Hi Jim! We have done a bunch of testing and have found that the immersion
silver finish does not impact the solder joint reliability for a controlled
soldering process. We published the BGA data at the IPC APEX 2000 meeting
in Long Beach (the paper should be listed in the proceedings). We have also
been producing an immersion silver assembly for 10 years for a military
customer with no issues. Nothing solders like solder but immersion silver
isn't too far behind.
Dave Hillman
Rockwell Collins
[log in to unmask]
"Marsico, James"
<James.Marsico@DP To: [log in to unmask]
.AIL.COM> cc:
Sent by: TechNet Subject: Re: [TN] Immersion Silver vs. White Tin
<[log in to unmask]>
08/28/2003 11:59
AM
Please respond to
"TechNet E-Mail
Forum."; Please
respond to
"Marsico, James"
Just out of curiosity, does the immersion silver effect long term
reliability of tin-lead solder joints?
Jim Marsico
Senior Engineer
Production Engineering
EDO Electronics Systems Group
[log in to unmask] <mailto:[log in to unmask]>
631-595-5879
-----Original Message-----
From: Dave Chapman [SMTP:[log in to unmask]]
Sent: Thursday, August 28, 2003 12:53 PM
To: [log in to unmask]
Subject: Re: [TN] Immersion Silver vs. White Tin
Agreed, Immersion Silver was a drop in replacement both at reflow
and wave.
Silver was lower cost or same as HASL. Only caution, the joints do
look
different than HASL boards so education rather than rejection is
the
word of
the day.
As with all alternate finish boards handling is important, hands
off
the
board, slip sheets needed on only the top and bottom boards since
the
finish is actually below the surface of the solder mask so no big
risk of
scratching) in vacuum sealed bags, remove from packaging just
before
processing, don't let sit on the shelf unless fully processed,
don't
wait
3-4 weeks to run through the wave after SMT because you may see
tarnish,
although solderability is still good, statistically the sooner
processed the
better.
White Tin we had to go to higher temp profile and watch every step.
Congratulations on going to Lead Free PCB's
Dave Chapman
-----Original Message-----
From: Bill DeCray [mailto:[log in to unmask]]
Sent: Thursday, August 28, 2003 11:34 AM
To: [log in to unmask]
Subject: Re: [TN] Immersion Silver vs. White Tin
Immersion silver would be the best choice
Highest Regards
William W. DeCray III
Sales Engineering Manager
Waytec Electronics Corp.
Phone: (434) 237-6391 Ext 115
Fax: (434) 237-1324
Cell: (434) 851-6115
E-mail [log in to unmask]
Website www.waytec.com
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Steve Gregory
Sent: Thursday, August 28, 2003 11:31 AM
To: [log in to unmask]
Subject: [TN] Immersion Silver vs. White Tin
Hi All!
Got a customer that's calling out on the fab drawing, either
Immersion
Silver
or White Tin for a board finish.
Me, not having great deal of experience with either one (yet), am
wondering
if I had to choose, which one would I choose?
Have any of you worked with both, and have a preference of one over
the
other? Why?
As always, thanks in advance!
-Steve Gregory-
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