Copper flake powder, method for producing copper flake powder, and conductive paste using copper flake powder

Abstract

The present invention is mainly for providing a flake copper powder for a conductive paste with particle properties which are defined by that the particle thickness is thinner being possible for use to form an electrode or a circuit, and a production process thereof. To achieve the object of producing the following particles, each powder particles shape is plastically processed into a flake-shape, wherein the flake copper powder has a cumulative particle diameter D50 of 10 μm or smaller measured with laser diffraction scattering particle size distribution method. The D10, D50 and D90 measured with the laser diffraction scattering particle size distribution method are illustrative and the SD/D50 value measured by the standard deviation of particle distribution with the laser diffraction scattering particle size distribution, is 0.55 or larger and/or a D90/D10 of 4.5 or smaller. The flake copper powder is compressed with a high energy ball mill whose media beads having fine particle diameter which plastically deforms the copper particles into flake-shaped particles, so that stable flake copper powder is produced.

Dependencies are inferred from the claim text.