Pressure sensor with surrounding medium isolation cup structure and preparation method thereof

Abstract

The invention provides a pressure sensor with a surrounding medium isolation cup structure and a preparation method thereof. The preparation method includes: providing a substrate, forming a well-covered buffer layer on the substrate, and forming a piezoresistive layer in the well-covered buffer layer. The varistor layer is etched to obtain the varistor and the dielectric isolation ring set around the varistor, a dielectric isolation cup structure is formed around the varistor, and the first insulating passivation ring is formed on the well-coated buffer layer and the varistor. metallization layer, and forming a metallization via hole through the first insulating passivation layer, forming a metal lead on the first insulating passivation layer, and the metal lead is electrically connected to the piezoresistor through the metallization via hole, so as to prepare a pressure sensor. The invention can buffer the influence brought by the change of the external environment and greatly improve the reliability of the device. In addition, the present invention can effectively reduce current leakage and improve reliability. At the same time, the invention can make the structure work stably at a high temperature above 180° C., with low cost and high reliability.

Description

technical field [0001] The invention belongs to the technical field of pressure sensors, and in particular relates to a pressure sensor with a surrounding medium isolation cup structure and a preparation method thereof. Background technique [0002] A pressure sensor is a device or device that can sense pressure signals and convert the pressure signals into usable output electrical signals according to certain rules. Pressure sensor is the most commonly used sensor in industrial practice. It is widely used in various industrial automatic control environments, involving water conservancy and hydropower, railway transportation, intelligent buildings, production automatic control, aerospace, military industry, petrochemical, oil wells, electric power, ships, machine tools , pipeline and many other industries. [0003] With the further development of science and technology, ordinary pressure sensors can no longer meet the needs of production and life, especially in some special...

AI Technical Summary

Problems solved by technology

Ordinary pressure sensors are prone to damage, failure or current leakage in high-temperature environments, and their reliability is not high, and they cannot work stably in high-temperature environments.

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