Manufacturing of microstructures with high aspect ratio by micromachining

The development of micromachining plays an important role in miniaturization of microsystems. Micromachining is a very flexible and compared to EDM or ECM a very fast machining process with a high material removal rate. A wide range of materials like polymers, metals and alloys as well as some sorts of ceramics can be machined. Also 3D-structures can be easily manufactured. Additionally, big advances have been made concerning the realization of high aspect ratios for small diameter end mills. Whereas end mills below 100 μm diameter are limited to an aspect ratio of 1.5, end mills of 100 μm diameter are available up to an aspect ration of ten now. A few years ago, end mills in this diameter range were uncoated. Nowadays, there was a big progress in the coating technology so that these end mills can be coated with layers as thin as 0.5 μm.