John

Another option is flash gold over nickel. Both are plated inline using an electrolytic process(as opposed to ENIG). The gold thickness is roughly two micro inches. The OEMs that I am familiar with that have used this finish have reported very good results. 

Most of the PCB suppliers providing this process are in China.

Best regards

Lee

J. Lee Parker, Ph.D.
JLP Consultants LLC
804 779 3389
----- Original Message ----- 
  From: Babcock John<mailto:[log in to unmask]> 
  To: [log in to unmask]<mailto:[log in to unmask]> 
  Sent: Tuesday, November 15, 2005 7:28 PM
  Subject: [TN] best plated surface finish


  If somebody wants an extra smooth plating finish using lead free plating
  what material would they use...and what would be the finishing process?
  I've heard HASL is sort of rough...and it really doesn't apply using
  silver solder because of the melting temps.
  Is ENIG (electroless nickel immersion gold) the way to go to get a
  smooth finish?
   
  thanks!
   
  John Babcock
  PCB Designer III
  Isothermal Systems Research (ISR)
  2218 N. Molter Rd
  Liberty Lake, WA 99019
  [log in to unmask]<mailto:[log in to unmask]>
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  F: (509) 444-1082
   
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