In this study, the CVD diamond films were grinded using composite electroplating in-process sharpening (CEPIS). At an applied load of 4.2 kg, a rotation speed of 200 rpm and 20 rpm for the upper and lower spindles, the effects of NiCl2 (nickel chloride) content of electrolyte (in the range of 5-75 g/l) and cathode current density (in the range of 0-7.5 ASD) on the structure of the nickel-diamond composite coating and its grinding ability were investigated. Based on the experiment results, the coating structure became porous and the coating thickness increased with decreasing NiCl2 content of electrolyte during the composite electroplating process. During CEPIS process, the material removal rate of diamond film has no obvious concern with the NiCl2 content at low cathode current density (below 2.5 ASD). However, its material removal rate rapidly increased to a saturated value with increasing NiCl2 content at high cathode current density (above 5 ASD). The NiCl2 content to achieve a saturated material removal rate increased with increasing cathode current density. In this study, the maximum removal rate of diamond film is about 0.093 mg/min at the NiCl2 content of 75 g/l and the cathode current density of 5 ASD.

ABSTRACT The polishing stocks used in various ultra-precision polishing machines consist of abrasives, polishing disk (pad), and polishing fluids. They are expendable goods. To ensure the machining ability and the repeat accuracy of machining characteristics, the polishing disc (pad) must use the dressing mechanism to produce sharp new grains. As a result, the grinding surface on the abrasive wheel becomes thinner gradually, then losses it¡¦s machining ability, and finally must be changed. Hence, in this project, an idea of an ultra-precision abrasive machining is proposed by using the continuous composite electroplating on the polishing disc. In this idea, the machining ability of Cu polishing disc can be ensured due to the use of the continuous Sn-Al2O3 composite electroplating. Hence, it can save the cost of the ultra-precision machining using in the semiconductor wafer. In this study, after 60 minutes continuous composite electroplated polishing, the thickness of the composite coating on the surface of Cu polishing disc can increase 6.13£gm. It means the surface of disc can be grew and renewed at every moment. The removal amount of the wafer is 10.8£gm. The surface of wafer was Ra=0.5453£gm and Rmax=5.464£gm at the start ,but came to Ra=0.0019£gm and Planess=2.649£gm/36mm after 60 minutes polishing.