Metcal QX2 Manuel D'utilisation page 5

Install a vacuum cup onto the vacuum tube extending from the reflow head.
(See Vacuum Cup Attachment, p.11)
Select a rework nozzle that corresponds with the component you wish to remove. Insert the
nozzle into the reflow head by firmly pushing the nozzle up until it clicks into place.
(See Nozzle Attachment, p.12)
Lift the heater head until it locks in the up position to allow clearance. Raise the heater head fully
by rotating the Z-axis knob until it comes to a stop. Place the printed circuit board that you wish
to rework on the work tray or board holder. Position the board holder or work tray so that the
component to be reworked can be easily accessed by the rework nozzle.
Lower the heater head assembly until it locks in the down position. Move the work tray or
board holder so that the component to be removed is centered with reference to the nozzle.
Fine adjustments in the theta rotation axis can be made by rotating the lever.
Note: The component should be centered with respect to the nozzle so the leads do not hit
the nozzle when the component lifts from the board.
Using the Z-axis knob, lower the heater head until the nozzle completely encapsulates the
component. The nozzle should remain 1-2 mm above the component leads, and should not
be in contact with the component or PCB.
Ensure that the mode selector is in the Remove position, and that the main power switch is on.
Switch the airflow selector to the setting that best corresponds with the application. If you
are unsure which setting to use, start with the lowest setting, Setting 1. This setting is the
safest for the component and the PCB. To achieve faster removal times, increase the airflow
setting. WARNING: Higher airflow settings will increase the component temperature rise rate.
The table below provides sample airflow settings at the default Temperature Setpoint of
350ºC for three component sizes to maintain maximum component temperature rise rates
below 5ºC/s.
Component Setting
PLCC 20 1
QFP 100 1, 2
QFP 208 1, 2, 3
Press the Start/Stop button. You will now notice the hot air flowing from the flutes of the nozzle
and the timer counting up. WARNING: The nozzle and the exhausted air will be hot.
If you have a preheater that is properly connected to the power supply, the preheater
will start automatically at the same time. If you do not wish to use the preheater, you
may turn it off. Alternatively you may turn it on before turning on the power supply.
(See Preheater Operation, p.10)
When the removal cycle is complete, the component will automatically lift from the printed circuit
board. The preheater will shut down and the hot air from the power supply will automatically stop.
The removal time will remain stored for a subsequent attachment cycle.
Lift the nozzle up by raising the heater head. The vacuum cup will continue to hold the
component. Flip over the nozzle removal tool so that the bottom plate is facing up and
acting as a scoop. Place the tool directly underneath the component and push the Start/Stop
button. The component will fall into the tool and the vacuum pump will turn off .
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Copyright © 1999, Metcal, Inc. All Rights Reserved 7036-0541 Rev. A
REMOVE MODE ATTACH MODE
After preparing the site, align the component you wish to attach to the PCB with its
mating land pattern.
Rotate the mode selector so that it is in Attach mode. You will notice that the vacuum
tube automatically lifts out of the way.
Lower the heater head and move the work tray (or optional board holder) so that the
component to be attached lies centralized in reference to the nozzle. Fine adjustments
can be made to the theta (rotation) axis at this point by rotating the theta rotation lever.
Lower the heater head until the nozzle completely encapsulates the component to be
attached by rotating the fine Z-axis adjustment knob. The nozzle should remain 1-2mm
above the component leads, and should not be in contact with the board or component.
You will notice the time of the last full cycle is displayed on the controller. You may
user the +/- keys to adjust the rework cycle time. If you just performed a removal cycle,
the time displayed is that removal time. If you are re-attaching the same component,
you may wish to add 15–30 seconds to the time to ensure complete reflow.
Press the Start/Stop button. The hot air cycle will now begin, counting down from the
displayed value. Once the timer gets to ":00" the unit will shut off airflow and
indicate that the placement cycle is now complete.
Copyright © 1999, Metcal, Inc. All Rights Reserved 7036-0541 Rev. A
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