Surface Finishes

Finish Type Description
Hot Air Solder Leveled (HASL) Solder deposit on features not covered with solder mask. Solder used – 63/37 % eutectic Tin/Lead. Solder thickness 0.2-1.2 mils, variation due to change in board circuit density.
Organic Solderability Preservative (OSP) A transparent organic coating on features not covered with solder mask.
Electroless Nickel Immersion Gold (ENIG) Electroless Nickel and Immersion Gold coating on features not covered with solder mask.
Gold Flash Electrolytic Nickel and Gold deposit on features not covered with solder mask. Typical Nickel thickness 0.15-0.2 mils. Typical gold thickness 0.005-0.010 mils. Gold flash requires Copper plating on pattern.
Immersion Silver (IAg) Immersion Silver deposit on features not covered with solder mask. Typical Silver thickness 0.004-0.020 mils.
White Tin Immersion Tin deposit on features not covered with solder mask. Typical Tin thickness 0.030-0.040 mils.
Carbon Ink — Key Pad Applications Conductive Carbon paste on selective pads for making contact — Remote keypads etc.
Wire Bondable Soft Gold Electrolytic soft Gold plating on features requiring bondable Gold for wire bonding. Typical Gold thickness 0.020-0.050 mils, depending on type of wire bonding used. Typical Nickel thickness between 0.15-0.25 mils.