In the lapping process, the actions of the slurry affect lapping efficiency and lapping accuracy of wafers. However, it is not possible to observe the actions of the slurry on the lapping plate. In this study, therefore, an acrylic plate was used instead of the upper plate, and the actions of the slurry at the processing part were visualized using a high-speed camera. In addition, a supply method using a combination of three tube diameters was used to produce air bubbles in the slurry. The results indicated that the flow rate of the slurry including air bubbles on the lapping plate was double that of normal slurry, and the air bubbles in the slurry did not enter the processing part.

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We have developed a polishing pad using materials with different wear rates to achieve highly efficient polishing of difficult-to-process material substrates. Nylon fibers with good mechanical properties are arranged with other materials, followed by dressing to form protrusions on the polishing pad surface. Stable polishing performance can be expected if the orientation and arrangement of the nylon fibers can be controlled. A sapphire substrate was polished using the prototype polishing pad developed in this research. The results indicated 30% improvement in material removal rate compared to the ready-made pad.

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