Four questions
- What is the finest pitch? Below about 0.5 mm, flatness matters and ENIG pulls ahead.
- How many reflow cycles? Double-sided assembly and rework favour ENIG over OSP.
- How long is the shelf life? OSP and immersion silver age; ENIG and HASL keep far longer.
- What does the product do? High-frequency and low-loss designs may need a specific finish to avoid loss in the pad area.
What each finish costs you elsewhere
- HASL — cheapest, tolerates rework, but uneven at fine pitch.
- ENIG — flat and durable, higher cost, and the nickel layer must be controlled to avoid brittle joints.
- OSP — cheapest flat option, single reflow, short shelf life.
- Immersion silver — good solderability, sensitive to handling and tarnish.
Our default
For mixed SMT and through-hole work we quote ENIG unless the design clearly favours another finish. If the assembly plan is unusual — selective solder, press-fit, wire bonding — say so when requesting the quote, because it changes the recommendation.
