Ken:
	    Matt tin is a mitigating factor according to some reports.
Most companies are aware of Tin whiskers. They also anneal the parts for
an hour at 150 deg C for an hour within an hour after they are plated to
release the stress caused by plating. In addition if the boards are
Cced, then the combination of the three reduces the case for whiskers.
For defense of space use. this is not enough. In those cases the need
for replating by dipping all the way to the base of the lead is
necessary. The military would accept one or two parts as described at
the beginning,  potentially problematic real state is small, with their
prior approval.
	Regards,
	Ramon



-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Charles Dennehy
Sent: Thursday, January 25, 2007 8:14 AM
To: [log in to unmask]
Subject: Re: [TN] Lead-Finish Question

Ken,
Below is a link to a nearly finished Office of Naval Research, ManTech
Research Project on Tin Whisker Mitigation if that helps.
Charley Dennehy

http://www.bmpcoe.org/news/bmpnews/tinwhisker_report.pdf



-----Original Message-----
From: TechNet [mailto:[log in to unmask]]On Behalf Of Bloomquist, Ken
Sent: Wednesday, January 24, 2007 1:25 PM
To: [log in to unmask]
Subject: [TN] Lead-Finish Question


Here's a question for all the high rel people out there. We've received
a couple of notifications from major component suppliers that they will
no longer supply the parts we need with a SnPb finish. Instead they are
only supplying them with "Matt (Matte) Tin" finish. They do not talk
about any under plating which would be desirable for minimizing tin
whiskers.

How are you people who build for DOD and medical handling these
situations? Am I being too sensitive about Matt Tim?

By the way these are single source and SMT parts.

Thanks in advance,

KennyB

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