In this study, the authors investigated to improve the cutting performance of the milling process using a small-diameter ball-nosed end mill. The problems associated with this milling process are as follows: First, the shape accuracy and surface integrity of products and the tool life can easily be rendered inferior because of the occurrence of bending or vibration of the end mill owing to low rigidity of the tool. Second, a high level of surface roughness of the surface cut by the center web of the and mill can easily occur, because the cutting capacity of this cutting edge is poor and the cutting speed is low. In an effort to solve these problems, the authors investigate a countermeasure in which ultrasonic vibration is applied during end milling process. As results, bending of the small-diameter end mill is prevented, the shape accuracy and surface integrity of products are improved, and also the tool life is lengthened by ultrasonic end milling in which the end mill is axially vibrated with ultrasonic frequency. Thus, it is believed that ultrasonic-vibration milling is effective in the improvement of the cutting performance of the milling process using the small-diameter ball-nosed end mill.

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This paper describes a new method for micro-EDM drilling which utilizes the wear of an electrode rod. In this method, the polality of the electrode rod is positive, and the rotating electrode rod is fed into the block electrode at a feed rate of several tens times higher than the normal one. Since the circumferential region of the electrode rod wears at a much higher rate than the central region, the end of the electrode rod is sharpened in a few minutes. At the same time, a cone-like micro-hole with a sharp bottom shape is generated in the electrode block automatically. Other results obtained are as follows: 1) In order to obtain longer needle shape, the optimal feed speed is 60pm/s. 2) With the increase of the discharge energy, the needle-shape becomes longer and thinner. 3) The needle-shape becomes longer and thinner with increasing the rotation speed.

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An automated scraping system with a machine tool and an image processing system has been developed in previous studies. In order to use the system as a highly precise and efficient system, it is necessary to intellectualize the scraping system like a skilful worker. This paper describes an investigation (digitalization) of a scraping operation by a skilful worker so that future studies can achieve effective and intelligent scraping system by means of the digitalized operation. In each step of the scraping operation, an image of the scraped workpiece with black bearing was obtained by a digital camera with a contrivance of imaging method and the information of the black bearing was obtained by image processing from the image. Moreover, a 3-D shape data of the workpiece was measured by a laser displacement meter on a machine tool. In the evaluation of the scraping operation, a height histogram of a 3-D shape data is useful. As a result, a strategy for smart and intelligent scraping was guessed from the investigation.

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In order to achieve a high efficiency and accuracy in slicing of hard and brittle materials, a work rotating type multi-wire sawing method has been devised. Work rotating type multi-wire sawing is one of the most effective slicing methods for hard and brittle materials. However, this method has to fix a workpiece at the end of the slicing process. When a diameter of workpiece is large, this fixation becomes difficult. The main purpose of this study is to propose a newly developed bundled workpieces method. By this method, several workpieces are bundled up around a core material and fixation of workpiece becomes needless. This new method is expected to prevent the sliced wafers from scattering and to enable complete slicing. The work material used in this study is borosilicate glass. The main results obtained are as follows. (1) Work rotating type multi-wire sawing using the bundled workpieces method makes it possible to prevent the wafers from breaking off before the completion of slicing, and to prevent them from scattering. (2) Work rotating type multi-wire sawing using coated bundled workpieces makes it possible to stabilize the slicing performance. (3) Work rotating type multi-wire sawing using this method improves the slicing rate. (4) Slicing precision of the normal work rotating type multi-wire sawing and bundled workpieces method is the same grade.

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It is known that a high performance micro system for the medical treatment, biotechnology, and nanotechnology etc, become a system where the electric circuit and the sensor are integrated on flat surface and spherical surface etc. In the future, anisotropic etching for spherical single-crystal silicon can be a key technique in order to develop a higher performance micro system. This paper has investigated the result of microstructure fabrication in spherical single-crystal silicon by anisotropic etching, and proposed a selection indicator in the line direction of mask pattern (crystal orientation), which is corresponded to users.

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High speed dry turning is one of the most important themes in ecological manufacturing. But in conventional turning style, it is difficult to reduce cutting temperature because the cutting edge is contacted to the work-piece continuously. Then in mill-turning, high speed face milling is applied for machining of cylindrical parts, and it is possible to reduce cutting temperature by using high speed-interrupted-small depth cutting method so as high speed endmilling. In this study, we have made clear the ability of mill-turning, and optimum cutting conditions for tool life. So we developed the prototype cutters for mill-turning, and tested their performance

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The present paper proposes a new "oblique" type of elliptical vibration cutting, while the previous method is distinguished as an "orthogonal" type. The oblique type of elliptical vibration cutting is technically similar to the orthogonal type proposed previously by the present authors, but its machining principle and features are different from the previous orthogonal type. A simple analytical model of the oblique type of elliptical vibration cutting process is developed to understand its mechanics by employing the simple maximum shear stress principle. Fundamental cutting experiments are carried out by the oblique and orthogonal types of elliptical vibration cutting and the ordinary cutting, and it is confirmed that the simulation and the experiment are in a good agreement. The results show that the chip thickness, cutting force and burrs are reduced by the oblique type of elliptical vibration cutting as much as the orthogonal type, and that the oblique type is advantageous to obtain good surface finish at high vibration amplitude compared with the previous orthogonal type as the roughness due to the vibration is reduced by the obliquity.

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In order to clarify the effect of target materials on the reactive sputtering process, we have characterized the hysteresis behavior of four kinds of target materials, Ti, Nb, Cr and Al. When highly reactive metals such as Ti and Nb were used as target, the hysteresis behavior appeared very clearly. On the other hand, the hysteresis became unclear when a low reactive metal such as Al was used. The hysteresis of Cr target was very small though the reactivity of Cr was not so low. This is attributed that the difference of sputtering yield between Cr metal and Cr-N nitride is smaller than that of the other metal.
We have also investigated the optimum deposition conditions of sputtered Me-N films using the rf reactive sputtering apparatus equipped with a PEM (Plasma Emission Monitoring) control system for stabilizing the hysteresis behavior. The optimum condition for nitride films using highly reactive target metals such as Ti and Nb appeared to be near the unstable region of reactive sputtering process. The PEM system usedin the study was found to be very useful for depositing these nitride films. In the case of AIN films, the optimum condition was an excessive nitrogen partial pressure region. This difference in the optimum conditions is considered to be caused by the difference of reactivity of target metal and the stable metal-nitrogen alloy phase.

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This paper describes the research about the off-line production system's simulator connected Genetic Algorithm (GA) to realize a single part input into a variety production line. In this paper, a recurring individual is proposed. This simulator expresses parts input sequence as a recurring individual in GA and gives a crossover and a mutation not to change a goal production ratio for each part. The recurring individual has the characteristics efficiently to find the crossover point in the crossover operation of GA. The developed system was applied to the FTL model in a computer. As a result, the outputs by using the inputs parts sequence acquired by the developed system are 30 - 60 more than those of the conventional way.

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A final goal of this study is to measure the inner diameter at any point along a quadrilateral hole's wall with an error of less than ±0.2 μm by detecting the image of a small spot which is projected into the small hole and reflected onto its wall. In this report the measurement error of the gap inside the narrow quadrilateral hole is analyzed experimentally and the methods to decrease the error are discussed. Since it is very difficult to fabricate a precise quadrilateral hole, a specimen made with seven gauge blocks is developed and the thickness of the middle gauge block is measured. By this method, the accuracy of the quadrilateral hole gap measurement can be evaluated with an error of less than ±0.1μm without measuring the gap inside the hole. This experiment shows that the errors of the narrow quadrilateral hole gap measurement, such as a 0.3mm×0.3mm square hole, are large. As these errors seem to be caused by spherical aberration of the lens, the spherical aberration is measured experimentally. It is verified that the errors of the narrow quadrilateral hole gap measurement are caused by the spherical aberration of the lens because the spherical aberration is a defocus near the optical axis, which causes the gap measurement errors. Therefore, the gap measurement errors can be compensated by taking account of the measured spherical aberration of the objective lens in the narrow gap measurement.

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A wave-optical simulator was coded and applied to the predictions of reflected beam qualities such as profiles of intensity and wavefront phase. Reflected beam qualities of flat mirrors with artificial bumps, which were modeled by Gaussian functions having a height of 1nm and widths from 0.06mm to 54mm, are investigated in the case of relatively short distance from the mirror center to the observing point such around 1m-long. As a result, bumps with the widths around 1mm make high contrast interference fringes in the reflected beam. Simulated results are examined and confirmed to be in good agreements.

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A wave-optical simulator was coded and applied to the predictions of reflected beam qualities such as profiles of intensity and wavefront phase. Reflected beam qualities of flat mirrors with artificial bumps, which were modeled by Gaussian functions having a height of 1nm and widths from 0.06mm to 54mm, are investigated in the case of relatively short distance from the mirror center to the observing point such around 1m-long. As a result, bumps with the widths around 1mm make high contrast interference fringes in the reflected beam. Simulated results are examined and confirmed to be in good agreements.

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A Calibration method is discussed to improve the positioning accuracy with a planer multi-joint positioning system. A measurement system, which was constructed in the previous report to realize a measurement resolution of 1.2μm over the global range of 350×150mm, is used for the calibration. At first, the effect of the link length error on the positioning accuracy is considered analytically. It is clarified that the positioning error obtained in the previous report is caused mainly by the link length errors. Next, a method of calibrating the link length is discussed to improve the positioning accuracy. The equations are formulated to derive the link length from the positioning errors on arbitrarily selected three points. Because 32 points are given on the reference board for the measurement, ₃₂C₃=4960 different pairs of link lengths are obtained from the measured results. A method is proposed to determine statistically the optimum value of the link length from the 4960 pairs. The positioning experiment is performed again by using the calibrated link lengths. It is verified that the RMS value of the positioning bias errors decreases to 24μm that is equivalent to the positioning resolution of the system.

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Most optical styluses composed of laser diode and objective lens are troubled with signal noise when being traversed over machine tooled surfaces. The main cause of that signal noise can be attributed to laser speckle included in the reflected light from the object surface. It has been strongly required to decrease the influence of such speckle noise on the displacement signal of those optical styluses. In this study, a novel optical measurement system is proposed for a new optical stylus that has the speckle noise removal function. By using the newly developed optical stylus, surface profiles with less high frequency components were obtained for two kinds of machined surfaces with different surface textures. Applicability of the developed optical stylus to the profile measurement of engineering surfaces was experimentally verified.

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This paper presents a CCD camera-based system for slit width measurement of long precision slot dies. The slit width is calculated from the binary image of the slit after positions of the two edges of the slit are determined through a least square linear fitting of the edge data. The resolution of the CCD camera is on the order of sub-microns, which satisfies the requirement of quality control of the slit width. Local slit width can also be obtained because of the small field of view of the CCD camera. The slit width over the entire slot die can be measured enough scanning the CCD camera. The influence of the Z-directional straightness of the scanning stage can be reduced by choosing a proper threshold for binarization of the CCD image. Experimental results have shown that the slit width over the entire length of a 1.4 m long slot die can be measured in 33 seconds.

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In photolithography for ULSI (Ultra Large Scale Integration) manufacturing, highly accurate overlay between photomask layers has been required. Therefore, it is important to analyze the overlay errors and to reduce them. In this paper, we show an analytical method to derive their probability distribution function. The overlay errors consist of interfiled errors and intrafield errors on exposed wafers. The overlay errors were assumed as linear models. We found that the probability density function of the interfield errors has a semi-ellipse distribution and the probability density function of the intrafield errors has a trapezoid distribution, in a special case, triangle distribution. An actual overlay error from wafer measurement is a sum of the interfiled errors and intrafield errors. We call the sum of the two errors as a total overlay error. The total overlay error's distribution is derived from a convolution of these two distributions. In experiment, we analyzed interfiled errors and intrafield errors from actual exposed wafers. The convolution of two errors approximated to the total overlay error's distribution from measurement result.

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