A kind of oil-in-oil acidic ionic liquid polishing fluid for kdp crystal

Abstract

The invention provides oil-package acidic-ionic-liquid (AIL) polishing liquid for KDP (potassium dihydrogen phosphate) crystals. The polishing liquid is composed of an oil phase, a dispersed phase solvent, acidic ionic liquid (AIL), a surfactant and a cosurfactant; under the action of the surfactant and cosurfactant, an AIL solution is wrapped in the oil phase as a dispersed phase, and an oil-package acidic-ionic-liquid microemulsion (AIL / O) is formed; during chemical-mechanical polishing, the AIL / O microemulsion is extruded and rubbed, AIL molecules break through an interfacial film to reach surfaces of the crystals and generate chemical reaction with surface bulges, and selective removal of the surfaces is realized; the AIL / O polishing liquid for the KDP crystals is simple in preparation and stable in property, reaction characteristics and chemical-mechanical technology of the KDP crystals are considered comprehensively; the polishing liquid has the advantages of both high selectivity in deliquescence polishing and organic acid / alkali corrosion polishing of the KDP crystals, flying-cut blade grains can be effectively weakened, surface roughness is lowered, and no residue is remained on the surface.

Description

technical field [0001] The invention belongs to the cross-application field of ultra-precision machining and synthesis of functionalized microemulsions, and in particular relates to an acidic ionic liquid in oil polishing liquid for KDP crystals. Background technique [0002] Potassium dihydrogen phosphate (KDP) crystal is a very good optical crystal developed in the 1940s. It is the only non-conductive material that can be used for laser frequency doubling, electro-optic modulation and photoelectric switching devices in optical systems such as ICF and strong laser weapons. Linear Optical Materials. In engineering applications, the surface quality requirements of KDP crystals are extremely high, such as ultra-smoothness, no surface defects, no stress residues, and no impurity residues, which are close to the limit of material processing. However, the KDP crystal material itself has the characteristics of soft and brittle, easy to deliquescence, sensitive to temperature chan...

AI Technical Summary

Problems solved by technology

However, due to the strong deliquescence effect of water on the KDP crystal, the removal rate of the deliquescence micro-area on the crystal surface is uncontrollable during polishing, and small corrosion pits are easily generated on the surface, and the fineness of polishing removal is low.

The defects of the deliquescent polishing method based on the microemulsion are mainly attributed to: (1) Although the size of the water nuclei in the W / O microemulsion is at the nanometer level, the strength of the deliquescent effect of each water nuclei on the KDP crystal is uncontrollable, and in During the CMP process, due to the participation of mechanical action, the intensity of deliquescent action in the micro-area will be further enlarged, which will eventually lead to the difficulty in controlling the precision of chemical mechanical removal. The removal rate can only be controlled at the level of hundreds of nanometers. Processing is difficult to achieve

(2) Deliquescence forms KDP aqueous solution on the surface of KDP crystal crystal. Since the solubility of KDP aqueous solution in organic solvent (oil phase) is very low, residue and recrystallization will inevitably occur on the surface of KDP crystal, resulting in residual KDP microcrystals on the surface , affecting the surface quality

[0006] From the above analysis, it can be seen that chemical mechanical polishing technology is theoretically expected to achieve the goal of ultra-smooth and ultra-clean surface processing of KDP crystals. The problem