Giving Nets the possibility to have a Footprint

[tobiasfalk]

I know this is an Idea that is definitely only usable in edge cases but I still want to know if this is a good and useful idea.

I think it would be a nice feature to be able to set a footprint for a net and symbols on a “air” state where the DRC checks that all the connected nets are “air nets”(nets with footprints). It may even be good to add the possibility to say give me two ore tree of this footprint on the PCB.

One of the use cases that I know is if you are working with high resistances you may have problems if you are working on the PCB and you want to put it on teflone standoffs and there the standoff is the “net” and not the symbol/part and if you need to gab a longer distances you may also need to have multiple of the standoffs.

I hereby certify that I am not simply asking someone else to design a footprint for me.

This is an auto-generated message that is in place on the “footprints” section of the KiCad.info forum. If I remove it and ask for a footprint to be designed anyway, I understand that I will be subject to forum members telling me to go design my own footprint or referring me to a 3rd party footprint site.

[BlackCoffee]

@tobiasfalk

edge cases

@tobiasfalk

be able to set a footprint for a net and symbols on a “air” state

@tobiasfalk

put it on teflone standoffs and there the standoff is the “net”

I’m not clear on what you want beyond ability to assign a Net to a Footprint and assign that Footprint to a Schematic symbol (if desired). I have No idea what you mean by ‘Edge Cases’

The above is already standard feature of Kicad, just need to know how to do it. Many posts on doing it/similar…

Can’t have a Net assigned if there is No Copper (Pad, THT, SMD) in the Footprint. Thus, if want Teflon (or other material) Stand-Off’s, then add some type of Copper to it.

Example of some of mine (though, none are Teflon but, that material doesn’t matter - it could be Tofu). The one’s with Copper are assigned to the Net called ‘Tofu’. I added only one Trace to show it’s connected to the Net and the other’s have Air wires… (Tofu name is shown on the segment of the track…)

[tobiasfalk]

OK, I may have described it in a bit of a weird way.
What I want to do is to be able to give the Nets a footprint, to reduce the leakage current, like it is done in things like the Keithley 220 and Keithley 617. Here Part of the routing/wiring is done on top of Teflon Standoffs and to achieve this one would need to give the nets the footprint of the Teflon standoff and at max the symbol has a footprint with designators or so to make placemend easier.
The Keithley 617 Manual gives a good look at how some of these things could be represented(p.52, p.59).

What I meant by switching a symbol to “air” is to make DRC easier, because with this it would make it easier to check if a symbole should have a copper connection on the PCB or only connections to nets that have footprints assigned to.

I understand that one may say that these should not be “normal” nets but may be something other that could connect to pins and so on, but would not result in traces being drawn on the PCB but rather wiring lines.

And I think that this is definitely not a standard use of an EDA because not many will have a situation where the leakage current of the PCB is too high.

[tobiasfalk]

One other use case where such a system would be useful, is if one needs to run a fiber optic line from one end of the PCB to the other and also wants to display this line on the schematic. Here the footprints would be hold downs for the fiber optic cable.

To do these things nicely one would need to be able to set different “classes” of thes not trace connections and are not able to be connected to other “classes”, maybe even set different styles for these classes so that they are visibly different to the nets and other connections.

[LM21]

There are two kinds of schematics. 1. For making PCBs. If you have a floating or off board component, it will surely have connectors or at least holes. Those go to your schematic and PCB, and not the offboard part.
2. Schema which tells how your device works. It has all important parts, and not necessarily connectors, cooling fins and so on. It does not need a PCB, especially because some parts may be off board.

[LM21]

And ofc ourse 3. a hybrid. You can, I think, mark some components as excluded from the PCB.

[BlackCoffee]

… Sort of reminds me of something that happened a few years ago:

When brother was visiting, he wanted some photos that were on my Android phone. I BlueToothed the photo’s to him but, he couldn’t get them on his iPhone.

Not knowing the iPhone, I suggested going to the Apple Store where I knew the Manager.

At the store, I explained the problem and he glanced around the store then, as he reached into his pants pocket, he said while pulling out his other phone, “You can’t do that on an iPhone, that’s why I use an Android”

I’m certain by now, 5 yrs later, the iPhone can now do it. So, perhaps in a few years, Kicad will do what you explained you want…

That said, and, after reviewing your posted links (screenshot below from the Posted Link), my little brain tells me you want to hook up something (a Wire, a Resistor, a Cap, a Whatever…) to the PCB and have it connect to a Trace that has, perhaps, a chunk of Teflon/other between it and the PCB.

If that is correct, my previous post is valid. You simply create the parts you need (such as Teflon Standoff, etc) and place it on a Cu Pad/Trace/other, set it to a NET…

I conclude by showing a simple Wire with Terminal, attached to a Screw-Terminal that sits on a Cu Pad. It could be Teflon or anything but, the screw/other will need to make contact or, you can Ignore DRC Errors/Warnings.

DRC shows only Warning that I did not bother to fix… No Error violations

Screenshot From your posted Link: