Filled zone & Layers

Layout
1

Hello everyone,
I’m new to Kicad (version 6.0.5-0) and I made an audio preamp PCB with OPA. The board will be soldered with only thru-hole components. The voltage supply here is +/- 18v.
A friend advised me to work in four-layers mode and here’s how I distributed them:

  • Layer 1 (top) = audio signal
  • Layer 2 = audio ground
  • Layer 3 = V+
  • Layer 4 (bottom) = V-
    I set all the pads to F.Cu, B.Cu and connected layers and asked for thermal relief which I set to 0.5 (spoke) and 0.5 (gap).
    Now for maximum RF protection I add a filled zone on layer 2 (2nd from top) which is audio GND. Then I read in Kicad doc. that a filled zone can’t be directly connected to any layer and I noticed that in the concerned layer (2) the pads & tracks are “isolated” from the filled zone. So I set one of these pads (R99) as connected to all cooper layers where I will connect the PSU ground to the audio ground.

My questions are :slight_smile:

  • Is it a good way to proceed ?
  • can someone have a look at how I arranged the different layers ?

Then another point : since I will connect wires to the board I add some pads chosen in the connector wires menu but some of them refuse to be paired to the net I’d like : more precisely, the net to which I wish to associate them does not appear in the possible choices of the drop-down menu so I added some resistor’s footprints where I will able to solder my connected wires instead of putting a resistor…

Then a last point : I did not find a dedicated footprint for a TSSOP14 adapter in my footprints library so I drew one in the FP editor (U1 on the schematic) > maybe it’s because my Kicad version is not recent…

Thanx in advance for your help

Layer 1
Layer 11896×1342 356 KB

Layer 2
Layer 21898×1354 337 KB

Layer 3
Layer 31902×1346 251 KB

Layer 4
Layer 41896×1344 343 KB

Layers all
Layers all1900×1352 401 KB

Regards

2

Sorry I don’t have comments on your layout, but is there a reason you are using the ancient 6.0.5 version? In your place I would start with 9.0.2 (your project is unlikely to hit the edge case bugs currently being sorted out), or 8.0.9. You don’t have to start again, KiCad can convert your project.

Many people have forgotten how the menus are laid out, or whether a certain capability was in v6, so you will get better help with a recent version.

3

Thank you for your advice but for some personal reasons my macOs is old (Mojave 10.14.6) and does not support Kicad 9 so I"m in trouble with getting some help I guess :woozy_face:

4

No, not true, even in such an ancient KiCad version, you can simple edit the zone properties, and then set a net name for the zone. And then after a redraw with b, the zone will connect to all pads with that same net name.

5

Macports has v7.0.11 which is an improvement:

https://ports.macports.org/port/kicad/

https://ports.macports.org/port/kicad/details/

6

Thank you, you’re right. I did connected the filled zone to some pads but why does it refuse to connect to pad already connected by a track ? In the scrolling menu not all the available pads are shown…

7

Thank you ! I’m trying to install and then run this version

8

Well… I have to update my Mac’s OS to Monterey (which is compatible with the last Kicad version) but I must do a complete back-up before that

9

Not Kicad per se, but you probably should not have two ground planes tied together.
Make them both “ground."

10

You mean the ground tracks + pads ? The pads should be instead directly connected to the filled zone ?