WO2008041780A1 - Copper microparticle, method for production of copper microparticle, insulating material, wiring structure, method for production of wiring circuit board, and electronic/electric device - Google Patents

Copper microparticle, method for production of copper microparticle, insulating material, wiring structure, method for production of wiring circuit board, and electronic/electric device Download PDF

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Publication number
WO2008041780A1
WO2008041780A1 PCT/JP2007/069785 JP2007069785W WO2008041780A1 WO 2008041780 A1 WO2008041780 A1 WO 2008041780A1 JP 2007069785 W JP2007069785 W JP 2007069785W WO 2008041780 A1 WO2008041780 A1 WO 2008041780A1
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Prior art keywords
copper
copper fine
fine particles
unsaturated fatty
fatty acid
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PCT/JP2007/069785
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French (fr)
Japanese (ja)
Inventor
Takeshi Bessho
Hiroshi Yanagimoto
Masazumi Okido
Ryoichi Ichino
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Toyota Jidosha Kabushiki Kaisha
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Publication of WO2008041780A1 publication Critical patent/WO2008041780A1/en

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    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K1/00—Printed circuits
    • H05K1/02—Details
    • H05K1/09—Use of materials for the conductive, e.g. metallic pattern
    • H05K1/092—Dispersed materials, e.g. conductive pastes or inks
    • H05K1/097—Inks comprising nanoparticles and specially adapted for being sintered at low temperature
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F1/00—Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
    • B22F1/05—Metallic powder characterised by the size or surface area of the particles
    • B22F1/054—Nanosized particles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F1/00—Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
    • B22F1/10—Metallic powder containing lubricating or binding agents; Metallic powder containing organic material
    • B22F1/102—Metallic powder coated with organic material
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F9/00—Making metallic powder or suspensions thereof
    • B22F9/16—Making metallic powder or suspensions thereof using chemical processes
    • B22F9/18—Making metallic powder or suspensions thereof using chemical processes with reduction of metal compounds
    • B22F9/24—Making metallic powder or suspensions thereof using chemical processes with reduction of metal compounds starting from liquid metal compounds, e.g. solutions
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y30/00—Nanotechnology for materials or surface science, e.g. nanocomposites
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K2201/00—Indexing scheme relating to printed circuits covered by H05K1/00
    • H05K2201/02—Fillers; Particles; Fibers; Reinforcement materials
    • H05K2201/0203—Fillers and particles
    • H05K2201/0206—Materials
    • H05K2201/0224—Conductive particles having an insulating coating
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K3/00—Apparatus or processes for manufacturing printed circuits
    • H05K3/40—Forming printed elements for providing electric connections to or between printed circuits
    • H05K3/4038—Through-connections; Vertical interconnect access [VIA] connections
    • H05K3/4053—Through-connections; Vertical interconnect access [VIA] connections by thick-film techniques

Definitions

  • Copper fine particles, copper fine particle manufacturing method, insulating material, wiring structure, printed circuit board manufacturing method, and electronic / electric equipment technical field Copper fine particles, copper fine particle manufacturing method, insulating material, wiring structure, printed circuit board manufacturing method, and electronic / electric equipment technical field
  • the present invention relates to a method for producing high-dispersibility nano-order copper fine particles and copper fine particles that stably synthesize copper fine particles that are easily oxidized in a solvent, and to synthesize the copper fine particles synthesized by the method.
  • the present invention relates to a wiring structure having a child as a conductor.
  • Metal nanoparticles exhibit various unique properties due to their extremely small particle size, so conductive materials, coloring materials, capacitors, biosensors, 'chemical sensors, fluorescent materials, polarizing materials, magnetic memory materials, etc. It is used in various fields.
  • Metal nanoparticle synthesis methods are largely divided into break-down and build-up methods. Metals are mainly manufactured by the build-up method because they are highly malleable and ductile. In addition, the build-up method is classified into a dry method and a wet method, and many manufacturing methods have been developed.
  • metal nanoparticles by dry method a method of producing metal nanoparticles by gas evaporation method is known.
  • a method for producing metal nanoparticles by depositing metal on a polymer matrix film by vacuum deposition is known.
  • the metal nanoparticles obtained by these methods have a very high concentration and have the advantage of containing almost no impurities.
  • the particle size distribution is wide, the physical properties depend on the particle size of the metal nanoparticles ( It was unsuitable for applications using the size effect.
  • these methods are disadvantageous in production because they require special equipment for producing metal vapor.
  • the wet method of obtaining metal nanoparticles by reducing metal ions in solution does not require special equipment and has the advantage of being easy to scale up.
  • Japanese Patent Application Laid-Open No. 59-1717 3206 discloses a polyol method as a method for synthesizing metal fine particles in a highly productive dense system.
  • the polyol method is a method in which a copper oxide or salt such as copper oxide is heated and reduced in a polyol, and the polyol plays three roles: a solvent, a reducing agent, and a protective agent. As a result, it is possible to obtain submicron or micrometer metal particles even in a dense system.
  • the polyol method which is a liquid phase method suitable for mass production, is applied, and the particle size is as fine as 100 nm or less and its uniformity.
  • copper oxides, hydroxides or salts are heated and reduced in ethylene glycol, diethylene glycol or triethylene glycol solutions to obtain copper fine particles.
  • precious metal ions such as Pd and Ag for nucleation
  • polyvinylpyrrolidone as a dispersant and an amine organic compound as a reduction reaction control agent. It is disclosed that a copper fine particle dispersion is obtained by adding a copper-containing inorganic compound to obtain copper fine particles containing a trace amount of a noble metal, and substituting and concentrating the solution with a polar solvent.
  • electronic devices such as personal computers, mobile phones, digital still cameras, and liquid crystal televisions are used in various fields.
  • These electronic devices include, for example, a circuit board such as a TFT array substrate having a number of TFTs (thin film transistors) and wirings.
  • Such a circuit board is generally processed when an unnecessary portion of a thin film formed by vapor deposition such as CVD (chemical vapor deposition) or sputtering is removed (etched) by photolithography or the like. Is formed by repeating a plurality of times.
  • CVD chemical vapor deposition
  • sputtering etching
  • the wiring on the circuit board is formed by a so-called ink jet method (liquid droplet discharge method) in which a liquid material containing conductive fine particles is discharged to a desired region to form a desired pattern including an object to be discharged.
  • a forming technique has been proposed.
  • a liquid material containing fine metal particles containing any one of gold, silver, copper, palladium, and nickel a particle size of 0. 0
  • a wiring is formed by an ink jet method using a paste in which silver fine particles of about 1 ⁇ m are dispersed in an organic solvent. Disclosure of the invention
  • the present invention relates to a method for producing highly dispersed nano-order copper fine particles and a copper fine particle that is synthesized by stably holding copper fine particles that are easily oxidized in a solvent, and heat conduction of the copper fine particles synthesized by the method. It is an object to provide an insulating material having a body, a wiring structure having a copper fine particle synthesized by the method as a conductor, and the like.
  • the present inventors have found that the above problem can be solved by a wet method using a plurality of specific weak reducing agents, and have reached the present invention.
  • the present invention is an invention of copper fine particles (nanoparticles), and the average particle size is 1
  • the copper fine particles of the present invention are highly dispersible without being agglomerated by being modified with a carboxyl end group of an unsaturated fatty acid, regardless of nanoparticles having an average particle size of 100 nm or less.
  • the unsaturated fatty acid one or two or more C having 8 to 20 carbon atoms is used.
  • the properties of the copper fine particles of the present invention can be adjusted from hydrophilic to hydrophobic depending on the proportion of unsaturated fatty acids modified on the surface.
  • the surface of the copper fine particle is modified with a carboxyl end group of an unsaturated fatty acid, it shows hydrophobicity.
  • the present invention is an invention of the above-described method for producing copper fine particles, comprising a primary reduction step in which an unsaturated fatty acid solution containing copper ions and an aldose (reducing monosaccharide) solution are mixed to form an emulsion.
  • oleic acid is preferably exemplified as the unsaturated fatty acid
  • glucose is preferably exemplified as the aldose (reducing monosaccharide) from the viewpoint of weak reducibility.
  • Copper is more easily oxidized than noble metals, and it has been difficult to synthesize by holding nanoparticles in a solvent in a metal state.
  • copper nanoparticles were synthesized by a process using an oleic acid solution A containing copper ions, a weak reducing agent, an aqueous glucose solution B, and an ascorbic acid aqueous solution C.
  • a nano-shaped solid is produced by primary reduction to copper monoxide with glucose, and then secondarily reduced with ascorbic acid to form copper nanoparticles.
  • the chemicals used prevent copper from being reoxidized in addition to reducing copper ions.
  • a and B are mixed and stirred, an emulsion is formed, and primary reduction occurs on the surface of the emulsion.
  • the present invention relates to the application of the above copper fine particles, wherein the polymer matrix has an average particle size of 100 nm or less, and a part or all of the surface is a carboxyl terminal of unsaturated fatty acid.
  • the polymer matrix has an average particle size of 100 nm or less, and a part or all of the surface is a carboxyl terminal of unsaturated fatty acid.
  • It is an insulating material characterized in that copper fine particles modified with a group are dispersed.
  • oleic acid is preferable as the unsaturated fatty acid. This is as described above.
  • the contained copper fine particles have excellent thermal conductivity and become an insulating material by a polymer matrix. As a result, the insulating material is excellent in heat dissipation and thermal conductivity.
  • the present invention relates to another application of the above-mentioned copper fine particles, and the average particle size is 10 0 in a recess or a hole selected from a wiring groove, a via hole, a contact hole and a through hole in a circuit board.
  • the wiring structure is characterized in that a part or all of the surface is filled with fine copper particles modified with unsaturated fatty acid force lpoxyl end groups.
  • oleic acid is preferable as the unsaturated fatty acid.
  • the present invention is a method for manufacturing a printed circuit board having the above-described wiring structure, and includes copper ions in a recess or a hole selected from a wiring groove, a via hole, a contact hole, and a through hole in a circuit board.
  • oleic acid is preferable as the unsaturated fatty acid.
  • a method for filling copper fine particles into at least one recess or hole selected from wiring grooves, via holes, contact holes and through holes in a circuit board a screen printing method, a dispense method, an ink jet method, or a spin coating method can be used. Preferably exemplified.
  • the present invention is an electronic device having an insulating material containing the above copper fine particles.
  • the present invention is an electronic device having a wiring structure having an insulating material containing the above copper fine particles.
  • the copper fine particles of the present invention exhibit high dispersibility regardless of nano-order.
  • the method for producing copper fine particles of the present invention is excellent in productivity and operability from the laboratory scale to the factory scale, and can synthesize copper fine particles that are easily oxidized in a stable manner.
  • the insulating material having the copper fine particles of the present invention as a heat conductor is expensive.
  • the wiring structure which is a useful insulating material having thermal conductivity and has the copper fine particles of the present invention as a conductor realizes a fine pitch wiring circuit.
  • Figure 1 shows the experimental procedure used in this example.
  • FIG. 2 shows a conceptual diagram of the reaction mechanism of this example.
  • Figure 3 shows an XRD pattern (Figure 3a), particle size distribution (Figure 3b), SEM of a representative sample obtained by reducing copper sulfate in a solution extracted using the process of the present invention. A photograph is shown (Fig. 3c, d).
  • Figure 4 shows the change in the hydrophobic properties of copper particles when synthesized with varying weight ratios of copper and oleic acid.
  • the unsaturated fatty acid used for producing the copper fine particles of the present invention those having 1 or 2 or more C double bonds having 8 to 20 carbon atoms can be used.
  • mono-unsaturated fatty acids having one unsaturated bond myristoleic acid (9_monounsaturated fatty acid having 14 carbon atoms), palmitoleic acid (cis 9 mono-carbon having 16 carbon atoms) Unsaturated fatty acid), oleic acid (cis mono-unsaturated fatty acid with 1-7 carbon atoms), elaidic acid (1-7 carbon atoms.
  • Trans 9-monounsaturated fatty acid, trans isomer of oleic acid), Paxenoic acid (1 1-monounsaturated fatty acid with 1 to 7 carbon atoms), gadoleic acid (cis-9 mono-unsaturated fatty acid), diunsaturated fatty acid with two unsaturated bonds, linoleic acid (1 carbon number) 7 -cis-9-cis- 1 2-diunsaturated fatty acid), a tri-unsaturated fatty acid with three unsaturated bonds, ⁇ -linolenic acid (9, 1 2, 1 5-carbon with 1 7 carbons) Unsaturated fatty acids), eleostearic acid (9,11,13-triunsaturated fatty acids having 1 to 7 carbon atoms), etc. That. Of these, oleic acid is preferably exemplified.
  • the aldose (reducing monosaccharide) used in producing the copper fine particles of the present invention is a monosaccharide having one aldehyde group at the end of the chain, and there exist D-form and L-form.
  • aldtriose darrisel aldehyde, aldetrose, erythro Sucrose, throse, anoled pentose, ribose, lyxose, xylose, arabinose, anoledo hexose, sucrose, talose, growth, gnolecose, ano-reose, mannose, galactose, idose, funo lectose.
  • glucose is preferably exemplified.
  • a part of glucose and the like has a chain structure in an aqueous solution, and an aldehyde group is present at the end of this structure, so that an aqueous solution of glucose and the like shows reducibility.
  • Ascorbic acid used in producing the copper fine particles of the present invention is converted into dehydroascorbic acid by releasing two hydrogen atoms.
  • Cu 2 + ions in an aqueous solution were first extracted into oleic acid.
  • the extracted Cu 2+ ions were reduced to copper oxide (I) and copper metal by glucose and ascorpic acid, respectively.
  • Oleic acid acts as both an extraction solvent and a surfactant that can be adsorbed on the surface of copper particles.
  • Stable metallic copper fine particles can be obtained even in the presence of oxygen.
  • the method of the present invention makes it possible to obtain highly stable and hydrophobic nano-copper particles.
  • Figure 1 shows the experimental procedure used in this example. In a typical experiment, the two solutions were first mixed. One 0. In 2 MC u S 0 4 aqueous solution, and the other is a 0. 5 M O Rain monobasic ethanol kerosene acetone.
  • FIG. 2 shows a conceptual diagram of the reaction mechanism of the above example.
  • Metal copper fine particles were evaluated by different techniques.
  • the X-ray diffraction pattern was obtained with an X-ray diffractometer (XRD; XRD-6000, manufactured by Shimadzu Corporation) using Cu—Ka lines.
  • the form of the final product was determined by a photomicrograph taken with a scanning electron microscope (S-700).
  • the results of hydrophobic properties were evaluated by a flotation test (injecting 5 g of final product in 50 mL of distilled water).
  • the copper fine particles obtained by the above method were mixed with distilled water and stirred vigorously, and then the ratio of the suspended product to the total weight of the sample was measured. This ratio is called the active ratio. Higher active ratio means better hydrophobic properties.
  • Figure 3 shows an XRD pattern (Figure 3a), particle size distribution (Figure 3b), S of a representative sample obtained by reducing copper sulfate in a solution extracted using the process of the present invention. An EM photograph is shown (Fig. 3c, d).
  • Figure 4 shows the change in the hydrophobic properties of copper particles when the weight ratio of copper and oleic acid is varied.
  • Figure 4 shows that the synthesized copper fine particles are hydrophobic when the weight ratio of copper and oleic acid is changed from 3.25 wt% to 4.3 wt%. When this ratio changes from 3 2 to 65 wt%, the synthesized particles are hydrophilic.
  • Hydrophobic properties gradually decreased from 98.5 force to 0.1% when the weight ratio of copper to oleic acid changed from 3.25 to 65 wt%. 3. It can be concluded that with the reduction of the weight ratio to less than 25 wt%, the particle ratio of hydrophobic properties reaches nearly 100%.
  • the optimal weight ratio of copper and oleic acid is about 3.25 wt%. This is because when the weight ratio of copper and oleic acid is higher than 4.3 wt%, the hydrophobic functional group of oleic acid that reacts with the copper fine particles is not sufficient, and most of the copper fine particles cannot be covered. It is.
  • Oleic acid plays an important role throughout this process. It is first used as a phase transfer agent, and Cu 2+ ions in aqueous solution are first extracted into ethanolic oleate kerosene / acetone. The extracted metal ions are reduced to metal atoms with dalcose and ascorbic acid, respectively. Since metal atoms have high surface activity, the oleic acid extractant also acts as a surface active agent to modify the newly formed particle surface with the carboxyl end groups of oleic acid, and the hydrophobic force of oleic acid is It is arranged outside from the surface of the synthesized particles.
  • Oleic acid which protects copper particulates from oxidation, has another role in this process. It occurs between both the growth stage and the cleaning process. In the growth stage case, the steric effect resulting from the long alkyl chain of oleic acid on the surface of the copper particles may contribute to anti-oxygen. This is because the steric effect is largely determined by the oleic acid fragments covered on the surface of the copper particles. Therefore, it is necessary that there is sufficient oleic acid to adsorb on the copper particles. In the case of the cleaning process, the chemical bond between oleic acid and copper particulates may play an important role in preventing copper particulate oxidation.
  • the copper fine particles of the present invention exhibit high dispersibility regardless of nano-order.
  • the method for producing copper fine particles of the present invention is excellent in productivity and operability from the laboratory scale to the factory scale, and can synthesize copper fine particles that are easily oxidized in a stable manner. Thereby, the copper fine particles of the present invention can be effectively applied to various uses.

Abstract

Disclosed is a method for producing a copper microparticle, which comprises: a first reduction step for mixing an unsaturated fatty acid solution containing a copper ion with an aldose (a reducing monosaccharide) solution to form an emulsion; a second reduction step for adding an aqueous ascorbic acid solution to the emulsion; and a copper microparticle separation step. The method can produce a copper microparticle which has an average particle diameter of 100 nm or smaller and whose surface is partly or entirely modified with a carboxyl terminal group derived from the unsaturated fatty acid. The copper microparticle produced by the methodshows high dispersibility in spite of having a nano-order size.

Description

銅微粒子、 銅微粒子製造方法、 絶縁材料、 配線構造、 配線回路板の製造方法、 及 び電子 ·電気機器 技術分野 Copper fine particles, copper fine particle manufacturing method, insulating material, wiring structure, printed circuit board manufacturing method, and electronic / electric equipment technical field
本発明は、 高分散性のナノオーダ一の銅微粒子、 酸化されやすい銅微粒子を溶 媒中に安定に保持して合成する銅微明粒子製造方法に関するとともに、 該方法で合 成された銅微粒子を熱伝導体として有する絶縁材料、 該方法で合成された銅微粒 田  The present invention relates to a method for producing high-dispersibility nano-order copper fine particles and copper fine particles that stably synthesize copper fine particles that are easily oxidized in a solvent, and to synthesize the copper fine particles synthesized by the method. Insulating material having heat conductor, copper fine particles synthesized by the method
子を導電体として有する配線構造、 等に関する。 The present invention relates to a wiring structure having a child as a conductor.
金属ナノ粒子は、 極めて微小な粒径に起因する様々な特異な物性を示すことか ら、 導電材料、 着色材料、 コンデンサー、 バイオセンサー、 '化学センサー、 蛍光 材料、 偏光材料、 磁気メモリー材料などの種々の分野で利用されている。  Metal nanoparticles exhibit various unique properties due to their extremely small particle size, so conductive materials, coloring materials, capacitors, biosensors, 'chemical sensors, fluorescent materials, polarizing materials, magnetic memory materials, etc. It is used in various fields.
金属ナノ粒子の合成法は、ブレイクダゥン法とビルドアップ法に大別される力 金属は展性、 並びに延性に富むため主にビルドアップ法により製造されている。 また、 ビルドアップ法は乾式法と湿式法に区別され'、 多くの製造方法が開発され ている。  Metal nanoparticle synthesis methods are largely divided into break-down and build-up methods. Metals are mainly manufactured by the build-up method because they are highly malleable and ductile. In addition, the build-up method is classified into a dry method and a wet method, and many manufacturing methods have been developed.
乾式法での金属ナノ粒子製造方法としては、 ガス中蒸発法により金属ナノ粒子 を製造する方法が知られている。 また、 真空蒸着法により高分子マトリクス膜上 に金属を蒸着することにより金属ナノ粒子を製造する方法が知られている。 これ らの方法で得られる金属ナノ粒子は大変高濃度である上に、 不純物をほとんど含 まれない利点を有しているが、 粒度分布が広いため、 金属ナノ粒子の粒径に依存 する物性 （サイズ効果） を利用した用途には不適であった。 また、 これらの方法 では、 金属蒸気を作製するための特別な装置が必要であるため、 製造上、 不利で あった。  As a method for producing metal nanoparticles by dry method, a method of producing metal nanoparticles by gas evaporation method is known. In addition, a method for producing metal nanoparticles by depositing metal on a polymer matrix film by vacuum deposition is known. The metal nanoparticles obtained by these methods have a very high concentration and have the advantage of containing almost no impurities. However, since the particle size distribution is wide, the physical properties depend on the particle size of the metal nanoparticles ( It was unsuitable for applications using the size effect. In addition, these methods are disadvantageous in production because they require special equipment for producing metal vapor.
一方、溶液中で金属イオンを還元することにより金属ナノ粒子を得る湿式法は、 特別な設備を必要とせず、 スケールアップが容易である利点を有する。 生成した 金属ナノ粒子の凝集を防ぐため、 金属ナノ粒子表面に保護層を作製することが通 常である。 特開昭 5 9 - 1 7 3 2 0 6号公報には、 生産性の高い濃厚系で金属微粒子を合 成する方法として、 ポリオール法が開示されている。 ポリオール法は、 酸化銅の ような銅の酸化物又は塩をポリオール中で加熱還元する方法であり、 ポリオール は溶媒、 還元剤、 保護剤の三つの役割を担っている。 その結果、 濃厚系でもサブ ミクロンないしミクロンォータ'一の金属微粒子を得ることができる。 On the other hand, the wet method of obtaining metal nanoparticles by reducing metal ions in solution does not require special equipment and has the advantage of being easy to scale up. In order to prevent agglomeration of the generated metal nanoparticles, it is usual to form a protective layer on the surface of the metal nanoparticles. Japanese Patent Application Laid-Open No. 59-1717 3206 discloses a polyol method as a method for synthesizing metal fine particles in a highly productive dense system. The polyol method is a method in which a copper oxide or salt such as copper oxide is heated and reduced in a polyol, and the polyol plays three roles: a solvent, a reducing agent, and a protective agent. As a result, it is possible to obtain submicron or micrometer metal particles even in a dense system.
このポリオール法では、 ポリオールの種類、 反応温度、 原料などを調製するこ とによって、 微細な金属微粒子を得られることが知られている。 しかし、 通常の ポリオール法においては、 特に銅微粒子の場合、 粒径が 1 0 0 n m以下の分散性 の優れた銅微粒子の合成は極めて困難であった。  In this polyol method, it is known that fine metal fine particles can be obtained by preparing the kind of polyol, reaction temperature, raw materials and the like. However, in the usual polyol method, particularly in the case of copper fine particles, it was extremely difficult to synthesize copper fine particles having a particle size of 100 nm or less and excellent dispersibility.
特開 2 0 0 5— 3 0 7 3 3 5号公報には、 大量生産に適した液相法であるポリ オール法を応用し、粒径が 1 0 0 n m以下と微細で且つその均一性が極めて高く、 分散性及び耐酸化性に優れた銅微粒子を得ることを目的として、 銅の酸化物、 水 酸化物又は塩をエチレングリコール、 ジエチレングリコール又はトリエチレング リコール溶液中で加熱還元して銅微粒子を得る方法において、 核生成のための P dや A gなどの貴金属イオンを添加すると共に、 分散剤としてポリビエルピロリ ドン、 還元反応制御剤としてアミン系有機化合物を添加し、 必要に応じてアル力 リ性無機化合物を添加して、貴金属 を微量に含有する銅微粒子を得、 この溶液を 極性溶媒で溶媒置換、 濃縮することで、 銅微粒子分散液を得ることが開示されて いる。  In Japanese Patent Laid-Open No. 2 0 5-3 0 7 3 3 5, the polyol method, which is a liquid phase method suitable for mass production, is applied, and the particle size is as fine as 100 nm or less and its uniformity. In order to obtain copper fine particles with extremely high dispersibility and oxidation resistance, copper oxides, hydroxides or salts are heated and reduced in ethylene glycol, diethylene glycol or triethylene glycol solutions to obtain copper fine particles. In addition to adding precious metal ions such as Pd and Ag for nucleation, add polyvinylpyrrolidone as a dispersant and an amine organic compound as a reduction reaction control agent. It is disclosed that a copper fine particle dispersion is obtained by adding a copper-containing inorganic compound to obtain copper fine particles containing a trace amount of a noble metal, and substituting and concentrating the solution with a polar solvent.
ところで、 パーソナルコンピュータ、 携帯電話、 ディジタルスチルカメラ、 液 晶テレビ等の電子装置は、 種々の分野において用いられている。 これらの電子装 置は、 例えば、 T F T (薄膜トランジスタ） 、 配線等を多数有する T F Tアレイ 基板等の回路基板を備えている。  Incidentally, electronic devices such as personal computers, mobile phones, digital still cameras, and liquid crystal televisions are used in various fields. These electronic devices include, for example, a circuit board such as a TFT array substrate having a number of TFTs (thin film transistors) and wirings.
このような回路基板は、 一般的に、 C V D (化学蒸着） やスパッタリング等の 気相堆積法により成膜した薄膜のうち、 不要な部分をフォトリソグラフィ等によ り除去 （エッチング） するといつたプロセスを複数回繰り返すことにより形成さ れる。  Such a circuit board is generally processed when an unnecessary portion of a thin film formed by vapor deposition such as CVD (chemical vapor deposition) or sputtering is removed (etched) by photolithography or the like. Is formed by repeating a plurality of times.
しかしながら、 このような従来の製造方法は、 成膜とエッチングとを繰り返し 行うため、 原料の使用効率が悪く、 また、 エッチング溶液等の廃棄物が多く発生 し、 処理コストが嵩むと共に、 製造時間が長くかかるといった問題点や、 各成膜 工程に使用される成膜装置およびエッチング装置等の加工装置等、 多くの真空装 置を必要とすることから、 例えば T F Tアレイ基板等、 近年さらなる大型化が要 望されている回路基板の製造に、 莫大な設備費が必要となるといつた問題点を有 している。 However, such a conventional manufacturing method repeats film formation and etching, so that the use efficiency of raw materials is poor, and a large amount of waste such as an etching solution is generated. However, since the processing cost increases and the manufacturing time is long, and a large number of vacuum devices such as a film forming apparatus and a processing apparatus such as an etching apparatus used in each film forming process are required. For example, there is a problem when enormous equipment costs are required for the production of circuit boards that are required to be further enlarged in recent years, such as TFT array substrates.
そこで、 近年、 導電性微粒子を含有する液体材料を所望の領域に吐出すること により、被吐出物を含む所望のパターンを形成するいわゆるインクジヱット法（液 滴吐出法）により上記回路基板における配線等を形成する技術が提案されている。 例えば、 特開 2 0 0 3 _ 3 1 8 1 9 2号公報には、 金、 銀、 銅、 パラジウム、 ニッケルの何れかを含有する金属微粒子を含有する液体材料の一例として、 粒径 0 . 0 1 μ m程度の銀の微粒子を有機溶媒に分散させてなるペーストを用いてィ ンクジヱット法により配線を形成することが開示されている。 発明の開示  Therefore, in recent years, the wiring on the circuit board is formed by a so-called ink jet method (liquid droplet discharge method) in which a liquid material containing conductive fine particles is discharged to a desired region to form a desired pattern including an object to be discharged. A forming technique has been proposed. For example, in Japanese Patent Application Laid-Open No. 2000-3_3 1 8 1 92, as an example of a liquid material containing fine metal particles containing any one of gold, silver, copper, palladium, and nickel, a particle size of 0. 0 It is disclosed that a wiring is formed by an ink jet method using a paste in which silver fine particles of about 1 μm are dispersed in an organic solvent. Disclosure of the invention
上記従来技術の問題点のように、 湿式法で煩雑な工程を経ることなく、 高濃度 のナノオーダーの銅微粒子の製造方法が望まれていた。  As a problem of the above prior art, there has been a demand for a method for producing high-concentration nano-order copper fine particles without going through complicated steps in a wet method.
本発明は、 高分散性のナノオーダーの銅微粒子、 酸化されやすい銅微粒子を溶 媒中に安定に保持して合成する銅微粒子製造方法に関するとともに、 該方法で合 成された銅微粒子を熱伝導体として有する絶縁材料、 該方法で合成された銅微粒 子を導電体として有する配線構造、 等を提供することを目的とする。  The present invention relates to a method for producing highly dispersed nano-order copper fine particles and a copper fine particle that is synthesized by stably holding copper fine particles that are easily oxidized in a solvent, and heat conduction of the copper fine particles synthesized by the method. It is an object to provide an insulating material having a body, a wiring structure having a copper fine particle synthesized by the method as a conductor, and the like.
本発明者らは、 特定の弱い還元剤を複数種用いる湿式法によって上記課題が解 決できることを見出し、 本発明に到達した。  The present inventors have found that the above problem can be solved by a wet method using a plurality of specific weak reducing agents, and have reached the present invention.
即ち、 第 1に、 本発明は、 銅微粒子 （ナノ粒子） の発明であり、 平均粒径が 1 That is, first, the present invention is an invention of copper fine particles (nanoparticles), and the average particle size is 1
O O n m以下であり、 表面の一部又は全部が不飽和脂肪酸のカルボキシル末端基 で修飾されたことを特徴とする。 本発明の銅微粒子は、 不飽和脂肪酸のカルボキ シル末端基で修飾されることによって、 平均粒径が 1 0 0 n m以下のナノ粒子に もかかわらず、 凝集することなく高い分散性を示す。 O Onm or less, and part or all of the surface is modified with a carboxyl end group of an unsaturated fatty acid. The copper fine particles of the present invention are highly dispersible without being agglomerated by being modified with a carboxyl end group of an unsaturated fatty acid, regardless of nanoparticles having an average particle size of 100 nm or less.
ここで、 前記不飽和脂肪酸としては、 炭素数 8〜2 0の 1個又は 2個以上の C Here, as the unsaturated fatty acid, one or two or more C having 8 to 20 carbon atoms is used.
= Cの 2重結合を有するものを用いることが出来る。 その中で、 ォレイン酸が好 ましく例示される。 Those with a double bond of = C can be used. Of these, oleic acid is preferred. A good example.
本発明の銅微粒子は、 表面に修飾される不飽和脂肪酸の割合によつて、 親水性 から疎水性までその性質を調整することが出来る。 特に、 銅微粒子の表面の多く が不飽和脂肪酸のカルボキシル末端基で修飾された場合は疎水性を示す。  The properties of the copper fine particles of the present invention can be adjusted from hydrophilic to hydrophobic depending on the proportion of unsaturated fatty acids modified on the surface. In particular, when most of the surface of the copper fine particle is modified with a carboxyl end group of an unsaturated fatty acid, it shows hydrophobicity.
第 2に、 本発明は、 上記の銅微粒子の製造方法の発明であり、 銅イオンを含む 不飽和脂肪酸溶液とアルドース （還元性単糖類） 溶液を混合してェマルジヨンを 形成する 1次還元工程と、 該ェマルジヨ ンにァスコルビン酸水溶液を加える 2次 還元工程と、 銅微粒子分離工程とを有する。  Second, the present invention is an invention of the above-described method for producing copper fine particles, comprising a primary reduction step in which an unsaturated fatty acid solution containing copper ions and an aldose (reducing monosaccharide) solution are mixed to form an emulsion. A secondary reduction step of adding an ascorbic acid aqueous solution to the emulsion and a copper fine particle separation step.
本発明の銅微粒子製造方法において、 弱い還元性の点から、 前記不飽和脂肪酸 としてォレイン酸が好ましく例示され、 前記アルドース （還元性単糖類） として グルコースが好ましく例示される。  In the copper fine particle production method of the present invention, oleic acid is preferably exemplified as the unsaturated fatty acid, and glucose is preferably exemplified as the aldose (reducing monosaccharide) from the viewpoint of weak reducibility.
本発明の銅微粒子製造方法において、 銅イオンとォレイン酸の重量比が 4 . 3 w t %以下である場合に、 銅微粒子の表面の多くが不飽和脂肪酸のカルボキシル 末端基で修飾されて疎水性を示す。  In the method for producing copper fine particles of the present invention, when the weight ratio of copper ions to oleic acid is 4.3 wt% or less, most of the surfaces of the copper fine particles are modified with carboxyl end groups of unsaturated fatty acids to make them hydrophobic. Show.
銅は貴金属と比較して酸化されやすく、 従来は、 ナノ粒子を金属状態で溶媒中 に保持して合成することが困難であった。 本発明では、 銅イオンを含むォレイン 酸溶液 Aと、 弱い還元剤であるグルコース水溶液 B、 およびァスコルビン酸水溶 液 Cを使うプロセスにより、 銅ナノ粒子を合成した。 グルコースにより一酸化銅 にまでの一次還元してナノ形状固体をつく り、 その後ァスコルビン酸により二次 還元して銅ナノ粒子とする。 使用する化学薬品は、 銅イオンを還元する作用の他 に銅が再酸化するのを抑制する。 Aと Bを混ぜて攪拌するとェマルジヨ ンつく り、 該ェマルジョン表面で 1次還元がおきる。 これに Cを加えると Aと Cはェマルジ ョン化し二次還元が起きる。 ェマルジョン化した液は誘導体であるリン酸を少量 添加して数分後には一層に分離する A液中では収率 1 0重量パセント以上で銅が 回収できる。  Copper is more easily oxidized than noble metals, and it has been difficult to synthesize by holding nanoparticles in a solvent in a metal state. In the present invention, copper nanoparticles were synthesized by a process using an oleic acid solution A containing copper ions, a weak reducing agent, an aqueous glucose solution B, and an ascorbic acid aqueous solution C. A nano-shaped solid is produced by primary reduction to copper monoxide with glucose, and then secondarily reduced with ascorbic acid to form copper nanoparticles. The chemicals used prevent copper from being reoxidized in addition to reducing copper ions. When A and B are mixed and stirred, an emulsion is formed, and primary reduction occurs on the surface of the emulsion. When C is added to this, A and C are emulsified and secondary reduction occurs. The emulsified liquid is added with a small amount of the derivative phosphoric acid and then separated further after a few minutes. In the liquid A, copper can be recovered at a yield of 10 weight percent or more.
第 3に、 本発明は、 上記の銅微粒子の応用に関するものであり、 ポリマーマト リ ックス中に、 平均粒径が 1 0 0 n m以下であり、 表面の一部又は全部が不飽和 脂肪酸のカルボキシル末端基で修飾された銅微粒子が分散されていることを特徴 とする絶縁材料である。 ここで、 前記不飽和脂肪酸としてォレイン酸が好ましい ことは上述の通りである。 含有された銅微粒子が優れた熱伝導性を有するととも に、 ポリマーマトリ ックスによって絶縁材料となる。 これにより、 放熱性、 熱伝 導性に優れた絶縁材料となる。 Third, the present invention relates to the application of the above copper fine particles, wherein the polymer matrix has an average particle size of 100 nm or less, and a part or all of the surface is a carboxyl terminal of unsaturated fatty acid. It is an insulating material characterized in that copper fine particles modified with a group are dispersed. Here, oleic acid is preferable as the unsaturated fatty acid. This is as described above. The contained copper fine particles have excellent thermal conductivity and become an insulating material by a polymer matrix. As a result, the insulating material is excellent in heat dissipation and thermal conductivity.
第 4に、 本発明は、 上記の銅微粒子の他の応用に関するものであり、 回路基板 内の配線溝、 ビアホール、 コンタク トホール及び貫通孔から選ばれる凹部又は孔 に、 平均粒径が 1 0 0 n m以下であり、 表面の一部又は全部が不飽和脂肪酸の力 ルポキシル末端基で修飾された銅微粒子が充填されていることを特徴とする配線 構造である。 ここで、 前記不飽和脂肪酸としてォレイン酸が好ましいことは上述 の通りである。 ナノオーダーの銅微粒子を導電材料とすることでファインピッチ の配線回路となる。  Fourthly, the present invention relates to another application of the above-mentioned copper fine particles, and the average particle size is 10 0 in a recess or a hole selected from a wiring groove, a via hole, a contact hole and a through hole in a circuit board. The wiring structure is characterized in that a part or all of the surface is filled with fine copper particles modified with unsaturated fatty acid force lpoxyl end groups. Here, as described above, oleic acid is preferable as the unsaturated fatty acid. By using nano-order copper fine particles as a conductive material, it becomes a fine-pitch wiring circuit.
第 5に、 本発明は、 上記の配線構造を有する配線回路板の製造方法であり、 回 路基板内の配線溝、 ビアホール、 コンタク トホール及び貫通孔から選ばれる凹部 又は孔に、 銅イオンを含む不飽和脂肪酸溶液とグルコース溶液を混合してェマル ジョンを形成する 1次還元工程と、 該ェマルジョンにァスコルビン酸水溶液を加 える 2次還元工程と、 銅微粒子分離工程により製造された銅微粒子を充填するこ とを特徴とする。 ここで、 前記不飽和脂肪酸としてォレイン酸が好ましいことは 上述の通りである。  Fifth, the present invention is a method for manufacturing a printed circuit board having the above-described wiring structure, and includes copper ions in a recess or a hole selected from a wiring groove, a via hole, a contact hole, and a through hole in a circuit board. A primary reduction process in which an unsaturated fatty acid solution and a glucose solution are mixed to form an emulsion, a secondary reduction process in which an aqueous ascorbic acid solution is added to the emulsion, and copper fine particles produced by the copper fine particle separation process are filled. It is characterized by this. Here, as described above, oleic acid is preferable as the unsaturated fatty acid.
回路基板内の配線溝、 ビアホール、 コンタク トホール及び貫通孔から選ばれる 少なくとも一つの凹部又は孔への、 銅微粒子の充填方法としては、 スク リーン印 刷法、 デイスペンス法、 インクジェット法又はスピンコート法が好ましく例示さ れる。  As a method for filling copper fine particles into at least one recess or hole selected from wiring grooves, via holes, contact holes and through holes in a circuit board, a screen printing method, a dispense method, an ink jet method, or a spin coating method can be used. Preferably exemplified.
第 6に、 本発明は、 上記の銅微粒子を含有する絶縁材料を有する電子 '電気機 器である。  Sixth, the present invention is an electronic device having an insulating material containing the above copper fine particles.
第 7に、 本発明は、 上記の銅微粒子を含有する絶縁材料を有する配線構造を有 する電子 '電気機器である。  Seventh, the present invention is an electronic device having a wiring structure having an insulating material containing the above copper fine particles.
本発明の銅微粒子は、 ナノオーダーにもかかわらず、 高分散性を示す。 また、 本発明の銅微粒子の製造方法は、 実験室規模から工場規模まで生産性と操作性に 優れるとともに、 酸化されやすい銅微粒子を溶媒中に安定に保持して合成するこ とが出来る。 また、 本発明の銅微粒子を熱伝導体として有する絶縁材料は、 高い 熱伝導性を有する有用な絶縁材料であり、 本発明の銅微粒子を導電体として有す る配線構造は、 ファインピッチの配線回路を実現する。 図面の簡単な説明 The copper fine particles of the present invention exhibit high dispersibility regardless of nano-order. In addition, the method for producing copper fine particles of the present invention is excellent in productivity and operability from the laboratory scale to the factory scale, and can synthesize copper fine particles that are easily oxidized in a stable manner. In addition, the insulating material having the copper fine particles of the present invention as a heat conductor is expensive. The wiring structure which is a useful insulating material having thermal conductivity and has the copper fine particles of the present invention as a conductor realizes a fine pitch wiring circuit. Brief Description of Drawings
図 1は、 本実施例で用いた実験手順を示す。  Figure 1 shows the experimental procedure used in this example.
図 2は、 本実施例の反応機構の概念図を示す。  FIG. 2 shows a conceptual diagram of the reaction mechanism of this example.
図 3は、 本発明のプロセスを用いて抽出された溶液中で硫酸銅を還元すること により得られた代表的なサンプルの X R Dパターン（図 3 a )、粒子サイズ分布（図 3 b )、 S E M写真を示す （図 3 c、 d )。  Figure 3 shows an XRD pattern (Figure 3a), particle size distribution (Figure 3b), SEM of a representative sample obtained by reducing copper sulfate in a solution extracted using the process of the present invention. A photograph is shown (Fig. 3c, d).
図 4は、 銅とォレイン酸の重量比を変えて合成した場合の、 銅微粒子の疎水特 性の変化を示す。 発明を実施するための最良の形態  Figure 4 shows the change in the hydrophobic properties of copper particles when synthesized with varying weight ratios of copper and oleic acid. BEST MODE FOR CARRYING OUT THE INVENTION
本発明の銅微粒子を製造する際に用いる不飽和脂肪酸としては、 炭素数 8〜 2 0の 1個又は 2個以上の C = Cの 2重結合を有するものを用いることが出来る。 具体的には、 不飽和結合を 1つ持つモノ不飽和脂肪酸である、 ミ リス トレイン酸 (炭素数 1 4の 9 _モノ不飽和脂肪酸）、パルミ トレイン酸（炭素数 1 6の c i s 9一モノ不飽和脂肪酸）、ォレイン酸（炭素数 1 7の c i s— 9一モノ不飽和脂肪 酸）、 エライジン酸 （炭素数 1 7の. t r a n s — 9—モノ不飽和脂肪酸、 ォレイン 酸の t r a n s異性体）、 パクセン酸 （炭素数 1 7の 1 1—モノ不飽和脂肪酸）、 ガドレイン酸（c i s— 9一モノ不飽和脂肪酸）、不飽和結合を 2つ持つジ不飽和 脂肪酸である、 リノール酸 （炭素数 1 7の c i s - 9 - c i s— 1 2—ジ不飽和 脂肪酸）、 不飽和結合を 3つ持つトリ不飽和脂肪酸である、 α—リノレン酸 （炭素 数 1 7の 9 , 1 2 , 1 5—トリ不飽和脂肪酸）、 エレォステアリン酸 （炭素数 1 7 の 9 , 1 1 , 1 3—トリ不飽和脂肪酸） 等が挙げられる。 これらの中で、 ォレイ ン酸が好ましく例示される。 As the unsaturated fatty acid used for producing the copper fine particles of the present invention, those having 1 or 2 or more C = C double bonds having 8 to 20 carbon atoms can be used. Specifically, mono-unsaturated fatty acids having one unsaturated bond, myristoleic acid (9_monounsaturated fatty acid having 14 carbon atoms), palmitoleic acid (cis 9 mono-carbon having 16 carbon atoms) Unsaturated fatty acid), oleic acid (cis mono-unsaturated fatty acid with 1-7 carbon atoms), elaidic acid (1-7 carbon atoms. Trans — 9-monounsaturated fatty acid, trans isomer of oleic acid), Paxenoic acid (1 1-monounsaturated fatty acid with 1 to 7 carbon atoms), gadoleic acid (cis-9 mono-unsaturated fatty acid), diunsaturated fatty acid with two unsaturated bonds, linoleic acid (1 carbon number) 7 -cis-9-cis- 1 2-diunsaturated fatty acid), a tri-unsaturated fatty acid with three unsaturated bonds, α -linolenic acid (9, 1 2, 1 5-carbon with 1 7 carbons) Unsaturated fatty acids), eleostearic acid (9,11,13-triunsaturated fatty acids having 1 to 7 carbon atoms), etc. That. Of these, oleic acid is preferably exemplified.
本発明の銅微粒子を製造する際に用いるアルドース （還元性単糖類） は、 鎖の 末端にアルデヒ ド基を 1つ持つ単糖類であり、 D体及び L体が存在する。 具体的 には、 アルドトリオース、 ダリセルアルデヒ ド、 アルドテトロース、 エリ トロー ス、 トレオース、 ァノレドペントース、 リボース、 リキソース、 キシロース、 ァラ ビノース、 ァノレドへキソース、 ァロース、 タロース、 グロース、 グノレコース、 ァ ノレトロース、 マンノース、 ガラク トース、 ィ ドース、 フノレク トース等が挙げられ る。 これらの中で、 グルコースが好ましく例示される。 The aldose (reducing monosaccharide) used in producing the copper fine particles of the present invention is a monosaccharide having one aldehyde group at the end of the chain, and there exist D-form and L-form. Specifically, aldtriose, darrisel aldehyde, aldetrose, erythro Sucrose, throse, anoled pentose, ribose, lyxose, xylose, arabinose, anoledo hexose, sucrose, talose, growth, gnolecose, ano-reose, mannose, galactose, idose, funo lectose. Among these, glucose is preferably exemplified.
グルコース等は、 水溶液中ではごく一部が鎖状構造となっており、 この構造の 末端にはアルデヒ ド基が存在するため、 グルコース等の水溶液は還元性を示す。 本発明の銅微粒子を製造する際に用いるァスコルビン酸は、 水素原子を 2個放 出してデヒ ドロアスコルビン酸に変わる。  A part of glucose and the like has a chain structure in an aqueous solution, and an aldehyde group is present at the end of this structure, so that an aqueous solution of glucose and the like shows reducibility. Ascorbic acid used in producing the copper fine particles of the present invention is converted into dehydroascorbic acid by releasing two hydrogen atoms.
以下、 本発明の、 抽出一 2段階法を用いた銅微粒子の合成とサイズ、 形、 サイ ズ分布の評価の結果を説明する。  Hereinafter, the results of the synthesis of copper fine particles and the evaluation of size, shape, and size distribution using the two-step extraction method of the present invention will be described.
[銅微粒子の合成]  [Synthesis of copper fine particles]
本発明の方法で、最初に水溶液中の C u 2 +イオンはォレイン酸の中に抽出した。 そして、抽出された C u 2 +イオンはグルコースとァスコルピン酸によりそれぞれ 酸化銅 （ I ) と金属銅に還元した。 ォレイン酸は抽出溶媒と銅粒子の表面に吸着 できる表面活性剤の両方として働く。 安定な金属銅微粒子は酸素が存在している 中でも得ることができる。 本発明の方法は、 高い安定と疎水性のナノ銅粒子を得 ることを可能にする。 同時に、 ォレイン酸の C = C結合の存在は潜在的工業プロ セスアプリケーションに重要な高分子マトリタスと最終生成物を容易に反応させ る。 In the method of the present invention, Cu 2 + ions in an aqueous solution were first extracted into oleic acid. The extracted Cu 2+ ions were reduced to copper oxide (I) and copper metal by glucose and ascorpic acid, respectively. Oleic acid acts as both an extraction solvent and a surfactant that can be adsorbed on the surface of copper particles. Stable metallic copper fine particles can be obtained even in the presence of oxygen. The method of the present invention makes it possible to obtain highly stable and hydrophobic nano-copper particles. At the same time, the presence of the C = C bond in oleic acid facilitates the reaction of the final product with the high molecular weight matrix that is important for potential industrial process applications.
図 1に、 本実施例で用いた実験手順を示す。 典型的な実験では、 最初に 2種類 の溶液を混合した。 1つは 0 . 2 M C u S 0 4水溶液で、 もう 1つは 0 . 5 Mォ レイン酸一エタノール 灯油 アセトン溶液である。 Figure 1 shows the experimental procedure used in this example. In a typical experiment, the two solutions were first mixed. One 0. In 2 MC u S 0 4 aqueous solution, and the other is a 0. 5 M O Rain monobasic ethanol kerosene acetone.
そして、 混合した溶液は抽出の平衡に達するために、 ノーマル条件で 3 0分間 振った。 有機溶媒中に抽出された銅イオンは、 グルコースとァスコルビン酸溶液 によりそれぞれ還元した。 反応溶液は系の均一性を維持し、 反応が終了するまで 析出した粒子の分散を保っために、 適度な速度で攪拌した。 熟成 2時間後、 析出 物は遠心分離機により液体溶液から分離し、 その後、 それを蒸留水とアルコール で透明溶液が得られるまで数回洗浄した。 最終的な粉末は真空乾燥機を用いて 4 時間、 3 3 3 Kで乾燥させた。 図 2に、 上記実施例の反応機構の概念図を示す。 The mixed solution was shaken for 30 minutes under normal conditions to reach the equilibrium of extraction. Copper ions extracted into the organic solvent were reduced with glucose and ascorbic acid solution, respectively. The reaction solution was stirred at an appropriate speed in order to maintain the homogeneity of the system and keep the precipitated particles dispersed until the reaction was completed. After 2 hours of aging, the precipitate was separated from the liquid solution by a centrifuge, and then washed several times with distilled water and alcohol until a clear solution was obtained. The final powder was dried at 33.33 K for 4 hours using a vacuum dryer. FIG. 2 shows a conceptual diagram of the reaction mechanism of the above example.
[銅微粒子の評価]  [Evaluation of copper fine particles]
金属銅微粒子の評価は異なるテクニックにより行った。 X線回折パターンは、 C u— K a線を用い、 X線回折装置 （XRD ; XRD— 6000, 島津製作所製) により得た。 最終生成物の形態は、 走査型電子顕微鏡 （S— 700) で撮影した 顕微鏡写真により決定した。 疎水特性の結果は、 浮遊試験 （50mLの蒸留水中 に 5 gの最終生成物を投入） により評価した。 上記方法で得られた銅微粒子を蒸 留水に混合し、 勢いよく攪拌した後、 浮遊した生成物と試料の全重量の比を測定 した。 この比は、 アクティブ比率と呼ぶ。 アクティブ比率が高いと疎水特性はよ り良いことを意味する。  Metal copper fine particles were evaluated by different techniques. The X-ray diffraction pattern was obtained with an X-ray diffractometer (XRD; XRD-6000, manufactured by Shimadzu Corporation) using Cu—Ka lines. The form of the final product was determined by a photomicrograph taken with a scanning electron microscope (S-700). The results of hydrophobic properties were evaluated by a flotation test (injecting 5 g of final product in 50 mL of distilled water). The copper fine particles obtained by the above method were mixed with distilled water and stirred vigorously, and then the ratio of the suspended product to the total weight of the sample was measured. This ratio is called the active ratio. Higher active ratio means better hydrophobic properties.
図 3に、 本発明のプロセスを用いて抽出された溶液中で硫酸銅を還元すること により得られた代表的なサンプルの XRDパターン（図 3 a )、粒子サイズ分布（図 3 b)、 S EM写真を示す （図 3 c、 d)。  Figure 3 shows an XRD pattern (Figure 3a), particle size distribution (Figure 3b), S of a representative sample obtained by reducing copper sulfate in a solution extracted using the process of the present invention. An EM photograph is shown (Fig. 3c, d).
図 3 aにおけるすべてのピークは、 純銅 （J CPDS No. 04— 0836) を示す。 図 3 より、 粉末の平均粒子サイズはデバイ—シヱラ式を使って最も強 度の高いピークの半値幅から約 50 nmであると計算された。図 3 cと図 3 dは、 合成された銅粒子の代表的なサンプルの S EM写真を示す。 その S EM写真は、 生成物が球状粒子からなっていることを明らかにするとともに、 すべてのナノ粒 子はよく分散していることを示している。 S EM写真から見積もった平均粒径は 50— 60 nmであった。  All peaks in Figure 3a indicate pure copper (J CPDS No. 04—0836). From Fig. 3, the average particle size of the powder was calculated to be about 50 nm from the half-width of the strongest peak using the Debye-Shira formula. Figures 3c and 3d show SEM photographs of representative samples of synthesized copper particles. The SEM picture reveals that the product is composed of spherical particles and that all the nanoparticles are well dispersed. The average particle size estimated from SEM photographs was 50-60 nm.
サイズ分布は図 3 bで示したヒストグラムにより与えられる。 図 3わより、 こ の粉末は明らかに狭い粒度分布を持っていることがわかる。 また、 これらの粒子 の平均直径は 55 nmと見積もられた。 この値は X R Dで分析した値、 および S EMで見積もった値と一致した。 以上より、 本発明のプロセスにより、 均一でよ く分散した銅ナノ粒子を合成することができるといえる。  The size distribution is given by the histogram shown in Figure 3b. Figure 3 shows that this powder has a clearly narrow particle size distribution. The average diameter of these particles was estimated to be 55 nm. This value was consistent with the value analyzed by XRD and estimated by SEM. From the above, it can be said that uniform and well dispersed copper nanoparticles can be synthesized by the process of the present invention.
[銅微粒子の疎水特性に及ぼす銅とォレイン酸の重量比の影響]  [Effect of weight ratio of copper and oleic acid on hydrophobic properties of copper fine particles]
次に、 合成された銅微粒子の疎水特性に及ぼす銅とォレイン酸の重量比の影響 を調べるために、 ォレイン酸量を変化させ、 他の実験条件は固定して銅微粒子を 合成した。 図 4に、 銅とォレイン酸の重量比を変えて合成した場合の、 銅微粒子の疎水特 性の変化を示す。 図 4より銅とォレイン酸の重量比が 3. 2 5 w t %から 4. 3 w t %へと変化したとき、 合成された銅微粒子は疎水性であることが分かる。 こ の比が 3 2から 6 5 w t %へと変化したとき、 合成された粒子は親水性である。 疎水性特性は、 銅とォレイン酸の重量比が 3. 2 5から 6 5 w t %へ変化したと き、 徐々に 9 8. 5力 ら 0. 1 %へと減少した。 3. 2 5 w t %未満までの重量 比の減少で、 疎水特性の粒子比が 1 00 %近くに達すると結論付けることができ る。 Next, in order to investigate the influence of the weight ratio of copper and oleic acid on the hydrophobic properties of the synthesized copper fine particles, the amount of oleic acid was varied, and other experimental conditions were fixed to synthesize copper fine particles. Figure 4 shows the change in the hydrophobic properties of copper particles when the weight ratio of copper and oleic acid is varied. Figure 4 shows that the synthesized copper fine particles are hydrophobic when the weight ratio of copper and oleic acid is changed from 3.25 wt% to 4.3 wt%. When this ratio changes from 3 2 to 65 wt%, the synthesized particles are hydrophilic. Hydrophobic properties gradually decreased from 98.5 force to 0.1% when the weight ratio of copper to oleic acid changed from 3.25 to 65 wt%. 3. It can be concluded that with the reduction of the weight ratio to less than 25 wt%, the particle ratio of hydrophobic properties reaches nearly 100%.
したがって、 最適な銅とォレイン酸の重量比は約 3. 2 5 w t %であることが わかる。 なぜならば、 銅とォレイン酸の重量比が 4. 3 w t %より多い場合、 銅 微粒子と反応するォレイン酸の疎水性機能グループが十分でなく、 銅微粒子のほ とんどを覆うことができないからである。  Therefore, it can be seen that the optimal weight ratio of copper and oleic acid is about 3.25 wt%. This is because when the weight ratio of copper and oleic acid is higher than 4.3 wt%, the hydrophobic functional group of oleic acid that reacts with the copper fine particles is not sufficient, and most of the copper fine particles cannot be covered. It is.
ォレイン酸はこのプロセスの間中、 重要な役割を演じる。 それは、 はじめに相 間移動剤として使われ、水溶液中の C u 2 +イオンは最初にォレイン酸 エタノ一 ル 灯油/アセ トン中に抽出される。 そして、 抽出された金属イオンはダルコ一 スとァスコルビン酸でそれぞれ金属原子へ還元される。 金属原子は高い表面活性 を持つので、 抽出剤であるォレイン酸はまた新しく生成した粒子表面をォレイン 酸のカルボキシル末端基で修飾するための表面活性剤として働き、 ォレイン酸の 疎水性力一ボンティルは合成された粒子の表面から外側に配置される。 Oleic acid plays an important role throughout this process. It is first used as a phase transfer agent, and Cu 2+ ions in aqueous solution are first extracted into ethanolic oleate kerosene / acetone. The extracted metal ions are reduced to metal atoms with dalcose and ascorbic acid, respectively. Since metal atoms have high surface activity, the oleic acid extractant also acts as a surface active agent to modify the newly formed particle surface with the carboxyl end groups of oleic acid, and the hydrophobic force of oleic acid is It is arranged outside from the surface of the synthesized particles.
酸化から銅微粒子を保護しているォレイン酸はこのプロセスでは別の役割であ る。それは成長段階と洗浄プロセスの両方の間で起こる。成長段階のケースでは、 銅粒子の表面にォレイン酸の長いアルキル鎖から生じる s t e r i c効果は反酸 素に貢献するかもしれない。 なぜなら、 s t e r i c効果は銅粒子表面に覆われ たォレイン酸の断片によって大きく決定されるからであり、 したがって、 銅微粒 子の上に吸着するために十分なォレイン酸があることが必要である。 洗浄プロセ スのケースでは、 ォレイン酸と銅微粒子の間の化学結合は、 銅微粒子の酸化防止 に重要な役割を演じるかもしれない。 なぜならば、 水やアルコールでの数回の洗 浄では銅微粒子の表面上から完全にォレイン酸を取り除くことはできなかったの で、 このポイントもまた、 疎水性実験結果から誘導することができる。 これらの 実験は、 s t e r i c効果が洗浄の過程で現れることを含意する。 本発明は、 1 プロセスにおけるナノ銅粒子の合成と非酸化を実現する。 産業上の利用可能性 Oleic acid, which protects copper particulates from oxidation, has another role in this process. It occurs between both the growth stage and the cleaning process. In the growth stage case, the steric effect resulting from the long alkyl chain of oleic acid on the surface of the copper particles may contribute to anti-oxygen. This is because the steric effect is largely determined by the oleic acid fragments covered on the surface of the copper particles. Therefore, it is necessary that there is sufficient oleic acid to adsorb on the copper particles. In the case of the cleaning process, the chemical bond between oleic acid and copper particulates may play an important role in preventing copper particulate oxidation. This is also derived from the results of hydrophobicity experiments, because several washings with water or alcohol did not completely remove oleic acid from the surface of the copper microparticles. these The experiment implies that a steric effect appears in the course of cleaning. The present invention achieves the synthesis and non-oxidation of nano copper particles in one process. Industrial applicability
本発明の銅微粒子は、 ナノオーダーにもかかわらず、 高分散性を示す。 また、 本発明の銅微粒子の製造方法は、 実験室規模から工場規模まで生産性と操作性に 優れるとともに、 酸化されやすい銅微粒子を溶媒中に安定に保持して合成するこ とが出来る。 これにより、 本発明の銅微粒子は、 各種用途に効果的に適用するこ とが出来る。  The copper fine particles of the present invention exhibit high dispersibility regardless of nano-order. In addition, the method for producing copper fine particles of the present invention is excellent in productivity and operability from the laboratory scale to the factory scale, and can synthesize copper fine particles that are easily oxidized in a stable manner. Thereby, the copper fine particles of the present invention can be effectively applied to various uses.

Claims

求 の 範 Range of requests
平均粒径が 1 0 0 n m以下であり、 表面の一部又は全部が不飽和脂肪酸のカル ボキシル末端基で修飾されたことを特徴とする銅微粒子。 A copper fine particle characterized by having an average particle size of 100 nm or less and a part or all of the surface modified with a carboxyl end group of an unsaturated fatty acid.
2 .  2.
前記不飽和脂肪酸がォレイン酸であることを特徴とする請求の範囲第 1項に記 載の銅微粒子。  2. The copper fine particles according to claim 1, wherein the unsaturated fatty acid is oleic acid.
3 .  3.
疎水特性を示すことを特徴とする請求の範囲第 1又は 2項に記載の銅微粒子。 3. The copper fine particles according to claim 1 or 2, which exhibit hydrophobic properties.
4 . Four .
銅イオンを含む不飽和脂肪酸溶液とアルドース （還元性単糖類） 溶液を混合し てェマルジョンを形成する 1次還元工程と、 該ェマルジョンにァスコルビン酸水 溶液を加える 2次還元工程と、 銅微粒子分離工程とを有する銅微粒子製造方法。  A primary reduction step of forming an emulsion by mixing an unsaturated fatty acid solution containing copper ions and an aldose (reducing monosaccharide) solution, a secondary reduction step of adding an ascorbic acid aqueous solution to the emulsion, and a copper fine particle separation step A method for producing copper fine particles.
5 . Five .
前記不飽和脂肪酸がォレイン酸であることを特徴とする請求の範囲第 4項に記 載の銅微粒子製造方法。  5. The method for producing copper fine particles according to claim 4, wherein the unsaturated fatty acid is oleic acid.
6 .  6.
前記アルドース （還元性単糖類） がグルコースであることを特徴とする請求の 範囲第 4又は 5項に記載の銅微粒子製造方法。  6. The method for producing copper fine particles according to claim 4, wherein the aldose (reducing monosaccharide) is glucose.
7 .  7.
銅イオンとォレイン酸の重量比が 4 . 3 w t %以下であることを特徴とする請 求の範囲第 5又は 6項に記載の銅微粒子製造方法。  7. The method for producing copper fine particles according to claim 5 or 6, wherein the weight ratio of copper ion to oleic acid is 4.3 wt% or less.
8 .  8.
ポリマーマ ト リ ックス中に、 平均粒径が 1 0 0 n m以下であり、 表面の一部又 は全部が不飽和脂肪酸のカルボキシル末端基で修飾された銅微粒子が分散されて いることを特徴とする絶縁材料。  In the polymer matrix, the average particle size is 100 nm or less, and a part or all of the surface is dispersed with copper fine particles modified with carboxyl end groups of unsaturated fatty acids. Insulating material.
9 .  9.
前記不飽和脂肪酸がォレイン酸であることを特徴とする請求の範囲第 8項に記 載の絶縁材料。 The unsaturated fatty acid according to claim 8, wherein the unsaturated fatty acid is oleic acid. Insulation material listed.
1 0 .  Ten .
回路基板内の配線溝、 ビアホール、 コンタク トホール及び貫通孔から選ばれる 凹部又は孔に、 平均粒径が 1 0 0 n m以下であり、 表面の一部又は全部が不飽和 脂肪酸のカルボキシル末端基で修飾された銅微粒子が充填されていることを特徴 とする配線構造。 前記不飽和脂肪酸がォレイン酸であることを特徴とする請求の範囲第 1 0項に 記載の配線構造。  In the recesses or holes selected from wiring grooves, via holes, contact holes and through holes in the circuit board, the average particle size is 100 nm or less, and part or all of the surface is modified with carboxyl end groups of unsaturated fatty acids A wiring structure characterized by being filled with fine copper particles. The wiring structure according to claim 10, wherein the unsaturated fatty acid is oleic acid.
1 2 . 1 2.
回路基板内の配線溝、 ビアホール、 コンタク トホール及び貫通孔から選ばれる 凹部又は孔に、 銅イオンを含む不飽和脂肪酸溶液とグルコース溶液を混合してェ マルジョンを形成する 1次還元工程と、 該ェマルジョンにァスコルビン酸水溶液 を加える 2次還元工程と、 銅微粒子分離工程により製造された銅微粒子を充填す ることを特徴とする配線回路板の製造方法。 - A primary reduction step of forming an emulsion by mixing an unsaturated fatty acid solution containing copper ions and a glucose solution in a recess or hole selected from a wiring groove, a via hole, a contact hole and a through hole in the circuit board; and the emulsion A method for producing a printed circuit board comprising filling a copper fine particle produced by a secondary reduction step of adding an ascorbic acid aqueous solution to the copper fine particle separation step. -
1 3 . 13 .
前記不飽和脂肪酸がォレイン酸であることを特徴とする請求の範囲第 1 2項に 記載の配線回路板の製造方法。  13. The method for manufacturing a printed circuit board according to claim 12, wherein the unsaturated fatty acid is oleic acid.
1 4 .  14 .
回路基板内の配線溝、 ビアホール、 コンタク トホール及び貫通孔から選ばれる 少なくとも一つの凹部又は孔への、 銅微粒子の充填方法が、 スクリーン印刷法、 デイスペンス法、 インクジヱット法又はスピンコート法である請求の範囲第 1 2 又は 1 3項に記載の配線回路板の製造方法。  The method for filling copper fine particles into at least one recess or hole selected from wiring grooves, via holes, contact holes and through holes in a circuit board is a screen printing method, a dispense method, an ink jet method or a spin coating method. A method for manufacturing a printed circuit board according to the items 1 2 or 1 3 of the range.
1 5 ·  1 5
請求の範囲第 8又は 9項に記載の絶縁材料を有する電子 ·電気機器。  An electronic / electrical device comprising the insulating material according to claim 8 or 9.
1 6 .  1 6.
請求の範囲第 1 0又は 1 1項に記載の配線構造を有する電子 '電気機器。  An electronic device having the wiring structure according to claim 10 or 11.
PCT/JP2007/069785 2006-10-03 2007-10-03 Copper microparticle, method for production of copper microparticle, insulating material, wiring structure, method for production of wiring circuit board, and electronic/electric device WO2008041780A1 (en)

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