Abstract: This paper describes a method to measure and
compensate a 4 axes ultra-precision machine tool that generates micro
patterns on the large surfaces. The grooving machine is usually used
for making a micro mold for many electrical parts such as a light guide
plate for LCD and fuel cells. The ultra precision machine tool has three
linear axes and one rotational table. Shaping is usually used to
generate micro patterns. In the case of 50 μm pitch and 25 μm height
pyramid pattern machining with a 90° wedge angle bite, one of linear
axis is used for long stroke motion for high cutting speed and other
linear axis are used for feeding. The triangular patterns can be
generated with many times of long stroke of one axis. Then 90°
rotation of work piece is needed to make pyramid patterns with
superposition of machined two triangular patterns.
To make a two dimensional positioning error, straightness of two
axes in out of plane, squareness between the each axis are important.
Positioning errors, straightness and squarness were measured by laser
interferometer system. Those were compensated and confirmed by
ISO230-6. One of difficult problem to measure the error motions is
squareness or parallelism of axis between the rotational table and
linear axis. It was investigated by simultaneous moving of rotary table
and XY axes. This compensation method is introduced in this paper.
Abstract: Rotating stages in semiconductor, display industry and many other fields require challenging accuracy to perform their functions properly. Especially, Axis of rotation error on rotary system is significant; such as the spindle error motion of the aligner, wire bonder and inspector machine which result in the poor state of manufactured goods. To evaluate and improve the performance of such precision rotary stage, unessential movements on the other 5 degrees of freedom of the rotary stage must be measured and analyzed. In this paper, we have measured the three translations and two tilt motions of a rotating stage with high precision capacitive sensors. To obtain the radial error motion from T.I.R (Total Indicated Reading) of radial direction, we have used Donaldson's reversal technique. And the axial components of the spindle tilt error motion can be obtained accurately from the axial direction outputs of sensors by Estler face motion reversal technique. Further more we have defined and measured the sensitivity of positioning error to the five error motions.