Abstract
The effect of surface area of graphite particles on the etching rate of copper was mainly investigated and based upon the experimental results the etching mechanism of copper is briefly discussed. The potential of the graphite suspension corresponds to the redox potential of a system consisting of graphite and its oxidized species formed at the anode. The suspension-potential is mainly controlled by the quantity of electricity accumulated per unit surface area of graphite particles by anodizing. The etching velocity of copper in the suspension increases with the increase in the total surface area of graphite particles striking the copper plate per unit time. The etching rate divided by the apparent surface area of graphite in the unit volume of the suspension increases with increasing concentration of graphite, but decreases with decreasing diameter of graphite particles. The etching of copper takes Place according to the local cell reaction consisting of Cu→Cu2++2e as anodic reaction and (C-OH)+H++e→C+H2O and partly O2+4H++4e→2H2O as cathodic reactions.
