JP5482831B2 - Metal foil with adhesion aid, printed wiring board using the same, and method for producing the same - Google Patents

Description

  The present invention relates to a metal foil with an adhesion assistant, a printed wiring board using the same, and a method for manufacturing the same. Furthermore, the present invention relates to a multilayer wiring board, a semiconductor chip mounting substrate, and a semiconductor package substrate using a metal foil with an adhesion assistant.

  In recent years, there has been an increasing demand for smaller, lighter, and faster electronic devices, and the density of printed wiring boards has been increasing. In recent years, a method for manufacturing printed wiring boards using a semi-additive method using electroplating has attracted attention. ing. In this semi-additive method, for example, as described in Patent Document 1, after forming a hole to be IVH with a laser or the like on the surface of a resin on which a circuit is to be formed, unevenness of several μm is formed on the resin by chemical roughening or plasma treatment. Form, apply Pd catalyst, perform electroless plating of about 1μm, form pattern electroplating resist, form circuit by pattern electroplating, and then remove power supply layer existing in parts other than resist and circuit This is a technique that enables finer wiring formation than a subtractive method with large side etching. Further, there is a method of forming a circuit on a metal foil with resin by a semi-additive method. In recent years, in order to reduce the thickness of the metal foil, for example, a peelable type metal foil in which a metal foil having a thickness of 5 μm or less is formed on a supporting metal foil as described in Patent Document 2 is used. In this method, it is not necessary to perform electroless plating on the surface of the insulating resin layer, and a printed wiring board with higher reliability can be manufactured. In addition, for example, as disclosed in Patent Document 3, a copper layer having a thickness of about 1 μm is formed on one surface of a polyimide film using an electron beam evaporation apparatus, and is laminated on an inner layer circuit via an adhesive or a prepreg to form a power feeding layer. There is also.

Japanese Patent Laid-Open No. 10-4254 JP 2003-158364 A Japanese Unexamined Patent Publication No. 7-221444

  Among the above known methods, the method of forming unevenness of several μm on the resin and the method of forming the circuit on the resin-added metal foil by the semi-additive method not only hinders the formation of fine wiring, but also the roughened shape. In addition, the roughened shape causes a problem that the electrical characteristics are degraded. In addition, a method of forming a copper layer of about 1 μm on one side of a polyimide film using an electron beam evaporation apparatus and laminating it on an inner layer circuit via an adhesive or a prepreg, and forming a power feeding layer does not form a rough shape, Although it is advantageous in terms of formation of fine wiring and electrical characteristics, the substrate itself becomes expensive, and versatility is poor.

  On the other hand, if a metal foil that has not been roughened is used, fine wiring can be formed and electrical characteristics can be improved. However, since the adhesive strength between the metal foil and the insulating resin is significantly reduced, the practicality is poor. In addition to the adhesive strength between the metal foil and the insulating resin, it is necessary to process the inner layer board when manufacturing the multilayer board. The interface between the smooth insulating resin and the multilayered prepreg exposed by the circuit processing It became clear that the adhesive strength of the same declined as well.

  The present invention solves the problems of the known methods and provides a wiring board that is advantageous in terms of formation of fine wiring, electrical characteristics, and manufacturing cost, and has high reliability and good high-frequency characteristics. Is to provide.

  The present invention includes (A) an aralkyl type epoxy resin and (B) an aralkyl type resin having a phenolic hydroxyl group as an epoxy resin curing agent on a metal foil having a surface ten-point average roughness of Rz = 2.0 μm or less. The present invention relates to a metal foil with an adhesion assistant having an adhesion assistant layer having a thickness of 0.1 to 10 μm made of an epoxy resin composition. (B) As an epoxy resin hardening | curing agent, you may contain 3-50 equivalent% of triazine ring containing novolak-type resin which has phenolic hydroxyl group further.

  The epoxy resin composition may further contain (C) a rubber component. In this case, the component (C) is preferably 0.5 to 25 parts by weight per 100 parts by weight of the (A) component. Component (C) is at least one selected from acrylonitrile butadiene rubber, carboxylic acid modified acrylonitrile butadiene rubber, carboxylic acid modified acrylonitrile butadiene rubber particles, butadiene rubber-acrylic resin core shell particles, polyvinyl acetal resin, and carboxylic acid modified polyvinyl acetal resin. It is preferable to contain.

  It is preferable that the surface of the metal foil contained in the metal foil with an adhesion assistant is not roughened. The metal foil is preferably a copper foil that has been rust-prevented with at least one selected from nickel, tin, zinc, chromium, molybdenum, cobalt, and oxides thereof.

  Moreover, this invention relates to the printed wiring board produced using said metal foil with an adhesion adjuvant. Furthermore, this invention relates to the manufacturing method of the printed wiring board using said metal foil with an adhesion adjuvant.

According to the metal foil with an adhesion aid of the present invention, it is advantageous in terms of fine wiring formation, electrical characteristics, and manufacturing cost, and it is possible to provide a wiring board with high reliability and good high frequency characteristics. Become.
In addition, by using the metal foil with an adhesion aid of the present invention, it is possible to form a fine wiring, while having a peeling strength almost equal to that when using a normal copper foil, and A multilayer wiring board having excellent moisture absorption heat resistance can be produced.

As for the surface roughness of the metal foil used in the present invention, the 10-point average roughness (Rz) shown in JISB0601 is preferably 2.0 μm or less on both sides in terms of electrical characteristics. Although copper foil, nickel foil, aluminum foil, etc. can be used for metal foil, copper foil is usually used. When the metal foil is a copper foil, the production conditions of the copper foil are 50 to 100 g / L sulfuric acid, 30 to 100 g / L copper, 20 to 80 ° C. liquid temperature, and 0.5 to 100 A current density in the case of a copper sulfate bath. / Dm ₂ conditions, in the case of a copper pyrophosphate bath, potassium pyrophosphate 100-700 g / L, copper 10-50 g / L, liquid temperature 30 ° C.-60 ° C., pH 8-12, current density 1-10 A / dm ² Conditions are generally used, and various additives may be added in consideration of the physical properties and smoothness of copper. The metal foil is usually subjected to a roughening process called a roughening process, but the present invention is characterized in that a substantial roughening process is not performed and the metal foil has no legs. “The metal foil does not have legs” means that the metal foil has few irregularities. If the metal foil has few irregularities, the copper foil residue does not remain in a portion where there is no circuit on the resin during etching.

  Moreover, if Rz = 2.0 μm or less, a glossy surface on which the metal foil is not roughened can be used.

  The thickness of the metal foil is not particularly limited. A metal foil having a thickness of 105 μm or less that is generally used for a printed wiring board may be used, but a metal foil having a surface roughness Rz of 2.0 μm or less on both sides may be used. In order to form finer wiring, it is preferable to use a metal foil of a peelable type having a thickness of 5.0 μm or less and a surface roughness Rz of 2.0 μm or less on both sides. Instead of the peelable type, an etchable type metal foil having an aluminum carrier or a nickel carrier can also be used.

Rust prevention treatment performed on the resin adhesive surface of the metal foil can be performed using nickel, tin, zinc, chromium, molybdenum, cobalt and any of these oxides, or alloys thereof, but from zinc and chromium It is preferable to be performed by at least one selected. In these methods, a thin film is formed on a metal foil by sputtering, electroplating or electroless plating, but electroplating is preferable from the viewpoint of cost. Specifically, plating is performed using a plating layer containing one or more metal salts of nickel, tin, zinc, chromium, molybdenum, and cobalt. From the viewpoint of reliability and the like later, it is preferable to perform plating containing zinc. In order to facilitate the precipitation of metal ions, a complexing agent such as citrate, tartrate or sulfamic acid can be added in the required amount. The plating solution is usually used in an acidic region and is performed at a temperature of room temperature to 80 ° C. The plating is appropriately selected from the range of usually a current density of 0.1 to 10 A / dm ² and a current application time of 1 to 60 seconds, preferably 1 to 30 seconds. 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 preventive treatment is too thick, it may cause etching inhibition and deterioration of electrical characteristics, and if it is too thin, it may cause a reduction in peel strength with the resin.

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. It is good to carry out under conditions of 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. It can also carry out 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 metal foil. Examples of the silane coupling agent 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, etc. Mercapto functionality Orchids, such as 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 can be used alone or in combination.

  These coupling agents are dissolved in a solvent such as water at a concentration of 0.1 to 15 g / L and applied to a metal foil at a temperature of room temperature to 50 ° C. or electrodeposited to be adsorbed. These silane coupling agents form a film by condensation bonding with a hydroxyl group of a rust-preventing metal on the surface of the metal foil. After the silane coupling treatment, a stable bond is formed by heating, ultraviolet irradiation or the like. If heated, it is dried at a temperature of 100 to 200 ° C. for 2 to 60 seconds. In the case of ultraviolet irradiation, it is carried out in the range of 200 to 400 nm and 200 to 2500 mJ / cm2.

  An adhesion aid made of an epoxy resin composition is applied on the metal foil that has been treated with the silane coupling agent. The applied thickness is preferably 0.1 to 10 μm, and more preferably 2.0 to 5.0 μm. If it is less than 0.1 μm, the adhesion assisting effect may not be manifested, and if it exceeds 10 μm, it may cause deterioration in characteristics such as heat resistance and dielectric properties of the interlayer insulating material.

  The adhesion aid of the present invention is an epoxy resin composition comprising (A) an aralkyl type epoxy resin and (B) an aralkyl type resin having a phenolic hydroxyl group as an epoxy resin curing agent.

The aralkyl type epoxy resin of component (A) is represented by Chemical Formula 1. Here, X and Y represent an aromatic ring such as a benzene ring, a naphthalene ring, or a biphenyl structure, and hydrogen in the aromatic ring of X and Y may be substituted. Examples of the substituent include a methyl group, an ethyl group, a propyl group, and a phenyl group. n represents a repeating unit and is not particularly limited.

  Specific examples of the aralkyl type epoxy resin include, but are not limited to, the following formulas 2 to 4.

For example, Formula 2:

(Wherein n represents 1 to 5). In particular, an epoxy resin containing an aromatic ring having a biphenyl structure in the molecule (chemical formula 3):

(Wherein n represents 1 to 5) and epoxy resin containing an aromatic ring having a naphthalene structure in the molecule (chemical formula 4):

  (In the formula, n represents 1 to 5.) However, it is effective because the peel strength and heat resistance of the metal foil are excellent.

  These resins can be used alone or in admixture of two or more. In addition to (A) aralkyl type epoxy resin, other epoxy resins such as bisphenol A type epoxy resin, phenol novolac type epoxy resin, rubber-modified epoxy resin, etc. within 50% by weight or less of the total amount of epoxy resin May be used in combination.

  (A) Examples of commercially available aralkyl epoxy resins include EXL-3L manufactured by Mitsui Chemicals, NC-3000S and NC-3000S-H manufactured by Nippon Kayaku Co., Ltd., manufactured by Nippon Steel Chemical Co., Ltd. ESN-170, ESN-480, etc. are mentioned.

(B) The aralkyl type resin having a phenolic hydroxyl group which is an epoxy resin curing agent is represented by Chemical Formula 5. Here, X and Y represent an aromatic ring such as a benzene ring, a naphthalene ring, or a biphenyl structure, and hydrogen in the aromatic ring of X and Y may be substituted. Examples of the substituent include a methyl group, an ethyl group, a propyl group, and a phenyl group. n represents a repeating unit and is not particularly limited.

  Specific examples of the aralkyl type resin having a phenolic hydroxyl group include, but are not limited to, the following formulas 6 to 8.

Chemical formula 6:

(Wherein n represents 1 to 5), and in particular, a phenolic resin containing an aromatic ring having a biphenyl structure in the molecule (chemical formula 7):

(Wherein n represents 1 to 5) or a naphthol resin containing an aromatic ring having a naphthalene structure (Chemical Formula 8):

  (In the formula, n represents 1 to 5) is effective because the peel strength and heat resistance of the metal foil are excellent. These resins can be used alone or in admixture of two or more. In addition, as the component (B), other epoxy resin curing agents such as bifunctional phenols such as bisphenol A, novolac type phenol resins, and amino resins may be used in the range of 50% by weight or less.

  Examples of commercially available aralkyl-type resins having a phenolic hydroxyl group include XLC-3L manufactured by Mitsui Chemicals, HEM-7851 manufactured by Meiwa Kasei Co., Ltd., SN-170 and SN-480 manufactured by Nippon Steel Chemical Co., Ltd. .

  As the component (B), it is more preferable to use a triazine ring-containing novolac resin having a phenolic hydroxyl group in combination with the aralkyl type resin having a phenolic hydroxyl group as described above, thereby improving the peel strength of the metal foil. When the addition amount of the triazine ring-containing novolak resin having a phenolic hydroxyl group is 3 to 50 equivalent% of the epoxy resin curing agent, it is possible to improve the peeling strength of the metal foil while maintaining the heat resistance. More preferred.

  In the present invention, the triazine ring-containing novolak type resin having a phenolic hydroxyl group refers to a novolak type phenol resin containing a triazine ring in the main chain, such as a novolak type phenol resin, and may be a cresol novolak type phenol resin containing a triazine ring. Absent. The nitrogen content is preferably 10 to 25% by weight, more preferably 12 to 19% by weight in the triazine ring-containing novolak resin. When the nitrogen content in the molecule is within this range, the dielectric loss does not increase too much, and when the adhesion aid is used as a varnish, the solubility in the solvent is appropriate, and the remaining amount of undissolved substances can be suppressed. . As the triazine ring-containing novolac resin, one having a number average molecular weight of 300 to 1,000 can be used. These may be used alone or in combination of two or more.

  The triazine ring-containing novolac type phenol resin can be obtained by reacting phenol, 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. Any of o-, m-, and p-cresol can be used as the cresol, and melamine, guanamine and derivatives thereof, cyanuric acid and derivatives thereof can be used as the triazine ring-containing compound.

  Although not limited to the following examples as a commercial item, Dainippon Ink Chemical Co., Ltd. triazine ring containing cresol novolac type phenol resin phenolite LA-3018 (nitrogen content 18 weight%) is mentioned. These resins can be used alone or in admixture of two or more.

  (C) The rubber component is not particularly limited, but is preferably a crosslinked rubber particle so as not to lower the heat resistance, and is preferably an acrylonitrile butadiene rubber particle, a carboxylic acid modified acrylonitrile butadiene rubber particle, a butadiene rubber-acrylic resin core shell. It is preferable to consist of at least one selected from particles.

  The acrylonitrile butadiene rubber particles are those obtained by copolymerizing acrylonitrile and butadiene and partially cross-linking at the stage of copolymerization. It is also possible to obtain carboxylic acid-modified acrylonitrile butadiene rubber particles by copolymerizing together carboxylic acids such as acrylic acid and methacrylic acid. The core-shell particles of butadiene rubber-acrylic resin can be obtained by a two-stage polymerization method in which butadiene particles are polymerized by emulsion polymerization, followed by addition of monomers such as acrylic acid ester and acrylic acid. The size of the particles can be 50 nm to 1 μm, preferably 50 to 100 nm, as a primary average particle size. The rubber particles may be used alone or in combination of two or more.

  For example, as commercial products of carboxylic acid-modified acrylonitrile butadiene rubber particles, XER-91 manufactured by JSR Corporation can be mentioned, and as core shell particles of butadiene rubber-acrylic resin, EXL-2655 manufactured by Kureha Chemical Industry Co., Ltd. AC-3832 of a corporation | Co., Ltd. is mentioned.

As the component (C), a polyvinyl acetal resin, a carboxylic acid-modified polyvinyl acetal resin, or the like can be used.

  The kind of polyvinyl acetal resin, the amount of hydroxyl groups, and the amount of acetyl groups are not particularly limited, but 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, a trade name, SLECK BX-1, BX-2, BX-5, BX-55, BX-7, BH-3, BH-S, KS-3Z, manufactured by Sekisui Chemical Co., Ltd. KS-5, KS-5Z, KS-8, KS-23Z, trade names manufactured 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.

  When the crosslinked rubber particles and the polyvinyl acetal resin are used in combination as the component (C), the peeling strength of the metal foil and the peeling strength of the electroless plating after chemical roughening are further improved.

  The amount of component (C) is preferably 0.5 to 25 parts by weight of component (C) with respect to 100 parts by weight of component (A). If the component (C) is less than 0.5 parts by weight, the peel strength of the metal foil and the peel strength of the electroless plating after chemical roughening are low, and if it exceeds 25 parts by weight, solder heat resistance and insulation reliability are reduced. May decrease. In particular, when 1 part by weight or more of each of the crosslinked rubber particles and the polyvinyl acetal resin is contained relative to the component (A), the peeling strength of the metal foil and the peeling strength of the electroless plating after chemical roughening are improved. And more preferable.

Furthermore, it is more preferable to add the epoxy resin (D) reaction accelerator to the epoxy resin composition of the adhesion auxiliary layer. Any component may be used as the component (D), but it is preferable to mix various imidazoles and BF ₃ amine complexes which are latent thermosetting agents. 2-Phenylimidazole, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazolium trimellitate from the standpoint of storage stability of adhesion aids, handleability at B-stage and solder heat resistance Is preferred.

  The amount of component (D) is preferably in the range of 0.1 to 5 parts by weight and more preferably in the range of 0.3 to 1 part by weight with respect to 100 parts by weight of the epoxy resin (A) in the adhesion assistant. Within these ranges, sufficient solder heat resistance, good storage stability of the adhesion aid, and good handleability when using the B stage can be obtained.

  In order to improve flame retardancy, the adhesion aid of the present invention may contain (E) a flame retardant. There are brominated flame retardants and phosphorus flame retardants as component (E), but any flame retardant may be used.

  Examples of the component (E) include brominated epoxy resins having a tetrabromobisphenol A skeleton and epoxy resin curing agents such as tetrabromobisphenol A. Similarly, phosphorus-based flame retardants include phosphorus-containing epoxy resins and phenolic hydroxyl group-containing phosphorus compounds.

  Examples of commercially available phosphorus-based flame retardants include FX-305 manufactured by Tohto Kasei and HCA-HQ manufactured by Sanko Co., Ltd.

  When imparting flame retardancy, the blending amount of (E) flame retardant in the adhesion aid of the present invention is calculated in terms of bromine atoms in the total weight of components (A) to (E) and (F) inorganic filler. A range of 1.0 to 3.5% by weight, preferably 1.0 to 3.5% by weight in terms of phosphorus atoms. 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.

  In order to improve reliability, the adhesion aid in the present invention may contain (F) an inorganic filler.

  The component (F) in the present invention is not particularly limited, and examples thereof include silica, fused silica, talc, alumina, aluminum hydroxide, barium sulfate, calcium hydroxide, aerosil and calcium carbonate. Inorganic fillers include those treated with various coupling agents such as silane coupling agents 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 blending amount of the component (F) is preferably in the range of 5 to 35% by volume, more preferably 10 to 30% by volume, in the total volume of the components (A) to (F). When the blending amount is within this range, the thermal expansion coefficient and the dielectric loss are not increased, and a sufficient flow can be obtained for forming the insulating layer on the inner layer circuit. In order to disperse the inorganic filler in the adhesion aid of the present invention, a known kneading method such as a kneader, a ball mill, a bead mill, or a three roll can be used.

  You may mix | blend additives, such as a pigment, a leveling agent, an antifoamer, and an ion trap agent, with the adhesion adjuvant of this invention as needed.

  The adhesion aid produced as described above is diluted with a solvent to form a varnish, which is applied to a copper foil. Examples of the solvent include, but are not limited to, ketones such as acetone, methyl ethyl ketone, and cyclohexanone, aromatic hydrocarbons such as benzene, xylene, and toluene, alcohols such as ethylene glycol monoethyl ether, and ethyl ethoxy. Examples thereof include esters such as propionate, and amides such as N, N-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 an adhesion adjuvant is not specifically limited, It can be set as the quantity currently used conventionally.

  The adhesion aid of the present invention or the above varnish is applied to one side of a metal foil and semi-cured to complete a metal foil with an adhesion aid.

  When coating a metal foil with a comma coater or a gravure coater using an adhesion assistant as a varnish, it is preferable to adjust the amount of solvent used so that the total solid content of the adhesion assistant is 10 to 30% by weight. Also, the amount can be adjusted according to the equipment for film formation.

  The substrate using the metal foil with an adhesion auxiliary agent as described above is prepared by combining the metal foil with an adhesion auxiliary agent and the prepreg by a conventionally known method so that the adhesion auxiliary agent layer of the metal foil with an adhesion auxiliary agent is on the prepreg side. Obtained by laminating and integrating. By the method described above, a laminate consisting of two layers is completed. A printed wiring board can be obtained by forming a circuit by a known method.

  When the laminated board produced as described above is used as the inner layer board, the surface roughness of the conductor circuit is Rz = 2.0 μm or less, and the surface roughness of the insulating layer of the inner layer board is Rz = 2.0 μm or less. Is desirable in terms of formability of fine circuits and electrical characteristics.

  Furthermore, a multilayer printed wiring board can be obtained by stacking a multilayered prepreg and a metal foil with an adhesion auxiliary material, multilayering by a known method, and forming a circuit. In the multilayer printed wiring board produced as described above, the surface roughness of the conductor circuit is preferably Rz = 2.0 μm or less, and the surface roughness of the insulating layer of the inner layer board is preferably Rz = 2.0 μm or less in terms of electrical characteristics.

(Example 1)
The resin composition 1 shown below was produced.

(Preparation of resin composition 1)
Aralkyl type epoxy resin, ESN-480 (manufactured by Nippon Steel Chemical Co., Ltd.) 62 parts by weight Aralkyl type resin having a phenolic hydroxyl group, HEM-7851 (manufactured by Meiwa Kasei Co., Ltd.) 30 parts by weight Carboxylic acid modified acrylonitrile butadiene Rubber particles, XER-91SE-15 (manufactured by JSR Corporation) 8 parts by weight, imidazole derivative compound, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2PZ-CNS (manufactured by Shikoku Chemicals Co., Ltd.) 0.3 part by weight, solvent , Methyl ethyl ketone
(Production of metal foil 1)
The resin composition 1 was applied to the adherend surface of an electrolytic copper foil having a width of 510 mm and a thickness of 18 μm (product name F0-WS18: manufactured by Furukawa Circuit Foil Co., Ltd. Rz = 1.2 μm) to prepare a metal foil 1. After coating, drying was performed at 170 ° C. for about 10 minutes so that the residual solvent was 3% or less. The thickness of the coated resin composition 1 was 3.0 μm.

  Glass foil base material high Tg epoxy resin prepreg GEA-679F (thickness 0.1 mm) manufactured by Hitachi Chemical Co., Ltd. Metal foil 1 is attached so that the surface coated with resin composition 1 on the top and bottom thereof is in contact with the prepreg. Laminated and press-molded at 180 ° C. and 2.5 MPa for 1 hour to produce a copper-clad laminate.

  Next, a dry film photoresist was laminated on the surface of the copper clad laminate, exposed to ultraviolet rays through a photomask that masked a portion to be etched, and developed to form an etching resist.

  A circuit pattern was formed so that the minimum circuit conductor width / circuit conductor interval (L / S) = 30/30 μm, and the resist was peeled off to produce an inner layer plate. The surface roughness Rz of the insulating layer of the core substrate was 1.2 μm, and the surface roughness Rz of the conductor circuit was 1.1 μm. The surface roughness was measured based on JIS-B-0601.

  Next, after the inner layer circuit was bonded by oxidation-reduction treatment, one glass cloth base material high-Tg epoxy resin prepreg GEA-679F (thickness 0.1 mm) and the resin composition 1 were coated on the top and bottom thereof. The metal foil 1 was laminated so that the surface was in contact with the prepreg, and press-molded at 180 ° C. and 2.5 MPa for 1 hour to produce a copper-clad multilayer board. Thereafter, similarly to the inner layer board, a circuit pattern was produced using an etching resist to produce a multilayer wiring board, which was used as a sample for evaluation. The surface roughness Rz of the insulating layer of the core substrate was 1.2 μm, and the surface roughness Rz of the conductor circuit was 1.1 μm.

(Example 2)
In Example 1, when producing the metal foil 1, a sample for evaluation was produced in the same manner as in Example 1 except that the resin composition 1 was applied to a thickness of 6 μm.

(Example 3)
In Example 1, 62 parts by weight of NC3000S-H (manufactured by Nippon Kayaku Co., Ltd.) as the aralkyl type epoxy resin, 20 parts by weight of SN-480 (manufactured by Nippon Steel Chemical) as the aralkyl type resin having a phenolic hydroxyl group, triazine 10 parts by weight of ring-containing cresol novolac type phenol resin LA-3018 (manufactured by Dainippon Ink Co., Ltd.) was used. The other operations were performed in the same manner as in Example 1.

(Example 4)
In Example 3, instead of 8 parts by weight of carboxylic acid-modified acrylonitrile butadiene rubber particles, 8 parts by weight of butadiene rubber-acrylic resin core-shell particles, EXL-2655 (Kureha Chemical Industry Co., Ltd.) were used. Others were performed in the same manner as in Example 3.

(Example 5)
In Example 3, 5 parts by weight of polyvinyl acetal resin, KS-23Z (manufactured by Sekisui Chemical) was added. Others were performed in the same manner as in Example 3.

(Comparative Example 1)
In Example 1, an evaluation sample was prepared in the same manner as in Example 1 except that 18 μm of F0-WS foil (manufactured by Furukawa Circuit Foil) was laminated instead of laminating the metal foil 1.

(Comparative Example 2)
When preparing the resin composition 1 of Example 1, 60 parts by weight of cresol novolac type epoxy resin, N-665 (manufactured by Dainippon Ink Co., Ltd.) was used as the epoxy resin, and novolak type phenol resin HP was used as the epoxy resin curing agent. An evaluation sample was prepared in the same manner as in Example 1 except that -850N (manufactured by Hitachi Chemical Co., Ltd.) was changed to 30 parts by weight.

(Measurement of conductor peeling strength)
The conductor peeling strength of the evaluation samples for Examples 1 to 6 and Comparative Examples 1 and 2 was measured. For peeling, the vertical peeling strength was measured. Measurements were always made at 20 ° C. The measurement method conformed to JIS-C-6481.

(Hygroscopic heat resistance test)
The moisture absorption heat test of the sample for evaluation for Examples 1-6 and Comparative Examples 1-2 was performed. In the board test, each sample was treated 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. It was. A saturation type PCT device PC-242 manufactured by Hirayama Seisakusho was used for the test.

(Test results)
The test results are shown in Table 1. The samples for evaluation produced in Examples 1 to 6 all had a high conductor peeling strength of 0.7 kN / m or higher. On the other hand, the samples for evaluation obtained in Comparative Examples 1 and 2 had a weak conductor peeling strength, and swelling occurred between the inner layer conductor and the insulating layer after the moisture absorption heat test.

Claims (5)

A thickness of 0 consisting of an epoxy resin composition comprising (A) an aralkyl type epoxy resin, (B) an aralkyl type resin having a phenolic hydroxyl group as an epoxy resin curing agent, and (C) a crosslinked rubber particle and a polyvinyl acetal resin as a rubber component. .1-10 μm adhesion auxiliary layer.   2. The adhesion auxiliary layer according to claim 1, further comprising (B) 3 to 50 equivalent% of a triazine ring-containing novolac resin having a phenolic hydroxyl group as the epoxy resin curing agent. The content of the previous SL (C) a rubber component, 0 against to 100 parts by weight of component (A). It is 5-25 weight part, The adhesion auxiliary layer of Claim 1 or 2 characterized by the above-mentioned. The crosslinked rubber particles are acrylonitrile-butadiene rubber, carboxylic acid-modified acrylonitrile butadiene rubber, carboxylic acid-modified acrylonitrile-butadiene rubber particles and butadiene rubber - characterized in that it comprises at least one selected from the core-shell particles children or al the group consisting of acrylic resin The adhesion auxiliary layer according to any one of claims 1 to 3.   The adhesion auxiliary layer according to any one of claims 1 to 4, wherein the polyvinyl acetal resin is a carboxylic acid-modified polyvinyl acetal resin.