Effects of nitrogen on soldering
Being an inert gas, nitrogen reduces oxidation by displacing oxygen, which allows for appropriate spreading behavior at lower temperatures. It also reduces defect formation, owing to imperfections not being introduced in the process, material or surface. It improves flow properties and wettability (bonding between the solder and PCB/component). The use of nitrogen also reduces the quantity and intensity of flux required, which leads to further cost savings. More importantly, it leads to high-quality solder joints that require less heat and flux.
The industry preference for nitrogen use in soldering is heavily influenced by the improved process window, as performing the production process in nitrogen compared to air reduces issues such as defect formation. But the cost benefits are important as well, as the savings offset the nitrogen expenses. Therefore, on-site nitrogen generation in particular makes a better case for cost and resource savings.