12 important PCB ink technical performance indicators

The quality of PCB ink has an important impact on the quality of printed circuit boards. This article will discuss the quality of PCB ink in depth, including its key performance indicators and its comprehensive impact on PCB manufacturing.

Understand the key performance indicators of PCB inks

1. viscosity

Viscosity is one of the key properties of PCB inks. It refers to the fluidity of the ink that is driven by an external force. The level of viscosity is directly related to the smoothness of printing. In PCB production, viscosity is usually expressed in pascals per second (Pa·s) or millipascals per second (MPa·s). Moderate viscosity is conducive to the accuracy of printing.

2. Plasticity

The plasticity of PCB ink refers to its ability to maintain its pre-deformation properties after being subjected to external forces. Good plasticity helps to improve the printing accuracy and ensure that no deformation or distortion occurs during the printing process.

3. Thixotropic

Thixotropic refers to the property that the ink is gelatinous when standing, but its viscosity changes when touched. This property makes the ink easier to control when printing and helps prevent excessive or premature flow.

4. liquidity

Fluidity refers to the degree to which the ink expands around under the action of external forces. It is closely related to viscosity, plasticity and thixotropic properties. Inks with large fluidity are easy to diffuse, while inks with small fluidity are prone to netting and ink formation.

5. Viscoelasticity

Viscoelasticity refers to the performance of the ink that is cut and broken after it is scraped by the scraper and can quickly rebound. This contributes to the speed and quality of printing.

6. dryness

The dryness of the ink requires a moderate drying speed on the screen, but once transferred to the substrate, a faster drying speed is required to ensure the printing quality.

7. Fineness

Fineness refers to the size of the pigment and solid material particles. PCB inks usually require a particle size of less than 10μm to ensure the fineness of printing.

8. Brushed

The drawing properties indicate whether the ink is easy to break into filamentous shape when it is stirred up. Longer ink filaments may lead to poor printing, so it is necessary to control the drawing properties.

9. Transparency and hiding power

Transparency and hiding power vary according to different uses and requirements. Circuit inks, conductive inks, and character inks usually require higher hiding power, while flux inhibitors require more flexibility.

10. Chemical resistance

PCB inks must be able to withstand the effects of chemicals such as acids, alkalis, salts, and solvents, and corresponding standards must be formulated according to different uses.

11. Physical resistance

PCB inks must also meet a series of physical characteristic requirements, including resistance to external scratches, heat-resistant impact, and mechanical peeling.

12. Safe to use and environmentally friendly

Finally, PCB inks also need to have low toxicity, odorless, safe and environmentally friendly characteristics to ensure operator safety and environmental friendliness.

Viscosity and thixotropic: key factors affecting printing accuracy

In PCB inks, viscosity and thixotropic properties are two key factors affecting printing accuracy. The level of viscosity directly affects the smoothness of printing, while the thixotropic properties affect the control of the ink in the printing process. The two need to be balanced to achieve the desired printing effect.

However, experience has shown that even if the viscosity control is mastered, sometimes the ideal resolution cannot be achieved. Thixotropic is another important factor, which plays a key role in printing accuracy. Therefore, in the preparation and use of PCB ink, these two factors need to be considered comprehensively to ensure the stability of the printing process and the printing quality.

The quality of PCB ink is a comprehensive manifestation of science, advanced and environmental protection. It involves a number of performance indicators, including viscosity, plasticity, thixotropic properties, fluidity, viscoelasticity, dryness, fineness, drawing, transparency, hiding power, chemical resistance, physical resistance, safety of use and environmental protection.

These performance indicators need to be adjusted according to the specific requirements of PCB manufacturing to achieve printing accuracy and reliability.

In the PCB manufacturing process, the operator needs to pay close attention to the two key factors of viscosity and thixotropic to ensure that the printing accuracy reaches the best level. At the same time, in order to detect problems in advance and avoid losses, strain tests should be carried out to determine whether the stress of the PCB board is within the allowable range.

Through scientific management and meticulous operation, the quality of PCB ink can be ensured, thereby improving the quality and reliability of the circuit board.

Frequently asked questions

1. How to measure the viscosity of PCB ink?

The viscosity of PCB ink is usually measured using a viscosity tester. When testing, you need to specify the test conditions to ensure the accuracy of the results.

2. Why is thixotropic important to printing accuracy?

Thixotropic properties affect the fluidity and control of the ink in the printing process, which is essential for printing accuracy.

3. How to ensure the environmental protection of PCB ink?

The environmental protection of PCB inks can be ensured by choosing environmentally friendly materials and following relevant environmental standards.

4. Why should strain testing be carried out in PCB manufacturing?

Strain testing can help determine the stress level of the PCB board to prevent possible damage and quality problems.

5. How to improve the resolution of PCB printing?

In addition to controlling viscosity and thixotropic properties, the resolution of PCB printing can also be improved by optimizing printing equipment and processes.