Hi Henry! Wow, nickel plating is commonly used as a barrier layer in a 
number of electronics applications so having an erosion issue would be 
somewhat odd. I would expect that a lead-free soldering process would 
remove more nickel (either thru erosion or dissolution) in comparison to a 
tin/lead soldering process due to the increased process temperatures but 
what you are describing (large?) sounds strange. Have you compared the 
nickel thickness pre and post soldering process? Do you have any 
microsection photos Steve could post so we could get a look at the 
situation? I have run a significant number of ENIG pwbs thru both 
lead-free wave and reflow processes but have not seen the condition you 
describe. Are you on a mini-wave, selective solder or typical wave solder 
system?

Dave Hillman
Rockwell Collins
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henry rekers <[log in to unmask]> 
Sent by: TechNet <[log in to unmask]>
11/26/2008 06:17 PM
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Subject
[TN] nickel erosion






Any technetters out there experiencing this mysterious nickel erosion 
process with enig boards on their leadfree waves?  Apparently there is a 
committee set up already.  I would like to share experiences if anyone is 
willing to come forward.
 
Essentially, the defect shows up as a dewet on the annular ring of the TH 
devices.  On cross section, there is large amounts of nickel eroded away 
and the surface is non-wettable.  No corrosion is evident, so it's NOT 
black pad.
 
Anybody?


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