Why do PCBs have a large area of copper?


PCB circuit boards can be seen everywhere in various application appliances and instruments. The reliability of the circuit board is an important guarantee to ensure the normal operation of various functions. However, on many circuit boards, we often see many of them are large areas of copper, designing circuit boards. Large areas of copper are used.

Generally speaking, large area copper has two functions. One is for heat dissipation. Because the circuit board current is too large, the power rises. Therefore, in addition to adding the necessary heat dissipation components, such as heat sinks, heat dissipation fans, etc., but for some circuit boards, It is not enough to rely on these. If it is only for heat dissipation, it is necessary to increase the soldering layer while increasing the copper foil area, and add tin to enhance heat dissipation.

 

It is worth noting that due to the large area of copper clad, the PCB or copper foil adhesion will be reduced due to long-term wave crest or long-term heating of the PCB, and the volatile gas accumulated in it cannot be exhausted over time. The copper foil expands and falls off, so if the copper area is very large, you should consider whether there is such a problem, especially when the temperature is relatively high, you can open it or design it as a grid mesh.

The other is to enhance the anti-interference ability of the circuit. Due to the large area of copper can reduce the impedance of the ground wire and shield the signal to reduce mutual interference, especially for some high-speed PCB boards, in addition to thickening the ground wire as much as possible, the circuit board is necessary. Ground all free places, that is, “full ground”, which can effectively reduce parasitic inductance, and at the same time, a large area of ground can effectively reduce noise radiation. For example, for some touch chip circuits, each button is covered with a ground wire, which reduces the anti-interference ability.