PCB ink refers to the printing board (printed circuit board, referred to as PCB) of the ink, the important physical characteristics of the ink are viscosity, thixotropy, and fineness. These physical properties need to be known to improve the ability to use ink.

What kinds of PCB ink _PCB ink function introduction

PCB ink characteristics

1. Viscosity and thixotropy

In the printed circuit board manufacturing process, screen printing is one of the indispensable important processes. In order to obtain the fidelity of image reproduction, the ink must have good viscosity and suitable thixotropy. The so-called viscosity is the internal friction of liquid, which means that under the action of external force, one layer of liquid slides on another layer of liquid, and the friction force exerted by the inner layer of liquid. Thick liquid inner layer sliding encountered greater mechanical resistance, thinner liquid resistance is less. Viscosity is measured in pools. In particular, it should be noted that temperature has a marked effect on viscosity.

Thixotropy is a physical property of a liquid, that is, the viscosity of the liquid decreases under agitation, and soon restores to its original viscosity after standing. By stirring, the thixotropic action lasts long enough to reconstitute its internal structure. To achieve a high-quality screen printing effect, ink thixotropy is very important. Especially in the scraper process, the ink is stirred and then make its liquid. This role speeds up the ink through the mesh speed, promotes the original line separate ink evenly connected into one. Once the scraper stops moving, the ink returns to a static state, and its viscosity quickly returns to the original required data.

2. Fineness

Pigments and mineral fillers are generally solid, finely ground to particle sizes of no more than 4/5 micron, and form a homogeneous flow state in a solid form. Therefore, it is very important to require fine ink.

What kinds of PCB ink _PCB ink function introduction

Type of PCB ink

PCB ink is mainly divided into three lines, blocking welding, character ink three types.

Line ink is used as a barrier layer to prevent corrosion of the line when etching to protect the line, generally liquid sensitive type. There are two kinds of acid corrosion resistance and alkaline corrosion resistance, alkali resistance is more expensive, this layer of ink in the corrosion of the line uses alkali to dissolve it.

Solder ink is painted on the line as a protection line after the line. There are liquid photosensitive and heat curing, and ultraviolet hardening types, keep the pad on the board, convenient welding components, insulation, and oxidation resistance.

Character ink is used to do board surface marking, such as marking components symbols, generally white.

In fact, there are other inks, such as peeling ink, is to do copper plating or surface treatment do not need to deal with part of the protection, and then can be torn off; Silver ink and so on.

What kinds of PCB ink _PCB ink function introduction

PCB ink use matters needing attention

According to the actual experience of the use of ink by most manufacturers, the use of ink must be carried out in accordance with the following provisions:

1. In any case, the temperature of the ink must be kept below 20-25℃, temperature change can not be too large, otherwise, it will affect the viscosity of the ink and screen printing quality and effect.

Especially when the ink is stored outdoors or stored at different temperatures, it must be placed in the ambient temperature to adapt to a few days or make the ink barrel to achieve the appropriate temperature. This is because the use of cold ink will cause screen printing failure, causing unnecessary trouble. Therefore, to maintain the quality of ink, it is best to store or store in normal temperature process conditions.

2. Before use, the ink must be fully and carefully manually or mechanically stirred evenly. If the ink into the air, use to stand for a period of time. If dilution is required, mix thoroughly first and then test the viscosity. The ink barrel must be sealed immediately after use. At the same time, never put the screen ink back into the ink barrel and unused ink mixed together.

3. The cleaning agent that had better use mutual adaptation undertakes clear net, and want very thoroughly clean. When cleaning again, it is best to use a clean solvent.

4. Ink drying, must have a good exhaust system in the device.

5. To maintain operating conditions should meet the technical requirements of the operation site for screen printing operations.

What kinds of PCB ink _PCB ink function introduction

What is the role of PCB ink in the PCB manufacturing process

Ink plays a role in the production of copper foil protection so that the copper skin is not exposed, will affect the following process, sensitive ink, carbon oil, silver oil, and carbon oil and silver oil have conductivity to do, usually used ink color, white oil, green oil, black oil, blue oil, red oil, butter.