This paper presents a measurement and compensation method of surface inclination for ductile cutting of silicon microstructures by using a diamond tool with a force sensor based on a four-axis ultra-precision lathe. The X - and Y -directional inclinations of a single crystal silicon workpiece with respect to the X - and Y -motion axes of the lathe slides were measured respectively by employing the diamond tool as a touch-trigger probe, in which the tool-workpiece contact is sensitively detected by monitoring the force sensor output. Based on the measurement results, fabrication of silicon microstructures can be thus carried out directly along the tilted silicon workpiece by compensating the cutting motion axis to be parallel to the silicon surface without time-consuming pre-adjustment of the surface inclination or turning of a flat surface. A diamond tool with a negative rake angle was used in the experiment for superior ductile cutting performance. The measurement precision by using the diamond tool as a touch-trigger probe was investigated. Experiments of surface inclination measurement and ultra-precision ductile cutting of a micro-pillar array and a micro-pyramid array with inclination compensation were carried out respectively to demonstrate the feasibility of the proposed method.

A three-axis fast tool servo (FTS) with a symmetric structure design to reduce the parasitic motion for realizing high tracking accuracy while maintaining high performances in stiffness and open-loop bandwidth is developed for ultraprecision diamond cutting. Modeling, analysis, and optimization of performances by the finite-element method in six degree-of-freedom are conducted for designing the mechanism. Experiments are carried out to test the performances of the three-axis FTS, which show low parasitic motion, high tracking accuracy, and high dynamic response. With the low tracking error of close-loop control for each axis, complicated trajectory tracking in 3-D space is realized with a tracking error as small as 5 nm. Finally, complicated and irregular microstructures are fabricated by the three-axis FTS to demonstrate the practicability of the FTS.

This paper presents a micro-coordinate measuring machine (micro-CMM) for large-scale dimensional measurement of a micro-slit on a precision die coater by using a shear-mode micro-probe. A glass micro sphere with a nominal diameter of 52.3 μm was attached on one end of a tapered glass capillary tube as a probe tip ball. The micro-slit width of a slot die coater with a nominal slit width of 85 μm was measured by the micro-CMM. The probe tip was placed in the slit for the measurement. The effective working length of the probe was confirmed experimentally to be at least 1 mm. In order to measure the gap width uniformity over the entire slot die length of 200 mm, an air-bearing linear slide with a travelling stroke of 300 mm was employed in the micro-CMM to position the probe along the length direction of the slot die. The angular alignment error and the motion error of the air-bearing linear slide as well as those of the stages for positioning the probe along the direction perpendicular to the length direction of the slot die were investigated for evaluation of the expanded uncertainty of gap width measurement.