Both sides of the Printed Circuit Board have wiring, but to use the two sides of the wire, there must be between the two sides have proper circuit connection. The bridge between such circuits is called the via. The guide hole is a small hole filled or coated with metal on the PCB Board. It can be connected with the wires on both sides. Because the double sided area than a single panel doubled, double panel solves the single panel because of difficult wiring staggered (through the guide hole to the other side), it is more suitable for use in circuit that is more complex than a single panel.