kicad-developers team mailing list archive

[Jeppe Johansen <jeppe@xxxxxxxxxxxxx>]

On 08/20/2015 04:36 PM, 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 Tom,

I was thinking about that. It might be the cleanest and best route to 
take in the long term.

Having a seperate structure that could describe fairly arbitrary data 
about the stackup would be nice. I'm not sure how the big PCB design 
tools handle flex PCB's for example but that would probably also require 
some fairly specific information.

Do you have any insight on the FindSegments hack I made? The problem was 
that depending on if you work backwards or forwards on a line segment, 
finding all the segments that connect to a via is not possible. Only one 
segment is added as a link to the PNS_JOINT for a given via. Is this a 
bug or work in progress still?

Best Regards,
Jeppe