481. Specifically, the conductor layer of evaluation board B was cut into a portion having a width of 10 mm and a length of 100 mm. The load (kgf/cm) was measured when 35 mm was peeled off to obtain the peel strength. A tensile tester (“AC-50C-SL” manufactured by TSE Co., Ltd.) was used for the measurement.

<Evaluation of Smear Removability>
The periphery of the bottom of the via hole was observed with a scanning electron microscope (SEM), and the maximum smear length from the wall surface of the bottom of the via hole was measured from the obtained image. Smear removability was evaluated according to the following criteria.
Evaluation criteria:
○: The maximum smear length is less than 3 μm ×: The maximum smear length is 3 μm or more

[Production example 1]
(1) Preparation of resin varnish 1 Bisphenol-type epoxy resin (epoxy equivalent about 165, "ZX1059" manufactured by Nippon Steel Chemical Co., Ltd., 1:1 mixture of bisphenol A type and bisphenol F type) 5 parts, bixylenol type Epoxy resin (epoxy equivalent about 185, Mitsubishi Chemical Co., Ltd. "YX4000HK") 10 parts, biphenyl type epoxy resin (epoxy equivalent about 290, Nippon Kayaku Co., Ltd. "NC3000H") 10 parts, and phenoxy resin (Mitsubishi 10 parts of “YL7553BH30” manufactured by Kagaku Co., Ltd., a methyl ethyl ketone (MEK) solution with a solid content of 30% by mass) were heated and dissolved in 20 parts of solvent naphtha with stirring. After cooling to room temperature, 18 parts of a naphthol-based curing agent (hydroxyl equivalent 215, "SN-485" manufactured by Nippon Steel Chemical Co., Ltd., MEK solution with a solid content of 60%), triazine-containing phenol novolak-based curing Agent (Hydroxyl equivalent 146, DIC Corporation "LA-1356", MEK solution with a solid content of 60%) 6 parts, curing accelerator (4-dimethylaminopyridine (DMAP), MEK solution with a solid content of 2% by mass) 4 parts, flame retardant ("HCA-HQ" manufactured by Sanko Co., Ltd., 10-(2,5-dihydroxyphenyl)-10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide, average grain diameter 2 μm) 2 parts, spherical silica surface-treated with an aminosilane coupling agent (“KBM573” manufactured by Shin-Etsu Chemical Co., Ltd.) (average particle size 0.5 μm, “SOC2” manufactured by Admatechs Co., Ltd., unit area 120 parts of carbon content per unit area (0.39 mg/m ² ) were mixed and uniformly dispersed with a high-speed rotating mixer to prepare a resin varnish 1.
(2) Production of Resin Sheet 1 with Support As a support, a PET film (“AL5” manufactured by Lintec Corporation, thickness 38 μm) treated with an alkyd resin release agent was prepared. Resin varnish 1 was applied to the release surface of the support with a die coater and dried at 180° C. to 120° C. (average 100° C.) for 5 minutes to form resin composition layer 1 . The thickness of the resin composition layer 1 was 30 μm. Next, the smooth surface side of a polypropylene film (manufactured by Oji Specialty Paper Co., Ltd., "Alphan MA-411", thickness 15 μm) as a protective film is attached to the surface of the resin composition layer 1 that is not bonded to the support. Thus, a support-attached resin sheet 1 having a layer structure of protective film/resin composition layer 1/support was obtained.

[Production example 2]
(1) Preparation of resin varnish 2 Bisphenol-type epoxy resin (epoxy equivalent of about 165, "ZX1059" manufactured by Nippon Steel Chemical Co., Ltd., 1:1 mixture of bisphenol A type and bisphenol F type) 5 parts, bixylenol type Epoxy resin (epoxy equivalent about 185, Mitsubishi Chemical Co., Ltd. "YX4000HK") 10 parts, biphenyl type epoxy resin (epoxy equivalent about 290, Nippon Kayaku Co., Ltd. "NC3000H") 10 parts, and phenoxy resin (Mitsubishi 10 parts of "YL7553BH30" manufactured by Kagaku Co., Ltd. (MEK solution with a solid content of 30% by mass) was heated and dissolved in 30 parts of solvent naphtha with stirring. After cooling to room temperature, 20 parts of an active ester compound (active group equivalent of about 223, "HPC8000-65T" manufactured by DIC Corporation, a toluene solution of 65% by mass of non-volatile components), a naphthol-based curing agent (hydroxyl equivalent 215, "SN-485" manufactured by Nippon Steel Chemical Co., Ltd., MEK solution with a solid content of 60%) 12 parts, curing accelerator (4-dimethylaminopyridine (DMAP), MEK solution with a solid content of 2% by mass) 4 part, flame retardant ("HCA-HQ" manufactured by Sanko Co., Ltd., 10-(2,5-dihydroxyphenyl)-10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide, average particle size 2 μm) 2 parts, spherical silica (average particle size 0.5 μm, “SOC2” manufactured by Admatechs Co., Ltd., unit area 150 parts of carbon content per unit area (0.39 mg/m ² ) were mixed and uniformly dispersed with a high-speed rotating mixer to prepare a resin varnish 2.
(2) Preparation of support-attached resin sheet 2 Using the resin varnish 2 prepared in (1) above, in the same manner as in Preparation Example 1, a layer structure of protective film/resin composition layer 2/support is provided. A resin sheet 2 with a support was obtained.

Table 1 summarizes the compositions of the resin composition layers of the support-attached resin sheets 1 and 2.

<Example 1>
A printed wiring board was produced using the support-attached resin sheet 1 according to the procedure described above in [Preparation of sample for measurement and evaluation].
In Example 1, a dry desmear treatment was performed as the desmear treatment, and a conductor layer was formed by a dry method. Each evaluation result is shown in Table 2.

<Example 2>
Using the support-attached resin sheet 2, a printed wiring board was produced according to the above-mentioned [Preparation of sample for measurement and evaluation].
In Example 2, a wet desmear treatment was performed as the desmear treatment, and a conductor layer was formed by a wet method. Each evaluation result is shown in Table 2.

<Example 3>
Using the support-attached resin sheet 2, a printed wiring board was produced according to the above-mentioned [Preparation of sample for measurement and evaluation].
In Example 3, a dry desmear treatment was carried out as the desmear treatment, and a conductor layer was formed by a wet method. Each evaluation result is shown in Table 2.

<Comparative Example 1>
A printed wiring board was produced in the same manner as in Example 1, except that the order of (5) desmear treatment and (6) peeling of the support was changed in the above procedure [Preparation of sample for measurement and evaluation]. Each evaluation result is shown in Table 2.
In Comparative Example 1, the substrate after the dry desmear treatment was used as "evaluation substrate A".

<Comparative Example 2>
A printed wiring board was produced in the same manner as in Example 2, except that (5) desmear treatment was omitted in the procedure [Preparation of sample for measurement and evaluation]. Each evaluation result is shown in Table 2.

<Comparative Example 3>
A printed wiring board was manufactured in the same manner as in Example 2, except that the order of (5) desmear treatment and (6) peeling of the support was changed in the above procedure [Preparation of sample for measurement and evaluation]. Each evaluation result is shown in Table 2.

In Examples 1 to 3 in which the desmear treatment is performed with the support adhered to the insulating layer, it is possible to form an insulating layer with low roughness and high adhesive strength (peel strength) with the conductor layer, and also has excellent It was confirmed that the smear removal property was also exhibited. On the other hand, in Comparative Examples 1 and 3, although the surface roughness of the insulating layer was high, the adhesive strength (peel strength) between the insulating layer and the conductor layer was low. In addition, in Comparative Example 2, the smear on the bottom of the via hole could not be sufficiently removed.

Claims (11)

(A) a step of laminating a support-attached resin sheet containing a support and a resin composition layer bonded to the support onto an inner-layer circuit board such that the resin composition layer is bonded to the inner-layer circuit board;
(B) a step of thermosetting the resin composition layer of the support-attached resin sheet to form an insulating layer;
(C) a step of drilling the insulating layer to form a via hole;
(D) a step of performing desmear treatment;
(E) peeling off the support; and (F) forming, on the surface of the insulating layer, a conductor layer having a peel strength of 0.4 kgf/cm or more to the insulating layer, in this order;
In step (B), the resin composition layer is preheated at a constant temperature of 50° C. or more and less than 120° C. for 5 minutes to 150 minutes, and then heated at a constant temperature of 120° C. to 240° C. for 5 minutes to 90 minutes. A method of manufacturing a printed wiring board, comprising heating. 2. The method for producing a printed wiring board according to claim 1, wherein the desmear treatment in step (D) is wet desmear treatment, dry desmear treatment, or a combination thereof. Step (F) is
3. The method of manufacturing a printed wiring board according to claim 1, comprising roughening the surface of the insulating layer, and forming the conductive layer by wet plating the surface of the insulating layer, in this order. Step (F) is
3. The printed wiring board according to claim 1 or 2, comprising, in this order, forming a metal layer by dry plating on the surface of the insulating layer; and forming a conductor layer by wet plating on the surface of the metal layer. Production method. The method for producing a printed wiring board according to any one of claims 1 to 4, wherein the resin composition layer of the support-attached resin sheet contains an epoxy resin, a curing agent and an inorganic filler. 6. The method for producing a printed wiring board according to claim 5, wherein the curing agent contains an active ester curing agent. 7. The method for producing a printed wiring board according to claim 5, wherein the inorganic filler has an average particle size of 0.01 μm to 3 μm. The content of the inorganic filler in the resin composition layer is 40% by mass to 95% by mass when the non-volatile component of the resin composition layer is 100% by mass, according to any one of claims 5 to 7 A method for manufacturing the printed wiring board described. The method for producing a printed wiring board according to any one of claims 5 to 8, wherein the inorganic filler is surface-treated with a surface treatment agent. The print according to any one of claims 5 to 9, wherein the content of the inorganic filler in the resin composition layer is 72% by mass or more when the non-volatile component of the resin composition layer is 100% by mass. A method for manufacturing a wiring board. A method for manufacturing a semiconductor device using a printed wiring board manufactured by the method according to any one of claims 1 to 10.