Capacitive pressure sensor, manufacturing method thereof, and pressure measuring device

Abstract

The invention discloses a capacitive pressure sensor, which is suitable for the sensor field. It includes a substrate and a cover plate. The substrate includes a top layer, a bottom layer and an insulating layer. So that the groove forms a vacuum cavity, and the bottom of the groove forms a pressure-sensitive film, and the top layer is provided with a movable interdigital capacitor and a fixed interdigital capacitor, which are arranged staggered and equidistant from each other, and the movable interdigital capacitor passes through. The insulating layer directly under it is attached to the pressure-sensitive film, and the insulating layer directly under the fixed interdigital capacitor is suspended between the bottom layer and the fixed interdigital capacitor. The embodiment of the present invention also discloses a preparation method and a pressure measurement device of a capacitive pressure sensor. When the pressure-sensitive film is deformed by force, the facing area between the movable interdigital capacitor and the fixed interdigital capacitor can be adjusted. It has good linear output, and at the same time, the vacuum tightness is good, which can avoid the extraction of electrodes in the vacuum cavity.

Description

technical field [0001] The invention relates to the technical field of sensors, in particular to a capacitive pressure sensor, a preparation method thereof, and a pressure measuring device. Background technique [0002] With the development of the sensor industry, sensors based on Micro-Electro-Mechanical System (MEMS) technology have become one of the most important branches in the development of the sensor industry. MEMS is a semiconductor technology for mass production of microstructures, microsensors, microactuators, microsystems and their signal processing circuits. [0003] Pressure sensors based on MEMS technology are widely used in many fields such as industrial production, medical and health care, environmental monitoring, and scientific research. Among them, the capacitive pressure sensor is a main type of MEMS pressure sensor, and its fundamental principle is to convert pressure changes into capacitance changes. According to the capacitance formula, capacitive p...

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Problems solved by technology

[0004] The main purpose of the present invention is to provide a capacitive pressure sensor, its preparation method, and pressure measuring device, aiming at solving the problem of poor linearity and poor vacuum sealing of the capacitive pressure sensor in the prior art, and the electrodes in the vacuum chamber are easily drawn out. technical problem

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