Is It Standard to Route Power Traces Before Pouring Planes?

Signal and Power Power Integrity
1

Hi community,

I’m designing a multilayer PCB for the first time and currently working on the power distribution layout.

While watching a YouTube PCB design tutorial, I noticed the designer first routed a trace for a power net, and then poured a copper zone (plane) over the same net.

This got me wondering — is this a standard or best-practice approach?

In my case, I’m using 1 oz copper and the power net is expected to carry up to 3 A of current. I’d really appreciate guidance on whether:

  • I should always route a trace before pouring the zone,
  • Or if it’s acceptable to use only the plane when properly connected through pads and vias.

Thanks in advance!

image
image620×378 23.7 KB

1 Like
2

Power nets can be done either way. If you need to be sure of minimum widths, there is advantage in routing a track early to verify that minimum width has been considered. You can always come back later and adjust if you find that is causing you a routing issue and it will only need to be reduced for a short distance. If you are using Width rules, those rules will check for track and arc widths, but not check for polygons, fills, or solid regions.

Example, I tend to route bypass caps to ICs and vias to other layers early in the process to be sure that has been accounted for. Otherwise you may find that you will not leave enough room for optimal placement/connectivity. I add polygons later after the routing is completed.

3 Likes