JP2016204733A - Manufacturing method of copper particle, copper particle, copper paste and semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a copper particle having good sinterability and excellent in storage stability.SOLUTION: There is provided a manufacturing method of a copper particle including a process for heating a precursor solution containing (A) at least one kind selected from a group consisting of CuO and CuO, (B) at least one kind selected from a group consisting of a tertiary amine compound, hydrazine hydrate and a secondary alcohol compound and (C) at least one kind selected from a group consisting of a primary amine compound and a secondary amine compound.SELECTED DRAWING: None

Description

  The present invention relates to a method for producing copper particles, copper particles, copper paste, and a semiconductor device. More specifically, a copper paste used for connecting semiconductor elements such as power semiconductors, LSIs, and light emitting diodes (LEDs) to support members such as lead frames, ceramic wiring boards, glass epoxy wiring boards, polyimide wiring boards, and the like The present invention relates to a semiconductor device obtained by using copper, copper particles used as raw material particles of the copper paste, and a method for producing copper particles.

When manufacturing a semiconductor device, a semiconductor element and a support member for mounting a semiconductor element are bonded to each other by mixing a binder resin such as an epoxy resin or a polyimide resin, a filler such as silver particles, a solvent, etc. There is a method of using this as an adhesive. In recent years, the power density (W · cm ⁻³ ) has increased with the high integration of semiconductor packages, and high heat dissipation is required for adhesives to ensure the operational stability of semiconductor elements. Moreover, since the use environment temperature of the semiconductor element is high, the adhesive is also required to have heat resistance. Furthermore, there is a need for an adhesive that does not contain Pb in order to reduce the environmental burden. From the above circumstances, sintered conductive pastes have been studied.

  As a conventional sintered conductive paste, a silver paste that forms a silver sintered body by using micro-sized to nano-sized silver particles as disclosed in Patent Documents 1 and 2, for example, has been proposed. (Prior art 1). Moreover, the manufacturing method of the copper particle used as the raw material of the copper paste and copper paste which is disclosed by patent documents 3-5 is proposed (prior art 2).

Japanese Patent No. 4353380 Japanese Patent No. 4414145 Japanese Patent No. 4496026 Japanese Patent No. 5519938 Japanese Patent No. 531147

  The problem with the sintered silver paste of Prior Art 1 is that the material cost of the silver paste is high because silver is an expensive metal. Even if the product requires a sintered silver paste in terms of performance, there is a problem that it is difficult to apply due to the high material cost.

  The problem with the copper paste of prior art 2 or the method for producing copper particles is that the storage stability of the copper particles and the copper paste is low.

  In view of the above problems related to the prior art, it is an object of the present invention to provide a method for producing copper particles having excellent sinterability and excellent storage stability. It is another object of the present invention to provide copper particles obtained by the method, a sintered copper paste containing copper particles, and a semiconductor device obtained using the copper paste.

The present invention is selected from the group consisting of (A) at least one selected from the group consisting of CuO and Cu ₂ O, and (B) a tertiary amine compound, hydrazine hydrate, and a secondary alcohol compound. Provided is a method for producing copper particles, comprising a step of heating a precursor solution containing at least one and (C) at least one selected from the group consisting of a primary amine compound and a secondary amine compound. To do.

  In the production method of the present invention, the boiling point of the compound (B) and / or (C) at atmospheric pressure is preferably less than 300 ° C, and more preferably less than 200 ° C.

  According to the present invention, the surface is coated with at least one selected from the group consisting of a primary amine compound and a secondary amine compound, and the average particle diameter is 0.01 to 1 μm. Produced copper particles are provided.

  The present invention provides a copper paste containing the copper particles of the present invention and a solvent.

  In the copper paste of the present invention, the solvent is at least one selected from the group consisting of a tertiary alcohol compound having a boiling point of 70 to 300 ° C at atmospheric pressure and an amine compound having a boiling point of 70 to 300 ° C at atmospheric pressure. Preferably there is.

The present invention is obtained by heating the copper paste of the present invention at 350 ° C. or less, and the volume resistivity, thermal conductivity, and adhesive strength are 1 × 10 ⁻⁵ Ω · cm or less and 30 W · m ^{−1, respectively.} -The sintered compact which is K- ¹ or more and 10 Mpa or more is provided.

  The present invention provides a semiconductor device in which a semiconductor element and a semiconductor element mounting support member are connected via the sintered body of the present invention.

  ADVANTAGE OF THE INVENTION According to this invention, it can provide the manufacturing method of the copper particle which has favorable sinterability and is excellent in storage stability. Moreover, according to this invention, the semiconductor device obtained using the copper particle obtained by the said method, the sintered copper paste containing a copper particle, and a copper paste can be provided.

The method for producing copper particles of the present invention comprises (A) at least one of CuO and Cu ₂ O as a copper source, and (B) a tertiary amine compound, hydrazine hydrate and a secondary alcohol compound as a reducing agent. A precursor solution is prepared by mixing at least one kind and (C) at least one of a primary amine and a secondary amine as a protective agent for copper particles, and this is heated to produce copper particles. is there. Since the copper particle dispersion after the reaction does not contain chemical species that cause copper oxidation or ionization, the obtained copper particles are excellent in storage stability. In addition, since a chemical species that causes copper oxidation or ionization is not used for the constituent material of the copper paste using the copper particles, the storage stability as the copper paste is excellent. Moreover, this copper paste is excellent also in sinterability. As a result, a sintered body excellent in connectivity between semiconductor members (semiconductor elements, semiconductor element mounting support members) and having high connection reliability is obtained, and physical properties such as thermal conductivity and electrical conductivity of the sintered body are also obtained. It becomes good. In the present invention, since the copper particles are used instead of the silver particles, the material cost can be reduced.

1 is a schematic cross-sectional view showing an embodiment of a semiconductor device according to the present invention. It is a schematic cross section which shows other embodiment of the semiconductor device which concerns on this invention.

  Hereinafter, an embodiment of the present invention will be described in detail.

The method for producing copper particles according to this embodiment includes (A) at least one selected from the group consisting of CuO and Cu ₂ O, and (B) a tertiary amine compound, hydrazine hydrate, and secondary alcohol. Heating a precursor solution containing at least one selected from the group consisting of compounds and (C) at least one selected from the group consisting of primary amine compounds and secondary amine compounds. .

As the copper source, at least one selected from the group consisting of (A) CuO and Cu ₂ O (in this specification, CuO and Cu ₂ O are referred to as “copper oxide”) is used. Copper oxide can be easily reduced by a reducing agent. At this time, the reducing agent is oxidized, but the oxidized reducing agent can be easily removed. On the other hand, the copper oxide which consists only of a copper atom and an oxygen atom has a high ratio of the copper contained per unit mass compared with another copper compound. This means that copper particles can be produced at a higher concentration when copper oxide is used than when other copper compounds are used. As a result, the throughput of copper particle production is improved. The concentration of copper oxide charged in one reaction is determined by determining the concentration of reducing agent and protective agent necessary for the reaction. In this embodiment, it is preferable that content of (A) component in a precursor solution is 5-40 mass%. In addition, in order to make copper oxide react with a reducing agent rapidly, it is desirable for copper oxide to be a powder form, and the average particle diameter of the copper oxide powder in that case is the copper particle (for example, average particle diameter) of suitable size Is preferably from 0.1 to 20 μm from the viewpoint of obtaining 0.01 to 1 μm.

  As the reducing agent, at least one selected from the group consisting of (B) a tertiary amine compound, hydrazine hydrate, and a secondary alcohol compound (this compound is referred to as “reducing agent” in this specification). Use. The boiling point of these reducing agents is desirably less than 300 ° C. More desirably, it is less than 200 ° C. In addition, the boiling point in this specification means the boiling point under atmospheric pressure (1013 hPa). When a tertiary amine compound and a secondary alcohol compound are used, since the reduction reaction of copper oxide is performed at 180 to 250 ° C., the boiling points of the tertiary amine compound and the secondary alcohol compound used are equal to or higher than the reaction temperature. It is desirable that Furthermore, in order to suppress oxidation or ionization of the copper particles after production and secondary reactions with other substances added as starting materials, the tertiary amine compounds are classified as functional groups such as It is desirable to include only a secondary amine group and no other functional groups. Examples of such tertiary amine compounds include tributylamine, tripentylamine, trihexylamine, and triheptylamine. Moreover, it is desirable that the secondary alcohol compound also contains only a secondary alcohol group as a functional group and no other functional group for the same reason. Examples of such secondary alcohol compounds include 2-octanol, 3-octanol, 4-octanol, 2-nonanol, 3-nonanol, 4-nonanol, 5-nonanol, 2-decanol, 3-decanol, 4- Examples include decanol, 5-decanol, and 7-ethyl-2-methyl-4-undecanol. On the other hand, examples of the hydrazine hydrate include hydrazine monohydrate. When hydrazine hydrate is used, the reduction reaction can be performed at 40 to 100 ° C. A tertiary amine compound and hydrazine hydrate may be mixed and used.

  The concentration of the reducing agent may be set as an amount capable of reducing the stoichiometric amount of copper oxide. At that time, copper oxide can be efficiently reduced by adding a reducing agent slightly in excess of the necessary minimum amount. Therefore, the content of the component (B) in the precursor solution is preferably 10 to 60% by mass.

  The reducing agent after the reaction can be easily removed by purification treatment. The reducing agent after the reaction can be removed by decantation, filtration, or the like. As a cleaning solvent used at that time, it is desirable to use a solvent that does not oxidize copper particles, for example, a mixed solution of hexane and acetone.

  As the protective agent, at least one selected from the group consisting of (C) a primary amine compound and a secondary amine compound (this compound is referred to as “protective agent” in this specification) is used. The boiling point of these protective agents at atmospheric pressure is desirably less than 300 ° C. More desirably, it is less than 200 ° C.

  The surface of the deposited copper particles is coated with at least one selected from the group consisting of (C) a primary amine compound and a secondary amine compound. When these amine compounds coat the copper surface, the copper particles can be present in a fine particle state. This amine compound is detached from the copper surface by heating at 350 ° C. or lower. When the amine compound is eliminated, a clean copper surface is exposed. The exposed copper surface is very active, and when these copper particles come into contact with each other, copper atoms diffuse and grow into larger copper particles. This copper particle growth phenomenon is called sintering. The copper particles of this embodiment are sintered at a heating temperature of 350 ° C. or less to form a sintered body.

The chemical structure of the protective agent is preferably a primary amine compound or a secondary amine compound consisting only of a hydrocarbon group and an amine group (—NH ₂ , —NH—). Specific examples of the amine compound of component (C) include pentylamine, hexylamine, heptylamine, octylamine, decylamine, dodecylamine, dibutylamine, dihexylamine, bis (2-ethylhexyl) amine and the like.

  The amount of the (C) component amine compound is desirably an amount that can sufficiently cover the produced copper particles. In order to obtain fine copper particles, it is necessary to quickly coat the copper particles produced in the precursor solution with an amine compound to suppress the growth of the copper particles. Therefore, it is desirable that the concentration of the amine compound is high. However, when the concentration of the amine compound is set high, the concentration of copper particles in the precursor solution is relatively reduced. This means that the copper particles that can be produced per unit volume and unit time are reduced. Therefore, it is desirable to set the concentration of the amine compound so as not to impair the throughput of the copper particles. For this reason, the content of the component (C) in the precursor solution is preferably 1 to 10% by mass.

  In addition, the amine compound of (C) component adsorbed excessively with respect to the copper particles can be removed by decantation or filtration. As a cleaning solvent used at that time, it is desirable to use a solvent that does not oxidize copper particles, for example, a mixed solution of hexane and acetone.

  In this embodiment, the component (A), the component (B), and the component (C) are mixed in a reaction vessel to prepare a precursor solution, and this is heated while stirring to reduce the copper oxide. Copper particles are deposited. At that time, in order to suppress oxidation of the copper particles, it is desirable to perform the reaction in an oxygen-free atmosphere such as a nitrogen atmosphere or an Ar atmosphere. The reaction temperature is preferably 40 to 250 ° C., although it depends on the type of reducing agent used. In order that the compound of (B) component and (C) component may serve as a solvent, it is desirable to react at the temperature exceeding the melting | fusing point of at least 1 type of the compound of (B) component and (C) component. When the compound of component (B) or component (C) boils at the reaction temperature, it is necessary to perform heating while refluxing. What is necessary is just to set reaction time as time when all copper oxides change to a copper particle, for example, can be 0.1 to 2 hours.

  The average particle diameter of the copper particles is preferably 0.01 to 1 μm. The copper particles after the protective agent is detached are more easily sintered as the surface energy of the copper particles is larger. This surface energy increases as the ratio of the surface area to the volume of the copper particles increases. As the average particle diameter of the copper particles increases, the ratio of the surface area per volume decreases, resulting in a decrease in surface energy and difficulty in sintering. In order to contribute to the sintering, the average particle diameter of the copper particles is desirably 1 μm or less. A more desirable average particle diameter of the copper particles is 0.01 to 0.1 μm. The thickness of the sintered body (sintered film) assumed as the die bond application of the present embodiment is 10 to 200 μm. When the average particle diameter of the copper particles is less than 0.1 μm, it becomes difficult to form a sintered body having an appropriate thickness. In addition, let the average particle diameter of the copper particle in this specification be an average value of the square root of the area of each particle | grain when 50 particles are planarly viewed using SEM.

  The shape of the copper particles obtained by the production method of the present embodiment is usually spherical, but both spherical and non-spherical copper particles can be used as a raw material for the copper paste, and particles of two or more types are used. It is also possible to mix and use.

  The solvent in the copper paste of this embodiment is preferably a tertiary alcohol compound having a boiling point of 70 to 300 ° C. at atmospheric pressure or an amine compound having a boiling point of 70 to 300 ° C. at atmospheric pressure. Moreover, these can also be used in combination.

  Since tertiary alcohol is difficult to oxidize, when copper paste is stored at room temperature, the possibility of reoxidizing copper particles is low. Moreover, since an amine compound has reducibility, it does not oxidize copper particles. By using these solvents, reoxidation of copper particles can be suppressed, and a copper paste excellent in storage stability can be obtained.

  The boiling point of the solvent is desirably 70 to 300 ° C, more desirably 130 to 300 ° C, and further desirably 150 to 250 ° C. When the boiling point of the solvent is 70 ° C. or higher, the solvent can be prevented from volatilizing at the room temperature (25 ° C.) when the copper paste is used, and as a result, the viscosity stability of the copper paste, applicability, etc. can be ensured. Further, when the boiling point of the solvent is 300 ° C. or less, the temperature at which the semiconductor element is connected to the semiconductor element mounting support member can be suppressed from remaining inside the copper sintered body without evaporating the solvent, As a result, the characteristics of the copper sintered body can be kept better.

  Examples of the solvent in this embodiment include octylamine, decylamine, dodecylamine, and 3,7-dimethyl-3-octanol.

  The amount of the solvent in the copper paste is desirably less than 20 parts by mass in 100 parts by mass of the copper paste. When the solvent is less than 20 parts by mass, volume shrinkage accompanying the volatilization of the solvent when the copper paste is sintered can be suppressed, and the denseness of the formed sintered body can be further improved. Further, the amount of the solvent can be appropriately determined according to the viscosity or thixotropy of the target copper paste, but the amount of the solvent is preferably at least 10 parts by mass.

  The copper paste according to this embodiment is an additive such as metal particles other than copper particles, a binder resin and a curing agent, a reactive diluent for the binder resin, and the like within a range that does not impair the sinterability and storage stability of the copper paste. May be included.

  Examples of metal particles other than copper particles include tin, zinc, gold, and silver particles. Effects such as improved mechanical properties of the sintered body and improved adhesion strength to the adherend metal can be expected. Examples of the resin component include epoxy resin, phenol resin, unsaturated polyester resin, saturated polyester resin, polyamide resin, polyimide resin, polyamide resin, polyimide resin, polyamideimide resin, acrylic resin, etc. Curing accelerators such as imidazole and amines are used. Examples of the reactive diluent include alkyl monoglycidyl ether, alkyl diglycidyl ether, and alkylphenol monoglycidyl ether.

  In order to manufacture the copper paste according to the present embodiment, for example, copper particles, a solvent, and (optionally, further additives) are collectively or divided into a stirrer, a raid device, a three roll, a planetary. A dispersing / dissolving device such as a mixer may be appropriately combined, and heated, if necessary, mixed, dissolved, granulated kneaded or dispersed. Thereby, a uniform copper paste can be obtained.

  As a method for heating and sintering the copper paste according to this embodiment, a known method can be used. In addition to external heating by a heater, an ultraviolet lamp, laser, microwave, or the like can be suitably used. The heating temperature of the copper paste is preferably equal to or higher than the temperature at which the copper particle protective agent and solvent are desorbed from the system. Specifically, the range of the heating temperature is desirably 150 ° C. or more and 350 ° C. or less, and more desirably 250 ° C. or more and 350 ° C. or less. The sintering atmosphere is desirably a reducing atmosphere using hydrogen, formic acid or the like, or an inert atmosphere such as nitrogen or Ar in order to suppress copper oxidation. Further, it is desirable to apply pressure during sintering. By pressurizing, a denser copper sintered body is obtained, and thermal conductivity and electrical conductivity are improved. In addition, strong bonding to the adherend can be achieved. The applied pressure may be determined within a range where the semiconductor member to be connected is not damaged. The sintering time can be about 10 to 120 minutes.

  The process at the time of heating a copper paste can be determined suitably. In particular, when sintering is performed at a temperature exceeding the boiling point of the solvent, preheating is performed at a temperature lower than the boiling point of the solvent, and after sintering the solvent to some extent in advance, a denser sintered body is obtained. Easy to get. The rate of temperature increase when heating the copper paste is not particularly limited when sintering is performed below the boiling point of the solvent. In the case of sintering at a temperature exceeding the boiling point of the solvent, it is desirable to set the heating rate to 1 ° C./second or less, or to perform a preheating step. The preheating step is also desirably performed in a reducing atmosphere or an inert atmosphere for the purpose of suppressing copper oxidation.

The sintered body (sintered film) obtained by sintering the copper paste as described above has a volume resistivity, thermal conductivity, and adhesive strength of 1 × 10 ⁻⁵ Ω · cm or less, 30 W · A sintered body of m ⁻¹ · K ⁻¹ or higher and 10 MPa or higher is desirable.

The volume resistivity is more preferably 8 × 10 ⁻⁶ Ω · cm or less from the viewpoint of conductivity required when a die bond material is used. The lower limit of the volume resistivity is not particularly limited, but can be about 5 × 10 ⁻⁶ Ω · cm. The thermal conductivity is more preferably 50 W · m ⁻¹ · K ⁻¹ or more from the viewpoint of heat dissipation required when a die bond material is used. The upper limit of the thermal conductivity is not particularly limited, but can be about 100 W · m ⁻¹ · K ⁻¹ . The adhesive strength is more preferably 15 MPa or more from the viewpoint of bondability between a chip and a semiconductor member such as a substrate, which is required when a die bond material is used. The upper limit of the adhesive strength is not particularly limited, but can be about 30 MPa.

  In the semiconductor device according to the present embodiment, a semiconductor element and a semiconductor element mounting support member are connected via a sintered body formed by sintering the copper paste according to the present embodiment.

  FIG. 1 is a schematic cross-sectional view showing an example of a semiconductor device according to the present embodiment. As shown in FIG. 1, a semiconductor device 10 includes a lead frame 2a (heat radiating body) that is a semiconductor element mounting support member, lead frames 2b and 2c, and a sintered body 3 of copper paste according to the present embodiment. The semiconductor element 1 connected to the lead frame 2a and the mold resin 5 for molding them are provided. The semiconductor element 1 is connected to lead frames 2b and 2c through two wires 4, respectively.

  FIG. 2 is a schematic cross-sectional view showing another example of the semiconductor device according to the present embodiment. As shown in FIG. 2, the semiconductor device 20 includes a substrate 6, a lead frame 7 which is a semiconductor element mounting support member formed so as to surround the substrate 6, and a sintered body of copper paste according to the present embodiment. LED chip 8 which is a semiconductor element connected on lead frame 7 through 3 and translucent resin 9 which seals these. The LED chip 8 is connected to the lead frame 7 via the wire 4.

  In these semiconductor devices, for example, a copper paste is applied on a semiconductor element mounting support member by a dispensing method, a screen printing method, a stamping method, etc., the semiconductor element is mounted on a portion where the copper paste is applied, and a heating device is installed. By using and sintering the copper paste, the semiconductor element and the semiconductor element mounting support member can be connected to each other through the sintered body. Moreover, a semiconductor device is obtained by performing a wire-bonding process and a sealing process after sintering the copper paste.

  As the support member for mounting a semiconductor element, for example, a lead frame such as a 42 alloy lead frame, a copper lead frame, a palladium PPF lead frame, a glass epoxy substrate (a substrate made of glass fiber reinforced epoxy resin), a BT substrate (cyanate monomer and its component) And an organic substrate such as a BT resin-containing substrate made of an oligomer and bismaleimide.

  Examples of the semiconductor element include IGBT (insulated gate bipolar transistor), MOSFET (field effect transistor), SBD (Schottky barrier diode), GTO (gate turn-off thyristor), and the like.

  Hereinafter, the present invention will be described in more detail with reference to examples. The present invention is not limited by these examples.

  Measurement of each characteristic in each example and comparative example was performed as follows.

(1) Phase identification of copper particles (XRD measurement)
About 100 mg of copper particles were placed on a glass cell for XRD measurement, and this was set in a sample holder of a powder X-ray diffractometer (Rigaku CN4036). CuKα rays were generated at an acceleration voltage of 40 kV and a current of 20 mA, and were converted to monochromatic light using a graphite monochromator to obtain a measurement source. The diffraction pattern of the copper particles was measured in the range of 2θ = 5 ° to 90 °.

(2) Particle observation Copper particles were fixed on a carbon tape, platinum was vapor-deposited with an ion sputtering apparatus (Hitachi High-Technologies Corporation, E1045), and this was observed with a scanning electron microscope (PHILIPS, XL30). In measuring the average particle diameter, 50 particles were viewed in plan, and the average value of the square root of the area of each particle was taken.

(3) Adhesive strength (die shear strength)
Copper paste was applied on a Cu plate (25 mm × 19 mm × 3 mm) using a printing mask (2.2 mm × 2.2 mm × 0.1 mm). A Cu plate (2 mm × 2 mm × 0.4 mm) was placed thereon. This was heated and pressurized in a nitrogen atmosphere at 350 ° C., 10 MPa, and 10 minutes to prepare a test piece. The adhesive strength of the obtained copper sintered body was evaluated by die shear strength (MPa). Using a universal bond tester (manufactured by Daisy Japan Co., Ltd., 4000 series), a Cu plate (2 mm x 2 mm x 0.4 mm) was pressed in the horizontal direction at a measurement speed of 500 µm · s ^-1 and a measurement height of 200 µm, and sintered. The die shear strength (MPa) of was measured.

(4) Thermal conductivity The copper paste was preheated at 120 ° C. for 30 minutes in a nitrogen atmosphere, and further heated at 350 ° C. for 1 hour to obtain a sintered body (about 10 mm × 10 mm × 0.3 mm). The thermal diffusivity of this sintered body was measured by a laser flash method (LFA 447 manufactured by Netch Co., Ltd., 25 ° C.), and this thermal diffusivity and the ratio obtained by a differential scanning calorimeter (Pyris 1 manufactured by PerkinElmer Co.) were obtained. From the product of the heat capacity and the sintered density, the thermal conductivity [W · m ⁻¹ · K ⁻¹ ] of the sintered body at 25 ° C. was calculated.
Thermal conductivity (W · m ⁻¹ · K ⁻¹ ) = specific heat capacity (J · g ⁻¹ · K ⁻¹ ) × thermal diffusivity (mm ² · s ⁻¹ ) × sintering density (g · cm ⁻³⁾ )

(5) Volume resistivity A copper paste is applied on a glass plate, preheated at 120 ° C. for 30 minutes in a nitrogen atmosphere, and further heated at 350 ° C. for 1 hour to obtain a sintered body (about 1 mm × 50 mm × 0.03 mm). ) The volume resistivity (Ω · cm) of this sintered body was measured by a four-terminal method (Advantest Corporation, R687E DIGITAL MULTITIMER).

  Copper particles used in each example and comparative example were prepared as follows.

(Copper particles 1)
Copper particles 1 were synthesized by the following procedure. Cu ₂ O (Wako Pure Chemical Industries, Ltd.) as a copper source, decylamine (Wako Pure Chemical Industries, Ltd., boiling point 220.5 ° C.) as a protective agent, and tributylamine (Wako Pure Chemical Industries, Ltd., boiling point 217 ° C.) as a reducing agent )It was used. These reagents were added to the eggplant flask at the mixing ratio shown in Table 1. The processing solution (precursor solution) was heated at 200 ° C. for 5 hours in a nitrogen atmosphere while stirring with a magnetic stirrer at about 700 revolutions / minute (rpm). About 250 mL of acetone and 250 mL of hexane were added to the solution after the treatment, the supernatant was removed, and the precipitated copper particles were collected. The copper particles were heated in a nitrogen atmosphere at 40 ° C. for 5 hours and dried.

  When the XRD measurement of this copper particle was performed, the XRD pattern which shows that it was a single phase of metallic copper was obtained. Moreover, it confirmed that the copper particle was spherical and the average particle diameter of the copper particle was about 300 nm.

(Copper particles 2)
The copper particles 1 were transferred to a glass petri dish and stored for 30 days in a nitrogen desiccator at a temperature of 25 ° C. and a humidity of 30%.

(Copper particles 3)
Copper particles 3 were synthesized by the following procedure. CuO (Wako Pure Chemical Industries, Ltd.) as a copper source, dibutylamine (Wako Pure Chemical Industries, Ltd., boiling point 159 ° C.) as a protective agent, hydrazine monohydrate (Wako Pure Chemical Industries, Ltd., boiling point of about 120) as a reducing agent ° C) was used. These reagents were added to the eggplant flask at the mixing ratio shown in Table 1. The treated solution (precursor solution) was heated at 80 ° C. for 2 hours in a nitrogen atmosphere while being stirred with a magnetic stirrer at about 700 revolutions / minute (rpm). About 250 mL of acetone and 250 mL of hexane were added to the solution after the treatment, the supernatant was removed, and the precipitated copper particles were collected. The copper particles were heated in a nitrogen atmosphere at 40 ° C. for 5 hours and dried.

  When the XRD measurement of this copper particle was performed, the XRD pattern which shows that it was a single phase of metallic copper was obtained. Moreover, it confirmed that the copper particle was spherical and the average particle diameter of the copper particle was about 200 nm.

(Copper particles 4)
The copper particles 3 were transferred to a glass petri dish and stored for 30 days in a nitrogen desiccator at a temperature of 25 ° C. and a humidity of 30%.

(Copper particles C1)
Copper particles were prepared in the same procedure as the copper particles 3 except that copper acetate (Wako Pure Chemical Industries, Ltd.) was used as the copper source. The composition is as shown in Table 1. When the XRD measurement of this copper particle was performed, the XRD pattern which shows that it was a single phase of metallic copper was obtained. Moreover, it confirmed that the copper particle was spherical and the average particle diameter of the copper particle was about 250 nm. The copper particles were transferred to a glass petri dish and stored for 30 days in a nitrogen desiccator having a temperature of 25 ° C. and a humidity of 30%. When the XRD measurement of the copper particle after a preservation | save was performed, the XRD pattern of metallic copper and CuO was obtained.

(Copper particle C2)
Copper particles were produced in the same procedure as the copper particles 3 except that dodecanoic acid (Wako Pure Chemical Industries, Ltd., boiling point 298 ° C.) was used as the protective agent. The composition is as shown in Table 1. When the XRD measurement of this copper particle was performed, the XRD pattern which shows that it was a single phase of metallic copper was obtained. Moreover, it confirmed that the copper particle was spherical and the average particle diameter of the copper particle was about 200 nm. The copper particles were transferred to a glass petri dish and stored for 30 days in a nitrogen desiccator having a temperature of 25 ° C. and a humidity of 30%. When the XRD measurement of the copper particle after a preservation | save was performed, the XRD pattern of metallic copper and CuO was obtained.

(Copper particle C3)
Copper particles were prepared in the same procedure as copper particles 1 except that diethylene glycol (Wako Pure Chemical Industries, Ltd., boiling point 245 ° C.) was used as the reducing agent. The composition is as shown in Table 1. When the XRD measurement of this copper particle was performed, the XRD pattern which shows that it was a single phase of metallic copper was obtained. Moreover, it confirmed that the copper particle was spherical and the average particle diameter of the copper particle was about 500 nm. The copper particles were transferred to a glass petri dish and stored for 30 days in a nitrogen desiccator having a temperature of 25 ° C. and a humidity of 30%. When the XRD measurement of the copper particle after a preservation | save was performed, the XRD pattern of metallic copper and CuO was obtained.

  Using the copper particles prepared as described above, the following examples and comparative examples were performed.

Example 1
Decylamine (Wako Pure Chemical Industries, Ltd., boiling point 220.5 ° C.) was used as the solvent. Copper particles and a solvent were kneaded for 15 minutes with a roughing machine at a blending ratio shown in Table 2 to prepare a copper paste. The characteristics using this copper paste are shown in Table 3.

(Example 2)
A copper paste was prepared in the same procedure as in Example 1. Table 2 shows the composition of the copper paste. The characteristics using this copper paste are shown in Table 3.

Example 3
The copper paste of Example 2 was transferred to a plastic bottle and stored for 30 days in a nitrogen desiccator at a temperature of 25 ° C. and a humidity of 30%. Table 2 shows the composition of the copper paste. The characteristics using this copper paste are shown in Table 3.

Example 4
3,7-dimethyl-3-octanol (Wako Pure Chemical Industries, Ltd., boiling point 196 ° C.) was used as the solvent. Other than that, the copper paste was produced in the same procedure as Example 1. Table 2 shows the composition of the copper paste. The characteristics using this copper paste are shown in Table 3.

(Example 5)
A copper paste was prepared in the same procedure as in Example 4. Table 2 shows the composition of the copper paste. The characteristics using this copper paste are shown in Table 3.

(Example 6)
The copper paste of Example 5 was transferred to a plastic bottle and stored for 30 days in a nitrogen desiccator at a temperature of 25 ° C. and a humidity of 30%. The characteristics using this copper paste are shown in Table 3.

(Comparative Examples 1-3)
A copper paste was prepared in the same procedure as in Example 1. Table 2 shows the composition of the copper paste. The characteristics using this copper paste are shown in Table 3.

  DESCRIPTION OF SYMBOLS 1 ... Semiconductor element, 2a, 2b, 2c ... Lead frame, 3 ... Sintered body, 4 ... Wire, 5 ... Mold resin, 6 ... Board | substrate, 7 ... Lead frame, 8 ... LED chip, 9 ... Translucent resin, 10, 20... Semiconductor device.

Claims (8)

(A) at least one selected from the group consisting of CuO and Cu ₂ O;
(B) at least one selected from the group consisting of a tertiary amine compound, hydrazine hydrate and a secondary alcohol compound;
(C) at least one selected from the group consisting of a primary amine compound and a secondary amine compound;
The manufacturing method of a copper particle provided with the process of heating the precursor solution containing this.   The manufacturing method of Claim 1 whose boiling point in the atmospheric pressure of the compound of said (B) and / or said (C) is less than 300 degreeC.   The manufacturing method of Claim 1 or 2 whose boiling point in the atmospheric pressure of the compound of said (B) and / or said (C) is less than 200 degreeC.   The surface is coated with at least one selected from the group consisting of a primary amine compound and a secondary amine compound, and has an average particle diameter of 0.01 to 1 µm. The copper particle manufactured by the manufacturing method.   A copper paste containing the copper particles according to claim 4 and a solvent.   The said solvent is at least 1 type selected from the group which consists of a tertiary alcohol compound whose boiling point in atmospheric pressure is 70-300 degreeC, and an amine compound whose boiling point in atmospheric pressure is 70-300 degreeC. Copper paste. The copper paste according to claim 5 or 6 is obtained by heating at 350 ° C. or less, and the volume resistivity, thermal conductivity, and adhesive strength are 1 × 10 ⁻⁵ Ω · cm or less, 30 W · m ⁻¹ ·, respectively. A sintered body having K- ¹ or more and 10 MPa or more.   The semiconductor device with which the semiconductor element and the supporting member for semiconductor element mounting are connected through the sintered compact of Claim 7.