With the continuous innovation of electronic technology and the continuous improvement of the requirements for electronic equipment in some industries such as computers, medical treatment, and aviation, printed circuit boards are developing in the direction of smaller volume, lighter weight, and increased density. Single and double-sided printed boards can no longer meet the demand, so it is necessary to consider using more layers and higher assembly density multilayer circuit boards.
What is a multilayer circuit board?
In daily life, multilayer PCB circuit boards are currently the most widely used circuit board type. Multilayer PCB are circuit boards composed of two or more conductive layers (copper layers) superimposed on each other. The most common is four Six-layer board, such as the familiar computers in our daily life. Single-layer and double-layer boards are easy to distinguish and can be distinguished with the naked eye. Hold the board and look at the light. Except for the wiring on both sides, the rest of the place is transparent . But for multilayer PCB boards with four-layer boards and six-layer boards, if there is no corresponding mark on the board, it is not so easy to distinguish. Generally, the requirements for the structure design and process production of multilayer electric boards are very high, and the higher the number of layers, the more difficult it is, and it is suitable for use in more complex circuits.

Application advantages of multilayer PCB circuit boards:
1. High assembly density, small size and light weight, meeting the needs of light and miniaturization of electronic equipment;
2. Due to the high assembly density, the wiring between each component (including components) is reduced, the installation is simple, and the reliability is high;
3. Due to the repeatability and consistency of the graphics, the errors in wiring and assembly are reduced, and the maintenance, debugging and inspection time of the equipment is saved;
4. Flexible design, larger wiring space;
5. It can form a circuit with a certain impedance and can form a high-speed transmission circuit;
6. Circuit, magnetic circuit shielding layer can be set, and metal core heat dissipation layer can be set to meet the needs of special functions such as shielding and heat dissipation.