I am designing an SMD PCB to control two motors that consume 6 A each. I have too many components and I am using 4 layers, so I want separate the tracks. I have found out that the tracks with high current must be in a external layer. I have been thinking in use this organization layers:
- Layer 1: Power.
- Layer 2: GND.
- Layer 3: Communication signals (signals that changes their value in very short time, thus are very sensible to noise, for example Serial communication of ESP32 or PWM).
- Layer 4: Control signals (digital pins that change their value between Vcc and Gnd but keep their value steady by a long time,for example the control of a LED).
I want to use a ground plane but in an internal layer, because I found that the ground must be near of the rest of signals. About the communication and control signals tracks must be separated for avoid interference between them, but I am not sure about the minimum distance between the tracks.
About the heat dissipation, I know that the high power components must be separated of the other components but I am not sure if can I put components in the opposite side of a high power component.
For example the MOSFET connected to MT1_2 is in top plane, is a problem if I put a resistance or IC in the same ubication that the MOSFET but in botton plane?