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