Experimental investigation of the current distribution in Mohler cell and Rotating Cylinder Hull cell

Abstract

Two electroplating test cells have been proposed and tested to analyze the performance of plating solutions by studying the reaction distribution on the cathode during deposition of copper electrolyte. The first one is a modified Mohler cell composed of a rectangular electrolytic cell with forced electrolyte flow and two flat electrodes (an insulating separator is inserted between the cathode and anode). This screen modifies the electric field distribution, and leads to a non-uniform current distribution or deposit thickness on the cathode panel. The other is a rotating cylinder Hull cell consisting of an inner rotating cylinder electrode coaxial with a stationary outer insulating tube to produce a non-uniform current distribution along the length of a cylinder cathode. These kinds of cells are developed to overcome the absence of a controlled mass transport condition associated with the tradition Hull cell. From the experimental results, it appears that the rotating cylinder Hull cell is a better device to characterize and control electrolytic bath, while the experimental errors of the continuous Mohler cell were accounted for using simulation.