So far as I recall for silver migration to occur, basically you need
A piece of silver
Another piece of separate conductor
a contiguous surface between the silver and other piece of metal across
which the migration will go
a potential difference between the silver and other piece of metal
a little damp
time
[I think you might need some physical strain as well, but I could be
confusing this with the similar problem of tin whiskers]
If you have all of the above then you might get Ag migration, however silver
migration is not a problem with silver adhesives the way they are usually
employed because each particle of silver is encapsulated in the body of the
polymer. What exactly do you mean by "we have had some problems..."
Mike Fenner
Indium Corporation of Europe
T: + 44 1908 580 400
F: + 44 1908 580 411
M: + 44 7810 526 317
W: www.indium.com
-----Original Message-----
From: TechNet [mailto:[log in to unmask]]On Behalf Of Andrew Hoggan
Sent: Tuesday, July 10, 2001 3:13 PM
To: [log in to unmask]
Subject: Re: [TN] Silver Migration
By silver glue I guess you might be referring to a silver loaded adhesive or
ink whereby the silver is encapsulated in an epoxy or PVC or polyester or a
even phenolic system. For there to be migration there would have to be
dissolution in one form or another of the silver, generally it would have to
be exposed to moisture for this to happen, hence the encapsulation by a
silicone would prevent moisture ingression and reduce the risk of migration.
I can't say for certain because I don't know the material you're working
with, but if your 'glue' is properly set then I suspect the silver will be
protected sufficiently unless your product is subjected to some form of
extreme condition or use.
Andrew Hoggan
BBA Associates Ltd
www.bba-associates.com
-----Original Message-----
From: TechNet [mailto:[log in to unmask]]On Behalf Of Elias Allan Bareno
Sent: Tuesday, July 10, 2001 02:14
To: [log in to unmask]
Subject: [TN] Silver Migration
Hello Folks,
Could anyone help me explain how does silver migration occurs? We have
had some problems like exposed silver glue meaning not covered totally by
silicon encapsulant. Will this scenario lead to silver migration?
Allan J. Bareno
Process Engineer
Process Engineering Group
Tel Nos. (632)8445139 ext.288
RF Personal Communications &Consumers
(6349)5430001 to 25 ext 288
Philips Semiconductors Philippines Inc.
Fax Nos. ( 6349) 5439368
Philips Avenue, Light Industry and Science Park 1
email: [log in to unmask]
Bo.Diezmo Cabuyao Laguna Philippines 4025
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