"clifto" wrote in message
...
Glen Walpert wrote:
My nutshell summary of the published test results is that lead free is
significantly harder to do right than tin-lead, requiring tighter
process controls, but if done right it can be more reliable than
tin-lead for non-shock situations.

MORE reliable? Please elaborate.

The reason that one might speculate this is that PbF solder has a higher
melting point and is harder, thus perhaps less prone to thermal damaged due
to cycling. This might be the case IF done right, but there are so many
variables that it is impossible to generalize this. The fact is that most
in the field realize that it is much easier to get it right with leaded
solder, and it is generally considered to be more reliable for most
applications. In fact, there are exemptions for critical applications that
allow leaded solder, even in the EU. The biggest problem that I have seen
in consumer electronics with PbF is that not enough solder is deposited in
the automated process of making the boards. This aften leads to an
unreliable joint. It is also harder to get good results in repairs with
PbF, as it requires higher temperatures and even the most freindly
formulations do not wet and flow as well.

Leonard

On Thu, 26 Jul 2007 18:14:20 -0400 in sci.electronics.design, "Leonard
Caillouet" wrote,

The reason that one might speculate this is that PbF solder has a higher
melting point and is harder, thus perhaps less prone to thermal damaged due

Lead Fluoride???

David Harmon wrote:

On Thu, 26 Jul 2007 18:14:20 -0400 in sci.electronics.design, "Leonard
Caillouet" wrote,

The reason that one might speculate this is that PbF solder has a higher
melting point and is harder, thus perhaps less prone to thermal damaged due

Lead Fluoride???

It's for brushing your mercury fillings.

--
"Liberals used to be the ones who argued that sending U.S. troops abroad
was a small price to pay to stop genocide; now they argue that genocide
is a small price to pay to bring U.S. troops home."
-- Jonah Goldberg