In this article, we report a wafer-level packaged Pirani vacuum gauge using the proprietary InvenSense CMOS MEMS technology. The micro Pirani vacuum gauge features three serpentine-shaped molybdenum thermistors on the suspended silicon-on-insulator (SOI) bridges, while the wiring gap of each serpentine-shaped silicon microbridge is 1.6 ${ {\mu }}\text{m}$ . For the vacuum range of $5\times 10^{-{4}}$ –760 Torr, the CMOS MEMS Pirani gauge configured with a constant temperature interface circuit achieves a sensitivity of 0.414 V/Torr in a very fine vacuum regime, while its heating power is less than 21.3 mW. Moreover, the measured output of the micro Pirani gauge shows good agreement with a semi-empirical model, while the model predicts that the proposed Pirani gauge can measure a vacuum pressure as low as $2.6\times 10^{-{4}}$ Torr. The performance achieved by this Pirani vacuum gauge combined with its high level of integration makes it a promising Internet of Things (IoT) sensing node for vacuum monitoring in the industry.

中文翻译：

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晶圆级封装 CMOS MEMS 皮拉尼真空计


在本文中，我们介绍了一款采用 InvenSense CMOS MEMS 专有技术的晶圆级封装皮拉尼真空计。微型皮拉尼真空计在悬浮绝缘体上硅 (SOI) 桥上具有三个蛇形钼热敏电阻，而每个蛇形硅微桥的接线间隙为 1.6 ${ {\mu }}\text{m} $。对于 $5\times 10^{-{4}}$ –760 Torr 的真空范围，配备恒温接口电路的 CMOS MEMS 皮拉尼真空计在非常精细的真空状态下实现了 0.414 V/Torr 的灵敏度，而其加热功率小于21.3 mW。此外，微型皮拉尼真空计的测量输出与半经验模型吻合良好，而该模型预测所提出的皮拉尼真空计可以测量低至 $2.6\times 10^{-{4}}$ Torr 的真空压力。这款皮拉尼真空计所实现的性能与其高集成度相结合，使其成为行业中用于真空监测的有前途的物联网 (IoT) 传感节点。