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I am facing a kind of dilemma with my PCB design. I am designing a two-layer PCB with the ground plane (GP) on the 2nd layer. I have many tracks that run from one side to the other of the board, hence, to avoid the GP being cut in half, I added many vias. I heard that too many vias are bad.

What is more important: having few vias or keeping the GP intact?

Here is my concerned section, the GP will be on the green side (the yellow line on top and bottom are the edges of the PCB) :
PCB

To keep the GP more intact, I'm thinking about adding other vias on the top, just after the crossing section with red tracks.

The concerned tracks are data. I read that vias can cause trouble in case of high-frequencies, acting as an antenna. At which frequency is it a problem?

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I strongly suggest that you have vertical tracks on one layer and horizontal on the other rather than the somewhat haphazard layout that you currently have. This may seem inefficient but it’s essential for dense PCBs, and you can eliminate non-essential vias once the initial tracking is complete. The inductance of vias is important at speeds in the tens of MHz and above, but are tolerable at higher speeds provided that the proper design rules are followed (impedance and track length matching).

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  • \$\begingroup\$ Doing that will not create some "lanes" in the GP? \$\endgroup\$ Jun 17 '21 at 5:47
  • \$\begingroup\$ Ah I see, I had assumed that you had a separate layer for the GP. For moderate frequencies, say below 10MHz I wouldn’t be worried about having several vias in each track, but the idea of bouncing a track between top and bottom layers does make the layout somewhat complex. You can do it that way though - just be careful not to run two parallel tracks one on each layer. Perhaps consider using ground fills on both layers and stitch them together with lots of vias; then you can use the vertical/horizontal topology and still maintain good GP integrity. \$\endgroup\$
    – Frog
    Jun 17 '21 at 7:41

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