Description

ASSCON’s vacuum soldering process combines the advantages of the vapor-phase with the
vacuum process.

Power components require a homogeneous metallic connection
with the PCB to transfer the required current.
Assemblies
soldered in ASSCON’s vacuum process exhibit
greatly improved solder joints relative to void formation.
Particularly when using lead-free solders the wetting properties
decrease and the solder joints exhibit an increased
occurrence of voids and entrapments.
Through use of the vacuum process the developing inclusions
are extracted before the solidification phase.

Vacuum soldering process
In the process zone of the vapor-phase soldering machine
the assembly is pre-heated and soldered under inert conditions.
The vacuum module is integrated in the process zone.
Immediately
after completing the soldering process the
vacuum module seals the assembly from its environment
and starts the evacuation.
The negative pressure removes voids and entrapments
from the solder which is still in liquid state.
The vacuum module is ventilated and opened again.
Subsequently the product moves through the cooling zone
to the unload station.

Machine design
The machine structure is self-supporting. It consists of a
load and unload stations, soldering zone, vacuum module,
cooling and controller.
Through the use of the load/unload station the assemblies
are moved to the process on a universal work piece carrier
and after the automatic cycle is completed the assemblies
are ready to be removed.
The key unit of the compact multi chambers machine is the
process chamber made of stainless steel. The large area
heaters are mounted on the outside and insulated against
external heat radiation. High quality sensors for the heaters,
fluid, vapor and cooling zone temperature guarantee
utmost process reliability.
The vacuum module consists of the evacuation unit mounted
in the process chamber where it is secured with quicklocks
for fast and easy removal for maintenance. Pump,
valves and sensors are integrated in the base.
The efficient cooling zone of the machine is equipped with
a special blower system, which circulates the medium and
flux residues, emanating from the assembly, through a
cooling cassette and on to an internal filtration cycle.
An automatic filtration system for microfiltration of the heat
transfer medium is available.
An integrated exhaust system is available to remove vapors
and odours from areas outside the process chamber which
occur during the de-gassing of the printed circuit board.
The controller is preprogrammed to accept the connection
of an external exhaust.
The machine controller sits in an integrated control box and
contains the switch, control, regulators and safety/fuse elements
for all functional units.

Specifications