How to improve the stability of alumina polishing slurry?

In recent years, with the development of LED industry and the increasing demand for gem substrates, alumina polishing fluid has a good application prospect in sapphire polishing fluid with its high polishing rate.

However, in the polishing process of alumina polishing fluid has poor dispersion stability, polishing process is easy to appear the phenomenon of agglomeration, polishing surface scratches.Many researchers have studied how to improve the stability of alumina polishing fluid.

Nanometer alumina particles in polar aqueous solution, due to the electrostatic force and other actions of alumina particles agglomerate, prone to flocculation stratification and other phenomena, destroy the dispersion and stability of the polishing fluid. The agglomeration of abrasive particles produces large micelles, which is the main cause of scratches on the substrate surface in chemical-mechanical polishing. The size and distribution of alumina particles, Zeta potential, the type and quality of stabilizer and disdistant added to the polishing liquid have great influence on the stability of the polishing liquid.

The surface modification of nano alumina can improve the particle surface regularity, reduce polishing scratches and pits, and improve the dispersion of alumina abrasive and the stability of polishing fluid.

The common treatment method is to use coupling agent, organic matter, inorganic substance and so on to coat a layer of soft material on the surface of alumina particles with high hardness to reduce polishing scratches and pits and other defects, and then improve the stability and dispersion of alumina polishing fluid, and can effectively improve the abrasion resistance of polishing abrasive.

In addition, the stability of polishing fluid can be improved by changing the Zeta potential of alumina particles.