JP2015204410A - Metal base printed wiring board and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a metal base printed wiring board with wiring, which is excellent in heat dissipation properties, and can be used for various applications as a substrate on which a semiconductor element, such as an LED lamp, generating heat is mounted, and a method for manufacturing the metal base printed wiring board.SOLUTION: A metal base printed wiring board is used, the metal base printed wiring board comprising a polymer layer (A), a plating substrate layer (B) formed by using a conductive ink, and a metal plating layer (C) which are sequentially laminated on a diamond-like carbon layer of a base material having a diamond-like carbon layer formed on a metal base material.

Description

  The present invention relates to a metal-based printed wiring board and a method for manufacturing the same.

  2. Description of the Related Art In recent years, LED (Light Emitting Diode) lamps, which are semiconductor elements, have been used in various fields, and are used in a wide range of applications from 10 mA to 1 A or more. Those driven at a low current are used for indicators and displays, and those driven at a high current are mainly used as a light source for lighting fixtures. The LED lamp may need to operate at a high temperature depending on the usage conditions (mounting board, mounting density, environmental temperature, etc.). Especially for high-power type LED lamps, the LED lamp alone generates a large amount of heat, so the influence of heat. Becomes larger. Therefore, in order to fully draw out the performance of the LED lamp, the heat dissipation design of the LED lamp is essential.

  As one of the heat radiation design techniques, a substrate, a diamond-like carbon (hereinafter referred to as “DLC”) film having excellent thermal conductivity formed on the substrate, a DLC film formed on the DLC film, There has been proposed an optical print head comprising a thin film thinner than a film thickness and a semiconductor thin film having a semiconductor element and bonded onto the thin film (see, for example, Patent Document 1).

  In the above optical print head, a thin film having high polarizability is formed on a DLC film provided on a substrate so that the semiconductor thin film is bonded to the surface of the opposing semiconductor thin film. There are some which have an attractive force due to intermolecular force (particularly van der Waals force or hydrogen bonding force) between the surface and high bonding strength. However, in order to develop the intermolecular force, it is necessary to bring the materials of the highly polarizable thin film on the DLC film and the semiconductor film close to each other very closely. Since a technique for forming a smooth surface is required, there is a drawback that versatility is poor in that it is restricted by the shape of the base material and is limited to a material that can form a flat surface.

JP 2010-56194 A

  The problem to be solved by the present invention is to provide a metal-based printed wiring board having wiring that is excellent in heat dissipation and can be used for various applications as a substrate for mounting a heat-generating semiconductor element such as an LED lamp. is there. Furthermore, it is providing the manufacturing method of the said metal base printed wiring board.

  As a result of diligent research to solve the above problems, the present inventors have provided a polymer layer (A) as an adhesion layer on a metal substrate provided with a DLC layer, and a plating underlayer (B) thereon. A metal base printed wiring board in which a metal wiring is formed by forming a base of a wiring pattern with a conductive ink and applying a metal plating to the plating base layer (B) mounts a semiconductor element that generates heat such as an LED lamp. It was found that the substrate can be used in various applications and has excellent heat dissipation, and the present invention has been completed.

  That is, the present invention relates to a polymer layer (A) and a plating base layer (B) formed using a conductive ink on a diamond-like carbon layer of a base material provided with a diamond-like carbon layer on a metal base material. And a metal plating layer (C) are sequentially laminated, and a metal base printed wiring board and a method for manufacturing the same are provided.

  The metal-based printed wiring board according to the present invention has a substrate surface that is not flat but uneven as compared to a metal substrate in which a DLC layer is provided as an insulating layer with excellent heat dissipation on a metal substrate with excellent heat dissipation. Even in this case, a wiring having excellent adhesion can be formed. Therefore, for example, as a substrate for mounting a semiconductor element that generates heat, such as an LED lamp, a metal-based printed wiring used for LED lighting for houses, LED lighting for automobile interiors, LED lamps for automobile headlamps, outdoor lamps, etc. It can be used as a plate. Further, it can be suitably used as a metal-based printed wiring board used in surface-mounted LEDs and chip-on-board LEDs having a structure in which a large number of LED chips are directly mounted on a substrate. On the other hand, the metal-based printed wiring board of the present invention can also be used for applications other than LED lamps. For example, as an electronic device for automobiles such as transistors and diode modules, steppings and servo motors as industrial electronic devices, electric power steering Controllers, DC-DC converters for hybrid electric vehicles, power supplies for communications, power supplies for OA equipment, AC-DC converters for semiconductor devices, DC-DC converters, household appliances such as audio amplifiers, inverters for air conditioners, etc. It can also be used as a metal-based printed wiring board.

FIG. 1 shows a cross section of a metal-based printed wiring board produced in Example 1. FIG. 2 shows a cross section of the metal-based printed wiring board produced in Example 2.

  The metal-based printed wiring board of the present invention is a plating formed using a polymer layer (A) and a conductive ink on a diamond-like carbon layer of a base material provided with a diamond-like carbon layer on a metal base material. A base layer (B) and a metal plating layer (C) are sequentially laminated.

  As the metal substrate, when the metal base printed wiring board of the present invention is used for an application where bending flexibility is required, it is preferable to use a flexible and flexible metal thin film. Specifically, it is preferable to use a sheet-like metal.

  When the shape of the metal substrate is a film or sheet, the thickness of the film or sheet is usually preferably about 1 to 5,000 μm, and about 1 to 300 μm. More preferably. Moreover, when using the metal base printed wiring board of this invention for the thing by which a flexibility is calculated | required, it is preferable to use the film-form thing of thickness about 1-200 micrometers as said metal base material.

  In addition, the metal base material has improved adhesion to the wiring described later, the plating base layer (B) that is the base of the wiring, and the polymer layer (A) provided to provide adhesion to the lower part of the metal base material. Therefore, as necessary, the surface was treated by washing with water, organic solvent, surfactant, etc., surface roughening by mechanical polishing, chemical etching, etc., pretreatment with silane coupling agent, etc. Things can be used.

  In the present invention, a DLC layer is provided as an insulating layer on the metal substrate. The DLC layer is formed on a metal substrate by forming a film from solid carbon using sputtering or cathodic arc discharge (PVD method), or by converting a hydrocarbon gas such as methane, ethylene, or benzene into plasma. It can be formed by a method (CVD method) or a method combining these processes.

  Since the DLC layer functions as an insulating layer of the metal base printed wiring board of the present invention, the film thickness is preferably in the range of 0.05 to 10 μm. Furthermore, the film thickness of the DLC layer is more preferably in the range of 0.05 to 3 μm from the viewpoint of excellent heat dissipation.

  The surface of the DLC layer is further improved in adhesion with the polymer layer (A) described later, for example, a plasma discharge treatment method such as a corona discharge treatment method; a dry treatment method such as an ultraviolet treatment method; water Surface treatment may be performed by a wet treatment method using an acidic or alkaline chemical solution, an organic solvent, or the like.

  Next, in the present invention, a polymer layer (A) is provided on the DLC layer in order to provide adhesion to the wiring described later. Examples of the polymer forming the polymer layer (A) include urethane resin, vinyl resin, acrylic resin, urethane-acrylic composite resin, epoxy resin, imide resin, amide resin, melamine resin, phenol resin, polyvinyl alcohol, Various resins such as polyvinylpyrrolidone can be mentioned.

  Among the resins used as the polymer, urethane resin, acrylic resin, urethane-acrylic composite resin are preferable, urethane resin having polyether structure, urethane resin having polycarbonate structure, urethane resin having polyester structure, acrylic resin, and One or more resins selected from the group consisting of urethane-acrylic composite resins are more preferable. A urethane-acrylic composite resin is more preferable because a wiring pattern having excellent adhesion and conductivity can be obtained.

  Moreover, when the conductive ink for forming the plating underlayer (B) described later contains the compound (b1) having a reactive functional group [Y], the high polymer layer (A) is formed. The molecule is preferably a compound (a1) having a functional group [X] having reactivity with the reactive functional group [Y]. Examples of the compound (a1) having the reactive functional group [X] include an amino group, an amide group, an alkylolamide group, a carboxyl group, an anhydrous carboxyl group, a carbonyl group, an acetoacetyl group, an epoxy group, and an alicyclic epoxy. Group, oxetane ring, vinyl group, allyl group, (meth) acryloyl group, (blocked) isocyanate group, (alkoxy) silyl group-containing compound, silsesquioxane compound and the like.

  In particular, the compound (b1) having the reactive functional group [Y] in the conductive ink for forming the plating underlayer (B) described later is a compound (b1) having a basic nitrogen atom-containing group described later. In this case, the polymer that forms the polymer layer (A) includes, as the reactive functional group [X], a carboxyl group, a carbonyl group, an acetoacetyl group, an epoxy group, an alicyclic epoxy group, an alkylolamide group, an isocyanate. Group, vinyl group, (meth) acryloyl group, and allyl group are preferable because adhesion between the finally obtained metal layer and the second insulating protective layer can be improved.

  The polymer layer (A) may be provided as a thin film on the entire surface of the DLC layer, but the polymer layer (A) is finally used from the viewpoint of maximizing the heat dissipation of the metal substrate. It is preferable that the DLC layer is exposed in the lower part of the wiring pattern obtained in the same manner, and that the part other than the wiring is exposed. In other words, the polymer layer (A) has a plating base layer (B) described later. It is preferable to form with the same pattern.

  When the polymer for forming the polymer layer (A) is applied to the surface of the DLC layer, the polymer is dissolved or dispersed in a solvent. Examples of the application method include a gravure method, a coating method, a screen method, a roller method, a rotary method, and a spray method.

  Examples of the method for forming the polymer layer (A) in the same pattern as the plating base layer (B) include a method of forming a pattern by printing a polymer ink for forming the polymer layer (A). Examples of the printing method include an inkjet printing method, a reverse printing method, a flexographic printing method, a screen printing method, a gravure printing method, and a gravure offset printing method. Among these printing methods, an inkjet printing method that can easily cope with a pattern change is preferable.

  In the ink jet printing method, what is generally called an ink jet printer can be used. Specific examples of the ink jet printer include, for example, “Konica Minolta EB100, XY100” (manufactured by Konica Minolta IJ Co., Ltd.), “Dimatics Material Printer DMP-3000, DMP-2831” (manufactured by Fuji Film Co., Ltd.), and the like. Can be mentioned.

  Moreover, when producing a high-definition pattern of the polymer layer (A), a reverse printing method that is excellent in fine line printing accuracy is preferable.

  As the reversal printing method, a letterpress reversal printing method and an intaglio reversal printing method are known.For example, the conductive ink is applied to the surface of various blankets, and is brought into contact with a plate from which a non-image portion protrudes. The pattern is formed on the surface of the blanket or the like by selectively transferring the conductive ink corresponding to the image area to the surface of the plate, and then the pattern is formed on the second insulating protective layer ( And a method of transferring to the surface).

  As a method of removing the solvent contained in the coating layer after coating or printing the polymer forming the polymer layer (A) on the surface of the DLC layer, for example, drying using a dryer, A method of volatilizing the solvent is common. The drying temperature is preferably set to a temperature within which the solvent can be volatilized and does not adversely affect the metal substrate or the DLC layer as a support.

  The thickness of the polymer layer (A) formed using the polymer is preferably in the range of 5 to 5,000 nm because the adhesion between the DLC layer and the plating underlayer (B) described later can be further improved. The range of 10 to 200 nm is more preferable from the viewpoint of excellent heat dissipation of the finally obtained wiring.

  Next, in this invention, in order to form a wiring pattern, the plating base layer (B) formed using the conductive ink is used. Conductive ink is used to create a pattern as the base of the plating layer, but it has excellent adhesion to the metal plating layer formed on it and plating deposition during metal plating. (B2) is preferably one containing metal nanoparticles. Furthermore, since the said metal nanoparticle is excellent in adhesiveness with the said polymer layer (A), it is preferable that it is the metal nanoparticle disperse | distributed with the polymer dispersing agent.

  The polymer dispersant is preferably a polymer having a functional group that coordinates to metal nanoparticles. Examples of the functional group include a carboxyl group, an amino group, a cyano group, an acetoacetyl group, a phosphorus atom-containing group, a thiol group, a thiocyanato group, and a glycinato group.

  Examples of the metal nanoparticles include transition metals or compounds thereof, and ionic transition metals are preferable among the transition metals. Examples of the ionic transition metal include metals such as copper, silver, gold, nickel, palladium, platinum, and cobalt, and composites of these metals. These metal nanoparticles can be used alone or in combination of two or more. Among these metal nanoparticles, silver nanoparticles are preferable from the viewpoints of handling problems such as oxidative degradation and cost.

  Moreover, the electroconductive substance (b2) contained in the said electroconductive ink can replace with a metal nanoparticle, and can also use a plating nucleating agent. In that case, an oxide of the transition metal, a metal whose surface is coated with an organic substance, or the like can be used. These plating nucleating agents can be used alone or in combination of two or more.

  The transition metal oxide is usually in an inactive (insulating) state. For example, the metal is exposed by treatment with a reducing agent such as dimethylaminoborane to impart activity (conductivity). be able to.

  In addition, examples of the metal whose surface is coated with the organic substance include those in which a metal is contained in resin particles (organic substance) formed by an emulsion polymerization method or the like. These are usually in an inactive (insulating) state. However, for example, by removing the organic substance using a laser or the like, the metal can be exposed to impart activity (conductivity).

  As the conductive substance (b2), a particulate material having an average particle diameter of about 1 to 100 nm is preferably used, and an average particle diameter of 1 to 50 nm is preferably used. Compared to the case where a conductive substance having a particle size is used, it is more preferable because a fine conductive pattern can be formed and the resistance value after firing described later can be further reduced. In the present invention, the average particle diameter is a volume average value measured by a dynamic light scattering method after diluting the conductive substance (b2) with a dispersion good solvent. For this measurement, “Nanotrack UPA” manufactured by Microtrack Corporation can be used.

  When the polymer layer (A) is a polymer having the reactive functional group [X], the conductive ink for forming the plating base layer (B) includes the polymer layer (A) and In order to further improve the adhesion with the plating underlayer (B), those containing the compound (b1) having a reactive functional group [Y] and the conductive substance (b2) are preferable.

  The reactive functional group [Y] possessed by the compound (b1) is involved in bonding with the reactive functional group [X]. Specific examples include an amino group, an amide group, an alkylolamide group, Carboxyl group, anhydrous carboxyl group, carbonyl group, acetoacetyl group, epoxy group, alicyclic epoxy group, oxetane ring, vinyl group, allyl group, (meth) acryloyl group, (blocked) isocyanate group, (alkoxy) silyl group, etc. The compound which has these, a silsesquioxane compound, etc. are mentioned.

  In particular, in order to further improve the adhesion to the polymer layer (A), the reactive functional group [Y] is preferably a basic nitrogen atom-containing group.

  Examples of the basic nitrogen atom-containing group in the compound having a basic nitrogen atom-containing group include an imino group, a primary amino group, and a secondary amino group.

  Further, by using the compound (b1) having a plurality of basic nitrogen atom-containing groups in one molecule, one of the basic nitrogen atom-containing groups is formed when the pattern of the plating base layer (B) is formed. , Involved in the binding with the reactive functional group [X] of the polymer forming the polymer layer (A), the other being the conductive material such as silver contained in the plating base layer (B) This is preferable because it contributes to the interaction with the substance (b2) and can further improve the adhesion between the metal plating layer to be finally obtained and the DLC layer.

  Since the compound (b1) having a basic nitrogen atom-containing group can further improve the dispersion stability of the conductive substance (b2) and the adhesion to the second insulating protective layer described later, the polyalkyleneimine, or A polyalkyleneimine having a polyoxyalkylene structure containing an oxyethylene unit is preferred.

  The polyalkyleneimine having the above may be a linear bond of polyethyleneimine and polyoxyalkylene, and the polyoxyalkylene is present in the side chain of the main chain composed of polyethyleneimine. May be grafted.

  Specific examples of the polyalkyleneimine having the polyoxyalkylene structure include a block copolymer of polyethyleneimine and polyoxyethylene, and an addition reaction of ethylene oxide with a part of imino group present in the main chain of polyethyleneimine. Examples thereof include those obtained by introducing a polyoxyethylene structure, those obtained by reacting an amino group possessed by polyalkyleneimine, a hydroxyl group possessed by polyoxyethylene glycol, and an epoxy group possessed by an epoxy resin.

  Examples of the commercially available polyalkyleneimine include “PAO2006W”, “PAO306”, “PAO318”, “PAO718” and the like 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.

  When the reactive functional group [Y] of the compound (b1) is a carboxyl group, an amino group, a cyano group, an acetoacetyl group, a phosphorus atom-containing group, a thiol group, a thiocyanato group, a glycinato group, or the like, Since the functional group also functions as a functional group that coordinates with the metal nanoparticles, the compound (b1) can also be used as a polymer dispersant for the metal nanoparticles.

  The conductive ink preferably has an appropriate viscosity using a solvent in order to impart printability in various printing methods described later. Examples of the solvent include aqueous media such as distilled water, ion-exchanged water, pure water, and ultrapure water; and organic solvents such as alcohol solvents, ether solvents, ketone solvents, and ester solvents.

  Examples of the alcohol solvent or ether solvent include methanol, ethanol, n-propanol, isopropyl alcohol, n-butanol, isobutyl alcohol, sec-butanol, tert-butanol, heptanol, hexanol, octanol, nonanol, decanol, undecanol, and dodecanol. , Tridecanol, tetradecanol, pentadecanol, stearyl alcohol, allyl alcohol, cyclohexanol, terpineol, terpineol, dihydroterpineol, 2-ethyl-1,3-hexanediol, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, Propylene glycol, dipropylene glycol, 1,2-butanediol, 1, -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, tetra Ethylene glycol monobutyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, tripropylene glycol monomethyl ether, propylene glycol monopropyl ether, dipropylene glycol monopropyl ether, propylene glycol monobutyl ether, dipropylene glycol monobutyl ether, tripropylene Recall mono-butyl ether, and the like.

  Examples of the ketone solvent include acetone, cyclohexanone, methyl ethyl ketone, and the like. Examples of the ester solvent include ethyl acetate, butyl acetate, 3-methoxybutyl acetate, 3-methoxy-3-methyl-butyl acetate and the like. Furthermore, 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 nonpolar solvents such as octane, nonane, decane, dodecane, tridecane, tetradecane, cyclooctane, xylene, mesitylene, ethylbenzene, dodecylbenzene, tetralin, and trimethylbenzenecyclohexane. Can be used in combination with other solvents as necessary. Furthermore, a solvent such as mineral spirit or solvent naphtha, which is a mixed solvent, can be used in combination.

  The conductive ink can be produced, for example, by mixing the polymer dispersant, the conductive substance, and, if necessary, the solvent. Specifically, an ion solution of the conductive substance prepared in advance is added to a medium in which a compound having a polyalkyleneimine chain, a hydrophilic segment, and a hydrophobic segment is dispersed, and the metal ions are reduced. Can be manufactured by.

  In addition, the conductive ink may contain a surfactant, an erasing agent, or the like, if necessary, in order to improve the dispersion stability of the conductive substance in a solvent such as an aqueous medium or an organic solvent and the wettability to the coated surface. Foaming agents, rheology modifiers, etc. may be added.

  In the present invention, the conductive ink is printed on the polymer layer (A) to form a pattern comprising the plating base layer (B). As a method for printing the conductive ink, for example, inkjet printing is used. Method, reverse printing method, flexographic printing method, screen printing method, gravure printing method, gravure offset printing method and the like. Among these printing methods, an inkjet printing method that can easily cope with a pattern change is preferable.

  In the ink jet printing method, what is generally called an ink jet printer can be used. Specifically, “Konica Minolta EB100, XY100” (manufactured by Konica Minolta IJ Co., Ltd.), “Dimatics Material Printer DMP-3000, DMP-2831” (manufactured by Fuji Film Co., Ltd.) and the like can be mentioned.

  Further, in the case of producing a high-definition metal layer pattern, a reversal printing method excellent in fine line printing accuracy is preferable.

  As the reversal printing method, a letterpress reversal printing method and an intaglio reversal printing method are known.For example, the conductive ink is applied to the surface of various blankets, and is brought into contact with a plate from which a non-image portion protrudes. The pattern is formed on the surface of the blanket or the like by selectively transferring the conductive ink corresponding to the image area to the surface of the plate, and then the pattern is formed on the second insulating protective layer ( And a method of transferring to the surface).

  Next, the baking step performed after applying the conductive ink to form a pattern as a plating base with the conductive ink is to adhere and bond the conductive substances contained in the conductive ink. In order to form a plating base pattern having conductivity. The firing is preferably performed at a temperature range of 80 to 300 ° C. for about 1 to 200 minutes. Here, in order to obtain a plating base pattern having excellent adhesion to the second insulating protective layer, it is more preferable to set the firing temperature in the range of 100 to 200 ° C.

  Although the firing may be performed in the air, part or all of the firing step may be performed in a reducing atmosphere in order to prevent all of the conductive material from being oxidized.

  Moreover, the said baking process can be performed using oven, a hot-air drying furnace, an infrared drying furnace, laser irradiation, a microwave, light irradiation (flash irradiation apparatus) etc., for example.

  The pattern consisting of the plating base layer (B) formed using the conductive ink by the method as described above contains a conductive substance in the range of 80 to 99.9% by mass in the pattern, It is preferable that the polymer dispersant is contained in the range of 0.1 to 20% by mass.

  The thickness of the plating base layer (B) formed using the conductive ink is preferably in the range of 50 to 2,000 nm because a conductive pattern having low resistance and excellent conductivity can be formed.

  Examples of the method for forming the metal plating layer (C) constituting the wiring of the present invention include wet plating methods such as an electrolytic plating method and an electroless plating method, and a plating layer obtained by combining two or more of these plating methods. May be formed.

  Among the plating methods, since the adhesion between the pattern of the plating base layer (B) and the plating layer formed by the plating method is further improved, and a pattern having excellent conductivity is obtained, electrolytic plating is performed. A wet plating method such as an electroless plating method or an electroless plating method is preferable, and an electrolytic plating method is more preferable because of excellent productivity and mechanical properties of the obtained metal film.

  In the electroless plating method, for example, an electroless plating solution is brought into contact with a conductive material constituting the pattern of the plating base layer (B), thereby depositing copper metal contained in the electroless plating solution. This is a method of forming an electroless plating layer (film) comprising a film.

  Examples of the electroless plating solution include those containing copper, a reducing agent, and a solvent such as an aqueous medium or an organic solvent.

  Examples of the reducing agent include dimethylaminoborane, hypophosphorous acid, sodium hypophosphite, dimethylamine borane, hydrazine, formaldehyde, sodium borohydride, phenol and the like.

  In addition, as the electroless plating solution, if necessary, monocarboxylic acids such as acetic acid and formic acid; dicarboxylic acid compounds such as malonic acid, succinic acid, adipic acid, maleic acid, and fumaric acid; malic acid, lactic acid, glycol Hydroxycarboxylic acid compounds such as acid, gluconic acid and citric acid; amino acid compounds such as glycine, alanine, iminodiacetic acid, arginine, aspartic acid and glutamic acid; iminodiacetic acid, nitrilotriacetic acid, ethylenediaminediacetic acid, ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, etc. Containing complexing agents such as organic acids such as aminopolycarboxylic acid compounds or soluble salts of these organic acids (sodium salts, potassium salts, ammonium salts, etc.), amine compounds such as ethylenediamine, diethylenetriamine, and triethylenetetramine. It can be used for.

  The electroless plating solution is preferably used in the range of 20 to 98 ° C.

  In the electrolytic plating method, for example, the metal constituting the plating base layer (B) or the surface of the electroless plating layer (coating) formed by the electroless treatment is energized with an electrolytic plating solution in contact with the surface. Thus, a metal such as copper contained in the electrolytic plating solution is converted into a conductive material constituting the plating base layer (B) placed on the cathode or the electroless plating layer (coating film) formed by the electroless treatment. ) To form an electrolytic plating layer (metal coating).

  Examples of the electrolytic plating solution include those containing copper sulfide, sulfuric acid, and an aqueous medium. Specifically, what contains copper sulfate, sulfuric acid, and an aqueous medium is mentioned.

  The electrolytic plating solution is preferably used in the range of 20 to 98 ° C.

  As the plating method, an electroplating method is preferable because workability is good without using a highly toxic substance. Electrolytic plating is preferable because it can reduce the plating time and control the film thickness of the plating as compared with electroless plating.

  The plating layer may be formed by laminating another metal plating layer on the plating layer. For example, when a nickel plating layer, a gold plating layer, or a tin plating layer is provided on the copper plating layer, the copper plating layer is provided. Prevents oxidative deterioration and corrosion of the surface.

  The thickness of the metal plating layer (C) formed by the plating method is preferably in the range of 0.2 to 30 μm because it is excellent in conductivity as a conductive layer. Moreover, when forming a plating layer by an electroplating method, the thickness of the layer can be adjusted by controlling the processing time in a plating process, a current density, the usage-amount of the additive for plating, etc.

  Examples of the metal species of the metal plating layer (C) formed by the plating method include copper, nickel, gold, and silver. From the viewpoint of wiring conductivity and cost, copper is preferably the main component. .

  Next, the manufacturing method of the metal base printed wiring board of this invention is described. As a manufacturing method, for example, the polymer is applied or printed on a metal substrate on which a DLC layer is formed, and dried to form a polymer layer (A). A conductive ink containing metal nanoparticles is printed on the substrate, dried to form a pattern of the plating base layer (B), and electrolytic plating or electroless plating is performed on the pattern of the plating base layer (B). The method of forming a metal plating layer (C) is mentioned.

  As a method of forming the polymer layer (A) on the DLC layer, a method of applying or printing a polymer and a method of drying can be carried out by the methods exemplified above. Then, the polymer layer can be formed by heating and curing the polymer with ultraviolet rays.

  Next, the method for forming the plating base layer (B) on the polymer layer (A) is to form a pattern by printing a conductive ink containing metal nanoparticles, A plating base layer (B) can be formed by baking by the exemplified method.

  Next, the method for forming the metal plating layer (C) on the pattern of the plating base layer (B) by electrolytic plating or electroless plating can be carried out by the wet plating method exemplified above. It is preferable to use a copper plating method because it is excellent in productivity, mechanical properties of the obtained metal film, and cost.

  The metal base printed wiring board of the present invention thus manufactured can be used as a metal base printed wiring board in the applications exemplified above.

  Hereinafter, the present invention will be described in detail by way of examples.

[Preparation of conductive ink (1)]
By dispersing silver particles having an average particle diameter of 20 nm in a mixed solvent of 30 parts by mass of ethylene glycol and 70 parts by mass of ion-exchanged water using a compound in which polyoxyethylene is added to polyethyleneimine as a dispersant, metal nano particles are dispersed. A metal nanoparticle dispersion containing particles and a polymer dispersant having a basic nitrogen atom-containing group as a reactive functional group was prepared. Next, ion-exchanged water and a surfactant were added to the obtained metal nanoparticle dispersion, and the viscosity was adjusted to 10 mPa · s to prepare a conductive ink (1) for inkjet printing.

[Manufacture of resin for polymer layer (A-1)]
Polycarbonate polyol (polycarbonate diol having an acid group equivalent of 1000 g / equivalent obtained by reacting 1,4-cyclohexanedimethanol and carbonate) in a reaction vessel equipped with a stirrer, a reflux condenser, a nitrogen inlet tube, and a thermometer. 100 parts by weight, 9.7 parts by weight of 2,2-dimethylolpropionic acid, 5.5 parts by weight of 1,4-cyclohexanedimethanol, 51.4 parts by weight of dicyclohexylmethane diisocyanate in a mixed solvent of 111 parts by weight of methyl ethyl ketone By making it react, the organic solvent solution of the urethane prepolymer which has an isocyanate group in the molecular terminal was obtained.

  Next, 7.3 parts by mass of triethylamine is added to the organic solvent solution of the urethane resin to neutralize part or all of the carboxyl groups of the urethane resin, and 355 parts by mass of water is further added and sufficiently stirred. Thus, an aqueous dispersion of urethane resin was obtained.

  Next, 4.3 parts by mass of a 25% by mass ethylenediamine aqueous solution is added to the aqueous dispersion, and the particulate polyurethane resin is chain-extended by stirring, followed by aging / desolving, so that the solid content concentration is 30. An aqueous dispersion of mass% urethane resin was obtained.

  140 parts by mass of deionized water in a reaction vessel equipped with a stirrer, reflux condenser, nitrogen inlet tube, thermometer, dropping funnel for dropping the monomer mixture, dropping funnel for dropping the polymerization catalyst, water dispersion of the urethane resin obtained above 100 parts by mass of the liquid was added, and the temperature was raised to 80 ° C. while blowing nitrogen. In a reaction vessel heated to 80 ° C., a monomer mixture containing 60 parts by mass of methyl methacrylate, 30 parts by mass of n-butyl acrylate, and 10 parts by mass of Nn-butoxymethylacrylamide with stirring, 20 parts by mass of an aqueous ammonium sulfate solution (concentration: 0.5% by mass) was dropped from a separate dropping funnel over 120 minutes while maintaining the temperature in the reaction vessel at 80 ± 2 ° C. for polymerization.

  After completion of the dropwise addition, the mixture was stirred for 60 minutes at the same temperature, then the temperature in the reaction vessel was cooled to 40 ° C., and deionized water was added so that the nonvolatile content was 20% by mass, and then 200 mesh. By filtering with a filter cloth, a polymer layer (A-1) resin containing a carboxyl group and an Nn-butoxymethylacrylamide group as a reactive functional group was obtained.

[Preparation of ink containing resin for polymer layer (A-1)]
10 parts by mass of deionized water, 40 parts by mass of ethanol, and 30 parts by mass of ethylene glycol are added to 20 parts by mass of the resin for the polymer layer (A-1) obtained by the production of the resin for the polymer layer (A-1). By stirring and mixing, an ink containing a resin for the polymer layer (A-1) was obtained.

(Example 1)
An aluminum substrate (vertical 20 mm, horizontal 30 mm, thickness 1 mm) provided with a DLC layer having a thickness of 2 μm was used. When the surface roughness of the DLC layer was measured with an atomic force microscope, the surface roughness Rz was 75 nm. On the DLC layer of the base material, the ink containing the polymer layer (A-1) resin prepared as described above was applied to the entire surface of the DLC layer so that the film thickness after drying was 0.1 μm. The polymer layer (A-1) was formed by drying.

  Next, on the polymer layer (A-1) formed by the above-described method, the conductive ink (1) obtained above is applied to an inkjet printer (an inkjet tester EB100 manufactured by Konica Minolta IJ Co., Ltd., an evaluation printer head). KM512L, discharge amount 14pL) is used to print an LED lamp mounting wiring pattern having a line width of 90 μm and a film thickness of 0.2 μm, followed by baking at 120 ° C. for 20 minutes, thereby plating with conductive ink (1) An underlayer pattern was formed.

Next, the plating base layer made of the conductive ink (1) obtained above is set as a cathode, phosphorous copper is set as an anode, and the current density is 2 A / dm using an electrolytic plating solution containing copper sulfate. By performing electrolytic copper plating at ² for 10 minutes, a copper plating layer having a thickness of 20 μm was laminated on the surface of the layer made of conductive ink. As the electrolytic copper plating solution, 70 g / liter of copper sulfate, 200 g / liter of sulfuric acid, 50 mg / liter of chloride ions, and 5 ml / liter of additives (“Top Lucina SF-M” manufactured by Okuno Pharmaceutical Co., Ltd.) were used.

  Next, an InGaN-based white LED lamp (0.5 W type) is soldered to the LED lamp mounting copper wiring pattern formed on the DLC layer obtained above to produce an LED mounting circuit board for heat dissipation evaluation. did.

Next, as an evaluation of heat dissipation, an infrared thermography was applied to the LED mounting circuit board for heat dissipation evaluation under the conditions of only natural convection at an applied current I _{F of} 150 mA, an energization time of 1000 seconds, an ambient temperature of 25 ° C. As a result of measuring the surface temperature of the LED lamp at, it was 48 ° C.

(Example 2)
In Example 1, the ink containing the polymer layer (A-1) resin prepared above was applied on the entire surface of the DLC layer of the aluminum base material. In Example 2, the polymer layer ( A-1) Using an ink jet printer (ink jet tester EB100 manufactured by Konica Minolta IJ Co., Ltd., evaluation printer head KM512L, discharge amount 14 pL), the ink containing the resin for resin is an LED having a line width of 100 μm and a film thickness of 0.1 μm. The same pattern as the lamp mounting wiring pattern was printed and dried to form a pattern of the polymer layer (A-1).

  Next, on the pattern of the polymer layer (A-1) formed by the above method, the conductive ink (1) obtained above is used as an ink jet printer (inkjet tester EB100 manufactured by Konica Minolta IJ Co., Ltd., for evaluation). From the conductive ink (1), a wiring pattern for LED lamp mounting having a line width of 90 μm and a film thickness of 0.2 μm was printed using a printer head KM512L and a discharge amount of 14 pL, and then baked at 120 ° C. for 20 minutes. The pattern of the plating base layer to be formed was formed. Thereafter, electrolytic copper plating is performed in the same manner as in Example 1, and further, an LED lamp is mounted to produce an LED mounted circuit board for heat dissipation evaluation, and the heat dissipation of the LED lamp is performed under the same conditions as in Example 1. It was 41 degreeC as a result of measuring the surface temperature of an LED lamp with the infrared thermography.

[Production of comparative resin for adhesive]
The number average molecular weight obtained from adipic acid, terephthalic acid, and 3-methyl-1,5-pentanediol is 1006 in a reaction vessel equipped with a stirrer, thermometer, reflux condenser, dropping device, and nitrogen introduction tube. A diol (414 parts by mass), dimethylolbutanoic acid (8 parts by mass), isophorone diisocyanate (145 parts by mass) and toluene (40 parts by mass) were charged and reacted at 90 ° C. for 3 hours in a nitrogen atmosphere. Next, 300 parts by mass of toluene was further added to the reaction solution to obtain a urethane prepolymer solution having an isocyanate group at the terminal.

  Next, 816 parts by mass of the urethane prepolymer solution obtained above was added to a mixture obtained by mixing 27 parts by mass of isophoronediamine, 3 parts by mass of di-n-butylamine, 342 parts by mass of 2-propanol, and 576 parts by mass of toluene. And reacted at 70 ° C. for 3 hours to obtain a polyurethane polyurea resin solution. To this, 144 parts by mass of toluene and 72 parts by mass of 2-propanol were added to obtain a resin solution having a solid content of 30% by mass of the polyurethane polyurea resin.

  100 parts by mass of the resin solution obtained above and 70 parts by mass of a bisphenol A type epoxy resin (“JER828” manufactured by Mitsubishi Chemical Corporation) were stirred and mixed to obtain an adhesive layer resin.

(Comparative Example 1)
Instead of the aluminum substrate provided with the DLC layer used in Example 1, an aluminum substrate (vertical 20 mm, horizontal 30 mm, thickness 1 mm) without a DLC layer was used. The comparative adhesive resin obtained above was applied onto the aluminum base so that the film thickness after drying was 30 μm, and dried to form an adhesive resin layer as an insulating layer. A copper foil having a film thickness of 25 μm was bonded onto the resin layer and heat-pressed with a hot roll laminator.

  Next, an LED lamp mounting wiring pattern having a line width of 90 μm and a copper film thickness of 20 μm similar to that in Example 1 was prepared on the copper foil surface of the aluminum base with copper foil obtained above by a photomask etching method. The LED lamp is mounted in the same manner as in Example 1 to produce an LED mounted circuit board for heat dissipation evaluation. The heat dissipation of the LED lamp is performed under the same conditions as in Example 1, and the surface temperature of the LED lamp is measured by infrared thermography. It was 63 degreeC as a result of measuring.

  From the above results, it was confirmed that the metal-based printed wiring board of the present invention has excellent heat dissipation even when a semiconductor element that generates heat such as an LED lamp is mounted, and can suppress an increase in temperature of the semiconductor element.

DESCRIPTION OF SYMBOLS 1 ... Metal substrate 2 ... Diamond-like carbon layer 3 ... Polymer layer 4 ... Layer formed using conductive ink 5 ... Metal plating layer 10 ...・ Metal base printed wiring board

Claims (11)

  A polymer layer (A), a plating base layer (B) formed using a conductive ink on a diamond-like carbon layer of a base material provided with a diamond-like carbon layer on a metal base material, and a metal plating layer A metal-based printed wiring board obtained by sequentially laminating (C).   The metal base printed wiring board according to claim 1, wherein the conductive ink contains metal nanoparticles as a conductive substance (b2).   The metal-based printed wiring board according to claim 2, wherein the metal nanoparticles are dispersed by a polymer dispersant. The conductive ink is a conductive ink containing a compound (b1) having a reactive functional group [Y] and a conductive substance (b2),
And the polymer layer (A) is a layer comprising a polymer containing the compound (a1) having a reactive functional group [X],
The metal-based printed wiring board according to claim 3, wherein a bond is formed by reacting the reactive functional group [Y] with the reactive functional group [X].   The metal-based printed wiring board according to claim 4, wherein the reactive functional group [Y] is a basic nitrogen atom-containing group.   The metal-based printed wiring board according to claim 4, wherein the compound (b1) is a polyalkyleneimine or a polyalkyleneimine having a polyoxyalkylene structure having an oxyethylene unit.   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. It is a seed | species or more, The metal base printed wiring board of any one of Claims 4-6.   The metal base printed wiring board according to any one of claims 1 to 7, wherein the polymer layer (A) is formed in the same pattern as the plating base layer (B).   The metal base printed wiring board according to claim 1, wherein the metal base material is copper, aluminum, or aluminum nitride.   The said metal plating layer (C) is a copper plating layer, The metal base printed wiring board of any one of Claims 1-9. A polymer is applied or printed on a base material provided with a diamond-like carbon layer on a metal base material, and dried to form a polymer layer (A).
A conductive ink containing metal nanoparticles is printed on the polymer layer (A) and dried to form a pattern of the plating base layer (B).
A method for producing a metal-based printed wiring board, comprising forming a metal plating layer (C) on the pattern of the plating base layer (B) by electrolytic plating or electroless plating.

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