Electronic – Does layer order matter in a four layer PCB


The PCB doesn't have blind vias. In a four layer PCB the inner layers will often be a ground and a power plane. Does it matter which one you place closer to the component side?

Best Answer

In an ideal world \$V_{CC}\$ is the same as ground for AC signals, and then the order doesn't matter. In practice ground and power net impedances aren't zero and there are noise signals between them.

enter image description here

The picture shows how signals on the top layer are coupled to the \$V_{CC}\$ layer, not to ground. Especially HF signals you'll want on the layer closest to ground, here layer 4.

For low power, LF designs the order will not make much difference.

Picture from this paper