[tinwhiskers] Re: - Impact of elements added to solders
- From: "Patrick Bruneel" <patrick@xxxxxxxxxxxxxxxx>
- To: <tinwhiskers@xxxxxxxxxxxxx>
- Date: Fri, 20 Feb 2009 14:01:19 -0600
Dennis,
Yes it's that hot, it was presented yesterday at the California DTSC RoHS
conference by a researcher from UC Davis.
Michael Kirschner posted this today on the IPC lead free forum.
I don't think it will be an ongoing research. The study is just to prove
that the removal of lead by other alloys is not better for the environment.
Just like the reports from US EPA and university of Stuttgart but the Euro
politicians didn't look at them. Their consultation had 0% scientific
supporting evidence
The reason why I didn't wanted to further comment is that that whole RoHS
and lead free is so ridiculous that I don't even know where to start.
It's a time bomb that will have serious consequences.
I did all the studies in the late 80's to find a better more reliable alloy
(for ruggedized military avionic applications) and found that when you go
lower then 30% lead in a SJ you run in all kinds of problems.
Unfortunately all studies where classified.
Tin is a very aggressive and brittle metal except when mixed with lead.
I also found that the higher you go in tin content the easier it is to grow
dendrites.
The higher the tin content the less ionics required to get dendrite growth
to the point at 100% tin the carbon dioxide and humidity in the air is
enough to grow them.
Another serious problem I see (and nobody talks about it) is galvanic
corrosion due to all the different metals used in lead free.
Before lead-free we had three copper, tin and lead
Now we have copper, tin, silver, nickel, gold, bismuth and all other exotic
additives.
I think all the soft soldering experts left Europe for the USA, because it's
not going to happen over here.
Enough for one day I can keep on going (bad for my ulcers).
Patrick
_____
From: tinwhiskers-bounce@xxxxxxxxxxxxx
[mailto:tinwhiskers-bounce@xxxxxxxxxxxxx] On Behalf Of Fritz, Dennis D.
Sent: Friday, February 20, 2009 12:48 PM
To: tinwhiskers@xxxxxxxxxxxxx
Subject: [tinwhiskers] Re: - Impact of elements added to solders
VERY interesting for my interests. Had not seen this - the date on my copy
is yesterday - is this really that "hot off the press"? Do you know if Cal
Davis has an ongoing study on this methodology?
You posted without comments - you dare to go out on a limb?
_____
From: tinwhiskers-bounce@xxxxxxxxxxxxx on behalf of Patrick Bruneel
Sent: Fri 2/20/2009 12:46 PM
To: tinwhiskers@xxxxxxxxxxxxx
Subject: [tinwhiskers] Re: - Impact of elements added to solders
Here's a study from Julie M. Schoenung
http://www.dtsc.ca.gov/HazardousWaste/upload/Schoenung_LCA_green_electronics
.pdf
No further comments :-)
_____
From: tinwhiskers-bounce@xxxxxxxxxxxxx
[mailto:tinwhiskers-bounce@xxxxxxxxxxxxx] On Behalf Of Fritz, Dennis D.
Sent: Friday, February 20, 2009 8:27 AM
To: tinwhiskers@xxxxxxxxxxxxx
Cc: handwerker@xxxxxxxxxx; gary.latta@xxxxxxxx
Subject: [tinwhiskers] Re: - Impact of elements added to solders
Mark,
Does anyone on this forum know of current scientific work ongoing concerning
the "total environmental impacts of solder substitutes"? I pulled up the
methodolgy of the Stuttgart study, and am chasing down the author of the
2003-2005 US EPA funded study at the University of Tennessee. Seems to me
with one of the focus areas of the proposed "Manhattan Project" to solve the
lead-free dilema for the US Dept of Defense, that we are being very short
sighted to choose an alloy based only on metallurgical properties. You are
correct in assessing the trace addtives (let alone the impurities) in the
new lead-free solders. After tin, silver, and copper, various suppliers are
intentionally adding nickel, antimony, bismuth, zinc, germanium, indium,
manganese, cerium, yttrium, titanium.
How can we as scientists accept adding these to solder without considering
the total environmental impact of the mining, smelting, operator exposure,
and recovery operations of all these elements?
Who has data? Who is willing to help take/compile data? So far, I have
considered this a personal agenda, but am looking for a group of "concerned
scientists/engineers/environmentalists" to gather data to keep some sanity
in these deliberatoins.
Denny Fritz
SAIC, Inc - Subcontract to Crane Naval Depot.
_____
From: tinwhiskers-bounce@xxxxxxxxxxxxx on behalf of Mark Vaughan
Sent: Fri 2/20/2009 3:19 AM
To: tinwhiskers@xxxxxxxxxxxxx
Subject: [tinwhiskers] Re: - RoHS & BGAs!!!
The EU banned our lead in solder after people mainly children in countries
like Africa, and India were being poisoned using fires to extract the lead
from scrap electronics. At least the big publicity stunt to gain public
support in favour of lead free was to film these children.
I wonder how antimony is going to effect this. As far as I recall if you
over heat it you get Stibium oxide which is another nasty poison.
Not sure though whether it will form if an alloy is over heated.
Just wait for it to be on the next ban list.
Regs Mark
Dr. Mark Vaughan Ph'D., B.Eng. M0VAU
Managing Director
Vaughan Industries Ltd., reg in UK no 2561068
Water Care Technology Ltd, reg in UK no 4129351
Addr Unit3, Sydney House, Blackwater, Truro, Cornwall, TR4 8HH UK.
Phone/Fax 44 (0) 1872 561288
RSGB DRM111 (Cornwall)
-----Original Message-----
From: tinwhiskers-bounce@xxxxxxxxxxxxx
[mailto:tinwhiskers-bounce@xxxxxxxxxxxxx] On Behalf Of Parnagian, Edward
Sent: 19 February 2009 23:20
To: tinwhiskers@xxxxxxxxxxxxx
Subject: [tinwhiskers] Re: - RoHS & BGAs!!!
Thank you, Stephan!
Quite frankly, I've been so concerned about whiskers, brittleness and
cleanliness issues that tin plague has fallen below my radar. I really was
unaware of the effects of antimony on tin plague.
Best regards,
Ed
-----Original Message-----
From: tinwhiskers-bounce@xxxxxxxxxxxxx
[mailto:tinwhiskers-bounce@xxxxxxxxxxxxx] On Behalf Of Meschter, Stephan J
(US SSA)
Sent: 2009 Feb 19 8:45 AM
To: tinwhiskers@xxxxxxxxxxxxx
Subject: [tinwhiskers] Re: - RoHS & BGAs!!!
If you are setting up equipment in Alaska subject to prolonged periods
of continuous cold, you may want to consider the Lead-free AIM Castin
alloy since it contains antimony, known to prevent tin pest. There has
been some work showing that the impurities in current Lead-free solder
are enough to suppress pest for most normal applications, however, each
situation should be considered individually (D. Hillman SMTA 2007 and
2008).
If you haven't already looked at them, you may also find info in the
GEIA-STD-0005-1, GEIA-STD-0005-2, GEIA-STD-0005-3, GEIA-HB-0005-1,
GEIA-HB-0005-2, and GEIA-HB-0005-3 useful. In addition to reliability,
they capture many other aspects of lead-free such as program management,
rework and repair, configuration management, supplier flow down,
logistics, etc. They are a rapidly evolving document set, because
lead-free information is changing so quickly. But they are our
documents, to use and to shape as we see fit.
Good luck,
Stephan Meschter
(older files in the thread deleted)
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