Electroless nickel/immersion gold (ENIG)

Technical Info:

  • Electroless Nickel Immersion Gold  
  • Typ. Au-coat 0.05 – 0.1 µm
  • Typ. Ni-coat 4 – 7 µm  
  • Process temperature ~ 80 °C
  • Max. shelf life 12 months

Advantages:

  • Universally suitable surface finish  
  • No Copper attack during soldering process, Nickel serves as diffusion barrier  
  • Smooth surface  
  • Soldering (with or without lead, mulitple soldering)  
  • Storing between solder processes is possible  

Disadvantages:

  • Relatively expensive  
  • Certain limits for press-fit application  

Application fields:

  • Flex-rigid boards
  • Fine pitch structures and micro vias    
  • Al-wire bonding