PCB Board Layer Introduction

Toplayer (top) Draw the line is red, is the general double-sided board on the upper layer, single panel can not use this layer.
The Bottomlayer (bottom) line is blue, which is the line above the single panel.
MidLayer1 (middle layer 1) This is the first layer, as if there are 30 layers, the general design staff can not use, you do not have to control him, multi-panel time use. The default is not displayed in 99SE and is not available.
Mechanical Layers (mechanical layer) (purple red) used for labeling size, board instructions, PCB Copy board processing is ignored, that is, the board does not look out, simple point-type annotation meaning.
Top Overlay (upper layer silk screen) (yellow) is the character of the front of the board, corresponding to the Toplayer (top) Single panel on the use of this layer of characters on it, Bottom Overlay (bottom layer) (brown) corresponding to the Bottomlayer (bottom) is the character of the back of the board , two-layer characters are used when double panel.
Keepoutlayer (no wiring layer) (purple-red with the mechanical layer) is simply said to be the frame of the board, the outside.
Multi Layer (Multilayer) (silver) All wiring layers are included, the general single-sided plug-in pad on this layer, the flower line is all the layers are painted.

1.TopLayer (top) top layer routing layer used to draw electrical connections between components.
2.BottomLayer (bottom layer) layer of the underlying wiring, acting on top of the wiring layer.
3.midlayer1 (middle layer 1) is the function of the multilayer board in this layer will also draw electrical cable, but multilayer board cost is higher.
4.Mechanical Layers (mechanical layer) can be used to draw the form of PCB printed circuit board, and the need to dig hole parts, can also be used to do the annotation PCB size, etc., to draw PCB printed circuit board shape, and need to dig holes, pay attention to the PCB shape, knockout parts and PCB annotation size do not use the same mechanical layer , such as the mechanical layer 1 is used to draw the PCB shape and knockout, the mechanical layer 13 for the annotation size, etc., separate after the printed circuit board manufacturers of the technical staff will be based on this layer of things to analyze whether it is necessary to make this layer.
5.Top Overlay (top layer silk screen) (yellow) is the character of the front of the board, corresponding to the Toplayer (top) Single panel on the use of this layer of characters, Bottom Overlay (bottom layer) (brown) corresponding to Bottomlayer (bottom) Is the character of the back of the board, double-panel time to use the above two layers of characters.
6.KeepOutLayer (prohibit wiring layer) role is to draw a prohibited wiring area, if the printed circuit board does not draw a mechanical layer, the printed circuit board manufacturers will use this layer as the PCB profile to deal with. If the keepout layer and the mechanical layer are all the case, the default is the mechanical layer for the PCB shape, but the printed circuit board manufacturers will distinguish themselves, but the case can not be differentiated by default they will be the mechanical layer when the form layer.
7.Multi Layer (Multilayer) (silver) All wiring layers are included, the general single-sided plug-in pad on this layer, the flower line is all the layers are painted.

First, Signal Layers (signal layer)
The Protel98, PROTEL99 provides 16 signal layers: Top (top), Bottom (bottom), and MID1-MID14 (14 intermediate layers).
The signal layer is used to complete the wiring layer of the printed circuit board copper foil traces. In the design of the double-sided board, generally only use top (top) and bottom (bottom) two layers, when the number of printed circuit board layer more than 4 layers, you need to use Mid (intermediate wiring layer).

Second, Internal Planes (internal power/ground plane)
The Protel98, Protel99 provides plane1-plane4 (4 internal power/ground layers). The internal power/ground layer is mainly used for 4 layers of printed circuit board as a special wiring layer for power and grounding, double panel does not need to use.

Three, mechanical Layers (mechanical layer)
The mechanical layer is generally used to draw the border (boundary) of the printed circuit board, usually using only one mechanical layer. There are MECH1-MECH4 (4 mechanical layers).

Iv. Drkll Layers (drilling position layer)
There are 2 layers: "Drill Drawing" and "Drill Guide". Used to draw the borehole aperture and hole positioning.

Five, Solder Mask (solder layer)
There are 2 layers: top (Top level) and bottom (bottom). The solder pads on the solder resist layer are drawn on the printed circuit board and the protective area around the vias.

Six, Paste Mask (solder paste protective layer)
There are 2 layers: top (Top level) and bottom (bottom). Solder paste protective layer is mainly used for surface-mount components of the printed circuit board, the table post components of the installation process required, no table post components do not need to use the layer.

Seven, silkscreen (silk printing layer)
There are 2 layers: top (Top level) and bottom (bottom). Screen printing layer is mainly used for drawing text description and graphical description, such as the outline of components, labels and parameters.

Viii. Miscellaneous (other layers)
has 8 layers: "Keep out (no wiring layer)", "Multi layer (multilayer, all layers of PCB)", "Connect (Connection Layer)" "DRC Error (Error layer)", 2 "Visible Grid (visible grid layer), pad Holes (pad hole layer), and Via Holes (over over bore layer). Some of these layers are used by the system itself, such as the visible grid (visible mesh layer) for the designer to easily locate when drawing. While the keep Put (prohibit wiring layer) is used in automatic wiring, manual wiring does not need to use.
for hand-drawn double-sided printed circuit boards, the most used is the top Layers (top layer copper cabling), Bottom Layers (the underlying copper foil wiring) and top silkscreen (top layer wire primer). Each layer can choose a color of their own habits, the general top layer with red, the bottom with blue, text and symbols with green or white, pad and through the hole with yellow.
Toplayer and Bottomlayer: The top and bottom layers, which are the upper and lower surfaces of the board, usually the signal lines are arranged above, such as a double plate. For multilayer boards, signal layer routing can also be added in the middle.
Mechanical Mechanical Layer: Defines the overall appearance of the PCB board, that is, the overall structure of the PCB board.
Keepoutlayer prohibits wiring layers: Defines the boundary of the copper side of the cloth electrical characteristics. In other words, after the prohibition of the wiring layer is defined, in the subsequent cloth process, the cloth has the electrical characteristics of the line can not exceed the boundaries of the forbidden wiring layer.
Topoverlay Top-level screen printing layer
Bottomoverlay Bottom layer: Defines the screen print characters at the top and bottom, which is the component number and some characters commonly seen on the PCB board.
Toppaste top layer
Bottompaste the underlying pad layer: The copper platinum that we can see outside.
Topsolder Top solder layer
Bottomsolder bottom solder layer: In contrast to the toppaste and bottompaste two layers, it is the layer that covers the green oil.
Drillguide through hole guide layer
drilldrawing hole drilling Layer
Multiplayer multilayer: Refers to all layers of the PCB board.

1.TopLayer component layer, Bottomlayer wiring and plug-in components of the welding layer, Midlayerx middle layer, these layers are used to draw wires or copper cladding (of course, there are toplayer, Bottomlayer SMT patch device pad pads);
2.Top Solder, Bottom Solder, Top Paste, Bottom Paste, these four layers are related to the pad through two or more devices, the general Paste layer of the hole will be smaller than the pad (Paste surface means the solder paste layer, That is, it can be used to make printed solder paste stencil, this layer only need to expose all the need to solder solder pads, and the hole may be smaller than the actual pad; then, to the PCB version of the green Oil (solder mask) bar, this is the solder layer, solder layer to the pad exposed to it, This is what we see in the solder layer only the small circle or small square, generally larger than the pad (solder surface meaning is the solder mask layer, is used to apply the green oil and other solder materials, so as to prevent the solder is not needed to solder, this layer will expose all the solder pads need to weld, And the openings will be larger than the actual pads); These layers are generally yellow (copper) or white (tin);
3.Top Overlay, Bottom Overlay, screen printing layer, PCB surface text or resistor capacitance symbol or device border, etc., generally white;
4.Keepout, draw the border, determine the electrical boundary;
5.Mechanical layer, the real physical boundaries, positioning holes in accordance with the size of the mechanical layer to do, but the PCB factory engineers generally do not understand this. So it is best to send the PCB factory before the keepout layer removed;
6.Multi layer, through each layer, like through hole (to the bottom or top of the vias via also have solder and paste);
7.Drill Guide, drill drawing, drilling layer;

PCB Board Layer Introduction

Toplayer (top) Draw the line is red, is the general double-sided board on the upper layer, single panel can not use this layer. The lines on the
Bottomlayer (bottom) are blue, which is the line above the single panel.
MidLayer1 (middle tier 1) This is the first layer, as if there are 30 layers, the general design staff can not use, you do not have to control him, multi-panel time use. The default is not displayed in 99SE and is not available.
Mechanical Layers (mechanical layer) (purple red) for labeling size, board description, in the PCB processing time is ignored, that is, the board does not look out, simple point-type annotation meaning.
Top Overlay (top layer) (yellow) is the character of the front of the board, corresponding to the Toplayer (top) Single panel on the use of this layer of characters can be,    Bottom Overlay ( Bottom layer) (brown) corresponds to the Bottomlayer (bottom) is the character of the back of the board, double-panel time to use the above two layers of characters.
Keepoutlayer (no wiring layer) (purple-red with the mechanical layer) is simply said to be the frame of the board, the outside.
Multi Layer (multilayer) (silver) All wiring layers are included, the general single-sided plug-in pad on this layer, the flower line is all the layers are painted.

1.TopLayer (top) top layer routing layer used to draw electrical connections between components.
2.BottomLayer (bottom layer) layer of the underlying wiring, acting on top of the wiring layer.
3.midlayer1 (middle layer 1) is the function of the multilayer board in this layer will also draw electrical cable, but multilayer board cost is higher.
4.Mechanical Layers (mechanical layer) can be used to draw the form of PCB printed circuit board, and the need to dig hole parts, can also be used to do the annotation PCB size, etc., to draw PCB printed circuit board shape, and need to dig holes, pay attention to the PCB shape, knockout parts and PCB annotation size do not use the same mechanical layer , such as the mechanical layer 1 is used to draw the PCB shape and knockout, the mechanical layer 13 for the annotation size, etc., separate after the printed circuit board manufacturers of the technical staff will be based on this layer of things to analyze whether it is necessary to make this layer.
5.Top Overlay (top layer silk screen) (yellow) is the character of the front of the board, corresponding to the Toplayer (top) Single panel on the use of this layer of characters, Bottom Overlay (bottom layer) (brown) corresponding to Bottomlayer (bottom) Is the character of the back of the board, double-panel time to use the above two layers of characters.
6.KeepOutLayer (prohibit wiring layer) role is to draw a prohibited wiring area, if the printed circuit board does not draw a mechanical layer, the printed circuit board manufacturers will use this layer as the PCB profile to deal with. If the keepout layer and the mechanical layer are all the case, the default is the mechanical layer for the PCB shape, but the printed circuit board manufacturers will distinguish themselves, but the case can not be differentiated by default they will be the mechanical layer when the form layer.
7.Multi Layer (Multilayer) (silver) All wiring layers are included, the general single-sided plug-in pad on this layer, the flower line is all the layers are painted.

First, Signal Layers (signal layer)
The Protel98, PROTEL99 provides 16 signal layers: Top (top), Bottom (bottom), and MID1-MID14 (14 intermediate layers).
The signal layer is used to complete the wiring layer of the printed circuit board copper foil traces. In the design of the double-sided board, generally only use top (top) and bottom (bottom) two layers, when the number of printed circuit board layer more than 4 layers, you need to use Mid (intermediate wiring layer).

Second, Internal Planes (internal power/ground plane)
The Protel98, Protel99 provides plane1-plane4 (4 internal power/ground layers). The internal power/ground layer is mainly used for 4 layers of printed circuit board as a special wiring layer for power and grounding, double panel does not need to use.

Three, mechanical Layers (mechanical layer)
The mechanical layer is generally used to draw the border (boundary) of the printed circuit board, usually using only one mechanical layer. There are MECH1-MECH4 (4 mechanical layers).

Iv. Drkll Layers (drilling position layer)
There are 2 layers: "Drill Drawing" and "Drill Guide". Used to draw the borehole aperture and hole positioning.

Five, Solder Mask (solder layer)
There are 2 layers: top (Top level) and bottom (bottom). The solder pads on the solder resist layer are drawn on the printed circuit board and the protective area around the vias.

Six, Paste Mask (solder paste protective layer)
There are 2 layers: top (Top level) and bottom (bottom). Solder paste protective layer is mainly used for surface-mount components of the printed circuit board, the table post components of the installation process required, no table post components do not need to use the layer.

Seven, silkscreen (silk printing layer)
There are 2 layers: top (Top level) and bottom (bottom). Screen printing layer is mainly used for drawing text description and graphical description, such as the outline of components, labels and parameters.

Viii. Miscellaneous (other layers)
has 8 layers: "Keep out (no wiring layer)", "Multi layer (multilayer, all layers of PCB)", "Connect (Connection Layer)" "DRC Error (Error layer)", 2 "Visible Grid (visible grid layer), pad Holes (pad hole layer), and Via Holes (over over bore layer). Some of these layers are used by the system itself, such as the visible grid (visible mesh layer) for the designer to easily locate when drawing. While the keep Put (prohibit wiring layer) is used in automatic wiring, manual wiring does not need to use.
for hand-drawn double-sided printed circuit boards, the most used is the top Layers (top layer copper cabling), Bottom Layers (the underlying copper foil wiring) and top silkscreen (top layer wire primer). Each layer can choose a color of their own habits, the general top layer with red, the bottom with blue, text and symbols with green or white, pad and through the hole with yellow.
Toplayer and Bottomlayer: The top and bottom layers, which are the upper and lower surfaces of the board, usually the signal lines are arranged above, such as a double plate. For multilayer boards, signal layer routing can also be added in the middle.
Mechanical Mechanical Layer: Defines the overall appearance of the PCB board, that is, the overall structure of the PCB board.
Keepoutlayer prohibits wiring layers: Defines the boundary of the copper side of the cloth electrical characteristics. In other words, after the prohibition of the wiring layer is defined, in the subsequent cloth process, the cloth has the electrical characteristics of the line can not exceed the boundaries of the forbidden wiring layer.
Topoverlay Top-level screen printing layer
Bottomoverlay Bottom layer: Defines the screen print characters at the top and bottom, which is the component number and some characters commonly seen on the PCB board.
Toppaste top layer
Bottompaste the underlying pad layer: The copper platinum that we can see outside.
Topsolder Top solder layer
Bottomsolder bottom solder layer: In contrast to the toppaste and bottompaste two layers, it is the layer that covers the green oil.
Drillguide through hole guide layer
drilldrawing hole drilling Layer
Multiplayer multilayer: Refers to all layers of the PCB board.

1.TopLayer component layer, Bottomlayer wiring and plug-in components of the welding layer, Midlayerx middle layer, these layers are used to draw wires or copper clad (of course, Toplayer, Bottomlayer SMT SMD device pad pads);
2.Top Solder, Bottom Solder, Top Paste, Bottom Paste, these four layers are related to the penetration of two or more devices pad, the general Paste layer of the hole will be smaller than the pad (Paste surface means the solder paste layer, That is, it can be used to make printed solder paste stencil, this layer only need to expose all the need to solder solder pads, and the hole may be smaller than the actual pad; then, to the PCB version of the green Oil (solder mask) bar, this is the solder layer, solder layer to the pad exposed to it, This is what we see in the solder layer only the small circle or small square, generally larger than the pad (solder surface meaning is the solder mask layer, is used to apply the green oil and other solder materials, so as to prevent the solder is not needed to solder, this layer will expose all the solder pads need to weld, And the openings will be larger than the actual pads); These layers are generally yellow (copper) or white (tin);
3.Top Overlay, Bottom Overlay, silk screen, PCB surface text or resistor capacitance symbol or device border, etc., generally white;
4.Keepout, Draw the border, determine the electrical boundary;
5.Mechanical layer, the real physical boundary, the positioning hole in accordance with the size of the mechanical layer to do, but the PCB factory engineers generally do not understand this. So it is best to send to the PCB factory before the keepout layer is removed;
6.Multi layer, through the layers, like through the hole (to the bottom or the top of the vias via also have solder and paste);
7.Drill Guide, Drill drawing, drilling layer;

Graphic
Layer
Top
Top layer, top layer of copper skin walking line (important)
Internal
The inner layer means that the copper skin traces inside the PCB. The inner layer can not put components, so there is no pad, different from the top and low (important)
Neg Plane
Negative plane (no use in actual engineering)
Pos Plane
Positive plane (no use in actual engineering)
Bottom
Low-rise, top-layer copper-peel route (important)
Border
Border layer, outer frame of PCB
Silk Top
Top-layer screen printing, usually seen by the formation of white oil from this layer (important)
Silk bot
Bottom screen printing, usually seen by the formation of white oil from this layer (important)
Mask Top
The top layer of steel mesh, which is used for SMT steel net file, so SMT components in this layer open hole, plug-in will not open (important)
Mask bot
The bottom steel mesh, which is used for the SMT steel net file, so SMT components in this layer open hole, plug-in will not open hole (important)
Refdes Top
Redefining the top floor this has never been used in actual engineering.
Refdes bot
Redefine low level This has never been used in actual engineering.
Temporary
This is a temporary layer that's never been used in actual engineering.
Insulator
Insulating layer This has never been used in actual engineering.
Paste Top
Top pad, is to expose the copper, non-green oil parts, SMT and plug-in components are required to open the pad (important)
Paste bot
The bottom pad, is to expose the copper, non-green oil parts, SMT and plug-in components are required to open the pad (important)
Nc Primary
No components are installed This is never used in actual engineering.
Nc Secondary
Minor do not install components This has never been used in actual engineering.

According to my many years of PCB experience to answer, it should be easy to understand
PCB design, attention to master my mark (important) on the line, other than books, the actual is not involved in

About the supplement:
Do not know why, you do not have to come out of the drilling layer (drill Drawing), this layer is also very important
There are mainly two points: one is the drilling position, the second is the size of the drill hole

PCB generally have two pad layer (the top floor, the inner layer is no pad, because there is no way to install components), a drilling layer. The solder pads and drilling layers are completely different concepts, the solder tray layer points out the need to install components of the pad shape position, the drilling layer is to locate and define the location of the hole.
PCB software, you can use powerPCB2005, than Protel99 to be flexible, can meet the requirements you say

Explain, like drilling layer, screen printing layer, and so on, when you draw the PCB, you do not need to pay special attention to them, they will generate their own PCB Gerber files.
For example, the route needs to go from the top floor to the top layer, only need to hit a hole on the line, do not need to deliberately pay attention to the hole is not placed in the drilling layer, it itself is there

Graphic Layers
Top floor
Internal inner Layer
Neg Plane Negative
Pos Plane Front
Bottom Low Floor
Border Border Layer
Silk top layer Screen printing
Silk bot Bottom Screen printing
Mask top top Layer Steel mesh
Mask bot Bottom Steel mesh
Refdes Top Redefine Tops
Refdes bot redefine low level
Temporary temporary layer
Insulator Insulating Layer
Paste Top Solder Pads
Paste Bot Bottom Pad
Nc Primary Main air-skipping element
Nc Secondary secondary space-skipping element

PCB Board Layer Introduction