Copper powder for conductive paste, conductive paste using the copper powder, and chip component including a conductor using the conductive paste

摘要

PROBLEM TO BE SOLVED: To obtain copper powder which allows a low temperature baking property required for the baking manufacture of a conductive body of chip component using a conductive paste which is produced by using the copper powder and is made lower in viscosity when being fabricated into the conductive paste. SOLUTION: In this copper powder which is used for production of conductive paste and has a surface oxidized layer, weight accumulative particle size D50 according to laser diffraction scattering type particle size distribution measurement method is 0.05 m to 10 m, the value of (SD/D50 )100 which is a relation between D50 and standard deviation SD of particle size distribution measured by the laser diffraction scattering type particle size distribution measurement method is =28 and the oxygen content of the copper powder is 0.5 wt.% to 3.0 wt.%. This copper powder is produced in such a manner that copper powder is subjected to heating treatment in the air or in an environment enhanced in oxygen partial pressure, the oxidized layer is formed on the surface of powder particle constituting the copper powder, the copper powder formed with the oxidized layer is subjected to re-powdering treatment, thereby the surface of powder particle is flattened and the powder particle in the state of aggregated state is separated.