Metal finishing Q&As since 1989

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Localized No IG

 

I am curious if anyone reading the finishing.com web site has observed the following no IG deposit: In one of our processes we metallize optical fibers (i.e., ENIG) and have observed on occasions (not routinely) that a few fibers located essentially dead center in the lot of fibers beginning processed to have no gold on the nickel plate. All but a few of the fibers (4 to 6) have plated well and only these few have no gold. We have considered the various mechanical parameters (flow patterns, etc.) as well as the chemical parameters and still do not have a reasonable answer.

Just thought if some one observed the same issue and knew the reason(s) why.

Thank you,

V. F. (Woody) Baston
optronics - Fremont, California, USA

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What is ENIG, electroless nickel, immersion gold?

  
Tom Pullizzi
Falls Township, Pennsylvania
 

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Is it just a bundle, say 1000 or so 250 micron buffer fibers in contact with each other? Sometimes the Immersion Gold reaction can foul due to a potential difference buildup in the center of a bundle if they are all in contact. My follow-up question is: Do you inilize with Evap or Palladium? And is this also done in a bundle? Very interesting process...

Dave Kinghorn
Chemical Engineer
SUNNYvale, California