How practically to connect connected pads in footprint


#1

I have defined touch key footprint by placeing many nr 1 pads and many nr 2 pads. They overlap a little.
When I used that key in schematic and start to design PCB I see KiCad wonts me to connect connected pads.

I remind myself (from some discussions here) that KiCad understands track being connected to pad if track covers pad center, but as I sow footprints defined with several pads with the same number I supposed they are assumed to be connected.

How do you practically solve that situation?


#2

If I understand your question correctly, my solution has been to add even more pads - with the same pad number - to create connections. For example, define a pad as, say, 10 mils wide and 100 mils long. This looks and functions the same as a connecting trace, and it can be positioned to create enough overlap that KiCAD recognizes the connection.

I understand that KiCAD 5.x now has a “Custom Pad” feature that addresses some cases like this, though it brings along some restrictions and limitations. I haven’t experimented with that feature yet.

Dale


#3

The biggest restriction that I can think of at the moment for custom pads is no automatic thermal reliefs to filled zones. It is either solid connection to filled zones or manual traces to filled zones. For this application, I don’t see that as a big restriction (but I may not have thought it all our completely).


#4

I have reported a suggestion to assume pads with the same number in footprint as being connected:
https://bugs.launchpad.net/kicad/+bug/1843993

There I was told that a problem of being not connected of pads in my key can be solved
“using rectangular pads with a suitable offset to keep each pad origin inside an other pad.
this is the reason on offsets in smd pads.”

I thought it will work till I decided today to modify my footprint to not have to connect its pads at PCB and failed. Using offsets I have moved a center of all connected pads (except the one assumed to be basic) to be inside the basic pad or inside the pad having its center in basic pad.
But when I put it at PCB (this time I prepared special test project) I got:
PCB

All connection lines are going to graphic centers of pads (like previously) instead of defined centers and pads are not considered being connected. I include zip with that project. There are also my KEY10.kicad_mod.

Before I will question that what I was told there is not true I’d like to ask here: What I am doing wrong?
I am working in 5.1.4 stable Windows.

Test.zip (5.0 KB)


#5

According to:
https://bugs.launchpad.net/kicad/+bug/1844661
it was a bug introduced sometime between 4.0.7 and 5.1.4.