As PCB supplier china knows that, the common sense impedance control is a force and position dependent physical dynamic control method. It defines the motion that force produces. The impedance control in the printed circuit board expresses the control of the circuit board trace width and height, dielectric materials and other production process factors on the circuit signal propagation.

Impedance measures the impedance of a circuit when alternating current is applied. It is a combination of capacitance and induction in a PCB circuit. Impedance affects how signals travel through the board, how power is transferred between components, and how signals flow into unwanted areas of the PCB. Impedance may vary with operating frequency. The impedance formula is usually represented by Z = R – j/ωC + jωL, where ω = 2πf. Transmission is optimal when a signal is passed from a conductor with a given impedance to another conductor with the same impedance. On the other hand, if the impedances are different, reflections and attenuations that degrade the signal will occur.