Due to switch contact wiping, the thin ENIG gold will wear off the PWB
depending on what the life of your product is.  You should run a life test,
do pre/post electricals (make sure you check contact bounce) and pull the
switches apart for examination at the end of the test.  Typical switch
domes ride on 4 corners so have "redundancy" built into them.  After a
typical "1 million" actuation life your domes will be riding on the nickel
since all the gold will be wiped off.

My experience with ENIG PWBs/PWAs is that the gold is not sufficient to
protect the nickel from corroding during a cycled humidity test.  I've seen
gold flake off PWBs due to corrosion cells forming underneath the gold.

Best regards,
Gregg


At 10:21 AM 6/17/02, Rick Fudalewski wrote:
>Bev
>
>reason why i was asking about the elni/au - customer had recommended to
>their OEM customer - but was informed that the immersion gold did not
>stand up to humidity testing - is there something that went wrong?
>
>Rich F
>
>FCT