US 12,390,854 B2
Silver powder, method of producing silver powder, and conductive paste
Taro Torigoe, Okayama (JP); Hiroaki Koubu, Honjo (JP); Fumiya Abe, Takasaki (JP); and Minami Kanasugi, Kosaka-machi (JP)
Assigned to DOWA Electronics Materials Co., Ltd., Tokyo (JP)
Appl. No. 18/715,737
Filed by DOWA Electronics Materials Co., Ltd., Tokyo (JP)
PCT Filed Dec. 2, 2022, PCT No. PCT/JP2022/044630
§ 371(c)(1), (2) Date Jun. 3, 2024,
PCT Pub. No. WO2023/106245, PCT Pub. Date Jun. 15, 2023.
Claims priority of application No. 2021-198085 (JP), filed on Dec. 6, 2021; and application No. 2022-193053 (JP), filed on Dec. 1, 2022.
Prior Publication US 2025/0041936 A1, Feb. 6, 2025
Int. Cl. H01B 1/22 (2006.01); B22F 1/052 (2022.01); B22F 1/065 (2022.01); B22F 1/068 (2022.01); B22F 1/10 (2022.01); B22F 1/145 (2022.01); B22F 9/04 (2006.01); B22F 9/24 (2006.01)
CPC B22F 1/052 (2022.01) [B22F 1/065 (2022.01); B22F 1/068 (2022.01); B22F 1/10 (2022.01); B22F 1/145 (2022.01); B22F 9/04 (2013.01); B22F 9/24 (2013.01); H01B 1/22 (2013.01); B22F 2009/042 (2013.01); B22F 2009/043 (2013.01); B22F 2301/255 (2013.01); B22F 2304/10 (2013.01); B22F 2998/10 (2013.01); B22F 2999/00 (2013.01)] 6 Claims
OG exemplary drawing
 
1. A silver powder that in a volume-based particle size distribution measured using a laser diffraction/scattering particle size distribution measurement instrument, has a diameter at a cumulative value of 50% of 3 μm or more and a ratio of particles of 10 μm or larger of 10% or less, wherein
with regards to particle shape observed by image analysis based on an SEM image,
the silver powder includes flake-like particles having a major axis of 6 μm or more and irregularly shaped particles having a major axis of less than 6 μm,
an average aspect ratio that is a ratio of an average major axis of the flake-like particles relative to an average thickness of the flake-like particles is 8 or more, and
a shape factor that is a ratio of an area of a circle having an average maximum length of the irregularly shaped particles as a diameter relative to an average particle area of the irregularly shaped particles is not less than 1.7 and not more than 1.9, and
the silver powder has an ignition loss of not less than 0.1 wt % and not more than 0.4 wt %.