● Solder Flow
● Solder Mask
We’ll know that copper layer plays an important part in PCB, as it’s used for electric conduction.As a metal, copper can easily react with oxygen and influence its electrical conductivity. Hence,the solder mask is fairly essential during the PCB manufacture process.
Solder Flow is a process that solder is applied to the external surfaces of the board on exposed copper areas. Indeed, it’s considered as the preparation for board soldering which protects the copper from oxidation. The copper areas of the board may be solder flowed, or a process called SMOBC(Solder Mask Over Bare Cropper) will be used. In SMOBC process, only the exposed area (usually pads or areas that are to be soldered) will be coated with solder flow.
Solder mask is a material that is used to coat the board for protecting copper, so it has other names like solder stop mask or solder resist. As for color, solder mask is traditionally green but is now available in many colors including red, black, etc. It is a thin lacquer-like layer of polymer that is usually applied to the copper traces of a PCB, which is used for the following functions:
* Protect from surrounding environment.
* Insulate the board electrically
* Protect against solder bridges
* Protect components mounted to the board.
* Protect the board from heat generated from components mounted to the board.