High aspect ratio electroplated microstructures using a photosensitive polyimide process

Abstract

A polymide-based process for the fabrication of high-aspect ratio microstructures is presented. The process exploits the sharp-sidewall characteristics of photosensitive polyimide to create the electroplating form through which the high-aspect-ratio structures are electroplated. Although the resolution of this process is inferior to the synchrotron-based process, this process has several advantages: it is simple and can be carried out using commercially available materials and common clean room equipment; the excellent chemical and thermal resistance of polyimide allows plating to take place in a variety of environments; and multiple coats of polyimide can be used to fabricate vertically integrated structures which have variation in the third dimension. The process is completely compatible with surface micromachining sacrificial layer techniques to create released electroplated microstructures. >