The paper kinda, sorta, gets around to mentioning silver
migration at the very end. The is a very important failure
mechanism for silver plated traces that have a DC voltage
difference between them. The paper mentions that this occurs under
specific conditions, but does not say what those conditions are.
The conditions are easily met. A small potential difference
between the conductors, and moisture. A film of water is not
necessary, but just plain humidity. If you want to see this very
dramatically, and quickly, put 5 volts between two silver plated
conductors and bridge them with a drop of water. Watch under about
10X magnification. A fern like (dendritic) structure will grow out
from the negative side toward the positive trace. If you don't
limit the current, the the dendritic structure will "explode" when
it hits the positive trace. If you limit the current enough, the
short will be permanent, even after the water evaporates.
A good description is available here:
This is a well known failure mechanism in the aerospace community.
Harvey
I posted a file RE silver vs gold plating for contacts. I probably shouldn't take up file space for this so i will delete the file and just supply the link.
The Performance Implications of Silver as a Contact ... - TE Connectivity
Mike N.