Soldermask:Solder resist layer, where it is used to coat the green oil solder resist material to prevent solder contamination without welding, this layer will be exposed to all the pads to be soldered, and the aperture ratio will actually land larger. When painted green oil, to see something ( pads ) where oil can not be painted green, and because of its larger opening than the actual pads, ensure green oil is not applied to the pad , this layer information We need to provide PCB plant.soldermask and understanding pastemask
Pastemask: Paste layer, that is to say it can be used to produce solder paste stencil printing, this layer is exposed only patch welding all required pads, and the openings may be smaller than the actual pads. The thus-obtained steel hollow place is smaller than the actual pads, to ensure that when the brush solder paste will not paste to brush up green oil , this layer information to be provided to SMT factory
Differences between solder mask and paste mask:
1. The openings on solder mask layer have no solder mask ink, but the openings on paste mask layer have paste.
2. The solder mask layer is one part on the circuit board, but paste mask layer is just for the stencil.Solder mask is applied when making PCB board while paste mask is used when assembling.
3. Solder mask is used for applying solder mask ink, but paste mask is used for applying paste.
4. Solder mask available many colors, but paste mask is usually gray.