Micromilling development and applications for microfabrication

Abstract In conventional machining, milling is the most versatile of the cutting processes. Micromechanical milling has also been shown to be a very versatile and repid method for the removal of material and the creation of microstructures. These microstructures range form direct fabrication of molds in polymethyl methacrylate (PMMA) to direct fabrication of x-ray lithography masks using a machinable carrier and one of several metallic absorbers, or various combinations of absorbers to better suit the machining environment. The micromilling tools are commercially available in diameters larger than 50 micrometers and custom-fabricated tools 22 micrometers in diameter are made at the Institute for Micromanufacturing (IfM). The custom-fabricated tools are made using the focused ion beam process and the resulting microstructures are machined on a very high precision, custom-built milling machine. The focused ion beam process has also been used to fabricate very small probe tips for biomedical use and microscalpels with extremely sharp cutting edges. These devices are currently under study and development for research applications.