5.2.1. Paired layers
The Adhesives layers (Copper and Component):
These are used in the application of adhesive to stick SMD components to the circuit board, generally before wave soldering.
红胶层？
待末确认。
The Solder Paste layers paste SMD (Copper and Component):
Used to produce a masks to allow solder paste to be placed on the pads of surface mount components, generally before reflow soldering. In theory only surface mount pads occupy these layers.
锡膏层
用于制作钢网
The Silk Screen layers (Copper and Component):
They are the layers where the drawings of the components appear.
丝印层
一般用于印制元件编号和参数，及其它文字和LOGO。
The Solder Mask layers (Copper and Component):
These define the solder masks. Normally all the pads appear on one or the other of these layers (or both for through pads) to prevent the varnish covering the pads.
阻焊层
一般也叫绿油层
5.2.2. Layers for general use
Comments
E.C.O. 1
E.C.O. 2
Drawings
These layers are for any use. They can be used for text such as instructions for assembly or wiring, or construction drawings, to be used to create a file for assembly or machining.
5.2.3. Special layer
Edge Cuts layer:
this layer is reserved for the drawing of circuit board outline. Any element (graphic, texts…) placed on this layer appears on all the other layers. Use this layer only to draw board outlines.
切割层 用于绘制板框