-----Original Message-----
    From: Guenter Grossmann <[log in to unmask]>
    To: [log in to unmask] <[log in to unmask]>
    Date: Monday, February 01, 1999 4:54 AM
    Subject: [TN] Lead removal


    Guenter: First I still work on the reliability of tin-lead solder joints
on various pad-surfaces since some tests with isolated boards showed a
somewhat faster growth of cracks in solder joints with pads covered with
alternative surfaces. But never enough data to make a quantitative
statement.
    Bob: Can you share what the alternative surface coating(s) were?
    Guenter: But I can tell you it is damn hard to get any money for this
kind of research. Everybody is whining about the lack of test data and
reliability models. But when it comes to get some money.... Boy, discussing
with the managers who have to say whether or not you may do anything ( e.g.
whether or not you get some money ) can really drive you nuts. One half
tells you that your approach is too academic, the other half says your plans
are not scientific enough. I'm trying the third time now. Urged by process
engineers of our partner companies.
    Bob: I think that's a fair snapshot of most of the Industry on the
subject. There's Pioneers on one end of the distribution curve, Armchair
Experts on the other end, and most of the rest of us somewhere in the
middle.
    Guenter: Wanna know the answer of the project reviewer? Yes? here it
goes: >> There is no commercial nor technical evidence that a project
concerning the reliability of soft solder joints on alternative pad surfaces
other than HAL is justified...
    Bob: There's this company called IBM that might argue otherwise. They
started using Bi-Pb solder in mass production back in the late 60's. Then in
the 70's they started processing that same lead-free solder on OSP-treated
copper lands (Entek Cu-56). Then in the 80's they tested and approved Bi-Pb
on white immersion tin coated copper lands....
    Guenter: ...And anyway, all data necessary are easily found in
literature<<
    Bob: I agree. I find there's far more available from the private sector
than is given credit. I've read comments from several TechNetters that seems
to suggest an attitude that if the information doesn't fall from the pages
of PC Fab or can't be gotten for $30 from the IPC then it either doesn't
exist or doesn't matter.
    Guenter: I have some problems in understanding the whole fuss about the
removal of lead....To make the long story short I must say that everybody is
lamenting about hazardous substances in electronic waste...
    Bob: In the US the issue of lead removal is over-played. The Industry
here isn't focused on lead removal; the industry is really focused on
planarity. We want a flat pad to solder to - period. Lead doesn't scare us,
but uBGA/flip-chip and C4 packaging in-general has certainly got our
attention. "What'll best get me flat?". That's what we're debating.
Gold...silver...OSP...white tin...palladium  -  whichever you pick  -  one
thing is for certain: It won't be a solder alloy. And THAT means it'll be
    lead-free, so that along with the new technology comes an environmental
bonus. And with a variety of lead-free solder pastes and bars already on the
shelves, the change-over won't be anything as dramatic as was the Industry's
move to No-Clean.
    But please don't tell our Dear EPA: Let 'em think we're up all night
just trying to get the lead out.


    Cheers Guenter !
    Bob Lazzara
    Circuit Connect Tech Support
    Georgia Service Bureau
    TEL: 800.560.9457    FAX: 888.453.0520    BBS: 603.889.5385
    alternate eMail: [log in to unmask]

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