PCB Inks-Circuit Ink, Solder Mask Ink, Marking Ink

PCB inks are generally divided into three types: circuit inks, solder mask inks, and marking inks.

Circuit ink is used as the barrier layer of the anti-corrosion line to protect the line during etching. Generally, it is a liquid photosensitive type. There are two types of acid corrosion resistance and alkaline corrosion resistance. This layer of ink needs to be dissolved with alkali after corroding the circuit.

Solder mask ink is applied to the circuit after the circuit is completed to protect the circuit. There are liquid photosensitive, thermal curing, and ultraviolet curing type. The pads are reserved on the board to facilitate soldering of components and play the role of insulation and oxidation resistance.

Marking ink is used to mark the board surface, such as marking component symbols, etc., generally white color.

In fact, there are other inks, such as peelable inks, which can protect the parts that do not need to be treated when doing copper plating or surface treatment, and then tear them off; there are also silver paste inks, etc.

The commonly used ink colors are white, green, black, blue, red, yellow.

In addition, what should be paid attention to when using PCB ink? According to the actual experience of most manufacturers using ink, the following regulations must be referred to when using ink:

1. In any case, the temperature of the ink must be kept below 20-25°C, and the temperature should not change too much, otherwise it will affect the viscosity of the ink, the quality of screen printing, and the effect of use. Especially when the ink is stored outdoors or at different temperatures, it must be placed at ambient temperature for several days or the ink tank must reach an appropriate operating temperature before use. Because the use of cold ink will cause screen printing failure. Therefore, in order to maintain the quality of the ink, it is best to store it at room temperature.

2. Before use, the ink must be fully and finely mixed manually or mechanically. If air enters into the ink, it should be allowed to stand for a while when using it. If you need to dilute, you should mix well first, and then check its viscosity. You need to seal the ink tank immediately after use. At the same time, do not put the ink on the screen back into the ink tank and mix it with unused ink.

3. It is best to clean the network with mutually compatible cleaning agents to achieve a thorough clean. When cleaning again, you need to use a clean solvent.

4. When the ink is dried, it must be done in a device with a good exhaust system.

5. Keep the screen printing operation in an environment where the operating conditions meet the technological requirements of the process.