Subj: Re: [TN] Soldering Palladium plated leads
Date: 10/2/98 9:16:56 AM Pacific Daylight Time
From: SteveZeva
To: [log in to unmask], [log in to unmask]
In a message dated 10/2/98 8:54:32 AM Pacific Daylight Time,
[log in to unmask] writes:
<< Hi,
With all the current discussion of solderability issues, I'm hoping some of
you may be able to apply your expertise and give me some insight into a
problem we seem to consistently have. When soldering components with
palladium plated leads, we do not seem to get any wetting on the leads. It
kind of looks like the 'footprint in mud' affect. On pcb's where we have
this condition, all other components have soldered fine with good fillets
and wetting. Checks of the oven profile indicate a good profile for the
paste we're using (Kester R598, water soluble). Currently we've only found
this on components from TI, so I don't know if it's only their components or
the plating in general.
Question: Are there any recommendations for profile, paste, process, etc.
that differ from 'standards' when working with these types of components?
Thanks.
Rick Thompson
Ventura Electronics Assembly
2665A Park Center Dr.
Simi Valley, CA 93065
[log in to unmask]
(805) 584-9858 voice
(805) 584-1529 fax
################################################################ >>
Hi Rick!
There's been a lot of discussion in the past about palladium plated
leads, and what you observe with the way the solder behaves during reflow is
correct. The solder doesn't flow quite as readily as it does with a tin/lead
plated lead, you know the ol' saying; "nothing solders to solder like
solder..." . With palladium plated leads it helps to peak a little higher than
you normally would, maybe 10-15 degrees higher.
Your observation about seeing only T.I. parts is correct too. I know
they were the first ones to convert over to palladium plating, I don't know
who all is doing it now. T.I. did it to eliminate lead in their processes and
to improve yeilds. If you are able to browse the 'NET, go to: www.TI.com and
on the opening page type palladium in the search box. It'll take you to at
least a half dozen articles on palladium plating. If you can't, email me back
and I'll go and fetch the articles and send em' to ya' in a email attachment.
-Steve Gregory-
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