HASL (Hot Air Solder Leveled)

Solder is deposited on features that are not covered with Solder Mask. Solder Thickness varies 

from 0.2 to 1.2 mils. This variation is due to board circuit density, aspect ratio. Solder consists

of 63%/37%eutectic Tin/lead

OSP (Organic Solderability Preservative)

A transparent organic coating is deposited on features that are not covered with solder mask.

ENIG (Electrolysis Nickel/Gold)

Electrolysis nickel and Electrolysis gold is deposited on features that are not covered with 

Solder Mask.Thickness for Nickel is between 80 to 150 micro inches and Gold thickness 

is 3-6 micro inches.

Gold Flash

Electrolytic nickel-gold deposited on solderable features. Typically 150-200 micro inches of

ickel is deposited, and 5-10 micro inches of Hard gold. Gold flash is applied to features after

pattern Copper plating.

Immersion Silver

Silver is deposited on features not covered with solder mask. Thickness of silver is 4 to 20 

micro inches.

White Tin

Immersion tin is deposited on features not covered with Solder mask. Thickness is typically

30-40 micro inches.

Carbon Ink for Key pad application

A conductive carbon paste is applied on selective pads for contact purposes, e.g. Keypads of

calculators, etc.

Wire Bondable Soft Gold

Electrolytic soft gold is plated on features that require bondable gold for wire bonding application.

Depending on the type of wire bonding used, the thickness of gold varies from 20 to 50 micro

inches. Nickel thickness is between 150 to 250 micro inches.