Numerical study of the influence of the anode position and the electrolyte flow on the deposition of copper on a wire

The influence of the fluid flow and the cell geometry on the deposition of copper on wires was studied numerically. A numerical method based on the system residual distribution schemes and the finite element method was developed to calculate the fluid flow and the mass transfer including the effects of diffusion, migration, convection, homogeneous reactions, turbulence and multiple electrode reactions in arbitrary shaped geometries. The k-omega model was used to calculate the turbulent fluid flow, and the turbulent Schmidt number is assumed equal to one. It was demonstrated that a downstream position of the anode yields a much more uniform deposition compared with an upstream placement of the anode. From calculations with different imposed currents, it was established that mass transfer only plays an important role if the current is above 70% of the limiting current. Furthermore, simulations with different flow rates, indicated that turbulent flow reduces the effects of mass transfer on the current density distribution. (c) 2007 Elsevier Ltd. All rights reserved.