China Wholesale Order Printed Circuit Board Factories - 6 Layer ENIG Impedance Control PCB 7736 – Huihe

Why PCB to do impedance?

PCB impedance refers to the resistance and the parameters of the reactance, which acts as a barrier to the alternating current. Impedance processing is essential in PCB. Here’s why:

1, PCB to consider the plug installation of electronic components, SMT patch plug also needs to consider the conductivity and signal transmission performance, so it will require the lower the impedance, the better.

2, PCB in the production process through copper deposition, electroplating tin (or electroless plating, hot spray tin), connector soldering and other processes, the materials used must be low resistivity, to ensure that the overall impedance value of the circuit board to meet the product quality requirements, in order to normal operation.

3, PCB tin plating is the most prone to problems in the whole PCB production, is the key link affecting the impedance; Its biggest defect is easy oxidation or deliquesce, poor brazing, so that the PCB is difficult to weld, impedance is too high, resulting in poor conductive performance or the whole PCB performance is not stable.

4, the conductor in the PCB will have a variety of signal transmission, the line itself due to etching, lamination thickness, wire width and other factors, will cause the impedance value changes, make the signal distortion, resulting in the performance of the circuit board decline, so it is necessary to control the impedance value within a certain range.