The circuit board includes many types of working layers, such as signal layer, protection layer, silk screen layer, internal layer, etc., and the roles of each layer are briefly described as follows:
(1) Signal layer: mainly used to place components or wiring. Protel DXP usually contains 30 intermediate layers, namely Mid-Layer 1~Mid-Layer 30, the middle layer is used to arrange signal lines, and the top and bottom layers are used to place components or copper deposits.
(2) Protective layer: It is mainly used to ensure that the places that do not need tin plating on the circuit board are not tinned, to ensure the reliability of the operation of the circuit board. Top Paste and Bottom Paste are the top solder mask and bottom solder mask, respectively, and Top Holder and Bottom Solder are solder paste protection and bottom solder paste protection layer, respectively.
(3) Silk screen printing layer: mainly used to print the serial number, production number, company name and so on of the components on the circuit board.
(4) Inner layer: Mainly used as a signal routing layer, Protel DXP contains a total of 16 internal layers.
(5) Other layers: There are mainly 4 types of layers.
Drill Guide: Mainly used for the location of drilled holes in printed circuit boards.
Keep-Out Layer: Mainly used to draw the electrical borders of the board.
Drill Drawing: This is mainly used to shape the drill hole.
Multi-Layer: Mainly used to set up multi-faceted layers.
