WO2020044983A1 - Production method for copper particles, bonding paste, semiconductor device, and electrical and electronic components - Google Patents

Production method for copper particles, bonding paste, semiconductor device, and electrical and electronic components Download PDF

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Publication number
WO2020044983A1
WO2020044983A1 PCT/JP2019/030832 JP2019030832W WO2020044983A1 WO 2020044983 A1 WO2020044983 A1 WO 2020044983A1 JP 2019030832 W JP2019030832 W JP 2019030832W WO 2020044983 A1 WO2020044983 A1 WO 2020044983A1
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Prior art keywords
acid
copper
copper particles
compound
bonding
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PCT/JP2019/030832
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French (fr)
Japanese (ja)
Inventor
知直 菊池
勇哉 似内
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京セラ株式会社
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Publication of WO2020044983A1 publication Critical patent/WO2020044983A1/en

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F1/00—Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F7/00—Manufacture of composite layers, workpieces, or articles, comprising metallic powder, by sintering the powder, with or without compacting wherein at least one part is obtained by sintering or compression
    • B22F7/06—Manufacture of composite layers, workpieces, or articles, comprising metallic powder, by sintering the powder, with or without compacting wherein at least one part is obtained by sintering or compression of composite workpieces or articles from parts, e.g. to form tipped tools
    • B22F7/08—Manufacture of composite layers, workpieces, or articles, comprising metallic powder, by sintering the powder, with or without compacting wherein at least one part is obtained by sintering or compression of composite workpieces or articles from parts, e.g. to form tipped tools with one or more parts not made from powder
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F9/00—Making metallic powder or suspensions thereof
    • B22F9/16—Making metallic powder or suspensions thereof using chemical processes
    • B22F9/18—Making metallic powder or suspensions thereof using chemical processes with reduction of metal compounds
    • B22F9/24—Making metallic powder or suspensions thereof using chemical processes with reduction of metal compounds starting from liquid metal compounds, e.g. solutions
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
    • H01B1/02—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors mainly consisting of metals or alloys
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
    • H01B1/20—Conductive material dispersed in non-conductive organic material
    • H01B1/22—Conductive material dispersed in non-conductive organic material the conductive material comprising metals or alloys
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B13/00—Apparatus or processes specially adapted for manufacturing conductors or cables
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer
    • H01L21/50—Assembly of semiconductor devices using processes or apparatus not provided for in a single one of the subgroups H01L21/06 - H01L21/326, e.g. sealing of a cap to a base of a container
    • H01L21/52—Mounting semiconductor bodies in containers

Definitions

  • the present disclosure relates to a method for producing copper particles, a joining paste, a semiconductor device manufactured using the joining paste, and an electric / electronic component.
  • the semiconductor element may be bonded to an organic substrate having a heat dissipation mechanism such as a thermal via.
  • the material for bonding the semiconductor element needs to have high thermal conductivity.
  • white light emitting LEDs they have been widely used for lighting devices such as backlighting, ceiling lights, and downlights of full color liquid crystal screens.
  • the adhesive for bonding the light emitting element and the substrate may be discolored by heat and light, or the electric resistance value may change with time.
  • the bonding material may lose its adhesive strength at the solder melting temperature at the time of soldering the electronic component, and may be peeled off.
  • the white light emitting LED causes an increase in the amount of heat generated by the light emitting element chip, and accordingly, the structure of the LED and members used therein are required to have improved heat radiation.
  • a metal filler such as silver powder and copper powder and a ceramic filler such as aluminum nitride and boron nitride are used as fillers at a high content in an organic binder. It is necessary to disperse (for example, see Patent Document 2).
  • Patent Document 3 a bonding method using silver nanoparticles that enables bonding at a lower temperature than silver in a bulk body has been attracting attention.
  • silver particles are excellent in conductivity, but in consideration of high price and migration resistance, substitution with other metals is being studied. Therefore, attention is now focused on copper particles that are inexpensive and have migration resistance as compared with silver particles.
  • the bonding with copper nanoparticles requires a high temperature of 300 ° C. for the development of conductivity, and further, the handling and processing may be troublesome due to the small particle size and easy oxidation. Further, sintering of copper particles requires sintering in a reducing atmosphere from the viewpoint of removing a surface oxide film.
  • the present disclosure has been made in view of such circumstances, can be sintered at a low temperature even in a reducing atmosphere, the sintering speed and the degree of sintering between the inside of the joining layer and the fillet portion are uniform, Provided are a method for producing copper particles having good characteristics, a joining paste containing copper particles obtained by the producing method, and a semiconductor device and an electric / electronic component having excellent reliability by using the joining paste.
  • the present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have found that the following disclosure can solve the problems.
  • the present disclosure relates to the following.
  • a step of mixing a copper compound, an amine compound, and a reducing compound in an organic solvent to obtain a copper particle dispersion, and washing the copper particle dispersion obtained in the step with a solvent A method for producing copper particles having a washing step of solid-liquid separation of copper particles from the particle dispersion, A method for producing copper particles, wherein the washing step is performed in a closed system.
  • the copper particle dispersion containing 1 to 50% by mass of the copper particles is supplied to a filtration membrane at a flow rate of 5 to 1500 kg / hr ⁇ m 2 and a pressure of 0.03 to 1.0 MPa.
  • [6] A semiconductor device joined using the joining paste according to the above [5].
  • the present disclosure it is possible to sinter at a low temperature even in a reducing atmosphere, the sintering speed and the degree of sintering between the inside of the joining layer and the fillet portion are uniform, and a method for producing copper particles having good joining characteristics.
  • a bonding paste containing copper particles obtained by a manufacturing method and a semiconductor device and an electric / electronic component having excellent reliability can be provided by using the bonding paste.
  • the method for producing copper particles of the present disclosure includes a step of mixing a copper compound, an amine compound, and a reducing compound in an organic solvent to obtain a copper particle dispersion, and the copper particle dispersion obtained in the step. And a washing step of solid-liquid separation of the copper particles from the copper particle dispersion liquid, wherein the washing step is performed in a closed system.
  • the washing step by performing the washing step in a closed system, oxidation of the surface of the copper particles is controlled, and copper particles having good bonding characteristics can be obtained.
  • a raw material, a copper compound, an amine compound, and a reducing compound are mixed in an organic solvent to obtain a copper particle dispersion.
  • the copper compound used in the present embodiment is not particularly limited as long as it contains a copper atom.
  • Examples of the copper compound include copper carboxylate, copper oxide, copper hydroxide, and copper nitride.
  • the copper compound may be copper carboxylate from the viewpoint of uniformity during the reaction. These may be used alone or in combination of two or more.
  • Copper carboxylate includes copper formate (I), copper acetate (I), copper (I) propionate, copper (I) butyrate, copper (I) valerate, copper (I) caproate, copper (I) caprylate (I) ), Copper (I) caprate, copper (II) formate, copper (II) acetate, copper (II) propionate, copper (II) butyrate, copper (II) valerate, copper (II) caproate, caprylic acid Copper carboxylate anhydrides or hydrates such as copper (II), copper (II) caprate, copper (II) citrate and the like can be mentioned. Copper carboxylate may be copper acetate (II) monohydrate from the viewpoint of productivity and availability. These may be used alone or in combination of two or more.
  • copper carboxylate may be used, or copper carboxylate obtained by synthesis may be used.
  • ⁇ Synthesis of copper carboxylate can be carried out by a known method, for example, it can be obtained by mixing and heating copper (II) hydroxide and a carboxylic acid compound.
  • Examples of copper oxide include copper (II) oxide and copper (I) oxide, and copper (I) oxide may be used from the viewpoint of productivity.
  • Examples of copper hydroxide include copper (II) hydroxide and copper (I) hydroxide. These may be used alone or in combination of two or more.
  • the amine compound used in the present embodiment is not particularly limited as long as it forms a complex with the copper compound.From the viewpoint of sinterability, at least one selected from alkylamines, amino alcohols, alkoxyamines and carboxylic acid amine salts. It may be a compound containing one kind or a carboxylic acid amine salt.
  • the amine compound functions as a reaction medium for the decomposition reaction of the copper compound when the copper compound is decomposed by heating the complex of the copper compound and the amine compound. Further, the amine compound has a function of controlling oxidation by attaching to the surface of copper particles obtained by thermally decomposing the copper compound.
  • the amine compound used in the present embodiment is appropriately selected from known amine compounds according to the conditions of the thermal decomposition of the complex with the copper compound, the properties expected of the produced copper particles, and the like. be able to.
  • the alkylamine is not particularly limited in its structure as long as it is an amine compound having an aliphatic hydrocarbon group such as an alkyl group as a group bonded to an amino group, for example, an alkyl monoamine having one amino group, An alkyl diamine having two amino groups is exemplified.
  • the said alkyl group may have a substituent further.
  • examples of the alkyl monoamine include dipropylamine, butylamine, dibutylamine, hexylamine, cyclohexylamine, heptylamine, octylamine, nonylamine, decylamine, 3-aminopropyltriethoxysilane, dodecylamine, and oleylamine.
  • examples of the diamine include ethylenediamine, N, N-dimethylethylenediamine, N, N′-dimethylethylenediamine, N, N-diethylethylenediamine, N, N′-diethylethylenediamine, 1,3-propanediamine, and 2,2-dimethyl-1.
  • the alkyl monoamine is an alkyl such as a primary amine (R 1 NH 2 ) or a secondary amine (R 2 R 3 NH). It may be a monoamine.
  • the alkylamine does not include an amino alcohol and an alkoxyamine described below.
  • the amino alcohol is not particularly limited in its structure as long as it is an amine compound having a hydroxyl group as a functional group, and examples thereof include an alkanol monoamine having one amino group. Specifically, aminoethanol, heptaminol, isoetalin, propanolamine, sphingosine, 1-amino-2-propanol, 2-aminodibutanol, 2-diethylaminoethanol, 3-diethylamino-1,2-propanediol, 3-dimethyl Amino-1,2-propanediol, 3-methylamino-1,2-propanediol, 3-amino-1,2-propanediol and the like.
  • the alkoxyamine is not particularly limited in its structure as long as it is an amine compound having an alkoxyl group as a substituent, and examples thereof include an alkoxymonoamine having one amino group and an alkoxydiamine having two amino groups.
  • examples thereof include an alkoxymonoamine having one amino group and an alkoxydiamine having two amino groups.
  • methoxyethylamine, 2-ethoxyethylamine, 3-butoxypropylamine and the like are used as alkoxymonoamines, and N-methoxy-1,3-propanediamine and N-methoxy-1,4- are used as alkoxydiamines.
  • the alkoxyamine may be an alkoxymonoamine such as a primary amine (R 1 ONH 2 ) or a secondary amine (R 2 (R 3 O) NH) in consideration of a coordination force to copper generated by reduction.
  • the substituent R 1 of the primary amine described in the above alkylamine and alkoxyamine represents an alkyl group, and may be an alkyl group having 4 to 18 carbon atoms.
  • the substituents R 2 and R 3 of the secondary amine represent an alkyl group, and both may be an alkyl group having 4 to 18 carbon atoms.
  • the substituents R 2 and R 3 may be the same or different.
  • these alkyl groups may have a substituent such as a silyl group and a glycidyl group.
  • the carboxylic acid amine salt can be obtained from a carboxylic acid compound and an amine compound, and a commercially available product may be used, or a product obtained in advance by synthesis may be used.
  • the carboxylic acid amine salt may be formed in-situ by separately charging the carboxylic acid compound and the amine compound into the reaction vessel during the production process of the copper particles.
  • Carboxylic acid amine salts are formed by blending a carboxylic acid compound and an amine compound in an organic solvent in equivalent amounts of functional groups and mixing them under a relatively mild temperature condition of room temperature (25 ° C.) to about 100 ° C. .
  • the amine carboxylate may be removed from the reaction solution containing the product by a distillation method, a recrystallization method, or the like.
  • the carboxylic acid compound forming the carboxylic acid amine salt is not particularly limited as long as it has a carboxy group, and examples thereof include a monocarboxylic acid, a dicarboxylic acid, an aromatic carboxylic acid, and a hydroxy acid. These may be used alone or in combination of two or more.
  • the carboxylic acid compound may be a monocarboxylic acid or a dicarboxylic acid from the viewpoint of reducing the difference in the sintering speed between the inside of the bonding layer and the fillet portion.
  • the carboxylic acid compound constituting the carboxylic acid amine salt may have a thermal decomposition temperature of 200 ° C. or less, or 190 ° C. or less, from the viewpoint of reducing the difference in sintering speed between the inside of the bonding layer and the fillet portion. Or 180 ° C. or lower.
  • those having a boiling point in a region lower than the thermal decomposition temperature may have a boiling point of 280 ° C. or lower, 260 ° C. or lower, and 240 ° C. or lower. C. or lower.
  • the boiling point of the carboxylic acid compound is in this range, the difference in the sintering speed between the inside of the bonding layer and the fillet portion becomes small.
  • monocarboxylic acids include formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, octylic acid, nonanoic acid, capric acid, oleic acid, and stearic acid Acids, isostearic acid and the like. These may be used alone or in combination of two or more.
  • Monocarboxylic acid is formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, octylic acid, nonanoic acid, capric acid, from the viewpoint of reducing the difference in sintering rate between the inside of the bonding layer and the fillet portion.
  • valeric acid, caproic acid, caprylic acid, nonanoic acid and octylic acid is formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, octylic acid, nonanoic acid, capric acid, from the viewpoint of reducing the difference in sintering rate between the inside of the bonding layer and the fillet portion.
  • valeric acid, caproic acid, caprylic acid, nonanoic acid and octylic acid is valeric acid, caproic acid, caprylic acid, nonanoic acid and o
  • examples of the dicarboxylic acid include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, diglycolic acid, and the like. No. These may be used alone or in combination of two or more. From the viewpoint of reducing the difference in sintering speed between the inside of the bonding layer and the fillet portion, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, diglycolic acid may be used, and oxalic acid, malonic acid, succinic acid may be used. An acid or diglycolic acid may be used.
  • examples of the aromatic carboxylic acid include benzoic acid, phthalic acid, isophthalic acid, terephthalic acid, salicylic acid, and gallic acid. These may be used alone or in combination of two or more.
  • the aromatic carboxylic acid may be benzoic acid from the viewpoint of reducing the difference in the sintering speed between the inside of the bonding layer and the fillet portion.
  • examples of the hydroxy acid include glycolic acid, lactic acid, tartronic acid, malic acid, glyceric acid, hydroxybutyric acid, tartaric acid, citric acid, and isocitric acid. These may be used alone or in combination of two or more.
  • the carboxylic acid compound may be glycolic acid, lactic acid, or malic acid from the viewpoint of reducing the difference in the sintering speed between the inside of the bonding layer and the fillet portion.
  • the amine compound constituting the carboxylic acid amine salt is not particularly limited as long as it has a carboxy group, and examples thereof include an alkyl monoamine, an alkyl diamine, and an alkanolamine. These may be used alone or in combination of two or more.
  • the amine compound may be an alkyl monoamine or an alkanolamine from the viewpoint of sinterability.
  • examples of the alkyl monoamine include methylamine, ethylamine, propylamine, butylamine, hexylamine, octylamine, decylamine, dodecylamine and the like. These may be used alone or in combination of two or more.
  • the alkyl monoamine may be hexylamine, octylamine, or decylamine from the viewpoint of sinterability.
  • alkyldiamines include 1,1-methanediamine, 1,2-ethanediamine, 1,3-propanediamine, 1,4-butanediamine, and 1,6-hexane Diamine and 1,8-octanediamine are exemplified. These may be used alone or in combination of two or more.
  • the alkyldiamine may be 1,4-butanediamine or 1,6-hexanediamine from the viewpoint of sinterability.
  • alkanolamines include monoethanolamine, monopropanolamine, monobutanolamine, 2- (2-aminoethylamino) ethanol, 2- (2-aminoethoxy) ethanol, Examples thereof include 1-amino-2-propanol, 2-amino-1-propanol, and 3-amino-1,2-propanediol. These may be used alone or in combination of two or more.
  • the alkanolamines may be monoethanolamine, monopropanolamine, monobutanolamine, 1-amino-2-propanol, or 2-amino-1-propanol from the viewpoint of sinterability.
  • the boiling point of the amino compound may be 70 ° C to 280 ° C, 100 ° C to 260 ° C, or 120 ° C to 240 ° C. If the boiling point of the amino compound is in the above range, the obtained copper particles show good sinterability. Further, when the boiling point of the amino compound is 70 ° C. or more, the obtained paste for joining is controlled in volatilization of the amino compound in the heating step, so that uniformity in the system is maintained. When the boiling point of the amino compound is 280 ° C. or lower, the amino compound is easily removed at the time of sintering the joining paste, and thus low-temperature sinterability is exhibited. Furthermore, the boiling point of the amino compound may be higher than the heating temperature in the heating step and lower than the sintering temperature in use.
  • the reducing compound used in the present embodiment is not particularly limited as long as it has a reducing power for reducing a copper compound and releasing metallic copper.
  • the reducing compound may have a boiling point of 70 ° C. or higher, or a heating temperature of the heating step or higher.
  • the reducing compound may be a compound that is dissolved in an organic solvent described below composed of carbon, hydrogen and oxygen.
  • Such a reducing compound typically includes a hydrazine derivative.
  • the hydrazine derivative include hydrazine monohydrate, methylhydrazine, ethylhydrazine, n-propylhydrazine, i-propylhydrazine, n-butylhydrazine, i- Butylhydrazine, sec-butylhydrazine, t-butylhydrazine, n-pentylhydrazine, i-pentylhydrazine, neo-pentylhydrazine, t-pentylhydrazine, n-hexylhydrazine, i-hexylhydrazine, n-heptylhydrazine, n- Octylhydrazine, n-nonylhydrazine, n-decylhydrazine, n-undecylhydrazine, n-
  • the method for producing copper particles of the present embodiment may further include the following compound.
  • (Carboxylic acid having 1 to 12 carbon atoms) A carboxylic acid having 1 to 12 carbon atoms is used for controlling the particle size of the obtained copper particles.
  • the carboxylic acid is not particularly limited as long as it has a carboxyl group.
  • monocarboxylic acids such as formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, octylic acid, nonanoic acid, capric acid, oleic acid, stearic acid, and isostearic acid; oxalic acid, malonic acid, and succinic acid
  • Dicarboxylic acids such as acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, and diglycolic acid; aromatic carboxylic acids such as benzoic acid, phthalic acid, isophthalic acid, terephthalic acid, salicylic acid, and gallic acid
  • a hydroxy acid such as glycolic acid, lactic acid, tartronic acid, malic acid, glyceric acid, hydroxybutyric acid, tartaric acid, citric acid, and isocitric acid; From the viewpoint of easy particle size control, formic acid
  • Organic solvent used in the present embodiment can be used without any particular limitation as long as it can be used as a reaction solvent that does not inhibit the properties of a complex or the like generated from a mixture obtained by mixing the above-described raw materials.
  • the organic solvent may be an alcohol that is compatible with the above-mentioned reducing compound.
  • the organic solvent may be an organic solvent that does not volatilize during the reduction reaction.
  • the bonding paste containing such an organic solvent can stably control the formation of copper ions by the decomposition of the copper compound-amine complex and the precipitation of metallic copper by the reduction of the generated copper ions. Thereby, the particle size of the generated copper particles is stabilized. Therefore, the organic solvent may have a boiling point of 70 ° C. or higher. Further, the organic solvent may be composed of carbon, hydrogen and oxygen.
  • Examples of the alcohol used as the organic solvent include 1-propanol, 2-propanol, butanol, pentanol, hexanol, heptanol, octanol, ethylene glycol, 1,3-propanediol, 1,2-propanediol, butyl carbitol, Butyl carbitol acetate, ethyl carbitol, ethyl carbitol acetate, diethylene glycol diethyl ether, butyl cellosolve and the like. These may be used alone or in combination of two or more.
  • an organic solvent is contained in a reaction vessel, and in the organic solvent, a copper compound, an amine compound, and a reducing compound, which are the above-described raw material compounds, are mixed. .
  • the order of mixing these compounds is not particularly limited, and the above compounds may be mixed in any order.
  • the copper compound and the amine compound are first mixed, mixed at 0 to 110 ° C. for about 5 to 30 minutes, and further reduced.
  • the active compound may be added and mixed.
  • each compound may be used in an amount of 0.1 to 10 mol of the amine compound and 0.5 to 5 mol of the reducing compound, or 1 to 10 mol of the amine compound and 1 to 10 mol of the reducing compound, based on 1 mol of the copper compound. It may be 3 mol.
  • the organic solvent may be used in such an amount that each component can sufficiently react. For example, about 50 to 2000 mL may be used.
  • the mixture obtained by mixing the above is heated sufficiently to cause the reduction reaction of the copper compound to proceed. By this heating, unreacted copper compounds can be eliminated, and metallic copper can be deposited and grown to form copper particles.
  • the amine compound adheres to the surface of the copper particles and has an action of controlling the growth to prevent the particles from becoming coarse.
  • the heating temperature of the above mixture may be any temperature at which the copper compound is thermally decomposed and reduced to produce copper particles.
  • the heating temperature may be 70 to 150 ° C, or may be 80 to 120 ° C. Further, the heating temperature may be lower than the boiling points of the raw material compound and the organic solvent. When the heating temperature is within the above range, copper particles can be efficiently generated. Furthermore, the volatilization of these volatile components is controlled by using a carboxylic acid in addition to the amine compound.
  • a copper particle dispersion can be obtained.
  • the concentration of copper particles contained in the copper particle dispersion is adjusted to 1 to 50% by mass by adding a cleaning solvent described below to the obtained copper particle dispersion. May be.
  • the copper particle dispersion obtained in the above step is solvent-washed in a closed system, and copper particles are solid-liquid separated from the copper particle dispersion.
  • the separation operation such as centrifugation generally used in the production of silver fine particles
  • the solvent cannot be continuously replaced, and the stirring operation with the cleaning solvent is performed in the atmosphere.
  • the synthesized copper particles are easily oxidized on the surface of the particles, and the oxygen caught in the copper particle dispersion liquid particularly when stirred with a cleaning solvent in the air comes into contact with the synthesized copper particles. As a result, oxidation of the copper particle surface may proceed.
  • the surface oxidation of the copper particles can be reduced by washing the copper particle dispersion with a solvent in a closed system.
  • the present cleaning step may be a continuous solvent replacement and cleaning method.
  • a specific solvent replacement washing method is performed under the conditions of a flow rate of 5 to 1500 kg / hr ⁇ m 2 and a pressure of 0.03 to 1.0 MPa without reslurrying the copper particle dispersion containing 1 to 50% by mass of copper particles.
  • the solvent is supplied to the filtration membrane, and the washing solvent is continuously supplied to the filtration membrane under the above conditions.
  • the copper particles obtained by the method for producing copper particles of the present embodiment are supplied with a cleaning solvent to the copper particle dispersion at a flow rate of 5 to 1500 kg / hr ⁇ m 2 and applied at a flow rate of 0.03 to 1.0 MPa.
  • the flow rate may be 10 to 1000 kg / hr ⁇ m 2 , 15 to 500 kg / hr ⁇ m 2 , or 20 to 200 kg / hr ⁇ m 2. Is also good.
  • the pressure may be 0.1 to 0.8 MPa, or may be 0.2 to 0.6 MPa.
  • the solvent replacement and washing may be further performed after drying under reduced pressure, centrifugation, and the like, which will be described later.
  • the washing solvent can be used without any particular limitation as long as it does not damage the protective group of the produced copper particles.
  • Specific examples include water; alcohols such as ethanol and methanol; glycols such as diethylene glycol; and other solvents.
  • the washing solvent may be supplied in an amount of 3 to 7 times the volume of the filtration chamber.
  • the solvent replacement device is not particularly limited as long as the solvent can be sealed and the solvent can be washed.
  • a rotary membrane separation device may be used, and specific examples thereof include a horizontal filter plate type filter (manufactured by Mitsubishi Kakoki Co., Ltd.). Copper particles can be obtained by performing, for example, drying under reduced pressure, centrifugal separation, and the like on the solids separated by filtration.
  • Copper particles obtained by the method for producing copper particles of the present embodiment the copper compound is reduced by the reducing compound in the amine compound, the eluted copper atoms aggregate, nucleation, nucleus growth, coated with the amine compound It is presumed that copper particles were formed. Therefore, by appropriately selecting the type of the copper compound, the amine compound, and the reducing compound to be used, and the reaction temperature, the supply rate of the copper atom or the adsorption ability by the amine compound is changed, so that copper particles of any shape and size can be obtained. Obtainable.
  • the copper particles obtained by the method for producing copper particles of the present embodiment can be fired at a low temperature of less than 300 ° C.
  • the joining paste using this has no difference in the sintering speed and the degree of sintering between the inside of the joining layer and the fillet portion, and a joining layer with high joining reliability can be obtained.
  • the average particle diameter of the copper particles may be 1 to 1000 nm, 20 to 800 nm, or 30 to 500 nm from the viewpoint of the denseness of the bonding layer.
  • the average particle diameter of the copper particles was determined based on an observation image of a scanning electron microscope (for example, trade name: JSM-7600F; SEM, manufactured by JEOL Ltd.). Calculated as the average value of 10). Note that the average value is an arithmetic average value, and 10 or more copper particles may be used in the calculation.
  • the bonding paste of the present embodiment contains copper particles obtained by the above-described method for producing copper particles.
  • the joining paste of the present embodiment can be joined without pressure and has excellent adhesiveness.
  • the bonding paste of the present embodiment has a uniform sintering speed and sintering degree between the inside of the bonding layer and the fillet portion, and has good bonding characteristics. Therefore, the bonding paste of this embodiment can be used as a die attach paste for bonding elements or a material for bonding heat dissipation members.
  • the joining paste of the present embodiment may use two or more copper particles having different average particle diameters in combination.
  • the average particle diameter of the second copper particles having a larger average particle diameter than the first copper particles may be about 2 to 10 times the average particle diameter of the first copper particles.
  • the amount of the second copper particles may be about 1.5 to 10 times the amount of the first copper particles.
  • the bonding paste of the present embodiment may include large-diameter copper particles having a larger particle size than the above-described copper particles, a thermosetting resin, an organic solvent, and other additives. Thereby, the influence of the sintering shrinkage of the copper particles can be reduced, and a more reliable bonding layer can be formed.
  • the large-diameter copper particles may have an average particle diameter of more than 1 ⁇ m and 30 ⁇ m or less, or 2 to 20 ⁇ m.
  • the shape is not particularly limited, and spheres, plates, flakes, scales, dendrites, rods, wires, and the like can be used.
  • the average particle diameter of the large-diameter copper particles can be measured using a laser diffraction / scattering particle size distribution analyzer or the like.
  • the large-sized copper particles may be treated with a lubricant and a rust preventive.
  • a typical example of such a treatment is a treatment with a carboxylic acid compound.
  • the carboxylic acid compound include formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, octylic acid, nonanoic acid, capric acid, palmitic acid, oleic acid, stearic acid, isostearic acid, oxalic acid, Malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, diglycolic acid, benzoic acid, phthalic acid, isophthalic acid, terephthalic acid, salicylic acid, gallic acid, glycolic acid, lactic acid, Examples thereof include tartronic acid, malic acid, glyceric acid, hydroxybutyric acid, tart
  • carboxylic acid compounds include formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, octylic acid, nonanoic acid, capric acid, palmitic acid, oleic acid, and stearic acid. It may be an acid, isostearic acid, oxalic acid, malonic acid, succinic acid, glutaric acid.
  • the carboxylic acid compound may be caproic acid, caprylic acid, octylic acid, nonanoic acid, capric acid, malonic acid, succinic acid, or glutaric acid from the viewpoint of the dispersibility and oxidation resistance of the copper particles.
  • thermosetting resin can be used without particular limitation as long as it is a thermosetting resin generally used as an adhesive.
  • the thermosetting resin may be a liquid resin or a resin that is liquid at room temperature (25 ° C.).
  • examples of the thermosetting resin include a cyanate resin, an epoxy resin, a radically polymerizable acrylic resin, and a maleimide resin. These may be used alone or in combination of two or more.
  • an adhesive material (paste) having an appropriate viscosity can be obtained.
  • the joining paste of the present embodiment contains a thermosetting resin, the temperature of the joining paste rises due to the reaction heat at the time of curing, thereby promoting the sinterability of the copper particles.
  • Cyanate resin is a compound having a —NCO group in a molecule, and is a resin that forms a three-dimensional network structure and is cured by a reaction of the —NCO group by heating.
  • Specific examples include 1,3-dicyanatobenzene, 1,4-dicyanatobenzene, 1,3,5-tricyanatobenzene, 1,3-dicyanatonaphthalene, 1,4-dicyanatonaphthalene, 6-dicyanatonaphthalene, 1,8-dicyanatonaphthalene, 2,6-dicyanatonaphthalene, 2,7-dicyanatonaphthalene, 1,3,6-tricyanatonaphthalene, 4,4′-dicyanatobiphenyl, bis (4-cyanatophenyl) methane, bis (3,5-dimethyl-4-cyanatophenyl) methane, 2,2-bis (4-cyanatophenyl) propane, 2,2-bis (3,5-dibromo -4-cyanatopheny
  • cyanate resin a prepolymer having a triazine ring formed by trimerizing the cyanate group of the polyfunctional cyanate resin can also be used.
  • the prepolymer is obtained by polymerizing the above polyfunctional cyanate resin monomer with, for example, a mineral acid, an acid such as a Lewis acid, a base such as sodium alcoholate, a tertiary amine, or a salt such as sodium carbonate as a catalyst. can get.
  • curing accelerator for the cyanate resin generally known curing accelerators can be used.
  • organometallic complexes such as zinc octylate, tin octylate, cobalt naphthenate, zinc naphthenate, and iron acetylacetone; metal salts such as aluminum chloride, tin chloride and zinc chloride; and amines such as triethylamine and dimethylbenzylamine.
  • organometallic complexes such as zinc octylate, tin octylate, cobalt naphthenate, zinc naphthenate, and iron acetylacetone
  • metal salts such as aluminum chloride, tin chloride and zinc chloride
  • amines such as triethylamine and dimethylbenzylamine.
  • curing accelerators can be used alone or in combination of two or more.
  • Epoxy resin is a compound having one or more glycidyl groups in a molecule, and is a resin that forms a three-dimensional network structure by being reacted with glycidyl groups by heating, and is cured. Two or more glycidyl groups may be contained in one molecule. This is because the glycidyl group cannot exhibit sufficient cured product characteristics even when reacted with only one compound.
  • a compound containing two or more glycidyl groups in one molecule can be obtained by epoxidizing a compound having two or more hydroxyl groups.
  • Such compounds include bisphenol compounds such as bisphenol A, bisphenol F, and biphenol or derivatives thereof, and alicyclic rings such as hydrogenated bisphenol A, hydrogenated bisphenol F, hydrogenated biphenol, cyclohexanediol, cyclohexanedimethanol, and cyclohexanediethanol.
  • the epoxy resin is a paste at room temperature (25 ° C.) as a bonding paste, it may be liquid alone or at room temperature (25 ° C.) as a mixture. It is also possible to use reactive diluents as usual. Examples of the reactive diluent include monofunctional aromatic glycidyl ethers such as phenyl glycidyl ether and cresyl glycidyl ether, and aliphatic glycidyl ethers.
  • a curing agent is used to cure the epoxy resin.
  • the curing agent for the epoxy resin include an aliphatic amine, an aromatic amine, dicyandiamide, a dihydrazide compound, an acid anhydride, and a phenol resin.
  • dihydrazide compound examples include carboxylic acid dihydrazides such as adipic dihydrazide, dodecanoic dihydrazide, isophthalic dihydrazide, and p-oxybenzoic dihydrazide.
  • the acid anhydrides include phthalic anhydride, tetrahydrophthalic anhydride, Examples include phthalic anhydride, endomethylenetetrahydrophthalic anhydride, dodecenylsuccinic anhydride, a reaction product of maleic anhydride and polybutadiene, and a copolymer of maleic anhydride and styrene.
  • a curing accelerator can be blended to promote curing.
  • curing accelerators for epoxy resins include imidazoles, triphenylphosphine or tetraphenylphosphine and salts thereof, amine compounds such as diazabicycloundecene, and the like. And salts thereof.
  • Curing accelerators include 2-methylimidazole, 2-ethylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2-phenyl-4,5 Imidazole compounds such as -dihydroxymethylimidazole, 2-C 11 H 23 -imidazole, and adducts of 2-methylimidazole with 2,4-diamino-6-vinyltriazine.
  • the curing accelerator may be an imidazole compound having a melting point of 180 ° C. or higher.
  • a radically polymerizable acrylic resin is a compound having a (meth) acryloyl group in the molecule, and is a resin that forms a three-dimensional network structure by the reaction of the (meth) acryloyl group and is cured.
  • One or more (meth) acryloyl groups may be contained in the molecule.
  • acrylic resin for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 3-hydroxybutyl (Meth) acrylate, 4-hydroxybutyl (meth) acrylate, 1,2-cyclohexanediol mono (meth) acrylate, 1,3-cyclohexanediol mono (meth) acrylate, 1,4-cyclohexanediol mono (meth) acrylate, 1,2-cyclohexanedimethanol mono (meth) acrylate, 1,3-cyclohexanedimethanol mono (meth) acrylate, 1,4-cyclohexanedimethanol mono (meth) acrylate, 1,2-cyclohexane Ethanol mono (meth) acrylate, 1,3-cyclohexanediethanol mono (meth)
  • dicarboxylic acids that can be used here include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, maleic acid, fumaric acid, phthalic acid, and tetrahydrophthalic acid. , Hexahydrophthalic acid and derivatives thereof.
  • acrylic resin polyethers, polyesters, polycarbonates having a molecular weight of 100 to 10,000, a compound having a (meth) acryl group as a poly (meth) acrylate, a (meth) acrylate having a hydroxyl group, and having a hydroxyl group ( (Meth) acrylamide and the like.
  • Maleimide resin is a compound containing one or more maleimide groups in one molecule, and is a resin that forms a three-dimensional network structure and reacts when the maleimide groups react by heating.
  • the maleimide resin is a compound obtained by reacting a dimer acid diamine with maleic anhydride, or a compound obtained by reacting a maleimidated amino acid such as maleimide acetic acid or maleimidocaproic acid with a polyol.
  • a maleimidated amino acid is obtained by reacting maleic anhydride with aminoacetic acid or aminocaproic acid.
  • the polyol may be a polyether polyol, a polyester polyol, a polycarbonate polyol, a poly (meth) acrylate polyol, or may not contain an aromatic ring.
  • thermosetting resin when blended, it is blended so as to be 1 to 20 parts by mass when the total amount of the copper particles and the large-diameter copper particles is 100 parts by mass.
  • the amount of the thermosetting resin is 1 part by mass or more, the adhesive effect by the thermosetting resin can be sufficiently obtained, and when the amount of the thermosetting resin is 20 parts by mass or less, high heat can be obtained without lowering the proportion of the copper component. Conductivity can be sufficiently ensured, and heat dissipation can be improved.
  • the organic component is not excessively increased, and deterioration due to light and heat is suppressed. As a result, the life of the light emitting device can be increased. By setting the content within such a range, the contact between the copper particles and / or the large-diameter copper particles is reduced by utilizing the adhesive performance of the thermosetting resin, and the mechanical strength of the entire adhesive layer is maintained. Can be easily done.
  • Organic solvent a known solvent can be used as long as it functions as a reducing agent.
  • the organic solvent may be an alcohol, such as an aliphatic polyhydric alcohol.
  • examples of the aliphatic polyhydric alcohol include glycols such as ethylene glycol, diethylene glycol, propylene glycol, diprovylene glycol, 1,4-butanediol, glycerin, and polyethylene glycol. These organic solvents may be used alone or in combination of two or more.
  • Alcohol becomes high temperature by heat treatment at the time of paste curing (sintering) and increases reducing power.
  • the copper oxide partially present in the copper particles and the metal oxide (eg, copper oxide) on the metal substrate are reduced by the alcohol to become a pure metal.
  • the bonding paste forms a cured film that is denser, has higher conductivity, and has higher adhesion to the substrate.
  • the alcohol is partially refluxed during the heat treatment during paste curing (paste curing temperature higher than the boiling point), and the metal oxide is reduced more efficiently.
  • the boiling point of the organic solvent may be 100 to 300 ° C. or 150 to 290 ° C.
  • the volatility does not become too high even at room temperature, and a reduction in the reducing ability due to the volatilization of the dispersion medium can be controlled, so that stable adhesive strength can be obtained.
  • the boiling point is 300 ° C. or less, sintering of the cured film (conductive film) is likely to occur, and a film having excellent denseness can be formed.
  • the compounding amount may be 7 to 20 parts by mass when the total amount of the copper particles and the large-diameter copper particles is 100 parts by mass.
  • the amount is 7 parts by mass or more, the viscosity does not become too high, and the workability can be improved.
  • the amount is 20 parts by mass or less, the decrease in viscosity is controlled, the sedimentation of copper in the paste is controlled, and the reliability is increased. be able to.
  • a curing accelerator in addition to the above components, a curing accelerator, a rubber, a low-stressing agent such as silicone, a coupling agent, a defoaming agent, which are generally blended with this type of composition, Surfactants, colorants (pigments, dyes), various polymerization inhibitors, antioxidants, solvents, and other various additives can be added as necessary. Each of these additives may be used alone or in combination of two or more.
  • the bonding paste of the present embodiment is obtained by sufficiently mixing the above-described copper particles, and, if necessary, additives such as large-diameter copper particles, a thermosetting resin, an organic solvent, and a coupling agent. Further, it can be prepared by performing a kneading treatment with a disperser, a kneader, a three-roll mill or the like, and then defoaming.
  • the viscosity of the bonding paste of the present embodiment may be, for example, 20 to 300 Pa ⁇ s or 40 to 200 Pa ⁇ s. Further, the bonding strength of the bonding paste of the present embodiment may be 25 MPa or more, or may be 30 MPa or more. The viscosity and the bonding strength can be measured by the methods described in Examples.
  • the bonding paste of the present embodiment obtained in this manner is excellent in high thermal conductivity and heat dissipation. Therefore, when used as a bonding material for the element or the heat dissipating member to the substrate or the like, the heat dissipation inside the device to the outside is improved, and the product characteristics can be stabilized.
  • the semiconductor device of the present embodiment is one in which a semiconductor element is adhered to a substrate serving as an element supporting member using the above-mentioned bonding paste. That is, the bonding paste is used here as a die attach paste, and the semiconductor element and the substrate are bonded and fixed via the paste.
  • the semiconductor element may be any known semiconductor element, and examples include a transistor and a diode. Furthermore, as this semiconductor element, a light emitting element such as an LED is cited.
  • the type of the light-emitting element is not particularly limited, and examples thereof include a light-emitting element in which a nitride semiconductor such as InN, AlN, GaN, InGaN, AlGaN, and InGaAlN is formed as a light-emitting layer on a substrate by MOBVC or the like.
  • the element supporting member include a supporting member formed of a material such as copper, copper-plated copper, PPF (pre-plating lead frame), glass epoxy, and ceramics.
  • the joining paste of the present embodiment can join a base material that has not been subjected to metal plating.
  • the connection reliability with respect to the temperature cycle after mounting is dramatically improved as compared with the related art.
  • the electric resistance value is sufficiently small and the change with time is small, there is an advantage that the output does not decrease with time even when driven for a long time and the life is long.
  • the electric / electronic component of the present embodiment is obtained by bonding a heat radiating member to a heat generating member by using the above-mentioned bonding paste. That is, the bonding paste is used as a material for bonding the heat radiating member, and the heat radiating member and the heat generating member are bonded and fixed via the bonding paste.
  • the heat generating member may be the above-described semiconductor element or a member having the semiconductor element, or may be another heat generating member.
  • Examples of the heat generating member other than the semiconductor element include an optical pickup and a power transistor.
  • examples of the heat radiating member include a heat sink and a heat spreader.
  • the heat-generating member and the heat-dissipating member may be directly bonded via a bonding paste, or may be indirectly bonded with another member having high thermal conductivity interposed therebetween.
  • hydrazine monohydrate (trade name: hydrazine monohydrate, manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.) was added to 500 mL of 1-propanol as a reducing compound. ) The solution in which 3 mol was dissolved was dropped into the copper precursor solution, and the mixture was stirred for 30 minutes. The temperature was raised again to 90 ° C., and the mixture was heated and stirred for 2 hours, and then cooled to room temperature (25 ° C.) to obtain a copper particle dispersion containing 2% by mass of copper particles.
  • the above-mentioned copper particle dispersion is supplied to a sealed filtration membrane of DyF152 / s (trade name, horizontal filter plate type filter, manufactured by Mitsubishi Kakoki Co., Ltd.) at a flow rate of 20 kg / hr ⁇ m 2 and a pressure of 0.1 MPa, Further, 1000 mL of ethanol was continuously supplied to obtain a copper particle concentrated solution in which solvent was replaced with ethanol.
  • a DyF152 / s 1000 mL of diethylene glycol (manufactured by Tokyo Kasei Kogyo Co., Ltd.) was continuously supplied from the copper particle concentrated solution with the solvent replaced with ethanol, and the solvent was replaced with diethylene glycol, followed by centrifugation (4000 rpm).
  • a copper particle concentrate having an average particle diameter of 50 nm was obtained.
  • Example 1 100 parts by mass of the copper particles obtained in Synthesis Example 1 and 15 parts by mass of diethylene glycol (produced by Tokyo Chemical Industry Co., Ltd.) as an organic solvent were prepared and kneaded with a roll to obtain a bonding paste.
  • the obtained joining paste was evaluated by the following method. The results are shown in Table 1.
  • the joining paste was applied to a glass substrate (1 mm in thickness) by screen printing so as to have a thickness of 25 ⁇ m, and was cured at 200 ° C. for 60 minutes.
  • the electrical resistance of the obtained sintered film was measured by a four-point needle method using Loresta GP (trade name, manufactured by Mitsubishi Chemical Analytic).
  • a silicon chip provided with a gold vapor deposition layer on a bonding surface of 2 mm ⁇ 2 mm was mounted on a solid copper frame and a PPF (Ni-Pd / Au-plated copper frame) using a bonding paste, and nitrogen (3% hydrogen) was used.
  • the composition was cured at 200 ° C. for 60 minutes in an atmosphere. After the curing and after the moisture absorption treatment (85 ° C., relative humidity 85%, 72 hours), the die shear strength at room temperature (25 ° C.) was measured for each using DAGE 4000Plus (product name, manufactured by Nordson Corporation).
  • a silicon chip having a bonding surface of 2 mm ⁇ 2 mm provided with a gold vapor deposition layer was mounted on a copper frame and a PPF using a bonding paste and cured at 200 ° C. for 60 minutes in a nitrogen (3% hydrogen) atmosphere.
  • an epoxy sealing material (trade name: KE-G3000D) manufactured by Kyocera Corporation, a package molded under the following conditions was subjected to a moisture absorption treatment at 85 ° C. and a relative humidity of 85% for 168 hours, and then an IR reflow treatment ( 260 ° C., 10 seconds) and a cooling / heating cycle treatment (the operation of raising the temperature from ⁇ 55 ° C. to 150 ° C.
  • the bonding paste containing copper particles obtained by the method for producing copper particles of the present disclosure in which the washing step is performed in a closed system has high sinterability in both the coating film state and the bonding state. Moreover, it turned out that the joining paste containing copper particles obtained by the method for producing copper particles of the present disclosure has high joining reliability. Therefore, by using the bonding paste, a semiconductor device and an electric / electronic device having excellent reliability can be obtained.

Abstract

Provided is a production method for copper particles having: a step for mixing a copper compound, an amine compound, and a reducing compound in an organic solvent and obtaining a copper particle dispersion; and a cleaning step for subjecting the copper particle dispersion obtained in the aforementioned step to solvent cleaning and separating copper particles from the copper particle dispersion by a solid-liquid separation process, wherein the cleaning step is carried out in a closed system.

Description

銅粒子の製造方法、接合用ペーストおよび半導体装置並びに電気・電子部品Method for producing copper particles, bonding paste, semiconductor device, and electric / electronic component
　本開示は、銅粒子の製造方法、接合用ペーストおよび該接合用ペーストを使用して製造した半導体装置並びに電気・電子部品に関する。 (4) The present disclosure relates to a method for producing copper particles, a joining paste, a semiconductor device manufactured using the joining paste, and an electric / electronic component.
　半導体製品の大容量、高速処理化及び微細配線化に伴い、半導体製品作動中に発生する熱の処理が注目されてきている。特に、半導体製品から熱を逃がす、いわゆるサーマルマネージメントが要求されている。このため半導体製品にヒートスプレッダー、ヒートシンクなどの放熱部材を取り付ける方法などが一般的に採用されている。また、半導体製品に放熱部材を接着する材料自体の熱伝導率はより高いものが望まれてきている。
　また、半導体製品の形態によっては、サーマルマネージメントをより効率的なものとするため、半導体素子そのもの又は半導体素子を接着したリードフレームのダイパッド部にヒートスプレッダーを接着する方法及びダイパッド部をパッケージ表面に露出させることにより放熱板としての機能を持たせる方法（例えば、特許文献１参照）などが採用されている。 2. Description of the Related Art With the increase in capacity, high-speed processing, and fine wiring of semiconductor products, attention has been paid to the treatment of heat generated during operation of semiconductor products. In particular, there is a demand for so-called thermal management for releasing heat from semiconductor products. For this reason, a method of attaching a heat radiating member such as a heat spreader or a heat sink to a semiconductor product is generally adopted. Further, a material having a higher thermal conductivity of a material for bonding a heat dissipation member to a semiconductor product has been desired.
Also, depending on the form of the semiconductor product, in order to make thermal management more efficient, a method of bonding a heat spreader to the die pad portion of the semiconductor device itself or a lead frame to which the semiconductor device is bonded, and exposing the die pad portion to the package surface In this case, a method of giving a function as a heat radiating plate (for example, see Patent Document 1) is adopted.
　また、さらには半導体素子をサーマルビアなどの放熱機構を有する有機基板などに接着する場合もある。この場合も半導体素子を接着する材料に高熱伝導性が要求される。また、近年の白色発光ＬＥＤの高輝度化により、フルカラー液晶画面のバックライト照明、シーリングライト、ダウンライト等の照明装置にも広く用いられるようになっている。ところで、発光素子の高出力化による高電流投入により、発光素子と基板とを接着する接着剤が熱及び光等により変色、または電気抵抗値の経時変化が発生するおそれがあった。とりわけ発光素子と基板との接合を接着剤の接着力に完全に頼る方法では、電子部品のはんだ実装時に接合材料がはんだ溶融温度下に接着力を失うことで剥離するおそれがあり、不灯に至る懸念があった。また、白色発光ＬＥＤの高性能化は、発光素子チップの発熱量の増大を招くこととなり、これに伴いＬＥＤの構造及びそれに使用する部材にも放熱性の向上が求められている。 半導体 Furthermore, the semiconductor element may be bonded to an organic substrate having a heat dissipation mechanism such as a thermal via. Also in this case, the material for bonding the semiconductor element needs to have high thermal conductivity. Further, with the recent increase in luminance of white light emitting LEDs, they have been widely used for lighting devices such as backlighting, ceiling lights, and downlights of full color liquid crystal screens. By the way, when the high current is applied by increasing the output of the light emitting element, the adhesive for bonding the light emitting element and the substrate may be discolored by heat and light, or the electric resistance value may change with time. In particular, in a method in which the bonding between the light emitting element and the substrate is completely dependent on the adhesive strength of the adhesive, the bonding material may lose its adhesive strength at the solder melting temperature at the time of soldering the electronic component, and may be peeled off. There were concerns. Further, higher performance of the white light emitting LED causes an increase in the amount of heat generated by the light emitting element chip, and accordingly, the structure of the LED and members used therein are required to have improved heat radiation.
　特に、近年、電力損失の少ない炭化ケイ素（ＳｉＣ）、窒化ガリウムのようなワイドバンドギャップ半導体を使用するパワー半導体装置の開発が盛んとなり、素子自身の耐熱性が高く、大電流による２５０℃以上の高温動作が可能となっている。しかし、その特性を発揮するためには、動作発熱を効率的に放熱する必要があり、導電性及び伝熱性に加え、長期高温耐熱性に優れた接合材料が求められている。 In particular, in recent years, power semiconductor devices using wide band gap semiconductors such as silicon carbide (SiC) and gallium nitride with low power loss have been actively developed, and the heat resistance of the element itself is high, and the temperature is higher than 250 ° C. due to a large current. High temperature operation is possible. However, in order to exhibit such characteristics, it is necessary to efficiently dissipate the heat generated during operation. Therefore, a bonding material having excellent long-term high-temperature heat resistance in addition to conductivity and heat conductivity is required.
　このように半導体装置及び電気・電子部品の各部材の接着に用いられる材料（ダイアタッチペースト及び放熱部材接着用材料等）に高い熱伝導性が要求されている。また、これらの材料は、同時に製品の基板搭載時のリフロー処理に耐える必要もあり、さらには大面積の接着が要求される場合も多く、構成部材間の熱膨張係数の違いによる反りなどの発生率を小さくするための低応力性も併せ持つ必要がある。 材料 As described above, high thermal conductivity is required for materials (such as a die attach paste and a material for bonding a heat radiating member) used for bonding each member of a semiconductor device and an electric / electronic component. In addition, these materials also need to withstand reflow processing at the same time when the product is mounted on the substrate, and in many cases, a large area of adhesion is required. It is necessary to also have low stress properties for reducing the rate.
　ここで、通常、高熱伝導性を有する接着剤を得るには、銀粉、銅粉などの金属フィラー及び窒化アルミニウム、窒化ボロンなどのセラミック系フィラーなどを充填剤として有機系のバインダーに高い含有率で分散させる必要がある（例えば、特許文献２参照）。 Here, usually, in order to obtain an adhesive having high thermal conductivity, a metal filler such as silver powder and copper powder and a ceramic filler such as aluminum nitride and boron nitride are used as fillers at a high content in an organic binder. It is necessary to disperse (for example, see Patent Document 2).
　ところが、昨今、そうした要求に耐えうる接合方法の候補として、バルク体の銀よりも低温の条件下で接合を可能とする、銀ナノ粒子による接合方法が着目されるようになってきた（例えば、特許文献３参照）。
　ところで、銀粒子は導電性に優れているが、価格が高いこと及び耐マイグレーション性を考慮して、他の金属への代替が検討されている。そこで、現在、銀粒子と比較して安価で、マイグレーション耐性のある銅粒子に注目が集まっている。 However, recently, as a candidate for a bonding method that can withstand such a demand, a bonding method using silver nanoparticles that enables bonding at a lower temperature than silver in a bulk body has been attracting attention (for example, Patent Document 3).
By the way, silver particles are excellent in conductivity, but in consideration of high price and migration resistance, substitution with other metals is being studied. Therefore, attention is now focused on copper particles that are inexpensive and have migration resistance as compared with silver particles.
特開２００６－０８６２７３号公報JP 2006-086273 A 特開２００５－１１３０５９号公報JP 2005-113059 A 特開２０１１－２４０４０６号公報JP 2011-240406 A
　しかしながら、銅ナノ粒子による接合は、導電性の発現に、３００℃という高温が必要なこと、さらには粒子径が小さく、酸化し易いこと、などから取扱い及び処理に手間がかかる場合がある。さらに、銅粒子の焼結には表面酸化膜の除去の観点から、還元雰囲気での焼結を必要としていた。 However, the bonding with copper nanoparticles requires a high temperature of 300 ° C. for the development of conductivity, and further, the handling and processing may be troublesome due to the small particle size and easy oxidation. Further, sintering of copper particles requires sintering in a reducing atmosphere from the viewpoint of removing a surface oxide film.
　また、特に研究開発が進んでいる配線用銅ナノ粒子は比較的低温焼結が可能であるものの、接合用に使用した場合、接合層内部とフィレット部とに焼結速度および焼結度に差が発生し、信頼性の高い接合体を得ることが難しかった。 In addition, although copper nanoparticles for wiring, for which research and development are particularly advanced, can be sintered at a relatively low temperature, when used for bonding, there is a difference in the sintering speed and degree of sintering between the inside of the bonding layer and the fillet. Occurred, and it was difficult to obtain a highly reliable bonded body.
　本開示は、このような実情に鑑みてなされたものであり、還元雰囲気でなくとも低温焼結可能であり、接合層内部とフィレット部との焼結速度および焼結度が均一であり、接合特性が良好な銅粒子の製造方法、該製造方法によって得られる銅粒子を含む接合用ペースト並びに該接合用ペーストを使用することで信頼性に優れた半導体装置及び電気・電子部品を提供する。 The present disclosure has been made in view of such circumstances, can be sintered at a low temperature even in a reducing atmosphere, the sintering speed and the degree of sintering between the inside of the joining layer and the fillet portion are uniform, Provided are a method for producing copper particles having good characteristics, a joining paste containing copper particles obtained by the producing method, and a semiconductor device and an electric / electronic component having excellent reliability by using the joining paste.
　本発明者らは、上記の課題を解決するべく鋭意検討した結果、下記の開示により該課題を解決できることを見出した。 The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have found that the following disclosure can solve the problems.
　すなわち、本願開示は、以下に関する。
［１］銅化合物と、アミン化合物と、還元性化合物と、を有機溶剤中で混合し、銅粒子分散液を得る工程と、前記工程で得られた銅粒子分散液を溶剤洗浄し、前記銅粒子分散液から銅粒子を固液分離する洗浄工程とを有する銅粒子の製造方法であって、
　前記洗浄工程を密閉系で実施する銅粒子の製造方法。
［２］前記洗浄工程において、連続して溶剤置換及び洗浄する上記［１］に記載の銅粒子の製造方法。
［３］前記洗浄工程において、前記銅粒子を１～５０質量％含有する前記銅粒子分散液を流量５～１５００ｋｇ／ｈｒ・ｍ２、圧力０．０３～１．０ＭＰａでろ過膜に供給する上記［１］または［２］に記載の銅粒子の製造方法。
［４］前記銅粒子の平均粒子径が１～１０００ｎｍである上記［１］～［３］のいずれかに記載の銅粒子の製造方法。
［５］上記［１］～［４］のいずれかに記載の製造方法によって得られる銅粒子を含む接合用ペースト。
［６］上記［５］に記載の接合用ペーストを用いて接合されてなる半導体装置。
［７］上記［５］に記載の接合用ペーストを用いて接合されてなる電気・電子部品。 That is, the present disclosure relates to the following.
[1] A step of mixing a copper compound, an amine compound, and a reducing compound in an organic solvent to obtain a copper particle dispersion, and washing the copper particle dispersion obtained in the step with a solvent, A method for producing copper particles having a washing step of solid-liquid separation of copper particles from the particle dispersion,
A method for producing copper particles, wherein the washing step is performed in a closed system.
[2] The method for producing copper particles according to [1], wherein the solvent is continuously replaced and washed in the washing step.
[3] In the washing step, the copper particle dispersion containing 1 to 50% by mass of the copper particles is supplied to a filtration membrane at a flow rate of 5 to 1500 kg / hr · m 2 and a pressure of 0.03 to 1.0 MPa. The method for producing copper particles according to [1] or [2].
[4] The method for producing copper particles according to any one of the above [1] to [3], wherein the average particle diameter of the copper particles is 1 to 1000 nm.
[5] A bonding paste containing copper particles obtained by the production method according to any one of [1] to [4].
[6] A semiconductor device joined using the joining paste according to the above [5].
[7] An electric / electronic component joined using the joining paste according to the above [5].
　本開示によれば、還元雰囲気でなくとも低温焼結可能であり、接合層内部とフィレット部との焼結速度および焼結度が均一であり、接合特性が良好な銅粒子の製造方法、該製造方法によって得られる銅粒子を含む接合用ペースト並びに該接合用ペーストを使用することで信頼性に優れた半導体装置及び電気・電子部品を提供することができる。 According to the present disclosure, it is possible to sinter at a low temperature even in a reducing atmosphere, the sintering speed and the degree of sintering between the inside of the joining layer and the fillet portion are uniform, and a method for producing copper particles having good joining characteristics. A bonding paste containing copper particles obtained by a manufacturing method and a semiconductor device and an electric / electronic component having excellent reliability can be provided by using the bonding paste.
＜銅粒子の製造方法＞
　本開示の銅粒子の製造方法は、銅化合物と、アミン化合物と、還元性化合物と、を有機溶剤中で混合し、銅粒子分散液を得る工程と、前記工程で得られた銅粒子分散液を溶剤洗浄し、前記銅粒子分散液から銅粒子を固液分離する洗浄工程とを有する銅粒子の製造方法であって、前記洗浄工程を密閉系で実施する。
　本開示の銅粒子の製造方法では、前記洗浄工程を密閉系で実施することにより、銅粒子表面の酸化が制御され、接合特性が良好な銅粒子を得ることができる。 <Method for producing copper particles>
The method for producing copper particles of the present disclosure includes a step of mixing a copper compound, an amine compound, and a reducing compound in an organic solvent to obtain a copper particle dispersion, and the copper particle dispersion obtained in the step. And a washing step of solid-liquid separation of the copper particles from the copper particle dispersion liquid, wherein the washing step is performed in a closed system.
In the method for producing copper particles according to the present disclosure, by performing the washing step in a closed system, oxidation of the surface of the copper particles is controlled, and copper particles having good bonding characteristics can be obtained.
　以下、本開示について、一実施形態を参照しながら詳細に説明する。 Hereinafter, the present disclosure will be described in detail with reference to an embodiment.
［銅粒子分散液を得る工程］
　本工程では、原料である、銅化合物と、アミン化合物と、還元性化合物と、を有機溶剤中で混合し、銅粒子分散液を得る。
（銅化合物）
　本実施形態で用いられる銅化合物は、銅原子を含むものであれば特に限定されるものではない。銅化合物としては、例えば、カルボン酸銅、酸化銅、水酸化銅、窒化銅等が挙げられる。銅化合物は、反応時の均一性の観点からカルボン酸銅であってもよい。これらは単独で用いてもよく、２種以上を併用してもよい。 [Step of Obtaining Copper Particle Dispersion]
In this step, a raw material, a copper compound, an amine compound, and a reducing compound are mixed in an organic solvent to obtain a copper particle dispersion.
(Copper compound)
The copper compound used in the present embodiment is not particularly limited as long as it contains a copper atom. Examples of the copper compound include copper carboxylate, copper oxide, copper hydroxide, and copper nitride. The copper compound may be copper carboxylate from the viewpoint of uniformity during the reaction. These may be used alone or in combination of two or more.
　カルボン酸銅としては、ギ酸銅（Ｉ）、酢酸銅（Ｉ）、プロピオン酸銅（Ｉ）、酪酸銅（Ｉ）、吉草酸銅（Ｉ）、カプロン酸銅（Ｉ）、カプリル酸銅（Ｉ）、カプリン酸銅（Ｉ）、ギ酸銅（ＩＩ）、酢酸銅（ＩＩ）、プロピオン酸銅（ＩＩ）、酪酸銅（ＩＩ）、吉草酸銅（ＩＩ）、カプロン酸銅（ＩＩ）、カプリル酸銅（ＩＩ）、カプリン酸銅（ＩＩ）、クエン酸銅（ＩＩ）等のカルボン酸銅無水物または水和物が挙げられる。カルボン酸銅は、生産性および入手容易性の観点から酢酸銅（ＩＩ）一水和物であってもよい。また、これらは単独で用いてもよく、２種以上を併用してもよい。 Copper carboxylate includes copper formate (I), copper acetate (I), copper (I) propionate, copper (I) butyrate, copper (I) valerate, copper (I) caproate, copper (I) caprylate (I) ), Copper (I) caprate, copper (II) formate, copper (II) acetate, copper (II) propionate, copper (II) butyrate, copper (II) valerate, copper (II) caproate, caprylic acid Copper carboxylate anhydrides or hydrates such as copper (II), copper (II) caprate, copper (II) citrate and the like can be mentioned. Copper carboxylate may be copper acetate (II) monohydrate from the viewpoint of productivity and availability. These may be used alone or in combination of two or more.
　また、カルボン酸銅は、市販のものを使用してもよいし、合成によって得られたものを使用してもよい。 銅 In addition, commercially available copper carboxylate may be used, or copper carboxylate obtained by synthesis may be used.
　カルボン酸銅の合成は、公知の方法で行うことができ、例えば、水酸化銅（ＩＩ）とカルボン酸化合物とを混合・加熱によって得ることができる。 銅 Synthesis of copper carboxylate can be carried out by a known method, for example, it can be obtained by mixing and heating copper (II) hydroxide and a carboxylic acid compound.
　酸化銅としては、酸化銅（ＩＩ）、酸化銅（Ｉ）が挙げられ、生産性の観点から酸化銅（Ｉ）であってもよい。また、水酸化銅としては、水酸化銅（ＩＩ）、水酸化銅（Ｉ）が挙げられる。
　これらは単独で用いてもよく、２種以上を併用してもよい。 Examples of copper oxide include copper (II) oxide and copper (I) oxide, and copper (I) oxide may be used from the viewpoint of productivity. Examples of copper hydroxide include copper (II) hydroxide and copper (I) hydroxide.
These may be used alone or in combination of two or more.
（アミン化合物）
　本実施形態で用いられるアミン化合物は、銅化合物と錯体を形成するものであれば特に限定されないが、焼結性の観点から、アルキルアミン、アミノアルコール、アルコキシアミン及びカルボン酸アミン塩から選ばれる少なくとも１種を含む化合物であってもよく、カルボン酸アミン塩であってもよい。
　上記アミン化合物は、銅化合物とアミン化合物との錯体が加熱され銅化合物が分解する際に、銅化合物の分解反応の反応媒として機能するものである。さらに、上記アミン化合物は、銅化合物を熱分解することで得られる銅粒子の表面に付着し、酸化を制御する機能を有する。 (Amine compound)
The amine compound used in the present embodiment is not particularly limited as long as it forms a complex with the copper compound.From the viewpoint of sinterability, at least one selected from alkylamines, amino alcohols, alkoxyamines and carboxylic acid amine salts. It may be a compound containing one kind or a carboxylic acid amine salt.
The amine compound functions as a reaction medium for the decomposition reaction of the copper compound when the copper compound is decomposed by heating the complex of the copper compound and the amine compound. Further, the amine compound has a function of controlling oxidation by attaching to the surface of copper particles obtained by thermally decomposing the copper compound.
　このため、本実施形態で使用されるアミン化合物は、銅化合物との錯体の熱分解の条件、製造される銅粒子に期待される特性等に応じて、公知のアミン化合物から適宜選択して用いることができる。 For this reason, the amine compound used in the present embodiment is appropriately selected from known amine compounds according to the conditions of the thermal decomposition of the complex with the copper compound, the properties expected of the produced copper particles, and the like. be able to.
　ここで、アルキルアミンは、アミノ基と結合する基としてアルキル基等の脂肪族炭化水素基を有するアミン化合物であれば、特にその構造に制限がなく、例えば、アミノ基を１個有するアルキルモノアミン、アミノ基を２個有するアルキルジアミン等が挙げられる。なお、上記アルキル基はさらに置換基を有していてもよい。 Here, the alkylamine is not particularly limited in its structure as long as it is an amine compound having an aliphatic hydrocarbon group such as an alkyl group as a group bonded to an amino group, for example, an alkyl monoamine having one amino group, An alkyl diamine having two amino groups is exemplified. In addition, the said alkyl group may have a substituent further.
　具体的には、アルキルモノアミンとしては、ジプロピルアミン、ブチルアミン、ジブチルアミン、ヘキシルアミン、シクロヘキシルアミン、ヘプチルアミン、オクチルアミン、ノニルアミン、デシルアミン、３－アミノプロピルトリエトキシシラン、ドデシルアミン、オレイルアミン等、アルキルジアミンとしては、エチレンジアミン、Ｎ，Ｎ－ジメチルエチレンジアミン、Ｎ，Ｎ’－ジメチルエチレンジアミン、Ｎ，Ｎ－ジエチルエチレンジアミン、Ｎ，Ｎ’－ジエチルエチレンジアミン、１，３－プロパンジアミン、２，２－ジメチル－１，３－プロパンジアミン、Ｎ，Ｎ－ジメチル－１，３－ジアミノプロパン、Ｎ，Ｎ’－ジメチル－１，３－ジアミノプロパン、Ｎ，Ｎ－ジエチル－１，３－ジアミノプロパン、１，４－ジアミノブタン、１，５－ジアミノ－２－メチルペンタン、１，６－ジアミノヘキサン、Ｎ，Ｎ’－ジメチル－１，６－ジアミノヘキサン、１，７－ジアミノヘプタン、１，８－ジアミノオクタン等が挙げられる。
　なお、上述のカルボン酸銅と反応してカルボン酸銅－アミン錯体を効率的に形成するため、アルキルモノアミンは一級アミン（Ｒ１ＮＨ２）又は二級アミン（Ｒ２Ｒ３ＮＨ）等のアルキルモノアミンであってもよい。
　なお、アルキルアミンには、以下に説明するアミノアルコール及びアルコキシアミンは含まない。 Specifically, examples of the alkyl monoamine include dipropylamine, butylamine, dibutylamine, hexylamine, cyclohexylamine, heptylamine, octylamine, nonylamine, decylamine, 3-aminopropyltriethoxysilane, dodecylamine, and oleylamine. Examples of the diamine include ethylenediamine, N, N-dimethylethylenediamine, N, N′-dimethylethylenediamine, N, N-diethylethylenediamine, N, N′-diethylethylenediamine, 1,3-propanediamine, and 2,2-dimethyl-1. , 3-propanediamine, N, N-dimethyl-1,3-diaminopropane, N, N′-dimethyl-1,3-diaminopropane, N, N-diethyl-1,3-diaminopropane, 1,4- Diaminobutane, , 5-diamino-2-methylpentane, 1,6-diaminohexane, N, N'-dimethyl-1,6-diaminohexane, 1,7-diamino-heptane, 1,8-diamino octane.
In order to efficiently form a copper carboxylate-amine complex by reacting with the above-mentioned copper carboxylate, the alkyl monoamine is an alkyl such as a primary amine (R 1 NH 2 ) or a secondary amine (R 2 R 3 NH). It may be a monoamine.
The alkylamine does not include an amino alcohol and an alkoxyamine described below.
　また、アミノアルコールとしては、官能基としてヒドロキシル基を有するアミン化合物であれば、特にその構造に制限がなく、例えば、アミノ基を１個有するアルカノールモノアミン等が挙げられる。具体的には、アミノエタノール、ヘプタミノール、イソエタリン、プロパノールアミン、スフィンゴシン、１－アミノ－２－プロパノール、２－アミノジブタノール、２－ジエチルアミノエタノール、３－ジエチルアミノ－１，２－プロパンジオール、３－ジメチルアミノ－１，２－プロパンジオール、３－メチルアミノ－１，２－プロパンジオール、３－アミノ－１，２－プロパンジオール等が挙げられる。 The amino alcohol is not particularly limited in its structure as long as it is an amine compound having a hydroxyl group as a functional group, and examples thereof include an alkanol monoamine having one amino group. Specifically, aminoethanol, heptaminol, isoetalin, propanolamine, sphingosine, 1-amino-2-propanol, 2-aminodibutanol, 2-diethylaminoethanol, 3-diethylamino-1,2-propanediol, 3-dimethyl Amino-1,2-propanediol, 3-methylamino-1,2-propanediol, 3-amino-1,2-propanediol and the like.
　また、アルコキシアミンとしては、置換基としてアルコキシル基を有するアミン化合物であれば、特にその構造に制限がなく、例えば、アミノ基を１個有するアルコキシモノアミン、アミノ基を２個有するアルコキシジアミン等が挙げられる。具体的には、アルコキシモノアミンとしては、メトキシエチルアミン、２－エトキシエチルアミン、３－ブトキシプロピルアミン等が、アルコキシジアミンとしては、Ｎ－メトキシ－１，３－プロパンジアミン、Ｎ－メトキシ－１，４－ブタンジアミン等が挙げられる。アルコキシアミンは、還元され生成した銅に対する配位力を考慮し、一級アミン（Ｒ１ＯＮＨ２）又は二級アミン（Ｒ２（Ｒ３Ｏ）ＮＨ）等のアルコキシモノアミンであってもよい。 The alkoxyamine is not particularly limited in its structure as long as it is an amine compound having an alkoxyl group as a substituent, and examples thereof include an alkoxymonoamine having one amino group and an alkoxydiamine having two amino groups. Can be Specifically, methoxyethylamine, 2-ethoxyethylamine, 3-butoxypropylamine and the like are used as alkoxymonoamines, and N-methoxy-1,3-propanediamine and N-methoxy-1,4- are used as alkoxydiamines. Butanediamine and the like. The alkoxyamine may be an alkoxymonoamine such as a primary amine (R 1 ONH 2 ) or a secondary amine (R 2 (R 3 O) NH) in consideration of a coordination force to copper generated by reduction.
　ここで、上記アルキルアミン及びアルコキシアミンで記載している一級アミンの置換基Ｒ１はアルキル基を表し、炭素数４～１８のアルキル基であってもよい。また、二級アミンの置換基Ｒ２及びＲ３は、アルキル基を表し、共に炭素数４～１８のアルキル基であってもよい。置換基Ｒ２及びＲ３は、同一であっても異なっていてもよい。さらに、これらのアルキル基は、シリル基、グリシジル基等の置換基を有していてもよい。 Here, the substituent R 1 of the primary amine described in the above alkylamine and alkoxyamine represents an alkyl group, and may be an alkyl group having 4 to 18 carbon atoms. Further, the substituents R 2 and R 3 of the secondary amine represent an alkyl group, and both may be an alkyl group having 4 to 18 carbon atoms. The substituents R 2 and R 3 may be the same or different. Further, these alkyl groups may have a substituent such as a silyl group and a glycidyl group.
　カルボン酸アミン塩はカルボン酸化合物とアミン化合物から得ることができ、市販のものを使用してもよいし、予め合成によって得られたものを使用してもよい。カルボン酸アミン塩は、銅粒子の製造工程中で反応容器内にカルボン酸化合物とアミン化合物をそれぞれ別々に投入し、ｉｎ－ｓｉｔｕで生成させてもよい。 ア ミ ン The carboxylic acid amine salt can be obtained from a carboxylic acid compound and an amine compound, and a commercially available product may be used, or a product obtained in advance by synthesis may be used. The carboxylic acid amine salt may be formed in-situ by separately charging the carboxylic acid compound and the amine compound into the reaction vessel during the production process of the copper particles.
　カルボン酸アミン塩は、有機溶媒中でカルボン酸化合物とアミン化合物とを官能基等量で配合し、室温（２５℃）乃至は１００℃程度の比較的温和な温度条件で混合することで生成する。カルボン酸アミン塩は、生成物を含む上記反応液より、蒸留法または再結晶法などで取り出してもよい。 Carboxylic acid amine salts are formed by blending a carboxylic acid compound and an amine compound in an organic solvent in equivalent amounts of functional groups and mixing them under a relatively mild temperature condition of room temperature (25 ° C.) to about 100 ° C. . The amine carboxylate may be removed from the reaction solution containing the product by a distillation method, a recrystallization method, or the like.
　カルボン酸アミン塩を構成するカルボン酸化合物は、カルボキシ基を有する化合物であれば特に限定されず、例えば、モノカルボン酸、ジカルボン酸、芳香族カルボン酸、ヒドロキシ酸などが挙げられる。これらは単独で用いてもよく、２種以上を併用してもよい。上記カルボン酸化合物は、接合層内部とフィレット部との焼結速度の差を小さくする観点から、モノカルボン酸、ジカルボン酸であってもよい。 The carboxylic acid compound forming the carboxylic acid amine salt is not particularly limited as long as it has a carboxy group, and examples thereof include a monocarboxylic acid, a dicarboxylic acid, an aromatic carboxylic acid, and a hydroxy acid. These may be used alone or in combination of two or more. The carboxylic acid compound may be a monocarboxylic acid or a dicarboxylic acid from the viewpoint of reducing the difference in the sintering speed between the inside of the bonding layer and the fillet portion.
　カルボン酸アミン塩を構成するカルボン酸化合物は、接合層内部とフィレット部との焼結速度の差を小さくする観点から、熱分解温度が２００℃以下であってもよく、１９０℃以下であってもよく、１８０℃以下であってもよい。 The carboxylic acid compound constituting the carboxylic acid amine salt may have a thermal decomposition temperature of 200 ° C. or less, or 190 ° C. or less, from the viewpoint of reducing the difference in sintering speed between the inside of the bonding layer and the fillet portion. Or 180 ° C. or lower.
　また、カルボン酸アミン塩を構成するカルボン酸化合物のうち、熱分解温度より低温領域に沸点を有する化合物に関しては、沸点が２８０℃以下であってもよく、２６０℃以下であってもよく、２４０℃以下であってもよい。カルボン酸化合物の沸点がこの範囲にあると接合層内部とフィレット部との焼結速度の差が小さくなる。 Further, among the carboxylic acid compounds constituting the carboxylic acid amine salt, those having a boiling point in a region lower than the thermal decomposition temperature may have a boiling point of 280 ° C. or lower, 260 ° C. or lower, and 240 ° C. or lower. C. or lower. When the boiling point of the carboxylic acid compound is in this range, the difference in the sintering speed between the inside of the bonding layer and the fillet portion becomes small.
　カルボン酸アミン塩を構成するカルボン酸化合物のうち、モノカルボン酸としては、ギ酸、酢酸、プロピオン酸、酪酸、吉草酸、カプロン酸、カプリル酸、オクチル酸、ノナン酸、カプリン酸、オレイン酸、ステアリン酸、イソステアリン酸などが挙げられる。これらは、単独で用いてもよく、２種以上を併用してもよい。モノカルボン酸は、接合層内部とフィレット部との焼結速度の差を小さくする観点から、ギ酸、酢酸、プロピオン酸、酪酸、吉草酸、カプロン酸、カプリル酸、オクチル酸、ノナン酸、カプリン酸であってもよく、吉草酸、カプロン酸、カプリル酸、ノナン酸、オクチル酸であってもよい。 Among the carboxylic acid compounds constituting the carboxylic acid amine salts, monocarboxylic acids include formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, octylic acid, nonanoic acid, capric acid, oleic acid, and stearic acid Acids, isostearic acid and the like. These may be used alone or in combination of two or more. Monocarboxylic acid is formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, octylic acid, nonanoic acid, capric acid, from the viewpoint of reducing the difference in sintering rate between the inside of the bonding layer and the fillet portion. And valeric acid, caproic acid, caprylic acid, nonanoic acid and octylic acid.
　カルボン酸アミン塩を構成するカルボン酸化合物のうち、ジカルボン酸としては、シュウ酸、マロン酸、コハク酸、グルタル酸、アジピン酸、ピメリン酸、スベリン酸、アゼライン酸、セバシン酸、ジグリコール酸などが挙げられる。これらは単独で用いてもよく、２種以上を併用してもよい。接合層内部とフィレット部との焼結速度の差を小さくする観点から、シュウ酸、マロン酸、コハク酸、グルタル酸、アジピン酸、ジグリコール酸であってもよく、シュウ酸、マロン酸、コハク酸、ジグリコール酸であってもよい。 Among the carboxylic acid compounds constituting the carboxylic acid amine salt, examples of the dicarboxylic acid include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, diglycolic acid, and the like. No. These may be used alone or in combination of two or more. From the viewpoint of reducing the difference in sintering speed between the inside of the bonding layer and the fillet portion, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, diglycolic acid may be used, and oxalic acid, malonic acid, succinic acid may be used. An acid or diglycolic acid may be used.
　カルボン酸アミン塩を構成するカルボン酸化合物のうち、芳香族カルボン酸としては、安息香酸、フタル酸、イソフタル酸、テレフタル酸、サリチル酸、没食子酸などが挙げられる。これらは単独で用いてもよく、２種以上を併用してもよい。芳香族カルボン酸は、接合層内部とフィレット部との焼結速度の差を小さくする観点から、安息香酸であってもよい。 Among the carboxylic acid compounds constituting the carboxylic acid amine salt, examples of the aromatic carboxylic acid include benzoic acid, phthalic acid, isophthalic acid, terephthalic acid, salicylic acid, and gallic acid. These may be used alone or in combination of two or more. The aromatic carboxylic acid may be benzoic acid from the viewpoint of reducing the difference in the sintering speed between the inside of the bonding layer and the fillet portion.
　カルボン酸アミン塩を構成するカルボン酸化合物のうち、ヒドロキシ酸としては、グリコール酸、乳酸、タルトロン酸、リンゴ酸、グリセリン酸、ヒドロキシ酪酸、酒石酸、クエン酸、イソクエン酸などが挙げられる。これらは単独で用いてもよく、２種以上を併用してもよい。上記カルボン酸化合物は、接合層内部とフィレット部との焼結速度の差を小さくする観点から、グリコール酸、乳酸、リンゴ酸であってもよい。 Among the carboxylic acid compounds constituting the carboxylic acid amine salt, examples of the hydroxy acid include glycolic acid, lactic acid, tartronic acid, malic acid, glyceric acid, hydroxybutyric acid, tartaric acid, citric acid, and isocitric acid. These may be used alone or in combination of two or more. The carboxylic acid compound may be glycolic acid, lactic acid, or malic acid from the viewpoint of reducing the difference in the sintering speed between the inside of the bonding layer and the fillet portion.
　カルボン酸アミン塩を構成するアミン化合物としては、カルボキシ基を有する化合物であれば特に限定されず、例えば、アルキルモノアミン、アルキルジアミン、アルカノールアミンなどが挙げられる。これらは単独で用いてもよく、２種以上を併用してもよい。上記アミン化合物は、焼結性の観点から、アルキルモノアミン、アルカノールアミンであってもよい。 The amine compound constituting the carboxylic acid amine salt is not particularly limited as long as it has a carboxy group, and examples thereof include an alkyl monoamine, an alkyl diamine, and an alkanolamine. These may be used alone or in combination of two or more. The amine compound may be an alkyl monoamine or an alkanolamine from the viewpoint of sinterability.
　カルボン酸アミン塩を構成するアミン化合物のうち、アルキルモノアミンとしては、メチルアミン、エチルアミン、プロピルアミン、ブチルアミン、ヘキシルアミン、オクチルアミン、デシルアミン、ドデシルアミンなどが挙げられる。これらは単独で用いてもよく、２種以上を併用してもよい。上記アルキルモノアミンは、焼結性の観点から、ヘキシルアミン、オクチルアミン、デシルアミンであってもよい。 Among the amine compounds constituting the carboxylic acid amine salt, examples of the alkyl monoamine include methylamine, ethylamine, propylamine, butylamine, hexylamine, octylamine, decylamine, dodecylamine and the like. These may be used alone or in combination of two or more. The alkyl monoamine may be hexylamine, octylamine, or decylamine from the viewpoint of sinterability.
　カルボン酸アミン塩を構成するアミン化合物のうち、アルキルジアミンとしては、１，１－メタンジアミン、１，２－エタンジアミン、１，３－プロパンジアミン、１，４－ブタンジアミン、１，６－ヘキサンジアミン、１，８－オクタンジアミンなどが挙げられる。これらは単独で用いてもよく、２種以上を併用してもよい。上記アルキルジアミンは、焼結性の観点から、１，４－ブタンジアミン、１，６－ヘキサンジアミンであってもよい。 Among the amine compounds constituting the carboxylic acid amine salt, alkyldiamines include 1,1-methanediamine, 1,2-ethanediamine, 1,3-propanediamine, 1,4-butanediamine, and 1,6-hexane Diamine and 1,8-octanediamine are exemplified. These may be used alone or in combination of two or more. The alkyldiamine may be 1,4-butanediamine or 1,6-hexanediamine from the viewpoint of sinterability.
　カルボン酸アミン塩を構成するアミン化合物のうち、アルカノールアミンとしては、モノエタノールアミン、モノプロパノールアミン、モノブタノールアミン、２－（２－アミノエチルアミノ）エタノール、２－（２－アミノエトキシ）エタノール、１－アミノ－２－プロパノール、２－アミノ－１－プロパノール、３－アミノ－１，２－プロパンジオールなどが挙げられる。これらは単独で用いてもよく、２種以上を併用してもよい。上記アルカノールアミン類は、焼結性の観点から、モノエタノールアミン、モノプロパノールアミン、モノブタノールアミン、１－アミノ－２－プロパノール、２－アミノ－１－プロパノールであってもよい。 Among the amine compounds constituting the carboxylic acid amine salt, alkanolamines include monoethanolamine, monopropanolamine, monobutanolamine, 2- (2-aminoethylamino) ethanol, 2- (2-aminoethoxy) ethanol, Examples thereof include 1-amino-2-propanol, 2-amino-1-propanol, and 3-amino-1,2-propanediol. These may be used alone or in combination of two or more. The alkanolamines may be monoethanolamine, monopropanolamine, monobutanolamine, 1-amino-2-propanol, or 2-amino-1-propanol from the viewpoint of sinterability.
　上記アミノ化合物の沸点は、７０℃以上２８０℃以下であってもよく、１００℃以上２６０℃以下であってもよく、１２０℃以上２４０℃以下であってもよい。アミノ化合物の沸点が上記範囲にあれば得られた銅粒子は良好な焼結性を示す。
　また、アミノ化合物の沸点が７０℃以上であれば、得られた接合用ペーストは加熱工程でのアミノ化合物の揮発が制御されることから、系中の均一性が保たれる。アミノ化合物の沸点が２８０℃以下であれば、アミノ化合物が接合用ペーストの焼結時に除去され易いため、低温焼結性が発現する。
　さらに、アミノ化合物の沸点は、加熱工程における加熱温度以上であり、使用時における焼結温度以下であってもよい。 The boiling point of the amino compound may be 70 ° C to 280 ° C, 100 ° C to 260 ° C, or 120 ° C to 240 ° C. If the boiling point of the amino compound is in the above range, the obtained copper particles show good sinterability.
Further, when the boiling point of the amino compound is 70 ° C. or more, the obtained paste for joining is controlled in volatilization of the amino compound in the heating step, so that uniformity in the system is maintained. When the boiling point of the amino compound is 280 ° C. or lower, the amino compound is easily removed at the time of sintering the joining paste, and thus low-temperature sinterability is exhibited.
Furthermore, the boiling point of the amino compound may be higher than the heating temperature in the heating step and lower than the sintering temperature in use.
（還元性化合物）
　本実施形態で用いられる還元性化合物は、銅化合物を還元し、金属銅を遊離させる還元力を有するものであれば、特に限定されない。さらに、還元性化合物は、その沸点が７０℃以上であってもよく、加熱工程における加熱温度以上であってもよい。さらに、還元性化合物は、炭素、水素及び酸素から構成される後述する有機溶剤に溶解する化合物であってもよい。 (Reducing compound)
The reducing compound used in the present embodiment is not particularly limited as long as it has a reducing power for reducing a copper compound and releasing metallic copper. Furthermore, the reducing compound may have a boiling point of 70 ° C. or higher, or a heating temperature of the heating step or higher. Further, the reducing compound may be a compound that is dissolved in an organic solvent described below composed of carbon, hydrogen and oxygen.
　このような還元性化合物としては、典型的には、ヒドラジン誘導体が挙げられる。ヒドラジン誘導体としては、例えば、ヒドラジン一水和物、メチルヒドラジン、エチルヒドラジン、ｎ－プロピルヒドラジン、ｉ－プロピルヒドラジン、ｎ－ブチルヒドラジン、ｉ－
ブチルヒドラジン、ｓｅｃ－ブチルヒドラジン、ｔ－ブチルヒドラジン、ｎ－ペンチルヒドラジン、ｉ－ペンチルヒドラジン、ｎｅｏ－ペンチルヒドラジン、ｔ－ペンチルヒドラジン、ｎ－ヘキシルヒドラジン、ｉ－ヘキシルヒドラジン、ｎ－ヘプチルヒドラジン、ｎ－オクチルヒドラジン、ｎ－ノニルヒドラジン、ｎ－デシルヒドラジン、ｎ－ウンデシルヒドラジン、ｎ－ドデシルヒドラジン、シクロヘキシルヒドラジン、フェニルヒドラジン、４－メチルフェニルヒドラジン、ベンジルヒドラジン、２－フェニルエチルヒドラジン、２－ヒドラジノエタノール、アセトヒドラジン等が挙げられる。これらは単独で用いてもよく、２種以上を併用してもよい。 Such a reducing compound typically includes a hydrazine derivative. Examples of the hydrazine derivative include hydrazine monohydrate, methylhydrazine, ethylhydrazine, n-propylhydrazine, i-propylhydrazine, n-butylhydrazine, i-
Butylhydrazine, sec-butylhydrazine, t-butylhydrazine, n-pentylhydrazine, i-pentylhydrazine, neo-pentylhydrazine, t-pentylhydrazine, n-hexylhydrazine, i-hexylhydrazine, n-heptylhydrazine, n- Octylhydrazine, n-nonylhydrazine, n-decylhydrazine, n-undecylhydrazine, n-dodecylhydrazine, cyclohexylhydrazine, phenylhydrazine, 4-methylphenylhydrazine, benzylhydrazine, 2-phenylethylhydrazine, 2-hydrazinoethanol , Acetohydrazine and the like. These may be used alone or in combination of two or more.
　本実施形態の銅粒子の製造方法は、さらに下記化合物を含んでもよい。
（炭素数１～１２のカルボン酸）
　炭素数１～１２のカルボン酸は、得られる銅粒子の粒子径を制御するために使用される。カルボン酸はカルボキシル基を有するものであれば特に限定されない。例えば、ギ酸、酢酸、プロピオン酸、酪酸、吉草酸、カプロン酸、カプリル酸、オクチル酸、ノナン酸、カプリン酸、オレイン酸、ステアリン酸、イソステアリン酸等のモノカルボン酸；シュウ酸、マロン酸、コハク酸、グルタル酸、アジピン酸、ピメリン酸、スベリン酸、アゼライン酸、セバシン酸、ジグリコール酸等のジカルボン酸；安息香酸、フタル酸、イソフタル酸、テレフタル酸、サリチル酸、没食子酸等の芳香族カルボン酸；グリコール酸、乳酸、タルトロン酸、リンゴ酸、グリセリン酸、ヒドロキシ酪酸、酒石酸、クエン酸、イソクエン酸等のヒドロキシ酸などが挙げられる。粒径制御の容易性の観点から、ギ酸、酢酸、プロピオン酸、酪酸、吉草酸、カプロン酸、カプリル酸、オクチル酸、ノナン酸、カプリン酸、オレイン酸、ステアリン酸、イソステアリン酸、シュウ酸、マロン酸、コハク酸、グルタル酸、アジピン酸、ピメリン酸、スベリン酸、アゼライン酸、セバシン酸、ジグリコール酸であってもよく、焼結性の観点から、ギ酸、酢酸、プロピオン酸、酪酸、吉草酸、カプロン酸、カプリル酸、オクチル酸、シュウ酸、マロン酸、コハク酸であってもよく、カプロン酸、カプリル酸、オクチル酸、シュウ酸、マロン酸であってもよい。 The method for producing copper particles of the present embodiment may further include the following compound.
(Carboxylic acid having 1 to 12 carbon atoms)
A carboxylic acid having 1 to 12 carbon atoms is used for controlling the particle size of the obtained copper particles. The carboxylic acid is not particularly limited as long as it has a carboxyl group. For example, monocarboxylic acids such as formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, octylic acid, nonanoic acid, capric acid, oleic acid, stearic acid, and isostearic acid; oxalic acid, malonic acid, and succinic acid Dicarboxylic acids such as acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, and diglycolic acid; aromatic carboxylic acids such as benzoic acid, phthalic acid, isophthalic acid, terephthalic acid, salicylic acid, and gallic acid A hydroxy acid such as glycolic acid, lactic acid, tartronic acid, malic acid, glyceric acid, hydroxybutyric acid, tartaric acid, citric acid, and isocitric acid; From the viewpoint of easy particle size control, formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, octylic acid, nonanoic acid, capric acid, oleic acid, stearic acid, isostearic acid, oxalic acid, malon Acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, diglycolic acid may be used, and from the viewpoint of sinterability, formic acid, acetic acid, propionic acid, butyric acid, valeric acid , Caproic acid, caprylic acid, octylic acid, oxalic acid, malonic acid, succinic acid, or caproic acid, caprylic acid, octylic acid, oxalic acid, malonic acid.
（有機溶剤）
　本実施形態で用いられる有機溶剤は、上述の各原料を混合して得られる混合物から生成する錯体等の性質を阻害しない反応溶媒として用いることができるものであれば、特に限定されずに使用できる。有機溶剤は、上述の還元性化合物に対して相溶性を示すアルコールであってもよい。 (Organic solvent)
The organic solvent used in the present embodiment can be used without any particular limitation as long as it can be used as a reaction solvent that does not inhibit the properties of a complex or the like generated from a mixture obtained by mixing the above-described raw materials. . The organic solvent may be an alcohol that is compatible with the above-mentioned reducing compound.
　また、還元性化合物による銅イオンの還元反応は発熱反応である。したがって、有機溶剤は還元反応中に揮発しない有機溶剤であってもよい。このような有機溶剤を含有する接合ペーストは、銅化合物－アミン錯体の分解による銅イオンの生成及び生成した銅イオンの還元による金属銅の析出を安定的に制御できる。これにより、生成した銅粒子の粒径が安定する。したがって、有機溶剤はその沸点が７０℃以上であってもよい。さらに、有機溶剤は炭素、水素及び酸素から構成されていてもよい。 銅 The reduction reaction of copper ions by the reducing compound is an exothermic reaction. Therefore, the organic solvent may be an organic solvent that does not volatilize during the reduction reaction. The bonding paste containing such an organic solvent can stably control the formation of copper ions by the decomposition of the copper compound-amine complex and the precipitation of metallic copper by the reduction of the generated copper ions. Thereby, the particle size of the generated copper particles is stabilized. Therefore, the organic solvent may have a boiling point of 70 ° C. or higher. Further, the organic solvent may be composed of carbon, hydrogen and oxygen.
　有機溶剤として用いられる上記アルコールとしては、１－プロパノール、２－プロパノール、ブタノール、ペンタノール、ヘキサノール、ヘプタノール、オクタノール、エチレングリコール、１，３－プロパンジオール、１，２－プロパンジオール、ブチルカルビトール、ブチルカルビトールアセテート、エチルカルビトール、エチルカルビトールアセテート、ジエチレングリコールジエチルエーテル、ブチルセロソルブなどが挙げられる。これらは単独で用いてもよく、２種以上を併用してもよい。 Examples of the alcohol used as the organic solvent include 1-propanol, 2-propanol, butanol, pentanol, hexanol, heptanol, octanol, ethylene glycol, 1,3-propanediol, 1,2-propanediol, butyl carbitol, Butyl carbitol acetate, ethyl carbitol, ethyl carbitol acetate, diethylene glycol diethyl ether, butyl cellosolve and the like. These may be used alone or in combination of two or more.
（混合物の形成）
　本実施形態の銅粒子の製造方法は、まず、反応容器中に有機溶剤を収容し、該有機溶剤中において、上記説明した原料化合物である、銅化合物、アミン化合物、及び還元性化合物を混合する。これらの化合物の混合の順番は特に限定されず、上記化合物をどのような順番で混合しても構わない。 (Formation of the mixture)
In the method for producing copper particles of the present embodiment, first, an organic solvent is contained in a reaction vessel, and in the organic solvent, a copper compound, an amine compound, and a reducing compound, which are the above-described raw material compounds, are mixed. . The order of mixing these compounds is not particularly limited, and the above compounds may be mixed in any order.
　なお、銅化合物とアミン化合物との錯体を効率的に形成させる場合は、先に銅化合物とアミン化合物とを混合して、０～１１０℃で５～３０分程度混合しておき、さらに、還元性化合物を添加、混合してもよい。 In order to efficiently form a complex between the copper compound and the amine compound, the copper compound and the amine compound are first mixed, mixed at 0 to 110 ° C. for about 5 to 30 minutes, and further reduced. The active compound may be added and mixed.
　上記混合にあたって、各化合物の使用量は、銅化合物１ｍｏｌに対し、アミン化合物０．１～１０ｍｏｌ、還元性化合物０．５～５ｍｏｌであってもよく、アミン化合物１～１０ｍｏｌ、還元性化合物１～３ｍｏｌであってもよい。このとき、有機溶剤は各成分が十分に反応を行うことができる量であればよく、例えば、５０～２０００ｍＬ程度用いるようにすればよい。 In the mixing, each compound may be used in an amount of 0.1 to 10 mol of the amine compound and 0.5 to 5 mol of the reducing compound, or 1 to 10 mol of the amine compound and 1 to 10 mol of the reducing compound, based on 1 mol of the copper compound. It may be 3 mol. At this time, the organic solvent may be used in such an amount that each component can sufficiently react. For example, about 50 to 2000 mL may be used.
（混合物の加熱）
　本実施形態の銅粒子の製造方法は、次に、上記で混合して得られた混合物を十分に加熱して銅化合物の還元反応を進行させる。この加熱により、未反応の銅化合物をなくすことができ、金属銅を析出、成長させ、銅粒子を形成することができる。 (Heating of the mixture)
Next, in the method for producing copper particles of the present embodiment, the mixture obtained by mixing the above is heated sufficiently to cause the reduction reaction of the copper compound to proceed. By this heating, unreacted copper compounds can be eliminated, and metallic copper can be deposited and grown to form copper particles.
　このとき、アミン化合物は、銅粒子の表面に付着し、成長を制御することで粒子が粗大化するのを防ぐ作用を有している。 At this time, the amine compound adheres to the surface of the copper particles and has an action of controlling the growth to prevent the particles from becoming coarse.
　上記混合物の加熱温度は、銅化合物が熱分解及び還元され、銅粒子が生成できる温度であればよい。上記加熱温度は、７０～１５０℃であってもよく、８０～１２０℃であってもよい。また、加熱温度は原料化合物及び有機溶剤の沸点よりも低くてもよい。加熱温度が上記範囲内にあると、銅粒子を効率的に生成できる。さらに、アミン化合物の他にカルボン酸を併用することで、これら揮発成分の揮発が制御される。 加熱 The heating temperature of the above mixture may be any temperature at which the copper compound is thermally decomposed and reduced to produce copper particles. The heating temperature may be 70 to 150 ° C, or may be 80 to 120 ° C. Further, the heating temperature may be lower than the boiling points of the raw material compound and the organic solvent. When the heating temperature is within the above range, copper particles can be efficiently generated. Furthermore, the volatilization of these volatile components is controlled by using a carboxylic acid in addition to the amine compound.
　加熱温度を７０℃以上にすることで、銅化合物の熱分解が進行する。加熱温度を１５０℃以下にすることで、アミン化合物の揮発が制御されることから、系中の均一性が保たれる。 熱 By setting the heating temperature to 70 ° C. or higher, the thermal decomposition of the copper compound proceeds. By setting the heating temperature to 150 ° C. or lower, volatilization of the amine compound is controlled, so that uniformity in the system is maintained.
　このようにして、銅粒子分散液を得ることができる。なお、本実施形態の接合ペーストの製造方法は、得られた銅粒子分散液に後述する洗浄溶剤を加えて当該銅粒子分散液中に含有される銅粒子の濃度を１～５０質量％に調製してもよい。 銅 Thus, a copper particle dispersion can be obtained. In the method for producing a bonding paste according to the present embodiment, the concentration of copper particles contained in the copper particle dispersion is adjusted to 1 to 50% by mass by adding a cleaning solvent described below to the obtained copper particle dispersion. May be.
［洗浄工程］
　本工程では、前記工程で得られた銅粒子分散液を密閉系で溶剤洗浄し、前記銅粒子分散液から銅粒子を固液分離する。
　銀微粒子の製造時に一般に用いられている遠心分離等による分離作業では、連続して溶剤置換することができず、大気中で洗浄溶剤との撹拌作業が行われる。本発明者らの知見によると、合成した銅粒子は容易に粒子表面が酸化されやすく、特に大気中で洗浄溶剤と撹拌する時に銅粒子分散液に巻き込んだ酸素と、合成した銅粒子が接触することにより銅粒子表面の酸化が進行してしまうおそれがある。これに対し、本工程では、密閉系で銅粒子分散液を溶剤洗浄することにより、銅粒子の表面酸化を低減することができる。 [Washing process]
In this step, the copper particle dispersion obtained in the above step is solvent-washed in a closed system, and copper particles are solid-liquid separated from the copper particle dispersion.
In the separation operation such as centrifugation generally used in the production of silver fine particles, the solvent cannot be continuously replaced, and the stirring operation with the cleaning solvent is performed in the atmosphere. According to the findings of the present inventors, the synthesized copper particles are easily oxidized on the surface of the particles, and the oxygen caught in the copper particle dispersion liquid particularly when stirred with a cleaning solvent in the air comes into contact with the synthesized copper particles. As a result, oxidation of the copper particle surface may proceed. On the other hand, in this step, the surface oxidation of the copper particles can be reduced by washing the copper particle dispersion with a solvent in a closed system.
　また、本洗浄工程は、連続した溶剤置換及び洗浄方法であってもよい。本実施形態の銅粒子の製造方法で得られる銅粒子は、連続して処理することで、銅粒子の表面酸化が低減する。
　具体的な溶剤置換洗浄方法は、銅粒子を１～５０質量％含有する前記銅粒子分散液をリスラリーすることなく流量５～１５００ｋｇ／ｈｒ・ｍ２、圧力０．０３～１．０ＭＰａの条件でろ過膜に供給し、さらに、上記条件により洗浄溶剤を連続して該ろ過膜に供給する。本実施形態の銅粒子の製造方法で得られる銅粒子は、このように、銅粒子分散液に洗浄溶剤を流量５～１５００ｋｇ／ｈｒ・ｍ２で供給し、０．０３～１．０ＭＰａで加圧し、銅粒子分散液と洗浄用剤の置換を密閉系で行うことで、酸素が存在しない状態で銅粒子を洗浄するため、該銅粒子の表面酸化を低減することができる。
　また、このような観点から、上記流量は１０～１０００ｋｇ／ｈｒ・ｍ２であってもよく、１５～５００ｋｇ／ｈｒ・ｍ２であってもよく、２０～２００ｋｇ／ｈｒ・ｍ２であってもよい。上記圧力は０．１～０．８ＭＰａであってもよく、０．２～０．６ＭＰａであってもよい。
　なお、上記溶剤置換及び洗浄は、後述する減圧乾燥、遠心分離等を行った後に、さらに実施してもよい。 The present cleaning step may be a continuous solvent replacement and cleaning method. By continuously treating the copper particles obtained by the method for producing copper particles of the present embodiment, the surface oxidation of the copper particles is reduced.
A specific solvent replacement washing method is performed under the conditions of a flow rate of 5 to 1500 kg / hr · m 2 and a pressure of 0.03 to 1.0 MPa without reslurrying the copper particle dispersion containing 1 to 50% by mass of copper particles. The solvent is supplied to the filtration membrane, and the washing solvent is continuously supplied to the filtration membrane under the above conditions. As described above, the copper particles obtained by the method for producing copper particles of the present embodiment are supplied with a cleaning solvent to the copper particle dispersion at a flow rate of 5 to 1500 kg / hr · m 2 and applied at a flow rate of 0.03 to 1.0 MPa. By pressurizing and replacing the copper particle dispersion with the cleaning agent in a closed system, the copper particles are cleaned in the absence of oxygen, so that surface oxidation of the copper particles can be reduced.
Further, from such a viewpoint, the flow rate may be 10 to 1000 kg / hr · m 2 , 15 to 500 kg / hr · m 2 , or 20 to 200 kg / hr · m 2. Is also good. The pressure may be 0.1 to 0.8 MPa, or may be 0.2 to 0.6 MPa.
The solvent replacement and washing may be further performed after drying under reduced pressure, centrifugation, and the like, which will be described later.
　洗浄溶剤は生成した銅粒子の保護基にダメージを与えないものであれば、特に限定されずに使用できる。具体的には、水；エタノール、メタノール等のアルコール類；ジエチレングリコール等のグリコール類；その他の溶剤等が挙げられる。洗浄溶剤は濾室容積の３～７倍の量を供給してもよい。 The washing solvent can be used without any particular limitation as long as it does not damage the protective group of the produced copper particles. Specific examples include water; alcohols such as ethanol and methanol; glycols such as diethylene glycol; and other solvents. The washing solvent may be supplied in an amount of 3 to 7 times the volume of the filtration chamber.
　溶剤置換装置は密閉して溶剤洗浄できれば特に限定されないが、例えば回転型膜分離装置であってもよく、具体的には水平濾板式濾過機（三菱化工機（株）製）が挙げられる。
　濾別した固形物に対し、例えば減圧乾燥、遠心分離等を行うことにより、銅粒子を得ることができる。 The solvent replacement device is not particularly limited as long as the solvent can be sealed and the solvent can be washed. For example, a rotary membrane separation device may be used, and specific examples thereof include a horizontal filter plate type filter (manufactured by Mitsubishi Kakoki Co., Ltd.).
Copper particles can be obtained by performing, for example, drying under reduced pressure, centrifugal separation, and the like on the solids separated by filtration.
（銅粒子の形状、サイズ）
　本実施形態の銅粒子の製造方法により得られる銅粒子は、銅化合物がアミン化合物中で還元性化合物により還元され、溶出した銅原子が凝集し、核形成、核成長し、アミン化合物で被覆された銅粒子が形成されると推察される。したがって、使用する銅化合物、アミン化合物、還元性化合物の種類、反応温度を適宜選択することによって、銅原子の供給速度、あるいはアミン化合物による吸着能を変化させ、任意の形状及びサイズの銅粒子を得ることができる。 (Shape and size of copper particles)
Copper particles obtained by the method for producing copper particles of the present embodiment, the copper compound is reduced by the reducing compound in the amine compound, the eluted copper atoms aggregate, nucleation, nucleus growth, coated with the amine compound It is presumed that copper particles were formed. Therefore, by appropriately selecting the type of the copper compound, the amine compound, and the reducing compound to be used, and the reaction temperature, the supply rate of the copper atom or the adsorption ability by the amine compound is changed, so that copper particles of any shape and size can be obtained. Obtainable.
　本実施形態の銅粒子の製造方法により得られる銅粒子は、３００℃未満の低温焼成が可能である。これを用いた接合用ペーストは、接合層内部とフィレット部との焼結速度および焼結度に差がなく、接合信頼性の高い接合層を得ることができる。 銅 The copper particles obtained by the method for producing copper particles of the present embodiment can be fired at a low temperature of less than 300 ° C. The joining paste using this has no difference in the sintering speed and the degree of sintering between the inside of the joining layer and the fillet portion, and a joining layer with high joining reliability can be obtained.
　上記銅粒子の平均粒子径は、接合層の緻密性の観点から、１～１０００ｎｍであってもよく、２０～８００ｎｍであってもよく、３０～５００ｎｍであってもよい。
　なお、上記銅粒子の平均粒子径は、走査電子顕微鏡（例えば、日本電子（株）製、商品名：ＪＳＭ－７６００Ｆ；ＳＥＭ）の観察画像に基づく任意に選択した１０個の銅粒子（ｎ＝１０）の平均値として算出する。なお、平均値は算術平均値であり、その算出にあたっては１０個以上の銅粒子を用いてもよい。 The average particle diameter of the copper particles may be 1 to 1000 nm, 20 to 800 nm, or 30 to 500 nm from the viewpoint of the denseness of the bonding layer.
The average particle diameter of the copper particles was determined based on an observation image of a scanning electron microscope (for example, trade name: JSM-7600F; SEM, manufactured by JEOL Ltd.). Calculated as the average value of 10). Note that the average value is an arithmetic average value, and 10 or more copper particles may be used in the calculation.
＜接合用ペースト＞
　本実施形態の接合用ペーストは、上述の銅粒子の製造方法によって得られる銅粒子を含む。本実施形態の接合用ペーストは、無加圧での接合が可能であり接着性に優れている。また、本実施形態の接合用ペーストは、接合層内部とフィレット部との焼結速度および焼結度が均一であり、接合特性が良好である。
　したがって、本実施形態の接合用ペーストは、素子接着用ダイアタッチペースト又は放熱部材接着用材料として使用できる。 <Joining paste>
The bonding paste of the present embodiment contains copper particles obtained by the above-described method for producing copper particles. The joining paste of the present embodiment can be joined without pressure and has excellent adhesiveness. In addition, the bonding paste of the present embodiment has a uniform sintering speed and sintering degree between the inside of the bonding layer and the fillet portion, and has good bonding characteristics.
Therefore, the bonding paste of this embodiment can be used as a die attach paste for bonding elements or a material for bonding heat dissipation members.
　本実施形態の接合用ペーストは、２つ以上の異なる平均粒子径の銅粒子を併用してもよい。例えば、第一の銅粒子の平均粒子径に対して、該第一の銅粒子よりも大きい平均粒子径を有する第二の銅粒子の平均粒子径は２～１０倍程度であってもよい。また、第一の銅粒子の配合量に対して、第二の銅粒子の配合量は１．５～１０倍程度であってもよい。 接合 The joining paste of the present embodiment may use two or more copper particles having different average particle diameters in combination. For example, the average particle diameter of the second copper particles having a larger average particle diameter than the first copper particles may be about 2 to 10 times the average particle diameter of the first copper particles. The amount of the second copper particles may be about 1.5 to 10 times the amount of the first copper particles.
　本実施形態の接合用ペーストは上述の銅粒子以外に、上述の銅粒子よりも粒径の大きい大粒径銅粒子、熱硬化性樹脂、有機溶剤、その他添加剤を含んでもよい。これにより、銅粒子の焼結収縮の影響を緩和し、さらに信頼性の高い接合層を形成することが可能となる。 接合 In addition to the above-described copper particles, the bonding paste of the present embodiment may include large-diameter copper particles having a larger particle size than the above-described copper particles, a thermosetting resin, an organic solvent, and other additives. Thereby, the influence of the sintering shrinkage of the copper particles can be reduced, and a more reliable bonding layer can be formed.
（大粒径銅粒子）
　大粒径銅粒子は、平均粒子径が１μｍよりも大きく３０μｍ以下であってもよく、２～２０μｍであってもよい。また、形状は特に限定されず、球状、プレート型、フレーク状、鱗片状、樹枝状、ロッド状、ワイヤー状等が使用できる。
　なお、上記大粒径銅粒子の平均粒子径は、レーザー回折散乱式粒度分布測定装置等を用いて測定することができる。 (Large-sized copper particles)
The large-diameter copper particles may have an average particle diameter of more than 1 μm and 30 μm or less, or 2 to 20 μm. The shape is not particularly limited, and spheres, plates, flakes, scales, dendrites, rods, wires, and the like can be used.
The average particle diameter of the large-diameter copper particles can be measured using a laser diffraction / scattering particle size distribution analyzer or the like.
　上記大粒径銅粒子は、滑材、防錆剤で処理されているものを使用してもよい。このような処理として典型的なものは、カルボン酸化合物による処理である。カルボン酸化合物としては、例えば、ギ酸、酢酸、プロピオン酸、酪酸、吉草酸、カプロン酸、カプリル酸、オクチル酸、ノナン酸、カプリン酸、パルミチン酸、オレイン酸、ステアリン酸、イソステアリン酸、シュウ酸、マロン酸、コハク酸、グルタル酸、アジピン酸、ピメリン酸、スベリン酸、アゼライン酸、セバシン酸、ジグリコール酸、安息香酸、フタル酸、イソフタル酸、テレフタル酸、サリチル酸、没食子酸、グリコール酸、乳酸、タルトロン酸、リンゴ酸、グリセリン酸、ヒドロキシ酪酸、酒石酸、クエン酸、イソクエン酸などが挙げられる。カルボン酸化合物は、銅粒子との焼結性の観点から、ギ酸、酢酸、プロピオン酸、酪酸、吉草酸、カプロン酸、カプリル酸、オクチル酸、ノナン酸、カプリン酸、パルミチン酸、オレイン酸、ステアリン酸、イソステアリン酸、シュウ酸、マロン酸、コハク酸、グルタル酸であってもよい。また、カルボン酸化合物は、銅粒子の分散性および耐酸化性の観点から、カプロン酸、カプリル酸、オクチル酸、ノナン酸、カプリン酸、マロン酸、コハク酸、グルタル酸であってもよい。 The large-sized copper particles may be treated with a lubricant and a rust preventive. A typical example of such a treatment is a treatment with a carboxylic acid compound. Examples of the carboxylic acid compound include formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, octylic acid, nonanoic acid, capric acid, palmitic acid, oleic acid, stearic acid, isostearic acid, oxalic acid, Malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, diglycolic acid, benzoic acid, phthalic acid, isophthalic acid, terephthalic acid, salicylic acid, gallic acid, glycolic acid, lactic acid, Examples thereof include tartronic acid, malic acid, glyceric acid, hydroxybutyric acid, tartaric acid, citric acid, and isocitrate. From the viewpoint of sinterability with copper particles, carboxylic acid compounds include formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, octylic acid, nonanoic acid, capric acid, palmitic acid, oleic acid, and stearic acid. It may be an acid, isostearic acid, oxalic acid, malonic acid, succinic acid, glutaric acid. The carboxylic acid compound may be caproic acid, caprylic acid, octylic acid, nonanoic acid, capric acid, malonic acid, succinic acid, or glutaric acid from the viewpoint of the dispersibility and oxidation resistance of the copper particles.
（熱硬化性樹脂）
　熱硬化性樹脂は、一般に接着剤用途として使用される熱硬化性樹脂であれば特に限定されずに使用できる。熱硬化性樹脂は、液状樹脂であってもよく、室温（２５℃）で液状である樹脂であってもよい。上記熱硬化性樹脂としては、例えば、シアネート樹脂、エポキシ樹脂、ラジカル重合性のアクリル樹脂、マレイミド樹脂などが挙げられる。これらは単独で用いてもよく、２種以上を併用してもよい。
　本実施形態の接合用ペーストが熱硬化性樹脂を含むことで、適度な粘度を有する接着材料（ペースト）とすることができる。また、本実施形態の接合用ペーストが熱硬化性樹脂を含むと、その硬化時の反応熱によって接合用ペーストの温度が上昇し、銅粒子の焼結性を促進させる。 (Thermosetting resin)
The thermosetting resin can be used without particular limitation as long as it is a thermosetting resin generally used as an adhesive. The thermosetting resin may be a liquid resin or a resin that is liquid at room temperature (25 ° C.). Examples of the thermosetting resin include a cyanate resin, an epoxy resin, a radically polymerizable acrylic resin, and a maleimide resin. These may be used alone or in combination of two or more.
When the bonding paste of the present embodiment contains a thermosetting resin, an adhesive material (paste) having an appropriate viscosity can be obtained. Further, when the joining paste of the present embodiment contains a thermosetting resin, the temperature of the joining paste rises due to the reaction heat at the time of curing, thereby promoting the sinterability of the copper particles.
　シアネート樹脂は、分子内に－ＮＣＯ基を有する化合物であり、加熱により－ＮＣＯ基が反応することで３次元的網目構造を形成し、硬化する樹脂である。具体的に例示すると、１，３－ジシアナトベンゼン、１，４－ジシアナトベンゼン、１，３，５－トリシアナトベンゼン、１，３－ジシアナトナフタレン、１，４－ジシアナトナフタレン、１，６－ジシアナトナフタレン、１，８－ジシアナトナフタレン、２，６－ジシアナトナフタレン、２，７－ジシアナトナフタレン、１，３，６－トリシアナトナフタレン、４，４’－ジシアナトビフェニル、ビス（４－シアナトフェニル）メタン、ビス（３，５－ジメチル－４－シアナトフェニル）メタン、２，２－ビス（４－シアナトフェニル）プロパン、２，２－ビス（３，５－ジブロモ－４－シアナトフェニル）プロパン、ビス（４－シアナトフェニル）エーテル、ビス（４－シアナトフェニル）チオエーテル、ビス（４－シアナトフェニル）スルホン、トリス（４－シアナトフェニル）ホスファイト、トリス（４－シアナトフェニル）ホスフェート、及びノボラック樹脂とハロゲン化シアンとの反応により得られるシアネート類などが挙げられる。シアネート樹脂は、上記多官能シアネート樹脂のシアネート基を三量化することによって形成されるトリアジン環を有するプレポリマーも使用できる。該プレポリマーは、上記の多官能シアネート樹脂モノマーを、例えば、鉱酸、ルイス酸などの酸、ナトリウムアルコラート、第三級アミン類などの塩基、炭酸ナトリウムなどの塩類、を触媒として重合させることにより得られる。 Cyanate resin is a compound having a —NCO group in a molecule, and is a resin that forms a three-dimensional network structure and is cured by a reaction of the —NCO group by heating. Specific examples include 1,3-dicyanatobenzene, 1,4-dicyanatobenzene, 1,3,5-tricyanatobenzene, 1,3-dicyanatonaphthalene, 1,4-dicyanatonaphthalene, 6-dicyanatonaphthalene, 1,8-dicyanatonaphthalene, 2,6-dicyanatonaphthalene, 2,7-dicyanatonaphthalene, 1,3,6-tricyanatonaphthalene, 4,4′-dicyanatobiphenyl, bis (4-cyanatophenyl) methane, bis (3,5-dimethyl-4-cyanatophenyl) methane, 2,2-bis (4-cyanatophenyl) propane, 2,2-bis (3,5-dibromo -4-cyanatophenyl) propane, bis (4-cyanatophenyl) ether, bis (4-cyanatophenyl) thioether, bis (4-cyanatophenyl) Sulfone, tris (4-cyanatophenyl) phosphite, tris (4-cyanatophenyl) phosphate, and the like cyanates obtained by a reaction between novolak resin and a cyanogen halide. As the cyanate resin, a prepolymer having a triazine ring formed by trimerizing the cyanate group of the polyfunctional cyanate resin can also be used. The prepolymer is obtained by polymerizing the above polyfunctional cyanate resin monomer with, for example, a mineral acid, an acid such as a Lewis acid, a base such as sodium alcoholate, a tertiary amine, or a salt such as sodium carbonate as a catalyst. can get.
　シアネート樹脂の硬化促進剤としては、一般に公知のものが使用できる。例えば、オクチル酸亜鉛、オクチル酸錫、ナフテン酸コバルト、ナフテン酸亜鉛、アセチルアセトン鉄などの有機金属錯体、塩化アルミニウム、塩化錫、塩化亜鉛などの金属塩、トリエチルアミン、ジメチルベンジルアミンなどのアミン類が挙げられるが、これらに限定されるものではない。これらの硬化促進剤は１種又は２種以上混合して用いることができる。 As the curing accelerator for the cyanate resin, generally known curing accelerators can be used. For example, organometallic complexes such as zinc octylate, tin octylate, cobalt naphthenate, zinc naphthenate, and iron acetylacetone; metal salts such as aluminum chloride, tin chloride and zinc chloride; and amines such as triethylamine and dimethylbenzylamine. However, the present invention is not limited to these. These curing accelerators can be used alone or in combination of two or more.
　エポキシ樹脂は、グリシジル基を分子内に１つ以上有する化合物であり、加熱によりグリシジル基が反応することで３次元的網目構造を形成し、硬化する樹脂である。グリシジル基は１分子に２つ以上含まれていてもよい。これはグリシジル基が１つの化合物のみでは反応させても十分な硬化物特性を示すことができないからである。グリシジル基を１分子に２つ以上含む化合物は、２つ以上の水酸基を有する化合物をエポキシ化して得ることができる。このような化合物としては、ビスフェノールＡ、ビスフェノールＦ、ビフェノールなどのビスフェノール化合物又はこれらの誘導体、水素添加ビスフェノールＡ、水素添加ビスフェノールＦ、水素添加ビフェノール、シクロヘキサンジオール、シクロヘキサンジメタノール、シクロヘキサンジエタノールなどの脂環構造を有するジオール又はこれらの誘導体、ブタンジオール、ヘキサンジオール、オクタンジオール、ノナンジオール、デカンジオールなどの脂肪族ジオール又はこれらの誘導体などをエポキシ化した２官能のもの、トリヒドロキシフェニルメタン骨格、アミノフェノール骨格を有する化合物などをエポキシ化した３官能のもの、フェノールノボラック樹脂、クレゾールノボラック樹脂、フェノールアラルキル樹脂、ビフェニルアラルキル樹脂、ナフトールアラルキル樹脂などをエポキシ化した多官能のものなどが挙げられるが、これらに限定されるわけではない。また、上記エポキシ樹脂は、接合用ペーストとして室温（２５℃）でペースト状とするため、単独で又は混合物として室温（２５℃）で液状のものであってもよい。通常行われるように反応性希釈剤を使用することも可能である。反応性希釈剤としては、フェニルグリシジルエーテル、クレジルグリシジルエーテルなどの１官能の芳香族グリシジルエーテル類、脂肪族グリシジルエーテル類などが挙げられる。 Epoxy resin is a compound having one or more glycidyl groups in a molecule, and is a resin that forms a three-dimensional network structure by being reacted with glycidyl groups by heating, and is cured. Two or more glycidyl groups may be contained in one molecule. This is because the glycidyl group cannot exhibit sufficient cured product characteristics even when reacted with only one compound. A compound containing two or more glycidyl groups in one molecule can be obtained by epoxidizing a compound having two or more hydroxyl groups. Examples of such compounds include bisphenol compounds such as bisphenol A, bisphenol F, and biphenol or derivatives thereof, and alicyclic rings such as hydrogenated bisphenol A, hydrogenated bisphenol F, hydrogenated biphenol, cyclohexanediol, cyclohexanedimethanol, and cyclohexanediethanol. Bifunctional ones obtained by epoxidizing aliphatic diols such as diols having a structure or derivatives thereof, aliphatic diols such as butanediol, hexanediol, octanediol, nonanediol, and decanediol; trihydroxyphenylmethane skeleton; aminophenol Trifunctional compounds obtained by epoxidizing compounds having a skeleton, phenol novolak resin, cresol novolak resin, phenol aralkyl resin, biphenyl Aralkyl resins, and the naphthol aralkyl resin as polyfunctional epoxidized include, without limitation thereto. In addition, since the epoxy resin is a paste at room temperature (25 ° C.) as a bonding paste, it may be liquid alone or at room temperature (25 ° C.) as a mixture. It is also possible to use reactive diluents as usual. Examples of the reactive diluent include monofunctional aromatic glycidyl ethers such as phenyl glycidyl ether and cresyl glycidyl ether, and aliphatic glycidyl ethers.
　このとき、エポキシ樹脂を硬化させるために硬化剤を使用するが、エポキシ樹脂の硬化剤としては、例えば、脂肪族アミン、芳香族アミン、ジシアンジアミド、ジヒドラジド化合物、酸無水物、フェノール樹脂などが挙げられる。ジヒドラジド化合物としては、アジピン酸ジヒドラジド、ドデカン酸ジヒドラジド、イソフタル酸ジヒドラジド、ｐ－オキシ安息香酸ジヒドラジドなどのカルボン酸ジヒドラジドなどが挙げられ、酸無水物としては、フタル酸無水物、テトラヒドロ無水フタル酸、ヘキサヒドロ無水フタル酸、エンドメチレンテトラヒドロフタル酸無水物、ドデセニルコハク酸無水物、無水マレイン酸とポリブタジエンの反応物、無水マレイン酸とスチレンの共重合体などが挙げられる。 At this time, a curing agent is used to cure the epoxy resin. Examples of the curing agent for the epoxy resin include an aliphatic amine, an aromatic amine, dicyandiamide, a dihydrazide compound, an acid anhydride, and a phenol resin. . Examples of the dihydrazide compound include carboxylic acid dihydrazides such as adipic dihydrazide, dodecanoic dihydrazide, isophthalic dihydrazide, and p-oxybenzoic dihydrazide.The acid anhydrides include phthalic anhydride, tetrahydrophthalic anhydride, Examples include phthalic anhydride, endomethylenetetrahydrophthalic anhydride, dodecenylsuccinic anhydride, a reaction product of maleic anhydride and polybutadiene, and a copolymer of maleic anhydride and styrene.
　さらに、硬化を促進するために硬化促進剤を配合でき、エポキシ樹脂の硬化促進剤としては、イミダゾール類、トリフェニルホスフィン又はテトラフェニルホスフィン及びそれらの塩類、ジアザビシクロウンデセンなどのアミン系化合物及びその塩類などが挙げられる。硬化促進剤は、２－メチルイミダゾール、２－エチルイミダゾール、２－フェニルイミダゾール、２－フェニル－４－メチルイミダゾール、２－フェニル－４－メチル－５－ヒドロキシメチルイミダゾール、２－フェニル－４，５－ジヒドロキシメチルイミダゾール、２－Ｃ１１Ｈ２３－イミダゾール、２－メチルイミダゾールと２，４－ジアミノ－６－ビニルトリアジンとの付加物などのイミダゾール化合物であってもよい。硬化促進剤は、融点が１８０℃以上のイミダゾール化合物であってもよい。 Further, a curing accelerator can be blended to promote curing.Examples of curing accelerators for epoxy resins include imidazoles, triphenylphosphine or tetraphenylphosphine and salts thereof, amine compounds such as diazabicycloundecene, and the like. And salts thereof. Curing accelerators include 2-methylimidazole, 2-ethylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2-phenyl-4,5 Imidazole compounds such as -dihydroxymethylimidazole, 2-C 11 H 23 -imidazole, and adducts of 2-methylimidazole with 2,4-diamino-6-vinyltriazine. The curing accelerator may be an imidazole compound having a melting point of 180 ° C. or higher.
　ラジカル重合性のアクリル樹脂とは、分子内に（メタ）アクリロイル基を有する化合物であり、（メタ）アクリロイル基が反応することで３次元的網目構造を形成し、硬化する樹脂である。（メタ）アクリロイル基は分子内に１つ以上含まれていてもよい。 A radically polymerizable acrylic resin is a compound having a (meth) acryloyl group in the molecule, and is a resin that forms a three-dimensional network structure by the reaction of the (meth) acryloyl group and is cured. One or more (meth) acryloyl groups may be contained in the molecule.
　ここで、アクリル樹脂としては、例えば、２－ヒドロキシエチル（メタ）アクリレート、２－ヒドロキシプロピル（メタ）アクリレート、３－ヒドロキシプロピル（メタ）アクリレート、２－ヒドロキシブチル（メタ）アクリレート、３－ヒドロキシブチル（メタ）アクリレート、４－ヒドロキシブチル（メタ）アクリレート、１，２－シクロヘキサンジオールモノ（メタ）アクリレート、１，３－シクロヘキサンジオールモノ（メタ）アクリレート、１，４－シクロヘキサンジオールモノ（メタ）アクリレート、１，２－シクロヘキサンジメタノールモノ（メタ）アクリレート、１，３－シクロヘキサンジメタノールモノ（メタ）アクリレート、１，４－シクロヘキサンジメタノールモノ（メタ）アクリレート、１，２－シクロヘキサンジエタノールモノ（メタ）アクリレート、１，３－シクロヘキサンジエタノールモノ（メタ）アクリレート、１，４－シクロヘキサンジエタノールモノ（メタ）アクリレート、グリセリンモノ（メタ）アクリレート、グリセリンジ（メタ）アクリレート、トリメチロールプロパンモノ（メタ）アクリレート、トリメチロールプロパンジ（メタ）アクリレート、ペンタエリスリトールモノ（メタ）アクリレート、ペンタエリスリトールジ（メタ）アクリレート、ペンタエリスリトールトリ（メタ）アクリレート、ネオペンチルグリコールモノ（メタ）アクリレートなどの水酸基を有する（メタ）アクリレート及びこれら水酸基を有する（メタ）アクリレートとジカルボン酸又はその誘導体とを反応させて得られるカルボキシル基を有する（メタ）アクリレートなどが挙げられる。ここで使用可能なジカルボン酸としては、例えばシュウ酸、マロン酸、コハク酸、グルタル酸、アジピン酸、ピメリン酸、スベリン酸、アゼライン酸、セバシン酸、マレイン酸、フマル酸、フタル酸、テトラヒドロフタル酸、ヘキサヒドロフタル酸及びこれらの誘導体等が挙げられる。 Here, as the acrylic resin, for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 3-hydroxybutyl (Meth) acrylate, 4-hydroxybutyl (meth) acrylate, 1,2-cyclohexanediol mono (meth) acrylate, 1,3-cyclohexanediol mono (meth) acrylate, 1,4-cyclohexanediol mono (meth) acrylate, 1,2-cyclohexanedimethanol mono (meth) acrylate, 1,3-cyclohexanedimethanol mono (meth) acrylate, 1,4-cyclohexanedimethanol mono (meth) acrylate, 1,2-cyclohexane Ethanol mono (meth) acrylate, 1,3-cyclohexanediethanol mono (meth) acrylate, 1,4-cyclohexanediethanol mono (meth) acrylate, glycerin mono (meth) acrylate, glycerin di (meth) acrylate, trimethylolpropane mono ( Has a hydroxyl group such as meth) acrylate, trimethylolpropane di (meth) acrylate, pentaerythritol mono (meth) acrylate, pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, neopentyl glycol mono (meth) acrylate, etc. (Meth) acrylates and carboxyl-containing (meth) acrylates obtained by reacting these (meth) acrylates having hydroxyl groups with dicarboxylic acids or derivatives thereof Acrylate and the like. Examples of dicarboxylic acids that can be used here include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, maleic acid, fumaric acid, phthalic acid, and tetrahydrophthalic acid. , Hexahydrophthalic acid and derivatives thereof.
　また、特にアクリル樹脂としては、分子量が１００～１００００のポリエーテル、ポリエステル、ポリカーボネート、ポリ（メタ）アクリレートで（メタ）アクリル基を有する化合物、ヒドロキシル基を有する（メタ）アクリレート、ヒドロキシル基を有する（メタ）アクリルアミド等が挙げられる。 In particular, as the acrylic resin, polyethers, polyesters, polycarbonates having a molecular weight of 100 to 10,000, a compound having a (meth) acryl group as a poly (meth) acrylate, a (meth) acrylate having a hydroxyl group, and having a hydroxyl group ( (Meth) acrylamide and the like.
　マレイミド樹脂は、１分子内にマレイミド基を１つ以上含む化合物であり、加熱によりマレイミド基が反応することで３次元的網目構造を形成し、硬化する樹脂である。例えば、Ｎ，Ｎ’－（４，４’－ジフェニルメタン）ビスマレイミド、ビス（３－エチル－５－メチル－４－マレイミドフェニル）メタン、２，２－ビス［４－（４－マレイミドフェノキシ）フェニル］プロパンなどのビスマレイミド樹脂が挙げられる。マレイミド樹脂は、ダイマー酸ジアミンと無水マレイン酸の反応により得られる化合物、マレイミド酢酸、マレイミドカプロン酸といったマレイミド化アミノ酸とポリオールの反応により得られる化合物である。マレイミド化アミノ酸は、無水マレイン酸とアミノ酢酸又はアミノカプロン酸とを反応させることで得られる。ポリオールとしては、ポリエーテルポリオール、ポリエステルポリオール、ポリカーボネートポリオール、ポリ（メタ）アクリレートポリオールであってもよく、芳香族環を含まないものであってもよい。 Maleimide resin is a compound containing one or more maleimide groups in one molecule, and is a resin that forms a three-dimensional network structure and reacts when the maleimide groups react by heating. For example, N, N '-(4,4'-diphenylmethane) bismaleimide, bis (3-ethyl-5-methyl-4-maleimidophenyl) methane, 2,2-bis [4- (4-maleimidophenoxy) phenyl ] Bismaleimide resins such as propane. The maleimide resin is a compound obtained by reacting a dimer acid diamine with maleic anhydride, or a compound obtained by reacting a maleimidated amino acid such as maleimide acetic acid or maleimidocaproic acid with a polyol. A maleimidated amino acid is obtained by reacting maleic anhydride with aminoacetic acid or aminocaproic acid. The polyol may be a polyether polyol, a polyester polyol, a polycarbonate polyol, a poly (meth) acrylate polyol, or may not contain an aromatic ring.
　ここで、熱硬化性樹脂を配合する場合は、上記銅粒子および大粒径銅粒子の総量を１００質量部としたとき、１～２０質量部となるように配合される。熱硬化性樹脂が１質量部 以上であると熱硬化性樹脂による接着効果を十分に得ることができ、熱硬化性樹脂が２０質量部以下であると銅成分の割合を低下することなく、高熱伝導性を十分に確保することができ、熱放散性を向上させることができる。また、有機成分が多くなり過ぎず、光及び熱による劣化を抑え、その結果、発光装置の寿命を高めることができる。このような配合範囲とすることで、熱硬化性樹脂の接着性能を利用して、銅粒子及び／又は大粒径銅粒子相互の接触を低減し、かつ、接着層全体の機械的強度を保持することが容易にできる。 Here, when the thermosetting resin is blended, it is blended so as to be 1 to 20 parts by mass when the total amount of the copper particles and the large-diameter copper particles is 100 parts by mass. When the amount of the thermosetting resin is 1 part by mass or more, the adhesive effect by the thermosetting resin can be sufficiently obtained, and when the amount of the thermosetting resin is 20 parts by mass or less, high heat can be obtained without lowering the proportion of the copper component. Conductivity can be sufficiently ensured, and heat dissipation can be improved. In addition, the organic component is not excessively increased, and deterioration due to light and heat is suppressed. As a result, the life of the light emitting device can be increased. By setting the content within such a range, the contact between the copper particles and / or the large-diameter copper particles is reduced by utilizing the adhesive performance of the thermosetting resin, and the mechanical strength of the entire adhesive layer is maintained. Can be easily done.
（有機溶剤）
　有機溶剤は、還元剤として機能する溶剤であれば公知の溶剤を用いることができる。
　上記有機溶剤としては、アルコールであってもよく、例えば、脂肪族多価アルコールを挙げることができる。脂肪族多価アルコールとしては、例えば、エチレングリコール、ジエチレングリコール、プロピレングリコール、ジプロビレングリコール、１，４－ブタンジオール、グリセリン、ポリエチレングリコールなどのグリコール類などを挙げることができる。これらの有機溶剤は、単独で用いてもよく、２種以上を併用してもよい。 (Organic solvent)
As the organic solvent, a known solvent can be used as long as it functions as a reducing agent.
The organic solvent may be an alcohol, such as an aliphatic polyhydric alcohol. Examples of the aliphatic polyhydric alcohol include glycols such as ethylene glycol, diethylene glycol, propylene glycol, diprovylene glycol, 1,4-butanediol, glycerin, and polyethylene glycol. These organic solvents may be used alone or in combination of two or more.
　アルコールは、ペースト硬化（焼結）時の熱処理によって高温となり、還元力を増大させる。銅粒子中に一部存在している酸化銅及び金属基板上の酸化金属（例えば、酸化銅）がアルコールによって還元され、純粋な金属となる。その結果、接合用ペーストは、より緻密で導電性が高く、基板との密着性の高い硬化膜を形成する。また、半導体素子と金属基板に挟まれていることで、ペースト硬化時の熱処理中（沸点以上のペースト硬化温度）にアルコールが一部還流状態となり、より効率的に酸化金属が還元される。 Alcohol becomes high temperature by heat treatment at the time of paste curing (sintering) and increases reducing power. The copper oxide partially present in the copper particles and the metal oxide (eg, copper oxide) on the metal substrate are reduced by the alcohol to become a pure metal. As a result, the bonding paste forms a cured film that is denser, has higher conductivity, and has higher adhesion to the substrate. Further, since the paste is sandwiched between the semiconductor element and the metal substrate, the alcohol is partially refluxed during the heat treatment during paste curing (paste curing temperature higher than the boiling point), and the metal oxide is reduced more efficiently.
　有機溶剤の沸点は、具体的には、１００～３００℃であってもよく、１５０～２９０℃であってもよい。沸点が１００℃以上であると、常温であっても揮発性が高くなり過ぎず、分散媒の揮発による還元能力の低下を制御することができ、安定した接着強度を得ることができる。また、沸点が３００℃以下であると、硬化膜（導電膜）の焼結が生じやすく、緻密性に優れた膜を形成することができる。また、有機溶剤が揮発せず膜中に残存するのを制御することができる。 沸 Specifically, the boiling point of the organic solvent may be 100 to 300 ° C. or 150 to 290 ° C. When the boiling point is 100 ° C. or higher, the volatility does not become too high even at room temperature, and a reduction in the reducing ability due to the volatilization of the dispersion medium can be controlled, so that stable adhesive strength can be obtained. Further, when the boiling point is 300 ° C. or less, sintering of the cured film (conductive film) is likely to occur, and a film having excellent denseness can be formed. In addition, it is possible to control that the organic solvent does not evaporate and remains in the film.
　有機溶剤を配合する場合、その配合量は、上記銅粒子および大粒径銅粒子の総量を１００質量部としたとき、７～２０質量部であってもよい。７質量部以上であると粘度が高くなり過ぎず、作業性を向上させることができ、２０質量部以下であると粘度低下が制御され、ペースト中の銅の沈下を制御し、信頼性を高めることができる。 When the organic solvent is compounded, the compounding amount may be 7 to 20 parts by mass when the total amount of the copper particles and the large-diameter copper particles is 100 parts by mass. When the amount is 7 parts by mass or more, the viscosity does not become too high, and the workability can be improved. When the amount is 20 parts by mass or less, the decrease in viscosity is controlled, the sedimentation of copper in the paste is controlled, and the reliability is increased. be able to.
　本実施形態の接合用ペーストには、以上の各成分の他、この種の組成物に一般に配合される、硬化促進剤、ゴム、シリコーン等の低応力化剤、カップリング剤、消泡剤、界面活性剤、着色剤（顔料、染料）、各種重合禁止剤、酸化防止剤、溶剤、その他の各種添加剤を、必要に応じて配合することができる。これらの各添加剤はいずれも１種を使用してもよく、２種以上を混合して使用してもよい。 In the bonding paste of the present embodiment, in addition to the above components, a curing accelerator, a rubber, a low-stressing agent such as silicone, a coupling agent, a defoaming agent, which are generally blended with this type of composition, Surfactants, colorants (pigments, dyes), various polymerization inhibitors, antioxidants, solvents, and other various additives can be added as necessary. Each of these additives may be used alone or in combination of two or more.
　本実施形態の接合用ペーストは、上述した銅粒子、及び必要に応じて配合される大粒径銅粒子、熱硬化性樹脂、有機溶剤、カップリング剤等の添加剤等を十分に混合した後、さらにディスパース、ニーダー、３本ロールミル等により混練処理を行い、次いで、脱泡することにより、調製することができる。 The bonding paste of the present embodiment is obtained by sufficiently mixing the above-described copper particles, and, if necessary, additives such as large-diameter copper particles, a thermosetting resin, an organic solvent, and a coupling agent. Further, it can be prepared by performing a kneading treatment with a disperser, a kneader, a three-roll mill or the like, and then defoaming.
　本実施形態の接合用ペーストの粘度は、例えば、２０～３００Ｐａ・ｓであってもよく、４０～２００Ｐａ・ｓであってもよい。
　また、本実施形態の接合用ペーストの接合強度は、２５ＭＰａ以上であってもよく、３０ＭＰａ以上であってもよい。
　なお、上記粘度及び接合強度は、実施例に記載の方法により測定することができる。 The viscosity of the bonding paste of the present embodiment may be, for example, 20 to 300 Pa · s or 40 to 200 Pa · s.
Further, the bonding strength of the bonding paste of the present embodiment may be 25 MPa or more, or may be 30 MPa or more.
The viscosity and the bonding strength can be measured by the methods described in Examples.
　このようにして得られる本実施形態の接合用ペーストは、高熱伝導性、熱放散性に優れる。そのため、素子または放熱部材の基板等への接合材料として使用すると、装置内部の熱の外部への放散性が改善され、製品特性を安定させることができる。 接合 The bonding paste of the present embodiment obtained in this manner is excellent in high thermal conductivity and heat dissipation. Therefore, when used as a bonding material for the element or the heat dissipating member to the substrate or the like, the heat dissipation inside the device to the outside is improved, and the product characteristics can be stabilized.
＜半導体装置および電気・電子部品＞
　本実施形態の半導体装置および電気・電子部品は、上述の接合用ペーストを用いて接合されてなることから、信頼性に優れる。 <Semiconductor devices and electrical / electronic components>
Since the semiconductor device and the electric / electronic component of the present embodiment are joined using the above-mentioned joining paste, they have excellent reliability.
　本実施形態の半導体装置は、上述の接合用ペーストを用いて、半導体素子を素子支持部材となる基板上に接着してなるものである。すなわち、ここで接合用ペーストはダイアタッチペーストとして使用され、このペーストを介して半導体素子と基板とが接着し、固定される。 半導体 The semiconductor device of the present embodiment is one in which a semiconductor element is adhered to a substrate serving as an element supporting member using the above-mentioned bonding paste. That is, the bonding paste is used here as a die attach paste, and the semiconductor element and the substrate are bonded and fixed via the paste.
　ここで、半導体素子は、公知の半導体素子であればよく、例えば、トランジスタ、ダイオード等が挙げられる。さらに、この半導体素子としては、ＬＥＤ等の発光素子が挙げられる。また、発光素子の種類は特に制限されるものではなく、例えば、ＭＯＢＶＣ法等によって基板上にＩｎＮ、ＡｌＮ、ＧａＮ、ＩｎＧａＮ、ＡｌＧａＮ、ＩｎＧａＡｌＮ等の窒化物半導体を発光層として形成させたものが挙げられる。
　また、素子支持部材としては、銅、銅メッキ銅、ＰＰＦ（プリプレーティングリードフレーム）、ガラスエポキシ、セラミックス等の材料で形成された支持部材が挙げられる。 Here, the semiconductor element may be any known semiconductor element, and examples include a transistor and a diode. Furthermore, as this semiconductor element, a light emitting element such as an LED is cited. The type of the light-emitting element is not particularly limited, and examples thereof include a light-emitting element in which a nitride semiconductor such as InN, AlN, GaN, InGaN, AlGaN, and InGaAlN is formed as a light-emitting layer on a substrate by MOBVC or the like. Can be
Examples of the element supporting member include a supporting member formed of a material such as copper, copper-plated copper, PPF (pre-plating lead frame), glass epoxy, and ceramics.
　本実施形態の接合用ペーストは、金属メッキ処理されていない基材をも接合できる。このようにして得られた半導体装置は、実装後の温度サイクルに対する接続信頼性が従来に比べ飛躍的に向上したものとなる。また、電気抵抗値が十分小さく経時変化が少ないため、長時間の駆動でも出力の経時的減少が少なく長寿命であるという利点がある。 接合 The joining paste of the present embodiment can join a base material that has not been subjected to metal plating. In the semiconductor device obtained in this way, the connection reliability with respect to the temperature cycle after mounting is dramatically improved as compared with the related art. Further, since the electric resistance value is sufficiently small and the change with time is small, there is an advantage that the output does not decrease with time even when driven for a long time and the life is long.
　また、本実施形態の電気・電子部品は、上述の接合用ペーストを用いて、発熱部材に放熱部材を接着してなるものである。すなわち、ここで接合用ペーストは放熱部材接着用材料として使用され、該接合用ペーストを介して放熱部材と発熱部材とが接着し、固定される。 In addition, the electric / electronic component of the present embodiment is obtained by bonding a heat radiating member to a heat generating member by using the above-mentioned bonding paste. That is, the bonding paste is used as a material for bonding the heat radiating member, and the heat radiating member and the heat generating member are bonded and fixed via the bonding paste.
　発熱部材としては、上記半導体素子又は該半導体素子を有する部材でもよいし、それ以外の発熱部材でもよい。半導体素子以外の発熱部材としては、光ピックアップ、パワートランジスタ等が挙げられる。また、放熱部材としては、ヒートシンク、ヒートスプレッダー等が挙げられる。 (4) The heat generating member may be the above-described semiconductor element or a member having the semiconductor element, or may be another heat generating member. Examples of the heat generating member other than the semiconductor element include an optical pickup and a power transistor. In addition, examples of the heat radiating member include a heat sink and a heat spreader.
　このように、発熱部材に上述の接合用ペーストを用いて放熱部材を接着することで、発熱部材で発生した熱を放熱部材から効率良く外部へ放出することが可能となり、発熱部材の温度上昇を抑えることができる。なお、発熱部材と放熱部材とは、接合用ペーストを介して直接接着してもよいし、他の熱伝導率の高い部材を間に挟んで間接的に接着してもよい。 In this way, by bonding the heat radiating member to the heat generating member by using the above-described bonding paste, it is possible to efficiently release the heat generated by the heat generating member to the outside from the heat radiating member, thereby reducing the temperature rise of the heat generating member. Can be suppressed. The heat-generating member and the heat-dissipating member may be directly bonded via a bonding paste, or may be indirectly bonded with another member having high thermal conductivity interposed therebetween.
　次に実施例により、本開示を具体的に説明するが、本開示は、これらの例によってなんら限定されるものではない。 Next, the present disclosure will be specifically described with reference to examples, but the present disclosure is not limited to these examples.
（カルボン酸アミン塩の調製）
［調製例１］
　ノナン酸（東京化成工業（株）製、商品名：ノナン酸）４０ｍｍｏｌと、ヘキシルアミン（東京化成工業（株）製、商品名：ヘキシルアミン）４０ｍｍｏｌを、５０ｍＬのサンプルビンに入れ、アルミブロック式加熱撹拌機中、撹拌・混合すると、６０℃まで発熱した。続けて６０℃で１５分間撹拌・混合し、室温（２５℃）まで冷却することで、ノナン酸ヘキシルアミン塩（収量１０．３ｇ、収率９９．２％）を得た。 (Preparation of carboxylic acid amine salt)
[Preparation Example 1]
40 mmol of nonanoic acid (manufactured by Tokyo Chemical Industry Co., Ltd., trade name: nonanoic acid) and 40 mmol of hexylamine (manufactured by Tokyo Chemical Industry Co., Ltd., trade name: hexylamine) are placed in a 50 mL sample bottle, and an aluminum block type is used. When the mixture was stirred and mixed in a heating stirrer, heat was generated up to 60 ° C. Subsequently, the mixture was stirred and mixed at 60 ° C. for 15 minutes, and cooled to room temperature (25 ° C.) to obtain hexylamine nonanoate (yield 10.3 g, 99.2%).
（銅粒子の製造）
［合成例１］
　窒素導入管、熱電対、ジムロート、滴下漏斗を備えた２０００ｍＬの４つ口セパラブルフラスコに、銅化合物として酢酸銅（ＩＩ）一水和物（東京化成工業（株）製、商品名：酢酸銅（ＩＩ）一水和物）４ｍｏｌと、アミン化合物として調製例１で得たノナン酸ヘキシルアミン塩４０ｍｍｏｌと、有機溶剤としてブチルセロソルブ（東京化成工業（株）製）６００ｍＬを入れ、９０℃で５分間混合し、銅前駆体溶液とした。該銅前駆体溶液を室温（２５℃）まで冷却した後、１－プロパノール５００ｍＬに、還元性化合物としてヒドラジン一水和物（富士フイルム和光純薬（株）製、商品名：ヒドラジン一水和物）３ｍｏｌを溶解させた溶液を、銅前駆体溶液に滴下し、３０分間撹拌した。再び９０℃に昇温し、２時間加熱撹拌した後、室温（２５℃）まで冷却することにより、銅粒子を２質量％含有する銅粒子分散液を得た。 (Production of copper particles)
[Synthesis Example 1]
Copper acetate (II) monohydrate (manufactured by Tokyo Chemical Industry Co., Ltd., trade name: copper acetate) in a 2000 mL four-neck separable flask equipped with a nitrogen inlet tube, thermocouple, Dimroth, and dropping funnel 4 mol of (II) monohydrate), 40 mmol of hexylamine nonanoate obtained in Preparation Example 1 as an amine compound, and 600 mL of butyl cellosolve (manufactured by Tokyo Chemical Industry Co., Ltd.) as an organic solvent were added at 90 ° C. for 5 minutes. The mixture was mixed to obtain a copper precursor solution. After cooling the copper precursor solution to room temperature (25 ° C.), hydrazine monohydrate (trade name: hydrazine monohydrate, manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.) was added to 500 mL of 1-propanol as a reducing compound. ) The solution in which 3 mol was dissolved was dropped into the copper precursor solution, and the mixture was stirred for 30 minutes. The temperature was raised again to 90 ° C., and the mixture was heated and stirred for 2 hours, and then cooled to room temperature (25 ° C.) to obtain a copper particle dispersion containing 2% by mass of copper particles.
　密閉したＤｙＦ１５２／ｓ（商品名、水平濾板式濾過機、三菱化工機（株）製）のろ過膜に、流量２０ｋｇ／ｈｒ・ｍ２、圧力０．１ＭＰａで上記銅粒子分散液を供給し、さらに、エタノール１０００ｍＬを連続して供給し、エタノールで溶剤置換した銅粒子濃縮液を得た。エタノールで溶剤置換した銅粒子濃縮液をＤｙＦ１５２／ｓ中で、さらにジエチレングリコール（東京化成工業（株）製）１０００ｍＬを連続して供給し、ジエチレングリコールで溶剤置換した後、遠心分離（４０００ｒｐｍ）して、平均粒子径５０ｎｍの銅粒子濃縮液を得た。
　なお、得られた銅粒子の平均粒子径は、得られた銅粒子濃縮液を、遠心分離（４０００ｒｐｍ（１分間））し、固体物を得、その遠心分離した固体物を減圧乾燥し、走査電子顕微鏡（日本電子（株）製、商品名：ＪＳＭ－７６００Ｆ；ＳＥＭ）の観察画像に基づく任意に選択した１０個の銅粒子（ｎ＝１０）の平均値として算出した。 The above-mentioned copper particle dispersion is supplied to a sealed filtration membrane of DyF152 / s (trade name, horizontal filter plate type filter, manufactured by Mitsubishi Kakoki Co., Ltd.) at a flow rate of 20 kg / hr · m 2 and a pressure of 0.1 MPa, Further, 1000 mL of ethanol was continuously supplied to obtain a copper particle concentrated solution in which solvent was replaced with ethanol. In a DyF152 / s, 1000 mL of diethylene glycol (manufactured by Tokyo Kasei Kogyo Co., Ltd.) was continuously supplied from the copper particle concentrated solution with the solvent replaced with ethanol, and the solvent was replaced with diethylene glycol, followed by centrifugation (4000 rpm). A copper particle concentrate having an average particle diameter of 50 nm was obtained.
The average particle diameter of the obtained copper particles was determined by centrifuging the obtained copper particle concentrate (4000 rpm (1 minute)) to obtain a solid substance, drying the centrifuged solid substance under reduced pressure, and scanning. It was calculated as an average value of 10 arbitrarily selected copper particles (n = 10) based on an observation image of an electron microscope (manufactured by JEOL Ltd., trade name: JSM-7600F; SEM).
（実施例１）
　合成例１で得られた銅粒子が１００質量部、有機溶剤としてジエチレングリコール（東京化成工業（株）製）が１５質量部となるように調製し、ロールで混練し、接合用ペーストを得た。得られた接合用ペーストを以下の方法で評価した。その結果を表１に併せて示す。 (Example 1)
100 parts by mass of the copper particles obtained in Synthesis Example 1 and 15 parts by mass of diethylene glycol (produced by Tokyo Chemical Industry Co., Ltd.) as an organic solvent were prepared and kneaded with a roll to obtain a bonding paste. The obtained joining paste was evaluated by the following method. The results are shown in Table 1.
＜接合用ペーストの評価方法＞
［粘度］
　Ｅ型粘度計（東機産業（株）製、製品名：ＶＩＳＣＯＭＥＴＥＲ－ＴＶ２２、適用コーンプレート型ロータ：３°×Ｒ１７．６５）を用いて、２５℃、５ｒｐｍでの値を測定した。 <Evaluation method of bonding paste>
[viscosity]
The values were measured at 25 ° C. and 5 rpm using an E-type viscometer (manufactured by Toki Sangyo Co., Ltd., product name: VISCOMMETER-TV22, applicable cone plate type rotor: 3 ° × R17.65).
［ポットライフ］
　２５℃の恒温槽内に接合用ペーストを放置した時の粘度が初期粘度の０．７倍以上増粘するまでの日数を測定した。 [Pot life]
The number of days until the viscosity when the bonding paste was allowed to stand in a constant temperature bath at 25 ° C. increased to 0.7 times or more the initial viscosity was measured.
［電気抵抗］
　接合用ペーストを、ガラス基板（厚み１ｍｍ）にスクリーン印刷法により厚み２５μｍとなるように塗布し、２００℃、６０分間で硬化した。得られた焼結膜をロレスタＧＰ（商品名、（株）三菱ケミカルアナリティック製）を用い四端針法にて電気抵抗を測定した。 [Electric resistance]
The joining paste was applied to a glass substrate (1 mm in thickness) by screen printing so as to have a thickness of 25 μm, and was cured at 200 ° C. for 60 minutes. The electrical resistance of the obtained sintered film was measured by a four-point needle method using Loresta GP (trade name, manufactured by Mitsubishi Chemical Analytic).
＜半導体装置の評価方法＞
［接合強度］
　２ｍｍ×２ｍｍの接合面に金蒸着層を設けたシリコンチップを、接合用ペーストを用いて無垢の銅フレーム及びＰＰＦ（Ｎｉ－Ｐｄ／Ａｕめっきした銅フレーム）にマウントし、窒素（３％水素）雰囲気下、２００℃、６０分間で硬化した。硬化後及び吸湿処理（８５℃、相対湿度８５％、７２時間）後、それぞれについてＤＡＧＥ　４０００Ｐｌｕｓ（製品名、ノードソン（株）製）を用い、室温（２５℃）におけるダイシェア強度を測定した。 <Semiconductor device evaluation method>
[Joint strength]
A silicon chip provided with a gold vapor deposition layer on a bonding surface of 2 mm × 2 mm was mounted on a solid copper frame and a PPF (Ni-Pd / Au-plated copper frame) using a bonding paste, and nitrogen (3% hydrogen) was used. The composition was cured at 200 ° C. for 60 minutes in an atmosphere. After the curing and after the moisture absorption treatment (85 ° C., relative humidity 85%, 72 hours), the die shear strength at room temperature (25 ° C.) was measured for each using DAGE 4000Plus (product name, manufactured by Nordson Corporation).
［耐冷熱衝撃性］
　２ｍｍ×２ｍｍの接合面に金蒸着層を設けたシリコンチップを、接合用ペーストを用いて銅フレーム及びＰＰＦにマウントし、窒素（３％水素）雰囲気下、２００℃、６０分間で硬化した。これを京セラ（株）製、エポキシ封止材（商品名：ＫＥ－Ｇ３０００Ｄ）を用い、下記の条件で成形したパッケージを８５℃、相対湿度８５％、１６８時間吸湿処理した後、ＩＲリフロー処理（２６０℃、１０秒）及び冷熱サイクル処理（－５５℃から１５０℃まで昇温し、また－５５℃に冷却する操作を１サイクルとし、これを１０００サイクル）を行い、各処理後それぞれのパッケージの内部クラックの発生数を超音波顕微鏡（（株）日立パワーソリューション製、商品名：ＦｉｎｅＳＡＴ）で観察した。
　なお、表１に５個のサンプルについてクラックの発生したサンプル数を示す。 [Cold and thermal shock resistance]
A silicon chip having a bonding surface of 2 mm × 2 mm provided with a gold vapor deposition layer was mounted on a copper frame and a PPF using a bonding paste and cured at 200 ° C. for 60 minutes in a nitrogen (3% hydrogen) atmosphere. Using an epoxy sealing material (trade name: KE-G3000D) manufactured by Kyocera Corporation, a package molded under the following conditions was subjected to a moisture absorption treatment at 85 ° C. and a relative humidity of 85% for 168 hours, and then an IR reflow treatment ( 260 ° C., 10 seconds) and a cooling / heating cycle treatment (the operation of raising the temperature from −55 ° C. to 150 ° C. and cooling to −55 ° C. is one cycle, and this is 1000 cycles). The number of internal cracks was observed with an ultrasonic microscope (trade name: FineSAT, manufactured by Hitachi Power Solutions Co., Ltd.).
Table 1 shows the number of cracked samples for the five samples.
（成形条件）
　パッケージ：８０ｐＱＦＰ（１４ｍｍ×２０ｍｍ×２ｍｍ厚さ）
　チップ：裏面金メッキシリコンチップ
　リードフレーム：ＰＰＦ及び銅
　封止材の成形：１７５℃、２分間
　ポストモールドキュアー：１７５℃、８時間 (Molding condition)
Package: 80pQFP (14mm x 20mm x 2mm thickness)
Chip: Backside gold-plated silicon chip Lead frame: PPF and copper Molding of sealing material: 175 ° C, 2 minutes Post-mold cure: 175 ° C, 8 hours
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　以上の結果より、洗浄工程を密閉系で行う本開示の銅粒子の製造方法により得られる銅粒子を含む接合用ペーストは、塗膜状態、接合状態ともに高い焼結性が得られている。
　また、本開示の銅粒子の製造方法によって得られる銅粒子を含む接合用ペーストは、高い接合信頼性が得られることがわかった。したがって、該接合用ペーストを用いることにより信頼性に優れた半導体装置及び電気電子機器を得ることができる。 From the above results, the bonding paste containing copper particles obtained by the method for producing copper particles of the present disclosure in which the washing step is performed in a closed system has high sinterability in both the coating film state and the bonding state.
Moreover, it turned out that the joining paste containing copper particles obtained by the method for producing copper particles of the present disclosure has high joining reliability. Therefore, by using the bonding paste, a semiconductor device and an electric / electronic device having excellent reliability can be obtained.

Claims (7)

  1. 　銅化合物と、アミン化合物と、還元性化合物と、を有機溶剤中で混合し、銅粒子分散液を得る工程と、前記工程で得られた銅粒子分散液を溶剤洗浄し、前記銅粒子分散液から銅粒子を固液分離する洗浄工程とを有する銅粒子の製造方法であって、
    　前記洗浄工程を密閉系で実施する銅粒子の製造方法。     A step of mixing a copper compound, an amine compound, and a reducing compound in an organic solvent to obtain a copper particle dispersion, and washing the copper particle dispersion obtained in the step with a solvent, and washing the copper particle dispersion. And a washing step of solid-liquid separation of the copper particles from a copper particle production method,
    A method for producing copper particles, wherein the washing step is performed in a closed system.
  2. 　前記洗浄工程において、連続して溶剤置換及び洗浄する請求項１に記載の銅粒子の製造方法。 方法 The method for producing copper particles according to claim 1, wherein in the washing step, solvent replacement and washing are continuously performed.
  3. 　前記洗浄工程において、前記銅粒子を１～５０質量％含有する前記銅粒子分散液を流量５～１５００ｋｇ／ｈｒ・ｍ２、圧力０．０３～１．０ＭＰａでろ過膜に供給する請求項１または２に記載の銅粒子の製造方法。 The method according to claim 1, wherein, in the washing step, the copper particle dispersion containing 1 to 50% by mass of the copper particles is supplied to a filtration membrane at a flow rate of 5 to 1500 kg / hr · m 2 and a pressure of 0.03 to 1.0 MPa. 3. The method for producing copper particles according to 2.
  4. 　前記銅粒子の平均粒子径が１～１０００ｎｍである請求項１～３のいずれかに記載の銅粒子の製造方法。 方法 The method for producing copper particles according to any one of claims 1 to 3, wherein the average particle diameter of the copper particles is 1 to 1000 nm.
  5. 　請求項１～４のいずれかに記載の製造方法によって得られる銅粒子を含む接合用ペースト。 A bonding paste containing copper particles obtained by the method according to any one of claims 1 to 4.
  6. 　請求項５に記載の接合用ペーストを用いて接合されてなる半導体装置。 A semiconductor device joined by using the joining paste according to claim 5.
  7. 　請求項５に記載の接合用ペーストを用いて接合されてなる電気・電子部品。
          An electric / electronic component joined using the joining paste according to claim 5.
PCT/JP2019/030832 2018-08-31 2019-08-06 Production method for copper particles, bonding paste, semiconductor device, and electrical and electronic components WO2020044983A1 (en)

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