The circuit board determines the process difficulty and processing price according to the number of wiring surfaces. Common circuit boards are divided into single-sided wiring and double-sided wiring, commonly known as single-sided and double-sided. However, electronic products are restricted due to product space design factors, except for surface In addition to wiring, multi-layer circuits can be superimposed inside. In the production process, after each layer of wiring is made, it is positioned and pressed by optical equipment, so that the multi-layer circuits are superimposed on a circuit board. Commonly known as multilayer circuit boards. Any circuit board with more than or equal to 2 layers can be called a multilayer circuit board. Multilayer circuit boards can be divided into multilayer rigid circuit boards, multilayer flexible and rigid circuit boards, and multilayer flexible and rigid circuit boards.

According to the number of layers, circuit boards are divided into three major categories: single-sided, double-sided, and multi-layer circuit boards.

The first is a single-sided board. On a 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 kind of PCB is called a single-sided circuit board. Single-sided panels are usually simple to produce and low in cost, but the disadvantage is that they cannot be applied to products that are too complex.

Double-sided boards are an extension of single-sided boards. When single-layer wiring cannot meet the needs of electronic products, double-sided boards should be used. There are copper-clad wires on both sides, and the lines between the two layers can be connected through vias to form the required network connections.

Multi-layer board refers to a printed board with more than three conductive pattern layers and insulating material between them laminated at intervals, and the conductive patterns between them are interconnected as required. Multilayer circuit boards are the product of the development of electronic information technology in the direction of high speed, multi-function, large capacity, small volume, thinner and lighter weight. Circuit boards are divided into flexible boards (FPC), rigid boards (PCB), and rigid-flex boards (FPCB) according to their characteristics.