Basic Research On Polishing Performance Of Fixed-abrasive Polishing Pad With Ice Particles

In recent years, with the development of production and technology, the use of the hard-brittle crystal particularly semiconductor material is becoming more and more widespread in electronics, optics, instrumentation and many other fields. Chemical mechanical polishing is the most commonly method in ultra-precision machining of the hard-brittle crystal currently. Chemical mechanical polishing with free abrasives exist some shortcomings during the polishing, such as larger workpiece deformation, lower working efficiency. Based on this background, the technology of using fixed-abrasive polishing pad with ice particles for processing quality hard-brittle materials high was innovatively proposed. A serial of researches were carried out on the design and polishing property validation for fixed-abrasive polishing pad with ice particles. This work can provide a new polishing tool for ultra-precision machining of the hard-brittle crystal. The main work and results are as follows:1. Dispersion technology for micron and nanometer α-Al2O3 in water suspension. Mechanical dispersion and chemical dispersion was combined for the dispersion, and the influence of milling time, ultrasonic time, dispersant type, dispersant concentration and pH value on dispersion and stability of micron and nanometer α-Al2O3 in water suspension was analyzed. The optimum conditions for preparing stability polishing solution were discussed. The above work can guide to obtain polishing solution with high performance.2. The thermal physical properties and mechanical performance of ice were discussed, and homogeneous nucleation and heterogeneous nucleation ways of nucleation process were analyzed and calculated. The fundamental researches on ice crystals generating was investigated. The above work can provide a theoretical basis for preparing the fixed-abrasive polishing pad with ice particles.3. Based on the analysis of heat transfer in polishing solution freezing process, the rapid ice particles preparation system was designed and the fixed-abrasive polishing pad with ice particles was successfully prepared. Compared with fixed abrasive polishing pad under the same conditions, performance verification test of polishing germanium wafer was carried out, using fixed-abrasive polishing pad with ice particles, which proved theg fixed-abrasive polishing pad with ice particles can improve polishing efficiency and surface quality effectively.