JP2011051247A - Metal foil with thermosetting resin composition layer, metal clad laminated plate, and printed wiring board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide metal foil with a thermosetting resin composition layer enabling fine wiring and enabling the formation of a fine surface having surface roughness (Rz) below 3 μm in the case of roughening a resin surface, and to provide a metal clad laminated plate and a printed wiring board. <P>SOLUTION: The metal foil with the thermosetting resin composition layer includes a 1.0 to 5.0 μm thick layer of the thermosetting resin composition containing an epoxy resin (A), at least one kind (B) selected from a polyvinyl acetal resin and a carboxylic acid-modified polyvinyl acetal resin, an epoxy resin curing agent (C), a curing accelerator (D), and a nano particle filler (E) having a central particle diameter of 10 to 50 nm and the maximum particle diameter of ≤100 nm on the metal foil having a ten-point average roughness (Rz) of ≤2.0 μm. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a metal foil with a thermosetting resin composition layer, a metal-clad laminate using the same, and a printed wiring board.

  In recent years, along with the downsizing, weight reduction, and multifunctionalization of electronic devices, there is a tendency to increase the mounting density of electronic components and the like on a printed wiring board, and the fine wiring of multilayer printed wiring boards is rapidly progressing. As one effective method for forming a multilayer printed wiring board having a high mounting density such as electronic parts, a semi-additive construction method is used. In this method, the surface of the resin plate is roughened to give a Pd catalyst for performing electroless copper plating, and after the electroless copper plating to form a circuit underlayer, a pattern electroplating resist is formed to form a pattern electroplating resist. After the circuit is formed by plating, the method is to remove the circuit base layer existing in portions other than the resist and the circuit, and enables finer wiring formation as compared with the conventional subtractive method. In the above method, the resin plate is a cured product of a resin including a fiber substrate such as a glass cloth, which is usually called a laminated plate. There is also an example in which a resin layer is provided between the resin plate and the circuit base layer (see, for example, Patent Document 1). When removing the circuit underlayer by etching, it was possible to remove the remaining part of the plating metal and the Pd catalyst that had entered the concave portion of the resin plate at the bonding interface between the circuit underlayer and the resin plate. It is necessary from the viewpoint of insulation resistance. Therefore, in the roughening step, if the surface roughness (Rz) of the resin plate becomes too large to 3 μm or more, it is necessary to etch the circuit portion in order to cleanly remove the metal and Pd catalyst in the resin recess. Etching must be performed for more than a certain amount of time, and if the etching is performed more than necessary, the circuit underlayer part is excessively etched.

JP 2003-158364 A

  Accordingly, an object of the present invention is to provide a material for a multilayer printed wiring board that can form a fine wiring and can form a fine surface having a surface roughness (Rz) of less than 3 μm when the resin surface is roughened. Yes, more specifically, to provide a metal foil with a thermosetting resin composition layer, a metal-clad laminate, and a printed wiring board.

The present invention relates to the following. That is,
(1) At least one selected from (A) an epoxy resin, (B) a polyvinyl acetal resin, and a carboxylic acid-modified polyvinyl acetal resin on the surface of a metal foil having a ten-point average roughness (Rz) of 2.0 μm or less; C) a layer of a thermosetting resin composition containing an epoxy resin curing agent, (D) a curing accelerator, and (E) a nanoparticle filler having a center particle size of 10 nm to 50 nm and a maximum particle size of 100 nm or less. The present invention relates to a metal foil with a thermosetting resin composition layer, characterized by having a thickness of 5.0 μm.
The present invention also provides:
(2) The present invention relates to a metal-clad laminate obtained by stacking and heating and pressing the metal foil with a thermosetting resin composition layer according to (1) above and at least one prepreg.
Furthermore, the present invention provides
(3) The present invention relates to a printed wiring board obtained by performing wiring processing on the metal foil of the metal-clad laminate according to (2).
The thermosetting resin composition layer of the metal foil with a thermosetting resin composition layer in the present invention is in a B-stage (semi-cured) state. The resin in the metal-clad laminate in the present invention is in the C stage (cured) state.

  According to the present invention, a metal foil with a thermosetting resin composition layer and a metal-clad laminate capable of forming a fine surface having a surface roughness (Rz) of less than 3 μm when a fine wiring can be formed and the resin surface is roughened. Boards and printed wiring boards can be provided.

The thermosetting resin composition used for the metal foil adhesion aid used in the present invention is (A) an epoxy resin, (B) at least one polyvinyl acetal resin selected from a polyvinyl acetal resin, a carboxylic acid-modified polyvinyl acetal resin, (C) An epoxy resin curing agent, (D) a curing accelerator, and (E) a nanoparticle filler having a center particle size of 10 nm to 50 nm and a maximum particle size of 100 nm or less, and using the resin composition as an adhesion auxiliary layer Since the metal foil used can be provided with an ultra-thin semi-additive adhesive layer between the copper foil and the prepreg by stacking at least one prepreg and heating and pressurizing, low thermal expansion of the prepreg, A metal-clad laminate having both high elastic modulus and fine wiring by the semi-additive method of adhesive layer can be produced.
The surface of the metal foil on which the adhesion auxiliary layer (adhesion layer) made of the thermosetting resin composition is formed has a ten-point average roughness (Rz) of 2.0 μm or less, preferably 1.5 μm or less. 1.2 μm or less is more preferable. Moreover, the thickness of an adhesion auxiliary layer (adhesion layer) is 1 to 5 μm.

  Examples of the epoxy resin of component (A) include epoxy resins and polyfunctional epoxy compounds that are compounds having an epoxy group, such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, and biphenyl type epoxy resin. , Phenol novolac type epoxy resin, cresol novolak type epoxy resin, bisphenol A novolak type epoxy resin, naphthalene skeleton containing epoxy resin, aralkylene skeleton containing epoxy resin, phenol biphenyl aralkyl type epoxy resin, phenol salicylaldehyde novolak type epoxy resin, lower alkyl group Substituted phenol salicylaldehyde novolak type epoxy resin, dicyclopentadiene skeleton-containing epoxy resin, polyfunctional glycidylamine type epoxy resin and It can be exemplified functional alicyclic epoxy resins and the like, can be used alone or in combination of two or more thereof.

  Commercially available products include NC-3000H and NC-3000S manufactured by Nippon Kayaku Co., Ltd. as biphenylaralkyl type epoxy resins, ZX-1548 manufactured by Tohto Kasei Co., Ltd. as a phosphorus-containing epoxy resin, and cresol novolac type epoxy resins Examples of EPICLON N-660 manufactured by Dainippon Ink and EP-828 manufactured by Japan Epoxy Resin Co.

  Among these, it is desirable to include a novolac type epoxy resin or a novolac type epoxy resin. The novolac type epoxy resin in the present invention is preferably a novolac type epoxy resin having a biphenyl structure. The novolak-type epoxy resin having a biphenyl structure refers to a novolak-type epoxy resin containing an aromatic ring of a biphenyl derivative in the molecule, for example, the formula (1):

（式中、ｐは、１〜５を示す）で示されるエポキシ樹脂が挙げられる。

(Wherein, p represents 1 to 5).

  Commercially available products include NC-3000 (epoxy resin of formula (1) where p is 1.7) and NC-3000-H (epoxy resin of formula (1) where p is 2.8) manufactured by Nippon Kayaku Co., Ltd. ).

  The (A) component epoxy resin can also be used in combination with a rubber-modified epoxy resin. The rubber-modified epoxy resin can be used without particular limitation as long as it is a product marketed for adhesives or paints.

  Examples of commercially available products include EPICLON TSR-960 manufactured by Dainippon Ink Co., Ltd., EPOTOOHTO YR-102 manufactured by Tohto Kasei Co., Ltd., and Sumiepoxy ESC-500 manufactured by Sumitomo Chemical Co., Ltd.

The content of the rubber-modified epoxy resin used in combination is preferably 10 to 80% by mass of the total epoxy resin. When a rubber-modified epoxy resin is blended, the elongation at the time of curing is increased, and the adhesion to the copper foil surface is improved. However, if it is less than 10% by mass, the effect cannot be sufficiently exhibited, and if it exceeds 80% by mass, the heat resistance is poor. The range of 30-70 mass% is more preferable.
Two or more rubber-modified epoxy resins may be used, but the total amount is preferably within the above-mentioned range.

The component (B) is at least one selected from polyvinyl acetal resins and carboxylic acid-modified polyvinyl acetal resins.
Although the kind of polyvinyl acetal resin, the amount of hydroxyl groups, and the amount of acetyl groups are not particularly limited, those having a polymerization degree of 1000 to 2500 are preferred. Within this range, solder heat resistance can be secured, and the viscosity and handling properties of the varnish are good. Here, the number average degree of polymerization of the polyvinyl acetal resin can be determined, for example, from the number average molecular weight of polyvinyl acetate as a raw material (measured using a standard polystyrene calibration curve by gel permeation chromatography). Moreover, a carboxylic acid modified product etc. can also be used.

  Polyvinyl acetal resin is, for example, trade names manufactured by Sekisui Chemical Co., Ltd., ESREC BX-1, BX-2, BX-5, BX-55, BX-7, BH-3, BH-S, KS-3Z, KS-5, KS-5Z, KS-8, KS-23Z, trade names made by Denki Kagaku Kogyo Co., Ltd., electrified butyral 4000-2, 5000A, 6000C, 6000EP, and the like can be used. These resins can be used alone or in admixture of two or more.

  (A) It is preferable that (B) component is 0.5-30 mass parts with respect to 100 mass parts of (A) component. If the component (B) is less than 0.5 parts by mass, the peel strength and the peel strength of the electroless plating after chemical roughening are low, and if it exceeds 30 parts by mass, the solder heat resistance and the insulation reliability are reduced. Absent. Particularly when 1 part by mass or more of crosslinked rubber particles is used in combination, the peel strength of the copper foil or the electroless plating after chemical roughening is improved when the blending amount of the polyvinyl acetal resin is 1 part by mass or more. And more preferred.

  The epoxy resin curing agent of component (C) is not particularly limited as long as it is a compound having a plurality of phenolic hydroxyl groups in the molecule, but a compound having two or more hydroxyl groups in one phenyl group such as hydroquinone, Examples thereof include compounds containing a plurality of phenol rings or cresol rings in one molecule such as phenol resin and cresol resin.

Examples of commercially available products include Phenolite LA-1356 and LA-3018 manufactured by Dainippon Ink & Chemicals, Inc. as aminotriazine-modified novolak resins, and MEH-7851 manufactured by Meiwa Kasei Co., Ltd. as biphenyl novolak resins.
Among these, a novolak type phenolic resin is preferable as the component (C), and a triazine ring-containing novolak type phenolic resin has a peeling strength of copper foil and a peeling strength of electroless plating after chemical roughening. It is improved and more preferable.

  In the present invention, the triazine ring-containing novolak type phenol resin means a novolak type phenol resin containing a triazine ring in the main chain of the novolak type phenol resin, and may be a cresol novolak type phenol resin containing a triazine ring. The nitrogen content is preferably 10 to 25% by mass, more preferably 12 to 19% by mass in the triazine ring-containing novolac type phenol resin. When the nitrogen content in the molecule is within this range, the dielectric loss does not become too large, and when the adhesive is used as a varnish, the solubility in the solvent is appropriate and the remaining amount of undissolved material can be suppressed. . As the triazine ring-containing novolac type phenol resin, one having a number average molecular weight of 500 to 600 can be used. These may be used alone or in combination of two or more.

  The triazine ring-containing novolak type phenol resin can be obtained by reacting phenol, an aldehyde, and a triazine ring-containing compound under conditions of pH 5-9. When cresol is used instead of phenol, a triazine ring-containing cresol novolac type phenol resin is obtained. As the cresol, any of o-, m-, and p-cresol can be used. As the triazine ring-containing compound, melamine, guanamine and derivatives thereof, cyanuric acid and derivatives thereof, and the like can be used.

  As a commercially available product, Dainippon Ink & Chemicals, Inc., a triazine ring-containing cresol novolac type phenol resin phenolite LA-3018 (nitrogen content 18% by mass) can be mentioned.

(D) Any curing accelerator may be used as the component, but it is preferable to blend various imidazoles and BF ₃ amine complexes which are latent thermosetting agents. 2-phenylimidazole, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2 from the viewpoints of storage stability of the thermosetting resin composition (adhesive), handleability in B-stage and solder heat resistance -Phenylimidazolium trimellitate is preferred.

  (D) The compounding quantity of a component has the preferable range of 0.1-5 mass parts with respect to 100 mass parts of (A) epoxy resins in a thermosetting resin composition, and the range of 0.3-1 mass parts. Is more preferable. Within these ranges, sufficient solder heat resistance, good storage stability, and good handleability when using the B stage can be obtained.

  The nanoparticle filler of component (E) is not particularly limited, and examples thereof include silica, fused silica, talc, alumina, aluminum hydroxide, barium sulfate, calcium hydroxide, aerosil, and calcium carbonate. The nanoparticle filler may contain those treated with various coupling agents such as a silane coupling agent for the purpose of enhancing dispersibility. These may be used alone or in combination of two or more. Silica is preferred from the viewpoint of dielectric properties and low thermal expansion.

The nanoparticle filler of component (E) has a center particle size of 10 nm to 50 nm and a maximum particle size of 100 nm or less. When the center particle size and the maximum particle size are larger than this, the withstand voltage of the laminate is reduced and roughened during desmear treatment. There is a problem that the conversion shape becomes large.
The center particle size defined in the present invention is the center of the cumulative average diameter measured using a particle size distribution measuring device (in the present invention, manufactured by Nikkiso Co., Ltd., using an ultrasensitive nano particle size distribution measuring device UPA-UT151). Let the diameter (D ₅₀ ) and the maximum particle size (D ₁₀₀ ) be the center particle size and the maximum particle size, respectively.

  The compounding amount of the nanoparticle filler that is the component (E) is preferably in the range of 5 to 35% by volume, more preferably 10 to 30 volumes, in the total volume of the components (A) to (E). %. When the blending amount is within this range, the thermal expansion coefficient and the dielectric loss are not increased, and a flow sufficient for forming the insulating layer on the inner layer circuit can be obtained. In order to disperse the nanoparticle filler in the thermosetting resin composition, a known kneading method such as a kneader, a ball mill, a bead mill, or a three roll can be used.

In order to improve flame retardancy, the thermosetting resin composition may further contain (F) a phenolic hydroxyl group-containing phosphorus compound.
(F) The phenolic hydroxyl group-containing phosphorus compound is a phosphorus compound containing a phenolic hydroxyl group as represented by the following formula (2). These may be used alone or in combination of two or more.

（式（２）中、ｎが１の場合、Ｒ_４は、水素原子、直鎖状のアルキル基、分枝状のアルキル基、シクロアルキル基、アリール基又はアラルキル基であり、ｎが２の場合、それぞれのＲ_４は独立して、水素原子、直鎖状のアルキル基、分枝状のアルキル基、シクロアルキル基、アリール基又はアラルキル基であるか、２つのＲ_４は、それぞれが結合している炭素原子と一緒になって、非置換又はアルキル基若しくはシクロアルキル基で置換されているベンゼン環を形成し、ｘは、２以上の自然数である）

(In the formula (2), when n is 1, R ₄ is a hydrogen atom, a linear alkyl group, a branched alkyl group, a cycloalkyl group, an aryl group or an aralkyl group; Each R ₄ independently represents a hydrogen atom, a linear alkyl group, a branched alkyl group, a cycloalkyl group, an aryl group or an aralkyl group, or two R _{4 s} are bonded to each other. Together with the carbon atom in question, forms a benzene ring which is unsubstituted or substituted with an alkyl or cycloalkyl group, x being a natural number of 2 or more)

In the formula (2), when R ₄ is a linear or branched alkyl group, an alkyl group having 1 to 6 carbon atoms is preferable, and in the case of a cycloalkyl group, a cycloalkyl group having 6 to 8 carbon atoms is preferable. In the case of an aryl group, a phenyl group is preferable, and in the case of an aralkyl group, an aralkyl group having 7 to 10 carbon atoms is preferable. x is preferably 2. Also, in formula (2), n is 2, and two R ₄ are together with the carbon atom to which each is bonded, and two R ₄ are together with the carbon atom to which each is bonded. To form a benzene ring which is unsubstituted or substituted with an alkyl group or a cycloalkyl group, it is unsubstituted or substituted with an alkyl group having 1 to 4 carbon atoms or a cycloalkyl group having 6 to 8 carbon atoms. The benzene ring is preferred.

  Specifically, the phosphorus compound shown by Formula (3) or Formula (4) is mentioned.

（式中、Ｒ_５は、水素原子、メチル、エチル、ｎ−プロピル、イソプロピル、ｎ−ブチル、イソブチル、ｓｅｃ−ブチル、ｔｅｒｔ−ブチル基、シクロヘキシル基を表す）

(Wherein R ₅ represents a hydrogen atom, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl group, or cyclohexyl group)

In particular, 10- (2,5-dihydroxyphenyl) -9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and derivatives thereof are preferred.
As a commercial item, Sanko Co., Ltd. HCA-HQ is mentioned.

  In the case of imparting flame retardancy, the compounding amount of the (F) phenolic hydroxyl group-containing phosphorus compound in the thermosetting resin composition is preferably in terms of phosphorus atoms in the total mass of the components (A) to (E). Is in the range of 1.5 to 3.5 mass%, more preferably in the range of 1.8 to 2.5 mass%. When the blending amount is within this range, the flame retardancy is good, the insulation reliability is excellent, and the Tg of the cured coating film is not too low.

The thermosetting resin composition in the present invention may further contain (G) a thermoplastic resin in order to improve flexibility.
Examples of the thermoplastic resin (G) in the present invention include fluororesin, polyphenylene ether, modified polyphenylene ether, polyphenylene sulfide, polycarbonate, polyetherimide, polyetheretherketone, polyarylate, polyamide, polyamideimide, and polybutadiene. However, it is not limited to these. One type of thermoplastic resin may be used alone, or two or more types may be mixed and used.

  Among thermoplastic resins, blending polyphenylene ether and modified polyphenylene ether is useful because it improves the dielectric properties of the cured product. Examples of polyphenylene ether and modified polyphenylene ether include poly (2,6-dimethyl-1,4-phenylene) ether, poly (2,6-dimethyl-1,4-phenylene) ether and polystyrene alloyed polymer, poly Alloyed polymer of (2,6-dimethyl-1,4-phenylene) ether and styrene-butadiene copolymer, Alloyed polymer of poly (2,6-dimethyl-1,4-phenylene) ether and styrene-maleic anhydride copolymer Alloyed polymer of poly (2,6-dimethyl-1,4-phenylene) ether and polyamide, alloyed polymer of poly (2,6-dimethyl-1,4-phenylene) ether and styrene-butadiene-acrylonitrile copolymer, etc. Is mentioned. In addition, in order to impart reactivity and polymerizability to polyphenylene ether, functional groups such as amino groups, epoxy groups, carboxyl groups, styryl groups, and methacryl groups are introduced at the ends of polymer chains, or amino groups are introduced into the side chains of polymer chains. In addition, a functional group such as an epoxy group, a carboxyl group, a styryl group, or a methacryl group may be introduced.

Among thermoplastic resins, polyamideimide resin is useful because it has excellent heat resistance and moisture resistance, and also has good adhesion to metal. Among the raw materials for polyamideimide, trimellitic anhydride, trimellitic anhydride monochloride, as the acid component, and metaphenylenediamine, paraphenylenediamine, 4,4'-diaminodiphenyl ether, 4,4'- as the amine component Examples include, but are not limited to, diaminodiphenylmethane, bis [4- (aminophenoxy) phenyl] sulfone, 2,2′-bis [4- (4-aminophenoxy) phenyl] propane, and the like. In order to improve drying property, it may be modified with siloxane. In this case, siloxane diamine is used as the amino component. In consideration of film processability, it is preferable to use a molecular weight of 50,000 or more.
You may mix | blend additives, such as a pigment, a leveling agent, an antifoamer, and an ion trap agent, with a thermosetting resin composition as needed.

Each component of the thermosetting resin composition described above is dissolved or dispersed in a solvent to form a varnish, which is applied to one side of a metal foil (for example, copper foil) and semi-cured, thereby thermosetting. Metal foil with adhesive resin composition layer (copper foil with adhesive layer) is completed.
Solvents include ketones such as acetone, methyl ethyl ketone, cyclohexanone, aromatic hydrocarbons such as benzene, xylene, and toluene, alcohols such as ethylene glycol monoethyl ether, esters such as ethyl ethoxypropionate, N, N -Amides such as dimethylformamide and N, N-dimethylacetamide. These solvents may be used alone or in combination of two or more. The usage-amount of the solvent with respect to a thermosetting resin composition (adhesion adjuvant) is not specifically limited, It can be made into the quantity conventionally used.

  When a thermosetting resin composition (also referred to as an adhesion aid or adhesive) is used as a varnish and applied to a copper foil with a comma coater or gravure coater, the total solid content of the thermosetting resin composition (adhesion aid) The amount of the solvent used is preferably adjusted so as to be 10 to 30% by mass, but the amount can also be adjusted according to the equipment for film formation.

  The thickness of the resin layer at this time is 1.0 to 5.0 μm. If the thickness is less than 1.0 μm, the adhesive layer is lost during the desmear treatment, and high adhesive strength with the plated copper may not be ensured during the semi-additive method. Moreover, when it exceeds 5.0 micrometers, there exists a possibility that the characteristic of the prepreg used at the time of shaping | molding may worsen. For example, there is a possibility that the elastic modulus as a substrate after heating and pressurization, Tg, and the like are significantly reduced. In order to sufficiently exhibit the characteristics of the prepreg, the resin layer is preferably in the range of 2.0 to 4.0 μm.

  Although it does not specifically limit as metal foil used for this invention, For example, copper foil, nickel foil, aluminum foil etc. can be used, and copper foil is normally used. The type of copper foil is not particularly limited, such as electrolytic copper foil or rolled copper foil. Further, the thickness of the metal foil to be used is not particularly limited. A metal foil having a thickness of 105 μm or less, which is generally used for a printed wiring board, may be used, and a peelable type metal foil may be used. Instead of the peelable type, an etchable type metal foil having an aluminum carrier or a nickel carrier can also be used. The surface roughness of the surface in contact with the adhesive layer of the metal foil to be used is not subjected to roughening treatment from the viewpoint of fine wiring formation, and the ten-point average roughness (Rz) is 2.0 μm or less. If the roughness becomes rougher than this, it becomes difficult to form a fine roughened shape by desmear, so fine wiring cannot be formed. The surface roughness is defined by JIS B601, and the ten-point average roughness (Rz) is based on it.

  Examples of commercially available products include F0-WS foil manufactured by Furukawa Circuit Foil Co., Ltd. for electrolytic copper foil, HLPB foil manufactured by Nikko Materials Co., Ltd., and ZSPC foil manufactured by Microhardware Co., Ltd. for rolled copper foil.

The metal foil used in the present invention is preferably subjected to a rust prevention treatment performed on an insulating layer adhesion surface of a general metal foil. The rust prevention treatment can be performed using any of nickel, tin, zinc, chromium, molybdenum, cobalt, or an alloy thereof, but is preferably performed by at least one selected from zinc and chromium. The amount of the rust-proofing metal varies depending on the type of metal, but is preferably 10 to 2000 μg / dm ^{2 in} total. If the rust prevention treatment is too thick above the upper limit, it may cause etching inhibition and a decrease in electrical characteristics.

Furthermore, if a chromate treatment layer is formed on the rust prevention treatment, it is useful because a reduction in peel strength with the resin can be suppressed. Specifically, it is performed using an aqueous solution containing hexavalent chromium ions. The chromate treatment can be performed by a simple immersion treatment, but is preferably performed by a cathode treatment. Sodium dichromate 0.1-50 g / L, pH 1-13, bath temperature 0-60 ° C., current density 0.1-5 A / dm ² , electrolysis time 0.1-100 seconds are preferable. It can also be performed using chromic acid or potassium dichromate instead of sodium dichromate.

  In the present invention, it is preferable that a silane coupling agent is further adsorbed on the outermost layer of the copper foil. Examples of silane coupling agents include 3-glycidoxypropyltrimethoxysilane, epoxy-functional silanes such as 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-aminopropyltrimethoxysilane, and N-2. Amino-functional silanes such as-(aminoethyl) 3-aminopropyltrimethoxysilane, N-2- (aminoethyl) 3-aminopropylmethyldimethoxysilane, vinyltrimethoxysilane, vinylphenyltrimethoxysilane, vinyltris (2- Olefin functional silane such as methoxyethoxy) silane, acrylic functional silane such as 3-acryloxypropyltrimethoxysilane, methacryl functional silane such as 3-methacryloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane Such as mercapto functional silane is used. Considering compatibility with an adhesion aid to be applied later, it is desirable to have an epoxy group or an amino group in the molecule. These may be used alone or in combination.

As a method for producing a metal-clad laminate using a metal foil with a thermosetting resin composition layer (copper foil with an adhesive layer) as described above, at least one metal foil with a thermosetting resin composition layer and at least one sheet A prepreg can be laminated and integrated by a conventionally known method, and heated and pressed to obtain a laminated plate.
The conditions for heating and pressing differ depending on the prepreg resin. For example, when a glass cloth base epoxy resin prepreg is used, the temperature is 150 to 250 ° C. and the pressure is 0.5 to 8.0 MPa.

  Thereafter, by a known method, wiring processing is performed on the metal foil surface of the metal-clad laminate to obtain a printed wiring board. In the wiring processing, either an etching method or a semi-additive method may be performed.

Example 1
The thermosetting resin composition A shown below was produced.
(Preparation of thermosetting resin composition A)
-(A) component: Novolak type epoxy resin having a biphenyl structure, NC3000S-H (manufactured by Nippon Kayaku Co., Ltd.); 35 parts by mass-(B) component: carboxylic acid-modified polyvinyl acetal resin, KS-23Z (Sekisui Chemical Co., Ltd.) 5 parts by mass and (C) component: triazine ring-containing cresol novolac type phenol resin, phenolite LA-3018 (nitrogen content 18% by mass, hydroxyl group equivalent 151, manufactured by Dainippon Ink & Chemicals, Inc.); 10 parts by mass / component (D): imidazole derivative compound, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2PZ-CNS (manufactured by Shikoku Kasei Kogyo Co., Ltd.); 0.3 parts by mass / component (E): nanosilica 1 (Average particle size 15 nm, maximum particle size 40 nm, spherical, methyl ethyl ketone slurry, 30% by mass); 5 Parts by weight solvent, methyl ethyl ketone; qs

(Metal foil with thermosetting resin composition layer; preparation of copper foil with adhesive layer)
The above thermosetting resin composition A is applied to the adhesive surface of an electrolytic copper foil (product name F0-WS12: manufactured by Furukawa Circuit Foil, Rz = 1.2 μm) having a width of 540 mm and a thickness of 12 μm. Produced. After coating, drying was performed at 160 ° C. for about 10 minutes so that the residual solvent was 5% by mass or less. The thickness of the applied thermosetting resin composition A (adhesive thickness) was 3.0 μm.

  Hitachi Chemical Co., Ltd. glass cloth base material high Tg epoxy resin prepreg GEA-679FG (thickness 0.1 mm) 4 and the adhesive layer so that the surface where the thermosetting resin composition A was applied to the top and bottom thereof is in contact with the prepreg The attached copper foil A was laminated and press molded at 180 ° C. and 3.0 MPa for 1 hour to produce a copper-clad laminate.

(Example 2)
In Example 1, except that nanosilica 1 was changed to nanosilica 2 (average particle size 30 nm, maximum particle size 50 nm, spherical, methyl ethyl ketone slurry, 30% by mass), a copper clad laminate was prepared in the same manner as in Example 1. Produced.

(Comparative Example 1)
A copper clad laminate was prepared in the same manner as in Example 1 except that nanosilica 1 was changed to nanosilica 3 (average particle size 100 nm, maximum particle size 500 nm, spherical, methyl ethyl ketone slurry, 30% by mass) in Example 1. Produced.

(Comparative Example 2)
In Example 1, a copper clad laminate was prepared in the same manner as in Example 1 except that the thermosetting resin composition A was applied to a thickness (adhesive thickness) of 10 μm.

(Comparative Example 3)
A copper-clad laminate was prepared in the same manner as in Example 1 except that F3WS-12 foil (Furukawa Circuit Foil, Inc .: Rz = 3.5 μm) was used instead of F0-WS12 foil.

(Comparative Example 4)
In Example 1, a copper-clad laminate was produced in the same manner as in Example 1 except that the thermosetting resin composition A was not applied to the F0-WS12 foil.

(Evaluation of fine wiring formation)
The double-sided copper-clad laminates obtained in Examples 1 and 2 and Comparative Examples 1 to 4 were entirely etched, and using the semi-additive method shown below, the minimum circuit conductor width / interval between adjacent circuit conductors (L / S ) = 20/20 μm A circuit pattern was formed.

  As a roughening treatment for the substrate etched on the entire surface, a permanganic acid roughening solution (Shipley) heated to 80 ° C for 5 minutes in a solvent swelling solution (MLB conditioner 211: trade name, manufactured by Shipley Co., Ltd.) heated to 70 ° C. Immerse in a hydroxylamine sulfate neutralizing solution (manufactured by Shipley Co., Ltd., MLB Neutralizer 216-2: trade name) for 10 minutes in MLB Promoter 213 (trade name) manufactured by Co., Ltd.

  Next, the substrate subjected to the roughening treatment is then immersed in a conditioner (made by Hitachi Chemical Co., Ltd., using CLC-601 (trade name)) at 60 ° C. for 5 minutes, washed with hot water at 60 ° C., Washed in water (normal temperature (25 ° C) water, the same shall apply hereinafter), electroless plating catalyst solution (made by Hitachi Chemical Co., Ltd., using HS-202B (trade name)) for 10 minutes at normal temperature, with normal temperature water It was washed with water and immersed in a palladium activation treatment solution (Hitachi Chemical Industry Co., Ltd., ADP-401 (trade name)) at room temperature for 5 minutes and washed in this order.

Next, it is immersed in an electroless copper plating solution (manufactured by Hitachi Chemical Co., Ltd., CUST201 (trade name)) at room temperature for 15 minutes, washed with water, dried at 80 ° C. for 10 minutes, and electroless plating thinned (no Electrolytic plating layer, 1 μm) was performed.
Next, RY-3325 (trade name, manufactured by Hitachi Chemical Co., Ltd.), which is a dry film photoresist, is laminated on the surface of the electroless plating layer, and ultraviolet rays are passed through a photomask that masks a place where electrolytic copper plating is performed. Was exposed and further developed to form a plating resist.
Next, using a copper sulfate bath, electrolytic copper plating was performed for about 20 μm under conditions of a liquid temperature of 25 ° C. and a current density of 1.0 A / dm ² to form a circuit. Further, after removing the plating resist, the thin electroless plating layer as the base copper was removed by hydrogen peroxide-based quick etching.

(Circuit formability)
Next, it was evaluated using a microscope and an ohmmeter whether the circuit pattern was reliably formed.
When L / S = 20μm / 20μm, the line width is within 10% of the target value, and the insulation resistance between the lines is 10 ¹⁰ Ω or more, good (◯), and the line width is 10% of the target value A case of exceeding or having an insulation resistance of less than 10 ¹⁰ Ω was regarded as defective (×).

(Measurement of plating peel)
Using part of the circuit pattern for fine wiring formation evaluation in Examples 1 and 2 and Comparative Examples 1 to 4, the conductor peeling strength of the evaluation sample was measured. For peeling, the vertical peeling strength was measured. Measurements were always made at 20 ° C. The measuring method was based on JIS-C-6482.

(Hygroscopic heat resistance test)
The moisture absorption heat test of the substrates for Examples 1 and 2 and Comparative Examples 1 to 4 was performed. The test of the substrate was performed by treating each sample for 2 hours under the conditions of 121 ° C, 100% humidity and 2 atmospheres, and then immersed in a solder bath at 288 ° C for 20 seconds to check whether the substrate was swollen or not. went. A saturation type PCT apparatus PC-242 manufactured by Hirayama Seisakusho was used for the test.

(Test results)
The test results are shown in Table 1. It turned out that the board | substrate produced in Example 1, 2 was excellent also in fine wiring formation, the plating peel was high, and was excellent in adhesiveness with plated copper. Moreover, the moisture absorption heat resistance of the substrate was also good. In the present invention, since the particle size of the nanoparticle filler is very small, the adhesive layer could maintain a smooth surface even with a very thin adhesive layer. For Comparative Examples 1 and 3, the adhesion was good. However, the desmear-treated surface has become rough due to the large particle size of the nanoparticle filler, and the formation of fine wiring has been difficult due to the large roughening of the copper foil. In Comparative Example 2, since the adhesive layer became thick, blistering occurred in the moisture absorption heat resistance test. Since Comparative Example 4 did not have an adhesive layer, adhesion with the plated copper was poor, line peeling occurred during circuit formation, and fine wiring formation was difficult.

  The metal foil with the thermosetting resin composition layer of the present invention (metal foil with an adhesion aid) is laminated with at least one prepreg and heated and pressed to form a very thin semi-additive between the copper foil and the prepreg. A copper-clad laminate provided with a compatible adhesive layer is obtained. For this reason, it is possible to produce a wiring board having both the low thermal expansion of the prepreg, the high elastic modulus and the fine wiring by the semi-additive method of the adhesive layer.

Claims (3)

  On the surface of a metal foil having a ten-point average roughness (Rz) of 2.0 μm or less, at least one selected from (A) an epoxy resin, (B) a polyvinyl acetal resin, and a carboxylic acid-modified polyvinyl acetal resin, (C) an epoxy A layer of a thermosetting resin composition containing a resin curing agent, (D) a curing accelerator, and (E) a nanoparticle filler having a center particle size of 10 nm to 50 nm and a maximum particle size of 100 nm or less is 1.0 to 5.0 μm. A metal foil with a thermosetting resin composition layer characterized by comprising   A metal-clad laminate obtained by stacking the metal foil with a thermosetting resin composition layer according to claim 1 and at least one prepreg and heating and pressing.   A printed wiring board obtained by performing wiring processing on the metal foil of the metal-clad laminate according to claim 2.