Are There Advantages and Disadvantages of Using a Split Plane on a PCB Layout to meet MIL-STD-461G?

There are advantages and disadvantages to splitting a PCB power plane to meet MIL-STD-461G EMC limits. Some of the benefits split into power planes are as follows:

• Split planes separate power and ground, reducing the amount of Electromagnetic Interference (EMI) between these signals.

• Split planes allow for separate power distribution to different parts of the board, reducing the effects of power drop and providing a cleaner power supply.

• Split planes provide a clear physical separation between signals, reducing the amount of crosstalk and improving signal isolation.

On the other hand, splitting power planes also have disadvantages as follows:

• Split plane designs can be more complex to implement and require more layers in the PCB, making them more expensive to produce.

• Noise will be introduced into the power and ground planes, affecting signal integrity if the design of the split into the PCB planes implementation is wrong.

• Connecting the signal traces on different planes may require routing traces across split planes, which is challenging and would require adding vias and stitching to connect the various planes.