Mono-crystalline and nano-polycrystalline diamond tools are used to perform micro V-groove face turning of cobalt-free tungsten carbide. The tool wear ratio, defined as tool edge wear length/total cutting length, with the nano-polycrystalline diamond tool was 50% smaller than that with mono-crystalline diamond tool. Cleavage due to large chips was mainly observed at the cutting edge of the mono-crystalline diamond tool; abrasive wear and small chips were mainly observed with the nano-polycrystalline diamond tool.

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CNx is nitrogen-containing Diamond-Like Carbon (DLC) and has excellent mechanical properties, such as high hardness and very low friction coefficient. An investigation was carried out on the effects of sputtering gas on film structures and mechanical properties for preparation of CNx films by RF reactive sputtering. The film structures were analyzed by SEM, XPS, and Raman spectroscopy. The mechanical properties were measured by nano-indentation test. The deposition rate of CNx films was increased by adding nitrogen gas to Ar using a floating substrate holder. However, the hardness was decreased by adding nitrogen gas to Ar. Nano-indentation test indicated that the hardness was decreased by using a mixture of Ar-N₂ gases and floating substrate holder.

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Chemical mechanical planarization/polishing (CMP) is generally used for planarization of Si wafer substrates for semiconductor devices. In CMP, the removal rate decreases with increasing polishing time due to deterioration of the pad surface asperity. Further, the removal rate increases with increasing slurry particle concentration. However, the relationships between the removal rate and other polishing parameters and various phenomena have not been discussed sufficiently. Here, we analyze the effects of various parameters on the removal rate of Si-CMP. In particular, we discuss the relationship between the removal rate and the following parameters: pad surface asperity, vibration acceleration of the polishing head, coefficient of friction, and pad surface temperature. We clarify the effects of each parameters on the removal rate. The results indicated that the removal rate decreases with increasing polishing head vibration. Moreover, the removal rate was proportional to the coefficient of friction and the pad temperature, however, this trend was markedly affected by the slurry particle concentration.

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The utility of slanting-hole drilling using an electroplated diamond tool of small-diameter devised by the authors was investigated. As with straight-hole drilling, a normal drilling cycle could be adopted with slanting-hole drilling because the unique shape of the tool increases chip discharge. In addition, the drilled hole showed a small degree of chipping without using an underlay board and/or ultrasonic wave instrument. The chipping width was influenced by the behavior of the axial component of the grinding force before completion of the drilling process.

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