The working principle of a circuit board is to use board based insulation materials to isolate the surface copper foil conductive layer, allowing current to flow along a pre designed route in various components to complete functions such as work, amplification, attenuation, modulation, demodulation, encoding, etc.

　　The circuit board mainly consists of solder pads, vias, mounting holes, wires, components, connectors, thin film circuit SMT patches for Watford circuit boards, SMT patches for thin film circuit SMT patches, fillers, electrical boundaries, etc. The main functions of each component are as follows:

　　Solder pad: A metal hole used for soldering component pins.

　　Through hole: There are metal through holes and non-metal through holes, where metal through holes are used to connect component pins between layers.

　　Installation hole: used to fix the circuit board.

　　Wire: An electrical network copper film used to connect component pins.

　　Connector: A component used for connecting circuit boards.

　　Filling: Copper coating used for ground wire networks can effectively reduce impedance.

　　Electrical boundary: used to determine the size of a circuit board, and all components on the circuit board must not exceed this boundary.