[time-nuts] HP 5370B low frequency modulation
johnday at wordsnimages.com
Thu Aug 30 11:44:48 EDT 2007
There is also at least one US patent deals with using pure tin
instead of gold for solderability. The problems are also well known
to anyone working with flip-chip bonding where gold bumps have been
used. Both tin and gold have been known to grow crystalline whiskers,
one microscopy journal carried a paper a couple of years ago from
Sandia Lab on the subject. Tin whiskering has been well known for many years.
At 11:21 AM 8/30/2007, Richard (Rick) Karlquist wrote:
>); SAEximRunCond expanded to false
>Errors-To: time-nuts-bounces+johnday=wordsnimages.com at febo.com RETRY
>Gold mixes with solder to from an "intermetallic" that
>suffers from "embrittlement". I am not aware of silver
>solder being a remedy. I have heard of assembly lines
>that do not allow any gold whatsoever in the building!
>I heard our assembly line manager at work just
>last week lecturing yet another engineer about NO GOLD.
>Furthermore, gold plated brass connectors screwed into
>aluminum (with corrosion treatment) (no soldering) will
>corrode in a salt spray environment. I guarantee it.
>We always used stainless for military work.
>Brooke Clarke wrote:
> > Hi Didier:
> > Would you elaborate on the comment "Gold plated connectors are a well
> > known example." Do you mean when soldered with Lead Tin solder instead
> > of a silver bearing solder or something else?
> > Have Fun,
> > Brooke Clarke
> > http://www.PRC68.com
> > http://www.precisionclock.com
> > Didier Juges wrote:
> >> ); SAEximRunCond expanded to false
> >> Errors-To:
> >> time-nuts-bounces+brooke=pacific.net+brooke=pacific.net at febo.com
> >> I have seen cold solder joints on thermal fuses and certain types of
> >> capacitors, while the rest of the instrument was fine with no sign of
> >> corrosion.
> >> I think it has to do with the metal used for certain component leads.
> >> Either
> >> they were never soldered well, or interface corrosion developed over
> >> time.
> >> Gold plated connectors are a well known example.
> >> Didier KO4BB
> >> -----Original Message-----
> >> From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
> >> Behalf Of Mike Feher
> >> Sent: Sunday, July 22, 2007 9:58 PM
> >> To: 'Discussion of precise time and frequency measurement'
> >> Subject: Re: [time-nuts] HP 5370B low frequency modulation
> >> Highly unlikely, but, possible, especially if it was in a corrosive
> >> atmosphere. Of course then I would expect to see evidence of corrosion on
> >> other components. ...
> >> Mike B. Feher, N4FS
> >> 89 Arnold Blvd.
> >> Howell, NJ, 07731
> >> 732-886-5960
> >> _______________________________________________
> >> time-nuts mailing list -- time-nuts at febo.com
> >> To unsubscribe, go to
> >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> >> and follow the instructions there.
> > _______________________________________________
> > time-nuts mailing list -- time-nuts at febo.com
> > To unsubscribe, go to
> > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> > and follow the instructions there.
>time-nuts mailing list -- time-nuts at febo.com
>To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>and follow the instructions there.
More information about the time-nuts