Measuring Gas Phase Thermal Boundary Dynamics across Unequal Copper Density Substrates
Vapor phase reflow eliminates thermal deltas across unequal copper density substrates by transferring latent condensation energy at constant fluid temperatures.
Galden LS230
Liquid Medium
Fluorinated organic fluids with precise boiling points serve as primary heat transfer agents in vapor phase reflow soldering systems. Utilizing galden ls230 allows manufacturers to achieve a maximum reflow temperature of 230 degrees Celsius, which matches the requirements of lead-free solder alloys. This fluid is chemically inert and does not leave residues on the assembled circuit boards after processing.
Its properties prevent thermal damage to sensitive electronics by ensuring that components are never exposed to temperatures above the boiling point.
Vaporization Cycle
Boiling the liquid creates a dense, saturated vapor zone that excludes oxygen and prevents component oxidation during the soldering process. The vapor condenses on the cold assembly, releasing its latent heat of vaporization to warm the board and melt the solder paste. Because the heat transfer coefficient of the condensing vapor is high, the assembly warms up quickly and evenly regardless of the thermal mass of individual components.
This uniform heating reduces thermal stress and prevents defects like component tombstones or incomplete solder joints. The liquid is collected, filtered, and reused in the closed-loop reflow system to minimize consumption.
Thermal Control
Process safety in vapor phase soldering relies on the chemical stability and non-flammability of the fluorinated fluid. Solder reflow occurs without the risk of overheating because the temperature of the vapor cannot exceed the boiling point of the liquid. These characteristics make it a reliable choice for complex assemblies that feature large components alongside small passive chips.