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Altium PCB Design

Sarah Ali , 10-18-2024, 09:01 AM
Hi all, I need 4 Layer PCB Design What is better to stack up (SIG-CND-SIG-SIG) or (SIG-GND-POWER-SIG)? my project is GPS

Another question about the whats the purpose of the Polygon Pour ? and how it will reflect on actual pcb board ?

and when I use Top layer for signal can I use the Polygon on it and connect it with GND net Although when I used the Layer special for Ground (Ground plane )

please if anyone here can answer my questions .
QDrives , 10-21-2024, 08:17 PM
There are many opinions that state that (A) is better than (B), but (C) is the best.

Here are my opinions...
If you have the ability to have 2 plane layers, it is best to do so.
If power and are closely coupled (<= 0.2mm) you benefit from the plane capacitance. However, in a 4 layer board, either the outer layers have a close coupling, or the two inner ones. Never, both (except for thin <= 0.8mm boards)

Do you need a power plane? If not, it is easier to have 2 Gnd planes.
Crossing the signals from L1 to L4 requires a return via. For a power plane, you cannot couple with a via so you need a capacitor.

A 'plane' layer can either be done using an actual plane layer, or by a signal layer and a big (Gnd) polygon pour on it.
In you first stack-up (Sig-Gnd-Sig-Sig) you need a polygon pour on L3 to balance the copper that is on L2. Otherwise you board will bend.
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