In the process of PCB production, ink is indispensable. Ink can be divided into three types. Do you know which three types are?
1. Circuit Ink
The substrate of the PCB board is a copper clad laminate. There is a layer of copper foil on it, and the circuit ink needs to be exposed, developed and cured by silkscreen printing. After the circuit is etched, the ink will be removed with an aqueous sodium hydroxide solution. In addition, the circuit ink will protect the circuit during etching.
2. Solder Mask Ink
There is a layer of green paint on the common PCB, which is actually solder mask ink. According to the curing method, solder mask inks include photosensitive and developing inks, heat-cured thermosetting inks and UV light-cured UV inks. According to the base material classification, there are rigid PCB solder mask ink, FPC solder mask ink, and aluminum PCB solder mask ink. Aluminum PCB ink can also be used on ceramic boards. The main function of this solder mask ink is to insulate and prevent oxidation.
3. Silkscreen Ink
Common silkscreen inks are white and black. White is more used than black. Except for PCB with white solder mask, PCB with other colors basically use white silkscreen ink.
Most of the PCB, such as aluminum PCB, light strip board, and backlight, use white solder mask ink, so the characters on them are generally printed with black silkscreens. Some also use yellow or other color silkscreen inks because of customer demand. The main function of this type of silkscreen ink is to print silkscreen and mark component symbols.