JP2004082737A - Substrate with conductor layer and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a substrate having a conductor layer used for a printed circuit board which is excellent in a tracking-resistance characteristic without spoiling an electrical insulation, and its manufacturing method. <P>SOLUTION: The substrate with conductor layer comprises the conductor layer and an insulation layer superposed on the conductor layer through the film made by hardening an adhesive. The adhesive is blended with bridged acrylonitrile butadiene rubber particles at the time of applying. <P>COPYRIGHT: (C)2004,JPO

Description

(4) The present invention relates to a conductor layer-containing substrate and a method for producing the same.

Additive method The manufacturing process of a printed wiring board will be schematically described. First, an adhesive layer containing a plating catalyst is formed on an insulating substrate containing a plating catalyst, and cured by heating at a temperature of 140 to 190 ° C. for 20 to 90 minutes. Next, the surface of the adhesive other than the portion where a circuit is to be formed is masked with a plating resist, and the unmasked adhesive surface is selectively chemically roughened using an oxidizing acid. Then, the wiring pattern is formed by immersing in an electroless plating solution to precipitate copper on the adhesive. In the additive multilayer printed wiring board, a circuit board on which a circuit has been formed is used as an inner layer material instead of an insulating substrate, and an insulating layer between a conductor layer and a surface conductor layer of the inner layer material is formed with a similar adhesive.

The insulating substrate is obtained by impregnating a liquid thermosetting resin containing a plating catalyst into a fibrous base material, heating the impregnated thermosetting resin to the B stage, curing a predetermined number of prepregs, and heating and pressing the prepregs. A laminate is used. The adhesive is used to secure adhesion between the circuit formed by plating and the insulating substrate. This adhesive plays an extremely important role in an additive printed wiring board, and it is essential that the adhesive has excellent adhesiveness and heat resistance.

As an adhesive component of the adhesive, acrylonitrile-butadiene rubber, which generally has good adhesion to plated copper, is used as a main component, and an alkylphenol resin as a cross-linking agent, and an epoxy resin blended to secure electrical characteristics. Is used. In addition to the resin component, an inorganic filler may be blended in order to reinforce the adhesive coating film or to easily form irregularities on the adhesive surface during chemical roughening (see Patent Documents 1 to 4 and the like).
Japanese Patent Publication No. 45-9843 JP-B-48-24250 Japanese Patent Publication No. 55-16391 Japanese Patent Publication No. 1-53910

In recent years, as electronic devices have become smaller and more multifunctional, it has become necessary to increase the wiring density of printed wiring boards, and wiring widths have been rapidly reduced. From such a background, an adhesive which is in direct contact with a circuit conductor is becoming an important property in terms of insulation. Therefore, in general, the amount of acrylonitrile-butadiene rubber, which is inferior to epoxy resin or the like, is reduced, and the amount of epoxy resin is increased. However, when the amount of the acrylonitrile-butadiene rubber is reduced and the amount of the epoxy resin is increased, the tracking resistance decreases. An object of the present invention is to provide a conductor layer-containing substrate for a printed wiring board excellent in tracking resistance without impairing electrical insulation and a method for producing the same.

導体 The conductor layer-containing substrate of the present invention is characterized by being obtained by bonding a conductor layer and an insulating layer using an adhesive in which crosslinked acrylonitrile butadiene rubber particles are blended in addition to the adhesive component.

The crosslinked acrylonitrile-butadiene rubber particles used in the present invention are fine high molecular weight crosslinked rubber particles having a primary average particle diameter of about 50 to 100 nm obtained by crosslinking acrylonitrile-butadiene rubber in an emulsion state after emulsion polymerization. The presence or absence of modification with a carboxyl group does not matter. The compounding amount is 2 to 50% by weight in the adhesive composition. If the content is 2% by weight or less, there is no effect on the improvement of the tracking resistance. If the content is 50% by weight or more, the tackiness of the adhesive surface increases, and a problem such as adhesion of dust in a later step occurs.

樹脂 The basic resin composition of the adhesive is not particularly limited as long as it is an adhesive composition used for an additive printed wiring board. A mixture of an epoxy resin, acrylonitrile-butadiene rubber, a resol-type phenol resin, and an inorganic filler is preferable in consideration of plating solution resistance, coating film forming properties, roughening properties, and the like. If necessary, a plating catalyst serving as a deposition nucleus for electroless copper plating is contained in the adhesive. Examples of the plating catalyst include salts or oxides of metals belonging to Group 8, Group 1B or Group 2B in the periodic table. For example, a compound such as platinum, palladium, or tin is used, and is mixed with the adhesive in a solution state of being dissolved in solid particles or an organic solvent or dissolved and dispersed together with another resin. The amount of the plating catalyst is in the range of 2 to 15% by weight based on the total amount of the adhesive.

各 Each component of the adhesive is kneaded and mixed in an organic solvent to prepare a solution mixture. As the organic solvent to be used, a single or mixed system of toluene, methyl ethyl ketone, acetone, methyl isobutyl ketone, xylene, diethylene glycol monomethyl ether, diethylene glycol monomethyl ether acetate, ethoxypropionate ethyl, propylene glycol monomethyl ether and the like can be used. . As the insulating substrate using the adhesive according to the present invention, a substrate made of a phenol resin or epoxy resin, or an inorganic or organic composite, or the like can be used.

The adhesive is applied directly to the insulating substrate to a thickness of 10 to 50 μm, and cured by heating at a temperature of 120 to 190 ° C. for 30 to 60 minutes. Alternatively, the adhesive sheet (dry film) may be applied to a heat-resistant base film in a thickness of 10 to 100 μm and cured by heating at a temperature of 120 to 190 ° C. for 3 to 15 minutes. As the heat-resistant base film, an organic material such as polypropylene, polybutylene, polyamide, polycarbonate, polyethersulfone, or polyethylene terephthalate; or a metal film such as copper foil or aluminum foil, whose surface is subjected to release treatment is used. be able to. The adhesive sheet is formed by laminating a predetermined number of prepregs, laminating on one or both sides thereof such that the adhesive layer is on the prepreg side, and applying heat and pressure to form a laminate for an additive method printed wiring board. . In addition, when forming an additive method multilayer printed wiring board, a wiring board on which a circuit has been formed is used as an inner layer material, and an insulating layer between a conductor layer of the inner layer material and a surface conductor layer is formed with the adhesive.

析出 When depositing electroless plating, the surface of the adhesive is chemically roughened to a shape suitable for bonding. As a roughening solution used for chemical roughening, a chromium-sulfuric acid system, a chromium-sulfuric acid-sodium fluoride system, an alkali-permanganate system, a borofluoric acid-bichromic system system, and the like can be used. The pattern is formed by screen-printing a plating resist or by curing and developing a photomask with ultraviolet rays. The plating resist is formed before or after the chemical roughening step.

According to the present invention, it is possible to obtain a conductive layer-containing substrate excellent in tracking resistance and an additive printed wiring board using the same, without impairing the insulating property and the adhesion of plated copper.

Hereinafter, the present invention will be described in more detail with reference to examples.

Preparation of Adhesive Crosslinked acrylonitrile butadiene rubber particles (manufactured by Nippon Synthetic Rubber Co., Ltd., trade name: XER-91) 20 parts (parts by weight, the same applies hereinafter), bisphenol A type epoxy resin (manufactured by Yuka Shell Co., Ltd., trade name) : Epicoat 1001) 20 parts, acrylonitrile butadiene rubber, (manufactured by Nippon Zeon Co., Ltd., trade name: Nipol 1031) 20 parts, alkylphenol resin (manufactured by Hitachi Chemical Co., Ltd., trade name: Hitachinol 2400) 5 parts, 2-ethyl- 0.1 part of 4-methylimidazole, 10 parts of zirconium silicate (manufactured by Hakusui Chemical Co., Ltd., trade name: Micropacks), and a catalyst for electroless plating (addition material for palladium chloride) (manufactured by Hitachi Chemical Co., Ltd.) Name: Cat # 11) 4 parts were mixed in a solvent.

Production of Laminate for Additive Method Printed Wiring Board The obtained adhesive is applied to a glass woven fabric base epoxy resin laminate by a dip coating method, and an adhesive layer having a thickness of 25 μm is formed on both surfaces. For 60 minutes.

Preparation of Adhesive Crosslinked acrylonitrile butadiene rubber particles (manufactured by Nippon Synthetic Rubber Co., Ltd., trade name: XER-91) 20 parts (parts by weight, the same applies hereinafter), bisphenol A type epoxy resin (manufactured by Yuka Shell Co., Ltd., trade name) : Epicoat 1001) 50 parts, acrylonitrile butadiene rubber (manufactured by Nippon Zeon Co., Ltd., trade name: Nipol 1031), 20 parts, alkylphenol resin (manufactured by Hitachi Chemical Co., Ltd., trade name: Hitachinol 2400) 5 parts, 2-ethyl-4 -0.1 part of methyl imidazole, 10 parts of zirconium silicate (trade name: Micropax, manufactured by Hakusui Chemical Co., Ltd.), and a catalyst for electroless plating (addition material for palladium chloride) (trade name, manufactured by Hitachi Chemical Co., Ltd.) : Cat # 11) 4 parts were mixed in a solvent.

Production of Laminated Board for Additive Method Printed Wiring Board The obtained adhesive is applied to a release film of a separator film (manufactured by Tokyo Cellophane Co., Ltd., trade name: Toucero Separator) to a thickness of 50 μm, and then at 150 ° C. for 5 minutes. Heated. Eight epoxy resin prepregs containing a plating catalyst were stacked, and the adhesive sheet was stacked on both outer sides with the adhesive layer being on the prepreg side, and heated and pressed at 3 MPa and 170 ° C. for 60 minutes to remove the separator film.

Preparation of Adhesive Crosslinked acrylonitrile butadiene rubber particles (manufactured by Nippon Synthetic Rubber Co., Ltd., trade name: XER-91) 40 parts (parts by weight, the same applies hereinafter), bisphenol A type epoxy resin (manufactured by Yuka Shell Co., Ltd., trade name) : Epicoat 1001) 20 parts, acrylonitrile butadiene rubber, (manufactured by Nippon Zeon Co., Ltd., trade name: Nipol 1031) 20 parts, alkylphenol resin (manufactured by Hitachi Chemical Co., Ltd., trade name: Hitachinol 2400) 5 parts, 2-ethyl- 0.1 part of 4-methylimidazole, 10 parts of zirconium silicate (manufactured by Hakusui Chemical Co., Ltd., trade name: Micropax), and a catalyst for electroless plating (addition material for palladium chloride) (manufactured by Hitachi Chemical Co., Ltd.) Name: Cat # 11) 4 parts were mixed in a solvent.

Production of Laminate for Additive Method Printed Wiring Board The obtained adhesive is applied to a glass woven fabric base epoxy resin laminate by a dip coating method, and an adhesive layer having a thickness of 25 μm is formed on both surfaces. For 60 minutes.

Comparative Example 1
A laminate for an additive method printed wiring board was obtained in the same manner as in Example 1 except that the crosslinked acrylonitrile-butadiene rubber particles in the adhesive were removed.

Comparative Example 2
A laminate for an additive method printed wiring board was obtained in the same manner as in Example 2 except that the crosslinked acrylonitrile butadiene rubber particles in the adhesive were removed.

Comparative Example 3
A laminate for an additive method printed wiring board was obtained in the same manner as in Example 3 except that the crosslinked acrylonitrile butadiene rubber particles in the adhesive were removed.

A plating resist (manufactured by Hitachi Chemical Co., Ltd., trade name: SR-3000) was laminated on the obtained laminate for an additive method printed wiring board, and a mask film having a required pattern was placed thereon and irradiated with ultraviolet rays for development. . Next, it was immersed in a chromium-sulfuric acid-sodium fluoride roughening solution at 40 ° C. for 5 minutes, and washed with neutralized water. Then, it was put into an electroless copper plating solution (trade name: CC-41, manufactured by Hitachi Chemical Co., Ltd.) to deposit plated copper having a thickness of 35 μm and annealed at 160 ° C. for 60 minutes.

About the obtained printed wiring board, the adhesive strength of plated copper (unit: kN / m), the corrosion resistance at 85 ° C.-85% RH-100 V / 75 μm (unit: h), and the tracking resistance (unit: V / CTI) ). Table 1 shows the results.

Preparation of Adhesive Crosslinked acrylonitrile butadiene rubber particles (manufactured by Nippon Synthetic Rubber Co., Ltd., trade name: XER-91) 10 parts (parts by weight, the same applies hereinafter), bisphenol A type epoxy resin (manufactured by Yuka Shell Co., Ltd., trade name) : Epicoat 1001) 20 parts, acrylonitrile butadiene rubber (manufactured by Zeon Corporation, trade name: Nipol 1031) 20 parts, phenol novolak resin (manufactured by Hitachi Chemical Co., Ltd., trade name: HP-850N) 5 parts, alkylphenol resin ( 5 parts of Hitachi Chemical Co., Ltd., trade name: Hitachinol 2400), 0.1 part of 2-ethyl-4-methylimidazole, 10 parts of zirconium silicate (manufactured by Hakusui Chemical Co., Ltd., trade name: Micropax), and none Electroplating catalyst (addition material for palladium chloride) (manufactured by Hitachi Chemical Co., Ltd.) Name: Cat # 11) 4 parts were mixed in a solvent. The obtained adhesive was applied to a release film of a separator film (manufactured by Tokyo Cellophane Co., Ltd., trade name: Tocello Separator) to a thickness of 100 μm, and heated at 150 ° C. for 5 minutes.

Production of Additive Method Multilayer Printed Wiring Board This film was laminated with a roll laminator on both sides of a 0.8 mm thick glass woven substrate epoxy resin laminate having an inner layer circuit formed thereon. Then, it heated at 170 degreeC for 60 minutes. Further, a plating resist (trade name: SR-3000, manufactured by Hitachi Chemical Co., Ltd.) was laminated, exposed to ultraviolet light, and developed. Next, it was immersed for 5 minutes in a roughening solution of chromium-sulfuric acid-sodium fluoride (chromic acid 40 g / l, concentrated sulfuric acid 300 ml / l, sodium fluoride 10 g / l) kept at 40 ° C. The exposed adhesive surface was selectively chemically roughened, neutralized, and washed with water. Thereafter, the resultant was put into an electroless plating bath (trade name: CC-41, manufactured by Hitachi Chemical Co., Ltd.) to deposit plated copper having a thickness of 35 μm, and annealed at 160 ° C. for 60 minutes.

に The procedure was the same as in Example 4 except that the amount of the crosslinked acrylonitrile-butadiene rubber particles was changed to 40 parts.

Example 4 was carried out in the same manner as in Example 4 except that the amount of the bisphenol A type epoxy resin was changed to 50 parts and the amount of the phenol novolak resin was changed to 13 parts.

Comparative Example 4
Except that the crosslinked acrylonitrile-butadiene rubber particles were excluded, and the amount of the acrylonitrile-butadiene rubber was changed to 30 parts, the same procedure as in Example 4 was carried out.

Comparative Example 5
Example 6 was repeated except that the crosslinked acrylonitrile-butadiene rubber particles in the adhesive were removed.

A 0.2 mm thick epoxy resin prepreg containing a plating catalyst (manufactured by Hitachi Chemical Co., Ltd., trade name: GEA-168N) on both sides of a 0.8 mm thick glass woven base epoxy resin laminate having an inner layer circuit formed thereon. Were laminated and bonded together at 170 ° C. and 3 MPa, and an adhesive prepared with the same composition as in Example 4 was applied to the surface by curtain coating. Hereinafter, it carried out similarly to Example 4.

About the obtained multilayer printed wiring board, the adhesive strength of plated copper (unit: kN / m), the electric corrosion resistance (unit: h) of 85 ° C.-85% RH-100 V / 75 μm, and the tracking resistance (unit: V / m) CTI). Table 2 shows the results.

Claims (6)

In a conductor layer-containing substrate having a conductor layer and an insulating layer superimposed on the conductor layer via an adhesive coating film obtained by curing the adhesive, the adhesive is cross-linked with acrylonitrile butadiene at the time of application. A substrate containing rubber particles. The substrate according to claim 1, wherein the adhesive contains 2 to 50% by weight of crosslinked acrylonitrile butadiene rubber particles when applied. 3. The substrate according to claim 1, wherein the crosslinked acrylonitrile-butadiene rubber particles have an average particle size of 50 to 100 nm. The substrate according to any one of claims 1 to 3, wherein the adhesive coating is formed on the conductor layer to a thickness of 10 to 50 µm. (5) The substrate according to any one of (1) to (4), wherein the conductive layer is copper foil. The method for manufacturing a substrate according to any one of claims 1 to 5, comprising a step of applying an adhesive to the insulating layer.