Strasbaugh 6DS-SP, Operation Manual

Page: 83 / 1562

Operations Model 6DS-SP Planarizer
2 - 24 Version 4.0 - February 1998
MECHANICAL DESCRIPTION
The section below provides descriptions of the mechanical assemblies and
components participating in the auto polish cycle functions.
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.