Impedance PCB refers to a PCB board that requires impedance control. Impedance PCB control means that under high-frequency signals, the "resistance" generated by a certain line layer to its reference layer during transmission must be controlled within the rated range to ensure that the signal is not distorted during transmission. PCB impedance control is to ensure that every part of the system has the same impedance value, that is, impedance matching. So, what are the factors related to impedance PCB?
From the perspective of PCB manufacturing, the main factors and key factors that affect the impedance of PCB are as follows:
1.The impedance of PCB becomes smaller (W.
2. As the distance (s) increases, the impedance increases.
3. As the wire thickness (T) increases, the impedance decreases.
4. The media thickness (H) of the PCB board. The greater the media thickness, the greater the impedance.
5. Dielectric constant (DK) of the PCB board. The greater the dielectric constant, the smaller the impedance.
Note: In fact, the solder mask layer of the PCB will also affect the impedance, but because the solder mask layer is attached to the dielectric, the dielectric constant will increase. This is due to the influence of the dielectric constant, and the PCB impedance value will decrease by 4%.