Hi,
Byt the way, i can not understand one thing, you said ''And connect the other side of the capacitor as close as possible with a via to GND''
I have top and bottom GND polygon, and all capacitors have connection between top GND. You mean, connect them with via to bottom polygon to?
In the picture as you see the C3 capacitor is connected to top layer GND, do you mean add via to connect C3 to bottom GND also?
as already said in post#4:
A copper pour is no GND plane....
The TOP is a copper pour - it is cut in pieces, thus see it as wires not as GND plane.
But your BOTTOM plane is a GND plane.
--> add a via as close as possible at each TOP GND to get shortest connection to BOTTOM GND plane.
******
I´m no friend of copper pour at all. (personal taste), I rather connect each TOP GND signal directely to BOTTOM GND plane.
Klaus
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added:
Many people see a signal as if it has a
beginning and an
end... but every signal need a return path. (Especially HF paths, pulsed signals, EMI, EMC...)
Thus one should treat every
signal as a loop. In most cases the return path is via GND.
And (one of the) the best return path follows exactly the signal path but on the opposite (next) layer. In your case the bottom layer.
TOP copper pour can not fulfill this recommendation.
But a solid GND plane can. But every cut in the BOTTOM layer (that is in the area of the TOP signal path) makes things worse. It forces the return current to leave it´s optimum path.
Klaus
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Hi,
My opinion:
Nowadays with HF, SMPS and/or high dV/dt or dI/dt signals...you can´t do without a proper GND plane. The risk for EMI/EMC problems is too big. The risk for bad performance (noise) or malfunction is too big.
There is no problem if a hobbyist´s circuit will fail ... but there are more risky circuits like airbag or an elevator control...
Thus I optimize the GND plane to have the unavoidable cuts - short and away from critical signals. I usually don´t use a copper pour as additional GND on other layers. Just very short traces and one or multiple vias to the GND plane.
Klaus