OPERATION OF THE MJB4
MJB4 - Operation Rev02 01-06 21
3
3.2.8. Basic Pneumatic Settings
Basic pneumatic settings
1 WEC pressure controller
2 Nitrogen purge mask holder controller
3 Reduced vacuum chamber controller
4 Lamp power controller for CPC200
5 Vacuum manometer
6 Nitrogen manometer and controller
7 Compressed air manometer and controller
Compressed Air
The device works reliably at an operating pressure
of >5.5 bar. The pressure must be set correctly on
the pressure reducing valve by a service engineer
and then read from the manometer.
Nitrogen
A nitrogen pressure rated at 1.5 bar must be set on
the pressure reducing valve by a service engineer
and then read from the manometer.
Nitrogen is used to cool the exposure lamp, build up
additional overpressure behind the substrate (hard
contact exposure), as a cover gas for the substrate,
to ventilate the vacuum chamber after vacuum
exposure and for other secondary functions.
Vacuum
The vacuum supplied to the machine should be
-0.8 bar. The vacuum level can be read on the
corresponding manometer.
All main pressures are monitored by
detectors which display an error message
in the display if there is a deviation of
approx. -20%.
Low Vacuum (with controller)
This controller sets the low pressure in the vacuum
chamber between the substrate and mask. The
vacuum is regulated by injecting additional nitrogen
into the vacuum line. This value can be set and read
on the LOW VACUUM CONTACT process screen.
WEC pressure (with controller)
For wedge error compensation, the substrate must
be pushed against the mask with a defined amount
of force. The WEC pressure is used to compensate
for the greater weight of a large chuck. The WEC
pressure must also be proportionally adjusted to the
substrate surface. The pressure for wedge error
compensation can be set to meet specific processor
requirements (value between 0.2 and max. 2.0
[bar]). This can be done using the WEC PRESSURE
setting knob.
The value can be set and read below the WEC
SETTINGS menu item.
N
2
Purge Mask Holder (with controller)
The adjusting station is equipped with nitrogen
flushing to reduce the oxygen content in the space
between the mask and substrate when negative
resist is used. The nitrogen is injected from the back
of the mask holder frame between the mask and
substrate. The volume of nitrogen can be set using
the PURGE MASKHOLDER choke.