Grant,

seems as you have a thickfilm termination. These are sometimes an issue,
because of contaminations in the surface. Such  can be glass frits or
metal oxides, depending on who's the paste makerk. You want as little
glass as possible in the surface.

Ways to improve the solderability can be the use of stronger flux,
burnishing, plasma cleaning or a light etching. 
First thing I would do is to use a typewriter eraser (hard rubber)and
make some strokes across the terminal, and make  a new soldering.

Inge

 

-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Grant Emandien
Sent: den 2 juli 2008 11:20
To: [log in to unmask]
Subject: [TN] Silver-Palladium termination SMT solder problems

Hi all,
 
We are experiencing poor solderability with AgPd-terminations on MOVs
exposed to a lead-free reflow profile using a SAC alloy on an
ENIG-finished PCB. Though we have run this board only once previously
with the same part finish using a lead-rich alloy, we had similar
effects but not to the extent we are now experiencing.
 
Can anyone provide some insight into this/
 
Regards
Grant
 

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