I have some power traces (net VIN) in my PCB design that might (in an extreme scenario) carry up to 1A of current. Although nominally, I wouldn't expect to see more than 250 mA. These are 50 mil traces, just to be safe, and since I have to switch layers, I have put two 28 mil hole vias. Is it a bad idea to use double vias like this?
I use multiple vias to connect power traces to other layers all the time on many projects: -
Is it a bad idea to use double vias like this?
No, it's a valid way of doing it. Many of the connections in the picture above use 24 vias. Mind you, the tracks are carrying over one hundred amps and are multi-layer connected.
Not a bad idea. In fact it's recommended when you have high currents and you're changing layers as it reduces track impedance.
There are other considerations like whether to use a couple of large vias as you have, or multiple smaller vias. Ask your fabricator whether this is worth worrying about. Personally, I tend to use the same size via and place them at about 1mm pitch for stitching large current tracks or polygons.
If you have solid planes (ground or otherwise), you may want to try to space the vias in such a way that the planes have connectivity between the vias on the other layers. In other words, avoid creating a "slot" in the plane.
