Uses of electroplated aluminum for the development of microstructures and micromachining processes

In this paper, electroplated aluminum is explored as both a material for the fabrication of microstructures and use in the development of micromachining processes. A method for the fabrication of aluminum microstructures based on electrodeposition from organic solutions is presented. An extension of this process involving the use of plated aluminum structures as plating molds for subsequent electrodeposition of other materials is also discussed. Maximum structure aspect ratios of 21:1 have been demonstrated using this extended micromolding process. Finally, an aluminum-based process, in which the width of a metallic microstructure or the gap between metallic microstructures is achieved by controlling the plating time, is discussed. Using this process, vertical-gap aspect ratios between metallic microstructures of 25:1 have been demonstrated. Since the width of these features is controlled by the plating time and not by photolithography, gaps between metallic microstructures or widths of electroplated features ranging from submicron to tens of microns can be easily achieved using this process.