Development of a Meso-scale Machine Tool and the Preliminary Cutting Tests of Oxygen-free Copper Using a Polycrystalline Diamond Tool

Abstract

This work presents the development of a meso-scale 3-axis milling machine with a nanometer resolution. Regarding the Z-axis design of the meso-scale 3-axis milling machine, it mainly includes a pagoda structure, the high speed air bearing spindle, two HR8 ultrasonic motors, a laser diffraction grating interferometer system (LDGI), and a coaxial counter-balance system for the spindle. The optimal geometrical dimensions of the pagoda structure have been determined by ANSYS software. According to the simulation results, the maximum static deformation along the z-axis of the pagoda was about 5.05 nm. The designed meso-scale 3-axis milling machine is equipped with an X-Y coplanar positioning stage with nanometer resolution, including the low-cost components and two ultrasonic motors, in order to reduce the complexity and error resulted from the combination of a long-stroke stage and short-travel stage. The coplanar stage developed by Nation Taiwan University was integrated with two laser diffraction grating interferometer system as displacement feedback sensors, so that a two-axis closed-loop control was possible. The positioning accuracy of the coplanar stage was about 50nm after error compensation using the gate mode, base on the test results. A circular positioning test with the radius of 7 mm using the developed stage was tested, and the overall roundness error was about 0.094 mm based on the preliminary test results. A preliminary cutting tests for the oxygen-free copper using a polycrystalline diamond tool have been investigated with respect to different depth of cut and cutting speed on the developed meso-scale machine tool.

Research on a Long Travel Nanopositioning Air Bearing Stage with the Linear Motors

“…A novel open-loop long-travel piezoelectric-driven linear nano-positioning stage using the toggle amplification mechanism has been presented to eliminate the lateral offset error of the level mechanism in [3]. The coplanar stage with the travel of 25 mm X 25 mm, developed by Nation Taiwan University integrated with two laser diffraction grating interferometer system as displacement feedback sensors, has been applied to a meso-scale 3-axis machine tool to execute the microstructure fabrication [4]. Linear-motor-driven stages have been applied to super-precision machine tool [5].…”