JP2007042725A - Metal pattern forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a metal pattern forming method that includes processes that are preferable for environments that does not discharge waste fluids or the like by eliminating expensive equipment for etching and vapor deposition, and is used for forming a high-density metal pattern, without insulation failures and is very satisfactory in adhesiveness and having less changes due to aging on a substrate, especially on a plastic substrate. <P>SOLUTION: The method is used for forming the metal pattern on a substrate surface by printing, after the substrate surface has been subjected to the processing (P) in which a substrate is arranged inside a processing chamber, and a polymeric film is formed on the substrate surface by causing plasma to generate, while introducing a monomer into the processing chamber. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for forming a metal pattern, and more particularly, to a method for forming a metal pattern having high adhesion and less defects such as poor insulation and a high density, and more particularly to a method for forming a metal pattern using a plastic substrate. It is.

  Conventionally, as a technique for forming a metal pattern on a substrate, a metal foil such as a copper foil is attached with an adhesive, and a photomask is used to etch unnecessary portions by etching, or a negative pattern on a copperless laminate. An additive method in which a plating resist is generated and a conductor pattern is formed by electroless plating is generally used. However, since the former requires an etching apparatus, the capital investment is large, and an expensive copper foil is used, and waste occurs during etching. In the latter case, since a large amount of processing waste liquid is generated, improvement in cost and environment has been demanded first.

  Further, a technique for performing metal vapor deposition after improving the wettability of the surface by irradiating the surface of the substrate with glow discharge plasma has been proposed in the technique described in JP-A-1-321687. However, in this method, it is necessary to perform etching in the same manner as described above, and expensive equipment is required, and metal deposition with low productivity is required. In addition, there is a problem that the degree of surface modification by plasma irradiation is insufficient and the adhesion of the metal thin film is poor.

  On the other hand, Japanese Patent Application Laid-Open No. 5-258269 discloses a technique in which an organic thin film using plasma polymerization is formed as a base layer in order to improve the adhesion between the metal-containing thin film and the substrate, and the metal-containing thin film layer is laminated thereon by solvent coating. 5-174357, 5-20662, 5-20663, 5-135344, and JP-A-7-153064, all of which are magnetic recording materials. The object is to increase the adhesion between the magnetic layer and the substrate, and it is insufficient as a means for improving the adhesion between the metal pattern constituting the electronic circuit and the substrate.

  In recent years, electronic circuits have been miniaturized and integrated, and photolithography apparatuses have been improved in accuracy as a pattern transfer technique for realizing the fine processing. However, the processing method has approached the wavelength of the light source for light exposure, and the lithography technology has also approached its limit. Therefore, in order to advance further miniaturization and higher accuracy, an electron beam drawing apparatus, which is a kind of charged particle beam apparatus, has been used in place of lithography technology. Techniques for performing fine pattern formation at a low cost are disclosed in the following Patent Documents 1 and 2, Non-Patent Documents 1, 2, and 3 and the like. This is a technique for transferring a predetermined pattern by embossing a stamper having a concavo-convex pattern identical to the pattern to be formed on the substrate against the resist film layer formed on the surface of the substrate to be transferred. According to the nano-contact printing technique described in Document 2 and Non-Patent Document 1, a silicon wafer is used as a stamper, and a fine structure of 25 nanometers or less can be formed by transfer. In addition, a mold made of PDMS (polydimethylsiloxane) polymer is used as a stamp, and a paste containing organic molecules or organometallic compounds / colloidal metal nanoparticles with catalytic activity is used as an ink. A method of forming a pattern by pressing a stamp is disclosed (for example, see Non-Patent Document 4).

  Stamps made of PDMS polymer have low surface energy, are chemically stable, and can be molded into various forms, so it is easy to form desired patterns on various substrate surfaces. Various metal pattern forming techniques using this are introduced.

  Further, in Patent Document 3 below, in a method for producing a metal pattern, the method includes a step of applying or printing a conductive paste on a substrate having a metal on a part of the surface and then curing to form a conductive coating film. A method for producing a metal pattern is disclosed, in which a metal surface is previously treated with a coupling agent and then a conductive paste is applied or printed. In this invention, the metal surface is treated with a coupling agent in advance, so that the metal surface and the conductive paste cured coating film exhibit high adhesion, and generally have both conductivity and adhesion which are in a trade-off relationship. It can be improved.

However, although the above method can produce a metal pattern with high density and few defects, this technique also does not sufficiently improve the adhesion between the ink and the substrate, and the circuit conductivity decreases with time. I had a problem that was easy to do.
US Pat. No. 5,259,926 US Pat. No. 5,772,905 JP-A-6-61602 S. Y. Chou et. al. , Appl. Phys. Lett. , Vol. 67, p. 3314 (1995) B. Michel et. al. , Chimia 56, 527 (2002) S. Y. Chou et. al. , Jpn. J. et al. Appl. Phys. Vol. 41 (2002) p. 4194-4197 Angew. Chem. Int. Ed. 1998, vol. 37, p. 550

  The present invention improves the above-mentioned conventional problems, that is, it is a process preferable for an environment in which expensive equipment such as etching and vapor deposition is unnecessary and waste liquid is not generated, and has excellent adhesion and no insulation failure. Another object of the present invention is to provide a metal pattern manufacturing method capable of forming a metal pattern with high density and little change with time on a substrate, particularly a plastic substrate.

  The above problem could be solved by the following configuration.

(Claim 1)
A method for forming a metal pattern by printing on a substrate surface, wherein the metal pattern is formed after the following treatment (P) is performed on the substrate surface.
[Process (P): A process in which a substrate is placed in a processing chamber, a monomer is introduced into the processing chamber, and plasma is generated to form a polymer film on the substrate surface]
(Claim 2)
The method of forming a metal pattern according to claim 1, wherein metal nano paste is used.

(Claim 3)
The method for forming a metal pattern according to claim 2, wherein the metal nanopaste contains gold nanoparticles.

(Claim 4)
4. The method for forming a metal pattern according to claim 2, wherein the metal nanopaste contains a dispersant and a solvent, and the dispersant or solvent and the polymer film can be chemically bonded to each other.

(Claim 5)
The method for forming a metal pattern according to any one of claims 1 to 4, wherein the substrate is a plastic substrate.

  It was possible to form a metal pattern on a plastic substrate having excellent adhesion, no insulation failure, high density and little change with time.

  Hereinafter, the present invention will be described in more detail.

<Pattern processing by printing>
The patterning process by printing in the present invention refers to a process for forming a metal pattern such as a circuit wiring, a transistor, or a memory on a metal, silicon wafer, or plastic substrate by printing. Nanocontact printing lithography method, screen printing And known techniques such as a printing method, a relief printing method, an intaglio printing method, and an ink jet printing method. Particularly preferred is a nanocontact printing lithography method. A circuit pattern printed by this method can be cured or fixed by heating or irradiation with an active energy ray such as UV light to obtain a metal pattern having effective conductivity. The volume resistance value of the metal pattern of the present invention is preferably in the range of 1 × 10 ⁻² Ω · cm to 1 × 10 ⁻⁹ Ω · cm.

<Process (P): Process for forming a polymer film on the substrate surface>
The treatment (P) for forming a polymer film on the substrate surface in the present invention is a method in which a substrate is placed in a processing chamber, a monomer is introduced into the processing chamber, and a polymer coating is formed on the substrate by plasma polymerization. Represents. The plasma generation method preferably used in the present invention may be any method as long as it can generate plasma and thereby coat the polymer on the substrate surface. DC glow discharge or low-frequency discharge by means of, high-frequency discharge by internal electrode system or external electrode system or coil-type system, microwave discharge by electron beam system or electron cyclotron resonance discharge. When the monomer used is in the gaseous state at the processing chamber temperature or normal temperature, it can flow into the processing chamber as it is, and in the liquid state, if the vapor pressure is relatively high, its vapor May be introduced as it is, or the liquid may be bubbled in with a diluent gas such as an inert gas. On the other hand, when it is not in a gaseous state and the vapor pressure is relatively low, it can be used in a gaseous state or in a high vapor pressure state by heating. The monomer may be used as it is, but from the viewpoint of discharge sustainability, stability, economy, etc., an inert gas such as helium, argon, neon, or nitrogen, hydrogen, oxygen, etc. It is also effective to dilute one of these gases alone or with two or more mixed gases.

  In the present invention, when plasma treatment is performed, the pressure in the processing chamber can be reduced, and the monomer alone or a mixture of monomer and diluent gas can be supplied into the low pressure processing chamber. The pressure in the treatment chamber is usually adjusted to 0.01 Pa to 13.3 kPa, more preferably 1.33 Pa to 1.33 kPa.

<monomer>
The monomer in the present invention is not particularly limited as long as it can form a polymer film on the substrate by the plasma polymerization method of the present invention, and is an organic or inorganic solid, liquid or gas, or a mixture thereof.

  Suitable organic monomers include carboxylic esters, methacrylic esters, acrylic esters, styrene, methacrylonitrile, alkenes and dienes such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, and others Alkyl methacrylates and corresponding acrylic esters, including organofunctional methacrylic esters and acrylic esters (glycidyl methacrylate, allyl methacrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, dialkylaminoalkyl methacrylate, and Methacrylic acid, acrylic acid, fumaric acid and esters, itaconic acid (and esters), maleic anhydride, styrene, α Methyl styrene, halogenated alkenes such as vinyl halides such as vinyl chloride and vinyl fluoride, and fluorinated alkenes such as perfluoroalkene, acrylonitrile, methacrylonitrile, ethylene, propylene, allylamine, vinylidene halide, butadiene, N-isopropyl Acrylamide such as acrylamide, methacrylamide, epoxy compounds such as glycidoxypropylene, glycidol, styrene oxide, butadiene monoxide, ethylene glycol diglycidyl ether, bisphenol A diglycidyl ether (and oligomers thereof), vinylcyclohexene oxide, oxetane compounds , Thiirane compounds such as bisphenol F dithioglycidyl ether, thietane compounds, aziridines Compounds Nitrogen-containing heterocyclic compounds such as pyrrole, thiophene, pyridine, quinoline, and thiazole, phosphorus-containing compounds such as dimethylallylphosphonate, silicon-containing compounds such as silanes (silanes, alkylhalosilanes, arylhalosilanes) and straight-chain ( For example, polydimethylsiloxane) and cyclic siloxanes (eg, octamethylcyclotetrasiloxane, Si-H containing, halo-functional, and haloalkyl-functional linear and cyclic siloxanes, such as tetramethylcyclotetrasiloxane and tri (monofluorobutyl) ) Trimethylcyclotrisiloxane), silane alkoxides (eg 3-aminopropyltriethoxysilane, 3-acryloxypropyltriethoxysilane, allyltriethoxysilane, chloromethylpheny Ethyl triethoxysilane, methacryloxypropyl triethoxysilane) and the like.

  Suitable inorganic monomers include metals and metal oxides including colloidal metals. Organometallic compounds are also suitable monomers and include titanates, tin alkoxides, zirconates, and metal alkoxides such as germanium and erbium alkoxides.

<Paste containing metal nanoparticles>
The surface of metal nanoparticles having an average particle diameter of 1 to 1000 nm is coated with a dispersant capable of binding to the metal contained in the metal fine particles and stably dispersed in a solvent.

  The metal is preferably at least one of gold, silver, copper, platinum, palladium, rhodium, osmium, ruthenium, iridium, iron, tin, zinc, cobalt, nickel, chromium, titanium, tantalum, tungsten, indium and silicon. Or an alloy composed of two or more metals. More preferably, it is classified as a noble metal, and more preferably silver, copper, platinum or gold. Most preferred is gold. The shape of the metal nanoparticles may be any of dendritic, flaky, spherical and irregular shapes, but is preferably dendritic electrolytic powder produced by electrolysis or spherical powder. The average particle size is preferably 1 to 30 nm, and 1 to 10 nm dendritic powder is more preferable from the viewpoint of high density and multi-contact point filling. However, the average particle diameter here refers to the median diameter based on volume obtained by “LA-500 laser diffraction type particle size distribution measuring device” manufactured by Horiba.

  Specifically, a compound having a reducing action on the cation of the metal is preferable as the dispersant, and a compound having a functional group containing a nitrogen atom, an oxygen atom or a sulfur atom for binding to the metal is more preferable. More preferably, it has a functional group containing a sulfur atom.

  Specific examples of the functional group include a hydroxyl group, an amino group, a mercapto group, and a carboxyl group. Moreover, what has the reactive group which can be chemically combined with the following polymer membrane | film | coat other than the functional group for couple | bonding with a metal is preferable. Due to the presence of these reactive groups, a surprising effect is achieved that the adhesion between the polymer film and the metal nanopaste is dramatically improved. Examples of the reactive group include an aromatic group, an alkoxysilyl group, a halosilyl group, a phosphate ester group, an epoxy group, a thiirane group, a nitrogen-containing heterocyclic group, a halogenated alkyl group, a halogenated aryl group, an aziridine group, and a methacrylic acid group. And vinyl groups such as acrylic acid groups, amino groups, hydroxyl groups, nitro groups, cyano groups, mercapto groups, carboxyl groups, isocyanate groups, isothiocyanate groups, ester groups, amide groups, imide groups and the like. Specific examples of the dispersant include amine compounds such as 2-methylaminoethanol, diethanolamine, diethylmethylamine, 2-dimethylaminoethanol, and methyldiethanolamine, alkylamines, ethylenediamine, alkyl alcohols, ethylene glycol, propylene glycol, and cystamine. (Dihydrochloride), 6-mercapto-1-hexanol, 2-mercaptoethanol, 4,4′-thiobiphenyl, 1-mercapto-2-propanol, 3-mercapto-1-propanol, 3-mercapto-2-butanol, 3-mercapto-1,2-propanediol, 2,3-dimercapto-1-propanol, dithiothreitol, dithioerythritol, 1,4-dithio-L-threitol, 3- (methylthio)- -Propanol, 4- (methylthio) -1-butanol, 3- (methylthio) -1-hexanol, 2,2'-thiodiethanol, 2-hydroxyethyl disulfide, 3,6-dithia-1,8-octanediol, 3,3'-thiodipropanol, 3-methylthio-1,2-propanediol, 3-ethylthio-1,2-propanediol, D-glucose diethyl mercaptal, 1,4-dithian-2,5-diol 1,5-dithiacyclooctane-3-ol, or 4-hydroxythiophenol, 3-mercaptopropyltriethoxysilane, 3-aminopropyltriethoxysilane, 3-mercaptopropylcyanide, 3-mercaptopropyl isocyanate 3-mercaptopropionic acid, 3-mercaptopropionic acid Le, 3-isocyanatopropyltrimethoxysilane, hexamethylene diisocyanate, N- chloroethyl hula Louis bromide, and 3-mercaptopropionic acid amide.

  The solvent is preferably a solvent having a relatively high boiling point that does not easily evaporate near room temperature. The organic solvent is benzene, toluene, hexanone, methyl isobutyl ketone, methyl amyl ketone or butyl carbitol, butyl carbitol acetate, butyl cellosolve. , Butyl cellosolve acetate, propylene glycol monomethyl ether acetate, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, ethylene or propylene glycol ethers such as triethylene glycol dimethyl ether, monobutyl ether, tetraethylene glycol dimethyl, dimethyl adipate, dimethyl glutarate, succinate Examples include known solvents such as diester salts of dibasic acids such as dimethyl acid. Water is also a preferred solvent. The following reactive monomers and prepolymers are more preferably used.

  By using a reactive monomer or prepolymer, the scattering of the organic solvent at the time of heating is reduced, so that an exhaust facility is not required, and the effect of greatly improving the adhesion between the polymer film and the metal nanopaste is exhibited.

<Reactive monomer and prepolymer>
As the reactive monomer or prepolymer, a monomer or prepolymer that is polymerized by heating or UV light is preferably used. Thermally polymerizable monomers and prepolymers include phenolic resins, amino resins, xylene resins, urea resins, alkyd resins, silicon resins, furan resins, unsaturated polyester resins, epoxy resins, polyurethane resins, polyester / polyol resins, Known thermosetting resins such as an acrylic resin, a methylolated hydroxystyrene polymer and / or a derivative thereof can be used. Two or more of the above thermopolymerizable monomers and prepolymers used in the present invention may be mixed and used. Examples of UV curable monomers and prepolymers include resins (PAK-1) based on tripropylene glycol acrylate with dimethoxyphenylacetophenone as an initiator, epoxy compounds, vinyl ethers, cyclic ethers and ketones, lactones, Oxetanes, styrenes, acrolein, vinylarenes such as 4-vinylbiphenyl, alicyclic vinyl compounds such as vinylcyclohexene, spiroorthoesters, spiroorthocarbonates, bicycloorthoesters, isobutylene, butadiene and isoprene Examples include dienes such as cation polymerizable monomers or prepolymers such as phenol / formaldehyde resins, among which epoxy monomers or prepolymers are preferably used. Examples of the epoxy monomer or prepolymer used in the present invention include conventionally known aromatic epoxy resins, alicyclic epoxy resins, and aliphatic epoxy resins. Particularly preferred as the aromatic epoxy resin is a polyglycidyl ether of a polyhydric phenol having at least one aromatic nucleus or an alkylene oxide adduct thereof. Examples thereof include glycidyl ether and epoxy novolac resin produced by the reaction of bisphenol A or its alkylene oxide adduct and epichlorohydrin. As the polymerization initiator for these cationic polymerizable monomers or prepolymers, known onium salt initiators such as sulfonium salts and iodonium salts are preferably used.

  Particularly preferred as the alicyclic epoxy resin is to epoxidize a polyglycidyl ether of polyhydric alcohol having at least one alicyclic ring or a compound containing cyclohexene or cyclopentene ring with an appropriate oxidizing agent such as hydrogen peroxide or peracid. Is a cyclohexene oxide or cyclopentene oxide-containing compound obtained by A typical example of polyglycidyl ether is glycidyl ether produced by the reaction of hydrogenated bisphenol A or its alkylene oxide adduct and epichlorohydrin.

  Particularly preferred as the aliphatic epoxy resin is a polyglycidyl ether of an aliphatic polyhydric alcohol or an alkylene oxide adduct thereof. Typical examples are 1,6-hexanediol diglycidyl ether, glycerin triglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, aliphatic polyhydric alcohols such as ethylene glycol, propylene glycol, and glycerin. Polyglycidyl ethers of polyether polyols obtained by adding one or more alkylene oxides (ethylene oxide, propylene oxide) to the above. Furthermore, monoglycidyl ethers of higher aliphatic alcohols, phenols, cresols, or monoglycidyl ethers of polyether alcohols obtained by adding alkylene oxides to these can also be blended as diluents.

  Although the aromatic epoxy resin, alicyclic epoxy resin or aliphatic epoxy resin can be used alone for the monomer or prepolymer of the present invention, it is desirable to mix them appropriately according to the desired performance.

<Additives, blending amount>
The amount of the solvent in the metal nanopaste of the present invention is 5 to 50% by mass, preferably 5 to 40% by mass with respect to the total mass. The compounding quantity of the metal in the metal nanopaste used for this invention is used in 50-95 mass% with respect to the total mass, Preferably it is 70-90 mass%, More preferably, it is 80-90 mass%. . The blending amount of the dispersant in the present invention is 0.01% to 400% by mass, preferably 0.01% to 40% by mass, based on the total mass of the metal. In the metal nanopaste used in the present invention, benzoic acid and / or derivatives thereof, ester carboxylic acids, ether carboxylic acids, one or more known reducing agents or chelating agents can be used as additives. .

  In the metal nanopaste used for this invention, the compounding quantity of the above additive is 0.1-20 mass% normally with respect to the total mass, Preferably it is 0.5-10 mass%. Furthermore, as an additive, known thixotropic agents and leveling agents can be used as needed for the purpose of improving the dispersibility of the metal and the printability of the paste. In order to produce the metal nanopaste used in the present invention, it is adjusted by sufficiently uniformly kneading with a disper, ball mill, mechanical stirrer, triple roll or the like. The amount of the solvent varies depending on the type of kneader, the kneading conditions, and the type of solvent. It is preferable to adjust the amount of the solvent so that the paste viscosity after kneading can be printed.

<Gold nanoparticles>
The shape of the gold nanoparticle is not particularly limited, but is preferably a dendritic electrolytic powder produced by electrolysis or a spherical powder. Although an average particle diameter is not specifically limited, It is preferable that it is 1-30 nm, and the dendritic powder of 1-10 nm is more preferable from the point of a high density and multi-contact point filling. However, the average particle diameter here refers to the median diameter based on volume obtained by “LA-500 laser diffraction type particle size distribution measuring device” manufactured by Horiba.

  Although the preparation method of gold nanoparticles is not particularly limited, for example, a method of reducing a metal salt in a solution in the presence of a protective polymer is common. See, for example, Surface, 17, 279 (1979); Mater. Chem. 12, 2862-2865 (2002); and JP-A-5-224006. The reaction solvent and the reaction temperature are not particularly limited, but the reaction may be carried out in an aqueous solution system, a mixed solvent system of water and an organic solvent, or a system in an organic solvent, preferably a mixed solvent of water and an organic solvent. It is a reaction in a system or an organic solvent, more preferably a reaction in a mixed solvent system of water and an organic solvent.

<Reactive group of polymer film>
Examples of the reactive group include various known groups such as a hydroxyl group, a thiol group, a carboxyl group, a sulfonic acid group, a phosphoric acid group, an acyl group, an amino group, an amide group, an aldehyde group, a halogen atom, an ester group, and a keto group. Groups, epoxy groups, cyano groups, cyanate groups, isocyanate groups, heterocyclic groups, aromatic groups and the like are included.

<Plastic substrate>
The plastic substrate can be composed of a film excellent in smoothness made of polyethylene terephthalate (PET), polycarbonate (PC), polyatelate (PAR), polyethersulfone (PES), cycloolefin polymer resin (Zeonoa) or the like. Various molding materials can be used for the plastic that is the main raw material of the substrate. However, depending on the purpose of the metal pattern to be produced, it is appropriate to consider moldability, heat resistance, chemical resistance, adsorptivity, etc. Selected. For example, polystyrene, polyethylene, polyvinyl chloride, polypropylene, polycarbonate, polyester, polymethyl methacrylate, polyvinyl acetate, vinyl-acetate copolymer, styrene-methyl methacrylate copolymer, acrylonitrile-styrene copolymer, acrylonitrile -Butadiene-styrene copolymer, nylon, polymethylpentene, silicone resin, amino resin, polysulfone, fluorine resin, saturated cyclic polyolefin resin, etc. are conceivable.

  EXAMPLES Hereinafter, although this invention is demonstrated further in detail based on an Example and a comparative example, this invention is not limited only to these Examples.

<substrate>
A 100 mm square with a thickness of 0.2 mm was used.

  The substrate material types used are shown below.

1. Polyethylene terephthalate (Teijin Tetron: Teijin DuPont Films)
2. Polycarbonate (Panlite: manufactured by Teijin Chemicals Limited)
3. Polyethersulfone (Sumika Excel PES: manufactured by Sumitomo Chemical Co., Ltd.)
4). Silicon (Silicon substrate with silica: manufactured by Shin-Etsu Chemical Co., Ltd.)
5. Polyethylene naphthalate (Teonex: Teijin DuPont Films)
6). Polyvinyl chloride (Asahi PVC: Asahi Glass Company)
7). Polypropylene (Idemitsu Polypropylene: Idemitsu Chemical Co., Ltd.)
8). Cycloolefin (APEL: made by Mitsui Chemicals)
9. Triacetate (L-50: manufactured by Daicel Chemical Industries)
10. Polyimide (Upilex-S: manufactured by Ube Industries)
11. Polyamide (Leona 90G: Asahi Kasei Chemicals)
12 Polyacetal (Tenac CHC: Asahi Kasei Chemicals)
13. Polyphenylsulfone (Radel R :)
[Process for forming polymer film on substrate surface (P)]
Using the external electrode type high-frequency plasma discharge apparatus shown in FIG. 1, it was processed under the following conditions to form a polymer film (film thickness: 0.3 μm) on the substrate surface.

  Table 1 shows examples of substrates subjected to a treatment for forming a polymer film.

Monomer gas type: (1)
The following dilution gas type: (2)
Pressure: 13.3Pa
Discharge power: 100W
Discharge frequency: 13.56 MHz
Processing time: 60 sec.
(1) The monomer gas type used is shown.

1. Hexafluoropropylene Styrene 3. 3. Methyl methacrylate 6. Glycidyl methacrylate 5.3-Mercaptopropyltriethoxysilane 6. 3-Aminopropyltriethoxysilane OXT-221 (manufactured by Toa Gosei Chemical)
8). Celoxide 2021 (Epoxy monomer manufactured by Daicel Chemical Industries)
9. 4-Vinylpyridine Trimethylchlorosilane 11. Chlorovinylidene (2) Indicates the type of dilution gas used.

1. N ₂
2. Ar
3. Ne
In FIG. 1, 14 is a processing chamber, 15 is a monomer gas supply pipe, and a monomer gas or monomer gas diluted with a dilution gas is supplied from the supply pipe 15 into the processing chamber, and a plasma power source 17 is provided between the electrodes 16a and 16b. When the plasma region is further formed, radicals are generated, and the polymerizable film is bonded to the surface of the workpiece 18 between the electrodes 16a and 16b. Reference numeral 19 denotes a gas discharge pipe, 20 denotes a pump, and 21a and 21b denote valves.

  Table 1 below shows examples of substrates subjected to the polymer film formation treatment.

  In addition, the board | substrate examples 21-24 do not perform a polymer film formation process but use the board | substrate material seed | species as it is.

  Next, a metal pattern was formed on the substrate using a paste containing the following metal nanoparticles.

[Paste containing metal nanoparticles]
(Metal nanoparticles)
1. Nickel nanoparticles: those described in Example 1 of JP-A-2003-213111 (average particle size: 3.0 nm)
2. Palladium nanoparticles: those described in Example 2 of JP-A No. 2003-21311 (average particle diameter: 1.2 nm)
3. Copper nanoparticles: those described in Example 3 of Japanese Patent Application Laid-Open No. 2003-213111 (average particle diameter of 2.8 nm)
4). Silver nano-particles: Solvent toluene removed from vacuum ultra-fine metal particle dispersion by vacuum metallurgy (average particle size 7.0 nm)
5. Gold nano-particles: Solvent toluene removed from ultra-fine gold particle dispersion manufactured by Vacuum Metallurgical Co., Ltd. (average particle size 7.0 nm)
(Dispersant)
1. 1,8-octanedithiol 2. Diethanolamine 4. Propylene glycol 4.6-mercapto-1-hexanol D-glucose diethyl mercaptal 6.3-mercaptopropyltriethoxysilane 7.3-aminopropyltriethoxysilane 8.3-mercaptopropyl isocyanate 9.3-mercaptopropionic acid 10. N-chloroethylphthalimide (solvent)
1. Toluene 2. 2. methyl methacrylate 3. Methyl isobutyl ketone Tripropylene glycol acrylate 5. Butyl cellosolve 6. 6. Dimethyl adipate Celoxide 2021 (Epoxy monomer manufactured by Daicel Chemical Industries)
8). Celoxide 3000 (Epoxy monomer manufactured by Daicel Chemical Industries)
9. Methacrylic acid glycidyl ester 10. 11. Bisphenol A-diglycidyl ether 11.3-epoxypropyltriethoxysilane Comporacene E103 (Arakawa Chemical Industries)
13. OXT-101 (manufactured by Toa Gosei Co., Ltd.)
14 OXT-610 (manufactured by Toa Gosei Chemical)
15. OXT-221 (manufactured by Toa Gosei Chemical)
16. CYMM-100 (manufactured by Daicel Chemical Industries)
17.

18. Water (additive)
1. Syracure UVI-6990 (manufactured by Union Carbide)
2. Syracure UVI-6974 (Union Carbide)
3. Adekaoptomer SP-152 (Asahi Denka Kogyo Co., Ltd.)
4). RP-2074 (Rhodia)
5. Irgacure 261 (Ciba Geigy)
6). Irgacure 184 (Ciba Geigy)
7). Irgacure 369 (Ciba Geigy)
8).

9. Benzoic acid 10. Benzoylacetone (Method for preparing metal nanopaste)
As shown in Table 2, metal nano pastes were prepared by blending metal nanoparticles, a dispersant, a solvent, and additives, and stirring and kneading (45 ° C., 3 hours) with a mechanical stirrer. The viscosity of the metal nano paste (spiral viscometer, measurement temperature 23 ° C.) is shown.

  In addition, a part represents a mass part.

(Metal pattern forming method by printing)
1. Screen Printing Using a paste containing metal nanoparticles shown in Table 2, using a stainless steel # 500 mesh screen plate, a 10 × 50 mm wide pattern is displayed by screen printing method with an average film thickness of 30 μm at the time of application. Printed on the substrate shown in FIG. After printing, the nanoparticle paste coating layer on the substrate was subjected to treatments A to C shown in Table 3 to form a metal pattern. The average film thickness was 5 μm.

2. Inkjet printing Using a paste containing metal nanoparticles shown in Table 2, a 10 x 50 mm wide pattern was printed on the substrate shown in Table 1 by the inkjet printing method with an average film thickness of 10 µm at the time of coating by inkjet coating. . After printing, processes A to C shown in Table 3 were performed to form a metal pattern. The average film thickness was 1 μm.

3. Contact Printing Method Using a paste containing metal nanoparticles shown in Table 2, a metal pattern was formed on a substrate by a micro-contact printing method. The PDMS stamp used at this time was prepared as follows by a known method (reference: Langmuir, 1994, vol. 10, p. 1498). First, parts A and B of Sylgard® 184 silicon elastomer (Dow Corning, USA) were mixed in a plastic beaker at a 10: 1 mass ratio. After that, it was poured into a master formed by forming a pattern having a desired shape in a lithography process, left at room temperature for about 2 hours, and then completely aged in an oven at 60 ° C. for 2 hours. The completed stamp had a pattern line width of 50 μm, a depth of 50 μm, and a pattern interval of 100 μm.

  Next, the paste containing metal nanoparticles shown in Table 2 was dropped onto the substrate shown in Table 1 from which foreign substances were completely removed. After that, place the PDMS polymer stamp produced as described above on the ink, apply an appropriate force evenly on the stamp, adhere the stamp and the substrate, and push the excess ink out of the stamp. It was. At this time, the excessive amount of ink was removed through a casting method. After the ink was completely dried, the stamp was removed to obtain a predetermined pattern. Then, processing AC shown in Table 3 was given, and the metal pattern was formed. Here, the line width of the pattern was 50 μm, the height was 1 μm, and the distance between the patterns was 100 μm.

(Performance evaluation of the obtained metal pattern)
Measurement of conductivity This is a value obtained by measuring the volume resistivity of the formed metal pattern by a two-terminal method using a digital multimeter (R6551 manufactured by Advantest). In addition, the calculation formula of volume specific resistance is shown in the following formula.

Volume resistivity (Ω · cm) = (R × t × W) / L
R: Resistance value between electrodes (Ω)
t: thickness of coating film (cm)
W: Width of coating film (cm)
L: Distance between electrodes (cm)
Moisture Resistance Test The moisture resistance of the formed metal pattern was determined by performing a standing test for 300 hours in an environment of 60 ° C. and 95% relative humidity, and determining the rate of change WR of resistance value before and after that by the following equation.

Resistance change rate WR1 (%) = (R300-R0) / R0
R0: resistance value of the coating before testing (Ω)
R300: Resistance value after 300 hours test (Ω)
The moisture resistance of the coating film is displayed as follows according to the value of WR1.

A: WR1 is less than 30% B: WR1 is 30% to less than 100% C: WR1 is 100% or more Heat resistance test The heat resistance of the formed metal pattern is 10000 in an environment of 90 ° C. and 35% relative humidity. A time leaving test was performed, and the change rate WR of the resistance value before and after that was obtained by the following equation.

Resistance change rate WR2 (%) = (R10000−R0) / R0
R0: resistance value of the coating before testing (Ω)
R10000: Resistance value after 10,000 hours test (Ω)
The moisture resistance of the coating film is displayed as follows according to the value of WR2.

A: WR2 is less than 30% B: WR2 is 30% or more and less than 100% C: WR2 is 100% or more Adhesion test The adhesion was evaluated with the substrate formed by the above method. The number of cross-cuts of the coating film remaining on the substrate was determined in accordance with the cross-cut cello tape (registered trademark) peel test method of JIS K 5400 (1979). Judgment criteria are as follows.

A: 100/100
B: 90/100 or more and less than 100/100 C: 50/100 or more and less than 90/100 D: 0/100 or more and less than 50/100 The results are shown in Table 3.

* Processing after printing method A: 120 ° C. 3 hours of heat treatment B: irradiating a low-pressure mercury lamp at an energy density of 100 mJ / cm ² treatment C: after irradiation with a low-pressure mercury lamp at an energy density of 100mJ / cm ^2, 30 at 60 ° C. Second Heat Treatment As shown in Table 3, the metal patterns (Examples 1 to 20) obtained according to the present invention were formed on the substrate surface while maintaining high conductivity (10 ⁻² to 10 ⁻⁷ Ω · cm). Excellent adhesion to It was also found to be excellent in environmental stability such as moisture resistance and heat resistance. On the other hand, those not subjected to treatment for forming a polymer film (Examples 21 to 24) had low conductivity, poor adhesion to the substrate surface, and insufficient moisture resistance and heat resistance. Those treated with the silane coupling agent (Examples 25 to 27) had relatively good conductivity and moisture resistance, but were inferior to the present invention in terms of heat resistance and adhesion.

1 shows an external electrode type high-frequency plasma discharge apparatus used in the present invention.

Explanation of symbols

14 Processing chamber 15 Gas supply pipe 16a, 16b Electrode 17 Power supply 18 Processed object 19 Gas exhaust pipe 20 Pump 21a, 21b Valve

Claims (5)

A method for forming a metal pattern by printing on a substrate surface, wherein the metal pattern is formed after the following treatment (P) is performed on the substrate surface.
[Process (P): A process in which a substrate is placed in a processing chamber, a monomer is introduced into the processing chamber, and plasma is generated to form a polymer film on the substrate surface] The method of forming a metal pattern according to claim 1, wherein metal nano paste is used. The method for forming a metal pattern according to claim 2, wherein the metal nanopaste contains gold nanoparticles. 4. The method for forming a metal pattern according to claim 2, wherein the metal nanopaste contains a dispersant and a solvent, and the dispersant or solvent and the polymer film can be chemically bonded to each other. The method for forming a metal pattern according to any one of claims 1 to 4, wherein the substrate is a plastic substrate.

Images