Don,

The lead in the "dumps" issue concerns the dissolution of the lead component
of solder into ground water.

Lead can be removed from drinking water but not inexpensively.

Ingested lead resides in our bodys' tissue as an immoveable toxin with ugly
side-effects in high concentrations, an especially serious consequence for
children.

In North America the EPA (together with such groups as the ITRI, several
technical schools and private companies) have targeted lead, formaldehyde
and other nasties to be removed from the workplace in their "Design For the
Environment" program (aka DFE). The electronics industry requires a 2-step
approach: Lead used in the solder assembly of PCB's, and lead used in the
solder coating of bare PCB's. The Good News is that there's already
off-the-shelf practical solutions.

ASSEMBLY
Alternative solder alloys (bars and pastes) include tin/bismuth and
tin/silver (search Indium, Kester, AlphaMetals as source examples). Many
companies have found these solders work well with minimal processing
adjustments.

BARE PCB's
The leading Hot Air Solder Leveling (aka HASL) alternative is tin/bismuth.
My experiences indicate that, while most HASL systems can be easily
re-profiled for tin/bismuth, virtually all are still running tin/lead. One
reason for this is that PCB fabricators are taking an extra technological
step forward: In addition to an alternative to lead-bearing solders, they're
looking for alternatives to solder - PERIOD. The leading replacements for
HASL are either electroless/immersion depositied metals or organic surface
protectorates (the latter aka "OSP"). These satisfy the lead-free issue
while also satisfying another issue: Planarity. The alternative coatings are
all virtually flat and appeal nicely to those folks who must place flip
chip/C4/BGA and fine-pitch SMT.

As concerns lead removal, I'll stop here.

Cheers!

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]

-----Original Message-----
From: Don E Steffen <[log in to unmask]>
To: [log in to unmask] <[log in to unmask]>
Date: Friday, January 29, 1999 6:12 AM
Subject: [TN] Removal of Lead


>     Greetings Techno;
>
>     I heard from recent discussions with my German counterpart, that in
>     Europe, they are eliminating the Lead in the solder process. This is
>     becasue of environmental impact studies that Lead content for any type
>     of scrap material being in the PCB's to conponents leaves a certain
>     percentage of lead in the "Dumps".
>
>     If anyone can shed any light on this subject I would appreciate it.
>
>
>     Thanks,
>
>     Donn Steffen
>     Senior Quality Engineer
>     VDO Control Systems, Inc
>
>################################################################
>TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c
>################################################################
>To subscribe/unsubscribe, send a message to [log in to unmask] with following
text in the body:
>To subscribe:   SUBSCRIBE TechNet <your full name>
>To unsubscribe:   SIGNOFF TechNet
>################################################################
>Please visit IPC's web site (http://www.ipc.org) "On-Line Services" section
for additional information.
>For technical support contact Hugo Scaramuzza at [log in to unmask] or
847-509-9700 ext.312
>################################################################
>
>

################################################################
TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c
################################################################
To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body:
To subscribe:   SUBSCRIBE TechNet <your full name>
To unsubscribe:   SIGNOFF TechNet 
################################################################
Please visit IPC's web site (http://www.ipc.org) "On-Line Services" section for additional information.
For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312
################################################################