Papers by Author: Ryunosuke Sato

Abstract: A series of polishing experiments have been carried out using Mn2O3 as abrasive grains to examine the polishing characteristics of CMP for oxygen-free copper. It has been found that the polishing rate increases as the polishing speed and/or polishing pressure increases, also the role of polishing speed on the polishing rate is more significant than that of the polishing pressure. The effects of the polishing conditions are however small, when polishing a finished surface roughness of about Ra 5 nm. A long polishing time, with an approximately constant polishing rate, can be achieved, without dressing, with a polishing pressure P = 9.4 kPa. It was found that higher polishing pressures could achieve a higher polishing rate, however the polishing pressure would decrease as the polishing time increased.

Abstract: This paper presents a fractal analysis of the self-sharpening phenomenon of the grain cutting edges in cBN grinding. To clarify the self-sharpening mechanism due to the micro fracture of the cutting edges, the changes in three-dimensional profile of the cutting edges in the grinding process have been measured using a scanning electron microscope with four electron probes and evaluated on the basis of the fractal analysis. The fractal dimension for surface profile of the cutting edge formed by the micro fracture is higher than that of the cutting edge formed by the ductile attritious wear. Therefore, the complicated changes in shape of the cutting edge due to the self-sharpening can be evaluated quantitatively using the fractal dimension.