1. Drilling layer: The drilling layer provides drilling information in the circuit board manufacturing process (such as pads, vias need to be drilled).
2. Signal layer: The signal layer is mainly used to arrange the wires on the circuit board.
3. Solder resist layer: Apply a layer of paint, such as solder resist paint, on all parts other than the pad to prevent tin from appearing on these parts. Soldermask is used to match pads during the design process and is automatically generated.
4. Tin protective layer, s-md patch layer: Its function is similar to that of the solder mask layer, except that it is the pad corresponding to the surface bonding parts during machine welding.
5. Forbidden wiring layer: used to define the area where components and wiring can be effectively placed on the circuit board. Draw a closed area on this layer as an effective area for routing. Normally, it is impossible to automatically place and route outside this area.
6. Silk screen layer: The silk screen layer is mainly used to place printing information, such as outlines and marks of components, various annotation characters, etc. Usually, various marking characters are placed on top of the silkscreen layer, and the bottom silkscreen layer can be turned off.
7. Internal power/ground layer: This layer is only used for multi-layer boards, and is mainly used to arrange power lines and ground lines. We call them two-layer boards, four-layer boards, and six-layer boards, which usually refer to the number of signal layers and internal power/ground layers.
8. Mechanical layer: It is generally used to set the mechanical information such as the external dimensions, data marks, alignment marks, and assembly instructions of the circuit board. This information changes according to the requirements of the design company or PCB manufacturer.
The above is about the meaning and function of each layer of PCB! Hope it can help you!
