Strasbaugh 6DS-SP, Operation Manual

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Maintenance Model 6DS-SP Planarizer
4 - 8 Version 4.0 - February 1998
BRIDGE DRIVE ASSEMBLY
The bridge assembly encloses and supports the left and right spindle assemblies
and their associated hardware. The bridge assembly moves the wafer carriers
between the load stations and the polish table; during the polishing cycle it
oscillates the wafer carriers and wafers over the surface of the polish table. The
bridge also oscillates over the second polish table when the second table option
is installed.
The bridge assembly is supported by two rails mounted on a solid framework.
Four linear bearing blocks, attached to the underside of the bridge assembly, ride
along the top of the rails. The drive assembly is a recirculating ball and lead
screw supported by the machine's framework at each end. Two pulleys and a
toothed drive belt connect the lead screw to a brushless DC servo motor. This
arrangement converts motor drive force into linear motion, moving the bridge
assembly left or right between the load stations and the polish table. The motor,
mounted to the machine's framework in the right side rear of the machine, is
accessible through the lower right side service door. Limit switches at each end
of the rails ensure the bridge assembly does not “run away”, crashing into the
side walls of the machine. Encoder feedback constantly reports back to the
control computer the exact position and velocity of the bridge assembly.
If the curtain rinse option is installed, after polishing the bridge pauses between
the polish table and the load stations to permit an extra rinsing of the carriers.
Curtain rinse type is chosen at page 2 of the Machine Parameters Menu. Curtain
rinse is enabled/disabled at page 3 of the Machine Parameters Menu. Curtain
rinse time is selected at page 3 of the Machine Parameters Menu. Table rinse
with curtain rinse is also enabled/disabled at page 3 of the Machine Parameters
Menu.