The Printed circuit board can be regarded as a miniature carrier platform and an important carrier of integrated circuits. The emergence of PCB multilayer boards allows the limited space to accommodate as many more complex circuits as possible. In addition, it also simplifies the layout difficulty of the circuits on the PCB to a certain extent. Many friends think: The more PCB layers, the better the performance. Is this true?
At present, the most common multilayer pcb on the market are four or six layers. The higher the precision of the product, the higher the number of layers of the circuit board. Like aerospace equipment, it is not surprising that the number of PCB layers is up to several hundred layers.
The greater the number of circuit board layers, the higher the wiring difficulty index, so the manufacturing cost is relatively high. However, this does not mean that the performance of the high-level circuit board is higher than that of the low-level PCB. The high-level PCB is just to allow the electronic circuit to obtain more wiring space and ensure that the subtle wiring can also have an optimal layout. The higher the number of PCB layers, the lower the electromagnetic interference between the layers, thereby reducing the interference between the signals and extending the service life of the PCB.
The performance of the circuit board cannot be equated with the number of layers. The simple four or six-layer PCB also has excellent performance. In fact, the number of circuit board layers is only a rigid requirement in the design of the circuit board, and is not used as a standard for judging the quality of the PCB.
Since the circuit board is mainly composed of raw materials such as woven fiber cloth, resin and copper foil, and the material itself has a certain thickness, the higher the number of layers of the multilayer pcb board, the more layers of these raw materials are stacked. To a certain extent, multilayer pcb have stronger rigidity than single-layer and double-layer boards.
Due to the different technical capabilities of each circuit board factory, the total number of components that can be reasonably accommodated on each floor is also different. In theory, within a reasonable range, the placement of 100 components on a layer of circuit boards and the placement of them on two layers of PCB circuit boards are no different. It is just because the volume requirements of electronic products are getting smaller and smaller, which requires that the design space becomes smaller and the size of the circuit board is getting smaller and smaller under the same performance situation.
Therefore, to sum up, the higher the number of layers of the multilayer pcb board does not mean the better the performance. It should be designed in accordance with its own use requirements.