Master of Science in Chemical Engineering (MSChE)
Pulse electrodeposition has been investigated as a general technique for the electrodeposition of nickel-tungsten alloys in deep recesses for MEMS. Ni-W exhibits an induced codeposition mechanism, where the Ni reaction rate enhances the codeposition of W. Electrodeposition of this alloy has been achieved into recesses of 500 micron deep. The challenges that have been encountered are those related to gas evolving side reactions, local pH rises, diffusional limitations of the soluble species and long times required for filling the recesses. Electrodeposition on cylinder electrodes at different rotation rates was also carried out in order to obtain data on composition of the alloy and current efficiency of the process, for different baths considered. These studies were carried out to examine the suitability of the bath for microstructure development and to describe better how the codeposition processes is affected by mass transport.
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Namburi, Lakshmikanth, "Electrodeposition of NiW alloys into deep recesses" (2001). LSU Master's Theses. 3534.
Elizabeth J. Podlaha