Atmospheric Pre-aligner Manual
4000-0015 Rev 1
35
Maintenance and Diagnostics
The pre-aligner has no user-serviceable parts and maintenance is minimal.
When maintenance occurs, the equipment is fully de-energized, which
results in a Type 1 task hazard rating. Work defined as Type 1 is
considered safe.
Use the Equipe Diagnostic software to verify any hardware problems.
Although the diagnostic steps are presented here in numerical order, you
do not need to use them consecutively. For example, if you suspect that
the z axis needs to be adjusted, you would use only the r & z Home Offset
Diagnostic Step to check the home offset.
Maintenance
If your environment is Class 10,000 or more, you will need to regularly
clean the CCDs and possibly the LED.
To determine whether or not the CCDs need to be cleaned, run the CCD
and Chuck Diagnostic Step. When a wafer completely covers the CCD,
the number should be as high as 2720. When the CCD is not covered, the
number should be very low, about 36. Note: For models built before
October 1998, the numbers might be different.
Before cleaning the CCDs, disconnect the pre-aligner. To clean the CCDs,
use one of these methods:
• Tip the pre-aligner on its side and blow compressed dry air against the
three CCDs.
• Wet a cotton swab with isopropyl alcohol and lightly brush the tops
and sides of the three CCDs. Then blow compressed dry air on the
CCDs to dry them.
Cleaning the LED is more difficult, and unless the environment is
extremely harsh, is not necessary.
1. Locate the LED on the underside of the pre-aligner top.
2. Dampen a lint-free cloth with isopropyl alcohol.
3. With the pre-aligner tipped up on its side, drop the cloth through the
opening so that the ends of the cloth extend through each side.
4. Set the pre-aligner down on a flat surface.
5. Pull the cloth back and forth gently across the LED.
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