Surface Finish

PCB Surface Finish

Surface finish protects exposed copper pads from oxidation and ensures reliable soldering during component assembly.

HASL (Hot Air Solder Leveling)

The most affordable finishing option. The board is dipped in molten tin/lead solder, then excess is removed with hot air. Provides good solderability but may have uneven pad surfaces.

Lead-Free HASL

Same process as HASL but uses lead-free solder alloy. RoHS compliant.

ENIG (Electroless Nickel Immersion Gold)

ENIG provides a flat, uniform surface ideal for fine-pitch components and BGA packages. Benefits include:

• Excellent surface planarity
• Lead-free and RoHS compliant
• Longer shelf life (12+ months)
• Tighter tolerances for fine-pitch components
• Required for gold fingers

OSP (Organic Solderability Preservative)

A thin organic coating that protects copper. Cost-effective and environmentally friendly, but has a shorter shelf life than ENIG.