Yeah, you're right Dave. I took it upon myself and renamed Pat's pictures to
a shorter name to whisker1, whisker2, etc. just to shorten them and try to
keep the links from word wrapping which screws the link up. My fault...
From the looks of it, they are crystalline corrosion by-products, NOT
whiskers!
Steve
-----Original Message-----
From: David D. Hillman
Sent: Thursday, March 08, 2012 6:07 PM
To: [log in to unmask]
Subject: Re: [TN] Black substance
Hi Steve - just a comment (great pictures). The fuzzy substance is a
crystalline structure that is most likely a corrosion reaction root cause
and is probably not a "whisker" - at least in the sense of what the
industry defines as a tin whisker. I know if seems like a silly point but
I am just trying to head off a future conversation with someone who saw
Pat's "whisker" pictures and got the wrong idea without finding out all
the facts. Sure would love to have a SEM EDX analysis of the substance to
get a chemical identification.
Dave
Steve Gregory <[log in to unmask]>
Sent by: TechNet <[log in to unmask]>
03/08/2012 04:33 PM
Please respond to
TechNet E-Mail Forum <[log in to unmask]>; Please respond to
Steve Gregory <[log in to unmask]>
To
<[log in to unmask]>
cc
Subject
Re: [TN] Black substance
Hi Pat,
Got your pictures and have them posted. Sorry for the delay, but I'm still
running in low gear. Here they are, and all I can say is YIKES!
http://stevezeva.homestead.com/whisker1.JPG
http://stevezeva.homestead.com/whisker2.JPG
http://stevezeva.homestead.com/whisker3.JPG
http://stevezeva.homestead.com/whisker4.JPG
http://stevezeva.homestead.com/whisker5.JPG
These look like the classic silver/copper corrosion from being exposed to
reduced sulfur gasses such as hydrogen sulfide. Here's a good paper that
details it all:
http://chavant.net/new_site/files/pdf/HP_ImAg_Corrosion_Paper_ISTFA_20061.pdf
I would be very scared, very, very scared...
Steve
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Steve Gregory
Sent: Thursday, March 08, 2012 11:25 AM
To: [log in to unmask]
Subject: Re: [TN] Black substance
Hi Pat,
Reply to me with the pictures and I'll get them posted...
Steve
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Goodyear, Patrick
Sent: Thursday, March 08, 2012 1:39 PM
To: [log in to unmask]
Subject: [TN] Black substance
Ok got a new one. Found on the plated portion of a turret a black fuzz,
also on the riveted backside and the plated portions of all of the lands
outside the soldered areas.
It cleans right off with alcohol leaves no residue, is crystalline in
structure and grows away from the metal has a coral like appearance.
I have attached pictures but Steve is off today so don't know who else can
post.
Again a 40 year old board.
Any ideas????
Pat
.
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