Nice to have you back on line Guenter, I think this is your first
     contribution since your return.
     As a metallurgist, can you tell us what are the alternatives and their
     M.P.s.
     If we use ternary (spelling?) instead of binary alloys, what
     complications will there be?
     Are the solder suppliers capable providing the whole industry with
     these alternatives?
     Who's been thermal cycling assemblies with these new materials?
     What fluxes will we use? How active will they have to be?

     regards



______________________________ Reply Separator _________________________________
Subject: [TN] Lead removal
Author:  "TechNet E-Mail Forum." <[log in to unmask]>           Guenter Grossmann
<[log in to unmask]> at INTERNET
Date:    01/02/99 10:37


<fontfamily><param>Times</param><bigger><bigger>Hi all


Seems to be a hot issue. As a matter of chance I am involved in both
aspects here. And I face the same problems in both aspects here.

First  I still work on the reliability of tin-lead solder joints on
various pad-surfaces since some tests with isolated boards showed a
somewhat faster growth of cracks in solder joints with pads covered
with alternative surfaces. But never enough data to make a quantitative
statement. But I can tell you it is damn hard to get any money for this
kind of research. Everybody is whining about the lack of test data and
reliability models. But when it comes to get some money.... Boy,
discussing with the managers who have to say whether or not you may do
anything ( e.g. whether or not you get some money ) can really drive
you nuts. One half tells you that your approach is too academic, the
other half says your plans are not scientific enough. I'm trying the
third time now. Urged by process engineers of our partner companies.
Wanna know the answer of the project reviewer? Yes? here it goes:

>> There is no commercial nor technical evidence that a project
concerning the reliability of soft solder joints on alternative pad
surfaces other than HAL is justified. And anyway, all data necessary
are easily found in literature<<<<

OK, so much for reliability of solder. The other area I'm working in is
recycling of electronic waste. Lots of people know, that compared to
what nasties you find on a assembled PCB's, lead  one of those that make
us the least trouble.  If one is looking at the technologies necessary
to extract these substances it becomes clear that the extraction of lead
is a piece of cake. Because of that, there are hard laws coming up in
Europe concerning the disposal ( forbidden ) and recycling of electronic
waste and there are a lot of European projects concerning the
environmental aspects of electronic waste.   But I can tell you it is
damn hard.......

I have some problems in understanding the whole fuss about the removal
of lead. Anyway electronic waste shouldn't be looked at as waste and
for sure it doesn't belong into a dump. It would be much cleverer to
declare it as raw material. You see, one of the main sources of costs
for recycling of electronic waste is the transport. And just because it
is declared as hazardous waste and must be transported in transport
equipment designed for the transport of hazardous waste. Also because
of the lead in the solder joints. Did someone ever think of the
transport of electronic equipment before it is out of use? And, coming
back to ban lead, did ever someone look at the incredible amounts of
lead coming into our environment by sources other than electronics ( we
just had a case of high lead contents in game meat due to the lead
balls used in hunting. Can you imagine how much lead is deposited
UNCONTROLLED in our countries by means of ammunition? )


To make the long story short I must say that everybody is lamenting
about hazardous substances in electronic waste, lots of people talk
about guesswork when it comes to reliability of solder joints but
nobody is willing to invest 5 cents to get facts.



Gee, I think I got a bad morning today.


Cheers


Guenter


</bigger></bigger></fontfamily>

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