In our tests, the vellum was heated in the printer and passage through the
device caused the long axis to be stretched. We got better results printing
to paper and then using a Xerox machine to transfer the image to vellum.
-Stan
> -----Original Message-----
> From: Russel Pringle [SMTP:[log in to unmask]]
> Sent: Friday, October 08, 1999 5:50 AM
> To: [log in to unmask]
> Subject: Re: [DC] Looking for a photoplotter (part 2)
>
> Jimmy,
> At the last place I worked, we were trying to do something very
> similar with verifying land patterns for large QFP devices. Between the
> Data
> sheets and the CAD automatic conversion from mm to inches (can you say
> rounding off error) we went to placing the devices on the plots. We very
> quickly found that our Laser-Jets and Design-Jets (and every other
> plotters
> we could find in the company) had a long axis error, we concluded that the
> was combination of paper/film creep and stepper motor tolerances. Of
> coarse
> the short axis within a mil-of-perfect so, we rotated the device and
> plotted
> the other axis (along with correcting the dimensional errors). This
> allowed
> us to get the pattern close. After that we sent it to the photo-plotter
> for
> one last check. I agree with Ray that these plotters and printers are
> great
> and color plots are the way to go. With your statement about wanting to
> overlay "plots" on to the board I was reminded of the hassles that we went
> through. If this (overlays plots on a board) is the ultimate objective,
> then
> accuracy will be an issue and don't forget the FAB allowances on the
> board.
> Accuracy "can" cost big bucks.
> Best of Luck,
> Russel W. Pringle, C.I.D.
> Halliburton Energy Services
> Wireline Development
> (281) 596-6620 Fax: (281) 596-4279
> [log in to unmask] <mailto:[log in to unmask]>
>
> -----Original Message-----
> From: Ray Humphrey [SMTP:[log in to unmask]]
> Sent: Thursday, October 07, 1999 9:26 PM
> To: [log in to unmask]
> Subject: Re: [DC] Looking for a photoplotter (part 2)
>
> Jimmy,
> Many modern printers and plotters will do what you need. I use an
> HP
> DesignJet 650C, which will plot on a variety of paper types plus
> inkjet film
> and vellum. InkJet printers will handle glossy film and
> transparencies,
> too. Then benefit of using one of these options, rather than a
> photoplotter, is that you can get your film printed in color, if
> you
> like.
> The quality is very good with the cost being very low. Some
> laserjets will
> also handle transparent films.
>
> Ray
>
> ----- Original Message -----
> From: Jimmy Blier <[log in to unmask]>
> To: <[log in to unmask]>
> Sent: Thursday, October 07, 1999 6:23 PM
> Subject: [DC] Looking for a photoplotter (part 2)
>
>
> > Hi Tom,
> >
> > I think I might have been unclear when I asked my question.
> > I'm looking for a printer that does films, just like the one
> your
> films
> > manufacture does but ((((cheaper!!!))))
> > I'm not looking for a (Fire 9000) are anything in that caliber.
> All I
> want
> > is just a way to print films on a clear plastic sheet with a
> reasonable
> > precision and reliability.
> >
> > We want to superpose to films over our incoming PCB's to verify
> in
> the
> > manufacture is doing everything as they should. We made some
> tests
> and so
> > far it looks very promising. We can verify the soldermask,
> traces,
> > silkscreen and drill sizes in the blink of an eye. But we don't
> want the
> > rely on a local film factory to generate the films for our
> boards
> made in
> > Hong Kong, we want this a bit more home made. :)
> >
> > Cheers,
> >
> > Jimmy Blier
> > CAD Department. (Supervisor)
> > P A R A D O X
> > S E C U R I T Y S Y S T E M S
> > Email: [log in to unmask]
> > Phone: (450) 491-7444
> > Fax: (450) 491-5940
> >
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