Recent applications of polyimide to micromachining technology

In this paper, applications of polyimide materials to micromachining technology are reviewed. First, the use of polyimide-based materials as sensor materials are discussed. In this case, the polyimide material is used as an integral part of the micromachined devices. Emphasis is given to the development and characterization of a piezoresistive composite of polyimide and graphite particles. The composite material is characterized for the mechanical properties (Young´s modulus, residual stress) and the electromechanical property (piezoresistive coefficient). Second, the use of both photosensitive and nonphotosensitive polyimides as electroplating molds for the fabrication of thick and high aspect ratio metallic microstructures is presented. Extensions of the basic micromolding process, which enable the fabrication of controlled gaps between metallic microstructural components and higher aspect ratio microstructures, are presented. Electroplated metallic microstructures realized using these technologies are shown. In addition, various applications of the polyimide micromolding technologies are discussed