About PCB ground

lym1210

About PCB ground [Copy link]

Hello, seniors. I just started learning PCB and I have always had a question that I don't understand, that is, how are all the grounds on the PCB board connected to each other? If only wires are used, then the ground wires will be very long, because there are too many pins that need to be grounded. I saw some people put some through-hole pads or vias (I don't understand this either) as grounding (for example, the ground end of a surface-mount capacitor). How are these vias or pads connected to other grounds? Is it through copper plating? If these through-hole pads or vias are used, why can't they be seen on the finished board?

Arvinˇ

First, use the wire to pass through, and add vias when necessary for the double-layer board. There is no need to add any vias at all ground ends. (Of course, some heat-generating parts can add some vias at the ground end to increase the heat dissipation performance, and some applications with relatively large currents can add more vias for shunting.) Copper is applied on the top and bottom layers, and the copper-clad network is set to ground. Finally, some vias are evenly added in the copper-clad area to connect the upper and lower ground layers to increase the anti-interference ability of the entire board. As shown in Figure 1: The highlighted part is to connect the ground network with wires first, and then apply copper, which will be more beautiful. As for the invisible vias you mentioned, you can choose (cover with oil/open window) in the via setting, as shown in the red box in Figure 2. Check the cover with oil, the effect is shown in Figure 3; do not check the open window, the effect is shown in Figure 4.

qwqwqw2088

When laying out the board, you can connect other traces first, and lay the ground last. You can put vias, and then lay copper with the ground network.

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