Microfabrication by hot embossing and injection molding at LASTI

LIGA process includes three processes as X-ray lithography, electroforming to fabricate metalic molds and replication, and can be fabricated nano and micro parts for various devices that it is difficult to product by conventional machining methods. A key technology which gathers mass-production efficiency in the LIGA process is micro-replication technology. We choiced hot embossing and injection molding methods for replication. For a demonstration, two kinds of Ni molds, a mesh pattern within a line width of 100 m, and an aspect ratio of 1.0 and a mesh pattern within a line width of 40 m, and an aspect ratio of 2.5, were prepared. These were produced with X-ray lithography and nickel electrofoming technique. In hot embossing, an experiment of micro-replication using polymethyl methacrylate (PMMA) and polycarbonate (PC) sheets succeeded. At injection molding, it could not transfer well with PMMA and PC, but injection temperature was set up highly, and it succeeded by cycloolefin polymer. Furthermore, we measured sidewalls surface roughness of microstructures produced at each steppes of the LIGA process, and it checked that the LIGA process had processing accuracy higher than a conventional machining method.We would like to thank Ms. A. Kitajima and Dr. R. Maeda at National Institute of Advanced Industrial Science and Technology (AIST), Mr. M. Ohtomo at Ikegami Mold Engineering Co., Ltd., and Mr. Noriaki Sato at Juken Kogyo Co., Ltd. for their valuable collaboration and contributions. This research was the contract research from the New Industry Research Organization (NIRO) supported financially by the New Energy and Industrial Technology Development Organization (NEDO).