As no-one on the Technet has ever seen a copper content this high before
(there are a lot of experienced people out there) - is it worth checking
your analysis by getting a second opinion - maybe something has gone wrong
somewhere?!?!?
We carry out regular analysis but we rarely have a failure and copper
content has never been an issue even on an old roller tinner in our PCB
plant (it obviously sees nothing but bare copper) so it seems as if
something is wrong somewhere!
Neil Atkinson - Quality Manager
Stadium Electronic Controls Division
Stephen House, Brenda Road, Hartlepool TS25 2BQ (UK)
-----Original Message-----
From: Phil Nutting [mailto:[log in to unmask]]
Sent: 15 August 2001 15:18
Subject: Re: Solder analysis results
Wow, The overwhelming solution is to lower the pot
temperature and skim
it off the top. This will have to be a project for an
up-coming weekend
or evening.
I think somebody asked how long it has been since our last
analysis or
did we drop pennies into the pot. The truth is (hanging
head in shame)
we have been running the machine for 5 years and this is the
first
analysis we have performed... to quote Steve Gregory -
Woooo-doggies!
With age we all get smarter and I've just been enlightened.
Thanks to all of you for your responses.
Phil Nutting
-----Original Message-----
From: Lou Hart [mailto:[log in to unmask]]
Sent: Wednesday, August 15, 2001 9:21 AM
To: [log in to unmask]
Subject: Re: [TN] Solder analysis results
Any comment on Steve's stratification theory? A few years
back I had
SPC
charts at a HASL pot at a PC fab, with analysis every two
weeks. Cu
content stayed 0.21% to 0.24% over a period of 1+ years,
even though all
we
were doing was skimming stuff off the top. Lou Hart
-----Original Message-----
From: Stephen R. Gregory [SMTP:[log in to unmask]]
Sent: Tuesday, August 14, 2001 10:04 PM
To: [log in to unmask]
Subject: Re: [TN] Solder analysis results
Dave,
Surely, not ALL 1700-lbs.? Wooo-doggies! I can only imagine
what a task
that
would be!!! I've read some stuff that if you keep the pot
static, and
keep
it
at a stable temperature for a period (what this really is, I
don't
know...there's varying opinions), the metals will seek their
own level
(according to the different opinions, the copper will be
towards the
top),
then you scoop out out the top layer, and replenish what
you've removed
with
fresh bars.
The question that I have though, how did the pot get so out
of balance
with
copper? I've never had a problem with copper content, even
when waving
OSP
boards...tin levels dropping, yes. But not excessive
copper...somebody
throw
some pennies in the pot?
-Steve Gregory-
> RJ Klien Wassink suggests [bible p 169] pouring
contaminated solder at
about
> 190°C through a 20 mesh stainless steel stariner to reduce
copper
content
to
> 0.25%.
>
> Dave Fish
>
<< File: ATT00002.htm >>
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