Fixed abrasive polishing technology can obtain a nanoscale surface and is one of the future nano machining directions. The coefficient of friction between the pad and the wafer in the polishing process can influence on the surface quality of the wafer. The relationship between the coefficient of friction and surface roughness of the wafer was investigated to improve the efficiency and surface quality. Based on the Florida model, the adhesion, asperity plough and abrasive plough from the pad in the polishing process was analyzed. The friction force per unit area was calculated by the properties of the pad and wafer. Based on the rod model, the actual contact area was calculated by the surface roughness and the properties of the pad and wafer. The relational model between the surface roughness of the wafer and the friction coefficient was established. The model was verified by the experiments of fixed abrasive polishing of BK7 glass. When the friction coefficient is less than 1.9, the data of the experiment and theory match very well in the comparison process.
Chemical vapor deposition (CVD) diamond film has broad application prospect as heat sink in microelectronic field for its excellent thermal conductivity. The micro CVD diamond heat sinks with the size of 50μm×100μm×2000μm were prepared using mould copy technique. The micro silicon moulds for deposition of micro CVD diamond heat sinks were fabricated using inductivity coupling plasma (ICP) etching process. Micro CVD diamond heat sinks were synthesized under 2% methane and 98% hydrogen by hot filament CVD (HFCVD) method. The micro CVD diamond heat sinks were investigated by SEM, Raman and photo thermal deflection. The results show that favorable micro CVD heat sinks having a thermal conductivity of 960W·m-1·K-1 can be prepared by mould copy technique.
The mechanical properties of carbon fiber reinforced resin composites (CFRP) including the epoxy matrix, the carbon fiber and the interface of the carbon fiber/epoxy composites were investigated by means of nanoindentation technique. The hardness, Young’s modulus of the components in CFRP were obtained. The results show that the hardness and Young’s modulus have a gradient variation from the epoxy matrix to carbon fiber.