OSP serves as an insulating layer between copper and air, making it cost-effective but challenging due to transparency and non-conductivity. Gold plating enhances soldering and prevents corrosion, albeit at higher costs. ENEPIG, with a palladium layer, offers corrosion resistance and versatility. Immersion silver provides simplicity and speed, while immersion tin, though compatible with all solder types, historically faced reliability issues but has been improved with organic additives. Each surface treatment has unique characteristics, but ENEPIG stands out as versatile.