What is reflow soldering

Many people are not familiar with reflow welding, because they have not operated or seen it, the concept of reflow welding is very vague, then what is reflow welding?

Reflow is the soldering of mechanical and electrical connections between the solder ends or pins of surface-assembled components and the printed board solder pad by remelting the paste solder preallocated to the printed board pad. Reflow welding is to weld the components to the PCB board, and reflow welding is to mount the devices on the surface. Reflow welding is based on the action of hot gas flow on the solder joint. The gel flux reacts physically under certain high temperature air flow to achieve SMD welding. The reason why it is called "reflow welding" is because the gas circulates in the welding machine to produce high temperature to achieve the purpose of welding. Reflow technology is not new in the field of electronics manufacturing. The components on the various boards used in our computers are welded to the circuit board through this process. This device has a heating circuit inside the device, and the air or nitrogen is heated to a high enough temperature to blow to the board that has been attached to the components, so that the solder on both sides of the components is melted and bonded to the motherboard. The advantages of this process are that the temperature is easy to control, oxidation can be avoided during welding, and manufacturing costs are easier to control.

There are several categories of reflow welding: hot plate conduction reflow, infrared reflow, gas phase reflow, hot air reflow, infrared + hot air reflow, hot wire reflow, hot gas reflow, laser reflow, beam reflow, induction reflow, polyinfrared reflow, table reflow, vertical reflow, nitrogen reflow.