In the design of high-speed PCB, the seemingly simple via hole will bring great negative effect to the circuit design.In order to reduce the adverse effect caused by parasitic effect of overhole, we can do as much as possible in the design of PCB sample making superior customer boards:
1.Considering the cost and signal quality, we choose the reasonable size of hole.If necessary, consider using holes of different sizes. For example, for power supply or ground wire, consider using larger sizes to reduce impedance, while for signal routing, use smaller holes.Of course, as the size of the via hole decreases, the corresponding cost will increase.
2.The two formulae discussed above show that the use of a thinner PCB plate is beneficial to reduce the two parasitic parameters of the via hole.
3.The signal on the PCB board should not be changed as far as possible, that is to say, do not use unnecessary holes.
4.The closer the hole is to be punched between the power supply and the ground pin, the shorter the lead is, the better.The equivalent inductance can be reduced by making multiple through-holes in parallel.
5.Place some earthed passes near the transposition of the signal to provide the closest loop for the signal.You can even put some extra grounding holes in the PCB.
6.For high density high speed PCB board, you can consider using micro via hole