7.Immersion silver
Immersion silver is difficult between OSP and ENIG. Even when exposed to hot, wet, and pollution, silver can keep good weldability but will lose its luster. The I-Ag does not have the good physical strength of the ENIG, because there is no nickel below the silver layer.
Merits:
Simple process, suitable for lead-free soldering SMT. The surface is very smooth, low cost, suitable for fine lines.
Demerits:
Storage conditions are high and easy to pollute; Problems with welding strength (microcavity); It is easy to show the phenomenon of electrical migration and cavitating in the copper under the resistance welding film.
