The manufacturing method of multi-layer circuit boards generally starts with the inner layer pattern, and then uses the printing and etching method to make a single-sided or double-sided substrate, and incorporates it into the designated interlayer, and then heats, presses and bonds it. As for the subsequent Drilling is the same as the plated through-hole method of the double-sided board. These basic production methods have not changed much from the construction methods dating back to the 1960s, but as materials and process technologies become more mature, the characteristics of the attached multilayer boards become more diverse.

　　 Advantages of multilayer circuit boards:

　　1. High-speed transmission circuit can be formed, simple installation and high reliability;

　　2. High assembly density, small size and light weight;

　　3. The number of wiring layers can be increased, thereby increasing design flexibility;

　　 4. It can form a circuit with some impedance;

　　 5. Due to the high assembly density, the wiring between components (including components) is reduced, thereby improving reliability;

　　6. Circuit, magnetic circuit shielding layer can be set, and metal core heat dissipation layer can also be set to meet the needs of special functions such as shielding and heat dissipation.

　　 Multi-layer printed circuit refers to a printed circuit composed of more than three layers of conductive patterns, separated by layers of insulating materials, laminated and bonded. The conductive patterns between the layers are interconnected as required. At present, multilayer circuit boards have been widely used in various electronic devices and have become an important part of electronic components.