Elisabeth and Christian,

If you have any questions about the ENIG process itself
I am sure I can answer some questions for you. I have done 2 installations
using the Uyemura chemistry and we are currently running the ENIG process
for 2+ years.
Feel free to contact me.

Tony Steinke
AIT-Atlanta Inc.
[log in to unmask]
----- Original Message -----
From: "Zweigart, Siegmund" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Tuesday, August 19, 2003 7:04 AM
Subject: [TN] Black Pad Detecting Machine


> > Hi all,
> >
> > we are two students named Elisabeth Stumpf and Christian Wuerfel
studying
> > at Solectron Herrenberg in Germany.
> > In the context of our studies we are currently working on a project to
> > investigate the potential market for
> > a machine which is designed by Solectron. This machine shall detect
Black
> > Pad infected PCBs before being assembled
> > and without destruction of the PCB.
> >
> > The prototype is now under construction. Afterwards function tests will
be
> > made, by which the operativeness of this machine
> > is checked
> >
> > What is Black Pad?
> >
> > Black Pad is described as the corrosion of immersion gold-plated,
> > elctroless nickel ( ENIG).
> >
> > Thereby interconnection failures occur after final assembly of the PCBs
> > due to a poorly formed joint at the solder/nickel interface.
> > When the suspect joint is stressed, the connection is easily broken,
> > leaving an open cicuit.
> > In other cases, the pads are dewetting during the soldering process.The
> > dewetted pads are discolored black, which lead to the
> > nomenclature BLack Pad.
> >
> > Investigations on Black Pad show that a corrosive interlayer between the
> > gold and the nickel causes it. It is an insidious
> > problem, since this interlayer is covered by gold and therefore, it has
> > been not able until now to detect Black Pad by
> > non-destructive methods. The symptoms of Black Pad only occcur after
> > soldering which causes high costs since the PCB
> > and the assembled componenets have to be scrapped.
> >
> >
> > Elisabeth`s and my job is to decide if this machine can be successul.
> > Therefore we need your support.
> > If you are interested in our topic we would like to contact you
personally
> > and ask you some questions.
> > Of course we let you participate in our results.
> >
> > We would be very grateful for your answers!
> > Thanks a lot in advance.
> >
> > Elisabeth and Christian
> >
> >
>
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To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest
Search the archives of previous posts at: http://listserv.ipc.org/archives
Please visit IPC web site http://www.ipc.org/html/forum.htm for additional
information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315
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