Study On Vibration Field Of Ultra-Smooth Surface Polishing Based On Liquid Two-Dimension Vibration And Experiment Research

With the development of microelectronics and optics, the requirement for the surface precision of key components is increasingly stricter. In recent years the scale of the integrate circuit become larger and larger, the feature size of wafer has become much smaller, to guarantee the quality in following process, the demand to surface precision of wafer is very serious. In modern shortwave optics and highlight optics systems, it is very severe for the surface precision of components, the surface roughness is demanded to be very low and without any surface damage. In other fields of technology, such as high dense magnetism record component and light record component, the ultra-smooth surface is also necessary.In this paper, a novel polishing technique based on the two-dimension vibration of fluid is put forward. It uses a liquid to replace a polishing pad and supply two-dimension high-frequency vibration as a power of polishing. Under the two-dimensional vibration, the fluid and abrasives impact workpiece continuously. The material can be removed by the physical-chemical action between slurry and workpiece, and the ultra-smooth surface can be obtained. Based on this way, an experimental equipment has been designed and harmonic analysis are done with finite element method. According to Mode analysis, the nature frequency and vibration mode are obtained. The frequency of vibration is found from harmonic analysis, at which the respond of trough to vibration exciter is best.In polishing, the vibration state of fluid field and the way that workpiece is fixed has important effect on surface quality. It is observered that, in a stable fluid field, when workpiece is fixed flatly in polishing, some flaws such as concaves are found. However, when workpiece is fixed vertically, the smooth surface is obtained. In a unstable fluid field, some flaws such as concaves are found when workpiece are fixed flatly and vertically respectively. Region-track measure method is employed to evaluate the polishing result, and some polishing rules are presented.