This email is not a Protel-specific question but instead concerns a
generic problem with some boards I'm getting, so I apologize for being
off-topic, but this forum has more PCB experience than any other I
know of, so I would like to get your advice.
A partner in a manufacturing effort is
In a message dated 2004-07-20 11:46:57 AM Eastern Daylight Time,
[EMAIL PROTECTED] writes:
A partner in a manufacturing effort is sending us full populated
boards (ICs and passive components) that are badly warped. We sent
them back and rather than get the boards remade and repopulate them,
you'll probably get a lot of different answers
150 deg F is not very hot, and this will probably help
but still there will be stresses ...
since this bd is doing 'a very important job'
you may want to tread lightly
what is the measure of 'badly warped' ?
how big is the board and what is the
Further to Steve's point on mechanical stresses on the components...
The feasibility of the suggestion from your assembly house may depend on
where in the process the boards warped. If the bare board was warped when
the solder solidified on the components, then straightening the boards
without
The important sentence below is These boards perform an extremely
important job... My vote would be to have the boards remade, and to
ensure that the unpopulated boards pass inspection before population.
With respect to the existing boards - I'm skeptical that they can be stress
relieved at
I would have to agree with the previous posts that are skeptical
of success with straightening at 150deg F. We typically use FR4 boards
here for characterizing semiconductors at 150deg C. It's not recommended
but it's a reasonably inexpensive way for us to accomplish our tasks
using
Tis truly easy to print direct to a pdf from almost any application,
including Protel EDA. Adobe Acrobat and a large number of third party
PDF printer drivers are available. While Adobe's ~$200 package might
be a bit overkill for most of us, the third party solutions range in
price from around ten
I've beem using a free pdf writer for the last few months without problems.
The free version pops up an IE advertisement when it writes.
_http://www.pdf995.com/_ (http://www.pdf995.com/)
Regards,
Steve Allen
Project Engineer
Manufacturing Services, Inc.
In a message dated