Jack Tippit wrote:

We have instances where tin/lead coated pins are inserted into gold plated 
sockets, etc.  Components even have gold/tin-lead or gold/tin interfaces, 
such as an IC socket with a gold contact with a tin sleeve.  Mil-Std-889B 
indicates gold as being incompatable with tin or tin/lead.  Has anyone 
looked into this issue and is there a potential for corrosion formation and 
associated problems?  Again, I just refereing to mechanical contact ( not 
soldering ).

WE HAVE HAD A PROBLEM WHERE A PIN GRID ARRAY PART THAT HAD GOLD LEADS CAME IN 
SOLDER DIPPED AND WHEN INSERTED INTO THE GOLD SOCKET, DEVELOPED FAILURES IN THE	
FIELD THAT OUR FAILURE ANALYSIS CONTRIBUTED TO "FRETTING CORROSION".  WE HAD A 
LARGE QUANTITY OF THESE PGA ASIC'S, SO HAD TO MODIFY THE ASSEMBLY PROCESS TO USE 
THEM UP; NOT EXPOSE TO FLUX, MOISTURE, ADD BAKING STEPS, ETC.  

CINDY KEMP
LOCKHEED MARTIN CORP.
ORLANDO, FL
407-826-6873