Theory of reflow oven

- Mar 22, 2018 -

1. Reflow Soldering principle -- Brief Introduction


Reflow soldering is also called reflow soldering again. It relies on the effect of hot air flow on the solder joint, and the colloidal flux is welded to SMD at certain high temperature airflow. The reason is called "reflow soldering" because the gas circulate in the welder and generate high temperature to achieve the purpose of welding. Reflow welding technology is widely used in the field of electronic manufacturing. All the components on the board used in the computer are welded to the circuit board through this process. The advantage of this process is that the temperature is easy to control, and the oxidation can be avoided during the welding process, and the cost of manufacturing is also easier to control.

2. reflow welding principle -- advantages

Reflow welding is a kind of welding technology developed with the appearance of micro electronic products, which is mainly used in the welding of all kinds of surface assembly components. The main advantages are as follows:

1) when the reflow soldering technology is used to weld, it is not necessary to immerse the printed circuit board into the molten solder, but to complete the welding task by the way of local heating, so the welded components are subjected to small thermal shock and will not cause damage to the components due to overheating.

2) because the welding technology only needs to put the solder on the welding site, and the welding is completed locally, thus avoiding the welding defects such as bridging.

3) in reflow soldering technology, solder is used only once, and there is no case of reuse. Therefore, the solder is pure and no impurities, which ensures the quality of solder joints.

3. reflow welding principle

Reflower with microcirculation of the world's leading technology, the whole furnace is divided into several independent areas, due to the small circulation structure of the hot air blown out from the air outlet after a distance will be around the furnace inlet recycling back, and in the process of recycling, and constantly with the other air blown gas interference occurs, the temperature curve of each block on the PCB change constantly, the welding precision is affected. And how many points of the microcirculation hot air system, there are many point recovery technology, so that the temperature uniformity of the furnace is greatly guaranteed. When the plate is heated, it will not produce a similar small circulation because of the long wind and the shadow phenomenon. So the temperature curve of PCB welding is very accurate when it is heated, so it is very suitable for the small component welding of the lead-free space window.