1.High-speed circuit and low-speed circuit: high-speed circuit should close to the ground, low-speed circuit close to the power surface.
2.The alignment of the adjacent layers is orthogonal to avoid the different signal lines in the same direction getting the same direction, to reduce unwanted interlayer interference; especially when the signal rate is high, you should consider using ground plane to isolate the wiring layer and signal lines to isolate the signal line.
3.One end of the floating wiring is not allowed to avoid the "antenna effect".
4.Impedance matching check rules: the same grid wiring width should be consistent, line width changes will cause the line characteristic impedance is not uniform, when the transmission speed will produce high reflection. In design, you should avoid this situation. Under certain conditions, the change in line width may not be avoided and the effective length of the intermediate inconsistency section should be minimized.
Statement: This post is only the personal view of the author and does not represent the opinions of ALLPCB.com.