Why Lay Copper On PCB?

There are several reasons for laying copper in PCB.

1. EMC. For large areas of ground or copper power supply, it will play a shielding role, and some special grounds, such as PGND, will play a protective role.

2. PCB process requirements. Generally, in order to ensure the plating effect, or the laminate is not deformed, copper is laid on the PCB layer with less wiring.

3. Signal integrity requirements, give high-frequency digital signals a complete return path, and reduce the wiring of the DC network. Of course, there are reasons for heat dissipation, copper installation for special devices and other reasons.

One of the major benefits 

Copper laying is the reduction of ground impedance. There are a lot of spike currents in digital circuits, so it seems more necessary to reduce the ground impedance.

Second, the significance of laying copper on the circuit lies in:

1. Connect copper and ground wire to reduce loop area

2. A large area of copper is equivalent to reducing the resistance of the ground wire and reducing the voltage drop. From these two points, whether it is digital ground or analog ground, copper should be laid to increase the anti-interference ability, and at high When the frequency is high, the digital ground and the analog ground should be separated to lay copper, and then connected with a single point. The single point can be wrapped around a magnetic ring with a wire for a few turns, and then connected.