Although the "Tin Whiskers" caused by the elmination of lead in electronics
may sound off topic in the AMPS reflector they are quite relevant as many of
our newer commercial amps contain not only printed circuit boards, but ICs
and other semiconductors that are going to be affected by this change and
particularly the new solid state, does everything amps. We also use
subassemblies and solid state components in our monitoring and control
circuits. We may need to evaluate future projects and purchases at it
appears equipment and parts manufactured to the new Restriction of Hazardous
Substances Directive or RoHS are quite likely to have greatly reduced
reliability where mean time between failures (MTBF) goes from thousands or
hundreds of thousands of hours to a couple of calendar years.
As to the requirement not applying to us in general for building or
repairning our own equipment that is likely to happen by default. If the
sale of solder to manufacturers drops to zip I doubt the home hobbiest, or
ham is going to present enough of a market to assure the availability of
easy to use solder. If it becomes unavailable then we are stuck with the
alternative even though it's not legally required. The same is true for
enclosures. Although we may not use tin plated enclosures for our projects,
what about remote mounted amps, relays, and other *stuff*?
So the new RoHS leaves us pretty much in limbo as far as future components
and reliable parts
73
Roger (K8RI)
> From: sub1@rogerhalstead.com
Roger Wrote:
SNIP lots of material:
> OTOH due to an over reaction we are being forced to remove lead from
> electronics. It's not that lead isn't an environmental pollutant, but it
> is
> necessary (so far) to prevent "tin whiskers" from forming in devices. We
> need to weigh the impact of removing the lead compared to early failure of
> satellites (it's already happened) to medical devices (pacemakers
> recalled).
> It only takes a tiny amount to prevent, or greatly reduce the formation of
> these "tin whiskers" and until we find a suitable replacement not using
> lead
> may pose more of a health threat than using it.
SNIP lots of material re BeO
RE the Tin whiskers, take a look at this:
http://nepp.nasa.gov/whisker/anecdote/2003rf_enclosure/index.html
Professor Todd Weatherford KI8CX, at the Navy School in Monterey is
researchng
consequences of lead free electronics and predicts doom and gloom as to
lifetime of future electronic equipment due to the tin whisker problem,
which also manifests in the metals used in IC wafers. He predicts something
like less than a 2year MTBF on consumer electronics, due to the lead free
aspects.
All the Best, 73,
Pat Barthelow aa6eg@hotmail.com
http://www.jamesburgdish.org
Subscribe: http://bambi.net/jamesburg.html
Jamesburg Earth Station Moon Bounce Team
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