Stella,

The Pt/Pd/Ag coating is most likely a conventional thick film metallization
which is a combination of glass frits and metal particulates.

With respect to non-wetting - first verify that the components have been
properly stored (dry and away from cardboard).  Are the terminations a dull
stainless steel razor blade color, or are they more black in color?
Anything more dull that the razor blade color may spell problems for you.

I believe the Pt/Pd/Ag's are more prone to wetting issues that the Pd/Ag's,
but the Pd/Ag's are more prone to leaching!!

You might also check to verify that it is indeed non-wetting and not
leaching of the conductor from the surface, yielding a non-wettable
(ceramic) surface beneath.  If leaching was the case (doubtful), you might
try Sn62/Pb36/Ag2.

Steven Creswick - Gentex Corp

-----Original Message-----
From: Stella Neyman [mailto:[log in to unmask]]
Sent: Wednesday, December 05, 2001 6:54 PM
To: [log in to unmask]
Subject: [TN] Platinum/Palladium/Silver plating


Dear technetts, Please help me out.
We are introducing new custom made SMT component: Medium size (approx. 0.5"
x 0.200") with 2 ceramic terminations that plated with Pt/Pd/Ag coating.
Solder paste for our reflow process is 63Sn/37Pb NC low residue. Reflow
profile is standard for this paste reflow peak temp of 220-225 deg C and 50
sec above 183 deg C.
We are experiencing non-wetting conditions on components terminations, some
solder joints cracked during thermocycling testing.
Does anybody experience problem with Pt/Pd/Ag coating over ceramic
substrate?
Any information would be greatly appreciated.
Sincerely
Stella Neyman
Jabil Circuit, MI

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