A reflow oven is a machine primarily used to reflow solder surface mount electronic components onto a printed circuit board (PCB). For mass commercial use, the reflow oven takes the form of a long tunnel with a conveyor on which the circuit board moves. For prototyping and hobby use, the circuit board can be placed in a small oven with a door. An example of a thermal profile for reflow soldering. Commercially available continuous reflow ovens contain multiple individually heated zones with individually controlled temperatures. The PCB to be processed is supplied to the oven and each zone at a controlled speed. Technicians adjust conveyor speeds and zone temperatures to achieve known time and temperature profiles. The profile used depends on the requirements of the circuit board being processed.
Thermal profiling measures multiple points on the circuit board to determine the thermal excursion received during the soldering process. In the electronics manufacturing industry, SPC (Statistical Process Control) helps determine if the process measured by the reflow parameters defined by the soldering technique and component requirements is controlled. A reflow oven is a machine primarily used to reflow solder surface mount electronic components onto a printed circuit board (PCB). The board temperature reaches its highest point in the reflow region. The reflow process melts the solder and melts the solder joints. At high temperatures, the flux reduces the surface tension of metal joints, causing metallurgical bonds. This will combine and melt the solder powder. Traditional reflow soldering processes typically have four stages, called "zones," each with a specific thermal profile. Preheating, thermal immersion (often simply abbreviated as immersion), reflow, and cooling.
A typical reflow temperature range for lead-free (Sn / Ag) solder is 240250 ° C, which is 4080 seconds above 220 ° C. Note that the recommended Sn / Pb reflow temperature range is less important and that slight temperature changes in devices and components generally do not cause soldering problems. Read more...