The research of high-quality grinding technology of large-size Al2O3 single-crystal slice
Al<inf>2</inf>O<inf>3</inf> single crystal has the following unique physical properties of high hardness, high toughness, obvious pleochroism and high refractive index Etc. The paper introduced the processing property of Al<inf>2</inf>O<inf>3</inf> single crystal, described its grinding technology. Then analyzed the characteristics and status of grinding technology of the large-sized Al<inf>2</inf>O<inf>3</inf> single crystal, combined with the relational research, discussed the technology of the grinding stage. Finally the paper summarized a set of precise grinding technology of large-sized Al<inf>2</inf>O<inf>3</inf> slice.
ELID grinding of silicon wafers: A literature review
Silicon wafers are the most widely used substrates for fabricating integrated circuits. There have been continuous demands for higher quality silicon wafers with lower prices, and it becomes more and more difficult to meet these demands using current manufacturing processes. In recent years, research has been done on electrolytic in-process dressing (ELID) grinding of silicon wafers to explore its potential to become a viable manufacturing process. This paper reviews the literature on ELID grinding, covering its set-ups, wheel dressing mechanism, and experimental results. It also discusses the technical barriers that have to be overcome before ELID grinding can be used in manufacturing.
Synthesis and chemical recycling of novel poly(ester-urethane)s using an enzyme.
A series of enzymatically recyclable poly(ester-urethane)s consisting of a biodegradable diurethane moiety as a hard segment and an ester moiety as an enzymatically cleavable linkage was chemo-enzymatically prepared by two routes. The poly(ester-urethane) was prepared by a) the ring-opening polymerization of a cyclic ester-urethane monomer synthesized via the transesterification reaction of biodegradable diurethanediol and dicarboxylate ester using lipase and b) the direct polycondensation of a diurethanediol and a dicarboxylate ester. A significantly higher molecular-weight poly(ester-urethane) having the highest molecular weight (Mw) of 101,000 was produced by the ring-opening polymerization of the cyclic ester-urethane monomer when compared with that produced by the polycondensation of the dicarboxylate ester with diurethanediol. The poly(ester-urethane) was readily degraded by lipase into the corresponding cyclic oligomers; the oligomers were readily repolymerized by the ring-opening polymerization using lipase for chemical recycling.