Vision_Series_EN - 第14页
14 possible 2-in-1solution for reow soldering VisionXP+ with or without vacuum Energy-ecient, low-maintenance and voidless - Rehm offers innova- tive solutions for reow soldering with a variety of VisionXP+ options. A…
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Power Cooling Unit
Rehm CoolFlow
In order to cool complex modules it is possible to extend
the cooling zones using a power cooling unit. As part of this
process, cold air is fed onto the board from above and below,
where it can be cooled in a more intensive, gentle manner as
a result of the process being extended. The power cooling
unit can be implemented in the form of an extension to the
standard cooling zones under nitrogen atmosphere and
is also available as a separate, downstream module for
increased cooling capacity for insensitive materials under
normal atmospheric conditions.
Rehm Thermal Systems has been working with its partner
Air Liquide to develop an innovative cooling principle for the
effective use of the nitrogen required for inertisation and
designed the rst coolant-water-free reflow soldering sys-
tem with liquid nitrogen cooling. The liquid nitrogen, which
reaches temperatures as low as -196 °C, cools the inside of
the cooling tract, evaporates and is then used for inertisation
whilst in a gaseous state. This not only provides the system
with the necessary coldness, but also the inert environment.
As a result, the coolant water that is re-cooled using a high
amount of energy, as well as the cooling unit and refrigerant
are no longer required at all. This method could save around
17 tonnes of CO
2
and 30,000 kWh per system, per year.
The VisionX-Series transforms the classic cooling tract into a two or four-layer system, depending on the
facility. This design incorporates an active cooling process, water-cooled using heat exchangers follow-
ing an efcient "Closed Loop" system. The process air is cooled in the heat exchangers and then flows
onto the module from above. The air is subsequently sucked underneath, cleaned using a lter system
and is then ready for the next cooling process. Individually adjustable ventilators in each of the zones
make it possible to precisely control the cooling process and influence the cooling gradient accordingly.
Bottom cooling makes it possible to cool high-mass boards
easily and effectively. The cold process air is blown onto the
board in equal measures from above and below in order to
facilitate a particularly homogeneous cooling process and
to reduce tension in the material. It is possible to adjust the
ventilator speeds for each module. This means additional
cooling measures, such as an outfeed belt with ventilators,
are unnecessary thanks to the low outlet temperatures. It is
predominantly modules with inhomogeneous distribution of
the copper positions that will be protected against twisting
and warping as a result of bottom cooling.
Closed Loop System
Bottom Cooling
VXP+
Vac
VXP+ VXS
VXP+
Vac
VXP+ VXS
VXP+
Vac
VXP+ VXS
VXP+
Cooling zone with bottom cooling
Power Cooling Unit PCU
VisionX-Series | Cooling
14
possible
2-in-1solution for reow soldering
VisionXP+ with or without vacuum
Energy-ecient, low-maintenance and voidless - Rehm offers innova-
tive solutions for reow soldering with a variety of VisionXP+ options.
A new vacuum unit now enables convection soldering processes with
or without vacuum – with only one soldering system!
The VisionXP+ with vacuum option reliably removes voids and out-
gassing immediately after melting the solder – while the solder alloy
is completely in the liquid phase. Void rates of less than 2 % are made
possible with vacuum values between 100 mbar – 10 mbar. Pressure
progress and speed can be set individually and moreover be saved
as prole parameter in the product recipe. This integrated solution
results in a more time-efcient and stable production sequence.
A costly rework or rejection of the pcb assembly due to excessive
voiding is obsolete!
Vacuum measured in the process chamber and not at the vacuum pump
Vacuum down to 10 mbar for reducing the number of voids
Three-part conveyor: heating zone, vacuum zone and cooling zone
Automatic positioning of the process chamber to processing or maintenance position
Outstanding cooling performance
Minimal downtime thanks to low maintenance
void ratios
below
2 %
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Opened vacuum chamber of the VisionXP+ Vac
Divided, separately regulated transport system
The VisionXP+ Vac has a tripartite transport system:
pre-heating/peak area, vacuum unit and cooling zone.
All three areas of the transport system can be optionally
equipped with a central support for particularly wide boards.
The possibility of reducing the transportation speed in the
cooling zone when using the vacuum enables the extension
of the cooling time of components and therefore guarantees
an optimum temperature for subsequent process steps. The
throughput of the system is additionally increased with the
expansion of the transport system by a second track.
The vacuum chamber is installed in the VisionXP+ Vac as
an enhancement to the available peak zones. The integrated
pyrolysis and separate ltering of the atmosphere extracted
from the vacuum chamber are additional plus points in terms
of maintenance and cleaning. A generously dimensioned
vertical travel range of the vacuum chamber in the service
position enables good access to the internal mechanisms
during maintenance periods.The automatic running of the
process chamber into the processing or maintenance posi-
tions minimises downtimes and reduces maintenance effort.
All heating zones of the VisionXP+ Vac are regulated indi-
vidually and separated from each other thermally, guaran-
teeing flexible prole guidance and a stable reflow process.
The measurement of a temperature prole with the vacuum
process switched on shows that despite a very low vacuum
of 10 mbar, all prole settings have been fullled (≤ 3 K/s
heating, tL ≤ 90 s, TP ≤ 240 °C). With the help of the heating
integrated into the chamber, the temperature of the compo-
nents inside the vacuum unit can be adapted to the settings
of the most common standards. This rened solution
ensures a time-efcient and stable production process.
Efcient, easy to maintain and void-free
Precise pressure and temperature proling
VXP+
Vac
VXP+
Vac
VXP+
Vac
Pressure and temperature prole of a soldering process with the VisionXP+ Vac
without vacuum with vacuum
VisionX-Series | Vacuum