Brian --

Attitude is not the way to effect change. As a designer I would disreguard
anything stated the bitter nasty self rightous egotistical attitude you
present in this posting. When you find design errors that are equipment
driven you should communicate them back to the designer in a civilized way.
Most designers will work with assembly to produce the highest quality design
possible.

Jeffrey A. McGlaughlin
Sr. PCB Designer
Battelle Memorial Institute
Columbus Ohio
[log in to unmask]

P.S. -- I hsve just personaly gone through a six month search, concluding
with an e-mail conversation with our pick-and-place vendor to get the
minimum rail dimension. Something the operators should have been able to
tell me but seem to have been to busy to answer my questions.


-----Original Message-----
From: Brian Ellis [mailto:[log in to unmask]]
Sent: Saturday, May 13, 2000 9:40 AM
To: [log in to unmask]
Subject: Re: [TN] BGA Design and Pick-&-Place Optics


Mike

How about introducing the notion of concurrent engineering? That way,
everyone from the
design engineer through to the final tester has his say how things should be
made. Just
make it clear to your bosses that, unless something is done to overcome your
problem,
you cannot be held responsible for faulty assembly due a design error that
you have
already pointed out to the designer, and keep the paperwork so that you
cannot be
blamed for having accepted it. Just point out to the designer and your boss
the
financial consequences if a batch is made disoriented due to the designer's
unwillingness to do a bit of paperwork which would probably not cost more
than just one
faulty assembly.

We, at the sharp end of production, must put our foot down firmly when
designers do
stupid things, as they often do. They are not the demi-gods they often think
they are,
able to rule the roost. I have been at both ends and I have seen many
stupidities in my
time.

Brian

Michael Forrester wrote:

> We have designed a custom BGA device with a symmetrical ball design.  The
> substrate is a dark color and one corner of the device
> is cut off to show orientation.  My concern is that the optics in the
> pick-&-place may not pick up the cut corner due to contrast problems.
> In looking at a display of what the camera saw, looking at the part, the
outside
> perimeter of the part was barely visible if at all.  I was using
> a MyData My19 machine.
>
> If the tray holding the parts is loaded incorrectly I feel the machine
will
> incorrectly place the parts.  My suggestion was to add a ball to make
> the design non-symmetrical.  I am getting a strong opposition from R&D to
add
> the extra ball because of the paperwork involved.  We are still
> in prototype stage of the design and want to correct any problems now
before
> production starts.  This part needs to be placed using various
> manufacturers machines.  Are my concerns unfounded or should I be
concerned and
> fight to have the ball added?
>
> Best Regards,
>
> Mike Forrester
> LeCroy Corp
>
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