Is there serious development activity on solder alloys using antimony?
If so, has anyone done an environmental impact assessment yet? NOTE: Such
assessments are required for those that subscribe to the 16 principles
published by the International Chamber of Commerce, known as "The Business
Charter for Sustainable Development". Examples, #5 PRIOR ASSESSMENT - "To
assess environmental impacts before starting a new activity or project ..."
and #6 PRODUCTS and SERVICES - "To develop and provide products or services
that have no undue environmental impact and are saf in their intended use,
that are efficient in their consumption of energy and natural resources, and
that can be recycled, reused, or disposed of safely."
Attendees at the 1999 Int'l LF Forum in Minneapolis, MN heard Edwin Smith's
paper on Environmental Impacts and Toxicity of Lead Free Solders" in which
95 tin, 5 antimony solder was tested using five different leach methods (3
US (TCLP, SPLP and STLC), one European (PrEN) and one Japan (JST-13)).
Conclusions >> "The leaching levels are approximately 10,000 times the
maximum allowable in drinking water. The 95Tin-5Antimony allow studied
leached above the regulatory limit in every physical form and in all leach
methods." (Forms tested were 3/8" spheres and -315,+500 solder paste. Based
on this testing, I dispute the comment below that the toxicity of Sb is
related to the oxide form (unless antimony oxide is water soluble). Smith's
sample preparation alloyed the samples under oxygen free conditions.
So, I ask again, is there serious development activity on solder alloys
using antimony?
Are LF solder alloy developers following the ICC principles for sustainable
development?
Lee Wilmot, Sanmina Corp 603/896-2424
-----Original Message-----
From: <Peer Langeveld> [mailto:[log in to unmask]]
Sent: Monday, October 09, 2000 4:54 AM
To: [log in to unmask]
Subject: Re: [LF] Alloy question
As a member of the IDEALS consortium and experienced with
SnAg3.8Cu0.7Sb0.25, I can say that the melting point is still 217dC and
there is no lower cost than without Sb. The low cycle fatigue is about equal
to that of SnPb, be it that the first signs of fatigue showed up later. See
the proceedings in EGG Berlin and IPC Works 2000.
The toxity of Sb is related to the oxide form, that can be produced while
incinerated at temperatures over 615dC
[log in to unmask]@[log in to unmask] on 2000-10-04 00:04:02
Please respond to [log in to unmask]@SMTP
Sent by: [log in to unmask]
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Subject: [LF] Alloy question
Classification:
What does anyone know about the Sn/Ag/Cu/Sb alloy? From what I read,
compared to Sn/Ag/Cu, it has a lower melting point, lower cost, and yet
very similar physical properties. I know there is a toxicity concern,
but, once again, according to what I read, a level of .5% is allowable.
Perhaps it will be phased out eventually much like lead is now. Any
experiences or thoughts on this?
Thanks in advance for your help,
Kirk
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