Temperature and humidity sensor

Abstract

The invention provides a temperature and humidity sensor comprising a substrate. A temperature sensitive unit and a humidity sensitive unit are arranged on the substrate. The humidity sensitive unit is arranged above the temperature sensitive unit. A heat conductive medium is arranged between the temperature sensitive unit and the humidity sensitive unit. The temperature sensitive unit and the humidity sensitive unit are respectively fixed to the substrate by bonding pads. The humidity sensitive unit includes an upper electrode, a lower electrode, and a moisture sensitive medium arranged between the upper and lower electrodes; the upper electrode has a mesh microporous structure; and the lower electrode is in contact with the heat conductive medium. The heat conductive medium is a heat conductive silicone sheet or a thermally conductive ceramic insulating sheet. The temperature sensitive unit and the humidity sensitive unit are fixed to the substrate by the first bonding pad and the second bonding pad. According to the invention, the heat generated by the temperature sensitive unit is transferred to the humidity sensitive unit to solve a problem of condensation of the humidity sensitive unit; the heating structure set by the traditional sensor is saved; the size of the temperature and humidity sensor is reduced; and the production cost is lowered.

Description

technical field [0001] The invention relates to the technical field of sensors, in particular to a temperature and humidity sensor. Background technique [0002] Temperature and humidity measurement is widely used in industry, agriculture and daily life, and it is also an indispensable factor for studying meteorological conditions and environmental comfort. The temperature sensor mainly uses a thermistor, and the humidity sensor mainly uses a capacitance principle to realize detection. Early temperature and humidity measurement systems used separately designed temperature sensors and humidity sensors, which resulted in large measurement systems and poor compatibility. [0003] With the development of CMOS technology, integrated temperature and humidity sensors with integrated temperature and humidity have been introduced successively, which further reduces the size of the sensor and the size of the measurement system. However, in some special applications, such as weather ...

AI Technical Summary

Problems solved by technology

In this extreme environment, due to the structural characteristics of the capacitive humidity sensor, the surface of the humidity sensor is prone to condensation, which increases the measurement error, reduces the response speed, and even causes the humidity sensor to fail.

With the development of MEMS technology, in order to solve the problem of humidity sensor condensation, the commonly used method is to add heating wires at the bottom or around the humidity sensor to heat the humidity sensor to make the moisture evaporate, but heating the humidity sensor will cause The temperature sensor is inaccurate in measuring the ambient temperature, and the sensor volume increases, etc.

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