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Figure 3-12B.—Motorized vacuum/pressure solder removal. PRESSURE MODE.
Figure 3-12C.—Motorized vacuum/pressure solder removal. HOT AIR JET MODE.
Motorized Vacuum Method.—In the motorized vacuum method, the heated tip is applied to the
solder joint. When melted solder is observed, the vacuum is activated by the technician causing the solder
to be withdrawn from the joint and deposited into the chamber. If the lead is preclipped, it may also be
drawn into a holding chamber. To prevent SWEATING (reforming a solder joint) to the side walls of the
plated-through hole joint, the lead is "stirred" with the tip while applying the vacuum. This permits cool
air to flow into and around the lead and side walls causing them to cool.
Motorized Pressure Method.—In the pressure method, the tip is used to apply heat to a pin for
melting a sweat joint. The air pressure is forced through the hole to melt sweat joints without contacting
