[tinwhiskers] Re: - Impact of elements added to solders

  • From: "Fritz, Dennis D." <DENNIS.D.FRITZ@xxxxxxxx>
  • To: <tinwhiskers@xxxxxxxxxxxxx>
  • Date: Fri, 20 Feb 2009 09:27:09 -0500

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


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