Low density high surface area copper powder and electrodeposition process for making same

摘要

This invention relates to a low density high surface area copper powder having an apparent density in the range of about 0.20 to about 0.60 gram per cubic centimeter, and a surface area of at least about 0.5 square meter per gram. This invention also relates to an electrodeposition process for making the foregoing copper powder by electrodepositing the copper powder from an electrolyte solution using a critical combination of process parameters. These critical parameters include: a copper ion concentration for the electrolyte solution in the range of about 2 to about 7 grams per liter; a free chloride ion concentration for the electrolyte solution in the range of about 8 to about 20 ppm; an impurity level for the electrolyte solution of no more than about 1.0 gram per liter; and an electrolyte solution that is free of organic additives.