To solve the problem that ultrafine diamond powder polishing disc using hot pressing method is easy to produce deep scratch on the surface of SiC wafer, a preparation method of ultrafine diamond powder fixed abrasive polishing disc based on polyvinyl alcohol freezing and thawing gel-forming mechanism is proposed. The properties of the gel polishing disc were characterized by mechanical property tests, infrared spectrum, friction wear and thermogravimetric analysis. The results show that when the polyvinyl alcohol content is greater than 3wt%, the polyvinyl alcohol-phenolic resin mixed glue can form a complete gel. When the polyvinyl alcohol content is 5wt%-6wt%, a large number of capillary micropores are formed in the gel polishing disc, the pores are interlaced and interlinked, the gel polishing disc has the highest flexural strength and tensile strength, the highest average friction coefficient, and the best stability of friction coefficient, the uniformity of abrasives is better than that of the hot pressing polishing disc. With the increase of polyvinyl alcohol content, the surface of the gel polishing disc is covered by resin bond, and the plasticity of the gel polishing disc becomes larger, the effect of polyvinyl alcohol pyrolysis on the friction coefficient of the gel polishing disc increases, and the friction coefficient begins to reduce with the increase of friction time. The polishing contrast experiment showed that when the SiC wafer was polished by the gel polishing disc with a polyvinyl alcohol content of 5wt%, the average surface roughness Ra less than 2.5 nm was obtained. After the next chemical mechanical polishing (CMP) process, the surface roughness Ra less than 0.5 nm was obtained, and the polishing effect was better than that of the hot pressing polishing disc. © 2022, Materials Review Magazine. All right reserved.
