At the NEPCON West a paper was presented regarding the very issue you 
     are asking about. It is entitled Electroless Palladium Finish For 
     Bonding Fine-Ptich  Devices by George M. Milad & Hugh D. Roberts. If 
     you give me your fax number I will fax you a copy.
     
Jim Spendow MS 127
Smiths Industries
4141 Eastern Ave
Grand Rapids MI. 49518-8727
Ph. 1-616-241-8413
Fax. 1-616-241-8686

______________________________ Reply Separator _________________________________
Subject: Surface Finish
Author:  [log in to unmask] at SMTPpost1
Date:    3/6/96 10:10 AM


     
     The recent TechNet message on the effect of nickel on high frequency 
transmission lines was of interest and we are seeking information on the 
following:
     We have several fabricators suggesting we replace hot air leveling with 
and alternative such as electroless nickel-immersion gold, electroless 
palladium, or just leave the surface bare with an organic surface protector. 
 The boards are Teflon based and dielectric constant can be as high as 10.8. 
 Sounds like nickel is not such a great idea, does anybody have experience 
or data on palladium or just leaving the surface bare on microwave boards? 
 What is the effect of Palladium?  Does the naturally occurring copper oxide 
on the bare board affect performance?
     
Ted Edwards
602-436-3027
[log in to unmask]