The capability extract shows in thirty seconds what runs as standard and what carries a surcharge.
See capabilities →Send the files and an engineer reviews them against your build — free, before you enquire.
To the data check →Bare copper oxidises within hours, so every board leaves the plant with something on top of it. Which something depends on three things: the finest pitch on the board, how many times it will be soldered, and how long it will sit on a shelf first.
ENIG — electroless nickel, immersion gold — is the default for anything fine-pitch. The gold is thin and dissolves into the solder; the nickel underneath is what actually gets wetted. It is flat, it stores for a year, and it survives multiple reflow cycles, which is why it dominates.
Everything else is a trade. HASL is cheap and robust but leaves an uneven surface that bridges below 0.5 mm pitch. Immersion tin is flat and cheap but has a shorter shelf life and one usable reflow cycle before the intermetallic consumes it. OSP is the cheapest and flattest of all, and the least tolerant of storage and handling. Immersion silver sits between ENIG and tin, with excellent RF behaviour and a sensitivity to sulphur-bearing environments.
Flat, storable, multi-cycle capable. Above roughly 0.5 mm pitch other finishes compete; below it, ENIG is effectively the answer.
OSP degrades in months, immersion tin in six, ENIG in twelve. If boards will be stocked, the finish decision is a logistics decision.
Hard gold on edge contacts with ENIG everywhere else is routine. You pay for the expensive finish only where it does work.
| Finish | Flatness | Shelf life | Best for |
|---|---|---|---|
| ENIG | excellent | 12 months | Fine pitch, BGA, multi-cycle assembly |
| ENEPIG | excellent | 12 months | Wire bonding plus soldering on one board |
| Immersion tin | excellent | 6 months | Press-fit connectors, cost-driven fine pitch |
| Immersion silver | excellent | 6 – 9 months | RF performance, cost below ENIG |
| OSP | excellent | 3 – 6 months | High volume, single reflow, immediate assembly |
| HASL lead-free | poor | 12 months | Pitch ≥ 0.5 mm, robust and cheap |
| Hard gold | excellent | unlimited | Edge contacts and wear surfaces only |
| Multiple finishes | — | — | Selective plating on one board is standard |
Guide values for pre-selection. Binding values are confirmed per project against your data.
The points below are what most often comes back as a query after data review. Settling them before layout freeze saves a loop.
The levelling air knife leaves a domed surface with tens of microns of variation. Below 0.5 mm pitch that causes bridging and unreliable placement — no amount of process tuning fixes it.
Immersion tin gives you one good cycle. If the board goes through reflow twice plus rework, it needs ENIG.
A board built now and assembled in eight months should not be OSP. The finish decision has to include how the boards will actually be stocked.
ENIG has a known failure mode when the nickel is over-corroded during gold deposition. We control it by bath chemistry and cross-section audit — but it is the reason ENIG is not simply free.
Typically 15 – 30 % more on the finish line item, depending on surface area. On a fine-pitch board the question does not arise, because HASL is not an option.
No. The gold dissolves into the solder within a second and the joint forms on the nickel underneath. That is why gold thickness in ENIG is measured in hundredths of a micron — more would embrittle the joint.
Yes. Hard gold on edge contacts with ENIG elsewhere is the most common combination. It has to be specified in the drawing so both are tooled.
Immersion silver has the best surface conductivity and the least skin-effect loss. ENIG is worse because nickel is magnetic and lossy at high frequency — above about 10 GHz that becomes measurable.
Send us your data or a rough sketch. We check feasibility, name the cost drivers and answer within one working day.