In a previous discussion, I asked about designers calling out
specific material thickness/stackup versus just calling out the
desired finished board thickness. The general consensus was that
unless there is a good reason for specific materials and thicknesses
(for impedance control) it would be best to let the vendor decide
the best stackup for a particular design.

In another discussion about impedance control, the question was
whether the designer should take it upon himself to do all of the
calculations, or to just try for appropriate trace widths and call
out the desired impedance for those particular traces. The general
consensus was that if the designer did all of the work and told the
vendor exactly what to do and it came out wrong, the designer had
only himself to blame. If he calls out only the desired impedance
and lets the vendor "tune" his process for it, the vendor is to
blame if it comes out wrong.

Well, I'm not trying to illustrate how we as designers should do as
little as possible and leave responsibility with the vendor... and
there sure has been a lot of talk about "Design for Manufactur-
ability" and how we should do our best to learn what's going on
instead of just "throwing it over the wall". Yet when you try to get
educated, you are told to "leave it to the vendor".

What's a designer to do?

Just a semi-casual thought (not trying to start any wars or anything)

onward thru the fog,                                    Grasshopper

p.s. Have a nice holiday you guys, I'm outta here...

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