In this research, the achievable precision level using mechanical datums for manufacturing has been studied. Specifically, the effect of how a datum is secured in a mechanical alignment system was studied with the aid of a high-resolution multidimensional optical position monitoring system developed for the purpose. The study shows that the way datum is secured can be a major factor affecting the alignment precision of a mechanical alignment system. For a datum prepared by randomly inserting dowel pins into precision bored holes, a common practice in industry, the precision level was found to be worse than 10 μm. The results also show that the precision level can be readily improved by addressing this major cause of inaccuracy. Different methods depending on manufacturing requirements and constraints have been proposed. Some of these simple procedures lead to more than an order of magnitude improvement in alignment precision. [S1087-1357(00)02001-3]

Issue Section:
Technical Papers
Keywords:
manufacturing processes, position control, machine tools
Topics:
Bonding, Design, Manufacturing, Monitoring systems, Pins (Engineering), Screws, Surface roughness, Rotation, Resolution (Optics)
1.
Van Zant, P., 1990, Microchip Fabrication—A Practical Guide to Semiconductor Processing, 2nd ed., McGraw-Hill, New York, Chap. 8.
2.
Mickan
,
U.
, and
Rinn
,
K.
,
1993
, “
Absolute Pattern Placement Metrology On Wafers
,”
SPIE
,
1926
, pp.
412
–
419
.
3.
Zaid
,
S. H.
,
Frauenglass
,
A.
, and
Brueck
,
S. R. J.
,
1994
, “
Moire´ Interferometric Alignment and Overlay Techniques
,”
SPIE
,
2196
, pp.
371
–
382
.
4.
O’Mara, W. C., 1993, Liquid Crystal Flat Panel Display, Van Nostrand Reinhold, New York, Chap. 2.
5.
Jorgensen, F., 1988, The Complete Handbook of Magnetic Recording, Tab Books, Blue Ridge Summit, PA.
6.
Lee, N. K. S., Jain, A., and Keppeler, E., “Apparatus and Method for Fabrication of a Lens/Mirror Tower,” U.S. Patent 5,260,928.
7.
Siegman, A. E., 1986, Lasers, University Science Books, Mill Valley, CA.
8.
Lee
,
N.
, and
Joneja
,
A.
,
1997
, “
A Method to Improve Manufacturing Precision in the Presence of Workpiece Imperfections
,”
ASME J. Manuf. Sci. Eng.
,
119
, pp.
616
–
622
.
9.
Lee
,
N.
,
Cai
,
Y.
, and
Joneja
,
A.
,
1997
, “
A High Resolution Multi-dimensional Displacement Monitoring System
,”
J. Opt. Eng.
,
36
, pp.
2287
2287
.
10.
Lou
,
D. Y.
,
Martinez
,
A.
, and
Stanton
,
D.
,
1984
, “
Surface Profile Measurement with a Dual-Beam Optical System
,”
Appl. Opt.
,
23
, No.
5
, pp.
746
–
751
.
11.
Kazovsky
,
L. G.
,
1983
, “
Theory of Tracking Accuracy of Laser Systems
,”
Opt. Eng.
,
22
, No.
3
, pp.
339
–
347
.
12.
Ackerson
,
D. S.
, and
Harry
,
D. R.
,
1985
, “
Theory, Experimental Results, and Recommended Standards Regarding the Static Positioning and Orientation Precision of Industrial Robots
,”
Rob. Comput.-Interger. Manuf.
,
2
, No.
3–4
, pp.
247
–
259
.
13.
Lau
,
W. S.
, and
Ng
,
K. L.
,
1992
, “
Experimental and Statistical Determination of the Static Position Repeatability and a Recommended Specification for a SCARA Robot
,”
Robotics Comput.-Integ. Manuf.
,
9
, No.
3
, pp.
247
–
253
.
14.
Slocum, A. H., Precision Machine Design, Prentice Hall, Englewood Cliffs, NJ, Sec. 7.7, pp. 401–412.
15.
Our particular implementation may not be optimized. We are indebted to one of our reviewers, who has provided us with references on kinematic clamp and has pointed out this fact about our implementation.
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