Vapour phase ovens - also called condensation brazing - is based on similar physical principles to heat pipe brazing. An inert liquid is brought above its boiling point, causing a vapour phase to form just above the surface. This liquid is a specially developed medium called Galden® which boils between 230 °C and 240 °C, depending on the type. This newly formed steam transfers energy from the heat source to one or more "heat sinks". In this case, these heat sinks are your PCB, your components and the solder paste applied. The vapor condenses on the cooler surfaces first, transferring more energy to these areas and gently heating your board. The solder paste will melt once your PCB reaches the appropriate temperature. Also, the maximum temperature it can reach is limited by the boiling point of Galden®. Once you remove the assembly from Vapor Phase One, the solder will solidify.
