PCB Reverse Engineering Layer Design

How to do a good job in the PCB reverse engineering layer design to make the PCB’s EMC effect optimal?

From the design idea of ​​PCB layer:

The core of PCB stack EMC planning and design thinking is to reasonably plan the signal return path, and minimize the signal return area from the mirror layer of the single board, so that the magnetic flux can be canceled or minimized.

The mirror image layer is a complete copper-clad plane layer (power layer, ground layer) inside the PCB adjacent to the signal layer. The main functions are as follows:

(1) Reduce the return noise: The mirror layer can provide a low impedance path for the signal layer to return, especially when there is a large current flowing in the power distribution system, the role of the mirror layer is more obvious.

(2) Reduce EMI: The existence of the mirror layer reduces the area of ​​the closed loop formed by the signal and reflow, and reduces EMI;

(3) Reduce crosstalk: It is helpful to control the crosstalk problem between signal traces in high-speed digital circuit board reverse engineering. By changing the height of the signal line from the mirror layer, the crosstalk between the signal lines can be controlled. The smaller the height, the smaller the crosstalk;

(4) Impedance control to prevent signal reflection.