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Technology

 

Soldering under vacuum

Soldering under vacuum is a technology that provides excellent results for all soldering applications. Vacuum is used in several places during the process execution:

  • One or several evacuations of chamber followed by filling with pure Nitrogen gas helps to remove any residual water and Oxygen from the chamber.
  • A diluted atmosphere during cleaning step enables faster transport of the formic acid molecules enabling in-depth cleaning of surfaces.
  • Vacuum can be used to remove the residues after cleaning step that goes faster compared to purging the chamber with nitrogen.
  • Using vacuum while the solder is in molten phase helps for removing the voids.
  • In some applications when hermetic encapsulation is required we need to cool down in vacuum.

Void-free solder joints

  • Critical for removing of voids is that we evacuate the chamber once solder starts melting. At this point the voids start to expand in the form of bubbles and leave the molten solder.
  • Once this bubbling out is complete we fill up the chamber with nitrogen that presses both surfaces against each other.
  • Our positive pressure configuration of VSU28 model enables even further pumping the chamber. Thus the voids' size is even extra reduced.

Fluxless soldering using formic acid

The possibility to use formic acid (HCOOH) in combination with Nitrogen results in a cost-efficient and stable soldering process, reducing oxide film formation while no fluxing agent is needed in the process. The formic acid surface activation provides good results with respect to void rate across the surface.

The formic acid (enriched with Nitrogen) removes oxide films, which inhibit the soldering process. The formic acid is applied by a bubbler, integrated in the machine. Nitrogen is blown through the bubbler, where it is enriched with formic acid and released into the chamber.

How does the chemical reaction work?

Metal Oxide + HCOOH -> Metal + CO2 +H2O

At temperature over 150-200°C the metal oxide film on the surface is reduced to clean metal surface. The gaseous products CO2 and water are simply purged with dry nitrogen and exhausted to the atmosphere.

The advantages of this process are the following:

  • safety engineering is less complex compared to processes using hydrogen
  • it is cost efficient
  • it is easy to control (our programmable controller provides very high accuracy of execution)
  • it is unnecessary to use fluxing agents
  • no oxidized surfaces

Systems

 

VSU 12

Programmable vacuum soldering oven with a heating area of 100mm x 100mm

 

VSU 20

Programmable vacuum soldering oven with a heating area of 200mm diameter

 

VSU 28

Programmable vacuum soldering & brazing oven with a heating area of 260mm x 210mm

 

 

Highlights

 Compact design                 Formic Acid bubbler

 Single phase supply          Air cooling

 

  

Highlights

Compact design          Cost effective process     Cooling under vacuum

Integrated water chiller Easy maintenance          Smart thermo regulator

Formic Acid bubbler     Single phase supply

 

  

Highlights

Compact design        Easy maintenance     Smart thermo regulator

Formic Acid bubbler  Dual Infrared heating   Additional lamps cooling

Positive pressure

Overview

Infrared lamps placed under the tooling plate heat it up. The tooling plate has a square form with dimensions 100mm x 100mm and can be made of any suitable material. It can also be prefabricated with custom openings for fixtures inside it. The tooling plate can be replaced together with the parts on it. This enables serial production. Nitrogen flow blows from the chamber bottom against the tooling plate and thus cools it down. The chamber itself is air cooled.

 

Overview

The vacuum reflow oven is equipped with a hot plate made of solid Aluminium, coated with ceramic. Another water cooled plate is mounted beneath the hot plate. During cooling the cold plate is lifted up and pressed against the hot plate, thus cooling it quickly. This feature also enables cooling under vacuum.

Overview

Infrared lamps placed under (or optionally, above) the tooling plate heat it up. The tooling plate is in a rectangle form with dimensions 260mm x 210mm can be produced of any suitable material also with custom openings for fixtures inside it. Design enables loading of tooling plate inside the chamber together with the parts on it - this enables serial production. Process cooling by means of Nitrogen flow that blows from the chamber bottom against the tooling plate. The chamber itself is water cooled. An external water chiller is required if not ordered with mounting rack MR23CP

Specifications

Maximum temperature 450°C
Heated area 100mm x 100 mm
Clearance above heater plate 35 mm
Ramp heat up / cool down 250°C/min
Control deviation +/- 0.5°C
Heating / cooling type Infrared heating / Nitrogen flow
Temperature measurement 1 x fixed & 1 x free T/Cs; K-Type
Pressure measurement Integrated pressure transmitter
Maximum vacuum 5x10-4 mbar
Formic acid bubbler 40ml container, integrated in front panel
Chamber cooling Air cooling
Display 2.8" LCD with touch screen
Dimensions 285mm (W) x 370mm (D) x 210mm (H) with closed lid
Weight 10 kg
Power supply Single phase / 190V-240V, 50/60Hz

 

Specifications

Maximum temperature 400°C
Heated area 200mm diameter
Clearance above heater plate 45mm
Ramp heat up / cool down 120°C - 150°C/min
Control deviation +/- 0.5°C
Heating / cooling type Resistive heating / lifting cold plate
Temperature measurement 1 x fixed & up to 3 x free T/Cs;  K-Type
Pressure measurement Integrated pressure transmitter
Maximum vacuum 5x10-4 mbar
Formic acid bubbler 40ml container, integrated in front panel
Chamber cooling Water cooling with integrated chiller
Display 7" LCD with touch screen
Dimensions 550mm (W) x 615mm (D) x 400mm (H) with closed lid
Weight 35 kg
Power supply Single phase / 190V-240V, 50/60Hz

 

Specifications

Maximum temperature 650°C
Heated area 260mm x 210 mm
Clearance above heater plate 45mm
Ramp heat up / cool down 250°C/min
Control deviation +/- 0.5°C
Heating / cooling type Infrared heating / Nitrogen flow
Temperature measurement Up to 4 x free T/Cs; K-Type
Pressure measurement Integrated pressure transmitter
Maximum vacuum 5x10-4 mbar
Formic acid bubbler 40ml container, integrated in front panel
Chamber cooling Water cooling / external chiller is required
Display 7" LCD with touch screen
Dimensions 550mm (W) x 615mm (D) x 400mm (H) with closed lid
Weight 42 kg (55 kg with pressure option)
Power supply 3 phase / 190V-240V, 50/60Hz

 

                        

 

                        

                     

                      

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