There are wiring on both sides of Double-Sided Boards. However, to use the wires on both sides, there must be an appropriate circuit connection on both sides. The "bridge" between this circuit is called a guide hole (VIA). The guide hole is a small hole full of metal on PCB, which can be connected to the wires on both sides. Because the area of the double panel is doubled than the single -panel, and because the wiring can be intertwined with each other (it can be around the other side), it is more suitable for more complicated circuits than a single panel. Strictly speaking, double panels are a very important PCB board in the circuit board. His use is very large. Is it easy to watch the PCB board? Make it, the double panel is the extension of one -piece one -piece, which means that the lines of the single -to -surface are not enough to turn to the opposite side. There is also an important feature of the double panel. There is a guide hole. To put it simply, it is double -sided, and there are lines on both sides! A summary is: the panel of double -sided wiring is double panel! Some friends are about to ask for a two -sided lane, but only one side has electronic parts. Is this board double panel or single -eyed? The answer is obvious. Such a board is a double panel, but it is just a part on the double panel.