| Summary: | 碩士 === 國立雲林科技大學 === 機械工程系碩士班 === 101 === This study is to design and fabricate a micro-blood pressure sensor (MBPS) and analyze its performance. The operated pressure and frequency ranges of the designed MBPS are 0-300 mmHg and 40-100 bpm (beats per minute), respectively. In this work, first, the ANSYS software was utilized to analyze the stress and strain distributions of PECVD (plasma enhanced chemical vapor deposition) silicon dioxide (SiO2) sensing diaphragm of MBPS under the operated applied pressure range to decide the optimum thickness of sensing diaphragm and the positions of poly-silicon sensors. In this simulation result, the optimum thickness of sensing diaphragm is 1-2 μm under the operated pressure range of 0-300 mmHg and the optimum positions of set poly-silicon sensors are either at the edge or center of sensing diaphragm.
Then, the designed MBPS was fabricated by using the standard ICs and MEMS (Micro-electro-mechanical system) technologies included with LPCVD (low pressure chemical vapor deposition), PECVD, ion implantation, thermal annealing, RIE (reactive ion etching), metal PVD (physical vapor deposition), metal wet etching and DRIE (deep RIE) etc.. Finally, after the MBPS package by wire-bonding, the calibration and reliability test of MBPS were done. In this result, the sensitivities of fabricated MBPS are around 0.6 ohm/mmHg and 0.165 ohm/mmHg in the operated ranges of 0-100 mmHg and 100-300 mmHg in air, respectively. In the case of MBPS packaged with a PU film as the sensing diaphragm with a thickness of 24 μm by using the silicon oil as sensing medium, the sensitivities of fabricated MBPS are around 0.38 ohm/mmHg and 0.175 ohm/mmHg in the operated ranges of 0-100 mmHg and 100-300 mmHg, respectively.
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