Chapter 3. Using Your ATS
3.6
All measurements are in millimeters. Readings outside the working range of the teaching wafer
are displayed as ####. If the readings display
None
, ATS was not successful in finding the
target. This can be caused by the following:
•
Target too far off center.
The farther the target is initially from the center of the
field of view of the teaching wafer, the harder it is for ATS to find the target. Move
the teaching wafer so that the target appears closer to the sight ring and try finding
the target again. If you are having trouble seeing the target in the video image, you can
adjust the image by choosing the menu item
Settings > Optimize Lighting
.
•
Target criteria.
You might not have the target criteria set correctly. For more
information, see
“Setting the Target Criteria,” on page 3.10
. In particular, verify that
the Z distance you have specified in the target criteria is within 1 mm of the Z
distance used to create the target configuration file. The acceptable range for the Z
distance is displayed in the Set Target Criteria dialog (see
).
•
Wafer to target distance.
You might have the teaching wafer too close or too far
from the target. The distance from the bottom of the teaching wafer to the target
should be within 1 mm of the Z distance used to create the target configuration file.
The acceptable range for the Z distance is displayed in the Set Target Criteria dialog
(see
•
Target configuration file.
You chose the wrong target configuration file or the
target configuration file is not correct. Verify that you are using the correct file. For
more information on target configuration files, see
“Creating Target Configuration
.
You can use these X, Y, and Z measurements to adjust the equipment to center the target in the
sight ring.
