Oxygen Concentration Effects on Soldering Quality

This technical report investigates the impact of oxygen concentration in the soldering atmosphere on soldering defects and overall soldering quality. The study focuses on various soldering defects, including solder balls, nonwetting, solder joint bridging, component misalignment, and residues. It outlines the importance of controlled-atmosphere soldering and presents experimental findings that demonstrate how adjusting the oxygen levels in nitrogen can minimize these defects. The report details the methodologies employed, including laboratory investigations and production-scale evaluations, using specific solder pastes and circuit boards. The results indicate that the density of solder balls increases with higher oxygen concentrations, particularly above 10,000 ppm, while the extent of solder spread is adversely affected by oxygen levels exceeding 1,000 ppm. The report concludes with guidelines for selecting the appropriate nitrogen purity level to optimize soldering performance and reduce defects, emphasizing the critical role of inert atmospheres in modern soldering technology.