Effect of Anode Shape on Uniformity of Electrodeposition onto Resistive Substrates

- Mathematic modeling for control of metal electrodeposition onto resistive annulus substrate.
- Method of calculating the anode shape to gain uniform deposit thickness over substrate surface.
- Calculation of dimensions and arrangement of insulating shields in order to eliminate edge effects.

This work is devoted to the theoretical study of the effect of anode shape, insulating shields, the exchange current density and operating conditions on the uniformity of metal layer deposited onto the resistive cathode. Laplace's equation for the potential in the electrolyte solution, Poisson's equation for the potential in the resistive cathode, and the equation of metal thickness evolution were used as the mathematical model. The numerical solution was performed using the boundary element and finite element methods. The possibilities for controlling the distribution of deposit thickness over the cathode surface are demonstrated by the example of metal deposition onto an annulus workpiece. The use of the anode of the calculated shape enabled us to obtain a deposit of uniform thickness over almost the entire workpiece surface except for the very edges, where the deposit was thicker. The application of shields designed in the work enabled us to eliminate this drawback.

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