Circuit boards are mainly composed of pads, over holes, mounting holes, wires, components, connectors, filler, electrical boundaries and so on.
Solder pads: metal holes for soldering component pins.
Perforations: metal perforations and non-metallic perforations, of which the metal perforations are used to connect the component pins between the layers.
Mounting holes: used to secure the board.
Wires: The electrical network of copper film used to connect the component pins.
Connector: used to connect components between circuit boards.
Filling: copper laying for ground networks, which can effectively reduce impedance.
Electrical boundary: used to determine the size of the board, all components on the board can not exceed the boundary.
Expanded Information
The circuit board includes many types of working layers, such as signal layer, protective layer, silkscreen layer, internal layer, etc. The role of the various layers is briefly described as follows:
1. Signal Layer: Mainly used for placing components or wiring.Protel DXP usually contains 30 intermediate layers, namely Mid Layer1~Mid Layer30, the middle layer is used to arrange the signal line, the top layer and the bottom layer is used to place components or copper.
2. Protective Layers: Mainly used to ensure that the circuit board does not need to be tinned places are not tinned, so as to ensure the reliability of the circuit board operation. Among them, Top Paste and Bottom Paste are respectively the top and bottom soldermask layers; Top Solder and Bottom Solder are respectively the solder paste protection layer and the bottom solder paste protection layer.
3, silkscreen layer: mainly used in the circuit board printed on the components of the running number, production number, company name, and so on.
4, the internal layer: mainly used as a signal wiring layer, Protel DXP **** contains 16 internal layer.
5, other layers: mainly includes four types of layers.
Drill Guide (Drill Orientation Layer): Mainly used for the location of drilled holes on the printed circuit board.
Keep-Out Layer (prohibit wiring layer): mainly used to draw the electrical border of the circuit board.
Drill Drawing: Used to set the shape of the drill holes.
Multi-Layer: Mainly used to set up multiple layers.