Strasbaugh Mechanical Maintenance Procedures
Version 1.2 - April 18, 1996 7 - 19
Perform a single coarse grind according to the instructions above
for two wafers. Measure the error for each wafer and compare it to
the programmed thickness. Determine the grind error using the
formula
grind error = programmed thickness - actual thickness
If the grind error is positive increase the Spindle Pretravel value by
the error; if negative decrease the value. Using multiple wafers for
the test will produce an average for more stable results. Multiple
wafer measurements should not vary by more than 5 microns. If
larger differences result then feed rates may be excessive for the
grind wheels and/or wafer product.
After modifying spindle pretravel data the machine must be
reinitialized. Spindle Pretravel compensation is only implemented
during machine initialization.
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