US 12,646,635 B2Granted

Silver powder and method for producing same

AssigneeDowa Electronics Materials Co., Ltd.

InventorMasanori Fujii

Life of this patent

Estimating the term…

Loading patent…

Abstract

There are provided a silver powder, which is able to form an electrically conductive film having a lower resistance value than that of conventional electrically conductive films when the silver powder is used as the material of an electrically conductive paste which is fired to form the electrically conductive film, and a method for producing the same. A first silver powder having one peak or more, at each of which a frequency is a local maximum value in a volume-based particle size distribution obtained by measuring the first silver powder in a dry process by means of a laser diffraction particle size analyzer, is mixed with a second silver powder having two peaks or more, at each of which a frequency is a local maximum value in a volume-based particle size distribution obtained by measuring the second silver powder in a dry process by means of a laser diffraction particle size analyzer, to produce a silver powder having three peaks or more, at each of which a frequency is a local maximum value in a volume-based particle size distribution obtained by measuring the silver powder in a dry process by means of a laser diffraction particle size analyzer, the silver powder having one peak, at which a frequency is a local maximum value in a volume-based particle size distribution obtained by measuring the silver powder in a wet process by means of a laser diffraction scattering particle size analyzer.

Claims9

Dependent claims

A method for producing a silver powder of silver, which is a mixed powder, the method comprising the steps of:

providing a first silver powder of silver having one peak or more, at each of which a frequency is a local maximum value in a volume-based particle size distribution obtained by measuring the first silver powder in a dry process by means of a laser diffraction particle size distribution analyzer;
providing a second silver powder of silver having two peaks or more, at each of which a frequency is a local maximum value in a volume-based particle size distribution obtained by measuring the second silver powder in a dry process by means of the laser diffraction particle size distribution analyzer;
and
mixing the first silver powder with the second silver powder to produce the mixed silver powder having three peaks or more, at each of which a frequency is a local maximum value in a volume-based particle size distribution obtained by measuring the mixed silver powder in a dry process by means of the laser diffraction particle size distribution analyzer, the mixed silver powder having one peak, at which a frequency is a local maximum value in a volume-based particle size distribution obtained by measuring the mixed silver powder in a wet process by means of a laser diffraction scattering particle size distribution analyzer,
wherein a particle diameter (D50) corresponding to 50% of accumulation in a volume-based particle size distribution obtained by measuring the first silver powder in the wet process is in the range of from 1 μm to 4 μm,
wherein a particle diameter (D50) corresponding to 50% of accumulation in a volume-based particle size distribution obtained by measuring the second silver powder in the wet process is in the range of from 0.3 μm to 1 μm, and
wherein a weight ratio (first silver powder:second silver powder) of the first silver powder to the second silver powder in the mixed silver powder is 95:5 to 50:50.

4 more elements

A silver powder of silver, the silver powder having three peaks or more, at each of which a frequency is a local maximum value in a volume-based particle size distribution obtained by measuring the silver powder in a dry process by means of a laser diffraction particle size distribution analyzer, the silver powder having one peak, at which a frequency is a local maximum value in a volume-based particle size distribution obtained by measuring the silver powder in a wet process by means of a laser diffraction scattering particle size distribution analyzer,

wherein a particle diameter (D50) corresponding to 50% of accumulation in a volume-based particle size distribution obtained by measuring the silver powder in the wet process is in the range of from 1.2 μm to 3.0 μm, and
wherein the silver powder of silver is a mixed silver power comprising:
a first silver powder of silver having one peak or more, at each of which a frequency is a local maximum value in a volume-based particle size distribution obtained by measuring the first silver powder in a dry process by means of a laser diffraction particle size distribution analyzer;
and
a second silver powder of silver having two peaks or more, at each of which a frequency is a local maximum value in a volume-based particle size distribution obtained by measuring the second silver powder in a dry process by means of the laser diffraction particle size distribution analyzer,
wherein a particle diameter (D50) corresponding to 50% of accumulation in a volume-based particle size distribution obtained by measuring the first silver powder in the wet process is in the range of from 1 μm to 4 μm,
wherein a particle diameter (D50) corresponding to 50% of accumulation in a volume-based particle size distribution obtained by measuring the second silver powder in the wet process is in the range of from 0.3 μm to 1 μm, and
wherein a weight ratio (first silver powder:second silver powder) of the first silver powder to the second silver powder in the mixed silver powder is 95:5 to 50:50.

5 more elements

Dependencies are inferred from the claim text.

Facts

Application: 17/621,896Filed 16 Jun 2020
Priority: JP 2019-11991127 Jun 2019
Published: US 2022/0243086 A14 Aug 2022
Granted: 2 Jun 2026
Term ends: Not estimatedThe source records don’t support an estimate.

Classification17 codes

H01B 1/22
Conductive material dispersed in non-conductive organic material: the conductive material comprising metals or alloys
B22F 1/00
Metallic powder
B22F 1/052
Metallic powder characterised by the size or surface area of the particles: characterised by a mixture of particles of different sizes or by the…
B22F 1/107
Metallic powder containing lubricating or binding agents; Metallic powder containing organic material: containing organic material comprising…