Significance of layers in PCB cabling

Top-level wiring layer of toplayer-signal Layer

Bottom underlying wiring layer-signal Layer

The connections of each pad are on the signal layer, that is, the connections of each component pin on the circuit board.

Mechanical Layer

-- Define the appearance of the entire PCB. In fact, when we say that the mechanical layer refers to the shape structure of the entire PCB Board.

Keepoutlayer disallow the wiring Layer

-- Disallow a wiring layer is defined at the boundary of electrical properties. That is to say, after a wiring layer is defined, in the future wiring process, the wiring with electrical properties cannot exceed the boundary of keepoutlayer.

Top-Layer Screen Printing layer of topoverlay

Bottomoverlay underlying Screen Printing Layer

-- The top-layer and bottom-layer silk screen characters are the component numbers and some characters we usually see on the PCB.

Toppaste top Pad Layer

Bottompaste bottom Pad Layer

-- We can see copper and platinum exposed outside. For example, we drew a wire in toplayer. What we see on the PCB is only a wire. By default, it is covered by the entire Green Oil, however, we draw a square or a dot on the toppaset layer at the position of the wire. The square on the plate made out has no green oil, but copper and platinum.

Because the PCB is green by default, a "Skylight" will be opened in the place where the two layers are laid, rather than green. It can be used in some places where large current flow is needed to facilitate addition of Solder

Topsolder top-layer Solder Mask

Bottomsolder underlying Solder Mask

-- The full name of the solder layer in Protel 99se is the top Solder Mask, which means the solder mask. To understand it literally, it is to provide an online green layer for the PCB to achieve the purpose of Solder Mask, otherwise, if the solder layer is not added after the cabling, the green oil will be added by default when it is created by the PCB manufacturer. If the solder layer is added, after the PCB is made, the exposed copper foil is displayed here. It can be understood as the mirror phase.

Drillguide through-hole guide Layer

Drilldrawing over-hole drilling Layer

1. drillguide is used for guidance drilling and is mainly used for manual drilling to locate. 2. drilldrawing is used to view the drilling hole diameter. When manual drilling is performed, these two files should be used together. However, most of them are numerical control drilling, so these two layers are not very useful. When placing positioning holes, you don't need to place content on these two layers. You just need to put the hole through the pad on the michanical, toplayer, or bottomlayer, but you only need to place the disc diameter smaller.

Multilayer

-- Generally, the overpasses are placed in multiple layers.