Track is provided on both sides of double-sided PCB. However, to use tracks on both sides, there must be a proper circuit connection between the two sides. This "bridge" between circuits is called a via. The guide hole is a small hole filled or coated with metal in the PCB, which can be connected with the tracks on both sides.

    Double-sided PCB is a printed circuit board with copper coated on both sides including top and bottom. It is the most common circuit board. Both sides of its insulating substrate have conductive graphics, and the electrical connections on both sides are mainly connected through vias or pads. Because both sides can be wired, which greatly reduces the difficulty of wiring, it is widely used.

   Because the area of the double-sided board is twice as large as that of the single panel, the double-sided pcb solves the difficulty of staggered wiring in the single panel (it can be connected to the other side through holes), and it is more suitable for more complex circuits than the single panel.

   The manufacturing method of double-sided PCB  board is generally made by inner layer graphics, and then made into single-sided or double-sided substrate by printing etching method, which is incorporated into the specified interlayer, and then heated, pressurized and bonded. The subsequent drilling is the same as the plating through-hole method of double-sided board. These basic manufacturing methods have not changed much from the construction methods dating back to the 1960s. However, with the maturity of materials and process technologies (such as press bonding technology, solving the rubber slag generated during drilling, and the improvement of film), the characteristics attached to multi-layer plates are more diversified.

The production of double-sided panel is more complicated than that of single panel. The main reasons are as follows:

(1) The top and bottom layers of copper clad plate shall be wired.

(2) The tracks on the top and bottom layers shall be connected with metallized vias.