The so-called copper cladding is to take the idle space on the flexible circuit board as the reference plane, and then fill it with solid copper. These copper areas are also called copper filling.The significance of copper coating is to reduce the ground wire impedance and improve the anti-interference ability;Reduce voltage drop and improve power efficiency;Connecting with the ground wire can also reduce the loop area.For the purpose of keeping the PCB from deformation as much as possible, most PCB manufacturers also require PCB designers to fill the open area of PCB with copper sheet or grid like ground wire. If the copper coating is handled improperly, it will not be rewarded. Is copper coating “more beneficial than harmful” or “more harmful than beneficial”?
In the case of high-frequency wiring, the noise will be transmitted out of the PCB when the circuit is connected to the ground, and the noise will be transmitted out of the PCB when the circuit is grounded,If the ground wire is grounded at a certain place, it is called “ground wire”λ/20, through holes in the wiring, and “well grounded” to the ground plane of the multilayer board.If the copper coating is properly treated, it can not only increase the current, but also play a dual role in shielding interference.
There are two basic ways to copper clad flexible circuit board, namely, large area copper coating and grid copper coating. It is often asked whether large area copper coating is better or grid copper coating, which is not easy to generalize.Why?Large area copper coating has the dual functions of increasing current and shielding. However, if the large area of copper coating is over wave soldering, the board may be warped and even blistered.Therefore, for large area copper coating, several slots will be opened to alleviate blistering of copper foil. The pure grid copper coating mainly has shielding effect, and the effect of increasing current is reduced. From the perspective of heat dissipation, grid is beneficial (it reduces the heating surface of copper) and plays a certain role in electromagnetic shielding.
But it should be pointed out that the grid is made up of lines in staggered directions. We know that for circuits,The width of the circuit board has its corresponding “electrical length” for the working frequency of the circuit board (the actual size can be obtained by dividing the digital frequency corresponding to the working frequency, see relevant books for details)When the working frequency is not very high, perhaps the effect of gridlines is not very obvious. Once the electrical length and working frequency match, it will be very bad. You will find that the circuit can not work normally at all, and the signals interfering with the system are being transmitted everywhere.Therefore, for the colleagues who use the grid, my suggestion is to choose according to the working conditions of the designed circuit board. Do not cling to a thing.Therefore, the high frequency circuit anti-interference requires multi-purpose grid, low-frequency circuit with high current circuit and other commonly used complete copper.
