kicad-developers team mailing list archive

[David Godfrey <info@xxxxxxxxxxx>]

On 20/08/15 22:36, Tomasz Wlostowski wrote:
> On 20.08.2015 16:29, Jeppe Johansen wrote:
> > Hi,
> >
> > I've been working on adding support for entering stackup information and
> > using that info when length tuning traces.
> >
> > Some screenshots:
> > http://j-software.dk/kicad/thickness.png
> > http://j-software.dk/kicad/length.png
> >
> > Patch here(warning, back up any .kicad_pcb files before you save. The
> > format is changed to include layer heights):
> > http://j-software.dk/kicad/kicad_stackup.patch
> >
> > Getting it into the meander placer required a bit of hacking to process
> > vias and find all segments connecting to it. That part is a bit ugly,
> > but it works. Also the length calculation is duplicated for each tool
> > variant. Unifying those in a single place would be great. For now my
> > patch only modifies the single trace length tuner.
> Hi Jeppe,
>
> Thanks for the patch.
>
> I'm not sure if we should define separate layers for cores/prepregs,
> though. How are they going to be stored in .kicad_pcb file? What if
> there is more than one layer of dielectric between each two adjacent
> layers? Maybe a new dialog for defining the complete stackup (including
> dielectric factors, losses, etc) would be a better idea?
>
> Regards,
> Tom
Hi All,

I agree with Tom.
A new dialog that allows definition of the layer stack with all 
paramaters including dielectric characteristics would be preferable.
In the future we could use this information to auto calculate impedance 
of striplines etc as well.

Regards
David