Personal Talk about PCB Copper Clad Experience

Personal Talk about PCB Copper Clad Experience

The so-called copper cladding is to use the idle space on the PCB as a reference plane and then fill it with solid copper. These copper areas are also called copper filling. The significance of copper plating is to reduce the impedance of the ground wire and improve the anti-interference ability; reduce the voltage drop and improve the efficiency of the power source; If there are many grounds on the PCB, such as SGND, AGND, GND, etc. My approach is that, depending on the position of the PCB board, the most important "ground" is used as the reference for independent copper clad, and the digital and analog grounds are separated by copper. At the same time, before copper-cladding, first thicken the corresponding power connections: V5.0V, V3.6V, V3.3V, etc. In this way, a plurality of differently deformed structures are formed.

There are several problems that need to be dealt with in copper clad. First, single-point connection at different grounds. The method is to connect through 0 ohm resistors or magnetic beads or inductors. Second, copper clad near the crystal oscillator. Lay copper around the crystal and ground the crystal case separately. The third is the isolated island (dead zone) problem. If you think it is too big, then it will not take much to define a land via to add it.

In addition, large-area copper is better than grid copper, which is not general. why? Large-area copper, if the wave soldering is over, the board may be lifted up and even blister. From this point, the heat dissipation of the grid is better. It is usually a multi-purpose grid with high-frequency circuits that require high resistance to interference, and low-frequency circuits with large currents. However, a hero once told me that when doing signals above 1GHz, impedance must be matched, and the reflective surface must be fully copper-clad!

Personal experience: When starting the wiring, the ground wire should be treated equally. When the wire is routed, the ground wire should be routed properly. You cannot rely on copper through adding vias to eliminate the ground pins for connection. This effect is very bad. . Of course, if grid copper is used, these ground connections will have some impact on the aesthetics. If they are careful, delete them.

Finally, sum up the benefits of copper clad: improve power efficiency, reduce high frequency interference, and the other is that it looks beautiful!