By AK, PCB Engineer
HT Global Circuits

ENIG is Electroless Nickel Immersion Gold ( Au / Ni ), contains two layer metallic coating 2-5 μin gold over 120-240 μin Nickel, as nickel is used as the barrier to the copper and as a surface finish.The gold protects the nickel during storage.

ENIG advantages:

  • Pb free
  • Long shelf time
  • Flat surface
  • Perfect for Plated Through Holes (PTH)
  • Helpful for PCBs with large BGA

ENIG disadvantages:

  • Hard to rework
  • More expensive
  • Black pad