We should first determine the corresponding circuit board structure according to the size of the circuit board size and electromagnetic compatibility requirements before designing multilayer PCB. After the structure is determined, the position of the inner layer and the distribution of the signal on each layer are determined as well. Stacked structure is an important factor that affects the performance of EMC, and it is also an important way to suppress electromagnetic interference.
Determine the number of plies
Layer the signal layers according to the special requirements of the signal wiring lines such as differential lines and the type and quantity of sensitive signal lines. Then determine the number of the inner layer depending on the type of power supply, isolation and anti interference.
Considering the arrangement order of circuit board
At this point, it is important to pay attention to the distribution of the special signal layer, the distribution of the source layer and the stratum. The signal layer should be adjacent to the inner layer, and the inner layer and the ground layer should be closely coupled. The high speed signal transmission layer in the circuit is a signal middle layer clamped in the middle of the two inner electric layers. The occurrence of crosstalk the occurrence of crosstalk should be avoided. The grounding impedance can be reduced effectively by the multiple grounding inner electric layers.
Multilayer circuit plate thus obtained can achieve electrical connection according to the plated-through-hole on the circuit board cross section. This board can provide more than two layers for the designers that print the circuit board to laying board, and provides large power supply and grounding area.