The Influence of Nitrogen Atmosphere on Properties and Development of IMCs in Selected Lead-Free Solders

Abstract

This study investigates the impact of different atmospheric conditions and plasma treatment on the wetting properties and intermetallic compound (IMC) thickness in lead-free soldering processes. Lead-free solders, primarily composed of high tin content, exhibit different wetting characteristics compared to traditional lead-based solders, influencing the quality and durability of solder joints. The use of an inert nitrogen atmosphere during soldering significantly improved wetting quality, reducing oxidation and enhancing solder flow. Plasma treatment further increased the wetted surface area by an average of 10%. The analysis also highlighted that thermal profiles had a more substantial effect on wetting quality and IMC properties than atmospheric conditions. Under nitrogen, IMC thickness remained stable across thermal profiles, while vacuum conditions showed increased IMC thickness and variability with high profile settings. These findings suggest that optimizing atmospheric conditions and thermal profiles is crucial for improving solder joint reliability in lead-free soldering, with plasma treatment showing potential as an additional enhancement technique. Future research will explore varying plasma treatment settings to further optimize solder joint quality.