[Robotgroup] lead free soldering advice

[Def Egge]

At 01:42  2007-05-24, you wrote:
>The following message is brought to you by Mr. Poo-Poo:
>
>I was talking to an engineer friend who designs circuit boards for a
>living the other day. He gave me some advice about lead free solder -
>don't use it. Apparently the lead keeps crystalline "whisker"
>formations in check. He said the lead free solder starts to corrode
>immediately after use, and in the process forms microscopic
>conductive whiskers that grow over time, eventually shorting with
>other traces. It is for this reason that the US military forbids the
>use of lead free solder. Apparently they don't want equipment failing
>in the field. Neither do I. Although in truth I rarely use my
>equipment these days anyway, much less out in a field.
>
>Bye now,
>Mr. Poo-Poo
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>Robotgroup at puremagic.com
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How rapidly do these tin whiskers grow?

I understand the continued use of lead-based solders in military and 
satellite applications where mission-critical considerations outweigh 
lead-free considerations.  Certainly, the assured recycling of 
electronic components (the mechanism is left as an exercise to the 
reader) would lessen the probability of exposure to lead, cadmium, 
mercury, etc.

Relatively speaking (compared to the MTBF for individual component 
points-of-failure), how likely are these to be the primary cause of 
consumer-grade electronics failures?  Is the expected useful life of 
your iPod, motherboard, HDTV likely to be affected?


All the best....

Mike