● What is a solder mask?
● Prevent a solder bridging
When you order PCBs, you can always find solder mask on both sides of PCB as well, which is traditionally green but is now available in many colors. Generally speaking, solder mask is viewed as a coating that protects the circuit from corrosion and electrical shorts. Moreover, it also provides electrical insulation which allows higher voltage traces to be placed nearer to each other.
What is a solder mask?
In PCB design process, the solder mask is always regarded as a layer of the printed circuit board, and is also described as a Gerber file like any other layer, such as the copper and silkscreen layers. Solder mask, also named as solder stop mask or solder resist, is a thin lacquer-like layer of polymer which is usually applied to the PCB traces for protection against environmental conditions, for example, oxidation.
Prevent a solder bridging
More importantly, the solder mask helps keep the solder on the pads, instead of flowing onto traces, planes, or other board space. This contributes to reducing the possibility of solder forming bridges from one element to another. A solder bridge, simply speaking, refers to an undesired electrical connection between two conductors by means of a small blob of solder. But this can be prevented happening with the help of solder masks, by blocking solder bridges from forming between closely spaced solder pads.
Besides, solder masks also play a critical role in a mass production technique of wave soldering, as it enables hand soldering to be much more convenient and efficient.