If circuit boards are classified according to the number of layers, they can be divided into three major categories: single panel, double-sided board, and multi-layer circuit board.

Firstly, there is a single panel. In the most basic PCB, the parts are concentrated on one side and the wires are concentrated on the other side. Because the wires only appear on one side, this type of PCB is called a single-sided circuit board. Single panel production is usually simple and cost-effective, but the disadvantage is that it cannot be applied to overly complex products.

Double panel is an extension of a single panel. When single-layer wiring cannot meet the needs of electronic products, double-sided panels are used. Both sides are covered with copper and have wiring, and the wires between the two layers can be connected through vias to form the required network connection.

Multilayer board refers to a printed circuit board consisting of three or more layers of conductive graphics and insulating materials separated by layers, with conductive graphics interconnected as required. Multilayer circuit board is a product of the development of electronic information technology towards high speed, multifunctionality, large capacity, small volume, thinness, and lightweighting.

If circuit boards are classified according to their characteristics, they can be divided into soft boards (FPC), hard boards (PCB), and combination of soft and hard boards (FPCB)