Multilayer circuit boards are generally used in high-speed PCB design. Multilayer circuit boards are actually laminated and bonded from several etched single or double sided boards. Multilayer circuit boards have many advantages compared with single or double layered circuit boards. Especially in small electronic products, let's share the advantages of multilayer circuit boards.

1. Multilayer circuit boards have high assembly density and small volume. With the smaller and smaller volume of electronic products, higher requirements are put forward for the electrical performance of PCB, and the demand for multilayer circuit boards is also growing.

2. The use of multi-layer circuit boards facilitates wiring, greatly shortens the wiring length and shortens the wiring between electronic components, which also improves the speed of signal transmission.

3. For high-frequency circuit, after adding the ground layer, the signal line will form a constant low impedance to the ground, the circuit impedance will be greatly reduced, and the shielding effect is good.

4. For electronic products with high heat dissipation requirements, multi-layer circuit boards can be equipped with metal core heat dissipation layer, which is convenient to meet the needs of shielding, heat dissipation and other special functions.

In terms of performance, multilayer circuit boards are superior to single and double sided boards, but the higher the number of layers, the higher the production cost, the longer the processing time, and the more complex the quality inspection. However, under the cost comparison of the same area, although the cost of multi-layer circuit boards is higher than that of single and double layers, the cost difference between the two is not so obvious when the noise reduction light factor is included in the scope of consideration. With technological progress, there are more than 100 layers of PCB boards, which are mostly used in precision aerospace instruments and medical equipment.

In multilayer circuit boards, the Zui board is mostly composed of four or six layers. In daily life, we are familiar with computers. The difference between the four layer board and the six layer board lies in the middle layer. There are two more internal signal layers between the ground wire layer and the power supply layer. The six layer board is thicker than the four layer board. It is easy to distinguish the single and double layers of boards with the naked eye. Hold the board and look at the light. Except for the wiring on both sides, the rest of the places are transparent. However, for the four layer board and the six layer board, if there is no corresponding mark on the board, it is not so easy to make a simple distinction.

In general, multilayer circuit boards have been widely used in the production of electronic products due to their design flexibility, economic superiority, electrical stability and reliability.