Zones and thermal pads for an SMD LED

Re, I have a question about the surface thermal dissipation and a copper zone :

How can we integrate a copper zone in the thermal PAD (surrounded in green below) ?

Screenshot from 2022-04-30 03-16-04

In Kicad 5 we select the isolated pad to define it in None, but under Kicad 6 The isolated pads are no longer selectable (And in my case they are not displayed because they are not binding to a netlist).

Should we define a LED 3 pin symbol in Schematic Editor and then be able to link it to the PAD 3 of the LED for copper zone ?

Is there a way to simply keep the 2 pin symbol and do this directly on PCB Editor ?

I attach a small test file to open with PCB Editor, it is a single LED to which I want to add a thermal dissipation zone. (5.0 KB)

If someone can explain me :slightly_smiling_face:

Hello @6temrepair

We need @eelik again.
This is a brand new topic that needs to be a new thread so the largest number of people can notice and comment.
Calling @eelik again.

Split into a new thread

1 Like

Thanks, eelik, for splitting this thread!

Editing individual pads was by default possible in v5 but it’s just a quicker way to do it compared to editing the footprint in the footprint editor. When you open the footprint from the board (not from a library) in the editor, you can edit individual pads. If you want the same functionality in v6, see Moving primitives in footprint easily? - #6 by mf_ibfeew.

EDIT: otherwise I’m not sure what you want. One of the most basic assumptions in KiCad (or any other EDA) is that we work with nets, which in the board means copper items connected together. But nets are usually formed in the schematic. Pads which don’t belong to a net can’t be connected to other copper items. Either you should create a schematic and connect the corresponding pin to a net there, or if you really don’t want a schematic, create an ad hoc net in the pcb editor (Inspect → Net Inspector) and change the net of the pad and the zone.

EDIT2: I read the post again and maybe understand a bit better. Yes, using a corresponding symbol with a pin which represents the thermal pad is recommended. There should already be LED_Pad symbol in the libraries.

Thank you @eelik !

Yes I have a little trouble with the transition from KiCad 5 to 6 but we get there :slight_smile:

So I used a 3 pin symbol (LED_Pad), then by creating the copper zone, simply select the Pin 3 and surface thermal dissipation is properly implemented !

The transition from Kicad 5 to 6, allowed me to better understand the operation :slight_smile:

I like KiCad 6 :stuck_out_tongue_winking_eye:

Thanks !

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