JP2007242975A - Printed-wiring board and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method for a printed-wiring board being capable of easily forming an extremely fine-line circuit and having the excellent adhesive strength and heat resistance of a copper plating layer. <P>SOLUTION: In the manufacturing method for the printed-wiring board, a B-stage resin composition layer is laminated and molded on the resin-layer surface of a resin composite copper foil forming a block copolymerizing polyimide resin and a resin layer containing a polymaleimide compound on one surface of a copper foil. In the manufacturing method, all the copper foil are etched and removed, the resin-layer surface is exposed and the electroless copper plating layer 5 is formed on the whole surface without irregularly treating the resin-layer surface. An electrolytic copper plating layer is formed, and the electroless copper plating layer 5 and the electrolytic copper plating layer are etched and removed selectively and a copper circuit is formed. Alternately, the electroless copper plating layer 5 is formed, the electrolytic copper-plating pattern layer is formed selectively on the electroless copper plating layer and the electroless copper plating layer forming no electrolytic copper plating layer is etched and removed and the copper circuit is formed. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to a method for manufacturing a printed wiring board in which an ultrafine wire circuit can be easily formed, and a printed wiring board obtained by the manufacturing method. Since the printed wiring board obtained by the production method of the present invention is excellent in the adhesive strength and heat resistance of the copper plating layer, it is suitably used as a high-density printed wiring board having a fine circuit.

In recent years, in order to mount electronic components such as semiconductor components used in electronic devices, printed circuit boards, coupled with the ultra-high density of semiconductor circuits, the circuit conductor width and inter-circuit insulation space can be made finer. It is requested. Conventionally, as a copper foil of a copper clad laminate used for a printed wiring board, an electrolytic copper foil having a good adhesive force and a remarkable unevenness on the surface of the copper foil mat has been used. These electrolytic copper foils have good adhesion, but when forming a fine circuit by etching method, due to the unevenness of the copper foil mat surface, some of the convex portions of the copper foil are If the etching time is extended, the circuit is over-etched to completely remove it, and there is a problem in that the circuit position accuracy and adhesive strength are reduced.

  As these improvement means, what is called a low profile copper foil which suppressed the unevenness | corrugation of the copper foil surface is put into practical use. However, when this copper foil is used in a copper-clad laminate such as a high heat-resistant thermosetting resin that originally has a low adhesive strength, a shortage of adhesive strength becomes a problem in fine circuits, which is a major obstacle to ultra-thin wires. ing. Also, since long ago, in order to improve the adhesion between the copper foil and the insulating resin, a method of forming an insulating adhesive layer on the copper foil has been put into practical use. For example, a technique of forming phenol-butyral resin on a copper foil in a paper phenolic resin copper-clad laminate, and a technique of forming an epoxy resin adhesive on a copper foil in a glass epoxy resin copper-clad laminate are known. Specific examples of these adhesive-attached copper foils include a copper-clad laminate using a copper foil with a thin adhesive layer (see, for example, Patent Document 1) and a copper-clad using a copper foil attached with a semi-cured resin film. Laminates (see, for example, Patent Document 2) have also been proposed, but copper-clad laminates using copper foil with adhesive have problems in terms of adhesive strength level and moisture absorption heat resistance, and further improvements are necessary. Met.

JP-A-8-216340 JP-A-9-11397

  An object of the present invention is to provide a method for producing a printed wiring board, in which an ultrafine wire circuit can be easily formed and the copper plating layer has excellent adhesive strength and heat resistance.

As a result of intensive studies to solve the above problems, the present inventor used a copper-clad laminate using a specific resin composite copper foil, and removed the copper foil by etching to expose the resin layer surface. The present invention finds that a printed wiring board having excellent adhesion and heat resistance can be obtained by forming a copper plating layer without forming unevenness on the surface, and then selectively removing by etching to form a copper circuit. Reached.

  That is, in the present invention, a B-stage resin composition layer is laminated on a resin layer surface of a resin composite copper foil in which a resin layer containing a block copolymerized polyimide resin and a polymaleimide compound is formed on one side of a copper foil, and then laminated and molded. After making the copper clad laminate, the copper foil of the copper clad laminate is all etched away, the resin layer surface is exposed to make a laminate, and electroless copper is obtained without subjecting the resin layer surface of the laminate to uneven treatment. An electroless copper plating layer is formed by plating, and then an electrolytic copper plating layer is formed on the electroless copper plating layer by electrolytic copper plating. Then, the electroless copper plating layer and the electrolytic copper plating layer are selectively removed by etching. Thus, a method for manufacturing a printed wiring board for forming a copper circuit is provided.

  In the present invention, a B-stage resin composition layer is laminated on a resin layer surface of a resin composite copper foil in which a resin layer containing a block copolymerized polyimide resin and a polymaleimide compound is formed on one side of the copper foil, and then laminated to form copper. After forming the laminated laminate, all of the copper foil of the copper-clad laminate is removed by etching, the resin layer surface is exposed to form a laminated plate, and electroless copper plating is performed without roughening the resin layer surface of the laminated plate. After forming an electroless copper plating layer, and then selectively forming an electrolytic copper plating layer on the electroless copper plating layer, at least the electroless copper plating layer on which the electrolytic copper plating layer is not formed is removed by etching. A method of manufacturing a printed wiring board for forming a copper circuit is provided.

  In the method for producing a printed wiring board of the present invention, preferably, after the electroless copper plating layer or the electrolytic copper plating layer is formed, heat treatment is preferably performed at 100 ° C. to 200 ° C. I will provide a.

  In the method for producing a printed wiring board of the present invention, the block copolymerized polyimide resin preferably used is a block copolymerized polyimide resin having structural units represented by the general formulas (1) and (2).

(M and n in the formula are integers satisfying m: n = 1: 9 to 3: 1)
In the method for producing a printed wiring board of the present invention, the resin layer thickness of the resin composite copper foil is more preferably 0.1 μm to 10 μm.

  In the method for producing a printed wiring board of the present invention, the content ratio of the block copolymerized polyimide and the maleimide compound in the resin layer of the resin composite copper foil is more preferably 10 to 90:90 to 10 by weight.

The printed wiring board obtained by the method for manufacturing a printed wiring board according to the present invention enables the formation of a copper circuit with a very fine wire (about 12 μm width), which greatly reduces the width of the conventional fine wire circuit, and has an adhesive force and moisture absorption. Excellent heat resistance. For this reason, it is suitable as a high-density printed wiring board having a fine circuit, and the practicality of the technique of the present invention is extremely high.

  As the copper foil of the copper clad laminate used for the printed wiring board, in order to secure the adhesive strength of the copper foil, a copper foil having a concavo-convex formed on the surface of the copper foil to be bonded and a rust-proof plating layer is used. It is common. However, when forming thin wire circuits by etching, the copper foil cross section tends to be trapezoidal due to the slow etching rate of the copper foil unevenness and the anticorrosion plating layer, and the formation of thin wire circuits with a width of about 50 μm is the limit. there were. In addition, as a method of forming a finer wire, a copper thin wire is selectively plated to a thickness of about 25 μm on an extremely thin copper foil laminate of about 3 μm, and then the copper is etched about 5 μm from the entire surface, Even by the pattern plating method for forming a copper fine wire, the etching rate of the uneven foot portion and the anticorrosive plating layer is slow, and it is difficult to form a copper circuit thinner than about 30 μm.

  Next, the present invention will be described with reference to the drawings. The present invention relates to a method of manufacturing a printed wiring board that solves the limitations of thin wire formation and the problem of low adhesion of copper circuits in circuit formation of copper-clad laminates. The present invention provides a B-stage resin on the resin layer surface of a resin composite copper foil in which a resin layer (2 in FIG. 1) containing a block copolymerized polyimide resin and a polymaleimide compound is formed on one surface of a copper foil (1 in FIG. 1). The composition layers (3 in FIG. 1) are stacked and laminated to form a copper clad laminate. All of the copper foil of the copper-clad laminate is removed by etching to expose the resin layer surface (5 in FIG. 3) to form a laminate. An electroless copper plating layer (6 in FIG. 4) is formed by electroless copper plating without roughening the resin layer surface of the laminate, and then electrolytic copper plating is performed on the electroless copper plating layer by electrolytic copper plating. A layer (7 in FIG. 5) is formed. The present invention relates to a method of manufacturing a printed wiring board in which an electroless copper plating layer and an electrolytic copper plating layer are selectively removed by etching to form a copper circuit (7 in FIG. 6). If necessary, through holes and blind holes (4 in FIG. 2) are formed.

  There are generally two methods for forming a copper circuit by selectively removing the plated copper layer by etching. One is a method of forming a circuit (FIGS. 6 and 8) by coating a portion where a copper circuit on the copper plating layer is formed with an etching resist and using a known etching method. Another method is to cover the thin electroless copper plating layer formed on the entire surface of the laminated plate with a plating resist except for the place where the copper circuit is to be formed, and after forming the electrolytic copper plating layer by pattern plating. In this method, the plating resist is removed and at least the electroless copper plating layer on which the electrolytic copper plating layer is not formed is etched to form a circuit.

  The high adhesive strength of the copper plating layer in the printed wiring board of the present invention is obtained by a resin layer previously formed on the resin composite copper foil. (Adhesion between the resin layer and the thermosetting resin composition is caused by adhering to the resin layer by the adhesive force of the B-stage resin composition.) It can improve more by heat-processing at 100 to 200 degreeC after plating or after completion | finish of electrolytic copper plating. The printed wiring board of the present invention also has extremely excellent heat resistance in component mounting characteristics such as solder reflow after moisture absorption.

  The block copolymerized polyimide preferably used as the resin layer of the resin composite copper foil used in the method for producing a printed wiring board of the present invention is composed of the second structural unit at the end of the imide oligomer composed of the first structural unit. Any copolymerized polyimide having a structure in which an imide oligomer is bonded is not particularly limited. These block copolymerized polyimides are prepared by reacting a tetracarboxylic dianhydride and a diamine in a polar solvent to form an imide oligomer, and then further tetracarboxylic dianhydride and another diamine or another tetracarboxylic dianhydride. It is synthesized by a sequential polymerization reaction in which a product and a diamine are added and imidized. Examples of the polar solvent to be used include polar solvents that dissolve polyimide, such as N-methyl-2-pyrrolidone, dimethylacetamide, dimethylformamide, dimethyl sulfoxide, sulfolane, and tetramethylurea. It is also possible to use a mixture of a ketone or ether solvent, and examples of the ketone solvent include methyl ethyl ketone, methyl propyl ketone, methyl isopropyl ketone, methyl butyl ketone, methyl isobutyl ketone, and methyl-n-hexyl. Ketone, diethyl ketone, diisopropyl ketone, diisobutyl ketone, cyclopentanone, cyclohexanone, methylcyclohexanone, acetylacetone, diacetone alcohol, cyclohexene-n-one are ether solvents such as dipropyl ether, diisopropyl ether, dibutyl ether, tetrahydrofuran, Tetrahydropyran, ethyl isoamyl alcohol, ethyl t-butyl ether, ethyl benzyl ether, diethylene glycol dimethyl ether, quedyl methyl Ether, anisole and phenetole can be used. Moreover, in order to remove the water produced | generated at the time of imidation reaction, it is necessary to add and remove the solvent azeotropically with water, such as toluene and xylene. In order to accelerate the reaction, an amine catalyst such as pyridine or a two-component catalyst of a base and a cyclic ester such as pyridine and γ-valerolactone is preferably used. The reaction temperature is 120-200 ° C, and solvents such as toluene and xylene azeotrope with water and catalysts such as pyridine are finally distilled out of the system to form a polar solvent solution containing only block copolymerized polyimide. It is possible to obtain.

  As the block copolymer polyimide used for the resin layer of the resin composite copper foil used in the present invention, a solvent-soluble block copolymer polyimide having a structural unit represented by the general formula (1) and the general formula (2) is used. Is preferred. The tetracarboxylic dianhydride used in this block copolymerized polyimide is 3,4,3'.4'-biphenyltetracarboxylic dianhydride, and the diamine is 1,3-bis (3-aminophenoxy) benzene. And 2,2-bis {4- (4-aminophenoxy) phenyl} propane. In addition, in order to control the molecular weight of each unit polycondensate, the molar ratio of tetracarboxylic dianhydride and diamine is shifted during the first stage reaction to make the terminal an acid anhydride or amine, and in the second stage reaction the tetra It is possible to obtain a block copolymerized polyimide having a sufficient molecular weight by reversing the molar ratio of carboxylic dianhydride and diamine to that of the first stage. As for the weight average molecular weight (Mw) of the block copolymerization polyimide of this invention, 50000-300000 are desirable. More preferably, it is 80000-200000. If Mw is less than 50000, the resin layer becomes brittle and cannot be used for this purpose. On the other hand, if Mw is greater than 300,000, the resin solution viscosity becomes too high and coating becomes difficult. Moreover, in order to control the final molecular weight, it is also possible to synthesize by shifting the molar ratio of the tetracarboxylic dianhydride to be used and the diamine. The molar ratio of each unit polycondensate of general formula (1) and general formula (2) is general formula (1): general formula (2) = 1: 9 to 3: 1. More preferably, general formula (1): general formula (2) = 1: 3 to 3: 1. When the ratio of the structure of the general formula (1) is less than 10 mol%, a decrease in adhesive strength becomes a problem. When the ratio of the structure of the general formula (2) is less than 25 mol%, a decrease in solder heat resistance becomes a problem.

  The polymaleimide compound used in the resin layer of the resin composite copper foil used in the present invention is not particularly limited as long as it is a compound having two or more maleimide groups in one molecule. Preferred examples include 4,4′-diphenylmethane bismaleimide, polyphenylmethane maleimide, m-phenylene bismaleimide, bisphenol A diphenyl ether bismaleimide, 3,3′-dimethyl-5,5′-diethyl-4,4 ′. -Diphenylmethane bismaleimide can be mentioned, and one or two or more can be used in appropriate mixture. A prepolymer of a polymaleimide compound or a prepolymer of a polymaleimide compound and an amine compound can also be used. The content ratio of the block copolymerized polyimide and the bismaleimide compound in the resin layer of the resin composite copper foil is 10 to 90:90 to 10 and preferably 20 to 80:80 to 20 by weight.

  The copper foil used for the resin composite copper foil used in the present invention is not particularly limited as long as it is a known copper foil used for printed wiring boards, but preferably an electrolytic copper foil, a rolled copper foil, and these A copper alloy or the like is used. For example, nickel, cobalt treatment, or a known surface treatment such as a silane treatment agent may be used on these copper foils. The thickness of the copper foil is not particularly limited, but is preferably 35 μm or less. The surface roughness (Rz) of the copper foil surface forming the resin layer is preferably 4 μm or less, and more preferably 2 μm or less (Rz is the ten-point average roughness defined by JIS B0601. ).

  In the resin composite copper foil used in the present invention, the thickness of the resin layer can be adjusted according to the surface roughness level of the copper foil. Since drying in the subsequent heating step tends to be insufficient, and the heat resistance of the copper clad laminate used may be reduced, 0.1 μm to 10 μm is preferable, and 1 to 7 μm is more preferable.

  The resin composite copper foil used in the present invention is blended with one or more polymaleimide compounds in the polar solvent solution of the block copolymerized polyimide resin obtained by the above-described synthesis method, while room temperature or heating. It is prepared by dissolving with stirring, coating directly on one side of the copper foil, and drying. As a coating method, various methods such as a reverse roll, a rod (bar), a blade, a knife, a die, a gravure, and a rotary screen are possible. The drying is not particularly limited as long as it can apply a temperature sufficient to remove the solvent used, such as a hot air dryer or an infrared dryer.

  After apply | coating the solution of this block copolymerization polyimide resin and a polymaleimide compound to copper foil, it heats at the temperature of 250 to 360 degreeC, and makes resin composite copper foil. With heating at a lower temperature or higher temperature, the heat resistance of the resin composite copper foil after moisture absorption is significantly inferior. The resin film of the resin composite copper foil does not melt at a temperature of at least 200 ° C. and is excellent in heat resistance, flame resistance, and electrical insulation. In order to prevent copper oxidation, the heating is preferably performed at a higher temperature in a vacuum or in an inert atmosphere such as nitrogen.

  In the method for producing a printed wiring board of the present invention, the resin composition used for the B-stage resin composition layer that is laminated with the resin composite copper foil is a known thermosetting resin composition used for a printed wiring board. There is no particular limitation. Examples of these resins include epoxy resins, polyimide resins, cyanate ester resins, maleimide resins, double bond-added polyphenylene ether resins, and resin compositions such as bromine and phosphorus-containing compounds of these resins. Species or two or more are used in combination. From the viewpoint of reliability such as migration resistance and heat resistance, it is preferable to use a resin composition containing a cyanate ester resin as an essential component, for example, an epoxy resin. For these thermosetting resins, known catalysts, curing agents, and curing accelerators can be used as necessary.

  The cyanate ester resin suitably used for the resin composition used for the B-stage resin composition layer used in the present invention is a compound having two or more cyanato groups in the molecule. Specific examples include 1,3- or 1,4-dicyanatobenzene, 1,3,5-tricyanatobenzene, 1,3-, 1,4-, 1,6-, 1,8-, 2 , 6- or 2,7-dicyanatonaphthalene, 1,3,6-tricyanatonaphthalene, 4,4-dicyanatobiphenyl, bis (4-dicyanatophenyl) methane, 2,2-bis (4-cyanato Phenyl) propane, 2,2-bis (3,5-dibromo-4-cyanatophenyl) propane, bis (4-cyanatophenyl) ether, bis (4-cyanatophenyl) thioether, bis (4-cyanatophenyl) ) Sulfone, tris (4-cyanatophenyl) phosphite, tris (4-cyanatophenyl) phosphate, and cyanate ester resins obtained by reacting various novolak resins with cyanogen halides. These may be used alone or in combination of two or more.

  As an epoxy resin suitably used in combination with a cyanate ester resin, known resins can be used. Specifically, bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, alicyclic epoxy resin, biphenyl type epoxy resin, fluorene type epoxy resin, resorcin type epoxy resin, Naphthalene type epoxy resin, phenol aralkyl type epoxy resin, biphenyl aralkyl type epoxy resin, epoxidized polyphenylene ether resin; polyepoxy compounds epoxidized with double bond such as butadiene, pentadiene, vinylcyclohexene, dicyclopentyl ether; polyol, hydroxyl group Examples thereof include polyglycidyl compounds obtained by the reaction of containing silicon resins with epichlorohydrin. Moreover, these well-known bromine addition resin, phosphorus containing epoxy resin, etc. are mentioned. These may be used alone or in combination of two or more.

  The method for producing the B-stage resin composition layer used in the present invention is not particularly limited. For example, the thermosetting resin composition is dissolved / dispersed in a solvent or made into a varnish without a solvent and applied to one side of a release film. , A method of drying to form a B-stage resin composition sheet, a method of applying to a base material, a method of drying to form a B-stage to form a prepreg, and a B-stage resin composition by directly coating and drying on a substrate on which a conductor circuit is formed It is produced by a known method such as a method of forming a physical layer. The thickness of the B-stage resin composition layer is not particularly limited, but in the case of a sheet, it is preferably 4 to 150 μm, and the same applies when applied. In the case of a prepreg, the thickness is preferably 10 to 200 μm.

  In the B stage resin composition layer used in the present invention, it is preferable to use a base material from the characteristics of the obtained copper-clad laminate. As a base material to be used, if it is a well-known base material used for a printed wiring board, it will not specifically limit. Specific examples include generally known nonwoven fabrics and woven fabrics of glass fibers such as E, NE, D, S, and T glass. In order for these base materials to improve adhesiveness with a resin composition, it is preferable to perform well-known surface treatment to the base material.

  The manufacturing method of the copper clad laminated board in this invention arrange | positions the resin layer surface of the said resin composite copper foil facing the said B stage resin composition layer, and carries out lamination molding. Specifically, although a B-stage resin composition layer or a B-stage resin composition layer is disposed or formed on both surfaces of a laminate, at least one surface is disposed with the resin layer surface of the resin composite copper foil facing and heated. Then, lamination molding is performed under pressure, preferably under vacuum, to obtain a copper-clad laminate. When producing a multilayer board, a B-stage resin composition layer is disposed or formed on both surfaces of the inner substrate on which the conductor circuit is formed, and the resin layer surface of the resin composite copper foil is opposed to the B-stage resin composition layer surface. The multilayer copper-clad laminate is formed by heating and pressurizing, preferably under vacuum, and forming by lamination.

  The kind of the laminated board and circuit board used for these is not specifically limited, A well-known laminated board for printed wiring board materials, a metal foil tension board, Preferably a copper tension board can be used. Specifically, inorganic fiber and / or organic fiber-based copper-clad laminates, heat-resistant film-based copper-clad plates using thermosetting resin compositions and / or thermoplastic resin compositions, and further these Known materials such as composite base material copper clad laminates obtained by combining these base materials, multilayer copper clad plates, multilayer copper clad plates prepared by the additive method, and the like can be used. The conductor thickness of the circuit board is not particularly limited, but is preferably 3 to 35 μm. On this conductor circuit, it is preferable to perform a known process for improving the adhesion of the B-stage resin composition layer to the resin, for example, a black copper oxide process, a chemical solution process (for example, CZ process of MEC).

Lamination conditions during the production of the copper-clad laminate are not particularly limited. Preferably, lamination is performed at a temperature of 100 to 250 ° C., a pressure of 5 to 40 kgf / cm ² , and a degree of vacuum of 30 mmHg or less for 30 minutes to 5 hours. Lamination may be performed under these conditions from the beginning to the end, but it is also possible to laminate and form until gelation, and then take out and post-cure in a heating furnace.

  The method for producing a printed wiring board according to the present invention uses the copper-clad laminate, and first drills through holes and blind vias with a drill, a laser, etc., and if necessary, with permanganates. After the desmear process is performed to form a perforated copper-clad laminate, all the copper foil is removed by etching. The method for removing the etching is not particularly limited in the type of the etchant, and a known method can be applied.

  Next, electroless copper plating is performed without subjecting the resin layer surface of the laminated plate with the resin layer surface exposed to an uneven treatment. In general, in the method of manufacturing a printed wiring board in which a conductor layer is formed by copper plating, in order to ensure the adhesive force between the copper plating layer and the curable resin, the resin is etched with permanganate or the like, and the resin Although it is necessary to form unevenness on the surface, the present invention has a feature that does not require unevenness treatment. The electroless copper plating is performed by a known method. In general, a palladium catalyst is formed on the surface of the resin film, and subsequently immersed in an electroless copper plating solution to form a copper layer having a thickness of 0.5 to 2 μm. Next, electrolytic copper plating is performed on the entire surface to form a copper circuit that is firmly adhered by etching, or alternatively, electrolytic copper plating is selectively attached, and at least the thickness portion of the electroless copper plating layer is removed by etching. Thus, a firmly bonded copper circuit is formed. The thickness of the electrolytic copper plating is arbitrarily selected. At this time, in order to further improve the adhesive strength of the copper plating layer, heat treatment is performed at 100 ° C. to 200 ° C. after the formation of the electroless copper plating layer or the electrolytic copper plating layer. The heating time is not particularly limited, but is preferably selected from 30 minutes to 5 hours. In order not to oxidize the copper foil, heating in a vacuum or in an inert gas is preferable.

  The subsequent method for forming a copper circuit is performed in accordance with a known subtractive method or pattern plating method to obtain a printed wiring board. Specifically, in the case of pattern formation by the subtractive method, a portion of the copper plating layer on which the copper circuit is formed is covered with an etching resist, and the copper plating layer is selectively removed by a known etching method. A circuit pattern is formed to obtain a printed wiring board. In addition, when forming a pattern by the pattern plating method, after forming an electroless copper plating layer of about 0.5 to 1 μm, the area other than the place where the copper circuit is to be formed is selectively covered with a plating resist. After forming a copper plating layer of about 10 to 30 μm, the plating resist is peeled off, and at least an electroless copper plating layer on which no electrolytic copper plating layer is formed is etched to form a pattern to obtain a printed wiring board.

Hereinafter, the present invention will be specifically described with reference to synthesis examples, comparative synthesis examples, examples, and comparative examples.
(Synthesis example)
To a 2-liter three-necked flask equipped with a stainless steel vertical stirring bar, a trap equipped with a nitrogen inlet tube and a stopcock, and a reflux condenser equipped with a ball cooling tube, 3,4, 3 ', 4'-biphenyltetracarboxylic dianhydride 117.68 g (400 mmol), 1,3-bis (3-aminophenoxy) benzene 87.7 g (300 mmol), γ-valerolactone 4.0 g (40 mmol), pyridine 4.8 g (60 mmol) , N-methyl-2-pyrrolidone (hereinafter referred to as NMP) 300 g and toluene 20 g were added, heated at 180 ° C. for 1 hour, cooled to near room temperature, and then 3,4,3 ′, 4′-biphenyltetracarboxylic acid. Add 29.42 g (100 mmol) of dianhydride, 82.12 g (200 mmol) of 2,2-bis {4- (4-aminophenoxy) phenyl} propane, 200 g of NMP and 40 g of toluene, mix at room temperature for 1 hour, and then at 180 ° C. The block copolymer polyimide having a solid content of 38% was obtained by heating for 3 hours. The block copolymerized polyimide had general formula (1): general formula (2) = 3: 2, number average molecular weight: 70000, and weight average molecular weight: 150,000.

Examples 1-4
The block copolymerized polyimide solution obtained in the synthesis example was further diluted with NMP to obtain a block copolymerized polyimide solution having a solid content of 10%. In this block copolymerized polyimide solution, bis (4-maleimidophenyl) methane (BMI-H, Kei Ii Kasei) was dissolved and mixed at a solid content weight ratio shown in Table 1 at 60 ° C. for 20 minutes, respectively. After that, it was coated on the mat surface of 12μm thick electrolytic copper foil (F0-WS foil Rz = 1.5μm, manufactured by Furukawa Circuit Foil) using a reverse roll coating machine, and at 3O 0 C under nitrogen atmosphere. After 3 minutes of drying at 160 ° C. for 3 minutes, finally, heat treatment was performed at 300 ° C. for 2 minutes to produce a resin composite copper foil.

On the other hand, 400 g of 2,2-bis (4-cyanatophenyl) propane was melted at 150 ° C., reacted for 4 hours with stirring, dissolved in methyl ethyl ketone, and further brominated bisphenol A type epoxy resin (Epicron 1123P, Dainippon Ink) (600 g) and zinc octylate (0.1 part) were added to make a varnish. This varnish is impregnated into a glass woven fabric substrate with a thickness of 100 μm, dried at 150 ° C. for 6 minutes, a B-stage resin composition layer having a resin amount of 45%, a thickness of 105 μm, and a gelation time (at 170 ° C.) of 120 seconds. A (prepreg) was prepared. The upper and lower surfaces of the four prepregs are placed on the top and bottom surfaces of the resin composite copper foil facing each other, and laminated and molded for 1 hour at a temperature of 220 ° C, a pressure of 40 kgf / cm ² , and a degree of vacuum of 30 mmHg or less. A copper clad laminate having a thickness of 0.4 mm was produced. After drilling a hole with a diameter of 0.2 mm in these copper clad laminates, the copper foil was entirely removed with a hydrogen peroxide / sulfuric acid etching solution. Further, a 1 μm thick copper layer was formed with an electroless plating solution (Okuno Pharmaceutical Co., Ltd., ATS Adcopper CT), heated in a heating furnace at 130 ° C. for 2 hours, and then 1.5 ampere / dm 2 with a copper sulfate plating solution. Was subjected to electrolytic plating for 70 minutes to form a copper layer having a thickness of 20 μm. A 10 μm-thick etching resist film is attached to each laminated board on which the copper layer is formed, and after exposure and development, only a portion (34 μm wide linear shape) forming a copper circuit is covered with the etching resist, and then chlorinated. Etching was performed with a copper etchant, and the etching resist was peeled off to produce printed wiring boards each having a copper circuit with an average width of 25 μm. The evaluation results are shown in Table 1.

(Table 1) Evaluation results

Examples 5-8
In Examples 1 to 4, the steps up to forming a 1 μm thick copper layer with an electroless plating solution are performed in the same manner as in Examples 1 to 4, and then a 15 μm thick plating resist film is attached, exposed, and developed. Then, after coating the areas other than the copper circuit with a plating resist (resist remaining width 9 μm, resist groove width 15 μm), the plating resist is peeled off, and a copper sulfate plating solution is used at 1.5 ampere / dm ² . Electrolytic copper plating was performed for 50 minutes to form copper circuits having a thickness of 17 μm. Next, etching is performed with a hydrogen peroxide / sulfuric acid etchant (trade name CPE800, manufactured by Mitsubishi Gas Chemical) to form a circuit having a line width / line spacing of about 12/12 μm, and then heated in a heating furnace at 130 ° C. for 2 hours. Each printed wiring board was manufactured. The evaluation results are shown in Table 2.

Table 2 Evaluation results

Comparative Examples 1 and 2
A printed wiring board was produced in the same manner as in Examples 1 and 5 except that bismaleimide was not used in Examples 1 and 5. The evaluation results are shown in Table 3.

Table 3 Evaluation results

(Measuring method)
1) Overall thickness:
According to JIS C6481, the average value of the thickness of resin composite copper foil (size 500 x 500 mm) measured at five locations with a micrometer.
2) Copper plating adhesive strength:
Using a laminate of copper foil of 0.4 mm copper-clad laminate that has been etched on the entire surface, a full copper-plated layer laminate that has undergone electroless plating and electrolytic copper plating is prepared without forming a circuit. Similarly, the average value measured three times.
3) Hygroscopic heat resistance:
Cut the printed wiring board into 50mm x 50mm square, treat it at 121 ° C and 2 atm for a specified time with a prescher cooker tester (PC-3 type manufactured by Hirayama Seisakusho), then float it in a solder bath at 260 ° C for 60 seconds. The presence or absence of abnormal appearance changes was visually observed. (○: No abnormality, ×: Swelling and peeling occurred)

It is explanatory drawing of the copper clad laminated board used by this invention. It is explanatory drawing of the copper clad laminated board in which the through hole was formed. It is explanatory drawing of the laminated board which removed the copper foil and exposed the resin layer surface. It is explanatory drawing of the laminated board which formed the electroless copper plating layer in the resin layer surface. It is explanatory drawing of the laminated board which formed the electrolytic copper plating layer on the electroless copper plating layer. It is explanatory drawing of the printed wiring board which selectively removed the electroless copper plating layer and the electrolytic copper plating layer.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Copper foil 2 Resin layer 3 B stage resin composition layer 4 Through hole 5 Electroless copper plating layer 6 Electrolytic copper plating layer 7 Circuit

Claims (8)

A B-stage resin composition layer was laminated on the resin layer surface of the resin composite copper foil in which a resin layer containing a block copolymerized polyimide resin and a polymaleimide compound was formed on one side of the copper foil, and a copper-clad laminate was obtained by laminating and molding. After that, all the copper foil of the copper-clad laminate is removed by etching, the resin layer surface is exposed to form a laminate, and the electroless copper plating is performed by electroless copper plating without roughening the resin layer surface of the laminate. After forming an electrolytic copper plating layer on the electroless copper plating layer by electrolytic copper plating, the electroless copper plating layer and the electrolytic copper plating layer are selectively etched away to form a copper circuit. A printed wiring board manufacturing method. A B-stage resin composition layer was laminated on the resin layer surface of the resin composite copper foil in which a resin layer containing a block copolymerized polyimide resin and a polymaleimide compound was formed on one side of the copper foil, and a copper-clad laminate was obtained by laminating and molding. After that, all the copper foil of the copper-clad laminate is removed by etching, the resin layer surface is exposed to form a laminate, and the electroless copper plating is performed by electroless copper plating without roughening the resin layer surface of the laminate. After forming a layer and then selectively forming an electrolytic copper plating layer on the electroless copper plating layer, at least the electroless copper plating layer on which the electrolytic copper plating layer is not formed is removed by etching to form a copper circuit A printed wiring board manufacturing method. 3. The method of manufacturing a printed wiring board according to claim 1, wherein after the electroless plating layer or the electrolytic copper plating layer is formed, heat treatment is performed at 100 ° C. to 200 ° C. Production method. The method for producing a printed wiring board according to any one of claims 1 to 3, wherein the block copolymerized polyimide is a block copolymerized polyimide resin having structural units represented by the general formula (1) and the general formula (2). .

(M and n in the formula are integers satisfying m: n = 1: 9 to 3: 1) The method for producing a printed wiring board according to claim 1, wherein the resin composite copper foil is a resin composite copper foil having a resin layer thickness of 0.1 μm to 10 μm. 6. The resin composite copper foil according to claim 1, wherein a content ratio of the block copolymerized polyimide and the maleimide compound in the resin layer of the resin composite copper foil is 10 to 90:90 to 10 by weight. Manufacturing method of printed wiring board. After the resin composite copper foil is coated on one side of the copper foil with a resin solution containing the block copolymerized polyimide and the maleimide compound, it is subjected to a heat treatment step of 250 to 360 ° C. The method for producing a printed wiring board according to claim 1, wherein the resin composite copper foil has a resin layer that is not formed. The printed wiring board obtained by the manufacturing method of the printed wiring board in any one of Claims 1-7.

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