The right finish protects your copper and your assembly yield.

ENIG deposits electroless nickel (3–6 µm) followed by immersion gold (0.05–0.125 µm). The nickel barrier prevents copper-gold diffusion and provides a flat, solderable base. The gold layer protects nickel from oxidation during storage and soldering. ENIG is the industry default for fine-pitch SMD, BGA, and wire bonding due to its planarity and consistent 12+ month shelf life. One known failure mode is "black pad" — nickel corrosion at the gold/nickel interface — typically caused by phosphorus content in the nickel bath; well-controlled plating eliminates this risk.

EPIG replaces ENIG's nickel layer with electroless palladium (0.08–0.15 µm) followed by a thin gold flash. Eliminating nickel removes the "black pad" failure risk, eliminates nickel's mild magnetism, and removes concerns about nickel contamination in wire bonding. Palladium provides superior hardness for semiconductor chip-to-board bonding. The total finish is thinner and lighter than ENIG. EPIG is the preferred choice wherever nickel is a concern — magnetically sensitive assemblies, medical implants, and demanding wire bonding applications.

ISIG applies immersion silver first, then immersion gold on top. Like EPIG, it is nickel-free and non-magnetic — ideal for GPS, RF, and medical applications where nickel interference is unacceptable. The silver base delivers exceptional electrical conductivity while the gold topcoat provides protection against silver tarnish and corrosion. ISIG supports wave, reflow, and manual soldering processes, and boards are easily reworkable without compromising PCB integrity. A versatile, nickel-free alternative for high-performance designs.

Immersion silver deposits a thin uniform silver layer directly onto bare copper via chemical displacement. Silver is the most electrically conductive of all metals, making this finish exceptional for high-frequency applications where surface conductivity affects signal loss. The finish is flat, RoHS compliant, and significantly more cost-effective than ENIG or EPIG. Critical handling note: silver reacts with atmospheric sulfur compounds and moisture, causing tarnish. Boards must remain in sealed anti-tarnish packaging until SMT assembly begins, and handling with bare hands should be avoided.

Hot Air Leveling (HAL) dips the PCB into molten lead-free solder (99.99% tin, 0.01% copper) then uses hot air knives to remove excess and level the surface. ROHS HAL replaces traditional leaded HASL and complies with the EU RoHS directive. It is the most cost-effective finish with excellent reworkability — components can be easily replaced or repaired multiple times. Surface topography is slightly uneven compared to immersion finishes (solder tends to pool at pad centers), making it less suitable for pitches below 0.5mm. Barrel fill on through-holes is excellent, making it ideal for mixed-technology assemblies.

OSP applies a thin organic compound (azole-based chemistry, 0.2–0.5 µm) directly onto bare copper pads. The organic layer bonds to copper, preventing oxidation without adding any metal layers. OSP produces the flattest, thinnest surface of all PCB finishes — ideal for the most demanding ultra-fine-pitch components — and contains zero metal content, making it uniquely suited for applications where even trace amounts of nickel or silver are problematic. Key consideration: the organic layer partially volatilizes during each reflow pass, degrading with multiple thermal cycles. Boards requiring more than two reflow passes should use a more robust finish. Shelf life after breaking the sealed packaging is limited.