As PCB manufacturer China knows that, Via is one of the important components of multilayer PCBs. The copper foil circuit in different layers of the circuit board is connected by this kind of hole. 

In the printed circuit board (PCB) production process, drilling is essential. The simple understanding of drilling is to drill the required vias on the copper clad board, which provides electrical connections and fixing devices. If the operation is not correct, the process of via holes will be problematic. The device cannot be set on the circuit board, which will affect the circuit board’s use, and in the worst case, the entire panel will be scrapped. Therefore, the drilling process is essential.