Reliability

What is the phenomenon called in which needle-like metal crystals grow from the surface of tin plating and short to an adjacent terminal?

  1. AHillock
  2. BVoid
  3. CWhisker
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Answer: C. Whisker

Whiskers are thin needle-like crystals that grow from the surface of tin plating and the like, driven by internal stress and other factors. When they grow long, they touch adjacent terminals and cause shorts. They are suppressed through plating composition, heat treatment and underlayer design. The problem drew renewed attention with the move to lead-free.

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