抄録
Plating conditions obtained by using Hull Cell cover a wide range of electric current density, so that this cell has been used generally for decision of plating conditions or selection of plating baths. In order to utilize the results of plating in Hull Cell, a few experimental equations of the distribution of current density on the cathode have been proposed. These equations are shown as straight lines on semilogarithmic graph paper concerning the points on cathode and the current densities. In this study, we selected a cupric sulphate solution as plating bath for Hull Cell test and measured the film thickness by two methods: microscope and electromagnetic meter; the current density was calculated from the film thickness. Theoretical current density was obtained by means of conformal mapping. The current density measured by the microscopic method agreed with the theoretical current density. In regard to the relation between logarithm of distance from the bottom of cathode and current density, we propose an approximate equation, combining two straight line formulas, instead of the traditional equation which is a straight line formula, because the former is much more accurate than the latter.
