Before designing multi-layer PCB, the designer needs to first determine the circuit board structure according to the scale of the circuit, the size of the circuit board and the requirements of electromagnetic compatibility (EMC), that is, decide whether to use 4-layer, 6-layer or more layers of PCB. After determining the number of layers, determine the placement position of the internal electrical layer and how to distribute different signals on these layers. This is the choice of Multilayer PCB laminated structure.
Laminated structure is an important factor affecting the EMC performance of PCB, and it is also an important means to suppress electromagnetic interference. This section will introduce the related contents of Multilayer PCB laminated structure. The selection of the number of layers and the principle of superposition} many factors need to be considered to determine the laminated structure of multi-layer PCB. In terms of wiring, the more layers, the better the wiring, but the cost and difficulty of board making will also increase. For manufacturers, whether the laminated structure is symmetrical or not is the focus of attention in PCB manufacturing, so the selection of layers needs to consider the needs of all aspects to achieve Zui good balance. For experienced designers, after completing the pre layout of components, they will focus on the analysis of the wiring bottleneck of PCB.
Zui then combined with other EDA tools to analyze the wiring density of the circuit board; Then the number and type of signal lines with special wiring requirements, such as differential lines and sensitive signal lines, are integrated to determine the number of signal layers; Then the number of internal electric layers is determined according to the type of power supply, isolation and anti-interference requirements. In this way, the number of layers of the whole circuit board is basically determined.