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From:
"Thad McMillan" <[log in to unmask]>
Date:
Tue, 31 Oct 95 08:31:17 CST
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I too hate photoploting to inspect a suppliers artwork.  The main
problem for me so far is the $%##@ apertures.  Unless you are
generating a gerber format which has embedded apertures (which our
company will do shortly) there is a definate non-zero chance that the
apertures will be screwed up by a fab house when they load the
apertures, particularly custom shapes.  I have lost count of the
number of times we've have apertures rotated or loaded incorrectly.
We've caught numerous errors with various suppliers at the film check
stage.  Part of the problem is that CAD systems and various
customers have a wide number of ways of outputing apertures.
It's tough for any fab house dealing with the multitude of aperture
outputs.   When customers universally start using embedded
apertures, the need for check film should go the way of the dinosaurs.
          (I hope)

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----------------------------------------------------------------------


Save your company $$$.

Unless your company or department is new, why continue to photoplot your pcb's?
I can expect to see designers new to a particular cad system, or unsure of a
new vendor to repeatedly request photoplots.

Once you have your methods defined, viewing photoplots should not be req'd.

Companies can spend thousands of dollars on photoplots, and for what? Just to
allow some inspector to get that warm fuzzy feeling.

Fab houses don't want to use them. It makes more sence for them to use the
gerber files. It's much more accurate to build from the gerbers.

I'm sure there are many companies out there, who's back rooms are filled with
filing cabinets, stuffed with old photoplots. I've seen countless companies
spend much more than they should to perpetuate such an obsolete system.
You're not alone, my company did it for years. I suppose there are still some
fab shops out there who can't use gerber files, but they must be shrinking in
number.

For now, pcb fab shops must produce film and charge us for it. But in the 
future I think photo-tools will be eliminated. Why archive an obsolete piece
of film?



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