[aprssig] FW: Digi-Key RoHS Compliance Part(s) Bulletin
Mark Fellhauer
sparkfel at qwest.net
Tue May 1 18:34:44 EDT 2007
At 01:23 PM 5/1/2007, Robert Bruninga wrote:
>Can a Lead-free compliant component still be soldered??
Yes, and it usually means that a component can take a higher heat than a
standard non-ROHS (pronounced ROW-HAAS).
There are all sorts of unintended consequences to the removal of lead from
solder with doubtful benefits to the environment.
I'm typing this as I sit about 10 feet from a MyData TP-11UFP, an My-9, and
a couple of ROHS and lead-solder reflow ovens.
A standard lead-soldered PCB will pass an 8 RCRA metals TCLP for landfill,
and is not hazardous waste as defined scientifically. I know this because
I used to profile wastes for landfills. And is metallic silver any less
toxic to the environment than lead? I doubt it.
The adoption of ROHS means that our contract production facility had to add
a new 200 amp service panel to handle the increased amount of electricity
required for the higher heat silver/tin solder reflow ovens. The solder
itself is much more expensive. Tin is becoming a very scarce commodity
and it's price has quadrupled in the last few years. Tin mines are nearly
exhausted world-wide, and it could get ugly in a few years. Not only does
the electronics industry rely on tin, but almost all modern window glass is
float glass, which is made by flowing out molten glass on a pool of molten tin.
The whole purpose of adding lead to solder is to prevent the tin from
"whiskering," a phenomenon first discovered in the 1940's by the telephone
industry. Silver does not prevent whiskering in tin solder. This has
become a big issue in the medical and aerospace industries.
So what do we get from ROHS? Increased electrical use in soldering
operations, increased use of tin, decreased reliabilty in electronic
components, and increased cost in delivered consumer goods.
Meanwhile, our legislators are pushing for an all out ban on incandescent
lights in favor of CFL's. CFL bulbs, among other problems, contain
Mercury. So much Mercury that non of the current products will pass an 8
RCRA metal TCLP for landfill. They do classify as a hazardous
waste. Mercury is far more difficult to encapsulate and deal with than
lead in the wild.
And unfortunately our regional and federal legislators (worldwide) are not
competent to deal with complex issues of technology and insist of
legislating by what feels good and shows the public "they care," rather
than what makes sense.
Mark
KC7BXS
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