CN116075557A - Copper foil with resin layer and laminate using the same - Google Patents

Abstract

The invention provides a copper foil with a resin layer, which can improve the removal of adhesive residues (smear) and inhibit overhanging (overhang), and a laminate using the same. The resin layer-attached copper foil 10 of the present invention comprises: the copper foil 11, the first resin layer 12 laminated on the copper foil 11, and the second resin layer 13 laminated on the first resin layer 12. The first resin layer 12 is composed of a first resin composition containing a thermosetting resin (A1) and no inorganic filler, or is composed of a first resin composition containing a thermosetting resin (A1) and an inorganic filler (B1), and the content of the inorganic filler (B1) is 15% by volume or less. The second resin layer 13 is composed of a second resin composition containing 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.

Description

Copper foil with resin layer and laminate using the same

[ field of technology ]

The present invention relates to a copper foil with a resin layer and a laminate using the same. More specifically, the present invention relates to a resin layer-attached copper foil useful for printed circuit boards or substrates for mounting semiconductor devices, and a laminate using the same.

[ background Art ]

In recent years, printed circuit boards and semiconductor device mounting boards widely used in electronic devices, communication devices, personal computers, and the like have been increasingly developed toward higher density, higher integration, and lighter weight. Accordingly, a build-up method of alternately stacking a conductor layer on which a circuit is formed and an insulating layer (interlayer insulating layer) is widely used in a method of manufacturing a printed circuit board or a substrate for mounting a semiconductor device; the circuit pattern is formed by a half-additive method capable of forming a fine pattern.

As an insulating layer for a printed wiring board, an insulating layer obtained by laminating a resin composition layer is known (for example, refer to patent document 1). Patent document 1 further solves the problem of distortion of the shape of a via hole by generating a step in the via hole of each layer at the time of laser processing by adjusting the etching amount of each layer that has been laminated. As such, through holes have been continuously developed in the past to obtain a good processing shape.

[ Prior Art literature ]

[ patent literature ]

Patent document 1 Japanese patent application laid-open No. 2017-50561

[ invention ]

[ problem to be solved by the invention ]

However, for example, the characteristics required in the case of forming a via by conformal laser processing are not the same as those in the case of forming a via by direct laser processing, and development of a material that can obtain a good processing shape in both processing methods is continuously pursued. For example, in the case of conformal laser processing, it is required that the removal of the desmear (smooth) is high, and in the case of direct laser processing, it is required that overhang (overhang) or the like is suppressed. Patent document 1 does not solve these problems, and its specific constitution is also different from the present invention.

The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a resin layer-attached copper foil which can improve the removal of the mold residue and can suppress overhang, and a laminate using the same.

[ means of technology ]

The inventors found that: the present invention has been made in view of the above problems, and an object of the present invention is to provide a copper foil with a resin layer, which has a copper foil, a first resin layer laminated on the copper foil, and a second resin layer laminated on the first resin layer, wherein the ratio of inorganic filler in the first resin layer and the second resin layer is adjusted.

That is, the present invention is as follows.

[1] A resin layer-attached copper foil comprising: a copper foil, a first resin layer laminated on the copper foil, and a second resin layer laminated on the first resin layer; it is characterized in that

The first resin layer is composed of a first resin composition containing a thermosetting resin (A1) and no inorganic filler, or is composed of a first resin composition containing a thermosetting resin (A1) and an inorganic filler (B1), and the content of the inorganic filler (B1) is 15% by volume or less;

the second resin layer is composed of a second resin composition containing a thermosetting resin (A2) and an inorganic filler (B2), and the content of the inorganic filler (B2) is 15 to 35% by volume.

[2] The resin layer-attached copper foil according to [1], wherein the total content of the inorganic filler (B1) and the inorganic filler (B2) is 2.5% by volume or more and 33.3% by volume or less relative to the total of the first resin composition and the second resin composition.

[3] The resin layer-attached copper foil according to [1], wherein the thickness of the first resin layer is 1 μm to 5 μm.

[4] The resin layer-attached copper foil according to [1], wherein the thickness of the second resin layer is 1 μm or more and 10 μm or less.

[5] The resin layer-attached copper foil according to [1], wherein the thermosetting resin (A1) contains at least one selected from the group consisting of polyimide resins, liquid crystal polyesters, epoxy compounds, cyanate ester compounds, maleimide compounds, phenol compounds, polyphenylene ether compounds, benzoxazine compounds, organic group-modified silicone compounds, and compounds having polymerizable unsaturated groups.

[6] The resin layer-attached copper foil according to [1], wherein the thermosetting resin (A2) contains at least one selected from the group consisting 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.

[7] The resin layer-attached copper foil according to [1], wherein the inorganic filler (B1) and the inorganic filler (B2) contain at least one selected from the group consisting of magnesium hydroxide, magnesium oxide, silica, molybdenum compounds, aluminum oxide, aluminum nitride, glass, talc, titanium compounds, and zirconium oxide.

[8] A laminate comprising a conductor layer and a build-up layer formed by using the resin layer-attached copper foil according to [1 ].

[ Effect of the invention ]

According to the present invention, when forming the through hole, occurrence of cracks can be suppressed, and at the same time, the removal property of the cement slag can be improved, and overhang can be suppressed. Therefore, a good processing shape can be obtained in both conformal laser processing and direct laser processing.

[ description of the drawings ]

Fig. 1 is a schematic view showing the structure of a resin layer-attached copper foil according to an embodiment of the present invention.

Fig. 2 is a schematic diagram showing an example of a laminate according to an embodiment of the present invention.

Fig. 3 is a schematic diagram showing an example of a multilayer coreless substrate according to an embodiment of the present invention.

[ detailed description ] of the invention

The mode 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 may be made without departing from the gist of the present invention. In the present description, the layers of the laminate are adhered to each other, but the layers may be peeled off from each other as required.

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

[ copper foil with resin layer ]

Fig. 1 is a diagram showing a structure of a resin layer-attached copper foil 10 according to an embodiment of the present invention. The resin layer-attached copper foil 10 includes: the copper foil 11, the first resin layer 12 laminated on the copper foil 11, and the second resin layer 13 laminated on the first resin layer 12.

The resin layer-attached copper foil 10 is useful, for example, as a material for forming an insulating layer provided on a circuit pattern (conductor layer), and is useful, for example, as a material for forming an insulating layer for a printed circuit board or a substrate for mounting a semiconductor device in the manufacture of electronic devices, communication devices, personal computers, and the like. For example, in the case of manufacturing a printed circuit board or the like, the copper foil 10 with the resin layer is disposed on a substrate on which a conductor layer such as a circuit pattern is formed so that the second resin layer 13 is in contact with the conductor layer, and then the first resin layer 12 and the second resin layer 13 are cured by heating and pressing (pressing), thereby forming an insulating layer on the conductor layer.

The second resin layer 13 is a layer containing a resin having fluidity during the press treatment, and is a layer in which the concave-convex portions such as the conductor layer of the circuit pattern are embedded. The first resin layer 12 is a layer which maintains the distance between the copper foil 11 and the second resin layer 13 even after the isostatic pressing process in the formation of the laminate in order to maintain the insulation between the copper foil 11 and the conductor layer embedded in the second resin layer 13. Since the second resin layer 13 functions as a buried layer, it is desirable that at least one of the constituent components and physical properties thereof is different from the first resin layer 12. For example, the first resin layer 12 and the second resin layer 13 are different from each other, but not particularly limited thereto: the first resin layer 12 is made of polyimide resin, the second resin layer 13 is made of epoxy compound, etc., and the components are different depending on the kind of resin; the physical properties may be different depending on the mixing ratio of the components contained in the respective layers or the cured state (for example, the first resin layer 12 is completely cured and the second resin layer 13 is semi-cured by changing the coating conditions of the respective layers); and, such complex situations, etc.

[ copper foil ]

The copper foil 11 may be any copper foil as long as it is used for a general printed circuit board, and examples thereof include: electrolytic copper foil, rolled copper foil, and copper alloy film. The copper foil 11 may be provided with, for example: surface treatments such as matting, corona treatment, nickel treatment and cobalt treatment are known. The copper foil 11 of the present embodiment can be commercially available, and examples thereof include: "GHY" (trade name, 12 μm thick copper foil) and "JXUT-I" (trade name, 1.5 μm thick copper foil) manufactured by JX Metal Co., ltd; "MT-FL" (trade name, 3 μm thick copper foil), "3EC-VLP" (trade name, 12 μm thick copper foil), "3EC-III" (trade name, 12 μm thick copper foil), "3EC-M2S-VLP" (trade name, 12 μm thick copper foil) manufactured by Mitsui Metal mining Co., ltd.; and copper foil "GTS-MP" (trade name, 12 μm thick copper foil) manufactured by Gu He electric industries Co., ltd.

The arithmetic average roughness (Ra) of the copper foil surface is usually preferably 0.05 μm to 2 μm, more preferably 0.08 μm to 1.7 μm, from the viewpoint of improving the adhesion strength between the copper foil 11 and the first resin layer 12 and preventing peeling from occurring over a long period of time, and particularly preferably 0.2 μm to 1.6 μm from the viewpoint of obtaining more excellent adhesion. The arithmetic average roughness may be measured using a commercially available shape measuring microscope (a laser microscope, for example, "VK-1000" (trade name) manufactured by Kidney Co., ltd.).

The thickness of the copper foil 11 is not particularly limited, but is preferably in the range of 1 μm to 18 μm in view of the roughening treatment of the surface, and is more preferably in the range of 2 μm to 15 μm in order to obtain a thin printed circuit board and a substrate for mounting a semiconductor device appropriately.

[ first resin layer ]

The first resin layer 12 is composed of a first resin composition containing a thermosetting resin (A1) and no inorganic filler, or is composed of a first resin composition containing a thermosetting resin (A1) and an inorganic filler (B1), and the content of the inorganic filler (B1) is 15% by volume or less. That is, the first resin layer 12 does not contain an inorganic filler, or even if it contains an inorganic filler, the content thereof is 15% by volume or less. The reason is that: when the inorganic filler is added, the workability is improved, but if the content exceeds 15% by volume, it becomes difficult to obtain a good working shape due to the relation with the second resin layer 13. The first resin composition does not contain an inorganic filler, or even if it contains an inorganic filler, the content thereof is more preferably less than 5% by volume. By blending the above, the adhesion of the copper foil and the circuit formation can be improved. In addition, in hole processing by direct laser, occurrence of overhang can be suppressed. The content of the inorganic filler (B1) refers to the content of the inorganic filler (B1) relative 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 from the viewpoint of ensuring insulation properties. The first resin layer 12 may be in a half-cured state (B-Stage) or in a fully cured state (C-Stage). The first resin layer 12 can be formed by a known method such as coating using a first resin composition. The first resin composition may optionally contain other additives which will be described later.

< thermosetting resin (A1) >)

The thermosetting resin (A1) is not particularly limited, and examples thereof include: polyimide resins, liquid crystalline polyesters, epoxy compounds, cyanate ester compounds, maleimide compounds, phenol compounds, polyphenylene ether compounds, benzoxazine compounds, organic group-modified silicone compounds, and compounds having polymerizable unsaturated groups. One of these may be used, or two or more of these may be suitably mixed for use. Among them, it is preferable to contain at least one of a polyimide resin and a liquid crystal polyester, since the thickness reduction ratio can be reduced. In addition, if an epoxy compound and a phenol compound are contained in addition to the polyimide resin or the liquid crystal polyester, excellent peel strength and adhesion to the second resin layer 13 can be obtained, and therefore, it is preferable; in addition, it is more preferable to further contain a maleimide compound.

Polyimide resin-

The polyimide resin may be used by appropriately selecting a commercially available product, and for example, a solvent-soluble polyimide resin synthesized by the production method described in JP-A2005-15629 may be used. Specifically, the solvent-soluble polyimide resin is obtained by condensing one or more selected from the group consisting of an aliphatic tetracarboxylic dianhydride represented by the following formula (1), an aliphatic tetracarboxylic acid represented by the following formula (2), and a derivative of the aliphatic tetracarboxylic acid with one or more diamine compounds in the presence of a tertiary amine compound in a solvent.

[ chemical 1]

(wherein R is a tetravalent aliphatic hydrocarbon group having 4 to 16 carbon atoms.)

[ chemical 2]

(wherein R is a tetravalent aliphatic hydrocarbon group having 4 to 16 carbon atoms, Y ₁ ～Y ₄ Is independently hydrogen or a hydrocarbon group having 1 to 8 carbon atoms. )

In the above production method, the polycondensation may be carried out by heating a slightly equimolar amount of the aliphatic tetracarboxylic acid and the diamine compound in a solvent in the presence of the tertiary amine compound. The molar ratio of the aliphatic tetracarboxylic acid to the diamine compound is preferably in the range of 95 to 105 mol% relative to one of them.

In general, tetracarboxylic dianhydride is used as the tetracarboxylic acid in the production of polyimide resins, but in the above production method, in addition to aliphatic tetracarboxylic dianhydride, aliphatic tetracarboxylic acid or esters of aliphatic tetracarboxylic acid and alcohol may be used to produce practical polyimide resins. If the aliphatic tetracarboxylic acid can be used as it is, it is advantageous in terms of production equipment and cost.

Further, the aliphatic tetracarboxylic dianhydride represented by the formula (1) may be exemplified by: 1,2,3, 4-cyclobutane tetracarboxylic dianhydride, 1,2,4, 5-cyclopentane tetracarboxylic dianhydride, 1,2,4, 5-cyclohexane tetracarboxylic dianhydride, bicyclo [2.2.2] oct-7-ene-2, 3,5, 6-tetracarboxylic dianhydride, and the like.

Further, examples of the aliphatic tetracarboxylic acid represented by the formula (2) and its derivatives include: 1,2,3, 4-cyclobutanetetracarboxylic acid, 1,2,4, 5-cyclopentanetetracarboxylic acid, 1,2,4, 5-cyclohexanedicarboxylic acid, bicyclo [2.2.2] oct-7-ene-2, 3,5, 6-tetracarboxylic acid, and the like, and alcohol esters thereof. These may be used singly or in combination of two or more kinds. Of these, 1,2,4, 5-cyclohexane tetracarboxylic dianhydride and 1,2,4, 5-cyclohexane tetracarboxylic acid are preferable.

In the above production method, other tetracarboxylic acids and derivatives thereof may be used in combination within a range that does not affect the solvent solubility. Examples include: jiao Midan acids, 3',4' -biphenyltetracarboxylic acid, 2, 3',4' -biphenyltetracarboxylic acid, 2-bis (3, 4-dicarboxyphenyl) propane, 2-bis (2, 3-dicarboxyphenyl) propane, 2-bis (3, 4-dicarboxyphenyl) -1, 3-hexafluoropropane 2, 2-bis (2, 3-dicarboxyphenyl) -1, 3-hexafluoropropane, bis (3, 4-dicarboxyphenyl) sulfone, bis (3, 4-dicarboxyphenyl) ether, bis (2, 3-dicarboxyphenyl) ether, 3',4,4' -diphenylketotetracarboxylic acid, 2', 3' -diphenylketotetracarboxylic acid, 4- (p-phenylene dioxy) isophthalic acid, 4- (m-phenylene dioxy) isophthalic acid, ethylene tetracarboxylic acid, 3-carboxymethyl-1, 2, 4-cyclopentanetricarboxylic acid, 1-bis (2, 3-dicarboxyphenyl) ethane, bis (2, 3-dicarboxyphenyl) methane, bis (3, 4-dicarboxyphenyl) methane, and the like, and derivatives thereof. The proportion of these other tetracarboxylic acid components is preferably less than 50 mol% based on the total tetracarboxylic acid components.

The diamine compound is preferably an aromatic diamine compound having 6 to 28 carbon atoms or an aliphatic diamine compound having 2 to 28 carbon atoms. Examples of the diamine compound include: p-phenylenediamine, m-phenylenediamine, 4 '-diamine-biphenyl, 4' -diamine-2, 2 '-dimethylbiphenyl, 4' -diamine-3, 3 '-dimethylbiphenyl, 4' -diamine-2, 2 '-bistrifluoromethyl biphenyl 4,4' -diaminodiphenyl ether, 3,4 '-diaminodiphenyl ether, 4' -diaminodiphenyl methane, 4 '-diaminodiphenyl ketone, 4' -diaminodiphenyl sulfone, 4 '-diaminodiphenyl sulfide 1, 4-bis (4-aminophenoxy) benzene, 1, 3-bis (4-aminophenoxy) benzene, 4' -bis (4-aminophenoxy) biphenyl, bis [4- (4-aminophenoxy) phenyl ] sulfone, 2-bis [4- (4-aminophenoxy) phenyl ] propane aromatic diamine compounds such as 2, 2-bis [4- (4-aminophenoxy) phenyl ] -1, 3-hexafluoropropane, bis [4- (3-aminophenoxy) phenyl ] sulfone, and 9, 9-bis (4-aminobenzene) fluorene; aliphatic diamine compounds such as 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' -diaminodicyclohexylmethane, 3 (4), 8 (9) -bis (aminomethyl) -tricyclo [5.2.1.02,6] decane, m-xylylenediamine, p-xylylenediamine, isophoronediamine, norbornanediamine, and siloxane diamines. These may be used singly or in combination of two or more kinds. Of these diamine compounds, the diamine compound(s), the aromatic diamine compound is preferably 4,4' -diamine-3, 3' -dimethylbiphenyl, 4' -diamine-2, 2' -bistrifluoromethyl biphenyl, 4' -diaminodiphenyl ether, 4' -diaminodiphenyl methane, 1, 4-bis (4-aminophenoxy) benzene, 1, 3-bis (4-aminophenoxy) benzene, 4' -bis (4-aminophenoxy) biphenyl, 2-bis [4- (4-aminophenoxy) phenyl ] propane 2, 2-bis [4- (4-aminophenoxy) phenyl ] -1, 3-hexafluoropropane; the aliphatic diamine compound is preferably 4,4' -diaminodicyclohexylmethane, 3 (4), 8 (9) -bis (aminomethyl) -tricyclo [5.2.1.02,6] decane.

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

Examples of the tertiary amine compound include: trimethylamine, triethylamine, tripropylamine, tributylamine, triethanolamine, N-dimethylethanolamine, N-diethylethanolamine, triethylenediamine, N-methylpyrrolidine, N-ethylpyrrolidine, N-methylpiperidine, N-ethylpiperidine, imidazole, pyridine, quinoline, isoquinoline, and the like. Among these tertiary amine compounds, triethylamine is particularly preferable.

Examples of the solvent used in the above-mentioned production method include: gamma-butyrolactone, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-dimethylformamide, dimethylsulfoxide, hexamethylphosphoramide, sulfolane, p-chlorophenol, m-cresol, 2-chloro-4-hydroxytoluene, and the like. These may be used singly or in combination of two or more kinds. Of these, gamma-butyrolactone, N-dimethylacetamide and N-methyl-2-pyrrolidone are preferable, and gamma-butyrolactone and N, N-dimethylacetamide are more preferable. In addition, a poor solvent for the polyimide resin may be used in combination to such an extent that the polymer does not precipitate. Examples of the poor solvent include: hexane, heptane, benzene, toluene, xylene, chlorobenzene, o-dichlorobenzene, and the like.

The amount of the solvent used in the above-mentioned production method is preferably 1 to 50% by mass, more preferably 20 to 45% by mass, based on the total mass of the reaction solution.

The method of adding the aliphatic tetracarboxylic acid component and the diamine compound component is not particularly limited, and may be carried out by a method of adding two components at a time, or may be carried out by a method of gradually adding one component in a solution containing the other component (not necessarily completely dissolved) in a solid or a solution state, or the like. In particular, the method of adding two components at a time can shorten the addition time, and is advantageous in terms of productivity.

The tertiary amine compound is desirably added before reaching the target temperature after the temperature is raised in order to sufficiently exhibit the catalytic effect. In particular, it is desirable to add the solvent, the aliphatic tetracarboxylic acid component, and the diamine compound simultaneously.

The method of adding the solvent is not particularly limited, and the following methods may be used alone or in combination: a method of adding the catalyst into the reaction tank in advance; a method of adding the catalyst to a reaction tank in which one of an aliphatic tetracarboxylic acid component and a diamine compound is present or to a reaction tank in which both of them are present; and a method in which one of the aliphatic tetracarboxylic acid component and the diamine component is dissolved in advance and then added to the reaction tank. In addition, the solvent as described above may be added to the solvent-soluble polyimide resin solution in a state during the reaction, or to the solvent-soluble polyimide resin solution in a state of remaining in the reaction tank after the reaction, or to the solvent-soluble polyimide resin solution in a state of being taken out from the reaction tank after the reaction, depending on the purpose.

The polyimide resin used in the present embodiment may be, for example, a block copolymer polyimide resin. Examples of such block copolymer polyimide resins include those described in International publication WO 2010-073952. Specifically, the block copolymer polyimide resin is not particularly limited as long as it is a copolymer polyimide resin having a structure in which a structure a and a structure B are alternately repeated, wherein the structure a is an imide oligomer comprising a second structural unit bonded to the terminal of an imide oligomer comprising a first structural unit, and the structure B is an imide oligomer comprising a first structural unit bonded to the terminal of an imide oligomer comprising a second structural unit. The second structural unit is different from the first structural unit. These block-copolymerized polyimide resins can be synthesized by reacting a tetracarboxylic dianhydride with a diamine in a polar solvent to form an imide oligomer, and then further adding a tetracarboxylic dianhydride and another diamine, or adding another tetracarboxylic dianhydride and a diamine, and subjecting the resulting mixture to successive polymerization reactions for imidization.

In the present embodiment, when the polyimide resin is used for the first resin layer 12, the content thereof is not particularly limited, but is preferably in the range of 10 to 90 parts by mass, particularly preferably in the range of 30 to 80 parts by mass, relative to 100 parts by mass of the resin solid content of the first resin layer 12, from the viewpoints of heat resistance and hardenability.

Liquid crystalline polyesters

The liquid crystal polyester is an aromatic polyester which exhibits liquid crystallinity when melted. The liquid crystal polyester can be suitably selected from conventional liquid crystal polyesters. As a conventional liquid crystal polyester, for example, an aromatic polyester described in JP-A2001-11296 can be used. Specifically, aromatic polyesters containing 90 mol% or more of the following structural unit (3) and the like are exemplified.

[ chemical 3]

The aromatic polyester containing the structural unit (3) may be, for example, a polyoxybenzoate ester which is substantially a homopolymer of the structural unit (3) from the viewpoint of availability. The method for producing the aromatic polyester can be a conventional method. The aromatic polyester containing the structural unit (3) is often insoluble or insoluble in a general solvent, and does not exhibit liquid crystallinity due to the refractory or infusibility. Therefore, the aromatic polyester containing the structural unit (3) is preferably used as a powder. The powder is obtained by pulverizing an aromatic polyester resin or fiber, and the particle diameter is preferably set to be equal to or less than the thickness of the first resin layer 12, for example, preferably equal to or less than 5 μm.

Although not particularly limited, the molecular weight of the liquid crystal polyester is usually 1000 to 100000, preferably 10000 to 50000.

As the liquid crystal polyester, commercially available products can be suitably selected and used, and for example, "Ekonols E101-F" manufactured by Sumitomo chemical industry Co., ltd. 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 is preferably in the range of 10 to 90 parts by mass, particularly preferably in the range of 30 to 80 parts by mass, relative to 100 parts by mass of the resin solid content of the first resin layer 12, from the viewpoints of heat resistance and hardenability.

Epoxy compound

The epoxy compound is not particularly limited as long as it is a compound or resin having 1 or more (preferably 2 to 12, more preferably 2 to 6, still more preferably 2 to 4, still more preferably 2 or 3, still more preferably 2) epoxy groups in 1 molecule, and any epoxy compound conventionally known can be used. The epoxy equivalent of the epoxy compound is preferably 250g/eq to 850g/eq, more preferably 250g/eq to 450g/eq, from the viewpoint of further improving the adhesion and flexibility. The epoxy equivalent can be determined by conventional methods.

Specific examples of the epoxy compound include, for example: a compound obtained by epoxidizing a double bond such as a polyoxynaphthylene type epoxy resin, a biphenylaralkyl type epoxy resin, a naphthalene tetrafunctional type epoxy resin, a xylene type epoxy resin, a naphthol aralkyl type epoxy resin, a bisphenol a type epoxy resin, a bisphenol F type epoxy resin, a bisphenol a novolac type epoxy resin, a trifunctional phenol type epoxy resin, a tetrafunctional phenol type epoxy resin, a naphthalene type epoxy resin, a biphenyl type epoxy resin, an aralkyl novolac type epoxy resin, an alicyclic epoxy resin, a polyhydric alcohol type epoxy resin, a glycidylamine type epoxy resin, a epoxypropyl ester type epoxy resin, or butadiene; a compound obtained by reacting a hydroxyl group-containing silicone resin with epichlorohydrin. Among these, in particular, from the viewpoints of copper plating adhesion and flame retardancy, a polyoxynaphthylene type epoxy resin, a biphenyl aralkyl type epoxy resin, a naphthalene tetrafunctional type epoxy resin, a xylene type epoxy resin, and a naphthol aralkyl type epoxy resin are preferable. These epoxy compounds may be used singly or in combination 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 is preferably in the range of 1 to 60 parts by mass, particularly preferably in the range of 1 to 30 parts by mass, relative to 100 parts by mass of the resin solid content of the first resin layer 12, from the viewpoints of heat resistance and hardenability.

Cyanate ester compound

The cyanate ester compound has excellent chemical resistance, adhesion, and other properties, and can form a uniform roughened surface due to its excellent chemical resistance, so that it can be suitably used as a component of the resin layer in the present embodiment.

The cyanate ester compound is not particularly limited as long as it contains 1 or more (preferably 2 to 12, more preferably 2 to 6, still more preferably 2 to 4, still more preferably 2 or 3, still more preferably 2) cyanate groups (cyanooxy groups) in the molecule, and can be widely used in the field of printed circuit boards. Specific examples of the cyanate ester compound include, for example: at least one selected from the group consisting of 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), a biphenyl aralkyl type cyanate ester compound represented by the formula (6), a naphthylene ether type cyanate ester compound, a xylene resin type cyanate ester compound, a triphenol methane type cyanate ester compound, an adamantane skeleton type cyanate ester compound, a bisphenol M type cyanate ester compound, a bisphenol A type cyanate ester compound, and a diallyl bisphenol A type cyanate ester compound. Among these, from the viewpoint of further improving the low water absorbability, at least one selected from the group consisting of an α -naphthol aralkyl type cyanate ester compound represented by formula (4), a phenol novolac type cyanate ester compound represented by formula (5), a biphenyl aralkyl type cyanate ester compound represented by formula (6), a naphthylene ether type cyanate ester compound, a xylene resin type cyanate ester compound, a bisphenol M type cyanate ester compound, a bisphenol a type cyanate ester compound, and a diallyl bisphenol a type cyanate ester compound is desirable. These cyanate ester compounds can be prepared by a conventional method, and commercially available products can 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 cyanate ester compound represented by the formula (6) are preferable because they are excellent in flame retardancy, high in curability, and low in thermal expansion coefficient of the cured product.

[ chemical 4]

In the formula (4), R ¹ Represents a hydrogen atom or a methyl group, n ¹ Is an integer of 1 or more. n is n ¹ And is desirably an integer of 1 to 50.

[ chemical 5]

In the formula (5), R ² Represents a hydrogen atom or a methyl group, n ² Is an integer of 1 or more. n is n ² And is desirably an integer of 1 to 50.

[ chemical 6]

In the formula (6), R ³ Is hydrogen is represented byAn atom or methyl group, n ³ Is an integer of 1 or more. n is n ³ And is desirably an integer of 1 to 50.

In the present embodiment, when the cyanate ester compound is used for the first resin layer 12, the content thereof is not particularly limited, but is preferably in the range of 1 to 60 parts by mass, more preferably in the range of 1 to 30 parts by mass, relative to 100 parts by mass of the resin solid content of the first resin layer 12, from the viewpoints of heat resistance and adhesion to the copper foil.

Maleimide Compounds

Since the maleimide compound can improve the moisture absorption and 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 is not particularly limited as long as it is a compound having 1 or more (preferably 2 to 12, more preferably 2 to 6, still more preferably 2 to 4, still more preferably 2 or 3, still more preferably 2) maleimide groups in 1 molecule, and any maleimide compound conventionally known can be used.

Specific examples of the maleimide compound include, for example: bismaleimide compounds such as bis (4-maleimidophenyl) methane, 2-bis {4- (4-maleimidophenoxy) -phenyl } propane, bis (3, 5-dimethyl-4-maleimidophenyl) methane, bis (3-ethyl-5-methyl-4-maleimidophenyl) methane, and bis (3, 5-diethyl-4-maleimidophenyl) methane; polyphenyl methane maleimide. The composition may be blended as a prepolymer of the maleimide compound or a prepolymer of the maleimide compound and the amine compound. These maleimide compounds may be used singly or in combination of two or more.

Of these, bismaleimide compounds are preferable from the viewpoint of heat resistance, and among them, 2-bis [4- (4-maleimidophenoxy) -phenyl ] propane and bis (3-ethyl-5-methyl-4-maleimidophenyl) methane are more preferable.

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

Phenol Compounds

The phenol compound is not particularly limited as long as it is a phenol compound having 1 or more (preferably 2 to 12, more preferably 2 to 6, still more preferably 2 to 4, still more preferably 2 or 3, still more preferably 2) phenolic hydroxyl groups in 1 molecule, and any phenol compound conventionally known in the art 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 resin, bisphenol a type phenol resin, glycidyl ester type phenol resin, aralkyl phenol resin, biphenyl aralkyl type phenol resin, cresol phenol resin, polyfunctional phenol resin, naphthol phenol resin, polyfunctional naphthol resin, anthracene type phenol resin, naphthalene skeleton modified phenol resin, phenol aralkyl type phenol resin, naphthol aralkyl type phenol resin, dicyclopentadiene type phenol resin, biphenyl type phenol resin, alicyclic type phenol resin, polyhydric alcohol type phenol resin, phosphorus-containing phenol resin, hydroxyl-containing silicone resin, and the like. These phenol compounds may be used singly or in combination of two or more.

Polyphenylene ether compound

The polyphenylene ether compound of the present embodiment is a compound represented by general formula (7). By containing the polyphenylene ether compound, insulation properties, plating adhesion properties, and moisture and 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 to 7000. By setting the number average molecular weight to 7000 or less, the compatibility of resins can be controlled. Further, by setting the number average molecular weight to 1000 or more, excellent insulation and moisture absorption heat resistance which are inherent in polyphenylene ether resins can be obtained. Among them, the number average molecular weight of the polyphenylene ether compound may be 1100 to 5000 in order to obtain more excellent compatibility, insulation property, and moisture absorption heat resistance. The number average molecular weight of the polyphenylene ether compound is more preferably 4500 or less, and still more preferably 3000 or less. The number average molecular weight is determined by conventional methods using a gel permeation chromatograph.

[ chemical 7]

(in the general formula (7), X represents an aryl group (aromatic group), - (Y-O) n) ₂ -is a polyphenylene ether moiety, R ₁ 、R ₂ 、R ₃ Each independently represents a hydrogen atom, an alkyl group, an alkenyl group or an alkynyl group, n ₂ Is an integer of 1 to 100, n ₁ Is an integer of 1 to 6, n ₃ Is an integer of 1 to 4. n is n ₁ It is preferably an integer of 1 to 4 inclusive, n ₁ Further desirably 1 or 2, in the ideal case n ₁ May be 1. In addition, n ₃ It is preferably an integer of 1 to 3, n ₃ Further desirably 1 or 2, in the ideal case n ₃ May be 2. )

The polyphenylene ether compound represented by the general formula (7) is preferably a polymer containing a constituent unit represented by the following general formula (8).

[ chemical 8]

(in general formula (8), R ₉₀₁ 、R ₉₀₂ 、R ₉₀₃ 、R ₉₀₄ Each independently represents an alkyl group having 6 or less carbon atoms, an aryl group, a halogen atom, or a hydrogen atom. )

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

[ chemical 9]

(in general formula (9), R ₉₀₅ 、R ₉₀₆ 、R ₉₀₇ 、R ₉₁₁ 、R ₉₁₂ Each independently represents an alkyl group having 6 or less carbon atoms or a phenyl group. R is R ₉₀₈ 、R ₉₀₉ 、R ₉₁₀ Each independently represents a hydrogen atom, an alkyl group having 6 or less carbon atoms, or a phenyl group. )

[ chemical 10]

(in general formula (10), R ₉₁₃ 、R ₉₁₄ 、R ₉₁₅ 、R ₉₁₆ 、R ₉₁₇ 、R ₉₁₈ 、R ₉₁₉ 、R ₉₂₀ Each independently represents a hydrogen atom, an alkyl group having 6 or less carbon atoms, or a phenyl group. -a-linear, branched or cyclic divalent hydrocarbon group having 20 or less carbon atoms. )

In relation to the general formula (7), the general formulae (8), (9) and (10) are preferably- (Y-O) -, which is represented by the general formula (7). - (Y-O) -system having n ₂ The number of repeating units of (1-100).

As the aryl group in X of the general formula (7), an aromatic hydrocarbon group can be used. Specifically, removal of n from one ring structure selected from the group consisting of a benzene ring structure, a biphenyl structure, an indene ring structure, and a naphthalene ring structure can be used ₃ The group having a hydrogen atom (e.g., phenyl, biphenyl, indenyl, and naphthyl) is preferably biphenyl. Here, the aryl group may also contain: the above aryl group may be a diphenyl ether group or the like bonded through an oxygen atom, a diphenyl ketone group or the like bonded through a carbonyl group, or a 2, 2-diphenylpropyl group or the like bonded through an alkylene group. In addition, 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, the foregoing "aryl" is substituted with a polyphenylene ether moiety via an oxygen atom, and thus the number of substituents is generally limited depending on the number of polyphenylene ether moieties.

The polyphenylene ether compound is particularly preferably a polyphenylene ether compound represented by the following general formula (11).

[ chemical 11]

(in the general formula (11), X is an aryl group (aromatic group), - (Y-O) n) ₂ -each represents a polyphenylene ether moiety, n ₂ Are integers of 1 to 100. )

-(Y-O)n ₂ -and n ₂ Is synonymous with that in general formula (7). May also include a plurality of different n ₂ Is a compound of (a).

X in the general formulae (7) and (11) is preferably general formula (12), general formula (13), or general formula (14); - (Y-O) n in general formula (7) and general formula (11) ₂ It is further preferable that the structure of the general formula (15) or the general formula (16) is arranged, or that the structure of the general formula (15) and the general formula (16) are arranged randomly.

[ chemical 12]

[ chemical 13]

(in general formula (13), R ₉₂₁ 、R ₉₂₂ 、R ₉₂₃ 、R ₉₂₄ Each independently represents a hydrogen atom or a methyl group. -a linear, branched or cyclic divalent hydrocarbon group having 20 or less carbon atoms in the B-system. )

[ chemical 14]

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

[ 15]

[ 16]

The method for producing the modified polyphenylene ether having the structure represented by the general formula (11) is not particularly limited, and for example, the modified polyphenylene ether can be produced by subjecting a terminal phenolic hydroxyl group of a bifunctional phenylene ether oligomer obtained by oxidative coupling of a bifunctional phenol compound and a monofunctional phenol compound to vinylbenzyl etherification.

As the modified polyphenylene ether, commercially available products such as OPE-2St1200 and OPE-2St2200 manufactured by Mitsubishi gas chemical corporation can be used as appropriate.

In the present embodiment, when the polyphenylene ether compound is used in the first resin layer 12, the content thereof is not particularly limited, but is preferably 1 part by mass or more, more preferably 3 parts by mass or more, per 100 parts by mass of the resin solid content of the first resin layer 12. The upper limit of the content is preferably less than 20 parts by mass. By setting the range as above, interlayer adhesion, plating adhesion, and moisture absorption heat resistance can be effectively improved. The first resin layer 12 may contain only one kind of polyphenylene ether compound or may contain two or more kinds of polyphenylene ether compounds. When two or more types are contained, the total amount is preferably within the above range.

Benzoxazine compounds

The benzoxazine compound is not particularly limited as long as it is a compound having 2 or more dihydrobenzoxazine rings in 1 molecule, and generally a conventional compound can be used. Specific examples of the benzoxazine compound include, for example: bisphenol A type benzoxazine BA-BXZ (trade name, manufactured by Small Western Co., ltd.), bisphenol F type benzoxazine BF-BXZ (trade name, manufactured by Small Western Co., ltd.), bisphenol S type benzoxazine BS-BXZ (trade name, manufactured by Small Western Co., ltd.), and the like. These benzoxazine compounds may be used singly or in combination of two or more.

Organic-modified silicone compounds

The organic group-modified silicone compound is not particularly limited, and specific examples thereof include: di (methylamine) polydimethylsiloxane, di (ethylamine) polydimethylsiloxane, di (propylamine) polydimethylsiloxane, di (epoxypropyl) polydimethylsiloxane, di (epoxybutyl) polydimethylsiloxane. These organic-based modified silicone compounds may be used singly or in combination of two or more.

Compounds having polymerizable unsaturated groups

The compound having a polymerizable unsaturated group is not particularly limited, and a conventional compound can be generally used. Specific examples of the compound having a polymerizable unsaturated group include, for example: vinyl compounds such as ethylene, propylene, styrene, divinylbenzene, and divinylbenzene; mono-or polyhydric alcohol (meth) acrylates such as methyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, polypropylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, neopentyl glycol tetra (meth) acrylate, and dipentaerythritol hexa (meth) acrylate; epoxy (meth) acrylates such as bisphenol a type epoxy (meth) acrylate and bisphenol F type epoxy (meth) acrylate; benzene ring butene resin, etc. These compounds having a polymerizable unsaturated group may be used singly or in combination of two or more.

Inorganic filler (B1) >)

The inorganic filler (B1) means an inorganic filler contained in the first resin layer 12 (i.e., the first resin composition). The inorganic filler (B1) is not particularly limited as long as it is spherical filler used for the insulating layer of the printed wiring board, and spherical filler can be used from the viewpoints of low thermal expansion coefficient, moldability, filling property and rigidity.

Examples of the inorganic filler (B1) include: magnesium hydroxide; magnesium oxide; silica such as natural silica, fused silica, amorphous silica, and hollow silica; molybdenum compounds such as molybdenum disulfide, molybdenum oxide, and zinc molybdate; alumina; aluminum nitride; glass; talc; titanium compounds such as titanium oxide, barium titanate, and strontium titanate; zirconia, and the like. These may be used singly or as a mixture of two or more.

Among them, the inorganic filler (B1) is preferably silica, more specifically, spherical fused silica, from the viewpoint of low thermal expansion. Commercially available spherical fused silica may be exemplified by: SC2050-MB, SC2500-SQ, SC4500-SQ, SO-C2, SO-C1, K180SQ-C1 manufactured by Admatechs, inc.; m273 manufactured by CIK NanoTek Co., ltd; SFP-130MC manufactured by electric Co., ltd.

The particle diameter of the inorganic filler (B1) is not particularly limited, but is preferably set to be not more than the film thickness of the first resin layer 12, for example, not more than 5 μm, more preferably not more than 3 μm, still more preferably not more than 2 μm, still more preferably not more than 1.0 μm. The particle size of the inorganic filler (B1) can be measured by a laser diffraction/scattering method based on Mie scattering theory. For the measurement of the sample, a sample in which the inorganic filler (B1) is dispersed in water by ultrasonic waves can be preferably used. As a laser diffraction scattering type particle size distribution measuring apparatus, for example, "MT3000II" manufactured by microtracB Co., ltd.

The inorganic filler (B1) may be surface-treated with a silane coupling agent or the like. The silane coupling agent may be a silane coupling agent described later.

[ second resin layer ]

The second resin layer 13 is composed of a second resin composition containing 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. The reason is that: if the content of the inorganic filler (B2) is larger than this value, flexibility is lowered and cracks are likely to occur, whereas if the content of the inorganic filler (B2) is smaller than this value, the scum removability is lowered. The content of the inorganic filler (B2) refers to the content of the inorganic filler (B2) relative to the second resin composition (inorganic filler (B2)/second resin composition×100).

The total content of the inorganic filler (B1) and the inorganic filler (B2) (total inorganic filler content) is preferably 2.5% by volume or more and 33.3% by volume or less, relative to the total of the first resin composition and the second resin composition. The reason is that: within this range, the occurrence of cracks can be suppressed, and the removal of the gum residue can be improved.

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 from the viewpoint of ensuring insulation properties. The second resin layer 13 is desirably in a semi-cured state (B-Stage). The second resin layer 13 can be formed by a known method such as coating using a second resin composition. The second resin composition may optionally contain other additives which will be described later.

< thermosetting resin (A2) >)

The thermosetting resin (A2) is not particularly limited, and examples thereof include: epoxy compounds, cyanate ester compounds, maleimide compounds, phenol compounds, polyphenylene ether compounds, benzoxazine compounds, organomodified silicone compounds, and compounds having polymerizable unsaturated groups. The compounds may be the same as those exemplified for the thermosetting resin (A1). One of these may be used, or two or more of these may be suitably mixed for use. Among them, the epoxy compound and the phenol compound are preferable because excellent peel strength can be obtained; it is more preferable that the epoxy compound and the phenol compound further contain a maleimide 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 is preferably in the range of 10 to 80 parts by mass, particularly preferably in the range of 30 to 70 parts by mass, relative to 100 parts by mass of the resin solid content of the second resin layer 13, from the viewpoints of heat resistance and hardenability.

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

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

Inorganic filler (B2) >)

The inorganic filler (B2) means an inorganic filler contained in the second resin layer 13 (i.e., the second resin composition). The inorganic filler (B2) is not particularly limited as long as it is spherical filler used for the insulating layer of the printed wiring board, and spherical filler can be used from the viewpoints of low thermal expansion coefficient, moldability, filling property and rigidity. The inorganic filler (B2) may be exemplified as the inorganic filler (B1), and among them, silica, specifically, spherical fused 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 Components ]

As described above, the first resin layer 12 and the second resin layer 13 of the present embodiment may each optionally contain other components.

Other components, for example, silane coupling agents may be contained for the purpose of improving moisture absorption and 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 an inorganic substance. Specific examples thereof include: aminosilane-based silane coupling agents (e.g., gamma-aminopropyl triethoxysilane, N-beta- (aminoethyl) -gamma-aminopropyl trimethoxysilane), epoxysilane-based silane coupling agents (e.g., gamma-glycidoxypropyl trimethoxysilane), acryl silane-based silane coupling agents (e.g., gamma-acryloxypropyl trimethoxysilane), vinyl silane-based silane coupling agents (e.g., gamma-methacryloxypropyl trimethoxysilane), cationic silane-based silane coupling agents (e.g., N-beta- (N-vinylbenzylaminoethyl) -gamma-aminopropyl trimethoxysilane hydrochloride), phenylsilane-based silane coupling agents, and the like. These silane coupling agents may be used singly or in combination of two or more.

In this embodiment, the content of the silane coupling agent is not particularly limited, but is preferably in the range of 0.05 to 5 parts by mass, more preferably in the range of 0.1 to 3 parts by mass, per 100 parts by mass of the inorganic filler (B1) or the inorganic filler (B2) from the viewpoint of improving the moisture absorption and heat resistance. When two or more silane coupling agents are used in combination, the total amount of these agents is preferably in the range described above.

Other components may contain a wetting dispersant for the purpose of improving manufacturability, for example. The wetting and dispersing agent is not particularly limited as long as it is a wetting and dispersing agent generally used for paint and the like. Specific examples thereof include: disperbyk (registered trademark) -110, disperbyk-111, disperbyk-118, disperbyk-180, disperbyk-161, BYK (registered trademark) -W996, BYK-W9010, BYK-W903, etc. manufactured by BYK Japan Co., ltd. These wetting and dispersing agents may be used singly or in combination.

In the present embodiment, the content of the wetting dispersant is not particularly limited, but is preferably in the range of 0.1 to 5 parts by mass, more preferably in the range of 0.5 to 3 parts by mass, per 100 parts by mass of the inorganic filler (B1) or the inorganic filler (B2) from the viewpoint of improving manufacturability. When two or more types of wetting and dispersing agents are used in combination, the total amount of these agents is preferably in the range described above.

Other components may contain a hardening accelerator for the purpose of adjusting the hardening rate, for example. The hardening accelerator is not particularly limited, and examples thereof include: organometallic salts containing metals such as copper, zinc, cobalt, nickel, manganese (e.g., lead naphthenate, lead stearate, zinc naphthenate, zinc octoate, tin oleate, dibutyl tin malate, manganese naphthenate, cobalt naphthenate, nickel octoate, manganese octoate, iron acetylacetonate); dissolving the organic metal salts in hydroxyl-containing compounds such as phenol and bisphenol; organotin compounds (for example, inorganic metal salts such as tin chloride, zinc chloride, aluminum chloride, dioctyltin oxide, other alkyltin, alkyltin oxide); imidazoles and derivatives thereof (e.g., 2-ethyl-4-methylimidazole, 1-benzyl-2-phenylimidazole, 2,4, 5-triphenylimidazole); tertiary amines (e.g., triethylamine, N-dimethylbenzylamine, N-dimethylaniline, N-dimethylbenzylamine, 2-N-ethylanilino ethanol, tri-N-butylamine, pyridine, quinoline, N-methylmorpholine, triethanolamine, triethylenediamine, tetramethylbutanediamine, N-methylpiperidine, etc.); organic peroxides (e.g., benzoyl peroxide, lauroyl peroxide, acetyl peroxide, p-chlorobenzoyl peroxide, di-tert-butyl diperoxyphthalate); azo compounds (e.g., azodinitrile); phenols (e.g., phenol, xylenol, cresol, resorcinol, catechol). These hardening accelerators may be used singly or in combination.

In the present embodiment, the content of the hardening accelerator is not particularly limited, but is preferably in the range of 0.001 to 5 parts by mass, more preferably in the range of 0.01 to 3 parts by mass, per 100 parts by mass of the resin solid content of the first resin layer 12 or the second resin layer 13, from the viewpoint of obtaining a high glass transition temperature. In the case where two or more hardening accelerators are used in combination, the total amount of these accelerators is preferably in a range satisfying the above-mentioned range.

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

The polymer compound includes various thermosetting resins, thermoplastic resins, oligomers thereof, elastomers thereof, and the like, in addition to the thermosetting resin (A1) or the thermosetting resin (A2). Specifically, there may be mentioned: polyimide resins, polyamideimide resins, polystyrene, polyolefin, styrene-butadiene rubber (SBR), isoprene Rubber (IR), polybutadiene rubber (BR), acrylonitrile butadiene rubber (NBR), polyurethane, polypropylene, (meth) acrylic oligomers, (meth) acrylic polymers, silicone resins, and the like. From the standpoint of compatibility, acrylonitrile butadiene rubber or styrene-butadiene rubber is desirable.

Specific examples of the flame retardant compound include, in addition to the inorganic filler (B1) or the inorganic filler (B2): phosphorus-containing compounds (e.g., phosphate esters, melamine phosphate, phosphorus-containing epoxy resins); nitrogen-containing compounds (e.g., melamine, benzoguanamine); oxazine ring-containing compounds; silicone compounds, and the like. These polymer compounds and/or flame retardant compounds may be used singly or in combination.

The first resin layer 12 and the second resin layer 13 may contain other various additives for various purposes. Specific examples of the additives include: ultraviolet light absorber, antioxidant, photopolymerization initiator, fluorescent whitening agent, photosensitizer, dye, pigment, thickener, lubricant, defoamer, dispersant, leveling agent and gloss agent. These additives may be used singly or in combination of two or more.

[ method for producing resin layer-attached copper foil ]

The method for producing the resin layer-attached copper foil 10 of the present embodiment is not particularly limited. As a manufacturing method, for example, a solution (varnish) in which the first resin composition is dissolved or dispersed in an organic solvent is first applied to the surface of the copper foil 11, and then heated and/or dried under reduced pressure to remove the solvent and cure the first resin composition, thereby forming the first resin layer 12. As described above, the first resin layer 12 may be in a half-cured state or a completely cured state. Subsequently, a solution (varnish) of the second resin composition dissolved or dispersed in an organic solvent is applied on the first resin layer 12, followed by heating and/or drying under reduced pressure to remove the solvent and cure the second resin composition, thereby forming the second resin layer 13. In this case, the second resin layer 13 is preferably in a B-stage (semi-cured state). A protective layer such as a plastic film may be provided on the second resin layer 13. The protective layer is suitably removed during the production of a laminate to be described later.

The drying conditions are not particularly limited, and the first resin layer 12 or the second resin layer 13 is dried, and the organic solvent is usually 10 parts by mass or less, preferably 5 parts by mass or less, per 100 parts by mass. The conditions for achieving drying vary depending on the amount of the organic solvent in the varnish, and for example, when the varnish contains 30 to 60 parts by mass of the organic solvent per 100 parts by mass of the varnish, the varnish can be dried under heating at 50 to 200 ℃ for about 3 to 10 minutes.

The organic solvent is not particularly limited as long as each component can be dissolved or dispersed appropriately and the effect of the first resin layer 12 or the second resin layer 13 can be exerted. Specific examples of the organic solvent include: alcohols (e.g., methanol, ethanol, and propanol); ketones (e.g., acetone, methyl ethyl ketone, and methyl isobutyl ketone); amides (e.g., dimethylacetamide and dimethylformamide); aromatic hydrocarbons (e.g., toluene and xylene); n-methyl-2-pyrrolidone, gamma-butyrolactone, and the like. These organic solvents may be used singly or in combination of two or more.

The coating method is not particularly limited, and for example, may be used: bar coater coating, air knife coating, gravure coating, reverse gravure coating, micro reverse gravure coater coating, die coater coating, dip coating, spin coating, spray coating, and the like.

Laminate and method for producing the same

The laminate using the resin layer-attached copper foil 10 of the present embodiment (hereinafter, simply referred to as "laminate of the present embodiment") can be used, for example, for the use of build-up materials for printed wiring boards or substrates for mounting semiconductor devices, and for the use of manufacturing coreless substrates.

The laminate of the present embodiment may be configured as a laminate having a build-up layer, for example, in which the build-up conductor layer and the insulating layer formed by using the copper foil 10 with a resin layer are alternately laminated. The term "insulating layer formed using the resin layer-attached copper foil 10" means, for example, a structure that can be laminated on a substrate on which a conductor layer is formed so as to be in contact with the second resin layer 13 of the resin layer-attached copper foil 10. In the case of forming an insulating layer using three or more resin layer-attached copper foils 10, the copper foil 11 may be removed as needed, and the first resin layer 12 and the second resin layer 13 may be laminated to form an insulating layer. The conductor layer may be formed by laminating another conductor (copper foil or the like) such as a copper foil of a copper-clad laminate by the copper foil 11 of the resin-layer-attached copper foil 10. Fig. 2 shows an example of the laminate 20 according to the present embodiment. The laminate 20 is formed by laminating a copper foil 10 with a resin layer on a substrate 22 with a conductor layer 21 formed thereon so as to be in contact with a second resin layer 13, and an insulating layer 23 is formed by the first resin layer 12 and the second resin layer 13.

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 insulating layers, and the conductor layers may be arranged between the insulating layers and on the surface of the outermost layer of the build-up layer. In this case, the number of insulating layers is not particularly limited, and may be three or four layers, for example.

In addition, the laminate of the present embodiment can be used to manufacture a coreless substrate. The coreless substrate may be, for example, a two-layer coreless substrate or a three-layer coreless substrate. The structure of the coreless substrate will be described later.

[ printed Circuit Board ]

The laminate system of the present embodiment can be used as a printed circuit board. In this case, a printed wiring board is obtained by using a laminate in which the resin layer-attached copper foil 10 of the present embodiment is used as a build-up material, with respect to a metal-clad laminate in which an insulating resin layer called a core substrate has been completely cured. When the resin layer-attached copper foil 10 (laminate) of the present embodiment is used, a thin printed wiring board can be manufactured without using a thick support substrate (carrier substrate), for example.

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

In the present embodiment, the build-up layer means the first resin layer 12 and the second resin layer 13 in the copper foil 10 having the resin layer attached to the metal foil and/or the conductor laminate layer on the surface of the metal foil laminate.

In the manufacture of printed circuit boards, holes such as through holes and/or perforations are formed as necessary to electrically connect the conductor layers. Hole processing is usually performed by mechanical drilling, carbon dioxide laser, UV laser, YAG laser, or the like. In the insulating layer formed by using the resin layer-attached copper foil 10, occurrence of cracks can be suppressed at the time of formation of the through holes, and at the same time, the removal property of the mold residue can be improved, and further, overhang can be suppressed. Therefore, in both the conformal laser processing and the direct laser processing, a good processing shape can be obtained.

In the case where the hole processing has been performed, a roughening treatment including desmear treatment is then performed. The roughening treatment generally comprises a swelling step, a surface roughening step, a glue residue dissolving step, and a neutralization step. The swelling step is performed by swelling the surface of the insulating resin layer with a swelling agent. The swelling agent is not particularly limited as long as it can enhance the wettability of the surface of the insulating resin layer to such an extent that the surface of the insulating resin layer is swelled to promote oxidative decomposition in the subsequent surface roughening and desmear dissolving steps. Examples thereof include alkaline solutions and surfactant solutions. The surface roughening and the glue residue dissolving steps are performed by using an oxidizing agent. The oxidizing agent may be, for example, an alkaline permanganate solution, and specific examples thereof include an aqueous potassium permanganate solution and an aqueous sodium permanganate solution. The oxidizing agent treatment is called wet desmear, but in addition to the wet desmear, it may be suitably performed in combination with dry desmear by plasma treatment or UV treatment, mechanical polishing by a polisher or the like, sand blasting, and other conventional roughening treatments. A neutralization step of neutralizing the oxidizing agent used in the preceding step with a reducing agent. The reducing agent may be an amine-based reducing agent, and specific examples thereof include an aqueous acidic solution such as an aqueous hydroxylamine sulfate solution, an aqueous ethylenediamine tetraacetic acid solution, or an aqueous nitrilotriacetic acid solution.

In this embodiment, it is preferable that the metal plating treatment is performed after the formation of the through-holes and/or the perforations or after the desmear treatment is performed in the through-holes and/or the perforations, so as to electrically connect the conductor layers. The method of the metal plating treatment is not particularly limited, and a method of the metal plating treatment in the production of a usual multilayer printed wiring board can be suitably used. The method of the metal plating treatment and the type of the chemical solution used for plating are not particularly limited, and a method of the metal plating treatment and the chemical solution used in the production of a usual multilayer printed wiring board can be suitably used. The chemical solution used for the metal plating treatment may be commercially available. The metal plating treatment method is not particularly limited, and examples thereof include: treatment with degreasing liquid, treatment with soft etching liquid, acid washing, treatment with prepreg liquid, treatment with catalytic liquid, treatment with accelerating liquid, treatment with chemical copper liquid, acid washing, and treatment with copper sulfate liquid and application of electric current.

In addition, when the half-cured resin layer-attached copper foil 10 is used for lamination, the half-cured first resin layer 12 or the half-cured second resin layer 13 may be subjected to heat treatment or the like to be fully cured, whereby a printed circuit board is obtained. In the present embodiment, another resin layer-attached copper foil 10 may be further laminated on the obtained printed circuit board.

The lamination method in the build-up method is not particularly limited, and a vacuum pressure laminator may be suitably used. In this case, the resin layer-attached copper foil 10 may be laminated with an elastomer such as rubber. The lamination conditions are not particularly limited as long as they are the conditions used in lamination of a usual printed circuit board, and are, for example, at a temperature of 70 to 140℃and 1kgf/cm ² ～11kgf/cm ² The contact pressure of the above-mentioned method is in a range of 20hPa or less. After the lamination step, the laminated adhesive film may also be smoothed by hot pressing of the metal plate. The lamination step and the smoothing step can be performed continuously by a commercially available vacuum-pressurized laminator. There may also be a heat hardening step after the lamination step or after the smoothing step. By using a heat hardening step, the first resin can be madeThe layer 12 and the second resin layer 13 are completely cured. The heat curing conditions vary depending on the types of components contained in the first resin layer 12 and the second resin layer 13, and the curing temperature is usually 100 to 300℃and the pressure is 0.1kgf/cm ² ～100kgf/cm ² (about 9.8kPa to about 9.8 MPa) and the curing time is 30 seconds to 5 hours.

The method of forming a circuit pattern on the copper foil on one or both sides of the printed circuit board of the present embodiment includes: semi-addition, complete addition, subtraction, etc. Among them, the half-addition method is preferable from the viewpoint of forming a fine circuit pattern.

As an example of a method of forming a circuit pattern by the half-additive method, there is a method of selectively applying plating (pattern plating) using a plating resist, and then peeling off the plating resist and etching the whole appropriately to form a circuit pattern. In the formation of the circuit pattern by the half-additive method, electroless plating and electroplating are performed in combination, and in this case, drying is preferably performed after electroless plating and after electroplating, respectively. Drying after electroless plating is not particularly limited, but is preferably carried out at 80 to 180℃for 10 to 120 minutes; drying after plating is not particularly limited, but is preferably performed at 130 to 220℃for 10 to 120 minutes, for example. The plating is desirably copper plating.

An example of a method of forming a circuit pattern by a subtractive method is a method of forming a circuit pattern by selectively removing a conductor layer using an etching resist. Specifically, the process can be performed as follows, for example. A dry film resist (RD-1225 (trade name) manufactured by Hitachi chemical Co., ltd.) was laminated (laminated) on the entire surface of the copper foil at a temperature of 110.+ -. 10 ℃ and a pressure of 0.50.+ -. 0.02 MPa. Then, exposure is performed along the circuit pattern, and masking is performed. Then, the dry film photoresist is developed in 1% sodium carbonate aqueous solution, and finally the dry film photoresist is stripped by an amine-based photoresist stripper. Thus, a circuit pattern can be formed on the copper foil.

In the present embodiment, the insulating resin layer and/or the conductor layer may be further laminated on the printed wiring board, thereby obtaining a multilayer printed wiring board. The inner layer of the multi-layer printed circuit board may also have a circuit substrate therein. The copper foil 10 with resin layer is one of insulating resin layer and conductor layer of the multi-layer printed circuit board.

The lamination method is not particularly limited, and a method generally used for lamination molding of a normal printed circuit board can be used. Examples of the lamination 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 lamination is not particularly limited, and is suitably selected in the range of 100℃to 300℃for example; the pressure is not particularly limited, and is, for example, 0.1kgf/cm ² ～100kgf/cm ² (about 9.8kPa to about 9.8 MPa); the heating time is not particularly limited, and is suitably selected from the range of 30 seconds to 5 hours, for example. In addition, the post-hardening may be performed, for example, at a temperature ranging from 150 to 300℃to adjust the hardening degree, if necessary.

[ substrate for mounting semiconductor device ]

As described above, the laminate system of the present embodiment can be used as a substrate for mounting a semiconductor device. The substrate for mounting a semiconductor device is produced, for example, by laminating a resin layer-attached copper foil 10 on a metal foil-clad laminate, and masking and patterning the copper foil on the surface or one side of the obtained laminate. The mask and patterning may be any known mask and patterning used in the manufacture of printed circuit boards, and is not particularly limited, but it is desirable to form a circuit pattern by the above-mentioned subtractive method. The circuit pattern may be formed on only one side of the laminate, or may be formed on both sides of the laminate.

[ multilayer coreless substrate (multilayer printed Circuit Board) ]

The laminate of the present embodiment may be a coreless substrate as described above. An example of the coreless substrate is a multilayer coreless substrate.

The multilayer coreless substrate may be configured, for example: the first insulating layer and the second insulating layer each 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. A specific example of the multilayer coreless substrate will be described with reference to fig. 3. Fig. 3 is a schematic diagram showing an example of the multilayer coreless substrate according to the present embodiment. The multilayer coreless substrate 100 shown in fig. 3 includes a first insulating layer 111 and two second insulating layers 112 laminated on one side direction (upper direction in the drawing) of the first insulating layer 111, and the first 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 one resin layer-attached copper foil 10, respectively. The multilayer coreless substrate 100 shown in fig. 3 has a plurality of conductor layers, and the plurality of conductor layers are composed of a first conductor layer 113 disposed between a plurality of insulating layers (a first insulating layer 111 and a second insulating layer 112) and a second conductor layer 114 disposed on the outermost layer of the plurality of insulating layers (the first insulating layer 111 and the second insulating layer 112).

Thus, according to the present embodiment, when forming the through hole, occurrence of cracks can be suppressed, and at the same time, the scum removability can be improved, and overhang can be suppressed. Therefore, a good processing shape can be obtained in both conformal laser processing and direct laser processing.

Examples (example)

Hereinafter, the present invention will be described more specifically by using examples and comparative examples, but the present invention is not limited to these examples.

Example 1

15.0 parts by mass of a polyphenylene ether compound (product name: OPE-2St2200, mitsubishi gas chemical Co., ltd.), 49.9 parts by mass of a polyimide resin (product name: neopulim (registered trademark) S100, mitsubishi gas chemical Co., ltd.), 34.9 parts by mass of 2, 2-bis- (4- (4-maleimidophenoxy) phenylpropane (product name: BMI-80, manufactured by K.I. chemical Co., ltd.), and 0.2 parts by mass of 2,4, 5-triphenylimidazole (manufactured by Tokyo chemical Co., ltd.) were blended to obtain a first resin composition, that is, an inorganic filler was not added to the first resin composition, then, the first resin composition was diluted with N-methyl-2-pyrrolidone (hereinafter, referred to as "NMP") to obtain a varnish A. The obtained varnish A was coated on a copper foil 11 (product name: MT-FL, manufactured by means of Mitsubishi gas chemical Co., ltd.) having a thickness of 3 μm by a bar coater, and a mat film was formed by heating at 180℃for 10 minutes on the upper surface of a copper foil, and then a mat was formed.

Further, 35.8 parts by mass of a biphenyl aralkyl type phenol resin (product name: KAYAHARD GPH-103, hydroxyl equivalent: 231g/eq., manufactured by Japanese chemical Co., ltd.), 17.9 parts by mass of bis (3-ethyl-5-methyl-4-maleimide diphenyl) methane (product name: BMI-70, manufactured by K.I. chemical Co., ltd.), 7.0 parts by mass of a naphthalene aralkyl type epoxy resin (product name: HP-9900, epoxy equivalent: 274g/eq., manufactured by DIC Co., ltd.), 38.8 parts by mass of a biphenyl aralkyl type epoxy resin (product name: NC-3000-FH, manufactured by Japanese chemical Co., ltd., epoxy equivalent: 320 g/eq.), 0.5 parts by mass of 2,4, 5-triphenyl imidazole (manufactured by Tokyo chemical Co., ltd.), and silica (product name: M, average particle size: 0.1 μm, manufactured by CIK.Tek.) as an inorganic filler (B2) were blended, whereby a second resin composition was obtained. At this time, the content of silica as the inorganic filler (B2) (inorganic filler (B2)/second resin composition×100) was 15% by volume with respect to the second resin composition. Subsequently, the second resin composition was diluted with methyl ethyl ketone, thereby obtaining varnish B. The obtained varnish B was coated on the first resin layer 12 obtained by the above-described method by a bar coater. Subsequently, the coating film was subjected to heat drying at 150 ℃ for 10 minutes, thereby obtaining a resin layer-attached copper foil 10 having a first resin layer 12 and a second resin layer 13.

The thickness of the first resin layer 12 was set to 5 μm, and the thickness of the second resin layer 13 was set to 1 μm. The total content of the inorganic filler (B1) and the inorganic filler (B2) (total inorganic filler content) was 2.5% by volume based on the total of the first resin composition and the second resin composition.

Example 2

The first resin layer 12 was formed on the copper foil 11 in the same manner as in example 1, except that silica (product name: K180SQ-C1, average particle diameter 0.18 μm, manufactured by Admatechs Co., ltd.) as the inorganic filler (B1) was blended (mixed) into the first resin composition, and the thickness of the first resin layer 12 was set to 2.5. Mu.m. At this time, the content of silica as the inorganic filler (B1) (inorganic filler (B1)/first resin composition×100) was 14% by volume with respect to the first resin composition.

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

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

Example 4

The first resin layer 12 was formed on the copper foil 11 in the same manner as in example 1 except that silica (product name: K180SQ-C1, average particle diameter 0.18 μm, manufactured by Admatechs Co., ltd.) as the inorganic filler (B1) was blended (mixed) into the first resin composition, and the thickness of the first resin layer 12 was 1. Mu.m. At this time, the content of silica as the inorganic filler (B1) (inorganic filler (B1)/first resin composition×100) was 14% by volume with respect to the first resin composition.

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

Example 5

The first resin layer 12 was formed on the copper foil 11 in the same manner as in example 1, except that silica (product name: K180SQ-C1, average particle diameter 0.18 μm, manufactured by Admatechs Co., ltd.) as the inorganic filler (B1) was blended (mixed) into the first resin composition, and the thickness of the first resin layer 12 was set to 2.5. Mu.m. At this time, the content of silica as the inorganic filler (B1) (inorganic filler (B1)/first resin composition×100) was 1.1% by volume with respect to the first resin composition.

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

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 set to 2.5. Mu.m. That is, no inorganic filler is added to the first resin composition. The second resin layer 13 was formed on the first resin layer 12 in the same manner as in example 1, except that no inorganic filler was added to the second resin composition, and the thickness of the second resin layer 13 was set to 5. Mu.m. The total content of the inorganic filler (B1) and the inorganic filler (B2) (total inorganic filler content) was 0.0% by volume based on the total of the first resin composition and the second resin composition.

Comparative example 2

The first resin layer 12 was formed on the copper foil 11 in the same manner as in example 1, except that silica (product name: K180SQ-C1, average particle diameter 0.18 μm, manufactured by Admatechs Co., ltd.) as the inorganic filler (B1) was blended (mixed) into the first resin composition, and the thickness of the first resin layer 12 was set to 2.5. Mu.m. At this time, the content of silica as the inorganic filler (B1) (inorganic filler (B1)/first resin composition×100) was 15% by volume with respect to the first resin composition.

The second resin layer 13 was formed on the first resin layer 12 in the same manner as in example 1, except that no inorganic filler was added to the second resin composition, and the thickness of the second resin layer 13 was set to 5. Mu.m. The total content of the inorganic filler (B1) and the inorganic filler (B2) (total inorganic filler content) was 5.0% by volume based on the total of the first resin composition and the second resin composition.

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

Comparative example 4

The first resin layer 12 was formed on the copper foil 11 in the same manner as in example 1, except that silica (product name: K180SQ-C1, average particle diameter 0.18 μm, manufactured by Admatechs Co., ltd.) as the inorganic filler (B1) was blended (mixed) into the first resin composition, and the thickness of the first resin layer 12 was set to 2.5. Mu.m. At this time, the content of silica as the inorganic filler (B1) (inorganic filler (B1)/first resin composition×100) was 25% by volume with respect to the first resin composition.

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

(evaluation of Properties)

The characteristics of each example and each comparative example were measured by the following methods.

(evaluation of conformal laser processability)

The copper foil-clad laminate (HL 832NS (trade name), T/T0.2 mmt, mitsubishi gas chemical Co., ltd.) having an inner layer circuit formed thereon was etched (inner layer roughening treatment, CZ-8101 (trade name, MEC Co., ltd.) at about 0.5 μm to 1 μm on both sides, and the resin-layer-attached copper foil 10 obtained in each example and each comparative example was placed with the second resin layer 13 on both sides, and was subjected to a pressure of 30kgf/cm ² Lamination molding (thermosetting) was performed at 220℃for 90 minutes to obtain a four-layer substrate.

A circular opening having a diameter of about 15 μm was formed in the copper foil on the surface of each obtained four-layer substrate by the subtractive method, and irradiated with laser light, thereby forming a non-through hole having a diameter of about 15 μm. Next, as a step of removing the offset residue, each of the four layers of the obtained substrates was set on a plating jig (racking), and immersed and rocked in a swelling bath, an etching bath, and a neutralization bath. The medicinal liquid is prepared by APPDES (available from Shangcun industries, inc.). The swelling liquid is APPDES MDS-37, the etching liquid is APPDES MDE-40 and ELC-SH mixed liquid, and the neutralization liquid is APPDES MDN-62. The temperature of the etching bath was set at 80℃and the immersion was carried out for 10 minutes.

Next, each of the four layers of the obtained substrates was set up on a plating jig, and electroless copper plating was performed on an apparatus of ALMEX PE company limited capable of immersing and shaking in an electroless copper plating bath. The chemical solution was a mixture of THRU-CUP PEA and formaldehyde, which were manufactured by Shangcun industries, inc. The electroless copper plating thickness was set to 0.4 μm. Next, hole filling plating was performed using an immersion apparatus of ALMEX PE Co., ltd.) to a thickness of 15. Mu.m.

For each of the four plated substrates, in order to confirm the aperture of the non-through hole, first, the non-through hole was cut out by a section grinder of the company of tostel, inc. The polishing was performed by rough cutting using #1000 polishing paper, cutting a cross section of the center of the non-through hole with #2400 polishing paper, and finally polishing. The observation after cutting the cross section was performed by adjusting the magnification to 50 times or 100 times using a GX51 of Olympus Co., ltd. For each sample prepared, the top diameter and bottom diameter were measured, and the top-bottom ratio (bottom diameter/top diameter) was calculated. The results obtained are shown in Table 1. In table 1, the value is "good" when the bottom diameter/top diameter is 0.7 or more and 1 or less, and the value is "x" when the value is less than 0.7 or less. In addition, when the bottom diameter/top diameter is evaluated as "X", it is considered that the removal property of the cement is poor, and the bottom diameter is decreased due to the residual cement; and the balance between the opening diameter and the volume ratio of the inorganic filler occupying the first resin layer 12 and the second resin layer 13 is poor, and the working shape is poor.

(evaluation of direct laser processability)

The resin layer-attached copper foil 10 obtained in each example and each comparative example was laminated on both sides of the copper clad laminate in the same manner as in the evaluation of the coform laser processability, to obtain a four-layer substrate. The four-layer substrates obtained were each subjected to blackening treatment of a surface copper foil, and irradiated with laser light to form through holes having a diameter of about 40. Mu.m. Then, the desmear, electroless copper plating, and pore-filling plating were performed in the same manner as the evaluation of the conformal laser processability. In addition, for each of the four-layer substrates plated, a cross section of the through hole was cut out and the top diameter and bottom diameter thereof were measured as in the evaluation of the coform laser processability, and the top-bottom ratio (bottom diameter/top diameter) was calculated. The results obtained are shown in Table 1. The "good" and "X" criteria for evaluation are the same as those for evaluation of the coform laser processability.

(evaluation of strength of laminate film)

The resin layer-attached copper foil 10 obtained in each example and each comparative example was laminated by repeating etching and lamination of the surface layer copper foil after lamination pressing (at 220 ℃ for 90 minutes), thereby producing a resin sheet having a layer containing a resin composition with a thickness of 30 μm, and a part thereof was cut out, to obtain a test piece. The test piece was placed on a glass slide, and 10 points were loaded with a micro Vickers hardness tester (trade name: HMV-G, manufactured by Shimadzu corporation, load 2kgf, holding time 15 seconds). Thus, when a cross-shaped crack (crack) occurs, the length of the crack and the length of the width of the crack are measured, respectively. If no crack is observed, the crack length is set to 0. The average value of the lengths of the cracks was calculated from the lengths of both the lengths and the widths of the cracks, and was rated as "excellent" when the average value was 400 μm or less, and rated as "good" when the average value was 401 μm or more and 1000 μm or less, and rated as "X" when the average value was otherwise. The results obtained are shown in Table 1.

TABLE 1

As shown in table 1, according to examples 1 to 5, good results were obtained for the conformal laser processability, the direct laser processability, and the strength of the laminated film. In contrast, in comparative examples 1 and 2 in which the content of the inorganic filler (B2) in the second resin composition was less than 15% by volume, the residue was left, and good results were not obtained in terms of the conformal laser processability and the direct laser processing. As for 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 were not obtained. In comparative example 4 in which the content of the inorganic filler (B1) in the first resin composition was more than 15% by volume, overhanging occurred in the direct laser processing, and good results were not obtained in both the conformal laser processing and the top-bottom ratio in the direct laser processing.

That is, it can be seen that: if no inorganic filler is added to the first resin composition or if the inorganic filler (B1) is added, the content of the inorganic filler (B1) is 15% by volume or less, and if the inorganic filler (B2) is added to the second resin composition, the content of the inorganic filler (B2) is 15% by volume or more and 35% by volume or less, cracking is suppressed, and a good processing shape can be obtained both in conformal laser processing and in direct laser processing.

[ symbolic description ]

10: copper foil with resin layer

11: copper foil

12: a first resin layer

13: second resin layer

20: laminate body

21: conductor layer

22: substrate board

23: insulating layer

100: multilayer coreless substrate

111: a first insulating layer

112: second insulating layer

113: first conductor layer

114: second conductor layer

Claims (8)

1. A resin layer-attached copper foil comprising: a copper foil, a first resin layer laminated on the copper foil, and a second resin layer laminated on the first resin layer; it is characterized in that

The first resin layer is composed of a first resin composition containing a thermosetting resin (A1) and no inorganic filler, or is composed of a first resin composition containing a thermosetting resin (A1) and an inorganic filler (B1), and the content of the inorganic filler (B1) is 15% by volume or less;

the second resin layer is composed of a second resin composition containing a thermosetting resin (A2) and an inorganic filler (B2), and the content of the inorganic filler (B2) is 15 to 35% by volume.

2. The resin layer-attached copper foil according to claim 1, wherein a total content of the inorganic filler (B1) and the inorganic filler (B2) is 2.5% by volume or more and 33.3% by volume or less relative to a total of the first resin composition and the second resin composition.

3. The resin layer-attached copper foil according to claim 1, wherein the thickness of the first resin layer is 1 μm or more and 5 μm or less.

4. The resin layer-attached copper foil according to claim 1, wherein the thickness of the second resin layer is 1 μm or more and 10 μm or less.

5. The resin layer-attached copper foil according to claim 1, wherein the thermosetting resin (A1) contains at least one selected from the group consisting of polyimide resins, liquid crystal polyesters, epoxy compounds, cyanate ester compounds, maleimide compounds, phenol compounds, polyphenylene ether compounds, benzoxazine compounds, organic group-modified silicone compounds, and compounds having polymerizable unsaturated groups.

6. The resin layer-attached copper foil according to claim 1, wherein the thermosetting resin (A2) contains at least one selected from the group consisting 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.

7. The resin layer-attached copper foil according to claim 1, wherein the inorganic filler (B1) and the inorganic filler (B2) contain at least one selected from the group consisting of magnesium hydroxide, magnesium oxide, silicon dioxide, molybdenum compounds, aluminum oxide, aluminum nitride, glass, talc, titanium compounds, and zirconium oxide.

8. A laminate comprising a conductor layer and a build-up layer formed using the resin layer-attached copper foil according to claim 1.

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