Mixed copper powder, a manufacturing method of the mixed copper powder, a printed wiring board using the copper paste and copper paste using the mixture of copper powder

摘要

PROBLEM TO BE SOLVED: To provide mixed copper powder that can maintain excellent filling property of via holes when processed into paste and low electric resistance of a formed conductor.;SOLUTION: This mixed copper powder for manufacturing copper paste is formed by mixing first copper powder and second copper powder. The first copper powder is formed of flake copper powder of fine grain in which a grain diameter is 10 m or less, the value of SD/D₅₀ expressed using the weight accumulation grain diameter D₁₀, D₅₀ and D₉₀ measured by a laser diffraction scattering grain size distribution measuring method and the standard deviation SD of grain size distribution measured by the laser diffraction scattering grain size distribution measuring method is 0.5 or less, and a value expressed by D₉₀/D₁₀ is 4.0 or less. The second copper powder is formed of spherical copper powder having a grain diameter of 10 m or less and formed in approximately spherical shape.;COPYRIGHT: (C)2003,JPO