Jack,
I agree with Frank, The drawing is one of the controlling documents and is
contractually binding (just check with most procurement (purchasing)
personnel). If you specify garbage, you should get garbage. Unless there is
another document (Fabrication Spec.) that controls your dimensions (any
dimension) are to be within the tolerances on the Fab. Drawing. Without
written deviation approval if they are out of spec. (tolerance), it is
reasonable to reject the boards. (ask most Quality Assurance Personnel).
If you can't live with the deviation(s) send it back.
Best of Luck,
\\\V///
©¿©¬
(--)
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]>
"Routing is not just a path; It's an Art."
-----Original Message-----
From: Kimmey, Frank [SMTP:[log in to unmask]]
Sent: Thursday, February 18, 1999 10:26 AM
To: [log in to unmask]
Subject: Re: [DC] PCB thickness & tolerance
Hey Jack,
I have a condensed version of DOD-D-1000 that says:
"10.4.2 STANDARD TOLERANCES - Dimensions shown without tolerance are
controlled by the standard tolerances in the title block..."
Sounds to me like your vendor owes you one.
Hope it helps
FNK
Frank N Kimmey C.I.D.
EM Designer
C & K Systems, Inc.
916-353-5366
[log in to unmask]
> ----------
> From: Jack Olson[SMTP:[log in to unmask]]
> Reply To: DesignerCouncil E-Mail Forum.;Jack Olson
> Sent: Thursday, February 18, 1999 7:55 AM
> To: [log in to unmask]
> Subject: Re: [DC] PCB thickness & tolerance
>
> Thank you for answering this... At least I know I'm not losing my
mind
> trying to find it in IPC, (I'd rather lose my mind for other
reasons,
> eh?)
>
> The problem was that the vendor says its not their fault if the
board
> came
> in too thick, because the callout was ".093 nominal" with no
tolerance
> callout. I say if there is no callout then they have to use the
one in
> the
> title block "all three-place dimensions shall be .xxx unless
otherwise
> noted", right?
>
> Anyway, thanks for all the responses....!
>
> Jack
>
> -----Original Message-----
> From: Cosentino, A. T. (Tony)
> [mailto:[log in to unmask]]
> Sent: Thursday, February 18, 1999 5:56 AM
> To: [log in to unmask]
> Subject: Re: PCB thickness & tolerance
>
> Jack,
> The old MIL-STD-275 had a design guideline which
> stated
> +/-10% or 7mils
> whichever is greater. IPC-D-275 and IPC-2221,
which
> are
> both design
> standards, do not specifically call out board
> thickness
> tolerances nor
> do they publish any guidelines. I would stick with
the
> +/-10% rule for
> anything 70 mils or greater and +/-7mils for all
other
> boards unless you
> have a specific application which requires a
> controlled
> thickness under
> these limits. I would then work closing with a
board
> vendor
> to achieve
> my desired results.
> Anthony T. Cosentino
> Lockheed Martin
> (703)367-1144
> [log in to unmask]
>
>
>
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