Hi there. I was following the popular DigiKey YT tutorial on KiCad, and towards the end of the process, copper pour zones for GND are introduced. I used this successfully on my front side, but I wonder if there is any reason / advantage why one would do this as well on the bottom side in a case like mine, where I can comfortably connect the remaining eight pads that need GND with a straight thick trace. Other than that, my bottom side only contains two signal traces. For comparison, here are my front and back Cu layers (GND on the bottom is the thick vertical line on the right-hand side):
Would you advise changing my single thick bottom GND trace with another pour / zone? Is it somehow better protected, or does it just make the process more expensive?
Board houses like to have copper balance, meaning that the amount of copper should be approximately equal on both sides. I have no experience, how relevant this is for comparatively small boards like yours, but anyways…
And: no, it does not infer additional cost.
Once you get into higher speed signal handling, a continuous (uninterrupted GND plane becomes mandatory. On top of that a good GND plane increases signal integrity and reduces radiation and is therefore better for EMC.
I can see the first layer has a lot of red, but the resolution is too low to judge if it’s a decent GND plane.
Instead, I’d forget about the top layer and use the whole bottom layer as a continuous GND plane.
If you want to do this right, then that also means you have to remove that single green track from the bottom layer, because it interrupts your GND plane.
One way of doing this is to rotate those 8 resistors by 180 degrees, and then route that track around the connectors on the right side. Another way is to just rotate those resistors 90 degrees and use them as hop-overs for the horizontal tracks. This would “collect” all pads of the net that is now green in a small area in the center of the PCB.
There are no costs involved for you. Once you have a dual-layer PCB, the PCB manufacturer does not care how much copper you put on the PCB.
Some say that having a lot of copper on the PCB could make it slightly (maybe a cent or so) cheaper because the copper does not have to be etched away, and it saves etchant. Usually the copper is also 17um thick on the pre-preg, then te holes are drilled and the holes are plated with electrolysis, which also thickens the copper over the whole PCB area to 35um.
Offtopic
I wonder how much money PCB manufacturers could save by:
Drilling via’s
Applying a mask to make big area’s non-conductive.
Electro plating the via’s and other still exposed copper.
Removing that mask and applying a “normal” mask for the rest of te PCB proecess.
