Asyst Technologies VersaPort 2200, Техническое руководство

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Page 26 2000-1252-01 Released Rev. C
VersaPort 2200 Technical Manual
Chapter 2: Theory of Operation
VersaPort Components
a
• Wafer Protrusion, Horizontal View Sensor
The laser beam transmitted from the second beam splitter is reflected off two
mirrors at the corners of the laser assembly and back across the cassette opening
and through an aperture onto the wafer protrusion sensor. This sensor detects
any wafers protruding beyond the front of the cassette. A protruding wafer could
be damaged as the elevator is returning the Pod top to the cassette. Activation of
the wafer protrusion sensor causes the elevator to halt and the wafer seater
mechanism to seat the out-of-position wafer.
Excessive Wafer Protrusion Sensor, Vertical View
The excessive wafer protrusion sensor, vertical view, uses one IR emitter and one IR
receiver to create a break-the-beam sensor system. If a wafer is positioned too far out of
the cassette for the wafer seater to correct, the wafer will interrupt the beam sent from the
emitter to the receiver, causing the VersaPort to immediately stop so the wafer can be
manually reseated into the cassette slot.
Motor Controls
The VersaPort contains six motors (five if the cassette shuttle option is not present); two
dc servo motor (one port plate elevator and one cassette shuttle), two dc stepper motors
(one Pod latch and one wafer seater), one dc motor (Pod door lock/unlock mechanism),
and one single speed motor (air exhaust).
F
IGURE
8
Laser Detector Example (viewed through port plate)
200 mm
CASSETTE
SLOT
SENSOR
WAFER
POSITION
SENSOR
WAFER PROTRUSION SENSOR
BEAM APERTURE
PORT DOOR
MIRRORS
(MIRROR BRACKETS
SET AT 45 DEG)
CASSETTE SLOT
BEAMSPLITTERS
WAFER POSITION
BEAMSPLITTER
(BRACKET SET
AT 37 DEG)
BEAMSPLITTER
(BRACKET SET
AT 45 DEG )
LASER DIODE
670 NM
VISIBLE RED
@<1.0mW CW
BEAM
PATH
SILICON WAFER OUTLINE
(200mm)
(ALIGNED FOR 200mm WAFER)
200mm