What is the purpose of the VIA stitching in PCB design

[Eevbs]

hello,

can anyone please explain me what is the purpose of the VIA stitching in PCB design or PCB prototype? what it does? does it only important in multi-layer PCB's?
i design 195W DC/DC power supply,  do i need to add that to the power tracks ( i have one or maybe two layers PCB)?

thanks

[Ice-Tea]

Mostly done on ground planes. You'd want that if you have a ground plane on top and bottom that for all intents and purposes they can be seen as a single continuous ground plane. So you need to make sure the connections between top and bottom are not far apart but pretty close to each other so that return current does not have to travel far to "jump" layers.

[Rerouter]

It is all about return path impedance, you likely know about the path of least resistance, but as your frequency (transition speed) increases, a greater share of the return current will try and follow as close as possible to the signal above, via stitching is a way to ensure that there is a smaller gap between them, as any deviation is both a noise source and seen as impedance,

If your edge rates are getting close to a 10Mhz sine wave, you follow the path of least impedance, and plan around that, above a 1Ghz sine, you ignore the path of lease resistance and focus only on impedance,

It can all so be used to increase power heatsinking on the board, if you have a lot of via's into a big ground plane right next to a high current power trace the increased surface area will soak up the heat better and let it run cooler,

[Torrentula]

Also done near or under surface mount power components to spread the heat to another (maybe bigger) ground plane on the other side of the PCB, also called thermal vias.