PCB ink refers to the ink used in Printed Circuit boards. 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 be of excellent quality. PCB ink quality depends on whether the formula is scientific, advanced and environmentally friendly. It is embodied in:

Viscosity is short for dynamicviscosity. The viscosity is typically expressed as the shear stress of the fluid flow divided by the velocity gradient in the direction of the flow layer, in Si pas/SEC (Pa). S) or millipas/second (mPa). S). In PCB production refers to the fluidity of ink driven by external forces.

Conversion relation of viscosity unit:

1. Of pa. S = 10 p = 1000 mpa. S=1000CP=10dpa.s

2. Plasticity refers to ink deformation by external force, still maintain its deformation before the nature. The plasticity of ink is conducive to improving printing accuracy;

3. Thixotropic (thixotropic) ink in the static gelatinous, and when touched by a change in viscosity of a property, also known as shaking, flow resistance;

Analysis of the technical performance of PCB ink process

4. Liquidity (leveling) ink under the action of external forces, to the extent of the spread around. Fluidity is the reciprocal of viscosity, fluidity and ink plasticity and thixotropy. Large plasticity and thixotropy, large fluidity; The imprinting is easy to expand with high fluidity. Small fluidity, easy to appear net, ink phenomenon, also known as reticulation;

5. Viscoelasticity refers to the ink in the scraper after scraping, the ink is cut and broken quickly rebound performance. Printing ink deformation speed, ink rebound quickly to facilitate printing;

6. Drying requirements of ink on the screen drying the slower the better, and hope to transfer ink to substrate, the faster the better;

7. Fineness pigment and solid particle size, PCB ink is generally less than 10μm, fineness should be less than one third of the mesh opening;

8. Drawing ink spatula to pick up ink, filamentous ink stretching is not broken degree known as drawing. Long ink, ink surface and printing surface appear a lot of filaments, so that the substrate and plate dirty, even can not print;

9. Ink transparency and hiding power

For PCB ink, according to the use and requirements of different ink transparency and hiding power also put forward various requirements. In general, line ink, conductive ink and character ink, are required to have a high hiding power. And flux resistance is more flexible.

10. Chemical resistance of ink

PCB ink according to the use of different purposes, the corresponding requirements of acid, alkali, salt and solvent requirements have strict standards;

11. Physical characteristics of ink resistance

PCB ink must be resistant to external scratches, heat shock, mechanical peeling, and meet various stringent electrical performance requirements;

12. The use of ink safety and environmental protection

PCB ink requires low toxicity, odorless, safety and environmental protection.