SURFACE FINISHES COMPARED
Immersion tin or immersion silver: which PCB surface finish?
The catalogue publishes the same cost, flatness and shelf life for immersion tin and immersion silver; the table below shows where they differ.
- Known risk with immersion tin: Whiskers/IMC.
- Known risk with immersion silver: Tarnish.
Immersion tin and immersion silver, as published
| Property | Immersion tin | Immersion silver |
|---|---|---|
| Cost, USD per square inch | 0.08–0.12 | 0.08–0.12 |
| Shelf life | 6–12 mo | 6–12 mo |
| Reflow passes | 3–4 | 3–4 |
| Minimum pitch, mm | 0.5 | 0.5 |
| RF performance | Good | Excellent |
| Gold wire bonding | No | No |
| Aluminium wire bonding | No | No |
| Standard | IPC-4554 | IPC-4553A |
| Known risk | Whiskers/IMC | Tarnish |
How this was counted
Both columns come from the surface finish table in the MPBxChange material catalogue, as its sources published them. Costs are indicative ranges in US dollars per square inch, not quotations, and move with the gold price and the fabricator. "Not published" means the source gave no value, not that the answer is no.