Steven P Cahill

US Patent:

6744228, Jun 1, 2004

Filed:

Jul 11, 2000

Appl. No.:

09/613833

Inventors:

Steven P. Cahill - Newton MA
Bradley L. Hunter - Lexington MA

Assignee:

GSI Lumonics Corp. - Billerica MA

International Classification:

H01L 2168

US Classification:

318135, 318687, 355 53

Abstract:

A high-speed precision positioning apparatus has a stage supported by a platen. The stage is driven by a plurality of drive motors that are co-planar with the stage and arranged symmetrically around the stage. The drive motors apply drive forces directly to the stage without any mechanical contact to the stage. The drive forces impart planar motion to the stage in at least three degrees of freedom of motion. In the remaining three degrees of freedom the motion is constrained by a plurality of fluid bearings that operate between the stage and the platen. The drive motors are configured as magnets, attached to the stage, moving in a gap formed in-between top and bottom stationary coils. Integral force cancellation is implemented by a force cancellation system that applies cancellation forces to the stage. The cancellation forces, which are co-planar with a center of gravity of the stage and any components that move with the stage, cancel forces generated by planar motion of the stage. Interferometric encoders are used as position detectors.

US Patent:

6949844, Sep 27, 2005

Filed:

Dec 29, 2003

Appl. No.:

10/747552

Inventors:

Steven P. Cahill - Newton MA, US
Bradley L. Hunter - Lexington MA, US

Assignee:

GSI Group Corporation - Billerica MA

International Classification:

H02K021/00

US Classification:

310 12, 355 53, 355 72

Abstract:

A high-speed precision positioning apparatus has a stage supported by a platen. The stage is driven by a plurality of drive motors that are co-planar with the stage and arranged symmetrically around the stage. The drive motors apply drive forces directly to the stage without any mechanical contact to the stage. The drive forces impart planar motion to the stage in at least three degrees of freedom of motion. In the remaining three degrees of freedom the motion is constrained by a plurality of fluid bearings that operate between the stage and the platen. The drive motors are configured as magnets, attached to the stage, moving in a gap formed in-between top and bottom stationary coils. Integral force cancellation is implemented by a force cancellation system that applies cancellation forces to the stage. The cancellation forces, which are co-planar with a center of gravity of the stage and any components that move with the stage, cancel forces generated by planar motion of the stage. Interferometric encoders are used as position detectors.

US Patent:

7015418, Mar 21, 2006

Filed:

May 15, 2003

Appl. No.:

10/438533

Inventors:

Steven P. Cahill - Newton MA, US
Jonathan S. Ehrmann - Sudbury MA, US
You C. Li - Reading MA, US
Rainer Schramm - Everett MA, US
Kurt Pelsue - Wayland MA, US

Assignee:

GSI Group Corporation - Billerica MA

International Classification:

B23K 26/00

US Classification:

21912169, 21912168

Abstract:

A method of calibrating a laser marking system includes calibrating a laser marking system in three dimensions. The step of calibrating includes storing data corresponding to a plurality of heights. A position measurement of a workpiece is obtained to be marked. Stored calibration data is associated with the position measurement. A method and system for calibrating a laser processing or marking system is provided. The method includes: calibrating a laser marker over a marking field; obtaining a position measurement of a workpiece to be marked; associating stored calibration data with the position measurement; relatively positioning a marking beam and the workpiece based on at least the associated calibration data; and calibrating a laser marking system in at least three degrees of freedom. The step of calibrating includes storing data corresponding to a plurality of positions and controllably and relatively positioning a marking beam based on the stored data corresponding to the plurality of positions.

US Patent:

20040144760, Jul 29, 2004

Filed:

May 15, 2003

Appl. No.:

10/438500

Inventors:

Steven Cahill - Newton MA, US
Jonathan Ehrmann - Sudbury MA, US
John Gillespie - Salem MA, US
You Li - Reading MA, US
Chris Nemets - Camarillo CA, US
Rainer Schramm - Everett MA, US
Kevin Sullivan - Everett MA, US
Walter Leslie - Westborough MA, US
Michael Woelki - Stow MA, US
Kurt Pelsue - Wayland MA, US

International Classification:

B23K026/00
B23K026/06

US Classification:

219/121680, 219/121830

Abstract:

A system for semiconductor wafer marking is provided. The system includes: (a) a first positioning subsystem for positioning a laser marking field relative to a wafer, the positioning along a first direction; (b) an alignment vision subsystem; (c) a laser marker including a laser for marking a location within the marking field with a laser marking beam; (d) a calibration program for calibrating at least one subsystem of the system; and (e) a controller. The marking field is substantially smaller than the wafer, and the laser marker includes a scan lens for optically maintaining a spot formed by the beam on the wafer within an acceptable range about the location within the marking field so as to avoid undesirable mark variations associated with wafer sag or other variations in depth within the field.

US Patent:

20060054608, Mar 16, 2006

Filed:

Nov 4, 2005

Appl. No.:

11/266844

Inventors:

Steven Cahill - Newton MA, US
Jonathan Ehrmann - Sudbury MA, US
You Li - Reading MA, US
Rainer Schramm - Everett MA, US
Kurt Pelsue - Wayland MA, US

Assignee:

GSI Lumonics Corporation - Billerica MA

International Classification:

B23K 26/02

US Classification:

219121830, 219121690

Abstract:

A method of calibrating a laser marking system includes calibrating a laser marking system in three dimensions. The step of calibrating includes storing data corresponding to a plurality of heights. A position measurement of a workpiece is obtained to be marked. Stored calibration data is associated with the position measurement. A method and system for calibrating a laser processing or marking system is provided. The method includes: calibrating a laser marker over a marking field; obtaining a position measurement of a workpiece to be marked; associating stored calibration data with the position measurement; relatively positioning a marking beam and the workpiece based on at least the associated calibration data; and calibrating a laser marking system in at least three degrees of freedom. The step of calibrating includes storing data corresponding to a plurality of positions and controllably and relatively positioning a marking beam based on the stored data corresponding to the plurality of positions.

US Patent:

45717184, Feb 18, 1986

Filed:

Jul 11, 1984

Appl. No.:

6/629875

Inventors:

Steven P. Cahill - Newton MA
Roger G. Covington - Rochester NY

Assignee:

Eastman Kodak Company - Rochester NY

International Classification:

G11B 700
G65D 8530

US Classification:

369291

Abstract:

Structure is provided for separately sealing an optical disk cartridge and cooperating apparatus closed when the cartridge and apparatus are not operatively engaged for intended use, and for opening the cartridge and apparatus to each other while jointly closing them from the environment when they are so engaged. The optical disk includes a magnetically attractable hub bearing a compliant annular seal. The disk-containing cartridge is permanently closed except for a central drive-access opening in one wall thereof that is bounded by a circular rim concentrically aligned with the hub seal. Magnetic means on that wall atrract the hub and thereby draw its seal into firm contact with the rim, to seal the opening closed whenever the cartridge is not in use. The cooperating apparatus includes a drive spindle that is bounded by a circular flange also concentrically aligned with the hub seal. Associated mechanism engages the spindle axially with the hub so as to move the flange into contact with the hub seal while moving the seal out of contact with the rim.

US Patent:

6144118, Nov 7, 2000

Filed:

Sep 18, 1998

Appl. No.:

9/156895

Inventors:

Steven P. Cahill - Newton MA
Bradley L. Hunter - Lexington MA

Assignee:

General Scanning, Inc. - Wilimington MA

International Classification:

H01L 2100

US Classification:

310 12

Abstract:

A high-speed precision positioning apparatus has a stage supported by a platen. The stage is driven by a plurality of drive motors that are co-planar with the stage and arranged symmetrically around the stage. The drive motors apply drive forces directly to the stage without any mechanical contact to the stage. The drive forces impart planar motion to the stage in at least three degrees of freedom of motion. In the remaining three degrees of freedom the motion is constrained by a plurality of fluid bearings that operate between the stage and the platen. The drive motors are configured as magnets, attached to the stage, moving in a gap formed in-between top and bottom stationary coils. Integral force cancellation is implemented by a force cancellation system that applies cancellation forces to the stage. The cancellation forces, which are co-planar with a center of gravity of the stage and any components that move with the stage, cancel forces generated by planar motion of the stage.