A reflow oven is an electronic heating device that is used to mount electronic components on printed circuit boards (PCB) through surface mount technology (SMT). This technique is widely applied in the electronics manufacturing industry because it enables easier construction of electronic devices. There are several types of reflow ovens. They are instrumental in ensuring that electrical components are properly mounted and that the electrical connections on the circuit board are secured through reflow soldering techniques.
Surface mount technology is the preferred technology in electronics manufacturing because it is cost effective in comparison with other techniques, such as through-hole processes. Even though it is possible to solder most SMT components manually, it is very time consuming because each component has to be soldered individually. This problem was solved with the invention of the reflow oven.
A reflow oven allows the user to control the temperature while heating the PCB and soldering components together with soldering paste. To experience a good reflow, the thermal profiling must be set up systematically. This is done by first preheating the oven to ensure that the PCB temperatures are hot enough to dry the solder paste. Immediately after thermal stabilization is achieved, the PCB board is heated quickly while ensuring that the temperature of the PCB is higher than the reflow.
Infrared and convection reflow ovens have multiple zones, and their temperatures are controlled individually. Each zone consists of several heating and cooling sub-zones. The heating source is comprised of ceramic infrared heaters, and the heat is transferred through radiation.
A vapor phase oven is another type of reflow oven that heats the PCB with thermal energy. This energy is derived from the phase change of a heat transfer liquid that condenses on the PCB. The choice of the liquid to use in the oven is generally determined by the preferred boiling point of the soldered alloy being placed in the oven.
An industrial reflow oven is used for circuits that require fast heating and cooling. The quicker the heating process is completed, the less thermal stress is placed on the components. These ovens generally are used in situations that revolve around very large printed circuit boards.
Many hobbyists often choose to build their own reflow ovens. These reflow ovens are often created from household appliances, such as microwave ovens, which use infrared rays as the source of heat. One drawback to homemade ovens is that the cooling process is difficult to implement.
