Constant temperature measurement-type micro humidity sensor and producing method thereof

Abstract

The invention discloses a constant temperature measurement-type micro humidity sensor and a producing method thereof, relating to the sensor technology; the sensor consists of a humidity sensitive film capacitor and a pedestal, wherein at least one electrode in the lower electrode of the humidity sensitive film capacitor acts as a capacitance or impedance measuring electrode and a constant temperature-control heating electrode and works with a temperature sensor in the lower electrode under the control of an external circuit of the sensor to cause the micro humidity sensor to measure humidityat certain constant temperature. A thin supporting film for supporting the humidity sensitive film capacitor in the sensor has through holes or clearance structures, thereby reducing heat loss and causing the sensor to realize constant temperature measurement under relatively low power consumption. The micro humidity sensor is not affected by the environmental temperature, has small temperature coefficient and good low-temperature performance, realizes the humidity measurement at negative temperatures and has a volume smaller than 2mm*2mm*2mm. The invention is applied to daily life, industrial production, weather forecast, environment monitoring, aeronautics, astronautics and other fields.

Description

technical field [0001] The invention relates to sensor technology and micro-electro-mechanical system (MEMS) technology, in particular to a structure and a manufacturing method of a constant temperature measurement type miniature humidity sensor. Background technique [0002] The miniature humidity sensor proposed by the present invention is mainly used in daily life and meteorological prediction, so the measured humidity parameter is relative humidity. Commonly used in heating, ventilation, and air conditioning applications, relative humidity is an important indicator of comfort and indoor air quality and is defined as: [0003] Relative Humidity RH% [0004] RH % = p w p s × 100 [0005] Where: pw is the partial vapor pressure, ps is the saturated vapor pressure. [0006] The measurement of relative humidity is not only ...

AI Technical Summary

Problems solved by technology

Although these miniature humidity sensors have the advantages of low cost, low power consumption, integration with traditional IC technology, high precision, good linearity, and quick response, most of them have the characteristics of being easily affected by ambient temperature, large temperature coefficient, and poor low temperature performance. Disadvantages such as inability to measure humidity at sub-zero temperatures

These shortcomings restrict the practical application of miniature humidity sensors in industrial production, weather forecasting, climate analysis, environmental monitoring, aerospace and other fields.

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