A comparison of vapor-phase, infrared and hot-gas soldering

The three most important reflow methods (vapor-phase, infrared, and hot-gas) are discussed. These methods are compared and the advantages and disadvantages of each are demonstrated. Vapor-phase and infrared are the most frequently used reflow methods. Three main reasons for using vapor-phase reflow are given: heating of printed-circuit boards and components is independent of geometry; heating is independent of package density; and the maximum achievable temperature is limited by the boiling point of the liquid used. Infrared soldering offers certain advantages which are not found in the vapor-phase process. Infrared soldering does not have such an extreme heating rate. The furnaces need much less service and create no problem with the environment