PCB News - The role and introduction of each layer when making a PCB board

TOP LAYER (top wiring layer):
Designed as the top copper foil trace. If it is a single-sided board, there is no such layer.
2. BOMTTOM LAYER (bottom wiring layer):
Designed as the bottom copper foil trace.
3. TOP/BOTTOM SOLDER (top/bottom solder mask green oil layer):
Put solder mask green oil on the top/bottom layer to prevent tin on the copper foil and maintain insulation. Open the window with solder mask at the pads, vias and non-electrical traces on this layer.
In the design, the soldering pad will open a window by default (OVERRIDE: 0.1016mm), that is, the soldering pad exposes the copper foil and expands by 0.1016mm, and it will be tinned during wave soldering. It is recommended not to make design changes to ensure solderability;
In the design of the via hole, the window will be opened by default (OVERRIDE: 0.1016mm), that is, the via hole exposes the copper foil and expands by 0.1016mm, and it will be tinned during wave soldering. If the design is to prevent tin on the vias and not expose the copper, you must check the PENTING option in the additional properties of the vias SOLDER MASK (solder mask opening) to close the via opening.
In addition, this layer can also be used for non-electrical wiring separately, and the solder mask green oil will open the window accordingly. If it is on a copper foil trace, it is used to enhance the overcurrent capability of the trace, and tin is added during soldering; if it is on a non-copper foil trace, it is generally designed for logo and special character silk screen printing, which can be omitted. Character silk screen layer.
4. TOP/BOTTOM PASTE (top/bottom solder paste layer):
This layer is generally used to apply solder paste during the SMT reflow soldering process of SMT components, and has nothing to do with the printed board manufacturer's board. It can be deleted when exporting the GERBER, and the PCB board design can keep the default.
5. TOP/BOTTOM OVERLAY (top/bottom screen printing layer):
Designed as a variety of silk screen logos, such as component number, characters, trademarks, etc.
6. MECHANICAL LAYERS (mechanical layer):
Designed as the mechanical shape of the PCB board, the default LAYER1 is the shape layer. Other LAYER2/3/4, etc. can be used for mechanical size marking or special purposes. For example, when certain boards need to be made of conductive carbon oil, LAYER2/3/4, etc. can be used, but the purpose of the layer must be clearly marked on the same layer.
7. KEEPOUT LAYER (prohibited wiring layer):
The design is to prohibit the wiring layer. Many designers also use the mechanical shape of the PCB board. When making the PCB board, there are both KEEPOUT and MECHANICAL LAYER1. The main consideration is the integrity of the two layers. Generally, MECHANICAL LAYER1 shall prevail. It is recommended to use MECHANICAL LAYER1 as the shape layer when designing. If you use KEEPOUT LAYER as the shape, do not use MECHANICAL LAYER1 to avoid confusion!
8. MIDLAYERS (middle signal layer):
It is mostly used for multi-layer boards, but our design is rarely used. It can also be used as a special-purpose layer, but the purpose of the layer must be clearly marked on the same layer.
9. INTERNAL PLANES:
It is used for multi-layer boards, which is not used in our company's design.
10. MULTI LAYER (via layer):
Via-hole pad layer.
11. DRILL GUIDE (drilling positioning layer):
Position the coordinate layer at the center of the pad and the hole of the via hole.
12. DRILL DRAWING (drilling description layer):
The description layer of the hole diameter size of the pad and the via hole.

The above is the role and introduction of each layer when making PCB boards. ipcb company also provides PCB manufacturers, circuit board design technology, etc.