The need to consider more factors to determine the stacking structure of multilayer PCB board. From the wiring, the more the number of layers is conducive to wiring, but the board cost and difficulty will be increased. For manufacturers, the laminated structure is symmetrical or not is the focus of attention of the PCB plate manufacturing, so the choice of layers need to consider all aspects of the demand, in order to achieve the best balance.
For experienced designers, after the completion of the layout of the components, the PCB will be the bottleneck of the wiring analysis. The wiring density in combination with other EDA tools to analyze the circuit board; the number and variety of comprehensive special wiring required signal line such as differential and sensitive signal line to determine the signal layer number; then according to the type of power supply, isolation and anti-jamming requirements to determine the number of the inner layer. In this way, the number of the board layer of the whole circuit board is basically determined.