Ultra-precision grinding of 4H-SiC wafer by PAV/PF composite sol-gel diamond wheel. (September 2021)

• Record Type: Journal Article
• Authors: Feng, Kaiping; Zhao, Tianchen; Lyu, Binghai; Zhou, Zhaozhong
• Is Part Of: Advances in mechanical engineering. Volume 13:Number 9(2021)
• Publication Date: 2021-09
• Subjects: Sol-gel diamond wheel -- 4H-SiC wafer -- ultra-precision grinding -- surface roughness -- abrasion; Mechanical engineering -- Periodicals; 621.05
• DOI: 10.1177/16878140211044929
• Languages: English
• ISSNs: 1687-8132

Abstract

To eliminate the deep scratches on the 4H-SiC wafer surface in the grinding process, a PVA/PF composite sol-gel diamond wheel was proposed. Diamond and fillers are sheared and dispersed in the polyvinyl alcohol-phenolic resin composite sol glue, repeatedly frozen at a low temperature of −20°C to gel, then 180°C sintering to obtain the diamond wheel. Study shows that the molecular chain of polyvinyl alcohol-phenolic resin is physically cross-linked to form gel under low-temperature conditions. Tested by mechanical property testing machines, microhardness tester, and SEM. The results show that micromorphology is more uniform, the strength of the sol-gel diamond wheel is higher, the hardness uniformity is better than that of the hot pressing diamond wheel. Grinding experiments of 4H-SiC wafer were carried out with the prepared sol-gel diamond wheel. The influence of grinding speed, feed rate, and grinding depth on the surface roughness was investigated. The results showed that by using the sol-gel diamond wheel, the surface quality of 4H-SiC wafer with an average surface roughness Ra 6.42 nm was obtained under grinding wheel speed 7000 r/min, grinding feed rate 6 µm/min, and grinding depth 15 µm, the surface quality was better than that of using hot pressing diamond wheel.