SURFACE FINISHES COMPARED
Hard gold or EPIG: which PCB surface finish?
The catalogue publishes the same cost, flatness and shelf life for hard gold and EPIG; the table below shows where they differ.
- Known risk with hard gold: Cost/selective.
- Known risk with EPIG: Wire bond (EPIG).
Hard gold and EPIG, as published
| Property | Hard gold | EPIG |
|---|---|---|
| Cost, USD per square inch | Variable | 0.12–0.22 |
| Shelf life | 12+ mo | 12+ mo |
| Reflow passes | not published | 5+ |
| Minimum pitch, mm | not published | 0.3 |
| RF performance | not published | Excellent |
| Gold wire bonding | No (soft only) | EPAG only |
| Aluminium wire bonding | No | Limited |
| Standard | MIL-G-45204 | Under dev. |
| Known risk | Cost/selective | Wire bond (EPIG) |
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.