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: A metal hole used to solder the pins of components.

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

Mounting hole: used to fix the circuit board.

Wire: The copper film of the electrical network used to connect the pins of the components.

Connectors: components used to connect between circuit boards.

Filling: Copper coating for ground wire network, which can effectively reduce impedance.

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