Solder mask is an essential process in PCB manufacturing. When you see a colored layer on the PCB, that is the solder mask. Solder mask is a negative output, so after the shape of the solder resist layer is mapped onto the board, it exposes the copper instead of applying the solder mask.
There are a total of 9 usual solder masker colors in PCBWay, here is the sample PCBWay ruler:
Meanwhile,the Pink, Grey, Orange and transparent/Clear option are on the "Advanced PCB".
If you are interested in, more information please check our module store.
Paste Mask is also referred to as solder paste. The paste mask is actually a stencil used for surface mount component packaging and corresponds to the pads of the SMD components. It can be directly understood as a stencil made by the paste mask layer. During SMT processing, a steel plate is usually used to punch holes in the corresponding positions of the PCB component pads, and then apply solder paste on the steel plate. When the PCB is placed under the steel plate, the solder paste will flow down and evenly cover each pad with solder. Therefore, the paste mask should not be larger than the actual pad size, and it is best to be smaller than or equal to the actual pad size.
Here are some differences between solder mask and paste mask:
• The openings on solder mask layer have no solder mask ink, but the openings on paste mask layer have paste.
• The solder mask layer is one part on the PCB, but the paste mask layer is not. Paste mask layer is just for the stencil.
• Solder mask is used for applying solder mask ink, but paste mask is used for applying paste.
• Solder mask is used in the PCB manufacturing process, while paste mask is used in PCB assembly phase.
• Solder mask has many available colors, while paste mask is usually gray.
