The meaning of each layer of PCB (solder paste difference)

Definition of PCB layer:

Solder Mask: Solder masks, refers to the board on the green oil on the part, because it is negative output, so actually there is solder mask part of the actual effect is not on the green oil, but tin plating, silver.

Help solder layer: Paste mask, is the machine to use the patch, is corresponding to all SMD components of the pad, the size and Toplayer/bottomlayer layer, is used to open the steel network leakage tin.

Key points: Two layers are used for soldering, not refers to a tin, a green oil; Then there is no layer refers to the layer of green oil, as long as a certain area of the layer, it means that the area is insulated green oil. For the time being I have not met such a layer. We draw the PCB board, the top of the pad by default, there are solder layer, so made of PCB board part is on the silver-white solder, not on the green oil this is not strange; but we draw the PCB board on the line part, only the toplayer or Bottomlayer layer, There is no solder layer, but the PCB board is made of traces on the part of a layer of green oil.

That can be understood as follows: 1, solder resistance layer means that the whole piece of green Oil resistance welding window, the purpose is to allow welding. 2, by default, no solder layer of the area to be on the green oil. 3, Paste mask layer for SMD package. SMT package used: Toplayer layer, Topsolder layer, toppaste layer, and Toplayer and toppaste the same size, topsolder than their large circle. Dip package only used: Topsolder and Multilayer layer (after some decomposition, I found that the multilayer layer is actually toplayer,bottomlayer,topsolder,bottomsolder layer size overlap), and topsolder/bottomlayer than Toplayer/bottomlayer big circle.

Question: "The copper cortex corresponding to the solder layer is tinned or gilded with copper" is the correct sentence. This sentence is a work in the production of the PCB factory people said, he means: to make the painting in the solder layer produced by the effect is tin-plated, Then the corresponding solder layer should have a copper skin (i.e., the area corresponding to the solder layer to have the Toplayer or bottomlayer layer of the part). Now: I come to the conclusion that: "The copper cortex of the solder layer corresponds to copper plating tin or gold plating" is the correct sentence. The solder layer represents an area that does not cover the green oil.

Mechanical, mechanical layer
Keepout layer prohibit cabling layers
Top Overlay top layer screen bottom overlay bottom screen layer
Top paste, top layer
Bottom Paste Bottom pad layer
Top solder layer Solder overlay
Bottom solder bottom solder layer
Drill guide, through hole guidance layer
Drill drawing through hole drilling layer
Multilayer Multilayer br> mechanical layer is the definition of the entire PCB board appearance, in fact, we say that the mechanical layer is the entire PCB board shape structure. The prohibition of wiring layers is the boundary that defines our copper at the electrical characteristics of the cloth, that is, after we define the forbidden wiring layer, we in the subsequent cloth process, It is impossible to exceed the boundary of the forbidden wiring layer by the cloth with the electrical characteristic. Topoverlay and Bottomoverlay are the print characters that define the top and bottom, which is the component number and some characters that we see on the PCB board. Toppaste and Bottompaste is the top layer of the bottom layer, it means we can see the outside of the copper platinum, (for example, we draw a wire in the top layer of wiring, this wire we see on the PCB is just a line, it is covered by the whole green oil, But we draw a square on the toppaste layer in the position of this line, or a point, and the square on the plate and this point will not have green oil, but copper platinum. Top solder and Bottomsolder these two layers just opposite the front two layers, it can be said that the two layers is to cover the layer of green oil, multilayer this layer is actually similar to the mechanical layer, GU apprentice, this layer refers to all the layers of the PCB board. The two layers of the
top solder and Bottomsolder are just the opposite of the previous two layers, so to speak, these two layers are the layers to cover the green oil;
because it is a negative output, the actual effect of the solder mask is actually not green oil, but tin plated, Silvery White. The
1 Signal layer (signal layer)
signal layer is primarily used to lay out the conductors on the board. Protel. SE provides 32 signal layers, including top layer, Bottom layer (bottom), and 30 midlayer (middle layer).

2 Internal plane Layer (internal power/ground plane)
Protel. SE provides 16 internal power layer/ground plane. This type of layer is used only for multilayer boards and is mainly used to lay out power and grounding wires. We call the double-decker, four-ply, six-ply, generally referred to as the number of signal layers and internal power/ground layers.

3 mechanical layer (mechanical)
Protel SE offers 16 mechanical layers, which are generally used to set the board's form factor, data markers, alignment marks, assembly instructions, and other mechanical information. This information varies according to the requirements of the design company or PCB manufacturer. Execute menu Command design| The Mechanicallayer can set more mechanical layers for the circuit board. In addition, the mechanical layer can be attached to other layers together to output the display.

4 Solder Mask layer (solder barrier)
Apply a layer of paint, such as solder paint, to each part of the pad to prevent tin on these parts. The solder resist layer is used to match the pads during the design process and is automatically generated. Protel SE offers two solder-resistant layers for top Solder (top) and bottom Solder (bottom layer).

5 Paste Mask Layer (solder paste protective layer, SMD SMT layer)
It is similar to the solder resist layer, and differs from the solder pads of the surface-mounted components that correspond to the welding of the machine. Protel99 SE provides two solder paste protection layers for top Paste (top) and bottom Paste (bottom layer).
Mainly for SMD components on the PCB board. If the plates are all placed in dip (through hole) elements, this layer does not have to output the Gerber file. SMD components on the PCB board before, must be on each SMD pad first coated with solder paste, in the tin coated with the steel mesh must need this paste mask file, the film can be processed.
Paste Mask Layer Gerber Output The most important point to be clear, that is, this layer is mainly for SMD components, at the same time the layer with the above-described solder mask to make a comparison, to understand the difference between the two, because the film in the film to see the picture is very similar.
6 Keep out layer (no wiring layers)
Used to define areas where components and cabling can be effectively placed on the board. In this layer, a closed area is drawn as the routing active area, which cannot be automatically laid out and routed outside the area.

7 silkscreen layer (silk screen)
Screen printing layer is mainly used for placing printed information, such as the outline of components and annotations, various comment characters. Protel-SE offers the top overlay and bottom overlay two silk print layers. In general, a variety of label characters are in the top layer of screen printing layer, the bottom layer of the screen can be closed.
8 Multi Layer (multilayer)
The circuit board and the penetration through the hole to penetrate the entire circuit board, and different conductive graphics layer to establish an electrical connection, so the system is specifically set up an abstract layer-multilayer. Generally, pads and vias should be set on multiple layers, if the layer is closed, the pads and vias can not be displayed.

9 Drill Layer (bore)
The drilling layer provides drilling information in the manufacturing process of the circuit board (e.g. pads, holes need to be drilled). Protel. SE provides a drillgride (borehole indicator) and drill drawing (drilling diagram) two drilling layers.

To distinguish between solder mask and solder bonding layer
: Solder masks, refers to the board on the green oil on the part, because it is a negative output, so actually there is solder mask part of the actual effect is not green oil, but tin plating, silver.
Solder layer: Paste mask, is the machine to use the patch, is corresponding to all SMD components of the pad, the size and Toplayer/bottomlayer layer, is used to open the steel network leakage tin.
Important: Two layers are used for soldering, not refers to a tin, a green oil; Then there is no layer of green oil, as long as there is a certain area of the layer, it means that the area is insulated green oil. For the time being I have not met such a layer. We draw the PCB board, the top of the pad by default, there are solder layer, so made of PCB board part is on the silver-white solder, not on the green oil this is not strange; but we draw the PCB board on the line part, only the toplayer or Bottomlayer layer, There is no solder layer, but the PCB board is made of traces on the part of a layer of green oil.
that can be understood as follows: 1, solder resistance layer means that the whole piece of green Oil resistance welding window, the purpose is to allow welding. 2, by default, no solder layer of the area to be on the green oil. 3, Paste mask layer for SMD package. SMT packaging used: top layer, top solder layer, top paste layer, and top layer and top paste the same size, topsolder than their large circle. Dip package only used: Topsolder and Multilayer layer (after some decomposition, I found that the multilayer layer is actually toplayer,bottomlayer,topsolder,bottomsolder layer size overlap), and topsolder/bottomsolder than Toplayer/bottomlayer big circle.