What role does the solder mask of the PCB circuit board play

Custom PCB assembly circuit board solder mask colors are red, blue, green, white, black and other colors. During the production process, green is commonly used. Many people also call solder mask green oil. Solder mask ink is used before It is in a viscous state. Through printing, pre-bake, alignment, exposure, development, post-curing, etc., all the positions that need to be welded or assembled at the end customer are exposed, without the need for welding or assembly of the substrate , The copper foil position is all covered with solder mask ink. Such a solder mask layer has excellent acid and alkali resistance, solvent resistance, high temperature resistance and other properties.


Solder mask green oil is a liquid photoresist, which is a kind of acrylic oligomer. It is used as a protective layer and is coated on printed circuit board circuits and substrates that do not need to be soldered. Its purpose is to protect the formation for a long time. Line graphics. The main components of liquid optical image welding ink include: epoxy resin and acrylic resin with photographic properties, such as propylene glycol epoxy resin, novolac epoxy resin, medium phenol epoxy resin and ethyl urethane.
What is the function of the solder mask on the PCB board?
(1) Prevent physical disconnection of conductor circuits.
(2) During the welding process, cover the base material between the lines to prevent short circuits between the lines due to bridging.
(3) Cover all the conductive circuits that do not need to be soldered to prevent the copper layer from being oxidized, and solder the parts that only need to be soldered to avoid unnecessary waste of solder