WO2022034871A1

WO2022034871A1 - Copper foil with resin layer and laminate using same

Info

Publication number: WO2022034871A1
Application number: PCT/JP2021/029458
Authority: WO
Inventors: 晃樹小松; 慎也喜多村; 憲明杉本; 洋介松山; 豪志信國
Original assignee: 三菱瓦斯化学株式会社; Ｍｇｃエレクトロテクノ株式会社
Priority date: 2020-08-13
Filing date: 2021-08-07
Publication date: 2022-02-17
Also published as: CN116075557A; KR20230050341A; TW202216441A; JPWO2022034871A1

Abstract

[Problem] To provide a copper foil with a resin layer capable of improving smear removal and capable of suppressing overhang. [Solution] The copper foil with a resin layer 10 has a copper foil 11, a first resin layer 12 laminated on the copper foil 11, and a second resin layer 13 laminated on the first resin layer 12. The first resin layer 12 is composed of a first resin composition that includes a thermosetting resin (A1) and does not include an inorganic filler or a first resin composition that includes a thermosetting resin (A1) and an inorganic filler (B1), in which the content of the inorganic filler (B1) is 15 vol% or less. The second resin layer 13 is composed of a second resin composition that includes a thermosetting resin (A2) and an inorganic filler (B2), in which the content of the inorganic filler (B2) is from 15 vol% to 35 vol%.

Description

Copper foil with resin layer and laminate using this

The present invention relates to a copper foil with a resin layer and a laminated body using the same. More specifically, the present invention relates to a copper foil with a resin layer useful for a printed wiring board or a substrate for mounting a semiconductor element, and a laminate using the same.

In recent years, printed wiring boards or substrates for mounting semiconductor elements, which are widely used in electronic devices, communication devices, personal computers, etc., have been increasing in density, becoming more integrated, and becoming thinner. Along with this, as a method for manufacturing a printed wiring board or a substrate for mounting a semiconductor element, a build-up method in which circuit-formed conductor layers and insulating layers (interlayer insulating layers) are alternately stacked is widely used, and wiring is used. A semi-additive method that can form a fine pattern is often used for forming a pattern.

As an insulating layer used for such a printed wiring board, a multi-layered resin composition layer is known (see, for example, Patent Document 1). Patent Document 1 solves the problem that a step is generated in the via hole of each layer during laser processing and the shape of the via hole becomes distorted by adjusting the etching amount of each of the multi-layered layers. As described above, development for obtaining a good processed shape for the via hole has been promoted conventionally.

Japanese Unexamined Patent Publication No. 2017-50561

However, for example, the required characteristics are different between the case of forming a via hole by conformal laser processing and the case of forming a via hole by direct laser processing, and a good processed shape can be obtained by both processing methods. The development of materials was required. For example, in the case of conformal laser processing, it is required to have high smear removing property, and in the case of direct laser processing, it is required to suppress overhang and the like. Patent Document 1 does not solve these problems, and its specific configuration is different from that of the present invention.

The present invention has been made based on such a problem, and is a copper foil with a resin layer capable of enhancing smear removal property and suppressing overhang, and a laminated body using the same. The purpose is to provide.

The present inventors have a copper foil with a resin layer having a copper foil, a first resin layer laminated on the copper foil, and a second resin layer laminated on the first resin layer. , The above-mentioned problems can be solved by adjusting the ratio of the inorganic filler in the first resin layer and the second resin layer, and the present invention has been completed.

That is, the present invention is as follows.
[1]
A copper foil with a resin layer having a copper foil, a first resin layer laminated on the copper foil, and a second resin layer laminated on the first resin layer.
The first resin layer is a first resin composition containing a thermosetting resin (A1) and not containing an inorganic filler, or a thermosetting resin (A1) and an inorganic filler (B1). The second resin layer comprises a first resin composition containing 15% by volume or less of the inorganic filler (B1), and the second resin layer contains a thermosetting resin (A2) and an inorganic filler (B2). A copper foil with a resin layer, comprising a second resin composition containing the inorganic filler (B2) having a content of 15% by volume or more and 35% by volume or less.
[2]
The total content of the inorganic filler (B1) and the inorganic filler (B2) with respect to the total of the first resin composition and the second resin composition is 2.5% by volume or more 33. The copper foil with a resin layer according to [1], which is 3% by volume or less.
[3]
The copper foil with a resin layer according to [1], wherein the thickness of the first resin layer is 1 μm or more and 5 μm or less.
[4]
The copper foil with a resin layer according to [1], wherein the thickness of the second resin layer is 1 μm or more and 10 μm or less.
[5]
The thermosetting resin (A1) includes a polyimide resin, a liquid crystal polyester, an epoxy compound, a cyanate ester compound, a maleimide compound, a phenol compound, a polyphenylene ether compound, a benzoxazine compound, an organic group-modified silicone compound, and a non-polymerizable resin. The copper foil with a resin layer according to [1], which contains at least one selected from the group consisting of compounds having a saturated group.
[6]
The thermosetting resin (A2) is composed of an epoxy compound, a cyanate ester compound, a maleimide compound, a phenol compound, a polyphenylene ether compound, a benzoxazine compound, an organic group-modified silicone compound, and a compound having a polymerizable unsaturated group. The copper foil with a resin layer according to [1], which contains at least one selected from the above group.
[7]
The inorganic filler (B1) and the inorganic filler (B2) are at least one selected from magnesium hydroxide, magnesium oxide, silica, molybdenum compound, alumina, aluminum nitride, glass, talc, titanium compound, and zirconium oxide. The copper foil with a resin layer according to [1], which is contained.
[8]
A laminate having a conductor layer and a build-up layer formed by using the copper foil with the resin layer according to [1].

According to the present invention, in the formation of via holes, it is possible to improve the smear removal property while suppressing the generation of cracks, and it is possible to suppress overhang. Therefore, it is possible to obtain a good processing shape in both the conformal laser processing and the direct laser processing.

It is a schematic diagram which shows the structure of the copper foil with a resin layer which concerns on one Embodiment of this invention. It is a schematic diagram which shows an example of the laminated body which concerns on one Embodiment of this invention. It is a schematic diagram which shows an example of the multilayer coreless substrate which concerns on one Embodiment of this invention.

Hereinafter, embodiments for carrying out the present invention (hereinafter referred to as “the present embodiment”) will be described in detail, but the present invention is not limited thereto, and various modifications are made without departing from the gist thereof. Is possible. In the present specification, the laminated bodies are those in which the layers are adhered to each other, but the layers may be peelable from each other, if necessary.

In the present embodiment, the “resin solid content” refers to the components of the first resin layer 12 or the second resin layer 13 excluding the solvent and the inorganic filler, unless otherwise specified, and refers to the “resin solid content”. "100 parts by mass" means that the total of the components of the first resin layer 12 or the second resin layer 13 excluding the solvent and the inorganic filler is 100 parts by mass.

[Copper foil with resin layer]
FIG. 1 shows the configuration of a copper foil 10 with a resin layer according to an embodiment of the present invention. The copper foil 10 with a resin layer includes a copper foil 11, a first resin layer 12 laminated on the copper foil 11, and a second resin layer 13 laminated on the first resin layer 12. It is equipped with.

The copper foil 10 with a resin layer is useful, for example, as a material for forming an insulating layer provided on a circuit pattern (conductor layer), and is used, for example, in the manufacture of electronic devices, communication devices, personal computers, and the like. It can be used as a material for forming an insulating layer of a printed wiring board or a substrate for mounting a semiconductor element. For example, when manufacturing a printed wiring board or the like, a copper foil 10 with a resin layer is arranged on a substrate on which a conductor layer such as a circuit pattern is formed so that the second resin layer 13 and the conductor layer are in contact with each other. After that, the first resin layer 12 and the second resin layer 13 are cured by heating and pressing (pressing) to form an insulating layer on the conductor layer.

The second resin layer 13 is a layer containing a resin having fluidity at the time of press processing, and is a layer in which uneven portions such as a conductor layer of a circuit pattern are embedded. In order to maintain the insulating property between the conductor layer embedded in the second resin layer 13 and the copper foil 11, the first resin layer 12 may be formed with the copper foil 11 even after a press treatment such as when forming a laminate. It is a layer that maintains a distance from the second resin layer 13. Since the second resin layer 13 functions as an embedded layer, it is preferable that at least one of the constituent components and physical properties is different from that of the first resin layer 12. Although not particularly limited, for example, as an embodiment in which the first resin layer 12 and the second resin layer 13 are different, the first resin layer 12 is a polyimide resin and the second resin layer 13 is an epoxy compound. The first resin layer 12 can be obtained by changing the composition ratio of the components contained in each layer or the cured state (for example, by changing the coating conditions of each layer). The physical properties are different depending on (such as completely curing the second resin layer 13 to make the second resin layer 13 in a semi-cured state), and there are cases where these are combined.

[Copper foil]
The copper foil 11 may be any one used for ordinary printed wiring boards, and examples thereof include electrolytic copper foil, rolled copper foil, and copper alloy film. The copper foil 11 may be subjected to known surface treatments such as matte treatment, corona treatment, nickel treatment and cobalt treatment. As the copper foil 11 in the present embodiment, commercially available products can be used, for example, "GHY5" (trade name, 12 μm thick copper foil) and "JXUT-I" (trade name, 1) manufactured by JX Nippon Mining & Metals Co., Ltd. .5 μm thick copper foil), “MT-FL” (trade name, 3 μm thick copper foil), “3EC-VLP” (trade name, 12 μm thick copper foil), “3EC-III” manufactured by Mitsui Kinzoku Mining Co., Ltd. (Product name, 12 μm thick copper foil) and “3EC-M2S-VLP” (trade name, 12 μm thick copper foil), and copper foil “GTS-MP” (trade name, 12 μm thickness) manufactured by Furukawa Denki Kogyo Co., Ltd. Copper foil) can be mentioned.

The arithmetic mean roughness (Ra) of the copper foil surface is usually 0.05 μm to 2 μm because it can improve the adhesion strength between the copper foil 11 and the first resin layer 12 and prevent peeling during long-term use. It is preferably in the range of 0.08 μm to 1.7 μm, and more preferably in the range of 0.2 μm to 1.6 μm from the viewpoint that better adhesion can be obtained. .. The arithmetic mean roughness can be measured using a commercially available shape measuring microscope (laser microscope, for example, "VK-1000" (trade name) manufactured by KEYENCE CORPORATION).

The thickness of the copper foil 11 is not particularly limited, but is preferably in the range of 1 μm to 18 μm in consideration of the surface roughening treatment, and a thin printed wiring board and a substrate for mounting a semiconductor element can be preferably obtained. It is more preferably in the range of 2 μm to 15 μm.

[First resin layer]
The first resin layer 12 contains a first resin composition containing a thermosetting resin (A1) and no inorganic filler, or a thermosetting resin (A1) and an inorganic filler (B1). It is composed of a first resin composition containing 15% by volume or less of the inorganic filler (B1). That is, the first resin layer 12 does not contain an inorganic filler, or even if it contains an inorganic filler, the content is 15% by volume or less. When the inorganic filler is added, the processability is improved, but when the content exceeds 15% by volume, it becomes difficult to obtain a good processed shape due to the relationship with the second resin layer 13. Further, it is more preferable that the first resin composition does not contain an inorganic filler, or even if it contains an inorganic filler, the content is less than 5% by volume. By using the above composition, the copper foil adhesion and wiring formability can be improved. In addition, it is possible to suppress the occurrence of overhang in the hole drilling by the direct laser. The content of the inorganic filler (B1) is the content of the inorganic filler (B1) with respect to the first resin composition (inorganic filler (B1) / first resin composition × 100). ..

The thickness of the first resin layer 12 is not particularly limited, but is preferably 5 μm or less from the viewpoint of thinning, and is preferably 1 μm or more in consideration of ensuring insulation. The first resin layer 12 may be in a semi-cured state (B-Stage) or a completely cured state (C-Stage). The first resin layer 12 can be formed by a known means such as coating by using, for example, the first resin composition. The first resin composition may contain other additives described later, if necessary.

<Thermosetting resin (A1)>
The thermosetting resin (A1) is not particularly limited, and is, for example, a polyimide resin, a liquid crystal polyester, an epoxy compound, a cyanate ester compound, a maleimide compound, a phenol compound, a polyphenylene ether compound, a benzoxazine compound, and an organic group modification. Examples thereof include a silicone compound and a compound having a polymerizable unsaturated group. The thermosetting resin (A1) can be used by appropriately mixing one or more of these. Above all, it is preferable to include at least one of the polyimide resin and the liquid crystal polyester because the thickness reduction rate can be lowered. Further, it is preferable to include an epoxy compound and a phenol compound in addition to the polyimide resin or the liquid crystal polyester because excellent peel strength and adhesion to the second resin layer 13 can be obtained. It is more preferable to include the compound.

-Polyimide resin-
As the polyimide resin, a commercially available product can be appropriately selected and used. For example, a solvent-soluble polyimide resin synthesized by the production method described in JP-A-2005-15629 can also be used. Specifically, the solvent-soluble polyimide resin includes an aliphatic tetracarboxylic acid dianhydride represented by the following formula (1), an aliphatic tetracarboxylic acid represented by the following formula (2), and the aliphatic tetracarboxylic acid. It can be obtained by polycondensing one or more selected from acid derivatives and one or more diamine compounds in a solvent in the presence of a tertiary amine compound.

(In the formula, R is a tetravalent aliphatic hydrocarbon group having 4 to 16 carbon atoms.)

(In the formula, R is a tetravalent aliphatic hydrocarbon group having 4 to 16 carbon atoms, and Y ₁ to Y ₄ are independently hydrogen or a hydrocarbon group having 1 to 8 carbon atoms.)

In the above-mentioned production method, a substantially equal molar amount of the aliphatic tetracarboxylic acid and the diamine compound can be heated in a solvent in the presence of a tertiary amine compound and polycondensed. The reaction molar ratio of the aliphatic tetracarboxylic acids and the diamine compound is preferably in the range of 95 to 105 mol% with respect to one of them.

In the production of a general polyimide resin, tetracarboxylic acid dianhydride is usually used as the tetracarboxylic acid, but in the above production method, in addition to the aliphatic tetracarboxylic acid dianhydride, the aliphatic tetra is used. A practical polyimide resin can be produced by using an ester of a carboxylic acid or an aliphatic tetracarboxylic acid and an alcohol. If the aliphatic tetracarboxylic acid can be used as it is, it is advantageous in terms of production equipment and cost.
Examples of the aliphatic tetracarboxylic acid dianhydride represented by the formula (1) include 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride and 1,2,4,5-cyclopentanetetra. Carboxylic acid dianhydride, 1,2,4,5-cyclohexanetetracarboxylic acid dianhydride, Bicyclo [2.2.2] Oct-7-en-2,3,5,6-tetracarboxylic acid dianhydride And so on.
Further, examples of the aliphatic tetracarboxylic acid represented by the formula (2) and its derivatives include 1,2,3,4-cyclobutanetetracarboxylic acid and 1,2,4,5-cyclopentanetetracarboxylic acid. , 1,2,4,5-Cyclohexanetetracarboxylic acid, bicyclo [2.2.2] octo-7-en-2,3,5,6-tetracarboxylic acid, etc., and their alcohol esters. Can be done. These can be used alone or in admixture of two or more. Of these, 1,2,4,5-cyclohexanetetracarboxylic dianhydride and 1,2,4,5-cyclohexanetetracarboxylic acid are preferred.

In the above-mentioned production method, other tetracarboxylic dians and derivatives thereof can be mixed and used as long as the solvent solubility is not impaired. For example, pyromellitic acid, 3,3', 4,4'-biphenyltetracarboxylic acid, 2,3,3', 4'-biphenyltetracarboxylic acid, 2,2-bis (3,4-dicarboxyphenyl). Propane, 2,2-bis (2,3-dicarboxyphenyl) propane, 2,2-bis (3,4-dicarboxyphenyl) -1,1,1,3,3,3-hexafluoropropane, 2 , 2-bis (2,3-dicarboxyphenyl) -1,1,1,3,3,3-hexafluoropropane, bis (3,4-dicarboxyphenyl) sulfone, bis (3,4-dicarboxyphenyl) Phenyl) ether, bis (2,3-dicarboxyphenyl) ether, 3,3', 4,4'-benzophenone tetracarboxylic acid, 2,2', 3,3'-benzophenone tetracarboxylic acid, 4,4- (P-Phenylenedoxy) diphthalic acid, 4,4- (m-Phenylenedoxy) diphthalic acid, ethylenetetracarboxylic acid, 3-carboxymethyl-1,2,4-cyclopentantricarboxylic acid, 1,1-bis Examples thereof include (2,3-dicarboxyphenyl) ethane, bis (2,3-dicarboxyphenyl) methane, bis (3,4-dicarboxyphenyl) methane, and derivatives thereof. The proportion of these other tetracarboxylic acid components is preferably less than 50 mol% of the total tetracarboxylic acid components.

The diamine compound is preferably an aromatic diamine compound containing 6 to 28 carbon atoms or an aliphatic diamine compound containing 2 to 28 carbon atoms. Examples of the diamine compound include p-phenylenediamine, m-phenylenediamine, 4,4'-diaminobiphenyl, 4,4'-diamino-2,2'-dimethylbiphenyl, and 4,4'-diamino-3,3. '-Dimethylbiphenyl, 4,4'-diamino-2,2'-ditrifluoromethylbiphenyl, 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylmethane, 4,4' -Diaminobenzophenone, 4,4'-diaminodiphenylsulfone, 4,4'-diaminodiphenylsulfide, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 4, 4'-bis (4-aminophenoxy) biphenyl, bis [4- (4-aminophenoxy) phenyl] sulfone, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [ 4- (4-Aminophenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane, bis [4- (3-aminophenoxy) phenyl] sulfone, 9,9-bis (4-amino) Aromatic diamine compounds such as phenyl) fluorene, ethylenediamine, hexamethylenediamine, polyethylene glycol bis (3-aminopropyl) ether, polypropylene glycol bis (3-aminopropyl) ether, 1,3-bis (aminomethyl) cyclohexane, 1 , 4-Bis (Aminomethyl) Cyclohexane, 4,4'-Diaminodicyclohexylmethane, 3 (4), 8 (9) -Bis (Aminomethyl) -Tricyclo [5.2.2.102,6] Decane, Meta Examples thereof include aliphatic diamine compounds such as xylylene diamine, paraxylylene diamine, isophorone diamine, norbornan diamine and siloxane diamines. These can be used alone or in admixture of two or more. Among these diamine compounds, aromatic diamine compounds are 4,4'-diamino-3,3'-dimethylbiphenyl, 4,4'-diamino-2,2'-ditrifluoromethylbiphenyl, 4,4'-diamino. Diphenyl ether, 4,4'-diaminodiphenylmethane, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 4,4'-bis (4-aminophenoxy) biphenyl, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane Of the aliphatic diamine compound, 4,4'-diaminodicyclohexylmethane, 3 (4), 8 (9) -bis (aminomethyl) -tricyclo [5.2.1.02,6] decane are preferable.

In the above-mentioned production method, it is preferable to use 0.001 to 1.0 mol of the tertiary amine compound with respect to 1 mol of the aliphatic tetracarboxylic acid component to be used, and it is more preferable to use 0.01 to 0.2 mol of the tertiary amine compound. ..

Examples of the tertiary amine compound include trimethylamine, triethylamine, tripropylamine, tributylamine, triethanolamine, N, N-dimethylethanolamine, N, N-diethylethanolamine, triethylenediamine, N-methylpyrrolidin, and N. -Ethylpyrolidin, N-methylpiperidine, N-ethylpiperidine, imidazole, pyridine, quinoline, isoquinoline and the like can be mentioned. Of these tertiary amine compounds, triethylamine is particularly preferred.

Examples of the solvent used in the above-mentioned production method include γ-butyrolactone, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N, N-dimethylformamide, dimethyl sulfoxide, hexamethylphosphoramide, and tetramethylene sulfone. , P-Chlorphenol, m-Cresol, 2-Chlor-4-hydroxytoluene and the like. These can be used alone or in admixture of two or more. Of these, γ-butyrolactone, N, N-dimethylacetamide and N-methyl-2-pyrrolidone are preferable, and γ-butyrolactone and N, N-dimethylacetamide are even more preferable. Further, a poor solvent of the polyimide resin can be used in combination to the extent that the polymer does not precipitate. Examples of the poor solvent include hexane, heptane, benzene, toluene, xylene, chlorbenzene, o-dichlorobenzene and the like.
As for the amount of the solvent used in the production method, the total weight of the aliphatic tetracarboxylic acid component and the diamine component is preferably 1 to 50% by mass, more preferably 20 to 45% by mass with respect to the total mass of the reaction solution.

The method of charging the aliphatic tetracarboxylic acid component and the diamine compound component is not particularly limited, and the method of charging both components at once or in a solution containing either component (it does not have to be completely dissolved) is already used. A method of gradually charging one of the components in a solid state or a solution state can be performed. In particular, the method of charging both components at once is advantageous in terms of productivity because the charging time can be shortened.

It is preferable to charge the tertiary amine compound by raising the temperature and reaching the target temperature in order to fully exert its catalytic effect. In particular, it is preferable to charge the solvent, the aliphatic tetracarboxylic acid component, and the diamine compound at the same time.

The method for charging the solvent is also not particularly limited, and a method of charging in advance into a reaction vessel, a method of charging into a reaction vessel in which either one or both of an aliphatic tetracarboxylic acid component or a diamine compound is present, and an aliphatic tetra A method in which either the carboxylic acid component or the diamine component is dissolved in advance and then charged into the reaction vessel can be carried out alone or in combination. Further, the solvent as described above may be added to the solvent-soluble polyimide resin solution in the state during the reaction, in the state of staying in the reaction tank after the reaction, or in the state of being taken out from the reaction tank after the reaction, depending on the purpose. can.

Further, as the polyimide resin used in this embodiment, for example, a block copolymer polyimide resin can be used. Examples of such a block copolymer polyimide resin include the block copolymer polyimide resin described in International Publication No. WO2010-073952. Specifically, the block copolymer polyimide resin is composed of a structure A in which an imide oligomer composed of a second structural unit is bonded to the end of an imide oligomer composed of a first structural unit, and a second structural unit. The copolymerized polyimide resin is not particularly limited as long as it has a structure in which the structure B in which the imide oligomer composed of the first structural unit is bonded to the end of the imide oligomer is alternately repeated. The second structural unit is different from the first structural unit. These block copolymerized polyimide resins are obtained by reacting a tetracarboxylic acid dianhydride with a diamine in a polar solvent to form an imide oligomer, and then further diamine or another tetracarboxylic acid with the tetracarboxylic acid dianhydride. It can be synthesized by a step-growth polymerization reaction in which acid dianhydride and diamine are added and imidized.

In the present embodiment, when the polyimide resin is used for the first resin layer 12, the content thereof is not particularly limited, but from the viewpoint of heat resistance and curability, the resin solid content of the first resin layer 12 is 100 parts by mass. On the other hand, the range of 10 to 90 parts by mass is preferable, and the range of 30 to 80 parts by mass is particularly preferable.

-Liquid crystal polyester-
The liquid crystal polyester is an aromatic polyester that exhibits liquid crystal properties when melted. As the liquid crystal polyester, a known one can be appropriately selected and used. As the known liquid crystal polyester, for example, the aromatic polyester described in JP-A-2001-11296 can be used. Specific examples thereof include aromatic polyesters containing 90 mol% or more of the following structural unit (3).

As the aromatic polyester containing the structural unit (3) described above, for example, polyoxybenzoate, which is a homopolymer of the structural unit (3), can be used from the viewpoint of availability. As a method for producing the aromatic polyester, a known method can be adopted. The aromatic polyester containing the above-mentioned structural unit (3) is often sparingly or insoluble in a normal solvent, and is sparingly or insoluble, so that it does not exhibit liquid crystallinity. Therefore, the aromatic polyester containing the above-mentioned structural unit (3) is preferably used as a powder. The powder is obtained by pulverizing an aromatic polyester resin or fiber, and the particle size is preferably not more than the thickness of the first resin layer 12, and is preferably not more than, for example, 5 μm.

Although not particularly limited, the molecular weight of the liquid crystal polyester is usually 1000 to 100,000, preferably 10,000 to 50,000.

As the liquid crystal polyester, a commercially available product can be appropriately selected and used, and for example, "Econol E101-F" manufactured by Sumitomo Chemical Co., Ltd. can be used. In the present embodiment, when the liquid crystal polyester is used for the first resin layer 12, the content thereof is not particularly limited, but from the viewpoint of heat resistance and curability, the resin solid content of the first resin layer 12 is 100 parts by mass. On the other hand, the range of 10 to 90 parts by mass is preferable, and the range of 30 to 80 parts by mass is particularly preferable.

-Epoxy compound-
The epoxy compound has 1 or more (preferably 2 to 12, more preferably 2 to 6, still more preferably 2 to 4, more preferably 2 or 3, even more preferably 2) epoxy groups in one molecule. The compound or resin is not particularly limited, and any conventionally known epoxy compound can be used. The epoxy equivalent of the epoxy compound is preferably 250 g / eq to 850 g / eq, more preferably 250 g / eq to 450 g / eq, from the viewpoint of improving the adhesiveness and flexibility. The epoxy equivalent can be measured by a conventional method.

Specific examples of the epoxy compound include polyoxynaphthylene type epoxy resin, biphenyl aralkyl type epoxy resin, naphthalene tetrafunctional epoxy resin, xylene type epoxy resin, naphthol aralkyl type epoxy resin, bisphenol A type epoxy resin, and bisphenol F. Type epoxy resin, bisphenol A novolak type epoxy resin, trifunctional phenol type epoxy resin, tetrafunctional phenol type epoxy resin, naphthalene type epoxy resin, biphenyl type epoxy resin, aralkylnovolac type epoxy resin, alicyclic epoxy resin, polyol type epoxy Examples thereof include a resin, a glycidylamine type epoxy resin, a glycidyl ester type epoxy resin, a compound obtained by epoxidizing a double bond such as butadiene, and a compound obtained by reacting a hydroxyl group-containing silicone resin with epichlorohydrin. Among these, polyoxynaphthylene type epoxy resin, biphenyl aralkyl type epoxy resin, naphthalene tetrafunctional epoxy resin, xylene type epoxy resin, and naphthol aralkyl type epoxy resin are particularly from the viewpoint of adhesiveness to plated copper and flame retardancy. Is preferable. These epoxy compounds may be used alone or in admixture of two or more.

In the present embodiment, when the epoxy compound is used for the first resin layer 12, the content thereof is not particularly limited, but from the viewpoint of heat resistance and curability, the resin solid content of the first resin layer 12 is 100 parts by mass. On the other hand, the range of 1 to 60 parts by mass is preferable, and the range of 1 to 30 parts by mass is particularly preferable.

-Cyanic acid ester compound-
The cyanic acid ester compound has excellent chemical resistance, adhesiveness, and the like, and the excellent chemical resistance makes it possible to form a uniform roughened surface. Therefore, the resin layer in the present embodiment. Can be suitably used as a component of.

The cyanate ester compound has one or more cyanate groups (cyanato groups) in the molecule (preferably 2 to 12, more preferably 2 to 6, still more preferably 2 to 4, more preferably 2 or 3, still more preferably. 2) The compound is not particularly limited as long as it is contained, and a compound usually used in the field of printed wiring board can be widely used. Specific examples of the cyanate ester compound include, for example, an α-naphthol aralkyl type cyanate ester compound represented by the formula (4), a phenol novolac type cyanate ester compound represented by the formula (5), and a formula (6). Biphenyl aralkyl type cyanic acid ester compound, naphthylene ether type cyanic acid ester compound, xylene resin type cyanic acid ester compound, trisphenol methane type cyanic acid ester compound, adamantan skeleton type cyanic acid ester compound, bisphenol M type cyanide. At least one selected from the group consisting of an acid ester compound, a bisphenol A type cyanate ester compound, and a diallyl bisphenol A type cyanate ester compound can be mentioned. Among these, from the viewpoint of further improving low water absorption, the α-naphthol aralkyl type cyanate ester compound represented by the formula (4), the phenol novolac type cyanate ester compound represented by the formula (5), and the formula Biphenyl aralkyl type cyanate ester compound represented by (6), naphthylene ether type cyanate ester compound, xylene resin type cyanate ester compound, bisphenol M type cyanate ester compound, bisphenol A type cyanate ester compound, and diallyl. It is preferably at least one selected from the group consisting of the bisphenol A type cyanate ester compound. These cyanate ester compounds may be prepared by a known method, or commercially available products may be used.

Among these, the α-naphthol aralkyl type cyanate ester compound represented by the formula (4), the phenol novolac type cyanate ester compound represented by the formula (5), and the biphenyl aralkyl type represented by the formula (6). Cyanic acid ester compounds are preferable because they have excellent flame retardancy, high curability, and a low thermal expansion coefficient of the cured product.

In formula (4), R ¹ represents a hydrogen atom or a methyl group, and n ¹ represents an integer of 1 or more. n ¹ is preferably an integer of 1 to 50. )

In formula (5), R ² represents a hydrogen atom or a methyl group, and n ² represents an integer of 1 or more. n ² is preferably an integer of 1 to 50.

In formula (6), R ³ represents a hydrogen atom or a methyl group, and n ³ represents an integer of 1 or more. n ³ is preferably an integer of 1 to 50.

In the present embodiment, when the cyanic acid ester compound is used for the first resin layer 12, the content thereof is not particularly limited, but from the viewpoint of heat resistance and adhesion to the copper foil, the first resin layer 12 has a content thereof. The range of 1 to 60 parts by mass is preferable, and the range of 1 to 30 parts by mass is more preferable with respect to 100 parts by mass of the resin solid content.

-Maleimide compound-
Since the maleimide compound can improve the hygroscopic heat resistance of the insulating resin layer, it can be suitably used as a component of the resin layer in the present embodiment. The maleimide compound has 1 or more (preferably 2 to 12, more preferably 2 to 6, still more preferably 2 to 4, more preferably 2 or 3, even more preferably 2) maleimide groups in one molecule. The compound is not particularly limited, and any conventionally known maleimide compound can be used.

Specific examples of the maleimide compound include, for example, bis (4-maleimidephenyl) methane, 2,2-bis {4- (4-maleimidephenoxy) -phenyl} propane, and bis (3,5-dimethyl-4-maleimidephenyl). ) Bismaleimide compounds such as methane, bis (3-ethyl-5-methyl-4-maleimidephenyl) methane, bis (3,5-diethyl-4-maleimidephenyl) methane; polyphenylmethane maleimide. In addition, it is also possible to blend in the form of a prepolymer of these maleimide compounds, or a prepolymer of a maleimide compound and an amine compound. These maleimide compounds may be used alone or in admixture of two or more.

Among these, bismaleimide compounds are preferable from the viewpoint of heat resistance, and among them, 2,2-bis [4- (4-maleimidephenoxy) phenyl] propane and bis (3-ethyl-5-methyl-4-maleimidephenyl) are preferable. Methane is more preferred.

In the present embodiment, when the maleimide compound is used for the first resin layer 12, the content thereof is not particularly limited, but from the viewpoint of heat resistance and adhesion to the copper foil, the resin solid of the first resin layer 12 is used. The range of 5 to 75 parts by mass is preferable, and the range of 5 to 45 parts by mass is more preferable with respect to 100 parts by mass.

-Phenol compound-
The phenolic compound includes 1 or more (preferably 2 to 12, more preferably 2 to 6, still more preferably 2 to 4, more preferably 2 or 3, even more preferably 2) phenolic hydroxy groups in one molecule. The phenol compound is not particularly limited as long as it has, and any conventionally known phenol compound can be used. Specific examples of the phenol compound include, for example, bisphenol A type phenol resin, bisphenol E type phenol resin, bisphenol F type phenol resin, bisphenol S type phenol resin, phenol novolac resin, bisphenol A novolak type phenol resin, and glycidyl ester type phenol resin. , Aralkirnobolak phenol resin, Biphenylaralkyl typephenol resin, Cresolnovolak typephenol resin, Polyfunctional phenol resin, Naftor resin, Naftornovolak resin, Polyfunctional naphthol resin, Anthracene type phenol resin, Naphthalene skeleton-modified Novorak type phenol resin, Phenol Aralkir Examples thereof include type phenol resin, naphthol aralkyl type phenol resin, dicyclopentadiene type phenol resin, biphenyl type phenol resin, alicyclic phenol resin, polyol type phenol resin, phosphorus-containing phenol resin, hydroxyl group-containing silicone resin and the like. These phenol compounds can be used alone or in admixture of two or more.

-Polyphenylene ether compound-
The polyphenylene ether compound according to this embodiment is a compound represented by the general formula (7). By containing the polyphenylene ether compound, the insulating property, the plating adhesion, and the hygroscopic heat resistance can be improved. The polyphenylene ether compound represented by the general formula (7) used in the present embodiment preferably has a number average molecular weight of 1000 or more and 7000 or less. By setting the number average molecular weight to 7,000 or less, the compatibility between the resins can be controlled. Further, by setting the number average molecular weight to 1000 or more, the original excellent insulating properties and hygroscopic heat resistance of the polyphenylene ether resin can be obtained. Among them, in order to obtain more excellent compatibility, insulation, and hygroscopic heat resistance, the number average molecular weight of the polyphenylene ether compound is preferably 1100 or more and 5000 or less. More preferably, the number average molecular weight of the polyphenylene ether compound is 4500 or less, and even more preferably, the number average molecular weight of the polyphenylene ether compound is 3000 or less. The number average molecular weight is measured using gel permeation chromatography according to a routine method.

(In the general formula (7), X represents an aryl group (aromatic group), − (YO) n ₂ − represents a polyphenylene ether moiety, and R ₁ , R ₂ and R ₃ are independent of each other. It represents a hydrogen atom, an alkyl group, an alkenyl group or an alkynyl group, n ₂ represents an integer of 1 to 100, n ₁ represents an integer of 1 to 6, and n ₃ represents an integer of 1 to 4. n ₁ is preferably an integer of 1 or more and 4 or less, more preferably n ₁ is 1 or 2, ideally n ₁ is 1 and preferably n ₃ is. It is preferably an integer of 1 or more and 3 or less, more preferably n ₃ is 1 or 2, and ideally n ₃ is 2.)

The polyphenylene ether compound represented by the general formula (7) preferably contains a polymer of the structural unit represented by the following general formula (8).

(In the general formula (8), R ₉₀₁ , R ₉₀₂ , R ₉₀₃ , and R ₉₀₄ each independently represent an alkyl group, an aryl group, a halogen atom, or a hydrogen atom having 6 or less carbon atoms.)

The polymer may further contain at least one structural unit selected from the group consisting of the structural units represented by the general formula (9) and the general formula (10).

(In the general formula (9), R ₉₀₅ , R ₉₀₆ , R ₉₀₇ , R ₉₁₁ , and R ₉₁₂ each independently represent an alkyl group or a phenyl group having 6 or less carbon atoms. R ₉₀₈ , R ₉₀₉ , and R ₉₁₀ are. Each independently represents a hydrogen atom, an alkyl group having 6 or less carbon atoms, or a phenyl group.)

(In the general formula (10), R ₉₁₃ , R ₉₁₄ , R ₉₁₅ , R ₉₁₆ , R ₉₁₇ , R ₉₁₈ , R ₉₁₉ , and R ₉₂₀ each independently contain a hydrogen atom and an alkyl group or a phenyl group having 6 or less carbon atoms. -A- is a linear, branched or cyclic divalent hydrocarbon group having 20 or less carbon atoms.)
In relation to the general formula (7), the general formulas (8), (9) and (10) are preferably − (YO) − of the general formula (7). -(YO)-has a repeating unit of a number of n ₂ (1-100).

As the aryl group in X of the general formula (7), an aromatic hydrocarbon group can be used. Specifically, a group (for example, a phenyl group, a biphenyl group, etc.) obtained by removing n3 hydrogen atoms from one ring structure selected from a benzene ring structure _, a biphenyl structure, an indenyl ring structure, and a naphthalene ring structure. Indenyl group and naphthyl group) can be used, and it is preferable to use a biphenyl group. Here, the aryl group includes a diphenyl ether group in which the above aryl group is bonded with an oxygen atom, a benzophenone group bonded with a carbonyl group, a 2,2-diphenylpropane group bonded with an alkylene group, and the like. But it may be. Further, the aryl group may be substituted with a general substituent such as an alkyl group (preferably an alkyl group having 1 to 6 carbon atoms, particularly a methyl group), an alkenyl group, an alkynyl group or a halogen atom. However, since the "aryl group" is substituted with a polyphenylene ether moiety via an oxygen atom, the limit on the number of general substituents depends on the number of polyphenylene ether moieties.

It is particularly preferable that the polyphenylene ether compound contains a polyphenylene ether represented by the structure of the following general formula (11).

(In the general formula (11), X is an aryl group (aromatic group), − (YO) n ₂ − indicates a polyphenylene ether moiety, and n ₂ is an integer of 1 to 100, respectively. Shows.)
-(YO) n _2- and n ₂ are synonymous with those in the general formula (7). It may contain a plurality of kinds of compounds having different _n2 .

X in the general formula (7) and the general formula (11) is preferably the general formula (12), the general formula (13), or the general formula (14), and the general formula (7) and the general formula (11). -(YO) n ₂ -is a structure in which the general formula (15) or the general formula (16) is arranged, or a structure in which the general formula (15) and the general formula (16) are randomly arranged. More preferred.

(In the general formula (13), R ₉₂₁ , R ₉₂₂ , R ₉₂₃ , and R ₉₂₄ each independently represent a hydrogen atom or a methyl group.-B- is a linear, branched, or cyclic group having 20 or less carbon atoms. It is a divalent hydrocarbon group of.)

(In the general formula (14), -B- is a linear, branched or cyclic divalent hydrocarbon group having 20 or less carbon atoms.)

The method for producing the modified polyphenylene ether having the structure represented by the general formula (11) is not particularly limited, and is, for example, a bifunctional phenylene obtained by oxidation-coupling a bifunctional phenol compound and a monofunctional phenol compound. It can be produced by converting the terminal phenolic hydroxyl group of the ether oligomer into vinylbenzyl ether.
Further, as such a modified polyphenylene ether, a commercially available product can be used, and for example, OPE-2St1200 and OPE-2St2200 manufactured by Mitsubishi Gas Chemical Company, Inc. can be preferably used.

In the present embodiment, when the polyphenylene ether compound is used for the first resin layer 12, the content thereof is not particularly limited, but is 1 part by mass or more with respect to 100 parts by mass of the resin solid content of the first resin layer 12. It is preferably present, and more preferably 3 parts by mass or more. The upper limit of the content is preferably less than 20 parts by mass. Within such a range, the interlayer adhesion, the plating adhesion, and the hygroscopic heat resistance can be effectively improved. The first resin layer 12 may contain only one type of polyphenylene ether compound, or may contain two or more types of polyphenylene ether compound. When two or more kinds are contained, it is preferable that the total amount is within the above range.

-Benzoxazine compound-
The benzoxazine compound is not particularly limited as long as it is a compound having two or more dihydrobenzoxazine rings in one molecule, and generally known compounds can be used. Specific examples of the benzoxazine compound include, for example, bisphenol A type benzoxazine BA-BXZ (trade name manufactured by Konishi Chemical Co., Ltd.), bisphenol F type benzoxazine BF-BXZ (trade name manufactured by Konishi Chemical Co., Ltd.), and bisphenol S type benzoxazine BS-BXZ. (Product name manufactured by Konishi Chemical Co., Ltd.) and the like. These benzoxazine compounds may be used alone or in admixture of two or more.

-Organic group modified silicone compound-
The organic group-modified silicone compound is not particularly limited, and specific examples thereof include di (methylamino) polydimethylsiloxane, di (ethylamino) polydimethylsiloxane, di (propylamino) polydimethylsiloxane, and di (epoxypropyl). Examples thereof include polydimethylsiloxane and di (epoxybutyl) polydimethylsiloxane. These organic-modified silicone compounds may be used alone or in admixture of two or more.

-Compounds with polymerizable unsaturated groups-
The compound having a polymerizable unsaturated group is not particularly limited, and generally known compounds can be used. Specific examples of the compound having a polymerizable unsaturated group include vinyl compounds such as ethylene, propylene, styrene, divinylbenzene and divinylbiphenyl; methyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-. Hydroxypropyl (meth) acrylate, polypropylene glycol di (meth) acrylate, trimethylolpropane di (meth) acrylate, trimethylolpropanetri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, etc. (Meta) acrylates of monovalent or polyhydric alcohols; epoxy (meth) acrylates such as bisphenol A type epoxy (meth) acrylate and bisphenol F type epoxy (meth) acrylate; benzocyclobutene resin and the like can be mentioned. These compounds having a polymerizable unsaturated group can be used alone or in admixture of two or more.

<Inorganic filler (B1)>
The inorganic filler (B1) means the first resin layer 12, that is, the inorganic filler contained in the first resin composition. As the inorganic filler (B1), a spherical filler can be used from the viewpoint of low thermal expansion rate, moldability, filling property and rigidity, and is not particularly limited as long as it is a spherical filler used for the insulating layer of the printed wiring board. ..

Examples of the inorganic filler (B1) include magnesium hydroxide; magnesium oxide; silica such as natural silica, molten silica, amorphous silica, and hollow silica; molybdenum compounds such as molybdenum disulfide, molybdenum oxide, and zinc molybdenum; alumina; Aluminum nitride; glass; talc; titanium compounds such as titanium oxide, barium titanate, and strontium titanate; zirconium oxide and the like can be mentioned. These can be used by appropriately mixing one kind or two or more kinds.

Among them, silica is preferable as the inorganic filler (B1) from the viewpoint of low thermal expansion, and specifically, spherical molten silica is preferable. Commercially available spherical fused silica includes SC2050-MB, SC2500-SQ, SC4500-SQ, SO-C2, SO-C1, K180SQ-C1 manufactured by Admatex Co., Ltd., and M273 manufactured by CIK Nanotech Co., Ltd. Examples include SFP-130MC manufactured by Denka Co., Ltd.

The particle size of the inorganic filler (B1) is not particularly limited, but is preferably not more than or equal to the film thickness of the first resin layer 12, for example, preferably 5 μm or less, more preferably 3 μm or less, still more preferably 2 μm or less. , 1.0 μm or less is even more preferable. The particle size of the inorganic filler (B1) can be measured by a laser diffraction / scattering method based on the Mie scattering theory. As the measurement sample, an inorganic filler (B1) dispersed in water by ultrasonic waves can be preferably used. As the laser diffraction / scattering type particle size distribution measuring device, "MT3000II" manufactured by Microtrac Bell Co., Ltd. or the like can be used.

Further, the inorganic filler (B1) may be surface-treated with a silane coupling agent or the like. As the silane coupling agent, the silane coupling agent described later can be used.

[Second resin layer]
The second resin layer 13 contains a thermosetting resin (A2) and an inorganic filler (B2), and the content of the inorganic filler (B2) is 15% by volume or more and 35% by volume or less. It is composed of things. If the content of the inorganic filler (B2) is higher than this, the flexibility is reduced and cracks are more likely to occur, and conversely, if the content of the inorganic filler (B2) is lower than this, smear is removed. This is because the sex becomes low. The content of the inorganic filler (B2) is the content of the inorganic filler (B2) with respect to the second resin composition (inorganic filler (B2) / second resin composition × 100). ..

Further, the total content (total inorganic filler content) of the inorganic filler (B1) and the inorganic filler (B2) with respect to the total of the first resin composition and the second resin composition is 2. It is preferably 5% by volume or more and 33.3% by volume or less. This is because within this range, the smear removability can be improved while suppressing the occurrence of cracks.

The thickness of the second resin layer 13 is not particularly limited, but is preferably 10 μm or less from the viewpoint of thinning, and is preferably 1 μm or more in consideration of ensuring insulation. The second resin layer 13 is preferably in a semi-cured state (B-Stage). The second resin layer 13 can be formed by a known means such as coating by using, for example, the second resin composition. The second resin composition may contain other additives described later, if necessary.

<Thermosetting resin (A2)>
The thermosetting resin (A2) is not particularly limited, and is, for example, an epoxy compound, a cyanate ester compound, a maleimide compound, a phenol compound, a polyphenylene ether compound, a benzoxazine compound, an organic group-modified silicone compound, and polymerization. Examples include compounds having possible unsaturated groups. As these compounds, the same compounds as those exemplified for the thermosetting resin (A1) can be used. The thermosetting resin (A2) can be used by appropriately mixing one or more of these. Above all, it is preferable to include an epoxy compound and a phenol compound because excellent peel strength can be obtained, and it is more preferable to further contain a maleimide compound together with the epoxy compound and the phenol compound.

In the present embodiment, when the epoxy compound is used for the second resin layer 13, the content thereof is not particularly limited, but from the viewpoint of heat resistance and curability, the resin solid content of the second resin layer 13 is 100 parts by mass. On the other hand, the range of 10 to 80 parts by mass is preferable, and the range of 30 to 70 parts by mass is particularly preferable.

In the present embodiment, when the phenol compound is used for the second resin layer 13, the content thereof is not particularly limited, but from the viewpoint of heat resistance and adhesion to the copper foil, the resin solid of the second resin layer 13 is used. The range of 10 to 80 parts by mass is preferable, and the range of 20 to 60 parts by mass is more preferable with respect to 100 parts by mass.

In the present embodiment, when the maleimide compound is used for the second resin layer 13, the content thereof is not particularly limited, but from the viewpoint of heat resistance and adhesion to the copper foil, the resin solid of the second resin layer 13 is used. The range of 10 to 80 parts by mass is preferable, and the range of 10 to 50 parts by mass is more preferable with respect to 100 parts by mass.

<Inorganic filler (B2)>
The inorganic filler (B2) means the second resin layer 13, that is, the inorganic filler contained in the second resin composition. As the inorganic filler (B2), a spherical filler can be used from the viewpoint of low thermal expansion rate, moldability, filling property and rigidity, and is not particularly limited as long as it is a spherical filler used for the insulating layer of the printed wiring board. .. As the inorganic filler (B2), for example, those mentioned in the inorganic filler (B1) can be used in the same manner, and among them, silica is preferable, and specifically, spherical molten silica is preferable. The particle size and surface treatment of the inorganic filler (B2) are the same as those of the inorganic filler (B1).

[Other ingredients]
As described above, the first resin layer 12 and the second resin layer 13 in the present embodiment can each contain other components, if necessary.

As other components, for example, a silane coupling agent may be contained for the purpose of improving hygroscopic heat resistance. The silane coupling agent is not particularly limited as long as it is a silane coupling agent generally used for surface treatment of inorganic substances. Specific examples include aminosilane-based silane coupling agents (eg, γ-aminopropyltriethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane), and epoxysilane-based silane coupling agents (eg, γ-aminopropyltriethoxysilane). γ-glycidoxypropyltrimethoxysilane), acrylic silane-based silane coupling agent (eg, γ-acryloxypropyltrimethoxysilane, vinylsilane-based silane coupling agent (eg, γ-methacryloxypropyltrimethoxysilane)). , Cationic silane-based silane coupling agent (for example, N-β- (N-vinylbenzylaminoethyl) -γ-aminopropyltrimethoxysilane hydrochloride), phenylsilane-based silane coupling agent and the like. As the silane coupling agent, one kind or two or more kinds can be appropriately mixed and used.

In the present embodiment, the content of the silane coupling agent is not particularly limited, but is 0.05 with respect to 100 parts by mass of the inorganic filler (B1) or the inorganic filler (B2) from the viewpoint of improving moisture absorption and heat resistance. The range of up to 5 parts by mass is preferable, and the range of 0.1 to 3 parts by mass is more preferable. When two or more kinds of silane coupling agents are used in combination, it is preferable that the total amount of these silane coupling agents satisfies the above range.

As other components, for example, a wet dispersant may be contained for the purpose of improving manufacturability. The wet dispersant is not particularly limited as long as it is a wet dispersant generally used for paints and the like. As specific examples, Disperbyk (registered trademark) -110, -111, -118, -180, -161, BYK (registered trademark) -W996, -W9010, manufactured by Big Chemie Japan Co., Ltd. -W903 and the like can be mentioned. These wet dispersants can be used alone or in admixture of two or more.

In the present embodiment, the content of the wet dispersant is not particularly limited, but is 0.1 to 5 with respect to 100 parts by mass of the inorganic filler (B1) or the inorganic filler (B2) from the viewpoint of improving manufacturability. The range of parts by mass is preferable, and the range of 0.5 to 3 parts by mass is more preferable. When two or more kinds of wet dispersants are used in combination, it is preferable that the total amount thereof satisfies the above range.

As other components, for example, a curing accelerator may be contained for the purpose of adjusting the curing rate. The curing accelerator is not particularly limited, but is an organic metal salt containing a metal such as copper, zinc, cobalt, nickel, manganese, etc. (for example, lead naphthenate, lead stearate, zinc naphthenate, zinc octylate, tin oleate). , Dibutyltin malate, manganese naphthenate, cobalt naphthenate, nickel octylate, manganese octylate, iron acetylacetone), those obtained by dissolving these organic metal salts in hydroxyl group-containing compounds such as phenol and bisphenol, organic tin compounds (for example). , Inorganic metal salts such as tin chloride, zinc chloride, aluminum chloride; dioctyl tin oxide, other alkyl tin, alkyl tin oxide), imidazoles and derivatives thereof (eg, 2-ethyl-4-methylimidazole, 1-benzyl- 2-Phenylimidazole, 2,4,5-triphenylimidazole), tertiary amines (eg, triethylamine, N, N-dimethylbenzylamine, N, N-dimethylaniline, N, N-dimethyltoluidine, 2-N -Ethylanilinoethanol, tri-n-butylamine, pyridine, quinoline, N-methylmorpholine, triethanolamine, triethylenediamine, tetramethylbutanediamine, N-methylpiperidine, etc.), organic peroxides (eg, benzoyl peroxide) , Lauroyl peroxide, acetyl peroxide, parachlorobenzoyl peroxide, di-tert-butyl-di-perphthalate), azo compounds (eg, azobisnitrile), phenols (eg, phenol, xylenol, cresol, resorcin, Phenol). These curing accelerators can be used alone or in admixture of two or more.

In the present embodiment, the content of the curing accelerator is not particularly limited, but from the viewpoint of obtaining a high glass transition temperature, the content of the first resin layer 12 or the second resin layer 13 is 100 parts by mass with respect to the resin solid content. , 0.001 to 5 parts by mass is preferable, and the range of 0.01 to 3 parts by mass is more preferable. When two or more kinds of curing accelerators are used in combination, it is preferable that the total amount thereof satisfies the above range.

As other components, for example, various other polymer compounds and / or flame-retardant compounds may be contained. The polymer compound and the flame-retardant compound are not particularly limited as long as they are generally used.

Examples of the polymer compound include various thermosetting resins and thermoplastic resins, oligomers thereof, elastomers and the like other than the thermosetting resin (A1) or the thermosetting resin (B1). Specifically, polyimide resin, polyamide-imide resin, polystyrene, polyolefin, styrene-butadiene rubber (SBR), isoprene rubber (IR), butadiene rubber (BR), acrylonitrile butadiene rubber (NBR), polyurethane, polypropylene, (meth). Examples thereof include acrylic oligomers, (meth) acrylic polymers and silicone resins. From the viewpoint of compatibility, acrylonitrile butadiene rubber or styrene-butadiene rubber is preferable.

Specific examples of the flame-retardant compound include a phosphorus-containing compound (for example, phosphoric acid ester, phosphoric acid melamine, phosphorus-containing epoxy resin), and nitrogen-containing compound other than the inorganic filler (B1) or the inorganic filler (B2). Examples thereof include compounds (for example, melamine and benzoguanamine), oxazine ring-containing compounds, and silicone-based compounds. These polymer compounds and / or flame-retardant compounds may be used alone or in admixture of two or more.

The first resin layer 12 and the second resin layer 13 may contain various other additives for various purposes. Specific examples of additives include UV absorbers, antioxidants, photopolymerization initiators, optical brighteners, photosensitizers, dyes, pigments, thickeners, lubricants, defoaming agents, dispersants, and leveling agents. And brighteners. These additives may be used alone or in admixture of two or more.

[Manufacturing method of copper foil with resin layer]
The method for producing the copper foil 10 with a resin layer of the present embodiment is not particularly limited. As a production method, for example, first, a solution (varnish) in which the first resin composition is dissolved or dispersed in an organic solvent is applied to the surface of the copper foil 11, dried under heating and / or reduced pressure, and the solvent is used. Is removed to solidify the first resin composition to form the first resin layer 12. As described above, the first resin layer 12 may be in a completely cured state as well as in a semi-cured state. Then, a solution (varnish) in which the second resin composition is dissolved or dispersed in an organic solvent is applied onto the first resin layer 12, and dried under heating and / or reduced pressure to remove the solvent. The second resin composition is solidified to form the second resin layer 13. At this time, it is preferable that the second resin layer 13 is in a B-stage (semi-cured state). Further, a protective layer such as a plastic film may be provided on the second resin layer 13. The protective layer is appropriately removed at the time of producing the laminate described later.

The drying conditions are not particularly limited, but the first resin layer 12 or the second resin layer 13 is dried so that the amount of the organic solvent is usually 10 parts by mass or less, preferably 5 parts by mass or less, based on 100 parts by mass. Let me. The conditions for achieving drying differ depending on the amount of the organic solvent in the varnish. For example, in the case of a varnish containing 30 to 60 parts by mass of an organic solvent with respect to 100 parts by mass of the varnish, the heating conditions are 50 ° C. to 200 ° C. It may be dried underneath for about 3 to 10 minutes.

The organic solvent is not particularly limited as long as each component can be suitably dissolved or dispersed and the effect of the first resin layer 12 or the second resin layer 13 is exhibited. Specific examples of organic solvents include alcohols (eg, methanol, ethanol and propanol), ketones (eg, acetone, methylethylketone and methylisobutylketone), amides (eg, dimethylacetamide and dimethylformamide), aromatic hydrocarbons. Classes (eg, toluene and xylene), N-methyl-2-pyrrolidone, γ-butyrolactone and the like can be mentioned. These organic solvents may be used alone or in admixture of two or more.

The method of coating is also not particularly limited, but for example, bar coater coating, air knife coating, gravure coating, reverse gravure coating, micro gravure coating, micro reverse gravure coater coating, die coater coating, dip coating, spin coating coating. , A coating method known for spray coating and the like can be used.

[Laminate and its manufacturing method]
The laminate using the copper foil 10 with a resin layer of the present embodiment (hereinafter, may be simply referred to as “the laminate of the present embodiment”) is, for example, a build-up of a printed wiring board or a substrate for mounting a semiconductor element. It can be used for materials and for manufacturing coreless substrates.
The laminate of the present embodiment can be configured as a laminate having a build-up layer in which a conductor layer and an insulating layer formed by using a copper foil 10 with a resin layer are alternately laminated, for example. Here, the "insulating layer formed by using the copper foil 10 with a resin layer" means, for example, such that the second resin layer 13 of the copper foil 10 with a resin layer is in contact with the substrate on which the conductor layer is formed. Can be laminated and configured. When the insulating layer is formed by using the copper foil 10 with three or more resin layers, the copper foil 11 is removed as necessary, and the first resin layer 12 and the second resin layer 13 are laminated. Then, the insulating layer can be formed. Further, the conductor layer may be the copper foil 11 of the copper foil 10 with a resin layer, or another conductor (copper foil or the like) such as the copper foil of the copper-clad laminate may be separately laminated to form the conductor layer. May be formed. FIG. 2 shows an example of the laminated body 20 of the present embodiment. The laminated body 20 is formed by laminating a copper foil 10 with a resin layer on a substrate 22 on which a conductor layer 21 is formed so that a second resin layer 13 is in contact with the first resin layer 12. And the second resin layer 13 form an insulating layer 23.

When the laminate of the present embodiment has a build-up layer, for example, the build-up layer has a plurality of conductor layers and an insulating layer, and the conductor layer is between the insulating layers and of the build-up layer. It can be configured to be arranged on the surface of the outermost layer. At this time, the number of insulating layers is not particularly limited, but may be, for example, 3 layers or 4 layers.
Further, a coreless substrate can be produced by using the laminated body of the present embodiment. Examples of the coreless substrate include a coreless substrate having two or more layers, and examples thereof include a three-layer coreless substrate. The configuration of the coreless substrate will be described later.

[Printed wiring board]
The laminate of this embodiment can be used as a printed wiring board. Here, as the printed wiring board, a laminate using the copper foil 10 with a resin layer of the present embodiment is used as a build-up material for a metal foil-clad laminate in which an insulating resin layer called a core base material is completely cured. Can be obtained by By using the copper foil 10 (laminated body) with a resin layer of the present embodiment, for example, it is possible to manufacture a thin printed wiring board without using a thick support substrate (carrier substrate).

On the surface of the metal foil-clad laminate, a conductor circuit is formed by a conductor layer obtained by peeling off the metal foil and / or the metal foil of a commonly used metal foil-clad laminate and then plating. The base material of the metal foil-clad laminate is not particularly limited, but is mainly a glass epoxy substrate, a metal substrate, a polyester substrate, a polyimide substrate, a BT resin substrate, and a thermosetting polyphenylene ether substrate.

In the present embodiment, the build-up refers to the first resin layer 12 and the second resin layer 13 in the copper foil 10 with a resin layer with respect to the metal foil and / or the conductor layer on the surface of the metal foil-clad laminate. It is to stack.

In the manufacture of printed wiring boards, holes such as via holes and / or through holes are machined in order to electrically connect each conductor layer as needed. Drilling is usually performed using a mechanical drill, a carbon dioxide laser, a UV laser, a YAG laser, or the like. In the insulating layer formed by using the copper foil 10 with a resin layer, it is possible to improve the smear removing property while suppressing the generation of cracks in the formation of via holes, and it is possible to suppress overhang. Therefore, a good processed shape can be obtained in the conformal laser processing and the direct laser processing.

When hole processing is performed, then roughening processing including desmear processing is performed. The roughening treatment usually consists of a swelling step, a surface roughening and smear melting step, and a neutralization step. The swelling step is performed by swelling the surface of the insulating resin layer with a swelling agent. As the swelling agent, the wettability of the surface of the insulating resin layer is improved, and the surface of the insulating resin layer can be swelled to the extent that oxidative decomposition is promoted in the next surface roughening and smear dissolution steps. If so, it is not particularly limited. Examples include an alkaline solution, a surfactant solution and the like. The surface roughening and smear dissolution steps are carried out using an oxidizing agent. Examples of the oxidizing agent include an alkaline permanganate solution and the like, and suitable specific examples thereof include an aqueous solution of potassium permanganate and an aqueous solution of sodium permanganate. Such an oxidant treatment is called wet desmear, and in addition to the wet desmear, other known roughening treatments such as plasma treatment, dry desmear by UV treatment, mechanical polishing by buffing, and sandblasting are appropriately combined. May be. The neutralization step is to neutralize the oxidizing agent used in the previous step with a reducing agent. Examples of the reducing agent include amine-based reducing agents, and suitable specific examples thereof include acidic aqueous solutions such as a hydroxylamine sulfate aqueous solution, an ethylenediamine tetraacetic acid aqueous solution, and a nitrilotriacetic acid aqueous solution.

In the present embodiment, after the via hole and / or the through hole is provided, or after the via hole and / or the through hole is desmeared, it is preferable to perform a metal plating treatment to electrically connect each conductor layer. The method of the metal plating treatment is not particularly limited, and a method of the metal plating treatment in the production of a normal multilayer printed wiring board can be appropriately used. The method of metal plating treatment and the type of chemical solution used for plating are not particularly limited, and the metal plating treatment method and chemical solution in the production of a normal multilayer printed wiring board can be appropriately used. The chemical solution used for the metal plating treatment may be a commercially available product. The metal plating treatment method is not particularly limited, and is, for example, a treatment with a degreasing liquid, a treatment with a soft etching liquid, an acid cleaning, a treatment with a predip liquid, a treatment with a catalyst liquid, a treatment with an accelerator liquid, and a chemical copper liquid. Examples thereof include treatment, pickling, and treatment of immersing in a copper sulfate solution and passing a current.

Further, when the copper foil 10 with the resin layer in the semi-cured state is used for build-up, the first resin layer 12 or the second resin layer 13 in the semi-cured state is usually heat-treated. A printed wiring board can be obtained by completely curing. In the present embodiment, another copper foil 10 with a resin layer may be further laminated on the obtained printed wiring board.

The laminating method in the build-up method is not particularly limited, but a vacuum-pressurized laminator can be preferably used. In this case, the copper foil 10 with a resin layer can be laminated via an elastic body such as rubber. The laminating conditions are not particularly limited as long as they are conditions used in laminating ordinary printed wiring boards, but for example, a temperature of 70 ° C. to 140 ° C., a contact pressure in the range of 1 kgf / cm ² to 11 kgf / cm ² , and a contact pressure of 1 kgf / cm 2 to 11 kgf / cm 2. It is carried out under an atmospheric reduced pressure of 20 hPa or less. After the laminating step, the laminated adhesive film may be smoothed by hot pressing with a metal plate. The laminating step and the smoothing step can be continuously performed by a commercially available vacuum pressurizing laminator. There may be a thermosetting step after the laminating step or after the smoothing step. By using the thermosetting step, the first resin layer 12 and the second resin layer 13 can be completely cured. The thermosetting conditions differ depending on the types of components contained in the first resin layer 12 and the second resin layer 13, but usually the curing temperature is 100 ° C to 300 ° C and the pressure is 0.1 kgf / cm ² to 100 kgf. / Cm ² (about 9.8 kPa to about 9.8 MPa), curing time is 30 seconds to 5 hours.

Examples of the method for forming a circuit pattern on the copper foil on one side or both sides of the printed wiring board in the present embodiment include a semi-additive method, a full additive method, and a subtractive method. Above all, the semi-additive method is preferable from the viewpoint of forming a fine wiring pattern.

As an example of the method of forming a circuit pattern by the semi-additive method, a method of selectively electroplating using a plating resist (pattern plating), then peeling off the plating resist, and etching an appropriate amount of the whole to form a wiring pattern. Can be mentioned. In the circuit pattern formation by the semi-additive method, electroless plating and electrolytic plating are combined, and at that time, it is preferable to perform drying after electroless plating and after electrolytic plating, respectively. Drying after electroless plating is not particularly limited, but is preferably performed at 80 ° C. to 180 ° C. for 10 minutes to 120 minutes, and drying after electrolytic plating is not particularly limited, but is, for example, at 130 ° C. to 220 ° C. It is preferably performed for 10 to 120 minutes. Copper plating is preferable as the plating.

An example of a method of forming a circuit pattern by the subtractive method is a method of forming a wiring pattern by selectively removing a conductor layer using an etching resist. Specifically, for example, it can be performed as follows. A dry film resist (Hitachi Kasei RD-1225 (trade name)) is laminated and bonded (laminated) on the entire surface of the copper foil at a temperature of 110 ± 10 ° C. and a pressure of 0.50 ± 0.02 MPa. Then, exposure is performed according to the circuit pattern and masking is performed. Then, the dry film resist is developed with a 1% aqueous sodium carbonate solution, and finally the dry film resist is peeled off with an amine-based resist stripping solution. This makes it possible to form circuit patterning on the copper foil.

In the present embodiment, a multilayer printed wiring board can be obtained by further laminating an insulating resin layer and / or a conductor layer on the printed wiring board. A circuit board may be provided in the inner layer of the multilayer printed wiring board. The copper foil 10 with a resin layer constitutes one of the insulating resin layer and the conductor layer of the multilayer printed wiring board.

The laminating method is not particularly limited, and a method generally used for laminating and forming a normal printed wiring board can be used. Examples of the laminating method include a multi-stage press, a multi-stage vacuum press, a laminator, a vacuum laminator, an autoclave forming machine, and the like. The temperature at the time of stacking is not particularly limited, but is not particularly limited, for example, 100 ° C. to 300 ° C., and the pressure is not particularly limited, for example, 0.1 kgf / cm ² to 100 kgf / cm ² (about 9.8 kPa to about 9.8 MPa). ), The heating time is not particularly limited, but is appropriately selected in the range of, for example, 30 seconds to 5 hours. Further, if necessary, for example, post-curing may be performed in a temperature range of 150 ° C. to 300 ° C. to adjust the degree of curing.

[Semiconductor device mounting substrate]
As described above, the laminate of this embodiment can be used as a substrate for mounting a semiconductor element. A substrate for mounting a semiconductor element is produced, for example, by laminating a copper foil 10 with a resin layer on a metal foil-clad laminate and masking and patterning the copper foil on the surface or one side of the obtained laminate. As the masking and patterning, known masking and patterning performed in the manufacture of the printed wiring board can be used, and the circuit pattern is preferably formed by the above-mentioned subtractive method without particular limitation. The circuit pattern may be formed on only one side of the laminate, or may be formed on both sides.

[Multilayer coreless board (multilayer printed wiring board)]
The laminate of this embodiment can be a coreless substrate as described above. An example of the coreless substrate is a multilayer coreless substrate.
The multilayer coreless substrate is, for example, a plurality of insulating layers composed of a first insulating layer, one or a plurality of second insulating layers laminated on one side of the first insulating layer, and a plurality of insulating layers. It has a plurality of conductor layers composed of a first conductor layer arranged between each and a second conductor layer arranged on the surface of the outermost layer of the plurality of insulating layers, and the first insulating layer and The second insulating layer can be configured to have a cured product of the first resin layer 12 and the second resin layer 13 of the copper foil 10 with a resin layer, respectively. A specific example of the multilayer coreless substrate will be described with reference to FIG. FIG. 3 is a schematic diagram showing an example of a multilayer coreless substrate in this embodiment. The multilayer coreless substrate 100 shown in FIG. 3 includes a first insulating layer 111 and two second insulating layers 112 laminated in one side direction (upper surface direction in the drawing) of the first insulating layer 111. The insulating layer 111 and the two second insulating layers 112 are formed by using the first resin layer 12 and the second resin layer 13 of the copper foil 10 with one resin layer, respectively. Further, in the multilayer coreless substrate 100 shown in FIG. 3, the first conductor layer 113 arranged between each of the plurality of insulating layers (first insulating layer 111 and the second insulating layer 112) and their respective insulating layers 113. It has a plurality of conductor layers composed of a second conductor layer 114 arranged on the outermost layer of the plurality of insulating layers (first insulating layer 111 and second insulating layer 112).

As described above, according to the present embodiment, in the formation of the via hole, it is possible to improve the smear removal property while suppressing the generation of cracks, and it is possible to suppress the overhang. Therefore, it is possible to obtain a good processing shape in both the conformal laser processing and the direct laser processing.

The present invention will be described in more detail below with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.

(Example 1)
Terminal styrenated polyphenylene ether compound (product name: OPE-2St2200, manufactured by Mitsubishi Gas Chemical Company, Inc.) 15.0 parts by mass, polyimide resin (product name: Neoprim (registered trademark) S100, manufactured by Mitsubishi Gas Chemical Company, Inc.) 49 .9 parts by mass, 2,2-bis- (4- (4-maleimidephenoxy) phenylpropane (product name: BMI-80, manufactured by KI Kasei Co., Ltd.) 34.9 parts by mass, 2,4,5 -The first resin composition was obtained by blending (mixing) 0.2 parts by mass of triphenylimidazole (manufactured by Tokyo Chemical Industry Co., Ltd.). That is, the inorganic filler was added to the first resin composition. Next, the first resin composition was diluted with N-methyl-2-pyrrolidone (hereinafter referred to as “NMP”) to obtain varnish A. The obtained varnish A was 3 μm thick by a bar coater. The copper foil 11 (product name: MT-FL, manufactured by Mitsui Metal Mining Co., Ltd.) was applied to the matte surface side. Then, the coating film was heated and dried at 180 ° C. for 10 minutes onto the copper foil 11. The first resin layer 12 was formed.

In addition, biphenyl aralkyl type phenol resin (product name: KAYAHARD GPH-103, hydroxyl group equivalent: 231 g / eq., manufactured by Nippon Kayaku Co., Ltd.) 35.8 parts by mass, bis (3-ethyl-5-methyl-4- Maleimide diphenyl) methane (product name: BMI-70, manufactured by Keiai Kasei Co., Ltd.) 17.9 parts by mass, naphthalene aralkyl type epoxy resin (product name: HP-9900, epoxy equivalent: 274 g / eq., DIC ( (Co., Ltd.) 7.0 parts by mass, biphenyl aralkyl type epoxy resin (product name: NC-3000-FH, manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent: 320 g / eq.) 38.8 parts by mass, 2,4 , 5-Triphenylimidazole (manufactured by Tokyo Kasei Kogyo Co., Ltd.) 0.5 parts by mass, silica (product name: M273, average particle size 0.1 μm, manufactured by CIK Nanotech Co., Ltd.) as an inorganic filler (B2). The second resin composition was obtained by blending (mixing). At that time, the content of silica as the inorganic filler (B2) with respect to the second resin composition (inorganic filler (B2) / second resin composition × 100) was set to 15% by volume. Then, this second resin composition was diluted with methyl ethyl ketone to obtain varnish B. The obtained varnish B was applied by a bar coater onto the first resin layer 12 obtained by the above method. Then, the coating film was heated and dried at 150 ° C. for 10 minutes to obtain a copper foil 10 with a resin layer having a first resin layer 12 and a second resin layer 13.

The thickness of the first resin layer 12 was 5 μm, and the thickness of the second resin layer 13 was 1 μm. Further, the total content (total inorganic filler content) of the inorganic filler (B1) and the inorganic filler (B2) with respect to the total of the first resin composition and the second resin composition is 2. 5% by volume.

(Example 2)
Silica (product name: K180SQ-C1, average particle size 0.18 μm, manufactured by Admatex Co., Ltd.) is blended (mixed) as an inorganic filler (B1) in the first resin composition, and the first resin layer 12 is mixed. The first resin layer 12 was formed on the copper foil 11 in the same manner as in Example 1 except that the thickness of the resin was 2.5 μm. At that time, the content of silica as the inorganic filler (B1) with respect to the first resin composition (inorganic filler (B1) / first resin composition × 100) was set to 14% by volume.

The same as in Example 1 except that the content of silica as the inorganic filler (B2) in the second resin composition was 20% by volume and the thickness of the second resin layer 13 was 5 μm. The second resin layer 13 was formed on the first resin layer 12. The total content (total inorganic filler content) of the inorganic filler (B1) and the inorganic filler (B2) with respect to the total of the first resin composition and the second resin composition is 18.0 volumes. %.

(Example 3)
The first resin layer 12 was formed on the copper foil 11 in the same manner as in Example 1 except that the thickness of the first resin layer 12 was 2.5 μm. That is, no inorganic filler was added to the first resin composition. The same as in Example 1 except that the content of silica as the inorganic filler (B2) in the second resin composition was 20% by volume and the thickness of the second resin layer 13 was 5 μm. The second resin layer 13 was formed on the first resin layer 12. The total content (total inorganic filler content) of the inorganic filler (B1) and the inorganic filler (B2) with respect to the total of the first resin composition and the second resin composition is 13.3 volumes. %.

(Example 4)
Silica (product name: K180SQ-C1, average particle size 0.18 μm, manufactured by Admatex Co., Ltd.) is blended (mixed) as an inorganic filler (B1) in the first resin composition, and the first resin layer 12 is mixed. The first resin layer 12 was formed on the copper foil 11 in the same manner as in Example 1 except that the thickness of the resin was 1 μm. At that time, the content of silica as the inorganic filler (B1) with respect to the first resin composition (inorganic filler (B1) / first resin composition × 100) was set to 14% by volume.

The same as in Example 1 except that the content of silica as the inorganic filler (B2) in the second resin composition was 35% by volume and the thickness of the second resin layer 13 was 10 μm. The second resin layer 13 was formed on the first resin layer 12. The total content (total inorganic filler content) of the inorganic filler (B1) and the inorganic filler (B2) with respect to the total of the first resin composition and the second resin composition is 33.3 volumes. %.

(Example 5)
Silica (product name: K180SQ-C1, average particle size 0.18 μm, manufactured by Admatex Co., Ltd.) is blended (mixed) as an inorganic filler (B1) in the first resin composition, and the first resin layer 12 is mixed. The first resin layer 12 was formed on the copper foil 11 in the same manner as in Example 1 except that the thickness of the resin was 2.5 μm. At that time, the content of silica as the inorganic filler (B1) with respect to the first resin composition (inorganic filler (B1) / first resin composition × 100) was set to 1.1% by volume.

The same as in Example 1 except that the content of silica as the inorganic filler (B2) in the second resin composition was 25% by volume and the thickness of the second resin layer 13 was 5 μm. The second resin layer 13 was formed on the first resin layer 12. The total content (total inorganic filler content) of the inorganic filler (B1) and the inorganic filler (B2) with respect to the total of the first resin composition and the second resin composition is 22.7 volumes. %.

(Comparative Example 1)
The first resin layer 12 was formed on the copper foil 11 in the same manner as in Example 1 except that the thickness of the first resin layer 12 was 2.5 μm. That is, no inorganic filler was added to the first resin composition. Further, except that the inorganic filler was not added to the second resin composition and the thickness of the second resin layer 13 was set to 5 μm, the other steps were the same as in Example 1 of the first resin layer 12. A second resin layer 13 was formed on the top. The total content (total inorganic filler content) of the inorganic filler (B1) and the inorganic filler (B2) with respect to the total of the first resin composition and the second resin composition is 0.0 volume. %.

(Comparative Example 2)
Silica (product name: K180SQ-C1, average particle size 0.18 μm, manufactured by Admatex Co., Ltd.) is blended (mixed) as an inorganic filler (B1) in the first resin composition, and the first resin layer 12 is mixed. The first resin layer 12 was formed on the copper foil 11 in the same manner as in Example 1 except that the thickness of the resin was 2.5 μm. At that time, the content of silica as the inorganic filler (B1) with respect to the first resin composition (inorganic filler (B1) / first resin composition × 100) was set to 15% by volume.

Further, except that the inorganic filler was not added to the second resin composition and the thickness of the second resin layer 13 was set to 5 μm, the other steps were the same as in Example 1 of the first resin layer 12. A second resin layer 13 was formed on the top. The total content (total inorganic filler content) of the inorganic filler (B1) and the inorganic filler (B2) with respect to the total of the first resin composition and the second resin composition is 5.0 volumes. %.

(Comparative Example 3)
The first resin layer 12 was formed on the copper foil 11 in the same manner as in Example 1 except that the thickness of the first resin layer 12 was 2.5 μm. That is, no inorganic filler was added to the first resin composition. The same as in Example 1 except that the content of silica as the inorganic filler (B2) in the second resin composition was 40% by volume and the thickness of the second resin layer 13 was 5 μm. The second resin layer 13 was formed on the first resin layer 12. The total content (total inorganic filler content) of the inorganic filler (B1) and the inorganic filler (B2) with respect to the total of the first resin composition and the second resin composition is 26.7 volumes. %.

(Comparative Example 4)
Silica (product name: K180SQ-C1, average particle size 0.18 μm, manufactured by Admatex Co., Ltd.) is blended (mixed) as an inorganic filler (B1) in the first resin composition, and the first resin layer 12 is mixed. The first resin layer 12 was formed on the copper foil 11 in the same manner as in Example 1 except that the thickness of the resin was 2.5 μm. At that time, the content of silica as the inorganic filler (B1) with respect to the first resin composition (inorganic filler (B1) / first resin composition × 100) was set to 25% by volume.

The same as in Example 1 except that the content of silica as the inorganic filler (B2) in the second resin composition was 14% by volume and the thickness of the second resin layer 13 was 5 μm. The second resin layer 13 was formed on the first resin layer 12. The total content (total inorganic filler content) of the inorganic filler (B1) and the inorganic filler (B2) with respect to the total of the first resin composition and the second resin composition is 17.7 volumes. %.

(Characteristic evaluation)
The characteristics of each Example and each Comparative Example were measured by the following methods.

(Evaluation of conformal laser workability)
Etching both sides of a copper foil-clad laminate (HL832NS (trade name) T / T 0.2 mmt, manufactured by Mitsubishi Gas Chemical Company, Inc.) on which an inner layer circuit is formed by about 0.5 μm to 1 μm (inner layer roughening treatment, CZ-8101) (Product name), manufactured by MEC Co., Ltd.), and the copper foil 10 with a resin layer obtained in each Example and each Comparative Example was arranged on both sides thereof so that the second resin layer 13 was on the inside. Laminate molding (heat curing) was performed at a pressure of 30 kgf / cm ² and a temperature of 220 ° C. for 90 minutes to obtain a four-layer substrate.

A circular opening with a diameter of about 15 μm was formed in the copper foil on the surface of each of the obtained four-layer substrates by a subtractive method, and a non-through hole with a diameter of about 15 μm was formed by irradiating the same with a laser. Next, as a smear removing step, each of the four-layer substrates obtained on the plating jig was racked, and the immersion was shaken in the expansion tank, the etching tank, and the neutralization tank. The chemical solution used was an up-death process manufactured by C. Uyemura & Co., Ltd. The swelling solution was Updes MDS-37, the etching solution was a mixture of Updes MDE-40 and ELC-SH, and the neutralization was Updes MDN-62. The temperature of the etching tank was 80 ° C., and the etching tank was immersed for 10 minutes.

Subsequently, each of the four-layer substrates obtained in the plating jig was racked, and electroless copper plating was performed with an device of Armex PE Co., Ltd., which can be immersed and rocked in an electroless copper plating tank. The chemical solution used was a mixture of Sulcup PEA manufactured by C. Uyemura & Co., Ltd. and formaldehyde. The electroless copper plating thickness was 0.4 μm. Next, as the via filling plating, an immersion type device of Almex PE Co., Ltd. was used, and plating was performed so as to have a thickness of 15 μm.

In order to confirm the hole diameter of the non-through hole in each of the plated 4-layer boards, first, the cross-section of the non-through hole was formed by a cross-section polishing machine of Marumoto Struas Co., Ltd. For polishing, rough cutting was performed using # 1000 polishing paper, a cross section at the center of the non-through hole was cut out with # 2400 polishing paper, and buffing was performed as a finish. The observation after cutting out the cross section was performed using a metallurgical microscope Olympus Co., Ltd. GX51 with a magnification of 50 times or 100 times. The top diameter and bottom diameter were measured for each of the prepared samples, and the top-bottom ratio (bottom diameter / top diameter) was calculated. The results obtained are shown in Table 1. In Table 1, when the bottom diameter / top diameter was 0.7 or more and 1 or less, it was evaluated as “◯”, and when it was less than 0.7 and other cases, it was evaluated as “x”. When the bottom diameter / top diameter is "x", the smear removal property is poor and the bottom diameter becomes small due to the remaining smear, and the opening diameter and the first resin layer 12 and the second resin are used. It is conceivable that the balance of the volume fraction of the inorganic filler in the layer 13 is poor and the processed shape is not good.

(Evaluation of direct laser workability)
Similar to the evaluation of conformal laser workability, the copper foil 10 with a resin layer obtained in each Example and each Comparative Example was laminated on both sides of a copper foil-clad laminate to obtain a four-layer substrate. The surface copper foil was blackened on each of the obtained four-layer substrates, and a through hole having a diameter of about 40 μm was formed therein by irradiating the surface copper foil with a laser. Next, smear removal, electroless copper plating, and via filling plating were performed in the same manner as in the evaluation of conformal laser processability. In addition, for each of the plated 4-layer substrates, the cross-section of the through holes was made, the top diameter and bottom diameter were measured, and the top-bottom ratio (bottom diameter / top diameter) was determined in the same manner as in the evaluation of conformal laser workability. Calculated. The results obtained are shown in Table 1. The criteria for the evaluation of "○" and "×" are the same as the evaluation of conformal laser workability.

(Evaluation of laminated film strength)
The resin composition of the copper foil 10 with a resin layer obtained in each Example and each comparative example was repeatedly pressed by laminating press (at 220 ° C. for 90 minutes), and then the copper foil on the surface layer was etched and laminated. A resin sheet having a layer thickness of 30 μm was prepared, and a part thereof was cut out to obtain a test piece. This test piece was placed on a slide glass, and a load was applied to 10 places with a micro Vickers hardness tester (trade name: HMV-G, manufactured by Shimadzu Corporation, load 2 kgf, holding time 15 seconds). As a result, when a cross-shaped crack occurred, the length and width of the crack were measured respectively. When no crack was found, the length of the crack was set to 0. Calculate the average value of the crack length from both the vertical and horizontal lengths of the crack, and if the average value is 400 μm or less, it is “◎”, if it is 401 μm or more and 1000 μm or less, it is “〇”, otherwise. In the case of, it was set as "x". The results obtained are shown in Table 1.

As shown in Table 1, according to Examples 1 to 5, good results were obtained in all of the conformal laser processability, the direct laser process, and the laminated film strength. On the other hand, in Comparative Examples 1 and 2 in which the content of the inorganic filler (B2) in the second resin composition is less than 15% by volume, smear residue is generated, and conformal laser processability and direct laser processing are performed. No good results were obtained. In Comparative Example 3 in which the content of the inorganic filler (B2) in the second resin composition was more than 35% by volume, the crack length was long and good results could not be obtained. Further, in Comparative Example 4 in which the content of the inorganic filler (B1) in the first resin composition is more than 15% by volume, overhang occurs in the direct laser machining, and both the conformal laser workability and the direct laser machining are top. Good results were not obtained in the bottom ratio.

That is, no inorganic filler is added to the first resin composition, or the inorganic filler (B1) is added to reduce the content of the inorganic filler (B1) to 15% by volume or less and the second. If the inorganic filler (B2) is added to the resin composition so that the content of the inorganic filler (B2) is 15% by volume or more and 35% by volume or less, cracks are suppressed and the conformal laser processing is performed. However, it was found that a good processed shape can be obtained even in direct laser processing.

10 ... Copper foil with resin layer, 11 ... Copper foil, 12 ... First resin layer, 13 ... Second resin layer, 20 ... Laminate, 21 ... Conductor layer, 22 ... Substrate, 23 ... Insulation layer, 100 ... Multilayer coreless substrate, 111 ... first insulating layer, 112 ... second insulating layer, 113 ... first conductor layer, 114 ... second conductor layer

Claims

A copper foil with a resin layer having a copper foil, a first resin layer laminated on the copper foil, and a second resin layer laminated on the first resin layer.
The first resin layer is a first resin composition containing a thermosetting resin (A1) and not containing an inorganic filler, or a thermosetting resin (A1) and an inorganic filler (B1). The second resin layer comprises a first resin composition containing 15% by volume or less of the inorganic filler (B1), and the second resin layer contains a thermosetting resin (A2) and an inorganic filler (B2). A copper foil with a resin layer, comprising a second resin composition containing the inorganic filler (B2) having a content of 15% by volume or more and 35% by volume or less.
The total content of the inorganic filler (B1) and the inorganic filler (B2) with respect to the total of the first resin composition and the second resin composition is 2.5% by volume or more 33. The copper foil with a resin layer according to claim 1, which is 3% by volume or less.
The copper foil with a resin layer according to claim 1, wherein the thickness of the first resin layer is 1 μm or more and 5 μm or less.
The copper foil with a resin layer according to claim 1, wherein the thickness of the second resin layer is 1 μm or more and 10 μm or less.
The thermosetting resin (A1) includes a polyimide resin, a liquid crystal polyester, an epoxy compound, a cyanate ester compound, a maleimide compound, a phenol compound, a polyphenylene ether compound, a benzoxazine compound, an organic group-modified silicone compound, and a non-polymerizable resin. The copper foil with a resin layer according to claim 1, which contains at least one selected from the group consisting of compounds having a saturated group.
The thermosetting resin (A2) is composed of an epoxy compound, a cyanate ester compound, a maleimide compound, a phenol compound, a polyphenylene ether compound, a benzoxazine compound, an organic group-modified silicone compound, and a compound having a polymerizable unsaturated group. The copper foil with a resin layer according to claim 1, which contains at least one selected from the group.
The inorganic filler (B1) and the inorganic filler (B2) are at least one selected from magnesium hydroxide, magnesium oxide, silica, molybdenum compound, alumina, aluminum nitride, glass, talc, titanium compound, and zirconium oxide. The copper foil with a resin layer according to claim 1, which is contained.
A laminate having a conductor layer and a build-up layer formed by using the copper foil with the resin layer according to claim 1.