Should dead copper be removed in PCB design?

First, we don't want to die copper (island), because the island here forms an antenna effect, if the radiation intensity of the surrounding line is high, it will enhance the radiation intensity of the surrounding; And will form the antenna acceptance effect, will introduce electromagnetic interference to the surrounding lines.

Second, we can delete some small islands. If we wish to retain the copper cladding, the island should be well connected to GND through the ground hole to form a shield.

Third, at high frequencies, the distributed capacitance of the wiring on the printed circuit board will come into play, and when the length is greater than 1/20 of the wavelength corresponding to the noise frequency, an antenna effect will occur and noise will be emitted outward through the wiring. If there is a poorly grounded copper-covering line in the PCB, the copper-covering becomes a noise transmission tool.

Therefore, in the high frequency circuit, do not think that the ground ground somewhere, this is the "ground wire", must be less than λ/20 spacing, in the wiring through the hole, and the ground plane of the multilayer "good grounding". If the copper coating is properly treated, the copper coating not only increases the current, but also plays the dual role of shielding interference.

Fourthly, by punching the ground hole and retaining the copper covering of the island, it can not only play the role of shielding interference, but also prevent PCB deformation. Source network