Influence of PCB Surface Finishes on Intermetallic Compound Growth

Abstract

This article presents research focused on the intermetallic compound growing under different conditions. The quality of solder joints depends on many factors, one of which is the thickness of the intermetallic layer and its composition. Combination of multiple reflow processes which is common during the production process and thermal aging you can simulate long-term use of the product, which makes it possible to determine the condition of solder joints in the future. The growth of intermetallic layers using thermal aging is known, but the demand for lead-free solder causes new alloys with unknown properties. Each element in the solder alloy has a different impact on the resulting solder properties. The formation of intermetallic layers also depends on the surface finishes of the pads, so the object of the experiment is to compare the effect of known and used SAC305 solder with solder doped by Ge or Co at the various finishes of pads.