Brief analysis of the copper pour on PCB

In electronics, the term copper pour refers to an area on a printed circuit board filled with copper (the metal used to make connections in printed circuit boards). Copper pour is commonly used to create a ground plane. Another reason for using copper pour is to reduce the amount of etching fluid used during manufacturing.

The significance of copper pouring is reduce ground impedance and improve anti-jamming capability, reduce pressure drop and increase power efficiency,can also reduce loop area when connected to ground. Is the copper pour "more beneficial than harm" or "more harm than beneficial"?

As we all know, in high frequency situations, the distribution capacitance of the wiring on the printed circuit board will work. When the length is greater than 1/20 of noise frequency corresponding wavelength, It will produce an antenna effect.The noise will be emitted outward through the wiring. If there is a bad grounding copper pour, copper pour becomes a tool of spreading noise,Therefore, in the high-frequency circuit, must be less than λ/20 spacing, design vias through the wiring. If the copper pour is properly treated, it not only has the power to increase the current, but also plays a double role in shielding interference.

There are generally two basic ways of pouring copper, that is, large area of copper clad and grid copper. Which is better,it’s hard to say.Why?

Large area of copper, with the double function of increasing current and shielding, but if through the wave soldering, the board may be tilted up, even foaming. Therefore, a large area of copper, generally will open several slots, to ease the foaming of copper foil. The pure grid copper pouring is mainly shielding effect, and the effect of increasing the current is reducedFrom the point of view of heat dissipation, the grid has the advantage (it reduces the copper heating surface) and plays a certain role in electromagnetic shielding

In short, high-frequency circuit has a high demand of anti-interference, usually use grid copper, low-frequency circuit has a large current circuit, commonly use full copper pouring.

The copper pouring on the PCB, if the grounding problem is handled well, it is certainly "better than the harm", it can reduce the return area of the signal line, reduce the electromagnetic interference from external signals.