> From:          YAP CHOW LAN <[log in to unmask]>
>
> b) I heard of Rx274s, but wonder if it is really a better alternative to gerber?
>  Can anyone throw some light?  How much does it take to convert one supplier who
> is so used to gerber to support Rx274s?
>
>
> regards,
> stella

            Stella,
      I'd like to add a few comments to the response you received
from Ernie Smith @ Electropac. Firstly, the form is RS274X. You're
showing a couple of transposed letters. Secondly, It *IS* Gerber -
just a safer and more intelligent version for the reasons stated in
the beginning of Mr.Smiths' response. It is also not the first of the
commonly used embedded aperture languages. MDA Autoplot was very
widely used before 274X took over as a more universal standard. MDA
was indigenous to their Fire 9000 plotting systems that some parts of
the country adopted as a standard even though some significant CAM
systems did not have filters in or out for it. AT&T and Gerber
started this new embedded form and pretty much donated it to the
world at large. You do not need to convert or retrain any operators to
any large extent. What is important is that you're on a CAM system that
has the appropriate fields and filters to read in the format. This
your suppler can check with his software vendor.

     As to "typing in" apertures. I'm sure there are a few places by
proportion that continue this practice and I last did only about 4
years ago now. The aperture lists can range to much more than "50".
When we still were typing them, we would see some with lists as great
as 350. These were usually "Master" lists that would be input one time
and then be applied to all of that clients subsequent outputs. But,
not always and this typing thing has all the perils that Mr Smith
noted and more.

    But...It's 1997 and *every* current issue CAM system will have an
auto-input feature that would preclude nearly any typing and only ask
the operator for confirmation at the end of its' read-in or flag
incomplete aperture callouts. This is available  in even low cost
PC CAM systems ( ex.Lavenir, E-Cam, etc.) as well as the larger, more
costly, Unix systems (Valor, Orbotech, IGI, et al). If the system
your supplier is using cannot handle this and for some unbelievable reason,
doesn't even offer it, they can buy one of the inexpensive PC versions
with just that function and little else to front to their current system. But,
I think one call to their vendor and they will likely be on their way
and  will *love* RS274x especially if they've been dealing with
multiple aperture wheels and other such annoyances. You, of course,
get a much better feeling that you fab supplier hasn't incidentally
hosed your design while being able to tool *quicker* without a lot of
time-consuming and unnecessary cross-checking.

    If you find this all as I believe, please consider sending each
supplier a sample file with virtually every aperture you are using
or at least aperture types, as a test and ask for plotted checkfilm
to verify. Then, when you go live with you next design they will be
perfectly postured to go with it.

    I'd say "good luck" but you don't need it. Nowadays, it's kind of
a semi- no brainer.
Brian Nelson
Manager, Strategic Technologies and
Engineering -PWB Division
Sanmina Corporation
San Jose, Ca.
voice: (408) 954-5893
fax:   (408) 954-5880
page:  (800) 759-8888 pin 1271264
e-mail: [log in to unmask]