JP2023130968A - Method for manufacturing circuit board - Google Patents

Abstract

To provide a method for manufacturing a circuit board with increased adhesion and less warpage.SOLUTION: The method for manufacturing a circuit board sequentially includes the steps of: (A) preparing an insulation resin film including a supporting body and a resin composition layer on the supporting body, made of a resin composition; (B) laminating the insulation resin film on an inner layer substrate so that the resin composition layer is joined to the inner layer substrate; (C) thermally hardening the resin composition layer and forming an insulation layer; (E) forming a via in the insulation layer and forming a conductor layer on the insulation layer; (F) heating the insulation layer at temperatures of 175°C and 205°C, both inclusive; and (G) heating the insulation layer at temperatures of at least 110°C and less than 175°C. The resin composition includes an epoxy resin, a hardening agent, and an inorganic filler. The inorganic filler is contained in the concentration of 40-80 mass% of the nonvolatile component defined as 100 mass% of the resin composition. When the heating temperature in Step (F) is T3(°C) and the heating temperature in Step (G) is T4(°C), the relation of 20°C≤T3-T4≤70°C is satisfied.SELECTED DRAWING: None

Description

The present invention relates to a method for manufacturing a circuit board.

As a manufacturing technique for multilayer printed wiring boards, a manufacturing method using a build-up method in which insulating layers and conductive layers are alternately stacked on an inner layer substrate is known. The insulating layer is generally formed by curing a resin composition.

For example, Patent Document 1 discloses forming an insulating layer in a printed wiring board using a resin composition containing a cyanate ester resin, a specific epoxy resin, and an active ester curing agent. It is described that it is possible to achieve both low roughness and high peel strength of a conductor layer formed by plating, and further to lower the coefficient of thermal expansion (CTE).

Japanese Patent Application Publication No. 2011-144361

In recent years, due to the need for miniaturization of electronic devices and electronic components, miniaturization and higher density of wiring are required in circuit boards. As wiring becomes finer and more dense, it becomes more important to reduce warpage of the inner layer substrate, and in order to reduce warpage, an inner layer substrate with a low coefficient of thermal expansion is required.

In order to achieve a low coefficient of thermal expansion, it is possible to incorporate a high content of inorganic fillers such as silica into the insulating layer, but since the amount of resin components contained in the resin composition is reduced, There is a problem that the adhesion between the conductive layer and the insulating layer in the substrate is reduced, and delamination is likely to occur.

On the other hand, if the degree of hardening of the insulating layer is further increased by heating the insulating layer after forming the conductive layer on the insulating layer, it is possible to improve the adhesion between the conductive layer and the insulating layer, but the heat curing causes warping. The problem was that it was more likely to occur.

The present invention was devised in view of the above-mentioned problems, and it is an object of the present invention to provide a method for manufacturing a circuit board that suppresses the occurrence of warpage and improves adhesion.

In order to achieve the objects of the present invention, the inventors of the present invention have made extensive studies and found that after forming a conductor layer on an insulating layer, the heating temperature during heat treatment and the heating time during annealing treatment satisfy a predetermined relationship. The inventors have discovered that it is possible to suppress the occurrence of warpage and improve adhesion by performing heat treatment and annealing treatment, and have completed the present invention.

That is, the present invention includes the following contents.
[1] (A) A step of preparing an insulating resin film including a support and a resin composition layer formed of a resin composition provided on the support;
(B) a step of laminating an insulating resin film on the inner layer substrate so that the resin composition layer is bonded to the inner layer substrate;
(C) a step of thermosetting the resin composition layer to form an insulating layer;
(E) forming a via in the insulating layer and further forming a conductor layer on the insulating layer;
(F) a step of heating the insulating layer at a temperature of 175° C. or more and 205° C. or less, and (G) a step of heating the insulating layer at a temperature of 110° C. or more and less than 175° C., in this order,
The resin composition includes an epoxy resin, a curing agent, and an inorganic filler,
The content of the inorganic filler is 40% by mass or more and 80% by mass or less, when the nonvolatile components of the resin composition are 100% by mass,
A method for manufacturing a circuit board that satisfies 20°C≦T3−T4≦70°C, where the heating temperature in step (F) is T3 (°C) and the heating temperature in step (G) is T4 (°C).
[2] After step (C) and before step (E),
(D) The method for manufacturing a circuit board according to [1], including the step of heating the insulating layer.
[3] The method for manufacturing a circuit board according to [2], wherein the heating temperature T2 in step (D) is 100°C or more and 150°C or less.
[4] After step (F) and before step (G),
(F-1) The method for manufacturing a circuit board according to any one of [1] to [3], further comprising the step of cooling the insulating layer.
[5] The method for manufacturing a circuit board according to any one of [1] to [4], wherein the heating time in step (F) is 10 minutes or more.
[6] The method for manufacturing a circuit board according to any one of [1] to [5], wherein the heating time in step (G) is 10 minutes or more.
[7] The method for manufacturing a circuit board according to any one of [1] to [6], wherein the heating temperature T1 in step (C) is 100° C. or more and 190° C. or less.

According to the present invention, it is possible to provide a method for manufacturing a circuit board that suppresses the occurrence of warpage and improves adhesion.

Hereinafter, the present invention will be explained in detail based on its preferred embodiments. However, the present invention is not limited to the following embodiments and examples, and may be implemented with arbitrary changes within the scope of the claims of the present invention and equivalents thereof.

Before explaining in detail the method of manufacturing a circuit board of the present invention, the insulating resin film used in the manufacturing method of the present invention will be explained.

[Insulating resin film]
The insulating resin film used in the method for manufacturing a circuit board of the present invention includes a support and a resin composition layer formed of a resin composition provided on the support. Each layer constituting the insulating resin film will be described in detail below.

<Support>
The insulating resin film includes a support. Examples of the support include a film made of a plastic material, a metal foil, and a release paper, and a film made of a plastic material and a metal foil are preferred.

When using a film made of a plastic material as a support, examples of the plastic material include polyethylene terephthalate (hereinafter sometimes abbreviated as "PET") and polyethylene naphthalate (hereinafter sometimes abbreviated as "PEN"). ), polyesters such as polycarbonate (hereinafter sometimes abbreviated as "PC"), acrylics such as polymethyl methacrylate (PMMA), cyclic polyolefins, triacetyl cellulose (TAC), polyether sulfide (PES), polyether Examples include ketones and polyimides. Among these, polyethylene terephthalate and polyethylene naphthalate are preferred, and inexpensive polyethylene terephthalate is particularly preferred.

When using metal foil as the support, examples of the metal foil include copper foil, aluminum foil, etc., with copper foil being preferred. As the copper foil, a foil made of a single metal such as copper may be used, or a foil made of an alloy of copper and other metals (for example, tin, chromium, silver, magnesium, nickel, zirconium, silicon, titanium, etc.) may be used. May be used.

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

Further, as the support, a support with a release layer may be used, which has a release layer on the surface of the side bonded to the resin composition layer. Examples of the release agent used in the release layer of the support with a release layer include one or more release agents selected from the group consisting of alkyd resins, polyolefin resins, urethane resins, and silicone resins. Among these, it is preferable to include one or more mold release agents selected from the group consisting of alkyd resins, polyolefin resins, and urethane resins. As the support with a release layer, commercially available products may be used, such as "SK-1", "AL-5", "AL-7" manufactured by Lintec, "Lumirror T60" manufactured by Toray Industries, Inc., and "Lumirror T60" manufactured by Teijin Corporation. Examples include PET films with a release layer containing an alkyd resin mold release agent as a main component, such as "Purex" manufactured by Co., Ltd. and "Unipeel" manufactured by Unitika; "U2-NR1" manufactured by DuPont Films; It will be done.

The thickness of the support is not particularly limited, but is preferably in the range of 5 μm to 75 μm, more preferably in the range of 10 μm to 60 μm. In addition, when using the support body with a mold release layer, it is preferable that the thickness of the whole support body with a mold release layer is in the said range.

<Resin composition layer>
The insulating resin film includes a resin composition layer made of a resin composition. The resin composition layer is bonded to the support to form an insulating resin film, and when manufacturing a circuit board, the resin composition layer is laminated on the inner layer substrate, and the insulating layer is formed by thermosetting. The resin composition forming the resin composition layer contains an epoxy resin, a curing agent, and an inorganic filler, and the content of the inorganic filler is 40% by mass when the nonvolatile components of the resin composition are 100% by mass. Examples include compositions in which the content is 80% by mass or less. The resin composition may further contain a thermoplastic resin, a curing accelerator, and other additives, if necessary.

-Epoxy resin-
The resin composition contains an epoxy resin. Examples of the epoxy resin include bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, bisphenol AF epoxy resin, dicyclopentadiene epoxy resin, trisphenol epoxy resin, naphthol novolak epoxy resin, Phenol novolac type epoxy resin, tert-butyl-catechol type epoxy resin, naphthalene type epoxy resin, naphthol type epoxy resin, anthracene type epoxy resin, glycidylamine type epoxy resin, glycidyl ester type epoxy resin, cresol novolac type epoxy resin, biphenyl type Epoxy resin, linear aliphatic epoxy resin, epoxy resin with butadiene structure, alicyclic epoxy resin, heterocyclic epoxy resin, spiro ring-containing epoxy resin, cyclohexanedimethanol type epoxy resin, naphthylene ether type epoxy resin, Examples include methylol type epoxy resin. Epoxy resins may be used alone or in combination of two or more.

The epoxy resin preferably contains an epoxy resin having two or more epoxy groups in one molecule. From the viewpoint of significantly obtaining the desired effects of the present invention, the proportion of the epoxy resin having two or more epoxy groups in one molecule is preferably 50% by mass or more, based on 100% by mass of the nonvolatile components of the epoxy resin. It is more preferably 60% by mass or more, particularly preferably 70% by mass or more.

Epoxy resins are classified into epoxy resins that are liquid at a temperature of 20°C (hereinafter referred to as "liquid epoxy resins") and epoxy resins that are solid at a temperature of 20°C (hereinafter referred to as "solid epoxy resins"). The resin composition may contain only liquid epoxy resin or only solid epoxy resin as the epoxy resin, but from the viewpoint of significantly obtaining the effects of the present invention, liquid epoxy resin and solid epoxy resin may be used. It is preferable to include it in combination with an epoxy resin.

As the liquid epoxy resin, a liquid epoxy resin having two or more epoxy groups in one molecule is preferable.

Liquid epoxy resins include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AF type epoxy resin, naphthalene type epoxy resin, glycidyl ester type epoxy resin, glycidylamine type epoxy resin, phenol novolak type epoxy resin, and ester skeleton. Alicyclic epoxy resins, cyclohexane-type epoxy resins, cyclohexanedimethanol-type epoxy resins, glycidylamine-type epoxy resins, and epoxy resins having a butadiene structure are preferred, and bisphenol A-type epoxy resins and bisphenol F-type epoxy resins are more preferred.

Specific examples of liquid epoxy resins include "HP4032", "HP4032D", "HP4032SS" (naphthalene type epoxy resin) manufactured by DIC; "828US", "jER828EL", "825", and "Epicoat" manufactured by Mitsubishi Chemical Corporation. 828EL" (bisphenol A type epoxy resin); "jER807", "1750" (bisphenol F type epoxy resin) manufactured by Mitsubishi Chemical; "jER152" (phenol novolac type epoxy resin) manufactured by Mitsubishi Chemical; manufactured by Mitsubishi Chemical “630” and “630LSD” (glycidylamine type epoxy resin); “ZX1059” manufactured by Nippon Steel Chemical & Materials (mixture of bisphenol A type epoxy resin and bisphenol F type epoxy resin); manufactured by Nagase ChemteX Co., Ltd. "EX-721" (glycidyl ester type epoxy resin); Daicel's "Celoxide 2021P" (alicyclic epoxy resin with ester skeleton); Daicel's "PB-3600" (epoxy resin with butadiene structure) Examples include "ZX1658" and "ZX1658GS" (liquid 1,4-glycidylcyclohexane type epoxy resin) manufactured by Nippon Steel Chemical & Materials. These may be used alone or in combination of two or more.

As the solid epoxy resin, a solid epoxy resin having three or more epoxy groups in one molecule is preferable, and an aromatic solid epoxy resin having three or more epoxy groups in one molecule is more preferable.

Solid epoxy resins include bixylenol type epoxy resin, naphthalene type epoxy resin, naphthalene type tetrafunctional epoxy resin, cresol novolak type epoxy resin, dicyclopentadiene type epoxy resin, trisphenol type epoxy resin, naphthol type epoxy resin, and biphenyl. Type epoxy resins, naphthylene ether type epoxy resins, anthracene type epoxy resins, bisphenol A type epoxy resins, bisphenol AF type epoxy resins, and tetraphenylethane type epoxy resins are preferred, and bixylenol type epoxy resins, naphthalene type epoxy resins, and naphthylene type epoxy resins are preferred. Ether type epoxy resins and bisphenol AF type epoxy resins are more preferred.

Specific examples of solid epoxy resins include "HP4032H" (naphthalene type epoxy resin), "HP-4700", "HP-4710" (naphthalene type tetrafunctional epoxy resin), and "N-690" (manufactured by DIC). Cresol novolac type epoxy resin), "N-695" (Cresol novolac type epoxy resin), "HP-7200", "HP-7200HH", "HP-7200H" (dicyclopentadiene type epoxy resin), "EXA-7311" ”, “EXA-7311-G3”, “EXA-7311-G4”, “EXA-7311-G4S”, “HP6000”, “HP6000L” (naphthylene ether type epoxy resin); “EPPN” manufactured by Nippon Kayaku Co., Ltd. -502H” (trisphenol type epoxy resin), “NC7000L” (naphthol novolak type epoxy resin), “NC3000H”, “NC3000”, “NC3000L”, “NC3100” (biphenyl type epoxy resin); Nippon Steel Chemical & Materials Co., Ltd. "ESN475V" (naphthalene type epoxy resin), "ESN485" (naphthol novolac type epoxy resin) manufactured by Mitsubishi Chemical; "YX4000H", "YL6121" (biphenyl type epoxy resin), "YX4000HK" (bixylenol type epoxy resin) manufactured by Mitsubishi Chemical Corporation. Resin), "YX8800" (anthracene type epoxy resin); "PG-100", "CG-500" manufactured by Osaka Gas Chemical Company, "YX7760" (bisphenol AF type epoxy resin) manufactured by Mitsubishi Chemical Company, "YL7800" (fluorene type epoxy resin), "jER1010" (solid bisphenol A type epoxy resin), "jER1031S" (tetraphenylethane type epoxy resin), and the like. These may be used alone or in combination of two or more.

When a solid epoxy resin and a liquid epoxy resin are used in combination as the epoxy resin, their mass ratio (solid epoxy resin: liquid epoxy resin) is preferably 1:0.01 to 1:50, more preferably The ratio is 1:0.05 to 1:20, particularly preferably 1:0.1 to 1:10. By setting the ratio of the liquid epoxy resin to the solid epoxy resin within such a range, 1) appropriate tackiness is provided when used in the form of an insulating resin film, and 2) appropriate tackiness is provided when used in the form of an insulating resin film. In this case, the following effects can be obtained: sufficient flexibility is obtained, handling properties are improved, and 3) a cured product having sufficient breaking strength can be obtained.

The epoxy equivalent of the epoxy resin is preferably 50 g/eq. ～5000g/eq. , more preferably 50g/eq. ～3000g/eq. , more preferably 80g/eq. ～2000g/eq. , even more preferably 110 g/eq. ～1000g/eq. It is. Within this range, a cured product of the resin composition with sufficient crosslinking density can be obtained. Epoxy equivalent is the mass of epoxy resin containing one equivalent of epoxy groups. This epoxy equivalent can be measured according to JIS K7236.

The weight average molecular weight (Mw) of the epoxy resin is preferably from 100 to 5,000, more preferably from 250 to 3,000, even more preferably from 400 to 1,500, from the viewpoint of significantly obtaining the desired effects of the present invention. The weight average molecular weight of the epoxy resin is the weight average molecular weight in terms of polystyrene measured by gel permeation chromatography (GPC).

From the viewpoint of obtaining a cured product exhibiting good mechanical strength and insulation reliability, the content of the epoxy resin is preferably 1% by mass or more, more preferably 5% by mass when the nonvolatile component in the resin composition is 100% by mass. It is at least 10% by mass, more preferably at least 10% by mass. The upper limit of the content of the epoxy resin is preferably 50% by mass or less, more preferably 45% by mass or less, still more preferably 40% by mass or less, or 30% by mass or less, from the viewpoint of significantly obtaining the desired effects of the present invention. be.

-Hardening agent-
The resin composition contains a curing agent. The curing agent is not particularly limited as long as it has the function of curing the epoxy resin, and examples thereof include phenol curing agents, naphthol curing agents, active ester curing agents, benzoxazine curing agents, and cyanate ester curing agents. Can be mentioned. Among these, the curing agent preferably contains one or more selected from phenolic curing agents and active ester curing agents, and preferably contains phenolic curing agents, from the viewpoint of significantly obtaining the effects of the present invention. More preferred. One type of curing agent may be used alone, or two or more types may be used in combination.

As the phenol curing agent and the naphthol curing agent, from the viewpoint of heat resistance and water resistance, a phenol curing agent having a novolak structure or a naphthol curing agent having a novolak structure is preferable. Further, from the viewpoint of adhesion strength with the conductor layer, a nitrogen-containing phenol curing agent or a nitrogen-containing naphthol curing agent is preferable, and a triazine skeleton-containing phenol curing agent or a triazine skeleton-containing naphthol curing agent is more preferable. Among these, triazine skeleton-containing phenol novolac resins are preferred from the viewpoint of highly satisfying heat resistance, water resistance, and adhesion strength with the conductor layer. These may be used alone or in combination of two or more.

Specific examples of phenolic curing agents and naphthol curing agents include "MEH-7700", "MEH-7810", and "MEH-7851" manufactured by Meiwa Kasei Co., Ltd., "NHN" manufactured by Nippon Kayaku Co., Ltd. "CBN", "GPH", Nippon Steel Chemical & Materials' "SN170", "SN180", "SN190", "SN475", "SN485", "SN495", "SN-495V", "SN375", " Examples include "SN395", "TD-2090", "LA-7052", "LA-7054", "LA-1356", "LA-3018-50P", and "EXB-9500" manufactured by DIC Corporation.

The active ester curing agent is not particularly limited, but generally one molecule of an ester group with high reaction activity, such as phenol esters, thiophenol esters, N-hydroxyamine esters, and esters of heterocyclic hydroxy compounds, is used. Compounds having two or more in them are preferably used. The active ester compound is preferably one obtained by a condensation reaction between a carboxylic acid compound and/or a thiocarboxylic acid compound and a hydroxy compound and/or a thiol compound. Particularly from the viewpoint of improving heat resistance, active ester compounds obtained from a carboxylic acid compound and a hydroxy compound are preferred, and active ester compounds obtained from a carboxylic acid compound and a phenol compound and/or a naphthol compound are more preferred. Examples of the carboxylic acid compound include benzoic acid, acetic acid, succinic acid, maleic acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, and pyromellitic acid. Examples of phenolic compounds or naphthol compounds include hydroquinone, resorcinol, bisphenol A, bisphenol F, bisphenol S, phenolphthalin, methylated bisphenol A, methylated bisphenol F, methylated bisphenol S, phenol, o-cresol, m- Cresol, p-cresol, catechol, α-naphthol, β-naphthol, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, phloroglucin, Examples include benzenetriol, dicyclopentadiene type diphenol compounds, and phenol novolacs. Here, the term "dicyclopentadiene type diphenol compound" refers to a diphenol compound obtained by condensing two molecules of phenol with one molecule of dicyclopentadiene.

Examples of active ester curing agents include dicyclopentadiene-type active ester compounds, naphthalene-type active ester compounds containing a naphthalene structure, active ester compounds containing acetylated products of phenol novolak, and active ester compounds containing benzoylated products of phenol novolak. Ester compounds are preferred, and at least one selected from dicyclopentadiene-type active ester compounds and naphthalene-type active ester compounds is more preferred. As the dicyclopentadiene type active ester compound, an active ester compound containing a dicyclopentadiene type diphenol structure is preferable.

Commercially available active ester curing agents include "EXB9451," "EXB9460," "EXB9460S," "HPC-8000L-65TM," and "HPC-8000-65T," which are active ester compounds containing a dicyclopentadiene-type diphenol structure. ", "HPC-8000H", "HPC-8000H-65TM" (manufactured by DIC); "HP-B-8151-62T", "EXB-8100L-65T", "EXB- 9416-70BK", "HPC-8150-62T", "EXB-8" (manufactured by DIC); as a phosphorus-containing active ester compound, "EXB9401" (manufactured by DIC), an active ester compound that is an acetylated product of phenol novolak "DC808" (manufactured by Mitsubishi Chemical Corporation), "YLH1026", "YLH1030", "YLH1048" (manufactured by Mitsubishi Chemical Corporation) as active ester compounds that are benzoylated products of phenol novolak, active ester compounds containing a styryl group and a naphthalene structure. Examples include "PC1300-02-65MA" (manufactured by Air Water).

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

Examples of cyanate ester curing agents include bisphenol A dicyanate, polyphenol cyanate, oligo(3-methylene-1,5-phenylene cyanate), 4,4'-methylenebis(2,6-dimethylphenyl cyanate), 4,4 '-Ethylidene diphenyl dicyanate, hexafluorobisphenol A dicyanate, 2,2-bis(4-cyanate) phenylpropane, 1,1-bis(4-cyanate phenylmethane), bis(4-cyanate-3,5-dimethyl Bifunctional cyanate resins such as phenyl)methane, 1,3-bis(4-cyanatophenyl-1-(methylethylidene))benzene, bis(4-cyanatophenyl)thioether, and bis(4-cyanatophenyl)ether, phenol Examples include polyfunctional cyanate resins derived from novolacs and cresol novolaks, and prepolymers in which these cyanate resins are partially triazinized. Specific examples of cyanate ester curing agents include "PT30" and "PT60" (phenol novolak type polyfunctional cyanate ester resin), "ULL-950S" (polyfunctional cyanate ester resin), and "BA230" manufactured by Lonza Japan. , "BA230S75" (a prepolymer in which part or all of bisphenol A dicyanate is triazinized to form a trimer), and the like.

The carbodiimide curing agent is a compound having one or more carbodiimide groups (-N=C=N-) in one molecule, and the carbodiimide curing agent is preferably a compound having two or more carbodiimide groups in one molecule. .

As specific examples of carbodiimide curing agents, commercially available carbodiimide curing agents include Carbodilite V-03 (carbodiimide group equivalent: 216), V-05 (carbodiimide group equivalent: 262), V-05 (carbodiimide group equivalent: 262), manufactured by Nisshinbo Chemical Co., Ltd. -07 (carbodiimide group equivalent: 200); V-09 (carbodiimide group equivalent: 200); and Stabaxol P (carbodiimide group equivalent: 302) manufactured by Rhein Chemie.

The quantitative ratio of the epoxy resin to the curing agent is the ratio of [total number of epoxy groups in the epoxy resin]:[total number of active groups in the curing agent], and is preferably in the range of 1:0.01 to 1:5. The ratio is more preferably 1:0.1 to 1:3, and even more preferably 1:0.3 to 1:2. Here, "the number of epoxy groups in the epoxy resin" is the sum of all the values obtained by dividing the mass of nonvolatile components of the epoxy resin present in the resin composition by the epoxy equivalent. Moreover, "the number of active groups of a curing agent" is the total value of all the values obtained by dividing the mass of nonvolatile components of the curing agent present in the resin composition by the active group equivalent. By setting the amount ratio of the curing agent to the epoxy resin within this range, the effects of the present invention can be significantly obtained.

From the viewpoint of significantly obtaining the desired effects of the present invention, the content of the curing agent is preferably 1% by mass or more, more preferably 5% by mass or more, when the nonvolatile component in the resin composition is 100% by mass. More preferably, it is 10% by mass or more. The upper limit is preferably 25% by mass or less, more preferably 20% by mass or less, still more preferably 15% by mass or less.

-Inorganic filler-
The resin composition contains an inorganic filler. By including the inorganic filler in the resin composition, it becomes possible to suppress the occurrence of warping of the cured product of the resin composition.

From the viewpoint of reducing the CTE of the cured product of the resin composition, the content of the inorganic filler is 40% by mass or more, preferably 50% by mass or more when the nonvolatile components in the resin composition are 100% by mass. , more preferably 55% by mass or more, still more preferably 60% by mass or more. The upper limit is 80% by mass or less, preferably 75% by mass or less, more preferably 70% by mass or less, even more preferably 65% by mass or less.

An inorganic compound is used as the material for the inorganic filler. 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 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, calcium carbonate and silica are preferred, and silica is particularly preferred. Examples of silica include amorphous silica, fused silica, crystalline silica, synthetic silica, and hollow silica. Further, as the silica, spherical silica is preferable. One type of inorganic filler may be used alone, or two or more types may be used in combination.

Commercially available inorganic fillers include, for example, "ST7030-20" manufactured by Nippon Steel Chemical &Materials; "MSS-6" and "AC-5V" manufactured by Ryumori; and "SP60-05" manufactured by Nippon Steel & Sumikin Materials. ", "SP507-05"; Admatex "YC100C", "YA050C", "YA050C-MJE", "YA010C"; Denka "UFP-30", "SFP-130MC", "FB-7SDC" , "FB-5SDC", "FB-3SDC"; Tokuyama "Silfill NSS-3N", "Silfill NSS-4N", "Silfill NSS-5N"; Admatex "SC2500SQ", "SO-C4" , "SO-C2", "SO-C1", "FE9", etc.

The specific surface area of the inorganic filler is preferably 1 m ² /g or more, more preferably 2 m ² /g or more, particularly preferably 3 m ² /g or more. Although there is no particular limit to the upper limit, it is preferably 60 m ² /g or less, 50 m ² /g or less, or 40 m ² /g or less. The specific surface area can be obtained by adsorbing nitrogen gas on the sample surface using a specific surface area measuring device (Macsorb HM-1210 manufactured by Mountec) according to the BET method, and calculating the specific surface area using the BET multi-point method. .

The average particle size of the inorganic filler is preferably 0.01 μm or more, more preferably 0.05 μm or more, even more preferably 0.1 μm or more, and preferably 20 μm, from the viewpoint of significantly obtaining the desired effects of the present invention. The thickness is more preferably 15 μm or less, and even more preferably 10 μm or less.

The average particle size of the inorganic filler can be measured by a laser diffraction/scattering method based on Mie scattering theory. Specifically, it can be measured by creating the particle size distribution of the inorganic filler on a volume basis using a laser diffraction scattering type particle size distribution measuring device, and using the median diameter as the average particle size. The measurement sample can be obtained by weighing 100 mg of the inorganic filler and 10 g of methyl ethyl ketone into a vial and dispersing them using ultrasonic waves for 10 minutes. The measurement sample was measured using a laser diffraction particle size distribution measuring device using a light source wavelength of blue and red, and the volume-based particle size distribution of the inorganic filler was measured using a flow cell method. The average particle size can be calculated as the median diameter. Examples of the laser diffraction particle size distribution measuring device include "LA-960" manufactured by Horiba, Ltd.

The inorganic filler is preferably treated with a surface treatment agent from the viewpoint of improving moisture resistance and dispersibility. Examples of the surface treatment agent include vinyl silane coupling agents, (meth)acrylic coupling agents, fluorine-containing silane coupling agents, aminosilane coupling agents, epoxysilane coupling agents, mercaptosilane coupling agents, Examples include silane coupling agents, alkoxysilanes, organosilazane compounds, titanate coupling agents, and the like. Among them, from the viewpoint of significantly obtaining the effects of the present invention, vinylsilane coupling agents, (meth)acrylic coupling agents, aminosilane coupling agents, epoxysilane coupling agents, and silane coupling agents are preferred, and aminosilane More preferred are a type coupling agent, an epoxysilane type coupling agent, and a silane type coupling agent. Moreover, one type of surface treatment agent may be used alone, or two or more types may be used in any combination.

Commercially available surface treatment agents include, for example, "KBM1003" (vinyltriethoxysilane) manufactured by Shin-Etsu Chemical, "KBM503" (3-methacryloxypropyltriethoxysilane) manufactured by Shin-Etsu Chemical, and "KBM503" (3-methacryloxypropyltriethoxysilane) manufactured by Shin-Etsu Chemical. "KBM403" (3-glycidoxypropyltrimethoxysilane), "KBM803" (3-mercaptopropyltrimethoxysilane) manufactured by Shin-Etsu Chemical, "KBE903" (3-aminopropyltriethoxysilane) manufactured by Shin-Etsu Chemical , "KBM573" (N-phenyl-3-aminopropyltrimethoxysilane) manufactured by Shin-Etsu Chemical, "SZ-31" (hexamethyldisilazane) manufactured by Shin-Etsu Chemical, "KBM103" (phenyl trimethoxysilane), "KBM-4803" (long chain epoxy type silane coupling agent) manufactured by Shin-Etsu Chemical, "KBM-7103" (3,3,3-trifluoropropyltrimethoxysilane) manufactured by Shin-Etsu Chemical etc.

The degree of surface treatment with the surface treatment agent is preferably within a predetermined range from the viewpoint of improving the dispersibility of the inorganic filler. Specifically, 100 parts by mass of the inorganic filler is preferably surface-treated with 0.2 parts by mass to 5 parts by mass of a surface treatment agent, and preferably 0.2 parts by mass to 3 parts by mass. Preferably, the surface treatment is carried out in an amount of 0.3 parts by mass to 2 parts by mass.

The degree of surface treatment by the surface treatment agent can be evaluated by the amount of carbon per unit surface area of the inorganic filler. The amount of carbon per unit surface area of the inorganic filler is preferably 0.02 mg/m ² or more, more preferably 0.1 mg/m ² or more, and 0.2 mg/m ² from the viewpoint of improving the dispersibility of the inorganic filler. The above is more preferable. On the other hand, from the viewpoint of suppressing an increase in the melt viscosity of the resin varnish and the melt viscosity in the form of a film, it is preferably 1 mg/m ² or less, more preferably 0.8 mg/m ² or less, and even more preferably 0.5 mg/m ² or less. preferable.

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

-Thermoplastic resin-
The resin composition may further contain a thermoplastic resin as an optional component in combination with the above-mentioned epoxy resin, curing agent, and inorganic filler. This thermoplastic resin does not include any of the components listed above.

Examples of thermoplastic resins include phenoxy resin, polyimide resin, polyvinyl acetal resin, polyolefin resin, polybutadiene resin, polyamideimide resin, polyetherimide resin, polysulfone resin, polyether sulfone resin, polyphenylene ether resin, polycarbonate resin, and polyether. Examples include ether ketone resin and polyester resin. One type of thermoplastic resin may be used alone, or two or more types may be used in combination.

Examples of phenoxy resins include bisphenol A skeleton, bisphenol F skeleton, bisphenol S skeleton, bisphenolacetophenone skeleton, novolac skeleton, biphenyl skeleton, fluorene skeleton, dicyclopentadiene skeleton, norbornene skeleton, naphthalene skeleton, anthracene skeleton, adamantane skeleton, and terpene. Examples include phenoxy resins having one or more types of skeletons selected from the group consisting of a skeleton and a trimethylcyclohexane skeleton. The terminal of the phenoxy resin may be any functional group such as a phenolic hydroxyl group or an epoxy group. Specific examples of phenoxy resins include "1256" and "4250" manufactured by Mitsubishi Chemical Corporation (both phenoxy resins containing bisphenol A skeleton); "YX8100" manufactured by Mitsubishi Chemical Corporation (phenoxy resin containing bisphenol S skeleton); "YX6954" (phenoxy resin containing bisphenolacetophenone skeleton) manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.; "FX280" and "FX293" manufactured by Nippon Steel & Sumikin Chemical; "YL7500BH30", "YX6954BH30", "YX7553", "YX7553BH30" manufactured by Mitsubishi Chemical Corporation, Examples include "YX6954," "YL7769BH30," "YL6794," "YL7213," "YL7290," "YL7482," and "YL7891BH30."

Specific examples of polyimide resins include "SLK-6100" manufactured by Shin-Etsu Chemical Co., Ltd., "Ricacoat SN20" and "Ricacoat PN20" manufactured by Shinnihon Rika Co., Ltd., and the like.

Examples of the polyvinyl acetal resin include polyvinyl formal resin and polyvinyl butyral resin, with polyvinyl butyral resin being preferred. Specific examples of polyvinyl acetal resin include Denka Butyral 4000-2, Denka Butyral 5000-A, Denka Butyral 6000-C, and Denka Butyral 6000-EP manufactured by Denki Kagaku Kogyo; Sekisui Chemical Co., Ltd. Examples include the S-LEC BH series, BX series (for example, BX-5Z), KS series (for example, KS-1), BL series, and BM series manufactured by the company.

Examples of polyolefin resins include ethylene copolymers such as low density polyethylene, ultra-low density polyethylene, high density polyethylene, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, and ethylene-methyl acrylate copolymer. Resin; Examples include polyolefin polymers such as polypropylene and ethylene-propylene block copolymers.

Examples of polybutadiene resins include hydrogenated polybutadiene skeleton-containing resins, hydroxy group-containing polybutadiene resins, phenolic hydroxyl group-containing polybutadiene resins, carboxy group-containing polybutadiene resins, acid anhydride group-containing polybutadiene resins, epoxy group-containing polybutadiene resins, and isocyanate group-containing polybutadiene resins. Examples include polybutadiene resin, urethane group-containing polybutadiene resin, polyphenylene ether-polybutadiene resin, and the like.

Specific examples of the polyamide-imide resin include "Viromax HR11NN" and "Viromax HR16NN" manufactured by Toyobo. Specific examples of polyamide-imide resins include modified polyamide-imides such as "KS9100" and "KS9300" (polysiloxane skeleton-containing polyamide-imide) manufactured by Hitachi Chemical.

A specific example of the polyether sulfone resin includes "PES5003P" manufactured by Sumitomo Chemical Co., Ltd.

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

A specific example of the polyphenylene ether resin includes "NORYL SA90" manufactured by SABIC. A specific example of the polyetherimide resin includes "Ultem" manufactured by GE.

Examples of the polycarbonate resin include hydroxy group-containing carbonate resins, phenolic hydroxyl group-containing carbonate resins, carboxy group-containing carbonate resins, acid anhydride group-containing carbonate resins, isocyanate group-containing carbonate resins, urethane group-containing carbonate resins, and the like. Specific examples of polycarbonate resins include "FPC0220" manufactured by Mitsubishi Gas Chemical Co., Ltd., "T6002" and "T6001" (polycarbonate diol) manufactured by Asahi Kasei Chemicals, and "C-1090" and "C-2090" manufactured by Kuraray Corporation. , "C-3090" (polycarbonate diol), and the like. Specific examples of polyetheretherketone resins include "Sumiploy K" manufactured by Sumitomo Chemical Co., Ltd., and the like.

Examples of the polyester resin include polyethylene terephthalate resin, polyethylene naphthalate resin, polybutylene terephthalate resin, polybutylene naphthalate resin, polytrimethylene terephthalate resin, polytrimethylene naphthalate resin, polycyclohexane dimethyl terephthalate resin, and the like.

The weight average molecular weight (Mw) of the thermoplastic resin is preferably larger than 5,000, more preferably 8,000 or more, even more preferably 10,000 or more, particularly preferably 20,000 or more, preferably 100, 000 or less, more preferably 70,000 or less, still more preferably 60,000 or less, particularly preferably 50,000 or less.

The amount of thermoplastic resin is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, even more preferably 0.5% by mass or more, when the nonvolatile components in the resin composition are 100% by mass. The content is preferably 15% by mass or less, more preferably 10% by mass or less, even more preferably 8% by mass or less.

-Curing accelerator-
The resin composition may further contain a curing accelerator as an optional component in combination with the above-mentioned epoxy resin, curing agent, and inorganic filler. This curing accelerator does not include any of the components listed above. The curing accelerator has a function as a curing catalyst that promotes curing of the epoxy resin.

Examples of the curing accelerator include phosphorus-based curing accelerators, urea-based curing accelerators, guanidine-based curing accelerators, imidazole-based curing accelerators, metal-based curing accelerators, and amine-based curing accelerators. One type of curing accelerator may be used alone, or two or more types may be used in combination.

Examples of the phosphorus curing accelerator include tetrabutylphosphonium decane salt, tetrabutylphosphonium bromide, tetrabutylphosphonium chloride, tetrabutylphosphonium acetate, tetrabutylphosphonium decanoate, tetrabutylphosphonium laurate, bis(tetrabutyl phosphonium) pyromellitate, tetrabutylphosphonium hydrogen hexahydrophthalate, tetrabutylphosphonium 2,6-bis[(2-hydroxy-5-methylphenyl)methyl]-4-methylphenolate, di-tert-butyldimethylphosphonium tetraphenyl Aliphatic phosphonium salts such as borates; methyltriphenylphosphonium bromide, ethyltriphenylphosphonium bromide, propyltriphenylphosphonium bromide, butyltriphenylphosphonium bromide, benzyltriphenylphosphonium chloride, tetraphenylphosphonium bromide, p-tolyltriphenylphosphonium tetra -p-tolylborate, tetraphenylphosphonium tetraphenylborate, tetraphenylphosphonium tetrap-tolylborate, triphenylethylphosphonium tetraphenylborate, tris(3-methylphenyl)ethylphosphonium tetraphenylborate, tris(2-methoxyphenyl) Aromatic phosphonium salts such as ethylphosphonium tetraphenylborate, (4-methylphenyl)triphenylphosphonium thiocyanate, tetraphenylphosphonium thiocyanate, butyltriphenylphosphonium thiocyanate; aromatic phosphine-borane complexes such as triphenylphosphine-triphenylborane ; Aromatic phosphine/quinone addition reaction products such as triphenylphosphine/p-benzoquinone addition reaction products; Tributylphosphine, tri-tert-butylphosphine, trioctylphosphine, di-tert-butyl (2-butenyl) phosphine, di- Aliphatic phosphine such as tert-butyl(3-methyl-2-butenyl)phosphine, tricyclohexylphosphine; dibutylphenylphosphine, di-tert-butylphenylphosphine, methyldiphenylphosphine, ethyldiphenylphosphine, butyldiphenylphosphine, diphenylcyclohexylphosphine , triphenylphosphine, tri-o-tolylphosphine, tri-m-tolylphosphine, tri-p-tolylphosphine, tris(4-ethylphenyl)phosphine, tris(4-propylphenyl)phosphine, tris(4-isopropylphenyl) ) phosphine, tris(4-butylphenyl)phosphine, tris(4-tert-butylphenyl)phosphine, tris(2,4-dimethylphenyl)phosphine, tris(2,5-dimethylphenyl)phosphine, tris(2,6 -dimethylphenyl)phosphine, tris(3,5-dimethylphenyl)phosphine, tris(2,4,6-trimethylphenyl)phosphine, tris(2,6-dimethyl-4-ethoxyphenyl)phosphine, tris(2-methoxy phenyl)phosphine, tris(4-methoxyphenyl)phosphine, tris(4-ethoxyphenyl)phosphine, tris(4-tert-butoxyphenyl)phosphine, diphenyl-2-pyridylphosphine, 1,2-bis(diphenylphosphino) Ethane, 1,3-bis(diphenylphosphino)propane, 1,4-bis(diphenylphosphino)butane, 1,2-bis(diphenylphosphino)acetylene, 2,2'-bis(diphenylphosphino)diphenyl ether Examples include aromatic phosphines such as.

Examples of the urea-based curing accelerator include 1,1-dimethylurea; 1,1,3-trimethylurea, 3-ethyl-1,1-dimethylurea, 3-cyclohexyl-1,1-dimethylurea, 3- Aliphatic dimethylurea such as cyclooctyl-1,1-dimethylurea; 3-phenyl-1,1-dimethylurea, 3-(4-chlorophenyl)-1,1-dimethylurea, 3-(3,4-dichlorophenyl) )-1,1-dimethylurea, 3-(3-chloro-4-methylphenyl)-1,1-dimethylurea, 3-(2-methylphenyl)-1,1-dimethylurea, 3-(4- methylphenyl)-1,1-dimethylurea, 3-(3,4-dimethylphenyl)-1,1-dimethylurea, 3-(4-isopropylphenyl)-1,1-dimethylurea, 3-(4- methoxyphenyl)-1,1-dimethylurea, 3-(4-nitrophenyl)-1,1-dimethylurea, 3-[4-(4-methoxyphenoxy)phenyl]-1,1-dimethylurea, 3- [4-(4-chlorophenoxy)phenyl]-1,1-dimethylurea, 3-[3-(trifluoromethyl)phenyl]-1,1-dimethylurea, N,N-(1,4-phenylene) Aromatic dimethylurea such as bis(N',N'-dimethylurea), N,N-(4-methyl-1,3-phenylene)bis(N',N'-dimethylurea) [toluene bisdimethylurea] etc.

Examples of the guanidine-based curing accelerator include dicyandiamide, 1-methylguanidine, 1-ethylguanidine, 1-cyclohexylguanidine, 1-phenylguanidine, 1-(o-tolyl)guanidine, dimethylguanidine, diphenylguanidine, trimethylguanidine, Tetramethylguanidine, pentamethylguanidine, 1,5,7-triazabicyclo[4.4.0]dec-5-ene, 7-methyl-1,5,7-triazabicyclo[4.4.0] Dec-5-ene, 1-methylbiguanide, 1-ethylbiguanide, 1-n-butylbiguanide, 1-n-octadecylbiguanide, 1,1-dimethylbiguanide, 1,1-diethylbiguanide, 1-cyclohexylbiguanide, 1 -allyl biguanide, 1-phenyl biguanide, 1-(o-tolyl) biguanide and the like.

Examples of imidazole-based curing accelerators include 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazolium trimellitate, 1-cyanoethyl- 2-Phenylimidazolium trimellitate, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-undecyl imidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4- Diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole, 2- Phenyl-4-methyl-5-hydroxymethylimidazole, 2,3-dihydro-1H-pyrrolo[1,2-a]benzimidazole, 1-dodecyl-2-methyl-3-benzylimidazolium chloride, 2-methylimidazoline , imidazole compounds such as 2-phenylimidazoline, and adducts of imidazole compounds and epoxy resins. Commercially available imidazole curing accelerators include, for example, "1B2PZ", "2E4MZ", "2MZA-PW", "2MZ-OK", "2MA-OK", and "2MA-OK-" manufactured by Shikoku Kasei Kogyo Co., Ltd. PW", "2PHZ", "2PHZ-PW", "Cl1Z", "Cl1Z-CN", "Cl1Z-CNS", "C11Z-A"; "P200-H50" manufactured by Mitsubishi Chemical Corporation, and the like.

Examples of the metal hardening accelerator include organometallic complexes or organometallic salts of metals such as cobalt, copper, zinc, iron, nickel, manganese, and tin. Specific examples of organometallic complexes include organic cobalt complexes such as cobalt (II) acetylacetonate and cobalt (III) acetylacetonate, organic copper complexes such as copper (II) acetylacetonate, and zinc (II) acetylacetonate. Examples include organic zinc complexes such as , organic iron complexes such as iron (III) acetylacetonate, organic nickel complexes such as nickel (II) acetylacetonate, and organic manganese complexes such as manganese (II) acetylacetonate. Examples of the organic metal salt include zinc octylate, tin octylate, zinc naphthenate, cobalt naphthenate, tin stearate, and zinc stearate.

Examples of the amine curing accelerator include trialkylamines such as triethylamine and tributylamine, 4-dimethylaminopyridine, benzyldimethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, and 1,8-diazabicyclo. Examples include (5,4,0)-undecene and the like. As the amine curing accelerator, commercially available products may be used, such as "MY-25" manufactured by Ajinomoto Fine Techno.

The amount of the curing accelerator is preferably 0.01% by mass or more, more preferably 0.02% by mass or more, even more preferably 0.05% by mass or more, when the nonvolatile components in the resin composition are 100% by mass. The content is preferably 5% by mass or less, more preferably 4% by mass or less, even more preferably 0.2% by mass or less.

-Optional additives-
The resin composition may further contain arbitrary additives as arbitrary non-volatile components in combination with the above-mentioned components. Examples of optional additives include flame retardants; polymerization initiators; organometallic compounds such as organocopper compounds, organozinc compounds, and organocobalt compounds; phthalocyanine blue, phthalocyanine green, iodine green, diazo yellow, crystal violet, oxidation Coloring agents such as titanium and carbon black; Polymerization inhibitors such as hydroquinone, catechol, pyrogallol, and phenothiazine; Leveling agents such as silicone leveling agents and acrylic polymer leveling agents; Thickeners such as bentone and montmorillonite; Silicone antifoaming agents Antifoaming agents such as acrylic antifoaming agents, fluorine antifoaming agents, and vinyl resin antifoaming agents; Ultraviolet absorbers such as benzotriazole ultraviolet absorbers; Adhesion improvers such as urea silane; Triazole adhesion Adhesion-imparting agents such as adhesion-imparting agents, tetrazole-based adhesion-imparting agents, and triazine-based adhesion-imparting agents; Antioxidants such as hindered phenol-based antioxidants; Fluorescent brighteners such as stilbene derivatives; Fluorine-based surfactants Surfactants such as silicone surfactants; phosphorus flame retardants (e.g. phosphoric acid ester compounds, phosphazene compounds, phosphinic acid compounds, red phosphorus), nitrogen flame retardants (e.g. melamine sulfate), halogen flame retardants, Flame retardants such as inorganic flame retardants (e.g. antimony trioxide); phosphate ester dispersants, polyoxyalkylene dispersants, acetylene dispersants, silicone dispersants, anionic dispersants, cationic dispersants, etc. Dispersants; Stabilizers such as borate stabilizers, titanate stabilizers, aluminate stabilizers, zirconate stabilizers, isocyanate stabilizers, carboxylic acid stabilizers, carboxylic acid anhydride stabilizers; tertiary Examples include photopolymerization initiation aids such as amines; photosensitizers such as pyrarizones, anthracenes, coumarins, xanthones, and thioxanthones. One type of arbitrary additive may be used alone, or two or more types may be used in combination.

The thickness of the resin composition layer is preferably 200 μm or less, more preferably 100 μm or less, still more preferably 80 μm or less, even more preferably 60 μm or less, or 50 μm or less, from the viewpoint of making the circuit board thinner. In particular, the thickness is preferably 30 μm or less, more preferably 20 μm or less, and even more preferably 15 μm or less, since it facilitates the formation of small diameter vias. The lower limit of the thickness of the resin composition layer is not particularly limited, but is usually 3 μm or more.

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

The insulating resin film can be made, for example, by using a liquid (varnish-like) resin composition as it is, or by dissolving the resin composition in a solvent to prepare a liquid (varnish-like) resin composition, and then coating it with a die coater or the like. It can be manufactured by applying the resin composition onto a support using a device and further drying to form a resin composition layer.

Examples of solvents used in the preparation of the resin varnish include ketone solvents such as acetone, methyl ethyl ketone (MEK) and cyclohexanone, and acetate ester solvents such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate and carbitol acetate. , carbitol solvents such as cellosolve and butyl carbitol, aromatic hydrocarbon solvents such as toluene and xylene, and amide solvents such as dimethylformamide, dimethylacetamide and N-methylpyrrolidone. One type of solvent may be used alone, or two or more types may be used in combination.

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

In the insulating resin film, a protective film similar to the support can be further laminated on the surface of the resin composition layer that is not bonded to the support (ie, the surface opposite to the support). The thickness of the protective film is not particularly limited, and may be, for example, 1 μm to 40 μm. By laminating the protective film, it is possible to prevent dust and the like from adhering to the surface of the resin composition layer and from scratching it. The insulating resin film can be wound up into a roll and stored, and can be used when manufacturing a circuit board by peeling off the protective film.

[Circuit board manufacturing method]
The method for manufacturing a circuit board of the present invention includes:
(A) preparing an insulating resin film including a support and a resin composition layer formed of a resin composition provided on the support;
(B) a step of laminating an insulating resin film on the inner layer substrate so that the resin composition layer is bonded to the inner layer substrate;
(C) a step of thermosetting the resin composition layer to form an insulating layer;
(E) forming a via in the insulating layer and further forming a conductor layer on the insulating layer;
(F) a step of heating the insulating layer at a temperature of 175° C. or more and 205° C. or less, and (G) a step of heating the insulating layer at a temperature of 110° C. or more and less than 175° C., in this order,
When the heating temperature in step (F) is T3 (°C) and the heating temperature in step (G) is T4 (°C), 20°C≦T3−T4≦70°C is satisfied.

The method for manufacturing a circuit board of the present invention may include the following step (D) as necessary.
(D) heating the insulating layer;
It is preferable that step (D) is performed after step (C) and before step (E). Therefore, the method for manufacturing a circuit board of the present invention is preferably carried out in the order of step (A) to step (G).

According to such a manufacturing method, it is possible to suppress the occurrence of warpage and provide a circuit board with improved adhesion. By performing step (F), the insulating layer can be sufficiently cured and the adhesion between the conductor layer and the insulating layer can be improved. However, as a result of intensive research by the present inventors, step (F) After step (G) is performed, specifically, the heating temperature in step (G) is adjusted so that the heating temperature in step (F) and the heating temperature in step (G) satisfy a predetermined relationship. By further performing annealing treatment after step (F), the residual stress accumulated in the insulating layer is relaxed, and as a result, it is possible to achieve both adhesion between the conductor layer and the insulating layer and suppression of warping. .

Each step in the method for manufacturing a circuit board of the present invention will be described below.

<Process (A)>
In step (A), an insulating resin film is prepared. The insulating resin film is as described above.

<Process (B)>
In step (B), an insulating resin film is laminated on the inner layer substrate so that the resin composition layer is bonded to the inner layer substrate to obtain a laminate.

The inner layer substrate is a member that serves as a substrate for a circuit board and a printed wiring board, and includes, for example, a glass epoxy substrate, a metal substrate, a polyester substrate, a polyimide substrate, a BT resin substrate, a thermosetting polyphenylene ether substrate, and the like. Further, the substrate may have a conductor layer on one or both sides, and this conductor layer may be patterned. Further, when manufacturing a printed wiring board, an intermediate product on which an insulating layer and/or a conductive layer is to be further formed is also included in the inner layer substrate. If the circuit board is a circuit board with built-in components, an inner layer board with built-in components can be used.

An insulating resin film is laminated on the inner layer substrate so that the resin composition layer is bonded to the inner layer substrate to obtain a laminate. In one embodiment, the inner layer substrate and the insulating resin film can be laminated by, for example, heat-pressing the insulating resin film onto the inner layer substrate from the support side. Examples of the member for heat-pressing the insulating resin film to the inner layer substrate (hereinafter also referred to as "heat-pressing member") include a heated metal plate (SUS mirror plate, etc.) or a metal roll (SUS roll). Note that, instead of pressing the thermocompression bonding member directly onto the insulating resin film, it is preferable to press it through an elastic material such as heat-resistant rubber so that the insulating resin film sufficiently follows the surface irregularities of the inner layer substrate.

The inner layer substrate and the insulating resin film may be laminated by a vacuum lamination method. In the vacuum lamination method, the heat-pressing temperature is preferably in the range of 60°C to 160°C, more preferably 80°C to 140°C, and the heat-pressing pressure is preferably in the range of 0.098 MPa to 1.77 MPa, more preferably 0. The pressure is in the range of .29 MPa to 1.47 MPa, and the heat-pressing time is preferably in the range of 10 seconds to 400 seconds, more preferably 20 seconds to 300 seconds. Further, the lamination is preferably carried out under reduced pressure conditions of 26.7 hPa or less.

Lamination can be performed using a commercially available vacuum laminator. Examples of commercially available vacuum laminators include a vacuum pressure laminator manufactured by Meiki Seisakusho, a vacuum applicator manufactured by Nikko Materials, and a batch vacuum pressure laminator.

After lamination, the laminated insulating resin films may be smoothed under normal pressure (atmospheric pressure), for example, by pressing a thermocompression bonding member from the support side. The pressing conditions for the smoothing treatment can be the same as the conditions for the heat-pressing of the lamination described above. The smoothing process can be performed using a commercially available laminator. Note that the lamination and smoothing treatment may be performed continuously using the above-mentioned commercially available vacuum laminator.

<Step (C)>
In step (C), the resin composition layer is thermally cured to form an insulating layer. Usually, the curing reaction of the resin composition does not proceed completely due to the thermal curing in step (C). Therefore, the heat curing in step (C) is sometimes called "half cure."

The heat curing temperature T1 (°C) of the resin composition layer in step (C) is preferably 100°C or higher, more preferably 150°C or higher, and even more preferably 160°C or higher. The upper limit is preferably 190°C or lower, more preferably 188°C or lower, even more preferably 185°C or lower.

The heat curing time of the resin composition layer in step (C) varies depending on the type of resin composition, etc., but is preferably 5 minutes or more, more preferably 10 minutes or more, and even more preferably 20 minutes or more, with an upper limit of is not particularly limited, but is preferably 120 minutes or less, more preferably 100 minutes or less, and still more preferably 90 minutes or less. The heating time of the resin composition layer means the time to maintain the curing heating temperature of the resin composition layer. Thermal curing is usually carried out under a gas atmosphere (for example air, argon gas, nitrogen gas or a mixture thereof), for example under a pressure of 0.05 MPa to 0.15 MPa, preferably 0.08 to 0.12 MPa. It will be done.

In the method for manufacturing a circuit board, the resin composition layer may be preheated at a temperature lower than the heat curing temperature T1 before step (C).

The preheating temperature of the resin composition layer is preferably 50°C or higher, more preferably 100°C or higher, even more preferably 120°C or higher, preferably 160°C or lower, more preferably 150°C or lower, and still more preferably 140°C or higher. below ℃. The preheating time of the resin composition layer is preferably 5 minutes or more, more preferably 10 minutes or more, even more preferably 15 minutes or more, and preferably 150 minutes or less, more preferably 130 minutes or less, and still more preferably 120 minutes or more. minutes or less. Preheating is usually performed under a gas atmosphere (for example, air, argon gas, nitrogen gas, or a mixture thereof), for example, under a pressure of 0.05 MPa to 0.15 MPa, preferably 0.08 to 0.12 MPa. It will be done.

After step (C) and before step (D) and step (E), it is preferable to include a step (C-1) of cooling the insulating layer. The cooling temperature is about room temperature (20°C to 25°C), preferably 35°C or lower, more preferably 30°C or lower, and even more preferably 25°C or lower. The lower limit is preferably 0°C or higher, more preferably 5°C or higher, even more preferably 10°C or higher. The cooling method is not particularly limited, and the insulating layer may be left to cool, or may be cooled by blowing cold air onto the insulating layer, pressing the insulating layer against a cooled roll, or the like. Cooling in this step is usually performed under a gas atmosphere (for example, air, argon gas, nitrogen gas, or a mixture thereof), for example, at a pressure of 0.05 MPa to 0.15 MPa, preferably 0.08 to 0.12 MPa. It takes place below.

The thickness of the insulating layer formed by thermosetting in step (C) depends on the thickness of the resin composition layer of the prepared insulating resin film, but is, for example, 200 μm or less, preferably 100 μm or less, more preferably 80 μm or less, and Preferably it is 60 μm or less, particularly preferably 50 μm or less, and the lower limit is not particularly limited, but can usually be 1 μm or more, 5 μm or more, 10 μm or more, etc.

The degree of hardening of the insulating layer after step (C) is preferably 50% or more, more preferably 60% or more, and even more preferably 70% or more, from the viewpoint of improving the adhesion between the conductor layer and the insulating layer. . The lower limit of the degree of curing is preferably 95% or less, more preferably 90% or less. The degree of curing can be measured using, for example, a differential scanning calorimeter or a Fourier transform infrared spectrometer.

<Step (D)>
In step (D), the insulating layer is heated to relieve stress caused by curing of the resin composition layer.

The heating temperature T2 (° C.) of the insulating layer is preferably lower than the curing heating temperature T1. Specifically, the temperature is preferably 100°C or higher, more preferably 110°C or higher, and still more preferably 120°C or higher. The upper limit is preferably 150°C or lower, more preferably 145°C or lower, even more preferably 140°C or lower.

The heating time of the insulating layer varies depending on the type of resin composition, etc., but is preferably 5 minutes or more, more preferably 10 minutes or more, and even more preferably 15 minutes or more, and the upper limit is not particularly limited. However, it is preferably 120 minutes or less, more preferably 100 minutes or less, and even more preferably 90 minutes or less. The heating time of the insulating layer means the time to maintain the heating temperature of the insulating layer. Heating is usually performed under a gas atmosphere (for example, air, argon gas, nitrogen gas, or a mixture thereof), for example, under a pressure of 0.05 MPa to 0.15 MPa, preferably 0.08 to 0.12 MPa. be exposed.

Step (D) may be performed only once, or may be performed multiple times. When performing the heating multiple times, the heating temperature and heating time may be the same as or different from the first heating temperature and heating time.

After step (D) and before step (E), it is preferable to include a step (D-1) of cooling the insulating layer. The cooling temperature etc. are the same as in step (C-1).

The difference (T1-T2) between the heating temperature T1 in step (C) and the heating temperature T2 in step (D) is preferably 30° C. or higher, more preferably 40° C. or higher, from the viewpoint of significantly obtaining the effects of the present invention. ℃ or higher, more preferably 45℃ or higher. The upper limit is preferably 70°C or lower, more preferably 60°C or lower, even more preferably 50°C or lower.

<Step (E)>
In step (E), vias are formed in the insulating layer, and a conductor layer is further formed on the insulating layer. Step (E) preferably includes the following steps (E-1), (E-2), and (E-3) in this order.
(E-1) Step of forming vias in the insulating layer,
(E-2) A step of roughening the insulating layer, and (E-3) A step of forming a conductor layer on the insulating layer.

In step (E-1), a via hole is formed by drilling on the surface of the insulating layer. As a result, a via hole is usually formed in the insulating layer, and the conductor layer of the inner substrate is exposed at the bottom of the via hole.

Via holes are usually provided for electrical connection between layers, and can be formed by a known method using a drill, laser, plasma, etc., taking into consideration the characteristics of the insulating layer, and it is preferable to use a laser. .

Examples of laser light sources that can be used to form via holes include CO ₂ laser (carbon dioxide laser), UV-YAG laser, UV laser, YAG laser, excimer laser, and the like. Among these, CO ₂ laser or UV-YAG laser is preferred from the viewpoint of processing speed and cost.

In irradiating the laser, the number of shots is preferably 5 or less, more preferably 3 or less, from the viewpoint of improving the workability of the via hole. In order to keep the number of shots within the above range, it is preferable to set the laser energy and pulse width to a certain value or more. The output of the laser is preferably 0.1 W or more, more preferably 0.3 W or more, even more preferably 0.5 W or more, and preferably 30 W or less, more preferably 10 W or less, and still more preferably 5 W or less. Further, the pulse width of the laser is preferably 0.5 μsec or more, more preferably 1 μsec or more, even more preferably 3 μsec or more, and preferably 35 μsec or less, more preferably 30 μsec or less, and still more preferably 25 μsec or less.

Via holes can be formed using a commercially available laser device. Commercially available carbon dioxide laser devices include, for example, "LC-2E21B/1C" manufactured by Hitachi Via Mechanics, "ML605GTWII" manufactured by Mitsubishi Electric, "605GTWIII (-P)" manufactured by Mitsubishi Electric, and Matsushita Welding Systems. An example of this is the board drilling laser processing machine manufactured by Manufacturer. Furthermore, examples of the UV-YAG laser device include "LU-2L212/M50L" manufactured by Via Mechanics.

Although the shape of the via hole is not particularly limited, it is generally circular (substantially circular). Further, the opening diameter (top diameter) of the via hole that can be formed by performing step (E-1) is preferably 5 μm or more, more preferably 10 μm or more, more preferably 20 μm or more, 30 μm or more, or 40 μm or more. , preferably 100 μm or less, more preferably 90 μm or less, still more preferably 80 μm or less, 70 μm or less, or 60 μm or less. Here, the opening diameter (top diameter) of the via hole refers to the diameter of the opening of the via hole on the surface of the insulating layer.

In step (E-2), the surface of the insulating layer is roughened (desmearing process), and while the surface of the insulating layer is being roughened, the smear in the via hole is removed. The procedure and conditions of the roughening treatment are not particularly limited as long as the surface of the insulating layer can be roughened and smears within the via holes can be removed. As the roughening treatment, for example, a swelling treatment using a swelling liquid, a roughening treatment using an oxidizing agent, and a neutralization treatment using a neutralizing liquid are performed in this order.

Examples of the swelling liquid used in the roughening treatment include alkaline solutions, surfactant solutions, etc., and preferably alkaline solutions. As the alkaline solution, sodium hydroxide solution and potassium hydroxide solution are more preferable. Examples of commercially available swelling liquids include "Swelling Dip Securigance P" and "Swelling Dip Securigance SBU" manufactured by Atotech Japan. Swelling treatment with a swelling liquid is not particularly limited, but can be carried out, for example, by immersing the object in a swelling liquid at 30° C. to 90° C. for 1 minute to 20 minutes. From the viewpoint of significantly obtaining the effects of the present invention, it is preferable to immerse the object in the swelling liquid at 40° C. to 80° C. for 5 minutes to 15 minutes.

Examples of the oxidizing agent used in the roughening treatment include an alkaline permanganate solution in which potassium permanganate or sodium permanganate is dissolved in an aqueous solution of sodium hydroxide. The roughening treatment with an oxidizing agent such as an alkaline permanganic acid solution is preferably carried out by immersing the object in an oxidizing agent solution heated to 60° C. to 100° C. for 10 minutes to 30 minutes. Further, the concentration of permanganate in the alkaline permanganic acid solution is preferably 5% by mass to 10% by mass. Examples of commercially available oxidizing agents include alkaline permanganate solutions such as "Concentrate Compact CP" and "Dosing Solution Securigance P" manufactured by Atotech Japan.

The neutralizing solution used in the roughening treatment is preferably an acidic aqueous solution, and a commercially available product includes, for example, "Reduction Solution Securigant P" manufactured by Atotech Japan. The treatment with the neutralizing liquid can be carried out by immersing the treated surface that has been desmeared with an oxidizing agent in the neutralizing liquid at 30° C. to 80° C. for 1 minute to 30 minutes. From the viewpoint of workability, etc., it is preferable to immerse the object that has been desmeared with an oxidizing agent in a neutralizing solution at 30° C. to 70° C. for 3 minutes to 20 minutes.

The arithmetic mean roughness (Ra) of the surface of the insulating layer after the roughening treatment is preferably 500 nm or less, more preferably 400 nm or less, and still more preferably 300 nm or less. The lower limit is not particularly limited, and may be, for example, 1 nm or more, 2 nm or more, etc. Further, the root mean square roughness (Rq) of the surface of the insulating layer after the desmear treatment is preferably 500 nm or less, more preferably 400 nm or less, and even more preferably 300 nm or less. The lower limit is not particularly limited, and may be, for example, 1 nm or more, 2 nm or more, etc. The arithmetic mean roughness (Ra) and root mean square roughness (Rq) of the surface of the insulating layer can be measured using a non-contact surface roughness meter.

In step (E-3), a conductor layer is formed on the insulating layer. The conductor material used for the conductor layer is not particularly limited. In a preferred embodiment, the conductor layer includes one or more selected from the group consisting of gold, platinum, palladium, silver, copper, aluminum, cobalt, chromium, zinc, nickel, titanium, tungsten, iron, tin, and indium. Contains metal. The conductor layer may be a single metal layer or an alloy layer, and the alloy layer may be, for example, an alloy of two or more metals selected from the above group (for example, a nickel-chromium alloy, a copper-chromium alloy, a copper-chromium alloy, etc.). nickel alloys and copper-titanium alloys). Among these, from the viewpoint of versatility in forming conductor layers, cost, ease of patterning, etc., monometallic layers of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver, or copper, nickel-chromium alloys, copper, etc. An alloy layer of nickel alloy or copper/titanium alloy is preferable, a single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver or copper, or an alloy layer of nickel/chromium alloy is more preferable, and a single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver or copper is more preferable. A metal layer is more preferred.

The conductor layer may have a single layer structure, or may have a multilayer structure in which two or more single metal layers or alloy layers made of different types of metals or alloys are laminated. When the conductor layer has a multilayer structure, the layer in contact with the insulating layer is preferably a single metal layer of chromium, zinc, or titanium, or an alloy layer of nickel-chromium alloy.

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

The conductor layer can be formed by any conventionally known suitable method such as plating, sputtering, vapor deposition, etc., and is preferably formed by plating. In a preferred embodiment, a conductive layer having a desired wiring pattern is formed by plating the surface of the insulating layer using a conventionally known technique such as a semi-additive method or a fully additive method. An example of forming a conductor layer by a semi-additive method will be shown below.

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

As a method for forming the plating seed layer, the plating seed layer is formed by electroless plating on the surface of the insulating layer after the heat treatment. First, alkali cleaning is performed to clean the surface of the insulating layer and adjust the charge. Next, in order to apply Pd (palladium) to the surface of the insulating layer, a pre-dip step is performed to adjust the charge on the surface of the insulating layer. Next, Pd as an activator is applied to the surface, and the Pd applied to the insulating layer is reduced. Next, copper (Cu) is deposited on the surface of the insulating layer to form a plating seed layer.

After forming the plating seed layer, a mask pattern is formed to expose a portion of the plating seed layer. The mask pattern can be formed, for example, by bonding a dry film to a plating seed layer and performing exposure, development, and cleaning under predetermined conditions.

As the dry film, a photosensitive dry film made of a photoresist composition can be used. Examples of such dry films include dry films of novolak resin, acrylic resin, and the like. As the dry film, commercially available products may be used, such as "Photoc RY-3600" manufactured by Hitachi Chemical Co., Ltd. and "ALPHO 20A263" manufactured by Nikko Materials Co., Ltd., for example.

Next, an electrolytic plating layer is formed on the exposed plating seed layer by electrolytic plating. When a via hole is provided, an electrolytic plating layer may be formed on the exposed plating seed layer by electrolytic plating, and the via hole may be filled by electrolytic plating to form a filled via.

After forming the electroplated layer, the mask pattern is removed and unnecessary plating seed layer is removed by flash etching. Flash etching is performed under any suitable conditions to form a patterned conductor layer. Further, after removing the mask pattern, annealing treatment may be performed as necessary.

The mask pattern can be removed using, for example, an alkaline removing solution such as a sodium hydroxide solution.

The annealing treatment can be performed, for example, by heating the inner layer substrate at 150 to 200° C. for 20 to 90 minutes.

Flash etching is usually performed using an etchant such as an etching solution. For example, when the material of the pattern conductor layer is copper, examples of the etching solution include an etching solution containing hydrogen peroxide as a main component (hydrogen peroxide-based etching solution), an acidic etching solution, an alkaline etching solution, and the like. Among these, a hydrogen peroxide-based etching solution is preferred from the viewpoint of significantly obtaining the effects of the present invention.

As the hydrogen peroxide-based etching solution, an etching solution containing hydrogen peroxide and an inorganic acid is preferable, and examples of the inorganic acid include sulfuric acid, nitric acid, phosphoric acid, etc., and sulfuric acid and phosphoric acid are preferable. The inorganic acids may be used alone or in combination of two or more. A commercially available hydrogen peroxide-based etching solution can be used, such as the etching solution SAC series (manufactured by Ebara Densan Co., Ltd.).

Examples of the acidic etching solution include an aqueous ferric chloride solution, an aqueous solution containing sodium peroxodisulfate and sulfuric acid, and an etching solution containing nitric acid and sulfuric acid as main components. As the acidic etching solution, commercially available products can be used, such as NH-1865 manufactured by MEC Corporation and Melstrip N-950 manufactured by Meltex Corporation.

As the alkaline etching solution, commercially available products can be used, such as CF-6000 manufactured by MEC Corporation and E-Process-WL manufactured by Meltex Corporation.

Flash etching can be performed by immersing the inner layer substrate in an etching solution or by spraying the etching solution, but immersion in an etching solution is preferable from the viewpoint of significantly obtaining the effects of the present invention.

The temperature of the etching solution is preferably 5°C or higher, more preferably 10°C or higher, even more preferably 15°C or higher, and preferably 60°C or lower, more preferably 50°C, from the viewpoint of significantly obtaining the effects of the present invention. The temperature is preferably below 40°C.

The support of the insulating resin film is removed between step (B) and step (C), between step (C) and step (D), or between step (D) and step (E). or may be carried out in step (E). When removing the support in step (E), it is preferable to remove the support before step (E-2).

Furthermore, if necessary, the steps (A) to (E) for forming the insulating layer and the conductor layer may be repeated to form a multilayer wiring board.

<Process (F)>
In step (F), the insulating layer is heated at a temperature of 175° C. or more and 205° C. or less to increase the degree of hardening of the insulating layer. Usually, the curing reaction of the resin composition sufficiently progresses by thermal curing in step (F). Therefore, the heat curing in step (F) is sometimes called "full cure." By performing step (F), it becomes possible to improve the adhesion between the insulating layer and the conductor layer.

The heating temperature T3 (°C) of the insulating layer is 175°C or higher, preferably 180°C or higher, more preferably 185°C or higher, and even more preferably 188°C or higher. The upper limit is 205°C or lower, preferably 200°C or lower, more preferably 195°C or lower, even more preferably 193°C or lower.

The heating time of the insulating layer varies depending on the type of resin composition, etc., but is preferably 10 minutes or more, more preferably 30 minutes or more, and even more preferably 50 minutes or more, and the upper limit is not particularly limited. However, it is preferably 120 minutes or less, more preferably 100 minutes or less, and even more preferably 90 minutes or less. The heating time of the insulating layer means the time to maintain the heating temperature of the insulating layer. Heating is usually performed under a gas atmosphere (for example, air, argon gas, nitrogen gas, or a mixture thereof), for example, under a pressure of 0.05 MPa to 0.15 MPa, preferably 0.08 to 0.12 MPa. be exposed.

Step (F) may be performed only once, or may be performed multiple times. When performing the heating multiple times, the heating temperature and heating time may be the same as or different from the first heating temperature and heating time. In addition, when performing step (F) multiple times, each heating temperature and each heating time are preferably within the above range, and if T3-T4 satisfies the specified range in any of the multiple steps (F), good.

After step (F) and before step (G), it is preferable to include a step (F-1) of cooling the insulating layer. The cooling temperature etc. are the same as in step (C-1).

<Process (G)>
In step (G), the insulating layer is heated at a temperature of 110° C. or more and less than 175° C. to relieve stress generated by heating the insulating layer in step (F). By performing step (G), the stress accumulated inside the insulating layer is relaxed, and it becomes possible to suppress the occurrence of warpage of the circuit board.

The heating temperature T4 (°C) of the insulating layer is 110°C or higher, preferably 113°C or higher, more preferably 115°C or higher, even more preferably 118°C or higher. The upper limit is less than 175°C, preferably 170°C or less, more preferably 165°C or less, even more preferably 160°C or less.

The difference (T3-T4) between the heating temperature T3 in step (F) and the heating temperature T4 in step (G) is 20% from the viewpoint of suppressing the occurrence of warpage and manufacturing a circuit board with improved adhesion. ℃ or higher, preferably 21℃ or higher, more preferably 22℃ or higher, still more preferably 23℃ or higher, 25℃ or higher, 30℃ or higher, or 35℃ or higher. The upper limit is 70°C or lower, preferably 65°C or lower, more preferably 60°C or lower, even more preferably 55°C or lower.

The heating time of the insulating layer varies depending on the type of resin composition, etc., but is preferably 10 minutes or more, more preferably 20 minutes or more, and even more preferably 30 minutes or more, and the upper limit is not particularly limited. However, it is preferably 60 minutes or less, more preferably 50 minutes or less, and even more preferably 45 minutes or less. The heating time of the insulating layer means the time to maintain the heating temperature of the insulating layer. Heating is usually performed under a gas atmosphere (for example, air, argon gas, nitrogen gas, or a mixture thereof), for example, under a pressure of 0.05 MPa to 0.15 MPa, preferably 0.08 to 0.12 MPa. be exposed.

Step (G) may be performed only once or multiple times. When performing the heating multiple times, the heating temperature and heating time may be the same as or different from the first heating temperature and heating time. In addition, when performing step (G) multiple times, each heating temperature and each heating time are preferably within the above range, and if T3-T4 satisfies the specified range in any of the multiple steps (G), good.

After step (G), it is preferable to include a step (G-1) of cooling the insulating layer. The cooling temperature etc. are the same as in step (C-1).

<Semiconductor device>
A semiconductor device including a circuit board can be manufactured using a circuit board obtained by the manufacturing method of the present invention.

Examples of semiconductor devices include various semiconductor devices used in electrical products (eg, computers, mobile phones, digital cameras, televisions, etc.), vehicles (eg, motorcycles, automobiles, trains, ships, aircraft, etc.), and the like.

A semiconductor device can be manufactured by mounting components (semiconductor chips) at conductive locations on a circuit board. A conductive location is a location on a circuit board that transmits an electrical signal, and the location may be a surface or a buried location. Further, the semiconductor chip is not particularly limited as long as it is an electric circuit element made of a semiconductor.

The mounting method for semiconductor chips when manufacturing semiconductor devices is not particularly limited as long as the semiconductor chip functions effectively, but specifically, wire bonding mounting method, flip chip mounting method, bumpless buildup layer, etc. Examples include a mounting method using (BBUL), a mounting method using an anisotropic conductive film (ACF), a mounting method using a non-conductive film (NCF), and the like.

Hereinafter, the present invention will be specifically explained with reference to Examples. The present invention is not limited to these examples. In addition, in the following, "parts" and "%" representing amounts mean "parts by mass" and "% by mass", respectively, unless otherwise specified. The temperature conditions in the following description are room temperature (20° C. to 25° C.) unless the temperature is specified, and the pressure conditions are normal pressure (0.1 MPa) unless the pressure is specified.

<Production Example 1: Production of resin composition 1>
15 parts of liquid bisphenol A-type epoxy resin (epoxy equivalent: 180 g/eq., "jER828EL" manufactured by Mitsubishi Chemical Corporation), 30 parts of biphenyl-type epoxy resin (epoxy equivalent: 290 g/eq., "NC3000H" manufactured by Nippon Kayaku Co., Ltd.), 5 parts of naphthalene-type tetrafunctional epoxy resin (epoxy equivalent: 162 g/eq., "HP-4700" manufactured by DIC Corporation), phenoxy resin ("YX7553" manufactured by Mitsubishi Chemical Corporation), methyl ethyl ketone (hereinafter referred to as "MEK") with a nonvolatile content of 30% by mass. ) and 2 parts of a 1:1 solution of cyclohexanone were dissolved in 8 parts of MEK and 8 parts of cyclohexanone by heating with stirring. There, 32 parts of a phenol novolac curing agent (“LA-7054” manufactured by DIC Corporation, MEK solution with non-volatile content of 60% by mass, phenolic hydroxyl equivalent: 124 g/eq.), and a curing accelerator, tetrabutylphosphonium decanoic acid, were added. 0.2 parts of salt (manufactured by Hokko Chemical Co., Ltd., "TBP-DA"), 120 parts of spherical silica (average particle size 0.5 μm, "SOC2" with aminosilane treatment, manufactured by Admatex), polyvinyl butyral resin solution (Sekisui Chemical Co., Ltd.) A varnish-like resin composition 1 was prepared by uniformly dispersing 2 parts of "KS-1" manufactured by Co., Ltd., a mixed solution of ethanol and toluene in a mass ratio of 1:1 with a non-volatile content of 15% by mass using a high-speed rotating mixer. .

<Production Example 2: Production of resin composition 2>
5 parts of biphenylaralkyl epoxy resin ("NC3000H" manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent: approximately 290/eq.), 10 parts of naphthalene-type epoxy resin ("HP4032SS", manufactured by DIC Corporation, epoxy equivalent: approximately 145 g/eq.), bisphenol A-type epoxy resin and bisphenol F-type epoxy resin mixture (“ZX1059” manufactured by Nippon Steel Chemical & Materials, epoxy equivalent: 165 g/eq.) 5 parts, active ester curing agent (“HPC-8150-62T” manufactured by DIC) , active group equivalent: about 229 g/eq., solid content: 61.5% by mass toluene solution) 30 parts, phenolic curing agent (DIC "LA3018-50P", active group equivalent: about 151, solid content: 50%) -Methoxypropanol solution) 5 parts, phenoxy resin (YX7553BH30 manufactured by Mitsubishi Chemical Corporation, 1:1 solution of MEK and cyclohexanone with solid content of 30% by mass), 5 parts of 4-dimethylaminopyridine (MEK solution with solid content of 5% by mass) ), 30 parts of MEK, and 80 parts of spherical silica ("SO-C2" manufactured by Admatex, average particle size 0.5 μm) surface-treated with an amine-based alkoxysilane compound ("KBM573" manufactured by Shin-Etsu Chemical Co., Ltd.) were uniformly dispersed using a mixer to prepare a varnish-like resin composition 2.

<Production Example 3: Production of resin composition 3>
35 parts of liquid bisphenol A type epoxy resin (epoxy equivalent: 180 g/eq., "jER828EL" manufactured by Mitsubishi Chemical Corporation), 35 parts of biphenyl type epoxy resin (epoxy equivalent: 290 g/eq., "NC3000H" manufactured by Nippon Kayaku Co., Ltd.), 40 parts of phenoxy resin (weight average molecular weight 38,000, "YX6954" manufactured by Mitsubishi Chemical Corporation, a 1:1 solution of MEK and cyclohexanone with a non-volatile content of 30%) was dissolved in 10 parts of MEK and 3 parts of cyclohexanone by heating with stirring. There, 45 parts of a phenol novolac curing agent (“LA-7054” manufactured by DIC Corporation, MEK solution with non-volatile content of 60% by mass, phenolic hydroxyl group equivalent: 124 g/eq.) and a curing accelerator (4-methylphenyl)tri 2 parts of phenylphosphonium thiocyanate (manufactured by Hokko Chemical Industry Co., Ltd., "TPTP-SCN" dimethylformamide (hereinafter abbreviated as "DMF") solution with non-volatile content of 10% by mass), spherical silica (average particle size 0.5 μm, aminosilane treatment) A varnish-like resin composition 3 was prepared by uniformly dispersing 75 parts of "SOC2" (manufactured by Admatex) in a high-speed rotating mixer.

[Example 1]
<Manufacture of samples for adhesion evaluation>
-Process (A)-
Resin composition 1 was uniformly applied onto a PET film (thickness: 38 μm) as a support using a die coater so that the thickness after drying was 35 μm, and the mixture was heated at 80 to 120°C (average 100°C). It was dried for 5 minutes to obtain an insulating resin film composed of a PET film and a resin composition layer.

-Process (B)-
A resin composition layer of the obtained insulating resin film was laminated on both sides of a copper-clad laminate ("R1515A" manufactured by Panasonic Corporation, total thickness of 0.8 mm) to prepare a substrate for adhesion evaluation.

Lamination was carried out using a vacuum pressure laminator MVLP-500 manufactured by Meiki Seisakusho Co., Ltd. After vacuum suction at a temperature of 100°C for 30 seconds, the lamination was carried out on the PET film under the conditions of a temperature of 100°C and a pressure of 7.0 kg/ ^cm2 . It was laminated by pressing for 30 seconds through heat-resistant rubber. Next, pressing was performed for 60 seconds at a temperature of 100° C. and a pressure of 5.5 kg/cm ² using an SUS end plate under atmospheric pressure.

-Process (C)-
The resin composition layer was thermally cured on the above substrate for adhesion evaluation using a hot air circulation furnace under the temperature and time conditions (T1) shown in the table below to form an insulating layer, and then cooled to room temperature to improve adhesion. An evaluation substrate T1 was obtained.

-Process (D)-
The substrate T1 for evaluation of adhesion was heat-treated under the temperature and time conditions (T2) shown in the table below, and then cooled to room temperature to obtain the substrate T2 for evaluation of adhesion.

-Process (E)-
(Formation of via hole)
The adhesion evaluation substrate T2 was processed using a CO ₂ laser processing machine (“LC-K212” manufactured by HITACHI) without peeling off the PET film, power: 1.35W, number of shots: 2, target top diameter: Holes were drilled at 5 locations under the condition of 50 μm. As a result, a plurality of via holes opening onto the circuit conductor of the inner layer substrate were formed, and the conductor layer of the inner layer substrate was exposed on the side surface of each via hole.

(Roughening treatment)
The PET film was peeled off, and the surface of the insulating layer was immersed in a swelling liquid, Swelling Dip Securiganth P manufactured by Atotech Japan, for 10 minutes at 60°C. It was immersed in Concentrate Compact CP manufactured by Japan Co., Ltd. at 80° C. for 15 minutes, and finally, as a neutralizing solution, it was immersed in Reduction Solution Securigant P manufactured by Atotech Japan Co., Ltd. at 40° C. for 5 minutes. Thereafter, it was dried at 80°C for 30 minutes.

(Formation of electroless plating layer)
The roughened substrate T2 for adhesion evaluation was immersed in an electroless plating solution containing PdCl ₂ and then in an electroless copper plating solution. The plating seed layer was annealed by heating at 150° C. for 30 minutes to form an electroless plating layer.

-Process (F)-
The substrate for adhesion evaluation T2 on which the electroless plating layer was formed was heat-treated under the temperature and time conditions (T3) shown in the table below, and then cooled to room temperature to obtain the substrate for adhesion evaluation T3.

-Process (G)-
The substrate T3 for adhesion evaluation was heat-treated under the temperature and time conditions (T4) shown in the table below, and then cooled to room temperature to obtain a sample for adhesion evaluation.

<Manufacture of samples for warping behavior evaluation>
In manufacturing samples for adhesion evaluation,
1) Change step (A) and step (B) to step (A) and step (B) in the production of the sample for warping behavior evaluation below,
2) Step (E) was not performed.
A sample for evaluating warping behavior was manufactured in the same manner as the sample for evaluating adhesion except for the above matters.

(Steps (A) and (B) in manufacturing samples for warping behavior evaluation)
Resin composition 1 was uniformly applied onto a PET film (thickness: 38 μm) as a support using a die coater so that the thickness after drying was 35 μm, and the mixture was heated at 80 to 120°C (average 100°C). It was dried for 5 minutes to obtain an insulating resin film composed of a PET film and a resin composition layer.

An insulating resin film was laminated on one side of a copper-clad laminate board ("MCL-E700G" manufactured by Hitachi Chemical Co., Ltd., a copper-etched board with a total thickness of 0.2 mm) to obtain a board for warping behavior evaluation.

Lamination was carried out using a vacuum pressure laminator MVLP-500 manufactured by Meiki Seisakusho Co., Ltd. After vacuum suction at a temperature of 100°C for 30 seconds, the lamination was carried out on the PET film under the conditions of a temperature of 100°C and a pressure of 7.0 kg/ ^cm2 . It was laminated by pressing for 30 seconds through heat-resistant rubber. Next, pressing was performed for 60 seconds at a temperature of 100° C. and a pressure of 5.5 kg/cm ² using an SUS end plate under atmospheric pressure.

[Examples 2, 7, Comparative Example 7]
In Example 1, resin composition 1 was changed to resin composition 2, and conditions T1 to T4 were also changed. A sample for evaluating adhesion and a sample for evaluating warpage behavior were manufactured in the same manner as in Example 1 except for the above matters.

[Example 3]
In Example 1, resin composition 1 was changed to resin composition 3, and conditions T1 to T4 were also changed. A sample for evaluating adhesion and a sample for evaluating warpage behavior were manufactured in the same manner as in Example 1 except for the above matters.

[Example 4]
In Example 1, step (D) was not performed. A sample for evaluating adhesion and a sample for evaluating warpage behavior were manufactured in the same manner as in Example 1 except for the above matters.

[Example 5]
In Example 2, step (D) was not performed. A sample for evaluating adhesion and a sample for evaluating warpage behavior were manufactured in the same manner as in Example 2 except for the above matters.

[Example 6]
In Example 3, step (D) was not performed. A sample for evaluating adhesion and a sample for evaluating warpage behavior were manufactured in the same manner as in Example 3 except for the above matters.

[Examples 8 and 9, Comparative Examples 8 and 9]
In Example 2, step (D) was not performed and conditions T3 and T4 were further changed. A sample for evaluating adhesion and a sample for evaluating warpage behavior were manufactured in the same manner as in Example 2 except for the above matters.

[Comparative example 1]
In Example 1, step (G) was not performed. A sample for evaluating adhesion and a sample for evaluating warpage behavior were manufactured in the same manner as in Example 1 except for the above matters.

[Comparative example 2]
In Example 2, step (G) was not performed. A sample for evaluating adhesion and a sample for evaluating warpage behavior were manufactured in the same manner as in Example 2 except for the above matters.

[Comparative example 3]
In Example 3, step (G) was not performed. A sample for evaluating adhesion and a sample for evaluating warpage behavior were manufactured in the same manner as in Example 3 except for the above matters.

[Comparative example 4]
In Example 1, step (F) and step (G) were not performed. A sample for evaluating adhesion and a sample for evaluating warpage behavior were manufactured in the same manner as in Example 1 except for the above matters.

[Comparative example 5]
In Example 2, step (F) and step (G) were not performed. A sample for evaluating adhesion and a sample for evaluating warpage behavior were manufactured in the same manner as in Example 2 except for the above matters.

[Comparative example 6]
In Example 3, step (F) and step (G) were not performed. A sample for evaluating adhesion and a sample for evaluating warpage behavior were manufactured in the same manner as in Example 3 except for the above matters.

[Evaluation of adhesion]
After an accelerated test (130°C, 85% RH, 100 hours) of the samples for adhesion evaluation prepared in each example and each comparative example, the samples for adhesion evaluation were placed in via holes using FIB (focused ion beam). It was cut out with a cross section that included the diameter of. Adhesion was evaluated by observing the cut cross section using an electron microscope and evaluating the area where delamination occurred based on the following criteria.
〇: Length of delamination is less than 5 μm △: Length of delamination is 5 μm or more and less than 10 μm ×: Length of delamination is 10 μm or more

[Evaluation of warpage]
The warp behavior of the samples for evaluating warp behavior produced in each of the Examples and Comparative Examples was measured using a shadow moire device (TherMoire AXP manufactured by Akrometrix), and evaluated based on the following criteria.
〇: Warping behavior is 3.5 mm or less △: Warping behavior is more than 3.5 mm and less than 7 mm ×: Warping behavior is 7 mm or more

It can be seen that Examples 1 to 9, in which step (F) and step (G) were performed under predetermined temperature conditions, were excellent in both the evaluation of warpage behavior and the evaluation of adhesion of the conductor layer. Further, in Examples 1 to 9, the content of the inorganic filler is 40% by mass or more and 80% by mass or less when the nonvolatile component of the resin composition is 100% by mass, so that the coefficient of thermal expansion is low. confirmed.

On the other hand, Comparative Examples 1 to 9 were inferior to Examples 1 to 9 in at least one of the evaluation of warping behavior and the evaluation of adhesion of the conductor layer, and the importance of steps (F) and (G) was It has been shown. In addition, "content of inorganic filler (mass %)" in the table represents the content when the nonvolatile component of the resin composition is 100 mass %.

In Examples 1 to 9, it was confirmed that even when the thermoplastic resin and the curing accelerator were not contained, the same results as in the above-mentioned Examples were obtained, although there were differences in degree.

Claims (7)

(A) preparing an insulating resin film including a support and a resin composition layer formed of a resin composition provided on the support;
(B) a step of laminating an insulating resin film on the inner layer substrate so that the resin composition layer is bonded to the inner layer substrate;
(C) a step of thermosetting the resin composition layer to form an insulating layer;
(E) forming a via in the insulating layer and further forming a conductor layer on the insulating layer;
(F) a step of heating the insulating layer at a temperature of 175° C. or more and 205° C. or less, and (G) a step of heating the insulating layer at a temperature of 110° C. or more and less than 175° C., in this order,
The resin composition includes an epoxy resin, a curing agent, and an inorganic filler,
The content of the inorganic filler is 40% by mass or more and 80% by mass or less, when the nonvolatile components of the resin composition are 100% by mass,
A method for manufacturing a circuit board that satisfies 20°C≦T3−T4≦70°C, where the heating temperature in step (F) is T3 (°C) and the heating temperature in step (G) is T4 (°C). After step (C) and before step (E),
The method for manufacturing a circuit board according to claim 1, comprising the step of: (D) heating the insulating layer. The method for manufacturing a circuit board according to claim 2, wherein the heating temperature T2 in step (D) is 100°C or more and 150°C or less. After step (F) and before step (G),
The method for manufacturing a circuit board according to any one of claims 1 to 3, further comprising the step of (F-1) cooling the insulating layer. The method for manufacturing a circuit board according to any one of claims 1 to 4, wherein the heating time in step (F) is 10 minutes or more. The method for manufacturing a circuit board according to any one of claims 1 to 5, wherein the heating time in step (G) is 10 minutes or more. The method for manufacturing a circuit board according to any one of claims 1 to 6, wherein the heating temperature T1 in step (C) is 100°C or more and 190°C or less.