Asyst Technologies VersaPort 2200, Technical Manual

Page: 87 / 288

Released Rev. C 2000-1252-01 Page 69
VersaPort 2200 Technical Manual
Chapter 4: Service
CAP1 – Align Laser Detector System
a
_____7. When the DAC value is less than or equal to 30 (and the bottom screw with
spring is tight) tighten the top screw with spring. Check the DAC value again
and verify it is less than or equal to 30.
_____8. At the PC, press the F4 key to stop calibration.
Adjust Slot Sensor Beam
WARNING
LASER HAZARD
L
ASER RADIATION PRESENT WHEN POWER APPLIED AND
INTERLOCK DEFEATED
. A
VOID DIRECT EYE EXPOSURE
.
_____1. At the PC:
_____a. From the MANUAL Menu select F4 (DAC)
_____b. From the DAC Menu, use the arrow key to select Sensor Alignment.
_____c. From the SENSOR ALIGNMENT Menu, use the arrow key to select Slot
Sensor.
_____2. Wait for the message from the VersaPort. The message should read:
Sensor calibration in progress: SLOT
Adjust sensor until threshold is <30
Press F4 key to stop calibration
DAC #1 threshold = xx
(where xx is the DAC threshold value of the sensor and it could range
anywhere from 0 to 255.)
The DAC threshold value ( xx ) needs to be as small as possible. If the
displayed value is less than or equal to 30, proceed to Wafer Protrusion Sensor
Adjustment.
If the displayed DAC threshold value is greater than 30, adjust the angle of the
beam splitter which directs the laser beam onto the cassette slot-sensor
aperture (see
Figure 19 on page 66 ).
_____3. Use a 0.050 inch Allen wrench to adjust the beam by slightly turning the
adjustment screws (See Figure 21 on page 67 for correct screw). Visually
verify that the laser beam center is hitting directly on the center of the slot
sensor aperture.
NOTE . . .
I
F THE ADJUSTMENT SCREWS ARE TIGHT AND THE BEAM DOES NOT MOVE
,
LOOSEN THE TWO SCREWS WITH SPRINGS ATTACHED APPROXIMATELY
ONE
-
QUARTER TURN
.