WO2022097481A1

WO2022097481A1 - Laminate for semi-additive manufacturing and printed wiring board using same

Info

Publication number: WO2022097481A1
Application number: PCT/JP2021/038869
Authority: WO
Inventors: 憲正深澤; 昭村川; 潤白髪
Original assignee: Dic株式会社
Priority date: 2020-11-05
Filing date: 2021-10-21
Publication date: 2022-05-12
Also published as: TW202233414A; JPWO2022097481A1

Abstract

The purpose of the present invention is to provide: a flat laminate for semi-additive manufacturing which is used for interfacial connection and exhibits a high degree of adhesion between a substrate and a conductor circuit without the use of a vacuum device and without requiring surface roughening by means of chromic acid or permanganic acid or requiring the formation of a surface modification layer by means of an alkali, said laminate making it possible to form wiring having a rectangular cross-sectional shape that is suitable for circuit wiring with little undercutting and good design reproducibility; and a printed wiring board using the same. The present invention is the result of the discovery that by using a method in which a through hole connecting the faces of a laminate obtained by laminating a conductive silver particle layer (M1) on both surfaces of an insulating substrate (A) is made conductive via the application of one of palladium, a conductive polymer and carbon, it is possible to form a printed wiring board having connected faces which exhibits a high degree of adhesion between a substrate and a conductor circuit, and has a rectangular cross-sectional shape that is suitable for circuit wiring with little undercutting and good design reproducibility.

Description

Laminated material for semi-additive construction method and printed wiring board using it

The present invention relates to a planar semi-additive method laminate used for electrically connecting both sides of a base material and a printed wiring board using the same.

The printed wiring board is a printed wiring board in which a metal layer of a circuit pattern is formed on the surface of an insulating base material. In recent years, with the demand for miniaturization and weight reduction of electronic device products, it is required to reduce the thickness of printed wiring boards (films) and to increase the definition of circuit wiring. Conventionally, as a method of manufacturing a circuit wiring, an etching resist having a circuit pattern shape is formed on the surface of a copper layer formed on an insulating base material, and the copper layer in a circuit-unnecessary part is etched to obtain the copper wiring. The subtractive method of forming has been widely used. However, in the subtractive method, copper at the hem of the wiring tends to remain, and when the distance between the wirings is shortened due to the high density of the circuit wiring, there are problems such as short circuit and poor insulation reliability between the wirings. In addition, if the etching is further advanced for the purpose of preventing a short circuit or improving the insulation reliability, the etching solution may wrap around the lower part of the resist, and as a result of the side etching, the wiring width direction may become narrower. It was a problem. In particular, when regions having different wiring densities coexist, there is a problem that the fine wiring existing in the region having a low wiring density disappears as the etching proceeds. Furthermore, the cross-sectional shape of the wiring obtained by the subtractive method is not rectangular, but has a trapezoidal shape or a triangular shape with a wide hem on the base material side. There was also a problem as a transmission line.

A semi-additive method has been proposed as a method for solving these problems and manufacturing a fine wiring circuit. In the semi-additive method, a conductive seed layer is formed on an insulating base material, and a plating resist is formed on a non-circuit forming portion on the seed layer. After forming the wiring portion by electrolytic plating through the conductive seed layer, the resist is peeled off and the seed layer of the non-circuit forming portion is removed to form the fine wiring. According to this method, since the plating is deposited along the shape of the resist, the cross-sectional shape of the wiring can be made rectangular, and the wiring of the desired width can be deposited regardless of the density of the pattern. Since it can be formed, it is suitable for forming fine wiring.

In the semi-additive method, a method of forming a conductive seed layer on an insulating base material by electroless copper plating using a palladium catalyst or electroless nickel plating is known. In these methods, for example, when a build-up film is used, the surface of the substrate is roughened using a strong chemical such as permanganic acid, which is called desmear roughening, in order to ensure the adhesion between the film substrate and the copper-plated film. By forming a plating film from the formed voids, the anchor effect is utilized to ensure the adhesion between the insulating base material and the plating film. However, if the surface of the base material is roughened, it becomes difficult to form fine wiring, and there are problems such as deterioration of high frequency transmission characteristics. Therefore, it has been considered to reduce the degree of roughening, but in the case of low roughening, there is a problem that the required adhesion strength between the formed wiring and the base material cannot be obtained.

On the other hand, a technique of forming electroless nickel plating on a polyimide film to form a conductive seed is also known. In this case, by immersing the polyimide film in strong alkali, the imide ring of the surface layer is opened to make the film surface hydrophilic, and at the same time, a modified layer in which water permeates is formed, and the modified layer is contained. A palladium catalyst is impregnated into the film and electroless nickel plating is performed to form a nickel seed layer (see, for example, Patent Document 1). In this technique, the adhesion strength is obtained by forming nickel plating from the modified layer of the outermost polyimide layer, but since the modified layer is in a state where the imide ring is opened, the film surface layer. There was a problem that the structure was physically and chemically weak.

On the other hand, as a method of surface roughening or not forming a modified layer on the surface layer, a method of forming a conductive seed such as nickel or titanium on an insulating base material by a sputtering method is also known (for example). , Patent Document 2). This method can form a seed layer without roughening the surface of the substrate, but it requires the use of expensive vacuum equipment, a large initial investment, and the size and shape of the substrate. The problems were that there were restrictions and that the process was complicated with low productivity.

As a method for solving the problem of the sputtering method, a method of using a coating layer of a conductive ink containing metal particles as a conductive seed layer has been proposed (see, for example, Patent Document 3). In this technique, the above-mentioned coating is performed by applying a conductive ink in which metal particles having a particle diameter of 1 to 500 nm are dispersed on an insulating base material made of a film or a sheet, and performing a heat treatment. A technique is disclosed in which metal particles in a conductive ink are fixed as a metal layer on an insulating base material to form a conductive seed layer, and further, plating is performed on the conductive seed layer.

In Patent Document 3, pattern formation by a semi-additive method is proposed, and in an embodiment, a conductive ink in which copper particles are dispersed is applied and heat-treated to form a copper conductive seed layer. Using the material as a base material for the semi-additive method, a photosensitive resist is formed on the conductive seed layer, exposed and developed, the pattern-forming part is thickened by electrolytic copper plating, the resist is peeled off, and then copper is used. It is described that the conductive seed layer of the above is removed by etching. Further, in the case of forming a printed wiring board by the semi-additive method, which has been studied conventionally, a thin copper foil or a base material provided with a copper plating film as a conductive seed on an insulating base material is semi-additive. It is used as a base material for construction methods.
In this way, when the conductive seed layer and the conductive layer of the circuit pattern are formed of the same metal as in the combination of the conductive seed layer of copper and the circuit pattern of copper, the conductive seed layer of the non-pattern forming portion is formed. It is known that the conductive layer of the circuit pattern is also etched at the same time when the circuit pattern is removed, so that the circuit pattern becomes thinner and thinner, and the surface roughness of the circuit conductive layer also increases. It was a problem to be solved in manufacturing wiring for high frequency transmission.
To solve these problems, the present inventors have used a substrate in which a conductive silver particle layer is formed on the surface of an insulating substrate as a substrate for a semi-additive method in a seed layer etching step. Invented a technique for forming a printed wiring board having a smooth circuit layer surface with good design reproducibility without thinning of the circuit pattern or thinning. (Non-Patent Documents 1 and 2)
The technique can form circuits on both sides as well as on one side, but has conductive silver particle layers on both sides of the insulating substrate to connect the circuits on both sides. When holes are formed in the base material for the semi-additive method and double-sided connection is performed, when the double-sided electrical connection process by the conventional electrolytic copper plating method is performed, copper plating is performed on the silver particle layer (M1). As the film is formed, the conductive seed layer for forming the circuit pattern becomes a copper layer, which causes problems such as thinning of the circuit pattern and thinning of the circuit pattern in the seed layer etching step as described above. ..

International Publication No. 2009/004774 Japanese Unexamined Patent Publication No. 9-136378 Japanese Unexamined Patent Publication No. 2010-272837

The problem to be solved by the present invention is that it does not require surface roughening with chromium acid or permanganic acid, formation of a surface modification layer with alkali, etc., and high adhesion between the substrate and the conductor circuit without using a vacuum device. A planar semi-additive method laminate for double-sided connection that can form wiring with good properties, less undercut, good design reproducibility, and a good rectangular cross-sectional shape as circuit wiring, and printing using it. It is to provide a wiring board.

As a result of diligent research to solve the above problems, the present inventors connect both sides of a laminated body in which a conductive silver particle layer (M1) is laminated on both surfaces of an insulating base material (A). By using a method of imparting either palladium, a conductive polymer, or carbon to make the through hole conductive, complicated surface roughening and formation of a surface-modified layer are not required, and a vacuum device is not used. Found that it is possible to form a printed wiring board connected on both sides, which has high adhesion between the base material and the conductor circuit, has less undercut, has good design reproducibility, and has a good rectangular cross-sectional shape for circuit wiring. , The present invention has been completed.

That is, the present invention
1. 1. Step 1, in which through holes penetrating both sides are formed in a laminate having a conductive silver particle layer (M1) on both surfaces of the insulating base material (A).
Step 2, in which either palladium, a conductive polymer, or carbon is applied onto the surface of the silver particle layer (M1) and the base material having through holes to make the through hole surface conductive.
Step 3, in which any one of palladium, the conductive polymer, and carbon applied on the silver particle layer (M1) is removed to expose only the conductive silver particle layer (M1').
Step 4 of forming a pattern resist on the conductive silver particle layer (M1').
Step 5, in which both sides of the base material and the surface of the through hole are electrically connected by electrolytic copper plating and a circuit pattern layer (M2) is formed.
A method for manufacturing a printed wiring board, which comprises.

2. 2. 1. The method for manufacturing a printed wiring board according to 1, wherein a laminate having a primer layer (B) is used between the insulating base material (A) and the silver particle layer (M1).

3. 3. The method for manufacturing a printed wiring board according to 1 or 2, wherein the silver particles constituting the silver particle layer (M1) are coated with a polymer dispersant.

4. In the laminate for the semi-additive method according to claim 2, the primer layer (B) is a layer composed of a resin having a reactive functional group [X], and the polymer dispersant is a reactive functional group [Y]. ], And the reactive functional group [X] and the reactive functional group [Y] can form a bond with each other by a reaction. 3. The method for producing a printed wiring board according to 3.

5. 4. The method for producing a printed wiring board according to 4, wherein the reactive functional group [Y] is a basic nitrogen atom-containing group.

6. 5. The print according to 5 in which the polymer dispersant having the reactive functional group [Y] is at least one selected from the group consisting of polyalkyleneimine and polyalkyleneimine having a polyoxyalkylene structure containing an oxyethylene unit. Manufacturing method of wiring board.

7. The reactive functional group [X] is selected from the group consisting of a keto group, an acetoacetyl group, an epoxy group, a carboxyl group, an N-alkyrole group, an isocyanate group, a vinyl group, a (meth) acryloyl group and an allyl group1 The present invention provides the method for manufacturing a printed wiring board according to any one of 4 to 6 which is more than a seed.

By using the method for manufacturing a printed wiring board of the present invention, both sides having a circuit wiring having a good rectangular cross-sectional shape having a smooth surface with high adhesion on various smooth substrates without using a vacuum device. It is possible to manufacture the connected printed wiring board with good design reproducibility. Therefore, by using the technique of the present invention, it is possible to provide a multi-layered high-density, high-performance, high-frequency transmission compatible printed wiring board at low cost, and it can be used industrially in the field of printed wiring. High quality. Further, the printed wiring board manufactured by using the laminate for the semi-additive method of the present invention is used not only for a normal printed wiring board but also for various electronic members having a patterned metal layer on the surface of the base material. For example, it can be applied to connectors, electromagnetic wave shields, antennas such as RFID, film capacitors, and the like.

FIG. 1 is a process diagram for manufacturing a printed wiring board using a laminate for a semi-additive method.

In the method for manufacturing a printed wiring board of the present invention, through holes penetrating both sides are formed in a laminate having a conductive silver particle layer (M1) on both surfaces of an insulating base material (A), and palladium is used. , Conductive polymer or carbon is applied to make it conductive, and then electrolytic copper plating is used to electrically connect both sides of the substrate and the surface of the through holes, and to form a circuit pattern. be.

Further, in the method for producing a printed wiring board according to a more preferable aspect of the present invention, a primer layer (B) is further provided between the insulating base material layer (A) and the conductive silver particle layer (M1). It is characterized by.

Examples of the material of the insulating base material (A) include polyimide resin, polyamideimide resin, polyamide resin, polyethylene terephthalate resin, polybutylene terephthalate resin, polyethylene naphthalate resin, polycarbonate resin, and acrylonitrile-butadiene-styrene (ABS). Acrylic resin such as resin, polyarylate resin, polyacetal resin, poly (meth) methyl acrylate, polyfluorovinylidene resin, polytetrafluoroethylene resin, polyvinyl chloride resin, polyvinylidene chloride resin, and acrylic resin were graft-copolymerized. Vinyl chloride resin, polyvinyl alcohol resin, polyethylene resin, polypropylene resin, urethane resin, cycloolefin resin, polystyrene, liquid crystal polymer (LCP), polyether ether ketone (PEEK) resin, polyphenylene sulfide (PPS), polyphenylene sulfone (PPSU), Examples thereof include cellulose nanofibers, silicon, silicon carbide, gallium nitride, sapphire, ceramics, glass, diamond-like carbon (DLC), alumina and the like.

Further, as the insulating base material (A), a resin base material containing a thermosetting resin and an inorganic filler can be preferably used. Examples of the thermosetting resin include epoxy resin, phenol resin, unsaturated imide resin, cyanate resin, isocyanate resin, benzoxazine resin, oxetane resin, amino resin, unsaturated polyester resin, allyl resin, and dicyclopentadiene resin. Examples thereof include silicone resin, triazine resin, and melamine resin. On the other hand, examples of the inorganic filler include silica, alumina, talc, mica, aluminum hydroxide, magnesium hydroxide, calcium carbonate, aluminum borate, and glass borate. These thermosetting resins and inorganic fillers can be used alone or in combination of two or more.

As the form of the insulating base material (A), any of a flat flexible material, a rigid material, and a rigid flexible material can be used. More specifically, a film, a sheet, or a commercially available material molded into a plate may be used for the insulating base material (A), or the above-mentioned resin solution, melt liquid, or dispersion liquid may be made flat. A molded material may be used. Further, the insulating base material (A) may be a base material having the above-mentioned resin material formed on a conductive material such as metal, and may be placed on a printed wiring board on which a circuit pattern is formed. , A base material obtained by laminating and forming the above-mentioned resin material may be used.

The silver particle layer (M1) is a plating base layer when a circuit pattern layer (M2) described later is formed by a plating step when a printed wiring board is manufactured by using the laminated body for a printed wiring board of the present invention. Will be.

The silver particles constituting the silver particle layer (M1) can contain metal particles other than silver as long as the plating step described later can be carried out without any problem, but the proportion of the metal particles other than silver will be described later. 5 parts by mass or less is preferable with respect to 100 parts by mass of silver, and 2 parts by mass or less is more preferable, because the etching removability of the non-circuit forming portion can be further improved.

As a method of forming the silver particle layer (M1) on both sides of the planar insulating base material (A), for example, a silver particle dispersion liquid is applied to both sides of the insulating base material (A). There is a method of construction. The coating method of the silver particle dispersion liquid is not particularly limited as long as the silver particle layer (M1) can be formed satisfactorily, and various coating methods can be used depending on the shape, size, and rigidity of the insulating base material (A). It may be selected appropriately depending on the degree and the like. Specific coating methods include, for example, a gravure method, an offset method, a flexographic method, a pad printing method, a gravure offset method, a letterpress method, a letterpress inversion method, a screen method, a microcontact method, a reverse method, and an air doctor coater method. Blade coater method, air knife coater method, squeeze coater method, impregnation coater method, transfer roll coater method, kiss coater method, cast coater method, spray coater method, inkjet method, die coater method, spin coater method, bar coater method, dip coater method. And so on. At this time, the silver particle layer (M1) may be simultaneously formed on both surfaces of the insulating base material (A), or may be formed on one side of the insulating base material (A) and then on the other side. It may be formed.

The insulating base material (A) and the primer layer (B) formed on the insulating base material (A) are used to improve the coatability of the silver particle dispersion liquid and to form a circuit pattern layer (a circuit pattern layer) formed in the plating step. For the purpose of improving the adhesion of M2) to the substrate, surface treatment may be performed before applying the silver particle dispersion liquid. The surface treatment method for the insulating base material (A) is not particularly limited as long as the surface roughness becomes large and the fine pitch pattern formability and the signal transmission loss due to the rough surface do not become a problem, and various methods are used. Should be selected as appropriate. Examples of such a surface treatment method include UV treatment, vapor phase ozone treatment, liquid layer ozone treatment, corona treatment, plasma treatment and the like. These surface treatment methods may be carried out by one kind of method or a combination of two or more kinds of methods.

After applying the silver particle dispersion liquid on the insulating base material (A) or the primer layer (B), the coating film is dried to volatilize the solvent contained in the silver particle dispersion liquid. The silver particle layer (M1) is formed on the insulating base material (A) or on the primer layer (B).

The above-mentioned drying temperature and time may be appropriately selected depending on the heat-resistant temperature of the base material to be used and the type of the solvent used for the metal particle dispersion liquid described later, but the time may be in the range of 20 to 350 ° C. The range of 1 to 200 minutes is preferable. Further, in order to form the silver particle layer (M1) having excellent adhesion on the substrate, the drying temperature is more preferably in the range of 0 to 250 ° C.

The insulating base material (A) on which the silver particle layer (M1) is formed or the insulating base material (A) on which the primer layer (B) is formed is, if necessary, after the above-mentioned drying, the silver particles. Further annealing is performed for the purpose of reducing the electrical resistance of the layer and for the purpose of improving the adhesion between the insulating base material (A) or the primer layer (B) and the silver particle layer (M1). May be good. The annealing temperature and time may be appropriately selected according to the heat resistant temperature of the substrate to be used, the required electrical resistance, productivity, etc., and may be performed in the range of 60 to 350 ° C. for 1 minute to 2 weeks. .. Further, in the temperature range of 60 to 180 ° C., the time is preferably 1 minute to 2 weeks, and in the range of 180 to 350 ° C., it is preferably about 1 minute to 5 hours.

The above drying may be performed by blowing air, or may not be blown in particular. Further, the drying may be carried out in the atmosphere, under a substitution atmosphere of an inert gas such as nitrogen or argon, under an air flow, or under a vacuum.

Drying of the coating film can be performed in a dryer such as a blower or a constant temperature dryer, in addition to natural drying at the coating site. When the insulating base material (A) is a roll film or a roll sheet, the roll material is dried by continuously moving the roll material in an installed non-heated or heated space following the coating process. -Can be fired. Examples of the heating method for drying / firing at this time include a method using an oven, a hot air drying furnace, an infrared drying furnace, laser irradiation, microwaves, light irradiation (flash irradiation device), and the like. These heating methods can be used alone or in combination of two or more.

The amount of the metal particle layer (M1) formed on the insulating base material (A) or the primer layer (B) is preferably in the range of 0.01 to 30 g / m ² , preferably 0.01. The range of ~ 10 g / m ² is more preferable. Further, the range of 0.05 to 5 g / m ² is more preferable because the formation of the conductive layer (M3) by the plating step described later becomes easy and the seed layer removal step by etching described later becomes easy.

The amount of the silver particle layer (M1) formed can be confirmed by using a known and commonly used analytical method such as a fluorescent X-ray method, an atomic absorption method, and an ICP method.

Further, in the step of exposing the circuit pattern to the resist layer described later with active light, the silver particle layer (M1) can be formed for the purpose of suppressing reflection of the active light from the silver particle layer (M1), which will be described later. Graphite, carbon, cyanine compound, phthalocyanine compound, dithiol metal complex, naphthoquinone compound that absorbs the active light in the silver particle layer (M1) to the extent that electrolytic plating can be performed without problems and the etching removability described later can be ensured. , Diimmonium compound, azo compound and other light-absorbing pigments, or dyes may be contained as a light absorber. These pigments and dyes may be appropriately selected according to the wavelength of the active light to be used. Further, these pigments and dyes can be used alone or in combination of two or more. Further, in order to contain these pigments and dyes in the silver particle layer (M1), these pigments and dyes may be blended in the silver particle dispersion liquid described later.

The silver particle dispersion liquid used to form the silver particle layer (M1) is one in which silver particles are dispersed in a solvent. The shape of the silver particles is not particularly limited as long as it can form the silver particle layer (M1) satisfactorily, and has various shapes such as spherical, lenticular, polyhedral, flat plate, rod, and wire. Silver particles can be used. These silver particles may be used as one type having a single shape, or may be used in combination with two or more types having different shapes.

When the shape of the silver particles is spherical or polyhedral, it is preferable that the average particle diameter is in the range of 1 to 20,000 nm. Further, when a fine circuit pattern is formed, the homogeneity of the silver particle layer (M1) is further improved, and the removability by an etching solution described later can be further improved, so that the average particle diameter is in the range of 1 to 200 nm. Those in the range of 1 to 50 nm are more preferable, and those in the range of 1 to 50 nm are further preferable. The "average particle size" of the nanometer-sized particles is a volume average value measured by a dynamic light scattering method obtained by diluting the metal particles with a good dispersion solvent. "Nanotrack UPA-150" manufactured by Microtrack Co., Ltd. can be used for this measurement.

On the other hand, when the silver particles have a shape such as a lens shape, a rod shape, or a wire shape, those having a minor axis in the range of 1 to 200 nm are preferable, those having a minor axis in the range of 2 to 100 nm are more preferable, and those having a minor diameter in the range of 5 to 50 nm are more preferable. Those in the range of are more preferable.

The silver particles preferably contain silver particles as a main component, but the silver particles are described above as long as they do not interfere with the plating step described later or impair the removability of the silver particle layer (M1) described later by the etching solution. A part of silver constituting the silver particles may be replaced with another metal, or a metal component other than silver may be mixed.

Examples of the metal to be substituted or mixed include one or more metal elements selected from the group consisting of gold, platinum, palladium, ruthenium, tin, copper, nickel, iron, cobalt, titanium, indium and iridium.

The ratio of the metal to be substituted or mixed with respect to the silver particles is preferably 5% by mass or less in the silver particles, and is 2% by mass from the viewpoint of the plating property of the silver particle layer (M1) and the removability by the etching solution. % Or less is more preferable.

The silver particle dispersion used to form the silver particle layer (M1) is one in which silver particles are dispersed in various solvents, and the particle size distribution of the silver particles in the dispersion is uniform in a single dispersion. It may be a mixture of particles within the above average particle size range.

As the solvent used for the dispersion liquid of the silver particles, an aqueous medium or an organic solvent can be used. Examples of the aqueous medium include distilled water, ion-exchanged water, pure water, ultrapure water, and a mixture of the water and an organic solvent to be mixed with the water.

Examples of the organic solvent to be mixed with water include alcohol solvents such as methanol, ethanol, n-propanol, isopropanol, ethyl carbitol, ethyl cellosolve and butyl cellosolve; ketone solvents such as acetone and methyl ethyl ketone; ethylene glycol, diethylene glycol and propylene. Examples thereof include an alkylene glycol solvent such as glycol; a polyalkylene glycol solvent such as polyethylene glycol, polypropylene glycol and polytetramethylene glycol; and a lactam solvent such as N-methyl-2-pyrrolidone.
In addition, examples of the organic solvent when the organic solvent is used alone include alcohol compounds, ether compounds, ester compounds, and ketone compounds.

Examples of the alcohol solvent or ether solvent include methanol, ethanol, n-propanol, isopropyl alcohol, n-butanol, isobutyl alcohol, sec-butanol, tert-butanol, heptanol, hexanol, octanol, nonanol, decanol, undecanol, and dodecanol. , Tridecanol, Tetradecanol, Pentadecanol, Stearyl Alcohol, Allyl Alcohol, Cyclohexanol, Terpineol, Tarpineol, Dihydroterpineol, 2-Ethyl-1,3-hexanediol, Ethylene Glycol, Diethylene Glycol, Triethylene Glycol, Polyethylene Glycol, Propylene glycol, dipropylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, glycerin, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol Monobutyl Ether, Diethylene Glycol Monoethyl Ether, Diethylene Glycol Monomethyl Ether, Diethylene Glycol Monobutyl Ether, Tetraethylene Glycol Monobutyl Ether, Propylene Glycol Monomethyl Ether, Dipropylene Glycol Monomethyl Ether, Tripropylene Glycol Monomethyl Ether, Propylene Glycol Monopropyl Ether, Dipropylene Glycol Monopropyl Examples thereof include ether, propylene glycol monobutyl ether, dipropylene glycol monobutyl ether, and tripropylene glycol monobutyl ether.

Examples of the ketone solvent include acetone, cyclohexanone, methyl ethyl ketone and the like. Examples of the ester solvent include ethyl acetate, butyl acetate, 3-methoxybutyl acetate, 3-methoxy-3-methyl-butyl acetate and the like. Further, as another organic solvent, a hydrocarbon solvent such as toluene, particularly a hydrocarbon solvent having 8 or more carbon atoms can be mentioned.

Examples of the hydrocarbon solvent having 8 or more carbon atoms include non-polar solvents such as octane, nonane, decane, dodecane, tridecane, tetradecane, cyclooctane, xylene, mesitylene, ethylbenzene, dodecylbenzene, tetraline, and trimethylbenzenecyclohexane. It can be used in combination with other solvents as needed. Further, a solvent such as mineral spirit or solvent naphtha which is a mixed solvent can be used in combination.

In the solvent, the silver particles are stably dispersed, and the silver particle layer is placed on the insulating base material (A) or the primer layer (B) formed on the insulating base material (A) described later. There is no particular limitation as long as it forms (M1) well. Further, the solvent may be used alone or in combination of two or more.

The content of silver particles in the silver particle dispersion is such that the amount of the silver particle layer (M1) formed on the insulating substrate (A) is 0.01 to 30 g by using the various coating methods described above. It may be adjusted appropriately so as to be in the range of / m ² , and adjusted so as to have a viscosity having optimum coating suitability according to the above-mentioned various coating methods, but in the range of 0.1 to 50% by mass. Is preferable, and the range of 0.5 to 20% by mass is more preferable.

In the silver particle dispersion liquid, it is preferable that the silver particles do not aggregate, fuse, or precipitate in the various solvent media, and the dispersion stability is maintained for a long period of time, and the silver particles are dispersed in the various solvents. It is preferable to contain a dispersant for causing the reaction. As such a dispersant, a dispersant having a functional group that coordinates with the metal particles is preferable, and for example, a carboxyl group, an amino group, a cyano group, an acetoacetyl group, a phosphorus atom-containing group, a thiol group, a thiosianato group, and a glycinato. Dispersants having a functional group such as a group can be mentioned.

As the dispersant, a commercially available or independently synthesized low molecular weight or high molecular weight dispersant can be used, and the insulating base material to which a solvent for dispersing metal particles or a dispersion liquid of metal particles is applied is applied. It may be appropriately selected according to the purpose such as the type of (A). For example, dodecanethiol, 1-octanethiol, triphenylphosphine, dodecylamine, polyethylene glycol, polyvinylpyrrolidone, polyethyleneimine, polyvinylpyrrolidone; fatty acids such as myristic acid, octanoic acid and stearic acid; A polycyclic hydrocarbon compound having a carboxyl group of the above is preferably used. Here, when the silver particle layer (M1) is formed on the primer layer (B) described later, the adhesion between these two layers becomes good, so that the reaction of the resin used for the primer layer (B) described later It is preferable to use a compound having a reactive functional group [Y] capable of forming a bond with the sex functional group [X].

Examples of the compound having a reactive functional group [Y] include an amino group, an amide group, an alkyrole amide group, a carboxyl group, an anhydrous carboxyl group, a carbonyl group, an acetoacetyl group, an epoxy group, an alicyclic epoxy group and an oxetan ring. , Vinyl group, allyl group, (meth) acryloyl group, (blocked) isocyanate group, (alkoxy) silyl group and the like, silsesquioxane compound and the like. In particular, the reactive functional group [Y] is preferably a basic nitrogen atom-containing group because the adhesion between the primer layer (B) and the metal particle layer (M1) can be further improved. Examples of the basic nitrogen atom-containing group include an imino group, a primary amino group, a secondary amino group and the like.

The basic nitrogen atom-containing group may be singular or plural in one molecule of the dispersant. By containing a plurality of basic nitrogen atoms in the dispersant, some of the basic nitrogen atom-containing groups contribute to the dispersion stability of the metal particles by interacting with the metal particles, and the remaining basic nitrogen. The atom-containing group contributes to improving the adhesion to the insulating base material (A). Further, when a resin having a reactive functional group [X] is used for the primer layer (B) described later, the basic nitrogen atom-containing group in the dispersant is between the reactive functional group [X]. It is preferable because a bond can be formed with the above and the adhesion of the metal pattern layer (M2) described later on the insulating base material (A) can be further improved.

Since the dispersant can form a silver particle layer (M1) that exhibits stability, coatability, and good adhesion on the insulating base material (A), the dispersant is a dispersant. , The polymer dispersant is preferable, and as the polymer dispersant, polyalkyleneimine such as polyethyleneimine and polypropyleneimine, and a compound in which polyoxyalkylene is added to the polyalkyleneimine are preferable.

The compound to which polyoxyalkylene is added to the polyalkyleneimine may be a compound in which polyethyleneimine and polyoxyalkylene are bonded in a linear manner, and the side of the main chain made of polyethyleneimine is the side thereof. The chain may be grafted with polyoxyalkylene.

Specific examples of the compound in which polyoxyalkylene is added to the polyalkyleneimine include a block copolymer of polyethyleneimine and polyoxyethylene, and ethylene oxide in a part of the imino group present in the main chain of polyethyleneimine. Examples thereof include those in which a polyoxyethylene structure is introduced by an addition reaction, and those in which an amino group possessed by polyalkyleneimine, a hydroxyl group possessed by polyoxyethylene glycol, and an epoxy group possessed by an epoxy resin are reacted.

Examples of the commercially available product of the polyalkyleneimine include "PAO2006W", "PAO306", "PAO318" and "PAO718" of "Epomin (registered trademark) PAO series" manufactured by Nippon Shokubai Co., Ltd.

The number average molecular weight of the polyalkyleneimine is preferably in the range of 3,000 to 30,000.

The amount of the dispersant required to disperse the silver particles is preferably in the range of 0.01 to 50 parts by mass with respect to 100 parts by mass of the silver particles, and is on the insulating substrate (A). Alternatively, since a silver particle layer (M1) showing good adhesion can be formed on the primer layer (B) described later, the range of 0.1 to 10 parts by mass is preferable with respect to 100 parts by mass of the silver particles. Further, since the plating property of the silver particle layer (M1) can be improved, the range of 0.1 to 5 parts by mass is more preferable.

The method for producing the dispersion liquid of silver particles is not particularly limited and can be produced by using various methods. For example, silver particles produced by a gas phase method such as an evaporation method in a low vacuum gas can be used as a solvent. It may be dispersed therein, or the silver compound may be reduced in the liquid phase to directly prepare a dispersion of silver particles. In both the gas phase and the liquid phase methods, the solvent composition of the dispersion liquid at the time of production and the dispersion liquid at the time of coating can be changed as appropriate by exchanging the solvent or adding a solvent. Of the gas phase and liquid phase methods, the liquid phase method can be particularly preferably used because of the stability of the dispersion liquid and the simplicity of the manufacturing process. As a liquid phase method, for example, it can be produced by reducing silver ions in the presence of the polymer dispersant.

If necessary, the dispersion liquid of silver particles may further contain an organic compound such as a surfactant, a leveling agent, a viscosity modifier, a film forming aid, an antifoaming agent, and an antiseptic.

Examples of the surfactant include nonions such as polyoxyethylene nonylphenyl ether, polyoxyethylene lauryl ether, polyoxyethylene styrylphenyl ether, polyoxyethylene sorbitol tetraoleate, and polyoxyethylene / polyoxypropylene copolymer. Surfactants; fatty acid salts such as sodium oleate, alkyl sulfate ester salts, alkylbenzene sulfonates, alkyl sulfosuccinates, naphthalene sulfonates, polyoxyethylene alkyl sulfates, alkane sulfonate sodium salts, sodium alkyldiphenyl ether sulfonates Anionic surfactants such as salts; cationic surfactants such as alkylamine salts, alkyltrimethylammonium salts, and alkyldimethylbenzylammonium salts can be mentioned.

As the leveling agent, a general leveling agent can be used, and examples thereof include silicone-based compounds, acetylenediol-based compounds, and fluorine-based compounds.

As the viscosity modifier, a general thickener can be used. For example, an acrylic polymer that can be thickened by adjusting it to alkaline, a synthetic rubber latex, and a thickening agent by associating molecules can be used. Examples thereof include urethane resin, hydroxyethyl cellulose, carboxymethyl cellulose, methyl cellulose, polyvinyl alcohol, water-added castor oil, amido wax, polyethylene oxide, metal soap, and dibenzylidene sorbitol.

As the film-forming auxiliary, a general film-forming auxiliary can be used. For example, an anionic surfactant such as dioctyl sulfosuccinate sodium salt, a hydrophobic nonionic surfactant such as sorbitan monooleate, etc. can be used. , Polyether-modified siloxane, silicone oil and the like.

As the defoaming agent, a general defoaming agent can be used, and examples thereof include silicone-based defoaming agents, nonionic-based surfactants, polyethers, higher alcohols, and polymer-based surfactants.

As the preservative, a general preservative can be used, for example, an isothiazoline-based preservative, a triazine-based preservative, an imidazole-based preservative, a pyridine-based preservative, an azole-based preservative, a pyrithione-based preservative, and the like. Can be mentioned.

Further, as a more preferable embodiment of the laminate for the semi-additive method of the present invention, a laminate having a primer layer (B) between the insulating base material layer (A) and the conductive silver particle layer (M1). I can raise my body. The laminate for the semi-additive method provided with this primer layer is preferable because the adhesion of the conductive layer (M3) to the insulating base material (A) can be further improved.

The primer layer (B) is coated with a primer on a part or the entire surface of the insulating base material (A) to remove solvents such as an aqueous medium and an organic solvent contained in the primer. Can be formed. Here, the primer is used for the purpose of improving the adhesion of the conductive layer (M3) to the insulating base material (A), and is a liquid in which various resins described later are dissolved or dispersed in a solvent. It is a composition.

The method of applying the primer to the insulating base material (A) is not particularly limited as long as the primer layer (B) can be formed well, and various coating methods can be used for the insulating base material (A). It may be appropriately selected according to the shape, size, degree of flexibility and the like. Specific coating methods include, for example, a gravure method, an offset method, a flexographic method, a pad printing method, a gravure offset method, a letterpress method, a letterpress inversion method, a screen method, a microcontact method, a reverse method, and an air doctor coater method. Blade coater method, air knife coater method, squeeze coater method, impregnation coater method, transfer roll coater method, kiss coater method, cast coater method, spray coater method, inkjet method, die coater method, spin coater method, bar coater method, dip coater method. And so on.

Further, the method of applying the primer to both surfaces of the film, the sheet, and the plate-shaped insulating base material (A) is not particularly limited as long as the primer layer (B) can be formed well, and the coating illustrated above is exemplified. The construction method may be selected as appropriate. At this time, the primer layer (B) may be simultaneously formed on both surfaces of the insulating base material (A), and may be formed on one side of the insulating base material (A) and then on the other side. You may.

The insulating base material (A) may be surface-treated before the primer coating for the purpose of improving the coatability of the primer and improving the adhesion of the circuit pattern layer (M2) to the base material. good. As the surface treatment method for the insulating base material (A), the same method as the surface treatment method for forming the silver particle layer (M1) on the insulating base material (A) described above can be used. ..

As a method of applying the primer to the surface of the insulating base material (A) and then removing the solvent contained in the coating layer to form the primer layer (B), for example, drying using a dryer is used. The method of volatilizing the solvent is common. The drying temperature may be set to a temperature within a range in which the solvent can be volatilized and does not adversely affect the insulating base material (A), and may be room temperature drying or heat drying. The specific drying temperature is preferably in the range of 20 to 350 ° C, more preferably in the range of 60 to 300 ° C. The drying time is preferably in the range of 1 to 200 minutes, more preferably in the range of 1 to 60 minutes.

The above drying may be performed by blowing air, or may not be blown in particular. Further, the drying may be carried out in the atmosphere, in a substitution atmosphere such as nitrogen or argon, in an air flow, or in a vacuum.

When the insulating base material (A) is a single-leaf film, sheet, or board, it can be naturally dried at the coating site, blown air, or in a dryer such as a constant temperature dryer. When the insulating base material (A) is a roll film or a roll sheet, the roll material is dried by continuously moving the roll material in the installed non-heated or heated space following the coating process. It can be performed.

The film thickness of the primer layer (B) may be appropriately selected depending on the specifications and applications of the printed wiring board manufactured using the present invention, but the insulating base material (A) and the metal pattern layer (M2) are used. The range of 10 nm to 30 μm is preferable, the range of 10 nm to 1 μm is more preferable, and the range of 10 nm to 500 nm is further preferable, because the adhesion of the material can be further improved.

When a resin having a reactive functional group [Y] is used as the dispersant for the metal particles, the resin forming the primer layer (B) is a reactive functional group having a reactivity with the reactive functional group [Y]. A resin having [X] is preferable. Examples of the reactive functional group [X] include an amino group, an amide group, an alkyrole amide group, a keto group, a carboxyl group, an anhydrous carboxyl group, a carbonyl group, an acetoacetyl group, an epoxy group, an alicyclic epoxy group and an oxetane. Examples thereof include a ring, a vinyl group, an allyl group, a (meth) acryloyl group, a (blocked) isocyanate group, and a (alkoxy) silyl group. Further, as the compound forming the primer layer (B), a silsesquioxane compound can also be used.

In particular, when the reactive functional group [Y] in the dispersant is a basic nitrogen atom-containing group, the adhesion of the circuit pattern layer (M2) on the insulating substrate (A) can be further improved. The resin forming the primer layer (B) has, as the reactive functional group [X], a keto group, a carboxyl group, a carbonyl group, an acetoacetyl group, an epoxy group, an alicyclic epoxy group, an alkylolamide group, an isocyanate group, and the like. Those having a vinyl group, a (meth) acryloyl group and an allyl group are preferable.

Examples of the resin forming the primer layer (B) include a urethane resin, an acrylic resin, a core-shell type composite resin having a urethane resin as a shell and an acrylic resin as a core, an epoxy resin, an imide resin, an amide resin, and a melamine resin. , Phenolic resin, urea formaldehyde resin, blocked isocyanate obtained by reacting polyisocyanate with a blocking agent such as phenol, polyvinyl alcohol, polyvinylpyrrolidone and the like. The core-shell type composite resin having a urethane resin as a shell and an acrylic resin as a core can be obtained, for example, by polymerizing an acrylic monomer in the presence of a urethane resin. Further, these resins can be used alone or in combination of two or more.

Among the resins forming the primer layer (B), a resin that produces a reducing compound by heating is preferable because the adhesion of the conductive layer (M3) to the insulating substrate (A) can be further improved. Examples of the reducing compound include phenol compounds, aromatic amine compounds, sulfur compounds, phosphoric acid compounds, aldehyde compounds and the like. Among these reducing compounds, phenol compounds and aldehyde compounds are preferable.

When a resin that produces a reducing compound by heating is used as a primer, a reducing compound such as formaldehyde or phenol is produced in the heating and drying step when forming the primer layer (B). Specific examples of the resin that produces a reducing compound by heating include a resin obtained by polymerizing a monomer containing N-alkyrole (meth) acrylamide, and N-alkyrole (meth) acrylamide using a urethane resin as a shell. Core-shell type composite resin with a polymer polymer resin as the core, urea-formaldehyde-methanol condensate, urea-melamine-formaldehyde-methanol condensate, poly N-alkoxymethylol (meth) acrylamide, poly (meth) Examples thereof include a formaldehyde adduct of acrylamide, a resin that produces formaldehyde by heating a melamine resin, and the like; a resin that produces a phenol compound by heating a phenol resin, a phenol block isocyanate, and the like. Among these resins, from the viewpoint of improving adhesion, a core-shell type composite resin having a urethane resin as a shell and a resin obtained by polymerizing a monomer containing N-alkyrole (meth) acrylamide as a core, a melamine resin, and a phenol Blocked isocyanate is preferred.

In the present invention, "(meth) acrylamide" refers to one or both of "methacrylamide" and "acrylamide", and "(meth) acrylic acid" refers to "methacrylic acid" and "acrylic acid". Refers to one or both.

The resin that produces a reducing compound by heating is obtained by polymerizing a monomer having a functional group that produces a reducing compound by heating by a polymerization method such as radical polymerization, anionic polymerization, or cationic polymerization.

Examples of the monomer having a functional group that produces a reducing compound by heating include N-alkyrole vinyl monomer, and specific examples thereof include N-methylol (meth) acrylamide and N-methoxymethyl (N-methoxymethyl). Meta) acrylamide, N-ethoxymethyl (meth) acrylamide, N-propoxymethyl (meth) acrylamide, N-isopropoxymethyl (meth) acrylamide, Nn-butoxymethyl (meth) acrylamide, N-isobutoxymethyl (meth) ) Acrylamide, N-pentoxymethyl (meth) acrylamide, N-ethanol (meth) acrylamide, N-propanol (meth) acrylamide and the like.

In addition, when producing a resin that produces a reducing compound by heating, a monomer having a functional group that produces a reducing compound by heating, and various other types such as (meth) acrylic acid alkyl ester are used. The monomers can also be copolymerized.

When the blocked isocyanate is used as a resin for forming the primer layer (B), a uretdione bond is formed by self-reacting between the isocyanate groups, or the isocyanate group and the functional group of other components are used. Form a bond to form a primer layer (B). The bond formed at this time may be formed before the metal particle dispersion liquid is applied, or is not formed before the metal particle dispersion liquid is applied, and the metal particle dispersion liquid is not formed. May be formed by heating after coating.

Examples of the blocked isocyanate include those having a functional group formed by blocking the isocyanate group with a blocking agent.

The blocked isocyanate is preferably one having the functional group in the range of 350 to 600 g / mol per 1 mol of the blocked isocyanate.

From the viewpoint of improving adhesion, the functional group preferably has 1 to 10 in one molecule of the blocked isocyanate, and more preferably 2 to 5.

The number average molecular weight of the blocked isocyanate is preferably in the range of 1,500 to 5,000, more preferably in the range of 1,500 to 3,000, from the viewpoint of improving adhesion.

Further, as the blocked isocyanate, one having an aromatic ring is preferable from the viewpoint of further improving the adhesion. Examples of the aromatic ring include a phenyl group and a naphthyl group.

The blocked isocyanate can be produced by reacting a part or all of the isocyanate groups of the isocyanate compound with the blocking agent.

Examples of the isocyanate compound as a raw material of the blocked isocyanate include 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, carbodiimide-modified diphenylmethane diisocyanate, crude diphenylmethane diisocyanate, phenylenediocyanate, tolylene diisocyanate, naphthalenedi isocyanate and the like. Polyisocyanate compound having an aromatic ring; an aliphatic polyisocyanate compound such as hexamethylene diisocyanate, lysine diisocyanate, cyclohexanediisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate, or polyisocyanate having an alicyclic structure. Examples include compounds. Moreover, those burette form, isocyanurate form, adduct form and the like of the said polyisocyanate compound are also mentioned.

Further, examples of the isocyanate compound include those obtained by reacting the polyisocyanate compound exemplified above with a compound having a hydroxyl group or an amino group.

When introducing an aromatic ring into the blocked isocyanate, it is preferable to use a polyisocyanate compound having an aromatic ring. Among the polyisocyanate compounds having an aromatic ring, 4,4'-diphenylmethane diisocyanate, tolylene diisocyanate, isocyanurate of 4,4'-diphenylmethane diisocyanate, and isocyanurate of tolylene diisocyanate are preferable.

Examples of the blocking agent used for producing the blocked isocyanate include phenol compounds such as phenol and cresol; lactam compounds such as ε-caprolactam, δ-valerolactam and γ-butyrolactam; Oxime compounds such as methyl ethyl keto oxime, methyl isobutyl keto oxime, cyclohexanone oxime; 2-hydroxypyridine, butyl cellosolve, propylene glycol monomethyl ether, benzyl alcohol, methanol, ethanol, n-butanol, isobutanol, dimethyl malonate, diethyl malonate, acet Methyl acetate, ethyl acetoacetate, acetylacetone, butyl mercaptan, dodecyl mercaptan, acetoanilide, acetate amide, succinate imide, maleate imide, imidazole, 2-methyl imidazole, urea, thiourea, ethylene urea, diphenylaniline, aniline, carbazole, Examples thereof include ethyleneimine, polyethyleneimine, 1H-pyrazole, 3-methylpyrazole, 3,5-dimethylpyrazole and the like. Among these, a blocking agent capable of dissociating to generate an isocyanate group by heating in the range of 70 to 200 ° C. is preferable, and a block capable of producing an isocyanate group dissociating by heating in the range of 110 to 180 ° C. is preferable. Agents are more preferred. Specifically, a phenol compound, a lactam compound, and an oxime compound are preferable, and a phenol compound is more preferable because it becomes a reducing compound when the blocking agent is desorbed by heating.

Examples of the method for producing the blocked isocyanate include a method of mixing and reacting the isocyanate compound produced in advance with the blocking agent, a method of mixing and reacting the blocking agent with a raw material used for producing the isocyanate compound, and the like. Can be mentioned.

More specifically, the blocked isocyanate produces an isocyanate compound having an isocyanate group at the terminal by reacting the polyisocyanate compound with a compound having a hydroxyl group or an amino group, and then the isocyanate compound and the block. It can be produced by mixing and reacting with an agent.

The content ratio of the blocked isocyanate obtained by the above method in the resin forming the primer layer (B) is preferably in the range of 50 to 100% by mass, more preferably in the range of 70 to 100% by mass.

Examples of the melamine resin include mono or polymethylol melamine in which 1 to 6 mol of formaldehyde is added to 1 mol of melamine; (poly) methylol melamine such as trimethoxymethylol melamine, tributoxymethylol melamine, and hexamethoxymethylol melamine. Ethereate (arbitrary degree of etherification); urea-melamine-formaldehyde-methanol condensate and the like.

Further, in addition to the method using a resin that produces a reducing compound by heating as described above, a method of adding a reducing compound to the resin can also be mentioned. In this case, examples of the reducing compound to be added include phenol-based antioxidants, aromatic amine-based antioxidants, sulfur-based antioxidants, phosphoric acid-based antioxidants, vitamin C, vitamin E, and ethylenediamine tetraacetic acid. Examples thereof include sodium, sulfite, hypophosphoric acid, hypophosphite, hydrazine, formaldehyde, sodium hydride, dimethylamine borane, phenol and the like.

In the present invention, the method of adding a reducing compound to a resin may result in deterioration of electrical properties due to the residual low molecular weight component or ionic compound. Therefore, a resin that produces a reducing compound by heating. Is more preferable.

Further, as a preferable resin for forming the primer layer (B), a resin containing a compound having an aminotriazine ring can be mentioned. The compound having an aminotriazine ring may be a compound having a low molecular weight or a resin having a higher molecular weight.

As the low molecular weight compound having an aminotriazine ring, various additives having an aminotriazine ring can be used. Commercially available products include 2,4-diamino-6-vinyl-s-triazine (“VT” manufactured by Shikoku Kasei Co., Ltd.), “VD-3” and “VD-4” manufactured by Shikoku Kasei Co., Ltd. (with aminotriazine ring). (Compound having a hydroxyl group), "VD-5" manufactured by Shikoku Kasei Co., Ltd. (compound having an aminotriazine ring and an ethoxysilyl group) and the like can be mentioned. These can be used by adding one kind or two or more kinds to the resin forming the primer layer (B) as an additive.

The amount of the low molecular weight compound having an aminotriazine ring is preferably 0.1 parts by mass or more and 50 parts by mass or less, and more preferably 0.5 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the resin. ..

As the resin having an aminotriazine ring, a resin in which an aminotriazine ring is introduced by a covalent bond in the polymer chain of the resin can also be preferably used. Specific examples thereof include aminotriazine-modified novolak resins.

The aminotriazine-modified novolak resin is a novolak resin in which an aminotriazine ring structure and a phenol structure are bonded via a methylene group. The aminotriazine-modified novolak resin contains, for example, an aminotriazine compound such as melamine, benzoguanamine, and acetoguanamine, a phenol compound such as phenol, cresol, butylphenol, bisphenol A, phenylphenol, naphthol, and resorcin, and formaldehyde as an alkylamine. It can be obtained by a cocondensation reaction in the vicinity of neutrality in the presence or absence of a weak alkaline catalyst, or by reacting an alkyl etherified compound of an aminotriazine compound such as methyl etherified melamine with the phenol compound.

The aminotriazine-modified novolak resin preferably has substantially no methylol group. Further, the aminotriazine-modified novolak resin may contain a molecule in which only the aminotriazine structure generated as a by-product during its production is methylene-bonded, a molecule in which only the phenol structure is methylene-bonded, and the like. Further, a small amount of unreacted raw material may be contained.

Examples of the phenol structure include phenol residues, cresol residues, butylphenol residues, bisphenol A residues, phenylphenol residues, naphthol residues, resorcin residues and the like. Further, the residue here means a structure in which at least one hydrogen atom bonded to the carbon of the aromatic ring is removed. For example, in the case of phenol, it means a hydroxyphenyl group.

Examples of the triazine structure include structures derived from aminotriazine compounds such as melamine, benzoguanamine, and acetoguanamine.

The phenol structure and the triazine structure can be used alone or in combination of two or more. Further, since the adhesion can be further improved, a phenol residue is preferable as the phenol structure, and a melamine-derived structure is preferable as the triazine structure.

Further, the hydroxyl value of the aminotriazine-modified novolak resin is preferably 50 mgKOH / g or more and 200 mgKOH / g or less, more preferably 80 mgKOH / g or more and 180 mgKOH / g or less, and 100 mgKOH / g or more and 150 mgKOH / g because the adhesion can be further improved. It is more preferably g or less.

The aminotriazine-modified novolak resin can be used alone or in combination of two or more.

When an aminotriazine-modified novolak resin is used as the compound having an aminotriazine ring, it is preferable to use an epoxy resin in combination.

Examples of the epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, biphenyl type epoxy resin, cresol novolac type epoxy resin, phenol novolac type epoxy resin, bisphenol A novolak type epoxy resin, alcohol ether type epoxy resin, and tetrabrom. It has a structure derived from a bisphenol A type epoxy resin, a naphthalene type epoxy resin, a phosphorus-containing epoxy compound having a structure derived from a 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide derivative, and a structure derived from a dicyclopentadiene derivative. Examples thereof include epoxies of fats and oils such as epoxy resin and epoxidized soybean oil. These epoxy resins can be used alone or in combination of two or more.

Among the epoxy resins, bisphenol A type epoxy resin, bisphenol F type epoxy resin, biphenyl type epoxy resin, cresol novolac type epoxy resin, phenol novolac type epoxy resin, and bisphenol A novolak type epoxy resin are selected because the adhesion can be further improved. It is preferable, and in particular, a bisphenol A type epoxy resin is preferable.

Further, the epoxy equivalent of the epoxy resin is preferably 100 g / equivalent or more and 300 g / equivalent or less, more preferably 120 g / equivalent or more and 250 g / equivalent or less, and 150 g / equivalent or more and 200 g / equivalent or less because the adhesiveness can be further improved. More preferred.

When the primer layer (B) is a layer containing an aminotriazine-modified novolak resin and an epoxy resin, the adhesion can be further improved. Therefore, the phenolic hydroxyl group (x) in the aminotriazine-modified novolak resin and the epoxy resin are contained. The molar ratio [(x) / (y)] with the epoxy group (y) is preferably 0.1 or more and 5 or less, more preferably 0.2 or more and 3 or less, and further preferably 0.3 or more and 2 or less.

When forming a layer containing an aminotriazine-modified novolak resin and an epoxy resin as the primer layer (B), a primer resin composition containing the compound having an aminotriazine ring or an epoxy resin is used.

Further, the primer resin composition used for forming the primer layer (B) containing the aminotriazine-modified novolak resin and the epoxy resin may contain, for example, a urethane resin, an acrylic resin, a blocked isocyanate resin, or a melamine resin, if necessary. Other resins such as phenol resin may be blended. These other resins may be used alone or in combination of two or more.

The primer used to form the primer layer (B) preferably contains 1 to 70% by mass of the resin in the primer from the viewpoint of coatability and film forming property, and contains 1 to 20% by mass. The one is more preferable.

Further, examples of the solvent that can be used for the primer include various organic solvents and aqueous media. Examples of the organic solvent include toluene, ethyl acetate, methyl ethyl ketone, cyclohexanone and the like, and examples of the aqueous medium include water, an organic solvent miscible with water, and a mixture thereof.

Examples of the organic solvent to be mixed with water include alcohol solvents such as methanol, ethanol, n-propanol, isopropanol, ethyl carbitol, ethyl cellosolve and butyl cellosolve; ketone solvents such as acetone and methyl ethyl ketone; ethylene glycol, diethylene glycol and propylene. Examples thereof include an alkylene glycol solvent such as glycol; a polyalkylene glycol solvent such as polyethylene glycol, polypropylene glycol and polytetramethylene glycol; and a lactam solvent such as N-methyl-2-pyrrolidone.

Further, the resin forming the primer layer (B) may have a functional group that contributes to the crosslinking reaction, such as an alkoxysilyl group, a silanol group, a hydroxyl group, or an amino group, if necessary. The crosslinked structure formed by utilizing these functional groups may have already formed the crosslinked structure before the step of forming the silver particle layer (M1) in the subsequent step, or the silver particle layer (M1). The crosslinked structure may be formed after the step of forming the above. When the crosslinked structure is formed after the step of forming the silver particle layer (M1), the crosslinked structure may be formed on the primer layer (B) before forming the circuit pattern layer (M2). After forming the circuit pattern layer (M2), a crosslinked structure may be formed in the primer layer (B) by, for example, aging.

If necessary, a known substance such as a cross-linking agent, a pH adjuster, a film forming aid, a leveling agent, a thickener, a water repellent agent, and an antifoaming agent is appropriately added to the primer layer (B). May be used.

Examples of the cross-linking agent include a metal chelate compound, a polyamine compound, an aziridine compound, a metal salt compound, an isocyanate compound and the like, and a thermal cross-linking agent that reacts at a relatively low temperature of about 25 to 100 ° C. to form a cross-linking structure. Examples thereof include thermal cross-linking agents such as melamine-based compounds, epoxy-based compounds, oxazoline compounds, carbodiimide compounds, and blocked isocyanate compounds that react at a relatively high temperature of 100 ° C. or higher to form a cross-linking structure, and various photocross-linking agents. When the aminotriazine-modified novolak resin and the epoxy resin are used as the primer layer (B), it is preferable to use a polyvalent carboxylic acid as the cross-linking agent in the primer resin composition. Examples of the polyvalent carboxylic acid include trimellitic anhydride, pyromellitic anhydride, maleic anhydride, succinic acid and the like. These cross-linking agents may be used alone or in combination of two or more. Further, among these cross-linking agents, trimellitic anhydride is preferable because the adhesion can be further improved.

Although the amount of the cross-linking agent used varies depending on the type, from the viewpoint of improving the adhesion of the circuit pattern layer (M2) on the substrate, it is 0.01 with respect to a total of 100 parts by mass of the resin contained in the primer. The range of about 60 parts by mass is preferable, the range of 0.1 to 10 parts by mass is more preferable, and the range of 0.1 to 5 parts by mass is further preferable.

When the cross-linking agent is used, the cross-linked structure may already be formed before the step of forming the silver particle layer (M1) in the subsequent step, and the cross-linking may be performed after the step of forming the silver particle layer (M1). The structure may be formed. When the crosslinked structure is formed after the step of forming the silver particle layer (M1), the crosslinked structure may be formed on the primer layer (B) before the circuit pattern layer (M2) is formed. After forming the pattern guide (M2), a crosslinked structure may be formed in the primer layer (B) by, for example, aging.

In the present invention, the method of forming the silver particle layer (M1) on the primer layer (B) is the same as the method of forming the silver particle layer (M1) on the insulating base material (A). be.

Further, the primer layer (B) improves the coatability of the silver particle dispersion liquid and improves the adhesion of the circuit pattern layer (M2) to the base material, similarly to the insulating base material (A). For the purpose, surface treatment may be performed before applying the silver particle dispersion.

In step 1 of the method for manufacturing a printed wiring board of the present invention, through holes penetrating both sides are formed in a laminate having a conductive silver particle layer (M1) on both surfaces of an insulating base material (A). It is a process to do.

In step 1, a known and commonly used method may be appropriately selected as a method for forming through holes penetrating both sides of the laminate. For example, drilling, laser processing, or laser processing is used to drill holes in the copper layer. A processing method that combines chemical etching of an insulating substrate using an oxidizing agent, an alkaline agent, an acidic agent, etc., hole pattern etching of a copper foil using a resist, and an oxidizing agent, an alkaline agent, an acidic agent, etc. Examples thereof include a processing method that combines chemical etching of an insulating base material.

The hole diameter (diameter) formed by the drilling process is preferably in the range of 0.01 to 1 mm, more preferably in the range of 0.02 to 0.5 mm, and even more preferably in the range of 0.03 to 0.1 mm. ..

Organic and inorganic dust (smear) generated during drilling process causes poor plating precipitation and deterioration of plating adhesion in the plating process of forming the electrical connection on both sides and the circuit pattern layer (M2), which will be described later. It is preferable to remove dust (desmia) because it may cause the appearance of plating to be spoiled. Desmia methods include, for example, dry treatment such as plasma treatment and reverse sputtering treatment, cleaning treatment with an aqueous solution of an oxidizing agent such as potassium permanganate, cleaning treatment with an aqueous solution of alkali or acid, and wet treatment such as cleaning treatment with an organic solvent. And so on.

In step 2 of the method for manufacturing a printed wiring board of the present invention, either palladium, a conductive polymer, or carbon is applied to the surface of the laminate having through holes formed in step 1, and the surface of the through holes is formed. Is a process of making the material conductive.

The method for making the surface of the through hole conductive is, for example, Minoru Toyonaga, Circuit Technology, vol.8, No. 1 (1993) pp. This can be done with reference to the method described as "Direct Plating" in 47-59.

As a method for making the through-hole surface conductive, (1) palladium-tin colloidal system, (2) tin-free palladium system, (3) conductive polymer system, and (4) graphite system described in the above document. Any one of the four types may be used.

As a method of making the surface of the through hole conductive using palladium-tin colloid, the surface of the laminate on which the through hole is formed is treated with a cleaner-conditioner, and then the tin-palladium colloid is adsorbed on the surface and treated with an accelerator. It is carried out by removing tin. Further, a method of further converting palladium to palladium sulfide to increase conductivity can also be used.

Further, as a method for making the surface of the through hole conductive with a conductive polymer, a method of oxidatively polymerizing a monomer of a pyrrole derivative can be used. The surface of the laminated body in which the through holes are formed is treated with a conditioner and then treated with an aqueous solution of permanganate to form MnO ₂ on the surface of the through holes formed in the insulating base material (A). When a monomer aqueous solution in which a high boiling point alcohol is dissolved is immersed in the surface of the substrate and then immersed in a dilute sulfuric acid aqueous solution, polymerization proceeds on the surface coated with MnO ₂ , and conductivity is achieved by forming a conductive polymer.

Further, as a method of making the surface of the through hole conductive with graphite, the surface of the base material for the semi-additive process method in which the through hole is formed is treated with a suspended carbon black solution, and carbon is adsorbed on the entire surface of the substrate. It can be done by letting it do. By conditioning the surface of the laminated body in which the through holes are formed, the surface of the base material is positively charged, and then carbon black having a negative charge is adsorbed on the surface to ensure conductivity.

As a method for making the surface of the through hole conductive, any of the above-mentioned methods using palladium, a conductive polymer, and carbon can be used, and a commercially available known and conventional process can be used. For example, in the tin-palladium process, a method known as the Crimson process can be used, and in the graphite system, for example, a process known as the black hole process can be utilized. Of these methods, it is preferable to use a method of conducting conductivity using carbon from the viewpoint of materials and process cost.

In step 3 of the method for manufacturing a printed wiring board of the present invention, on the silver particle layer (M1) among any of palladium, a conductive polymer, and carbon used for making the through-hole surface conductive in step 2. This is a step of removing the adsorbed material to expose the conductive silver particle layer (M1).

In step 3, the chemical used for removing any of palladium, the conductive polymer, and carbon adsorbed on the conductive silver particle layer (M1) etches only the surface layer of the silver particle layer (M1). Is preferable. For this purpose, an aqueous solution of persulfate such as ammonium persulfate, sodium persulfate, potassium persulfate, or a sulfuric acid / hydrogen peroxide aqueous solution can be used.

The concentration of the aqueous solution of persulfate or the aqueous solution of sulfuric acid / hydrogen peroxide may be used as long as it can maintain the conductivity that functions as the conductive seed layer (M1') after etching the surface layer of the silver particle layer (M1). It may be adjusted as appropriate according to the design of the etching apparatus.

The laminate from which any of palladium, the conductive polymer, and carbon adsorbed on the conductive silver particle layer (M1) has been removed through step 3 of the method for manufacturing a printed wiring board of the present invention is subjected to a drying step. , Can be used as a laminate for a semi-additive method using a silver particle layer (M1') as a conductive seed.

In step 4 of the method for manufacturing a printed wiring board of the present invention, in step 3, the silver particle layer from which any of palladium, the conductive polymer, and carbon adsorbed on the conductive silver particle layer (M1) is removed. A pattern resist of a circuit pattern is formed on (M1').

As the treatment with the above-mentioned surface treatment agent, for example, a method described in JP-A-7-258870, a method of treatment using a rust preventive agent composed of a triazole-based compound, a silane coupling agent and an organic acid, JP-A. A method for treating with an organic acid, a benzotriazole-based rust preventive agent and a silane coupling agent described in Japanese Patent Application Laid-Open No. 2000-286546, and triazole, thiadiazol and the like described in JP-A-2002-363189. A method for treating a nitrogen-containing heterocycle and a silyl group such as a trimethoxysilyl group or a triethoxysilyl group using a substance having a structure bonded via an organic group having a thioether (sulfide) bond or the like, WO2013 / 186941. A method for treating with a silane compound having a triazole ring and an amino group described in Japanese Patent Application Laid-Open No. 2015-214743, a formyl imidazole compound described in JP-A-2015-214743 is reacted with an aminopropylsilane compound. The method for treating with the imidazole silane compound obtained in the above, the method for treating with the azole silane compound described in JP-A-2016-134454, the single molecule described in JP-A-2017-203073. A method for treating with a solution containing an aromatic compound having an amino group and an aromatic ring, a polybasic acid having two or more carboxyl groups, and a halide ion, triazolesilane described in JP-A-2018-16865. A method of treating with a surface treatment agent containing a compound, or the like can be used.

In the method for manufacturing a printed wiring board of the present invention, in order to form a metal pattern on the surface, a photomask is passed through a photosensitive resist or a direct exposure machine is used to expose the pattern with active light. The exposure amount may be appropriately set as needed. A pattern resist is formed by removing the latent image formed on the photosensitive resist by exposure using a developing solution.

Examples of the developer include a dilute alkaline aqueous solution such as 0.3 to 2% by mass of sodium carbonate and potassium carbonate. A surfactant, a defoaming agent, a small amount of an organic solvent, or the like may be added to the dilute alkaline aqueous solution in order to accelerate development. Further, the substrate exposed above is immersed in a developing solution or developed by spraying the developing solution onto a resist, and by this development, a pattern resist from which the pattern forming portion is removed can be formed. ..

When forming the pattern resist, further, using plasma descam treatment or a commercially available resist residue removing agent, a resist deposit remaining on the hemming portion formed at the boundary portion between the cured resist and the substrate and the surface of the substrate. The resist residue such as may be removed.

As the photosensitive resist used in the present invention, a commercially available resist ink, liquid resist, or dry film resist can be used, and the resolution of the target pattern, the type of the exposure machine used, and the chemical solution used in the plating treatment in the subsequent step can be used. It may be appropriately selected depending on the type, pH and the like.

Examples of commercially available resist inks include "plating resist MA-830" and "etching resist X-87" manufactured by Taiyo Ink Mfg. Co., Ltd .; etching resist and plating resist manufactured by NAZDAR Co., Ltd .; "etching" manufactured by Mutual Chemical Industry Co., Ltd. Examples include the "resist PLAS FINE PER" series and the "plating resist PLAS FINE PPR" series. Examples of the electrodeposition resist include "Eagle series" and "Pepper series" manufactured by Dow Chemical Company. Further, as commercially available dry films, for example, "Fotech" series manufactured by Hitachi Kasei Co., Ltd .; "ALPHO" series manufactured by Nikko Materials Co., Ltd .; "Sunfort" series manufactured by Asahi Kasei Co., Ltd., and "Sunfort" series manufactured by DuPont Co., Ltd. Liston "series and the like.

In order to efficiently manufacture a printed wiring board, it is easy to use a dry film resist, and especially when forming a fine circuit, a dry film for the semi-additive method may be used. Commercially available dry films used for this purpose include, for example, "ALFO LDF500" and "NIT2700" manufactured by Nikko Materials Co., Ltd., "Sunfort UFG-258" manufactured by Asahi Kasei Corporation, and "RD" manufactured by Hitachi Kasei Co., Ltd. Series (RD-2015, 1225) "," RY series (RY-5319, 5325) "," PlateMaster series (PM200, 300) "manufactured by DuPont, and the like can be used.

In step 6 of the method for manufacturing a printed wiring board of the present invention, in order to form a circuit pattern layer (M2) on a substrate, the conductive silver particle layer (M1') is used as a cathode electrode for electrolytic copper plating. Then, by performing the treatment by the electrolytic copper plating method on the silver particle layer (M1') exposed by the development as described above, the through holes of the laminated body are connected by the copper plating, and at the same time, the circuit pattern layer is formed. (M2) can be formed.

Before forming the circuit pattern layer (M2) by the electrolytic copper plating method, the surface of the silver particle layer (M1') may be surface-treated, if necessary. The surface treatment includes cleaning treatment with an acidic or alkaline cleaning liquid, corona treatment, plasma treatment, UV treatment, vapor phase ozone treatment, under the condition that the surface of the silver particle layer (M1') and the formed resist pattern are not damaged. Examples include liquid phase ozone treatment and treatment with a surface treatment agent. These surface treatments can be performed by one method or by using two or more methods in combination.

When the conductive layer (M2) of the circuit pattern is formed on the insulating base material by using the method for manufacturing a printed wiring board of the present invention, annealing is performed after plating for the purpose of stress relaxation and improvement of adhesion of the plating film. May be. Annealing may be performed before the etching step described later, after the etching step, or before and after the etching.

The annealing temperature may be appropriately selected in the temperature range of 40 to 300 ° C. depending on the heat resistance of the substrate to be used and the purpose of use, but is preferably in the range of 40 to 250 ° C. for the purpose of suppressing oxidative deterioration of the plating film. The range of 40 to 200 ° C. is more preferable. The annealing time is preferably 10 minutes to 10 days in the temperature range of 40 to 200 ° C., and 5 minutes to 10 hours in the case of a temperature exceeding 200 ° C. Further, when annealing the plating film, a rust preventive may be appropriately applied to the surface of the plating film.

In step 7 of the method for manufacturing a printed wiring board of the present invention, in step 6, after forming the circuit pattern layer (M2) by plating, the pattern resist formed by using the photosensitive resist is peeled off to form a non-pattern. The silver particle layer (M1') of the formed portion is removed by an etching solution. The pattern resist may be peeled off under the recommended conditions described in the catalog, specifications, etc. of the photosensitive resist used. As the resist stripping solution used for stripping the pattern resist, a commercially available resist stripping solution or a 1.5 to 3% by mass aqueous solution of sodium hydroxide or potassium hydroxide set at 45 to 60 ° C. may be used. can. The resist can be peeled off by immersing the substrate on which the conductive layer (M2) of the circuit pattern is formed in a stripping solution or by spraying the stripping solution with a spray or the like.

Further, the etching solution used for removing the silver particle layer (M1') in the non-pattern forming portion selectively etches only the silver particle layer (M1') to form the circuit pattern layer (M2). Copper is preferably non-etched. Examples of such an etching solution include a mixture of a carboxylic acid and hydrogen peroxide.

Examples of the carboxylic acid include acetic acid, formic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, capric acid, pelargonic acid, capric acid, lauric acid, myristic acid, palmitic acid, margalic acid and stearic acid. Oleic acid, linoleic acid, linolenic acid, arachidonic acid, eikosapentaenoic acid, docosahexaenoic acid, oxalic acid, malonic acid, succinic acid, benzoic acid, salicylic acid, phthalic acid, isophthalic acid, terephthalic acid, gallic acid, melitonic acid, coconut skin Examples thereof include acids, pyruvate, lactic acid, malic acid, citric acid, fumaric acid, maleic acid, aconitic acid, glutaric acid, adipic acid, amino acids and the like. These carboxylic acids can be used alone or in combination of two or more. Among these carboxylic acids, it is preferable to mainly use acetic acid because it is easy to manufacture and handle as an etching solution.

When a mixture of carboxylic acid and hydrogen peroxide is used as the etching solution, it is considered that a percarboxylic acid (peroxycarboxylic acid) is produced by the reaction of hydrogen peroxide with the carboxylic acid. It is presumed that the generated percarboxylic acid preferentially dissolves the silver constituting the silver particle layer (M1') while suppressing the dissolution of the copper constituting the circuit pattern layer (M2).

The mixing ratio of the mixture of the carboxylic acid and hydrogen peroxide is in the range of 2 to 100 mol of hydrogen peroxide with respect to 1 mol of the carboxylic acid because the dissolution of the copper circuit pattern layer (M2) can be suppressed. Preferably, the range of 2 to 50 mol of hydrogen peroxide is more preferable.

The mixture of the carboxylic acid and hydrogen peroxide is preferably an aqueous solution diluted with water. Further, the content ratio of the mixture of the carboxylic acid and hydrogen peroxide in the aqueous solution is preferably in the range of 2 to 65% by mass and preferably in the range of 2 to 30% by mass because the influence of the temperature rise of the etching solution can be suppressed. Is more preferable.

As the water used for the above dilution, it is preferable to use water from which ionic substances and impurities such as ion-exchanged water, pure water, and ultrapure water have been removed.

A protective agent for protecting the copper circuit pattern layer (M2) and suppressing dissolution may be further added to the etching solution. As the protective agent, it is preferable to use an azole compound.

Examples of the azole compound include imidazole, pyrazole, triazole, tetrazole, oxozole, thiazole, selenazole, oxadiazole, thiadiazole, oxatriazole, and thiatriazole.

Specific examples of the azole compound include, for example, 2-methylbenzimidazole, aminotriazole, 1,2,3-benzotriazole, 4-aminobenzotriazole, 1-bisaminomethylbenzotriazole, aminotetrazole, phenyltetrazole, 2 -Phenylthiazole, benzothiazole and the like can be mentioned. These azole compounds may be used alone or in combination of two or more.

The concentration of the azole compound in the etching solution is preferably in the range of 0.001 to 2% by mass, more preferably in the range of 0.01 to 0.2% by mass.

Further, since the dissolution of the copper circuit pattern layer (M2) can be suppressed in the etching solution, it is preferable to add polyalkylene glycol as a protective agent.

Examples of the polyalkylene glycol include water-soluble polymers such as polyethylene glycol, polypropylene glycol, and polyoxyethylene polyoxypropylene block copolymer. Among these, polyethylene glycol is preferable. The number average molecular weight of the polyalkylene glycol is preferably in the range of 200 to 20,000.

The concentration of the polyalkylene glycol in the etching solution is preferably in the range of 0.001 to 2% by mass, more preferably in the range of 0.01 to 1% by mass.

Additives such as sodium salt, potassium salt and ammonium salt of organic acid may be added to the etching solution as necessary in order to suppress fluctuations in pH.

In the method for manufacturing a printed wiring board of the present invention, the silver particle layer (M1') in the non-pattern forming portion is removed by forming the circuit pattern layer (M2) and then using the photosensitive resist to form a pattern resist. This can be done by immersing the peeled substrate in the etching solution or by spraying the etching solution onto the substrate by spraying or the like.

When the silver particle layer (M1') in the non-pattern forming portion is removed by using an etching apparatus, for example, all the components of the etching solution are prepared to have a predetermined composition and then supplied to the etching apparatus. Alternatively, each component of the etching solution may be individually supplied to an etching apparatus, and the respective components may be mixed in the apparatus to prepare a predetermined composition.

The etching solution is preferably used in a temperature range of 10 to 35 ° C., and particularly when an etching solution containing hydrogen peroxide is used, decomposition of hydrogen peroxide can be suppressed, so that the temperature range is 30 ° C. or lower. It is preferable to use in.

After the silver particle layer (M1') is removed with the etching solution, a further cleaning operation other than washing with water is performed for the purpose of preventing the silver component dissolved in the etching solution from adhering to and remaining on the printed wiring board. May be done. For the cleaning operation, it is preferable to use a cleaning solution that dissolves silver oxide, silver sulfide, and silver chloride, but hardly dissolves silver. Specifically, it is preferable to use an aqueous solution containing thiosulfate or tris (3-hydroxyalkyl) phosphine, or an aqueous solution containing mercaptocarboxylic acid or a salt thereof as a cleaning chemical solution.

Examples of the thiosulfate include ammonium thiosulfate, sodium thiosulfate, potassium thiosulfate and the like. Examples of the tris (3-hydroxyalkyl) phosphine include tris (3-hydroxymethyl) phosphine, tris (3-hydroxyethyl) phosphine, and tris (3-hydroxypropyl) phosphine. These thiosulfates or tris (3-hydroxyalkyl) phosphines can be used alone or in combination of two or more.

The concentration when using an aqueous solution containing a thiosulfate may be appropriately set depending on the process time, the characteristics of the cleaning device to be used, etc., but is preferably in the range of 0.1 to 40% by mass, and during cleaning efficiency and continuous use. From the viewpoint of the stability of the chemical solution, the range of 1 to 30% by mass is more preferable.

The concentration of the aqueous solution containing tris (3-hydroxyalkyl) phosphine may be appropriately set depending on the process time, the characteristics of the cleaning device used, and the like, but is in the range of 0.1 to 50% by mass. Preferably, the range of 1 to 40% by mass is more preferable from the viewpoint of cleaning efficiency and stability of the chemical solution during continuous use.

Examples of the mercaptocarboxylic acid include thioglycolic acid, 2-mercaptopropionic acid, 3-mercaptopropionic acid, thioapple acid, cysteine, N-acetylcysteine and the like. Examples of the salt of the mercaptocarboxylic acid include alkali metal salts, ammonium salts, amine salts and the like.

When an aqueous solution of mercaptocarboxylic acid or a salt thereof is used, the concentration is preferably in the range of 0.1 to 20% by mass, and from the viewpoint of cleaning efficiency and process cost when processing a large amount, 0.5 to 15% by mass. The range of is more preferable.

Examples of the method for performing the above cleaning operation include a method of immersing a printed wiring board obtained by etching and removing the silver particle layer (M1) of the non-pattern forming portion in the cleaning chemical solution, and spraying the printed wiring board. A method of spraying a cleaning chemical solution with or the like can be mentioned. The temperature of the cleaning chemical solution can be used at room temperature (25 ° C.), but since the cleaning process can be performed stably without being affected by the outside air temperature, the temperature may be set to 30 ° C. for use.

Further, the step of removing the silver particle layer (M1') of the non-pattern forming portion with an etching solution and the cleaning operation can be repeated as necessary.

As described above, the printed wiring board of the present invention has the purpose of further improving the insulating property of the non-pattern forming portion after removing the silver particle layer (M1') of the non-pattern forming portion with the etching solution. If necessary, a further cleaning operation may be performed. For this cleaning operation, for example, an alkaline permanganate solution in which potassium permanganate or sodium permanganate is dissolved in an aqueous solution of potassium hydroxide or sodium hydroxide can be used.

Cleaning using the alkaline permanganate solution is a method of immersing the printed wiring board obtained by the above method in an alkaline permanganate solution set at 20 to 60 ° C., or the printed wiring board is alkaline by spraying or the like. Examples thereof include a method of spraying a permanganate solution. The printed wiring board is treated with a water-soluble organic solvent having an alcoholic hydroxyl group before cleaning for the purpose of improving the wettability of the alkaline permanganate solution to the surface of the substrate and improving the cleaning efficiency. You may go. Examples of the organic solvent include methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol and the like. These organic solvents may be used alone or in combination of two or more.

The concentration of the alkaline permanganate solution may be appropriately selected as needed, but potassium permanganate or permanganate is added to 100 parts by mass of 0.1 to 10% by mass of potassium hydroxide or sodium hydroxide aqueous solution. It is preferable that 0.1 to 10 parts by mass of sodium is dissolved, and from the viewpoint of cleaning efficiency, potassium permanganate or sodium permanganate is added to 100 parts by mass of 1 to 6% by mass of potassium hydroxide or sodium hydroxide aqueous solution. Is more preferably dissolved in 1 to 6 parts by mass.

When cleaning with the above alkaline permanganic acid solution, it is preferable to treat the washed printed wiring board with a solution having a neutralizing / reducing action after cleaning with the alkaline permanganic acid solution. .. Examples of the liquid having a neutralizing / reducing action include an aqueous solution containing 0.5 to 15% by mass of dilute sulfuric acid or an organic acid. Examples of the organic acid include formic acid, acetic acid, oxalic acid, citric acid, ascorbic acid, and methionine.

The cleaning with the alkaline permanganic acid solution may be performed after the cleaning for the purpose of preventing the silver component dissolved in the etching solution from adhering to and remaining on the printed wiring board, or may be performed in the etching solution. In order to prevent the dissolved silver component from adhering to and remaining on the printed wiring board, instead of cleaning, only cleaning with an alkaline permanganic acid solution may be performed.

Further, the printed wiring board manufactured by using the method for manufacturing the printed wiring board of the present invention can be used for covering the coverlay film on the circuit pattern, forming the solder resist layer, and the circuit pattern, if necessary. As the final surface treatment, nickel / gold plating, nickel / palladium / gold plating, and palladium / gold plating may be performed.

By the method for manufacturing a printed wiring board of the present invention described above, a circuit having a smooth surface having a good rectangular cross-sectional shape, having high adhesion on various smooth substrates, having good design reproducibility, without using a vacuum device. It is possible to manufacture a double-sided connected substrate having a pattern. Therefore, by using the laminate for the semi-additive method of the present invention, it is possible to provide a high-density, high-performance printed wiring board board and a printed wiring board of various shapes and sizes at low cost and satisfactorily. , Highly industrially usable in the field of printed wiring boards. Further, by using the laminated body, not only the printed wiring board but also various members having a metal layer patterned on the surface of the base material on a plane, for example, a connector, an electromagnetic wave shield, an antenna such as RFID, a film capacitor, etc. can be used. Can be manufactured.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. In the following examples and comparative examples, "part" and "%" are both based on mass.

[Production Example 1: Production of Primer (B-1)]
Polyester polyol (polyolpolyol obtained by reacting 1,4-cyclohexanedimethanol, neopentylglycol, and adipic acid in a nitrogen-substituted container equipped with a thermometer, a nitrogen gas introduction tube, and a stirrer) 100 By mass, 17.6 parts by mass of 2,2-dimethylolpropionic acid, 21.7 parts by mass of 1,4-cyclohexanedimethanol, 106.2 parts by mass of dicyclohexylmethane-4,4'-diisocyanate, and 178 parts by mass of methylethylketone. By reacting in the mixed solvent of the above, a urethane prepolymer solution having an isocyanate group at the terminal was obtained.

Next, 13.3 parts by mass of triethylamine was added to the urethane prepolymer solution to neutralize the carboxyl group of the urethane prepolymer, and 380 parts by mass of water was further added to sufficiently stir the urethane prepolymer. An aqueous dispersion was obtained.

8.8 parts by mass of a 25% by mass ethylenediamine aqueous solution was added to the aqueous dispersion of the urethane prepolymer obtained above, and the mixture was stirred to extend the chain of the urethane prepolymer. Then, by aging and removing the solvent, an aqueous dispersion of urethane resin (nonvolatile content: 30% by mass) was obtained. The weight average molecular weight of the urethane resin was 53,000.

Next, 140 parts by mass of deionized water was placed in a reaction vessel equipped with a stirrer, a reflux cooling tube, a nitrogen introduction tube, a thermometer, a dropping funnel for dropping a monomer mixture, and a dropping funnel for dropping a polymerization catalyst, and the urethane obtained above. 100 parts by mass of the aqueous dispersion of the resin was added, and the temperature was raised to 80 ° C. while blowing nitrogen. Then, with stirring, a monomer mixture consisting of 60 parts by mass of methyl methacrylate, 30 parts by mass of n-butyl acrylate and 10 parts by mass of Nn-butoxymethylacrylamide, and 20 parts by mass of a 0.5% by mass ammonium persulfate aqueous solution were added. The parts were dropped from a separate dropping funnel over 120 minutes while keeping the temperature inside the reaction vessel at 80 ° C.

After the dropping is completed, the mixture is further stirred at the same temperature for 60 minutes, cooled to 40 ° C., diluted with deionized water so that the non-volatile content becomes 20% by mass, and then 200 mesh filter cloth is used. By filtering with, an aqueous dispersion of a resin composition for a primer layer, which is a core-shell type composite resin having the urethane resin as a shell layer and an acrylic resin made of methyl methacrylate or the like as a core layer, was obtained. .. Next, isopropanol alcohol and deionized water were added to this aqueous dispersion and mixed so that the mass ratio of isopropanol and water was 7/3 and the non-volatile content was 2% by mass, and the primer (B-1) was added. Got

[Production Example 2: Production of Primer (B-2)]
To a reaction flask equipped with a reflux condenser, a thermometer and a stirrer, 200 parts by mass of water and 350 parts by mass of methanol were added to 600 parts by mass of formalin containing 37% by mass formaldehyde and 7% by mass methanol. Next, a 25% by mass sodium hydroxide aqueous solution was added to this aqueous solution to adjust the pH to 10, then 310 parts by mass of melamine was added, the liquid temperature was raised to 85 ° C., and a methylolation reaction was carried out for 1 hour.

After that, formic acid was added to adjust the pH to 7, and then the mixture was cooled to 60 ° C. and subjected to an etherification reaction (secondary reaction). A 25% by mass sodium hydroxide aqueous solution was added at a cloudiness temperature of 40 ° C. to adjust the pH to 9, and the etherification reaction was stopped (reaction time: 1 hour). The residual methanol was removed under reduced pressure at a temperature of 50 ° C. (methanol removal time: 4 hours) to obtain a primer resin composition containing a melamine resin having a non-volatile content of 80% by mass. Next, methyl ethyl ketone was added to this resin composition and diluted and mixed to obtain a primer (B-2) having a non-volatile content of 2% by mass.

[Production Example 3: Production of Primer (B-3)]
A reaction vessel equipped with a thermometer, a nitrogen gas introduction tube, and a stirrer and substituted with nitrogen, 2,2-dimethylol propionic acid 9.2 parts by mass, polymethylene polyphenyl polyisocyanate ("Millionate MR-" manufactured by Toso Co., Ltd. 200 ”) 57.4 parts by mass and 233 parts by mass of methyl ethyl ketone were charged and reacted at 70 ° C. for 6 hours to obtain an isocyanate compound. Next, 26.4 parts by mass of phenol was supplied as a blocking agent into the reaction vessel, and the reaction was carried out at 70 ° C. for 6 hours. Then, it cooled to 40 degreeC, and the solution of blocked isocyanate was obtained.

Next, 7 parts by mass of triethylamine was added to the solution of the blocked isocyanate obtained above at 40 ° C. to neutralize the carboxyl group of the blocked isocyanate, water was added and the mixture was sufficiently stirred, and then the methyl ethyl ketone was distilled off. Then, a resin composition for a primer layer containing blocked isocyanate having a non-volatile content of 20% by mass and water was obtained. Next, methyl ethyl ketone was added to this resin composition and diluted and mixed to obtain a primer (B-3) having a non-volatile content of 2% by mass.

[Production Example 4: Production of Primer (B-4)]
Novolak resin ("PHENOLITE TD-2131" manufactured by DIC Co., Ltd., hydroxyl group equivalent 104 g / equivalent) 35 parts by mass, epoxy resin ("EPICLON 850-S" manufactured by DIC Co., Ltd .; bisphenol A type epoxy resin, epoxy group equivalent 188 g / equivalent) ) 64 parts by mass and 1 part by mass of 2,4-diamino-6-vinyl-s-triazine (“VT” manufactured by Shikoku Kasei Co., Ltd.), and then diluted with methyl ethyl ketone so that the non-volatile content is 2% by mass. By mixing, a primer (B-4) was obtained.

[Production Example 5: Production of Primer (B-5)]
Novolak resin ("PHENOLITE TD-2131" manufactured by DIC Corporation, hydroxyl group equivalent 104 g / equivalent) 35 parts by mass, epoxy resin ("EPICLON 850-S" manufactured by DIC Corporation; bisphenol A type epoxy resin, epoxy group equivalent 188 g / equivalent) ) 64 parts by mass and 1 part by mass of a silane coupling agent having a triazine ring (“VD-5” manufactured by Shikoku Kasei Co., Ltd.), and then dilute and mix with methyl ethyl ketone so that the non-volatile content is 2% by mass. Then, a primer (B-5) was obtained.

[Production Example 6: Production of Primer (B-6)]
Add 750 parts by mass of phenol, 75 parts by mass of melamine, 346 parts by mass of 41.5% by mass of formalin, and 1.5 parts by mass of triethylamine to a flask equipped with a thermometer, a cooling tube, a fractionation tube, and a stirrer to generate heat. The temperature was raised to 100 ° C. with caution. After reacting at 100 ° C. under reflux for 2 hours, the temperature was raised to 180 ° C. over 2 hours while removing water under normal pressure. Then, the unreacted phenol was removed under reduced pressure to obtain an aminotriazine-modified novolak resin. The hydroxyl group equivalent was 120 g / equivalent.
After mixing 65 parts by mass of the aminotriazine novolak resin obtained above and 35 parts by mass of an epoxy resin (“EPICLON 850-S” manufactured by DIC Co., Ltd .; bisphenol A type epoxy resin, epoxy group equivalent 188 g / equivalent), with methyl ethyl ketone. A primer composition (B-6) was obtained by diluting and mixing so that the non-volatile content was 2% by mass.

[Production Example 7: Production of Primer (B-7)]
After mixing 48 parts by mass of the aminotriazine novolak resin obtained in Production Example 6 and 52 parts by mass of an epoxy resin (“EPICLON 850-S” manufactured by DIC Co., Ltd .; bisphenol A type epoxy resin, epoxy group equivalent 188 g / equivalent), A primer composition (B-7) was obtained by diluting and mixing with methyl ethyl ketone so that the non-volatile content was 2% by mass.

[Production Example 8: Production of Primer (B-8)]
A primer composition having a non-volatile content of 2% by mass in the same manner as in Production Example 78, except that the amounts of the aminotriazine novolak resin and the epoxy resin were changed from 48 parts by mass to 39 parts by mass and from 52 parts by mass to 61 parts by mass, respectively. (B-8) was obtained.

[Production Example 9: Production of Primer (B-9)]
A primer composition having a non-volatile content of 2% by mass in the same manner as in Production Example 8 except that the amounts of the aminotriazine novolak resin and the epoxy resin were changed from 48 parts by mass to 31 parts by mass and from 52 parts by mass to 69 parts by mass, respectively. (B-9) was obtained.

[Production Example 10: Production of Primer (B-10)]
47 parts by mass of the aminotriazine novolak resin obtained in Production Example 7 and 52 parts by mass of an epoxy resin (“EPICLON 850-S” manufactured by DIC Co., Ltd .; bisphenol A type epoxy resin, epoxy group equivalent 188 g / equivalent) are further anhydrous. A primer (B-10) was obtained by mixing 1 part by mass of trimellitic acid and then diluting and mixing with methyl ethyl ketone so that the non-volatile content was 2% by mass.

[Production Example 11: Production of Primer (B-11)]
A reaction vessel equipped with a stirrer, a reflux cooling tube, a nitrogen introduction tube, a thermometer, and a dropping funnel contains 350 parts by mass of deionized water and a surfactant (“Latemuru E-118B” manufactured by Kao Co., Ltd .: 25% by mass of the active ingredient). 4 parts by mass was added, and the temperature was raised to 70 ° C. while blowing nitrogen.

A vinyl monomer mixture consisting of 47.0 parts by mass of methyl methacrylate, 5.0 parts by mass of glycidyl methacrylate, 45.0 parts by mass of n-butyl acrylate, and 3.0 parts by mass of methacrylic acid in a reaction vessel under stirring. And a part of the monomer pre-emulsion obtained by mixing 4 parts by mass of a surfactant (“Aqualon KH-1025” manufactured by Daiichi Kogyo Seiyaku Co., Ltd .: 25% by mass of the active ingredient) and 15 parts by mass of deionized water. 5 parts by mass) was added, and then 0.1 part by mass of potassium persulfate was added, and the mixture was polymerized in 60 minutes while keeping the temperature inside the reaction vessel at 70 ° C.

Next, while maintaining the temperature in the reaction vessel at 70 ° C., the remaining monomer preemulsion (114 parts by mass) and 30 parts by mass of an aqueous solution of potassium persulfate (1.0% by mass of the active ingredient) were separately added dropwise. Dropped over 180 minutes using a funnel. After completion of the dropping, the mixture was stirred at the same temperature for 60 minutes.

It is used in the present invention by cooling the temperature in the reaction vessel to 40 ° C., using deionized water so that the non-volatile content becomes 10.0% by mass, and then filtering with a 200-mesh filter cloth. A resin composition for a primer layer was obtained. Next, water was added to this resin composition to dilute and mix the mixture to obtain a primer (B-11) having a non-volatile content of 5% by mass.

[Preparation Example 1: Preparation of silver particle dispersion]
Silver particles and dispersion by dispersing silver particles having an average particle size of 30 nm in a mixed solvent of 45 parts by mass of ethylene glycol and 55 parts by mass of ion-exchanged water using a compound obtained by adding polyoxyethylene to polyethyleneimine as a dispersant. A dispersion containing the agent was prepared. Then, ion-exchanged water, ethanol and a surfactant were added to the obtained dispersion to prepare a 5% by mass silver particle dispersion.

[Preparation Example 2: Preparation of an etching solution for removing any of palladium, a conductive polymer, and carbon applied on the silver particle layer (M1)]
3.75 g of sulfuric acid and 13.5 g of hydrogen peroxide were added to 1 L of water to prepare an etching solution for removing any of palladium, a conductive polymer, and carbon applied on the silver particle layer (M1). ..

[Preparation Example 3: Preparation of Etching Solution for Silver]
2.6 parts by mass of acetic acid was added to 47.4 parts by mass of water, and 50 parts by mass of 35% by mass hydrogen peroxide solution was further added to prepare an etching solution for silver (1). The molar ratio (hydrogen / carboxylic acid) of hydrogen hydrogen and carboxylic acid in this etching solution for silver (1) is 13.6, and the hydrogen peroxide and carboxylic acid in the etching solution for silver (1) The content ratio of the mixture was 22.4% by mass.

[Preparation Example 4: Preparation of Conductive Polymer Dispersion Liquid]
Based on Patent Document (Japanese Patent Laid-Open No. ^2003-231991 ), a polypyrrole / polyvinylpyrrolidone (PPy / PVP ( _SO4-2 )) colloid doped with sulfate ion was synthesized. Sodium sulfate was used as the dopant, ammonium persulfate was used as the oxidizing agent, and polyvinylpyrrolidone was used as the surfactant. Pyrrole was used as the monomer.
0.85 g of PVP (polyvinylpyrrolidone, manufactured by Wako Pure Chemical Industries, Ltd., special grade) was dissolved in 500 ml of warm water at a temperature of 40 ° C., and in the obtained solution, 7.0 g of ammonium persulfate as an oxidizing agent and sodium sulfate 32 as a dopant were used. .2 g was added, and water was further added to obtain a total volume of 1 L of an aqueous solution. 5 mL of pyrrole (manufactured by Tokyo Kasei Co., Ltd., special grade) was added to the obtained aqueous solution, and the mixture was stirred at room temperature for about 12 hours to carry out chemical oxidative polymerization to obtain a polymerization reaction mixture. This was centrifuged to obtain a black deposit. The resulting deposit was washed several times with water and redistributed in 50 ml of water to give a 10 g / L ( ^PPy / PVP ( _SO4-2 )) aqueous colloidal solution.

(Example 1)
The silver particle dispersion obtained in Preparation Example 1 is placed on the surface of a polyimide film (“Kapton 100EN-C” manufactured by Toray DuPont Co., Ltd .; thickness 25 μm), which is an insulating base material, on a desktop compact coater (RK print). Using a "K printing prober" manufactured by Coat Instrument Co., Ltd., the silver particle layer after drying was coated to be 0.5 g / m ² . Then, it was dried at 160 ° C. for 5 minutes using a hot air dryer. Further, the film was turned over, and the silver particle dispersion obtained in Preparation Example 1 was coated in the same manner as above so that the silver particle layer was 0.5 g / m ² , and the temperature was 160 ° C. using a hot air dryer. A silver particle layer was formed on both surfaces of the polyimide film by drying in. The film substrate thus obtained was fired at 250 ° C. for 5 minutes, and the continuity of the silver particle layer was confirmed with a tester.

On the polyimide film having conductive silver particle layers on both surfaces obtained above, a film was used at the connection position to the back surface solid GND at the transmission characteristic evaluation terminal of a microstrip line with a wiring length of 100 mm and an impedance of 50 Ω. A through hole having a diameter of 100 μm was formed in the hole. The substrate with through holes thus obtained is passed through a black hole process (conditioning-carbon adsorption treatment-etching) of McDermid to attach carbon to the surface of the through holes, and a silver particle layer to which carbon is attached. By removing (M1) by an etching treatment using the sulfuric acid / hydrogen peroxide aqueous solution produced in Preparation Example 2, carbon adhering to the silver particle layer (M1) is removed, and the conductive silver particle layer (M1) is removed. M1) was exposed. By inspecting the front and back surfaces of the silver particle layer on the film with a tester, it was confirmed that the front and back surfaces were electrically connected and the conductivity was ensured.

A dry film resist (“Fotech RD-1225” manufactured by Hitachi Chemical Co., Ltd .; resist film thickness 25 μm) was pressure-bonded onto the silver particle layer (M1) thus obtained at 100 ° C. using a roll laminator. Then, using a direct exposure digital imaging device (“Nuvogo1000R” manufactured by Orbotec), a microstrip line pattern with a wiring length of 100 mm and an impedance of 50 Ω on the resist, and a through-hole terminal connected to the GND for the measurement probe. The pad pattern was exposed. Then, by developing with a 1 mass% sodium carbonate aqueous solution, a microstrip line pattern and a pattern resist from which the probe terminal pad portion was removed were formed on the silver particle layer (M1), and silver on the polyimide film was formed. The particle layer (M1) was exposed.

Next, the surface of the silver particle layer of the base material on which the pattern resist was formed was placed on the cathode, and an electrolytic plating solution containing copper sulfate (copper sulfate 60 g / L, sulfuric acid 190 g / L, chlorine ion) with phosphorus-containing copper as an anode. Microstrip from which resist was removed by electrolytic plating at a current density of 2 A / dm2 for 41 minutes using 50 mg / L, an additive (Copper Grim ST-901, manufactured by Roam & Haas Electronic Materials Co., Ltd.). A circuit pattern layer (M2) having a thickness of 18 μm was formed on the pattern and the probe terminal pad portion by electrolytic copper plating. Next, a film on which a metal pattern made of copper was formed was subjected to a 3% by mass sodium hydroxide aqueous solution set at 50 ° C. The pattern resist was peeled off by immersing in.

Next, the film obtained above was immersed in the etching agent for silver obtained in Preparation Example 3 at 25 ° C. for 30 seconds to remove the silver particle layer other than the circuit pattern, and a printed wiring board was obtained. .. The cross-sectional shape of the circuit forming part (microstrip line and proben terminal part) of the manufactured printed wiring board shows a rectangular shape with no decrease in wiring height and wiring width and no undercut, and is smooth. It was a circuit pattern layer (M2) on the surface.

(Example 2)
The circuit pattern layer (M2) of the microstrip line pattern was formed in the same manner as in Example 1 except that the silver particle layer after drying was changed from 0.5 g / m ² to 0.8 g / m ² . A printed wiring board to have was obtained. The cross-sectional shape of the circuit forming part (microstrip line and proben terminal part) of the manufactured printed wiring board shows a rectangular shape with no decrease in wiring height and wiring width and no undercut, and is smooth. It was a circuit pattern layer (M2) on the surface.

(Example 3)
A printed wiring board having a circuit pattern layer (M2) of a microstrip line pattern was obtained in the same manner as in Example 2 except that the diameter of the through hole was changed from 100 μm by a drill to 70 μm by a laser. .. The cross-sectional shape of the circuit forming part (microstrip line and proben terminal part) of the manufactured printed wiring board shows a rectangular shape with no decrease in wiring height and wiring width and no undercut, and is smooth. It was a circuit pattern layer (M2) on the surface.

(Example 4)
The circuit pattern layer (M2) of the microstrip line pattern was formed in the same manner as in Example 1 except that the silver particle layer after drying was changed from 0.5 g / m ² to 1.5 g / m ² . A printed wiring board to have was obtained. The cross-sectional shape of the circuit forming part (microstrip line and proben terminal part) of the manufactured printed wiring board shows a rectangular shape with no decrease in wiring height and wiring width and no undercut, and is smooth. It was a circuit pattern layer (M2) on the surface.

(Example 5)
On the surface of a polyimide film (“Capton 100EN-C” manufactured by Toray DuPont Co., Ltd., thickness 25 μm), the primer (B-1) obtained in Production Example 1 was applied to a desktop compact coater (RK Print Coat Instrument Co., Ltd.). The film was coated to a thickness of 120 nm after drying using a “K printing prober”), and then dried at 80 ° C. for 5 minutes using a hot air dryer. Further, the film was turned inside out. In the same manner as above, the primer (B-1) obtained in Production Example 1 was coated so that the thickness after drying was 120 nm, and dried at 80 ° C. for 5 minutes using a hot air dryer. Primer layers were formed on both surfaces of the polyimide film.

The insulating base material (A) was applied to both surfaces of the polyimide film in the same manner as in Example 2 except that the polyimide film was changed to a polyimide having primer layers formed on both surfaces of the polyimide film obtained above. A conductive silver particle layer (M1) is formed on the formed primer layer (B) so that the dried silver particle layer becomes 0.8 g / m ² , and thereafter, the same as in Example 2. And obtained a printed wiring board. The cross-sectional shape of the circuit pattern part (microstrip line and proben terminal part) of the manufactured printed wiring board shows a rectangular shape with no decrease in wiring height and wiring width and no undercut, and is smooth. It was a circuit pattern layer (M2) on the surface.

(Example 6)
A printed wiring board having a circuit pattern layer (M2) of a microstrip line pattern was obtained in the same manner as in Example 5 except that the diameter of the through hole was changed from 100 μm by a drill to 70 μm by a laser. .. The cross-sectional shape of the circuit forming part (microstrip line and proben terminal part) of the manufactured printed wiring board shows a rectangular shape with no decrease in wiring height and wiring width and no undercut, and is smooth. It was a circuit pattern layer (M2) on the surface.

(Examples 7 to 22)
The microstrip line pattern is the same as in Example 6 except that the type of primer used for the primer layer, its drying conditions, the amount of silver in the silver particle layer, and the through-hole formation method are changed to those shown in Table 1 or 2. A printed wiring board having the circuit pattern layer (M2) of the above was obtained. The cross-sectional shape of the circuit forming part (microstrip line and proben terminal part) of the manufactured printed wiring board shows a rectangular shape with no decrease in wiring height and wiring width and no undercut, and is smooth. It was a circuit pattern layer (M2) on the surface.

(Example 23)
In Example 7, instead of passing the substrate with through holes through a MacDermid black hole process (conditioning-carbon adsorption treatment-etching), it contains 1 g / l of palladium chloride, 1 ml / l of hydrochloric acid and 1 g / l of dimethylthiourea. It was immersed in the catalyst solution at 25 ° C. for 3 minutes. Then, the substrate was washed with water and treated with a reducing solution containing 10 g / l of dimethylamine borane and 5 g / l of sodium hydroxide at 50 ° C. for 2 minutes, and the surface of the through hole was made conductive with palladium. After washing this substrate with water, the conductive silver particle layer (M1) on the polyimide film was exposed by removing it by an etching treatment using the sulfuric acid / hydrogen peroxide aqueous solution prepared in Preparation Example 2. By inspecting the front and back surfaces of the silver particle layer on the film with a tester, it was confirmed that the front and back surfaces were electrically connected and the conductivity was ensured.
After forming the pattern resist, a printed wiring board having a circuit pattern layer (M2) of a microstrip line pattern was obtained in the same manner as in Example 7. The cross-sectional shape of the circuit forming part (microstrip line and proben terminal part) of the manufactured printed wiring board shows a rectangular shape with no decrease in wiring height and wiring width and no undercut, and is smooth. It was a circuit pattern layer (M2) on the surface.

(Example 24)
(Example 24)
In Example 7, instead of passing the substrate with through holes through the black hole process (conditioning-carbon adsorption treatment ^- etching) of MacDermid, the aqueous solution prepared in Preparation Example ₄ (PPy / PVP (SO 4-2)). The colloidal liquid was immersed in the colloidal liquid at room temperature for 2 minutes to attach colloidal particles to the surface of the through hole, and the surface of the through hole was made conductive by a conductive polymer. After washing this substrate with water, the conductive silver particle layer (M1) on the polyimide film was exposed by removing it by an etching treatment using the sulfuric acid / hydrogen peroxide aqueous solution prepared in Preparation Example 2. By inspecting the front and back surfaces of the silver particle layer on the film with a tester, it was confirmed that the front and back surfaces were electrically connected and the conductivity was ensured.
After forming the pattern resist, a printed wiring board having a circuit pattern layer (M2) of a microstrip line pattern was obtained in the same manner as in Example 7. The cross-sectional shape of the circuit forming part (microstrip line and proben terminal part) of the manufactured printed wiring board shows a rectangular shape with no decrease in wiring height and wiring width and no undercut, and is smooth. It was a circuit pattern layer (M2) on the surface.

(Comparative Example 1)
Instead of using a polyimide film having silver particle layers formed on both sides, a commercially available 25 μm-thick polyimide-based FCCL (“Yupicel N-BE1310YSB” manufactured by Ube Eximo Co., Ltd.) having a roughened copper foil with a thickness of 3 μm as a plating base layer on both sides. In the same manner as in Example 1 above, a through hole penetrating both sides is formed and passed through a black hole process (conditioning-carbon adsorption treatment-etching) of McDermid, and carbon is applied to the surface of the through hole. And the surface of the copper foil to which carbon was attached was removed by an etching treatment using the sulfuric acid / hydrogen peroxide aqueous solution prepared in Preparation Example 2, so that copper was applied to both surfaces of the insulating base material (A). A base material having a foil and further having through holes connecting both sides of the insulating base material and having a through hole surface whose conductivity was ensured by carbon was obtained.
After that, in the same manner as in Example 1 except that a pattern resist is formed on the surface of the copper foil instead of the surface of the silver particle layer (M1), a microstrip having a thickness of 18 μm made of copper is placed on the plating base layer of the copper foil. A conductor circuit layer of a line and a probe terminal pad pattern was formed.

Next, when the copper seed was removed by immersing it in a sulfuric acid / hydrogen peroxide flash etching solution used for copper seed etching, the conductive layer (M3) of the microstrip line was etched and the film thickness was about 3 μm. As it became thinner, the wiring width decreased by about 6 μm, and the cross-sectional shape became "trapezoidal" because it could not hold a rectangle. Further, the surface of the conductive layer of copper was roughened by etching to reduce the smoothness.

(Comparative Example 2)
Instead of using a polyimide film having silver particle layers formed on both sides, nickel / chromium (thickness 30 nm, nickel / chromium mass ratio = 80/20) and 70 nm copper are sputtered as a plating base layer on both sides to a thickness of 1 μm. On the copper foil plating base layer in the same manner as in Comparative Example 1 above, except that the electrolytic copper-plated polyimide film (“Capton 100EN-C” manufactured by Toray DuPont Co., Ltd .; thickness 25 μm) was used. A 18 μm thick microstrip line made of copper and a conductor circuit layer of a probe terminal pad pattern were formed.

Next, when the copper seed was removed by immersing it in a sulfuric acid / hydrogen peroxide flash etching solution used for copper seed etching, the conductive layer (M3) of the microstrip line was etched and the film thickness was about 1 μm. As it became thinner, the wiring width decreased by about 2 μm, and the cross-sectional shape became "trapezoidal" because it could not hold a rectangle. Further, the surface of the conductive layer of copper was roughened by etching to reduce the smoothness. Further, in the region other than the conductive layer (M3) pattern, only the copper layer was removed, and the nickel / chromium layer remained without being removed.

[Check for undercut and cross-sectional shape of wiring]
The cross section of the comb tooth electrode portion of the printed wiring plate obtained above was magnified 500 to 10,000 times with a scanning electron microscope (“JSM7800” manufactured by Nippon Denshi Co., Ltd.) and observed to determine the presence or absence of undercut and the comb. The cross-sectional shape of the tooth electrode was confirmed.
By observing the wiring surface of the produced printed wiring board with a laser microscope (manufactured by KEYENCE, VK-9710), the surface roughness of the wiring surface is confirmed, and those having an Rz of 3 μm or less are smooth (smoothness). : ○) was evaluated. Further, when the difference between the design width of the wiring by the resist used for wiring formation and the upper surface width of the formed wiring is 2 μm or less, the side etch is suppressed and the rectangular shape can be maintained (rectangularity: ○). Then, it is shown in Tables 1 and 2.

1: Insulating base material 2: Silver particle layer 3: Through hole (through hole)
4: Palladium, conductive polymer, carbon 5: Pattern resist 6: Conductive layer (electrolytic copper plating layer)
(A) Laminated body for semi-additive construction method (configuration of claim 1)
(B) Step 1: Through hole (through hole) formation (c) Step 2: Through hole conductivity (d) Step 3: Exposure of conductive silver particle layer (e) Step 4: Pattern resist formation (f) Step 5 : Conductive layer formation by electrolytic copper plating (g) Step 6: Pattern resist peeling (h) Step 6: Silver seed removal (configuration of claim 11)

Claims

Step 1, in which through holes penetrating both sides are formed in a laminate having a conductive silver particle layer (M1) on both surfaces of the insulating base material (A).
Step 2, in which either palladium, a conductive polymer, or carbon is applied onto the surface of the silver particle layer (M1) and the base material having through holes to make the through hole surface conductive.
Step 3, in which any one of palladium, the conductive polymer, and carbon applied on the silver particle layer (M1) is removed to expose only the conductive silver particle layer (M1').
Step 4 of forming a pattern resist on the conductive silver particle layer (M1').
Step 5, in which both sides of the base material and the surface of the through hole are electrically connected by electrolytic copper plating and a circuit pattern layer (M2) is formed.
Step 6 of peeling off the pattern resist and removing the silver particle layer (M1) of the non-circuit pattern forming portion with an etching solution.
A method for manufacturing a printed wiring board, which comprises.
The method for manufacturing a printed wiring board according to claim 1, wherein a laminate having a primer layer (B) is used between the insulating base material (A) and the silver particle layer (M1).
The method for manufacturing a printed wiring board according to claim 1 or 2, wherein the silver particles constituting the silver particle layer (M1) are coated with a polymer dispersant.
In the laminate for the semi-additive method according to claim 2, the primer layer (B) is a layer composed of a resin having a reactive functional group [X], and the polymer dispersant is a reactive functional group [Y]. ], And the method for producing a printed wiring board according to claim 3, wherein the reactive functional group [X] and the reactive functional group [Y] can form a bond with each other by a reaction.
The method for producing a printed wiring board according to claim 4, wherein the reactive functional group [Y] is a basic nitrogen atom-containing group.
The fifth aspect of claim 5, wherein the polymer dispersant having the reactive functional group [Y] is one or more selected from the group consisting of polyalkyleneimine and polyalkyleneimine having a polyoxyalkylene structure containing an oxyethylene unit. How to manufacture printed wiring boards.
The reactive functional group [X] is selected from the group consisting of a keto group, an acetoacetyl group, an epoxy group, a carboxyl group, an N-alkyrole group, an isocyanate group, a vinyl group, a (meth) acryloyl group and an allyl group1 The method for manufacturing a printed wiring board according to any one of claims 4 to 6, which is more than one kind.