1 Overview Multilayer printed boards are designed for better electromagnetic compatibility. The printed board can meet electromagnetic compatibility and sensitivity standards during normal operation. Proper stacking helps shield and suppress EMI. 2. The basis of multi-layer printed board design. The electromagnetic compatibility analysis of multilayer printed boards can be based on Kirchhoff's law and Faraday's law of electromagnetic induction. According to Kirchhoff's law, any time domain signal must have a path of lowest impedance from source to load. See Figure 1. In the figure, I=I', the size is equal, and the direction is opposite. In the figure, I call the signal current, I' is called the map current, and the layer where I' is called the image plane layer. If the signal current is below the power plane (POWER), the image current loop at this point is achieved by capacitive coupling. See Figure 2. Based on the above two laws, we conclude that the following basic principles should be followed in the delamination and stacking of multilayer printed boards: 1 The power plane should be as close as possible to the ground plane and should be below the ground plane. 2 The wiring layer should be arranged adjacent to the image plane layer. 3 Power and formation impedance are lowest. 4 A strip line is formed in the middle layer, and a microstrip line is formed on the surface. The characteristics of the two are different. 5 Important signal lines should be close to the ground. 3. Stacking and delamination of PCB boards 1 two-layer board. This board can only be used in low speed designs. EMC is relatively poor. 2 four-layer board. In short, the layering and lamination of PCBs is a complicated matter. There are many factors to consider. But we should remember the features we have to accomplish and the key factors that are needed. In this way, we can find a layer and laminate of printed boards that meet our requirements. IGET VAPE PEN, WHOLESALE IGET, IGET MANUFACTURER Shenzhen Xcool Vapor Technology Co.,Ltd , https://www.szxcoolvapor.com
