Solder Mask和Paste Mask
In the PCB design, the pad file needs to be drawn. For the two layers of Solder Mask Layers and Paste Mask layers,many people don't understand much. The following is a brief description.
Solder mask: Solder mask, also known as green oil layer, generally set slightly larger than the pad by 0.102mm.
Paste mask: The soldering layer, also called the steel mesh layer, needs to be set for the surface mount component, generally the same as the pad size;
If a trace is required, the copper or pad window does not cover the green oil and is sprayed with tin or immersion gold.
In the solder layer corresponding to the circuit layer that needs to leak copper, the paste is only the steel mesh layer (the PCB backplane factory does not process this layer),Use to make steel mesh, it has nothing to do with the production of the board.