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For example in a double side board I'm using one layer as gnd and the other layer as power, and then I route the whole circuit inside the planes.

Is that ok? Because I saw that usually both sides are ground. But its easies to me to work one plane as power and the other as ground.

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  • \$\begingroup\$ You can have a look this question and my answer electronics.stackexchange.com/questions/64535/… \$\endgroup\$ – Jesus Castane May 29 '13 at 14:00
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    \$\begingroup\$ As an aside: A power plane, assuming it is decently low impedance, acts as yet another ground plane for AC signals and EMI, so the ground plane sandwich purpose is still met. \$\endgroup\$ – Anindo Ghosh May 29 '13 at 16:00
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For a 2-layer board its pretty common to have one dedicated GND layer and use the other layer for all signals and power. In any case, prevent long traces on the GND layer, otherwise you may have unnecessary long GND return paths (due to the split GND plane/islands).

For multi-layer designs, its good practice to have at least one 100% dedicated GND layer with no excuses. Regarding a supply layer it depends. If you only have one Vcc for example, use a dedicated layer as well. If you require 5V for one localized part of the circuit and 3.3V for another you can place those into the same layer (use planes, not tracks) if you have no spare.

Just keep in mind what you want to achieve: Short, low impedance tracks for commonly used signals (especially GND/supply). With dedicated layers for those signals, you just have to place a VIA.

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