Advantages and disadvantages of using paved copper and network copper for PCB
PCB manufacturers, PCB designers and PCBA manufacturers explain the advantages and disadvantages of using paved copper and network copper for PCB
Printed circuit boards, also known as Printed circuit boards, are providers of electrical connections for electronic components.
Printed circuit board is usually represented by "PCB", not "PCB".
PCB design is mainly layout design; The main advantage of using circuit board is to greatly reduce wiring and assembly errors, and improve the automation level and production labor rate.
The so-called copper coating refers to taking the idle space on the flexible circuit board as the reference plane, and then filling 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 capability; Reduce voltage drop and improve power efficiency; Connecting with the ground wire can also reduce the loop area. In order to keep PCB from deforming as much as possible during welding, most PCB manufacturers also require PCB designers to fill the open area of PCB with copper sheet or grid shaped ground wire. If copper coating is handled improperly, it will be rewarded or lost. Is copper coating "more beneficial than harmful" or "more harmful than beneficial"?
As we all know, the distributed capacitance of the wiring on the printed circuit board will play a role in high frequency. When the length is greater than 1/20 of the corresponding wavelength of the noise frequency, the antenna effect will be generated, and the noise will be emitted through the wiring. If there is a poorly grounded copper coating in the PCB, the copper coating will become a tool to spread the noise. Therefore, in high frequency circuits, do not think that the ground wire is grounded somewhere, This is the "ground wire", which must be less than λ/ 20, make holes on the wiring, and "well grounded" with the ground plane of the multilayer board. If the copper coating is properly treated, it not only increases the current, but also plays a dual role in shielding interference.
Generally, there are two basic methods of copper cladding, namely, large-area copper cladding and grid copper cladding. It is often asked whether large-area copper cladding or grid copper cladding is better. Why? Large area copper coating has the dual functions of increasing current and shielding. However, if large area copper coating is used for wave soldering, the board may be warped or even blistered. Therefore, for a large area of copper coating, several grooves are usually opened to alleviate the blistering of copper foil. The simple grid copper coating is mainly used for shielding, and the effect of increasing current is reduced. From the perspective of heat dissipation, the grid is beneficial (it reduces the heating surface of copper) and plays a certain role in electromagnetic shielding.
It needs to be pointed out that the grid is composed of lines in staggered directions. We know that for circuits, The width of the wiring has its corresponding "electrical length" for the operating frequency of the circuit board (the actual size is divided by the digital frequency corresponding to the operating frequency, see the relevant books for details) When the working frequency is not very high, perhaps the role of grid lines is not very obvious. Once the electrical length matches the working frequency, it is very bad. You will find that the circuit does not work properly at all, and there are signals everywhere that interfere with the work of the system. Therefore, for colleagues who use grid, my suggestion is to choose according to the working conditions of the designed circuit board, instead of holding on to something. Therefore, high-frequency circuit requires high anti-interference multi-purpose grid, and low-frequency circuit has high current circuit and other commonly used complete copper coating. PCB manufacturers, PCB designers, and PCBA manufacturers will explain the advantages and disadvantages of using paved copper and network copper for PCB.