In a circuit with resistance, inductance, and capacitance, the hindrance to alternating current is called impedance. In the production of pcb circuit boards, impedance processing is essential. The reasons are as follows:
1. The PCB circuit (bottom of the board) should consider plugging and installing electronic components, and considering issues such as conductivity and signal transmission performance after plugging, so the lower the impedance, the better.
2. During the production process of PCB circuit boards, they have to go through processes such as copper sinking, tin plating (or chemical plating, or thermal spray tin), and connector soldering. The materials used in these links must ensure that the resistivity is low to ensure The overall impedance of the circuit board is low to meet product quality requirements and can operate normally.
3. The tinning of PCB circuit boards is the most prone to problems in the entire circuit board production, and it is a key link that affects impedance. The biggest defect of electroless tin coating is easy discoloration (both easy to be oxidized or deliquescent) and poor solderability, which will lead to difficult soldering of circuit boards, high impedance, poor electrical conductivity, or unstable overall board performance.
