JP2014170796A - Method for manufacturing multilayer printed wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a multilayer printed wiring board capable of preventing the occurrence of interfacial peeling (delamination) between a wiring and an insulation layer below the wiring.SOLUTION: A method for manufacturing a multilayer printed wiring board includes the following steps (A)-(E) which are sequentially performed. (A): a step of forming an insulation layer having an arithmetic average surface roughness (Ra) of 150 nm or less and a metal film layer laminated on the insulation layer, (B): a step of forming a wiring precursor on the metal film layer, (C): a step of performing heat treatment, (D): a step of removing the metal film layer at a part other than a part immediately below the wiring precursor by means of flash etching to form a wiring, and (E): a step of subjecting the wiring to surface treatment.

Description

  The present invention relates to a method for manufacturing a multilayer printed wiring board capable of preventing separation (delamination) of an interface between a wiring and an underlying insulating layer.

  Multilayer printed wiring boards widely used in various electronic devices are required to have thinner layers and finer wiring in order to reduce the size and increase the functionality of electronic devices. As a general method for producing a multilayer printed wiring board, (1) a step of forming an insulating layer and a metal film layer laminated on the insulating layer, (2) a wiring precursor on the metal film layer (that is, A step of forming a conductor pattern to be a surface layer of the wiring; (3) a step of forming a wiring by removing the metal film layer (metal film layer other than the portion immediately below the wiring precursor) by flash etching; and (4) annealing. A method of sequentially performing a processing step and (5) a surface treatment step of wiring is exemplified. The series of steps (1) to (5) are repeated according to the number of layers of the target wiring, and the wirings sandwiching the insulating layer are electrically connected by forming blind vias. In addition, the surface treatment process (step (5)) of the wiring described above is, for example, a process for roughening the surface of the wiring in order to improve the adhesion reliability between the wiring and the insulating layer laminated on the wiring. This is a process of providing a functional layer on the wiring surface for improving the adhesion with the insulating layer.

  By the way, conventionally, in order to increase the adhesion strength with the wiring, the surface of the insulating layer underlying the wiring (the insulating layer formed in the above step (1)) is roughened with an oxidizing agent to make the surface uneven. Has been made to form. However, when the surface of the insulating layer is roughened, the metal film layer is removed in the wiring formation step (that is, the step of removing the metal film layer other than the portion immediately below the wiring precursor by the flash etching in (3) above). When etching is performed under conditions that allow the metal film layer to be sufficiently removed, the dissolution of the wiring becomes noticeable, making it difficult to maintain the reliability of the wiring and hindering the formation of fine wiring. For this reason, recently, the roughening treatment on the surface of the insulating layer has been in the direction of lowering the roughness. In addition, the surface of the insulating layer is roughened by using an adhesive film with a metal film in which a resin layer for an insulating layer (generally a curable resin composition layer) and a metal film layer for wiring are integrally formed. The adhesion strength between the insulating layer and the wiring is also ensured without performing (for example, Patent Document 1).

International Publication No. 2008/1055481

  However, the inventors of the present application, in the manufacturing method in which the steps (1) to (5) are sequentially performed in accordance with the low roughness of the surface of the insulating layer serving as a base of the wiring, the wiring and the insulating layer below the wiring It has been found that the phenomenon of delamination of the interface may occur, and countermeasures for such a problem are necessary.

  The present invention has been made in view of the above circumstances, and a problem to be solved is a method for manufacturing a multilayer printed wiring board that can prevent interface delamination between a wiring and an insulating layer under the wiring. Is to provide.

  As a result of diligent research to solve the above-mentioned problems, the present inventors have conducted a annealing process after the metal film layer removal step by flash etching. Since the state of thermal expansion differs between the part directly below the part, a step is formed at the boundary between the part immediately below the wiring in the insulating layer and the part directly below the space part between the wiring, and the surface treatment of the wiring is performed on this step part. It was found that the treatment liquid at this time accumulated intensively and permeated the interface between the wiring and the insulating layer, which caused the interface separation (delamination) between the wiring and the insulating layer. In addition, when the surface roughness of the insulating layer is relatively large, the treatment liquid during the surface treatment of the wiring is difficult to enter the interface between the wiring and the insulating layer. There is no problem. Therefore, as a result of further research based on such knowledge, the present inventors annealed in a state where the metal film layer is laminated on the insulating layer before the metal film layer removal step by flash etching for wiring formation. It has been found that if the treatment is performed, the state of expansion / contraction of the insulating layer by the annealing treatment becomes uniform, and the formation of the above steps in the insulating layer can be prevented, and the present invention has been completed. That is, the present invention is as follows.

[1] A method for producing a multilayer printed wiring board, comprising sequentially performing the following steps (A) to (E).
(A): Step of forming an insulating layer having a surface arithmetic average roughness (Ra) of 150 nm or less and a metal film layer laminated on the insulating layer (B): forming a wiring precursor on the metal film layer Step (C): Step of performing heat treatment (D): Step of forming a wiring by removing the metal film layer other than the portion immediately below the wiring precursor by flash etching (E): Surface processing step of wiring [2] ( A) The process is
(I) a step of forming a metal film layer by electroless plating after forming an insulating layer and roughening the surface of the insulating layer;
(Ii) a step of forming an insulating layer and a metal film layer laminated on the insulating layer with an adhesive film with a metal film, or
(Iii) a step of forming an insulating layer and a metal film layer laminated on the insulating layer with an adhesive film with a metal film, removing the metal film layer, and then forming the metal film layer by electroless plating The method according to [1] above.
[3] The method according to [1] or [2] above, wherein the step (E) is a treatment for forming a wiring surface into a rough surface by wet etching.
[4] The method according to any one of [1] to [3], wherein the heat treatment temperature in step (C) is 180 ° C. or higher.
[5] Step (B)
(i) a step of laminating a dry film on the metal film layer, exposing and developing,
(ii) a process of performing electroplating; and
(iii) The method according to any one of the above [1] to [4], comprising a step of removing the dry film.
[6] Any of [1] to [5] above, wherein the metal film layer formed in the step (A) is a copper film layer, and the wiring precursor formed in the step (B) is a wiring precursor made of copper. The method according to one.
[7] The flash etching in the step (D) is performed by spraying a hydrogen peroxide-based etching solution at 25 to 50 ° C. for 10 to 120 seconds. The method described.
[8] The method according to any one of [1] to [7], wherein the insulating layer comprises a cured product of a resin composition including an epoxy resin, an epoxy curing agent, and an inorganic filler.
[9] A multilayer printed wiring board produced by the method according to any one of [1] to [8].
[10] A semiconductor device including the multilayer printed wiring board according to [9].

  According to the method for producing a multilayer printed wiring board of the present invention, it is possible to prevent peeling (delamination) of the interface between the wiring and the underlying insulating layer, and thus it is possible to produce a highly reliable multilayer printed wiring board. In addition, there is no separation of the interface between the wiring and the underlying insulating layer (lower layer), and a highly reliable multilayer printed wiring board with high adhesion reliability between the wiring and the insulating layer (upper layer) covering the wiring is manufactured. can do.

Hereinafter, the present invention will be described with reference to preferred embodiments thereof.
The manufacturing method of the multilayer printed wiring board of the present invention is mainly characterized in that the following steps (A) to (E) are sequentially performed.
(A): Step of forming an insulating layer having a surface arithmetic average roughness (Ra) of 150 nm or less and a metal film layer laminated on the insulating layer (B): Forming a wiring precursor on the metal film layer Step (C): Step of performing heat treatment (D): Step of forming a wiring by removing the metal film layer other than the portion immediately below the wiring precursor by flash etching (E): Surface processing step of the wiring

[Step (A)]
The step (A) in the present invention is a step of forming an insulating layer having a surface arithmetic average roughness (Ra) of 150 nm or less and a metal film layer laminated on the insulating layer. The insulating layer may be an insulating layer as a core material or an insulating layer as a build-up material. In the case of an insulating layer as a build-up material, an insulating layer is formed on the inner layer circuit board. As used herein, “inner circuit board” refers to the formation of wiring (circuits) on one or both sides of a glass epoxy board, metal board, polyester board, polyimide board, BT resin board, thermosetting polyphenylene ether board or the like. This means an intermediate product in which insulating layers and wirings are to be further formed when a multilayer printed wiring board is manufactured by alternately laminating insulating layers and wirings on the wiring boards. Therefore, on the “inner layer circuit board”, the wiring (circuit) formed on the insulating layer and the surface of the insulating layer after the steps (A) to (E) of the present invention have already been sequentially performed on the wiring board. ) Are also included.

{Insulation layer}
The insulating layer can be formed by thermosetting the curable resin composition. The thermosetting conditions may be appropriately selected according to the type and content of the resin component in the resin composition, but preferably 150 ° C. to 220 ° C. for 20 minutes to 180 minutes, more preferably 160 ° C. to 210 ° C. It is selected in the range of 30 minutes to 120 minutes at ° C. In addition, from the viewpoint of preventing wrinkles on the surface of the insulating layer, it is preferable to cure in steps from a relatively low curing temperature to a high curing temperature, for example, 150 ° C. after preliminary heat curing at 80 ° C. to 130 ° C. for 10 to 60 minutes. It is preferable to perform thermosetting at ˜220 ° C. for 20 minutes to 180 minutes. Further, curing may be performed while increasing from a relatively low curing temperature to a high curing temperature.

  The curable resin composition used for forming the insulating layer is not particularly limited as long as the cured product has sufficient hardness and insulating properties. For example, the composition contains an epoxy resin as the curable resin. A product containing (a) an epoxy resin, (b) an epoxy curing agent, and (c) an inorganic filler is more preferable.

(A) Examples of the epoxy resin include bisphenol A type epoxy resin, biphenyl type epoxy resin, naphthol type epoxy resin, naphthalene type epoxy resin, bisphenol F type epoxy resin, phosphorus-containing epoxy resin, bisphenol S type epoxy resin, and alicyclic ring Epoxy resin, aliphatic chain epoxy resin, phenol novolac epoxy resin, cresol novolac epoxy resin, bisphenol A novolac epoxy resin, epoxy resin having butadiene structure, diglycidyl etherified product of bisphenol, diglycidyl ether of naphthalenediol , Glycidyl etherified products of phenols, and diglycidyl etherified products of alcohols, and alkyl-substituted products, halides and hydrogenated products of these epoxy resins And the like. These epoxy resins may be used alone or in combination of two or more.

  Epoxy resins are bisphenol A-type epoxy resins, naphthol-type epoxy resins, naphthalene-type epoxy resins, biphenyl-type epoxy resins, and epoxy resins having a butadiene structure, especially from the viewpoints of heat resistance, insulation reliability, and adhesion to metal films. Is preferred. Specifically, for example, liquid bisphenol A type epoxy resin (“jER828EL” manufactured by Japan Epoxy Resin Co., Ltd.), naphthalene type bifunctional epoxy resin (“HP4032”, “HP4032D” manufactured by DIC Corporation), naphthalene type 4 Functional epoxy resin (“HP4700” manufactured by DIC Corporation), naphthol type epoxy resin (“ESN-475V” manufactured by Toto Kasei Co., Ltd.), anthraquinone type epoxy resin (“YX8800” manufactured by Japan Epoxy Resin Co., Ltd.), butadiene Epoxy resin having a structure ("PB-3600" manufactured by Daicel Corporation), epoxy resin having a biphenyl structure ("NC3000H", "NC3000L" manufactured by Nippon Kayaku Co., Ltd.), "YX4000" manufactured by Japan Epoxy Resin Co., Ltd. ) And the like.

  The content of the epoxy resin is preferably 1 to 40% by mass, more preferably 5 to 35% by mass, and still more preferably 10 to 30% by mass, when the nonvolatile component in the curable resin composition is 100% by mass.

Examples of (b) epoxy curing agents include phenolic curing agents, active ester curing agents, benzoxazine curing agents, cyanate ester curing agents, and the like. These can use 1 type (s) or 2 or more types. Among these, a phenol type curing agent and an active ester type curing agent are preferable from the viewpoints of improving heat resistance and improving adhesion to a metal film.

  Although it does not restrict | limit especially as a phenol type hardening | curing agent, A biphenyl type hardening | curing agent, a naphthalene type hardening | curing agent, a phenol novolak type hardening | curing agent, a naphthylene ether type hardening | curing agent, and a triazine skeleton containing phenol type hardening | curing agent are preferable. Specifically, biphenyl type curing agents MEH-7700, MEH-7810, MEH-7785 (Maywa Kasei Co., Ltd.), naphthalene type curing agents NHN, CBN, GPH (Nippon Kayaku Co., Ltd.), SN170, SN180, SN190, SN475, SN485, SN495, SN375, SN395 (manufactured by Tohto Kasei Co., Ltd.), EXB9500 (manufactured by DIC Corporation), phenol novolac type curing agent TD2090 (manufactured by DIC Corporation), naphthylene Examples include ether type curing agents EXB-6000 (manufactured by DIC Corporation). Specific examples of the triazine skeleton-containing phenolic curing agent include LA3018, LA7052, LA7054, LA1356 (manufactured by DIC Corporation) and the like. In particular, a triazine skeleton-containing phenol-based curing agent is preferable in terms of improving adhesion to a metal film.

  The active ester type curing agent functions as a curing agent for epoxy resins, and generally has an ester group having a high reaction activity such as phenol esters, thiophenol esters, N-hydroxyamine esters, and esters of heterocyclic hydroxy compounds. A compound having two or more molecules in the molecule is preferably used. The active ester curing agent is preferably obtained by a condensation reaction of 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 heat resistance and the like, an active ester curing agent obtained from a carboxylic acid compound and a phenol compound or a naphthol compound is preferable. Examples of the carboxylic acid compound include benzoic acid, acetic acid, succinic acid, maleic acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, and pyromellitic acid. Examples of the phenol compound or naphthol compound include hydroquinone, resorcin, bisphenol A, bisphenol F, bisphenol S, phenolphthaline, methylated bisphenol A, methylated bisphenol F, methylated bisphenol S, phenol, o-cresol, m-cresol, p-cresol, catechol, α-naphthol, β-naphthol, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, phloroglucin, benzenetriol , Dicyclopentadienyl diphenol, phenol novolac and the like.

  As the active ester curing agent, specifically, an active ester curing agent having a dicyclopentadienyl diphenol structure, an active ester curing agent having a naphthalene structure, an active ester curing agent which is an acetylated product of phenol novolac, Active ester hardeners, which are benzoylated phenol novolacs, are preferred, especially active ester-based compounds containing dicyclopentadienyl diphenol structure in that they act more effectively by improving the peel strength against the insulating layer of the wiring A curing agent is more preferable. As the active ester curing agent, an active ester curing agent disclosed in JP-A-2004-277460 may be used, or a commercially available one may be used. Commercially available products containing dicyclopentadienyl diphenol structure EXB9451, EXB9460, EXB9460S-65T, HPC8000-65T (manufactured by DIC Corporation, active group equivalent of about 223), an active ester which is an acetylated product of phenol novolak DC808 (manufactured by Mitsubishi Chemical Corporation, active group equivalent of about 149) as a system hardener, YLH1026 (manufactured by Mitsubishi Chemical Corporation, active group equivalent of about 200), YLH1030 as an active ester type hardener that is a benzoylated phenol novolak (Mitsubishi Chemical Corporation, active group equivalent of about 201), YLH1048 (Mitsubishi Chemical Corporation, active group equivalent of about 245) and the like.

  Specific examples of the benzoxazine compound include Fa, Pd (both manufactured by Shikoku Kasei Kogyo Co., Ltd.), HFB2006M (manufactured by Showa Polymer Co., Ltd.), and the like.

The blending ratio of (a) epoxy resin and (b) epoxy curing agent is preferably such that when the number of epoxy groups of the epoxy resin is 1, the number of reactive groups of the epoxy curing agent is in the range of 0.4 to 2.0. A ratio in the range of 0.5 to 1.0 is more preferable. The number of epoxy groups of the epoxy resin present in the curable resin composition is a value obtained by dividing the solid content mass of each epoxy resin by the epoxy equivalent for all epoxy resins, and the number of reactive groups of the epoxy curing agent. Is a value obtained by adding the values obtained by dividing the solid mass of each curing agent by the reactive group equivalent for all curing agents. When the ratio of the reactive groups is within this range, the mechanical strength and water resistance of the cured product tend to be improved.

Examples of the inorganic filler (c) include silica, alumina, mica, mica, silicate, barium sulfate, magnesium hydroxide, titanium oxide, and the like. Silica and alumina are preferable, and amorphous silica, fused silica, Silica such as crystalline silica and synthetic silica is preferred. In particular, fused silica and spherical silica are more preferred, and spherical fused silica is more preferred in terms of enhancing the filling property into the curable resin composition. You may use these 1 type or in combination of 2 or more types. Examples of commercially available spherical fused silica include “SOC2” and “SOC1” manufactured by Admatechs Co., Ltd.

  The average particle diameter of the inorganic filler is not particularly limited, but the average particle diameter is preferably 0.01 to 3 μm, more preferably 0.05 to 1.5 μm, and 0.1 to 0.8 μm. More preferably. The average particle diameter of the inorganic filler can be measured by a laser diffraction / scattering method based on Mie scattering theory. Specifically, the particle size distribution of the inorganic filler can be prepared on a volume basis by a laser diffraction / scattering particle size distribution measuring apparatus, and the median diameter can be measured as the average particle diameter. As the measurement sample, an inorganic filler dispersed in water by ultrasonic waves can be preferably used. As a laser diffraction scattering type particle size distribution measuring apparatus, LA-500 manufactured by Horiba Ltd. can be used.

  The content of the inorganic filler is preferably 30 to 90% by mass, more preferably 40 to 85% by mass, and still more preferably 50 to 80% when the nonvolatile component in the curable resin composition is 100% by mass. % By mass. When the content of the inorganic filler is less than 30% by mass, the effect of lowering the thermal expansion coefficient tends not to be sufficiently exhibited. When the content of the inorganic filler exceeds 90% by mass, the mechanical strength of the cured product is decreased. It tends to be easy.

  Inorganic fillers include aminopropylmethoxysilane, aminopropyltriethoxysilane, ureidopropyltriethoxysilane, N-phenylaminopropyltrimethoxysilane, and N-2 (aminoethyl) amino to improve moisture resistance, dispersibility, and the like. Aminosilane coupling agents such as provirtrimethoxysilane, glycidoxypropyltrimethoxysilane, glycidoxypropyltriethoxysilane, glycidoxypropylmethyldiethoxysilane, glycidylbutyltrimethoxysilane, (3,4-epoxy (Cyclohexyl) Epoxysilane coupling agents such as ethyltrimethoxysilane, mercaptosilane coupling agents such as mercatopropyltrimethoxysilane and mercatopropyltriethoxysilane, methyltrimethoxysilane, Silane coupling agents such as tadecyltrimethoxysilane, phenyltrimethoxysilane, methacroxypropyltrimethoxysilane, imidazolesilane, triazinesilane, hexamethyldisilazane, hexaphenyldisilazane, dimethylaminotrimethylsilane, trisilazane, cyclotri Organosilazane compounds such as silazane, 1,1,3,3,5,5-hexamethylcyclotrisilazane, butyl titanate dimer, titanium octylene glycolate, diisopropoxy titanium bis (triethanolaminate), dihydroxy titanium bis lactate, Dihydroxybis (ammonium lactate) titanium, bis (dioctylpyrophosphate) ethylene titanate, bis (dioctylpyrophosphate) oxyacetate Titanate, tri-n-butoxy titanium monostearate, tetra-n-butyl titanate, tetra (2-ethylhexyl) titanate, tetraisopropyl bis (dioctyl phosphite) titanate, tetraoctyl bis (ditridecyl phosphite) titanate, tetra ( 2,2-diallyloxymethyl-1-butyl) bis (ditridecyl) phosphite titanate, isopropyltrioctanoyl titanate, isopropyltricumylphenyl titanate, isopropyltriisostearoyl titanate, isopropylisostearoyl diacryl titanate, isopropyldimethacrylisostearoyl Titanate, isopropyltri (dioctylphosphate) titanate, isopropyltridodecylbenzenesulfonyl titanate Over DOO, isopropyl tris (dioctyl pyrophosphate) titanate, may be treated with one kind or more surface treating agents such as isopropyl tri (N- amidoethyl-aminoethyl) titanate titanate coupling agent.

  The curable resin composition may further contain (d) a polymer resin for the purpose of imparting appropriate flexibility to the cured composition. The polymer resin is not particularly limited, but phenoxy resin, polyvinyl acetal resin, polyimide resin, polyamideimide resin, polyetherimide resin, polysulfone resin, polyethersulfone resin, polyphenylene ether resin, polycarbonate resin, polyetheretherketone resin. And polyester resins, and phenoxy resins and polyvinyl acetal resins are particularly preferable. These polymer resins may be used alone or in combination of two or more. The weight average molecular weight of the polymer resin is preferably in the range of 8,000 to 200,000, and more preferably in the range of 12,000 to 100,000. In addition, the weight average molecular weight in this invention is measured by the gel permeation chromatography (GPC) method (polystyrene conversion). Specifically, the weight average molecular weight by the GPC method is LC-9A / RID-6A manufactured by Shimadzu Corporation as a measuring device, and Shodex K-800P / K-804L / K- manufactured by Showa Denko KK as a column. 804 L 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. When mix | blending polymer resin, when the non-volatile component in curable resin composition is 100 mass%, 0.1-10 mass% is preferable and 0.5-5 mass% is more preferable. Within this range, the effect of improving the film forming ability and mechanical strength can be exhibited, and the melt viscosity can be increased and the roughness of the insulating layer surface after the wet roughening step can be reduced.

  The curable resin composition may further contain (e) a curing accelerator for the purpose of efficiently reacting the epoxy resin and the epoxy curing agent. Although it does not specifically limit as a hardening accelerator, An amine hardening accelerator, a guanidine hardening accelerator, an imidazole hardening accelerator, a phosphonium hardening accelerator, a metal hardening accelerator, etc. are mentioned. These may be used alone or in combination of two or more. The amine curing accelerator is not particularly limited, but is trialkylamine, 4-dimethylaminopyridine, benzyldimethylamine, 2,4,6, -tris (dimethylaminomethyl) phenol, 1,8- And diazabicyclo (5,4,0) -undecene (hereinafter abbreviated as DBU). Although it does not specifically limit as a guanidine type hardening accelerator, Dicyandiamide, 1-methylguanidine, etc. are mentioned. The imidazole curing accelerator is not particularly limited, but 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, Examples include 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, and adducts of an imidazole compound and an epoxy resin. Although it does not specifically limit as a phosphonium type hardening accelerator, A triphenyl phosphine, a phosphonium borate compound, tetraphenyl phosphonium tetraphenyl borate, etc. are mentioned. You may use these 1 type or in combination of 2 or more types. When using a hardening accelerator, it is preferable to use in 0.05-2 mass parts with respect to 100 mass parts of epoxy resins.

  The curable resin composition may further contain (f) a flame retardant for the purpose of imparting flame retardancy. Examples of the flame retardant include an organic phosphorus flame retardant, an organic nitrogen-containing phosphorus compound, a nitrogen compound, a silicone flame retardant, and a metal hydroxide. Examples of organic phosphorus flame retardants 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 Polymer Co., Ltd., and Ajinomoto Reefos 30, 50, 65, 90, 110, Fine Techno Co., TPP, RPD, BAPP, CPD, TCP, TXP, TBP, TOP, KP140, TIBP, TPPO, PPQ, manufactured by Hokuko Chemical Co., Ltd. Phosphoric ester compounds such as OP930 manufactured by Clariant Co., Ltd., PX200 manufactured by Daihachi Chemical Co., Ltd., phosphorus-containing epoxy resins such as FX289, FX305 and TX0712 manufactured by Nippon Steel Chemical Co., Ltd., Nippon Steel Chemical Co., Ltd. Phosphorus-containing phenoxy resins such as ERF001 manufactured by Co., Ltd., phosphorus-containing epoxy resins such as YL7613 manufactured by Mitsubishi Chemical Corporation, etc. And the like. Examples of organic nitrogen-containing phosphorus compounds include phosphate ester amide compounds such as SP670 and SP703 manufactured by Shikoku Kasei Kogyo Co., Ltd., SPB100 and SPE100 manufactured by Otsuka Chemical Co., Ltd., and FP-series manufactured by Fushimi Pharmaceutical Co., Ltd. And phosphazene compounds. As the metal hydroxide, magnesium hydroxide such as UD65, UD650, UD653 manufactured by Ube Materials Co., Ltd., B-30, B-325, B-315, B-308, B manufactured by Sakai Kogyo Co., Ltd. And aluminum hydroxide such as -303 and UFH-20. When mix | blending a flame retardant, it becomes like this. Preferably it is 0.5-10 mass% with respect to 100 mass% of non-volatile components in curable resin composition, More preferably, it is 1-5 mass%.

  In the curable resin composition, other components can be blended as necessary within a range not inhibiting the effects of the present invention. Other components include vinyl benzyl compounds, acrylic compounds, maleimide compounds, thermosetting resins such as blocked isocyanate compounds, organic fillers such as silicon powder, nylon powder and fluororesin powder, thickeners such as Orben and Benton. , Silicone-based, fluorine-based, polymer-based antifoaming agent or leveling agent, imidazole-based, thiazole-based, triazole-based, adhesion-imparting agent such as silane coupling agent, phthalocyanine blue, phthalocyanine green, iodin green, Examples thereof include colorants such as disazo yellow and carbon black. The curable resin composition is appropriately mixed with the above components and, if necessary, kneaded or mixed by a kneading means such as a three roll, ball mill, bead mill, or sand mill, or a stirring means such as a super mixer or a planetary mixer. Can be adjusted. Moreover, it can adjust also as a resin varnish by adding an organic solvent. Examples of the organic solvent include ketones such as acetone, methyl ethyl ketone and cyclohexanone, acetates such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate and carbitol acetate, and carbitols such as cellosolve and butyl carbitol. , Aromatic hydrocarbons such as toluene and xylene, dimethylformamide, dimethylacetamide, N-methylpyrrolidone and the like. Two or more organic solvents may be used in combination.

{Insulation layer and formation of metal film on the insulation layer}
Regarding the method of forming the insulating layer and the metal film layer in the step (A), a specific mode of forming the insulating layer on the inner layer circuit board will be described in detail. Specific examples of the step (A) include the following (i) to (iii).
(I) A step of forming a metal film layer by electroless plating after forming an insulating layer and roughening the surface of the insulating layer.
(Ii) A step of forming an insulating layer and a metal film layer laminated on the insulating layer with an adhesive film with a metal film.
(Iii) A step of forming an insulating layer and a metal film layer laminated on the insulating layer with an adhesive film with a metal film, removing the metal film layer, and then forming a metal film layer by electroless plating.

When the step (A) is carried out in the mode (i), a curable resin composition layer is formed by coating a resin varnish on the inner circuit board and drying, or a die coater or the like is formed on the support. The adhesive film on which the curable resin composition layer is formed is formed by applying and drying the resin varnish, and laminating the adhesive film on the inner circuit board to form the curable resin composition layer as the inner layer. By laminating the circuit board, a curable resin composition layer is formed on the inner circuit board. The drying conditions of the resin varnish are not particularly limited, but the resin varnish is dried so that the content of the organic solvent in the curable resin composition layer is 10% by mass or less, preferably 5% by mass or less. Depending on the amount of organic solvent in the varnish and the boiling point of the organic solvent, for example, by drying a varnish containing 30 to 60% by mass of the organic solvent at 50 to 150 ° C. for about 3 to 10 minutes, the curable resin composition layer Can be formed.

When an adhesive film is used, it is laminated (laminated) on one or both sides of the inner circuit board using a vacuum laminator. A method of laminating on the inner circuit board under reduced pressure by a vacuum laminating method is preferably used. Lamination conditions are not particularly limited. For example, the pressure bonding temperature (laminating temperature) is preferably 70 to 140 ° C., and the pressure bonding pressure (laminating pressure) is preferably 1 to 11 kgf / cm ² (9.8 × 10 ^{4 to} 107.9 × 10 ⁴ N / m ² ), the pressure bonding time (laminating time) is preferably 5 to 180 seconds, and the lamination is preferably performed under reduced pressure with an air pressure of 20 mmHg (26.7 hPa) or less. The laminating method may be a batch method or a continuous method using a roll. The vacuum lamination can be performed using a commercially available vacuum laminator. Commercially available vacuum laminators include, for example, a vacuum applicator manufactured by Nichigo-Morton Co., Ltd., a vacuum pressurizing laminator manufactured by Meiki Seisakusho Co., Ltd., a roll dry coater manufactured by Hitachi Industries, Ltd., and Hitachi AIC Co., Ltd. ) Made vacuum laminator and the like.

  Next, when peeling a support body, it peels and this curable resin composition layer is thermosetted, and an insulating layer is formed on an inner-layer circuit board. The thermosetting conditions are as described above. After forming the insulating layer, if the support is not peeled off before curing, the support can be peeled off if necessary.

  The removal of the support is generally performed by peeling the support, and the peeling is performed manually or by mechanical peeling with an automatic peeling device. Moreover, when metal foil is used for a support body, a support body can also be removed by an etching.

  Next, a hole is formed in the insulating layer formed on the circuit board to form a via hole, or a via hole and a through hole can be formed. For example, the drilling can be performed by a known method such as drilling, laser, or plasma, and can be performed by combining these methods as necessary. However, drilling by a laser such as a carbon dioxide laser or a YAG laser can be performed. Is the most common method. In addition, when a support body is not peeled before drilling, it will peel here.

  Next, the surface of the insulating layer is roughened. Examples of the roughening treatment include a plasma treatment in the case of a dry roughening treatment. In the case of a wet roughening treatment, a swelling treatment with a swelling liquid, a roughening treatment with an oxidizing agent, and a neutralization treatment with a neutralizing solution are performed. The method of performing in order is mentioned. The wet roughening treatment is preferable in terms of high productivity because a large capacity and a plurality of substrates can be processed. The swelling treatment with the swelling liquid is performed by immersing the insulating layer in the swelling liquid at 50 to 80 ° C. for 5 to 20 minutes (preferably at 55 to 70 ° C. for 8 to 15 minutes). Examples of the swelling liquid include an alkaline solution and a surfactant solution, and an alkaline solution is preferable. Examples of the alkaline solution include a sodium hydroxide solution and a potassium hydroxide solution. Examples of commercially available swelling liquids include Swelling Dip Securiganth P (Swelling Dip Securiganth S) and Swelling Dip Securiganth SBU (ABUTEC Japan). be able to. The roughening treatment with an oxidizing agent is performed by immersing the insulating layer in an oxidizing agent solution at 60 to 80 ° C. for 10 to 30 minutes (preferably at 70 to 80 ° C. for 15 to 25 minutes). Examples of the oxidizing agent include alkaline permanganate solution in which potassium permanganate and sodium permanganate are dissolved in an aqueous solution of sodium hydroxide, dichromate, ozone, hydrogen peroxide / sulfuric acid, nitric acid and the like. it can. Moreover, it is preferable that the density | concentration of the permanganate in an alkaline permanganic acid solution shall be 5-10 mass%. Examples of commercially available oxidizing agents include alkaline permanganic acid solutions such as Concentrate Compact CP and Dosing Solution Securigans P manufactured by Atotech Japan. The neutralization treatment with the neutralizing solution is performed by immersing in a neutralizing solution at 30 to 50 ° C. for 3 to 10 minutes (preferably at 35 to 45 ° C. for 3 to 8 minutes). As the neutralizing solution, an acidic aqueous solution is preferable, and as a commercially available product, Reduction Solution / Secligant P manufactured by Atotech Japan Co., Ltd. may be mentioned.

  In the roughening treatment, the arithmetic average roughness (Ra) of the surface of the insulating layer after the roughening treatment is 150 nm or less (preferably 100 nm or less, more preferably 70 nm or less) in order to form highly reliable fine wiring. Do as follows. In addition, from the viewpoint of ensuring a sufficiently high adhesion strength between the insulating layer surface and the wiring, the arithmetic average roughness (Ra) is preferably 1 nm or more, and more preferably 5 nm or more.

  Next, a metal film layer is formed by electroless plating on the surface of the insulating layer that has been roughened. The electroless plating can be performed by a known method. For example, the surface of the insulating layer is treated with a surfactant or the like, a plating catalyst such as palladium is applied, and the metal film layer is impregnated with an electroless plating solution. Can be formed. Examples of the metal film layer include copper, nickel, gold, palladium and the like, but copper is preferable. The thickness of the metal film layer is preferably 0.1 to 5.0 μm, more preferably 0.2 to 2.5 μm, and more preferably 0.2 to 1.5 μm, from the viewpoint of sufficient covering of the insulating layer surface and cost. Is more preferable. The metal film layer may be formed by a direct plating method that is a kind of electroless plating.

When the step (A) is carried out in the mode (ii), an adhesive film with a metal film in which a metal film layer and a curable resin composition layer are laminated in this order on a support is prepared. The curable resin composition layer is laminated on the inner circuit board with the inner circuit board side facing, and the curable resin composition layer is thermally cured to form an insulating layer, and then the support is peeled from the metal film layer. Then, an insulating layer and a metal film layer stacked on the insulating layer are formed.
When the step (A) is carried out in the mode (iii), an insulating layer and a metal film layer laminated on the insulating layer are formed in the same manner as the mode (ii). The metal film layer (metal film layer derived from the adhesive film with metal film) laminated on the layer is removed, and a new metal film layer is formed by electroless plating.

The adhesive film with a metal film used in the above aspects (ii) and (iii) is formed by forming a metal film layer on a support and forming a curable resin composition layer on the surface of the obtained metal film layer. Can be obtained. A release layer is preferably provided between the support and the metal film layer. When the release layer is provided, the release layer is formed on the surface of the support prior to the formation of the metal film layer. A metal film layer is formed on the layer surface. Moreover, the adhesive film with a metal film is a film with a metal film in which a metal film layer is formed on a support, and an adhesive film in which a curable resin composition layer is formed on a support. The adhesive film can also be produced by a method in which the metal film layer and the curable resin composition layer are bonded together under heating conditions. The film with the metal film and the adhesive film are bonded to each other so that the metal film layer of the film with the metal film and the curable resin composition layer of the adhesive film face each other, and heated with a hot press, a heat roll, or the like. Crimp. The crimping temperature is preferably 60 to 140 ° C, more preferably 80 to 120 ° C. The crimping pressure is preferably in the range of 1 to 11 kgf / cm ² (9.8 × 10 ^{4 to} 107.9 × 10 ⁴ N / m ² ), and ^{2 to} 7 kgf / cm ² (19.6 × 10 ^{4 to} 68.68. A range of 6 × 10 ⁴ N / m ² ) is particularly preferred. The pressure bonding time is preferably 10 to 120 seconds.

  Thereafter, the metal film-attached adhesive film is laminated to the inner circuit board, thermally cured, and peeled off from the support in the same manner as in the above-described embodiment (i). The support is peeled off after the insulating layer is formed by thermosetting the curable resin composition layer. If a release layer exists between the support and the metal film layer and the release layer remains on the metal film layer after the support is removed, the release layer is removed. In the case of forming the blind via, the removal of the support (if the release layer remains on the metal film layer, the removal of the support and the release layer) may be either before or after the step of forming the blind via. However, generally before the formation of blind vias is preferred. The release layer is removed, for example, with a metal release layer using an etching solution that dissolves the metal, and with a water-soluble polymer release layer using an aqueous solution.

  The arithmetic average roughness (Ra) of the insulating layer surface in the above aspects (ii) and (iii) is 150 nm or less (preferably 100 nm or less, more preferably 70 nm or less). In addition, from the viewpoint of ensuring a sufficiently high adhesion strength between the insulating layer surface and the wiring, the arithmetic average roughness (Ra) is preferably 1 nm or more, and more preferably 5 nm or more.

{Adhesive film with metal film, film with metal film and adhesive film}
(Support)
The adhesive film with a metal film, the film with the metal film, and the support in the adhesive film are self-supporting films or sheets, and metal foils, plastic films, etc. can be used, and plastic films are particularly preferably used. It is done. Examples of the metal foil include aluminum foil and copper foil. In the case of an adhesive film with a metal film, in which the support is a metal foil and does not have a release layer, a metal foil made of a metal different from the metal film layer is employed for the metal foil of the support. preferable. Examples of the plastic film include polyethylene terephthalate film, polyethylene naphthalate, polyimide, polyamideimide, polyamide, polytetrafluoroethylene, polycarbonate, and the like. Polyethylene terephthalate film and polyethylene naphthalate film are preferable, and inexpensive polyethylene terephthalate is particularly preferable. preferable. The surface of the support on which the metal film layer and the release layer are formed may be subjected to a surface treatment such as a corona treatment. Further, the surface of the support on which the metal film layer or the release layer is not formed may be subjected to surface treatment such as mat treatment or corona treatment. A commercially available support can also be used. For example, T60 (manufactured by Toray Industries, Inc., polyethylene terephthalate film), A4100 (manufactured by Toyobo Co., Ltd., polyethylene terephthalate film), Q83 (manufactured by Teijin DuPont Films, Inc.) Polyethylene naphthalate film), Diafoil B100 (manufactured by Mitsubishi Chemical Polyester Film Co., Ltd., polyethylene terephthalate film), alkyd mold release agent (AL-5, manufactured by Lintec Co., Ltd.) Examples thereof include a polyethylene terephthalate film with a film. The thickness of the support is preferably 10 to 100 μm, more preferably 15 to 75 μm.

(Release layer)
In the adhesive film with metal film and the film with metal film, when a release layer is provided between the support and the metal film layer, the release layer may be a fluororesin, an alkyd resin, a silicone resin, a polyolefin resin, or a polyvinyl alcohol resin. Polymer release layers such as acrylic resin, polyester resin, melamine resin and cellulose are used. Further, a metal release layer made of a metal film or metal foil formed by vapor deposition, sputtering, ion plating, or the like can be used. Examples of the metal constituting the metal film or the metal foil include aluminum, zinc, lead, nickel, and the like, among which aluminum is preferable.

  The release layer is one or more water-soluble substances selected from a water-soluble cellulose resin, a water-soluble acrylic resin, and a water-soluble polyester resin from the viewpoint of uniformly transferring the metal film layer and the cost of forming the release layer. It is preferable to form with a conductive polymer. These water-soluble polymer release layers are easier to form on the support than the metal release layer, and are advantageous in terms of cost. In addition, the support can be peeled off between the support and the release layer after the curable resin composition layer is cured, and the metal film layer is not easily damaged, and the release layer remaining on the metal film layer is easily removed with an aqueous solution. it can. For this reason, by using an adhesive film with a metal film using a water-soluble polymer release layer as the release layer, it is possible to transfer the metal film layer uniformly to the inner layer substrate. The water-soluble polymer is preferably water-soluble cellulose or water-soluble polyester, and more preferably water-soluble cellulose. Any water-soluble polymer is used alone in the water-soluble polymer release layer, but two or more water-soluble polymers may be mixed and used. In addition, the water-soluble polymer release layer is usually formed as a single layer, but it may have a multilayer structure formed of two or more different types of water-soluble polymers used. When a water-soluble polymer release layer is used as the release layer, silicone resin, alkyd resin, fluorine, and the like are used to improve the peelability between the water-soluble polymer release layer and the support. There may be another release layer made of resin or the like. That is, when a water-soluble polymer is applied to the release layer, it is sufficient that at least the surface of the release layer in contact with the metal film layer is formed of the water-soluble polymer. Either a mold layer alone or a two-layer structure of a water-soluble polymer release layer and another release layer so that the surface in contact with the metal film layer is formed of a water-soluble polymer it can.

  The layer thickness of the release layer is preferably 0.01 μm or more and 20 μm or less, more preferably 0.05 μm or more and 5 μm or less, and further preferably 0.1 μm or more and 2 μm or less. The “layer thickness” here is the thickness when the release layer is a single layer, and the total thickness of the multilayer when it is a multilayer. In the case of a multilayer, the thickness of the release layer other than the water-soluble polymer release layer is preferably in the range of 0.01 to 0.2 μm.

(Metal film layer)
Metals used for metal film layers in metal film adhesive films and metal film films include metals such as gold, platinum, silver, copper, aluminum, cobalt, chromium, nickel, titanium, tungsten, iron, tin, and indium. A solid solution (alloy) of two or more kinds of metals such as a simple substance or nickel / chromium alloy can be mentioned, and copper is particularly preferable from the viewpoint of versatility of metal film formation, cost, ease of removal by etching, and the like. Further, the metal film layer may be a single layer or a multilayer structure in which two or more different metals are laminated.

  The metal film layer is preferably a metal film layer formed by one or more methods selected from an evaporation method, a sputtering method, and an ion plating method. Particularly preferred are a metal film layer formed by an evaporation method, a metal film layer formed by a sputtering method, or a metal film layer formed by an evaporation method and a sputtering method. A metal foil can also be used as the metal film layer. The layer thickness of the metal film layer is preferably 25 nm to 5000 nm, more preferably 25 nm to 3000 nm, still more preferably 100 nm to 3000 nm, and particularly preferably 100 nm to 2000 nm.

(Curable resin composition layer)
The above-mentioned curable resin composition is used for the curable resin composition used for the curable resin composition layer. The curable resin composition layer may be a prepreg obtained by impregnating a curable resin composition in a sheet-like reinforcing base material. As the sheet-like reinforcing substrate, for example, a glass cloth, an aramid fiber, or the like that is commonly used as a prepreg fiber can be used. The prepreg can be formed by impregnating a curable resin composition into a sheet-like reinforcing base material by a hot melt method or a solvent method and semi-curing by heating. In the hot melt method, the resin composition is once coated on a support without being dissolved in an organic solvent, and then laminated on a sheet-like reinforcing substrate, or directly applied to a sheet-like reinforcing substrate by a die coater. It is a method of manufacturing a prepreg by, for example, processing. The solvent method is a method in which a resin varnish is prepared, a sheet-like reinforcing base material is immersed in the varnish, the resin varnish is impregnated into the sheet-like reinforcing base material, and then dried. Alternatively, the adhesive film can be prepared by continuously laminating the adhesive film from both sides of the sheet-like reinforcing substrate under heating and pressure conditions.

[Step (B)]
Step (B) in the present invention is a step of forming a wiring precursor on the metal film layer. In the present invention, the “wiring precursor” means a patterned conductor layer that finally becomes a surface layer of the wiring, and is usually formed of copper, nickel, gold, palladium, or the like. Preferably, after a mask having a desired pattern is formed on the metal film layer using a photoresist, a wiring precursor is formed by depositing a metal on the non-mask portion by electrolytic plating. In this case, the mask formation with the photoresist is performed by laminating a commercially available dry film for pattern formation on the metal film layer, in addition to the method of sequentially applying the photoresist, drying, exposing, and developing. It can be performed by exposure and development. The method using such a dry film is advantageous in that fine wiring can be efficiently formed. In addition, although electroplating includes plating of copper, nickel, gold, palladium, etc., copper plating is preferable. The thickness of the wiring precursor is preferably 2 to 100 μm, more preferably 5 to 50 μm. After the wiring precursor is formed, the mask (photoresist, dry film, etc.) is removed.

[Step (C)]
The step (C) in the present invention is a step of heat-treating the substrate after the step (B), and the heat treatment is performed to reduce and stabilize the electric resistance of the wiring formed in the step (D). This is a process of annealing the precursor and the metal film layer. The temperature of the heat treatment is preferably 300 ° C. or less, more preferably 200 ° C. or less, from the viewpoint of preventing decomposition of the resin composition or the substrate material. Furthermore, 150 degreeC or more is preferable from the point of the adhesive improvement of the wiring to an insulating layer, and a wiring density improvement, 170 degreeC or more is more preferable, 180 degreeC or more is further more preferable, and 190 degreeC or more is especially preferable. The heat treatment time is preferably 90 minutes or less, more preferably 80 minutes or less, and still more preferably 70 minutes or less from the viewpoint of improving productivity. Furthermore, from the viewpoint of improving the adhesion of the wiring to the insulating layer and improving the wiring density, it is preferably 30 minutes or more, more preferably 40 minutes or more, and even more preferably 50 minutes or more. The heat treatment atmosphere is not particularly limited, but a nitrogen atmosphere and air are preferable. Moreover, heat processing is normally performed under a normal pressure.

[Step (D)]
The step (D) in the present invention is a step of forming a wiring by removing a metal film layer other than the portion immediately below the wiring precursor by flash etching (that is, a step of forming a wiring having a surface layer of the wiring precursor. Is). Flash etching is usually performed with an etching solution. When the metal film layer is copper, the etching solution includes an aqueous ferric chloride solution; an acidic etching solution such as an aqueous solution containing sodium peroxodisulfate and sulfuric acid; And CF-6000 manufactured by Meltex Co., Ltd., and E-process-WL manufactured by Meltex Co .; an etching solution containing hydrogen peroxide as a main component (hydrogen peroxide-based etching solution). As the hydrogen peroxide-based etching solution, an etching solution containing hydrogen peroxide and an inorganic acid is preferable. Examples of the inorganic acid include sulfuric acid, nitric acid, phosphoric acid, and the like, and sulfuric acid and phosphoric acid are preferable. Any one or a combination of two or more inorganic acids may be used. Examples of commercially available hydrogen peroxide etching solutions include etching solution SAC series (manufactured by Ebara Densan Co., Ltd.). When the metal film layer is nickel, an etchant mainly composed of nitric acid and sulfuric acid can be used as the etchant, and commercially available products include NH-1865 manufactured by Mec Co., Ltd. and Meltex Co., Ltd. Examples include Melstrip N-950 manufactured by

  Although the flash etching can be performed by immersion in an etching solution or spraying of an etching solution, spraying of the etching solution is preferable. That is, the metal film layer other than the portion immediately below the wiring precursor (that is, the portion of the metal film layer not masked with the wiring precursor) is removed by spraying the etching solution.

  From the viewpoint of preventing thinning of the wiring, the temperature of the etching solution is preferably 25 to 50 ° C, and more preferably 25 to 35 ° C. The treatment time is preferably 10 to 120 seconds, more preferably 20 to 60 seconds.

  When flash etching is performed by spraying an etching solution, the spray pressure is preferably 0.01 to 0.5 MPa, and more preferably 0.1 to 0.3 MPa.

  For example, when the width of one wiring (pattern) and the interval between adjacent wirings (patterns) are a line (L) and a space (S), for example, L / S is 5/5. It is preferable to form in the dimension which becomes -50/50 micrometers, and it is more preferable to form in the dimension which becomes 5 / 5-25 / 25 micrometers.

[Step (E)]
The step (E) in the present invention is a wiring surface treatment step. The surface treatment of the wiring here means a treatment including at least wet etching on the surface of the wiring. Specifically, the wiring and an insulating layer (an insulating layer covering the wiring formed after the wiring is formed) In order to improve the adhesion, a process for forming the wiring surface into a rough surface by wet etching, a process for forming an adhesion layer (functional layer) by using a wet etching process on the wiring surface, and the like can be mentioned. The process for forming the adhesion layer (functional layer) may involve wet etching as a pre-treatment before forming the adhesion layer (functional layer), a post-treatment after forming the adhesion layer (functional layer), or the like. Wet etching can be performed with a commercially available etchant. For example, as an etchant for forming a wiring surface into a rough surface by wet etching, “CZ8100” (surface treatment containing an organic acid) manufactured by Mec Co., Ltd. Agent), “BO-7780V” (sulfuric acid-hydrogen peroxide system), “HIST-500 / HIST-10”, “HIST-7300” manufactured by Hitachi Chemical Co., Ltd., “CPE” manufactured by Mitsubishi Gas Chemical Co., Ltd. -700 "(sulfuric acid-hydrogen peroxide system) and the like. Among them," CZ8100 "(a surface treatment agent containing an organic acid) manufactured by MEC Co., Ltd. is preferable. In the case of using “CZ8100” (surface treatment agent containing an organic acid) manufactured by MEC Co., Ltd., it is preferably carried out by spray treatment, under conditions of temperature: 20 to 50 ° C. and spray pressure: 0.1 to 2 MPa. By processing, a rough surface having an arithmetic average roughness (Ra) of 500 to 2000 nm can be formed. The arithmetic average roughness (Ra) of the surface of the wiring is measured using a non-contact type surface roughness meter (“WYKO NT3300” manufactured by Beeco Instruments, Inc.) with a VSI contact mode and a 50 × lens and a measurement range of 121 μm × 92 μm. Can be measured. JIS B0601 is a reference for arithmetic average roughness (Ra). Specific examples of the adhesion layer (functional layer) include, for example, a “MEC flat bond GT process” layer manufactured by MEC Co., Ltd., a “Secure HFz” layer manufactured by Atotech, etc., and formation of the adhesion layer (functional layer) Examples of the pre-treatment and post-treatment wet etching etchant performed in accordance with the above include sulfuric acid-hydrogen peroxide-based, phosphoric acid-based, sodium sulfite-based etchants prepared at low concentrations.

  In the present invention, after the steps (A) to (E) are sequentially performed, a series of steps are repeatedly performed, whereby a multilayer printed wiring board in which build-up layers are stacked in multiple stages can be manufactured.

<Semiconductor device>
Moreover, a semiconductor device can be manufactured using the multilayer printed wiring board obtained by the manufacturing method of this invention. That is, a semiconductor device can be manufactured by mounting a semiconductor chip in a conductive portion of a multilayer printed wiring board obtained by the manufacturing method of the present invention. The “conduction location” is a “location where an electrical signal is transmitted in a multilayer printed wiring board”, and the location may be a surface or an embedded location. The semiconductor chip is not particularly limited as long as it is an electric circuit element made of a semiconductor.

  The semiconductor chip mounting method for manufacturing the semiconductor device of the present invention is not particularly limited as long as the semiconductor chip functions effectively, but specifically, a wire bonding mounting method, a flip chip mounting method, and no bumps. Examples include a mounting method using a build-up layer (BBUL), a mounting method using an anisotropic conductive film (ACF), and a mounting method using a non-conductive film (NCF).

  EXAMPLES Hereinafter, although this invention is demonstrated in detail using an Example and a comparative example, these do not restrict | limit this invention in any meaning. In the following description, “parts” means “parts by mass” and “%” means “% by mass” unless otherwise specified.

[Example 1]
<Production of film with metal film>
On a polyethylene terephthalate (hereinafter referred to as “PET”) film having a thickness of 38 μm, methyl ethyl ketone (hereinafter referred to as “MEK”) having a solid content of hydroxypropyl methylcellulose phthalate (“HP-55” manufactured by Shin-Etsu Chemical Co., Ltd.) is 10%. A 1: 1 (mass ratio) solution of N, N-dimethylformamide (hereinafter abbreviated as “DMF”) is applied by a die coater, and the heating rate is 3 ° C. from room temperature to 140 ° C. using a hot air drying furnace. The solvent was removed by raising the temperature at / sec, and a hydroxypropylmethylcellulose phthalate layer having a thickness of about 1 μm was formed on the PET film. Subsequently, a copper layer of 500 nm was formed on the hydroxypropylcellulose phthalate layer by vapor deposition to produce a film with a metal film.

<Preparation of adhesive film having resin composition layer>
28 parts of liquid bisphenol A type epoxy resin (epoxy equivalent 180, “jER828EL” manufactured by Mitsubishi Chemical Corporation) and naphthalene type tetrafunctional epoxy resin (epoxy equivalent 163, “HP4700” manufactured by Dainippon Ink and Chemicals, Inc.) 28 And 20 parts of phenoxy resin ("YX6954BH30" manufactured by Mitsubishi Chemical Corporation, MEK solution with a solid content of 30%) were dissolved in a mixed solvent of 15 parts of MEK and 15 parts of cyclohexanone with stirring. There, 27 parts of a triazine-containing phenol novolac resin (hydroxyl equivalent 125, “LA7054” manufactured by DIC Corporation, MEK solution nitrogen content of about 12% of solid content 60%), naphthol-based curing agent (hydroxyl equivalent 215, Toto Kasei) "SN-485" 50% solid MEK solution manufactured by Co., Ltd. 27 parts, curing catalyst (Shikoku Kasei Kogyo Co., Ltd., "2E4MZ") 0.1 part, flame retardant (Sanko Co., Ltd. "HCA" -HQ ", 5 parts of 10- (2,5-dihydroxyphenyl) -10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide, average particle size 2 μm), aminosilane coupling agent (Shin-Etsu) 140 parts of spherical silica (average particle size 0.5 μm, “SOC2” manufactured by Admatechs Co., Ltd.) surface-treated with “KBM573” manufactured by Chemical Industry Co., Ltd., polyvinyl butyral resin (manufactured by Sekisui Chemical Co., Ltd.) KS- 1 ", a 15% solid solution of ethanol and toluene (1: 1 solution) (30 parts) was mixed and uniformly dispersed with a high-speed rotary mixer to prepare a resin varnish. The above varnish is applied by a die coater on a PET film (Lintec Co., Ltd.) with an alkyd mold release agent layer (AL-5) having a thickness of 38 μm, the solvent is removed using a hot air drying furnace, and a resin composition layer An adhesive film having a thickness of 40 μm was prepared.

<Preparation of adhesive film with metal film>
The adhesive film with a metal film was obtained by laminating them at 90 ° C. for 10 seconds so that the surface of the resin composition layer of the adhesive film and the metal film surface of the film with the metal film were in contact with each other.

<Lamination and curing of adhesive film with metal film on inner circuit board>
The copper layer of the glass epoxy substrate (inner layer circuit board) on which a circuit was formed with an 18 μm thick copper layer was roughened by a CZ8100 (surface treatment agent containing organic acid (MEC Co., Ltd.)) treatment. Next, the PET film with a release agent of the adhesive film with a metal film is peeled off so that the curable resin composition layer is in contact with the surface of the copper circuit, and a batch type vacuum pressure laminator MVLP-500 (trade name) (Product name manufactured by Seisakusho) was used to laminate on both sides of the substrate. Lamination was performed by reducing the pressure for 30 seconds to a pressure of 13 hPa or less, and then pressure bonding for 30 seconds at 100 ° C. and a pressure of 0.74 MPa. Thereafter, thermosetting was performed at 100 ° C. for 30 minutes and further at 180 ° C. for 30 minutes to form an insulating layer.

<Metal film layer formation>
After peeling off the PET film as the support, the release layer was removed by washing with water, and the copper film layer that appeared on the surface layer was immersed in a ferric chloride aqueous solution at 25 ° C. for 2 minutes to obtain copper on the insulating layer. The film layer was removed by etching, then washed with water and dried. It was visually confirmed that there was no copper film layer on the insulating layer. Next, electroless copper plating (using an electroless copper plating process using Atotech Japan Co., Ltd. pharmaceutical solution) was performed on the insulating layer from which the copper film layer had been etched away. The film thickness of the electroless copper plating layer (copper film layer) was 1 μm.

<Wiring formation>
After the surface of the electroless copper plating layer (copper film layer) was treated with a 5% aqueous sulfuric acid solution for 30 seconds, a dry film for pattern formation (“ALPHA 20A263” manufactured by Nichigo Morton Co., Ltd., thickness 20 μm) was laminated. The lamination of the dry film for pattern formation was performed by using a batch type vacuum pressure laminator (“MVLP-500” manufactured by Meiki Seisakusho Co., Ltd.) to reduce the pressure to 30 hPa or less for 30 seconds, and then to 70 ° C., pressure Lamination was performed at 0.1 MPa for 20 seconds. Next, a glass mask on which a 16 μm pitch comb-tooth pattern (wiring length 15 mm, 16 lines) of L (dry film line) / S (space) = 8/8 μm was formed on the PET film as a protective layer of the dry film. And UV irradiation was performed with a UV lamp at an irradiation intensity of 150 mJ / cm ² . After UV irradiation, spray treatment was performed for 30 seconds using a 1% sodium carbonate aqueous solution at 30 ° C. at an injection pressure of 0.15 MPa. Then, it washed with water and developed (patterning) of the dry film. Thereafter, electrolytic copper plating was performed to form a copper layer (wiring precursor) having a thickness of 15 μm. Subsequently, spray treatment was performed using a 3% sodium hydroxide solution at 50 ° C. at an injection pressure of 0.2 MPa, and the dry film was peeled off. Thereafter, after 60 minutes of heat treatment at 190 ° C., flash etching was performed. Specifically, in the SAC process using an etching solution (SAC series) manufactured by Sakakibara Densan Co., Ltd., extra plating is performed by performing a shower spray at 30 ° C. for 1 minute with a spray pressure of 0.1 MPa. The seed layer (electroless copper plating layer) was removed.

<Surface treatment of wiring>
Thereafter, using a surface treatment agent (“CZ8100” manufactured by MEC Co., Ltd.), the surface of the wiring is subjected to a spray treatment with a spray pressure of 0.2 MPa, and a rough surface having an arithmetic average roughness (Ra) of 1.0 μm. Formed.

<Formation of build-up layer>
The same adhesive film with a metal film as the above adhesive film with a metal film was used, and it was laminated and cured in the same manner as described above to form a buildup layer.

[Example 2]
<Preparation of adhesive film having resin composition layer>
15 parts of liquid bisphenol A type epoxy resin (epoxy equivalent 180, “jER828EL” manufactured by Japan Epoxy Resin Co., Ltd.) and 15 parts biphenyl type epoxy resin (epoxy equivalent 291; “NC3000H” manufactured by Nippon Kayaku Co., Ltd.) While stirring, the mixture was dissolved in 15 parts of MEK and 15 parts of cyclohexanone with stirring. Thereto, 20 parts of active ester compound (“EXB9460S-65T” manufactured by DIC Corporation, active ester equivalent 223, 65% solid content toluene solution), triazine-containing cresol novolak resin (“LA3018-50P” manufactured by DIC Corporation). , Phenol equivalent 151, 2-methoxypropanol solution with 50% solid content) 6 parts, curing accelerator (manufactured by Guangei Chemical Industry Co., Ltd., “4-dimethylaminopyridine”) 0.05 parts, aminosilane coupling agent ( Spherical silica surface treated with Shin-Etsu Chemical Co., Ltd. “KBM573”) (mean particle size 0.5 μm, Admatechs Co., Ltd. “SOC2”) 88 parts, phenoxy resin (YL6954BH30, MEK with 30% non-volatile content) 7 parts of 1: 1 solution of cyclohexanone and cyclohexanone, weight average molecular weight 40000) In uniformly dispersed to prepare a resin varnish. The varnish is coated on a polyethylene terephthalate film (manufactured by Lintec Co., Ltd.) with a alkyd type release agent layer (AL-5) having a thickness of 38 μm using a die coater, and the solvent is removed using a hot air drying oven to obtain a curable resin. An adhesive film having a composition layer thickness of 40 μm was prepared.

<Lamination and curing of adhesive film on inner layer circuit board>
A PET film with a release agent is peeled off on the same inner layer circuit board as used in Example 1, so that the curable resin composition layer is in contact with the copper circuit surface, and a batch type vacuum pressure laminator MVLP-500. (Product name, manufactured by Meiki Seisakusho Co., Ltd.) was used to laminate on both sides of the substrate. Lamination was performed by reducing the pressure for 30 seconds to a pressure of 13 hPa or less, and then pressure bonding for 30 seconds at 100 ° C. and a pressure of 0.74 MPa. Then, it heat-cured for 30 minutes at 180 degreeC, the insulating layer was formed, and the PET film was peeled.

<Roughening treatment>
It is immersed in a swelling dip securigant P of Atotech Japan Co., Ltd., which is a swelling liquid, at 60 ° C. for 5 minutes, and then concentrated as a roughening liquid, Concentrate Compact P (KMnO ₄ : 60 g / g) of Atotech Japan Co., Ltd. L, NaOH: 40 g / L aqueous solution) at 80 ° C. for 10 minutes, and finally, as a neutralizing solution, it was immersed in Atotech Japan Co., Ltd. Reduction Sholyshin Securigant P at 40 ° C. for 5 minutes. Then, it was washed with water and dried.

<Metal film layer formation>
Electroless copper plating (using an electroless copper plating process using a pharmaceutical solution of Atotech Japan Co., Ltd.) was performed on the insulating layer. The film thickness of the electroless copper plating layer was 1 μm. Thereafter, in the same manner as in Example 1, formation of a wiring precursor, heat treatment, flash etching (wiring formation) were performed, and surface treatment of the wiring was further performed.

[Example 3]
In Example 1, without removing the copper film layer by etching, the copper film layer was used as a plating seed layer, and in the same manner as in Example 1, formation of a wiring precursor, heat treatment, and flash etching (wiring formation) were performed. Furthermore, the surface treatment of the wiring was performed.

[Comparative Example 1]
A multilayer printed wiring board was produced in the same manner as in Example 1 except that the heat treatment (heat treatment at 190 ° C. for 60 minutes) was performed after flash etching.

  The following performance evaluation was performed for Examples 1 to 3 and Comparative Example 1 described above. Table 1 shows the results.

<Evaluation of delamination>
After the surface treatment of the wiring, cross-sectional SEM observation of the multilayer printed wiring board was performed using FIB-SEM (manufactured by SII Nanotechnology Co., Ltd., “SMI3050SE”). The case where interface delamination (delamination) between the wiring and the insulating layer was not confirmed was set as “pass (◯)”, and the case where it occurred was set as “impossible (×)”.

<Measurement of arithmetic average roughness (Ra) of insulating layer surface>
Wiring of the wiring boards obtained in Examples and Comparative Examples was removed with a copper etching solution (ferric chloride aqueous solution), and a VSI contact was made using a non-contact type surface roughness meter (“WYKO NT3300” manufactured by Beec Instruments). The arithmetic average roughness (Ra) of the insulating layer surface was determined by setting the measurement range to 121 μm × 92 μm with a mode and 50 × lens. For Ra, three measurement ranges were set at random, and the average value of the three measurement values was adopted.

Claims (10)

The manufacturing method of a multilayer printed wiring board including the process of the following (A)-(E) performed sequentially.
(A): Step of forming an insulating layer having a surface arithmetic average roughness (Ra) of 150 nm or less and a metal film layer laminated on the insulating layer (B): forming a wiring precursor on the metal film layer Step (C): Step of performing heat treatment (D): Step of forming a wiring by removing a metal film layer other than the portion immediately below the wiring precursor by flash etching (E): Surface treatment step of wiring (A) The process is
(I) a step of forming a metal film layer by electroless plating after forming an insulating layer and roughening the surface of the insulating layer;
(Ii) a step of forming an insulating layer and a metal film layer laminated on the insulating layer with an adhesive film with a metal film, or
(Iii) a step of forming an insulating layer and a metal film layer laminated on the insulating layer with an adhesive film with a metal film, removing the metal film layer, and then forming the metal film layer by electroless plating The method of claim 1. The method according to claim 1 or 2, wherein the step (E) is a process of forming the wiring surface into a rough surface by wet etching. The method of any one of Claims 1-3 whose heat processing temperature of a (C) process is 180 degreeC or more. (B) The process is
(i) a step of laminating a dry film on the metal film layer, exposing and developing,
(ii) a process of performing electroplating; and
(iii) The method of any one of Claims 1-4 including the process of removing a dry film. The method according to claim 1, wherein the metal film layer formed in the step (A) is a copper film layer, and the wiring precursor formed in the step (B) is a wiring precursor made of copper. The method according to claim 1, wherein the flash etching in the step (D) is performed by spraying a hydrogen peroxide-based etching solution at 25 to 50 ° C. for 10 to 120 seconds.   The method according to claim 1, wherein the insulating layer comprises a cured product of a resin composition including an epoxy resin, an epoxy curing agent, and an inorganic filler.   The multilayer printed wiring board manufactured by the method of any one of Claims 1-8.   A semiconductor device comprising the multilayer printed wiring board according to claim 9.