Flexible printed circuit board impedance refers to the parameters of resistance and reactance, which hinder the alternating current. Impedance is often represented by Z, which is a complex number. The real part is called resistance, and the imaginary part is called reactance. The obstructive effect of capacitance on alternating current in the circuit is called capacitive reactance, and the obstructive effect of inductance on alternating current in the circuit is called For inductive reactance, the obstructive effect of capacitance and inductance on alternating current in the circuit is collectively called reactance.
The unit of impedance is ohms. In the FPC circuit board circuit with resistance, inductance, and capacitance, the hindering effect on alternating current is called impedance. FPC circuit board impedance includes characteristic impedance, differential impedance, odd mode impedance, even mode impedance, Common mode impedance. In production, impedance processing is essential.
The Purpose of FPC Impedance
1. It is necessary to consider plugging and installing electronic components. After plugging, the conductivity and signal transmission performance should be considered. Therefore, the lower the impedance, the better, and the resistivity should be lower than 1 ohm:10-6 per square centimeter.
2. In the production process, it has to go through the process and production links, and the materials used in these links must ensure low resistivity in order to ensure that the overall impedance of the circuit board meets the product quality requirements and can operate normally.
- There are various signal transmissions in the conductor. When it is necessary to increase its frequency in order to increase its transmission rate, if the line itself is different due to factors such as etching, laminate thickness, wire width, etc., the impedance value will change and the signal will be distorted. , Resulting in a decrease in the performance of the circuit board, so it is necessary to control the impedance value within a certain range.