Strasbaugh 6DS-SP, Operation Manual

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STRASBAUGH, INC.
March 5, 1996 6DS-SP Ver 4.16.3 Page 12
This change supersedes the previous wafer handling where the second of two polished
wafers remained held on the robot for an extended time while the scrubber processes the
first wafer. The second wafer is now held in the scrubber flipper and rinsed. Also, two
different handling sequences are possible based on the setting of a new "busy" timeout.
Calibration Variable 156 “Scrubber type (0-DNS,1-OnTrak)” must be set to “1” if an
OnTrak scrubber is attached.
Calibration Variable 157 “OnTrak busy timeout (secs)” is applicable only to the OnTrak
scrubber and is used only when polishing with both spindles as follows:
When the first of the two polished wafers is still in the scrubber's first cleaning
station, the scrubber cannot accept the second wafer. The second wafer will be placed
in the scrubber flipper, rinsing starts, and the "OnTrak busy timeout" starts.
If the scrubber becomes "ready" (first wafer clears the scrubber's first cleaning station)
before the "busy" timeout, the second wafer is transferred to the scrubber. Then the
auto cycle continues to handle the next unpolished wafers.
If the "busy" timeout occurs before the scrubber becomes "ready", the auto cycle starts
handling the next unpolished wafers with the second polished wafer stored in the
flipper. When the scrubber subsequently becomes ready (first wafer clears the first
cleaning station) the second wafer is transferred to the scrubber.
These two timeout sequences can be used for two purposes:
1) Ensuring both wafers are transferred before the auto cycle continues: A "busy"
timeout that is comfortably longer than the "ready" waiting time will make sure
both polished wafers are transferred before the next wafers are handled.
2) Maximizing throughput: A "busy" timeout that is shorter than the "ready" waiting
time will force the 6DS-SP to continue autocycling at the end of the "busy" time.
Therefore, this time should be set to "0" for the fastest throughput.
New Post Polish Wafer Cleaning Choices for Two Table Machines: