JP2008248267A - Method of manufacturing copper alloy fine particle and copper alloy fine particle obtained by the same method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a Cu-P alloy fine particle, a Cu-Sn alloy fine particle and a Cu-Sn-P alloy particle having suppressed dendrite formation by a reduction reaction in a liquid phase. <P>SOLUTION: The method of manufacturing the copper alloy fine particle is carried out (1) by depositing the alloy fine particle comprising copper-phosphorus by a reduction reaction in a reduction reaction solution containing cupric pyrophosphate, alkali metal pyrophosphate and/or alkaline earth metal pyrophosphate and a dispersant, (2) by depositing the alloy fine particle comprising copper-tin alloy by a reduction reaction in a reduction reaction solution containing cupric pyrophosphate, stannous pyrophosphate and a dispersant and (3) by depositing the alloy fine particle comprising copper-tin-phosphorus by a reduction reaction in a reduction reaction solution containing cupric pyrophosphate, stannous pyrophosphate, an alkali metal pyrophosphate and/or an alkaline earth metal pyrophosphate and a dispersant. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for producing alloy fine particles composed of copper-phosphorus, copper-tin, and copper-tin-phosphorous, and copper alloy fine particles obtained by the production method.

Nanometer-sized fine particles have a large specific surface area and have a function of gradually lowering the melting point as the particle size is reduced. These nanometer-sized fine particles are subjected to fine particle surface modification for compounding with resin, thin film technology / particle arrangement, and research and development for functional elements, depending on the type of particles, circuit wiring, interconnector, catalyst Application to battery electrodes, optical functional elements, visible light LED elements, and the like are also being studied.
As a vapor phase synthesis method of these fine particles, a thermal CVD method, a plasma CVD method, an electrostatic spray CVD method and the like are known (Patent Documents 1 and 2), and as a liquid phase synthesis method, a spray pyrolysis method, a flame Methods such as spray pyrolysis, liquid phase reduction, continuous liquid phase synthesis, and spray drying are known (Patent Documents 3 and 4).

JP 2003-252627 A JP 2006-265094 A JP 2006-239959 A JP 2006-336060 A

In pastes and inks used for mounting and connection of electronic parts and semiconductors, metal particles that are often used can reduce the particle size and cause mutual sintering of particles even when heated at low temperatures, resulting in metallic conductivity. For this reason, metal fine particles have been used practically, but in order to apply to a process at a lower temperature, it is necessary to perform alloying that lowers the melting point of the particles.
In the method for producing fine particles described in Patent Documents 1 to 4, it is a fact that a technology for commercially producing substantially spherical fine particles has not yet been established for general-purpose copper alloy fine particles.
Further, in the paste or ink used for mounting connection, in order to obtain a uniform connection state by uniform particle dispersion, it is desired that the alloy particles used have a spherical shape and a small particle diameter. However, the alloy particles produced by the pulverization method often have a large particle size or an irregular shape, resulting in variations in the connection state and a problem that the connection temperature cannot be achieved at a low temperature.
The present invention relates to a method for producing copper-phosphorus alloy fine particles, copper-tin alloy fine particles, and copper-tin-phosphorous alloy fine particles that are spherical and have a small particle diameter by performing electrolytic reduction or electroless reduction, and production thereof. It aims at providing the copper alloy fine particles obtained by this.

  In the present invention, when electrolytic reduction or electroless reduction conventionally performed in a liquid phase is performed, a specific dispersion medium is used for electrolytic reduction or non-reduction without using a normally used brightener or gloss auxiliary. It has been found that copper alloy fine particles in which dendrite formation is suppressed can be efficiently produced by electrolytic reduction, and the present invention has been completed.

That is, the “method for producing copper alloy fine particles” according to the first aspect of the present invention includes (1) at least cupric pyrophosphate, alkali metal pyrophosphate and / or alkaline earth metal pyrophosphate, and dispersion. In a reduction reaction solution containing a medium, alloy fine particles made of copper-phosphorus are precipitated by a reduction reaction.
In the “method for producing copper alloy fine particles” which is the first aspect of the present invention, the following aspects (4) to (10) may be further provided.
(4) The dispersion medium is an organic dispersion medium composed of a water-soluble polymer, and is selected from polyethyleneimine, polyvinylpyrrolidone, polyacrylic acid, carboxymethylcellulose, polyacrylamide, polyvinyl alcohol, polyethylene oxide, starch, and gelatin. 1 type or 2 types or more.
(5) When the concentration of the organic dispersion medium in the reduction reaction solution causes the copper-phosphorus alloy fine particles to be precipitated, the mass ratio of the organic dispersion medium to the copper atom ([organic dispersion medium / copper] mass ratio) is 0.01 to 30.
(6) The dispersion medium is a dispersion medium comprising halogen ions, and the source of the halogen ions is hydrogen chloride, potassium chloride, sodium chloride, cuprous chloride, cupric chloride, hydrogen bromide, potassium bromide Sodium bromide, cuprous bromide, cupric bromide, hydrogen iodide, potassium iodide, sodium iodide, cuprous iodide, cupric iodide, hydrogen fluoride, potassium fluoride, fluoride Sodium fluoride, cuprous fluoride, cupric fluoride, calcium chloride, barium chloride, ammonium chloride, calcium bromide, barium bromide, ammonium bromide, calcium iodide, barium iodide, ammonium iodide, and fluoride 1 type, or 2 or more types selected from ammonium fluoride.
(7) When the concentration of the inorganic dispersion medium composed of halogen ions in (6) above in the reduction reaction solution precipitates copper-phosphorus alloy fine particles, the molar ratio of halogen ions to copper atoms ([halogen ion / copper] Molar ratio) is 0.25-100.
(8) The reduction reaction is performed under the condition that the molar ratio ([Cu / P ₂ O ₇ ] molar ratio) between the copper atom and the P ₂ O ₇ ion in the reduction reaction solution is 0.1 to 0.6.
(9) In the method for producing alloy fine particles comprising copper-phosphorus by the reduction reaction, a reduction reaction is performed by applying a voltage between an anode and a cathode provided in the reduction reaction solution, whereby copper-phosphorus is formed near the cathode surface. This is a method of depositing alloy fine particles.
(10) The method for producing copper-phosphorus alloy fine particles by the reduction reaction is a method for precipitating copper-phosphorous alloy fine particles by performing a reduction reaction in the presence of a reducing agent in a reduction reaction solution.

The “method for producing copper alloy fine particles” according to the second aspect of the present invention is as follows. (2) In a reduction reaction solution containing at least cupric pyrophosphate, stannous pyrophosphate, and a dispersion medium, -Precipitating alloy fine particles made of tin.
In the “method for producing copper alloy fine particles” which is the second aspect of the present invention, the following aspects (4) to (7) and (11) to (13) may be further provided.
(4) The dispersion medium is an organic dispersion medium composed of a water-soluble polymer, and is selected from polyethyleneimine, polyvinylpyrrolidone, polyacrylic acid, carboxymethylcellulose, polyacrylamide, polyvinyl alcohol, polyethylene oxide, starch, and gelatin. 1 type or 2 types or more.
(5) The concentration of the organic dispersion medium in the reduction reaction solution is 0.01 to 30 in terms of mass ratio of the organic dispersion medium and copper atoms and tin atoms ([organic dispersion medium / (copper + tin)] mass ratio). It is.
(6) The dispersion medium is a dispersion medium comprising halogen ions, and the source of the halogen ions is hydrogen chloride, potassium chloride, sodium chloride, cuprous chloride, cupric chloride, hydrogen bromide, potassium bromide Sodium bromide, cuprous bromide, cupric bromide, hydrogen iodide, potassium iodide, sodium iodide, cuprous iodide, cupric iodide, hydrogen fluoride, potassium fluoride, fluoride Sodium fluoride, cuprous fluoride, cupric fluoride, calcium chloride, barium chloride, ammonium chloride, calcium bromide, barium bromide, ammonium bromide, calcium iodide, barium iodide, ammonium iodide, and fluoride 1 type, or 2 or more types selected from ammonium fluoride.
(7) The concentration of halogen ions in the reduction reaction solution in (6) above is such that the molar ratio of halogen ions to copper atoms and tin atoms ([halogen ion / (copper + tin)] molar ratio) is 0.5 to 100.
(11) The molar ratio ([Cu / P ₂ O ₇ ] molar ratio) between the copper atom and the P ₂ O ₇ ion in the reduction reaction solution is 0.05 to 0.4, and the tin atom and P ₂ O _7. The reduction reaction is performed under the condition that the molar ratio with ions ([Sn / P ₂ O ₇ ] molar ratio) is 0.05 to 0.4.
(12) The method of producing alloy fine particles comprising copper-tin by the reduction reaction is performed by applying a voltage between an anode and a cathode provided in the reduction reaction solution to perform a reduction reaction near the cathode surface. This is a method of depositing alloy fine particles.
(13) The method for producing copper-tin alloy fine particles by the reduction reaction is a method for precipitating copper-tin alloy fine particles by carrying out a reduction reaction in the presence of a reducing agent in a reduction reaction solution.

The “method for producing fine copper alloy particles” according to the third aspect of the present invention includes (3) at least cupric pyrophosphate, stannous pyrophosphate, alkali metal pyrophosphate and / or alkaline earth metal pyrophosphate. In a reduction reaction solution containing a salt and a dispersion medium, alloy fine particles composed of copper-tin-phosphorus are precipitated by a reduction reaction.
In the “method for producing copper alloy fine particles”, which is the third aspect of the present invention, the following aspects (4) to (7) and (14) to (16) can be further provided.
(4) The dispersion medium is an organic dispersion medium composed of a water-soluble polymer, and is selected from polyethyleneimine, polyvinylpyrrolidone, polyacrylic acid, carboxymethylcellulose, polyacrylamide, polyvinyl alcohol, polyethylene oxide, starch, and gelatin. 1 type or 2 types or more.
(5) The concentration of the organic dispersion medium in the reduction reaction solution is 0.01 to 30 in terms of mass ratio of the organic dispersion medium and copper atoms and tin atoms ([organic dispersion medium / (copper + tin)] mass ratio). It is.
(6) The dispersion medium is a dispersion medium comprising halogen ions, and the source of the halogen ions is hydrogen chloride, potassium chloride, sodium chloride, cuprous chloride, cupric chloride, hydrogen bromide, potassium bromide Sodium bromide, cuprous bromide, cupric bromide, hydrogen iodide, potassium iodide, sodium iodide, cuprous iodide, and cupric iodide, hydrogen fluoride, potassium fluoride, Sodium fluoride, cuprous fluoride, cupric fluoride, calcium chloride, barium chloride, ammonium chloride, calcium bromide, barium bromide, ammonium bromide, calcium iodide, barium iodide, ammonium iodide, and It is 1 type, or 2 or more types chosen from ammonium fluoride.
(7) The concentration of halogen ions in the reduction reaction solution in (6) above is such that the molar ratio of halogen ions to copper atoms and tin atoms ([halogen ion / (copper + tin)] molar ratio) is 0.5 to 100.
(14) The molar ratio ([Cu / P ₂ O ₇ ] molar ratio) between the copper atom and the P ₂ O ₇ ion in the reduction reaction solution is 0.1 to 0.6, and the tin atom and P ₂ O _7. The reduction reaction is carried out under the condition that the molar ratio with ions ([Sn / P ₂ O ₇ ]) is 0.1 to 0.4.
(15) In the method of producing alloy fine particles composed of copper-tin-phosphorus by the reduction reaction, a reduction reaction is performed by applying a voltage between an anode and a cathode provided in the reduction reaction solution, so that copper is formed near the cathode surface. -A method of depositing tin-phosphorus alloy fine particles.
(16) The method for producing alloy fine particles comprising copper-tin-phosphorus by the reduction reaction is a method in which copper-tin-phosphorus alloy fine particles are precipitated by performing a reduction reaction in the presence of a reducing agent in a reduction reaction solution. is there.

Furthermore, this invention is invention regarding the "copper alloy fine particle" which is the 4th-6th aspect shown to following (17)-(19).
(17) The particle diameter made of copper-phosphorus produced by the reduction reaction according to any one of (1), (4) to (10) is in the range of 1 to 500 nm, and the aspect ratio is 10 or less. Certain copper alloy fine particles (fourth embodiment).
(18) The particle diameter made of copper-tin produced by the reduction reaction according to any one of (2), (4) to (7), and (11) to (13) ranges from 1 to 500 nm. And copper alloy fine particles having an aspect ratio of 10 or less (fifth aspect).
(19) The particle diameter of copper-tin-phosphorus produced by the reduction reaction according to any one of (3), (4) to (7), and (14) to (16) is 1 to 500 nm. Copper alloy fine particles having an aspect ratio of 10 or less (sixth aspect).

  Copper-phosphorus, copper-tin, and copper- having a small aspect ratio and a particle diameter of 500 nm or less by performing electrolytic reduction using a dispersion medium in the reduction reaction solution or electroless reduction using a reducing agent. It is possible to easily produce alloy fine particles made of tin-phosphorus.

Hereinafter, the configuration of the present invention will be described in detail.
Hereinafter, a copper-phosphorus alloy is described as a Cu-P alloy, a copper-tin alloy as a Cu-Sn alloy, and a copper-tin-phosphorus alloy as a Cu-Sn-P alloy.
In the present invention, a solution in which a reduction reaction is performed in electrolytic reduction is referred to as a reduction reaction solution. In electroless reduction, at least cupric pyrophosphate, or cupric pyrophosphate and stannous pyrophosphate are dissolved. The aqueous solution is called a reaction aqueous solution, an aqueous solution in which at least the reducing agent is dissolved is called a reducing agent aqueous solution, and a solution obtained by mixing the reaction aqueous solution and the reducing agent aqueous solution is called a reduction reaction solution.
In the present invention, the mass of copper atoms (or the number of moles), the mass of tin atoms (or the number of moles), and the number of moles of P ₂ O ₇ ions in the reduction reaction solution are determined based on the following description.
(I) Mass of copper atom (or number of moles)
The mass (or the number of moles) of copper atoms is the mass (or the number of moles) of copper atoms in all of the copper compounds blended in the reduction reaction solution.
(Ii) Mass of tin atom (or number of moles)
It is the mass (or the number of moles) of tin atoms and the mass (or the number of moles) of tin atoms in all the tin compounds blended in the reduction reaction solution.
_(Iii) P 2 _{O 7} number of moles P ₂ O ₇ ion of the ion is the number of moles of all the _P 2 _{O 7} groups pyrophosphate formulated to a reduction reaction solution.
Moreover, the aspect ratio described about the copper alloy fine particles manufactured by the manufacturing method of this invention means an average aspect ratio.
The [1] dispersion medium, [2] first aspect, [3] second aspect, [4] third aspect, and [5] fourth to sixth aspects in the present invention will be described below.

[1] Dispersion medium In the present invention, an organic dispersion medium or a dispersion medium composed of inorganic halogen ions is used as the dispersion medium. Although the mechanism of the action of the dispersion medium in the present invention is not clear, it is presumed to have the action of promoting the generation of crystal nuclei of the alloy fine particles by the reduction reaction in the reduction reaction solution and further dispersing the generated crystals.
(1) Organic dispersion medium Water-soluble polymer compounds can be used as the organic dispersion medium. As such water-soluble polymer compounds, amine-based polymers such as polyethyleneimine and polyvinylpyrrolidone; polyacrylic acid Examples thereof include hydrocarbon polymers having a carboxylic acid group such as carboxymethylcellulose; acrylamides such as polyacrylamide; polyvinyl alcohol, polyethylene oxide, and starch and gelatin.
Specific examples of the water-soluble polymer compound exemplified above include polyethyleneimine (molecular weight: 100 to 100,000), polyvinylpyrrolidone (molecular weight: 1000 to 500,000), carboxymethyl cellulose (to the carboxymethyl group of the hydroxyl group Na salt). Substitution degree: 0.4 or more, molecular weight: 1000 to 100,000, polyacrylamide (molecular weight: 100 to 6,000,000), polyvinyl alcohol (molecular weight: 1000 to 100,000), polyethylene glycol (molecular weight: 100) -50,000), polyethylene oxide (molecular weight: 50,000-900,000), gelatin (average molecular weight: 61,000-67,000), water-soluble starch and the like. Since the polymer compound having a number average molecular weight in the range shown in the parentheses is water-soluble, it can be suitably used as the organic dispersion medium of the present invention. These organic dispersion media can be used in combination of two or more.
When the concentration of the organic dispersion medium in the reduction reaction solution precipitates copper-phosphorus alloy fine particles, the mass ratio of the organic dispersion medium to the copper atoms ([organic dispersion medium / copper] mass ratio) is preferably 0.01 to 30. More preferably, it is 0.5-10. When the ratio is less than 0.01, the reduction reaction is remarkably slow, and when it exceeds 30, the effect of addition is lost.
When the copper-tin alloy or copper-tin-phosphorus alloy fine particles are deposited, the mass ratio of the organic dispersion medium to the copper atoms and tin atoms ([organic dispersion medium / (copper + tin)] mass ratio) is preferably It is 0.01-30, More preferably, it is 0.5-10. When the ratio is less than 0.01, the reduction reaction is remarkably slow, and when it exceeds 30, the effect of addition is lost.

(2) Dispersion medium composed of halogen ions The source of halogen ions as a dispersion medium composed of halogen ions is hydrogen chloride, potassium chloride, sodium chloride, cuprous chloride, cupric chloride, hydrogen bromide, bromide. Potassium, sodium bromide, cuprous bromide, cupric bromide, hydrogen iodide, potassium iodide, sodium iodide, cuprous iodide, cupric iodide, hydrogen fluoride, potassium fluoride, Sodium fluoride, cuprous fluoride, cupric fluoride, calcium chloride, barium chloride, ammonium chloride, calcium bromide, barium bromide, ammonium bromide, calcium iodide, barium iodide, ammonium iodide, and One or more selected from ammonium fluoride. These can also be used in mixture of 2 or more types.

When Cu-P alloy fine particles are precipitated, the molar ratio of halogen ions to copper atoms ([halogen ion / copper] molar ratio) in the reduction reaction solution is preferably 0.25 to 100, more preferably 0.5. ~ 20. When the molar ratio exceeds 100, the reduction reaction becomes slow. On the other hand, when the molar ratio is less than 0.25, the addition effect is small.
Moreover, when depositing Cu—Sn alloy or Cu—Sn—P alloy fine particles, the molar ratio of halogen ion, copper atom and tin atom in the reduction reaction solution ([halogen ion / (copper + tin)] mol The ratio] is preferably 0.5 to 100, more preferably 0.5 to 20. When the molar ratio exceeds 100, the reduction reaction becomes slow, whereas when the molar ratio is less than 0.5, the effect of addition is small.
The compound serving as a source of halogen ions may be any compound in which at least the halogen ions have an ionic bond, and the amount of halogen ions in the reduction reaction solution is the amount of halogen having an ionic bond in the compound. is there.

[2] First Aspect “The method for producing copper alloy fine particles” according to the first aspect of the present invention comprises at least cupric pyrophosphate, alkali metal pyrophosphate and / or alkaline earth metal pyrophosphate, In addition, in the reduction reaction solution containing the dispersion medium, alloy fine particles made of Cu-P are precipitated by a reduction reaction.
The following descriptions (1) to (3) are common to electrolytic reduction and electroless reduction.
(1) Alkali metal pyrophosphate and alkaline earth metal pyrophosphate Examples of the alkali metal pyrophosphate include lithium pyrophosphate, sodium pyrophosphate, and potassium pyrophosphate, and examples of the alkaline earth metal pyrophosphate include , Beryl pyrophosphate, magnesium pyrophosphate, and calcium pyrophosphate. Two or more of these may be used in combination.

(2) Composition of reduction reaction solution In the first embodiment, cuprate pyrophosphate, alkali metal pyrophosphate, or alkaline earth is used as the reduction reaction solution for depositing alloy fine particles made of Cu-P by the reduction reaction. Metal pyrophosphate (hereinafter, “alkali metal pyrophosphate and / or alkaline earth metal pyrophosphate” may be referred to as “alkali metal pyrophosphate”) and a dispersion medium are included.
Since the second copper pyrophosphate _{(Cu 2 P 2 O 7 ·} 3H 2 O) it is insoluble in water, relative to cupric 1 mole pyrophosphoric acid, by reacting an alkali metal such as pyrophosphates, water-soluble complex salt Form. In the range of pH 7 to 9.5 in which the reduction reaction is performed, Cu (P ₂ O ₇ ) ₂ ⁶⁻ having a molar ratio of copper and pyrophosphate of 1: 2 is formed, and this further undergoes secondary dissociation, and Cu It is presumed that ²⁺ and 2P ₂ O ₇ ^4- are produced, and the divalent copper ions are reduced to precipitate particles.
In a first aspect, the molar ratio of copper atoms and _P 2 _{O 7} ion reduction reaction solution ([Cu _/ P 2 _{O 7]} molar ratio) is preferably from 0.1 to 0.6, more preferably 0.3 to 0.5.
The concentration of cupric pyrophosphate in the reduction reaction solution, the concentration of pyrophosphate such as alkali metal, and the concentration of pH adjuster (for example, sodium hypophosphite) The conditions are almost the same.

(3) Additives and the like to be blended in the reduction reaction solution The dispersion medium is as described in the section “[1] Dispersion medium”.
On the other hand, when a brightener (a reaction product having a molar ratio of 1: 1 between an amine derivative and epihalohydrin) or a gloss auxiliary (aldehyde derivative such as paraformaldehyde) is added, it becomes a film and suppresses precipitation of particulate matter. Addition should be avoided.

(4) In the case of electrolytic reduction (i) Electrode (anode and cathode) materials, etc. The cathode is preferably platinum, carbon, etc., and the anode is made of Cu, Cu—Sn alloy, Cu—Sn—P alloy, carbon, platinum, etc. preferable. In addition, in order to desorb and collect particles deposited in the vicinity of the cathode surface, it is possible to adopt a structure capable of imparting oscillation such as ultrasonic vibration to the cathode.
(Ii) Electrolytic reduction reaction The pH of the electrolytic reduction reaction is preferably adjusted to a range of 7 to 10 in the weak alkaline region, more preferably 8 to 9. If the pH is less than 7, pyrophosphate may be changed to orthophosphate, which may have an adverse effect such as preventing the reduction reaction from proceeding uniformly. If the pH exceeds 10, the current density range becomes narrow, and the current Efficiency may be reduced. The pH can be adjusted by adding an alkali metal hypophosphite or the like.
The current density is preferably about 0.3 to 10 A / dm ² , more preferably about 0.5 to 6 A / dm ² . The reduction temperature is preferably 10 to 70 ° C., the higher the temperature, the faster the reduction reaction rate, and the lower the temperature, the smaller the particle size of the precipitated particles.

(Iii) Recovery of copper alloy (Cu—P alloy) fine particles from the electrolytic solution After completion of the electrolytic reduction reaction, the Cu—P alloy fine particles adhering to the electrode surface are recovered by washing the electrode or the like. As a recovery method, it is possible to apply a reverse current to the electrode, desorb the fine particles adhering to the electrode surface, and recover the precipitate. Further, as described above, it is possible to carry out recovery by giving a swing such as ultrasonic vibration to the cathode.
The Cu—P alloy fine particles thus obtained are substantially spherical with a relatively small aspect ratio as a result of suppressing dendrite formation. Further, the resulting particles, oxides contained as an impurity is not more than about 5 wt% as CuO and / or Cu 2 _O.

(5) In the case of electroless reduction (i) Reaction aqueous solution, reducing agent aqueous solution The reaction aqueous solution contains the above-described cupric pyrophosphate and pyrophosphates such as alkali metals. Although the reducing agent and the dispersion medium are dissolved in the reducing agent aqueous solution, the dispersion medium may be dissolved in the reaction aqueous solution. As the reducing agent used here, a commonly used reducing agent can be used, but sodium borohydride, hydrazine, lithium aluminum hydride and the like are preferable, and a preferable concentration thereof is a mole relative to a copper atom in the reduction reaction solution. The ratio ([reducing agent / copper] molar ratio) is 10 to 500.
As the dispersion medium, the above-described organic dispersion medium or halogen ions are used. Further, the preferred concentration of the dispersion medium is as described above.

(Ii) Reduction reaction A preferable reduction temperature is 10 to 50 ° C, and a preferable pH is 5.0 to 7.8.
The above reaction aqueous solution is added dropwise to a reducing agent aqueous solution containing the above reducing agent and a dispersion medium, or a reduction reaction is performed by batch charging. While thoroughly stirring the reaction solution, Cu—P alloy fine particles are precipitated.
(Iii) Recovery of copper alloy (Cu-P alloy) fine particles from the reduction reaction solution To a solution containing the copper alloy fine particles obtained by the above method, an aggregation accelerator such as chloroform is added and stirred well. After stirring, the mixture is supplied to a centrifuge or the like to collect the particle component.
Thereafter, the particle component is put into an aqueous solution, and after thoroughly stirring using, for example, an ultrasonic homogenizer, water washing is performed to collect the particle component with a centrifuge several times, and then the obtained particle and an appropriate amount of butanol are mixed. It is desirable to perform the alcohol washing several times with a centrifuge after collecting the components and stirring well using an ultrasonic homogenizer.
Through the above steps, Cu—P alloy fine particles from which impurities such as a reducing agent are sufficiently removed can be obtained.

[3] Second Aspect The “method for producing copper alloy fine particles” according to the second aspect of the present invention is a reduction reaction solution containing at least cupric pyrophosphate, stannous pyrophosphate, and a dispersion medium. The alloy fine particles made of Cu—Sn are precipitated by a reduction reaction.
(1) Dispersion medium The dispersion medium is as described in the above section “[1] Dispersion medium”.
(2) Composition of aqueous reaction solution In the second embodiment, the reduction reaction solution is an aqueous solution containing at least cupric pyrophosphate, stannous pyrophosphate, and a dispersion medium.
The composition of the reduction reaction solution is preferably such that the molar ratio of copper atom to P ₂ O ₇ ion ([Cu / P ₂ O ₇ ] molar ratio) is 0.05 to 5 by adding pyrophosphate such as alkali metal. 0.4, more preferably 0.1 to 0.3, and the molar ratio of tin atoms to P ₂ O ₇ ions ([Sn / P ₂ O ₇ ] molar ratio) is preferably 0.05 to 0.00. It is desirable to adjust to 4, more preferably 0.1 to 0.3.
If a practical example is given, the compounding quantity of copper ion will preferably be 3-80 g / liter (L), more preferably 7-70 g / L as cupric pyrophosphate, and the compounding quantity of tin ion will be pyrolin. The stannous acid is preferably 3 to 60 g / L, more preferably 15 to 50 g / L.

(3) In the case of electrolytic reduction (i) Electrode (anode and cathode) materials, etc. The same as described in the first embodiment.
(Ii) Electrolytic reduction reaction Except for the composition of the reduction reaction solution, it is the same as described in the first embodiment.

(Iii) Recovery of copper alloy (Cu—Sn alloy) fine particles from the electrolytic solution The same as described in the first aspect.
The Cu—Sn alloy fine particles thus obtained are substantially spherical with a relatively small aspect ratio as a result of suppressing dendrite formation. Further, the resulting particles, oxides contained as impurities than 5 wt% as CuO and / or Cu 2 _O, are included as respective oxides and tin oxide are 5 wt% or less.

(4) Electroless reduction (i) Reaction aqueous solution, reducing agent aqueous solution The reaction aqueous solution is an aqueous solution containing cupric pyrophosphate and stannous pyrophosphate.
Separately from the reaction aqueous solution, a reducing agent aqueous solution in which a predetermined amount of a reducing agent and a dispersion medium are dissolved is prepared. The dispersion medium may be dissolved in the reaction aqueous solution.
As the reducing agent to be used, a commonly used reducing agent can be used, but sodium borohydride, hydrazine, lithium aluminum hydride and the like are preferable, and the preferable concentration of the reducing agent in the reduction reaction solution is a copper atom. And a molar ratio ([reducing agent / (copper + tin)] molar ratio) to tin atoms of 10 to 500. As the dispersion medium, the above organic dispersion medium or halogen ions are used. A preferable concentration of the dispersion medium is as described above.

(Ii) Reduction reaction A preferable reduction temperature is 10 to 50 ° C, and a preferable pH is 5.0 to 7.8.
The reaction solution is dropped into the reducing agent aqueous solution or charged all at once to carry out the reduction reaction. The reduction reaction solution is reacted while stirring well to obtain Cu-Sn alloy fine particles.
(Iii) Recovery of copper alloy (Cu—Sn alloy) fine particles from the reduction reaction solution From the reduction reaction solution containing the copper alloy fine particles obtained by the above method, impurities such as a reducing agent are removed to recover the copper-Sn fine particles. The method of performing is the same as in the case of electroless reduction in the first embodiment.

[4] Third Aspect The “method for producing copper alloy fine particles” according to the third aspect of the present invention includes at least cupric pyrophosphate, stannous pyrophosphate, alkali metal pyrophosphate, and / or alkali. In a reduction reaction solution containing an earth metal pyrophosphate and a dispersion medium, alloy fine particles made of Cu—Sn—P are precipitated by a reduction reaction.
(1) Dispersion medium The dispersion medium is as described in the above section “[1] Dispersion medium”.
(2) Alkali metal pyrophosphate and alkaline earth metal pyrophosphate The types of alkali metal pyrophosphate and alkaline earth metal pyrophosphate used are the same as described in the first embodiment.
(3) Composition of reduction reaction solution In the third aspect, the reduction reaction solution comprises cupric pyrophosphate, stannous pyrophosphate, alkali metal pyrophosphate and / or alkaline earth metal pyrophosphate, and a dispersion medium. An aqueous solution containing
The composition of the reduction reaction solution is preferably such that the molar ratio of copper atoms to P ₂ O ₇ ions ([Cu / P ₂ O ₇ ] molar ratio) is 0.1, for example, by blending pyrophosphates such as alkali metals. To 0.6, more preferably 0.1 to 0.3, and the molar ratio of tin atom to P ₂ O ₇ ion ([Sn / P ₂ O ₇ ] molar ratio) is preferably 0.1 to 0. .4, more preferably 0.1 to 0.3.

(4) In the case of electrolytic reduction (i) Electrode (anode and cathode) material, etc. The same as described in the first embodiment.
(Ii) Electrolytic reduction reaction Except for the composition of the reduction reaction solution, it is the same as described in the first embodiment.

(Iii) Recovery of copper alloy (Cu—Sn—P alloy) fine particles from the reduction reaction solution The same as described in the first aspect.
(Iv) Precipitated Cu—Sn—P Alloy Fine Particles The Cu—Sn—P alloy fine particles thus obtained are substantially spherical with a relatively small aspect ratio as a result of suppressing dendrite formation. Further, the resulting particles, oxides contained as impurities than 5 wt% as CuO and / or Cu 2 _O, are included as respective oxides and tin oxide are 5 wt% or less.

(5) In the case of electroless reduction (i) Reaction aqueous solution, reducing agent aqueous solution The aqueous reaction solution is an aqueous solution containing the above-described cupric pyrophosphate, stannous pyrophosphate, and pyrophosphates such as alkali metals.
Although the reducing agent and the dispersion medium are dissolved in the reducing agent aqueous solution, the dispersion medium may be dissolved in the reaction aqueous solution.
As the reducing agent to be used, a commonly used reducing agent can be used, but sodium borohydride, hydrazine, lithium aluminum hydride and the like are preferable, and the preferable concentration of the reducing agent in the reduction reaction solution is a copper atom. And a molar ratio ([reducing agent / (copper + tin)] molar ratio) to tin atoms of 10 to 500.
As the dispersion medium, the above organic dispersion medium or halogen ions are used. A preferable concentration of the dispersion medium is as described above.

(Ii) Reduction reaction A preferable reduction temperature is 10 to 50 ° C, and a preferable pH is 5.0 to 7.8.
The reaction solution is dropped into the reducing agent aqueous solution or charged all at once to carry out the reduction reaction. The reduction reaction solution is reacted while being well stirred to obtain Cu-Sn-P alloy fine particles.
(Iii) Recovery of copper alloy (Cu-Sn-P alloy) fine particles from the reduction reaction solution Impurities such as a reducing agent are removed from the reduction reaction solution containing the copper alloy fine particles obtained by the above method to obtain Cu-Sn-. The method for recovering the P alloy fine particles is the same as in the case of electroless reduction in the first embodiment.

[5] Fourth to sixth aspects Copper-phosphorus alloy fine particles (fourth aspect) obtained by the production method according to the first aspect, and copper-tin obtained by the production method according to the second aspect The alloy fine particles (fifth aspect) and the copper-tin-phosphorus alloy fine particles (sixth aspect) obtained by the production method described in the third aspect are subjected to a reduction reaction in the presence of a dispersion medium. The resulting copper alloy fine particles have a dendrite suppressed and the particle size is preferably in the range of 1 to 500 nm, more preferably in the range of 1 to 80 nm, particularly preferably in the range of 1 to 50 nm, and the aspect ratio is preferably A substantially spherical shape of 10 or less, more preferably 5 or less, and particularly preferably 2 or less.

EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to the following examples.
[Example 1]
Cu-P alloy fine particles were prepared by an electrolytic reduction method, and the obtained fine particles were evaluated.
(1) Preparation of Cu-P alloy fine particles 100 g of polyvinyl pyrrolidone (number average molecular weight: 3500) as an organic dispersion medium, 350 g of potassium pyrophosphate, 80 g of cupric pyrophosphate (Cu ₂ P ₂ O ₇ ) (Cu: 0.53) mol / L) and 1000 ml of a reduction reaction solution containing 20 g of sodium hypophosphite. Incidentally, the molar ratio of copper atoms and _P 2 _{O 7} ion in solution ([Cu _/ P 2 _{O 7]} molar ratio) is 0.4.
Next, an electric current was passed between the anode (anode electrode) made of a 2 cm square copper sheet and the cathode (cathode electrode) made of a platinum substrate in this solution at 40 ° C. for 30 minutes. At this time, the applied current density was 5 A / dm ² .
The obtained colloid solution was collected on an aluminum mesh to which a carbon support film was attached, and after removing the solvent by drying, 3 g of Cu—P alloy fine particles were obtained.
(2) Evaluation of produced Cu—P alloy fine particles The Cu—P alloy fine particles were observed with a transmission electron microscope (TEM). As a result, the particle size was in the range of 5 to 50 nm and the aspect ratio was 1.5. Further, as a result of analysis by an energy dispersive X-ray analyzer (EDS), the alloy composition is a Cu-2.3 mass% P alloy (hereinafter sometimes referred to as a Cu-2.3% P alloy). Met.

[Example 2]
Cu-P alloy fine particles were prepared by a reduction reaction using a reducing agent, and the obtained fine particles were evaluated.
(1) Preparation of Cu—P alloy fine particles A 1000 ml aqueous reaction solution containing 350 g of potassium pyrophosphate, 80 g of cupric pyrophosphate (Cu ₂ P ₂ O ₇ ), and 20 g of sodium hypophosphite was prepared. In addition, the molar ratio ([Cu / P ₂ O ₇ ] molar ratio) of the copper atom and the P ₂ 0 ₇ ion in this solution is 0.4.
Moreover, 1000 ml of reducing agent aqueous solution in which 100 g of sodium borohydride and 150 g of polyethylene glycol (number average molecular weight: 5000) were dissolved as a reducing agent was prepared.
In a nitrogen gas atmosphere, 1000 ml of the reaction aqueous solution was added dropwise to the reducing agent aqueous solution.

As a result of reacting this mixed liquid with sufficient stirring for about 60 minutes, Cu-P alloy fine particles were obtained.
Next, 5 ml of chloroform as a particle extractant (aggregation promoter) was added to 100 ml of the aqueous dispersion of Cu—P alloy fine particles obtained by the above method and stirred well. After stirring for several minutes, the reaction solution was put into a centrifuge and the particle components were collected by precipitation.
Then, after putting the particles obtained in a test tube and an appropriate amount of distilled water, stirring well with an ultrasonic homogenizer, washing with water to collect the particle components with a centrifuge three times, followed by the same test tube Inside, the obtained particles and an appropriate amount of butanol were added, and after thoroughly stirring using an ultrasonic homogenizer, alcohol washing for recovering the particle components with a centrifuge was performed three times.
By the above operation, 2.5 g of Cu—P alloy fine particles were obtained.
(2) Evaluation of produced Cu—P alloy fine particles The Cu—P alloy fine particles were observed with a transmission electron microscope (TEM). The particle diameter was in the range of 5 to 50 nm and the aspect ratio was 1.2. Moreover, as a result of analysis by an energy dispersive X-ray analyzer (EDS), the alloy composition was Cu-2.3 mass% P alloy.

[Example 3]
Cu—Sn alloy fine particles were prepared by an electrolytic reduction method, and the obtained alloy fine particles were evaluated.
(1) Preparation of Cu—Sn alloy fine particles 160 g of potassium pyrophosphate, 23 g of stannous pyrophosphate (Sn ₂ P ₂ O ₇ ), 7.5 g of cupric pyrophosphate (Cu ₂ P ₂ O ₇ ), and polyvinylpyrrolidone A 1000 ml reduction reaction solution containing 100 g (number average molecular weight: 3500) was prepared. The molar ratio of copper atoms to P ₂ O ₇ ions in this solution ([Cu / P ₂ O ₇ ] molar ratio) was 0.09, and the molar ratio of tin atoms to P ₂ O ₇ ions ([Sn / P ₂ O ₇ ] molar ratio) is 0.2.
Next, a current was passed between an anode (anode electrode) made of a 2 cm square copper sheet and a cathode (cathode electrode) made of a platinum substrate in this solution at 45 ° C. for 30 minutes. At this time, the applied current density was 5 A / dm ² . By the electrolytic reduction, 2.1 g of Cu—Sn alloy fine particles were obtained.
(2) Evaluation of produced Cu—Sn alloy fine particles The obtained Cu—Sn alloy fine particles were observed with a transmission electron microscope (TEM). The particle diameter was in the range of 5 to 65 nm and the aspect ratio was 1.4. It was. As a result of analysis by an energy dispersive X-ray analyzer (EDS), the alloy composition was Cu / Sn = 65/35 in mass ratio.

[Example 4]
Cu-Sn alloy fine particles were prepared by a reduction reaction using a reducing agent, and the obtained fine particles were evaluated.
(1) Preparation of Cu-Sn alloy fine particles 1000 ml containing 160 g of potassium pyrophosphate, 23 g of stannous pyrophosphate (Sn ₂ P ₂ O ₇ ), and 7.5 g of cupric pyrophosphate (Cu ₂ P ₂ O ₇ ) An aqueous reaction solution was prepared. The molar ratio of copper atoms and P ₂ O ₇ ions in this solution ([Cu / P ₂ O ₇ ] molar ratio) was 0.09, and the molar ratio of tin atoms to P ₂ O ₇ ions ([Sn / P ₂ O ₇ ] molar ratio) is 0.2.
Moreover, 1000 ml of reducing agent aqueous solution which dissolved 100 g of lithium aluminum hydride as a reducing agent and 100 g of polyvinylpyrrolidone (number average molecular weight: 3500) as a dispersion medium was prepared.
In a nitrogen gas atmosphere, 1000 ml of the reaction aqueous solution was added dropwise to the reducing agent aqueous solution.
As a result of reacting this mixed solution at pH 8.17 and a temperature of 50 ± 5 ° C. for about 60 minutes with good stirring, metal fine particles were obtained.

Next, 5 ml of chloroform as a particle extractant (aggregation promoter) was added to 100 ml of the aqueous dispersion of Cu—Sn alloy fine particles obtained by the above method and stirred well. After stirring for several minutes, the reaction solution was put into a centrifuge and the particle components were collected by precipitation.
Then, after putting the particles obtained in a test tube and an appropriate amount of distilled water, stirring well with an ultrasonic homogenizer, washing with water to collect the particle components with a centrifuge three times, followed by the same test tube Inside, the obtained particles and an appropriate amount of butanol were added, and after thoroughly stirring using an ultrasonic homogenizer, alcohol washing for recovering the particle components with a centrifuge was performed three times.
By the above operation, Cu—Sn alloy fine particles were obtained.
(2) Evaluation of generated Cu—Sn alloy fine particles The obtained Cu—Sn alloy fine particles were observed with a transmission electron microscope (TEM), the particle diameter was in the range of 5 to 50 nm, and the aspect ratio was 1.3 or less. there were. Further, as a result of analysis by an energy dispersive X-ray analyzer (EDS), the alloy composition was Cu / Sn = 61/39 by mass ratio.

[Example 5]
Cu—Sn—P alloy fine particles were prepared by an electrolytic reduction method, and the obtained fine particles were evaluated.
(1) Preparation of Cu—Sn—P alloy fine particles 100 g of polyvinyl pyrrolidone (number average molecular weight: 3500) as organic dispersion medium, 23 g of stannous pyrophosphate (Sn ₂ P ₂ O ₇ ), cupric pyrophosphate (Cu ₂₎ P ₂ O ₇₎ 15g, potassium pyrophosphate (K ₄ P ₂ O ₇₎ was prepared reductive reaction solution 1000ml containing 160 g. The molar ratio of copper atoms and P ₂ O ₇ ions in this solution ([Cu / P ₂ O ₇ ] molar ratio) was 0.16, and the molar ratio of tin atoms to P ₂ O ₇ ions ([Sn / P ₂ O ₇ ] molar ratio) is 0.18.
Next, a current was passed between the anode (anode electrode) made of a 2 cm square copper sheet and the cathode (cathode electrode) made of a platinum substrate in this solution at 60 ° C. for 30 minutes. At this time, the applied current density was 5 A / dm ² .
By electrolytic reduction reaction, 2.5 g of Cu—Sn—P alloy fine particles were obtained.
(2) Evaluation of produced Cu—Sn—P alloy fine particles The obtained Cu—Sn—P alloy fine particles were observed with a transmission electron microscope (TEM). The particle diameter was in the range of 5 to 50 nm, and the aspect ratio was 1. .3 or less. As a result of analysis by an energy dispersive X-ray analyzer (EDS), the alloy composition was Cu / Sn / P = 76/22/2 in mass ratio.

[Example 6]
Cu-Sn-P alloy fine particles were precipitated by a reduction reaction using a reducing agent, and the obtained fine particles were evaluated.
(1) Preparation of Cu—Sn—P alloy fine particles Stannous pyrophosphate (Sn ₂ P ₂ O ₇ ) 23 g, cupric pyrophosphate (Cu ₂ P ₂ O ₇ ) 15 g, potassium pyrophosphate (K ₄ P ₂₎ A 1000 ml aqueous reaction solution containing 160 g of O ₇ ) was prepared. The molar ratio of copper atoms and P ₂ O ₇ ions in this solution ([Cu / P ₂ O ₇ ] molar ratio) was 0.16, and the molar ratio of tin atoms to P ₂ O ₇ ions ([Sn / P ₂ O ₇ ] molar ratio) is 0.18.
Also, a 1000 ml reducing agent aqueous solution was prepared by dissolving 100 g sodium borohydride as the reducing agent and 150 g polyethylene glycol as the organic dispersion medium.
In a nitrogen gas atmosphere, 1000 ml of the reaction aqueous solution was added dropwise to the reducing agent aqueous solution.
This mixture was reacted in a mini barrel at pH 8.17 and a bath temperature of 50 ± 5 ° C. for about 60 minutes with good stirring. As a result, metal fine particles coated with polyethylene glycol were obtained.

Next, 5 ml of chloroform as a particle extractant (aggregation accelerator) was added to 100 ml of an aqueous dispersion of Cu—Sn—P alloy fine particles coated with PVP obtained by the above method and stirred well. After stirring for several minutes, the reaction solution was put into a centrifuge and the particle components were collected by precipitation.
Then, after putting the particles obtained in a test tube and an appropriate amount of distilled water, stirring well with an ultrasonic homogenizer, washing with water to collect the particle components with a centrifuge three times, followed by the same test tube Inside, the obtained particles and an appropriate amount of butanol were added, and after thoroughly stirring using an ultrasonic homogenizer, alcohol washing for recovering the particle components with a centrifuge was performed three times.
By the above operation, 3.2 g of Cu—Sn—P alloy was obtained.

(2) Evaluation of produced Cu—Sn—P alloy fine particles The obtained Cu—Sn—P alloy fine particles were observed with a transmission electron microscope (TEM). The particle diameter was in the range of 5 to 50 nm, and the aspect ratio was 1. .3 or less. As a result of analysis by an energy dispersive X-ray analyzer (EDS), the alloy composition was Cu / Sn / P = 78/20/2 in terms of mass ratio.

[Example 7]
Cu-Sn alloy fine particles were prepared by an electrolytic reduction method in which halogen ions were added as a dispersion medium, and the obtained alloy fine particles were evaluated.
(1) Preparation of Cu—Sn alloy fine particles 2.8 g of sodium chloride, 150 g of potassium pyrophosphate, 23 g of stannous pyrophosphate (Sn ₂ P ₂ O ₇ ), and cupric pyrophosphate (Cu ₂ P ₂ O ₇ ) A 1000 ml reduction reaction solution containing 7.5 g was prepared. The molar ratio of copper atoms to P ₂ O ₇ ions ([Cu / P ₂ O ₇ ] molar ratio) in this solution was 0.09, and the molar ratio of tin atoms to P ₂ O ₇ ions ([Sn / P ₂ O ₇ ] molar ratio) is 0.2.
Next, a current was passed between an anode (anode electrode) made of a 2 cm square copper sheet and a cathode (cathode electrode) made of a platinum substrate in this solution at 45 ° C. for 30 minutes. At this time, the applied current density was 5 A / dm ² . By the electrolytic reduction, 2.1 g of Cu—Sn alloy fine particles were obtained.
(2) Evaluation of produced Cu—Sn alloy fine particles The obtained Cu—Sn alloy fine particles were observed with a transmission electron microscope (TEM). The particle diameter was in the range of 5 to 22 nm and the aspect ratio was 1.05. It was. As a result of analysis by an energy dispersive X-ray analyzer (EDS), the alloy composition was Cu / Sn = 67/33 in mass ratio.
It was found that particles having a small particle size and a nearly spherical shape can be produced.

[Example 8, Comparative Example 1]
The copper alloy fine particles obtained in Examples 1 to 7 and the Cu-P alloy fine particle sample prepared in Comparative Example 1 below were each dispersed in ethylene glycol, and the obtained dispersion was applied to a glass substrate with a spin coater. The conductivity when fired and used as a paste or the like was evaluated.
(1) Comparative Example 1
Cu-P alloy fine particles for evaluation were prepared by the following method.
1000 ml of an aqueous reaction solution containing 300 g of cupric pyrophosphate (Cu ₂ P ₂ O ₇ ) and 20 g of sodium hypophosphite (molar ratio of copper atoms and P ₂ O ₇ ions in this solution ([Cu / P ₂ O ₇ ] molar ratio) was 2), and 1000 ml of a reducing agent aqueous solution in which 100 g of sodium borohydride and 150 g of polyethylene glycol (number average molecular weight: 5000) were dissolved as a reducing agent was prepared.
In a nitrogen gas atmosphere, 1000 ml of the above reaction aqueous solution was dropped into the reducing agent aqueous solution and reacted with stirring well for about 60 minutes to produce copper alloy fine particles. After completion of the reaction, chloroform was added to the aqueous reaction solution to aggregate and precipitate the particles, and Cu—P alloy fine particles (Cu—0.05% P fine particles) were recovered. 5 g of the Cu—P alloy fine particles were added to 50 ml of ethylene glycol and stirred and dispersed to prepare a copper alloy fine particle dispersion.
The obtained Cu—P alloy fine particles were observed with a transmission electron microscope (TEM). As a result, the particle size was in the range of 10 to 80 nm and the aspect ratio was 1.2. Further, P was not detected as a result of analysis by an energy dispersive X-ray analyzer (EDS). The alloy particles were dissolved in sulfuric acid and subjected to chemical analysis. As a result, the alloy composition was Cu / P = 99.95 / 0.05 in terms of mass ratio.

(2) Preparation of copper alloy fine particle dispersions obtained in Examples 1 to 7 5 g of the copper alloy fine particles obtained in Examples 1 to 7 were added to 50 ml of ethylene glycol, and stirred and dispersed. A liquid was prepared.
(3) Firing evaluation of dispersions in which copper alloy fine particles are dispersed in ethylene glycol Examples 1 to 7 obtained above and Comparative Example 1 The dispersions obtained were applied to a glass substrate (size: 2 cm × 4 cm) with a spin coater. It was applied, heated and fired at 180 ° C. for 2 hours in an argon atmosphere, and then cooled to form a metal thin film on the glass substrate. The resistance value of the metal thin film was measured by a four-terminal method (use measuring machine: manufactured by Keithley, digital multimeter DMM2000 type (four-terminal electric resistance measurement mode)).
The specific resistance value for the dispersion prepared in Comparative Example 1 was as high as 20 Ωcm, whereas the specific resistance value for the dispersion prepared from the samples obtained in Examples 1 to 7 was 8 to 65 μΩcm. The resistivity value was very small.
From the above results, it was confirmed that the copper alloy fine particles obtained in the present invention can be fired on the substrate even at a low firing temperature.

Claims (19)

  A copper alloy that deposits alloy fine particles composed of copper-phosphorus by a reduction reaction in a reduction reaction solution containing at least cupric pyrophosphate, alkali metal pyrophosphate and / or alkaline earth metal pyrophosphate, and a dispersion medium A method for producing fine particles.   A method for producing copper alloy fine particles, comprising depositing alloy fine particles composed of copper-tin by a reduction reaction in a reduction reaction solution containing at least cupric pyrophosphate, stannous pyrophosphate, and a dispersion medium.   In a reduction reaction solution containing at least cupric pyrophosphate, stannous pyrophosphate, alkali metal pyrophosphate and / or alkaline earth metal pyrophosphate, and a dispersion medium, copper-tin-phosphorus is formed by a reduction reaction. A method for producing copper alloy fine particles, in which alloy fine particles are precipitated.   The dispersion medium is an organic dispersion medium composed of a water-soluble polymer, and is selected from polyethyleneimine, polyvinylpyrrolidone, polyacrylic acid, carboxymethylcellulose, polyacrylamide, polyvinyl alcohol, polyethylene oxide, starch, and gelatin. Or the manufacturing method of the copper alloy fine particles of any one of Claim 1 thru | or 3 which is 2 or more types. When the concentration of the organic dispersion medium in the reduction reaction solution precipitates copper-phosphorus alloy fine particles, the mass ratio of the organic dispersion medium to the copper atoms ([organic dispersion medium / copper] mass ratio) is 0.01 to 30. ,
In the case of depositing copper-tin alloy or copper-tin-phosphorus alloy fine particles, the organic dispersion medium and the mass ratio of copper atom and tin atom ([organic dispersion medium / (copper + tin)] mass ratio) is 0.01. ~ 30,
The method for producing copper alloy fine particles according to any one of claims 1 to 4.   The dispersion medium is an inorganic dispersion medium composed of halogen ions, and the source of the halogen ions is hydrogen chloride, potassium chloride, sodium chloride, cuprous chloride, cupric chloride, hydrogen bromide, potassium bromide, odor Sodium iodide, cuprous bromide, cupric bromide, hydrogen iodide, potassium iodide, sodium iodide, cuprous iodide, cupric iodide, hydrogen fluoride, potassium fluoride, sodium fluoride , Cuprous fluoride, cupric fluoride, calcium chloride, barium chloride, ammonium chloride, calcium bromide, barium bromide, ammonium bromide, calcium iodide, barium iodide, ammonium iodide, and ammonium fluoride The manufacturing method of the copper alloy fine particle of any one of Claim 1 thru | or 3 which is 1 type, or 2 or more types selected from these.   When copper-phosphorus alloy fine particles are deposited in the reduction reaction solution of the inorganic dispersion medium composed of halogen ions, the molar ratio of halogen ions to copper atoms ([halogen ion / copper] molar ratio) is 0.25. ˜100, when copper-tin alloy or copper-tin-phosphorus alloy fine particles are deposited, the molar ratio of halogen ion, copper atom and tin atom ([halogen ion / (copper + tin)] molar ratio ) Is 0.5 to 100, the method for producing copper alloy fine particles according to any one of claims 1 to 3 and 6. The reduction reaction is performed under the condition that the molar ratio of copper atoms and P ₂ O ₇ ions ([Cu / P ₂ O ₇ ] molar ratio) in the reduction reaction solution is 0.1 to 0.6. The method for producing copper alloy fine particles according to any one of claims 1 and 4 to 7.   In the method for producing alloy fine particles composed of copper-phosphorus by the reduction reaction, the copper-phosphorus alloy fine particles are formed near the cathode surface by performing a reduction reaction by applying a voltage between an anode and a cathode provided in the reduction reaction solution. The method for producing copper alloy fine particles according to any one of claims 1 and 4 to 8, wherein the copper alloy fine particles are deposited.   The method for producing alloy fine particles comprising copper-phosphorus by the reduction reaction is a method for precipitating copper-phosphorus alloy fine particles by performing a reduction reaction in the presence of a reducing agent in a reduction reaction solution, and The method for producing copper alloy fine particles according to any one of 4 to 8. The molar ratio ([Cu / P ₂ O ₇ ] molar ratio) between the copper atom and the P ₂ O ₇ ion in the reduction reaction solution is 0.05 to 0.4, and the tin atom and the P ₂ O ₇ ion are The reduction reaction is performed under a condition where the molar ratio ([Sn / P ₂ O ₇ ] molar ratio) is 0.05 to 0.4, according to any one of claims 2 and 4 to 7 The manufacturing method of the copper alloy fine particle of description.   In the method for producing alloy fine particles composed of copper-tin by the reduction reaction, the copper-tin alloy fine particles are formed near the cathode surface by applying a voltage between the anode and the cathode provided in the reduction reaction solution. The method for producing copper alloy fine particles according to any one of claims 2, 4 to 7, and 11, wherein the copper alloy fine particles are deposited.   The method for producing alloy fine particles composed of copper-tin by the reduction reaction is a method of depositing copper-tin alloy fine particles by performing a reduction reaction in the presence of a reducing agent in a reduction reaction solution. Thru | or 7, and the manufacturing method of the copper alloy fine particle of any one of 11. The molar ratio ([Cu / P ₂ O ₇ ] molar ratio) of the copper atom and P ₂ O ₇ ion in the reduction reaction solution is 0.1 to 0.6, and the tin atom and P ₂ O ₇ ion are 8. The reduction reaction is carried out under the condition that the molar ratio ([Sn / P ₂ O ₇ ]) molar ratio is 0.1 to 0.4, according to any one of claims 3 and 4 to 7, The manufacturing method of the copper alloy fine particle of description.   The method for producing alloy fine particles composed of copper-tin-phosphorous by the reduction reaction includes applying a voltage between an anode and a cathode provided in the reduction reaction solution to perform a reduction reaction near the cathode surface. The method for producing copper alloy fine particles according to any one of claims 3, 4 to 7, and 14, wherein the phosphorus alloy fine particles are precipitated.   The method for producing alloy fine particles composed of copper-tin-phosphorus by the reduction reaction is a method for precipitating copper-tin-phosphorus alloy fine particles by performing a reduction reaction in the presence of a reducing agent in a reduction reaction solution. Item 15. The method for producing copper alloy fine particles according to any one of Items 3, 4 to 7, and 14.   Copper alloy fine particles produced by the reduction reaction according to any one of claims 1, 4 to 10, and having a particle diameter of copper-phosphorus in the range of 1 to 500 nm and an aspect ratio of 10 or less. .   The particle diameter made of copper-tin produced by the reduction reaction according to any one of claims 2, 4 to 7, and 11 to 13 is in the range of 1 to 500 nm, and the aspect ratio is 10 or less. Copper alloy fine particles.   The particle diameter made of copper-tin-phosphorus produced by the reduction reaction according to any one of claims 3, 4 to 7, and 14 to 16 is in the range of 1 to 500 nm, and the aspect ratio is 10 or less copper alloy fine particles.