Innovative technology
for innovative products

Vapor as an energy transfer medium is one of the most effective methods for heating assemblies. The efficiency is many times higher than, for example, heating by convection.

Vapor phase soldering – also known as condensation soldering – uses the energy released during the change of state of the heat transfer medium from the gaseous to the liquid phase to heat the assembly. This phase change, or condensation, occurs over the entire surface of the solder until the assembly reaches the temperature of the vapor. The high density of the vapor and the liquid film formed over the entire product during condensation allow the entire heating and soldering process to take place in an oxygen-free environment. The amount of heat transferred is linear to the heating energy supplied and is controlled via this.



With just a few parameters to the desired soldering profile

Process reliability

Intrinsically safe soldering process; No overheating of assemblies


100 % oxygen-free process with best wetting properties


Up to 70 % savings of the required energy in production


No waiting times for product changeover

The soldering process

Step 1

  • Assembly (1) is waiting for the start of the soldering process
  • Process liquid (2) is heated up by heating elements (3) to its boiling point (e. g. 230° C for leadfree applications)
  • Boiling point is equal to the process temperature

Step 2

  • Energy supply generates vapor (4)
  • Vapor zone builds up and is permanently controlled by sensors
  • Vapor temperature is equal to the boiling temperature of the process liquid
  • Soldering process can start

Step 3

  • Assembly enters the vapor zone
  • Vapor condenses on the assembly and creates a closed liquid film around the complete assembly
  • Vapor zone stabilizes at the level of the assembly

Step 4

  • Liquid film (5) excludes oxidation completely
  • Through the liquid film, the energy is transferred on the assembly
  • The energy transmission is controlled through the vapor creation and therefore also the  condensation

Step 5

  • With this controlled energy transmission/condensation, the adjusted
    soldering profile is reached
  • Assembly is heating up to vapor temperature
  • condensation stops automatically and vapor zone rises again

Step 6

  • Soldering process is finished
  • Assembly leaves the vapor zone
  • Process liquid evaporates completely
  • Dry assembly moves to the cooling zone

Simple, efficient, safe!

  • No overheating of the components, as the boiling point of the heat transfer medium determines and limits the maximum soldering temperature.
  • Uniform heating on the entire assembly, even with different components and masses.
  • Oxidation-free soldering process without additional use of protective gases such as nitrogen.
  • Much more efficient use of energy than with known soldering technologies such as convection or radiation. The heat transfer coefficient of the medium used is significantly higher than with air.
  • In combination with a vacuum process, almost completely void-free solder joints can be achieved.
  • And the best of all, power consumption in production can be reduced by up to 70%. That saves your resources and the environment.

Multi Vacuum -
The soldering process of the future

Achieve significant improvements in the performance and lifetime of your products by using Multi Vacuum technology!

Dynamic Profiling - Soldering the simple way!

Monitor all process sequences during ongoing production and save significant time when creating soldering programmes!

Permanent Filtration System

The permanent filtration system continuously filters the heat transfer medium during operation. This reduces the contamination of the plant and significantly extends the intervals for maintenance and cleaning.

Heat transfer medium (Process Liquid)

The heat transfer medium is an odorless and
and colorless liquid, chemically inert and electrically non-conductive. It has a fixed boiling point, is not a hazardous substance as defined in the German Ordinance on Hazardous Substances and is harmless.

Typical industries


The very good soldering quality significantly increases the lifetime of mechanically highly stressed assemblies. Fewer rejects and warranty claims due to vapor phase soldering.


High quality and gentle soldering of high-power LEDs. And that up to a maximum size of 1,500 x 620 mm.


Optimal performance under the most extreme working conditions. Leading companies in space technology rely on ASSCON’s vapor phase soldering.



Safety-relevant assemblies require maximum reliability. In combination with vacuum, voids can be almost completely avoided.

Power module production

Maximum performance of electronic assemblies are a must for power modules. Large area solder joints with void rates < 1 % with vapor phase and Multi Vacuum.

Renewable energies

Saving energy and protecting the environment – essential features of vapor phase soldering, which is also often used in the field of renewable energies.

Do you have any further questions?

What does simplicity of process mean?

With simplicity we evaluate the easy creation of soldering profiles with three parameters. That is all that is needed to create a linear profile on a vapor phase.

What do you mean by process reliability?

Due to the physically self-regulating process, no overheating of the assemblies can take place. The maximum process temperature corresponds to the boiling point of the medium used. This cannot be exceeded due to the process and is therefore safe.

For which products is vapor phase soldering best suited?

In principle, the process is suitable for all products. In particular, complex and heavy assemblies with a wide range of component sizes can be soldered optimally with the vapor phase.

Does vapor phase soldering save energy?

Absolutely. The vapor phase soldering process is highly efficient and requires only about 30% of the energy needed by a conventional convection reflow soldering system. Thus, up to 70 % of the power consumption can be saved.

Is the process medium harmful to health?

No, ASSCON uses a process medium which is chemically inert and therefore absolutely harmless to health!