Can vapour-phase soldering be done with water?
No, vapour-phase soldering with water is not possible because water does not meet the basic requirements of this soldering process. Its low boiling point, moisture-related issues, and unsuitable chemical properties make water unsuitable for vapour-phase soldering in electronics manufacturing.
Boiling Point: The Crucial Difference
A key factor in vapour-phase soldering is the temperature that can be achieved. This is determined by the boiling point of the medium used. At normal pressure, water has a boiling point of 100 °C. This is significantly lower than the temperatures required for reflow soldering:
- 180 °C for lead-based solders
- 220 °C to 250 °C for lead-free solders
Water vapour cannot reach these temperatures. Therefore, it is physically impossible to reliably solder electronic assemblies using water.
Chemical Properties of Water in Soldering
From a chemical standpoint as well, water is unsuitable for soldering. Unlike specialized heat transfer fluids, water is:
- not chemically inert
- containing dissolved ions
- electrically conductive
- potentially corrosive
These characteristics are in direct conflict with the requirements for safe and stable soldering processes in electronics manufacturing.
Moisture and Risks in Electronics Manufacturing
Another problem is the moisture that would be introduced into the assembly when water is used. As it condenses, water would come into direct contact with the electronic components. This poses significant risks in electronics manufacturing, including:
- corrosion of circuit traces
- short circuits caused by conductive residues
- delamination of materials
Electronic components are extremely sensitive to moisture. Subsequent drying would be time-consuming and might not always be fully possible.
Temperature Control in Vapour-Phase Soldering: Why Water Is Unsuitable
A key advantage of vapour-phase soldering is its precise temperature control.
However, water does not allow for the same precise control of evaporation and condensation processes as specially developed fluids. Uniform and reproducible heat transfer requires stable thermal properties, which water does not provide.
Galden as a Standard Heat Transfer Fluid in Vapour-Phase Soldering
Instead of water, specially developed fluids such as Galden are used in vapour-phase soldering.
These heat transfer fluids offer:
- Precisely defined boiling points (165 °C to 260 °C)
- uniform heat transfer
- chemical stability and inertness
- electrical non-conductivity
As a result, they enable precise temperature control, uniform heating, and reliable process control—all of which are essential for high-quality solder joints.
Why Can’t Vapour-Phase Soldering Be Done with Water?
Water does not meet either the thermal or the chemical requirements of the process.
The low boiling point, moisture-related issues, and unsuitable material properties make their use impossible. Specialized heat transfer fluids such as Galden are therefore essential for ensuring the necessary process reliability and quality in modern electronics manufacturing.
Vapour-Phase Soldering for Reliable Soldering Processes
Learn more about vapour-phase soldering and the benefits of precise and uniform heat transfer.
