kicad-developers team mailing list archive

[Mark Roszko <mark.roszko@xxxxxxxxx>]

I feel the via filling option in the job spec is too limited At my company
we probably have a few hundred boards where we do via fills depending on
their diameter. We keep their usage the same based on diameter, i.e. 8 mil
vias go in pads, 6 mil vias are used in impedance controlled traces.And I
know my company isn't the only ones that do this. (I've seen it on some
Google internal boards notes).

We end up having specific instructions such as:
Plug all vias that are 0.008 mil diameter with nonconductive epoxy
Plug all vias that are 0.006mil diameter with conductive filled epoxy
0.012mil vias DO NOT FILL OR PLUG. MUST BE FREE OF MASK.

Basically a big thing with higher density boards mixed with high speed
digital and high power electronics :/





On Tue, Sep 19, 2017 at 2:33 AM, jp charras <jp.charras@xxxxxxxxxx> wrote:

> Le 11/09/2017 à 19:12, Simon Küppers a écrit :
> > Yes, a common stackup would be a two-layer rf substrate such as Teflon
> pressed onto a two-layer fr4
> > core with an fr4 prepreg in between. Galvanic processing is then done as
> usual.
> > Best regards
> > Simon
> >
> > Am 11. September 2017 19:07:19 MESZ schrieb jp charras <
> jp.charras@xxxxxxxxxx>:
> >
> >     Le 01/09/2017 à 12:38, Simon Küppers a écrit :
> >
> >         I was also about to show the optiprint brochure, thanks. I fully
> agree with you. We
> >         especially like
> >         to use Teflon materials with thick copper backing, but fr4 plus
> ceramic is also quite common
> >         here.
> >
> >
> >
> >     Hi Simon,
> >
> >     Do you mean the *same board* has (for instance for a 8 layers board)
> the 2 external dielectrics made
> >     in Teflon and the 5 internal dielectrics use fr4 and prepegs?
> >     I am seeing the interest, but this is unclear for me when reading
> brochures.
> >
> >     (The Gerber job file format is currently being finalized, and can be
> slightly modified)
> >
>
> Your answer was very useful.
>
> The Gerber job file format was just modified to specify more than one
> substrate material.
> Do you (or others RF specialists) know (besides the Teflon) other
> materials used in such boards.
>
> Thanks.
>
> --
> Jean-Pierre CHARRAS
>
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-- 
Mark