f. Thin Small Outline Package (TSOP)
Components
Removing and replacing a TSOP component
will be done with the R-1319, using the same
procedure used to remove and replace an
OMPAC.
Place the circuit board in the circuit board hold-
er. Select the proper heat focus head and
attach it to the heater chimney. Position the
TSOP component under the heat-focus head.
Lower the vacuum tip and attach it to the com-
ponent by turning on the vacuum pump. Lower
the focus head until it is approximately 1/8”-1/4”
(0.3cm-0.6cm) above the component. Turn on
the heater and wait until the TSOP lifts off the
circuit board.
Once the part is off, turn off the heat, grab the
part with a pair of tweezers, and turn off the
vacuum pump. Prepare the circuit board for the
new component by applying solder paste flux to
the solder pads. Position the circuit board under
the heat-focus head, lower the head to approxi-
mately 1/8”-1/4” (0.3cm-0.6cm) above the
board, and turn on the heat. When the solder
left behind on the pads reflows, turn off the heat
and raise the heat-focus head. Remove the cir-
cuit board from the holder and inspect the pads
to ensure that the solder has flattened out and
that there are no solder shorts. Clean the area
with alcohol and a small brush.
Once the preparation is complete, place the cir-
cuit board back in the circuit board holder. Add
solder paste flux to the solder pads and place
the new component on the circuit board. Posi-
tion the heat-focus head over the component
and lower it to approximately 1/8”-1/4” (0.3cm-
0.6cm) above the carrier. Turn on the heater
and wait for the component to reflow.
Once the component reflows, raise the heat-
focus head and wait approximately one minute
for the part to cool. Remove the circuit board
and inspect the repair. No cleaning should be
necessary.
g. Shields
Removing and replacing the shields will be
done with the R-1319, using the same proce-
dure used to remove and replace TSOP and
OMPAC components.
Place the circuit board in the circuit board hold-
er. Select the proper heat focus head and
attach it to the heater chimney. Add solder
paste flux around the base of the shield. Posi-
tion the shield under the heat-focus head.
Lower the vacuum tip and attach it to the shield
by turning on the vacuum pump. Lower the
focus head until it is approximately 1/8”-1/4”
(0.3cm-0.6cm) above the shield. Turn on the
heater and wait until the shield lifts off the circuit
board. Once the shield is off, turn off the heat,
grab the part with a pair of tweezers, and turn
off the vacuum pump. Remove the circuit board
from the circuit board holder.
To replace the shield, add solder to the shield
if necessary, using a micro-tipped soldering
iron. Next, rub the soldering iron tip along the
edge of the shield to smooth out any excess
solder. Use solder wick and a soldering iron to
remove excess solder from the solder pads on
the circuit board. Place the circuit board back in
the circuit board holder. Place the shield on the
circuit board using a pair of tweezers. Position
the heat-focus head over the shield and lower it
to approximately 1/8”-1/4” (0.3cm-0.6cm) above
the shield. Turn on the heater and wait for the
solder to reflow.
Once complete, turn off the heat, raise the heat-
focus head, and wait approximately one minute
for the part to cool. Remove the circuit board
and inspect the repair. No cleaning should be
necessary.
h. RF PA (U105)
The procedure for removing and replacing the
RF PA is very similar to the procedure for
removing and replacing an OMPAC or a TSOP
component. But because the the device is
large, extra heating time is required to flow the
pads. And as a result, neighboring components
(especially those on the opposite side of the cir-
cuit board) will heat, reflow, and may
inadvertently move. Be careful when performing
the following procedure.
(1) Refer to Figure 40-17 for
RF PA nomenclature.
To remove the RF PA, add flux to the
leads of the device, and use a soldering
iron and pair of tweezers to heat and lift
each lead free and clear of its respective
solder pad on the circuit board. Use the
R-1319 Rework Station and the heat- focus
head designed especially for removal of the
RF PA. Attach the heat-focus head to the
chimney heater. Adjust the temperature
control to approximately 415 degrees F
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