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KR-20260066779-A - Copper particles, method of manufacturing copper particles, conductive paste and substrate

KR20260066779AKR 20260066779 AKR20260066779 AKR 20260066779AKR-20260066779-A

Abstract

Copper particles having a value of 4.20 or less for the D 95 particle size ( H₂O ) divided by the D 10 particle size ( H₂O ), calculated by particle size measurement 1 below. [Particle Size Measurement 1] 0.1 g of copper particles were mixed with 1 mL of a 0.1 mass% aqueous solution of a dispersant, and after irradiating ultrasound within the device for 5 minutes using a laser diffraction/scattering particle size measuring device, the volume-based particle size distribution of the copper particles was measured to obtain D 10 particle size ( H₂O ), D 50 particle size ( H₂O ), and D 95 particle size ( H₂O ), respectively.

Inventors

  • 이시다 레이지
  • 스즈키 치사토

Assignees

  • 후루카와 기카이 긴조쿠 가부시키가이샤

Dates

Publication Date
20260512
Application Date
20240708
Priority Date
20230929

Claims (20)

  1. Copper particles having a value of 4.20 or less for the D 95 particle size ( H₂O ) divided by the D 10 particle size ( H₂O ), calculated by particle size measurement 1 below. [Particle Size Measurement 1] 0.1 g of copper particles were mixed with 1 mL of a 0.1 mass% aqueous solution of a dispersant, and after irradiating ultrasound within the device for 5 minutes using a laser diffraction/scattering particle size measuring device, the volume-based particle size distribution of the copper particles was measured to obtain D 10 particle size ( H₂O ), D 50 particle size ( H₂O ), and D 95 particle size ( H₂O ), respectively.
  2. In paragraph 1, Copper particles having a value of 1.10 or greater when the D 95 particle size ( H₂O ) is divided by the D 10 particle size ( H₂O ), calculated by the above particle size measurement 1.
  3. In paragraph 1 or 2, Copper particles, wherein the value obtained by subtracting the D 10 particle size (H 2 O) from the D 95 particle size (H 2 O) calculated by the above particle size measurement 1 is 0.05 μm or more and 1.50 μm or less.
  4. In any one of paragraphs 1 through 3, Copper particles having a D 95 particle diameter ( H₂O ) calculated by the above particle diameter measurement 1 of 0.20 μm or more and 2.00 μm or less.
  5. In any one of paragraphs 1 through 4, Copper particles having a D 10 particle diameter ( H₂O ) calculated by the above particle diameter measurement 1, of 0.05 μm or more and 0.50 μm or less.
  6. In any one of paragraphs 1 through 5, Copper particles having a D 50 particle diameter ( H₂O ) calculated by the above particle diameter measurement 1, of 0.10 μm or more and 1.00 μm or less.
  7. In any one of paragraphs 1 through 6, Copper particles having a D 50 particle diameter (img) calculated by particle diameter measurement 2 below of 0.10 μm or more and 1.00 μm or less. [Particle Size Measurement 2] The image obtained by the scanning electron microscope is analyzed to obtain the values of D 10 particle size (img), D 50 particle size (img), and D 90 particle size (img), respectively.
  8. In any one of paragraphs 1 through 7, Copper particles having a value of 1.50 or less for the D 50 particle size (H 2 O) calculated by the above particle size measurement 1 divided by the D 50 particle size (img) calculated by the particle size measurement 2 below. [Particle Size Measurement 2] The image obtained by the scanning electron microscope is analyzed to obtain the values of D 10 particle size (img), D 50 particle size (img), and D 90 particle size (img), respectively.
  9. In any one of paragraphs 1 through 8, Copper particles with a temperature of 200℃ or higher and a shrinkage rate of 1.0% calculated by the shrinkage rate measurement below. [Shrinkage Rate Measurement] 1 g of copper particles is weighed and filled into a cylindrical molding die with a diameter of 5 mm, and the copper particles are press-molded using a hydraulic press (discharge pressure 10 MPa). The pellet obtained by press-molding is crushed to obtain a granular sample. 0.67 g of the granular sample is weighed and filled into a cylindrical molding die with a diameter of 5 mm, and the granular sample is press-molded using a hydraulic press (discharge pressure 10 MPa) to obtain a cylindrical pellet with a diameter of 5 mm and a height of 5 mm as a sample for measurement. Using a thermomechanical analyzer, measurements are taken under conditions of Ar flow rate: 200 mL/min, measuring load: 10 mN, measuring temperature range: 23–1000℃, and heating rate: 5℃/min, and the temperature of a shrinkage rate of 1.0% is calculated.
  10. In any one of paragraphs 1 through 9, Copper particles having a tap density of 2.5 g/cm³ or more as measured in accordance with JIS Z2512:2012.
  11. In any one of paragraphs 1 through 10, Copper particles having an oxygen content of 0.70 mass% or less as measured in accordance with JIS H1067:2002.
  12. In any one of paragraphs 1 through 11, Copper particles having a carbon content of 1.50 mass% or less as calculated by the carbon content measurement below. [Carbon Content Measurement] 0.5 g of copper particles are weighed, and 1.5 g of tungsten powder, 0.5 g of iron powder, and 0.5 g of tin powder are added as combustion promoters. Using a carbon-sulfur analyzer, the carbon content is calculated by measuring under the conditions of an oxygen stream, flow rate: 3 L/min, combustion method: high-frequency heating, combustion time: 60 sec, and detection method: infrared absorption method.
  13. A method for manufacturing copper particles as described in any one of claims 1 to 12, A process (A) for drying copper particles while vibrating them is provided, A method for manufacturing copper particles, wherein the moisture content of the above-mentioned hydrated copper particles is 30 mass% or less when the total of the above-mentioned hydrated copper particles is 100 mass%.
  14. In Paragraph 13, A method for manufacturing copper particles, wherein the moisture content of the above-mentioned hydrated copper particles is 5 mass% or more when the total of the above-mentioned hydrated copper particles is 100 mass%.
  15. In paragraph 13 or 14, A method for manufacturing copper particles, wherein the copper particles are dried by a vibrating dryer in the above process (A).
  16. In any one of paragraphs 13 through 15, A method for manufacturing copper particles, wherein the drying temperature in the above process (A) is 30°C or higher and 100°C or lower.
  17. In any one of paragraphs 13 through 16, A method for manufacturing copper particles in the above process (A), wherein the drying time is 10 minutes or more and 24 hours or less.
  18. In any one of paragraphs 13 through 17, A process (B) for preparing a copper particle dispersion (a), and A method for manufacturing copper particles, further comprising a process (C) of obtaining the copper particles by separating the copper particle dispersion (a) from the solid to obtain the copper particles.
  19. In Paragraph 18, A method for manufacturing copper particles, wherein, in the above process (C), the copper particles are obtained by at least one method selected from centrifugation and filtration.
  20. In paragraph 18 or 19, The above process (B) comprises a process (B-1) of dispersing a divalent copper compound in a solvent in the presence of a dispersant, and A method for manufacturing copper particles, comprising a process (B-2) of reducing the above-mentioned divalent copper compound to obtain a copper particle dispersion (a).

Description

Copper particles, method of manufacturing copper particles, conductive paste and substrate The present invention relates to copper particles, a method for manufacturing copper particles, a conductive paste, and a substrate. As for technology regarding copper particles, for example, the technology described in Patent Document 1 can be cited. Patent Document 1 describes a copper powder manufactured by a wet method, wherein the absolute value of the zeta potential is 20 mV or more. According to the copper powder of Patent Document 1, it is stated that a copper powder with easy disintegration can be obtained, in which the residual of secondary particles is sufficiently reduced while reducing the burden of the disintegration and classification processes from the dry cake. Embodiments of the present invention are described below. Unless otherwise specified, "A to B" in numerical ranges represent A or greater and B or less. Copper particles are used, for example, as a conductive paste. Additionally, a conductive paste containing copper particles is used, for example, as a wiring conductor on a substrate. When a conductive paste containing copper particles is used as a wiring conductor on a substrate, the conductive paste may be filled into via holes in the substrate. For this reason, it is required to further improve the filling rate of copper particles in the via holes. The present invention provides copper particles with improved fillability, a method for manufacturing copper particles capable of obtaining copper particles with improved fillability, a conductive paste using said copper particles, and a substrate. In addition, according to the method for manufacturing copper particles of the present embodiment, the proportion of powdered copper particles among the copper particles obtained after process (A) can be further improved. Here, powdered copper particles refer to copper particles that are in a powdered state without undergoing crushing treatment such as a mortar and pestle. If the proportion of powdered copper particles among the copper particles obtained after process (A) is further improved, the manufacturing process can be further simplified, and the yield of copper particles can be further improved. [Copper particles] In the copper particles of this embodiment, the value obtained by dividing the D 95 particle size ( H₂O ) by the D 10 particle size ( H₂O ) is 4.20 or less. In the present embodiment, the value obtained by dividing the D 95 particle diameter ( H₂O ) of the copper particle by the D 10 particle diameter ( H₂O ) is preferably 4.10 or less, more preferably 4.00 or less, even more preferably 3.90 or less, and even more preferably 3.80 or less, from the perspective of further improving packing efficiency, and the lower limit value is not particularly limited, but may be, for example, 1.10 or more, 1.30 or more, 1.50 or more, or 1.80 or more. According to the inventors' review, it was discovered that the packing efficiency of copper particles is improved by adjusting the value obtained by dividing the D 95 particle size ( H₂O ) by the D 10 particle size ( H₂O ) to the above numerical range. That is, the present invention is the first to discover that the measure obtained by dividing the D 95 particle size ( H₂O ) of copper particles by the D 10 particle size ( H₂O ) is effective as a design indicator for improving the packing efficiency of copper particles. The value obtained by dividing the D 95 particle size ( H₂O ) by the D 10 particle size ( H₂O ) can be controlled, for example, by adjusting the drying conditions of the copper particles when manufacturing the copper particles, more specifically, by drying the copper particles while vibrating them, or by adjusting the moisture content of the copper particles before drying. The D 10 particle size ( H₂O ) of the copper particles of the present embodiment is preferably 0.05 μm or more, more preferably 0.10 μm or more, even more preferably 0.15 μm or more, even more preferably 0.20 μm or more, even more preferably 0.25 μm or more, and preferably 0.50 μm or less, more preferably 0.45 μm or less, and even more preferably 0.40 μm or less. The D 50 particle size ( H₂O ) of the copper particles of the present embodiment is preferably 0.10 μm or more, more preferably 0.20 μm or more, even more preferably 0.25 μm or more, even more preferably 0.30 μm or more, even more preferably 0.35 μm or more, even more preferably 0.40 μm or more, and preferably 1.00 μm or less, more preferably 0.80 μm or less, even more preferably 0.70 μm or less, even more preferably 0.65 μm or less, and even more preferably 0.60 μm or less. The D 95 particle size ( H₂O ) of the copper particles of the present embodiment is preferably 0.20 μm or more, more preferably 0.30 μm or more, even more preferably 0.40 μm or more, and even more preferably 0.50 μm or more, and, from the view of further improving packing efficiency, is preferably 2.00 μm or less, more preferably 1.80 μm or l