Kicad footprint

[ronald_dai]

HI all

Can any expert guide me how to generate this kind of footprint?

[RaptorUK]

Draw it in a CAD package (Solidworks, AutoCad, Free Cad, etc.) and import it as a DXF.

[jmk]

The footprint is doable with Kicad if there was more dimensional information. Knowing its purpose may also help.

[paulvdh]

I am not sure what I am looking at.
I’m quite sure it’s some sort of connector, with location pins, and with 8 high frequency connections.

If I were to make it I would just use simple small round (SMT?) pads for the signals, and do the GND zone, via stitching and PCB tracks getting out of the pads on the PCB, and not as a part of the footprint.

With those presumptions, it’s a mostly regular footprint, which is quite easily made in KiCad.

[ronald_dai]

Thanks, I made it by freecad and using the kicadstepup workbench to generate the footprint.

[paulvdh]

The first picture you posted has:

This results in an 0.2mm clearance between the NPTH and copper. From what I remember it is bad practice to drill NPTH though copper. I am not exactly sure about the details, but I guess it is to avoid burrs on the copper.

Recently I looked up a video about PCB drilling, and they put a sheet of aluminum over the PCB before the drilling starts: https://www.youtube.com/watch?v=W130X0kSzYI&t=30s This is also to prevent the copper from being pushed upwards and and forming burrs.

Another improvement is to move the pad number for pad 9 and make it smaller, this can be done with a “number box”. See the post below for more details.

Turn shapes into a pad

The only problem is it creates a mess of the numbering, but i have a feeling im goingto have to live with that? If you don’t like that feeling you could follow these steps: create your custom pad shape as you already have done doubleclick that pad to get the pad properties dialog open the “custom Shape Primitives” pane click “Add Primitive” button, add a number box set the size of the number box - this affects the size of the pad number Attention: this is only valid for v7. v7.99 (==next…

[ronald_dai]

Hi paulvdh

Thank you so much for your help.

I made this footprint with the purpose of doing the signal integrity simulation, so the guide pin with NPTH or plating clearance is not very important for me. for the number pad 9, the post shored by you is very good.

Ronald

[scandey]

Most likely, you will not have any problems doing it the way you show (NPTH into copper) but your fab house may complain. One reason you should care in general is the risk of tiny bits of copper migrating from the hole to places they shouldn’t be and causing shorts, even in handling after delivery. Your fab house may take care of that (pulling back the copper away from the hole in their software) but best practice would be to fix it now.