COPPER POWDER, MANUFACTURING METHOD THEREFOR, COPPER PASTE USING THE COPPER POWDER, AND PRINTED CIRCUIT BOARD USING THE COPPER PASTE

摘要

PROBLEM TO BE SOLVED: To provide a method for manufacturing a copper powder which reduces viscosity variations of copper paste and lowers the viscosity, and provide a copper powder. SOLUTION: The less coagulative copper powder is characterized by that a coagulation degree expressed by D50 /DIA is 1.5 or less, which is calculated from an average particle diameter D50 measured by a laser-diffraction scattering type grain-size distribution method, and an average particle diameter DIA, which is obtained from an image analysis. The copper paste is manufactured by using the powder. The method for manufacturing the less coagulative copper powder used for obtaining the less coagulative copper paste, is characterized by decomposing grains of the dry coagulated copper powder with a centrifugal wind power circulator.