For a simple PCB circuit board, the components are mainly concentrated on one side and the wires are concentrated on the other side. We call this kind of PCB a single-sided board; both sides of the double-sided PCB can be wired, so the wiring area will be larger than that of the single-sided PCB Double the size, and the application is also on more complex circuits.

　　 In order for everyone to understand the advantages of the module circuit board, I have cited the following points:

　　1. Convenient wiring; for high-frequency circuits, add a ground layer to make the signal line form a constant low impedance to the ground.

　　2. The assembly density is high, the volume is small, the connection between the electronic components is shortened, and the signal transmission speed is increased.

　　3. Good shielding effect.

　　Pcb multilayer board is actually made by laminating and bonding several etched single-sided or double-sided boards. The double panel is easy to distinguish. Looking at the light, except for the wiring on both sides, other places are transparent. For the four-layer board and the six-layer board, because the layers in the PCB are very tightly combined, it is not easy to transmit light.