TWI785130B - Method for producing composite body composed of metal coated with solid fine particles, and composite body - Google Patents

Abstract

Provides a technology that can easily implement the aggregation of solid particles that is difficult to achieve in the conventional technology, and also makes it easy to form patterns.

A method for producing a composite body containing metal coated with solid microparticles, which includes irradiating ultrashort pulse laser light to a solution containing metal ions, colloids, and/or complexes to precipitate metals and disperse them in The step of coating the precipitated metal with the solid particles composed of metal oxide particles, non-metal oxide particles, or ceramic particles in the solution.

Description

Method for producing composite body composed of metal coated with solid fine particles, and composite body

The present invention relates to a very short time span of ultrashort pulse laser light, and utilizes nonlinear optical absorption of metal ions, colloids, complexes (hereinafter referred to as "metal ions, etc.") derived from ultrashort pulses , and the metal is precipitated at the spot where the ultra-short pulse laser light is concentrated, and a very large energy is given to the precipitated metal in an instant before the thermal effect occurs, thereby covering the precipitated metal as a compound formed by the aggregation of solid particles with various functions. Body manufacturing method. Also, the present invention relates to a highly transparent coating film-forming material, a solid electrolyte fuel cell electrolyte material, a light-emitting diode or a light-responsive semiconductor material, a resistive film-forming material, and a metal magnetic powder even if it does not have photosensitivity. Solid particles of functional materials such as materials, superconducting materials, piezoelectric ceramic thick film materials, dielectric film materials, and particle-bonded materials, etc., and a method of forming a pattern by moving the focused position of ultrashort pulse laser light .

In recent years, attempts have been made to perform various coatings by collision of fine particles in a dry method. This technology converts the kinetic energy of microparticles into thermal energy in both time and space through collision, so that the material becomes high temperature (above the melting point) and particles combine to form a coating.

As an example of the coating method by the collision of fine particles, first, a method using an electric field is mentioned. Specifically, there are electrostatic particle impact coating (EPID) method (a method of embedding raw material particles in a substrate using a substrate material having a hardness lower than that of the raw material particles), cluster ion beam method, and the like. In addition, there is also a method (gas deposition (GD) method) in which gas is transported. According to this method, a metal nanocrystal film can be formed at room temperature. Furthermore, the film density of the film formed by this method can be considered to be about 55-80% of the theoretical density. To obtain bulk-level electrical conduction, it is necessary to grow by thermal crystallization. Furthermore, an aerosol deposition (AD) method is attracting attention (patent document 1). According to this method, a dense and high-hardness film containing metal and ceramic material can be produced at room temperature. In addition, it is also reported that fine patterns can be obtained without etching, but it is difficult to handle the fine powder system in the working environment. These methods all require large-scale installations.

On the other hand, as the laser used for laser light irradiation, the ultrashort pulse laser can be considered to use its very short time span, and has the characteristic of giving a very large energy to the material instantaneously before the thermal effect occurs. For example, in Non-Patent Document 1, an example of ultrashort pulse laser processing is reported. By this, when copper is used as a target and irradiated with 10 ps (picosecond) pulse laser, it is estimated that the surface electron temperature reaches several thousand degrees Celsius. On the one hand, the thermal diffusion length is not more than μm.

Therefore, it is reported that a silver ion solution is irradiated with ultrashort pulse laser light to reduce metal ions in the solution and precipitate silver.

For example, in Non-Patent Document 2, it is reported that silver dots are obtained by reducing silver ions by irradiation with a high-intensity laser beam with a wavelength of 800 nm, a pulse width of 80 fs, a frequency of 82 MHz, and an output of 14.97 mW.

In addition, in Non-Patent Document 3, it is reported that by using a near-infrared light source with a wavelength of 1064nm, and a relatively weak continuous oscillation pulsed laser with a visible light source with a wavelength of 532nm or 633nm, the reduction reaction of silver nitrate is used to form silver on the glass substrate. Patterning of aggregates of rice particles.

In order to carry out the patterning of materials caused by such laser light irradiation, it is necessary for the processed material to have suitable light absorption characteristics for laser light. For example, when Ag ink is irradiated with laser light to form a metal (Ag) pattern, it is a prerequisite for the ink to absorb laser light appropriately.

When ultra-short pulse light is condensed inside the highly transparent glass at the laser oscillation wavelength, only the vicinity of the condensed point can be directly processed. Non-Patent Document 4 reports an example of processing transparent materials with femtosecond lasers. It reports that irradiating silica glass with pulsed light with a wavelength of 800 nm and a pulse width of 120 fs induces lattice defects at the light-concentrating points inside the glass, and resulting in high density. However, in this method, it is difficult to collect light on the solid fine particles dispersed in the solution, and even if it is realized, the material properties of the irradiated part will be modified, so that the physical properties of the solid fine particles will not be avoided. The inventors of the present invention have arrived at the present invention as a result of investigating a method of gathering materials that do not originally have absorption using ultrashort pulse lasers, using nonlinear optical absorption derived from ultrashort pulses. [Prior Art Literature] [Patent Document]

[Patent Document 1] Japanese Patent Laid-Open No. 2003-112976 [Non-patent literature]

[Non-Patent Document 1] S.I. Anisimov and B. Rethfeld, Proc. SPIE Nonresonant Laser-Matter Interaction (NLMI-9), 3093, 192 (1997) [Non-Patent Document 2] A. Ishikawa, T. Tanaka, and S. Kawata, Apply.Phys.Lett.89, 113102 (2006) [Non-Patent Document 3] FY2019 General Research and Development Grant AF-2009216, Hiroyuki Yoshikawa, Assistant Professor, Department of Precision Science and Applied Physics, Graduate School of Engineering, Osaka University [Non-Patent Document 4] K. Miura, Jianrong Qiu, H. Inouye, and T. Mitsuyu, Apply.Phys.Lett.71, 3329(1997)

[Problem to be Solved by the Invention]

The present invention is to provide a technology that can easily implement the aggregation of solid fine particles that is difficult to achieve in the prior art, and make pattern formation easy. [Means to solve the problem]

The inventors of the present invention, based on the knowledge that metal particles can be precipitated by using ultrashort pulse laser by utilizing nonlinear optical absorption derived from ultrashort pulses, and by imagining the use of the metal particles as a tiny heat source, aimed at the original non-existent The present invention is achieved as a result of in-depth research on the aggregation method of materials that absorb laser light. In order to solve the above-mentioned problems, the inventors of the present invention disperse solid particles of non-photosensitive materials and the like in a solution containing metal ions, etc., and irradiate ultrashort pulse lasers to aggregate solid particles. Composites formed on metal surfaces become possible. The ultra-short pulse laser can instantly release high-intensity light pulses from its short pulse width. The nonlinear optical absorption generated by the high-intensity pulses can directly process only the vicinity of the focus point. Using this characteristic, the metal is deposited only near the spot of the ultrashort pulse laser in the solution, and the precipitated metal is further heated locally, so that the surrounding solid particles are gathered on the metal surface. By this method, it is possible to pattern non-photosensitive materials. According to the present invention, even high-transparency coating film forming materials without photosensitivity, solid electrolyte fuel cell electrolyte materials, light-emitting diodes or light-responsive semiconductor materials, resistive film forming materials, and metal magnetic powder materials Solid particles of functional materials such as superconducting materials, piezoelectric ceramic thick film materials, dielectric film materials, and particle-bonded materials can also be patterned by moving the focused position of ultrashort pulse laser light.

That is, the present invention is a method for producing a composite body containing metals coated with solid fine particles, which includes irradiating ultrashort pulse laser light to a solution containing metal ions, colloids, and/or complexes, so that Metal precipitation, the step of coating the precipitated metal with solid microparticles composed of metal oxide particles, non-metal oxide particles, or ceramic particles dispersed in the aforementioned solution.

The aforementioned metals are not particularly limited as long as the precipitated metal does not chemically react with the solvent. When water is selected as the solvent, it is preferably a metal selected from the group consisting of silver, copper, nickel, lead, tin, platinum, and gold that does not react with water and high-temperature water vapor.

The melting point of the aforementioned solid fine particles is preferably 500°C to 3500°C. Also, the aforementioned solid fine particles preferably have a diameter of 0.005 μm to 1 μm. Furthermore, the concentration of the aforementioned solid fine particles in the aforementioned solution is preferably 0.01% by mass to 3.0% by mass.

The wavelength of the aforementioned ultrashort pulse laser light is preferably 200 nm to 2000 nm. In addition, the energy density (energy input per unit area) of the aforementioned ultrashort pulse laser light is preferably 0.01mJ/cm ² -10mJ/cm ² . Further, the repetition frequency of the aforementioned ultrashort pulse laser light is preferably 1 Hz-500 MHz. The average output of the aforementioned ultrashort pulse laser light is preferably 10 mW or more. In addition, the focusing diameter of the aforementioned ultrashort pulse laser light is preferably 20 μm or less.

The present invention may further include a step of immersing the substrate in the aforementioned solution, and a step of moving the beam spot of the aforementioned ultrashort pulse laser light along the surface of the aforementioned substrate. Alternatively, the present invention may further include a step of immersing the substrate in the aforementioned solution, and a step of moving the beam spot of the aforementioned ultrashort pulse laser light from the surface of the aforementioned substrate to a specific position in the aforementioned solution away from the aforementioned substrate. The present invention is further a composite, which is a composite containing a metal coated with solid microparticles, wherein the aforementioned metal exists in a solution as metal ions, colloids, and/or complexes, and the solution can be For those precipitated by irradiation with ultrashort pulse laser light, the solid fine particles are metal oxide particles, non-metal oxide particles, or ceramic particles, the metal forms a core, and the core has a cavity inside. The aforementioned metals are preferably selected from the group consisting of silver, copper, nickel, lead, tin, platinum and gold. In addition, the melting point of the solid fine particles is preferably 500°C to 3500°C. Furthermore, the aforementioned solid particles preferably have a diameter of 0.005 μm˜1 μm. [Effect of Invention]

Electrostatic particle impingement coating (EPID) method, cluster ion beam method, aerosol deposition (AD) method and other film formation methods using solid particles in the past, there are many processes and the prevention of fine powders with low bulk density There are many problems such as large-scale equipment for scattering, countermeasures for health or safety, and large loss of raw materials due to direct use of powder. However, according to the present invention, these problems of conventional technologies can be solved.

Also, according to the present invention, the metal is dissolved in the state of metal ions or metal complexes in advance in the liquid in which solid fine particles (silicon dioxide, aluminum oxide, titanium oxide particles, etc.) are dispersed in the solvent, and the The solution is irradiated with ultrashort pulse laser light, and the solid particles dispersed in the solution can be easily coated on the metal surface, and a composite containing metal covered by solid particles can be produced. At this time, by controlling the irradiation of ultrashort pulse laser light It is expected that the present invention can be applied to various occasions by freely forming patterns on solid fine particles having various functions such as metal oxides, non-metal oxides, or ceramics, and manufacturing devices.

Further, by continuously carrying out the manufacturing method of the complex of the present invention on the substrate or in a direction perpendicular to the substrate, it is possible to form on the substrate a non-photosensitive compound that is difficult to pattern by laser light irradiation in the past. A three-dimensional pattern made of metal coated with a non-volatile material. At this time, since the present invention is based on a low-temperature optical process of irradiating ultrashort pulse laser light in a solution, patterning can be performed without causing major damage to the plastic substrate or components on the substrate.

Hereinafter, the form for carrying out this invention is demonstrated. The present invention is a method for producing a composite body containing metal coated with solid microparticles, which includes irradiating ultrashort pulse laser light to a solution containing metal ions, colloids, and/or complexes to precipitate metals, The step of coating the precipitated metal with solid fine particles composed of metal oxide particles, non-metal oxide particles, or ceramic particles dispersed in the aforementioned solution.

Referring to Fig. 1 showing a conceptual sectional view of an embodiment of the present invention, in the present invention, at first, in a solution container (holder), accommodating a solution in which silver nitrate is dissolved and solid microparticles are dispersed, on which a mine is placed. The substrate through which the light is transmitted is brought into contact with the solution on one side of the substrate. Next, from the other side of the substrate, the solution is irradiated with ultrashort pulse laser light to precipitate silver in the solution, and the precipitated silver is coated with solid fine particles dispersed in the solution to manufacture a silver coated with solid fine particles. Complex.

Referring to Fig. 2 which is a conceptual cross-sectional view showing the principle of the present invention, it can be considered that by irradiating the silver nitrate solution with ultrashort pulse laser light, metal (silver) is deposited on the substrate surface (solution side), the metal becomes the core, and the metal surface is covered. Locally heated, after the violent expansion caused by the vaporization of the solvent on the metal surface, through the phenomenon of violent shrinkage caused by decompression, the solid particles dispersed in the solution around the core are subjected to the force of violent contraction, so that It collides with the metal surface at high speed, thereby agglomerating dense aggregates on the metal surface, and forming a composite body containing metal coated with solid particles, but is not bound by any theory.

＜Metal＞ The metal used in the present invention exists as metal ions, colloids, and/or complexes in the solution irradiated with ultrashort pulse laser light. Also, as long as the deposited metal does not chemically react with the solvent, the type of the metal is not particularly limited. The metal used in the present invention, especially when water is selected as the solvent, is preferably selected from the group consisting of silver, copper, nickel, lead, tin, platinum and gold, and does not react with water and high-temperature water vapor . Even in the case of metals that react with water or high-temperature water vapor (for example, metals with high ionization tendency such as potassium, magnesium, aluminum, zinc, and iron), suitable metals can be selected by appropriately selecting a solvent.

When the metal exists as ions in the solution, the metal ions can be, for example, Ag ⁺ , Cu ⁺ , Cu ²⁺ , Ni ²⁺ , Sn ²⁺ , Sn ³⁺ , Sn ⁴⁺ , Pb ²⁺ , Pt ²⁺ , Au ⁺ , Au ³⁺ etc. The counter ion of the metal salt is preferably selected from the group consisting of nitrate ions, sulfate ions, carboxylate ions, cyanide ions, sulfonate ions, borate ions, halogen ions, carbonate ions, phosphate ions and perchlorate ions.

Examples of metals present as colloids in a solution include silver colloids, copper colloids, and nickel colloids. When a metal exists as a complex in a solution, for example, the case where a ligand is coordinated to a metal atom makes it easy to disperse and dissolve in a solvent. Examples of silver complexes include silver behenate, silver chloro[1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene], silver pyridine-2-carboxylate (II), silver sulfadiazine, etc. Also, copper complexes include copper(I) acetate, bis(1,3-propylenediamine)copper(II) dichloride, copper(II) acetylacetonate, bis(8-quinoline)copper(II) II) etc. Examples of gold complexes include tetrachloroaurate (III) acid tetrahydrate, (dimethyl sulfide) gold (I) chloride, chloro[1,3-bis(2,6-diisopropyl phenyl) imidazol-2-ylidene] gold (I) and so on. Lead complexes include lead tetraacetate, lead(II) acetate, and the like. Furthermore, it can be products containing metal complexes such as silver nano ink and copper nano ink.

The concentration of the metal used in the present invention in the solution is not particularly limited. It is not limited as long as it can be dissolved or dispersed uniformly at 0.1% by mass or more. When the dilute solution is less than 0.1% by mass, even if there is aggregation of solid particles, the light efficiency will also deteriorate. When the metal concentration in the solution is made high, the size of the metal core formed by irradiating ultrashort pulse laser light increases. The concentration of the metal in the solution is preferably 3.0% by mass or less.

＜Solid particles＞ The solid microparticles used in the present invention are metal oxide particles, non-metal oxide particles, or ceramic particles dispersed in a solution irradiated with ultrashort pulse laser light. The dispersion referred to here does not necessarily mean that the solid fine particles are uniformly distributed throughout the solution, and a part of the solid fine particles may be precipitated as long as the solid fine particles exist near the light-gathering point. As the solid fine particles used in the present invention, for example, inorganic compounds such as carbides, nitrides, and borides can be used. In addition, high transparency coating film forming materials, solid electrolyte fuel cell electrolyte materials, light emitting diodes or photoresponsive semiconductor materials, resistor film forming materials, metal magnetic powder materials, superconducting materials, Solid fine particles of functional materials such as piezoelectric ceramic thick film materials, dielectric film materials, and fine particle bonded materials.

These solid fine particles may be dispersed in a solvent in plural of different kinds at the same time, or solid fine particles obtained by bonding solid fine particles to each other, or solid fine particles composed of plural components may be used. Further, solid fine particles such as gold-carrying titanium oxide (Au/TiO ₂ ) can also be used together with the solid fine particles.

The melting point of the aforementioned solid fine particles is preferably 500°C to 3500°C. For example, when silver is used as the metal and titanium oxide is used as the solid fine particles, a cross section like that shown in FIG. 4 is observed. The interface system between titanium oxide and silver is widely in contact, while there are voids inside the silver. Since the ratio of the cross-sectional area of the cavity to the cross-sectional area of silver is determined to be about 5 to 1, the coefficient of linear expansion of titanium oxide (average from room temperature to 1000°C) is 8×10 ^-6 (1/K), and that of silver The coefficient of linear expansion is 25×10 ^-6 (1/K), so it is speculated that by irradiating ultrashort pulse laser light, the highest temperature reached on the silver surface is about 5000K (above 4700°C). Therefore, solid fine particles having a melting point of 3500° C. or lower are considered to melt and easily gather on the metal surface.

There are solid fine particles used as coating materials, and solid fine particles of oxides include, for example, silicon dioxide (1650°C), tin oxide (1080°C), iron oxide (1565°C), chromium oxide (2435°C) , beryllium oxide (2570°C), hafnium oxide (2758°C), (reaction with water), manganese trioxide (1080°C), trimanganese tetraoxide (1567°C), manganese oxide (1650°C), barium oxide (1920°C ℃), strontium oxide (2531℃), ferric oxide (1538℃), cobalt oxide (1933℃), nickel oxide (1984℃), lead zirconate titanate (1400℃), lithium titanate (1520℃) , aluminum titanate (1860°C), strontium titanate (2080°C), lead titanate, lead zirconate, mixed crystal of lead titanate and lead zirconate (lead zirconate titanate), scandium oxide (1000°C), Neodymium oxide (2270°C), gadolinium oxide (2330°C), samarium oxide (2300°C), yttrium oxide (2410°C), nickel oxide (600°C), tricobalt tetroxide (895°C), indium tin oxide (1800°C), oxide Magnesium (2852°C), Zirconia (2715°C), Cordierite (1450°C), Anorthite (1553°C), Anorthite (1593°C), Calcium Aluminate (1600°C), Lithium Aluminate (1625°C) , strontium aluminate (1790°C), mullite (1850°C), yttrium aluminate (1970°C), spinel (2130°C), neodymium oxide (1900°C), scandium oxide (2485°C), lanthanum gallate oxides, PbZrTi oxides, LaSrCo oxides, LaSrMn oxides, YBa oxides, BiSrCa oxides, TlBaCa oxides, ferrite mainly composed of iron oxide, other than the above Oxide ceramics, etc. (The temperature in brackets is the melting point. The same below).

Also, in terms of carbide compounds, chromium carbide (1890°C), boron carbide (2763°C), vanadium carbide (2840°C), tungsten carbide (2870°C), molybdenum carbide (2687°C), titanium carbide (3170°C ), zirconium carbide (3500°C), niobium carbide (3500°C), tantalum carbide (3880°C), silicon carbide (2730°C), bismuth titanate (1203°C), etc. In terms of nitride compounds, examples include niobium nitride (2573°C), titanium nitride (2930°C), tantalum nitride (3090°C), indium nitride (1100°C), gallium nitride (2500°C), nitrogen Indium nitride (1100°C), gallium nitride (2500°C), boron nitride (2967°C), aluminum nitride (2200°C), etc. In terms of boron compounds, boron (2076°C), aluminum boride (1655°C), chromium boride (2373°C), titanium boride (2400°C), molybdenum boride (2543°C), tungsten boride ( 2643°C), vanadium boride (2673°C), zirconium boride (3100°C), magnesium boride (800°C), niobium boride (3000°C), tantalum boride (3037°C), etc. Furthermore, examples of halogen compounds include cerium fluoride (1800°C), etc., examples of phosphoric acid compounds include hydroxyapatite (1650°C), and examples of lithium-based compounds include Li ₂ SP ₂ S ₅ , LiCoO ₂ , xLi ₂ O-BPO ₄ (0.5≦x≦1.5), and the like, and examples of compound semiconductors include semiconductors using Group II elements and Group VI elements.

In particular, solid fine particles used as materials for forming coating films with high transparency include nickel oxide, tricobalt tetroxide, indium tin oxide, magnesium oxide, zirconium oxide, aluminum nitride, magnesium boride, silicon nitride, Silicon carbide, cerium fluoride, etc.

For solid fine particles used as electrolyte materials for solid electrolyte fuel cells, scandium oxide, neodymium oxide, gadolinium oxide, samarium oxide (2300°C), yttrium oxide, neodymium oxide, scandium oxide, LiCoO ₂ , lithium sulfide series compounds etc. Specific examples of lithium sulfide compounds include Li ₂ SP ₂ S ₅ , Li ₂ SP ₂ S ₅ -LiI, Li ₂ SP ₂ S ₅ -LiCl, Li ₂ SP ₂ S ₅ -LiBr, Li ₂ SP ₂ S ₅ -Li ₂ O, Li ₂ SP ₂ S ₅ -Li ₂ O-LiI, Li ₂ S-SiS ₂ , Li ₂ S-SiS ₂ -LiI, Li ₂ S-SiS ₂ -LiBr, Li ₂ S-SiS ₂ - LiCl, Li ₂ S-SiS ₂ -B ₂ S ₃ -LiI, Li ₂ S-SiS ₂ -P ₂ S ₅ -LiI, Li ₂ SB ₂ S ₃ , Li ₂ SP ₂ S ₅ -ZmSn (only, m, n is a positive number. Z is any one of Ge, Zn, and Ga), Li ₂ S-GeS ₂ , Li ₂ S-SiS ₂ -Li ₃ PO ₄ , Li ₂ S-SiS ₂ -Li _x MO _y (only, x, y are positive numbers. M is any one of P, Si, Ge, B, Al, Ga, In), Li ₁₀ GeP ₂ S ₁₂ , xLi ₂ O-BPO ₄ (0.5≦x≦1.5), Li _x B _1-x/3 PO ₄ (0.75≦x<3), etc.

As for solid microparticles used as light-emitting diodes or light-responsive semiconductor materials, examples include indium nitride, gallium nitride, aluminum nitride, semiconductors using group II elements and group VI elements, and the like. Specific examples of semiconductors using group II elements and group VI elements include CuInSe ₂ , CuInS ₂ (CIS), CuIn _1-x Ga _x Se ₂ (CIGS), Cu ₂ ZnSnS ₄ (CZTS), and CdTe-based semiconductors.

Examples of solid fine particles used as a material for forming a resistor film include triiron tetroxide, cobalt oxide, nickel oxide, rhenium oxide, iridium oxide, ruthenium oxide, ferrite, and oxide ceramics. Specific examples of oxide ceramics include SrVO ₃ , CaVO ₃ , LaTiO ₃ , SrMoO ₃ , CaMoO ₃ , SrCrO ₃ , CaCrO ₃ , LaVO ₃ , GdVO ₃ , SrMnO ₃ , CaMnO ₃ , NiCrO ₃ , BiCrO ₃ , LaCrO ₃ , LnCrO ₃ , SrRuO ₃ , CaRuO ₃ , SrFeO ₃ , BaRuO ₃ , LaMnO ₃ , LnMnO ₃ , LaFeO ₃ , LnFeO ₃ , LaCoO ₃ , LaRhO ₃ , LaNiO ₃ , PbRuO ₃ , Bi ₂ Ru ₂ O ₇ , LaTaO ₃ , BiRuO ₃ , LaB ₆ , etc.

Examples of solid fine particles used as superconducting materials include YBa-based oxides, BiSrCa-based oxides, and TlBaCa-based oxides. Examples of solid fine particles used as piezoelectric ceramic thick film materials include magnesium oxide, manganese trioxide, trimanganese tetraoxide, manganese oxide, barium oxide, strontium oxide, barium titanate, and hydroxyapatite.

Examples of solid fine particles used as dielectric film materials include titanium oxide, silicon dioxide, aluminum nitride, magnesium oxide, barium titanate, lead zirconate titanate, and oxide ceramics. Specific examples of _oxide ceramics include PZT, _{(Pb 1-y La y ) ( Zr} PLZT, Pb(Mg _1/3 Nb _2/3 )O ₃ , Pb(Ni _1/3 Nb _2/3 )O represented by the general formula of _1-x Ti _x )O ₃ (0≦x, y≦1) _3. Pb(Zn _1/3 Nb _2/3 )O ₃ , BaTiO ₃ , BaTi ₄ O ₉ , Ba ₂ Ti ₉ O ₂₀ , Ba(Zn _1/3 Ta _2/3 )O ₃ , Ba(Zn _{1/3 3} Nb _2/3 )O ₃ , Ba(Mg _1/3 Ta _2/3 )O ₃ , Ba(Mg _1/3 Ta _2/3 )O ₃ , Ba(Co _1/3 Ta _2/3 )O ₃ , Ba(Co _1/3 Nb _2/3 )O ₃ , Ba(Ni _1/3 Ta _2/3 )O ₃ , Ba(Zr _1-x Ti _x )O ₃ , (Ba _1-x Sr _x )TiO _3. ZrSnTiO ₄ , CaTiO ₃ , MgTiO ₃ , SrTiO ₃ , etc.

There are solid microparticles used as microparticle binding materials, such as cordierite, anorthite, calcium feldspar, calcium aluminate, lithium aluminate, strontium aluminate, mullite, yttrium aluminate, spinel, aluminum nitride Wait.

In the present invention, there are roughly two methods for irradiating ultrashort pulse laser light. One is a method of irradiating through a transparent substrate on which a metal is deposited, and the other is a method of irradiating the surface of a substrate through a solution. The former case does not pass through the solution, so it is not easily affected by the solid particles dispersed in the solution. In the latter case, it can be considered that if the light absorption caused by the solid microparticles in the solution is small, then light loss or scattering is suppressed, more solid microparticles can be dispersed in the solvent, and the precipitated metal can be efficiently removed. Absorbing laser light is not a problem, but on the contrary, if the light absorption is large, light loss or scattering will easily occur. In this case, it can be controlled by changing the particle diameter of solid particles or making the concentration in the solution low. The irradiation of laser light on the precipitated metal becomes effective.

<Solvent> The solvent used for the solution used in the present invention is not particularly limited as long as it is suitable for dispersing solid fine particles. Solid fine particles dispersed in organic solvents such as toluene can be dispersed in a mixed solvent of alcohol and water, etc. The solvent is selected according to the use. The viscosity of the solution used in the present invention is not particularly limited. When it is desired to make the coating of the solid fine particles covering the metal as the core thick, it is considered to increase the concentration of the solid fine particles. In this case, the viscosity of the solution increases.

＜Other ingredients＞ It may be contained in the solution as long as it does not dissolve in a dispersant used for dispersing solid fine particles or interfere with irradiation of laser light.

<Laser> In the present invention, "ultrashort pulse laser" refers to a laser with a few femtoseconds (1 femtosecond is 1×10 ^-15 seconds, also marked as fs) to hundreds of picoseconds (1 picosecond is 1 A pulsed laser with a pulse width of ×10 ^-12 seconds, also denoted as ps).

The average output of the ultrashort pulse laser light used in the present invention is preferably 10 mW or more. Also, the focusing diameter of the ultrashort pulse laser light is preferably 20 μm or less. By controlling the irradiation amount and intensity of the ultrashort pulse laser light, the size of the metal core formed can be controlled. Also, the repetition frequency of the ultrashort pulse laser light is preferably 1 Hz to 500 MHz.

The wavelength of the ultrashort pulse laser light used in the present invention is not particularly limited as long as it is a wavelength absorbed by the metal ions used in the present invention and has a high molar absorption coefficient. If the wavelength is less absorbed by solid fine particles, the production efficiency of the complex of the present invention will be better, which is preferable. Specifically, the wavelength of the ultrashort pulse laser light used in the present invention is matched with the absorption wavelength of the photosensitive metal compound dissolved in the solution. For example, the molar absorption coefficient of the metal used in the present invention is 5 l/mol ･It is preferable to select a form of cm or more, but it is not particularly limited thereto. The wavelength of the ultrashort pulse laser light is preferably 200nm-2000nm. Furthermore, the energy density of the ultrashort pulse laser light (energy input per unit area) is preferably 0.01mJ/cm ² -10mJ/cm ² .

The present invention may further include a step of immersing the substrate in the solution, and a step of moving the beam spot of the ultrashort pulse laser light along the surface of the substrate. Referring to Fig. 3, which is a conceptual cross-sectional view showing another embodiment of the present invention, one side of the substrate is immersed in the solution, and by moving the substrate in the scanning direction in this state, the beam spot of the ultrashort pulse laser light can be moved along the surface of the substrate. move. The metal is precipitated in the solution by ultrashort pulse laser irradiation, and only occurs near the laser focusing point through nonlinear optical absorption. Therefore, in the present invention, a three-dimensional metal structure covered with solid microparticles can be produced by arranging a laser focus at any position in the solution away from the substrate, not just on the surface of the substrate, and performing three-dimensional scanning. That is, the present invention may further include a step of immersing the substrate in the solution, and a step of moving the beam spot of the ultrashort pulse laser light from the surface of the substrate to a specific position in the solution away from the substrate. In addition, the three-dimensional structure made of solid fine particles can also be taken out by removing the metal core from the manufactured composite by etching or the like.

＜Post-processing＞ The structure can be stabilized by heat-treating the complex produced by the production method of the present invention in an electric furnace, carbon dioxide gas laser irradiation, or the like. Also, only the covered part can be taken out by removing the metal core part from the manufactured composite by etching or the like. [Example]

The following examples illustrate the present invention in more detail, but the present invention is not limited thereto.

(Example 1) Put 6ml of pure water and 10ml of ethanol into a brown bottle, put 4ml of silver nitrate solution (1mol/l, Junzheng Chemical Co., Ltd.), and stir. Thereafter, 0.7 ml of a silica nanoparticle dispersion solution (Sigma-aldrich, LUDOX, TM-50, nanoparticle diameter 22 nm, concentration 50% by mass) was added, and stirred for another hour. The concentration of silicon dioxide at this time was 2.5% by mass. The solution was transferred from the brown bottle to a solution container made of Teflon (registered trademark), and the container was covered with a cover glass serving as a substrate, so that one side of the substrate was in direct contact with the solution in the container. Next, use a femtosecond laser (C-Fiber780, MenloSystems Ltd.) to adjust the focus to the contact surface between the substrate and the solution, with a center wavelength of 780nm, a repetition rate of 100MHz, a pulse width of 127fs, an average laser output of 20mW, and a focal diameter (Theoretical value) Conditional irradiation of 2 μm and energy density of 6.4 mJ/cm ² . By moving the container horizontally at a scanning speed of 10 μm/s, composites were continuously formed on the surface of the substrate along the scanning direction. Cover the formed complex with a carbon protective film, cut out slices with a focused ion beam, and observe the cross-sectional shape of the formed complex with a microscope (Figure 4). A core of silver with a diameter of about 2.5 μm in a semicircle and a coating of silicon dioxide nanoparticles covering it with a thickness of about 2.5 μm were confirmed.

(Example 2) Except in Example 1, 1.9ml of titanium oxide nanoparticle dispersion aqueous solution (NTB-1, Showa Denko Co., Ltd., nanoparticle diameter 10-20nm (catalogue value), concentration 15% by mass) was used instead of The dispersion of the solution and the irradiation of laser light were carried out under the same conditions as in Example 1 except for the aqueous solution of silica nanoparticles dispersion. The concentration of titanium oxide at this time was 1.5% by mass. When the cross-sectional shape of the formed composite was observed with a microscope, a silver core with a semicircular diameter of about 5 μm and a coating of titanium oxide nanoparticles with a thickness of about 5 μm covering it were confirmed ( FIG. 5 ).

(Embodiments 3-7) In Example 1, various types of solid microparticles shown in Table 1 were used instead of silica nanoparticles, and the dispersion of the solution and laser irradiation were performed under the same conditions as in Example 1. In all Examples, complex formation was confirmed in the same manner as in Example 1.

(Embodiment 8) Except that the scanning speed of the container was 30 μm/s, the concentration of titanium oxide was 1.5% by mass, and the average laser output was changed to 15mW, 25mW, and 30mW, the solution dispersion and laser light irradiation were carried out under the same conditions as in Example 2. . The cross-section of the obtained complex was observed with a microscope, and the relationship between the cross-sectional area of the titanium oxide film and the average laser output is shown in FIG. 6 . It can be seen from Fig. 6 that as the laser output increases, a composite with a large cross-sectional area can be obtained.

(Embodiments 9-12) In Example 6, the average laser output was fixed at 25mW, and the concentration of titanium oxide, which was originally 1.5% by mass, was reduced to 0.8% by mass (Example 9), 0.3% by mass (Example 10), and 0.2% by mass (Example 10). Example 11), 0.01% by mass (Example 12), dispersion of the solution and laser light irradiation were performed in the same manner as in Example 6. The cross section of the obtained composite was observed with a microscope. The relationship between the cross-sectional area of the titanium oxide film and the concentration of titanium oxide is shown in FIG. 7 . As can be seen from FIG. 7 , the cross-sectional area changes when the titanium oxide concentration is changed, but if the concentration is 0.1% by mass or more, a good composite can be obtained even at a low titanium oxide concentration.

(Examples 13-15) Dispersion of the solution and irradiation of laser light were performed under the same conditions as in Example 2, except that the titanium oxide concentration was 1.5% by mass and the nanoparticle size was made larger. As a result of microscopic observation of the cross-sections of the complexes obtained when the particle size of the nanoparticles was 0.1 μm (Example 13), 0.5 μm (Example 14), and 1.0 μm (Example 15), it was confirmed that any of them were formed. Good composite with coating. (Example 16-19) Silver nitrate solution (1mol/l) 4ml of embodiment 1 is replaced by copper sulfate (embodiment 16), tetrachloroauric (III) acid tetrahydrate (embodiment 17), nickel sulfate (embodiment 18), lead nitrate (II) 4ml of each aqueous solution (1mol/l) of (Example 19) was stirred together with 6ml of pure water and 10ml of ethanol in a brown bottle. Afterwards, 0.7ml of silicon dioxide nanoparticle dispersion solution (Sigma-aldrich, LUDOX, TM-50, nanoparticle particle size 22nm, concentration 50% by mass) was placed, and stirred again for 1 hour, with the same method as in Example 1. Conditions, dispersion of the solution and laser light irradiation. The concentration of silicon dioxide at this time was 2.5% by mass. In all cases of Examples 16 to 19, the aggregation of silica fine particles was confirmed, and it was also confirmed in cross-sectional microscopic observation that a good composite body with a coating layer was formed.

[ Fig. 1 ] A conceptual sectional view showing an embodiment of the present invention. [ Fig. 2 ] A conceptual sectional view showing the principle of the present invention. [ Fig. 3 ] A conceptual cross-sectional view showing another embodiment of the present invention. [ Fig. 4 ] Micrograph of a cross-section of the composite produced in Example 1. [ Fig. 5 ] Micrograph of a cross-section of the composite produced in Example 2. [ Fig. 6 ] A graph showing the relationship between the cross-sectional area of the coating and the average laser output. [ Fig. 7 ] A graph showing the relationship between the concentration of titanium oxide and the cross-sectional area of the film.

Claims (12)

A method for manufacturing a composite body composed of metals coated with solid microparticles, characterized in that the metal is precipitated by irradiating ultrashort pulse laser light to a solution containing metal ions, colloids, and/or complexes , the step of aggregating solid microparticles composed of metal oxide particles, non-metal oxide particles, or ceramic particles dispersed in the aforementioned solution, and coating the aforementioned precipitated metal, the energy density of the aforementioned ultrashort pulse laser light is: 0.01mJ/cm ² ~10mJ/cm ² , the aforementioned solid particles have a diameter of 0.005μm~1μm. The manufacturing method according to claim 1, wherein the aforementioned metal is selected from the group consisting of silver, copper, nickel, lead, tin, platinum and gold. The manufacturing method of claim 1 or claim 2, wherein the melting point of the aforementioned solid fine particles is 500°C to 3500°C. The manufacturing method of Claim 1 or Claim 2, wherein the concentration of the aforementioned solid fine particles in the aforementioned solution is 0.01% by mass to 3.0% by mass. The manufacturing method of claim 1 or claim 2, wherein the wavelength of the ultrashort pulse laser light is 200nm~2000nm. The manufacturing method of Claim 1 or Claim 2, wherein the repetition frequency of the aforementioned ultrashort pulse laser light is 1 Hz to 500 MHz. The manufacturing method according to claim 1 or claim 2, which further includes the step of dipping the substrate in the aforementioned solution, and the step of moving the beam spot of the aforementioned ultrashort pulse laser light along the surface of the aforementioned substrate. The manufacturing method according to claim 1 or claim 2, which further includes the step of immersing the substrate in the aforementioned solution, and moving the beam spot of the aforementioned ultrashort pulse laser light from the surface of the aforementioned substrate to the aforementioned solution away from the aforementioned substrate steps at a specific location. A composite body, which is a composite body composed of metal coated with solid particles, characterized in that the metal exists in a solution as metal ions, colloids, and/or complexes, which can be obtained by using the solution Those precipitated by irradiating ultrashort pulse laser light, the aforementioned solid fine particles are metal oxide particles, non-metallic oxide particles, or ceramic particles, the aforementioned solid fine particles have a diameter of 0.005 μm to 1 μm, the aforementioned metal forms the core, and the core There is a cavity inside it. As the complex of claim 9, wherein the aforementioned metal is selected from silver, Group of copper, nickel, lead, tin, platinum and gold. As in the composite of claim 9 or claim 10, wherein the melting point of the aforementioned solid particles is 500°C to 3500°C. The composite of claim 9 or claim 10, wherein the aforementioned solid particles have a diameter of 0.005 μm to 1 μm.

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