# Polygon Strategy

I'm working at a project. Pcb of this project has four layers. And I'm wondering about polygon strategies. Me and my team decided to split polygons. For example at top layer, half side of top layer is power and other half side is gnd polygon. Second and third layers is same top layer. Bottom layer is completely gnd polygon. This methods is true? Or is there a disadvantage this approach? Note : Second and third layer is signal layers.

• Why would you have the ground and power plane split up on the same layer instead of separate layers? And why do you not have any layers for signalling? Normally, you have one inner layer be the ground plane, the other inner layer be the power plane, and the two outside layers be signal layers. And then you divide the the signal layer into different functions, like analog and digital. The divisions are identical for both signal layers since the objective is to have different functions have their own dedicated area on the ground plane. Jul 23, 2019 at 18:42
• I have two layers for signals. Internal,second and third layer is signal layer and this layers have top layer polygon strategy.(half side is power and half side is gnd.) Jul 23, 2019 at 18:43
• Please draw a diagram. Your description does not make sense. You say you have 2 signal layers, but then you say your internal, second, and third layer are signal layers. That makes no sense because the 2nd, and 3rd layers are already internal layers. Even if they were were not, that is three signal layers and you just said you have only two. It also contradicts your original post because in there you said second and third layers are half power and ground planes which are not signal layers. Jul 23, 2019 at 18:49
• I have attached Picture. Jul 23, 2019 at 19:03