Inspection techniques for frontal imaging inside thin pipes in manufacturing plants or blood vessels are important for their healthy check. The liquid filled in the pipes or the blood is always not transparent and muddy so that the direct observation using optical fibers cannot be performed. Ultrasonic imaging is useful in those cases. Previous techniques such as B-mode imaging must have a 3-dimensional(3D) reconstruction method from successive 2-dimensional images. This paper describes an ultrasonic micro ring-array probe and a 3D frontal imaging technique using this probe. The probe (2mmφ) has 8 ultrasonic transducers placed radially with respect to each other on the front surface. One of the transducer transmits a diverged beam and the other 7 ones receive the echo. A pattern matching method is used for reconstructing objects in front of the probe. The 3D viewing method of the system is based on not reconstruction technique from successive 2D images but an intrinsic 3D measurement one. This system was evaluated by applying to echo data from a computer simulation and an actual object with a projection. The results indicated that this system was useful for the inspections in manufacturing plants or in blood vessels.

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This paper deals with detailed characteristics and improvement of the sensitivity of vertical Hall cells. The vertical Hall cells are useful devices for realizing a two-or three-dimensional magnetic sensor system because they can detect the magnetic field parallel to the chip surface. First, we focused on the behavior of the offset voltage of the vertical Hall cells which is the most important specification for a practical system. The experiments showed that there is an optimum geometry with respect to the offset voltage and the spatial resolution, and the offset stability with the applied stress of vertical Hall cells is 10 to 100 times as great as that of lateral Hall cells. Moreover, we attempted a drastic improvement of the sensitivity by using trench grooves to restrict the current path. As a result, a very high product sensitivity of 1230V/AT was obtained.

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Recently, with the improvement of our life level, the quality management of foods has been required, however the taste and odor sensors for evaluating foods have yet been undeveloped. We investigated a new taste/odor sensor utilizing the optimized sensory device (OSD) which is prepared from sintering the mixture of the magnetic semiconductor powder such as Mn-Zn ferrite and ruthenium compound. When various taste and odor components included in food adheres to the OSD. resistance or electromotive force based on surface electric conduction of the OSD change. therefore it can be clearly discriminated the sort and quality of foods. Moreover, the detected data are displayed as the pattern chart through computer processing. This paper describes preparation of a thick-film OSD and construction of the multi-channel taste/odor recognition system for some drinks.

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High temperature CMOS circuits for sensor applications have been fabricated using Silicon-Direct-Bonding (SDB) SOI wafers. A novel SOI-MOSFET structure was fabricated on silicon film of 800nm in thickness above a buried oxide layer of 1μm in thickness. The MOSFET was designed in order to remove Kink-effect and parasitic bipolar transistor effect, and the fabrication process was optimized by process simulator(SUPREM III). The signal conditioning circuits (Operational amplifier and C-F converter) for sensor applications were designed and fabricated with the MOSFET. These MOSFET and signal conditioning circuits were operated up to 300°C. The temperature dependence of the MOSFET and the characteristic of the circuits were evaluated from room temperature to 300°C.

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Three dimensional accelerometer was fabricated by Poly-Si/SiO₂/Si/SiO₂/Si structure using SDB(silicon direct bonding) technology and LPCVD. The optimization of fabricated accelerometer was performed using the results of FEM(finite element method) simulation. The variations of stress according to each direction were utilized to detect the three dimensional acceleration and eliminate cross-axis sensitivities. The values of TCR(temperature coefficient of resistance) for polysilicon with two different dose amount were 611[ppm/°C] and 644 [ppm/°C] in the 25°C-250°C range respectively. TCO(temperature coefficient of offset) shift for X, Y and Z-axis Wheatstone bridge outputs was about 0-0.07[%F.S.], 0.028-0.016[%F. S. ] and 0.007--0.004[%F.S.] in the 25°C-160°C range respectively. The sensitivities of fabricated sensor for X, Y and Z-axis acceleration were about 0.0 6[mV/V⋅g], 0.06[mV/V⋅g] and 0. 13[mV/V⋅g] at a room temperature. The cross-axis sensitivity for X, Y and Z-axis acceleration was about 0.0093[mV/V⋅g], which stands for the elimination of cross-axis sensitivities as designed. The developed sensor can be used in many applications such as automotive and robot industry, navigation system and earthquake detection, etc..

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