Power line. One via or multiple vias?

Thread Starter

Axel_sr

Joined Feb 28, 2022
47
Hello,

I am sure that the topic is discussed several times, but based on a surface search I couldn't find exactly the answer I was looking for. So, I have a 4 layer board. Middle layers GND and Power.
Bringing GND and Power to the top layer, is it better to use only one via or should I use two or more vias? Via size is 30/15 mils and needed current is max 20mA (on a single point of via(s) ). So in terms of the current, definitely one via can handle that.
So far I have followed the rule that more than one via is needed only below a heat pad (in the name of heat dispatching).
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dl324

Joined Mar 30, 2015
16,687
Bringing GND and Power to the top layer, is it better to use only one via or should I use two or more vias?
It depends on the circuit. Are you using ground and power planes because you need them? How large is the board?

If you're using them for shielding, it's better to have multiple tie points to the power supply.
 

Thread Starter

Axel_sr

Joined Feb 28, 2022
47
hi. The board is 35x100mm. 4 layer board is needed due to components and dimension limitations. Without ground/power planes it would be "impossible" to route.

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a
 

dl324

Joined Mar 30, 2015
16,687
So far I have followed the rule that more than one via is needed only below a heat pad (in the name of heat dispatching).
I'd put in as many vias as possible under heat dissipating pads. More vias will lower thermal resistance.

Otherwise, if the planes are for routing convenience only, no need for more than 1 via.
 
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