Advantages of multi-layer pcb board: high assembly density, small size, light weight Due to high assembly density, the connection between components (including components) is reduced, so it improves reliability;Reduced wiring between components (including components), resulting in improved reliability; The number of wiring layers can be increased, thus increasing the design flexibility; Can form a circuit with a certain impedance; Can form high-speed transmission circuit; The circuit and magnetic circuit shielding layer can be set, and the metal core cooling layer can be set to meet the needs of special functions such as shielding and cooling. Easy installation and high reliability.