| QIU Zhao-hui,JIANG Bo,LU Kun-quan,SHEN Rong,XIONG Xiao-min.Nano-conductor Dominated Giant Electrorheological Polishing Fluid and Its Application to Silicon Materials[J],52(5):218-225 |
| Nano-conductor Dominated Giant Electrorheological Polishing Fluid and Its Application to Silicon Materials |
| |
| View Full Text View/Add Comment Download reader |
| DOI：10.16490/j.cnki.issn.1001-3660.2023.05.021 |
| KeyWord:nano-conductor dominated electrorheological fluid shear strength electrorheological polishing silicon wafer surface roughness |
| Author | Institution |
| QIU Zhao-hui |
School of Physics,Guangzhou , China |
| JIANG Bo |
School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou , China |
| LU Kun-quan |
Institute of Physics, Chinese Academy of Sciences, Beijing , China |
| SHEN Rong |
Institute of Physics, Chinese Academy of Sciences, Beijing , China |
| XIONG Xiao-min |
School of Physics,Guangzhou , China |
|
| Hits: |
| Download times: |
| Abstract: |
| The work aims to overcome the limitations of low intensity and short lifetime of existing electroheological (ER) polishing fluid under the electric field. The defects of the existing ER polishing fluid were analyzed to remedy them by putting forward the idea of applying a novel giant ER fluid based on dielectric particles inlaid with conductor clusters to the polishing field. The novel giant ER fluid consisted of dielectric particles inlaid with nano-conductor clusters and isolating oil, the effect of which was the result of the strong interaction generated by the conductor nanoclusters in the process of inducing dipole moments in the electric field. Due to the stable combination of dielectric particles and conductor nanoclusters, the fluid could withstand the long-lasting friction and temperature changes. Therefore, its advantages of larger shear strength and long lifetime, made it suitable for being an ER polishing fluid. This research developed a silicon-oil based ER polishing fluid using TiO2 inlaid with nano-carbon as dielectric particles and SiO2 as abrasive. The basic principle of the ER polishing was that the ER particles in the fluid formed a chain or column structure under the influence of electric field, enveloping abrasive particles and becoming a flexible polishing head. When the head moved, the abrasive exerted a micro cutting effect on the surface of workpiece so as to achieve the purpose of polishing. During the study, the dissertation determined the relationships between the shear strength of polishing fluid added with abrasives of different particle sizes (2 μm, 200 nm, 20 nm) and electric field that was under different strength and temperatures. A simple rotary electrostatic polishing device was set up to carry out trials on the polishing effect of ER fluids with abrasives of different particle sizes. The electrodes were made up of two paralleled copper sheets which were 3 mm thick and 10 mm in both length and width. The gap between the electrodes was 1 mm wide. By applying a high voltage on the copper sheets, the shear strength of ER polishing fluid which was between and at the top of the copper sheets increased and would form a flexible polishing head. When the tool rotated, the head performed the polishing work on the workpiece. During the polishing process, the gap between the copper electrode and workpiece was 0.3 mm in width and the voltage between electrodes was 2.5 kV. The study showed that the newly developed ER polishing fluid had advantages such as high shear strength (>30 kPa), small leakage current (<1 μA), stability under high temperature (25-125 ℃), a long service life and insensitivity to small amounts of abrasives. The polishing experiment result revealed that the roughness of the silicon wafer dropped from 206 nm to 6.4 nm after being ground by the ER polishing fluid added with a 2 μm abrasive. The roughness of the silicon wafer then dropped to 0.46 nm after being polished by the fluid with a 200 nm abrasive while the roughness dropped to 0.36 nm after being polished by the fluid with a 20 nm abrasive. It is shown in this thesis that the new novel giant ER fluid can effectively reduce the surface thickness, improve the surface quality, and can be well applied to precision polishing, showing a good application prospect. |
| Close |
|
|
|