Development of Flexible Polishing Method Using Magnetic Slurry: Effect of Movable Parmanent Magnet on Polishing Characteristics

摘要

Magnetic field-assisted fine polishing method has been proposed, which uses a magnetic slurry mixed non-ferrous abrasives into a magnetic fluid. Polishing machine has newly been developed which is consisted both of copper rotary disc set a strong permanent magnet and a rotary shaft set similar one, it is mounted a specimen to be polished. Magnetic field strength controlled by moving their magnets is responsible for yielding superior surface quality. It is found that polishing machine has high performance finishing ability and the usage of a variety of magnetic fluid is proposed versatile polishing characteristics. Experiments show that kerosene based magnetic fluid has very high polishing performance compared with water based one. The usage of coarse grain gives rise to increase the surface roughnes, and larger clearance between specimen and copper rotary disc lowers finishing rate of wafer in kerosene based magnetic fluid especially. Movement of permanent magnet in copper rotary disc is very effective for finishing of wafer.