I am having a hard time soldering a chip component. This 0603
chip is a multilayer surface mount transient voltage surge suppressor from
Harris (Part Number V5.5MLA0603H). I am suspecting from the termination finish
which it's Silver/Platinum. I already checked the profile and it's OK. I even
tried two different solder pastes (no clean and water wash) and I had the same
result: dewetting and poor soldering, actually the solder paste seems to reflow
without forming a fillet. I taught that maybe the component was contaminated but
I discarded that when I learned we had a similar problem with another product
using a component with similar termination finish (Silver/Platinum). I am really
suspecting that the termination finish is the problem, I would rather have the
nickel/tin finish, but according to the vendor they said they've never seen the
problem we have with another costumer, it seems we are the only ones. Another
thing is that when I made my tests (the two different solder pastes), everything
on the board looked OK except those components. Is there anyone who has had
problems with Silver/Platinum termination finish?, Is this termination plating
more difficult than others?, what are the benefits if we change it to
Nickel/Tin?



               Any advice will be appreciated.

               Thanks

Jorge A. Rodriguez
Conexant Systems, Inc.
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