Method for manufacturing circuit board

Abstract

Provided is a novel method for manufacturing a circuit board in which a high polishing speed can be achieved and an insulating layer having a small surface roughness can be achieved in the manufacturing of a circuit board in which an insulating layer is chemically and mechanically polished. The method for manufacturing the circuit board is characterized by comprising the following steps (X), (Y), and (Z): (X) a step for forming a resin composition layer from a resin composition (R) so as to embed a conductor pillar on a substrate having the conductor pillar for interlayer connection provided on the surface thereof, and curing the resin composition layer to form an insulating layer; (Y) a step for exposing the conductor pillar by polishing the insulating layer by chemical mechanical polishing (CMP); and (Z) a step for forming a plating seed layer on the surface of the insulating layer, where Tg1 is the glass transition temperature (DEG C) of a cured product obtained by curing the resin composition R under the curing conditions in step (X), and Tg2 is the glass transition temperature (DEG C) of a cured product obtained by curing the resin composition R at 200 DEG C for 120 minutes, and Tg2 is the glass transition temperature (DEG C) of the cured product obtained by curing the resin composition R at 200 DEG C for 120 minutes. The step (X) is performed so as to satisfy 0.5 < = Tg1 / Tg2 < = 0.9.

Description

Technical Field

[0001] This invention relates to a method for manufacturing a circuit board. Background Technology

[0002] In the manufacture of semiconductor packages such as wafer-level packaging (WLP) and panel-level packaging (PLP), circuit substrates such as redistribution substrates are typically formed as follows: a curable resin material is placed on the wafer or panel substrate and cured to form an insulating layer, and a conductor layer is formed on the insulating layer. This operation is repeated to achieve multilayering, thereby forming (for example, Patent Document 1).

[0003] Existing technical documents Patent documents Patent document 1: Japanese Patent Application Publication No. 2012-015191. Summary of the Invention

[0004] The problem that the invention aims to solve With the increasing performance of electronic devices, there is a growing demand for finer wiring in circuit boards used in semiconductor packaging. A desirable technique is chemical-mechanical polishing (CMP), a proven method for forming fine wiring based on precision polishing, to polish the insulating layer and form a conductive layer on the polished surface of the resulting insulating layer to manufacture the circuit board. This is because the surface of the insulating layer after chemical-mechanical polishing (the polished surface) is flat and smooth, which facilitates the miniaturization of the conductive layer formed thereon.

[0005] On the other hand, from the perspective of improving the productivity of semiconductor packaging, high-speed processing is being pursued in each production process, including chemical mechanical polishing (CMP) of insulating layers. Regarding this, when CMP polishing insulating layers, adjusting polishing conditions (rotation speed, pressure, type and concentration of polishing compound) to increase the polishing speed results in a larger surface roughness of the resulting insulating layer, diminishing the advantages of CMP. Furthermore, regarding insulating layers used in circuit boards, to achieve characteristics such as low thermal expansion coefficient and low dielectric loss tangent, inorganic filler materials such as silicon dioxide are sometimes included. However, it has been found that in such cases, the aforementioned problems become more pronounced. Specifically, it has been found that when CMP polishing insulating layers containing inorganic filler materials, increasing the polishing speed causes the inorganic filler material near the surface of the insulating layer to detach, resulting in surface depression and a larger surface roughness of the resulting insulating layer.

[0006] This invention provides a novel method for manufacturing a circuit board, wherein in the manufacturing of a circuit board by chemical mechanical polishing of the insulating layer, high polishing speed and low surface roughness of the insulating layer can be achieved. In other words, this invention provides a novel technology that, in the manufacturing of a circuit board by chemical mechanical polishing of the insulating layer, achieves both high-speed polishing, which was previously difficult to achieve, and the formation of an insulating layer with low surface roughness.

[0007] means for solving problems In order to solve the above-mentioned problems, the inventors conducted in-depth research and found that the above-mentioned problems can be solved by a method for manufacturing a circuit board having the following configuration, thereby completing the present invention.

[0008] That is, the present invention includes the following contents.

[0009] <1> A method for manufacturing a circuit board, comprising the following steps (X), (Y), and (Z): (X) A process of forming a resin composition layer by embedding the conductor post on a substrate on which an interlayer connection conductor post is provided on the surface, and curing the resin composition layer to form an insulating layer. (Y) The process of exposing the conductor pillars by grinding the insulating layer through chemical mechanical polishing (CMP); and (Z) The process of forming a seed layer on the surface of the insulating layer. When the glass transition temperature (°C) of the cured product obtained by curing the resin composition R using the curing conditions in step (X) is set as Tg1, and the glass transition temperature (°C) of the cured product obtained by curing the resin composition R at 200°C for 120 minutes is set as Tg2, step (X) is performed in such a way that 0.5≤Tg1 / Tg2≤0.9 is satisfied.

[0010] <2> according to <1> The method wherein, in step (Z), a coating seed layer is formed by sputtering.

[0011] <3> according to <1> or <2> The method, wherein step (X) includes: laminating a resin sheet comprising a support and a resin composition layer disposed on the support onto a substrate in such a manner that the resin composition layer is bonded to a conductor post.

[0012] <4> according to <1> ~ <3> In any one of the methods, the amount (thickness) of the insulating layer being ground in step (Y) is 1 μm or more.

[0013] <5> according to <1> ~ <4> In any one of the methods, the grinding speed of the insulating layer in step (Y) is 1 μm / min or more.

[0014] <6> according to <1> ~ <5> In any one of the methods, the arithmetic mean roughness Ra of the polished surface of the insulating layer obtained in step (Y) is less than 70 nm.

[0015] <7> according to <1> ~ <6> In any one of the methods, the thickness of the deposited seed layer formed in step (Z) is less than 500 nm.

[0016] <8> according to <1> ~ <7> The method described in any one of the following methods includes: a step of forming a conductor layer on a seed layer by electrolytic plating.

[0017] <9> according to <1> ~ <8> The method of any one of the following, wherein the resin composition R comprises a thermosetting resin.

[0018] <10> according to <1> ~ <9> In any one of the methods, when the non-volatile component in the resin composition R is set to 100% by mass, the content of the inorganic filler material in the resin composition R is 40% by mass or more.

[0019] <11> according to <1> ~ <10> In any one of the methods, the resin composition R comprises an inorganic filler material treated with an alkoxy-containing surface treatment agent.

[0020] <12> according to <11> The method wherein the alkoxy-containing surface treatment agent is selected from one or more alkoxy-containing silane coupling agents and their oligomers.

[0021] <13> according to <11> or <12> In the method described, the carbon content per unit surface area of ​​the inorganic filler material is 0.05 mg / m². 2 above.

[0022] <14> according to <1> ~ <13> In any one of the methods, Tg2 is above 150°C.

[0023] <15> according to <1> ~ <14> The method described in any one of the following statements, wherein the circuit board is used for semiconductor packaging.

[0024] Invention Effects According to the present invention, a novel method for manufacturing a circuit board is provided that enables high grinding speed and low surface roughness of the insulating layer in the manufacture of a circuit board in which the insulating layer is chemically and mechanically polished. That is, the present invention provides a novel technology that combines, in the manufacture of a circuit board in which the insulating layer is chemically and mechanically polished, the previously difficult-to-achieve high-speed polishing and the formation of an insulating layer with low surface roughness. Detailed Implementation

[0025] Before providing a detailed description of the manufacturing method of the circuit board of the present invention, the resin composition (“resin composition R”) used in the manufacturing method of the present invention will be described.

[0026] <Resin Composition> In the method for manufacturing the circuit board of the present invention, a resin composition layer is formed using a resin composition R in a manner that embeds conductor pillars for interlayer connections, and the resin composition layer is cured to form an insulating layer. Here, the resin composition R is not particularly limited as long as it can be formed in a manner that embeds conductor pillars and exhibits sufficient insulation after curing. Hereinafter, suitable embodiments will be described from the viewpoint of further enjoying the effects of the present invention.

[0027] From the viewpoint of achieving a cured product exhibiting good insulation properties and good heat resistance, the resin composition R comprises (a) a curable resin, and further, as needed, may comprise one or more selected from (b) a curing agent, (c) an inorganic filler, (d) a thermoplastic resin, and (e) a curing accelerator. Hereinafter, the components that may be contained in the resin composition will be described.

[0028] -(a) Curing resin- As the curing resin, conventionally known curing resins used in forming the insulating layer of a circuit board can be used. According to the circuit board manufacturing method of the present invention, regardless of the type of curing resin, it is possible to achieve both high-speed grinding and the formation of an insulating layer with low surface roughness.

[0029] From the viewpoint of achieving a cured product that simultaneously exhibits good insulation and heat resistance, the curable resin is preferably selected from one or more thermosetting resins and free radical polymerizable resins.

[0030] Examples of thermosetting resins include epoxy resins, polyarylene ether resins, benzocyclobutene resins, epoxy acrylate resins, urethane acrylate resins, urethane resins, cyanate ester resins, melamine resins, and silicone resins. A single thermosetting resin can be used alone, or two or more can be used in combination. From the viewpoint of achieving a cured product that simultaneously exhibits good insulation and good heat resistance, epoxy resin is preferably included as the curing resin.

[0031] There is no particular limitation on the type of epoxy resin as long as it has one or more (preferably two or more) epoxy groups in one molecule. 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, phenolic varnish type epoxy resin, tert-butyl-catechol type epoxy resin, naphthol type epoxy resin, naphthalene type epoxy resin, naphthyl ether type epoxy resin, glycidylamine type epoxy resin, glycidyl ester type epoxy resin, cresolic varnish type epoxy resin, biphenyl type epoxy resin, phenol aralkyl type epoxy resin, biphenyl aralkyl type epoxy resin, fluorene skeleton type epoxy resin, dicyclopentadiene type epoxy resin, anthracene type epoxy resin, linear aliphatic epoxy resin, epoxy resin with butadiene structure, alicyclic epoxy resin, heterocyclic epoxy resin, epoxy resin containing spirocyclic ring, cyclohexanediol type epoxy resin, tris(hydroxymethyl) type epoxy resin, halogenated epoxy resin, etc.

[0032] Epoxy resins can be classified into epoxy resins that are liquid at 20°C (hereinafter referred to as "liquid epoxy resins") and epoxy resins that are solid at 20°C (hereinafter referred to as "solid epoxy resins"). The resin composition R, as a curing resin, may contain only liquid epoxy resin, only solid epoxy resin, or a combination of both. When both liquid and solid epoxy resins are combined, the mixing ratio (liquid:solid) can be set to a range of 20:1 to 1:20 by mass (preferably 10:1 to 1:10, more preferably 3:1 to 1:3).

[0033] The epoxy equivalent of the epoxy resin is preferably 50 g / eq. to 2000 g / eq., more preferably 60 g / eq. to 1000 g / eq., and even more preferably 80 g / eq. to 500 g / eq. The epoxy equivalent is the mass of epoxy resin containing 1 equivalent of epoxy groups, and can be determined according to JIS K7236.

[0034] The weight-average molecular weight (Mw) of the epoxy resin is preferably 100 to 5,000, more preferably 250 to 3,000, and even more preferably 400 to 1,500. The Mw of the epoxy resin can be determined by gel permeation chromatography (GPC) and expressed as a polystyrene equivalent.

[0035] There are no particular limitations on the types of polyarylether resins as long as they possess a polyarylether backbone and exhibit crosslinking properties through the reaction of terminal hydroxyl groups and other functional groups. Examples of polyarylether resins include polyphenylene ether resins and polynaphthalene ether resins; these can be homopolymers or copolymers. Examples of homopolymers of polyphenylene ether resins include those containing 2,6-dicarbonyl groups. 1~3Homopolymers of alkyl-1,4-phenyl ether units, as copolymers thereof, include, for example, combinations containing 2,6-dicarbonyl groups. 1~3 alkyl-1,4-phenyl ether units and 2,3,6-tricarbonyl units 1~3 Grafted, block, or random copolymers of alkyl-1,4-phenyl ether units, etc. Examples of polyaryl ether resins include, for instance, "Noryl (registered trademark) SA90" manufactured by SABIC.

[0036] The number-average molecular weight (Mn) of the polyarylene ether resin is preferably 200-5,000, more preferably 400-3,000, and even more preferably 600-2,500. The Mn of the polyarylene ether resin can be determined using the GPC method and expressed as a polystyrene equivalent.

[0037] As a free radical polymerizable resin, there is no particular limitation on its type, as long as it has one or more (preferably two or more) free radical polymerizable unsaturated groups in one molecule. Examples of free radical polymerizable resins include resins having one or more free radical polymerizable unsaturated groups selected from maleimide, vinyl, allyl, styrene, vinylphenyl, acryloyl, methacryloyl, fumaroyl, and maleyl. From the viewpoint of achieving a cured product that simultaneously exhibits good insulation and good heat resistance, the curable resin preferably contains one or more selected from maleimide resins, (meth)acrylic resins, and styrene resins.

[0038] As a maleimide resin, there is no particular limitation on its type as long as it has one or more (preferably two or more) maleimide groups (2,5-dihydro-2,5-dioxo-1H-pyrrole-1-yl) in one molecule. Examples of maleimide resins include, for instance, "BMI-3000J", "BMI-5000", "BMI-1400", "BMI-1500", "BMI-1700", and "BMI-689" (all manufactured by Designer Molecules Inc.), which contain an aliphatic skeleton (preferably an aliphatic skeleton containing a ring structure with 10 or more carbon atoms, more preferably an aliphatic skeleton with 36 carbon atoms derived from a dimer diamine); the maleimide resin containing an indane skeleton described in Patent Application Publication No. 2020-500211; and maleimide resins containing an aromatic ring skeleton directly bonded to the nitrogen atom of the maleimide group, such as "MIR-3000-70MT" (manufactured by Nippon Kayaku Co., Ltd.), "BMI-4000", "BMI-1000" (manufactured by Yamato Kasei Co., Ltd.), and "BMI-80" (manufactured by KI Kasei Co., Ltd.).

[0039] As a (meth)acrylic resin, there is no particular limitation on its type as long as it has one or more (meth)acryloyl groups in one molecule, and it can be a monomer or an oligomer. Here, the term "(meth)acryloyl group" is a general term for acryloyl group and methacryloyl group. In addition to (meth)acrylate monomers, other (meth)acrylic resins that can be listed include, for example, "A-DOG" (manufactured by Shin-Nakamura Chemical Industry Co., Ltd.), "DCP-A" (manufactured by Kyoeisha Chemical Co., Ltd.), "NPDGA", "FM-400", "R-687", "THE-330", "PET-30", and "DPHA" (all manufactured by Nippon Kayaku Co., Ltd.).

[0040] As a styrene-based resin, there is no particular limitation on its type, as long as it has one or more (preferably two or more) styrene or vinylphenyl groups in one molecule; it can be a monomer or an oligomer. Examples of styrene-based resins include "OPE-2St", "OPE-2St 1200", and "OPE-2St 2200" (all manufactured by Mitsubishi Gas Chemical Co., Ltd.). In addition to styrene monomers, examples of styrene-based resins include homopolymers of aromatic divinyl compounds such as divinylbenzene, 2,4-divinyltoluene, 2,6-divinylnaphthalene, 1,4-divinylnaphthalene, 4,4'-divinylbiphenyl, 1,2-bis(4-vinylphenyl)ethane, 2,2-bis(4-vinylphenyl)propane, and bis(4-vinylphenyl) ether; or copolymers of these aromatic divinyl compounds with aromatic monovinyl compounds such as styrene, vinyltoluene, ethylstyrene, and vinylnaphthalene.

[0041] In the resin composition R, the curable resin may consist only of a thermosetting resin, or only of a free radical polymerizable resin, or a combination of a thermosetting resin and a free radical polymerizable resin. In one embodiment, the resin composition R comprises a thermosetting resin.

[0042] From the viewpoint of achieving a cured product that simultaneously exhibits good insulation and good heat resistance, and from the viewpoint of further enjoying the effects of the present invention, when the resin component in the resin composition is set to 100% by mass, the content of curable resin in the resin composition is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 12% by mass or more, 14% by mass or more, or 15% by mass or more. There is no particular upper limit to this content; it can be determined according to the desired characteristics of the resin composition, and can be 100% by mass, for example, it can be 90% by mass or less, 80% by mass or less, 70% by mass or less, or 60% by mass or less, etc.

[0043] In this invention, the term "resin component" as used in relation to a resin composition refers to the components other than the inorganic filler materials described later among the non-volatile components constituting the resin composition.

[0044] -(b) Curing agent- The resin composition R may also include a curing agent. There are no particular limitations on the curing agent as long as it has the function of curing the curable resin; examples include phenol-based curing agents, naphthol-based curing agents, reactive ester-based curing agents, acid anhydride-based curing agents, benzoxazine-based curing agents, cyanate ester-based curing agents, carbodiimide-based curing agents, and amine-based curing agents. A single curing agent may be used, or two or more may be used in combination.

[0045] From the viewpoint of heat resistance and water resistance, phenolic curing agents or naphthol curing agents with a phenolic varnish structure are preferred as phenolic curing agents and naphthol curing agents with a phenolic varnish structure. Furthermore, from the viewpoint of achieving an insulating layer with good adhesion strength (peel strength) to the conductor layer, nitrogen-containing phenolic curing agents or nitrogen-containing naphthol curing agents are preferred, and phenolic curing agents or naphthol curing agents containing a triazine skeleton are more preferred. Among these, from the viewpoint of achieving highly satisfactory heat resistance, water resistance, and adhesion strength to the conductor layer, phenolic varnish resins containing a triazine skeleton are preferred.

[0046] Specific examples of phenol-based and naphthol-based curing agents include: "MEH-7700", "MEH-7810", "MEH-7851", and "MEH-8000H" manufactured by Meiwa Chemical Co., Ltd.; "NHN", "CBN", and "GPH" manufactured by Nippon Kayaku Co., Ltd.; and "SN-170", "SN-180", "SN-190", "SN-475", "SN-485", "SN-495", "SN-495V", and "SN-375" manufactured by Nippon Steel Chemical & Materials Co., Ltd. "SN-395"; "TD-2090", "TD-2090-60M", "LA-7052", "LA-7054", "LA-1356", "LA-3018", "LA-3018-50P", "EXB-9500", "HPC-9500", "KA-1160", "KA-1163", "KA-1165" manufactured by DIC Company; "GDP-6115L", "GDP-6115H", "ELPC75" manufactured by Qunrong Chemical Company, etc.

[0047] As an active ester-based curing agent, a compound having one or more active ester groups per molecule can be used. Among these, compounds having two or more highly reactive ester groups per molecule, such as phenolic esters, thiophenolic esters, N-hydroxyamine esters, and heterocyclic hydroxyl esters, are preferred. This active ester-based curing agent is preferably obtained through a condensation reaction of a carboxylic acid compound and / or a thiocarboxylic acid compound with a hydroxyl compound and / or a thiol compound. Especially from the viewpoint of improving heat resistance, an active ester-based curing agent derived from a carboxylic acid compound is preferred, more preferably an active ester-based curing agent obtained from a carboxylic acid compound and a hydroxyl compound, and even more preferably an active ester-based curing agent obtained from a carboxylic acid compound and an aromatic hydroxyl compound.

[0048] As a carboxylic acid compound, any of aromatic carboxylic acid compounds and aliphatic carboxylic acids can be used, such as benzoic acid, acetic acid, succinic acid, maleic acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, and pyromellitic acid.

[0049] Examples of aromatic hydroxyl compounds include (i) addition polymerization products of unsaturated aliphatic cyclic compounds containing two double bonds in one molecule with phenols, (ii) various bisphenol compounds, (iii) aromatic polyols with two or more hydroxyl groups bonded to the carbon atoms of the aromatic ring, and (iv) aromatic monohydric alcohols with one hydroxyl group bonded to the carbon atoms of the aromatic ring. Examples of addition polymerization products of unsaturated aliphatic cyclic compounds with phenols include, for example, addition polymerization products of unsaturated aliphatic cyclic compounds such as dicyclopentadiene, tetrahydroindene, norbornene, limonene, and vinylcyclohexene with phenols optionally having substituents (e.g., phenol, cresol, xylenol, ethylphenol, propylphenol, vinylphenol, allylphenol, phenylphenol, benzylphenol, halogenated phenols, etc.). Specifically, examples include dicyclopentadiene-phenol addition polymers. Examples of bisphenol compounds include bisphenol A, bisphenol F, bisphenol AF, bisphenol AP, bisphenol B, bisphenol BP, bisphenol C, and bisphenol M. Examples of aromatic polyols containing two or more hydroxyl groups bonded to the carbon atom of the aromatic ring include hydroquinone, resorcinol, catechol, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, phloroglucinol, phenyl phenolic varnish, etc. Examples of aromatic monohydric alcohols that have a hydroxyl group bonded to a carbon atom on an aromatic ring include phenol, cresol, xylenol, ethylphenol, propylphenol, vinylphenol, allylphenol, phenylphenol, benzylphenol, halogenated phenol, naphthol, methylnaphthol, dimethylnaphthol, ethylnaphthol, propylnaphthol, vinylnaphthol, allylnaphthol, phenylnaphthol, benzylnaphthol, and halogenated naphthol.

[0050] Suitable examples of reactive ester-based curing agents include reactive ester compounds containing a dicyclopentadiene-type diphenol structure, reactive ester compounds containing a naphthalene structure, reactive ester compounds containing acetylated derivatives of phenolic varnishes, and reactive ester compounds containing benzoyl derivatives of phenolic varnishes. More preferably, these are reactive ester compounds containing a naphthalene structure or reactive ester compounds containing a dicyclopentadiene-type diphenol structure. "Dicyclopentadiene-type diphenol structure" refers to a divalent structural unit containing a phenylene-biscyclopentylene-phenylene group.

[0051] Commercially available reactive ester curing agents include, for example, reactive ester resins containing a dicyclopentadiene-type diphenol structure such as "EXB-9451", "EXB-9460", "EXB-9460S", "HPC-8000-65T", "HPC-8000H-65TM", and "HPC-8000L-65TM" (manufactured by DIC); and reactive ester resins containing a naphthalene structure such as "EXB-8100L-65T", "EXB-8150-60T", "EXB-8150-62T", "EXB-9416-70BK", "HPC-8150-60T", and "HPC-81 Examples of reactive ester resins include “50-62T”, “HP-B-8151-62T”, and “HP-C-8151-62T” (manufactured by DIC Corporation); “EXB9401” (manufactured by DIC Corporation) is an example of a phosphorus-containing reactive ester resin; “DC808” (manufactured by Mitsubishi Chemical Corporation) is an example of an acetylated reactive ester resin belonging to phenolic varnishes; “YLH1026”, “YLH1030”, and “YLH1048” (manufactured by Mitsubishi Chemical Corporation) are examples of reactive ester resins containing styrene and naphthalene structures; and “PC1300-02-65MA” (manufactured by AIR WATER Corporation) is an example of a reactive ester resin containing styrene and naphthalene structures.

[0052] Anhydride-based curing agents include those having one or more anhydride groups per molecule. Specific examples of anhydride-based curing agents include phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylnadic anhydride, hydrogenated methylnadic anhydride, trialkyltetrahydrophthalic anhydride, dodecenylsuccinic anhydride, 5-(2,5-dioxotetrahydro-3-furanyl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, trimellitic anhydride, and pyromellitic anhydride. Polymer-type anhydrides include benzophenone tetracarboxylic dianhydride, biphenyl tetracarboxylic dianhydride, naphthalene tetracarboxylic dianhydride, oxydiphthalic dianhydride, 3,3'-4,4'-diphenyl sulfone tetracarboxylic dianhydride, 1,3,3a,4,5,9b-hexahydro-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphtho[1,2-C]furan-1,3-dione, ethylene glycol bis(trimethoxytriester anhydride), and styrene-maleic acid resin copolymerized from styrene and maleic acid. Commercially available anhydride-based curing agents include "MH-700" manufactured by Shin Nippon Rikka Co., Ltd.

[0053] Specific examples of benzoxazine-based curing agents include JFE Chemicals' "JBZ-OD100" (benzoxazine ring equivalent of 218), "JBZ-OP100D" (benzoxazine ring equivalent of 218), and "ODA-BOZ" (benzoxazine ring equivalent of 218); Shikoku Chemicals' "Pd" (benzoxazine ring equivalent of 217) and "Fa" (benzoxazine ring equivalent of 217); and Showa Polymers' "HFB2006M" (benzoxazine ring equivalent of 432), etc.

[0054] Examples of difunctional cyanate ester resins that can be used as cyanate ester curing agents include bisphenol A dicyanate, polyphenol cyanate, oligomeric (3-methylene-1,5-phenylene cyanate), 4,4'-methylenebis(2,6-dimethylphenyl cyanate), 4,4'-ethoxydiphenyl dicyanate, hexafluorobisphenol A dicyanate, 2,2-bis(4-cyanoxy)phenylpropane, 1,1-bis(4-cyanoxyphenylmethane), bis(4-cyanoxy-3,5-dimethylphenyl)methane, 1,3-bis(4-cyanoxyphenyl-1-(methylethoxy))benzene, bis(4-cyanoxyphenyl) sulfide, and bis(4-cyanoxyphenyl) ether; polyfunctional cyanate ester resins derived from phenolic varnishes and cresol varnishes; and prepolymers obtained by partially triazinizing these cyanate ester resins. Specific examples of cyanate ester-based curing agents include Arxada's "PT30" and "PT60" (phenolic varnish-type multifunctional cyanate ester resins), "ULL-950S" (multifunctional cyanate ester resins), "BA230", and "BA230S75" (prepolymers formed by triazinization of part or all of bisphenol A dicyanate to form trimers).

[0055] Specific examples of carbodiimide-based curing agents include Carbodilite (registered trademark) V-03 (carbodiimide equivalent: 216 g / eq.), V-05 (carbodiimide equivalent: 262 g / eq.), V-07 (carbodiimide equivalent: 200 g / eq.), and V-09 (carbodiimide equivalent: 200 g / eq.) manufactured by Nisshinbo Chemical Co., Ltd.; and STABAXOL (registered trademark) P (carbodiimide equivalent: 302 g / eq.) manufactured by LANXESS Co., Ltd.

[0056] As amine-based curing agents, examples include curing agents having one or more amino groups within one molecule, such as aliphatic amines, polyether amines, alicyclic amines, and aromatic amines. Specific examples of amine-based curing agents include 4,4'-methylenebis(2,6-dimethylaniline), diphenyl diamino sulfone, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, m-phenylenediamine, m-phenylenediamine, diethyltoluenediamine, 4,4'-diaminodiphenyl ether, 3,3'-dimethyl-4,4'-diaminobiphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dihydroxybenzidine, and 2,2-bis(3-amino- 4-Hydroxyphenyl)propane, 3,3-dimethyl-5,5-diethyl-4,4-diphenylmethanediamine, 2,2-bis(4-aminophenyl)propane, 2,2-bis(4-(4-aminophenoxy)phenyl)propane, 1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, bis(4-(4-aminophenoxy)phenyl)sulfone, bis(4-(3-aminophenoxy)phenyl)sulfone, etc. Amine-based curing agents can be commercially available, such as "KAYABOND C-200S", "KAYABOND C-100", "KAYAHARDA-A", "KAYAHARD AB", "KAYAHARD AS" manufactured by Nippon Kayaku Co., Ltd., and "EPICURE W" manufactured by Mitsubishi Chemical Co., Ltd., etc.

[0057] When the resin composition R contains a curing agent, and the resin component in the resin composition is set to 100% by mass, the content of the curing agent is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 15% by mass or more. The upper limit of the curing agent content is preferably 60% by mass or less, more preferably 50% by mass or less, or 40% by mass or less.

[0058] -(c) Inorganic filler materials- The resin composition R may also contain inorganic fillers. By including inorganic fillers, it is possible to achieve an insulating layer with low linear thermal expansion coefficient and low dielectric loss tangent.

[0059] Examples of inorganic filler materials include silica, alumina, glass, cordierite, silicon oxide, barium sulfate, barium carbonate, talc, clay, mica powder, zinc oxide, hydrotalcite, boehmite, aluminum silicate, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, magnesium oxide, boron nitride, aluminum nitride, manganese nitride, aluminum borate, strontium carbonate, strontium titanate, calcium titanate, magnesium titanate, bismuth titanate, titanium oxide, zirconium oxide, barium titanate, barium zirconate titanate, barium zirconate, calcium zirconate, zirconium phosphate, and zirconium tungstate phosphate. Among these, silica is particularly suitable. Examples of silica include amorphous silica, fused silica, crystalline silica, synthetic silica, and hollow silica. Furthermore, spherical silica is preferred. One type of inorganic filler material can be used alone, or two or more types can be used in combination.

[0060] Commercially available inorganic filler materials include, for example, "UFP-30" manufactured by Denka Chemical Industry Co., Ltd.; "SP60-05" and "SP507-05" manufactured by Nippon Steel Chemical & Materials Co., Ltd.; "YC100C", "YA050C", "YA050C-MJE", and "YA010C" manufactured by ADMATECHS Co., Ltd.; "UFP-30" manufactured by DENKA Co., Ltd.; and "SILFIL NSS-3N", "SILFIL NSS-4N", and "SILFIL NSS-4N" manufactured by TOKUYAMA Co., Ltd. NSS-5N; ADMATECHS's SC2500SQ, SO-C4, SO-C2, SO-C1; DENKA's DAW-03, FB-105FD; Pacific Cement's Selphys, MGH-005; and Nippon Kaisha Chemicals' ESFellic, BA-1, etc.

[0061] The average particle size of the inorganic filler material is not particularly limited, but is preferably 5 μm or less, more preferably 3 μm or less, 2 μm or less, 1 μm or less, or 0.7 μm or less. The lower limit of this average particle size is not particularly limited, but is preferably 0.01 μm or more, more preferably 0.05 μm or more, and even more preferably 0.07 μm or more, 0.1 μm or more, or 0.2 μm or more. The average particle size of the inorganic filler material can be determined by laser diffraction / scattering based on the Mie scattering theory. Specifically, a laser diffraction scattering particle size distribution measuring device can be used to prepare the particle size distribution of the inorganic filler material according to a volume basis, and the median particle size can be set as the average particle size for measurement. The sample for measurement can be a substance obtained by weighing 100 mg of inorganic filler material and 10 g of methyl ethyl ketone into a vial and dispersing it using ultrasound for 10 minutes. For the sample being measured, a laser diffraction particle size distribution measuring device is used. The light source wavelength is set to blue and red, and the particle size distribution of the inorganic filler material is measured using a flow cell method based on a volume reference. The average particle size is calculated from the obtained particle size distribution in the form of median particle size. Examples of laser diffraction particle size distribution measuring devices include, for example, the "LA-960" manufactured by Horiba Manufacturing Co., Ltd.

[0062] The specific surface area of ​​the inorganic filler material is not particularly limited, but is preferably 0.1 m². 2 / g or more, preferably 0.5m 2 / g or more, further preferably 1m 2 / g or more, 3m 2 / g or more or 5m 2 / g or more. There is no particular upper limit to this specific surface area, but it is preferably 100m². 2 / g or less, preferably 80m 2 / g or less, more preferably 60m 2 / g or less, 50m 2 / g or less or 40m 2 / g or less. The specific surface area of ​​inorganic filler materials can be obtained as follows: according to the BET method, using a specific surface area measuring device (Macsorb HM-1210 manufactured by MOUNTECH), nitrogen gas is adsorbed onto the sample surface, and the specific surface area is calculated using the BET multi-point method.

[0063] Inorganic filler materials are preferably surface-treated using appropriate surface treatment agents. Surface treatment improves the moisture resistance and dispersibility of the inorganic filler material. Examples of surface treatment agents include, for instance, vinyl-based silane coupling agents, epoxy-based silane coupling agents, styrene-based silane coupling agents, (meth)acrylic acid-based silane coupling agents, amino-based silane coupling agents, isocyanurate-based silane coupling agents, urea-based silane coupling agents, mercapto-based silane coupling agents, isocyanate-based silane coupling agents, anhydride-based silane coupling agents, and other silane coupling agents; alkoxysilane compounds such as methyltrimethoxysilane and phenyltrimethoxysilane; silazane compounds; and their oligomers. A single surface treatment agent can be used, or two or more can be used in combination.

[0064] From the viewpoint that an insulating layer with a smaller surface roughness can be achieved in the manufacture of a circuit board in which the insulating layer is chemically and mechanically polished, the surface treatment agent is preferably an alkoxy-containing surface treatment agent, and more preferably one or more selected from alkoxy-containing silane coupling agents and their oligomers (hereinafter also referred to as "alkoxy oligomers").

[0065] From the viewpoint of further enjoying the effects of the present invention, silane coupling agents containing alkoxy groups are preferred as alkoxy groups and having one or more functional groups selected from amino, epoxy, and mercapto groups. One type or a combination of two or more can be used. In alkoxy-containing silane coupling agents, one or more functional groups may be present.

[0066] Specific examples of this silane coupling agent include aminopropylmethoxysilane, aminopropyltriethoxysilane, ureopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-2-(aminoethyl)aminopropyltrimethoxysilane, and other aminosilane-based silane coupling agents containing alkoxy groups; epoxypropoxypropyltrimethoxysilane, epoxypropoxypropyltriethoxysilane, epoxypropoxypropylmethyldiethoxysilane, glycidylbutyltrimethoxysilane, (3,4-epoxycyclohexyl)ethyltrimethoxysilane, and other epoxysilane-based silane coupling agents containing alkoxy groups; and mercaptopropyltrimethoxysilane, mercaptopropyltriethoxysilane, and other mercaptosilane-based silane coupling agents containing alkoxy groups. In addition, commercially available products as such silane coupling agents include, for example, "KBM403" (3-epoxypropoxypropyltrimethoxysilane), "KBM573" (N-phenyl-3-aminopropyltrimethoxysilane), "KBM803" (3-mercaptopropyltrimethoxysilane), and "KBE903" (3-aminopropyltriethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd.

[0067] As alkoxy oligomers, there are no particular limitations as long as they are oligomers of the aforementioned silane coupling agents containing alkoxy groups. From the viewpoint of further enjoying the effects of the present invention, alkoxysilane resins containing epoxy groups, alkoxysilane resins containing mercapto groups, and alkoxysilane resins containing amino groups are preferred. One type or two or more types can be used. In alkoxy oligomers, one or more functional groups can be present.

[0068] Specific examples of this alkoxy oligomer include alkoxysilyl resins containing epoxypropoxyalkyl groups, alkoxysilyl resins containing aminoalkyl groups, alkoxysilyl resins containing mercaptoalkyl groups, and alkoxysilyl resins containing ureoalkyl groups, with the latter being preferred.

[0069] From the perspective of preventing volatilization and improving processability, the viscosity (25°C) of the alkoxy oligomer is preferably 10 mm. 2 / s or higher, preferably 20mm 2 / s or higher, further preferably 30mm 2 / s or higher, 40mm 2 / s or above or 50mm 2 / s or more. On the other hand, from the viewpoint of effectively covering the inorganic filler, 2000mm is preferred. 2 / s or less, preferably 1800mm 2 / s or less, 1600mm 2 / s or less or 1500mm 2 The viscosity (at 25°C) of alkoxy oligomers can be determined as follows: using an E-type viscometer, approximately 0.2 mL of the alkoxy oligomer is measured into the apparatus adjusted to 25°C using a syringe, and the measurement is performed at a speed set to 5-20 rpm.

[0070] There are no particular limitations on the method for manufacturing alkoxy oligomers. They can be manufactured using known methods such as Japanese Patent No. 3474007, and can be obtained by partially hydrolyzing and condensing the alkoxy group of the silane coupling agent, which is a monomer. For example, a hydrolysis and condensation reaction is carried out at 20 to 80°C for 0.1 to 10 hours by adding a silane coupling agent and an organic solvent to a reaction vessel. In this case, hydrochloric acid aqueous solution, fluorine-containing compounds, etc., can also be used as catalysts.

[0071] Alkoxy oligomers can be commercially available. Examples of commercially available alkoxy oligomers include alkoxysilyl resins containing epoxy groups (Shin-Etsu Chemical Industry Co., Ltd.'s "X-41-1053" and "X-41-1059A"), alkoxysilyl resins containing methyl and epoxy groups (Shin-Etsu Chemical Industry Co., Ltd.'s "X-41-1056"), alkoxysilyl resins containing primary amino groups (Shin-Etsu Chemical Industry Co., Ltd.'s "X-40-2651"), and resins containing aminobenzene... Alkoxysilyl resins containing methyl groups ("X-40-9281" manufactured by Shin-Etsu Chemical Industry Co., Ltd.), alkoxysilyl resins containing mercapto groups ("X-40-1805" and "X-41-1818" manufactured by Shin-Etsu Chemical Industry Co., Ltd.), alkoxysilyl resins containing methyl and mercapto groups ("X-41-1810" manufactured by Shin-Etsu Chemical Industry Co., Ltd.), and alkoxysilyl resins containing methyl and amino groups ("X-40-2651" manufactured by Shin-Etsu Chemical Industry Co., Ltd.), etc.

[0072] Therefore, in one embodiment, the resin composition R comprises an inorganic filler material treated with an alkoxy-containing surface treatment agent. In a suitable embodiment, the alkoxy-containing surface treatment agent is one or more selected from alkoxy-containing silane coupling agents and their oligomers, more preferably a silane coupling agent or its oligomer having an alkoxy group and having one or more functional groups selected from amino, epoxy, and mercapto groups.

[0073] From the viewpoint of improving the dispersibility of inorganic filler materials and further enjoying the effects of the present invention, the degree of surface treatment using a surface treatment agent is preferably within a specified range. Specifically, it is preferred that 100 parts by weight of the inorganic filler material be surface treated with 0.2 to 5 parts by weight of a surface treatment agent, more preferably 0.2 to 3 parts by weight, and even more preferably 0.3 to 2 parts by weight.

[0074] The extent of surface treatment using surface treatment agents can be evaluated based on the carbon content per unit surface area of ​​the inorganic filler material. The preferred carbon content per unit surface area of ​​the inorganic filler material is 0.02 mg / m². 2 The above, more preferably 0.05 mg / m³ 2 The above is further preferred to be 0.1 mg / m³. 2 Above, 0.15mg / m 2 Above or 0.2 mg / m 2 The above. In particular, if the carbon content per unit surface area of ​​the inorganic filler material is 0.05 mg / m². 2Therefore, in the method for manufacturing the circuit board of the present invention, an insulating layer with a smaller surface roughness can be achieved, which is suitable. On the other hand, from the viewpoint of suppressing the increase in melt viscosity of the resin varnish and melt viscosity in sheet form, 1 mg / m³ is preferred. 2 The following is more preferably 0.8 mg / m³ 2 The following is a further preferred value: 0.5 mg / m³ 2 the following.

[0075] The carbon content per unit surface area of ​​the inorganic filler material can be measured by cleaning the surface-treated inorganic filler material with a solvent (e.g., methyl ethyl ketone (MEK)). Specifically, a sufficient amount of MEK is added to the surface-treated inorganic filler material, and ultrasonic cleaning is performed at 25°C for 5 minutes. After removing the supernatant and drying the solid components, the carbon content per unit surface area of ​​the inorganic filler material can be measured using a carbon analyzer. A carbon analyzer such as the "EMIA-320V" manufactured by Horiba Manufacturing Co., Ltd. can be used. In this invention, the carbon content per unit surface area of ​​the inorganic filler material is based on a value calculated according to the steps described in the section on <Determination / Calculation of Carbon Content per Unit Surface Area of ​​Inorganic Filler Material> described later.

[0076] From the viewpoint of easily achieving an insulating layer exhibiting better dielectric properties and a lower coefficient of thermal expansion, when the non-volatile component in the resin composition is set to 100% by mass, and the resin composition R contains inorganic filler, the content of inorganic filler in the resin composition (and the content of inorganic filler in the resin composition layer and the insulating layer) is, for example, 20% by mass or more, preferably 40% by mass or more. When the insulating layer contains inorganic filler, if the grinding speed is increased during chemical mechanical polishing of the insulating layer, there is a tendency for inorganic filler near the surface of the insulating layer to detach, surface sinking, etc., resulting in a larger surface roughness of the obtained insulating layer. In contrast, according to the circuit board manufacturing method of the present invention, even with a higher content of inorganic filler, a high grinding speed and a low surface roughness insulating layer can be achieved. For example, the content of inorganic filler in the resin composition can be increased to 50% by mass or more, 55% by mass or more, or 60% by mass or more. There is no particular upper limit to the content of this inorganic filler; for example, it can be set to 85% by mass or less, 80% by mass or less, etc.

[0077] -(d) Thermoplastic resin- The resin composition R may further comprise a thermoplastic resin. Examples of thermoplastic resins include phenoxy resins, polyvinyl acetal resins, polyolefin resins, polystyrene resins, polyimide resins, polyamide-imide resins, polyether-imide resins, polysulfone resins, polyethersulfone resins, polyphenylene ether resins, polyetheretherketone resins, and polyester resins. One thermoplastic resin may be used alone, or two or more may be used in combination.

[0078] The weight-average molecular weight (Mw) of the thermoplastic resin converted to polystyrene is preferably 8,000 or more, more preferably 10,000 or more, and even more preferably 20,000 or more or 30,000 or more. The upper limit is preferably 100,000 or less, more preferably 70,000 or less, and even more preferably 60,000 or less. The Mw of the thermoplastic resin converted to polystyrene is determined using the GPC method. Specifically, the Mw of the thermoplastic resin converted to polystyrene can be calculated as follows: using a Shimadzu LC-9A / RID-6A as the measuring apparatus, a Showa Denko Shodex K-800P / K-804L / K-804L as the column, chloroform or the like as the mobile phase, the measurement is performed at a column temperature of 40°C, and the result is calculated using a standard curve of standard polystyrene.

[0079] Examples of phenoxy resins include those having one or more skeletons selected from the following: bisphenol A skeleton, bisphenol F skeleton, bisphenol S skeleton, bisphenol acetophenone skeleton, phenolic varnish skeleton, biphenyl skeleton, fluorene skeleton, dicyclopentadiene skeleton, norbornene skeleton, naphthalene skeleton, anthracene skeleton, adamantane skeleton, terpene skeleton, and trimethylcyclohexane skeleton. The terminal group of the phenoxy resin can be any functional group such as phenolic hydroxyl group or epoxy group. A single phenoxy resin can be used alone, or two or more can be used in combination. Specific examples of phenoxy resins include Mitsubishi Chemical's "1256" and "4250" (both phenoxy resins containing a bisphenol A backbone), "YX8100" (a phenoxy resin containing a bisphenol S backbone), and "YX6954" (a phenoxy resin containing a bisphenol acetophenone backbone). Other examples include Nippon Steel Chemicals & Materials' "FX280" and "FX293," and Mitsubishi Chemical's "YL7800BH40," "YL7500BH30," "YX6954BH30," "YX7553," "YX7553BH30," "YL7769BH30," "YL6794," "YL7213," "YL7290," and "YL7482," etc.

[0080] Examples of polyvinyl alcohol acetal resins include polyvinyl alcohol formal resin and polyvinyl alcohol butyral resin, with polyvinyl alcohol butyral resin being preferred. Specific examples of polyvinyl alcohol acetal resins include "Denka Butyral 4000-2", "Denka Butyral 5000-A", "Denka Butyral 6000-C", and "Denka Butyral 6000-EP" manufactured by DENKA Corporation, and the S-LEC BH series, BX series (e.g., BX-5Z), KS series (e.g., KS-1), BL series, and BM series manufactured by Sekisui Chemicals Co., Ltd.

[0081] As a polyimide resin, a resin having an imide structure (preferably a cyclic imide structure) can be used. For example, an imide compound of an anhydride and a diamine compound or a diisocyanate compound can be used. Specific examples of polyimide resins include "RIKACOAT SN20" and "RIKACOAT PN20" manufactured by Shin Nippon Rikka Co., Ltd. Specific examples of polyimide resins also include linear polyimides (the polyimide described in Japanese Patent Application Publication No. 2006-37083) obtained by reacting difunctional hydroxyl-terminated polybutadiene, a diisocyanate compound, and a tetrabasic anhydride, and modified polyimides such as those containing a polysiloxane backbone (the polyimides described in Japanese Patent Application Publication Nos. 2002-12667 and 2000-319386, etc.).

[0082] Specific examples of polyamide-imide resins include "VYLOMAX HR11NN" and "VYLOMAX HR16NN" manufactured by Toyobo Co., Ltd. Other examples of polyamide-imide resins include modified polyamide-imides such as "KS9100" and "KS9300" (polyamide-imide containing a polysiloxane backbone) manufactured by Resonac Co., Ltd.

[0083] Specific examples of polyethersulfone resins include "PES5003P" manufactured by Sumitomo Chemical Co., Ltd. Specific examples of polyphenylene ether resins include "OPE-2St 1200" of low-polyphenylene ether-styrene resin manufactured by Mitsubishi Gas Chemical Co., Ltd. Specific examples of polyetheretherketone resins include "SUMIPLOY K" manufactured by Sumitomo Chemical Co., Ltd. Specific examples of polyetherimide resins include "ULTEM" manufactured by GE.

[0084] Specific examples of polysulfone resins include polysulfones such as "P1700" and "P3500" manufactured by Solvay Advanced Polymers.

[0085] Examples of polyolefin resins include, for example, low-density polyethylene, ultra-low-density polyethylene, high-density polyethylene, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, ethylene-methyl acrylate copolymer, and other ethylene-based copolymer resins; and polyolefin elastomers such as polypropylene and ethylene-propylene block copolymers.

[0086] Examples of polystyrene resins include homopolymers of styrene, copolymers of styrene with diene compounds (butadiene, isoprene, etc.) and their hydrogenated forms.

[0087] Examples of polyester resins include polyethylene terephthalate resin, polyethylene naphthalate resin, polybutylene terephthalate resin, polybutylene naphthalate resin, 1,3-propanediol terephthalate resin, 1,3-propanediol naphthalate resin, and polycyclohexanediol terephthalate resin.

[0088] When the resin composition R contains a thermoplastic resin, and the resin content in the resin composition is set to 100% by mass, the content of the thermoplastic resin is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, and even more preferably 0.5% by mass or more. The upper limit is preferably 20% by mass or less, more preferably 15% by mass or less, and even more preferably 10% by mass or less.

[0089] -(e) Curing accelerator- The resin composition R may also contain a curing accelerator. Examples of curing accelerators include amine-based curing accelerators, imidazole-based curing accelerators, guanidine-based curing accelerators, metal-based curing accelerators, and peroxide-based curing accelerators. A single curing accelerator may be used alone, or two or more may be used in combination.

[0090] When the resin composition R contains a curing accelerator, the content of the curing accelerator in the resin composition can be determined according to the required characteristics of the resin composition. When the resin component in the resin composition is set to 100% by mass, it is preferably 5% by mass or less, more preferably 4% by mass or less, and even more preferably 3% by mass or less. The lower limit can be set to 0.01% by mass or more, 0.05% by mass or more, 0.1% by mass or more, etc.

[0091] The resin composition R may also contain other additives. Examples of such additives include, for instance, organic fillers such as rubber particles; photocationic polymerization initiators and photoacid generators such as sulfonium salts, iodonium salts, and nonionic compounds; photosensitizers such as naphthoquinone didiazo compounds; free radical polymerization initiators such as peroxide-based and azo-based free radical polymerization initiators; organometallic compounds such as organocopper compounds, organozinc compounds, and organocobalt compounds; colorants such as phthalocyanine blue, phthalocyanine green, iodine green, diazo yellow, crystal violet, titanium dioxide, and carbon black; polymerization inhibitors such as hydroquinone, catechol, pyrogallol, and phenothiazine; leveling agents such as silicone-based and acrylic polymer-based leveling agents; thickeners such as BENTON and montmorillonite; defoamers such as silicone-based, acrylic-based, fluorinated, and vinyl resin-based defoamers; ultraviolet absorbers such as benzotriazole-based ultraviolet absorbers; and adhesion improvers such as ureasilanes. The additives include: triazole-based, tetraazole-based, and triazine-based binding agents; hindered phenolic antioxidants; diphenylethylene derivatives and other fluorescent whitening agents; fluorinated surfactants and organosilicon surfactants; phosphorus-based flame retardants (e.g., phosphate compounds, phosphazene compounds, phosphonic acid compounds, red phosphorus), nitrogen-based flame retardants (e.g., melamine sulfate), halogen-based flame retardants, and inorganic flame retardants (e.g., antimony trioxide); phosphate-based dispersants, polyoxyalkylene-based dispersants, acetylene-based dispersants, organosilicon dispersants, anionic dispersants, and cationic dispersants; and borate ester / salt stabilizers, titanate ester / salt stabilizers, aluminate ester / salt stabilizers, zirconate ester / salt stabilizers, isocyanate stabilizers, carboxylic acid stabilizers, and carboxylic anhydride stabilizers. The content of these additives can be determined according to the required properties of the resin composition.

[0092] There is no particular limitation on the preparation method of the resin composition R. Examples include, for instance, using a rotary stirrer to mix / disperse the components together with a solvent as required.

[0093] From the viewpoint of achieving an insulating layer exhibiting good mechanical properties, heat resistance, and excellent reliability, the glass transition temperature (Tg2) of the cured product obtained by curing resin composition R at 200°C for 120 minutes is preferably 140°C or higher, more preferably 145°C or higher, or 150°C or higher. There is no particular upper limit to Tg2, and it can typically be set to 250°C or lower, 240°C or lower, etc.

[0094] Hereinafter, the present invention will be described in detail according to its suitable embodiments. The present invention is not limited to the following description, and the constituent elements may be appropriately modified without departing from the spirit of the present invention.

[0095] [Manufacturing method of circuit board] The method for manufacturing the circuit board of the present invention (hereinafter also referred to as "the method of the present invention") includes the following steps (X), (Y) and (Z).

[0096] (X) A process of forming a resin composition layer by embedding the conductor post on a substrate on which an interlayer connection conductor post is provided on the surface, and curing the resin composition layer to form an insulating layer. (Y) The process of exposing the conductor pillar by grinding the insulating layer through chemical mechanical polishing (CMP); (Z) The process of forming a seed layer on the surface of the insulating layer.

[0097] Furthermore, the method for manufacturing the circuit board of the present invention is characterized in that, when the glass transition temperature (°C) of the cured product obtained by curing the resin composition R using the curing conditions in step (X) is set as Tg1, and the glass transition temperature (°C) of the cured product obtained by curing the resin composition R at 200°C for 120 minutes is set as Tg2, step (X) is performed in such a way that 0.5≤Tg1 / Tg2≤0.9 is satisfied.

[0098] As mentioned above, with the increasing performance of electronic devices, there is a growing demand for finer wiring in circuit boards used in semiconductor packaging. This necessitates the use of chemical mechanical polishing (CMP) to polish the insulating layer and form a conductive layer on the polished surface of the resulting insulating layer to manufacture the circuit board. This is because the surface of the insulating layer after CMP is flat and smooth, which facilitates the miniaturization of the conductive layer formed thereon.

[0099] On the other hand, from the perspective of improving the productivity of semiconductor packaging, high-speed processing is being pursued in various production processes, including chemical mechanical polishing (CMP) of insulating layers. Regarding this, when performing CMP on insulating layers, increasing the polishing speed by adjusting polishing conditions (rotation speed, pressure, type and concentration of polishing compound) increases the surface roughness of the resulting insulating layer, diminishing the advantages of CMP. Furthermore, it has been found that insulating layers used in circuit boards sometimes contain inorganic filler materials such as silicon dioxide to achieve characteristics such as low thermal expansion and low dielectric loss tangent. However, in such cases, the aforementioned problems become more pronounced. Specifically, it has been found that when performing CMP on insulating layers containing inorganic filler materials, increasing the polishing speed causes the inorganic filler material near the surface of the insulating layer to detach, resulting in surface depression and increased surface roughness of the resulting insulating layer.

[0100] In contrast, according to the method of the present invention that performs step (X) in such a manner as satisfying 0.5≤Tg1 / Tg2≤0.9, a high polishing speed and a low surface roughness can be achieved when performing chemical mechanical polishing on the insulating layer. Therefore, the present invention significantly contributes to the micro-wiring of circuit boards and the improvement of the productivity of circuit boards with micro-wiring.

[0101] <Process (X)> In process (X), a resin composition layer is formed on a substrate on which interlayer conductor pillars are provided on the surface, by means of embedding the conductor pillars, and the resin composition layer is cured to form an insulating layer.

[0102] -A substrate with conductor pillars for interlayer bonding on its surface- As the substrate used in process (X) with interlayer conductor pillars provided on its surface, any substrate used for manufacturing circuit boards can be used as long as interlayer conductor pillars are provided on its surface.

[0103] Examples of substrates that serve as the base material include glass epoxy boards, polyester substrates, polyimide substrates, BT resin substrates, and thermosetting polyphenylene ether substrates, which are commonly used as core materials in the manufacture of circuit boards. These substrates may have conductor layers on one or both sides, and these conductor layers may be patterned.

[0104] As the base material, any substrate selected from metal substrates, inorganic substrates and organic substrates can be used. Substrates with metal layers on the surface of these substrates that function as a seed layer for plating when forming conductor pillars can also be used.

[0105] Regarding metal substrates, examples of their constituent materials (metallic materials) include copper, aluminum, and their alloys with other metals (such as tin, chromium, silver, magnesium, nickel, zirconium, silicon, titanium, etc.).

[0106] Examples of inorganic substrates include glass substrates, ceramic substrates, and semiconductor wafers. Examples of organic substrates include substrates containing plastic materials. There are no particular limitations on the materials used for glass substrates; various glass materials such as borosilicate glass, quartz glass, lead glass, and soda-lime glass can be used. There are no particular limitations on the materials used for ceramic substrates; various ceramic materials such as alumina and zirconium oxide can be used. Silicon (Si) based wafers are suitable examples of semiconductor wafers, but they are not limited to these; examples include wafers based on gallium arsenide (GaAs), indium phosphide (InP), gallium phosphide (GaP), gallium nitride (GaN), gallium tellurium (GaTe), zinc selenide (ZnSe), and silicon carbide (SiC). In addition, examples of plastic materials include polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN); acrylics such as polycarbonate (PC) and polymethyl methacrylate (PMMA); cyclic polyolefins, cellulose triacetate (TAC), polysulfide (PES), polyetherketone, and polyimide. Composite materials such as fiber-reinforced plastics can also be used.

[0107] When using a substrate with a metal layer disposed on the surface of these substrates, the metal material constituting the metal layer is not particularly limited as long as it can form a conductive layer on the surface of the metal layer. Examples include copper, palladium, gold, platinum, silver, aluminum, and alloys thereof with other metals (such as tin, chromium, magnesium, nickel, zirconium, silicon, titanium, etc.). The metal layer can be formed on the substrate by methods such as sputtering, electroless plating, or bonding of extremely thin metal foils.

[0108] As described above, the substrate has interlayer connecting conductor pillars on its surface. In addition to having interlayer connecting conductor pillars, the substrate may also have other conductive circuits on its surface.

[0109] The conductor material used in the conductor circuit, with the conductor pillar as the primary component, is not particularly limited. In a suitable embodiment, the conductor circuit comprises one or more metals selected from gold, platinum, palladium, silver, copper, aluminum, cobalt, chromium, zinc, nickel, titanium, tungsten, iron, tin, and indium. The conductor circuit may comprise a single metal or an alloy. Examples of alloys include alloys of two or more metals selected from the above group (e.g., nickel-chromium alloys, copper-nickel alloys, and copper-titanium alloys). From the viewpoint of versatility and cost in forming the conductor circuit, single metals of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver, or copper, or alloys of nickel-chromium, copper-nickel, or copper-titanium alloys, are preferred. More preferably, single metals of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver, or copper, or alloys of nickel-chromium alloys, are preferred. Even more preferably, single metals of copper are preferred.

[0110] The conductor circuit, with the conductor pillar as its core, can be a single-layer structure or a multi-layer structure consisting of two or more layers of single metal layers or alloy layers containing different types of metals or alloys. In the case of a multi-layer conductor circuit, 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.

[0111] Conductor circuits, beginning with these interlayer interconnect conductor pillars, can be formed on the surface of a substrate using known methods. The following illustrates an example of a method for forming conductor circuits, beginning with interlayer interconnect conductor pillars, on the surface of a substrate.

[0112] Forming a conductor circuit on the surface of a substrate can be carried out using known circuit formation methods such as the semi-additive method and the fully additive method.

[0113] In one embodiment, the circuit formation method includes: (A-1) A seed layer is formed on the surface of a substrate, a photoresist is applied to the seed layer, and the photoresist is exposed / developed to expose the seed layer in correspondence with the circuit pattern of the conductor circuit to be formed; and (A-2) A conductor layer is formed on the exposed plated seed layer to form a conductor circuit.

[0114] In (A-1) above, the seed layer can be formed in the same way as in the subsequent step (Z). It should be noted that when using a substrate with a metal layer as the substrate, the metal layer can be used as the seed layer. Therefore, (A-1) above can be replaced with "applying a photoresist to the metal layer of the substrate with the metal layer, exposing / developing the photoresist to expose the seed layer corresponding to the circuit pattern of the conductor circuit to be formed", and (A-2) above can be replaced with "forming a conductor layer on the exposed metal layer to form a conductor circuit".

[0115] As a photoresist, any known material capable of developing a desired conductor circuit pattern can be used, including either film-type photoresist (dry film photoresist) or liquid photoresist.

[0116] From the viewpoint that conductor circuits can be formed using fine patterns, the formation of conductor circuits is preferably carried out using a semi-additive method. Therefore, in (A-2) above, the conductor layer is preferably formed on the exposed plating seed layer using an electrolytic plating method.

[0117] By performing multiple formations of a conductor layer using photoresist, desired circuit patterns and interlayer connection patterns can be formed. For example, using a first photoresist to perform steps (A-1) and (A-2) above, a conductor circuit is formed. Then, a second photoresist is applied to the substrate on which the conductor circuit is located, and the photoresist is exposed / developed to expose the conductor layer corresponding to the interlayer connection pattern. Next, a conductor layer is further applied to the exposed conductor circuit to form conductor pillars for interlayer connections. After forming the conductor pillars for interlayer connections, the second photoresist can be removed.

[0118] When using a substrate that functions as a component of a circuit board, such as a core material, as the substrate, after forming the conductor circuit, starting with the interlayer interconnect conductor pillars, the plating seed layer for the unformed portion of the circuit is removed. This allows for the obtaining of a substrate with interlayer interconnect conductor pillars on its surface. Alternatively, when using a substrate with a metal layer or a simulated substrate that is removed in a subsequent process, it is not necessary to remove the plating seed layer for the unformed portion of the circuit. When using a simulated substrate as the substrate, in a subsequent process of circuit board manufacturing, it is sufficient to remove the simulated substrate to expose the conductor circuit, starting with the conductor pillars.

[0119] The dimensions of conductor circuits, primarily the conductor pillars for interlayer connections, can be determined based on the desired design of the circuit board. For example, from the viewpoint of thinning the circuit board, the height of the conductor pillars for interlayer connections (the dimension of the conductor pillar in the thickness direction of the circuit board) can be set to 30μm or less, 25μm or less, 20μm or less, 15μm or less, 10μm or less, etc. There is no particular limitation on the lower limit; it can typically be set to 1μm or more, 2μm or more, 3μm or more, etc. Furthermore, from the viewpoint of fine wiring, the minimum line-to-spacing ratio (L / S) of the conductor circuit can be set to 5 / 5μm or less, 3 / 3μm or less, 2 / 2μm or less, 1.5 / 1.5μm or less, or 1 / 1μm or less, etc.

[0120] -Resin Composition Layer- A resin composition layer is formed using resin composition R by embedding a conductor post. The resin composition R is as described in the <Resin Composition> section above.

[0121] Process (X) can be carried out by coating the above-mentioned resin composition R in a varnish state, or by pre-forming a resin composition layer containing the resin composition R and then stacking the resin composition layer.

[0122] In a suitable embodiment, step (X) includes: laminating a resin sheet comprising a support and a resin composition layer disposed on the support onto a substrate in such a manner that the resin composition layer is bonded to a conductor post.

[0123] Examples of supports include films containing plastic materials, metal foils, and release papers, with films and metal foils containing plastic materials being preferred. When using a film containing plastic materials as the support film, examples of plastic materials include polyesters such as PET and PEN; acrylics such as PC and PMMA; cyclic polyolefins, TAC, PES, polyetherketones, and polyimides. When using a metal foil as the support, examples of metal foils include copper foil and aluminum foil, with copper foil being preferred. Copper foil can be used as the copper foil, either as a foil containing elemental copper or as an alloy of copper with other metals (e.g., tin, chromium, silver, magnesium, nickel, zirconium, silicon, titanium, etc.). The surface of the support that bonds to the resin composition layer can be roughened, corona-treated, or treated with antistatic agents. Furthermore, a support with a release layer on the surface that bonds to the resin composition layer can be used as the support. Release agents used in the release layer of a support with a release layer can be categorized as, for example, one or more release agents selected from alkyd resins, olefin resins, urethane resins, and silicone resins. Commercially available release agents include, for example, "SK-1," "AL-5," and "AL-7" manufactured by LINTEC Corporation, which belong to the alkyd resin-based release agent category.

[0124] The thickness of the support is not particularly limited, but is preferably in the range of 5μm to 75μm, and more preferably in the range of 10μm to 60μm. It should be noted that when the support is a support with a release layer, the overall thickness of the support with the release layer is preferably within the above range.

[0125] The resin sheet can be prepared by, for example, coating the resin composition R itself, or a resin varnish prepared by dissolving the resin composition R in an organic solvent, onto a support film using a die coater or the like, and then drying it to form a resin composition layer.

[0126] In resin sheets, the thickness of the resin composition layer is not particularly limited as long as it can embed the interlayer conductor pillars, and can be appropriately determined according to the specific design. From the viewpoint of circuit board thinning and circuit board productivity, it can be set to less than 40μm, less than 30μm, less than 25μm, less than 20μm, less than 15μm, less than 10μm, etc. The lower limit is not particularly limited, and can usually be set to more than 1μm, more than 2μm, more than 3μm, etc.

[0127] The resin sheet may further include other layers as needed. Examples of such other layers include, for instance, a protective film similar to the support, provided on the side of the resin composition layer that is not bonded to the support (i.e., the side opposite to the support). The thickness of the protective film is not particularly limited, but is, for example, 1 to 40 μm. By laminating the protective film, it is possible to inhibit the adhesion and damage of contaminants and the like to the surface of the resin composition layer. When the resin sheet has a protective film, it can be used by peeling off the protective film.

[0128] The lamination of resin sheets is not particularly limited as long as the resin composition layers can be laminated in a manner that embeds conductor pillars. For example, it can be performed by heating and pressing the resin sheet onto the substrate from the support side. Examples of components for heating and pressing the resin sheet onto the substrate (hereinafter also referred to as "heat-pressing components") include heated metal plates (such as SUS mirror plates) or metal rollers (SUS rollers). It should be noted that it is preferable to apply pressure through an elastic material such as heat-resistant rubber so that the resin sheet fully follows the surface irregularities of the substrate based on the conductor circuit with conductor pillars, rather than directly pressing the heat-pressing component onto the resin sheet.

[0129] The lamination of resin sheets can be performed using vacuum lamination. In vacuum lamination, the heating and pressing temperature is preferably in the range of 60°C to 160°C, more preferably in the range of 80°C to 140°C; the heating and pressing pressure is preferably in the range of 0.098 MPa to 1.77 MPa, more preferably in the range of 0.29 MPa to 1.47 MPa; and the heating and pressing time is preferably in the range of 20 seconds to 400 seconds, more preferably in the range of 30 seconds to 300 seconds. Lamination is preferably performed under reduced pressure conditions of 26.7 hPa or less. Lamination can be performed using a vacuum laminator. Examples of commercially available vacuum laminators include, for instance, the vacuum pressure laminator manufactured by Meiki Seisakusho Co., Ltd., the vacuum applicator manufactured by Nikko Materials Co., Ltd., and intermittent vacuum pressure laminators.

[0130] After lamination, the laminated resin sheets can be smoothed by applying pressure to the heated pressing members under normal pressure (atmospheric pressure), for example, from the support side. The pressure conditions for smoothing can be set to the same conditions as the heated pressing conditions for lamination described above. Lamination and smoothing can be performed continuously using a vacuum laminator.

[0131] -Curing of the resin composition layer (formation of the insulating layer)- The resin composition layer is cured to form an insulating layer. Thus, the insulating layer is formed in a manner that embeds the conductor circuit, with the conductor pillars at the top.

[0132] From the viewpoint of achieving a high grinding speed and an insulating layer with low surface roughness, when the glass transition temperature (°C) of the cured product obtained by curing the resin composition R using the curing conditions in step (X) is set as Tg1, and the glass transition temperature (°C) of the cured product obtained by curing the resin composition R at 200°C for 120 minutes is set as Tg2, it is necessary to implement step (X) in such a way that 0.5≤Tg1 / Tg2≤0.9 is satisfied.

[0133] From the viewpoint of achieving higher grinding speed and achieving an insulating layer with lower surface roughness, it is suitable to carry out step (X) in such a way that the Tg1 / Tg2 ratio is preferably 0.55 or more, more preferably 0.6 or more, even more preferably 0.62 or more or 0.64 or more, and preferably 0.85 or less, more preferably 0.8 or less.

[0134] In this invention, the glass transition temperatures Tg1 and Tg2 of the resin composition R are based on the following values: as described in the section on "Determination of Glass Transition Temperature of Resin Composition" below, the cured resin composition R is measured using a dynamic mechanical analysis apparatus (DMA) at a heating rate of 2°C / min within the range of 25°C to 240°C, and the value is obtained by rounding the first decimal place of the temperature at which the loss tangent (tanδ) calculated based on the ratio of the obtained storage modulus (E') to the loss modulus (E') reaches its maximum value.

[0135] The curing conditions in process (X) can be determined in such a way that the Tg1 / Tg2 ratio described above satisfies the scope of the present invention, and also vary depending on the composition of the resin composition R, etc. For example, the curing temperature can be determined in the range of 100°C to 220°C, more preferably in the range of 120°C to 200°C, and the curing time can be determined in the range of 5 minutes to 240 minutes, more preferably in the range of 10 minutes to 150 minutes.

[0136] The curing of the resin composition layer in step (X) can be carried out by a single-stage heat treatment or by two or more stages of heat treatment. When using two or more stages of heat treatment, the temperature in the first stage of heat treatment is preferably lower than the temperature in the second and subsequent stages of heat treatment.

[0137] When using resin sheets to form a resin composition layer (insulating layer), the support can be removed either before or after the resin composition layer has cured. From the viewpoint of achieving higher grinding speeds and an insulating layer with lower surface roughness, it is preferable to remove the support after the resin composition layer has cured.

[0138] <Process (Y)> In process (Y), the conductor pillars are exposed by grinding the insulating layer through chemical mechanical polishing (CMP).

[0139] In chemical mechanical polishing (CMP), an abrasive slurry is used to polish the surface of an insulating layer.

[0140] As an abrasive (grinding agent) included in the grinding slurry as a dispersed phase, any known abrasive can be used as long as it can grind the cured product of the resin composition R, i.e., the insulating layer. Examples of abrasive materials include inorganic particles such as silica, alumina, cerium oxide, titanium dioxide, and chromium oxide; and organic particles such as diamond and hard resin particles. A single abrasive can be used, or two or more can be used in combination.

[0141] From the viewpoint of easily obtaining an insulating layer with low surface roughness, a small average particle size of the abrasive is desirable. When the resin composition R contains an inorganic filler, it is suitable to use an abrasive with an average particle size smaller than that of the inorganic filler. The average particle size of the abrasive can be, for example, set to 1 μm or less, 0.5 μm or less, 0.4 μm or less, 0.2 μm or less, etc. There is no particular limitation on the lower limit of this average particle size; it can typically be set to 0.005 μm or more, 0.01 μm or more, etc.

[0142] The concentration of abrasive in the grinding slurry is not particularly limited, but can be determined in the range of 0.01 to 30% by mass (preferably 0.1 to 25% by mass).

[0143] Furthermore, from the viewpoint of the dispersibility of the abrasive, the grinding slurry may also contain a dispersant. As a dispersant, any existing and known dispersant used in chemical mechanical grinding grinding slurries can be used. Examples of such dispersants include various surfactants such as ionic surfactants and nonionic surfactants; and acids such as hydrochloric acid and nitric acid. From the viewpoint of achieving good dispersibility of the abrasive, the concentration of the dispersant in the grinding slurry is appropriately determined based on its relationship with the concentration of the abrasive.

[0144] Provided that the effects of the present invention are not compromised, the grinding slurry may further contain other components, such as pH adjusters, thickeners, oxidants, and corrosion inhibitors. The concentration of these other components in the grinding slurry may be appropriately determined according to the desired purpose.

[0145] Water can be used as a dispersion medium for grinding slurries.

[0146] The grinding speed of the insulating layer can be adjusted by selecting / changing the hardness, average particle size, and concentration of the abrasive in the grinding slurry. For example, there is a tendency that the higher the hardness of the abrasive, the larger the average particle size of the abrasive, and the higher the concentration of the abrasive in the grinding slurry, the higher the grinding speed of the insulating layer.

[0147] In chemical mechanical polishing (CMP), the polishing pressure (the pressure exerted between the substrate carrier and the polishing pad) can be appropriately determined based on the composition of the insulating layer to achieve the desired polishing speed. Furthermore, the rotational speed of the substrate carrier and the rotational speed of the polishing platform holding the polishing pad can also be appropriately determined based on the composition of the insulating layer to achieve the desired polishing speed. There is a tendency that the higher the polishing pressure and the higher the rotational speed of the carrier and polishing platform, the higher the polishing speed of the insulating layer.

[0148] As described above, when further miniaturizing the wiring of a circuit board, it is desirable to use the following technique: to polish the insulating layer using chemical mechanical polishing (CMP) and form a conductor layer on the polished surface of the resulting insulating layer to manufacture the circuit board. This can be considered because the surface of the insulating layer after chemical mechanical polishing is flat and smooth, which facilitates the miniaturization of the conductor layer formed thereon.

[0149] However, when performing chemical mechanical polishing on the insulating layer, adjusting the polishing conditions (rotation speed, pressure, type and concentration of abrasive) to increase the polishing speed results in a larger surface roughness of the resulting insulating layer, thus diminishing the advantages of chemical mechanical polishing. This problem is particularly pronounced when the insulating layer contains inorganic fillers.

[0150] In contrast, the method of the present invention, which performs step (X) in such a way as to satisfy 0.5≤Tg1 / Tg2≤0.9, can achieve an insulating layer with low surface roughness and a high grinding speed. The grinding speed of the insulating layer in step (Y) can be set to 1 μm / min or more, and further, it can be increased to 1.2 μm / min or more, 1.4 μm / min or more, 1.5 μm / min or more, or 1.6 μm / min or more.

[0151] In process (Y), the amount (thickness) of the insulating layer being ground is determined based on the difference between the height of the conductor post and the thickness of the insulating layer. From the viewpoint of achieving a flat insulating layer with low surface roughness, it is preferably 1 μm or more, more preferably 2 μm or more or 3 μm or more. The upper limit of this grinding amount varies depending on the grinding thickness required to expose the conductor post. From the viewpoint of shortening the time consumed in process (Y) and thus improving the productivity of the circuit board, it is preferably set to 20 μm or less, 15 μm or less, 10 μm or less, etc.

[0152] As described above, according to the method of the present invention, an insulating layer with low surface roughness can be formed by chemical mechanical polishing. In one embodiment, the arithmetic mean roughness Ra of the surface (polished surface) of the insulating layer obtained by step (Y) is preferably 70 nm or less, more preferably 50 nm or less, and even more preferably 40 nm or less, 35 nm or less, or 30 nm or less. The lower limit of this arithmetic mean roughness Ra is not particularly limited, and for example, it can be 1 nm or more, 2 nm or more, 3 nm or more, etc.

[0153] Chemical mechanical polishing (CMP) of the insulating layer can be performed using commercially available CMP apparatus. Examples of commercially available CMP apparatus include the "LaboForce-100" apparatus manufactured by Struers.

[0154] <Process (Z)> In process (Z), a seed layer is formed on the surface of the insulating layer.

[0155] The thickness of the seed layer is preferably 500 nm or less, more preferably 400 nm or less, and even more preferably 300 nm or less. Regarding the seed layer, after a conductor layer with a desired pattern is formed on it, unwanted portions other than the conductor layer formation area are removed by etching or the like. At this time, the smaller the thickness of the seed layer, the easier it is to remove the unwanted portions, and the erosion of the conductor pattern during removal can be minimized. Therefore, this is advantageous in achieving micro-wiring.

[0156] Regarding this point, if a thin seed layer is formed on the surface of the insulating layer, there is a tendency for a phenomenon known as plating ablation, where the thickness of the conductor layer formed on the seed layer by electroplating deviates. This can be presumed to be because the unevenness of the insulating layer surface easily leads to non-uniformity in the thickness of the seed layer. Specifically, the resistance of the thinner portions of the seed layer is higher than that of the thicker portions. If an electroplating method is used to form the conductor layer on these thinner, higher-resistance portions, the plating growth is slower compared to other portions, resulting in insufficient conductor layer formation and difficulty in forming a uniform conductor layer.

[0157] In contrast, according to the method of the present invention, as described above, an insulating layer with low surface roughness can be formed by chemical mechanical polishing, and even if the thickness of the seed layer is further reduced, coating ablation can be suppressed. For example, the thickness of the seed layer can be reduced to below 280 nm, below 260 nm, or below 250 nm.

[0158] The plating seed layer includes at least a conductive seed layer. The conductive seed layer functions as an electrode through an electrolytic plating process. The conductive material constituting the conductive seed layer is not particularly limited as long as it exhibits sufficient conductivity; suitable examples include copper, palladium, gold, platinum, silver, aluminum, and their alloys. Additionally, the plating seed layer may include a diffusion barrier layer. The diffusion barrier layer prevents the conductive material constituting the conductive seed layer from diffusing into the insulating layer, thus preventing insulation breakdown. Furthermore, the material constituting the diffusion barrier layer is not particularly limited as long as it can suppress / prevent the diffusion of the conductive material constituting the conductive seed layer; suitable examples include titanium, tungsten, tantalum, and their alloys. When the plating seed layer includes a diffusion barrier layer, the "thickness of the plating seed layer" in this invention refers to the average thickness of the entire plating seed layer, including not only the conductive seed layer but also the diffusion barrier layer.

[0159] When the seed layer includes a diffusion barrier layer, the thickness of the diffusion barrier layer is not particularly limited as long as it can suppress / prevent the diffusion of the conductive material constituting the conductive seed layer. From the viewpoint of facilitating microwiring, it is preferably 50 nm or less, more preferably 40 nm or less, and even more preferably 30 nm or less. The lower limit of the thickness of the diffusion barrier layer is not particularly limited; for example, it can be set to 1 nm or more, 3 nm or more, 5 nm or more, etc. In this case, the allowance for the seed layer is preferably a conductive seed layer, and the thickness of this conductive seed layer can be determined in such a way that the overall thickness of the seed layer falls within the aforementioned suitable range, based on its correlation with the thickness of the diffusion barrier layer.

[0160] The seed layer can be formed by either dry plating or wet plating. Examples of dry plating include physical vapor deposition (PVD) methods such as sputtering, ion plating, and vacuum evaporation; and chemical vapor deposition (CVD) methods such as thermal CVD and plasma CVD. Examples of wet plating include electroless plating. From the viewpoint of easily forming a thin seed layer with a more uniform thickness, sputtering or electroless plating is preferred, and sputtering is particularly preferred from the viewpoint of achieving micro-wires with excellent adhesion strength. Therefore, in a suitable embodiment, the seed layer is formed by sputtering in step (Z).

[0161] After step (Z), a conductor layer can be formed on the seed layer by electroplating. Therefore, in one embodiment, the method of the present invention includes the step of forming a conductor layer on the seed layer by electroplating.

[0162] The conductor material used in the conductor layer is not particularly limited, and it is suitable for, for example, the description of the conductor circuit with conductor pillars as the main conductor in relation to process (X).

[0163] The formation of the conductor layer can be carried out using a so-called semi-additive method. That is, a photoresist (plating resist) is formed on the plating seed layer formed in process (Z) to expose a portion of the plating seed layer corresponding to the desired wiring pattern. Next, after forming the conductor layer on the exposed plating seed layer by electroplating, the photoresist is removed. Here, as described above in relation to process (X), multiple conductor layer formations can be performed using the photoresist to form the desired circuit pattern and interlayer connection pattern (conductor pillars, etc.). Subsequently, unwanted plating seed layer portions other than the conductor layer formation portion can be removed by etching or the like to form a conductor layer (conductor circuit) with the desired wiring pattern.

[0164] According to the method of the present invention, it is possible to suppress coating ablation and to form conductor circuits with L / S values ​​of, for example, 5 / 5 μm or less, 4 / 4 μm or less, 3 / 3 μm or less, 2 / 2 μm or less, 1.5 / 1.5 μm or less, or 1 / 1 μm or less.

[0165] Furthermore, by forming an insulating layer, chemically and mechanically polishing the insulating layer, and forming conductive circuits, a multilayer circuit board can be manufactured. It should be noted that during the manufacture of the circuit board, after chemically and mechanically polishing the insulating layer, an additional heat treatment (additional curing) can be applied. This additional heat treatment can be performed under conditions appropriately determined based on the composition of the resin composition R, etc., to achieve complete curing of the curable resin. The additional heat treatment can be performed during the formation of each conductive circuit layer, or it can be performed on the multiple insulating layers together after the formation of multiple conductive circuits.

[0166] In addition, in process (X), when a simulated substrate such as a substrate with a metal layer is used as the substrate, depending on the type of metal layer and substrate used, the metal layer and substrate can be removed at the same time, or the insulating layer formed in process (X) can be exposed by removing the substrate and then removing the metal layer, thereby obtaining a circuit board with exposed conductor circuits, starting with conductor pillars.

[0167] As described above, the circuit board manufactured by the method of the present invention can be suitably used as a circuit board for semiconductor packaging (semiconductor packaging circuit board). Semiconductor packages using the circuit board manufactured by the method of the present invention can be either fan-in or fan-out packages. In the case of a fan-out package, it is advantageous to form conductor circuits with a large area and fine patterns, complementing the original advantages of fan-out packages that can form redistribution layers over a large area. Therefore, in a suitable embodiment, the circuit board manufactured by the method of the present invention is a circuit board for fan-out packages. The circuit board manufactured by the method of the present invention can be widely used as a circuit board for constituting semiconductor packages, for example, as an interposer for multi-chip packages. For example, an analog substrate such as a substrate with a metal layer can be used as a substrate to manufacture the interposer alone, or a semiconductor packaging core circuit board can be used as a substrate to manufacture an interposer / core circuit board configuration.

[0168] In semiconductor packaging manufacturing, one main surface of a circuit board is electrically connected to a semiconductor chip. Furthermore, board connection terminals such as bumps can be formed on the other main surface of the circuit board and mounted on a printed circuit board. Alternatively, after electrically connecting the other main surface of the circuit board to a core circuit board for semiconductor packaging, board connection terminals such as bumps can be formed on the board connection side of the core circuit board and mounted on a printed circuit board. Example

[0169] The present invention will be specifically described below through examples. The present invention is not limited to these examples. It should be noted that, unless otherwise specified, the terms "parts" and "%" to indicate quantity refer to "parts by mass" and "% by mass," respectively. In particular, the temperature and pressure conditions, when no temperature is specified, are room temperature (25°C) and atmospheric pressure (1 atm).

[0170] <Inorganic filler material used> The inorganic filler materials used in the embodiments and comparative examples will be described below.

[0171] -Inorganic filler material 1- 100 parts by weight of spherical silica ("SO-C2" manufactured by ADMATECHS, with an average particle size of 0.5 μm) were added to a Henschel-type mixer. While spraying 0.6 parts by weight of a silane coupling agent containing alkoxy groups ("KBM573" manufactured by Shin-Etsu Chemical Industry Co., Ltd., N-phenyl-3-aminopropyltrimethoxysilane), the silica was stirred for 10 minutes, and then stirred at 75°C for 1 hour. Subsequently, volatile components were removed by distillation to prepare inorganic filler 1 (carbon content per unit surface area of ​​0.24 mg / m²). 2 ).

[0172] -Inorganic filler material 2- 100 parts by weight of spherical silica ("SO-C2" manufactured by ADMATECHS, with an average particle size of 0.5 μm) were added to a Henschel-type powder mixer. Simultaneously, the mixture was sprayed with an oligomer obtained by partially hydrolyzing and condensing the alkoxy groups of an oligomer containing an alkoxy-containing silane coupling agent ("KBM573" (N-phenyl-3-aminopropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Industry Co., Ltd.), followed by dehydration condensation. The resulting oligomer had a viscosity of 1045 mm. 2 0.6 parts by weight of spherical silica were stirred for 10 minutes, and then stirred at 75°C for 1 hour. Afterwards, volatile components were removed by distillation to prepare inorganic filler 2 (carbon content of 0.20 mg / m² per unit surface area). 2 ).

[0173] -Inorganic filler material 3- 100 parts by weight of spherical silica ("SO-C2" manufactured by ADMATECHS, with an average particle size of 0.5 μm) were added to a Henschel-type mixer. While spraying 0.6 parts by weight of a silane coupling agent containing alkoxy groups ("KBM403" manufactured by Shin-Etsu Chemical Industry Co., Ltd., 3-epoxypropoxypropyltrimethoxysilane), the silica was stirred for 10 minutes, and then stirred at 75°C for 1 hour. Subsequently, volatile components were removed by distillation to prepare inorganic filler 3 (carbon content per unit surface area of ​​0.22 mg / m²). 2 ).

[0174] -Inorganic filler materials 4- 100 parts by weight of spherical silica ("SO-C2" manufactured by ADMATECHS, with an average particle size of 0.5 μm) were added to a Henschel-type powder mixer while spraying an oligomeric alkoxy-containing silane coupling agent ("X-41-1056" manufactured by Shin-Etsu Chemical Industry Co., Ltd.) and a methoxysilyl resin containing epoxypropoxypropyl with a viscosity of 40 mm. 2 0.6 parts by weight of spherical silica were stirred for 10 minutes, and then stirred at 75°C for 1 hour. Afterwards, volatile components were removed by distillation to prepare inorganic filler 4 (carbon content of 0.30 mg / m² per unit surface area). 2 ).

[0175] <Determination / Calculation of Carbon Content per Unit Surface Area of ​​Inorganic Filler Materials> The carbon content per unit surface area of ​​the prepared inorganic filler material is determined / calculated according to the following steps.

[0176] Specifically, 3g of the prepared inorganic filler material was used as a sample. The sample and 30g of MEK (methyl ethyl ketone) were added to a centrifuge tube, stirred to suspend the solid components, and irradiated with 500W ultrasound for 5 minutes. Subsequently, solid-liquid separation was performed by centrifugation, and the supernatant was removed. Then, 30g of MEK was added, stirred to suspend the solid components, and irradiated with 500W ultrasound for 5 minutes. Subsequently, solid-liquid separation was performed by centrifugation, and the supernatant was removed. The solid components were dried at 150°C for 30 minutes. 0.3g of the dried sample was accurately weighed into a testing crucible, and then a combustion accelerant (3.0g of tungsten and 0.3g of tin) was added to the testing crucible. The testing crucible was placed in a carbon analyzer (Horiba Manufacturing Co., Ltd.'s "EMIA-320V") to determine the carbon content. The carbon content per unit surface area was calculated by dividing the measured carbon content by the specific surface area of ​​the inorganic filler used.

[0177] <Preparation Example 1> (Preparation of Resin Composition 1) Eight parts of naphthalene-type epoxy resin (epoxy equivalent 144, DIC's "EXA4032SS"), eleven parts of xylenol-type epoxy resin (epoxy equivalent 190, Mitsubishi Chemical's "YX4000HK"), and nine parts of naphthalene-type epoxy resin (epoxy equivalent approximately 330, Nippon Steel Chemical & Materials Co., Ltd.'s "ESN475V") were dissolved in 32 parts of solvent naphtha while stirring and heating, and then cooled to room temperature. A mixture containing 1.5 parts of rubber particles (AICA Kogyo's "Staphyloid AC3816N") swelled at 20°C in 6 parts of solvent naphtha for 12 hours, and 100.6 parts of inorganic filler 1 were mixed and kneaded using a three-roll mill to achieve uniform dispersion. A mixture of 45 parts of an active ester curing agent (“HPC-8000-65T” manufactured by DIC Corporation, and a toluene solution with 65% by mass of non-volatile components and an active group equivalent of approximately 223), 5 parts of a phenoxy resin (“YX7553” manufactured by Mitsubishi Chemical Corporation, with a weight average molecular weight of 35,000, and a 1:1 solution of MEK and cyclohexanone with 30% by mass of non-volatile components), 3 parts of a curing accelerator (1-benzyl-2-phenylimidazolium, 10% by mass of MEK solution), and 7 parts of methyl ethyl ketone (MEK) was uniformly dispersed using a rotary stirrer to prepare resin composition 1.

[0178] <Preparation Example 2> (Preparation of Resin Composition 2) Inorganic filler material 2 is used instead of inorganic filler material 1, and the resin composition 2 is prepared in the same manner as in Preparation Example 1.

[0179] <Preparation Example 3> (Preparation of Resin Composition 3) Inorganic filler 3 was used instead of inorganic filler 1, and the resin composition 3 was prepared in the same manner as in Preparation Example 1.

[0180] <Preparation Example 4> (Preparation of Resin Composition 4) Inorganic filler 4 was used instead of inorganic filler 1, and the resin composition 4 was prepared in the same manner as in Preparation Example 1.

[0181] [Example 1] (1) Preparation of resin sheets As a support, a PET film (38 μm thick, "release PET") that has been released using an alkyd resin-based release agent is prepared. Then, resin composition 1 is uniformly coated onto the release layer of the support using a die coater, with the dried resin composition layer having a thickness of 40 μm, and dried at 80–110°C (average 95°C) for 5 minutes (residual solvent content in the resin composition layer: approximately 2% by mass). Next, a polypropylene film (15 μm thick) is laminated as a protective film on the surface of the resin composition layer that is not bonded to the support. Thus, a resin sheet consisting of a release PET (support), a resin composition layer, and a protective film is obtained.

[0182] (2) Evaluation of the manufacturing of the circuit board (2-1) Lamination and thermosetting of resin composition layers on substrate The protective film is peeled off from the resin sheet to expose the resin composition layer. A silicon wafer (8 inches in size) is prepared as the substrate. The resin sheet is then laminated onto a portion of the silicon wafer using an intermittent vacuum pressure laminator ("MVLP-500" manufactured by Meiki Seisakusho), with the resin composition layer in contact with the silicon wafer. The lamination is performed by reducing the pressure to below 13 hPa for 30 seconds, followed by pressing at 100°C and 0.74 MPa for 30 seconds. Next, the resin composition layer is cured using the curing conditions (temperature, time) shown in Table 1 to form an insulating layer. After heat curing, the PET is peeled off to expose the insulating layer. This substrate is designated as substrate A.

[0183] (2-2) Chemical mechanical polishing of the insulating layer As the abrasive for chemical mechanical polishing, a substance was prepared by dispersing 200g of alumina powder (0.05μm AP-D powder manufactured by Struers) in 1L of water. The surface of the insulating layer of substrate A was then polished for 5 minutes at 100rpm using a chemical mechanical polishing apparatus (LaboForce-100 polishing apparatus manufactured by Struers). This substrate was used as substrate B.

[0184] (2-3) Formation of the coating seed layer based on sputtering method A plating seed layer is formed on the surface of the insulating layer of substrate B by sputtering. Specifically, a 30 nm thick diffusion barrier layer (Ti layer) is formed on the surface of the insulating layer of substrate B using a sputtering apparatus (CANON ANELVA E-400S), followed by the formation of a 200 nm thick conductive seed layer (Cu layer), thereby forming a 230 nm thick plating seed layer.

[0185] (2-4) Formation of conductor circuits The conductor circuit is formed using a semi-additive method. Specifically, a photoresist is applied to a substrate on which a seed layer has been formed, followed by exposure and development to expose a metal layer corresponding to a comb pattern with an L / S ratio of 2 / 2 μm (linewidth of 1 mm). Next, copper sulfate electrolytic plating is performed to form a conductor layer (conductor circuit) with a thickness of 3 μm on the exposed metal layer, after which the photoresist is removed. Then, etching (seed etching) is performed on the metal layer of the unformed portion of the first conductor circuit.

[0186] [Example 2] The resin sheet was manufactured in the same manner as in Example 1. Furthermore, the curing conditions were changed to those described in Table 1. Otherwise, the evaluation circuit board was manufactured in the same manner as in Example 1.

[0187] [Example 3] Resin composition 2 was used instead of resin composition 1, and the same procedure as in Example 1 was followed to prepare a resin sheet. Using the resulting resin sheet, an evaluation circuit board was manufactured in the same manner as in Example 1.

[0188] [Example 4] Resin composition 3 was used instead of resin composition 1, and the same procedure as in Example 1 was followed to prepare a resin sheet. Using the resulting resin sheet, an evaluation circuit board was manufactured in the same manner as in Example 1.

[0189] [Example 5] Resin composition 4 was used instead of resin composition 1, and the same procedure as in Example 1 was followed to prepare a resin sheet. Using the resulting resin sheet, an evaluation circuit board was manufactured in the same manner as in Example 1.

[0190] [Compare Examples 1 and 2] The resin sheet was manufactured in the same manner as in Example 1. Furthermore, the curing conditions were changed to those described in Table 1. Otherwise, the evaluation circuit board was manufactured in the same manner as in Example 1.

[0191] Explanation of various measurement / evaluation methods.

[0192] <Grinding amount and grinding speed in chemical mechanical polishing> The abrasion amount (thickness; μm) and abrasion speed (μm / min) of chemical mechanical polishing were measured / calculated as follows. First, for substrate A, the height difference H1 (μm) between the silicon wafer surface and the insulating layer surface was measured using a laser microscope (KEYENCE VK-X3000). Next, for the polished substrate B, the height difference H2 (μm) between the silicon wafer surface and the insulating layer surface was measured using the same laser microscope. The abrasion amount (μm) was calculated as the difference between H1 and H2, i.e., H1-H2. Furthermore, the abrasion speed (μm / min) was calculated using the formula: (H1-H2) / 5.

[0193] Surface roughness of the insulating layer after chemical mechanical polishing Using the polished surface of the insulating layer of substrate B as the measurement object, a non-contact surface roughness meter (WYKO NT3300 manufactured by Veeco Instruments) was used in VSI mode with a 50x lens and the measurement range was set to 121μm×92μm to measure the arithmetic mean roughness Ra (nm).

[0194] Determination of the glass transition temperature of resin compositions (1) Determination of glass transition temperature Tg1 Each resin composition was cured under the curing conditions shown in Table 1 to obtain cured samples. Specifically, the insulating layer of substrate A was used as the cured sample. For the cured samples, a dynamic mechanical analysis apparatus (DMA; Seiko Instruments "DMS-6100") was used to perform measurements in "tensile mode". Measurements were performed at a heating rate of 2°C / min within the range of 25°C to 240°C. The glass transition temperature Tg1 (°C) was set as the temperature at which the loss tangent (tanδ), calculated based on the ratio of the storage modulus (E') to the loss modulus (E'), reached its maximum value, rounded to the first decimal place.

[0195] (2) Determination of glass transition temperature Tg2 The protective film was peeled off from the prepared resin sheet, and after curing at 200°C for 120 minutes, the demolded PET was peeled off to obtain the cured sample. The cured sample was subjected to dynamic mechanical analysis in the same manner as in (1) above, and the glass transition temperature Tg2 (°C) was determined.

[0196] <Surface observation of the insulating layer after chemical mechanical polishing> For the surface of the insulating layer of substrate B, a scanning electron microscope (SEM) was used to observe within a field of view × 10k (N number = 10), and the number of pits caused by the shedding of inorganic filler material was counted. If the average number of pits in each field of view is less than 10, it is recorded as "0"; if the average number is more than 10, it is recorded as "×".

[0197] In Examples 1 to 5, where process (X) was performed in such a manner that 0.5 ≤ Tg1 / Tg2 ≤ 0.9 was satisfied, it was confirmed that when the insulating layer was chemically mechanically polished, a polishing speed of 1 μm / min or higher was achieved, and an insulating layer with low surface roughness was obtained. On the other hand, in Comparative Examples 1 and 2, where process (X) was performed under the condition that Tg1 / Tg2 did not satisfy the scope of the present invention, it was confirmed that when the insulating layer was chemically mechanically polished, the polishing speed was poor or the result was an insulating layer with high surface roughness.

[0198] The above embodiments show the results of research on resin compositions containing epoxy resin as a thermosetting resin. However, it has been confirmed that when using resin compositions containing other thermosetting resins, primarily polyarylether resins, or free radical polymerizable resins, by performing step (X) in a manner that satisfies 0.5≤Tg1 / Tg2≤0.9, the problem of the present invention can be solved, namely, in the manufacture of circuit boards in which the insulating layer is chemically and mechanically polished, a high polishing speed and an insulating layer with low surface roughness can be achieved.

Claims

1. A method for manufacturing a circuit board, comprising the following steps (X), (Y) and (Z): (X) A process of forming a resin composition layer by embedding the conductor post on a substrate on which an interlayer connection conductor post is provided on the surface, and curing the resin composition layer to form an insulating layer. (Y) The process of exposing the conductor pillars by grinding the insulating layer through chemical mechanical polishing (CMP); and (Z) The process of forming a seed layer on the surface of the insulating layer. When the glass transition temperature (°C) of the cured product obtained by curing the resin composition R using the curing conditions in step (X) is set as Tg1, and the glass transition temperature (°C) of the cured product obtained by curing the resin composition R at 200°C for 120 minutes is set as Tg2, step (X) is performed in such a way that 0.5≤Tg1 / Tg2≤0.9 is satisfied.

2. The method according to claim 1, wherein, In process (Z), a seed layer for plating is formed by sputtering.

3. The method according to claim 1, wherein, Process (X) includes: laminating a resin sheet containing a support and a resin composition layer disposed on the support onto a substrate in such a way that the resin composition layer is bonded to a conductor post.

4. The method according to claim 1, wherein, The grinding amount (thickness) of the insulating layer in process (Y) is more than 1μm.

5. The method according to claim 1, wherein, The grinding speed of the insulating layer in process (Y) is above 1 μm / min.

6. The method according to claim 1, wherein, The arithmetic mean roughness Ra of the polished surface of the insulating layer obtained in process (Y) is below 70 nm.

7. The method according to claim 1, wherein, The thickness of the seed layer formed in process (Z) is less than 500 nm.

8. The method according to claim 1, comprising: The process of forming a conductor layer on a seed layer by electrolytic plating.

9. The method according to claim 1, wherein, The resin composition R comprises a thermosetting resin.

10. The method according to claim 1, wherein, When the non-volatile component in resin composition R is set to 100% by mass, the content of inorganic filler material in resin composition R is 40% by mass or more.

11. The method according to claim 1, wherein, The resin composition R comprises an inorganic filler material treated with an alkoxy-containing surface treatment agent.

12. The method according to claim 11, wherein, The surface treatment agent containing alkoxy groups is selected from one or more silane coupling agents and their oligomers containing alkoxy groups.

13. The method according to claim 11, wherein, The carbon content per unit surface area of ​​the inorganic filler material is 0.05 mg / m². 2 above.

14. The method according to claim 1, wherein, Tg2 is above 150℃.

15. The method according to any one of claims 1 to 14, wherein, Circuit boards are used for semiconductor packaging.

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