(1) power plane should be near the horizon, tightly coupled with the ground plane, and arranged under the ground level.

(2) signal layers should be adjacent to the inner layer should not be directly adjacent to the signal.

(3) digital circuit and analog circuit isolation. If conditions allow, to analog signal and digital signal cables hierarchical layout and shielding

Measures if necessary in the same signal layout, you need to use tape, and line reducing interference; analog circuits and digital circuits

Power and ground should be isolated from each other, can't be mixed.

(4) external interference of high frequency circuit is large, the best single, use has layers within layers directly adjacent to the intermediate signal transmission, to

Then layer of copper thin film using less foreign interference.