PCBs with ENIG (gold finish): when it pays off and what the alternative is
The standard finish is lead-free HASL. ENIG is the alternative for fine pads and perfectly flat surfaces.
What the ENIG finish is
ENIG stands for "Electroless Nickel Immersion Gold": a layer of electroless nickel covered by a very thin layer of gold deposited by immersion. The finish protects the copper from oxidation until soldering. Unlike HASL, the board is not dipped in molten alloy, so the pad surface stays perfectly flat, which matters for small components.
At PCB-ELECTRA the standard finish is lead-free HASL, RoHS compliant. ENIG is currently unavailable.
ENIG or lead-free HASL
| Criterion | Lead-free HASL | ENIG |
|---|---|---|
| Pad flatness | Slightly domed | Very flat |
| Fine-pitch parts (BGA, QFN) | Possible, with limits | Recommended |
| Several soldering cycles | Good | Good |
| Solderability over time | Very good | Very good |
| Price | Lower | Higher |
| RoHS | Yes | Yes |
Choose lead-free HASL for most projects: ordinary components, prototypes, economical series. Choose ENIG when you have very small or close pads, BGA or QFN parts with fine pitch, or need a perfectly flat surface for automated soldering.
What you should know
- ENIG is not hard gold. The gold layer is thin, suited to soldering, not to connectors with repeated mating (for example contact fingers inserted often).
- The cost is usually higher than HASL because the process has more baths.
- For aluminium boards (IMS) HASL is applied only on the circuit side; see aluminium IMS.
The full comparison, including OSP and immersion tin, is in PCB surface finishes compared. For lead-free HASL and RoHS read lead-free HASL, and for keeping boards storage and baking.
Availability at PCB-ELECTRA
ENIG is currently unavailable. The standard finish, lead-free HASL, is available on every order and is RoHS compliant.
- Upload your files in the price calculator and get the estimate with lead-free HASL.
- If you have very small pads, follow the design rules and the DFM checklist so the board solders well with HASL too.
- For special requirements contact us: we will tell you what is possible.
For sizes, thicknesses and the other options see the capabilities and the options and specifications.
Frequently asked questions
What does ENIG mean on a PCB?
Electroless nickel with a thin layer of gold deposited by immersion. It protects the copper and leaves the pads perfectly flat, suited to fine-pitch parts.
Do you offer ENIG or only lead-free HASL?
ENIG is currently unavailable. The standard finish is lead-free HASL, RoHS compliant.
Is ENIG suitable for connectors with repeated mating?
No. The gold layer is thin and suited to soldering, not to contacts that are inserted and removed often.
Browse the questions and answers →
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