What are stitching GND Vias and are they necesary?

I’m new to PCB Design and Layout and I was just wondering about Stitching Vias and is it necessary to even include.

Doesn’t the board look to cut up/chopped up if we include too many vias? Couldn’t this create potential issues?

They might be useful in some applications. I think high frequency or high current traces mainly. If you want to post a design you can probably get some specific feed back.

You can think of it like microwave door mesh, It attenuates certain signals to such a degree that its practically a Faraday cage,

Same with stitching vias around aggressor or victim traces, its used to contain and attenuate any signals across the via fence

Anywhere a fast or high power signal switches layers, you have to make sure they have there return path maintained, this can mean you have a few vias grouped around areas signals are jumping layers

When you spread them around the ground plane like a seasoning, that is more to reduce inductance across the planes for any unplanned current paths, and to act as a weak via fence across the board to soak up some more noise from traces.

As already said before, extra (stitching) via’s are used for high current traces (A very simple rule of thumb is 0.5A per via) and for high frequency stuff (Which, for digital signals is not in the clock frequency, but in the rise time of the signal) and for screening of High Frequency stuff. For excellent examples, watch a teardown of a spectrum analyzer on youtube.

Another use of stitching via’s is for mechanical strength.
Take for example a SMT connector. These often have mechanical pads with a bigger area to solder to the PCB, but even then they are quite fragile, as the copper on the PCB can be ripped off the PCB itself quite easily. When the mechanical pads of the connector have a few via’s then these pads have a much stronger connection to the PCB.

This is also often used with low voltage, high current applications such as an “ESC” (Electronic Speed Controller), where very thick (60+Amp capable) wires are directly soldered to a PCB.