Needing more than a spark test?

[homebrewed]

A physical hole is a great keep out. I actually want the opposite. I want to install components in the same area as the display is. The display only connects to the board via vertical standoffs and a single row of pins. My keep out would be the union of keep out around the header, and the 4 non plated through holes, but allow component placement anywhere else. Just like in these two pictures of my ELS board.
View attachment 438092View attachment 438093
I did this board in a way I do not want to repeat. So I want to build the display as a component with a keep out of only the header location and the four standoffs. Everywhere else should be able to have components on it. The white line is the silkscreen for the display location.

You could shrink the display footprint to just the connectors. Kicad won't know or care if the bulk of the display is hovering over other components.

 

[graham-xrf]

A physical hole is a great keep out. I actually want the opposite. I want to install components in the same area as the display is. The display only connects to the board via vertical standoffs and a single row of pins. My keep out would be the union of keep out around the header, and the 4 non plated through holes, but allow component placement anywhere else.

It looks great!
Not to be a killjoy, but one hopes there is nothing going on in that display that it going to "contribute" to what the high gain amplifier sees.
I guess the ground plane would be effective.

 

[WobblyHand]

It looks great!
Not to be a killjoy, but one hopes there is nothing going on in that display that it going to "contribute" to what the high gain amplifier sees.
I guess the ground plane would be effective.

It is a concern. Displays are not known for being super quiet, nor is SPI communications. The back side of the display is ground plane with some coplanar waveguide like connections to a couple of small components. The actual drivers for the display are under the physical display on the front side. On my new design, there will be a wiring layer, a pair of power planes and another wiring layer. Probably will put the detector on the back side. Have to think about it.

That board pictured above is my ELS design, my first ever in KiCAD. Worked the first time. Rev 0.1. Besides minor cosmetics, there's no need to modify it - works great on my lathe. Four layer design. Two wiring layers and two power/ground planes. Built with through hole parts, because that is what I had at the time.

 

[rabler]

So far, I think I heard disjoint courtyards are allowed in V7. How do you group the courtyards together? Doesn't a footprint do this automatically?

I wasn't clear. I'm grouping the objects in the PCB layout, not in the footprint. Doing it in the footprint would certainly be more useful which is why I was curious about what you heard from the forum. But at least by locking and grouping them, it is harder to accidentally move or delete one of the holes. I did that (delete one of the holes) on one of my board spins. Didn't notice it until I got the boards back from fab.

 

[rabler]

There absolutely has to be a no-go area. It's a very common thing to need, especially for bpoards that have to be bolted up against other assemblies. I will have a look soon.

Kicad does have keep-outs. They call it a "rule area". You can selectively exclude tracks, vias, footprints, and copper fills/pours. And it can be applied to a selection of layers. It is the grey polygon, two down from the via tool, on the right side toolbar. I'm not sure if they can be associated with footprints.

Editted to add: it appears that in Kicad's footprint editor, you can add a rule area under the "Place" drop down. Didn't explore it beyond noting it is there.

 

[WobblyHand]

I wasn't clear. I'm grouping the objects in the PCB layout, not in the footprint. Doing it in the footprint would certainly be more useful which is why I was curious about what you heard from the forum. But at least by locking and grouping them, it is harder to accidentally move or delete one of the holes. I did that (delete one of the holes) on one of my board spins. Didn't notice it until I got the boards back from fab.

No problem. The KiCAD forum isn't quite as friendly as here. I haven't quite got a definitive answer yet. I got an answer of "oh yeah that's in V7, I think", and "why don't you try it", neither of which sound definitive to me. I am trying it with a dummy design, but it's not behaving the way I expect just yet. I found out I need to add the holes to the edge cut layer, so I have to go back and edit the footprint I made.

On my ELS, I embedded the holes in the board outline. This is not flexible at all. So this try, I am going for embedding this stuff into the footprint, so I can move the display if needed.

 

[rabler]

No problem. The KiCAD forum isn't quite as friendly as here. I haven't quite got a definitive answer yet. I got an answer of "oh yeah that's in V7, I think", and "why don't you try it", neither of which sound definitive to me. I am trying it with a dummy design, but it's not behaving the way I expect just yet. I found out I need to add the holes to the edge cut layer, so I have to go back and edit the footprint I made.

On my ELS, I embedded the holes in the board outline. This is not flexible at all. So this try, I am going for embedding this stuff into the footprint, so I can move the display if needed.

As an alternative to adding holes to the edge cut layer, I have just added "mounting holes" to a footprint. Looking at that in Kicad it doesn't show anything in the edge cut layer, but I know it produces a working hole as I've used it.

 

[rabler]

@WobblyHand: Given the footprint can incorporate "rule areas", you could try using that as an alternative to the courtyard in defining the display part. Rule areas are pretty flexible and might allow you to effectively do a multi-area keep out.

 

[WobblyHand]

I think I got it, or at least good enough for me. Here is a dummy design that fully passes DRC, for a Teensy 4.1 connected to an ILI9341 display. I made Gerber files and it seem the NPT holes are in the right places. They are the cyan 4 circles in the corners of U2.

The holes follow the pads, which is what I was looking for. And the NPTH generates an easement around the power planes, so I guess it is all good.

 

[graham-xrf]

I have just installed, but not yet explored Kicad V7.
I have gone from Kicad V5 through to Kicad V7 in fewer months than they have version numbers
Looking at the release notes, and animated illustrations of what the new stuff does is a bit surprising.
Kicad is getting better faster than I can learn how to use it.