How do you identify circuit board components?
The circuit board is mainly composed of pad, through hole, mounting hole, wire, components, connectors, filling, electrical boundary and so on.
Pad: Metal hole used to weld pins of components.
Perforation: there are metal perforation and non-metal perforation, among which the metal perforation is used to connect the pins of components between layers.
Mounting hole: Used to fix the circuit board.
Wire: Copper film of electrical network used to connect component pins.
Connectors: Components used to connect circuit boards.
Filling: Used for copper coating of ground wire network, which can effectively reduce impedance.
Electrical boundary: Used to determine the dimension of the board beyond which all components on the board must not exceed this boundary.
Circuit board includes many types of working layer, such as signal layer, protective layer, screen printing layer, internal layer, etc., the role of various layers is briefly introduced 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 lay signal cables, and the top and bottom layers are used to place components or copper coating.
2, protective layer: mainly used to ensure that the circuit board does not need tin plating place is not tin plating, so as to ensure the reliability of the circuit board operation. Top Paste and Bottom Paste are the Top welding layer and the Bottom welding layer respectively. Top Solder and Bottom Solder are the Solder paste protection layer and the underlying Solder paste protection layer respectively.
3, screen printing layer: mainly used to print on the circuit board components serial number, production number, company name, etc.
4. Internal layer: mainly used as signal wiring layer, Protel DXP contains 16 internal layers.
5. Other Layers: There are 4 types of layers.
Drill Guide: Mainly used for Drill positions on printed circuit boards.
Keep-out Layer: Mainly used to draw the electrical border of the circuit board.
Drill Drawing: mainly used for setting Drill shape.
Multi-layer: used to set multi-layer.
