1. National Taiwan University Mechanical Engineering Precision Metrology Lab.
Development of a high precision co-planar
stage with a multi-degree-of-freedom sensor
Professor Kuang-Chao FanNTU
Dept. of Mechanical Engineering
National Taiwan University
Nov 8th
, 2012 at IFToMM
Hung-Yu Wang, Chung-Hao Lin, Bo-Hsun Liao

2. National Taiwan University Mechanical Engineering Precision Metrology Lab.
Outline
The need of Micro/Nano Measurements
Components and principles of the Co-planar stage
Multi-Degree-of-freedom Sensor
Experimental tests
Conclusions

3. National Taiwan University Mechanical Engineering Precision Metrology Lab.
Gap between Micro to Meso Regions
Microgrooves

4. National Taiwan University Mechanical Engineering Precision Metrology Lab.
Specifications of Traditional and Micro CMMs
Source ： Takamasu Lab. http://www.nano.pe.u-tokyo.ac.jp/

5. National Taiwan University Mechanical Engineering Precision Metrology Lab.
Evolution of the Co-planar stage
 Co-planar stage design maintenance. (Abbé error free)
 MDFS measures not only distance but also two angle. (Pitch & Yaw)
 Stage motion measurement directly. (Excluded backlash, angle… compensation)

6. National Taiwan University Mechanical Engineering Precision Metrology Lab.
Abbé principle in Co-planar Stage
Abbé principle for 3D motions

7. National Taiwan University Mechanical Engineering Precision Metrology Lab.
The configuration of the Multi-Degrees-of-
freedom Sensor
Moving Mirror
Displacement
Pitch & Yaw
Quadrant
Detector
Laser Diode
Reference
Mirror
BS1
BS2
BS3
Q1
Q2 Q3
Quadrant Detector
Focusing Lens
PBS1 PBS2
PBS3
PD1
PD2
PD3
PD4
Focusing
Lens
Michelson interferometer
Autocollimator
Wavelength compensator
PBS : Polarized Beam Splitter
BS : Beam Splitter
Q : Quarter-Wave Plate
PD : Photodetector
Moving Mirror
Displacement
Pitch & Yaw
Quadrant
Detector
Laser Diode
Reference
Mirror
BS1
BS2
BS3
Q1
Q2 Q3
Quadrant Detector
Focusing Lens
PBS1 PBS2
PBS3
PD1
PD2
PD3
PD4
Focusing
Lens
Michelson interferometer
Autocollimator
Wavelength compensator
PBS : Polarized Beam Splitter
BS : Beam Splitter
Q : Quarter-Wave Plate
PD : Photodetector

8. National Taiwan University Mechanical Engineering Precision Metrology Lab.
Multi-Degrees-of-freedom Sensor
Michelson interferometer
1
2
1 cos( )PD
d
I A
π
λ
 
= − 
 
2
2
1 cos( )PD
d
I A
π
λ
 
= + 
 
3
2
1 sin( )PD
d
I A
π
λ
 
= + 
 
4
2
1 sin( )PD
d
I A
π
λ
 
= − 
 
Signal process

9. National Taiwan University Mechanical Engineering Precision Metrology Lab.
Multi-Degrees-of-freedom Sensor
Autocollimator
Signal process
Collimating lens
Polarizing beam
splitter
Photodiode IC
Laser diode
AB
DC
Focusing lens
θ
0 (Incline angle)
Mirror
Y-axis
X-axis
Collimating lens
Polarizing beam
splitter
Photodiode IC
Laser diode
AB
DC
AB
DC
Focusing lens
θ
0 (Incline angle)
Mirror
Y-axis
X-axis 2[( ) ( )]x A B C DK V V V Vθ = + − +
2[( ) ( )]y B C A DK V V V Vθ = + − +
VA VA
VBVB VCVC
VD VD

10. National Taiwan University Mechanical Engineering Precision Metrology Lab.
Experiment result -- Positioning Error
Accuracy and repeatability of positioning
The relationship between SIOS
and Michelson values

11. National Taiwan University Mechanical Engineering Precision Metrology Lab.
Experiment result -- Abbé Error Compensation
Residual error with and without Abbé error compensation (Ly
= 6 mm 、 Lz = 0 mm)
Residual error with and without Abbé error compensation
(Ly = 6 mm 、 Lz = 2 mm)
Residual error with and without Abbé error compensation
(Ly = 6 mm 、 Lz = 3 mm)
zxyy LLE ⋅+⋅−= θθδ
Abbé error illustration

12. National Taiwan University Mechanical Engineering Precision Metrology Lab.
Conclusion
Residual error with and without Abbé error compensation (Ly
= 6 mm 、 Lz = 0 mm)
 New type of co-planar stage was developed to overcome nonlinear
error.
 The positioning error can be controlled to ±30 nm with standard
deviation 20 nm in 20mm travel range.
 The NDFS for co-planar stage with high accuracy was developed.
(can achieve 1 nm resolution )
 The Abbé error has been compensated due to the MDFS can measure
the yaw and pitch errors of the co-planar stage.
 LOW COST.

13. National Taiwan University Mechanical Engineering Precision Metrology Lab.
Thank you for your attention

14. National Taiwan University Mechanical Engineering Precision Metrology Lab.
Driver: Ultrasonic Motor (HR-4)
X1
X2
X1
X2u1
( x1
, x2
, t ) u2
( x1
, x2
, t )
A
B' A'
B
bending mode longitudinal mode
Elliptical motion of the piezoelectric
elements: vector sum of the bending
mode and the longitudinal mode AC mode: successive motion with
long stroke of 0.1mm-20mm.
GATE mode: short travel of 20-
30nm in steps.
DC mode: nanopositioning
motion of within 30nm.
Slide Moving direction
Finger tip
PZT element