JP7371778B2 - Laminated body for semi-additive construction method and printed wiring board using the same - Google Patents

Description

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

A printed wiring board is a board in which a metal layer with a circuit pattern is formed on the surface of an insulating base material. In recent years, with the demand for smaller and lighter electronic products, there has been a demand for thinner printed wiring boards (films) and higher definition circuit wiring. Conventionally, the method for manufacturing circuit wiring is to form an etching resist in the shape of a circuit pattern on the surface of a copper layer formed on an insulating base material, and to etch the copper layer in areas where no circuit is required. The subtractive method of forming has been widely used. However, in the subtractive method, copper tends to remain at the bottom of the wires, and when the distance between wires becomes shorter due to higher density circuit wiring, there are problems such as short circuits and poor insulation reliability between wires. Additionally, if etching is allowed to proceed further in order to prevent short circuits or improve insulation reliability, the etching solution may get around to the bottom of the resist, causing side etching to progress and resulting in thinner wiring in the width direction. That was a problem. In particular, when areas with different wiring densities coexist, there is a problem that fine wiring existing in the area with low wiring density disappears as etching progresses. Furthermore, the cross-sectional shape of the wiring obtained by the subtractive method is not rectangular, but rather a trapezoidal or triangular shape with a wide base on the base material side, resulting in wiring with different widths in the thickness direction, and electrical There were also issues with the transmission line.

A semi-additive method has been proposed as a method for solving these problems and producing fine wiring circuits. In the semi-additive method, a conductive seed layer is formed on an insulating base material, and a plating resist is formed on the non-circuit forming portion on the seed layer. After forming a wiring portion by electrolytic plating through a conductive seed layer, the resist is peeled off and the seed layer in a non-circuit forming portion is removed to form fine wiring. According to this method, the plating is deposited along the shape of the resist, so 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. Therefore, it is suitable for forming fine wiring.

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

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

On the other hand, as a method that does not roughen the surface or form a modified layer on the surface layer, a method is known in which conductive seeds such as nickel or titanium are formed on an insulating substrate by sputtering (for example, , see Patent Document 2). This method allows the formation of a seed layer without roughening the surface of the substrate, but it requires the use of expensive vacuum equipment, a large initial investment, and there are problems with the size and shape of the substrate. Problems include limitations and a complicated process with low productivity.

As a method for solving the problems of the sputtering method, a method has been proposed in which a coating layer of conductive ink containing metal particles is used as a conductive seed layer (see, for example, Patent Document 3). In this technology, a conductive ink in which metal particles having a particle size of 1 to 500 nm are dispersed is coated on an insulating base material made of a film or sheet, and heat treatment is performed. A technique has been 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.

Patent Document 3 proposes pattern formation by a semi-additive method, and in an example, a base is coated with conductive ink in which copper particles are dispersed, and a conductive seed layer of copper is formed by heat treatment. A photosensitive resist is formed on the conductive seed layer using the material as a base material for the semi-additive method. After exposure and development, the pattern forming area is thickened with electrolytic copper plating. After peeling off the resist, copper etching away the conductive seed layer is described. In addition, in the case of printed wiring board formation using the semi-additive method that has been studied in the past, 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 case of a combination of a copper conductive seed layer and a copper circuit pattern, the conductive seed layer in the non-patterned area It is known that when removing the circuit pattern, the conductive layer of the circuit pattern is also etched at the same time, resulting in the circuit pattern becoming thinner and thinner, and the surface roughness of the circuit conductive layer also increasing. This was a problem that needed to be solved in manufacturing wiring for high-frequency transmission.
In order to solve these problems, the present inventors used a base material in which a conductive silver particle layer was formed on the surface of an insulating base material as a base material for the semi-additive method, thereby improving the seed layer etching process. , has invented a technique for forming printed wiring boards that do not cause thinning of circuit patterns or thinning of the film, have good design reproducibility, and have smooth circuit layer surfaces. (Non-patent documents 1, 2)
This technology allows circuits to be formed not only on one side but also on both sides. In order to connect circuits on both sides, conductive silver particle layers are provided on both sides of the insulating base material. When making double-sided connections by forming holes in the base material for semi-additive construction, if you perform the conventional double-sided electrical connection process by direct plating, palladium, adsorbed on the conductive seed layer, In the micro-etching process that removes conductive substances such as conductive polymers and carbon, the conductive silver particle layer is damaged and its conductivity decreases, making it difficult to use it as a conductive seed layer for circuit pattern formation. There were cases where it happened.

International Publication No. 2009/004774 Japanese Patent Application Publication No. 9-136378 Japanese Patent Application Publication No. 2010-272837 Akira Murakawa, Norimasa Fukasawa, Wataru Fujikawa, Jun Shiraga: “Copper pattern formation technology using a semi-additive method using silver nanoparticles as a base,” Proceedings of the 28th Microelectronics Symposium, pp285-288, 2018. Akira Murakawa, Shota Shinbayashi, Norimasa Fukasawa, Wataru Fujikawa, Jun Shiraga: “Copper wiring formation by semi-additive method using silver as a seed layer”, Proceedings of the 33rd Spring Conference of the Electronics Packaging Society, 11B2-03, 2019.

The problem to be solved by the present invention is to achieve high adhesion between the base material and the conductor circuit without the need for surface roughening with chromic acid or permanganic acid or the formation of a surface modification layer with alkali, and without using a vacuum device. A planar semi-additive construction method laminate for double-sided connection that can form wiring with a rectangular cross-sectional shape suitable for circuit wiring, with low undercuts, good design reproducibility, and prints using the same. The purpose of the present invention is to provide wiring boards.

As a result of intensive research to solve the above problems, the present inventors have found that a conductive silver particle layer (M1) and a copper layer (M2) are sequentially formed on both surfaces of an insulating base material (A). By using a laminate in which the copper layer (M2) has a layer thickness of 0.1 μm to 2 μm, there is no need for complicated surface roughening or surface modification layer formation, and there is no need to use a vacuum device. It was discovered that it is possible to form a double-sided printed wiring board that has high adhesion between the base material and the conductor circuit, has few undercuts, has good design reproducibility, and has a rectangular cross-sectional shape that is suitable for circuit wiring. , completed the invention.

That is, the present invention
1. A planar semi-additive construction laminate for electrically connecting both sides of a base material,
A conductive silver particle layer (M1) and a copper layer (M2) are sequentially laminated on both surfaces of the insulating base material (A),
A laminate for semi-additive construction, characterized in that the copper layer (M2) has a layer thickness of 0.1 μm to 2 μm.

2. 2. The laminate for semi-additive construction according to 1, further comprising a primer layer (B) between the insulating base material layer (A) and the conductive silver particle layer (M1).

3. A planar semi-additive construction laminate for electrically connecting both sides of a base material,
Having a conductive silver particle layer (M1) on both surfaces of the insulating base material (A),
Furthermore, the semi-additive material has a through hole connecting both sides of the insulating base material, and the surface of the through hole is a base material whose conductivity is ensured by palladium, a conductive polymer, or carbon. Laminated body for construction method.

4. 4. The laminate for semi-additive construction according to 3, further comprising a primer layer (B) between the insulating base material (A) and the conductive silver particle layer (M1).

5. 5. The laminate for semi-additive construction according to any one of 1 to 4, wherein the silver particles constituting the silver particle layer (M1) are coated with a polymer dispersant.

6. The primer layer (B) described in 2 and 4 above is a layer composed of a resin having a reactive functional group [X], and the polymer dispersant has a reactive functional group [Y], 5. The laminate for semi-additive construction according to 2 or 4, wherein the reactive functional group [X] and the reactive functional group [Y] are capable of forming a bond with each other by reaction.

7. 7. The laminate for semi-additive construction according to 6, wherein the reactive functional group [Y] is a basic nitrogen atom-containing group.

8. Semi according to 6, wherein the polymer dispersant having the reactive functional group [Y] is one or more selected from the group consisting of polyalkylene imine and polyalkylene imine having a polyoxyalkylene structure containing an oxyethylene unit. Laminate for additive construction method.

9. 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-alkylol group, an isocyanate group, a vinyl group, a (meth)acryloyl group, and an allyl group. 6. The laminate for semi-additive construction method according to 6, which is a type or more.

10. A printed wiring board, characterized in that it is formed using the laminate for semi-additive construction method according to any one of items 1 to 9.

11. A printed wiring board in which both sides of the base material are electrically connected,
A wiring part in which a silver particle layer (M1) and a conductive layer (M3) are sequentially laminated on an insulating base material (A) and a through hole connecting both sides of the insulating base material are made of palladium, conductive polymer, or carbon. 11. The printed wiring board according to 10, having a double-sided connection structure in which any one of the following and a copper layer are laminated.

12. 12. The printed wiring board according to 11, further comprising a primer layer (B) between the insulating base material (A) and the silver particle layer (M1).

13. A silver particle layer (M1) and a copper layer (M2) are sequentially laminated on both surfaces of the insulating base material (A), and the layer thickness of the copper layer (M2) is 0.1 μm to 2 μm. Step 1 of forming a through hole penetrating both sides of the laminate;
Step 2 of applying palladium, a conductive polymer, or carbon to the surface of the base material having the through hole to make the surface of the through hole electrically conductive;
Step 3 of etching the copper layer (M2) to expose the conductive silver particle layer (M1);
The method for producing a laminate for semi-additive construction method according to any one of claims 3 to 9, characterized in that the method comprises:

14. 14. The method for producing a laminate for semi-additive construction according to 13, further comprising laminating a primer layer (B) between the insulating base material (A) and the silver particle layer (M1).

15. A silver particle layer (M1) and a copper layer (M2) are sequentially laminated on both surfaces of the insulating base material (A), and the layer thickness of the copper layer (M2) is 0.1 μm to 2 μm. Step 1 of forming a through hole penetrating both sides of the laminate;
Step 2 of applying palladium, a conductive polymer, or carbon to the surface of the base material having the through hole to make the surface of the through hole electrically conductive;
Step 3 of etching the copper layer (M2) to expose the conductive silver particle layer (M1);
Step 4 of forming a pattern resist on the conductive silver particle layer (M1);
Step 5 of electrically connecting both sides of the base material and forming a conductive layer (M3) of a circuit pattern by electrolytic copper plating;
Step 6 of peeling off the pattern resist and removing the silver particle layer (M1) in the non-circuit pattern forming area with an etching solution
10. The method for manufacturing a printed wiring board according to 10, characterized in that it has the following.

16. 15. The printed wiring board according to 15, further comprising a primer layer (B) between the insulating base material (A) and the silver particle layer (M1).

By using the laminate for semi-additive construction of the present invention, it is possible to fabricate a double-sided structure with circuit wiring having a good rectangular cross-sectional shape, which has a smooth surface with high adhesion on various smooth substrates without using a vacuum device. It is possible to manufacture connected printed wiring boards with good design reproducibility. Therefore, by using the technology of the present invention, it is possible to provide a multilayer printed wiring board with high density, high performance, and high frequency transmission at a low cost, and it is suitable for industrial use in the field of printed wiring. Highly sexual. Furthermore, the printed wiring board manufactured using the semi-additive construction method laminate of the present invention can be used not only for ordinary printed wiring boards but also for various electronic components having a patterned metal layer on the surface of the base material. For example, it can be applied to connectors, electromagnetic shields, antennas such as RFID, film capacitors, etc.

FIG. 1 is a schematic diagram of a laminate for semi-additive construction according to claim 1. FIG. 2 is a schematic diagram of a laminate for semi-additive construction having a primer layer on the silver particle layer of FIG. 1, according to claim 2. FIG. 3 is a schematic diagram of a laminate for semi-additive construction according to claim 3. FIG. 4 is a schematic diagram of a laminate for semi-additive construction having a primer layer on the silver particle layer of FIG. 3, according to claim 4. FIG. 5 is a process diagram for manufacturing a printed wiring board using the semi-additive construction method laminate shown in FIG.

The laminate for semi-additive construction of the present invention has a conductive silver particle layer (M1) and a copper layer (M2) sequentially laminated on both surfaces of an insulating base material (A),
The layer thickness of the copper layer (M2) is 0.1 μm to 2 μm.

Further, the laminate for semi-additive construction according to a more preferred embodiment of the present invention further includes a primer layer (B) 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, acrylonitrile-butadiene-styrene (ABS). Graft copolymerization of resins, polyarylate resins, polyacetal resins, acrylic resins such as poly(meth)methyl acrylate, polyvinylidene fluoride resins, polytetrafluoroethylene resins, polyvinyl chloride resins, polyvinylidene chloride resins, and acrylic resins. Vinyl chloride resin, polyvinyl alcohol resin, polyethylene resin, polypropylene resin, urethane resin, cycloolefin resin, polystyrene, liquid crystal polymer (LCP), polyetheretherketone (PEEK) resin, polyphenylene sulfide (PPS), polyphenylene sulfone (PPSU), Examples include cellulose nanofiber, silicon, silicon carbide, gallium nitride, sapphire, ceramics, glass, diamond-like carbon (DLC), and alumina.

Moreover, a resin base material containing a thermosetting resin and an inorganic filler can also be suitably used as the insulating base material (A). 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, dicyclopentadiene resin, Examples 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 borosilicate glass. These thermosetting resins and inorganic fillers can be used alone or in combination of two or more.

As for the form of the insulating base material (A), any one of a planar flexible material, a rigid material, and a rigid flexible material can be used. More specifically, the insulating substrate (A) may be a commercially available material molded into a film, sheet, or plate shape, or may be formed into a planar shape from a solution, melt, or dispersion of the resin described above. Molded materials may also be used. Further, the insulating base material (A) may be a base material in which the above-described resin material is formed on a conductive material such as metal, or a printed wiring board on which a circuit pattern is formed. , a base material formed by laminating the above resin materials may also be used.

The silver particle layer (M1) is formed during the formation of a conductive layer (M3), which will become a wiring pattern to be described later, by a plating process when manufacturing a printed wiring board using the printed wiring board laminate of the present invention. Becomes the plating base layer.

The silver particles constituting the silver particle layer (M1) may contain metal particles other than silver, as long as the plating process described below can be carried out without problems, but the proportion of metal particles other than silver is as follows: Since the etching removability of non-circuit forming portions, which will be described later, can be further improved, the content is preferably 5 parts by mass or less, more preferably 2 parts by mass or less, based on 100 parts by mass of silver.

As a method for forming the silver particle layer (M1) on both sides of the planar insulating base material (A), for example, a silver particle dispersion may be applied to both sides of the insulating base material (A). One example is the method of engineering. The coating method of the silver particle dispersion 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, stiffness, etc. of the insulating substrate (A) to be used. It may be selected appropriately depending on the degree. Specific coating methods include, for example, gravure method, offset method, flexographic method, pad printing method, gravure offset method, letterpress method, letterpress reversal method, screen method, microcontact method, reverse method, 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 etc. At this time, the silver particle layer (M1) may be formed on both sides of the insulating base material (A) at the same time, or it may be formed on one side of the insulating base material (A) and then on the other side. may be formed.

The insulating base material (A) and the primer layer (B) formed on the insulating base material (A) improve the coating properties of the silver particle dispersion and serve as a conductive layer (M3) formed in the plating process. ) For the purpose of improving the adhesion to the substrate, surface treatment may be performed before applying the silver particle dispersion. The surface treatment method for the insulating base material (A) is not particularly limited as long as the surface roughness becomes large and fine pitch pattern formability and signal transmission loss due to the rough surface do not become a problem, and various methods may be used. may be selected appropriately. Examples of such surface treatment methods include UV treatment, gas phase ozone treatment, liquid phase ozone treatment, corona treatment, plasma treatment, and the like. These surface treatment methods can be performed by one type of method or two or more types of methods can be used in combination.

After coating the silver particle dispersion on the insulating substrate (A) or the primer layer (B), the solvent contained in the silver particle dispersion is volatilized by drying the coating film. , the silver particle layer (M1) is formed on the insulating base material (A) or on the primer layer (B).

The above drying temperature and time may be appropriately selected depending on the heat resistant temperature of the base material used and the type of solvent used in the metal particle dispersion, which will be described later. A range of 1 to 200 minutes is preferred. Further, in order to form a silver particle layer (M1) with 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 may be coated with silver particles after drying as necessary. Further annealing is performed for the purpose of lowering the electrical resistance of the layer and improving the adhesion between the insulating base material (A) or the primer layer (B) and the silver particle layer (M1). Good too. The temperature and time of annealing may be appropriately selected depending on the heat resistance temperature of the base material used, the required electrical resistance, productivity, etc., and may be performed for 1 minute to 2 weeks at a temperature of 60 to 350°C. . Further, in the temperature range of 60 to 180°C, the time is preferably 1 minute to 2 weeks, and in the temperature range of 180 to 350°C, the time is preferably about 1 minute to 5 hours.

The above-mentioned drying may be carried out by blowing air or without blowing air. Further, drying may be performed in the air, under an atmosphere of replacement with an inert gas such as nitrogen or argon, under an air flow, or under vacuum.

The coating film can be dried naturally at the coating site, or by blowing air or in a dryer such as a constant temperature dryer. In addition, when the insulating base material (A) is a roll film or a roll sheet, following the coating process, the roll material can be dried by continuously moving it in an installed non-heated or heated space.・Can be fired. Examples of heating methods for drying and baking include methods using an oven, hot air drying furnace, infrared drying furnace, laser irradiation, microwave, 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 , and 0.01 to 30 g/m ² . 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 it facilitates the formation of the conductive layer (M3) by the plating process described later and the seed layer removal process by etching described later.

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

Further, in the step of exposing a circuit pattern to active light on a resist layer, which will be described later, the silver particle layer (M1) can be formed for the purpose of suppressing reflection of active light from the silver particle layer (M1), which will be described later. Graphite, carbon, a cyanine compound, a phthalocyanine compound, a dithiol metal complex, a naphthoquinone compound that absorbs the active light is included in the silver particle layer (M1) as long as electrolytic plating can be carried out without problems and the etching removability described below can be ensured. , a diimmonium compound, an azo compound, or other light-absorbing pigment or dye may be included as a light-absorbing agent. These pigments and dyes may be appropriately selected depending on the wavelength of the active light used. Further, these pigments and dyes can be used alone or in combination of two or more. Furthermore, in order to contain these pigments and dyes in the silver particle layer (M1), these pigments and dyes may be blended into the silver particle dispersion liquid described below.

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) well, and various shapes such as spherical, lens-like, polyhedral, flat, rod-like, and wire-like shapes may be used. Silver particles can be used. These silver particles can be used in one type having a single shape, or in combination of two or more types having different shapes.

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

On the other hand, when the silver particles have a shape such as a lens shape, a rod shape, or a wire shape, the short axis thereof is preferably in the range of 1 to 200 nm, more preferably in the range of 2 to 100 nm, and more preferably in the range of 5 to 50 nm. More preferably, the range is .

The silver particles are preferably those mainly composed of silver particles, but as long as they do not interfere with the plating process described below or impair the removability of the silver particle layer (M1) with an etching solution described below, A part of the 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 substituted or mixed with the silver particles is preferably 5% by mass or less in the silver particles, and from the viewpoint of the plating property of the silver particle layer (M1) and the removability with an etching solution, the ratio of the metal is 2% by mass or less. % or less is more preferable.

The silver particle dispersion liquid 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 liquid is monodispersed and uniform. Alternatively, it may be a mixture of particles having an average particle size within the above range.

As the solvent used for the silver particle dispersion, 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 with an organic solvent that is miscible with the water.

Examples of the water-miscible organic solvent 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 include alkylene glycol solvents such as glycol; polyalkylene glycol solvents such as polyethylene glycol, polypropylene glycol, and polytetramethylene glycol; and lactam solvents such as N-methyl-2-pyrrolidone.
Further, examples of the organic solvent include alcohol compounds, ether compounds, ester compounds, ketone compounds, and the like.

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, dodecanol. , tridecanol, tetradecanol, pentadecanol, stearyl alcohol, allyl alcohol, cyclohexanol, terpineol, terpineol, 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 include ether, propylene glycol monobutyl ether, dipropylene glycol monobutyl ether, tripropylene glycol monobutyl ether, and the like.

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

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, tetralin, trimethylbenzenecyclohexane, etc. and can be used in combination with other solvents as necessary. Furthermore, a mixed solvent such as mineral spirit or solvent naphtha can also be used in combination.

The silver particles are stably dispersed in the solvent, and the silver particle layer is formed on the insulating base material (A) or a primer layer (B) formed on the insulating base material (A), which will be described later. There is no particular restriction as long as it forms (M1) well. Moreover, the above-mentioned solvents can be used alone or in combination of two or more kinds.

The content of silver particles in the silver particle dispersion is such that the amount of silver particle layer (M1) formed on the insulating substrate (A) is 0.01 to 30 g using the various coating methods described above. / ^m2 , and adjust the viscosity to have the optimum coating suitability according to the various coating methods mentioned above, but the viscosity is 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.

The silver particle dispersion liquid preferably maintains long-term dispersion stability without agglomerating, coalescing, or precipitating the silver particles in the various solvents described above, and the silver particles are preferably dispersed in the various solvents described above. It is preferable to contain a dispersant for the purpose of dispersion. As such a dispersant, a dispersant having a functional group that coordinates to the metal particles is preferable, such as a carboxyl group, an amino group, a cyano group, an acetoacetyl group, a phosphorus atom-containing group, a thiol group, a thiocyanato group, a glycinate group, etc. Examples include dispersants having functional groups such as groups.

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

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

The basic nitrogen atom-containing group may be present singly or in plurals in one molecule of the dispersant. By containing multiple basic nitrogen atoms in the dispersant, some of the basic nitrogen atom-containing groups contribute to the dispersion stability of the metal particles through interaction with the metal particles, and the remaining basic nitrogen atoms contribute to the dispersion stability of the metal particles. The atom-containing group contributes to improving adhesion to the insulating base material (A). In addition, when a resin having a reactive functional group [X] is used in the primer layer (B) described later, the basic nitrogen atom-containing group in the dispersant has a relationship with this reactive functional group [X]. This is preferable because it allows bonding to be formed and further improves the adhesion of the metal pattern layer (M2) to be described later on the insulating base material (A).

The dispersant improves the stability and coating properties of the dispersion of silver particles, and can form a silver particle layer (M1) exhibiting good adhesion on the insulating substrate (A). , a polymeric dispersant is preferred, and examples of the polymeric dispersant include polyalkyleneimines such as polyethyleneimine and polypropyleneimine, and compounds obtained by adding polyoxyalkylene to the polyalkyleneimine.

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

Specific examples of compounds in which polyoxyalkylene is added to the polyalkyleneimine include block copolymers of polyethyleneimine and polyoxyethylene, and ethylene oxide in some of the imino groups present in the main chain of polyethyleneimine. Examples include those in which a polyoxyethylene structure is introduced through an addition reaction, and those in which an amino group of a polyalkylene imine, a hydroxyl group of polyoxyethylene glycol, and an epoxy group of an epoxy resin are reacted.

Commercially available products of the polyalkylene imine include "PAO2006W", "PAO306", "PAO318", "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 for dispersing the silver particles is preferably in the range of 0.01 to 50 parts by mass based on 100 parts by mass of the silver particles, and the dispersant is preferably used in an amount of 0.01 to 50 parts by mass based on 100 parts by mass of the silver particles. Alternatively, since a silver particle layer (M1) exhibiting good adhesion can be formed on the primer layer (B) described later, the amount is preferably in the range of 0.1 to 10 parts by mass based on 100 parts by mass of the silver particles. Further, since the plating properties 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 of silver particles is not particularly limited and can be produced using various methods. For example, silver particles produced using a gas phase method such as a low vacuum gas evaporation method are Alternatively, the silver compound may be reduced in the liquid phase to directly prepare a dispersion of silver particles. In both the gas phase and liquid phase methods, it is possible to change the solvent composition of the dispersion liquid during production and the dispersion liquid during coating, as appropriate and necessary, by exchanging solvents or adding solvents. Of the gas phase and liquid phase methods, the liquid phase method is particularly preferred because of the stability of the dispersion and the simplicity of the manufacturing process. As a liquid phase method, it can be produced, for example, by reducing silver ions in the presence of the polymer dispersant.

The silver particle dispersion may further contain organic compounds such as a surfactant, a leveling agent, a viscosity modifier, a film-forming aid, an antifoaming agent, and a preservative, if necessary.

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, alkanesulfonate sodium salts, sodium alkyldiphenyl ether sulfonates Examples include anionic surfactants such as salts; cationic surfactants such as alkylamine salts, alkyltrimethylammonium salts, and alkyldimethylbenzylammonium salts.

As the leveling agent, general leveling agents can be used, and examples thereof include silicone compounds, acetylene diol compounds, fluorine compounds, and the like.

As the viscosity modifier, a general thickener can be used, such as an acrylic polymer that can increase the viscosity by adjusting it to alkalinity, a synthetic rubber latex, and a synthetic rubber latex that can increase the viscosity by associating molecules. Examples include urethane resin, hydroxyethyl cellulose, carboxymethyl cellulose, methyl cellulose, polyvinyl alcohol, hydrated castor oil, amide wax, polyethylene oxide, metal soap, dibenzylidene sorbitol, and the like.

As the film-forming aid, general film-forming aids can be used, such as anionic surfactants such as dioctyl sulfosuccinate sodium salt, hydrophobic nonionic surfactants such as sorbitan monooleate, etc. , polyether-modified siloxane, silicone oil, etc.

As the antifoaming agent, general antifoaming agents can be used, and examples thereof include silicone antifoaming agents, nonionic surfactants, polyethers, higher alcohols, polymer surfactants, and the like.

As the preservative, general preservatives can be used, such as isothiazoline preservatives, triazine preservatives, imidazole preservatives, pyridine preservatives, azole preservatives, pyrithione preservatives, etc. can be mentioned.

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

The primer layer (B) is formed by coating a part or the entire surface of the insulating base material (A) with a primer and removing 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 below are dissolved or dispersed in a solvent. It is a composition.

There is no particular restriction on the method of coating the primer on the insulating substrate (A) as long as the primer layer (B) can be formed well, and various coating methods may be used depending on the insulating substrate (A) used. It may be selected appropriately depending on the shape, size, degree of rigidity, etc. Specific coating methods include, for example, gravure method, offset method, flexographic method, pad printing method, gravure offset method, letterpress method, letterpress reversal method, screen method, microcontact method, reverse method, 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 etc.

Further, the method of coating the primer on both sides of the insulating substrate (A) in the form of a film, sheet, or plate is not particularly limited as long as the primer layer (B) can be formed well, and The construction method may be selected as appropriate. In this case, the primer layer (B) may be formed on both sides of the insulating base material (A) at the same time, or it may be formed on one side of the insulating base material (A) and then on the other side. It's okay.

The insulating base material (A) may be subjected to a surface treatment before being coated with the primer in order to improve the coatability of the primer and the adhesion of the conductive layer (M3) to the base material. . As the surface treatment method for the insulating base material (A), the same method as the surface treatment method when forming the silver particle layer (M1) on the above-mentioned insulating base material (A) can be used. .

After coating the primer on the surface of the insulating base material (A), the method of removing the solvent contained in the coating layer to form the primer layer (B) includes, for example, drying using a dryer. A common method is to allow the solvent to evaporate. The drying temperature may be set within a range that allows the solvent to volatilize and does not adversely affect the insulating base material (A), and drying may be performed at room temperature or by heating. The specific drying temperature is preferably in the range of 20 to 350°C, more preferably in the range of 60 to 300°C. Further, 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-mentioned drying may be carried out by blowing air or without blowing air. Further, drying may be performed in the air, in a substituted atmosphere such as nitrogen or argon, or under an air stream, or under vacuum.

When the insulating substrate (A) is a single film, sheet, or plate, drying can be carried out naturally at the coating site, or by blowing air or in a dryer such as a constant temperature dryer. In addition, when the insulating base material (A) is a roll film or a roll sheet, following the coating process, the roll material can be dried by continuously moving it in an installed non-heated or heated space. It can be performed.

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

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

In particular, when the reactive functional group [Y] in the dispersant is a basic nitrogen atom-containing group, the adhesion of the conductive layer (M3) on the insulating base material (A) can be further improved. The resin forming the primer layer (B) includes a keto group, a carboxyl group, a carbonyl group, an acetoacetyl group, an epoxy group, an alicyclic epoxy group, an alkylolamido group, an isocyanate group, and a vinyl reactive functional group [X]. Those having a group, a (meth)acryloyl group, or an allyl group are preferable.

Examples of the resin forming the primer layer (B) include urethane resin, acrylic resin, core-shell type composite resin having a shell of urethane resin and core of acrylic resin, epoxy resin, imide resin, amide resin, and melamine resin. , phenol resin, urea formaldehyde resin, blocked isocyanate obtained by reacting a blocking agent such as phenol with polyisocyanate, polyvinyl alcohol, polyvinylpyrrolidone, and the like. Note that a 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), resins that generate reducing compounds upon heating are preferred because they can further improve the adhesion of the conductive layer (M3) onto the insulating base material (A). Examples of the reducing compound include phenol compounds, aromatic amine compounds, sulfur compounds, phosphoric acid compounds, and aldehyde compounds. Among these reducing compounds, phenol compounds and aldehyde compounds are preferred.

When a resin that generates reducing compounds upon heating is used for the primer, reducing compounds such as formaldehyde and phenol are generated during the heating and drying step when forming the primer layer (B). Specific examples of resins that generate reducible compounds upon heating include, for example, resins polymerized with monomers containing N-alkylol (meth)acrylamide, and resins containing N-alkylol (meth)acrylamide with a shell made of urethane resin. Core-shell type composite resin with a core made of resin obtained by polymerizing monomers, urea-formaldehyde-methanol condensate, urea-melamine-formaldehyde-methanol condensate, poly N-alkoxymethylol (meth)acrylamide, poly(meth) Resins that produce formaldehyde when heated, such as formaldehyde adducts of acrylamide and melamine resins; resins that produce phenolic compounds when heated, such as phenol resins and phenol block isocyanates. Among these resins, from the viewpoint of improving adhesion, core-shell type composite resins with a urethane resin shell and a polymerized resin containing N-alkylol (meth)acrylamide as a core, melamine resins, and phenol resins are used. Blocked isocyanates are 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.

A resin that produces a reducing compound when heated can be obtained by polymerizing a monomer having a functional group that produces a reducing compound when heated, using a polymerization method such as radical polymerization, anionic polymerization, or cationic polymerization.

Examples of monomers having functional groups that produce reducing compounds upon heating include N-alkylol vinyl monomers, specifically N-methylol(meth)acrylamide, N-methoxymethyl( meth)acrylamide, N-ethoxymethyl(meth)acrylamide, N-propoxymethyl(meth)acrylamide, N-isopropoxymethyl(meth)acrylamide, Nn-butoxymethyl(meth)acrylamide, N-isobutoxymethyl(meth)acrylamide ) acrylamide, N-pentoxymethyl (meth)acrylamide, N-ethanol (meth)acrylamide, N-propanol (meth)acrylamide, and the like.

In addition, when producing the above-mentioned resin that generates reducing compounds when heated, in addition to monomers having functional groups that generate reducing compounds when heated, other various types such as (meth)acrylic acid alkyl esters are used. Monomers can also be copolymerized.

When the blocked isocyanate is used as the resin forming the primer layer (B), a uretdione bond is formed by self-reaction between the isocyanate groups, or the isocyanate group and the functional group of another component are formed. forms a bond, thereby forming a primer layer (B). The bond formed at this time may be formed before coating the metal particle dispersion, or may not be formed before coating the metal particle dispersion, and may be formed before coating the metal particle dispersion. It may be formed by heating after coating.

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

The blocked isocyanate preferably has the functional group in a range of 350 to 600 g/mol per mole of the blocked isocyanate.

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

Further, 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.

Furthermore, the blocked isocyanate preferably has an aromatic ring from the viewpoint of further improving adhesion. Examples of the aromatic ring include a phenyl group and a naphthyl group.

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

Examples of the isocyanate compound serving as a raw material for the block isocyanate include 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, carbodiimide-modified diphenylmethane diisocyanate, crude diphenylmethane diisocyanate, phenylene diisocyanate, tolylene diisocyanate, and naphthalene diisocyanate. Polyisocyanate compounds having an aromatic ring; aliphatic polyisocyanate compounds such as hexamethylene diisocyanate, lysine diisocyanate, cyclohexane diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate, or polyisocyanates having an alicyclic structure Examples include compounds. Further, examples thereof include buret forms, isocyanurate forms, adduct forms, etc. of the polyisocyanate compounds described above.

Further, examples of the isocyanate compound include those obtained by reacting the polyisocyanate compounds 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 preferred.

Blocking agents used in the production of the blocked isocyanate include, for example, phenol compounds such as phenol and cresol; lactam compounds such as ε-caprolactam, δ-valerolactam, and γ-butyrolactam; formamide oxime, acetaldoxime, acetone oxime, Oxime compounds such as methyl ethyl ketoxime, methyl isobutyl ketoxime, cyclohexanone oxime; 2-hydroxypyridine, butyl cellosolve, propylene glycol monomethyl ether, benzyl alcohol, methanol, ethanol, n-butanol, isobutanol, dimethyl malonate, diethyl malonate, acetate Methyl acetate, ethyl acetoacetate, acetylacetone, butylmercaptan, dodecylmercaptan, acetanilide, acetamide, succinimide, maleimide, imidazole, 2-methylimidazole, urea, thiourea, ethyleneurea, diphenylaniline, aniline, carbazole, Examples include ethyleneimine, polyethyleneimine, 1H-pyrazole, 3-methylpyrazole, 3,5-dimethylpyrazole, and the like. Among these, blocking agents that can dissociate and generate isocyanate groups by heating in the range of 70 to 200°C are preferred, and blocks that can generate isocyanate groups that dissociate by heating in the range of 110 to 180°C are preferred. A curing agent is more preferable. Specifically, phenol compounds, lactam compounds, and oxime compounds are preferred, and phenol compounds are particularly preferred because they become reducing compounds 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 the raw material used for producing the isocyanate compound, etc. can be mentioned.

More specifically, the blocked isocyanate is produced by reacting the polyisocyanate compound with a compound having a hydroxyl group or an amino group to produce an isocyanate compound having an isocyanate group at the end, and then reacting the isocyanate compound with the block. It can be produced by mixing and reacting with a curing 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 polymethylolmelamine in which 1 to 6 moles of formaldehyde are added to 1 mole of melamine; (poly)methylolmelamine such as trimethoxymethylolmelamine, tributoxymethylolmelamine, and hexamethoxymethylolmelamine; Etherified products (the degree of etherification is arbitrary); examples include urea-melamine-formaldehyde-methanol condensates.

In addition to the method using a resin that generates a reducing compound upon heating as described above, there is also a method of adding a reducing compound to the resin. In this case, the reducing compounds to be added include, for example, phenolic antioxidants, aromatic amine antioxidants, sulfur antioxidants, phosphoric acid antioxidants, vitamin C, vitamin E, and ethylenediaminetetraacetic acid. Examples include sodium, sulfite, hypophosphorous acid, hypophosphite, hydrazine, formaldehyde, sodium borohydride, dimethylamine borane, and phenol.

In the present invention, the method of adding a reducing compound to the resin is recommended because low molecular weight components and ionic compounds may ultimately remain and the electrical properties may deteriorate. A method using is more preferable.

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

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. (aminotriazine ring and (a compound having a hydroxyl group), "VD-5" manufactured by Shikoku Kasei Co., Ltd. (a compound having an aminotriazine ring and an ethoxysilyl group), and the like. These can be used as additives by adding one type or two or more types to the resin forming the primer layer (B).

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

As the resin having an aminotriazine ring, a resin in which an aminotriazine ring is covalently introduced into the polymer chain of the resin can also be suitably used. Specifically, aminotriazine-modified novolac resins are mentioned.

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 novolac resin is, for example, an aminotriazine compound such as melamine, benzoguanamine, or acetoguanamine, a phenol compound such as phenol, cresol, butylphenol, bisphenol A, phenylphenol, naphthol, or resorcinol, and formaldehyde combined with an alkylamine or the like. It can be obtained by cocondensation reaction near neutrality in the presence of a weakly alkaline catalyst or without a catalyst, or by reacting an alkyl etherified product of an aminotriazine compound such as methyl etherified melamine with the phenol compound.

The aminotriazine-modified novolak resin preferably has substantially no methylol group. Furthermore, the aminotriazine-modified novolac resin may contain molecules in which only the aminotriazine structure produced as a by-product during its production is bonded with methylene, molecules in which only the phenol structure is bonded with methylene, and the like. Furthermore, some amount of unreacted raw materials may be included.

Examples of the phenol structure include phenol residues, cresol residues, butylphenol residues, bisphenol A residues, phenylphenol residues, naphthol residues, resorcinol residues, and the like. Furthermore, the term "residue" as used herein means a structure in which at least one hydrogen atom bonded to carbon of an aromatic ring has been removed. For example, phenol 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. Furthermore, since the adhesion can be further improved, the phenol structure is preferably a phenol residue, and the triazine structure is preferably a melamine-derived structure.

Furthermore, the hydroxyl value of the aminotriazine-modified novolac 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 or less, since it can further improve the adhesion. More preferably, it is less than g.

The aminotriazine-modified novolac resins can be used alone or in combination of two or more.

Furthermore, 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.

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

Among the above epoxy resins, bisphenol A epoxy resin, bisphenol F epoxy resin, biphenyl epoxy resin, cresol novolak epoxy resin, phenol novolac epoxy resin, and bisphenol A novolac epoxy resin are preferred because they can further improve adhesion. Preferably, bisphenol A type epoxy resin is particularly preferable.

In addition, 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, since it can further improve the adhesion. 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. The molar ratio [(x)/(y)] to 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 even more preferably 0.3 or more and 2 or less.

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

Furthermore, the primer resin composition used for forming the primer layer (B) containing the aminotriazine-modified novolak resin and epoxy resin may include, for example, urethane resin, acrylic resin, block isocyanate resin, melamine resin, Other resins such as phenol resin may also be blended. These other resins can 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, and preferably 1 to 20% by mass, of the resin from the viewpoint of coating properties and film forming properties. is more preferable.

Furthermore, examples of solvents that can be used in the primer include various organic solvents and aqueous media. Examples of the organic solvent include toluene, ethyl acetate, methyl ethyl ketone, and cyclohexanone, and examples of the aqueous medium include water, organic solvents miscible with water, and mixtures thereof.

Examples of the water-miscible organic solvent 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 include alkylene glycol solvents such as glycol; polyalkylene glycol solvents such as polyethylene glycol, polypropylene glycol, and polytetramethylene glycol; and lactam solvents such as N-methyl-2-pyrrolidone.

Further, the resin forming the primer layer (B) may have a functional group that contributes to a crosslinking reaction, such as an alkoxysilyl group, a silanol group, a hydroxyl group, or an amino group, if necessary. The crosslinked structure formed using these functional groups may already be formed before the step of forming the silver particle layer (M1) in the subsequent step, or A crosslinked structure may be formed after the step of forming. When forming a crosslinked structure after the step of forming the silver particle layer (M1), the crosslinked structure may be formed in the primer layer (B) before forming the conductive layer (M3). After forming the conductive layer (M3), a crosslinked structure may be formed in the primer layer (B), for example, by aging.

In the primer layer (B), known agents such as a crosslinking agent, a pH adjuster, a film forming aid, a leveling agent, a thickener, a water repellent, an antifoaming agent, etc. are appropriately added as necessary. You may also use it as

Examples of the crosslinking agent include a metal chelate compound, a polyamine compound, an aziridine compound, a metal salt compound, an isocyanate compound, etc., and a thermal crosslinking agent that reacts at a relatively low temperature of about 25 to 100°C to form a crosslinked structure; Examples include thermal crosslinking agents and various photocrosslinking agents that react at a relatively high temperature of 100° C. or higher to form a crosslinked structure, such as melamine compounds, epoxy compounds, oxazoline compounds, carbodiimide compounds, and blocked isocyanate compounds. When the aminotriazine-modified novolak resin and epoxy resin are used as the primer layer (B), it is preferable to use a polyhydric carboxylic acid as the crosslinking agent in the primer resin composition. Examples of the polycarboxylic acid include trimellitic anhydride, pyromellitic anhydride, maleic anhydride, and succinic acid. These crosslinking agents can be used alone or in combination of two or more. Moreover, among these crosslinking agents, trimellitic anhydride is preferred because it can further improve adhesiveness.

The amount of the crosslinking agent used varies depending on the type, but from the viewpoint of improving the adhesion of the conductive layer (M3) onto the base material, it is from 0.01 to 100 parts by mass of the resin contained in the primer. The range is preferably 60 parts by weight, more preferably 0.1 to 10 parts by weight, and even more preferably 0.1 to 5 parts by weight.

When using the crosslinking agent, a crosslinked structure may already be formed before the step of forming the silver particle layer (M1) in the subsequent step, or the crosslinking structure may be formed after the step of forming the silver particle layer (M1). A structure may be formed. When forming a crosslinked structure after the step of forming the silver particle layer (M1), the crosslinked structure may be formed in the primer layer (B) before forming the conductive layer (M3), and the conductive layer After forming (M3), a crosslinked structure may be formed in the primer layer (B), for example, by aging.

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

Further, the purpose of the primer layer (B), similar to the insulating base material (A), is to improve the coating properties of the silver particle dispersion and to improve the adhesion of the conductive layer (M3) to the base material. A surface treatment may be performed before applying the silver particle dispersion.

The laminate for semi-additive construction of the present invention has a copper layer (M2) laminated on the silver particle layer (M1).

The copper layer (M2) is laminated on the silver particle layer (M1) to prevent palladium, conductive polymer, and carbon adsorbed onto surfaces other than the inner wall surface of the through hole in the printed wiring board manufacturing method described below. It protects the conductive silver particle layer (M1) during the etching process for removal.

The layer thickness of the copper layer (M2) is determined by the thickness of the silver particle layer in the step of etching the copper layer (M2) to expose the conductive silver particle layer (M1) in the printed wiring board manufacturing method described below. From the viewpoint of efficiently exposing (M1) without damaging it, the thickness is preferably 0.1 μm to 2 μm, more preferably 0.5 μm to 1.5 μm.

In the laminate for semi-additive construction method of the present invention, the method of laminating the copper layer (M2) on the conductive silver particle layer (M1) includes forming the copper layer (M2) on the conductive silver particle layer (M1). It can be formed by performing a dry or wet copper plating method.

Examples of the dry copper plating method include vacuum evaporation, ion plating, and sputtering. Examples of the wet copper plating treatment include electroless copper plating using the silver particle layer (M1) as a plating catalyst, electrolytic copper plating, and a combination of electroless copper plating and electrolytic copper plating. The use of electrolytic plating is advantageous because the plating deposition rate can be increased, resulting in higher manufacturing efficiency.

The copper plating method for forming the copper layer (M2) on the silver particle layer (M1) is not particularly limited, and may be formed by a dry plating method such as a vacuum evaporation method, an ion plating method, or a sputtering method. It may be formed by a wet plating method such as electroless copper plating method, electrolytic copper plating method, a combination of electroless copper plating and electrolytic copper plating, or a combination of dry plating method and wet plating method. It may be formed by combining methods. In either case, a known and commonly used copper plating method can be suitably used.

In the copper plating, it is preferable that copper layers (M2) of the same thickness are formed on the silver particle layers (A) on both surfaces of the insulating base material (A).

In the step of forming the copper layer (M2) by the copper plating method, the surface of the silver particle layer (M1) may be subjected to a surface treatment, if necessary. This surface treatment includes cleaning treatment with an acidic or alkaline cleaning solution, corona treatment, plasma treatment, UV treatment, vapor phase ozone treatment, and liquid treatment under conditions that do not damage the surface of the silver particle layer (M1) or the formed resist pattern. Examples include phase ozone treatment and treatment with a surface treatment agent. These surface treatments can be performed by one type of method, or two or more types of methods can be used in combination.

In step 1 of the method for manufacturing a printed wiring board using the laminate for semi-additive construction of the present invention, a silver particle layer (M1) and a copper layer (M2) are formed on both surfaces of the insulating base material (A). are sequentially laminated, and the layer thickness of the copper layer (M2) is 0.1 μm to 2 μm, or a laminate for semi-additive construction, or between the insulating base material (A) and the silver particle layer (M1). This is a step of forming through holes penetrating both surfaces of the semi-additive construction laminate in which the primer layer (B) is further laminated.

In step 1, as a method for forming the through holes in the laminate for semi-additive construction, any known and commonly used method may be selected as appropriate; for example, drilling, laser processing, or drilling in the copper layer by laser processing A processing method that combines chemical etching of an insulating base material using an oxidizing agent, an alkaline agent, an acidic agent, etc., a hole pattern etching of copper foil using a resist, and an oxidizing agent, an alkaline agent, an acidic agent, etc. Examples include a processing method that combines chemical etching of an insulating base material.

The hole diameter (diameter) of the hole 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 the hole-drilling process can cause poor plating deposition and a decrease in plating adhesion during the plating process that forms electrical connections on both sides and the conductive layer (M3), which will be described later. It is preferable to remove dust (desmear) since it may cause damage to the appearance of the plating. Desmearing methods include, for example, dry treatments such as plasma treatment and reverse sputtering, cleaning treatments with an oxidizing agent aqueous solution such as potassium permanganate, cleaning treatments with an aqueous alkali or acid solution, and wet treatments such as cleaning treatments with organic solvents. Examples include.

In step 2 of the method for manufacturing a printed wiring board using the laminate for semi-additive construction of the present invention, palladium, conductive polymer, and carbon are added to the surface of the laminate having the through holes formed in step 1. This is a step of applying one of these to make the surface of the through hole conductive.

The method of making the surface of the through hole conductive is described, for example, by Minoru Toyonaga, Circuit Technology, vol. 8, No. 1 (1993) pp. This can be carried out by referring to the method described as "direct plating" in 47-59.

Methods for making the surface of the through hole electrically conductive include (1) palladium-tin colloid system, (2) tin-free palladium system, (3) conductive polymer system, and (4) graphite system, which are described in the above literature. Any one of these four types may be used.

As a method for making the surface of the through hole conductive using palladium-tin colloid, the surface of the laminate in which the through hole is formed is treated with a cleaner-conditioner, and then tin-palladium colloid is adsorbed on the surface and then treated with an accelerator. This is done by removing the tin. Furthermore, a method can also be used in which palladium is further converted into palladium sulfide to improve conductivity.

Further, as a method for making the surface of the through hole electrically conductive with a conductive polymer, a method of oxidative polymerization of a pyrrole derivative monomer can be used. After the surface of the laminate in which the through holes are formed is treated with a conditioner, it is treated with a permanganate aqueous solution to form MnO ₂ on the surface of the through holes formed in the insulating base material (A). When the surface of the substrate is immersed in a monomer aqueous solution containing a high boiling point alcohol 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.

Furthermore, as a method for making the surface of the through hole conductive with graphite, the surface of the semi-additive process base material in which the through hole is formed is treated with a suspended carbon black solution to adsorb carbon onto the entire surface of the substrate. This can be done by letting By treating the surface of the laminate with the through holes formed therein with a conditioner, the surface of the base material is positively charged, and then negatively charged carbon black is adsorbed onto the surface to ensure conductivity.

As a method for making the surface of the through-hole electrically conductive, any of the methods using palladium, conductive polymer, or carbon described above can be used, and commercially known and commonly used processes can be used. For example, the tin-palladium process may utilize a method known as the Crimson process, and the graphite system may utilize, for example, a process known as the black hole process. Among these methods, from the viewpoint of materials and process costs, it is preferable to use a method of making the material conductive using carbon.

Step 3 of the method for manufacturing a printed wiring board using the laminate for semi-additive construction of the present invention is a step of etching the copper layer (M2) to expose the conductive silver particle layer (M1). This step is a step for exposing the conductive silver particle layer (M1) that will become a plating seed layer for forming a conductive layer (M3) in the subsequent step, and also for making the through hole conductive in step 2. The purpose is to remove the used palladium, conductive polymer, and carbon from the plating seeds.

In step 3, the chemical used to etch away the 0.1 μm to 2 μm thick copper layer (M2) laminated on the conductive silver particle layer (M1) can efficiently etch the copper layer (M2). However, there is no particular restriction as long as the underlying silver particle layer (M1) is not damaged, and any known and commonly used copper micro-etching solution or soft etching solution can be used. As the etching solution for the copper layer (M2), an aqueous solution of a persulfate such as ammonium persulfate, sodium persulfate, potassium persulfate, etc., or an aqueous sulfuric acid/hydrogen peroxide solution can be used.

The concentration of the persulfate aqueous solution or the sulfuric acid/hydrogen peroxide aqueous solution is determined according to the layer thickness of the copper layer (M2) of the semi-additive method laminate used for manufacturing printed wiring boards, the design of the manufacturing equipment, etc. Although it may be selected as appropriate, it is preferable to set the etching rate of the copper layer to be less than 2 μm/min in the process used, so that the etching rate of the copper layer (M2) can be efficiently removed and the conductive silver that is the underlying layer can be removed. From the viewpoint of preventing damage to the particle layer (M1), the speed of 0.1 μm/min. ~1.5μm/min. It is more preferable to set the etching rate so that the etching rate is as follows.

The laminate in which the copper layer (M2) has been etched through step 3 of the method for producing a printed wiring board using the laminate for semi-additive construction of the present invention is then subjected to a drying step to make the silver particle layer (M1) conductive. It can be used as a seed laminate for semi-additive construction methods. That is, the laminate in which the copper layer (M2) is etched in step 3 of the method for manufacturing a printed wiring board using the laminate for semi-additive construction method of the present invention,
Having a conductive silver particle layer (M1) on both surfaces of the insulating base material (A),
Furthermore, the semi-additive material has a through hole connecting both sides of the insulating base material, and the surface of the through hole is a base material whose conductivity is ensured by palladium, a conductive polymer, or carbon. It becomes a laminate for construction methods.

In step 4 of the method for manufacturing a printed wiring board using the laminate for semi-additive construction of the present invention, a circuit is formed on the silver particle layer (M1) from which the upper copper layer (M2) has been removed in step 3. Forming a pattern resist of the pattern.
In the step 4 of forming a patterned resist, the surface of the silver particle layer (M1) is subjected to cleaning treatment with an acidic or alkaline cleaning solution and corona treatment for the purpose of improving adhesion with the resist layer before forming the resist. Surface treatments such as plasma treatment, UV treatment, gas phase ozone treatment, liquid phase ozone treatment, and treatment with a surface treatment agent may be performed. These surface treatments can be performed by one type of method or two or more types of methods can be used in combination.

Examples of the treatment with the above-mentioned surface treatment agent include a method using a rust preventive agent consisting of a triazole compound, a silane coupling agent, and an organic acid, as described in JP-A-7-258870; A method of treatment using an organic acid, a benzotriazole-based rust preventive agent, and a silane coupling agent is described in Japanese Patent Publication No. 2000-286546, and a method of treatment using a triazole, thiadiazole, etc. Process using a substance having a structure in which a nitrogen-containing heterocycle and a silyl group such as a trimethoxysilyl group or a triethoxysilyl group are bonded via an organic group having a thioether (sulfide) bond, etc., WO2013/186941 A method of treating using a silane compound having a triazine ring and an amino group, which is described in Japanese Patent Publication No. 2015-214743, and a method of reacting a formylimidazole compound with an aminopropylsilane compound, which is described in Japanese Patent Application Laid-open No. 2015-214743. A method of treating with an imidazole silane compound obtained by A method of 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, a triazole silane described in JP 2018-16865A. A method of treating with a surface treatment agent containing a compound, etc. can be used.

In order to form a metal pattern on the surface using the laminate for semi-additive construction of the present invention, the pattern is exposed to active light by passing a photomask through a photosensitive resist or using a direct exposure machine. The exposure amount may be appropriately set as necessary. A pattern resist is formed by removing a latent image formed on a photosensitive resist by exposure using a developer.

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

When forming a patterned resist, furthermore, a descum treatment using plasma or a commercially available resist residue remover is used to remove footings that occur at the boundary between the hardened resist and the substrate and resist deposits remaining on the substrate surface. Resist residues such as those may be removed.

As the photosensitive resist used in the present invention, commercially available resist inks, liquid resists, and dry film resists can be used. It may be selected appropriately depending on the type, pH, etc.

Commercially available resist inks include, for example, "Plating Resist MA-830" and "Etching Resist Examples include the "Resist PLAS FINE PER" series and the "Plating Resist PLAS FINE PPR" series. Examples of electrodeposition resists include "Eagle Series" and "Pepper Series" manufactured by Dow Chemical Company. Furthermore, commercially available dry films include, for example, the "Phototech" series manufactured by Hitachi Chemical Co., Ltd.; the "ALPHO" series manufactured by Nikko Materials Co., Ltd.; the "Sunfort" series manufactured by Asahi Kasei Corporation; Liston" series, etc.

In order to efficiently manufacture a printed wiring board, it is convenient to use a dry film resist, and particularly when forming a fine circuit, a dry film for semi-additive construction 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 series (RD-2015, 1225),” “RY series (RY-5319, 5325),” “Plate Master series (PM200, 300)” manufactured by DuPont, etc. can be used.

In step 5 of the method for manufacturing a printed wiring board of the present invention, in order to form a circuit pattern on a substrate using the laminate for semi-additive construction of the present invention, the conductive silver particle layer (M1) is It is used as a cathode electrode for electrolytic copper plating, and in step 4, the silver particle layer (M1) exposed by development is treated by electrolytic copper plating to connect the through holes of the laminate with copper plating. At the same time, a conductive layer (M3) of a circuit pattern can be formed.

Before forming the conductive layer (M3) by the electrolytic copper plating method, the surface of the silver particle layer (M1) may be subjected to surface treatment, if necessary. This surface treatment includes cleaning treatment with an acidic or alkaline cleaning solution, corona treatment, plasma treatment, UV treatment, vapor phase ozone treatment, and liquid treatment under conditions that do not damage the surface of the silver particle layer (M1) or the formed resist pattern. Examples include phase ozone treatment and treatment with a surface treatment agent. These surface treatments can be performed by one type of method or two or more types of methods can be used in combination.

When forming a conductive layer (M3) with a circuit pattern on an insulating base material using the laminate for semi-additive construction of the present invention, annealing is performed after plating in order to relieve stress and improve adhesion of the plating film. It's okay. Annealing may be performed before or after an etching process, which will be described later, or before or after etching.

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

In step 6 of the printed wiring board manufacturing method of the present invention, in step 5, after forming the conductive layer (M3) by plating on the insulating base material of the laminate for semi-additive construction method of the present invention, The patterned resist formed using a photosensitive resist is peeled off, and the silver particle layer (M1) in the non-patterned area is removed using 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. Furthermore, as the resist stripping solution used when stripping the pattern resist, it is possible to use 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. can. The resist can be removed by immersing the base material on which the conductive layer (M3) of the circuit pattern is formed in a stripping solution, or by spraying the stripping solution with a spray or the like.

In addition, the etching solution used when removing the silver particle layer (M1) in the non-patterned area selectively etches only the silver particle layer (M1), and the copper forming the conductive layer (M3) is Preferably, it is not etched. Such an etching solution includes a mixture of 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, caprylic acid, pelargonic acid, capric acid, lauric acid, myristic acid, palmitic acid, margaric acid, stearic acid, Oleic acid, linoleic acid, linolenic acid, arachidonic acid, eicosapentaenoic acid, docosahexaenoic acid, oxalic acid, malonic acid, succinic acid, benzoic acid, salicylic acid, phthalic acid, isophthalic acid, terephthalic acid, gallic acid, mellitic acid, cinnamic acid Acids include pyruvic acid, 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 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 an etching solution, hydrogen peroxide reacts with the carboxylic acid, thereby producing percarboxylic acid (peroxycarboxylic acid). It is presumed that the generated percarboxylic acid preferentially dissolves the silver forming the silver particle layer (M1) while suppressing the dissolution of the copper forming the conductive layer (M3).

The mixing ratio of the mixture of carboxylic acid and hydrogen peroxide is preferably in the range of 2 to 100 moles of hydrogen peroxide per 1 mole of carboxylic acid, since dissolution of the copper conductive layer (M3) can be suppressed. , more preferably a range of 2 to 50 moles of hydrogen peroxide.

The mixture of 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 in the range of 2 to 30% by mass, since 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 have been removed, such as ion-exchanged water, pure water, and ultrapure water.

A protective agent for protecting the copper conductive layer (M3) 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, thiatriazole, and the like.

Specific examples of the azole compounds include 2-methylbenzimidazole, aminotriazole, 1,2,3-benzotriazole, 4-aminobenzotriazole, 1-bisaminomethylbenzotriazole, aminotetrazole, phenyltetrazole, -Phenylthiazole, benzothiazole, etc. These azole compounds can 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.

Moreover, it is preferable to add polyalkylene glycol to the etching solution as a protective agent since it can suppress dissolution of the copper conductive layer (M3).

Examples of the polyalkylene glycol include water-soluble polymers such as polyethylene glycol, polypropylene glycol, and polyoxyethylene polyoxypropylene block copolymers. Among these, polyethylene glycol is preferred. Further, 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.

The etching solution may contain additives such as sodium salts, potassium salts, and ammonium salts of organic acids, if necessary, in order to suppress pH fluctuations.

In the laminate for semi-additive construction method of the present invention, the removal of the silver particle layer (M1) in the non-pattern-formed area is carried out by peeling off the patterned resist formed using the photosensitive resist after forming the conductive layer (M3). This can be carried out by immersing the base material in the etching solution or by spraying the etching solution onto the base material.

When removing the silver particle layer (M1) in the non-circuit pattern forming area using an etching device, for example, all the components of the etching solution are prepared to have a predetermined composition, and then supplied to the etching device. Alternatively, each component of the etching solution may be individually supplied to an etching device, and the components may be mixed in the device to obtain a predetermined composition.

The etching solution is preferably used in a temperature range of 10 to 35°C, and especially when using an etching solution containing hydrogen peroxide, the temperature range is 30°C or less because decomposition of hydrogen peroxide can be suppressed. It is preferable to use it in

As described above, in the printed wiring board of the present invention, a silver particle layer (M1) and a copper layer (M2) are sequentially laminated on both surfaces of an insulating base material (A), and the copper layer (M2 ) Step 1 of forming through holes penetrating both sides of the laminate having a layer thickness of 0.1 μm to 2 μm;
Step 2 of applying palladium, a conductive polymer, or carbon to the surface of the base material having the through hole to make the surface of the through hole electrically conductive;
Step 3 of etching the copper layer (M2) to expose the conductive silver particle layer (M1);
Step 4 of forming a pattern resist on the conductive silver particle layer (M1);
Step 5 of electrically connecting both sides of the base material and forming a conductive layer (M3) of a circuit pattern by electrolytic copper plating; ) can be manufactured by performing step 6 of removing the film using an etching solution.

After the silver particle layer (M1) is removed with the etching solution, a cleaning operation is performed in addition to water washing in order to prevent the silver component dissolved in the etching solution from adhering to and remaining on the printed wiring board. You may go. In 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 the cleaning chemical solution.

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

When using an aqueous solution containing thiosulfate, the concentration may be set as appropriate depending on the process time, the characteristics of the cleaning equipment used, etc., but it is preferably in the range of 0.1 to 40% by mass, and is suitable for cleaning efficiency and continuous use. From the viewpoint of stability of the chemical solution, the range of 1 to 30% by mass is more preferable.

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

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

When using an aqueous solution of mercaptocarboxylic acid or its salt, 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 in large quantities, it is 0.5 to 15% by mass. The range is more preferable.

Examples of the method for carrying out the above-mentioned cleaning operation include, for example, immersing the printed wiring board obtained by etching away the silver particle layer (M1) in the non-patterned area in the cleaning chemical solution, and spraying the printed wiring board. Examples include a method of spraying a cleaning chemical solution. The temperature of the cleaning chemical solution can be used at room temperature (25° C.), but it may also be used at a temperature of 30° C., for example, since the cleaning process can be performed stably without being affected by the outside temperature.

Further, the step of removing the silver particle layer (M1) in the non-patterned area using an etching solution and the cleaning operation can be repeated as necessary.

As described above, in the printed wiring board of the present invention, after the silver particle layer (M1) in the non-pattern forming area is removed using the etching solution, necessary Depending on the situation, a further washing operation may be performed. For this cleaning operation, for example, an alkaline permanganic acid solution in which potassium permanganate or sodium permanganate is dissolved in an aqueous solution of potassium hydroxide or sodium hydroxide can be used.

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

The concentration of the alkaline permanganate solution may be selected as appropriate, but potassium permanganate or permanganate is added to 100 parts by mass of a 0.1 to 10 mass% potassium hydroxide or sodium hydroxide aqueous solution. Preferably, 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 a 1 to 6 mass% potassium hydroxide or sodium hydroxide aqueous solution. It is more preferable to dissolve 1 to 6 parts by mass of.

When cleaning is performed using the above-mentioned alkaline permanganate solution, it is preferable that the cleaned printed wiring board is treated with a neutralizing/reducing solution after cleaning with the alkaline permanganate solution. . Examples of the neutralizing/reducing liquid include 0.5 to 15% by mass of dilute sulfuric acid or an aqueous solution containing an organic acid. Further, examples of the organic acids include formic acid, acetic acid, oxalic acid, citric acid, ascorbic acid, and methionine.

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

In addition, the printed wiring board obtained using the laminate for printed wiring boards of the present invention may be prepared by laminating a coverlay film on the circuit pattern, forming a solder resist layer, and forming a solder resist layer on the circuit pattern as appropriate. As a final surface treatment, nickel/gold plating, nickel/palladium/gold plating, or palladium/gold plating may be applied.

By using the above-described laminate for semi-additive construction of the present invention, it is possible to fabricate smooth surface circuits with high adhesion, good design reproducibility, and a good rectangular cross-sectional shape on various smooth substrates without using a vacuum device. It is possible to produce double-sided connected substrates with a pattern. Therefore, by using the laminate for semi-additive construction of the present invention, high-density, high-performance printed wiring board substrates and printed wiring boards of various shapes and sizes can be provided in good condition at low cost. , has high industrial applicability in the printed wiring board field. In addition, by using the laminate, not only printed wiring boards but also various members having a patterned metal layer on the surface of the planar base material, such as connectors, electromagnetic shields, antennas such as RFID, film capacitors, etc. Can be manufactured.

Hereinafter, the present invention will be explained in more detail using 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)]
In a nitrogen-substituted container equipped with a thermometer, a nitrogen gas inlet tube, and a stirrer, 100% polyester polyol (polyester polyol obtained by reacting 1,4-cyclohexanedimethanol, neopentyl glycol, and adipic acid) was prepared. Parts by mass, 17.6 parts by mass of 2,2-dimethylolpropionic acid, 21.7 parts by mass of 1,4-cyclohexanedimethanol, and 106.2 parts by mass of dicyclohexylmethane-4,4'-diisocyanate, 178 parts by mass of methyl ethyl ketone. By reacting in a mixed solvent of , a urethane prepolymer solution having isocyanate groups at the terminals was obtained.

Next, 13.3 parts by mass of triethylamine was added to the urethane prepolymer solution to neutralize the carboxyl groups possessed by the urethane prepolymer, and 380 parts by mass of water was added and sufficiently stirred to form 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 urethane prepolymer was chain-extended by stirring. Then, by aging and removing the solvent, an aqueous dispersion of urethane resin (non-volatile 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 added to the urethane obtained above in a reaction vessel equipped with a stirrer, a reflux condenser tube, a nitrogen introduction tube, a thermometer, a dropping funnel for dropping the monomer mixture, and a dropping funnel for dropping the polymerization catalyst. 100 parts by mass of an aqueous resin dispersion was added, and the temperature was raised to 80° C. while blowing nitrogen. Thereafter, while 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 mass% ammonium persulfate aqueous solution were added. were added dropwise from separate dropping funnels over 120 minutes while maintaining the temperature inside the reaction vessel at 80°C.

After the dropwise addition was completed, the reaction vessel was further stirred for 60 minutes at the same temperature, the temperature inside the reaction vessel was cooled to 40°C, the non-volatile content was diluted with deionized water to 20% by mass, and filtered using a 200 mesh filter cloth. By filtration, 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 and deionized water are added and mixed to this aqueous dispersion so that the mass ratio of isopropanol and water is 7/3 and the nonvolatile content is 2 mass%, and primer (B-1) is prepared. I got it.

[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 aqueous sodium hydroxide solution was added to this aqueous solution to adjust the pH to 10, and then 310 parts by mass of melamine was added, the temperature of the solution was raised to 85° C., and a methylolation reaction was carried out for 1 hour.

Thereafter, formic acid was added to adjust the pH to 7, and the mixture was cooled to 60° C. to carry out an etherification reaction (secondary reaction). At a cloudy temperature of 40°C, a 25% by mass aqueous sodium hydroxide solution was added to adjust the pH to 9 to stop the etherification reaction (reaction time: 1 hour). Remaining methanol was removed under reduced pressure at a temperature of 50°C (demethanol removal time: 4 hours) to obtain a primer resin composition containing a melamine resin with a nonvolatile 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) with a nonvolatile content of 2% by mass.

[Production Example 3: Production of primer (B-3)]
In a reaction vessel equipped with a thermometer, a nitrogen gas inlet tube, and a stirrer and purged with nitrogen, 9.2 parts by mass of 2,2-dimethylolpropionic acid and polymethylene polyphenyl polyisocyanate (“Millionate MR-” manufactured by Tosoh Corporation) were placed. 200'') 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 mixture was reacted at 70°C for 6 hours. Thereafter, it was cooled to 40°C to obtain a blocked isocyanate solution.

Next, 7 parts by mass of triethylamine was added to the solution of the block isocyanate obtained above at 40°C to neutralize the carboxyl groups possessed by the block isocyanate, and after adding water and stirring thoroughly, methyl ethyl ketone was distilled off. As a result, a resin composition for a primer layer containing a blocked isocyanate with a nonvolatile 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) with a nonvolatile content of 2% by mass.

[Production Example 4: Production of primer (B-4)]
Novolac resin (“PHENOLITE TD-2131” manufactured by DIC Corporation, hydroxyl 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) ) and 1 part by mass of 2,4-diamino-6-vinyl-s-triazine (“VT” manufactured by Shikoku Kasei Co., Ltd.) were mixed, and then diluted with methyl ethyl ketone so that the nonvolatile content was 2% by mass. By mixing, primer (B-4) was obtained.

[Production Example 5: Production of primer (B-5)]
Novolac resin (“PHENOLITE TD-2131” manufactured by DIC Corporation, hydroxyl 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) ) and 1 part by mass of a silane coupling agent having a triazine ring ("VD-5" manufactured by Shikoku Kasei Co., Ltd.), and then diluted and mixed with methyl ethyl ketone so that the nonvolatile content is 2% by mass. Thus, primer (B-5) was obtained.

[Production Example 6: Production of primer (B-6)]
750 parts by mass of phenol, 75 parts by mass of melamine, 346 parts by mass of 41.5% formalin, and 1.5 parts by mass of triethylamine were added to a flask equipped with a thermometer, cooling tube, fractionator tube, and stirrer, and The temperature was raised to 100°C with care. 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. Next, unreacted phenol was removed under reduced pressure to obtain an aminotriazine-modified novolak resin. The hydroxyl 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 Corporation; bisphenol A type epoxy resin, epoxy group equivalent: 188 g/equivalent), the mixture was mixed with methyl ethyl ketone. A primer composition (B-6) was obtained by diluting and mixing so that the nonvolatile 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 epoxy resin ("EPICLON 850-S" manufactured by DIC Corporation; 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 nonvolatile content was 2% by mass.

[Production Example 8: Production of primer (B-8)]
A primer composition with a nonvolatile content of 2% by mass was prepared in the same manner as in Production Example 78, except that the amounts of aminotriazine novolac resin and 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. (B-8) was obtained.

[Production Example 9: Production of primer (B-9)]
A primer composition with a nonvolatile content of 2% by mass was prepared in the same manner as in Production Example 8, except that the amounts of aminotriazine novolak resin and 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. (B-9) was obtained.

[Production Example 10: Production of primer (B-10)]
To 47 parts by mass of the aminotriazine novolak resin obtained in Production Example 7 and 52 parts by mass of epoxy resin ("EPICLON 850-S" manufactured by DIC Corporation; bisphenol A type epoxy resin, epoxy group equivalent: 188 g/equivalent), anhydride was further added. After mixing 1 part by mass of trimellitic acid, the mixture was diluted and mixed with methyl ethyl ketone so that the nonvolatile content was 2% by mass to obtain a primer (B-10).

[Production Example 11: Production of primer (B-11)]
In a reaction vessel equipped with a stirrer, a reflux condenser, a nitrogen introduction tube, a thermometer, and a dropping funnel, 350 parts by mass of deionized water and a surfactant ("Latemul E-118B" manufactured by Kao Corporation: 25% by mass of active ingredient) were added. 4 parts by mass was added, and the temperature was raised to 70° C. while blowing nitrogen.

While stirring, 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 was placed in a reaction vessel. A portion of a monomer pre-emulsion obtained by mixing 4 parts by mass of a surfactant ("Aqualon KH-1025" manufactured by Daiichi Kogyo Seiyaku Co., Ltd.: active ingredient 25% by mass) and 15 parts by mass of deionized water ( 5 parts by mass) was added, followed by 0.1 part by mass of potassium persulfate, and polymerization was carried out for 60 minutes while maintaining the temperature inside the reaction vessel at 70°C.

Next, while maintaining the temperature inside the reaction vessel at 70°C, the remaining monomer pre-emulsion (114 parts by mass) and 30 parts by mass of an aqueous solution of potassium persulfate (active ingredient 1.0% by mass) were added dropwise separately. The mixture was added dropwise using a funnel over a period of 180 minutes. After the dropwise addition was completed, the mixture was stirred at the same temperature for 60 minutes.

The temperature in the reaction vessel is cooled to 40° C., and then deionized water is used so that the non-volatile content is 10.0% by mass, and then filtered through a 200 mesh filter cloth to be used in the present invention. A resin composition for a primer layer was obtained. Next, by adding water to this resin composition and diluting it, a primer (B-11) with a nonvolatile content of 5% by mass was obtained.

[Preparation Example 1: Preparation of silver particle dispersion]
By dispersing silver particles with 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 in which polyoxyethylene is added to polyethyleneimine as a dispersant, silver particles and dispersion are obtained. A dispersion containing the agent was prepared. Next, 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 copper etching solution]
A copper etching solution was prepared by mixing 37.5 g/L of sulfuric acid and 13.5 g/L of hydrogen peroxide with ion exchange water.

[Preparation example 3: Preparation of etching solution for silver]
A silver etching solution (1) was prepared by adding 2.6 parts by mass of acetic acid to 47.4 parts by mass of water, and further adding 50 parts by mass of 35% by mass hydrogen peroxide solution. The molar ratio of hydrogen peroxide and carboxylic acid (hydrogen peroxide/carboxylic acid) in this etching solution for silver (1) is 13.6. The content ratio of the mixture was 22.4% by mass.
[Preparation Example 4: Preparation of conductive polymer dispersion]
Polypyrrole/polyvinylpyrrolidone (PPy/PVP (SO ₄ ^2- )) colloid doped with sulfate ions was synthesized based on patent document (JP-A-2003-231991). 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 a 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 7.0 g of ammonium persulfate as an oxidizing agent and 32 g of sodium sulfate as a dopant were added to the resulting solution. .2 g was added, and water was further added to obtain a total amount of 1 L of an aqueous solution. To the obtained aqueous solution, 5 mL of pyrrole (manufactured by Tokyo Kasei Co., Ltd., special grade) was added, and the mixture was stirred at room temperature for about 12 hours to perform chemical oxidative polymerization to obtain a polymerization reaction mixture. By centrifuging this, a black deposit was obtained. The resulting deposit was washed several times with water and redispersed in 50 ml of water to obtain a 10 g/L (PPy/PVP(SO ₄ ^2- )) aqueous colloidal solution.

(Manufacture of laminates for semi-additive construction method)
(Example 1)
The silver particle dispersion obtained in Preparation Example 1 was applied to the surface of a polyimide film (Kapton 100EN-C manufactured by DuPont-Toray Co., Ltd.; thickness 25 μm), which is an insulating base material, using a small tabletop coater (RK Print). Coating was performed using "K Printing Profer" manufactured by Court Instrument Co., Ltd. so that the silver particle layer after drying was 0.5 g/m ² . Next, it was dried at 160° C. for 5 minutes using a hot air dryer. Furthermore, the film was turned over and coated with the silver particle dispersion obtained in Preparation Example 1 in the same manner as above so that the silver particle layer was 0.5 g/ ^m2 , and heated to 160°C using a hot air dryer. By drying the polyimide film for 5 minutes, silver particle layers were formed on both surfaces of the polyimide film. The film base material thus obtained was baked at 250° C. for 5 minutes, and conductivity of the silver particle layer was confirmed using a tester.

The polyimide film obtained above having conductive silver particle layers on both surfaces was fixed to a polyethylene frame and placed in an electroless copper plating solution (“Circuposit 6550” manufactured by Rohm & Haas Electronic Materials Co., Ltd.). was immersed for 10 minutes at 35°C to form an electroless copper plating film (thickness 0.2 μm) on both surfaces, and a silver particle layer ( A laminate for semi-additive construction in which a copper layer (M1) and a copper layer (M2) with a thickness of 0.2 μm were formed was produced.

(Example 2)
An electroless copper plating film with a thickness of 0.5 μm was formed on the silver particle layer (M1) in the same manner as in Example 1, except that the immersion time in the electroless copper plating solution was changed from 10 minutes to 25 minutes. By forming a semi-additive film, a conductive silver particle layer (M1) and a 0.5 μm thick copper layer (M2) are formed on both surfaces of the polyimide film that is the insulating base material (A). A laminate for construction method was produced.

(Example 3)
The laminate produced in Example 1, in which a conductive silver particle layer (M1) and a 0.2 μm thick copper layer were formed on both surfaces of the polyimide film, was fixed to a copper frame and electrolessly A copper plating layer is installed on the cathode, and a phosphorus-containing copper layer is used as an anode. By performing electrolytic plating at a current density of 2 A/dm2 for 4 minutes using Copper Gleam ST-901 (manufactured by Denshi Materials Co., Ltd.), silver particles were deposited on both surfaces of the polyimide film, which is the insulating base material (A). A laminate for semi-additive construction in which a layer (M1) and a 2 μm thick copper layer (M2) were formed was produced.

(Example 4)
Silver particle layers were formed on both surfaces of the polyimide film 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 , After baking at 250° C. for 5 minutes, conductivity of the silver particle layer was confirmed using a tester. The thus obtained polyimide film having conductive silver particle layers on both surfaces was fixed to a copper frame, the surface of the silver particle layer was placed on the cathode, and the phosphorus-containing copper was used as the anode, and the copper sulfate was Using an electrolytic plating solution (copper sulfate 60g/L, sulfuric acid 190g/L, chloride ion 50mg/L, additives (Rohm & Haas Electronic Materials Co., Ltd. Copper Gleam ST-901)), the current density was 2A. /dm2 for 4.5 minutes to form a silver particle layer (M1) and a 2 μm thick copper layer (M2) on both surfaces of the polyimide film that is the insulating base material (A). A laminate for semi-additive construction method was fabricated.

(Example 5)
The primer (B-1) obtained in Production Example 1 was applied to the surface of a polyimide film ("Kapton 100EN-C" manufactured by DuPont-Toray Co., Ltd., thickness 25 μm) using a small desktop coater (RK Print Coat Instrument Co., Ltd.). The film was coated to a dry thickness of 120 nm using a "K Printing Profer" manufactured by K.K. Co., Ltd., and then dried at 80°C for 5 minutes using a hot air dryer.Furthermore, the film was turned over, By applying the primer (B-1) obtained in Production Example 1 in the same manner as above so that the thickness after drying is 120 nm, and drying it at 80 ° C. for 5 minutes using a hot air dryer, Primer layers were formed on both surfaces of the polyimide film.

A conductive silver particle layer was prepared in the same manner as in Example 2, except that the insulating base material (A) was changed from polyimide film to polyimide with primer layers formed on both surfaces of the polyimide film obtained above. By forming an electroless copper plating film with a thickness of 0.5 μm on (M1), a primer layer (B) and a conductive silver particle layer are formed on both surfaces of the polyimide film that is the insulating base material (A). A laminate for semi-additive construction in which a copper layer (M1) and a copper layer (M2) with a thickness of 0.5 μm were formed was produced.

(Example 6)
In Example 5, the silver particle layer was changed from 0.5 g/m ² to 0.8 g/m ² and electrolytic copper plating was performed in the same manner as in Example 4, thereby forming an insulating base material ( A laminate for semi-additive construction was produced in which a primer layer (B), a conductive silver particle layer (M1), and a 2 μm thick copper layer (M2) were formed on both surfaces of the polyimide film A). did.

(Examples 7 to 22)
A semi-conductor was prepared in the same manner as in Example 6, except that the type of insulating base material, the type of primer used in the primer layer and its drying conditions, and the amount of silver in the silver particle layer were changed to those shown in Table 1 or 2. A laminate for additive construction was obtained.

(Example 23)
A conductive silver particle layer (M1) and a 0.5 μm thick copper layer (M2) were formed on both surfaces of the polyimide film, which was the insulating base material (A), produced in Example 2. A through hole with a diameter of 100 μm was formed in the laminate using a drill. The base material with through holes obtained in this way is passed through MacDiarmid's black hole process (conditioning - carbon adsorption treatment - etching) to adhere carbon to the surface of the through holes, and the carbon-adhered copper layer ( By removing M2) by etching using the sulfuric acid/hydrogen peroxide aqueous solution prepared in Preparation Example 2, the conductive silver particle layer (M1) on the polyimide film 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 that conductivity was ensured. In this way, the insulating base material (A) has conductive silver particle layers (M1) on both surfaces, and further has through holes connecting both surfaces of the insulating base material, and A laminate for semi-additive construction was obtained, the surface of which was made conductive by carbon.

(Example 24)
Same as Example 23 except that the laminate produced in Example 4 was used instead of the laminate produced in Example 2, and a through hole with a diameter of 50 μm was formed using a laser instead of a drill. The insulating base material (A) has a conductive silver particle layer (M1) on both surfaces thereof, and further has a through hole connecting both surfaces of the insulating base material, and the surface of the through hole is , a laminate for semi-additive construction method in which conductivity was ensured by carbon was obtained.

(Example 25)
A primer layer ( B) and a conductive silver particle layer (M1) in this order, and a through hole connecting both surfaces of the insulating base material, and the surface of the through hole was made conductive by carbon. A laminate for semi-additive construction was obtained.

(Example 26)
A primer layer ( B) and a conductive silver particle layer (M1) in this order, and a through hole connecting both surfaces of the insulating base material, and the surface of the through hole was made conductive by carbon. A laminate for semi-additive construction was obtained.

(Example 27)
A through hole with a diameter of 50 μm was formed in the laminate produced in Example 6 using a laser. The substrate with through holes thus obtained was immersed in a catalyst solution containing 1 g/l of palladium chloride, 1 ml/l of hydrochloric acid, and 1 g/l of dimethylthiourea at 25° C. for 3 minutes. Next, 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 to make the surfaces of the through holes conductive with palladium. After washing this base material with water, it was removed by etching using the sulfuric acid/hydrogen peroxide aqueous solution prepared in Preparation Example 2, thereby exposing the conductive silver particle layer (M1) on the polyimide film. 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 that conductivity was ensured. In this way, the insulating base material (A) has conductive silver particle layers (M1) on both surfaces, and further has through holes connecting both surfaces of the insulating base material, and A laminate for semi-additive construction was obtained, the surface of which was made conductive by palladium.

(Example 28)
A through hole with a diameter of 50 μm was formed in the laminate produced in Example 6 using a laser. The thus obtained substrate with through holes was immersed in the (PPy/PVP (SO ₄ ^2- )) aqueous colloid solution prepared in Preparation Example 4 for 2 minutes at room temperature, and colloid particles were formed on the surface of the through holes. was applied to make the surface of the through hole conductive with a conductive polymer. After washing this base material with water, it was removed by etching using the sulfuric acid/hydrogen peroxide aqueous solution prepared in Preparation Example 2, thereby exposing the conductive silver particle layer (M1) on the polyimide film. 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 that conductivity was ensured. In this way, the insulating base material (A) has conductive silver particle layers (M1) on both surfaces, and further has through holes connecting both surfaces of the insulating base material, and A laminate for semi-additive construction was obtained, the surface of which had electrical conductivity ensured by a conductive polymer.

(Manufacture of printed wiring boards)
(Example 29, 30)
In Examples 23 and 24, the same as Examples 23 and 24 except that the through holes were formed at the connection position to the back surface GND of the transmission characteristic evaluation terminal of a microstrip line with a wiring length of 100 mm and an impedance of 50 Ω. The insulating base material (A) has a conductive silver particle layer (M1) on both surfaces thereof, and further has a through hole connecting both surfaces of the insulating base material, and the surface of the through hole is , a laminate for semi-additive construction method in which conductivity was ensured by carbon was obtained.

On top of the silver particle layer (M1) obtained in this way, a dry film resist (“Fotech RD-1225” manufactured by Hitachi Chemical Co., Ltd.; resist film thickness 25 μm) was pressure-bonded at 100°C using a roll laminator. Next, using a direct exposure digital imaging device ("Nuvogo 1000R" manufactured by Orbottech), a microstrip line pattern with a wiring length of 100 mm and an impedance of 50 Ω was formed on the resist, and the terminal of the through hole part connected to GND for the measurement probe was formed on the resist. The pad pattern was exposed. Next, by performing development using a 1% by mass sodium carbonate aqueous solution, a pattern resist in which a microstrip line pattern and probe terminal pad portions have been removed is formed on the silver particle layer (M1), and the silver on the polyimide film is developed. 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 as a cathode, and an electrolytic plating solution containing copper sulfate (copper sulfate 60 g/L, sulfuric acid 190 g/L, chlorine ion The resist was removed from the microstrip by electrolytic plating at a current density of 2 A/dm2 for 41 minutes using 50 mg/L and an additive (Copper Gleam ST-901 manufactured by Rohm & Haas Electronic Materials Co., Ltd.). A conductive layer (M3) of a circuit pattern with a thickness of 18 μm was formed by electrolytic copper plating on the pattern and the probe terminal pad portion.Then, the film on which the copper metal pattern was formed was subjected to 3% by mass hydroxide at 50°C. The pattern resist was peeled off by immersion in a sodium aqueous solution.

Next, the film obtained above was immersed in the silver etching solution obtained in Preparation Example 3 at 25° C. for 30 seconds to remove the silver particle layer other than the conductive layer pattern and obtain a printed wiring board. Ta. The cross-sectional shape of the circuit forming part (microstrip line and probe terminal part) of the fabricated printed wiring board shows a rectangular shape with no reduction in wiring height and wiring width and no undercut, and is smooth. This was the surface conductive layer (M3).

(Example 31, 32)
In Examples 25 and 26, the same as Examples 25 and 26 except that the through holes were formed at the connection position to the back surface GND of the transmission characteristic evaluation terminal of a microstrip line with a wiring length of 100 mm and an impedance of 50 Ω. The insulating base material (A) has a primer layer (B) and a conductive silver particle layer (M1) on both surfaces in this order, and further has a through hole connecting both surfaces of the insulating base material. A laminate for semi-additive construction was obtained in which the surface of the through hole had conductivity ensured by carbon.

Thereafter, in the same manner as in Examples 29 and 30, a microstrip line with a wiring length of 100 mm, an impedance of 50 Ω, and a copper thickness of 18 μm and a conductive layer (M3) with a probe terminal pattern were provided on the silver particle layer (M1). A printed wiring board was created. The cross-sectional shape of the produced printed wiring board circuit forming part was a rectangular shape with no reduction in wiring height and wiring width and no undercut, and was a conductive layer (M3) with a smooth surface.

(Example 33)
In Example 27, the insulation was made in the same manner as in Example 27, except that the through hole was designed to be connected to the back surface GND of the transmission characteristic evaluation terminal of a microstrip line with a wiring length of 100 mm and an impedance of 50Ω. A primer layer (B) and a conductive silver particle layer (M1) are provided on both surfaces of the insulating base material (A) in this order, and a through hole is provided to connect both surfaces of the insulating base material. A laminate for semi-additive construction was obtained in which the surface of the pores had electrical conductivity ensured by palladium.

Thereafter, in the same manner as in Examples 29 and 30, a microstrip line with a wiring length of 100 mm, an impedance of 50 Ω, and a copper thickness of 18 μm and a conductive layer (M3) with a probe terminal pattern were provided on the silver particle layer (M1). A printed wiring board was created. The cross-sectional shape of the produced printed wiring board circuit forming part was a rectangular shape with no reduction in wiring height and wiring width and no undercut, and was a conductive layer (M3) with a smooth surface.

(Example 34)
In Example 28, the insulation was made in the same manner as in Example 28, except that the through hole was designed to be connected to the back surface GND of the transmission characteristic evaluation terminal of a microstrip line with a wiring length of 100 mm and an impedance of 50Ω. A primer layer (B) and a conductive silver particle layer (M1) are provided on both surfaces of the insulating base material (A) in this order, and a through hole is provided to connect both surfaces of the insulating base material. A laminate for semi-additive construction in which the surface of the pores had electrical conductivity ensured by the conductive polymer was obtained.

Thereafter, in the same manner as in Examples 29 and 30, a microstrip line with a wiring length of 100 mm, an impedance of 50 Ω, and a copper thickness of 18 μm and a conductive layer (M3) with a probe terminal pattern were provided on the silver particle layer (M1). A printed wiring board was created. The cross-sectional shape of the produced printed wiring board circuit forming part was a rectangular shape with no reduction in wiring height and wiring width and no undercut, and was a conductive layer (M3) with a smooth surface.

(Comparative example 1)
Instead of using a polyimide film with silver particle layers formed on both sides, we used a commercially available 25 μm thick polyimide-based FCCL (“Yupiceru N-BE1310YSB” manufactured by Ube Eximo Co., Ltd.) that has a 3 μm thick roughened copper foil as a plating base layer on both sides. Through holes penetrating both sides were formed in the same manner as in Examples 29 to 33, except for using By attaching carbon and removing the carbon-attached copper foil surface by etching using the sulfuric acid/hydrogen peroxide aqueous solution prepared in Preparation Example 2, on both surfaces of the insulating base material (A), A base material was obtained that had a copper foil, further had a through hole connecting both surfaces of the insulating base material, and the surface of the through hole had carbon to ensure conductivity.

Thereafter, in the same manner as in Examples 29 to 33, except that a pattern resist was formed on the surface of the copper foil instead of the surface of the silver particle layer (M1), a 18 μm thick layer of copper was formed on the plating base layer of the copper foil. A conductor circuit layer of a microstrip line and a probe terminal pad pattern was formed.

Next, when the copper seeds were removed by immersion in a sulfuric acid/hydrogen peroxide flash etching solution used for copper seed etching, the conductive layer (M3) of the microstrip line was etched to a film thickness of about 3 μm. As the thickness became thinner, the wiring width also decreased by about 6 μm, and the cross-sectional shape could no longer maintain a rectangular shape but became a "trapezoid" shape. Furthermore, the surface of the copper conductive layer was roughened by etching and its smoothness decreased.

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

Next, when the copper seed was removed by immersion in a sulfuric acid/hydrogen peroxide flash etching solution used for copper seed etching, the conductive layer (M3) of the microstrip line was etched to a film thickness of approximately 1 μm. As the thickness became thinner, the wiring width also decreased by 2 μm or more, and the cross-sectional shape could no longer maintain a rectangular shape and became a "trapezoid" shape. Furthermore, the surface of the copper conductive layer was roughened by etching and its smoothness decreased. Further, in areas other than the conductive layer (M3) pattern, only the copper layer was removed, and the nickel/chromium layer remained without being removed.

[Checking whether there is an undercut or not and the cross-sectional shape of the wiring section]
The cross-section of the comb-teeth electrode portion of the printed wiring board obtained above was observed under a scanning electron microscope (JSM7800 manufactured by JEOL Ltd.) at a magnification of 500 to 10,000 times, and the presence or absence of undercuts and comb-teeth electrodes were observed. The cross-sectional shape of the tooth electrode part was confirmed.

By observing the wiring surface of the manufactured printed wiring board with a laser microscope (manufactured by Keyence Corporation, VK-9710), the surface roughness of the wiring surface was confirmed, and if Rz was 3 μm or less, it was considered smooth (smoothness). :〇), and those with Rz exceeding 3 μm were evaluated as not smooth (smoothness: ×). In addition, when the difference between the designed width of the wiring using the resist used for wiring formation and the top surface width of the formed wiring was 2 μm or less, side etching was suppressed and the rectangular shape could be maintained (rectangularity: 〇). If the difference exceeds 2 μm, it was evaluated that the rectangular shape could not be maintained (short formation: ×), and Examples, Comparative Examples, and evaluation results are shown in Tables 1 to 3.

1: Insulating base material 2: Silver particle layer 3: Copper layer 4: Primer layer 5: Palladium, conductive polymer, carbon 6: Through hole (through hole)
7: Palladium, conductive polymer, carbon 8: Pattern resist 9: Conductive layer (electrolytic copper plating layer)
(a) Laminated body for semi-additive construction method (configuration of claim 1)
(b) Step 1: Through-hole formation (c) Step 2: Application of catalyst for electroless silver plating (d) Step 3: Exposure of conductive silver particle layer (e) Step 4: By electroless silver plating Silver layer conductivity in through holes (f) Step 5: Resist pattern formation (g) Step 6: Conductive layer formation by electrolytic copper plating (h) Step 7: Pattern resist peeling (i) Step 7: Silver seed removal

Claims (4)

A silver particle layer (M1) and a copper layer (M2) are sequentially laminated on both surfaces of the insulating base material (A), and the layer thickness of the copper layer (M2) is 0.1 μm to 2 μm. Step 1 of forming a through hole penetrating both sides of the laminate;
Step 2 of applying palladium, a conductive polymer, or carbon to the surface of the base material having the through hole to make the surface of the through hole electrically conductive;
Step 3 of etching away the entire copper layer (M2) to expose the conductive silver particle layer (M1);
1. A method for producing a laminate for semi-additive construction method, comprising: 2. The method for producing a laminate for semi-additive construction according to claim 1, further comprising laminating a primer layer (B) between the insulating base material (A) and the silver particle layer (M1). A silver particle layer (M1) and a copper layer (M2) are sequentially laminated on both surfaces of the insulating base material (A), and the layer thickness of the copper layer (M2) is 0.1 μm to 2 μm. Step 1 of forming a through hole penetrating both sides of the laminate;
Step 2 of applying palladium, a conductive polymer, or carbon to the surface of the base material having the through hole to make the surface of the through hole electrically conductive;
Step 3 of etching away the entire copper layer (M2) to expose the conductive silver particle layer (M1);
Step 4 of forming a pattern resist on the conductive silver particle layer (M1);
Step 5 of electrically connecting both sides of the base material and forming a conductive layer (M3) of a circuit pattern by electrolytic copper plating;
Step 6 of peeling off the pattern resist and removing the silver particle layer (M1) in the non-circuit pattern forming area with an etching solution
A method for manufacturing a printed wiring board, comprising: The method for manufacturing a printed wiring board according to claim 3, further comprising a primer layer (B) between the insulating base material (A) and the silver particle layer (M1).

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