Key Engineering Materials Vols. 291-292

Abstract: This paper carried out some experimentation and verification of the chemical vapor deposition induced ion beam and sputtering using the SMI8800 manufactured by SEIKO. FIB-CVD is very useful tools to repair the mask or IC with sub-micrometer precision. However it need to be much studied in some fields such as FIB-CVD mechanism and the characteristics of pattern accuracy and yield of CVD according to many parameters related to ion beam, beam scanning methods and type of specimen etc. Therefore the verification on FIB-CVD characteristic such as accuracy and yield according to scanning area and scanning time is carried out in this study. And it suggests the optimization parameters, various mechanisms of the chemical vapor deposition induced ion beam and sputtering effect for simple pattern.

Abstract: Recently, the research of the gene using the transgenic mouse has been performed for the development of new medicines. However, 600,000 kinds of mice are produced for the elucidation of each gene function. For this reason, the intelligent microchips have been developed to obtain an individual identification and biological information. The ventricular rate of a mouse can be monitored by the micro pressure sensor mounted on the intelligent microchip. In this research, the detailed structure and functions of the micro pressure sensor were investigated by the FEM analysis, and the sensor-chips were manufactured on 6-inch silicon wafer. The wafer thickness had to be reduced owing to the size restriction of the intelligent microchip. The grinding of the 6-inch silicon wafer with 560 µm in thickness with 19200 sensor-chips was carried out by the newly developed thinning technology. After the basic characteristics of a sensor-chip were evaluated, the output profile containing small peaks corresponding to the heartbeat of a transgenic mouse was finally detected using a mounted sensor-chip.

Abstract: Wafer rotation grinding, as an important processing technology, is widely used in manufacturing and back thinning of the silicon wafer. However, the surface/subsurface integrity of the ground wafer, which has important influences on the surface quality and the output of the wafer in subsequent process, is becoming an attention-catching problem. This study is aimed at experimental investigation of the surface/subsurface integrity in wafer rotation grinding. The surface roughness, the subsurface crack configurations, the subsurface damage depth (SSD) and the phase transformations are evaluated by corresponding methods. The results show that the integrity of the ground wafer has a close relationship with the grit size of the grinding wheel. The surface roughness and the SSD increase with increasing of the grit size. The subsurface crack configurations of (100) silicon wafers are complicated. The material removal mechanism is different under different grinding conditions. Ductile grinding is accompanied by the phase transformations of diamond structure silicon (Si-I). The amorphous silicon (α-Si), the Si-XII phase (r8-rhombohedral structure) and the Si-III phase (bc8-body-centered cubic structure) exist on the near surface region of the wafer ground by #600 and #2000 grinding wheels.

Abstract: MQL (Minimum Quantity Lubrication) technology was applied to finish-turning of a nickel base superalloy, Inconel 718, with a PVD coated carbide tool with a super lattice coating of TiN/AlN. Cutting lubricant used for MQL was a biodegradable synthesis ester, which was supplied to the cutting point with compressed air from the both sides of flank and rake faces of the tool. At a cutting speed of 1.0 m/s and an air supply pressure of 0.4 MPa, MQL cutting showed longer tool life and better surface finish than both the dry cutting and wet cutting. When increasing the pressure of the air supply from 0.40 MPa to 0.60 MPa, however, the corner wear, the most predominant wear in all the cutting conditions in this study, increased. When the cutting speed was increased to 1.5 m/s, the tool life in MQL decreased drastically. These results suggested that when finishing Inconel 718, the special care must be taken for choosing the pressure of air supply and cutting speed. The obtained results provided a useful understanding of the complicated influence of MQL on the cutting performance of Inconel 718.

Abstract: High speed milling is widely employed in die and mold machining, and the attentions had been gradually paid on the details during the process. Based on the high-speed milling experiments of hardened steel with different extended length of tool, cutting force, cutting vibration, tool wear and surface roughness were measured and analyzed in this paper. It was founded that cutting force and vibration were not increasing straightly with the addition of extended length, but fell down when exceeded a certain value, and the surface quality improved at same time.

Abstract: The drilling assisted by ultrasonic elliptical vibration (UEV) is proposed in present paper. The drilling system assisted by UEV was developed. The characteristics of the drilling process assisted by UEV are analyzed. The effect of ultrasonic elliptical vibration on the axial drilling force, the radial drilling force and the chip thickness are investigated experimentally. The experimental results show that the axial drilling force, the variation of the radial drilling force and the chip thickness of drilling assisted by UEV can be reduced.

Abstract: Metal matrix composites（MMCs）is applied widely in recent years because of its excellent performances, but the machining is very difficult due to the rigidity of reinforced-phase in it, so, the application of MMCs is restricted much. In this paper the experiment of common and ultrasonic vibration drilling is performed to SiC particulate reinforced Al matrix composites （SiCp/Al）by use of carbide-alloy-twist-drill, and the surface roughness of hole is compared, furthermore, the wearing of twist drill and the feature of chips are analyzed by scanning electron microscope (SEM). From above, we can draw aconclusion that ultrasonic vibration drilling may meliorate the mechanism of drilling to some extent and it takes on much superiority that the common drilling is unmatched, so this method could provide a certain foundation for the posterior study and application.

Abstract: The cutting performance in abrasive waterjet (AWJ) multipass cutting with and without controlled nozzle oscillation is presented based on an experimental investigation cutting an 87% alumina ceramic. The cutting capacity in terms of the depth of cut and the kerf geometrical features is analyzed with respect to the process variables. It is found that multipass cutting is a viable means to increase the cutting performance and application domain of this technology, while a further increase in the cutting performance can be made by using a controlled nozzle oscillation technique.

Abstract: Predictive models for the particle velocity in an abrasive waterjet (AWJ) are developed following a CFD (computational fluid dynamics) study. A numerical study is then carried out to assess the models. It is shown that the predictive models can adequately predict this particle characteristic in an AWJ.

Abstract: Composite materials are used for many structures because of its high strong-to-weight ratio and easy formation. Secondary machining processes such as drilling and sawing are required to assemble and join composite materials to other structures. When composite materials are machined, delamination occurs at adhesive layer between laminated layers. It is well known that it is possible to cut hard metals and to improve precision of machined surface by using ultrasonic vibration. This method is applied to machining composite materials in this paper. Drilling of composite materials is focused on. First, this method is examined experimentally. Next, experimental results are examined by analytical method. Using condition of experiment, prevention of delamination can be demonstrated from the proposed analytical method.