Impedance function of double-sided impedance PCB circuit board

Impedance function of double-sided impedance PCB circuit board

Impedance in PCB double-sided impedance circuit board refers to the parameters of resistance and reactance, which hinder the conduction of alternating current. Impedance value is necessary for some double-sided circuit boards with large current. What are the specific advantages of impedance on line circuit board:

① After the electronic components are connected to the PCB base plate, the electrical conductivity and signal transmission performance should be considered. At this time, the lower the impedance is, the better. ② The manufacturing process of double-sided PCB board needs to go through many processes, such as copper deposition, electrotinning, connector soldering and so on. The materials used in each production process must ensure the resistivity bottom, so as to ensure that the overall impedance of PCB is low enough to meet the product quality requirements and can operate normally.

③ PCB tinning is the most common problem in the production of the entire circuit board, and also the key to affect the impedance. The biggest defects of the chemical tinning layer are easy to change color (easy to oxidize or deliquescence) and poor solderability, which will lead to difficult soldering of the circuit board, high impedance and poor conductivity or instability of the entire board performance. ④ The conductors in the circuit board will have various signal transmission. In order to improve its transmission rate, it is necessary to increase its frequency. If the line itself is different due to etching, stack thickness, wire width and other factors, it is easy to change the impedance value, make its signal distortion, and lead to the degradation of the performance of the circuit board. Therefore, the impedance value must be controlled within a certain range during the manufacturing process.