The circuit board is mainly composed of pads, vias, mounting holes, wires, components, connectors, filling, electrical boundaries, etc. The main functions of each component are as follows:

Pad: metal hole for soldering component pins.

Vias: There are metal vias and non-metal vias, where metal vias are used to connect component pins between layers.

Mounting hole: used to fix the circuit board.

Wire: Copper film used to connect the electrical network of component pins.

Connector: Components used for connection between circuit boards.

Filling: The copper used for the ground wire network can effectively reduce the impedance.

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