A preparation method of silicon-aluminum composite abrasive for sapphire substrate polishing

Abstract

The invention discloses a preparation method of a silicon-aluminum abrasive compound for sapphire substrate polishing. The preparation method comprises the following steps: firstly, uniformly dispersing a certain amount of a hydrophilic silane coupling agent and a commercial aluminum oxide powder in an aqueous solvent sequentially, regulating the pH value (potential of hydrogen) of a dispersing liquid to be alkaline with a pH (potential of hydrogen) regulator, heating the dispersing liquid to a specific temperature, continuously adding a silicon source diluent prepared in advanced into the dispersing liquid under the conditions of mechanical stirring and a constant temperature, at the same time, supplementing a corresponding amount of alkali stabilizer to avoid unstability of a reaction system, after adding a silicon source, continuing to keep the temperature for 30min, then stopping heating, cooling to a room temperature and obtaining the silicon-aluminum abrasive compound for the polishing. The silicon-aluminum abrasive compound prepared by the method has good suspension dispersion stability and liquidity and a high removal speed of a sapphire material; the surface of a chip is free from scratch and good in smoothness; the silicon-aluminum abrasive compound is applicable to the chemical and mechanical polishing of a sapphire substrate.

Description

technical field [0001] The invention belongs to the fields of inorganic abrasive preparation and chemical mechanical polishing, and in particular relates to a preparation method of silicon-aluminum composite abrasive used for polishing sapphire substrates. Background technique [0002] Sapphire is a single crystal aluminum oxide (Al 2 o 3 ), has excellent mechanical, optical and chemical properties, and integrates many advantages such as high temperature resistance, scratch resistance, non-reflection, corrosion resistance, etc., and can be widely used in consumer electronics, automobiles, smart homes, semiconductors, lasers, microwave components , aerospace and other civil and military fields. Among them, as the substrate material of LED chips, sapphire occupies more than 95% of the market share of this application due to its relatively mature technology and relatively low cost. Since the outbreak of LED backlighting in 2009 and the LED lighting application market in 2013...

AI Technical Summary

Problems solved by technology

Chinese invention patent (patent number: ZL201410255977) discloses a method for making a silicon-aluminum composite polishing fluid. Since the composite abrasive used in the polishing fluid is a simple physical mixture of alumina and silicon oxide abrasives, it is not effective. Inhibits scratches on the surface of sapphire wafers caused by alumina particles

Another Chinese invention patent (patent number: ZL200610026974) discloses a method for preparing alumina / silica composite abrasive grains, since the preparation of the composite abrasive grains uses Na 2 SiO 3 As a silicon source, the content of Na ions in the reaction system is too high, resulting in the self-nucleation and flocculation of part of the silica. Therefore, the prepared composite abrasive grains are essentially a mixture of alumina and silica particles, and thus cannot effectively inhibit the formation of alumina particles. Scratches caused by particles on the surface of sapphire wafers

In addition, the introduction of impurity ions also increases the subsequent centrifugal separation, purification, drying and other multi-processing processes, which is not conducive to large-scale production and the redispersion of composite abrasive particles in subsequent use is not easy to maintain suspension stability

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