1, TOP LAYER (top wiring layer):
Designed as a top copper foil trace. If it is a single panel, there is no such layer.
2, BOMTTOM LAYER (low-level wiring layer):
Designed for the underlying copper foil traces.
3, TOP / BOTTOM SOLDER (top / bottom solder green layer):
The top layer/bottom layer is provided with solder-resisting green oil to prevent the copper foil from being covered with tin and remain insulated. Solder-resistant solder windows are opened at pads, vias, and non-electrical traces in this layer.
In the design, the pad will open the window by default (OVERRIDE: 0.1016mm), that is, the pad exposes the copper foil, and the outer expansion is 0.1016mm. The tin will be applied during the wave soldering. It is recommended not to make design changes to ensure weldability;
Through-holes are designed to open windows by default (OVERRIDE: 0.1016mm), that is, the vias are exposed to copper foil, with an outer diameter of 0.1016mm, and tin will be applied during wave soldering. If it is designed to prevent tin on vias, and do not expose copper, the PENTING option in the additional properties of the vias, SOLDER MASK, must be checked to close the via opening.
In addition, this layer can also be used for non-electrical wiring alone. If it is on the copper foil trace, it is used to enhance the over-current capability of the trace, plus tin treatment when soldering; if it is on the non-copper foil trace, it is generally designed for marking and special character silk screen printing, which can save production Character silk screen layer.
4. TOP/BOTTOM PASTE (top/bottom solder paste layer):
This layer is generally used for solder paste on SMT components during reflow soldering process. It is not related to the printed board manufacturer’s board. It can be deleted when exporting GERBER. The default can be kept during PCB design.
5, TOP / BOTTOM OVERLAY (top / bottom silk screen layer):
Designed for a variety of silk screen logos, such as component tags, characters, and trademarks.
6, MECHANICAL LAYERS (mechanical layer):
Designed as a PCB mechanical shape, the default LAYER1 is the outline layer. Other LAYER2/3/4 can be used as mechanical dimensioning or special purpose. For example, LAYER2/3/4 can be used when some boards need to make conductive carbon oil, but the use of this layer must be clearly marked on the same layer.
7. KEEPOUT LAYER:
Designed to prohibit the wiring layer, many designers also use the PCB mechanical shape. If there are KEEPOUT and MECHANICAL LAYER1 on the PCB, the overall degree of appearance of these two layers mainly depends on the MECHANICAL LAYER1. It is recommended to use MECHANICAL LAYER1 as the outline when designing. If using KEEPOUT LAYER as the outline, do not use MECHANICAL LAYER1 again to avoid confusion!
8, MIDLAYERS (intermediate signal layer):
Mostly used for multi-layer board, our design is rarely used. It can also be used as a special purpose layer, but the use of this layer must be clearly identified on the same floor.
9. INTERNAL PLANES:
Used for multi-layer board, our design is not used.
10. MULTI LAYER:
Via pad layer.
11. DRILL GUIDE:
The center position coordinate layer of the drill hole and the via hole.
12. DRILL DRAWING:
Drill hole size description layer for pads and vias.