PCB surface finish compared: HASL, ENIG, OSP and immersion tin
What the finish does, how the common ones differ and how to pick the right one for your assembly.
Why the finish matters
The surface finish protects the bare copper pads from oxidation until the components are soldered. It also decides how flat the pads are, how well the solder wets them and for how long the boards can be stored. The choice depends mostly on the smallest component pitch and on how long the boards wait before assembly.
The finishes compared
| Finish | Surface | Fine-pitch parts | Shelf life | Cost |
|---|---|---|---|---|
| Lead-free HASL | Solder coating, slightly uneven | Suitable for normal pitches | 6–12 months | Low |
| ENIG (nickel and gold) | Very flat | Best choice for fine pitch and BGAs | 12 months | Higher |
| OSP (organic coating) | Flat | Good | under 6 months | Low |
| Immersion tin | Flat | Good | under 6 months | Medium |
The shelf lives apply to vacuum-packed boards in a controlled environment; see the storage and baking guide.
How to choose
- Components with a fine pitch or BGAs need a flat surface: ENIG, OSP or immersion tin.
- Boards that will be stored for months or soldered several times are better served by HASL or ENIG than by OSP.
- Simple boards with through-hole parts and normal pitches are well served by lead-free HASL, the most economical choice.
- If the boards must comply with RoHS, every finish listed here can be made lead-free (see RoHS for PCBs).
What PCB-ELECTRA offers
Our finish is lead-free HASL (see lead-free HASL and RoHS). ENIG is not available at the moment, and neither are OSP or immersion tin. If your design needs one of them, tell us in the request. The limits of our process are in the design rules, and you can price a board in the price calculator.
Frequently asked questions
Is HASL good enough for a normal prototype?
Yes, for boards with ordinary component pitches. It is robust, economical and easy to solder.
When is ENIG worth the extra cost?
For fine-pitch components and BGAs that need a very flat surface, and for boards that wait a long time before assembly.
Which finish does PCB-ELECTRA offer?
Lead-free HASL. ENIG, OSP and immersion tin are not available at the moment.
Browse the questions and answers →
Get the price of your PCB
Upload your Gerber files in the calculator and get an instant estimate in euros.
Open the price calculator →Ask an engineer
Not sure what applies to your board? Describe it in a few lines and our engineers will advise you.