Nitrogen reflow soldering is to fill nitrogen in the chamber of reflow soldering furnace. Nitrogen reflow welding is mainly used to enhance the quality of welding, so that welding occurs in an environment with very little oxygen content (100PPM), which can avoid the problem of component oxidation. So the main problem with nitrogen reflow is to keep the oxygen content as low as possible.
Nitrogen-filled reflow welding technology and equipment have improved the quality and yield of reflow welding and become the development direction of reflow welding. Nitrogen reflow welding has the following advantages
(1) prevent and reduce oxidation
(2) improve the wetting force of welding and speed up the wetting speed
(3) Reduce the production of tin ball, avoid the bridge, and get better welding quality
(4) Is particularly important, you can use a lower active flux solder paste, at the same time also can improve the performance of solder joints, reduce discolouration of the base material, but its drawback is obvious cost increases, the increase of cost increases with the amount of nitrogen, when you need furnace reaches 1000 PPM of oxygen, oxygen and 50 PPM general nitrogen content test is composed of form a complete set of on-line oxygen analyzer, oxygen content testing principle is by the oxygen content analyzer connected by nitrogen reflow site, first to collect gas, oxygen is analyzed with the numerical after oxygen analyzer test the content of nitrogen purity range are obtained