PCB Reflow Oven
Printed circuit boards provide mechanical support for electrical and electronic components. When fabricating printed circuit boards, manual soldering components is not feasible if the number is large. The reflow soldering process is used to solder the components on the PCB, where the sample with solder paste passes under a reflow oven or a typical bench top reflow oven.
Benchtop reflow oven based on thermal analysis. The temperature data is sent to the bench-top reflow oven, which tells the automatic conveyor to provide the PCB with the required heat, the slope of the heat over time, and the heating of the cycle.
There are several benchtop reflow oven in the market. Some of them are infrared ovens, PCB convection reflow ovens and PCB vapor phase reflow ovens. Infrared benchtop reflow oven uses a ceramic heater that heats in the form of infrared light. They have precise heat and cooling zones that control the time and heat distribution. Some infrared heaters, in addition to infrared ceramic heaters, have a fan to provide convective heat flow. Therefore, they are called convection heated bench top reflow ovens. Some ovens use liquid (such as Krytox) to transfer heat when dew condensation occurs on the printed circuit board. They utilize the energy released when phase changes occur in the heat transfer material, so they are called gas phase bench top reflow ovens.
Usually the medium of heat transfer in benchtop reflow oven is air but due to oxidization of solder as well as copper on PCBs the nitrogen is used instead of air. Injection of nitrogen to work chamber reduces oxygen concentrations thus gives defect free soldering. The trade for defect free soldering is the time that nitrogen takes to fill the chamber and makes oxygen concentration less to an appropriate level.