Operation and Maintenance Manual Model 7AA Wafer Grinder
7 - 14 Version 1.2 - April 18, 1996
GRIND SPINDLE ALIGNMENT
The alignment between the work and grind spindles is critical to
machine performance. Mechanical adjustments are provided
for precise alignment in two planes of the upper grind spindle
position.
To perform the grind spindle alignment procedures requires a
basic understanding of the mechanics of the grind spindle
assembly. A drawing in the drawing section is provided to
illustrate the grind spindle assembly and adjustment points.
The axis for in and out motion of the work chuck is defined as
the "X" axis ("Axis 1"). The axis for up and down motion of the
grind spindle is defined as the "Z" axis ("Axis 2"). Using this
convention the axis perpendicular to both the X and Z axes is
from side to side and is denoted as the "Y axis".
The X-Z plane and Y-Z plane each have a different effect on
the ground wafer. The Y-Z plane (side to side) will cause one
side of the grinding wheel to be lower than the other. The result
of this condition is that the grinding will take place only on one
side of the wheel. This condition can be identified by a spiral
grind pattern on the wafer surface as opposed to a pinwheel
pattern. Since both the wafer and the wheels are rotating while
grinding this is not a serious problem. A large misalignment
would be required to produce significant parallelism problems.
For measuring grind spindle alignment remove one of the six
large wheel mounting screws. Using a longer screw mount a
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