Solvay Galden^® PFPE

Galden® PFPE is a line of perfluoropolyether (PFPE) dielectric heat transfer fluids with boiling points from about 55°C to 270°C. It’s specifically designed for vapour-phase soldering, electronics heat transfer, reliability testing, and other high-tech applications.

Typical grades include LS215, LS230 among others, each with different boiling points (e.g. 215-230°C). To choose a grade you match the boiling point so that your maximum operating temperature is below the fluid’s boiling point (usually at least ~10°C margin). Also consider pour point and viscosity to ensure pumpability at lower temperatures.

Galden® PFPE has excellent dielectric strength (~40 kV at 2.54 mm gap), very high volume resistivity (~1×10¹⁵ Ω⋅cm), dielectric constant ~2.1, making it ideal for use where dielectric isolation is needed (e.g. vapour-phase soldering).

No. Galden® PFPE is a completely inert, non-flammable heat-transfer fluid with no flash point, no fire point, and no explosion risk. Its perfluorinated molecular structure ensures chemical stability and zero reactivity, even under high temperatures.

In vapour-phase soldering, Galden® PFPE provides a controlled, oxygen-free environment — soldering takes place in an inert medium with zero oxygen exposure, which eliminates oxidation on solder joints and ensures cleaner, stronger, and more reliable connections.

Engineers and manufacturers choose Galden® PFPE because it:

• Creates a stable, inert vapour blanket for precise and uniform heat transfer.
• Prevents oxidation and contamination of sensitive components.
• Delivers repeatable, oxidation-free solder quality ideal for high-reliability industries like aerospace, medical, and defence electronics.
• Requires minimal maintenance due to its chemical inertness and long service life.

In short, Galden® PFPE is preferred not only for its safety but for enabling consistent, oxygen-free soldering conditions that improve quality and process control.

For example, LS215 has density ≈1.80 g/cm³, LS230 ≈1.82 g/cm³ at 25 °C; kinematic viscosity in that region ~3.8-4.40 cSt; heat of vaporisation ~63 J/g. These affect fluid circulation, vapor behaviour, and system design.

Because heating happens via condensation of vapour, no region of the PCB is exposed to temperatures above the fluid’s boiling point. This means no overheating of components, better thermal uniformity across different component masses, and overall gentler soldering. Also, the absence of air reduces oxidation.

Galden® PFPE is compatible with metals, many plastics, and elastomers. Because of low surface tension, careful attention is needed for seals/gaskets/plastics to avoid swelling or extraction. Also ensure materials in contact are rated for the operating temperature range.

Benefits include non-flammability, no explosion hazard, good chemical stability, minimal evaporative loss in higher boiling grades, long shelf-life, and safer working environment. To preserve these, controls are needed: keep operating temperature below boiling point margin, maintain fluid purity, avoid moisture ingress, monitor for degradation, and use proper storage.