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August 1998

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From:
"Stephen R. Gregory" <[log in to unmask]>
Reply To:
TechNet E-Mail Forum.
Date:
Wed, 26 Aug 1998 18:44:36 EDT
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In a message dated 8/26/98 2:10:54 PM Pacific Daylight Time, [log in to unmask]
writes:

<< Just for fun I'll throw this in... there is an alternative to both epoxy
and solder for electrical connection of IC's to printed circuit boards.  SMT,
CSP, or Flipchip actives are glued pads/connections down onto a PCB.  It
doesn't matter if the glue covers the connection area or not.  Then vias are
laser ablated from the backside of the board to each metal connection pad
(laser stops at higher melting metal).  Electrical connection is made by
sputtering of metal through the holes to the pads in large batch chambers.  No
solder, no epoxy and chip adhesive layer can act as a TCE interposer.

 Down with lead.

 Phil Hersey

 P.S. Europeans have somewhat of a head start on us in experiencing the
effects of pollution in their small highly populated continent.  A Norwegian
customer tells me all the lakes there are dead due to acid rain from
England.>>

Hi Phil,

     Your idea sounds pretty good, so why hasn't it taken off yet? Could it be
that there are other (different) assembly issues besides the one positive
thing something like that would accomplish...eliminating lead? By
accomplishing that, would we be making a REAL difference in the overall
environmental lead contamination anyway?

     What about dense double sided boards? or PTH boards? That stuff ain't
going away anytime soon as far as I can see. Another problem with your idea is
how many companies would be able to afford the "Via Laser Ablator", and the
"Batch Chamber Sputterer" to do that? If that were the only way we could
assemble boards, myself along with about 15 other people that work with me
wouldn't have a job...we're a start-up that's just scraping by. Heck, I'm
getting all giddy because I've been given the okay to go and try to find me a
USED solder fountain to make things easier for us to rework the PTH stuff when
we need to...I know we wouldn't have been able to open the doors if we had to
buy lasers, sputterers, and what have you...

     Yes, the Europeans do have a head start on us, and the way I look at it,
lucky for us they did. They're the perfect example of how NOT to do things.
Back when the Berlin Wall came down, there were a lot of people in the world
happy that finally would be the end of the wall. Besides keeping people in, it
hid decades of horrible chemical dumping, evidence that the east german
government had absolutely no concern whatsoever what they were doing to the
environment...they sat and allowed it to happen. Love canal used to be the
scariest thing I could think of when it came to pollution, but no more...I
wouldn't step foot in east germany without a hazmat suit on.

     So the point I'm trying to make, is that  I've, we've, SEEN what happens
elsewhere, I'll be damned if I allow that to happen in OUR country. Every
place I've worked, and everybody I've met in this industry since I got out of
the Navy in 1987 has the awareness concerning lead in the environment. There's
been a usage log of bar solder, solder paste, and dross re-cycling logs, at
every employer I've worked for, we account for what we use. Here in the S.F.
Bay Area  just like many other places in the country you've got to have your
hazardous waste permit to operate...we're taking a LOT of care to make sure we
put the lead on only boards. So this still leads me back to the question; Why
are we being forced to look for lead alternatives?

      If, and when, the banning of lead happens...I think there's a few people
or organization that are gonna get real rich...and that's the only reason I
feel it's being pushed so much. I could be totally wrong about this, but how
else can you explain it when you see the facts?


-Steve Gregory-

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