Tin Whisker Mitigation
One of the main threats to appear in recent years is Tin Whiskers. Tin whiskers are growths (in many shapes and sizes) coming out of a tin plated termination, mainly attributed to stress in the plating. These growths can extend to adjacent terminations causing shorts. This phenomenon has increased with the move to lead free soldering. The presence of lead in the alloy has been shown to inhibit the formation of tin whiskers.
What are the known reasons for Tin Whiskers to occur?
Various studies have been conducted on this area including one by NASA, exactly how and why tin whisker grows is not completely understood, it was first identified within terrestrial electronics, but these whiskers are known to grow rapidly out of pure tin in the weightlessness, vacuum and temperature extremes of space, some of the other reasons include –
- Stress in the plating
- Micro fractures
- Thin Plating
- Intermetallic compound formation.
- External Stress, Vibrations, Shock
- CTE Mismatch
Retronix’s solution is to convert the pure tin alloy on the termination to one with lead content, using unique processes that meet the stringent standards of even high reliability industries such as defence and avionics:
- Meets ANSI/GEIA-STD-0006
- Fully automated and repeatable
- Can be used for most SMT & thru hole components
- ICOS, XRF & Solderability testing available inhouse for verification