Capacitive pressure sensor, preparation method thereof, and pressure measure device

Abstract

Disclosed is a capacitive pressure sensor, applicable to the field of sensors. The capacitive pressure sensor includes a substrate and a cover plate. The substrate includes a top layer, a bottom layerand an insulation layer, the lower surface of the bottom layer is provided with a groove, a lid groove, so that the groove forms a vacuum cavity, and a varistor film is formed on the groove bottom ofthe groove, wherein the top layer is provided with a movable interdigital capacitor and a fixed interdigital capacitor which are staggered and arranged at an equal distance from each other, the movable interdigital capacitor is bonded to the varistor film through an insulating layer positioned directly below the movable interdigital capacitor, and the insulating layer directly below the fixed interdigital capacitor is suspended between the bottom layer and the fixed interdigital capacitor. The embodiment of the invention also discloses a preparation method of a capacitive pressure sensor anda pressure measuring device. When the varistor film is deformed, the area of the movable interdigital capacitance relative to the fixed interdigital capacitance can be changed, thereby changing the capacitance value, and exhibiting a good linear output. At the same time, the vacuum sealing property is good, and the lead-out of the electrode in the vacuum cavity can be avoided.

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 of 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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