
PCB Surface Finishes - Implication on the SMT Process
ENIG (electrolessnickel/immersion gold) ImAg(immersion silver) ImSn(immersion tin) - Complicated Chemical Process, Clean 6 Chemical Steps; 20 chemical ingredients - Ni Thickness = 50-150 microinches - Au Thickness = 3-10 microinches ENIG picture source: Multek. ENIG: Soldering Two Intermetallics Intermetallic Intermetallic Electroless Ni Immersion Au ENIG PCB Solder Mask Copper
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