Those IPC specs seem like good candidates, so here's the next question.
On a multilayer board, if the layer construction is not critical, do you
still specify the core/prepreg thickness by part number or just specify an
overall finished thickness?
Interested to here others responses

----------
> From: Davis Ben <[log in to unmask]>
> To: [log in to unmask]
> Subject: Re: [DC] FR4 Material Part Number -Reply
> Date: Wednesday, February 18, 1998 8:57 AM
>
> Larry Campbell wrote:
> >
> > I'm still waiting to hear an answer to the original question.  If
> > MIL-S-13949 is not called out on your fab drawing, then what
> > replacement spec should be called out.
> >
> > Larry
> >
>
>
> Larry...
>
> We call out ANSI/IPC-L-108  for laminates and ANSI/IPC-L-109 for prepreg
> material.  Both have class and type designations.  We still have some
> programs that call out the MIL-S-13949, but I suppose that is because
> the contract pre-dates the spec obsolete date.
>
> Ben Davis
> Systems & Electronics, Inc.
> [log in to unmask]
>
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