Nexus_en - 第6页
6 Example vacuum heating process Reliable vacuum processes for impro ved quality Increased productivity and quality advantages can be achieved in the production of power electr onics by means of vacuum soldering. V acuum…
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Operating principles
Heating and cooling
A major benet of the Nexus contact soldering system is that the heating or cooling gradient can be predened based on pre-
determined parameters. The gradients can be preset as required. Within these specication limits, the temperature is adjusted
automatically by the Nexus so that these limit values are not exceeded. This eliminates the possibility of a malfunction of the
assembly to be soldered.
The heating output of the Nexus has been designed for a uniform heating process when fully loaded with high-mass assemblies
meaning that short cycle times are also no problem. Sensor components determine and verify the temperatures recorded on the
goods carrier support.
0
50
100
150
200
250
300
2200 2300
2400 2500
2600 2700 2800
Temperature in °C
Time in s
Set value
Controller 1
Controller 2
Controller 3
The vacuum soldering process generates temperatures of
up to 400 °C and is an ideal solution for void-free and flux-free
applications. The Nexus not only provides your manufactu-
ring operation with advantages for the soldering process, but
rather for bonding processes as well.
heating plate
PCB cooling
hermetically sealed process chamber
direct
heat transfer
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Example vacuum heating process
Reliable vacuum processes
for improved quality
Increased productivity and quality advantages can be
achieved in the production of power electronics by means of
vacuum soldering. Vacuum provides for oxide-free processes
as well as improved wetting, and thus for more effectively
lled solder joints. Beyond this, vacuum drastically reduces
the number of voids in solder joints and supports processes
such as plasma cleaning and gas exchange for advanced
packaging. Temperatures of up to 400 °C are possible with
Nexus.
without vacuum with vacuum
400 400
300 300
200 200
100 100
0 2 4
vacuum for
void-free solder joints
evacuate and ood
with nitrogen
vacuum and input, e.g.,
formic acid for oxide-free
wetting surfaces
heat up to
solder temperature
activation
phase
pre-heating
phase
cooling phase
solder temperature
6 8min
1000
°C °C
1000
hPa hPa
0 0
0 0
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Controlled chamber pressure
A controlled gas sampling system via a vacuum pump from the process chamber prevents overpressure
during controlled flushing via a separate proportional valve for feeding into the process chamber; thus each
pressure level can be set as required using a software programme.
controlled chamber pressure with nitrogen atmosphere
pressure level constant
proportional valve
for nitrogen input
vacuum pump to control the chamber
pressure of 0 - 1000 mbar