Data processing: generic control systems or specific application – Specific application – apparatus or process – Article handling
Reexamination Certificate
2000-10-12
2004-04-06
Walsh, Donald P. (Department: 3653)
Data processing: generic control systems or specific application
Specific application, apparatus or process
Article handling
C700S189000, C700S190000, C700S218000, C700S229000
Reexamination Certificate
active
06718227
ABSTRACT:
TECHNICAL FIELD OF THE INVENTION
This invention relates generally to the field of wafer processing and, more particularly, to a system and method for determining a position error in a wafer handling device.
BACKGROUND OF THE INVENTION
Probers, steppers, wafer inspection systems, integrated circuit mounters, bonders, and other wafer handling devices typically must accurately position wafers of integrated circuits before operating on the wafers. For example, a prober must accurately position a wafer before electrically testing the integrated circuits mounted to the wafer. If the prober correctly positions the wafer, testing probes touch and electrically couple to contact points, allowing the prober to test the integrated circuits. If, however, the prober incorrectly positions the wafer, the testing probes may miss the contact points, and as a result, the prober may be unable to test the integrated circuits. Even worse, the testing probes may accidentally touch and damage integrated circuits on the wafer. To avoid these and other positioning problems, wafer handling devices typically uses high-precision lead screws, air bearing tables, or other mechanical devices to properly position wafers.
Unfortunately, wafer handling devices still suffer from position errors due to manufacturing faults, mechanical wear and stress, temperature variations, and other sources of positioning inaccuracies. Faults in the construction of lead screws, bearings, bushings, or other physical components introduce positioning inaccuracies in wafer handling devices, and mechanical stress and wear further deteriorate the positioning accuracy of these devices. Chucks, tools, and the electronic motor drive provide still another source of position errors. By causing materials to expand or contract, temperature variations also affect the position of a wafer in a wafer handling device. Due to these and other factors, wafer handling devices often improperly position wafers during operation.
SUMMARY OF THE INVENTION
In accordance with the present invention, a system and method for determining a position error in a wafer handling device is provided that substantially eliminates or reduces disadvantages or problems associated with previously developed systems and methods.
In one embodiment, a system for determining a position error in a wafer handling device includes a control module, an image acquisition module, and an image analysis module. The control module moves a workpiece having one or more reference marks, and the image acquisition module captures an image of at least one reference mark. The image analysis module, which is coupled to the image acquisition module, compares the captured image to stored target information to determine a position error.
The technical advantages of the present invention include a system and method for determining a position error in a wafer handling device. By using automatic visual inspection technology, the system and method accurately and efficiently identify a position error, determine a direction and magnitude of the position error along one or more axes, and generate control information to correct the position error. When in a calibration mode, the system and method profile the positioning accuracy of a wafer handling device over a specified plane of operation, generate control information to improve the positioning accuracy of the wafer handling device, and store the control information for future use by the wafer handling device. When in a real-time error correction mode, the system and method identify and correct position errors as a wafer handling device operates on a wafer. Other technical advantages are readily apparent from the attached description, figures, and claims.
REFERENCES:
patent: 4510565 (1985-04-01), Dummermuth
patent: 4685206 (1987-08-01), Kobayashi et al.
patent: 4786617 (1988-11-01), Umatate et al.
patent: 4819167 (1989-04-01), Cheng et al.
patent: 4833621 (1989-05-01), Umatete
patent: 4903437 (1990-02-01), Kubotera et al.
patent: 5204535 (1993-04-01), Mizutani
patent: 5365342 (1994-11-01), Ayata et al.
patent: 5381210 (1995-01-01), Hagiwara
patent: 5392371 (1995-02-01), Imaizumi et al.
patent: 5500869 (1996-03-01), Yoshida et al.
patent: 5511005 (1996-04-01), Abbe et al.
patent: 5524175 (1996-06-01), Sato et al.
patent: 5563798 (1996-10-01), Berken et al.
patent: 5640101 (1997-06-01), Kuji et al.
patent: 5645391 (1997-07-01), Ohsawa et al.
patent: 5737441 (1998-04-01), Nishi
patent: 5740034 (1998-04-01), Sacki
patent: 5747816 (1998-05-01), Kurosaki
patent: 5801390 (1998-09-01), Shiraishi
patent: 5811211 (1998-09-01), Tanaka et al.
patent: 5825483 (1998-10-01), Michael et al.
patent: 5978081 (1999-11-01), Michael et al.
patent: 5982474 (1999-11-01), Akiyama et al.
patent: 6108089 (2000-08-01), Shiraishi
patent: 6275742 (2001-08-01), Sagues et al.
patent: 6331885 (2001-12-01), Nishi
patent: 6354909 (2002-03-01), Boucher et al.
patent: 2001/0024278 (2001-09-01), Yoshida
Hoehner Troy W.
Reeves George W.
Schemmel Floyd F.
Brady III Wade James
Butler Michael E.
Skrehot Michael K.
Telecky , Jr. Frederick J.
Texas Instruments Incorporated
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