The double-sided PCB (double-layer/double-sided printed circuit board/breadboard) is more complicated than single sided PCB. The circuits on both sides are connected through the middle Various types of double-sided PCB are on the market, such as double sided copper clad PCB, high Tg thick copper foil PCB, high-frequency PCB, and hybrid dielectric base high-frequency double-sided PCB. Double-sided PCBs are widely used in high-tech industries like telecommunications, power supply, computers, industrial control, digital products, scientific and educational equipment, medical equipment, automobiles, aerospace defense.

There are conductive patterns on both sides of the insulating substrate, generally using metallization holes to connect the conductive patterns on both sides cause both sides have conductive patterns, such PCBs can be used through metal holes to wrap the wiring to the other side and interleaved with each other, so it can be used on more complex circuits.